TWI575006B - Anti-reflective film and manufacturing method - Google Patents

Description

Antireflective film and manufacturing method thereof

A film having a selective anti-reflection effect on a light band, in particular, a film formed by mixing a nano-sized particle with a resin composition.

A general resin film may have different characteristics depending on the resin material and the additive component used, such as transparency, shading, scratch resistance, abrasion resistance, elasticity, conductivity, and the like. The existing high-tech resin film can have more than two characteristics at the same time, such as a light-proof, wear-resistant and conductive effect at the same time, but without a resin film having both transparent and light-shielding optical characteristics. Because transparency requires high light transmittance, shading requires high light reflectivity, and it is not easy to have a high transparent band and a high reflection band in a film.

However, the industrial use of this demand can be seen everywhere, such as glasses, glass patches, luminaire film and white LED packaging industry, etc., where a transparent band needs to reflect a specific band of light source at the same time, all of them are pursuing high transparency. Highly reflective films are targeted, such as lenses that are resistant to UV or blue light. However, in the prior art, a multilayer dielectric film or a metal film is plated on an optical component or a transparent substrate, thereby layering various transmission characteristics of the light wave, including transmission, reflection, absorption, scattering, polarization, and phase. Changes, etc., such a combination of special combinations designed to modulate the desired properties, is now the most common as a so-called antireflective film user.

The antireflective film of the present invention is a double-characterized film composed of a transparent resin and a plurality of nanospheres which are non-periodically arranged. By changing the thickness of the film and the particle size of the plurality of nanospheres, the wavelength range of the reflected light can be further changed, so that a single film formed of a highly transparent resin composition has a thickness of between 0.001 mm and 1.0 mm. It is capable of simultaneously having a high penetration band and reflecting a specific wavelength.

The method for preparing the antireflective film of the present invention comprises mixing a plurality of high-dispersion colloidal solution of a nanosphere with a monomer material of a transparent resin, and the solvent in the colloidal solution is evaporated to form a non-periodic state by curing. A plurality of nanosphere-enhanced films are arranged.

The antireflection film prepared by the technique of the invention can be adjusted by adjusting the particle size of a plurality of nanospheres in the range of 10 nm to 1000 nm, and the film thickness is between 0.001 mm and 1.0 mm, so as to enhance the penetration. The film is highly reflective of specific wavelengths. For example, a non-periodic structure formed by nano particles of a specific particle size can be highly reflective of ultraviolet light, which can make the ultraviolet light transmittance close to zero, and at the same time, the antireflection film has high wear in the visible light range. The penetration rate allows the finished product to have both a transparent appearance and a harmful light band.

Therefore, the present invention can be applied to any film product that needs to reflect a specific wavelength and requires high transparency, has the advantages of replacing the conventional multilayer film and reducing the film forming cost, and is beneficial to promoting the industrial development of the optical film industry.

1‧‧‧Transparent resin

2‧‧‧Nami Ball

3‧‧‧LED lamps

4‧‧‧Fluorescent film

5‧‧‧film

6‧‧‧shade

A‧‧‧Nami Ball

B‧‧Nee Ball

Fig. 1 is a structural view of a film of the present invention.

Fig. 2 is a structural view of the nanosphere of the present invention.

Figure 3 is a graph showing the transmittance of the film of different thicknesses of the present invention.

Figure 4 is a graph showing the transmittance of the film of different particle sizes of the present invention.

Figure 5 is a schematic view of an embodiment of the present invention.

Fig. 6 is a comparison diagram of the relative luminous intensity test of the antireflection film of the present invention.

The antireflective film of the invention is prepared by mixing a high-dispersion multi-nose colloidal solution with a monomer material of a transparent resin, evaporating the solvent in the colloidal solution, and then solidifying the resin by curing. An antireflective film having a plurality of nanospheres arranged in a non-periodical manner is formed.

In the foregoing manufacturing method, depending on the characteristics of the transparent resin to be used, different material formulations and curing procedures may be used, and the present invention may optionally use a photocurable resin, a thermosetting resin or a combination thereof.

The term "photocurable resin" means that the resin monomer and the photoinitiator are irradiated with ultraviolet light (optional wavelength range of 200 nm to 400 nm), and the photoinitiator absorbs ultraviolet radiation energy to generate free radical electron jump. Producing an active center in a very short period of time, causing the active center to interact with the unsaturated groups of the resin monomer, initiating a resin monomer or a diluent molecule (depending on the desired film properties, such as the desired viscosity, it may need to be different The double bond between the reaction additive amount is broken, and continues to cause continuous polymerization of the radical, and cross-linking to form a film.

