JP2001011166A - Polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polycarbonate resin having a lower photoelastic coefficient than a polycarbonate resin derived from bisphenol A and having an excellent balance between refractive index, Abbe number and heat resistance. SOLUTION: A polycarbonate resin derived from pentacyclopentadecane dimethanol and norbornane dimethanol and a carbonic acid diester.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to transparency, heat resistance,
The present invention belongs to a polycarbonate resin having a low balance between photoelastic coefficient, refractive index and Abbe number, and a method for producing the same. This polycarbonate resin can be suitably used as a material for plastic optical products such as optical disk substrates, various lenses, prisms, and optical fibers.

[0002]

2. Description of the Related Art A polycarbonate resin obtained by reacting 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A) with phosgene or a carbonic acid diester has excellent heat resistance, transparency, and impact resistance. Because of its excellent mechanical properties such as optical disc substrate, various lenses, prisms,
Widely used for optical fibers and the like.

[0003] However, the polycarbonate resin comprising bisphenol A is a low-flow material and has a high photoelastic coefficient, and therefore has a problem that birefringence due to molecular orientation and residual stress during molding is large. I have. Therefore, when molding an optical material made of a polycarbonate resin composed of bisphenol A as a raw material, a resin having a relatively low molecular weight is used to improve the fluidity, and the birefringence of the product is reduced by molding at a high temperature. A method has been implemented. However, in the case of polycarbonate resin composed of bisphenol A, there is a limit to the reduction of birefringence even when the above-mentioned means is used. Therefore, there is a strong demand for the development of a material having a lower photoelastic coefficient and a higher fluidity.

As a method for reducing the photoelastic coefficient of a polycarbonate resin, for example, Japanese Patent Application Laid-Open No. 64-66234 discloses a method.
As shown in the publication, a method of copolymerizing bisphenol A with tricyclo (5.2.1.0 ^2,6 ) decane dimethanol is known, but it causes a decrease in heat resistance,
Further, a sufficient effect in reducing the photoelastic coefficient has not been obtained.

Further, CR-39 (diethylene glycol bisallyl carbonate) is widely used as a lens material, especially as a plastic eyeglass lens material, but has a low refractive index of 1.50 and is produced from a thermosetting resin. There are problems such as poor performance, and a solution to these problems is desired.

[0006]

SUMMARY OF THE INVENTION The present invention aims to solve the problems associated with the prior art as described above, and has a lower photoelastic coefficient than a polycarbonate resin composed of bisphenol A, Another object of the present invention is to provide a polycarbonate resin having an excellent balance between refractive index, Abbe number, and heat resistance, and a method for producing the same.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for overcoming the above-mentioned problems, and as a result, they are represented by structural formulas (1), (2) and (3). The present inventors have found that a polycarbonate resin composed of a structural unit can solve the above-mentioned problems, and have reached the present invention.

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[0008]

DETAILED DESCRIPTION OF THE INVENTION The polycarbonate resin according to the present invention is derived from pentacyclopentadecane dimethanol and norbornane dimethanol and diester carbonate.

In the present invention, pentacyclopentadecane dimethanol is represented by the following general formulas (4) and (5), and includes various isomers.

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[0010] Norbornane dimethanol is represented by the following general formula (6) and includes various isomers.

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The polycarbonate resin according to the present invention contains structural units derived from pentacyclopentadecane dimethanol and norbornane dimethanol, respectively. The content of norbornane dimethanol is as follows. It is preferably from 5 to 70 mol% based on the total amount of methanol. If the content of norbornane dimethanol is less than 5 mol%, it is not preferable from the viewpoint of fluidity, and if it exceeds 70 mol%, it is not preferable from the viewpoint of heat resistance.

Examples of the carbonic diester used in the present invention include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, di-m-cresyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate and the like. Are listed.
Among these, diphenyl carbonate is particularly preferred. The carbonic acid diester used is preferably used in a ratio of 0.97 to 1.10 mol, more preferably 0.99 to 1.0 mol, per 1 mol of the total of pentacyclopentadecane dimethanol and norbornane dimethanol.
4 mole ratio.

