CN117238747A - A peeling layer with reduced peeling strength and its manufacturing method, information display element and its manufacturing method - Google Patents

Abstract

The invention discloses a method for manufacturing a peeling layer. The manufacturing method of the peeling layer includes the following steps: preparing a supporting substrate; and forming a graphene oxide layer on the supporting substrate.

Description

A peeling layer with reduced peeling strength and its manufacturing method, information display element and its manufacturing method

Technical field

The invention relates to a peeling layer with reduced peeling strength and a manufacturing method thereof, an information display element and a manufacturing method thereof, and relates to a method of adjusting the size of graphene oxide forming a peeling layer and adjusting the composition ratio of graphene oxides of different sizes. , thereby increasing the coating rate of the graphene oxide layer and reducing the peeling strength of the peeling layer, the peeling layer and its manufacturing method, the information display element and its manufacturing method.

Background technique

As the commercialization of wearable devices such as smart glasses accelerates, the necessity and demand for flexible information display components such as flexible displays are increasing.

In the manufacturing process of the flexible information display element, the flexible substrate is laminated on the supporting substrate, and then the manufacturing process is performed. In the final process, a process of separating the flexible substrate from the supporting substrate is performed.

As the flexible substrate, polyimide is mainly used, and as the supporting substrate, a glass substrate is used. A method of forming a flexible substrate on a supporting substrate is as follows: coating polyimide varnish on the supporting substrate and curing it at a high temperature to form a flexible substrate on the supporting substrate. During this process, chemical bonding occurs between the polyimide and the support substrate, which increases the adhesion between the support substrate and the flexible substrate, making it difficult to separate them without additional processes.

In order to solve this problem, in the prior art, the laser lift-off (LLO) process is mainly used as a process for peeling off the flexible substrate from the support substrate.

However, if a laser is used, there is a problem that an expensive laser lift-off device is required and is not suitable for large-area processes.

Contents of the invention

Problems to be solved by inventions

The present invention is proposed to solve the above problems. The purpose of the present invention is to provide a peeling layer and a manufacturing method thereof, an information display element and a manufacturing method thereof, which form a graphene oxide layer as a peeling layer of a flexible information display element, And by adjusting the size of graphene oxide forming the graphene oxide layer and adjusting the composition ratio of graphene oxide of different sizes, the peeling strength of the graphene oxide layer is reduced.

Another object of the present invention is to provide a peeling layer and a manufacturing method thereof, an information display element and a manufacturing method thereof, which do not require the use of an expensive laser peeling device, so the manufacturing cost is low and can be applied to large-area processes.

Another object of the present invention is to provide a peeling layer and a manufacturing method thereof, an information display element and a manufacturing method thereof, which can eliminate the need for a cationic polymer electrolyte solution due to electrospray coating when forming the graphene oxide layer. coating process, thus saving time in the manufacturing process and reducing manufacturing costs.

Methods used to solve problems

In order to achieve the above object, the manufacturing method of the release layer according to the present invention may include the following steps: a step of preparing a supporting substrate; and a step of forming a graphene oxide layer on the supporting substrate.

The release layer according to the present invention can be manufactured by the manufacturing method of the release layer.

In order to achieve the other purpose mentioned above, the manufacturing method of an information display element according to the present invention may include the following steps: preparing a supporting substrate; forming a graphene oxide layer on the supporting substrate; and forming a graphene oxide layer on the graphene oxide layer. The step of forming a flexible substrate; and the step of separating the support substrate and the flexible substrate.

The information display element according to the present invention can be manufactured by the manufacturing method of the information display element.

Invention effect

According to the present invention, since there is no need to use an expensive laser lift-off device, the manufacturing cost is low and the method is applicable to large-area processes.

In addition, by adjusting the size of graphene oxide forming the graphene oxide layer and adjusting the composition ratio of graphene oxide of different sizes to increase the coating rate of the release layer on the support substrate, it is possible to achieve high temperature exposure when manufacturing flexible substrates. And under the conditions of high temperature and plasma during the manufacturing process of the display screen, it prevents the chemical bonding between the supporting substrate, that is, the glass substrate and the polyimide, so as to achieve the effect of reducing the peeling strength. In addition, since the peeling strength can be reduced while forming a thin film layer, there is an advantage that an excellent level of light transmittance can be maintained.

