JP2004046258A - Anti-glare film and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antiglare film which has high surface glossiness prevention, transmitted image sharpness, and light transmissivity (total light-beam transmissivity) and also has high reflection preventiveness, and to provide a manufacturing method therefor. <P>SOLUTION: As cohesionless particles to be added to a resin, particles of specified size are used and the difference in refractive index between the resin and the particles is 0.05 to 0.15; and a good solvent and a poor solvent of a resin are used as solvent to obtain paint, which is applied onto a base film and dried; as the good solvent in a coating becomes less during drying to cause the particles and the resin to gel through the operation of the poor solvent to form excellent unevenness. The film is thus obtained to satisfy various properties required for the antiglare film. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to an antiglare film which is disposed on the front of a CRT display or a liquid crystal display and diffuses light entering the display from outside to reduce glare.

In a CRT display, accelerated electrons collide with a phosphor inside glass on the front surface to give energy, and the phosphor emits light, and usually, red, green, and blue light is emitted to the front side. In a liquid crystal display, the liquid crystal itself does not emit light, but is illuminated from the back in order to enhance the visibility of the liquid crystal image, so that the display as a whole emits light toward the front.
When a display is used indoors, illumination light such as a fluorescent lamp is incident on the display surface, and when the light is reflected, the screen becomes dazzling. In addition, the fluorescent lamp is reflected, so that it is difficult to recognize characters and the like. .

On a transparent substrate film, an anti-glare film formed by applying a resin coating containing silica to form a light diffusing layer is disposed on the front surface of the display, and diffuses external light that causes glare, causing glare of the screen. Relieving has already been done.
Conventional anti-glare films have irregularities on the surface of the light-diffusing layer due to aggregation of particles such as cohesive silica, and resin beads having a particle size larger than the thickness of the coating film are added to make the surface irregular. There is a product obtained by using a shaped film having irregularities on the surface, laminating it on the surface of a non-solidified coating film to transfer the irregular shape, and then peeling the shaped film.
Each of them has a light diffusion property, exhibits a certain degree of antiglare effect, and is easily applied to a display because of its thin film shape.
However, when the above-mentioned light emitted from the display to the front passes through this anti-glare film, a brilliant shine called scintillation is generated on the film surface, and the visibility of the display object is increased. There is a problem that decreases.
The performance of the anti-glare film disposed on the front of the display includes high anti-glare properties, high image clarity, high light transmittance (= total light transmittance), and light diffusion. It is important that the film has good anti-glare property (= high anti-reflection property of external light such as fluorescent lamps (reflection prevention property)). There was no.

The present invention has high anti-glare properties, clearness of transmitted images, total light transmittance, and anti-reflection properties, without significantly changing the conventional thin film-like shape as described above, and satisfies both points. It is an object to provide an anti-glare film and a method for manufacturing the same.

In the present invention, although the point of forming an antiglare film by applying a resin coating material in which particles are dispersed is common to the related art, a non-aggregating particle to be added to the resin has a specific particle size. A resin and particles having a refractive index difference of 0.05 to 0.15, a paint is formed using a good solvent and a poor solvent for the resin as a solvent, and the paint is applied on a base film and dried; As the good solvent in the coating film decreases, the particles and the resin gel due to the action of the poor solvent to produce good unevenness, and by obtaining in this way, various properties required for the diffusible film Was found to meet.

