JPH05230359A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition, excellent in transparency, reduced in birefringence ratio, having excellent mechanical properties and moldability and useful as optical disks, etc., by blending a polycarbonate with a specific amount of a vinylic polymer having OH at the terminal or in the main chain. CONSTITUTION:The objective composition is obtained by blending (A) 10-100 pts.wt. polycarbonate (preferably bisphenol A having 5000-100000 number-average molecular weight) with (B) 10-100 pts.wt. vinylic polymer having >=10 equiv./10<6>g (preferably >=30 equiv./10<6>g OH at the terminal or in the main chain).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition comprising a polycarbonate and a modified vinyl polymer having a hydroxyl group, which is excellent in transparency, has a greatly reduced birefringence, and has excellent mechanical properties and moldability. It is about.

[0002]

2. Description of the Related Art A resin composition comprising a polycarbonate and a vinyl polymer is known. In particular, a resin composition composed of polycarbonate and polystyrene can theoretically have a birefringence of zero (Takashi Inoue, Taku Saito: Functional Materials, P21, March 1987 issue). It is expected to be applied to.

However, since polycarbonate and polystyrene have poor compatibility with each other, transparency is impaired in a composition simply blended, the effect of reducing the birefringence is not recognized, and the mechanical properties are greatly deteriorated. was there. For example, Japanese Patent Application Laid-Open No. 61-108617 discloses a resin composition composed of polycarbonate having a positive polarizability and polystyrene having a negative polarizability, but the above problem has not been solved.

In order to solve such a problem, there has been disclosed a resin composition in which either polycarbonate or vinyl polymer is chemically modified. For example, Japanese Patent Application Laid-Open No. 61-19656 discloses a resin composition in which 5 to 50% by weight of a styrene resin copolymerized with an unsaturated carboxylic acid is mixed with a polycarbonate.
Further, JP-A-63-27555 and JP-A-63-56.
556 and JP-A-63-66255, a styrene-based polymer is added to a copolycarbonate in an amount of 3 to 50.
A resin composition blended by weight% is disclosed. Further, JP-A-63-122749 discloses a composition in which a copolymer of styrene and maleic anhydride is added to polycarbonate. However, even the resin compositions disclosed in these publications have an insufficient effect of improving the compatibility, and the above problems still remain.

Also disclosed is one in which polycarbonate and a vinyl-based polymer are chemically bonded. For example, in JP-A-61-19630, 5-40% by weight of polystyrene is chemically bonded. Polycarbonates are disclosed. Further, JP-A-62-20524 discloses a polycarbonate in which a styrene-based copolymer is chemically bonded. These are block copolymers or graft copolymers obtained by polymerizing the monomers constituting the other polymer from the active end of one polymer obtained by polymerization in advance. It can be said that these copolymers were obtained by utilizing the chemical reaction between the macromer and the monomer.

However, in this chemical reaction, the amount of the homopolymer composed of the monomers is adjusted because the reaction between the monomers takes place stochastically over the reaction between the macromer and the monomer. However, there is a problem that the number of the block or graft copolymers is overwhelmingly larger. Therefore, even in these block or graft copolymers, excellent transparency,
It has not been realized to obtain a resin composition having a significantly reduced birefringence and excellent mechanical properties and moldability.

As described above, in a conventional resin composition comprising a polycarbonate and a vinyl polymer, transparency is obtained, but the birefringence is not sufficiently reduced, or mechanical properties and moldability are deteriorated. On the other hand, problems such as inferiority occur, excellent transparency, birefringence is greatly reduced, and a resin composition having excellent mechanical properties and moldability is expected to be applied to optical devices. Despite this, the reality is that it has not been obtained yet.

[0008]

In view of such circumstances, an object of the present invention is to provide a polycarbonate and a vinyl which are excellent in transparency, have a greatly reduced birefringence, and have excellent mechanical properties and moldability. It is to provide a resin composition comprising a polymer. Another object of the present invention is to provide a resin composition suitable for an optical device such as an optical disk, an optical fiber, an optical card protective film or a lens.

