CN108084425B

CN108084425B - Polycarbonate and preparation method thereof, polycarbonate composition or blend and application thereof

Info

Publication number: CN108084425B
Application number: CN201611021209.1A
Authority: CN
Inventors: 李�诚; 黄岐善
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2016-11-21
Filing date: 2016-11-21
Publication date: 2020-03-03
Anticipated expiration: 2036-11-21
Also published as: CN108084425A

Abstract

Disclosed is a polycarbonate which comprises a structural unit derived from a dihydroxy compound represented by the following formula (I),wherein R is₁Is H, halogen or C1-C6 alkyl, R₂Is C1-C4 alkylene, C6-C10 arylene or C7-C12 arylene alkyl. It has the advantages of excellent heat resistance, chemical resistance, high refractive index and the like. The invention further relates to a method for producing said polycarbonates, and to mixtures of said polycarbonates with fillers, dyes, conventional additives, thermoplastic polymers, and to finished products and uses.

Description

Polycarbonate and preparation method thereof, polycarbonate composition or blend and application thereof

Technical Field

The invention relates to a polycarbonate containing a quinoxaline structure, a preparation method thereof, a composition and a blend which are manufactured by using the polycarbonate, and application thereof.

Background

The bisphenol A polycarbonate has the advantages of high transparency, high impact strength, good heat resistance, stable size, low hygroscopicity, easy molding and the like, and is an engineering plastic with excellent comprehensive performance. However, bisphenol a polycarbonate is still insufficient in heat resistance, weather resistance, chemical resistance, refractive index and other properties in new applications such as automobile weight reduction, mobile device housings, image sensor microlenses and the like.

In the research of high performance of copolycarbonate, many studies have been made to improve the performance of one aspect, and it is difficult to improve the above-mentioned overall performance, for example:

U.S. Pat. No. 5,126,428 reports that copolycarbonate containing bisphenol TMC structure has better heat resistance, but the heat resistance stability is reduced, the weather resistance and chemical resistance are not improved, and the refractive index is reduced.

U.S. Pat. No. 4,426,514 discloses a copolycarbonate containing 4, 4' -dihydroxydiphenyl sulfide having a high refractive index, but having a reduced heat resistance and no improvement in weather resistance and chemical resistance.

U.S. Pat. No. 5,412,064 reports that copolycarbonates containing bisphenol fluorene structures have good heat resistance and high refractive index, but the refractive index is still insufficient, and the weather resistance and chemical resistance are not improved.

U.S. Pat. No. 5,530,083 reports that a copolycarbonate containing a polydimethylsiloxane structure has good weather resistance and chemical resistance, but also has reduced heat resistance and refractive index.

U.S. Pat. No. 8,445,624 reports that copolycarbonates containing isosorbide structures have improved weatherability and chemical resistance, but reduced heat resistance and refractive index.

Therefore, the prior art still needs to make a breakthrough in the polycarbonate with a novel structure, which has the advantages of comprehensive properties in the aspects of heat resistance, chemical resistance, weather resistance, high refractive index and the like.

The quinoxaline structure has high stability, can provide a series of advantages of excellent heat resistance, chemical resistance, weather resistance, high refractive index and the like, and is very beneficial to preparing high-performance polymer materials.

U.S. Pat. No. 4,797,467 discloses branched polycarbonates containing quinoxaline structures, but the quinoxaline structures are used only as branching agents and do not constitute molecular backbones for the polycarbonate, and the performance advantages of the quinoxaline structures are not shown, nor are they investigated.

Japanese patent JPH05222181A reports a series of polycarbonates with quinoxaline structure in the main chain, but mainly focuses on the application of the polycarbonates on photosensitive materials, and does not research on the improvement of other properties. In addition, the patent adopts a structural design that a benzene ring is directly connected with a quinoxaline ring, so that the polymer can absorb in a visible light region, and the polymer has a darker color. The above drawbacks will limit the application fields, especially for colorless transparent high refractive index optical materials.

Disclosure of Invention

The invention aims to provide a novel polycarbonate containing a quinoxaline structure, which has outstanding performance advantages in the aspects of heat resistance, chemical resistance, weather resistance, high refractive index and the like.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a polycarbonate comprising at least a structural unit derived from a dihydroxy compound represented by the following formula (I):

wherein R is₁Is H, halogen or C1-C6 alkyl, R₂Is a single bond, C1-C4 alkylene, C6-C10 arylene or C7-C12 arylene alkyl.

