Adhesive and preparation method thereof, cross-linked polymer, composite insulation paper and oil-cooled motor

Abstract

The invention relates to an adhesive and a preparation method thereof, a cross-linked polymer, composite insulation paper and an oil-cooled motor, the adhesive comprises the following raw materials: acrylic resin, epoxy resin and a curing agent, the mass ratio of the acrylic resin to the epoxy resin to the curing agent is (35-63): (1-5): (6-15), the glass transition temperature of the acrylic resin is-30 DEG C to-10 DEG C. By controlling the ratio of the acrylic resin with the glass transition temperature Tg of-30 DEG C to-10 DEG C to the epoxy resin in the adhesive, the glass transition temperature Tg of a cross-linked polymer obtained after the adhesive is hardened can be 0-20 DEG C, so that when the adhesive is applied to the multi-layer composite insulation paper, the cross-linked polymer can be cured at the temperature of-30 DEG C to-10 DEG C; the glass transition temperature Tg of the multi-layer composite insulation paper is 0-20 DEG C, so that the stiffness of the composite insulation paper can be adjusted to a proper range.

Description

Technical Field

[0001] The present application relates to the technical field of insulating paper, and in particular to an adhesive and a preparation method thereof, a cross-linked polymer, a composite insulating paper, and an oil-cooled motor. Background Art

[0002] The motors of traditional new energy vehicles are water-cooled motors, and the insulation paper they use is generally NHN insulation paper (where N is NOMEX paper and H is polyimide film), and the glue used is polyurethane glue. The NHN insulation paper is economical and has good heat resistance, with an insulation heat resistance grade of ≥180℃.

[0003] However, with the development of new energy vehicles, water-cooled motors are gradually replaced by oil-cooled motors. The polyurethane glue in NHN insulation paper has poor oil resistance and is very easy to swell in oil, and even disperse in oil, resulting in stratification of insulation paper. Existing adhesives such as epoxy resins have good oil resistance, but often have high stiffness after use. In particular, in order to protect the resin film layer in the middle, a thicker adhesive layer is required to make the stiffness greater. Too much or too little stiffness will affect installation during actual application and installation, which is not conducive to use. Summary of the invention

[0004] In view of this, the present application provides an adhesive and a preparation method thereof, a cross-linked polymer, a composite insulating paper, and an oil-cooled motor, aiming to adjust the stiffness value of the existing insulating paper to an appropriate range (lateral stiffness is 60N~90N, and longitudinal stiffness is 40N~65N).

[0005] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, an adhesive is provided, comprising the following raw materials: an acrylic resin, an epoxy resin and a curing agent, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63): (1-5): (6-15), and the glass transition temperature of the acrylic resin is -30°C to -10°C.

[0006] Optionally, the adhesive further comprises an epoxy reactive diluent, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the epoxy reactive diluent is (35-63): (1-5): (6-15): (1-9); and / or

[0007] The adhesive further comprises an accelerator, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the accelerator is (35-63): (1-5): (6-15): (0.1-0.5); and / or

[0008] The adhesive also includes a solvent, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the solvent is (35-63): (1-5): (6-15): (32-55).

[0009] Optionally, the adhesive further comprises the following raw materials: epoxy reactive diluent, curing agent, accelerator and solvent.

[0010] Optionally, the mass ratio of the acrylic resin, the epoxy resin, the epoxy reactive diluent, the curing agent, the accelerator and the solvent is (42-54): (3-5): (5-6): (9-12): (0.25-0.5): (35.75-41.75).

[0011] Optionally, the acrylic resin includes one or more of acrylic acid ester polymers and polyethyl acrylates.

[0012] Optionally, the epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, phenol epoxy resin and biphenyl epoxy resin; and / or

[0013] The epoxy reactive diluent includes one or more of C8-C22 glycidyl ether and C8-C22 glycidyl ester; and / or

[0014] The curing agent includes one or more of tung oil anhydride, dodecenyl anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride; and / or

[0015] The accelerator includes one or more of a tertiary amine accelerator, an imidazole curing agent and a dicyandiamide accelerator; and / or

[0016] The solvent includes one or more of xylene, methyl isobutyl ketone, ethylene glycol butyl ether, butyl acetate, cyclohexanone, and ethyl acetate.

