U.S. patent application number 16/001142 was filed with the patent office on 2018-10-04 for polycarbonate resin composition for thin optical component, and method for producing thin optical component.
This patent application is currently assigned to MITSUBISHI CHEMICAL CORPORATION. The applicant listed for this patent is MITSUBISHI CHEMICAL CORPORATION, MITSUBISHI ENGINEERING-PLASTICS CORPORATION. Invention is credited to Toshiki MONDEN, Ryouhei NISHIHARA.
Application Number | 20180282541 16/001142 |
Document ID | / |
Family ID | 59014201 |
Filed Date | 2018-10-04 |
United States Patent
Application |
20180282541 |
Kind Code |
A1 |
NISHIHARA; Ryouhei ; et
al. |
October 4, 2018 |
POLYCARBONATE RESIN COMPOSITION FOR THIN OPTICAL COMPONENT, AND
METHOD FOR PRODUCING THIN OPTICAL COMPONENT
Abstract
An object of the present invention is to provide a polycarbonate
resin composition for a thin optical component, which polycarbonate
resin composition has favorable fluidity as well as excellent
strength. This object is achieved by a polycarbonate resin
composition for a thin optical component, which composition
contains: 100 parts by mass of an aromatic polycarbonate resin (A)
having a viscosity average molecular weight (Mv) of 10,000 to
15,000; and 2 to 100 parts by mass of an aromatic polycarbonate
copolymer (B) including a carbonate structural unit (i) represented
by a particular Formula (1) and a carbonate structural unit (ii)
represented by a particular Formula (2), wherein the ratio of the
carbonate structural unit (i) to a total of 100 mol % of the
carbonate structural unit (i) and the carbonate structural unit
(ii) in the aromatic polycarbonate copolymer (B) is more than 10
mol % and less than 39 mol %.
Inventors: |
NISHIHARA; Ryouhei;
(Hiratsuka-shi, JP) ; MONDEN; Toshiki;
(Chiyoda-ku, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI CHEMICAL CORPORATION
MITSUBISHI ENGINEERING-PLASTICS CORPORATION |
Chiyoda-ku
Minato-ku |
|
JP
JP |
|
|
Assignee: |
MITSUBISHI CHEMICAL
CORPORATION
Chiyoda-ku
JP
MITSUBISHI ENGINEERING-PLASTICS CORPORATION
Minato-ku
JP
|
Family ID: |
59014201 |
Appl. No.: |
16/001142 |
Filed: |
June 6, 2018 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2016/086761 |
Dec 9, 2016 |
|
|
|
16001142 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G 64/04 20130101;
C08J 2369/00 20130101; C08J 2469/00 20130101; B29K 2069/00
20130101; C08K 5/524 20130101; B29K 2105/0005 20130101; C08L
2205/025 20130101; B29C 45/0001 20130101; C08G 65/34 20130101; C08J
5/00 20130101; C08K 5/005 20130101; C08G 64/06 20130101; C08L
2201/10 20130101; C08L 69/00 20130101 |
International
Class: |
C08L 69/00 20060101
C08L069/00; C08K 5/524 20060101 C08K005/524; C08K 5/00 20060101
C08K005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2015 |
JP |
2015-242170 |
Dec 18, 2015 |
JP |
2015-247592 |
Dec 21, 2015 |
JP |
2015-248695 |
Claims
1. A polycarbonate resin composition for a thin optical component,
said composition comprising: 100 parts by mass of an aromatic
polycarbonate resin (A) having a viscosity average molecular weight
(Mv) of 10,000 to 15,000; and 2 to 100 parts by mass of an aromatic
polycarbonate copolymer (B) including a carbonate structural unit
(i) represented by the following Formula (1): ##STR00019## (wherein
in Formula (1), R.sup.1 represents C.sub.3-C.sub.24 alkyl or
alkenyl; R.sup.2 and R.sup.3 each independently represent a
C.sub.1-C.sub.15 monovalent hydrocarbon group; and a and b each
independently represent an integer of 0 to 4) and a carbonate
structural unit (ii) represented by the following Formula (2):
##STR00020## wherein the ratio of the carbonate structural unit (i)
to a total of 100 mol % of the carbonate structural unit (i) and
the carbonate structural unit (ii) in the aromatic polycarbonate
copolymer (B) is more than 10 mol % and less than 39 mol %.
2. The polycarbonate resin composition for a thin optical component
according to claim 1, further comprising 0.01 to 1 part by mass of
polyalkylene glycol or a fatty acid ester thereof (C) with respect
to a total of 100 parts by mass of the aromatic polycarbonate resin
(A) and the aromatic polycarbonate copolymer (B).
3. The polycarbonate resin composition for a thin optical component
according to claim 1, further comprising 0.005 to 0.5 part by mass
of a heat stabilizer (D) with respect to a total of 100 parts by
mass of the aromatic polycarbonate resin (A) and the aromatic
polycarbonate copolymer (B).
4. The polycarbonate resin composition for a thin optical component
according to claim 3, wherein the heat stabilizer (D) is a
phosphorus-based antioxidant.
5. A method for producing a thin optical component, said method
comprising the step of molding the polycarbonate resin composition
according to claim 1.
6. The method for producing a thin optical component according to
claim 5, wherein the thin optical component is a light guide plate
having a thickness of not more than 1 mm.
7. A method for producing a thin optical component having a
thickness of not more than 1 mm, said method comprising the step of
performing injection molding of the polycarbonate resin composition
according to claim 1 at 260 to 380.degree. C.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of International Application
PCT/JP2016/086761, filed on Dec. 9, 2016, and designated the U.S.,
and claims priority from Japanese Patent Application 2015-242170
which was filed on Dec. 11, 2015, Japanese Patent Application
2015-247592 which was filed on Dec. 18, 2015 and Japanese Patent
Application 2015-248695 which was filed on Dec. 21, 2015, the
entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a polycarbonate resin
composition for a thin optical component, and a method for
producing a thin optical component. More specifically, the present
invention relates to a polycarbonate resin composition for a thin
optical component, having favorable fluidity as well as excellent
strength, and a method for producing a thin optical component.
BACKGROUND ART
[0003] In liquid crystal display devices used for personal
computers, mobile phones, and the like, planar light source devices
are incorporated for complying with demands for thinning, weight
reduction, power saving, and achievement of higher definition. For
the purpose of uniformly and efficiently guiding incident light to
the liquid crystal display side, such planar light source devices
are provided with a light guide plate having a wedge-shaped
cross-section having a uniformly inclined plane on one side, or a
flat-plate-shaped light guide plate. In some cases, the light guide
plate has an irregular pattern formed on its surface, for imparting
light-scattering function.
[0004] Such a light guide plate is obtained by injection molding of
a thermoplastic resin, and the irregular pattern described above is
imparted by transfer of irregularity formed on a surface of an
insert. Conventionally, light guide plates have been molded from
resin materials such as polymethyl methacrylate (PMMA). However, in
recent years, since display devices are required to be capable of
displaying clearer images, and heat generated in the vicinity of
light sources tends to increase the temperature in the devices,
those resin materials are becoming replaced by polycarbonate resin
materials having higher heat resistance.
[0005] In addition, in recent years, even further thinning has been
demanded especially for mobile phones, and further thinning of
light guide plates has also been demanded. Although PMMA has an
advantage in that thin-wall molding is easily possible because of
its excellent fluidity, it has a drawback in that its low impact
resistance easily causes cracking upon molding or handling, and
upon incorporation into a liquid crystal display device. Although
polycarbonate resins have excellent impact resistance, their
fluidity is low compared to PMMA. Therefore, molding of very thin
light guide plates has been very difficult therewith. In view of
this, as described in Patent Document 1 and Patent Document 2, a
composition for a light guide plate, which composition achieves
more than a certain level of impact resistance while suppressing a
decrease in the fluidity by inclusion of a polycarbonate resin
having a molecular weight within a particular range, has been
proposed. However, because of the recent increasing demand for the
thinning, the molecular weights of polycarbonate resins have become
even lower for further improvement of the fluidity, causing a
problem that cracking occurs upon molding or handling, or upon
incorporation into a liquid crystal display device.
[0006] On the other hand, a method for improving moldability by
further addition of another dihydroxy compound as monomers to a
conventional bisphenol A polycarbonate resin has been proposed. For
example, Patent Document 3 describes a polycarbonate resin having
improved fluidity containing bisphenol A and bisphenol E. Patent
Documents 4 and 5 also describe polycarbonate resins having
improved fluidity using particular bisphenol compounds. However,
such polycarbonate resins also have a problem in that they are
impractical because of their extremely low heat resistance, and
that, since their fluidity and impact resistance are insufficient
for obtaining light guide plates, thin molded articles cannot be
obtained.
PRIOR ART DOCUMENTS
Patent Documents
[Patent Document 1] JP 2010-37380 A
[Patent Document 2] JP 2013-139097 A
[Patent Document 3] JP 5-1144 A
[Patent Document 4] JP 6-128371 A
[Patent Document 5] JP 59-131623 A
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0007] The present invention was made in view of such facts, and
aims to provide a polycarbonate resin composition for a thin
optical component, which composition has favorable fluidity as well
as favorable strength, and a method for producing a thin optical
component.
Means for Solving the Problems
[0008] The present inventors intensively studied to solve the above
problems, and as a result, discovered that a polycarbonate resin
composition for a thin optical component having high fluidity and
high strength can be obtained by inclusion of an aromatic
polycarbonate copolymer (B) containing a particular amount of a
structural unit derived from a particular aromatic dihydroxy
compound, in an aromatic polycarbonate resin (A) having a viscosity
average molecular weight (Mv) of 10,000 to 15,000, thereby
completing the present invention. That is, the present invention is
constituted by the following [1] to [7].
[1] A polycarbonate resin composition for a thin optical component,
the composition comprising:
[0009] 100 parts by mass of an aromatic polycarbonate resin (A)
having a viscosity average molecular weight (Mv) of 10,000 to
15,000; and
[0010] 2 to 100 parts by mass of an aromatic polycarbonate
copolymer (B) including a carbonate structural unit (i) represented
by the following Formula (1):
##STR00001##
(wherein in Formula (1), R.sup.1 represents C.sub.8-C.sub.24 alkyl
or alkenyl; R.sup.2 and R.sup.3 each independently represent a
C.sub.1-C.sub.15 monovalent hydrocarbon group; and a and b each
independently represent an integer of 0 to 4) and a carbonate
structural unit (ii) represented by the following Formula (2):
##STR00002##
wherein the ratio of the carbonate structural unit (i) to a total
of 100 mol % of the carbonate structural unit (i) and the carbonate
structural unit (ii) in the aromatic polycarbonate copolymer (B) is
more than 10 mol % and less than 39 mol %. [2] The polycarbonate
resin composition for a thin optical component according to [1],
further comprising 0.01 to 1 part by mass of polyalkylene glycol or
a fatty acid ester thereof (C) with respect to a total of 100 parts
by mass of the aromatic polycarbonate resin (A) and the aromatic
polycarbonate copolymer (B). [3] The polycarbonate resin
composition for a thin optical component according to [1] or [2],
further comprising 0.005 to 0.5 part by mass of a heat stabilizer
(D) with respect to a total of 100 parts by mass of the aromatic
polycarbonate resin (A) and the aromatic polycarbonate copolymer
(B). [4] The polycarbonate resin composition for a thin optical
component according to [3], wherein the heat stabilizer (D) is a
phosphorus-based antioxidant. [5] A method for producing a thin
optical component, the method comprising the step of molding the
polycarbonate resin composition recited in any one of [1] to [4].
