TW201331632A - Flexible optical film and method of manufacturing the same - Google Patents

Abstract

The present invention discloses a flexible optical film and method of manufacturing the same. The flexible optical film may comprise titanium dioxide and silicone; wherein titanium dioxide and silicone are mixed by 0.01-20 weight percentage. The flexible optical film has excellent flexibility and elasticity, and hence no bending mark will be formed by bending, folding or twisting. Also, the flexible optical film of the present invention applied in OLED backlight or lighting system has better optical characteristics and properties than a conventional optical film. When one or multiple types of fluorescence/phosphor powder is/are further added, the flexible optical film may have better optical characteristics, such as higher color rendering index.

Description

Flexible optical film and manufacturing method thereof

The present invention relates to an optical film, and more particularly to a flexible optical film and a method of manufacturing the same.

With the advancement and development of display technology, diffused and reflective optical films and plates play a critical role in the backlight system of liquid crystal display panels.

For most backlight systems, two important components are made from a polymer material, one for the membrane and the other for the sheet. They are primarily used to diffuse and/or reflect light on light guides (mobile phone devices, laptops and monitor screens) or directly from the light source itself (for some direct-lit backlight systems such as TV products).

The diffusion film for optics is a film material made of plastic, which is mainly formed by coating many tiny polymer particles on the acrylic plastic film substrate. For direct-lit backlight system applications, diffused sheets are typically made by mixing resin substrates into a filler. These diffusers or diffusers are important for direct-lit backlight systems because they must act to eliminate the effects of uneven light from different phase sources, while also using them to mask some optical defects, such as In addition to the uneven brightness of the moiré traces, etc., for a complete backlight module, there must be many precision optical diaphragms, another major task of the diffusion membrane or diffuser is to protect the upper The ruthenium under the diffuser, with a diffuser or diffuser, will provide a fairly good shield for this delicate and easily damaged optical component. In general, the biggest problem encountered with a diffuser film is the torsional deformation or crease of the diaphragm. This effect refers to the torsional deformation of the diaphragm itself after exposure to the light source after long-term use of the backlight system. The phenomenon will bring quite serious optical defect results to the entire backlight system; in addition, the scratches and peeling problems on the surface of the diffusion film are also frequently discussed in the backlight system and optical film defects. Experimental research has found that the key cause of these phenomena is the material properties of the optical diffusion film itself.

At the same time, the diffusion film commonly used in conventional optics is a hard ethylene terephthalate (PET) material. Therefore, when the diffusion film is bent, the PET material is hard, so that creases may occur, causing optical problems.

In the above, the conventional optical diffusion film or the like creates an optical problem due to creases. In other words, no one has disclosed any way to utilize the silicone and the additional treatment of its structure, so that the optical diffusion film can not affect its optical characteristics due to the crease caused by the bending.

The above disclosure of the present invention is merely intended to enhance the understanding of the background art of the present invention, and therefore, the above description contains prior art that does not constitute a hindrance to the present invention and is well known to those skilled in the art.

It is an object of the present invention to provide an optical film using silicone as a substrate; since silicone is an elastomer, when the optical film is bent, no crease occurs and the original shape and position are restored.

Another object of the present invention is to provide an optical film which is an optical film using silicone as a carrier and which has good flexural properties. When the terminal optical product requires a tortuous shape, its optical properties are not affected by the damage of the optical film.

The optical film of the present invention, wherein the technical concept of the crucible is to add titanium dioxide to an optical film based on silicone, so that it has a good refractive index.

Therefore, in order to achieve the above object, a method for manufacturing an optical film is provided, which may include: mixing titanium dioxide and silicone rubber into a mixture in a predetermined weight ratio; coating or printing the mixture on a substrate or pouring into a mold, and then Baking molding at a predetermined temperature; separating the shaped mixture from the substrate or mold.

Preferably, the predetermined weight ratio of the titanium dioxide and the silicone rubber may be 0.01 to 20%.

Wherein, before the tannin extract and the titanium dioxide are mixed in a predetermined weight ratio, the surface of the titanium dioxide may be subjected to a lipophilic treatment to improve the affinity of the titanium dioxide and the tannin to bond with each other.

Wherein, after the titanium dioxide and the tannin extract are mixed, the defoaming reaction under reduced pressure can be utilized to cause the mixture of the tannin and the titanium dioxide to be uniformly mixed.

