JP2565718B2 - Polycarbonate copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) This invention relates to 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane and 1,1-
The present invention relates to a polycarbonate copolymer having bis (4-hydroxyphenyl) -1-phenylethane (hereinafter referred to as bisphenol AP) as a divalent phenol component and having excellent heat resistance and transparency. Further, the present invention relates to a polycarbonate copolymer 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 a laser beam.

(Prior Art) DRAW, Era in which a spot beam of a laser beam is applied to a disc and signals are recorded in the disc with fine pits, or a signal recorded by such pits is read out by detecting the amount of reflected or transmitted light of the laser beam.
The sable-DRAW type optical information recording / reproducing system can remarkably increase the recording density, and in particular, the Erasable-DRAW type is capable of erasing / writing records and has excellent characteristics of images and sound quality reproduced from them. Therefore, it is expected to be widely used for recording or recording / reproducing images and sounds, recording / reproducing a large amount of information, and the like. The disc used in this recording / reproducing system is not only transparent because the laser beam passes through the disc body, but also strongly required to have optical homogeneity in order to reduce reading errors. Birefringence occurs when the laser beam passes through the disk body, mainly due to residual stress due to thermal stress, molecular orientation, volume change near the glass transition point, etc. generated during resin cooling and flow process during disk body molding. . The large optical nonuniformity due to this birefringence is a fatal defect for an optical disc.

(Problems to be Solved by the Invention) Birefringence mainly caused by thermal stress, molecular orientation, and residual stress generated in the cooling and flowing processes of the resin at the time of molding the disc is as follows. The birefringence of the resulting disc can be made quite small,
It greatly depends on the intrinsic birefringence of the molding resin itself, that is, the photoelastic constant.

(Means for Solving the Problems) The 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) n ₁ −n ₂ : birefringence σ ₁ −σ ₂ : residual stress C: photoelastic constant If the photoelastic constant of equation (1) is reduced, It is apparent that the birefringence of the obtained disk is reduced even under the same molding conditions.

Therefore, the inventors have found that the formula (I ′) 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-fetanylethane represented by the formula (I
I ′) The present invention was accomplished by finding the fact that a resin having a small photoelastic constant can be obtained by copolymerizing bisphenol AP represented by the formula (3) with a carbonate bond without impairing the mechanical properties of the aromatic polycarbonate.

That is, the present invention provides 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane with 99-
The present invention relates to an aromatic polycarbonate copolymer obtained by carbonate-bonding 1 mol% and 1-99 mol% of bisphenol AP.

Thus, the present invention is an aromatic polycarbonate having two kinds of the following repeating unit (I) and repeating terminal (II), The constituent mole fraction of the repeating unit (I) is from 1 to 99 mol%.

When the structural unit of the formula (I) is less than 1 mol%, the photoelastic constant of the obtained aromatic polycarbonate is not much different from that of the homopolycarbonate of the formula (II). When the content of the constituent unit of the formula (I) exceeds 99 mol%, the glass transition point of the aromatic polycarbonate obtained is remarkably lower than that of the homopolycarbonate of the formula (II).

The viscosity average molecular weight of the copolymer of the present invention is 10,000 to 100,00
0 is preferable, and 13,000 to 50,000 is more preferable. 10,000
If the amount is less than 100%, the molded product becomes brittle, and if it exceeds 100,000, the fluidity is lowered and the moldability is deteriorated, and neither is suitable as a molding resin or an optical disk resin.

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

Transesterification method A mixture of 1,1-bis (4-hydroxy-3-tertiarybutylphenyl) -1-phenylethane and bisphenol AP, in contrast to diphenyl carbonate in a stoichiometrically slightly excess amount, In the presence of a carbonation catalyst, the reaction is carried out at a temperature of about 160 to 180 ° C under atmospheric pressure for about 30 minutes under the condition of introducing an inert gas, and the pressure is gradually reduced over 2 hours at a temperature of about 180 to 220 ° C. Finally 10 Torr, 220 ℃
Ends the precondensation. Then, at 10 Torr, 270 ° C for 30 minutes, 5T
The reaction is conducted at 270 ° C. for 20 minutes, and then the condensation is carried out at 270 ° C. for 1.5 hours to 2.0 hours under a reduced pressure of 0.5 Torr or less, preferably 0.3 Torr to 0.1 Torr.

