JP2015064530A - Precise dot-pattern print film, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a precise dot-pattern print film and a manufacturing method thereof, capable of performing highly precise short-step patterning on a large area using gravure printing method inexpensively.SOLUTION: A precise dot-pattern print film 1 includes: a transparent base material 4 with flexibility; a foundation layer 3 formed on the transparent base material 4; and a dot pattern 2 formed of a plurality of dots 2a, provided on the foundation layer 3. A diameter of the dot 2a is 50 μm or less so as to have excellent pattern precision. The precise dot-pattern print film 1 is used as a black matrix, thereby providing the black matrix preventing stray light and having a high contrast. Further, the black matrix is used for a light diffusion film, thereby providing the light diffusion film having wide viewing angle characteristics and the high contrast.

Description

  The present invention relates to a precision dot pattern printing film and a method for producing the same.

  With the development of flat displays in recent years, that is, with an increase in the number of pixels, high-precision patterning is required for optical members to be used. Furthermore, it has become essential for optical members that have been subjected to such patterning processing to be capable of being produced in a large area and at a low cost so as to cope with an increase in the size of the display.

  For example, in a display device such as a liquid crystal display device or a rear projection display device, a light diffusion film is generally used as an optical member that diffuses a collimated light beam and ensures a wide viewing angle characteristic. This light diffusing film is formed by forming, for example, a light transmissive layer having a substantially V-shaped cross-section or a light transmissive layer made of transparent beads on a black matrix serving as a light absorption layer, and thereby diffusing all light due to a difference in refractive index. Reflection is used to improve viewing angle characteristics, and black matrix prevents stray light and improves contrast.

  By the way, when manufacturing a light diffusion film as described above, it is necessary to form a black matrix as a precise and fine dot pattern on a transparent film. As a method for forming such a black matrix, a photolithography method using a black photosensitive resin (see, for example, Patent Document 1), an offset printing method, a screen printing method, a gravure printing method on a transparent film, and the like. There is a method of directly printing a desired dot pattern using (see, for example, Patent Documents 2 and 3).

Japanese Patent Publication No. 6-40243 JP 2004-054771 A JP 2005-1117023 A

  However, in the photolithography method, it is difficult to increase the size of equipment including the exposure apparatus. For this reason, it is not preferable as a patterning formation method in a large area. In addition, there are problems in productivity and manufacturing cost due to process complexity and equipment costs.

  In the offset printing method and the screen printing method, the basic printing method is sheet-fed printing. For this reason, it is not suitable as a printing method for a large area and it is difficult to say that the production efficiency is sufficiently high. Further, in the offset printing method, it is difficult to suppress ink bleeding or crushing that occurs during transfer from the blanket. Further, in the screen printing method, the screen plate is easily deformed, and the screen printing method itself is essentially a thick film printing method. For this reason, both printing methods have a problem in that printing accuracy is limited, and patterning with higher accuracy is difficult.

  On the other hand, the gravure printing method has an advantage that it is superior to the offset printing method and the screen printing method in terms of production efficiency and manufacturing cost because a seamless pattern can be printed in a large area by roll-to-roll. However, in the conventional gravure printing method, as in the offset printing method, the printed pattern becomes larger than the design pattern due to bleeding of ink during printing. For this reason, there is a problem that it is difficult to print a pattern with high accuracy, particularly when printing a very small dot shape with a diameter of several tens of μm or less. Further, when the viscosity of the ink to be used is increased and bleeding is suppressed, there is a problem that the shape to be transferred cannot be obtained as designed because the ink enters the gravure plate.

  The present invention has been made in order to solve the above-described problems, and is a precision dot pattern printing film in which extremely small dots having a desired function are formed, and such a precision dot pattern printing film is a short process. Furthermore, it aims at providing the manufacturing method of the precision dot pattern printing film which can be manufactured with high precision.

  Here, the present inventors have previously proposed a transparent substrate with an electromagnetic wave shielding film and a method for producing the same, which have excellent transparency, can be patterned with high accuracy in a short manufacturing process, and at a low cost. (Refer to “Japanese Unexamined Patent Application Publication No. 2008-300724”.) This electromagnetic wave shielding film is obtained by laminating an electromagnetic wave shielding layer having a base layer and a mesh pattern on one main surface of a flexible transparent substrate. The electromagnetic wave shielding layer is composed of a catalyst ink layer formed by a gravure printing method and a metal layer formed by electroless plating on the catalyst ink layer.

  Therefore, the present inventors have intensively studied to apply the above-described electromagnetic shielding film manufacturing method as a manufacturing method of a precision dot pattern printing film for forming a black matrix that solves the above-described problems. As a result, similar to the above electromagnetic wave shielding film, after forming a base layer on a flexible transparent substrate such as a resin film, the desired performance as a black matrix is exhibited on the base layer, and further thixotropic properties It has been found that by printing a dot-shaped pattern using a controlled ink, it is possible to print a highly accurate pattern over a large area in a short process and at a low cost, and the present invention has been completed.

  That is, the precision dot pattern printing film of the present invention comprises a transparent base material showing flexibility, a base layer formed on the transparent base material, and a dot pattern formed by a plurality of dots on the base layer. A precision dot pattern printing film provided, wherein a dot diameter is 50 μm or less.

In the precision dot pattern printing film, the dot diameter is preferably 15 μm or less.
In the precision dot pattern printing film, the dot has a light shielding property, and the dot having the light shielding property has an optical density of 2 or more in a visible light region having a wavelength of 380 nm to 780 nm when the film thickness is 1 μm. It is preferable that

  The method for producing a precision dot pattern printing film of the present invention includes a transparent base material exhibiting flexibility, a base layer formed on the transparent base material, a dot pattern formed by a plurality of dots on the base layer, and A method for producing a precision dot pattern printing film comprising: a step of forming a base layer on a transparent substrate showing flexibility; and a step of forming a dot pattern consisting of a plurality of dots on the base layer; And the step of forming the dot pattern comprises two blades of ink for forming dots on a gravure printing cylinder on which a pattern groove having a shape corresponding to a plurality of dots is formed. And a step of transferring the ink applied on the plate cylinder to a base layer formed on the transparent substrate, and the transfer of the ink was performed by applying the ink to the base layer. Crimp to the plate cylinder Performed by, characterized in that the transfer time to the time of the transfer and the plate cylinder and the base layer away from contact with 0.5 seconds or more and 10 seconds or less.

  In the method for producing a precision dot pattern printing film, the ink exhibits thixotropic properties, and the viscosity measured by a rotational viscometer is 100 Pa · s or higher when the rotational speed is 0.5 rpm or lower, and the rotational speed is 10 rpm. When it is as described above, it is preferably 50 Pa · s or less.

  The black matrix of the present invention is characterized by using the precision dot pattern printing film of the present invention.

