Flexible printing plate with special microstructured printing surface layer

Abstract

The utility model discloses a flexible printing plate with special microstructure printing surface layer, including the reinforcing film layer, elastic resin layer and printing microstructure layer that set gradually from below to above, reinforcing film layer is overlaid by one or more layers PET film, the elastic resin layer adopts the polyurethane system photosensitive resin solidification of resistance polarity organic solvent, printing microstructure layer includes several micron level convex structure, its array arrangement, the convex structure three -dimensional direction of printing microstructure layer is "dome" shape, and the projection of array arrangement structure is several circular tangential or intersected arrangement in two -dimensional plane, and the dot arrangement line number of microstructure layer is 600 800. The structure of the utility model is convenient for ink to emit, and is evenly distributed on the printing material, can pass through the adjustment microstructure arrangement line number to adapt the demand of high PPI panel printing.

Description

Technical Field

[0001] This utility model relates to the field of high-precision printing technology. More specifically, this utility model relates to a flexible printing plate with a special microstructure printing surface layer. Background Technology

[0002] In the manufacturing of liquid crystal displays (LCDs), simply sandwiching liquid crystal between two glass substrates makes it difficult to achieve a uniform molecular arrangement. The alignment film, a layer within the liquid crystal cell that contacts the liquid crystal, can be further processed through friction or UV light to ensure a uniform and ordered arrangement of liquid crystal molecules, achieving light modulation within the liquid crystal. Liquid crystal alignment film printing involves using precision printing techniques (such as R2R photosensitive resin plate printing) to coat the surface of the LCD substrate with alignment film materials such as polyimide (PI), followed by high-temperature curing and friction or photoalignment treatment to form a microstructure that controls the orientation of liquid crystal molecules. Ensuring the oriented alignment of liquid crystal molecules directly affects the display's viewing angle, response speed, contrast ratio, and other performance characteristics.

[0003] The main technical challenge in manufacturing flexible printing plates for alignment films lies in the pattern of their surface layer, which needs to accurately reproduce micron-level fine lines. In existing technologies, the microstructure of the printing plate surface layer is processed using photolithography (CN101107134A) and embossing transfer (CN103144458B), each with its own advantages. Patent CN101107134A discloses an aniline-based photosensitive resin that, through exposure to a film negative, forms a regularly arranged dot pattern on the surface of the printing plate, with its microstructure surface exhibiting a "flat-top" shape (patent appendix). Figure 2 In actual printing, the dots come into contact with the LCD panel array substrate. The elastic deformation generated by the dots when in contact with the substrate affects the thickness of the alignment film, especially for array substrates with deep contact holes (LTPS, low-temperature polycrystalline silicon glass substrate). The smaller elastic deformation hinders the full release of PI ink contained in the grooves on the printing plate surface, preventing complete penetration of the contact holes and resulting in uneven alignment film thickness around the contact holes, forming printing pitting defects. Patent CN103144458B discloses a method for transferring micron-level patterns on the surface of PET (polyethylene terephthalate) film material to the surface of a printing plate during the photosensitive resin curing process using embossing transfer printing plate-making technology (patent appendix). Figure 3 and 4 The existing randomly distributed microstructure patterns have a surface ink storage capacity comparable to the halftone plates mentioned above, but for panels with high PPI (pixel density), the uniformity of the alignment film after printing is poor (highly dependent on printing machine parameters); secondly, for array substrates with deep contact holes, the printing effect around the contact holes is not very good. Utility Model Content

[0004] One objective of this invention is to provide a flexible printing plate with a special microstructure printing surface layer that facilitates ink extrusion and uniform distribution on the substrate. The microstructure arrangement line count (600-800) can be adjusted to meet the needs of high PPI panel printing.

[0005] To address the aforementioned technical problems, this utility model provides a flexible printing plate with a special microstructure printing surface layer, comprising, from bottom to top, a reinforcing film layer, an elastic resin layer, and a printed microstructure layer. The reinforcing film layer is composed of one or more layers of PET film, and the elastic resin layer is cured using a polyurethane-based photosensitive resin resistant to polar organic solvents. The printed microstructure layer includes several micron-sized protrusions arranged in an array. The protrusions of the printed microstructure layer are dome-shaped in three dimensions, and the projection of the arrayed structure onto a two-dimensional plane is a series of tangent or intersecting circles. The dot arrangement of the microstructure layer has a line count of 600-800.