The compound containing a quinoxaline structure or a derivative thereof can be obtained by condensation reaction of a compound containing an ethylene diketone structure and o-phenylenediamine and a derivative thereof. This process is described in Chemistry of Heterocyclic Compounds, Volume5, Chemistry of Heterocyclic Compounds, Pyridazine and Pyrazine Rings (Cinnaolines, Phthalazines, and Quinoxalines), Part 3, John Wiley & Sons, Inc. And are therefore well known to researchers in the relevant field.

In the case of the structure of the general formula (I), if the above-mentioned route is employed, it is necessary to prepare the compound by reacting o-phenylenediamine and its derivative with a compound represented by the following formula (VI), which is difficult to prepare.

The preparation of the dihydroxy compound with the structure of the general formula (I) by adopting the raw material containing the quinoxaline structure in advance can avoid the difficulty in synthesis, and meanwhile, the product does not have amine residue which is easy to cause dark color, which is also beneficial to the final preparation of colorless and transparent polymers. The present invention thus provides a Williamson reaction of a quinoxaline derivative represented by the following formula (II) with an excess of a dihydroxy compound represented by the formula (III) to prepare a structure of the general formula (I). Excess dihydroxy compound is removed by solubility or differences in melting point, boiling point (references Chemistry of Heterocyclic Compounds, Volume5, Chemistry of Heterocyclic Compounds: Pyridazine and Pyrazine Rings: (Cinnaolines, Phthalazines, and Quinoxalines), Part 3, John Wiley & Sons, Inc).

HO-R₂-OH (III)

Wherein R is₁And R₂The structure of the compound is as shown in the general formula (I), and X represents halogen.

The polycarbonate of the present invention preferably contains a structural unit derived from the dihydroxy compound represented by formula (IV) from the viewpoints of the properties of the polymer to be produced and the ease of obtaining raw materials.

The polycarbonate of the present invention may further comprise, in addition to the structural units derived from the dihydroxy compound represented by formula (I), structural units derived from hydroquinone, resorcinol, one or more dihydroxy aromatic compounds represented by formula (V):

wherein R is₃Each occurrence is independently a halogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group; n and m independently represent an integer of 0 to 4; w represents a single bond, an ether bond, a thioether bond, a carbonyl group, a sulfone group, a sulfoxide group, an alkylene group having from C1 to C8, an alkylidene group having from C2 to C8, a cycloalkylene group having from C5 to C15, or a cycloalkylidene group having from C5 to C15.

Preferred dihydroxy aromatic compounds include hydroquinone, resorcinol, 4 ' -dihydroxybiphenyl, 4 ' -dihydroxydiphenyl ether, 4 ' -dihydroxydiphenyl sulfide, 1-bis (4-hydroxyphenyl) phenylethane, 2-bis (4-hydroxyphenyl) propane, 2, 2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane, 1-bis (4-hydroxyphenyl) cyclohexane, 1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1-bis (4-hydroxyphenyl) -3,3, 5-trimethylcyclohexane, 1-bis (4-hydroxyphenyl) cyclododecane, 9-bis (4-hydroxyphenyl) fluorene. Further preferred is 2, 2-bis- (4-hydroxyphenyl) propane. The dihydroxy aromatic compound may be used alone or in combination of 2 or more.

In the present invention, the molar content of the dihydroxy compound represented by formula (I) is 1 to 100 mol%, preferably 5 to 90 mol%, and more preferably 10 to 80 mol% based on the total dihydroxy compounds constituting the polycarbonate.

The polycarbonates according to the invention can be prepared by interfacial polycondensation or by melt transesterification, which are known to the person skilled in the art.

The interfacial polycondensation method of the present invention comprises the following steps: the dihydroxy compound and/or dihydroxy aromatic compound is dissolved in an aqueous alkali metal hydroxide solution to form an aqueous phase and phosgene is dissolved in an inert organic solvent to form an organic phase. The aqueous phase is mixed with the phosgene-containing organic phase to effect photochemical reactions at the interface. The blocking agent and the catalyst are added simultaneously or after the photochemical reaction to carry out the blocking and the coupling reaction is accelerated, or the blocking agent is only added to carry out the reaction. The above process may be carried out continuously or semi-continuously or batchwise.

