CN114249964A - Pouring inorganic mineral insulated bus - Google Patents

Abstract

The invention discloses a poured inorganic mineral insulated bus, which comprises a bus body and an inorganic mineral insulating layer arranged on the surface of the bus body; the inorganic mineral insulating layer comprises the following components in parts by weight: 48-56 parts of silane-terminated polyether modified epoxy resin, 16-22 parts of terephthalate-coated scandium silicate/yttrium silicate microspheres, 15-20 parts of quartz sand, 12-18 parts of aluminum oxide, 5-10 parts of neodymium oxide, 2-6 parts of a dispersing agent, 2-5 parts of a flame retardant, 0.5-1 part of an antioxidant and 20-38 parts of a curing agent. The invention discloses a cast inorganic mineral insulated bus, wherein an inorganic mineral insulating layer is arranged on the surface layer of the bus, and the inorganic mineral insulating layer has better insulativity, mechanical strength, high temperature resistance and corrosion resistance.

Description

Pouring inorganic mineral insulated bus

Technical Field

The invention relates to the field of insulated buses, in particular to a poured inorganic mineral insulated bus.

Background

Along with the development of national electric power, the main transformer capacity of a transformer substation is increased, the working current of the secondary side of a transformer is continuously increased, a bus is one of key equipment (materials) in an electric power transmission and transformation system, plays a vital role in the safe and reliable operation of the electric power transmission and transformation system and the electric power equipment, is mainly applied to conductor connection between a power grid transmission wire and a transformer of the transformer substation in the electric power construction engineering of China, a jumper wire in a power transmission line, a connecting conductor in the electric power equipment and an overcurrent conductor in a high-current direct-current deicing device, is a brand new conductor for replacing the traditional rectangular, groove-shaped, bar-shaped bus and flexible conductor, is one of key equipment (materials) in the electric power transmission and transformation system, and plays a vital role in the safe and reliable operation of the electric power transmission and transformation system and the electric power equipment

The existing cast bus is difficult to meet the electrical operation requirement in a narrow space and a severe environment, and in the limited space, although the cast bus has good electrical insulation performance, the mechanical strength and the chemical resistance of the cast bus are poor, and the service life of the cast bus is short.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a cast inorganic mineral insulated bus.

The purpose of the invention is realized by adopting the following technical scheme:

a cast inorganic mineral insulated bus comprises a bus body and an inorganic mineral insulating layer arranged on the surface of the bus body; the inorganic mineral insulating layer comprises the following components in parts by weight:

48-56 parts of silane-terminated polyether modified epoxy resin, 16-22 parts of terephthalate-coated scandium silicate/yttrium silicate microspheres, 15-20 parts of quartz sand, 12-18 parts of aluminum oxide, 5-10 parts of neodymium oxide, 2-6 parts of a dispersing agent, 2-5 parts of a flame retardant, 0.5-1 part of an antioxidant and 20-38 parts of a curing agent.

Preferably, the thickness of the inorganic mineral insulating layer is 25-35 mm.

Preferably, the preparation method of the silane-terminated polyether modified epoxy resin comprises the following steps:

s1, weighing bisphenol A type epoxy resin and silane terminated polyether, mixing the bisphenol A type epoxy resin and the silane terminated polyether into absolute ethyl alcohol, uniformly mixing, heating to 65-80 ℃, performing reflux treatment for 1-2 hours, and cooling to room temperature to obtain a first epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the silane-terminated polyether to the absolute ethyl alcohol is 1: 0.8-1.2: 3-6;

s2, weighing bisphenol A type epoxy resin again, adding an organic tin catalyst, uniformly mixing, heating to 65-80 ℃, stirring for 2-4 hours, and cooling to room temperature to obtain a second epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the organotin catalyst is 1: 0.02-0.05;

s3, mixing the first epoxy resin mixture with the second epoxy resin mixture, adding polymethylphenylsiloxane, stirring and mixing uniformly, and removing absolute ethyl alcohol to obtain silane-terminated polyether modified epoxy resin;

wherein the mass ratio of the first epoxy resin mixture to the second epoxy resin mixture is 1: 0.4-0.6.

Preferably, the molecular weight of the silane-terminated polyether is 10000-20000.

Preferably, the organic tin catalyst is one of dibutyltin dilaurate, stannous octoate and dibutyltin didodecyl sulfide.

