Curable carbonate composition, preparation method therefor, and cured carbonate

Abstract

The invention provides a curable carbonate composition. The curable carbonate composition comprises a carbonate epoxy copolymer, a solvent, a first catalyst, a second catalyst and an epoxy component. The carbonic ester epoxy copolymer has a structure shown as a formula (I), # imgabs0 #, so that the mixing uniformity and the solvent solubility in the curing process can be improved, the process steps can be simplified, and the energy consumption and the generation of byproducts in the curing process can be reduced.

Description

Technical Field

[0001] The present invention relates to a curable carbonate composition, a preparation method thereof, and a carbonate cured product, and particularly to a curable carbonate composition containing a carbonate epoxy copolymer, which has good storage stability and the carbonate cured product has good material properties. Background Art

[0002] Polycarbonate (PC) is a thermoplastic polymer material formed by the transesterification reaction of materials such as bisphenol A and diphenyl carbonate at high temperature. Polycarbonate belongs to one of the five major engineering plastic materials, and it has good transparency, impact resistance, and heat resistance, so it is widely used in consumer products such as spectacle lenses, optical discs, data storage devices, or automotive lamp covers.

[0003] When the aromatic carbonate structure and the epoxy structure are catalyzed by a Benzyldimethylamine (BDMA) catalyst at high temperature, a transesterification reaction will occur. The aromatic carbonate structure will be replaced by an aliphatic carbonate structure, and at the same time, a cyclization side reaction will occur to form an ethylene carbonate structure. The said cyclization side reaction will break the molecular chain of the cured product and damage the integrity of the network structure of the cured product. Therefore, if one wants to prepare a cured product with high heat resistance using a carbonate structure and an epoxy structure, the problems brought about by the cyclization side reaction must be overcome first.

[0004] Furthermore, if a diphenol monomer with a more complex chemical structure than bisphenol A is used as a raw material to synthesize a carbonate oligomer, the obtained product can be melt-mixed with an epoxy resin and cured at high temperature. Compared with the carbonate oligomer prepared using bisphenol A as a raw material, the cured product obtained using a diphenol monomer as a raw material has better heat resistance. However, the disadvantage of this synthesis method is that the carbonate oligomer must be synthesized from monomers, and it must be synthesized at a high temperature above 200 °C, and by-products phenol must be separated by vacuum distillation, resulting in a large amount of energy consumption.

[0005] In addition, if waste polycarbonate is directly used as a hardener for epoxy resin, the cured product after curing and molding has high heat resistance and degradability. After the cured product degrades, a high molecular weight phenoxy resin can be obtained, which can be used as a chemical additive and applied in other fields such as coatings, providing a more environmentally friendly and beneficial treatment solution for waste polycarbonate. However, the disadvantage of the above treatment solution is that the melting point of waste polycarbonate is too high, making it difficult to directly melt-mix with epoxy resin at high temperature, and because the molecular weight of waste polycarbonate is too large, its solubility in organic solvents is poor. Therefore, the solid content of the waste polycarbonate solution can only reach 10 wt% to 30 wt%, which causes great limitations in practical applications.

[0006] It can be seen from this that in the currently known technologies, carbonate oligomers must be obtained by polymerizing monomers, and the problems of energy consumption in high-temperature processes and the treatment of by-products still remain difficult problems to be overcome. Moreover, although carbonate oligomers and epoxy resins can be co-cured, there are still quite deficiencies in the mixing uniformity, solvent solubility, or storage stability during the curing process. Summary of the Invention

[0007] An object of the present invention is to provide a curable carbonate composition, the cured product of which can maintain good heat resistance, and can further solve problems such as high energy consumption and by-products in the process, and at the same time improve properties such as mixing uniformity, solvent solubility, or storage stability in the process.

