Laminating film for liquid crystal display and liquid crystal display backlight module

Abstract

The present invention discloses a bonding film for a liquid crystal display, which includes from top to bottom: an atomized layer film, a base film, a first prism layer film, a second prism layer film and a third prism layer film; the atomized layer film, the base film, the first prism layer film, the second prism layer film and the third prism layer film are sequentially bonded to each other by bonding adhesive. In addition, the present invention also discloses a liquid crystal display backlight module, which includes the bonding film for a liquid crystal display. The bonding film for a liquid crystal display of the present invention can achieve the effect of two brightness enhancement films and two diffusion films when the brightness reaches the effect of two brightness enhancement films and two diffusion films, and the shielding property can also meet the requirements of the liquid crystal display module, and the bonding film can directly contact the liquid crystal display panel glass to ensure no interference, no glare and up-to-standard visual effects, the scratch resistance meets the assembly requirements, and the stiffness of the final product can meet the requirements of large-size modules.

Description

Technical Field

[0001] The invention relates to a laminating film for a liquid crystal display and a backlight module of the liquid crystal display. Background Art

[0002] With the development of TFT-LCD liquid crystal display technology, the requirements for the size and stiffness of liquid crystal displays have gradually increased, the products have been required to be continuously thinned, and the assembly lines have been increasingly simplified for the assembly of membranes. As a result, the production and application of laminating films have also appeared in the market. The existing DOP, POP or P+P combined membranes are basically in the form of 1 composite or 2 light-enhancing + diffusion plates, and all structures require diffusion plates. In addition, these membranes need to be cut before they can be assembled and used. An extra layer of membrane requires one more cutting, which adds one more packaging cost, not only increasing the material cost, but also increasing the labor cost of assembling the membrane, resulting in an increase in the total cost of the product. Multiple packaging, transportation and assembly will also bring many problems. For example, during the packaging, transportation and assembly process, the product is prone to scratches, foreign matter, etc. The adverse effects caused by the previous operation will lead to a decrease in the production and assembly yield in subsequent operations, and ultimately still cause the cost to remain high. Therefore, the existing backlight modules and related optical film product solutions lack solutions that can not only ensure that the final product effect meets the requirements, improve brightness, anti-interference, scratch resistance, meet the stiffness requirements of large-size applications, etc., but also reduce costs, thereby achieving widespread application. Summary of the invention

[0003] The present invention overcomes the above-mentioned deficiencies of the prior art and provides a laminating film for a liquid crystal display and a liquid crystal display backlight module.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] A laminating film for a liquid crystal display comprises, from top to bottom, an atomizing layer film, a base film, a first prism layer film, a second prism layer film and a third prism layer film; the atomizing layer film, the base film, the first prism layer film, the second prism layer film and the third prism layer film are sequentially laminated to each other by laminating adhesive.

[0006] Preferably, the haze layer film comprises a polarizing film, and the upper surface of the polarizing film has a haze coating layer with a haze of more than 80%.

[0007] Preferably, the atomized coating layer is composed of hydroxy acrylic resin.

[0008] Preferably, PMMA microbeads are dispersed in the atomized coating layer.

[0009] Preferably, the base film is a 50-100 μm optical grade chemically treated PET film.

[0010] Preferably, the first prism layer film includes a first prism structure layer including a plurality of first prisms arranged in series, and the second prism layer film includes a second prism structure layer including a plurality of second prisms arranged in series.

[0011] Preferably, the first prism extends along a first direction, the second prism extends along a second direction, and the second direction and the first direction are perpendicular to each other.

[0012] Preferably, the cross-sections of the first prism and the second prism are both isosceles triangles, wherein in the isosceles triangle cross-sections, the vertex angle is 89° to 91°, the length of the base is 60 to 80 μm, and the height is 30 to 40 μm.

[0013] Preferably, the first prism layer film further includes a first base film, and the first prism structure layer is arranged on the upper surface of the first base film; the second prism layer film further includes a second base film, and the second prism structure layer is arranged on the upper surface of the second base film.

[0014] Preferably, the third prism layer film includes a third base film and a third prism structure layer, the third prism structure layer is arranged on the upper surface of the third base film, the third prism structure layer includes a plurality of third prisms, protrusions and a substrate, and the third prisms and protrusions are arranged on the substrate at intervals.

[0015] Preferably, the third prism has a top edge and two bottom edges, the top edge of the third prism protrudes from the substrate, and there is a gap of 200-220 μm between the bottom edges of adjacent third prisms, and the protrusions are distributed in the gap.