The first invention comprises at least a light-diffusing resin film in which non-aggregated light-transmitting fine particles are dispersed in a light-transmitting resin, wherein the light-transmitting fine particles have a particle size of 1.0 to 5.0 μm, The difference between the refractive index of light of the light-transmitting fine particles and the refractive index of light of the light-transmitting resin is 0.05 to 0.15, and the amount of the light-transmitting fine particles added to 100 parts by weight of the light-transmitting resin. 5 to 30 parts by weight, and the surface roughness of the light diffusing resin film is such that the center line average roughness (Ra) is 0.12 to 0.30, and the 10-point average roughness (Rz) is 1.0 to 2.2. The present invention relates to an antiglare film represented by No. 9.
The second invention relates to the anti-glare film according to the first invention, wherein the light diffusing resin film is laminated on a transparent substrate.
According to a third aspect, in the first or second aspect, the thickness of the light-diffusing resin film is 1 to 3 times the particle diameter of the light-transmitting fine particles. It is about a film.
The fourth invention relates to the anti-glare film according to the first invention or the second invention, wherein the image clarity is 80 to 300 and the reflection preventing property is 5 to 70.
A fifth invention relates to the antiglare film according to any one of the first to fourth inventions, wherein the translucent resin is obtained by curing an ionizing radiation curable resin.
A sixth invention comprises non-aggregated light-transmitting fine particles, a light-transmitting resin, and a good solvent and a poor solvent for the light-transmitting resin, and the particle size of the light-transmitting fine particles is 1.0 to 5 0.0 μm, the difference between the refractive index of light of the light-transmitting fine particles and the refractive index of light of the light-transmitting resin is 0.05 to 0.15, and the blending amount of each component with respect to 100 parts by weight of the light-transmitting resin However, the light-transmitting fine particles are 5 to 30 parts by weight, the combined solvent of the good solvent and the poor solvent is 20 to 1000 parts by weight, and the weight ratio of the good solvent to the poor solvent is 100/20 to 100. / 70 is applied on the substrate to be coated using the coating composition, and then dried, and the weight ratio of the good solvent to the light-transmitting resin is reduced, so that the light-transmitting fine particles and the light-transmitting fine particles are reduced. Gelling and solidification of the light-sensitive resin, causing irregularities on the coating film surface A method for producing the antiglare film which comprises bringing.
The seventh invention relates to a method for producing an antiglare film according to the sixth invention, wherein a translucent resin and a good solvent and a poor solvent selected from the following combinations are used. is there;
A combination of an acrylate resin and toluene, methyl ethyl ketone, ethyl acetate, n-butyl acetate, or cyclohexanone as a good solvent for the acrylate resin, and methanol, ethanol, n-butanol, or isopropanol as a poor solvent;
Cellulose-based resins, a combination of ethyl acetate, n-butyl acetate, acetone, or cyclohexanone as a good solvent for the cellulose-based resin, and methanol, ethanol, n-butanol, or isopropanol as a poor solvent,
Epoxy resin, methanol / toluene (“/” means mixed), ethanol / xylene, methyl ethyl ketone, ethyl acetate, n-butyl acetate, or methyl isobutyl ketone as a good solvent for the epoxy resin, and toluene as a poor solvent. A combination of xylene, cyclohexanone, or cyclopentane,
A combination of urea melamine resin and ethyl acetate, n-butyl acetate, n-butanol, n-hexyl alcohol as a good solvent for urea melamine resin, and toluene or xylene as a poor solvent, or
A combination of a urethane resin, ethyl acetate, n-butyl acetate, or methyl ethyl ketone as a good solvent for the urethane resin, and methanol or ethanol as a poor solvent.
The eighth invention relates to the method for producing an antiglare film according to the sixth or seventh aspect, wherein drying is performed at a temperature of 20 to 100 ° C.
In a ninth aspect, in the sixth to eighth aspects, the light-transmitting resin is an ionizing radiation-curable resin. And a method for producing an anti-glare film characterized by crosslinking and curing.

