JP2012056156A - Method for producing long laminate for optical films - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a long laminate for optical films for producing an optical film with a moire phenomenon suppressed when it is attached to a display in a good yield.SOLUTION: The method for producing the long laminate for the optical film which has an external light shielding layer comprising a substrate layer and a plurality of stripe-shaped light absorption parts on at least one side of a long base material film includes a process (a) for laminating the substrate layer on at least one side of the long base material film, a process (b) for forming a plurality of grooves with their longitudinal directions inclined to the longitudinal direction of the long base material film in the substrate layer by an embossed roll having spiral projections, and a process (c) for forming the light absorption parts by packing a light absorbent ink in the grooves after both processes (a) and (b) are completed.

Description

  The present invention relates to a method for producing a long laminate for an optical film, and more specifically, a single-unit optical film (single-sheet optical film) having an external light shielding layer for suppressing a decrease in contrast due to external light. The present invention relates to a method for producing a long laminate for an optical film, which is an intermediate product for production.

  A display such as an organic EL display, a liquid crystal display, or a plasma display is a display device capable of clear full color display. In these displays, an optical film having an antireflection function, an antiglare function, an electromagnetic wave shielding function, a near infrared shielding function, or the like is usually disposed on the viewing side of the display.

  Furthermore, in recent years, in order to suppress a decrease in contrast due to external light, an optical film including an external light shielding layer in which a plurality of light absorbing portions are arranged in a stripe shape has been proposed (for example, Patent Documents 1 to 3). .

  These external light shielding layers are known to be formed by forming striped grooves in a base layer made of an ultraviolet curable resin or the like and filling the grooves with light absorbing ink that absorbs light. .

  On the other hand, when an optical film having the above-described external light shielding layer is disposed on a plasma display device or the like, a moire phenomenon occurs due to periodic pattern interference between the pixels constituting the plasma display device and the optical film. In order to solve this problem, it has been proposed to incline the stripe pattern angle of the light absorbing portion of the external light shielding layer with respect to the horizontal direction (for example, Patent Documents 4 to 4). 6).

JP 2006-189867 A JP 2006-201577 A JP 2008-304673 A JP 2006-313360 A JP 2008-203823 A JP 2009-535673 A

  Conventionally, an optical film having an external light shielding layer is formed by laminating a base layer made of a light-transmitting curable resin on almost the entire surface of a long base film, and forming a striped groove on the base layer. The groove was filled with light absorbing ink. The striped grooves formed in the base layer were formed substantially parallel (horizontal) to the center line in the longitudinal direction (conveying direction) of the long base film.

  As described above, an optical film having an external light shielding layer having an inclined light absorbing portion has been conventionally known, and the conventional manufacturing method thereof is as shown in FIG. 10 in the longitudinal direction of a long base film 42. When the optical film long laminate 41 in which the light absorbing portions 45 are arranged in parallel (horizontal) to the center line Y is manufactured, and the single wafer optical film 40 is cut out from the optical film long laminate 41. It was manufactured by cutting the single wafer optical film 40 diagonally in accordance with the inclination angle of the light absorption part.

  The above-mentioned conventional manufacturing method has a problem that it is wasteful and yield is low because it is necessary to cut the sheet optical film obliquely. Moreover, after laminating | stacking the elongate laminated body for optical films obtained by the conventional manufacturing method, and other elongate functional films (for example, an antireflection film, a near-infrared absorption film, an electromagnetic wave shielding film, etc.), a sheet-fed optical In the case of cutting into a film, the yield was further reduced due to the inclusion of other functional films.

  Therefore, in view of the above problems, an object of the present invention is to provide a method for producing a long laminated body for an optical film for producing an optical film with reduced moire phenomenon when mounted on a display with a high yield. is there.

The above object of the present invention has been basically achieved by the following invention.
1) Step (a) of laminating a base layer on at least one surface of the long base film;
A step (b) of forming a plurality of grooves whose longitudinal direction is inclined with respect to the longitudinal direction of the long base film in the base layer by a molding roll having a spiral projection;
After completing both the step (a) and the step (b), the step (c) of forming a light-absorbing portion by filling the groove with a light-absorbing ink has a long laminate for an optical film. Manufacturing method.
2) The manufacturing method of the elongate laminated body for optical films of said 1) whose inclination | tilt angle (beta) of the spiral processus | protrusion of the said shaping | molding roll is 80-89.5 degrees with respect to the rotating shaft X of this roll.
3) The manufacturing method of the elongate laminated body for optical films of said 1) or 2) with which the said process (a) and the said process (b) are performed substantially simultaneously.
4) The long base film is selected from the group consisting of an antireflection layer, a hard coat layer, a near-infrared shielding layer, a color tone adjustment layer, and an electromagnetic wave shielding layer on the surface opposite to the surface on which the base layer is laminated. The manufacturing method of the elongate laminated body for optical films in any one of said 1) -3) which has an at least 1 functional layer.

