阅读说明：本技术 一种利用纳米涂层提高脱模剂涂覆均匀性的方法 (Method for improving coating uniformity of release agent by using nano coating ) 是由 杨光 李月 于 2021-06-21 设计创作，主要内容包括：一种利用纳米涂层提高脱模剂涂覆均匀性的方法,涉及涂层和工业制造技术领域。包括以下步骤：1)配制重铬酸钾脱模剂溶液：在烧杯中加入去离子水,将重铬酸钾粉末加入烧杯中,搅拌；2)Cr涂层的制作：将清洗干净的芯模固定在溅射仓旋转台上,关闭仓门,打开循环冷水机及机械泵,对溅射仓进行抽真空,达到所需真空度后开启分子泵,通入氩气后打开电源进行溅射,利用膜厚仪监测沉积膜厚大小。通过在芯模表面沉积纳米厚度Cr薄膜,对表面进行改性,提高芯模表面能,进而有利于重铬酸钾溶液在铜模表面附着,实现涂覆均匀性,为芯模电铸脱模提供更有利的条件,提高铸件表面质量。能减少脱模剂涂覆时间,溅射方法制作的Cr涂层均匀性良好。(A method for improving the coating uniformity of a release agent by utilizing a nano coating relates to the technical field of coating and industrial manufacturing. The method comprises the following steps: 1) preparing a potassium dichromate release agent solution: adding deionized water into a beaker, adding potassium dichromate powder into the beaker, and stirring; 2) and (3) preparing a Cr coating: fixing the cleaned core mold on a sputtering bin rotating table, closing a bin door, opening a circulating water cooler and a mechanical pump, vacuumizing the sputtering bin, starting a molecular pump after the required vacuum degree is reached, opening a power supply for sputtering after argon is introduced, and monitoring the thickness of the deposited film by using a film thickness meter. The surface is modified by depositing the Cr film with the nanometer thickness on the surface of the core mould, so that the surface energy of the core mould is improved, the potassium dichromate solution is favorably attached to the surface of the copper mould, the coating uniformity is realized, more favorable conditions are provided for electroforming and demoulding of the core mould, and the surface quality of a casting is improved. The coating time of the release agent can be reduced, and the Cr coating prepared by the sputtering method has good uniformity.)

1. A method for improving the coating uniformity of a release agent by utilizing a nano coating is characterized by comprising the following steps:

1) preparing a potassium dichromate release agent solution: adding deionized water into a beaker, adding potassium dichromate powder into the beaker, and stirring;

2) and (3) preparing a Cr coating: fixing the cleaned core mold on a sputtering bin rotating table, closing a bin door, opening a circulating water cooler and a mechanical pump, vacuumizing the sputtering bin, starting a molecular pump after the required vacuum degree is reached, opening a power supply for sputtering after argon is introduced, and monitoring the thickness of the deposited film by using a film thickness meter.

2. The method for improving the coating uniformity of the release agent by using the nano coating as claimed in claim 1, wherein in the step 1), the temperature of the deionized water is 20-25 ℃.

3. The method for improving the coating uniformity of the release agent by using the nano coating as claimed in claim 1, wherein in the step 1), the addition amount of the potassium dichromate is 5-10% by mass of the deionized water; the mass-volume concentration of the potassium dichromate is 50 g/L-100 g/L.

4. The method for improving the coating uniformity of the release agent by using the nano coating as claimed in claim 1, wherein in the step 1), the obtained solution is allowed to stand at 20-25 ℃ for 1 h.

5. The method for improving the coating uniformity of the release agent by using the nano coating as claimed in claim 1, wherein in the step 2), the temperature of the circulating water cooler is 20-25 ℃; the required vacuum degree is 5.4X 10^-2～7.3×10^-2Pa; the rotating speed of the molecular pump is 90000 r/min; the argon flow is 30-50 sccm; the sputtering power is 150-250W, the substrate heating temperature is 30-50 ℃, the sputtering time is 15-30 s, the sample stage rotating speed is 10-20 rpm, and the thickness of the deposited Cr film is 5-20 nm.

Technical Field

The invention relates to the technical field of coatings and industrial manufacturing, in particular to a method for improving the coating uniformity of a release agent by using a nano coating.