[0017] According to a second aspect of the present application, a method for preparing an adhesive is provided, comprising the following steps:

[0018] Providing epoxy resin and acrylic resin, performing a first mixing to obtain component A, wherein the acrylic resin has a glass transition temperature of -30°C to -10°C;

[0019] providing a curing agent to obtain a B component;

[0020] After the A component and the B component are mixed for the second time, an adhesive is obtained, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63): (1-5): (6-15).

[0021] Optionally, the component A further comprises an epoxy reactive diluent, and the first mixing comprises: mixing and stirring the epoxy resin and the epoxy reactive diluent for 30 to 60 minutes, and then adding the acrylic resin and continuing to mix and stir for 30 to 60 minutes; and / or

[0022] The B component further comprises a solvent, and the curing agent is dissolved in the solvent; and / or

[0023] The B component further comprises a promoter, and the promoter is added in a manner including dropwise addition; and / or

[0024] The cross-linking reaction temperature of the adhesive is 40 to 80° C., and the cross-linking reaction time of the adhesive is 4 to 8 hours; and / or

[0025] The second mixing time is 15 to 30 minutes; and / or

[0026] The second mixing further comprises: vacuum degassing for 4 to 6 minutes or static degassing for 25 to 35 minutes.

[0027] According to a third aspect of the present application, a cross-linked polymer is also provided, which is obtained by hardening the above-mentioned adhesive or the adhesive obtained by the above-mentioned preparation method.

[0028] Optionally, the glass transition temperature of the cross-linked polymer is 0°C to 20°C.

[0029] According to a fourth aspect of the present application, a composite insulating paper is further provided, the composite insulating paper comprising a first fiber paper, a first adhesive layer, a resin film, a second adhesive layer and a second fiber paper which are stacked;

[0030] The first adhesive layer and / or the second adhesive layer are prepared from the above-mentioned adhesive or the above-mentioned cross-linked polymer or the above-mentioned preparation method.

[0031] Optionally, the composite insulating paper further comprises a first fiber paper, a resin film and a second fiber paper which are stacked, and the adhesive is arranged between the first fiber paper and the resin film, and between the second fiber paper and the resin film.

[0032] Optionally, the glass transition temperature of the composite insulating paper is 0°C to 20°C; and / or

[0033] The transverse stiffness of the composite insulating paper is in the range of 60N to 90N; and / or

[0034] The longitudinal stiffness of the composite insulating paper ranges from 40N to 65N.

[0035] Optionally, the first fiber paper comprises one or more of polyaramid fiber paper, polyester fiber paper, polysulfone amide fiber paper, and inorganic fiber paper; and / or

[0036] The second fiber paper comprises one or more of polyaramid fiber paper, polysulfoneamide fiber paper, and inorganic fiber paper; and / or

[0037] The resin film is a polyester film, a polyimide film, a polyethylene terephthalate film, a polyethylene naphthalate film, or a polyphenylene sulfide film.

[0038] According to a fifth aspect of the present application, there is also provided an oil-cooled motor, comprising the above-mentioned composite insulating paper or the composite insulating paper prepared by the above-mentioned preparation method.

[0039] In the present application, by controlling the ratio of acrylic resin and epoxy resin having a glass transition temperature Tg of -30°C to -10°C in the adhesive, the glass transition temperature Tg of the cross-linked polymer obtained after the adhesive is hardened can be between 0°C and 20°C, and then when the adhesive is applied to multi-layer composite insulating paper, the glass transition temperature Tg of the multi-layer composite insulating paper is between 0°C and 20°C, so that the stiffness of the composite insulating paper can be adjusted to an appropriate range (lateral stiffness is 60N to 90N, and longitudinal stiffness is 40N to 65N).

[0040] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 This is a diagram of the blistering and layering of the composite insulating paper provided in Example 10 of the present invention. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0045] In this application, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order.