[0008] An embodiment of the present invention provides a curable carbonate composition, which comprises a carbonate epoxy copolymer, a solvent, a first catalyst, a second catalyst, and an epoxy component. The carbonate epoxy copolymer has a structure as shown in formula (I):

[0009]

[0010] wherein, R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, an alkoxy group having 1 to 6 carbon atoms, an aromatic group having 6 to 12 carbon atoms, or a halogen atom, a and b are each independently an integer from 0 to 4, and n is an integer from 7 to 24, Y is a chemical structure having at least one epoxy group, and X and Z are each independently a single bond, a structure as shown in formula (1), formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), or formula (11):

[0011]

[0012]

[0013] wherein, X1 and X2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms. The solvent is selected from the group consisting of N,N-dimethylacetamide, N-methylpyrrolidone, dimethylformamide, anisole, dimethyl sulfoxide, propylene glycol methyl ether acetate, propylene glycol methyl ether propionate, and cyclohexanone. The first catalyst is selected from the group consisting of 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, imidazole compounds, pyridine compounds, tertiary amine compounds, and quaternary ammonium salts. The second catalyst is selected from the group consisting of triphenylphosphine, triphenylphosphine chloride derivatives, triphenylphosphine bromide derivatives, triphenylphosphine iodide derivatives, and quaternary ammonium salts.

[0014] Accordingly, the curable carbonate composition of the present invention has characteristics such as a high solid content and high storage stability, can improve the mixing uniformity and solvent solubility during the curing process, can further simplify the process steps, reduce the energy consumption and by-product generation during the curing process, and the cured product can have good heat resistance, which is beneficial to be used as the basic formulation of an epoxy varnish.

[0015] Another embodiment of the present invention provides a method for preparing the aforementioned curable carbonate composition, which includes the following steps. Perform an alcoholysis reaction step, where a polycarbonate and a first component are added to a solvent, and the temperature is raised to a first heating temperature for stirring. After the polycarbonate and the first component are dissolved, a first catalyst is added and the reaction is carried out while maintaining the first heating temperature to form a first mixture, and the first mixture contains a carbonate oligomer, where the first component has a structure as shown in formula (i), and the carbonate oligomer has a structure as shown in formula (ii):

[0016]

[0017] Perform a mixing step, where a second component is added to the first mixture, and the mixture is stirred while maintaining a second heating temperature to form a second mixture, where the second component has at least two epoxy groups. Perform a pre-reaction step, where a second catalyst is added to the second mixture, and the mixture is stirred while maintaining a third heating temperature to form a curable carbonate composition.

[0018] According to the aforementioned preparation method, the number average molecular weight of the first mixture can be 1000 g / mole to 5000 g / mole.

[0019] According to the aforementioned preparation method, the molar ratio of the first component to the polycarbonate can be 6 to 20.

[0020] According to the aforementioned preparation method, the addition amount of the first catalyst can be 0.1 mole percentage to 1.0 mole percentage of the content of the first component in the first mixture.

[0021] According to the aforementioned preparation method, the first heating temperature can be 110°C to 170°C.

[0022] According to the aforementioned preparation method, the second component can include at least one epoxy compound, the at least one epoxy compound has at least two epoxy groups, and when the number of epoxy compounds is two or more, each epoxy compound can have a different chemical structure.

[0023] According to the aforementioned preparation method, the addition amount of the second component can be 15 weight percentage to 65 weight percentage of the total amount of the second mixture.

[0024] According to the foregoing preparation method, the addition amount of the second component can be 25% by weight to 50% by weight of the total amount of the second mixture.

[0025] According to the foregoing preparation method, the second heating temperature can be 60°C to 150°C.

[0026] According to the foregoing preparation method, the third heating temperature can be 130°C to 160°C.

[0027] According to the foregoing preparation method, the addition amount of the second catalyst can be 0.05% by weight to 1.50% by weight of the content of the second component in the second mixture.

[0028] According to the foregoing preparation method, the solid content of the curable carbonate composition can be 40% by weight to 80% by weight.

[0029] Another embodiment of the present invention provides a cured carbonate, which is obtained by adding a promoter to the foregoing curable carbonate composition and reacting it at a curing temperature after heating.

[0030] According to the foregoing cured carbonate, the promoter can be selected from a group consisting of 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, imidazole compounds, pyridine compounds, and tertiary amine compounds.

[0031] According to the foregoing cured carbonate, the addition amount of the promoter can be 0.05% by weight to 1.50% by weight of the total amount of the curable carbonate composition.

