JP3390621B2 - Aromatic polycarbonate resin and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aromatic polycarbonate resin having excellent hue and heat aging resistance, and a method for producing the same. More specifically, the present invention relates to an aromatic polycarbonate resin having a good hue, having little deterioration in hue in a heat aging test system, and having an extremely small decrease in molecular weight and having excellent heat aging resistance, and a method for producing the same.

[0002]

2. Description of the Related Art Polycarbonate has excellent mechanical properties such as transparency, heat resistance and impact resistance,
It is a general-purpose engineering plastic with characteristics such as use as a transparent sheet instead of glass.

Known methods for producing polycarbonates include a method of directly reacting a dihydroxy compound and phosgene, and a melting method of transesterifying a dihydroxy compound with a carbonic acid diester under reduced pressure with heating.
Of these, the latter melting method is environmentally preferable because it has an advantage that a polycarbonate resin can be produced at a lower cost than the former interfacial method and does not use a solvent such as methylene chloride.

In the conventional method for producing a polycarbonate by the melting method, an alkali metal compound, an alkaline earth metal compound or the like is usually used as a catalyst component. Generally, the terminal of the polycarbonate obtained by using the above catalyst has a relatively large amount of a phenolic residue derived from an aromatic dihydroxy compound, so that the obtained polycarbonate has a problem that the heat-aged molecular weight is lowered or it is easily colored. It was

There is a method of increasing the proportion of carbonic acid diester used for reducing the phenolic residue relative to the dihydroxy compound, but this method requires an extremely long time for the polymerization reaction, so that the resulting polymer yellows. There was a problem that it was easy to do.

JP-A-2-175723 discloses that a hydroxyl group terminal of a polycarbonate obtained by melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in the presence of a specific catalyst is sealed with a specific compound to obtain heat resistance. Etc., a method for producing an excellent polycarbonate is described.
However, even in the above method, the resulting polymer easily yellows because the end-capping reaction takes an extremely long time,
Further, there is a problem in that it is not preferable in terms of productivity.

JP-A-8-020639 discloses that an aromatic dihydroxy compound and a carbonic acid diester are melt-polymerized in the presence of a specific catalyst and boric acid (ester), whereby the terminal hydroxyl group concentration is low and the heat stability is excellent. A method for producing a polycarbonate is described. However, even in the above method, the polymerization reaction takes an extremely long time, which is not preferable from the viewpoint of productivity. In addition, since a relatively large amount of boric acid (ester), which is a Lewis acid, is added, the obtained polymer has poor hydrolysis resistance and is not necessarily preferable for applications such as optical disks.

The evaluation method described in the publication (160 ° C. ×
30 days) is significantly higher than the temperature at which normal polycarbonate is used, and is not necessarily appropriate as a heat resistance and evaluation method for polycarbonate resins. Further, at the described evaluation temperature (160 ° C.), the polymer is significantly softened, so that there is a problem that the hue after the heat treatment cannot always be accurately measured.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polycarbonate resin excellent in hue and heat aging resistance, and an efficient method for producing the same. More specifically, it is an object of the present invention to provide an aromatic polycarbonate resin having a good hue, having little hue deterioration after a heat aging test, and having an extremely small decrease in molecular weight and having excellent heat aging resistance, and a method for producing the same. Further objects and advantages of the present invention will be apparent from the following description.

[0010]

The present invention is characterized in that an aromatic polycarbonate resin excellent in hue and heat aging resistance is obtained by adding a specific compound to polycarbonate without capping the ends.

That is, the present invention is an aromatic polycarbonate resin obtained by a melt polycondensation method from an aromatic dihydroxy compound and a carbonic acid diester, and a 2 mm thick molded plate of the resin is heat-treated in air at 150 ° C. for 10 days. The subsequent intrinsic viscosity decrease rate is 5% or less, and the color difference (ΔE) is 1
It is an aromatic polycarbonate resin characterized by being 0 or less.

In the present invention, an aromatic dihydroxy compound and a carbonic acid diester are used as a polycondensation catalyst in an amount of 1 × 10 ⁻⁷ to 1 × 10 ^{7 with} respect to 1 mol of the aromatic dihydroxy compound (a).
^-5 mol of the alkali metal compound and / or (b) 1 mol of the aromatic dihydroxy compound, 1 x 10 ^-5 to 1 x
After melt polycondensation in the presence of 10 ⁻³ mol of a nitrogen-containing basic compound, and then the intrinsic viscosity [η] measured at 20 ° C. in methylene chloride reaches at least 0.1, (i) a polycarbonate is formed. The following formula (I) in the proportion of 1 to 200 ppm

[0013]

[Chemical 4]

The phosphorus compound represented by: and (ii) a phenolic compound represented by the following formula (II) -a or (II) -b in a proportion of 50 to 2000 ppm with respect to the produced polycarbonate.