[0046] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0047] In the present application, "at least one" means one or more, and "plurality" means two or more. "One or more", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0048] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0049] The technical solution of this application is as follows:

[0050] In a first aspect, an embodiment of the present application provides an adhesive comprising the following raw materials: an acrylic resin, an epoxy resin and a curing agent, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63): (1-5): (6-15), and the glass transition temperature of the acrylic resin is -30°C to -10°C.

[0051] In the present application, by controlling the ratio of acrylic resin and epoxy resin with a glass transition temperature Tg of -30°C to -10°C in the adhesive, the glass transition temperature Tg of the cross-linked polymer obtained after the adhesive is hardened can be between 0°C and 20°C, and then when the adhesive is applied to multi-layer composite insulating paper, the glass transition temperature Tg of the multi-layer composite insulating paper is between 0°C and 20°C, thereby adjusting the stiffness of the composite insulating paper to a suitable range (lateral stiffness is 60N to 90N, and longitudinal stiffness is 40N to 65N). At the same time, when the adhesive is applied to multi-layer composite insulating paper, the epoxy resin has good oil resistance, and will not swell or peel off during oil immersion. The acrylic resin can improve the toughness of the adhesive and delay the brittleness of the glue during long-term oil immersion, thereby improving the service life of the composite paper. The curing agent can undergo a cross-linking reaction with acrylic resin and epoxy resin. By controlling the mass ratio of acrylic resin, epoxy resin and curing agent, the degree of cross-linking of acrylic resin and epoxy resin can be made between 0.8 and 1.2, thereby effectively improving the heat resistance and oil resistance of the adhesive.

[0052] It should be noted that the acrylic resin in the present application is viscous, so as to improve the initial tack of the adhesive. Since the acrylic resin itself usually contains a solvent, the acrylic resin in the present application is still viscous after the solvent is removed.

[0053] In some embodiments, the acrylic resin has a glass transition temperature of -25°C to -15°C.

[0054] In some embodiments, the acrylic resin has a glass transition temperature of -21°C to -18°C.

[0055] In some embodiments, the adhesive further includes an epoxy reactive diluent, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent, and the epoxy reactive diluent is (35-63): (1-5): (6-15): (1-9). In this way, the epoxy reactive diluent can adjust the viscosity of the adhesive and improve the toughness of the cross-linked polymer, thereby adjusting the stiffness of the composite insulating paper to a suitable range (transverse stiffness of 60N-90N, longitudinal stiffness of 40N-65N).

[0056] In some embodiments, the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the accelerator is (35-63): (1-5): (6-15): (0.1-0.5). Thus, the accelerator can reduce the temperature of the cross-linking reaction and increase the rate of the cross-linking reaction.

[0057] In some embodiments, the adhesive further comprises a solvent, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the solvent is (35-63): (1-5): (6-15): (32-55). In this way, the solvent can adjust the viscosity of the adhesive so that it is more suitable for production line production.

[0058] In some embodiments, the adhesive further comprises the following raw materials: epoxy reactive diluent, curing agent, accelerator and solvent.

[0059] In some embodiments, the mass ratio of the acrylic resin, the epoxy resin, the epoxy reactive diluent, the curing agent, the accelerator and the solvent is (42-54): (3-5): (5-6): (9-12): (0.25-0.5): (35.75-41.75).

[0060] In some embodiments, the acrylic resin includes one or more of acrylic acid ester polymers and polyethyl acrylate polymers.

[0061] In some embodiments, the epoxy reactive diluent includes one or more of C8-C22 glycidyl ether and C8-C22 glycidyl ester. This epoxy reactive diluent has a relatively good improvement in the flexibility of epoxy resin. C8-C22 glycidyl ether refers to glycidyl ether containing 8-22 carbon atoms, such as 1,4-butanediol diglycidyl ether, propylene glycol triglycidyl ether, ethylene glycol diglycidyl ether, etc., and C8-C22 glycidyl ester refers to glycidyl ester containing 8-22 carbon atoms, such as diglycidyl phthalate, hexahydrophthalic acid diglycidyl ester, adipic acid diglycidyl ester, etc.

