Polycarbonate copolymer as well as preparation method and application thereof

Abstract

The present invention provides a polycarbonate copolymer having a high vicat temperature and a method for preparing the same, the polycarbonate copolymer being characterized by comprising a structural unit represented by formula (I) and a structural unit represented by formula (II), and satisfying formula (NK): S1 > = 48 (NK), wherein S1 represents the average mass content of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight-average molecular weight of 28000 or more and 5000 or less and obtained by separating the polycarbonate copolymer by gel chromatography. The polycarbonate copolymer has a high Vicat temperature and improved impact strength. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of polycarbonate, and in particular relates to a polycarbonate copolymer and a preparation method thereof. Background Art

[0002] Polycarbonate (PC) is the only transparent material among the five major engineering plastics. It has excellent mechanical properties, flame retardancy, weather resistance and electrical insulation properties. It is widely used in automobiles, electronic equipment, construction, office supplies, optical disks, sports equipment, medical care, computers, aerospace and other fields.

[0003] The copolycarbonate with 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane structure maintains the excellent performance of polycarbonate and has a higher Vicat transition temperature. It can be used in fields with special requirements for transparency and heat resistance, such as automotive lights, lamp beads, lenses, and medical devices. At the same time, due to the introduction of the 3,3,5-trimethylcyclohexane structure, its impact performance is severely reduced compared with conventional bisphenol A polycarbonate, showing brittleness, and the cantilever beam impact performance is less than 50J / m.

[0004] Therefore, it is necessary to maintain high impact strength while improving the heat resistance of bisphenol A polycarbonate. Summary of the invention

[0005] In view of the above problems existing in the prior art, the object of the present invention is to provide a polycarbonate copolymer having high Vicat temperature and high impact performance and a preparation method thereof, which can improve the quality of polycarbonate with high heat deformation temperature and broaden its application field.

[0006] The inventors have found that by controlling the mass content of the polycarbonate structure derived from bisphenol TMC in a specific weight average molecular weight range within a certain range, and controlling the ratio of the weight average molecular weight to the Z average molecular weight within a certain range, a polycarbonate copolymer having both high Vicat temperature and high impact strength can be obtained.

[0007] Based on the above findings, in order to achieve the above requirements, the technical solution of the present invention is as follows:

[0008] A polycarbonate copolymer, comprising structural units represented by formula (I) and formula (II), and satisfying formula (NK),

[0009]

[0010] S1≥48 type (NK)

[0011] Wherein S1 refers to the average mass content of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight average molecular weight of 28,000 to 50,000 obtained by separating the polycarbonate copolymer by gel chromatography, %.

[0012] Further, the polycarbonate copolymer satisfies formula (SM),

[0013] 1.1≤SM≤1.7 formula (SM)

[0014] Wherein SM is the ratio of the weight average molecular weight to the Z average molecular weight of the polycarbonate copolymer determined by gel chromatography.

[0015] In one embodiment of the present invention, the polycarbonate copolymer satisfies the following formula (NK a )

[0016] S1≥S2≥36 formula (NK a )

[0017] Wherein S2 refers to the average mass content of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight average molecular weight of not less than 15,000 and not more than 28,000 obtained by separating the polycarbonate copolymer by gel chromatography, %.

[0018] In one embodiment of the present invention, the following formula (NK) is satisfied b )

[0019] S2≥S3≥25 formula (NK b )

[0020] Wherein S3 refers to the average mass content of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight average molecular weight of 5000 to 15000 obtained by separating the polycarbonate copolymer by gel chromatography, %.

[0021] In one embodiment of the present invention, the polycarbonate copolymer satisfies the following formula (NK1):

[0022] S1 / SA>1 formula (NK1)

[0023] Wherein SA represents the average mass content of the structural unit represented by formula (II) in the polycarbonate copolymer, %.

[0024] In one embodiment of the present invention, the polycarbonate copolymer has a Vicat temperature of ≥ 180°C and an Izod impact strength of ≥ 200 J / m.

[0025] The invention also relates to a method for preparing the polycarbonate copolymer.

[0026] In one embodiment of the present invention, the preparation method is to use bisphenol A and bisphenol TMC as monomers and prepare by phosgene interfacial polycondensation. It includes the following synthesis steps:

[0027] (1) Prepolymerization: Dissolve bisphenol A and bisphenol TMC in sodium hydroxide aqueous solution respectively for later use. Add a certain amount of dissolved bisphenol A alkaline aqueous solution and bisphenol TMC alkaline aqueous solution into a reactor, and add a certain amount of phosgene and dichloromethane thereto. Preferably, the reaction temperature is 25-35°C, the reaction time is 10-60 min, and the reaction obtains a prepolymer;

[0028] (2) post-polycondensation reaction: the prepolymer prepared in step (1) is transferred to a polycondensation reactor, and a certain amount of catalyst, end-capping agent and a certain amount of sodium hydroxide aqueous solution are added to maintain the pH of the reaction system>11. Preferably, the reaction temperature is 30-35°C, the reaction time is 2-4h, and the reaction obtains a polymer solution;

[0029] (3) Post-treatment: The polymer solution obtained in step (2) is subjected to oil-water separation, followed by washing, devolatilization, pulverization and drying in sequence to obtain a powder.

