JP3329347B2 - Optical resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical resin composition. More specifically, only one glass transition temperature measured by a differential scanning calorimeter is shown , and the absolute value of the refractive index difference is 0.0
(2) Styrene resin containing (1) a specific polycarbonate resin composition or a specific aromatic polycarbonate copolymer and (2) an α, β-unsaturated dicarboxylic anhydride or a derivative thereof as a copolymer component. The present invention relates to an optical resin composition containing:

The resin composition of the present invention is useful for various optical applications such as optical disks, optical lenses and prisms because of its excellent transparency and reduced birefringence. Further, since the two types of components (1) and (2) have close glass transition temperatures, the molding cycle at the time of injection molding can be shortened.

[0003]

2. Description of the Related Art Conventionally, it has been known that many resins are used as optical transparent resins as substitutes for glass.
For example, acrylic resin is known as an optical molding material having characteristics such as good transparency and fluidity and low birefringence (Japanese Patent Application Laid-Open No. 56-131654 and others). However, the acrylic resin has a drawback that the heat resistance is as low as about 70 ° C., the impact resistance is low, and the moisture absorption easily causes warpage due to moisture.

[0004] Polycarbonate is an excellent optical molding material because it has heat resistance, impact resistance, and low moisture absorption. However, polycarbonate has a problem in its fluidity, and has a viscosity-average molecular weight in order to reduce birefringence.
Use of 15,000 to 18,000 polycarbonate (Japanese
58-180553), and a method of melt-blending vinyl resins such as polystyrene, polymethyl methacrylate, and styrene-maleic anhydride copolymer (Japanese Patent Publication No. Sho 55-4).
143). However, the former is still insufficient in fluidity and its use is limited, and the latter is an optically non-uniform resin because the dispersion particle size is large due to incompatibility and the refractive index is greatly different. It becomes a composition. Further, in order to improve the birefringence of polycarbonate, there has been known a method in which melt blending with a vinyl resin having a matched refractive index is attempted (Japanese Patent Publication No. 1-39699, JP-A-63-122749, etc.). In this case, since the glass transition temperatures of the polycarbonate and the vinyl resin are significantly different, the resin composition has two glass transition temperatures, and there is a problem in productivity during molding.

[0005] The relationship between the productivity during molding and the glass transition temperature is as follows. Plastic lenses are lighter than glass and have the property of being able to easily mass-produce arbitrary molded products such as aspherical shapes due to their good fluidity. Attempts have been made to use the medium in high-precision optical systems by precision molding. In this ultra-precision molding, keep the mold temperature of the injection molding machine above the glass transition temperature of the resin in order to find the precision, after injecting the resin, cool it down to below the glass transition temperature and take it out of the mold such as, molding methods such as a heat cycle method and the gate seal molding method has been adopted (for example, "Nikkei mechanical 1992.11.16 / P.32~
P.44 "). In the case of the ultra-precision molding method according to these methods, in the method in which the above-mentioned melt blending of the polycarbonate and the vinyl resin having the same refractive index was tried, the polycarbonate used was a polycarbonate derived from bisphenol A, The glass transition temperatures of the polycarbonate and the vinyl resin are greatly different, and the resin composition has two glass transition temperatures. That is, a resin composition having two glass transition temperatures and having a large difference between them has a long cooling time during a molding cycle, and therefore has low productivity, and it has been desired to approach or unify the glass transition temperature. .

[0006]

As described above, in a resin composition comprising a styrene resin having polycarbonate and an α, β-unsaturated dicarboxylic anhydride or a derivative thereof as a copolymer component, the resin composition is There is a problem in formability because it has two glass transition temperatures, and therefore, it is necessary to make the two glass transition temperatures close to each other. In addition, there is also a problem that unless both refractive indices are adjusted to be as equal as possible within a considerably narrow range, they cannot be practically used as optical molding materials, and these problems can be solved simultaneously. It is essential as an optical molding material, but has not been found until now.

The resin composition of the present invention can be combined with a styrene-based resin without sacrificing the excellent transparency, heat resistance, impact resistance, and low moisture absorption of the polycarbonate itself while considering the above-mentioned problems. It is an object of the present invention to provide an optical molding material that can maintain the low birefringence achieved by the above.

