Method for producing amide-modified unsaturated polyester resin, insulating paint and application thereof

Abstract

The application provides a preparation method of an amide-modified unsaturated polyester resin, comprising the following steps: reacting at least one of a binary acyl chloride and a binary acid with a monovalent amine containing a hydroxyl group, and / or reacting a binary amine with a monovalent acid containing a hydroxyl group to obtain an amide alcohol; and reacting at least one of an unsaturated binary acid and an unsaturated binary anhydride, at least one of a saturated binary acid and a saturated binary anhydride, a binary alcohol, an end-capping agent and the amide alcohol to obtain the amide-modified unsaturated polyester resin. The amide-modified unsaturated polyester resin can improve the bonding strength, tensile strength, bending strength and wear resistance of an insulating paint, and is beneficial to the use of the insulating paint. The application further provides the insulating paint and an application thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulating paint, in particular to a preparation method of amide-modified unsaturated polyester resin, insulating paint and application thereof. BACKGROUND

[0002] The insulating paint can fill all space gaps of the stator winding and coil in the motor, so that the stator winding and coil become a whole, and the electrical insulation, mechanical strength and chemical corrosion resistance of the stator winding and coil are improved. However, the bonding strength of the existing insulating paint is not enough, and the mechanical strength and wear resistance need to be improved. SUMMARY

[0003] Therefore, the present application provides a preparation method of amide-modified unsaturated polyester resin, insulating paint and application thereof. The amide-modified unsaturated polyester resin can improve the bonding strength, tensile strength, bending strength and wear resistance of the insulating paint, which is beneficial to the use of the insulating paint.

[0004] In a first aspect, the present application provides a preparation method of amide-modified unsaturated polyester resin, comprising:

[0005] At least one of a binary acid chloride and a binary acid reacts with a monovalent amine containing a hydroxyl group, and / or a binary amine reacts with a monovalent acid containing a hydroxyl group to obtain an amide alcohol;

[0006] At least one of an unsaturated binary acid and an unsaturated binary anhydride, at least one of a saturated binary acid and a saturated binary anhydride, a binary alcohol, an end-capping agent and the amide alcohol are reacted to obtain an amide-modified unsaturated polyester resin.

[0007] Optionally, the amide alcohol is of an asymmetric structure.

[0008] Optionally, the molar ratio of the at least one of the binary acid chloride and the binary acid to the monovalent amine containing a hydroxyl group is 1:(2-2.5).

[0009] Further, the molar ratio of the at least one of the binary acid chloride and the binary acid to the monovalent amine containing a hydroxyl group is 1:(2-2.2).

[0010] Optionally, the molar ratio of the binary amine to the monovalent acid containing a hydroxyl group is 1:(2-2.5).

[0011] Further, the molar ratio of the binary amine to the monovalent acid containing a hydroxyl group is 1:(2-2.2).

[0012] Optionally, the mass ratio of the at least one of the unsaturated dibasic acid and the unsaturated dibasic anhydride, the at least one of the saturated dibasic acid and the saturated dibasic anhydride, the dihydric alcohol, the end-capping agent, and the amide alcohol is (11-22):(6-15):(13-25):(5-15):(2-10).

[0013] Further, the mass ratio of the at least one of the unsaturated dibasic acid and the unsaturated dibasic anhydride, the at least one of the saturated dibasic acid and the saturated dibasic anhydride, the dihydric alcohol, the end-capping agent, and the amide alcohol is (13-20):(7-14):(15-21):(7-12):(3-8).

[0014] Optionally, the dibasic acid chloride comprises at least one of terephthaloyl chloride, isophthaloyl chloride, adipoyl chloride, and succinyl chloride.

[0015] Optionally, the dibasic acid comprises at least one of terephthalic acid, isophthalic acid, and adipic acid.

[0016] Optionally, the hydroxyl-containing monohydric amine comprises at least one of isopropanolamine, 3-amino-1-propanol, and monoethanolamine.

[0017] Optionally, the dibasic amine comprises at least one of isophorone diamine, p-phenylenediamine, m-phenylenediamine, 4,4-diaminodiphenylmethane, and 4,4-diaminodiphenyl ether.

[0018] Optionally, the hydroxyl-containing monohydric acid comprises at least one of 3-hydroxypropionic acid, 2-hydroxypropionic acid, hydroxybenzoic acid, hydroxyphenylacetic acid, and hydroxyphenoxyacetic acid.

[0019] Optionally, the unsaturated dibasic acid comprises at least one of maleic acid and fumaric acid.

[0020] Optionally, the unsaturated dibasic anhydride comprises at least one of maleic anhydride and fumaric anhydride.

[0021] Optionally, the saturated dibasic acid comprises at least one of terephthalic acid, isophthalic acid, adipic acid, and succinic acid.

[0022] Optionally, the saturated dibasic anhydride comprises phthalic anhydride.

[0023] Optionally, the dihydric alcohol comprises at least one of ethylene glycol, 1,3-propanediol, 1,2-propanediol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and bisphenol A.

[0024] Optionally, the end-capping agent comprises at least one of benzyl alcohol, phenol, p-cresol, and cyclohexylmethanol.

[0025] The preparation method provided by the application is simple, convenient to operate, and can prepare an amide-modified unsaturated polyester resin, which is modified by an amide group, improves the mechanical strength and wear resistance of the resin, and can form a bond with other structures to improve the bonding performance.

[0026] In a second aspect, the application provides an insulating paint comprising the amide-modified unsaturated polyester resin of the first aspect.

[0027] Optionally, the insulating paint comprises 45-75 parts by weight of the amide-modified unsaturated polyester resin, 25-55 parts by weight of the reactive diluent, 2-5 parts by weight of the initiator, and 0.02-0.06 parts by weight of the polymerization inhibitor.

[0028] Optionally, the boiling point of the reactive diluent is greater than 200℃.

[0029] Optionally, the reactive diluent comprises at least one of diallyl phthalate, diallyl isophthalate, divinyl toluene, triethylene glycol dimethacrylate, 1,6-hexanediol diacrylate, and lauryl methacrylate.

[0030] Optionally, the initiator comprises at least one of dicumyl peroxide, benzoyl peroxide, and tert-butyl peroxybenzoate.

[0031] Optionally, the polymerization inhibitor comprises at least one of tert-butyl pyrocatechol, hydroquinone, and p-benzoquinone.

[0032] The insulating paint provided by the application has the amide-modified unsaturated polyester resin, so that the bonding strength, tensile strength, bending strength, and wear resistance of the insulating paint are improved, which is beneficial to the use of the insulating paint.

[0033] In a third aspect, the application provides the use of the insulating paint of the second aspect in a motor.

[0034] The insulating paint provided by the application has excellent bonding strength, tensile strength, bending strength, and wear resistance, which can ensure the insulation performance of the insulating paint part in the motor and the overall bonding force, and is also beneficial to improving the wear resistance of the motor during use. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. The specific embodiments described herein are only used to explain the application and not to limit the application.