According to the first aspect, since the light-transmitting resin and the light-transmitting fine particles and the surface roughness are specified, the anti-glare film having such a resin layer has surface-glare preventing properties, transmitted image clarity, And high light transmittance (= total light transmittance), and excellent performance with high anti-reflection property.
According to the second invention, in addition to the effects of the first invention, since the transparent substrate is involved, there is an advantage in that it has strength and is easy to handle during manufacture and processing.
According to the third invention, in addition to the effects of the first or second invention, a durable anti-glare film is provided because it has a resin coating film thicker than the particle diameter of the fine particles as compared with the conventional one, and thus has durability. it can.
According to the fourth invention, in addition to the effects of any one of the first to third inventions, the image displayed on the display using the anti-glare film is clear, and the image can be used in an environment with external light or illumination. Also, sufficient visibility of the image can be obtained.
According to the fifth aspect, in addition to the effects of any one of the first to fourth aspects, since the ionizing radiation-curable resin composition is formed of a crosslinked and cured resin film, the anti-glare film has excellent physical and chemical properties. Film can be provided.
According to the sixth invention, an anti-glare film having desired irregularities is produced by controlling the type of good solvent / poor solvent, the mixing ratio, the drying temperature, etc., without necessarily being restricted by the particle size of the fine particles to be compounded. I can do it.
According to the seventh aspect, in addition to the effects of the sixth aspect, a solvent can be selected from among solvents having high general versatility to produce an antiglare film.
According to the eighth invention, in addition to the effects of the sixth or seventh invention, after forming irregularities using an ionizing radiation-curable resin, the resin is cross-linked and cured by irradiation with ionizing radiation, whereby physical and chemical properties are improved. An excellent antiglare film can be stably manufactured.

An embodiment of the present invention will be described with reference to FIG. 1. The antiglare film 1 of the present invention basically has a laminated structure in which a light diffusing resin film 3 is laminated on a transparent substrate 2. Is what it is. The light-diffusing resin film 3 contains light-transmitting fine particles 4 inside and has fine irregularities 5 on the surface.
In addition, since the transparent substrate 2 is an object to be applied when the light diffusing resin film 3 is formed by painting, it is necessary in most cases. However, the transparent substrate 2 is not used, and According to the casting method, a light-diffusing resin film 3 without the transparent substrate 2 is obtained according to a casting method in which a light-diffusing resin film 3 is formed by coating a surface of a base material having the light-diffusing resin film 3 and then peeling off. You can also.

The materials constituting the anti-glare film of the present invention, the compounding ratio of the materials, the surface roughness of the anti-glare film, and the solvent (good solvent, poor solvent) used in producing the anti-glare film of the present invention, and drying Will be sequentially described.

The non-aggregating light-transmitting fine particles constituting the anti-glare film of the present invention are transparent when dispersed in the light-transmitting resin due to the refractive index of light being very close to that of the light-transmitting resin described below. The particle diameter of the light-transmitting fine particles is preferably in the range of 1.0 to 5.0 μm. If the particle size is less than 1.0, sufficient light diffusibility does not occur even when added, and if the particle size exceeds 5.0 μm, sufficient image clarity and light transmittance cannot be obtained.
Specific examples of non-aggregating light-transmitting fine particles include styrene beads (refractive index; 1.60), melamine beads (refractive index; 1.57), and acryl beads (refractive index; 1.49) for organic substances. ), Acryl-styrene beads (refractive index; 1.54), polycarbonate beads, polyethylene beads, polyvinyl chloride beads, etc., among which styrene beads and acryl-styrene beads are preferable.
In addition, of the non-aggregated translucent particles, as the minerals, Si0 ₂ (refractive _{index; 1.5~2.0), Al-Si0 2} ( refractive index; 1.65), Ge0 ₂ ( Refractive index: 1.65) can be used, and among them, SiO ₂ is preferable.
Since the above-mentioned light-transmitting fine particles are all non-aggregating, an effective internal scattering property can be obtained due to the difference in refractive index from the light-transmitting resin, and it becomes possible to prevent surface frays.

As the translucent resin, those in which the ionizing radiation-curable resin is cross-linked and cured, those in which the ionizing radiation-curable resin is cross-linked and cured together with the solvent-drying type resin, particularly those using a thermoplastic resin as the solvent-drying type resin, Alternatively, a thermosetting resin is cured.

