JP2001011167A - Polycarbonate resin for producing substrate of optical information medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin having high melt fluidity and excellent optical characteristics such as low birefringence by including specific bonding units of different kinds from the main structural unit in the transesterification reaction of an aromatic dihydroxy compound with a carbonic acid diester. SOLUTION: This resin is obtained by the transesterification of an aromatic dihydroxy compound of the formula HO-Ar-OH (wherein Ar is a 5-200C aromatic group) with a carbonic acid diester of formula I (wherein Ar3 and Ar4 are each a 5-200C aromatic group). The main chain of the resin contains a repeating unit A of formula II and bonding units B and C of different kinds from the repeating unit A, which are expressed by formula III (wherein X is a polycarbonate chain containing a repeating unit of formula IV and having a weight average molecular weight of 214-6,000) and formula V, respectively. The total quantity of the bonding units B and C makes up 0.03-0.3 mol% based on the total mol quantity of the unit A. The quantity of the unit B makes up >=50 mol% based on the total quantity of ingredients B and C. The weight average molecular weight of the resin is 13,000 to 18,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polycarbonate resin for manufacturing a substrate for an optical information medium. More specifically, the present invention relates to a substantially chlorine-free polycarbonate resin produced by subjecting an aromatic dihydroxy compound and a carbonic acid diester to a transesterification reaction, and comprising a plurality of aromatic polycarbonate main chains. The plurality of polycarbonate backbones as a whole has a specific amount of specific heterogeneous units (A) and (B) on the polycarbonate backbone, and has a weight average molecular weight of 13,000 to 1
8,000 polycarbonate resins.

Since the polycarbonate resin of the present invention exhibits high melt fluidity at the time of injection molding, when the polycarbonate resin of the present invention is used for producing a substrate for an optical information medium, excellent optical properties such as low birefringence are obtained. Because it has high transferability (that is, information of a stamper (a mold for forming grooves and pits on a substrate) is accurately transferred).
It is possible to obtain a substrate which can be advantageously used as a substrate for an optical information medium having a high recording density such as D. Furthermore, the present invention relates to a polycarbonate resin composition comprising the above polycarbonate resin and an acidic compound, and a substrate for an optical information medium obtained by molding the above polycarbonate resin or the above polycarbonate resin composition.

[0003]

2. Description of the Related Art Polycarbonate is widely used in many fields as engineering plastics having excellent heat resistance, impact resistance, transparency and the like.
In particular, with the progress of computerization in recent years, the demand for polycarbonate for use in music and video recording media and digital information recording media such as personal computers has been expanding. Polycarbonates are CDs, CD-ROMs, CD-Rs, and DVDs. -RO
It has become an indispensable resin for manufacturing optical disks such as M, DVD-R, MO, and MD, optical cards, and the like.

In the production of a substrate for an optical information medium such as an optical disk, it is necessary to accurately form fine grooves and pits. Excellent optical characteristics such as low birefringence are required. Therefore, a low-molecular-weight polycarbonate having a high fluidity and a weight-average molecular weight of about 15,500 is currently used for manufacturing an optical information medium substrate. However, in recent years, the transition from a conventional CD to a DVD having an increased recording density has begun. It is necessary to form very fine grooves and pits on the optical information medium substrate having such an increased recording density.

Therefore, as a resin for manufacturing a substrate for an optical information medium, a polycarbonate exhibiting higher transferability than ever has been required. Further, since the thickness of the substrate for CD is 1.2 mm and the thickness of the substrate for DVD is 0.6 mm, there is a demand for polycarbonate having a higher melt fluidity for forming a thin substrate. Is growing. The temperature (about 300 to 320 ° C.) conventionally used for molding the CD substrate using the polycarbonate conventionally used for the production of the CD substrate.
When a DVD substrate is formed by the method described above, the sufficient fluidity cannot be obtained due to insufficient melt fluidity of polycarbonate.

Therefore, a high temperature of 380 to 390 ° C. which cannot be considered in the conventional polycarbonate molding technology (the molding temperature of general polycarbonate is 270 to 300 ° C.).
C., and the molding temperature of the CD substrate is about 320 ° C.), whereby the melt viscosity of the polycarbonate is reduced to mold the DVD substrate. However, in high-temperature molding, there are problems such as heat deterioration of the polycarbonate, a long molding cycle, and large warpage of the molded product. Further, among optical recording media, especially, a demand for a long-term storage recording medium is increasing, and stability under high-temperature and high-humidity conditions is required to enable long-term storage.

Hitherto, polycarbonates produced by the phosgene method have been used for substrates for optical information media. However, polycarbonates produced by the phosgene method have the following disadvantages: (1) using phosgene which is difficult to handle at the time of production; and (2) using methylene chloride as a solvent, chlorine ions and methylene chloride remain as impurities in the polycarbonate. In addition, there are problems such as a decrease in thermal stability during molding due to impurities and corrosion of a mold, and (3) a further decrease in quality of a substrate for an optical information medium.

For this reason, JP-A-63-316313 (corresponding to US Pat. No. 4,880,896), JP-A-4-146922, and JP-A-63-97627 (US Pat. 798,767), and various other documents have proposed many compositions for reducing the above-mentioned impurities and methods for reducing the impurities of polycarbonate. However, in the high-temperature molding as described above, since the conversion of methylene chloride remaining in a trace amount in the polycarbonate during the high-temperature molding into hydrochloric acid increases, the removal of impurities is more complete than the conventional method of reducing impurities. Is desired.

On the other hand, since a great deal of labor is required to completely remove these impurities from the polycarbonate, transesterification polycarbonates that do not use phosgene or methylene chloride have attracted attention in recent years. However, the polycarbonate obtained by the transesterification method has more hydroxyl terminals than the polycarbonate obtained by the phosgene method (see Polymer Analysis Handbook, page 345, published by Asakura Shoten, 1985). During molding, thermal degradation is large and cannot be used for manufacturing substrates for optical information media. At present, there is no excellent transesterification polycarbonate that can be used to manufacture substrates for optical information media, especially substrates for high recording density media such as DVDs that require molding at high temperatures. Is desired.

[0010]

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have substantially produced an aromatic dihydroxy compound and a carbonic acid diester by subjecting them to a transesterification reaction. Is a polycarbonate resin containing no chlorine atom, comprising a plurality of aromatic polycarbonate main chains, wherein the plurality of polycarbonate main chains as a whole have specific hetero-bonding units (A) and (B)
The polycarbonate resin having a specific amount on the polycarbonate main chain and having a weight average molecular weight of 13,000 to 18,000 exhibits high melt fluidity at the time of injection molding. It has excellent optical characteristics such as low birefringence and high transferability (that is, information of a stamper (a mold for forming grooves and pits on a substrate) is accurately transferred), so that a DVD or the like is used. It has been found that a substrate which can be advantageously used as a substrate for an optical information medium having a high recording density can be obtained.

[0011] Further, the present inventors molded a resin composition obtained by adding an acidic compound to the above polycarbonate resin, and even under a high temperature and high humidity condition, a small optical defect (light scattering, light Cut off, about 200μm in diameter
Less craze-like defects) can be obtained. The present invention has been completed based on these findings. Therefore, the present invention
One purpose is to exhibit high melt fluidity at the time of injection molding. Therefore, when used in the production of an optical information medium substrate, it has excellent optical properties such as low birefringence and high transferability (that is, a stamper ( Polycarbonate capable of obtaining a substrate that can be advantageously used as a substrate for an optical information medium having a high recording density, such as a DVD, because information of a mold for forming grooves and pits is accurately transferred onto the substrate. It is to provide a resin.

Another object of the present invention is to provide a polycarbonate resin composition comprising the above polycarbonate resin and an acidic compound. Still another object of the present invention is to provide a substrate for an optical information medium obtained by molding the above polycarbonate resin or the above polycarbonate resin composition. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the appended claims.

[0013]

According to one aspect of the present invention, there is provided a polycarbonate resin substantially free of chlorine atoms, prepared by subjecting an aromatic dihydroxy compound and a carbonic acid diester to a transesterification reaction. And a plurality of aromatic polycarbonate main chains, each aromatic polycarbonate main chain including a plurality of repeating units each independently represented by the following formula (1):

Embedded image (In the formula, Ar represents a divalent C ₅ -C ₂₀₀ aromatic group.)

The plurality of polycarbonate main chains have at least one hetero-linking unit (A) and at least one hetero-linking unit (B) on the polycarbonate main chain as a whole, and the hetero-linking unit (A) is It is represented by the following equation (2),

Embedded image (Wherein, Ar ′ represents a trivalent C ₅ -C ₂₀₀ aromatic group, and X is a group represented by the formula:

[0015]

Embedded image (Wherein, Ar is as described above), and represents a polycarbonate chain having a molecular weight of 214 to 6,000, including a repeating unit represented by the following formula: )

However, when the polycarbonate main chain has a plurality of heterogeneous bonding units (A), the plurality of heterogeneous bonding units (A) may be the same or different. Expression (3)

Embedded image (In the formula, Ar ′ is as described above.)

