JPH09165505A - Production of polycarbonate resin blend - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polycarbonate resin blend having excellent heat stability, resistance to hydrolysis and hue by adding an antioxidant and a phosphorus- based processing stabilizer to a specific polycarbonate resin, blending, and drying at a specific temperature for a prescribed time. SOLUTION: (A) A polycarbonate obtained by subjecting (A1 ) a bifunctional phenol such as a compound of the formula (R<1> and R<2> are each H, a 1-8C (branched) alkyl or phenyl; X is a halogen; (n) is 0-4) and (A2 ) a diester carbonate such as diphenyl carbonate to melt polycondensation in the presence of (A3 ) a transesterification catalyst such as a basic nitrogen compound, an alkaline (earth) metal or boric acid (ester) is added with (B) an antioxidant such as a hindered phenol compound and (C) a phosphorus-based processing stabilizer such as a phosphite compound respectively in an amount of, e.g. 0.01-1wt.% based on the component A and blended to obtain a blended material. Next, the resultant blend is dried and held below a glass transition temperature of the component A, e.g. at 120 deg.C for >=4hr to obtain the objective blend.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polycarbonate resin mixture obtained by adding an antioxidant and a phosphorus-based processing stabilizer to a polycarbonate resin obtained by polycondensing a dihydric phenol and a carbonic acid diester in the presence of a transesterification catalyst. When the resulting polycarbonate resin mixture is below the glass transition temperature of the polycarbonate resin, heat stability obtained by holding a drying time over a certain time, hydrolysis resistance, and a method for producing a polycarbonate resin mixture excellent in hue It is a thing.

[0002]

BACKGROUND OF THE INVENTION The high molecular weight polycarbonate resins of the present invention are versatile engineering thermoplastics having a wide range of applications, especially for injection molding or as a glass sheet alternative to window glass. Polycarbonate resins are generally said to have excellent heat resistance, transparency, and impact resistance. The manufacturing method of polycarbonate resin is
A phosgene method in which a dihydric phenol and phosgene are subjected to interfacial polycondensation to react, a melt transesterification method in which a dihydric phenol and a carbonic acid diester are reacted in a molten state, and the like are generally known. As a typical example of the melt transesterification method, an ester exchange catalyst is added to a dihydric phenol and a carbonic acid diester to synthesize a prepolymer while distilling phenol under heating and reduced pressure, and finally under high vacuum, 290 A method for obtaining a high-molecular-weight polycarbonate by heating above ° C to distill phenol to obtain a high-molecular-weight polycarbonate (US Patent No. 4345).
No. 062). In the melt transesterification method, in order to allow the reaction to proceed efficiently, the prepolymer is synthesized in a tank reactor having an ordinary stirring blade in the initial stage of the reaction, and then a self-cleaning type extruder with a vent is used. It is known to carry out a polycondensation reaction using an apparatus (Japanese Patent Publication No. 6-99552). However, unlike other engineering plastics, high-molecular-weight polycarbonate has an extremely high melt viscosity, and thus requires a high temperature of 270 ° C. or higher as a reaction condition,
In addition, in order to distill the carbonic acid diester and divalent phenol compound having a high boiling point from the highly viscous substance, a high vacuum (1 × 1
Since it requires 0 ⁻² Torr), it was considered difficult from the viewpoint of equipment.

Polymerization catalysts used in the production of polycarbonate by the transesterification method generally include alkali metal or alkaline earth metal hydroxides, hydrides, oxides, alcoholates, carbonates and acetates. .
However, since these basic catalysts remain in the final product, the heat resistance stability of the polycarbonate resin,
There has been a problem that hydrolysis resistance, molding retention stability, weather resistance hue and the like are significantly reduced. One method of solving these problems is to add a third component to the reaction solution to weaken the effect of the basic catalyst. As an example, British Patent Publication (BP1031512) discloses that this problem can be avoided by adding a substance that binds to a base to a molten resin near the end point of a transesterification reaction to neutralize the basicity. . However, these methods have a problem that it is difficult to uniformly mix a small amount of an additive with a resin having a high melt viscosity in a short time. Another solution is to change the type of catalyst itself. As an example, Japanese Patent Publication Sho 46-2050
No. 4 discloses a method using tetrafluoroborate or hydroxyfluoroborate as a catalyst. However, in this case, the catalyst contains halogen atoms, which may cause corrosion of the device and deterioration of resin characteristics. Further, JP-A-2-124934 discloses that such a decomposition reaction can be prevented by using a nitrogen-containing basic compound, an alkali (earth) metal compound and boric acid (ester) as a polymerization catalyst. In this case, there has been a problem that three kinds of polymerization catalysts are used.

