CN110746919A

CN110746919A - Preparation method of pouring sealant for lightweight locomotive electrical equipment

Info

Publication number: CN110746919A
Application number: CN201911074782.2A
Authority: CN
Inventors: 顾志伟; 蒋寅; 庄雪峰; 刘军; 周训虎
Original assignee: Yixing City Pulitai Electronic Materials Co Ltd
Current assignee: Pulitai Electronic Materials Jiangsu Co ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-02-04
Anticipated expiration: 2039-11-06
Also published as: CN110746919B

Abstract

The pouring sealant mainly uses epoxy resin, filler and other reagents, and the pouring sealant for the lightweight locomotive electrical equipment with excellent performance is prepared. Experimental test results show that the pouring sealant prepared by the preparation method still has excellent cracking resistance at-40 ℃ and 120 ℃, and also has excellent flame retardant property, high heat conductivity, higher impact strength and bending strength. In addition, the pouring sealant prepared by using the polyurethane prepolymer, the light filler such as the calomel (fumed silica), the pretreated micro silicon powder and the micro beads, the high-toughness and low-density reinforced fibers and the high-hydroxyl value polyol also has excellent electrical performance, excellent vibration fatigue resistance and lower density, can meet the use requirements of different types of locomotive electrical equipment, and has strong industrial application value and development prospect.

Description

Preparation method of pouring sealant for lightweight locomotive electrical equipment

Technical Field

The invention relates to the field of adhesives, in particular to a preparation method of a pouring sealant for lightweight locomotive electrical equipment.

Background

In the manufacturing process of locomotive electrical equipment such as automobiles, pouring sealant is an indispensable chemical adhesive. The device in the locomotive electrical equipment is sealed and protected by the pouring sealant, so that the damage of external harmful substances to the device can be reduced, the external force damage can be prevented, and the service life of the device is prolonged. With the continuous development and updating of the field of locomotives, different types of locomotive electrical equipment also provide new requirements for pouring sealant.

At present, the improvement of the performance of the potting adhesive mainly focuses on three aspects of increasing toughness, improving heat resistance and improving operating performance. However, for locomotive electrical equipment, the used pouring sealant is far from insufficient in improving the toughness and heat resistance and the operation performance, the electrical performance of the pouring sealant is still insufficient when the pouring sealant is used, and the electrical performance is obviously poor after the pouring sealant is used for a long time; or the vibration fatigue resistance and the cracking resistance of the pouring sealant are not enough, and after the pouring sealant is used for a period of time, devices can be loosened, and even safety accidents can happen. Meanwhile, the pouring sealant for the electrical equipment of the automobile and the locomotive in the prior art can increase the dead weight of the automobile to a certain extent, increase the energy consumption of the automobile and be not in line with the requirement of environmental protection. Therefore, there is a need to develop a pouring sealant for lightweight locomotive electrical equipment, which has excellent cracking resistance, excellent flame retardancy, high thermal conductivity, high impact strength and bending strength, excellent electrical properties, excellent vibration fatigue resistance, and low density.

Disclosure of Invention

In order to solve the technical problem, a first aspect of the present invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, including the following steps:

step one, preparation of a component A: according to parts by weight, under the stirring condition, sequentially adding 80-90 parts of epoxy resin, 5-15 parts of diluent, 0.1-0.3 part of defoaming agent, 3-5 parts of toughening agent, 15-40 parts of filler and 3-8 parts of auxiliary agent, and stirring and mixing uniformly to obtain a component A;

step two, preparation of the component B: sequentially adding 50-90 parts by weight of curing agent and 2-15 parts by weight of accelerator under stirring, and uniformly stirring and mixing to obtain a component B;

step three, preparing pouring sealant: and (3) mixing the component A obtained in the step one and the component B obtained in the step two according to the ratio of (2-5): 1, uniformly mixing and stirring, and performing vacuum defoaming, filling and sealing and curing to obtain the pouring sealant for the lightweight locomotive electrical equipment.

As a preferable technical scheme, the component A also comprises 20-40 parts by weight of polyurethane.

As a preferred technical scheme, the toughening agent is toughening polymer and/or reinforcing fiber.

As a preferable technical scheme, the filler is spherical micro silicon powder and hollow microspheres.

As a preferable technical scheme, the weight ratio of the spherical micro silicon powder to the hollow micro beads is 1: (0.2-0.35).

As a preferable technical scheme, the particle size of the spherical micro silicon powder is 20-35 μm.

As a preferable technical scheme, the particle size of the hollow microsphere is 45-60 mu m.

As a preferred technical scheme, the hollow microspheres are prepolymer-coated hollow microspheres.

As a preferable technical solution, the filler further includes one or more of light powder, aluminum oxide, zinc oxide, aluminum nitride, boron nitride, silicon carbide, montmorillonite, carbon nanotube, graphene, and barite.

The second aspect of the invention provides a pouring sealant for lightweight locomotive electrical equipment.

Has the advantages that: the pouring sealant mainly uses epoxy resin, filler and other reagents, and the pouring sealant for the lightweight locomotive electrical equipment with excellent performance is prepared. Experimental test results show that the pouring sealant prepared by the preparation method still has excellent cracking resistance at-40 ℃ and 120 ℃, and also has excellent flame retardant property, high heat conductivity, higher impact strength and bending strength. In addition, the invention uses polyurethane prepolymer and calomel (gas phase two)Silicon oxide), lightweight fillers such as pretreated micro silicon powder and micro beads, high-toughness and low-density reinforced fibers and high-hydroxyl-value polyol, and the prepared pouring sealant has excellent electrical performance, excellent vibration fatigue resistance and lower density (1 g/cm)³Left and right), can meet the use requirements of different types of locomotive electrical equipment, and has strong industrial application value and development prospect.

Detailed Description

The technical features of the technical solutions provided by the present invention are further clearly and completely described below with reference to the specific embodiments, and the scope of protection is not limited thereto.

The words "preferred", "more preferred", and the like, in the present invention refer to embodiments of the invention that may provide certain benefits, under certain circumstances. However, other embodiments may be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

The invention provides a pouring sealant for lightweight locomotive electrical equipment, which is prepared from the following raw materials in parts by weight:

the component A comprises:

b component

30-50 parts of modified alicyclic amine;

20-40 parts of polyether amine;

2-15 parts of an accelerant;

according to the weight portion, the weight ratio of A: b ═ 2-5): 1, mixing and using.

In a preferred embodiment, the weight ratio in parts by weight in accordance with a: b ═ 3.5: 1, mixing and using.

In a preferred embodiment, the component A further comprises 20-40 parts by weight of polyurethane.

In a more preferred embodiment, the a component further comprises 30 parts by weight of polyurethane.

