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

Abstract

An adhesive and a preparation method therefor, a cross-linked polymer, composite insulation paper, and an oil-cooled motor. The adhesive comprises the following raw materials: an acrylic resin, an epoxy resin and a curing agent, wherein the mass ratio of the acrylic resin to the epoxy resin to the curing agent is (35-63):(1-5):(6-15), and the glass transition temperature of the acrylic resin is -30ºC to -10ºC. When the adhesive is applied to multi-layer composite insulation paper, the stiffness of the composite insulation paper can be adjusted to a suitable range.

Description

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

[0001] The present application claims priority to the Chinese patent publication with the publication number 202411368535.4, the title of "an adhesive and preparation method, cross-linked polymer, composite insulating paper, oil-cooled motor" filed in the China Patent Office on September 27, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of insulating paper, in particular to an adhesive and preparation method, cross-linked polymer, composite insulating paper and oil-cooled motor. BACKGROUND

[0003] The motor of the traditional new energy vehicle is a water-cooled motor, and the insulating paper used is generally NHN insulating paper (NHN insulating paper is a soft composite material using polyimide film in the middle and NOMEX paper on both sides), and the adhesive used is polyurethane adhesive. NHN insulating paper is relatively economical and practical, and the heat resistance of NHN insulating paper is good, with an insulation heat resistance temperature ≥180℃.

[0004] However, with the development of new energy vehicles, water-cooled motors are gradually replaced by oil-cooled motors, and the polyurethane adhesive in NHN insulating paper has poor oil resistance and is easily swollen in oil, and even dispersed in oil, thereby causing the NHN insulating paper to delaminate. The existing adhesive such as epoxy resin has good oil resistance, but after use, it often has a high stiffness, especially in order to protect the polyimide film in the middle, a relatively thick adhesive layer is needed, thereby making the stiffness larger. A slightly large or small stiffness will affect the installation in the actual application process, which is not conducive to subsequent use. SUMMARY

[0005] Therefore, the present application provides an adhesive and preparation method, cross-linked polymer, composite insulating paper and oil-cooled motor, which aims to adjust the stiffness value of the existing insulating paper to a suitable range (horizontal stiffness 60N-90N, vertical stiffness 40N-65N).

[0006] In order to achieve the above-mentioned purpose, according to the first aspect of the present application, an adhesive is provided, which comprises the following raw materials: acrylic resin, epoxy resin and curing agent, 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℃ to -10℃.

[0007] In some embodiments of the present application, the adhesive further comprises an epoxy reactive diluent, and a 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

[0008] The adhesive further comprises a promoter, and a mass ratio of the acrylic resin, the epoxy resin, the curing agent, and the promoter is (35-63):(1-5):(6-15):(0.1-0.5); and / or

[0009] The adhesive further comprises a solvent, and a mass ratio of the acrylic resin, the epoxy resin, the curing agent, and the solvent is (35-63):(1-5):(6-15):(32-55).

[0010] In some embodiments of the present application, the adhesive further comprises the following raw materials: an epoxy reactive diluent, a curing agent, a promoter, and a solvent.

[0011] In some embodiments of the present application, a mass ratio of the acrylic resin, the epoxy resin, the epoxy reactive diluent, the curing agent, the promoter, and the solvent is (42-54):(3-5):(5-6):(9-12):(0.25-0.5):(35.75-41.75).

[0012] In some embodiments of the present application, the acrylic resin comprises one or more of an acrylate polymer and a polyethyl acrylate.

