A selective ink transfer printing method based on a liquid-like surface

Abstract

The application discloses a selective ink transfer printing method based on a liquid-like surface, which comprises the following steps: step 1, treating the surface of a substrate by using oxygen plasma; step 2, dissolving a reaction monomer in toluene containing saturated water; step 3, placing the substrate treated by oxygen plasma into the reaction solution in step 2 to form a PDMS molecular brush; step 4, performing pattern design on the surface of the PDMS molecular brush by using a mask process, and treating by using an alkali solution to selectively remove the molecular brush in the unprotected area so that the hydrophilic glass surface is restored; step 5, coating oily ink on the surface treated in step 4 to form a clear pattern; and step 6, directly contacting the ink surface with a target substrate, and applying pressure to transfer the ink. The method solves the problems of resolution, ink diffusion control and pattern uniformity in the existing printing technology, and improves the printing precision and applicability.

Description

Technical Field

[0001] This invention relates to a transfer printing method, specifically a method for selective ink transfer printing using a liquid-like surface. Background Technology

[0002] Currently, transfer printing technology for intricate patterns is crucial in fields such as micro-nano manufacturing, flexible electronics, and patterned printing. Existing technologies mainly include photolithography, flexible printing (such as offset and gravure printing), and inkjet printing, but all have certain limitations. For example, photolithography requires multiple exposure, development, and etching steps, making the process complex and costly, while also making it difficult to control the intricate patterning of organic inks; although flexible printing is suitable for large-area manufacturing, its limitations in plate-making precision lead to ink diffusion and blurred boundaries, making it difficult to meet high-resolution requirements; inkjet printing is limited by nozzle size and ink viscosity, making it difficult to control high-viscosity inks, affecting pattern uniformity. Furthermore, existing technologies struggle to precisely control the wetting and diffusion properties of inks during the printing process, resulting in problems such as blurred boundaries and uneven ink aggregation during transfer. Therefore, developing a simple, controllable, high-resolution transfer printing method suitable for complex patterns is of great significance.

[0003] Modifying flat solid surfaces with highly flexible molecular chains such as polydimethylsiloxane (PDMS) can impart super-lubricating properties similar to liquids; therefore, these surfaces are also known as liquid-like surfaces. When the PDMS molecular brush surface comes into contact with an organic liquid, the swelling effect of the organic liquid on the liquid-like molecules further increases the fluidity of the surface molecular chains and reduces the relaxation time of the chain ends, macroscopically exhibiting a static oleophilic and dynamic oleophobic effect. For oil-based inks on liquid-like surfaces, under static conditions, the ends of the PDMS molecular chains interact weakly with the oil-based ink; however, under dynamic contact, due to the entropic elastic response of the PDMS molecular chains and the solvent-induced swelling effect, the interface exhibits significant oleophobic properties. This intelligent response mechanism of "static wetting-dynamic repulsion," combined with controllable molecular chain relaxation dynamics, provides an ideal physicochemical platform for achieving controllable adhesion-release conversion of inks, further opening up innovative paths for the development of novel high-resolution transfer printing technologies. Summary of the Invention

[0004] The purpose of this invention is to provide a selective ink transfer printing method based on a liquid-like surface. This method achieves precise patterned deposition and efficient transfer of ink by covalently grafting liquid-like molecular brushes (such as PDMS) onto solid surfaces like glass, combined with selective etching using an alkaline solution. This method solves the problems of resolution, ink diffusion control, and pattern uniformity in existing printing technologies, and improves printing accuracy and applicability. It is suitable for micro / nano pattern preparation, electronic device manufacturing, and other high-precision patterning processes.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A selective ink transfer printing method based on a liquid-like surface includes the following steps:

[0007] Step 1: Treat the substrate surface with oxygen plasma for 0.5 to 20 minutes to form abundant hydroxyl (Si-OH) groups. The substrate may be glass, silicon wafer, metal, or polymer film, etc.

[0008] Step 2: Dissolve 0.01-1 mL of the reactant monomer in 40 mL of toluene containing saturated water. Stir the solution for 30-60 seconds, then let it stand at room temperature for 1-10 minutes before use. The concentration of the toluene containing saturated water is 0.024 mM, and the reactant monomer is dimethyldichlorosilane (DMDCS), 1,3-dichlorotetramethyldisiloxane (DCTDS), or 1,7-dichlorooctyltetrasiloxane (DCTTS).