[6] The method for producing a thin optical component according to
[5], wherein the thin optical component is a light guide plate
having a thickness of not more than 1 mm. [7] A method for
producing a thin optical component having a thickness of not more
than 1 mm, the method comprising the step of performing injection
molding of the polycarbonate resin composition recited in any one
of [1] to [4] at 260 to 380.degree. C.
Effect of the Invention
[0011] By the polycarbonate resin composition for a thin optical
component of the present invention, the strength of a molded
article after molding can be increased while fluidity sufficient
for molding of a thin optical member can be maintained. Therefore,
cracking, which may occur in a thin optical member, can be
remarkably reduced.
MODE FOR CARRYING OUT THE INVENTION
[0012] The present invention is described below in more detail by
way of embodiments, examples, and the like. However, the present
invention should not be interpreted as being limited to the
embodiments, examples, and the like described below.
[0013] Unless otherwise specified, the term "to" in the present
description is used such that the values described before and after
it are included as the lower limit and the upper limit,
respectively. Unless otherwise specified, the term "part" means
part by mass, which is expressed on a mass basis.
[0014] The components constituting the polycarbonate resin
composition for a thin optical component, the thin optical
component, and the like in the present invention are described
below in detail.
[Aromatic Polycarbonate Resin (A)]
[0015] The type of the aromatic polycarbonate resin (A) used for
the polycarbonate resin composition for a thin optical component of
the present invention is not limited. The aromatic polycarbonate
resin (A) is a polycarbonate resin that is different from the
aromatic polycarbonate copolymer (B). A single type of aromatic
polycarbonate resin (A) may be used, or two or more types of
aromatic polycarbonate resins (A) may be used in an arbitrary
combination at arbitrary ratios.
[0016] Examples of the aromatic polycarbonate resin (A) of the
present invention include aromatic polycarbonate resins prepared by
reacting an aromatic dihydroxy compound with a carbonate-forming
compound. In this process, in addition to the aromatic dihydroxy
compound and the carbonate-forming compound, a polyhydroxy compound
and/or the like may be reacted. The aromatic polycarbonate resin
(A) may be either linear or branched. The polycarbonate resin (A)
may be a homopolymer, which is composed of a single kind of repeat
units, or may be a copolymer, which includes two or more kinds of
repeat units. This copolymer may be selected from various forms of
copolymers including random copolymers and block copolymers. Such
polycarbonate polymers are normally thermoplastic resins.
[0017] Examples of the aromatic dihydroxy compound as a material of
the aromatic polycarbonate resin (A) include: dihydroxybenzenes
such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (that is,
resorcinol), and 1,4-dihydroxybenzene; dihydroxybiphenyls such as
2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, and
4,4'-dihydroxybiphenyl; dihydroxynaphthalenes such as
2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene,
1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene,
1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene,
1,7-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene;
dihydroxydiaryl ethers such as 2,2'-dihydroxydiphenyl ether,
3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether,
4,4'-dihydroxy-3,3'-dimethyldiphenyl ether,
1,4-bis(3-hydroxyphenoxy)benzene, and
1,3-bis(4-hydroxyphenoxy)benzene;
[0018] bis(hydroxyaryl)alkanes such as
2,2-bis(4-hydroxyphenyl)propane (that is, bisphenol A),
1,1-bis(4-hydroxyphenyl)propane,
2,2-bis(3-methyl-4-hydroxyphenyl)propane,
2,2-bis(3-methoxy-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-methoxy-4-hydroxyphenyl)propane,
1,1-bis(3-tert-butyl-4-hydroxyphenyl)propane,
2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane,
2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane,
2-(4-hydroxyphenyl)-2-(3-cyclohexyl-4-hydroxyphenyl)propane,
.alpha.,.alpha.'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
bis(4-hydroxyphenyl)methane, bis(4-hydroxyphenyl)cyclohexylmethane,
bis(4-hydroxyphenyl)phenylmethane,
bis(4-hydroxyphenyl)(4-propenylphenyl)methane,
bis(4-hydroxyphenyl)diphenylmethane,
bis(4-hydroxyphenyl)naphthylmethane,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)-1-phenylethane,
1,1-bis(4-hydroxyphenyl)-1-naphthylethane,
1,1-bis(4-hydroxyphenyl)butane, 2,2-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)pentane, 1,1-bis(4-hydroxyphenyl)hexane,
and 2,2-bis(4-hydroxyphenyl)hexane;
[0019] bis(hydroxyaryl)cycloalkanes such as
1,1-bis(4-hydroxyphenyl)cyclopentane,
1,1-bis(4-hydroxyphenyl)cyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,4-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,5-dimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxy-3,5-dimethylphenyl)-3,3,5-trimethylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3-propyl-5-methylcyclohexane,
1,1-bis(4-hydroxyphenyl)-3-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-4-tert-butyl-cyclohexane,
1,1-bis(4-hydroxyphenyl)-3-phenylcyclohexane, and
1,1-bis(4-hydroxyphenyl)-4-phenylcyclohexane;
[0020] cardo structure-containing bisphenols such as
9,9-bis(4-hydroxyphenyl)fluorene and
9,9-bis(4-hydroxy-3-methylphenyl)fluorene; dihydroxydiaryl sulfides
such as 4,4'-dihydroxydiphenyl sulfide and
4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; dihydroxydiaryl
sulfoxides such as 4,4'-dihydroxydiphenyl sulfoxide and
4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide; and
dihydroxydiaryl sulfones such as 4,4'-dihydroxydiphenyl sulfone and
4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfone.
[0021] Among these, bis(hydroxyaryl)alkanes are preferred, and
bis(4-hydroxyphenyl)alkanes are more preferred. In particular, from
the viewpoint of impact resistance and heat resistance,
2,2-bis(4-hydroxyphenyl)propane (that is, bisphenol A) is
preferred.
[0022] A single type of aromatic dihydroxy compound may be used, or
two or more types of aromatic dihydroxy compounds may be used in an
arbitrary combination at arbitrary ratios.
[0023] Regarding the monomers used as a material of the aromatic
polycarbonate resin (A) of the present invention, examples of the
carbonate-forming compound include carbonyl halides and carbonate
esters. A single type of carbonate-forming compound may be used, or
two or more types of carbonate-forming compounds may be used in an
arbitrary combination at arbitrary ratios.
[0024] Specific examples of the carbonyl halides include phosgene;
haloformates such as bischloroformate bodies of dihydroxy
compounds, and monochloroformate bodies of dihydroxy compounds.
[0025] Specific examples of the carbonate esters include diaryl
carbonates such as diphenyl carbonate and ditolyl carbonate;
dialkyl carbonates such as dimethyl carbonate and diethyl
carbonate; and biscarbonate bodies of dihydroxy compounds,
monocarbonate bodies of dihydroxy compounds, and carbonate bodies
of dihydroxy compounds such as cyclic carbonates.
Method for Producing Aromatic Polycarbonate Resin (A)
[0026] The method for producing the aromatic polycarbonate resin
(A) used in the present invention is not limited, and an arbitrary
method may be employed therefor. Examples of the method include
interfacial polymerization, melt transesterification, pyridine
method, ring-opening polymerization of cyclic carbonate compounds,
and solid-phase transesterification of prepolymers. Preferred
methods among these are concretely described below.
Interfacial Polymerization
[0027] First, a case where the aromatic polycarbonate resin is
produced by interfacial polymerization is described. In the
interfacial polymerization, the pH is usually maintained at not
less than 9 in the presence of an organic solvent inert to the
reaction, and an aqueous alkali solution. After reacting an
aromatic dihydroxy compound with a carbonate-forming compound
(preferably phosgene), interfacial polymerization is carried out in
the presence of a polymerization catalyst to obtain an aromatic
polycarbonate resin. If necessary, in the reaction system, a
molecular weight modifier (terminating agent) may be allowed to be
present, and, for prevention of oxidation of the aromatic dihydroxy
compound, an antioxidant may be allowed to present.
[0028] The aromatic dihydroxy compound and the carbonate-forming
compound are as described above. Among carbonate-forming compounds,
phosgene is preferably used. In cases where phosgene is used, the
method is specifically called the phosgene method.
[0029] Examples of the organic solvent inert to the reaction
include chlorinated hydrocarbons such as dichloromethane,
1,2-dichloroethane, chloroform, monochlorobenzene, and
dichlorobenzene; and aromatic hydrocarbons such as benzene,
toluene, and xylene. A single type of organic solvent may be used,
or two or more types of organic solvents may be used in an
arbitrary combination at arbitrary ratios.
[0030] Examples of the alkali compound contained in the aqueous
alkali solution include alkali metal compounds such as sodium
hydroxide, potassium hydroxide, lithium hydroxide, and sodium
hydrogen carbonate; and alkaline earth metal compounds. Sodium
hydroxide and potassium hydroxide are especially preferred. A
single type of alkali compound may be used, or two or more types of
alkali compounds may be used in an arbitrary combination at
arbitrary ratios.
[0031] The concentration of the alkali compound in the aqueous
alkali solution is not limited. The alkali compound is usually used
in an amount of 5 to 10% by mass for the purpose of controlling the
pH of the aqueous alkali solution to 10 to 12 for the reaction. In
cases where phosgene is blown, for controlling the pH of the
aqueous phase to 10 to 12, preferably 10 to 11, the molar ratio
between the bisphenol compound and the alkali compound is
preferably adjusted to usually 1:1.9 or more, especially 1:2.0 or
more, and usually 1:3.2 or less, especially 1:2.5 or less.
[0032] Examples of the polymerization catalyst include aliphatic
tertiary amines such as trimethylamine, triethylamine,
tributylamine, tripropylamine, and trihexylamine; alicyclic
tertiary amines such as N,N'-dimethylcyclohexylamine and
N,N'-diethylcyclohexylamine; aromatic tertiary amines such as
N,N'-dimethylaniline and N,N'-diethylaniline; quaternary ammonium
salts such as trimethylbenzylammonium chloride, tetramethylammonium
chloride, and triethylbenzylammonium chloride; pyridine; guanine;
and salts of guanidine. A single type of polymerization catalyst
may be used, or two or more types of polymerization catalysts may
be used in an arbitrary combination at arbitrary ratios.
