JP2009139465A - Optical component and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of optical component by which the coverage of a substrate can be enhanced with an antiglare layer. <P>SOLUTION: The antiglare layer is formed on the substrate by using an inkjet device having a plurality of nozzles for ejecting ink. The antiglare layer is formed by repeating a dot molding process by a plurality of times, and in the dot molding process, a nozzle to be used is selected from among the plurality of nozzles; and at the same time, ink is ejected onto the substrate, dots 2a (or 2b) are formed in random arrangement on the substrate and, thereafter, the dots are hardened. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical component having an antiglare layer used for various displays and optical devices, and a method for producing the same.

  In recent years, the use of video equipment, information equipment, and portable equipment has been rapidly expanding both at home and in the office. Each device is equipped with a display, and the recent trend is to increase the screen size and the image quality. With an increase in size and an increase in image quality, improvement in visibility has been demanded so as to make it easier to see. Generally, an optical film on which an antireflection layer or an antiglare layer is formed is attached to the front surface of the display. In particular, an antiglare layer is effective for preventing reflection of external light, and various types of antiglare layers have been studied.

  The antiglare layer is provided with irregularities at an appropriate size and pitch on the surface, and the formation method is by transfer or embossing, by adding fine particles to the coating liquid, die coating method or spin coating method, A wet process such as a dip coating method has been put into practical use. The formation of the antiglare layer by transfer or embossing has problems that it is expensive to produce and maintain the roll, is inferior in productivity, and it is extremely difficult to form a fine uneven structure. Although the formation of the antiglare layer by the wet process is excellent in terms of cost and mass productivity, it is necessary to disperse the fine particles appropriately without causing uneven coating in order to effectively form the desired protrusion. It has the problem that it is extremely difficult to realize it over a large area.

Recently, the formation of an antiglare layer by an ink jet method, which is a kind of wet process, has begun to be studied. This ink jet method forms protrusions by curing ink landed on a substrate as it is. For example, Patent Document 1 describes that dots are formed in a random arrangement on a substrate using an inkjet apparatus, and the antiglare layer is formed by curing the dots. Patent Document 1 discloses a method of applying vibration to a head portion of an ink jet apparatus and a method of ejecting ink from an arbitrary nozzle as methods for randomly arranging dots.
JP 2004-151642 A

  However, in the method of applying vibration to the head portion of the inkjet device, the ink ejected from the head portion falls to a close position and adjacent dots are mixed together, forming not only fine protrusions but also large flat protrusions. Sometimes. When such a large and flat protrusion is formed, the antiglare property at that portion is lowered. On the other hand, in the method of ejecting ink from an arbitrary nozzle, adjacent dots do not mix with each other, but in order to randomly arrange the dots on the substrate, the nozzles are located at some distance from each other. Since it is necessary to use a nozzle, the distribution density of dots becomes small, and the coverage of the base material by the antiglare layer cannot be made too high. And in such an optical component whose coverage is not so high, the influence of the reflection by the surface of a base material is large, and reflection cannot be suppressed very much.

  In view of such circumstances, it is an object of the present invention to provide an optical component manufacturing method capable of increasing the coverage of a base material with an antiglare layer and an optical component obtained by the manufacturing method.

  In order to achieve the above object, the present invention is a method of manufacturing an optical component by forming an antiglare layer on a substrate using an inkjet apparatus having a plurality of nozzles for discharging ink, A dot forming step of curing the dots after ejecting the ink onto the base material and forming dots in a random arrangement on the base material while selecting a nozzle to be used from the plurality of nozzles is performed a plurality of times The manufacturing method of the optical component which forms the said glare-proof layer by repeating is provided.

  The present invention also includes a base material and an antiglare layer formed on the base material, and the antiglare layer is arranged on the base material at random, and the same antiglare property-imparting composition. An optical component in which at least some of the dots are overlapped with each other in a state where the ridge lines overlap and the vertices are independent in the cross section is provided.

  According to said method, since a random dot pattern comes to be overlaid by repeating a dot shaping | molding process in multiple times, the coverage of the base material by an anti-glare layer can be improved. Moreover, once the dots are cured, the dots are formed again, so that the dots formed earlier and the dots formed later do not mix, and each forms a protrusion, and a large flat protrusion is formed. There is no. That is, according to the present invention, it is possible to obtain an optical component in which the base material is covered with a high coverage by the antiglare layer having a large number of fine protrusions. With such an optical component, reflection can be effectively suppressed.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional view showing an example of an optical component manufactured by the manufacturing method according to Embodiment 1 of the present invention. In FIG. 1, the optical component is composed of a base material 1 and an antiglare layer 2. The substrate 1 is transparent and is a plastic film made of tempered glass having a thickness of 1 to 3 mm, PET (polyethylene terephthalate), TAC (triacetyl cellulose), acryl, polyimide, or the like having a thickness of 50 to 200 μm. The antiglare layer 2 formed thereon is composed of an antiglare property-imparting composition formed by an ink jet method. The antiglare property-imparting composition is composed of a thermosetting resin such as cellulose ester resin or polycarbonate resin, or an ultraviolet curable resin such as acrylate resin or silicone resin, as will be described in detail later. In the case of a plastic film, the hardness is lower than that of glass and the scratch resistance is inferior. Therefore, a hard coat such as a high-hardness thermosetting resin or an ultraviolet curable resin is provided between the base material 1 and the antiglare layer 2. Sometimes a layer is provided.