[0008]

The present inventors have SUMMARY OF THE INVENTION As a result of intensive studies to solve all the problems described above, the glass transition temperature for the polycarbonate resin, the compatibility with the styrene resin, the refractive index or the like polygonal Investigations were conducted from a general viewpoint. (A) Among aromatic polycarbonate resins having bisphenol structural units, 2,2-bis (4-hydroxy-3
-Methylphenyl) propane (hereinafter referred to as bisphenol C
Polycarbonate resin having a structural unit derived from), generally has a lower glass transition temperature and a lower refractive index at the same time as compared to a polycarbonate resin having a structural unit derived from another bisphenol, the polycarbonate resin and The composition with another aromatic polycarbonate resin having complete compatibility has a refractive index and a glass transition temperature adjusted in a range intermediate between the two, and (b) bisphenol C and another bisphenol It has been found that the same effects as those of the resin composition (a) can be obtained with the aromatic polycarbonate resin obtained by copolymerization, and based on this, the resin composition of the present invention has been found.

That is, the present invention relates to a differential scanning calorimeter.
The following two components (1) exhibiting only one measured glass transition temperature and having an absolute value of the refractive index difference of 0.002 or less;
An optical resin composition containing (2), wherein the two components are completely compatible with (1) a polycarbonate resin (a) having a structural unit derived from bisphenol C, and (a), and (a) a composition comprising an aromatic polycarbonate resin having a higher refractive index and a higher glass transition temperature than (b), or an aromatic polycarbonate copolymer obtained from bisphenol C and another bisphenol compound
(c) and (2) a styrene resin containing α, β-unsaturated dicarboxylic anhydride or a derivative thereof as a copolymer component.

A method for producing a polycarbonate resin (a) having a structural unit derived from bisphenol C used in the present invention, and an aromatic polycarbonate resin having a glass transition temperature and a refractive index higher than those of the polycarbonate resin at the same time
As the production method of (b) , it is produced by the same production method as the conventional production method of polycarbonate. For example, those obtained by reacting an aromatic dihydric phenol compound with phosgene or a carbonic acid diester, or those produced by a transesterification method or the like. Further, the viscosity average molecular weight of the polycarbonate resin (a) having a constitutional unit derived from bisphenol C used in the present invention is in the range of 10,000 to 80,000, preferably in the range of 12,000 to 60,000.

[0011] 2 used in the preparation of the aromatic polycarbonate resin (b) having the higher glass transition temperature than the polycarbonate resin (a) having a structural unit derived from bisphenol C used in the invention and a high refractive index at the same time Examples of the divalent phenol compound include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane [referred to as bisphenol E], 2,2-bis (4-hydroxyphenyl) propane [bisphenol A
], 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) Sulfide, bis (4-hydroxyphenyl) ketone, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane,
2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3-chlorophenyl)
Propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxyphenyl)-
Examples thereof include 1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane and the like, which are used singly or in combination of two or more. Among them, a particularly preferred divalent phenol compound is bisphenol A
Or bisphenol E.

Further, one of these dihydric phenol compounds is
Species or two or more and a bisphenol C by copolymerizing Kaoru
Aromatic polycarbonate copolymer (c) and that Ru can be <br/> be. The aromatic polycarbonate resins (b) and (c) thus obtained have a molecular weight of 1 in terms of viscosity average molecular weight.
The range is from 000 to 80,000, preferably from 12,000 to 60,000.

[0013] Next definitive to the present invention (2) of the component alpha, beta-
Styrene monomers constituting a styrene resin having an unsaturated dicarboxylic anhydride or a derivative thereof as a copolymer component include styrene, o-methylstyrene, p-methylstyrene, α-methylstyrene, o-butylstyrene, and p-methylstyrene. butylstyrene, 2,4 - alkyl-substituted styrene are exemplified by dimethyl styrene, or chlorostyrene, and halogenated styrenes such as bromostyrene.

The α, β-unsaturated dicarboxylic anhydride or its derivative which is a copolymer component of the styrene resin is maleic anhydride, N-maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide. , N-phenylmaleimide, N-cyclohexylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide and the like.

