JPH0687993U - Silicone rubber color filter - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Useful for the purpose of enhancing the purity of the emission color in color display and improving the visibility under direct sunlight in a screen display device using a self-luminous display element. Provided is a silicone rubber color filter. [Structure] A transparent portion (2, 1, 3) composed of red, green, and blue is provided, and the transparent portion (2, 1, 3) composed of red, green, and blue is darkly colored or opaque. A color filter 7 made of silicone rubber, which is isolated by the light-shielding portion 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a silicone rubber color filter useful for a screen display device, particularly a screen display device for displaying information in color using self-luminous display elements having red, green, and blue emission colors. .

[0002]

[Prior art]

 In recent years, especially since the latter half of the 1980s, large-screen display devices of various principles have been rapidly put into practical use. For example, a large-screen display device using an electron beam fluorescent tube or a CRT as a display element can be counted as one of them, and this element has one set of stripe-shaped self-luminous portions composed of three primary colors (red, green, blue). Or, there are a plurality of pairs and have a flat light emitting surface. JP-A-59-210480 discloses a method for obtaining a color filter used for such a large-sized element by a spray method using a silicone rubber-based paint because silicone rubber has excellent heat resistance and weather resistance. It is being touched. However, the conventional color filters still have technical problems such as interference between primary colors, blurring of boundaries, accuracy, and pitch of repeating units.

[0003]

[Problems to be solved by the device]

 Under these circumstances, the present invention has been made in order to provide a silicone rubber color filter that solves the above-mentioned problems associated with interference, blurring, precision, and pitch.

[0004]

[Means for Solving the Problems]

 The silicone rubber color filter of the present invention solves the above-mentioned problems. It has a light-transmitting portion made of red, green, and blue, and a light-transmitting portion made of red, green, and blue. The gist of the invention is a color filter made of silicone rubber, which is isolated by a dark colored or opaque light shielding portion. The present invention will be described in detail below.

To manufacture the silicone rubber color filter of the present invention, first, the selected colorant is sufficiently dispersed in the uncured silicone rubber raw material in advance. The colorant is preferably one having excellent light resistance and heat resistance, but from this viewpoint, a pigment is preferable, and it is preferable to sufficiently disperse the pigment before use. In that case, the pigment itself can be dispersed directly or in the form of an inked colorant. For the light-transmitting part, it is ideal to match the main emission wavelength of the self-luminous body with the wavelength of the peak of the spectral transmittance of the color filter in which the colorant is dispersed, and to combine the above light resistance and heat resistance. You have to be careful about the agreement. When importance is attached to the spectral transmittance, an ultraviolet reflecting agent can be used to prevent ultraviolet deterioration. Next, materials for the dark colored or opaque light-shielding portion and the light-transmitting portion will be sequentially described in detail.

As the colorant used for the dark colored or opaque light-shielding portion, known black pigments such as iron oxide black, carbon black, graphite, and titanium black can be used, and one of them can be used. Alternatively, two or more kinds may be appropriately dispersed in a silicone rubber raw material by a known method, and the compounding amount may be adjusted to reach a desired spectral reflectance level. The desirable range of this compounding amount is 0 to 25%. Among the above black pigments, carbon black having an average primary particle diameter of about 0.1 to 0.5 μm is preferable because of its excellent hiding power. This one absorbs light in the visible light portion almost uniformly. Therefore, the transmitted light is also reduced.

On the other hand, the silicone rubber as a matrix in which the above-mentioned colorant is to be dispersed may be a millable type or a liquid type, and may be non-foamable or foamable. Considering the above, it is desirable that it is non-foaming. Further, the vulcanization type as another classification may be either peroxide vulcanization or addition vulcanization, but addition vulcanization is desirable because there are very few decomposition products.

In order to disperse the above-mentioned colorant in the uncured silicone rubber, a known kneader, three rolls or the like may be used for treatment in a conventional manner. If a vulcanizing agent, a cross-linking agent, and a catalyst are added to and dispersed evenly according to the vulcanization type, a mixture that will be a molding material for dark colored or opaque parts can be obtained. Other necessary components may be added in each of the above steps.