The second aspect of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which comprises the following steps:

In a preferred embodiment, the preparation method of the pouring sealant for the light-weight locomotive electrical equipment comprises the following steps:

step one, preparation of a component A: according to the parts by weight, 85 parts of epoxy resin, 10 parts of diluent, 0.2 part of defoaming agent, 4 parts of toughening agent, 27.5 parts of filler and 5.5 parts of auxiliary agent are sequentially added under the stirring condition, and after uniform stirring and mixing, the component A is obtained;

step two, preparation of the component B: according to the parts by weight, 70 parts of curing agent and 8.5 parts of accelerator are sequentially added under the stirring condition, and after uniform stirring and mixing, the component B is obtained;

step three, preparing pouring sealant: mixing the component A obtained in the step one and the component B obtained in the step two according to the ratio of 3.5: 1, uniformly mixing and stirring, and performing vacuum defoaming, filling and sealing and curing to obtain the pouring sealant for the lightweight locomotive electrical equipment.

< step one >

In a preferred embodiment, the preparation of the component a in the step one of the present invention is: according to the weight portion, 85 portions of epoxy resin, 10 portions of diluent, 0.2 portion of defoaming agent, 4 portions of toughening agent, 27.5 portions of filler and 5.5 portions of auxiliary agent are added in turn under the stirring condition, and the component A is obtained after even stirring and mixing.

(epoxy resin)

The CAS number of 38891-59-7 is a generic name for a polymer having two or more epoxy groups in its molecule.

The epoxy resin is not particularly limited in the present invention, and may be various epoxy resins known to those skilled in the art, such as bisphenol A type epoxy resin available from Lebang composites, Inc., of Changzhou, model No. Showa R-806.

(polyurethane)

Polyurethane, abbreviated as pu (polyurethane), is a thermoplastic polymer with linear structure.

The polyurethane is not particularly limited in the present invention and may be any of various polyurethanes known to those skilled in the art, such as those available from basf, germany under model number ES80a 15.

(Diluent)

The diluent is an additive which is used by being mixed with basic resin such as epoxy resin and the like, reduces the viscosity of a curing system, increases the fluidity, prolongs the service life, improves the operability and does not influence the basic performance of a cured product.

In a preferred embodiment, the diluent is selected from one or more of alkylene glycidyl ether, butyl glycidyl ether, ethylene glycol diglycidyl ether, phenyl glycidyl ether, polypropylene glycol diglycidyl ether, C12-14 fatty glycidyl ether, o-tolyl glycidyl ether, and neopentyl glycol diglycidyl ether.

In a more preferred embodiment, the diluent is ethylene glycol diglycidyl ether.

The ethylene glycol diglycidyl ether has CAS number 2224-15-9 and is purchased from Senffida chemical Co., Ltd.

(antifoaming agent)

Defoamers, also known as defoamers, are additives that reduce surface tension, inhibit foam generation, or eliminate foam already generated.

In a preferred embodiment, the defoaming agent is selected from one or more of emulsified silicone oil, higher alcohol fatty acid ester complex, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene amine ether, polyoxypropylene glycerol ether, polyoxypropylene polyoxyethylene glycerol ether and polydimethylsiloxane.

In a more preferred embodiment, the defoamer is polydimethylsiloxane.

The polydimethylsiloxane, CAS number 9006-65-9, was purchased from Nantong Runfeng petrochemical Co., Ltd.

(flexibilizers)

The toughening agent is a reagent capable of increasing the flexibility of the material and improving the impact resistance of the material.

In a preferred embodiment, the toughening agent is a toughening polymer and/or a reinforcing fiber.

Examples of toughening polymers include, but are not limited to, carboxyl terminated nitrile rubber, polyether, polysulfide rubber.

Examples of reinforcing fibers include, but are not limited to, whisker materials, glass fibers, aramid fibers, polyethylene fibers, poly-p-phenylene benzobisoxazole fibers, boron fibers.

In a more preferred embodiment, the toughening agent is a reinforcing fiber.

Reinforcing fiber

A reinforcing fiber is a fibrous reinforcing material used as a structural material.

In a preferred embodiment, the reinforcing fibers are glass fibers.

The present invention is not particularly limited to the manufacturers of the glass fibers, such as EXPA D15 from KUREBATO KEMEKO INDUSTRT CO. of Nanjing, DuPont PA66, New Material Ltd.

(Filler)

The filler, also called filler, is a solid material filled in other objects to improve the processing performance, the mechanical property of products and reduce the cost.

In a preferred embodiment, the filler is spherical silica fume and cenospheres.

Silica fume

The micro-silica fume, also known as silica fume or condensed silica fume, is a large amount of highly volatile SiO produced in the ore-smelting electric furnace when ferroalloy is used for smelting ferrosilicon and industrial silicon₂And Si gas, which is quickly oxidized with air after being discharged, condensed and precipitated to form substances.

Hollow micro-bead

The hollow microsphere is a grey white loose powder material with good fluidity.

In a preferred embodiment, the weight ratio of the spherical micro silicon powder to the hollow microspheres is 1: (0.2-0.35).

In a more preferred embodiment, the weight ratio of the spherical micro silicon powder to the hollow micro beads is 1: 0.275.

in a preferred embodiment, the particle size of the spherical silica fume is 20 to 35 μm.

In a more preferred embodiment, the spherical microsilica has a particle size of 25 μm.

The spherical micro silicon powder is purchased from Beijing Zhonghuayuan science and technology Co., Ltd, and has the model of HS-304.

In a preferred embodiment, the particle size of the cenospheres is 45 to 60 μm.

In a more preferred embodiment, the cenospheres have a particle size of 50 μm.

The hollow microspheres are hollow glass microspheres, purchased from Shanxi Hainuo science and technology Co., Ltd, and have the model of HN40D 50.

In the research and development process of the applicant of the invention, the flexibility and the vibration resistance of the pouring sealant are improved by adopting the reinforced fibers and utilizing the high toughness and the low density of the reinforced fibers; and the vibration fatigue resistance of the pouring sealant is improved by utilizing the elastic structure of the hard section and the soft section of the polyurethane pouring sealant. But all the performances of the obtained pouring sealant still cannot meet the use requirements of the pouring sealant for lightweight locomotive electrical equipment.

