CN114334459A - High-temperature-resistant ox horn-shaped aluminum electrolytic capacitor and preparation method thereof - Google Patents

Abstract

The invention discloses a high-temperature-resistant ox horn-shaped aluminum electrolytic capacitor and a preparation method thereof. A preparation method of a high-temperature-resistant cattle horn-shaped aluminum electrolytic capacitor comprises the following steps: (1) winding a core package, wherein the anode foil adopts a formed high-magnification aluminum foil; the electrolytic paper is manila fiber; (2) drying treatment; (3) impregnation with electrolyte: immersing the core cladding obtained in the step (2) into electrolyte for impregnation treatment, wherein the electrolyte comprises the following components in percentage: 50-65% of solvent, 25-38% of solute and 5-13% of additive; (4) heating for polymerization; (5) a packaging step, wherein the cover plate is prepared by laminating a lower-layer Teflon coating bakelite plate and an upper-layer ethylene propylene diene monomer plate in a composite manner; (6) and (5) an aging step. The invention effectively solves the problem that the prior ox horn-shaped aluminum electrolytic capacitor is easy to lose efficacy at the temperature of 130 ℃, thereby prolonging the service life of the product.

Description

High-temperature-resistant ox horn-shaped aluminum electrolytic capacitor and preparation method thereof

Technical Field

The invention relates to the technical field of capacitors, in particular to a high-temperature-resistant ox horn type aluminum electrolytic capacitor and a preparation method thereof.

Background

The existing market has more and more demands on high temperature resistance of the ox horn type aluminum electrolytic capacitor, and the ox horn type aluminum electrolytic capacitor material prepared by the prior art has overlarge internal pressure of the aluminum electrolytic capacitor and very easy failure of the product due to the fact that a large amount of gas is generated by volatilization of the substances when the material works at high temperature for a long time, and the leakage current of the product is increased.

The utility model discloses a novel high temperature resistant aluminum electrolytic capacitor, it includes sleeve pipe, aluminum hull and the electric capacity core of setting in the aluminum hull, the sleeve pipe is insulating cover of moulding of pyrocondensation PVC, the aluminum hull internal surface covers with electric capacity core contact surface has the heat-sink shell, the surface of aluminum hull and sleeve pipe contact surface cover have the heat conduction coating, dispel the heat to the electric capacity core through the combined action of heat conduction coating and heat-sink shell, prevent to melt under the high temperature or the heat concentration condition and lead to the electric capacity short circuit, when the condenser carries out the during operation under the environment that the temperature is too high, it is far away not enough only to dispel the heat through heat conduction coating and heat-sink shell, and the radiating efficiency is low, can make the heat of condenser be difficult to give off, causes the condenser inflation to swell, influences the service characteristic and the life of condenser.

Still like chinese patent and disclose a high temperature resistant aluminum electrolytic capacitor, including aluminum hull and the electric capacity core of setting in the aluminum hull, be formed with first airtight chamber and second airtight chamber on left side wall and the right side wall in the aluminum hull respectively, be provided with the coolant liquid in first airtight chamber and the second airtight chamber, the both sides of electric capacity core respectively with the outer surface contact in first airtight chamber and the second airtight chamber, the lower extreme of aluminum hull is connected with shock attenuation radiator unit. By adding a heat sink assembly, the economic cost to the user is also increased.

Disclosure of Invention

In order to make up for the defects of the prior art, the invention provides a high-temperature-resistant ox horn type aluminum electrolytic capacitor and a preparation method thereof.

The technical problem to be solved by the invention is realized by the following technical scheme:

in a first aspect, the invention provides a preparation method of a high-temperature-resistant ox horn type aluminum electrolytic capacitor, which comprises the following steps:

(1) winding a core package: interposing electrolytic paper between an anode foil and a cathode foil, and winding the anode foil and the cathode foil into a core package, wherein the anode foil is formed high-rate aluminum foil; the electrolytic paper is manila fiber;

(2) and (3) drying treatment: baking and drying the wound core package;