[0006] Preferably, the height of the "dome"-shaped protrusions in the printed microstructure layer is 5-50 μm, and the bottom diameter of the protrusions is 20-70 μm.

[0007] Preferably, the height of the "dome"-shaped protrusions in the printed microstructure layer is 8-20 μm, and the bottom diameter of the protrusions is 25-50 μm.

[0008] Preferably, the line OB connecting the center points of the connected protrusions forms an angle α with the printing direction OA of the printing plate, where α is between 0 and 60°.

[0009] Preferably, the number of nodes adjacent to the microstructure layer nodes is 4 or 6.

[0010] Preferably, the four dots are arranged in a square; the six dots are arranged in a hexagon, corresponding to α being 45° or 60°.

[0011] Preferably, the PET film thickness is 100-300μm; and the hardness of the elastic resin layer is 35-55 Shore A.

[0012] Preferably, when the array of several protruding structures is arranged in a way that results in several intersecting circles when projected onto a two-dimensional plane, the overlapping portion of the intersection does not exceed 1 / 10 of the bottom diameter of the protruding structure.

[0013] This utility model has at least the following beneficial effects: 1. The printing plate of this utility model is suitable for printing liquid crystal alignment layers in liquid crystal displays, organic light-emitting films in organic EL displays, and electrode films in electronic devices. Compared with film dot matrix technology, its line count can reach over 700, making it more suitable for high PPI printing requirements.

[0014] 2. This utility model is made using embossing transfer printing process. Its microstructure outline is dome-shaped and regularly arranged. The elastic dome structure transitions from point contact to surface contact with the substrate during the actual printing process, which is conducive to the expulsion of ink from the grooves around the microstructure dots. This satisfies both printing uniformity and ensures the thickness of the alignment film.

[0015] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the cross-sectional structure of the printing plate of this utility model; Figure 2 A printing plate made using the film photolithography process; Figure 3 A printing plate made for the embossing transfer process; Figure 4 Printing plate two made for embossing transfer printing process; Figure 5 This is a schematic diagram of the embossed film surface structure in Embodiment 1 of this utility model; Figure 6 This is a 3D image of the embossed film surface in Embodiment 1 of this utility model; Figure 7 This is a schematic diagram of the embossed film surface structure in Embodiment 2 of this utility model; Figure 8 This is an elevation view and a surface outline view of the embossed film surface structure of this utility model.

[0017] Explanation of reference numerals in the attached figures: 1. Reinforcing film layer; 2. Elastic resin layer; 3. Printed microstructure layer. Detailed Implementation

[0018] To better understand the purpose, structure, and function of this utility model, the following detailed description is provided in conjunction with the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0019] It should be noted that in the description of this utility model, the terms "horizontal", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] like Figure 1As shown, this utility model provides a flexible printing plate with a special microstructure printing surface layer, comprising a reinforcing film layer 1, an elastic resin layer 2, and a printed microstructure layer 3 arranged sequentially from bottom to top. The reinforcing film layer is composed of one or more layers of PET film; the elastic resin layer is cured using a polyurethane-based photosensitive resin resistant to polar organic solvents such as NMP; the printed microstructure layer is formed by an embossed film with a micron-level dot pattern (a planar view of microstructure protrusions) through an embossing transfer process. Figure 6 and Figure 8 As shown, the printed microstructure layer comprises a densely arrayed array of several micrometer-sized spherical protrusions. These protrusions are dome-shaped in three dimensions, as... Figure 5 and Figure 7 As shown, its array arrangement structure is projected onto a two-dimensional plane as several circles arranged tangent to or intersecting each other.

[0021] The height of the "dome"-shaped protrusions in the printed microstructure layer is 5-50 μm, preferably 8-20 μm; the bottom diameter of the protrusions is 20-70 μm, preferably 25-50 μm. When the array arrangement of several protrusions is projected onto a two-dimensional plane as several intersecting circles, the overlapping portion of the intersection does not exceed 1 / 10 of the bottom diameter of the protrusions.

[0022] The line OB connecting the center points of the connected protruding structures forms an angle α with the printing direction OA of the printing plate, where α is between 0 and 60°.