  The formation of the antiglare layer 2 by the ink jet method is performed by ejecting and applying ink from the head assembly onto the substrate 1 using an ink jet apparatus employing the antiglare imparting composition as ink, and further curing the ink. Do. The head assembly is composed of a plurality of head modules, and the head module is composed of an assembly of a plurality of head cells. FIG. 2 is a schematic diagram of a head cell used in this embodiment and each embodiment described later. The head cell A is a basic component of the head module and further of the head assembly. The head cell A includes a pressure chamber partition 3 made of SUS, a piezoelectric actuator B disposed on the pressure chamber partition 3, and a nozzle plate 4 disposed below the pressure chamber partition 3.

  The piezo actuator B has a structure in which a piezo element 5 is sandwiched between electrodes 6. The material of the nozzle plate 4 is SUS, and the surface on the discharge surface side is subjected to water repellent treatment, and a nozzle 7 having a diameter of 20 μm to 30 μm is opened here. The pressure chamber C is a portion surrounded by the pressure chamber partition wall 3 and the piezoelectric actuator B.

  First, the ink 8 made of the antiglare property-imparting composition is introduced into the pressure chamber C. By applying a voltage from the electrode 6 to the piezo element 5 disposed on the pressure chamber C, pressure is applied to the ink 8 in the pressure chamber C, and the ink 8 is ejected as fine droplets 9 from the nozzle 7. At this time, by adjusting the vibration frequency and the number of pulses applied to the piezo element 5 and the pulse waveform thereof, and further optimizing the nozzle shape and the like, the size of the liquid droplet ejected from the nozzle 7 is changed to a diameter of 10 to 10. Control to 100 μm. In this way, the ink jet method ejects ink made of a composition for imparting antiglare properties as fine droplets from minute nozzles and lands on the substrate to form dots, and forms the uneven structure by curing the dots. To do. That is, the anti-glare layer 2 having a large number of protrusions is formed by the dots as they are. The diameter of the landed dot is generally larger than the diameter of the droplet, and a small dot is formed from a small droplet and a large dot is formed from a large droplet. In addition, since the dot diameter varies depending on the substrate temperature, the solvent content, etc. even with the same droplet diameter, the ink material and process conditions are optimized. The average center-to-center distance between adjacent protrusions is preferably 20 to 120 μm, the height of each protrusion is 0.1 to 5 μm, and the coverage of the base material 1 by the antiglare layer 2 is preferably 35 to 100%. Each dot is required to be randomly arranged in order to prevent generation of interference fringes due to interference between light reflected by the dots. This is a random pattern data (for example, data consisting of 0 and 1 elements, and the arrangement is random matrix data) created by a personal computer, converted into a discharge on / off signal and sent to the head assembly, Finally, by applying a voltage based on an on / off signal to the piezo actuator B of each head cell A, dots can be formed on the substrate in a random arrangement similar to the pattern data.

  In this embodiment, the piezo method is adopted because of the wide selection of materials, but a so-called bubble jet (registered trademark) method that generates ink by heating ink and a thermal method can also be used.

  FIG. 3 is a schematic diagram of a head module D in which a plurality of head cells A in FIG. 2 are connected. This is a schematic view of the head module D as seen from the ejection surface side. Although only the nozzle plate 4 and the nozzle 7 are shown in the figure, the pressure chamber C and the piezo actuator B are formed on the back side corresponding to each nozzle 7. The head module D has, for example, a rectangular shape with a width of 1.5 cm and a length of 4.5 cm. In the head module D, 500 nozzles 7 having a diameter of 20 μm are formed so as to be arranged in a line at a pitch P of 40 μm in the longitudinal direction. By appropriately selecting the nozzles 7 that eject ink, it is possible to eject minute droplets at a pitch that is an integral multiple of the narrowest 40 μm pitch. FIG. 4 is a schematic view of a head assembly E having a plurality of head modules D in FIG. In the head assembly E, a plurality of head modules D are arranged in a staggered manner in order to cope with a wide area application, and the nozzles 7 are continuously arranged at a pitch P in a predetermined direction (hereinafter referred to as “Y direction”). They are arranged in a straight line. In the present embodiment, a head assembly E composed of 25 head modules D is employed for coating with a width of 50 cm. However, the number of modules is not limited to this, and may be determined according to the width of the substrate.

  Next, a method for manufacturing an optical component by the ink jet method will be described in detail. This manufacturing method is characterized by repeating the dot forming step a plurality of times using the same antiglare-imparting composition as ink. Here, the dot forming step is to form a dot in a random arrangement on the base material 1 by ejecting ink onto the base material 1 while selecting the nozzle 7 to be used from the plurality of nozzles 7, and thereafter A series of steps for curing dots. The ink is discharged onto the substrate 1 while the substrate 1 is being conveyed.

