JP2001089559A - Polycarbonate resin, substrate using the same for optical information recording medium, and optical information recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polycarbonate resin improved in hue and suitable for substrate that supports a transfer type optical recording medium, e. g. optical disk. SOLUTION: This polycarbonate resin is obtained by the reactions of reactants containing diphenol, a stock material for carbonate, and terminal sealant composed of p-long chain substituted phenol (para-compound), wherein content of o-long chain substituted phenol (ortho-compound) as an impurity in the sealant satisfies the following relationship: ortho-compound content/para- compound content plus ortho-compound content ×106<10,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate resin, and more particularly to a polycarbonate resin suitably used for a substrate for a transfer-type optical information recording medium such as an optical disk. The present invention further relates to an optical information recording medium substrate using the above polycarbonate resin and an optical information recording medium using the same.

[0002]

2. Description of the Related Art Optical recording that can be recorded and reproduced without contact is
Compared to conventional magnetic recording, it has a feature of being resistant to scratches and dirt, and greatly contributes to an increase in storage capacity. The recording medium of this system is formed by forming an information recording layer on a transparent substrate such as a polycarbonate resin. Polycarbonate resin is a suitable material as a substrate material of the above-mentioned information recording medium because it has excellent heat resistance during melt molding, small dimensional change after molding, and excellent mechanical properties. In recent years, when a polycarbonate resin is used in this field, the space and depth of the groove transferred to the transparent substrate are shifting to narrower and deeper directions as the storage capacity is increased. As a result, molding at a higher molding temperature or mold temperature of the polycarbonate resin has always been performed. However, due to the heat resistance of the resin, low-temperature volatiles are likely to be generated when molded at higher temperatures.As a result, bit errors due to sticking to stampers and replicas cause serious problems, and burning due to deterioration of the resin. Therefore, there has been a demand for a material that can be molded at a lower temperature because the rate of occurrence of errors in the final product increases and there are various problems. On the other hand, regarding the mold temperature, since the interval and depth of the grooves are narrower and deeper,
Although the temperature is higher, the higher the temperature is, the more the problem of the warpage of the molded substrate becomes apparent, and a lower mold temperature is required similarly to the molding temperature.

[0003]

SUMMARY OF THE INVENTION In view of the above-mentioned background, polycarbonate resins are not impaired at the lower molding temperature and mold temperature without impairing the important characteristics (birefringence, transferability, warpage) of the disk substrate. The demand for moldable materials has increased. In this regard, it has been well known that the flowability of the polycarbonate resin itself is improved by increasing the alkyl chain length of the alkyl phenol, which has been conventionally used as a terminal blocking agent for the polycarbonate resin. For example, British Patent No. 965,457 describes the use of long-chain monofunctional alcohols as endcapping agents to reduce melt viscosity, and U.S. Patent No. 3,240,756. Describes the use of alkylphenols as terminators. JP-A-51-34992 discloses that a polycarbonate resin is produced by using a phenol, an acid chloride, an acid or an alcohol having an alkyl group having 8 to 20 carbon atoms as a terminal blocking agent to improve fluidity. Examples are given. In recent years, JP-A-60-203632 discloses an example in which a polycarbonate resin having a long-chain alkyl group at a terminal is used as an optical molded product. These all point out that the flowability can be improved by the presence of the long-chain alkyl group at the molecular terminal of the polycarbonate.

However, the polycarbonate obtained using such a long-chain alkylphenol has an extremely yellow hue in the resulting product, as compared with a conventionally used polycarbonate using t-butylphenol.
It was found that the optical recording medium was colored to such an extent that it could not be used, and was inferior in the long-term reliability (no bit error when kept under high temperature and high humidity conditions) required for the disk.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems of the prior art, and have reached the present invention. That is, the gist of the present invention is to provide a polycarbonate obtained by reacting a reaction raw material containing a diphenol, a carbonate raw material and a terminal blocking agent comprising a p-substituted phenol represented by the following general formula (I) (hereinafter referred to as a para-form). A polycarbonate, wherein the content of the o-substituted phenol (hereinafter referred to as ortho-form) which is an impurity in the terminal blocking agent used satisfies the relationship of the following formula (1). Resin, exists.

[0006]

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(In the general formula (I), R is an organic group having 9 to 16 carbon atoms.)