However, when the polycarbonate main chain has a plurality of heterogeneous bonding units (B), the plurality of heterogeneous bonding units (B) may be the same or different, and X in the above formula (2) represents a heterogeneous unit. It may contain at least one heterogeneous bonding unit selected from the group consisting of the bonding units (A) and (B), and the total amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B) is the repeating unit (1) ) Is in the range of 0.03 to 0.3 mol% with respect to the total molar amount of (A), and the amount of the heterogeneous bonding unit (A) is A polycarbonate resin for producing a substrate for an optical information medium, which is 50 mol% or more and has a weight average molecular weight in a range of 13,000 to 18,000.

Next, in order to facilitate understanding of the present invention,
First, the basic features and preferred embodiments of the present invention will be listed. 1. A substantially chlorine-free polycarbonate resin produced by subjecting an aromatic dihydroxy compound and a carbonic acid diester to a transesterification reaction, comprising a plurality of aromatic polycarbonate main chains, each aromatic polycarbonate The main chain contains a plurality of repeating units each independently represented by the following formula (1),

Embedded image (In the formula, Ar represents a divalent C ₅ -C ₂₀₀ aromatic group.)

The plurality of polycarbonate main chains have at least one heterogeneous bonding unit (A) and at least one heterogeneous bonding unit (B) on the polycarbonate main chain as a whole, and the heterogeneous bonding units (A) It is represented by the following equation (2),

Embedded image (Wherein, Ar ′ represents a trivalent C ₅ -C ₂₀₀ aromatic group;

[0020]

Embedded image (Wherein, Ar is as described above), and represents a polycarbonate chain having a molecular weight of 214 to 6,000, including a repeating unit represented by the following formula: )

However, when the polycarbonate main chain has a plurality of heterogeneous bonding units (A), the plurality of heterogeneous bonding units (A) may be the same or different. Expression (3)

Embedded image (In the formula, Ar ′ is as described above.)

However, when the polycarbonate main chain has a plurality of heterogeneous bonding units (B), the plurality of heterogeneous bonding units (B) may be the same or different, and X in the above formula (2) is a heterogeneous unit. It may contain at least one heterogeneous bonding unit selected from the group consisting of the bonding units (A) and (B), and the total amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B) is the repeating unit (1) ) Is in the range of 0.03 to 0.3 mol% with respect to the total molar amount of (A), and the amount of the heterogeneous bonding unit (A) is A polycarbonate resin for producing a substrate for an optical information medium, which is 50 mol% or more and has a weight average molecular weight in a range of 13,000 to 18,000.

2. Absorption wave number 1740 cm having a particle size of 5 μm or more and measured by infrared absorption spectroscopy
Stretching vibration of carbonyl group contained in a carbonate-type ester bond of the polycarbonate resin in the absorption intensity A ₁ and the absorption wave number 1780 cm ^-1 in the stretching vibration of carbonyl groups contained in the non-carbonate type ester bond the polycarbonate resin in ^-1 Ratio A _{1 to} absorption intensity A ₂
/ A ₂ , heat-degraded particles having a heat-degradation degree of 0.2 or more were added to 20 g of the polycarbonate resin per 100 g.
2. The polycarbonate resin according to the above item 1, wherein the amount of the polycarbonate resin is less than or equal to the number.

3. (1) The amount of the heterogeneous bonding unit (A) is 50 to 95 mol% based on the total molar amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B).
Polycarbonate resin described in 1. 4. 2. The polycarbonate resin according to the above item 1, wherein the amount of terminal hydroxyl groups of the polycarbonate resin is 5 to 50 mol% based on the total molar amount of the terminal groups of the polycarbonate resin.

[5] 85. The polycarbonate resin according to item 1, wherein 85% or more of the repeating unit (1) is represented by the following formula (1 ′).

Embedded image

6. An optical information medium substrate obtained by molding the polycarbonate resin according to the above item 1. 7. (I) Polycarbonate resin 100 according to item 1 above
Parts by weight and (II) acidic compound 0.1 × 10 ⁻⁴ -100
× 10 ^-4 parts by weight of a polycarbonate resin composition for producing a substrate for an optical information medium. 8. An optical information medium substrate obtained by molding the polycarbonate resin composition according to the above item 7.

The polycarbonate resin of the present invention is a polycarbonate resin containing substantially no chlorine atom and produced by subjecting an aromatic dihydroxy compound and a carbonic acid diester to a transesterification reaction. The polycarbonate resin of the present invention is a polycarbonate resin containing a plurality of aromatic polycarbonate main chains, and each aromatic polycarbonate main chain contains a plurality of repeating units each independently represented by the above formula (1). In addition, the plurality of polycarbonate main chains have at least one heterogeneous bonding unit (A) and at least one heterogeneous bonding unit (B) on the polycarbonate main chain as a whole.

The heterogeneous bonding unit (A) is represented by the above formula (2), provided that when the polycarbonate main chain has a plurality of heterogeneous bonding units (A), the plurality of heterogeneous bonding units (A) are the same. The heterogeneous bonding unit (B) may be represented by the above formula (3), provided that the polycarbonate main chain has a plurality of heterogeneous bonding units (B). (B) may be the same or different. In the above equations (1), (2) and (3),
Ar represents a divalent C ₅ -C ₂₀₀ aromatic residue, Ar '
Is one hydrogen atom of the Ar is a trivalent substituted C ₅ -C
_{20 0} aromatic residue. Ar which is a divalent aromatic residue
Is, for example, phenylene, naphthylene, biphenylene,
Pyridylene, -Ar ¹ -Q-Ar ^2- (Ar ¹ and A
r ² is independently ² each having 5 to 70 carbon atoms
Q represents a divalent alkane group having 1 to 30 carbon atoms), and Q represents a divalent carbocyclic or heterocyclic aromatic group.

In the divalent aromatic groups Ar ¹ and Ar ² , at least one hydrogen atom has another substituent which does not adversely influence the reaction, for example, a halogen atom, an alkyl group having 1 to 10 carbon atoms, An alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group,
It may be substituted by an amide group, a nitro group or the like. Preferred specific examples of the heterocyclic aromatic group include an aromatic group having one or more ring-forming nitrogen, oxygen or sulfur atoms. The divalent aromatic groups Ar ¹ and Ar ² represent groups such as substituted or unsubstituted phenylene, substituted or unsubstituted biphenylene, and substituted or unsubstituted pyridylene. The substituent here is as described above.

The divalent alkane group Q is, for example, an organic group represented by the following formula.

Embedded image (Wherein R ¹ , R ² , R ³ and R ⁴ are each independently hydrogen,
C1-C10 alkyl group, C1-C10 alkoxy group, C5-C10 cycloalkyl group, C5-C10 carbocyclic aromatic group, C6-C1
Represents a carbocyclic aralkyl group of 0. k represents an integer of 3 to 11, R ⁵ and R ⁶ are individually selected for each Z, and each independently represents hydrogen or an alkyl group having 1 to 6 carbon atoms, and Z represents carbon. R ¹ , R ² ,
In R ³ , R ⁴ , R ⁵ , and R ⁶ , other substituents such as a halogen atom, an alkyl group having 1 to 10 carbon atoms, and 1 carbon atom may be used as long as one or more hydrogen atoms do not adversely affect the reaction.
It may be substituted by 10 to 10 alkoxy groups, phenyl groups, phenoxy groups, vinyl groups, cyano groups, ester groups, amide groups, nitro groups and the like. )

Specific examples of such a divalent aromatic residue Ar include those represented by the following formula.

Embedded image (Wherein, R ⁷ and R ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 ring carbon atoms, or A phenyl group, m and n are integers of 1 to 4, and when m is 2 to 4, each R ⁷ may be the same or different, and when n is 2 to 4, In the formula, each R ⁸ may be the same or different.)

Further, the divalent aromatic residue Ar may be represented by the following formula. —Ar ¹ —Z′—Ar ² — (wherein, Ar ¹ and Ar ² are as described above, and Z ′ is a single bond or —O—, —CO—, —S—, —SO ₂ —, —SO
—, —COO—, and —CON (R ¹ ) — represent a divalent group. Here, R ¹ is as described above. )

Specific examples of such a divalent aromatic residue Ar include those represented by the following formula.

Embedded image (In the formula, R ⁷ , R ⁸ , m and n are as described above.)

The aromatic residues Ar used in the present invention may be used alone or in combination of two or more. Preferred examples of the repeating unit in the present invention include:
A structural unit derived from bisphenol A represented by the above formula (1 ′) is exemplified. In particular, 85 of the repeating unit (1)
% Or more is preferably a unit represented by the formula (1 ′).

Further, the heterogeneous bonding unit (A) is preferably a structural unit derived from bisphenol A represented by the following formula (2 ').

Embedded image (Where X is as defined in the above formula (2))

It is preferable that the heterogeneous bonding unit (B) is a structural unit derived from bisphenol A represented by the following formula (3 ').