According to the aspect of the present invention, when the mixture is coated or printed on a substrate, a vacuum degassing process can be performed.

According to another aspect of the present invention, when the mixture is poured into the mold, a vacuum degassing process can be performed.

Preferably, the predetermined temperature for baking the mixture of titanium dioxide and silicone is 50 to 150 °C.

Preferably, the time required to bake the mixture of titanium dioxide and silicone is about 30 minutes to 4 hours.

Preferably, the mixture of titanium dioxide and tannin can be poured into another mold of a different structure such that the optical film has a different surface structure.

Preferably, when the titanium dioxide and the tannin are mixed in a predetermined weight ratio, a predetermined weight percentage of the phosphor powder may be simultaneously added; wherein the phosphor powder may be yttrium aluminum garnet (YAG), nitride, niobate or sulfide. And the predetermined weight percentage may be 0.2 to 5%.

In addition, the present invention further provides a flexible optical film, which may comprise titanium dioxide and silicone, wherein the titanium dioxide and the silicone are mixed in a predetermined weight ratio.

Preferably, the predetermined weight ratio of titanium dioxide and tannin may be 0.01 to 20%.

Preferably, the flexible optical film of the present invention is resistant to high temperatures up to 200 °C.

Preferably, the flexible optical film of the present invention has a glass transition temperature of -40 °C.

Preferably, the flexible optical film of the present invention has a refractive index of 1.6 to 2.0.

In addition, the present invention further provides a flexible optical film, which may comprise silicone, titanium dioxide, and phosphor powder or phosphor powder. The silicone, titanium dioxide, and phosphor powder or phosphor powder are mixed in a predetermined weight ratio.

Preferably, the predetermined weight ratio of the silicone rubber, the titanium dioxide, the phosphor powder or the phosphor powder may be 85 to 99.7: 0.1 to 5: 0.2 to 10.

Preferably, the phosphor powder or phosphor powder may be yttrium aluminum garnet (YAG), nitride, silicate or sulfide.

As stated above, the flexible optical film of the present invention may have one or more of the following advantages:

(1) When it is bent, no creases will occur, and it will return to its original shape and position without affecting its optical properties due to damage of the optical film.

(2) The scattering particles (titanium dioxide) are applied to the silicone, and the difference in refractive index is used to scatter the light to cause an optical diffusion effect.

(3) Using titanium dioxide, the refractive index of the optical film is better than that of a general optical film.

(4) After adding phosphor powder or phosphor powder, the optical properties of the optical film can be better.

The advantages and features of the present invention, as well as the method of achieving the same, will be more readily understood by referring to the exemplary embodiments and the accompanying drawings. However, the invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, the embodiments are provided to provide a thorough and complete and complete disclosure of the scope of the invention, and the invention Defined. In the figures, the dimensions and relative dimensions of the components are shown in an exaggerated manner for clarity and clarity. Throughout the specification, the same component symbols refer to the same components. As used hereinafter, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Unless otherwise defined, all terms (including technical and scientific terms) used hereinafter have the same meaning as commonly understood by those skilled in the art to which the invention belongs. It will be further understood that terms such as those defined by commonly used dictionaries should be understood to have the meaning consistent with the relevant art and will not be overly idealized or excessive unless explicitly defined below. Formal meaning understanding.

The exemplary embodiments will be described in detail below with reference to the drawings. However, the embodiments may be embodied in different forms and should not be construed as limiting the invention. The disclosure of the present invention is intended to be complete and complete, and those skilled in the art will be able to understand the scope of the invention.

Please refer to FIG. 1 , which is a flow chart of the steps of manufacturing the flexible optical film of the present invention. Contains the following steps:

S11: mixing titanium dioxide and silicone rubber in a predetermined weight ratio;

S12: coating or printing the mixture on a substrate or pouring into a mold, and then baking at a predetermined temperature;

S13: The molded optical mixture is separated from the substrate or the mold to take out the flexible optical film of the present invention and cut according to the needs of the user.

Wherein, before the step S11, the surface of the titanium dioxide may be subjected to lipophilic treatment to improve the affinity of the titanium dioxide and the tannin to promote the formation of a mixture with better stability.

Then, after the step S11, the vacuum degassing reaction can be utilized to cause the mixture to be uniformly mixed, so that the titanium dioxide and the tannin can be more closely and uniformly mixed, and air or the like can be prevented from being mixed between the two.

