Synthesis method and application of polyethylene naphthalate copolymer
By adopting the new synthesis method of polyethylene naphthalate copolymer, dimethyl 2,6-naphthalate dimethyl 1,4-succinate as raw materials, the problem of high cost of synthetic raw materials has been solved. , achieves cost reduction and performance improvement, and is suitable for a variety of high-performance materials.
Patent Information
- Application Number
- CN202411570665.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-07
AI Technical Summary
In the prior art, the synthetic raw material cost of polyethylene naphthalate copolymer is relatively high, which limits its widespread use in downstream applications.
Using a new synthetic method, dimethyl 2,6-naphthalene dimethyl and dimethyl 1,4-succinate are used through four steps: first esterification, second esterification, prepolycondensation and finalization. Esters are used as the source of carboxyl groups for the esterification reaction, and 2,6-naphthalene diacid is avoided as the raw material, thereby reducing the synthesis cost.
It effectively reduces the synthesis cost of polyethylene naphthalate copolymer, and at the same time increases the intrinsic viscosity of the product. It is suitable for special films, special fibers and high-temperature resistant containers and other fields.
Smart Images
Figure CN119390956A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of polymer material preparation, and in particular relates to a synthesis method of a polyethylene naphthalate copolymer and its application. Background Art
[0002] Polyethylene naphthalate (PEN) is a saturated polyester with excellent comprehensive properties. It has a high glass transition temperature and can be used in special occasions such as high temperature. At the same time, PEN also has excellent physical and mechanical properties, gas barrier properties, chemical stability, heat resistance, chemical resistance, UV resistance, radiation resistance, etc., and is used to manufacture special films, special fibers, high-temperature resistant containers and other fields.
[0003] The synthesis methods of PEN include direct esterification and transesterification. Direct esterification is a more commonly used synthesis method, which is to use 2,6-naphthalene dicarboxylic acid and ethylene glycol as raw materials, and then carry out esterification reaction and polycondensation reaction to synthesize PEN. When using the direct esterification method to synthesize PEN, the purity of the raw material naphthalene dicarboxylic acid is very high. However, due to the single source of 2,6-naphthalene dimethyl ester raw materials and the huge pressure of high cost, the market price of PEN products is relatively high, which limits the application of downstream manufacturers.
[0004] Therefore, a synthesis method and application of polyethylene naphthalate copolymers are developed to solve the technical defect of high cost of synthetic raw materials of polyethylene naphthalate copolymers in the prior art, which has become an urgent problem to be solved by those skilled in the art. Summary of the invention
[0005] Based on this, it is necessary to provide a method for synthesizing polyethylene naphthalate copolymer and its application in view of the technical defect that the polyethylene naphthalate copolymer has high cost of synthetic raw materials in the existing technology.
[0006] The present application provides a method for synthesizing a polyethylene naphthalate copolymer, the method comprising:
[0007] Step 1, first esterification: after mixing dimethyl 2,6-naphthalene dicarboxylate, ethylene glycol and a first catalyst, a first esterification reaction occurs to obtain a first transesterification product;
[0008] Step 2, second esterification: After mixing dimethyl 1,4-succinate, diol and catalyst, a second esterification reaction occurs to obtain a second transesterification product;
[0009] Step 3, pre-polycondensation: after mixing the first transesterification product and the second transesterification product, adding a third catalyst to cause a polycondensation reaction to obtain a pre-polycondensation product;
[0010] Step 4: Final polymerization: The pre-polycondensation product undergoes a final polymerization reaction to obtain a polyethylene terephthalate copolymer product.
[0011] In one embodiment, in step 2, the diol is selected from: isosorbide, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, tricyclodecane dimethanol, pentacyclopentadecanedimethanol, 2,6-decahydronaphthalene dimethanol, 1,5-decahydronaphthalene dimethanol, 2,3-decahydronaphthalene dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol and 1,3-adamantanedimethanol.
