JPH11343335A - Production of aromatic/aliphatic copolycarbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a polycarbonate having excellent impact resistance, excellent heat resistance, a high Abbe's number, and a low photoelastic constant by reacting an aromatic dihydroxy compound and an aliphatic dihydroxy compound with a carbonic diester so as to obtain a product having a specified or higher nitrogen content. SOLUTION: An aromatic dihydroxy compound represented by formula I, such as bisphenol A, an aliphatic dihydroxy compound represented by formula II, such as 3,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane and having a nitrogen content of 10 ppm or below, and a carbonic diester such as diphenyl carbonate are subjected to a first-stage reaction at 120-260 deg.C in the presence of an alkali metal catalyst, or the like, and the reaction product is polycondensed at 200-300 deg.C at reduced pressure to obtain a polycarbonate resin having a weight-average molecular weight of 30,000-200,000 and a nitrogen content of 9 ppm or below. In the formulae, X is O, S, or the like; R1 and R2 are each H, a halogen, or the like; R3 and R4 are each H, a 1-10C alkyl, or the like; R5 to R8 are each a 1-10C alkyl or the like; and (m) and (n) are each 0-4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing an aromatic-aliphatic polycarbonate having excellent impact resistance, low photoelastic constant, high refractive index and inverse dispersion value, and excellent transparency and heat resistance. More specifically, the present invention relates to a method for producing an aromatic-aliphatic copolymer polycarbonate having a good color tone.

[0002]

2. Description of the Related Art A polycarbonate resin obtained by interfacially polymerizing an aromatic dihydroxy compound such as bisphenol A and phosgene in the presence of an acid binder has excellent mechanical properties such as impact resistance, heat resistance, and transparency. Because of its excellent properties, it is used as an optical material for various lenses, prisms, optical disk substrates, and the like.

However, polycarbonate using only bisphenol A as an aromatic dihydroxy compound has a large photoelastic constant and relatively low melt fluidity, so that the birefringence of a molded product becomes large and the refractive index is 1. Since the Abbe number is as high as 58 and the Abbe number is as low as 30, there is a drawback that it does not have sufficient performance to be widely used for applications such as optical recording materials and optical lenses.

[0004] In order to solve such disadvantages of bisphenol A-polycarbonate, the present inventors have previously described aromatic-aliphatic copolymerized polycarbonate resin (Japanese Patent Application No. Hei 8-
276260). This aromatic-aliphatic copolymerized polycarbonate resin has excellent impact resistance and heat resistance, and furthermore has a small photoelastic constant and a high Abbe number, so that it can be widely used as an optical material. Such an aromatic-aliphatic copolymerized polycarbonate is difficult to produce by a normal phosgene method, and is a method known as a transesterification method, that is, an aromatic dihydroxy compound, an aliphatic dihydroxy compound and a carbonate such as diphenyl carbonate. A method of performing polycondensation with a diester by a transesterification reaction in a molten state is suitably used.

[0005] In the transesterification reaction, when producing polycarbonate, polycondensation is usually carried out while heating to a temperature of 200 ° C to 330 ° C. However, it is difficult to obtain an excellent product. For this reason, it has been difficult to use the polycarbonate obtained by this method in a field requiring a color tone.

[0006]

SUMMARY OF THE INVENTION The present invention aims to solve the problems associated with the prior art as described above, and provides excellent impact resistance, heat resistance, high Abbe number and low photoelastic constant. It is an object of the present invention to provide an aromatic-aliphatic polycarbonate having excellent color tone and a method for producing the polycarbonate.

[0007]

Means for Solving the Problems The polycarbonate resin of the present invention comprises a structural unit derived from an aromatic dihydroxy compound represented by the following formula (1) and an aliphatic dihydroxy compound represented by the following formula (2). It is characterized by comprising a derived unit and a derived unit derived from carbonic acid diester.

[0008]

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(In the above formula (1), X is

[0010]

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Wherein R ₃ and R ₄ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or a phenyl group, respectively, and R ₃ and R ₄ may combine to form a ring. R ₁ and R ₂ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or halogen, respectively, and R ₁ and R ₂ may be the same or different. Further, m and n represent the number of substituents and are integers of 0 to 4. )

[0012]

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(In the above formula (2), R ₅ , R ₆ , R ₇ and R ₈ are a hydrogen atom or a monovalent alkyl group having 1 to 10 carbon atoms.)

The aliphatic dihydroxy compound represented by the above formula (2) is generally synthesized by an acid catalyzed reaction of hydroxyaldehyde represented by the following reaction formula (3) with pentaerythritol. Generally, mineral acids such as hydrochloric acid, phosphoric acid and nitric acid, and organic acids such as paratoluenesulfonic acid and methanesulfonic acid can be used as the acid catalyst.