[0015]

[Chemical 5]

And / or (iii) the following formula (II) in a proportion of 50 to 2000 ppm relative to the polycarbonate produced.
I) -a or (III) -b represented by sulfur compounds

[0017]

[Chemical 6]

In the method for producing an aromatic polycarbonate resin described above, a polycarbonate having a desired intrinsic viscosity is produced by adding

The aromatic dihydroxy compound used in the present invention is a compound represented by the following formula (A).

[0020]

[Chemical 7]

In the above formula (A), R ¹ and R ² are the same or different and each represents a hydrogen atom, a halogen atom or a carbon number of 1 to 1.
2 hydrocarbon groups. As the hydrocarbon group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms such as an alkyl group or an aromatic hydrocarbon group having 6 to 12 carbon atoms such as a phenyl group is preferable. Examples of the halogen atom include chlorine, bromine and iodine.

R ⁵ is an alkylene group having 3 to 8 carbon atoms. Examples of the alkylene group include a pentylene group and the like.

In the formula, R ³ and R ⁴ are the same or different and each is a halogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms. Examples of the hydrocarbon group include an aliphatic hydrocarbon group having 1 to 12 carbon atoms such as an alkyl group and an aromatic hydrocarbon group having 6 to 12 carbon atoms such as a phenyl group. Examples of the halogen atom include chlorine, bromine and iodine.

In the formula, m and n are the same or different and each represents 0 or an integer of 1 to 4.

As the above aromatic dihydroxy compound,
Specific examples include the compounds shown below. That is, 1,1-bis (4-hydroxy-t-butylphenyl) propane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxybromophenyl) propane and other bis (hydroxy) Aryl)
Alkanes, 1,1-bis (4-hydroxyphenyl)
Bis (hydroxyaryl) such as cyclopentane and 1,1-bis (4-hydroxyphenyl) cyclohexane
Cycloalkanes, 4,4′-dihydroxydiphenyl ether, dihydroxyaryl ethers such as 4,4′-dihydroxy-3,3′-dimethylphenyl ether, 4,4′-dihydroxydiphenyl sulfide,
4,4′-dihydroxy-3,3′-dimethyldiphenyl sulfide and other dihydroxydiaryl sulfides, 4,4′-dihydroxydiphenyl sulfoxide,
4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide and other dihydroxydiaryl sulfoxides, 4,4'-dihydroxydiphenyl sulfone,
Examples thereof include dihydroxydiarylsulfones such as 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone.

Of these, 2,2-bis (4-
Hydroxyphenyl) propane (bisphenol A) is preferably used. These aromatic dihydroxy compounds can be used alone or in combination.

Specific examples of the carbonic acid diester used in the present invention include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate, dialkyl carbonates such as dimethyl carbonate and diethyl carbonate, and alkyl alkyls such as methylphenyl carbonate and ethylphenyl carbonate. Aryl carbonates etc. can be mentioned.

Of these, ciphenyl carbonate is particularly preferably used. These aromatic dihydroxyl compounds can be used alone or in combination. These carbonic acid diester compounds are used in excess with respect to 1 mol of the aromatic dihydroxy compound, preferably 1.01.
It is desirable to use 1 to 1.20 mol.

The alkali metal compound used as a catalyst in the present invention includes alkali metal hydroxides, hydrocarbons, carbonates, acetates, nitrates, nitrites, phosphites, cyanates, thiocyanates and stearines. Examples thereof include acid salts, borohydride salts, benzoate salts, borohydrides, bisphenols and phenol salts.

As specific examples, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium acetate, potassium acetate, lithium acetate, nitric acid. Sodium, potassium nitrate,
Lithium nitrate, sodium nitrite, potassium nitrite, lithium nitrite, sodium sulfite, potassium sulfite, lithium sulfite, sodium cyanate, potassium cyanate, lithium cyanate, sodium thiocyanate, potassium thiocyanate, lithium thiocyanate, sodium stearate , Potassium stearate, lithium stearate, sodium borohydride, lithium borohydride, potassium borohydride, sodium phenyl borohydride, sodium benzoate, potassium benzoate, lithium benzoate, disodium hydrogen phosphate, hydrogen phosphate Examples thereof include dipotassium, dilithium hydrogen phosphate, bisphenol A disodium salt, dipotassium salt, dilithium salt, phenol sodium salt, potassium salt, and lithium salt.