Preferably, the preparation method of the terephthalic acid ester coated scandium silicate/yttrium silicate microspheres comprises the following steps:

(1) preparing nano scandium silicate/yttrium silicate:

s1, weighing ethyl orthosilicate, mixing the ethyl orthosilicate with an ethanol solution, uniformly dispersing, dropwise adding a mixed solution of scandium chloride and yttrium chloride while stirring, and continuously stirring for 6-10 hours after dropwise adding is finished to obtain a scandium silicate/yttrium silicate precursor;

wherein the mass fraction of the ethanol solution is 35-55%; the mixed solution of scandium chloride and yttrium chloride is obtained by mixing scandium chloride, yttrium chloride and deionized water according to the mass ratio of 1: 0.23-0.36: 4-6; the mass ratio of the ethyl orthosilicate and the ethanol solution to the mixed solution of scandium chloride and yttrium chloride is 1: 1.2-1.6: 2.5-4.8;

s2, carrying out reduced pressure drying on the scandium silicate/yttrium silicate precursor, then placing the scandium silicate/yttrium silicate precursor in a reaction furnace, heating to 900-1000 ℃, carrying out heat preservation treatment for 1-3 h, then heating to 1250-1400 ℃ again, carrying out heat preservation treatment for 2-4 h, naturally cooling to room temperature, and carrying out ball milling to obtain nano scandium silicate/yttrium silicate;

(2) hydroxylated scandium silicate/yttrium silicate:

weighing 3- [ bis (2-hydroxyethyl) amino ] propane triethoxysilane, mixing with deionized water, dispersing uniformly, adding nano scandium silicate/yttrium silicate, heating to 55-65 ℃, stirring for 5-10 h, centrifuging, washing the obtained lower-layer solid with pure water for three times, and drying under reduced pressure to obtain hydroxylated scandium silicate/yttrium silicate;

wherein the mass ratio of the nano scandium silicate/yttrium silicate, aminopropyl triethoxysilane to deionized water is 1: 0.1-0.3: 5-8;

(3) preparing terephthalate-coated scandium silicate/yttrium silicate microspheres:

dispersing hydroxylated scandium silicate/yttrium silicate into N, N-dimethylformamide, adding terephthalic acid and phosphotungstic acid, heating to 120-140 ℃, stirring for 4-6 hours, filtering, washing and drying obtained filter residues to obtain terephthalic acid ester coated scandium silicate/yttrium silicate microspheres;

wherein the mass ratio of the hydroxylated scandium silicate to the yttrium silicate to the terephthalic acid to the phosphotungstic acid to the N, N-dimethylformamide is 1: 0.53-0.65: 0.03-0.06: 5-10.

Preferably, the particle size of the nano scandium silicate/yttrium silicate is 300-600 nm.

Preferably, the particle size of the quartz sand is 10-100 μm.

Preferably, the particle size of the alumina is 1-10 μm.

Preferably, the particle size of the neodymium oxide is 100-500 nm.

Preferably, the dispersant is polyethylene glycol.

Preferably, the antioxidant is one of diphenylphosphine oxide, dimethyl phosphite and dibenzyl phosphite.

Preferably, the flame retardant is an organic phosphorus ester flame retardant, and comprises one or more of alkyl phosphate, condensed phosphate and phenyl phosphate.

Preferably, the curing agent is N, N-diethyl-1, 3-propanediamine or N- (2-hydroxyethyl) ethylenediamine.

Preferably, the preparation method of the cast inorganic mineral insulated bus bar comprises the following steps:

step 1, weighing silane-terminated polyether modified epoxy resin according to parts by weight, mixing the silane-terminated polyether modified epoxy resin with a dispersing agent, uniformly dispersing, adding terephthalate coated scandium silicate/yttrium silicate microspheres, heating to 50-60 ℃, stirring and mixing for 0.5-1 h, and cooling to room temperature to obtain a first mixed material;

step 2, weighing quartz sand, aluminum oxide and neodymium oxide according to the weight parts, mixing the quartz sand, the aluminum oxide and the neodymium oxide into the first mixed material, stirring and mixing uniformly, then adding the flame retardant and the antioxidant which are weighed according to the weight parts, and mixing uniformly again to obtain a second mixed material;

step 3, weighing a curing agent according to the weight parts, adding the curing agent into the second mixed material, and fully mixing to obtain an epoxy resin casting mixed material;

step 4, cleaning the bus, placing the bus in a casting mold, and injecting the epoxy resin casting mixture into the casting mold to enable the epoxy resin casting mixture to completely wrap the bus;

and 5, placing the casting mold filled with the bus and the epoxy resin casting mixture into a reaction furnace for curing, and demolding to obtain the cast inorganic mineral insulated bus.

Preferably, in the step 4, the bus bar is placed after the mold release agent is coated inside the casting mold.

Preferably, in the step 4, ethanol or acetone is used for cleaning the bus.

Preferably, in the step 5, the temperature of the reaction furnace is raised to 110-120 ℃ for curing, the temperature is maintained for 2-3 h, then raised to 140-150 ℃ for curing for 1-2 h.

The invention has the beneficial effects that:

the invention discloses a cast inorganic mineral insulated bus, wherein an inorganic mineral insulating layer is arranged on the surface layer of the bus, and the inorganic mineral insulating layer has better insulativity, mechanical strength, high temperature resistance and corrosion resistance.

