JP2001011169A - Polycarbonate resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polycarbonate resin that has a low photoelastic coefficient and shows a good balance between the refractive index and the Abbe's number by subjecting pentacyclopentadecane dimethanol and cyclohexane-1,4-dimethanol to melt polycondensation reaction with a carbonic diester. SOLUTION: The objective polycarbonate resin comprises three constitutent units of formula I, formula II and formula III. In a preferred embodiment, (A) pentacyclo-pentadecane dimethanol and (B) cyclohexane-1,4-dimethanol are subjected to melt polycondensation reaction with (C) a carbonic diester (for example, diphenyl carbonate) in the presence of (D) a basic compound (sodium hydroxide) to give the objective polycarbonate resin. The content of the component B is preferably 5-70 mol.% based on the total amount of the components A and B. The amounts of the components C and D are preferably 0.97-1.10 moles and 10-1-10-3 moles per mole of the total of the components A and B, respectively.

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 photoelastic coefficient, a good balance between the refractive index and the Abbe number, and a method for producing the same. This polycarbonate resin is
It can be suitably used as a material for plastic optical products such as 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. However, this method causes a decrease in heat resistance and a decrease in photoelastic coefficient. No sufficient effect has been obtained in reducing the amount.

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 a thermosetting resin. There are problems such as poor productivity, and these solutions are 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, cyclohexane-1,4-dimethanol, and carbonic acid diester.

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

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Cyclohexane-1,4-dimethanol is represented by the following chemical formula (6) and includes isomers.

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The polycarbonate resin according to the present invention contains structural units derived from pentacyclopentadecane dimethanol and cyclohexane-1,4-dimethanol, and the content of cyclohexane-1,4-dimethanol is: , Cyclohexane-1,4-dimethanol and pentacyclopentadecane dimethanol. If the content of cyclohexane-1,4-dimethanol is less than 5 mol%, it is not preferable from the viewpoint of fluidity during molding, 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 cyclohexane-1,4-
It is preferably used at a ratio of 0.97 to 1.10 mol, more preferably 0.99 to 1 mol of the total of dimethanol and pentacyclopentadecane dimethanol.
１．０1.04 mol.

The polycarbonate resin according to the present invention has a weight average molecular weight in terms of polystyrene of 20,000 to 20.
It is preferably 0.000, 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 polycarbonate according to the present invention, a basic compound is used as a catalyst. Such basic compounds include alkali metal compounds,
Examples thereof include alkaline earth metal compounds, nitrogen-containing compounds, and phosphorus-containing compounds.

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 used in a proportion of 10 ^-9 to 10 ^-3 mol, based on 1 mol of cyclohexane-1,4-dimethanol and pentacyclopentadecane dimethanol in total.
Preferably, it is used in a ratio of 10 ^-7 to 10 ^-4 mol. 1
0 ^-9 of less than moles is not preferable because a sufficient polymerization activity can not be obtained. 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), 1.4 g (0.01 mol) of cyclohexane-1,4-dimethanol, 43.3 g (0.202 mol) of diphenyl carbonate and 5 × 10 ⁻⁴ g of sodium hydrogencarbonate (6 × 10 ^-6 mol) was placed in a 300 ml four-necked flask equipped with a stirrer and a distilling apparatus, heated to 180 ° C. under a nitrogen atmosphere of 760 mmHg, and stirred for 30 minutes. Thereafter, the degree of decompression was adjusted to 150 mmHg, and at the same time, the temperature was raised to 200 ° C. at a rate of 60 ° C./hr.
The transesterification reaction was performed while maintaining the temperature for 0 minutes. Further, the temperature was raised to 225 ° C. at a rate of 75 ° C./hr, and 40 minutes after the completion of the temperature raising, the pressure was reduced to 1 mmHg or less over 1 hour while maintaining the temperature. Thereafter, 105 ° C /
The temperature was raised to 235 ° C. at a rate of hr and the reaction was carried out under 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 was added.
Except for using 8.7 g (0.06 mol) of 1,4-dimethanol, 43.3 g (0.202 mol) of diphenyl carbonate and 5 × 10 ⁻⁴ g (6 × 10 ⁻⁶ mol) of sodium hydrogen carbonate. The same operation as in Example 1 was performed. 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 pentacyclopentadecanedimethanol and cyclohexane-
Except for using 20.2 g (0.14 mol) of 1,4-dimethanol, 43.3 g (0.202 mol) of diphenyl carbonate and 5 × 10 ⁻⁴ g (6 × 10 ⁻⁶ mol) of sodium hydrogencarbonate, The same operation as in Example 1 was performed. Table 1 shows the measurement results of physical properties of the obtained polycarbonate resin.

Comparative Example 1 In Example 1, 28.8 g (0.2 mol) of cyclohexane-1,4-dimethanol, 43.3 g (0.202 mol) of diphenyl carbonate and 5 × 10 ⁻⁴ g of sodium hydrogen carbonate were used. (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 CHDM: cyclohexane-1,4-dimethanol H-4000: polycarbonate resin composed of bisphenol A

Table 1 Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 ───── CHDM / 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 65200 65700 67000 66100 34500 T g} (℃) 132 118 98 77 145 T d (℃) 334 333 333 332 445 photoelastic coefficient ^{(10 -12 m 2 / N)} 12 12 13 15 78 Q value (cm ³ / sec ) 0.11 0.17 0.27 0.40 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 AA09 AB01 AC02 AD01 AE04 BD07A BD10 HC04A HC05A HC05B JA091 JA121 JA261 JB171 JC021 JC091 JF021 JF031 JF041 JF131 JF141 JF161 KE02 5D029K07 KA07

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 polycarbonate resin according to claim 1, wherein pentacyclopentadecane dimethanol and cyclohexane-1,4-dimethanol and a carbonic acid diester are melt-polycondensed in the presence of a basic compound. Production method. 3. The polycarbonate according to claim 2, wherein a basic compound is used as a catalyst in an amount of 10 ^-9 to 10 ^-3 mol per 1 mol of pentacyclopentadecane dimethanol and cyclohexane-1,4-dimethanol in total. Method of manufacturing resin. 4. The polycarbonate resin according to claim 1, which is used for an optical material.