[0016] Preferably, the cross section of the third prism is an isosceles triangle with a vertex angle of 89° to 91°, a base length of 60 to 80 μm, and a height of 30 to 40 μm.

[0017] Preferably, the distance between the top of the protrusion and the base is 2-5 μm.

[0018] Preferably, the protrusion and the base form a cross section with a side length of 10 to 50 μm.

[0019] Preferably, the production extension direction of the laminating film for a liquid crystal display is defined as a reference direction, and the third prism extends along the third direction, and the third direction forms an angle of 14° to 16° with the reference direction.

[0020] Preferably, sandblasting is used to form rough surfaces on the upper surfaces of the third prism and the protrusion.

[0021] Preferably, the third prism layer film further includes a back coating layer, which is disposed on the lower surface of the third base film and has a haze of more than 99%.

[0022] Preferably, the back coating layer comprises a hydroxy acrylic resin containing 30% to 60% by mass of titanium dioxide.

[0023] Another object of the present invention is to provide a liquid crystal display backlight module.

[0024] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0025] A liquid crystal display backlight module is characterized by comprising the laminating film for a liquid crystal display.

[0026] The present invention provides a laminating film for liquid crystal display, which adopts a five-layer functional laminating film, wherein the atomizing layer film has a polarizing function, and can polarize the S light perpendicular to the incident surface into the P light parallel to the incident surface, so as to achieve the effect of brightness gain; the base film can improve the overall stiffness of the laminating film, and solve the problem of abnormal winding of the atomizing layer film after the temperature rises during use; the first prism layer film and the second prism layer film have a continuously arranged prism structure, which can further improve the brightness; the third prism layer film has a more special prism structure, which includes prisms and protrusions arranged at intervals, so that the film not only has the effect of increasing brightness, but also has a certain atomization shielding effect. Therefore, the laminating film for liquid crystal display of the present invention can meet the requirements of liquid crystal display module in terms of shielding property when the brightness reaches the effect of two light-enhancing films and two diffusion films, and the laminating film can directly contact with the liquid crystal display panel glass to ensure no interference, no glare and up-to-standard visual effect, the scratch resistance meets the assembly requirements, and the stiffness of the final product can meet the requirements of large-size modules. Therefore, the laminating film of the present invention can significantly reduce production costs. The application of the laminating film can replace the "brightness enhancement + diffusion plate" in the existing product solution, so that the LCD backlight module using the laminating film for LCD can ensure shielding and brightness, and has commercial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of the laminating film for liquid crystal display in the embodiment of the present invention.

[0028] Figure 2 Schematic diagram of the structure of the first prism structure layer in an embodiment of the present invention.

[0029] Figure 3 Schematic diagram of the structure of the second prism structure layer in an embodiment of the present invention.

[0030] Figure 4a Schematic diagram of the angle between the first prism and the second prism when viewed from above the laminating film in an embodiment of the present invention.

[0031] Figure 4b Schematic diagram of the angle between the third prism and the production extension direction of the bonding film when viewed from above in an embodiment of the present invention.

[0032] Figure 5 Schematic diagram of the structure of the third prism structure layer in an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The present invention is described in detail below with reference to the accompanying drawings.

[0034] The present invention provides a bonding film for a liquid crystal display, which comprises from top to bottom: an atomized layer film, a base film, a first prism layer film, a second prism layer film and a third prism layer film; the atomized layer film, the base film, the first prism layer film, the second prism layer film and the third prism layer film are sequentially bonded to each other by bonding adhesive.

[0035] The laminating film for liquid crystal display in the present invention adopts the form of a five-layer laminating film, so that the shielding property of the laminating film meets the requirements, has a high brightness, and ensures no interference and glare. Finally, the stiffness of the laminating film product meets the requirements of large-size modules.

[0036] The atomized layer film includes a polarizing film, and the upper surface of the polarizing film has an atomized coating layer with a haze of more than 80%. The atomized coating layer is composed of hydroxy acrylic resin. PMMA microbeads are dispersed in the atomized coating layer. PMMA microbeads are transparent particles made of PMMA (polymethyl methacrylate) for brightening and scattering. Among them, the particle size of PMMA microbeads is 3 to 5 μm, and PMMA microbeads make the haze of the atomized coating layer reach more than 80%. The polarizing film has a polarizing function, which can polarize part of the lateral light source to a vertical incident plane to achieve the effect of brightness gain. In addition, according to the different requirements of the final product, the upper surface of the polarizing film can be coated with a coating liquid with different haze, so that the final bonding film has better shielding properties and improves the haze of the film.

