WO2021196437A1

WO2021196437A1 - Ultrahigh-voltage flame-retardant insulation powder for outdoor bus bar, and preparation method therefor

Info

Publication number: WO2021196437A1
Application number: PCT/CN2020/099911
Authority: WO
Inventors: 郭剑桥; 虞宁; 虞金卫
Original assignee: 江苏江南绝缘粉末有限公司
Priority date: 2020-04-01
Filing date: 2020-07-02
Publication date: 2021-10-07
Also published as: CN111187560B; CN111187560A

Abstract

Disclosed is an ultrahigh-voltage flame-retardant insulation powder for an outdoor bus bar. The raw materials thereof include the following components by weight: 10-15% of resin A, 10-15% of epoxy resin B, 25-30% of resin C, 15-20% of a curing agent, 10-20% of a filler, 5-10% of a flame retardant, and 1-3% of an auxiliary, with the total weight of these components being 100%, wherein resin A is an amidopolysiloxane-modified epoxy resin; resin B has an epoxide equivalent in the range of 1700-2000 g/eg and a softening point in the range of 85-95°C; resin C is a dipentene-modified polyester resin; and the auxiliary is a mixture of a compatibilizer, an accelerator, a leveling agent, an antioxidant, an anti-foaming agent and a pigment. A method for preparing the insulation powder comprises sequential and consecutive stepwise pre-dispersion and melt extrusion processes.

Description

Ultra-high voltage flame-retardant insulating powder for outdoor busbars and preparation method thereof

Technical field

The invention relates to an ultra-high voltage flame-retardant insulating powder for outdoor busbars and a preparation method thereof, and belongs to the field of functional powder coatings.

Background technique

Outdoor busbars and lightning rod insulators often face extremely harsh operating environments, as well as the risk of instantaneous high-voltage breakdown, which places extremely high requirements on the coating on the substrate. The existing powder coating products are divided into two major categories. One is decorative powder coatings, whose electrical insulation performance is not the primary consideration, and the other is epoxy insulating powder coatings, which have poor outdoor weather resistance and face thunder and lightning. This kind of instantaneous ultra-high pressure is of no avail. Regardless of decorative powder coatings or epoxy insulating powder coatings, the high temperature brought by instantaneous ultra-high pressure will reach the ignition point of the matrix resin. These stringent standards greatly limit the application of powder coatings in these fields. . Therefore, it is of great significance to prepare an insulating powder coating that can simultaneously satisfy super weather resistance, high electrical insulation, and high flame retardancy.

Summary of the invention

The purpose of the present invention is to provide an ultra-high voltage flame-retardant insulating powder for outdoor busbars. The ultra-high voltage field of the national grid refers to 275KV～800KV. In this voltage range, the insulating powder is required to have ultra-weather resistance and high resistance that existing powder coatings do not have. Pressure rating, and high flame retardancy. The invention fundamentally solves the problem that insulating powder cannot be used in harsh environments, which will greatly broaden the application field of insulating powder coatings, replace thermoplastic sleeves in the national grid transformation plan, and replace paint in the field of military electronics. Bring a brand-new technical solution to the special field. Another object of the present invention is to provide a method for preparing ultra-high voltage flame-retardant insulating powder for outdoor busbars.

In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

An ultra-high voltage flame-retardant insulating powder for outdoor busbars, the raw material of which includes the following weight components:

Resin A: 10%-15%;

Epoxy resin B: 10%-15%;

Resin C: 25%-30%;

Curing agent: 15%-20%;

Filling: 10%-20%;

Flame retardant: 5%-10%;

Additives: 1%-3%, the total weight of each component is 100%.

Preferably, the resin A is an aminopolysiloxane-modified epoxy resin, which utilizes the high and low temperature resistance, hydrophobicity, and weather resistance of the aminopolysiloxane. In the present invention, Combine it with epoxy resin B with high electrical insulation, and have complementary advantages. The epoxy equivalent range is 450-1700g/eg.

Preferably, the epoxy equivalent of the epoxy resin B is in the range of 1700-2000g/eg, and the softening point is in the range of 85-95°C. The epoxy resin B selected in the present invention has a low softening point and high epoxy equivalent. The combination of resin A and resin C realizes the high adhesion, high toughness and high strength performance of conventional epoxy resins at different times.

Preferably, the resin C is a dipentene modified polyester resin with an acid value of 30-40 mgKOH/g.