In the present invention, the material of the photocurable resin that can be used comprises an acrylate monomer, an acrylate oligopolymer monomer, or a combination thereof. In the present embodiment, an acrylate monomer is used. Since the acrylate has excellent weather resistance, transparency, color retention and mechanical strength, the acrylate monomer may be selected from Tripropylene glycol diacrylate. TPGDA), Neopropylene glycol diacrylate (NPGDA), Propoxylated neopropylene glycol diacrylate (PO-NPGDA), Trimethyloipropane triacrylate (Trimethyloipropane) Triacrylate, TMPTA), Ethoxylated trimethyloipropane triacrylate (EO-TMPTA), Propoxylated trimethyloipropane triacrylate (PO-TMPTA), C Propoxylated glyceryl triacrylate (GPTA), Di-trimethyloipropane tetraacrylate (di-TMPTA), Ethoxylated pentaerythritol tetraacrylate (Ethoxylated pentaerythritol tetraacrylate) , EO-PETA), Dipentaerythritol hexaacrylate (DPHA) or a combination thereof.

However, acrylate oligopolymer monomers can also be used as photocurable resin materials, such as: Epoxy acrylate (EA), Urethane acrylate (PUA), Polyester acrylate (PEA). ), Unsaturated polyester acrylate (UPE), Amine acrylate, Silicon acrylate, or a combination thereof.

Further, if a thermosetting resin is used as the transparent resin material, a thermosetting silicone resin which is cured by oven heating or addition of a curing agent may be used. The thermosetting resin material selected in the embodiment includes Methyl silicon, Phenyl silicon or a combination thereof.

The antireflective film of the present invention, wherein the plurality of nanospheres are made of cerium oxide (Silica, SiO ₂ ), polystyrene (PS), polydimethyl siloxane (Polydimethyl siloxane) or a combination thereof. The formed nanosphere particles having a particle size of 10 nm to 1000 nm are selected from cerium oxide in this embodiment.

Further, in the present embodiment, before the resin monomer is cured into a film, the added and mixed cerium oxide nanosphere particles can be obtained in several ways, for example, (1) precipitation method: using water glass (Na ₂ O‧nSiO) ₂ ) forming a reaction with a mineral acid (such as sulfuric acid) in a neutral environment; or (2) a sol-gel method: the sol-gel method uses a decane oxide and an alcohol (for example, methanol or ethanol) as a solvent. Ammonia water is used as a catalyst and prepared by ultrasonic vibration. Of course, it can also be produced by other wet chemical methods, for example, hydrothermal method, spray lysis method, electrochemical process, etc., and can be selected according to the application range. The nanospheres in this embodiment are produced by a sol-gel method.

The mixing method of the resin and the nanosphere colloid can be uniformly mixed by using a disperser, a homogenizer, an ultrasonic disperser, a bead mill, a ball mill or a kneading machine.

Regarding the curing effect, if a photocurable resin is selected, a photoinitiator which promotes curing of the resin is added, and the photoinitiator may be selected from a acetophenone series photoinitiator, a hydroxyketone series photoinitiator, or a diphenyl group. Ketone series photoinitiator. Acetophenone series photoinitiator, for example, 2,2-diethoxyacetophenone (DEAP); hydroxyketone (α-Hydroxy ketone) series photoinitiator, such as hydroxymethyl 2-Hydroxy-2-methylphenylpropanone (HMPP), 1-Hydroxy-cyclohexyl-pheny-ketone (HCPK) or a combination thereof; Benzophenone series light start The agent is, for example, trimethyl benzophenone (TMP), methyl benzophenone (MBP) or a combination thereof. In this embodiment, a hydroxyketone series is used as a photoinitiator.

Adding the resin after the photoinitiator, the nanosphere colloid, and then removing the solvent (such as After the methanol, ethanol, acetone or toluene used in the nanosphere, the coating method such as coating, knife coating, roll coating, spray coating, gravure coating, curtain coating, etc. may be applied. The surface of the substrate, or a stamping method such as mold imprinting, presses a specific shape or structure.

Then, using a UV LED lamp, a high-pressure mercury lamp, an electrodeless lamp or a xenon lamp, etc., for 2 seconds to 20 minutes, wherein the illuminance is 5 mW/cm ² to 200 mW/cm ² , and the amount of ultraviolet light is between 4 mJ/cm ² and 2,000 mJ. Within the range of /cm ² , an antireflective film can be obtained accordingly.

If a thermosetting resin is used, no photoinitiator is added and no photocuring is required. Instead, the coated or molded glue is heated in an oven at 100 ° C to 160 ° C for 1 to 300 minutes to form an antireflective film (additional curing procedure can be added as needed, for example: 150 ° C oven heating 4 Hour); or add a hardener to cure at room temperature.

Regarding the structure of the antireflection film of the present invention, please refer to FIG. 1 and FIG. 2, and FIG. 1 is a structural view of the film of the present invention, and the electron micrograph shows the nanosphere of the whole transparent resin 1 film. 2 is a non-periodic arrangement, which is a disordered structure similar to quasimorphous arrays. 2 is a structural diagram of the nanosphere of the present invention, which further shows that the particle size of the nanosphere 2 is not uniform as shown by the nanosphere A and the nanosphere B in the figure, and about 10 nm to 20 nm as a whole. The range of differences can form a disordered structure that is non-periodically arranged.