  According to the precision dot pattern printing film of the present invention, a transparent base material showing flexibility, a base layer formed on the transparent base material, and a dot pattern formed by a plurality of dots on the base layer It is a precision dot pattern printing film provided, and since the dot diameter is 50 μm or less, the pattern accuracy is excellent. Therefore, by using this precision dot pattern printing film as a black matrix, stray light can be prevented and a black matrix having high contrast can be obtained. Furthermore, by using the black matrix for a light diffusion film, a light diffusion film having a wide viewing angle characteristic and high contrast can be obtained.

  According to the method for producing a precision dot pattern printing film of the present invention, a step of forming a base layer on a transparent substrate showing flexibility, a step of forming a dot pattern consisting of a plurality of dots on the base layer, In addition, the step of forming a dot pattern comprises using two blades of ink for forming dots on a gravure printing cylinder on which a pattern groove having a shape corresponding to a plurality of dots is formed. And the step of transferring the ink applied on the plate cylinder to the underlayer formed on the transparent substrate, and the transfer of the ink includes a plate on which the ink is applied to the underlayer Since the transfer time from contact between the plate cylinder and the underlying layer to separation is set to 0.5 seconds or more and 10 seconds or less during the transfer, an extremely small dot pattern is formed. Large film And it can be manufactured with high precision. In particular, by using a gravure printing method capable of continuously printing on a long film, a precise dot pattern consisting of a plurality of dots having a diameter of 50 μm or less, particularly preferably a diameter of 15 μm or less, is formed on the long film. Since it can be formed continuously, it is possible to manufacture with a short process and low cost, and it is possible to improve production efficiency and manufacturing cost.

  According to the black matrix of the present invention, since the precision dot pattern printing film is used, stray light can be prevented and a black matrix having high contrast can be obtained. Furthermore, by using the black matrix for a light diffusion film, a light diffusion film having a wide viewing angle characteristic and high contrast can be obtained.

It is a top view which shows typically the structure of the precision dot pattern printing film which concerns on one Embodiment of this invention. It is sectional drawing which shows typically the structure of the precision dot pattern printing film shown in FIG. It is a side view which shows typically the gravure printing apparatus used at the formation process of the dot pattern of the precision dot pattern printing film shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following embodiments are specifically described for better understanding of the gist of the invention, and do not limit the present invention unless otherwise specified. Further, in the drawings used in the following description, in order to make the features easy to understand, the feature portions may be schematically shown, or in order to make each component easy to see, the dimensions may be shown with different scales. .

[Precision dot pattern printing film]
First, a precision dot pattern printing film (hereinafter sometimes referred to as “dot printing film”) 1 shown in FIGS. 1 and 2 will be described as an embodiment of the present invention.
FIG. 1 is a plan view schematically showing the configuration of the dot printing film 1. FIG. 2 is a cross-sectional view schematically showing the configuration of the dot printing film 1 shown in FIG.

  As shown in FIGS. 1 and 2, the dot printing film 1 is a transparent film in which a light-transmitting base layer 3 is formed on the upper surface of a transparent base 4 having flexibility such as polyethylene terephthalate (PET). 5 and a dot pattern 2 formed by a plurality of dots 2a on the upper surface of the base layer 3.

  In the present embodiment, in order to simplify the description of the dot pattern 2, the planar shape of the dots 2a shown in FIGS. 1 and 2 is circular and the arrangement of the dots 2a is also a regular arrangement pattern. The number 2 is not limited to this. For example, as the planar shape of the dot 2a, an arbitrary shape such as an ellipse or a polygon can be selected. Thus, when the planar shape of the dot 2a is other than a circle, the planar shape of the dot is approximated by a circle, and the diameter of the approximate circle is taken as the diameter of the todd 2a. Also, the arrangement pattern of the dots 2a may be randomly arranged.

  The dot printing film 1 of this embodiment is suitably used as a black matrix used for a light diffusion film. When this dot printing film 1 is used as a black matrix, the dot pattern 2 is formed by the light-shielding dots 2a, and the obtained dot pattern 2 becomes a black matrix. In the present embodiment, the case where the dots 2a have light shielding properties will be described. However, if the dot printing film 1 is used for purposes other than the black matrix, it is essential that the dots 2a have light shielding properties. It is not a thing.

  When the dot printing film 1 is used as a black matrix, the diameter of the dots 2a is preferably 5 μm or more and 50 μm or less, more preferably 7 μm or more and 30 μm or less, and further preferably 10 μm or more and 15 μm or less. .

  When the diameter of the dot 2a is less than 5 μm, the light reflection / scattering effect is lowered, and thus it is difficult to obtain the effect of improving the viewing angle in the light diffusion film. In addition, when the dot 2a is formed by using a gravure printing method described later, if the diameter of the dot 2a is 5 μm or more, the dot 2a having a good shape and good shape can be obtained. On the other hand, when the diameter of the dot 2a exceeds 50 μm, the transmitted light amount is reduced, and a rough feeling of the image due to the dot 2a is generated.

  In particular, when the dot printing film 1 of the present embodiment is used as a black matrix, the diameter of the dots 2a is preferably 15 μm or less. By setting the diameter of the dots 2a to 15 μm or less, in the display device formed using the black matrix, it is possible to obtain a display device having high brightness and contrast, excellent visibility, and wide viewing angle characteristics. Moreover, in the dot print film of this embodiment, even when the gravure printing method suitable for preparation of a long print film is used, the dot 2a 15 micrometers or less in diameter can be formed in a favorable shape. Therefore, it is suitable also as the dot printing film 1 which has a long and a dot of the size of 15 micrometers or less.

  The underlayer 3 is composed of a composite material containing oxide fine particles and an organic polymer. Examples of the oxide fine particles include metal oxides such as alumina, titania and zirconia, and inorganic oxide fine particles such as silica. Moreover, you may mix and use these 2 or more types.

  The organic polymer may be any resin that has an affinity for the ink that forms the dots 2a described later, such as cellulose derivatives such as ethyl cellulose and propyl cellulose, polyvinyl butyral, acrylic resin, polyurethane resin, and rosin ester resin. Etc. Moreover, you may use these in mixture of 2 or more types.

  In particular, if a resin having flexibility such as polyurethane resin is used, the underlayer 3 has flexibility. As a result, the ink 9 for forming dots is transferred to the plate cylinder in the gravure printing apparatus shown in FIG. When transferring from 6 to the underlayer 3, the underlayer 3 follows the pattern groove 7 of the plate cylinder 6 and is pressed into the pattern groove 7. .

  The ratio (O / R1) between these oxide fine particles (O) and the organic polymer (R1) is preferably 90/10 to 10/90, more preferably 60/40 to 40/60. It is. When the ratio of the oxide fine particles (O) is higher than the above range, the adhesion strength with the transparent substrate 4 becomes weak, the transmittance of the obtained dot print film 1 is lowered, and the haze value is increased. On the other hand, if the ratio is lower than the above range, the adhesion strength with the transparent substrate 4 becomes weak, and the effect as a receiving layer when forming the dots 2a by the gravure printing method is small, and the printed dots 2a There is a risk of dripping and bleeding.