Embedded image

In the present invention, the total amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B) is in the range of 0.03 to 0.3 mol% based on the total molar amount of the repeating unit (1). And preferably in the range of 0.04 to 0.25 mol%, particularly preferably in the range of 0.05 to 0.20 mol%. Further, the amount of the heterogeneous bonding unit (A) is 5 to the total molar amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B).
0 mol% or more, preferably 50 to 99 mol%, more preferably 70 to 97 mol%, particularly preferably 80 to 99 mol%.
95 mol%.

When the amount of the heterogeneous bonding unit (A) is less than the above range, the effect of improving the melt fluidity is small. Therefore, in order to obtain sufficient melt fluidity, it is necessary to use a higher molding temperature, but as described above, if the molding temperature is too high, the thermal degradation of the polycarbonate, the molding cycle becomes longer, Problems such as increased warpage occur. If the amount is larger than the above range, the melt fluidity of the polycarbonate resin is improved, but the mechanical strength of the molded substrate is reduced and optical defects are generated under high temperature and high humidity conditions. The polycarbonate resin of the present invention,
In addition to the above-mentioned heterogeneous bonding units (A) and (B), it may optionally contain the following heterogeneous bonding units.

[0039]

Embedded image (Where Ar, Ar ′ and X are as defined in the above formulas (1) and (2), Ar ″ represents a tetravalent C _{5 to} C ₂₀₀ aromatic group, and Y is Each expression

[0040]

Embedded image (Wherein, Ar is as described above), and represents a polycarbonate chain having a molecular weight of 214 to 6,000, including a repeating unit represented by the following formula: When bisphenol A is used as the aromatic hydroxy compound, it is preferable that the above-mentioned arbitrary hetero-bonding unit is a structural unit shown below.

[0041]

Embedded image (Where X and Y are as described above)

In the present invention, the repeating unit (1) and the hetero-linking units (A) and (B) in the polycarbonate resin are used.
The quantification of the complete hydrolysis of the polycarbonate resin,
The reaction is carried out using reverse-phase liquid chromatography under the conditions described in Examples described later. Hydrolysis of polycarbonate resin
Polymer Degradation and Stability 45 (1994), 127-13
The hydrolysis method at room temperature as described in 7 is preferable because the operation is easy and there is no side reaction in the decomposition process, and the polycarbonate resin can be completely hydrolyzed. When the polycarbonate resin of the present invention contains any of the above-mentioned heterogeneous bonding units, the amount of any of the heterogeneous bonding units can be determined by the same method as described above.

The weight average molecular weight of the polycarbonate resin of the present invention is in the range of 13,000 to 18,000, preferably in the range of 13,000 to 17,000,
More preferably, it is in the range of 13,500 to 16,000. When the weight average molecular weight is larger than the above range, the melt fluidity of the polycarbonate resin is poor, so that it cannot be used for molding a substrate of a high-density optical information medium such as a DVD.
When the weight average molecular weight is smaller than the above range,
The mechanical strength of the information medium substrate obtained by molding becomes insufficient. In the present invention, the weight average molecular weight of the polycarbonate resin is measured using GPC. The measurement conditions are determined using a tetrahydrofuran solvent and a polystyrene gel, and using a reduced molecular weight calibration curve according to the following equation from the configuration curve of the standard monodisperse polystyrene. ^{_{M PC = 0.3591M PS 1.0388 (M}} PC represents the molecular weight of the polycarbonate, M _PS is the molecular weight of the polystyrene.)

The polycarbonate resin of the present invention has a particle size of 5 μm or more and has a carbonyl group contained in a non-carbonate type ester bond in the polycarbonate resin at an absorption wave number of 1740 cm ⁻¹ as measured by infrared absorption spectroscopy. The heat represented by the ratio A ₁ / A ₂ of the absorption intensity A ₁ of the stretching vibration of the polycarbonate resin and the absorption intensity A ₂ of the stretching vibration of the carbonyl group contained in the carbonate type ester bond in the polycarbonate resin at an absorption wave number of 1780 cm ⁻¹ . The amount of thermally degraded particles having a degree of deterioration of 0.2 or more is
The number is preferably 20 or less per 100 g of the polycarbonate resin. The above non-carbonate type ester bond is generated by thermal decomposition of the polycarbonate resin.

The particle size of the thermally degraded product is the maximum diameter of the thermally degraded product particles. It is considered that the thermally degraded particles are generated when the polycarbonate resin is decomposed by heat during production.
If a large amount of thermally degraded particles are present in the polycarbonate resin in a range larger than the above range, the strength of the substrate is reduced when the information medium substrate is molded, which is not preferable. However, when the absorption intensity ratio A ₁ / A ₂ is smaller than 0.2, it is considered that the influence on the substrate strength is small. In infrared absorption spectroscopy, the position of the stretching vibration wavelength has some fluctuations and errors, so the absorption intensity A ₁ is 1740 ± 15 which is the stretching frequency of the carbonyl group contained in the non-carbonate ester bond.
Using the absorption intensity of the peak top appearing in the range of cm ^-1 ,
The absorption intensity A ₂ is 1780 ± 1 which is the stretching frequency of the carbonyl group contained in the carbonate type ester bond.
The absorption intensity at the peak top appearing in the range of 5 cm ^-1 is used.

Further, the polycarbonate resin of the present invention comprises
The amount of terminal hydroxyl groups is preferably 5 to 50 mol% based on the total molar amount of terminal groups of the polycarbonate resin. The amount of terminal hydroxyl groups is more preferably in the range of 10 to 40 mol%, particularly preferably in the range of 15 to 30 mol%. When the amount of terminal hydroxyl groups is less than the above range, it is difficult to obtain a uniform quality information medium substrate, and when the amount is more than the above range, stability during high-temperature molding tends to decrease. The method of measuring the terminal hydroxyl group ratio can be generally determined by direct measurement using NMR, or by calculating from the amount of terminal hydroxyl groups and the total terminal amount obtained by the titanium method, UV or IR method. In the above, the ratio of terminal hydroxyl groups is determined using the following method. Specifically, a polycarbonate resin is dissolved in acetic acid methylene chloride, titanium tetrachloride is added, and the amount of terminal hydroxyl groups is determined by photometrically measuring the generated red complex at 546 nm (that is, the titanium method). It was determined from the number average molecular weight measured by GPC.

The method for producing the polycarbonate resin of the present invention will be described below. As described above, the polycarbonate resin of the present invention is produced by subjecting an aromatic dihydroxy compound and a carbonic acid diester to a transesterification method. In the present invention, the aromatic hydroxy compound is represented by the formula HO—Ar—OH (wherein, Ar is as described above)
It is a compound represented by these. The aromatic dihydroxy compound for producing the polycarbonate resin of the present invention may be used alone or in combination of two or more.

It is preferable that these aromatic dihydroxy compounds have a small content of a chlorine atom and an alkali or alkaline earth metal, and it is preferable that the content is substantially zero if possible. Specifically, the chlorine atom content is preferably 0.5 ppm or less, and the alkali or alkaline earth metal content is preferably 0.1 ppm. The content of chlorine atoms can be measured by ion chromatography, and the content of alkali or alkaline earth metal can be measured by atomic absorption spectrometry.

The carbonic acid diester used for producing the polycarbonate resin of the present invention is represented by the following formula.

Embedded image (Wherein, Ar ³ and Ar ⁴ are each monovalent C ₅ -C ₂₀₀
Represents an aromatic group, which may be the same or different. )

Ar ³ and Ar ^{4 each} represent a monovalent carbocyclic or heterocyclic aromatic group. In Ar ³ and Ar ⁴ , one or more hydrogen atoms have no adverse effect on the reaction. Substituents, for example, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a phenyl group, a phenoxy group, a vinyl group, a cyano group, an ester group,
It may be substituted by an amide group, a nitro group or the like. Representative examples of the monovalent aromatic groups Ar ³ and Ar ⁴ include a phenyl group, a naphthyl group, a biphenyl group, and a pyridyl group. These may be substituted with one or more substituents described above.

Preferred examples of Ar ³ and Ar ⁴ include those represented by the following formulas.

Embedded image

Representative examples of the carbonic acid diester include substituted or unsubstituted diphenyl carbonates represented by the following formula.

Embedded image (Wherein R ⁹ and R ¹⁰ are each independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 10 ring carbon atoms, or a phenyl group) In the formula, p and q are integers of 1 to 5, and when p is 2 or more, each R ⁹ may be different, and when q is 2 or more, each R ¹⁰ is Each may be different.)

Among the diphenyl carbonates,
Unsubstituted diphenyl carbonate and symmetric diaryl carbonates such as lower alkyl-substituted diphenyl carbonates such as ditolyl carbonate and di-t-butylphenyl carbonate are preferred, and diphenyl carbonate which is a diaryl carbonate having the simplest structure is particularly preferred. It is. These carbonic acid diesters may be used alone or in combination of two or more. In addition, it is preferable that these carbonate diesters have a small content of chlorine atom and alkali or alkaline earth metal, and it is preferable that they are substantially not contained if possible.
Specifically, the chlorine atom content is preferably 0.5 ppm or less, and the alkali or alkaline earth metal content is preferably 0.1 ppm. The content of chlorine atoms can be measured by ion chromatography, and the content of alkali or alkaline earth metal can be measured by atomic absorption spectrometry.