[0013] In some embodiments of the present application, the epoxy resin comprises one or more of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol aldehyde type epoxy resin, a phenol type epoxy resin, and a biphenyl type epoxy resin; and / or

[0014] The epoxy reactive diluent comprises one or more of a C8-C22 glycidyl ether and a C8-C22 glycidyl ester; and / or

[0015] The curing agent comprises one or more of a tung oil anhydride, a dodecenyl anhydride, a tetrahydrophthalic anhydride, a methyl tetrahydrophthalic anhydride, a methyl hexahydrophthalic anhydride, a phthalic anhydride, a tetrahydrophthalic anhydride, a hexahydrophthalic anhydride, a methyl tetrahydrophthalic anhydride, a methyl hexahydrophthalic anhydride; and / or

[0016] The promoter comprises one or more of a tertiary amine type promoter, an imidazole type curing agent, and a dicyandiamide type promoter; and / or

[0017] The solvent comprises one or more of xylene, methyl isobutyl ketone, ethylene glycol butyl ether, butyl acetate, cyclohexanone, ethyl acetate.

[0018] According to a second aspect of the present application, a method for preparing an adhesive is provided, comprising the following steps:

[0019] providing an epoxy resin and an acrylic resin, and performing a first mixing to obtain a component A, wherein the acrylic resin has a glass transition temperature of -30℃ to -10℃;

[0020] providing a curing agent to obtain a component B;

[0021] performing a second mixing of the component A and the component B to obtain the adhesive, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent is (35-63):(1-5):(6-15).

[0022] In some embodiments of the present application, the component A further comprises an epoxy reactive diluent, and the first mixing comprises: mixing the epoxy resin and the epoxy reactive diluent and stirring for 30-60 minutes, and then adding the acrylic resin and continuing to stir for 30-60 minutes; and / or

[0023] the component B further comprises a solvent, and the curing agent is dissolved in the solvent; and / or

[0024] the component B further comprises an accelerator, and the accelerator is added in a manner of dropwise adding; and / or

[0025] the cross-linking reaction temperature of the adhesive is 40-80℃, and the cross-linking reaction time of the adhesive is 4-8 hours; and / or

[0026] the second mixing is performed for 15-30 minutes; and / or

[0027] after the second mixing, the adhesive is further subjected to vacuum degassing for 4-6 minutes or static degassing for 25-35 minutes.

[0028] According to a third aspect of the present application, a cross-linked polymer is further provided, which is prepared by hardening the adhesive or the adhesive prepared by the method described above.

[0029] In some embodiments of the present application, the cross-linked polymer has a glass transition temperature of 0℃ to 20℃.

[0030] According to a fourth aspect of the present application, a composite insulating paper is further provided, which comprises a first fiber paper, a first adhesive layer, a resin film, a second adhesive layer and a second fiber paper which are arranged in a stack.

[0031] The first adhesive layer and / or the second adhesive layer are prepared by the adhesive or the cross-linked polymer or the method described above.

[0032] In some embodiments of the present application, the composite insulation paper further comprises a first fiber paper, a resin film and a second fiber paper which are arranged in layers, the adhesive is arranged between the first fiber paper and the resin film, and between the second fiber paper and the resin film.

[0033] In some embodiments of the present application, the glass transition temperature of the composite insulation paper is 0-20℃; and / or

[0034] The transverse stiffness of the composite insulation paper ranges from 60N to 90N; and / or

[0035] The longitudinal stiffness of the composite insulation paper ranges from 40N to 65N.

[0036] In some embodiments of the present application, the first fiber paper comprises one or more of polyaramid fiber paper, polyester fiber paper, polysulfone fiber paper, and inorganic fiber paper; and / or

[0037] The second fiber paper comprises one or more of polyaramid fiber paper, polysulfone fiber paper, and inorganic fiber paper; and / or

[0038] The resin film is a polyester film, a polyimide film, a polyethylene terephthalate film, a polyethylene naphthalate film, and a polyphenylene sulfide film.

[0039] According to a fifth aspect of the present application, an oil-cooled motor is also provided, which comprises the composite insulation paper described above or the composite insulation paper prepared by the preparation method described above.

[0040] In the present application, by controlling the proportion of acrylic resin and epoxy resin with a glass transition temperature Tg of-30℃ to-10℃ in the adhesive, the glass transition temperature Tg of the cross-linked polymer obtained after hardening of the adhesive can be 0-20℃, and further, when the adhesive is applied to a multi-layer composite insulation paper, the glass transition temperature Tg of the multi-layer composite insulation paper can be 0-20℃, so that the stiffness of the composite insulation paper can be adjusted to a suitable range (transverse stiffness of 60N-90N, longitudinal stiffness of 40N-65N).