Epoxy resin has the advantages of good insulation, corrosion resistance, dimensional stability, adhesion and the like, but has insufficient high temperature resistance and toughness. According to the invention, silane-terminated polyether is firstly used for modification treatment, and then the silane-terminated polyether is mixed with terephthalic acid ester coated scandium silicate/yttrium silicate microspheres for modification, so that the toughness and other mechanical properties of epoxy resin are increased by combining the silane-terminated polyether and the terephthalic acid ester coated scandium silicate/yttrium silicate microspheres, and then other mixed materials are added, and finally the inorganic mineral insulating material is prepared and poured on the surface layer of the bus.

The prepared terephthalate-coated scandium silicate/yttrium silicate microsphere is of a shell-core structure, namely the microsphere obtained by taking nano scandium silicate/yttrium silicate as a core and terephthalate as a shell. The terephthalic acid ester serving as the shell of the microsphere can enhance the crosslinking property with the silane-terminated polyether modified epoxy resin, so that the microsphere is dispersed more uniformly, and meanwhile, the polyester microsphere has a certain modification effect on the silane-terminated polyether modified epoxy resin; compared with the conventional preparation of single metal silicate, the nano scandium silicate/yttrium silicate is prepared by combining scandium and yttrium, so that the scandium and yttrium can compensate each other, the effect which cannot be achieved by any single metal can be achieved, for example, the scandium and yttrium silicate has higher strength or stability, and the scandium and yttrium silicate serving as an inner core not only enhances the mechanical property, but also increases the thermal conductivity and the flame retardance.

Detailed Description

The invention is further described below with reference to the following examples.

Example 1

A cast inorganic mineral insulated bus comprises a bus body and an inorganic mineral insulating layer arranged on the surface of the bus body; the thickness of the inorganic mineral insulating layer is 30 mm;

the inorganic mineral insulating layer comprises the following components in parts by weight:

52 parts of silane-terminated polyether modified epoxy resin, 18 parts of terephthalate-coated scandium silicate/yttrium silicate microspheres, 17 parts of quartz sand, 15 parts of aluminum oxide, 7 parts of neodymium oxide, 4 parts of polyethylene glycol, 3 parts of alkyl phosphate, 0.5 part of diphenylphosphoric acid and 30 parts of N, N-diethyl-1, 3-propanediamine.

The particle size of the quartz sand is 10-100 mu m; the particle size of the alumina is 1-10 mu m; the particle size of the neodymium oxide is 100 to 500 nm.

The preparation method of the silane-terminated polyether modified epoxy resin comprises the following steps:

s1, weighing bisphenol A type epoxy resin and silane terminated polyether, mixing the bisphenol A type epoxy resin and the silane terminated polyether into absolute ethyl alcohol, uniformly mixing, heating to 75 ℃, performing reflux treatment for 2 hours, and cooling to room temperature to obtain a first epoxy resin mixture;

wherein the molecular weight of the silane terminated polyether is 10000-20000, and the mass ratio of the bisphenol A type epoxy resin to the silane terminated polyether to the absolute ethyl alcohol is 1:1: 4;

s2, weighing bisphenol A type epoxy resin again, adding dibutyltin dilaurate, uniformly mixing, heating to 75 ℃, stirring for 3 hours, and cooling to room temperature to obtain a second epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the dibutyltin dilaurate is 1: 0.03;

s3, mixing the first epoxy resin mixture with the second epoxy resin mixture, adding polymethylphenylsiloxane, stirring and mixing uniformly, and removing absolute ethyl alcohol to obtain silane-terminated polyether modified epoxy resin;

wherein the mass ratio of the first epoxy resin mixture to the second epoxy resin mixture is 1: 0.5.

The preparation method of the terephthalic acid ester coated scandium silicate/yttrium silicate microspheres comprises the following steps:

(1) preparing nano scandium silicate/yttrium silicate:

s1, weighing ethyl orthosilicate, mixing the ethyl orthosilicate with an ethanol solution, uniformly dispersing, dropwise adding a mixed solution of scandium chloride and yttrium chloride while stirring, and continuously stirring for 8 hours after dropwise adding is finished to obtain a scandium silicate/yttrium silicate precursor;

wherein the mass fraction of the ethanol solution is 45 percent; the mixed solution of scandium chloride and yttrium chloride is obtained by mixing scandium chloride, yttrium chloride and deionized water according to the mass ratio of 1:0.28: 5; the mass ratio of the ethyl orthosilicate and the ethanol solution to the mixed solution of the scandium chloride and the yttrium chloride is 1:1.4: 3.6;

s2, carrying out reduced pressure drying on the scandium silicate/yttrium silicate precursor, then placing the scandium silicate/yttrium silicate precursor in a reaction furnace, heating to 1000 ℃, carrying out heat preservation treatment for 2 hours, then heating to 1350 ℃, carrying out heat preservation treatment for 3 hours, naturally cooling to room temperature, and then carrying out ball milling on the scandium silicate/yttrium silicate precursor into nano particles with the particle size of 300-600 nm to obtain nano scandium silicate/yttrium silicate;