  Moreover, it is preferable that the thickness of the base layer 3 is 0.5 micrometer-10 micrometers, More preferably, they are 1 micrometer-3 micrometers. When the thickness of the underlayer 3 is less than 0.5 μm, the effect as a receiving layer when forming the dots 2a by the gravure printing method described later is reduced. On the other hand, when the thickness of the foundation layer 3 exceeds 10 μm, there is a possibility that cracks or the like may occur in the pattern of the dots 2a when the dots 2a are formed by the gravure printing method described later.

  The plurality of dots 2a forming the dot pattern 2 is composed of a composite material containing a pigment that exhibits light absorption and an organic polymer. The pigment exhibiting light absorption may be any pigment that can absorb light in the visible light wavelength range of 380 nm to 780 nm, and examples thereof include metal oxides such as carbon black, titanium black, and iron oxide. be able to. Moreover, you may mix and use these 2 or more types. Further, black metal fine particles such as silver tin alloy fine particles can be used.

  The organic polymer only needs to be suitable for gravure printing, and examples thereof include cellulose resins, rosin ester resins, acrylic resins, polyvinyl butyrate resins, and polyurethane resins. Moreover, you may use these in mixture of 2 or more types. Cellulosic resins and the like are more preferable because they can easily control the thixotropy of the ink 9, which will be described later, and also improve the transferability during printing.

  The ratio (M / R2) between the pigment (M) exhibiting light absorption and the organic polymer (R2) is preferably 30/70 to 80/20, more preferably 40/60 to 70/30. When the ratio of the pigment (M) exhibiting light absorption is lower than the above range, the light shielding property of the dots 2a becomes insufficient, leading to a decrease in contrast. On the other hand, if the ratio of the pigment (M) exhibiting light absorption is higher than the above range, in the formation process of the dot pattern 2 described later, the printability of the dots 2a is deteriorated, and the film curing by the organic polymer is insufficient. Sufficient adhesion of the dots 2a to the underlying layer 3 cannot be obtained.

  When the various conditions of the dot 2a satisfy the above range, the dot 2a can have an optical density (OD value) of 2 or more in a visible light region having a wavelength of 380 nm to 780 nm at a thickness of 1 μm. Thereby, the dot printing film 1 in which the dot pattern 2 is formed can be suitably used as a black matrix used for the light diffusion film.

  In addition, the thickness (height) of the dot 2a is preferably 0.5 μm to 10 μm, more preferably 1 μm to 5 μm. When the thickness of the dot 2a is less than 0.5 μm, it is necessary to increase the ratio of the pigment exhibiting light absorption in order to obtain a necessary light shielding property. As a result, the printability of the dots 2a is deteriorated, film hardening by the organic polymer is insufficient, and sufficient adhesion of the dots 2a to the underlayer 3 cannot be obtained. On the other hand, when the thickness of the dot 2a exceeds 10 μm, the dot 2a may be cracked. In addition, when the dot printing film 1 is used as a black matrix, when an RGB film is applied and formed on the surface on which the dot pattern 2 is formed, a rising step occurs in the portion where the dot 2a exists, so that There is a risk of leakage.

  The thickness (height) of the dot 2a is the thickness of the flat portion at the center of the upper surface of the dot 2a. However, when the diameter of the dot 2a is small and the upper surface is not flat, the average thickness is taken as the value.

  In addition, as a pigment which shows light absorptivity, you may select what can absorb not only visible light area | region with a wavelength of 380 nm-780 nm but ultraviolet light, such as wavelength 365 nm (Hg-i line) which is an ultraviolet light area | region. . Thereby, the dot 2a has a light shielding property not only for visible light but also for ultraviolet light. By selecting such a pigment, the dot 2a can have an optical density (OD value) of 2 or more in a visible light region having a wavelength of 380 nm to 780 nm and ultraviolet light having a wavelength of 365 nm at a thickness of 1 μm.

  Further, by using a pigment exhibiting such light absorption, by producing a pattern-forming film in which various light-shielding patterns are formed on a transparent substrate by the same method as that for producing the dot printing film 1, Since the light-shielding pattern shields ultraviolet light, the pattern forming film can be used not only for visible light shielding such as a black matrix but also as a photomask for pattern formation of an ultraviolet photosensitive resin. The carbon black, titanium black, iron oxide and the like have light absorption characteristics with respect to ultraviolet light.

  Moreover, you may add ultraviolet-ray-cutting materials, such as UV absorber, to a light-shielding pattern as needed. Thereby, the light-shielding property in the ultraviolet region in the light-shielding pattern can be further enhanced, and the performance as a photomask application can be further enhanced.

[Preparation method of precision dot pattern printing film]
Next, a method for producing the dot printing film 1 will be described.
The manufacturing method of the dot printing film 1 includes a step of forming the base layer 3 on the transparent substrate 4 and a step of forming the dot pattern 2 composed of a plurality of dots 2 a on the base layer 3.

"Formation process of underlayer"
The formation process of the foundation layer 3 is a process of applying a coating composition for forming the foundation layer 3 to form the foundation layer 3 on the upper surface of the transparent base material 4 having flexibility such as polyethylene terephthalate (PET), and then drying it. It is. Thereby, the foundation layer 3 is formed on the upper surface of the transparent substrate 4. As the coating method, for example, a gravure printing method, a bar coat printing method, an offset printing method, or the like can be used, and among these, it is preferable to use micro gravure printing.

  The thickness of the underlayer 3 is preferably 0.5 μm to 10 μm, more preferably 1 μm to 3 μm. When the thickness of the underlayer 3 is less than 0.5 μm, the effect as a receiving layer when forming the dots 2a by the gravure printing method described later is reduced. On the other hand, when the thickness of the foundation layer 3 exceeds 10 μm, there is a possibility that cracks or the like may occur in the pattern of the dots 2a when the dots 2a are formed by the gravure printing method described later.

As the paint for forming the underlayer, a paint containing an organic solvent is preferably used in addition to the oxide fine particles and the organic polymer that are the constituent components of the above-described underlayer 3.
Examples of the oxide fine particles include metal oxides such as alumina, titania and zirconia, and inorganic oxide fine particles such as silica. Moreover, you may mix and use these 2 or more types.

  The content of the oxide fine particles in the underlayer-forming coating material is preferably 0.2% by mass to 15% by mass, and more preferably 1% by mass to 8% by mass. When the content of the oxide fine particles is less than 0.2% by mass, the thickness of the underlayer 3 is reduced, and the effect as a receiving layer when forming the dots 2a is reduced. On the other hand, when the content of the oxide fine particles exceeds 15% by mass, the thickness of the underlayer 3 is increased, and there is a possibility that the printed dot 2a pattern is cracked.