In the process of the present invention, the alkali metal hydroxide to be used may be sodium hydroxide, potassium hydroxide or the like, and sodium hydroxide is preferred. The concentration of the dihydroxy compound and/or dihydroxy aromatic compound in the aqueous phase is 5 to 25 wt%, preferably 10 to 20 wt%. The molar ratio of the alkali metal hydroxide to the dihydroxy compound and/or the dihydroxy aromatic compound added is 2.0 to 3.0: 1, preferably 2.0 to 2.8: 1. since acid is generated during the reaction and alkali metal hydroxide is continuously consumed, a part of alkali is usually added during the reaction to maintain the reaction system alkaline.

In the method of the invention, the inert organic solvent used can be one or a mixture of more of C1-C6 chlorinated or brominated aliphatic hydrocarbon, C4-C6 chlorinated or brominated alicyclic hydrocarbon, C6-C8 aromatic hydrocarbon, C6-C8 chlorinated or brominated aromatic hydrocarbon in any weight ratio. Among them, preferred is one or a combination of any two or more of dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, toluene, chlorobenzene, and carbon tetrachloride, and more preferred is dichloromethane. The concentration of phosgene in the inert organic phase is 3-20 wt%, preferably 5-15 wt%.

In the process according to the invention, the molar ratio of dihydroxy compound and/or dihydroxy aromatic compound to phosgene is 1: 1 to 1.50, preferably 1: 1.05 to 1.25. The pressure in the reaction system may be any of reduced pressure, normal pressure and increased pressure, and the reaction can be carried out smoothly under normal pressure. The reaction temperature is-20 to 100 ℃, preferably 0 to 80 ℃, and more preferably 10 to 40 ℃. In general, the reaction system is heated with the polymerization, and therefore, water cooling or ice cooling is preferable.

In the process of the present invention, tertiary amines and/or quaternary ammonium salts may be used as the catalyst. The tertiary amine may be triethylamine, tripropylamine, tributylamine, trioctylamine, N-ethylpiperidine, N-methylpiperidine, N-isopropylpiperidine, N-N-propylpiperidine, etc. The quaternary ammonium salt may be a hydroxide, chloride, bromide, hydrogen sulfate, tetrafluoroborate, or the like of tetrabutylammonium, tributylbenzylammonium, tetraethylammonium, or the like. The catalyst is preferably a tertiary amine, and more preferably triethylamine. The catalyst is used in an amount of 0.001 to 10 mol%, preferably 0.01 to 8 mol%, more preferably 0.05 to 5 mol%, based on the molar amount of the dihydroxy compound and/or dihydroxy aromatic compound used.

The end-capping reagent used in the method of the present invention may be a monophenol compound, a chloroformate of a monophenol or an acid chloride of a monocarboxylic acid. The monophenolic compound may be phenol or an alkylphenol, preferably phenol, p-tert-butylphenol, isooctylphenol, p-cumylphenol. Adopting phenolic compound as end capping agent, and phosgene or chloroformate end group must be existed in the reaction mixture; in the case of chloroformates or acid chloride compounds as the blocking agent, sufficient terminal hydroxyl groups must be present in the reaction mixture. The blocking agent may be added at any point of time simultaneously with or after the photochemical reaction, as long as the above conditions are satisfied. The amount of the end-capping agent is 0 to 10 mol%, preferably 0.1 to 5 mol%, relative to the molar amount of the dihydroxy compound and/or dihydroxy aromatic compound used.