[0041] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0043] Figure 1 is a blistering delamination diagram of the composite insulation paper provided by Example 10 of the present application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. In addition, it should be understood that the specific implementation described herein is only for the purpose of illustration and explanation of the present application, and is not intended to limit the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing the specific embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] In the present application, the orientation words such as "upper" and "lower" refer to the upper and lower positions of the device in the actual use or working state, and specifically refer to the directions of the drawing surface in the drawings; and "inner" and "outer" refer to the outline of the device. In addition, in the description of the present application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are only used as labels and do not impose numerical requirements or establish sequences.

[0047] In the present application, "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which means that A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural.

[0048] In the present application, "at least one" means one or more, and "multiple" means two or more. "One or more", "at least one of the following", or similar expressions, means any combination of these items, including any combination of single item or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can mean a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, wherein a, b, and c can be single or multiple.

[0049] Various embodiments of the present application can exist in a range of forms; it should be understood that the description in a range form is merely for the convenience and brevity, and should not be understood as a hard limitation on the scope of the present application; therefore, it should be considered that the range described has been specifically disclosed all possible sub-ranges and single values within the range. For example, it should be considered that the range description from 1 to 6 has been 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, regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fraction or integer) within the indicated range.

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

[0051] In the present application, by controlling the proportion of the acrylic resin and the epoxy resin with a glass transition temperature Tg of -30℃ to -10℃ in the adhesive, the glass transition temperature Tg of the cross-linked polymer obtained after the hardening of the adhesive can be 0℃ to 20℃, and further, when the adhesive is applied to a multi-layer composite insulation paper, the glass transition temperature Tg of the multi-layer composite insulation paper can be 0℃ to 20℃, so as to adjust the stiffness of the composite insulation paper to a suitable range (the transverse stiffness being 60N to 90N, and the longitudinal stiffness being 40N to 65N). Meanwhile, when the adhesive is applied to the multi-layer composite insulation paper, the epoxy resin has good oil resistance, and does not swell or peel during the oil immersion process, the acrylic resin can improve the toughness of the adhesive, and can delay the brittleness of the adhesive during long-term oil immersion, thereby improving the service life of the composite paper. The curing agent can cross-link with the acrylic resin and the epoxy resin, and by controlling the mass ratio of the acrylic resin, the epoxy resin, and the curing agent, the cross-linking degree of the acrylic resin and the epoxy resin can be 0.8 to 1.2, and further, the heat resistance and oil resistance of the adhesive can be effectively improved.

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

[0053] In some embodiments, the glass transition temperature of the acrylic resin can be -25℃ to -15℃.

[0054] In some embodiments, the glass transition temperature of the acrylic resin can be -21℃ to -18℃.

[0055] In some embodiments, 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 can be (35-63):(1-5):(6-15):(1-9). In this way, the epoxy reactive diluent can adjust the viscosity of the adhesive, improve the toughness of the cross-linked polymer, and thus adjust the stiffness of the composite insulation paper to a suitable range (60-90 N in the transverse direction and 40-65 N in the longitudinal direction).

[0056] In some embodiments, the mass ratio of the acrylic resin, the epoxy resin, the curing agent, and the accelerator can be (35-63):(1-5):(6-15):(0.1-0.5). In this way, the accelerator can reduce the temperature of the cross-linking reaction and improve 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 can be (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 line production.

[0058] In some embodiments, the adhesive further comprises the following raw materials: an epoxy reactive diluent, a curing agent, an accelerator, and a 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 can be (42-54):(3-5):(5-6):(9-12):(0.25-0.5):(35.75-41.75).

[0060] In some embodiments, the acrylic resin can include one or more of an acrylate polymer and a polyethyl acrylate.