[0037] The base film is a 50-100 μm optical grade chemically treated PET film. The base film can improve the stiffness of the atomized layer film and solve the problem of abnormal winding of the atomized layer film after the temperature rises during use. The base film can be pre-coated first, and a coating liquid composed of water-based polyurethane and curing agent with a mass ratio of (15-20):1 is coated on the upper and lower surfaces of the base film, and then a bonding adhesive is coated, which can increase the adhesion of the bonding adhesive to better bond the atomized layer film and the subsequent prism layer film together to meet the process stability of the bonding production. Therefore, while the base film increases the stiffness of the atomized layer film, it solves the problem of abnormal winding of the atomized layer film after the temperature rises, thereby ensuring the stability of the entire bonding film.

[0038] The first prism layer film includes a first prism structure layer including a plurality of first prisms arranged in series, and the second prism layer film includes a second prism structure layer including a plurality of second prisms arranged in series.

[0039] The first prism extends along a first direction, the second prism extends along a second direction, and the second direction and the first direction are perpendicular to each other.

[0040] The cross-sections of the first prism and the second prism are both isosceles triangles, wherein the vertex angle of the isosceles triangle cross-section is 89° to 91°, the length of the base is 60 to 80 μm, and the height is 30 to 40 μm. The first prism layer film and the second prism layer film have a prism structure, which can further improve the brightness.

[0041] The first prism layer film further includes a first base film, and the first prism structure layer is arranged on the upper surface of the first base film; the second prism layer film further includes a second base film, and the second prism structure layer is arranged on the upper surface of the second base film.

[0042] The third prism layer film includes a third base film and a third prism structure layer, the third prism structure layer is arranged on the upper surface of the third base film, the third prism structure layer includes a plurality of third prisms, protrusions and a base, and the third prisms and protrusions are arranged on the base at intervals. The third prism layer film has a relatively special prism structure, which includes prisms and protrusions, so that the film has the effect of increasing brightness, and the brightness is increased by more than 7%-10%; the presence of the protrusions makes the film have shielding properties, and increases its haze, and has a hazy shielding effect.

[0043] The third prism has a top edge and two bottom edges. The top edge of the third prism protrudes from the base. There is a gap between adjacent third prisms, and the protrusion is arranged on the gap.

[0044] The third prism has a top edge and two bottom edges. The top edge of the third prism protrudes from the substrate. There is a gap of 200 to 220 μm between the bottom edges of adjacent third prisms, and the protrusions are distributed in the gap. In the third prism layer, the third prisms are distributed on the substrate in a non-continuous arrangement, and the protrusions are distributed in the gaps formed between the third prisms. The cross section of the third prism is an isosceles triangle with a top angle of 89° to 91°, and the length of the base of the isosceles triangle is 60 to 80 μm and the height is 30 to 40 μm. Since the distance between the top edges of adjacent third prisms is greater than the distance between the two bottom edges of the third prism, that is, the distance between the top edges of adjacent third prisms is greater than the length of the base of the isosceles triangle cross section of the third prism, there is a gap of 200 to 220 μm between the bottom edges of adjacent third prisms, so that the protrusions are distributed in the gap.

[0045] In addition, the distance between the top of the protrusion and the base is 2 to 5 μm. A circular cross section with a diameter of 10 to 50 μm is formed between the protrusion and the base, or a cross section of any shape with a side length between 10 and 50 μm is formed between the protrusion and the base. The protrusion makes the bonding film have a certain shielding effect, so that its haze is controlled between 10% and 60%. Finally, the third prism structure layer is sandblasted to form a rough surface on the upper surface of the third prism and the protrusion, which has a shielding effect and can also increase its haze. Therefore, what is obtained on the third prism structure layer is a special prism structure that combines the two structures of light enhancement and diffusion, and has a brightening and atomizing effect.

[0046] The production extension direction of the laminating film for liquid crystal display is defined as the reference direction, and the third prism extends along the third direction, and the third direction forms an angle of 14° to 16° with the reference direction. In order to ensure better lamination in the future, the extension direction of the third prism on the third prism layer film is set to a certain deflection angle, which also solves the interference problem caused by the superposition of the three prism layers.

[0047] The third prism layer film also includes a back coating layer, which is arranged on the lower surface of the third base film, and the haze of the back coating layer reaches more than 99%. The components of the back coating layer include a hydroxy acrylic resin containing 30% to 60% titanium dioxide by mass. The back coating layer contains titanium dioxide, which can overcome the problem of LED light sources forming lamp shadows through the film layer. Therefore, under the joint action of the back coating layer and the atomization layer film, the third prism layer film of the laminated film has a higher haze and brightness, thereby enhancing the anti-interference property of the laminated film.

