JP2001338436A - Molding material for optical disk substrate and optical disk substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding material for an optical disk substrate having an improved hue, improved heat resistance, etc., and an optical disk substrate using the molding material. SOLUTION: The molding material uses an aromatic polycarbonate resin composition comprising a polycarbonate having a viscosity average molecular weight of 12,000-40,000 prepared by reacting an aromatic dihydroxy compound with a compound capable of introducing a carbonate bond. The composition has <=1,000 ppm specified cyclic oligomer content and the proportion of the cyclic oligomer content to the total oligomer content satisfy a specified relational expression.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk substrate molding material having improved hue, heat resistance and the like, and an optical disk substrate using the same.

[0002]

2. Description of the Related Art Polycarbonate resins are widely used in many fields as resins having excellent impact resistance, transparency, low water absorption and the like, and in particular, have recently been widely used as molding materials for optical disks. Optical discs are usually manufactured by injection molding, but it is necessary to transfer sub-micron-order pits and grooves (guide grooves) stamped in advance on a stamper, and to read and write signals of minute parts using a laser beam or the like. Therefore, there is a demand for a molding material having good fluidity and small optical distortion. However, polycarbonate resins generally have a high melt viscosity, tend to increase optical distortion during injection molding, and have poor transferability. Therefore, in order to use polycarbonate as a molding material for an optical disk substrate, it is necessary to improve the fluidity during molding, and to mold an optical disk, it is necessary to increase the molding temperature of polycarbonate. However, in molding at high temperature, there is a problem that coloring and silver are likely to occur due to decomposition of the polycarbonate resin and the like, and further, a release agent added for improving the releasability at the time of disk molding is also required.
Coloring and silver generation may be promoted. In order to solve these problems at the time of optical disk molding, Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 8-126119 proposes a molded product of a polycarbonate resin containing a phosphite, but does not provide sufficient thermal stability.

[0003]

The present invention relates to an aromatic polycarbonate molding material for an optical disk substrate having excellent color tone, heat resistance and the like, and an optical disk substrate. As further effects, the present invention also provides an aromatic polycarbonate molding material for an optical disk substrate with less occurrence of silver and an optical disk substrate using the same.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies on the color tone, heat resistance and the like of a polycarbonate resin in order to solve the above problems. The inventors have found that the use of a polycarbonate resin whose amount is reduced to a specific amount and a specific ratio or less can greatly improve color tone and heat resistance, and have completed the present invention. In addition, by blending a specific release agent with this polycarbonate and controlling the amount of fine powder in the pellet and the shape of the pellet, it is possible to significantly improve the release property and silver generation while maintaining the hue and heat resistance. Was found. That is, the present invention relates to a polycarbonate having a viscosity average molecular weight of 10,000 to 18,000, which is produced by reacting an aromatic dihydroxy compound with a compound capable of introducing a carbonic acid bond, wherein the content of the cyclic oligomer represented by the formula (I) is as follows: Is 1000 ppm or less, and the ratio to the total amount of the oligomers represented by the formulas (I), (II) and (III) satisfies the relational expression (1). A molding material is provided.

[0005]

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(In the formula (I), B is a hydrocarbon group having 1 to 15 carbon atoms which may be substituted by halogen, O, S, C
It is a divalent group selected from O, SO and SO ₂ . X represents a halogen atom, an aliphatic group or a substituted aliphatic group having 1 to 14 carbon atoms, an aromatic group or a substituted aromatic group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, and 6 carbon atoms.
And a monovalent group selected from oxyaryl groups of -18 to -18. m is an integer of 2 to 8, p is an integer of 0 to 4, and s is 0 or 1. X and p may be the same or different. )

[0007]

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(In the formula (II), A and A ′ are the same or different and each have an aliphatic group having 1 to 18 carbon atoms;
It represents a substituted aliphatic group, an aromatic group, or a substituted aromatic group. n
Is an integer of 1 to 7, and B, X, p and s have the same definition as in formula (I). )

[0009]

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(In the formula (III), A ″ represents an aliphatic group having 1 to 18 carbon atoms, a substituted aliphatic group, an aromatic group or a substituted aromatic group. N ′ represents an integer of 1 to 7, , X, p and s have the same definition as in formula (I).)

[0011]

(Equation 2)

(In the formula (1), [I], [II], [III]
Represents the content of the oligomer corresponding to each formula,
Mv represents the viscosity average molecular weight of the aromatic polycarbonate. )

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The aromatic polycarbonate according to the present invention can be produced by a known method such as an interfacial polycondensation method or a transesterification method using an aromatic dihydroxy compound and a compound capable of introducing a carbonic acid bond as raw materials. Among them, production by a transesterification method is preferred. Examples of the compound capable of introducing a carbonic acid bond include phosgene and carbonic acid diester. The carbonic acid diester is represented by the following formula (IV).