In the process of the invention, branching agents or mixtures of branching agents may optionally be added to the synthesis process in the same manner. The branching agent is typically added before the end-capping agent. The branching agent may be a mixture of one or more of triphenols, tetraphenols, acid chloride compounds of tricarboxylic acids, acid chloride compounds of tetracarboxylic acids. The triphenol and the tetraphenol may be phloroglucinol, 4, 6-dimethyl-2, 4, 6-tris (4-hydroxyphenyl) -2-heptene, 4, 6-dimethyl-2, 4, 6-tris (4-hydroxyphenyl) heptane, 1,3, 5-tris (4-hydroxyphenyl) benzene, 1,1, 1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) phenylmethane, 2, 4-bis (4-hydroxyphenyl isopropyl) phenol, tetrakis (4-hydroxyphenyl) methane, 3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-dihydroindole, etc. Preferred branching agents are 3, 3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2, 3-dihydroindole and 1,1, 1-tris (4-hydroxyphenyl) ethane. The amount of the branching agent to be used is preferably 0.01 to 3 mol%, more preferably 0.1 to 1 mol%, based on the dihydroxy compound and/or the dihydroxy aromatic compound.

The molecular weight of the polycarbonate prepared in the present invention is not particularly limited, and Mw (weight average molecular weight, measured by GPC after calibration with polystyrene or polycarbonate calibration substances in advance) is preferably 5000-300000, more preferably 15000-80000, and still more preferably 20000-40000.

Furthermore, it is also possible to prepare polycarbonates by melt reaction of bisphenolic compounds and/or dihydroxy aromatic compounds with diaryl carbonates, usually diphenyl carbonate, by the melt transesterification process in the presence of catalysts, for example alkali metal salts, ammonium or phosphonium compounds.

Melt transesterification is described in Encyclopedia of polymer science, volume 10 (1969), Chemistry and physics of polycarbonates, polymer reviews, H.Schnell, volume 9, John Wiley and Sons, Inc. (1964), and is therefore well known to those skilled in the art.

The obtained reaction crude product can be subjected to post-treatment by various known separation and purification methods to obtain a polycarbonate resin having a desired purity.

The polycarbonate resin of the present invention may further contain known conventional additives to constitute a polycarbonate composition. The additive components may be mold release agents, flow aids, heat stabilizers, antioxidants, UV absorbers, IR absorbers, flame retardants, antistatic agents, dyes and pigments, fillers, and the like. The additive is present in an amount of from 0.01 to 10% by weight, preferably from 0.01 to 5% by weight, more preferably from 0.02 to 2% by weight, based on the total mass of the polycarbonate composition.

The polycarbonates of the invention may be blended, optionally with other thermoplastic polymers including but not limited to bisphenol a type PC, ABS, PET, PBT, PS, PMMA and/or with conventional additives, typically glass fibers, glass spheres, carbon fibers, inorganic fillers.

The polycarbonate compositions or blends of the present invention may be prepared by means of compounding. The components are mixed in a known manner and melt-compounded and extruded at temperatures of 240 ℃ to 330 ℃ in customary equipment, such as single-screw, twin-screw extruders, and granulated by means of a granulator.

The polycarbonate of the present invention can be used in any case where known resins such as polycarbonate, polyester carbonate and polyester are used.

Preferably, the polycarbonates according to the invention or the polycarbonate compositions or blends described above can be used for the production of shaped parts of any type. Various molded articles can be produced by injection molding the pellets produced by the above-described method, or sheets, films, profile extrusion molded articles, direct blow molded articles, and injection molded articles can be produced from the resin melt-kneaded by an extruder without passing through the pellets.

Further preferred is the use of the polycarbonates according to the invention for the production of transparent or translucent or opaque or coloured injection-molded parts, extrusion-molded parts such as sheets, films, profiles, and laminates from sheets, films and the like. Based on their performance characteristics, they are particularly suitable for outdoor applications where a high degree of weathering is required, such as automotive glazing or exterior trim, lamp housings and housings for lighting fixtures, and as panels for covering in the safety and protective sector.

The formed part prepared by the polycarbonate has good comprehensive properties of heat resistance, weather resistance, chemical resistance and the like.

Detailed Description

The following examples are intended to illustrate the invention, which is not limited to the scope of the examples, but also includes any other modifications within the scope of the claims of the invention.