[0048] The first base film, the second base film and the third base film in the present invention are all common PET films for brightness enhancement.

[0049] The laminating film for liquid crystal display of the present invention can achieve the effect of two brightness enhancement films and two diffusion films while the shielding property can also meet the requirements of liquid crystal display module. The use of this laminating film significantly reduces the production cost and has commercial application value.

[0050] The present invention also provides a liquid crystal display backlight module, comprising the above-mentioned laminating film for liquid crystal display. The liquid crystal display backlight module obtained by the present invention not only has the brightness of two brightness enhancement films and two diffusion films at the same time, but also meets the requirements of liquid crystal display module in terms of shielding, can be in direct contact with the liquid crystal display panel glass, ensures no interference, no glare, and meets the visual effect standard, and the stiffness of the final product can meet the requirements of large-size modules.

[0051] Example 1

[0052] A laminating film 10 for a liquid crystal display, such as Figure 1As shown, from top to bottom, it includes: a haze layer film 100, a base film 200, a first prism layer film 300, a second prism layer film 400 and a third prism layer film 500. The haze layer film 100, the base film 200, the first prism layer film 300, the second prism layer film 400 and the third prism layer film 500 are sequentially bonded to each other by bonding adhesive.

[0053] The atomized layer film 100 includes a polarizing film 110, and the upper surface of the polarizing film 110 has an atomized coating layer with a haze of 80%. The atomized coating layer is composed of a hydroxy acrylic resin; and PMMA micro beads with a particle size of 3 to 5 μm are dispersed in the atomized coating layer. In this embodiment, the mass of the PMMA micro beads is 2.5% of the mass of the hydroxy acrylic resin. After the atomized coating treatment, the haze reaches 80%, so that the atomized layer film 100 has a high brightness and high shielding effect.

[0054] The base film 200 is a 50 μm optical grade chemically treated PET film. The upper and lower surfaces of the base film 200 are provided with bonding adhesive layers 210 and 220. The upper surface of the base film 200 is bonded to the lower surface of the polarizing film 110 through the bonding adhesive layer 210.

[0055] The first prism layer film 300 includes a first prism structure layer 310 and a first base film 320. The first prism structure layer 310 is disposed on the upper surface of the first base film 320. The first prism structure layer 310 is bonded to the lower surface of the base film 200 through the bonding adhesive layer 220. The first prism structure layer 310 is formed by a plurality of first prisms 311 arranged continuously. The first prisms 311 extend along a first direction. Figure 2 As shown, the cross section of the first prism 311 is an isosceles triangle with a vertex angle of 90°, a base length b1 of 70 μm, and a height h1 of 35 μm. Figure 2 The inner surface of the substrate extends along a first direction A.

[0056] The second prism layer film 400 includes a second prism structure layer 410 and a second base film 420. The second prism structure layer 410 is arranged on the upper surface of the second base film 420. The lower surface of the first base film 320 has a bonding adhesive layer (not shown in the figure) to bond the second prism structure layer 410 to the lower surface of the first base film 320. The second prism structure layer 410 is composed of a plurality of second prisms 411 arranged in series. The second prisms 411 extend along a second direction B, and the second direction B is perpendicular to the first direction A. Figure 3 As shown, the cross section of the second prism 411 is an isosceles triangle with a vertex angle of 90°, a base length b2 of 70 μm, and a height h2 of 35 μm. Figure 3 Extending along the second direction B.

[0057] The first prism 311 has a first top edge 3111 and two first bottom edges 3112 and 3113, and the second prism 411 has a second top edge 4111 and two second bottom edges 4112 and 4113. Figure 2 , 3 The bottom edges of adjacent first prisms 311 and the bottom edges of adjacent second prisms 411 overlap each other so that the first prisms and the second prisms are arranged continuously. Figure 4a It is shown that the projection line of the first top edge 3111 extends along the first direction A, and the projection line of the second top edge 4111 extends along the second direction B, and the first direction A of the first prism 311 and the second direction B of the second prism 411 are perpendicular to each other at 90°.