  FIG. 5 shows how ink is ejected onto the substrate 1 using the head assembly E of FIG. For example, an inkjet apparatus including a head assembly E composed of 25 head modules D is placed in a room in which temperature and humidity and cleanliness are controlled. In particular, the viscosity of the ink, which is an anti-glare property-imparting composition, is strongly influenced by the ambient temperature, thereby changing the shape of the dots formed on the base material 1. The part is strictly controlled so that the temperature change is within ± 2 ° C. The substrate 1 is a tempered glass having a size of 50 cm in length and 85 cm in width and 3 mm in thickness. The substrate is not limited to this, and may be a plastic film such as PET, TAC, or acrylic. Further, the size and thickness shape are not limited to this, and are determined according to the purpose and the device. The surface of the base material 1 is cleaned in advance through ultraviolet irradiation or contact with a discharge gas in the previous step. Thereby, the adhesive strength between the base material and the antiglare layer can be secured. In this embodiment, the surface treatment of the base material 1 is performed for 1 to 2 minutes using a surface modification apparatus using short wavelength ultraviolet rays of 185 nm or 254 nm. On the surface-treated substrate 1, ink composed of the antiglare property-imparting composition is ejected by an ink jet method.

  The antiglare property-imparting composition is composed of a polymerizable organic compound, an organic solvent, and an additive. The polymerizable organic compound is a compound having an unsaturated bond such as a vinyl group or an allyl group and cured by radical polymerization, or a compound cured by cationic polymerization such as siloxane. In this embodiment, a silicone resin, which is an ultraviolet curable resin, is used. However, a thermosetting resin can be used as long as the curing temperature does not affect the physical properties of the substrate. The organic solvent is appropriately selected from hydrocarbons, alcohols, ketones, esters, glycol ethers, and other organic solvents, or a mixture thereof. In general, when a solvent is added, the range in which the dot size and height can be adjusted is expanded. In this embodiment, ethanol, isopropyl alcohol, diacetone alcohol, carbitol acetate, methyl lactate, PGME (propylene glycol monomethyl ether acetate), PGMEA (propylene glycol monomethyl ether acetate), decalin, etc. Selected. Some polymerizable organic compounds have a low viscosity without the addition of a solvent, but in this case, it is not necessary to add a solvent as long as it can be discharged. The additive is mainly a curing catalyst. The ink made of such an antiglare property-imparting composition has, for example, a viscosity of 3 to 15 mPa · s and a surface tension of 20 to 40 dyne / cm, and has a material configuration and a mixing ratio that can be stably applied by an ink jet method. .

  Next, the coating conditions by the inkjet system of the antiglare property-imparting composition will be described. The distance between the ejection surface of the head module and the substrate is, for example, about 0.8 mm, and spherical droplets are formed therebetween. The droplets preferably have a diameter of about 20 μm and a volume of 3 to 4 pL. In the application with the generated droplets, the head assembly E and the substrate 1 are arranged in parallel, the head assembly E is fixed, and the substrate is orthogonal to the Y direction (hereinafter referred to as “X direction”) (hereinafter referred to as “X direction”). Move to the left side in FIG. Thereby, as shown in FIG. 5, application | coating with a droplet is performed in the predetermined area | region 1a of the part which passed under the head assembly E of the base material 1. FIG. In the predetermined region 1a, the dot forming process by applying droplets is performed a plurality of times.

  First of all, the dot pitch is determined from the dot size on the appropriate substrate to be landed. Since the dot size varies depending on the type and amount of the solvent, the surface treatment of the substrate, and the temperature, it is confirmed in advance. The dot size can be confirmed by stopping the substrate 1 and discharging one drop with a one-shot signal, curing it, and observing with an optical microscope. For example, the surface treatment of the substrate and the type and amount of the solvent may be selected so that dots having a diameter of 30 to 35 μm, 65 to 75 μm, and 140 to 150 μm are formed.

  There are two types of dot pitch, the pitch in the X direction and the pitch in the Y direction. The dot pitch in the Y direction is adjusted by specifying which of the nozzles of the head module is to be ejected. That is, when the nozzle pitch P is 40 μm, the dot pitch in the Y direction is 40 μm when ejected from all nozzles, 80 μm when ejected every other nozzle, 120 μm when ejected every other nozzle, and every third. When discharged, it becomes 160 μm. Thus, a dot pitch that is an integral multiple of the nozzle pitch P can be realized. When the dot pitch approaches or falls below the dot size, adjacent dots merge to form a large dot. To avoid this, the dots touch each other with a margin between the dot pitch and the dot size. It is preferable not to do so. However, if an excessive margin is provided, the coverage is lowered and the antiglare effect is lowered accordingly. Therefore, an optimum range is obtained. For example, the dot pitch in the Y direction is 40 μm when the dot size is 30 to 35 μm, 80 μm when the dot size is 65 to 75 μm, and 160 μm when the dot size is 140 to 150 μm. Then, the nozzles that are arranged at intervals of a constant multiple of the pitch P are specified as nozzles that can be used to realize the determined dot pitch. For example, when the dot pitch in the Y direction is 40 μm, it is specified as a nozzle that is arranged at an interval of one pitch P, that is, a nozzle that uses all nozzles. When the dot pitch in the Y direction is 80 μm, the pitch P It is specified as a nozzle that uses nozzles arranged at double intervals. Similarly, when the dot pitch in the Y direction is 160 μm, it is specified as a nozzle that uses nozzles arranged at intervals of four times the pitch P.

