JP2562582B2 - Method for producing polycarbonate resin - Google Patents

Description

The present invention relates to a method for producing a polycarbonate resin having excellent heat resistance. This is a particularly useful manufacturing method for obtaining an optical material.

(Prior art and its problems) It is well known that a polycarbonate is end-capped with a certain molecular weight regulator and an end terminating agent.
Non-endcapped polycarbonates are not very stable to heat because the free phenolic end groups are reaction sites that are detrimental to the stability of the carbonate polymer. Furthermore, the lack of end-capping conditions during the production of aromatic polycarbonates often results in very high molecular weight polymers which are too viscous to mold at the proper temperatures.

Standard chain terminators used in the production of aromatic polycarbonates include benzoic acid phenyl ester in the transesterification method (Japanese Patent Publication No. 46-41621), and in the phosgene method, phenol-based phenols, te
rt-Butylphenol paracumylphenol and the like are known (JP-A-51-20993, JP-A-60-203632). By using these terminal terminators, the molecular weight can be appropriately controlled, and from the viewpoint of physical properties. It is possible to obtain a polymer having good hue and thermal stability.

However, in West German Patent Application Publication No. 2716304, published October 19, 1978, a relatively long chain termination carboxylic acid or acid halide of (C ₉ ~C ₂₆₎ with conventional phenolic chain terminators Use as an agent is disclosed. In this case, the melt viscosity is lowered, thereby facilitating the processing of the resin, but at the same time, the heat resistance of the polymer is considerably lowered and the resin becomes brittle upon aging at a high temperature.

As such, the effect of end-capping agents on the properties of polycarbonates is generally not fully understood, and in this field, in determining whether a particular compound or group of compounds effectively acts as a polycarbonate end-capping agent. The empirical approach is the norm. Moreover, certain compounds should not only act as end-cappers but, when incorporated into the carbonate polymer chain as end groups, should not adversely affect the practically advantageous properties and characteristics of the polycarbonate. It's complicated. That is, the effectiveness of certain compounds as end-stoppers is not practical if the compounds adversely affect some of the preferred useful properties of the polycarbonate.

Accordingly, there is a need for end caps and molecular weight regulators with controlled molecular weight and substantially all of the other advantageous properties of polycarbonate, while at the same time having improved and improved heat resistance without compromising moldability.

(Means for Solving Problems) As a result of intensive studies as an end-stopping agent satisfying the above conditions, it was found that the organic compound represented by the general formula (1) is extremely effective in terms of heat resistance. The invention was completed.

General formula (1) (R represents hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms) That is, in the production of a polycarbonate from a dihydric phenol and a diaryl carbonate by a transesterification reaction, the following general terminator is used as a terminal stopper and a molecular weight modifier. A method for producing a polycarbonate resin, which comprises using a monofunctional organic compound represented by the formula.

General formula (In the formula, R represents hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms.) The polycarbonate resin used in the practice of the present invention is a carbonate homopolymer of a dihydric phenol, two different two It is a carbonate copolymer of a dihydric phenol or a copolymer of such a dihydric phenol and an aliphatic diol.

 The contents of the present invention will be described in detail below.

The dihydric phenol used in the practice of the present invention includes:
A known dihydric phenol in which the reactive group is two phenolic hydroxyl groups. Some of these are represented by general formula (2) Represented by Wherein A is a divalent hydrocarbon group containing 1 to about 15 carbon atoms; a substituted divalent hydrocarbon group containing 1 to about 15 carbon atoms and a halogen, -S-, -SS-, Wherein each X is independently hydrogen, halogen,
Monovalent carbon groups such as alkyl groups having 1 to about 8 carbon atoms, aryl groups having 6 to 18 carbon atoms, aralkyl groups having 7 to about 14 carbon atoms, oxyalkyl groups having 1 to about 8 carbon atoms, or 6 carbon atoms. Selected from the group consisting of ~ 18 oxyaryl groups. m is 0 or 1.

Some representative examples of dihydric phenols that can be used in the practice of this invention include bisphenols such as bis (4-
Hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl) propane (also known as bisphenol A), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxy-3,5-
Dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, etc .; divalent phenol ethers such as bis (4-hydroxyphenyl) ether, bis (3,5-dichloro-4-hydroxyphenyl) ) Ethers and the like; dihydroxydiphenyl such as p,
p'-dihydroxydiphenyl, 3,3'-dichloro-4,
4'-dihydroxydiphenyl etc .; dihydroxyaryl sulfones such as bis (4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone etc .; dihydroxybenzene, resorcinol, hydroquinone, halo- and alkyl-substituted dihydroxys. Benzene such as 1,4-dihydroxy-2,5-dichlorobenzene, 1,4-dihydroxy-3-methylbenzene, and the like; and dihydroxydiphenyl sulfide and sulfoxide such as bis (4-hydroxyphenyl) sulfide and bis (4-hydroxyphenyl) ) Sulfoxide, bis (3,5-dibromo-4-hydroxyphenyl) sulfoxide and the like. Other dihydric phenols are also available, US Pat. Nos. 2,999,835, 3028365
And No. 3153008, all of which are incorporated herein by reference. Of course, it is possible to use two or more different dihydric phenols or a combination of dihydric phenols and glycols.