[0058] The third prism layer film 500 includes a third prism structure layer 510 and a third base film 520. The third prism structure layer 510 is disposed on the upper surface of the third base film 520. The third prism structure layer 510 includes a plurality of third prisms 511, protrusions 512 and a base 513. The third prisms 511 and the protrusions 512 are disposed on the base 513, and the protrusions 512 are distributed in the gaps between adjacent third prisms 511. Figure 5 As shown, the cross section of the third prism 511 is an isosceles triangle with a vertex angle of 90°, a base length b3 of 70 μm, and a height h3 of 35 μm. The second base film 420 is bonded to the third prism structure layer 510 via a bonding adhesive layer (not shown) on the lower surface of the second base film 420.

[0059] The third prism 511 includes a top edge 5111 and two bottom edges 5112 and 5113. The top edge 5111 of the third prism 511 protrudes from the base 513. The length of the interval between the top edges 5111 of adjacent third prisms 511 is 270 μm, and the length a1 of the gap between the two bottom edges of adjacent third prisms 511 is 200 μm. The two bottom edges 5112 and 5113 of the third prism 511 are arranged on the base 513, and the protrusions 512 are distributed in the gaps formed between the bottom edges of adjacent third prisms 511. A cross section with a side length of 10 to 50 μm and random size and shape is formed between the protrusion 512 and the base 513. The distance between the top of the protrusion 512 and the base 513 is between 2 and 5 μm and the size is randomly set.

[0060] The production extension direction of the final product of the laminating film for liquid crystal display 10 obtained by the present invention is defined as a reference direction M, such as Figure 4b As shown, the third prism 511 extends along the third direction C, and the third direction C forms an angle of 14° with the reference direction M. The upper surfaces of the third prisms and protrusions on the third prism structure layer are sandblasted to form rough surfaces.

[0061] The third prism layer film 500 further includes a back coating layer 530, which is disposed on the lower surface of the third base film 520. The back coating layer 530 has a haze of 99.3%. The back coating layer 530 includes a hydroxy acrylic resin containing 40% by mass of titanium dioxide.

[0062] Example 2

[0063] The laminating film 10 for a liquid crystal display comprises, from top to bottom, a haze layer film 100, a base film 200, a first prism layer film 300, a second prism layer film 400 and a third prism layer film 500. The haze layer film 100, the base film 200, the first prism layer film 300, the second prism layer film 400 and the third prism layer film 500 are sequentially laminated to each other by laminating adhesive.

[0064] The atomized layer film 100 includes a polarizing film 110, and the upper surface of the polarizing film 110 has an atomized coating layer with a haze of 85%. The atomized coating layer is composed of a hydroxy acrylic resin; and PMMA micro beads with a particle size of 3 to 5 μm are dispersed in the atomized coating layer. In this embodiment, the mass of the PMMA micro beads is 3% of the mass of the hydroxy acrylic resin. After the atomized coating treatment, the haze reaches 85%, so that the atomized layer film 100 has a high brightness and high shielding effect.

[0065] The base film 200 is an 80 μm optical grade chemically treated PET film. The upper and lower surfaces of the base film 200 are provided with bonding adhesive layers 210 and 220. The upper surface of the base film 200 is bonded to the lower surface of the polarizing film 110 through the bonding adhesive layer 210. In this embodiment, before the bonding adhesive layer is provided, the upper and lower surfaces of the base film 200 are chemically pretreated with a pre-coating liquid composed of an aqueous polyurethane and a curing agent in a mass ratio of 15:1 to enhance the adhesion of the bonding adhesive layers on the upper and lower surfaces thereof.

[0066] The first prism layer film 300 includes a first prism structure layer 310 and a first base film 320. The first prism structure layer 310 is disposed on the upper surface of the first base film 320. The first prism structure layer 310 is bonded to the lower surface of the base film 200 by a bonding adhesive layer 220. The first prism structure layer 310 is formed by a plurality of first prisms 311 arranged continuously. The first prisms 311 extend along a first direction. The cross section of the first prism 311 is an isosceles triangle with a vertex angle of 89°, and the length of the base side b1 is 60 μm and the height h1 is 30 μm.

[0067] The second prism layer film 400 includes a second prism structure layer 410 and a second base film 420. The second prism structure layer 410 is arranged on the upper surface of the second base film 420. The lower surface of the first base film 320 has a bonding adhesive layer (not shown in the figure) to bond the second prism structure layer 410 to the lower surface of the first base film 320. The second prism structure layer 410 is composed of a plurality of second prisms 411 arranged in a row. The second prisms 411 extend along a second direction, which is perpendicular to the first direction. The cross section of the second prism 411 is an isosceles triangle with a vertex angle of 91°, and the length b2 of the base side is 60μm and the height h2 is 30μm.