[0008]

(Equation 2)

Another aspect of the present invention is to provide a diphenol,
Carbonate raw materials and p- represented by the following general formula (I)
A polycarbonate resin obtained by reacting a reaction raw material containing a terminal blocking agent composed of a substituted phenol, wherein the YI value of a molded product (3.2 mm thickness) obtained by molding the polycarbonate resin in a cycle of 360 ° C. × 180 seconds is 2. A polycarbonate resin having a difference of 5 or less and a YI value of the first shot and the 10th shot (hereinafter referred to as ΔYI) of 0.8 or less.

[0010]

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(In the general formula (I), R is an organic group having 9 to 16 carbon atoms.) Still another aspect of the present invention is to provide a substrate for an optical information recording medium using the above polycarbonate resin, And an optical information recording medium using the same.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The polycarbonate resin of the present invention is produced by reacting a reaction material containing a diphenol, a carbonate material and a specific terminal blocking agent. The diphenol used in the present invention is a compound having two phenolic hydroxyl groups, and is preferably one represented by the general formula: HO-Z-OH.
Here, Z is an organic group containing one or more aromatic nuclei, and a hydrogen atom bonded to a carbon atom of the aromatic nucleus is
It can be substituted with a chlorine atom, a bromine atom, an aliphatic group or an alicyclic group. A plurality of aromatic nuclei may each have a different substituent. Further, a plurality of aromatic nuclei may be bonded by a cross-linking group. The bridging group includes an aliphatic group, an alicyclic group, a heteroatom, or a combination thereof.

Specifically, hydroquinone, resorcin,
Dihydroxydiphenyl, bis (hydroxyphenyl)
Alkanes, bis (hydroxyphenyl) cycloalkane, bis (hydroxyphenyl) sulfide, bis (hydroxyphenyl) ether, bis (hydroxyphenyl) ketone, bis (hydroxyphenyl) sulfone, bis (hydroxyphenyl) sulfoxide, bis (hydroxyphenyl) Dialkylbenzenes and derivatives thereof having an alkyl or halogen substituent on the aromatic nucleus are mentioned. It is also possible to use two or more of these diphenols in combination.

These and other suitable diphenols are described, for example, in US Pat. No. 4,982,014,
No. 3,028,365 and No. 2,999,835
No. 3,148,172, No. 3,275,60
No. 1, No. 2,991,273, No. 3,271,3
No. 67, No. 3,062,781, No. 2,970,
Nos. 131 and 2,999,846,
German Patent Publication Nos. 1,570,703 and 2,06
No. 3,050, 2,063,052, and 2,211,956, and French Patent 1,561,518.

Preferred diphenols include 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4- Hydroxyphenyl) cyclohexane and 1,1-bis (4-hydroxyphenyl)-
Bisphenols containing two phenol residues such as 3,3,5-trimethylcyclohexane in the skeleton are included.

The carbonate raw material used in the present invention is a carbonate bond in the polycarbonate main chain by a polymer formation reaction such as a condensation reaction or an exchange reaction.

[0017]

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And phosgene, diphenyl carbonate and the like. In the present invention, the method for producing the polycarbonate resin is not particularly limited, but an interfacial polycondensation method using phosgene as a raw material is generally used. A method of first reacting phosgene with an alkylphenol to produce a dialkylphenyl carbonate and reacting the diphenol with the diphenol under melt condensation conditions can also be mentioned, but melt conditions (up to 300 ° C) and high vacuum conditions (≦
It is a method of extending the molecular weight by transesterification while distilling the alkylphenol at 50 mmHg). Since the longer the alkyl chain length of the alkylphenol becomes, the more difficult the distillation becomes, it is not necessarily an industrially suitable method. Absent.

The terminal blocking agent used in the present invention is a substituted phenol having an organic group having 9 to 16 carbon atoms at the para position and is represented by the following general formula (I).

[0020]

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(In the formula (I), R is an organic group having 9 to 16 carbon atoms.) Specific examples of the organic group R include an alkyl group, an alkenyl group, an alkoxyl group and an alkoxyalkyl group. And some of these substituents may be substituted with another atom (O, S, N, etc.). The wide range of carbon numbers is largely attributable to the method for producing long-chain alkylphenols. In general, the reaction of adding propylene or isobutene trimer, tetramer, etc. to phenol with an acid catalyst is often used.For example, among propylene tetramers, tetramers are mainly composed of ± tetramers. In general, a substance having a distribution is used, and although the main component can be specified, the number of carbon atoms cannot be limited. Therefore, in this specification, the carbon number of the substituent of the substituted phenol indicates the carbon number of the highest existing ratio in the mixture.

