JP2003201396A - Polycarbonate composition, write-once-read-many (worm) optical disk substrate using the same, worm optical disk, and method for manufacturing worm optical disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate composition which excels in both resistance to static electricity and pigment coating properties, a worm optical disk substrate using the same, and a worm optical disk. <P>SOLUTION: The polycarbonate composition comprises (a) a polycarbonate obtained by the transesterification method and (b) a compound having any of an ester bond, a carbonate bond, an amide bond, and a urethane bond in the molecule, an aromatic hydrocarbon group substituted with at least one alkyl group at the molecular terminal and a molecular weight of 300-8,000. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate composition having excellent quality, more specifically, a polycarbonate composition having a fundamentally improved electrostatic resistance and an improved dye coating property. The present invention relates to a write-once optical disc substrate, a write-once optical disc, and a method for manufacturing the write-once optical disc.

[0002]

2. Description of the Related Art Polycarbonate is a resin which is excellent in mechanical properties such as impact resistance and transparency and is used in a wide variety of fields. In particular, the application is expanding as an optical disc used as an optical information recording medium for reproducing information and additionally writing and rewriting information using laser light such as an audio disc, a laser disc, an optical disc memory, or a magneto-optical disc. As an industrial production method of this polycarbonate, an interfacial polymerization method in which bisphenol A and phosgene are reacted in a methylene chloride solvent is generally used, but this method requires the use of phosgene or methylene chloride which is industrially difficult to handle. From
A method for producing a polycarbonate by a transesterification reaction (melt polymerization method) in the absence of a solvent using an aromatic dihydroxy compound such as bisphenol A and a carbonic acid diester such as diphenyl carbonate as raw materials without using these compounds has been partially industrialized. (Japanese Patent Laid-Open No. 63-51429)
No. 2, JP-A-2-153925 and JP-B-6-9955.
No. 2, etc.).

Polycarbonate produced by the above transesterification reaction is a material used for producing compact discs (CDs). However, CDs made from transesterified polycarbonates as disclosed in US Pat. No. 5,606,008 are characterized by a high negative electrostatic charge (typically <-2. 0.0 kV) is generated. This high negative electrostatic charge can cause molded parts to attract dust and degrade the final quality of such discs. Also, due to the high electrostatic charge, the disks attract each other,
During the transportation process, for example during transfer from an injection molding machine, the disks stick to one another, which can lead to situations in which the CD production is stopped or its yield is reduced. Furthermore, due to the increased wettability when applying the dye,
Inadequate dye application occurred. For CD applications where a rewritable substrate is spin coated onto the disc surface, a low negative electrostatic charge is required for uniform wetting of the rewritable layer.

In order to solve the above problems, a method for suppressing a high negative electrostatic charge obtained from an aromatic polycarbonate produced by a transesterification reaction during CD production is disclosed. For example, in JP-A-62-207358 and JP-A-11-279396, an antistatic agent is added to an aromatic polycarbonate. Further, in US Pat. No. 6,022,943, the terminal OH group is reduced to 10 mol% or less based on all the terminal groups by setting the molar ratio of carbonic acid diester to aromatic dihydroxy compound higher than usual. An attempt was made to do so. However, there is almost no effect of adding the antistatic agent, and even if the terminal OH group is reduced, the problem cannot be solved, and a fundamental solution method has been strongly desired.

[0005]

Therefore, the present invention is intended to solve the above-mentioned problems of the prior art, and the object of the present invention is to improve the electrostatic resistance of the polycarbonate obtained by the transesterification method. It is to provide a radically improved polycarbonate composition. Another object of the present invention is to provide a write-once type optical disk substrate having good dye coatability. Another object of the present invention is to provide a write-once optical disc having improved electrostatic resistance.
Another object of the present invention is to provide a method for manufacturing a write-once optical disc with less coating unevenness and improved productivity.

[0006]

Means for Solving the Problems As a result of diligent examination of the difference between the polycarbonate obtained by the interfacial method and the polycarbonate obtained by the transesterification method,
In the polycarbonate obtained by the interfacial method, a linear 1-pentamer in which both ends of bisphenol A, which is a raw material, are substituted with alkylphenol is produced as a by-product of Total in several% (wt% relative to the polycarbonate). It was found that the polycarbonate obtained by the method has the antistatic property due to the contribution of the oligomer whose molecular end is substituted with alkylphenol. Therefore, the inventors have found that by mixing a compound similar to this oligomer with a polycarbonate obtained by a melting method, a melting method polycarbonate having an antistatic property can be obtained, and the present invention has been accomplished.

That is, the gist of the present invention is (a) a polycarbonate obtained by a transesterification method, and (b) a molecule having an ester bond, a carbonate bond, an amide bond or a urethane bond, and having a molecule A polycarbonate composition comprising a compound having an aromatic hydrocarbon group substituted at the end with at least one alkyl group. Another subject matter of the present invention lies in (a) a polycarbonate obtained by a transesterification method, and (b) a polycarbonate composition comprising an oligomer represented by the following formula (1A).

[0008]

[Chemical 5]

(In the formula (1A), G¹Is a hydrogen atom or Ar¹
-Q²Represents -CO-. However, Ar¹Is at least one
It represents an aromatic hydrocarbon group having an alkyl group. G²Is-
Q¹-W ¹-Q²-H or Ar²-Q¹Represents-. However
Ar²Is an aromatic carbon having at least one alkyl group
Represents a hydrogenated group. Also, Q¹Is a single bond, -O-, or-
Represents NH-, Q²Represents -O- or -NH-, W¹Is
It represents a divalent group having 6 to 50 carbon atoms. Also, n is 1
Represents an integer of -30. )

Another subject matter of the present invention resides in a write-once type optical disk substrate using the above polycarbonate composition. Another subject matter of the present invention resides in a write-once type optical disc formed by coating a dye on the optical disc substrate. Another subject matter of the present invention lies in a method for manufacturing a write-once optical disc, characterized in that an optical disc substrate is obtained by injection-molding the above polycarbonate, and a dye is applied thereto by spin coating.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The polycarbonate composition having excellent electrostatic resistance of the present invention includes (a) a polycarbonate obtained by a transesterification method, and (b) having an ester bond, a carbonate bond, an amide bond, or a urethane bond in the molecule, Having an aromatic hydrocarbon group substituted with at least one alkyl group at a molecular end and having a molecular weight of 300 to 80
And a compound which is 00.

