阅读说明：本技术 一种自控电解铁箔溶液 (Self-control electrolytic iron foil solution ) 是由 苏长伟 熊涛 姚旭耀 刘扬扬 吴锋景 肖鑫 易翔 邓继勇 刘家炎 于 2021-07-12 设计创作，主要内容包括：电解铁箔技术关键是控制三价铁离子,尽管研究者提出了抗氧化剂的抑制方法和络合剂的隐蔽方法来控制,但是长时间效果不佳,导致生产过程控制困难,铁箔价格高昂,应用受限。本发明提出一种能够自我控制三价铁离子的电解铁箔溶液,经过长达1000Ah/L电解试验后,仍然能够获得致密的、灰白色、对折不断的铁箔,因此过程控制溶液,易于规模化生产。(The key point of the electrolytic iron foil technology is the control of ferric ions, and although researchers propose an antioxidant inhibition method and a complexing agent hiding method for control, the effect is poor for a long time, so that the production process is difficult to control, and the iron foil is high in price and limited in application. The invention provides an electrolytic iron foil solution capable of self-controlling ferric ions, which can still obtain compact, grey-white and continuous iron foil after 1000Ah/L electrolytic test, so that the process control solution is easy for large-scale production.)

1. The self-controlled electrolytic iron foil solution features that quaternary ammonium salt (C) is added into ferrous salt water solution_nH_2n+1)₄N⁺(n is not less than 2 and not more than 5) to a concentration of 0.001～0.2mol/L。

2. The ferrous salt according to claim 1, which is one or two of ferrous chloride, ferrous sulfate and ferrous sulfamate.

Technical Field

The invention belongs to the field of manufacturing of ultrathin metal foil, and particularly relates to an electrolytic iron foil technology.

Background

The industrial application of electrolytic iron foil was limited by the fact that the electrolytic iron foil was produced first in japan in 1981 and has been already produced for 40 years, and the final iron foil is expensive and even more expensive than the copper foil due to the difficulty in controlling the production process although the raw materials are very cheap. At present, no large electrolytic iron foil manufacturer exists in the market of China.

The electrolytic iron foil research is carried out in 90 years in the last century in China, Luvicang and the like use Japanese technology for reference, and the method for preparing the pure iron foil by electrolytic forming is applied for patent of invention and method (CN 91102934.6) for obtaining the ultrathin iron foil with the thickness of 20 microns by utilizing the soluble anode and effectively controlling the components of the plating solution, particularly the content of ferric iron. However, ferrous ions inevitably oxidize to form ferric ions when contacting with air, while ferric hydroxide has a low solubility product, forms a colloid or precipitates and adsorbs to the surface of an electrode to be included in a plating layer, thereby causing a decrease in the quality of an iron foil, such as an increase in porosity, embrittlement and the like, and studies have shown that this is caused even at a pH of about =0.5 when the concentration of ferric ions is greater than 0.005 mol/L. People inhibit the oxidation of ferrous ions by adding rare earth elements, but have little effect at high temperature, see the master 'study on electroformed iron foil preparation and rare earth modification' (Zhengjinwu, Zhejiang university of industry, 2003); the addition of antioxidants (i.e. reducing agents) prevents the production of divalent iron, like organic ascorbic acid, inorganic divalent vanadium ions (which are themselves oxidized to trivalent vanadium, which is reduced to divalent vanadium at the cathode), but inevitably affects the iron foil properties. At present, in the process of electroplating iron-nickel and iron-tungsten alloy, complexing agent such as citric acid is added to complex ferric ions, so that the influence of the formation of ferric hydroxide on the quality of a coating is avoided. However, the generation of the ferric iron cannot be completely inhibited, and the reduction is often carried out by using a small current or adding iron powder in the generation process, so that the ferric iron is further controlled to a lower level, and great difficulty is brought to the process control.

The invention provides a self-control electrolytic iron foil solution which can effectively reduce the concentration of ferric ions, avoid the influence of the ferric ions on the quality of the iron foil, reduce the process control cost, and preliminarily estimate the processing cost lower than that of electrolytic copper foil, thereby having market prospect.

Disclosure of Invention

The invention aims to find a self-control electrolytic iron foil solution capable of self-controlling the concentration of ferric ions and promote the industrialization process of electrolytic iron foils and iron-based alloy foils.

