Resistor disc and preparation method thereof, and lightning arrester

Abstract

The invention provides a resistor disc and a preparation method thereof, and a lightning arrester. The preparation method provided by the invention comprises the following steps: A) mixing and grinding a ceramic raw material, water and an adhesive to obtain a ceramic insulating coating; wherein the ceramic raw material comprises the following components in percentage by mass: 70-90% of zinc oxide; 2%-4% of bismuth oxide; 4%-15% of antimony oxide; 3%-8% of an insulating filler; b) coating the ceramic insulating paint on the side surface of the resistor disc; and C) co-firing the resistor disc with the ceramic insulating coating obtained in the step B) to obtain the resistor disc. According to the preparation method disclosed by the invention, the insulativity and weather resistance of the resistor disc are improved, the preparation process is simplified, the production cycle and energy consumption are reduced, the production efficiency is favorably improved, and the adopted raw materials are environment-friendly and accord with the requirement of the current society on environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of lightning arresters, and in particular to a resistor and a preparation method thereof, and a lightning arrester. Background Art

[0002] In the power system, the lightning arrester is an important overvoltage protection device. Its main function is to discharge the energy of overvoltage into the ground by discharging when overvoltage occurs on the line, thereby protecting other equipment in the power system from damage. The core component of the lightning arrester is the resistor, and its performance directly affects the protection effect of the lightning arrester. In the manufacturing process of the resistor, it is necessary to apply a layer of insulating coating on its surface to ensure the electrical performance and mechanical strength of the resistor. Traditional resistor insulation coatings are mainly organic insulating paint or glass glaze, but these materials have poor insulation performance and weather resistance, and the preparation process is complicated and energy consumption is high.

[0003] In order to solve the above problems, the existing solutions in the prior art are mainly to coat the surface of the resistor with organic insulating paint and solidify it or to coat it with glass glaze and heat it after the resistor is sintered. This method can improve the insulation performance and weather resistance of the resistor, but its preparation process is complicated and energy consumption is high, and the organic insulating paint and glass glaze have certain pollution to the environment during preparation and use.

[0004] Although the existing technology has solved the insulation problem of resistors to a certain extent, there are still some problems and shortcomings in practical applications. First, the insulation performance and weather resistance of existing insulating coating materials (such as organic insulating varnish) are poor, which will affect the service life and stability of the resistor. Secondly, the existing preparation method is complicated and energy-consuming, which not only increases the production cost, but also does not conform to the concept of energy conservation and emission reduction advocated by the current society. Therefore, how to simplify the preparation process, reduce energy consumption, and reduce environmental pollution while ensuring the insulation performance of the resistor is an urgent problem to be solved in the current resistor manufacturing field. Summary of the invention

[0005] In view of this, the present invention provides a resistor and a preparation method thereof, as well as a lightning arrester. The preparation method of the present invention not only improves the insulation and weather resistance of the resistor, but also simplifies the preparation process, reduces the production cycle and energy consumption, improves production efficiency, and uses environmentally friendly raw materials, which meets the current social requirements for environmental protection.

[0006] The present invention provides a method for preparing a resistor, comprising the following steps:

[0007] A) mixing and grinding ceramic raw materials, water and a binder to obtain a ceramic insulating coating;

[0008] in,

[0009] In terms of mass percentage, the ceramic raw material comprises:

[0010] Zinc oxide: 70% to 90%;

[0011] Bismuth oxide: 2% to 4%;

[0012] Antimony oxide: 4% to 15%;

[0013] Insulation filler: 3% to 8%;

[0014] B) applying the ceramic insulating coating to the side of the resistor;

[0015] C) co-firing the resistor with the ceramic insulating coating obtained in step B) to obtain a resistor.

[0016] Preferably, the insulating filler is at least one of chromium oxide, yttrium oxide and lithium carbonate.

[0017] Preferably, the binder is polyethylene glycol.

[0018] Preferably, the adhesive is PEG20000.

[0019] Preferably, in step A), the amount of the binder used is 4% to 8% of the mass of the ceramic raw material.

[0020] Preferably, in step A), the amount of water used is 30% to 60% of the mass of the ceramic raw material, and the solid content of the obtained ceramic insulating coating is 40% to 70%.