[0061] In some embodiments, the epoxy reactive diluent can include one or more of a C8-C22 glycidyl ether and a C8-C22 glycidyl ester. Such an epoxy reactive diluent has a better improvement on the flexibility of the epoxy resin. The C8-C22 glycidyl ether refers to a glycidyl ether containing 8-22 carbon atoms, such as 1,4-butanediol diglycidyl ether, glycerol triglycidyl ether, ethylene glycol diglycidyl ether, etc., and the C8-C22 glycidyl ester refers to a glycidyl ester containing 8-22 carbon atoms, such as phthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, adipic acid diglycidyl ester, etc.

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

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

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

[0065] In the present application, the epoxy resin and the acrylic ester resin are compounded with anhydride for curing, and the obtained product adhesive has high cross-linking degree, large molecular chain steric hindrance, and good oil resistance; the adhesive has good infiltration and strong cohesion with the substrate, thereby improving the bonding effectiveness of the insulation paper.

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

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

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

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

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

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

[0072] According to a third aspect of the present disclosure, the embodiments of the present application provide a preparation method of an adhesive, comprising the following steps:

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

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

[0075] S13, after the second mixing of the A component and the B component, obtaining the adhesive, wherein the mass ratio of the acrylic resin, the epoxy resin and the curing agent can be (35-63):(1-5):(6-15).

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

[0077] In step S1,

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

[0079] In the present application, the epoxy resin has a large viscosity, and mixing it with the epoxy active diluent can reduce its viscosity and facilitate better mixing and uniformity.

[0080] In step S2,

[0081] In some embodiments, the B component can further comprise an accelerator. The accelerator can be added in the form of dropwise addition. In this way, the large amount of heat generated during the mixing of the curing agent and the accelerator can be prevented from causing explosive polymerization.

[0082] In some embodiments, the crosslinking reaction temperature of the adhesive can be 40-80℃, for example, it can be 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, etc. The crosslinking reaction time of the adhesive can be 4-8h, for example, it can be 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 accelerated to release, thereby facilitating packaging and transportation.

[0083] In step S3,

[0084] In some embodiments, the second mixing time is 15-30 min, for example, it can be 18 min, 20 min, 22 min, 25 min, 28 min, etc.

[0085] In some embodiments, after the second mixing, it can further comprise: vacuum degassing for 4-6 min or static degassing for 25-35 min. In this way, the air bubbles generated during the mixing and stirring process can be eliminated, thereby facilitating the production and coating of the adhesive.

[0086] The cross-linked polymer is prepared by using the adhesive.

[0087] The cross-linked polymer of the present application is applied to the multi-layer composite insulation paper, and the glass transition temperature Tg of the multi-layer composite insulation paper is 0-20℃, so that the stiffness of the composite insulation paper is adjusted to a proper range (the transverse stiffness is 60-90N, and the longitudinal stiffness is 40-65N).

[0088] In some embodiments, the glass transition temperature of the cross-linked polymer can be 0-20℃.

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

[0090] The present application also provides a composite insulation paper, which can include 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 prepared by hardening the adhesive.

[0092] In the present application, by using the adhesive to bond, the glass transition temperature of the composite insulation paper can be 0-20℃, so that the stiffness of the composite insulation paper is adjusted to a proper range, and the transverse stiffness is 60-90N, and the longitudinal stiffness is 40-65N.

[0093] In some embodiments, the composite insulation paper can also include a first fiber paper, a resin film and a second fiber paper which are stacked, the adhesive is arranged between the first fiber paper and the resin film, and the adhesive is arranged 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 erosion, and the resin film can provide good mechanical and electrical properties.

[0095] In some embodiments, the first fiber paper can include one or more of polyaramid fiber paper, polyester fiber paper, polysulfone fiber paper and inorganic fiber paper. In this way, the fiber paper has good high temperature resistance and oil resistance.

[0096] In some embodiments, the second fiber paper can include one or more of polyaramid fiber paper, polysulfone fiber paper and inorganic fiber paper. In this way, the fiber paper has good high temperature resistance and oil resistance.