  By using the long laminated body for optical films produced by the present invention, it is possible to take out a single unit of optical film (single-sheet optical film) with a high yield.

It is a schematic plan view of an example of the single wafer optical film cut out in the sheet form from the elongate laminated body for optical films manufactured by this invention. It is a schematic cross section of AA of FIG. It is a schematic plan view which shows an example of the elongate laminated body for optical films obtained by this invention. It is the figure which showed typically the flow of the manufacturing method of the elongate laminated body for optical films of this invention. It is a model side view which shows an example of the process (a) in the manufacturing method of the elongate laminated body for optical films of this invention, and a process (b). It is a model side view which shows an example of the process (a) in the manufacturing method of the elongate laminated body for optical films of this invention, and a process (b). It is a model side view which shows an example of the process (a) in the manufacturing method of the elongate laminated body for optical films of this invention, and a process (b). It is a model side view which shows an example of the shaping | molding roll of this invention. It is the elements on larger scale of FIG. It is a schematic plan view which shows an example of the conventional elongate laminated body for optical films.

  FIG. 1 is a schematic plan view of an example of an optical film cut out in a sheet form from the long laminate for an optical film manufactured according to the present invention, and FIG. 2 is a schematic cross-sectional view taken along line AA of FIG. . A line AA in FIG. 2 is a line perpendicular to the light absorbing portion 5.

  The optical film of FIG. 1 is cut into a sheet in units of one sheet according to the size of the display so that it can be attached to the display, and is hereinafter referred to as a single wafer optical film. Moreover, the long laminated body for optical films manufactured by this invention is called the long laminated body for optical films of this invention, and the sheet | seat optical film cut out from this long laminated body for optical films is the sheet | seat of this invention. It is called a leaf optical film.

  The single-wafer optical film 1 of the present invention is obtained by laminating an external light shielding layer 3 on a base film 2. The external light shielding layer 3 is formed by forming a plurality of linear light absorbing portions 5 in a stripe shape on the base layer 4. And the light absorption part 5 is arrange | positioned so that it may incline slightly.

  The planar shape of the single-wafer optical film of the present invention is a rectangle, and the acute angle size α (hereinafter referred to as the inclination angle α of the light absorbing portion) formed by the long side and the light absorbing portion 5 is 0.5 to 10 degrees. The range of is preferable. Thereby, it is possible to suppress a moire phenomenon when a single-wafer optical film having an external light shielding layer is mounted on a display. The inclination angle α of the light absorbing portion is preferably in the range of 1 to 8 degrees, more preferably in the range of 1.5 to 7 degrees.

  Although FIG. 1 shows an example in which the light absorbing portion 5 is inclined downward to the right, in the present invention, the light absorbing portion 5 may be inclined upward to the right.

  In the single-wafer optical film of the present invention, the height h of the light absorbing portion 5 is preferably in the range of 20 to 200 μm, more preferably in the range of 30 to 150 μm, and particularly preferably in the range of 50 to 130 μm. The maximum width W of the light absorbing portion 5 is preferably in the range of 3 to 20 μm, and more preferably in the range of 5 to 15 μm. The pitch P of the plurality of arranged light absorbing portions is preferably in the range of 20 to 200 μm, and more preferably in the range of 30 to 150 μm. Moreover, the cross-sectional shape of the light absorption part is preferably a trapezoid, a triangle, or a rectangle, and particularly preferably a trapezoid or a triangle.

  Conventionally, a single wafer optical film having an outside light shielding layer in which the light absorbing portion is inclined has been known. However, as described above, the conventional manufacturing method has a problem that it is wasteful and yield is low because it is necessary to cut the sheet optical film obliquely.

  Therefore, the present invention can produce a long laminated body 11 for an optical film as shown in FIG. 3, and by using the long laminated body 11, the single wafer optical film 10 can be efficiently cut out without waste, I found that the yield improved.

  That is, the long laminate 11 for an optical film of the present invention is formed so that the light absorbing portion 15 is inclined at a predetermined angle with respect to the longitudinal center line Y of the long base film 12. The rectangular sheet-like optical film 10 can be cut out so that the long sides thereof are parallel to the center line Y. As a result, a single-wafer optical film can be produced efficiently without waste.