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

Phosgene method Attach a stirrer, thermometer, gas inlet pipe, and exhaust pipe to a three-necked flask. A mixture of 1,1-bis (4-hydroxy-3-tertiarybutylphenyl) -1-phenylethane and bisphenol AP is dissolved in a solvent such as pyridine or dichloromethane, and phosgene gas is introduced with vigorous stirring. However, since phosgene is extremely poisonous, it is operated in a powerful draft. A unit for decomposing and detoxifying excess phosgene with an aqueous solution of 10% sodium hydroxide is attached to the exhaust end. Phosgene is introduced into the flask from a cylinder through an empty gas bottle, a gas bottle containing paraffin (count the number of bubbles), and an empty gas bottle. The gas inlet tube should be inserted on top of the stirrer, and the tip should be spread out in a funnel shape so as not to be clogged with the precipitated pyridine salt.

As the gas is introduced, the hydrochloride of pyridine precipitates and the content becomes cloudy. Water-cool the reaction temperature to 30 ° C or less.
It becomes viscous as the condensation progresses. Pass phosgene until the yellow color of the phosgene-hydrogen chloride complex no longer disappears. After completion of the reaction, methanol is added to precipitate the polymer, which is filtered and dried. The resulting polycarbonate is soluble in methylene chloride, pyridine, chloroform, tetrahydrofuran and the like, and is purified from these solutions by reprecipitation with methanol.

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

(Examples) 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 48 parts (10 mol%) of 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane, 314 parts (90 mol%) of bisphenol AP and 264 parts of diphenyl carbonate were placed in a 3 l three-necked flask. After charging, degassing, and nitrogen purging were repeated 5 times, the silicon bath was melted at 180 ° C. while introducing nitrogen. Once melted, a solution of potassium carbonate borohydride, which is a carbonation catalyst, in phenol beforehand (10 ^-3 mol relative to the total amount of bisphenol charged).
%) Was added, and the mixture was stirred at 180 ° C. under N _{2 for} 30 minutes to cultivate it. Next, the pressure was reduced to 100 Torr at the same temperature, and the mixture was stirred for 30 minutes, then further reduced to 50 Torr at the same temperature, and reacted for 30 minutes. Next, the temperature was gradually raised to 220 ° C. and the reaction was carried out for 60 minutes to distill 80% of the theoretical amount of phenol distilled. Thereafter, the pressure was reduced to 10 Torr at the same temperature and the reaction was carried out for 30 minutes, 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, post-condensation was performed at the same temperature for 2 hours at 0.1 to 0.3 Torr.
After taking out the polymer of the product under nitrogen and cooling it, the solution viscosity was measured at 20 ° C. using dichloromethane as a solvent. The viscosity average molecular weight v calculated from this value was 23,400.

When the IR spectrum was measured, characteristic absorption of carbonate bond was observed at 1,760 to 1,810 cm ^-1 (FIG. 1). Also ¹ H−
When NMR was measured, absorption of methyl group hydrogen of tertiary butyl group was observed at 1.3 ppm, absorption of methyl group hydrogen of phenylethane at 2.2 ppm, and absorption derived from phenyl group at 7.2 to 7.5 ppm (FIG. 2). Further, it was found from DSC (Differential Scanning Calorimeter; Perkin-Elmer 2C type) that the glass transition point was Tg = 176 ° C. Further measuring the photoelastic ^{constant, C = 52Brewsters (10- 12 m} 2 /
N). In addition, the polymer generated from the integrated value of NMR is a polycarbonate copolymer in which 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane and bisphenol AP are 1: 9 (molar ratio). It can be confirmed that

Instruments used for measurement were IR spectrometer; IR-810, ¹ H-NMR manufactured by JASCO; JNM-MH-100, DS manufactured by JEOL
C: Differential scanning calorimeter
The Perkin-Elmer 2C type, the photoelastic constant was measured using a self-made one, and the calculation method of the photoelastic constant was a test piece (5 mm × 100
(mm × 1 mm) was 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
- bis - (4-hydroxyphenyl) photoelastic constant of the polycarbonate of propane, C = 82Brewsters (10- ¹² m
² / N). The results are shown in Table 1.

