JPH0570582A - Modified polycarbonate - Google Patents

Abstract

PURPOSE:To improve transparency and heat resistance by reacting biphenol bischloroformate with a bisphenol. CONSTITUTION:A modified polycarbonate of formula III (wherein R1 and R2 are each H, lower alkyl, or trifluoromethyl provided that they may combine with each other to form a ring; and n is a positive integer) having an average mol.wt. of 20,000-100,000 is prepd. by dissolving 1mol of biphenol bischloroformate of formula I in an org. solvent such as methylene chloride or in a mixture thereof with water, adding an aq. soln. contg. both 0.9-1.1mol of a bisphenol and 1.8-2.2 mol of an alkali hydroxide, dropwise or in several portions at 0-50 deg.C to the bischloroformate soln., and reacting the bischloroformate with the bisphenol for 2-10hr.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a modified polycarbonate having excellent heat resistance.

[0002]

2. Description of the Related Art Conventionally, polymethylmethacrylate resin having high transparency has been used as a core material of a plastic optical fiber. However, the heat resistance is not sufficient for using this plastic optical fiber as an optical transmission line material for automobiles or as an information transmission line material for consumer equipment. In addition, heat resistance has come to be required for optical parts such as lenses, and conventional polycarbonate has been insufficient.

By the way, a copolymer of biphenol and bisphenol is disclosed in JP-A-62-15322. However, this copolymer was a random copolymer and was not satisfactory in terms of heat resistance and transparency.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a modified polycarbonate having excellent transparency and heat resistance.

[0005]

The above-mentioned object of the present invention is represented by the formula (I)

[Chemical 2] (In the formula, R ₁ and R ₂ each represent a hydrogen atom, a lower alkyl group (preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl, ethyl, propyl or butyl group) or a trifluoromethyl group. ₁ , R ₂ may together form a ring, n is a positive number), and an average molecular weight of 20,000 to 100,000 is achieved by a modified polycarbonate. ..

The polycarbonate of the formula (I) of the present invention can be produced, for example, according to the following reaction formula (A).

[0007]

[Chemical 3]

In the above reaction, the biphenol bischloroformate ester (1) is dissolved in an organic solvent such as methylene chloride or a mixed solvent of an organic solvent and water to prepare a bisphenol represented by the formula (2) and an alkali hydroxide such as caustic soda. The aqueous solution is added dropwise at 0 to 50 ° C or added in several batches, and then usually 2 hours to 1 until the desired molecular weight is reached.
It is performed by stirring for 0 hours.

The molar ratio of the reaction is 0.9 to 1.1 mol, preferably equimolar, of the bisphenol represented by the formula (2) to 1 mol of the biphenol bischloroformate ester of the formula (1), and the alkali hydroxide is 1 mol. 0.8 to 2.2 mol, preferably around 2 mol, and 0 to 2.
It is also possible to add 0 mol.

When the desired molecular weight is reached, the stirring can be stopped and a conventional post-treatment can be carried out to obtain the copolymer. The polycarbonate of the present invention has the following formula (B)
Can also be manufactured according to.

[0011]

[Chemical 4]

This reaction and polymerization can be carried out in the same manner as in the above reaction formula (A). The bischloroformate ester represented by the formula (1) or (3) is represented by the formula (4).
Alternatively, it can be obtained by phosgenating the compound represented by (2).

[0013]

EXAMPLES The present invention will be described in more detail based on examples.

Example 1 Biphenol bischloroformate was produced according to the following formula.

[0015]

[Chemical 5]

400 ml of tetrahydrofuran was added to a 1-liter flask equipped with a stirrer, a thermometer, and a gas introduction tube, and 140 g of phosgene was blown at -10 ° C to -5 ° C to dissolve it. Then, while stirring this, 74.4 g of biphenol was added and dissolved, and then 96.8 g of N, N-dimethylaniline was added dropwise at -5 to 0 ° C for 1 hour. After dropping, the mixture was stirred at the same temperature for 30 minutes and then gradually heated to 20 to 20.
After reacting at 25 ° C. for about 3 hours under stirring, degassing was performed. The reaction solution was poured into ice water, and the precipitated crystals were collected by filtration, washed with water, dried, and recrystallized with acetone. Yield 73.0 g (59% yield), m.p. p. = 130-1
31 ° C

Then, bisphenol A-biphenol type polycarbonate was synthesized according to the following formula.

[0018]

[Chemical 6]

To a 1 liter flask equipped with a stirrer and a thermometer, 625 ml of methylene chloride was added, and while stirring,
31.1 g of biphenol bischloroformate was added and dissolved. Further, 125 ml of ion-exchanged water was added thereto, and then a solution in which 22.8 g of bisphenol A was dissolved in 228.6 g of a 3.5% sodium hydroxide aqueous solution was added dropwise at 20 to 25 ° C. for 1 hour while sufficiently stirring. After the dropping, stirring was continued at the same temperature, and after 8 hours, the molecular weight was 30,000 (GPC,
(Converted to polystyrene), the stirring was stopped and the mixture was allowed to stand.

