JPH01178518A - Resin for optical material - Google Patents

Abstract

PURPOSE:To obtain the title resin having a low photoelastic constant and excellent optical properties, heat resistance, surface hardness and water absorptivity, by copolymerizing a specified compound with a bisphenol through carbonate bonds. CONSTITUTION:99-1mol.% 1,1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane is copolymerized with 1-99mol% bisphenol of formula I [wherein X is a direct bond, a 1-8C alkylene, a 2-9C alkylidene, -O-, -S-, -SO-, -SO2-, -CO- or a group of any one of formulas II-VII (wherein l is 2-10), and R1-4 are each H, a 1-6C alkyl, an aryl or a halogen] through carbonate bonds to obtain the title resin comprising 1-99mol.% repeating units of formula VIII and 99-1mol.% repeating units of formula IX and having a viscosity-average MW of 10,000-100,000.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a sealant for optical materials. Furthermore, the present invention relates to a polycarbonate copolymer used in an optical information recording disk in which a signal is recorded by a laser beam, or a recorded signal is read by reflection or transmission of the laser beam.

(Prior art) DRAW, in which a spot beam of a laser beam is applied to a disk to record signals on the disk in the form of minute pits, or the signals recorded by such pits are read out by detecting the amount of reflected or transmitted light of the laser beam;
Erasable-DRAW type optical information recording/reproducing method can significantly increase recording density, especially Er
As the asable-DRAW type allows recording to be erased and written, and the images and sound quality reproduced from them have excellent characteristics, it is suitable for recording and reproducing images and sounds, recording and reproducing large amounts of information, etc. It is expected that this technology will be widely put into practical use. The disks used in this recording/reproducing system are not only required to be transparent so that laser beams can pass through the disk body, but also to have optical homogeneity to reduce reading errors. Birefringence occurs when the laser beam passes through the disk body, mainly due to thermal stress generated during the cooling and flow process of the resin during disk body molding, residual stress due to bimolecular orientation, volume change near the glass transition point, etc. . This large optical non-uniformity caused by birefringence is a fatal defect for optical discs.

(Problems to be Solved by the Invention) Birefringence, which is mainly caused by thermal stress, molecular orientation, and residual stress generated during the cooling and flow process of the resin during disk molding, can be solved by selecting the molding conditions. Although the birefringence of the resulting disk can be considerably reduced,
It largely depends on the inherent birefringence of the molding resin itself, that is, the photoelastic constant.

(Means for solving the problem) Birefringence is expressed as the product of photoelastic constant and residual stress using the following formula (1).
It can be expressed as

nl-n2=C(a1G2) (1)nl-
n2: Birefringence σ1-02: Residual stress C: Photoelastic constant It is clear that if the photoelastic constant of formula (1) is made smaller, the birefringence of the obtained disk becomes smaller even if the molding conditions are the same.

Therefore, the inventors discovered 1,1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane represented by the formula (IZ formula (
II') E In the formula, X is a single bond, and alkylene having 1 to 8 carbon atoms.

R1 to R4 each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, or a halogen atom. The inventors have discovered the fact that by copolymerizing bisphenols represented by the following through carbonate bonds, a resin with a small photoelastic constant can be obtained without impairing the mechanical properties of aromatic polycarbonate, leading to the present invention.

That is, the present invention provides 1,1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane (9).
The present invention relates to an aromatic polycarbonate copolymer obtained by carbonate bonding of 9 to 1 mol % and 1 to 99 mol % of the general formula (II').

Thus, the present invention is an aromatic polycarbonate having the following repeating unit (I) and repeating unit (t (II)), wherein X is a single bond and an alkylene having 1 to 8 carbon atoms.

R1 to R4 each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, or a halogen atom. ] The mole fraction of repeating unit (I) is 1 to 99 mol%, and the mole fraction of repeating unit (II) is 99 to 1 mol%.
The present invention relates to an optical disc made of aromatic polycarbonate.

The photoelastic constant of the aromatic polycarbonate obtained when the structural unit of formula (I) is less than 1 mol % is not much different from that of the homopolycarbonate of formula (II). If the content of the structural unit of formula (I) exceeds 99 mol %, the fluidity and glass transition point of the resulting aromatic polycarbonate will be significantly lower than that of the homopolycarbonate of formula (II).

