Patent Application
20070285788
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:
Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.
Referring to
The transparent anti-glare film 11 incorporates a plurality of water-soluble scattering particles 12 distributed therein. Specifically, the water-soluble scattering particles 12 are distributed within the transparent anti-glare film 11 and on a surface of the transparent anti-glare film 11.
The water-soluble scattering particles 12 are preferably colloidal particles made of gelatin, hydrogel, polyvinyl alcohol, or the like.
The transparent anti-glare film 11 is made of an ultraviolet curable resin, a thermoplastic resin, a thermosetting resin, or the like. An example of the ultraviolet curable resin is an acrylate resin. Examples of the thermoplastic resin include an acrylic resin, an acetal resin, or the like. Examples of the thermosetting resin include an epoxy resin, polyurethane, or the like. Preferably, the material for the transparent anti-glare film 11 has an optical transmission of at least 90% and a pencil hardness of at least 3 H. The more the pencil hardness, the better the scratch resistance of the transparent anti-glare film 11 will be.
The transparent substrate 2 is made of a transparent material, such as plastic, glass, or the like. Examples of the plastic material include polyethylene terephthalate, polyethylene-2,6-naphthalate, cellulose triacetate, or the like. Optionally, other films, such as a low reflection film, an antistatic film, or the like, can be applied on the transparent anti-glare film 11 to provide a multi-functional optical film for the anti-glare device 1.
Referring to
A) mixing:
A transparent resin solution is mixed with an aqueous solution of water-soluble colloid by stirring with a high speed stirrer to form an emulsion containing a plurality of water-soluble colloidal particles distributed in the emulsion. The aqueous solution of water-soluble colloid may be an aqueous gelatin solution, an aqueous hydrogel solution, or an aqueous polyvinyl alcohol solution. Preferably, the stirring is conducted at a stirring rate ranging from 6000 to 12000 revolutions per minute (rpm) for a period ranging from 30 to 90 minutes.
B) applying:
The emulsion is applied on the transparent substrate 2 to form a preliminary film on the substrate
C) drying:
The preliminary film is baked or is allowed to stand for a period so as to evaporate and remove the solvent in the transparent resin solution and the water in the aqueous solution of water-soluble colloid from the preliminary film.
D) curing:
The preliminary film is cured, for example, by irradiating with an ultraviolet light or by heating to form a transparent anti-glare film 11 on the transparent substrate 2. The transparent anti-glare film 11 includes a plurality of scattering particles 12 formed of the colloidal particles distributed within the transparent anti-glare film 11 and on a surface of the transparent anti-glare film 11.
Referring to
The method for making the anti-glare device 1′ is similar to that for making the anti-glare device 1 except that it further includes a step of removing the scattering particles 12 present on the surface of the transparent anti-glare film 11 after the curing step so as to form a plurality of indentations 13 on the surface of the transparent anti-glare film 11. The scattering particles 12 present on the surface of the transparent anti-glare film 11 can be removed by treating the surface of the transparent anti-glare film 11 with water, for example, by spraying the surface of the transparent anti-glare film 11 with water or by dipping the transparent anti-glare film 11 in water. Depending on the scattering particles 12 to be removed, water can be optionally preheated so as to enhance the dissolution of the scattering particles 12 present on the surface of the transparent anti-glare film 11. For example, if the scattering particles 12 are made of gelatin, water can be preheated to a temperature ranging from 50 to 60° C.
The following examples are provided to illustrate the preferred embodiments of the invention, and should not be construed as limiting the scope of the invention.