Among them, the range of ionizing radiation-curable resins includes mainly acrylate-based oligomers or prepolymers, and monofunctional or polyfunctional monomers. As oligomers or prepolymers, relatively low molecular weight polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, alkyd resin, spiro acetal resin, polybutadiene resin, polythiol polyene resin, or acrylate such as polyhydric alcohol or There is methacrylate (hereinafter, both are collectively referred to as (meth) acrylate).
The following monofunctional monomer or polyfunctional monomer may be added to these ionizing radiation-curable resins as a reactive diluent. Monofunctional monomers include ethyl (meth) acrylate, ethylhexyl (meth) acrylate, styrene, methylstyrene, and N-pyrrolidone, and polyfunctional monomers include trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, and trimethylolpropane. Propylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, or neopentyl glycol di ( (Meth) acrylates. In addition, these monofunctional monomers or polyfunctional monomers can be used alone and crosslinked and cured without the above-mentioned oligomer or prepolymer, or mixed with a thermoplastic resin or a thermosetting resin. It can also be used.

Examples of the solvent-drying type resin that may be added to the ionizing radiation-curable resin include, for example, nitrocellulose resin, acetylcellulose resin, cellulose acetate propionate resin, and mainly cellulose-based resin such as ethylhydroxyethylcellulose resin having high transparency. ,preferable.

As the thermosetting resin used as the translucent resin, phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin, epoxy resin, amino alkyd resin, urea melamine resin, or There are silicone resins and the like.
When a thermosetting resin is used, a crosslinking agent or a polymerization initiator is added as necessary.

In the antiglare film of the present invention, the difference in the refractive index of light between the light-transmitting fine particles and the light-transmitting resin needs to be 0.05 to 0.15. The refractive index of the translucent resin is about 1.5 in the case of ionizing radiation-curable resin, but in the case of other resins, if the refractive index of light is low, it is larger than the allowable difference in refractive index. In some cases, the transparency of the light-transmitting fine particles may decrease. In such a case, TiO ₂ (refractive index: 2.3 to 2.7), Y ₂ O ₃ (refractive index; 1.87), La, which are fine particles having a high light refractive index, are used with respect to the translucent resin. By adding ₂ O ₃ (refractive index; 1.95), ZrO ₂ (refractive index; 2.05), or Al ₂ O ₃ (refractive index; 1.63), etc., the refractive index of the translucent resin is increased. Can be adjusted to adjust the difference in the refractive index from the light-transmitting fine particles. This method is effective when inorganic light-transmitting fine particles are used.

The non-aggregating light-transmitting fine particles are added in a ratio of 5 to 30 parts by weight based on 100 parts by weight of the light-transmitting resin. If the amount of the non-aggregating light-transmitting fine particles is less than 5 parts by weight, sufficient light diffusing properties cannot be obtained, and thus the resulting antiglare film cannot have sufficient antiglare and antireflection properties. On the other hand, when the amount exceeds 30 parts by weight, the light diffusing property is improved, but the haze value (= haze value) is increased, the transmitted image definition is reduced, and the light transmittance (= total light transmittance) is reduced. There is a disadvantage of being lower.

防 The antiglare film of the present invention preferably has a surface roughness defined as follows. That is, the center line average roughness (Ra) is 0.12 to 0.30, and the 10-point average roughness (Rz) is 1.0 to 2.9. The center line average roughness (Ra) and the 10-point average roughness (Rz) are determined by a method defined by JIS B0601. Here, the center line average roughness (Ra) is 0.12 to 0.30, and the 10-point average roughness (Rz) is 1.0 to 2.9.

In the anti-glare film of the present invention, the thickness of the light-diffusing resin film is 1 to 3 times the particle size of the light-transmitting fine particles dispersed inside. The light-diffusing film of the present invention is obtained by the production method of the present invention using a good solvent and a poor solvent, as described later, because irregularities are caused on the surface of the coating film by a drying mechanism during the production. Even if the film thickness clearly exceeds the particle diameter of the fine particles and the fine particles are buried inside the light diffusing resin film, the antiglare film having the surface roughness as described above can be obtained.
Here, when the thickness of the light-diffusing resin film is smaller than the particle diameter of the light-transmitting fine particles dispersed therein, the surface irregularities become rough, and the anti-glare property decreases, and conversely, When the ratio exceeds 3 times, in order to obtain a good surface unevenness, the amount of added fine particles must be increased, and as a result, the haze value increases, and the transmission clearness and the total light transmittance decrease. .