The compound (b) has a portion having a relatively high affinity for polycarbonate inside the molecule,
Further, it is characterized by having a portion having a relatively low affinity for polycarbonate at the terminal of the molecule. The portion having a relatively high affinity for polycarbonate is an ester bond, a carbonate bond, an amide bond or a urethane bond in the compound molecule, while the portion having a relatively low affinity for polycarbonate is at least one alkyl group. It is an aromatic hydrocarbon group substituted with.

The reason why the polycarbonate composition of the present invention exerts an excellent effect on electrostatic resistance is not always clear, but it is presumed as follows. The polycarbonate obtained by the transesterification method has a high proportion of terminal hydroxyl groups and tends to have a large negative chargeability, but the compound of the component (b) is an aromatic hydrocarbon group substituted with an alkyl group at the molecular end. It is considered that this has the effect of blocking the negative charging property. The compound (b) has a lower molecular weight than the polycarbonate which is the main component of the composition of the present invention, and due to the action of the aromatic hydrocarbon group substituted with an alkyl group, the compound (b) is not formed on the surface of the composition when molded. It tends to leach out easily. And the compound (b) simultaneously has a portion having a high affinity for polycarbonate in the molecule,
Therefore, it is considered that the polycarbonate composition is effectively retained on the surface of the molded product.

The molecular weight of the compound (b) is 300 to 8000.
However, the molecular weight is preferably 400 or more, 50
0 or more is more preferable. Further, it is preferably 5,000 or less, more preferably 3,000 or less. When the molecular weight is smaller than the above range, the compound (b) is less likely to be retained in the composition when the composition is molded, and when the molecular weight is larger than the above range, the contribution of the terminal alkyl group-substituted aromatic hydrocarbon group is contributed. Becomes extremely small.

The compound (b) has an ester bond in the molecule,
Although it has a carbonate bond, an amide bond, and a urethane bond, two or more of these bond species may be contained in the same molecule. Also, a mixture of compounds each having a different binding species may be used. K is the total number of ester bonds, carbonate bonds, amide bonds and urethane bonds in the molecule.
In that case, the molecular weight / k is preferably 150 to 1000, and more preferably 200 to 500. If the molecular weight / k is within the above range, the polycarbonate (a) and the compound (b)
Good affinity with.

The compound (b) is, from the viewpoint of production thereof,
It is preferably an oligomer having a repeating unit and an ester bond, a carbonate bond, an amide bond, or a urethane bond in the molecule. That is, the oligomer of the component (b) is selected from carbonate oligomer, ester oligomer, amide oligomer and urethane oligomer. These oligomers have an ester bond, a carbonate bond, an amide bond, or a urethane bond in the molecule, and as a result, they have a relatively high affinity with the polycarbonate. Examples of the oligomer having an ester bond include ethylene terephthalate oligomer and butylene terephthalate oligomer. Examples of the oligomer having a carbonate bond include bisphenol A carbonate oligomer. Examples of the oligomer having an amide bond include a caprolactam oligomer and a hexamethylenediamine-adipic acid oligomer. Examples of the oligomer having a urethane bond include an oligomer of tolylene diisocyanate-propylene glycol.

The oligomer used as the compound (b) is preferably represented by the following formula (1A).

[0018]

[Chemical 6]

(In the formula (1A), G1 is a hydrogen atom or Ar.¹
-Q²Represents -CO-. However, Ar¹Is at least one
It represents an aromatic hydrocarbon group having an alkyl group. G²Is-
Q¹-W ¹-Q²-H or Ar²-Q¹Represents-. However
Ar²Is an aromatic carbon having at least one alkyl group
Represents a hydrogenated group. Also, Q¹Is a single bond, -O-, or-
Represents NH-, Q²Represents -O- or -NH-, W¹Is
It represents a divalent group having 6 to 50 carbon atoms. Also, n is 1
Represents an integer of -30. )

Among the oligomers represented by the formula (1A), the oligomer represented by the formula (1B) is preferable.

[0021]

[Chemical 7]

(In the formula (1B), G ¹ is a hydrogen atom or Ar ¹
Represents -O-CO-. However, Ar ¹ represents an aromatic hydrocarbon group substituted with at least one alkyl group. G ²
Is

[0023]

[Chemical 8]

Alternatively, it represents Ar ² —O—. However, Ar ² represents an aromatic hydrocarbon group substituted with at least one alkyl group. In formula (2A), W ² is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, or 5 to 5 carbon atoms.
15 cycloalkylidene groups or -O-, -S-,-
CO -, - SO -, - SO 2 - those selected from the group consisting of divalent groups represented by, Y and Z represents a halogen or a hydrocarbon group having 1 to 6 carbon atoms. p and q are 0
It is an integer of 2, and Y and Z and p and q may be the same or different. Moreover, n represents the integer of 1-30. )

In the above formula, Ar ¹ and Ar ² are at least 1
It represents an aromatic hydrocarbon group having two alkyl groups. As the aromatic hydrocarbon group, a phenyl group and a naphthyl group are preferable, and a phenyl group is particularly preferable. The alkyl group is preferably an alkyl group having 1 to 20 carbon atoms. Further, a group represented by the following formula (5A) is preferable.

[0026]

[Chemical 9]

(In formula (5A), R ^{1 to} R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, provided that all of R ^{1 to} R ⁵ are hydrogen atoms. .)

In the above formula (4), R ^{1 to} R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, but in order to make electrostatic resistance effective, R ^{1 to} R ⁵ The total number of carbon atoms of R ⁵ to R ⁵ is preferably 2 or more, and more preferably 3 or more. From the viewpoint of producing an oligomer, the total number of carbon atoms of R ^{1 to} R ⁵ is preferably 10 or less. As the aromatic hydrocarbon group having at least one alkyl group, an alkylphenyl group is particularly preferable, and specifically, a mesityl group, a tert-butylphenyl group, an isopropylphenyl group, 1,3,5,7-tetramethyl. Examples thereof include an octylphenyl group, and among them, a tertiary butylphenyl group (t-butylphenyl group) is preferable, and a 4-t-butylphenyl group is most preferable.

N in the above formula (1) (number of repeating units)
Is usually 30 or less, preferably 28 or less,
More preferably, it is 26 or less. For example, an oligomer obtained by an interfacial polymerization method is usually obtained as a mixture having different repeating numbers. As the number average number of repeating units (m) of the oligomer used in the present invention,
It is preferably 20 or less, more preferably 15 or less, and particularly preferably 10 or less.