[0036] Figure 1This is a flow chart of a method for preparing an amide-modified unsaturated polyester resin provided in one embodiment of the present application. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] See also Figure 1 , is a flow chart of a method for preparing an amide-modified unsaturated polyester resin provided in one embodiment of the present application, comprising:

[0039] S101: reacting at least one of a dibasic acid chloride and a dibasic acid with a hydroxyl-containing monoamine, and / or reacting a diamine with a hydroxyl-containing monoacid to obtain an amide alcohol.

[0040] S102: reacting at least one of an unsaturated dibasic acid and an unsaturated dibasic acid anhydride, at least one of a saturated dibasic acid and a saturated dibasic acid anhydride, a diol, a capping agent, and an amide alcohol to obtain an amide-modified unsaturated polyester resin.

[0041] This application modifies the unsaturated polyester resin and introduces an amide bond into the unsaturated polyester main chain, which is beneficial to improving the bonding with other structures and increasing the bonding strength. At the same time, the amide structure also improves the mechanical strength and wear resistance of the resin, which is beneficial for its use in insulating paint.

[0042] In S101, at least one of a dibasic acid chloride and a dibasic acid reacts with a hydroxyl-containing monoamine to form an amido-alcohol. Specifically, a dibasic acid chloride can react with a hydroxyl-containing monoamine to form an amido-alcohol, a dibasic acid can react with a hydroxyl-containing monoamine to form an amido-alcohol, and a mixture of a dibasic acid chloride and a dibasic acid reacts with a hydroxyl-containing monoamine to form an amido-alcohol. Of course, an amido-alcohol can also be formed by reacting a dibasic acid with a hydroxyl-containing monoamine.

[0043] In the present application, the dibasic acid chloride contains two acyl chloride groups. In one embodiment of the present application, the dibasic acid chloride is a small molecule compound. In one embodiment, the dibasic acid chloride has less than or equal to 15 carbon atoms. In another embodiment, the dibasic acid chloride has less than or equal to 10 carbon atoms. In yet another embodiment, the dibasic acid chloride has less than or equal to 8 carbon atoms. In one embodiment of the present application, the dibasic acid chloride includes at least one of terephthaloyl chloride, isophthaloyl chloride, adipoyl chloride, and succinoyl chloride.

[0044] In one embodiment of the present application, the structural formula of the dibasic acid chloride can be R1may be, but is not limited to, an aliphatic group, an alicyclic group or an aromatic group.

[0045] In the present application, the monohydroxyl-containing monamine has a hydroxyl group and one amine group. In an embodiment of the present application, the monohydroxyl-containing monamine is a small molecule compound. In an embodiment, the monohydroxyl-containing monamine has a carbon atom number less than or equal to 15. In another embodiment, the monohydroxyl-containing monamine has a carbon atom number less than or equal to 10. In yet another embodiment, the monohydroxyl-containing monamine has a carbon atom number less than or equal to 8. In yet another embodiment, the monohydroxyl-containing monamine has a carbon atom number less than or equal to 5. In an embodiment of the present application, the monohydroxyl-containing monamine has one hydroxyl group. In an embodiment of the present application, the monohydroxyl-containing monamine includes at least one of isopropanolamine, 3-amino-1-propanol and monoethanolamine.

[0046] In an embodiment of the present application, the monohydroxyl-containing monamine can have a structure of HO-R2-NH2. R2may be, but is not limited to, an aliphatic group, an alicyclic group or an aromatic group.

[0047] In an embodiment of the present application, the acyl chloride reacts with the monohydroxyl-containing monamine to generate an amido alcohol. In an embodiment of the present application, the molar ratio of the acyl chloride to the monohydroxyl-containing monamine is 1:(2-2.5). This is conducive to ensuring that the acyl chloride and the monohydroxyl-containing monamine are fully reacted. Specifically, the molar ratio of the acyl chloride to the monohydroxyl-containing monamine can be, but is not limited to, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4 or 1:2.5, etc. In another embodiment of the present application, the molar ratio of the acyl chloride to the monohydroxyl-containing monamine is 1:(2-2.2). In yet another embodiment of the present application, the molar ratio of the acyl chloride to the monohydroxyl-containing monamine is 1:2. This is conducive to ensuring that the acyl chloride and the monohydroxyl-containing monamine are fully reacted.

[0048] In an embodiment of the present application, the acyl chloride and the monohydroxyl-containing monamine can be reacted at 0-5°C (such as 0°C, 1°C, 2°C, 3°C, 4°C or 5°C, etc.) for 1-2h (such as 1h, 1.5h, 1.8h or 2h), and then reacted at 20-30°C (such as 20°C, 22°C, 25°C, 27°C, 29°C or 30°C, etc.) for 2-5h (such as 2h, 3h, 4h or 5h). The acyl chloride has strong reactivity, and the preliminary reaction is performed at low temperature to prevent the reaction from being too violent due to high temperature, and the reaction is continued at room temperature after a period of time to improve the safety of the reaction process and ensure that the reaction is fully performed. In an embodiment of the present application, the acyl chloride and the monohydroxyl-containing monamine can be reacted at 0°C for 2h, and then reacted at 25°C for 3h.

[0049] In the present application, a dibasic acid contains two carboxylic acid groups. In an embodiment of the present application, the dibasic acid is a small molecule compound. In an embodiment, the number of carbon atoms in the dibasic acid is less than or equal to 15. In another embodiment, the number of carbon atoms in the dibasic acid is less than or equal to 10. In yet another embodiment, the number of carbon atoms in the dibasic acid is less than or equal to 8. In an embodiment of the present application, the dibasic acid comprises at least one of terephthalic acid, isophthalic acid, and adipic acid.

[0050] In an embodiment of the present application, the dibasic acid can have a structure of wherein R1may be, but is not limited to, an aliphatic group, an alicyclic group, or an aromatic group.

[0051] In an embodiment of the present application, the dibasic acid is reacted with a monohydric amine containing hydroxyl group to form an amido alcohol. In the above reaction, the amine group in the monohydric amine containing hydroxyl group replaces the hydroxyl groups of the two carboxylic acid groups in the dibasic acid to form the amido alcohol. In an embodiment of the present application, the molar ratio of the dibasic acid to the monohydric amine containing hydroxyl group is 1:(2-2.5). This is advantageous to ensure that the dibasic acid and the monohydric amine containing hydroxyl group are fully reacted. Specifically, the molar ratio of the dibasic acid to the monohydric amine containing hydroxyl group can be, but is not limited to, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, or 1:2.5, etc. In another embodiment of the present application, the molar ratio of the dibasic acid to the monohydric amine containing hydroxyl group is 1:(2-2.2). In yet another embodiment of the present application, the molar ratio of the dibasic acid to the monohydric amine containing hydroxyl group is 1:2. This is advantageous to ensure that the dibasic acid and the monohydric amine containing hydroxyl group are fully reacted.