[0014]

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(In the formula (IV), A and A 'each have 1 to 1 carbon atoms.
18 aliphatic groups, substituted aliphatic groups, aromatic groups, or substituted aromatic groups, which may be the same or different. The carbonic acid diester represented by the above formula (IV) is, for example, dimethyl carbonate, diethyl carbonate, di-t-
Examples thereof include substituted diphenyl carbonates such as butyl carbonate, diphenyl carbonate, and ditolyl carbonate. Preferred are diphenyl carbonate and substituted diphenyl carbonate, and particularly preferred is diphenyl carbonate. These carbonate diesters may be used alone or in combination of two or more. Further, a dicarboxylic acid or a dicarboxylic acid ester may be used in an amount of preferably 50% or less, more preferably 30% or less, together with the compound capable of introducing a carbon bond as described above. Such dicarboxylic acids or dicarboxylic esters include terephthalic acid, isophthalic acid,
Diphenyl terephthalate, diphenyl isophthalate and the like are used. When such a carboxylic acid or a carboxylic acid ester is used in combination with a carbonic acid diester, a polyester carbonate is obtained. The aromatic dihydroxy compound as another raw material is represented by the formula (V).

[0016]

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(In the formula (V), B is a hydrocarbon group having 1 to 15 carbon atoms which may be substituted by halogen, or
It is a divalent group selected from O, S, CO, SO and SO ₂ . X is a halogen atom, an aliphatic group or a substituted aliphatic group having 1 to 14 carbon atoms, an aromatic group or a substituted aromatic group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, and 6 to 18 carbon atoms. A monovalent group selected from oxyaryl groups. p is an integer of 0 to 4, and s is 0 or 1
It is. X and p may be the same or different, respectively. The aromatic dihydroxy compound represented by the above formula (V) is, for example, 2,2-bis (4-hydroxyphenyl) propane [= bisphenol A], 2,2-bis (4-hydroxy-3,5-dimethyl) Phenyl) propane, 2,2-
Bis (4-hydroxy-3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5- Dibromophenyl) propane, 2,
2-bis (4-hydroxyphenyl) pentane, 2,
4'-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5
-Nitrophenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 3,3-bis (4-hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxy Phenyl) sulfone, 2,4′-dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) sulfide,
4,4′-dihydroxydiphenyl ether, 4,4 ′
-Dihydroxy-3,3'-dichlorodiphenyl ether, 4,4'-dihydroxy-2,5-diethoxydiphenyl ether and the like. Of these,
2-bis (4-hydroxyphenyl) propane [= bisphenol A] is preferred. In addition, these aromatic dihydroxy compounds can be used alone or in combination of two or more, and can also be used as a copolymer if necessary.

The mixing ratio of the carbonic acid diester to the aromatic dihydroxy compound is determined by the desired molecular weight of the aromatic polycarbonate and the amount of terminal hydroxyl groups. The amount of terminal hydroxyl groups depends on the thermal stability of the product polycarbonate,
It has a significant effect on hydrolysis stability, color tone, etc., and is preferably 1,000 ppm in order to have practical physical properties.
Or less, more preferably 800 ppm or less, and particularly preferably 700 ppm or less. In the case of a polycarbonate produced by a transesterification method, if the amount of terminal hydroxyl groups is too small, the molecular weight does not increase and the color tone deteriorates.
0 ppm or more is more preferable, and 300 ppm or more is particularly preferable. Therefore, it is common to use the carbonate diester in an equimolar amount or more with respect to 1 mole of the aromatic dihydroxy compound, preferably from 1.01 to 1.30 mol, particularly preferably from 1.01 to 1.20 mol. Used in When an aromatic polycarbonate is produced by the transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, but an alkali metal compound and / or an alkaline earth metal compound is mainly used, and a basic boron compound, a basic phosphorus compound,
It is also possible to use a basic compound such as a basic ammonium compound or an amine compound in combination. These catalysts may be used alone or in combination of two or more. The catalyst is used in an amount of 1 × 10 ^-9 to 1 × 10 ^-3 mol per 1 mol of the aromatic dihydroxy compound. Particularly, in the case of an alkali metal compound or an alkaline earth compound, usually 1 × 10 ⁻⁹ to 1 × 10 ⁻⁴ mol, preferably 1 × 10 ⁻⁸ to 1 × 10 ⁻⁵ mol per 1 mol of the aromatic dihydroxy compound. Used in the range, basic boron compounds, basic phosphorus compounds, basic ammonium compounds or basic compounds such as amine compounds,
1 × 10 ⁻⁹ to 1 mol of aromatic dihydroxy compound
It is used in an amount of 1 × 10 ⁻³ mol, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ mol. If the amount of the catalyst is less than these amounts, the polymerization activity required for producing a polycarbonate having a predetermined molecular weight and a terminal hydroxy group amount cannot be obtained. It is not preferable because the color tone is deteriorated, the heat resistance is reduced, the hydrolysis resistance is reduced, and the amount of foreign substances is increased due to the generation of gel.

As the alkali metal compound, lithium,
Inorganic alkali metal compounds such as sodium, potassium, rubidium and cesium hydroxides, hydrogen carbonates, carbonates, acetates, hydrogen phosphates and phenyl phosphates; organic acids such as stearic acid and benzoic acid; methanol And organic alkali metal compounds such as salts with alcohols such as ethanol, phenolic acid, and phenols such as bisphenol A. Examples of the alkaline earth metal compound include inorganic alkaline earth metal compounds such as beryllium, calcium, magnesium, strontium, barium hydroxide, hydrogen carbonate, carbonate, and acetate, organic acids, alcohols,
Organic alkaline earth metal compounds such as salts with phenols and the like can be mentioned. Specific examples of the basic boron compound include tetramethyl boron, tetraethyl boron, tetrapropyl boron, tetrabutyl boron, trimethylethyl boron, trimethylbenzyl boron, trimethylphenyl boron, triethylmethyl boron, triethylbenzyl boron, triethylphenyl boron, tributyl Sodium, potassium, lithium, calcium, magnesium, barium or strontium salts of benzylboron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, butyltriphenylboron, etc. Is mentioned. Examples of the basic phosphorus compound include triethylphosphine, tri-n-propylphosphine,
Examples include triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and quaternary phosphonium salts.

