JP3488955B2 - Luminescent diffuse reflection film - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffusive reflection film for a liquid crystal display, and more specifically, it is a drawback of a liquid crystal display in which a phosphorescent resin layer is formed on the reflection surface of a conventional diffusion reflection film for a liquid crystal display. The present invention relates to a diffuse reflection film for a liquid crystal display that enables confirmation of a liquid crystal display even in a dark place without a backlight.

[0002]

2. Description of the Related Art Polyethylene terephthalate film in which a matting agent or a white pigment is kneaded, a film in which aluminum or silver is vapor-deposited on the matte surface, a matting agent or a white pigment are used as a diffuse reflection film for a liquid crystal display currently in use. A polyethylene terephthalate film coated with a pearl pigment and coated, a film having aluminum or silver vapor-deposited on its coated surface, an aluminum foil, an aluminum plate, a stainless plate, etc., all of which have no self-luminous property are used.

[0003]

Liquid crystal display devices include a reflective liquid crystal display device that uses external light as a light source and a transmissive liquid crystal display device that uses a backlight (cold cathode fluorescent lamp). The liquid crystal display device has a drawback that the display screen cannot be seen unless there is external light. On the other hand, the transmissive liquid crystal display device uses a backlight (cold cathode fluorescent lamp), which consumes a large amount of power and is accompanied by an auxiliary member. There was a drawback that it became heavy and heavy.

Therefore, an object of the present invention is that the display screen cannot be seen without external light, which is a problem in the above-mentioned liquid crystal display device, and that a backlight (cold cathode fluorescent lamp) is used, so that power consumption is large. It is an object of the present invention to solve the above-mentioned problems so as to provide an excellent light-accumulating diffuse reflection film that solves all the drawbacks of increasing the number of additional members and making them heavy.

[0005]

The luminous diffusive reflection film of the present invention has a structure in which a luminous resin layer 2 containing a luminous pigment is formed on the reflecting surface of a diffusive reflection film 1 for liquid crystal display, so that external light Even in the dark, the phosphorescent resin layer 2 serves as a light source to confirm the display screen, and the backlight (cold-cathode fluorescent lamp) is no longer needed, resulting in light weight without power consumption.

[0006]

The reason why the diffuse reflection film 1 for liquid crystal display is used is to function as a conventional diffuse reflection film in a bright place, and the reason why the light storing resin layer 2 is provided on the reflection surface is that light is reflected on the reflection surface. This is because there is an advantage that light energy can be stored in a short time because it is reflected.

The structure of the luminous diffuse reflection film of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the constitution of the light-accumulating diffuse reflection film of the present invention, and shows the constitution in which a light-accumulation resin layer 2 in which a light-accumulation pigment is dispersed is formed on the reflection surface of a diffusion reflection film 1 for liquid crystal display.

The diffuse reflection film 1 for a liquid crystal display of the present invention is a diffuse reflection film used in a reflection type liquid crystal display device, a semi-transmission semi-reflection type liquid crystal display device, and a transmission type liquid crystal display device. Is a polyethylene terephthalate film in which a matting agent or a white pigment is kneaded, a film in which aluminum or silver is vapor-deposited on the matte surface, a polyethylene terephthalate film in which a matting agent, a white pigment or a pearl pigment is applied and coated, and aluminum or silver on the coated surface. Film, aluminum foil, aluminum plate, stainless plate, etc. Among them, as the diffuse reflection film 1 for liquid crystal display, which is particularly effective, a diffuse reflection film having a high diffuse reflectance and a high whiteness is preferable. The reason is that it functions as a conventional diffuse reflection film in a bright place.

The light-storing resin layer 2 used in the light-storing diffuse reflection film of the present invention is a coating material made of a thermoplastic resin, a thermosetting resin, an electron beam curable resin, an ultraviolet curable resin or the like, for example, an amino resin. Resin, amino alkyd resin, acrylic resin, styrene resin, acrylic-styrene copolymer, polyester resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, urethane resin Resin, urea resin, melamine resin, urea-melamine resin, epoxy resin, fluorine resin, polycarbonate, nitrocellulose, cellulose acetate, alkyd resin, rosin-modified maleic acid resin, polyamide resin, etc. Alternatively, a paint in which a phosphorescent pigment is dispersed in a resin composed of a mixture is used. .

The phosphorescent pigment will now be described. The phosphorescent pigment is also referred to as a phosphorescent phosphor or a luminescent pigment, which can be excited by sunlight or a short wavelength component of a fluorescent lamp and has a very long phosphorescence. In brief, it is a pigment that has the property of storing light energy and emitting light like a firefly in a dark place and generally having an afterglow (self-luminous property).

As the phosphorescent pigment, zinc sulfide, zinc silicate,
There are zinc cadmium sulfide, calcium sulfide, strontium sulfide, calcium tungstate, and the like. Among them, zinc sulfide, zinc cadmium sulfide, and strontium sulfide, which have a long afterglow time, high brightness, and excellent durability, are preferable. As the performance of the phosphorescent pigment, a white or uncolored animal light pigment having a long afterglow time, a high brightness and excellent durability because it is used in a liquid crystal display device, and a luminescent color of white or uncolored light is desirable.

The phosphorescent resin layer 2 has the phosphorescent resin coating (a phosphorescent pigment mixed and dispersed in a synthetic resin coating) on the reflective surface of the liquid crystal display diffuse reflection film 1 by a gravure coating method, a reverse roll coating method,
It is formed by applying by a roll coating method, silk printing, etc. and drying (curing in the case of a curable resin). The thickness of the phosphorescent resin layer 2 is not particularly limited, but is usually 1 to 70 μm.
It is appropriately selected from the range of degrees. If the thickness is less than 1 μm, the surface of the diffuse reflection film 1 for liquid crystal display cannot be uniformly coated, and the effect of imparting afterglow (self-luminous property) cannot be sufficiently exerted, and the phosphorescent resin layer 2
Has no effect. On the other hand, when it exceeds 70 μm, not only the effect of using the diffuse reflection film 1 for liquid crystal displays cannot be sufficiently exhibited, but also the drying speed of the phosphorescent resin layer 2 becomes slow, which is inefficient and economically unfavorable. There is also a possibility that harmful effects such as the residue will occur.

The light-storing diffuse reflection film 1 thus obtained has a structure in which a light-storing resin layer 2 in which a light-storing pigment is dispersed is formed on the reflecting surface of the diffuse-reflection film 1 for a liquid crystal display. It is an excellent solution to all of the problems that the display screen cannot be seen unless there is external light, which is a problem with the device, and that the backlight (cold-cathode fluorescent lamp) consumes a large amount of power and increases the number of auxiliary members and makes it heavy. It was a thing.

The present invention is described in detail below with reference to examples, but the invention is not limited thereto.

[0015]

【Example】

Example 1 50 parts of acrylic resin (parts by weight, the same applies hereinafter), 40 parts of phosphorescent pigment (manufactured by Nemoto Special Chemical Co., Ltd.), and 20 parts of methyl ethyl ketone on the reflecting surface of an aluminum foil having a thickness of 100 μm.
Parts, 20 parts of toluene, a coating liquid is applied and dried,
A phosphorescent resin layer having a thickness of 10 μm (thickness after drying, the same applies hereinafter) was formed to obtain the phosphorescent diffuse reflection film of the present invention.

Example 2 Aluminum was vacuum-deposited to a thickness of 60 nm on one surface of a polyester film having a thickness of 50 μm and containing a matting agent, and a phosphorescent resin layer was formed on the aluminum vapor-deposited surface in the same manner as in Example 1. Thus, the phosphorescent diffuse reflection film of the present invention was obtained.

EXAMPLE 3 Silver was vacuum-deposited on one side of a polyester film having a thickness of 50 μm and containing a matting agent to a thickness of 150 nm, and a phosphorescent resin layer was formed on the silver-deposited surface in the same manner as in Example 1. ,
The phosphorescent diffuse reflection film of the present invention was obtained.

COMPARATIVE EXAMPLE 1 Silver was vacuum-deposited on one side of a polyester film having a thickness of 50 μm and containing a matting agent to a thickness of 150 nm, and 50 parts of acrylic resin, 20 parts of methyl ethyl ketone and 20 parts of toluene were deposited on the silver-deposited surface. Part of the coating solution was applied and dried to provide a corrosion-preventing layer having a thickness of 10 μm to obtain a diffuse reflection film.

Table 1 shows the results obtained by examining the luminous intensity (brightness) in the dark, the confirmation of the liquid crystal display screen in the dark, and the diffuse reflectance of the films of Examples and Comparative Examples thus obtained.

<Evaluation method of luminous intensity (brightness) in a dark place>
Brightness is visually determined <Method of confirming liquid crystal display screen in dark place> Is it possible to check the liquid crystal display screen in a dark place by changing the diffuse reflection film of the reflection type liquid crystal display device to the phosphorescent diffuse reflection film of the present invention? Judgment <Evaluation method of diffuse reflectance> The diffuse reflectance was measured using a spectrophotometer (UV-3100PC) manufactured by Shimadzu Corporation, and the diffuse reflectance at a wavelength of 550 nm was read.

[0021]

[Table 1]

From Table 1, the liquid crystal display screen of the example can be confirmed in a dark place and the liquid crystal display screen can be clearly confirmed even in a light place in comparison with the comparative example because the diffuse reflectance is high. It can be seen that it is.

[0023]

The luminous diffuse reflection film of the present invention has a constitution in which the luminous resin layer 2 in which the luminous pigment is dispersed is formed on the reflecting surface of the diffuse reflection film 1 for liquid crystal display. It is an excellent solution to all of the problems that the display screen cannot be seen unless there is external light, which is a problem with the device, and that the backlight (cold-cathode fluorescent lamp) consumes a large amount of power and increases the number of auxiliary members and makes it heavy. It is a thing.

[Brief description of drawings]

FIG. 1 is a sectional view showing a light-accumulating diffuse reflection film of the present invention.

[Explanation of symbols]

1 Diffuse reflection film for liquid crystal display 2 phosphorescent resin layer

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 G02B 5/00-5/136 G02F 1/1335-1/13363 G09F 9 / 30-9/46

Claims (3)

(57) [Claims] 1. A diffuse reflection film 1 for a liquid crystal display.
A phosphorescent resin layer 2 containing a phosphorescent pigment is formed on the reflective surface of the phosphorescent diffuse reflection film. 2. The phosphorescent diffuse reflection film according to claim 1, wherein the diffuse reflection film for a liquid crystal display is any one of a reflective liquid crystal display device, a semi-transmissive semi-reflective liquid crystal display device, and a transmissive liquid crystal display device. It is a diffuse reflection film used in, and is a phosphorescent diffuse reflection film. 3. The phosphorescent anti-light according to claim 1 or 2.
In the diffusion film, The phosphorescent resin layer 2 is Thermoplastic resin, thermosetting resin, electron beam curing resin, ultraviolet
Linear curable resin, resin made of any one or more of them
To Zinc sulfide, zinc silicate, zinc cadmium sulfide, calcium sulfide
Um, strontium sulfide, calcium tungstate
Or a plurality of pigments are dispersed.
The luminous storage diffuse reflection filter characterized by
Mu.