The aqueous layer was separated, and the methylene chloride layer was washed with ion-exchanged water, 1% hydrochloric acid and ion-exchanged water, azeotropically dehydrated and then filtered with a 0.1 μm filter. Then, the filtrate was poured into 1.2 liters of methanol, and the precipitated crystals were filtered and dried. Yield 39.5 g (yield 85%) The obtained polycarbonate was determined by ¹ H-NMR to be of formula (I)
It was confirmed to be an alternating copolymer having the structure shown in. δ (ppm): 1.70 (s, 6H), 7.20 (d,
4H) 7.27 (d, 4H), 7.35 (d, 4H) 7.59 (d, 4H)

The polycarbonate had a melting point at 252 ° C. If this is raised to a temperature above the melting point and rapidly cooled, amorphization occurs and the melting point does not appear, and the glass transition point is 16
Appeared at 5 ° C. This polycarbonate was dissolved in methylene chloride at a concentration of 5 wt%, filtered through a 0.1 μm filter, and the transmittance was measured. Transmittance at 600 nm is 10
The measurement was performed using a cm liquid cell. Results of measurement 98.
It was 1%.

Example 2 A bisphenol A-biphenol type polycarbonate was produced according to the following formula.

[0023]

[Chemical 7]

To a 1 liter flask equipped with a stirrer and a thermometer, 625 ml of methylene chloride was added, and while stirring,
35.3 g of bisphenol A bischloroformate was added and dissolved. Further, 125 ml of ion-exchanged water was added thereto, and then a solution in which 18.6 g of biphenol was dissolved in 228.6 g of a 3.5% sodium hydroxide aqueous solution was added dropwise at 20 to 25 ° C. over 1 hour while sufficiently stirring.

After the dropping, the stirring was continued at the same temperature and 4 hours later, 2
After adding 14.3 g of an 8% aqueous sodium hydroxide solution, the mixture was further stirred for 5 hours until the molecular weight became 60000 (GPC, converted to polystyrene). The stirring was stopped and the mixture was allowed to stand. The post-treatment was performed in the same manner as in Example 1. Yield 36.7 g (yield 79%) The obtained polycarbonate was ¹ H--N in the same manner as in Example 1.
According to MR, it was found to be an alternating copolymer having the structure of formula (I). This polycarbonate had a melting point at 254 ° C. If this is raised to a temperature above the melting point and rapidly cooled, amorphization occurs and the melting point does not appear, and the glass transition point is 16
Appeared at 9 ° C.

Example 3 Bisphenol AF-biphenol type polycarbonate was synthesized according to the following formula.

[0027]

[Chemical 8]

To a 1-liter flask equipped with a stirrer and a thermometer, 625 ml of methylene chloride was added, and while stirring,
31.1 g of biphenol bischloroformate was added and dissolved. Further, 125 ml of ion-exchanged water was added thereto, and then a solution in which 33.6 g of bisphenol AF was dissolved in 228.6 g of a 3.5% sodium hydroxide aqueous solution was added dropwise at 20 to 25 ° C. for 1 hour while sufficiently stirring.

After the dropping, stirring was continued at the same temperature, and after 7 hours, the molecular weight became 30,000 (GPC, converted to polystyrene), stirring was stopped and the mixture was allowed to stand. The aqueous layer is separated, and the methylene chloride layer is washed with deionized water, 1% hydrochloric acid, deionized water,
After azeotropic dehydration, it was filtered with a 0.1 μm filter.
It was then poured into 1.2 liters of methanol,
The precipitated crystals were filtered and dried. Yield 42.5 g (yield 74%) It was confirmed from ¹ H-NMR that the obtained polycarbonate was an alternating copolymer. δ (ppm): 7.35 (d, 4H), 7.37 (d,
4H) 7.47 (d, 4H), 7.61 (d, 4H) This polycarbonate had a melting point at 261 ° C.
Further, when the temperature was raised to a temperature equal to or higher than the melting point and rapidly cooled, amorphization occurred, no melting point appeared, and a glass transition point appeared at 183 ° C.

This polycarbonate was mixed with methylene chloride to give 5 parts.
It was dissolved at a concentration of wt%, filtered through a 0.1 μm filter, and then the transmittance was measured. The transmittance was 600 nm and the measurement was performed using a 10 cm liquid cell. The measurement result was 98.4%.

[0031]

Since the polycarbonate of the present invention has high transparency and a high glass transition point, it is extremely suitable as an optical material having excellent heat resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Morikuni Hasebe 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Tatsushi Sado 300 Mukonohonmachi, Takaoka, Toyama Prefecture Nippon Soda Co., Ltd. Company Takaoka factory

Claims (1)

[Claims] 1. A compound of formula (I): (In the formula, R ₁ and R ₂ are each a hydrogen atom, a lower alkyl group or a trifluoromethyl group. Further R _1,
R ₂ may together form a ring. n shows a positive number. ), And the average molecular weight is 20,000 to 10
A modified polycarbonate which is 0000.