JPH0625918B2 - Anti-glare filter for display - Google Patents

Description

TECHNICAL FIELD The present invention relates to an antiglare filter to be mounted on the front surface of a display used for OA equipment or FA equipment, which has an antiglare property and adhesion to the display surface. The present invention relates to an antiglare filter having excellent properties.

[Prior Art] Recently, office automation in offices and factory automation in FAs are rapidly advancing, and the accompanying word processors, personal computers, control panels,
There is a problem of eye fatigue of a worker due to a display provided on an instrument panel and other devices, or mental fatigue that is considered to be caused by the fatigue, and measures for the worker are required.

The above-mentioned problems caused by the display given to the operator include the brightness peculiar to the display and the flicker of the image, the surface reflection light generated by irradiating the surface of the display with sunlight or indoor illumination light, and the display surface. This is because it is difficult to confirm the display image due to the image being reflected by the mirror effect. Therefore, a filter type antiglare plate, an antiglare filter, or a surface reflector (hereinafter, referred to as an antiglare filter) that is mounted on the front surface of the display to prevent reflection of surface reflected light or an image is commercially available. There is.

The antiglare filter as described above is generally a transparent substrate, for example, a surface of a hard plastic plate coated with antireflection, a polarizing plate closely adhered so as to be sandwiched between plastic plates, or a surface of a plastic plate. Dye with a dye, or add a dyeing material to the plastic material,
It is made of dyed plastic sheets.

On the other hand, a method of removing the surface reflected light out of the visual field by forming a continuous wedge so as to guide the surface reflected light generated by irradiating external light to one surface of the transparent plastic thin plate outside the visual field (JP-A-2000-242242). No. 56-133701), and an improved out-of-field removing device for surface reflection that reduces image movement and color generation by improving it by forming continuous wedges on both surfaces (Japanese Patent Laid-Open No. 57-1571).
Japanese Patent No. 65801) is proposed.

[Problems to be Solved by the Invention] The base material of an antiglare filter made of a commercially available transparent base is currently hard polymethylmethacrylate, polycarbonate, polystyrene, or glass. Since such an anti-glare filter is made of a hard material, it is mostly a rigid flat plate, and is mounted on the front surface of the display with a specific spacing, corresponding to the curvature of the convex spherical surface of the display surface or the curvature of the cylindrical surface. No curvature is given. Therefore, spaces having different intervals are partially formed between the display surface and the antiglare filter to be mounted. Therefore, the position of the operator who looks at the display, for example, the anti-glare effect decreases on the left and right sides with respect to the front of the display, and depending on the position of the operator,
The images and characters displayed on the display are bent,
There is a drawback in that it causes a lens effect, appears distorted, and becomes unclear. In addition, when the base material of the antiglare filter is made of a flexible material, for example, hard plastic, the polarizing film adhered when the antiglare filter is bent cannot follow the flexibility of the base material. There is a problem of easy peeling.

On the other hand, in the method or apparatus for removing surface-reflected light in which a continuous wedge is formed on the surface of the plastic thin plate as described above to form a wedge that guides the surface-reflected light out of the field of view, transparent plastic is used as the material. Glass is exemplified, and silicone rubber is mentioned as a flexible material that can be bent, even if it has low transparency. Thus, there is no concrete indication of a material having moldability, transparency and suitable flexibility for forming a continuous wedge on the surface.

The present invention has been made in view of the above-mentioned problems, and the present inventor has, as an antiglare filter for a display, a deformable material that can be adhered to the surface according to the curvature of the display surface. Various researches and studies have been conducted on a transparent plastic material which has flexibility and can easily form a continuous wedge-shaped surface on the surface of the substrate during molding as an antiglare filter, which is sufficient to produce an antiglare effect. As a result, certain polyurethanes can achieve the above objectives,
The inventors have found the fact that they are also excellent in abrasion resistance and chemical resistance and completed the present invention.