[0062] In the present application, epoxy reactive diluent and acrylic resin can both improve the toughness of the adhesive, realize the free adjustment of the stiffness of the composite insulating paper, and delay the brittleness of the glue during long-term oil immersion, thereby improving the service life of the composite insulating paper.

[0063] In some embodiments, the epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, phenol epoxy resin and biphenyl epoxy resin.

[0064] In some embodiments, the curing agent includes one or more of tung oil anhydride, dodecenyl anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. In this way, the curing agent has good oil resistance and can improve the oil resistance of the adhesive.

[0065] In the present application, epoxy resin and acrylate resin are compounded and cured with acid anhydride. The resulting adhesive has a high degree of cross-linking, large molecular chain steric hindrance, and good oil resistance; the adhesive has good wetting with the substrate and strong cohesion, thereby improving the bonding effectiveness of the insulating paper.

[0066] In some embodiments, the accelerator includes one or more of a tertiary amine accelerator, an imidazole curing agent, and a dicyandiamide accelerator. This accelerator has a significant promoting effect on high temperature curing epoxy-anhydride system and can also improve the bonding strength of the adhesive.

[0067] In some embodiments, the accelerator is a tertiary amine accelerator.

[0068] In some embodiments, the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0069] In some embodiments, the solvent includes one or more of xylene, methyl isobutyl ketone, ethylene glycol butyl ether, butyl acetate, cyclohexanone, and ethyl acetate. This solvent is a good solvent for the resin and is volatile, suitable for rapid removal on the production line.

[0070] In some embodiments, the solvent is one or both of xylene and butyl acetate.

[0071] In some embodiments, the solvent is ethyl acetate.

[0072] According to a third aspect of the present disclosure, an embodiment of the present application provides a method for preparing an adhesive, comprising the following steps:

[0073] S11, providing epoxy resin and acrylic resin, performing a first mixing to obtain component A, wherein the acrylic resin has a glass transition temperature of -30°C to -10°C;

[0074] S12, providing a curing agent and a solvent, and dissolving the curing agent in the solvent to obtain component B;

[0075] S13. After a second mixing of the component A and the component B, an adhesive is obtained, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63): (1-5): (6-15).

[0076] In the present application, component A and component B react slowly, so they need to be prepared separately and then mixed before use.

[0077] In step S1,

[0078] In some embodiments, the A component further includes an epoxy reactive diluent, and the first mixing includes: mixing the epoxy resin and the epoxy reactive diluent and stirring for 30 to 60 minutes, and then adding the acrylic resin and continuing to mix and stir for 30 to 60 minutes.

[0079] In the present application, the epoxy resin has a relatively high viscosity, and mixing it with the epoxy reactive diluent first can reduce its viscosity and facilitate better mixing.

[0080] In step S2,

[0081] In some embodiments, the B component further comprises an accelerator, and the accelerator is added dropwise, so that a large amount of heat generated during the mixing process of the curing agent and the accelerator can be prevented from causing explosion.

[0082] In some embodiments, the cross-linking reaction temperature of the adhesive is 40-80°C, for example, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, etc., and the cross-linking reaction time of the adhesive is 4-8h, for example, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h. In this way, the gas generated by the reaction of the curing agent and the accelerator can be released faster, which is beneficial to packaging and transportation.

[0083] In step S3,

[0084] In some embodiments, the second mixing time is 15 to 30 minutes, for example, 18 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes, etc.

[0085] In some embodiments, the second mixing further includes: vacuum degassing for 4 to 6 minutes or static degassing for 25 to 35 minutes. In this way, bubbles generated by the air introduced during the mixing and stirring process can be eliminated, which is beneficial to the production and coating of the adhesive.

[0086] The embodiment of the present application provides a cross-linked polymer, which is prepared from the above-mentioned adhesive.