Preferably, the curing agent is a polyphenol grafted with N-alkylimidazole, and the hydroxyl equivalent is 320-440g/eg; N-alkylimidazole is a nitrogen-containing polycyclic curable epoxy resin, and the phenolic hydroxyl group can be combined with epoxy resin. The curing agent structure has multiple active groups to cross-link and cure the epoxy resin, which will greatly increase the cross-linking density of the insulating powder and fully improve the mechanical properties of the cured product. . In addition, the structure of the curing agent contains nitrogen elements, which act with combustibles to promote cross-linking into char during the combustion and decomposition process, reduce the temperature of combustibles, and do not produce combustible gas, which has a flame retardant effect.

Preferably, the filler is a mixture of silane-treated wollastonite powder and silane-treated silica micropowder, the compounding ratio is 2:1, and the mesh number is between 1000 mesh and 5000 mesh. The silane-treated wollastonite powder and silica micropowder of the present invention are all commercially available, and the combination fully exerts the weather resistance of the product itself, and synergizes with the flame retardant to increase the flame retardant effect, and synergizes with the resin to increase the compressive strength. In addition, the present invention uses silane-treated fillers. The difference between the filler and the untreated filler is the compatibility of the filler with the resin. After testing, the treated compatibility will be better, and the various properties of the finished product will be more fully utilized.

Preferably, the flame retardant is a mixture of phosphazene and phosphoric acid ester, with a compounding ratio of 1:1; in this solution, a compounded organic phosphorus flame retardant is selected and combined with compounded inorganic silicon fillers to form a composite flame retardant The system is flame retardant in all directions from the perspectives of carbon formation, oxygen isolation, heat insulation, and diluted oxygen concentration.

Preferably, the auxiliary agent is a mixture of a compatibilizer, an accelerator, a leveling agent, an antioxidant, and a defoamer.

The invention also discloses a preparation method of the insulating powder, which adopts the following steps in sequential order:

(1) Weigh the corresponding parts by weight of resin A, resin B, resin C, and compatibilizer and add them to a high-speed mixer, and stir at 800-900r/min for 10 minutes to make the resin particles evenly mixed;

(2) The mixture in step (1) is melted and extruded through a twin-screw, the temperature of the melting section is 100-110°C, the extrusion temperature of the die is 110-120°C, the tablet is compressed by a tablet machine, and the mixture is air-cooled and crushed.

(3) Put the fragments obtained in step (2) into the mixing tank, then add the corresponding amount of filler, stir for 5 minutes at 800~900r/min; then add flame retardant, curing agent and auxiliary agent to continue at 800~ Stir at 900r/min for 10min to make it fully mixed evenly;

(4) Melt and extrude the mixture in step (3) through a twin screw, the temperature of the melting section is 90-100°C, the extrusion temperature of the die is 100-110°C, and cooling water is passed through the screw. Tablet press, air cooling, crushing, air grading grinding granulation, sieving to obtain the finished powder.

In step (1) of the above feeding method, the three resins belong to different types. Although they have undergone modification treatment, their compatibility is still not as good as the same type. First, the three resins are pre-dispersed, and the compatibilizer is further added for compatibilization; (2) Melting and extruding the mixture of the three resins also further increases the compatibility of the three; this addition method is different from the traditional method of blending base materials and fillers regardless of order: one is to separate the base materials and fillers step by step Pre-dispersion, the second is to melt and extrude the base resin in the next step without participating in the reaction, which greatly increases the compatibility of different types of resins and ensures that the cross-linking reaction is structurally integrated.

The beneficial effects of adopting the technical solution of the present invention are:

The bright spot of the outdoor ultra-high-voltage flame-retardant insulating powder for outdoor use lies in the compound combination of three resins and the composite flame-retardant system formed by the flame retardant, curing agent and filler, so that the insulating powder obtains ultra-high flame-retardant performance. In addition, the insulating powder also has the advantages of super weather resistance, high insulation, etc., opening up a new application field of insulating powder; super weather resistance, acid and alkali resistance, solvent resistance under standard conditions without change for 1000h, calculated according to the UV aging cycle The service life is more than 30 years, ultra-high insulation, 0.1mm coating withstand voltage 10KV no breakdown, high flame resistance, 0.3mm test piece can pass UL-94 test V0 level, almost non-flammable, in addition, outdoor use ultra The preparation method of high-voltage flame-retardant insulating powder is simple and the process is stable. It is an ideal material in special fields.

Detailed ways

In order to further understand the present invention, the following is described in conjunction with specific embodiments, but the content of the embodiments is not limited.