[0032] According to the foregoing cured carbonate, the curing temperature can be 150°C to 240°C. Description of the Drawings

[0033] To make the above and other objects, features, advantages, and embodiments of the present invention more obvious and understandable, the description of the accompanying drawings is as follows:

[0034] Figure 1 It is a flowchart of the steps of the preparation method of the curable carbonate composition of the present invention.

[0035]

Symbol Explanation

[0036] 100: Preparation method

[0037] 110, 120, 130: Steps

[0038] f1, f2, f3, f4, c1, c2, c3, c4: Curable carbonate composition

[0039] C-f1, C-f2, C-f3, C-f4, C-c1, C-c2, C-c3, C-c4: Carbonate cured products DETAILED DESCRIPTION

[0040] The following will discuss various embodiments of the present invention in more detail. However, this embodiment can be an application of various inventive concepts and can be specifically implemented in various specific scopes. The specific embodiments are for illustrative purposes only and are not limited to the scope of the disclosure.

[0041] In the present invention, the compound structure is sometimes represented by a skeleton formula, which may omit carbon atoms, hydrogen atoms, and carbon-hydrogen bonds. If the functional group is clearly drawn in the structural formula, the drawn one shall prevail.

[0042] In the present invention, for the sake of simplicity and fluency, "the first component has a structure as shown in formula (i)" is sometimes expressed as "the first component as shown in formula (i)" or "first component (i)", and the representation of other compounds or groups is similar.

[0043] <Curable Carbonate Composition>

[0044] One embodiment of the present invention provides a curable carbonate composition, which includes a carbonate epoxy copolymer, a solvent, a first catalyst, a second catalyst and an epoxy component. The carbonate epoxy copolymer has a structure as shown in formula (I):

[0045]

[0046] wherein R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, an alkoxy group having 1 to 6 carbon atoms, an aromatic group having 6 to 12 carbon atoms, or a halogen atom; a and b are each independently an integer from 0 to 4; n represents a degree of polymerization, which is an integer from 7 to 24; Y is a chemical structure having at least one epoxy group; X and Z are each independently a single bond, a structure represented by formula (1), formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10) or formula (11):

[0047]

[0048] Wherein, X1 and X2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms. In addition, the aforementioned solvent, the first catalyst, the second catalyst, and the epoxy component will be described in subsequent paragraphs and will not be repeated here.

[0049] <Preparation method of curable carbonate composition>

[0050] Please refer to Figure 1 , Figure 1 which is the flowchart of step 100 of the preparation method of the curable carbonate composition of the present invention for preparing the aforementioned curable carbonate composition. The preparation method 100 of the curable carbonate composition includes step 110, step 120 and step 130.

[0051] Step 110 is to carry out an alcoholysis reaction step, in which a polycarbonate and a first component are added to a solvent, and the temperature is raised to a first heating temperature for stirring. After the polycarbonate and the first component are dissolved, a first catalyst is added and the reaction is carried out at the first heating temperature to form a first mixture, and the first mixture contains a carbonate oligomer, wherein the first component has a structure shown in formula (i), and the carbonate oligomer has a structure shown in formula (ii):

[0052]

[0053] The molar ratio of the first component to the polycarbonate can be 6 to 20, wherein the molar number of the polycarbonate is calculated based on its number average molecular weight (Mn). The solvent can be selected from the group consisting of N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), anisole, dimethyl sulfoxide (DMSO), propylene glycol methyl ether acetate, propylene glycol methyl ether propionate and cyclohexanone. The first heating temperature can be 110 °C to 170 °C.

[0054] The addition amount of the first catalyst can be 0.1 mol% to 1.0 mol% of the content of the first component in the first mixture. The first catalyst can be selected from the group consisting of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), imidazole compounds, pyridine compounds, tertiary amine compounds and quaternary amine salts.

[0055] The number average molecular weight of the first mixture can be from 1000 g / mole to 5000 g / mole, preferably from 2000 g / mole to 4000 g / mole.

[0056] Step 120 is to perform a mixing step of adding a second component to the first mixture and stirring it at a second heating temperature to form a second mixture, where the second component has at least two epoxy groups.