The amount of the compound (b) in the polycarbonate composition of the present invention is usually 0.01 to 20 parts by weight, and preferably 0.05 to 20 parts by weight, based on 100 parts by weight of the component (a) polycarbonate. 18 parts by weight is preferable, and 0.1 to
More preferably 16 parts by weight. When a flat plate such as an optical disc substrate is manufactured using a polycarbonate composition in which the amount of the compound (b) is significantly less than the above range, it is -2.0 k.
The negative electrification voltage exceeding V becomes high, dust is easily attracted, and further, the wettability at the time of dye application is increased, so that dye application failure is likely to occur. Further, when a flat plate such as an optical disc substrate is manufactured using a polycarbonate composition in which the amount of the compound (b) is significantly higher than the above range, a large amount of deposits on the stamper occurs, which causes the product. The adverse effect of deposits on the disk surface can be seen.

Further, it is considered that the smaller the number of repetitions n among the oligomers (b) is, the higher the electrostatic resistance effect is. Therefore, the proportion of the components having a number of repetitions 2 to 4 in the oligomer (b) is as follows. In the composition, the amount is preferably 0.02 to 15 parts by weight, and more preferably 0.05 to 10 parts by weight, based on 100 parts by weight of the component (a) polycarbonate.

The compound which is the component (b) of the present invention can be produced by a known method. Among them, the oligomer represented by the formula (1B) is preferably one obtained by an interfacial polymerization method. According to the interfacial polymerization method, the number of repeating oligomers can be controlled by reacting an aromatic dihydroxy compound with phosgene and reacting with an alkylphenol compound at the stage of an oligomer grown into a desired repeating unit. At this time, the molecular terminal of the oligomer can be variously changed depending on the kind of the alkylphenol compound used as the terminal stopper.

In the present invention, the alkylphenol used for introducing the alkylphenyl group at the molecular end of the oligomer (b) includes 2-n-ethylphenol and 3-n-ethylphenol.
n-ethylphenol, 4-n-ethylphenol, 2
-N-propylphenol, 3-n-propylphenol, 4-n-propylphenol, 2-n-butylphenol, 3-n-butylphenol, 4-n-butylphenol, 2-isobutylphenol, 3-isobutylphenol, 4- Isobutylphenol, 2-t-butylphenol, 3-t-butylphenol, 4-t-butylphenol, 2-n-pentylphenol, 3-n
-Pentylphenol, 4-n-pentylphenol,
3-n-hexylphenol, 3-n-hexylphenol, 4-n-hexylphenol, 2,3-di-t-
Butylphenol, 2,4-di-t-butylphenol, 2,5-di-t-butylphenol, 3,4-di-
t-butylphenol, 3,5-di-t-butylphenol, 2-n-dodecylphenol, 3-n-dodecylphenol, 4-n-dodecylphenol and 1,3,3
5,7-Tetramethyloctylphenol and the like can be mentioned. Among these alkylphenols, 4-t-butylphenol and 1,3,5,7-tetramethyloctylphenol are preferable, and 4-t-butylphenol is particularly preferable, from the viewpoint of oligomer production and handling.

Further, G1 and G2 in the above formula (1A) or (1B), which are the molecular ends of the oligomer (b),
Is a group having an alkylphenyl group derived from an alkylphenol or a hydroxyl group derived from a dihydroxy compound. It is preferred that the alkylphenyl group is predominant at the molecular end of the oligomer used in the present invention,
Specifically, the proportion of alkylphenyl groups is preferably 80 mol% or more, more preferably 90 mol% or more, based on the total number of molecular terminals. In this case, the main component is an oligomer (b) in which both molecular ends are alkylphenyl groups. A particularly preferred oligomer used in the present invention, in which both molecular terminals are alkylphenyl groups, is represented by the following formula (4).

[0035]

[Chemical 10]

(In the formula (4), W is a single bond and has 1 to 8 carbon atoms.
Alkylene group, an alkylidene group having 2 to 8 carbon atoms, a cycloalkylene group having 5 to 15 carbon atoms, a cycloalkylidene group having 5 to 15 carbon atoms, or -O-, -S-, -CO-,
Selected from the group consisting of divalent groups represented by —SO— and —SO ₂ —, Y and Z are halogen or a hydrocarbon group having 1 to 6 carbon atoms, and p and q are 0 to 0. It is an integer of 2, and Y and Z and p and q may be the same or different. In addition, n represents an integer of 1 to 30, and R ^{1 to} R ⁵ each independently represent a hydrogen atom or a carbon number of 1 to 1.
20 alkyl groups. However, the case where R ^{1 to} R ⁵ are all hydrogen atoms is excluded. )

When a flat plate such as an optical disc substrate is manufactured by adding a specific amount of the compound (b) containing an oligomer having alkylphenyl groups at both molecular ends to the polycarbonate, an optical disc is prepared. The value of the electrification voltage of a flat plate such as a substrate becomes a value larger than -2.0 kV, dust cannot be attracted, and the wettability at the time of dye application is lowered, so that dye application failure is less likely to occur. On the other hand, when a flat plate such as an optical disc substrate is manufactured by using a polycarbonate that does not contain the above oligomer in a specific amount, the value of the electrification voltage of the flat plate such as the optical disc substrate is −
It becomes a value smaller than 2.0 kV, which makes it easier to attract dust, and due to the increased wettability during dye application,
Dye application failure tends to occur. The electrification voltage of a flat plate such as an optical disc substrate produced from the aromatic polycarbonate of the present invention having excellent static resistance is -2 to 8
It is preferably in the range of KV, more preferably −
It is in the range of 1.5 to 7.5 KV, particularly preferably −
It is in the range of 1.0 to 7.0 KV.

In addition to this, it is preferable that the flat plate such as the optical disc substrate has a water droplet contact angle of 78 degrees or more,
It is more preferably 80 degrees or more, and particularly preferably 82 degrees or more. If the contact angle of water drops on a flat plate such as an optical disk substrate is 78 degrees or more, the wettability at the time of dye application decreases,
If the dye application failure is less likely to occur, and if it is smaller, on the contrary, the dye application failure tends to occur due to an increase in wettability during dye application.

The above polycarbonate composition of the present invention comprises
Furthermore, it is preferable to include (c) an antistatic agent. By including the antistatic agent, the effect of static resistance can be further improved. The content of the antistatic agent is preferably 0.001 to 0.1 part by weight, more preferably 0.01 to 0.1 part by weight, based on 100 parts by weight of the polycarbonate.
It is to contain 05 to 0.09 weight part. Preferred antistatic agents are polyoxyethylene fatty acid esters, for example, polyoxyethylene sorbitan monolaurate, polyoxyethylene monolaurate, polyoxyethylene sorbitan stearate, polyoxyethylene lauryl ether, polyoxyethylene oleyl. Ether or polyoxyethylene stearyl ether. The most preferred antistatic agent among these is polyoxyethylene sorbitan monolaurate.

