TWM506699U - Composite film - Google Patents

Abstract

A composite film including a substrate, a transparent layer and an adhesive layer is provided, wherein the substrate has a first surface and a second surface opposite to the first surface, and the first surface has a concave-convex structure formed thereon. The transparent layer is disposed over the concave-convex structure of the first surface, and has at least two kinds of particles. The adhesive layer is disposed over the second surface.

Description

Composite film

This creation relates to a film, especially a composite film with a composite function.

With the rapid development of technology, users spend more and more time working, learning or playing through various electronic devices. Taking mobile communication devices as an example, their touch screens are prone to oil stains after prolonged use, or Inadvertently rubbing hard objects causes scratches and fine lines. In addition, the light source used in various electronic devices (such as a cold cathode tube CCFL or a light-emitting diode LED) generates short-wavelength blue light and ultraviolet light, and the user may easily cause eye damage by watching the screen for a long time.

In order to solve the above problems, a screen film of many electronic devices has been provided on the market, and FIG. 1 is a schematic cross-sectional view of a screen film having a multilayer structure. As shown in FIG. 1 , the screen film 1 mainly comprises: a substrate 10 of a biaxially stretched polyester film (PET film); a blue light treatment layer 14 and an anti-glare treatment layer which are sequentially formed on one side surface of the substrate 10; 11 (ANTI-GLARE layer, AG layer) and surface hardness-strengthening layer 12 (Hard-coating layer, HC layer); and a bonding layer 13 formed on the other side surface of the substrate 10.

The above-mentioned screen film 1 is applied multiple times (such as printing, plating, attaching, Spraying, etc., different materials to form a multilayer structure, thereby making the screen film 1 achieve various functions of scratch resistance, blue light filtering and anti-glare. However, the multiple coating process not only extends the manufacturing time of the product, but also increases the manufacturing cost. Secondly, the materials forming the layers comprise resins, particles and solvents of different surface properties. In the process of coating of a large area, the surface properties between the substrate and the materials of the layers, such as surface tension, hydrophilicity, oleophobicity, etc. The difficulty in forming a multilayer structure is increased, and a poorly stacked multilayer structure is prone to generation of bubbles, so that product yield cannot be improved. Moreover, even if a multilayer stack structure is formed, the uniformity of particle distribution in each layer and the adhesion of the multilayer stack structure are also lowered due to differences in surface properties of various materials, resulting in loss of various functions of the screen film and shortening of service life.

Therefore, how to solve the above problems and provide a composite film with excellent composite function and service life is the purpose of developing the creation.

The present invention provides a composite film comprising a substrate, a light transmissive layer and an adhesive layer, the substrate having a first surface and a second surface opposite to each other, wherein the first surface is formed with a concave-convex structure, and the light transmissive layer is formed The light transmissive layer contains at least two complex particles on the concave and convex structure of the first surface, and the adhesive layer is formed on the second surface.

In the composite film of the present invention, since the first surface of the substrate is formed with a concave-convex structure, the light-transmitting layer having a composite function is formed on the uneven structure, thereby enhancing the adhesion strength of the light-transmitting layer to the substrate, thereby effectively extending the composite The composite function and service life of the membrane.

1‧‧‧screen film

4,5‧‧‧Composite film

10,20,30,40,50‧‧‧Substrate

11‧‧‧Anti-glare treatment layer

12‧‧‧Surface hardness strengthening layer

13‧‧‧Fitting layer

14‧‧‧Blue light treatment layer

41, 51‧‧‧Transparent layer

42,52‧‧‧Adhesive layer

43,53‧‧ ‧ protective layer

44,54‧‧‧Fractal layer

201,301,401,501‧‧‧ first surface

202, 302, 402, 502‧‧‧ second surface

203,203’‧‧‧Roughened structure

303, 303', 304, 304', 403, 503, 504 ‧ ‧ concave structure

303a‧‧‧Bumps

304a‧‧‧ Groove

411,412,511,512,513‧‧‧ particles

1 is a schematic cross-sectional view of a conventional screen film having a multilayer structure; FIGS. 2A and 2B are schematic cross-sectional views of a substrate for corona treatment; and FIGS. 3A and 3A' are drawings of a substrate in the composite film of the present invention. A schematic cross-sectional view of a concave-convex structure; FIGS. 3B and 3B' are schematic cross-sectional views showing another concave-convex structure of a substrate in the composite film of the present invention; and FIG. 4 is a schematic cross-sectional view showing an embodiment of the composite film of the present invention. And Figure 5 is a schematic cross-sectional view of another embodiment of the composite film of the present invention.