The above-mentioned styrene monomer and a copolymer component
Α, β-unsaturated dicarboxylic anhydride or its derivative
Various combinations are possible with the conductor, but from the viewpoint of cost, refractive index, yellow coloring of the resin, etc., styrene and maleic anhydride copolymer by combination of styrene and maleic anhydride are practically used. Most preferred. As the styrene-maleic anhydride copolymer, those produced by polymerization methods such as bulk polymerization, solution polymerization, emulsion polymerization, and suspension polymerization, which are widely known, can be used. In these polymerization methods, a method in which necessary predetermined components are previously charged at the time of polymerization may be used, or a method in which predetermined components are sequentially added later may be used. After the polymerization reaction, the copolymer component may be subjected to amidation or imidation, or the like. The molecular weight of the styrenic resin used in the present invention may be in the range of 30,000 to 350,000.

The styrene monomer used in the present invention and the styrene monomer are used as a copolymer component.
The amount of the α, β-unsaturated dicarboxylic anhydride or its derivative is determined from the refractive index and the glass transition temperature of the obtained styrene resin. For example, regarding the amount of maleic anhydride in the case of a styrene-maleic anhydride copolymer,
Taking, for example, a case where the polycarbonate resin to be used is a combination of an aromatic polycarbonate resin having a structural unit derived from bisphenol A and a polycarbonate resin having a structural unit derived from bisphenol C, first, a styrene copolymer resin Is lower than the refractive index of the aromatic polycarbonate resin having the structural unit derived from bisphenol A, but not less than the refractive index of the polycarbonate resin having the structural unit derived from bisphenol C. Necessary from the viewpoint of physical properties. Therefore, the amount of maleic anhydride in the styrene-maleic anhydride copolymer having a refractive index in that range is in the range of 7% by weight to 20% by weight, and more preferably in the range of 12% by weight to 16% by weight. together easily adjustment of the polycarbonate resin is preferable easily adjust the glass transition temperature.

Among other α, β-unsaturated dicarboxylic anhydrides or derivatives thereof, the amount of the derivative other than maleic anhydride is appropriately determined according to the adjustment range of the refractive index in relation to the polycarbonate resin to be used. Things come.

In the present invention, the polycarbonate resin component (1) is completely compatible with the polycarbonate resin (a) having a structural unit derived from bisphenol C and has a glass transition temperature of the same. Obtained by uniformly kneading with other aromatic polycarbonate resin (b) higher than the polycarbonate resin within a specific range, or by copolymerizing bisphenol C with another dihydric phenol compound. Aromatic polycarbo
The desired glass transition temperature and refractive index can be adjusted to the desired values by the nate copolymer (c) . For example, when a polycarbonate resin having a structural unit derived from bisphenol A and an aromatic polycarbonate resin having a structural unit derived from bisphenol C are used, since both have perfect compatibility, the mixing ratio is changed. This makes it possible to arbitrarily produce a polycarbonate resin having physical properties such as an intermediate refractive index and a glass transition temperature between the two.

Polycarbonate with adjusted refractive index and glass transition temperature
Specific examples of carbonate resins
Polycarbonate having structural unit derived from phenol C
Composition derived from a carbonate resin and bisphenol A
The ratio with the polycarbonate resin having units is by weight.
Aromatic polycarbonate of 30 / 70-60 / 40
Resins are preferred.

Alternatively, a structure derived from bisphenol C
Polycarbonate resin having a structural unit and bisphenol
Polycarbonate having structural units derived from E
The ratio with the resin is 70/30 to 85/15 by weight.
Aromatic polycarbonate resins were also selected as suitable
It is.

Further, bisphenol C and bispheno
In the ratio of 30/70 to 60/40 by weight.
Polymerized aromatic polycarbonate copolymer,
Sphenol C and bisphenol E in a weight ratio of 70 /
Aromatic polycarbonate copolymerized at a ratio of 30 to 85/15
Bonate copolymers are also one of the preferred ones.