The organic polymer may be any resin that has an affinity for the ink 9 that forms the dots 2 in the next step. For example, cellulose derivatives such as ethyl cellulose and propyl cellulose, polyvinyl butyral, acrylic resin, polyurethane resin, rosin An ester resin etc. can be mentioned. Two or more of these may be mixed.
In particular, if a flexible resin such as polyurethane resin is used, the base layer itself has flexibility. As a result, the ink 9 for dot formation is transferred from the body plate onto the base layer by the gravure printing method. In this case, it is preferable that the underlying layer follows the pattern groove of the body plate and comes into contact therewith and is pressed into the pattern groove, thereby improving the transferability.

  The content of the organic polymer in the undercoat layer-forming coating material is preferably 0.2% by mass to 15% by mass, and more preferably 1% by mass to 8% by mass. If the content of the organic polymer is less than 0.2% by mass, the thickness of the base layer 3 is reduced, and the effect as a receiving layer when forming the dots 2a is reduced. If it exceeds 50%, the thickness of the underlayer 3 is increased, and there is a risk that cracks or the like may occur in the printed dot 2a pattern.

As the organic solvent, it is sufficient that the oxide fine particles can be dispersed, the organic polymer can be dissolved, and wettability with respect to the transparent substrate 4 is sufficient. Examples of such organic solvents include aromatic hydrocarbons such as toluene and xylene, cyclized aliphatic hydrocarbons such as cyclohexanone, ketones such as methyl ethyl ketone (MEK), and alcohols such as 2-propanol. Can do. Moreover, you may mix and use these 2 or more types.
In addition, about dispersion | distribution of oxide microparticles | fine-particles, you may use a surface treating agent, a dispersing agent, etc. together.

"Dot pattern formation process"
The formation process of the dot pattern 2 is a process of applying the ink 9 by gravure printing to form the dots 2a on the upper surface of the base layer 3 and then drying it. Thereby, a dot pattern 2 composed of a plurality of dots 2 a is formed on the upper surface of the underlayer 3.

  In forming the dots 2a, the ink 9 containing an organic solvent is used in addition to the light-absorbing pigment and the organic polymer, which are constituents of the dots 2a. The ink 9 preferably has thixotropic properties suitable for gravure printing.

Any pigment capable of absorbing light having a wavelength in the visible light range of 380 nm to 780 nm may be used. Examples thereof include metal oxides such as carbon black, titanium black, and iron oxide. Two or more of these may be mixed. Further, black metal fine particles such as silver tin alloy fine particles can be used.
Furthermore, if a pigment capable of absorbing ultraviolet light such as a wavelength of 365 nm (Hg-i line) in the ultraviolet light region as well as a visible light region having a wavelength of 380 nm to 780 nm is selected as the pigment exhibiting light absorption, the dot 2a , Not only visible light but also ultraviolet light shielding property can be imparted.

  The content of the pigment exhibiting light absorption in the ink 9 is preferably 1% by mass to 25% by mass, and more preferably 5% by mass to 20% by mass. When the content of the pigment exhibiting light absorption is less than 1% by mass, the light shielding property of the dots 2a becomes insufficient, leading to a decrease in contrast. On the other hand, when the content of the pigment exhibiting light absorption exceeds 25% by mass, there is no problem with respect to the light shielding property and contrast of the dots 2a, but the printability is deteriorated.

  The organic polymer only needs to be suitable for gravure printing, and examples thereof include cellulose resins, rosin ester resins, acrylic resins, polyvinyl butyrate resins, and polyurethane resins. Two or more of these may be mixed. Among these resins, a cellulose-based resin or the like is more preferable because it easily controls the thixotropy of the ink 9 and further improves transferability during printing.

  The content of the organic polymer in the ink 9 is preferably 5% by mass to 25% by mass, and more preferably 10% by mass to 20% by mass. When the content of the organic polymer is less than 5% by mass, the viscosity of the ink 9 is low, so that stringing or the like occurs during gravure printing and a good printing state cannot be obtained. On the other hand, when the content of the organic polymer exceeds 25% by mass, the viscosity of the ink 9 becomes too high, and the ink 9 is not sufficiently put on the gravure plate, so that it is difficult to obtain a print pattern as designed.

  In addition, it is preferable that the ratio (M / R2) of the pigment (M) which shows the light absorptivity in the ink 9, and organic polymer (R2) is 30 / 70-80 / 20 by mass ratio, More preferably Is 40/60 to 70/30. When the ratio of the pigment (M) exhibiting light absorption is lower than the above range, the light shielding property of the formed dots 2a becomes insufficient, leading to a decrease in contrast. On the other hand, when the ratio of the pigment (M) exhibiting light absorption is higher than the above range, not only the printability of the dots 2a is deteriorated, but also the film hardening by the organic polymer is insufficient in the printed dots 2a. Sufficient adhesion to the formation 3 cannot be obtained.

Any organic solvent may be used as long as it can disperse the light-absorbing pigment, can dissolve the organic polymer, and is suitable for gravure printing. Examples of such an organic solvent include toluene, methyl ethyl ketone, methyl isobutyl ketone, butyl acetate, cyclohexanone, butyl carbitol, butyl carbitol acetate, α-terpineol, and the like. Moreover, you may mix and use these 2 or more types.
In addition, about dispersion | distribution of the pigment which shows a light absorptivity, you may use a surface treating agent, a dispersing agent, etc. together.

  Regarding the thixotropy of the ink 9, the viscosity measured by a Brookfield (BF) rotational viscometer is 100 Pa · s or higher when the rotational speed is 0.5 rpm or lower, and the rotational speed is 10 rpm or higher. It is preferably 50 Pa · s or less. More preferably, it is 200 Pa · s or more when the rotation speed is 0.5 rpm or less, and 25 Pa · s or less when the rotation speed is 10 rpm or more.

  If the viscosity of the ink 9 is less than 100 Pa · s when the rotation speed is 0.5 rpm or less, dripping / bleeding of the ink 9 cannot be suppressed during gravure printing, and the size of the dot 2a after transfer becomes larger than the design. In addition to this, problems such as stringing occur and a good printed appearance cannot be obtained. On the other hand, if the viscosity of the ink 9 exceeds 50 Pa · s when the rotational speed is 10 rpm or more, the supply of the ink 9 on the gravure plate becomes insufficient when printing the very small dot 2a, and printing as designed. The shape cannot be obtained.

  By controlling the thixotropy of the ink 9 within the above range, when the dot pattern 2 is formed by the gravure printing apparatus shown in FIG. 3 to be described later, the ink is contacted between the rotating plate cylinder 6 and the blades 10 and 11. Since the shearing force is applied to 9 and the viscosity of the ink 9 is lowered, the supply of the ink 9 to the pattern groove 7 and the removal of the excess ink 9 other than the pattern groove 7 can be sufficiently performed. On the other hand, since the viscosity of the ink 9 is increased under a low shearing force, there is no problem such as stringing when the ink 9 in the pattern groove 7 is transferred to the base layer 3, that is, when printing (formation) of the dots 2a. A good printed appearance is obtained. In this way, by controlling the thixotropy of the ink 9 within the above range, it is possible to pattern-print extremely small dots 2a having a diameter of 15 μm or less.