(2) hydroxylated scandium silicate/yttrium silicate:

weighing 3- [ bis (2-hydroxyethyl) amino ] propane triethoxysilane, mixing with deionized water, dispersing uniformly, adding nano scandium silicate/yttrium silicate, heating to 60 ℃, stirring for 8h, centrifuging, washing the obtained lower layer solid with pure water for three times, and drying under reduced pressure to obtain hydroxylated scandium silicate/yttrium silicate;

wherein the mass ratio of the nano scandium silicate/yttrium silicate to the aminopropyl triethoxysilane to the deionized water is 1:0.2: 6;

(3) preparing terephthalate-coated scandium silicate/yttrium silicate microspheres:

dispersing hydroxylated scandium silicate/yttrium silicate into N, N-dimethylformamide, adding terephthalic acid and phosphotungstic acid, heating to 130 ℃, stirring for 5 hours, filtering, washing and drying obtained filter residues to obtain terephthalic acid ester coated scandium silicate/yttrium silicate microspheres;

wherein the mass ratio of the hydroxylated scandium silicate to the yttrium silicate to the terephthalic acid to the phosphotungstic acid to the N, N-dimethylformamide is 1:0.58:0.04: 8.

The preparation method of the cast inorganic mineral insulated bus comprises the following steps:

step 1, weighing silane-terminated polyether modified epoxy resin according to parts by weight, mixing the silane-terminated polyether modified epoxy resin with polyethylene glycol, uniformly dispersing, adding terephthalate coated scandium silicate/yttrium silicate microspheres, heating to 55 ℃, stirring and mixing for 0.8h, and cooling to room temperature to obtain a first mixed material;

step 2, weighing quartz sand, aluminum oxide and neodymium oxide according to the weight parts, mixing the quartz sand, the aluminum oxide and the neodymium oxide into the first mixed material, stirring and mixing the mixture uniformly, then adding alkyl phosphate and diphenyl phosphorus oxide weighed according to the weight parts, and mixing the mixture uniformly again to obtain a second mixed material;

step 3, weighing N, N-diethyl-1, 3-propane diamine according to the weight parts, adding the N, N-diethyl-1, 3-propane diamine into the second mixed material, and fully mixing to obtain an epoxy resin casting mixed material;

step 4, taking the bus cleaned by ethanol or acetone, placing the bus into a casting mold, coating a release agent in the casting mold, then placing the bus, and injecting the epoxy resin casting mixture into the casting mold to enable the epoxy resin casting mixture to completely wrap the bus;

and 5, placing the casting mold filled with the bus and the epoxy resin casting mixture into a reaction furnace, heating to 115 ℃, carrying out heat preservation treatment for 2.5 hours, heating to 145 ℃, carrying out heat preservation treatment for 2 hours, and demolding to obtain the cast inorganic mineral insulated bus.

Example 2

A cast inorganic mineral insulated bus comprises a bus body and an inorganic mineral insulating layer arranged on the surface of the bus body; the thickness of the inorganic mineral insulating layer is 25 mm;

the inorganic mineral insulating layer comprises the following components in parts by weight:

48 parts of silane-terminated polyether modified epoxy resin, 16 parts of terephthalate-coated scandium silicate/yttrium silicate microspheres, 15 parts of quartz sand, 12 parts of aluminum oxide, 5 parts of neodymium oxide, 2 parts of dispersing agent, 2 parts of flame retardant, 0.5 part of antioxidant and 20 parts of curing agent.

The particle size of the quartz sand is 10-100 mu m; the particle size of the alumina is 1-10 mu m; the particle size of the neodymium oxide is 100-500 nm;

the preparation method of the silane-terminated polyether modified epoxy resin comprises the following steps:

s1, weighing bisphenol A type epoxy resin and silane terminated polyether, mixing the bisphenol A type epoxy resin and the silane terminated polyether into absolute ethyl alcohol, uniformly mixing, heating to 65 ℃, performing reflux treatment for 1 hour, and cooling to room temperature to obtain a first epoxy resin mixture;

wherein the molecular weight of the silane terminated polyether is 10000-20000, and the mass ratio of the bisphenol A type epoxy resin to the silane terminated polyether to the absolute ethyl alcohol is 1:0.8: 3;

s2, weighing bisphenol A type epoxy resin again, adding stannous octoate, uniformly mixing, heating to 65-80 ℃, stirring for 2-4 hours, and cooling to room temperature to obtain a second epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the stannous octoate is 1: 0.02;

s3, mixing the first epoxy resin mixture with the second epoxy resin mixture, adding polymethylphenylsiloxane, stirring and mixing uniformly, and removing absolute ethyl alcohol to obtain silane-terminated polyether modified epoxy resin;

wherein the mass ratio of the first epoxy resin mixture to the second epoxy resin mixture is 1: 0.4.