[0021] Preferably, in step B), the coating amount is 2 to 10 g / cm 2 .

[0022] Preferably, in step C), the co-firing temperature is 1000-1150° C. and the time is 2-6 hours.

[0023] The present invention also provides a resistor sheet produced by the production method described in the above technical solution.

[0024] The present invention also provides a lightning arrester, wherein the resistor is the resistor described in the above technical solution.

[0025] The present invention provides a method for preparing a resistor, wherein ZnO powder is used as the main raw material, ZnO+Bi2O3+Sb2O3 is used as the basic system, specific additives with insulating properties are added in a certain proportion, water and a binder are added, and then the mixture is mixed evenly by a stirring ball mill. The mixed slurry is evenly coated on the side of an unsintered resistor blank, and sintered together with the resistor at a high temperature, and after sintering, a firm ceramic insulating coating is formed on the side of the resistor. The method of the present invention not only improves the insulation performance and weather resistance of the resistor, but also simplifies the preparation process of the insulating coating and reduces energy consumption; in the process of preparing the ceramic insulating coating, the raw materials used are completely environmentally friendly, avoiding pollution to the environment during the preparation and use process, and the selection and preparation method of such environmentally friendly raw materials not only meet the current social requirements for environmental protection, but also reduce the production cost; by optimizing the production process of the resistor, the entire production cycle and energy consumption of the resistor are significantly reduced, and such optimization not only improves the production efficiency, but also reduces the production cost, and has a high economic value; in the process of co-firing the resistor green body and the ceramic insulating coating, appropriate sintering temperature and time are used to ensure the close combination of the ceramic insulating coating and the resistor green body, thereby improving the overall performance of the resistor. DETAILED DESCRIPTION

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0027] In this article, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0028] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0029] Herein, when it comes to numerical ranges, unless otherwise specified, the numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0030] In this article, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 200-1000rpm means that the units of the left endpoint "200" and the right endpoint "1000" are both rpm.

[0031] The present invention provides a method for preparing a resistor, comprising the following steps:

[0032] A) mixing and grinding ceramic raw materials, water and a binder to obtain a ceramic insulating coating;

[0033] in,

[0034] In terms of mass percentage, the ceramic raw material comprises:

[0035] Zinc oxide: 70% to 90%;

[0036] Bismuth oxide: 2% to 4%;

[0037] Antimony oxide: 4% to 15%;

[0038] Insulation filler: 3% to 8%;

[0039] B) applying the ceramic insulating coating to the side of the resistor;

[0040] C) co-firing the resistor with the ceramic insulating coating obtained in step B) to obtain a resistor.

[0041] [About Step A]:

[0042] A) Ceramic raw materials, water and a binder are mixed and ground to obtain a ceramic insulating coating.

[0043] In the present invention, the ceramic raw material comprises, by mass percentage:

[0044] Zinc oxide: 70% to 90%;

[0045] Bismuth oxide: 2% to 4%;

[0046] Antimony oxide: 4% to 15%;

[0047] Insulating filler: 3%~8%.

[0048] in,

[0049] The zinc oxide content may specifically be 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90%.

[0050] The content of bismuth oxide can specifically be 2%, 3%, or 4%.

[0051] The content of antimony oxide can specifically be 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%.

[0052] The insulating filler is preferably at least one of chromium oxide, yttrium oxide and lithium carbonate. The content of the insulating filler can be 3%, 4%, 5%, 6%, 7% or 8%.

[0053] The total amount of the above four raw materials is preferably 100%.

[0054] In the present invention, the binder is preferably polyethylene glycol, more preferably PEG 20000. In the present invention, the amount of the binder is preferably 4% to 8% of the mass of the ceramic raw material, specifically 4%, 5%, 6%, 7%, 8%.

[0055] In the present invention, the amount of water is preferably 30% to 60% of the mass of the ceramic raw material, specifically 30%, 35%, 40%, 45%, 50%, 55%, 60%. In the present invention, the amount of water is also controlled so that the solid content of the obtained coating is 40% to 70%, specifically 40%, 45%, 50%, 55%, 60%, 65%, 70%.