Wherein, after the titanium dioxide and the tantalum gum are closely and uniformly mixed, according to the preferred aspect of the present invention, the mixture may be coated or printed on a substrate to perform a vacuum degassing process. Further, in accordance with another preferred aspect of the present invention, the mixture can be poured into a mold for a vacuum degassing process.

At the same time, when titanium dioxide is mixed with silicone rubber, a predetermined weight ratio of phosphor powder or phosphor powder may be added; wherein, the fluorescent powder or phosphor powder may be added to illuminate the flexible optical film of the invention to increase color rendering. Presentation of (CRI) and R9 (saturated red), which will be described in detail later.

The predetermined weight ratio of the titanium dioxide and the tannin may be 0.01 to 20%, preferably 0.1 to 10%, more preferably 0.1 to 2%. In the case of baking in a mold, the temperature may be about 50 to 150 ° C, preferably 80 to 120 ° C, and the time required is about 30 minutes to 4 hours. More recently, at this temperature, the gelatinization degree is better, the structure is firmer and the strength is better; relatively, if the reaction temperature is lower than 80 °C or even lower than 50 °C, the curing reaction is incomplete. The structure is weak and easily damaged by external force. If the reaction temperature is higher than 120 ° C or even higher than 150 ° C, the reaction of titanium dioxide and tannin mixed will be too fast, the uniformity of the structure is not good, and the flexible optical film 100 is The thickness will become uneven. Therefore, under the conditions of the present invention, the fabrication conditions of the flexible optical film 100 can be optimized, and the unpredictable advantages and effects are obtained compared to the optical film of the conventional process.

In addition, the additional fluorescent powder or phosphor powder of the flexible optical film of the present invention may be yttrium aluminum garnet (YAG), nitride, niobate or sulfide, and the added weight percentage may be 0.2-10%. Preferably, it is 0.2 to 5%, more preferably 0.2 to 2%.

In addition, the present invention can utilize different modules to structurally modify the surface of the optical film, so that the flexible optical film of the present invention has different optical characteristics, which will be described later in detail.

Please refer to FIG. 2, which is a schematic structural view of a flexible optical film of the present invention. As shown in the figure, the flexible optical film 100 of the present invention may comprise titanium dioxide 101 and silicone 102; wherein the titanium dioxide and the silicone are mixed at a predetermined weight ratio, and the predetermined ratio may be 0.01 to 20%, preferably 0.1 to 10%, more preferably 0.1 to 2%.

In the flexible optical film 100 of the present invention, since the silicone resin 102 is an elastic body, when the silicone resin 102 is used as a substrate, it does not affect its optical characteristics when it encounters a tortuosity, and the addition of the titanium oxide 101 increases its refractive index. The optical properties are better; the refractive index of silicone 102 is only 1.4~1.55, and the refractive index after adding titanium dioxide 101 can be 1.6~2.0. It is particularly helpful for its physical and optical properties for diffusing light.

In addition, according to another aspect of the present invention, the flexible optical film 100 of the present invention may additionally add a phosphor powder or a phosphor powder such that the weight ratio of the silicone rubber, the titanium dioxide, and the phosphor powder or the phosphor powder is 85-99.7:0.1. ~5: 0.2~10, preferably 93~99.7: 0.1~2: 0.2~5, more preferably 96~99.7: 0.1~2: 0.2~2. The phosphor powder or phosphor powder may be yttrium aluminum garnet (YAG), nitride, silicate or sulfide.

In addition, please refer to Figure 1 of the annex, which is a schematic view of a conventional PET optical film when it is bent. It can be clearly seen that the optical film made of the conventional PET not only has obvious dents after the zigzag, but also has a great influence on its physical and optical properties, and the high temperature resistance is only up to 150 °C. In contrast, referring to FIG. 2 and FIG. 3 of the attachment, the flexible optical film 100 of the present invention, after being tortuous, not only does not cause creases due to meandering, but optical and physical properties are not affected by the tortuosity. The high temperature resistance property can be up to 200 ° C, and the glass transition temperature (Tg) can be up to -40 ° C. That is, the flexible optical film 100 of the present invention can have good physical properties that can maintain elasticity even in a cold and cold environment. nature. Therefore, it is obvious that the flexible optical film 100 of the present invention is not only resistant to tortuosity, but also has better physical and optical characteristics than the conventional optical film, and can exist in a more severe environment.

