U.S. patent application number 14/594206 was filed with the patent office on 2015-05-07 for polymerizable composition and dental material.
This patent application is currently assigned to KURARAY NORITAKE DENTAL INC.. The applicant listed for this patent is KURARAY NORITAKE DENTAL INC.. Invention is credited to Kenji Suzuki.
Application Number | 20150126641 14/594206 |
Document ID | / |
Family ID | 43900046 |
Filed Date | 2015-05-07 |
United States Patent
Application |
20150126641 |
Kind Code |
A1 |
Suzuki; Kenji |
May 7, 2015 |
POLYMERIZABLE COMPOSITION AND DENTAL MATERIAL
Abstract
The present invention provides a polymerizable composition that
is suitably used as a temporary cement for implant use and a mobile
tooth-fixing material. The present invention is a polymerizable
composition that includes an acrylic block copolymer (a) having at
least one polymer block A that mainly contains a (meth)acrylic acid
ester unit and that functions as a hard segment and at least one
polymer block B that mainly contains an acrylic acid ester unit and
that functions as a soft segment, a polymerizable monomer (b), and
a polymerization initiator (c).
Inventors: |
Suzuki; Kenji;
(Kurashiki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KURARAY NORITAKE DENTAL INC. |
Kurashiki-shi |
|
JP |
|
|
Assignee: |
KURARAY NORITAKE DENTAL
INC.
Kurashiki-shi
JP
|
Family ID: |
43900046 |
Appl. No.: |
14/594206 |
Filed: |
January 12, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13501118 |
Apr 10, 2012 |
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PCT/JP2010/006201 |
Oct 19, 2010 |
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14594206 |
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Current U.S.
Class: |
523/116 ;
523/115; 525/299 |
Current CPC
Class: |
A61K 6/887 20200101;
A61K 6/887 20200101; A61K 6/30 20200101; A61K 6/887 20200101; A61K
6/30 20200101; C08G 81/021 20130101; A61K 6/62 20200101; A61K 6/30
20200101; C08F 287/00 20130101; A61K 6/887 20200101; C08F 265/06
20130101; A61K 6/887 20200101; A61K 6/887 20200101; A61K 6/30
20200101; A61K 6/30 20200101; C08L 53/00 20130101; A61K 6/30
20200101; C08L 33/08 20130101; C08L 33/10 20130101; C08L 53/00
20130101; C08L 33/08 20130101; C08L 53/00 20130101; C08L 33/10
20130101; C08L 33/08 20130101; C08L 33/10 20130101; C08L 33/10
20130101; C08L 33/08 20130101; A61K 6/887 20200101; A61K 6/30
20200101; C08L 53/00 20130101 |
Class at
Publication: |
523/116 ;
525/299; 523/115 |
International
Class: |
A61K 6/083 20060101
A61K006/083; C08G 81/02 20060101 C08G081/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2009 |
JP |
2009-244795 |
Claims
1. A polymerizable composition comprising: an acrylic block
copolymer (a) having at least one polymer block A that mainly
contains a (meth)acrylic acid ester unit and that functions as a
hard segment, and at least one polymer block B that mainly contains
an acrylic acid ester unit and that functions as a soft segment; a
polymerizable monomer (b), and a polymerization initiator (c),
wherein the acrylic block copolymer (a) has a molecular weight
distribution Mw/Mn of 1.0 to 1.5, the acrylic block copolymer (a)
is inactive against a polymerizable group of the polymerizable
monomer (b), and polymerization initiator (c) comprises a chemical
polymerization initiator (c-2).
2. The polymerizable composition according to claim 1, wherein the
acrylic block copolymer (a) has a molecular weight distribution
Mw/Mn of 1.0 to 1.3.
3. (canceled)
4. The polymerizable composition according to claim 1, wherein the
polymerizable monomer (b) is a (meth)acrylate polymerizable
monomer.
5. The polymerizable composition according to claim 1, further
comprising: a polymerization accelerator (d).
6. The polymerizable composition according to claim 1, further
comprising: a filler (e).
7. The polymerizable composition according to claim 1, being used
for application to biological tissues.
8. A dental cement comprising the polymerizable composition
according to claim 1.
9. The dental cement according to claim 8, wherein the dental
cement is a temporary cement for implant use.
10. A dental mobile tooth-fixing material comprising the
polymerizable composition according to claim 1.
11. A dental composite resin comprising the polymerizable
composition according to claim 1.
12. The polymerizable composition according to claim 1, wherein
said chemical polymerization initiator (c-2) is at least one
selected from the group consisting of ketone peroxide,
hydroperoxide, diacyl peroxide, dialkyl peroxide, peroxyketal,
peroxyester, and peroxydicarbonate.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polymerizable composition
that is suitable for application to biological tissues,
particularly suitable as a temporary cement for implant use and a
mobile tooth-fixing material, and relates to a dental material
using the polymerizable composition.
BACKGROUND ART
[0002] Adhesive materials or filling materials are used for
restorative treatment of teeth, bones, etc. Polymerizable
compositions containing a polymerizable monomer, a polymerization
initiator, a filler, etc., are generally used as such adhesive
materials or filling materials. Polymerizable compositions for
restorative treatment of teeth, bones, etc., can be roughly
classified into two types depending on the hardness after curing.
One type is a soft material, a cured product of which is flexible,
to be used as an adhesive material, a shock absorber, etc., with
respect to biological tissues, such as a temporary sealing
material, a rebase for denture base, and an artificial cartilage.
With the recent development of dental care, there is a glowing
demand for new soft materials.
[0003] For example, dental treatment by implantation is widely used
in recent years for the patients who have lost their teeth due to
aging, etc. An implant is composed of an artificial tooth root to
be embedded directly in the jaw bone, a tooth crown to be placed
thereabove, and a tooth base, called an abutment, which engages the
artificial tooth root and the tooth crown. These parts are bonded
together at the time of use. For the bonding, a temporary cement is
used, but the bonded portion is required to be removable because
the implant occasionally needs to be detached for maintenance such
as washing. Therefore, a cured product of the temporary cement is
required to have excellent flexibility. The temporary cement also
is required to have appropriate viscosity and forming property
before curing so as to have excellent handling property. Further,
it is required to have good adhesive properties with respect to
metals and ceramics.
[0004] Meanwhile, the growth of periodontal disease causes gingival
recession also due to aging, etc., making it difficult to support
teeth sufficiently. As a result, the teeth become loose and lost
easily. These loose teeth are called mobile teeth. To treat such a
mobile tooth, a method of fixing the mobile tooth to a sound tooth
using a mobile tooth-fixing material is employed. The mobile
tooth-fixing material needs to be removed after recovery, and thus
is required to be removable. It also is required not to break due
to bending distortion to be applied continuously during the fixing
until recovery. For this reason, a cured product of the mobile
tooth-fixing material is required to have excellent flexibility.
The mobile tooth-fixing material also is required to have
appropriate viscosity and forming property before curing so as to
have excellent handling property. Further, it also is required to
have good adhesive properties with respect to tooth structure.
Furthermore, a cured product thereof is required to have excellent
transparency and color stability from the viewpoint of the
aesthetic value.
[0005] As a method for imparting flexibility to a polymerizable
composition, it is known to add an elastomer. For example, Patent
Literature 1 reports an example in which the impact resistance of a
metallic color-shielding adhesive material set for dental use is
improved by adding butadiene-methyl methacrylate-styrene copolymer
powder, thereby imparting flexibility thereto. Further, Patent
Literatures 2 to 4 report examples in which a dental composition to
be used for denture base, etc., is made flexible by adding a
styrene-diene block copolymer thereto, so that the stress
relaxation properties and the adhesive properties to the denture
base are improved. Further, Patent Literature 5 reports an example
in which the long-term coloration/discoloration and water
absorption properties of a dental coating material composition are
improved by adding a styrene-based thermoplastic elastomer or a
methyl methacrylate-butyl acrylate copolymer thereto.
CITATION LIST
Patent Literature
[0006] Patent Literature 1: JP 2002-226316 A
[0007] Patent Literature 2: JP 9(1997)-67223 A
[0008] Patent Literature 3: JP 10(1998)-139613 A
[0009] Patent Literature 4: JP 10(1998)-182329 A
[0010] Patent Literature 5: JP 2001-89693 A
SUMMARY OF INVENTION
Technical Problem
[0011] The metallic color-shielding adhesive material set for
dental use of Patent Literature 1 has poor dispersibility and
miscibility of the respective components because it contains an
elastomer in powder form, and thus fails to satisfy the
above-mentioned various properties such as transparency required as
a temporary cement for implant use and a mobile tooth-fixing
material.
[0012] In the dental compositions according to Patent Literatures 2
to 4, the styrene-diene block copolymer and the (meth)acrylate
monomer have different polarities from each other, which causes a
problem in their miscibility. Low miscibility causes adverse
effects on the above-mentioned various properties required as a
temporary cement for implant use and a mobile tooth-fixing
material.
[0013] In the dental coating material composition of Patent
Literature 5, in the case of using the styrene-based thermoplastic
elastomer, there is a similar problem of miscibility with the
(meth)acrylate monomer. Meanwhile, no block copolymer is
exemplified as the methyl methacrylate-butyl acrylate
copolymer.
[0014] It is therefore an object of the present invention to
provide a polymerizable composition that is suitable as a temporary
cement for implant use and a mobile tooth-fixing material. It is
another object of the present invention to provide a dental
material using the polymerizable composition.
Solution to Problem
[0015] The present invention that has achieved the above-mentioned
objects is a polymerizable composition includes: an acrylic block
copolymer (a) having at least one polymer block A that mainly
contains a (meth)acrylic acid ester unit and that functions as a
hard segment, and at least one polymer block B that mainly contains
an acrylic acid ester unit and that functions as a soft segment; a
polymerizable monomer (b); and a polymerization initiator (c).
[0016] The acrylic block copolymer (a) preferably has a molecular
weight distribution Mw/Mn of 1.0 to 1.5. The acrylic block
copolymer (a) is preferably inactive against a polymerizable group
of the polymerizable monomer (b).
[0017] The polymerizable monomer (b) is preferably a (meth)acrylate
polymerizable monomer.
[0018] The polymerizable composition of the present invention
preferably further contains a polymerization accelerator (d). The
polymerizable composition of the present invention preferably
further contains a filler (e).
[0019] The polymerizable composition of the present invention is
suitably used for application to biological tissues.
[0020] The present invention also is a dental cement using the
above-mentioned polymerizable composition. This dental cement is
optimally used as a temporary cement for implant use.
[0021] The present invention also is a mobile tooth-fixing material
using the above-mentioned polymerizable composition.
[0022] The present invention also is a dental composite resin using
the above-mentioned polymerizable composition.
Advantageous Effects of Invention
[0023] The polymerizable composition of the present invention has
both good viscosity and forming property at the same time before
curing and thus has excellent handling property. Further, it
exhibits good adhesive properties to tooth structure, bones, and
metals. Furthermore, a cured product of the polymerizable
composition has excellent flexibility, transparency, and color
stability. Accordingly, the polymerizable composition of the
present invention can be applied suitably to biological tissues
(such as teeth and bones, particularly teeth). As specific
applications, the polymerizable composition of the present
invention is optimally used as a temporary cement for implant use
and a mobile tooth-fixing material, and also is suitably used as a
dental cement and a dental composite resin.
DESCRIPTION OF EMBODIMENTS
[0024] The polymerizable composition of the present invention
includes an acrylic block copolymer (a) having at least one polymer
block A that mainly contains a (meth)acrylic acid ester unit and
that functions as a hard segment, and at least one polymer block B
that mainly contains an acrylic acid ester unit and that functions
as a soft segment; a polymerizable monomer (b); and a
polymerization initiator (c).
[0025] Acrylic Block Copolymer (a)
[0026] The acrylic block copolymer (a) to be used in the present
invention has at least one polymer block A that mainly contains a
(meth)acrylic acid ester unit and that functions as a hard segment
(hereinafter referred simply as "polymer block A"), and at least
one polymer block B that mainly contains an acrylic acid ester unit
and that functions as a soft segment (hereinafter referred simply
as "polymer block B"). Accordingly, the acrylic block copolymer (a)
functions as an elastomer.