[0015]

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(In the above reaction formula (3), R ₅ ,
R ₆ , R ₇ and R ₈ are each a hydrogen atom or a monovalent alkyl group having 1 to 10 carbon atoms. The hydroxyaldehyde represented by the above reaction formula (3) is synthesized by cross-aldol condensation of an aliphatic aldehyde represented by the following reaction formula (4) with formaldehyde, and proceeds in the presence of either an acidic or alkaline catalyst. I do. However, when a mineral acid such as hydrochloric acid, phosphoric acid, sulfuric acid or nitric acid or an organic acid such as paratoluenesulfonic acid or methanesulfonic acid is used, hydroxyaldehyde is dimerized or tetramerized. , Potassium hydroxide, potassium carbonate and the like, and inorganic bases such as triethylamine and pyridine are often used.
Particularly, industrially, triethylamine is preferably used for reasons such as yield and purity.

[0017]

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(In the above reaction formula (4), R5, R6
Is a hydrogen atom or a monovalent alkyl group having 1 to 10 carbon atoms. Further, a hydroxyaldehyde in which the substituents R5 and R6 are replaced with R7 and R8 can also be synthesized in the same manner as in the above reaction formula (4). ) Hydroxyaldehyde is dimerized and tetramerized,
Since the monomer is relatively unstable and is also a reaction intermediate, it is often used industrially in the next synthesis step without going through a purification step. Therefore, the hydroxy aldehyde synthesized using the amine catalyst is used in the next step with the amine catalyst remaining, so that the amine compound remains in the aliphatic dihydroxy compound obtained by the above reaction formula (3). Would. If the amine is not used as a catalyst for the synthesis of dihydroxyaldehyde, or if a method of purifying the dihydroxyaldehyde and then subjecting it to the synthesis of an aliphatic dihydroxy compound is employed, the problem of remaining amine can be avoided.

However, in the case of the above-mentioned commercially available aliphatic dihydroxy compound, since the amine catalyst such as triethylamine is used in the synthesis of the above-mentioned hydroxyaldehyde, the amine compound remains as an impurity in the aliphatic dihydroxy compound. doing. The present inventors have conducted intensive studies to reduce the nitrogen content in commercial products, and as a result, have found a correlation between the color tone of the aromatic-aliphatic copolymerized polycarbonate and the nitrogen content of the aliphatic dihydroxy compound used. The present inventors have found that there is a relationship, and have found that an aromatic-aliphatic copolymer polycarbonate having a nitrogen content of 9 ppm or less has a good color tone, thereby completing the present invention.

That is, the present invention provides a polycondensation of an aromatic dihydroxy compound represented by the above formula (1), an aliphatic dihydroxy compound represented by the above formula (2), and a carbonic acid diester under heating and melting. Aromatic-aliphatic copolymerized polycarbonate having a nitrogen content of 9 ppm or less and an aromatic-fatty acid using an aliphatic dihydroxy compound having a nitrogen content of 10 ppm or less when producing the aromatic-aliphatic copolymerized polycarbonate. 1 is a method for producing an aromatic polycarbonate.

In the present invention, the nitrogen content in the aliphatic dihydroxy compound is measured by a total nitrogen analyzer.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method for producing an aromatic-aliphatic polycarbonate according to the present invention will be specifically described.
The polycarbonate according to the present invention comprises a structural unit derived from an aromatic dihydroxy compound represented by the above formula (1), a structural unit derived from an aliphatic dihydroxy compound represented by the above formula (2), and a diester carbonate Consisting of structural units derived from

As the aromatic dihydroxy compound, bis (4-hydroxyphenyl) methane, 1,1-bis (4
-Hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) octane, bis (4-hydroxy Phenyl) phenylmethane, 2,2-bis (4-hydroxy-
3-methylphenyl) propane, 1,1-bis (4-hydroxy-3-t-butylphenyl) propane, 2,2
-Bis (4-hydroxy-3-bromophenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4′-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethylphenyl ether, 4,4'-dihydroxyphenyl sulfide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, , 4'-dihydroxy-3,3-dimethyldiphenylsulfoxide, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxy-3,
3'-dimethyldiphenyl sulfone or the like is used.

Of these, in particular, 2,2-bis (4-
Hydroxyphenyl) propane, bisphenol A, or 1,1-bis (4-hydroxyphenyl) cyclohexane is preferred.