In order to reduce the density of the pouring sealant and avoid the obtained pouring sealant from increasing the weight of the locomotive electrical equipment, the applicant adds part of spherical micro-silicon powder raw materials into the preparation raw materials of the pouring sealant, and finds that the prepared pouring sealant is lighter in relative weight. In the process of completing the invention, the applicant finds that when the filler simultaneously comprises the spherical micro silicon powder and the hollow microspheres, the weight ratio of the spherical micro silicon powder to the hollow microspheres is 1: (0.2-0.35), when the particle size of the spherical micro silicon powder is 20-35 μm and the particle size of the hollow microspheres is 45-60 μm, the impact strength of the pouring sealant is obviously improved. The applicant believes that the hollow microspheres are added into the pouring sealant in a certain amount, and after the pouring sealant is cured and formed, the hollow microspheres can quickly absorb energy transmitted from the outside when being stimulated by the outside, and most of the energy is consumed by media such as air blocked in the hollow microspheres, so that the outside energy is prevented from continuously damaging the inside of the pouring sealant, and the hollow impact strength of the pouring sealant is improved. However, the applicant has found that the content of the hollow microspheres used therein cannot be too high, which may not only improve the impact resistance of the potting adhesive, but also significantly reduce the thermal conductivity of the potting adhesive, thereby affecting the service life thereof. In addition, the particle size and morphology of the spherical silica fume and the hollow microspheres also have significant influence on impact resistance, cracking resistance, thermal conductivity and the like. When the particle sizes of the spherical micro silicon powder and the hollow micro beads are basically consistent, the impact resistance of the prepared pouring sealant is not remarkably improved, and the thermal conductivity of the pouring sealant is remarkably reduced.

In a preferred embodiment, the cenosphere is a prepolymer-coated cenosphere.

In a preferred embodiment, the prepolymer is selected from one or more of phenolic prepolymer, urea formaldehyde prepolymer, polyurethane prepolymer and polyether glycol prepolymer.

In a more preferred embodiment, the prepolymer is a polyurethane prepolymer, that is, the cenosphere is a cenosphere coated with a polyurethane prepolymer.

In a preferred embodiment, the preparation method of the hollow microsphere coated by the polyurethane prepolymer comprises the following steps:

①, adding 6-10 parts by weight of isocyanate into 12-16 parts by weight of polyol under the stirring condition, and stirring for 2-3 hours at 80-90 ℃ to obtain a mixture;

②, adding 8-12 parts by weight of dried cenospheres into an acetone solution containing 1-2 parts by weight of coupling agent, heating to 70-90 ℃, stirring for 1.5-2.5 hours, and drying at 100-110 ℃ for 10-12 hours to obtain treated cenospheres;

and ③, adding the processed hollow microspheres obtained in the step ② into the mixture obtained in the step ①, and stirring at 40-60 ℃ for 0.75-1 h to obtain the hollow microspheres coated by the polyurethane prepolymer.

In a more preferred embodiment, the preparation method of the hollow microsphere coated by the polyurethane prepolymer comprises the following steps:

①, adding 8 parts by weight of isocyanate into 14 parts by weight of polyol under the stirring condition, and stirring at 85 ℃ for 2.5 hours to obtain a mixture;

②, adding 10 parts by weight of dried cenospheres into an acetone solution containing 1.5 parts by weight of coupling agent, heating to 80 ℃, stirring for 2 hours, and drying at 105 ℃ for 11 hours to obtain treated cenospheres;

and ③, adding the processed cenospheres obtained in the step ② into the mixture obtained in the step ①, and stirring for 0.9h at the temperature of 45 ℃ to obtain the cenospheres coated by the polyurethane prepolymer.

The coupling agent is isopropyl trititanate (KR-38S), which is a product of Kenrez company in the United states.

Isocyanates

Isocyanate is a generic name for various esters of isocyanic acid.

In a preferred embodiment, the isocyanate is a mixture of hexamethylene diisocyanate and L-lysine triisocyanate.

In a preferred embodiment, the molar ratio of hexamethylene diisocyanate to L-lysine triisocyanate in the isocyanate is (3-5): 1.

in a more preferred embodiment, the molar ratio of hexamethylene diisocyanate to L-lysine triisocyanate in the isocyanate is 4: 1.

the hexamethylene diisocyanate, CAS number 822-06-0, was purchased from Shanghai Allantin Biotech Co., Ltd.

The L-lysine triisocyanate has a CAS number of 69878-18-8 and is purchased from Hangzhou Brown biological medicine science and technology Co.

Polyhydric alcohols

The polyhydric alcohol is an alcohol having two or more hydroxyl groups in the molecule.

In a preferred embodiment, the polyol is selected from one or more combinations of polyethers, polyester polyols, polycarbonate polyols, acrylic polyols, epoxy polyols, silicon polyols, polyolefin polyols.

In a more preferred embodiment, the polyol is a polyether.

In a further preferred embodiment, the polyether is a high resilience polyether.

In a preferred embodiment, the polyether is a high resilience polyether having a hydroxyl value of 25 to 45 (mgKOH/g).

In a more preferred embodiment, the polyether is a high resilience polyether having a hydroxyl value of 32 to 36 (mgKOH/g).

The hydroxyl value in the present invention means the number of milligrams of potassium hydroxide (KOH) corresponding to the hydroxyl group in 1g of the sample, expressed as mgKOH/g.

The high-resilience polyether with the thickness of 32-36 (mgKOH/g) is purchased from Guangzhou Wenlong chemical industry Co., Ltd and has the model of EP-330N.

In the process of completing the invention, the applicant finds that the vibration fatigue resistance and the cracking resistance of the pouring sealant after the hollow microspheres are coated by the polyurethane prepolymer and cured are obviously improved. The applicant coats the hollow microsphere by the polyurethane prepolymer, coats the high polymer material on the hollow microsphere in a covalent bond mode by utilizing the chemical reaction between the active group on the surface of the hollow microsphere and the isocyanate group on the prepolymer, changes the surface characteristic of the hollow microsphere and enables the hollow microsphere to be better compatible and dispersible with components such as epoxy resin (and polyurethane). Meanwhile, in the curing process of the pouring sealant, excessive isocyanate on the polyurethane prepolymer reacts with hydroxyl and other groups generated on the epoxy resin, so that the hollow microspheres are lapped on two epoxy resin polymer molecular chains to form stress absorption points, and transmitted vibration energy can be repeatedly absorbed when the electronic equipment vibrates in use, thereby avoiding cracking and impact damage generated by rotation.

In addition, the Applicant has found, in carrying out the present invention, that when a molar ratio of 4: when the mixture of hexamethylene diisocyanate and L-lysine triisocyanate of 1 is used as isocyanate and rebound polyether with high hydroxyl value is used as polyol, the performances of cracking resistance, impact strength, bending strength and the like are remarkably improved. Probably because the isocyanate and the rebound polyether with high hydroxyl value can form a polyurethane prepolymer with a multi-branched structure due to the high hydroxyl value content and the ternary structure of the isocyanate in the process of forming the polyurethane prepolymer, the polyurethane prepolymer can be lapped on a plurality of epoxy resin molecular chains after being coated on the surfaces of the hollow microspheres to form a structure similar to a spider net, the elasticity of the pouring sealant after curing is further improved, the pouring sealant is deformed and absorbs energy after being vibrated, and the hollow microspheres recover and deform under the traction action, so that cracking and the like caused by large vibration are avoided.