The anti-glare film of the present invention has a particle size of the light-transmitting fine particles, a difference in refractive index between the light-transmitting fine particles and the light-transmitting resin, a blending ratio of the two, and a surface roughness. 80 to 300, and excellent performance with a reflection prevention property of 5 to 70 can be exhibited.
The transmitted image clarity is determined according to JIS K 7105, and the light transmitted or reflected by the sample is measured through a moving optical comb using an image clarity apparatus, and C is the transmitted image clarity (%) and M is the highest. When the wave height, m, is the lowest wave height, it is obtained by calculation according to the formula of C = (M−m) / (M + m) × 100.
The larger the value of the transmitted image sharpness C (%), the clearer and better the image. The apparatus used was an image clarity measuring instrument (ICM-1DP) manufactured by Suga Test Instruments Co., Ltd. Since there are four types of slit width of the optical comb, the maximum value is 100% × 4 = 400%.
In addition, the measurement of anti-reflection property is performed by applying a black adhesive tape to a non-concavo-convex surface of a light diffusing resin film serving as a sample to prevent light reflection on a back surface, holding the sample flat, and A parallel light beam of 5 mm square is incident from a direction of 10 ° with respect to the normal line, and the light beam reflected on the uneven surface of the light diffusing resin film from the regular reflection direction is observed by a CCD camera. The brightness of the peak is set to a certain value by adjusting the aperture of the CCD camera, and the angle of inclination of the brightness at the inflection point of the brightness at the edge portion of the captured light flux is used as the anti-reflection property. When a light beam is projected onto a mirror surface, the inclination of the luminance is almost equal to 90 °, but the inclination of the luminance is small on a mat surface having large irregularities.
In addition, “external light reflection” in the evaluation items of the antiglare films of Examples and Comparative Examples described later refers to the anti-reflection property thus obtained.

To produce the anti-glare film of the present invention, non-aggregated light-transmitting fine particles and a light-transmitting resin are blended, and these are not dispersed using a good solvent and a poor solvent for the light-transmitting resin. After dissolving to prepare a coating composition, applying the composition on a substrate to be applied, the composition is dried and cured.
In this coating composition, a solvent (a combination of a good solvent and a poor solvent is referred to as a solvent) is used in a ratio of 20 to 1000 parts by weight with respect to 100 parts by weight of a light-transmitting resin, and a ratio of good solvent / poor in the solvent is used. The solvent is blended so that the weight ratio of the solvent is 100/20 to 100/70.
Here, a good solvent refers to a solvent having excellent resin solubility and swelling degree, and a poor solvent refers to a solvent having poor resin solubility and easily causing gelation. Since all solvents are determined for each resin that is a solute, and whether the solubility is excellent or inferior, it is probably also relative, so a typical translucent resin and a good solvent and a poor solvent for that resin Examples of combinations of
A combination of an acrylate resin and toluene, methyl ethyl ketone, ethyl acetate, n-butyl acetate, or cyclohexanone as a good solvent for the acrylate resin, and methanol, ethanol, n-butanol, or isopropanol as a poor solvent;
Cellulose-based resins, a combination of ethyl acetate, n-butyl acetate, acetone, or cyclohexanone as a good solvent for the cellulose-based resin, and methanol, ethanol, n-butanol, or isopropanol as a poor solvent,
Epoxy resin, methanol / toluene (“/” means mixed), ethanol / xylene, methyl ethyl ketone, ethyl acetate, n-butyl acetate, or methyl isobutyl ketone as a good solvent for the epoxy resin, and toluene as a poor solvent. A combination of xylene, cyclohexanone, or cyclopentane,
A combination of urea melamine resin and ethyl acetate, n-butyl acetate, n-butanol, n-hexyl alcohol as a good solvent for urea melamine resin, and toluene or xylene as a poor solvent, or
A combination of a urethane resin, ethyl acetate, n-butyl acetate, or methyl ethyl ketone as a good solvent for the urethane resin, and methanol or ethanol as a poor solvent.
In the above combination, two or more solvents may be selected and used as a good solvent or a poor solvent for the translucent resin.