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, benzyltrimoxide Examples include phenylammonium hydroxide, methyltriphenylammonium hydroxide, and butyltriphenylammonium hydroxide. Examples of the amine compound 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. Of these catalysts, practically, alkali metal compounds, basic ammonium compounds, and basic phosphorus compounds are desirable, and alkali metal compounds are particularly desirable. The polycarbonate of the present invention uses the compound capable of introducing a carbon bond and the aromatic dihydroxy compound, and is usually produced using the above-mentioned transesterification catalyst, and has a viscosity average molecular weight of 10,000 to 18,000. If the viscosity average molecular weight is less than 10,000, the mechanical strength decreases,
If it exceeds 00, the moldability is undesirably reduced.

In the aromatic polycarbonate of the present invention, the total content of the cyclic oligomer represented by the formula (1) needs to be 1000 ppm or less, preferably 700 ppm or less, more preferably 550 ppm or less. When the amount of the cyclic oligomer exceeds 1000 ppm, the oligomer is colored, and heat resistance, hydrolysis resistance and the like are reduced. The reason for this is not necessarily clear, but it is presumed that the cyclic oligomer is rich in reactivity and easily produces a coloring component at high temperature or promotes hydrolysis. Further, in the present invention, the ratio of the amount of the cyclic oligomer (I) to the total amount of the cyclic oligomer (I) and the oligomers represented by the formulas (II) and (III) does not satisfy the following relational expression (1). No.

[0022]

(Equation 3)

(In the formula (1), [I], [II], [III]
Represents the content of the oligomer corresponding to each formula,
Mv represents the viscosity average molecular weight of the aromatic polycarbonate. Both the cyclic oligomers represented by the formula (I) and the linear oligomers represented by the formulas (II) and (III) are considered to be components formed during the production of polycarbonate, and The structure of the repeating unit in parentheses in the formula is derived from the aromatic dihydroxy compound used in the production of polycarbonate. The compounds represented by the terminal groups A, A 'and A "are derived from the terminal groups of the compound capable of introducing a carbonic acid bond represented by the formula (IV), and are obtained by interfacial polycondensation using phosgene. When the cyclic oligomer (I) is produced, it is derived from the terminal stopper used.
Above ppm, the properties are adversely affected. Further 1000
It has been found that even when the content of the cyclic oligomer (I) is less than ppm, if the proportion of the cyclic oligomer (I) exceeds the range of the above relational formula (1), physical properties are adversely affected. Reasons for worse physical properties are 100
Cyclic oligomer (I) as in the case of more than 0 ppm
This is probably because of high reactivity.

The mechanism of the formation of the cyclic oligomer (I) is not clear, but the heat history during the production of the polymer, the influence of the type and amount of the catalyst, the concentration of the monomer during the production of the polymer and the concentration of the aromatic hydroxy compound produced as a by-product, etc. The amount of generation changes due to the influence.
Generally, in order for a certain molecular chain to become a cyclic body, the terminal groups of the molecular chain need to react with each other. However, this is usually difficult to occur, and generally, in the early stage of polymerization, end groups between adjacent molecules react with each other, and the polymerization proceeds. However, when the polymerization proceeds and the ratio of terminal groups in the system changes, it is considered that the reaction between molecules is reduced and the reaction in the molecule is likely to occur. In particular, when a high temperature is maintained in a state where the number of terminal hydroxyl groups is small, a cyclic oligomer is easily formed. Therefore, it is preferable that the ratio of terminal hydroxyl groups is not extremely reduced during the production. For the purpose of merely reducing the content of the cyclic oligomer (I), the extraction treatment can be carried out with a solvent having a weak polycarbonate-dissolving power, such as hexane, heptane, methanol and acetone. However, in the extraction operation, the amount of the linear oligomer other than the cyclic oligomer is also reduced, and the ratio of the amount of the cyclic oligomer in the total amount of the oligomer does not change. There are many. Further, the heat resistance may not be improved due to the influence of the residual solvent due to the extraction operation, which is not preferable. The content of the oligomer represented by the formula (I), the formula (II) or the formula (III) is measured by, for example, gel permeation chromatography (GPC), high performance liquid chromatography (HPLC), mass spectrum, NM
It can be measured using R or the like. However, since it is generally necessary to separate a high molecular weight part and a low molecular weight part, MAL
DI-TOFMS (Matrix Assisted Lazer Desorption)
It is preferable to collectively measure from the high molecular weight part to the low molecular weight part using a measuring instrument such as Ionization Time of Flight Mass Spectrometory.