[0057] The second component may include at least one epoxy compound. The epoxy compound has at least two epoxy groups. When the number of epoxy compounds is more than two, each epoxy compound may have a different chemical structure. For example, it may be an epoxy compound with multiple epoxy groups combined with an epoxy compound with two epoxy groups, an epoxy compound with two epoxy groups combined with an epoxy compound with two epoxy groups, an epoxy compound with multiple epoxy groups combined with an epoxy compound with multiple epoxy groups, or other epoxy compounds in combination. The present invention is not limited to the combinations listed above. The epoxy compound may be bisphenol A type epoxy resin, phenolic multi-functional epoxy resin, or other types of epoxy resins. The addition amount of the second component may be 15 weight percent to 65 weight percent of the total amount of the second mixture, preferably 25 weight percent to 50 weight percent of the total amount of the second mixture. The second heating temperature may be 60°C to 150°C.

[0058] Step 130 is to perform a pre-reaction step of adding a second catalyst to the second mixture and stirring it at a third heating temperature to form a curable carbonate composition, where the solid content of the curable carbonate composition may be 40 weight percent to 80 weight percent, and the solid content is the weight ratio of the curable carbonate composition before and after removing the solvent.

[0059] The third heating temperature may be 130°C to 160°C. The second catalyst may be selected from the group consisting of triphenylphosphine, triphenylphosphine chloride derivatives, triphenylphosphine bromide derivatives, triphenylphosphine iodide derivatives, and quaternary ammonium salts. The addition amount of the second catalyst may be 0.05 weight percent to 1.50 weight percent of the content of the second component in the second mixture.

[0060] It should be particularly noted that the aforementioned preparation method 100 can obtain the curable carbonate composition of the present embodiment without purification after the reaction is completed. Therefore, the curable carbonate composition can be directly used in subsequent applications without purification, thereby improving the convenience in application and reducing the manufacturing cost.

[0061] <Carbonate cured product>

[0062] Another embodiment of the present invention provides a carbonate cured product, which is obtained by adding a promoter to the aforementioned curable carbonate composition and then heating it to a curing temperature for reaction.

[0063] The promoter can be selected from a group consisting of 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, imidazole compounds, pyridine compounds, and tertiary amine compounds. The addition amount of the promoter can be 0.05 wt% to 1.50 wt% of the total amount of the curable carbonate composition. The curing temperature can be 150°C to 240°C.

[0064] The following specific examples further demonstrate the present invention, which is beneficial for those with ordinary knowledge in the technical field to which the present invention belongs to fully utilize and practice the present invention without excessive interpretation. These examples should not be regarded as limiting the scope of the present invention, but are used to illustrate the materials and methods for implementing the present invention.

[0065] <Preparation of Curable Carbonate Composition>

[0066] <Example 1>

[0067] Take 100 grams (5×10 -3 mole) of recycled polycarbonate powder (purchased from Jiuxuan Technology Co., Ltd., product code RPC-y) and 12.35 grams of bisphenol A (5.5×10 -2 mole), add 100 grams of cyclohexanone solvent, heat to 150°C and maintain the temperature while stirring, then add 0.016 grams (0.2 mol% of bisphenol A) of 1,8-diazabicyclo[5.4.0]undec-7-ene, and react for 6 hours to form a first mixture. The first mixture contains carbonate oligomers, and the carbonate oligomers have a structure shown in formula (ii-a):

[0068]

[0069] After the first mixture is cooled, add 150.39 grams of bisphenol A type epoxy resin (Diglycidyl ether of bisphenol A; DGEBA), and heat and stir at 140°C to form a second mixture. Then add 1.2 grams of triphenylphosphine (0.8 wt% of the epoxy resin), and pre-react at 140°C for 2.5 hours to obtain a curable carbonate composition f1, which contains a carbonate epoxy copolymer shown in formula (I-a), and the solution of the curable carbonate composition f1 is clear and light yellow:

[0070]

[0071] Specifically, the number average molecular weight of the recycled polycarbonate crushed material RPC-y is 18,491, and the weight average molecular weight is 40,990. After the first mixture of Example 1 was measured by a gel permeation chromatograph (GPC), its number average molecular weight was 2,872, and the weight average molecular weight was 5,490.