Examples of the aliphatic dihydroxy compound include 3,
9-bis (2-hydroxyethyl-2,4,8,10-
Tetraoxaspiro (5.5) undecane, 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,
4,8,10-tetraoxaspiro (5.5) undecane, 3,9-bis (2-hydroxy-1,1-diethylethyl) -2,4,8,10-tetraoxaspiro (5.5) Undecane, 3,9-bis (2-hydroxy-1,1-dipropylethyl) -2,4,8,10-tetraoxaspiro (5.5) undecane and the like are used. Preferably, 3,9-bis (2-hydroxy-1,
1-dimethylethyl) -2,4,8,10-tetraoxaspiro (5.5) undecane is used.

The present invention is characterized in that the aliphatic dihydroxy compound used is purified so that the nitrogen content is 10 ppm or less.

The nitrogen content in the aliphatic dihydroxy compound can be measured by various methods, but simply, by measuring nitrogen oxides in the gas component after burning the sample. is there. As a total nitrogen analyzer using a chemiluminescence method, for example, TN-10 manufactured by Mitsubishi Chemical is commercially available, and the nitrogen content of the aliphatic dihydroxy compound was measured using this apparatus.

In order to produce such an aliphatic dihydroxy compound having a nitrogen content equal to or less than a specific value, purification methods such as distillation and recrystallization can be used effectively.
In the present invention, a method of heating and dissolving the aliphatic dihydroxy compound in a solvent and then cooling and recrystallizing the solvent is particularly effective. In this case, it is more effective to include a step of removing nitrogen-containing impurities by adsorption or a step of washing with water. It is a target.

As the recrystallization solvent that can be used in the present invention, it is preferable that the solubility of the aliphatic dihydroxy compound is sufficiently high at a high temperature and sufficiently low at around room temperature. It is further preferable that the nitrogen-containing impurities are removed by the operation. Examples of the solvent having such properties include alcohols, ethers, esters, ketones, and aromatic hydrocarbons.

More specifically, examples of the compound include alcoholic solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol, tert-butanol and 1-butanol.
Pentanol, 2-methyl-1-butanol, isoamyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, caprylic alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, allyl alcohol, crotyl alcohol, propargyl alcohol, Cyclopentanol, cyclohexanol, 2-methoxyethanol, 2
-Ethoxyethanol, 2-butoxyethanol, ethylene glycol, and the like.

Examples of ether solvents include diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether, di-n-amyl ether, diisoamyl ether, methyl butyl ether, methyl-n-amyl ether, methyl isoamyl ether, Ethyl propyl ether, ethyl isopropyl ether, ethyl butyl ether, ethyl isobutyl ether, ethyl-n-amyl ether, ethyl isoamyl ether, diallyl ether, ethyl allyl ether, anisole, phenetole, diphenyl ether,
Examples thereof include dibenzyl ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether.

Examples of the ester solvent include ethyl acetate, isobutyl acetate, n-butyl acetate, isobutyl acetate, n-amyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, and butyl propionate. Isobutyl propionate, n-amyl propionate, isoamyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, n-butyrate
Amyl, isoamyl butyrate, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate, isopropyl isobutyrate, isobutyl isobutyrate, isoamyl isobutyrate, methyl valerate,
Ethyl valerate, propyl valerate, butyl valerate, n-amyl valerate, isoamyl valerate, methyl isovalerate, ethyl isovalerate, propyl isovalerate, isopropyl isovalerate, isobutyl isovalerate, isovaleric acid Isoamyl, methyl benzoate, ethyl benzoate and the like can be mentioned.

Examples of the ketone solvents include acetone, methyl ethyl ketone, isopropyl methyl ketone, butyl methyl ketone, isobutyl methyl ketone, pinacolone, diethyl ketone, butyrone, diisopropyl ketone, methyl vinyl ketone, mesityl oxide, methyl heptenone,
Cyclobutanone, cyclohexanone and the like can be mentioned.

Examples of the aromatic hydrocarbon compound include benzene, toluene, xylene, mesitylene and the like.

Of these, particularly preferred recrystallization solvents are alcohols, and more preferred are alcohols having 1 to 10 carbon atoms. Further, two or more of the above solvents may be used as a mixture.

In the case where the recrystallization operation includes a step of washing the recrystallization solvent in which the aliphatic dihydroxy compound is dissolved with water while heating, the organic solvent which is separated from water in the recrystallization solvent may be used. It is necessary to select a solvent.
From organic solvents such as alcohols, ethers, esters, ketones, and aromatic hydrocarbons, an organic solvent that can be separated from water may be selected. Particularly preferred organic solvents include C4 to C4.
C10 alcohol.

More specifically, n-butyl alcohol, i-butyl alcohol, s
ec-butyl alcohol, tert-butyl alcohol
, N-amyl alcohol, 2-pentyl alcohol,
3-pentyl alcohol, i-amyl alcohol, 2-
Methyl-1-butanol, 3-methyl-2-butano-
, Neopentyl alcohol, tert-pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, caprylic alcohol, nonyl alcohol, decyl alcohol, cyclopentanol, cyclohexanol. And the like. Among these solvents, a particularly preferred solvent is n-butyl alcohol-
I-butyl alcohol, n-amyl alcohol, i
-Amyl alcohol.

