Polysulfone, preparation method thereof and polysulfone product

Abstract

The invention relates to polysulfone and a preparation method thereof and a polysulfone product, and the preparation method of the polysulfone comprises the following steps: mixing 4, 4 '-dichlorodiphenyl sulfone, a bisphenol derivative monomer, a metal salt and a solvent, sequentially carrying out a salt forming reaction and a polymerization reaction, carrying out air exhaust during the salt forming reaction, and maintaining the pressure at negative pressure, the boiling point of the solvent is higher than the temperature of the salt-forming reaction, and the temperature of the salt-forming reaction is higher than the boiling point of water under negative pressure. The preparation method comprises the following steps: mixing the raw materials, sequentially carrying out a salt forming reaction and a polymerization reaction, controlling air exhaust during the salt forming reaction, maintaining negative pressure, and removing the byproduct water of the salt forming reaction into water vapor through air exhaust, so as to effectively avoid the interruption of the subsequent polymerization reaction caused by the water; and the boiling point of the solvent is controlled to be greater than the temperature of the salt forming reaction, so that the solvent is effectively prevented from being removed through air extraction, the polymerization reaction is ensured to be smoothly carried out, and the light transmittance of polysulfone can be effectively improved under the condition that a mixed solvent with a high boiling point and a low boiling point is not used.

Description

Technical Field

[0001] The present application relates to the field of synthesis technology, and in particular to a polysulfone and a preparation method thereof, and a polysulfone product. Background Art

[0002] Polysulfone is a high-performance engineering plastic with good heat resistance, chemical resistance and mechanical properties. In the polysulfone synthesis method, 4,4'-dichlorodiphenyl sulfone, bisphenol monomers and metal salts are used as raw materials and synthesized in solvents such as sulfolane. However, the light transmittance of polysulfone products obtained by the traditional polysulfone synthesis method is low.

[0003] Therefore, the traditional polysulfone synthesis method needs to be improved. Summary of the invention

[0004] Based on this, the present application provides a polysulfone that is easy to recycle and has high light transmittance, a preparation method thereof, and a polysulfone product.

[0005] The technical solution of this application to solve the above technical problems is as follows.

[0006] The present application provides a method for preparing polysulfone, comprising the following steps:

[0007] After mixing 4,4'-dichlorodiphenyl sulfone, bisphenol derivative monomer, metal salt and solvent, salt-forming reaction and polymerization reaction are carried out in sequence. During the salt-forming reaction, air is evacuated and maintained at negative pressure. The boiling point of the solvent is greater than the temperature of the salt-forming reaction, and the temperature of the salt-forming reaction is greater than the boiling point of water under the negative pressure.

[0008] In some of the embodiments, in the method for preparing polysulfone, the pressure F1 of the salt-forming reaction is -0.095MPa≤F1<0Mpa.

[0009] In some of the embodiments, in the method for preparing polysulfone, the temperature of the salt-forming reaction is 140°C to 230°C.

[0010] In some of the embodiments, in the method for preparing polysulfone, the pressure F2 of the polymerization reaction is -0.095MPa≤F2≤0.3Mpa.

[0011] In some of the embodiments, in the method for preparing polysulfone, the polymerization reaction temperature is 140°C to 230°C.

[0012] In some of the embodiments, in the method for preparing polysulfone, the bisphenol derivative monomer includes at least one of 4,4'-dihydroxydiphenylpropane, 4,4-dihydroxydiphenyl sulfone and 4,4'-biphenol.

[0013] In some embodiments, in the method for preparing polysulfone, the metal salt includes at least one of potassium carbonate, sodium carbonate, sodium hydroxide and potassium hydroxide.

[0014] In some of the embodiments, in the method for preparing polysulfone, the solvent includes at least one of sulfolane, N-methylpyrrolidone, dimethyl sulfoxide and N,N-dimethylethylamine.

[0015] In some of the embodiments, in the method for preparing polysulfone, the molar ratio of the bisphenol derivative monomer to the 4,4'-dichlorodiphenyl sulfone is 1:(0.9-1.1).

[0016] In some of the embodiments, in the method for preparing polysulfone, the molar ratio of the metal ion in the metal salt to the bisphenol derivative monomer is (2-6):1.