The ink 9 can be added with various components as needed within a range that does not impair the thixotropy.
For example, the light shielding property in the ultraviolet region of the dot pattern 2 can be improved by adding an ultraviolet cut material such as a UV absorber. According to the pattern forming film in which various light-shielding patterns are formed on a transparent substrate using such an ink 9, the light shielding performance in the ultraviolet region can be further improved. When used as a photomask for forming a resin pattern, the light-shielding performance can be further improved, and it can be suitably used as a photomask.

  Further, by adding a dispersant or a surface treatment agent, it is possible to improve the dispersibility of the pigment exhibiting light absorptivity in the organic solvent, and it is possible to form the dots 2a that are more uniform and have high light shielding properties.

  Further, inorganic fine particles or organic fine particles can be added to the ink 9 in order to adjust thixotropy. Examples of the inorganic fine particles include metal oxide fine particles such as silica, alumina, zinc oxide, zirconia, and titania. Examples of the organic fine particles include acrylic resin fine particles. Two or more kinds of these fine particles may be mixed and used. The content of these fine particles contained in the ink 9 varies depending on various conditions such as the type and amount of other components in addition to the components and particle diameters of the fine particles themselves, but cannot be generally stated, but is generally 30% by mass or less. It is preferable.

"Gravure printing device"
Here, in the formation of the dot pattern 2, for example, a gravure printing apparatus as shown in FIG. 3 can be suitably used. This gravure printing apparatus applies a plate cylinder 6 in which pattern grooves 7 having a shape corresponding to a plurality of dots 2 a are formed on a cylindrical surface, and ink 9 for forming dots 2 a on the surface of the plate cylinder 6. The first blade 10 and the second blade 10 that fill the pattern groove 7 with the ink 8 applied to the surface of the dispenser 8 and the plate cylinder 6 and remove excess ink 9 other than the ink 9 filled in the pattern groove 7. While the transparent film 5 having the base layer 3 formed on one side of the transparent base material 4 is sandwiched between the blade 11 and the plate cylinder 6, the plate cylinder is placed on the surface of the transparent film 5 on the base layer 3 side for a predetermined time. 6 is schematically provided with a backup roll 12 for pressing the surface of 6 and guide rolls 13a and 13b for guiding the transparent film 5 on which the dots 2a are formed.

  In the formation of the dot pattern 2 using this gravure printing apparatus, the surface of the transparent film 5 on which the base layer 3 is formed is brought into contact with and pressed against the surface of the plate cylinder 6 for a predetermined time, whereby the ink in the pattern groove 7 is obtained. 9 is transferred onto the underlayer 3. Therefore, the pressing time, that is, the time from when the plate cylinder 6 comes into contact with the underlayer 3 of the transparent film 5 to when the ink 9 is transferred is taken as the transfer time.

  In the step of forming the dot pattern 2 using the gravure printing apparatus shown in FIG. 3, first, for this transfer, the positions of the backup roll 12 and the guide rolls 13a and 13b are adjusted, and a certain pressing time according to the printing speed. That is, a transfer time is obtained.

  The transfer time is preferably 0.5 seconds or more and 10 seconds or less, more preferably 1 second or more and 5 seconds or less. When the transfer time is less than 0.5 seconds, the organic solvent is not sufficiently absorbed onto the underlayer 3, the viscosity of the ink 9 filled in the pattern groove 7 of the plate cylinder 6 does not increase, and stringing is performed. A defect occurs, and a good dot pattern 2 shape cannot be obtained. On the other hand, if the transfer time exceeds 10 seconds, the organic solvent is excessively absorbed in the underlayer 3 and the viscosity of the ink 9 becomes too high, so that the transfer to the underlayer 3 is deteriorated.

Next, the contact angles of the first blade 10 and the second blade 11 with the surface of the plate cylinder 10 are adjusted.
Here, the angle angle θ1 formed by the first blade 10 with respect to the tangent line a of the plate cylinder 6 at the contact point between the first blade 10 and the plate cylinder 6 is an acute angle of 45 ° or more and 90 ° or less. preferable. When the angle θ1 is less than 45 ° or exceeds 90 °, the ink 9 enters the pattern groove 7 insufficiently.

  The angle θ2 formed by the second blade 11 with respect to the tangent line b of the plate cylinder 6 at the contact point between the second blade 11 and the plate cylinder 6 is preferably 100 ° or more. When the angle θ2 is less than 100 °, the depth of the pattern groove 7 becomes shallow when printing the minimal dot pattern 2, so that a part of the ink 9 filled in the pattern groove 7 is part of the second blade 11. Therefore, the desired dot pattern 2 shape cannot be obtained. In addition to this, the scraped out ink 9 adheres to the surface of the plate cylinder 6, and as a result, the ink 9 is transferred to a region other than the region where the dot pattern 2 of the transparent film 5 is formed. As a result, a good dot pattern 2 cannot be formed.

  By setting the angles θ1 and θ2 of the first blade 10 and the second blade 11 within the above range, the ink 9 applied to the surface of the plate cylinder 6 is surely filled into the pattern groove 7 and the pattern groove Excess ink 9 other than the ink 9 filled in 7 can be reliably removed. Thereby, the designed dot pattern 2 can be printed on the underlayer 3 with high accuracy.

Printing is performed after adjusting the transfer time of the transparent film 5 and the angles θ1 and θ2 of the first blade 10 and the second blade 11.
First, the ink 9 is applied to the surface of the plate cylinder 6 by the dispenser 8, and then the ink 9 is filled in the pattern groove 7 by the first blade 10 and the second blade 11 and applied to the surface of the plate cylinder 6. The excess ink 9 is removed.
Next, while sandwiching the transparent film 5 between the plate cylinder 6 and the backup roll 12, the plate cylinder is formed on the surface of the base layer 3 of the transparent film 5 so that the transfer time is 0.5 seconds or more and 10 seconds or less. Then, the surface of the plate cylinder 6 is separated from the surface of the underlayer 3 of the transparent film 5. As a result, the ink 9 is transferred (printed) onto the surface of the base layer 3 of the transparent film 5.

  The ink 9 transferred to the surface of the base layer 3 of the transparent film 5 is cured by removing the solvent by a subsequent drying process using a dryer or the like (not shown). As a result, a dot pattern 2 composed of a plurality of dots 2 a is formed on the surface of the base layer 3 of the transparent film 5.

In addition, after removing the solvent, the degree of curing of the ink 9 (dot 2a) may be increased by further applying heat, light, or the like to advance polymerization of the organic polymer.
The dot printing film 1 can be obtained through the above steps.