The ratio of the aromatic dihydroxy compound and the carbonic acid diester used in the production of the polycarbonate resin of the present invention (the charging ratio) depends on the kind of the aromatic dihydroxy compound and the carbonic acid diester used, the polymerization temperature and other polymerization conditions. There is no particular limitation, depending on the molecular weight and terminal ratio of the polycarbonate to be obtained. Carbonic acid diester is used per mole of aromatic dihydroxy compound.
Usually 0.9 to 2.5 mol, preferably 0.95 to 2.0
Mole, more preferably 0.98 to 1.5 mole. When producing the polycarbonate resin of the present invention, an aromatic monohydroxy compound or an aliphatic alcohol may be used in combination for terminal conversion or molecular weight control.

In the present invention, the transesterification method means that the above compound is subjected to transesterification in a molten state or a solid state while heating under reduced pressure and / or inert gas flow in the presence or absence of a catalyst. Means polycondensation. There are no restrictions on the polymerization method by transesterification, the equipment used, and the like. For example, a stirred tank reactor, a thin film reactor, a centrifugal thin film evaporation reactor, a surface-renewal twin-screw kneading reactor, a twin-screw horizontal stirring reactor, a wet-wall reactor, and a perforated plate that allows free-fall polymerization It can be easily produced by using a reactor, a wire contact falling type polymerization reactor which polymerizes while being dropped along a wire, or the like, alone or in combination. Alternatively, after the prepolymer is produced by performing a transesterification reaction in a molten state, it can be produced by a solid phase polymerization method in which the degree of polymerization is increased in a solid state under reduced pressure and / or an inert gas flow. Further, there is no particular limitation on the material of these reactors, the material constituting at least the inner wall surface of the reactor,
Usually selected from stainless steel, nickel, glass and the like.

As a specific method for producing the polycarbonate resin of the present invention having specific amounts of the specific hetero-bonding units (A) and (B) on the polycarbonate main chain, a method for producing the polycarbonate resin by transesterification is as follows. A method of adding a specific dihydroxy compound, a trifunctional compound or a polyfunctional compound to form a heterogeneous bonding unit represented by the formula (2) or (3) to introduce a heterogeneous bonding unit; A method of generating a heterogeneous bonding unit in the polymerization process and introducing it into the polycarbonate main chain by selecting production conditions such as a polymerization temperature, a catalyst, and a residence time without using the same; and a method of using both in combination.

In the present invention, the production conditions are controlled because the occurrence of optical defects under high-temperature and high-humidity conditions is small, and a polycarbonate resin having excellent balance between mechanical properties and low-temperature moldability can be easily obtained. In this case, a method of generating a heterogeneous structure in the polymerization process and introducing it into a polycarbonate resin is preferably used. Generally, when a polycarbonate resin is produced by a transesterification method, an aromatic dihydroxy compound is subjected to the action of an alkali to form Kolbe-Sc.
It is known that a reaction similar to the hmitt reaction produces a heterogeneous binding unit represented by the following formula (α).

[0058]

Embedded image

However, by controlling the reaction conditions, the heterogeneous bond unit represented by the formula (2) and the heterogeneous bond unit (A) represented by the formula (3) are hardly generated. The heterogeneous binding unit (B) can be controlled and introduced. As a method for producing the polycarbonate resin of the present invention by controlling the reaction conditions, it is preferable to use the production method described in International Publication No. WO97-32916. As described in the above publication, the method for introducing the heterogeneous bonding units (A) and (B) into the polycarbonate main chain is performed by controlling the relationship between the temperature and the time during the production of the polycarbonate resin.

The amount of the heterogeneous units (A) and (B) introduced into the polycarbonate resin is determined by the amount of the polymerization raw material (the molten mixture of the aromatic dihydroxy compound and the carbonic acid diester and / or the aromatic dihydroxy compound) during the polymerization reaction. The higher the temperature, the higher the amount of molten prepolymer obtained by a process involving reacting with a carbonic acid diester), and the higher the temperature, the higher the amount of the heterogeneous unit (B) to be introduced. Therefore, by controlling the relationship between the temperature of the polymerization raw material and the residence time, it is possible to introduce a desired amount of the heterogeneous bonding unit into the polycarbonate resin. In the present invention, in the technology described in the above-mentioned publication, the polycarbonate having the above specific amounts of the heterogeneous bonding units (A) and (B) is more strictly controlled by more strictly controlling the relationship between temperature and time during the production of the polycarbonate resin. Resin can be manufactured.

More specifically, at least one selected from the group consisting of a molten mixture of an aromatic dihydroxy compound and a carbonic acid diester and a molten prepolymer obtained by a process comprising reacting the aromatic dihydroxy compound with a carbonic acid diester. In a method for producing a polycarbonate resin, which comprises subjecting a polymerization raw material of the above to a stepwise transesterification reaction in a plurality of reaction zones, the stepwise transesterification reaction of the polymerization raw material is carried out under a reaction condition satisfying the following formula (4). It is preferable to use a method for performing the method.

(Equation 1)

I: reaction zone number assigned to a plurality of reaction zones in the reaction system in an arbitrary order; Ti: average temperature (° C.) of the polymerization raw material in the i-th reaction zone; Average residence time (hr) ki: coefficient represented by the following equation: ki = 1 / aTi- ^b (5) where Ti is as described above, a and b depend on Ti, and when Ti <240 ° C. a = 1.60046 × 10 ⁵ b = 0.472, when 240 ° C. ≦ Ti <260 ° C., a = 4 × 10 ⁴⁹ b = 19.107, and when 260 ° C. ≦ Ti, a = 1 × 10 ¹²² b = 49.082.

[0063]

(Equation 2) Is preferably in the range from 0.3 to 1.1, particularly preferably in the range from 0.4 to 1.0.

In the continuous production of a polycarbonate resin by the transesterification method, it is general that a stepwise transesterification reaction of the polymerization raw material is performed in a plurality of reaction zones, and the temperature, residence time and reaction pressure are changed stepwise.
Equation (4) shows the sum of k × T × H in the reaction zone,
For example, in the case of dissolving and mixing an aromatic dihydroxy compound and a carbonic acid diester, a stirring tank type reactor, a centrifugal thin film evaporation reactor and a surface renewal type twin screw kneading reactor for continuous polymerization.

(Equation 3) Is (k × T × H in the dissolution / mixing tank) + (k × T × H in the piping from the dissolution / mixing tank to the stirred tank reactor) + (k × T × H in the stirred tank reactor) ) + (K × T × H of piping from stirred tank reactor to centrifugal thin film evaporation reactor) + (k × T × H in centrifugal thin film evaporation reactor) + (from centrifugal thin film evaporation reactor K × T of piping to surface renewal type twin screw kneading reactor
× H) + (k × T × H in a surface renewal type twin-screw kneading reactor)
+ (K × T × H of the pipe from the surface-renewal type twin-screw kneading reactor to the extraction nozzle) indicates the total sum in all reaction zones including the pipe.

In this case, the i-th reaction zone refers to each stage and each step of each mixing tank, each reactor, and a pipe connecting them. When there is a heater in the middle of the pipe connecting the reactors, the pipe between the reactor and the heater, the heater, and the pipe between the heater and the reactor are each an i-th reaction zone. The average temperature of the polycarbonate resin refers to the average value of the temperature in the i-th reaction zone. If the temperature is clearly divided into several stages, the temperature is divided into the respective stages, and each of the stages is defined as the i-th reaction zone. The average temperature at the stage may be used. For the measurement of the average temperature, the temperature of one or more thermometers installed in the reactor or the piping may be averaged, or when no thermometer is installed, the temperature of the heating medium in the jacket is used. Is also good. Alternatively, an average value of the temperature at the entrance and exit of the jacket may be used. A set temperature of a heater or a heat medium may be used. The average residence time is calculated as: polycarbonate retained in each i-th reaction zone / throughput or withdrawal per hour.

The reaction pressure used for producing the polycarbonate resin of the present invention is preferably selected from the range of normal pressure to a pressure lower by 1 mmHg or more, and varies depending on the reaction zone. In the system used for the polymerization reaction, the reaction pressure in the polymerization reactor for performing the reaction in the final stage is 5
mmHg or less is preferable, and 3 mmHg or less is particularly preferably used.