The preparation method of the terephthalic acid ester coated scandium silicate/yttrium silicate microspheres comprises the following steps:

(1) preparing nano scandium silicate/yttrium silicate:

s1, weighing ethyl orthosilicate, mixing the ethyl orthosilicate with an ethanol solution, uniformly dispersing, dropwise adding a mixed solution of scandium chloride and yttrium chloride while stirring, and continuously stirring for 6 hours after dropwise adding is finished to obtain a scandium silicate/yttrium silicate precursor;

wherein the mass fraction of the ethanol solution is 35 percent; the mixed solution of scandium chloride and yttrium chloride is obtained by mixing scandium chloride, yttrium chloride and deionized water according to the mass ratio of 1:0.23: 4; the mass ratio of the ethyl orthosilicate and the ethanol solution to the mixed solution of scandium chloride and yttrium chloride is 1:1.2: 2.5;

s2, carrying out reduced pressure drying on the scandium silicate/yttrium silicate precursor, then placing the scandium silicate/yttrium silicate precursor in a reaction furnace, heating to 900 ℃, carrying out heat preservation treatment for 1h, heating to 1250 ℃, carrying out heat preservation treatment for 2h, naturally cooling to room temperature, and carrying out ball milling to obtain nano scandium silicate/yttrium silicate with the particle size of 300-600 nm;

(2) hydroxylated scandium silicate/yttrium silicate:

weighing 3- [ bis (2-hydroxyethyl) amino ] propane triethoxysilane, mixing with deionized water, dispersing uniformly, adding nano scandium silicate/yttrium silicate, heating to 55 ℃, stirring for 5h, centrifuging, washing the obtained lower layer solid with pure water for three times, and drying under reduced pressure to obtain hydroxylated scandium silicate/yttrium silicate;

wherein the mass ratio of the nano scandium silicate/yttrium silicate to the aminopropyl triethoxysilane to the deionized water is 1:0.1: 5;

(3) preparing terephthalate-coated scandium silicate/yttrium silicate microspheres:

dispersing hydroxylated scandium silicate/yttrium silicate into N, N-dimethylformamide, adding terephthalic acid and phosphotungstic acid, heating to 120 ℃, stirring for 4 hours, filtering, washing and drying obtained filter residues to obtain terephthalic acid ester coated scandium silicate/yttrium silicate microspheres;

wherein the mass ratio of the hydroxylated scandium silicate to the yttrium silicate to the terephthalic acid to the phosphotungstic acid to the N, N-dimethylformamide is 1:0.53:0.03: 5.

The preparation method of the cast inorganic mineral insulated bus comprises the following steps:

step 1, weighing silane-terminated polyether modified epoxy resin according to parts by weight, mixing the silane-terminated polyether modified epoxy resin with polyethylene glycol, uniformly dispersing, adding terephthalate coated scandium silicate/yttrium silicate microspheres, heating to 50 ℃, stirring and mixing for 0.5h, and cooling to room temperature to obtain a first mixed material;

step 2, weighing quartz sand, aluminum oxide and neodymium oxide according to the weight parts, mixing the quartz sand, the aluminum oxide and the neodymium oxide into the first mixed material, stirring and mixing the mixture uniformly, then adding the condensed type phosphate and the dimethyl phosphite which are weighed according to the weight parts, and mixing the mixture uniformly again to obtain a second mixed material;

step 3, weighing N- (2-hydroxyethyl) ethylenediamine according to the weight part, adding the N- (2-hydroxyethyl) ethylenediamine into the second mixed material, and fully mixing to obtain an epoxy resin casting mixed material;

step 4, taking the bus cleaned by ethanol or acetone, placing the bus into a casting mold, coating a release agent in the casting mold, then placing the bus, and injecting the epoxy resin casting mixture into the casting mold to enable the epoxy resin casting mixture to completely wrap the bus;

and 5, placing the casting mold filled with the bus and the epoxy resin casting mixture into a reaction furnace, heating to 110 ℃, carrying out heat preservation treatment for 2-3 h, heating to 140 ℃, carrying out heat preservation treatment for 1h, and demolding to obtain the cast inorganic mineral insulated bus.

Example 3

A cast inorganic mineral insulated bus comprises a bus body and an inorganic mineral insulating layer arranged on the surface of the bus body; the thickness of the inorganic mineral insulating layer is 35 mm;

the inorganic mineral insulating layer comprises the following components in parts by weight:

56 parts of silane-terminated polyether modified epoxy resin, 22 parts of terephthalate-coated scandium silicate/yttrium silicate microspheres, 20 parts of quartz sand, 18 parts of aluminum oxide, 10 parts of neodymium oxide, 6 parts of polyethylene glycol, 5 parts of phenyl phosphate, 1 part of dibenzyl phosphite and 38 parts of N, N-diethyl-1, 3-propanediamine.

The particle size of the quartz sand is 10-100 mu m; the particle size of the alumina is 1-10 mu m; the particle size of the neodymium oxide is 100 to 500 nm.