[Means for Solving the Problems] The present invention is characterized by comprising a transparent polyurethane elastomer film formed by a wedge-shaped surface having a continuous inclined surface and a vertical surface. A new filter is provided.

In the antiglare filter for a display of the present invention, the transparent polyurethane elastomer as a material of the filter is selected from the thermoplastic polyurethane elastomers or thermosetting polyurethane elastomers having transparency in known polyurethane elastomers. Thus, the polyurethane elastomer has flexibility or elasticity, but as the antiglare filter for a display of the present invention, it is preferable to select one having the following characteristics measured by JIS K6301 within the following numerical values. is there.

Tensile strength: 200 to 800 kg / cm ² Elongation: 5 to 700% Shore A hardness: 60 to 100 Here, since JIS K 6301 is a physical test method for vulcanized rubber, the above properties indicate flexibility or elasticity. It is used as an index. Thus, the polyurethane elastomer of the present invention has excellent adhesiveness to various display surfaces having different curvatures due to the above characteristic values, and therefore does not cause image distortion and has an antiglare property. Combined with the effect, the image becomes extremely clear and easy to see. If the characteristic value is deviated from the above value, the above-mentioned effect is deteriorated, and the image is distorted due to the damage due to bending at the time of mounting and the low adhesion.

Generally, a thermoplastic polyurethane elastomer is obtained as a so-called linear structure type polymer which is linearized by reacting a difunctional active hydrogen compound such as a polyol with a diisocyanate compound in an approximately equivalent amount, and has elasticity. It is known. The same applies to the thermoplastic polyurethane elastomer of the present invention.
As the difunctional active hydrogen compound, a relatively high molecular weight difunctional active hydrogen compound and a low molecular weight difunctional active hydrogen compound called a chain extender are usually used together. As the former, diols such as polyethers or polyesters having a molecular weight of about 800 to 6000 are suitable, but not limited thereto, and high molecular weight diols such as polycarbonates or polybutadienes can also be used. In the case of polyesters or polyethers as polyols, thermoplastic polyurethane elastomers composed of polyesters are preferable in that they can satisfy the above-mentioned characteristic values. Polyesters made from dibasic organic acids such as adipic acid and azelaic acid and glycols such as ethylene glycol, 1,4-butanediol and 1,6-hexanediol are commercially available and easily available. Can be done. Examples of such polyesters include polyethylene adipate, polybutyrea adipate, polyhexylene adipate, and polyethylene azelate. Further, as the ring-opening polymerized polyester diol, polylactones, particularly polyepsilon caprolactone can be exemplified. Polyethers include poly (oxytetramethylene) glycol and poly (oxypropylene) poly (oxyethylene) glycol. Suitable chain extenders are diols and diamines having a molecular weight of about 400 or less, especially about 200 or less. For example, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, isophoronediamine, MOCA and the like can be used. Usually, the hardness of the polyurethane elastomer is adjusted by the amount of the chain extender used, and the higher the amount of the chain extender, the harder the elastomer is obtained. Needless to say, the hardness can be adjusted by the kind of the bifunctional active hydrogen compound having a relatively high molecular weight. For example, the lower the molecular weight, the harder the elastomer can be obtained. The diisocyanate compound is not particularly limited, but suitable examples include non-yellowing diisocyanate compounds such as 4,4′-methylenebis (cyclohexyl isocyanate), isophorone diisocyanate, and hexamethylene diisocyanate. The thermosetting polyurethane elastomer is a polyurethane elastomer having a crosslink obtained by using a trifunctional or higher compound in at least one part of a polyfunctional active hydrogen compound and a polyisocyanate compound and reacting them in substantially equivalent amounts. The above-mentioned compounds are suitable as the bifunctional active hydrogen compound and the bifunctional polyisocyanate compound. As the trifunctional or higher functional high molecular weight active hydrogen compound, a polyol having a molecular weight of about 200 to 3000 per functional group is suitable. As the polyol, in addition to polyesters and polyethers, acrylic polyol and the like can be used. As the polyesters, those obtained by using, in addition to the above dibasic organic acid and glycol, a trihydric or higher polyhydric alcohol or a tribasic or higher organic acid as a raw material are preferable. It is preferable to use a trifunctional or higher polyhydric alcohol in combination. Examples of the polyhydric alcohol include glycerin, trimethylolpropane, hexanetriol, and pentaerythritol. As the trifunctional or higher functional polyether, those obtained by adding ethylene oxide or propylene oxide to a trifunctional or higher functional polyhydric alcohol or polyhydric phenol, or a polyamine having three or more aminic hydrogen atoms are suitable. Is. A trifunctional or higher functional low molecular weight active hydrogen compound (for example, a trihydric alcohol) called a cross-linking agent can be used together with a relatively high molecular weight difunctional and / or trifunctional or higher active hydrogen compound, but is not always required. Absent. When the active hydrogen compound having a relatively high molecular weight is a trifunctional or higher functional compound or a mixture thereof with a bifunctional functional compound, the bifunctional chain extender may be used in combination.