[0033] Examples of the molecular weight modifier include aromatic
phenols having a monovalent phenolic hydroxyl group; aliphatic
alcohols such as methanol and butanol; mercaptan; and phthalic
imide. Aromatic phenols are especially preferred. Specific examples
of such aromatic phenols include alkyl-substituted phenols such as
m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol,
p-tert-butylphenol, and p-long-chain alkyl-substituted phenols;
vinyl-containing phenols such as isopropenylphenol;
epoxy-containing phenols; and carboxyl-containing phenols such as
o-hydroxybenzoic acid and 2-methyl-6-hydroxyphenylacetic acid. A
single type of molecular weight modifier may be used, or two or
more types of molecular weight modifiers may be used in an
arbitrary combination at arbitrary ratios.
[0034] The amount of the molecular weight modifier used is usually
not less than 0.5 mole, preferably not less than 1 mole, and
usually not more than 50 moles, preferably not more than 30 moles,
with respect to 100 moles of the aromatic dihydroxy compound. In
cases where the amount of the molecular weight modifier is within
this range, thermal stability and hydrolysis resistance of the
thermoplastic resin composition can be increased.
[0035] In the reaction, a reaction substrate(s), reaction
medium/media, catalyst(s), additive(s), and/or the like may be
mixed in an arbitrary order as long as a desired polycarbonate
resin can be obtained. An appropriate order may be arbitrarily set.
For example, in cases where phosgene is used as the
carbonate-forming compound, a molecular weight modifier may be
mixed at an arbitrary timing between the reaction of the aromatic
dihydroxy compound with phosgene (phosgenation) and the beginning
of the polymerization reaction.
[0036] The reaction temperature is usually 0 to 40.degree. C., and
the reaction time is usually several minutes (for example, 10
minutes) to several hours (for example, 6 hours).
Melt Transesterification
[0037] A case where the aromatic polycarbonate resin is produced by
melt transesterification is described below. In the melt
transesterification, transesterification reaction between, for
example, a diester carbonate and a dihydroxy compound is
performed.
[0038] The aromatic dihydroxy compound is as described above.
[0039] On the other hand, examples of the diester carbonate include
dialkyl carbonate compounds such as dimethyl carbonate, diethyl
carbonate, and di-tert-butyl carbonate; diphenyl carbonate; and
substituted diphenyl carbonates such as ditolyl carbonate. Among
these, diphenyl carbonate and substituted diphenyl carbonates are
preferred. Diphenyl carbonates are more preferred. A single type of
diester carbonate may be used, or two or more types of diester
carbonates may be used in an arbitrary combination at arbitrary
ratios.
[0040] The ratio between the aromatic dihydroxy compound and the
diester carbonate is not limited as long as a desired polycarbonate
resin can be obtained. The amount of the diester carbonate used is
preferably not less than an equimolar amount, more preferably not
less than 1.01 moles, with respect to 1 mole of the aromatic
dihydroxy compound. The upper limit is usually 1.30 moles. In cases
where the ratio is within this range, the amount of terminal
hydroxyl groups can be adjusted to within a preferred range.
[0041] In an aromatic polycarbonate resin, the amount of its
terminal hydroxyl groups tends to have a significant influence on
the thermal stability, hydrolytic stability, color tone, and the
like. Thus, the amount of terminal hydroxyl groups may be adjusted
by an arbitrary known method, if necessary. In the
transesterification reaction, an aromatic polycarbonate resin
having a controlled amount of terminal hydroxyl groups can be
usually obtained by controlling the mixing ratio between the
diester carbonate and the aromatic dihydroxy compound, the degree
of pressure reduction during the transesterification reaction,
and/or the like. This operation usually also enables control of the
molecular weight of the aromatic polycarbonate resin obtained.
[0042] In cases where the amount of terminal hydroxyl groups is
controlled by the control of the mixing ratio between the diester
carbonate and the aromatic dihydroxy compound, the mixing ratio is
as described above.
[0043] Examples of more positive control methods include a method
in which a terminating agent is separately mixed during the
reaction. Examples of the terminating agent in this process include
monovalent phenols, monovalent carboxylic acids, and diester
carbonates. A single type of terminating agent may be used, or two
or more types of terminating agents may be used in an arbitrary
combination at arbitrary ratios.
[0044] Usually, in cases where the aromatic polycarbonate resin is
produced by melt transesterification, a transesterification
catalyst is used. An arbitrary transesterification catalyst may be
used. In particular, an alkali metal compound(s) and/or an alkaline
earth metal compound(s) is/are preferably used. In addition, a
basic compound(s) such as a basic boron compound(s), basic
phosphorus compound(s), basic ammonium compound(s), and/or amine
compound(s) may be supplementarily used in combination. A single
type of transesterification catalyst may be used, or two or more
types of transesterification catalysts may be used in an arbitrary
combination at arbitrary ratios.
[0045] In the melt transesterification, the reaction temperature is
usually 100 to 320.degree. C. The reaction is usually carried out
under a reduced pressure of not more than 2 mmHg. More
specifically, the operation may be carried out by allowing melt
polycondensation reaction to proceed under the above conditions
while removing by-products such as aromatic hydroxy compounds.
[0046] The melt polycondensation reaction may be carried out by
either a batch method or a continuous method. In cases where the
reaction is carried out by a batch method, a reaction substrate(s),
reaction medium/media, catalyst(s), additive(s), and/or the like
may be mixed in an arbitrary order as long as a desired aromatic
polycarbonate resin can be obtained. An appropriate order may be
arbitrarily set. In particular, taking into account the stability
and the like of the aromatic polycarbonate resin and the
thermoplastic resin composition, the melt polycondensation reaction
is preferably carried out by a continuous method.
[0047] In the melt transesterification, a catalyst deactivator may
be used, if necessary. As the catalyst deactivator, a compound that
neutralizes the transesterification catalyst may be arbitrarily
used. Examples of the catalyst deactivator include
sulfur-containing acidic compounds and derivatives thereof. A
single type of catalyst deactivator may be used, or two or more
types of catalyst deactivators may be used in an arbitrary
combination at arbitrary ratios.
[0048] The amount of the catalyst deactivator used is usually not
less than 0.5 equivalent, preferably not less than 1 equivalent,
and usually not more than 10 equivalents, preferably not more than
5 equivalents, with respect to the alkali metal or alkaline earth
metal contained in the transesterification catalyst. Further, the
amount of the catalyst deactivator is usually not less than 1 ppm,
and usually not more than 100 ppm, preferably not more than 20 ppm,
with respect to the aromatic polycarbonate resin.
Viscosity Average Molecular Weight of Aromatic Polycarbonate Resin
(A)
[0049] The viscosity average molecular weight [Mv] as calculated
from the solution viscosity of the aromatic polycarbonate resin (A)
used in the present invention is usually 10,000 to 15,000. In cases
where the viscosity average molecular weight is not less than the
lower limit of this range, the mechanical strength of the
polycarbonate resin composition for a thin optical component of the
present invention can be further increased, and therefore the
strength of the thin optical component such as a light guide plate
obtained by molding of the composition can be increased, so that
the component becomes less likely to be cracked. In cases where the
viscosity average molecular weight is not more than the upper limit
of this range, a decrease in the fluidity of the polycarbonate
resin composition for a thin optical component of the present
invention can be suppressed, so that the moldability can be
increased. From such a point of view, the viscosity average
molecular weight [Mv] of the aromatic polycarbonate resin (A) is
preferably not less than 10,500, more preferably not less than
11,000, and preferably not more than 14,500, more preferably not
more than 14,000, still more preferably not more than 13,500,
especially preferably not more than 13,000.
[0050] Two or more kinds of aromatic polycarbonate resins having
different viscosity average molecular weights may be used as a
mixture. In such a case, an aromatic polycarbonate resin having a
viscosity average molecular weight that is outside the preferred
range may be mixed.
[0051] In the present invention, the viscosity average molecular
weight [Mv] means a value calculated by determining the limiting
viscosity [.eta.] (unit, dl/g) at a temperature of 20.degree. C.
using an Ubbelohde viscometer with methylene chloride as a solvent,
and applying the resulting value to the Schnell's viscosity
equation, that is, .eta.=1.23.times.10.sup.-4 Mv.sup.0.83. The
limiting viscosity [.eta.] is a value obtained by measuring the
specific viscosity [.eta..sub.sp] at each solution concentration
[C] (g/dl) and applying the resulting value to the following
equation.
##STR00003##
[0052] The concentration of terminal hydroxyl groups in the
polycarbonate resin (A) is arbitrary, and may be appropriately
selected. It is usually not more than 1000 ppm, preferably not more
than 800 ppm, more preferably not more than 600 ppm. By this, the
residence heat stability of the polycarbonate resin composition for
a thin optical component of the present invention can be further
increased. Regarding the lower limit, the residence heat stability
is usually not less than 10 ppm, preferably not less than 30 ppm,
more preferably not less than 40 ppm. By this, a decrease in the
molecular weight can be suppressed, and the color tone of the
polycarbonate resin composition for a thin optical component of the
present invention can be further improved.
[0053] The terminal hydroxyl group concentration is represented by
the mass, expressed in ppm units, of the terminal hydroxyl groups
with respect to the mass of the aromatic polycarbonate resin. For
the measurement, colorimetry by the titanium tetrachloride/acetic
acid method (the method described in Macromol. Chem. 88 215 (1965))
is used.
[Aromatic Polycarbonate Copolymer (B)]
[0054] The polycarbonate resin composition for a thin optical
component of the present invention contains an aromatic
polycarbonate copolymer (B) composed of a carbonate structural unit
(i) represented by the following Formula (1) and a carbonate
structural unit (ii) represented by the following Formula (2). By
blending such an aromatic polycarbonate copolymer (B) with the
aromatic polycarbonate resin (A), a remarkably favorable balance
among the fluidity, moldability, and strengths such as the impact
strength, bending strength, and cyclic fatigue strength of the
polycarbonate resin composition for a thin optical component of the
present invention can be achieved, so that a thin optical component
which is less likely to be cracked upon molding and has high
strength can be obtained.
##STR00004##
[0055] In Formula (1), R.sup.1 represents C.sub.8-C.sub.24 alkyl or
alkenyl. By having such an aliphatic hydrocarbon chain-containing
substituent such as an alkyl group or alkenyl group having eight or
more carbon atoms, when the aromatic polycarbonate copolymer (B) is
blended with the aromatic polycarbonate resin (A) to prepare a
polycarbonate resin composition for a thin optical component,
entangling of polymer chains of the aromatic polycarbonate resin
during melting can be moderately inhibited to reduce friction
between the polymer chains, so that high fluidity can be achieved.
From such a point of view, the carbon number of the alkyl group or
alkenyl group in R.sup.1 in the Formula (1) is more preferably not
less than 9, still more preferably not less than 10, especially
preferably not less than 11. On the other hand, the carbon number
of the alkyl group or alkenyl group in R.sup.1 in the carbonate
structural unit of the Formula (1) is not more than 24. In cases
where the long-chain aliphatic chain is too long, heat resistance
and mechanical properties are remarkably low, and compatibility
with the polycarbonate resin (A) is low, so that mechanical
properties and transparency may be deteriorated, which is not
preferred. From such a point of view, the carbon number of the
R.sup.1 is more preferably not more than 22, still more preferably
not more than 18, especially preferably not more than 16.