The polymerization by the transesterification method is carried out by using a catalyst.
Can be carried out without the addition of
If desired, the reaction is carried out in the presence of a catalyst. As a polymerization catalyst
Are particularly limited if they are used in this field
But not lithium hydroxide, sodium hydroxide, hydroxide
Alkali metals such as potassium and calcium hydroxide
Hydroxides of alkaline earth metals; aluminum hydride
, Sodium borohydride, tetraboromide
Hydrogenation of boron and aluminum such as tyl ammonium
Alkali metal salts, alkaline earth metal salts, quaternary anions
Monium salts; lithium hydride, sodium hydride, water
Alkali metals such as calcium iodide and alkaline earth gold
Genus hydrogen compounds: lithium methoxide, sodium methoxide
Alkali metals such as toxide and calcium methoxide
Alkoxides of alkaline earth metals; lithium pheno
Oxide, sodium phenoxide, magnesium pheno
Oxide, LiO-Ar-OLi, NaO-Ar-ONa
Alkali metals such as (Ar is an arylene group)
Aryloxides of lithium earth metals; lithium acetate, potassium acetate
Alkali metals such as lucium and sodium benzoate;
Organic acid salts of alkaline earth metals; zinc oxide, zinc acetate,
Zinc compounds such as zinc phenoxide; boron oxide,
Boric acid, sodium borate, trimethyl borate, boric acid
Libutyl, triphenyl borate, (R¹R^TwoR^ThreeR^Four)
NB (R¹R^TwoR^ThreeR^Four) Or (R ¹R^TwoR^ThreeR^Four)
PB (R¹R^TwoR^ThreeR^FourAmmonium bore represented by)
Or phosphonium borates (R¹, R^Two, R
^Three, R^FourAre boron compounds such as described above);
Silicon oxide, sodium silicate, tetraalkylsilicone
Element, tetraaryl silicon, diphenyl-ethyl-ethy
Compounds of silicon such as silicon oxide; germanium oxide
System, germanium tetrachloride, germanium ethoxide,
Germanium compounds such as rumanium phenoxide
Class: tin oxide, dialkyltin oxide, dialkyls
Dicarboxylate, tin acetate, ethyltin tributary
Bonds with alkoxy or aryloxy groups such as sides
Tin compounds such as tin compounds and organotin compounds;
Lead oxide, lead acetate, lead carbonate, basic carbonate, lead and organic lead
Of lead such as alkoxide or aryloxide of
Quaternary ammonium salt, quaternary phosphonium salt, quaternary
Onium compounds such as quaternary arsonium salts;
Antimony compounds such as thymon and antimony acetate;
Manganese acetate, manganese carbonate, manganese borate, etc.
Ngan compounds; titanium oxide, titanium alkoxide
Or compounds of titanium such as aryloxide;
Ruconium, zirconium oxide, zirconium alco
Oxide or aryloxide, zirconium acetylacetate
Catalysts such as compounds of zirconium such as tons
Can do things.

When using a catalyst, these catalysts may be used alone or in combination of two or more. The amount of these catalysts to be used is generally 10 ^-8 to 1% by weight, preferably 10 ^-7 to 10 ^-1 % by weight, particularly preferably 10 ^-6 , based on the aromatic dihydroxy compound as the raw material.
It is selected in the range of 10 to ² % by weight. The polycarbonate resin of the present invention is a polycarbonate resin containing substantially no chlorine atom. Specifically, in the method of measuring chloride ion by potentiometric titration using silver nitrate solution or ion chromatography, the amount of chlorine ion is 0.5 ppm or less, and at the same time, the method of measuring chlorine atom by combustion method, Is below the detection limit of 10 ppm. Preferably, the amount of chloride ion obtained by the method is 0.1 ppm or less below the detection limit of the above measurement method, and at the same time,
Is 10 ppm or less. In the transesterification method, when a polycarbonate resin is produced from an aromatic dihydroxy compound containing substantially no chlorine atom and a carbonic acid diester, unless the other chlorine-containing compound is added, the obtained polycarbonate resin is used. The resin contains substantially no chlorine atoms.

In another embodiment of the present invention,
(I) 100 parts by weight of the polycarbonate resin of the present invention,
(II) 0.1 × 10 ^{−4 to} 100 × 10 ⁻⁴ parts by weight of an acidic compound. In general, it is known that when an acidic compound is added to a polycarbonate resin, hydrolysis of the polycarbonate resin is accelerated, which tends to increase cloudiness. Cloudiness is a phenomenon in which light is scattered and looks white due to scattering, and is one of optical defects. In the study of the present inventors, a polycarbonate composition obtained by adding an acidic compound to a polycarbonate resin having a weight average molecular weight of about 23,000 to 26,000 generally used for injection molding was molded. When a molded product having a thickness of about 3 mm obtained and subjected to a steam resistance test at 120 ° C., the molded product was significantly clouded as compared with a molded product composed of only a polycarbonate resin (that is, without an acidic compound added). Therefore, it is a very surprising finding that the addition of an acidic compound to the polycarbonate resin of the present invention significantly reduced the optical defects of the polycarbonate resin composition under high temperature and high humidity conditions.

The acidic compound contained in the polycarbonate resin composition of the present invention is not particularly limited, but does not include phenols by-produced in the polycarbonate resin production process. As the acidic compound, a compound having a pKa of 5 or less (solvent: water, or a mixed solvent of water and methanol) is preferable,
For example, phosphoric acid, phosphorous acid, hypophosphorous acid, pyrophosphoric acid,
Inorganic acids such as boric acid, organic acids such as adipic acid, citric acid, and acetic acid; sulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid; ethylbenzenebenzene;
Examples thereof include sulfonic esters such as butyl toluenesulfonate, and phosphoric acid, citric acid, and sulfonic esters are particularly preferably used.

The amount of the acidic compound contained in the resin composition of the present invention is in the range of 0.1 × 10 ^-4 parts by weight to 100 × 10 ^-4 parts by weight, preferably 100 parts by weight of the polycarbonate resin. 0.4 × 10 ⁻⁴ to 50 × 10 ⁻⁴ parts by weight, particularly preferably 0.8 × 10 ^{−4 to} 20 × 10 ⁻⁴ parts by weight.
× 10 ^-4 parts by weight. If the amount of the acidic compound contained in the resin composition is out of the above range, when a substrate for an optical information medium obtained by molding such a resin composition is subjected to high-temperature and high-humidity conditions, micro optical defects may occur. It is not preferable because it occurs. As a method for producing the polycarbonate resin composition of the present invention, an acidic compound may be added to a polycarbonate resin in a molten state immediately after production, or may be added to a pelletized polycarbonate resin and melt-kneaded. . In addition, the content of the acidic compound, NMR, atomic absorption,
It can be quantified by ordinary analytical means such as liquid chromatography.

Further, the resin composition of the present invention may be used in conventional techniques such as a heat stabilizer, an antioxidant, a weathering agent, an ultraviolet absorber, a release agent, a lubricant, an antistatic agent and a plasticizer, if necessary. Additives may be included in the amounts used in the prior art. Such an additive may be added to a polycarbonate resin in a molten state immediately after production, or may be added to a pelletized polycarbonate resin and melt-kneaded. In still another aspect of the present invention, there is provided an optical information medium substrate obtained by molding the polycarbonate resin or the polycarbonate resin composition of the present invention.

In the present invention, the optical information medium substrate is
It refers to a substrate used for an optical information medium in which information can be optically written or read using fine bits or grooves formed on the substrate. Specific examples of the optical information medium include CD, MD, CD-ROM, CD-R, and CD-R.
W, DVD-ROM, DVD-R, DVD-RW, M
D, MO and the like. The method for molding the optical information medium substrate of the present invention is not particularly limited. For example, it can be manufactured by a method including the following steps (1) to (3). (1) The above-described polycarbonate resin of the present invention or the above-described polycarbonate resin composition of the present invention is manufactured. (2) The obtained polycarbonate resin or polycarbonate resin composition is introduced into an injection molding machine for manufacturing an optical disk, 3) Polycarbonate resin or polycarbonate resin composition is molded at a temperature of 300 to 370 ° C and a mold temperature of 50 to 1
Injection molding is performed under the conditions of 30 ° C. and a molding cycle of 3 to 10 seconds.

As an injection molding machine for manufacturing an optical disk, a conventionally used injection molding machine can be used. The optical information medium substrate of the present invention has high transferability (that is, information of a stamper (a mold for forming grooves and pits on the substrate) is accurately transferred) and low birefringence. In addition, it is suitable for long-term use because it has few optical defects which are defects in reading and writing of information and has excellent mechanical strength and heat and moisture resistance.

[0075]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples and comparative examples, but these do not limit the present invention. In Examples and Comparative Examples, various characteristics were measured by the following methods. Weight average molecular weight Gel permeation chromatography (GPC) was performed under the following measurement conditions. GPC was carried out using a tetrahydrofuran solvent and a polystyrene gel, and the molecular weight of the polycarbonate resin was determined from the constitution curve of the standard monodisperse polystyrene based on the converted molecular weight calibration curve of the following formula. ^{_{M PC = 0.3591M PS 1.0388 (M}} PC represents the molecular weight of the polycarbonate resin, M _PS is the molecular weight of the polystyrene.)