In the present invention, the above-mentioned polycarbonate resin whose refractive index and glass transition temperature have been adjusted and a styrene-based resin having an α, β-unsaturated dicarboxylic anhydride or its derivative as a copolymer component are simultaneously brought into close proximity to a glass. It is necessary to have a refractive index that is still approximately equal to the transition temperature.
For example, a styrene-maleic anhydride copolymer having a maleic anhydride content of 14.4% by weight has a glass transition temperature of 1
At 27 ° C., the refractive index is 1.582. When combining the styrene resin with the above-described polycarbonate resin having a constitutional unit derived from bisphenol C and the aromatic polycarbonate resin having a constitutional unit derived from bisphenol A, first, the derivative derived from bisphenol C
Is a polycarbonate resin having a viscosity average molecular weight of 16,000 having a glass transition temperature of 114 ° C., a refractive index of 1.578, and a viscosity average molecular weight of 16,000 having a structural unit derived from bisphenol A. Since the aromatic polycarbonate resin has a glass transition temperature of 140 ° C. and a refractive index of 1.585, when these two types of polycarbonate resins are mixed at a weight ratio of 1: 1,
A polycarbonate resin composition having a glass transition temperature of 127 ° C. and a refractive index of 1.582, which is an intermediate property between the two, can be obtained. The optical resin composition having uniform properties can be obtained.

[0023] As an optical resin composition, but the maintenance of transparency is an essential condition, in order to maintain the transparency,
It is necessary that the refractive index of each composition be approximately equal.
Transparency is closely related to light transmittance as a measure of brightness and haze as a measure of sharpness. Of these, the haze is substantially used as an optical material. For this purpose, a material having a content of 5.0% or less, preferably 3.0% or less is required. If the haze value is large, an optical lens or the like may become turbid due to the influence of scattered transmitted light, or a phenomenon in which an image to be transferred may be blurred. In the present invention, for the styrenic resin,
By setting the absolute value of the refractive index of the polycarbonate resin to 0.002 or less, almost the same refractive index is exhibited, so that an optically uniform resin composition is obtained. A resin composition having a low haze value while maintaining the same is obtained.

The optical resin composition obtained by the present invention comprises an aromatic polycarbonate resin having different optical anisotropy and a styrene resin, and the composition ratio of the aromatic polycarbonate and the styrene resin is adjusted. Thereby, a resin composition in which birefringence is substantially canceled can be obtained. In the present invention, the ratio of the composition comprising a polycarbonate resin having a structural unit derived from bisphenol C and an aromatic polycarbonate and a copolymer thereof is in the range of 5 to 95 parts by weight of the whole resin composition, preferably 40 to 50 parts by weight.
Within the range of 70 parts by weight, a resin composition having a low birefringence in which birefringence is substantially reduced as compared with polycarbonate can be obtained.

The method for obtaining the resin composition of the present invention includes:
There is no particular limitation, for example, a method in which necessary components are mixed in advance in a blender based on an assumed composition ratio, and then melt-kneaded at 230 ° C. to 320 ° C. using a vent-type extruder or the like, and pelletized. The method of melt kneading can be either a continuous type or a batch type, and may be carried out within the above-mentioned temperature range. Specific examples include a Banbury mixer, an extruder, and an injection molding machine. The optical resin composition obtained according to the present invention may optionally contain additives such as a heat stabilizer, an antioxidant, a light stabilizer, a lubricant, and an antistatic agent.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following synthesis examples and examples. However, the present invention is not limited to the following examples and many combinations are possible. In addition, each physical property was measured as follows.

[0027] Glass transition temperature, physical Electric Co. differential scanning calorimeter (DSC-8230) measured under a stream of nitrogen heating rate 5 ° C. / min, at a Atsushi Nobori range 50 ° C. to 250 DEG ° C. using did.

The refractive index was measured using a digital precision refractometer (KPR-20) manufactured by Kalnew Optical Co., Ltd.
The test was performed under the conditions of 5 ° C. and 50% humidity. The wavelength of the refractive index is 58
This is a value at the D line of 9.3 nm.