Among the above, the following general formula (II):

[0023]

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(In the general formula (II), R 'is a group having 9 to 16 carbon atoms.)
Is an alkyl group). Specifically, alkylphenols such as nonylphenol, dodecylphenol, and 3-pentadecylphenol are preferred. If the carbon number of the alkyl group is too small, the content of impurities is small and the YI value of the obtained product is good, but there is no fluidity improving effect at the time of melt molding, and the transferability improving effect at the time of disk molding is also recognized. Absent. On the other hand, if the carbon number is too large, the Tg of the obtained product is extremely reduced, and although it depends on the molding conditions, it is undesirably expressed as warpage of the disc as a result. Therefore, the number of carbon atoms serving as the main component is 9 to 16, preferably 9 to 15, more preferably 11 to 15, and particularly preferably 12.

The present inventors have found that the terminal blocking agent comprising the above-mentioned p-substituted phenol (hereinafter referred to as para-form) contains:
O-Substituted phenols having different substitution positions of organic groups as impurities derived from the production process (hereinafter referred to as ortho-form)
It has been found that by regulating the content of the ortho-form, the hue of the polycarbonate resin product can be effectively improved and the long-term reliability, which is required as a characteristic required for a disk application, can be improved. That is, the hue of the polycarbonate resin is effectively improved by setting the ratio of the ortho form in the substituted phenol composed of the para form and the ortho form to a specific value or less.

Specifically, as shown in the following equation (1),
It is preferable that the ortho-form content satisfies the relationship of the following formula (1) with respect to the sum of the para-form content and the ortho-form content. :

[0027]

(Equation 3)

The ortho-form content represented by the fractional expression on the left side of the above formula (1) is more preferably less than 9500 ppm, and further preferably less than 9000 ppm. If the content of the ortho body is too large, the hue of the obtained polycarbonate resin product is extremely deteriorated. On the other hand, if the ortho-form content is controlled to be too small, from the viewpoint of the production side of a substituted phenol, for example, an alkylphenol, the yield becomes poor, which is not a preferable condition. The ortho-form content represented by the fractional expression part is 10 ppm or more, especially 100 ppm
Excessive regulation can be avoided by setting it to at least ppm, and more preferably at least 1000 ppm.

When considering from the viewpoint of the production of a substituted phenol, for example, an alkyl phenol, a means for reducing the ortho-form content by means of distillation separation is generally considered. On the other hand, it is also possible to suppress the formation of the ortho form from the reaction stage. For example, the reaction time in the acid-catalyzed alkylation step may be increased, or the time for the isomerization reaction (from the ortho form to the para form) may be increased. By taking it, the content of the ortho-form can be reduced.

The amount of the terminal blocking agent used in the production of the polycarbonate resin varies depending on the molecular weight of the target polycarbonate resin. For example, in the case of the interfacial polycondensation method, it is usually based on the amount of diphenol in the aqueous phase. , 1-9
Mol%, preferably 4 to 8 mol%, more preferably 5%
About 7 mol% is the amount used for disk applications.

On the other hand, there is no particular limitation on the position where the terminal blocking agent is added. For example, when the terminal blocking agent is added in the presence of phosgene, a large amount of condensates (such as diphenyl carbonate) of the terminal blocking agent are formed. However, as a result, a large amount of volatile matter at higher temperatures is accumulated, which is not preferable. On the other hand, when the addition of the terminal blocking agent is extremely delayed, it is difficult to control the molecular weight, which is not preferable. After all, the addition of the end-capping agent starts immediately after the consumption of phosgene ends.
It can be said that a period before the start of molecular weight extension is preferable.