The polycarbonate composition of the present invention contains the polycarbonate (a) as a main component. This polycarbonate uses an aromatic dihydroxy compound and a carbonic acid diester as raw materials, and in the presence of a transesterification catalyst, the ester is used. It can be obtained by an exchange reaction. The aromatic dihydroxy compound used as a raw material of polycarbonate is usually represented by the following formula (2B).

[0041]

[Chemical 11]

(In the formula (2B), W ² is a single bond and has 1 carbon atom.
~ 8 alkylene group, C2-8 alkylidene group,
C5-C15 cycloalkylene group, C5-C15
Cycloalkylidene group or -O-, -S-, -CO
Selected from the group consisting of divalent groups represented by —, —SO—, and —SO ₂ —, Y and Z are halogen or a hydrocarbon group having 1 to 6 carbon atoms, and p and q are It is an integer of 0 to 2, and Y and Z and p and q may be the same or different. )

Examples of the aromatic dihydroxy compound represented by the above formula (2B) include bis (4-hydroxydiphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4). -Hydroxy-3-
Methylphenyl) propane, 2,2-bis (4-hydroxy-3-t-butylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4 Bisphenols such as -hydroxy-3,5-dibromophenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane and 1,1-bis (4-hydroxyphenyl) cyclohexane; 4,4 '
-Biphenol such as dihydroxybiphenyl, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl; bis (4-hydroxyphenyl) sulfone,
Bis (4-hydroxyphenyl) sulfide, bis (4
-Hydroxyphenyl) ether, bis (4-hydroxyphenyl) ketone, etc. are exemplified, but 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as "bisphenol A") is particularly preferable. .
These aromatic dihydroxy compounds may be used alone or as a mixture of two or more kinds. The carbonic acid diester used in the present invention is represented by the following general formula (3).

[0044]

[Chemical 12]

(In the formula (3), A and A'have 1 to 1 carbon atoms.
8 aliphatic groups or substituted aliphatic groups, or aromatic groups or substituted aromatic groups, which may be the same or different. ) Examples of the carbonic acid diester represented by the general formula (3) include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate, and di-t-butyl carbonate, and diphenyl carbonate, but preferably diphenyl carbonate and substituted It is diphenyl carbonate, and diphenyl carbonate is particularly preferable. These carbonic acid diesters may be used alone or in combination of two or more.

In order to produce an aromatic polycarbonate in the present invention, bisphenol A is used as an aromatic dihydroxy compound and diphenyl carbonate is used as a carbonic acid diester. The diphenyl carbonate is 1.01 to 1.30 with respect to 1 mol of bisphenol A. It is preferably used in a molar amount, preferably 1.02 to 1.20. If the molar ratio is less than 1.001, the number of terminal OH groups of the produced aromatic polycarbonate is increased, and the thermal stability of the polymer is deteriorated. If the molar ratio is more than 1.3, under the same conditions. The rate of transesterification tends to decrease, making it difficult to produce an aromatic polycarbonate having a desired molecular weight.

In the present invention, a transesterification catalyst is used to obtain the polycarbonate. An alkali metal compound and / or an alkaline earth metal compound is used as the catalyst, and a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound is additionally used in combination. However, it is particularly preferable that the alkali metal compound and / or the alkaline earth metal compound be used alone from the viewpoint of physical properties and handling.

The catalyst amount is aromatic dihydroxy.
1 × 10 with respect to 1 mol of the compound^-8~ 5 x 10^-6Mole
It is preferably used in the range, more preferably 1 ×
10 ^-7~ 3 x 10^-6In the molar range, particularly preferably 2 ×
10^-7~ 2 x 10^-6Used in the molar range. This amount
If the amount is less, the molecular weight and the amount of terminal hydroxy groups will be
Provides the polymerization activity necessary to produce the carbonate
If the amount is more than this amount, the polymer hue deteriorates, and
There is a tendency that the moldability of the polymer is impaired due to the large number of
It

Examples of the alkali metal compound include sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, cesium hydrogen carbonate, sodium carbonate, potassium carbonate and carbonic acid. Lithium, cesium carbonate, sodium acetate, potassium acetate, lithium acetate, cesium acetate, sodium stearate, potassium stearate, lithium stearate, cesium stearate, sodium borohydride, potassium borohydride, lithium borohydride, hydride Cesium boron, sodium phenyl boride, potassium phenyl boride, lithium phenyl boride, cesium phenyl boride, sodium benzoate, potassium benzoate, lithium benzoate,
Cesium benzoate, disodium hydrogen phosphate, 2 potassium hydrogen phosphate, 2 lithium hydrogen phosphate, 2 cesium hydrogen phosphate, 2 sodium phenyl phosphate, 2 potassium phenyl phosphate, 2 lithium phenyl phosphate, 2 phenyl phosphate Cesium, sodium, potassium, lithium, cesium alcoholate, phenolate, bisphenol A
2 sodium salt, 2 potassium salt, 2 lithium salt, 2 cesium salt and the like.

As the alkaline earth metal compound,
For example, calcium hydroxide, barium hydroxide, magnesium hydroxide, strontium hydroxide, calcium hydrogen carbonate, barium hydrogen carbonate, magnesium hydrogen carbonate, strontium hydrogen carbonate, calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, calcium acetate, acetic acid. Examples thereof include barium, magnesium acetate, strontium acetate, calcium stearate, barium stearate, magnesium stearate, and strontium stearate.

Specific examples of the basic boron compound include tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron and triethylphenyl. Boron, tributylbenzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, sodium salts such as butyltriphenylboron, potassium salts, lithium salts, calcium salts, barium salts, magnesium salts, or strontium. Salt etc. are mentioned.

Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine,
Alternatively, a quaternary phosphonium salt and the like can be mentioned.

Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide,
Trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltri Examples thereof include phenylammonium hydroxide, methyltriphenylammonium hydroxide, butyltriphenylammonium hydroxide and the like.

Examples of amine compounds include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine,
2-hydroxypyridine, 2-methoxypyridine, 4-
Methoxypyridine, 2-dimethylaminoimidazole,
2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like can be mentioned.