[0072] <Example 2>

[0073] The preparation method of the first mixture of Example 2 is the same as that of Example 1, except that the subsequent process is changed to: after the first mixture is cooled, 172.51 g of a phenolic polyfunctional epoxy resin (purchased from Changchun Group, product code CNE-195) is added, and the mixture is heated and stirred at 120 °C to form a second mixture. Then, 1.38 g of triphenylphosphine (0.8 wt% of the epoxy resin) is added, and the mixture is pre-reacted at 140 °C for 2.5 hours to obtain a curable carbonate composition f2, which contains a carbonate epoxy copolymer as shown in formula (I-b), and the solution of the curable carbonate composition f2 is clear and light yellow:

[0074]

[0075] Specifically, after the first mixture of Example 2 was measured by a gel permeation chromatograph, its number average molecular weight was 2,585, and the weight average molecular weight was 5,351.

[0076] <Example 3>

[0077] The preparation method of the first mixture of Example 3 is the same as that of Example 1, except that the subsequent process is changed to: after the first mixture is cooled, 101.73 g of 4,4'-methylenebis(N,N-diglycidylaniline) (TGDDM) is added, and the mixture is heated and stirred at 120 °C to form a second mixture. Then, 0.81 g of triphenylphosphine (0.8 wt% of the epoxy resin) is added, and the mixture is pre-reacted at 140 °C for 4 hours to obtain a curable carbonate composition f3, which contains a carbonate epoxy copolymer as shown in formula (I-c), and the solution of the curable carbonate composition f3 is clear and orange-red:

[0078]

[0079] Specifically, after the first mixture of Example 3 was measured by a gel permeation chromatograph, its number average molecular weight was 2,378, and the weight average molecular weight was 4,883.

[0080] <Example 4>

[0081] The preparation method of Example 4 is the same as that of Example 1, except that the amount of bisphenol A is changed to 8.64 g (3.8×10 - 2 mole). Finally, a curable carbonate composition f4 can be obtained, which contains a carbonate epoxy copolymer represented by formula (I-a), and the solution of the curable carbonate composition f4 is clear and light yellow. Among them, after the first mixture of Example 4 is measured by a gel permeation chromatograph, its number average molecular weight is 3238 and its weight average molecular weight is 6877.

[0082] <Comparative Example 1>

[0083] Take 100 g (5×10 -3 mole) of recycled polycarbonate powder RPC-y and 10.61 g of furfuryl alcohol (1.08×10 -1 mole), add 100 g of cyclohexanone solvent, heat to 150 °C and then maintain the temperature and stir. Then add 0.032 g (0.2 mol% of furfuryl alcohol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, and react for 6 hours to form a first mixture. The first mixture contains a carbonate oligomer, and the carbonate oligomer has a structure represented by formula (C-1):

[0084]

[0085] After the first mixture is cooled, 148.06 g of bisphenol A type epoxy resin is added, and the mixture is heated and stirred at 110 °C to form a second mixture. Then add 1.2 g of triphenylphosphine (0.8 wt% of epoxy resin), and pre-react at 140 °C for 5 hours to obtain a curable carbonate composition c1.

[0086] Specifically, after the first mixture of Comparative Example 1 is measured by a gel permeation chromatograph, its number average molecular weight is 2847 and its weight average molecular weight is 5481.

[0087] <Comparative Example 2>

[0088] The preparation method of Comparative Example 2 is the same as that of Example 1, except that triphenylphosphine is replaced by 2-phenylimidazole, the amount used is 0.6 g (0.4 wt% of epoxy resin), and the pre-reaction temperature is replaced by 100 °C, to obtain a curable carbonate composition c2, and the solution of the curable carbonate composition c2 is clear and reddish-brown.

[0089] Specifically, after the first mixture of Comparative Example 2 is measured by a gel permeation chromatograph, its number average molecular weight is 2687 and its weight average molecular weight is 5307.

[0090] <Comparative Example 3>

[0091] The preparation method of Comparative Example 3 was the same as that of Comparative Example 2, except that the amount of 2-phenylimidazole was changed to 0.15 g (0.1 wt% of the epoxy resin), and a curable carbonate composition c3 could be obtained, and the solution of the curable carbonate composition c3 was a clear reddish-brown color.