As the polyisocyanate compound, the above diisocyanate compounds are preferable. However, when the active hydrogen compounds are all difunctional, a trifunctional or higher functional polyisocyanate compound or a combination thereof with a diisocyanate compound may be used. Examples of trifunctional or higher polyisocyanate compounds include polyfunctionalized modified products of diisocyanate compounds and undecane triisocyanate.

The polyurethane elastomer is produced by the prepolymer method or the one-shot method using the above raw materials. In particular, producing a prepolymer having a terminal isocyanate group from a high molecular weight active hydrogen compound and a polyisocyanate compound,
A method of reacting this prepolymer with a chain extender or a crosslinking agent, that is, a prepolymer method is preferably used.

The method for producing the antiglare filter of the present invention when the above raw materials are used will be specifically described. When a thermoplastic polyurethane elastomer is used as a material, for example, in the reaction of a polyester with an isocyanate compound as a polyol, preferably, the polyester is preliminarily subjected to high-temperature vacuum treatment for dehydration and defoaming, and then mixed and reacted with an isocyanate compound to prepare a prepolymer. It is a polymer. In this reaction, it is preferable to add an organometallic compound such as an organotin compound or a metal chelate compound as a catalyst. The prepolymer obtained is added with a chain extender, poured into a film-forming mold in a heated state, heated and aged, and then released and cured to form a film made of a polyurethane elastomer. Is obtained.
An antiglare filter having a wedge-shaped surface is formed in the film-forming mold by processing the transfer surface so that a continuous wedge-shaped surface can be formed on one surface of the film. In addition, by using a die processed to form a continuous wedge-shaped surface of the obtained film made of the polyurethane elastomer, a wedge-shaped surface is formed on one surface of the film by, for example, press molding, and the wedge-shaped surface is formed. The anti-glare filter which it has can also be molded.

Also in the case of a thermosetting polyurethane elastomer, when the polyol of the material is a polyester, the same method as in the case of the above thermoplastic polyurethane elastomer is used. Also, when the polyol is a polyether, a film is formed by reacting the prepolymer with a crosslinking agent and by the same method as that for the polyester. Furthermore, the film can be formed by a one-shot method or the like without using a crosslinking agent or a chain extender. The continuous wedge-shaped forming method on one surface of the film is performed by the same method as in the case of the thermoplastic polyurethane elastomer described above to form an antiglare filter.

In the method for producing a thermoplastic polyurethane elastomer or a thermosetting polyurethane elastomer, the properties of the elastomer obtained by changing the types and blending ratios of the polyol and the isocyanate compound also change. For example, when the amount of the chain extender or the isocyanate compound for the high molecular weight polyol is increased, the elongation as a characteristic tends to decrease and the hardness tends to increase. Further, as the high molecular weight polyol has a lower molecular weight, the elongation tends to decrease and the hardness tends to increase. From these facts, an elastomer having suitable properties can be obtained by appropriately selecting the type and blending ratio of raw materials.