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

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

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

[0100] According to a fourth aspect of the present disclosure, the embodiments of the present application also provide a preparation method of a composite insulating paper, comprising the following steps:

[0101] The cross-linked polymer, the resin film, the first fiber paper, and the second fiber paper are provided, the cross-linked polymer is arranged on one side surface of the first fiber paper and one side surface of the second fiber paper respectively, the solvent is removed, and then the resin film is laminated, rolled, cured, and solidified, 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 the composite insulating paper.

[0102] In some embodiments, the method for removing the solvent is baking, and the baking temperature can be set in a gradient between 90-120°C, for example, dried by seven baking ovens, and the drying temperatures are 90°C, 100°C, 110°C, 120°C, 110°C, 100°C, and 90°C respectively. The baking time can be 2-4 min. In this way, the solvent can be better removed in a short time, the initial adhesion of the adhesive is improved, and thus the lamination is facilitated.

[0103] In some embodiments, the lamination pressure can be 50-70 N.

[0104] The embodiments of the present application also provide an oil-cooled motor, which comprises the composite insulating paper described above.

[0105] The present application will be specifically described below through specific embodiments. The following embodiments are only part of the embodiments of the present application, and are not a limitation on the present application. The raw materials used in the following embodiments are all commercially available products unless otherwise specified.

[0106] Example 1

[0107] A preparation method of an adhesive, comprising the following steps:

[0108] (1) 5 parts of 1,4-butanediol diglycidyl ether were added into 5 parts of bisphenol A type epoxy resin, mixed and stirred for 30 min, then 80 parts of ethyl acrylate PJ60004-60 (containing 40% of solvent, and 60% of ethyl acrylate with Tg of -19℃) containing solvent were added and stirred for 60 min to obtain component A;

[0109] (2) 9 parts of methyl tetrahydrophthalic anhydride were added into 5.75 parts of ethyl acetate, then 0.25 parts of 2,4,6-tris(dimethylaminomethyl) phenol were added dropwise, and stirred at 60℃ for 6 h to obtain component B;

[0110] (3) Component A and component B were mixed and stirred for 15-30 min, then vacuum defoaming was performed for 5 min to obtain the adhesive.

[0111] A preparation method of a composite insulation paper, comprising the following steps:

[0112] (1) The adhesive was coated on the surface of one side of the first polyaramid fiber paper (aramid 1313) and the surface of one side of the second polyaramid fiber paper (aramid 1313) respectively by using a coating compounder, and then dried for 3 min by passing through seven ovens with drying temperatures of 90℃, 100℃, 110℃, 120℃, 110℃, 100℃ and 90℃ respectively;

[0113] (2) The dried first polyaramid fiber paper (aramid 1313) was combined with the polyethylene naphthalate film with the adhesive between them, and then rolled and aged to obtain roll 1;

[0114] (3) The dried second polyaramid fiber paper (aramid 1313) was combined with roll 1 with the adhesive on the second polyaramid fiber paper (aramid 1313) between them, and then rolled, and then cured at 100℃ for 2 h and at 150℃ for 2 h to obtain the composite insulation paper.

[0115] Example 2

[0116] The example is basically the same as example 1, except that the amount of ethyl acetate in the example is 5.5 parts by weight, and the amount of 2,4,6-tris(dimethylaminomethyl) phenol is 0.5 parts by weight.

[0117] Example 3

[0118] The example is basically the same as example 1, except that the amount of bisphenol A type epoxy resin in the example is 4 parts by weight, the amount of 1,4-butanediol diglycidyl ether is 6 parts by weight, the amount of ethyl acrylate is 70 parts by weight, the amount of ethyl acetate is 7.75 parts by weight, and the amount of methyl tetrahydrophthalic anhydride is 12 parts by weight.

[0119] Example 4

[0120] This example is basically the same as Example 1, except that the amount of the bisphenol A type epoxy resin in this example is 3 parts by weight, the amount of the ethyl acrylate is 90 parts by weight, and the amount of the methyl tetrahydrophthalic anhydride is 10 parts by weight.