In this coating composition, the ratio of the solvent is 20 to 1000 parts by weight with respect to 100 parts by weight of the translucent resin. A small amount of a solvent may be used for a resin or a monomer having good solubility. However, when the solubility is relatively low or the viscosity is high even after dissolution, the amount of the solvent is increased.
If the amount of the solvent is less than the lower limit, the viscosity increases due to slight evaporation of the solvent or gelation occurs, which hinders use in the production.If the amount exceeds the upper limit, the solvent is dried. Requires a lot of energy.

Further, the ratio by weight of the good solvent / the poor solvent in the solvent is preferably from 100/20 to 100/70.
When the coating is performed using a coating composition in which the content of the poor solvent is less than the lower limit, most of the solvent is a good solvent, so that the entire solvent disappears quickly, and as a result, it is merely dried, and the Unevenness is less likely to occur. Further, when the poor solvent is blended in excess of the upper limit, the gelation proceeds from an early stage, and the resulting irregularities are likely to be rough, and the coating composition may gel during storage, and When the drying speed of the solvent is low, the coating film may not be easily dried.
The drying speed of the solvent can be based on the relative evaporation speed R of the solvent. The relative evaporation rate R of the solvent A is determined on the basis of the time required for n-butyl acetate to evaporate at room temperature, and R = [time required for n-butyl acetate to evaporate] / [solvent A evaporates. The larger the value, the faster the evaporation rate, and the smaller the value, the slower the evaporation rate.
As for the relative evaporation rate R of the good solvent and the poor solvent, the good solvent has a relative evaporation rate R of preferably 3.7 or less, and the poor solvent preferably has a relative evaporation rate R of 1.9 or less. . When a good solvent and a poor solvent are selected, it is better to select a good solvent having a relative evaporation rate R higher than that of the poor solvent. The relative evaporation rate R may be smaller in a good solvent than in a poor solvent, depending on the capacity of the dryer after applying the substance.

The solvent (a good solvent and a poor solvent are collectively referred to as a solvent) in a ratio of 20 to 1000 parts by weight and a ratio of good solvent / poor solvent in the solvent to 100 parts by weight of the translucent resin in the coating composition. When the weight ratio is 100/20 to 100/70, this coating composition does not have a drawback such as gelation during storage and can maintain a viscosity suitable for application.

Using the coating composition as described above, when forming a light diffusing resin film, as a material of the substrate to be applied, there is a transparent glass, transparent resin, if the latter film or sheet, or plate There is.
Transparent resins include those in which some or all of the hydroxyl groups of cellulose are mainly esterified with lower fatty acids, such as acetyl cellulose and cellulose acetate butyrate, typically cellulose triacetate. In addition, various polyesters (typically, polyethylene terephthalate = PET), acrylics (typically, polymethyl methacrylate), polyurethane, polycarbonate, polymethylpentene, (meth) acrylonitrile, polyethersulfone, polysulfone, or polyether Ketones and the like can also be used.
Among the above, when a transparent resin film is used, coating can be performed continuously, and the obtained antiglare film has flexibility and is easily adapted to various uses. Is more preferable. The thickness of the transparent resin film is usually 25 to 1000 μm.
In addition, it is possible to form a light-diffusing resin film without forming a substrate by peeling after forming the light-diffusing resin film by making the surface of the substrate to be applied peelable. As described above, due to the relationship between the material of the substrate to be coated and the material of the light-diffusing resin film, the adhesiveness is poor, and there is a case where it is not particularly necessary to provide the releasability. Alternatively, a method of applying a film on a metal mirror surface or the like to form a film and then peeling the film may be used.

