Polyesterimide resin as well as preparation method and application thereof

Abstract

The invention discloses polyesterimide resin as well as a preparation method and application thereof. The polyesterimide resin is prepared from the following raw materials: iminodiacetic acid dialkyl ester, unsaturated binary acid, saturated binary anhydride, amino-containing aromatic binary acid and a monohydric alcohol end-capping reagent, the polyesterimide resin disclosed by the invention can obtain high-content and uniformly-distributed imino groups in a main chain, provides more uniform cross-linking sites, is beneficial to mixing and dissolving with organic resins such as epoxy, alcohol acid and vinyl, and can also form more chemical bonds among molecular chains of the polyesterimide resin, so that the overall performance of the material is improved, and the service life of the polyesterimide resin is prolonged. Meanwhile, the polyesterimide resin disclosed by the invention has the advantage of controllable molecular chain length, and the flowability and permeability are improved; practice shows that the polyesterimide resin disclosed by the invention has relatively excellent mechanical property, electrical property, heat resistance and degradation resistance.

Description

Technical Field

[0001] The present invention relates to the field of electronics and electrical equipment, in particular to a resin material used in the field of electronics and electrical equipment, and specifically to a polyester imide resin and a preparation method and application thereof. Background Art

[0002] Unsaturated polyester imine resin is a kind of unsaturated polyester polymer containing imine structural units. Its molecular structure is characterized by the imine structure embedded in the macromolecular chain, which gives the material good thermal stability and mechanical properties. Due to its outstanding performance in heat resistance, electrical insulation performance and mechanical strength, unsaturated polyester imine resin has been widely used in the field of electronics and electrical, for example, it can be used in the manufacture of products such as flexible printed circuit boards, insulating paints, laminates, etc. At present, the main technical approaches for synthesizing unsaturated polyester imine resins include: introducing trimellitic anhydride and diamine in the later synthesis stage of unsaturated polyester, introducing a capping agent containing an imine structure (such as the reaction product of phthalic anhydride and monoethanolamine) in the synthesis process of unsaturated polyester, and using isocyanate technical solutions. However, these methods usually result in low imino content, uneven distribution or difficulty in control, which makes the performance stability of the synthesized unsaturated polyester imine resin insufficient, especially in terms of strength, heat resistance and flame retardancy, making it difficult to meet further product development needs and difficult to prepare high-quality casting resins.

[0003] It should be noted that the information disclosed in the above background technology section is only used to understand the background of the present application, so the background technology section of the present invention may contain background information about the problem or environment of the present invention, but not necessarily describe the prior art. Therefore, the content contained in the background technology section is not an admission of the applicant to the prior art. Summary of the invention

[0004] The object of the present invention is to overcome one or more deficiencies in the prior art and to provide an improved polyesterimide resin having excellent properties in terms of strength, heat resistance and flame retardancy.

[0005] The invention also provides a preparation method of the polyester imine resin and application of the polyester imine resin in preparing casting resin.

[0006] In order to achieve the above object, a technical solution adopted by the present invention is:

[0007] A polyester imine resin, wherein the raw materials of the polyester imine resin include:

[0008] (a) Compound represented by formula (I)

[0009] In formula (I), R1 and R2 are independently C 1-8 Alkylene;

[0010] (b) unsaturated dibasic acids;

[0011] (c) saturated dibasic acid anhydrides;

[0012] (d) Compound represented by formula (II)

[0013] In formula (II), R3 and R4 are independently selected from substituted C 6-12 The aromatic ring, the substituents used include carboxyl, and selected from H, C 1-6 Alkyl and C 1-6 one or more of the alkoxy groups;

[0014] (e) Compound represented by formula (III)

[0015] In formula (III), one of R5 and R6 is a hydroxyl group, and the other is selected from H, C 1-6 Alkyl or C 1-6 Alkoxy.

[0016] According to some preferred aspects of the present invention, the molar ratio of the compound represented by formula (I), the unsaturated dibasic acid, the saturated dibasic acid anhydride, the compound represented by formula (II) and the compound represented by formula (III) is 1:0.3-0.5:0.4-0.6:0.05-0.15:0.05-0.25.