[0027] In the present invention, the term "mainly contain" means
that the content of the corresponding monomer unit is at least 50
wt %, preferably at least 80 wt %, more preferably at least 90 wt
%, in all monomer units (repeating units) in a polymer block.
[0028] The (meth)acrylic acid ester unit that constitutes the
polymer block A is not particularly limited, as long as the polymer
block A functions as a hard segment of an elastomer. As a
(meth)acrylic acid ester, methacrylic acid ester is preferable, and
examples thereof include methyl methacrylate, ethyl methacrylate,
n-propyl methacrylate, isopropyl methacrylate, n-butyl
methacrylate, s-butyl methacrylate, t-butyl methacrylate, isobutyl
methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate,
isobornyl methacrylate, benzyl methacrylate, and phenyl
methacrylate. Among these, methyl methacrylate, isobornyl
methacrylate, and t-butyl methacrylate are preferable because the
use of them allows the polymer block A to have high glass
transition temperature and to exhibit high aggregation, so that a
cured product of the polymerizable composition of the present
invention exhibits excellent strength. The polymer block A may
contain two or more types of (meth)acrylic acid ester units.
[0029] The content of the polymer block A in the acrylic block
copolymer (a) preferably is within the range of 1 to 75 wt %, more
preferably within the range of 1.5 to 60 wt %, further preferably
within the range of 3 to 50 wt %. When the content of the polymer
block A is within the range of 1 to 75 wt %, appropriate
flexibility is imparted to a cured product of the polymerizable
composition.
[0030] The acrylic acid ester unit that constitutes polymer block B
is not particularly limited, as long as the polymer block B
functions as a soft segment of an elastomer. Accordingly, even in
the case where the polymer block A mainly contains an acrylic acid
ester unit, this acrylic acid ester unit is different from an
acrylic acid ester unit that is contained in the polymer block B as
the main component. Examples of the acrylic acid ester include
methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl
acrylate, n-butyl acrylate, isobutyl acrylate, s-butyl acrylate,
t-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate,
2-ethylhexyl acrylate, dodecyl acrylate, lauryl acrylate, stearyl
acrylate, 2-methoxyethyl acrylate, and 2-(N,N-dimethylaminoethyl)
acrylate. Among these, n-butyl acrylate, 2-ethylhexyl acrylate are
preferable because the use of them allows the polymer block B to
have low glass transition temperature, so that a cured product of
the polymerizable composition of the present invention exhibits
excellent flexibility. The polymer block B may contain two or more
types of acrylic acid ester units.
[0031] The content of the polymer block B in the acrylic block
copolymer (a) is preferably within the range of 25 to 99 wt %, more
preferably within the range of 40 to 98.5 wt %, further preferably
within the range of 50 to 97 wt %. When the content of the polymer
block A is within the range of 25 to 99 wt %, appropriate
flexibility is imparted to a cured product of the polymerizable
composition.
[0032] Concerning the polymer block A and the polymer block B, the
acrylic acid ester unit that constitutes the polymer block B may be
contained in the polymer block A, and the (meth)acrylic acid ester
unit that constitutes the polymer block A may likewise be contained
in the polymer block B, as long as the effects of the present
invention are not impaired. Further, other monomer units may be
contained in these polymer blocks, as long as the effects of the
present invention are not impaired. Examples of such other monomer
include a (meth)acrylic acid ester having a functional group such
as 2-hydroxyethyl (meth)acrylate, 2-aminoethyl (meth)acrylate,
glycidyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate; a
vinyl monomer having a carboxyl group such as (meth)acrylic acid,
maleic acid, and maleic acid anhydride; (meth)acrylamide; an
aromatic vinyl monomer such as styrene, alpha-methylstyrene, and
p-methylstyrene; a conjugate diene monomer such as butadiene and
isoprene; an olefin monomer such as ethylene and propylene; and a
lactone monomer such as epsilon-caprolactone and valerolactone.
[0033] The form of the bonding between the polymer block A and the
polymer block B in the acrylic block copolymer (a) is not limited,
as long as the polymer block A and the polymer block B are bonded
to each other, and may be any one of the bonding forms selected
from a straight chain, a branched chain, and a radial pattern, or a
combination of two or more of them. Among these, the polymer block
A and the polymer block B are preferably bonded in the form of a
straight chain, and examples thereof include, when the polymer
block A is referred to as "A" and the polymer block B is referred
to as "B", a diblock copolymer represented by A-B, a triblock
copolymer represented by A-B-A, a tetrablock copolymer represented
by A-B-A-B, and a pentablock copolymer represented by A-B-A-B-A.
Above all, a diblock copolymer (A-B) and a triblock copolymer
(A-B-A) are preferably used, and a triblock copolymer (A-B-A) is
further preferably used, because of ease of producing the acrylic
block copolymer (a) and excellent flexibility of a cured product of
the polymerizable composition.
[0034] The weight-average molecular weight (Mw) of the acrylic
block copolymer (a) to be used in the present invention is
preferably within the range of 5000 to 500000, more preferably
within the range of 10000 to 200000, further preferably within the
range of 30000 to 150000, in view of the solubility of the acrylic
block copolymer (a) in the polymerizable monomer (b) and the
flexibility of a cured product of the polymerizable composition. It
should be noted that the weight-average molecular weight (Mw)
herein means a weight-average molecular weight in terms of
polystyrene as determined by gel permeation chromatography
(GPC).
[0035] The molecular weight distribution (weight-average molecular
weight/number-average molecular weight: Mw/Mn) of the acrylic block
copolymer (a) to be used in the present invention is preferably 1.0
to 1.5, more preferably 1.0 to 1.4, further preferably 1.0 to 1.3,
because appropriate viscosity and forming property of the
composition, and high flexibility of a cured product thereof are
easily obtained.
[0036] The production method of the acrylic block copolymer (a) to
be used in the present invention is not specifically limited, as
long as a copolymer that satisfies the conditions of the present
invention on the chemical structure can be obtained, and a method
according to known techniques can be employed. In order to obtain a
block copolymer with a narrow molecular weight distribution, a
method of subjecting monomers as a structural unit to living
polymerization is employed. Living polymerization allows a block
copolymer even with a molecular weight distribution of 1.0 to 1.3
to be obtained. Example of the techniques for living polymerization
include a method of performing polymerization using an organic rare
earth complex as a polymerization initiator, a method of performing
anionic polymerization in the presence of a mineral acid salt such
as salts of alkali metals or alkaline earth metals using an organic
alkali metal compound as a polymerization initiator, a method of
performing anionic polymerization in the presence of an
organoaluminium compound using an organic alkali metal compound as
a polymerization initiator, and a method known as Atom Transfer
Radical Polymerization (ATRP).
[0037] Among the above-mentioned production methods, the method of
performing anionic polymerization in the presence of an
organoaluminium compound using an organic alkali metal compound as
a polymerization initiator allows a block copolymer with a narrower
molecular weight distribution to be produced, high polymerization
rate to be obtained, and living polymerization to be performed
under comparatively moderate temperature conditions. Thus, the
acrylic block copolymer (a) to be used in the present invention is
preferably produced by anionic polymerization in the presence of an
organoaluminium compound using an organic alkali metal compound as
a polymerization initiator.
[0038] For example, as described in WO 2007/029783, a method of
sequentially polymerizing the (meth)acrylic acid ester and the
acrylic acid ester that form the respective polymer blocks in the
acrylic block copolymer (a), in the presence of an organolithium
compound and an organoaluminium compound represented by the
following general formula:
AlR.sup.1R.sup.2R.sup.3
(where R.sup.1 denotes an alkyl group that may have a substituent,
an alkoxy group that may have a substituent, or an aryloxy group
that may have a substituent, and R.sup.2 and R.sup.3 each
independently denote an alkyl group that may have a substituent, an
alkoxy group that may have a substituent, or an aryloxy group that
may have a substituent, or R.sup.2 and R.sup.3 may be coupled
together to form an arylenedioxy group that may have a
substituent), additionally using N,N,N',N'',N''-pentamethyl
diethylene triamine or other tertiary amines; and an ether such as
1,2-dimethoxyethane and a crown ether represented by 12-crown-4, on
an as-needed basis, can be employed to perform the above-mentioned
anionic polymerization in the presence of an organoaluminium
compound using an organic alkali metal compound as a polymerization
initiator.
[0039] Examples of the aforementioned organolithium compound that
can be used for producing the acrylic block copolymer (a) include
alkyl lithiums such as methyl lithium, n-butyl lithium, sec-butyl
lithium, and t-butyl lithium; aralkyl lithiums such as
1,1-diphenylhexyl lithium and diphenylmethyl lithium; phenyl
lithium, and trimethylsiloxylithium.
[0040] Further, examples of the organoaluminium compound
represented by the general formula include trimethyl aluminum,
triethyl aluminum, triisobutyl aluminum,
dimethyl(2,6-di-t-butyl-4-methylphenoxy)aluminum,
diethyl(2,6-di-t-butyl-4-methylphenoxy)aluminum,
diisobutyl(2,6-di-t-butyl-4-methylphenoxy)aluminum,
methylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum,
ethylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum, and
isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum. Among these,
isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum is preferably
used from the viewpoint of the capability of suppressing side
reactions during polymerization and the ease of handling.
[0041] The acrylic block copolymer (a) to be used in the present
invention is suitably produced by living polymerization. However,
when it is used for the polymerizable composition, the chain end of
the acrylic block copolymer (a) is preferably terminated in order
to prevent side reactions. Accordingly, the acrylic block copolymer
(a) is preferably inactive against the polymerizable group of the
polymerizable monomer (b). Being inactive against the polymerizable
group means not to cause any chemical reaction such as
polymerization initiation reaction and coupling reaction with the
polymerizable group.
[0042] Polymerizable Monomer (b)
[0043] As the polymerizable monomer (b) to be used for the
polymerizable composition of the present invention, a radical
polymerizable monomer is suitably used. Specific examples of the
radical polymerizable monomer in the polymerizable monomer (b)
include esters, for example, of alpha-cyanoacrylic acid,
(meth)acrylic acid, alpha-halogenated acrylic acid, crotonic acid,
cinnamic acid, sorbic acid, maleic acid, and itaconic acid,
(meth)acrylamide, (meth)acrylamide derivatives, vinyl esters, vinyl
ethers, mono-N-vinyl derivatives, and styrene derivatives. As the
polymerizable monomer (b), a (meth)acrylate polymerizable monomer
is preferable from the viewpoint of the miscibility with the
acrylic block copolymer (a).
[0044] As an example of the polymerizable monomer (b) in the
present invention, a monofunctional monomer having one
polymerizable group and a polyfunctional monomer having a plurality
of polymerizable groups are mentioned.
[0045] Examples of the monofunctional monomer include
2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,
3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate,
6-hydroxyhexyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate,
propylene glycol mono(meth)acrylate, glycerol mono(meth)acrylate,
erythritol mono(meth)acrylate, N-methylol (meth)acrylamide,
N-hydroxyethyl (meth)acrylamide, N,N-(dihydroxyethyl)
(meth)acrylamide, methyl (meth)acrylate, ethyl (meth)acrylate,
propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl
(meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate,
isobutyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl
(meth)acrylate, lauryl (meth) acrylate, cetyl (meth)acrylate,
stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl
(meth)acrylate, phenyl (meth)acrylate, 2,3-dibromopropyl
(meth)acrylate, 3-(meth)acryloyloxypropyltrimethoxysilane,
11-(meth)acryloyloxyundecyltrimethoxysilane, and (meth)acrylamide.
One of them may be used alone, or two or more types of them may be
used in combination. Among these, methyl methacrylate, ethyl
(meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate,
t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-hexyl
(meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl
(meth)acrylate are preferable because the miscibility with the
acrylic block copolymer (a) and the flexibility of a cured product
of the polymerizable composition are excellent. Methyl
methacrylate, t-butyl (meth)acrylate, and isobornyl methacrylate
are further preferable because the toughness of a cured product of
the polymerizable composition is excellent in addition.