[0009]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to solve such problems, a resin composition comprising a polycarbonate and a specific vinyl polymer having a hydroxyl group has excellent transparency. Further, they have found that the birefringence is greatly reduced, and that they are excellent in mechanical properties and moldability, and have reached the present invention.

That is, the gist of the present invention comprises (a) 10 to 100 parts by weight of a polycarbonate and (b) 10 to 100 parts by weight of a vinyl polymer having at least 10 equivalents / 10 ⁶ g of a hydroxyl group at the terminal or main chain. It is a resin composition.

The present invention will be described in more detail. The polycarbonate used in the present invention is an aromatic polycarbonate obtained from bisphenols and carbonic acid. Such bisphenols include bisphenol A, bisphenol AP, hydroquinone, resorcinol, 4,4'-
Dihydroxybiphenyl, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, bis (4-hydroxyphenyl) methane, bis (4- Hydroxyphenyl) ethane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, bis (3,3
5-diethyl-4-hydroxyphenyl) methane, 1,
1-bis (3,5-dimethyl-4-hydroxyphenyl) ethane, 1,1-bis (3,5-diethyl-4-hydroxyphenyl) ethane, 1,1-bis (3,5-dimethyl-4-) Hydroxyphenyl) propane, 2,2-
Bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (3,5-diethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-diethyl-4-hydroxyphenyl) ) Propane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) butane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) butane, 1,1-bis (3,5) -Diethyl-
4-hydroxyphenyl) butane, 2,2-bis (3,3
5-diethyl-4-hydroxyphenyl) butane, 1,
1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-diethyl-4-hydroxyphenyl) cyclohexane, bis (3,5-dimethyl-4-hydroxyphenyl) phenyl Methane, bis (3,5-diethyl-4-hydroxyphenyl) phenylmethane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) -1-phenylethane, 1,1-bis (3,5) -Diethyl-4-hydroxyphenyl) -1-phenylethane, bis (3,5-dimethyl-4-hydroxyphenyl) diphenylmethane, bis (3,5-diethyl-4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) ) Ether, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (3,5 Diethyl-4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, bis (3,5-diethyl-4-hydroxyphenyl) sulfide, bis ( Four
-Hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone, bis (3,3
5-diethyl-4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis (3,5-
Examples thereof include dimethyl-4-hydroxyphenyl) ketone, bis (3,5-diethyl-4-hydroxyphenyl) ketone, and 4,4′-dihydroxybiphenyl. These may be used alone or in combination. Of these, bisphenol A is most preferred.

Polycarbonate can be produced by a melt polymerization method or an interfacial polymerization method. In the melt polymerization method, for example,
Polycarbonate is obtained by reacting diphenyl carbonate and bisphenols at high temperature under reduced pressure.
In the interfacial polymerization method, bisphenols are dissolved in an alkaline aqueous solution, and phosgene is blown into the solution while mixing and stirring with an organic solvent which is incompatible with water to obtain a polycarbonate. Compared with the melt polymerization method, the interfacial polymerization method can provide a polycarbonate with less coloring.

The molecular weight of the polycarbonate used in the present invention is not particularly limited, but the number average molecular weight is 5,000.
It is preferably 100 to 100,000. When the number average molecular weight is less than 5,000, the mechanical performance of the resin composition tends to decrease, which is not preferable. On the contrary, if it exceeds 100,000, the moldability tends to decrease, which is not preferable.

The vinyl polymer used in the present invention contains at least 10 equivalents / 10 ⁶ hydroxyl groups in the terminal or main chain.
g. More preferably at least 30
It has an equivalent weight / 10 ⁶ g. 10 equivalents of hydroxyl group
If it is less than 10 ⁶ g, it is difficult to obtain a transparent resin composition. On the other hand, when the hydroxyl group exceeds 300 equivalent / 10 ⁶ g, gel may be generated during melt-kneading, which is not preferable.

The number average molecular weight of this vinyl polymer is preferably 1,000 to 200,000. If the number average molecular weight is less than 1,000, the physical properties of the resin composition, especially mechanical properties tend to deteriorate, and conversely 200,00.
When it exceeds 0, not only the moldability of the resin composition is lowered, but also the transparency thereof is lowered and the birefringence is increased, which is not preferable.