[0017] In some embodiments of the present invention, the method for preparing the compound represented by formula (I) comprises: reacting diethyl iminodiacetate with C 1-8 Alkylene glycol is prepared by transesterification reaction, wherein the C 1-8 The alkylene glycol is selected from the following structures: Furthermore, the C 1-8 The alkylene glycol is preferably 1,2-propylene glycol or neopentyl glycol.

[0018] Furthermore, the embodiment of preparing the compound represented by formula (I) comprises: adding diethyl iminodiacetate, C 1-8 Alkylene glycol and catalyst (such as zinc acetate, etc.), open the condensation reflux device, raise the temperature to 120°C, after part of the raw material solid components are dissolved, start stirring, and then slowly raise the temperature to 170-180°C to start ester exchange, reflux reaction for 0.1-2 hours, then remove ethanol by distillation, and the ethanol to be removed and collected reaches more than 99% of the theoretical value, continue heating and control the reaction temperature at 180-205°C, cool to 120°C, filter out solid impurity particles with residual heat through a Buchner funnel, and gradually cool the filtrate to -5~0°C while stirring, and filter out the crystalline product, which is the compound represented by formula (I).

[0019] In some embodiments of the present invention, R1 and R2 are independently selected from

[0020] According to some specific aspects of the present invention, the compound represented by formula (I) can be iminodiacetic acid bis-β-(1,2-propylene glycol), iminodiacetic acid bis-β-(neopentyl glycol), etc.

[0021] In some embodiments of the present invention, the unsaturated dibasic acid includes but is not limited to maleic anhydride and / or fumaric acid.

[0022] In some embodiments of the present invention, the saturated dibasic acid anhydride includes but is not limited to phthalic anhydride and / or methyltetrahydrophthalic anhydride.

[0023] In some embodiments of the present invention, in formula (II), R3 and R4 are independently selected from R7 is selected from H, methyl, ethyl, propyl or methoxy.

[0024] In some embodiments of the present invention, in formula (III), R5 is a hydroxyl group substituted at the para position, and R6 is selected from H, methyl, ethyl, propyl or methoxy.

[0025] According to some specific aspects of the present invention, the compound represented by formula (II) is an aromatic dibasic acid containing an amino group, and may be 4,4'-iminodibenzoic acid.

[0026] According to some specific aspects of the present invention, the compound represented by formula (III) is a monohydric alcohol capping agent, which may be 4-maleimidophenol.

[0027] In some embodiments of the present invention, the raw material of the polyesterimine resin further comprises (f) an esterification catalyst and (g) a polymerization inhibitor.

[0028] Furthermore, the molar ratio of the esterification catalyst to the compound represented by formula (I) is 0.02-0.08:1.

[0029] Furthermore, the addition amount of the polymerization inhibitor is 0.05%-0.5% of the total mass of the raw material of the polyesterimide resin.

[0030] Furthermore, the esterification catalyst is a combination of one or more selected from sulfuric acid, p-toluenesulfonic acid, and ion exchange resin, preferably p-toluenesulfonic acid.

[0031] Furthermore, the polymerization inhibitor is a combination of one or more selected from hydroquinone, nitrobenzene, tert-butylcatechol, and p-hydroxyanisole.

[0032] Furthermore, the reaction formula for preparing the compound represented by formula (I) is as follows (the example is given for the compound represented by formula (I) in which R1 and R2 are the same):

[0033]

[0034] The following is an example of the reaction process of polyester imide resin and the structure obtained by the reaction, taking the unsaturated dibasic acid as maleic anhydride (maleic anhydride), the saturated dibasic acid anhydride as phthalic anhydride, the compound represented by formula (II) as 4,4'-iminodibenzoic acid, and the compound represented by formula (III) as 4-maleimidophenol as an example:

[0035]

[0036] Furthermore, when R' is When, an exemplary structure of the polyesterimide resin is as follows:

[0037]

[0038] Furthermore, when R' is When, an exemplary structure of the polyesterimide resin is as follows:

[0039]

[0040] The structure of the polyesterimide resin is only an exemplary structure, which only exemplifies the combination of the raw materials in which the hydroxyl group reacts with the carboxyl group or the acid anhydride to generate the ester group; in the actual reaction process, following the principle of the hydroxyl group reacting with the carboxyl group or the acid anhydride to generate the ester group, the reaction order or combination mode of each compound may be different, which is specifically manifested in that the repeating units where a, b, and c are located may have different combinations. For example, the compound shown in formula (I) can react with maleic anhydride (maleic anhydride), 4,4'-imidodibenzoic acid, or phthalic anhydride. Therefore, there are many situations in the structure after the reaction between them.