Recrystallization can be carried out by a known method, and recrystallization may be carried out two or more times depending on the purity of the raw material and the like. The crystals obtained by recrystallization are filtered, washed, dried by an appropriate method, and used as a resin raw material.

By including a step of contacting with an adsorbent during the recrystallization step, nitrogen-containing impurities can be further reduced. That is, the aliphatic dihydroxy compound is dissolved in a solvent and then brought into contact with the adsorbent. As a method,
The method is suitably carried out by either a batch method in which an adsorbent is added to a solution and stirring is performed, or a flow method in which the solution is passed through an adsorbent layer packed in a column.

As the adsorbent, activated carbon, alumina, silica, zeolite and the like are preferably used, and activated carbon is particularly preferred.

After the adsorbent is completely removed from the solution subjected to the adsorption treatment by a method such as filtration, crystals of the aliphatic dihydroxy compound are obtained by the above-mentioned ordinary recrystallization.

The nitrogen content can be further reduced by including a step of washing the recrystallization solvent in which the aliphatic dihydroxy compound has been dissolved with water while heating during the recrystallization step. This method is suitably carried out in either a batch system or a continuous system such as a combination of a mixer and a settler.

After dissolving the aliphatic dihydroxy compound in an organic solvent by heating, it may be washed by contacting with water under heating, or the aliphatic dihydroxy compound, the organic solvent,
After mixing the water, it may be heated to a predetermined temperature to dissolve and wash.

As the number of washings with water increases, the nitrogen content in the aliphatic dihydroxy compound decreases. However, economically, the number of washings with water is preferably smaller.

It is also effective to wash the recrystallization solvent in which the aliphatic dihydroxy compound is dissolved with an aqueous solution containing a pH adjuster, a reducing agent and an oxidizing agent.

The basic compound used for washing with an alkaline aqueous solution includes lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, and 4-borane. Lithium oxide, sodium borate, 4
Potassium borate, ammonia and the like. Among these, preferred basic compounds include potassium carbonate and potassium hydrogen carbonate.

The acidic compound used for washing with an acidic aqueous solution includes hydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid,
Examples include nitric acid, phosphoric acid, boric acid, p-toluenesulfonic acid, methanesulfonic acid and the like. Among these, boric acid is preferably used as the acidic compound.

As the reducing substance, sodium hydrosulfite, sodium sulfite, potassium sulfite, lithium bisulfite, sodium bisulfite, potassium bisulfite, lithium nitrite, sodium nitrite, potassium nitrite, lithium thiosulfate, sodium thiosulfate , Potassium thiosulfate and the like, and a preferred reducing substance is sodium hydrosulfite. The pH to be treated with sodium hydrosulfite may be acidic or alkaline, but alkaline is more effective, and lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, potassium carbonate, and sodium hydrogen carbonate are used. It is preferably used in combination with a basic compound such as potassium bicarbonate, lithium lithium borate, sodium tetraborate, potassium borate, ammonia and the like.
Suitable examples of the basic compound used in combination include lithium hydroxide, sodium hydroxide, and potassium hydroxide.

Examples of the oxidizing substance include hydrogen peroxide, sodium percarbonate, potassium percarbonate, sodium perborate, potassium perborate, sodium hypochlorite, potassium hypochlorite, sodium chlorite, and chlorite. Potassium acid, sodium chlorate, potassium chlorate, lithium chlorate, sodium perchlorate, potassium perchlorate, lithium perchlorate, sodium permanganate, potassium permanganate,
Oxidizing substances such as sodium manganate, potassium manganate, sodium persulfate, potassium persulfate, potassium dichromate, and potassium chromate can be used.
Among these oxidizing substances, hydrogen peroxide is preferred.
When hydrogen peroxide is used, it may be neutral, but lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium borate, It is used in combination with basic compounds such as sodium 4-borate, potassium borate, and ammonia, or hydrofluoric acid, hydrochloric acid, hydrobromic acid,
It is preferable to use together with an acidic compound such as sulfuric acid, nitric acid, phosphoric acid, boric acid, p-toluenesulfonic acid and methanesulfonic acid. Particularly preferred pH adjusters include boric acid.

After the organic solvent containing the aliphatic dihydroxy compound is washed with the aqueous solution containing these pH adjusting agent, reducing agent and oxidizing agent, the remaining of the added pH adjusting agent, reducing agent and oxidizing agent becomes a problem. Therefore, it is necessary to wash with water at least once. Therefore, the preferred range of the number of washings with the aqueous solution is 1 to 10 times, more preferably 2 to 5 times.