[0046] Further, the polymerizable composition of the present
invention may contain an acidic group-containing polymerizable
monomer as the polymerizable monomer (b) since good bond strength
to teeth, bones, and metals can be obtained. Examples of such an
acidic group-containing polymerizable monomer include a radical
polymerizable monomer that has at least one acidic group such as
phosphoric acid group, pyrophosphoric acid group, thiophosphoric
acid group, phosphonic acid group, sulfonic acid group, and
carboxylic acid group, together with a polymerizable group.
[0047] Examples of the polymerizable monomer having a phosphoric
acid group include 2-(meth)acryloyloxyethyl dihydrogen phosphate,
3-(meth)acryloyloxypropyl dihydrogen phosphate,
4-(meth)acryloyloxybutyl dihydrogen phosphate,
5-(meth)acryloyloxypentyl dihydrogen phosphate,
6-(meth)acryloyloxyhexyl dihydrogen phosphate,
7-(meth)acryloyloxyheptyl dihydrogen phosphate,
8-(meth)acryloyloxyoctyl dihydrogen phosphate,
9-(meth)acryloyloxynonyl dihydrogen phosphate,
10-(meth)acryloyloxydecyl dihydrogen phosphate,
11-(meth)acryloyloxyundecyl dihydrogen phosphate,
12-(meth)acryloyloxydodecyl dihydrogen phosphate,
16-(meth)acryloyloxyhexadecyl dihydrogen phosphate,
20-(meth)acryloyloxyicosyl dihydrogen phosphate,
bis[2-(meth)acryloyloxyethyl]hydrogen phosphate,
bis[4-(meth)acryloyloxybutyl]hydrogen phosphate,
bis[6-(meth)acryloyloxyhexyl]hydrogen phosphate,
bis[8-(meth)acryloyloxyoctyl]hydrogen phosphate,
bis[9-(meth)acryloyloxynonyl]hydrogen phosphate,
bis[10-(meth)acryloyloxydecyl]hydrogen phosphate,
1,3-di(meth)acryloyloxypropyl dihydrogen phosphate,
2-(meth)acryloyloxyethylphenyl hydrogen phosphate,
2-(meth)acryloyloxyethyl-2-bromoethyl hydrogen phosphate,
bis[2-(meth)acryloyloxy-(1-hydroxymethyl)ethyl]hydrogen phosphate,
and their acid chlorides, alkali metal salts, and ammonium salts.
These may be used individually, or two or more types of them may be
used in combination.
[0048] Among the above-mentioned examples of the acidic
group-containing polymerizable monomer, the acidic group-containing
polymerizable monomer preferably has a phosphoric acid group or a
phosphonic acid group, and more preferably has a phosphoric acid
group, because of excellent miscibility with the acrylic block
copolymer (a) and good bond strength of the polymerizable
composition to teeth, bones, and metals. Above all, the acidic
group-containing polymerizable monomer preferably contains in its
molecule an alkyl group or an alkylene group having 6 to 20 carbon
atoms in the main chain, and it more preferably contains in its
molecule an alkylene group having 8 to 12 carbon atoms in the main
chain, as 10-(meth)acryloyloxydecyl dihydrogen phosphate does, for
example.
[0049] Examples of the polyfunctional monomer include aromatic
compound-based bifunctional polymerizable monomers, aliphatic
compound-based bifunctional polymerizable monomers, and at least
trifunctional polymerizable monomers.
[0050] Examples of the aromatic compound-based bifunctional
polymerizable monomers include
2,2-bis((meth)acryloyloxyphenyl)propane,
2,2-bis[4-(3-(meth)acryloyloxy)-2-hydroxypropoxyphenyl]propane
(commonly known as "Bis-GMA"),
2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane,
2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane,
2,2-bis(4-(meth)acryloyloxydiethoxyphenyl)propane,
2,2-bis(4-(meth)acryloyloxytetraethoxyphenyl)propane,
2,2-bis(4-(meth)acryloyloxypentaethoxyphenyl)propane,
2,2-bis(4-(meth)acryloyloxydipropoxyphenyl)propane,
2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyethoxyphenyl)-
-propane,
2-(4-(meth)acryloyloxydiethoxyphenyl)-2-(4-(meth)acryloyloxyditr-
iethoxyphenyl) propane,
2-(4-(meth)acryloyloxydipropoxyphenyl)-2-(4-(meth)acryloyloxytriethoxyphe-
nyl) propane, 2,2-bis(4-(meth)acryloyloxypropoxyphenyl)propane,
2,2-bis(4-(meth)acryloyloxyisopropoxyphenyl)propane, and
1,4-bis(2-(meth)acryloyloxyethyl)pyromeritate. These may be used
individually, or two or more types of them may be used in
combination. Among these,
2,2-bis(4-(meth)acryloyloxypolyethoxyphenyl)propane is preferable
because the miscibility with the acrylic block copolymer (a) and
the strength of a cured product of the polymerizable composition
are excellent. Particularly, a compound in which the average number
of moles of added ethoxy group is 2.6 (commonly known as "D2.6E")
is preferable.
[0051] Examples of the aliphatic compound-based bifunctional
polymerizable monomers include glycerol di(meth)acrylate, ethylene
glycol di(meth)acrylate, diethylene glycol di(meth)acrylate,
triethylene glycol di(meth)acrylate, propylene glycol
di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl
glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate,
1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate,
1,6-hexanediol di(meth)acrylate, 2-ethyl-1,6-hexanediol
di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol
di(meth)acrylate,
1,2-bis(3-methacryloyloxy-2-hydroxypropoxy)ethane, and
2,2,4-trimethylhexamethylene bis(2-carbamoyloxyethyl)
dimethacrylate (commonly known as "UDMA"). Among these, glycerol
di(meth)acrylate, triethylene glycol di(meth)acrylate, neopentyl
glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate,
1,6-hexanediol di(meth)acrylate, 2-ethyl-1,6-hexanediol
di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decaneol
di(meth)acrylate, and 2,2,4-trimethylhexamethylene
bis(2-carbamoyloxyethyl) dimethacrylate are preferable because the
miscibility with the acrylic block copolymer (a) and the
handleability of the polymerizable composition to be obtained are
excellent. These may be used individually, or two or more types of
them may be used in combination.
[0052] Examples of the at least trifunctional polymerizable
monomers include trimethylolpropane tri(meth)acrylate,
trimethylolethane tri(meth)acrylate, trimethylolmethane
tri(meth)acrylate, pentaerythritol tri(meth)acrylate,
pentaerythritol tetra(meth)acrylate, dipentaerythritol
penta(meth)acrylate,
N,N-(2,2,4-trimethylhexamethylene)bis[2-(aminocarboxy)propane-1,3-diol]te-
tramethacrylate, and
1,7-diacryloyloxy-2,2,6,6-tetraacryloyloxymethyl-4-oxyheptane.
Among these, trimethylolpropane tri(meth)acrylate is preferable
because the miscibility with the acrylic block copolymer (a) is
excellent.
[0053] One of the above-mentioned examples of the polymerizable
monomer (b) may be used alone. However, it is preferable that a
bifunctional polymerizable monomer and a monofunctional monomer be
used in combination from the viewpoint of the curability of the
polymerizable composition and the toughness and flexibility of a
cured product thereof. The ratio in the combined use of them is not
specifically limited, but the content of the bifunctional
polymerizable monomer is preferably 1 to 75 wt %, more preferably
2.5 to 50 wt %, further preferably 5 to 25 wt %, when the total
amount of the polymerizable monomer (b) is taken as 100 wt %. When
the content of the bifunctional polymerizable monomer is 75 wt % or
less, the toughness of a cured product of the polymerizable
composition is rendered high, where the cured product is less
likely to break. In this description, the phrase "total amount of
the polymerizable monomer (b)" means the total amount of
polymerizable monomers contained in the whole composition. For
example, when an embodiment of a two-part type composition is
employed in the present invention, it means the total weight of
polymerizable monomers contained in the respective parts.
[0054] Further, the content of the acidic group-containing
polymerizable monomer is not specifically limited, but is
preferably 1 to 50 wt %, more preferably 1.5 to 25 wt %, further
preferably 2.5 to 15 wt %, when the total amount of the
polymerizable monomer (b) is taken as 100 wt %. When the content of
the acidic group-containing polymerizable monomer is 1 wt % or
more, good bond strength is obtained. Meanwhile, when the content
of the acidic group-containing polymerizable monomer is 50 wt % or
less, the miscibility of the polymerizable composition is
maintained at an appropriate level.
[0055] Regarding the amount of the acrylic block copolymer (a) and
the polymerizable monomer (b) to be used, 5 to 500 parts by weight
of the acrylic block copolymer (a) is preferably used, and 10 to
250 parts by weight of the acrylic block copolymer (a) is more
preferably used, with respect to 100 parts by weight of the total
amount of the polymerizable monomer (b).
[0056] Polymerization Initiator (c)
[0057] The polymerization initiator (c) to be used in the present
invention can be selected from polymerization initiators commonly
used in the industrial field. Among them, polymerization initiators
used for dental applications are preferably used. Particularly, a
photopolymerization initiator (c-1) and a chemical polymerization
initiator (c-2) are used independently or two or more of them are
used appropriately in combination.
[0058] Examples of the photopolymerization initiator (c-1) include
(bis)acylphosphine oxides, thioxanthones or the quaternary ammonium
salts of thioxanthones, ketals, alpha-diketones, coumarins,
anthraquinones, benzoin alkyl ether compounds, and alpha-amino
ketone compounds.
[0059] Preferably, among these photopolymerization initiators, at
least one selected from the group consisting of (bis)acylphosphine
oxides and salts thereof, and alpha-diketones is used. This makes
it possible to obtain a composition that has excellent
photocurability in visible and near-ultraviolet ranges and
sufficiently high photocurability regardless of which light source
among a halogen lamp, light-emitting diode (LED), and xenon lamp is
used.
[0060] In the (bis)acylphosphine oxides to be used as the
photopolymerization initiator, examples of acylphosphine oxides
include 2,4,6-trimethylbenzoyldiphenylphosphine oxide,
2,6-dimethoxybenzoyldiphenylphosphine oxide,
2,6-dichlorobenzoyldiphenylphosphine oxide,
2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide,
2,4,6-trimethylbenzoylethoxyphenylphosphine oxide,
2,3,5,6-tetramethylbenzoyldiphenylphosphine oxide, and benzoyl
di-(2,6-dimethylphenyl) phosphonate. Examples of the
bisacylphosphine oxides include
bis-(2,6-dichlorobenzoyl)phenylphosphine oxide,
bis-(2,6-dichlorobenzoyl)-2,5-dimethylphenylphosphine oxide,
bis-(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide,
bis-(2,6-dichlorobenzoyl)-1-naphthylphenylphosphine oxide,
bis-(2,6-dimethoxybenzoyl)phenylphosphine oxide,
bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide,
bis-(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide,
bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide,
(2,5,6-trimethylbenzoyl)-2,4,4-trimethylpentylphosphine oxide,
2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt,
2,4,6-trimethylbenzoylphenylphosphine oxide potassium salt, and
2,4,6-trimethylbenzoylphenylphosphine oxide ammonium salt. In
addition, the compounds disclosed in JP 2000-159621 A also can be
mentioned.
[0061] Among these (bis)acylphosphine oxides,
2,4,6-trimethylbenzoyldiphenylphosphine oxide,
2,4,6-trimethylbenzoylmethoxyphenylphosphine oxide,
bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and
2,4,6-trimethylbenzoylphenylphosphine oxide sodium salt are
particularly preferable.
[0062] Examples of the alpha-diketones to be used as the
above-mentioned photopolymerization initiator include diacetyl,
dibenzyl, camphorquinone, 2,3-pentadione, 2,3-octadione,
9,10-phenanthrenquinone, 4,4'-oxybenzyl, and acenaphthenequinone.
Among these, camphorquinone is particularly preferable since it has
the maximum absorption wavelength in the visible light region.