[0041] Another technical solution provided by the present invention is a method for preparing the polyesterimide resin described above, the method comprising: mixing the other components of the raw materials of the polyesterimide resin except the polymerization inhibitor, heating under a protective atmosphere, reacting, and selectively removing the generated water at each stage of the reaction, when the acid value reaches 30-40 mgKOH / g, performing vacuum reduced pressure distillation and continuing the reaction, when the acid value decreases to 5-15 mgKOH / g, cooling, adding the polymerization inhibitor, and mixing.

[0042] Furthermore, the protective atmosphere can be formed by introducing nitrogen or an inert gas, wherein the inert gas includes helium, argon, etc.

[0043] Further, the temperature is raised to 110-130° C. under a protective atmosphere.

[0044] Furthermore, the implementation method of preparing the polyesterimide resin includes: mixing the other ingredients of the raw materials of the polyesterimide resin except the polymerization inhibitor, heating to 110-130° C. under a protective atmosphere, starting stirring after some solid components of the raw materials are dissolved, and then slowly heating to 155-175° C. to start generating byproduct water, esterification reflux reaction for 0.1-2 hours, starting distillation and dehydration to carry out esterification condensation, and after the acid value reaches 30-40 mgKOH / g, starting vacuuming and performing reduced pressure distillation to continue the condensation reaction, reacting until the acid value decreases to 5-15 mgKOH / g, cooling to 125-135° C., adding the polymerization inhibitor, stirring, and continuing to cool to below 80° C. to filter and discharge the material to obtain the polyesterimide resin.

[0045] Another technical solution provided by the present invention is a use of the polyesterimide resin described above in the preparation of casting resin.

[0046] Further, the casting resin comprises component A and component B;

[0047] The component A comprises the polyester imine resin described above, a vinyl crosslinking agent and an optionally included polymerization inhibitor;

[0048] The second component comprises an initiator, a plasticizer and an optionally contained accelerator.

[0049] In some embodiments of the present invention, in the component A, by weight, 100 parts of polyesterimide resin, 30-60 parts of vinyl crosslinking agent and 0-1 part of polymerization inhibitor.

[0050] In some embodiments of the present invention, the vinyl-containing cross-linking agent may be vinyltoluene.

[0051] In some embodiments of the present invention, in terms of weight, the component B comprises 1-5 parts of initiator, 0-2 parts of accelerator, and 1-5 parts of plasticizer.

[0052] In some embodiments of the present invention, the mass ratio of the component A to the component B is 100:2-6.

[0053] In some embodiments of the present invention, the initiator may be a peroxide initiator, and the peroxide initiator may be selected from methyl ethyl ketone peroxide, cumene hydroperoxide, dibenzoyl peroxide, etc. In some embodiments of the present invention, the accelerator may be an organic acid salt and / or an organic amine; further, for example, it may be cobalt naphthoate, N,N-dimethylaniline, etc.

[0054] In some embodiments of the present invention, the plasticizer may be dibutyl phthalate, dioctyl phthalate, trioctyl trimellitate or dioctyl terephthalate.

[0055] Another technical solution provided by the present invention is a method for preparing the above-mentioned casting resin, the preparation method comprising:

[0056] Component A: Add polyester imine resin, vinyl crosslinking agent and polymerization inhibitor into a stirring device, stir and mix at 25-35°C, and filter;

[0057] Component B: Add the peroxide initiator, accelerator and plasticizer into a stirring device, stir and mix at 25-35°C, and filter.

[0058] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0059] Based on the deficiencies of existing polyesterimide resins in performance such as strength, heat resistance and flame retardancy, the present invention innovatively introduces compounds represented by formula (I), compounds represented by formula (II) and compounds represented by formula (III) simultaneously during the polymerization process, so that the polyesterimide resin of the present invention can obtain high-content and uniformly distributed imine groups in the main chain, providing more and uniform cross-linking sites, which is conducive to miscibility with organic resins such as epoxy, alkyd, vinyl, etc., and more chemical bonds can be formed between the molecular chains of the polyesterimide resin, so that the filling amount of the formed polymer in the matrix is ​​greatly increased, and the overall performance of the material is enhanced. At the same time, the polyesterimide resin of the present invention has the advantage of controllable molecular chain length, improved fluidity and permeability, and practice shows that the polyesterimide resin of the present invention has relatively excellent mechanical properties, electrical properties, heat resistance and degradation resistance.