[0056] Examples of the C.sub.8-C.sub.24 alkyl include linear or
branched alkyl groups, and alkyl groups partially having a cyclic
structure. In particular, for effective enhancement of fluidity of
the aromatic polycarbonate resin of the present invention, the
C.sub.8-C.sub.24 alkyl is preferably a linear or branched alkyl
group.
[0057] Specific examples of the linear alkyl groups include
n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl,
n-tetradecyl, n-pentadecyl, n-hexadecyl, n-heptadecyl, n-octadecyl,
n-nonadecyl, n-icosyl, n-icosyl, n-henicosyl, n-docosyl,
n-tricosyl, and n-tetracosyl. n-Nonyl, n-decyl, n-undecyl,
n-dodecyl, n-hexadecyl, and n-octadecyl are preferred. n-Nonyl,
n-decyl, n-undecyl, and n-dodecyl are more preferred. n-Dodecyl is
especially preferred. By the presence of such an alkyl group,
fluidity and impact resistance of the aromatic polycarbonate resin
composition of the present invention can be more effectively
increased.
[0058] Specific examples of the branched alkyl groups include
methylheptyl, methyloctyl, methylnonyl, methyldecyl, methylundecyl,
methyldodecyl, methyltridecyl, methyltetradecyl, methylpentadecyl,
methylhexadecyl, methylheptadecyl, methyloctadecyl,
methylnonadecyl, methylicosyl, methylicosyl, methylhenicosyl,
methyldocosyl, methyltricosyl,
[0059] dimethylheptyl, dimethyloctyl, dimethylnonyl, dimethyldecyl,
dimethylundecyl, dimethyldodecyl, dimethyltridecyl,
dimethyltetradecyl, dimethylpentadecyl, dimethylhexadecyl,
dimethylheptadecyl, dimethyloctadecyl, dimethylnonadecyl,
dimethylicosyl, dimethylicosyl, dimethylhenicosyl,
dimethyldocosyl,
[0060] trimethylheptyl, trimethyloctyl, trimethylnonyl,
trimethyldecyl, trimethylundecyl, trimethyldodecyl,
trimethyltridecyl, trimethyltetradecyl, trimethylpentadecyl,
trimethylhexadecyl, trimethylheptadecyl, trimethyloctadecyl,
trimethylnonadecyl, trimethylicosyl, trimethylicosyl,
trimethylhenicosyl,
[0061] ethylhexyl, ethylheptyl, ethyloctyl, ethylnonyl, ethyldecyl,
ethylundecyl, ethyldodecyl, ethyltridecyl, ethyltetradecyl,
ethylpentadecyl, ethylhexadecyl, ethylheptadecyl, ethyloctadecyl,
ethylnonadecyl, ethylicosyl, ethylicosyl, ethylhenicosyl,
ethyldocosyl,
[0062] propylhexyl, propylheptyl, propyloctyl, propylnonyl,
propyldecyl, propylundecyl, propyldodecyl, propyltridecyl,
propyltetradecyl, propylpentadecyl, propylhexadecyl,
propylheptadecyl, propyloctadecyl, propylnonadecyl, propylicosyl,
propylicosyl, propylhenicosyl,
[0063] butylhexyl, butylheptyl, butyloctyl, butylnonyl, butyldecyl,
butylundecyl, butyldodecyl, butyltridecyl, butyltetradecyl,
butylpentadecyl, butylhexadecyl, butylheptadecyl, butyloctadecyl,
butylnonadecyl, butylicosyl, and butylicosyl.
[0064] In the above examples of branched alkyl groups, the
position(s) of branching is/are arbitrary.
[0065] The alkenyl group is not limited as long as it has a
structure wherein one or more carbon-carbon double bonds are
included in the structure of a linear alkyl group or branched alkyl
group described above. Specific examples of the alkenyl group
include octenyl, nonenyl, decenyl, undecenyl, dodecenyl,
tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl,
octadecenyl, nonadecenyl, icosenyl, henicosenyl, docosenyl,
tricosenyl, tetracosenyl, and 4,8,12-trimethyltridecyl.
[0066] R.sup.2 and R.sup.3 in the carbonate structural unit (i) of
Formula (1) represent C.sub.1-C.sub.15 monovalent hydrocarbon
groups. By having the C.sub.1-C.sub.15 monovalent hydrocarbon
groups, the aromatic polycarbonate resin composition for a thin
optical component of the present invention can have increased
fluidity, strength, hardness, chemical resistance, and the like.
Preferred examples of the C.sub.1-C.sub.15 monovalent hydrocarbon
groups include C.sub.1-C.sub.15 alkyl groups and C.sub.2-C.sub.15
alkenyl groups. These may be linear, branched, or cyclic. Examples
of such monovalent hydrocarbon groups include methyl, ethyl,
propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl,
pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl,
n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl,
phenyl, and tolyl. Among these, methyl is preferred.
[0067] a and b in the carbonate structural unit (i) each
independently represent an integer of 0 to 4, preferably 0 to 2,
more preferably 0 or 1, still more preferably 0.
[0068] Specific examples of the carbonate structural unit (i)
include the structural units represented by the following Formulae
(3) to (12). Among these, the structural units of Formulae (3) to
(10) are more preferred; the structural units of Formulae (4) to
(7) are still more preferred; the structural units of Formulae (4)
and (6) are especially preferred; and the structural unit of
Formula (6) is most preferred.
##STR00005## ##STR00006##
[0069] Specific examples of the carbonate structural unit (i)
represented by the Formula (1) in the aromatic polycarbonate
copolymer (B) contained in the polycarbonate resin composition for
a thin optical component of the present invention include the
structural units represented by the following Formulae (13) to
(15). Among these, the structural unit represented by Formula (13)
is more preferred since it tends to increase the thermal stability.
However, the isomeric structures of Formulae (14) and (15) may also
be included at arbitrary ratios.
##STR00007##
[0070] From such a point of view, more preferred specific examples
of the carbonate structure (i) include the structural units
represented by the following Formulae (16) to (25). Among these,
the structural units of Formulae (16) to (23) are more preferred;
the structural units of Formulae (17) to (20) are still more
preferred; the structural units of Formulae (17) and (19) are
especially preferred; and the structural unit of Formula (19) is
most preferred.
##STR00008## ##STR00009##
[0071] The carbonate structural unit (ii) represented by the
Formula (2) in the aromatic polycarbonate copolymer (B) in the
polycarbonate resin composition for a thin optical component of the
present invention is preferably the bisphenol A-derived structural
unit represented by the following Formula (26). However, the
isomeric structural unit represented by Formula (27) may also be
included at an arbitrary ratio.
##STR00010##
[0072] In the aromatic polycarbonate copolymer (B) contained in the
polycarbonate resin composition for a thin optical component of the
present invention, the ratio of the carbonate structural unit (i)
represented by Formula (1) is more than 10 mol % and less than 39
mol % with respect to a total of 100 mol % of the carbonate
structural unit (i) represented by the Formula (1) and the
carbonate structural unit (ii) represented by the Formula (2) in
the aromatic polycarbonate copolymer (B). The ratio of the
carbonate structural unit represented by the Formula (1) is
preferably not less than 12 mol %, more preferably not less than 14
mol %, still more preferably not less than 16 mol %, especially
preferably not less than 18 mol %, most preferably not less than 22
mol %. Further, the ratio is preferably not more than 38.5 mol %,
more preferably not more than 38 mol %, still more preferably not
more than 37.5 mol %, especially preferably not more than 37 mol %,
most preferably not more than 36.5 mol %.
Molecular Weight of Aromatic Polycarbonate Copolymer (B)
[0073] The molecular weight of the aromatic polycarbonate copolymer
(B) contained in the polycarbonate resin composition for a thin
optical component of the present invention is not limited, and
usually 5000 to 50,000 in terms of the viscosity average molecular
weight (Mv) as calculated from the solution viscosity. In cases
where the viscosity average molecular weight is less than the lower
limit, the mechanical properties of the polycarbonate resin
composition for a thin optical component of the present invention
are likely to be poor, and the aromatic polycarbonate copolymer (B)
tends to cause bleeding. In cases where the viscosity average
molecular weight exceeds the upper limit, the fluidity tends to be
insufficient, which is not preferred. From such a point of view,
the viscosity average molecular weight (Mv) of the aromatic
polycarbonate copolymer (B) is preferably not less than 9,000, more
preferably not less than 10,000, still more preferably not less
than 11,000, and preferably not more than 30,000, more preferably
not more than 25,000, still more preferably not more than 20,000,
especially preferably not more than 18,000.
[0074] The definition and the measurement method for the viscosity
average molecular weight (Mv) of the aromatic polycarbonate
copolymer (B) are the same as those for the viscosity average
molecular weight (Mv) of the aromatic polycarbonate resin (A)
described above.
Amount of Terminal Hydroxyl Groups in Aromatic Polycarbonate
Copolymer (B)
[0075] The amount of terminal hydroxyl groups in the aromatic
polycarbonate copolymer (B) contained in the polycarbonate resin
composition for a thin optical component of the present invention
is not limited, and usually 10 to 2000 ppm. The amount is
preferably not less than 20 ppm, more preferably not less than 50
ppm, still more preferably not less than 100 ppm. On the other
hand, the amount is preferably not more than 1500 ppm, more
preferably not more than 1000 ppm, still more preferably not more
than 700 ppm. In cases where the amount of terminal hydroxyl groups
is not less than the lower limit of this range, the hue and the
productivity of the aromatic polycarbonate copolymer (B) of the
present invention can be further improved. In cases where the
amount is not more than the upper limit of this range, the thermal
stability and the moist heat stability of the polycarbonate resin
composition for a thin optical component of the present invention
can be further improved.
[0076] The unit of the terminal hydroxyl group concentration is the
same as in the measurement method and the definition for the
terminal hydroxyl groups in the aromatic polycarbonate resin (A)
described above.
Method for Producing Aromatic Polycarbonate Copolymer (B)
[0077] The aromatic polycarbonate copolymer (B) is obtained by
polycondensation of an aromatic dihydroxy compound(s) necessary for
forming the carbonate structures with a carbonate-forming
compound(s). Examples of the aromatic dihydroxy compound necessary
for forming the carbonate structural unit (i) include the aromatic
dihydroxy compounds represented by the following Formula (28).
##STR00011##
[0078] Specific examples of the aromatic dihydroxy compound
necessary for forming the carbonate structural unit (i) include the
aromatic dihydroxy compounds represented by the following Formulae
(29) to (31). Among these, the aromatic dihydroxy compounds
represented by Formula (29) are more preferred since they tend to
increase the thermal stability. However, the aromatic dihydroxy
compounds of Formulae (30) and (31) may also be included at
arbitrary ratios.