(3) impregnation with electrolyte: immersing the core cladding obtained in the step (2) into electrolyte for impregnation treatment, wherein the electrolyte comprises the following components in percentage: 50-65% of solvent, 25-38% of solute and 5-13% of additive;

wherein the solvent comprises the following components in percentage by weight: 45-60% of ethylene glycol, 12-20% of diethylene glycol, 8-15% of propylene glycol, 5-12% of polyethylene glycol and 2-8% of N-vinylpyrrolidone-pyrrolidone;

the solute comprises the following components in percentage by weight: 40-55% of ammonium sebacate, 18-30% of dodecanedioic acid, 10-17% of myristic acid, 5-8% of octadecenoic acid and 3-5% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 50-60% of mannitol, 25-35% of phosphoric acid, 8-12% of p-nitrophenol, 0.8-2.5% of m-nitroacetophenone, 0.5-2% of dihydroxybenzoic acid, 0.2-1% of isopropyl phosphate and 0.1-0.8% of a flash fire promoting agent;

(4) heating and polymerizing: heating and polymerizing the impregnated core bag;

(5) and (3) packaging: putting the core bag in the step (4) into a shell and sealing the shell by a cover plate; the cover plate is prepared by laminating a lower-layer Teflon coating bakelite plate and an upper-layer ethylene propylene diene monomer plate in a composite manner;

(6) and (5) an aging step.

As a preferred embodiment of the preparation method of the high temperature resistant ox horn type aluminum electrolytic capacitor provided by the invention, the anode foil is an aluminum foil formed by 1.6 times of working voltage. When the capacitor product discharges, the electric charge on one side of the anode foil can move to one side of the cathode foil, so that the cathode formation reaction is accelerated, and the heating is caused.

As a preferable embodiment of the preparation method of the high temperature resistant ox horn type aluminum electrolytic capacitor provided by the invention, in the step (2), the baking and drying are carried out by baking in an oven at 80-95 ℃ for 0.5-1.5 hours.

In a preferred embodiment of the method for manufacturing the high temperature resistant ox horn type aluminum electrolytic capacitor provided by the present invention, the impregnation treatment is a circulating type vacuum pumping and pressure impregnation.

In a preferred embodiment of the method for manufacturing the high temperature resistant ox horn type aluminum electrolytic capacitor according to the present invention, the impregnation treatment is a circulating type vacuum pumping, pressurizing, and atmospheric pressure impregnation.

As a preferred embodiment of the preparation method of the high-temperature-resistant ox horn-shaped aluminum electrolytic capacitor, the pressurizing pressure is controlled to be 180-220 Kpa, and the vacuum pressure is controlled to be-90-70 Kpa.

As a preferred embodiment of the preparation method of the high-temperature-resistant ox horn-shaped aluminum electrolytic capacitor provided by the invention, the cycle number is 1-5 times.

As a preferred embodiment of the preparation method of the high-temperature-resistant cattle horn-shaped aluminum electrolytic capacitor, in the heating polymerization step, the polymerization temperature is 50-65 ℃; the impregnation treatment time is 200 to 250 min.

In a second aspect, the invention also provides a high-temperature-resistant ox horn type aluminum electrolytic capacitor prepared by any one of the preparation methods.

In a third aspect, the invention also provides an electrolyte for a high-temperature resistant ox horn type aluminum electrolytic capacitor, which comprises the following components in percentage by weight: 50-65% of solvent, 25-38% of solute and 5-13% of additive;

wherein the solvent comprises the following components in percentage by weight: 45-60% of ethylene glycol, 12-20% of diethylene glycol, 8-15% of propylene glycol, 5-12% of polyethylene glycol and 2-8% of N-vinylpyrrolidone-pyrrolidone;

the solute comprises the following components in percentage by weight: 40-55% of ammonium sebacate, 18-30% of dodecanedioic acid, 10-17% of myristic acid, 5-8% of octadecenoic acid and 3-5% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 50-60% of mannitol, 25-35% of phosphoric acid, 8-12% of p-nitrophenol, 0.8-2.5% of m-nitroacetophenone, 0.5-2% of dihydroxybenzoic acid, 0.2-1% of isopropyl phosphate and 0.1-0.8% of a flash fire promoting agent.