[0068] The first prism 311 has a first top edge 3111 and two first bottom edges 3112 and 3113, and the second prism 411 has a second top edge 4111 and two second bottom edges 4112 and 4113. The bottom edges of adjacent first prisms 311 and adjacent second prisms 411 overlap each other so that the first prism and the second prism are arranged continuously. The projection line of the first top edge 3111 extends along the first direction A, and the projection line of the second top edge 4111 extends along the second direction B; the production extension direction of the final product of the adhesive film 10 for liquid crystal display obtained by the present invention is defined as the reference direction M. In this embodiment, the first direction A of the first prism 311 forms an angle of 135° with the reference direction M, and the second direction B of the second prism 411 forms an angle of 45° with the reference direction M. Then, the first direction A of the first prism 311 and the second direction B of the second prism 411 are perpendicular to each other at 90°.

[0069] The third prism layer film 500 includes a third prism structure layer 510 and a third base film 520. The third prism structure layer 510 is arranged on the upper surface of the third base film 520. The third prism structure layer 510 includes a plurality of third prisms 511, protrusions 512 and a base 513. The third prisms 511 and the protrusions 512 are arranged on the base 513, and the protrusions 512 are unevenly distributed in the gaps between adjacent third prisms 511. The cross section of the third prism 511 is an isosceles triangle with a vertex angle of 90°, and the length b3 of the base side is 60μm and the height h3 is 30μm. The second base film 420 is bonded to the third prism structure layer 510 through a bonding adhesive layer (not shown in the figure) on the lower surface of the second base film 420.

[0070] The third prism 511 includes a top edge 5111 and two bottom edges 5112 and 5113. The top edge 5111 of the third prism 511 protrudes from the base 513. The length of the interval between the top edges 5111 of adjacent third prisms 511 is 270 μm, and the length a1 of the gap between the two bottom edges of adjacent third prisms 511 is 210 μm. The two bottom edges 5112 and 5113 of the third prism 511 are arranged on the base 513, and the protrusions 512 are distributed in an irregular manner on the gap formed between the bottom edges of adjacent third prisms 511. A circular cross-section with a diameter of 10 to 50 μm and random size is formed between the protrusion 512 and the base 513. The distance between the top of the protrusion 512 and the base 513 is between 2 and 5 μm, and the distance size is randomly set.

[0071] The production extension direction of the final product of the laminating film for liquid crystal display 10 obtained by the present invention is defined as a reference direction M, and the third prism 511 extends along the third direction C, and the third direction C forms an angle of 15° with the reference direction M. The upper surfaces of the third prisms and protrusions on the third prism structure layer are sandblasted to form a rough surface.

[0072] The third prism layer film 500 further includes a back coating layer 530, which is disposed on the lower surface of the third base film 520. The back coating layer 530 has a haze of 99%. The back coating layer 530 includes a hydroxy acrylic resin containing 30% by mass of titanium dioxide.

[0073] Example 3

[0074] The laminating film 10 for a liquid crystal display comprises, from top to bottom, a haze layer film 100, a base film 200, a first prism layer film 300, a second prism layer film 400 and a third prism layer film 500. The haze layer film 100, the base film 200, the first prism layer film 300, the second prism layer film 400 and the third prism layer film 500 are sequentially laminated to each other by laminating adhesive.

[0075] The atomized layer film 100 includes a polarizing film 110, and the upper surface of the polarizing film 110 has an atomized coating layer with a haze of 85%. The atomized coating layer is composed of a hydroxy acrylic resin; and PMMA micro beads with a particle size of 3 to 5 μm are dispersed in the atomized coating layer. In this embodiment, the mass of the PMMA micro beads is 4% of the mass of the hydroxy acrylic resin. After the atomized coating treatment, the haze reaches 90%, so that the atomized layer film 100 has a high brightness and high shielding effect.

[0076] The base film 200 is a 100 μm optical grade chemically treated PET film. The upper and lower surfaces of the base film 200 are provided with bonding adhesive layers 210 and 220. The upper surface of the base film 200 is bonded to the lower surface of the polarizing film 110 through the bonding adhesive layer 210. In this embodiment, before the bonding adhesive layer is provided, the upper and lower surfaces of the base film 200 are chemically pretreated with a pre-coating liquid composed of an aqueous polyurethane and a curing agent in a mass ratio of 18:1 to enhance the adhesion of the bonding adhesive layers on the upper and lower surfaces thereof.