##STR00012##
[0079] In Formulae (28) to (31), the definitions and preferred
examples of R.sup.1, R.sup.2, R.sup.3, a, and b are the same as
those of the carbonate structural unit (i) represented by the
Formula (1). From such a point of view, more preferred specific
examples of the aromatic dihydroxy compound necessary for forming
the carbonate structural unit (i) include the following:
[0080] 1,1-bis(4-hydroxyphenyl)octane,
1,1-bis(2-hydroxyphenyl)octane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)octane,
1,1-bis(4-hydroxyphenyl)nonane, 1,1-bis(2-hydroxyphenyl)nonane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)nonane,
1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(2-hydroxyphenyl)decane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)decane,
1,1-bis(4-hydroxyphenyl)undecane, 1,1-bis(2-hydroxyphenyl)undecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)undecane,
1,1-bis(4-hydroxyphenyl)dodecane, 1,1-bis(2-hydroxyphenyl)dodecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)dodecane,
1,1-bis(4-hydroxyphenyl)tridecane,
1,1-bis(2-hydroxyphenyl)tridecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)tridecane,
1,1-bis(4-hydroxyphenyl)tetradecane,
1,1-bis(2-hydroxyphenyl)tetradecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)tetradecane,
1,1-bis(4-hydroxyphenyl)pentadecane,
1,1-bis(2-hydroxyphenyl)pentadecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)pentadecane,
1,1-bis(4-hydroxyphenyl)hexadecane,
1,1-bis(2-hydroxyphenyl)hexadecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)hexadecane,
1,1-bis(4-hydroxyphenyl)heptadecane,
1,1-bis(2-hydroxyphenyl)heptadecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)heptadecane,
1,1-bis(4-hydroxyphenyl)octadecane,
1,1-bis(2-hydroxyphenyl)octadecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)octadecane,
1,1-bis(4-hydroxyphenyl)nonadecane,
1,1-bis(2-hydroxyphenyl)nonadecane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)nonadecane,
[0081] 1,1-bis(4-hydroxyphenyl)icosane,
1,1-bis(2-hydroxyphenyl)icosane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)icosane,
1,1-bis(4-hydroxyphenyl)henicosane,
1,1-bis(2-hydroxyphenyl)henicosane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)henicosane,
1,1-bis(4-hydroxyphenyl)docosane, 1,1-bis(2-hydroxyphenyl)docosane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)docosane,
1,1-bis(4-hydroxyphenyl)tricosane,
1,1-bis(2-hydroxyphenyl)tricosane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)tricosane,
1,1-bis(4-hydroxyphenyl)tetracosane,
1,1-bis(2-hydroxyphenyl)tetracosane,
1-(2-hydroxyphenyl)-1-(4-hydroxyphenyl)tetracosane,
1,1-bis(3-methyl-4-hydroxyphenyl)octane,
1,1-bis(2-hydroxy-3-methylphenyl)octane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)octane,
1,1-bis(3-methyl-4-hydroxyphenyl)nonane,
1,1-bis(2-hydroxy-3-methylphenyl)nonane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)nonane,
1,1-bis(3-methyl-4-hydroxyphenyl)decane,
1,1-bis(2-hydroxy-3-methylphenyl)decane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)decane,
1,1-bis(3-methyl-4-hydroxyphenyl)undecane,
1,1-bis(2-hydroxy-3-methylphenyl)undecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)undecane,
1,1-bis(3-methyl-4-hydroxyphenyl)dodecane,
1,1-bis(2-hydroxy-3-methylphenyl)dodecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)dodecane,
1,1-bis(3-methyl-4-hydroxyphenyl)tridecane,
1,1-bis(2-hydroxy-3-methylphenyl)tridecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)tridecane,
1,1-bis(3-methyl-4-hydroxyphenyl)tetradecane,
1,1-bis(2-hydroxy-3-methylphenyl)tetradecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)tetradecane,
[0082] 1,1-bis(3-methyl-4-hydroxyphenyl)pentadecane,
1,1-bis(2-hydroxy-3-methylphenyl)pentadecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)pentadecane,
1,1-bis(3-methyl-4-hydroxyphenyl)hexadecane,
1,1-bis(2-hydroxy-3-methylphenyl)hexadecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)hexadecane,
1,1-bis(3-methyl-4-hydroxyphenyl)heptadecane,
1,1-bis(2-hydroxy-3-methylphenyl)heptadecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)heptadecane,
1,1-bis(3-methyl-4-hydroxyphenyl)octadecane,
1,1-bis(2-hydroxy-3-methylphenyl)octadecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)octadecane,
1,1-bis(3-methyl-4-hydroxyphenyl)nonadecane,
1,1-bis(2-hydroxy-3-methylphenyl)nonadecane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)nonadecane,
1,1-bis(3-methyl-4-hydroxyphenyl)icosane,
1,1-bis(2-hydroxy-3-methylphenyl)icosane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)icosane,
1,1-bis(3-methyl-4-hydroxyphenyl)henicosane,
1,1-bis(2-hydroxy-3-methylphenyl)henicosane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)henicosane,
1,1-bis(3-methyl-4-hydroxyphenyl)docosane,
1,1-bis(2-hydroxy-3-methylphenyl)docosane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)docosane,
1,1-bis(3-methyl-4-hydroxyphenyl)tricosane,
1,1-bis(2-hydroxy-3-methylphenyl)tricosane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)tricosane,
[0083] 1,1-bis(3-methyl-4-hydroxyphenyl)tetracosane,
1,1-bis(2-hydroxy-3-methylphenyl)tetracosane,
1-(2-hydroxy-3-methyl-phenyl)-1-(3-methyl-4-hydroxyphenyl)tetracosane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)octane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)nonane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)decane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)undecane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)dodecane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)tridecane,
1,1-bis(3,5-dimethyl-4-hydroxyphenyl)tetradecane,
1,1-bis(3-ethyl-4-hydroxyphenyl)nonane,
1,1-bis(3-ethyl-4-hydroxyphenyl)decane,
1,1-bis(3-ethyl-4-hydroxyphenyl)undecane,
1,1-bis(3-ethyl-4-hydroxyphenyl)dodecane,
1,1-bis(3-propyl-4-hydroxyphenyl)nonane,
1,1-bis(3-propyl-4-hydroxyphenyl)decane,
1,1-bis(3-propyl-4-hydroxyphenyl)undecane,
1,1-bis(3-propyl-4-hydroxyphenyl)dodecane,
1,1-bis(3-butyl-4-hydroxyphenyl)nonane,
1,1-bis(3-butyl-4-hydroxyphenyl)decane,
1,1-bis(3-butyl-4-hydroxyphenyl)undecane,
1,1-bis(3-butyl-4-hydroxyphenyl)dodecane,
1,1-bis(3-nonyl-4-hydroxyphenyl)nonane,
1,1-bis(3-nonyl-4-hydroxyphenyl)decane,
1,1-bis(3-nonyl-4-hydroxyphenyl)undecane, and
1,1-bis(3-nonyl-4-hydroxyphenyl)dodecane.
[0084] Among these, from the viewpoint of the thermal stability,
hue, and impact strength, the aromatic dihydroxy compound necessary
for forming the carbonate structural unit (i) of the aromatic
polycarbonate copolymer (B) is more preferably
1,1-bis(4-hydroxyphenyl) octane, 1,1-bis(4-hydroxyphenyl)nonane,
1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)undecane,
1,1-bis(4-hydroxyphenyl)dodecane,
1,1-bis(4-hydroxyphenyl)tridecane,
1,1-bis(4-hydroxyphenyl)tetradecane,
1,1-bis(4-hydroxyphenyl)pentadecane,
1,1-bis(4-hydroxyphenyl)hexadecane,
1,1-bis(4-hydroxyphenyl)heptadecane,
1,1-bis(4-hydroxyphenyl)octadecane, or
1,1-bis(4-hydroxyphenyl)nonadecane, still more preferably
1,1-bis(4-hydroxyphenyl)decane, 1,1-bis(4-hydroxyphenyl)undecane,
1,1-bis(4-hydroxyphenyl)dodecane, or
1,1-bis(4-hydroxyphenyl)tridecane, most preferably
1,1-bis(4-hydroxyphenyl)dodecane.
[0085] Specific examples of the aromatic dihydroxy compound
necessary for forming the carbonate structural unit (ii) include
2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(2-hydroxyphenyl)propane,
and 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane. Among these,
from the viewpoint of the thermal stability, hue, and impact
strength, 2,2-bis(4-hydroxyphenyl)propane (the so-called bisphenol
A) is more preferred.
[0086] Examples of the carbonate-forming compound include carbonyl
halides and carbonate esters. A single type of carbonate-forming
compound may be used, or two or more types of carbonate-forming
compounds may be used in an arbitrary combination at arbitrary
ratios.
[0087] Specific examples of the carbonyl halides include phosgene;
haloformates such as bischloroformate bodies of dihydroxy
compounds, and monochloroformate bodies of dihydroxy compounds.
[0088] Specific examples of the carbonate esters include the
compounds represented by the following Formula (32), for example,
aryl carbonates; dialkyl carbonates; biscarbonate bodies of
dihydroxy compounds; monocarbonate bodies of dihydroxy compounds;
and carbonate bodies of dihydroxy compounds such as cyclic
carbonates.
##STR00013##
[0089] In Formula (32), R.sup.4 and R.sup.5 each independently
represent C.sub.1-C.sub.30 alkyl, aryl, or arylalkyl. Hereinafter,
when R.sup.4 and R.sup.5 are alkyl and/or arylalkyl, the carbonate
ester may be referred to as dialkyl carbonate, and when R.sup.4 and
R.sup.5 are aryl, the carbonate ester may be referred to as diaryl
carbonate. In particular, from the viewpoint of reactivity with the
aromatic dihydroxy compound, both R.sup.4 and R.sup.5 are
preferably aryl. The carbonate ester is more preferably a diaryl
carbonate represented by the following Formula (33).
##STR00014##
[0090] In Formula (33), R.sup.6 and R.sup.7 each independently
represent a halogen atom, nitro, cyano, C.sub.1-C.sub.20 alkyl,
C.sub.1-C.sub.20 alkoxycarbonyl, C.sub.4-C.sub.20 cycloalkyl, or
C.sub.6-C.sub.20 aryl, and p and q each independently represent an
integer of 0 to 5.
[0091] Specific examples of such a carbonate ester include dialkyl
carbonates such as dimethyl carbonate, diethyl carbonate, and
di-t-butyl carbonate; and (substituted) diaryl carbonates such as
diphenyl carbonate, bis(4-methylphenyl)carbonate,
bis(4-chlorophenyl)carbonate, bis(4-fluorophenyl)carbonate,
bis(2-chlorophenyl)carbonate, bis(2,4-difluorophenyl)carbonate,
bis(4-nitrophenyl)carbonate, bis(2-nitrophenyl)carbonate,
bis(methylsalicylphenyl)carbonate, and ditolyl carbonate. Among
these, diphenyl carbonate is preferred. These carbonate esters may
be used individually, or two or more of these may be used as a
mixture.
