Process for preparing a weatherable, solvent resistant copolycarbonate

Abstract

The application discloses a kind of weather-resistant solvent-resistant copolymer polycarbonate preparation methods, belong to copolymer polycarbonate technical field, polycarbonate copolymer is dissolved with dichloromethane in reaction kettle, functional filler is added to the reaction, after stirring ultrasonic dispersion, phosphoric acid hydrogen di (methacryloyloxy ethyl) ester is added to the reaction kettle under the irradiation of ultraviolet light, stirring is added after 2.5-3h, centrifugal filtration, filter cake is washed with anhydrous ethanol, vacuum drying, obtain weather-resistant solvent-resistant copolymer polycarbonate;The copolymer polycarbonate prepared by the method has good weather-resistant solvent-resistant performance, the functional filler containing mercapto is used as a medium, bridging flame-retardant substance and polycarbonate copolymer, without excessively affecting its transmittance, improves the flame-retardant stability of product, helps to broaden the application range of the copolymer polycarbonate product.

Description

Technical Field

[0001] The invention belongs to the technical field of copolymer polycarbonate, and particularly relates to a method for preparing weather-resistant and solvent-resistant copolymer polycarbonate. Background Art

[0002] Polycarbonate (PC) is a common engineering thermoplastic. It's a polymer composed of bisphenol A and phosgene. It contains carbonate groups and is an amorphous thermoplastic resin. Due to its high transparency and impact resistance, PC is widely used in products such as DVDs, automotive headlights, and billboards. However, conventional polycarbonate materials have poor solvent resistance, making them inapplicable in some applications. A common method involves modifying conventional polycarbonate, such as by compounding it with ABS or PBT plastics.

[0003] Chinese patent publication number CN117285809B discloses a new flame-retardant and weather-resistant polycarbonate composite material and its preparation process. By combining acrylonitrile-butadiene-styrene copolymer, modified multi-walled carbon nanotubes, and modified flame retardants, the flame retardancy and weather resistance of the polycarbonate material are enhanced. This modification method has little effect on the solvent resistance of polycarbonate. Copolycarbonates, however, are synthesized using different carbonate monomers or binary mixtures with a catalyst. For example, mixtures of polymethyl acrylate carbonate and styrene carbonate, or epoxy resin and carbonate mixtures, exhibit even better solvent resistance.

[0004] However, adding fillers such as carbon nanotubes will reduce the light transmittance of polycarbonate, and the added flame retardants will precipitate with aging, and the flame retardant performance will decrease. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing weather-resistant and solvent-resistant copolymer polycarbonate, which uses a functional filler containing a mercapto group as a medium to bridge the flame retardant material and the polycarbonate copolymer, thereby improving the flame retardant stability of the product.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing weather-resistant and solvent-resistant copolymer polycarbonate comprises the following steps:

[0008] Step 1: Add 4-(1,2,2-triphenylethylene)phenol, Sal enCoCl as a catalyst, PPNC l as a co-catalyst, allyl glycidyl ether, and silicon-containing epoxide into a reactor, stir and mix at 200-250 r / min for 5-10 minutes, then stir and react at 25-30°C and 3-3.2 MPa CO2 pressure for 16-18 hours, dissolve the reaction product in dichloromethane, transfer it to the mixed solution for precipitation, filter, and vacuum dry to obtain a polycarbonate copolymer;

[0009] Furthermore, the mixed solution is prepared by mixing anhydrous ethanol and 37% hydrochloric acid in a volume ratio of 20:1.

[0010] Furthermore, the mass ratio of 4-(1,2,2-triphenylethylene)phenol, Sal enCoCl, PPNCl, allyl glycidyl ether and silicon-containing epoxide is 3.5:6.4:5.74:91.3:467.

[0011] Step 2: Add the polycarbonate copolymer to the reactor and dissolve it in dichloromethane, add the functional filler to the reaction, stir at 200-300 r / min for 5-10 minutes, and then ultrasonically disperse for 10-15 minutes, then add the photoinitiator DMPA to the reactor, stir for 0.5-0.6 hours under ultraviolet light with an intensity of 6-8 mW / cm and a wavelength of 365 nm, then add di(methacryloyloxyethyl) hydrogen phosphate, stir the reaction for 2.5-3 hours, centrifuge and filter, wash the filter cake with anhydrous ethanol 3-5 times, and vacuum dry to obtain a weather-resistant and solvent-resistant copolymer polycarbonate.