[0012] In one embodiment, the feed ratio of dimethyl 2,6-naphthalene diate to ethylene glycol is 1:(2.0-2.4) in molar parts;
[0013] and / or,
[0014] In step 1, the feeding amount of the first catalyst is 0.001wt% to 0.5wt% of dimethyl 2,6-naphthalene dicarboxylate;
[0015] and / or,
[0016] In step 1, the temperature of the first transesterification reaction is 220°C to 260°C.
[0017] In one embodiment, the feed ratio of dimethyl 2,6-naphthalene diate to ethylene glycol is 1:2.2 in molar parts;
[0018] and / or,
[0019] The feeding amount of the first catalyst is 0.001wt% to 0.1wt% of 2,6-naphthalene dimethyl ester;
[0020] and / or,
[0021] The temperature of the first transesterification reaction is 220°C to 240°C.
[0022] In one embodiment, the feed ratio of dimethyl 1,4-succinate to diol is 1:(1.0-1.2) in molar parts;
[0023] and / or,
[0024] The feeding amount of the second catalyst is 0.001wt% to 0.5wt% of 1,4-dimethyl succinate;
[0025] and / or,
[0026] The temperature of the second transesterification reaction is 160°C to 200°C.
[0027] In one embodiment, the feed ratio of dimethyl 1,4-succinate to diol is 1:1.1 in molar parts;
[0028] and / or,
[0029] The feeding amount of the second catalyst is 0.001wt% to 0.5wt% of 1,4-dimethyl succinate;
[0030] and / or,
[0031] The temperature of the second transesterification reaction is 160°C to 180°C.
[0032] In one embodiment, the first catalyst is selected from any one or more of manganese acetate, cobalt acetate, zinc acetate, magnesium acetate and calcium acetate;
[0033] and / or,
[0034] The second catalyst is selected from any one or more of manganese acetate, cobalt acetate, zinc acetate, magnesium acetate and calcium acetate.
[0035] In one embodiment, the first catalyst is: manganese acetate and / or zinc acetate;
[0036] and / or,
[0037] The second catalyst is: manganese acetate and / or zinc acetate.
[0038] In one embodiment, the feed ratio of the first transesterification product to the second transesterification product is 1:(0.1-1.0) in molar parts.
[0039] In one embodiment, the feed ratio of the first transesterification product to the second transesterification product is 1:(0.3-0.5) in molar parts.
[0040] In one embodiment, the third catalyst is selected from any one or more of antimony ethylene glycol, antimony trioxide and tetrabutyl titanate, and the feeding amount of the third catalyst is 0.001wt% to 0.5wt% of 1,4-dimethyl succinate.
[0041] In one embodiment, the temperature of the polycondensation reaction is 220° C. to 260° C., and the pressure of the polycondensation reaction is 10 KPa to 50 KPa.
[0042] In one embodiment, the temperature of the polycondensation reaction is 220° C. to 240° C., and the pressure of the polycondensation reaction is 10 KPa to 30 KPa.
[0043] In one embodiment, the temperature of the final polymerization reaction is 240°C to 280°C, and the pressure of the final polymerization reaction is 0Pa to 200Pa.
[0044] In one embodiment, the temperature of the final polymerization reaction is 240° C. to 260° C., and the pressure of the final polymerization reaction is 0 Pa to 50 Pa.
[0045] The present application also provides an application of a polyethylene naphthalate copolymer prepared by any of the above synthesis methods in special films, special fibers and high-temperature resistant containers.