The viscosity average molecular weight of the copolymer of the present invention is 10,000 to 1
00,000 is preferred, 13,000 to 50,000
is even more preferable. If it is less than 10,000, the molded product becomes brittle, and if it exceeds 100,000, fluidity decreases and moldability is poor, and both are unsuitable as resins for optical materials.

Moreover, the polycarbonate copolymer of the present invention has 1,1-
A copolymer of bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and a third component in addition to the general formula (II') may also be used. Any third component may be used as long as it forms a carbonate bond.

The polymerization ratio may be within a range that does not impair physical properties.

The method for producing the polycarbonate copolymer of the present invention includes:
There are two methods:

■ Transesterification method 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and j of the general formula (II')
Then, a slightly less than stoichiometrically equivalent amount of diphenyl carbonate is heated with an inert gas at a temperature of about 160 to 180° C. and under normal pressure in the presence of a conventional carbonation catalyst. The reaction is carried out for about 30 minutes under submerged conditions, and the precondensation is finally completed at 10 Torr and 220°C at a temperature of about 180 to 220°C while gradually reducing the pressure over 2 hours. Then, at 10 Torr and 270°C for 30 minutes,
React for 20 minutes at 5 Torr and 270°C, then 0.
5 Torr or less, preferably 0.3 Torr-0, IT
The condensation is proceeded after 1.5 to 2.0 hours at 270° C. under vacuum of orr.

In addition, carbonation catalysts for carbonate bonding include alkali metals such as lithium-based catalysts, potassium-based catalysts, sodium-based catalysts, calcium-based catalysts, and tin-based catalysts;
Alkaline earth metal catalysts are suitable, such as lithium hydroxide, lithium carbonate, potassium borohydride, potassium hydrogen phosphate, sodium hydroxide, sodium borohydride, calcium hydride, dibutyltin oxide.

Examples include stannous oxide. Among these, it is preferable to use potash-cum-based solvents or single-media solvents.

・Attach a stirrer, a thermometer, a gas inlet pipe, and an exhaust pipe to a three-bottle flask for the phosgene method. ') is dissolved in a solvent such as pyridine, dichloromethane, etc., and phosgene gas is introduced while stirring, but since phosgene is extremely poisonous, it is operated in a strong trough). . Additionally, a unit is attached to the exhaust terminal that decomposes and detoxifies excess phosgene with a 10% aqueous sodium hydroxide solution. Phosgene is introduced from the cylinder into the flask through an empty washing bottle, a washing bottle containing paraffin (count the foam), and an empty washing bottle.

The gas introduction tube should be inserted above the stirrer, and the tip should be widened into a funnel shape to prevent it from getting clogged by precipitated pyridine salt.

As gas is introduced, pyridine hydrochloride precipitates and the contents become cloudy. Cool with water so that the reaction temperature is 30°C or less. It becomes viscous as the condensation progresses. Phosgene
Pass phosgene through until the yellow color of the hydrogen chloride complex no longer disappears. After the reaction is completed, methanol is added to precipitate the polymer, which is then filtered and dried. Since the polycarbonate produced is soluble in methylene chloride, pyridine, chloroform, tetrahydrofuran, etc., it is purified by reprecipitation from these solutions with methanol.

The polycarbonate copolymer obtained in this way is
It is useful for DRAW and E-DRAW type optical information recording discs in which signals are recorded by laser beams or recorded signals are read by reflection or transmission of laser beams.

(Examples) The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples.

Incidentally, part 9% indicates a weight basis.

Example 1 222 parts (50 mo 1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 13 parts of 2,2-bis(4-hydroxyphenyl)propane
7 parts (50mo1%) and diphenyl carbonate 264
Place 31 parts in a three-way flask, degas and nitrogen purge for 5
After repeating this process several times, the mixture was melted in a silicon bath at 160° C. while introducing nitrogen. Once melted, add a solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (2X based on the total amount of bisphenol charged).
10-3 mo1% amount) and heated at 160°C under N2
The mixture was stirred and incubated for 0 minutes. Next, the pressure was reduced to 100 Torr at the same temperature, and after stirring for 30 minutes, the pressure was further reduced to 50 Torr at the same temperature.
The pressure was reduced to r, and the reaction was carried out for 30 minutes.

Next, the temperature was gradually raised to 220°C and reacted for 60 minutes.
80% of the theoretical amount of phenol was distilled off. Thereafter, the pressure was reduced to 10 Torr at the same temperature and the reaction was carried out for 30 minutes, and the temperature was gradually raised to 270°C and the reaction was carried out for 30 minutes. Further, the pressure was reduced to 5 Torr at the same temperature, and the reaction was allowed to proceed for 30 minutes. Almost all of the theoretical amount of phenol was distilled out through the reaction up to this point, and the precondensation was completed.

