JP3187142B2 - High refractive index, low birefringence polycarbonate resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polycarbonate resin having improved refractive index and birefringence. More particularly, the high refractive index having a specific amount of 9,9-bis (4-oxy-phenylene) fluorene configuration units relates polycarbonate resin having excellent and transparency at low birefringence. Such a resin takes advantage of its characteristics, such as a CD pickup lens,
It is extremely useful as a material for optical lenses such as Fresnel lenses, projection television screens, films such as retardation films, and discs.

[0002]

2. Description of the Related Art Conventionally, polycarbonate resins obtained by reacting a carbonate precursor with 2,2-bis (4-hydroxyphenyl) propane have excellent transparency, heat resistance, mechanical properties and dimensional stability. Therefore, it is widely used in many fields as engineering plastic. In particular, it has many uses as an optical material because of its excellent transparency. However, such a polycarbonate resin has a disadvantage that birefringence is large as an optical material.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polycarbonate resin having a high refractive index and a low birefringence without impairing the transparency of the polycarbonate resin.

[0004] The present inventors have conducted intensive result of extensive investigations, 9,9-bis (4-oxy-phenylene) identifying fluorene configuration unit ratio introduced polycarbonate copolymer to achieve the above object this object as attained plugs Heading to do
The present invention has been reached.

[0005] 9,9-bis (4-hydroxyphenyl)
Aromatic polycarbonate resins obtained by reacting fluorene with a carbonate precursor are known, and it is also known that this polymer has a high refractive index and good heat resistance. However, when synthesizing this homopolymer, a large amount of a gel-like substance insoluble in a solvent was generated, and the yield of the solvent-soluble component was at most 60 to 70%, which was not practical. Also,
When this was to be melt molded, there was a problem that the melt viscosity was too high to be molded.

[0006] However, 9,9-bis (4-oxy-phenylene) amount identify fluorene configuration units copolymerized with the aromatic polycarbonate resin is not only does not have this disadvantage, a low birefringence at a high refractive index Is surprising.

[0007]

The present invention provides a compound represented by the following general formula [1]:

[0008]

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Wherein R _{1 to} R ₄ are a hydrogen atom, a halogen atom, a phenyl group, an alkyl group having 1 to 3 carbon atoms,
They may be the same or different. And the following general formula [2]:

[0010]

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Wherein W is a single bond, an alkylidene group, a cycloalkylidene group, a phenyl-substituted alkylidene group, a sulfone group, a sulfide group or an oxide group, and R ₅ and R ₆ are a hydrogen atom, a halogen atom, a phenyl group, It is an alkyl group having 1 to 3 carbon atoms, which may be the same or different, and m and n are each an integer of 1 to 4. Consists of structural units represented by in], the configuration unit represented by the general formula [1] containing 41 to 95 mol%, photoelastic constant 50 × 10
^-13 cm ² / dyne or less and 0.7 g was dissolved in 100 ml of methylene chloride, and the specific viscosity measured at 20 ° C. was 0.1.
9 above der is, a terminating agent of the monohydric phenol full divalent off
A high-refractive-index, low-birefringent polycarbonate resin used in an amount of 0.01 to 10 mol% based on the phenol.

The polycarbonate resins of interest in the present invention are prepared by reacting 9,9-bis (4-hydroxyphenyl) fluorenes with one or more other dihydric phenolic compounds, a terminator and a carbonate precursor material. Manufactured. It is usually produced by an interfacial polycondensation method using phosgene or a transesterification reaction using a carbonic acid diester.

9,9-bis (4-hydroxyphenyl)
As fluorenes, for example, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (3-methyl-4-hydroxyphenyl) fluorene, 9,9-bis (3-ethyl-4-hydroxyphenyl) ) Fluorene and the like, and 9,9-bis (4-hydroxyphenyl) fluorene is particularly preferred.

Other dihydric phenols include, for example, bis (4-hydroxyphenyl) methane and 2,2-bis (4
-Hydroxyphenyl) propane [commonly known as bisphenol A], 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxy −3,5
-Dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, bis (4-hydroxyphenyl) oxide, bis (3,5
-Dichloro-4-hydroxyphenyl) oxide,
4,4'-dihydroxydiphenyl, 3,3'-dichloro-4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (4 -Hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide and the like, and bisphenol A is particularly preferred. As a terminal stopper, for example, a monohydric phenol such as p-tert-butylphenol is used.
The amount used is usually 0.01 to the dihydric phenol used.
10 to 10 mol%, preferably 0.03 to 8 mol%.