In addition, in the present invention, the graphene oxide dispersion is micro-sprayed using electrospray, and a voltage can be applied. Therefore, electrostatic attraction between the support substrate and the graphene oxide dispersion can be induced to form a thin graphene oxide layer. Therefore, there is an advantage that the conventional coating process of the cationic polymer electrolyte solution performed before forming the graphene oxide layer can be omitted.

Description of drawings

Figure 1 is a flow chart of a method for manufacturing a release layer according to an embodiment of the present invention;

Figure 2 is a flow chart of a manufacturing method of an information display element according to an embodiment of the present invention;

Figure 3 is a flow chart of a flexible substrate forming process according to an embodiment of the present invention;

4 is a cross-sectional view schematically illustrating each layer formed in a manufacturing method of an information display element according to an embodiment of the present invention;

5 is a cross-sectional view schematically illustrating the separation process of the support substrate and the flexible substrate in the manufacturing process of the information display element according to an embodiment of the present invention.

Reference signs:

S10: Prepare the supporting substrate; S20: Form the graphene oxide layer; S30: Form the flexible substrate; S40: Separate the supporting substrate and the flexible substrate; 10: Supporting substrate; 20: Peeling layer; 30: Flexible substrate.

Detailed ways

The technical terms used in this specification are only used to describe specific embodiments. It should be noted that these technical terms are not used to limit the present invention. In addition, the technical terms used in this specification should be interpreted as meanings commonly understood by those of ordinary skill in the technical field to which the present invention belongs. Unless otherwise specifically defined in this specification, they should not be overly generalized. meaning or an over-reduced meaning. In addition, if the technical terms used in this specification are incorrect technical terms that cannot accurately describe the idea of the present invention, the incorrect technical terms should be replaced with technical terms that can be accurately understood by those of ordinary skill in the art and understood.

In addition, general terms used in this specification should be interpreted based on the definitions in the dictionary or based on the context, and should not be interpreted with an excessively narrowed meaning.

In addition, descriptions of the singular used in this specification include the plural if the context does not produce other meanings. In addition, in this application, terms such as "constituting" or "comprising" should not be interpreted as necessarily including all the various constituent elements or various steps described in the specification, but should be interpreted as meaning that some of the constituent elements may not be included. or part of the steps, or may further include other constituent elements or steps.

Hereinafter, the present invention will be described in more detail using examples, but the scope of the present invention is not limited by the following examples.

Figure 1 is a flow chart of a method for manufacturing a release layer according to an embodiment of the present invention.

Referring to FIG. 1 , a method for manufacturing a peeling layer according to an embodiment of the present invention may include the following steps: preparing a support substrate S10 ; and forming a graphene oxide layer S20 .

At this time, the supporting substrate may be a glass substrate, a polymer film or a silicon wafer. However, the support substrate according to the present invention is not necessarily limited to this.

The supporting substrate may include a step of cleaning the supporting substrate and a step of surface treating the supporting substrate.

At this time, the step of cleaning the support substrate may be as follows: immersing the support substrate in an ethanol solution, and then cleaning the support substrate using ultrasonic waves. Thereafter, the support substrate may be immersed in an isopropyl alcohol solution and then cleaned using ultrasonic waves.

The support substrate that has undergone the cleaning process may be dried.

The step S20 of forming the graphene oxide layer may include the step of coating the graphene oxide dispersion liquid on the support substrate.

At this time, the coating may be electrosprayed.

The electrospray coating can be performed under the conditions of a spray speed of 70 to 90 μL/min, an air pressure of 0.2 to 0.3 MPa, and a voltage of 9 kV or more. Preferably, the spraying speed may be 80 μL/min, the air pressure may be 0.25MPa, and the voltage may be 10kV.

The lower the spraying speed is than 70μL/min, the smaller the number of water droplets sprayed due to insufficient capacity, so there is a problem of difficulty in uniform coating. The higher the spraying speed is higher than 90μL/min, the lower the spraying force is compared with the capacity, so There is a problem of coating larger water droplets.