Please refer to FIG. 3, FIG. 4 and the attached figure 4, and FIG. 3 is a schematic view showing the surface structure of the surface of the flexible optical film of the present invention which is modified by another different mold. Figure 4 is a SEM image of the surface structure of the surface of the flexible optical film of the present invention modified by a different mold. Fig. 4 is a comparison view of the surface of the flexible optical film of the present invention.

As shown in Fig. 3, the surface of the flexible optical film 100 of the present invention may have an uneven surface after being modified by another different mold (not shown). After the structure is processed, the light can be more anti-reflective, so that the flexible optical film 100 of the present invention can have good light diffusibility or light transmittance.

As shown in Fig. 4, a scanning electron microscope (SEM) was used to observe the flexible optical film 100 of the present invention in a different mold (not shown), and the uneven structure of the surface was apparent. It can be seen from FIGS. 3 and 4 that the anti-reflective optical film can have better light diffusibility and optical properties as a substrate, and thus has a better application mode for the backlight or illumination system of the panel.

As shown in Figure 4 of the annex, it can be clearly seen that the right half is the planar structure of the flexible optical film of the present invention. It can be clearly seen that when the surface is smooth, it has a reflection phenomenon, so the fluorescent lamp is performed. Reflection, while the left half is the surface treated with different molds, it can be clearly seen that the surface does not reflect the fluorescent lamp, so the left half obviously has anti-reflection effect, and the two can be applied to different The level.

Furthermore, in order to confirm that the flexible optical film of the present invention has good optical properties, the following data demonstrates and supports the properties possessed by the flexible optical film. It is to be noted that the description herein is merely illustrative and not restrictive, and the limitations of the scope of the invention should be described in detail in the claims.

Please refer to FIG. 5 , which is a structural diagram of the flexible optical film of the present invention applied in an illumination system of an organic light emitting diode (OLED). As shown, a conventional OLED backlight or illumination system can include a glass layer 103, an indium tin oxide layer 104, an organic layer 105, and a cathode 106; and the flexible optical film 100 of the present invention can be placed in the glass layer 103. Below. Wherein, the flexible optical film 100 of the present invention is used as a substrate for an OLED backlight or illumination system (when the weight ratio of titanium dioxide and tantalum is 0.1 to 2%), and the conventional OLED backlight or illumination system (titanium dioxide and tantalum weight) When the percentage is 0%), the light extraction benefit can be increased, as shown in Table 1 below.

Table 1

 

Please refer to Table 1, which is a data sheet when the weight ratio of titanium dioxide to tannin is 0~2%. It can be clearly seen that the thickness of the flexible optical film in this embodiment is 0.5-0.8 mm, which is flexible in the present invention. When the weight ratio of titanium dioxide and tantalum of the optical film 100 is 0.1 to 2%, the light extraction efficiency is significantly better than that of the conventional OLED backlight or illumination system (0%). And when the amount of titanium dioxide is increased, the haze becomes higher, and the light transmittance becomes lower, because when the scattering particles (titanium dioxide) are more, the traveling of the light is blocked, so that the haze is increased, and Light penetration is low.

In addition, the flexible optical film of the present invention may also add phosphor powder for OLED illumination to increase the color rendering (CRI) and R9 (saturated red), as shown in Table 2 below.

Table 2

Referring to Table 2, it can be clearly seen that when titanium dioxide is added to tannin, the difference in color difference (Delta) and correlated color temperature (CCT) is significantly smaller, and the values of color rendering (CRI) and R9 (saturated red) become higher. . After adding the phosphor powder, the effect is more obvious. The phosphor powder or phosphor powder used may be yttrium aluminum garnet (YAG), nitride phosphor powder 1 (A630) or nitride phosphor powder 2 (A650), and YAG emits fluorescence at a wavelength of 560 nm. Powder, nitride phosphor 1 (A630) is a phosphor with a light-emitting wavelength of 630 nm, and nitride phosphor 2 (A650) is a phosphor with a light-emitting wavelength of 650 nm.

