Curable carbonate composition and preparation method therefor, and carbonate cured product

Abstract

The present disclosure provides a curable carbonate composition, comprising 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), formula (I). Therefore, the present disclosure can achieve the improvement of the mixing uniformity and solvent solubility in the curing process, simplification of the process steps, and reduced energy consumption and generation of the byproducts in the curing process.

Description

Curable carbonate composition, preparation method thereof and carbonate cured product Technical Field

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

[0002] Polycarbonate (PC) is a thermoplastic polymer formed by a high-temperature transesterification reaction between bisphenol A and diphenyl carbonate. As one of the five major engineering plastics, PC boasts excellent transparency, impact resistance, and heat resistance, making it widely used in consumer products such as eyeglass lenses, optical discs, data storage devices, and automotive headlights.

[0003] When aromatic carbonate structures and epoxy structures undergo an ester exchange reaction at high temperatures under the catalysis of N,N-dimethylbenzylamine (BDMA), the aromatic carbonate structures are replaced by aliphatic carbonate structures. A cyclization side reaction also occurs, forming ethylene carbonate structures. This cyclization side reaction can cause molecular chain scissions in the cured product and disrupt the integrity of the cured product's network structure. Therefore, if you want to use carbonate and epoxy structures to produce cured products with high heat resistance, you must first overcome the problems caused by the cyclization side reaction.

[0004] Furthermore, if diphenol monomers, which have a more complex chemical structure than bisphenol A, are used as raw materials to synthesize carbonate oligomers, the resulting product can be melt-mixed with epoxy resin and cured at high temperatures. Compared to carbonate oligomers prepared using bisphenol A as raw material, the cured product obtained using diphenol monomers has better heat resistance. However, this synthesis method has the disadvantage that carbonate oligomers must be synthesized from monomers at temperatures exceeding 200°C. Furthermore, the byproduct phenol must be separated by vacuum distillation, resulting in significant energy consumption.

[0005] Furthermore, if waste polycarbonate is directly used as a hardener for epoxy resin, the resulting solidified product exhibits high heat resistance and biodegradability. Degradation of the solidified product yields a high-molecular-weight phenoxy resin, which can be used as a chemical additive in coatings and other applications, providing a more environmentally friendly and cost-effective solution for waste polycarbonate. However, the aforementioned treatment solution suffers from the high melting point of waste polycarbonate, making it difficult to directly melt and mix with epoxy resin at high temperatures. Furthermore, due to the high molecular weight of waste polycarbonate, its solubility in organic solvents is poor. Consequently, the solids content of the waste polycarbonate solution can only reach 10 to 30 weight percent, significantly limiting its practical application.

[0006] As can be seen, in currently known technologies, carbonate oligomers must be obtained by polymerizing monomers, and the energy consumption and byproduct disposal issues of high-temperature processes remain challenges to be overcome. Furthermore, while carbonate oligomers can be co-cured with epoxy resins, there are still significant deficiencies in mixing uniformity during the curing process, solvent solubility, and storage stability.

[0007] Summary of the Invention

[0008] The present disclosure aims to provide a curable carbonate composition, the cured product of which can maintain good heat resistance, further solve the problems of high energy consumption and by-products in the process, and at the same time improve the mixing uniformity, solvent solubility, or storage stability in the process.

[0009] One embodiment of the present disclosure provides a curable carbonate composition comprising 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):

[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, such as 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):

[0011] 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 amine salts. The second catalyst is selected from the group consisting of triphenylphosphine, triphenylphosphine chloride derivatives, triphenylphosphine bromide derivatives, triphenylphosphine iodide derivatives, and quaternary amine salts.

[0012] The curable carbonate composition disclosed herein thus has properties such as high solid content and high storage stability, can improve mixing uniformity and solvent solubility during the curing process, and can further simplify the process steps, reduce energy consumption and by-product generation during the curing process. Furthermore, the cured product can have good heat resistance, making it suitable as a base formulation for epoxy resin varnish.

[0013] Another embodiment of the present disclosure provides a method for preparing the aforementioned curable carbonate composition, comprising the following steps: performing an alcoholysis reaction step, wherein a polycarbonate and a first component are added to a solvent, and the temperature is raised to a first heating temperature and stirred. After the polycarbonate and the first component are dissolved, a first catalyst is added and the reaction is maintained at the first heating temperature to form a first mixture, wherein the first mixture comprises 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):

[0014] A mixing step is performed, wherein a second component is added to the first mixture and stirred at a second heating temperature to form a second mixture, wherein the second component has at least a diepoxy group. A pre-reaction step is performed, wherein a second catalyst is added to the second mixture and stirred at a third heating temperature to form a curable carbonate composition.