[0009] Step 3: Place the oxygen plasma-treated matrix in the reaction solution of Step 2 for 0.5–60 min to form a PDMS molecular brush;

[0010] Step 4: Pattern design is performed on the surface of the PDMS molecular brush using a masking process, and the surface is treated with an alkaline solution for 0.1 to 30 minutes to selectively remove the unprotected areas of the molecular brush, restoring it to a hydrophilic glass surface. The alkaline solution is one of NaOH, KOH, and tetramethylammonium hydroxide (TMAH), with a mass concentration of 1 to 20%.

[0011] Step 5: Apply oil-based ink to the surface treated in step 4. Due to the difference in surface energy, the ink selectively gathers in the oleophilic area and does not adhere to the hydrophilic etched area, thereby forming a clear pattern.

[0012] Step 6: Directly contact the patterned ink surface with the target substrate and apply 1-20N pressure to transfer the ink. At the same time, control the contact time and detachment speed to improve the clarity of the pattern and reduce boundary diffusion. The target substrate can be plastic, metal, paper, etc.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. High-precision printing: Utilizing the selective wetting properties of liquid molecular brushes, patterned ink deposition with submicron precision (precision up to within 500nm) can be achieved, which is more than 5 times higher than traditional flexographic printing.

[0015] 2. Ink diffusion control: The ultra-low contact angle hysteresis of the PDMS molecular brush prevents ink from spreading at the edge of the pattern, improving the edge clarity by 40%.

[0016] 3. Simple process: Traditional photolithography requires 5 to 7 steps, while this invention reduces it to 3 to 4 steps, significantly reducing manufacturing costs and time.

[0017] 4. High reusability: The surface of the brush, which is covalently grafted with liquid-like molecules, can withstand more than 1,000 cycles of mechanical friction and chemical cleaning.

[0018] 5. Material Conservation and Environmental Protection: By reducing the use of chemical reagents such as photoresist and developer, environmental pollution can be reduced. Compared with traditional photolithography, it can save more than 30% of ink usage. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of a selective ink transfer printing method based on a liquid-like surface;

[0020] Figure 2 This is a schematic diagram illustrating the selective aggregation effect of ink in the hydrophilic and oleophilic regions.

[0021] Figure 3 To transfer printed product images. Detailed Implementation

[0022] The technical solution of the present invention will be further described below with reference to the embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0023] Example 1

[0024] Step 1: Treat the glass surface with oxygen plasma for 3 minutes.

[0025] Step 2: Dissolve 0.5 mL of dimethyldichlorosilane (DMDCS) in 40 mL of toluene containing saturated water (0.024 mM). Stir the solution for about 30 seconds and let it stand at room temperature for 5 minutes.

[0026] Step 3: Place the oxygen plasma-treated glass in the reaction solution for 30 minutes to finally form a PDMS molecular brush.

[0027] Step 4: Pattern the molecular brush surface using a masking process, and selectively remove unprotected areas of the molecular brush by treating with 1% NaOH for 20 minutes, restoring it to a hydrophilic glass surface. For inks, the contact angle of the PDMS molecular brush area is relatively small (e.g., ...). Figure 2 As shown on the left), the contact angle increases after NaOH treatment (e.g., Figure 2 (As shown on the right).

[0028] Step 5: Apply oil-based ink to the treated surface, then bring the patterned ink-coated surface into direct contact with the target substrate, applying 10N of pressure to transfer the ink. A microscope image of the transferred ink is shown below. Figure 3 As shown.

[0029] Example 2

[0030] Step 1: Treat the silicon wafer surface with oxygen plasma for 5 minutes to form abundant hydroxyl (Si-OH) groups.

[0031] Step 2: Dissolve 0.3 mL of DCTDS in 40 mL of toluene containing saturated water (0.024 mM), stir the solution for about 30 seconds, and then let it stand at room temperature for 3 minutes.

[0032] Step 3: Place the oxygen plasma-treated silicon wafer in the reaction solution for 50 minutes to finally form a PDMS molecular brush.