[0056] In the present invention, the method of mixing and grinding ceramic raw materials, water and adhesive is preferably ball milling. The rotation speed of the ball mill is preferably 200-1000rpm, specifically 200rpm, 300rpm, 400rpm, 500rpm, 600rpm, 700rpm, 800rpm, 900rpm, 1000rpm. The time of the ball milling is preferably 2-5h, specifically 2h, 3h, 4h, 5h. The degree of the ball milling is preferably such that the fineness of the coating reaches 1.5-10μm, specifically 1.5μm, 2.0μm, 2.5μm, 3.0μm, 3.5μm, 4.0μm, 4.5μm, 5.0μm, 5.5μm, 6.0μm, 6.5μm, 7.0μm, 7.5μm, 8.0μm, 8.5μm, 9.0μm, 9.5μm, 10μm. After the above mixing and grinding, a ceramic insulating coating is obtained.

[0057] [About step B]:

[0058] B) coating the ceramic insulating coating on the side of the resistor.

[0059] In the present invention, the coating method of applying the ceramic insulating coating on the side of the resistor is preferably roller coating. The specific operation of the roller coating is as follows: pour the ceramic insulating coating into a roller coating machine, place the resistor on the roller coating machine, and evenly coat the ceramic insulating coating on the side of the resistor blank through the roller coating machine.

[0060] In the present invention, the resistor is an unsintered resistor. The type of the resistor is not particularly limited, and can be a conventional resistor in the art, such as a zinc oxide resistor.

[0061] In the present invention, the ceramic insulating coating is coated on the side of the resistor piece, and preferably the ceramic insulating coating is coated on both sides of the resistor piece.

[0062] In the present invention, when applying the ceramic insulating coating, the coating amount is preferably 2 to 10 g / cm 2 , specifically 2g / cm 2 , 3g / cm 2 , 4g / cm 2 , 5g / cm 2 , 6g / cm 2 , 7g / cm 2 , 8g / cm 2 , 9g / cm 2 、10g / cm 2 .

[0063] [About Step C]:

[0064] C) co-firing the resistor with the ceramic insulating coating obtained in step B) to obtain a resistor.

[0065] In the present invention, after the resistor with ceramic insulating coating is obtained in step B), it is placed in a kiln for co-firing. In the present invention, the co-firing temperature is preferably 1000-1150°C, specifically 1000°C, 1010°C, 1020°C, 1030°C, 1040°C, 1050°C, 1060°C, 1070°C, 1080°C, 1090°C, 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C. The co-firing insulation time is preferably 2-6h, specifically 2h, 3h, 4h, 5h, 6h. After the above co-firing, a firm ceramic insulating coating will be formed on the side of the resistor, and a resistor blank in which the ceramic insulating coating and the side of the resistor are fused together is obtained.

[0066] In the present invention, after the above co-firing, the following post-treatment is preferably further performed: end surface grinding, aluminum electrode spraying, so as to obtain a finished resistor chip.

[0067] The present invention also provides a resistor sheet produced by the production method described in the above technical solution.

[0068] The present invention also provides a lightning arrester, wherein the resistor is the resistor described in the above technical solution.

[0069] The present invention provides a method for preparing a resistor, wherein ZnO powder is used as the main raw material, ZnO+Bi2O3+Sb2O3 is used as the basic system, specific additives with insulating properties are added in a certain proportion, water and a binder are added, and then the mixture is mixed evenly by a stirring ball mill. The mixed slurry is evenly coated on the side of an unsintered resistor blank, and sintered together with the resistor at a high temperature, and after sintering, a firm ceramic insulating coating is formed on the side of the resistor. The method of the present invention not only improves the insulation performance and weather resistance of the resistor, but also simplifies the preparation process of the insulating coating and reduces energy consumption; in the process of preparing the ceramic insulating coating, the raw materials used are completely environmentally friendly, avoiding pollution to the environment during the preparation and use process, and the selection and preparation method of such environmentally friendly raw materials not only meet the current social requirements for environmental protection, but also reduce the production cost; by optimizing the production process of the resistor, the entire production cycle and energy consumption of the resistor are significantly reduced, and such optimization not only improves the production efficiency, but also reduces the production cost, and has a high economic value; in the process of co-firing the resistor green body and the ceramic insulating coating, appropriate sintering temperature and time are used to ensure the close combination of the ceramic insulating coating and the resistor green body, thereby improving the overall performance of the resistor.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] 1. Simplify the preparation process: The present invention adopts a method of co-firing the ceramic insulating coating and the resistor green body, which avoids the coating and curing process of the insulating coating after the resistor is sintered in the traditional technology, greatly simplifies the preparation process, and saves preparation time. 2. Reduce energy consumption: Since the preparation method of the present invention is simple, it avoids the complicated coating and curing process in the traditional technology, thereby reducing energy consumption, which is in line with the energy conservation and emission reduction concept advocated by the current society. 3. Improve insulation performance and weather resistance: The ceramic coating formed on the side of the resistor in the present invention has excellent insulation performance and weather resistance, which can effectively protect the resistor and improve its service life and stability. 4. Environmental protection: The raw materials used in the present invention are completely environmentally friendly, avoiding the pollution of the environment to the organic insulating paint and glass glaze used in the traditional technology during the preparation and use process, which is in line with the green environmental protection concept advocated by the current society. 5. Reduce production costs: Since the preparation method of the present invention is simple, energy consumption is low, and the raw materials are environmentally friendly, it can effectively reduce production costs and has high economic value.