[0017] In some embodiments, in the method for preparing polysulfone, the method satisfies one of the following characteristics (1) to (3):

[0018] (1) The solvent is sulfolane, the pressure of the salt-forming reaction is -0.095 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 230° C.;

[0019] (2) The solvent is N-methylpyrrolidone, the pressure of the salt-forming reaction is -0.095 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 190° C.;

[0020] (3) The solvent is N,N-dimethylethylamine, the pressure of the salt-forming reaction is -0.08 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 160° C.

[0021] Accordingly, the present application provides a polysulfone prepared by the above-mentioned preparation method.

[0022] The present application also provides a polysulfone product, comprising the above-mentioned polysulfone.

[0023] Compared with the prior art, the preparation method of polysulfone of the present application has the following beneficial effects:

[0024] The preparation method of the polysulfone comprises the following steps: 4,4'-dichlorodiphenyl sulfone, a bisphenol derivative monomer, a metal salt and a solvent are mixed, and then a salt-forming reaction and a polymerization reaction are carried out in sequence. The hydroxyl group of the bisphenol derivative monomer and the metal salt generate hydroxyl salt and water. By controlling the exhaust gas during the salt-forming reaction and maintaining the pressure at a negative pressure, and the temperature of the salt-forming reaction is greater than the boiling point of water under negative pressure, the byproduct water is promptly vaporized into water vapor under negative pressure and separated from the reaction system by exhaust gas, thereby effectively preventing the byproduct water from causing the rupture of the ether bond generated by the polymerization reaction of the intermediate product hydroxyl salt and 4,4'-dichlorodiphenyl sulfone; and controlling the boiling point of the solvent to be greater than the temperature of the salt-forming reaction, effectively reducing the solvent from being removed by exhaust gas under negative pressure, thereby ensuring the smooth progress of the polymerization reaction, and thus achieving the effective improvement of the light transmittance of the polysulfone without using a mixed solvent of a high and low boiling point combination. DETAILED DESCRIPTION

[0025] References to embodiments of the present invention will now be provided in detail, examples of which are described below. Each example is provided as an explanation rather than a limitation of the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used in another embodiment to produce a further embodiment.

[0026] Therefore, it is intended that the present invention covers such modifications and variations that fall within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are obvious from the following detailed description. Those of ordinary skill in the art will appreciate that this discussion is only a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] The term "comprises", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprising one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. The indefinite articles "a kind of" and "an" before the elements or components of the present invention are not restrictive to the quantity requirements (i.e., the number of occurrences) of the elements or components. Therefore, "a" or "a kind of" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number clearly refers only to the singular form. The meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] The weight of the relevant components mentioned in the description of the embodiments of the present invention may not only refer to the specific content of each component, but also indicate the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the description of the embodiments of the present invention, it is within the scope disclosed in the description of the embodiments of the present invention. Specifically, the weight described in the description of the embodiments of the present invention may be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0030] Except as shown in the operating examples or otherwise indicated, all numbers used in the specification and claims to indicate the amount of ingredients, physicochemical properties, etc. are understood to be adjusted by the term "about" in all cases. For example, therefore, unless otherwise indicated, the numerical parameters listed in the above specification and the attached claims are approximate values, and those skilled in the art can use the teachings disclosed herein to seek to obtain the desired properties and appropriately change these approximate values. The use of numerical ranges expressed as endpoints includes all numbers within the range and any range within the range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4 and 5, etc.

[0031] The technicians of this application found in their research that the reason why the transmittance of the polysulfone product obtained by the traditional polysulfone synthesis method is low is that the byproduct water produced during the reaction process will cause the transmittance of the obtained polysulfone product to be low. The solution is to use a high-low boiling point mixed system of low boiling point solvent with water and high boiling point solvent reaction, such as adding low boiling point solvents such as toluene, N, N-dimethylformamide and N, N-dimethylacetamide to the high boiling point solvent cyclopentane to achieve the effect of removing water, but this high-low boiling point mixed system is complicated and brings difficulties to the subsequent solvent recovery; or use a single solvent, and use the solvent and water to azeotropy to achieve the effect of removing water, but the azeotropic effect of carrying water is poor, and water cannot be removed in time, resulting in the low transmittance of the obtained polysulfone product.