  The dot pitch in the X direction is basically the same length as the dot pitch in the Y direction. That is, when the dot pitch in the Y direction is 40 μm, the dot pitch in the X direction is also 40 μm. The dot pitch in the X direction is adjusted by the discharge interval and the substrate conveyance speed. That is, when the discharge interval is fixed at 500 μsec, the substrate conveyance speeds are 8 cm / sec, 16 cm / sec, 24 cm / sec, and 32 cm / sec, respectively, thereby obtaining dot pitches of 40 μm, 80 μm, 120 μm, and 160 μm, respectively. Alternatively, when the substrate conveyance speed is fixed at 32 cm / sec, the dot intervals of 40 μm, 80 μm, 120 μm, and 160 μm can be obtained by setting the discharge interval to 125 μsec, 250 μsec, 375 μsec, and 500 μsec.

  After determining the dot pitch in the X direction and the Y direction and specifying the nozzle to be used, random pattern data is created by the personal computer described above so that the specified nozzle is arbitrarily selected. In other words, the number of columns of the matrix pattern data matches the number of identified nozzles (nozzles arranged at intervals of a fixed multiple of the pitch P). Note that the number of rows of pattern data is determined by the size of the substrate 1. Since continuous ink ejection is performed a plurality of times, pattern data is created for the number of times. Hereinafter, the case where the dot size is 65 to 75 μm and the dot pitch is 80 μm will be mainly described with reference to FIGS. 6A and 6B. The straight line in the figure indicates the dot pitch. In each ejection, ink is ejected from nozzles arbitrarily selected from the nozzles identified based on the created pattern data. FIG. 6A shows a dot pattern formed by the first ejection, and the dots 2a are randomly arranged. FIG. 6B shows a dot pattern formed by the second ejection, and the dots 2b are randomly arranged in a pattern different from the first one.

  The coverage of each of the first discharge and the second discharge is 20 to 30%. 7 and 8 show the case where the first discharge and the second discharge are repeated on the same substrate. At this time, the dot 2a formed in the first time and the dot 2b formed later overlap in some cases, but the gap between the dots 2a formed in the first time is filled with the dots 2b formed in the second time. It becomes like this. For this reason, for example, when the overlap margin is 5%, the coverage of the base material by the antiglare layer increases to 35 to 55%. That is, in the optical component obtained by this manufacturing method, at least some of the dots overlap each other with the ridge lines overlapping and the vertices independent in the cross section. Needless to say, when the discharge is further repeated, the coverage gradually increases to 100%, but the number of repetitions is determined by the required performance. For example, if the dot molding process is repeated three times, the coverage is 50 to 80%, and if the dot molding process is repeated four times, the coverage is 65 to 100%.

  After each discharge, drying and curing are performed each time. In order to evaporate the solvent in the dots, methods such as blowing hot air, heating with a heater, and using radiant heat such as an infrared lamp can be used. The above drying methods are carried out alone or in combination according to the characteristics of the solvent, and the method of applying heat is carried out under the optimum conditions from the dot side, from the back side, or both. In the present embodiment, natural drying was performed by leaving it at room temperature for 1 minute. However, when the ratio of the high boiling point solvent is large, it is dried in an oven at 50 to 100 ° C. for 1 to 3 minutes.

After drying, the dots formed by an ultraviolet curing device having a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like are cured. At this time, the irradiation time is 3 to 10 seconds, and the integrated light quantity is 200 to 1500 mJ / cm ² . Under these conditions, the dots are fully cured and adhere firmly to the substrate.

  The anti-glare optical component is completed through the above steps. In this embodiment, the surface treatment of the base material and the type and amount of the solvent are selected so that the dot diameter is 30 to 35 μm, 65 to 75 μm, and 140 to 150 μm. Thus, an optical component was manufactured by repeating the dot molding process twice. The obtained optical component is measured for transmitted light by the method described in “Testing method for optical properties of plastic” in JIS K7105-1981 (measured through an optical comb that moves transmitted and reflected light). Evaluation of image sharpness and sharpness and visibility obtained by measurement of reflected light were performed. The result is indicated by point c in FIG. The point c is when the dot diameter is 65 to 75 μm, but when the dot diameter is 30 to 35 μm and 140 to 150 μm, it can be plotted at substantially the same position, so these are omitted.

  In an optical component in which the dot forming process is performed only once, as shown by a point b in FIG. 11, the image is reflected with almost no decrease in transmission image definition with respect to the optical characteristics (point a) of the base material alone. It was possible to reduce the degree of blurring (image clarity of reflection). Furthermore, in the optical component manufactured by repeating the dot forming process twice by the manufacturing method of the present embodiment, an effect that seems to be due to the improvement in the coverage ratio was obtained, and the reflection degree could be further reduced.

  This method has an advantage that the antiglare layer can be directly formed on the glass substrate and the cost can be reduced. On the other hand, it can be formed on a film or sheet, but in that case, it is necessary to adhere the film or sheet to a glass substrate with an adhesive.

(Embodiment 2)
In the manufacturing method of Embodiment 2, a low refractive index layer is further formed on an antiglare layer using an ink jet device, and FIG. 9 is a cross-sectional view of an optical component manufactured by this manufacturing method. In FIG. 9, the base material 1 is the same material as in the first embodiment. An antiglare layer 2 is further laminated thereon, and a low refractive index layer 11 is further laminated thereon, and the antiglare antireflection effect is obtained by these two layers. Each layer is formed by two types of material compositions corresponding to the respective layers, that is, an anti-glare imparting composition and a low refractive index layer forming composition, which are individually applied by an ink jet method and then cured. The

  Next, the production of the antiglare antireflection film having this two-layer structure will be described. The formation of the first antiglare layer 2 is the same as that of the first embodiment, and the material composition and process for discharging and curing the ink made of the antiglare property imparting composition by the ink jet method are the same as those of the first embodiment. The details are omitted because they are common. Here, the formation of the low refractive index layer 11 will be described.