[0030] In one embodiment of the present invention, in the prepolymerization stage, preferably, the amount of dichloromethane is 1.8-2.2 times the mass of pure water.

[0031] In one embodiment of the present invention, during the prepolymerization stage, the bisphenol TMC alkaline aqueous solution is added in batches, preferably 2-5 times, more preferably 3-4 times.

[0032] In one embodiment of the present invention, in the prepolymerization, the molar ratio of bisphenol A added for the first time to bisphenol TMC is 1:(0.2-0.4), preferably 1:(0.25-0.3).

[0033] In one embodiment of the present invention, in the prepolymerization, the number of times phosgene is added is the same as the number of times bisphenol TMC is added.

[0034] In one embodiment of the present invention, the total amount of phosgene added is 1.05-1.3 times, preferably 1.1-1.15 times, the total molar amount of bisphenol A and bisphenol TMC. Preferably, the first added amount of phosgene is 1.05-1.3 times, preferably 1.1-1.15 times, the total molar amount of bisphenol A and bisphenol TMC added for the first time, and the remaining phosgene is added in batches (preferably in equal amounts) together with bisphenol TMC.

[0035] In one embodiment of the present invention, the catalyst in the post-condensation is triethylamine, and the added amount is preferably 0.3%-0.35% of the total molar amount of bisphenol A and bisphenol TMC; the end-capping agent is p-tert-butylphenol.

[0036] The beneficial effects of the present invention are:

[0037] The present invention controls the mass content of the polycarbonate structure derived from bisphenol TMC in a specific weight average molecular weight range within a certain range, and at the same time controls the weight average molecular weight and the ratio of the weight average molecular weight within a certain range, so as to obtain a polycarbonate copolymer having both high Vicat temperature and high impact strength. The polycarbonate copolymer has a Vicat temperature of ≥180°C and an Izod impact strength of ≥200 J / m. DETAILED DESCRIPTION

[0038] In order to better understand the technical solution of the present invention, the content of the present invention is further described below in conjunction with the embodiments, but the content of the present invention is not limited to the following embodiments.

[0039] The main analysis and evaluation methods used in the examples and comparative examples of the present invention are as follows:

[0040] The molecular weight was measured by gel permeation chromatography (GPC) using a Waters 1515 gel permeation chromatograph with dichloromethane as the mobile phase at 30°C.

[0041] The nuclear magnetic resonance test was conducted using a Burker AVIII HD 400MHz nuclear magnetic resonance spectrometer.

[0042] The Izod impact performance is measured according to the standard test method for Izod impact performance of plastics specified in ASTM D256-1997.

[0043] The Vicat temperature test is carried out according to the plastic Vicat temperature test method specified in ISO306.

[0044] All raw materials in the embodiments and comparative examples of the present invention are common reagents purchased from commercial channels such as Aladdin Reagent Network.

[0045]

[0046] Example 1

[0047] A polycarbonate copolymer having a high Vicat temperature is prepared by:

[0048] (1) 14250 g of a 16 wt % aqueous solution of bisphenol A, 4030 g of a 20 wt % aqueous solution of bisphenol TMC and 32706 g of dichloromethane were added to a reactor and stirred into a uniform emulsion, and 1372.7 g of phosgene was added thereto at a temperature of 30° C. to start the reaction. After the reaction lasted for 20 min, 1860 g of a 20 wt % aqueous solution of bisphenol TMC and 130.4 g of phosgene were added to the reactor again. After the reaction lasted for 10 min, 1860 g of a 20 wt % aqueous solution of bisphenol TMC and 130.4 g of phosgene were added to the reactor again. The reaction lasted for 20 min to complete the prepolymerization.

[0049] (2) transferring the prepolymerized product to the final polymerization reaction, adding 151.5 g of a 3 wt % triethylamine solution and 203.57 g of a 10 wt % p-tert-butylphenol solution, and adding a 32 wt % sodium hydroxide aqueous solution, maintaining the system pH at about 12.3 and the temperature at 32° C., reacting for 2.5 h to complete the final polymerization;

[0050] (3) The product after final polymerization was washed with 20 wt% NaOH solution, washed with 0.5 mol / L hydrochloric acid, washed with deionized water, devolatilized (boiled in a 40°C glass kettle for 2 h), crushed, and dried (dried in a 120°C forced air oven for 4 h) to obtain a polycarbonate copolymer.