The preparation method of the silane-terminated polyether modified epoxy resin comprises the following steps:

s1, weighing bisphenol A type epoxy resin and silane terminated polyether, mixing the bisphenol A type epoxy resin and the silane terminated polyether into absolute ethyl alcohol, uniformly mixing, heating to 80 ℃, performing reflux treatment for 2 hours, and cooling to room temperature to obtain a first epoxy resin mixture;

wherein the molecular weight of the silane terminated polyether is 10000-20000, and the mass ratio of the bisphenol A type epoxy resin to the silane terminated polyether to the absolute ethyl alcohol is 1:1.2: 6;

s2, weighing bisphenol A type epoxy resin again, adding dibutyltin didodecyl sulfide, uniformly mixing, heating to 80 ℃, stirring for 4 hours, and cooling to room temperature to obtain a second epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the dibutyltin bis (dodecyl sulfur) is 1: 0.05;

s3, mixing the first epoxy resin mixture with the second epoxy resin mixture, adding polymethylphenylsiloxane, stirring and mixing uniformly, and removing absolute ethyl alcohol to obtain silane-terminated polyether modified epoxy resin;

wherein the mass ratio of the first epoxy resin mixture to the second epoxy resin mixture is 1: 0.6.

The preparation method of the terephthalic acid ester coated scandium silicate/yttrium silicate microspheres comprises the following steps:

(1) preparing nano scandium silicate/yttrium silicate:

s1, weighing ethyl orthosilicate, mixing the ethyl orthosilicate with an ethanol solution, uniformly dispersing, dropwise adding a mixed solution of scandium chloride and yttrium chloride while stirring, and continuously stirring for 10 hours after dropwise adding is finished to obtain a scandium silicate/yttrium silicate precursor;

wherein the mass fraction of the ethanol solution is 55%; the mixed solution of scandium chloride and yttrium chloride is obtained by mixing scandium chloride, yttrium chloride and deionized water according to the mass ratio of 1:0.36: 6; the mass ratio of the ethyl orthosilicate and the ethanol solution to the mixed solution of the scandium chloride and the yttrium chloride is 1:1.6: 4.8;

s2, carrying out reduced pressure drying on the scandium silicate/yttrium silicate precursor, then placing the scandium silicate/yttrium silicate precursor in a reaction furnace, heating to 1000 ℃, carrying out heat preservation treatment for 3 hours, then heating to 1400 ℃, carrying out heat preservation treatment for 4 hours, naturally cooling to room temperature, and carrying out ball milling to obtain nano scandium silicate/yttrium silicate with the particle size of 300-600 nm;

(2) hydroxylated scandium silicate/yttrium silicate:

weighing 3- [ bis (2-hydroxyethyl) amino ] propane triethoxysilane, mixing with deionized water, dispersing uniformly, adding nano scandium silicate/yttrium silicate, heating to 65 ℃, stirring for 10h, centrifuging, washing the obtained lower layer solid with pure water for three times, and drying under reduced pressure to obtain hydroxylated scandium silicate/yttrium silicate;

wherein the mass ratio of the nano scandium silicate/yttrium silicate to the aminopropyl triethoxysilane to the deionized water is 1:0.3: 8;

(3) preparing terephthalate-coated scandium silicate/yttrium silicate microspheres:

dispersing hydroxylated scandium silicate/yttrium silicate into N, N-dimethylformamide, adding terephthalic acid and phosphotungstic acid, heating to 140 ℃, stirring for 6 hours, filtering, washing and drying obtained filter residues to obtain terephthalic acid ester coated scandium silicate/yttrium silicate microspheres;

wherein the mass ratio of the hydroxylated scandium silicate to the yttrium silicate to the terephthalic acid to the phosphotungstic acid to the N, N-dimethylformamide is 1:0.65:0.06: 10.

The preparation method of the cast inorganic mineral insulated bus comprises the following steps:

step 1, weighing silane-terminated polyether modified epoxy resin according to parts by weight, mixing the silane-terminated polyether modified epoxy resin with polyethylene glycol, uniformly dispersing, adding terephthalate coated scandium silicate/yttrium silicate microspheres, heating to 60 ℃, stirring and mixing for 1 hour, and cooling to room temperature to obtain a first mixed material;

step 2, weighing quartz sand, aluminum oxide and neodymium oxide according to the weight parts, mixing the quartz sand, the aluminum oxide and the neodymium oxide into the first mixed material, stirring and mixing the mixture uniformly, then adding the phenyl phosphate and the dibenzyl phosphite which are weighed according to the weight parts, and mixing the mixture uniformly again to obtain a second mixed material;

step 3, weighing N, N-diethyl-1, 3-propane diamine according to the weight parts, adding the N, N-diethyl-1, 3-propane diamine into the second mixed material, and fully mixing to obtain an epoxy resin casting mixed material;

step 4, taking the bus cleaned by ethanol or acetone, placing the bus into a casting mold, coating a release agent in the casting mold, then placing the bus, and injecting the epoxy resin casting mixture into the casting mold to enable the epoxy resin casting mixture to completely wrap the bus;

and 5, placing the casting mold filled with the bus and the epoxy resin casting mixture into a reaction furnace, heating to 120 ℃, carrying out heat preservation treatment for 3 hours, heating to 150 ℃, carrying out heat preservation treatment for 2 hours, and demolding to obtain the cast inorganic mineral insulated bus.