[0052] In an embodiment of the present application, the dibasic acid and the monohydric amine containing hydroxyl group can be reacted at 150-160°C (e.g., 150°C, 152°C, 154°C, 155°C, 157°C, 158°C, or 160°C, etc.) for 1-2h (e.g., 1h, 1.5h, 1.8h, or 2h), and then reacted at 210-220°C (e.g., 210°C, 213°C, 215°C, 217°C, 219°C, or 220°C, etc.) for 2-5h (e.g., 2h, 3h, 4h, or 5h). By gradually increasing the reaction temperature, the reaction is more complete. In an embodiment of the present application, the dibasic acid and the monohydric amine containing hydroxyl group can be reacted at 150°C for 2h, and then reacted at 210°C for 3h. In another embodiment of the present application, the dibasic acid and the monohydric amine containing hydroxyl group can be reacted at 160°C for 1h, and then reacted at 220°C for 1h. In yet another embodiment of the present application, the dibasic acid and the monohydric amine containing hydroxyl group can be reacted at 155°C for 1.5h, and then reacted at 215°C for 4h.

[0053] In one embodiment of the present application, the molar ratio of at least one of the dibasic acid chloride and the dibasic acid to the hydroxyl-containing monoamine is 1:(2-2.5). That is, the molar ratio of the dibasic acid chloride to the hydroxyl-containing monoamine is 1:(2-2.5), or the molar ratio of the dibasic acid to the hydroxyl-containing monoamine is 1:(2-2.5), or the ratio of the molar amount of the dibasic acid chloride and the dibasic acid to the molar amount of the hydroxyl-containing monoamine is 1:(2-2.5). In another embodiment of the present application, the molar ratio of at least one of the dibasic acid chloride and the dibasic acid to the hydroxyl-containing monoamine is 1:(2-2.2). In yet another embodiment of the present application, the molar ratio of at least one of the dibasic acid chloride and the dibasic acid to the hydroxyl-containing monoamine is 1:2.

[0054] In the present application, the diamine contains two amine groups. In one embodiment of the present application, the diamine is a small molecule compound. In one embodiment, the diamine has 15 or fewer carbon atoms. In another embodiment, the diamine has 13 or fewer carbon atoms. In yet another embodiment, the diamine has 10 or fewer carbon atoms. In one embodiment of the present application, the diamine includes at least one of isophorone diamine, p-phenylenediamine, m-phenylenediamine, 4,4-diaminodiphenylmethane, and 4,4-diaminodiphenyl ether.

[0055] In one embodiment of the present application, the structural formula of the diamine may be NH2-R2-NH2, wherein R2 may be, but is not limited to, an aliphatic group, an alicyclic group, or an aromatic group.

[0056] In the present application, the hydroxyl-containing monoacid has a hydroxyl group and a carboxyl group. In one embodiment of the present application, the hydroxyl-containing monoacid is a small molecule compound. In one embodiment, the number of carbon atoms in the hydroxyl-containing monoacid is less than or equal to 15. In another embodiment, the number of carbon atoms in the hydroxyl-containing monoacid is less than or equal to 12. In yet another embodiment, the number of carbon atoms in the hydroxyl-containing monoacid is less than or equal to 10. In one embodiment of the present application, the hydroxyl-containing monoacid has one hydroxyl group. In one embodiment of the present application, the hydroxyl-containing monoacid includes at least one of 3-hydroxypropionic acid, 2-hydroxypropionic acid, hydroxybenzoic acid, hydroxyphenylacetic acid, and hydroxyphenoxyacetic acid.

[0057] In one embodiment of the present application, the structural formula of the monobasic acid containing hydroxyl group can be Wherein, R1 can be, but is not limited to, an aliphatic group, an alicyclic group or an aromatic group.

[0058] In an embodiment of the present application, the diamine reacts with the monohydroxy-containing monobasic acid to form an amido alcohol. In the above reaction, the amine group in the diamine replaces the hydroxyl group of the carboxylic acid group in the monohydroxy-containing monobasic acid to form the amido alcohol. In an embodiment of the present application, the molar ratio of the diamine to the monohydroxy-containing monobasic acid is 1:(2-2.5). This is advantageous to ensure that the diamine and the monohydroxy-containing monobasic acid are fully reacted. Specifically, the molar ratio of the diamine to the monohydroxy-containing monobasic acid can be, but is not limited to, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, or 1:2.5, etc. In another embodiment of the present application, the molar ratio of the diamine to the monohydroxy-containing monobasic acid is 1:(2-2.2). In yet another embodiment of the present application, the molar ratio of the diamine to the monohydroxy-containing monobasic acid is 1:2. This is advantageous to ensure that the diamine and the monohydroxy-containing monobasic acid are fully reacted.

[0059] In an embodiment of the present application, the diamine and the monohydroxy-containing monobasic acid can be reacted at 150-160°C (such as 150°C, 152°C, 154°C, 155°C, 157°C, 158°C, or 160°C, etc.) for 1-2h (such as 1h, 1.5h, 1.8h, or 2h), and then reacted at 210-220°C (such as 210°C, 213°C, 215°C, 217°C, 219°C, or 220°C, etc.) for 2-5h (such as 2h, 3h, 4h, or 5h). By gradually increasing the reaction temperature, the reaction is more complete. In an embodiment of the present application, the diamine and the monohydroxy-containing monobasic acid can be reacted at 150°C for 2h, and then reacted at 210°C for 3h. In another embodiment of the present application, the diamine and the monohydroxy-containing monobasic acid can be reacted at 160°C for 1h, and then reacted at 220°C for 1h. In yet another embodiment of the present application, the diamine and the monohydroxy-containing monobasic acid can be reacted at 155°C for 1.5h, and then reacted at 215°C for 4h.

[0060] In an embodiment of the present application, the reaction process of the diamine chloride and the monohydroxy-containing monobasic amine to form the amido alcohol is as follows:

[0061]

[0062] In an embodiment of the present application, the reaction process of the diamine chloride and the monohydroxy-containing monobasic amine to form the amido alcohol is as follows:

[0063]

[0064] In an embodiment of the present application, the reaction process of the diamine chloride and the monohydroxy-containing monobasic amine to form the amido alcohol is as follows:

[0065]

[0066] In an embodiment of the present application, the structural formula of the amido alcohol can be In another embodiment of the present application, the amidoalcohol can have a structural formula of

[0067] In an embodiment of the present application, the reaction for generating the amidoalcohol can be carried out in a solvent. The solvent can dissolve the reactants for generating the amidoalcohol and is not reactive with the reactants. Specifically, the solvent can include at least one of N,N-dimethylformamide, N-methylpyrrolidone, but is not limited thereto. In an embodiment, the reactants for generating the amidoalcohol can be mixed with the solvent, and then another reactant can be added to the mixture for reaction. In another embodiment, the reactants for generating the amidoalcohol can be mixed with the solvent, and then a solution containing another reactant can be added to the mixture for reaction. In an embodiment of the present application, the amidoalcohol can be obtained by sedimentation in ethyl acetate after the above reaction.

[0068] In an embodiment of the present application, the amidoalcohol has an asymmetric structure. This is advantageous for reducing the crystallinity of the main chain of the amide-modified unsaturated polyester resin and improving the compatibility of the amide-modified unsaturated polyester resin with the reactive diluent. It can be understood that the asymmetric structure is not a symmetric structure of the chemical structural formula of the amidoalcohol.