In a preferred embodiment, the filler further comprises one or more of a combination of calomel, alumina, zinc oxide, aluminum nitride, boron nitride, silicon carbide, montmorillonite, carbon nanotube, graphene, and barite.

In a more preferred embodiment, the filler further comprises one or more combinations of calomel, alumina, zinc oxide, aluminum nitride, boron nitride, and silicon carbide.

In a further preferred embodiment, the filler further comprises 6-9 parts by weight of a mixture of aluminum nitride and silicon carbide and 1-2 parts by weight of calomel.

In a further preferred embodiment, the filler further comprises 7.5 parts by weight of a mixture of aluminum nitride and silicon carbide, 1.5 parts by weight of a calomel.

The light powder, i.e., silica, used in the present invention is not particularly limited and may be various light powders (silica) well known to those skilled in the art, such as fumed silica having a CAS number of 14808-60-7, available from kugon chemical ltd, su, under the model number HDK T40.

In a preferred embodiment, the mixture of aluminum nitride and silicon carbide is a modified mixture of aluminum nitride and silicon carbide.

In a preferred embodiment, the method for preparing the modified mixture of aluminum nitride and silicon carbide comprises the following steps: weighing 14-16 parts by weight of aluminum nitride and silicon carbide, and drying at 110-130 ℃ for 1-1.5 hours to obtain a mixture; adding 10-14 parts of coupling agent, 18-22 parts of absolute ethyl alcohol and 14-16 parts of distilled water into the mixture, and stirring and mixing for 10-20 min at room temperature; and continuously heating to 110-130 ℃, reacting for 45-60 min, filtering and drying to obtain the catalyst.

In a more preferred embodiment, the method for preparing the modified mixture of aluminum nitride and silicon carbide comprises the following steps: weighing 15 parts of aluminum nitride and silicon carbide according to parts by weight, and drying at 120 ℃ for 1h to obtain a mixture; adding 12 parts of coupling agent, 20 parts of absolute ethyl alcohol and 15 parts of distilled water into the mixture, and stirring and mixing for 15min at room temperature; and continuously heating to 120 ℃, reacting for 50min, filtering and drying to obtain the product.

In a preferred embodiment, the weight ratio of the aluminum nitride to the silicon carbide is (1-1.5): 1.

in a more preferred embodiment, the aluminum nitride and silicon carbide weight ratio is 1.2: 1.

in a preferred embodiment, the particle size of the aluminum nitride and silicon carbide is no greater than 10 μm.

In a more preferred embodiment, the particle size of the aluminum nitride and silicon carbide is 2 μm.

The aluminum nitride is not particularly limited in the present invention, and may satisfy the above particle size requirement, and for example, it is available from Clarmar reagent, model number 1227149285.

The silicon carbide is not particularly limited in the present invention, and may satisfy the above-mentioned particle size requirements, and may be purchased from Nanmen emery Mill, Topti, for example, of type W_2.5。

In a preferred embodiment, the coupling agent is isopropyl trititanate (KR-38S).

The applicant finds that although the density of the pouring sealant can be reduced to a great extent and the pouring sealant becomes lighter by adding spherical micro silicon powder, hollow microspheres and other components into the pouring sealant, the introduction of the components can form a loose structure inside the pouring sealant to a certain extent, so that the density is reduced, and the heat transfer is reduced. In order to further improve the thermal conductivity of the pouring sealant, the applicant adds part of inorganic thermal conductive filler into the pouring sealant, and finds that the weight ratio of the modified aluminum nitride to the silicon carbide is 1.2: 1, the heat-conducting property of the pouring sealant is obviously improved when the inorganic heat-conducting filler is mixed. The applicant speculates that the components are modified to improve the dispersibility of epoxy resin (polyurethane) and other high polymer materials in the pouring sealant, so that the components are fully mixed into a pouring sealant system to avoid agglomeration, thereby effectively improving the heat transfer of the pouring sealant and improving the heat conductivity.

The applicant unexpectedly discovers in the process of completing the invention that when spherical micro silicon powder, hollow microspheres and modified aluminum nitride and silicon carbide components are selected as fillers in the preparation raw materials of the pouring sealant, the thermal conductivity of the prepared pouring sealant is remarkably improved. The applicant speculates that the possible reason is that large gaps are generated between the spherical micro silicon powder and the hollow micro beads with large particle sizes in the process of mixing and curing with high polymer raw materials such as epoxy resin (and polyurethane), and components such as aluminum nitride and silicon carbide with small particle sizes can enter the gaps in the process of stirring and curing, so that the gaps can be filled, and the defects generated in the pouring sealant can be compensated. Meanwhile, the defects such as the gap and the like greatly obstruct the heat transfer, so that the heat conductivity of the product is correspondingly improved after the defects are compensated.

Meanwhile, in the process of completing the invention, the applicant finds that when the polyurethane prepolymer is used as the raw material for preparing the pouring sealant to coat the hollow microspheres, the modified aluminum nitride and the silicon carbide, the heat conductivity, the cracking resistance, the hollow impact resistance and the like of the prepared pouring sealant are improved, and the flame retardant property of the pouring sealant is also obviously improved. The applicant speculates that the hollow structure of the hollow microspheres in the pouring sealant can reduce the heat transfer and play a certain role in heat insulation, and dioctyl pyrophosphoric acid acyloxy contained in an isopropyl trititanate structure adopted in the modified aluminum nitride and silicon carbide is decomposed to generate polymetaphosphoric acid when heated, so that the surface of a high polymer material is rapidly dehydrated and carbonized to form a carbonized layer, and the simple substance carbon does not generate evaporation combustion and decomposition combustion of flame, thereby being beneficial to improving the flame retardance of the pouring sealant. And the isopropyl trititanate is decomposed by heating, and a nonvolatile glass substance is formed on the surface of the pouring sealant, and the compact protective layer can help to isolate heat and avoid further combustion. Therefore, under the synergistic action among the hollow microspheres, the spherical micro silicon powder, the modified aluminum nitride, the silicon carbide and the like, the pouring sealant is prevented from burning in multiple aspects, and the synergistic flame retardant effect is achieved.

(auxiliary agent)

In the invention, the auxiliary agents include but are not limited to anti-settling agents, coupling agents, color pastes, flame retardants and the like.

< step two >

In a preferred embodiment, the preparation of the second step and the component B of the invention is as follows: and (3) sequentially adding 70 parts of curing agent and 8.5 parts of accelerator by weight under the stirring condition, and uniformly stirring and mixing to obtain the component B.