Comparative example 1

An inorganic mineral insulating layer was prepared in the same manner as in example 1 except that:

the inorganic mineral insulating layer comprises the following components in parts by weight:

52 parts of silane-terminated polyether modified epoxy resin, 18 parts of dimethyl terephthalate, 17 parts of quartz sand, 15 parts of alumina, 7 parts of neodymium oxide, 4 parts of polyethylene glycol, 3 parts of alkyl phosphate, 0.5 part of diphenyl phosphorus oxide and 30 parts of N, N-diethyl-1, 3-propane diamine.

Comparative example 2

An inorganic mineral insulating layer was prepared in the same manner as in example 1 except that:

the inorganic mineral insulating layer comprises the following components in parts by weight:

52 parts of polyether modified epoxy resin (the preparation method refers to CN201510412424.3), 18 parts of dimethyl terephthalate, 17 parts of quartz sand, 15 parts of alumina, 7 parts of neodymium oxide, 4 parts of polyethylene glycol, 3 parts of alkyl phosphate, 0.5 part of diphenyl phosphorus oxide and 30 parts of N, N-diethyl-1, 3-propane diamine.

In order to more clearly illustrate the invention, the inorganic mineral insulating layers prepared in the examples 1 to 3 and the comparative examples 1 to 2 of the invention are compared in performance detection, the tensile strength is detected according to the standard ASTM D638-2014, and the impact strength is detected according to the standard GB/T1843-2008; the high temperature resistance is that after the constant temperature treatment is carried out for 1h at the temperature of 250 ℃, the surface discoloration condition is observed; and the acid corrosion resistance is detected for 120h by placing in a 10% sulfuric acid solution, and the alkali corrosion resistance is detected for 120h by placing in a 10% sodium hydroxide solution, and whether the surface is corroded is observed. The results are shown in table 1 below:

TABLE 1 comparison of the Properties of different inorganic mineral insulating layers

	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						Compressive strength (MPa)	112	107	115	93	78
Impact Strength (MPa)	31.8	30.5	32.6	25.8	20.2
						High temperature resistance	No color change	No color change	No color change	Slight discoloration	Severe discoloration
Dielectric constant	7.12	6.98	7.10	6.77	6.51
						Resistance to acid corrosion	No abnormal phenomenon	No abnormal phenomenon	No abnormal phenomenon	About 10% corrosion	About 20% corrosion
Resistance to alkali corrosion	No abnormal phenomenon	No abnormal phenomenon	No abnormal phenomenon	No abnormal phenomenon	About 10% corrosion

As can be seen from table 1 above, the inorganic mineral insulating layers prepared in embodiments 1 to 3 of the present invention have better mechanical strength (higher compressive strength and impact strength), high temperature resistance, insulating property (high dielectric constant), and acid-base corrosion resistance.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims (10)

1. A cast inorganic mineral insulated bus is characterized by comprising a bus body and an inorganic mineral insulating layer arranged on the surface of the bus body; the inorganic mineral insulating layer comprises the following components in parts by weight:

48-56 parts of silane-terminated polyether modified epoxy resin, 16-22 parts of terephthalate-coated scandium silicate/yttrium silicate microspheres, 15-20 parts of quartz sand, 12-18 parts of aluminum oxide, 5-10 parts of neodymium oxide, 2-6 parts of a dispersing agent, 2-5 parts of a flame retardant, 0.5-1 part of an antioxidant and 20-38 parts of a curing agent.

2. The poured inorganic mineral insulated bus bar of claim 1, wherein the inorganic mineral insulation layer has a thickness of 25 to 35 mm.

3. The cast inorganic mineral insulated bus of claim 1, wherein the silane terminated polyether modified epoxy resin is prepared by the following steps:

s1, weighing bisphenol A type epoxy resin and silane terminated polyether, mixing the bisphenol A type epoxy resin and the silane terminated polyether into absolute ethyl alcohol, uniformly mixing, heating to 65-80 ℃, performing reflux treatment for 1-2 hours, and cooling to room temperature to obtain a first epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the silane-terminated polyether to the absolute ethyl alcohol is 1: 0.8-1.2: 3-6;

s2, weighing bisphenol A type epoxy resin again, adding an organic tin catalyst, uniformly mixing, heating to 65-80 ℃, stirring for 2-4 hours, and cooling to room temperature to obtain a second epoxy resin mixture;

wherein the mass ratio of the bisphenol A epoxy resin to the organotin catalyst is 1: 0.02-0.05;

s3, mixing the first epoxy resin mixture with the second epoxy resin mixture, adding polymethylphenylsiloxane, stirring and mixing uniformly, and removing absolute ethyl alcohol to obtain silane-terminated polyether modified epoxy resin;

wherein the mass ratio of the first epoxy resin mixture to the second epoxy resin mixture is 1: 0.4-0.6.