Next, the translucent parts of red, green and blue which are the three primary colors of the color filter will be described. For this light-transmitting portion, it is of course desirable that the main emission wavelength of the self-luminous body and the wavelength of the peak of the spectral transmittance of the color filter in which the colorant is dispersed are matched. In addition, this light-transmitting portion must also have a function of cutting unnecessary light such as a bright line spectrum that appears other than the main light emission wavelength of the self-luminous portion. However, since the characteristics of the pigment itself or the colorant formed into an ink directly determine the spectral characteristics of the light transmitting portion, the degree of freedom is not so large. However, if the colorant is selected, its dispersion state is uniform in the silicone rubber of the matrix, and the thickness of the filter that serves as the optical path is determined, the final spectral characteristics of the colorant are determined at the same time. The instability factor becomes extremely small.

Regarding the colorant used in the light transmitting portion, it is necessary to select a spectral transmittance curve within the visible wavelength range and a chromaticity coordinate. The self-luminous body to be used, for example, an emission main wavelength of an electron beam fluorescent tube is λ, a mixing ratio of a pigment or an inked colorant is c ', a thickness of a filter as an optical path is d', and a wavelength λ at that time Suppose that T '(λ) is the spectral transmittance at T, then the following conditions (spectral transmittance of silicone rubber, amount of filler in silicone rubber, filter (Those related to the thickness of), the change in the extinction coefficient ε is considered to be extremely small, so

[0011]

[Equation 1] May be approximated. Here, T ″ (λ) is the spectral transmittance at the wavelength λ when the thickness of the filter serving as the optical path is d ″.

When the blending ratio of the colorant changes, the spectral characteristics also change at the same time. In general, the color purity increases as the proportion of the compound increases.For example, in the case of blue, the spectral transmittance increases near 450 nm, and in other wavelengths, the spectral transmittance decreases, that is, the absorption rate decreases. It will proceed in the direction of light. Therefore, if you want to cut off unwanted light such as the emission line spectrum that appears other than the emission main wavelength of the self-luminous body, you need to check the relative emission intensities of them and change c'to achieve the optimum spectral characteristics. There is.

Regarding the chromaticity, a triangle indicated by three points of green, red, and blue on the chromaticity diagram should be brought as close as possible to a target ideal color display, for example, the three primary colors such as the NTSC system. You can do it like this. Simulation of such color reproducibility is extremely important.

As described above, the materials for the three primary colors of red, green and blue are determined. As the colorants for the three primary colors, two pigments, an inorganic pigment and an organic pigment, are mainly used. The specific pigment names will be described.

Red pigments: There are inorganic pigments such as red iron oxide, insoluble azo pyrazolone red B, and azo lake lake red C, but especially when light resistance, heat resistance, migration resistance, etc. are required. Higher grade pigments such as quinacridone pigments such as Shincasia red and condensed azo pigments are useful.

Green pigment: phthalocyanine green (highly halogenated copper phthalocyanine), which is excellent in tinting strength and light resistance, is useful. This is a highly halogenated version of phthalocyanine blue and contains 14 to 16 Cl or Br. Further, phthalocyanine blue (copper phthalocyanine) and disazo yellow may be appropriately mixed and used for producing a green color. Among the disazo yellows, the disazo yellow HR is particularly useful because it has excellent light resistance and other resistances.

Blue pigment: A relatively inexpensive phthalocyanine blue which is excellent in tinting strength, light resistance and heat resistance is useful. Inorganic pigments such as navy blue, ultramarine, and cobalt blue dyed lake Victoria Pure Blue BO toner are also available.

It is easy to use if the above colorant is dispersed in a vehicle such as dimethyl silicone oil (a color-developing agent) to form an ink. Regarding such colorants, (1) clear color tone, (2) excellent dispersibility, (3) good migration resistance, (4) good heat resistance, It is important that (5) it does not interfere with the crosslinking of the silicone rubber, (6) it has good light resistance, and (7) it has no toxicity, and it is appropriate to consider these conditions, price, and spectral characteristics. Just select the one.