[0087] When the cross-linked polymer of the present application is applied to multi-layer composite insulating paper, the glass transition temperature Tg of the multi-layer composite insulating paper is between 0°C and 20°C, thereby adjusting the stiffness of the composite insulating paper to a suitable range (lateral stiffness is 60N to 90N, longitudinal stiffness is 40N to 65N).

[0088] In some embodiments, the cross-linked polymer has a glass transition temperature of 0°C to 20°C.

[0089] The materials of epoxy resin, epoxy reactive diluent, acrylic resin, curing agent, accelerator and solvent are as described above.

[0090] The embodiment of the present application further provides a composite insulating paper, the composite insulating paper comprising a first fiber paper, a first adhesive layer, a resin film, a second adhesive layer and a second fiber paper which are stacked;

[0091] The first adhesive layer and / or the second adhesive layer are made by hardening the above-mentioned adhesive.

[0092] In the present application, by bonding with the above-mentioned adhesive, the glass transition temperature of the composite insulating paper can be made 0°C to 20°C, thereby adjusting the stiffness of the composite insulating paper to a suitable range, with a transverse stiffness range of 60N to 90N and a longitudinal stiffness range of 40N to 65N.

[0093] In some embodiments, the composite insulating paper further comprises a first fiber paper, a resin film, and a second fiber paper which are stacked, and the adhesive is disposed between the first fiber paper and the resin film, and between the second fiber paper and the resin film.

[0094] In the present application, the fiber paper can provide good high temperature resistance and oil resistance, the adhesive has good oil resistance and can effectively protect the resin film from oil corrosion, and the resin film can provide good mechanical properties and electrical properties.

[0095] In some embodiments, the first fiber paper includes one or more of polyaramid fiber paper, polyester fiber paper, polysulfone amide fiber paper, and inorganic fiber paper. Thus, the fiber paper has good high temperature resistance and oil resistance.

[0096] In some embodiments, the second fiber paper includes one or more of polyaramid fiber paper, polysulfoneamide fiber paper, and inorganic fiber paper. Thus, the fiber paper has good high temperature resistance and oil resistance.

[0097] In some embodiments, the resin film is a polyester film, a polyimide film, a polyethylene terephthalate film, a polyethylene naphthalate film, or a polyphenylene sulfide film. Thus, the resin film can provide good mechanical and electrical properties.

[0098] In some embodiments, the resin film is a polyethylene naphthalate film or a polyphenylene sulfide film.

[0099] In some embodiments, the resin film is a polyethylene naphthalate film.

[0100] According to a fourth aspect of the present disclosure, an embodiment of the present application further provides a method for preparing a composite insulating paper, comprising the following steps:

[0101] A cross-linked polymer, a resin film, a first fiber paper and a second fiber paper are provided. After the cross-linked polymer is respectively arranged on one side surface of the first fiber paper and one side surface of the second fiber paper, the solvent is removed, and then the paper is pressed with the resin film, rolled up, matured and cured, so that the adhesive is arranged between the resin film and the first fiber paper and between the resin film and the second fiber paper, thereby obtaining a composite insulating paper, the cross-linked polymer.

[0102] In some embodiments, the method for removing the solvent is baking, and the baking temperature is set in a gradient between 90 and 120°C, for example, through seven-section oven drying, the drying temperatures are 90°C, 100°C, 110°C, 120°C, 110°C, 100°C, and 90°C, and the baking time is 2-4 minutes. In this way, the solvent can be better removed in a short time, and the initial viscosity of the adhesive can be improved, thereby facilitating bonding.

[0103] In some embodiments, the pressing pressure is 50-70N.

[0104] An embodiment of the present application also provides an oil-cooled motor, which includes the above-mentioned composite insulating paper.

[0105] The present application is described in detail below by means of specific examples, which are only partial examples of the present application and are not intended to limit the present application. The raw materials used in the following examples are all commercially available products unless otherwise specified.