The transesterification reaction is generally carried out in a multi-step process of two or more steps. Specifically, the reaction of the first step was carried out under reduced pressure of 9.3 × 10 ^{4 to} 1.33 × 10 ³ Pa.
The reaction is carried out at a temperature of 20 to 260 ° C., preferably 180 to 240 ° C. for 0.1 to 5 hours, preferably 0.1 to 3 hours. Then, the reaction temperature is raised while increasing the degree of pressure reduction of the reaction system, and finally 240 to 32 under reduced pressure of 133 Pa or less.
The polycondensation reaction is carried out at a temperature of 0 ° C.

The reaction may be carried out in a batch system, a continuous system or a combination of a batch system and a continuous system, and the apparatus used may be a tank system, a tube system or a column system. Good. The viscosity average molecular weight of the polycarbonate in the present invention is preferably 12,000 to 2
It is in the range of 10,000, more preferably 13,0
The range is from 00 to 19,000. If the viscosity average molecular weight is too low, the strength cannot be practically endured, and if it is too high, sufficient performance cannot be obtained in terms of moldability and optical properties.

The alkyl group-substituted aromatic hydrocarbon which exhibits electrostatic resistance in the polycarbonate composition of the present invention is present in the compound (b). In addition to this, the molecular terminal of the polycarbonate (a) is added. An alkyl group-substituted aromatic hydrocarbon group may be introduced into. When an alkyl-substituted aromatic hydrocarbon group is introduced at the terminal of the polycarbonate, the ratio of the alkyl-substituted aromatic hydrocarbon group to all polycarbonate terminals is preferably 0.1 mol% or more, 1
It is preferably at least mol%. When the amount of the oligomer in the composition is small, or when the proportion of the alkyl-substituted aromatic hydrocarbon group at the oligomer end is small, the proportion of the alkyl-substituted aromatic hydrocarbon group at the polycarbonate end is increased, and The ratio can be appropriately selected.

In order to produce a polycarbonate having an alkyl-substituted aromatic hydrocarbon group introduced at the terminal, the above-mentioned aromatic dihydroxy compound and carbonic acid diester are used, and the transesterification reaction is carried out in the presence of a transesterification catalyst. The phenols represented by the following formula (5B) or the carbonic acid diesters represented by the following formula (6) can coexist in the reaction system.

[0059]

[Chemical 13]

(In the formula (5B), R ^{1 to} R ⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, provided that all of R ^{1 to} R ⁵ are not hydrogen atoms. )

[0061]

[Chemical 14]

(In the formula (6), R ^{6 to} R ¹⁵ represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, but all of R ^{6 to} R ¹⁵ are not hydrogen atoms.)

The above-mentioned phenols or carbonic acid diesters may be added together with the above raw materials in advance, or may be added during the reaction or at the end of the reaction. η] is 0.2 dl
It is better to add and manufacture it at the time of less than / g. When the intrinsic viscosity [η] of the polymer is 0.2 dl / g or more, the mixing efficiency with the polymer and the dispersibility deteriorate as the viscosity increases, so that the introduction efficiency tends to decrease. More preferably, it is 0.19 dl / g or less.

In particular, in the case of phenols represented by the above formula (5B), from the viewpoint of introduction efficiency, the intrinsic viscosity [η] of the polymer is 0.03 dl / g or more and 0.2 dl / g or more.
It is preferred to add at a time of less than. This is because, when these phenols are added together with the above raw materials in advance, the aromatic hydroxy compound, which is a byproduct of transesterification, and the phenols represented by the above formula (5B) are entrained and distilled off, so that the introduction efficiency is high. It tends to decrease. Preferably, 0.04 dl / g or more and 0.19 dl /
g or less.

The method for producing the composition of the present invention includes:
It can be mixed by a conventionally known method. For example,
A method may be selected in which the above oligomer is dispersed and mixed with the polycarbonate powder with a ribbon blender, a super mixer or the like, and then melt-kneaded with an extruder or the like.

In the present invention, in order to deactivate the transesterification catalyst, it is preferable to add a sulfonic acid compound or its precursor to the acidic compound or its precursor as a deactivator, and more specifically, p-toluenesulfonic acid,
Methyl p-toluenesulfonate, butyl p-toluenesulfonate and the like are particularly preferable. These may be used alone or in combination of two or more. Furthermore, if necessary, a stabilizer, an ultraviolet absorber, a release agent,
It is also possible to add an additive such as a colorant and knead with the resin.

The optical disk substrate of the present invention can be obtained by injection molding the above polycarbonate by a conventionally known method. Further, the optical disk substrate is used as an optical information recording medium for reproducing information and additionally writing / rewriting information by using laser light such as an audio disk, a laser disk (registered trademark), an optical disk memory, or a magneto-optical disk. It can be used as a write-once optical disc substrate.

The write-once type optical disk of the present invention is made of a molded substrate, which is manufactured by injection molding of the aromatic polycarbonate and has a plurality of concentric guide grooves called grooves. At the time of this injection molding, the shape of the submicron-sized pits and grooves pre-engraved on a predetermined stamper is the surface of a disk-shaped transparent molded substrate (referred to as "signal surface" in this specification). It is obtained by faithfully transferring to.

Further, as a typical write-once optical disc, for example, a CD-recording layer, a reflection layer, and a protective layer are laminated in this order on the above-mentioned molded substrate.
In addition to the R-type optical disc, a laminated body including a dye recording layer, a reflective layer, and a protective layer optionally provided and a disk-shaped substrate (dummy plate) are provided on the above-mentioned molded substrate so that the recording layer is on the inner side. There are provided a DVD-R type optical disc having a constitution in which they are adhered with an adhesive, and a DVD-R type optical disc having a constitution in which the above two laminated bodies are adhered with an adhesive so that both recording layers are inside. is there. In the method of the present invention, the dye recording layer for recording and reading signals in the write-once optical disc is formed by directly applying the dye to the signal surface on the substrate.

Further, the dye is usually applied by a spin coating method so that a dye solution in which an organic dye is dissolved in an organic solvent is applied so as to fill the groove formed on the signal surface of the molded substrate. It is done by The spin coating method is generally carried out according to the following procedure using a spin coating device including a coating liquid applying device (dispensing nozzle), a spinner head, a shatterproof wall, and an exhaust device. First, the molded substrate is placed on the spinner head, and then, while rotating the spinner head by the drive motor, on the surface of the inner peripheral portion of the substrate, preferably within 2 to 3 mm from the innermost peripheral edge of the groove. position,
The coating liquid is supplied from the nozzle of the coating liquid application device. The coating liquid supplied onto the substrate is radially cast on the outer peripheral side by centrifugal force to form a coating film. During the spin coating operation, a dry gas such as air is introduced through an opening (gas inlet) provided above the shatterproof wall, the gas is circulated on the coating film, and exhausted from below the spin coating device. . By the circulation of this gas, the solvent is removed from the coating film and the coating film is dried. If necessary, the substrate is put into a drying oven called baking to remove the residual solvent as completely as possible.