  As described above, according to the manufacturing method of the present embodiment, by setting the various conditions of the pigment, the organic polymer, and the organic solvent that exhibit light absorption in the ink 9 for forming the dots 2a to values in the above range, The optical density (OD value) in the visible light region having a wavelength of 380 nm to 780 nm at a thickness of 1 μm of the obtained dot 2a can be 2 or more. Furthermore, the viscosity of the ink 9 is adjusted and the thixotropy of the ink 9 is adjusted as described above by setting the various conditions of the pigment, organic polymer, and organic solvent exhibiting light absorption in the ink 9 to values in the above range. By controlling, it is possible to form the minute dots 2a using the gravure printing apparatus. By these, the dot printing film which can be used suitably as a black matrix used for a light-diffusion film can be obtained.

  Furthermore, according to the manufacturing method of the present embodiment, the very small dots 2a having a diameter of 50 μm or less, in particular, a diameter of 15 μm or less, are continuously formed in a good shape on the long transparent film 5. Can do. Moreover, it is possible to manufacture the dot printing film 1 formed with such a small dot pattern 2 with a large area and high accuracy. In particular, by using a gravure printing method capable of continuously printing on the long transparent film 5, the long transparent film 5 has a diameter of 50 μm or less, particularly preferably a plurality of dots 2a having a diameter of 15 μm or less. Since the precise dot pattern 2 can be continuously formed, it is possible to manufacture with a short process and low cost, and it is possible to improve production efficiency and manufacturing cost. In the following embodiments, the case where dots have light shielding properties will be described. However, the dots need not necessarily have light shielding properties.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement. In the following embodiments, the case where dots have light shielding properties will be described. However, the dots need not necessarily have light shielding properties.

[Example 1]
"Preparation of coating for forming the underlayer and formation of the underlayer"
240 g of alumina powder and 28 g of a phosphoric acid ester dispersant were added to 1332 g of toluene and dispersed using a sand mill to prepare an alumina dispersion. Next, the above alumina dispersion, 552 g of cyclohexanone, and 1800 g of methyl ethyl ketone (MEK) are added to a solution obtained by dissolving 240 g of ethyl cellulose in 1808 g of toluene, and mixed with a homogenizer to prepare the coating material for forming the underlayer of Example 1. did.
Next, the coating material for forming the underlayer is applied on a transparent substrate made of polyethylene terephthalate (PET) having a thickness of 100 μm by microgravure printing, and then dried to form a film on the transparent substrate. A transparent film of Example 1 on which a 2 μm thick underlayer was formed was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, carbon black particles (specific surface area 140 m ² / g) are dispersed in ethanol using an alkylammonium salt-based dispersant, then solid-liquid separated and dried, so that surface treatment with the dispersant is performed. Carbon black particles were obtained.
Next, ethyl cellulose was dissolved in a solution prepared such that α-terpineol and butyl carbitol acetate were adjusted to a mass ratio of 2: 1, and then the carbon black particles subjected to the above surface treatment were added, and a three-roll mill was used. The ink for dot formation of Example 1 was prepared by mixing and dispersing. The mass ratio between the carbon black particles and ethyl cellulose was 30:70.

  Here, the viscosity characteristic of the ink is adjusted by adjusting the amount of the dispersant on the surface of the carbon black particles, that is, the amount of the alkyl ammonium salt-based dispersant added when the carbon black particles are surface-treated. The viscosity was adjusted to 100 Pa · s when the rotational speed was 0.5 rpm and 40 Pa · s when the rotational speed was 10 rpm.

  Next, in the gravure printing apparatus shown in FIG. 3, using a gravure plate in which a perfect circular pattern groove having a diameter of 15 μm is formed as a plate cylinder, a printing speed of 15 m / min is formed on the transparent film of Example 1 above. The dots were formed under the conditions of a transfer time of 1.5 seconds. The angles of the first blade and the second blade were set to 50 ° and 110 °, respectively.

The dots obtained in Example 1 had a perfect circle shape with a film thickness of 1.0 μm and a diameter of 15 μm, and no defects such as stringing or dot chipping occurred. Further, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 2.2 or more, the optical density at a wavelength of 365 nm is 2.2, and it was found that the dot has sufficient light shielding performance. .
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 2]
"Preparation of coating for forming the underlayer and formation of the underlayer"
In the same manner as in Example 1, a transparent film of Example 2 in which an underlayer having a thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, the mass ratio of the carbon black particles to ethyl cellulose is 45:55, and the viscosity characteristics of the ink are 200 Pa · s when the rotation speed is 0.5 rpm and the viscosity is 20 Pa when the rotation speed is 10 rpm. The ink for dot formation of Example 2 was produced in the same manner as Example 1 except that s was set.

  Next, in the gravure printing apparatus shown in FIG. 3, a gravure plate in which an elliptical pattern groove having a minor axis of 10 μm and a major axis of 20 μm is formed as a plate cylinder on the transparent film of Example 2 above. The dots were formed under the conditions of a printing speed of 15 m / min and a transfer time of 1.5 seconds. The angles of the first blade and the second blade were set to 50 ° and 110 °, respectively.

The dots obtained in Example 2 had an elliptical shape with a film thickness of 1.0 μm, a short axis of 10 μm, and a long axis of 20 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 3 or more, and the optical density at a wavelength of 365 nm is 3.1, which indicates that the dot has sufficient light shielding performance.
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 3]
"Preparation of coating for forming the underlayer and formation of the underlayer"
In the same manner as in Example 1, a transparent film of Example 3 in which an underlayer having a thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, the mass ratio of carbon black and ethyl cellulose is 60:40, and the viscosity characteristics of the ink are 250 Pa · s when the rotation speed is 0.5 rpm, and 15 Pa · when the rotation speed is 10 rpm. The dot forming ink of Example 3 was produced in the same manner as in Example 1 except that s was set.

  Next, in the gravure printing apparatus shown in FIG. 3, a gravure plate in which a perfect circular pattern groove having a diameter of 15 μm is formed as a plate cylinder, and a printing speed of 15 m / min is formed on the transparent film of Example 3 above. The dots were formed under the conditions of a transfer time of 1.5 seconds. The angles of the first blade and the second blade were set to 50 ° and 10 °, respectively.

The dots obtained in Example 3 had a perfect circle shape with a film thickness of 1.0 μm and a diameter of 15 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 4 or more, and the optical density at a wavelength of 365 nm is 4.1, which indicates that the dot has sufficient light shielding performance.
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 4]
"Preparation of coating for forming the underlayer and formation of the underlayer"
In the same manner as in Example 1, a transparent film of Example 4 in which an underlayer having a thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, carbon black particles (specific surface area 140 m ² / g) are dispersed in ethanol using an alkylammonium salt-based dispersant, then solid-liquid separated and dried, so that surface treatment with the dispersant is performed. Carbon black particles were obtained.
Next, after dissolving ethyl cellulose and an ultraviolet absorber (Pulsol 1789, manufactured by DSM Nutrition Japan Co., Ltd.) in a solution prepared by adjusting the weight ratio of α-terpineol and butyl carbitol acetate to 2: 1, The carbon black particles subjected to the above surface treatment were added and mixed and dispersed by a three roll mill to prepare the ink for dot formation of Example 4. The mass ratio of the carbon black particles to ethyl cellulose and the ultraviolet absorber was 45:40:15.