Background

The replica of the surface structure of the metal mold is usually obtained by a precision electroforming process. The mold surface accuracy depends on the electroforming mold release quality. In the electroforming release process, the functional structure of the surface of the mold is damaged due to the excessive bonding force between the core mold and the replica, so that a release agent needs to be coated on the surface of the core mold for release before electroforming. The potassium dichromate solution is an industrial oneThe common release agent for assisting electroforming demolding can generate non-uniformity in the process of coating the surface of a mold with a structure, and further can cause the phenomenon that demolding is difficult in the electroforming demolding process of the mold or the microstructure of the surface of the mold is locally damaged after demolding, so that the surface precision of the mold is reduced, and a core mold is damaged. The main reason is that the surface of the metal core mold has poor hydrophilicity, so that the potassium dichromate solution is distributed on the surface of the mold in the form of droplets, and only a local anti-adhesion effect is formed due to the existence of a surface structure. For release agents that are difficult to disperse in aqueous solutions, kunming corp-seine scientific limited liability company and university of kunming corp utilize improved coating devices to increase the uniformity of mixing of the release agent with the aqueous solution in order to increase the release agent application uniformity (a device for uniformly applying the release agent, 201921244397.3). The data show that the solid surface energy can be increased by depositing a Cr oxide film on the metal surface (Machilus thunbergii plasma spraying Cr₂O₃Study of surface free energy and tribological properties of the base coating 2016). The potassium dichromate is easy to dissolve in water, and in order to realize the coating uniformity of the potassium dichromate solution on the surface of the die, the invention utilizes a physical deposition method to deposit a Cr thin layer with a nanometer thickness on the surface of a core die to form Cr₂O₃The surface energy of the core die can be increased, namely the hydrophilicity of the surface is increased, on the basis, the uniform coating of the potassium dichromate solution is realized, the service life of the core die can be prolonged, and the surface quality of the casting is greatly improved.

Disclosure of Invention

The invention aims to provide a method for improving the coating uniformity of a release agent by using a nano coating, which is used for improving the coating uniformity of a potassium dichromate release agent by depositing a layer of Cr film with a nano thickness on the surface of a core mould in a physical deposition mode (including magnetron sputtering, plasma spraying or evaporation).

The invention comprises the following steps:

1) preparing a potassium dichromate release agent solution: adding deionized water into a beaker, adding potassium dichromate powder into the beaker, and stirring;

2) and (3) preparing a Cr coating: fixing the cleaned core mold on a sputtering bin rotating table of a magnetron sputtering instrument, closing a bin door, opening a circulating water cooler and a mechanical pump, vacuumizing the sputtering bin, starting a molecular pump after reaching the required vacuum degree, opening a power supply for sputtering after introducing argon, and monitoring the thickness of the deposited film by using a film thickness instrument.

In the step 1), the temperature of the deionized water can be 20-25 ℃; the addition amount of the potassium dichromate can be 5 to 10 percent of deionized water by mass percent; the mass-volume concentration of the potassium dichromate can be 50 g/L-100 g/L; the obtained solution can be kept stand for 1h at the temperature of 20-25 ℃.

In the step 2), the temperature of the circulating water cooler can be 20-25 ℃; the required vacuum degree can be 5.4X 10^-2～7.3×10^-2Pa; the rotating speed of the molecular pump is 90000 r/min; the flow of argon gas can be 30-50 sccm; the sputtering power can be 150-250W, the substrate heating temperature can be 30-50 ℃, the sputtering time can be 15-30 s, the sample stage rotating speed can be 10-20 rpm, and the thickness of the deposited Cr film is 5-20 nm.

According to the invention, the surface is modified by depositing the Cr film with the nanometer thickness on the surface of the core mold, so that the surface energy of the core mold is improved, the adhesion of a potassium dichromate solution on the surface of a copper mold is facilitated, the coating uniformity is realized, more favorable conditions are provided for electroforming and demolding of the core mold, and the surface quality of a casting is improved.

The invention has the following outstanding technical effects:

1) the sputtering parameters can be conveniently adjusted by using a direct current power supply and a display panel in production.

2) The uniformity of the Cr coating prepared by the sputtering method is good.

3) The release agent application time can be reduced.

4) For different material core moulds, the coating uniformity of the potassium dichromate solution is optimized and controlled by adjusting parameters such as the sputtering time, power and the like of the Cr coating, and further, the size of the electroforming demoulding force and the demoulding quality are optimized.

5) The microstructure optical film copper core mold is simple to implement, mirror surface quality can be obtained after demolding, the roughness is below 10 nanometers, and the optical performance is greatly improved.

Drawings

FIG. 1 is a schematic view of a lens array structure core mold (Cu) used in embodiments 1 to 3 of the present invention.

FIG. 2 is a distribution diagram of the surface of a lens copper mold coated with a potassium dichromate release agent directly in example 1 of the present invention.

FIG. 3 is a graph showing the surface distribution of a potassium dichromate release agent coated on a lens copper mold with a Cr coating layer according to example 1 of the present invention.

Detailed Description

The following examples will further illustrate the present invention with reference to the accompanying drawings.

Example 1

Preparing a potassium dichromate release agent solution: according to the surface area of the lens structure in the figure 1, 5g of potassium dichromate is weighed, 100mL of deionized water is added into a beaker at the temperature of 20 ℃, the mixture is fully stirred and stands for 1 h.

Pretreatment of the copper mold: activating the copper mold with acetic acid, degreasing with acetone, washing with deionized water, and air drying.