The polycarbonate resin according to the present invention has a weight average molecular weight in terms of polystyrene of 20,000-2.
00,000, more preferably 3
It is between 000 and 130,000. If the weight average molecular weight in terms of polystyrene is less than 20,000, the strength of the molded article becomes insufficient, and if it exceeds 200,000, the fluidity at the time of molding deteriorates, which is not preferable.

In the method for producing a polycarbonate resin according to the present invention, a basic compound is used as a catalyst. Examples of such a basic compound include an alkali metal compound, an alkaline earth metal compound, a nitrogen-containing compound and a phosphorus-containing compound.

As the alkali metal compound, specifically, sodium hydroxide, potassium hydroxide, cesium hydroxide, lithium hydroxide, sodium hydrogen carbonate, sodium carbonate, potassium carbonate, cesium carbonate, lithium carbonate, sodium acetate, acetic acid Potassium, cesium acetate, lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium phenyl borohydride,
Sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, disodium phenylphosphate, sodium tetraphenylborate, sodium salt of phenol , Potassium salts, cesium salts, lithium salts and the like.

Further, as the alkaline earth metal compound,
Specifically, magnesium hydroxide, calcium hydroxide,
Strontium hydroxide, barium hydroxide, magnesium bicarbonate, calcium bicarbonate, strontium bicarbonate, barium bicarbonate, magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, magnesium acetate, calcium acetate, strontium acetate, barium acetate, stearic acid Magnesium, calcium stearate, strontium stearate, barium stearate, calcium benzoate, magnesium phenyl phosphate, phenol magnesium salt, calcium salt, strontium salt, barium salt and the like are used.

Examples of the nitrogen-containing compound and the phosphorus-containing compound include, specifically, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylbenzylammonium hydroxide and the like. Quaternary ammonium hydroxides having alkyl, aryl, alkylaryl groups, etc., tertiary amines such as triethylamine, dimethylbenzylamine, triphenylamine, secondary amines such as diethylamine, dibutylamine, diphenylamine, butylamine, pentylamine Primary amines such as hexylamine, decylamine and aniline, imidazoles such as 2-methylimidazole, 2-phenylimidazole and benzimidazole, Or, ammonia, tetramethylammonium borohydride, tetrabutylammonium borohydride, tetrabutylammonium tetraphenylborate, basic salts such as tetraphenyl ammonium tetraphenylborate and tetraphenylphosphonium tetraphenylborate is used.

These catalysts are composed of pentacyclopentadecane dimethanol and norbornane dimethanol in total of 1
It is used in a ratio of 10 ^-9 to 10 ^-3 mol, preferably 10 ^-7 to 10 ^-4 mol, per mol. If the amount is less than 10 ^-9 mol, sufficient polymerization activity cannot be obtained, which is not preferable. On the other hand, if it exceeds 10 ^-3 mol, the coloring of the resin becomes remarkable, which is not preferable.

The transesterification according to the present invention can be carried out by a known melt polycondensation method. That is,
Melt polycondensation is carried out using the above-mentioned raw materials and a catalyst while removing by-products by a transesterification reaction under normal pressure or reduced pressure while heating. The reaction is generally carried out in two or more stages.

Specifically, the reaction temperature of the first stage is usually from 120 to 260 ° C., preferably from 180 to 240 ° C., and the reaction time is usually from 0.1 to 5 hours, preferably from 0.1 to 5 hours.
5 to 3 hours. Next, the reaction was carried out by raising the reaction temperature while increasing the degree of vacuum of the reaction system, and finally 1 mmHg
The polycondensation reaction is performed at a temperature of 200 to 300 ° C. under the following reduced pressure. Such a reaction may be performed in a continuous manner or in a batch manner. The reactor used for performing the above reaction was a vertical type equipped with an anchor type stirring blade, a max blend stirring blade, a helical ribbon type stirring blade, etc., but also equipped with paddle blades, lattice wings, glasses wings and the like. Although it may be a horizontal type or an extruder type equipped with a screw, in the case of a continuous type, it is preferable to use a reaction apparatus in which these are appropriately combined.