The raw materials used in the following examples were respectively:

bisphenol A: industrial grade, purchased from the blue star new chemical materials, inc (tin-free resin plant); sodium hydroxide: analytically pure, purchased from chemical reagents ltd of miuiou, department of Tianjin; phosgene: industrial grade, wanhua chemical group, inc; dichloromethane: analytically pure, purchased from chemical reagents ltd of miuiou, department of Tianjin; p-tert-butylphenol: analytically pure, purchased from chemical research institute of Shandong province; triethylamine: analytically pure, purchased from chemical reagents ltd of miuiou, department of Tianjin; 2, 3-dichloroquinoxaline, 2, 3-dichloro-6-methylquinoxaline, 2,3, 6-trichloroquinoxaline: purchased from Hubei Jusheng technologies, Inc.; o-diphenylamine: purchased from Hubei Jusheng technologies, Inc.; hydroquinone; purchased from national drug agents; ethylene carbonate: purchased from Baishu chemical technology, Inc.

Synthesis of the dihydroxy Compound of formula (IV)

In a 5L reaction vessel with a nitrogen inlet and mechanical stirring, 440.44g of hydroquinone, 56.11g of potassium hydroxide and 2.2L of dimethyl sulfoxide were charged, 199.04g of 2, 3-dichloroquinoxaline were slowly added to the reaction system under nitrogen atmosphere at 70 ℃ and the reaction was continued for 6 hours after the completion of the addition. After the reaction is finished, pouring the reaction solution into excessive water, filtering, collecting precipitate to obtain a crude product, and recrystallizing the crude product with ethanol to obtain a final product, wherein the yield is about 92%.

Synthesis of dihydroxy Compound represented by the following formula (VII)

440.44g of hydroquinone, 56.11g of potassium hydroxide and 2.2L of dimethyl sulfoxide were charged into a mechanically stirred 5L reaction flask with a nitrogen inlet, 213.06g of 2, 3-dichloro-6-methylquinoxaline were slowly added to the reaction system under nitrogen at 70 ℃ and the reaction was continued for 8 hours after the completion of the addition. After the reaction is finished, the reaction solution is poured into excessive water, the precipitate is collected by filtration to obtain a crude product, and the crude product is recrystallized by ethanol to obtain a final product, wherein the yield is about 85%.

Synthesis of dihydroxy Compound represented by the following formula (VIII)

440.44g of hydroquinone, 56.11g of potassium hydroxide and 2.2L of dimethyl sulfoxide are added into a mechanically stirred 5L reaction bottle with a nitrogen inlet, 233.48g of 2,3, 6-trichloroquinoxaline are slowly added into the reaction system under nitrogen atmosphere at 70 ℃, and the reaction is continued for 8 hours after the addition is finished. After the reaction is finished, the reaction solution is poured into excessive water, the precipitate is collected by filtration to obtain a crude product, and the crude product is recrystallized by ethanol to obtain a final product, wherein the yield is about 83%.

Synthesis of dihydroxy Compound represented by the following formula (IX)

Into a 5L reaction flask having a nitrogen inlet and mechanically stirred, 248.28g of ethylene glycol, 56.11g of potassium hydroxide, 2.2L of dimethyl sulfoxide were charged, 199.04g of 2, 3-dichloroquinoxaline was slowly added to the reaction system under a nitrogen atmosphere at 70 ℃ and the reaction was continued for 6 hours after the completion of the addition. After the reaction is finished, pouring the reaction solution into excessive water, filtering, collecting precipitate to obtain a crude product, and recrystallizing with ethanol to obtain a final product with the yield of about 95%.

Comparative example 1

Synthesis of homopolycarbonate from bisphenol A

456.6 bisphenol A, 3500g water and 200g sodium hydroxide are respectively added into a mixing tank, and are mixed and dissolved to form a water phase; in a separate mixing tank 217.6g of liquid phosgene and 3000g of methylene chloride were added and mixed to form an organic phase. Adding the water phase and the organic phase into a photochemical reactor formed by a static mixer at the flow rates of 41.5g/min and 32.2g/min respectively, reacting at normal temperature and normal pressure, standing for 1.5min, then feeding into a coupling reactor formed by the static mixer, simultaneously adding a dichloromethane solution with the concentration of 5 wt% of p-tert-butylphenol, a dichloromethane solution with the concentration of 1.5 wt% of triethylamine and a sodium hydroxide solution with the concentration of 30 wt% into the reactor, wherein the flow rates of the three solutions are 1.8g/min, 1.3g/min and 2.2g/min respectively, and reacting for 15 min. Separating and purifying the reaction product and removing the organic solvent to obtain the bisphenol A polycarbonate resin.