The invention has the following beneficial effects:

in the existing ox horn type aluminum electrolytic capacitor, an aluminum foil oxide film in the product is damaged under the environment of high temperature of 130 ℃, so that leakage current rises, even exceeds a standard range, and the product fails in a short period. The invention selects the high-rate anode foil formed by chemical synthesis, reasonably selects manila fiber as electrolytic paper, adds additives in electrolyte and uses a cover plate made of specific materials, and the synergistic effect of the anode foil and the manila fiber can obviously improve the high-temperature resistance of the electrolytic capacitor, optimize the product characteristics, have good service life stability, have small capacity attenuation amplitude after 5000 hours of service life test at 130 ℃, have small DF amplification, effectively reduce leakage current, have normal appearance and do not generate bottom bulge, and effectively solve the problem that the existing ox horn-shaped aluminum electrolytic capacitor is easy to lose efficacy at 130 ℃, thereby prolonging the service life of the product.

Drawings

Fig. 1 is a schematic view of a cover plate foil strip dissected after a life test in example 1.

Fig. 2 is a schematic illustration of a cover plate foil strip dissected after a life test of comparative example 2.

Detailed Description

The present invention will be described in detail with reference to examples, which are only preferred embodiments of the present invention and are not intended to limit the present invention.

Example 1

A preparation method of a high-temperature-resistant cattle horn-shaped aluminum electrolytic capacitor comprises the following steps:

(1) winding a core package: interposing electrolytic paper between the anode foil and the cathode foil, and winding the anode foil and the cathode foil into a core package, wherein the anode foil is made of aluminum foil formed by 1.6 times of working voltage; the electrolytic paper is manila fiber;

(2) and (3) drying treatment: baking and drying the wound core package, namely baking the core package in an oven at 85 ℃ for 1 hour;

(3) impregnation with electrolyte: immersing the core cladding in the step (3) into electrolyte for impregnation treatment;

the electrolyte comprises the following components in percentage by weight: 60% of solvent, 35% of solute and 5% of additive;

wherein the solvent comprises the following components in percentage by weight: 60% of ethylene glycol, 12% of diethylene glycol, 8% of propylene glycol, 8% of polyethylene glycol and 12% of N-vinylpyrrolidone;

the solute comprises the following components in percentage by weight: 50% of ammonium sebacate, 25% of dodecanedioic acid, 15% of tetradecanoic acid, 7% of octadecenoic acid and 3% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 50% of mannitol, 35% of phosphoric acid, 12% of p-nitrophenol, 1% of m-nitroacetophenone, 0.5% of dihydroxybenzoic acid, 1% of isopropyl phosphate and 0.5% of flash fire promoting agent;

the impregnation treatment comprises circulating vacuum pumping and pressurized impregnation, wherein the pressurized pressure is controlled at 200Kpa, and the vacuum pressure is controlled at-80 Kpa; the circulating vacuumizing and pressurizing impregnation are carried out for 5 times;

(4) heating and polymerizing: heating and polymerizing the impregnated core bag; the polymerization temperature is 60 ℃; the impregnation treatment time is 240 min;

(5) and (3) packaging: putting the core bag in the step (4) into a shell and sealing the shell by a cover plate; the cover plate is prepared by laminating a lower-layer Teflon-coated bakelite plate and an upper-layer ethylene propylene diene monomer plate in a composite manner, and the lower-layer Teflon-coated bakelite plate is used as the inner side of the seal and is close to the core package;

(6) and (5) an aging step.

The capacitor prepared in example 1 was subjected to electrical property test and life test, specifically as follows:

example 2

The preparation method of example 2 is substantially the same as that of example 1 except that: the electrolyte comprises the following components in percentage by weight: 50% of solvent, 38% of solute and 12% of additive;

wherein the solvent comprises the following components in percentage by weight: 52% of ethylene glycol, 18% of diethylene glycol, 10% of propylene glycol, 5% of polyethylene glycol and 15% of N-vinyl pyrollidinone;

the solute comprises the following components in percentage by weight: 40% of ammonium sebacate, 30% of dodecanedioic acid, 17% of tetradecanoic acid, 8% of octadecenoic acid and 5% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 60% of mannitol, 25% of phosphoric acid, 11% of p-nitrophenol, 1.5% of m-nitroacetophenone, 2% of dihydroxybenzoic acid, 0.4% of isopropyl phosphate and 0.1% of flash fire promoting agent.