[0069] In an embodiment of the present application, the amidoalcohol is a small molecule compound. In an embodiment, the number of carbon atoms in the amidoalcohol is less than or equal to 40. In another embodiment, the number of carbon atoms in the amidoalcohol is less than or equal to 30. In yet another embodiment, the number of carbon atoms in the amidoalcohol is less than or equal to 20.

[0070] The present application prepares the amidoalcohol by using specific reactants, which are bifunctional, ensuring the performance of the amidoalcohol and avoiding the problem of excessive crosslinking of the subsequently prepared amide-modified unsaturated polyester resin, which affects the performance improvement. Therefore, the present application uses at least one of a binary acyl chloride and a binary acid to react with a monovalent amine containing a hydroxyl group, and / or a binary amine to react with a monovalent acid containing a hydroxyl group to obtain an amidoalcohol with excellent performance, which is advantageous for the subsequent preparation of the amide-modified unsaturated polyester resin.

[0071] In S102, at least one of the unsaturated dibasic acid and the unsaturated dibasic anhydride, at least one of the saturated dibasic acid and the saturated dibasic anhydride, the dihydric alcohol, the end-capping agent, and the amidoalcohol are subjected to condensation polymerization to obtain the amide-modified unsaturated polyester resin. That is, the reactants for preparing the amide-modified unsaturated polyester resin can select the unsaturated dibasic acid, or select the unsaturated dibasic anhydride, or select a mixture of the unsaturated dibasic acid and the unsaturated dibasic anhydride; the reactants for preparing the amide-modified unsaturated polyester resin can select the saturated dibasic acid, or select the saturated dibasic anhydride, or select a mixture of the saturated dibasic acid and the saturated dibasic anhydride.

[0072] In an embodiment of the application, the unsaturated diacid is a small molecule compound. In an embodiment, the unsaturated diacid has less than or equal to 15 carbon atoms. In another embodiment, the unsaturated diacid has less than or equal to 10 carbon atoms. In yet another embodiment, the unsaturated diacid has less than or equal to 7 carbon atoms. In an embodiment of the application, the unsaturated diacid includes at least one of maleic acid and fumaric acid.

[0073] In an embodiment of the application, the unsaturated diacid anhydride is a small molecule compound. In an embodiment, the unsaturated diacid anhydride has less than or equal to 15 carbon atoms. In another embodiment, the unsaturated diacid anhydride has less than or equal to 10 carbon atoms. In yet another embodiment, the unsaturated diacid anhydride has less than or equal to 7 carbon atoms. In an embodiment of the application, the unsaturated diacid anhydride includes at least one of maleic anhydride and fumaric anhydride.

[0074] In an embodiment of the application, the saturated diacid is a small molecule compound. In an embodiment, the saturated diacid has less than or equal to 15 carbon atoms. In another embodiment, the saturated diacid has less than or equal to 10 carbon atoms. In yet another embodiment, the saturated diacid has less than or equal to 8 carbon atoms. In an embodiment of the application, the saturated diacid includes at least one of terephthalic acid, isophthalic acid, adipic acid, and succinic acid.

[0075] In an embodiment of the application, the saturated diacid anhydride is a small molecule compound. In an embodiment, the saturated diacid anhydride has less than or equal to 15 carbon atoms. In another embodiment, the saturated diacid anhydride has less than or equal to 10 carbon atoms. In yet another embodiment, the saturated diacid anhydride has less than or equal to 8 carbon atoms. In an embodiment of the application, the saturated diacid anhydride includes phthalic anhydride.

[0076] In an embodiment of the application, the diol is a small molecule compound. In an embodiment, the diol has less than or equal to 15 carbon atoms. In another embodiment, the diol has less than or equal to 10 carbon atoms. In yet another embodiment, the diol has less than or equal to 8 carbon atoms. In an embodiment of the application, the diol includes at least one of ethylene glycol, 1,3-propanediol, 1,2-propanediol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and bisphenol A.

[0077] In an embodiment of the present application, at least one of the unsaturated dibasic acid, the unsaturated dibasic anhydride, the saturated dibasic acid, and the saturated dibasic anhydride is of an asymmetric structure. It can be understood that the asymmetric structure is a chemical structure formula of at least one of the unsaturated dibasic acid, the unsaturated dibasic anhydride, the saturated dibasic acid, and the saturated dibasic anhydride is not symmetric. By using the reactant of the asymmetric structure, it is beneficial to reduce the crystallinity of the amide-modified unsaturated polyester resin main chain and to improve the compatibility of the amide-modified unsaturated polyester resin with the reactive diluent.

[0078] In an embodiment of the present application, the structure formula of the saturated dibasic acid can be HOOC-R3-COOH or HOOC-R4-COOH. Wherein, R3, R4 are independently selected from a saturated aliphatic group or a saturated alicyclic group. In an embodiment of the present application, the structure formula of the dibasic alcohol can be HO-R5-OH. Wherein, R5 can be but not limited to an aliphatic group, an alicyclic group, or an aromatic group.

[0079] In an embodiment of the present application, the end-capping agent includes at least one of benzyl alcohol, phenol, p-cresol, and cyclohexylmethanol. In an embodiment of the present application, the structure formula of the end-capping agent can be HO-R6. Wherein, R6 can be but not limited to an aliphatic group, an alicyclic group, or an aromatic group.

[0080] In the present application, at least one of the unsaturated dibasic acid and the unsaturated dibasic anhydride, at least one of the saturated dibasic acid and the saturated dibasic anhydride, and the dibasic alcohol are reacted to generate the unsaturated polyester resin, the amide alcohol is added to modify the polyester resin main chain to have the amide group, and the end-capping agent is added to control the molecular weight of the amide-modified unsaturated polyester resin.

[0081] In an embodiment of the present application, the mass ratio of the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol is (11-22):(6-15):(13-25):(5-15):(2-10). It can be understood that when the reactants of the amide-modified unsaturated polyester resin contain unsaturated dibasic acid or unsaturated dibasic anhydride, the mass ratio is only the mass of the single substance, when the reactants of the amide-modified unsaturated polyester resin contain unsaturated dibasic acid and unsaturated dibasic anhydride, the mass ratio is the sum of the mass of the two substances; when the reactants of the amide-modified unsaturated polyester resin contain saturated dibasic acid or saturated dibasic anhydride, the mass ratio is only the mass of the single substance, when the reactants of the amide-modified unsaturated polyester resin contain saturated dibasic acid and saturated dibasic anhydride, the mass ratio is the sum of the mass of the two substances. By controlling the mass ratio of the acid, the alcohol and the end-capping agent, the molecular weight of the amide-modified unsaturated polyester resin is better controlled, and at the same time, the proportion of the amide alcohol is controlled, so that the problem of excessive viscosity of the amide-modified unsaturated polyester resin caused by the introduction of too many amide groups is avoided, and the overall performance of the amide-modified unsaturated polyester resin can be effectively improved. In another embodiment of the present application, the mass ratio of the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol is (13-20):(7-14):(15-21):(7-12):(3-8). This is conducive to further obtaining an amide-modified unsaturated polyester resin with excellent performance. In still another embodiment of the present application, the mass ratio of the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol is (15-19):(8-13):(16-20):(7-10):(3-7).