The catalyst may be used in an amount of 10 ^-7 to 10 ^-5 mol per 1 mol of the aromatic dihydroxy compound. If it deviates from the above-mentioned range of use, there are problems that various properties of the obtained polycarbonate are adversely affected, that the transesterification reaction does not proceed sufficiently and a high molecular weight polycarbonate cannot be obtained.

As the nitrogen-containing basic compound, tetramethylammonium hydroxide (Me ₄ NOH), tetraethylammonium hydroxide (Et ₄ NOH), tetrabutylammonium hydroxide (Bu ₄ NOH),
Benzyltrimethylammonium hydroxide (φ-C
H ₂ (Me) ₃ NOH), ammonium hydroxides having alkyl, aryl and araryl groups such as hexadecyltrimethylammonium hydroxide, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine and hexadecyldimethylamine. Or tetramethylammonium borohydride (Me ₄ NBH ₄ ), tetrabutylammonium borohydride (Bu ₄ NBH ₄ ), tetrabutylammonium tetraphenylborate (Bu ₄ NBPh)
₄ ) and basic salts such as tetramethylammonium tetraphenylborate (Me ₄ NBPh ₄ ).

In the nitrogen-containing basic compound, it is preferable to use 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol of ammonium nitrogen atom in the nitrogen-containing basic compound per 1 mol of the aromatic dihydroxy compound. A more preferable ratio is 2 × 1 based on the same criteria.
It is 0 ^{-5 to} 7 × 10 ^-4 mol. A particularly desirable ratio is 5 × 10 ^{−5 to} 5 × 10 ⁻⁴ mol based on the standard.

The phosphorus compound (i) used in the present invention is a compound represented by the following formula (I).

[0035]

[Chemical 8]

Examples of the alkyl group for R ¹¹ include a hexyl group and a dodecyl group. A phenyl group is mentioned as an aryl group. Examples of the alkyl group of R ^{12 to} R ¹⁵ include a butyl group and an octyl group.

Specifically, hexyl sulfonic acid tetramethylphosphonium salt, hexyl sulfonic acid tetraethylphosphonium salt, hexyl sulfonic acid tetrabutyl phosphonium salt, hexyl sulfonic acid tetrahexyl phosphonium salt, hexyl sulfonic acid tetraoctyl phosphonium salt, octyl sulfonic acid. Tetramethylphosphonium salt, octylsulfonic acid tetraethylphosphonium salt,
Octyl sulfonic acid tetrabutyl phonium salt, octyl sulfonic acid tetrahexyl phosphonium salt, octyl sulfonic acid tetraoctyl phosphonium salt, decyl sulfonic acid tetramethyl phosphonium salt, decyl sulfonic acid tetraethyl phosphonium salt, decyl sulfonic acid tetrabutyl phosphonium salt, decyl sulfonic acid Tetrahexylphosphonium salt, decylsulfonic acid tetraoctylphosphonicium salt, dodecylsulfonic acid tetramethylphosphonium salt, dodecylsulfonic acid tetraethylphosphonium salt, dodecylsulfonic acid tetrabutylphosphonium salt,
Dodecylsulfonic acid tetrahexylphosphonium salt, dodecylsulfonic acid tetraoctylphosphonium salt, hexadecylsulfonic acid tetramethylphosphonium salt, hexadecylsulfonic acid tetraethylphosphonium salt, hexadecylsulfonic acid tetrabutylphosphonium salt, hexadecylsulfonic acid tetrahexylphosphonium salt , Hexadecyl sulfonic acid tetraoctylphosphonium salt,
Benzenesulfonic acid tetramethylphosphonium salt, benzenesulfonic acid tetraethylphosphonium salt, benzenesulfonic acid tetrabutylphosphonium salt, benzenesulfonic acid tetrahexylphosphonium salt, benzenesulfonic acid tetraoctylphosphonium salt, toluenesulfonic acid tetramethylphosphonium salt, toluenesulfonic acid Tetraethylphosphonium salt, toluenesulfonic acid tetrabutylphosphonium salt, toluenesulfonic acid tetrahexylphosphonium salt, toluenesulfonic acid tetraoctylphosphonium salt, dodecylbenzenesulfonic acid tetramethylphosphonium salt, dodecylbenzenesulfonic acid tetraethylphosphonium salt, dodecylbenzenesulfonic acid tetra Butylphosphonium salt, tetradecyl dodecylbenzene sulfonate Ruhosuhoniumu salts, dodecylbenzenesulfonate tetraoctyl phosphonium salts.