[0106] Example 1

[0107] A method for preparing an adhesive comprises the following steps:

[0108] (1) Add 5 parts of 1,4-butanediol diglycidyl ether to 5 parts by weight of bisphenol A epoxy resin, mix and stir for 30 minutes, then add 80 parts of solvent-containing ethyl acrylate PJ60004-60 (containing 40% solvent and 60% ethyl acrylate with a Tg of -19°C), and stir for 60 minutes to obtain component A;

[0109] (2) adding 9 parts by weight of methyltetrahydrophthalic anhydride to 5.75 parts by weight of ethyl acetate, and then dropwise adding 0.25 parts by weight of 2,4,6-tris(dimethylaminomethyl)phenol, and stirring at a constant temperature of 60° C. for 6 hours to obtain component B;

[0110] (3) Component A and component B are mixed and stirred for 15 to 30 minutes, and then vacuum degassed for 5 minutes to obtain an adhesive.

[0111] A method for preparing a composite insulating paper comprises the following steps:

[0112] (1) using a coating laminating machine to apply the adhesive to the surface of one side of the first polyaramid fiber paper (aramid 1313) and the surface of the second polyaramid fiber paper (aramid 1313), respectively, and then drying them in a seven-section oven for 3 minutes, wherein the drying temperatures of the seven-section oven are 90° C., 100° C., 110° C., 120° C., 110° C., 100° C., and 90° C., respectively;

[0113] (2) compounding the dried first polyaramid fiber paper (aramid 1313) with the polyethylene naphthalate film so that the adhesive is located between the two, and rolling and ripening to obtain roll 1;

[0114] (3) Compounding the dried second polyaramid fiber paper (aramid 1313) with roll 1 so that the adhesive on the second polyaramid fiber paper (aramid 1313) is located between the two, rolling up, and then curing at 100° C. for 2 h and then at 150° C. for 2 h to obtain composite insulating paper.

[0115] Example 2

[0116] This embodiment is substantially the same as Embodiment 1, except that the amount of ethyl acetate used in this embodiment is 5.5 parts by weight, and the amount of 2,4,6-tris(dimethylaminomethyl)phenol used is 0.5 parts by weight.

[0117] Example 3

[0118] This embodiment is basically the same as Embodiment 1, except that, in this embodiment, the amount of bisphenol A epoxy resin used is 4 parts by weight, the amount of 1,4-butanediol diglycidyl ether used is 6 parts by weight, the amount of ethyl acrylate used is 70 parts by weight, the amount of ethyl acetate used is 7.75 parts by weight, and the amount of methyltetrahydrophthalic anhydride used is 12 parts by weight.

[0119] Example 4

[0120] This embodiment is substantially the same as Embodiment 1, except that the amount of bisphenol A epoxy resin used in this embodiment is 3 parts by weight, the amount of ethyl acrylate used is 90 parts by weight, and the amount of methyltetrahydrophthalic anhydride used is 10 parts by weight.

[0121] Example 5

[0122] This embodiment is substantially the same as the embodiment 1, except that the ethyl acrylate PJ60004-60 in the embodiment 1 is replaced by polyethyl acrylate PJ60018-70 (containing 40% solvent and 60% polyethyl acrylate with a Tg of -24°C).

[0123] Example 6

[0124] This embodiment is substantially the same as the embodiment 1, except that the ethyl acrylate PJ60004-60 in the embodiment 1 is replaced by acrylic resin PJ60005-50 (containing 40% solvent and 60% acrylic resin with a Tg of -15°C).

[0125] Example 7

[0126] This embodiment is substantially the same as the embodiment 1, except that the bisphenol A epoxy resin in the embodiment 1 is replaced by a novolac epoxy resin.

[0127] Example 8

[0128] This embodiment is substantially the same as the embodiment 1, except that the bisphenol A epoxy resin in the embodiment 1 is replaced by a biphenyl epoxy resin.

[0129] Example 9

[0130] This embodiment is basically the same as Embodiment 1, except that the drying temperatures of the seven-section ovens in this embodiment are 100°C, 110°C, 120°C, 130°C, 120°C, 110°C, and 100°C, respectively.

[0131] Example 10

[0132] This embodiment is substantially the same as Embodiment 1, except that the amount of 2,4,6-tris(dimethylaminomethyl)phenol used in this embodiment is 0.75 parts by weight, and the amount of ethyl acetate used is 5.25 parts by weight.