[0063] As the chemical polymerization initiator (c-2) in the
polymerization initiator (c) to be used in the present invention,
an organic peroxide is preferably used. The organic peroxide to be
used as the chemical polymerization initiator is not particularly
limited and a known one can be used. Typical examples of the
organic peroxide include ketone peroxide, hydroperoxide, diacyl
peroxide, dialkyl peroxide, peroxyketal, peroxyester, and
peroxydicarbonate.
[0064] Examples of the ketone peroxide to be used as the chemical
polymerization initiator include methyl ethyl ketone peroxide,
methyl isobutyl ketone peroxide, methylcyclohexanone peroxide, and
cyclohexanone peroxide.
[0065] Examples of the hydroperoxide to be used as the chemical
polymerization initiator include
2,5-dimethylhexane-2,5-dihydroperoxide, diisopropylbenzene
hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide, and
1,1,3,3-tetramethylbutyl hydroperoxide.
[0066] Examples of the diacyl peroxide to be used as the chemical
polymerization initiator include acetyl peroxide, isobutyryl
peroxide, benzoyl peroxide, decanoyl peroxide,
3,5,5-trimethylhexanoyl peroxide, 2,4-dichlorobenzoyl peroxide, and
lauroyl peroxide.
[0067] Examples of the dialkyl peroxide to be used as the chemical
polymerization initiator include di-t-butyl peroxide, dicumyl
peroxide, t-butylcumyl peroxide,
2,5-dimethyl-2,5-di(t-butylperoxy)hexane,
1,3-bis(t-butylperoxyisopropyl)benzene, and
2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne.
[0068] Examples of the peroxyketal to be used as the chemical
polymerization initiator include
1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,
1,1-bis(t-butylperoxy)cyclohexane, 2,2-bis(t-butylperoxy)butane,
2,2-bis(t-butylperoxy)octane, and 4,4-bis(t-butylperoxy)valeric
acid-n-butyl ester.
[0069] Examples of the peroxyester to be used as the chemical
polymerization initiator include alpha-cumyl peroxyneodecanoate,
t-butyl peroxyneodecanoate, t-butyl peroxypivalate,
2,2,4-trimethylpentylperoxy-2-ethyl hexanoate, t-amyl
peroxy-2-ethylhexanoate, t-butyl peroxy-2-ethylhexanoate,
di-t-butyl peroxyisophthalate, di-t-butyl
peroxyhexahydroterephthalate, t-butyl
peroxy-3,3,5-trimethylhexanoate, t-butyl peroxyacetate, t-butyl
peroxybenzoate, and t-butyl peroxymaleic acid.
[0070] Examples of the peroxydicarbonate to be used as the chemical
polymerization initiator include di-3-methoxy peroxydicarbonate,
di-2-ethylhexyl peroxydicarbonate,
bis(4-t-butylcyclohexyl)peroxydicarbonate, diisopropyl
peroxydicarbonate, di-n-propyl peroxydicarbonate, di-2-ethoxyethyl
peroxydicarbonate, and diallyl peroxydicarbonate.
[0071] Among these organic peroxides, diacyl peroxide is preferably
used from the viewpoint of the comprehensive balance of safety,
storage stability, and radical generation ability, and among the
examples thereof, benzoyl peroxide is particularly preferably
used.
[0072] The content of the polymerization initiator (c) to be used
in the present invention is not particularly limited, but is
preferably 0.001 to 30 parts by weight with respect to 100 parts by
weight of the total amount of the polymerizable monomer (b) from
the viewpoint of the curability, etc., of the composition to be
obtained. When the content of the polymerization initiator (c) is
less than 0.001 part by weight, there are cases where
polymerization does not proceed sufficiently and stickiness occurs.
Therefore, the content thereof is more preferably at least 0.05
part by weight, further preferably at least 0.1 part by weight. On
the other hand, when the content of the polymerization initiator
(c) exceeds 30 parts by weight in the case where the polymerization
initiator itself has low polymerization performance, precipitation
from the composition may occur. Therefore, the content thereof is
more preferably 20 parts by weight or less, further preferably 15
parts by weight or less, most preferably 10 parts by weight or
less.
[0073] The polymerizable composition of the present invention is
not specifically limited, as long as it contains the
above-mentioned acrylic block copolymer (a), the polymerizable
monomer (b), and the polymerization initiator (c). The
polymerizable composition of the present invention can be easily
produced by a method known to those skilled in the art.
[0074] Polymerization Accelerator (d)
[0075] The polymerizable composition of the present invention
preferably contains a polymerization accelerator (d). Examples of
the polymerization accelerator (d) include amines, sulfinic acid
and salts thereof, sulfite, bisulfite, aldehydes, thiourea
compounds, organophosphorus compounds, borate compounds, barbituric
acid derivatives, triazine compounds, copper compounds, tin
compounds, vanadium compounds, halogen compounds, and thiol
compounds.
[0076] Amines to be used as the polymerization accelerator (d) can
be classified into aliphatic amines and aromatic amines. Examples
of the aliphatic amines include: primary aliphatic amines such as
n-butylamine, n-hexylamine, and n-octylamine; secondary aliphatic
amines such as diisopropylamine, dibutylamine, and
N-methylethanolamine; and tertiary aliphatic amines such as
N-methyldiethanolamine, N-ethyldiethanolamine,
N-n-butyldiethanolamine, N-lauryldiethanolamine,
2-(dimethylamino)ethyl methacrylate, N-methyldiethanolamine
dimethacrylate, N-ethyldiethanolamine dimethacrylate,
triethanolamine monomethacrylate, triethanolamine dimethacrylate,
triethanolamine trimethacrylate, triethanolamine, trimethylamine,
triethylamine, and tributylamine. Among these, tertiary aliphatic
amines are preferable from the viewpoint of the curability and
storage stability of the composition. Particularly,
N-methyldiethanolamine and triethanolamine are more preferably
used.
[0077] Examples of the aromatic amines include
N,N-bis(2-hydroxyethyl)-3,5-dimethylaniline,
N,N-di(2-hydroxyethyl)-p-toluidine,
N,N-bis(2-hydroxyethyl)-3,4-dimethylaniline,
N,N-bis(2-hydroxyethyl)-4-ethylaniline,
N,N-bis(2-hydroxyethyl)-4-isopropylaniline,
N,N-bis(2-hydroxyethyl)-4-t-butylaniline,
N,N-bis(2-hydroxyethyl)-3,5-di-isopropylaniline,
N,N-bis(2-hydroxyethyl)-3,5-di-t-butylaniline, N,N-dimethylaniline,
N,N-dimethyl-p-toluidine, N,N-dimethyl-m-toluidine,
N,N-diethyl-p-toluidine, N,N-dimethyl-3,5-dimethylaniline,
N,N-dimethyl-3,4-dimethylaniline, N,N-dimethyl-4-ethylaniline,
N,N-dimethyl-4-isopropylaniline, N,N-dimethyl-4-t-butylaniline,
N,N-dimethyl-3,5-di-t-butylaniline, 4-N,N-dimethylaminobenzoic acid
ethyl ester, 4-N,N-dimethylaminobenzoic acid methyl ester,
N,N-dimethylaminobenzoic acid n-butoxyethyl ester,
4-N,N-dimethylaminobenzoic acid 2-(methacryloyloxy)ethyl ester,
4-N,N-dimethylaminobenzophenone, and butyl 4-dimethylaminobenzoate.
Among these, at least one selected from the group consisting of
N,N-di(2-hydroxyethyl)-p-toluidine, 4-N,N-dimethylaminobenzoic acid
ethyl ester, N,N-dimethylaminobenzoic acid n-butoxyethyl ester, and
4-N,N-dimethylaminobenzophenone is used preferably because
excellent curability can be imparted to the composition.
[0078] Examples of the sulfinic acid and salt thereof to be used as
the polymerization accelerator (d) include p-toluenesulfinic acid,
sodium p-toluenesulfinate, potassium p-toluenesulfinate, lithium
p-toluenesulfinate, calcium p-toluenesulfinate, benzenesulfinic
acid, sodium benzenesulfinate, potassium benzenesulfinate, lithium
benzenesulfinate, calcium benzenesulfinate,
2,4,6-trimethylbenzenesulfinic acid, sodium
2,4,6-trimethylbenzenesulfinate, potassium
2,4,6-trimethylbenzenesulfinate, lithium
2,4,6-trimethylbenzenesulfinate, calcium
2,4,6-trimethylbenzenesulfinate, 2,4,6-triethylbenzenesulfinic
acid, sodium 2,4,6-triethylbenzenesulfinate, potassium
2,4,6-triethylbenzenesulfinate, lithium
2,4,6-triethylbenzenesulfinate, calcium
2,4,6-triethylbenzenesulfinate, 2,4,6-triisopropylbenzenesulfinic
acid, sodium 2,4,6-triisopropylbenzenesulfinate, potassium
2,4,6-triisopropylbenzenesulfinate, lithium
2,4,6-triisopropylbenzenesulfinate, and calcium
2,4,6-triisopropylbenzenesulfinate. Sodium benzenesulfinate, sodium
p-toluenesulfinate, and sodium 2,4,6-triisopropylbenzenesulfinate
are particularly preferable.
[0079] As the sulfite and bisulfite to be used as the
polymerization accelerator (d), sodium sulfite, potassium sulfite,
calcium sulfite, ammonium sulfite, sodium bisulfite, and potassium
bisulfite, for example, can be mentioned. Among these, sodium
sulfite is preferably used from the viewpoint of curability.
[0080] Examples of the aldehydes to be used as the polymerization
accelerator (d) include terephthalaldehyde and benzaldehyde
derivatives. Examples of the benzaldehyde derivatives include
dimethylaminobenzaldehyde, p-methyloxybenzaldehyde,
p-ethyloxybenzaldehyde, and p-n-octyloxybenzaldehyde. Among these,
p-n-octyloxybenzaldehyde is preferably used from the viewpoint of
curability.
[0081] Examples of the thiourea compounds to be used as the
polymerization accelerator (d) include 1-(2-pyridyl)-2-thiourea,
thiourea, methylthiourea, ethylthiourea, N,N'-dimethylthiourea,
N,N'-diethylthiourea, N,N'-di-n-propylthiourea,
N,N'-dicyclohexylthiourea, trimethylthiourea, triethylthiourea,
tri-n-propylthiourea, tricyclohexylthiourea, tetramethylthiourea,
tetraethylthiourea, tetra-n-propylthiourea, and
tetracyclohexylthiourea.
[0082] Examples of the organophosphorus compounds to be used as the
polymerization accelerator (d) include triphenylphosphine,
2-methyltriphenylphosphine, 4-methyltriphenylphosphine,
2-methoxytriphenylphosphine, 4-methoxytriphenylphosphine,
tri-n-butylphosphine, triisobutylphosphine, and
tri-t-butylphosphine. Among these, triphenylphosphine and
2-methyltriphenylphosphine are preferably used from the viewpoint
of curability.
[0083] The content of the polymerization accelerator (d) to be used
for the present invention is not specifically limited, but 0.001 to
30 parts by weight of the polymerization accelerator (d) is
preferably contained with respect to 100 parts by weight of the
total amount of the polymerizable monomer (b) from the viewpoint of
the curability of the composition to be obtained. When the content
of the polymerization accelerator (d) is less than 0.001 part by
weight, there are cases where polymerization does not proceed
sufficiently and stickiness occurs. Therefore, the content is more
suitably at least 0.05 part by weight, further suitably at least
0.1 part by weight. On the other hand, when the content of the
polymerization initiator (d) exceeds 30 parts by weight in the case
where the polymerization initiator itself has low polymerization
performance, precipitation from the composition may occur.
Therefore, the content thereof is more preferably 20 parts by
weight or less, further preferably 10 parts by weight or less.