The capacitor obtained in example 2 was subjected to an electrical property test and a life test, specifically as follows:

example 3

The preparation method of example 3 is substantially the same as that of example 1 except that: the electrolyte consists of the following components in percentage by weight: 65% of solvent, 25% of solute and 10% of additive;

wherein the solvent comprises the following components in percentage by weight: 45% of ethylene glycol, 20% of diethylene glycol, 15% of propylene glycol, 12% of polyethylene glycol and 8% of N-vinyl pyrollidinone;

the solute comprises the following components in percentage by weight: 55% of ammonium sebacate, 24% of dodecanedioic acid, 12% of tetradecanoic acid, 5% of octadecenoic acid and 4% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 55% of mannitol, 30% of phosphoric acid, 10% of p-nitrophenol, 2.5% of m-nitroacetophenone, 0.8% of dihydroxybenzoic acid, 0.9% of isopropyl phosphate and 0.8% of flash fire promoting agent.

The capacitor obtained in example 3 was subjected to an electrical property test and a life test, specifically as follows:

comparative example 1

The preparation method of comparative example 1 is substantially the same as that of example 1 except that: the anode foil is an aluminum foil formed by 1 time of working voltage; the electrolytic paper is bast fiber.

The capacitor prepared in comparative example 1 was subjected to electrical property test and life test as follows:

comparative example 1: the anode foil is an aluminum foil formed by 1 time of working voltage, when a product discharges, the charge on one side of the anode foil can move to one side of the cathode foil, and the cathode formation reaction is accelerated to cause heating; the electrolytic paper is made of other plant fibers, the tear strength is not high, the burr resistance is not strong, the insulativity is not good, the service life stability of the electrolytic capacitor is not high, after 5000 hours of a service life test at 130 ℃, the capacity attenuation is obvious, the DF amplification is also large, and the appearance is slightly bulged.

Comparative example 2

The preparation method of comparative example 2 is substantially the same as that of example 1 except that: the cover plate is a lower bakelite plate and an upper ethylene propylene diene monomer composite cover plate.

The capacitor prepared in comparative example 2 was subjected to electrical property test and life test as follows:

comparative example 2: the lower bakelite plate and the upper ethylene propylene diene monomer composite cover plate are adopted, although the bakelite plate has the characteristics of no water absorption, no conductivity, high temperature resistance and high strength, in specific application, the high temperature resistance and unstable product life of a ox horn type aluminum electrolytic capacitor product are found, after a life test at 130 ℃ for 5000 hours, the capacity attenuation is obvious, the DF amplification is also large, a bottom drum appears in the appearance, yellow crystals are formed on dissected positive foil strips, and the positive foil strips are corroded, as shown in figure 2.

In the embodiment 1 of the invention, the cover plate consisting of the bakelite plate with the teflon coating at the upper layer and the ethylene propylene diene monomer at the lower layer is selected, wherein the bakelite plate with the teflon coating has the advantages of no water absorption, no generation of static electricity, strong high temperature resistance and wear resistance, and good high temperature resistance, corrosion resistance and sealing property of the product in specific application, and the service life of the product is prolonged, and the anatomical positive foil strip in the embodiment 1 is shown in fig. 1.

Comparative example 3

The preparation method of comparative example 3 is substantially the same as that of example 1 except that: the solvent comprises the following components in percentage by weight: 60% of ethylene glycol, 18% of diethylene glycol, 12% of propylene glycol and 10% of polyethylene glycol.

The capacitor prepared in comparative example 3 was subjected to electrical property test and life test as follows:

in comparative example 3, N-vinyl pyrollidinone is absent in the solvent, the ionic conductivity is not strong, the electrochemical performance of the capacitor cannot be improved, the temperature resistance is not strong at a high temperature of 130 ℃, after 5000 hours of a life test at a temperature of 130 ℃, the capacity attenuation is obvious, the DF amplification is large, and the appearance of the capacitor has bottom heave.

Comparative example 4

The preparation method of comparative example 4 is substantially the same as that of example 1 except that: the solute comprises the following components in percentage by weight: 50% of ammonium sebacate, 28% of dodecanedioic acid, 17% of tetradecanoic acid and 5% of ammonium pentaborate.