In the production of the above polycarbonate resin, an optional branching agent can be added. The branching agent used can be selected from various compounds having three or more functional groups. Examples of suitable branching agents include 3
2,4-bis (4-hydroxyphenylisopropyl) phenol, 2,6-bis (2'-hydroxy-5'-methylbenzyl) -4-methyl which is a compound having one or more phenolic hydroxyl groups Phenol, 2- (4-hydroxyphenyl) -2- (2,4
-Dihydroxyphenyl) propane and 1,4-bis (4,4'-dihydroxytriphenylmethyl) benzene. Also, compounds having three functional groups, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride, bis (4-hydroxyphenyl) -2-oxo-2,3-dihydroxyindole and 3,3- Bis (4-hydroxy-3-methylphenyl) -2-oxo-2,3-dihydroindole is also included. Among them,
Those having three or more phenolic hydroxyl groups are preferred. The amount of the branching agent used varies depending on the desired degree of branching, but is usually used in an amount of 0.05 to 2 mol% based on the amount of diphenol in the aqueous phase.

In the production of the above polycarbonate resin, the organic phase dissolving the produced polymer dissolves phosgene and reaction products such as carbonate oligomers and polycarbonate at the reaction temperature and reaction pressure, but does not dissolve water (water and water). It is necessary to include any inert organic solvents (in the sense that no solution is made). Representative inert organic solvents include aliphatic hydrocarbons such as hexane and n-heptane, methylene chloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloropropane and 1,2-dichloroethylene. Chlorinated aliphatic hydrocarbons, aromatic hydrocarbons such as benzene, toluene and xylene, chlorinated aromatic hydrocarbons such as chlorobenzene, o-dichlorobenzene and chlorotoluene, and substituted aromatic hydrocarbons such as nitrobenzene and acetophenone Contains hydrogen.
Among them, chlorinated hydrocarbons such as methylene chloride or chlorobenzene are preferably used.

These inert organic solvents can be used alone or as a mixture with other solvents.
In the production of the polycarbonate resin, prior to contact with phosgene, a condensation catalyst is supplied at the time of contact between the aqueous phase and the organic phase, and the formation of an emulsion can be performed in the presence of the condensation catalyst; Also preferred. Of course, if you want
The supply of the condensation catalyst may be performed at the time of contact with phosgene. The condensation catalyst can be arbitrarily selected from many condensation catalysts used in the interfacial polycondensation method. Among them, trialkylamine, N-ethylpyrrolidone, N-ethylpiperidine, N-ethylmorpholine,
N-isopropylpiperidine and N-isopropylmorpholine are particularly preferred, especially triethylamine and N-isopropylmorpholine.
-Ethyl piperidine is suitable.

In the above method, there is no particular limitation on the method of phosgenation. For example, in order to improve the purity of the raw material used, free chlorine, which is a low-boiling impurity in the phosgene used, is removed and purified. And emulsifying the other raw materials, methylene chloride (organic phase) and alkali metal salt of diphenol (aqueous phase) in advance, and bringing the emulsion having an increased interfacial area into contact with phosgene. A preferable method for thermal stability can be taken, such as advancing the reaction with the dominant growing species of the mate.

In this case, it is necessary that the aqueous phase to be emulsified contains at least three components of water, diphenol and alkali metal hydroxide. In the aqueous phase, the diphenol reacts with an alkali metal hydroxide, such as sodium hydroxide or potassium hydroxide, to produce a water-soluble alkali metal salt. Of course, it is preferable to mix the above three components to prepare a uniform aqueous solution and prepare an aqueous phase before contacting the organic phase with the organic phase. All in contact with the organic phase,
Mixing is also possible. The molar ratio of diphenol to alkali in the aqueous phase is preferably from 1: 1.8 to 1: 3.5, more preferably from 1: 2.0 to 1: 3.2. When preparing such an aqueous solution, the temperature is preferably at least 20 ° C., preferably 30 to 40 ° C. However, if the temperature is too high, oxidation of diphenol occurs. Or adding a small amount of a reducing agent such as hydrosulfite.

The reaction temperature for obtaining the oligomer is 80
C. or lower, preferably 70 ° C. or lower, more preferably 10 ° C. or lower.
It is preferably in the range of ~ 65 ° C. If it is too high, side reactions cannot be suppressed, and the phosgene specific unit deteriorates. On the other hand, if the temperature is too low, it is preferable in terms of reaction control, but the refrigeration load increases, and the cost increases accordingly, which is not preferable.