In the present invention, the selected auxiliary agent is a mixture of compatibilizer, accelerator, leveling agent, antioxidant, defoamer and pigment. The available compatibilizers include maleic anhydride grafted epoxy and maleic anhydride grafted siloxane. Accelerators, leveling agents, antioxidants, defoamers and pigments are conventional choices in this field. The raw materials of the insulating powder are all commercially available.

The meshes of the filler wollastonite powder and silica micropowder selected in the present invention are 1000 meshes to 5000 meshes. In the present invention, it is preferably 2000 meshes. Other suitable meshes (for example, 1000 meshes, 3000 meshes, 4000 meshes, and 5000 meshes) fall into The scope of protection of the present invention.

Example 1

Resin A10%, resin B15%, resin C28%, curing agent 15.4%, silane-treated wollastonite powder and silane-treated silica powder 20% (compound weight ratio 2:1), phosphazene and phosphate ester mixture 10 % (Compound weight ratio 1:1), auxiliary agent 1.6%, of which the amount of compatibilizer accounts for 1% of the total weight of the raw materials.

Resin A is an amino polysiloxane modified epoxy resin with an epoxy equivalent in the range of 450-1700g/eg.

The epoxy equivalent of resin B ranges from 1700-2000g/eg, and the softening point ranges from 85-95°C.

Resin C is a dipentene modified polyester resin with an acid value of 30-40 mgKOH/g.

The curing agent is a polyphenol grafted with N-alkylimidazole, and the hydroxyl equivalent is 320-440g/eg.

Both wollastonite powder and silica powder are treated with silane, and the particle size is between 1000-5000 mesh.

The preparation method of the above-mentioned ultra-high voltage flame-retardant insulating powder for outdoor busbars includes the following steps of sequential connection:

(3) Put the fragments obtained in step (2) into the mixing tank, and then add the corresponding parts of silane-treated wollastonite powder and silica powder, stir at 800-900r/min for 5min; then add phosphazene and phosphoric acid The ester, curing agent, and auxiliary agent are continuously stirred at 800~900r/min for 10 minutes to make them fully mixed and uniform;

(4) Melt and extrude the mixture in step (3) through a twin screw, the temperature of the melting section is 90-100°C, the extrusion temperature of the die is 100-110°C, and cooling water is passed through the screw. Tablet press, air cooling, crushing, air graded milling, granulation, sieving, and finally magnetic separation to remove impurities to obtain finished powder; after testing, various indicators are listed in Table 1.

Example 2

The steps are the same as in Example 1, but the difference is that the composition weight of each raw material is resin A 15%, resin B 15%, resin C 28%, curing agent 20%, silane-treated wollastonite powder and silane-treated silica micropowder 13 % (Compound weight ratio 2:1), 7.4% phosphazene and phosphate ester mixture (compound weight ratio 1:1), auxiliary agent 1.6%, and the amount of compatibilizer accounts for 1% of the total weight of the raw materials.

The preparation method is the same as in Example 1.

After testing, the indicators are listed in Table 1.

Example 3

The steps are the same as in Example 1, but the difference is that the composition weight of each raw material is resin A 15%, resin B 15%, resin C 25%, curing agent (18.3%, silane-treated wollastonite powder and silane-treated silica micropowder) 20% (compound weight ratio 2:1), 5% phosphazene and phosphate ester mixture (compound weight ratio 1:1), auxiliary agent 1.7%, and the amount of compatibilizer accounts for 1% of the total weight of the raw materials.

The preparation method is the same as in Example 1.

After testing, the indicators are listed in Table 1.

Example 4

The same preparation method as in Example 1 is adopted, wherein the raw material weight composition includes: resin A 15%, resin B 10%, resin C 30%, curing agent 15%, silane-treated wollastonite powder and silane-treated silica fine powder 19% ( The compound weight ratio is 2:1), the phosphazene and phosphate ester mixture is 10% (the compound weight ratio is 1:1), and the auxiliary agent is 1%.

Example 5

Using the same preparation method as in Example 1, the weight composition of the raw materials includes: resin A 15%, resin B 15%, resin C 27%, curing agent 20%, silane-treated wollastonite powder and silane-treated silicon micropowder 10% ( The compound weight ratio is 2:1), the phosphazene and phosphate ester mixture is 10% (the compound weight ratio is 1:1), and the auxiliary agent is 3%.

Comparative example 1

The same raw material selection as in Example 1 was used, except that the curing agent was dicyandiamide. The composition of each raw material is resin A (domestic purchase) 12%, resin B (domestic purchase) 15%, resin C (commercially imported) 28%, curing agent 15%, silane treated wollastonite powder and silane treatment 17.3% of superfine silicon powder (compound weight ratio 2:1), phosphazene and phosphate ester mixture 10% (compound weight ratio 1:1), auxiliary 2.7%, the amount of compatibilizer accounts for the total weight of raw materials 2%.