As the vinyl-based monomer constituting the vinyl-based polymer, in addition to styrene, for example, o-, m-, p-
Methylstyrene, o-, m-, p-ethylstyrene, p
Alkyl styrenes such as -tert-butyl styrene, halogenated styrenes such as o-, m-, p-chlorostyrene, dichlorostyrene, o-, m-, p-bromostyrene and dibromostyrene, and α-methyl Styrene and the like, and mixtures thereof. Further, in order to improve the physical properties, the vinyl polymer contains 0 to 50 mol% of other vinyl monomers such as methacrylic acid esters, acrylic acid esters, vinyl acetate, butadiene, acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride. Etc. can be copolymerized.

As a method for producing the vinyl polymer, a general radical polymerization method can be used, but the method is not limited to this, and an anionic polymerization method or a cationic polymerization method can be appropriately used. For example, in the radical polymerization method, if a hydrogen peroxide-ferrous iron ion redox initiator is used, a vinyl polymer having a hydroxyl group at the terminal can be easily obtained. Further, for example, a vinyl polymer having a hydroxyl group at the terminal can be obtained by performing anionic polymerization of styrene using sodium naphthalene as an initiator and treating the obtained polymer with ethylene oxide. A vinyl polymer having a hydroxyl group in its main chain can also be obtained by copolymerizing vinyl acetate and then saponifying it.

The blending ratio of the polycarbonate of the component (a) constituting the resin composition of the present invention and the vinyl polymer containing at least 10 equivalents / 10 ⁶ g of hydroxyl groups at the terminal or main chain of the component (b) is the component (a). 10 to 100 parts by weight,
The component (b) is 10 to 100 parts by weight. When the amount of the component (a) is less than 10 parts by weight, not only the heat resistance of the resin composition is lowered, but also the impact strength and the mechanical strength are lowered. On the contrary, when the amount of the component (a) exceeds 100 parts by weight, the moldability of the resin composition is deteriorated. Similarly, when the amount of the component (b) is less than 10 parts by weight, the moldability is lowered. Also, (b) component is 10
If it exceeds 0 part by weight, not only the heat resistance of the resin composition is lowered, but also the impact strength and the mechanical strength are lowered.
If both the components (a) and (b) deviate from the blending ratio, the birefringence increases.

The resin composition of the present invention is obtained by melt-kneading the polycarbonate as the component (a) and the vinyl polymer having a hydroxyl group at the terminal or main chain of the component (b) under the conditions described below. In that case, it is possible to carry out melt-kneading using a general extruder or injection molding machine.
In general, both the polycarbonate of component (a) and the vinyl polymer of component (b) are amorphous, so the temperature of melt kneading is at least higher than the glass transition temperature of the polymer of both component (a) and component (b). It is preferably 50 ° C. higher. In any case, the resin composition may be decomposed at a temperature of 350 ° C. or higher, which is not preferable.

In the present invention, the object of the present invention is achieved by melt-kneading the polycarbonate as the component (a) and the vinyl polymer having a hydroxyl group as the component (b). In other words, it has excellent transparency that has been expected from the past,
The present invention provides, for the first time, a resin composition composed of a polycarbonate and a vinyl-based polymer, which has a significantly reduced birefringence and has excellent mechanical properties and moldability.

In the present invention, it is preferable that the polycarbonate as the component (a) and the vinyl polymer having a hydroxyl group in the terminal chain or the main chain of the component (b) are sufficiently dried to remove water before melt-kneading. In some cases, a vent port may be provided in the extruder for simultaneous dehydration during melt-kneading. Moisture content is 0.5% by weight per resin composition
It is preferable to melt-knead while suppressing the amount to the following. When melt-kneading is performed at a water content of more than 0.5% by weight, it tends to be difficult to obtain a resin composition having physical properties in which hydrolysis of the polycarbonate constituting the resin composition is remarkably satisfactory.

In the present invention, a transesterification catalyst may be further added, if desired. In this case, a transparent resin composition can be obtained more easily. However, since the resin composition produced by adding the transesterification catalyst may be decomposed in a hot melt molding process such as injection molding later, it is also preferable to further use a phosphorus compound in order to prevent the decomposition.