[0092] Preferably not more than 50 mol %, more preferably not more
than 30 mol % of the carbonate ester may be substituted with a
dicarboxylic acid(s) and/or dicarboxylic acid ester(s).
Representative examples of the dicarboxylic acid(s) and/or
dicarboxylic acid ester(s) include terephthalic acid, isophthalic
acid, diphenyl terephthalate, and diphenyl isophthalate. In cases
of substitution with such a dicarboxylic acid(s) and/or
dicarboxylic acid ester(s), a polyester carbonate is obtained.
[0093] The method for producing the aromatic polycarbonate
copolymer (B) is the same as the method described above as an
example of the production method for the aromatic polycarbonate
resin (A).
[Polyalkylene Glycol or Fatty Acid Ester Thereof (C)]
[0094] The polycarbonate resin composition for a thin optical
component of the present invention preferably contains a
polyalkylene glycol or a fatty acid ester thereof (C). By the
inclusion of such a polyalkylene glycol or a fatty acid ester
thereof (C), the transmittance, hue, and brightness of the
polycarbonate resin composition for a thin optical component of the
present invention can be increased.
[0095] Examples of the polyalkylene glycol include homopolymers and
copolymers of alkylene glycols, and derivatives thereof. Specific
examples of the polyalkylene glycol include C.sub.2-C.sub.6
polyalkylene glycols such as polyethylene glycol, polypropylene
glycol, and polytetramethylene glycol; random or block copolymers
of polyoxyethylene-polyoxypropylene; and copolymers such as
glyceryl ethers of polyoxyethylene-polyoxypropylene, and monobutyl
ethers of polyoxyethylene-polyoxypropylene. More preferred examples
of the polyalkylene glycol include polymers containing an
oxyethylene unit, for example, polyethylene glycol, polypropylene
glycol, poly(2-methyl)ethylene ether glycol, polytetramethylene
ether glycol, polypropylene ether glycol, polytrimethylene ether
glycol, polytetramethylene ether glycol, polypentamethylene ether
glycol, polyhexamethylene ether glycol, and
polyoxyethylene-polyoxypropylene copolymers, and derivatives
thereof.
[0096] The number average molecular weight of the polyalkylene
glycol is usually 500 to 500,000, preferably 1000 to 100,000, more
preferably 1000 to 50,000.
[0097] The number average molecular weight of the polyalkylene
glycol copolymer is the number average molecular weight calculated
based on the hydroxyl value measured according to JIS K1577.
[0098] As the fatty acid ester of the polyalkylene glycol fatty
acid ester, either a linear or branched fatty acid ester may be
used. The fatty acid constituting the fatty acid ester may be
either a saturated fatty acid or an unsaturated fatty acid. Fatty
acid esters in which a part of the hydrogen atoms are substituted
with a substituent(s) such as hydroxyl may also be used.
[0099] Examples of the fatty acid constituting the fatty acid ester
include monovalent or divalent fatty acids having a carbon number
of not less than 10, for example, monovalent saturated fatty acids
such as capric acid, lauric acid, tridecylic acid, myristic acid,
pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid,
nonadecanoic acid, arachic acid, behenic acid, lignoceric acid,
cerotic acid, heptacosanoic acid, montanic acid, melissic acid, and
lacceric acid; monovalent unsaturated fatty acids having a carbon
number of not less than 10 such as unsaturated fatty acids
including oleic acid, elaidic acid, linoleic acid, linolenic acid,
arachidonic acid, cetoleic acid, and erucic acid; and divalent
fatty acids having a carbon number of not less than 10 such as
sebacic acid, undecanedioic acid, dodecanedioic acid,
tetradecanedioic acid, thapsic acid and decenedioic acid,
undecenedioic acid, and dodecenedioic acid. These fatty acids may
be used individually, or as a combination of two or more thereof.
Examples of the fatty acid also include fatty acids having one or
more hydroxyl groups in the molecule.
[0100] Preferred specific examples of the polyalkylene glycol fatty
acid ester include polyethylene glycol monopalmitate, polyethylene
glycol dipalmitate, polyethylene glycol monostearate, polyethylene
glycol distearate, polyethylene glycol
(monopalmitate-monostearate), polypropylene glycol monopalmitate,
polypropylene glycol dipalmitate, polypropylene glycol
monostearate, polypropylene glycol distearate, and polypropylene
glycol (monopalmitate-monostearate).
[0101] The content of the polyalkylene glycol or a fatty acid ester
thereof (C) is preferably 0.01 to 1 part by mass with respect to a
total of 100 parts by mass of the aromatic polycarbonate resin (A)
and the aromatic polycarbonate copolymer (B). The content is more
preferably not less than 0.02 part by mass, still more preferably
not less than 0.03 part by mass, and more preferably not more than
0.9 part by mass, still more preferably not more than 0.8 part by
mass, still more preferably not more than 0.7 part by mass,
especially preferably not more than 0.6 part by mass. In cases
where the content is less than 0.01 part by mass, improvement of
the hue and suppression of yellowing are likely to be insufficient,
while in cases where the content exceeds 1 part by mass, yellowing
and a decrease in the light transmittance are likely to occur.
[Heat Stabilizer (D)]
[0102] The polycarbonate resin composition for a thin optical
component of the present invention preferably contains a heat
stabilizer (D). By the inclusion of such a heat stabilizer, the hue
and the thermal stability of the polycarbonate resin composition
for a thin optical component of the present invention can be
increased.
[0103] The heat stabilizer (D) used in the polycarbonate resin
composition for a thin optical component of the present invention
is not limited as long as it is a known heat stabilizer, and
examples of the heat stabilizer include phosphorus-based heat
stabilizers, sulfur-based heat stabilizers, and hindered phenol
antioxidants. Among these, phosphorus-based heat stabilizers and
hindered phenol antioxidants are preferred since these are likely
to allow production of a polycarbonate resin composition for a thin
optical component having an excellent hue and residence heat
stability. In particular, phosphorus-based heat stabilizers are
effective for improvement of the initial hue, and hindered phenol
antioxidants are effective for suppressing deterioration of the
color tone and a decrease in the molecular weight during molding at
high temperature. In particular, combined use of a phosphorus-based
heat stabilizer(s) and a hindered phenol antioxidant(s) is
preferred since, by this, an excellent hue and residence heat
stability can be achieved, and deterioration of the color tone and
a decrease in the molecular weight during molding at high
temperature can be suppressed.
[0104] Examples of the phosphorus-based heat stabilizer used in the
present invention include phosphorous acid, phosphoric acid,
phosphorous acid esters, and phosphoric acid esters. Phosphorous
acid esters such as phosphite and phosphonite are preferred.
[0105] In the present invention, preferred examples of the
phosphorus-based heat stabilizer include phosphorous acid esters
represented by the following Formula (34).
##STR00015##
[0106] In Formula (34), R.sup.8 represents aryl or alkyl, and these
may be either the same or different.
[0107] In cases where R.sup.8 is aryl, R.sup.8 is preferably aryl
represented by the following Formula (35), Formula (36), or Formula
(37).
##STR00016##
[0108] In the Formulae (35) and (36), R.sup.9 and R.sup.10 each
independently represent C.sub.1-C.sub.10 alkyl.
##STR00017##
[0109] Examples of such a phosphorous acid ester include
bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite,
bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphite,
and bis(2,4-dicumylphenyl)pentaerythritol diphosphite. Specific
examples of the phosphorous acid ester include commercially
available products such as "Adekastab PEP-24G" and "Adekastab
PEP-36", manufactured by ADEKA Corporation; and "Doverphos S-9228",
manufactured by Dover Chemical Corporation.
[0110] In the Formula (34), the alkyl group of R.sup.8 is
preferably C.sub.1-C.sub.30 alkyl. Specific examples of the
phosphorous acid ester include distearyl pentaerythritol
diphosphite and dinonyl pentaerythritol diphosphite. Distearyl
pentaerythritol diphosphite is especially preferred.
[0111] In the present invention, other preferred examples of the
phosphorus-based heat stabilizer include phosphorous acid esters
represented by the following General Formula (38).
##STR00018##
[0112] In the Formula (38), each of R.sup.11 to R.sup.15 represents
a hydrogen atom, aryl, or C.sub.1-C.sub.20 alkyl, and these may be
either the same or different.
[0113] In the Formula (38), examples of the aryl or the alkyl in
R.sup.11 to R.sup.15 include phenyl, methyl, ethyl, propyl,
n-propyl, n-butyl, and tert-butyl.
Tris(2,4-di-tert-butylphenyl)phosphite, in which R.sup.11 and
R.sup.13 are tert-butyl, and R.sup.12, R.sup.14, and R.sup.15 are
hydrogen atoms, is preferred, and this is commercially available
from ADEKA Corporation under the trade name "Adekastab 2112".
[Phenolic Antioxidant]
[0114] Examples of the phenolic antioxidant include hindered phenol
antioxidants. Specific examples of the hindered phenol antioxidants
include pentaerythritol
tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],
octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate,
thiodiethylene
bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate],
N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)-
, 2,4-dimethyl-6-(1-methylpentadecyl)phenol,
diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate,
3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p--
cresol, 4,6-bis(octylthiomethyl)-o-cresol,
ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate]-
, hexamethylene
bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and
1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,-
5H)-trione,2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino-
)phenol.
[0115] Among these, pentaerythritol
tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and
octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are
preferred. Specific examples of such phenolic antioxidants include
"Irganox 1010" and "Irganox 1076", manufactured by BASF; and
"Adekastab AO-50" and "Adekastab AO-60", manufactured by ADEKA
Corporation.
[0116] The polycarbonate resin composition for a thin optical
component of the present invention may contain one kind of heat
stabilizer (D) or a mixture of two or more kinds of heat
stabilizers (D). Normally, the content of the heat stabilizer(s)
(D) is preferably 0.005 to 0.5 part by mass with respect to a total
of 100 parts by mass of the aromatic polycarbonate resin (A) and
the aromatic polycarbonate copolymer (B). In cases where the
content of the heat stabilizer (D) is less than the lower limit,
the hue and the thermal stability-improving effect of the
polycarbonate resin composition for a thin optical component of the
present invention are likely to be insufficient, while in cases
where the content is more than the upper limit, the effect tends to
reach the plateau, and production of gas often occurs during
molding to cause mold contamination, which is not preferred. From
such a point of view, the content of the thermal stabilizer (D) is
more preferably not less than 0.01 part by mass, still more
preferably not less than 0.02 part by mass, especially preferably
not less than 0.05 part by mass. Further, the content is more
preferably not more than 0.3 part by mass, still more preferably
not more than 0.2 part by mass, especially preferably not more than
0.1 part by mass.