In the polycarbonate resin according to the present invention, the catalyst is removed or deactivated in order to maintain heat stability and hydrolysis stability after the completion of the polymerization reaction. Generally, a method of deactivating the catalyst by adding a known acidic substance or a derivative thereof is performed. Specific examples of these acidic substances or derivatives thereof include aromatic sulfonic acids such as p-toluenesulfonic acid, aromatic sulfonic acid esters such as butyl p-toluenesulfonic acid and hexyl p-toluenesulfonic acid, and dodecyl. Aromatic sulfonic acid phosphonium salts such as benzenesulfonic acid tetrabutylphosphonium salt, organic halides such as stearic acid chloride, benzoyl chloride, p-toluenesulfonic acid chloride, alkyl sulfates such as dimethyl sulfate, and organic halides such as benzyl chloride. Is preferably used.

After deactivation of the catalyst, a step of devolatilizing and removing low-boiling compounds in the polymer at a pressure of 0.1 to 1 mmHg and a temperature of 200 to 300 ° C. may be provided. A horizontal device equipped with a stirring blade having an excellent surface renewing ability, such as a wing or an eyeglass wing, or a thin film evaporator is preferably used.

Further, in the present invention, the above-mentioned heat stabilizer,
In addition to hydrolysis stabilizers, antioxidants, pigments, dyes, reinforcing agents and fillers, ultraviolet absorbers, lubricants, release agents, nucleating agents,
Plasticizers, flow improvers, antistatic agents, antibacterial agents and the like can be added.

The above additive may be added while the polycarbonate resin obtained by melt polycondensation is in a molten state immediately after the reaction, or may be added again after pelletizing the polycarbonate resin. Further, a plurality of additives may be added at different addition times.

When the additive is added to the molten resin immediately after the reaction, it is added directly to the reaction vessel after the completion of the reaction, followed by stirring and mixing, or it is added to the resin extracted from the reaction vessel to add a horizontal kneader. And uniformly kneaded, and then pelletized as it is. Alternatively, a method is used in which the resin extracted from the reaction vessel is fed into a horizontal kneader, an additive is added by a side feed in the middle of the kneader, uniformly kneaded, and then pelletized as it is.

When additives are added to the pelletized resin, the pellets and the above additives are dispersed and mixed by a high-speed mixer represented by a turnbull mixer, a Henschel mixer, a ribbon blender, a super mixer, and then extruded. A method of melt-kneading with a kneader such as a Banbury mixer or a roll is appropriately selected.

[0027]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

Example 1 49.9 g of pentacyclopentadecane dimethanol
(0.19 mol), 1.6 g of norbornane dimethanol
(0.01 mol), 43.3 g of diphenyl carbonate
(0.202 mol) and sodium bicarbonate 5 × 10 ^-4
g (6 × 10 ^-6 mol) in 3 with a stirrer and a distilling device
Put into a 00 ml four-necked flask and place in a nitrogen atmosphere 760 mm
Heat to 180 ° C. under Hg and stir for 30 minutes. afterwards,
At the same time as adjusting the degree of vacuum to 150 mmHg,
The temperature was raised to 200 ° C. at a rate of hr, and the temperature was maintained at that temperature for 40 minutes to perform a transesterification reaction. 75 ° C
/ Hour at a rate of 225 ° C./hr, and 40 minutes after the completion of the temperature increase, while maintaining the temperature, reduce the degree of decompression to 1 over 1 hour.
mmHg or less. Thereafter, the temperature was raised to 235 ° C. at a rate of 105 ° C./hr and the reaction was carried out with stirring for a total of 6 hours. After the reaction was completed, nitrogen was blown into the reactor to return to normal pressure, and the produced polycarbonate resin was taken out. Table 1 shows the measurement results of the physical properties of the polycarbonate resin.