[0033] Step 4: Use a masking process to design patterns on the surface of the molecular brush, and treat it with 20% TMAH for 3 minutes to selectively remove the unprotected areas of the molecular brush, restoring it to a hydrophilic glass surface.

[0034] Step 5: Apply oil-based ink to the treated surface, bring the patterned ink surface into direct contact with the target substrate, and apply 20N pressure to transfer the ink.

[0035] Example 3

[0036] Step 1: Treat the surface of the aluminum sheet with oxygen plasma for 3 minutes.

[0037] Step 2: Dissolve 0.5 mL of 1,7-dichlorooctylmethyltetrasiloxane (DCTTS) in 40 mL of toluene containing saturated water (0.024 mM). Stir the solution for about 30 seconds and then let it stand at room temperature for 5 minutes.

[0038] Step 3: Place the oxygen plasma-treated glass in the reaction solution for 30 minutes to finally form a PDMS molecular brush.

[0039] Step 4: Use a masking process to design patterns on the surface of the molecular brush, and treat with 1% NaOH for 20 minutes to selectively remove the unprotected areas of the molecular brush, restoring it to a hydrophilic glass surface.

[0040] Step 5: Apply oil-based ink to the treated surface, bring the patterned ink surface into direct contact with the target substrate, and apply 1N pressure to transfer the ink.

[0041] Example 4

[0042] Step 1: Treat the PET film surface with oxygen plasma for 5 minutes to form abundant hydroxyl (Si-OH) groups.

[0043] Step 2: Dissolve 0.5 mL of DCTDS in 40 mL of toluene containing saturated water (0.024 mM), stir the solution for about 30 seconds, and then let it stand at room temperature for 3 minutes.

[0044] Step 3: Place the oxygen plasma-treated silicon wafer in the reaction solution for 50 minutes to finally form a PDMS molecular brush.

[0045] Step 4: Use a masking process to design patterns on the surface of the molecular brush, and treat it with 20% KOH for 5 minutes to selectively remove the unprotected areas of the molecular brush, restoring it to a hydrophilic glass surface.

[0046] Step 5: Apply oil-based ink to the treated surface, bring the patterned ink surface into direct contact with the target substrate, and apply 5N pressure to transfer the ink.

Claims

1. A selective ink transfer printing method based on a liquid-like surface, characterized in that... The method includes the following steps: Step 1: Treat the substrate surface with oxygen plasma for 0.5~20 min; Step 2: Dissolve 0.01~1 mL of the reactant monomer in 40 mL of toluene containing saturated water. Stir the solution for 30~60 s and let it stand at room temperature for 1~10 min. The reactant monomer is dimethyldichlorosilane, 1,3-dichlorotetramethyldisiloxane or 1,7-dichlorooctyltetrasiloxane. Step 3: Place the oxygen plasma-treated matrix in the reaction solution of Step 2 for 0.5~60 min to form a PDMS molecular brush; Step 4: Use a masking process to design patterns on the surface of the PDMS molecular brush, and treat with an alkaline solution for 0.1~30 min to selectively remove the unprotected areas of the molecular brush, restoring it to a hydrophilic glass surface; Step 5: Apply oil-based ink to the surface treated in step 4 to form a clear pattern; Step 6: Directly contact the patterned ink surface with the target substrate and apply pressure to transfer the ink.

2. The selective ink transfer printing method based on a liquid-like surface according to claim 1, characterized in that... The substrate is glass, silicon wafer, metal, or polymer film.

3. The selective ink transfer printing method based on a liquid-like surface according to claim 1, characterized in that... The concentration of the toluene containing saturated water is 0.024 mM.

4. The selective ink transfer printing method based on a liquid-like surface according to claim 1, characterized in that... The alkaline solution is one of NaOH, KOH, or tetramethylammonium hydroxide.

5. The selective ink transfer printing method based on a liquid-like surface according to claim 1 or 4, characterized in that... The mass concentration of the alkaline solution is 1-20%.

6. The selective ink transfer printing method based on a liquid-like surface according to claim 1, characterized in that... The target substrate is plastic, metal, or paper.

7. The selective ink transfer printing method based on a liquid-like surface according to claim 1, characterized in that... The pressure is 1~20N.

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