[0060] In addition, the polyester imide resin of the present invention does not need to add toxic and harmful diluents when used, which is beneficial to the green and environmental protection of product production and use processes, and can be widely used in the manufacture of glass fiber reinforced plastics, wind turbine blades, and electrical insulation materials. DETAILED DESCRIPTION

[0061] The above scheme is further described below in conjunction with specific embodiments; it should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions adopted in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0062] Unless otherwise specified in the following examples, all raw materials are commercially available or prepared by conventional methods in the art.

[0063] The iminodiacetic acid bis-β-(1,2-propylene glycol) used in the following examples was prepared as follows: diethyl iminodiacetate (1 mol), 1,2-propylene glycol (2 mol) and zinc acetate (0.34 g) were added to a 500 mL three-necked flask, the condensing reflux device was opened, the temperature was raised to 120° C., and after most of the solid components of the raw materials were dissolved, stirring was started, and then the temperature was slowly raised to 175° C. to start ester exchange, reflux reaction for 0.5 hours, and then ethanol was removed by distillation. The ethanol to be removed and collected reached more than 99% of the theoretical value, and the reaction temperature was continued to be heated and controlled at 195° C., cooled to 120° C., and the residual heat was used to filter out solid impurity particles with a Buchner funnel. The filtrate was stirred and gradually cooled to -5 to 0° C., and the crystalline product was filtered out for standby use.

[0064] Iminodiacetic acid bis-β-(neopentyl glycol) was prepared as follows: diethyl iminodiacetate (1 mol), neopentyl glycol (2 mol) and zinc acetate (0.4 g) were added to a 500 mL three-necked flask, the condensing reflux device was opened, the temperature was raised to 120° C., and after most of the raw material solid components were dissolved, stirring was started, and then the temperature was slowly raised to 175° C. to start ester exchange, reflux reaction was carried out for 0.5 hours, and then ethanol was removed by distillation, and the ethanol to be removed and collected reached more than 99% of the theoretical value, and the heating was continued and the reaction temperature was controlled at 195° C., and then cooled to 120° C., and the residual heat was used to filter out solid impurity particles with a Buchner funnel, and the filtrate was gradually cooled to -5 to 0° C. under stirring, and the crystallized product was filtered out for standby use.

[0065] Example 1

[0066] This example provides a polyester imine resin and a preparation method thereof. The raw materials of the polyester imine resin include: 281.21 g (1 mol) of iminodiacetic acid di-β-(1,2-propylene glycol), 39.22 g (0.4 mol) of maleic anhydride, 74.06 g (0.5 mol) of phthalic anhydride, 25.72 g (0.1 mol) of 4,4'-iminodibenzoic acid, 9.46 g (0.05 mol) of 4-maleimidophenol, 5.5 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0067] The preparation method of the polyesterimide resin comprises the following steps: adding raw materials other than hydroquinone into a four-necked flask with a temperature control and stirring device, passing a nitrogen atmosphere for protection, opening a condensation reflux device, heating to 120°C, starting stirring after most of the raw material solid components are dissolved, slowly heating to 165°C to start generating byproduct water, performing esterification reflux reaction for 0.5 hours, starting distillation and dehydration to perform esterification polycondensation, and starting vacuumization to perform reduced pressure distillation to continue polycondensation reaction after the acid value reaches 35 mgKOH / g, reacting until the acid value decreases to 10 mgKOH / g, cooling to 130°C, adding hydroquinone, stirring for 10 minutes, and continuing to cool to below 80°C to filter and discharge the material to obtain the polyesterimide resin.

[0068] In this example, the time for esterification and polycondensation when the acid value reaches 35 mgKOH / g is about 5 hours.

[0069] The average molecular weight of the product was measured by GPC (gel permeation chromatography) and was approximately 1987. The nitrogen content was measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product was approximately 0.262. The crystallinity of the product was measured according to ASTM F2625-2010 and was approximately 67.5%.