In the case of the write-once optical disc, the dye is
A dye having an absorption region in the laser light wavelength range (300 to 850 nm) is selected. Specifically, azo dyes, cyanine dyes, phthalocyanine dyes, azurenium dyes, squarylium dyes, polymethine dyes, pyrylium dyes, thiopyrylium dyes, indoaniline dyes, naphthoquinone dyes, anthraquinone dyes, triallylmethane dyes, aminium dyes, diimonium dyes, Examples thereof include metal chelate dyes composed of an azo ligand compound and a metal, metal complexes and the like, and mixtures thereof. Preferred are organic dyes of azo type, cyanine type and phthalocyanine type. These dyes have excellent signal sensitivity, are easily dissolved in a solvent, have good light resistance, and make it possible to obtain a high-quality write-once optical disc.

Specific examples of the organic solvent for the dye solution include esters such as butyl acetate and cellosolve acetate,
Methyl ethyl ketone, cyclohexanone, ketones such as methyl isobutyl ketone, chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, amides such as dimethylformamide, hydrocarbons such as cyclohexane, ethers such as tetrahydrofuran, ethyl ether, dioxane, ethanol. , Alcohols such as n-propanol, isopropanol, n-butanol and diacetone alcohol, fluorine-based solvents such as 2,2,3,3-tetrafluoropropanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether And other glycol ethers. These solvents may be used alone or in combination of two or more in consideration of the solubility of the dye used. Preferably 2, 2, 3,
It is a fluorine-based solvent such as 3-tetrafluoropropanol, octafluoropentanol, and dibutyl ether.

Further, a reflective film such as Ag or Au is formed on the surface of the dye recording layer by a sputtering method to form a reflective layer, and if necessary, a protective film is formed on the surface of the reflective layer to form a protective layer. A laminated body is obtained. In the case of a CD-R, it is formed of a single plate, but in the case of a DVD-R, it is possible to achieve high density by sticking two of the above substrates together.

[0074]

The present invention will be described with reference to the following examples and comparative examples. The physical properties and evaluations of the polycarbonate compositions and polycarbonates obtained in the following examples and comparative examples were measured as follows.

(1) Viscosity average molecular weight (Mv) The intrinsic viscosity of a 6 g / l methylene chloride solution was measured using an Ubbelohde viscometer, and the viscosity average molecular weight was determined by the following formula.

[0076]

[Equation 1] [η] = 1.23 × 10 ⁻⁴ (Mv) ^0.83

(2) Ratio of alkylphenyl groups to the total number of molecular terminals in the oligomer 0.02 g of a sample was dissolved in 0.4 ml of chloroform and 1 H-NMR (JNM-Al manufactured by JEOL Ltd.) was performed at 30 ° C.
400) was used to measure the alkylphenoxy group and terminal hydroxyl group in the oligomer, and these were summed to determine the total number of molecular terminals. The ratio of the alkylphenoxy group to the total number of molecular terminals in the oligomer was determined by the following formula.

[0078]

## EQU00002 ## Ratio of alkylphenoxy group (mol%) = (number of alkylphenoxy groups / total number of molecular terminals) × 100

(3) Number average number of repeating units of oligomer (m) If there are N repeating units in the oligomer and the weight% in the oligomer having a certain repeating unit number p is Mp,
It is calculated by m = (ΣNp × Mp) / 100.

(4) Polycarbonate 10 as component (a)
1 part of the obtained polycarbonate composition was dissolved in 10 ml of tetrohydrofuran, and 0 part by weight was added to 10 parts by weight of the oligomer (b) and the total number of oligomers having a repeating unit number (n) of 2 to 4. It was measured by phase chromatography. Reversed-phase liquid chromatography uses a mixed solvent consisting of tetrohydrofuran and water as an eluent,
The measurement was performed at a column temperature of 40 ° C. under the condition that the ratio of tetrohydrofuran / water was started from 50/50 and the gradient was 100/0 in 1 hour.

For detection, a UV detector having a wavelength of 270 nm (SPD-6A, manufactured by Shimadzu Corporation) was used. For quantification, a calibration curve of an oligomer having a repeating unit number (n) of 1 was used to repeat each peak area. The number of units (n) is converted into the weight of one oligomer, and the weight of each oligomer is calculated.
For 100 parts by weight of the component (a) polycarbonate,
The total parts by weight of the oligomer (b) and the total number of the oligomers having repeating units (n) of 2 to 4 were calculated.

(5) Charge voltage (kV) The withstand voltage of the molded substrate immediately after molding obtained in Examples and Comparative Examples was measured by SK-200 electrostatic field meter (KEYENCE CORPORATION).
Manufactured by the company) at a distance of 6.0 cm from the flat plate.

(6) Water Droplet Contact Angle (degrees) Similar to the electrification voltage in the item (5), ultrapure water was dropped on the surface of a molded substrate immediately after molding, and a contact angle meter (liquid method: manufactured by Kyowa Kagaku Co., Ltd.) was used. ), The radius r and height h of the droplet were measured, and the contact angle was calculated.

[0084]

[Equation 3] θ = 2 × tan ⁻¹ (h / r)

(7) Evaluation Method of Dye Coating Unevenness The position of the innermost circumference of the write-once type optical disk substrate obtained in Examples and Comparative Examples from the perfect circle to the inside was observed with an optical microscope, and the entire circumference was examined. If even a part of the protrusion of 0.5 mm or more was uneven, there was uneven coating.

Example 1 In a stainless steel 20 liter vertical stirring reactor equipped with a condenser, 2283 g (10.0 mol) of bisphenol A, 2290 g (10.7 mol) of diphenyl carbonate, and 0.0 as a catalyst were used.
0.7 ml of 1N sodium hydroxide (bisphenol A1
Nitrogen substitution was carried out by charging 7 × 10 ⁻⁶ mol) with respect to mol. This mixture was melted at 220 ° C. for 40 minutes to melt the raw material monomers, and then at 220 ° C./1.33×10 ⁴ Pa 60
Min, 240 ° C./2.00×10 ³ Pa, 60 minutes, 270
The reaction was carried out at 60 ° C / 66.7 Pa for 60 minutes. After completion of the reaction, the solution was fed to a twin-screw extruder with a gear pump, and butyl p-toluenesulfonate (a two-fold molar amount relative to sodium hydroxide used as a catalyst) was further added as a catalyst deactivator.
4-t-butylphenylphenoxy terminal oligomer obtained by interfacial polymerization method (number average repeating unit number m = 3)
0.5 parts by weight with respect to 100 parts by weight of polycarbonate, 0.02 parts of stearic acid monoglyceride as a release agent, and AS329 (tris-nonylphenyl phosphite, manufactured by Asahi Denka Kogyo Co., Ltd.) as a heat stabilizer. 0.
005 parts were added and kneaded.