[0133] Comparative Example 1

[0134] This comparative example is substantially the same as Example 1, except that ethyl acrylate PJ60004-60 is not added in this comparative example.

[0135] Comparative Example 2

[0136] This comparative example is substantially the same as Example 1, except that the amount of bisphenol A epoxy resin used in this comparative example is 7 parts by weight.

[0137] Comparative Example 3

[0138] This comparative example is basically the same as Example 1, except that the ethyl acrylate PJ60004-60 in Example 1 is replaced by methyl acrylate PJ60003-60 (containing 40% solvent and 60% methyl acrylate with a Tg of -5°C).

[0139] Comparative Example 4

[0140] This comparative example is basically the same as Example 1, except that the ethyl acrylate PJ60004-60 in Example 1 is replaced by butyl acrylate PJ60085-50 (containing 40% solvent and 60% butyl acrylate with a Tg of -42°C).

[0141] The adhesives in the embodiments and comparative examples were subjected to viscosity test, pot life test and Tg test, and the initial adhesion of the uncured composite insulating paper was evaluated, and the stiffness of the composite insulating paper was tested. The test results are shown in Table 1.

[0142] Viscosity test: Tested in accordance with national standard GB / T 22314-2008.

[0143] Applicable period test: Test according to the national standard GB / T 22314-2008. The time when the viscosity test result reaches 3 times the initial viscosity value is the applicable period.

[0144] Tg test: tested by dynamic mechanical analysis (DMA).

[0145] Initial adhesion assessment: Cut the uncured composite insulating paper into 20mm*200mm strip samples, peel off the samples at the ends, and then perform a peel strength test according to GB / T 2792-2014 "Test method for peel strength of adhesive tapes". The average peel force <4N / 20mm is poor, 4N / 20mm≤average peel force<8N / 20mm is medium, and the average peel force ≥8N / 20mm is good.

[0146] Stiffness test: Cut the composite insulating paper into 10mm*200mm strip samples and conduct the test according to GB / T5591.2-2017. The load is 5000N, the test speed is 25mm / min, 5 samples are tested in each direction, and the median value is taken as the test result.

[0147] Table 1

[0148]

[0149]

[0150] From Table 1 we can see that:

[0151] Compared with Example 1, the amount of accelerator used in Example 10 is increased, the adaptation period of the adhesive is shortened, the initial viscosity of the composite insulating paper is reduced, and during use, foaming and stratification occur in the oil soaking stage (such as Figure 1 As shown). Compared with Example 1, no acrylic resin is added to Comparative Example 1, the Tg of the adhesive is high, the initial viscosity of the composite insulating paper decreases, delamination occurs during use, and the stiffness of the composite insulating paper increases. Compared with Example 1, the amount of epoxy resin used in Comparative Example 2 is increased, the Tg of the adhesive is higher, the stiffness of the composite insulating paper increases, and cracking occurs during use. Compared with Example 1, the Tg of the acrylic resin in Comparative Example 3 is increased, and the stiffness of the composite insulating paper increases. Compared with Example 1, the Tg of the acrylic resin in Comparative Example 4 is reduced, the stiffness of the composite insulating paper is reduced, paper jams occur during use, and poor assembly occurs.

[0152] The above is a detailed introduction to an adhesive and a preparation method thereof, a cross-linked polymer, a composite insulating paper, and an oil-cooled motor provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the ideas of the present application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An adhesive, characterized in that: The invention comprises the following raw materials: acrylic resin, epoxy resin and curing agent, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63): (1-5): (6-15), and the glass transition temperature of the acrylic resin is -30°C to -10°C.

2. The adhesive according to claim 1, characterized in that: The adhesive further comprises an epoxy reactive diluent, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the epoxy reactive diluent is (35-63): (1-5): (6-15): (1-9); and / or The adhesive further comprises an accelerator, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the accelerator is (35-63): (1-5): (6-15): (0.1-0.5); and / or The adhesive also includes a solvent, and the mass ratio of the acrylic resin, the epoxy resin, the curing agent and the solvent is (35-63): (1-5): (6-15): (32-55).