25 parts by weight of gelatin was dissolved in 125 parts by weight of water at 50-60° C. to form a gelatin solution. The gelatin solution was mixed with 200 parts by weight of an acrylate resin solution (5537C-50, manufactured by Eternal Chemical Co. Ltd., Taiwan, and containing 50% of acrylate resin and 50% of toluene) by stirring homogeneously at a stirring rate of 8000 rpm for 60 minutes to form an emulsion. The emulsion was applied on a transparent cellulose triacetate substrate of 80 μm, was dried at 80° C. for 2 minutes to evaporate water and toluene out of the emulsion, and was cured by irradiating with ultraviolet light at 230 mj/cm2 to form a 5 μm anti-glare film 11 on the substrate 2, as best shown in
The anti-glare film 11 formed in Example 1 is dipped in water at 50-60° C. for about 2 minutes to remove at least some of the scattering particles 12 on a surface of the transparent anti-glare film 11 so as to form a plurality of indentations 13 on the surface of the transparent anti-glare film 11, as best shown in
The procedure of Example 2 was repeated except that the gelatin solution was formed by dissolving 5 parts by weight of gelatin in 25 parts by weight of water at 50-60° C., and that the transparent cellulose triacetate substrate was replaced with a transparent polyethylene terephthalate substrate.
This example is substantially identical to Example 3 except that the gelatin solution was formed by dissolving 15 parts by weight of gelatin in 25 parts by weight of water at 50-60° C.
This example is substantially identical to Example 4 except that 2 parts by weight of silica particles (OK607, manufactured by Degussa Co., Ltd., a particle size of 2 μm) was added to the acrylate resin solution. The acrylate resin solution containing the silica particles was then stirred with the gelatin solution at a stirring rate of 3000 rpm for a period of 120 minutes to form an emulsion. The emulsion applied on the polyethylene terephthalate substrate was cured by irradiating with ultraviolet light at 250 mj/cm2 to form an anti-glare film on the substrate.
8 parts by weight of silica particles (OK607, manufactured by Degussa Co., Ltd., a particle size of 2 μm) were stirred with 200 parts by weight of an acrylate resin solution (PC-538, manufactured by Pufong Enterprise Co., Ltd., Taiwan, and containing 50% of acrylate resin and 50% of isopropanol) at a stirring rate of 3000 rpm for 120 minutes to form an emulsion. The emulsion was applied on a transparent cellulose triacetate substrate of 80 μm, was dried at 80° C. for 2 minutes, and was cured by irradiating with ultraviolet light at 250 mj/cm2 to form a 5 μm anti-glare film on the substrate, as best shown in
The procedure of Comparative Example 1 is repeated except that 5 parts by weight of silica particles were used and that the cellulose triacetate substrate was replaced with a transparent polyethylene terephthlate substrate.
The haze value and the clarity of specimens of Examples 1-5 and Comparative Examples 1-2 were measured according to Standard JIS K 7105. The results are shown in Table 1.
The haze value was measured using a turbidity meter, Model No. NDH2000 manufactured by Nippon Denshoku Co., Ltd, Japan. Clarity was measured using a clarity meter, Model No. ICM-1T manufactured by Suga Test Instruments CO. Ltd. It should be noted that the clarity expressed in Table 1 is the sum of the clarity values measured at five different aperture widths (i.e., 0.125 mm, 0.25 mm, 0.5 mm, 1.0 mm, and 2.0 mm).
On comparing Examples 1 and 2 with Comparative Example 1, when the haze value is about 20%, the clarity of Examples 1 and 2 is significantly higher than that of Comparative Example 1. On comparing Examples 4 and 5 with Comparative Example 2, when the haze value is about 14%, the clarity of Examples 4 and 5 is significantly higher than that of Comparative Example 2. However, since silica particles were incorporated in Example 5, the clarity of Example 5 is lower than that of Example 4. It is thus demonstrated that the clarity of an anti-glare film can be improved by substituting the water-soluble scattering particles for the silica particles and by forming the indentations on the surface of the anti-glare film. Furthermore, in view of the results of Examples 1-4, when the haze value decreases to a lower level as shown in Example 3 and 4, the clarity of the anti-glare film is excellent due to the water-soluble scattering particles and/or the indentations.
While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 095118765 | May 2006 | TW | national |