Regarding the spectral transmittance of the silicone rubber that serves as the matrix of the light-transmitting portion, it is extremely uniform and has a high transmittance in the visible wavelength range. Specifically, the silicone rubber having a thickness of 1 mm has a spectral range of 400 nm to 700 nm. It is desirable that the transmittance is 90% or more. Furthermore, it is desirable that the filler such as silica blended as a reinforcing agent is not included or is extremely small. This is effective in preventing Rayleigh scattering or Mie scattering that occurs when the filler reaches a secondary aggregation state or a pseudo-crosslinked state in the silicone rubber and becomes a particle having a size of about the wavelength or larger. Is. The thickness of the filter is also preferably 1 mm or less, and more preferably 0.5 mm or less for the above reasons.

The silicone rubber that satisfies the above-mentioned optical characteristics may be a millable type or a liquid type, but is preferably non-foaming type. The vulcanization type may be peroxide vulcanization or addition vulcanization, but it is desirable to avoid those that cause discoloration of the pigment or colorant during molding. In order to disperse the above-mentioned pigments and colorants in the uncured silicone rubber, the treatment may be carried out by a conventional method using a known kneader, three rolls or the like. Depending on the vulcanization type, a vulcanizing agent, a cross-linking agent, and a catalyst are added to and uniformly dispersed therein to obtain a mixture as a molding material for the light transmitting portion. Other necessary components can be added in each of the above steps.

A color filter is manufactured using the above-described materials for the dark colored or opaque light-shielding portion and the material for the light-transmitting portion, and a molding vulcanization step is included in the process. Molding may be performed by selecting an appropriate method such as mold pressing, casting, calender rolls, injection, extrusion, etc. For vulcanization, in addition to thermal vulcanization in the mold, hot air vulcanization (HAV), continuous A method suitable for the material may be selected such as vulcanization (CV, particularly steam vulcanization), room temperature vulcanization (RTV), low temperature vulcanization (LTV).

In the color filter of the present invention, it is important that the red, green, and blue light-transmitting portions are separated by a dark-colored or opaque light-shielding portion. In particular, the light-transmitting portion and the dark-colored portion are not colored. It is desirable that the opaque light-shielding portion is in a stripe shape, or is arranged in a triangle shape or a mosaic shape. Hereinafter, manufacturing of such a color filter will be described.

First, a thin plate-shaped rubber sheet is made from a molding material for each light transmitting portion of red, green and blue or a molding material for a dark colored or opaque light shielding portion. The method is as follows: 1) A method of injecting a material using liquid silicone rubber onto a carrier for transportation, transporting it into a mold, and then performing mold clamping molding to obtain a silicone rubber plate having a predetermined thickness. 2) A method in which a material using liquid silicone rubber is cast into a concave mold, conveyed to a hot press machine, and then clamp-molded to obtain a silicone rubber plate having a predetermined thickness. 3) A method in which the liquid silicone rubber material described above is molded into a block using a mold and heat press, and then a silicone rubber plate having a predetermined thickness is cut out by a known method using a knife blade, a rotary blade, or the like. 4) A method in which a millable rubber material is used to obtain a silicone rubber plate having a predetermined thickness according to the molding of 2) above. 5) A method of using a millable rubber material to obtain a silicone rubber plate having a predetermined thickness according to the molding of 3) above. And the like can be exemplified as a method for obtaining a rubber plate having good dimensional accuracy.

Next, the red, green, and blue silicone rubber plates obtained as described above and the dark colored or opaque silicone rubber plates are laminated and integrated. The method is as follows: After coating the surface of the colored rubber plate with transparent liquid silicone used as a matrix for the light-transmitting parts for red, green, and blue, sandwich a dark colored or opaque silicone rubber plate between the rubber plates of each color. Sequentially repeated stacking, heating or pressure heating, curing, adhesion and integration, and stacking in alternating multiple layers, red, green, blue order, green, blue, red order and blue, red, green order A method for obtaining each laminate. 2) Liquid silicone coated on the surface of each colored rubber plate in 1) above is used as a material for a dark colored non-colored or opaque silicone rubber plate. 3) A liquid silicone coated on the surface of each colored rubber plate in 1) above is used as a molding material for red, green, and blue, and is coated on the rubber plate of each color. Can be exemplified.

