CN116013696B - A method for suppressing nano-scale hydrogen-water magnetic suspension bubbles in preparing finished foil - Google Patents

本发明属于铝电解电容器技术领域，具体涉及一种制备成品箔的抑制纳米级氢水磁悬液泡方法，在进行发孔腐蚀步骤时，通过添加纳米级的钡铁氧体磁粉、有机消泡剂超声均匀后配置水溶液BFE，添加于槽液中，以磁粉驱动有机消泡剂以水为载体，抑制纳米级氢水磁悬液泡产生，通过抑制纳米级氢水液泡产生，降低支孔形成的概率，提升成品箔的容量与强度。

The invention belongs to the technical field of aluminum electrolytic capacitors, and particularly relates to a method for inhibiting nano-scale hydrogen-water magnetic suspension bubbles in preparing finished foils. When performing a pore corrosion step, nano-scale barium ferrite magnetic powder and an organic defoamer are added and ultrasonically uniformly prepared into an aqueous solution BFE, which is added into a tank liquid. The organic defoamer is driven by magnetic powder and uses water as a carrier to inhibit the generation of nano-scale hydrogen-water magnetic suspension bubbles. By inhibiting the generation of nano-scale hydrogen-water bubbles, the probability of branch hole formation is reduced, and the capacity and strength of the finished foil are improved.

Method for preparing finished foil by inhibiting nanoscale hydrogen-water magnetic suspension bubble

Technical Field

The invention belongs to the technical field of aluminum electrolytic capacitors, and particularly relates to a method for preparing a finished foil and inhibiting nanoscale hydrogen water magnetic suspension bubbles.

Background

The foil is an important raw material, and the motor corrosion process of the high-voltage aluminum foil in the prior art generally comprises the steps of pretreatment, primary pore-forming corrosion, secondary reaming corrosion, post-treatment and the like, and for an HCl-H ₂SO₄ system, the relative concentration of Cl ^- and SO ₄ ^2- on an electric double layer interface and the ion transfer efficiency of the aluminum foil in the pore-forming process can be obviously improved by adding a magnetic field outside a corrosion tank and controlling the eddy current effect in the tank liquid. Meanwhile, the externally-applied coupling magnetic field can inhibit overgrowth of an alumina layer, promote adsorption capacity of Cl ^- in an etching hole tunnel, promote effective corrosion and greatly promote uniformity of a residual core.

However, the technology has the following problems that a large amount of nanoscale hydrogen water magnetic suspension bubbles can be generated in the tank due to the magnetic eddy effect and cannot escape rapidly, the bubbles are blocked at the bottom of an etching hole to influence further hole generation, so that branch holes are generated in a tunnel to influence the capacity and strength of the finished foil. Thus, there remains a need for improvements in this technology.

Disclosure of Invention

The invention aims at the problems existing in the prior art and provides a method for preparing a finished foil by inhibiting nano-scale hydrogen water magnetic suspension bubbles.

The invention aims at realizing the following technical scheme that the method for preparing the finished foil for inhibiting the nano-scale hydrogen water magnetic suspension bubble comprises the following steps:

Step S1, soaking the original foil in a sodium hydroxide solution with the concentration of 0.2-4% at 70-80 ℃ for 1-2min, and washing with pure water;

Step S2, placing the original foil obtained in the step S1 in a pore-forming liquid, wherein the strength of the original foil is 0.02T-0.12T constant magnetic field strength, the original foil is subjected to pore-forming corrosion treatment for 3-5 times at intervals of 40-60S at constant current range of 0.20A/cm ^-2-0.25 A/cm^-2 constant current, and then the original foil is cleaned by pure water;

step S3, placing the porous foil obtained in the step S2 in reaming liquid, performing reaming corrosion treatment for 7-9 times at intervals of 20-30S at constant current of ^-2-0.18A/cm^-2 and current range of 0.16A/cm, and cleaning with pure water;

S4, placing the reaming foil obtained in the step S3 in an HCl solution for treatment, washing with pure water, placing in an HNO ₃ solution for treatment, and washing with pure water;

S5, placing the reaming foil obtained in the step S4 in an oven for heat treatment, and cooling to normal temperature;

Step S6, performing formation treatment on the reaming foil obtained in the step S5, and cleaning and drying to obtain a finished foil;

Wherein, in step S2, adding barium ferrite magnetic powder into the pore-forming liquid to drive aqueous solution BFE of organic defoamer taking water as carrier, wherein the organic defoamer is organic ethers or organic silicon.