The lower the air pressure is than 0.2MPa, the smaller the spray force is, so there is a problem of coating larger water droplets. The higher the air pressure is higher than 0.3MPa, the less the sprayed water droplets can reach the substrate, so there is a problem of reduced coating area.

As the voltage is lower than 9 kV, there is a problem that the size of the sprayed water droplets becomes larger. However, when the voltage is 9 kV or more, fine spraying can be sufficiently performed.

The concentration of the graphene oxide dispersion may be 0.01 to 0.02% by weight. Preferably, the concentration may be 0.01% by weight.

When the concentration is lower than 0.01% by weight, the coating rate is lower, so there is a problem of increased peel strength. When the concentration is higher than 0.02% by weight, there is a problem of lower transmittance.

According to an embodiment, the graphene oxide dispersion may include a first graphene oxide and a second graphene oxide, the size of the first graphene oxide may be 50 μm, and the size of the second graphene oxide may be 1um.

The graphene oxide dispersion liquid may include the first graphene oxide and the second graphene oxide in a ratio of 5:5 to 8:2.

When the content of the second graphene oxide is greater than the content of the first graphene oxide, there is a problem that the coating rate is reduced, resulting in an increase in peel strength.

According to another embodiment, the graphene oxide dispersion may include graphene oxide with a size of 50 μm. At this time, the graphene oxide dispersion may only contain graphene oxide with a size of 50 μm and not contain graphene oxide with a size of 1 μm.

That is to say, in the present invention, graphene oxide with a size of 50um and graphene oxide with a size of 1um can be included simultaneously, and the composition range of the graphene oxide with a size of 50um and the graphene oxide with a size of 1um is set to In the range of 5:5 to 8:2, or by making the graphene oxide contained in the graphene oxide dispersion only graphene oxide with a size of 50um, the coating rate of the graphene oxide layer can be increased, and the result is Yes, it can bring about the effect of reducing the peel strength of the peel layer.

This improvement in peel strength can bring about the effect of reducing the peel strength when peeling off after the process of manufacturing the information display element device.

FIG. 2 is a flow chart of a manufacturing method of an information display element according to an embodiment of the present invention. FIG. 3 is a flow chart of a flexible substrate forming process according to an embodiment of the present invention.

Referring to Figure 2, a manufacturing method for manufacturing an information display element according to an embodiment of the present invention may include the following steps: step S10 of preparing a support substrate; step S20 of forming a graphene oxide layer; step S30 of forming a flexible substrate; and separating the support substrate and step S40 of the flexible substrate.

The structures of the step S10 of preparing the supporting substrate and the step S20 of forming the graphene oxide layer are the same as those described above with reference to FIG. 1 , and therefore the redundant description is omitted.

Referring to FIG. 3 , the step S30 of forming a flexible substrate may include the following steps: a step S32 of coating the flexible substrate substance and a step S34 of heating the flexible substrate substance.

In the step S32 of coating the flexible substrate substance, the substance coated on the graphene oxide layer may be selected from polyimide, polyester, polyethylene, polycarbonate, polyethylene, polyvinyl ester, Any one from the group consisting of polyethersulfone, polyacrylate, polyethylene naphthalate, and polyethylene terephthalate. In the step of heating and curing the applied substance, curing conditions may vary depending on the applied substance.

If the flexible substrate material is polyimide, because it uses polyimide varnish, a heating and curing step is required. In the heating step S34, it can be heated from normal temperature to 350°C. At this time, the temperature can be adjusted every minutes to rise by 5°C.

For example, it can be heated at 100°C for 10 minutes, at 200°C for 30 minutes, and at 350°C for 30 minutes. After that, let it cool naturally for about 3 hours.

In the step S40 of separating the support substrate and the flexible substrate, physical force may be used to separate the support substrate and the flexible substrate.

4 is a cross-sectional view schematically illustrating each layer formed in a method of manufacturing an information display element according to an embodiment of the present invention. 5 is a cross-sectional view schematically illustrating the separation process of the support substrate and the flexible substrate in the manufacturing process of the information display element according to an embodiment of the present invention. The description of Figures 4 and 5 will be described in further detail based on the following embodiments.

Below, the process of manufacturing the peeling layer according to the present invention is explained in more detail through examples. The following examples are provided to make it easier to understand the present invention, and therefore the content of the present invention is not limited to these examples.