The embodiments of the present invention are described below by way of specific embodiments, and those skilled in the art can understand other advantages and effects of the present invention from the contents disclosed in the present specification. The present invention can also be implemented or applied by various other specific embodiments. The details of the present specification can also be modified and changed without departing from the spirit of the present invention.

In general, each layer in the above-mentioned screen film (ie, layers such as scratch-resistant, blue-light-proof, and anti-glare) contains particles of a specific material and components such as a resin, and a high surface tension is generated due to the molecular structure of each layer of materials, resulting in a gap. (GAP) is formed on the bonding surface between the layers. When light passes through the gaps in the layers, the film will have a "Newtonian ring" (the rainbow light), which will affect the clarity of the user's viewing of the screen image. In order to avoid the film "Newton In the case of the ring, it is now possible to form an anti-glare layer on a substrate such as a transparent polymer film using a material such as cerium oxide microparticles and a binder resin. On the other hand, in order to improve the adhesion strength between the anti-glare layer and the substrate, a corona treatment may be applied to the surface of the substrate in advance.

2A and 2B are schematic cross-sectional views of a substrate subjected to corona treatment. As shown in FIG. 2A, the substrate 20 has a first surface 201 and a second surface 202 opposite thereto. The first surface 201 is formed with a roughened structure 203 via corona treatment, and the roughened structure 203 can increase the first surface 201. The surface area serves to enhance the adhesion strength of various material layers (eg, anti-glare layers, not shown).

However, after the substrate 20 undergoes a temperature change, the roughened structure 203 formed on the first surface 201 of the substrate 20 via corona treatment is liable to change. As shown in FIG. 2B, the roughening structure 203 on the first surface 201 shown in FIG. 2A is converted into a flattened roughened structure 203' due to the thermal expansion and contraction effect of the substrate 20 due to the temperature change, and is relatively flat. The surface area of the roughened structure 203' is smaller than the surface area of the original roughened structure 203, and the reduction of the surface area leads to a decrease in the adhesion strength of various material layers or even peeling, thereby affecting the function and life of the film.

The present invention improves the surface properties and surface structure of the substrate to produce a composite film having excellent composite function and service life. 3A, 3A', 3B, and 3B' are schematic cross-sectional views showing the uneven structure of the two substrates in the composite film of the present invention.

The uneven structure of the substrate shown in Fig. 3A is composed of a plurality of bumps protruding from the first surface. As shown in FIG. 3A, the substrate 30 has a first surface 301 and a second surface 302 opposite thereto, wherein the first surface 301 is formed with Concave structure 303. As the substrate 30, various polymer films such as a polyolefin film, a polyamide film, a polyurethane film, or a polyester film can be used, but are not limited thereto. In the present embodiment, the substrate 30 is a biaxially stretched (also known as biaxially stretched) transparent polyethylene terephthalate (PET) film (polyester film), and "biaxial stretching" means longitudinal and transverse directions. Wherein "longitudinal" means the direction along the film forming direction of the film, and "transverse direction" means the direction perpendicular to the longitudinal direction and the film thickness direction, and the biaxially stretched polyester film has an isotropic mechanical strength and excellent hydrolysis resistance. .

The method of forming the uneven structure 303 includes: coating a modified material (for example, a mixture solution of an inorganic or organic polyoxyl molecule, a photocurable resin, an acrylic polymer, etc.) (for example, dip coating, bead coating, gravure printing, etc.) As for the first surface 301 of the substrate 30, the modifying material is dried (heated or illuminated) to form a plurality of bumps 303a protruding from the first surface. The surface property of the bump 303a is different from the surface property of the substrate 30 (for example, the substrate 30 is hydrophobic and the bump 303a is hydrophilic, or the substrate 30 has a small degree of stretch and the bump 303a has a large degree of stretch. The surface of the substrate 30 can have composite chemical and physical properties. While the particle size of the bump 303a is in the range of several tens of nanometers to several micrometers, the plurality of bumps 303a evenly distributed on the first surface 301 can greatly increase the surface area of the first surface 301. Thereby, the first surface 301 of the substrate 30 has composite surface chemical and physical properties and a greatly increased surface area, thereby enhancing the adhesion strength of the light transmitting layer (not shown) to the substrate 30.

The concave-convex structure 304 of the substrate 30 shown in Fig. 3B is composed of a plurality of grooves 304a recessed in the first surface 301. In the present embodiment, the method of forming the uneven structure 304 includes: softening the temperature of the material lower than the substrate 30 The degree (e.g., the softening temperature of PET) gradually heats the first surface 301 to form a plurality of slightly droplet-shaped grooves 304a. Both the heat-treatable first surface 301 and the uneven structure 304 are effectively improved in wettability and surface area, thereby enhancing the adhesion strength of the light-transmitting layer (not shown) to the substrate 30.