4. The poured inorganic mineral insulated bus bar of claim 3, wherein the molecular weight of the silane terminated polyether is 10000-20000.

5. The poured inorganic mineral insulated bus of claim 1, wherein the preparation method of the terephthalate-coated scandium silicate/yttrium silicate microspheres comprises:

(1) preparing nano scandium silicate/yttrium silicate:

s1, weighing ethyl orthosilicate, mixing the ethyl orthosilicate with an ethanol solution, uniformly dispersing, dropwise adding a mixed solution of scandium chloride and yttrium chloride while stirring, and continuously stirring for 6-10 hours after dropwise adding is finished to obtain a scandium silicate/yttrium silicate precursor;

wherein the mass fraction of the ethanol solution is 35-55%; the mixed solution of scandium chloride and yttrium chloride is obtained by mixing scandium chloride, yttrium chloride and deionized water according to the mass ratio of 1: 0.23-0.36: 4-6; the mass ratio of the ethyl orthosilicate and the ethanol solution to the mixed solution of scandium chloride and yttrium chloride is 1: 1.2-1.6: 2.5-4.8;

s2, carrying out reduced pressure drying on the scandium silicate/yttrium silicate precursor, then placing the scandium silicate/yttrium silicate precursor in a reaction furnace, heating to 900-1000 ℃, carrying out heat preservation treatment for 1-3 h, then heating to 1250-1400 ℃ again, carrying out heat preservation treatment for 2-4 h, naturally cooling to room temperature, and carrying out ball milling to obtain nano scandium silicate/yttrium silicate;

(2) hydroxylated scandium silicate/yttrium silicate:

weighing 3- [ bis (2-hydroxyethyl) amino ] propane triethoxysilane, mixing with deionized water, dispersing uniformly, adding nano scandium silicate/yttrium silicate, heating to 55-65 ℃, stirring for 5-10 h, centrifuging, washing the obtained lower-layer solid with pure water for three times, and drying under reduced pressure to obtain hydroxylated scandium silicate/yttrium silicate;

wherein the mass ratio of the nano scandium silicate/yttrium silicate, aminopropyl triethoxysilane to deionized water is 1: 0.1-0.3: 5-8;

(3) preparing terephthalate-coated scandium silicate/yttrium silicate microspheres:

dispersing hydroxylated scandium silicate/yttrium silicate into N, N-dimethylformamide, adding terephthalic acid and phosphotungstic acid, heating to 120-140 ℃, stirring for 4-6 hours, filtering, washing and drying obtained filter residues to obtain terephthalic acid ester coated scandium silicate/yttrium silicate microspheres;

wherein the mass ratio of the hydroxylated scandium silicate to the yttrium silicate to the terephthalic acid to the phosphotungstic acid to the N, N-dimethylformamide is 1: 0.53-0.65: 0.03-0.06: 5-10.

6. The poured inorganic mineral insulated bus according to claim 1, wherein the particle size of the nano scandium silicate/yttrium silicate is 300 to 600 nm; the particle size of the quartz sand is 10-100 mu m; the particle size of the alumina is 1-10 mu m; the particle size of the neodymium oxide is 100-500 nm.

7. The cast inorganic mineral insulated bus bar of claim 1, wherein the dispersant is polyethylene glycol.

8. The cast inorganic mineral insulated bus of claim 1, wherein the antioxidant is one of diphenylphosphine oxide, dimethyl phosphite, and dibenzyl phosphite.

9. The cast inorganic mineral insulated bus of claim 1, wherein the flame retardant is an organophosphate flame retardant comprising one or more of alkyl phosphates, condensed phosphates, and phenyl phosphates.

10. The cast inorganic mineral insulated bus bar of claim 1, wherein the cast inorganic mineral insulated bus bar is prepared by the following method:

step 1, weighing silane-terminated polyether modified epoxy resin according to parts by weight, mixing the silane-terminated polyether modified epoxy resin with a dispersing agent, uniformly dispersing, adding terephthalate coated scandium silicate/yttrium silicate microspheres, heating to 50-60 ℃, stirring and mixing for 0.5-1 h, and cooling to room temperature to obtain a first mixed material;

step 2, weighing quartz sand, aluminum oxide and neodymium oxide according to the weight parts, mixing the quartz sand, the aluminum oxide and the neodymium oxide into the first mixed material, stirring and mixing uniformly, then adding the flame retardant and the antioxidant which are weighed according to the weight parts, and mixing uniformly again to obtain a second mixed material;

step 3, weighing a curing agent according to the weight parts, adding the curing agent into the second mixed material, and fully mixing to obtain an epoxy resin casting mixed material;

step 4, cleaning the bus, placing the bus in a casting mold, and injecting the epoxy resin casting mixture into the casting mold to enable the epoxy resin casting mixture to completely wrap the bus;

and 5, placing the casting mold filled with the bus and the epoxy resin casting mixture into a reaction furnace for curing, and demolding to obtain the cast inorganic mineral insulated bus.