The viscosity average molecular weight was determined by the following equation by measuring the intrinsic viscosity [η] at 20 ° C. in a methylene chloride solvent using an Ubbelohde viscometer. [Η] = 1.11 × 10 ^-4 (Mv) ^0.83

For the measurement of the maleic anhydride content of the styrene-maleic anhydride copolymer, the polymer was dissolved in methylene chloride and titrated with a 1 / 10N methanolic solution of methoxysodium.

[0031] Synthesis Example 1 Sodium hydroxide 3.7kg dissolved in water 42 liters, while maintaining the 20 ° C., 2,2-bis (4-hydroxy-3-methylphenyl) propane [bisphenol C] 8.2 kg, 8 g of hydrosulfite was dissolved. To this, 28 liters of methylene chloride was added, and while stirring, pt-butylphenol (hereinafter referred to as “PT
BP] was added, and 3.6 kg of phosgene was blown in over 60 minutes. After the injection of phosgene was completed, the mixture was vigorously stirred to emulsify the reaction solution. After emulsification, 8 g of triethylamine was added, and the mixture was further stirred for about 1 hour to carry out polymerization. The polymerization liquid was separated into an aqueous phase and an organic phase, the organic phase was neutralized with phosphoric acid, and the process was repeated until the pH of the washing solution became neutral. Thereafter, 35 liters of isopropanol was added to precipitate the polymer. The precipitate was filtered and then dried to obtain a powdery polycarbonate resin. The viscosity average molecular weight of the obtained polycarbonate resin is 21,000, the glass transition temperature is 116 ° C., and the refractive index is 1.5.
It was 78. This polycarbonate is called DMPC-1.

[0032] except that the PTBP amount used in Synthesis Example 2 to 307 g, to obtain a polycarbonate resin by the same operation as in Synthesis Example 1. The viscosity average molecular weight of the obtained polycarbonate resin was 15,000, the glass transition temperature was 114 ° C., and the refractive index was 1.578.
This polycarbonate is called DMPC-2.

[0033] except that the PTBP amount used in Synthesis Example 3 in 81 g, to obtain a polycarbonate resin by the same operation as in Synthesis Example 1. As a result of measuring the viscosity of the obtained polycarbonate resin, the viscosity average molecular weight was 42,000, the glass transition temperature was 122 ° C., and the refractive index was 1.577. This polycarbonate is DMPC-
Three.

[0034] except that the PTBP amount used in Synthesis Example 4 to 53 g, to obtain a polycarbonate resin by the same operation as in Synthesis Example 1. The viscosity average molecular weight of the obtained polycarbonate resin was 59,000, the glass transition temperature was 123 ° C., and the refractive index was 1.577. This polycarbonate is called DMPC-4.

[0035] The divalent phenol-based compound used in Synthesis Example 5 Synthesis Example 1, and bisphenol E, and 307g of PTBP amount
The same operation as in Synthesis Example 1 was performed except for the above. The viscosity average molecular weight of the obtained polycarbonate resin was 16,300, the glass transition temperature was 130 ° C., and the refractive index was 1.594. This polycarbonate is called BPE-PC.

[0036] The divalent used in the phenolic compound Synthesis Example 6 Synthesis Example 1, bisphenol - except Le A and bisphenol C, respectively to use 4.1kg is the same procedure as Synthesis Example 1 Was. The viscosity average molecular weight of the obtained polycarbonate resin is 21,000, the glass transition temperature is 128 ° C., and the refractive index is 1.58.
Was 2. This polycarbonate is called DMPC-5.

[0037] Example 1 Polycarbonate resin derived from bisphenol A (Mitsubishi Gas Chemical Co., polycarbonate (trade name "Iupilon H-4000"), a viscosity-average molecular weight of 16,000,
A glass transition temperature of 140 ° C., a refractive index of 1.586, hereinafter referred to as BPA-1), a bisphenol C-type polycarbonate DMPC-1 of Synthesis Example 1, and a styrene-maleic anhydride copolymer (trade name “Dilark # 33
2 "), glass transition temperature 126 ° C, refractive index 1.582, maleic anhydride content 14.3% by weight, hereinafter referred to as St-A)
Were mixed using a tumbler in the proportions shown in Table 1.