[0004]

DISCLOSURE OF THE INVENTION The invention relates to the heat resistance stability of a polycarbonate resin obtained by polycondensing a dihydric phenol and a carbonic acid diester in the presence of a transesterification catalyst,
It is a method for producing a polycarbonate resin mixture that improves hydrolysis resistance and retains a hue.

[0005]

The present inventors have added an antioxidant and a phosphorus-based processing stabilizer to a polycarbonate resin obtained by polycondensing a dihydric phenol and a carbonic acid diester in the presence of a transesterification catalyst. It has been found that, when a polycarbonate resin mixture is obtained by holding the polycarbonate resin mixture at a temperature not higher than the glass transition temperature of the polycarbonate resin and a drying time exceeding a certain time, the problems associated with the above-mentioned conventional techniques can be solved. The present invention has been completed.

Particularly, a polycarbonate resin obtained by using at least one catalyst selected from the group consisting of basic nitrogen compounds, alkali metals and alkaline earth metals, boric acid and boric acid esters as an ester exchange catalyst is excellent. Furthermore, 4,4-dimethylaminopyridine is most preferable as the basic nitrogen compound, and lithium borate and lithium hydroxide are most preferable as the alkali metal. Comparing these polymerization catalysts with other basic compounds, they are the same in that they promote the transesterification reaction, but 4,4-dimethylaminopyridine, lithium borate, and lithium hydroxide were used. In this case, if the mixture of the polycarbonate resin with the antioxidant and the phosphorus-based processing stabilizer is kept at a temperature not higher than the glass transition temperature of the polycarbonate resin for a drying time longer than a certain time, the decomposition reaction by heat and water will occur. A significant difference was observed in that it was remarkably suppressed, the heat stability and the hydrolysis resistance were retained, and the hue was improved.

That is, the present invention provides (1) a polycarbonate resin mixture obtained by adding an antioxidant and a phosphorus-based processing stabilizer to a polycarbonate resin obtained by melt polycondensation of a dihydric phenol and a carbonic acid diester in the presence of an ester exchange catalyst. The method for producing a polycarbonate resin mixture, wherein the obtained polycarbonate resin mixture is dried and maintained at a temperature not higher than the glass transition temperature of the polycarbonate.

(2) As the transesterification catalyst, at least one catalyst selected from the group consisting of basic nitrogen compounds, alkali metals and alkaline earth metals, boric acid and boric acid esters is used. 1) A method for producing a polycarbonate resin mixture as described above. (3) The polycarbonate according to (1) or (2) above, wherein the amount of the antioxidant and the phosphorus-based processing stabilizer added to the polycarbonate resin is in the range of 0.01 to 1% by weight. A method for producing a resin mixture. (4) When a polycarbonate resin mixture is obtained by adding an antioxidant and a phosphorus-based processing stabilizer to a polycarbonate resin obtained by melt polycondensation,
The method for producing a polycarbonate resin mixture according to the above (1), (2) or (3), characterized in that the obtained polycarbonate resin mixture is kept at 120 ° C. or less for a drying time of more than 4 hours.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As typical examples of dihydric phenols, the following general formulas (1) to (4) are shown.

Embedded image And a compound that can be represented by any of the above.