The transesterification catalyst is used if necessary, but the general blending amount is 0.00001 to 0.1 part by weight based on 100 parts by weight of the resin composition. Further, the general compounding amount of the phosphorus compound, which is also used as needed, is 0.0001 to 3 parts by weight with respect to 100 parts by weight of the resin composition.

As the ester polymerization catalyst, a known general polymerization catalyst for polyester can be used. Examples of such catalysts are Na, Mg, Zn, Cd, Ti, G
Examples include metal acetates such as e, Pb, Sb, and Sn, alkoxides, hydroxides, oxides, halides, sulfates, carbonates, phosphates, and acidic compounds such as p-toluenesulfonic acid. ..

Phosphorus compounds include orthophosphoric acid, phosphonic acid, orthophosphoric acid esters and phosphorous acid esters. Among them, phosphite is most preferably used,
Examples of the phosphite include alkyl phosphite, aryl phosphite, alkyl aryl phosphite, diphosphite, polyphosphite, and thiophosphite. Specific examples of these are:
Diisooctyl phosphite, distearyl phosphite, triisodecyl phosphite, triisooctyl phosphite, trilauryl phosphite, tristearyl phosphite, diphenyl phosphite, trisnonyl phenyl phosphite, triphenyl phosphite,
Diphenyl isodecyl phosphite, diphenyl isooctyl phosphite, phenyl diisodecyl phosphite, diisodecyl pentaerythritol diphosphite, tetraphenyl dipropylene glycol diphosphite, poly (dipropylene glycol) phenyl phosphite, trilauryl thiophosphite, tetrakis (2,4-ditertiarybutylphenyl) -4,4 '
-Biphenylenediphosphite and the like can be mentioned.

Further, if necessary, another polymer may be added to the resin composition of the present invention. Examples of such a polymer include polybutadiene, butadiene-styrene copolymer, acrylic rubber, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, natural rubber, chlorinated butyl rubber, chlorinated polyethylene, styrene-butadiene. Elastomers such as block copolymers, butadiene-styrene radial tereblock copolymers,
Styrene-maleic anhydride copolymer, styrene-phenylmaleimide copolymer, polyethylene, polypropylene, butadiene-acrylonitrile copolymer, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyvinylidene fluoride, polysulfone, polyphenylene sulfide, Examples thereof include polyether sulfone, phenoxy resin, polyphenylene ether, polymethyl methacrylate, polyether ketone, polyamide, polyarylate, and polytetrafluoroethylene.

Further, the resin composition of the present invention contains a heat stabilizer, an antioxidant, and
It is also possible to add weathering agents, flame retardants, plasticizers, release agents, colorants, reinforcing agents and the like. Examples of heat stabilizers and antioxidants include hindered phenols, hindered amines, sulfur compounds, copper compounds, and mixtures thereof. Examples of the reinforcing material include clay, talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, asbestos, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, and water. Aluminum oxide, calcium hydroxide, barium sulfate, potassium alum, sodium alum, iron alum,
Glass balloon, carbon black, zinc oxide, antimony trioxide, boric acid, borax, zinc borate, zeolite, hydrotalcite, metal fiber, metal whiskers,
Ceramic whiskers, potassium titanate, ticker boron,
Examples thereof include mica, graphite, glass fiber and carbon fiber. Additives such as these heat stabilizers, antioxidants, weather resistance agents, flame retardants, plasticizers, release agents, colorants, and reinforcing agents are generally preferably added during melt kneading.

The resin composition of the present invention can be made into a desired molded article by a usual molding processing method. For example, hot melt molding methods such as injection molding, extrusion molding, blow molding, and sintering molding can be applied. Alternatively, a thin film can be formed from an organic solvent solution by a casting method. The resin composition of the present invention is excellent in transparency, has a greatly reduced birefringence index, and is excellent in mechanical properties and moldability, so various molded products, films and sheets, particularly optical disks, optical fibers, and optical guards. It is also suitably used for optical applications such as protective films and lenses.