Thus, in the molded antiglare filter of the present invention, the wedge-shaped surface formed by the continuous inclined surface and the vertical surface formed on one surface will be specifically described with reference to FIG. FIG. 1 is a partially enlarged sectional view of an antiglare filter of the present invention. In the figure, the inclined surface 2 is provided on one surface of the filter body 1.
And the vertical surface 3 continuously form a wedge-shaped surface. The pitch P between the vertical surfaces is 0.05 mm to 0.5 mm, preferably
0.1 mm to 0.3 mm, and the angle θ of the inclined surface is 10 to 40 degrees, preferably 20 to 35 degrees. If the geometry of the wedge-shaped surface deviates from the above value, the antiglare effect is reduced. The thickness t of the filter body 1 is 0.05 mm to 1 mm, but the flexibility of the filter is appropriately maintained, and it is suitable for the adhesion to the display surface, and is also suitable for the transparency of the display image. When the vertical surface of the wedge-shaped surface formed on one surface of the filter is coated with a coloring paint and partially shielded from light, the antiglare effect and the contrast are improved. FIG. 2 is an enlarged partial sectional view of the antiglare filter in which the colored paint 5 is applied to the vertical surface 3 having the wedge shape as described above. Among such paints, the effect of being a black paint is remarkable. However, the color type is not particularly limited as long as it exhibits the above effect. As a material for the colored coating material, a material which is publicly known or commercially available as a polyurethane coating material in terms of adhesiveness of the coating material to a polyurethane elastomer is suitable.
A mixture of such a paint with a coloring agent such as carbon black may be used. Various methods are used for applying the coating material, and are not particularly limited.

In the antiglare filter of the present invention, the other surface 4 in which the wedge-shaped surface shown in FIG. 1 is not formed is flat, but there is no problem because it is sufficient for mounting on the front surface of the display and adhesion. Then, for the purpose of improving the direct release property to the front surface of the display, etc., it may be formed in a wedge-shaped surface, or may be provided with a minute uneven surface, an embossed surface, a curvature or the like.
Further, in addition to the shape as described above, the pressure-sensitive adhesive layer 6 is formed so that the adhesiveness can be further improved. In such a pressure-sensitive adhesive layer, it is preferable to protect the pressure-sensitive adhesive layer with another material, such as release paper, so that the pressure-sensitive adhesive layer appears when mounted on the display surface. Needless to say, the pressure-sensitive adhesive in the pressure-sensitive adhesive layer is composed of a suitable component in terms of adhesion to the display surface such as an acrylic polymer and layer forming property on the antiglare filter.

Although the antiglare filter of the present invention is made of a transparent polyurethane elastomer, it may be colored as long as the transparency can be maintained, and the color species of coloring may be appropriately selected in relation to the color tone of the display image, the brightness and the like. .

[Operation] Since the continuous anti-glare filter formed on the surface of the anti-glare filter of the present invention has a geometrical structure, the anti-glare filter functions to guide the reflected light of the external light emitted to the outside of the visual field. , Produces an antiglare effect. The effect does not change depending on the angle at which the display is viewed, and the distortion of the image does not occur because the filter can be in close contact with the display surface. It is considered that such adhesion to the display surface is caused by the flexibility, hardness, etc. defined by the material of the filter, particularly the specific characteristic value of the transparent polyurethane elastomer.