  The composition for forming a low refractive index layer used here is composed of a polymerizable organic compound, low refractive fine particles, an organic solvent, and an additive. In order to achieve a low reflectance, it is important to use low refractive fine particles having a low refractive index and to reduce the polymerizable organic compound as much as possible. The polymerizable organic compound, that is, the binder is a compound having an unsaturated bond such as a vinyl group or an allyl group and cured by radical polymerization, or a compound cured by cationic polymerization such as siloxane. In this embodiment, a silicone resin, which is an ultraviolet curable resin, is used. However, a thermosetting resin can be used if the curing temperature is within a range that does not affect the physical properties of the substrate. The low-refractive fine particles are inorganic fine particles such as hollow spherical silica, magnesium fluoride, and calcium fluoride, or organic fine particles made of a fluororesin, and have a particle size of 10 to 100 nm and a refractive index of 1.35 to 1.45. is there. In this embodiment, organic fine particles of a fluororesin having a refractive index of 1.35 to 1.40 are used. When particles larger than 200 nm are used, the above range is appropriate because clogging tends to occur at the nozzle. In addition, there is no problem in using a polymer having a fluorine-containing crosslinked structure as a binder and low refractive material. The organic solvent is appropriately selected from hydrocarbons, alcohols, ketones, esters, glycol ethers, and other organic solvents, or a mixture thereof. In the present embodiment, a mixture of ethanol, isopropyl alcohol, propylene glycol monomethyl ether, and diacetone alcohol is used. Additives include curing catalysts, surfactants, surface tension modifiers, and the like.

  The ratio of the fine particles to the binder is 0.5 to 2 parts by mass of the binder with respect to 1 part by mass of the fine particles. Increasing the amount of the binder improves the adhesion to the substrate after curing, but on the other hand, the refractive index of the low refractive index layer is lowered, so that the balance is determined in consideration. The organic solvent has the highest weight ratio of 92 to 96%, and the other materials, that is, the combination of the polymerizable organic compound, the low refractive fine particles, and the additive are the remaining 4 to 8%. One reason for this low concentration design is that clogging at the nozzle tends to occur as the mass ratio of other materials increases, and another reason is that This is because, in the case of the concentration, coating is performed with a relatively thick film, and the controllability and management of the film thickness are facilitated. The ink made of the composition for forming a low refractive index layer thus prepared has a viscosity of 3 to 15 mPa · s and a surface tension of 20 to 40 dyne / cm, for example, and can be stably applied by an ink jet method. It is a ratio. A low refractive index layer may be formed by a sol-gel method using an antireflective composition made of a metal alkoxide material, but at this time, a high temperature of 200 to 300 ° C. is required for the reaction, so that there are restrictions on the usable substrate. is there.

  Next, the coating conditions of the composition for forming a low refractive index layer by the ink jet method will be described. The application is performed in the same manner as the application for forming the antiglare layer in FIG. That is, an inkjet apparatus having a head assembly E composed of, for example, 25 head modules placed in a room in which temperature and humidity and cleanliness are controlled is used. Similarly, the head and the material supply system are managed so that the temperature change is within ± 2 ° C. An anti-glare layer 2 has already been formed on the substrate 1, and then the surface of the anti-glare layer 2 and the low refractive index layer 11 is improved by irradiation with ultraviolet rays or contact with a discharge gas in order to improve the adhesion between the anti-glare layer 2 and the low refractive index layer 11. Wash. In the present embodiment, the surface treatment of the antiglare layer 2 is performed for 1 to 2 minutes using a surface modification apparatus using short wavelength ultraviolet rays of 185 nm or 254 nm.

  On the surface-treated antiglare layer 2, an ink composed of a composition for forming a low refractive index phase is formed by an ink jet method. The distance between the ejection surface of the head module and the substrate is, for example, about 0.8 mm, and spherical droplets are formed therebetween. The droplet is preferably about 30 μm in diameter and 15 pL in volume. Application by the generated droplets is performed by arranging the head assembly E and the substrate 1 in parallel, fixing the head assembly E, and moving the substrate in one of the X directions. The low refractive index layer 11 calculates | requires the conditions where the dot which landed so that it might become a continuous film | membrane should be connected. For this purpose, first, the base material 1 is stopped, one drop is ejected with a one-shot signal, cured, and observed with an optical microscope to obtain the dot size. Next, the dot pitch for landing the droplets, that is, the dot pitch in the traveling direction (X direction) and the head direction (Y direction) is determined. At this time, a continuous film can be obtained by setting the dot pitch to a dot size or less. In the ink comprising the composition for forming a low refractive index layer of the present embodiment, the dot size is 100 to 200 μm, and the dot pitch in the Y direction is determined by the nozzle interval, but 40 μm or 80 μm is adopted from the above conditions, For the dot pitch in the X direction, a condition that is easy to manage is selected from 1 μm to 100 μm that satisfies the above conditions. The dot pitch in the X direction can be uniquely determined by the discharge interval and the substrate conveyance speed. For example, to set the dot pitch to 4.8 μm, the discharge interval is 80 μsec and the substrate conveyance speed is 6 cm / sec. .