[0084] In the present invention, the chemical polymerization
initiator (c-2) and the polymerization accelerator (d) may be
combined to form a redox polymerization initiator. In this case,
the chemical polymerization initiator (c-2) and the polymerization
accelerator (d) are stored in separate containers from the
viewpoint of storage stability. Accordingly, the dental
polymerizable composition is provided as a product that at least
includes a first part containing the chemical polymerization
initiator (c-2) and a second part containing the polymerization
accelerator (d). Preferably, the dental polymerizable composition
is provided as a kit to be used in the form of a two-part
composition composed of the first part and the second part. Further
preferably, it is provided as a kit to be used as a two-paste type
in which both parts are in paste form. When the composition is used
as a two-paste type, it is preferable that the respective pastes be
separated from each other during storage, and then immediately
before the use, the two pastes be mixed and kneaded to allow
chemical polymerization to proceed, or to allow chemical
polymerization and photopolymerization to proceed in the case where
a photopolymerization initiator is further contained therein, so as
to be cured.
[0085] Filler (e)
[0086] In the polymerizable composition of the present invention, a
filler (e) may be further contained in order to adjust the paste
properties of the polymerizable composition before curing, and also
to enhance the mechanical strength of a cured product thereof. As
such a filler, an organic filler, an inorganic filler, and an
organic-inorganic composite filler can be mentioned, for
example.
[0087] As a material of the organic filler, polymethylmethacrylate,
polyethylmethacrylate, methyl methacrylate-ethyl methacrylate
copolymer, crosslinked polymethylmethacrylate, crosslinked
polyethylmethacrylate, polyester, polyamide, polycarbonate,
polyphenylene ether, polyoxymethylene, polyvinyl chloride,
polystyrene, polyethylene, polypropylene, chloroprene rubber,
nitrile rubber, ethylene-vinyl acetate copolymer, styrene-butadiene
copolymer, acrylonitrile-styrene copolymer, and
acrylonitrile-styrene-butadiene copolymer can be mentioned, for
example. These may be used independently or may be used as a
mixture of two or more of them. The shape of the organic filler is
not particularly limited, and the particle size of the filler to be
used can be selected appropriately.
[0088] As a material of the inorganic filler, quartz, silica,
alumina, silica-titania, silica-titania-barium oxide,
silica-zirconia, silica-alumina, lanthanum glass, borosilicate
glass, soda glass, barium glass, strontium glass, glass ceramics,
aluminosilicate glass, barium boroaluminosilicate glass, strontium
boroaluminosilicate glass, fluoroaluminosilicate glass, calcium
fluoroaluminosilicate glass, strontium fluoroaluminosilicate glass,
barium fluoroaluminosilicate glass, and strontium calcium
fluoroaluminosilicate glass can be mentioned, for example. Also,
these can be used independently or two or more of them may be mixed
for use. The shape of the inorganic filler is not particularly
limited, and amorphous fillers, spherical fillers, etc., can be
appropriately selected for use.
[0089] The inorganic filler may be used after being subjected to
surface pretreatment with a known surface-treating agent such as a
silane coupling agent, as needed, in order to adjust the
miscibility with the polymerizable monomer (b). Examples of the
surface-treating agent include vinyltrimethoxysilane,
vinyltriethoxysilane, vinyltrichlorosilane,
vinyltri(beta-methoxyethoxy)silane,
3-methacryloyloxypropyltrimethoxysilane,
11-methacryloyloxyundecyltrimethoxysilane,
3-glycidoxypropyltrimethoxysilane,
3-mercaptopropyltrimethoxysilane, and
3-aminopropyltriethoxysilane.
[0090] A known method can be used as a method for the surface
treatment, without specific limitation. For example, there are a
method in which the above-mentioned surface-treating agent is added
by spraying while vigorously stirring the inorganic filler, a
method in which, after the inorganic filler and the above-mentioned
surface-treating agent are dispersed or dissolved in a suitable
solvent, the solvent is removed, and a method in which the alkoxy
group in the above-mentioned surface-treating agent is converted
into a silanol group through hydrolysis with an acid catalyst in an
aqueous solution so as to be attached to the surface of the
inorganic filler in the aqueous solution, from which water is
thereafter removed. In any method, heating normally in the range of
50 to 150.degree. C. allows the reaction between the surface of the
inorganic filler and the above-mentioned surface-treating agent to
complete, thereby allowing the surface to be treated.
[0091] An organic-inorganic composite filler can be obtained by
adding a monomer compound to the aforementioned inorganic filler
beforehand, making it into a paste, thereafter polymerizing it, and
crushing it. As the organic-inorganic composite filler, TMPT filler
(obtained by mixing trimethylolpropane methacrylate and silica
filler, polymerizing it, and then crushing it), for example, can be
used. The shape of the organic-inorganic composite filler is not
particularly limited, and the particle size of the filler can be
appropriately selected for use.
[0092] The average particle size of the filler (e) is preferably
0.001 to 50 .mu.m, more preferably 0.001 to 10 .mu.m, from the
viewpoint of the handleability of the polymerizable composition to
be obtained and the mechanical strength of a cured product thereof.
In this description, the average particle size of the filler can be
determined by an arbitrary method known to those skilled in the
art. For example, it can be determined easily using a laser
diffraction particle size distribution analyzer mentioned later in
Examples.
[0093] The content of the filler (e) is not specifically limited,
but is preferably 500 parts by weight or less, more preferably 250
parts by weight or less, further preferably 100 parts by weight or
less, with respect to 100 parts by weight of the total amount of
the acrylic block copolymer (a) and the polymerizable monomer (b),
from the viewpoint of the handleability of the polymerizable
composition to be obtained and the mechanical strength of a cured
product thereof. When the content of the filler (e) is 500 parts by
weight or less, the flexibility of a cured product is maintained at
a good level.
[0094] As long as the effects of the present invention are not
impaired, the polymerizable composition of the present invention
may additionally contain other polymers such as natural rubber,
synthetic polyisoprene rubber, liquid polyisoprene rubber and
hydrogenated products thereof, polybutadiene rubber, liquid
polybutadiene rubber and hydrogenated products thereof,
styrene-butadiene rubber, chloroprene rubber, ethylene-propylene
rubber, acrylic rubber, isoprene-isobutylene rubber,
acrylonitrile-butadiene rubber, and styrene elastomer (e.g.,
polystyrene-polyisoprene-polystyrene block copolymer,
polystyrene-polybutadiene-polystyrene block copolymer,
poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene)
block copolymer,
poly(p-methylstyrene)-polybutadiene-poly(p-methylstyrene) block
copolymer, or hydrogenated products thereof), in order to improve
the properties such as flexibility and fluidity.
[0095] The polymerizable composition of the present invention may
contain a softener, as needed. Examples of the softener include
petroleum-based softeners such as paraffin, naphthene, and aromatic
process oils, and vegetable oil-based softeners such as paraffin,
peanuts oil, and rosin. These softeners may be used individually,
or two or more types of them may be mixed for use. The content of
the softener is not particularly limited, as long as the object of
the present invention is not impaired, but is generally 300 parts
by weight or less, preferably 100 parts by weight or less, with
respect to 100 parts by weight of the total amount of the acrylic
block copolymer (a) and the polymerizable monomer (b).
[0096] Further, the polymerizable composition of the present
invention may contain a known additive within a range that does not
reduce the performance. Examples of the additive include a
polymerization inhibitor, an antioxidant, a pigment, a dye, an
ultraviolet absorber, an organic solvent, and a thickener.
[0097] Examples of the polymerization inhibitor include
hydroquinone, hydroquinone monomethyl ether, dibutyl hydroquinone,
dibutyl hydroquinone monomethyl ether, t-butylcatechol,
2-t-butyl-4,6-dimethylphenol, 2,6-di-t-butylphenol, and
3,5-di-t-butyl-4-hydroxytoluene. The content of the polymerization
inhibitor is preferably 0.001 to 1.0 part by weight with respect to
100 parts by weight of the total amount of the acrylic block
copolymer (a) and the polymerizable monomer (b).
[0098] The polymerizable composition of the present invention has
both good viscosity and forming property at the same time before
curing and thus is excellent in handling property. Further, it
exhibits good adhesive properties to tooth structure, bones, and
metals. Furthermore, a cured product of the polymerizable
composition of the present invention is excellent in flexibility,
transparency, and color stability. Accordingly, the polymerizable
composition of the present invention can be used in applications
that exploit such advantages, particularly, can be applied suitably
to biological tissues (such as teeth and bones, particularly
teeth). As specific applications, the polymerizable composition of
the present invention is optimally used as a temporary cement for
implant use and a mobile tooth-fixing material, and also is
suitably used as a dental cement and a dental composite resin.
[0099] A suitable configuration example of the dental cement is
shown below. The dental cement preferably contains 5 to 500 parts
by weight of the acrylic block copolymer (a), 0.05 to 15 parts by
weight of the polymerization initiator (c), and 0.05 to 20 parts by
weight of the polymerization accelerator (d), with respect to 100
parts by weight of the total amount of the polymerizable monomer
(b), and 0 to 500 parts by weight of the filler (e), with respect
to 100 parts by weight of the total amount of the acrylic block
copolymer (a) and the polymerizable monomer (b). It is more
preferable to contain 10 to 250 parts by weight of the acrylic
block copolymer (a), 0.1 to 10 parts by weight of the
polymerization initiator (c), and 0.1 to 10 parts by weight of the
polymerization accelerator (d), with respect to 100 parts by weight
of the total amount of the polymerizable monomer (b), and 10 to 250
parts by weight of the filler (e), with respect to 100 parts by
weight of the total amount of the acrylic block copolymer (a) and
the polymerizable monomer (b).
[0100] A suitable configuration example of the temporary cement for
implant use is shown below. The temporary cement for implant use
preferably contains 5 to 500 parts by weight of the acrylic block
copolymer (a), 0.05 to 15 parts by weight of the polymerization
initiator (c), and 0.05 to 20 parts by weight of the polymerization
accelerator (d), with respect to 100 parts by weight of the total
amount of the polymerizable monomer (b), and 0 to 250 parts by
weight of the filler (e), with respect to 100 parts by weight of
the total amount of the acrylic block copolymer (a) and the
polymerizable monomer (b). It is more preferable to contain 10 to
250 parts by weight of the acrylic block copolymer (a), 0.1 to 10
parts by weight of the polymerization initiator (c), and 0.1 to 10
parts by weight of the polymerization accelerator (d), with respect
to 100 parts by weight of the total amount of the polymerizable
monomer (b), and 0 to 100 parts by weight of the filler (e), with
respect to 100 parts by weight of the total amount of the acrylic
block copolymer (a) and the polymerizable monomer (b).
[0101] A suitable configuration example of the mobile tooth-fixing
material is shown below. The mobile tooth-fixing material
preferably contains 5 to 500 parts by weight of the acrylic block
copolymer (a), 0.05 to 15 parts by weight of the polymerization
initiator (c), and 0.05 to 20 parts by weight of the polymerization
accelerator (d), with respect to 100 parts by weight of the total
amount of the polymerizable monomer (b), and 0 to 250 parts by
weight of the filler (e), with respect to 100 parts by weight of
the total amount of the acrylic block copolymer (a) and the
polymerizable monomer (b). It is more preferable to contain 10 to
250 parts by weight of the acrylic block copolymer (a), 0.1 to 10
parts by weight of the polymerization initiator (c), and 0.1 to 10
parts by weight of the polymerization accelerator (d), with respect
to 100 parts by weight of the total amount of the polymerizable
monomer (b), and 0 to 100 parts by weight of the filler (e), with
respect to 100 parts by weight of the total amount of the acrylic
block copolymer (a) and the polymerizable monomer (b).
[0102] A suitable configuration example of the dental composite
resin is shown below. The dental composite resin preferably
contains 5 to 250 parts by weight of the acrylic block copolymer
(a), 0.05 to 15 parts by weight of the polymerization initiator
(c), and 0.05 to 20 parts by weight of the polymerization
accelerator (d), with respect to 100 parts by weight of the total
amount of the polymerizable monomer (b), and 0 to 500 parts by
weight of the filler (e), with respect to 100 parts by weight of
the total amount of the acrylic block copolymer (a) and the
polymerizable monomer (b). It is more preferable to contain 10 to
250 parts by weight of the acrylic block copolymer (a), 0.1 to 15
parts by weight of the polymerization initiator (c), and 0.1 to 10
parts by weight of the polymerization accelerator (d), with respect
to 100 parts by weight of the total amount of the polymerizable
monomer (b), and 50 to 250 parts by weight of the filler (e), with
respect to 100 parts by weight of the total amount of the acrylic
block copolymer (a) and the polymerizable monomer (b).