<Raw materials used in examples>

-Bare Glass (Eagle XG, Corning Company)

-0.01% by weight graphene oxide (Graphene Oxide) aqueous solution

Example 1

<Steps to prepare the support substrate>

First, as the support substrate 10, Eagle XG glass (Corning Co., Ltd.) having a width and a length of 100 mm and a thickness of 0.5 mm was prepared.

The support substrate 10 is immersed in an ethanol solution, and then ultrasonic cleaned for about 15 minutes. After that, the support substrate 10 is immersed in an isopropyl alcohol solution, and then ultrasonic cleaning is performed for about 15 minutes. The cleaned support substrate 10 is placed in an oven and dried at about 80° C. for about 5 minutes.

<Steps for forming peeling layer>

Then, in order to form a graphene oxide layer, a 0.01% by weight graphene oxide (GO) dispersion liquid was prepared.

More specifically, Hummer's method is used to prepare graphene oxide. Graphene oxide with a size of 1um uses ultrasonic pulverization method, and graphene oxide with a size of 50um uses a shear stress method to control the size of graphene oxide.

Take 2g of the 1um-sized graphene oxide solution with an initial concentration of 0.5% by weight and 2g of the 50um-sized graphene oxide solution with an initial concentration of 0.5% by weight, and then add 98g of triple distilled water to prepare 0.01% by weight of the 1um-sized graphene oxide solution. Graphene oxide dispersion and 0.01% by weight of 50um size graphene oxide dispersion.

Mix 0.01 wt % of 50 um size graphene oxide dispersion 50 g and 0.01 wt % of 1 um size graphene oxide dispersion 50 g to prepare 100 g of graphene oxide dispersion (0.01 wt % of 50 um size graphene oxide dispersion The ratio of liquid and 0.01% by weight of 1um size graphene oxide dispersion is 5:5). Inject 10 ml of 100 g of graphene oxide dispersion into two syringes, combine the syringes and nozzles, and then install them on the electrospray device (NanoNC, model name: ESR200R2).

After setting the following conditions in the electrospray device, coat graphene oxide onto the supporting substrate.

Table 1

In the present invention, since a graphene oxide dispersion mixed with 1 um-sized graphene oxide and 50-um sized graphene oxide is used for coating to increase the coating rate of the graphene oxide layer on the supporting substrate, it is possible to bring to reduce the peel strength of the peel layer.

In addition, by using an electrospray device to coat graphene oxide, there is an advantage of eliminating the existing coating process of a cationic polymer electrolyte solution before forming the graphene oxide layer. In addition, since a cationic polymer layer is not formed, there is an advantage that reduction in transmittance caused by the coated cationic polymer can be prevented.

Through the process described above, the formation of the peeling layer 20 according to the present invention is completed.

<Steps to form flexible substrate>

Next, a process for manufacturing the information display element according to the present invention will be described in detail.

After the aforementioned peeling layer manufacturing process is completed, a polyimide (PI) varnish is coated on the graphene oxide layer using an applicator until it reaches a thickness of 8um.

Heat treatment was performed at 100°C for 10 minutes, at 200°C for 30 minutes, and at 350°C for 30 minutes to improve imidization. At this time, preferably, the temperature rising rate in each temperature step is 5°C/min.

After coating the polyimide varnish and heating process, it is cooled for 3 hours to complete the formation of the flexible substrate 30 .

<Steps for manufacturing information display components>

After that, a layer 40 including a TFT layer, an organic light-emitting layer, and an encapsulation layer is formed, and a step of separating the support substrate 10 and the flexible substrate 30 is performed.

In the present invention, the step of separating the support substrate 10 and the flexible substrate 30 is performed by detaching the flexible substrate 30 from the release layer 20, thereby also completing the manufacturing process of the information display element according to the present invention.

Examples 2 and 3

In addition to adding 0.01% by weight of the graphene oxide dispersion of 50 μm in size and 0.01% by weight of the graphene oxide dispersion of 1 μm in size when preparing the graphene oxide dispersion in the <step of forming the peeling layer> in Example 1. Except that the step of mixing at a ratio of 5:5 was changed to mixing at a ratio of 7:3 and 8:2 respectively, the same process as in Example 1 was used, and thus Example 2 and Example 3 were implemented respectively.