[0012] Furthermore, the usage ratio of the polycarbonate copolymer, dichloromethane, functional filler, photoinitiator DMPA and di(methacryloyloxyethyl) hydrogen phosphate is 5.5 g: 50-60 mL: 0.33-0.44 g: 0.06-0.08 g: 0.3134 g.

[0013] Further, the silicon-containing epoxide is prepared by the following steps:

[0014] Add epichlorohydrin and sodium hydroxide to a reactor and stir at 20-25°C and 150-200 rpm for 10-15 minutes. Then, add trimethylsilanol dropwise to the reactor and stir for 2-2.5 hours. Cool and crystallize. Filter to remove salt, remove sodium chloride and unreacted sodium hydroxide, dry the filtrate with anhydrous magnesium sulfate, and fractionate under reduced pressure to obtain a silicon-containing epoxide. The reaction process is as follows:

[0015]

[0016] Furthermore, the usage ratio of epichlorohydrin, sodium hydroxide and trimethylsilanol is 92.5g:60g:90.2g.

[0017] Furthermore, the functional filler is prepared by the following steps:

[0018] Anhydrous ethanol and deionized water are added to a reactor, stirred at 35-40° C. and 800-1000 r / min for 10-15 minutes, and then tetraethoxysilane is added to the reactor, and stirring is continued for 60-80 minutes. After 25% ammonia water is added dropwise, stirring is carried out at 200-300 r / min for 5-6 hours, and then mercaptopropyltrimethoxysilane is added, stirring is carried out for 8-10 hours, and centrifugation is performed. The filter cake is washed with deionized water and anhydrous ethanol for 3-5 times respectively, vacuum dried, and crushed to obtain a functional filler.

[0019] Furthermore, the usage ratio of anhydrous ethanol, deionized water, tetraethoxysilane, ammonia water, and mercaptopropyltrimethoxysilane is 5 mL: 45 mL: 0.2 mL: 0.5 mL: 0.4 mL.

[0020] Beneficial effects of the present invention:

[0021] The copolycarbonate prepared by the method of the present invention has good weather resistance and solvent resistance. By using a functional filler containing a mercapto group as a medium to bridge the flame retardant substance and the polycarbonate copolymer, the flame retardant stability of the product is improved without excessively affecting its transmittance, which helps to broaden the application range of the copolycarbonate product.

[0022] The silicon-containing epoxide of the present invention contains methoxysilyl groups, which can enhance the solvent resistance and interfacial compatibility of the copolycarbonate, helping to improve the dispersibility of the functional filler in the polymer. During the preparation process of the functional filler, tetraethoxysilane is reacted in an ethanol-water solution in a one-step process to form nanosilica, which is then self-condensed with mercaptopropyltrimethoxysilane to obtain a functional filler with a core-shell structure. The functional filler can improve the mechanical properties of the copolycarbonate.

[0023] Allyl glycidyl ether introduces a carbon-carbon double bond into the polycarbonate copolymer. The functional filler's shell contains a thiol group, which reacts with the carbon-carbon double bond through click chemistry to connect the di(methacryloyloxyethyl) hydrogen phosphate to the polycarbonate copolymer matrix, reducing the aging migration of the phosphate flame retardant and improving flame retardant stability. 4-(1,2,2-Triphenylethylene)phenol is highly stable to UV excitation, enhancing the efficiency of the click chemistry reaction and further improving the stability of the phosphate flame retardant connection. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] Example 1: This example provides a method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate, comprising the following steps:

[0026] S1: Add 92.5 kg of epichlorohydrin and 60 kg of sodium hydroxide into a reactor, stir at 20 ° C and 150 r / min for 10 minutes, then add 90.2 kg of trimethylsilanol dropwise into the reactor, stir and react for 2 hours, cool and crystallize, filter and remove salt, remove sodium chloride and unreacted sodium hydroxide produced by the reaction, dry the filtrate with anhydrous magnesium sulfate to remove water, and perform vacuum fractionation to obtain silicon-containing epoxide.

[0027] S2: Add 50L of anhydrous ethanol and 450L of deionized water into the reactor, stir at 35°C and 800r / min for 10min, then add 2L of tetraethoxysilane into the reactor, continue stirring for 60min, dropwise add 5L of 25% ammonia water, stir at 200r / min for 5h, then add 4L of mercaptopropyltrimethoxysilane, stir and react for 8h, centrifuge and filter, wash the filter cake with deionized water and anhydrous ethanol three times respectively, vacuum dry and crush to obtain a functional filler.