EXAMPLES
[0103] Hereinafter, the present invention is described in detail
with reference to examples and comparative examples. However, the
present invention is not limited to these examples.
[0104] In the following reference examples, the weight-average
molecular weights of sampled polymers (polymers that form each
block) and the acrylic block copolymer (final polymer) were
determined by gel permeation chromatography (hereinafter, referred
to as GPC) in terms of polystyrene. The device and conditions
employed for GPC measurement were as follows.
<Device and Conditions for GPC Measurement>
[0105] Device: GPC system "HLC-8020", manufactured by TOSOH
CORPORATION Separation columns: "TSKgel GMHXL", "G4000HXL", and
"G5000HXL", manufactured by TOSOH CORPORATION, connected in
series
Eluent: Tetrahydrofuran
[0106] Flow rate of eluent: 1.0 ml/minute Detection method:
Differential refractive index (RI) [0107] UV absorbance (Reference
Example 4)
[0108] Further, in the following reference examples, the component
ratio of the respective polymer blocks in the acrylic block
copolymer was determined by .sup.1H-NMR measurement. The device and
condition employed for .sup.1H-NMR measurement were as follows.
<Device and Condition for .sup.1H-NMR Measurement>
[0109] Device: Nuclear magnetic resonance spectrometer "JNM-LA400",
manufactured by JEOL Ltd. Deuterated solvent: Deuterated
chloroform
[0110] The acrylic block copolymer used in this example was
produced as follows.
Reference Example 1
Production of the Acrylic Block Copolymer (a)-1
[0111] (1) A three-way stopcock was attached to a 1 liter
three-necked flask, the inside of which was degassed and
substituted by nitrogen. Thereafter, 390 g of toluene, 1.4 ml of
N,N',N',N'',N''-pentamethyl diethylene triamine, and 18 ml of a
toluene solution containing 11 mmol of
isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum was added
thereto at room temperature, and 1.7 ml of a mixed solution of
cyclohexane and n-hexane containing 2.2 mmol of sec-butyl lithium
was further added thereto. 14 ml of methyl methacrylate was added
thereto, which was allowed to react at room temperature for 1 hour.
1 g of the reaction solution at that time was collected as Sample
1. Subsequently, the internal temperature of the polymerization
solution was cooled to -15.degree. C., and 120 ml of n-butyl
acrylate was added dropwise thereto over 6 hours. After completion
of addition, 1 g of the reaction solution was collected as Sample
2. Subsequently, 14 ml of methyl methacrylate was added thereto,
and the reaction solution was heated to room temperature, followed
by stirring for about 10 hours. 1 g of methanol was added to this
reaction solution to stop the polymerization. The reaction solution
after stopping the polymerization was poured into a large amount of
mixed solution of methanol and water (90 mass % of methanol), and
the deposited white precipitate was recovered as Sample 3.
[0112] (2) Samples 1 to 3 collected or recovered in the
above-mentioned step (1) were subjected to GPC measurement and
.sup.1H-NMR measurement by the above-mentioned method. On the basis
of the results, Mw (weight-average molecular weight), Mw/Mn
(molecular weight distribution), and the mass ratio between methyl
methacrylate polymer (PMMA) block and n-butyl acrylate polymer
(PnBA) block were determined for the polymer and the block
copolymers obtained at each polymerization step. Thus, it was
proved that: the white precipitate finally obtained in the
above-mentioned step (1) was a triblock copolymer composed of
PMMA-PnBA-PMMA; the overall Mw thereof was 85,000; the Mw/Mn was
1.13; and the ratio of the respective polymer blocks was PMMA(10
mass %)-PnBA(80 mass %)-PMMA(10 mass %), (that is, the total of
PMMA was 20 mass %). Further, Sample 1 was PMMA, the Mw thereof was
7,300, and the Mw/Mn thereof was 1.06. Sample 2 was a diblock
copolymer of PMMA-PnBA, the Mw thereof was 77,000, and the Mw/Mn
thereof was 1.16.
Reference Example 2
Production of the Acrylic Block Copolymer (a)-2
[0113] (1) A three-way stopcock was attached to a 1 liter
three-necked flask, the inside of which was degassed and
substituted by nitrogen. Thereafter, 390 g of toluene, 1.4 ml of
N,N',N',N'',N''-pentamethyl diethylene triamine, and 18 ml of a
toluene solution containing 11 mmol of
isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum was added
thereto at room temperature, and 1.7 ml of a mixed solution of
cyclohexane and n-hexane containing 2.2 mmol of sec-butyl lithium
was further added thereto. 35 ml of methyl methacrylate was added
thereto, which was allowed to react at room temperature for 1 hour.
1 g of the reaction solution at that time was collected as Sample
1. Subsequently, the internal temperature of the polymerization
solution was cooled to -15.degree. C., and 75 ml of n-butyl
acrylate was added dropwise thereto over 5 hours. After completion
of addition, 1 g of the reaction solution was collected as Sample
2. Subsequently, 35 ml of methyl methacrylate was added thereto,
and the reaction solution was heated to room temperature, followed
by stirring for about 10 hours. 1 g of methanol was added to this
reaction solution to stop the polymerization. The reaction solution
after stopping the polymerization was poured into a large amount of
mixed solution of methanol and water (90 mass % of methanol), and
the deposited white precipitate was recovered as Sample 3.
[0114] (2) Samples 1 to 3 collected or recovered in the
above-mentioned step (1) were subjected to GPC measurement and
.sup.1H-NMR measurement by the above-mentioned method. On the basis
of the results, Mw, Mw/Mn, and the mass ratio between methyl
methacrylate polymer (PMMA) block and n-butyl acrylate polymer
(PnBA) block were determined for the polymer and the block
copolymers obtained at each polymerization step. Thus, it was
proved that: the white precipitate finally obtained in the
above-mentioned step (1) was a triblock copolymer composed of
PMMA-PnBA-PMMA; the overall Mw thereof was 85,000; the Mw/Mn was
1.03; and the ratio of the respective polymer blocks was PMMA(25
mass %)-PnBA(50 mass %)-PMMA(25 mass %), (that is, the total of
PMMA was 50 mass %). Further, Sample 1 was PMMA, the Mw thereof was
18,000, and the Mw/Mn thereof was 1.05. Sample 2 was a diblock
copolymer of PMMA-PnBA, the Mw thereof was 67,000, and the Mw/Mn
thereof was 1.14.
Reference Example 3
Production of the Acrylic Block Copolymer (a)-3
[0115] (1) A three-way stopcock was attached to a 1 liter
three-necked flask, the inside of which was degassed and
substituted by nitrogen. Thereafter, 390 g of toluene, 0.95 ml of
N,N',N',N'',N''-pentamethyl diethylene triamine, and 12 ml of a
toluene solution containing 11 mmol of
isobutylbis(2,6-di-t-butyl-4-methylphenoxy)aluminum was added
thereto at room temperature, and 1.1 ml of a mixed solution of
cyclohexane and n-hexane containing 2.2 mmol of sec-butyl lithium
was further added thereto. 5 ml of methyl methacrylate was added
thereto, which was allowed to react at room temperature for 1 hour.
1 g of the reaction solution at that time was collected as Sample
1. Subsequently, the internal temperature of the polymerization
solution was cooled to -15.degree. C., and 97 ml of n-butyl
acrylate was added dropwise thereto over 5 hours. After completion
of addition, 1 g of methanol was added to this reaction solution to
stop the polymerization. The reaction solution after stopping the
polymerization was poured into a large amount of mixed solution of
methanol and water (90 mass % of methanol), and the deposited
liquid white precipitate was recovered as Sample 2.
[0116] (2) Samples 1 and 2 collected or recovered in the
above-mentioned step (1) were subjected to GPC measurement and
.sup.1H-NMR measurement by the above-mentioned method. On the basis
of the results, Mw, Mw/Mn, and the mass ratio between methyl
methacrylate polymer (PMMA) block and n-butyl acrylate polymer
(PnBA) block were determined for the polymer and the block
copolymer obtained at each polymerization step. Thus, it was proved
that: the liquid white precipitate finally obtained in the
above-mentioned step (1) was a diblock copolymer composed of
PMMA-PnBA; the overall Mw thereof was 125,000; the Mw/Mn was 1.06;
and the ratio of the respective polymer blocks was PMMA(5 mass
%)-PnBA(95 mass %). Further, Sample 1 was PMMA, the Mw thereof was
6,000, and the Mw/Mn thereof was 1.08.
Reference Example 4
Production of Styrene Block Copolymer 1
[0117] (1) 144 g of alpha-methylstyrene, 251 g of cyclohexane, 47.3
g of methyl cyclohexane, and 6.8 g of tetrahydrofuran were added to
a pressure-resistant container with a stirring device the inside of
which had been substituted by nitrogen. 15.0 ml of sec-butyl
lithium (1.3 M cyclohexane solution) was added to this mixed
solution, which thereafter was polymerized at -10.degree. C. for 5
hours. After 3 hours from the initiation of the polymerization, the
weight-average molecular weight of the poly-alpha-methylstyrene
(polymer block A) was 7800 and the polymerization conversion of the
alpha-methylstyrene was 90%. Subsequently, 40.5 g of butadiene was
added to this reaction solution, which was stirred at -10.degree.
C. for 30 minutes, thereby polymerizing butadiene (forming block
B1). Thereafter, 1680 g of cyclohexane was added thereto. At this
time, the polymerization conversion of the alpha-methylstyrene was
90%, and the 1,4-bond content of the polybutadiene block (B1)
determined by the .sup.1H-NMR measurement was 19 mol %. Next, 230 g
of butadiene was further added to this reaction solution, which was
polymerized at 50.degree. C. for 2 hours. The weight-average
molecular weight of the polybutadiene block (B2) in the block
copolymer (structure: A-B1-B2) obtained by sampling at this time
was 33000, and the 1,4-bond content thereof determined by the
.sup.1H-NMR measurement was 60 mol %.
[0118] (2) Subsequently, in accordance with the method disclosed in
JP 2007-126527, a solution obtained by dissolving 1.2 g of
dichlorodimethylsilane in 30 ml of cyclohexane was added to this
polymerization reaction solution, which was stirred at 50.degree.
C. for 1 hour. Thus, a
poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene)
triblock copolymer was obtained. The coupling efficiency at this
time, as calculated from the UV absorption area ratio of the
coupled product
(poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene)
triblock copolymer: A-B1-B2-X-B2-B1-A) and the unreacted block
copolymer (poly(alpha-methylstyrene)-polybutadiene block copolymer:
A-B1-B2) in GPC, was 97%. Further, as a result of the .sup.1H-NMR
measurement, the content of alpha-methylstyrene polymer block in
the
poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene)
triblock copolymer was 33 wt %, and the 1,4-bond content of the
entire butadiene block (that is, block B1+B2) was 53 mol %.
[0119] (3) A Ziegler-type hydrogenation catalyst formed from nickel
octylate and triethyl aluminum was added to the polymerization
reaction solution obtained by the above-mentioned step (2) under an
atmosphere of hydrogen, which was allowed to undergo a
hydrogenation reaction at 80.degree. C. for 5 hours with a hydrogen
pressure of 0.8 MPa. Thereby, a hydrogenated product of the
poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene)
triblock copolymer (which is hereinafter abbreviated as styrene
block copolymer 1) was obtained. The resultant styrene block
copolymer 1 was subjected to the GPC measurement. As a result, it
was proved that: the main component was a hydrogenated product of
the
poly(alpha-methylstyrene)-polybutadiene-poly(alpha-methylstyrene)
triblock copolymer with Mt (the peak top of the average molecular
weight)=79000, Mn (the number-average molecular weight)=77000, Mw
(the weight-average molecular weight)=78000, and Mw/Mn=1.03, and
the content of the coupled product as determined from the UV (254
nm) absorption area ratio in GPC was 97%. Further, the
hydrogenation rate of the butadiene block B composed of the block
B1 and the block B2 as determined by the .sup.1H-NMR measurement
was 99%.