[0029]

A resin composition obtained by simply melt-kneading a conventional polycarbonate and a general vinyl polymer is not only poor in transparency and high in birefringence but also inferior in mechanical properties. On the other hand, the resin composition of the present invention exhibits extremely excellent properties as described above, and there is a significant difference in the effect among these resin compositions. It is considered that this is because in the resin composition of the present invention, some kind of chemical reaction occurs between the hydroxyl group contained in the vinyl polymer of the component (b) and the polycarbonate of the component (a) during the melt-kneading. The facts suggesting that a chemical reaction is occurring include the amount of cyclohexane extracted from the resin composition. The resin composition of the present invention has a particularly small amount of extraction when extracted with cyclohexane, is excellent in transparency, and has a greatly reduced birefringence. On the other hand, a conventional resin composition using a general vinyl polymer,
When extracted with cyclohexane, the amount of extraction is large,
Opaque and inferior in mechanical properties. Thus, in the resin composition of the present invention, it is considered that a chemical reaction takes place between the polycarbonate and the vinyl polymer, and therefore the transparency is excellent, the birefringence is greatly reduced, and the mechanical properties and moldability are excellent. It is considered to be excellent.

[0030]

The present invention will be specifically described with reference to the following examples.
In the present invention, each characteristic value was measured by the following method.

(1) Molecular Weight The molecular weight was measured by gel permeation chromatography calibrated with monodisperse polystyrene using a GPC measuring device HLC-802A manufactured by Toyo Soda Co., Ltd.

(2) Hydroxyl group A vinyl polymer was dissolved in pyridine, acetic anhydride was added to this to acetylate the hydroxyl group, and excess acetic anhydride was titrated with sodium hydroxide.

(3) Extraction amount of cyclohexane Using 50 parts by weight of cyclohexane per 1 part by weight of the resin composition, extraction was performed for 26 hours using a Soxhlet extractor. Polycarbonate simple substance is not extracted into cyclohexane, and vinyl polymer simple substance is extracted into this. The evaluation of the cyclohexane extraction amount of the resin composition is a value (% by weight) obtained by dividing the weight of the extracted resin by the weight of the raw material vinyl polymer constituting the resin composition.

(4) Light transmittance The pellets of the obtained resin composition were vacuum dried at 80 ° C. for 16 hours, and then the cylinder temperature was 260 ° C. and the mold temperature was 80 ° C.
Injection molding was performed to prepare a test piece having a side of 5 cm and a thickness of 3 mm. Molding machine is Mitsubishi Heavy Industries 125/75
An MST type molding machine was used. However, in Comparative Example 2, only the cylinder temperature was changed to 280 ° C, and in Comparative Example 3, the temperature was changed to 220 ° C and molding was performed. ASTM D10 using this test piece
Based on No. 03, the total light transmittance was measured. The measurement was performed using an SZ-Σ80 type colorimeter manufactured by Nippon Denshoku Co., Ltd.

(5) Birefringence The resin composition is dissolved in methylene chloride to prepare a 20% by weight solution, which is manufactured by Yasuda Seiki Co., Ltd.
replicator No. A 100 μm thick film was made using 542-AB-S. Film 12
Allow to stand at room temperature for 12 hours and then in a vacuum dryer at 100 ℃ for 12 hours.
The solvent was removed by drying for an hour. Using the hot air circulation type uniaxial stretching device manufactured by Satake Chemical Machinery Co., Ltd.
The film was stretched at 5 to 220 ° C. for 10 to 50%, and the birefringence of the film was measured with an optical-pol polarizing microscope (wavelength 546 nm) manufactured by Nikon Corporation.

(6) Bending strength and flexural modulus Injection molding was performed under the same conditions as the sample for measuring light transmittance,
A 1/8 inch bending test piece was prepared. The flexural strength and flexural modulus of the obtained test piece were measured based on ASTM D790.

(7) Izod Impact Test An Izod impact test was conducted using the same test piece as in (6) above. The measurement was performed based on ASTM D256.

(8) Deflection temperature under heat load (HDT) Using the same test piece as in (6) above, the deflection temperature under heat load (H
DT) was measured. The measurement was performed based on ASTM D648, and the load was 18.6 kg / cm ² .