The amount of the phosphorus compound used is 1 to 200 ppm, preferably 5 to 1 with respect to the polycarbonate.
Add in an amount of 50 ppm. By adding the above phosphorus compound, the decomposition of the polymer due to heat aging, that is, the decrease in the molecular weight can be significantly reduced.

The phenolic compound (i
i) is a compound represented by the following formula (II) -a or (II) -b.

[0040]

[Chemical 9]

Specifically,

[0042]

[Chemical 10]

And the like.

Sulfur-based compound (iii) used in the present invention
Is a compound represented by the following formula (III) -a or (III) -b.

[0045]

[Chemical 11]

Specifically,

[0047]

[Chemical 12]

And the like.

The amount of the above-mentioned phenol compound (ii) and / or sulfur compound (iii) used is 50 to 2000 ppm, preferably 100 to 15 ppm, based on the polycarbonate.
Add in an amount of 00 ppm. The above phenolic compound (i
By using i) and / or the sulfur-based compound (iii), the deterioration of the hue of the polymer due to heat aging can be reduced. On the other hand, if the content deviates from the above range, the effect of the agent is not sufficiently exerted, and deterioration of the hue of the polymer due to heat aging cannot be reduced. Alternatively, there are problems such as deterioration of polymer hue and mechanical properties, which is not preferable.

That is, in order to achieve the object of the present invention, it is necessary to add a predetermined amount of the phosphorus compound (i) and the phenol compound (ii) compound and / or the sulfur compound (iii) to the obtained polycarbonate. Is.

The method of adding the phosphorus compound and the phenol compound and / or the sulfur compound to the polymer is not particularly limited. For example, they may be added while the reaction product polycarbonate is in a molten state, or may be added by pelletizing the polycarbonate and then re-melting it, but it is preferable to add it while it is in a molten state. Good to do.

In the former case, the polycarbonate obtained by the completion of the reaction is added in the molten state while the polycarbonate, which is the reaction product in the reactor or the extruder, is added to form the polycarbonate. After that, it may be pelletized through an extruder, or
The desired aromatic polycarbonate resin can be obtained by adding and kneading while the polycarbonate obtained by the polymerization reaction is pelletized from the reactor through the extruder. Further, the order of adding the phosphorus compound and the phenol compound and / or the ionic compound does not matter.

In the present invention, the polycarbonate obtained by the polymerization accelerating reaction has the usual heat stability, ultraviolet absorber, release agent, colorant, antistatic agent, lubricant, antifogging agent, etc. within the range not impairing the object of the present invention. Natural oil, synthetic oil, wax, organic filler, inorganic filler and the like may be added.

Production of a prepolymer by transesterification of an aromatic dihydroxy compound and a carbonic acid diester
It can be carried out under the same conditions as the conventionally known ordinary method.

Specifically, the first-step reaction is carried out at 80 to 25
Aromatic at a temperature of 0 ° C., preferably 100 to 230 ° C., more preferably 120 to 190 ° C., for 0.5 to 5 hours, preferably 1 to 4 hours, more preferably 1.5 to 3 hours. The dihydroxy compound and diallyl carbonate are reacted. Then, the reaction temperature is raised while raising the vacuum system of the reaction system to carry out the reaction of the aromatic dihydroxy compound and diallyl carbonate, and finally, under reduced pressure of 5 Torr or less, preferably 1 Torr or less, 240 to
The transesterification reaction between the aromatic dihydroxy compound and diallyl carbonate is carried out at 320 ° C. The transesterification reaction as described above may be carried out continuously or batchwise. Further, the reaction apparatus used for carrying out the above reaction may be of a tank type, a tube type or a column type.

The prepolymer which is the reaction product obtained as described above usually has an intrinsic viscosity of 0.1 to 1.0,
More preferably, it is 0.2 to 0.8.

[0057]

According to the present invention, when an aromatic polycarbonate resin is produced by melt polycondensation of an aromatic dihydroxy compound and a carbonic acid diester in the presence of a specific catalyst,
By using the compounds of the above formulas (I) to (III), an aromatic polycarbonate resin having excellent hue and heat aging resistance can be produced.

[0058]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.
In the examples, the intrinsic viscosity [η], the terminal hydroxyl group concentration b value, the heat aging test, and the color difference (ΔE) before and after the polycarbonate were evaluated by the following methods.