(In the formula, R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each a hydrogen atom or a linear or branched alkyl group having 1 to 8 carbon atoms, or a phenyl group, and X is a halogen. Atom, and n = 0-4, m = 1-4.) As the divalent phenol classified into the general formula (1), 2,
2-bis- (4-hydroxyphenyl) propane, 2,
2-bis- (4-hydroxyphenyl) -4-methylpentane, 2,2-bis- (4-hydroxyphenyl) octane, 4,4'-dihydroxy-2,2,2-triphenylethane, 2,2-bis- (3,5-dibromo-4)
-Hydroxyphenyl) propane and the like.

As the dihydric phenol classified in the general formula (2), 2,2-bis- (4-hydroxy-3-methylphenyl) propane, 2,2-bis- (4-hydroxy-3-isopropylphenyl) propane, 2,2-bis- (4-hydroxy-) Examples thereof include 3-secondary butylphenyl) propane and 2,2-bis- (4-hydroxy-3-tert-butylphenyl) propane.

As the dihydric phenol classified in the general formula (3), 1,1'-bis- (4-hydroxyphenyl)
-Para-diisopropylbenzene, 1,1'-bis- (4-hydroxyphenyl) -meta-diisopropylbenzene and the like.

As the dihydric phenol classified in the general formula (4), 1,1'-bis- (4-hydroxyphenyl)
Cyclohexane and the like. Of these, 2,2-bis- (4-hydroxyphenyl) propane is particularly preferable. Furthermore, it is also possible to produce a copolymerized polycarbonate resin in which two or more dihydric phenols selected from the compounds represented by the general formulas (1) to (4) are combined.

As a typical example of carbonic acid diester,
Examples thereof include diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, bis (cyanophenyl) carbonate, meta-cresyl carbonate, dinaphthyl carbonate, diethyl carbonate, dimethyl carbonate, dibutyl carbonate and dicyclohexyl carbonate. Of these, diphenyl carbonate is particularly preferable. When the polycarbonate resin is produced in the present invention, the above carbonic acid diester needs to be equimolar to the dihydric phenol present in the reaction system. Generally, in order to produce a high molecular weight polycarbonate, 1 mol of the carbonate compound and 1 dihydric phenol are used.
Mole must react. For example, when diphenyl carbonate is used, 2 mol of phenol is produced by the above reaction. These 2 moles of phenol are distilled out of the reaction system. However, when the monohydric phenol compound generated to promote the reaction is distilled out of the system, the carbonic acid diester, which is a monomer, may also be distilled off at the same time. Therefore, the carbonic acid diester used is 1 mol of the dihydric phenol. It is preferably used in an amount of 1.01 to 1.5 mol.

In the present invention, a commercially available hindered phenol compound is used as the antioxidant mixed with the polycarbonate resin. Typical examples of hindered phenol compounds include octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl). Propionate], 1,6-hexanediol [3- (3,5-ditertiarybutyl-4-hydroxyphenyl) propionate], pentaerythrityl-tetrakis [3- (3,5-ditertiarybutyl-4-hydroxyphenyl) ) Propionate], 2,4-bis- (normal-octylthio) -6- (4-hydroxy-3,5-ditertiarybutylanilino) -1,3,5-triazine, 2,2-thiodiethylenebis [3- ( 3,5-ditertiary butyl-4-hydr Kishifeniru) propionate] and the like. Further, the above-mentioned hindered phenol compounds can be used in a combination of two or more kinds.

As the phosphorus-based processing stabilizer mixed with the polycarbonate resin in the present invention, commercially available phosphite compounds and phosphonite compounds are used. Typical examples of the phosphite compound include triethyl phosphite, triisopyropyl phosphite, tridodecyl phosphite, phenyldiisodecyl phosphite, diphenylisodecyl phosphite, tristolyl phosphite, phenyl-bis (4-nonylphenyl) phosphite, Tris- (4-octylphenyl) phosphite, tris- (2,4-ditertaliphenylphenyl) phosphite, tris- [4- (1-phenylethyl) phenyl] phosphite, pentaerythritol [(2,4-ditert-butylphenyl)) Phosphite], pentaerythritol [(2,6-ditertiarybutyl-4-methylphenyl)
Phosphite] and the like. Typical examples of the phosphonite compound include tetrakis (2,4-ditertalibutylphenyl) -4,4'-biphenylenephosphonite.