In the interfacial polycondensation reaction using phosgene,
Usually, 9,9-bis (4-hydroxyphenyl) fluorenes and other dihydric phenols are dissolved in an aqueous solution of an acid binder and reacted in the presence of an organic solvent. As the acid binder, for example, a hydroxide of an alkali metal such as sodium hydroxide or potassium hydroxide is used, and as the organic solvent, for example, a halogenated hydrocarbon such as methylene chloride or chlorobenzene is used. The reaction is usually carried out at 0 to 40 ° C, preferably at 20 ° C.
It is completed in about 30 minutes at about 30 ° C. It is preferable to keep the pH of the reaction system at 10 or more as the reaction proceeds. Further, a catalyst may be used to promote the reaction. Examples of the catalyst include triethylamine and tetra-n.
Tertiary amines such as -butylammonium bromide and tetra-n-butylphosphonium bromide, quaternary ammonium compounds, quaternary phosphonium compounds and the like. Further, if necessary, an antioxidant such as hydrosulfite can be added.

In a transesterification reaction using a carbonic acid diester, 9,9-bis (4-hydroxyphenyl) fluorenes and other dihydric phenol compounds are produced by stirring with a carbonic acid diester while heating under an inert gas atmosphere. It is carried out by distilling alcohol or phenol.
The reaction temperature varies depending on the boiling point of the alcohol or phenol to be formed, but is usually in the range of 120 to 350 ° C.
In the latter half of the reaction, the system is depressurized to facilitate the distillation of the alcohol or phenol produced, thereby completing the reaction. Examples of the carbonic acid diester include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate and the like. Of these, diphenyl carbonate is particularly preferred.

A polymerization catalyst may be used to increase the polymerization rate. Examples of the polymerization catalyst include hydroxides of alkali metals and alkaline earth metals such as sodium hydroxide and potassium hydroxide, and hydroxides of boron and aluminum. Alkali metal salts, alkaline earth metal salts, quaternary ammonium salts, alkoxides of alkali metals and alkaline earth metals, organic acid salts of alkali metals and alkaline earth metals,
Zinc compounds, boron compounds, silicon compounds, germanium compounds, organotin compounds, lead compounds, antimony compounds, manganese compounds, titanium compounds,
Catalysts usually used for esterification reactions and transesterification reactions of zirconium compounds and the like can be used.
The catalyst may be used alone or in combination of two or more. These catalysts are used in an amount of 0.0001 to 1% by weight, preferably 0.000% by weight, based on the starting dihydric phenol.
It is selected in the range of 5 to 0.5% by weight.

The molecular weight of the polycarbonate resin is 0.19 or more, preferably 0.26 to less, expressed as a specific viscosity measured at 20 ° C. in a methylene chloride solution having a concentration of 0.7 g / dl.
0.45. If it is less than 0.19, the resulting molded article is not suitable because it becomes brittle.

The polycarbonate resin of the present invention, the latter general formula [1] Configuration units and the general formula represented by [2] in the content of the configuration unit represented Whereas the former 41-95 mol% 59 ~ 5 mol%. The formula below content of configuration single <br/> position represented by [1] is 41 mol%, not only the birefringence is sufficiently low, but birefringence is significantly reduced if it exceeds 95 mol%, Transparency worsens.

If necessary, the polycarbonate resin of the present invention may contain, for example, triphenyl phosphite, tris (nonylphenyl) phosphite, distearyl pentaerythritol diphosphite, diphenyl hydrogen phosphite, irganox 1076 [stearyl-β -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like;
For example, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-
Weathering agents such as 3 ', 5'-di-tert-amylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octoxyphenyl) benzotriazole, 2-hydroxy-4-octoxybenzophenone, and the like; Additives such as a coloring agent, an antistatic agent, a release agent, and a lubricant may be added. In order to mold the polycarbonate resin of the present invention, any method such as injection molding, extrusion molding, and hot press molding is adopted. In order to increase transparency, a method of casting a film by a casting method is optimal. is there. The polycarbonate resin of the present invention obtained as described above has a high refractive index, low birefringence and excellent transparency.

[0021]

The present invention will be further described with reference to the following examples. Parts and% in Examples are parts by weight and% by weight unless otherwise specified. The specific viscosity, total light transmittance, refractive index and photoelastic coefficient were measured by the following methods.

Specific viscosity: 0.7 g of the polymer was dissolved in 100 ml of methylene chloride and measured at 20.degree. Total light transmittance: Measured by Nippon Denshoku Co., Ltd. # 80 in accordance with ASTM D-1003. Refractive index: wavelength 59 by Abago refractometer manufactured by Atago Co., Ltd.
It was measured at 25 ° C. using a 8.3 nm D line. Photoelastic coefficient (birefringence): 30mm × 10mm × 100μm
Photoelasticity measuring device P manufactured by Riken Keiki Co., Ltd.
It was measured by A-150.