To evaluate the viscosity average molecular weight, the intrinsic viscosity [η] of a methylene chloride solution at 20 ° C. was measured using an Ubbelohde viscometer, and the viscosity average molecular weight v was calculated using the following formula.

[Η] = 1.11 × 10- 4 (v) 0.82 Stirring machine necked flask of Example 2 1l, thermometer, gas inlet tube, put an exhaust pipe. 1,1-bis (4-
Hydroxy-3-tert-butylphenyl) -1-phenylethane 4.8 parts (10 mol%) and bisphenol AP31.4
Part (90 mol%) was melted, and phosgene gas was introduced while vigorously stirring this. Phosgene was introduced into the flask from the cylinder through an empty gas bottle, a water bottle containing water, and an empty gas bottle. The reaction temperature during the introduction of phosgene gas was water-cooled to 25 ° C or lower. The solution becomes viscous as the condensation progresses. 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. Further, the produced polycarbonate was purified by reprecipitation from a solution of dichloromethane in methanol.

After purification and drying well, the viscosity of the mucus was measured at 20 ° C. using dichloromethane as a solvent. The viscosity average molecular weight v24,000 calculated from this value was obtained. Further, when the instrumental analysis was performed in the same manner as in Example 1, the same results as in Example 1 were obtained, and thus the produced polymer was
-Hydroxy-3-tert-butylphenyl) -1-
Phenylethane and bisphenol AP 1: 9 (molar ratio)
It can be confirmed that it is a copolymer of polycarbonate.

Example 3 240 parts (50 mol%) of 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane, 174 parts (50 mol%) of bisphenol AP and 264 parts of diphenyl carbonate were added to a 3 l three-necked flask. After repeating degassing and nitrogen purging 5 times, the silicon bath was melted at 170 ° C. while introducing nitrogen. Once melted, a solution of potassium borohydride, which is a carbonation catalyst, in phenol beforehand (3 x 10 based on the total amount of bisphenol charged).
^-3 mol% amount) was added and the mixture was stirred for 30 minutes at 170 ° C under N ₂ .

 Hereinafter, it was the same as in Example 1.

 The viscosity average molecular weight v was 25,000.

When the IR spectrum was measured, characteristic absorption of carbonate bond was observed at 1,760 to 1,810 cm ^-1 . Further, when ¹ H-NMR was measured, absorption of methyl group hydrogen of tertiary butyl group at 1.3 ppm, absorption of methyl group hydrogen of phenylethane at 2.2 ppm, and absorption derived from phenyl group at 7.0 to 7.3 ppm were observed. . Further, DSC revealed that the glass transition point was Tg = 167 ° C. Furthermore, when the photoelastic constant is measured, C = 40 Brewst
It was found to be ^{ers (10- 12 m 2 / N} ). Further, the polymer generated from the integrated value of NMR is a polycarbonate copolymer of 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane and bisphenol AP at a ratio of 5: 5 (molar ratio). It can be confirmed that

Example 4 A stirrer, a thermometer, a gas introduction pipe, and an exhaust pipe are attached to a 1-liter three-necked flask. 1,1-bis (4-
Hydroxy-3-tert-butylphenyl) -1-phenylethane 24 parts (50 mol%) and bisphenol AP17.4
Part (50 mol%) was melted, and phosgene gas was introduced while vigorously stirring this.

 Hereinafter, the same as Example 2 was performed.