[0092] Specifically, after the first mixture of Comparative Example 3 was measured by a gel permeation chromatograph, its number average molecular weight was 2,817 and its weight average molecular weight was 5,421.

[0093] <Comparative Example 4>

[0094] The preparation method of Comparative Example 4 was the same as that of Example 1, except that the amount of bisphenol A was changed to 6.17 g (2.7×10 - 2 mole). After the first mixture obtained in Comparative Example 4 was measured by a gel permeation chromatograph, its number average molecular weight was 5,559 and its weight average molecular weight was 9,729, and many floating insoluble substances appeared in the subsequent process, resulting in the inability to smoothly obtain the final composition.

[0095] <Comparative Example 5>

[0096] Take 100 g (5×10 -3 mole) of recycled polycarbonate crushed material RPC-y and 16.23 g of p-tert-butylphenol (PTBP; 1.08×10 -1 mole), add 100 g of cyclohexanone solvent, heat to 150 °C and maintain the temperature and stir, then add 0.032 g (0.2 mol% of p-tert-butylbenzene) of 1,8-diazabicyclo[5.4.0]undec-7-ene, and react for 6 hours to form a first mixture. The first mixture contains a carbonate oligomer, and the carbonate oligomer has a structure shown in formula (C-2):

[0097]

[0098] After the first mixture was cooled, 155.58 g of bisphenol A type epoxy resin was added, and it was heated and stirred at 110 °C to form a second mixture. Then 1.2 g of triphenylphosphine (0.8 wt% of the epoxy resin) was added, and it was pre-reacted at 140 °C for 5 hours to obtain a curable carbonate composition c4.

[0099] Specifically, after the first mixture of Comparative Example 5 was measured by a gel permeation chromatograph, its number average molecular weight was 2,847 and its weight average molecular weight was 5,481.

[0100] <Preparation of Carbonate Cured Product>

[0101] <Examples 5 to 8>

[0102] Separate the curable carbonate compositions f1 to f4 prepared in Examples 1 to 4, add 0.2 weight percentage of 4-dimethylaminopyridine respectively, stir evenly and coat on an aluminum plate, bake at 150 °C for 30 minutes, and then raise the temperature to 180 °C for curing for 2 hours after drying, to obtain carbonate cured products C-f1, carbonate cured product C-f2, carbonate cured product C-f3 and carbonate cured product C-f4 respectively.

[0103] <Comparative Examples 6 to 9>

[0104] The specific operation is the same as that in Examples 5 to 8, except that the curable carbonate compositions f1 to f4 are replaced with curable carbonate compositions c1 to c4, and carbonate cured products C-c1, carbonate cured product C-c2, carbonate cured product C-c3 and carbonate cured product C-c4 can be obtained respectively.

[0105] <Stability Evaluation of Curable Carbonate Compositions>

[0106] Since conventional carbonate oligomers are prone to precipitation, sedimentation and other conditions after being formulated into a solution with epoxy resin, it is not easy to store stably. In the present invention, through pre-reaction with epoxy resin, the formed curable carbonate composition contains a carbonate epoxy copolymer as shown in formula (I), which has better solubility in solvents and avoids precipitation at room temperature. However, factors such as the molecular weight of carbonate oligomers and the selection of catalysts will be key influencing factors for improving stability, which will be further described below through the foregoing examples and comparative examples.

[0107] The following Table 1 shows the stability conditions of the curable carbonate compositions f1 to f4 and the curable carbonate compositions c1 to c4 at 78 °C, 60 °C and room temperature (25 °C) respectively. When the curable carbonate composition shows precipitation, sedimentation or gelation and other states, it is determined as the end point.

[0108]

[0109] As can be seen from Table 1 above, the curable carbonate compositions f1 to f4 prepared in Examples 1 to 4 can be stored at room temperature for more than 30 days without precipitation, separation, or other conditions. In contrast, the amount of bisphenol A added in Comparative Example 4 is less, and the molecular weight of the alcoholyzed carbonate oligomer is larger. Even if the subsequent procedures are the same as those in Example 1, it is impossible to successfully prepare a clear and stable curable carbonate composition.