[0082] In an embodiment of the present application, the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol can be reacted at 170-215°C (such as 170°C, 180°C, 185°C, 190°C, 200°C, 210°C or 215°C) for 9-16h (such as 10h, 11h, 14h, 15h or 16h). In an example, the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol can be reacted at 185-205°C for 10-15h.

[0083] In another embodiment of the present application, the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol can be reacted at 170-185°C (such as 170°C, 175°C, 180°C, 182°C or 185°C, etc.) for 2-4 hours (such as 2 hours, 2.5 hours, 3 hours or 4 hours), then the temperature is raised to 185-200°C (such as 187°C, 190°C, 194°C, 195°C, 198°C or 200°C, etc.) for 2-4 hours (such as 2 hours, 2.5 hours, 3 hours or 4 hours), and then the temperature is raised to 200-215°C (such as 203°C, 205°C, 208°C, 210°C, 212°C or 215°C, etc.) for 5-10 hours (such as 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours). Since the alcohol has a low boiling point, the viscosity of the whole system is increased at a low temperature, and the saturated vapor pressure is reduced, thereby avoiding the volatilization of the low-boiling-point reactants, and then the reaction is completed at a high temperature. In an embodiment, the at least one of unsaturated dibasic acid and unsaturated dibasic anhydride, the at least one of saturated dibasic acid and saturated dibasic anhydride, the dihydric alcohol, the end-capping agent and the amide alcohol can be reacted at 180-185°C for 2-4 hours, then the temperature is raised to 185-195°C for 2-4 hours, and then the temperature is raised to 200-205°C for 5-10 hours.

[0084] In an embodiment of the present application, the reaction process of the maleic anhydride, the saturated dibasic acid, the dihydric alcohol, the end-capping agent and the amide alcohol for the polycondensation reaction to generate the amide-modified unsaturated polyester resin is as follows:

[0085]

[0086] wherein n represents the degree of polymerization, and n can be greater than or equal to 1. In an embodiment, n can be 1-50. In another embodiment, n can be 1-10. Specifically, n can be, but is not limited to, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, etc.

[0087] It can be understood that the above is only an exemplary reaction process of the amide-modified unsaturated polyester resin, and the specific structure of the amide-modified unsaturated polyester resin can be selected according to the required reactants.

[0088] In an embodiment of the present application, the weight average molecular weight of the amide-modified unsaturated polyester resin is 500-8000. In another embodiment of the present application, the weight average molecular weight of the amide-modified unsaturated polyester resin is 500-3000. In yet another embodiment of the present application, the weight average molecular weight of the amide-modified unsaturated polyester resin is 1000-3000.

[0089] The application also provides an insulating paint, which comprises an amide-modified unsaturated polyester resin, the amide-modified unsaturated polyester resin being prepared by reacting at least one of an unsaturated dibasic acid and an unsaturated dibasic anhydride, at least one of a saturated dibasic acid and a saturated dibasic anhydride, a dibasic alcohol, an end-capping agent, and an amide alcohol, the amide alcohol being prepared by reacting at least one of a dibasic acid chloride and a dibasic acid with a monovalent amine containing a hydroxyl group, and / or the amide alcohol being prepared by reacting a dibasic amine with a monovalent acid containing a hydroxyl group.

[0090] In an embodiment of the application, the amide-modified unsaturated polyester resin in the insulating paint is prepared by the method described in any of the above embodiments.

[0091] In an embodiment of the application, the insulating paint comprises 45-75 parts by weight of the amide-modified unsaturated polyester resin, 25-55 parts by weight of the reactive diluent, 2-5 parts by weight of the initiator, and 0.02-0.06 parts by weight of the polymerization inhibitor. The amide-modified unsaturated polyester resin provided by the application has excellent adhesion, mechanical strength, and wear resistance. By mixing with the reactive diluent and curing under the action of the initiator, the addition of the polymerization inhibitor avoids the curing of the insulating paint before use, thereby ensuring the stability of the insulating paint.

[0092] In the application, the insulating paint comprises 45-75 parts by weight of the amide-modified unsaturated polyester resin, which can effectively improve the performance of the insulating paint while avoiding the problem of excessive content of the amide-modified unsaturated polyester resin affecting the viscosity of the insulating paint. The use of the amide-modified unsaturated polyester resin in the above weight parts can improve the adhesion strength, mechanical properties, and wear resistance after curing of the insulating paint, thereby facilitating the use of the insulating paint. Specifically, the insulating paint can but is not limited to comprising 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, or 75 parts by weight of the amide-modified unsaturated polyester resin. In an embodiment, the insulating paint comprises 45-60 parts by weight of the amide-modified unsaturated polyester resin. In another embodiment, the insulating paint comprises 55-75 parts by weight of the amide-modified unsaturated polyester resin. In yet another embodiment, the insulating paint comprises 50-70 parts by weight of the amide-modified unsaturated polyester resin.

[0093] In the present application, the insulating paint includes 25-45 parts by weight of active diluent, which can copolymerize with the amide-modified unsaturated polyester resin, ensure sufficient curing of the insulating paint, and at the same time play a certain adjusting role on the viscosity of the insulating paint. Specifically, the insulating paint can include, but is not limited to, 25 parts by weight, 28 parts by weight, 30 parts by weight, 33 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight or 50 parts by weight of active diluent. In an embodiment, the insulating paint includes 25-35 parts by weight of active diluent. In another embodiment, the insulating paint includes 30-40 parts by weight of active diluent. In yet another embodiment, the insulating paint includes 35-45 parts by weight of active diluent. In an embodiment of the present application, the boiling point of the active diluent is greater than 200°C. The active diluent with high boiling point can be less or almost not volatile during the curing process, so that the insulating paint has less solid volatile matter and is an environmentally friendly product. Specifically, the boiling point of the active diluent can be, but is not limited to, greater than 210°C, 215°C, 220°C, 230°C or 240°C, etc. In an embodiment of the present application, the active diluent includes at least one of diallyl phthalate, diallyl isophthalate, divinyl toluene, triethylene glycol dimethacrylate, 1,6-hexanedioic acid dipropenoate and lauryl methacrylate.

[0094] In an embodiment of the present application, the total parts by weight of the amide-modified unsaturated polyester resin and the active diluent is 100 parts by weight, which is beneficial to improve the performance of the cured insulating paint.