[0015] According to the aforementioned preparation method, a number average molecular weight of the first mixture may be 1000 g / mole to 5000 g / mole.

[0016] According to the aforementioned preparation method, a molar ratio of the first component to the polycarbonate can be 6 to 20.

[0017] According to the aforementioned preparation method, an added amount of the first catalyst may be 0.1 mol % to 1.0 mol % of a content of the first component in the first mixture.

[0018] According to the aforementioned preparation method, the first heating temperature may be 110°C to 170°C.

[0019] According to the aforementioned preparation method, the second component may include at least one epoxy compound having at least one diepoxy group. When the number of the epoxy compounds is two or more, each epoxy compound may have a different chemical structure.

[0020] According to the aforementioned preparation method, an addition amount of the second component can be 15 weight percent to 65 weight percent of the total amount of the second mixture.

[0021] According to the aforementioned preparation method, the amount of the second component added can be 25 weight percent to 50 weight percent of the total amount of the second mixture.

[0022] According to the aforementioned preparation method, the second heating temperature may be 60°C to 150°C.

[0023] According to the aforementioned preparation method, the third heating temperature may be 130°C to 160°C.

[0024] According to the aforementioned preparation method, an added amount of the second catalyst may be 0.05 weight percent to 1.50 weight percent of a content of the second component in the second mixture.

[0025] According to the aforementioned preparation method, the solid content of the curable carbonate composition may be 40 weight percent to 80 weight percent.

[0026] Another embodiment of the present disclosure provides a carbonate cured product, which is obtained by adding an accelerator to the aforementioned curable carbonate composition and heating it to a curing temperature for reaction.

[0027] According to the aforementioned carbonate curing material, the accelerator can be 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.

[0028] According to the aforementioned carbonate cured material, an amount of the accelerator added may be 0.05 weight percent to 1.50 weight percent of the total amount of the curable carbonate composition.

[0029] According to the aforementioned carbonate cured material, the curing temperature may be 150°C to 240°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] To make the above and other objects, features, advantages and embodiments of the present disclosure more apparent and understandable, the accompanying drawings are described as follows:

[0031] FIG1 is a flow chart showing the steps of the method for preparing the curable carbonate composition of the present disclosure.

[0032] [Description of symbols] 100: Preparation method 110, 120, 130: Steps f1, f2, f3, f4, c1, c2, c3, c4: Curable carbonate composition C-f1, C-f2, C-f3, C-f4, C-c1, C-c2, C-c3, C-c4: Carbonate cured product DETAILED DESCRIPTION

[0033] The following will discuss various embodiments of the present disclosure in more detail. However, this embodiment can be an application of various inventive concepts and can be specifically implemented in a variety of different specific scopes. The specific embodiments are for illustrative purposes only and are not limited to the scope of the disclosure.

[0034] In this disclosure, compound structures are sometimes represented using skeletal formulas. This representation may omit carbon atoms, hydrogen atoms, and carbon-hydrogen bonds. If a functional group is explicitly depicted in a structural formula, the depicted functional group shall prevail.

[0035] In this disclosure, for the sake of brevity and fluency, “a first component having a structure as shown in formula (i)” may sometimes be expressed as “a first component as shown in formula (i)” or “first component (i)”, and the same applies to other compounds or groups.

[0036] <Curable Carbonate Composition>

[0037] One embodiment of the present disclosure provides a curable carbonate composition comprising 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):

[0038] 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 the degree of polymerization, which 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, such as 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):

[0039] 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, first catalyst, second catalyst, and epoxy component will be described in subsequent paragraphs and will not be repeated here.

[0040] <Method for preparing curable carbonate composition>

[0041] 1 is a flow chart of the steps of a method 100 for preparing a curable carbonate composition according to the present disclosure, wherein the method 100 comprises steps 110 , 120 , and 130 .

[0042] Step 110 is an alcoholysis step, in which a polycarbonate and a first component are added to a solvent, heated to a first heating temperature, and stirred. After the polycarbonate and the first component are dissolved, a first catalyst is added and the reaction is maintained at the first heating temperature to form a first mixture. The first mixture includes 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):

[0043] A molar ratio of the first component to the polycarbonate can be 6 to 20, where the molar ratio 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-methylpyrrolidone (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.