The concentration of the oligomer in the organic phase at the stage of obtaining the oligomer may be within a range in which the obtained oligomer is soluble, and specifically, about 10 to 40% by weight. Further, the proportion of the organic phase is preferably 0.2 to 1.0 by volume with respect to the aqueous solution of the alkali metal hydroxide of diphenol, that is, the aqueous phase. The average molecular weight (Mv) of the oligomer obtained under such condensation conditions is usually 5
About 00 to 10,000, preferably 1600 to 4,
Although it is 500, it is not particularly limited.

The oligomer thus obtained is converted into a high-molecular polycarbonate under the conditions of polycondensation according to a conventional method. In a preferred embodiment, the organic phase in which the oligomer is dissolved is separated from the aqueous phase and, if necessary,
The concentration of the oligomer is adjusted by adding the above-mentioned inert organic solvent. That is, the amount of the solvent is adjusted so that the concentration of the polycarbonate in the organic phase obtained by the polycondensation is usually 5 to 30% by weight. Thereafter, a new aqueous phase containing water and an alkali metal hydroxide is added, and in order to further adjust the polycondensation conditions, preferably the above-mentioned condensation catalyst is added, and the desired polycondensation is performed according to the interfacial polycondensation method. Complete the reaction. The ratio of the organic phase to the aqueous phase during the polycondensation reaction is preferably about 1: 0.2 to 1 in terms of volume ratio: organic phase: aqueous phase = 1: 0.2-1.

After completion of the polycondensation reaction, until the remaining chloroformate group becomes, for example, 0.1 μmol / g or less,
Washing treatment is performed with an alkali such as NaOH. After that,
The organic phase is washed until the electrolyte is exhausted, and finally the appropriate organic solvent is removed from the organic phase to separate the polycarbonate. The average molecular weight (Mv) of the polycarbonate thus obtained is usually 10,000 to 10
Although it is about 000, the Mv preferably used for disk applications is usually about 13,000 to 20,000, more preferably about 14,000 to 18,000.

As a molding temperature for forming an optical molded product, a high temperature must be selected depending on a bit interval and a depth of a stamper to be used. In the case where a special substituted phenol, especially an alkyl phenol must be selected, the storage capacity has also been considerably increased, and the molding temperature to be selected is usually 340 to 400 ° C., preferably 350 to 39 ° C.
The temperature is 0 ° C, more preferably about 360 to 385 ° C.

In this specification, the average molecular weight (M
v) is the concentration of oligomer or polycarbonate (C) (0.6 g / dl methylene chloride solution)
From the specific viscosity (ηsp) measured at a temperature of 20 ° C., the following two formulas are obtained:

[0043]

Ηsp / C = [η] (1 + 0.28ηsp) [η] = 1.23 × 10 ⁻⁵ × Mv ^0.83

During the separation of the polycarbonate resin obtained by the above method from the reactor or before or during the processing thereof, various additives such as a stabilizer, a mold release agent, a flame retardant, a charge retarder, Inhibitors, fillers,
An effective amount of fiber, impact strength modifier, etc. can be added. These polycarbonate resins are various molded products by injection molding, extrusion molding, etc., for example, films, yarns,
It can be processed into plates, etc., in various technical fields, for example in the electrical component or building industry, and also for lighting equipment and optical equipment materials, especially lamp housings, optical lenses, optical discs and audio discs. used. Particularly, it is preferably used in the optical field where high-temperature molding is required.

In an optical information recording medium, a polycarbonate resin is generally used as a substrate, and a read-only optical disk (CD, CD-ROM, DVD-ROM) is used.
Etc.), recording / reproducing optical disk (write-once type: CD-
R, DVD-R, etc.), recordable / reproducible / erasable / rewritable optical disk (rewritable type: MO, CD-RW, DV)
D-RAM, etc.) are known.

[0046]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto unless they depart from the gist. The symbols or abbreviations used in the examples have the following meanings.

[0047]

Table 1 Symbols or abbreviations Meaning BPA Bisphenol A BPA-Na Bisphenol A sodium salt GPC gel permeation chromatography Examples 1-3 Bisphenol A 16.31 kg / h, NaOH
5.93 kg / h and 101.1 kg / h of water are brought to 35 ° C. in the presence of 0.018 kg / h of hydrosulphite.
After dissolving in the above, an aqueous phase cooled to 25 ° C. and an organic phase of methylene chloride 68.0 kg / hour cooled to 5 ° C. are supplied to stainless steel pipes having an inner diameter of 6 mm and an outer diameter of 8 mm, respectively.
Mix in the same pipe, and further add a homomixer (product name: TK homomic line flow LF-5 manufactured by Tokushu Kika Co., Ltd.).
(Type 00) to emulsify to prepare an emulsion.