[0095] In the present application, the insulating paint includes 2-5 parts by weight of initiator, which can ensure sufficient curing of the insulating paint, thereby helping to improve the performance of the cured insulating paint. Specifically, the insulating paint can include, but is not limited to, 2 parts by weight, 3 parts by weight, 4 parts by weight or 5 parts by weight of initiator. In an embodiment, the insulating paint includes 2-3 parts by weight of initiator. In another embodiment, the insulating paint includes 3-4 parts by weight of initiator. In yet another embodiment, the insulating paint includes 4-5 parts by weight of initiator. In an embodiment of the present application, the initiator includes at least one of dicumyl peroxide, benzoyl peroxide and tert-butyl peroxybenzoate.

[0096] In the present application, the insulating paint comprises 0.02-0.06 parts by weight of polymerization inhibitor, which can ensure the stability of the insulating paint before curing. Specifically, the insulating paint may, but not limited to, comprise 0.02 parts by weight, 0.03 parts by weight, 0.04 parts by weight, 0.05 parts by weight or 0.06 parts by weight of initiator. In an embodiment, the insulating paint comprises 0.02-0.04 parts by weight of polymerization inhibitor. In another embodiment, the insulating paint comprises 0.03-0.05 parts by weight of polymerization inhibitor. In yet another embodiment, the insulating paint comprises 0.04-0.06 parts by weight of polymerization inhibitor. In an embodiment of the present application, the polymerization inhibitor comprises at least one of tert-butyl pyrocatechol, hydroquinone and p-benzoquinone.

[0097] In the present application, the amide-modified unsaturated polyester resin, the reactive diluent, the initiator and the polymerization inhibitor are mixed by weight parts to obtain the insulating paint. In an embodiment of the present application, the amide-modified unsaturated polyester resin, the reactive diluent and the polymerization inhibitor are mixed by weight parts uniformly, and then the initiator is added to obtain the insulating paint; in this way, the reaction during the preparation of the insulating paint can be avoided, thereby ensuring the stability of the prepared insulating paint. In an embodiment, the amide-modified unsaturated polyester resin, the reactive diluent and the polymerization inhibitor can be mixed by weight parts at 80-110°C for 1-2 hours, cooled to 40-55°C, and then the initiator is added and mixed at 1-2 hours to obtain the insulating paint; in this way, the components can be fully mixed uniformly. In another embodiment, the amide-modified unsaturated polyester resin, the reactive diluent and the polymerization inhibitor can be mixed by weight parts at 90-110°C, stirred at 80-90°C for 1-2 hours, cooled to 40-55°C, and then the initiator is added and mixed at 48-52°C for 1-2 hours to obtain the insulating paint.

[0098] In an embodiment of the present application, the viscosity of the insulating paint is 1300-1700 mpa·s, which is conducive to the use of the insulating paint. In the present application, the viscosity is measured at 25°C. In an embodiment of the present application, the solid volatile content of the insulating paint is less than 2 wt%. The insulating paint provided by the present application is an environmentally friendly product, has less volatile components, is green and environmentally friendly, and is conducive to the use of the insulating paint.

[0099] In an embodiment of the present application, the bonding strength of the cured insulating paint is greater than 210 N under the detection condition of 25°C. In an embodiment, the bonding strength of the cured insulating paint is greater than 220 N under the detection condition of 25°C. In another embodiment, the bonding strength of the cured insulating paint is greater than 250 N under the detection condition of 25°C. In yet another embodiment, the bonding strength of the cured insulating paint is greater than 260 N under the detection condition of 25°C. In another embodiment of the present application, the bonding strength of the cured insulating paint is greater than 80 N under the detection condition of 155°C.

[0100] In an embodiment of the present application, the cured insulating paint has a tensile strength greater than 30 MPa. In an embodiment, the cured insulating paint has a tensile strength greater than or equal to 31 MPa. In an embodiment of the present application, the cured insulating paint has a bending strength greater than 80 MPa. In an embodiment, the cured insulating paint has a bending strength greater than 81 MPa. In another embodiment, the cured insulating paint has a bending strength greater than or equal to 82 MPa.

[0101] In an embodiment of the present application, the cured insulating paint has a static friction coefficient of the surface less than 0.9. In an embodiment, the cured insulating paint has a static friction coefficient of the surface less than 0.8. In another embodiment, the cured insulating paint has a static friction coefficient of the surface less than 0.85. In yet another embodiment, the cured insulating paint has a static friction coefficient of the surface less than 0.7.

[0102] The insulating paint provided by the present application can form a bond with other structures by adding an amide-modified unsaturated polyester resin, such as forming a hydrogen bond, etc., so that the insulating paint has excellent adhesion. At the same time, the addition of the amide-modified unsaturated polyester resin also improves the mechanical strength and wear resistance of the insulating paint. The organic volatile content of the insulating paint is extremely low, which is green and environmentally friendly. At the same time, the insulating paint has electrical insulation, which is beneficial to use in fields with insulation requirements.

[0103] The present application also provides the use of the above-mentioned insulating paint in a motor. The insulating paint can be filled into the gap between the stator winding and the coil of the motor to bond the stator winding and the coil into a whole, improve the electrical insulation, mechanical strength and bonding reliability of the stator winding and the coil, and is beneficial to improve the power of the motor. In the present application, the motor can be used in a vehicle, but is not limited thereto. The power of the motor can be improved, thereby improving the use performance of the vehicle, and being beneficial to the use of the vehicle.

[0104] The technical solutions of the present application are further described below through specific examples and comparative examples.

[0105] Example 1

[0106] 0.5 mol of isophthaloyl chloride was placed in a three-necked flask, and 150 ml of N,N-dimethylformamide (DMF) was added and stirred to dissolve, then a DMF solution containing 1 mol of 3-amino-1-propanol (concentration of 1 mol / 60 ml) was added dropwise, and stirred at about 0°C for 2 h, then reacted at room temperature of 25°C for 3 h, 1000 ml of ethyl acetate was added for precipitation, filtered, washed and dried to obtain amide alcohol.

[0107] In a clean four-necked flask equipped with a temperature sensor, a stirrer, a distillation and heating device, 18 parts by weight of maleic anhydride, 3 parts by weight of phthalic anhydride, 11 parts by weight of adipic acid, 13 parts by weight of 1,3-butanediol, 7 parts by weight of 1,3-propanediol, 10 parts by weight of benzyl alcohol and 3 parts by weight of the amidoalcohol prepared above were added, and the mixture was reacted at a temperature gradually increased from room temperature to 185°C for 3 hours, then increased to 195°C for 3 hours, and finally increased to 205°C for 8 hours, until the acid value was reduced to less than 50 mgKOH / g. The vacuum was applied until the acid value was reduced to less than 25 mgKOH / g, and the reaction was terminated to obtain an amide-modified unsaturated polyester resin. The temperature was reduced to 110°C, 0.02 parts by weight of hydroquinone was added, followed by 35 parts by weight of 1,6-hexanediol diacrylate, and then the mixture was stirred at 85°C for 1 hour. After cooling to 50°C, 3 parts by weight of dicumyl peroxide was added, and the mixture was stirred at 50°C for 1 hour to obtain an insulating paint.