[0046] In summary, the present application provides a method for synthesizing polyethylene naphthalate copolymers, which includes: first esterification, second esterification, pre-condensation and final polymerization. The present application also provides an application of polyethylene naphthalate copolymers obtained by the above-mentioned synthesis method in special films, special fibers and high temperature resistant containers. In the technical scheme provided by the present application, the first esterification and the second esterification use 2,6-naphthalene dicarboxylic acid dimethyl ester and 1,4-succinic acid dimethyl ester as the carboxyl source of the esterification reaction, respectively, and do not use 2,6-naphthalene dicarboxylic acid as the reaction raw material. The raw material source of the carboxyl donor is wide and low in price, which effectively reduces the synthesis cost of polyethylene naphthalate copolymers; after further determination, the obtained polyethylene naphthalate copolymer has a characteristic viscosity of 0.6 to 1.5 dL / g, which has excellent performance. The synthesis method and application of a polyethylene naphthalate copolymer provided by the present application solve the technical defects of the high cost of synthetic raw materials in the prior art of polyethylene naphthalate copolymers. BRIEF DESCRIPTION OF THE DRAWINGS
[0047] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.
[0048] Figure 1 In the technical solution provided in the embodiment of the present application, a schematic flow chart of a method for synthesizing a polyethylene naphthalate copolymer is provided. DETAILED DESCRIPTION
[0049] The embodiments of the present application provide a method for synthesizing a polyethylene naphthalate copolymer and an application thereof, which are used to solve the technical defect in the prior art that the polyethylene naphthalate copolymer has a high cost of synthesizing raw materials.
[0050] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.
[0051] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0053] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0054] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0055] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.
[0056] The following will be combined Figure 1 According to the synthesis method of polyethylene naphthalate copolymer provided in the present application, the synthesis of polyethylene naphthalate copolymer is carried out.
[0057] Example 1
[0058] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0059] Using dimethyl 1,4-succinate and isosorbide as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0060] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.3) are mixed, and tetrabutyl titanate (0.01wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 220°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 250°C and 100Pa to obtain a polyethylene naphthalate copolymer.
[0061] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.81dL / g.
[0062] Example 2
[0063] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0064] Using dimethyl 1,4-succinate and 1,3-propylene glycol as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0065] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.3) are mixed, and tetrabutyl titanate (0.05wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 230°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 250°C and 100Pa to obtain a polyethylene naphthalate copolymer.
[0066] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.60dL / g.
[0067] Example 3
[0068] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0069] Using dimethyl 1,4-succinate and isosorbide as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0070] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.5) are mixed, and tetrabutyl titanate (0.05wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 230°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 260°C and 80Pa to obtain a polyethylene naphthalate copolymer.
[0071] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.87dL / g.
[0072] Example 4
[0073] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.4), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0074] Using dimethyl 1,4-succinate and isosorbide as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0075] The first transesterification product and the second transesterification product (molar ratio of 1:0.3) were mixed and then antimony ethylene glycol (0.01 wt% based on the mass of the first and second transesterification products) was added, and a condensation reaction was carried out at 220°C and 30 KPa to obtain a pre-condensation product, and the pre-condensation product was subjected to a final polymerization reaction at 260°C and 100 Pa to obtain a polyethylene naphthalate copolymer.
[0076] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 1.13dL / g.
[0077] Example 5
[0078] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.4), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0079] Using dimethyl 1,4-succinate and isosorbide as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0080] The first transesterification product and the second transesterification product (molar ratio of 1:0.5) were mixed and then antimony ethylene glycol (0.01 wt% based on the mass of the first and second transesterification products) was added, and a condensation reaction was carried out at 220°C and 30 KPa to obtain a pre-condensation product, and the pre-condensation product was subjected to a final polymerization reaction at 260°C and 100 Pa to obtain a polyethylene naphthalate copolymer.
[0081] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 1.08dL / g.
[0082] Example 6
[0083] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0084] Using dimethyl 1,4-succinate and 1,4-butanediol as raw materials (molar ratio of 1:1.1), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0085] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.3) are mixed, and tetrabutyl titanate (0.01wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 220°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 260°C and 100Pa to obtain a polyethylene naphthalate copolymer.
[0086] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.69dL / g.