  The coating thickness is 1 to 10 μm, and the thickness can be adjusted by the dot pitch in the X direction and the Y direction, the number of driving pulses of the actuator, and the driving voltage. In this embodiment, the coating thickness is mainly 2 to 5 μm, and the cured thickness is 70 to 120 nm, so-called optical film thickness (the optical film thickness is defined by the product of the refractive index of the layer, n, and film thickness d. It is adjusted so that it is in the vicinity of λ / 4.

  After coating, the coating film is dried and cured. In order to evaporate the solvent in the coating film, methods such as blowing hot air, heating with a heater, and using radiant heat such as an infrared lamp can be used. Depending on the characteristics of the solvent, the above drying methods are carried out alone or in combination, and the method of applying heat is carried out under optimum conditions from the coating surface side, from the back side, or both. In this embodiment, in order to avoid coating unevenness due to rapid drying, natural drying was performed by leaving it at room temperature for 1 minute. However, when the ratio of the high boiling point solvent is large, it is dried in an oven at 50 to 100 ° C. for 1 to 3 minutes.

After drying, the coating film is cured by an ultraviolet curing device having a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like. At this time, the irradiation time is 3 to 10 seconds, and the integrated light quantity is 200 to 1500 mJ / cm ² . Under these conditions, the coating film is sufficiently cured and adheres firmly to the substrate with the antiglare layer.

  An optical component having an antiglare antireflection film is completed through the above steps. The film strength of the completed optical component was 3H in pencil hardness, and the refractive index of the low refractive index layer was 1.35 to 1.40. In the same manner as in the first embodiment, the image definition and the degree of transfer (sharpness and visibility) were evaluated. The result is indicated by a point d in FIG. The optical characteristic (point d) of the optical component in which the antiglare layer and the low refractive index layer are formed on the optical characteristic (point a) of the base material alone is reflected without reducing the image clarity of transmission. The embedding degree was improved, and it was possible to further reduce the degree of embedding. Also, it was confirmed that no interference fringes were observed in a wide area even in observation with a three-wavelength fluorescent lamp.

  In the second embodiment, since the low refractive index layer 11 is formed using an ink jet device, optical components can be continuously produced with a simple device.

(Embodiment 3)
In order to further reduce the reflectivity, it is generally known that it is effective to use a multilayer structure, optimize the refractive index and film thickness of each layer, and interfere and cancel the surface reflected light and interface reflected light. In the manufacturing method of Embodiment 3, an anti-glare layer is further laminated with two antireflection films using an ink jet device, and FIG. 10 is a cross-sectional view of an optical component manufactured by this manufacturing method. . In FIG. 10, the base material 1 is the same material as that of the first embodiment. An anti-glare layer 2 is further formed thereon, and a high-refractive index layer 12 and a low-refractive index layer 11 are further stacked thereon, and the anti-glare antireflection effect is obtained by these three layers. Each film is coated with three types of material compositions corresponding to each film, namely, an anti-glare imparting composition, a high refractive index layer forming composition and a low refractive index layer forming composition individually by an ink jet method. And then cured.

  Next, production of an antiglare antireflection film having a three-layer structure will be described. The formation of the first antiglare layer 2 is the same as that of the first embodiment, and the material composition and process for discharging and curing the ink made of the antiglare property imparting composition by the ink jet method are the same as those of the first embodiment. Therefore, the details are omitted. Here, the formation of the high refractive index layer 12 will be described. The composition for forming a high refractive index layer used here is composed of a polymerizable organic compound, highly refractive fine particles, an organic solvent, and an additive. In order to realize low reflection, the high refractive index layer 12 should have a high refractive index. For this purpose, it is important to use fine particles having a higher refractive index and to minimize the polymerizable organic compound as much as possible. . The polymerizable organic compound is a so-called binder that is compatible with the highly refractive fine particle material. Generally, the polymerizable organic compound has a unsaturated bond such as a vinyl group or an allyl group and is cured by radical polymerization, siloxane, etc. And the like that are cured by cationic polymerization. In this embodiment, a silicone resin, which is an ultraviolet curable resin, is used. However, a thermosetting resin can be used as long as the curing temperature does not affect the physical properties of the substrate. The highly refractive fine particles are inorganic fine particles such as titanium dioxide, zirconium oxide, indium oxide, tin oxide, and ITO, and the particle diameter thereof is 10 to 100 nm and the refractive index is 1.65 to 2.20. In this embodiment, inorganic fine particles of titanium dioxide having a refractive index of 1.80 to 2.20 are used. When particles larger than 200 nm are used, clogging tends to occur at the nozzle, which should be avoided as in the second embodiment. The organic solvent is appropriately selected from hydrocarbons, alcohols, ketones, esters, glycol ethers, and other organic solvents, or a mixture thereof. In this embodiment, a mixture of ethanol, isopropyl alcohol, propylene glycol monomethyl ether, and diacetone alcohol is used. Additives include curing catalysts, surfactants, surface tension modifiers, and the like. The ratio of the fine particles to the binder is 0.5 to 2 parts by mass of the binder with respect to 1 part by mass of the fine particles. Increasing the amount of the binder improves the adhesion to the substrate after curing, but on the other hand, the refractive index of the high refractive index layer is lowered, so that the balance is determined in consideration. The organic solvent has the highest mass ratio of 92 to 96%, and the other materials, that is, the combination of the polymerizable organic compound, the highly refractive fine particles, and the additives are the remaining 4 to 8%. This low density design is one reason that clogging in inkjet heads tends to occur as the mass ratio of other materials increases, and another reason. This is because, when the concentration is low, the coating is performed with a relatively thick film, and the controllability and management of the film thickness are facilitated. The ink made of the composition for forming a high refractive index layer thus prepared has a viscosity of 3 to 15 mPa · s and a surface tension of 20 to 40 dyne / cm, for example, and can be stably applied by an ink jet method. It is a ratio.