[0044] The first catalyst may be added in an amount ranging from 0.1 mol % to 1.0 mol % of the first component in the first mixture. The first catalyst may 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.

[0045] The first mixture may have a number average molecular weight of 1000 g / mole to 5000 g / mole, and preferably 2000 g / mole to 4000 g / mole.

[0046] Step 120 is a mixing step, in which a second component is added to the first mixture and stirred at a second heating temperature to form a second mixture, wherein the second component has at least diepoxy groups.

[0047] The second component may include at least one epoxy compound having at least two epoxy groups. When the number of epoxy compounds is two or more, each epoxy compound may have a different chemical structure. For example, an epoxy compound having multiple epoxy groups may be combined with an epoxy compound having two epoxy groups, an epoxy compound having two epoxy groups may be combined with an epoxy compound having two epoxy groups, an epoxy compound having multiple epoxy groups may be combined with an epoxy compound having multiple epoxy groups, or other epoxy compounds. The present disclosure is not limited to the above-mentioned combinations. The epoxy compound may be a bisphenol A epoxy resin, a novolac multifunctional epoxy resin, or other type of epoxy resin. The amount of the second component added may be 15 to 65 weight percent of the total amount of the second mixture, preferably 25 to 50 weight percent of the total amount of the second mixture. The second heating temperature may be 60°C to 150°C.

[0048] Step 130 is a pre-reaction step, in which a second catalyst is added to the second mixture and stirred at a third heating temperature to form a curable carbonate composition, wherein a solid content of the curable carbonate composition can be 40 weight percent to 80 weight percent, where the solid content is the weight ratio of the curable carbonate composition before and after the solvent is removed.

[0049] 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 amine salts. The second catalyst may be added in an amount ranging from 0.05 weight percent to 1.50 weight percent of the second component in the second mixture.

[0050] It should be noted that the aforementioned preparation method 100 can obtain the curable carbonate composition of this embodiment after the reaction is completed and without purification. Therefore, the curable carbonate composition can be directly used in subsequent applications without purification, thereby improving application convenience and reducing manufacturing costs.

[0051] <Carbonate cured product>

[0052] Another embodiment of the present disclosure provides a carbonate cured product, which is obtained by adding an accelerator to the aforementioned curable carbonate composition and heating it to a curing temperature for reaction.

[0053] The accelerator can be 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. The accelerator can be added in an amount of 0.05 to 1.50 weight percent based on the total weight of the curable carbonate composition. The curing temperature can be 150°C to 240°C.

[0054] The present disclosure is further illustrated by the following specific embodiments, which are intended to facilitate those skilled in the art to which the present disclosure relates, so that they can fully utilize and practice the present disclosure without excessive interpretation. These embodiments should not be construed as limiting the scope of the present disclosure, but are intended to illustrate how to implement the materials and methods of the present disclosure.

[0055] <Preparation of Curable Carbonate Composition>

[0056] <Example 1>

[0057] Take 100g (5×10 -3 mole) of recycled polycarbonate crushed material (purchased from Jiuxuan Technology Co., Ltd., product code RPC-y) and 12.35 g of bisphenol A (5.5×10 -2 mole), 100 g of cyclohexanone solvent was added, the temperature was raised to 150° C. and then maintained at the temperature with stirring, followed by the addition of 0.016 g (0.2 mol% of bisphenol A) of 1,8-diazabicyclo[5.4.0]undec-7-ene, and the mixture was reacted for 6 hours to form a first mixture, the first mixture comprising a carbonate oligomer, and the carbonate oligomer having a structure as shown in formula (ii-a):

[0058] After the first mixture was cooled, 150.39 g of bisphenol A epoxy resin (DGEBA) was added, and the mixture was heated and stirred at 140°C to form a second mixture. Next, 1.2 g of triphenylphosphine (0.8 wt% of the epoxy resin) was added, and the mixture was pre-reacted at 140°C for 2.5 hours to obtain a curable carbonate composition f1 comprising the carbonate epoxy copolymer represented by formula (Ia). The curable carbonate composition f1 had a clear, light yellow solution.

[0059] Specifically, the recycled polycarbonate crushed material RPC-y had a number average molecular weight of 18491 and a weight average molecular weight (Mw) of 40990. The first mixture of Example 1, as measured by gel permeation chromatograph (GPC), had a number average molecular weight of 2872 and a weight average molecular weight of 5490.