(1) Intrinsic viscosity [η]: 2 in methylene chloride
It was measured with an Ubbelohte viscometer at 0 ° C.

(2) Terminal hydroxyl group concentration: sample 0.02
g in 0.4 ml chloroform and dissolve at 20 ° C for 1H
-Terminal hydroxyl groups and terminal phenyl groups were measured using NMR (EX-270 manufactured by JEOL Ltd.), and the terminal hydroxyl group concentration was measured by the following formula. Terminal hydroxyl concentration (%) = (terminal hydroxyl concentration / total number of terminals)
× 100

(3) b value: A 2 mm plate sample was measured by a reflection method using Nippon Denshoku Industries Co., Ltd. Z-300A.

(4) Heat aging test: Heat treatment was carried out in an air oven at 150 ° C. for 10 days. (i) ΔE: The hue after the heat aging test was measured using Nippon Denshoku Industries Co., Ltd. Z-300A, and the color difference before and after the test (Δ
E) was calculated from the following formula.

[0063]

[Equation 1] ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2

(Ii) The rate of decrease in intrinsic viscosity was determined by the following formula.

[0065]

[Equation 2]

Reference Examples 1 to 4 and Comparative Example 1 228 parts of bisphenol A, diphenyl carbonate 2
Twenty-five parts and the types and amounts of catalysts shown in Tables 1 to 3 were charged into a reaction tank equipped with a stirrer, a distiller and a decompressor, and the atmosphere was replaced with nitrogen. After stirring for 30 minutes,
The internal temperature was raised to 180 ° C., the reaction was carried out at 100 mmHg for 30 minutes, and the produced phenol was distilled off. Further 200
The pressure was gradually reduced while the temperature was raised to 0 ° C., and the reaction was carried out while distilling phenol off at 50 mmHg for 30 minutes.

Then, the temperature is gradually raised to 220 mm and 30 mmHg, and the pressure is reduced. At the same temperature and pressure for 30 minutes, 240 ° C.
10 mmHg, 260 ° C., 1 mmHg, 270 ° C., 0.
The temperature was raised and the pressure was reduced to 5 mmHg by the same procedure as above, and finally polymerization was carried out at the same temperature and the same pressure for 1 hour.

Next, in the molten state, this polymer was mixed with a gear pump in a twin-screw extruder (L / D = 40, barrel temperature 28).
The mixture was transferred to 0 ° C.), and the compounds of the types and amounts shown in Tables 1 to 3 were added and kneaded to obtain the target polymer.

The obtained polymer was dried and injection-molded (molding machine: machine name M-50B, cylinder temperature: 320).
A mold plate having a thickness of 2 mm was obtained.

The intrinsic viscosity, b value and hydroxyl group terminal ratio of the obtained molded product were measured. Further, a heat aging test was performed to measure the rate of decrease in intrinsic viscosity after the test and the color difference (ΔE) before and after the test.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08L 69/00 C08L 69/00 (56) Reference JP-A-8-59975 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) C08G 64/00-64/42 C08L 69/00

Claims (2)

(57) [Claims] 1. An aromatic polycarbonate resin obtained by a melt polycondensation method from an aromatic dihydroxy compound and a carbonic acid diester.
The rate of decrease in intrinsic viscosity is 5 after heat treatment at 50 ° C for 10 days.
% And a color difference (ΔE) of 10 or less, an aromatic polycarbonate resin. 2. An aromatic dihydrmex compound and a carbonic acid diester are used as a polycondensation catalyst in an amount of 1 × 1 per 1 mol of the aromatic dihydroxy compound (a).
1 × 1 to 1 mol of 0 ⁻⁷ to 1 × 10 ⁻⁵ mol of alkali metal compound and / or (b) aromatic dihydroxy compound
After melt polycondensation in the presence of 0 ⁻⁵ to 1 × 10 ⁻³ mol of a nitrogen-containing basic compound, and then the intrinsic viscosity [η] measured at 20 ° C. in methylene chloride reaches at least 0.1,
(i) 1 to 200 ppm based on the polycarbonate produced
The following formula (I) of the ratio of The phosphorus compound represented by the formula (ii), and (ii) the resulting polycarbonate in a proportion of 50 to 2000 ppm with respect to the following formula (I
Phenolic compounds represented by I) -a or (II) -b And / or (iii) A sulfur-based compound represented by the following formula (III) -a or (III) -b in a proportion of 50 to 2000 ppm relative to the produced polycarbonate: 2. The method for producing an aromatic polycarbonate resin according to claim 1, wherein the polycarbonate having a desired intrinsic viscosity is added.