Each of the obtained alternate multiple layers is sliced into a predetermined thickness by a known method using a knife blade, a rotary blade or the like in a direction crossing the layering plane, and each of red, green, and blue translucent light is transmitted. A laminated sheet made of silicone rubber is obtained, the parts of which are separated by dark colored or opaque light-shielding parts. The width of the light-transmitting part and the dark colored or opaque light-shielding part cannot be numerically limited because it varies depending on the design of the self-luminous body to be combined, but the rubber plate is generally manufactured with a width of less than 2.0 mm. Sheets with calender rolls are suitable, and those with a diameter of 0.3 mm or more are suitable for molding with dies. However, when it is desired to suppress the accumulated pitch error as small as possible, the method of obtaining the silicone rubber plate described above is also useful. In addition, when obtaining a striped light-transmitting part, the method of obtaining the desired stripe width by combining multiple rubber plates with different thicknesses made by the method for obtaining the silicone rubber plate described above is also available. It is effective for improving accuracy.

If necessary, an ultraviolet reflective layer may be coated on the surface of the color filter, or a silicone-based adhesive may be coated on the side in contact with the light emitting surface of the self-luminous body. For the purpose of improving the antifouling property, a resin film such as polycarbonate having a non-glare hard coat surface may be attached to the visible side of the filter. However, when the film surface of polycarbonate or the like is directly exposed to sunlight, the possibility that it will turn yellow due to the ultraviolet rays contained in the sunlight increases, so its use is limited to indoor use.

The red, green, and blue arrangements of the color filters used in the present invention differ depending on the display method of the display device. When displaying a still image or character information, a stripe shape or a mosaic shape is displayed. It can be used as an array, and in the case of mainly displaying a moving image, a triangular array can be used. As shown in FIG. 1, the striped array is a striped pattern having a striped pattern formed by red, blue, and green translucent portions and dark colored or opaque light shielding portions. In the mosaic arrangement, as shown in FIGS. 5 to 6, red, green, and blue colored sheets are arranged while being separated by matrix-shaped dark colored or opaque light-shielding portions, and the upper row is shown. From the bottom to the bottom, the arrangement of each color is changed and arranged to form a mosaic section. Further, in the triangular array, as shown in FIGS. 8 to 9, red, green, and blue colored sheets are arranged while being separated by matrix-shaped dark colored or opaque light-shielding portions, Each color forms a triangle with a triangular cross section.

The silicone rubber color filter thus obtained has extremely good flatness followability, and since the dimensional accuracy is improved, the dispersion of the spectral characteristics can be minimized. It may be possible to omit the dark-colored or opaque light-shielding part having a large absorbance by the distance between the red, green, and blue of the self-luminous part, but from the viewpoint of visibility, it is better not to omit it. This is very advantageous because it improves the contrast and can absorb the light rays even when it is directly exposed to sunlight. Moreover, as a result of the increased purity of the emission color, color reproducibility is remarkably improved.

[0029]

【Example】

 Hereinafter, although the embodiments of the present invention will be described, the present invention is not limited to the embodiments, and many modifications can be made without departing from the spirit of the invention. Example 1 50 parts by weight of liquid silicone KE1934A [trade name, manufactured by Shin-Etsu Chemical Co., Ltd.] and KE1934B [same as above], 100 parts by weight in total, and a green pigment phthalocyanine lean (general commercial product) 0.15 part by weight was blended to prepare a green molding material. Similarly, 0.06 parts by weight of the red pigment Shincacia red (general commercially available product) and 0.12 parts by weight of the blue pigment phthalocyanine blue (general commercially available product) were added to the liquid silicone described above, respectively, to prepare a molding material for red and a molding material for blue. The material was prepared. Further, 4.0 parts by weight of the black colorant CP-96BLK [trade name, manufactured by Toray Dow Corning Silicone Co., Ltd.] was mixed with the liquid silicone described above to prepare a dark color molding material having a large absorbance.

These molding materials were cast into a concave mold that matched the size of the self-luminous portion of the display element and the size of the dark stripe, and after being transferred to a hot press machine kept at a temperature of 155 ° C., The mold was clamped and vulcanization was performed for 10 minutes. As a result, a dark-colored rubber plate having a thickness of 7 mm and a thickness of 1.5 mm having a large absorbance was obtained.

Next, on one surface of the green silicone rubber plate, the red silicone rubber plate, the blue silicone rubber plate, and the black silicone rubber plate thus obtained, KE1934A [same as above] and KE1934B [same as above]. ] 50 parts by weight of transparent liquid silicone is applied by screen printing as an adhesive, and then laminated one on top of the other so that the load applied to the top silicone rubber plate is 10 g / cm ^2. Then, the pressure was reduced to 5 Torr for 80 seconds. After removing air bubbles from the silicone adhesive layer in this manner, the silicone adhesive layer was left in an oven at 15 ° C. for 3 hours for curing and integration. As a result, a laminate having the structure shown in FIG. 1 (a) was obtained. This structure is black silicone rubber plate 4 '/ silicone adhesive layer 5 / green silicone rubber plate 1' / silicone adhesive layer 5 / black silicone rubber plate 4 '/ silicone adhesive layer 5 / red silicone rubber The plate 2 ′ / silicone adhesive layer 5 / black silicone rubber plate 4 ′ / silicone adhesive layer 5 / blue silicone rubber plate 3 ′ / silicone adhesive layer 5 is repeated.

The laminated body obtained above is sliced in a direction crossing the laminating plane to a thickness of 0.5 mm using a knife blade, and heat-treated at 225 ° C./60 minutes to further stabilize the physical properties of the filter. I went. As a result, a stripe-shaped silicone rubber color filter 7 having a cross-sectional structure in which the light-transmitting parts 1 to 3 of each color are separated by the black part 4 having a high absorbance as shown in FIG. 1B was obtained. The pitch of the repeating unit was 24 mm. In this example, a transparent silicone-based pressure-sensitive adhesive layer 6 was provided on one surface of the filter for the purpose of sticking to the self-luminous surface of the display element.

The green, red, and blue spectral transmittances of the obtained silicone rubber color filter were as shown in FIG. A self-recording spectrophotometer U-4000 manufactured by Hitachi, Ltd. was used for the measurement.

Example 2 As shown in FIG. 3, the color filter 7 shown in FIG. 1 (b) obtained in Example 1 was further coated with a polycarbonate film on the side where the silicone adhesive layer 6 was not provided. I glued the 8 pieces. As a result, the purity of the main emission color of the silicone rubber color filter was improved, and the visibility during daytime was also improved.

Example 3 Using the red, green, blue, and black silicone rubber plates and adhesives used in Example 1, curing and integration were performed under the same conditions, and as shown in FIGS. The laminated parts 11, 14, 16 having the structure shown in FIG. As shown in FIG. 4 (a), the structure of this laminated portion is as follows: black silicone rubber plate 4 '/ silicone adhesive layer (not shown) / red silicone rubber plate 2' / silicone adhesive layer (not shown). No.) / Black silicone rubber plate 4 '/ silicone adhesive layer (not shown) / green silicone rubber plate 1' / silicone adhesive layer (not shown) / black silicone rubber plate 4 '/ silicone adhesive Repeating layers (not shown) / blue silicone rubber plate 3 ′ / silicone adhesive layer (not shown). This laminated portion 11 was sliced with a knife blade 12 to a thickness of 7 mm to obtain a laminated sheet 13 in the order of red, green and blue. In addition, as shown in FIG. 4B, the laminated portion 14 is formed by repeatedly laminating black silicone rubber plates 4'so that the colored light transmitting portions are arranged in the order of red, green and blue in the order of green, blue and red. This was sliced with a knife blade 12 to a thickness of 7 mm to obtain a laminated sheet 15 in the order of green, blue and red. Further, as shown in FIG. 4C, the laminated portion 16 was laminated by changing the order of the colored light-transmitting portions to blue, red, and green in order, and the laminated sheet 17 was obtained in the same manner as above.

Next, the laminated sheets 13, 15 and 17 are repeatedly laminated with a black silicone rubber plate 4 ′ and a silicone rubber adhesive (not shown), and a load applied to the uppermost black silicone rubber plate 4 ′. Was kept at 10 g / cm ² and the pressure was reduced at 5 Torr for 80 seconds to remove air bubbles in the silicone rubber adhesive layer, and then the mixture was left in an oven at 155 ° C. for 3 hours for curing and integration. In this way, a laminated body 18 of laminated sheets shown in FIG. 5 was obtained. This laminate 18 was sliced to a thickness of 0.5 mm with a knife blade 12, and heat treatment was performed at 225 ° C / 60 minutes to further stabilize the physical properties of the filter. A mosaic-shaped color filter 19 made of silicone rubber, which was isolated in a matrix by the silicone rubber plate 4 ′, was obtained.