[0032] An embodiment of the present application provides a method for preparing polysulfone, comprising the following steps:

[0033] After mixing 4,4'-dichlorodiphenyl sulfone, bisphenol derivative monomer, metal salt and solvent, salt-forming reaction and polymerization reaction are carried out in sequence. During the salt-forming reaction, air is evacuated and maintained at negative pressure. The boiling point of the solvent is greater than the temperature of the salt-forming reaction, and the temperature of the salt-forming reaction is greater than the boiling point of water under negative pressure.

[0034] The preparation method of the polysulfone is as follows: 4,4'-dichlorodiphenyl sulfone, a bisphenol derivative monomer, a metal salt and a solvent are mixed, and then salt-forming reaction and polymerization reaction are carried out in sequence. The hydroxyl group of the bisphenol derivative monomer and the metal salt generate hydroxyl salt and water. By controlling the exhaust gas during the salt-forming reaction and maintaining the negative pressure, and the temperature of the salt-forming reaction is greater than the boiling point of water under negative pressure, the by-product water is removed as water vapor through exhaust gas, and the by-product water is effectively prevented from causing the by-product water to cause the ether bond generated by the polymerization reaction of the intermediate product hydroxyl salt and 4,4'-dichlorodiphenyl sulfone to break; and the boiling point of the solvent is controlled to be greater than the temperature of the salt-forming reaction, and the solvent is effectively prevented from being removed through exhaust gas under negative pressure conditions, thereby ensuring the smooth progress of the polymerization reaction, thereby achieving the effective improvement of the light transmittance of the polysulfone without using a mixed solvent of a high and low boiling point combination.

[0035] In some of the examples, in the method for preparing polysulfone, the pressure F1 of the salt-forming reaction is -0.095 MPa≤F1<0 MPa.

[0036] It can be understood that specific negative pressure conditions can be controlled by using a vacuum method.

[0037] In some of the examples, in the preparation method of polysulfone, a vacuum operating device is provided in the reaction vessel, and the pressure in the vacuum operating device is controlled to be negative pressure, so that by-product water is effectively discharged, thereby avoiding interference of the by-product water with the polysulfone synthesis reaction.

[0038] It is further understood that the pressure of the salt-forming reaction is less than 0 MPa, including but not limited to -0.01 MPa, -0.02 MPa, -0.03 MPa, -0.04 MPa, -0.05 MPa, -0.06 MPa, -0.07 MPa, -0.08 MPa, -0.09 MPa, -0.095 MPa. In some examples, any two of these point values ​​may be used as end values ​​within the range, the same below.

[0039] Optionally, the pressure F1 of the salt-forming reaction is -0.07MPa<F1≤-0.02Mpa.

[0040] In some of the examples, in the method for preparing polysulfone, the temperature of the salt-forming reaction is 140°C to 230°C.

[0041] It is understood that the temperature of the salt-forming reaction includes but is not limited to 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, and 230°C.

[0042] Optionally, the temperature of the salt-forming reaction is 160°C to 190°C.

[0043] In some of the examples, in the method for preparing polysulfone, the time for the salt-forming reaction is 2 h to 6 h.

[0044] It is understood that the time for the salt-forming reaction includes but is not limited to 2 h, 3 h, 4 h, 5 h, and 6 h.

[0045] Optionally, the salt-forming reaction time is 3 h to 5 h.

[0046] In some of these examples, in the method for preparing polysulfone, the boiling point of the solvent under negative pressure is greater than the temperature of the salt-forming reaction.

[0047] In some of the examples, in the method for preparing polysulfone, the pressure F2 of the polymerization reaction is -0.095MPa≤F2≤0.3Mpa.

[0048] It can be understood that the pressure F2 of the polymerization reaction includes but is not limited to 0.1MPa, 0.2MPa, 0.3MPa, 0MPa, -0.01MPa, -0.02MPa, -0.03MPa, -0.04MPa, -0.05MPa, -0.06MPa, -0.07MPa, -0.08MPa, -0.09MPa, and -0.095MPa.