[0077] The first prism layer film 300 includes a first prism structure layer 310 and a first base film 320. The first prism structure layer 310 is disposed on the upper surface of the first base film 320. The first prism structure layer 310 is bonded to the lower surface of the base film 200 through the bonding adhesive layer 220. The first prism structure layer 310 is formed by a plurality of first prisms 311 arranged continuously. The first prisms 311 extend along a first direction A. The cross section of the first prism 311 is an isosceles triangle with a vertex angle of 90°, and the base side length b1 is 80 μm and the height h1 is 40 μm.

[0078] The second prism layer film 400 includes a second prism structure layer 410 and a second base film 420. The second prism structure layer 410 is disposed on the upper surface of the second base film 420. The lower surface of the first base film 320 has a bonding adhesive layer (not shown in the figure) to bond the second prism structure layer 410 to the lower surface of the first base film 320. The second prism structure layer 410 is formed by a plurality of second prisms 411 arranged continuously. The second prisms 411 extend along a second direction B, and the second direction B is perpendicular to the first direction A. The cross section of the second prism 411 is an isosceles triangle with a vertex angle of 91°, and the length b2 of the base side is 80 μm and the height h2 is 35 μm.

[0079] The first prism 311 has a first top edge 3111 and two first bottom edges 3112 and 3113, and the second prism 411 has a second top edge 4111 and two second bottom edges 4112 and 4113. The bottom edges of adjacent first prisms 311 and adjacent second prisms 411 overlap with each other so that the first prisms and the second prisms are arranged continuously. The projection line of the first top edge 3111 extends along the first direction A, and the projection line of the second top edge 4111 extends along the second direction B. The first direction A and the second direction B are perpendicular to each other at 90 degrees.

[0080] The third prism layer film 500 includes a third prism structure layer 510 and a third base film 520. The third prism structure layer 510 is arranged on the upper surface of the third base film 520. The third prism structure layer 510 includes a plurality of third prisms 511, protrusions 512 and a base 513. The third prisms 511 and the protrusions 512 are arranged on the base 513, and the protrusions 512 are distributed in the gaps between adjacent third prisms 511. The cross section of the third prism 511 is an isosceles triangle with a vertex angle of 89°, and the length b3 of the base side is 80μm and the height h3 is 40μm. The second base film 420 is bonded to the third prism structure layer 510 through a bonding adhesive layer (not shown in the figure) on the lower surface of the second base film 420.

[0081] The third prism 511 includes a top edge 5111 and two bottom edges 5112 and 5113. The top edge 5111 of the third prism 511 protrudes from the base 513. The spacing between the top edges 5111 of adjacent third prisms 511 is 300 μm, and the length of the gap a1 between the two bottom edges of adjacent third prisms 511 is 220 μm. The two bottom edges 5112 and 5113 of the third prism 511 are arranged on the base 513, and the protrusions 512 are distributed in the gaps formed between the bottom edges of adjacent third prisms 511. A cross section with a side length of 10 to 50 μm and random size and shape is formed between the protrusion 512 and the base 513. The distance between the top of the protrusion 512 and the base 513 is between 2 and 5 μm, and the distance is randomly set.

[0082] The production extension direction of the laminating film 10 for a liquid crystal display is defined as a reference direction M. The third prism 511 extends along the third direction C, and the third direction C forms an angle of 16° with the reference direction M. The upper surfaces of the third prisms and the protrusions on the third prism structure layer are sandblasted to form rough surfaces.

[0083] The third prism layer film 500 further includes a back coating layer 530, which is disposed on the lower surface of the third base film 520. The back coating layer 530 has a haze of 99.5%. The back coating layer 530 includes a hydroxy acrylic resin containing 60% by mass of titanium dioxide.

[0084] Comparative Example 1

[0085] The backlight module of the comparative example 1 includes, from top to bottom, a first high-transmittance diffuser, a common POP and a second high-transmittance diffuser.

[0086] Among them, the first high-transmittance diffusion and the second high-transmittance diffusion: the haze and transmittance both reach 89%.

[0087] Ordinary POP: It includes two layers of prism film, the base film of each layer is 125μm optical grade PET film, the distance between adjacent top edges in the prism structure is 70μm, the prism height is 30μm, and the prism cross section is a right-angled isosceles triangle. The prism structures in the two layers of prism film extend in the same direction.

[0088] The backlight modules of Examples 1 to 3 and Comparative Example 1 are compared, using an edge-entry backlight, and the backlight film test structure (from bottom to top): reflector, light bar, light guide plate, test laminated film; the comparison results are shown in Table 1.