Example 1 100.0 g of polyethylene adipate having a molecular weight of 2018 and a hydroxyl number of 55.6 was degassed and dehydrated under vacuum at 110 ° C.
4'-methylene-bis (cyclohexyl isocyanate)
Add 53.3g and 0.01 of dibutyltin dilaurate,
A prepolymer was obtained by reacting at 80 ° C. for 15 minutes under a nitrogen stream. Next, the obtained prepolymer was kept at 70 ° C. to
4-Butanediol (13.4 g) was added, and the mixture was degassed under reduced pressure with stirring to prepare a continuous inclined surface (angle 35
Degree) and a vertical surface and a pitch of 0.3 mm, and the film was cast into a film forming mold made of a metal plate having a transfer surface capable of forming a wedge-shaped surface. The transfer surface of this film-forming mold is one in which a wedge-shaped surface is formed by grooving the electroplated surface. After the injection, the mixture was cured at 130 ° C for 15 hours. Thus, the molded body was released from the mold to obtain an antiglare filter having a thickness of about 1 mm, which was composed of a thermoplastic polyurethane elastomer film and had a wedge-shaped surface continuous to one surface thereof.

The obtained anti-glare filter was cut and adjusted into a shape corresponding to the spherical surface of a 14-inch large display and was brought into close contact with the surface, and the anti-glare effect was confirmed as follows. That is, the room light (angle 30W straight tube fluorescent lamp 2 is located above the display at a straight line distance of about 1.5 m and an angle of about 45 degrees and above the straight line distance of about 3 m.
A book is installed at a certain position, an antiglare test of reflected light due to room light, and an eye fatigue test of an operator by repeating the display work once for 2 hours three times a day.

As a result, in the anti-glare test of the reflected light due to the room light, no reflection of the room light was observed at the front of the display and at a gaze from the right and left 30 degrees. The image on the display could be read clearly, and the excellent antiglare effect was recognized. Next, in the eye fatigue test, it was reported that the operator could improve the efficiency without feeling any fatigue.

Separately, in the same manner as above, a film for forming a wedge-shaped surface on the transfer surface was used to obtain a film of a thermoplastic polyurethane elastomer without a wedge-shaped surface, the properties of which were measured, and the results are shown in Table 1. Indicated.

Example 2 A film of a thermoplastic polyurethane elastomer was prepared in the same manner as in Example 1 except that 100 g of polyepsilon caplacton having a molecular weight of 2011 and a hydroxyl value of 55.8 was used as the total amount of the polyol in place of the polyethylene acipate in Example 1. Thus, an antiglare filter and a film (having no wedge-shaped surface) were obtained.

When the antiglare test and the eye fatigue test of the obtained antiglare filter were conducted in the same manner as in Example 1, the same results as in Example 1 were obtained. Further, the properties of the film were measured and the results were as shown in Table 1.

Example 3 100.0 g of polyoxypropylenetriol having a molecular weight of 448 and a hydroxyl value of 37.8 was degassed and dehydrated at 110 ° C. under vacuum, and a buret-modified hexamethylene diisocyanate (“Sumijour N-3200”: Sumitomo Bayer Ltd.) was used. 100 g) and 0.006 g of dibutyltin dilaurate were added, and the mixture was reacted at 80 ° C. for 5 minutes while stirring and degassed under reduced pressure, and then poured into the same film forming mold as in Example 1,
It was cured at 130 ° C for 15 hours. The molded product was released from the mold to obtain an antiglare filter made of a thermoplastic polyurethane elastomer film. Further, a film having no wedge-shaped surface was similarly obtained.

When the antiglare test and the eye fatigue test of the obtained antiglare filter were conducted in the same manner as in Example 1, the same results as in Example 1 were obtained. Further, the properties of the film were measured and the results were as shown in Table 1.