[0049] It can be further understood that 0 MPa is normal pressure, that is, the polymerization reaction can be carried out under normal pressure, positive pressure or negative pressure.

[0050] Optionally, the polymerization reaction pressure F2 is -0.09MPa≤F2≤0Mpa.

[0051] In some of the examples, in the method for preparing polysulfone, the polymerization reaction temperature is 140°C to 230°C.

[0052] It is understood that the temperature of the polymerization reaction includes but is not limited to 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, and 230°C.

[0053] Optionally, the polymerization temperature is 160°C to 200°C.

[0054] In some of the examples, in the method for preparing polysulfone, the polymerization reaction time is 5 h to 15 h.

[0055] It will be appreciated that the polymerization reaction time includes, but is not limited to, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, and 15 h.

[0056] Optionally, the polymerization reaction time is 6 h to 12 h.

[0057] On the basis of controlling the pressure of the salt-forming reaction and the polymerization reaction, further controlling the temperature and time of the salt-forming reaction and the polymerization reaction can further improve the transmittance of the polysulfone product and effectively improve the reaction efficiency.

[0058] In some of the examples, in the method for preparing polysulfone, the bisphenol derivative monomer includes at least one of 4,4'-dihydroxydiphenylpropane (bisphenol A), 4,4-dihydroxydiphenyl sulfone (bisphenol S) and 4,4'-biphenol (BP).

[0059] In some of the examples, in the method for preparing polysulfone, the molar ratio of the bisphenol derivative monomer to 4,4'-dichlorodiphenyl sulfone is 1:(0.9-1.1).

[0060] It is understood that the molar ratio of the bisphenol derivative monomer to 4,4'-dichlorodiphenyl sulfone includes but is not limited to 0.9:1, 1:1, 1:1.01, 1:1.02, 1:1.03, 1:1.05, 1:1.06, 1:1.08, 1:1.09, and 1:1.1.

[0061] Optionally, the molar ratio of the bisphenol derivative monomer to 4,4'-dichlorodiphenyl sulfone is 1:(1-1.1).

[0062] It is understood that metal salts include but are not limited to sodium salts, potassium salts, cesium salts, and metal salts include but are not limited to carbonates, bicarbonates, and hydroxides of metal elements.

[0063] In some of the examples, in the method for preparing polysulfone, the metal salt includes at least one of potassium carbonate, sodium carbonate, sodium hydroxide and potassium hydroxide.

[0064] In some of the examples, in the method for preparing polysulfone, the molar ratio of the metal ion in the metal salt to the bisphenol derivative monomer is (2-6):1.

[0065] It is understood that the molar ratio of the metal ion in the metal salt to the bisphenol derivative monomer includes but is not limited to 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 3:1, 4:1, 5:1, and 6:1.

[0066] Optionally, the molar ratio of the metal ion in the metal salt to the bisphenol derivative monomer is (2-2.5):1.

[0067] In some of the examples, in the method for preparing polysulfone, the solvent includes at least one of sulfolane, N-methylpyrrolidone (NMP), dimethyl sulfoxide, N,N-dimethylethylamine (DMAc), and the like.

[0068] It can be understood that the boiling point of sulfolane is 285°C, the boiling point of N-methylpyrrolidone is 202°C, and the boiling point of N,N-dimethylethylamine is 166°C; when the solvent includes sulfolane, the temperature of the salt-forming reaction is less than 285°C; when the solvent includes N-methylpyrrolidone, the temperature of the salt-forming reaction is less than 202°C; when the solvent includes N,N-dimethylethylamine, the temperature of the salt-forming reaction is less than 166°C.

[0069] In some of the examples, in the method for preparing polysulfone, the solvent is sulfolane, the pressure of the salt-forming reaction is -0.095 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 230° C.

[0070] Optionally, in the method for preparing polysulfone, the solvent is sulfolane, the pressure of the salt-forming reaction is -0.09 MPa to -0.05 MPa, and the temperature of the salt-forming reaction is 180° C. to 230° C.