Example 4

In addition to adding 0.01% by weight of the graphene oxide dispersion of 50 μm in size and 0.01% by weight of the graphene oxide dispersion of 1 μm in size when preparing the graphene oxide dispersion in the <step of forming the peeling layer> in Example 1. The same process as in Example 1 was used except that the step of mixing at a ratio of 5:5 was changed to use only 0.01% by weight of the 50um sized graphene oxide dispersion instead of 0.01% by weight of the 1um sized graphene oxide dispersion. , thus implementing Example 4.

Comparative Examples 1 and 2

In addition to adding 0.01% by weight of the graphene oxide dispersion of 50 μm in size and 0.01% by weight of the graphene oxide dispersion of 1 μm in size when preparing the graphene oxide dispersion in the <step of forming the peeling layer> in Example 1. Comparative Example 1 and Comparative Example 2 were implemented respectively by using the same process as Example 1 except that the step of mixing at a ratio of 5:5 was changed to mixing at a ratio of 3:7 and 2:8 respectively.

Comparative example 3

In addition to adding 0.01% by weight of the graphene oxide dispersion of 50 μm in size and 0.01% by weight of the graphene oxide dispersion of 1 μm in size when preparing the graphene oxide dispersion in the <step of forming the peeling layer> in Example 1. The same process as in Example 1 was used except that the step of mixing at a ratio of 5:5 was changed to use only 0.01% by weight of the 1um-sized graphene oxide dispersion and not 0.01% by weight of the 50um-sized graphene oxide dispersion. , thus implementing Comparative Example 3.

Experimental example 1

In order to measure the peel strength of the polyimide substrate, which is the flexible substrate 30 formed on the support substrate 10 prepared in the above example, the vertical peel strength was measured in a film adhesion testing device by the test method of standard ASTM D3330. The tester uses AMETEK (LS-1). The results are shown in Table 2.

Experimental example 2

In order to measure the light transmittance according to the examples, the light transmittance was measured after calibration using Eagle XG glass (Corning Company) with a width and length of 100 mm and a thickness of 0.5 mm respectively. Three measurements were performed on each sample and the average value was obtained. At this time, the transmittance measuring device used was DENSHOKU (NDH-7000). The results are shown in Table 2.

Table 2

As shown in Table 2 above, as the composition ratio of the 50um size graphene oxide dispersion liquid and the 1um size graphene oxide dispersion liquid is different, the peeling strength is also different, and the following effects can be observed: 50um size graphene oxide dispersion liquid The higher the liquid content, the more the coating rate increases, thereby reducing the peel strength.

This is because, for the smaller 1um-sized graphene oxide dispersion, since it has a size significantly smaller than the size of a water droplet, during the evaporation of water, only the edge of the water droplet is coated with graphene oxide. dispersion, so there is more overlap between the sheets, resulting in coating being only possible locally. In contrast, the larger graphene oxide dispersion of 50 μm has a size equivalent to the size of water droplets, so it can be applied when water droplets in which graphene oxide is dispersed are applied to a substrate. On the entire area of the water droplets, therefore, compared to the small-sized graphene oxide dispersion, the large-sized graphene oxide dispersion can be evenly coated on the entire area, thereby increasing the coating rate.

In addition, in terms of light transmittance, excellent light transmittance results were obtained in all examples.

Experimental example 3

In order to measure the peel strength of the polyimide substrate, which is the flexible substrate 30 formed on the support substrate 10 prepared in the comparative example, the vertical peel strength was measured in a film adhesion testing device according to the test method of ASTM D3330. The tester uses AMETEK (LS1). The results are shown in Table 3.

Experimental example 4

In order to measure the light transmittance according to the comparative example, Eagle XG glass (Corning Co., Ltd.) with a width and a length of 100 mm and a thickness of 0.5 mm was used for calibration and then the light transmittance was measured. Three measurements were performed on each sample and the average value was obtained. At this time, the transmittance measuring device used was DENSHOKU (NDH-7000). The results are shown in Table 3.

table 3

As shown in Table 3 above, with the different composition ratios of the 50um-sized graphene oxide dispersion and the 1um-sized graphene oxide dispersion, the peeling strength is also different. It can be observed that the following problems exist: 1um-sized graphene oxide dispersion The higher the liquid content, the higher the peel strength.