[0038] The mixed powder temperature 230 ° C. using a vented extruder (Nakatani Machinery Co., Ltd. AS-30)
The mixture was melt-kneaded at ~ 280 ° C and pelletized. The glass transition temperature of the obtained pellet was measured using a differential scanning calorimeter. As a result, the peak of the glass transition temperature of this composition was 123 ° C. After drying the pellets at 110 ° C for 1 hour, the cylinder temperature is 240 ° C to 300 ° C, and the mold temperature is 90 ° C to
Injection molding machine at 110 ° C (SA-3 manufactured by Yamashiro Seiki Seisakusho Co., Ltd.)
Using 0) to form a disk 50mm in diameter × 3mm thick,
Haze meter (Nippon Denshoku model 1001DPZ)
Was used to measure the total light transmittance and the haze value. as a result,
The light transmission was 89.9% and the haze was 0.9%.

As described above, these two types of polycarbonate resins were used in a weight ratio of BPA-1: DMPC-1 = 5.
The resin composition mixed at a ratio of 5:45 is a polycarbonate resin composition having a glass transition temperature of 127 ° C. and a refractive index of 1.582. When this and the above-mentioned styrene-based resin are melt-kneaded, an optical resin composition which is optically uniform and has uniform thermal properties can be obtained.

[0040] In Example 2-5, Comparative Examples 1-5 Examples 2-5 and Comparative Examples 1-5, DMPC-1 and B
The mixing ratio with PA-1 was mixed at the ratio shown in Table 1, and the same operation as in Example 1 was performed.

[0041] Example 6-8 DMPC-2 synthesized in Synthesis Example 2~4, DMPC-
3. DMPC-4 was mixed with BPA-1 at the ratio shown in Table 1 and the same operation as in Example 1 was performed.

[0042] carried out mixing in the proportions indicated in various styrene-based resin and Table 1 with DMPC-1 synthesized in Comparative Example 6-7 Synthesis Example 1, Example 1
The same operation as described above was performed. The St-B resin used at this time was a styrene-maleic anhydride copolymer (MTC-AR
CO (trade name “Dilark # 232”), glass transition temperature 115 ° C., refractive index 1.587, maleic anhydride content 7.4% by weight, and St-C resin made of polystyrene (Monsanto Kasei Co., Ltd.) (Product name "Dialex"
HH102 ” ), glass transition temperature 97 ° C., refractive index = 1.59
2).

[0043] The DMPC-1 synthesized in Example 9 Synthesis Example 1, a polycarbonate resin (Mitsubishi Gas Chemical Co., polycarbonate (trade name having a structural unit derived different from bisphenol A of BPA-1 and molecular weight " Iupilon E-200
0 "), viscosity average molecular weight 28,000, glass transition temperature 145
° C, refractive index 1.586, hereinafter referred to as BPA-2) and Synthesis Example 1
Was mixed with a polycarbonate resin having a structural unit derived from bisphenol C at a ratio shown in Table 1, and the same operation as in Example 1 was performed.

[0044] The DMPC-1 synthesized in Example 10 Synthesis Example 1, using the BPE-PC synthesized in Synthesis Example 5 was subjected to the same procedure as in Example 1.

Example 11 DMPC-5 synthesized in Synthesis Example 6 was mixed with St-A, and the same operation as in Example 1 was performed.

[0046] The DMPC-1 synthesized in Example 12-13 Synthesis Example 1, using BPA-1, and mixed and by changing the ratio between St-A in the proportions shown in Table 1, Example 1 The same operation as described above was performed.

The ratio of DMPC-1 and BPA-1 of Examples 14 and 15 Example 1 was directly used as, a mixing ratio indicating the ratio between St-A in Table 2,
The same operation as in Example 1 was performed .

[0048] For the Examples 1 to 13 and Comparative Examples 1 to 7
Table 1 shows the results of the tests.
15 is shown in Table 2. In addition, "real" in the table is an example.
, And “ratio” indicates a comparative example .