In the production of the polycarbonate of the present invention, the ester exchange reaction using the above-mentioned raw materials is carried out at 100 to 320 ° C.
At normal temperature or reduced pressure to carry out a melt polycondensation reaction while removing by-products such as aromatic hydroxy compounds. The melt polycondensation can be carried out batchwise or continuously, but in the present invention, it is preferably carried out continuously in view of product stability and the like. The reaction is usually carried out in two or more stages in which the temperature and pressure conditions are changed. The reaction temperature of each step is not particularly limited as long as the polymer is in a molten state within the above range, and the reaction time is also appropriately determined depending on the degree of progress of the reaction, but may be 0.1 to 10 hours. preferable. These conditions are determined in view of the molecular weight, hue and cyclic oligomer content of the polymer. Specifically, the first stage reaction is carried out at a temperature of 140 to 260 ° C., preferably 180 to 240 ° C. for 0.1 to 5 hours, preferably 0.5 to 3 hours under normal pressure or reduced pressure. Then, the reaction temperature was raised while increasing the degree of pressure reduction of the reaction system, and finally 240 to 3 mm 2 under a reduced pressure of 2 mmHg or less.
The polycondensation reaction is performed at a temperature of 20 ° C. An effective method as a production method for reducing the content of the cyclic oligomer is
In particular, in the final polymerization step in which the molecular weight is increased by 5% or more, the reaction is carried out at 250 ° C. or more, particularly 260 ° C. or more, under such conditions that the proportion of terminal hydroxyl groups at the inlet of the polymerization apparatus used in the reaction becomes 100 ppm or more. The polymerization is preferably performed, and more preferably at 200 ppm or more. The activation energy for the formation of the cyclic oligomer is high, and the higher the temperature, the more rapidly it is generated. Therefore, the polymerization temperature in the final stage is preferably 310 ° C. or lower. If the amount of the catalyst is too large,
It is considered that the carbonate bond is easily activated, and a reaction between the carbonate terminals which usually does not occur easily occurs, so that a cyclic oligomer is also easily formed. Controlling the conditions of each of these reaction tanks so as not to fluctuate as much as possible can suppress the amount of the cyclic oligomer.

The apparatus to be used may be any of a tank type, a tube type, and a tower type, and includes a vertical polymerization tank equipped with various stirring blades, a horizontal single-axis or horizontal two-axis polymerization tank. Etc. can be used. The atmosphere in the apparatus is not particularly limited, but from the viewpoint of the quality of the polymer, the polymerization is preferably performed in an inert gas such as nitrogen gas at normal pressure or reduced pressure. One example of such a manufacturing method is schematically shown in FIG. After completion of the polymerization, the produced aromatic polycarbonate is usually recovered as pellets.In this case, in order to remove low molecular weight components such as monomers and by-products remaining in the resin, the aromatic polycarbonate may be passed through a vented extruder. It is possible. The extruder conditions at which the temperature is usually highest in the production process should be mild conditions in order to keep the generation of cyclic oligomers low. When the temperature is increased while the catalyst is active, a cyclic oligomer is formed. Therefore, it is preferable to deactivate the catalyst using a suitable deactivator. When a catalyst, particularly an alkali metal compound catalyst, is used, a compound that neutralizes the catalyst, for example, a sulfur-containing acidic compound or a derivative formed therefrom is used as a catalyst deactivator in the transesterification polycarbonate. The amount is preferably 0.5 to 10 equivalents, preferably 1 to the alkali metal of the catalyst.
5 to 5 equivalents, usually 1 to 100 ppm, preferably 1 to 20 ppm based on the produced polycarbonate.
Add within the range. Examples of sulfur-containing acidic compounds or derivatives formed therefrom are sulfonic acid, sulfinic acid, sulfuric acid or esters thereof, and specifically, dimethyl sulfate, diethyl sulfate, p-toluenesulfonic acid, its methyl, ethyl, Butyl, octyl and phenyl esters, benzenesulfonic acid, its methyl, ethyl, butyl, octyl, phenyl and dodecyl esters, benzenesulfinic acid, toluenesulfinic acid,
And naphthalenesulfonic acid. Of these compounds, esters of p-toluenesulfonic acid or esters of benzenesulfonic acid are preferred, and two or more of these compounds may be used.

The sulfur-containing acidic compound or a derivative formed therefrom can be added to the polycarbonate by any method. For example, a sulfur-containing acidic compound or a derivative formed therefrom can be added to a polycarbonate in a molten or solid state directly or diluted with a diluent, and dispersed. Specifically, it can be supplied and mixed in a polycondensation reactor, a transfer line from the reactor, or an extruder. Further, after mixing with polycarbonate pellets, flakes, powders and the like generated by a mixer or the like, the mixture can be supplied to an extruder and kneaded. In addition, when performing a reduced pressure treatment by venting in an extruder, or when adding water, further, an antioxidant selected from a hindered phenol compound and a phosphorus compound,
When adding other heat stabilizers, mold release agents, dyes, pigments, ultraviolet absorbers, antistatic agents, antifogging agents, organic / inorganic fillers, etc., the addition and treatment of these various additives May be performed simultaneously with the sulfur-containing acidic compound or the derivative formed therefrom, but it is preferable to add the sulfur-containing acidic compound or the derivative formed therefrom prior to addition or treatment thereof, and further knead the compound. .