The technical scheme for realizing the purpose of the invention is as follows: adding homobranched quaternary ammonium salt into conventional chloride, sulfate, sulfamate and their composite solution_nH_2n+1)₄N⁺And (n is more than or equal to 2 and less than or equal to 5), the newly generated ferric ions and the quaternary ammonium salt form a compound which is insoluble in the electrolyte, and the compound floats on the surface of the electrolyte (because the density of the compound is less than that of the electrolyte), is very easy to remove similar to a froth flotation beneficiation technology, so the ferric ions in the electrolyte can be automatically controlled, and the self-control electrolytic iron foil solution is provided. In addition, the compound is not adsorbed on the surface of the electrode and codeposits with iron, so the quality of the iron foil is not influenced.

Compared with the prior art, the invention has the following outstanding advantages:

the electrolytic iron foil solution provided by the invention can automatically remove the newly produced ferric ions in the plating solution, is different from the conventional inhibiting method by an antioxidant and the concealing method by a complexing agent, and does not generate the toxic condition on the plating solution due to the decomposition of organic acid radical ions. After long-life experiments of 1000Ah/L are carried out, compact, grey-white and continuous iron foil is still obtained, so that the solution is controlled in the process, and the large-scale production is easy to realize.

Drawings

FIG. 1 is a photograph of a plating solution containing ferric ions to which tetrabutylammonium chloride is added;

FIG. 2 is a photograph of an iron foil obtained by electrodeposition of a chloride system with tetrabutylammonium chloride.

Detailed description of the preferred embodiment

Example 1

Accurately weighing 550g of analytically pure ferrous chloride tetrahydrate and 15g of chemically pure boric acid by using an electronic balance, putting the weighed materials into a 1000ml beaker, adding 4/5 volumes of distilled water into the beaker, stirring and dissolving the materials, and adding saltThe acid was adjusted to pH =2.0 and the volume was 1000 ml. Dividing into 4 cups of solution, adding 0, 0.001, 0.005, 0.01mol/L tetrabutyl ammonium chloride (C)₄H₉)₄N⁺Cl^-. Performing electrodeposition iron foil experiment respectively under the operating conditions of 95 deg.C and 10A/dm current density²The anode was a pure iron rod for 20min (as was the case for the operating conditions of the electrodeposited iron foil experiments in the examples below). Obtaining gray and continuous iron foil with compact surface on the cathode titanium sheet;

adjusting pH of the 4 cups of solution to 1.5, 1.0 and 0.5 with hydrochloric acid, and performing electrodeposition experiment at 95 deg.C and density of 10A/dm²And after 20min, the iron foil with compact surface, grey white color and continuous folding is also obtained. It is shown that tetrabutylammonium chloride has no influence on the foil formation behavior.

Example 2

The tetrabutylammonium chloride in example 1 was exchanged for tetraethylammonium chloride ((C)₂H₅)₄N⁺Cl^-) Tetrapropylammonium chloride ((C)₃H₇)₄N⁺Cl^-) And tetrapentyl ammonium chloride ((C)₅H₁₁)₄N⁺Cl^-) The same quaternary ammonium salt (C) can be obtained by folding the dense, grey-white and continuous iron foil on the surface_nH_2n+1)₄N⁺And (n is more than or equal to 2 and less than or equal to 5) does not influence the foil forming behavior.

Example 3

Accurately weighing 550g of analytically pure ferrous chloride tetrahydrate and 15g of chemically pure boric acid by using an electronic balance, putting the weighed materials into a 1000ml beaker, adding 4/5 volumes of distilled water into the beaker, stirring and dissolving the materials, adding hydrochloric acid to adjust the pH to be =1.0, and adding 0.005mol/L FeCl₃The volume is up to 1000 ml. The solution was divided into 4 equivalent volumes, and 0.01mol/L of (C) was added_nH_2n+1)₄N⁺Cl, (n is more than or equal to 2 and less than or equal to 5). Stirring again, a layer of red-brown ferric ions and homobranched quaternary ammonium salt exist on the surface of the plating solution, (C)_nH_2n+1)₄N⁺(2. ltoreq. n. ltoreq.5) in the form of a suspension, see FIG. 1. The experiment of directly electrodepositing the iron foil can still be carried out without filtering treatmentThe iron foil with compact surface, grey white color and continuous folding is obtained. The edges of the iron foil obtained in the solution without adding the quaternary ammonium salt are peeled and cut, which shows that the ferric ions cause the iron foil to become brittle. Homobranched quaternary ammonium salt, (C)_nH_2n+1)₄N⁺And (n is more than or equal to 2 and less than or equal to 5) can effectively remove ferric ions.