(curing agent)

The curing agent is an additive which reacts with high molecular resin to form a net-shaped stereo polymer, and the composite material aggregate is enveloped in the net-shaped body to change the linear resin into a tough body-shaped solid.

In a preferred embodiment, the curing agent is selected from one or more of aliphatic amine, polyether amine, alicyclic amine, polyamide, polyacid amine and aromatic amine.

In a more preferred embodiment, the curing agents are polyetheramines and alicyclic amines.

Polyether amine

Polyether amine, abbreviated as PEA (amino-terminated polyoxypropylene) in English, has CAS number of 9046-10-0, and is a polymer with a main chain of a polyether structure and an end active functional group of amino.

The polyetheramine of the present invention is not particularly limited, and may be any of various polyetheramines known to those skilled in the art, for example, commercially available from Wuxi Ministry of drying technology, Inc. under the model number D230.

The alicyclic amine is not particularly limited in the present invention, and may be any of various alicyclic amines known to those skilled in the art, or may be a modified alicyclic amine, for example, commercially available from Shanghai Raschig chemical technology, Inc. under model number 1016B.

(Accelerator)

The accelerator, when used in combination with the fixative, is a relatively small amount of material that increases the rate of reaction.

The accelerator is not particularly limited in the present invention and may be any of a variety of accelerators known to those skilled in the art, such as 2, 4, 6-tris (dimethylaminomethyl) phenol, available from Lebang composites, Inc., of Changzhou under the model DMP-30 accelerator.

In a more preferred embodiment, the weight ratio of the polyether amine to the alicyclic amine in the curing agent is (0.7-0.8): 1.

in a further preferred embodiment, the weight ratio of polyetheramine to alicyclic amine in the curing agent is 0.75: 1.

< step three >

In a preferred embodiment, the preparation of the potting adhesive comprises the following third step: mixing the component A obtained in the step one and the component B obtained in the step two according to the ratio of 3.5: 1, uniformly mixing and stirring, and performing vacuum defoaming, filling and sealing and curing to obtain the pouring sealant for the lightweight locomotive electrical equipment.

The third aspect of the invention provides an application of the pouring sealant for the lightweight locomotive electrical equipment, which is applied to the field of automobiles or locomotives, but is not limited thereto.

The present invention will now be described in detail by way of examples, and the starting materials used are commercially available unless otherwise specified.

Examples

Example 1

The embodiment 1 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which comprises the following steps:

The epoxy resin is bisphenol A epoxy resin which is purchased from Hezhou Lebang composite material Co., Ltd, and has the model of Showa R-806. The diluent is ethylene glycol diglycidyl ether, has CAS number 2224-15-9, and is purchased from Senffida chemical Co., Ltd. The defoamer is polydimethylsiloxane with the CAS number of 9006-65-9, and purchased from Nantong Runfeng petrochemical Co. The toughening agent is glass fiber. The auxiliary agent is a German Bick BYK-410 anti-settling agent, carbon black and red phosphorus, and the weight ratio of the German Bick BYK-410 anti-settling agent to the carbon black to the red phosphorus is 2: 1: 2.5; the carbon black was purchased from Heizhou Fengsho chemical Co., Ltd; the red phosphorus, Suzhou sea plasticizing Co. The curing agent is polyether amine and alicyclic amine, and the weight ratio of the polyether amine to the alicyclic amine is 0.75: 1; the polyether amine is purchased from Wuxi Ministry drying chemical company, and has the model number of D230; the alicyclic amine was purchased from Shanghai Rixi chemical technology, Inc. with model number 1016B. The accelerator is 2, 4, 6-tris (dimethylaminomethyl) phenol, purchased from Bangzhou Lebang composite Co., Ltd, and has the model number DMP-30.

The filler comprises 7.5 parts by weight of a mixture of modified aluminum nitride and silicon carbide, 1.5 parts by weight of calomel and 20 parts by weight of a mixture of spherical micro silicon powder and hollow microspheres. The calomel is purchased from Kun gang chemical Co., Suzhou, and the model is HDK T40; the weight ratio of the spherical micro silicon powder to the hollow microspheres is 1: 0.275; the particle size of the spherical micro silicon powder is 25 mu m, and the spherical micro silicon powder is purchased from Zhanghuayuan scientific and technology limited company in Beijing and has the model number of HS-304; the preparation method of the hollow glass bead coated by the polyurethane prepolymer comprises the following steps:

Wherein the hollow microspheres are hollow glass microspheres with the particle size of 50 μm, and are purchased from Shanxi Hainuo science and technology Co., Ltd, and the model is HN40D 50; the isocyanate is a mixture of hexamethylene diisocyanate (CAS: 822-06-0) and L-lysine triisocyanate (CAS: 69878-18-8), and the molar ratio of the hexamethylene diisocyanate to the L-lysine triisocyanate is 4: 1. the L-lysine triisocyanate was purchased from Hangzhou Brown biomedical science and technology, Inc. The polyol is high resilience polyether (EP-330N) with a hydroxyl value of 32-36 (mgKOH/g), and is purchased from Guangzhou Wenlong chemical industry Co., Ltd; the coupling agent is KR-38S isopropyl trititanate from Kenzechie, USA.

The preparation method of the mixture modified by the aluminum nitride and the silicon carbide comprises the following steps: weighing 15 parts of aluminum nitride and silicon carbide according to parts by weight, and drying at 120 ℃ for 1h to obtain a mixture; adding 12 parts of coupling agent, 20 parts of absolute ethyl alcohol and 15 parts of distilled water into the mixture, and stirring and mixing for 15min at room temperature; and continuously heating to 120 ℃, reacting for 50min, filtering and drying to obtain the product.

Wherein the weight ratio of the aluminum nitride to the silicon carbide is 1.2: 1; the grain diameter of the aluminum nitride and the silicon carbide is 2 mu m; the aluminum nitride having a particle size of 2 μm was purchased from kralmar reagent, model 1227149285; the silicon carbide with the grain diameter of 2 mu m is purchased from south China Diamond Mill of Topti City, and the model is W_2.5(ii) a The coupling agent is KR-38S isopropyl trititanate.

Embodiment 1 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 2

The embodiment 2 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which comprises the following steps:

step one, preparation of a component A: according to the parts by weight, under the stirring condition, 80 parts of epoxy resin, 5 parts of diluent, 0.1 part of defoaming agent, 3 parts of toughening agent, 15 parts of filler and 3 parts of auxiliary agent are sequentially added, and after uniform stirring and mixing, the component A is obtained;

step two, preparation of the component B: sequentially adding 50 parts of curing agent and 2 parts of accelerator by weight under the stirring condition, and uniformly stirring and mixing to obtain a component B;

step three, preparing pouring sealant: and (3) mixing the component A obtained in the step one and the component B obtained in the step two according to the ratio of 2: 1, uniformly mixing and stirring, and performing vacuum defoaming, filling and sealing and curing to obtain the pouring sealant for the lightweight locomotive electrical equipment.