The carbonate precursor of the present invention can include diaryl carbonate and diphenylphenol bisphenyl carbonate. Examples of the diaryl carbonate include bishalide diphenyl carbonate and diphenyl carbonate, and examples of the bisphenyl carbonate of a dihydric phenol include 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4-hydroxy-).
Bisphenyl carbonates such as 3,5-dichlorophenyl) propane hydroquinone. While all of the above carbonate precursors are useful, diphenyl carbonate is preferred.

Further, as a branching agent, phloroglysin, 2,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) heptene-3,4,6-dimethyl-2,4,6-tri (4-hydroxyphenyl) ) Heptene-2,1,3,5-tri (2-hydroxyphenyl) benzol, 1,1,1-tri (4-hydroxyphenyl) ethane, 2,6-bis (2-hydroxy-5-)
Methylbenzyl) -4-methylfuphenol, α,
α ', α "-tri (4-hydroxyphenyl) -1,3,5
-A polyhydroxy compound exemplified by triisopropylbenzene and the like, and 3,3-bis (4-hydroxyaryl) oxindole (-isatin bisphenol),
Examples include 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like.

In the production of the branched benzoate ester branched polycarbonate resin of the present invention, the amount of the polyfunctional phenol which is a branching agent for the divalent phenolic compound represented by the general formula (2) is usually 0.01 to 3 mol%, preferably Is
It is in the range of 0.1 to 1.0 mol%. If it is less than 0.01 mol%, a sufficient branched structure is not formed, and if it exceeds 3 mol%, a high molecular weight product is partly formed, which causes disadvantages such as deterioration of transparency of the molded product. Is not achieved.

The present invention is directed to a novel carbonate resin having a specific phenyl sulfonic acid ester as an end group. These phenyl sulfonate end groups have the general formula Represented by the general formula R obtained from the compound represented by is hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms, preferably 1 to 4 carbon atoms.

The novel carbonate polymer of the present invention has the general formula (I)
Is prepared by reacting at least one of the compounds with a dihydric phenol and a carbonate precursor.

The substituent of the monofunctional organic compound used as the terminal stopper represented by the general formula (1), R- is methyl, ethyl, n-propyl, i-propyl, n-butyl, sec.
Examples thereof include -butyl and t-butyl, but alkyl having a carbon number of 5 or more is not preferable because the heat resistance which is a feature of the present invention is impaired.

The terminating agent functions as a molecular weight regulator in the method of the present invention. When the compound originally defined by the general formula (I) is added to the reaction vessel, it not only affects the chain length but also the physical properties described above. The addition of the terminating agent can be performed from the beginning before adding the carbonate precursor. Alternatively, it can be done during the addition of the carbonate precursor and generally at any reaction point where the degree of polymerization approaches that of the higher polymers. It is preferred to add from the beginning.

The amount of endblocker added is preferably about 10,000-2.
An amount effective to make an aromatic polycarbonate having a viscosity average molecular weight of 5,000. This amount, as mol% of the dihydric phenol used in the reaction, varies from about 0.1 to 10 mol%, preferably about 0.5 to 8 mol%.

In the practice of the present invention, one of the compounds of formula (I) may be used, in which case the end groups of the carbonate polymer will generally all be the same and two or more compounds of the above formula (I) will be used. It may also be used, in which case the polymer will be in the form of a mixture of various end groups depending on the number, amount and type of compounds of the general formula (I) used. Further, the compound of the general formula (I) may be used in combination with a known phenolic or poly-end terminating agent.

The catalyst used in the present invention may be a basic catalyst, an acidic catalyst or the like, and examples thereof include the following.

(1) Alkali metals such as lithium, sodium, potassium, rubidium, cesium and francium and carbonates, hydroxides, borohydrides, phenolates, bisphenolates and carboxylates of these alkali metals,
Oxide. (Tetraalkyl ammonium borohalide,
(2) Tetraalkylammonium halide) (2) Elements of Group II and Group III of the Periodic Table, for example, metals such as calcium, magnesium and aluminum, and carbonates, hydroxides, hydrides, borohydrides of these metals, Phenolates, bisphenolates, carboxylates, oxides.