[Epoxy Compound (E)]
[0117] In the present invention, as an epoxy compound (E), a
compound having one or more epoxy groups in the molecule may be
used. Preferred specific examples of the compound include phenyl
glycidyl ether, allyl glycidyl ether, t-butylphenyl glycidyl ether,
3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl carboxylate,
3,4-epoxy-6-methylcyclohexylmethyl-3',4'-epoxy-6'-methylcyclohexyl
carboxylate, 2,3-epoxycyclohexylmethyl-3',4'-epoxycyclohexyl
carboxylate,
4-(3,4-epoxy-5-methylcyclohexyl)butyl-3',4'-epoxycyclohexyl
carboxylate, 3,4-epoxycyclohexylethylene oxide, cyclohexylmethyl
3,4-epoxycyclohexyl carboxylate,
3,4-epoxy-6-methylcyclohexylmethyl-6'-methylcyclohexyl carboxylate,
bisphenol-A diglycidyl ether, tetrabromobisphenol-A glycidyl ether,
diglycidyl ester of phthalic acid, diglycidyl ester of
hexahydrophthalic acid, bis-epoxydicyclopentadienyl ether,
bis-epoxyethylene glycol, bis-epoxycyclohexyl adipate, butadiene
diepoxide, tetraphenylethylene epoxide, octylepoxy phtallate,
epoxidized polybutadiene, 3,4-dimethyl-1,2-epoxycyclohexane,
3,5-dimethyl-1,2-epoxycyclohexane,
3-methyl-5-t-butyl-1,2-epoxycyclohexane,
octadecyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate,
N-butyl-2,2-dimethyl-3,4-epoxycyclohexyl carboxylate,
cyclohexyl-2-methyl-3,4-epoxycyclohexyl carboxylate,
N-butyl-2-isopropyl-3,4-epoxy-5-methylcyclohexyl carboxylate,
octadecyl-3,4-epoxycyclohexyl carboxylate,
2-ethylhexyl-3',4'-epoxycyclohexyl carboxylate,
4,6-dimethyl-2,3-epoxycyclohexyl-3',4'-epoxycyclohexyl carboxylate,
4,5-epoxytetrahydrophthalic acid anhydride,
3-t-butyl-4,5-epoxytetrahydrophthalic acid anhydride, diethyl
4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate,
di-n-butyl-3-t-butyl-4,5-epoxy-cis-1,2-cyclohexyl dicarboxylate,
epoxidized soy bean oil, and epoxidized linseed oil.
[0118] The epoxy compounds may be used individually, or two or more
of the epoxy compounds may be used in combination.
[0119] The content of the epoxy compound (E) is 0.0005 to 0.2 part
by mass, preferably not less than 0.001 part by mass, more
preferably not less than 0.003 part by mass, still more preferably
not less than 0.005 part by mass, and preferably not more than 0.15
part by mass, more preferably not more than 0.1 part by mass, still
more preferably not more than 0.05 part by mass, with respect to a
total of 100 parts by mass of the aromatic polycarbonate resin (A)
and the aromatic polycarbonate copolymer (B). In cases where the
content of the epoxy compound (E) is less than 0.0005 part by mass,
the hue and the heat discoloration resistance are insufficient,
while in cases where the content is more than 0.2 part by mass, the
heat discoloration resistance is even worse, and the hue and the
moist heat stability are also low.
[Ratio Between Contents of Phosphorus-Based Heat Stabilizer (D) and
Epoxy Compound (E)]
[0120] In cases where the phosphorus-based heat stabilizer (D) and
the epoxy compound (E) are used in combination in the polycarbonate
resin composition of the present invention, the ratio between the
contents of the phosphorus-based heat stabilizer (D) and the epoxy
compound (E) is preferably within the range of 0.5 to 10 in terms
of the mass ratio of (D)/(E). In cases where the mass ratio of
(D)/(E) is below 0.5, the hue, especially the initial YI value, is
poor, while in cases where the mass ratio exceeds 10, the heat
discoloration resistance is poor. The mass ratio of (D)/(E) is
preferably not less than 0.7, more preferably not less than 0.8,
and preferably not more than 8, more preferably not more than 7,
still more preferably not more than 6.
[Other Additives]
[0121] The polycarbonate resin composition for a thin optical
component of the present invention may further contain various
additives as long as the effect of the present invention is not
deteriorated. Examples of such additives include flame retardants,
mold release agents, ultraviolet absorbers, dyes and pigments,
fluorescent brightening agents, anti-drip agents, antistatic
agents, anti-clouding agents, lubricants, anti-blocking agents,
dispersants, and antimicrobial agents.
[Melt Viscosity of Polycarbonate Resin Composition for Thin Optical
Component]
[0122] The melt viscosity of the polycarbonate resin composition
for a thin optical component of the present invention is not
limited, and may be appropriately selected depending on the shape
of the molded article of interest. For molding of the
later-described thin optical component, the flow value (Q value) as
measured using a Koka flow tester according to Appendix C of JIS
(1999) K7210 at 240.degree. C. at 160 kgf/cm.sup.2 is usually
preferably not less than 6 (unit: 10.sup.-2 cm.sup.3/sec.), more
preferably not less than 10, still more preferably not less than
17, especially preferably not less than 20, most preferably not
less than 25. The Q value is an index of the melt viscosity. A
higher Q value indicates a lower viscosity and a better fluidity.
On the other hand, the upper limit of the Q value is not limited as
long as the excellent physical properties of the polycarbonate
resin composition for a thin optical component of the present
invention are not deteriorated. The Q value is usually not more
than 100, preferably not more than 90, more preferably not more
than 80, still more preferably not more than 70, especially
preferably not more than 60.
[Method for Producing Polycarbonate Resin Composition for Thin
Optical Component]
[0123] The method for producing the polycarbonate resin composition
for a thin optical component of the present invention is not
limited, and known methods for producing polycarbonate resin
compositions may be widely employed. Examples of such methods
include methods in which the aromatic polycarbonate resin (A), the
aromatic polycarbonate copolymer (B), and other components to be
blended as required, are preliminarily mixed together using a mixer
such as a tumbler or Henschel mixer, and then the resulting mixture
is melt-kneaded in a mixer such as a Banbury mixer, roll,
Brabender, single-screw kneading extruder, twin-screw kneading
extruder, kneader, or the like. The temperature during the melt
kneading is usually within the range of 210 to 320.degree. C.,
preferably 220 to 280.degree. C., most preferably 225 to
260.degree. C. In cases where the melt kneading temperature is too
low, the mixture is exposed to significant shear during kneading,
resulting in a local increase in the temperature. This may lead to
deterioration of the color tone and occurrence of resin burning,
which is not preferred. In cases where the melt kneading
temperature is too high, the resin tends to suffer from yellowing,
and may have a poor color tone, which is not preferred.
[Thin Optical Component]
[0124] The polycarbonate resin composition for a thin optical
component of the present invention can be used for production of a
thin optical component by pelletizing the polycarbonate resin
composition and molding the resulting pellets by various molding
methods. The composition is especially preferably used for molding
of a thin optical component by injection molding. The resin
temperature during the injection molding is usually 260 to
380.degree. C. In particular, the molding is preferably carried out
at a resin temperature higher than 260 to 300.degree. C., that is,
higher than the temperatures generally applied to injection molding
of a polycarbonate resin. The resin temperature is preferably 305
to 380.degree. C., more preferably 310 to 375.degree. C., still
more preferably 315 to 370.degree. C., especially preferably 320 to
365.degree. C. When a conventional polycarbonate resin composition
is used, there is a problem in that, in cases where the resin
temperature during molding is increased for molding of a thin
molded article, white spots of foreign substances are likely to
appear on the surface of the molded article. In contrast, when a
polycarbonate resin composition for a thin optical component of the
present invention is used, a thin molded article having a good
appearance can be produced even within such a temperature
range.
[0125] When direct measurement of the resin temperature is
difficult, the temperature set for the barrel is understood as the
resin temperature.
[0126] The thin molded article in the present invention means a
molded article having a plate-like portion with a thickness of
usually not more than 1 mm, preferably not more than 0.8 mm, more
preferably not more than 0.6 mm. The plate-like portion may be
either a flat plate or a bent plate, and may have either a flat
surface or an irregular surface. A cross-section of the plate-like
portion may have an inclined plane, or may be a wedge-shaped
cross-section or the like.
[0127] Examples of the thin optical component include components of
devices/appliances that directly or indirectly use light sources
such as LEDs, organic EL, incandescent lamps, fluorescent lamps,
and cathode lamps. Representative examples of such components
include light guide plates and members for surface emitters.
[0128] A light guide plate is used for guiding light from a light
source such as an LED in a liquid crystal backlight unit, or in a
display device or an illuminating device. A light guide plate
allows light to enter from its lateral side or back side, and
usually diffuses the light through irregularities provided on its
surface to cause emission of uniform light. It usually has a
flat-plate shape, and may or may not have irregularities on its
surface.
[0129] Light guide plates are usually preferably molded by
injection molding, ultra-high-speed injection molding, injection
compression molding, or the like.
[0130] The light guide plate by the polycarbonate resin composition
for a thin optical component of the present invention can be
favorably used in the fields of liquid crystal backlight units, and
various display devices and illuminating devices. Examples of such
devices include mobile terminals such as mobile phones, mobile
notebooks, netbooks, slate PCs, tablet PCs, smartphones, and tablet
terminals; cameras; watches/clocks; notebook PCs; displays; and
illuminating devices.
EXAMPLES
[0131] The present invention is described below more concretely by
way of Examples. However, the present invention should not be
interpreted as being limited to the following Examples.
[0132] The materials used in the following Examples and Comparative
Examples are shown below in Table 1.
[0133] An aromatic polycarbonate copolymer (B) was produced
according to the following Production Example.
Production Example of Aromatic Polycarbonate Copolymer (B)
[0134] A raw material mixture was prepared by mixing 40 parts by
mass of 1,1-bis(4-hydroxyphenyl)dodecane, 60 parts by mass of
2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 107 parts by mass of
diphenyl carbonate, and, as a catalyst, 2 wt % aqueous cesium
carbonate solution such that cesium carbonate was contained at 0.5
.mu.mol per 1 mol of total dihydroxy compounds. The resulting
mixture was fed to a first reactor equipped with a stirrer, heating
medium jacket, vacuum pump, and reflux condenser. After replacing
the atmosphere with nitrogen, a heating medium at a temperature of
230.degree. C. was passed through the heating medium jacket to
allow a slow increase in the internal temperature of the first
reactor, thereby dissolving the mixture. Thereafter, while rotating
the stirrer at 300 rpm and keeping the internal temperature of the
first reactor at 220.degree. C., the pressure in the first reactor,
in terms of the absolute pressure, was reduced from 101.3 kPa (760
Torr) to 13.3 kPa (100 Torr) for 40 minutes, during which phenol
produced as a by-product of oligomerization reaction of the
aromatic dihydroxy compounds and diphenyl carbonate was removed by
distillation.