The total amount of the antioxidant and the phosphorus-based processing stabilizer added is preferably 0.02% by weight to 2% by weight with respect to the polycarbonate resin. Further, preferably,
It is 0.05% by weight to 1% by weight with respect to the polycarbonate resin. If the addition amount is 0.05% by weight or less, it has little effect on heat stability, hydrolysis resistance, and hue improvement, and 1% by weight.
If it exceeds, the melt flow index becomes large and the impact resistance and the hue decrease, which is not preferable. Further, the proportion of the antioxidant and the phosphorus-based processing stabilizer added is preferably 1 to 5% by weight of the phosphorus-based processing stabilizer with respect to 1% by weight of the antioxidant. If the addition amount of the phosphorus-based processing stabilizer is less than 1% by weight with respect to 1% by weight of the antioxidant, it is not effective in improving the hue, and if it exceeds 5% by weight, the physical properties of the polycarbonate resin are adversely affected. Not preferable.

When an antioxidant and a phosphorus-based processing stabilizer are added to the polycarbonate resin to keep the polycarbonate resin mixture at a glass transition temperature below the polycarbonate resin for a drying time exceeding a certain time, the drying temperature is 120 ° C.
If it is less than 120 ° C, water contained in the polycarbonate resin cannot be sufficiently distilled off, and if it exceeds 120 ° C, the physical properties of the polycarbonate resin mixture are adversely affected. Also, the drying time is 4
If it is less than the time, the water content contained in the polycarbonate resin cannot be sufficiently distilled off, and even if it is dried for a long time, energy is wasted and the manufacturing cost is increased, which is not preferable.

A drying time of 10 hours is suitable.

The amount of the basic nitrogen compound used as a catalyst is 10 with respect to 1 mol of the dihydric phenol present in the reaction system.
^-6 mol to 10 ^-1 mol is preferable, more preferably 1
It is 0 ^-4 mol to 10 ^-2 mol. If it is less than 10 ⁻⁶ mol, the catalytic action is small and the polymerization rate of the polycarbonate resin becomes slow. If it exceeds 10 ^-1 mol, the amount of catalyst remaining in the produced polycarbonate resin increases, resulting in deterioration of physical properties.

Furthermore, the amount of at least one catalyst selected from the group consisting of alkali metals and alkaline earth metals, boric acid and boric acid esters is added to 1 mol of the dihydric phenol present in the reaction system. The amount is preferably 10 ^-8 mol to 10 ^-2 mol, more preferably 10 ^-6 mol to 10 ^-3 mol. If it is less than 10 ^-8 mol, there is no effect of adding at least one catalyst selected from the group consisting of alkali metals and alkaline earth metals, boric acid and boric acid esters, and if it exceeds 10 ^-2 mol, a polycarbonate resin produced Since the amount of the catalyst remaining therein increases, the physical properties are deteriorated.

[0022]

The polycarbonate resin mixture obtained by the production method of the present invention is excellent in heat stability, hydrolysis resistance and hue.

[0023]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited by these examples.

(Synthesis Example 1) 4,560 g (20 mol) of 2,2-bis (4-hydroxyphenyl) propane and 43 diphenyl carbonate were placed in a nickel-clad tank reactor.
91.5 g (20.5 mol) and N, N-dimethyl-4-aminopyridine 489 mg (4 × 10 ⁻³ mol) were added, and the mixture was melted at 160 ° C. under nitrogen, stirred for 1 hour, and gradually heated under reduced pressure. Finally 1 torr, 4 at 270 ° C
Polycondensation was carried out for a period of time, the produced phenol was distilled off, and the reaction was further carried out for 50 minutes in a biaxial self-cleaning reactor to obtain a colorless transparent polycarbonate resin. When the viscosity average molecular weight (Mv) of the obtained polycarbonate resin was measured, it was Mv = 24,000.