[0028] S3: 3.5 kg of 4-(1,2,2-triphenylethylene)phenol, 6.4 kg of Sal enCoCl as a catalyst, 5.74 kg of PPNC l as a co-catalyst, 91.3 kg of allyl glycidyl ether and 467 kg of silicon-containing epoxide were added to a reactor, stirred at 200 r / min for 5 minutes, and then stirred and reacted at 25°C and 3 MPa CO2 pressure for 16 hours. The reaction product was dissolved in dichloromethane and transferred to a mixed solution for precipitation, filtered, and vacuum dried to obtain a polycarbonate copolymer, wherein the mixed solution was a mixture of anhydrous ethanol and 37% hydrochloric acid in a volume ratio of 20:1.

[0029] S4: Add 5.5 kg of polycarbonate copolymer into the reactor and dissolve it in 50 L of dichloromethane, add 0.33 kg of functional filler to the reaction, stir at 200 r / min for 5 minutes, and then ultrasonically disperse for 10 minutes, then add 0.06 kg of photoinitiator DMPA to the reactor, stir for 0.5 hours under ultraviolet light with an intensity of 6 mW / cm and a wavelength of 365 nm, and then add 0.3134 kg of di(methacryloyloxyethyl) hydrogen phosphate, stir and react for 2.5 hours, centrifuge and filter, wash the filter cake with anhydrous ethanol 3 times, and vacuum dry to obtain weather-resistant and solvent-resistant copolymer polycarbonate.

[0030] Example 2: This example provides a method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate, comprising the following steps:

[0031] S1: Add 92.5 kg of epichlorohydrin and 60 kg of sodium hydroxide into a reactor, stir at 22 ° C and 180 r / min for 12 minutes, then add 90.2 kg of trimethylsilanol dropwise into the reactor, stir and react for 2.2 hours, cool and crystallize, filter and remove salt, remove sodium chloride and unreacted sodium hydroxide produced by the reaction, dry the filtrate with anhydrous magnesium sulfate to remove water, and fractionate under reduced pressure to obtain silicon-containing epoxide.

[0032] S2: Add 50 L of anhydrous ethanol and 450 L of deionized water into the reactor, stir at 38°C and 900 r / min for 12 min, then add 2 L of tetraethoxysilane into the reactor, continue stirring for 70 min, add 5 L of 25% ammonia water dropwise, stir at 250 r / min for 5.5 h, then add 4 L of mercaptopropyltrimethoxysilane, stir and react for 9 h, centrifuge and filter, wash the filter cake with deionized water and anhydrous ethanol four times respectively, vacuum dry and crush to obtain a functional filler.

[0033] S3: 3.5 kg of 4-(1,2,2-triphenylethylene)phenol, 6.4 kg of Sal enCoCl as a catalyst, 5.74 kg of PPNC l as a co-catalyst, 91.3 kg of allyl glycidyl ether and 467 kg of silicon-containing epoxide were added to a reactor, stirred and mixed at 230 r / min for 8 minutes, and then stirred and reacted at 28°C and 3.1 MPa CO2 pressure for 17 hours. The reaction product was dissolved in dichloromethane and transferred to a mixed solution for precipitation, filtered, and vacuum dried to obtain a polycarbonate copolymer, wherein the mixed solution was a mixture of anhydrous ethanol and 37% hydrochloric acid in a volume ratio of 20:1.

[0034] S4: Add 5.5 kg of polycarbonate copolymer into the reactor and dissolve it in 55 L of dichloromethane, add 0.38 kg of functional filler to the reaction, stir at 250 r / min for 8 minutes, and then ultrasonically disperse for 12 minutes, then add 0.07 kg of photoinitiator DMPA to the reactor, stir for 0.55 hours under ultraviolet light with an intensity of 7 mW / cm and a wavelength of 365 nm, and then add 0.3134 kg of di(methacryloyloxyethyl) hydrogen phosphate, stir and react for 2.8 hours, centrifuge and filter, wash the filter cake with anhydrous ethanol 4 times, and vacuum dry to obtain weather-resistant and solvent-resistant copolymer polycarbonate.

[0035] Example 3: This example provides a method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate, comprising the following steps:

[0036] S1: Add 92.5 kg of epichlorohydrin and 60 kg of sodium hydroxide into a reactor, stir at 25 ° C and 200 r / min for 15 minutes, then add 90.2 kg of trimethylsilanol dropwise into the reactor, stir and react for 2.5 hours, cool and crystallize, filter and remove salt, remove sodium chloride and unreacted sodium hydroxide produced by the reaction, dry the filtrate with anhydrous magnesium sulfate to remove water, and perform vacuum fractionation to obtain silicon-containing epoxide.