Application of the coating composition to the substrate to be applied can be performed by a general coating or printing technique. Roll coating, gravure roll coating, spray coating, curtain flow coating, pouring, kiss coating Examples thereof include a coating method such as a spin coating method using a spinner wheeler, or a brush coating method, and a printing method such as gravure printing or silk screen printing.

When drying is performed after coating on the substrate to be coated, the surface of the coating film becomes uneven as the drying proceeds.
Drying starts when the coating composition is applied on the substrate to be applied by a coating technique or a printing technique. Drying is usually accomplished by blowing and / or heating, under which conditions the solvent evaporates little by little.
When the solvent in the coating composition decreases, the translucent resin near the surface that had been dissolved by the action of the good solvent until then begins to gel due to the presence of the poor solvent, and the translucent resin near the coating film surface Lumps composed of translucent fine particles occur. When gelling, the drying rate of the good solvent is higher than that of the poor solvent, or the drying temperature is higher, or the amount of air blown, the more the solvent decreases, the more the solvent decreases, and the translucent resin and translucent Agglomeration of fine particles occurs suddenly and forms relatively large irregularities, but the drying rate of a good solvent is not so large as that of a poor solvent, or the drying conditions are slower, the solvent in the coating composition decreases. Speed becomes slow, and relatively fine irregularities are formed.
Further, as the amount of the good solvent in the coating composition is smaller, gelation occurs more rapidly and relatively large irregularities are formed.
That is, according to the production method of the present invention, by adjusting the difference between the drying rate of the good solvent and the drying rate of the poor solvent, the drying conditions, and the ratio of the good solvent in the solvent, the unevenness formed on the coating film surface is reduced. Since the size can be controlled and the size of the light-transmitting fine particles does not determine the unevenness of the coating film surface, different sizes of unevenness can be formed even if the same size of light-transmitting fine particles are used. There are advantages that can be done.

(4) The state in which the surface of the coating film is gelled due to unevenness is solidified by continuing drying, or cured by a method according to the resin component of the coating composition used. If it is a thermosetting resin, it is further heated if necessary, and if an ionizing radiation-curable resin is used, it is cross-linked and cured by irradiation with ionizing radiation.

(Example 1)
The following materials were mixed in predetermined amounts and mixed well to prepare a coating composition having the following composition for forming a light-diffusing resin film.
Translucent resin 100 parts by weight Pentaerythritol triacrylate (Nippon Kayaku Co., Ltd., PET30)
5 parts by weight of photoinitiator (Irgacure 184, manufactured by Ciba Geigy)
Transparent fine particles 8 parts by weight Filler made of polystyrene resin (particle size: 1.3 μm, refractive index: 1.6)
Good solvent 60 parts by weight Methyl isobutyl ketone (Relative evaporation rate R; 1.6)
Poor solvent 15 parts by weight isobutyl alcohol (relative evaporation rate R; 0.64)
As a substrate to be coated, a cellulose triacetate film (manufactured by Fuji Photo Film Co., Ltd., TD-80U, thickness 80 μm) was prepared, and one surface of the film was coated with the coating composition obtained above by a roll coating method. The coating film was dried at a temperature of 50 ° C. to form irregularities on the surface of the coating film, and then irradiated with 120 mJ of ultraviolet rays to cure the coating film to obtain an antiglare film.

(Other Examples and Comparative Examples)
Regarding Examples 2 to 7 and Comparative Examples 1 to 4, the coating composition in which the translucent resin and the photoinitiator in Example 1 and the blending amounts thereof were left as they were, and the translucent fine particles and the solvent were changed. And the film thickness and the drying temperature were changed each time.
In Comparative Example 5, only pentaerythritol triacrylate was applied to a shaping film having irregularities on its surface so as to have a thickness of 3 μm, cured, and then peeled off.
The following Table 1 and Table 2 show the differences from Example 1 in each example and each comparative example.