The viscosity average molecular weight can be measured by measuring the intrinsic viscosity [η] of the methylene chloride solution at 20 ° C. using an Ubbelohde viscometer, and using the following equation.
Was calculated.

[Η] = 1.11 × 10 ⁻⁴ (Mv) ^{0.82 When} the YI (yellow index) value was used as an index indicating the degree of coloring, YI = 2.0.

The YI value is measured by a thickness of 2 mm and 50 mm.
A sheet of × 50 mm was prepared by the hot press quenching method and measured using Nippon Denshoku Co., Ltd. 300A.

(Synthesis Example 2) 4,560 g (20 mol) of 2,2-bis (4-hydroxyphenyl) propane and 43 of diphenyl carbonate were placed in a nickel-clad tank reactor.
91.5 g (20.5 mol), meta an aqueous solution of lithium borate · dihydrate 17 mg (2 × 10 ^-4 mol) was added, after thawing under nitrogen at 180 ° C., and stirred for 1 hour, the temperature while the pressure was gradually reduced By heating, finally polycondensing at 1 Torr, 270 ° C. for 4 hours, distilling off the produced phenol, and further reacting for 45 minutes in a twin-screw self-cleaning type reactor,
A colorless and transparent polycarbonate resin was obtained. When the viscosity average molecular weight (Mv) of the obtained polycarbonate resin was measured, it was Mv = 25,000 and YI = 1.9.

(Synthesis Example 3) 4,560 g (20 mol) of 2,2-bis (4-hydroxyphenyl) propane and 43 diphenyl carbonate were placed in a nickel-clad tank reactor.
91.5 g (20.5 mol), tetramethylammonium hydroxide 445 mg (0.005 mol), sodium 0.8 mg (2 × 10 ^-5 mol) hydroxide, 3.1 mg of boric acid (5 × 10 ^-5 mol ) Is added and nitrogen is added to 160
After melting at ℃, stir for 1 hour, gradually raise the temperature while reducing the pressure, and finally polycondensate at 1 torr, 270 ℃ for 4 hours, distill off the produced phenol, and further use a biaxial self-cleaning reactor. The colorless and transparent polycarbonate resin was obtained by reacting for 45 minutes. When the viscosity average molecular weight (Mv) of the obtained polycarbonate resin is measured,
Mv = 29,500 and YI = 2.5.

(Synthesis Example 4) 4,560 g (20 mol) of 2,2-bis (4-hydroxyphenyl) propane and 43 diphenyl carbonate were placed in a nickel-clad tank reactor.
91.5 g (20.5 mol), tetramethylammonium hydroxide 445 mg (0.005 mol), sodium hydroxide 0.8mg of (2 × 10 ^-5 mol) was added, after thawing under nitrogen at 160 ° C., 1 hour By stirring, gradually increasing the temperature while reducing the pressure, finally polycondensing at 1 torr, 270 ° C. for 4 hours, distilling off the produced phenol, and further reacting for 45 minutes in a twin-screw self-cleaning reactor. A colorless and transparent polycarbonate resin was obtained. When the viscosity average molecular weight (Mv) of the obtained polycarbonate was measured, it was Mv = 29,000. YI = 2.3.

[0031]

Example 1 To 100 g of the polycarbonate resin obtained in (Synthesis Example 1), 0.1 g of pentaerythrityl-tetrakis [3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate] and tris- (2 0.1 g of 4-ditert-butylphenyl) phosphite was thoroughly mixed using a tumbler and dried in a dryer at 120 ° C. for 1 hour.
Dried for 2 hours.

[0032]

Example 2 To 100 g of the polycarbonate resin obtained in (Synthesis example 2) was added 0.1 g of pentaerythrityl-tetrakis [3- (3,5-ditertalibutyl-4-hydroxyphenyl) propionate] and tris (2,3). 0.1 g of 4-ditert-butylphenyl) phosphite was thoroughly mixed using a tumbler and dried in a dryer at 120 ° C. for 1 hour.
It was dried for 0 hours.