Furthermore, the smaller the chromatic aberration difference value (Delta), the less the chromatic aberration is presented in the case of having a viewing angle. In addition, the light color emitted by the artificial light source and the light color radiated by the black body at a certain temperature, the light color closest to the black body is called the correlated color temperature (CCT); in general, the color temperature is 5000, and the color temperature is less than 5000. It is called warm color (reddish), while countries in high latitudes are more popular because of the cold climate; on the contrary, those with a color temperature higher than 5,000 are called cool colors (blue). On the other hand, when the flexible optical film of the present invention contains titanium dioxide and phosphor powder, the correlated color temperature tends to be reddish. The natural color representation of the warm color (red) is important for high-quality lighting in commercial areas such as homes and offices, while the flexible optical film of the present invention exhibits superior color rendering (CRI) and R9 (saturated red). effect.

The above is merely illustrative and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

100. . . Flexible optical film

101. . . Titanium dioxide

102. . . Silicone

103. . . Glass layer

104. . . Indium tin oxide layer

105. . . Organic layer

106. . . cathode

The above and other features and advantages of the present invention will be made apparent by those skilled in the <RTIgt;
Figure 1 is a flow chart showing the steps of manufacturing the flexible optical film of the present invention;
2 is a schematic structural view of a flexible optical film of the present invention;
Figure 3 is a schematic view showing the surface structure of the surface of the flexible optical film of the present invention modified by using another different mold;
4 is an SEM image of a surface structure modified by the surface of the flexible optical film of the present invention by using another different mold; and FIG. 5 is a view showing the flexible optical film of the present invention used in an organic light-emitting diode ( Schematic diagram of the structure in the backlight system of OLED).

100. . . Flexible optical film

101. . . Titanium dioxide

102. . . Silicone

Claims (17)

A method of manufacturing a flexible optical film comprising the following steps:
Mixing titanium dioxide and a gum in a predetermined weight ratio to form a mixture;
Coating or printing the mixture on a substrate or pouring into a mold, and then baking at a predetermined temperature; and separating the molded mixture from the substrate or the mold to obtain the flexible optical film,
Wherein, the predetermined weight ratio of the titanium dioxide and the silicone rubber is 0.01 to 20%. The method of claim 1, wherein before the titanium dioxide and the silicone are mixed in the predetermined weight ratio, the method further comprises first treating the surface of the titanium dioxide with a lipophilic treatment to increase the binding of the titanium dioxide and the tannin. The steps of the nature. The manufacturing method according to claim 1, wherein after the titanium oxide and the silicone are mixed in the predetermined weight ratio to form the mixture, the method further comprises the step of uniformly mixing the mixture by using a vacuum degassing reaction. The production method according to claim 3, wherein, after the mixture is uniformly mixed, the mixture is coated or printed on the substrate, and a vacuum degassing process is performed. The manufacturing method according to claim 3, wherein, after the mixture is uniformly mixed, when the mixture is poured into the mold, a step of a vacuum degassing process is performed. The manufacturing method of claim 1, wherein the mixture is poured into another mold of a different structure such that the flexible optical film has a different surface structure. The manufacturing method according to claim 1, wherein the predetermined temperature is 50 to 150 °C. The manufacturing method according to claim 1, wherein the time required for baking the mixture is from 30 minutes to 4 hours. According to the manufacturing method of the first aspect of the invention, when the titanium dioxide and the silicone are mixed in the predetermined weight ratio, a phosphor powder or a phosphor powder is added in a predetermined weight ratio. The manufacturing method according to claim 9, wherein the phosphor powder or phosphor powder is yttrium aluminum garnet, nitride, niobate or sulfide. The manufacturing method according to claim 9, wherein the predetermined weight percentage is 0.2 to 10%. A flexible optical film comprising: titanium dioxide and a silicone, the titanium dioxide and the silicone are mixed in a predetermined weight ratio; wherein the predetermined weight ratio is 0.01 to 20%. The flexible optical film of claim 12, wherein the flexible optical film is resistant to high temperatures up to 200 °C. The flexible optical film of claim 12, wherein the flexible optical film has a glass transition temperature of -40 °C. The flexible optical film of claim 12, wherein the optical film has a refractive index of 1.6 to 2.0. A flexible optical film comprising: a silicone, titanium dioxide, and a phosphor or a phosphor powder, the silicone, the titanium dioxide, and the phosphor or the phosphor are mixed in a predetermined weight ratio; wherein the predetermined weight The ratio is 85~99.7: 0.1~5: 0.2~10. The flexible optical film of claim 16, wherein the phosphor powder or phosphor powder is yttrium aluminum garnet, nitride, niobate or sulfide.