[0087] Example 7
[0088] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0089] Using dimethyl 1,4-succinate and 1,4-butanediol as raw materials (molar ratio of 1:1.1), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 1,4-succinate), an ester exchange reaction was carried out at 200°C for 4h to obtain a second ester exchange product.
[0090] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.5) are mixed, and tetrabutyl titanate (0.01wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 220°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 250°C and 100Pa to obtain a polyethylene naphthalate copolymer.
[0091] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.92dL / g.
[0092] Example 8
[0093] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0094] Using 1,4-succinic acid dimethyl ester and 1,4-cyclohexanedimethanol as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on 1,4-succinic acid dimethyl ester), an ester exchange reaction was carried out at 200° C. for 4 hours to obtain a second ester exchange product.
[0095] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.3) are mixed, and tetrabutyl titanate (0.01wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 220°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 260°C and 100Pa to obtain a polyethylene naphthalate copolymer.
[0096] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.75dL / g.
[0097] Example 9
[0098] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0099] Using 1,4-succinic acid dimethyl ester and 1,4-cyclohexanedimethanol as raw materials (molar ratio of 1:1.05), in the presence of manganese acetate catalyst (0.01wt% based on 1,4-succinic acid dimethyl ester), an ester exchange reaction was carried out at 200° C. for 4 hours to obtain a second ester exchange product.
[0100] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.5) are mixed, and tetrabutyl titanate (0.01wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 220°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 260°C and 100Pa to obtain a polyethylene naphthalate copolymer.
[0101] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.81dL / g.
[0102] Example 10
[0103] Using dimethyl 2,6-naphthalene dicarboxylate and ethylene glycol as raw materials (molar ratio of 1:2.2), in the presence of manganese acetate catalyst (0.01wt% based on dimethyl 2,6-naphthalene dicarboxylate), an ester exchange reaction was carried out at 220°C for 4h to obtain a first ester exchange product.
[0104] Using 1,4-succinic acid dimethyl ester and 1,4-cyclohexanedimethanol as raw materials (molar ratio of 1:1.05), in the presence of cobalt acetate catalyst (0.01wt% based on 1,4-succinic acid dimethyl ester), an ester exchange reaction was carried out at 200° C. for 4 hours to obtain a second ester exchange product.
[0105] The first ester exchange product and the second ester exchange product (molar ratio of 1:0.5) are mixed, and tetrabutyl titanate (0.05wt% based on the mass of the first and second ester exchange products) is added, and a condensation reaction is carried out at 220°C and 30KPa to obtain a pre-condensation product. The pre-condensation product is subjected to a final polymerization reaction at 250°C and 80Pa to obtain a polyethylene naphthalate copolymer.
[0106] After testing, the specific test standard is ISO 1628-5, and the intrinsic viscosity of the product is 0.67dL / g.
[0107] It can be concluded from the above embodiments that the polyethylene naphthalate copolymer prepared by the technical solution provided in the present application has a suitable intrinsic viscosity; at the same time, according to the use of the polyethylene naphthalate copolymer, the polyethylene naphthalate copolymer can be modified by adjusting the raw materials and the reaction, and is widely used in the fields of special films, special fibers, and high-temperature resistant containers.
[0108] In summary, the present application provides a method for synthesizing polyethylene naphthalate copolymers, which includes: first esterification, second esterification, pre-condensation and final polymerization. The present application also provides an application of polyethylene naphthalate copolymers obtained by the above-mentioned synthesis method in special films, special fibers and high temperature resistant containers. In the technical scheme provided by the present application, the first esterification and the second esterification use 2,6-naphthalene dicarboxylic acid dimethyl ester and 1,4-succinic acid dimethyl ester as the carboxyl source of the esterification reaction, respectively, and do not use 2,6-naphthalene dicarboxylic acid as the reaction raw material. The raw material source of the carboxyl donor is wide and low in price, which effectively reduces the synthesis cost of polyethylene naphthalate copolymers; after further determination, the obtained polyethylene naphthalate copolymer has a characteristic viscosity of 0.6 to 1.5 dL / g, which has excellent performance. The synthesis method and application of a polyethylene naphthalate copolymer provided by the present application solve the technical defects of the high cost of synthetic raw materials in the prior art of polyethylene naphthalate copolymers.