In the present invention, the release agent is used in an amount of 0.00 parts by weight based on 100 parts by weight of the specific aromatic polycarbonate.
1 to 5 parts by weight can be blended. Preferred release agents used in the present invention include at least one compound selected from esters of an aliphatic carboxylic acid having 6 to 30 carbon atoms and an alcohol having 30 or less carbon atoms. Aliphatic carboxylic acids include saturated or unsaturated aliphatic carboxylic acids, dicarboxylic acids or tricarboxylic acids. Here, the aliphatic carboxylic acid also includes an alicyclic carboxylic acid. Among these, preferred aliphatic carboxylic acids are mono- or dicarboxylic acids having 6 to 36 carbon atoms, and more preferred are aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms. Specific examples of such aliphatic carboxylic acids include:
Palmitic acid, stearic acid, valeric acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotinic acid, melysin, tetraliacontanic acid, montanic acid, glutaric acid, adipic acid, azelaic acid, etc. Can be mentioned. Examples of the alcohol which reacts with the aliphatic carboxylic acid to form an ester include a saturated or unsaturated monohydric alcohol, a saturated or unsaturated polyhydric alcohol, and the like. These alcohols may have a substituent such as a fluorine atom. Among these alcohols, monovalent or polyvalent saturated alcohols having 30 or less carbon atoms are preferable, and aliphatic saturated monohydric alcohols or polyhydric alcohols having 30 or less carbon atoms are more preferable. Here, the aliphatic includes an alicyclic compound. Specific examples of these alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol And the like. These ester compounds of aliphatic carboxylic acids and alcohols may contain aliphatic carboxylic acids and / or alcohols as impurities, or may be mixtures of a plurality of compounds. In the ester of an aliphatic carboxylic acid and a polyhydric alcohol,
It may be a full ester or a partial ester.
Specific examples of the ester of an aliphatic carboxylic acid and an alcohol include beeswax (a mixture mainly composed of myricyl palmitate), stearyl stearate, behenyl behenate, octyldodecyl behenate, glycerin monopalmitate, and glycerin monoester. Examples thereof include stearates, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, and pentaerythritol tetrastearate.

Particularly preferred among these release agents are esters of aliphatic carboxylic acids and alcohols. Among them, beeswax, behenyl behenate, glycerin monostearate, pentaerythritol monostearate and pentaester are particularly preferred. Erythritol distearate and pentaerythritol tetrastearate are preferred. The amount of the release agent is 0.001 to 5 parts by weight, preferably 0.005 to 0.4 parts by weight, based on 100 parts by weight of the aromatic polycarbonate. If the amount is less than 0.001 part by weight, the effect is not sufficient, and if the amount is more than 5 parts by weight, there is a problem that heat resistance is reduced and silver is generated.

In the present invention, the specific phosphorus compound is
The above specified aromatic polycarbonate 1 as an antioxidant
0.0001 to 1 part by weight can be blended with respect to 00 parts by weight. That is, the phosphorus compound that can be used in the present invention is a phosphite in which at least one ester in the phosphite is esterified with phenol and / or phenol having at least one alkyl group having 1 to 25 carbon atoms. Phosphoric acid or tetrakis (2,4
-Di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite. Specific examples of the phosphite include 4,4'-butylidene-bis (3-methyl-6-t-butylphenyl-di-tridecyl) phosphite and 1,1,3-tris (2-methyl-4 -Ditridecyl phosphite-5-t
-Butylphenyl) butane, trisnonylphenyl phosphite, dinonylphenylpentaerythritol diphosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-butylphenyl) Pentaerythritol diphosphite, di (2,
6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2′-ethylidene-bis (4,6-ditert-butylphenyl) fluoride phosphite, 2,2′-methylene-bis (4,6-di-
(t-butylphenyl) octyl phosphite, bis (2,4-dicumylphenyl) pentaerythritol diphosphite, a phosphite composed of monononylphenol and dinonylphenol, and a hindered phenol represented by the formula (V) Phosphite esters and the like can be mentioned. In the present invention, tetrakis (2,4-di-t-butylphenyl) -4,4′-biphenylene-di-phosphonite or tris (2,4-di-t-butylphenyl) phosphite is used as the phosphorus compound. , 2,2'-methylene-bis (4,6-di-t-butylphenyl) octyl phosphite and phosphorous acid are preferred.

The compounding amount of at least one selected from the phosphorus compounds is 0.0001 to 1 part by weight, preferably 0.0001 to 0.4 part by weight, per 100 parts by weight of the aromatic polycarbonate. It is. If the amount is less than 0.0001 part by weight, the effect is not sufficient. If the amount is more than 1 part by weight, there is a problem that hydrolysis resistance is deteriorated. In addition, when the release agent and the phosphorus compound are used in combination, the compounding ratio can be arbitrarily determined.In addition, whether one of them is used or used in combination is appropriately determined depending on molding conditions and the like. It is determined. There are no particular restrictions on the timing and method of addition of the release agent and / or phosphorus compound. For example, when the polycarbonate is produced by a transesterification method, during the polymerization reaction or at the end of the polymerization reaction,
Furthermore, regardless of the polymerization method, the polycarbonate can be added in a molten state such as during kneading of the polycarbonate or the like, but it is also possible to knead with an extruder or the like after blending with the solid state polycarbonate such as pellets or powder. . Further, particularly in the transesterification polycarbonate, in order to suppress the decomposition of the release agent and / or the phosphorus compound, the polymerization catalyst is used with the above-mentioned sulfur-containing acidic compound or a catalyst deactivator such as a derivative formed therefrom. It is preferable to add it after deactivation.

As a method of addition, the release agent and / or the phosphorus compound can be directly mixed or kneaded with the polycarbonate. However, the release agent and / or the phosphorus compound may be dissolved in an appropriate solvent, or may be dissolved in a small amount of a polycarbonate or other resin. It can also be added as a concentration master batch. When using a phosphorus compound and a release agent together,
These can be separately added to the polycarbonate, but can also be added simultaneously. The aromatic polycarbonate resin composition of the present invention may further include ordinary heat stabilizers such as hindered phenols and sulfur, ultraviolet absorbers, coloring agents, antistatic agents, slip agents, antiblocking agents, lubricants, Additives such as clouding agents, natural oils, synthetic oils, waxes, organic fillers and inorganic fillers may be added. Such an additive can be added to a resin in a molten state, or can be added by re-melting a resin once pelletized.