[0121] Example 5

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

[0123] Example 6

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

[0125] Example 7

[0126] This example is basically the same as Example 1, except that the bisphenol A type epoxy resin in Example 1 is replaced by the phenol novolak type epoxy resin.

[0127] Example 8

[0128] This example is basically the same as Example 1, except that the bisphenol A type epoxy resin in Example 1 is replaced by the diphenyl type epoxy resin.

[0129] Example 9

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

[0131] Example 10

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

[0133] Comparative Example 1

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

[0135] Comparative Example 2

[0136] The comparative example is basically the same as example 1, the only difference is that the amount of bisphenol A type epoxy resin in the comparative example is 7 parts by weight.

[0137] Comparative example 3

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

[0139] Comparative example 4

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

[0141] The adhesives in the examples and comparative examples were tested for viscosity, pot life, Tg, and the initial adhesion of the composite insulation paper that had not been cured was evaluated, and the stiffness of the composite insulation paper was tested. The test results are shown in Table 1.

[0142] Viscosity test: tested according to national standard GB / T 22314-2008.

[0143] Pot life test: tested according to national standard GB / T 22314-2008, when the viscosity test result reaches 3 times the initial viscosity value, it is the pot life.

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

[0145] Initial adhesion evaluation: the composite insulation paper that had not been cured was cut into 20mm*200mm strip-shaped samples, the samples were peeled at the end, and then the peel strength test was carried out according to GB / T 2792-2014 "Test method for adhesive tape peel strength", the average peel force <4N / 20mm is poor, 4N / 20mm≤average peel force<8N / 20mm is medium, and average peel force≥8N / 20mm is good.

[0146] Stiffness test: the composite insulation paper was cut into 10mm*200mm strip-shaped samples, tested according to GB / T5591.2-2017, the load was selected as 5000N, the test speed was 25mm / min, 5 samples were tested in each direction, and the median value was taken as the test result.

[0147] Table 1

[0148] From Table 1, it can be seen that:

[0149] Compared with Example 1, the accelerator amount of Example 10 is increased, the adhesive adaptation period is shortened, the initial adhesion of the composite insulation paper is decreased, and during use, the foaming and delamination occur in the oil foaming stage (as shown in FIG. 1). Compared with Example 1, Comparative Example 1 does not add the acrylic resin, the Tg of the adhesive is high, the initial adhesion of the composite insulation paper is decreased, and delamination occurs during use, and the stiffness of the composite insulation paper is increased. Compared with Example 1, the amount of epoxy resin of Comparative Example 2 is increased, the Tg of the adhesive is relatively high, the stiffness of the composite insulation paper is increased, and cracking occurs during use. Compared with Example 1, the Tg of the acrylic resin of Comparative Example 3 is increased, and the stiffness of the composite insulation paper is increased. Compared with Example 1, the Tg of the acrylic resin of Comparative Example 4 is decreased, the stiffness of the composite insulation paper is decreased, and during use, the paper jam phenomenon occurs, and the assembly is poor.

[0150] The above provides a kind of adhesive and its preparation method, crosslinking polymer, composite insulation paper, oil-cooled motor provided by the embodiment of the application, the principle and implementation mode of the application are described in this paper by applying specific examples, the above embodiment is only used to help understand the method of the application and its core idea;Meanwhile, for those skilled in the art, according to the idea of the application, there will be changes in specific implementation mode and application range, and the content of the specification should not be understood as the limitation of the application.

Claims

1. A glue comprising the following raw materials: an acrylic resin, an epoxy resin, and a curing agent, wherein a mass ratio of the acrylic resin, the epoxy resin, and the curing agent is (35-63) : (1-5) : (6-15), and a glass transition temperature of the acrylic resin is -30℃ to -10℃.