The strand emerging from the extruder was cut with a cutter into pellets. As a result, a polycarbonate composition having a viscosity average molecular weight of 15,500 was obtained. (Production of Molded Substrate) The obtained polycarbonate composition was injection-molded under the following conditions to obtain a molded substrate.

[0088]

[Table 1]   Molding machine: Sumitomo Heavy Industries DISK3   Mold: 12cmφ CD, DVD mold   Molded substrate thickness: 1.2 mm   Groove depth of stamper: 160nm   Groove pitch of stamper: 0.80 μm   Maximum setting temperature of molding machine cylinder: 360 ℃   Set mold temperature on the side where the stamper is installed: 130 ℃   Injection time: 0.1 seconds   Cooling time: 7.0 seconds   Screw rotation speed: 360 rpm   Screw diameter: 25mmφ   Mold clamping force: 20T during injection and pressure retention, 25T during cooling

(Application of Dye) A dye solution in which an azo organic dye was dissolved in octafluoropentanol was applied to the molded substrate obtained above. A spin coating method was used to apply the coating so as to fill the grooves formed on the signal surface of the molded substrate. The coating start position was 2 mm inward from the innermost peripheral edge of the groove. Innermost coating rotation speed is 100r
pm, and subsequent coating on the entire surface of the substrate is 5000 rp
m. Then, the substrate was put into a drying oven to remove the residual solvent, and a write-once type optical disc substrate was prepared.

Table 2 shows the evaluation results of the withstand voltage of the molded substrate (before dye coating), the water droplet contact angle, and the dye coating unevenness of the write-once type optical disc substrate. In the oligomers used in Examples 1, 2 and 3, the proportion of the repeating unit number n being 1 was 15% by weight and the proportion of the repeating unit number n being 2 was 20% by weight in the whole oligomer. The ratio of 3 repeating units n is 17% by weight, the ratio of 4 repeating units n is 13% by weight, and the ratio of 5 repeating units n is 8%.
% By weight. The balance has a repeating unit number n of 6 or more. Table 2 shows the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4.

[Example 2] 4-t-used in Example 1
A polycarbonate composition was obtained in the same manner as in Example 1 except that 1 part by weight of butylphenylphenoxy-terminated oligomer (the number average repeating unit number m = 3) was added to 100 parts by weight of the polycarbonate. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Molded substrate (before dye coating)
Table 2 shows the evaluation results of the withstand voltage, water drop contact angle, and dye coating unevenness of the write-once type optical disc substrate.

[Example 3] 4-t-used in Example 1
A polycarbonate composition was obtained in the same manner as in Example 1 except that 5 parts by weight of butylphenylphenoxy-terminated oligomer (number average repeating unit number m = 3) was added to 100 parts by weight of the polycarbonate. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Molded substrate (before dye coating)
Table 2 shows the evaluation results of the withstand voltage, water drop contact angle, and dye coating unevenness of the write-once type optical disc substrate.

[Example 4] 4-t-used in Example 1
A polycarbonate composition was obtained in the same manner as in Example 1 except that 1 part by weight of butylphenylphenoxy-terminated oligomer (number average repeating unit number m = 7) was added to 100 parts by weight of the polycarbonate. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Molded substrate (before dye coating)
Table 2 shows the evaluation results of the withstand voltage, water drop contact angle, and dye coating unevenness of the write-once type optical disc substrate.

[Embodiment 5] 4-t-used in Embodiment 1
A polycarbonate composition was obtained in the same manner as in Example 1 except that 1 part by weight of butylphenylphenoxy-terminated oligomer (the number average repeating unit number m = 10) was added to 100 parts by weight of the polycarbonate. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Table 2 shows the evaluation results of the withstand voltage of the molded substrate (before dye coating), the water droplet contact angle, and the dye coating unevenness of the write-once type optical disc substrate.

Example 6 In a stainless steel 20 liter vertical stirring reactor equipped with a condenser, 2283 g (10.0 mol) of bisphenol A, 2290 g (10.7 mol) of diphenyl carbonate, and 0.0 as a catalyst were used.
0.7 ml of 1N sodium hydroxide (bisphenol A1
Nitrogen substitution was carried out by charging 7 × 10 ⁻⁶ mol) with respect to mol. This mixture was melted at 220 ° C. for 40 minutes to melt the raw material monomers, and then at 220 ° C./1.33×10 ⁴ Pa 60
Min, 240 ° C./2.00×10 ³ Pa, 60 minutes, 270
The reaction was carried out at 60 ° C / 66.7 Pa for 60 minutes. After completion of the reaction, the solution was fed to a twin-screw extruder with a gear pump, and butyl p-toluenesulfonate (a two-fold molar amount relative to sodium hydroxide used as a catalyst) was further added as a catalyst deactivator.
4-t-butylphenylphenoxy terminal oligomer obtained by interfacial polymerization method (number average repeating unit number m = 3)
0.5 parts by weight per 100 parts by weight of polycarbonate, 0.005 parts of nonion LT221 (polyoxyethylene sorbitan monolaurate, manufactured by NOF CORPORATION) as an antistatic agent, and stearic acid monoglyceride as a release agent. 0.02 part, AS32 as a heat stabilizer
0.005 parts of 9 (tris-nonylphenyl phosphite, manufactured by Asahi Denka Kogyo Co., Ltd.) was added and kneaded.

The strand emerging from the extruder was cut with a cutter into pellets. As a result, a polycarbonate composition having a viscosity average molecular weight of 15,400 was obtained. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Table 2 shows the evaluation results of the withstand voltage of the molded substrate (before dye coating), the water droplet contact angle, and the dye coating unevenness of the write-once type optical disc substrate.

[Example 7] A polycarbonate composition was obtained in the same manner as in Example 6 except that 0.03 parts by weight of the nonionic LT221 used in Example 6 was added to 100 parts by weight of the polycarbonate. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Molded substrate (before dye coating)
Table 2 shows the evaluation results of the withstand voltage, water drop contact angle, and dye coating unevenness of the write-once type optical disc substrate.