  The light absorbing portion 15 is inclined with respect to the center line Y at an acute angle θ (hereinafter referred to as an inclination angle θ), and this inclination angle θ is substantially equal to the inclination angle α of the cut-off sheet optical film. Formed to match. Therefore, the inclination angle θ of the light absorbing portion in the long laminated body 11 for optical films of the present invention is preferably in the range of 0.5 to 10 degrees, more preferably in the range of 1 to 8 degrees, and particularly 1.5 to 7. A range of degrees is preferred.

  Although FIG. 3 shows an example in which the light absorbing portion 15 is inclined downward to the right, in the present invention, the light absorbing portion 15 may be inclined to the right upward.

  Hereinafter, the manufacturing method of the elongate laminated body for optical films of this invention as shown in FIG. 3 is demonstrated.

  FIG. 4 is a diagram schematically showing the flow of the method for producing the long laminate for an optical film of the present invention, and is a schematic cross-sectional view orthogonal to the longitudinal direction of the long base film 12.

  The method for producing a long laminate for an optical film of the present invention comprises a step (a) of laminating a base layer on at least one surface of a long base film, and a long base film on the base layer by a molding roll. After the step (b) of forming the groove whose longitudinal direction is inclined with respect to the longitudinal direction of the ink, and both the step (a) and the step (b) are completed, the light-absorbing ink is formed in the groove formed in the step (b). And (c) forming a light-absorbing portion. Here, “after both the step (a) and the step (b) are completed” does not mean that the step (c) is performed after the step (a) and the step (b), but the step (a ) And step (b) are completed before step (c) is performed.

  In the present invention, as will be described in detail later, the base layer and the light-absorbing ink preferably contain an active energy ray-curable resin, and are preferably cured by irradiation with an active energy ray such as an electron beam or ultraviolet ray.

  Hereinafter, each of the above steps will be described in detail.

  Step (a) and step (b) may be performed independently or simultaneously.

  The aspect which performs a process (a) and a process (b) independently is 1) The method of forming a groove | channel in a base layer, after laminating | stacking (coating) a base layer on a elongate base film. In this case, it is preferable that the base layer is cured by irradiating an active energy ray almost simultaneously with the formation of the groove by applying the mold roll to the base layer.

  As an aspect which performs a process (a) and a process (b) simultaneously, 2) A base layer-forming coating material is supplied between a long base film and a mold roll, and between a long base film and a mold roll 3) A method of irradiating and curing an active energy ray in a state where a base layer is formed, 3) After supplying a base layer-forming coating material to a mold roll, a long base film is applied to the mold roll and between the two Method of irradiating and curing active energy rays in the state where the base layer is formed 4) Irradiating active energy rays almost simultaneously with transferring the base layer forming coating material supplied to the mold roll to the long base film 5) Supplying a base layer-forming coating material to the mold roll and curing or semi-curing it by irradiating with active energy rays while the base layer is in close contact with the mold roll, Formed Method of transferring a base layer on the elongate base material films, and the like.

  Among the embodiments described above, the methods 2), 3), and 4) are preferably used. An example of each of the above aspects 2), 3) and 4) is shown in FIGS.

  FIG. 5 is a schematic side view showing an example of the aspect 2). A coating material is supplied from the base layer forming coating material supply device 32 between the long base film 12 and the mold roll 30 continuously conveyed in the direction of the arrow, and the long base film 12 and the mold roll 30 With the base layer (not shown) formed therebetween, the base layer is cured by irradiating ultraviolet rays, which are active energy rays, from the ultraviolet irradiation device 33.

  FIG. 6 is a schematic side view showing an example of the aspect 3). After the coating material is supplied from the substrate layer forming coating material supply device 32 to the shaping roll 30 and the coating amount is adjusted by the blade 34, the long base film 12 continuously conveyed in the direction of the arrow is applied to the shaping roll 30. Then, with the base layer (not shown) formed between them, the base layer is cured by irradiating with ultraviolet rays, which are active energy rays, from the ultraviolet irradiation device 33.

  FIG. 7 is a schematic side view showing an example of the aspect 4). The mold roll 30 scoops up the paint stored in the base layer-forming paint storage container 35, and after the coating amount is adjusted by the blade 34, the mold roll 30 is applied to the long base film 12 continuously conveyed in the direction of the arrow. The substrate layer is formed by irradiating the ultraviolet ray, which is an active energy ray, from the ultraviolet ray irradiation device 33 while transferring the paint.

  After the above-described step (a) and step (b), the base layer in which a plurality of stripe-shaped grooves were formed was laminated on the long base film, and then provided in the base layer in step (c). The groove is filled with light absorbing ink.

  The light-absorbing ink can be filled by supplying light-absorbing ink to almost the entire surface of the base layer including the groove, and then wiping or squeezing the surface of the base layer to adhere to the surface of the base layer other than the groove. A method of removing the absorbent ink and filling only the groove with the light absorbent ink can be used. It is preferable to cure the light-absorbing ink by irradiating active energy rays after filling the groove with the light-absorbing ink.

  The present invention is characterized by a molding roll for forming grooves in the base layer in the step (b). The embossing roll of the present invention has a spiral protrusion on the peripheral surface of the roll, and the spiral protrusion forms a linear groove in the base layer in a stripe shape. And the inclination angle of the spiral projection is designed in accordance with the inclination angle θ of the light absorbing portion of the long laminate for optical film.

The inclination angle of the spiral protrusion of the embossing roll according to the present invention can be represented by the inclination angle β of the spiral protrusion with respect to the rotation axis of the embossing roll (see FIG. 9). This inclination angle β is an angle obtained by subtracting the inclination angle θ of the light absorbing portion of the long laminated body for optical films from 90 degrees, and the relational expression between them is as follows.
Inclination angle β = 90 degrees−inclination angle θ Formula 1

  FIG. 8 is a schematic side view showing an example of the mold roll of the present invention. In the embossing roll of the present invention, spiral protrusions 31 are provided at a predetermined inclination angle on the circumferential surface of the roll.

  It is preferable that a plurality of spiral protrusions in the shaping roll of the present invention are arranged in multiple spirals.

The design roll of the present invention is designed such that the pitch P (μm) of the light absorbing portion and the inclination angle θ of the light absorbing portion, the diameter D (mm) of the shaping roll, and the spiral of the spiral protrusion in the long laminated body for optical films. The number n (n-fold helix) is designed to satisfy the following relationship.
Tan θ = {(P / cos θ) × n} / 1000πD
That is, sin θ = (P × n) / 1000πD Equation 2

  The diameter D of the molding roll can be appropriately designed according to the manufacturing apparatus in which the roll is incorporated, but the spiral number n of the spiral protrusions must be designed to be an integer, and adjustment for that It is necessary to adjust by the diameter D of the molding roll (because the pitch P of the light absorption part and the inclination angle θ of the light absorption part in the long laminated body for optical films are determined). The above formula 2 makes it possible to produce a mold roll having helical protrusions having an arbitrary inclination angle.

  In addition, in this invention, the pitch P of the light absorption part in the elongate laminated body for optical films and the pitch Pr (shown in FIG. 9) of the spiral protrusion of a shaping roll are the same.

  The number n of spirals is the number of spirals when the spiral protrusion is formed of multiple spirals, and is the number of independent spiral protrusions. The spiral number n will be described with reference to FIG. FIG. 9 is a partially enlarged view of FIG. The number of spirals n is the number of spiral projections existing in the length L (the length of the roll circumferential surface parallel to the rotation axis X of the roll) necessary for one spiral projection 31 to make one round of the roll. It is.

  It is produced based on the diameter D of the molding roll determined by the above formula 2, the number of spirals n of the spiral protrusions, and the pitch Pr of the spiral protrusions (same as the pitch P of the light absorbing portion of the long laminated body for optical films). The inclination angle β of the spiral protrusions of the typed roll satisfies the relationship of the above formula 1.

  One specific example when the mold roll is designed using the above formula 2 is shown below.

  When the pitch P of the light absorbing portion of the long laminated body for an optical film is 50 μm and the inclination angle θ of the light absorbing portion is 5 degrees, the number n of spirals of the spiral protrusions calculated by the above formula 2 is 500. The diameter D of the roll is 91.3 mm.

  As described above, the inclination angle θ of the light absorbing portion in the long laminate for an optical film obtained by the production method of the present invention is preferably in the range of 0.5 to 10 degrees, more preferably in the range of 1 to 8 degrees. The range of 1.5 to 7 degrees is particularly preferable. Therefore, from the above formula 1, the inclination angle of the spiral protrusions in the mold roll used in the present invention is preferably in the range of 80 to 89.5 degrees, more preferably in the range of 82 to 89 degrees, and particularly 83 to 88.5. A range of degrees is preferred.

  Further, the cross-sectional shape and height and width of the spiral protrusion of the embossing roll of the present invention are designed in accordance with the cross-sectional shape, height h and width W of the light absorbing portion 5 of the single-wafer optical film which is the final product. (See FIG. 2).

  The embossing roll according to the present invention has been difficult by a conventional general embossing roll manufacturing method, for example, a so-called bite machining method in which a roll peripheral surface is scraped to form protrusions. Therefore, the long laminated body for optical films in which the light absorption part of this invention inclined is not yet proposed.