Furthermore, in the present invention, the content of the powdery polymer having an average particle size of 0.5 mm or less in the aromatic polycarbonate pellets is preferably 2.0% by weight or less. If the powdery polymer having an average particle size of 0.5 mm or less is mixed, plasticization in a molding machine becomes uneven, and unmelted resin is mixed in the plasticized resin, or in the molten resin. Entraps air and becomes silver in the molded product. Therefore,
When the content of the powdery polymer is more than 2.0% by weight,
Unmelted material is generated, and generation of silver is increased. The content of the powdery polymer is more preferably 1.0% by weight or less. The aromatic polycarbonate resin composition used in the present invention as described above is usually used in the form of pellets. The pellets may be produced by a hot cut method in the air or in water, but are usually produced by a cold cut method such as a strand cut method as described below. That is, the resin in a molten state is extruded from the die as one to several strands in the extruder. This is cooled and solidified in a cooling water tank and cut by a strand cutter to produce. The pellet shape produced in this way is usually an elliptical column (here, it is not necessary to be strictly elliptical, but also includes, for example, a column). In order to reduce the content of the powdery polymer in the pellets to 2.0% by weight or less, the cutting conditions when cutting with a strand carter are optimized, and fine powder is removed by a vibration sieve or water washing. Can be achieved by doing It is also important to suppress the generation of fine powder due to the collision between the pellets or the pellets in the drying, blending, and packaging steps after pelletization and in the transport line connecting these steps.

The powdery polymer content was measured by weighing 100 to 200 g of polycarbonate pellets,
Place in a 0 mesh stainless steel wire mesh container, 300 ~ 40
The pellet is washed by shaking well in 0 ml of methanol and the powder is separated in methanol. This washing solution is filtered off with a G4 glass filter. This operation is repeated until no suspended matter is found in methanol. Normal 4
The operation is completed after 5 operations. The residue collected by filtration is weighed after drying, and the residue weight is used as the powder weight. The average particle size of the collected powder was measured using an optical microscope,
For 000 powder particles, the maximum width of the particles (when the projected image of the particles is sandwiched by two parallel lines in the plane, the maximum distance) is measured, and the arithmetic average is taken.
The pellet shape of the molding material for an optical disc substrate in the present invention is such that the average value of the pellet length is 2.50 mm to 3.5.
mm, and the average value of the major axis of the cross-section ellipse is 2.60.
３3.20 mm and 70% of the pellets
The above is preferably within the range of the average value of the length ± 0.08 mm and the average value of the long diameter ± 0.12 mm. The length of the pellet is desirably adapted to the dimensions of the cylinder and screw of the injection molding machine for disk molding, and the average length is in the range of 2.5 to 3.5 mm. If the length of the pellets is out of this range, biting into the screw becomes worse, which is not preferable. The same applies to the major axis of the pellet. Furthermore, the distribution preferably lies within a certain narrow range. Such pellets have an increased plasticizing efficiency in a molding machine, and can be plasticized with little unmelted material or air entrainment even during high-speed plasticization, thereby suppressing generation of silver in a molded product.

Here, the length of the pellet is the distance between the cross sections cut by the strand cutter, which corresponds to the height of the pellet in the shape of the elliptic cylinder. The length and diameter of the pellet are almost determined by the number of revolutions of the blade of the strand cutter, the winding speed, and the discharge amount of the extruder.If the discharge amount is unstable or the cooling bath temperature is unstable, The distribution of pellet length and major diameter becomes wider. In the present invention, the length and the major axis of the pellet are measured with a vernier caliper to measure the length and the major axis of 150 or more pellets, and the average of the length of 150 points (measurement points) or more and the average ± 0.08 mm are obtained. Number of pellets in the range (measurement points)
And the ratio was calculated. With respect to the major axis, measurement points falling within the range of the average value ± 0.12 mm were obtained in the same manner, and the ratio was calculated. By using a pellet having such a pellet shape in a specific region, it is possible to obtain an optical disc substrate that is more excellent in improving releasability and suppressing generation of silver.

[0036]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. In the following examples, the production of the aromatic polycarbonate was performed using the steps as shown in FIG. Also,
The analysis and the like in the following examples were performed by the following measurement methods. (1) Viscosity average molecular weight (Mv) The intrinsic viscosity [η] at 20 ° C. in methylene chloride was measured using an Ubbelohde viscometer, and determined by the following equation.