Preferably, the preparation method of the aqueous solution BFE comprises the following steps of uniformly mixing 1-1.5g/L of 50-100nm barium ferrite magnetic powder, 2-5g/L of polyoxypropylene ether and water at normal temperature by ultrasonic waves to obtain the aqueous solution BFE.

Preferably, the thickness of the raw foil in step S1 is 125-135 μm.

Preferably, the pore-forming liquid in the step S2 is 3% -5% HCl, 30% -50% H ₂SO₄, 0.5% -3% Al, and 0.02% -0.05% aqueous solution BFE.

Preferably, in the step S2, the strength is 0.06T, and the pore-forming corrosion treatment is carried out 5 times every 60S time interval at a constant current density of 0.20A/cm ^-2.

Preferably, in the step S3, the pore-enlarging liquid is 3% -8% HNO ₃、0.07%- 0.14%H₃PO₄ and 0.02% -0.05% corrosion inhibitor.

Preferably, the corrosion inhibitor is polyethylene glycol.

Preferably, in the step S3, the reaming corrosion treatment is carried out 9 times every 28S time interval at a constant current density of 0.16A/cm ^-2.

Preferably, the step S4 is specifically that the reaming foil obtained in the step S3 is placed in an HCl solution with the temperature of 55-65 ℃ and the concentration of 2.5-5% for 40-60S, and is placed in an HNO ₃ solution with the temperature of 55-65 ℃ and the concentration of 2.5-5% for 40-60S after being cleaned by pure water, and is cleaned by pure water.

Preferably, the oven temperature in the step S5 is 60-180 ℃.

The method has the advantages that the nano-scale barium ferrite magnetic powder and the organic defoaming agent are added into the pore-forming liquid to prepare the aqueous solution BFE after being uniformly subjected to ultrasonic treatment, the aqueous solution BFE is added into the bath liquid, the magnetic powder is used for driving the organic defoaming agent to take water as a carrier, the barium ferrite magnetic powder can carry polyoxypropylene ether under the action of a magnetic field, the polyoxypropylene ether is gathered on the corroded tunnel holes through double electric layers, the polyoxypropylene ether permeates the double electric layers on the surfaces of the nano-scale hydrogen water magnetic suspension bubbles in the tunnel holes to enable the inner liquid and the outer liquid to flow rapidly, so that the liquid bubbles are broken, the generation of the nano-scale hydrogen magnetic suspension bubbles is restrained, the probability of branch hole formation is reduced, the capacity and the strength of a finished product foil are improved, the problem that in the prior art, the magnetic vortex effect can cause a large number of nano-scale hydrogen magnetic suspension bubbles to be generated in the groove, the bottom of the corroded holes are influenced, the further pore generation is further caused, the capacity and the strength of the finished product foil are influenced, the adsorption quantity of Cl ^- in the tunnel holes is improved, the corrosion is effectively is improved, and the uniformity of a residual core is greatly improved.

Drawings

FIG. 1 is a graph of polarization curve test with and without aqueous solution BFE;

FIG. 2 is a microscopic view of the residual core etch holes without the addition of water soluble BFE in sample 1;

FIG. 3 is a microscopic view of the residual core etch holes when the aqueous solution BFE is added to sample 2;

FIG. 4 is a microscopic view of the residual core etch holes when the aqueous solution BFE is added to sample 3;

FIG. 5 is a microscopic view of the residual core etch hole when the aqueous solution BFE is added to sample 4.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to be limiting.

A method for preparing a finished foil for inhibiting nanoscale hydrogen magnetic suspension bubbles, the method comprising the steps of:

Step S1, soaking the selected 125-135 mu m raw foil in a sodium hydroxide solution with the temperature of 70-80 ℃ and the concentration of 0.2-4% for 1-2min for pretreatment, and then washing with pure water;