Next, they were tightened at the same temperature for 2 hours at 0.1 to 0.3 Torr. After the product polymer was taken out and cooled under nitrogen, the solution viscosity was measured at 200C using dichloromethane as a solvent. The viscosity average molecular weight Mv calculated from the second value was 18,800.

DSC (differential scanning calorimeter; Perkin-Elmer 2C type) revealed that the glass transition point was Tg = 141°C. Furthermore, when the photoelastic constant was measured, C = 38Brews
ters (10” m2/N).

The equipment used for measurement was a DSC;
Scanning Calorimeter Perkin-E1me
r 2C type, the photoelastic constant was measured using a self-made one, but the method for calculating the photoelastic constant was a test piece (5 mm x 100 m
Tensile stresses of different magnitudes (m x 1 mm) were applied in the longitudinal direction, the generated birefringence was measured, each value was substituted into the above equation (1), and the photoelastic constant was determined from the slope. In fact, 2
, 2-bis-(4,hydroxyphenyl)propane polycarbonate has a photoelastic constant of C=82 Brew
sters (10-12 m2/N).

The viscosity average molecular weight was evaluated by measuring the intrinsic viscosity [rr] of a methylene chloride solution at 20°C using an Ubbelohde viscometer, and calculating the viscosity average molecular weight Mv using the following formula.

[rll = 1.11 x 1.0-4 (Mv)0
．． 82 surface hardness was evaluated according to JIS-5401.

The water absorption rate was evaluated according to ASTM D 570-63.

The results are shown in Table 1.

Example 2 222 parts (50 mo1%) of 1.1-bis(4-hydroxy, 3-tert-butylphenyl)cyclohexane and 174 parts (50 mo1%) of 1,1-bis(4-hydroxyphenyl)-1-phenylethane and 264 parts of diphenyl carbonate were placed in a 31-liter flask, and after repeating degassing and nitrogen purge 5 times, they were placed in a silicon bath at 160°C.
The mixture was melted while introducing nitrogen. Once melted, add a solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (3 x 10-3 mo1% amount based on the total amount of bisphenol charged), and heat at 160°.
The mixture was stirred and incubated under C, N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 17,800.

The results are shown in Table 1.

Example 3 222 parts (50 mo1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 208 parts (50 mo1%) of 1,4-bis(4-hydroxy-1,isopropylidenephenyl)benzene ) and 264 parts of diphenyl carbonate were placed in a three-way flask and degassed.

After repeating nitrogen purge 5 times, silicon bath 160°
The mixture was melted at C while introducing nitrogen. Once melted, add a solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (2×10-3 mo1% amount based on the total amount of bisphenol charged), and heat at 160°C.
The mixture was stirred and incubated under N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 19,400.

The results are shown in Table 1.

Example 4 222 parts (50 mo1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 208 parts (50 mo1%) of 1,3-bis(4-hydroxy-1-isopropylidenephenyl)benzene ) and 264 parts of diphenyl carbonate were placed in a three-way flask and degassed.

After repeating nitrogen purge 5 times, silicon bath 160°
The mixture was melted at C while introducing nitrogen. Once melted, add a solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (2×10-3 mo1% amount based on the total amount of bisphenol charged), and heat at 160°C.
The mixture was stirred and incubated under N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 18,200.

The results are shown in Table 1.

Example 5 222 parts (50 mo1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane, 161 parts (50 mo1%) of 1,1-bis(4-hydroxyphenyl)cyclohexane, and 264 parts of diphenyl carbonate After putting 31 parts into a three-way flask, degassing and purging with nitrogen five times, the mixture was melted in a silicon bath at 170°C while nitrogen was being introduced. Once melted, add a solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (3 times the total amount of bisphenol charged).
170°C, N
The mixture was stirred and brewed for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 17,500.

The results are shown in Table 1.

Example 6 222 parts (50 mo 1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 2,2-bis(4-hydroxy-3-methylphenyl)
154 parts of propane (50 mo1%) and 264 parts of diphenyl carbonate were placed in a 31 molar flask, and after repeating degassing and nitrogen purging 5 times, a silicon bath was heated at 160°C.
The mixture was melted while introducing nitrogen. Once melted, carbonate f! A solution of potassium borohydride, which is an rS catalyst, dissolved in phenol in advance (3 x 10-3 mo1% amount based on the total amount of bisphenol charged) was added, and 1
The mixture was stirred and incubated at 60°C under N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 18,000.