[0120] Next, the components of the polymerizable compositions of
Examples and
[0121] Comparative Examples are shown below together with
abbreviations.
[0122] <Polymerizable Monomer (b)>
3G: Triethylene glycol dimethacrylate D-2.6E:
2,2-bis(4-methacryloyloxypolyethoxyphenyl)propane TBM: t-Butyl
methacrylate IBM: Isobornyl methacrylate MDP:
10-methacryloyloxydecyl dihydrogen phosphate DD: 1,10-decanediol
dimethacrylate
[0123] <Photopolymerization Initiator (c-1)>
CQ: Camphorquinone
[0124] BAPO: Bis-(2,4,6-trimethylbenzoyl)phenylphosphine oxide
[0125] <Chemical Polymerization Initiator (c-2)>
BPO: Benzoyl peroxide
[0126] <Polymerization Accelerator (d)>
PDE: N,N-dimethylaminobenzoic acid ethyl ester DEPT:
N,N-di(2-hydroxyethyl)-p-toluidine
TEA: Triethanolamine
[0127] TPBSS: Sodium 2,4,6-triisopropylbenzenesulfinate
[0128] <Filler (e)>
[0129] Fillers (e)-1 and (e)-2 were obtained by the following
production method.
[0130] Filler (e)-1:
3-methacryloyloxypropyltrimethoxysilane-treated silica powder
[0131] Silica powder ("KE-P250", manufactured by NIPPON SHOKUBAI
CO., LTD.) was ground with a vibration ball mill. Thus, silica
powder was obtained. 100 g of the resultant silica powder, 0.5 g of
3-aminopropyltriethoxysilane, and 200 ml of toluene were put into a
500 ml one-necked eggplant-shaped flask, which was stirred at room
temperature for 2 hours. Subsequently, toluene was distilled off
under reduced pressure, residue of which was thereafter dried under
vacuum at 40.degree. C. for 16 hours, and further dried under
vacuum at 90.degree. C. for 3 hours. Thus,
3-methacryloyloxypropyltrimethoxysilane-treated silica powder
(filler (e)-1) was obtained. The average particle size of the
filler (e)-1 as measured with a laser diffraction particle size
distribution analyzer ("SALD-2100", manufactured by SHIMADZU
CORPORATION) was 2.4 .mu.m.
[0132] Filler (e)-2:
3-methacryloyloxypropyltrimethoxysilane-treated colloid silica
powder
[0133] 100 g of colloid silica powder ("Aerosil OX50", manufactured
by Japan Aerosil Inc.), 0.5 g of
3-methacryloyloxypropyltrimethoxysilane, and 200 ml of toluene were
put into a 500 ml one-necked eggplant-shaped flask, which was
stirred at room temperature for 2 hours. Subsequently, toluene was
distilled off under reduced pressure, residue of which was
thereafter dried under vacuum at 40.degree. C. for 16 hours, and
further dried under vacuum at 90.degree. C. for 3 hours. Thus,
3-methacryloyloxypropyltrimethoxysilane-treated colloid silica
powder (filler (e)-2) was obtained.
[0134] <Polymerization Inhibitor>
BHT: 3,5-di-t-butyl-4-hydroxytoluene
[0135] The viscosity and forming property of the polymerizable
composition obtained in Examples and Comparative Examples, and the
flexural modulus, toughness, transparency, color stability, and
adhesive properties to tooth structure, metals, and ceramics of a
cured product of the composition were measured or evaluated as
follows.
Test Example 1
Viscosity
[0136] The polymerizable composition was placed on a rheometer
(AR2000, manufactured by TA Instruments Japan Inc.) and the
viscosity was measured using a 20 mm diameter parallel plate while
the temperature was maintained at 25.degree. C. and the plate was
rotated in a constant direction at a shearing speed of 1.0
sec.sup.-1. Those having a viscosity obtained by this measurement
of 50 Pas or less were considered to have excessively high
fluidity, while those having a viscosity of 1000 Pas or more were
considered to have no fluidity, and thus have poor handling
property.
Test Example 2
Forming Property
[0137] A 3 mm diameter circle was drawn on dental mixing paper with
a size of length: 59 mm.times.width: 83 mm, and 0.3 g of the
polymerizable composition was placed inside the circle. It was
erected upright in a constant temperature chamber at 35.degree. C.,
and was allowed to stand still as it was for 3 minutes. Then, the
moving distance of the polymerizable composition from the inside of
the circle was measured. This test was performed 3 times, the
average of the 3 measured values was taken as a flow score (mm).
The greater the flow score, the more likely the polymerizable
composition to flow. Those having a flow score obtained from this
test of 3 mm or more were considered to have no forming property,
and thus have poor handling property.
Test Example 3
Flexural Modulus
[0138] The flexural modulus was evaluated by the bending test in
accordance with ISO4049. That is, the polymerizable composition
produced in each of the following examples was charged into a SUS
mold (width: 2 mm.times.thickness: 2 mm.times.length: 25 mm), and
thereafter it was pressed from above and below each with a slide
glass, and both sides thereof were irradiated with light at 5
points on each side for 20 seconds, using a dental visible light
unit (JET LITE 3000, manufactured by Morita Corporation). Thus, the
polymerizable composition was cured. The resultant cured product
was subjected to the bending test using a universal testing machine
(autograph AG-100kNI, manufactured by SHIMADZU CORPORATION) at a
cross-head speed of 2 mm/min. Thus, the flexural modulus was
measured. In order to ensure excellent flexibility, the flexural
modulus is preferably not more than 1000 MPa.
Test Example 4
Toughness
[0139] In the aforementioned flexural modulus measurement, the test
was continued until the cured product reached the yield point or
was broken. Specimens that were not broken were evaluated as
.smallcircle., and specimens that were broken were evaluated as x.
Specimens that were not broken were determined to have excellent
toughness, while specimens that were broken were determined to have
low toughness and to be fragile.
Test Example 5
Transparency
[0140] The polymerizable composition was charged into a SUS mold
(size: 2 mm.times.diameter: 20 mm), and thereafter it was pressed
from above and below each with a slide glass, and both sides
thereof were irradiated with light at 6 points on each side for 20
seconds, using a dental visible light unit (JET LITE 3000,
manufactured by Morita Corporation). Thus, the polymerizable
composition was cured. The transparency (.DELTA.L) of the obtained
cured product was measured using a spectrocolorimeter (CM-3610d,
light source: D65, manufactured by KONICA MINOLTA HOLDINGS, INC.).
In order to ensure high aesthetic value, the transparency
(.DELTA.L) is required to be at least 25.
Test Example 6
Color Stability
[0141] The specimen produced in Test example 5 was subjected to
color measurement using a spectrocolorimeter (CM-3610d, light
source: D65, manufactured by KONICA MINOLTA HOLDINGS, INC.), the
result of which was taken as the chromaticity before test.
Subsequently, the specimen was immersed in distilled water at
70.degree. C. for 10 days, and thereafter was subjected to color
measurement again, the result of which was taken as the
chromaticity after test. The change of the chromaticity after test
from the chromaticity before test was evaluated as a .DELTA.E
value. The .DELTA.E value is defined by the following formula. In
order to ensure color stability, the .DELTA.E value is required to
be 5 or less. The higher the color stability in this test, the more
excellent the water resistance.
.DELTA.E={(L*1-L*2).sup.2+(a*1-a*2).sup.2+(b*1-b*2).sup.2}.sup.1/2,
where L*1, a*1, b*1, L*2, a*2, b*2 are values indicating the
chromaticity (L*, a*, b*), as measured using a spectrocolorimeter,
in color systems of L*, a*, b*. The chromaticity (L*1, a*1, b*1)
denote values after immersion in water at 70.degree. C., and the
chromaticity (L*2, a*2, b*2) denote values before immersion in
water at 70.degree. C.
Test Example 7
Tensile Bond Strength to Tooth Structure (Bovine Enamel/Dentin)
[0142] The labial surface of a bovine mandibular incisor was ground
with #80 silicon carbide paper (manufactured by NIHON KENSHI CO.,
LTD.) under running water to form a flat surface of enamel or a
flat surface of dentin. Each flat surface was further ground with
#1000 silicon carbide paper (manufactured by NIHON KENSHI CO.,
LTD.) under running water, and thereafter water on the surface was
blown off using a dental air syringe.
[0143] An adhesive tape with a thickness of about 150 .mu.m having
a 3 mm diameter circular hole was attached to each flat surface,
thereby defining an adhesive area. The following dental adhesive
agent 1 was applied to the inside of the circular hole using a
brush, which was left standing for 30 seconds. Thereafter, it was
dried with an air syringe until the fluidity of the applied dental
adhesive agent 1 was lost. Subsequently, the polymerizable
composition was charged into the circular hole on the surface
coated with the dental adhesive agent 1, and excess of the
polymerizable composition overflowing the circular hole was removed
with a razor blade so that a smooth surface was obtained.
Thereafter, the polymerizable composition was cured by irradiation
with light for 30 seconds using a dental visible light unit (JET
LITE 3000, manufactured by Morita Corporation). One end (circular
cross section) of a stainless steel cylindrical rod (diameter: 7
mm, length: 2.5 cm) was bonded to the resultant cured product in
which an unpolymerized layer of the polymerizable composition was
still left, using a commercially available dental resin cement
(Panavia 21, manufactured by KURARAY MEDICAL INC.). After bonding,
this sample was allowed to stand still for 30 minutes at room
temperature, which was then immersed in distilled water. 5 bond
test samples were produced in total, and all the samples immersed
in distilled water were kept in a constant temperature chamber
maintained at 37.degree. C. for 24 hours.
[0144] The tensile bond strength of the above-mentioned bond test
samples was measured using a universal testing machine (autograph
AG-100kNI, manufactured by SHIMADZU CORPORATION) at a cross-head
speed of 2 mm/min, and the average of the results was taken as the
tensile bond strength.
[0145] Dental Adhesive Agent 1:
A mixture composed of
TABLE-US-00001 bis-GMA (2,2-bis[4-(3-methacryloyloxy- 5 parts by
weight 2-hydroxypropoxy)phenyl]propane) #801
(l,2-bis(3-methacryloyloxy- 25 parts by weight
2-hydroxypropoxy)ethane) HEMA (2-hydroxyethyl methacrylate) 25
parts by weight MDP 10 parts by weight CQ 1.5 parts by weight BAPO
1.0 part by weight PDE 1.0 part by weight DEPT 1.5 parts by weight
BHT 0.05 part by weight Distilled water 15.0 parts by weight
Ethanol 15.0 parts by weight
Test Example 8
Adhesive Properties to Metals
[0146] A titanium strip (Titanium 100, manufactured by SHOFU INC.,
titanium content: at least 99.5%) with dimensions: 10
mm.times.thickness: 5 mm was ground with #1000 silicon carbide
paper (manufactured by NIHON KENSHI CO., LTD.) under running water
to form a smooth surface, and thereafter water on the surface was
blown off with a dental air syringe.
[0147] The following dental adhesive agent 2 was applied to the
smooth surface of the titanium strip, followed by air drying.
Thereafter, an adhesive tape with a thickness of about 150 .mu.m
having a 5 mm diameter circular hole was attached thereto, thereby
defining an adhesive area. Subsequently, the polymerizable
composition was charged into the circular hole on the surface
coated with the dental adhesive agent 2, and excess of the
polymerizable composition overflowing the circular hole was removed
with a razor blade so that a smooth surface was obtained.