[0110] In addition, since the monofunctional alcohols were used in the alcoholysis stage for the curable carbonate compositions c1 and c4 prepared in Comparative Example 1 and Comparative Example 5, the resulting carbonate oligomers had only one alcohol functional group at their ends. From the experimental results, even if the subsequent pre-reaction methods were the same as those in Example 1, the final products had poor stability due to fewer reaction sites. Therefore, precipitation occurred in the curable carbonate compositions c1 and c4 within less than 10 days at room temperature, and precipitation also occurred in the curable carbonate compositions c1 and c4 within 15 days in an environment of 60°C. It can be seen that if the carbonate oligomer has a diol functional group, it can have a great impact on the stability of the resulting curable carbonate composition.

[0111] The curable carbonate compositions f1 to f4 prepared in Examples 1 to 4 still have good stability in a relatively high-temperature environment, and can be stored stably for more than 10 days at 78°C and for more than 20 days at 60°C. The above results are because the second catalyst used in the pre-reaction stage has a weak catalytic effect, so that the curable carbonate composition is not easily gelled at high temperatures.

[0112] On the other hand, the amount of catalyst used in the pre-reaction stage for the curable carbonate composition c2 in Comparative Example 2 is similar to that in Example 1. However, the second catalyst is replaced from triphenylphosphine with a weaker catalytic ability to 2-phenylimidazole with a higher catalytic ability, so that the curable carbonate composition c2 gelled in about 1 day at 78°C, and the reaction still proceeded slowly at room temperature and gelled in about 28 days, so the storage stability was poor. The curable carbonate composition c3 was based on the curable carbonate composition c2 and the amount of the second catalyst was significantly reduced. Therefore, it did not gel at room temperature for more than 30 days, but gelled in only 2 days at 78°C and did not reach 30 days at 60°C, showing significant differences compared with Examples 1 to 4.

[0113] As can be seen from the above results, the storage stability of the curable carbonate composition is highly correlated with the end groups, molecular weight of the carbonate oligomer, and the catalyst added during the pre-reaction, which has a considerable impact on practical applications.

[0114] <Physical Property Evaluation of Carbonate Cured Products>

[0115] The thermal properties of the carbonate cured products of Examples 5 to 8 and Comparative Examples 6 to 9 were evaluated. The glass transition temperature (T g ) was measured using a differential scanning calorimeter (DSC) at a heating rate of 10 °C / min, and the measurement results of T g are listed in Table 2 below.

[0116]

[0117]

[0118] As can be seen from Table 2 above, the carbonate cured products C-f1 to C-f4 all exhibit excellent heat resistance with T g greater than 110 °C. For the circuit board industry where varnish products are often used, T g greater than 110 °C already meets the IPC-4101 / 122 specification for FR-4 rigid circuit boards. Moreover, as the number of functional groups of the epoxy resin increases, the resulting carbonate cured product can exhibit better heat resistance, indicating that the curable carbonate composition prepared by the present invention has the application potential as a basic formulation for electronic products.

[0119] It can be learned from the physical property tests of the carbonate cured products C-c2 and C-c3 that when different catalysts are used in the pre-reaction step, the impact on the performance of T g is not significant, but there will be significant differences in the stability performance of the curable carbonate composition (as shown in Table 1 above). In the carbonate cured products C-c1 and C-c4, since monofunctional alcohols are used as alcoholysis reagents in the alcoholysis process, the resulting carbonate oligomers only have a single alcohol functional group. In addition to the significant differences in the above-mentioned stability experiments, the resulting carbonate cured products also exhibit poor heat resistance, resulting in a reduced application value.

[0120] In summary, the curable carbonate composition of the present invention has characteristics such as a high solid content and high storage stability, can improve the mixing uniformity and solvent solubility during the curing process, can further simplify the process steps, reduce the energy consumption and by-product generation during the curing process, and the cured product can have good heat resistance, which is beneficial to be used as a basic formulation of epoxy varnish. Furthermore, the preparation method of the present invention can form carbonate oligomers by alcoholysis reaction of waste polycarbonate and directly prepare a curable carbonate composition without going through a purification step, achieving the purposes of high value utilization and recycling of waste polycarbonate.

[0121] Although the present invention has been disclosed as above by way of examples, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to that defined by the appended claims.