[0037] S2: Add 50L of anhydrous ethanol and 450L of deionized water into the reactor, stir at 40°C and 1000r / min for 15min, then add 2L of tetraethoxysilane into the reactor, continue stirring for 80min, add 5L of 25% ammonia water dropwise, stir at 300r / min for 6h, then add 4L of mercaptopropyltrimethoxysilane, stir and react for 10h, centrifuge and filter, wash the filter cake with deionized water and anhydrous ethanol respectively for 5 times, vacuum dry and crush to obtain a functional filler.

[0038] S3: 3.5 kg of 4-(1,2,2-triphenylethylene)phenol, 6.4 kg of Sal enCoCl as a catalyst, 5.74 kg of PPNC l as a co-catalyst, 91.3 kg of allyl glycidyl ether and 467 kg of silicon-containing epoxide were added to a reactor, stirred at 250 r / min for 10 minutes, and then stirred and reacted at 30°C and 3.2 MPa CO2 pressure for 18 hours. The reaction product was dissolved in dichloromethane and transferred to a mixed solution for precipitation, filtered, and vacuum dried to obtain a polycarbonate copolymer, wherein the mixed solution was a mixture of anhydrous ethanol and 37% hydrochloric acid in a volume ratio of 20:1.

[0039] S4: Add 5.5 kg of polycarbonate copolymer into the reactor and dissolve it in 60 L of dichloromethane, add 0.44 kg of functional filler to the reaction, stir at 300 r / min for 10 minutes, and then ultrasonically disperse for 15 minutes, then add 0.08 kg of photoinitiator DMPA to the reactor, stir for 0.6 hours under ultraviolet light with an intensity of 8 mW / cm and a wavelength of 365 nm, and then add 0.3134 kg of di(methacryloyloxyethyl) hydrogen phosphate, stir and react for 3 hours, centrifuge and filter, wash the filter cake with anhydrous ethanol 5 times, and vacuum dry to obtain weather-resistant and solvent-resistant copolymer polycarbonate.

[0040] Comparative Example 1: Based on Example 3, in step S3, the silicon-containing epoxide was replaced with propylene oxide of the same molar mass, and the other steps remained unchanged to prepare a copolycarbonate.

[0041] Comparative Example 2: Based on Example 3, no functional filler was added in step S4, and the other steps remained unchanged to prepare a copolymerized polycarbonate.

[0042] Comparative Example 3: Based on Example 3, in step S4, the functional filler was replaced with ordinary nano-silica, and the other steps remained unchanged to prepare a copolymerized polycarbonate.

[0043] Comparative Example 4: Based on Example 3, a polycarbonate copolymer was prepared without adding 4-(1,2,2-triphenylethylene)phenol in step S3, and the remaining steps remained unchanged to prepare a copolymerized polycarbonate.

[0044] Comparative Example 5: Based on Example 3, di(methacryloyloxyethyl) hydrogen phosphate was not added in step S4, and the other steps remained unchanged to prepare a copolycarbonate.

[0045] The raw materials used in the examples and comparative examples were all commercially available products.

[0046] Performance tests were conducted on Examples 1-3 and Comparative Examples 1-5. Samples of different copolycarbonates were prepared according to the corresponding standards. The tensile strength and elongation at break of the different samples were tested according to GB / T 1040.2-2006. The solvent resistance of the samples was tested according to ASTM D543. Peanut oil was applied to the surface of 3.2 mm thick samples, and the appearance changes were observed and graded as A (no cracks), B (cracks), C (severe cracks), and D (breaks). The flame retardancy of 1.6 mm thick samples was tested according to UL94, with flame retardancy grades of HB, V0, V1, V2, 5VA, and 5VB. The samples were placed in a UV aging chamber and irradiated with 340 nm UV light for 800 hours. The samples were then transferred to anhydrous ethanol and immersed for 72 hours, and their flame retardancy was tested again.