[0060] <Example 2>

[0061] The preparation method for the first mixture in Example 2 was the same as that in Example 1, except that the subsequent process was modified as follows: After the first mixture was cooled, 172.51 g of a novolac-type multifunctional epoxy resin (purchased from Changchun Group, product code CNE-195) was added, and the mixture was heated and stirred at 120°C to form a second mixture. Subsequently, 1.38 g of triphenylphosphine (0.8 wt% of the epoxy resin) was added, and a pre-reaction was carried out at 140°C for 2.5 hours to obtain a curable carbonate composition f2 comprising the carbonate-epoxy copolymer represented by Formula (Ib). The curable carbonate composition f2 had a clear, light yellow solution.

[0062] Specifically, after the first mixture of Example 2 was measured by gel chromatography osmometer, its number average molecular weight was 2585 and its weight average molecular weight was 5351.

[0063] <Example 3>

[0064] The preparation method for the first mixture in Example 3 was the same as that in Example 1, except that the subsequent process was modified as follows: After cooling the first mixture, 101.73 g of 4,4'-methylenebis(N,N-diglycidylaniline) (Tetraglycidyl methylenedianiline; TGDDM) was added, and the mixture was heated and stirred at 120°C to form a second mixture. Subsequently, 0.81 g of triphenylphosphine (0.8 wt% of the epoxy resin) was added, and a pre-reaction was carried out at 140°C for 4 hours to obtain a curable carbonate composition f3, which contained the carbonate epoxy copolymer represented by Formula (Ic). The curable carbonate composition f3 had a clear orange-red solution:

[0065] Specifically, after the first mixture of Example 3 was measured by gel chromatography osmometer, its number average molecular weight was 2378 and its weight average molecular weight was 4883.

[0066] <Example 4>

[0067] 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), ultimately yielding a curable carbonate composition f4 comprising the carbonate epoxy copolymer represented by formula (Ia). The curable carbonate composition f4 had a clear, light yellow solution. The first mixture of Example 4, as measured by gel chromatography permeameter, had a number average molecular weight of 3238 and a weight average molecular weight of 6877.

[0068] <Comparative Example 1>

[0069] Take 100g (5×10 -3 mole) of recycled polycarbonate crushed material RPC-y and 10.61 g of furfuryl alcohol (1.08×10 -1 mole), 100 g of cyclohexanone solvent was added, the temperature was raised to 150° C. and then maintained at the temperature with stirring, followed by the addition of 0.032 g (0.2 mol% of furfuryl alcohol) of 1,8-diazabicyclo[5.4.0]undec-7-ene, and the mixture was reacted for 6 hours to form a first mixture. The first mixture contained a carbonate oligomer, and the carbonate oligomer had a structure as shown in Formula (C-1):

[0070] After the first mixture was cooled, 148.06 g of bisphenol A epoxy resin was added, and the mixture was heated and stirred at 110° C. to form a second mixture. Subsequently, 1.2 g of triphenylphosphine (0.8 wt % of the epoxy resin) was added, and the mixture was pre-reacted at 140° C. for 5 hours to obtain a curable carbonate composition c1.

[0071] Specifically, after the first mixture of Comparative Example 1 was measured by gel chromatography osmometer, its number average molecular weight was 2847 and its weight average molecular weight was 5481.

[0072] <Comparative Example 2>

[0073] The preparation method of Comparative Example 2 is the same as that of Example 1, except that triphenylphosphine is replaced with 2-phenylimidazole in an amount of 0.6 g (0.4 wt % of the epoxy resin), and the pre-reaction temperature is replaced with 100° C., to obtain a curable carbonate composition c2, and the solution of the curable carbonate composition c2 is a clear reddish brown.

[0074] Specifically, after the first mixture of Comparative Example 2 was measured by gel chromatography osmometer, its number average molecular weight was 2687 and its weight average molecular weight was 5307.

[0075] <Comparative Example 3>

[0076] The preparation method of Comparative Example 3 is the same as that of Comparative Example 2, except that the amount of 2-phenylimidazole is changed to 0.15 g (0.1 wt % of the epoxy resin). A curable carbonate composition c3 is obtained, and the solution of the curable carbonate composition c3 is clear reddish brown.