Claims

1. A curable carbonate composition, characterized in that, Comprising: A carbonate epoxy copolymer having a structure as shown in formula (I): Wherein, R1 and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an allyl group, an alkoxy group having 1 to 6 carbon atoms, an aromatic group having 6 to 12 carbon atoms, or a halogen atom; a and b are each independently an integer from 0 to 4; and n is an integer from 7 to 24; Wherein, Y is a chemical structure having at least one epoxy group; X and Z are each independently a single bond, or a structure as shown in formula (1), formula (2), formula (3), formula (4), formula (5), formula (6), formula (7), formula (8), formula (9), formula (10), or formula (11): Wherein, X1 and X2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms; A solvent selected from the group consisting of N,N-dimethylacetamide, N-methylpyrrolidone, dimethylformamide, anisole, dimethyl sulfoxide, propylene glycol methyl ether acetate, propylene glycol methyl ether propionate, and cyclohexanone; A first catalyst selected from the group consisting of 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, imidazole compounds, pyridine compounds, tertiary amine compounds, and quaternary ammonium salts; A second catalyst selected from the group consisting of triphenylphosphine, triphenylphosphine chloride derivatives, triphenylphosphine bromide derivatives, triphenylphosphine iodide derivatives, and quaternary ammonium salts; and An epoxy component.

2. A method for preparing a curable carbonate composition as described in claim 1, characterized in that, Comprising: Performing an alcoholysis reaction step of adding a polycarbonate and a first component into the solvent, heating to a first heating temperature and stirring. After the polycarbonate and the first component are dissolved, adding the first catalyst and maintaining the reaction at the first heating temperature to form a first mixture, and the first mixture contains a carbonate oligomer, wherein the first component has a structure as shown in formula (i), and the carbonate oligomer has a structure as shown in formula (ii): Performing a mixing step of adding a second component to the first mixture and maintaining stirring at a second heating temperature to form a second mixture, wherein the second component has at least two epoxy groups; and Performing a pre-reaction step of adding the second catalyst to the second mixture and maintaining stirring at a third heating temperature to form the curable carbonate composition.

3. The preparation method according to claim 2, characterized in that, The number average molecular weight of the first mixture is 1000 g / mole to 5000 g / mole.

4. The preparation method according to claim 2, characterized in that, The molar ratio of the first component to the polycarbonate is 6 to 20.

5. The preparation method according to claim 2, characterized in that, The addition amount of the first catalyst is 0.1 mole percentage to 1.0 mole percentage of the content of the first component in the first mixture.

6. The preparation method according to claim 2, characterized in that, The first heating temperature is 110°C to 170°C.

7. The preparation method according to claim 2, wherein The second component contains at least one epoxy compound, the at least one epoxy compound has at least two epoxy groups, and when the number of the at least one epoxy compound is two or more, each of the at least one epoxy compound has a different chemical structure.

8. The preparation method according to claim 2, characterized in that, The addition amount of the second component is 15 wt% to 65 wt% of the total amount of the second mixture.

9. The preparation method according to claim 8, characterized in that, The addition amount of the second component is 25 wt% to 50 wt% of the total amount of the second mixture.

10. The preparation method according to claim 2, characterized in that, The second heating temperature is 60 °C to 150 °C.

11. The preparation method according to claim 2, characterized in that, The third heating temperature is 130 °C to 160 °C.

12. The preparation method according to claim 2, characterized in that, The addition amount of the second catalyst is 0.05 wt% to 1.50 wt% of the content of the second component in the second mixture.

13. The preparation method according to claim 2, characterized in that, The solid content of the curable carbonate composition is 40 wt% to 80 wt%.

14. A carbonate cured product, characterized in that, It is obtained by adding a promoter to the curable carbonate composition according to claim 1 and reacting it at a curing temperature.

15. The carbonate cured product according to claim 14, wherein The promoter is selected from the group consisting of 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, imidazole compounds, pyridine compounds and tertiary amine compounds.

16. The carbonate cured product according to claim 14, wherein The addition amount of the promoter is 0.05 wt% to 1.50 wt% of the total amount of the curable carbonate composition.

17. The carbonate cured product according to claim 14, characterized in that, The curing temperature is 150 °C to 240 °C.

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