And (3) preparing a Cr coating: putting the cleaned copper mold into a sputtering bin of a magnetron sputtering instrument (the model can be VTC-600-3HD), closing a valve, opening a water cooler and a control panel, starting a mechanical pump for vacuumizing, adjusting the power of a direct current power supply to be 150W, the time to be 15s, adjusting the heating temperature of a control panel substrate to be 35 ℃, the rotating speed of a sample stage to be 12rpm and the argon flow to be 35sccm, and testing the average thickness of the Cr film to be 5.5nm by using a Quartz Crystal film thickness monitor (Quartz Crystal Microbalance, QCM for short, EQ-TM106) attached to the magnetron sputtering instrument.

Coating with a potassium dichromate solution: firstly, coating the prepared potassium dichromate solution on the surface of an unmodified copper mold, standing for 5min, pouring the potassium dichromate solution on the surface of the copper mold, and observing the surface by using an optical microscope after the surface is dried, as shown in figure 2. Secondly, coating the prepared potassium dichromate solution on the surface of the copper mould deposited with the Cr coating, standing for 15s, spraying the potassium dichromate solution on the surface of the copper mould, and observing the surface by using an optical microscope after the surface is dried, as shown in figure 3. Comparing fig. 2 and fig. 3, it can be seen that the surface distribution of the potassium dichromate release agent solution directly coated on the surface of the copper mold is very uneven, and the coating uniformity is greatly improved by depositing the Cr coating.

Example 2

Preparing a potassium dichromate release agent solution: according to the surface area of the lens structure in the figure 1, 8g of potassium dichromate is weighed, the temperature is 25 ℃, 100mL of deionized water is added into a beaker, the mixture is fully stirred, and the mixture is kept stand for 1 hour.

Pretreatment of the copper mold: activating the copper mold with acetic acid, degreasing with acetone, washing with deionized water, and air drying.

And (3) preparing a Cr coating: putting the cleaned copper mold into a sputtering bin of a magnetron sputtering instrument (the model is VTC-600-3HD), closing a valve, opening a water cooler and a control panel, starting a mechanical pump for vacuumizing, adjusting the power of a direct current power supply to be 200W, the time to be 18s, adjusting the heating temperature of a control panel substrate to be 40 ℃, the rotating speed of a sample stage to be 16rpm and the argon flow to be 40sccm, and testing the average thickness of the Cr film to be 8.5nm by utilizing a Quartz Crystal film thickness monitor (Quartz Crystal Microbalance, QCM for short, EQ-TM106) attached to the magnetron sputtering instrument.

Coating with a potassium dichromate solution: firstly, coating the prepared potassium dichromate solution on the surface of an unmodified copper mold, standing for 8min, pouring the potassium dichromate solution on the surface of the copper mold, and observing the surface by using an optical microscope after the surface is dried. And secondly, coating the prepared potassium dichromate solution on the surface of the copper mold deposited with the Cr coating, standing for 20s, pouring the potassium dichromate solution on the surface of the copper mold, and observing the surface by using an optical microscope after the surface is dried. Comparing the two results, the surface distribution of the potassium dichromate release agent solution directly coated on the surface of the copper die is very uneven, and the coating uniformity is greatly improved after the Cr coating is deposited.

Example 3

Preparing a potassium dichromate release agent solution: according to the surface area of the lens structure in the figure 1, 10g of potassium dichromate is weighed, 100mL of deionized water is added into a beaker at the temperature of 30 ℃, the mixture is fully stirred and stands for 1 h.

Pretreatment of the copper mold: activating the copper mold with acetic acid, degreasing with acetone, washing with deionized water, and air drying.

And (3) preparing a Cr coating: putting the cleaned copper mold into a sputtering bin of a magnetron sputtering instrument (the model is VTC-600-3HD), closing a valve, opening a water cooler and a control panel, starting a mechanical pump for vacuumizing, adjusting the power of a direct current power supply to be 250W, the time to be 20s, adjusting the heating temperature of a control panel substrate to be 45 ℃, the rotating speed of a sample stage to be 20rpm and the argon flow to be 45sccm, and testing the average thickness of the Cr film to be 10.5nm by utilizing a Quartz Crystal film thickness monitor (Quartz Crystal Microbalance, QCM for short, EQ-TM106) attached to the magnetron sputtering instrument.

Coating with a potassium dichromate solution: firstly, coating the prepared potassium dichromate solution on the surface of an unmodified copper mold, standing for 10min, pouring the potassium dichromate solution on the surface of the copper mold, and observing the surface by using an optical microscope after the surface is dried. And secondly, coating the prepared potassium dichromate solution on the surface of the copper mold deposited with the Cr coating, standing for 20s, pouring the potassium dichromate solution on the surface of the copper mold, and observing the surface by using an optical microscope after the surface is dried. Comparing the two results, the surface distribution of the potassium dichromate release agent solution directly coated on the surface of the copper die is very uneven, and the coating uniformity is greatly improved after the Cr coating is deposited.

The above-described embodiments are merely preferred embodiments of the present invention, and should not be construed as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.