[0037]

[Η] = 1.23 × 10 ⁻⁴ × (Mv) ^0.83

(2) Oligomer Content MALDI-TOFMS (manufactured by Finniganmat: VI
SION2000; laser (N ₂ laser = 337N
m) and the measured mass range (m / z = 0 to 35000)) were used for the measurement. 0.10 g of polycarbonate in 10 ml of dichloromethane and tris (3,5-di-t
-Butyl-4-hydroxybenzyl) isocyanurate (0.01 g) and a matrix solution of 2,4,6-trihydroxyacetophenone (80 mg) in tetrahydrofuran (THF) (1 ml) were prepared. The matrix solution was mixed at a volume ratio of 1:
The mixture was mixed at a ratio of 1 and used as a sample solution. (3) Initial color tone After drying the resin composition at 120 ° C. for 4 hours, a 12 cm diameter C was obtained at a cylinder temperature of 320 ° C., a mold temperature of 80 ° C., and a molding cycle of 4 seconds using DISK3 manufactured by Sumitomo Heavy Industries, Ltd.
A disk substrate for D was formed. After the formed CD disk substrate was pulverized, it was put into a 10 mm thick glass cell as a 10% by weight methylene chloride solution, and the YI value was measured with a spectral colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd., SE2000). It was shown that the larger the YI value, the more colored. (4) Retention stability (heat resistance test at 320 ° C.) After drying the resin composition at 120 ° C. for 4 hours, a resin temperature of 320 ° C., a mold temperature of 80 ° C. and a molding cycle of 600 seconds by DISK3 manufactured by Sumitomo Heavy Industries, Ltd. Under the conditions, a disk substrate for CD having a diameter of 12 cm was formed. After the formed CD disk substrate was pulverized, it was put into a 10 mm thick glass cell as a 10% by weight methylene chloride solution, and the YI value was measured with a spectral colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd., SE2000). The difference from the initial hue is shown as ΔYI value.

(5) Terminal hydroxyl group content Colorimetric determination was performed by the titanium tetrachloride / acetic acid method (the method described in Macromol. Chem. 88 215 (1965)). (6) Measurement of amount of powdered polymer After weighing 100 to 200 g of polycarbonate pellets, they were placed in a 30-mesh stainless steel wire mesh container, and
Shake well in ~ 400 ml of methanol to wash the pellet and separate the powder into methanol. This washing solution is filtered off with a G4 glass filter. This operation is repeated until no suspended matter is found in methanol.
Normally, the operation is completed after four to five operations. The residue collected by filtration was dried and then weighed, and the residue weight was used as the powder weight. The average particle size of the collected powder was measured using an optical microscope.
The maximum width of the particles (meaning the maximum distance between two parallel lines in the plane of the projected image of the particles) was measured for 00 to 1000 powder particles, and the arithmetic average was taken. (7) Pellet length and major axis measurement The length and major axis of 150 pellets were measured with a caliper,
Average value of length of 150 points (measurement points) and average value ± 0.0
The number of pellets (measurement points) falling within the range of 8 mm was determined and the ratio was calculated. Average value ±
Measurement points falling within the range of 0.12 mm were determined. (8) Silver generation rate A 12 cm diameter CD was prepared by using DISK3 manufactured by Sumitomo Heavy Industries, Ltd. at a cylinder temperature of 320 ° C and a mold temperature of 80 ° C.
The disk substrate for 100 shots was formed, and the disk substrate where silver streaks occurred was visually observed, and the silver generation rate was determined from the ratio of the disk substrates where silver streaks occurred. (9) Release Property The surface shape of the CD disk substrate molded under the above conditions was observed with an atomic force microscope (Olympus NV2100), and the presence or absence of deformation of the disk substrate surface during release was examined.

Examples 1-4 In a nitrogen gas atmosphere, bisphenol A (B
PA) and diphenyl carbonate (DPC) are melt-mixed at a fixed molar ratio (DPC / BPA = 1.045),
The polymer is continuously supplied through a raw material introduction tube heated to 135 ° C. under a normal pressure and a nitrogen atmosphere into a first vertical stirred polymerization tank controlled at 220 ° C., and the polymer at the bottom of the tank is controlled so that the average residence time is 70 minutes. By controlling the valve opening provided on the discharge line,
The liquid level was kept constant. Simultaneously with the start of the supply of the raw material mixture, cesium carbonate in an aqueous solution was added as a catalyst in an amount of 6 × 10 6 per mol of bisphenol A.
^It was continuously supplied at a flow rate of ^-7 mol. The polymerization liquid discharged from the bottom of the tank was continuously and continuously supplied to the second, third, and fourth vertical polymerization tanks. During the reaction, the liquid level was controlled so that the average residence time of each tank was a predetermined time as shown in Table 1 below, and at the same time, phenol produced as a by-product was distilled off. Table 1 below shows the polymerization conditions in each reaction tank, the monomer content, and the like, from the vertical second polymerization tank to the vertical fourth polymerization tank. 50k
The polycarbonate obtained continuously at a production rate of g / Hr is kept in a molten state, a thermometer for measuring the internal temperature is installed in the kneading section, and a twin screw extruder equipped with a three-stage vent port (Kobe Steel ( Ltd., screw diameter 0.046m, L / D =
36), and 5 p-butyl p-toluenesulfonate
After adding pm, adding water and volatilizing the water and the monomer component, the mixture was pelletized. Extruder conditions: discharge rate = 5
0 kg / hr, rotation speed = 150 rpm, maximum resin temperature =
260 ° C. The viscosity average molecular weight of the obtained polycarbonate was 15900, and the cyclic oligomer content was 53
0 ppm, and the ratio of the amount of the cyclic oligomer calculated by the formula (1) was 8.2%. The additives shown in Table 1 were blended with the polymer, extruded into a strand at a temperature of 280 ° C. with a 40 mmφ extruder, and then cut for pelletization to obtain pellets. After removing the fine powder from the obtained pellets with a vibrating sieve, the amount of the powdery polymer, the length of the pellets, the measurement of the major axis of the pellets, and the disc substrate and 3
A plate having a thickness of mm was formed, and various evaluations such as retention stability were performed. The results are summarized in Table 1.