3. The adhesive according to claim 1, characterized in that: The adhesive also includes an epoxy reactive diluent, an accelerator and a solvent. The mass ratio of the acrylic resin, the epoxy resin, the epoxy reactive diluent, the curing agent, the accelerator and the solvent is (42-54): (3-5): (5-6): (9-12): (0.25-0.5): (35.75-41.75).

4. The adhesive according to claim 3, characterized in that: The acrylic resin includes one or more of acrylic acid ester polymers and polyethyl acrylates; and / or The epoxy resin includes one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, phenol epoxy resin and biphenyl epoxy resin; and / or The epoxy reactive diluent includes one or more of C8-C22 glycidyl ether and C8-C22 glycidyl ester; and / or The curing agent includes one or more of tung oil anhydride, dodecenyl anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride; and / or The accelerator includes one or more of a tertiary amine accelerator, an imidazole curing agent and a dicyandiamide accelerator; and / or The solvent includes one or more of xylene, methyl isobutyl ketone, ethylene glycol butyl ether, butyl acetate, cyclohexanone, and ethyl acetate.

5. A method for preparing an adhesive, characterized in that: The following steps are involved: Providing epoxy resin and acrylic resin, performing a first mixing to obtain component A, wherein the acrylic resin has a glass transition temperature of -30°C to -10°C; providing a curing agent to obtain a B component; After the A component and the B component are mixed for the second time, an adhesive is obtained, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63): (1-5): (6-15).

6. The method for preparing the adhesive according to claim 5, characterized in that: The component A further comprises an epoxy reactive diluent, and the first mixing comprises: mixing and stirring the epoxy resin and the epoxy reactive diluent for 30 to 60 minutes, and then adding the acrylic resin and continuing to mix and stir for 30 to 60 minutes; and / or The B component further comprises a solvent, and the curing agent is dissolved in the solvent; and / or The B component further comprises a promoter, and the promoter is added in a manner including dropwise addition; and / or The cross-linking reaction temperature of the adhesive is 40 to 80° C., and the cross-linking reaction time of the adhesive is 4 to 8 hours; and / or The second mixing time is 15 to 30 minutes; and / or The second mixing further comprises: vacuum degassing for 4 to 6 minutes or static degassing for 25 to 35 minutes.

7. A cross-linked polymer, characterized in that The adhesive is prepared by hardening the adhesive described in any one of claims 1 to 4 or the adhesive obtained by the preparation method described in claim 5 or 6.

8. The cross-linked polymer according to claim 7, characterized in that The glass transition temperature of the cross-linked polymer is 0°C to 20°C.

9. A composite insulating paper, characterized in that: The composite insulating paper comprises a first fiber paper, a first adhesive layer, a resin film, a second adhesive layer and a second fiber paper which are stacked; The first adhesive layer and / or the second adhesive layer is obtained by hardening the adhesive according to any one of claims 1 to 4 or the adhesive obtained by the preparation method according to claim 5 or 6.

10. The composite insulating paper according to claim 9, characterized in that: The glass transition temperature of the composite insulating paper is 0°C to 20°C; and / or The transverse stiffness of the composite insulating paper is in the range of 60N to 90N; and / or The longitudinal stiffness of the composite insulating paper ranges from 40N to 65N.

11. The composite insulating paper according to claim 9, characterized in that: The first fiber paper comprises one or more of polyaramid fiber paper, polyester fiber paper, polysulfone amide fiber paper, and inorganic fiber paper; and / or The second fiber paper comprises one or more of polyaramid fiber paper, polysulfoneamide fiber paper, and inorganic fiber paper; and / or The resin film is a polyester film, a polyimide film, a polyethylene terephthalate film, a polyethylene naphthalate film, or a polyphenylene sulfide film.

12. An oil-cooled motor, characterized in that: Comprising the composite insulating paper as described in any one of claims 9 to 11.

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