Thereafter, the polymerizable composition was cured by irradiation
with light for 30 seconds using a dental visible light unit (JET
LITE 3000, manufactured by Morita Corporation). One end (circular
cross section) of a stainless steel cylindrical rod (diameter: 7
mm, length: 2.5 cm) was bonded to the resultant cured product in
which an unpolymerized layer of the polymerizable composition was
still left, using a commercially available dental resin cement
(Panavia 21, manufactured by KURARAY MEDICAL INC.). After bonding,
this sample was allowed to stand still for 30 minutes at room
temperature, which was then immersed in distilled water. 5 bond
test samples were produced in total, and all the samples immersed
in distilled water were kept in a constant temperature chamber
maintained at 37.degree. C. for 24 hours.
[0148] The tensile bond strength of the above-mentioned bond test
samples was measured using a universal testing machine (autograph
AG-100kNI, manufactured by SHIMADZU CORPORATION) at a cross-head
speed of 2 mm/min, and the average of the results was taken as the
tensile bond strength.
[0149] Dental Adhesive Agent 2:
A mixture composed of
TABLE-US-00002 Acetone 99.0%
6-(4-vinylbenzyl-n-propyl)amino-1,3,5-triazine-2,4-dithion 0.6%
10-methacryloyloxydecyl dihydrogen phosphate 0.4%
Test Example 9
Adhesive Properties to Ceramics
[0150] The above-mentioned test was conducted in the same manner as
in Test example 8 except that Titanium 100 used in Test example 8
was changed to a ceramic strip (VITA CELAY, manufactured by VITA),
and the dental adhesive agent 2 was changed to the following dental
adhesive agent 3.
[0151] Dental Adhesive Agent 3:
A mixture composed of
TABLE-US-00003 Ethanol 95.0%
3-methacryloyloxypropyltrimethoxysilane 5.0%
10-methacryloyloxydecyl dihydrogen phosphate 1.0%
Examples 1 to 16 and Comparative Examples 1 to 6
Preparation of Polymerizable Composition
[0152] The raw materials shown in Table 1 to Table 4 were mixed at
room temperature to prepare a paste A (and a paste B), and then the
properties thereof were investigated in accordance with the method
described above in Test examples 1 to 9. Table 1 to Table 4 show
the results.
TABLE-US-00004 TABLE 1 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex.
1 2 3 4 5 6 7 8 9 10 11 Raw Acrylic block copolymer (a)-1 45 40 45
45 30 25 materials Acrylic block copolymer (a)-2 30 30 10 Acrylic
block copolymer (a)-3 70 60 30 Styrene block copolymer 1 5 Styrene
block copolymer 2 .sup.1) 5 3G (b)-1 15 10 15 15 15 10 15 15 15 10
10 D2.6E (b)-2 5 5 5 TBM (b)-3 40 25 30 30 55 50 35 20 20 IBM (b)-4
25 10 15 10 10 MDP (b)-5 10 10 5 5 10 10 10 DD (b-)6 5 5 CQ (c-1)-1
1.0 0.5 0.5 1.5 1.5 1.0 0.5 0.5 BAPO (c-1)-2 2.5 1.0 2.0 2.0 3.0
1.5 3.0 2.0 1.5 2.0 2.0 PDE (d)-1 1.0 0.5 0.5 1.5 1.5 1.0 0.5 0.5
Filler (e)-1 25 10 50 Filler (e)-2 10 5.0 3.0 5.0 5.0 10 10 BHT
0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 Properties
Viscosity (Pa s) 750 680 790 870 780 790 810 910 780 870 920
Forming property: 0 0 0 0 1 0 1 0 0 0 0 Flow score (mm) Flexural
modulus (MPa) 120 180 240 390 330 440 90 380 310 580 670 Toughness
.smallcircle. .smallcircle. .smallcircle. .smallcircle.
.smallcircle. .smallcircle. .smallcircle. .smallcircle.
.smallcircle. .smallcircle. .smallcircle. Transparency .DELTA.L 50
48 42 35 53 39 41 34 47 38 34 Color stability .DELTA.E 1.6 1.7 1.4
1.9 1.4 1.7 2.4 2.1 1.4 1.8 1.5 Tensile bond strength to 9.5 8.2
10.3 11.3 9.2 9.5 7.8 8.1 9.3 8.9 8.3 bovine enamel (MPa) Tensile
bond strength to 7.1 7.2 8.5 8.3 7.7 8.4 7.1 7.6 8.2 8.1 7.9 bovine
dentin (MPa) Tensile bond strength to 7.3 7.2 8.6 8.9 7.4 8.2 7.2
7.7 8.3 7.8 7.6 titanium alloy (MPa) Tensile bond strength to 8.7
8.9 9.8 9.9 9.5 9.7 8.1 8.3 8.9 8.3 8.1 ceramics (MPa) .sup.1)
Styrene block copolymer 2: Hydrogenated product of
polystyrene-polybutadiene-polystyrene (SEPTON8007, manufactured by
KURARAY CO., LTD.)
TABLE-US-00005 TABLE 2 C. EX. 1 C. EX. 2 C. EX. 3 Raw Acrylic
polymer 1 .sup.2) 20 materials Acrylic copolymer 1 .sup.3) 10 3G
(b)-1 15 15 15 TBM (b)-3 85 65 75 CQ (c-1) 1.0 1.0 1.0 BAPO (c-1)
1.0 1.0 1.0 PDE (d)-1 1.0 1.0 1.0 Filler (e)-1 20 Filler (e)-2 5
BHT 0.05 0.05 0.05 Properties Viscosity (Pa s) 260 4,800 7,300
Forming property: 18 0 0 Flow score (mm) Flexural modulus (MPa)
2,800 1,800 2,200 Toughness x x x Transparency .DELTA.L 37 18 13
Color stability .DELTA.E 2.3 2.5 2.9 Tensile bond strength 2.4 2.8
2.9 to bovine enamel (MPa) Tensile bond strength 1.8 2.1 2.5 to
bovine dentin (MPa) Tensile bond strength 2.1 2.3 2.2 to titanium
alloy (MPa) Tensile bond strength 2.5 2.3 2.6 to ceramics (MPa)
.sup.2) Acrylic polymer 1: Polybutylmethacrylate (Hi Pearl M-6003,
manufactured by Negami chemical industrial co., ltd, molecular
weight: 250,000 to 350,000) .sup.3) Acrylic copolymer 1:
Poly(methyl methacrylate/ethyl methacrylate) (Hi Pearl M-4501,
manufactured by Negami chemical industrial co., ltd, molecular
weight: 650,000 to 1,000,000)
TABLE-US-00006 TABLE 3 EX. 12 EX. 13 EX. 14 EX. 15 EX. 16 EX. 17
EX. 18 A B A B A B A B A B A B A B Raw Acrylic block copolymer
(a)-1 45 45 40 40 materials Acrylic block copolymer (a)-2 30 30 30
30 20 Acrylic block copolymer (a)-3 70 70 60 60 70 3G (b)-1 15 15
15 15 15 15 15 10 15 15 20 20 15 5 D2.6E (b)-2 5 10 10 10 15 TBM
(b)-3 40 40 25 25 55 55 45 55 55 IBM (b)-4 10 20 5 5 5 10 10 MDP
(b)-5 10 10 15 10 CQ (c-1)-1 0.25 0.25 0.5 0.25 0.5 BAPO (c-1)-2
2.5 1.5 1.5 1.5 1.0 1.5 2.0 BPO (c-2) 1.5 2.0 1.5 2.0 1.5 3.0 2.5
PDE (d)-1 0.5 0.5 0.5 0.25 0.5 DEPT (d)-2 1.0 1.5 1.0 1.5 1.0 1.0
1.5 TEA (d)-3 0.1 0.25 0.5 0.1 0.1 TPBSS (d)-4 0.1 0.25 0.5 0.1 0.1
Filler (e)-1 25 15 20 10 25 20 Filler (e)-2 5 5 3 3 5 5 5 5 BHT 0.5
0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Properties
Viscosity (Pa s) 760 860 870 930 790 920 810 Forming property: 0 0
0 0 0 0 0 Flow score (mm) Flexural modulus (MPa) 150 320 290 420
110 190 260 Toughness .smallcircle. .smallcircle. .smallcircle.
.smallcircle. .smallcircle. .smallcircle. .smallcircle.
Transparency .DELTA.L 50 36 51 41 42 30 38 Color stability .DELTA.E
2.5 2.7 2.3 2.4 2.9 2.7 2.8 Tensile bond strength to 9.8 11.5 9.3
10.3 8.1 9.1 9.2 bovine enamel (MPa) Tensile bond strength to 8.1
8.4 8.1 8.9 8.0 8.8 8.7 bovine dentin (MPa) Tensile bond strength
to 8.6 8.8 7.7 9.1 8.2 8.9 8.6 titanium alloy (MPa) Tensile bond
strength to 9.3 9.8 8.6 10.3 9.4 9.8 9.7 ceramics (MPa)
TABLE-US-00007 TABLE 4 EX. 12 EX. 13 EX. 14 EX. 15 EX. 16 A B A B A
B A B A B Raw Acrylic block copolymer (a)-1 45 25 45 25 materials
Acrylic polymer 1 .sup.2) 20 20 Acrylic copolymer .sup.3) 10 10
Styrene block copolymer 1 5 Styrene block copolymer 2 .sup.1) 5 3G
(b)-1 15 15 15 10 15 15 15 15 15 15 TBM (b)-3 40 25 40 25 85 85 65
65 75 75 IBM (b)-4 20 25 DD (b-)6 10 5 CQ (c-1)-1 0.25 0.25 0.25
BAPO (c-1)-2 2.5 2.5 1.5 1.5 1.5 BPO (c-2) 1.5 1.5 1.5 1.5 1.5 PDE
(d)-1 0.5 0.5 0.5 DEPT (d)-2 1.0 1.0 1.0 1.0 1.0 TEA (d)-3 0.25
0.25 0.25 TPBSS (d)-4 0.25 0.25 0.25 Filler (e)-1 20 20 20 20 20 20
Filler (e)-2 5 5 5 5 5 5 5 5 BHT 0.05 0.05 0.05 0.05 0.05 0.05 0.05
0.05 0.05 0.05 Properties Viscosity (Pa s) 800 920 280 5,200 7,600
Forming property: 0 0 14 0 0 Flow score (mm) Flexural modulus (MPa)
230 290 2,900 1,310 2,400 Toughness .smallcircle. .smallcircle. x x
x Transparency .DELTA.L 47 45 28 19 16 Color stability .DELTA.E 2.8
2.7 2.1 2.8 3.1 Tensile bond strength to 9.0 9.3 2.6 3.1 2.8 bovine
enamel (MPa) Tensile bond strength to 8.3 8.4 2.0 2.2 2.3 bovine
dentin (MPa) Tensile bond strength to 8.2 8.1 2.0 2.1 2.4 titanium
alloy (MPa) Tensile bond strength to 9.1 9.5 2.4 2.5 2.9 ceramics
(MPa) .sup.1) Refer to the note below Table 1 .sup.2) , .sup.3)
Refer to the notes below Table 2
[0153] It can be seen from the results shown in Table 1 to Table 4
that the polymerizable composition containing an acrylic block
copolymer of each Example has appropriate viscosity and forming
property and excellent handling property before curing compared to
the polymerizable compositions containing no acrylic block
copolymer of the Comparative Examples. Further, the polymerizable
composition containing an acrylic block copolymer of each Example
has low flexural modulus, and shows no breakage, thus having
excellent flexibility. Furthermore, the polymerizable composition
containing an acrylic block copolymer of each Example has high
transparency and shows less color change, resulting in excellent
aesthetic value. Moreover, the polymerizable composition containing
an acrylic block copolymer of each Example has adhesive properties
to tooth structure and adhesive properties to titanium and
ceramics. From above, it can be seen that the polymerizable
composition containing an acrylic block copolymer according to the
present invention can be suitably applied to biological tissues and
is optimally used as a temporary cement for implant use and a
mobile tooth-fixing material.
INDUSTRIAL APPLICABILITY
[0154] The polymerizable composition of the present invention can
be suitably applied to biological tissues (such as teeth and bones,
particularly teeth). Specifically, it is optimally used as a
temporary cement for implant use and a mobile tooth-fixing
material. It also can be suitably used as a dental cement and a
dental composite resin.
* * * * *