Example 4 100.0 g of a polyester polyol (“Nipporan-4032”: manufactured by Nippon Polyurethane Co., Ltd.) consisting of diethylene glycol having a molecular weight of 2580 and a hydroxyl value of 60.9, trimethylolpropane and adipic acid was degassed and dehydrated at 110 ° C. under a vacuum. To this, 58.2 g of 4,4'-methylene-bis (cyclohexyl isocyanate) and 0.01 g of dibutyltin dilaurate were added and reacted at 80 ° C for 15 minutes under a nitrogen stream to obtain a prepolymer. Next, 6.8 g of ethylene glycol and 5.0 g of trimethylpropane were added to the prepolymer whose temperature was adjusted to 70 ° C., and degassing was performed under reduced pressure with stirring, and the mixture was poured into the same film forming mold as in Example 1 at 80 ° C. , 130 ℃
Cured for 15 hours. The molded product was released from the mold to obtain an antiglare filter made of a thermosetting polyurethane elastomer film. Further, a film having no wedge-shaped surface was similarly obtained.

When the antiglare test and the eye fatigue test of the obtained antiglare filter were conducted in the same manner as in Example 1, the same results as in Example 1 were obtained. Further, the properties of the film were measured and the results were as shown in Table 1.

Comparative Example 1 In Example 1, the display antiglare test and the eye fatigue test were performed in the same manner as in Example 1 without adhering the antiglare filter to the front surface of the display.

As a result, regarding the antiglare property, the fluorescent light of room light was reflected on the display surface, the light reflected on the surface entered the visual field, and the display image was unclear. In addition, in the display work, after the work for two hours once, the worker sees the indoor scenery as if it were colored through the green-yellow filter, and it takes a considerable amount of time for this condition to recover normally. It was reported that they did. It was also reported that the fatigue of the eyes was remarkable by repeating the work.

Examples 5 to 6 With respect to the antiglare filters obtained in Examples 1 and 3, a black paint was applied to the vertical surface of the wedge-shaped surface formed on the surface thereof by the following method. That is, a black paint prepared by mixing a polyurethane paint with a black pigment was transfer-applied by a pressing method and then dried to obtain an antiglare filter in which a vertical surface was painted black.

The obtained antiglare filter was subjected to an antiglare test and an eye fatigue test in the same manner as in Example 1. As a result, in all cases, the display image had improved contrast, and the image was extremely clear with an antiglare effect. In addition, it was reported that the workers did not feel tired at all due to the continuous display work.

[Advantages of the Invention] The antiglare filter of the present invention is made of a transparent polyurethane elastomer and has specific properties, for example, moderate flexibility, so that the surface of any curved display can be easily attached to the surface thereof. It has the characteristic of being in close contact.
Therefore, in the display work, the effect that the image is not distorted even when the eyes are gazed from the left and right sides is recognized. In addition, the characteristics also improve scratch resistance, are less likely to be scratched, and have excellent durability.

Regarding the antiglare property as an antiglare filter, since the reflected light of the external light applied to the display surface is directed to the outside of the visual field, it becomes a non-reflective surface and has excellent antiglare property. In particular, when the vertical surface of the wedge-shaped surface formed on the surface of the filter is coated with a coloring paint and partially shielded from light, an effect of improving anti-glare property and contrast is also recognized.

[Brief description of drawings]

FIG. 1 is a partially enlarged cross-sectional view of an anti-glare filter of the present invention, and FIG. 2 is a partially enlarged cross-sectional view of an anti-glare filter in which a colored paint is applied to a vertical surface of a wedge-shaped surface formed on the surface. Is. 1: Filter body, 2: Sloping surface 3: Vertical surface, 4: Surface where no wedge-shaped surface is formed 5: Colored paint, 6: Adhesive layer

Claims (3)

[Claims] 1. An antiglare filter for a display, comprising a transparent polyurethane elastomer film having a wedge-shaped surface, one surface of which is a continuous inclined surface and a vertical surface. 2. A transparent polyurethane elastomer is JIS K630.
The antiglare filter for a display according to claim 1, wherein the following characteristics measured by 1 are within the following numerical values. Tensile strength: 200 to 800 kg / cm ² Elongation: 5 to 700% Shore A hardness: 60 to 100 3. The antiglare filter for a display according to claim 1, wherein a vertical surface of a wedge-shaped surface composed of a continuous inclined surface and a vertical surface is coated with a coloring paint.