Example 8 A polycarbonate composition was obtained in the same manner as in Example 6 except that 0.06 parts by weight of the nonionic LT221 used in Example 6 was added to 100 parts by weight of the polycarbonate. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Molded substrate (before dye coating)
Table 2 shows the evaluation results of the withstand voltage, water drop contact angle, and dye coating unevenness of the write-once type optical disc substrate.

[Comparative Example 1] A polycarbonate was obtained in the same manner as in Example 1 except that the oligomer and the antistatic agent Nonion LT221 were not added. Table 2 shows the viscosity average molecular weight of the obtained polycarbonate composition, the proportion of alkylphenoxy groups in the oligomer, the content of the oligomer, and the total amount of the oligomer having the number of repeating units n of the oligomer of 2 to 4. Also, a write-once optical disc was prepared in the same manner as in Example 1 using the composition. Molded substrate (before dye coating)
Table 2 shows the evaluation results of the withstand voltage, water drop contact angle, and dye coating unevenness of the write-once type optical disc substrate.

[0100]

[Table 2]

[0101]

INDUSTRIAL APPLICABILITY The write-once type optical disc substrate and the write-once type optical disc using the polycarbonate composition of the present invention have a fundamentally improved electrostatic resistance and can be improved in dye coating property.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI theme code (reference) G11B 7/24 526 G11B 7/24 526G 526R 7/26 521 7/26 521 (72) Inventor Ryuji Uchimura Fukuoka Kurosaki Shiroishi 1-1, Yawatanishi-ku, Kitakyushu, Japan Mitsubishi Chemical Co., Ltd. (72) Inventor Toshimitsu Kurosaki Shiroishi 1-1, Yawatanishi-ku, Kitakyushu, Kitakyushu City, Fukuoka (72) Inventor Shigeo Higashi Kitakyushu, Fukuoka 1-1 Kurosaki Shiroishi, Hachimansai-ku, Yokohama-shi (72) Inventor Masaya Ueda 5-6-2 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Sanryo Engineering Plastics Corporation F-term (reference) 4J002 AA01X CG00W CG00X GS02 4J029 AA10 AB01 AC01 AD01 AE05 BB10A BB12A BB12B BE05A BF13 BG07X BG08X BH02 DB07 DB11 D B13 KE11 5D029 JA04 JB21 KA07 KA26 5D121 AA01 EE22

Claims (16)

[Claims] 1. A polycarbonate obtained by (a) a transesterification method, and (b) an ester bond in the molecule,
It has a carbonate bond, an amide bond, or a urethane bond, has an aromatic hydrocarbon group substituted with at least one alkyl group at the molecular end, and has a molecular weight of 300.
A polycarbonate composition comprising a compound of about 8000. 2. The polycarbonate composition according to claim 1, wherein the compound (b) is a compound represented by the following formula (1A). [Chemical 1] (In Formula (1A), G ¹ is a hydrogen atom or Ar ¹ -Q ² -CO
Represents-. However, Ar ¹ represents an aromatic hydrocarbon group substituted with at least one alkyl group. G ² is -Q ¹ -W
¹ -Q ² -H, or, Ar ² -Q ¹ - represents a. However, Ar ² represents an aromatic hydrocarbon group substituted with at least one alkyl group. Q ¹ is a single bond, —O—, or —NH.
Represents-, Q ² represents -O- or -NH-, and W ¹ represents a divalent group having 6 to 50 carbon atoms. N is 1 to 30
Represents the integer. ) 3. The polycarbonate composition according to claim 1, wherein the compound (b) is a compound represented by the following formula (1B). [Chemical 2] (In the formula (1B), G ¹ is a hydrogen atom or Ar ¹ —O—CO—
Represents However, Ar ¹ represents an aromatic hydrocarbon group substituted with at least one alkyl group. G ² is [Chemical 3] Alternatively, it represents Ar ² —O—. However, Ar ² represents an aromatic hydrocarbon group substituted with at least one alkyl group. In formula (2), W ² is a single bond, an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms, or 5 to 1 carbon atoms.
5 cycloalkylene group, a cycloalkylidene group having 5 to 15 carbon atoms, or -O-, -S-, -CO-, -SO.
-, - SO ₂ - those selected from the group consisting of divalent groups represented by, Y and Z are halogen or 1 carbon atoms
6 represents a hydrocarbon group. p and q are integers of 0 to 2, and Y and Z and p and q may be the same or different. Moreover, n represents the integer of 1-30. ) 4. The polycarbonate composition according to claim ^2, wherein Ar ¹ and Ar ² are groups represented by the following formula (5A). [Chemical 4] (In formula (5A), R ^{1 to} R ⁵ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, provided that R ^{1 to} R ^{5 are}
Except when all are hydrogen atoms. ) 5. The polycarbonate composition according to claim 4, wherein Ar ¹ and Ar ² are tertiary butylphenyl groups. 6. The polycarbonate according to claim 2, wherein the proportion of aromatic hydrocarbon groups substituted with at least one alkyl group in the total molecular terminals of compound (b) is 80 mol% or more. Composition. 7. In the formula (1A) or (1B),
The number average repeating unit number (m) is 20 or less.
7. The polycarbonate composition according to any one of 6 to 6. 8. The polycarbonate according to claim 1, wherein the content of the compound (b) is 0.01 to 20 parts by weight with respect to 100 parts by weight of the polycarbonate (a).
Composition. 9. The content of the oligomer having 2 to 4 repeating units n in the formula (1A) or (1B) in the compound (b) is 0.02 with respect to 100 parts by weight of the polycarbonate (a). The polycarbonate composition according to any one of claims 1 to 7, which is -15 parts by weight. 10. The polycarbonate composition according to any one of claims 2 to 9, wherein the compound (b) is obtained by an interfacial polymerization method. 11. The polycarbonate composition according to claim 1, which further comprises (c) an antistatic agent. 12. The polycarbonate composition according to claim 11, wherein the antistatic agent is a polyoxyethylene fatty acid ester. 13. The polycarbonate 100 as the antistatic agent.
The polycarbonate composition according to claim 11 or 12, containing 0.001 to 0.1 part by weight based on parts by weight. 14. A write-once type optical disc substrate using the polycarbonate composition according to claim 1. 15. A write-once optical disc, which is obtained by applying a dye to the optical disc substrate according to claim 14. 16. A write-once optical disc, characterized in that a substrate for a write-once optical disc is obtained by injection-molding the polycarbonate according to any one of claims 1 to 13, and a dye is applied thereto by spin coating. Method.