Example 2 In Example 1, 36.7 g (0.14 mol) of pentacyclopentadecane dimethanol, 9.4 g (0.06 mol) of norbornane dimethanol, and 43.3 g (0.202 mol) of diphenyl carbonate were used. And the same operation as in Example 1 except that 5 × 10 ⁻⁴ g (6 × 10 ⁻⁶ mol) of sodium hydrogencarbonate was used. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

Example 3 In Example 1, 15.7 g (0.06 mol) of pentacyclopentadecane dimethanol, 21.9 g (0.14 mol) of norbornane dimethanol, 43.3 g (0.202 mol) of diphenyl carbonate and The same operation as in Example 1 was performed except that 5 × 10 ⁻⁴ g (6 × 10 ⁻⁶ mol) of sodium hydrogencarbonate was used. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

COMPARATIVE EXAMPLE 1 In Example 1, 31.2 norbornane dimethanol was used.
g (0.2 mol), 43.3 g of diphenyl carbonate
(0.202 mol) and sodium bicarbonate 5 × 10 ^-4
g (6 × 10 ⁻⁶ mol) and the same operation as in Example 1 was performed except that pentacyclopentadecanedimethanol was not used. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

Comparative Example 2 A polycarbonate resin composed of bisphenol A (Iupilon H- manufactured by Mitsubishi Engineering-Plastics Corporation)
4000). Table 1 shows the results.

The physical properties in Table 1 are measured by the following methods. 1) Refractive index (n _D ), Abbe number (ν _D ): Measured with an ATAGO refractometer. 2) a polystyrene equivalent weight average molecular weight (M _W): measured by GPC using chloroform as a developing solvent. 3) Glass transition temperature (T _g ): measured by a differential scanning calorimeter. 4) Thermal decomposition onset temperature (T _d ): 1 in a nitrogen stream with a thermobalance
The temperature at which the% weight loss was measured. Heating rate is 10 ° C / m
in. 5) Photoelastic coefficient: thickness 100 by ellipsometer
μm cast film, laser wavelength 633n
m, and calculated from the measurement of birefringence with respect to the change in load. 6) Q value: Measured with a flow tester at a resin temperature of 240 ° C., a residence time of 6 min, and a cylinder pressure of 160 kgf / cm ² using a die having a height of 10 mm and a hole diameter of 1 mm.

In Table 1, the following abbreviations were used as compound names. PCPDM: Pentacyclopentadecane dimethanol NBDM: Norbornane dimethanol H-4000: Polycarbonate resin composed of bisphenol A

Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 ───── NBDM / PCPDM (molar ratio) 5/95 30/70 70/30 100/0 H-4000 Refractive index (n _D ) 1.537 1.537 1.536 1.535 1.586 Abbe number (ν _D ) 49 49 48 48 30 M _{W 64700 66000 65800 64300 34500 T g} (℃) 133 120 101 83 145 T d (℃) 332 333 332 334 445 photoelastic coefficient ^{(10 -12 m 2 / N)} 12 12 12 13 78 Q value (cm ³ / sec ) 0.11 0.16 0.23 0.32 0.094 ───────────────────────────────────

[0036]

The polycarbonate resin according to the present invention comprises:
A novel aliphatic polycarbonate resin with excellent transparency, heat resistance, impact resistance, good refractive index-Abbe number balance, low photoelastic coefficient, etc., various lenses, prisms, optical fibers, etc. It can be very usefully used as a material for plastic optical products.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H050 AB42Z 4J029 AB01 AC02 AE04 AE05 BD10 HC02 HC04A HC05A HC05B JA091 JA121 JB171 JC031 JC051 JC091 JC261 JC411 JC731 JF021 JF031 JF041 JF05 JF07 J06

Claims (4)

[Claims] 1. A polycarbonate resin comprising the structural units represented by the structural formulas (1), (2) and (3). Embedded image Embedded image Embedded image 2. The method for producing a polycarbonate resin according to claim 1, wherein pentacyclopentadecane dimethanol and norbornane dimethanol and a carbonic acid diester are melt-polycondensed in the presence of a basic compound. 3. A total of 1 mol of pentacyclopentadecane dimethanol and norbornane dimethanol,
The method for producing a polycarbonate resin according to claim 2, wherein 10 ^-9 to 10 ^-3 mol of a basic compound is used as a catalyst. 4. The polycarbonate resin according to claim 1, which is used for an optical material.