[0072] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0073] Example 1

[0074] A) putting the ceramic raw material into a ball mill, adding the adhesive polyethylene glycol PEG20000 (the amount is 4% of the mass of the ceramic raw material) and a certain amount of water, and high-speed ball milling at 200 rpm for 5 hours, the grinding fineness is 1.5 μm, and a ceramic insulating coating is obtained with a solid content of 65%;

[0075] in,

[0076] In terms of mass percentage, the ceramic raw material comprises:

[0077] Zinc oxide: 77%;

[0078] Bismuth oxide: 2%;

[0079] Antimony oxide: 14%;

[0080] Insulating filler (chromium oxide): 7%.

[0081] B) Pour the ceramic insulating coating into the roller coating machine, place the unsintered ZnO resistor on the roller coating machine, and evenly coat the side of the resistor with the ceramic insulating coating at a coating amount of 3g / cm 2 .

[0082] C) The resistor with ceramic insulating coating obtained in step B) is placed in a kiln, fired at 1000° C. for 6 hours, and then subjected to end surface grinding and aluminum electrode spraying to obtain a finished resistor.

[0083] Example 2

[0084] A) putting the ceramic raw material into a ball mill, adding the adhesive polyethylene glycol PEG20000 (the amount is 6% of the mass of the ceramic raw material) and a certain amount of water, and high-speed ball milling at 600 rpm for 3 hours, the grinding fineness is 1.5 μm, and a ceramic insulating coating is obtained with a solid content of 65%;

[0085] in,

[0086] In terms of mass percentage, the ceramic raw material comprises:

[0087] Zinc oxide: 83%;

[0088] Bismuth oxide: 2%;

[0089] Antimony oxide: 8%;

[0090] Insulating filler (yttrium oxide): 7%.

[0091] B) Pour the ceramic insulating coating into the roller coating machine, place the unsintered ZnO resistor on the roller coating machine, and evenly coat the side of the resistor with the ceramic insulating coating at a coating amount of 3g / cm 2 .

[0092] C) The resistor with ceramic insulating coating obtained in step B) is placed in a kiln, fired at 1100° C. for 4 hours, and then subjected to end surface grinding and aluminum electrode spraying to obtain a finished resistor.

[0093] Example 3

[0094] A) putting the ceramic raw material into a ball mill, adding the adhesive polyethylene glycol PEG20000 (the amount is 8% of the mass of the ceramic raw material) and a certain amount of water, and high-speed ball milling at 1000 rpm for 2 hours, the grinding fineness is 1.5 μm, and a ceramic insulating coating is obtained with a solid content of 65%;

[0095] in,

[0096] In terms of mass percentage, the ceramic raw material comprises:

[0097] Zinc oxide: 85%;

[0098] Bismuth oxide: 3%;

[0099] Antimony oxide: 7%;

[0100] Insulating filler (lithium carbonate): 5%.

[0101] B) Pour the ceramic insulating coating into the roller coating machine, place the unsintered ZnO resistor on the roller coating machine, and evenly coat the side of the resistor with the ceramic insulating coating at a coating amount of 3g / cm 2 .