[0071] Furthermore, in the preparation method of polysulfone, the solvent is sulfolane, the pressure of the salt-forming reaction is -0.09MPa to -0.06MPa, and the temperature of the salt-forming reaction is 160°C to 200°C.

[0072] In some of the examples, in the method for preparing polysulfone, the solvent is N-methylpyrrolidone, the pressure of the salt-forming reaction is -0.095 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 190° C.

[0073] Optionally, in the method for preparing polysulfone, the solvent is N-methylpyrrolidone, the pressure of the salt-forming reaction is -0.06MPa to -0.02MPa, and the temperature of the salt-forming reaction is 150°C to 190°C.

[0074] Optionally, in the method for preparing polysulfone, the solvent is N-methylpyrrolidone, the pressure of the salt-forming reaction is -0.05 MPa to -0.03 MPa, and the temperature of the salt-forming reaction is 160° C. to 180° C.

[0075] Furthermore, in the preparation method of polysulfone, the solvent is N-methylpyrrolidone, the pressure of the salt-forming reaction is -0.04 MPa, and the temperature of the salt-forming reaction is 170°C.

[0076] In some of the examples, in the method for preparing polysulfone, the solvent is N,N-dimethylethylamine, the pressure of the salt-forming reaction is -0.08MPa to -0.005MPa, and the temperature of the salt-forming reaction is 140°C to 160°C.

[0077] Optionally, in the method for preparing polysulfone, the solvent is N,N-dimethylethylamine, the pressure of the salt-forming reaction is -0.03MPa to -0.01MPa, and the temperature of the salt-forming reaction is 140°C to 160°C.

[0078] Optionally, in the preparation method of polysulfone, the solvent is N,N-dimethylethylamine, the pressure of the salt-forming reaction is -0.02MPa to -0.01MPa, and the temperature of the salt-forming reaction is 150°C to 160°C.

[0079] Furthermore, in the preparation method of polysulfone, the solvent is N,N-dimethylethylamine, the pressure of the salt-forming reaction is -0.02 MPa, and the temperature of the salt-forming reaction is 160°C.

[0080] In some of the examples, the preparation method of polysulfone further includes a step of post-treating the reaction solution after the polymerization reaction is completed, and the post-treating includes:

[0081] The reaction liquid after the polymerization reaction is subjected to solid-liquid separation, and the filtrate is taken for crystallization.

[0082] Furthermore, the crystallization solvent includes water.

[0083] It is understood that, in addition to water, other organic solvents or mixed solvents may be used as the solvent for crystallization.

[0084] Further, the organic solvent includes, but is not limited to, sulfolane, N-methylpyrrolidone, dimethyl sulfoxide and N,N-dimethylethylamine.

[0085] In some of the examples, in the preparation method of polysulfone, the post-treatment may also be: directly crystallizing the reaction liquid after the polymerization reaction, collecting the solid, washing it with a solvent, and drying it.

[0086] One embodiment of the present application provides a polysulfone prepared by the above-mentioned preparation method.

[0087] One embodiment of the present application provides the use of the above polysulfone in the preparation of a polysulfone product. Another embodiment of the present application provides a polysulfone product, the material of which includes the above polysulfone.

[0088] The polysulfone is used to prepare polysulfone products, which not only have heat resistance, chemical resistance and good mechanical properties, but also can give the polysulfone products higher light transmittance.

[0089] In some embodiments, the polysulfone products include, but are not limited to, electronics, electrical appliances, machinery, automobiles, and medical devices.

[0090] In some embodiments, the material of the polysulfone product may be the above-mentioned polysulfone, that is, the polysulfone product is directly prepared by using the above-mentioned polysulfone. In other embodiments, the material of the polysulfone product may include other materials in addition to the above-mentioned polysulfone.

[0091] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0092] The raw materials used in the examples and comparative examples are commercially available.