The polycarbonate resin according to the present invention comprises:
It is composed of a structural unit derived from the aromatic dihydroxy compound represented by the above formula (1) and a structural unit derived from the aliphatic dihydroxy compound represented by the above formula (2). A polymer or a polycarbonate comprising a structural unit derived from an aromatic dihydroxy compound represented by the above formula (1);
Because it contains a blend of polycarbonate consisting of structural units derived from an aliphatic dihydroxy compound represented by, for example, excellent heat resistance, and hue, further exhibit a well-balanced refractive index and dispersion properties, the birefringence is Shows the characteristic of being low.

In the present invention, a structural unit derived from such an aromatic dihydroxy compound (hereinafter referred to as (I)
Called. ) And a structural unit derived from an aliphatic dihydroxy compound (hereinafter, referred to as (II)) preferably have a molar ratio (I) / (II) of 90/10 to 10/90, and more preferably. 80 / 20-20 / 8
0 is preferred. That is, the molar ratio (I) / (II) of the structural unit derived from the aromatic dihydroxy compound and the aliphatic dihydroxy compound in the polycarbonate is 10 /.
If it is lower than 90, the heat resistance will be poor, and if it is higher than 90/10, the photoelastic constant, water absorption, etc. will increase, and the balance between the refractive index and the Abbe number will worsen, which is not preferable as an optical material.

In the present invention, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, etc. are used as the carbonic acid diester. . Among these, diphenyl carbonate is particularly preferred. Diphenyl carbonate is used in an amount of 0.97 to 0.9 mol based on a total of 1 mol of the aromatic dihydroxy compound and the aliphatic dihydroxy compound.
It is preferably used in an amount of 1.2 mol, particularly preferably 0.99 to 1.10 mol.

The weight average molecular weight of the polycarbonate resin used in the present invention is preferably from 30,000 to 200,000, more preferably from 50,000 to 1
20,000.

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

Examples of such compounds include organic acids such as alkali metals and alkaline earth compounds, inorganic salts, oxides, hydroxides, hydrides or alkoxides, quaternary ammonium hydroxides and salts thereof, amines and the like. Are preferably used, and these compounds can be used alone or in combination.

As such an 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, potassium acetate, cesium acetate,
Lithium acetate, sodium stearate, potassium stearate, cesium stearate, lithium stearate, sodium borohydride, sodium borohydride, sodium benzoate, potassium benzoate, cesium benzoate, lithium benzoate, disodium hydrogen phosphate , Dipotassium hydrogen phosphate, dilithium hydrogen phosphate, disodium phenylphosphate, disodium salt of bisphenol A, 2 potassium salt, 2 cesium salt, 2 lithium salt, phenol sodium salt, potassium salt, cesium salt, lithium Salts and the like are used.

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 acetate, calcium acetate, strontium acetate, barium acetate, magnesium stearate, calcium stearate, calcium benzoate, phenyl phosphate Magnesium or the like is used.

Specific examples of the nitrogen-containing compound include alkyl, aryl, tetraalkylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide and trimethylbenzylammonium hydroxide. Ammonium hydroxides having an araryl group and the like, tertiary amines such as triethylamine, dimethylbenzylamine and triphenylamine, secondary amines such as diethylamine and dibutylamine, primary amines such as propylamine and butylamine,
Imidazoles such as 2-methylimidazole and 2-phenylimidazole, or basic salts such as ammonia, tetramethylammonium borohydride, tetrabutylammonium tetraphenylborate, and tetraphenylammonium tetraphenylborate are used.

These catalysts are used in an amount of 10 ^-9 to 10 ^-3 mol, preferably 10 ^-7 to 1 ^-1 mol, per mol of the aromatic dihydroxy compound and the aliphatic dihydroxy compound in total.
Used in an amount of 0 ^-5 mol.

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 transesterification under heating or normal pressure or reduced pressure. The reaction is generally carried out in two or more stages.

Specifically, the first-stage reaction is performed at 120 to 2
The reaction is carried out at a temperature of 60 ° C, preferably 180 to 240 ° C, for 0 to 5 hours, preferably 0.5 to 3 hours. Next, the reaction temperature is increased while increasing the degree of vacuum of the reaction system, and the reaction of the aromatic dihydroxy compound, the aliphatic dihydroxy compound and the carbonic acid diester is carried out. Finally, the reaction is carried out under a reduced pressure of 1 mmHg or less at a temperature of 200 to 300 ° C. Perform a condensation reaction. Such a reaction may be carried out continuously or batchwise. The reaction apparatus used for performing the above reaction may be a tank type or an extruder type.