The thus-obtained emulsion of the BPA-Na aqueous solution (aqueous phase) and methylene chloride (organic phase) was taken out from a homomixer through a pipe having an inner diameter of 6 mm and an outer diameter of 8 mm. In a pipe reactor made of Teflon (registered trademark) having an inner diameter of 6 mm and a length of 34 m to be connected, it was brought into contact with 7.5 kg / hour of liquefied phosgene supplied from a pipe cooled to 0 ° C. separately introduced here. This liquefied phosgene is placed in a cylindrical container having a diameter of 55 mm and a height of 500 mm in an activated carbon (manufactured by Taihei Chemical Co., Ltd., trade name: Cocol S, physical properties described below)
And subjected to a liquid-passing treatment at -5 ° C., 7.2 kg / hour and SV = 3.

[0049]

[Table 2] Activated carbon used: Particle size: 30-60 mesh True density: 2.1 g / cc Porosity: 40% Specific surface area: 1200 m ² / g Pore volume: 0.86 cc / g The above raw materials were phosgene and the inside of a pipe reactor. , 1.7m
The phosgenation and oligomerization reactions were carried out while flowing at a linear speed of / sec for 20 seconds. At this time, the reaction temperature was adjusted so as to be 60 ° C., and each was externally cooled to 35 ° C. before entering the next oligomerization tank.

The oligomerized emulsion obtained from the pipe reactor in this manner was further introduced into a reaction vessel having an internal volume of 50 liters equipped with a stirrer, and then subjected to 30 minutes under an N ₂ atmosphere.
After the unreacted BPA-Na present in the aqueous phase was completely consumed by stirring and oligomerization at 0 ° C., the aqueous phase and the organic phase were allowed to stand and separated to obtain a methylene chloride solution of the oligomer. . In the oligomerization, the catalyst triethylamine 0.1.
Alkyl phenols of the type and amount (mol% (relative to diphenol)) shown in Table 1 were introduced into the oligomerization tank at 005 kg / hr and as a terminal blocking agent. Table 1 also shows the ortho-form content (ppm) with respect to the total of.

The production of dodecylphenol used in Examples 1 to 3 was carried out as follows. The raw material dodecene, which had been heated to 50 ° C., was mixed with phenol whose temperature had been similarly raised (4 times mol: dodecene), and passed through an acidic ion-exchange resin tower to carry out an alkylation reaction. Since heat was generated at this time, the liquid was passed while removing the heat. The reaction solution thus obtained was similarly supplied to a reaction tower filled with an acidic ion exchange resin, and the ortho isomer was isomerized to the para isomer.

The dodecylphenol thus obtained was subjected to an initial phenol separation distillation column to remove phenol, and another column was used to cut off heavy ends such as dialkyl compounds as impurities to obtain a product. All alkylphenols used in the examples were those in which the normal alkylation reaction time and the isomerization reaction time were doubled or more, and in some cases, the ortho-isomer generated by reducing the distillation conditions was further reduced. .

Of the above methylene chloride solution of the oligomer, 23 kg was charged into a 70-liter reaction tank equipped with Faudler blades, and 10 k of methylene chloride for dilution was added thereto.
g, and a 25 wt% aqueous NaOH solution 2.2 k
g, 6 kg of water and 2.2 g of triethylamine.
_The mixture was stirred at 30 ° C. under _two atmospheres, and a polycondensation reaction was performed for 60 minutes to obtain a reaction solution containing polycarbonate.

To this reaction solution, 30 kg of methylene chloride and 7 kg of water were added, and after stirring for 20 minutes, the stirring was stopped.
The aqueous and organic phases were separated. 20 kg of 0.1 N hydrochloric acid was added to the separated organic phase, and the mixture was stirred for 15 minutes. After extracting triethylamine and a small amount of remaining alkaline component, the stirring was stopped, and the aqueous phase and the organic phase were separated. Further, 20 kg of pure water was added to the separated organic phase, and the mixture was stirred for 15 minutes.
The stirring was stopped and the aqueous and organic phases were separated. Repeat this operation until chlorine ions in the extraction wastewater are no longer detected (three times)
Repeated.