[0108] Example 2

[0109] The amidoalcohol was prepared by adding 0.5 mol of terephthaloyl chloride to a three-necked flask, stirring and dissolving the mixture in 150 ml of DMF, and then adding a solution of 1 mol of isopropanolamine in DMF (concentration of 1 mol / 60 ml) dropwise. The mixture was stirred at a temperature of about 0°C for 2 hours, and then at room temperature of 25°C for 3 hours. 1000 ml of ethyl acetate was added to precipitate the product, which was filtered, washed and dried.

[0110] In a clean four-necked flask equipped with a temperature sensor, a stirrer, a distillation and heating device, 15 parts by weight of maleic anhydride, 3 parts by weight of isophthalic acid, 9 parts by weight of adipic acid, 9 parts by weight of 1,3-butanediol, 10 parts by weight of diethylene glycol, 8 parts by weight of benzyl alcohol and 4 parts by weight of the amidoalcohol prepared above were added, and the mixture was reacted at a temperature gradually increased from room temperature to 185°C for 3 hours, then increased to 195°C for 3 hours, and finally increased to 205°C for 8 hours, until the acid value was reduced to less than 50 mgKOH / g. The vacuum was applied until the acid value was reduced to less than 25 mgKOH / g, and the reaction was terminated to obtain an amide-modified unsaturated polyester resin. The temperature was reduced to 110°C, 0.03 parts by weight of hydroquinone was added, followed by 42 parts by weight of triethylene glycol dimethacrylate, and then the mixture was stirred at 85°C for 1 hour. After cooling to 50°C, 2 parts by weight of tert-butyl peroxybenzoate was added, and the mixture was stirred at 50°C for 1 hour to obtain an insulating paint.

[0111] Example 3

[0112] Put 0.5 mol of isophthalic acid in a three-necked flask, and add 150 ml of DMF to stir and dissolve the mixture, then add 1 mol of 3-amino-1-propanol dropwise, stir and react at 150°C for 2 h, then react at room temperature at 210°C for 3 h, add 1000 ml of ethyl acetate to precipitate, filter, wash and dry to obtain amido alcohol.

[0113] Put 16 parts by weight of maleic anhydride, 4 parts by weight of phthalic anhydride, 7 parts by weight of adipic acid, 17 parts by weight of 1,3-butanediol, 8 parts by weight of benzyl alcohol, and 5 parts by weight of the amido alcohol prepared above in a clean four-necked flask equipped with a temperature sensor, a stirrer, a distillation and heating device, and react for 3 h while gradually increasing the temperature from room temperature to 185°C, then increase the temperature to 195°C for 3 h, and finally increase the temperature to 205°C for 8 h, until the acid value is reduced to below 50 mgKOH / g, vacuumize until the acid value is reduced to below 25 mgKOH / g, and end the reaction to obtain an amide-modified unsaturated polyester resin. Reduce the temperature to 110°C, and sequentially add 0.02 parts by weight of hydroquinone, 43 parts by weight of 1,6-adipic acid diacrylate, then stir at 85°C for 1 h; cool to 50°C, add 2 parts by weight of t-butyl peroxybenzoate, and stir at 50°C for 1 h to obtain an insulating paint.

[0114] Example 4

[0115] Put 0.5 mol of isophthalic acid in a three-necked flask, and add 150 ml of DMF to stir and dissolve the mixture, then add 1 mol of 3-amino-1-propanol dropwise, stir and react at 150°C for 2 h, then react at room temperature at 210°C for 3 h, add 1000 ml of ethyl acetate to precipitate, filter, wash and dry to obtain amido alcohol.

[0116] Put 15 parts by weight of maleic anhydride, 3 parts by weight of isophthalic acid, 8 parts by weight of adipic acid, 9 parts by weight of 1,3-butanediol, 8 parts by weight of benzyl alcohol, and 6 parts by weight of the amido alcohol prepared above in a clean four-necked flask equipped with a temperature sensor, a stirrer, a distillation and heating device, and react for 3 h while gradually increasing the temperature from room temperature to 185°C, then increase the temperature to 195°C for 3 h, and finally increase the temperature to 205°C for 8 h, until the acid value is reduced to below 50 mgKOH / g, vacuumize until the acid value is reduced to below 25 mgKOH / g, and end the reaction to obtain an amide-modified unsaturated polyester resin. Reduce the temperature to 110°C, and sequentially add 0.03 parts by weight of hydroquinone, 44 parts by weight of triethylene glycol dimethacrylate, then stir at 85°C for 1 h; cool to 50°C, add 4 parts by weight of dicumyl peroxide, and stir at 50°C for 1 h to obtain an insulating paint.

[0117] Example 5

[0118] Put 0.5 mol of m-phenylenediamine in a three-necked flask, and add 100 ml of DMF to stir and dissolve the mixture, then add 1 mol of 3-hydroxypropionic acid, stir and react at 150°C for 2 h, then react at room temperature for 3 h at 210°C, add 1000 ml of ethyl acetate to precipitate, filter, wash and dry to obtain amide alcohol.

[0119] Put 15 parts by weight of maleic anhydride, 1 part by weight of phthalic anhydride, 9 parts by weight of adipic acid, 15 parts by weight of 1,3-butanediol, 9 parts by weight of benzyl alcohol, and 7 parts by weight of the amide alcohol prepared above in a clean three-necked flask equipped with a temperature sensor, a stirrer, a distillation and heating device, and react for 3 h while gradually increasing the temperature from room temperature to 185°C, then for 3 h while increasing the temperature to 195°C, and finally for 8 h while increasing the temperature to 205°C, until the acid value is reduced to below 50 mgKOH / g, and then vacuumize until the acid value is reduced to below 25 mgKOH / g to end the reaction, thereby obtaining an amide-modified unsaturated polyester resin. Reduce the temperature to 110°C, and then sequentially add 0.03 parts by weight of hydroquinone, 44 parts by weight of 1,6-adipic acid dipropyl acrylate, and then stir for 1 h at 85°C; cool to 50°C, add 2 parts by weight of t-butyl peroxybenzoate, and then stir for 1 h at 50°C, thereby obtaining an insulating paint.

[0120] Comparative Example 1

[0121] Put 18 parts by weight of maleic anhydride, 3 parts by weight of phthalic anhydride, 11 parts by weight of adipic acid, 13 parts by weight of 1,3-butanediol, 7 parts by weight of 1,3-propanediol, 10 parts by weight of benzyl alcohol, and 1 part by weight of 1,4-butanediol in a clean three-necked flask equipped with a temperature sensor, a stirrer, a distillation and heating device, and react for 3 h while gradually increasing the temperature from room temperature to 185°C, then for 3 h while increasing the temperature to 195°C, and finally for 8 h while increasing the temperature to 205°C, until the acid value is reduced to below 50 mgKOH / g, and then vacuumize until the acid value is reduced to below 25 mgKOH / g to end the reaction, thereby obtaining an unsaturated polyester resin. Reduce the temperature to 110°C, and then sequentially add 0.02 parts by weight of hydroquinone, 35 parts by weight of 1,6-adipic acid dipropyl acrylate, and then stir for 1 h at 85°C; cool to 50°C, add 3 parts by weight of dicumyl peroxide, and then stir for 1 h at 50°C, thereby obtaining an insulating paint.