The specific preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-mentioned specific embodiments. The present invention can be modified without departing from the gist of the present invention as claimed in the claims. Those skilled in the art can implement various modified embodiments, and such modified embodiments should be included in the scope described in the claims.

Claims (16)

1. A method for manufacturing a release layer, characterized in that the method for manufacturing a release layer includes the following steps: Steps to prepare support substrate; and the step of forming a graphene oxide layer on the support substrate, The steps of forming the graphene oxide layer include: the step of coating graphene oxide dispersion on the support substrate, The graphene oxide dispersion liquid includes a first graphene oxide and a second graphene oxide, the size of the first graphene oxide is 50um, and the size of the second graphene oxide is 1um. 2. The method for manufacturing a peeling layer according to claim 1, wherein the step of coating the graphene oxide dispersion includes: The step of applying the graphene oxide dispersion liquid to the support substrate using electrospray under the conditions of a spray speed of 70 to 90 μL/min, an air pressure of 0.2 to 0.3 MPa, and a voltage of 9 kV or more. 3. The method for manufacturing a release layer according to claim 2, characterized in that: The spraying speed is 80 μL/min, the air pressure is 0.25MPa, and the voltage is 10kV. 4. The method for manufacturing a release layer according to claim 1, characterized in that: The concentration of the graphene oxide dispersion is 0.01 to 0.02% by weight. 5. The method for manufacturing a release layer according to claim 4, characterized in that: The concentration of the graphene oxide dispersion is 0.01% by weight. 6. The method for manufacturing a release layer according to claim 1, characterized in that: The graphene oxide dispersion liquid contains the first graphene oxide and the second graphene oxide in a ratio of 5:5 to 10:0. 7. A peeling layer, characterized in that: The peeling layer is manufactured according to the manufacturing method according to any one of claims 1 to 6. 8. A method of manufacturing an information display element, characterized in that the method of manufacturing an information display element includes the following steps: Steps to prepare support substrate; The step of forming a graphene oxide layer on the support substrate; the step of forming a flexible substrate on the graphene oxide layer; and the step of separating the support substrate and the flexible substrate, The steps of forming the graphene oxide layer include: the step of coating graphene oxide dispersion on the support substrate, The graphene oxide dispersion liquid includes a first graphene oxide and a second graphene oxide, the size of the first graphene oxide is 50um, and the size of the second graphene oxide is 1um. 9. The method for manufacturing an information display element according to claim 8, wherein the step of coating the graphene oxide dispersion includes: The step of applying the graphene oxide dispersion liquid to the support substrate using electrospray under the conditions of a spray speed of 70 to 90 μL/min, an air pressure of 0.2 to 0.3 MPa, and a voltage of 9 kV or more. 10. The method of manufacturing an information display element according to claim 9, characterized in that: The spraying speed is 80 μL/min, the air pressure is 0.25MPa, and the voltage is 10kV. 11. The manufacturing method of information display element according to claim 8, characterized in that: The concentration of the graphene oxide dispersion is 0.01 to 0.02% by weight. 12. The method of manufacturing an information display element according to claim 11, characterized in that: The concentration of the graphene oxide dispersion is 0.01% by weight. 13. The manufacturing method of information display element according to claim 8, characterized in that: The graphene oxide dispersion liquid contains the first graphene oxide and the second graphene oxide in a ratio of 5:5 to 10:0. 14. The method of manufacturing an information display element according to claim 8, wherein the step of forming the flexible substrate includes the following steps: Coating the graphene oxide layer is selected from the group consisting of polyimide, polyester, polyethylene, polycarbonate, polyethylene, polyvinyl ester, polyethersulfone, polyacrylate, and polyethylene naphthalate. and a step of any substance from the group consisting of polyethylene terephthalate; and The step of heating the coated substance. 15. The method of manufacturing an information display element according to claim 14, characterized in that: The step of heating the coated substance is to heat the coated substance from normal temperature to 350°C, and the temperature is increased by 5°C per minute. 16. An information display element, characterized in that: The information display element is manufactured according to the manufacturing method according to any one of claims 8 to 15.