In order to maintain heat stability and hydrolysis stability, it is preferable to remove or deactivate the catalyst in the polycarbonate, which is a product at the end of the polymerization according to the present invention. The method of deactivating a transesterification catalyst such as an alkali metal or an alkaline earth metal by the above method is preferably carried out. As these substances, specifically, aromatic sulfonic acids such as p-toluenesulfonic acid, butyl p-toluenesulfonate, aromatic sulfonic acid esters such as hexyl p-toluenesulfonic acid,
Organic halides such as stearic acid chloride, butyric acid chloride, benzoyl chloride, p-toluenesulfonic acid chloride, alkyl sulfates such as dimethyl sulfate, organic halides such as benzyl chloride, and inorganic acids such as boric acid and phosphoric acid are preferable. Used for

After deactivation of the catalyst, a step of degassing and removing low-boiling compounds in the polymer at a pressure of 0.1 to 1 mmHg and at a temperature of 200 to 300 ° C. may be provided. A horizontal apparatus equipped with a stirring blade having excellent surface renewability, such as a wing or an eyeglass wing, or a thin film evaporator is suitably 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, crystal nucleating agents, plasticizers, flow improvers, antistatic agents, etc. Can be added.

Each of these additives can be mixed with the polycarbonate resin by a conventionally known method. For example, a method in which each component is dispersed and mixed by a high-speed mixer represented by a turnbull mixer, a Henschel mixer, a ribbon blender, or a super mixer, and then melt-kneaded by an extruder, a Banbury mixer, a roll, or the like is appropriately selected.

[0067]

The polycarbonate resin of the present invention has improved refractive index, dispersion balance and photoelastic constant while maintaining the excellent properties of polycarbonate such as impact resistance and heat resistance. , Prisms, optical disc substrates, and other plastic optical materials.

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to the following Examples.

[0069]

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 Commercially available 3,3'-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro (5.5) undecane (hereinafter referred to as spiroglycol)
800 g was completely dissolved in 10 liters of methanol at a temperature of 60 ° C., and then cooled to room temperature to recrystallize spiroglycol. The crystals were separated by filtration, rinsed with approximately the same volume of methanol as the crystals, and then dried at 60 ° C. in a vacuum drier to obtain 560 g of crystals. The nitrogen content of this crystal is 8.5 pp
m.

2,2-bis (4-hydroxyphenyl)
22.8 g (0.10 mol) of propane, 30.4 g (0.10 mol) of the purified spiroglycol obtained above, 43.3 g (0.202 mol) of diphenyl carbonate, 6.0 × 10 −7 sodium bicarbonate The mol was placed in a 300 cc four-necked flask equipped with a stirrer and a distilling apparatus, heated to 180 ° C. under a nitrogen atmosphere, and stirred for 30 minutes.

Thereafter, the degree of reduced pressure was adjusted to 150 mmHg, and at the same time, the temperature was raised to 200 ° C. at a rate of 60 ° C./hr to carry out a transesterification reaction. Further, the temperature was raised to 260 ° C. while distilling off phenol, and the temperature was maintained at that temperature for 10 minutes, and the degree of reduced pressure was reduced to 1 mmHg or less over 1 hour. 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 was taken out. Table 1 shows the physical properties of this polycarbonate.

Example 2 As a solvent for recrystallizing spiroglycol, isobutanol was used instead of methanol, and spiroglycol 800
g was completely dissolved in 10 liters of isobutanol at 90 ° C., and then cooled to room temperature for recrystallization. After the crystals were separated by filtration, the crystals were washed with approximately the same volume of isobutanol as the crystals and dried in vacuo at 80 ° C.
0 g was obtained. The nitrogen content of the obtained spiroglycol was 9.1 ppm. Except that this purified spiro glycol was used, the same operation as in Example 1 was performed to obtain a bisphenol A-spiro glycol copolymerized polycarbonate. Table 1 shows the physical properties of the obtained polycarbonate.

Example 3 As a recrystallization solvent for spiroglycol, 2-ethoxyethanol was used in place of methanol, and 800 g of spiroglycol was completely dissolved in 10 liters of 2-ethoxyethanol at 90 ° C., followed by cooling to room temperature. Recrystallization was performed. After the crystals were separated by filtration, the crystals were washed with 2-ethoxyethanol having almost the same volume as the crystals, and dried at 80 ° C. under vacuum to obtain 720 g of spiroglycol crystals. The nitrogen content of the obtained spiroglycol was 6.8 ppm. Except that this purified spiro glycol was used, the same operation as in Example 1 was performed to obtain a bisphenol A-spiro glycol copolymerized polycarbonate. Table 1 shows the physical properties of the obtained polycarbonate.