The capacitor prepared in comparative example 4 was subjected to electrical property test and life test as follows:

octadecenoic acid acts synergistically with N-vinylpyrrolidone in the solvent: can improve the high-temperature capability, improve the product stability and further improve the thermal stability of the material, when the solute of comparative example 4 lacks octadecenoic acid, the oxidability under high temperature can not be reduced, the product stability is not high, after 5000 hours of life test at 130 ℃, the capacity attenuation is more obvious, and the DF amplification is also large.

Comparative example 5

The preparation method of comparative example 5 is substantially the same as that of example 1 except that:

the additive comprises the following components in percentage by weight: 50% of mannitol, 35% of phosphoric acid, 13% of p-nitrophenol, 1% of m-nitroacetophenone, 0.5% of dihydroxybenzoic acid and 0.5% of flash fire promoting agent.

The capacitor prepared in comparative example 5 was subjected to electrical property test and life test as follows:

the additive of comparative example 5 is lack of isopropyl phosphate, can not inhibit the generation of hydrogen, can not reduce leakage current, can not effectively prevent the falling of an anode foil oxide film, and causes large leakage current of a product, and after 5000 hours of life test at 130 ℃, the capacity attenuation is obvious, the DF amplification is large, and the appearance is bottom-blown.

Comparative example 6

The preparation method of comparative example 6 is substantially the same as that of example 1 except that: the additive comprises the following components in percentage by weight: 50% of mannitol, 35% of phosphoric acid, 12.5% of p-nitrophenol, 1% of m-nitroacetophenone, 0.5% of dihydroxybenzoic acid and 1% of isopropyl phosphate.

The capacitor obtained in comparative example 6 was subjected to electrical property test and life test as follows:

the additive of comparative example 6 lacks of a flash promoting agent, is not easy to release oxygen, can not improve the strength of a dielectric film, can not ensure the flash voltage, has obvious capacity attenuation after 5000 hours of life test at 130 ℃, has large DF amplification and has bottom drum appearance.

The electrical properties of examples 1-3 and comparative examples 1-6 were compared together and are specified in the following table:

in the above table, each data is an average of 10 sample test data. And delta C/C is the capacitor capacity attenuation ratio after the life test, delta DF/DF is the capacitor DF amplification ratio after the life test, and delta LC/LC is the capacitor leakage current reduction ratio after the life test.

As can be seen from the above table, after 5000 hours of life test at 130 ℃, no matter the aluminum foil formed by 1-time working voltage is used as the anode foil and the electrolytic paper is made of other vegetable fibers in comparative example 1, or the conventional rubber in the industry is used as the cover plate in comparative example 2, or the N-vinylpyrrolidone is absent in the solvent in comparative example 3, or the octadecenoic acid is absent in the solute in comparative example 4, or the isopropyl phosphate is absent in the additive in comparative example 5 and the flash fire promoting agent is absent in the additive in comparative example 6, the defects of low life stability, obvious capacity attenuation, large DF amplification, large leakage current and bottom micro-drum appearance are caused, and the high-rate anode foil formed by the invention, the manila fiber reasonably used as the electrolytic paper, the additive added in the electrolyte and the cover plate made of the specific material are selected, the synergistic effect of the two can obviously improve the high temperature resistance of the electrolytic capacitor, optimize the product characteristics, and have good service life stability, after 5000 hours of life test at 130 ℃, the capacity attenuation amplitude is smaller, the DF amplification is small, the leakage current is effectively reduced, and the appearance is normal without bottom heave, thus effectively solving the problem that the existing ox horn type aluminum electrolytic capacitor is easy to lose efficacy at 130 ℃, and further prolonging the service life of the product.

The above-mentioned embodiments only express the embodiments of the present invention, and the description is more specific and detailed, but not understood as the limitation of the patent scope of the present invention, but all the technical solutions obtained by using the equivalent substitution or the equivalent transformation should fall within the protection scope of the present invention.