Comparative Examples 1 to 3 In Example 1, the polymerization conditions were changed as shown in Table 1, and the production was carried out in the same manner to obtain a polycarbonate. Using this polycarbonate, in Comparative Example 2, the additives shown in Table 1 were blended and mixed, and those of Comparative Examples 1 and 3 were blended without additives, and kneaded at a temperature of 280 ° C. with a 40 mmφ extruder to produce pellets. In Comparative Examples 1 and 2, the fine powder was not removed by the vibrating sieve from the pellet. In Comparative Example 3, the fine powder was removed in the same manner as in Example 1, and various evaluations and measurements similar to those in Example 1 were performed. Was. The results are summarized in Table 1.

[0042]

[Table 1]

[0043]

The optical disk substrate using the aromatic polycarbonate molding material for an optical disk substrate of the present invention is excellent in hue, heat resistance, and suppression of generation of silver.

[Brief description of the drawings]

FIG. 1 shows a flow sheet showing one example of a production method for obtaining a polycarbonate of the present invention.

[Explanation of symbols]

1. Raw material mixing tank 2. 2. Vertical polymerization tank Stirrer blade 4. 4. By-product discharge pipe Horizontal polymerization tank 6. Stirring blade 7. Catalyst introduction pipe

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 69/00 C08L 69/00 (72) Inventor Michio Nakata 5-6-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa 3 Ryo Engineering Plastics Co., Ltd. Technology Center (72) Inventor Masaya Ueda 5-6-1 Higashi-Yawata, Hiratsuka-shi, Kanagawa Mitsui Engineering Plastics Co., Ltd. Technology Center F-term (reference) 4F070 AA50 AB22 AC43 AC55 AC04 AD04 AE03 AE17 DA50 DA55 DB08 DB09 DB10 DC01 DC07 DC11 4J002 CG011 CG012 CG021 CG022 DH027 EH036 EH046 EH076 EH086 EW067 EW127 GS02 4J029 AA08 AA09 AA10 AE05 BB13A BB13B02B14B02B14B02B14B02B14B02A

Claims (6)

[Claims] 1. A polycarbonate having a viscosity average molecular weight of 10,000 to 18,000, produced by reacting an aromatic dihydroxy compound with a compound capable of introducing a carbonic acid bond, comprising a cyclic oligomer represented by the formula (I). The use of an aromatic polycarbonate resin composition whose amount is 1000 ppm or less and whose ratio to the total amount of the oligomers represented by the formulas (I), (II) and (III) satisfies the relational expression (1). Characteristic molding material for optical disc substrates. Embedded image (In the formula (I), B is a hydrocarbon group having 1 to 15 carbon atoms which may be substituted with halogen, a divalent group selected from O, S, CO, SO and SO _2. X is a halogen. An atom, an aliphatic group having 1 to 14 carbon atoms or a substituted aliphatic group,
It represents a monovalent group selected from an aromatic group or a substituted aromatic group having 6 to 18 carbon atoms, an oxyalkyl group having 1 to 8 carbon atoms, and an oxyaryl group having 6 to 18 carbon atoms. m is 2
An integer of 8, p is an integer of 0 to 4, and s is 0 or 1. X and p may be the same or different. ) (In the formula (II), A and A ′ are the same or different and each represent an aliphatic group having 1 to 18 carbon atoms, a substituted aliphatic group, an aromatic group, or a substituted aromatic group. Integers of 1 to 7, B, X, p and s have the same definition as in formula (I). (In the formula (III), A ″ represents an aliphatic group having 1 to 18 carbon atoms, a substituted aliphatic group, an aromatic group, or a substituted aromatic group. N ′
Is an integer of 1 to 7, and B, X, p and s have the same definition as in formula (I). ) (Equation 1) (In the formula (1), [I], [II], and [III] each represent the content of the oligomer corresponding to each formula, and Mv represents the viscosity average molecular weight of the aromatic polycarbonate.) 2. An at least one ester selected from an ester of an aliphatic carboxylic acid having 6 to 30 carbon atoms and an alcohol having 30 or less carbon atoms, based on 100 parts by weight of the polycarbonate.
2. The molding material for an optical disk substrate according to claim 1, wherein 0.001 to 5 parts by weight of a release agent is blended. 3. A mixture of 100 parts by weight of polycarbonate and phosphorous acid or a derivative thereof, and tetrakis (2, 3).
3. The composition of claim 1, wherein at least one phosphorus compound selected from the group consisting of 4-di-t-butylphenyl) -4,4'-biphenylene-di-phosphonite is added in an amount of 0.0001 to 1 part by weight. The molding material for an optical disk substrate according to the above. 4. The molding material for an optical disk substrate according to claim 1, wherein the content of the powdery polymer having an average particle size of 0.5 mm or less is 2.0% by weight or less. 5. The average length of the pellets is 2.50 mm.
ペ レ ッ ト 3.5 mm, the average value of the major axis of the cross-sectional ellipse is in the range of 2.60-3.20 mm, and 70% or more of the pellets have the average value of the length ± 0.08 mm and the major axis. The molding material for an optical disk substrate according to any one of claims 1 to 4, wherein the molding material is contained within a range of ± 0.12 mm. 6. An optical disk substrate using the optical disk substrate molding material according to claim 1. Description: