JP2575683B2 - Polycarbonate copolymer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polycarbonate used for an optical information recording disk for recording a signal by a laser beam or reading a recorded signal by reflection or transmission of the laser beam. Related to polymers.

[Conventional technology]

DRAW, Era, in which a spot beam of a laser beam is applied to a disc and a signal is recorded in fine pits on the disc, or a signal recorded by such a pit is read out by detecting the amount of reflected or transmitted laser beam.
The sable-DRAW type optical information recording / reproducing method can significantly increase the recording density.Erasable-DRAW type, in particular, can erase / write the recording, and the image and sound quality reproduced from it have excellent characteristics. Therefore, it is expected to be widely used for recording or recording and reproducing images and sounds, recording and reproducing a large amount of information, and the like. The disk used in this recording / reproducing method is required not only to be transparent because a laser beam passes through the disk body, but also to have high optical homogeneity in order to reduce reading errors. Residual stress due to thermal stress, molecular orientation, volume change near the glass transition point, etc. generated during the cooling and flowing process of the resin during molding of the disk body is the main cause, and birefringence occurs when the laser beam passes through the disk body . The large optical non-uniformity caused by the birefringence is a fatal defect for an optical disc.

[Problems to be solved by the invention]

The birefringence caused by the thermal stress, molecular orientation, and residual stress generated during the cooling and flowing processes of the resin during the molding of the disc should be reduced significantly by choosing the molding conditions. Can be
It largely depends on the inherent birefringence of the molding resin itself, that is, the photoelastic constant.

[Means for solving the problem]

Birefringence can be expressed by the following equation (1) as the product of the photoelastic constant and the residual stress.

n ₁ −n ₂ = C (σ ₁ −σ ₂ ) (1) Obviously, if the photoelastic constant of the formula (1) is reduced, the birefringence of the obtained disk is reduced even under the same molding conditions. Thus, the inventors have determined that 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2'
By copolymerizing bis- (4-hydroxy-3-tert-butylphenyl) propane with a carbonate bond, a resin having a small photoelastic constant was obtained without impairing the mechanical properties of an aromatic polycarbonate. This has led to the present invention.

That is, the present invention relates to 4,4 '-[1,3-phenylenebis (1
-Methylethylidene) bisphenol 95 to 5 mol%, preferably 90 to 10 mol%, and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane 5 to 95 mol%, preferably 10 to 90 mol% And a repeating unit represented by the following formula (i):
Mol%, preferably 90 to 10 mol%, and a repeating unit represented by the following formula (ii) is 5 to 95 mol%, preferably 10 to 90 mol%
(Total of 100 mol% of the above two types of repeating units), and an aromatic polycarbonate copolymer having a viscosity average molecular weight of 1,000 to 100,000.

Thus, according to the present invention, the following formulas (I) and (II)
An aromatic polycarbonate polymer obtained by copolymerizing bisphenol represented by the formula (1) through a carbonate bond is obtained.

The repeating unit represented by the formula (ii) is 5 to 95 mol%. When the content of the repeating unit represented by the formula (ii) is less than 5 mol%, the photoelastic constant of the obtained aromatic polycarbonate is not much different from that of the homopolycarbonate represented by the formula (i). When the content of the repeating unit represented by the formula (ii) exceeds 95 mol%, the obtained aromatic polycarbonate becomes brittle as compared with the homopolycarbonate represented by the formula (i).

The viscosity average molecular weight of the copolymer of the present invention is 1,000 to 100,000
Is preferred, and 13,000 to 50,000 is more preferred. If it is less than 1,000, the molded article becomes brittle, and if it exceeds 100,000, the fluidity is reduced and the moldability is inferior.

There are the following two methods for producing the polycarbonate copolymer of the present invention.

Transesterification method 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol- (4-hydroxy-3-tert-butylphenyl) propane mixture, based on stoichiometric equivalent In a slight excess of diphenyl carbonate, in the presence of a normal carbonate catalyst, about 160-180
The reaction is carried out for about 30 minutes at a temperature of ℃ under a normal pressure and an inert gas is introduced.
The pre-condensation is finally completed at 10 Torr and 220 ° C. at a temperature of ° C. Thereafter, the reaction is carried out at 10 Torr and 270 ° C. for 30 minutes and at 5 Torr and 270 ° C. for 20 minutes, and then 0.5 Torr or less, preferably 0.3 Torr to 0.1 T
Post-condensation proceeds at 270 ° C. for 1.5 to 2.0 hours under reduced pressure of orr.

Incidentally, as the carbonate formation catalyst for the carbonate bond, an alkali metal or alkaline earth metal catalyst such as a lithium catalyst, a potassium catalyst, a sodium catalyst, a calcium catalyst, and a tin catalyst are suitable. Examples include lithium oxide / lithium carbonate, potassium borohydride / potassium hydrogen phosphate, sodium hydroxide / sodium borohydride, calcium hydride, dibutyltin oxide / stannous oxide. Of these, it is preferable to use a potassium-based catalyst.

Phosgene method A three-necked flask is equipped with a stirrer, thermometer, gas inlet tube, and exhaust tube. A mixture of 4,4- [1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane is dissolved in a solvent such as pyridine and dichloromethane. The phosgene gas is introduced while vigorously stirring the phosgene gas. However, since phosgene is highly toxic, it is operated in a powerful draft. In addition, sodium hydroxide 10% at the exhaust end
Attach a unit that decomposes and detoxifies excess phosgene with an aqueous solution. Phosgene is introduced into the flask from the cylinder through an empty rinse bottle, a paraffin rinse bottle (count the number of bubbles), and an empty rinse bottle. The gas inlet tube is inserted above the stirrer, and its tip is expanded in a funnel shape so as not to be clogged by the pyridine salt that precipitates.

As the gas is introduced, the hydrochloride of pyridine precipitates and the content becomes cloudy. Water cooling is performed so that the reaction temperature becomes 30 ° C. or less.
It becomes viscous with the progress of condensation. Pass phosgene until the yellow color of the phosgene-hydrogen chloride complex does not disappear. After completion of the reaction, methanol is added to precipitate a polymer, which is separated by filtration and dried. The resulting polycarbonate is soluble in methylene chloride, pyridine, chloroform, tetrahydrofuran and the like, and is purified by reprecipitation from these solutions with methanol.

The polycarbonate copolymer thus obtained is useful for a DRAW, E-DRAW type optical information recording disc for recording a signal with a laser beam or reading a recorded signal by reflection or transmission of a laser beam. .

〔Example〕

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

 The parts and percentages are based on weight.

Example 1 374 parts (90 mol%) of 4,4- [1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane 41 Parts (10 mol%) and 264 parts of diphenyl carbonate were placed in a three-necked flask, and after degassing and nitrogen purging were repeated 5 times, they were melted in a silicon bath at 160 ° C. while introducing nitrogen. After melting, a solution in which potassium borohydride, a carbonate catalyst, was previously dissolved in phenol (10 ⁻³ mol based on the total amount of bisphenol charged)
l% weight) was added, 160 ° C., and foster stirred under N ₂ for 30 minutes. Next, the pressure was reduced to 100 Torr at the same temperature, and the mixture was stirred for 30 minutes. Thereafter, the pressure was further reduced to 50 Torr at the same temperature, and the reaction was performed for 30 minutes. Next, the temperature was gradually raised to 220 ° C., and the reaction was carried out for 60 minutes to distill out 80% of the theoretical amount of phenol distillation. After that, 10 Torr at the same temperature
The temperature was gradually raised to 270 ° C. and the reaction was carried out for 30 minutes. Further, at the same temperature, the pressure was reduced to 5 Torr, and the reaction was carried out for 30 minutes. In the reaction so far, almost all of the theoretical amount of phenol was distilled off, and the precondensation was completed. Next, at the same temperature, 0.1-0.3
Condensed after 2 hours at Torr. After removing and cooling the product polymer under nitrogen, the solution viscosity was measured at 20 ° C. using dichloromethane. The viscosity average molecular weight v calculated from this value was 25,000. When the IR spectrum was measured, characteristic absorption of a carbonate bond was observed at 1760 to 1800 cm ^-1 (FIG. 1). When measured by ¹ H-NMR, it was 1.37 ppm
Absorption of methyl group hydrogen of tertiary butyl group, 1.64pp
The absorption of methyl group hydrogen of propane was observed at m, and the absorption derived from phenyl group was observed at 6.80 to 7.25 ppm (FIG. 2). Also DSC
(Differential scanning calorimeter; Perkin-Elmer2C type) has a glass transition point of Tg = 103 ℃
It turned out to be. When the photoelastic constant is further measured, C
= It was found to be ^{60Brewsters (10 -12 m 2 / N} ). The polymer produced from the integrated value of NMR was 4,4 '-[1,3-
[Phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-phenyl) propane were confirmed to be a 9: 1 polycarbonate copolymer.

The instrument used for the measurement was an IR spectrometer; IR-810, ¹ H-NMR manufactured by JASCO; JNM-GX-270, DSC manufactured by JEOL;
Differential scanning calorimeter Pe
rkin-Elmer2C type, the photoelastic constant was measured using a self-made one. The method of calculating the photoelastic constant was a test piece (50 mm × 10 mm
× 1 mm) were applied in the length direction, and the generated birefringence was measured. Each value was substituted into the above equation (1), and the photoelastic constant was determined from the slope. 2,2
The high elastic constant of -bis- (4-hydroxyphenyl) propane and polycarbonate is C = 82 Brewsters (10 ^-12 m ² /
N).

Example 2 A three-necked flask was equipped with a stirrer, a thermometer, a gas introduction pipe, and an exhaust pipe. 4,4- [1,3
-Phenylenebis (1-methylethylidene)] bisphenol (374 parts, 90 mol%) and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane 41 parts (10 mol%) were dissolved, and dichloromethane was added. Phosgene gas was introduced while stirring this vigorously. Phosgene was introduced into the flask from the cylinder through an empty flush bottle, a flush bottle containing water, and an empty flush bottle. Water cooling was performed so that the reaction temperature during the introduction of phosgene gas was 25 ° C or less. The solution becomes viscous as the condensation proceeds. Further, phosgene was passed until the yellow color of the phosgene-hydrogen chloride complex did not disappear. After the reaction, pour the reaction solution into methanol,
The mixture was filtered and washed with water. The produced polycarbonate was purified by reprecipitation from a solution of dichloromethane in methanol.

After drying well after purification, the solution viscosity was measured at 20 ° C. using dichloromethane. The viscosity average molecular weight v calculated from this value was 27,500. Example 1
As a result of the same instrumental analysis as in Example 1, the same result as in Example 1 was obtained, and the produced polymer was 4,4 '-[1,3
-Phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane in a 9: 1 polycarbonate copolymer.

Example 3 208 parts (50 mol%) of 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane 204 parts (50 mol%) and 264 parts of diphenyl carbonate were placed in a three-necked flask, and after degassing and nitrogen purging were repeated 5 times, they were melted in a silicon bath at 160 ° C. while introducing nitrogen. After melting, a solution in which potassium borohydride, a carbonate catalyst, was previously dissolved in phenol (10 ⁻³ mol based on the total amount of bisphenol charged)
l% weight) was added, 160 ° C., and foster stirred under N ₂ for 30 minutes. Next, the pressure was reduced to 100 Torr at the same temperature, and the mixture was stirred for 30 minutes. Then, the pressure was further reduced to 50 Torr at the same temperature, and the reaction was performed for 60 minutes. Next, the temperature was gradually raised to 220 ° C., and the reaction was carried out for 60 minutes. In the reaction so far, 80% of the theoretical amount of phenol was distilled off. After a while
At the same temperature, reduce the pressure to 10 Torr and react for 30 minutes.
The temperature was raised to 270 ° C and reacted for 30 minutes. Further, at the same temperature, the pressure was reduced to 5 Torr, and the reaction was carried out for 30 minutes. Next, at the same temperature, 0.1-0.3
Condensed after 2 hours at Torr. After removing the product polymer under nitrogen and cooling, the solution viscosity was measured at 20 ° C. using dichloromethane as a solvent. The viscosity average molecular weight v calculated from this value was 25,000. When the IR spectrum was measured, characteristic absorption of a carbonate bond was observed at 1750 to 1800 cm ^-1 (FIG. 3). When ¹ H-NMR was measured, 1.3
Absorption of methyl group hydrogen of tertiary butyl group to 8 ppm, 1.
Absorption of methyl hydrogen of propane at 64,1.70 ppm, 6.9-7.3 ppm
The absorption derived from the phenyl group was observed in ppm (FIG. 4).
DSC showed that the glass transition point was Tg = 111 ° C. Further measurement of the high elastic constant shows that C = 39 Brewsters (1
0 ^-12 m ² / N). The polymer formed from the integrated value of NMR was 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane. It can be confirmed that this is a 1: 1 polycarbonate copolymer.

Example 4 A three-necked flask was equipped with a stirrer, a thermometer, a gas introduction pipe, and an exhaust pipe. 4,4'- in 10% aqueous sodium hydroxide
[1,3-Phenylenebis (1-methylethylidene)] 208 parts (50 mol%) of bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane
After dissolving 204 parts (50 mol%), dichloromethane was added, and phosgene gas was introduced with vigorous stirring. The phosgene is supplied from an empty gas bottle, a water bottle,
It was introduced into the flask through an empty flush bottle. Water cooling was performed so that the reaction temperature during the introduction of phosgene gas was 25 ° C or less. The solution becomes viscous as the condensation proceeds. Further, phosgene was passed until the yellow color of the phosgene-hydrogen chloride complex did not disappear. After completion of the reaction, the reaction solution was poured into methanol, separated by filtration, and repeatedly washed with water. The produced polycarbonate was purified by reprecipitation from a solution of dichloromethane in methanol.

After drying well after purification, the solution viscosity was measured at 20 ° C. using dichloromethane. The viscosity average molecular weight v calculated from this value was 31,000. Example 3
The same results as in Example 3 were obtained by performing an instrumental analysis in the same manner as in Example 3. Thus, the produced polymer was 4,4 '-[1,3
[Phenylenebis (1-methylethylidene)]] can be confirmed to be a 1: 1 polycarbonate copolymer of bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane.

Example 5 63 parts (15 mol%) of 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis-
(4-hydroxy-3-tert-butylphenyl)
347 parts (85 mol%) of propane and 26 of diphenyl carbonate
Four parts were placed in a three-necked flask, and after degassing and nitrogen purging were repeated 5 times, melting was performed while introducing nitrogen in a silicon bath at 160 ° C. Once melted, a solution of potassium borohydride, a carbonate catalyst, previously dissolved in phenol (10 ^-3 mol% based on the total amount of bisphenol charged)
Volume), and the mixture was stirred and brewed at 160 ° C. under N _{2 for} 30 minutes. Next, the pressure was reduced to 100 Torr at the same temperature, and the mixture was stirred for 30 minutes. Then, the pressure was further reduced to 50 Torr at the same temperature, and the reaction was performed for 60 minutes. Next, the temperature was gradually raised to 220 ° C., and the reaction was carried out for 60 minutes. In the reaction so far, 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.
The temperature was raised to 0 ° C and reacted for 30 minutes. Further, at the same temperature, the pressure was reduced to 5 Torr, and the reaction was carried out for 30 minutes. Next, at the same temperature, 0.1 to 0.3 To
Condensed after 2 hours at rr. After removing the product polymer under nitrogen and cooling, the solution viscosity was measured at 20 ° C. using dichloromethane as a solvent. The viscosity average molecular weight v calculated from this value was 26,700. When the IR spectrum was measured, characteristic absorption of a carbonate bond was observed at 1720 to 1820 cm ⁻¹ (FIG. 5). When ¹ H-NMR was measured, it was 1.39p
Absorption of methyl tertiary butyl hydrogen at pm, 1.6
Absorption of methyl hydrogen of propane at 4,1.70 ppm, 6.95 to 7.2
Absorption derived from the phenyl group was observed at 8 ppm (FIG. 6).
The DSC showed that the glass transition point was Tg = 118 ° C. When the photoelastic constant was further measured, C = 28 Brewsters (1
0 ^-12 m ² / N). The polymer formed from the integrated value of NMR was 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane. 3:17, which is a polycarbonate copolymer.

Example 6 A three-necked flask was equipped with a stirrer, a thermometer, a gas introduction pipe, and an exhaust pipe. 4,4'- in 10% aqueous sodium hydroxide
[1,3-phenylenebis (1-methylethylidene)] 63 parts (15 mol%) of bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane 34
Seven parts (85 mol%) were dissolved, dichloromethane was added, and phosgene gas was introduced with vigorous stirring. Phosgene was introduced into the flask from the cylinder through an empty flush bottle, a flush bottle containing water, and an empty flush bottle. Water cooling was performed so that the reaction temperature during the introduction of phosgene gas was 25 ° C or less.
The solution becomes viscous as the condensation proceeds. Further, phosgene was passed until the yellow color of the phosgene-hydrogen chloride complex did not disappear. After completion of the reaction, the reaction solution was poured into methanol, separated by filtration, and repeatedly washed with water. The produced polycarbonate was purified by reprecipitation from a solution of dichloromethane in methanol.

After drying well after purification, the solution viscosity was measured at 20 ° C. using dichloromethane. The viscosity average molecular weight v calculated from this value was 29,500. Example 5
As a result of the same instrumental analysis as in Example 5, the same results as in Example 5 were obtained. The resulting polymer was 4,4 '-[1,3
-Phenylenebis (1-methylethylidene)] bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane in a 3:17 polycarbonate copolymer.

〔The invention's effect〕

Since the polycarbonate copolymer of the present invention has a small photoelastic coefficient, it is useful for an optical information recording disc for recording a signal by a laser beam or reading a recorded signal by reflection or transmission of the laser beam.

[Brief description of the drawings]

1, 3, and 5 are IR spectra of the copolymers of the present invention obtained in Examples 1, 3, and 5, respectively. FIGS. 2, 4, and 6 are Examples 1, 3, and 5, respectively. 3 is an NMR spectrum of the obtained copolymer of the present invention.

Claims (1)

(57) [Claims] 1. A carbonate bond between 4,4 '-[1,3-phenylenebis (1-methylethylidene) bisphenol and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane. 95 to 5 mol% of a repeating unit represented by the following formula (i) and 5 to 95 mol% of a repeating unit represented by the following formula (ii) (100 mol in total of the above two kinds of repeating units). %), And an aromatic polycarbonate copolymer having a viscosity average molecular weight of 1,000 to 100,000.