The epoxy resin is bisphenol A epoxy resin which is purchased from Hezhou Lebang composite material Co., Ltd, and has the model of Showa R-806. The diluent is ethylene glycol diglycidyl ether, has CAS number 2224-15-9, and is purchased from Senffida chemical Co., Ltd. The defoamer is polydimethylsiloxane with the CAS number of 9006-65-9, and purchased from Nantong Runfeng petrochemical Co. The toughening agent is glass fiber. The auxiliary agent is a German Bick BYK-410 anti-settling agent, carbon black and red phosphorus, and the weight ratio of the German Bick BYK-410 anti-settling agent to the carbon black to the red phosphorus is 2: 1: 2.5; the carbon black was purchased from Heizhou Fengsho chemical Co., Ltd; the red phosphorus, Suzhou sea plasticizing Co. The curing agent is polyether amine and alicyclic amine, and the weight ratio of the polyether amine to the alicyclic amine is 0.7: 1; the polyether amine is purchased from Wuxi Ministry drying chemical company, and has the model number of D230; the alicyclic amine was purchased from Shanghai Rixi chemical technology, Inc. with model number 1016B. The accelerator is 2, 4, 6-tris (dimethylaminomethyl) phenol, purchased from Bangzhou Lebang composite Co., Ltd, and has the model number DMP-30.

The filler comprises 6 parts by weight of a mixture of modified aluminum nitride and silicon carbide, 1 part by weight of calomel and 9 parts by weight of a mixture of spherical micro silicon powder and hollow microspheres. The calomel is purchased from Kunjang chemical Co., Ltd, Suzhou, and the model is HDKT 40; the weight ratio of the spherical micro silicon powder to the hollow microspheres is 1: 0.2; the particle size of the spherical micro silicon powder is 25 mu m, and the spherical micro silicon powder is purchased from Zhanghuayuan scientific and technology limited company in Beijing and has the model number of HS-304; the preparation method of the hollow microspheres coated by the polyurethane prepolymer is the same as that of example 1.

The preparation method of the mixture modified by the aluminum nitride and the silicon carbide is the same as that of the example 1.

Wherein the weight ratio of the aluminum nitride to the silicon carbide is 1: 1; the grain diameter of the aluminum nitride and the silicon carbide is 2 mu m; the aluminum nitride having a particle size of 2 μm was purchased from kralmar reagent, model 1227149285; the silicon carbide with the grain diameter of 2 mu m is purchased from south China Diamond Mill of Topti City, and the model is W_2.5(ii) a The coupling agent is KR-38S isopropyl trititanate.

Embodiment 2 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 3

The embodiment 3 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which comprises the following steps:

step one, preparation of a component A: according to the parts by weight, under the stirring condition, 90 parts of epoxy resin, 15 parts of diluent, 0.3 part of defoaming agent, 5 parts of toughening agent, 40 parts of filler and 8 parts of auxiliary agent are sequentially added, and after uniform stirring and mixing, the component A is obtained;

step two, preparation of the component B: according to the parts by weight, sequentially adding 90 parts of curing agent and 15 parts of accelerator under the stirring condition, and uniformly stirring and mixing to obtain a component B;

step three, preparing pouring sealant: and (3) mixing the component A obtained in the step one and the component B obtained in the step two according to the ratio of 5: 1, uniformly mixing and stirring, and performing vacuum defoaming, filling and sealing and curing to obtain the pouring sealant for the lightweight locomotive electrical equipment.

The epoxy resin is bisphenol A epoxy resin which is purchased from Hezhou Lebang composite material Co., Ltd, and has the model of Showa R-806. The diluent is ethylene glycol diglycidyl ether, has CAS number 2224-15-9, and is purchased from Senffida chemical Co., Ltd. The defoamer is polydimethylsiloxane with the CAS number of 9006-65-9, and purchased from Nantong Runfeng petrochemical Co. The toughening agent is glass fiber. The auxiliary agent is a German Bick BYK-410 anti-settling agent, carbon black and red phosphorus, and the weight ratio of the German Bick BYK-410 anti-settling agent to the carbon black to the red phosphorus is 2: 1: 2.5; the carbon black was purchased from Heizhou Fengsho chemical Co., Ltd; the red phosphorus, Suzhou sea plasticizing Co. The curing agent is polyether amine and alicyclic amine, and the weight ratio of the polyether amine to the alicyclic amine is 0.8: 1; the polyether amine is purchased from Wuxi Ministry drying chemical company, and has the model number of D230; the alicyclic amine was purchased from Shanghai Rixi chemical technology, Inc. with model number 1016B. The accelerator is 2, 4, 6-tris (dimethylaminomethyl) phenol, purchased from Bangzhou Lebang composite Co., Ltd, and has the model number DMP-30.

The filler comprises 9 parts by weight of a mixture of modified aluminum nitride and silicon carbide, 2 parts by weight of calomel and 31 parts by weight of a mixture of spherical micro silicon powder and hollow microspheres. The calomel is purchased from Kun gang chemical Co., Suzhou, and the model is HDK T40; the weight ratio of the spherical micro silicon powder to the hollow microspheres is 1: 0.35; the particle size of the spherical micro silicon powder is 25 mu m, and the spherical micro silicon powder is purchased from Zhanghuayuan scientific and technology limited company in Beijing and has the model number of HS-304; the preparation method of the hollow microspheres coated by the polyurethane prepolymer is the same as that of example 1.

Wherein the weight ratio of the aluminum nitride to the silicon carbide is 1.5: 1; the aluminum nitrideAnd the particle size of the silicon carbide is 2 μm; the aluminum nitride having a particle size of 2 μm was purchased from kralmar reagent, model 1227149285; the silicon carbide with the grain diameter of 2 mu m is purchased from south China Diamond Mill of Topti City, and the model is W_2.5(ii) a The coupling agent is KR-38S isopropyl trititanate.