[0089] Table 1

[0090]

[0091] Description of the test method:

[0092] 1. Backlight module brightness test: Turn on the backlight, wait for the backlight source to stabilize, put in the test film under normal working current and voltage, use SR-3A equipment to test the brightness of 9 points, and take the average value.

[0093] 2. Backlight module viewing angle test: Turn on the backlight, wait for the backlight source to stabilize, then put in the test film. Under normal working current and voltage, use the SR-3A device to test the single-point brightness and the brightness at different angles. The angle that is higher than and closest to one-third of the single-point brightness is taken as the viewing angle value.

[0094] 3. Visual effect after the backlight module covers the LCD screen: LCD screen normal working brightness, WRGB four colors (main white field) visual observation at different angles.

[0095] 4. Upper prism scratch resistance test: Use 40% haze back coating as friction material, fix the friction surface upward on the flat glass, place the test object with the surface coating facing downward on the friction material, and make the prism peak direction perpendicular to the moving direction. Place a protective film on the back of the test object, and place a load weight on the protective film. Pull out the test object at a uniform speed and observe it under a three-wavelength lamp or a microscope. The maximum weight without obvious scratches is the test data.

[0096] It can be seen from Table 1 that under DLED backlight, compared with the laminating film for liquid crystal display of the present invention and two high-transmittance upper and lower diffusion films plus ordinary POP, Examples 1 to 3 of the present invention are superior to Comparative Example 1 in terms of brightness, viewing angle and scratch resistance; that is, the laminating film for liquid crystal display of the present invention can ensure that the backlight module achieves the effect of two brightness enhancement films plus two diffusion films, or even better than the effect, and the shielding property can meet the requirements of the liquid crystal display module, and can be in direct contact with the liquid crystal display panel glass to ensure no interference, no glare, and the visual effect meets the standard. Finally, the scratch resistance meets the assembly requirements.

[0097] The embodiments of the present invention are only used to illustrate the present invention and do not constitute a limitation on the scope of the claims. Other substantially equivalent substitutes that can be thought of by those skilled in the art are all within the protection scope of the present invention.

Claims

1. A laminating film for a liquid crystal display, characterized in that: From top to bottom, it includes: an atomized layer film, a base film, a first prism layer film, a second prism layer film and a third prism layer film; the atomized layer film, the base film, the first prism layer film, the second prism layer film and the third prism layer film are sequentially bonded to each other by bonding adhesive. The atomized layer film includes a polarizing film, The first prism layer film includes a first prism structure layer, the first prism structure layer includes a plurality of first prisms arranged continuously, the second prism layer film includes a second prism structure layer, the second prism structure layer includes a plurality of second prisms arranged continuously, the first prisms extend along a first direction, the second prisms extend along a second direction, and the second direction and the first direction are perpendicular to each other, The third prism layer film includes a third base film and a third prism structure layer, wherein the third prism structure layer is arranged on the upper surface of the third base film, and the third prism structure layer includes a plurality of third prisms, protrusions and a base, wherein the third prisms and protrusions are arranged on the base at intervals. The third prism has a top edge and two bottom edges, the top edge of the third prism protrudes from the substrate, and there is a gap of 200-220 μm between the bottom edges of adjacent third prisms, the protrusions are distributed in the gap, and the cross section of the third prism is an isosceles triangle with a top angle of 89°-91°, a bottom side length of 60-80 μm and a height of 30-40 μm. The distance between the top of the protrusion and the base is 2 to 5 μm, and the protrusion and the base form a cross section with a side length of 10 to 50 μm. The production extension direction of the laminating film for a liquid crystal display is defined as a reference direction, and the third prism extends along the third direction, and the third direction forms an angle of 14° to 16° with the reference direction.

2. The laminating film for a liquid crystal display according to claim 1, characterized in that: The upper surface of the polarizing film is provided with an atomized coating layer with a haze of more than 80%, the atomized coating layer is composed of hydroxy acrylic resin, and PMMA micro beads are dispersed in the atomized coating layer.

3. The laminating film for a liquid crystal display according to claim 1, characterized in that: The base film is a 50-100 μm optical grade chemically treated PET film.

4. The laminating film for a liquid crystal display according to claim 1, characterized in that: The third prism layer film also includes a back coating layer, which is arranged on the lower surface of the third base film. The back coating layer makes its haze reach more than 99%, and the back coating layer includes a hydroxy acrylic resin containing 30% to 60% by mass of titanium dioxide.

5. A liquid crystal display backlight module, characterized in that: The present invention comprises the laminating film for liquid crystal display according to any one of claims 1 to 4.

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