[0047] The results are shown in Table 1:

[0048] Table 1

[0049]

[0050] As can be seen from Table 1, the copolycarbonates in Examples 1 to 3 have better mechanical properties, solvent resistance, light transmittance, and flame retardant properties. Comparative Example 1 shows that silicon-containing epoxide can improve the solvent resistance of the copolycarbonate, and its tensile strength and elongation at break decrease because the methoxysilyl group in the silicon-containing epoxide can improve chemical stability and improve interfacial compatibility, thereby improving the dispersibility of the functional filler; Comparative Examples 2, 3, and 5 show that the functional filler can improve the mechanical properties of the copolycarbonate, and the functional filler surface contains a thiol group, which reacts with the carbon-carbon double bond by click chemistry to connect di(methacryloyloxyethyl) hydrogen phosphate and the polycarbonate copolymer matrix, thereby reducing the aging migration of the phosphate flame retardant and improving the flame retardant stability; the flame retardant properties of the copolycarbonate after aging treatment in Comparative Example 4 decrease because 4-(1,2,2-triphenylethylene)phenol has strong stability to ultraviolet light excitation, which can improve the efficiency of the click chemistry reaction and improve the stability of the connection of the phosphate flame retardant.

[0051] It should be noted that, in this document, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0052] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate, characterized in that: The steps include: Step 1: Add 4-(1,2,2-triphenylethylene)phenol, SalenCoCl, PPNCl, allyl glycidyl ether, and silicon-containing epoxide into a reaction kettle, stir and mix at 200-250 r / min for 5-10 minutes, then stir and react at 25-30°C and 3-3.2 MPa CO2 pressure for 16-18 hours, dissolve the reaction product in dichloromethane, transfer it to the mixed solution for precipitation, filter, and vacuum dry to obtain a polycarbonate copolymer; Step 2: Add a polycarbonate copolymer to a reactor and dissolve it in dichloromethane, add a functional filler to the reaction, stir at 200-300 r / min for 5-10 minutes, and then ultrasonically disperse for 10-15 minutes, then add a photoinitiator DMPA to the reactor, stir for 0.5-0.6 hours under ultraviolet light with an intensity of 6-8 mW / cm and a wavelength of 365 nm, then add di(methacryloyloxyethyl) hydrogen phosphate, stir and react for 2.5-3 hours, centrifuge and filter, wash the filter cake with anhydrous ethanol 3-5 times, and vacuum dry to obtain a weather-resistant and solvent-resistant copolymer polycarbonate; The silicon-containing epoxide is prepared by the following steps: Add epichlorohydrin and sodium hydroxide to a reaction kettle, stir at 20-25°C and 150-200 r / min for 10-15 minutes, then add trimethylsilanol dropwise to the reaction kettle, stir and react for 2-2.5 hours, cool and crystallize, filter to remove salt, dry the filtrate with anhydrous magnesium sulfate to remove water, and fractionate under reduced pressure to obtain a silicon-containing epoxide; The functional filler is prepared by the following steps: Anhydrous ethanol and deionized water are added to a reactor, stirred at 35-40° C. and 800-1000 r / min for 10-15 minutes, and then tetraethoxysilane is added to the reactor, and stirring is continued for 60-80 minutes. After 25wt% ammonia water is added dropwise, stirring is carried out at 200-300 r / min for 5-6 hours, and then mercaptopropyltrimethoxysilane is added, and stirring is carried out for 8-10 hours. The reaction is centrifuged and filtered, and the filter cake is washed with deionized water and anhydrous ethanol for 3-5 times, respectively, vacuum dried, and crushed to obtain a functional filler.

2. The method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate according to claim 1, characterized in that: The mixed solution is prepared by mixing anhydrous ethanol and 37% hydrochloric acid in a volume ratio of 20:

1.

3. The method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate according to claim 1, characterized in that: The mass ratio of the 4-(1,2,2-tristyryl)phenol, SalenCoCl, PPNCl, allyl glycidyl ether and silicon-containing epoxide is 3.5:6.4:5.74:91.3:

467.

4. The method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate according to claim 1, characterized in that: The usage ratio of the polycarbonate copolymer, dichloromethane, functional filler, photoinitiator DMPA and di(methacryloyloxyethyl) hydrogen phosphate is 5.5 g: 50-60 mL: 0.33-0.44 g: 0.06-0.08 g: 0.3134 g.

5. The method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate according to claim 1, characterized in that: The usage ratio of epichlorohydrin, sodium hydroxide and trimethylsilanol is 92.5g:60g:90.2g.

6. The method for preparing a weather-resistant and solvent-resistant copolymer polycarbonate according to claim 1, characterized in that: The usage ratio of the anhydrous ethanol, deionized water, tetraethoxysilane, ammonia water, and mercaptopropyltrimethoxysilane is 5 mL: 45 mL: 0.2 mL: 0.5 mL: 0.4 mL.

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