Claims (10)

1. A preparation method of a high-temperature-resistant ox horn type aluminum electrolytic capacitor is characterized by comprising the following steps:

(1) winding a core package: interposing electrolytic paper between an anode foil and a cathode foil, and winding the anode foil and the cathode foil into a core package, wherein the anode foil is formed high-rate aluminum foil; the electrolytic paper is manila fiber;

(2) and (3) drying treatment: baking and drying the wound core package;

(3) impregnation with electrolyte: immersing the core cladding obtained in the step (2) into electrolyte for impregnation treatment, wherein the electrolyte comprises the following components in percentage: 50-65% of solvent, 25-38% of solute and 5-13% of additive;

wherein the solvent comprises the following components in percentage by weight: 45-60% of ethylene glycol, 12-20% of diethylene glycol, 8-15% of propylene glycol, 5-12% of polyethylene glycol and 2-8% of N-vinylpyrrolidone-pyrrolidone;

the solute comprises the following components in percentage by weight: 40-55% of ammonium sebacate, 18-30% of dodecanedioic acid, 10-17% of myristic acid, 5-8% of octadecenoic acid and 3-5% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 50-60% of mannitol, 25-35% of phosphoric acid, 8-12% of p-nitrophenol, 0.8-2.5% of m-nitroacetophenone, 0.5-2% of dihydroxybenzoic acid, 0.2-1% of isopropyl phosphate and 0.1-0.8% of a flash fire promoting agent;

(4) heating and polymerizing: heating and polymerizing the impregnated core bag;

(5) and (3) packaging: putting the core bag in the step (4) into a shell and sealing the shell by a cover plate; the cover plate is prepared by laminating a lower-layer Teflon coating bakelite plate and an upper-layer ethylene propylene diene monomer plate in a composite manner;

(6) and (5) an aging step.

2. The method for preparing the high-temperature-resistant ox horn-type aluminum electrolytic capacitor as claimed in claim 1, wherein the anode foil is an aluminum foil formed by 1.6 times of working voltage.

3. The method for preparing the high temperature resistant ox horn type aluminum electrolytic capacitor as claimed in claim 1 or 2, wherein in the step (2), the baking and drying is to bake in an oven at 80 to 95 ℃ for 0.5 to 1.5 hours.

4. The method for manufacturing a high temperature resistant ox horn type aluminum electrolytic capacitor as claimed in claim 1, wherein the impregnation treatment is a circulating type vacuum pumping and pressure impregnation.

5. The method for manufacturing a high temperature resistant ox horn type aluminum electrolytic capacitor as claimed in claim 1, wherein the impregnation treatment is a circulating type vacuum pumping, pressurizing, normal pressure impregnation.

6. The method for preparing the high-temperature-resistant ox horn-shaped aluminum electrolytic capacitor as claimed in claim 4 or 5, wherein the pressurizing pressure is controlled to be 180-220 Kpa, and the vacuum pressure is controlled to be-90-70 Kpa.

7. The method for preparing the high-temperature-resistant ox horn-type aluminum electrolytic capacitor as claimed in claim 4 or 5, wherein the number of the cycles is 1-5.

8. The method for preparing the high-temperature-resistant ox horn type aluminum electrolytic capacitor as claimed in claim 1, wherein in the heating polymerization step, the polymerization temperature is 50-65 ℃; the impregnation treatment time is 200 to 250 min.

9. A high temperature resistant ox horn type aluminum electrolytic capacitor, characterized in that it is prepared by the method of any one of claims 1 to 9.

10. The electrolyte is used for a high-temperature-resistant ox horn-shaped aluminum electrolytic capacitor and is characterized by comprising the following components in percentage: 50-65% of solvent, 25-38% of solute and 5-13% of additive;

wherein the solvent comprises the following components in percentage by weight: 45-60% of ethylene glycol, 12-20% of diethylene glycol, 8-15% of propylene glycol, 5-12% of polyethylene glycol and 2-8% of N-vinylpyrrolidone-pyrrolidone;

the solute comprises the following components in percentage by weight: 40-55% of ammonium sebacate, 18-30% of dodecanedioic acid, 10-17% of myristic acid, 5-8% of octadecenoic acid and 3-5% of ammonium pentaborate;

the additive comprises the following components in percentage by weight: 50-60% of mannitol, 25-35% of phosphoric acid, 8-12% of p-nitrophenol, 0.8-2.5% of m-nitroacetophenone, 0.5-2% of dihydroxybenzoic acid, 0.2-1% of isopropyl phosphate and 0.1-0.8% of a flash fire promoting agent.

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