The obtained purified polycarbonate solution was
Powdered and dried to obtain granular powder (flakes)
Was. The flakes are fed into a 30 mm twin screw extruder (Ikegai Iron Works)
N) at a resin temperature of 290 ° C _TwoAfter mixing in an atmosphere, Pele
(15 kg / h). At this time, impurities
Contamination point (derived from human hands, sweat and cooling water)
(Impurities).

The average molecular weight and the molecular weight distribution of the flakes obtained in each Example and the color tone of the pellets were measured. Table 1 shows the results. In addition, "-" in a table represents unmeasured. The physical properties of the polycarbonates in the table were evaluated as follows. 1) Molecular weight distribution (Mw / Mn): 4 kinds of high-speed GPs using a GPC apparatus (manufactured by Tosoh Corporation, product name: HLC-8020) and using tetrahydrofuran (THF) as an eluent.
Filler for C (Tosoh Corporation, product name TSK 500
0HLX, 4000HLX, 3000HLX and 200
0HLX), the weight average molecular weight (Mw) and the number average molecular weight (Mn) were calculated in terms of polystyrene from the chart obtained by detecting the difference in refractive index, and calculating Mw / Mn. did.

2) Color tone (YI value): <Molding of sample plate> The pellet obtained as described above was injected into an injection molding machine (Nihon Steel Works, product name JSW).
After plasticizing at 360 ° C. using J75EII), the sample was retained in a cylinder for 180 seconds to form a 3.2 mm thick, 60 mm square sample plate. <Measurement of Color Tone> The color tone (YI value) of the sample plate of the first shot and the tenth shot in the above molding was measured using a color difference meter (product name: CM-3700D, manufactured by Minolta Co., Ltd.). Of the measured values, a small YI value of the first shot indicates that the color tone during steady molding is good, and a small difference (ΔYI) between the YI values of the first shot and the tenth shot indicates a high temperature. It shows that the thermal stability is good.

3) Long-term reliability test Using an injection molding machine (product name: CD mini) manufactured by Sumitomo Heavy Industries, under the following conditions, C having a diameter of 80 mm and a thickness of 1.26 mm was used.
D substrate was formed.

[0059]

[Table 3] Cylinder temperature: 300 ° C Die temperature: 80 ° C / 70 ° C Cycle time: 10 seconds 100 shots are continuously and stably formed, and 10 stable products are sampled, and 85 ° C, 85% It was kept under RH environment for 2 days.

After the holding, the whole substrate was observed under a deflection microscope, and it was observed in detail whether or not there was a hydrolytic white point. 4) Melt viscosity: As a method of comparing the fluidity during melting,
L (orifice length) / D using Capillograph (Toyo Seiki Seisakusho, product name: Capillograph 1B)
(Orifice diameter) / B (barrel diameter) = 40/1 / 9.5
The melt viscosity was measured under the conditions of 5 (mm), 250 ° C., and shear rate = 100 sec ⁻¹ .

5) Total light transmittance (ASTM D100)
3): As a measure of the transparency required for the disk substrate, the total light transmittance of the 3.2 mm thick sample plate was measured. If this value is low, it indicates that there is a problem in the transparency inherent in polycarbonate, and it can be determined that the polycarbonate cannot be used as an optical material.

6) Comparison of transferability to a stamper and evaluation of substrate characteristics during disk molding: using an SD30 molding machine manufactured by Sumitomo Heavy Industries, having a diameter of 120 mmφ and a recording area thickness of 0.6.
mm substrate was formed under the following conditions. The stamper is 4.
7GB DVD-R compatible was used. This stamper has a track pitch of 0.74 μm and a groove depth of 170
nm.

[0063]

[Table 4] Cylinder temperature: 385 ° C Mold temperature: 130 ° C / 124 ° C Filling time: 0.09 seconds Cooling time: 9.0 seconds Compressive force (ton): 20-12-8-5 Molding under these conditions After that, the depth of the groove on the outermost periphery of the recording area transferred onto the polycarbonate substrate was measured, and the quality of transferability was compared.

<Birefringence> The maximum value and the minimum value of the in-plane birefringence were shown using an automatic birefringence measuring device ADR-130N manufactured by Oak Manufacturing Co., Ltd. <Mechanical properties> The mechanical properties of the substrate are based on the DVD-R standard (DV
D Specifications for Recorder
double Disc / Part. 1 Physica
lSpecifications Ver. 1.0 J
uly 1997).