The preparation method is the same as in Example 1.

After testing, the indicators are listed in Table 1.

Comparative example 2

The same raw material selection as in Example 1 was used, except that the filler component was replaced with calcium carbonate. The composition of each raw material is resin A12%, resin B12%, resin C27.3%, curing agent 18%, calcium carbonate 18%, phosphazene and phosphate ester mixture 10% (compound weight ratio 1:1), auxiliary The amount of compatibilizer is 2.7%, and the amount of compatibilizer accounts for 2% of the total weight of the raw materials.

The preparation method is the same as in Example 1.

After testing, the indicators are listed in Table 1.

Comparative example 3

The same raw material selection as in Example 1 was used, with the difference that the filler component was replaced with a mixture of untreated wollastonite powder and silica fine powder. The composition weight of each raw material is resin A 10%, resin B 15%, resin C 30%, curing agent 20%, wollastonite powder and silica powder 13.4% (compound weight ratio 2:1), phosphazene and phosphate ester mixture 10% (Compound weight ratio 1:1), auxiliary agent 1.6%, the amount of compatibilizer accounts for 1% of the total weight of raw materials.

The preparation method is the same as in Example 1.

After testing, the indicators are listed in Table 1.

Table 1

Taking the above-mentioned ideal embodiment according to the present invention as enlightenment, through the above-mentioned description content, relevant staff can make various changes and modifications without departing from the scope of the technical idea of the present invention. The technical scope of the present invention is not limited to the content of the description, and the technical scope must be determined according to the scope of the claims.

Claims

An ultra-high voltage flame-retardant insulating powder for outdoor busbars, which is characterized in that its raw materials include the following weight components:

Resin A: 10%-15%;

Epoxy resin B: 10%-15%;

Resin C: 25%-30%;

Curing agent: 15%-20%;

Filling: 10%-20%;

Flame retardant: 5%-10%;

Additives: 1%-3%; the total weight of the above components is 100%;

The resin A is an amino polysiloxane modified epoxy resin;

The epoxy equivalent of the resin B is in the range of 1700-2000g/eg, and the softening point is in the range of 85-95°C;

The resin C is a dipentene modified polyester resin;

The auxiliary agent is a mixture of compatibilizer, accelerator, leveling agent, antioxidant, defoamer and pigment.
The ultra-high voltage flame-retardant insulating powder for outdoor busbars according to claim 1, wherein the epoxy equivalent of the resin A ranges from 450 to 1700 g/eg.
The ultra-high voltage flame-retardant insulating powder for outdoor busbars according to claim 1, wherein the acid value of the resin C is 30-40 mgKOH/g.
The ultra-high voltage flame-retardant insulating powder for outdoor busbars according to claim 1, wherein the curing agent is selected from polyphenol grafted with N-alkylimidazole, and the hydroxyl equivalent is 320-440g/eg.
The ultra-high voltage flame-retardant insulating powder for outdoor busbars according to claim 1, characterized in that: the filler is a mixture of silane-treated wollastonite powder and silane-treated silica fine powder, with a compound weight ratio of 2 :1, the mesh number is between 1000 mesh and 5000 mesh.
The ultra-high-voltage flame-retardant insulating powder for outdoor busbars according to claim 1, wherein the flame retardant is a mixture of phosphazene and phosphoric acid ester, and the compounding weight ratio is 1:1.
A method for preparing insulating powder according to any one of claims 1-6, characterized in that the following steps are adopted in sequential order:

(1) Weigh the corresponding parts by weight of resin A, resin B, resin C, and compatibilizer and add them to a high-speed mixer, and stir at 800-900r/min for 10 minutes to make the resin particles evenly mixed;

(2) Melt and extrude the mixture in step (1) through a twin-screw, the temperature of the melting section is 100-110°C, the extrusion temperature of the die is 110-120°C, the tablet press is compressed, air-cooled, and crushed;

(3) Put the fragments obtained in step (2) into the mixing tank, and then add the corresponding amount of filler, stir for 5 minutes at 800~900r/min; then add curing agent, flame retardant and auxiliary agent to continue at 800~ Stir at 900r/min for 10min to make it fully mixed evenly;

(4) Melt and extrude the mixture in step (3) through twin screws, the temperature of the melting section is 90-100°C, the extrusion temperature of the die is 100-110°C, cooling water is passed through the screw; , Crushing, air graded grinding granulation, sieving to obtain the finished powder.