The viscosity average molecular weight v was 24,000. In addition, when the instrumental analysis was performed in the same manner as in Example 3, the same results as in Example 3 were obtained. Therefore, the produced polymer was 1,1-bis (4-hydroxy-3-tert-butylphenyl).
It can be confirmed that the copolymer is a 1: 1 (molar ratio) polycarbonate of 1-phenylethane and bisphenol AP.

Example 5 1,1-bis (4-hydroxy-3-tert-butylphenyl) -1-phenylethane 432 parts (90 mol%), bisphenol AP 35 parts (10 mol%) and diphenyl carbonate 264 parts were added to a 3 l three-necked flask. After degassing and nitrogen purging were repeated 5 times, the mixture was melted in a silicon bath at 160 ° C. while introducing nitrogen. After melting, a solution in which potassium borohydride as a carbonate-forming catalyst was previously dissolved in phenol (5 × 10 5 based on the total amount of bisphenol charged)
^-3 mol% amount) was added and the mixture was agitated for 30 minutes at 160 ° C. under N ₂ .

 Hereinafter, it was the same as in Example 1.

 The viscosity average molecular weight v was 22,600.

When the IR spectrum was measured, characteristic absorption of carbonate bond was observed at 1,760 to 1,810 cm ^-1 . When ¹ H-NMR is measured, absorption of hydrogen of methyl group of tertiary butyl group is observed at 1.4 ppm, absorption of hydrogen of methyl group of phenylethane at 2.2 ppm, and absorption derived from phenyl group at 7.0 to 7.4 ppm. did. Further, DSC revealed that the glass transition point was Tg = 160 ° C. Furthermore, when the photoelastic constant is measured, C = 29 Brew
It was found to be ^{sters (10- 12 m 2 / N} ). Also, NMR
The polymer generated from the integrated value of is a polycarbonate copolymer of 1,1-bis (4-hydroxy-3-tertiarybutylphenyl) -1-phenylethane and bisphenol AP of 9: 1 (molar ratio). Can be confirmed.

Example 6 A 1-liter three-necked flask is equipped with a stirrer, a thermometer, a gas introduction pipe, and an exhaust pipe. 1,1-bis (4-
43.2 parts (90 mol%) of hydroxy-3-tert-butylphenyl) -1-phenylethane and 4 parts (10 mol%) of bisphenol AP were dissolved, and phosgene gas was introduced while vigorously stirring this.

 Hereinafter, the same as Example 2 was performed.

The viscosity average molecular weight v was 21,400. Further, when the instrumental analysis was performed in the same manner as in Example 5, the same results as in Example 5 were obtained. Therefore, the produced polymer was 1,1-bis (4-hydroxy-3-tert-butylphenyl).
It can be confirmed that it is a copolymer of 9: 1 (molar ratio) polycarbonate of -1-phenylethane and bisphenol AP.

Comparative Example 1 273 parts of 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) was added to diphenyl carbonate 2
64 parts were placed in a 3 l three neck flask. Hereinafter, the same as Example 1 was performed. The results are shown in Table 1.

(Effect of the Invention) The copolymerized polycarbonate polymer of the present invention exhibits excellent optical properties and has high heat resistance and transparency, so that it can be widely used as an optical material.

Further, since the photoelastic constant is small, it is useful for an optical information recording disc for recording a symbol by a laser beam or reading a recorded signal by reflection or transmission of the laser beam.

[Brief description of drawings]

Figures 1,3,5 are IR spectra of the copolymers of the present invention obtained in Examples 1,3,5 respectively, and Figures 2,4,6 are Examples 1,3,5 respectively.
¹ is a ¹ H-NMR spectrum of the copolymer of the present invention obtained in ¹ ).

Claims (1)

(57) [Claims] (1) a repeating unit represented by the following formulas (I) and (II), and a molar ratio of the repeating unit represented by the formula (I) to the repeating unit represented by the formula (II) is 1: 99-9
An aromatic polycarbonate copolymer having a viscosity average molecular weight of 10,000 to 100,000 at 9: 1.