(3) Metal oxides, metal acetates, titanium and tin compounds, for example, metal oxides such as antimony trioxide, germanium oxide, arsenic trioxide, lead oxide, magnesium oxide, zinc oxide, cobalt acetate, zinc acetate, cadmium acetate, Metal acetates such as manganese acetate, titanium compounds such as tetrabutyl titanate, tetraisopropyl titanate and tetraphenyl titanate, tin compounds such as dibutyltin oxide, dibutyltin methoxide, dibutyltin laurate and monoalkyl monohydroxytin oxide.

Etc. are used, but are not particularly limited to these.

These catalysts are about 10 ^-6 to 10 ^-1 mol%, preferably about 10 ^-6 to 10 ^-1 mol%, preferably based on an effective amount of bisphenol in a conventional transesterification reaction
10 ^-4 to 10 ^-2 mol% is used.

The polycarbonate resin of the present invention may be optionally mixed with generally known and used additives. Examples of such additives include antioxidants, hydrolysis stabilizers, for example, epoxides, phosphorus compounds, phenol compounds, and other UV absorbers such as benzophenones, benzotriazoles, cyanoacrylates, and impact modifiers. Agents, fillers, color stabilizers, flame retardants and the like.

The polycarbonate resin of the present invention has excellent heat resistance, so electrical insulating parts, electrical materials such as lighting parts, greenhouses that require thermal insulation, factory buildings, sports halls, panels for indoor hot water swimming pools, etc., Other building materials, optical molding materials that can be molded at high temperature because they have excellent heat resistance without compromising fluidity, low residual strain, and low birefringence, especially optical audio digital audio discs,
Suitable as a material for video discs, memory discs, etc.

 The contents of the invention will be specifically described below by the implementation.

The measuring method of the items used for evaluating the polycarbonate obtained by the present invention is as follows.

Evaluation method of heat resistance: (i) Using a differential thermogravimetric analyzer (abbreviated as TGA manufactured by Rigaku Denki Co., Ltd.), thermal decomposition behavior was measured in a nitrogen stream at a temperature rising rate of 10 ° C./min. It represents the temperature at which weight loss due to thermal decomposition has reached 5% of the initial weight in T _5, also the temperature at which weight loss reached 10% of the initial weight in T _10, and a measure of the thermal decomposition behavior.

(Ii) Create a 50 mm x 50 mm x 0.6 mm thick sheet by heat pressing, place it on a Teflon sheet in a hot air circulation thermostat set at 160 ° C, sample after 30 days of heating time, and reduce its weight loss and viscosity average. The molecular weight was obtained and the deterioration state of the sample due to heat aging was evaluated.

Weight loss rate △ Wt% is I asked more. As the initial weight, the above heat press
The weight of a sample obtained by drying the sheet in a hot air circulation dryer at 120 ° C. for 4 hours was used.

Evaluation method of viscosity average molecular weight: The intrinsic viscosity [η] (dl / g) of a methylene chloride solution at 20 ° C. was measured using an Ube-Rohde viscosity tube, and the viscosity average molecular weight v was calculated using the following formula.

[Η] = 1.11 × 10 ⁻⁴ (v) ^0.82 Hydrolysis resistance evaluation method: 50 mm × 50 mm × by hot pressing
A 0.6 mm thick sheet was created and suspended with hemp thread in a thermo-hygrostat controlled at 90 ° C and 100% RH to prevent deterioration of the sample due to hydrolysis. Changes in viscosity average molecular weight and sheet appearance. Was measured over time. Hydrolysis test The percentage of the viscosity average molecular weight after 30 days with respect to the initial viscosity average molecular weight was referred to as the 30 day hydrolysis viscosity average molecular weight retention (%), and was used as a measure of the hydrolysis resistance along with the change in the sheet appearance after 30 days.

Melt viscosity measurement method and molecular weight stability evaluation method: 120
Sample pellets dried for 4 hours by a hot air circulation dryer set at ℃ were used by Toyo side machine Co., Ltd. Capirograph,
Melting behavior was measured at 280 ° C. After holding the sample melted at 280 ° C in the cylinder of the capillograph for 1 hour, it was extruded at a shear rate of 10 ⁵ / sec through a nozzle with a diameter of 0.5 mm and a length of 5 mm, and the viscosity average molecular weight before and after holding was measured. The stability of the molecular weight was evaluated.