Determination of Repeating Unit (1) and Heterolinking Units (A) and (B) 55 mg of a polycarbonate resin was added to tetrahydrofuran 2
After dissolving in 5 ml, 0.5 ml of 5N methanolic potassium hydroxide solution was added, and the mixture was stirred at room temperature for 2 hours to completely hydrolyze. Thereafter, 0.3 ml of concentrated hydrochloric acid was added, and each binding unit was measured by reverse phase liquid chromatography. Reversed-phase liquid chromatography uses 991 as a UV detector.
L-type machine (Waters, USA), Inertsil
ODS-3 column (registered trademark: manufactured by GL Sciences Inc.), using a mixed eluent composed of methanol and a 0.1% phosphoric acid aqueous solution as an eluent, using a column temperature of 25 ° C. and a methanol / 0.1% phosphoric acid aqueous solution ratio The measurement was performed under the conditions starting from 20/80 and a gradient from 100/0 to 100/0. Detection was performed at a wavelength of 300 nm and quantified from the extinction coefficient of the standard substance. [As the standard substance, the above formula (1 ′)-
A hydroxy compound corresponding to the structure obtained by hydrolyzing the bonding unit of (3 ′) and a hydroxy compound whose carboxyl group was methylated were used. ]

Determination of Thermal Degradation Particles 100 g of a polycarbonate resin was dissolved in 2 liters of methylene chloride and suction-filtered with a 1 μm Teflon (registered trademark) filter. Thereafter, the polycarbonate resin adhering to the filter was washed away with 1 liter of methylene chloride. The particle size of the thermally degraded particles remaining on the filter is measured, and the particles having a particle size of 5 μm or more are taken out with a micromanipulator (Micro Manipulator System: manufactured by Shimadzu Corporation), and the obtained thermally degraded particles having a particle size of 5 μm or more are obtained. In each case, the absorption intensity A ₁ due to the stretching vibration of the carbonyl group contained in the non-carbonate type ester bond in the polycarbonate resin (generated by the thermal decomposition of the polycarbonate resin) at an absorption wave number of 1740 cm ⁻¹ , The ratio A ₁ / to the absorption intensity A ₂ due to stretching vibration of the carbonyl group contained in the carbonate type ester bond in the polycarbonate resin at a wave number of 1780 cm ^-1 .
I was asked to A _2. KBr (potassium bromide)
Crush on the infrared crystal plate to a thickness of 2 μm or less, and
R (Fourier-Transform Infrared Micro-Spectromete
r) (FTS 575C / UMA500 System: Nippon BIO, Japan
-RAD Labotatories) by a transmission method. Based on the obtained spectrum was determined A ₁ / A _2.
The value of A ₁ / A ₂ was defined as the degree of thermal deterioration, and the number of thermally deteriorated particles having a degree of thermal deterioration of 0.2 or more was determined.

Amount of terminal hydroxyl group 0.4 g of polycarbonate resin was added to 50 ml of methylene chloride.
To give a solution. 10 ml of the obtained solution was
After dispensing into a 0 ml sample bottle, adding 12 ml of methylene chloride and mixing well, 2 ml of titanium tetrachloride and 1 m of acetic acid were added.
was added, and the sample bottle was shaken and stirred to obtain a measurement sample. Spectrophotometer (Spectrophotometer MPS
-2000; manufactured by Shimadzu Corporation of Japan) to measure the amount of terminal hydroxyl groups by measuring the absorption intensity at 546 nm of the measurement sample. All measurements of absorption intensity were performed under nitrogen to avoid moisture absorption. The amount of terminal hydroxyl groups based on the total molar amount of terminal groups of the polycarbonate resin is determined by GPC
Calculated using the number average molecular weight measured in the above.

Evaluation of Moldability of Polycarbonate Resin or Polycarbonate Resin Composition Injection molding machine for optical disks manufactured by Nippon Steel Works (J35EL II-D)
Using K), a 0.6 mm-thick DVD disk substrate was molded from a polycarbonate resin or a polycarbonate resin composition under the conditions of a molding temperature of 370 ° C. or 390 ° C. and a mold temperature of 120 ° C. The evaluation of the birefringence and transferability of the substrate was performed using a disk performance evaluation machine (PROmeteus: Dr., Germany).
Schenk). The birefringence (nm) indicates the difference between the maximum value and the minimum value of the refractive index measured in the radial direction of the disk substrate. 20nm birefringence for DVD substrate
It is desirable that: The transferability was calculated from the average groove depth (D ₁ ) at a position 50 mm from the center of the disc and the groove depth (D ₂ ) of the stamper using the following formula: transferability (%) = (D ₁ / D ₂ ) × 100 It is desirable for the substrate for DVD to exhibit a transferability of 95% or more.

Moisture and Heat Resistance Three DVD disk substrates obtained by molding a polycarbonate resin at 370 ° C. in the same manner as in the above-described evaluation of moldability were subjected to 150 hours at 90 ° C. and 90% relative humidity. The length generated on the disk substrate by leaving
The presence or absence of a craze-like optical defect of μm or more was visually evaluated using a magnifying lens. The case where there was no optical defect described above was evaluated as ○, and the case where it occurred occurred was evaluated as ×. Further, three DVD disk substrates obtained by molding the polycarbonate resin composition at 370 ° C. in the same manner as the molding method in the above-mentioned evaluation of the moldability were subjected to the conditions of 110 ° C. and 90% relative humidity.
It was left for 50 hours and evaluated for craze-like optical defects generated on the disk substrate. Specifically, the number of optical defects of 200 μm or more and 200 μm
The number of micro-optical defects less than each was measured.

Substrate Strength Using 10 DVD disk substrates obtained by molding a polycarbonate resin or a polycarbonate resin composition at 370 ° C. in the same manner as the molding method in the above-mentioned evaluation of moldability, the distance between fulcrums was set to 40 mm. The bending test was performed at a speed of 2 mm / sec. When five or more DVD disks were broken before the bending strength reached the yield point, x: 1 to 4 D
The case where the VD disk was broken was evaluated as Δ, and the case where none of the VD disks was broken was evaluated as ○.

[0082]

Example 1 A stirred tank type first polymerization vessel (A) and (B), a stirred tank type second polymerization vessel, a stirred tank type third polymerization vessel, and 45 wires each having a length of 8 m and a diameter of 1.2 mm. Using a system in which a wire-contacting-flow-type first polymerization device and a wire-contacting-flow-type second polymerization device having 45 wires each having a length of 8 m and a diameter of 1.2 mm are connected by pipes, polycarbonate is produced by a melt transesterification method. A resin was manufactured. A polymerization raw material comprising bisphenol A as an aromatic dihydroxy compound, diphenyl carbonate as a carbonic acid diester (a molar ratio to bisphenol A 1.10) and a disodium salt of bisphenol A (a molar ratio to bisphenol A 8 × 10 ⁻⁸ ) was used. The first stirred polymerization step is performed by alternately using a stirred tank type first polymerization vessel (A) and (B) having a volume of 100 liters and performing melt polymerization at 180 ° C. and normal pressure.
Prepolymer 1 was obtained.

The obtained preprimer 1 was supplied to a 50-liter stirred tank type second polymerization vessel at a rate of 8 kg / hr, and a second stirring polymerization step was carried out at 230 ° C. and 100 mmHg. I got The obtained prepolymer 2 was continuously supplied to a 50-liter stirred tank type third polymerization vessel. In the stirred tank type third polymerization vessel, the third stirred polymerization step was performed under the conditions of 240 ° C. and 20 mmHg to obtain Prepolymer 3. Prepolymer 3 obtained
Was continuously supplied to a wire-contacting-flow-type first polymerization vessel having 45 wires each having a length of 8 m and a diameter of 1.2 mm.
In the first polymerization reactor of the wire contact falling type, 265 ° C.
The first wire contact falling polymerization step was performed under the condition of 3 mmHg to obtain a prepolymer 4.

The obtained prepolymer 4 was continuously supplied to a wire-contact-flow-type second polymerization reactor having 45 wires each having a length of 8 m and a diameter of 1.2 mm. In the wire-contact-flow-type second polymerization vessel, a second wire-contact-flow-type polymerization step was performed under the conditions of 265 ° C. and 0.5 mmHg to obtain a polycarbonate resin. The obtained polycarbonate resin was connected to a polymerization system in series with a twin-screw extruder (P
CM30: Ikegai Iron Works, Japan) (Temperature: 250 ° C)
To obtain polycarbonate resin pellets.

The temperature, residence time, and (ki × Ti) in each stirring type polymerization reactor, each wire contact falling polymerization reactor, each pipe
× Hi) are shown in Table 1. Also

(Equation 4) Are also shown in Table 1.

Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 7 shows the evaluation results. Further, a DVD substrate was molded by the above method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the results. As apparent from Table 8, the polycarbonate resin had good moldability even at 370 ° C. Specifically, as shown in Table 10, the substrate for DVD obtained by molding this polycarbonate resin
% Transferability and good birefringence. Furthermore, the above-mentioned DVD substrate was excellent also in heat and humidity resistance and substrate strength.