[0051] Example 2

[0052] (1) 14250 g of 16 wt % bisphenol A aqueous solution, 4650 g of 20 wt % bisphenol TMC aqueous solution and 33000 g of dichloromethane were added to a reactor and stirred into a uniform emulsion, and 1480.1 g of phosgene was added thereto. The temperature was 25° C. and the reaction was started. After the reaction lasted for 5 min, 1250 g of 20 wt % bisphenol TMC aqueous solution and 95 g of phosgene were added to the reactor again. After the reaction lasted for 10 min, 1250 g of 20 wt % bisphenol TMC aqueous solution and 95 g of phosgene were added to the reactor again. After the reaction lasted for 20 min, 1375 g of 20 wt % bisphenol TMC aqueous solution and 94.6 g of phosgene were added to the reactor. After the reaction lasted for 20 min, the prepolymerization was completed.

[0053] (2) transferring the prepolymerized product to the final polymerization reaction, adding 156.55 g of a 3 wt % triethylamine solution and 203.57 g of a 10 wt % p-tert-butylphenol solution, and adding a 32 wt % sodium hydroxide aqueous solution, maintaining the system pH at about 12.3 and the temperature at 33° C., reacting for 3 h to complete the final polymerization;

[0054] (3) The product after final polymerization was washed with 20 wt% NaOH solution, washed with 0.5 mol / L hydrochloric acid, washed with deionized water, devolatilized (boiled in a 40°C glass kettle for 2 h), crushed, and dried (dried in a 120°C forced air oven for 4 h) to obtain a polycarbonate copolymer.

[0055] Example 3

[0056] (1) 14250 g of a 16 wt % aqueous bisphenol A base solution, 6200 g of a 20 wt % aqueous bisphenol TMC base solution and 33500 g of dichloromethane were added to a reactor and stirred into a uniform emulsion, and 1524.6 g of phosgene was added thereto. The reaction was started at 26° C. After the reaction lasted for 10 min, 2480 g of a 20 wt % aqueous bisphenol TMC base solution and 97.1 g of phosgene were added to the reactor again, and the reaction was continued for 10 min to complete the prepolymerization;

[0057] (2) transferring the prepolymerized product to the final polymerization reaction, adding 157.56 g of a 3 wt % triethylamine solution and 203.57 g of a 10 wt % p-tert-butylphenol solution, and adding 32 wt % sodium hydroxide aqueous solution, maintaining the system pH at about 12.3 and the temperature at 31° C., reacting for 3.5 h to complete the final polymerization;

[0058] (3) The product after final polymerization was washed with 20 wt% NaOH solution, washed with 0.5 mol / L hydrochloric acid, washed with deionized water, devolatilized (boiled in a 40°C glass kettle for 2 h), crushed, and dried (dried in a 120°C forced air oven for 4 h) to obtain a polycarbonate copolymer.

[0059] Example 4

[0060] (1) 14250 g of 16 wt% aqueous bisphenol A base solution, 3100 g of 20 wt% aqueous bisphenol TMC base solution and 38500 g of dichloromethane were added to a reactor and stirred into a uniform emulsion, and 1544.4 g of phosgene was added thereto, and the temperature was 35°C, and the reaction was started for 10 minutes. 1472.5 g of 20 wt% aqueous bisphenol TMC base solution and 122.25 g of phosgene were added to the reactor again, and the reaction was continued for 10 minutes, and then the operation was repeated 3 times (i.e., bisphenol TMC and phosgene were added 5 times in total), and the prepolymerization was completed after the reaction for another 10 minutes;

[0061] (2) transferring the prepolymerized product to the final polymerization reaction, adding 157.56 g of a 3 wt % triethylamine solution and 203.57 g of a 10 wt % p-tert-butylphenol solution, and adding 32 wt % sodium hydroxide aqueous solution, maintaining the system pH at about 12.3 and the temperature at 35° C., reacting for 4 h to complete the final polymerization;

[0062] (3) The product after final polymerization was washed with 20 wt% NaOH solution, washed with 0.5 mol / L hydrochloric acid, washed with deionized water, devolatilized (boiled in a 40°C glass kettle for 2 h), crushed, and dried (dried in a 120°C forced air oven for 4 h) to obtain a polycarbonate copolymer.