It is worth mentioning that the concave-convex structures 303 and 304 formed by the bumps 303a or the grooves 304a shown in FIGS. 3A and 3B have different surface properties even after undergoing thermal expansion and contraction due to temperature changes. The high surface area geometry, as shown in Figures 3A' and 3B', the relief structures 303' and 304' of the substrate 30 can remain substantially in their original shape to maintain the adhesion of the light-transmitting layer to the substrate 30. Thereby, the composite function and service life of the composite film are effectively extended.

Figure 4 is a schematic cross-sectional view showing one embodiment of the composite film of the present invention. As shown in FIG. 4, the composite film 4 includes a substrate 40, a light transmitting layer 41, and an adhesive layer 42. The substrate 40 has a first surface 401 and a second surface 402 opposite thereto, wherein the first surface 401 is formed with a concave-convex structure 403 (such as the bump shown in FIG. 3A or the groove shown in FIG. 3B). The light transmissive layer 41 is formed on the uneven structure 403 of the first surface 401, and the light transmissive layer 41 contains at least two kinds of plural particles 411, 412. Adhesive layer 42 is formed on second surface 402.

In the present embodiment, the substrate 40 of an appropriate thickness can be selected depending on the use of the composite film 4. If the composite film 4 is applied to a mobile communication device, the thickness of the substrate 40 is preferably between 50 and 200 micrometers (μm), for example, 50 μm, 75 μm, 100 μm, 125 μm or 188 μm, but not limited thereto. When the thickness of the substrate 40 is controlled within this range, the composite film 4 can exhibit excellent electrical insulation, moisture barrier properties, mechanical properties, and touch operability.

The light transmissive layer 41 can be formed on the uneven structure 403 by printing, plating, filming, spraying, or the like. The light transmissive layer 41 has a thickness of from 2 to 20 microns, such as from 2 to 5 microns, and for example from 5 to 10 microns. The light transmissive layer 41 mainly comprises at least two kinds of plural particles 411 and 412, a binder resin and a small amount of additives (such as a surfactant, a slip agent, etc.).

The particles 411 and 412 may be independently selected from at least two polymer particles of a group consisting of particles having an anti-glare function, particles having a scratch-resistant function, particles having a blue-light-absorbing function, and particles having a water-repellent antifouling function.

For example, the particles 411 having a larger particle diameter are particles having a function of filtering blue light, and the particles 412 having a smaller particle diameter are particles having an anti-glare function, and the particles 411 having a larger particle diameter are densely distributed. In the binder resin of the light layer 41, the particles 412 having a smaller particle size are densely distributed between the particles 411 having a larger particle diameter, and since the first surface 403 of the substrate 40 has a composite surface property and an increased surface area, The adhesive resin of the light-transmitting layer 41 and the particles 412 having a small particle diameter increase the adhesion strength to the substrate 40, and accordingly, the particles 411 having a large particle diameter also increase the adhesion strength to the substrate 40.

The various particles 411 and 412 can be obtained from polymer materials known to have anti-glare, blue-light, scratch-proof and the like (for example, polyacrylic resin, polystyrene resin, styrene-acrylic copolymer, polyethylene resin, Epoxy resin, polyoxyn epoxide resin, polyvinylidene fluoride resin and polyvinyl fluoride resin, blue light-absorbing dye molecules, ultraviolet absorbers, etc.), the surface of which may or may not be modified (for example, hydrophilic, Oleophobic, etc.).

The weight ratio of the particles 411 and 412 in the light-transmitting layer 41 is not particularly limited, and is preferably, for example, 0.1 to 20% by weight, for example, 0.5 to 10%. weight%. The particle size of the particles 411 and 412 is in the range of several tens of nanometers to several micrometers, for example, 20 nanometers to 5 micrometers, for example, 50 nanometers to 2 micrometers, and the average particle size is not more than the light transmission layer. The average thickness of 41 is preferably, for example, between 20 and 100%, and for example, 40 to 80% of the average thickness of the light-transmitting layer 41.

The binder resin in the light transmissive layer 41 may be selected from a hydrophobic resin such as a polyester resin, a polyether resin, an acrylic resin, an epoxy resin, but is not limited thereto.

The adhesive layer 42 may be selected from Pressure Sensitive Adhesives (PSA) such as an anthrone-based resin.