2. The adhesive according to claim 1, wherein, The glue further comprises an epoxy reactive diluent, and a 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 glue further comprises a promoter, and a mass ratio of the acrylic resin, the epoxy resin, the curing agent, and the promoter is (35-63) : (1-5) : (6-15) : (0.1-0.5) ; and / or The glue further comprises a solvent, and a 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 of claim 1, wherein, The glue further comprises an epoxy reactive diluent, a promoter, and a solvent, and a mass ratio of the acrylic resin, the epoxy resin, the epoxy reactive diluent, the curing agent, the promoter, and the solvent is (42-54) : (3-5) : (5-6) : (9-12) : (0.25-0.5) : (35.75-41.75). 4.The glue according to any one of claims 1 to 3, wherein The acrylic resin comprises one or more of an acrylate polymer and a polyethyl acrylate; and / or The epoxy resin comprises one or more of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol aldehyde type epoxy resin, a phenol type epoxy resin, and a biphenyl type epoxy resin; and / or The epoxy reactive diluent comprises one or more of a C8-C22 glycidyl ether and a C8-C22 glycidyl ester; and / or The curing agent comprises one or more of a tung oil anhydride, a dodecenyl anhydride, a tetrahydrophthalic anhydride, a methyl tetrahydrophthalic anhydride, a methyl hexahydrophthalic anhydride, a phthalic anhydride, a tetrahydrophthalic anhydride, a hexahydrophthalic anhydride, a methyl tetrahydrophthalic anhydride, and a methyl hexahydrophthalic anhydride; and / or The promoter comprises one or more of a tertiary amine type promoter, an imidazole type curing agent, and a dicyandiamide type promoter; and / or The solvent comprises one or more of xylene, methyl isobutyl ketone, ethylene glycol butyl ether, butyl acetate, cyclohexanone, and ethyl acetate. 5.A method for preparing a glue, comprising the following steps: providing an epoxy resin and an acrylic resin, and performing a first mixing to obtain a component A, wherein a glass transition temperature of the acrylic resin is -30℃ to -10℃; providing a curing agent to obtain a component B; performing a second mixing of the component A and the component B to obtain the glue, wherein a 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, wherein, The A component further comprises an epoxy reactive diluent, the first mixing comprises: mixing the epoxy resin and the epoxy reactive diluent for 30-60 minutes, then adding the acrylic resin and continuing mixing for 30-60 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 an accelerator, and the accelerator is added by dropwise adding; and / or The cross-linking reaction temperature of the adhesive is 40-80℃, and the cross-linking reaction time of the adhesive is 4-8 hours; and / or The second mixing time is 15-30 minutes; and / or The second mixing further comprises vacuum degassing for 4-6 minutes or static degassing for 25-35 minutes.

7. A cross-linked polymer prepared by hardening the adhesive of any one of claims 1-4 or the adhesive prepared by the method of claim 5 or 6.

8. The crosslinked polymer of claim 7, wherein, The glass transition temperature of the cross-linked polymer is 0-20℃.

9. A composite insulation paper, comprising a first fiber paper, a first adhesive layer, a resin film, a second adhesive layer and a second fiber paper which are arranged in layers; The first adhesive layer and / or the second adhesive layer are obtained by hardening the adhesive of any one of claims 1-4 or the adhesive prepared by the method of claim 5 or 6.

10. The composite insulation paper of claim 9, wherein, The glass transition temperature of the composite insulation paper is 0-20℃; and / or The transverse stiffness of the composite insulation paper ranges from 60N to 90N; and / or The longitudinal stiffness of the composite insulation paper ranges from 40N to 65N.

11. The composite insulation paper according to claim 9 or 10, wherein, The first fiber paper comprises one or more of polyaramid fiber paper, polyester fiber paper, polysulfone fiber paper and inorganic fiber paper; and / or The second fiber paper comprises one or more of polyaramid fiber paper, polysulfone fiber paper and inorganic fiber paper; and / or The resin film is one or more of polyester film, polyimide film, polyethylene terephthalate film, polyethylene naphthalate film and polyphenylene sulfide film.

12. An oil-cooled motor comprising the composite insulation paper of any one of claims 9-11.

Images