  Next, the application conditions of the composition for forming a high refractive index layer by the ink jet method will be described. The application is performed in the same manner as the application for forming the antiglare layer in FIG. That is, an inkjet apparatus having a head assembly E composed of, for example, 25 head modules placed in a room in which temperature and humidity and cleanliness are controlled is used. As in 2, the head and the material supply system are managed so that the temperature change is within ± 2 ° C. An anti-glare layer 2 is already formed on the base material 1, and then the surface of the anti-glare layer 2 and the high refractive index layer 12 is improved by irradiation with ultraviolet rays or contact with a discharge gas in order to improve the adhesion between the anti-glare layer 2 and the high refractive index layer 12. Wash. In the present embodiment, the surface treatment of the antiglare layer 2 is performed for 1 to 2 minutes using a surface modification apparatus using short wavelength ultraviolet rays of 185 nm or 254 nm. An ink material of a high refractive composition is formed on the surface-treated antiglare layer 2 by an ink jet method. The distance between the ejection surface of the head module and the substrate is, for example, about 0.8 mm, and spherical droplets are formed therebetween. The droplet is preferably about 30 μm in diameter and 15 pL in volume. Application by the generated droplets is performed by arranging the head assembly E and the substrate 1 in parallel, fixing the head assembly E, and moving the substrate in one of the X directions. The high refractive index layer 12 calculates | requires the conditions which a dot connects so that it may become a continuous film | membrane. For this purpose, first, the base material 1 is stopped, one drop is ejected with a one-shot signal, cured, and observed with an optical microscope to obtain the dot size. Next, the dot pitch for landing the droplets, that is, the dot pitch in the traveling direction (X direction) and the head direction (Y direction) is determined. At this time, a continuous film can be obtained by setting the dot pitch to a dot size or less. In the ink comprising the high refractive index layer forming rate composition of the present embodiment, the dot size is 100 to 200 μm, and the dot pitch in the Y direction is determined by the mezzle interval, but 40 μm or 80 μm is adopted from the above conditions. The dot pitch in the X direction is selected from 1 μm to 100 μm that satisfies the above conditions and is easy to manage. The dot pitch in the X direction can be uniquely determined by the discharge interval and the substrate conveyance speed. For example, to set the dot pitch to 4.8 μm, the discharge interval is 80 μsec and the substrate conveyance speed is 6 cm / sec. .

  The coating thickness is 1 to 10 μm, and the thickness can be adjusted by the dot pitch in the X direction and the Y direction, the number of driving pulses of the actuator, and the driving voltage. In this embodiment, the coating thickness is mainly 2 to 5 μm, and the thickness after curing is 60 to 90 nm, so-called optical film thickness (the optical film thickness is defined by the product of the refractive index of the layer, n, and film thickness d. It is adjusted so that it is in the vicinity of λ / 4.

  After coating, the coating film is dried and cured. In order to evaporate the solvent in the coating film, methods such as blowing hot air, heating with a heater, and using radiant heat such as an infrared lamp can be used. Depending on the characteristics of the solvent, the above drying methods are carried out alone or in combination, and the method of applying heat is carried out under optimum conditions from the coating surface side, from the back side, or both. In this embodiment, in order to avoid coating unevenness due to rapid drying, natural drying was performed by leaving it at room temperature for 1 minute. However, when the ratio of the high boiling point solvent is large, it is dried in an oven at 50 to 100 ° C. for 1 to 3 minutes.

After drying, the coating film is cured by an ultraviolet curing device having a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like. At this time, the irradiation time is 3 to 10 seconds, and the integrated light quantity is 200 to 1500 mJ / cm ² . Under these conditions, the coating film is sufficiently cured and adheres firmly to the substrate with the antiglare layer. The high refractive index layer after curing had a film strength of 3H in pencil hardness and a refractive index of 1.65 to 1.80.

  Next, the low refractive index layer 11 is formed thereon. Before that, in order to improve the adhesion with the low refractive index layer 11, the surface of the high refractive index layer 12 is irradiated with ultraviolet rays or discharge gas. Clean the surface with contact. In this embodiment, the surface treatment of the base material is performed for 1 to 2 minutes using a surface modification apparatus using short wavelength ultraviolet rays of 185 nm or 254 nm.

  On the surface-treated high refractive index layer 12, an ink composed of a composition for forming a low refractive index layer is applied by an ink jet method. Since the material composition and process at this time are the same as those in the second embodiment, details thereof are omitted. Drying and curing of the applied composition for forming a low refractive index layer (coating film) is the same as in the second embodiment, whereby the third low refractive index layer 11 is formed.