[0023]

Example 1 9,9-bis (4-hydroxyphenyl)
21.5 parts of fluorene, 2.47 parts of bisphenol A,
23.8 parts of a 48.5% aqueous sodium hydroxide solution and 36 distilled water
One part was charged and dissolved in a reactor equipped with a stirrer. To this was added 162 parts of methylene chloride, the mixture was cooled to 20 ° C., and 10.0 parts of phosgene was blown in for 40 minutes. Thereafter, a solution of 0.108 parts of p-tert-butylphenol dissolved in methylene chloride was added to the reaction solution, and 2.98 parts of a 48.5% aqueous sodium hydroxide solution and 0.05% of triethylamine were added.
And stirring was continued for 2 hours to complete the reaction. After completion of the reaction, a methylene chloride solution of the lower layer polycarbonate was separated from the reaction solution, and this solution was washed with an aqueous hydrochloric acid solution and distilled water, and then methylene chloride was evaporated off to obtain a polycarbonate powder. The specific viscosity of the obtained powder was 0.850. This powder was dissolved in methylene chloride to form a film. It has a total light transmittance of 89%, a refractive index of 1.636, and a photoelastic coefficient of 24 × 1.
It was 0 ^-13 cm ² / dyne.

[0024]

Example 2 9,9-bis (4-hydroxyphenyl)
19.0 parts of fluorene and 4.1 of bisphenol A
A powder was obtained in the same manner as in Example 1 except that one part was used. The specific viscosity of this powder was 0.863. When this powder was molded and evaluated in the same manner as in Example 1, the total light transmittance was 89%, the refractive index was 1.631, and the photoelastic coefficient was 30 × 10 ⁻¹³ cm ² / dyne.

[0025]

Example 3 9,9-bis (4-hydroxyphenyl)
12.6 parts of fluorene and 8.2 of bisphenol A
A powder was obtained in the same manner as in Example 1 except that three parts were used. The specific viscosity of this powder was 0.755. When this powder was molded and evaluated in the same manner as in Example 1, the total light transmittance was 90%, the refractive index was 1.616, and the photoelastic coefficient was 48 × 10 ^-13 cm ² / dyne.

[0026]

Comparative Example 1 9,9-bis (4-hydroxyphenyl)
13. 2.53 parts of fluorene and 14 of bisphenol A.
A powder was obtained in the same manner as in Example 1 except that 8 parts were used. The specific viscosity of this powder was 1.024. When this powder was molded and evaluated in the same manner as in Example 1, the total light transmittance was 90%, the refractive index was 1.592, and the photoelastic coefficient was 74 × 10 ⁻¹³ cm ² / dyne.

[0027]

Comparative Example 2 Bisphenol A polycarbonate powder having a specific viscosity of 0.451 [Panlite manufactured by Teijin Chemicals Ltd.]
L-1250] was molded and evaluated in the same manner as in Example 1. As a result, the total light transmittance was 90%, the refractive index was 1.589, and the photoelastic coefficient was 83 × 10 ⁻¹³ cm ² / dyne.

[0028]

The polycarbonate resin of the present invention has a high refractive index, low birefringence and excellent transparency, so that an optical lens,
It is extremely useful for various optical applications requiring high refractive index, low birefringence, and transparency such as films and disks.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 64/00-64/42 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] [Claim 1] The following general formula [1] [Wherein R _{1 to} R ₄ are a hydrogen atom, a halogen atom, a phenyl group, or an alkyl group having 1 to 3 carbon atoms, which may be the same or different. And a structural unit represented by the following general formula [2]: [Wherein W is a single bond, an alkylidene group, a cycloalkylidene group, a phenyl group-substituted alkylidene group, a sulfone group, a sulfide group or an oxide group, and R ₅ and R ₆ are a hydrogen atom, a halogen atom, a phenyl group, a carbon atom of 1; To 3 alkyl groups which may be the same or different, and m and n
Is an integer of 1 to 4, respectively. Consists of structural units represented by in], the configuration unit represented by the general formula [1] containing 41 to 95 mol%, photoelastic constant 50 × 10 ^-13 cm ² / dyn
The and 0.7g in e less Ri der measured specific viscosity in dissolved 20 ° C. in methylene chloride 0.19 or more 100 ml, one
The terminating agent for the polyhydric phenol is
A high-refractive-index, low-birefringent polycarbonate resin used in an amount of 0.01 to 10 mol% .