[0109] The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. At the same time, other implementation methods can be derived from the above-mentioned embodiments, so that structural and logical replacements and changes can be made without departing from the scope of this disclosure.
[0110] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A method for synthesizing a polyethylene naphthalate copolymer, characterized in that: The synthetic method is: Step 1, first esterification: after mixing dimethyl 2,6-naphthalene dicarboxylate, ethylene glycol and a first catalyst, a first esterification reaction occurs to obtain a first transesterification product; Step 2, second esterification: After mixing dimethyl 1,4-succinate, diol and a second catalyst, a second esterification reaction occurs to obtain a second transesterification product; Step 3, pre-polycondensation: after mixing the first transesterification product and the second transesterification product, adding a third catalyst to cause a polycondensation reaction to obtain a pre-polycondensation product; Step 4: Final polymerization: The pre-polycondensation product undergoes a final polymerization reaction to obtain a polyethylene terephthalate copolymer product.
2. The synthesis method according to claim 1, characterized in that In step 2, the diol is selected from: isosorbide, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, tricyclodecane dimethanol, pentacyclopentadecanedimethanol, 2,6-decahydronaphthalene dimethanol, 1,5-decahydronaphthalene dimethanol, 2,3-decahydronaphthalene dimethanol, 2,3-norbornane dimethanol, 2,5-norbornane dimethanol and 1,3-adamantanedimethanol. One or more.
3. The synthesis method according to claim 1, characterized in that In terms of molar parts, the feed ratio of dimethyl 2,6-naphthalene dicarboxylate to ethylene glycol is 1:(2.0-2.4); And / or, the feeding amount of the first catalyst is 0.001wt% to 0.5wt% of dimethyl 2,6-naphthalene dicarboxylate; And / or, the temperature of the first transesterification reaction is 220°C to 260°C.
4. The synthesis method according to claim 1, characterized in that In terms of molar parts, the feed ratio of dimethyl 1,4-succinate to diol is 1:(1.0-1.2); And / or, the feeding amount of the second catalyst is 0.001wt% to 0.5wt% of 1,4-dimethyl succinate; And / or, the temperature of the second transesterification reaction is 160°C to 200°C.
5. The synthesis method according to claim 1, wherein the first catalyst is selected from any one or more of manganese acetate, cobalt acetate, zinc acetate, magnesium acetate and calcium acetate; And / or, the second catalyst is selected from: any one or more of manganese acetate, cobalt acetate, zinc acetate, magnesium acetate and calcium acetate.
6. The synthesis method according to claim 1, characterized in that In terms of molar parts, the feed ratio of the first transesterification product to the second transesterification product is 1:(0.1-1.0).
7. The synthesis method according to claim 1, characterized in that The third catalyst is selected from any one or more of antimony ethylene glycol, antimony trioxide and tetrabutyl titanate, and the feeding amount of the third catalyst is 0.001wt% to 0.5wt% of 1,4-dimethyl succinate.
8. The synthesis method according to claim 1, characterized in that The temperature of the polycondensation reaction is 220° C. to 260° C., and the pressure of the polycondensation reaction is 10 KPa to 50 KPa.
9. The synthesis method according to claim 1, characterized in that The temperature of the final polymerization reaction is 240° C. to 280° C., and the pressure of the final polymerization reaction is 0 Pa to 200 Pa.
10. Use of a polyethylene naphthalate copolymer prepared by the synthesis method according to any one of claims 1 to 9 in special films, special fibers and high temperature resistant containers.