The results are shown in Table 1.

Example 7 222 parts (50 mo1%) of 1,1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 204 parts (50 mo1) of 2,2-bis(4,hydroxy-3-tert-butylphenyl)propane %) and 264 parts of diphenyl carbonate were placed in a three-way flask and degassed.

After repeating nitrogen purge 5 times, silicon bath 160°
The mixture was melted at C while introducing nitrogen. Once melted, add a solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (4X10-3 mo1% amount based on the total amount of bisphenol charged), and heat at 160°C.
The mixture was stirred and incubated under N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 18,500.

The results are shown in Table 1.

Example 8 222 parts (50 mo1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 171 parts (50 mo1) of 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane %) and 264 parts of diphenyl carbonate were placed in a 31-mL flask, and after repeating degassing and nitrogen purging 5 times, a silicon bath of 16.
It was melted at 0°C while nitrogen was being introduced. Once melted,
A solution of potassium borohydride, which is a carbonation catalyst, dissolved in phenol (4×10-3 mo1% amount based on the total amount of bisphenol charged) was added, and the mixture was heated to 160°
The mixture was stirred and incubated under C, N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 17,500.

The results are shown in Table 1.

Example 9 222 parts (50 mo 1%) of 1.1-bis(4-hydroxy-3-tert-butylphenyl)cyclohexane and 1,4-bis(3,5-dimethyl-4-hydroxy-1
-isopropylidenephenyl)benzene 242 parts (50
MO1%) and diphenylcarbohydrate) 264 parts to 31
The mixture was placed in a three-necked flask, and after repeating degassing and nitrogen purging five times, it was melted in a silicon bath at 160°C while nitrogen was introduced. Once melted, add a solution of potassium borohydride, the carbonation catalyst, dissolved in phenol (
4X10-3mo based on the total amount of bisphenol charged
1% amount) was added and stirred and incubated at 160°C under N2 for 30 minutes.

The following was the same as in Example 1.

The viscosity average molecular weight Mv was 18,600.

The results are shown in Table 1.

Comparative example Commercially available bisphenol A polycarbonate was used.

(Evaluation of recording properties) A recording film was attached to the polycarbonate copolymer produced as described above, and the optical recording properties were evaluated. That is, Example 1
-9.
Diameter 130m using Meiki Seisakusho Guina Melter)
A sputtering device (RF sputtering device, manufactured by Japan Vacuum Co., Ltd.) was formed using a Tb23.5Fe64□Co, 23 (atomic%) alloy target on the second substrate. ) in which the magneto-optical recording film is placed 1
,000 people formed.

On this recording film, there is
The inorganic glass protective films i and ooo described in No. 9 were formed using the same sputtering apparatus as above. The performance of the obtained magneto-optical disk was determined by the CN ratio, BER and 60°C9.
Evaluation was made based on the rate of change in CN ratio under the condition of 0RH%. The results are shown in Table 2.

(Effects of the Invention) The copolycarbonate polymer of the present invention exhibits superior optical properties compared to conventional bisphenol A polycarbonate, and has high heat resistance, excellent surface hardness, and water absorption, so it can be widely used. It can be used as a resin for optical materials.

Furthermore, as is clear from the results in Table 2, the residual carbonate copolymer according to the present invention has a lower birefringence value due to the lower birefringence value.
It can be seen that the N ratio is significantly improved and the durability is also excellent. Since it has a small photoelastic constant, it is useful for optical information recording disks in which symbols are recorded using laser beams or recorded signals are read out by reflection or transmission of laser beams.

Claims (1)

[Claims] It has repeating units represented by the following formulas (I) and (II), the mole fraction of the repeating unit (I) is 1 to 99 mol%, and the repeating unit (II) The molar fraction of is 99-1
A resin for optical materials consisting of mol% aromatic polycarbonate. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) [In the formula, X is a single bond, alkylene with 1 to 8 carbon atoms, alkylidene with 2 to 9 carbon atoms, -O-(CH_
2) ＿l-O-, ▲There are mathematical formulas, chemical formulas, tables, etc.▼,
-O-, -S-, -SO-, -SO_2-, -CO-,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼
, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R_1 to R_4 each represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group, and a halogen atom. ]