Embodiment 3 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 4

Embodiment 4 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the molar ratio of hexamethylene diisocyanate to L-lysine triisocyanate in isocyanate is changed from 4: 1 is replaced by 3: 1.

embodiment 4 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 5

Embodiment 5 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the molar ratio of hexamethylene diisocyanate to L-lysine triisocyanate in isocyanate is changed from 4: 1 is replaced by 5: 1.

embodiment 5 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 6

The embodiment 6 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which has a specific implementation mode similar to that of the embodiment 1, and is characterized in that the weight ratio of spherical micro silicon powder to hollow microspheres is controlled from 1: 0.275 was replaced by 1: 0.15.

embodiment 6 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 7

Embodiment 7 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation manner, and is characterized in that the weight ratio of spherical micro silicon powder to hollow microspheres is controlled from 1: 0.275 was replaced by 1: 0.35.

embodiment 7 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 8

The embodiment 8 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to that in embodiment 1, and is different in that the particle size of spherical micro silicon powder is changed from 25 micrometers to 7 micrometers, and the spherical micro silicon powder is purchased from Beijing Zhonghuayuan science and technology Co., Ltd, and is HS-302 in model.

Embodiment 8 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 9

Embodiment 9 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation mode, and is different in that the particle size of spherical silica fume is replaced by 85 μm from 25 μm, which is purchased from Zhanghuayuan scientific and technological limited company in Beijing and is of a model number HS-305.

Embodiment 9 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 10

Embodiment 10 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation, and is different in that the particle size of spherical silica fume is changed from 25 μm to 50 μm.

Embodiment 10 also provides a potting adhesive for lightweight locomotive electrical equipment.

Example 11

Embodiment 11 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the particle size of the cenospheres is replaced by 40 μm from 50 μm, which is purchased from shanxi honor science and technology ltd, and is model number HN60D 50.

Embodiment 11 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 12

Embodiment 12 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the particle size of the cenospheres is replaced by 65 μm from 50 μm, which is purchased from shanxi honor science and technology ltd, and is model number HN20D 50.

Embodiment 12 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 13

Embodiment 13 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the molar ratio of hexamethylene diisocyanate to L-lysine triisocyanate in isocyanate is changed from 4: 1 is replaced by 2.5: 1.

embodiment 13 also provides a potting adhesive for lightweight locomotive electrical equipment.

Example 14

Embodiment 14 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the molar ratio of hexamethylene diisocyanate to L-lysine triisocyanate in isocyanate is changed from 4: 1 was replaced with 5.5: 1.

embodiment 14 also provides a potting adhesive for lightweight locomotive electrical equipment.

Example 15

Embodiment 15 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that in the preparation method of the polyurethane prepolymer-coated hollow microspheres, the coupling agent used in step ② is replaced by a silane coupling agent KH560 instead of isopropyl trititanate, and the coupling agent is purchased from tokyo warp-weft chemical limited company.

Embodiment 15 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 16

The embodiment 16 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to that in embodiment 1, and is different in that high-resilience polyether with a hydroxyl value of 32-36 (mgKOH/g) is replaced by high-resilience polyether with a hydroxyl value of 26-30(mgKOH/g), and the high-resilience polyether is purchased from Guangzhou Brillon chemical industry Co., Ltd and has the model number of EP-3600.

Embodiment 16 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 17

The embodiment 17 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to that in embodiment 1, and is different in that high-resilience polyether with a hydroxyl value of 32-36 (mgKOH/g) is replaced by high-resilience polyether with a hydroxyl value of 26-30(mgKOH/g), and the high-resilience polyether is purchased from Guangzhou Brillon chemical industry Co., Ltd and has the model number of EP-3600.

Embodiment 17 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 18

Embodiment 18 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation manner, except that the weight ratio of aluminum nitride to silicon carbide is from 1.2: 1 was replaced with 0.8: 1.

embodiment 18 also provides a potting adhesive for lightweight locomotive electrical equipment.

Example 19

Embodiment 19 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation manner, except that the weight ratio of aluminum nitride to silicon carbide is from 1.2: 1 is replaced by 1.8: 1.

embodiment 19 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 20

Embodiment 20 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the particle size of aluminum nitride is changed from 2 μm to 12 μm.

Embodiment 20 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 21

Embodiment 21 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1, except that the particle size of the silicon carbide is changed from 2 μm to 12 μm.

Embodiment 21 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 22

Embodiment 22 of the invention provides a preparation method of a pouring sealant for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation, and is different in that a coupling agent used in the preparation method of the mixture modified by aluminum nitride and silicon carbide is replaced by a silane coupling agent KH560 instead of isopropyl trititanate, and the silane coupling agent KH is purchased from Nanjing warp Tian latitude chemical Co.

Embodiment 22 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 23

Embodiment 23 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, which is similar to embodiment 1 in specific implementation manner, except that the filler does not include a mixture of modified aluminum nitride and modified silicon carbide.

Embodiment 23 also provides a pouring sealant for lightweight locomotive electrical equipment.

Example 24

Embodiment 24 of the present invention provides a preparation method of a potting adhesive for lightweight locomotive electrical equipment, including the following steps:

step one, preparation of a component A: according to the parts by weight, 85 parts of epoxy resin, 30 parts of polyurethane, 10 parts of diluent, 0.2 part of defoaming agent, 4 parts of toughening agent, 27.5 parts of filler and 5.5 parts of auxiliary agent are sequentially added under the stirring condition, and after the components are uniformly stirred and mixed, the component A is obtained;

The epoxy resin is bisphenol A epoxy resin which is purchased from Hezhou Lebang composite material Co., Ltd, and has the model of Showa R-806. The polyurethane was purchased from basf, germany, model ES80a 15. The diluent is ethylene glycol diglycidyl ether, has CAS number 2224-15-9, and is purchased from Senffida chemical Co., Ltd. The defoamer is polydimethylsiloxane with the CAS number of 9006-65-9, and purchased from Nantong Runfeng petrochemical Co. The toughening agent is glass fiber. The auxiliary agent is a German Bick BYK-410 anti-settling agent, carbon black and red phosphorus, and the weight ratio of the German Bick BYK-410 anti-settling agent to the carbon black to the red phosphorus is 2: 1: 2.5; the carbon black was purchased from Heizhou Fengsho chemical Co., Ltd; the red phosphorus, Suzhou sea plasticizing Co. The curing agent is polyether amine and alicyclic amine, and the weight ratio of the polyether amine to the alicyclic amine is 0.75: 1; the polyether amine is purchased from Wuxi Ministry drying chemical company, and has the model number of D230; the alicyclic amine was purchased from Shanghai Rixi chemical technology, Inc. with model number 1016B. The accelerator is 2, 4, 6-tris (dimethylaminomethyl) phenol, purchased from Bangzhou Lebang composite Co., Ltd, and has the model number DMP-30.