Example 4 800 g of spiroglycol was added to 2-ethoxyethanol 1
A solution completely dissolved in 0 liter at 90 ° C.
After passing through a commercially available activated carbon cartridge filter (TCC-W1 manufactured by Advantech Toyo Co., Ltd.), the mixture was cooled to room temperature to recrystallize spiroglycol. After filtering off the crystals, the cake was rinsed with approximately the same volume of 2-ethoxyethanol, and dried at 80 ° C. with a vacuum drier to obtain 720 g of crystals. The resulting spiroglycol has a nitrogen content of 2.6.
ppm. Except that this purified spiro glycol was used, the same operation as in Example 1 was performed to obtain a bisphenol A-spiro glycol copolymerized polycarbonate.
Table 1 shows the physical properties of the obtained polycarbonate.

Example 5 875 g of commercially available spiroglycol were mixed with 10 liters of i-butyl alcohol and 8.75 kg of water and boric acid.
Dissolve completely in 6 g at 75 ° C. with stirring,
After stirring at 1 ° C. for 1 hour, the stirring was stopped, and after separating into two layers, 6.78 kg of an aqueous layer was extracted. Further, 3.75 kg of water at 75 ° C. and 0.1 g of potassium carbonate were added, and 1
After stirring for 5 minutes, the stirring was stopped and after separating into two layers, 4.03 kg of the aqueous layer was extracted. 3.75 kg of water at 75 ° C
After stirring for 15 minutes, the stirring was stopped, and the mixture was separated into two layers. Then, 4.12 kg of an aqueous layer was extracted. 3.75 kg of water at 75 ° C. was added again, and the mixture was stirred for 15 minutes. Then, the stirring was stopped and the mixture was separated into two layers, and 4.13 kg of an aqueous layer was extracted. Further, 3.75 kg of water at 75 ° C. was added, and the mixture was stirred for 15 minutes. Then, the stirring was stopped, and the mixture was separated into two layers.
19 kg was extracted. The remaining organic layer was filtered using a 5C filter paper, and then cooled to room temperature to recrystallize spiroglycol. The crystals and the solution were separated using a Nutsche, and the crystals were rinsed with 1 liter of i-butyl alcohol, and then vacuum-dried in a vacuum drier at 60 ° C. to obtain 688 g of purified spiroglycol. The nitrogen content of the obtained spiroglycol was 3.1 ppm. Except that this purified spiro glycol was used, the same operation as in Example 1 was performed to obtain a bisphenol A-spiro glycol copolymerized polycarbonate. Table 1 shows the physical properties of the obtained polycarbonate.

Example 6 875 g of commercially available spiroglycol are completely dissolved in 10 l of i-butyl alcohol and 8.75 kg of water, 4.43 g of sodium hydrosulfite and 4.40 g of potassium hydroxide at 75 ° C. with stirring. After further stirring at 75 ° C. for 1 hour, the stirring was stopped, and after separating into two layers, 6.78 kg of an aqueous layer was extracted. In addition, 75
After adding 3.75 kg of water at ℃ and stirring for 15 minutes, stirring was stopped, and after separating into two layers, 4.22 kg of an aqueous layer was extracted. After adding 3.75 kg of water at 75 ° C. and stirring for 15 minutes, the stirring was stopped, and the mixture was separated into two layers.
g was extracted. 3.75 kg of water at 75 ° C is added again,
After stirring for 15 minutes, stop stirring and separate into two layers,
4.09 kg of the aqueous layer was extracted. The remaining organic layer was filtered using a 5C filter paper, and then cooled to room temperature to recrystallize spiroglycol. The crystals and the solution were separated using a Nutsche, and the crystals were rinsed with 1 liter of i-butyl alcohol, and then vacuum-dried in a vacuum drier at 60 ° C. to obtain 688 g of purified spiroglycol. The nitrogen content of the obtained spiroglycol was 2.9 ppm. Except that this purified spiro glycol was used, the same operation as in Example 1 was performed to obtain a bisphenol A-spiro glycol copolymerized polycarbonate. Table 1 shows the physical properties of the obtained polycarbonate.

Comparative Example 1 The procedure of Example 1 was repeated, except that commercially available spiroglycol was used without purification. The spiro glycol had a nitrogen content of 43.5 ppm. The obtained polycarbonate had a very poor color tone.

COMPARATIVE EXAMPLE 2 Using 2-ethoxyethyl acetate instead of methanol as a recrystallization solvent for spiroglycol, 800 g of spiroglycol was completely dissolved in 10 liters of 2-ethoxyethylacetate at 90 ° C. and then cooled to room temperature. It was cooled and recrystallized. After filtering off the crystals, 2
-The crystals were washed with ethoxyethyl acetate and dried under vacuum at 80 ° C to obtain 700 g of spiroglycol crystals.
The resulting spiroglycol has a nitrogen content of 18.2 pp
m. Other than using this purified spiro glycol,
The same operation as in Example 1 was performed, and bisphenol A-
Spiro glycol copolymerized polycarbonate was obtained. Table 1 shows the physical properties of the obtained polycarbonate, which was colored pale yellow.