[0093] Example 1

[0094] In a polymerization kettle with a fractionation column, a condenser, a solvent receiving tank, a liquid return loop and a vacuum system, 90 kg of solvent sulfolane, 90 mol of bisphenol A (4,4'-dihydroxydiphenylpropane), 91 mol of 4,4'-dichlorodiphenyl sulfone and 99 mol of potassium carbonate were added, the air in the polymerization kettle was replaced with nitrogen, the pressure of the vacuum system was set to -0.07 MPa for continuous exhaust, the temperature was raised to 190°C, and the salt-forming reaction was carried out for 3 hours in sequence, and the polymerization reaction stage was entered when no water was produced for 3 hours. The reaction liquid was filtered, the filtrate was crystallized with water, the crystal precipitate was washed with water, and then dried, and the melt index of the obtained polysulfone was 3 g / 10 min.

[0095] Example 2

[0096] In a polymerization kettle with a fractionation column, a condenser, a solvent receiving tank, a liquid return loop and a vacuum system, 90 kg of solvent N, N-dimethylethylamine, 90 mol of bisphenol A, 91 mol of 4, 4'-dichlorodiphenyl sulfone and 99 mol of potassium carbonate were added, the air in the polymerization kettle was replaced with nitrogen, the pressure of the vacuum system was set to -0.02 MPa for continuous exhaust, the temperature was raised to 160°C, and when no water was produced after 5 hours of salt formation reaction, the pressure of the vacuum system was set to 0 MPa, the temperature was raised to 166°C, and the polymerization reaction was carried out for 7 hours. The reaction liquid was filtered, the filtrate was crystallized with water, the crystal precipitate was washed with water, and then dried, and the melt index of the obtained polysulfone was 3 g / 10 min.

[0097] Example 3

[0098] In a polymerization kettle with a fractionation column, a condenser, a solvent receiving tank, a liquid return loop and a vacuum system, 90 kg of solvent N-methylpyrrolidone, 90 mol of bisphenol A, 91 mol of 4,4'-dichlorodiphenyl sulfone and 99 mol of potassium carbonate were added, the air in the polymerization kettle was replaced with nitrogen, the pressure of the vacuum system was set to -0.04 MPa for continuous exhaust, the temperature was raised to 170°C, and the salt-forming reaction was carried out for 3 hours in sequence, and the polymerization reaction stage was entered for 4 hours when no water was produced. The reaction liquid was filtered, the filtrate was crystallized with water, the crystal precipitate was washed with water, and then dried, and the melt index of the obtained polysulfone was 3.2 g / 10 min.

[0099] Example 4

[0100] In a polymerization kettle with a fractionation column, a condenser, a solvent receiving tank, a liquid return loop and a vacuum system, 90 kg of solvent N, N-dimethylethylamine, 90 mol of BP (4, 4'-biphenyldiphenol), 91 mol of 4, 4'-dichlorodiphenyl sulfone and 99 mol of potassium carbonate were added, the air in the polymerization kettle was replaced with nitrogen, the pressure of the vacuum system was set to -0.02 MPa for continuous evacuation, the temperature was raised to 160°C, and the salt-forming reaction was carried out for 4 hours. When no water was produced, the pressure of the vacuum system was set to 0 MPa, the temperature was raised to 166°C, and the polymerization reaction was carried out for 4 hours. The reaction liquid was filtered, the filtrate was crystallized with water, the crystal precipitate was washed with water, and then dried, and the melt index of the obtained polysulfone was 20.2 g / 10 min.

[0101] Example 5

[0102] In a polymerization kettle with a fractionation column, a condenser, a solvent receiving tank, a liquid return loop and a vacuum system, 90 kg of solvent sulfolane, 90 mol of BP, 91 mol of 4,4'-dichlorodiphenyl sulfone and 99 mol of potassium carbonate were added, the air in the polymerization kettle was replaced with nitrogen, the pressure of the vacuum system was set to -0.07 MPa for continuous exhaust, the temperature was raised to 190°C, and the salt-forming reaction was carried out for 3 hours in sequence, and the polymerization reaction stage was entered for 3 hours when no water was produced. The reaction liquid was filtered, the filtrate was taken for crystallization with water, the crystal precipitate was taken for water washing, and then dried, and the melt index of the obtained polysulfone was 20 g / 10 min.