[0087]

Example 2 Example 2 was repeated except that a polymerization raw material comprising bisphenol A and diphenyl carbonate (molar ratio of bisphenol A to 1.15) was supplied to the second polymerization vessel of the stirred tank type at a rate of 4.8 kg / hr. The polymerization step was continuously performed in the same manner as in Example 1 to obtain a polycarbonate resin. However, one flange between the wire-contact-flow-type first polymerization vessel and the wire-contact-flow-type second polymerization vessel was heated to 290 ° C. Table 2 shows the reaction conditions. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 7 shows the evaluation results.

Further, a DVD substrate was molded by the above method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the evaluation results. As apparent from Table 8, the polycarbonate resin had good moldability even at 370 ° C. Specifically, in the DVD substrate obtained by molding the polycarbonate resin, although one of the ten substrates cracked during the measurement of the substrate strength,
As shown in Table 8, it had 100% transferability and good birefringence, and was also excellent in wet heat resistance.

[0089]

[Comparative Example 1] Prepolymer 1 was placed in a stirring tank type second polymerization vessel.
The mixture was supplied at a rate of 0.0 kg / hr, the first wire contact falling polymerization step was performed at 250 ° C. under a pressure of 6.3 mmHg, and the second wire contact falling polymerization step was performed at 280 ° C. The amount of the prepolymer or the polymer in the second and third polymerization reactors and the first and second polymerization reactors of the wire-contact flow-down type was respectively 1 / the amount of the retention in Example 1.
Except having changed it into 2, the polymerization process was performed continuously like Example 1, and the polycarbonate resin was obtained. Table 3 shows the reaction conditions. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 7 shows the evaluation results.

Further, a DVD substrate was molded by the above-mentioned method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the evaluation results. As is apparent from Table 8, the amount of the heterogeneous bonding unit (A) was 50% based on the total molar amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B).
When a substrate for DVD was molded at 370 ° C. using the polycarbonate resin of Comparative Example 1 which was less than mol%, a substrate for DVD having sufficient transferability could not be obtained. DVD at a high temperature of 390 ° C to obtain sufficient transferability
When the substrate was molded, a streak-like defect phenomenon that could be detected through the polarizing plate was observed on the disk. It is considered that this defective phenomenon occurred because the molecular weight of the polycarbonate resin decreased due to thermal deterioration and leaked from the nozzle of the injection molding machine. Further, when the heat and humidity resistance was tested at 90 ° C., many optical defects occurred.

[0091]

Comparative Example 2 A polymerization raw material comprising bisphenol A and diphenyl carbonate (a molar ratio to bisphenol A 1.06) was supplied to a second stirred tank-type polymerization vessel at a rate of 12 kg / hr, and a third stirred polymerization step was carried out. 240 ° C, 20mmHg
And the first wire contact falling polymerization step
Performed at 50 ° C. and 0.5 mmHg, the second wire contact falling polymerization step was performed at 250 ° C. and 0.2 mmHg, and stirred tank type second and third polymerization vessels, and wire contact falling polymerization The polymerization process was continuously carried out in the same manner as in Example 1 except that the amount of the prepolymer or the polymer in each of the first and second polymerization reactors was reduced to の of the amount of the polymer in Example 1, respectively, to obtain a polycarbonate resin. Table 4 shows the reaction conditions.

Various properties of the obtained polycarbonate resin were evaluated in accordance with the above methods. Table 7 shows the evaluation results. Further, a DVD substrate was molded by the above method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the evaluation results. At 370 ° C. using the polycarbonate resin of Comparative Example 2 in which the total amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B) is less than 0.03 mol% based on the total molar amount of the repeating unit (1). When a DVD substrate was molded, sufficient transferability could not be obtained. Therefore, when the DVD substrate was molded at 390 ° C., a streak-like defect phenomenon that could be detected through the polarizing plate was found on the disk.

[0093]

Comparative Example 3 A polymerization process was continuously performed in the same manner as in Example 1 except that the same polymerization raw material as in Example 1 was supplied to the second polymerization vessel with a stirring tank at a rate of 2.1 kg / hr. I got Table 5 shows the reaction conditions. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 7 shows the evaluation results. Furthermore, a DVD substrate was molded using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the evaluation results.

As is apparent from Table 8, the total amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B) contained in the polycarbonate resin was 0.30 mol based on the total molar amount of the repeating unit (1). % Of the polycarbonate resin of Comparative Example 3 at 370 ° C., the molding of the substrate could be performed without any problem. However, although the obtained DVD substrate showed good transferability, an optical defect occurred in the wet heat resistance test. Further, the substrate strength was low, and cracks occurred in the substrate in the bending test.

[0095]

COMPARATIVE EXAMPLE 4 Using a polymerization raw material comprising bisphenol A and diphenyl carbonate (molar ratio of bisphenol A to 1.12), a second wire contact falling polymerization step was carried out in 0.
A polymerization step was continuously performed in the same manner as in Example 1 except that the reaction was performed under a pressure of 3 mmHg (that is, the reaction temperature and the residence time were the same as those in Table 1) to obtain a polycarbonate resin. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 7 shows the evaluation results.

Further, a DVD substrate was molded by the above-mentioned method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the evaluation results. As is clear from Table 8, when a DVD substrate was molded at 370 ° C. using the polycarbonate resin of Comparative Example 4 having a weight average molecular weight exceeding 18,000, a DVD substrate having sufficient transferability was obtained. could not. When a DVD substrate was molded at a high temperature of 390 ° C. to obtain sufficient transferability,
A streak-like defect phenomenon that can be detected through the polarizing plate was observed on the disk.

[0097]

Comparative Example 5 A second wire contact falling polymerization step was carried out using a polymerization raw material comprising bisphenol A and diphenyl carbonate (a molar ratio of bisphenol A to 1.12).
A polymerization step was continuously performed in the same manner as in Example 1 except that the reaction was performed under a pressure of 8 mmHg (that is, the reaction temperature and the residence time were the same as those in Table 1) to obtain a polycarbonate resin. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 7 shows the evaluation results.

Further, a DVD substrate was molded by the above-mentioned method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the evaluation results. As is clear from Table 8, a DVD was obtained at 370 ° C. using the polycarbonate resin of Comparative Example 5 having a weight average molecular weight of less than 13,000.
When the substrate was molded, a problem that the sprue could not come off from the mold during molding occasionally occurred, and a good disk substrate could not be obtained. In addition, the disk substrate that could be manufactured without any trouble was cracked in the bending test.

[0099]

COMPARATIVE EXAMPLE 6 Bisphenol A and 2- (3-carboxy-4-hydroxyphenyl) -2- (4'-hydroxyphenyl) propane (molar ratio to bisphenol A 0.002) as an aromatic dihydroxy compound and carbonic acid diester The prepolymer 1 was supplied to the second stirred polymerization reactor at a rate of 12 kg / hr using a polymerization raw material consisting of diphenyl carbonate (bisphenol A molar ratio to bisphenol A: 1.05), and the third stirred polymerization step was performed at 230 ° C. 10mmHg
And the first wire contact falling polymerization step
The polymerization step was continuously performed in the same manner as in Example 1 except that the polymerization step was performed under the conditions of 40 ° C. and 0.3 mmHg, and the second wire contact falling polymerization step was performed under the conditions of 240 ° C. and 0.1 mmHg. A resin was obtained. The obtained polycarbonate resin was supplied to a twin-screw extruder at 300 ° C. to obtain polycarbonate resin pellets. Table 6 shows the reaction conditions.

Various properties of the obtained polycarbonate resin were evaluated in accordance with the above methods. Table 7 shows the evaluation results. Further, a DVD substrate was molded by the above method using the obtained polycarbonate resin, and the substrate characteristics were evaluated. Table 8 shows the results. As is clear from Table 8, when the DVD substrate was molded at 370 ° C. using the polycarbonate resin of Comparative Example 6 containing no heterogeneous bonding unit (B), the birefringence and transferability were good. The heat and humidity resistance was low, and optical defects occurred in the heat and moisture resistance test. Further, the substrate strength was low, and cracks occurred in the substrate in the bending test.

[0101]

[Table 1]

[0102]

[Table 2]

[0103]

[Table 3]

[0104]

[Table 4]

[0105]

[Table 5]

[0106]

[Table 6]

[0107]

[Table 7]

[0108]

[Table 8]

[0109]

Example 3 A polycarbonate resin was synthesized by conducting a polymerization reaction in the same manner as in Example 1, and when the polycarbonate resin was supplied to the twin-screw extruder in the same manner as in Example 1, 1.0 × 10 ^{− By} supplying ⁴ parts by weight of butyl p-toluenesulfonate to the extruder, a polycarbonate resin composition was obtained. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 9 shows the evaluation results. Further, a DVD substrate was molded using the obtained polycarbonate resin composition by the above method, and the substrate characteristics were evaluated. Table 10 shows the evaluation results. As is clear from Table 10, the polycarbonate resin composition was heated at 370 ° C.
However, it had good moldability. Specifically, the DVD substrate obtained by molding this polycarbonate resin composition exhibited 100% transferability as shown in Table 10, and also had good birefringence. Furthermore, it was excellent in heat and humidity resistance and substrate strength.