Example 1 Bisphenol A228.2 was added to a reactor equipped with a stirrer and purged with nitrogen.
9 g (1.0 mol) and 219.58 g of diphenyl carbonate (1.02
5 mol), phenyl p-methylphenylsulfonate 12.41
After adding g (5 mol% to bisphenol A) and melting at 160 ° C., the catalyst KBH ₄ is added at 10 ⁻³ mol% to bisphenol A to start the reaction. The temperature is gradually raised to 270 ° C. over 3 hours, the pressure of the reaction system is also reduced to 10 mmHg, and the produced phenol is distilled off. 1-2 at 270 ℃
A polymer was obtained by reacting for 0.2 to 0.1 mmHg. The obtained polymer had excellent transparency and no coloring, and had a viscosity average molecular weight of 16,500.

TGA heat resistance test of the obtained polymer 90 ° C 100%
Results of hydrolysis resistance test at RH The results of heat resistance test at 160 ° C., melt viscosity and molecular weight stability by capillograph are shown in Tables 1 and 2.

Example 2 The same as Example 1 except that the catalyst was Li ₂ CO ₃ 10 ⁻³ mol% (based on bisphenol A). The obtained polymer has excellent transparency and a viscosity average molecular weight with no coloring at all.
It was 22,100.

Examples 3 and 4 Using the method of Example 1, polycarbonates were prepared using the molecular weight modifiers and catalysts shown in Table 1.

 The respective results are shown in Tables 1 and 2.

Comparative Example 1 Bisphenol A228.2 was added to a reactor equipped with a stirrer and purged with nitrogen.
9 g (1.0 mol) and 219.58 g of diphenyl carbonate (1.02
(5 mol) and melted at 160 ° C., and then the catalyst KBH ₄ is added at 10 ⁻³ mol% to bisphenol A to start the reaction. Gradually raise the temperature to 270 ° C over 3 hours and set the reaction system pressure to 1
The pressure is reduced to 0 mmHg and the produced phenol is distilled off. Subsequently, a polymer was obtained by reacting at 270 ° C. for 1 hour at 0.2 to 0.1 mmHg. The obtained polymer had a viscosity of 24,500, which was transparent and had little coloration. The evaluation results of the obtained polymer are shown in Tables 1 and 2.

 The heat stability is inferior to the examples of the present invention.

Comparative Example 2 Bisphenol A228.2 was added to a reactor equipped with a stirrer that was replaced with nitrogen.
9 g (1.0 mol) and 219.58 g of diphenyl carbonate (1.02
5 mol) Phenyl benzoate (5.95 g, 3 mol% based on bisphenol A) was added and melted at 160 ° C., then the catalyst was Li ₂ CO ₃ 10
^-3 mol% (relative to bisphenol A) is added to start the reaction. The temperature is gradually raised to 270 ° C. over 3 hours and the reaction system pressure is also reduced to 10 mmHg to distill off the produced phenol.
Subsequently, the reaction was carried out for 1 to 2 hours at 0.2 to 0.1 mmHg to obtain a polymer. The resulting polymer had a viscosity average molecular weight of 21,100 with little transparent coloring.

The evaluation results of the obtained polymer are shown in Tables 1 and 2.

In Examples 1 to 4 showing the contents of implementation of the present invention, 16
The retention rate of viscosity average molecular weight by the heat resistance test at 0 ° C is 94% or more in all cases. Further, the molecular weight stability by capillograph shows almost no change in the molecular weight at 280 ° C. for 1 hour, indicating that the polymer is extremely stable.

On the other hand, in the case where the end-capping agent shown in Comparative Example was not added, the retention of the molecular weight was obviously inferior, and even in the example in which 3 mol% of phenyl benzoate was used as the end-capping agent, the heat resistance was slightly improved, but the present invention It is clearly inferior to the effect.

It should be noted that the terminal-modified polycarbonate according to the present invention does not show any tendency to increase the melt viscosity in spite of its improved heat resistance when considering the molecular weight as shown in the table.

(Effects of the Invention) The polycarbonate resin obtained from the present invention has excellent heat resistance, and requires electrical insulation for electrical insulating parts, lighting parts and the like, and requires thermal insulation, greenhouses, factory buildings, sports halls, indoor hot water. Materials such as digital audio discs, video discs, memory discs, etc. of optical molding materials that can be molded at high temperatures because they have excellent heat resistance without impairing fluidity such as panels for swimming pools and other building materials. Suitable for

Claims (1)

(57) [Claims] 1. A method for producing a polycarbonate resin, which comprises using a monofunctional organic compound represented by the following general formula as a terminal terminating agent and a molecular weight modifier in the production of a polycarbonate from a dihydric phenol and a diaryl carbonate by a transesterification reaction. . General formula (In the formula, R represents hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms.)