[0070] Example 2

[0071] This example provides a polyester imine resin and a preparation method thereof. The raw materials of the polyester imine resin include: 337.21 g (1 mol) of iminodiacetic acid bis-β-(neopentyl glycol), 46.41 g (0.4 mol) of fumaric acid, 74.06 g (0.5 mol) of phthalic anhydride, 25.72 g (0.1 mol) of 4,4'-iminodibenzoic acid, 9.46 g (0.05 mol) of 4-maleimidophenol, 5.5 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0072] The preparation method is the same as that of Example 1.

[0073] The average molecular weight of the product measured by GPC (gel permeation chromatography) is about 2037, the nitrogen content is measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product is about 0.231, and the crystallinity of the product is measured according to ASTM F2625-2010 and is about 67.1%.

[0074] Example 3

[0075] This example provides a polyester imine resin and a preparation method thereof. The raw materials of the polyester imine resin include: 281.21 g (1 mol) of iminodiacetic acid di-β-(1,2-propylene glycol), 39.22 g (0.4 mol) of maleic anhydride, 83.09 g (0.5 mol) of methyltetrahydrophthalic anhydride, 25.72 g (0.1 mol) of 4,4'-iminodibenzoic acid, 9.46 g (0.05 mol) of 4-maleimidophenol, 5.5 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0076] The preparation method is the same as Example 1.

[0077] The average molecular weight of the product measured by GPC (gel permeation chromatography) is about 2000, the nitrogen content is measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product is about 0.264, and the crystallinity of the product is measured according to ASTM F2625-2010 and is about 67.3%.

[0078] Example 4

[0079] This example provides a polyester imine resin and a preparation method thereof. The raw materials of the polyester imine resin include: 337.21 g (1 mol) of iminodiacetic acid bis-β-(neopentyl glycol), 46.41 g (0.4 mol) of fumaric acid, 83.09 g (0.5 mol) of methyltetrahydrophthalic anhydride, 25.72 g (0.1 mol) of 4,4'-iminodibenzoic acid, 9.46 g (0.05 mol) of 4-maleimidophenol, 5.5 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0080] The preparation method is the same as Example 1.

[0081] The average molecular weight of the product measured by GPC (gel permeation chromatography) is about 2048, the nitrogen content is measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product is about 0.233, and the crystallinity of the product is measured according to ASTM F2625-2010 and is about 67%.

[0082] Comparative Example 1

[0083] This example provides a polyesterimide resin and a preparation method thereof. The raw materials of the polyesterimide resin include: 76.09 g (1 mol) of 1,2-propylene glycol, 104.15 g (1 mol) of neopentyl glycol, 78.44 g (0.8 mol) of maleic anhydride, 177.74 g (1.2 mol) of phthalic anhydride, 19.12 g (0.1 mol) of N-hydroxyethylphthalimide, 11 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0084] The preparation method is the same as Example 1.

[0085] In this example, the time for esterification and polycondensation when the acid value reaches 35 mgKOH / g is about 13 hours.

[0086] The average molecular weight of the product was measured by GPC (gel permeation chromatography) and was approximately 1574. The nitrogen content was measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product was approximately 0.021. The crystallinity of the product was measured according to ASTM F2625-2010 and was approximately 5.6%.

[0087] Comparative Example 2

[0088] This example provides a polyester imine resin and a preparation method thereof. The raw materials of the polyester imine resin include: 76.09 g (1 mol) of 1,2-propylene glycol, 104.15 g (1 mol) of neopentyl glycol, 92.82 g (0.8 mol) of fumaric acid, 199.42 g (1.2 mol) of methyltetrahydrophthalic anhydride, 19.12 g (0.1 mol) of N-hydroxyethyl phthalimide, 11 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0089] The preparation method is the same as that of Example 1.

[0090] The average molecular weight of the product measured by GPC (gel permeation chromatography) is about 1580, the nitrogen content is measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product is about 0.020, and the crystallinity of the product is measured according to ASTM F2625-2010 and is about 6.1%.

[0091] Comparative Example 3

[0092] This example provides a polyester imine resin and a preparation method thereof. The raw materials of the polyester imine resin include: 208.3 g (2 mol) of neopentyl glycol, 133.1 g (1 mol) of iminodiacetic acid, 39.22 g (0.4 mol) of maleic anhydride, 83.09 g (0.5 mol) of methyltetrahydrophthalic anhydride, 25.72 g (0.1 mol) of 4,4'-iminodibenzoic acid, 9.46 g (0.05 mol) of 4-maleimidophenol, 5.5 g of p-toluenesulfonic acid, and 0.5 g of hydroquinone.