The antireflective film was further subjected to light transmittance spectroscopy. First, please refer to Fig. 3, which is a spectrum diagram of the film penetration rate of different thicknesses of the present invention. The film of different thicknesses formed by the same size of 100 nm particle size nanospheres is used in the test, wherein Film 1 (having a thickness between 0.3 mm and 0.5 mm) is thicker than film 2 (having a thickness between 0.1 mm and 0.2 mm), while films of different thickness have different transmittances for different wavelengths in the visible range.

Next, the film having the same thickness but different particle diameters of the nanospheres is subjected to light transmittance measurement. Test, as shown in Fig. 4, Fig. 4 is a graph showing the transmittance of the film of different particle sizes of the present invention. Under the same film thickness (between 0.1 mm and 0.2 mm), the particle diameters are respectively When 100 nm (particle size 1), 150 nm (particle size 2), 160 nm (particle size 3), and 180 nm (particle size 4), films of different particle sizes can be used to scatter light of different wavelengths so that light in the same wavelength range can be worn. The penetration rate is different.

Therefore, according to the constructive interference, and the theory of Rayleigh scattering, that is, the linear superposition of light waves, and the theoretical basis of the selective scattering wavelength of particles, it is possible to formulate different film thicknesses and different nanometers. The combination of the particle size allows the film to reflect the specific wavelength required while having a high transmittance. As shown in Fig. 4, the antireflective film of the present invention can make the light transmittance below 400 nm close to zero, and the wavelength range of visible light still has a high transmittance, which is very suitable for application to both ultraviolet resistance and Highly transparent products.

Further, the antireflection film of the present invention can be applied to the fluorescent film of the high power LED lamp module. Please refer to FIG. 5, which is a schematic view of an embodiment of the present invention. In general, a cool color temperature (5000K) white LED lamp 3 whose white light is a combination of a blue LED and a two-color phosphor 4 combines white light. The antireflective film 5 of the present invention is attached to the surface of the two-color fluorescent sheet 4. In the present embodiment, the film thickness of the film 5 is between 0.1 mm and 0.2 mm, and the particle diameter of the nanosphere is 100 nm. The results are shown in Fig. 6. Fig. 6 is a comparative diagram of the relative luminescence intensity test of the antireflection film of the present invention, and the control group to which the film 5 is not attached is attached to the film (i.e., the experimental group). The relative luminous intensity of the blue light band (wavelength of 400nm to 500nm) is reduced by up to about 15% (absorbance/Absorbance unit), while the red light band (wavelength of 600nm to 800nm) is increased by up to 10% (absorbance/Absorbance unit). As a result, the 5000K cold color white LED lamp can be reduced to a color temperature of 2700 to 3000K, which becomes a warm LED lamp, which produces a function of adjusting the color temperature.

In addition, the surface of the phosphor sheet plus the antireflective film will also form a white film, just like Fluorescent shades help LED manufacturers promote their lamps.

The antireflective film of the present invention may be further prepared by adding a suitable additive, such as a thermal conductive additive, a flame retardant, a pigment, an oxidation inhibitor, a UV stabilizer, a dispersing agent, or the like, in addition to the above-mentioned components. A foaming agent, a tackifier, a plasticizer, a decane coupling agent, etc., and more than one of various known additives to add other special properties.

In summary, the antireflection film disclosed in the present invention and the manufacturing method thereof can produce a high transparent adhesive film with different reflection bands according to actual needs, which meets the needs of various industries and replaces the existing multilayer film and colored cellophane. Even changing the color temperature of the lamp, the application range is wide, and it is expected that the optical film industry will take a big step forward.

1‧‧‧Transparent resin

2‧‧‧Nami Ball

Claims (6)

An antireflective film comprising: a transparent resin having a thickness of between 0.001 mm and 1.0 mm; and a plurality of nanospheres arranged non-periodically in the transparent resin, and the particles of the nanosphere The diameter is from 10 nm to 1000 nm, wherein the material of the transparent resin is a thermosetting resin, and the material of the thermosetting resin comprises methyl hydrazine, phenyl hydrazine or a combination thereof. The antireflection film according to claim 1, wherein the nanosphere has a particle diameter of further 100 nm to 300 nm, and the transparent resin has a thickness of between 0.001 mm and 0.5 mm. The antireflection film of claim 1, wherein the nanosphere has a particle diameter of further 100 nm, and the transparent resin has a thickness of between 0.001 mm and 0.1 mm. The antireflection film of claim 1, 2 or 3, wherein the material of the nanosphere is selected from the group consisting of ceria, polystyrene, polydimethyloxane or a combination thereof. A method for producing an antireflective film for producing the antireflective film according to claim 1, 2 or 3, which is prepared by mixing a monomer material of the transparent resin by a sol-gel method and ultrasonic vibration Highly dispersible colloidal solution of the plurality of nanospheres, and one of the curing of the oven at 100 ° C to 160 ° C for 1 to 300 minutes to form the antireflective film having the plurality of nanospheres having a non-periodically arranged . The method for producing an antireflective film according to claim 5, wherein the monomer material of the transparent resin is further a monomer material of a thermosetting resin series, and the curing agent is added at room temperature to form the antireflection. Film.