[0077] Specifically, after the first mixture of Comparative Example 3 was measured by gel chromatography osmometer, its number average molecular weight was 2817 and its weight average molecular weight was 5421.

[0078] <Comparative Example 4>

[0079] The preparation method of Comparative Example 4 is the same as that of Example 1, except that the amount of bisphenol A is changed to 6.17 g (2.7×10 -2 The first mixture obtained in Comparative Example 4 was measured by gel chromatography osmometer, and its number average molecular weight was 5559 and weight average molecular weight was 9729. In addition, many floating insoluble materials appeared in the subsequent process, making it impossible to obtain the final composition smoothly.

[0080] <Comparative Example 5>

[0081] Take 100g (5×10 -3 mole) of recycled polycarbonate crushed material RPC-y and 16.23 g of p-tert-butylphenol (PTBP; 1.08×10 -1mole), 100 g of cyclohexanone solvent was added, the temperature was raised to 150° C. and then maintained at the temperature with stirring, followed by the addition of 0.032 g (0.2 mol% of p-butylbenzene) of 1,8-diazabicyclo[5.4.0]undec-7-ene, and the mixture was reacted for 6 hours to form a first mixture, the first mixture comprising a carbonate oligomer, and the carbonate oligomer having a structure as shown in formula (C-2):

[0082] After the first mixture was cooled, 155.58 g of bisphenol A epoxy resin was added, and the mixture was heated and stirred at 110° C. to form a second mixture. Subsequently, 1.2 g of triphenylphosphine (0.8 wt % of the epoxy resin) was added, and the mixture was pre-reacted at 140° C. for 5 hours to obtain a curable carbonate composition C4.

[0083] Specifically, after the first mixture of Comparative Example 5 was measured by gel chromatography osmometer, its number average molecular weight was 2847 and its weight average molecular weight was 5481.

[0084] <Preparation of Carbonate Cured Material>

[0085] <Examples 5 to 8>

[0086] Take the curable carbonate compositions f1 to f4 prepared in Examples 1 to 4, respectively, add 0.2 weight percent of 4-dimethylaminopyridine, stir evenly and then apply it on an aluminum plate, bake at 150°C for 30 minutes, dry and then heat to 180°C for curing for 2 hours, to obtain carbonate cured product C-f1, carbonate cured product C-f2, carbonate cured product C-f3 and carbonate cured product C-f4, respectively.

[0087] <Comparative Examples 6 to 9>

[0088] The specific method is the same as that of Examples 5 to 8, except that the curable carbonate compositions f1 to f4 are replaced with the 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.

[0089] <Stability Evaluation of Curable Carbonate Composition>

[0090] Since conventional carbonate oligomers and epoxy resins are easily separated and precipitated after being formulated into solutions, they are not easy to store stably. The present disclosure pre-reacts with the epoxy resin to form a curable carbonate composition comprising a carbonate epoxy copolymer as shown in formula (I), which has good solubility in solvents and avoids precipitation at room temperature. However, factors such as the molecular weight of the carbonate oligomer and the choice of catalyst are key factors affecting stability, which will be further explained below through the aforementioned embodiments and comparative examples.

[0091] Table 1 below shows the stability of curable carbonate compositions f1 to f4 and curable carbonate compositions c1 to c4 at 78°C, 60°C, and room temperature (25°C), respectively. The endpoint is determined when the curable carbonate composition shows precipitation, settling, or gelling.

[0092] As shown in Table 1 above, the curable carbonate compositions f1 to f4 prepared in Examples 1 to 4 could be stored at room temperature for over 30 days without any precipitation or other issues. In contrast, the amount of bisphenol A added in Comparative Example 4 was smaller, resulting in a higher molecular weight of the carbonate oligomer after alcoholysis. Even with the same subsequent procedures as in Example 1, a clear and stable curable carbonate composition could not be successfully prepared.

[0093] Furthermore, because the curable carbonate compositions C1 and C4 prepared in Comparative Examples 1 and 5 used monofunctional alcohols in the alcoholysis stage, the carbonate oligomers after alcoholysis had only one alcohol functional group at their terminals. Experimental results indicate that even if the subsequent pre-reaction method was the same as in Example 1, the resulting products exhibited poor stability due to the relatively few reaction points. Consequently, the curable carbonate compositions C1 and C4 exhibited precipitation within 10 days at room temperature, and even within 15 days at 60°C. This demonstrates that the presence of a diol functional group in a carbonate oligomer can significantly impact the stability of the resulting curable carbonate composition.