[0033]

Example 3 To 100 g of the polycarbonate resin obtained in (Synthesis example 3) was added 0.1 g of pentaerythrityl-tetrakis [3- (3,5-ditertalibutyl-4-hydroxyphenyl) propionate] and tris (2,3). 0.1 g of 4-ditert-butylphenyl) phosphite was thoroughly mixed using a tumbler and dried in a dryer at 120 ° C. for 1 hour.
It was dried for 0 hours.

[0034]

Example 4 To 100 g of the polycarbonate resin obtained in (Synthesis example 4), 0.1 g of pentaerythrityl-tetrakis [3- (3,5-ditertalibutyl-4-hydroxyphenyl) propionate] and tris- (2 0.1 g of 4-ditert-butylphenyl) phosphite was thoroughly mixed using a tumbler and dried in a dryer at 120 ° C. for 1 hour.
Dried for 2 hours.

[0035]

Example 5 To 100 g of the polycarbonate resin obtained in (Synthesis example 1) was added 0.1 g of pentaerythrityl-tetrakis [3- (3,5-ditertalibutyl-4-hydroxyphenyl) propionate] and tris (2,3). 0.2 g of 4-ditert-butylphenyl) phosphite was thoroughly mixed using a tumbler and dried in a drier at 120 ° C. for 1 hour.
It was dried for 0 hours.

[0036]

Example 6 To 100 g of the polycarbonate resin obtained in (Synthesis example 2) was added 0.1 g of octadecyl-3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate and tris- (2,4-ditert-butylphenyl). ) 0.1 g of phosphite was thoroughly mixed using a tumbler and dried in a dryer at 120 ° C for 12 hours.

[0037]

Example 7 100 g of the polycarbonate resin obtained in (Synthesis example 1) was added with 0.1 g of octadecyl-3- (3,5-ditert-butyl-4-hydroxyphenyl) propionate and tetrakis (2,4-ditert-butylphenyl). ) -4,4'-Biphenylenephosphonite 0.1g
Mix well using a tumbler and dry at 120 ° C.
Then, it was dried for 12 hours.

[0038]

Example 8 0.1 g of pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and tetrakis (2,2) were added to 100 g of the polycarbonate resin obtained in (Synthesis example 2). 0.1 g of 4-ditertiarybutylphenyl) -4,4'-biphenylenephosphonite was thoroughly mixed using a tumbler, and dried in a dryer at 120 ° C for 12 hours.

[0039]

[Comparative Examples 1 to 4] The polycarbonate resins obtained in (Synthesis Examples 1 to 4) were dried in a dryer at 120 ° C for 10 hours.

The results are shown in Table 1. The number of cuts shown in Table 1 is shown below.

[0041]

Embedded image

[Table 1]

Claims (4)

[Claims] 1. When a polycarbonate resin mixture is obtained by adding an antioxidant and a phosphorus-based processing stabilizer to a polycarbonate resin obtained by melt polycondensation of a dihydric phenol and a carbonic acid diester in the presence of an ester exchange catalyst, A method for producing a polycarbonate resin mixture, which comprises keeping the obtained polycarbonate resin mixture at a glass transition temperature of the polycarbonate or below in a dry state. 2. A transesterification catalyst comprising at least one catalyst selected from the group consisting of basic nitrogen compounds, alkali metals and alkaline earth metals, boric acid and boric acid esters. A process for producing the described polycarbonate resin mixture. 3. The polycarbonate according to claim 1 or 2, wherein the amount of the antioxidant and the phosphorus-based processing stabilizer added to the polycarbonate resin is in the range of 0.01 to 1% by weight. A method for producing a resin mixture. 4. When a polycarbonate resin mixture is obtained by adding an antioxidant and a phosphorus processing stabilizer to the polycarbonate resin obtained by melt polycondensation, the obtained polycarbonate resin mixture is kept at 120 ° C. or lower for 4 hours. A method for producing a polycarbonate resin mixture according to claim 1, 2 or 3, characterized in that a drying time exceeding the above is maintained.