Reference Example 1 Vinyl-based polymer (S1, S2,
Synthesis example of S3, S5) The reaction tank was cooled to −30 ° C. and sufficiently replaced with nitrogen, and then 200 parts by weight of distilled water, 100 parts by weight of styrene and 0.6 part by weight of sodium dodecylbenzenesulfonate were placed in the reaction tank. In addition, while stirring the reaction layer, 30% hydrogen peroxide solution and 1% ferrous sulfate aqueous solution were continuously added at a volume ratio of 8: 3, respectively. In the conventional emulsion polymerization method, four kinds of vinyl-based polymers (S
1, S2, S3 and S5) were obtained. The molecular weight and the amount of hydroxyl groups of the obtained vinyl polymers S1, S2, S3 and S5 were measured. The results are listed in Table 1.

Reference Example 2 Synthesis Example of Vinyl Polymer (S4) Having Hydroxyl Group in Main Chain Using benzoyl peroxide as a polymerization initiator, 100 parts by weight of styrene and 0.10 part by weight of vinyl acetate were radically heated at 90 ° C. Polymerization yielded a vinyl polymer having an acetyloxy group in the main chain. This was saponified with a potassium hydroxide solution to obtain a vinyl polymer (S4) having a hydroxyl group in the main chain. The molecular weight and hydroxyl group of this S4 were measured. The results are listed in Table 1.

Reference Example 3 Synthesis Example of Vinyl Polymer (S6) Not Having Hydroxyl Group Using benzoyl peroxide as a polymerization initiator, styrene 1
Radical polymerization of 00 parts by weight at 90 ° C. was carried out to obtain a vinyl polymer (S6) having no hydroxyl group, and the molecular weight and hydroxyl group were measured. The results are listed in Table 1.

[0042]

[Table 1]

The polycarbonate used in Examples and Comparative Examples has a number average molecular weight of 30,000 consisting of bisphenol A and carbonic acid (Mitsubishi Gas Chemical Co., Inc., Iupilon 1000) and a number average molecular weight of 20,000 ( Mitsubishi Gas Chemical Co., Inc., Iupilon 3000).

Examples 1 to 12 Raw materials having the formulations shown in Tables 2 and 3 were vacuum dried at 120 ° C. for 16 hours, and then melted at a cylinder temperature of 260 ° C. using a twin-screw extruder (PCM45, manufactured by Ikegai Steel Co., Ltd.). The mixture was kneaded, extruded, and cut into pellets. In each case, good pelletization was possible. During the melt-kneading, the pressure was reduced to 50 mmHg or less using the vent port of the cylinder. Various test pieces were obtained using the pellets of the obtained resin composition, and various performance evaluations shown in Tables 2 and 3 were performed. The results are shown in Table 2 and Table 3 together.

[0045]

[Table 2]

[0046]

[Table 3]

Comparative Examples 1 to 7 The raw materials having the formulations shown in Table 4 were melt-kneaded and extruded in the same manner as in Examples, and then cut into pellets to prepare test pieces. Was evaluated. The results are shown together in Table 4.

[0048]

[Table 4]

As is clear from each example, (a) 10 to 100 parts by weight of polycarbonate and (b) 100 to 10 parts by weight of a vinyl polymer having at least 10 equivalents / 10 ⁶ g of hydroxyl groups at the terminal or main chain. It is clear that the resin composition obtained by melt-kneading is excellent in transparency, has a significantly reduced birefringence, and is excellent in mechanical properties and moldability.

[0050]

The resin composition of the present invention has excellent transparency,
The birefringence is greatly reduced, and the mechanical properties and moldability are excellent. Therefore, the resin composition of the present invention is suitably used for various molded products, films, sheets, particularly optical devices such as optical disks, optical fibers, optical card protective films and lenses.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Megumi Ogasa 23 Uji Kozakura, Uji City, Kyoto Prefecture Unitika Ltd. Central Research Laboratory

Claims (1)

[Claims] 1. (a) 10 to 100 parts by weight of polycarbonate and (b) at least one hydroxyl group at the terminal or main chain.
Vinyl-based polymer having 0 equivalent / 10 ⁶ g 10-100
A resin composition comprising 1 part by weight.