[0049]

As described above, the resin composition of the present invention is an optical resin composition having a reduced birefringence than the polycarbonate resin alone without impairing the excellent transparency of the polycarbonate itself. It is. Furthermore, since the resin composition obtained by the present invention shows only one glass transition temperature measured by a differential scanning calorimeter, the molding cycle can be shortened, and an optical lens, an optical disk, and an optical card can be shortened. it is possible to improve the productivity of the molded product for optical applications and the like.

[0050]

[Table 1]

[0051]

[Table 2]

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Satoshi Kanayama 5-6-1, Higashi-Hachiman, Hiratsuka-shi, Kanagawa Pref. Examiner, Plastics Center, Mitsubishi Gas Chemical Co., Ltd. Satoshi Morikawa (56) References JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C08L 25/08 C08L 69/00

Claims (12)

(57) [Claims] (1) Only one glass transition temperature measured by a differential scanning calorimeter is shown , and the absolute value of the refractive index difference is 0.002.
An optical resin composition containing the following two components (1) and (2). (1) a polycarbonate resin (a) having a structural unit derived from 2,2-bis (4-hydroxy-3-methylphenyl) propane, which is completely compatible with (a), and A composition comprising an aromatic polycarbonate resin (b) having a high refractive index and a high glass transition temperature, or 2,2-
Aromatic polycarbonate copolymer (c) of bis (4-hydroxy-3-methylphenyl) propane and another bisphenol compound. (2) A styrene resin containing α, β-unsaturated dicarboxylic anhydride or its derivative as a copolymer component. 2. The optical resin composition according to claim 1, wherein the proportion of the component (1) is 5 to 95 parts by weight based on the whole resin composition. 3. An aromatic polycarbonate resin (b) comprising 2,2
The optical resin composition according to claim 1, which is a polycarbonate resin having a structural unit derived from bis (4-hydroxyphenyl) propane or 2,2-bis (4-hydroxyphenyl) ethane. 4. The aromatic polycarbonate copolymer (c) is
2,2-bis (4-hydroxy-3-methylphenyl) propane and 2,2-bis (4-hydroxyphenyl) propane or
The optical resin composition according to claim 1, which is a copolymer with 2,2-bis (4-hydroxyphenyl) ethane. 5. The polycarbonate resin (a) having a structural unit derived from 2,2-bis (4-hydroxy-3-methylphenyl) propane has a viscosity average molecular weight of 10,000.
2. The optical resin composition according to claim 1, wherein the amount is in the range of 0 to 60,000. 6. A 2,2-bis (4-hydroxy-3-methyl)
(Phenyl) propane having structural units derived from propane
Carbonate resin and 2,2-bis (4-hydroxy
Nyl) Polycarbonate having structural units derived from propane
Ratio of the Boneto resins are in a weight ratio of 30 / 70-60 /
4. The optical resin composition according to claim 3, wherein the number is 40. 7. A copolymer of 2,2-bis (4-hydroxy-3-methylphenyl) propane and 2,2-bis (4-hydroxyphenyl) propane in a weight ratio of 30/70 to 60/40.
The optical resin composition according to claim 4, which is a copolymer (c) . 8. An α, β-unsaturated dicarboxylic anhydride comprising:
The optical resin composition according to claim 1, which is maleic anhydride. 9. styrenic resin is a copolymer of maleic anhydride and styrene compounds, free in the copolymer
The ratio of maleic acid in water is 12 to 16% by weight.
The optical resin composition according to the above. 10. A single glass transition temperature in the range of 116 ° C. to 128 ° C., and the absolute value of the refractive index difference between the component (1) and the component (2) is within 0.002. The optical resin composition according to claim 1, 11. A 2,2-bis (4-hydroxy-3-methyi)
Ruphenyl) having structural units derived from propane
Polycarbonate resin and 2,2-bis (4-hydroxy
Enyl) poly-containing structural units derived from propane
70 / 30-85 by weight ratio with the carbonate resin
The optical resin composition according to claim 3, wherein the ratio is / 15. 12. A 2,2-bis (4-hydroxy-3-methylfuran)
Phenyl) propane and 2,2-bis (4-hydroxyphenyl)
Propane at a ratio of 70/30 to 85/15 by weight
The optical tree according to claim 4, which is a polymerized copolymer (c).
Fat composition.