[0063] Example 5

[0064] (1) 14250 g of 16 wt% aqueous bisphenol A base solution, 4340 g of 20 wt% aqueous bisphenol TMC base solution and 42702 g of dichloromethane were added to a reactor and stirred into a uniform emulsion, and 1431.9 g of phosgene was added thereto, and the temperature was 28°C to start the reaction. After 5 minutes, 4960 g of 20 wt% aqueous bisphenol TMC base solution and 358 g of phosgene were added to the reactor again, and the reaction was continued for 5 minutes to complete the prepolymerization;

[0065] (2) transferring the prepolymerized product to the final polymerization reaction, adding 188.5 g of a 3 wt % triethylamine solution and 203.57 g of a 10 wt % p-tert-butylphenol solution, and adding 32 wt % of a sodium hydroxide aqueous solution, maintaining the system pH at about 12.3 and the temperature at 30° C., reacting for 2 h to complete the final polymerization;

[0066] (3) The product after final polymerization was washed with 20 wt% NaOH solution, washed with 0.5 mol / L hydrochloric acid, washed with deionized water, devolatilized (boiled in a 40°C glass kettle for 2 h), crushed, and dried (dried in a 120°C forced air oven for 4 h) to obtain a polycarbonate copolymer.

[0067] Example 6

[0068] (1) 14250 g of a 16 wt % aqueous bisphenol A base solution, 6200 g of a 20 wt % aqueous bisphenol TMC base solution and 33560 g of dichloromethane are added to a reactor and stirred into a uniform emulsion, and 1930.5 g of phosgene is added thereto at a temperature of 30° C. to start the reaction. After reacting for 20 min, 775 g of a 20 wt % aqueous bisphenol TMC base solution and 64.35 g of phosgene are added to the reactor again. After reacting for 10 min, 775 g of a 20 wt % aqueous bisphenol TMC base solution and 64.35 g of phosgene are added to the reactor again. After reacting for 10 min, the prepolymerization is completed.

[0069] (2) transferring the prepolymerized product to the final polymerization reaction, adding 176.8 g of a 3 wt % triethylamine solution and 203.57 g of a 10 wt % p-tert-butylphenol solution, and adding a 32 wt % sodium hydroxide aqueous solution, maintaining the system pH at about 12.3 and the temperature at 32° C., reacting for 2.1 h to complete the final polymerization;

[0070] (3) The product after final polymerization was washed with 20 wt% NaOH solution, washed with 0.5 mol / L hydrochloric acid, washed with deionized water, devolatilized (boiled in a 40°C glass kettle for 2 h), crushed, and dried (dried in a 120°C forced air oven for 4 h) to obtain a polycarbonate copolymer.

[0071] Comparative Example 1

[0072] The difference between this comparative example and Example 1 is that in step (1), 7750 g of bisphenol TMC alkaline aqueous solution and 1633.5 g of phosgene are added at one time, and the reaction is carried out at 25° C. for 55 min.

[0073] Comparative Example 2

[0074] Purchase APEC18XX products from the market.

[0075] The performance test results of the polycarbonate prepared in the above embodiments and comparative examples are shown in Table 1 below:

[0076] Table 1

[0077]

[0078] From the comparison of the above data, it can be seen that the polycarbonate copolymer of the present invention has high Vicat temperature and impact strength.

[0079] Those skilled in the art will appreciate that, based on the teachings of this specification, some modifications or adjustments may be made to the present invention, and these modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A polycarbonate copolymer, characterized in that: Contains the structural units represented by formula (I) and formula (II), and satisfies formula (NK), S1≥48(NK) Wherein S1 refers to the average mass content, % of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight average molecular weight of 28,000 to 50,000 obtained by separating the polycarbonate copolymer by gel chromatography.

2. The polycarbonate copolymer according to claim 1, characterized in that The polycarbonate copolymer satisfies formula (SM), 1.1≤SM≤1.7 formula (SM) Wherein SM is the ratio of the weight average molecular weight to the Z average molecular weight of the polycarbonate copolymer determined by gel chromatography.

3. The polycarbonate copolymer according to claim 1 or 2, characterized in that: Satisfies the following formula (NK a ) S1≥S2≥36(NK a ) Wherein S2 refers to the average mass content, % of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight average molecular weight of 15,000 to 28,000 obtained by separating the polycarbonate copolymer by gel chromatography.

4. The copolycarbonate according to any one of claims 1 to 3, characterized in that Satisfies the following formula (NK b ) S2≥S3≥25(NK b ) Wherein S3 refers to the average mass content, % of the structural unit represented by formula (II) in the polycarbonate copolymer having a weight average molecular weight of 5000 to 15000 obtained by separating the polycarbonate copolymer by gel chromatography.

5. The polycarbonate copolymer according to any one of claims 1 to 4, characterized in that: Satisfies the following formula (NK1) S1 / SA>1(NK1) Wherein SA represents the average mass content of the structural unit represented by formula (II) in the polycarbonate copolymer, %.

6. The polycarbonate copolymer according to any one of claims 1 to 5, having a Vicat temperature of ≥ 180°C.

7. The polycarbonate copolymer according to any one of claims 1 to 6, having an Izod impact strength of ≥ 200 J / m.

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