The filler comprises 7.5 parts by weight of a mixture of modified aluminum nitride and silicon carbide, 1.5 parts by weight of calomel and 20 parts by weight of a mixture of spherical micro silicon powder and hollow microspheres. The calomel is purchased from Kun gang chemical Co., Suzhou, and the model is HDK T40; the weight ratio of the spherical micro silicon powder to the hollow microspheres is 1: 0.275; the particle size of the spherical micro silicon powder is 25 mu m, and the spherical micro silicon powder is purchased from Zhanghuayuan scientific and technology limited company in Beijing and has the model number of HS-304; the hollow microspheres are hollow glass microspheres coated by polyurethane prepolymer, and the preparation method is the same as that of example 1.

Embodiment 24 also provides a pouring sealant for lightweight locomotive electrical equipment.

Evaluation of Performance

1. Cracking resistance: a cured sample having a length of 125mm, a width of 13mm and a thickness of 5mm was prepared from the potting adhesive for lightweight automotive electrical equipment obtained in examples 1 to 17 and examples 23 and 24, a notch having a depth of 0.5mm and parallel to the broad side was cut in the middle of the sample, the notch was placed face up on a sample bending apparatus, and the bending apparatus was closed within 30 seconds. Transferring the bent sample into a sample holder, respectively placing the sample into test tubes containing reagents preset to-40 ℃ and 120 ℃, wherein the liquid level of the reagents is about 10mm higher than the holder, plugging the test tubes by using plugs coated with aluminum foils, quickly placing the test tubes into a constant-temperature bath tank which meets the temperature requirement, and recording the damage time of the sample, wherein the results are shown in table 1.

TABLE 1 cracking resistance test results

2. Flame retardant property: cured samples having a length of 125mm, a width of 13mm and a thickness of 5mm were prepared from the potting adhesive for lightweight locomotive electrical equipment obtained in examples 1 to 5, 18 to 22 and 24 according to GB/T2408-2008 "horizontal method and vertical method for measuring Plastic Combustion Performance". Respectively fixing the samples on a vertical clamp, exposing the other end of the vertical clamp in test flame A, applying flame to the samples for 10s, immediately withdrawing the flame to a sufficient distance so as not to influence the samples, and recording the time of the first afterflame; immediately putting the test flame below the sample again after the afterflame of the sample is extinguished, repeating the operation, recording the afterflame time and the afterglow time for the second time, calculating data and comparing the data with a standard criterion, wherein the result is shown in Table 2.

TABLE 2 flame retardancy test results

3. Coefficient of thermal conductivity: the pouring sealant for lightweight locomotive electrical equipment obtained in examples 1 to 12, 18 to 21 and 24 was used to prepare a cured sample with a length of 50mm, a width of 50mm and a thickness of 5mm according to GB/T3399-.

TABLE 3 thermal conductivity test results

4. Impact strength: cured samples of 80mm long, 10mm wide and 4mm thick obtained by using the potting adhesive for lightweight locomotive electrical equipment obtained in examples 1 to 17 and examples 23 and 24 were prepared according to GB-T1043.1-2008 "determination of impact properties of plastic simple beam part 1 non-instrumented impact test", and the samples were all non-notched samples, and the maximum impact strength of the samples when the samples were damaged was measured using an XJJD-5 type impact strength tester, and the results are shown in table 4.

TABLE 4 impact Strength test results

5. Bending strength: according to GB/T9341-2008 'determination of Plastic bending Property', the pouring sealant for lightweight locomotive electrical equipment obtained in examples 1-5, 16-17, 23 and 24 is used to prepare a cured sample with a length of 80mm, a width of 10mm and a thickness of 4mm, and a bending strength tester is used to test the maximum bending stress borne by the sample at 25 ℃, namely the bending strength, and the results are shown in Table 5.

TABLE 5 flexural Strength test results

	Flexural Strength/MPa
		Example 1	70
Example 2	68
		Example 3	68
Example 4	67
		Example 5	66
Example 16	41
		Example 17	46
Example 23	66
		Example 24	68

The combination of the above experimental results shows that: the pouring sealant mainly uses epoxy resin, filler and other reagents, and the pouring sealant for the lightweight locomotive electrical equipment with excellent performance is prepared. Experimental test results show that the crack resistance of the pouring sealant prepared by the preparation method can reach 2100h and 2300h at-40 ℃ and 120 ℃ respectively; the flame retardant property test shows that the flame retardant has excellent flame retardant property; the heat conductivity test shows that the heat conductivity coefficient can reach 1.85W/(m.K); the impact strength test shows that the maximum impact strength born by the sample when the sample is damaged can reach 6 KJ.m²(ii) a The bending strength test shows that the maximum bending stress born at 25 ℃ can reach 70 MPa. In addition, the present invention is based on the use of polyurethane prepolymersThe pouring sealant prepared from light weight fillers such as body, calomel (fumed silica), pretreated micro silicon powder, micro beads and the like, high-toughness low-density enhanced fibers and high-hydroxyl value polyol also has excellent electrical performance, excellent vibration fatigue resistance and lower density (1 g/cm)³Left and right), can meet the use requirements of different types of locomotive electrical equipment, and has strong industrial application value and development prospect.

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. The invention is not limited to the embodiments described above, but rather, many modifications and variations may be made by one skilled in the art without departing from the scope of the invention.

Claims

1. The preparation method of the pouring sealant for the lightweight locomotive electrical equipment is characterized by comprising the following steps of:

2. The preparation method of the pouring sealant for the lightweight locomotive electrical equipment according to claim 1, wherein the component A further comprises 20-40 parts by weight of polyurethane.

3. The preparation method of the pouring sealant for the light-weight locomotive electrical equipment according to claim 1, wherein the toughening agent is a toughening polymer and/or a reinforcing fiber.

4. The preparation method of the pouring sealant for the light-weight locomotive electrical equipment according to claim 1, wherein the filler is spherical silica fume and hollow microspheres.

5. The preparation method of the pouring sealant for the lightweight locomotive electrical equipment according to claim 4, wherein the weight ratio of the spherical silica fume to the hollow micro-beads is 1: (0.2-0.35).

6. The preparation method of the pouring sealant for the lightweight locomotive electrical equipment according to claim 4 or 5, wherein the particle size of the spherical silica fume is 20-35 μm.

7. The preparation method of the pouring sealant for the lightweight locomotive electrical equipment according to claim 4, wherein the particle size of the cenospheres is 45-60 μm.

8. The preparation method of the pouring sealant for the light-weight locomotive electrical equipment according to claim 4, wherein the cenospheres are cenospheres coated by a prepolymer.

9. The preparation method of the pouring sealant for the light-weight locomotive electrical equipment according to claim 4, wherein the filler further comprises one or more of light weight powder, aluminum oxide, zinc oxide, aluminum nitride, boron nitride, silicon carbide, montmorillonite, carbon nanotube, graphene and barite.

10. A pouring sealant for lightweight locomotive electrical equipment, which is characterized by being prepared by the preparation method of any one of claims 1 to 9.