[0103] Example 6

[0104] In a polymerization kettle with a fractionation column, a solvent receiving tank, a liquid return loop and a vacuum system, 90 kg of solvent sulfolane, 90 mol of BP, 91 mol of 4,4-dihydroxydiphenyl sulfone (bisphenol S) and 99 mol of potassium carbonate were added, the air in the polymerization kettle was replaced with nitrogen, the pressure of the vacuum system was set to -0.07 MPa for continuous exhaust, the temperature was raised to 190°C, and the salt-forming reaction was carried out for 4 hours. When no water was produced, the pressure of the vacuum system was set to -0.065 MPa, the temperature was raised to 195°C, and the polymerization reaction was carried out for 2 hours. The reaction liquid was filtered, the filtrate was crystallized with water, the crystal precipitate was washed with water, and then dried, and the melt index of the obtained polysulfone was 13 g / 10 min.

[0105] Example 7

[0106] It is basically the same as Example 1, except that in Example 7, the pressure of the vacuum system is set to -0.07Mpa, the temperature is raised to 190°C, and the salt-forming reaction is carried out for 3 hours. Then, the pressure of the vacuum system is set to 0Mpa, the temperature is 190°C, and the polymerization reaction is carried out for 3 hours.

[0107] Comparative Example 1

[0108] The method is basically the same as Example 1, except that the raw materials of Example 1 further include 5 kg of xylene. The salt-forming reaction and the polymerization reaction are carried out in sequence under the conditions of 0 MPa and 190° C., and the reaction is carried out together for 11 hours. The melt index of the obtained polysulfone is 3.1 g / 10 min.

[0109] Comparative Example 2

[0110] It is basically the same as Example 2, except that, in Comparative Example 2, the salt-forming reaction and the polymerization reaction are respectively carried out under 0 MPa conditions, the salt-forming reaction time is 6 h, the polymerization reaction time is 5 h, the salt-forming reaction and the polymerization reaction temperature and other parameters are the same as Example 2, and the melt index of the obtained polysulfone is 3.1 g / 10 min.

[0111] Comparative Example 3

[0112] It is basically the same as Example 3, except that the raw materials of Comparative Example 3 also include 5 kg of xylene, and the salt-forming reaction and the polymerization reaction are carried out in sequence under 0 MPa conditions, and the reaction is carried out together for 8 hours. The temperature and other parameters of the salt-forming reaction and the polymerization reaction are the same as those of Example 3, and the melt index of the obtained polysulfone is 3 g / 10 min.

[0113] Comparative Example 4

[0114] It is basically the same as Example 4, except that, in Example 4, the salt-forming reaction and the polymerization reaction are respectively carried out under 0 MPa conditions, the polymerization reaction time is 5 h, the temperature and other parameters of the salt-forming reaction and the polymerization reaction are the same as those in Example 4, and the melt index of the obtained polysulfone is 20.2 g / 10 min.

[0115] Comparative Example 5

[0116] It is basically the same as Example 5, except that the raw materials of Comparative Example 5 also include 5 kg of xylene, and the salt-forming reaction and the polymerization reaction are respectively carried out under 0 MPa conditions. The salt-forming reaction time is 5 h, and the polymerization reaction time is 4 h. The temperature and other parameters of the salt-forming reaction and the polymerization reaction are the same as those of Example 5. The melt index of the obtained polysulfone is 20.5 g / 10 min.

[0117] Comparative Example 6

[0118] It is basically the same as Example 6, except that the raw materials of Comparative Example 6 also include 5 kg of xylene, and the salt-forming reaction and the polymerization reaction are respectively carried out under 0 MPa conditions, the salt-forming reaction time is 6 h, the polymerization reaction temperature is 220° C., the polymerization reaction time is 7 h, and the other parameters are the same as Example 6. The melt index of the obtained polysulfone is 13.7 g / 10 min.

[0119] The main raw materials and parameters of each embodiment and comparative example are shown in Table 1.

[0120] Table 1

[0121]

[0122]

[0123] Among them, the salt-forming temperature refers to the temperature of the salt-forming reaction, the salt-forming pressure refers to the pressure of the salt-forming reaction, the salt-forming time refers to the time of the salt-forming reaction, the polymerization temperature refers to the temperature of the polymerization reaction, the polymerization pressure refers to the pressure of the polymerization reaction, and the total salt-forming polymerization time refers to the total time of the salt-forming reaction and the polymerization reaction.