[0110]

Example 4 A polycarbonate resin composition containing an acidic compound was obtained in the same manner as in Example 3 except that a polycarbonate resin polymerized in the same manner as in Example 2 was used. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 9 shows the evaluation results. Further, a DVD substrate was molded using the obtained polycarbonate resin composition by the above method, and the substrate characteristics were evaluated. Table 10 shows the evaluation results. As is clear from Table 10, the polycarbonate resin composition had good moldability even at 370 ° C. Specifically, in the DVD substrate obtained by molding this polycarbonate resin, one of the ten substrates cracked during the measurement of the substrate strength, but as shown in Table 10, 100% of the substrate was cracked. It had transferability and good birefringence, and was also excellent in wet heat resistance.

[0111]

Comparative Examples 7 to 11 A polycarbonate resin composition containing an acidic compound was obtained in the same manner as in Example 3 except that polycarbonate resins polymerized in the same manner as in Comparative Examples 1 to 5 were used. Various properties of the obtained polycarbonate resin composition were evaluated in accordance with the above methods. Table 9 shows the evaluation results. Further, a DVD substrate was molded using the obtained polycarbonate resin composition by the above method, and the substrate characteristics were evaluated. Table 10 shows the evaluation results.

As apparent from Table 10, the amount of the heterogeneous bonding unit (A) contained in the polycarbonate resin is less than 50 mol% based on the total molar amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B). The total amount of the heterogeneous bonding units (A) and the heterogeneous bonding units (B) contained in the polycarbonate resin is 0.03 mol based on the total molar amount of the repeating units (1). % Of the polycarbonate resin composition of Comparative Example 8 having a weight-average molecular weight of more than 18,000 and a polycarbonate resin composition of Comparative Example 10 having a weight-average molecular weight of more than 18,000. Could not be obtained. Therefore, D at 390 ° C
When the VD substrate was molded, a streak-like defect phenomenon that could be detected through the polarizing plate was observed on the disk. It is considered that this defective phenomenon occurred because the molecular weight of the polycarbonate resin decreased due to thermal deterioration and leaked from the nozzle of the injection molding machine.

The polycarbonate of Comparative Example 9 in which the total amount of the heterogeneous units (A) and the heterogeneous units (B) contained in the polycarbonate resin exceeds 0.30 mol% with respect to the total molar amount of the repeating units (1) 370 using a resin composition
When the DVD substrate was molded at a temperature of ° C., the substrate could be molded without any problem. However, although the obtained DVD substrate showed good transferability, an optical defect occurred in the wet heat resistance test. Further, the substrate strength was low, and cracks occurred in the substrate in the bending test. Also, the weight average molecular weight is 1
When a DVD substrate was molded at 370 ° C. using the polycarbonate resin composition of Comparative Example 11 having a molecular weight of less than 3,000, a problem that the sprue could not be removed from the mold at the time of molding occurred occasionally, and a good disk substrate was produced. I couldn't get it. In addition, the disk substrate that could be manufactured without any trouble was cracked in the bending test.

[0114]

Comparative Examples 12 and 13 A polycarbonate resin composition containing an acidic compound was obtained in the same manner as in Example 3 by using a polycarbonate resin polymerized in the same manner as in Example 1 and using the amount of the acidic compound shown in Table 9. Was. Various properties of the obtained polycarbonate resin were evaluated according to the above methods.
Table 9 shows the evaluation results. Further, a DVD substrate was molded using the obtained polycarbonate resin composition by the above method, and the substrate characteristics were evaluated. Table 10 shows the evaluation results. As apparent from Table 10, the polycarbonate resin composition of Comparative Example 12 containing less than 0.1 × 10 ⁻⁴ parts by weight of the acidic compound and the polycarbonate resin of Comparative Example 13 containing more than 100 × 10 ⁻⁴ parts by weight In each of the DVD substrates obtained by molding each of the compositions, a number of optical defects occurred in a wet heat resistance test at 110 ° C.

[0115]

Comparative Example 14 A polycarbonate resin composition containing an acidic compound was obtained in the same manner as in Example 3 except that a polycarbonate resin polymerized in the same manner as in Comparative Example 6 was used. Various properties of the obtained polycarbonate resin were evaluated according to the above methods. Table 9 shows the evaluation results. Further, using the obtained polycarbonate resin composition, a DVD
A substrate for molding was formed, and the characteristics of the substrate were evaluated. Table 10 shows the evaluation results. As is clear from Table 10, Comparative Example 1 in which the polycarbonate resin does not contain the heterogeneous bonding unit (B).
D at 370 ° C. using the polycarbonate resin composition
When the substrate for VD was molded, the substrate for DVD was 110
Optical defects occurred in the moist heat resistance test at ℃. Further, the substrate strength was low, and cracks occurred in the substrate in the bending test.

[0116]

[Table 9]

[0117]

[Table 10]

[0118]

The polycarbonate resin of the present invention has a high temperature (approximately 3) which does not cause thermal deterioration of the polycarbonate resin.
(20 ° C. to about 370 ° C.), a sufficiently high melt fluidity is exhibited. Therefore, when the polycarbonate resin of the present invention is used for the production of a substrate for an optical information medium, it has excellent optical properties such as low birefringence and is transferred. High performance (that is, information of a stamper (a mold for forming a groove in a substrate) is accurately transferred)
A substrate can be obtained. Therefore, the polycarbonate resin of the present invention includes CD, MD, CD-ROM, CD-R,
CD-RW, DVD-ROM, DVD-R, DVD-R
It can be advantageously used for manufacturing substrates for optical information media such as W, MD, and MO.

Claims (8)

[Claims] 1. A polycarbonate resin containing substantially no chlorine atom, which is produced by subjecting an aromatic dihydroxy compound and a carbonic acid diester to a transesterification reaction, comprising a plurality of aromatic polycarbonate main chains. And each aromatic polycarbonate main chain contains a plurality of repeating units each independently represented by the following formula (1): (In the formula, Ar represents a divalent C ₅ -C ₂₀₀ aromatic group.) Further, the plurality of polycarbonate main chains as a whole comprise at least one heterogeneous bonding unit (A) and at least one heterogeneous bonding unit (B). Is present on the polycarbonate main chain, and the heterogeneous bonding unit (A) is represented by the following formula (2): (In the formula, Ar ′ represents a trivalent C ₅ -C ₂₀₀ aromatic group, and X represents a compound of the formula: (Wherein, Ar is as described above), and represents a polycarbonate chain having a weight average molecular weight of 214 to 6,000, containing a repeating unit represented by the following formula: However, when the polycarbonate main chain has a plurality of hetero bond units (A), the plurality of hetero bond units (A) may be the same or different, and the hetero bond unit (B) is represented by the following formula: Represented by (3), (In the formula, Ar ′ is as described above.) However, when the polycarbonate main chain has a plurality of hetero bond units (B), the plurality of hetero bond units (B) may be the same or different. X in the above formula (2) may contain at least one heterogeneous bond unit selected from the group consisting of the heterogeneous bond units (A) and (B), and the heterogeneous bond unit (A) and the heterogeneous bond unit ( B) is 0.03 to the total molar amount of the repeating unit (1).
And the amount of the heterogeneous bonding unit (A) is 50 mol% or more based on the total molar amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B). A polycarbonate resin for producing a substrate for an optical information medium, having a molecular weight in the range of 13,000 to 18,000. 2. An absorption wave number of 1740 cm ^{−1 having a} particle size of 5 μm or more and measured by infrared absorption spectroscopy.
Absorption strength A ₁ of the stretching vibration of the carbonyl group contained in the non-carbonate type ester bond in the polycarbonate resin and absorption of the stretching vibration of the carbonyl group contained in the carbonate type ester bond in the polycarbonate resin at an absorption wave number of 1780 cm ^-1 . Ratio A _{1 to} strength A ₂ /
_{2. The} polycarbonate resin according to claim 1, comprising 20 or less thermally degraded particles having a degree of thermal degradation of 0.2 or more represented by A ₂ per 100 g of the polycarbonate resin. 3. 3. The amount of the heterogeneous bonding unit (A) is 50 to 95 mol% based on the total molar amount of the heterogeneous bonding unit (A) and the heterogeneous bonding unit (B). Claim 1
Polycarbonate resin described in 1. 4. The polycarbonate resin according to claim 1, wherein the amount of terminal hydroxyl groups of the polycarbonate resin is 5 to 50 mol% based on the total molar amount of the terminal groups of the polycarbonate resin. 5. The polycarbonate resin according to claim 1, wherein 85% or more of the repeating unit (1) is represented by the following formula (1 ′). Embedded image 6. A substrate for an optical information medium obtained by molding the polycarbonate resin according to claim 1. 7. I) 100 parts by weight of the polycarbonate resin according to claim 1, and (II) 0.1 × 1 of the acidic compound.
0 ^{-4 to} 100 × 10 ^-4 parts by weight of a polycarbonate resin composition for producing a substrate for an optical information medium. 8. An optical information medium substrate obtained by molding the polycarbonate resin composition according to claim 7.