Comparative Example 3 As a recrystallization solvent for spiroglycol, diacetone alcohol was used in place of methanol, and 800 g of spiroglycol was completely dissolved in 10 liters of diacetone alcohol at 90 ° C., then cooled to room temperature and recrystallized. Was done.
After the crystals were separated by filtration, the crystals were washed with diacetone alcohol having substantially the same volume as the crystals, and dried at 80 ° C. under vacuum to obtain 700 g of spiroglycol crystals. The nitrogen content of the obtained spiroglycol was 23.1 ppm. Except that this purified spiro glycol was used, the same operation as in Example 1 was performed to obtain a bisphenol A-spiro glycol copolymerized polycarbonate. The physical properties of the obtained polycarbonate are shown in Table 1, and were colored yellow.

The physical properties in Table 1 are measured by the following methods.

(1) Nitrogen content of raw material: Measured using a total nitrogen analyzer (TN-10, manufactured by Mitsubishi Chemical Corporation). The detection limit was 1.5 ppm. (2) Molecular weight: GPC (Shodex GPC sys
It was measured as a styrene-equivalent molecular weight (weight average molecular weight: Mw) using item 11). Chloroform was used as a developing solvent.

(3) Resin YI: The obtained resin is 40 mm
It was press-molded into a φ, 3 mm thick disk, and the YI value (yellowness) was measured with a color difference meter (Tokyo Denshoku TC-1800MK2).

FIG. 1 shows the correlation between the nitrogen content of the starting spiroglycol and the YI of the obtained polycarbonate resin, and FIG. 2 shows the correlation between the nitrogen content of the polycarbonate resin and the YI value.

[0085]

[Table 1]

 ──────────────────────────────────────────────────の Continued on front page (72) Inventor Takashi Konishi 22nd Wadai, Tsukuba, Ibaraki Pref.

Claims (11)

[Claims] An aromatic compound having a nitrogen content of 9 ppm or less.
Aliphatic copolymer polycarbonate 2. The aromatic-aliphatic copolymer according to claim 1, wherein the aromatic-aliphatic copolymer polycarbonate is produced by a reaction of an aromatic dihydroxy compound, an aliphatic dihydroxy compound and a carbonic acid diester by a transesterification method. Copolycarbonate 3. The method of claim 1, wherein the aliphatic dihydroxy compound is 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,
The aromatic-aliphatic copolymeric polycarbonate according to claim 2, which is 4,8,10-tetraoxaspiro (5.5) undecane. 4. An aromatic dihydroxy compound represented by the following formula (1), an aliphatic dihydroxy compound represented by the following formula (2), and a carbonic acid diester are subjected to polycondensation under heating and melting to obtain an aromatic compound. A method for producing an aliphatic-copolycarbonate having a nitrogen content of 9 ppm or less, which comprises using an aliphatic dihydroxy compound having a nitrogen content of 10 ppm or less. Embedded image (In the above formula (1), X is Wherein R3 and R4 are a hydrogen atom or a carbon atom
And R3 and R4 may combine to form a ring. R1 and R2 are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms or halogen;
And R2 may be the same or different. Also, m and n
Represents the number of substituents and is an integer of 0 to 4. ) (In the above formula (2), R5, R6, R7 and R8 are a hydrogen atom or a monovalent alkyl group having 1 to 10 carbon atoms.) 5. The method of claim 1, wherein the aliphatic dihydroxy compound is 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,
The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 4, which is 4,8,10-tetraoxaspiro (5.5) undecane. 6. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 4, wherein the aliphatic dihydroxy compound having a nitrogen content of 10 ppm or less is obtained by a recrystallization method. 7. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 6, wherein the solvent used for recrystallization is an alcohol having 1 to 10 carbon atoms. 8. The method for producing an aromatic-aliphatic copolymerized polycarbonate according to claim 6, which comprises a step of bringing into contact with an adsorbent during the recrystallization operation. 9. The method for producing an aromatic-aliphatic copolymer polycarbonate according to claim 8, wherein the adsorbent is activated carbon. 10. The process for producing an aromatic-aliphatic copolymer polycarbonate according to claim 6, comprising a step of washing the recrystallization solvent in which the aliphatic dihydroxy compound is dissolved during the recrystallization operation with water while heating. 11. The method for producing an aromatic-aliphatic copolymeric polycarbonate according to claim 10, wherein the recrystallized organic solvent is an organic solvent which separates with water.