[0122] Comparative Example 2

[0123] In a clean four-necked flask with temperature sensor, stirrer, distillation and heating device, 15 parts by weight of maleic anhydride, 3 parts by weight of isophthalic acid, 8 parts by weight of adipic acid, 9 parts by weight of 1,3-butanediol, 2 parts by weight of diethylene glycol, 8 parts by weight of benzyl alcohol and 7 parts by weight of 1,4-butanediol were added, and the reaction was carried out at a temperature gradually increasing from room temperature to 185°C for 3h, then increasing to 195°C for 3h, and finally increasing to 205°C for 8h until the acid value was reduced to below 50mgKOH / g, vacuum was applied until the acid value was reduced to below 25mgKOH / g, and the reaction was terminated to obtain an unsaturated polyester resin. The temperature was reduced to 110°C, 0.03 parts by weight of hydroquinone was added, followed by 44 parts by weight of triethylene glycol dimethacrylate, and then stirred at 85°C for 1h; cooled to 50°C, 4 parts by weight of dicumyl peroxide was added, and stirred at 50°C for 1h to obtain an insulating paint.

[0124] Performance test

[0125] The viscosity of the insulating paint prepared in the examples and comparative examples was detected according to GB / T 15022.2-2017. The solid volatile content of the insulating paint prepared in the examples and comparative examples was detected according to GB / T 15022.2-2017. The insulating paint prepared in the examples and comparative examples was impregnated into the same specification of New coil and cured at 150°C for 2h, and the bonding strength was detected according to GB / T 11028-1999. The tensile strength and bending strength of the insulating paint prepared in the examples and comparative examples after curing were detected according to GB / T 2567-2008. The static friction coefficient of the insulating paint prepared in the examples and comparative examples after curing was detected according to GB / T 10006-1988. The above detection results are shown in Table 1.

[0126] Table 1 Performance test results

[0127]

[0128] It can be seen that compared with Comparative Example 1-2, the viscosity of the insulating paint provided by the examples of the present application is suitable, the solid volatile content is less than 2%, it is more green and environmentally friendly, the bonding strength at different test temperatures is all improved, at the same time, it also has excellent tensile strength and bending strength, the mechanical properties are also improved, and the static friction coefficient is small, it is more wear-resistant. Therefore, by adding amide modified unsaturated polyester resin, the bonding strength, tensile strength, bending strength and wear resistance of the insulating paint are improved, the overall performance of the insulating paint is improved, which is conducive to the use of the insulating paint.

[0129] The above-described embodiments are merely illustrative of several embodiments of the present application, which are described in more detail and in a specific manner, but should not be construed as limiting the scope of the patent of the present application. It should be noted that, for those of ordinary skill in the art, several modifications 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 of the present application should be subject to the appended claims.

Claims

1. A method for preparing an amide-modified unsaturated polyester resin, characterized in that: include: reacting at least one of a dibasic acid chloride and a dibasic acid with a hydroxyl-containing monoamine, and / or reacting a diamine with a hydroxyl-containing monoacid to obtain an amide alcohol; At least one of an unsaturated dibasic acid and an unsaturated dibasic acid anhydride, at least one of a saturated dibasic acid and a saturated dibasic acid anhydride, a diol, a blocking agent and the amide alcohol are reacted to obtain an amide-modified unsaturated polyester resin, wherein the dibasic acid comprises at least one of terephthalic acid, isophthalic acid and adipic acid; the hydroxyl-containing monoamine comprises at least one of isopropanolamine, 3-amino-1-propanol and monoethanolamine; the diamine comprises isophorone diamine, p-phenylenediamine, m-phenylenediamine, 4,4-diaminodiphenylmethane at least one of alkanes and 4,4-diaminodiphenyl ether; the hydroxyl-containing monobasic acid includes at least one of 3-hydroxypropionic acid, 2-hydroxypropionic acid, hydroxybenzoic acid, hydroxyphenylacetic acid and hydroxyphenoxyacetic acid; the unsaturated dibasic acid includes at least one of maleic acid and fumaric acid; the unsaturated dibasic acid anhydride includes at least one of maleic anhydride and fumaric anhydride; the saturated dibasic acid includes at least one of terephthalic acid, isophthalic acid, adipic acid and succinic acid; the saturated dibasic acid anhydride includes phthalic anhydride.

2. The preparation method according to claim 1, wherein The amide alcohol has an asymmetric structure.

3. The preparation method according to claim 1, wherein The molar ratio of at least one of the dibasic acid chloride and the dibasic acid to the hydroxyl-containing monoamine is 1:(2-2.5); The molar ratio of the diamine to the hydroxyl-containing monoacid is 1:(2-2.5); The mass ratio of at least one of the unsaturated dibasic acid and the unsaturated dibasic acid anhydride, at least one of the saturated dibasic acid and the saturated dibasic acid anhydride, the diol, the end-capping agent and the amide alcohol is (11-22): (6-15): (13-25): (5-15): (2-10).

4. The preparation method according to claim 1, wherein The molar ratio of at least one of the dibasic acid chloride and the dibasic acid to the hydroxyl-containing monoamine is 1:(2-2.2); The molar ratio of the diamine to the hydroxyl-containing monoacid is 1:(2-2.2); The mass ratio of at least one of the unsaturated dibasic acid and the unsaturated dibasic acid anhydride, at least one of the saturated dibasic acid and the saturated dibasic acid anhydride, the diol, the end-capping agent and the amide alcohol is (13-20): (7-14): (15-21): (7-12): (3-8).

5. The preparation method according to claim 1, wherein The dibasic acid chloride comprises at least one of terephthaloyl chloride, isophthaloyl chloride, adipoyl chloride and succinoyl chloride; The diol includes at least one of ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, neopentyl glycol and bisphenol A; The end-capping agent includes at least one of benzyl alcohol, phenol, p-cresol and cyclohexylmethanol.

6. An insulating varnish, characterized in that: The invention comprises the amide-modified unsaturated polyester resin according to any one of claims 1 to 5.

7. The insulating varnish according to claim 6, characterized in that In parts by weight, the insulating varnish comprises 45 to 75 parts of the amide-modified unsaturated polyester resin, 25 to 55 parts of a reactive diluent, 2 to 5 parts of an initiator, and 0.02 to 0.06 parts of a polymerization inhibitor.

8. The insulating varnish according to claim 7, characterized in that The boiling point of the reactive diluent is greater than 200°C.

9. The insulating varnish according to claim 7, characterized in that The reactive diluent includes at least one of diallyl phthalate, diallyl isophthalate, divinyl toluene, triethylene glycol dimethacrylate, 1,6-adipate diacrylate and lauryl methacrylate; The initiator comprises at least one of dicumyl peroxide, benzoyl peroxide and tert-butyl perbenzoate; The polymerization inhibitor includes at least one of tert-butylcatechol, hydroquinone and benzoquinone.

10. Use of the insulating varnish according to any one of claims 6 to 9 in a motor.

Images