Step S2, placing the original foil obtained in the step S1 into a pore-forming liquid containing 3% -5% of HCl, 30% -50% of H ₂SO₄, 0.5% -3% of Al and 0.02% -0.05% of aqueous solution BFE, cleaning the original foil with pure water after the pore-forming corrosion treatment for 3-5 times at intervals of 40-60S, wherein the strength of the upper N pole and the lower S pole is 0.02T-0.12T of constant magnetic field strength, and the constant current is 0.20A/cm ^-2-0.25 A/cm^-2 of constant current;

step S3, placing the porous foil obtained in the step S2 into a reaming solution containing 3% -8% of HNO ₃、0.07%- 0.14%H₃PO₄ and 0.02% -0.05% of corrosion inhibitor, performing reaming corrosion treatment for 7-9 times at intervals of 20-30S at constant current range of 0.16A/cm ^-2-0.18A/cm^-2, and cleaning with pure water;

Step S4, placing the reaming foil obtained in the step S3 in 55-65 ℃ and 2.5-5% HCl solution for 40-60S for post-treatment, washing with pure water, then placing in 55-65 ℃ and 2.5-5% HNO ₃ solution for 40-60S for post-treatment, and washing with pure water;

s5, placing the reaming foil obtained in the step S4 in a 60-180 ℃ oven for heat treatment, and cooling to normal temperature;

Step S6, performing formation treatment on the reaming foil obtained in the step S5, and cleaning and drying to obtain a finished foil;

Wherein, in the step S2, barium ferrite magnetic powder is added into the pore-forming liquid to drive aqueous solution BFE of an organic defoaming agent which takes water as a carrier, and the organic defoaming agent is organic ethers or organic silicon;

The preparation method of the aqueous solution BFE comprises the following steps of uniformly mixing 1-1.5g/L of 50-100nm barium ferrite magnetic powder, 2-5g/L of polyoxypropylene ether and water at normal temperature by ultrasonic waves to obtain the aqueous solution BFE.

Example 1

The normal wet 130 mu m original foil is adopted, and 1g/L of 100nm barium ferrite magnetic powder and 2g/L of polyoxypropylene ether are mixed for 20min under ultrasound at normal temperature.

S1, soaking the selected 130 mu m original foil in a sodium hydroxide solution with the concentration of 0.22 percent at 70 ℃ for 1.5min for pretreatment, and then washing with pure water;

S2, placing the original foil obtained in the S1 into a pore-forming liquid containing 3.2% of HCl, 50% of H ₂SO₄, 1.3% of Al and 0.02% of aqueous solution BFE, wherein the upper N pole and the lower S pole have constant magnetic field intensity of 0.06T, and cleaning the original foil with pure water after 5 pore-forming corrosion treatments at intervals of 60S and current of 0.20A/cm ^-2 constant current density;

S3, placing the porous foil obtained in the S2 into a reaming solution containing 7.1% HNO ₃、0.08%H₃PO₄ and 0.025% polyethylene glycol, performing reaming corrosion treatment for 9 times at intervals of 28S at constant current density of which the current range is 0.16A/cm ^-2, and cleaning with pure water;

S4, placing the reaming foil obtained in the S3 in a 55 ℃ and 2.5% HCl solution for 40S for aftertreatment, washing with pure water, then placing in a 55 ℃ and 5% HNO ₃ solution for 60S for aftertreatment, and washing with pure water;

s5, placing the reaming foil obtained in the S4 in a 100 ℃ oven for heat treatment, and cooling to normal temperature;

and S6, carrying out formation treatment on the reaming foil obtained in the step S5, and washing and drying to obtain a finished foil.

As shown in FIG. 1, the addition of 0.02% aqueous solution BFE and 0.05% aqueous solution BFE clearly shifted to the left from the corrosion potential compared with the addition of aqueous solution BFE, which means that the nano-scale hydrogen magnetic suspension bubbles blocked in the etching holes are inhibited by the aqueous solution BFE, and the etching holes adsorb more Cl ^- under the external magnetic field, and are more easily corroded.

Experimental data:

As shown in FIG. 2, the residual core is obviously supported at the etching holes of the residual core and is uneven by adding the aqueous solution BFE, and as shown in FIGS. 3-5, the residual core is obviously improved, more neat and uniform and the strength and the capacity are enhanced by adding the 0.02% aqueous solution BFE.

The foregoing has outlined and described the basic principles, features, and advantages of the present invention. However, the foregoing is merely specific examples of the present invention, and the technical features of the present invention are not limited thereto, and any other embodiments that are derived by those skilled in the art without departing from the technical solution of the present invention are included in the scope of the present invention.