[0093] The preparation method is the same as that of Example 1.

[0094] The average molecular weight of the product was measured by GPC (gel permeation chromatography) and was approximately 1915. The nitrogen content was measured according to GB / T 609-2018 and the imine value (mol / 100g) of the product was approximately 0.193. The crystallinity of the product was measured according to ASTM F2625-2010 and was approximately 51.7%.

[0095] Application Example 1

[0096] This example provides a casting resin, which includes a component A and a component B;

[0097] In parts by weight, in component A, 100 parts of the polyesterimide resin prepared in Example 1, 35 parts of vinyltoluene and 0.14 parts of p-hydroxyanisole;

[0098] In terms of weight, in component B, 1.35 parts of methyl ethyl ketone peroxide, 0.65 parts of cumene hydroperoxide, 0.65 parts of cobalt naphthoate, and 2.7 parts of dioctyl terephthalate;

[0099] The feed mass ratio of component A to component B is 135.14:5.35;

[0100] The method for preparing the casting resin comprises:

[0101] Component A: Add all components into a stirring device, stir and mix at 30°C and 1000 rpm for 60 min, and filter to obtain component A;

[0102] Component B: Add all components into a stirring device, stir and mix at 30°C and 1000 rpm for 60 minutes, and filter to obtain component B.

[0103] In actual application, component A and component B are mixed.

[0104] Application Example 2

[0105] This example provides a casting resin, which is basically the same as Application Example 1, except that the polyesterimide resin prepared in Example 1 is replaced with an equal amount of the polyesterimide resin prepared in Example 2.

[0106] Application Example 3

[0107] This example provides a casting resin, which includes a component A and a component B;

[0108] In parts by weight, in component A, 100 parts of the polyesterimide resin prepared in Example 3, 35 parts of vinyltoluene and 0.14 parts of p-hydroxyanisole;

[0109] In terms of weight, in component B, 0.65 parts of cumene hydroperoxide, 1.35 parts of dibenzoyl peroxide, and 2.7 parts of dioctyl terephthalate;

[0110] The feed mass ratio of component A to component B is 135.14:4.7;

[0111] The rest is the same as Application Example 1.

[0112] Application Example 4

[0113] This example provides a casting resin, which is basically the same as Application Example 3, except that the polyesterimide resin prepared in Example 3 is replaced with the polyesterimide resin prepared in Example 4 in the same amount.

[0114] Application Comparative Example 1

[0115] This example provides a casting resin, which is basically the same as Application Example 4, except that the polyesterimide resin prepared in Example 1 is replaced with the polyesterimide resin prepared in Comparative Example 1 with the same addition amount.

[0116] Application Comparative Example 2

[0117] This example provides a casting resin, which is basically the same as Application Example 4, except that the polyesterimide resin prepared in Example 1 is replaced with the polyesterimide resin prepared in Comparative Example 2 with the same addition amount.

[0118] Application Comparative Example 3

[0119] This example provides a casting resin, which is basically the same as Application Example 4, except that the polyesterimide resin prepared in Example 1 is replaced with the polyesterimide resin prepared in Comparative Example 3 with the same addition amount.

[0120] Performance Testing

[0121] The casting resins obtained in the above application examples 1-4 and comparative application examples 1-3 were subjected to the following performance tests, and the specific results are shown in Table 1. The test standards for tensile strength, elongation, and flexural strength are: GB / T 2567-2021; the test standard for heat deformation temperature is: GB / T 1634.1-2019; the test standard for electrical strength is: GB / T 15022.2-2017; and the test standard for flame retardancy is: UL 94.