The evaluation results of the antiglare films obtained in each of the above Examples and Comparative Examples are shown in Tables 3 and 4 below.
In Tables 3 and 4, however, “face-to-face” refers to a staggered arrangement (or triangular arrangement) on a backlight for a liquid crystal display (a LIGHTBOX 45 manufactured by HAKUBA) and a color filter having a pitch of 150 μm. (However, in order to avoid the effect of color, use only a black matrix and use a non-colored filter on each pixel.) Overlap the uneven surface of the antiglare film at a position 160 μm away from the color filter surface. The standard deviation of the luminance variation when the film surface was observed with a CCD camera was fixed while being fixed to the observation side.

Example 1 and Example 2 differ only in the drying temperature, and the one obtained in Example 1 in which the drying temperature is low has finer irregularities, so that the surface roughness and the transmission image sharpness are different. (Hereinafter, and sometimes in the table, it may be abbreviated as sharpness.) Further, the one obtained in Example 2 having a higher drying temperature has a rougher surface, so that the sharpness is lower and the haze is slightly higher, but the anti-reflection property is better.
In Example 3, since the ratio of the poor solvent was increased as compared with Example 1, the drying temperature was the same as in Example 1, but it was coarser than Example 2 in which the temperature was increased. As a result, the sharpness is lower and the haze is higher, but the anti-reflection property is further improved.
In Example 4, half of the fine particles were added with fine particles having a refractive index of 1.5 close to the resin, so that the haze was reduced and the sharpness was slightly increased, but the internal haze was reduced. Although numerically inferior to Example 1, these values are practically sufficient.
In Examples 5 to 7, the particle size of the fine particles and the solvent were changed, but the performance of the obtained antiglare film shows the same good performance as that obtained in Example 1 and the like.

In Comparative Example 1, since only the good solvent was used as the solvent, unevenness was unlikely to occur, and the surface was almost flat, so that the surface and sharpness were good, but the anti-reflection property was not good.
In Comparative Example 2, since only the poor solvent was used as the solvent, frosted glass-like rather rough irregularities were generated, the light transmittance was reduced, and the sharpness was extremely low.
In Comparative Example 3, although the transmittance was high, the sharpness was low, and the surface roughness was inferior to that of Example 1.
In Comparative Example 4, the sharpness is poor. It is good in terms of anti-reflection properties.
Comparative Example 5 is different from the examples and other comparative examples in that an uneven shape is formed using a shaping film, and fine particles are not added, so that the transmittance and the sharpness are good. It is not good in terms of preventing reflection.

It is sectional drawing of an anti-glare film.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Anti-glare film 2 Transparent base material 3 Light diffusing resin film 4 Translucent fine particle 5 Fine unevenness

Claims (5)

At least non-aggregated light-transmitting fine particles are formed of a light-diffusing resin film dispersed in a light-transmitting resin,
The light-transmitting fine particles have a particle size of 1.0 to 5.0 μm,
A difference between the refractive index of light of the light-transmitting fine particles and the refractive index of light of the light-transmitting resin is 0.05 to 0.15,
The amount of the light-transmitting fine particles added to 100 parts by weight of the light-transmitting resin is 5 to 30 parts by weight,
The translucent resin is obtained by curing an ionizing radiation curable resin,
As the surface roughness of the light diffusing resin film, the center line average roughness (Ra) is 0.12 to 0.30, and the ten-point average roughness (Rz) is 1.0 to 2.9. The anti-glare film. The anti-glare film according to claim 1, wherein the light diffusing resin film is formed on a transparent substrate. The antiglare film according to claim 1 or 2, wherein the thickness of the light diffusing resin film is 1 to 3 times the particle diameter of the light transmitting fine particles. The antiglare film according to any one of claims 1 to 3, wherein the image sharpness is 80 to 300 and the anti-reflection property is 5 to 70. The anti-glare film according to any one of claims 1 to 4, wherein the translucent resin is obtained by curing an ionizing radiation-curable resin.

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