Comparative example 2

Synthesis of copolycarbonates prepared from 50 mol% bisphenol A and 50 mol% bisphenol fluorene

Respectively adding 228.3g of bisphenol A, 350.4g of bisphenol fluorene, 3500g of water, 200g of sodium hydroxide and 1000g of dichloromethane into a mixing tank, and mixing and dissolving to form a mixed solution of an aqueous phase and dichloromethane; in a separate mixing tank 217.6g of liquid phosgene and 2000g of methylene chloride were added and mixed to form an organic phase. Adding the solutions of the two mixing tanks into a photochemical reactor composed of a static mixer at the flow rates of 52.8g/min and 22.2g/min respectively, reacting at normal temperature and normal pressure, standing for 1.5min, then feeding into a coupling reactor composed of the static mixer, simultaneously adding a dichloromethane solution with the concentration of 5 wt% of p-tert-butylphenol, a dichloromethane solution with the concentration of 1.5 wt% of triethylamine and a sodium hydroxide solution with the concentration of 30 wt% into the reactor, wherein the flow rates of the three solutions are 1.8g/min, 1.3g/min and 2.2g/min respectively, and reacting for 15 min. The reaction product is separated, purified and the organic solvent is removed to obtain the bisphenol fluorene copolycarbonate.

Example 1

Synthesis of a homopolycarbonate prepared by formula (IV)

692.7g of bisphenol with the structure of formula (IV), 3500g of water and 200g of sodium hydroxide are respectively added into a mixing tank, and mixed and dissolved to form a sodium phenolate brine phase. In a separate mixing tank 217.6g of liquid phosgene and 3000g of methylene chloride were added and mixed to form an organic phase. Adding the water phase and the organic phase into a photochemical reactor formed by a static mixer at the flow rates of 43.9g/min and 32.2g/min respectively, standing for 1.5min, then feeding into a coupling reactor formed by the static mixer, reacting at normal temperature and normal pressure, simultaneously adding a dichloromethane solution with the concentration of 5 wt% of p-tert-butylphenol, a dichloromethane solution with the concentration of 1.5 wt% of triethylamine and a sodium hydroxide solution with the concentration of 30 wt% into the reactor, wherein the flow rates of the three solutions are 1.8g/min, 1.3g/min and 2.2g/min respectively, and reacting for 15 min. And (3) separating the reaction crude product to remove a water phase, washing, separating and purifying an organic phase, and removing a dichloromethane solvent to obtain colorless polycarbonate resin with the number of A-1.

Example 2

Synthesis of a copolycarbonate prepared from 90 mol% of a bisphenol of formula (IV) and 10 mol% of bisphenol A

623.4g of bisphenol with a structure of formula (IV), 45.6g of bisphenol A, 3500g of water and 200g of sodium hydroxide are respectively added into a mixing tank, and mixed and dissolved to form a sodium phenolate brine phase. The aqueous phase was fed at a rate of 43.7g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was designated as No. A-2.

Example 3

Synthesis of a copolycarbonate prepared from 80 mol% of a bisphenol of formula (IV) and 20 mol% of bisphenol A

554.1g of bisphenol with the structure of formula (IV), 91.3g of bisphenol A, 3500g of water and 200g of sodium hydroxide are respectively added into a mixing tank, and mixed and dissolved to form a sodium phenolate brine phase. The aqueous phase was fed at a rate of 43.4g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was designated as No. A-3.

Example 4

Synthesis of a copolycarbonate prepared from 50 mol% of a bisphenol of formula (IV) and 50 mol% of bisphenol A

346.3g of bisphenol with a structure of formula (III), 228.3g of bisphenol A, 3500g of water and 200g of sodium hydroxide are respectively added into a mixing tank, and mixed and dissolved to form a sodium phenolate brine phase. The aqueous phase was fed at a rate of 42.7g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was designated as No. A-4.

Example 5

Synthesis of a copolycarbonate prepared from 10 mol% of a bisphenol of formula (IV) and 90 mol% of bisphenol A

69.27g of bisphenol having the structure of formula (IV), 410.9g of bisphenol A, 3500g of water and 200g of sodium hydroxide were added to a mixing tank, and mixed and dissolved to form a sodium phenolate aqueous phase. The aqueous phase was fed at a rate of 41.8g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was designated as No. A-5.