[0102] C) The resistor with ceramic insulating coating obtained in step B) is placed in a kiln, fired at 1150° C. for 2 hours, and then end-face ground and aluminum electrode sprayed to obtain a finished resistor.

[0103] Example 4

[0104] The method was implemented according to Example 3, except that the coating amount in step B) was 5 g / cm 2 .

[0105] Example 5

[0106] The method was implemented according to Example 3, except that the coating amount in step B) was 8 g / cm 2 .

[0107] Example 6

[0108] The process was carried out in accordance with Example 5, except that the solid content of the coating in step A) was 60%.

[0109] Performance Test:

[0110] The electrical insulation performance of the ZnO varistor sheets obtained in Examples 1 to 6 was tested, and the test results are shown in Table 1. (Note: The specifications and dimensions of the ZnO varistor sheets obtained in Examples 1 to 6 are The side area is 42.45cm 2 . )

[0111] Table 1: Properties of ZnO varistor sheets obtained in Examples 1 to 6

[0112]

[0113] Note: The coating weight test method is: use an electronic balance to weigh the weight of the resistor after coating - the weight of the resistor before coating. The coating thickness measurement method is: after grinding the end face of the sintered resistor, use a microscope to measure the coating thickness; the greater the coating weight, the thicker the coating thickness after co-firing, but the thicker the coating thickness, the greater the side insulation strength, but the thicker the better. Resistor potential gradient: resistor DC reference voltage (V) / resistor thickness (mm). Square wave capacity and high current impact tolerance test refer to GB / T 11032-2020 or IEC60099-4. Meeting the standard requirements means that the product quality meets the requirements.

[0114] It can be seen from the test results in Table 1 that the leakage current of the resistor obtained by the present invention is below 7μA, showing excellent insulation. At the same time, the pass rate of the square wave capacitance test is above 8 / 10 (i.e. 80%), and the pass rate of the large current impact tolerance is above 1 / 5 (i.e. 20%), which meets the electrical performance requirements. Among them, the insulation and tolerance of Examples 4-6 are further improved, and the comprehensive performance of Example 5 is the best.

[0115] The present invention provides a method for preparing a resistor. First, the present invention adopts the ceramic insulation co-firing technology on the side of the resistor, which can significantly improve the insulation performance and weather resistance of the resistor, thereby improving the protection effect of the arrester and meeting the high standard requirements of the power system for the arrester. Secondly, the preparation method of the present invention is simple and has low energy consumption, which can greatly reduce the production cost of the resistor and meet the market demand for high-efficiency and low-cost resistors. Finally, the raw materials of the present invention are completely environmentally friendly, and the preparation process is pollution-free to the environment, which meets the current social demand for green and environmentally friendly products. Therefore, the present invention has broad market application prospects and needs.

[0116] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for preparing a resistor, characterized in that: The following steps are involved: A) mixing and grinding ceramic raw materials, water and a binder to obtain a ceramic insulating coating; in, In terms of mass percentage, the ceramic raw material comprises: Zinc oxide: 70% to 90%; Bismuth oxide: 2% to 4%; Antimony oxide: 4% to 15%; Insulation filler: 3%~8%; B) applying the ceramic insulating coating to the side of the resistor; C) co-firing the resistor with the ceramic insulating coating obtained in step B) to obtain a resistor.

2. The preparation method according to claim 1, characterized in that: The insulating filler is at least one of chromium oxide, yttrium oxide and lithium carbonate.

3. The preparation method according to claim 1, characterized in that: The binder is polyethylene glycol.

4. The preparation method according to claim 1 or 3, characterized in that: The adhesive is PEG20000.

5. The preparation method according to claim 1, characterized in that: In step A), the amount of the binder is 4% to 8% of the mass of the ceramic raw material.

6. The preparation method according to claim 1, characterized in that: In step A), the amount of water used is 30% to 60% of the mass of the ceramic raw material, and the solid content of the obtained ceramic insulating coating is 40% to 70%.

7. The preparation method according to claim 1, characterized in that: In step B), the coating amount is 2 to 10 g / cm 2 .

8. The preparation method according to claim 1, characterized in that: In step C), the co-firing temperature is 1000-1150° C. and the time is 2-6 hours.

9. A resistor produced by the method according to any one of claims 1 to 8.

10. A lightning arrester, characterized in that: The resistor is the resistor described in claim 9.

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