[0122] Table 1

[0123]

[0124] In summary, the preparation process of the polyester imine resin of the present invention significantly shortens the polymerization reaction time, and the obtained unsaturated polyester imine has a high imine content and a uniformly distributed imino structure. Furthermore, the prepared casting resin exhibits high activity, rapid curing, and significantly improved heat resistance, mechanical properties and electrical insulation properties (more than 20% improvement compared to ordinary polyester imine resins). Thanks to the high imine content, the product also has certain flame retardant properties and is expected to show a wide range of application potential in multiple fields. In the field of polymer materials, it can be used to manufacture high-performance heat-resistant and chemically resistant polymers, and is particularly suitable for high-end manufacturing industries such as aerospace, large wind power, electronic appliances, and automobile manufacturing. In the biomedical field, the polyester imine resin may exhibit specific biological activity or biocompatibility, and is expected to be used in the preparation of biomedical materials, such as drug carriers, tissue engineering scaffolds, etc. In addition, due to its unique chemical properties, the polyester imine resin also has potential application prospects in other fields such as energy and environmental protection.

[0125] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0126] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A polyester imide resin, characterized in that The raw materials of the polyester imide resin include: (a) Compound represented by formula (I) In formula (I), R1 and R2 are independently C 1-8 Alkylene; (b) unsaturated dibasic acids; (c) saturated dibasic acid anhydrides; (d) Compound represented by formula (II) In formula (II), R3 and R4 are independently selected from substituted C 6-12 The aromatic ring, the substituents used for substitution include carboxyl, and selected from H, C 1-6 Alkyl and C 1-6 one or more of the alkoxy groups; (e) Compound represented by formula (III) In formula (III), one of R5 and R6 is a hydroxyl group, and the other is selected from H, C 1-6 Alkyl or C 1-6 Alkoxy.

2. The polyesterimide resin according to claim 1, characterized in that The molar ratio of the compound represented by formula (I), the unsaturated dibasic acid, the saturated dibasic acid anhydride, the compound represented by formula (II) and the compound represented by formula (III) is 1:0.3-0.5:0.4-0.6:0.05-0.15:0.05-0.

25.

3. The polyesterimide resin according to claim 1, characterized in that The preparation method of the compound represented by formula (I) comprises: reacting diethyl iminodiacetate with C 1-8 Alkylene glycol is prepared by transesterification reaction, wherein the C 1-8 The alkylene glycol is selected from the following structures:

4. The polyesterimide resin according to claim 1, characterized in that R1, R2 are independently selected from 5. The polyesterimide resin according to claim 1, characterized in that The unsaturated dibasic acid is maleic anhydride and / or fumaric acid; and / or the saturated dibasic acid anhydride is phthalic anhydride and / or methyltetrahydrophthalic anhydride.

6. The polyesterimide resin according to claim 1, characterized in that In formula (II), R3 and R4 are independently selected from R7 is selected from H, methyl, ethyl, propyl or methoxy; and / or, in formula (III), R5 is a hydroxyl group substituted at the para position, and R6 is selected from H, methyl, ethyl, propyl or methoxy.

7. The polyesterimide resin according to claim 1, characterized in that The raw material of the polyesterimide resin further comprises (f) an esterification catalyst and (g) a polymerization inhibitor; Furthermore, the molar ratio of the esterification catalyst to the compound represented by formula (I) is 0.02-0.08:1; Furthermore, the addition amount of the polymerization inhibitor is 0.05%-0.5% of the total mass of the raw material of the polyesterimide resin; Further, the esterification catalyst is a combination of one or more selected from sulfuric acid, p-toluenesulfonic acid, and ion exchange resin; Furthermore, the polymerization inhibitor is a combination of one or more selected from hydroquinone, nitrobenzene, tert-butylcatechol, and p-hydroxyanisole.

8. A method for preparing the polyesterimide resin according to any one of claims 1 to 7, characterized in that: The preparation method comprises: mixing other components of the raw materials of the polyester imine resin except the polymerization inhibitor, heating under a protective atmosphere, reacting, and selectively removing generated water at each stage of the reaction; when the acid value reaches 30-40 mgKOH / g, performing vacuum reduced pressure distillation and continuing the reaction; when the acid value decreases to 5-15 mgKOH / g, cooling, adding the polymerization inhibitor, and mixing.

9. Use of the polyesterimide resin according to any one of claims 1 to 7 in the preparation of casting resin.

10. The use according to claim 9, characterized in that: The casting resin comprises component A and component B; The component A comprises the polyester imine resin according to any one of claims 1 to 7, a vinyl crosslinking agent and an optionally included polymerization inhibitor; The second component comprises an initiator, a plasticizer and an optionally contained accelerator.

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