[0094] The curable carbonate compositions f1 to f4 prepared in Examples 1 to 4 exhibited excellent stability even in relatively high-temperature environments, remaining stable for over 10 days at 78°C and over 20 days at 60°C. These results are attributed to the relatively weak catalytic effect of the second catalyst used in the pre-reaction stage, which prevents the curable carbonate compositions from gelling even at high temperatures.

[0095] On the other hand, the amount of catalyst used in the pre-reaction stage of curable carbonate composition C2 in Comparative Example 2 was similar to that in Example 1, except that the second catalyst was replaced with 2-phenylimidazole, which has a higher catalytic ability, instead of triphenylphosphine, which has a weaker catalytic ability. This resulted in curable carbonate composition C2 undergoing gelation in approximately one day at 78°C. Furthermore, the reaction continued slowly at room temperature, with gelation occurring after approximately 28 days, resulting in poor storage stability. Curable carbonate composition C3, based on curable carbonate composition C2, significantly reduced the amount of the second catalyst. As a result, it remained gelatin-free for over 30 days at room temperature. However, gelation occurred after only two days at 78°C and before 30 days at 60°C, representing significant differences compared to Examples 1 to 4.

[0096] From the above results, it can be seen that the storage stability of the curable carbonate composition is closely related to the terminal group and molecular weight of the carbonate oligomer and the catalyst added during the pre-reaction, which has a considerable impact on practical applications.

[0097] <Physical Property Evaluation of Carbonate Cured Product>

[0098] Thermal properties of the carbonate cured products of Examples 5 to 8 and Comparative Examples 6 to 9 were evaluated by measuring the glass transition temperature (T) using a differential scanning calorimeter (DSC) at a heating rate of 10°C / min. g ) and T g The measurement results are listed in Table 2 below.

[0099] As shown in Table 2 above, carbonate cured products C-f1 to C-f4 all exhibit T g Excellent heat resistance greater than 110℃, in the circuit board industry where varnish products are often used, T g A temperature greater than 110°C can meet the IPC-4101 / 122 specifications for FR-4 rigid circuit boards, and as the number of functional groups in the epoxy resin increases, the resulting carbonate cured product can exhibit better heat resistance, indicating that the curable carbonate composition prepared in the present disclosure has application potential as a basic formulation for electronic products.

[0100] The physical property tests of carbonate cured products C-c2 and C-c3 show that if different catalysts are used in the pre-reaction step, the T gWhile the impact on performance is minimal, significant differences can occur in the stability of the curable carbonate compositions (as shown in Table 1). In carbonate cured products C-c1 and C-c4, the use of monofunctional alcohols as alcoholysis reagents in the alcoholysis process results in the resulting carbonate oligomers possessing only a single alcohol functional group. This not only produces significant differences in the aforementioned stability tests, but also results in poor heat resistance, reducing their application value.

[0101] In summary, the curable carbonate composition disclosed herein has properties such as high solids content and high storage stability. It can improve mixing uniformity and solvent solubility during the curing process, simplify process steps, reduce energy consumption and byproduct generation during the curing process, and the cured product has excellent heat resistance, making it suitable as a base formulation for epoxy resin varnishes. Furthermore, the preparation method disclosed herein can directly prepare a curable carbonate composition from waste polycarbonate through an alcoholysis reaction to form carbonate oligomers without undergoing a purification step, thereby achieving the goals of increasing the value of waste polycarbonate and enabling its reuse.

[0102] Although the present disclosure has been disclosed above with reference to the embodiments, they are not intended to limit the present disclosure. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined 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, and X and Z are each independently a single bond or 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)): 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: Perform a methanolysis reaction step by adding a polycarbonate and a first component to the solvent, heating to a first heating temperature and stirring. After the polycarbonate and the first component are dissolved, add the first catalyst and maintain 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 shown in formula (i), and the carbonate oligomer has a structure shown in formula (ii): Performing a mixing step of adding a second component to the first mixture and 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 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 mol% to 1.0 mol% 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, characterized in that, The second component comprises at least one epoxy compound having 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 at a curing temperature after heating.

15. The carbonate cured product according to claim 14, wherein, The accelerator is 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.

16. The carbonate cured product according to claim 14, characterized in that, An addition amount of the accelerator is 0.05 wt% to 1.50 wt% of a total amount of the curable carbonate composition.

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

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