Example 6

Synthesis of a copolycarbonate prepared from 5 mol% of a bisphenol of formula (IV) and 95 mol% of bisphenol A

34.6g of bisphenol having a structure of formula (IV), 433.7g of bisphenol A, 3500g of water and 200g of sodium hydroxide were added to a mixing tank, and mixed and dissolved to form a sodium phenolate aqueous phase. The aqueous phase was fed at a rate of 41.7g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was designated as No. A-6.

Example 7

Synthesis of a copolycarbonate prepared from 50 mol% bisphenol of formula (VII) and 50 mol% bisphenol A

360.4g of bisphenol having a structure of formula (VII), 228.3g of bisphenol A, 3500g of water and 200g of sodium hydroxide were added to a mixing tank, and mixed and dissolved to form a sodium phenolate aqueous phase. The aqueous phase was fed at a rate of 42.9g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was numbered B.

Example 8

Synthesis of a copolycarbonate prepared from 50 mol% of a bisphenol of formula (VIII) and 50 mol% of bisphenol A

380.8g of bisphenol with the structure of formula (VIII), 228.3g of bisphenol A, 3500g of water and 200g of sodium hydroxide are respectively added into a mixing tank, and mixed and dissolved to form a sodium phenolate brine phase. The aqueous phase was fed at a rate of 43.1g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained was numbered C.

Example 9

Synthesis of a copolycarbonate prepared from 50 mol% of a bisphenol of formula (XI) and 50 mol% of bisphenol A

250.3g of bisphenol having the structure of formula (XI), 228.3g of bisphenol A, 3500g of water and 200g of sodium hydroxide were added to a mixing tank, and mixed and dissolved to form a sodium phenolate brine phase. The aqueous phase was fed at a rate of 43.1g/min into the photochemical reactor constituted by a static mixer, and the other steps were the same as in example 1. The colorless polycarbonate resin obtained is numbered D.

Example 10

Polycarbonate blends prepared from 50 wt% of A-1 polycarbonate and 50 wt% of bisphenol A type homopolycarbonate

50 parts by weight of the polycarbonate of type A-1 obtained in example 1 and 50 parts by weight of the bisphenol A homopolycarbonate obtained in comparative example 1 were mixed by means of a high-speed mixer for about 10 min. The mixture was then extruded using a 25mm co-rotating twin screw extruder with a barrel operating temperature of 240 ℃ and 280 ℃. The colorless polycarbonate resin obtained is numbered E.

The heat resistance of polycarbonate resins was evaluated by means of the glass transition temperature Tg, measured by dynamic differential thermal analysis (DSC) according to ASTM E1356.

The weathering resistance of the resins was evaluated by the UV ageing test, in which the resins were injection-molded into 9cm by 9cm square pieces using an injection-molding machine and aged in a UV lamp ageing oven under test conditions according to the standard ASTM D4329. After aging for 500h, the delta YI of the sample wafer before and after the test was measured.

The chemical resistance was evaluated by the environmental stress failure resistance method, with the test procedure according to standard ISO 22088-3, the resin samples were soaked with solvents 10% NaOH, 10% acetic acid, ethanol, 5% ammonia for 24h, and then the samples were subjected to the flexural strength test, according to ISO 178.

The refractive index n was measured by an Abbe refractometer using a 589nm wavelength polycarbonate film obtained by dissolving a polycarbonate resin in methylene chloride to prepare a 15 wt% solution, followed by spin coating, and the thickness was 100. mu.m.

The results of the characterization of the Tg, the YI after aging and the refractive index n for the comparative examples and the examples are shown in Table 1 below, and the results of the environmental stress crack resistance evaluation for the comparative examples and the examples for different solvents are shown in Table 2 below.