As a result, those that were cleared with a sufficient margin were represented by ○, and those that were marginally but cleared were represented by Δ. Comparative Examples 1 and 2 The same operation as in Example 1 was performed except that the alkylphenol described in Table 2 was used as a terminal blocking agent. All of the alkylphenols used have been treated with conventional reaction times and isomerization times, and most commercially available products have this composition. Table 2 shows the results. Comparative Example 3 The cylinder temperature during molding was set to 395 ° C., and the mold temperature was set to 1
The same operation as in Comparative Example 1 was performed except that the temperature was changed to 32 ° C./126° C. Table 2 shows the results.

[0066]

[Table 5]

[0067]

[Table 6] In the above table, it can be seen that, in Comparative Example 1, since the carbon number of the alkyl group substituted by phenol is small, the fluidity at the time of melting is poor, and the transferability observed in the substrate characteristics is also poor.

On the other hand, in the case of the alkylphenol of Comparative Example 2, since the content of the ortho-form as an impurity is high, the fluidity and transferability are good, but the long-term reliability is poor and the hue is poor. Can not stand the use of. In Comparative Example 3, an alkylphenol having a small number of carbon atoms was used, and the molding conditions were strict. Therefore, there was a problem in mechanical properties of the substrate.

Regarding the characteristics of the substrate, regarding the transfer, 17
A value close to 0 nm is good. For birefringence, Min to Ma
The smaller the distance between x, the better.

[0070]

The polycarbonate resin of the present invention usually has an average molecular weight of 10,000 to 100,000, and the molded product has not only excellent physical properties inherent to the polycarbonate resin but also a fluidity during molding. Significantly improved,
There is an advantage that a predetermined molded product can be obtained at a lower molding temperature, and a molded product with little coloring and high reliability can be obtained. Therefore, there is an advantage that its application range can be greatly expanded as compared with a conventional product. Even at a lower molding temperature, it has an advantage of being excellent in transferability to a mold and a stamper, and it is possible to obtain a product with less deterioration and a high yield as a product.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryuji Uchimura 1-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu City, Fukuoka Prefecture Inside the Kurosaki Works of Mitsubishi Chemical Corporation (72) Inventor Toshimitsu Inoue 1st Kurosaki Castle Stone, Yawata Nishi-ku, Kitakyushu City, Fukuoka Prefecture No. 1 Kurosaki Office of Mitsubishi Chemical Corporation

Claims (7)

[Claims] 1. A diphenol, a carbonate raw material and a p-substituted phenol represented by the following general formula (I)
Content of an o-substituted phenol (hereinafter referred to as ortho-form) which is a polycarbonate resin obtained by reacting a reaction raw material containing a terminal blocking agent comprising a para-blocking agent. Satisfies the relationship of the following formula (1). Embedded image (In the general formula (I), R is an organic group having 9 to 16 carbon atoms.) 2. The polycarbonate resin according to claim 1, wherein R in the formula (I) is an organic group having 11 to 15 carbon atoms. 3. Polycarbonate resin at 300 ° C. × 10
CD molded product (1.26 mm thick) molded by second cycle 1
After keeping 0 sheets under 85 ° C. and 85% RH environment for 2 days,
3. The polycarbonate resin according to claim 1, wherein the number of hydrolyzed white spots generated on the substrate surface is 5 or less. 4. A polycarbonate resin obtained by reacting a reaction material containing a diphenol, a carbonate material and a terminal blocking agent comprising a p-substituted phenol represented by the following general formula (I), wherein the polycarbonate resin is 3
Molded product (3.2 m
m thickness) is 2.5 or less, and the first shot is 1
A polycarbonate resin having a difference in YI value of the 0th shot (hereinafter, referred to as ΔYI) of 0.8 or less. Embedded image (In the general formula (I), R is an organic group having 9 to 16 carbon atoms.) 5. The polycarbonate resin according to claim 4, wherein R in the formula (I) is an organic group having 11 to 15 carbon atoms. 6. A substrate for an optical information recording medium comprising the polycarbonate resin according to claim 1. 7. An optical information recording medium comprising a substrate made of the polycarbonate resin according to claim 1 and an optical information recording layer provided on the substrate.