As shown in FIG. 4, the composite film 4 further includes a protective layer 43 and a release layer 44. The protective layer 43 is formed above the light transmissive layer 41 to prevent damage of the composite film 4 during transportation and storage. The release layer 44 is formed on the layer of the adhesive 42. When the user wants to attach the composite film 4 of the present invention to the screen surface of the electronic device, only the release layer 44 is peeled off, and the adhesive layer 43 is adhered to the electronic device. The surface of the screen is peeled off and the protective layer 43 is peeled off to complete the attachment of the composite film 4.

In the present embodiment, the adhesion strength of the light-transmitting layer 41 is increased by the uneven structure 403 of the substrate 40, and the composite film 4 of the present invention can have not only light but the manner of stacking the multilayer structure on the substrate in the prior art. Regular reflection and moderate diffusion can fully achieve the effects of combining glare, blue light absorption and ultraviolet light absorption, and further reduce the thickness of the film to further improve the user experience when using the electronic device.

Figure 5 is a schematic cross-sectional view showing another embodiment of the composite film of the present invention. As shown in FIG. 5, the composite film 5 comprises a substrate 50, a light transmitting layer 51, and a paste. The primer layer 52, the protective layer 53, and the release layer 54. The substrate 50 has a first surface 501 and a second surface 502 opposite thereto, wherein the first surface 501 is formed with a concave-convex structure 503, and the second surface 502 is further formed with a concave-convex structure 504. The light transmissive layer 51 is formed on the concave-convex structure 503 of the first surface 501, and the light transmissive layer 51 contains three kinds of particles 511, 512 and 513 having different functions. Adhesive layer 52 is formed on relief structure 504 of second surface 502.

In the present embodiment, the first surface 501 and the second surface 502 of the substrate 50 are formed with the uneven structures 503 and 504, thereby enhancing the adhesion strength and adhesion of the light-transmitting layer 51 and the adhesive layer 52 to the substrate 50. The fastness is used to further extend the composite function and service life of the composite film 5.

It is worth mentioning that, in the present creation, since the concave-convex structure of the substrate can effectively improve the adhesion strength of the light-transmitting layer to the substrate, even if a plurality of light-transmitting layers are stacked on the substrate to form a composite film, or two pieces are The light-transmitting layers of the composite film shown in Fig. 4 are bonded to each other to form a composite film, and the multilayer light-transmitting layer can maintain the adhesion strength to the substrate and the functions of the respective light-transmitting layers.

In summary, in the composite film of the present invention, since the first surface of the substrate is formed with a concave-convex structure, a light-transmissive layer having a composite function is formed on the uneven structure, thereby enhancing the adhesion strength of the light-transmitting layer to the substrate 30. Thereby, the composite function and service life of the composite film are effectively extended.

The above examples are merely illustrative of the composite film of the present invention and are not intended to limit the creation. Any person skilled in the art can modify and change the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this creation shall be in the scope of the patent application attached to this case.

4‧‧‧Composite film

40‧‧‧Substrate

41‧‧‧Transparent layer

42‧‧‧Adhesive layer

43‧‧‧Protective layer

44‧‧‧Fractal layer

401‧‧‧ first surface

402‧‧‧ second surface

403‧‧‧ concave structure

411,412‧‧‧ particles

Claims (10)

A composite film comprising: a substrate having an opposite first surface and a second surface, wherein the first surface is formed with a concave-convex structure; the light-transmitting layer is formed on the concave-convex structure of the first surface, and the transparent The optical layer contains at least two complex particles; and an adhesive layer is formed on the second surface. The composite film according to claim 1, wherein the substrate is a biaxially stretched polyester film. The composite film of claim 1, wherein the substrate has a thickness of from 50 to 200 microns. The composite film according to claim 1, wherein the uneven structure is composed of a plurality of bumps protruding from the first surface. The composite film of claim 4, wherein the surface properties of the bumps are different from the surface properties of the substrate. The composite film according to claim 1, wherein the uneven structure is composed of a plurality of grooves recessed in the first surface. The composite film of claim 1, wherein the light transmissive layer has a thickness of from 2 to 50 micrometers. The composite film according to claim 1, wherein the two plurality of particles are independently selected from particles having anti-glare function, particles having scratch resistance, particles having blue light filtering function, and water and antifouling functions. And at least two polymer particles in the group consisting of particles having a heat insulating function. The composite film according to claim 1, further comprising a protective layer and a release layer, wherein the protective layer is formed over the light transmissive layer, and the release layer is formed on the adhesive layer. The composite film according to claim 1, wherein the second surface is formed with a concave-convex structure, and the adhesive layer is formed on the concave-convex structure of the second surface.