[0023] The thickness of the reinforced PET film layer is approximately 100-300 μm, preferably 250 μm.

[0024] The hardness of the elastic resin layer is 35-55 shore A, preferably 40-44 shore A.

[0025] The number of dots in the microstructure layer is 600-800; the number of dots adjacent to the dots in the microstructure layer is 4 or 6, with 4 dots arranged in a regular quadrilateral or 6 dots arranged in a regular hexagon; the corresponding α is 45° or 60°.

[0026] Example 1 Adopting such Figure 5 and Figure 6 The embossed film shown has OA1 as the printing direction, OB1 as the microstructure arrangement direction, and α1 angle of 60°.

[0027] The embossed film is laid flat on the lower glass substrate of the plate-making machine. Liquid photosensitive resin is applied onto the embossed film through a slit ejector device, and then a reinforcing film is placed on top of the resin. The upper substrate of the lower plate-making machine is then pressed down, and the gap between the upper and lower substrates is controlled. The UV lamp on the lower substrate is turned on, and the plate is exposed for 30 minutes. After curing, the plate is inverted, the embossed film is peeled off, and the original plate is engraved, cleaned, and dried to obtain the alignment film printing plate.

[0028] Example 2 Adopting such Figure 7 The embossed film shown has OA2 as the printing direction, OB2 as the microstructure arrangement direction, and α2 angle as 45°.

[0029] The embossed film is laid flat on the lower glass substrate of the plate-making machine. Liquid photosensitive resin is applied to the embossed film through a slit ejector device, and then a reinforcing film is placed on top of the resin. The upper substrate of the lower plate-making machine is then pressed down, and the gap between the upper and lower substrates is controlled. The UV lamp on the lower substrate is turned on, and the plate is exposed for 30 minutes. After curing, the plate is inverted, the embossed film is peeled off, and the original plate is engraved, cleaned, and dried to obtain the alignment film printing plate.

[0030] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Although the embodiments of this utility model have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for this utility model, and other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, this utility model is not limited to the specific details and examples shown and described herein.

Claims

1. A flexible printing plate with a special microstructure printing surface layer, characterized in that, The device comprises, from bottom to top, a reinforcing film layer, an elastic resin layer, and a printed microstructure layer. The reinforcing film layer is composed of one or more layers of PET film. The elastic resin layer is cured with a polyurethane-based photosensitive resin resistant to polar organic solvents. The printed microstructure layer includes several micron-sized protrusions arranged in an array. The protrusions of the printed microstructure layer are dome-shaped in three dimensions. The projection of the arrayed structure onto a two-dimensional plane is several tangent or intersecting circles. The number of dots in the microstructure layer is 600-800.

2. The flexible printing plate with a special microstructure printing surface layer as described in claim 1, characterized in that, The height of the "dome"-shaped protrusions in the printed microstructure layer is 5-50 μm; the diameter of the bottom of the protrusions is 20-70 μm.

3. The flexible printing plate with a special microstructure printing surface layer as described in claim 2, characterized in that, The height of the "dome"-shaped protrusions in the printed microstructure layer is 8-20 μm; the diameter of the bottom of the protrusions is 25-50 μm.

4. The flexible printing plate with a special microstructure printing surface layer as described in claim 1, characterized in that, The line OB connecting the center points of the connected protruding structures forms an angle α with the printing direction OA of the printing plate, where α is between 0 and 60°.

5. The flexible printing plate with a special microstructure printing surface layer as described in claim 4, characterized in that, The number of nodes adjacent to the microstructure layer nodes is 4 or 6.

6. The flexible printing plate with a special microstructure printing surface layer as described in claim 5, characterized in that, Four dots are arranged in a square; six dots are arranged in a hexagon, corresponding to α of 45° or 60°.

7. The flexible printing plate with a special microstructure printing surface layer as described in claim 1, characterized in that, The PET film thickness is 100-300μm; the hardness of the elastic resin layer is 35-55 Shore A.

8. The flexible printing plate with a special microstructure printing surface layer as described in claim 2, characterized in that, When the projection of an array of protruding structures onto a two-dimensional plane is such that several circles intersect, the overlapping portion of the intersection does not exceed 1 / 10 of the bottom diameter of the protruding structure.

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