  An optical component having an antiglare antireflection film is completed through the above steps. Similar to the first and second embodiments, the image definition and the degree of reflection (sharpness and visibility) were evaluated. The result is indicated by a point e in FIG. The optical properties (point e) of the anti-glare layer, the high refractive index layer, and the low refractive index layer formed on the optical properties (point a) of the substrate reduce the image clarity of transmission. The degree of reflection was improved without any further reduction, and could be further reduced as compared with the second embodiment. Also, it was confirmed that no interference fringes were observed in a wide area even in observation with a three-wavelength fluorescent lamp.

  According to the present invention, an anti-glare optical component having excellent visibility and sharpness without optical interference unevenness can be obtained, and a simple and small production facility capable of forming an anti-glare layer in the atmosphere. Therefore, the present invention is extremely useful for the production of optical components because the process is simplified compared to the die coating method, production tact time is shortened, high throughput can be realized, and as a result, it can be manufactured at low cost. It is.

It is sectional drawing of the optical component manufactured by the manufacturing method which concerns on Embodiment 1 of this invention. It is a schematic diagram of the head cell of the inkjet apparatus used for the manufacturing method which concerns on Embodiment 1 of this invention. FIG. 3 is a schematic diagram of a head module in which a plurality of head cells of FIG. 2 are connected. FIG. 4 is a schematic diagram of a head assembly having a plurality of head modules of FIG. 3. FIG. 5 is an explanatory diagram showing how ink is ejected onto a substrate using the head assembly of FIG. 4. (A) is a figure which shows the dot pattern formed by discharge of the 1st ink, (b) is a figure which shows the dot pattern formed by discharge of the 2nd ink. It is a figure which shows a dot pattern when Fig.6 (a) and FIG.6 (b) are overlapped. It is sectional drawing of the optical component manufactured by repeating a dot shaping | molding process twice. It is sectional drawing of the optical component manufactured by the manufacturing method which concerns on Embodiment 2 of this invention. It is sectional drawing of the optical component manufactured by the manufacturing method which concerns on Embodiment 3 of this invention. It is a figure which shows the optical characteristic of an optical component.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Anti-glare layer 2a, 2b Dot 3 Pressure chamber partition 4 Nozzle plate 5 Piezo element 6 Electrode 7 Nozzle 8 Ink 9 Droplet 11 Low refractive index layer 12 High refractive index layer A Head cell B Piezo actuator C Pressure chamber D Head Module E Head assembly P Pitch

Claims (14)

A method of manufacturing an optical component by forming an antiglare layer on a substrate using an inkjet apparatus having a plurality of nozzles for discharging ink,
A dot forming step of curing the dots after ejecting the ink onto the base material and forming dots in a random arrangement on the base material while selecting a nozzle to be used from the plurality of nozzles is performed a plurality of times The manufacturing method of the optical component which forms the said glare-proof layer by repeating.   The plurality of nozzles are arranged at a predetermined pitch, and in the dot forming step, nozzles arranged at intervals of a fixed multiple of the pitch are specified from the plurality of nozzles, and any of the specified nozzles is arbitrarily selected. The method of manufacturing an optical component according to claim 1, wherein the ink is ejected from a nozzle selected in step 1.   The method for producing an optical component according to claim 1, wherein the ink is an antiglare-imparting composition containing a polymerizable organic compound, an organic solvent, and an additive.   The method for producing an optical component according to claim 3, wherein the polymerizable organic compound is an ultraviolet curable resin, and the dots are cured by irradiating the dots with ultraviolet rays in the dot forming step.   The manufacturing method of the optical component as described in any one of Claims 1-4 which forms the low-refractive-index layer which consists of a composition for low-refractive-index layer formation on the said glare-proof layer using an inkjet apparatus.   The method for producing an optical component according to claim 5, wherein the composition for forming a low refractive index layer includes a polymerizable organic compound, low refractive fine particles, an organic solvent, and an additive.   The method for producing an optical component according to claim 6, wherein the polymerizable organic compound is an ultraviolet curable resin.   A high refractive index layer made of a composition for forming a high refractive index layer is formed on the antiglare layer using an ink jet device, and a low refractive index layer is formed on the high refractive index layer using an ink jet device. The manufacturing method of the optical component as described in any one of Claims 1-4 which forms the low-refractive-index layer which consists of a composition for formation.   The high refractive index layer forming composition includes a polymerizable organic compound, high refractive fine particles, an organic solvent, and an additive, and the low refractive index layer forming composition includes a polymerizable organic compound, a low refractive fine particle, and an organic solvent. The manufacturing method of the optical component of Claim 8 containing an additive.   The method for producing an optical component according to claim 9, wherein the polymerizable organic compound of the high refractive index layer forming composition and the polymerizable organic compound of the high refractive index layer forming composition are ultraviolet curable resins. A substrate and an antiglare layer formed on the substrate;
The antiglare layer is composed of a plurality of dots made of the same antiglare property-imparting composition that are randomly arranged on the substrate, and at least some of these dots are An optical component in which the ridgelines overlap and the vertices overlap each other in an independent state in the cross section.   The optical component according to claim 11, wherein a coverage of the base material by the antiglare layer is 35% or more and 100% or less.   The optical component according to claim 11, further comprising a low refractive index layer formed on the antiglare layer.   The optical component according to claim 11 or 12, further comprising a high refractive index layer formed on the antiglare layer and a low refractive index layer formed on the high refractive index layer.

Images