  Here, the viscosity of the ink is adjusted by adjusting the amount of the dispersant on the surface of the carbon black particles, that is, the amount of the alkyl ammonium salt-based dispersant added when the carbon black particles are surface-treated. The viscosity was 210 Pa · s when the rotational speed was 0.5 rpm, and 25 Pa · s when the rotational speed was 10 rpm.

  Next, in the gravure printing apparatus shown in FIG. 3, a gravure plate in which a perfect circular pattern groove having a diameter of 13 μm is formed as a plate cylinder, and a printing speed of 15 m / min is formed on the transparent film of Example 4 above. The dots were formed under the conditions of a transfer time of 1.5 seconds. The angles of the first blade and the second blade were set to 50 ° and 110 °, respectively.

The dots obtained in Example 4 had a perfect circle shape with a film thickness of 1.0 μm and a diameter of 13 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 3 or more, and the optical density at a wavelength of 365 nm is 3.7, which indicates that the dot has sufficient light shielding performance.
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 5]
"Preparation of coating for forming the underlayer and formation of the underlayer"
In the same manner as in Example 1, a transparent film of Example 5 in which an underlayer having a thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, dots were formed on the transparent film of Example 5 in the same manner as in Example 4 except that the printing speed in Example 4 was 20 m / min and the transfer time was 1.1 seconds.

The dots obtained in Example 5 had a perfect circle shape with a film thickness of 0.7 μm and a diameter of 13 μm, and no problems such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 2.2 or more, the optical density at a wavelength of 365 nm is 2.9, and it was found that the dot has sufficient light shielding performance. .
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 6]
"Preparation of coating for forming the underlayer and formation of the underlayer"
A base layer-forming coating material of Example 6 was produced in the same manner as in Example 1 except that the alumina powder of Example 1 was replaced with silica powder.
Next, the coating material for forming the underlayer is applied on a transparent substrate made of a PET film having a thickness of 100 μm by microgravure printing, and then dried to form a film having a thickness of 2 μm on the transparent substrate. A transparent film of Example 6 on which an underlayer was formed was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, dots were formed on the transparent film of Example 6 in the same manner as in Example 1 except that the transparent film of Example 6 was used.

The dots obtained in Example 6 had a perfect circular shape with a film thickness of 1.0 μm and a diameter of 15 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 2.1 or more, the optical density at a wavelength of 365 nm is 2.1, and it was found that the dot has sufficient light shielding performance. .
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 7]
"Preparation of coating for forming the underlayer and formation of the underlayer"
A base layer-forming coating material of Example 7 was produced in the same manner as in Example 1 except that the alumina powder of Example 1 was replaced with zirconia powder.
Next, the coating material for forming the underlayer is applied on a transparent substrate made of a PET film having a thickness of 100 μm by microgravure printing, and then dried to form a film having a thickness of 2 μm on the transparent substrate. A transparent film of Example 7 on which an underlayer was formed was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, dots were formed on the transparent film of Example 7 in the same manner as in Example 1 except that the transparent film of Example 7 was used.

The light-shielding dots obtained in Example 7 had a perfect circular shape with a film thickness of 1.0 μm and a diameter of 15 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 2.2 or more, the optical density at a wavelength of 365 nm is 2.1, and it was found that the dot has sufficient light shielding performance. .
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 8]
"Preparation of primer layer coating and primer layer"
In the same manner as in Example 1, a transparent film of Example 8 in which an underlayer having a film thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, carbon black particles (specific surface area 140 m ² / g) are dispersed in ethanol using an alkylammonium salt-based dispersant, then solid-liquid separated and dried, so that surface treatment with the dispersant is performed. Carbon black particles were obtained.
In addition, alumina particles were dispersed in ethanol using an alkylammonium salt-based dispersant, then solid-liquid separated and dried to obtain alumina particles that had been surface-treated with the dispersant.
Next, after dissolving ethyl cellulose in a solution prepared by adjusting the mass ratio of α-terpineol and butyl carbitol acetate to 2: 1, the carbon black particles subjected to the surface treatment and the alumina subjected to the surface treatment are used. Particles were added and mixed and dispersed by a three-roll mill to prepare the ink for dot formation of Example 8. The mass ratio of carbon black particles, alumina particles, and ethyl cellulose was 28: 2: 70.

  Here, the viscosity characteristics of the ink are adjusted by adjusting the amount of the dispersant on the surface of the carbon black particles and the surface of the alumina particles, that is, the amount of the alkylammonium salt dispersant added when the carbon black particles and the alumina particles are surface-treated. The viscosity measured by the BF rotational viscometer was 100 Pa · s when the rotational speed was 0.5 rpm, and 50 Pa · s when the rotational speed was 10 rpm.

  Next, in the gravure printing apparatus shown in FIG. 3, using a gravure plate in which a perfect circular pattern groove having a diameter of 15 μm is formed as a plate cylinder, a printing speed of 15 m / min is formed on the transparent film of Example 8 above. The dots were formed under the conditions of a transfer time of 1.5 seconds. The angles of the first blade and the second blade were set to 50 ° and 110 °, respectively.

The dots obtained in Example 8 had a perfect circular shape with a film thickness of 1.0 μm and a diameter of 15 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 2.2 or more, the optical density at a wavelength of 365 nm is 2.0, and it was found that the dot has sufficient light shielding performance. .
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 9]
"Preparation of coating for forming the underlayer and formation of the underlayer"
In the same manner as in Example 1, a transparent film of Example 9 in which an underlayer having a thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, a dot forming ink of Example 9 was produced in the same manner as in Example 8, except that the mass ratio of carbon black particles, alumina particles, and ethyl cellulose in Example 8 was set to 26:10:64. .

  Here, the viscosity characteristics of the ink are adjusted by adjusting the amount of the dispersant on the surface of the carbon black particles and the surface of the alumina particles, that is, the amount of the alkylammonium salt dispersant added when the carbon black particles and the alumina particles are surface-treated. The viscosity measured by the BF rotational viscometer was 150 Pa · s when the rotational speed was 0.5 rpm and 50 Pa · s when the rotational speed was 10 rpm.

  Next, in the gravure printing apparatus shown in FIG. 3, using a gravure plate in which a perfect circular pattern groove having a diameter of 15 μm is formed as a plate cylinder, a printing speed of 15 m / min is formed on the transparent film of Example 8 above. Then, dots were formed under the condition of a transfer time of 1.5 seconds. The angles of the first blade and the second blade were set to 50 ° and 110 °, respectively.