[0135] Subsequently, while keeping the pressure in the first
reactor at 13.3 kPa and further removing phenol by distillation,
transesterification reaction was carried out for 80 minutes. After
restoring the pressure with nitrogen, the oligomer in the first
reactor was transferred into a second reactor at an internal
temperature of 240.degree. C. equipped with a stirrer, heating
medium jacket, vacuum pump, and reflux condenser. While stirring
the oligomer at 38 rpm, the internal temperature was increased
using the heating medium jacket. The pressure in the second
reactor, in terms of the absolute pressure, was reduced from 101.3
kPa to 13.3 kPa for 40 minutes. Thereafter, the temperature was
kept increased, and the internal pressure, in terms of the absolute
pressure, was reduced from 13.3 kPa to 399 Pa (3 Torr) for 40
minutes while removing distilled phenol to the outside of the
system. The temperature was further kept increased, and when the
absolute pressure in the second reactor reached 70 Pa (about 0.5
Torr), the pressure of 70 Pa was maintained to perform
polycondensation reaction. The final internal temperature of the
second reactor was 255.degree. C. When the stirring power of the
stirrer in the second reactor reached a predetermined value, the
polycondensation reaction was stopped. After restoring the pressure
in the rector with nitrogen, pressure was applied to allow
extraction from the bottom of the tank. By cooling in a
water-cooling tank, an aromatic polycarbonate copolymer was
obtained. Thereafter, butyl paratoluenesulfonate was mixed at 5 ppm
with the obtained aromatic polycarbonate copolymer, and the
resulting mixture was melt-kneaded in a 30-mm diameter twin-screw
extruder at 240.degree. C. to form a strand-shaped product,
followed by cutting it with a pelletizer to obtain a pellet-shaped
aromatic polycarbonate copolymer.
[0136] In the obtained aromatic polycarbonate copolymer, the ratio
of the carbonate structure (i) derived from the Formula (19) to the
total carbonate structural units was 30 mol %, and the viscosity
average molecular weight (Mv) was 15,000.
TABLE-US-00001 TABLE 1 Component Code Aromatic A1 An aromatic
polycarbonate resin produced by polycarbonate interfacial
polymerization using bisphenol A resin (A) as a starting material.
Viscosity average molecular weight (Mv): 14,000 A2 An aromatic
polycarbonate resin produced by interfacial polymerization using
bisphenol A as a starting material. Viscosity average molecular
weight (Mv): 12,500 Aromatic B An aromatic polycarbonate copolymer
composed polycarbonate of the structural units of Formula (19) and
copolymer (B) Formula (26). The ratio of the carbonate structural
unit (i) derived from Formula (19) in the total carbonate
structural units: 30 mol % Viscosity average molecular weight (Mv):
15,000 Polyalkylene C1 A poly(2-methyl)ethylene ether glycol glycol
represented by HO(CH(CH.sub.3)CH.sub.2O)nH, n = 17 Manufactured by
NOF Corporation; trade name, "Uniol D-2000" Number average
molecular weight: 2000 Polyalkylene C2 A polytetramethylene ether
glycol represented glycol by
HO(CH.sub.2CH.sub.2CH.sub.2CH.sub.2O)nH, n = 21 Manufactured by
Mitsubishi Chemical Corporation; trade name, "PTMG 1500" Number
average molecular weight: 1500 Heat D1 Bis(2,6-di-tert-butyl-4-
stabilizer methylphenyl)pentaerythritol diphosphite Manufactured by
ADEKA Corporation; trade name, "Adekastab PEP-36" Heat D2
Octadecyl-3-(3,5-di-tert-butyl-4- stabilizer
hydroxyphenyl)propionate Manufactured by BASF; trade name, "Irganox
1076" Heat D3 Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-
stabilizer 4-hydroxyphenyl)propionate] Manufactured by BASF; trade
name, "Irganox 1010" Epoxy E 3,4-Epoxycyclohexylmethyl-3',4'-
compound epoxycyclohexyl carboxylate Manufactured by Daicel
Corporation; trade name, "Celloxide 2021P"
Examples 1 to 4, Comparative Examples 1 to 3
[Production of Resin Composition Pellets]
[0137] Each component shown in Table 1 was blended at the ratio
(part by mass) described in Table 2, and the resulting mixture was
mixed in a tumbler for 20 minutes. Thereafter, the mixture was
melt-kneaded in a twin-screw extruder having a screw diameter of 22
mm with a vent ("TEM26SX", manufactured by Toshiba Machine Co.,
Ltd.) at a cylinder temperature of 240.degree. C. and a screw speed
of 180 rpm, and pellets were obtained by strand cutting.
[Flow Value: Q Value]
[0138] For the obtained resin composition pellets, the flow value
(Q value; unit, cc/sec.) was measured using a CFT-500D type flow
tester manufactured by Shimadzu Corporation and an orifice of 1-mm
diameter.times.10 mm according to Appendix C of JIS (1999) K7210 at
240.degree. C. at 160 kgf/cm.sup.2 with a preheating time of 7
minutes.
[0139] Table 2 shows the values obtained. A higher flow value (Q
value) indicates a higher fluidity and better moldability, while a
lower flow value (Q value) indicates a lower fluidity and poorer
moldability.
[Charpy Notched Impact Strength]
[0140] Injection molding was carried out using an injection molding
machine (J55-60H, manufactured by Japan Steel Works, Ltd.) at a
cylinder temperature of 260.degree. C. and a mold temperature of
80.degree. C. with a molding cycle of 50 seconds to mold an ISO
multi-purpose test piece (3 mm). According to ISO179, the prepared
ISO multi-purpose test piece (3-mm thickness) was subjected to
notch processing, and the Charpy notched impact strength (unit:
kJ/m.sup.2) was measured at 23.degree. C.
[Test for Cracking During Molding of Light Guide Plate]
[0141] A flat-plate-shaped light guide plate with a short side of
61 mm, a long side of 110 mm, and a thickness of 0.45 mm having a
prism on its mold-fixed side was molded by injection molding. The
prism was provided with a pattern having a 50-.mu.m pitch and a
14-.mu.m depth. The injection molding was carried out using an
injection molding machine "HSP100A" manufactured by Sodick Plustech
Co., Ltd. at a mold temperature of 40.degree. C., a cylinder
temperature of 360.degree. C., and an injection speed of 400
mm/sec. The molding was carried out for 50 shots, and the number of
cracked plates was counted.
[Light Guide Plate Bending Test]
[0142] The light guide plate obtained as described above was
subjected to a light guide plate bending test using Instron (Type
5544, manufactured by Instron), wherein the support span was 10 mm;
the test speed was 10 mm/min.; the bend direction was parallel to
the direction of the flow during molding; the molded article was
placed such that the prism pattern faced downward; and a jig having
a width of 3 mm and a point angle of 30.degree. was used. In this
test, the maximum point load (unit: N) was measured. A higher
maximum point load indicates a higher strength, which means that
cracking is less likely to occur.
[0143] The evaluation results are shown below in Table 2.
[Hue (YI Value)]
[0144] The obtained pellets were dried using a hot air circulation
dryer at 100.degree. C. for 5 to 7 hours, and then molded into a
long-optical-path molded article (300 mm.times.7 mm.times.4 mm)
using an injection molding machine ("EC100SX-2A", manufactured by
Toshiba Machine Co., Ltd.) at a resin temperature of 360.degree. C.
and a mold temperature of 80.degree. C.
[0145] This long-optical-path molded article was subjected to
measurement of the YI value (the degree of yellowing) at an optical
path length of 300 mm. The measurement was carried out using a Long
Pathlength Transmission Spectrophotometer ("ASA 1", manufactured by
Nippon Denshoku Industries Co., Ltd.; C light source; viewing
angle, 2.degree.).
[0146] The evaluation results are shown below in Table 2.
TABLE-US-00002 TABLE 2 Comparative Comparative Comparative
Component Code Example 1 Example 2 Example 3 Example 4 Example 5
Example 6 Example 7 Example 1 Example 2 Example 3 Aromatic A1 74 82
84 91 84 84 84 71 76 100 polycarbonate A2 26 18 16 9 16 16 16 29 24
0 resin (A) Aromatic B 34.3 22.1 18.5 9.8 25.0 25.0 25.0 0 0 0
polycarbonate copolymer (B) Polyalkylene C1 0.1 0.3 0.4 0.5 0.4 0.4
0.3 0.3 0.3 glycol Polyalkylene C2 1.0 glycol Heat stabilizer D1
0.04 0.04 0.05 0.05 0.06 0.06 0.03 0.03 0.03 0.03 Heat stabilizer
D2 0.13 Heat stabilizer D3 0.13 Epoxy E 0.04 compound Evaluation
results Flow value (Q value) 29 28 28 28 29 29 30 28 26.5 17.6
(0.01 cc/sec.) Charpy impact 2.0 2.3 4.6 5.2 7.3 7.4 6.8 0.9 1.1
7.5 strength (kJ/m.sup.2) Cracking during -- -- 1/50 -- -- -- --
35/50 30/50 0/50 molding of light guide plate (number of cracked
plates/number of molding shots) Light guide plate -- -- 1218 -- --
-- -- 1075 1094 1241 bending test maximum point load (N) YI value
-- -- 27 26 25 25 21 23 23 23
[0147] As is evident from Table 2, Examples 1 to 4, each of which
contains the aromatic polycarbonate copolymer (B) in the present
invention, have improved impact strength compared to Comparative
Example 1, which does not contain the aromatic polycarbonate
copolymer (B), when the fluidity was adjusted to similar
levels.
[0148] Among these, Example 3, which contains the aromatic
polycarbonate copolymer (B) in the present invention, exhibited a
better balance between the fluidity and the impact resistance
compared to Comparative Examples 2 and 3, which do not contain the
aromatic polycarbonate copolymer (B). In particular, it can be seen
that, in comparison with Comparative Example 2, Example 3 shows a
much lower level of cracking in molding of the light guide
plate.
[0149] Thus, the polycarbonate resin composition for a thin optical
component of the present invention, containing both the aromatic
polycarbonate resin (A) and the aromatic polycarbonate copolymer
(B), has an excellent balance between the fluidity and the impact
resistance, and exhibits sufficient strength even in cases where it
is formed into a thin optical component such as a light guide
plate. It is therefore clear that the composition can be suitably
used for such a component.
INDUSTRIAL APPLICABILITY
[0150] By the polycarbonate resin composition for a thin optical
component of the present invention, the strength of a molded
article after molding can be increased while fluidity sufficient
for molding of a thin optical member can be maintained. Therefore,
cracking, which may occur in a thin optical member, can be
remarkably reduced. Thus, the composition can be extremely
favorably used for thin optical components, and its industrial
applicability is very high.
[0151] While the invention has been described in detail and with
reference to specific embodiments thereof, it will be apparent to
one skilled in the art that various changes and modifications can
be made therein without departing from the spirit and scope
thereof.
* * * * *