[0124] The polysulfones prepared in each embodiment and comparative example were respectively injection molded into sheets with a thickness of 1.6 mm, and the light transmittance was measured. The test results of embodiments 1 to 3 and comparative examples 1 to 3 are shown in Table 2:

[0125] Table 2

[0126]

[0127] It can be seen from Table 2 that when the bisphenol derivative monomer is bisphenol A, compared with Comparative Examples 1 to 3, Examples 1 to 3 perform salt-forming reactions under negative pressure conditions, and the resulting polysulfones have higher light transmittance.

[0128] The test results of Examples 4 to 5 and Comparative Examples 4 to 5 are shown in Table 3:

[0129] Table 3

[0130]

[0131]

[0132] It can be seen from Table 3 that when the bisphenol derivative monomer is BP, compared with Comparative Examples 4-5, Examples 4-5 perform salt-forming reactions under negative pressure conditions, and the light transmittance of the obtained polysulfone is higher.

[0133] The test results of Example 6 and Comparative Example 6 are shown in Table 4:

[0134] Table 4

[0135] Group Example 6 Light transmittance (%) 83 Group Comparative Example 6 Light transmittance (%) 81

[0136] It can be seen from Table 4 that when the bisphenol derivative monomer is bisphenol S, compared with Comparative Example 6, Example 6 performs salt-forming reaction under negative pressure conditions, and the light transmittance of the obtained polysulfone is higher.

[0137] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0138] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for preparing polysulfone, characterized in that: The following steps are involved: After mixing 4,4'-dichlorodiphenyl sulfone, bisphenol derivative monomer, metal salt and solvent, an inert gas such as nitrogen is introduced to sequentially carry out salt-forming reaction and polymerization reaction. During the salt-forming reaction, air is evacuated and maintained at a negative pressure. The boiling point of the solvent is greater than the temperature of the salt-forming reaction, and the temperature of the salt-forming reaction is greater than the boiling point of water under the negative pressure.

2. The preparation method according to claim 1, characterized in that The pressure F1 of the salt-forming reaction is -0.095MPa≤F1<0Mpa.

3. The preparation method according to claim 1, characterized in that: The temperature of the salt-forming reaction is 140°C to 230°C.

4. The preparation method according to claim 1, characterized in that: The pressure F2 of the polymerization reaction is -0.095MPa≤F2≤0.3Mpa.

5. The preparation method according to claim 1, characterized in that: The polymerization reaction temperature is 140°C to 230°C.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The preparation method satisfies at least one of the following characteristics (1) to (2): (1) The bisphenol derivative monomer includes at least one of 4,4'-dihydroxydiphenyl propane, 4,4-dihydroxydiphenyl sulfone and 4,4'-biphenyl diphenol; (2) the metal salt comprises at least one of potassium carbonate, sodium carbonate, sodium hydroxide and potassium hydroxide; (3) The solvent includes at least one of sulfolane, N-methylpyrrolidone, dimethyl sulfoxide and N,N-dimethylethylamine.

7. The preparation method according to any one of claims 1 to 5, characterized in that: The preparation method satisfies at least one of the following characteristics (1) to (2): (1) The molar ratio of the bisphenol derivative monomer to the 4,4'-dichlorodiphenyl sulfone is 1:(0.9-1.1); (2) The molar ratio of the metal ion in the metal salt to the bisphenol derivative monomer is (2-6):

1.

8. The preparation method according to any one of claims 1 to 5, characterized in that: The preparation method satisfies one of the following characteristics (1) to (3): (1) The solvent is sulfolane, the pressure of the salt-forming reaction is -0.095 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 230° C.; (2) The solvent is N-methylpyrrolidone, the pressure of the salt-forming reaction is -0.095 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 190° C.; (3) The solvent is N,N-dimethylethylamine, the pressure of the salt-forming reaction is -0.08 MPa to -0.005 MPa, and the temperature of the salt-forming reaction is 140° C. to 160° C.

9. A polysulfone, characterized in that The preparation method is described in any one of claims 1 to 8.

10. A polysulfone product, characterized in that: Comprising the polysulfone as claimed in claim 9.

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