The dots obtained in Example 9 had a perfect circular shape with a film thickness of 1.0 μm and a diameter of 15 μm, and no defects such as stringing or dot chipping occurred. In addition, the optical density of the dot portion at a wavelength of 380 nm to 780 nm is 2 or more, and the optical density at a wavelength of 365 nm is 2.1, which indicates that the dot has sufficient light shielding performance.
From the above, it was confirmed that a good dot printing film having no problems in appearance and optical characteristics was obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Example 10]
"Preparation of primer layer coating and primer layer"
In the same manner as in Example 1, a transparent film of Example 10 in which an underlayer having a film thickness of 2 μm was formed on a transparent substrate made of a PET film having a thickness of 100 μm was produced.

"Preparation of ink for dot formation and preparation of dot printing film"
Next, by adjusting the addition amount of the alkylammonium salt-based dispersant, the viscosity characteristics of the ink are 400 Pa · s when the rotation speed is 0.5 rpm and the rotation speed is 10 rpm. The ink for dot formation of Example 10 was produced in the same manner as Example 2 except that the pressure was sometimes 150 Pa · s.
Next, dots were formed on the transparent film of Example 10 in the same manner as Example 2 except that the ink for forming dots of Example 10 was used.

The dots obtained in Example 10 had an elliptical shape with a film thickness of 1.0 μm, a short axis of 10 μm, and a long axis of 20 μm, and no stringing occurred. The dot portion had an optical density of 2.5 or more at a wavelength of 380 nm to 780 nm and an optical density of 2.2 at a wavelength of 365 nm, and the dot itself had sufficient light shielding performance. However, some of the dots have untransferred portions of ink (dots missing), and as a result, the appearance and optical characteristics of the dot printing film are lower than those of other examples.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Comparative Example 1]
Dots were formed on the transparent film in the same manner as in Example 2 except that a transparent substrate made of a PET film having a thickness of 100 μm and not forming a base layer was used as the transparent film.

The dots obtained in Comparative Example 1 were enlarged to a substantially circular shape with a diameter of 40 μm, and the film thickness could not be measured greatly. In addition, problems such as stringing occurred. For this reason, good film appearance and light shielding properties could not be obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

[Comparative Example 2]
Dots were formed on the transparent film in the same manner as in Example 2 except that the second blade 11 in the gravure printing apparatus shown in FIG. 3 was not used when forming the dots.

The dimensions of the dots obtained in Comparative Example 2 were as designed, but because the second blade was not used, it was possible to reliably remove excess ink other than the pattern grooves on the plate cylinder. There wasn't. As a result, since ink other than the dot pattern adhered to the obtained dot print film, a black rough feeling was generated, and a dot print film having good appearance and optical characteristics could not be obtained.
The above production conditions and the evaluation results of the obtained dot printing film are summarized and shown in Table 1A and Table 1B below.

  According to the precision dot pattern printing film of this embodiment, a transparent base material showing flexibility, a base layer formed on the transparent base material, a dot pattern formed by a plurality of dots on the base layer, and This is a precision dot pattern printing film having a dot diameter of 50 μm or less, and is excellent in pattern accuracy. Therefore, by using this precision dot pattern printing film as a black matrix, stray light can be prevented and a black matrix having high contrast can be obtained. Furthermore, by using the black matrix for a light diffusion film, a light diffusion film having a wide viewing angle characteristic and high contrast can be obtained. Furthermore, since this light diffusion film can be applied to various display devices including a flat display, its industrial value is extremely large.

  According to the method for producing a precision dot pattern printing film of the present embodiment, a step of forming a base layer on a transparent substrate showing flexibility, and a step of forming a dot pattern consisting of a plurality of dots on the base layer And the step of forming the dot pattern comprises two blades of ink for forming dots on a gravure printing cylinder on which a pattern groove having a shape corresponding to a plurality of dots is formed. And the step of transferring the ink applied on the plate cylinder to the underlayer formed on the transparent substrate, and the transfer of the ink is performed by applying the ink to the underlayer. Since the transfer time from the contact between the plate cylinder and the base layer at the time of the transfer to the separation is 0.5 seconds or more and 10 seconds or less, the dot pattern is extremely small. Formed film , It is possible to manufacture a large area and with high precision. In particular, by using a gravure printing method capable of continuously printing on a long film, a precise dot pattern consisting of a plurality of dots having a diameter of 50 μm or less, particularly preferably a diameter of 15 μm or less, is formed on the long film. Since it can be formed continuously, it is possible to manufacture with a short process and low cost, and it is possible to improve production efficiency and manufacturing cost.

  Therefore, by applying the precision dot pattern printing film manufactured by the method of the present embodiment to various display devices such as a flat display, it becomes possible to improve the mass productivity and reduce the cost. Is extremely large.

  DESCRIPTION OF SYMBOLS 1 ... Precision dot pattern printing film (dot printing film) 2a ... Dot 2 ... Dot pattern 3 ... Underlayer 4 ... Transparent base material 5 ... Transparent film 6 ... Plate cylinder 7 ... Pattern groove 8 ... Dispenser 9 ... Ink 10 ... 1st Blade 11 ... second blade 12 ... backup roll 13a, 13b ... guide roll

Claims (5)

A transparent substrate showing flexibility;
An underlayer formed on the transparent substrate;
A precision dot pattern printing film provided with a dot pattern formed by a plurality of dots on the underlayer,
A precision dot pattern printing film, wherein the dot has a diameter of 50 μm or less.   The precision dot pattern printing film according to claim 1, wherein the dot has a diameter of 15 μm or less.   The dot has a light shielding property, and the dot having the light shielding property has an optical density of 2 or more in a visible light region having a wavelength of 380 nm to 780 nm when the film thickness is 1 μm. The precision dot pattern printing film of Claim 1 or 2. A method for producing a precision dot pattern printing film comprising a transparent base material exhibiting flexibility, a base layer formed on the transparent base material, and a dot pattern formed by a plurality of dots on the base layer Because
Forming a base layer on a transparent substrate showing flexibility;
Forming a dot pattern consisting of a plurality of dots on the underlayer, and further forming the dot pattern,
A step of applying the ink for forming the dots using two blades on the gravure printing cylinder in which pattern grooves having a shape corresponding to the plurality of dots are formed;
Transferring the ink coated on the plate cylinder to an underlayer formed on the transparent substrate,
The transfer of the ink is performed by pressure-bonding the base layer to a plate cylinder on which the ink has been applied, and the transfer time from when the plate cylinder and the base layer come into contact with each other at the time of transfer is determined. The manufacturing method of the precision dot pattern printing film characterized by setting it as 0.5 second or more and 10 seconds or less.   The ink exhibits thixotropy, and the viscosity measured by a rotational viscometer is 100 Pa · s or higher when the rotational speed is 0.5 rpm or lower, and 50 Pa · s or lower when the rotational speed is 10 rpm or higher. The manufacturing method of the precision dot pattern printing film of Claim 4 characterized by the above-mentioned.

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