Example 4

The chloride system of example 3 was replaced by a sulfate system for testing. Accurately weighing 500g of analytically pure ferrous sulfate heptahydrate and 15g of chemically pure boric acid by using an electronic balance, putting the weighed materials into a 1000ml beaker, adding 4/5 volumes of distilled water into the beaker, stirring and dissolving the materials, adding sulfuric acid to adjust the pH to be =1.0, and adding 0.005mol/L FeCl₃The volume is up to 1000 ml. The solution was divided into 4 equal volumes, and 0.01mol/L ((C)_nH_2n+1)₄N⁺Cl^-(n is more than or equal to 2 and less than or equal to 5). Direct electrodeposition of iron foil experiments, without filtration, still yielded a dense, off-white surface iron foil, but was harder than the chloride system. The plating layer in the solution without adding quaternary ammonium salt is peeled in large area, and only flake-shaped iron foil can be obtained. Indicating that the ferric ions cause the iron foil to become brittle, the quaternary ammonium salt (C)_nH_2n+1)₄N⁺And (n is more than or equal to 2 and less than or equal to 5) can effectively remove ferric ions.

Example 5

The chloride system of example 3 was replaced by a sulfamate system for testing. Accurately weighing 120g of reduced iron powder by using an electronic balance, dissolving by using sulfamic acid until the reduced iron powder is completely dissolved, adding 15g of chemically pure boric acid, putting the chemically pure boric acid into a 1000ml beaker, adding 4/5 of distilled water to the volume of the beaker, adding sulfamic acid to adjust the pH to be =1.0, and adding 0.005mol/L FeCl₃The volume is up to 1000 ml. The solution was divided into 4 equivalent volumes, and 0.01mol/L of (C) was added_nH_2n+1)₄N⁺Cl^-(n is more than or equal to 2 and less than or equal to 5). The iron foil with compact surface, grey white color and continuous folding can still be obtained through direct electrodeposition iron foil experiments without filtering treatment. Indicating homobranched quaternary ammonium salt, (C)_nH_2n+1)₄N⁺And (n is more than or equal to 2 and less than or equal to 5) can effectively remove ferric ions.

Example 6

Long life cycle experiments were performed. 550g of analytically pure ferrous chloride tetrahydrate and 15g of chemically pure boric acid are accurately weighed by an electronic balance, the analytically pure ferrous chloride tetrahydrate and the chemically pure boric acid are placed into a 1000ml beaker, 4/5 volumes of distilled water are added into the beaker, the distilled water is stirred and dissolved, hydrochloric acid is added to adjust the pH to be =1.0, and the volume is adjusted to be 1000 ml. The solution was divided into 4 cups in equal amounts, and 0.001 mol/L, 0.01mol/L, 0.1mol/L and 0.2mol/L of (C) were added₄H₉)₄N⁺Cl^-. And (3) carrying out a continuous electrodeposition iron foil experiment, after electrolyzing for 1000Ah/L, the three solutions can still obtain the gray iron foil with compact surface and continuous folding, the edge does not peel, and the picture of the iron foil is shown in figure 2. And at 0.001 mol/L (C)₄H₉）₄The iron foil is obtained from the solution of NCl, the edge is warped and peeled, the middle is compact and grey white, and the iron foil is broken and is continuously folded to a 90-degree angle. The consumption of the quaternary ammonium salt with the same branch is low in the long-life cycle process, and the reddish brown layer is formed by ferric ions and the quaternary ammonium salt with the same branch (C)_nH_2n+1)₄N⁺And n is more than or equal to 2 and less than or equal to 5), and the formed suspended matters isolate air and prevent the generation of ferric iron. Therefore, the concentration of the quaternary ammonium salt is in the range of 0.001 to 0.2 mol/L.

Example 7

The effect of quaternary ammonium salts on bath concentration, temperature and current density was examined. Taking a chloridizer as an example, 0.01mol/L (C) is added₄H₉)₄N⁺Cl^-Referring to a method for preparing a pure iron foil by electrolytic forming (CN 91102934.6) and a method for preparing an electroformed iron foil and rare earth modification research (Zhengjinwu, Zhejiang university of industry, 2003), the method is characterized in that the concentration of iron ions is 70-140 g/L, the temperature is 80-100 ℃, and the current density is 1-10A/dm²Within the range, compact, grey white and continuous iron foil can be obtained, and quaternary ammonium salt has no influence on the concentration, temperature and current density parameters of the plating solution.