TABLE 1 comparison of Heat resistance, weather resistance and refractive index

	Tg(℃)	ΔYI	n(589nm)
				Comparative example 1	147	15.2	1.586
Comparative example 2	201	19.3	1.618
				A-1	261	8.8	1.702
A-2	250	9.4	1.690
				A-3	239	10.1	1.678
A-4	206	12.2	1.644
				A-5	160	14.6	1.597
A-6	153	14.9	1.592
				B	213	10.9	1.641
C	215	11.2	1.649
				D	208	9.3	1.626
E	205	10.6	1.645

Table 2 bending strength test results after solvent immersion

The evaluation results show that the copolycarbonates of the present invention have improved heat resistance, aging resistance, chemical resistance, and high refractive index, relative to conventional bisphenol A type carbonates. The copolycarbonates of the invention (e.g., A-4, B, C, D) also have more outstanding properties relative to bisphenol fluorene copolycarbonate at the same 50 mol% comonomer content.

Claims

1. A polycarbonate comprising a structural unit derived from a dihydroxy compound represented by formula (I),

wherein R is₁Is H, halogen or C1-C6 alkyl, R₂Is C1-C4 alkylene, C6-C10 arylene or C7-C12 arylene alkyl;

the compound with the structure of the general formula (I) is obtained by reacting quinoxaline derivatives shown in a formula (II) with excessive dihydroxy compounds shown in a formula (III),

HO-R₂-OH (III)

wherein R is₁Is H, halogen or C1-C6 alkyl, R₂Is C1-C4 alkylene, C6-C10 arylene or C7-C12 arylene alkyl, and X represents halogen.

2. The polycarbonate according to claim 1, wherein the polycarbonate comprises a structural unit derived from a dihydroxy compound represented by formula (IV),

3. the polycarbonate of claim 1, further comprising structural units derived from hydroquinone, resorcinol, and at least one dihydroxy aromatic compound represented by formula (V),

wherein R is₃Independently at each occurrenceIs a halogen atom, an alkyl group of C1-C6 or an alkoxy group of C1-C6; n and m independently represent an integer of 0 to 4; w represents a single bond, an ether bond, a thioether bond, a carbonyl group, a sulfone group, a sulfoxide group, an alkylene group having from C1 to C8, an alkylidene group having from C2 to C8, a cycloalkylene group having from C5 to C15, or a cycloalkylidene group having from C5 to C15.

4. The polycarbonate of claim 3, wherein the dihydroxy aromatic compound comprises hydroquinone, resorcinol, 4 ' -dihydroxybiphenyl, 4 ' -dihydroxydiphenyl ether, 4 ' -dihydroxydiphenyl sulfide, 1-bis (4-hydroxyphenyl) phenylethane, 2-bis (4-hydroxyphenyl) propane, 2-bis (3, 5-dimethyl-4-hydroxyphenyl) propane, 1-bis (4-hydroxyphenyl) cyclohexane, 1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1-bis (4-hydroxyphenyl) -3,3, 5-trimethylcyclohexane, 1-bis (4-hydroxyphenyl) cyclododecane, a diol, 9, 9-bis (4-hydroxyphenyl) fluorene.

5. The polycarbonate according to any one of claims 1 to 4, wherein the dihydroxy compound represented by formula (I) is contained in an amount of 1 to 100 mol% based on the total dihydroxy compounds constituting the polycarbonate.

6. The polycarbonate according to claim 5, wherein the dihydroxy compound represented by formula (I) is contained in an amount of 5 to 90 mol% based on the total dihydroxy compounds constituting the polycarbonate.

7. The polycarbonate according to claim 6, wherein the dihydroxy compound represented by formula (I) is contained in an amount of 10 to 80 mol% based on the total dihydroxy compounds constituting the polycarbonate.

8. A method for preparing the polycarbonate of any of claims 1-7, wherein the method is an interfacial phosgene method or a melt transesterification method.

9. A polycarbonate composition, characterized in that it comprises, in addition to the polycarbonate according to any of claims 1 to 7, from 0.01 to 10% by weight, based on the total mass of the polycarbonate composition, of one or more of the following components: mold release agents, flow aids, heat stabilizers, antioxidants, UV absorbers, IR absorbers, flame retardants, antistatic agents, dyes and pigments, fillers.

10. A blend of a polycarbonate according to any of claims 1 to 7 or obtained by the preparation process according to claim 8 with a thermoplastic polymer.

11. Use of the polycarbonate according to any of claims 1 to 7 or the polycarbonate composition according to claim 9 or the blend according to claim 10 for the preparation of transparent or translucent or opaque shaped parts, extrudates, laminates.