Example 4 First, the laminated sheet 13 shown in FIG. 4A of Example 3 was obtained in the same manner as above. Next, a black layer silicone rubber plate 14 'having a thickness half that of the black silicone rubber plate 4'and the red silicone rubber plate 1'is formed, which is the same as in Examples 1 to 3 above. The black material used in 1. was cast in a concave mold and pressure heat-molded for 10 minutes in a hot press machine kept at 155 ° C to obtain a 5.0 mm thick black layer silicone rubber plate 14 '. . This black layer silicone rubber plate 14 'was bonded at the beginning and at the end of the laminated body in which the red, green, blue and black silicone rubber plates 4'were laminated and adhered to obtain a laminated portion 20. This laminated portion 20 was sliced to the same thickness as the laminated sheet using a knife blade 12 to obtain a laminated sheet 21 as shown in FIG. Furthermore, the laminated sheet 13 and the laminated sheet 21 were repeatedly laminated with a black silicone rubber plate 4'and a silicone rubber adhesive (not shown), and curing and integration were performed under the same conditions as in Example 3, and then, as shown in FIG. A laminated body 22 of the laminated sheet shown was obtained. This laminated body 22 was sliced to a thickness of 0.5 mm by using a knife blade 12, and treated in the same conditions as in Example 3 in order to stabilize the physical properties of the filter, and the transparency of each color as shown in FIG. 9 was obtained. A silicone rubber color filter 23 having a triangular array of light portions was obtained.

[0038]

[Effect of device]

 The silicone rubber color filter of the present invention solves technical problems such as interference between primary colors, blurring of boundaries, accuracy, and pitch of repeating units, thus improving the purity of the main emitted color. However, visibility during daytime is also improved. In addition, it is possible to provide a color filter that can handle moving images, still images, character information, etc., is accurate and efficient, and has low cost and stable quality. Therefore, the effect of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 (a) is a perspective view showing a structural example of a laminate according to the present invention. (B) It is sectional drawing which shows the constructional example of the color filter of this invention.

FIG. 2 is a view showing an example of a color filter of the present invention in green,
It is a figure which shows each spectral transmittance of red and blue.

FIG. 3 is a cross-sectional view showing another structural example of the color filter of the present invention.

FIG. 4 is a processing diagram of a laminated sheet constituting another color filter of the present invention, (a) is a processing diagram of a laminated sheet in which red, green, and blue silicone rubber plates are laminated in this order, and (b) is a processing diagram. FIG. 3C is a processing diagram of a laminated sheet in which green, blue, and red silicone rubber plates are laminated in this order, and FIG. 7C is a processing diagram of a laminated sheet in which blue, red, and green silicone rubber plates are laminated in this order.

FIG. 5 is an explanatory view showing a structural example of another laminated body in the present invention.

FIG. 6 is a sectional view showing a structural example of another color filter of the present invention.

FIG. 7 is a processing diagram of a laminated sheet that constitutes another color filter of the present invention.

FIG. 8 is an explanatory view showing a structural example of another laminated body in the present invention.

FIG. 9 is a cross-sectional view showing a structural example of another color filter of the present invention.

[Explanation of symbols]

1'green silicone rubber plate, 1 green transparent part, 2'red silicone rubber plate, 2 red transparent part, 3'blue silicone rubber plate, 3 blue transparent part, 4'black silicone Rubber plate, 4 Black part with large absorbance, 5 Silicone adhesive layer, 6 Silicone adhesive layer, 7, 19, 23
Color filter, 8 polycarbonate film, 1
1,14,16,20 Laminated part 12 Knife blade 13,15,17,21 Laminated sheet 14 'Black layer silicone rubber plate 18,22 Laminated body

Claims (2)

[Scope of utility model registration request] 1. A light-transmitting portion made of red, green, and blue, wherein the light-transmitting portions made of red, green, and blue are separated from each other by a dark colored or opaque light-shielding portion. Silicon rubber color filter. 2. The silicone rubber color filter according to claim 1, wherein the light-transmitting portion and the dark colored or opaque light-shielding portion are arranged in a stripe shape, a mosaic shape or a triangle shape.