  The embossing roll of the present invention can be manufactured, for example, by a so-called additive method in which protrusions are added to the peripheral surface of the roll.

  Such a manufacturing method includes the following steps. 1) After the roll peripheral surface is coated with a photocurable resin layer on the peripheral surface of a roll made of a metal such as nickel, this photocurable resin layer is irradiated spirally with a laser (the portion irradiated with the laser is cured) The unirradiated part is uncured). 2) Next, the photocurable resin layer is developed and uncured portions that are not irradiated with laser are dissolved and removed to form spiral grooves in the photocurable resin layer (this spiral groove). Becomes a spiral projection in a later plating step). 3) Next, the metal exposed at the bottom of the groove formed in the photocurable resin layer is plated to form a plated metal portion in the groove. 4) Next, by dissolving and removing the remaining photocurable resin layer, spiral protrusions composed of plated metal portions appear on the peripheral surface of the roll.

  It is preferable that the base layer which comprises the external light shielding layer concerning this invention is provided in the substantially whole surface of a elongate base film. Such a base layer is light transmissive and preferably contains an active energy ray-curable resin. The content of the active energy ray-curable resin in the base layer is preferably 50% by weight or more, preferably 60% by weight or more, particularly 70% by weight, based on 100% by weight of the total solid content of the base layer. The above is preferable. The upper limit is about 98% by mass.

  As such an active energy ray-curable resin, for example, a monomer or oligomer (including a prepolymer) having an ethylenically unsaturated double bond group such as a (meth) acryl group or a vinyl group in the molecule can be used. In particular, a polyfunctional acrylate compound having two or more ethylenically unsaturated double bond groups in the molecule is preferably used.

  Examples of such polyfunctional acrylate compounds include pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, and dipentaerythritol penta (meth). Acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer Etc. can be used. These may be used alone or in combination of two or more.

  When ultraviolet rays are used to cure the active energy ray-curable resin, it is preferable to include a photopolymerization initiator in the light-absorbing ink.

  The light absorbing portion constituting the external light shielding layer is formed by filling a groove formed in the base layer with light absorbing ink. As such a light absorbing ink, for example, an ink containing a resin component and a colorant can be used.

  As the resin component, a resin curable with an active energy ray such as an ultraviolet ray or an electron beam, a thermosetting resin, or the like can be used. In particular, an active energy ray curable resin is preferable because it has a high curing rate and excellent productivity.

  As the active energy ray-curable resin, for example, a monomer or oligomer having an ethylenically unsaturated double bond group such as a (meth) acryl group or a vinyl group in the molecule can be used. In particular, a polyfunctional acrylate compound having two or more ethylenically unsaturated double bond groups in the molecule is preferably used.

  As such a polyfunctional acrylate compound, the same compounds as those described in the base layer can be used.

  When ultraviolet rays are used to cure the active energy ray-curable resin, it is preferable to include a photopolymerization initiator in the light-absorbing ink.

  Various pigments and dyes can be used as the colorant contained in the light-absorbing ink. As the colorant, a pigment is preferable. For example, a black pigment or a mixture of a red pigment, a blue pigment and a green pigment can be contained. Among these, a black pigment is particularly preferable.

  As the black pigment, Color Index No. Pigment black 7, carbon black, titanium black, metal oxide, and the like. These pigments may be used alone or in combination of two or more.

  The content of the colorant is suitably in the range of 5 to 200% by mass and preferably in the range of 10 to 150% by mass with respect to 100% by mass of the resin component.

  The length in the longitudinal direction of the long laminate for an optical film of the present invention is a length that allows at least a plurality of single-wafer optical films to be taken in the longitudinal direction, and is preferably a length that allows for taking 10 or more single-wafer optical films. More preferably, the length is such that 100 or more single-wafer optical films can be taken. 30 m or more is preferable, as for the specific length of the elongate laminated body for optical films, 100 m or more is more preferable, and it is still more preferable that it is 200 m or more. The upper limit is about 2000 m.

  The length of the long base film used in the long laminate for optical films of the present invention is preferably equal to or longer than the length of the long laminate for optical films.

  The long base film according to the present invention is preferably a plastic film. Examples of the resin constituting the plastic film include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as triacetyl cellulose, polyolefin resins such as polyethylene, polypropylene, and polybutylene, acrylic resins, polycarbonate resins, arton resins, and epoxy resins. , Polyimide resin, polyetherimide resin, polyamide resin, polysulfone resin, polyphenylene sulfide resin, polyether sulfone resin, and the like. Among these, polyester resins, polyolefin resins and cellulose resins are preferable, polyester resins are more preferable, and polyethylene terephthalate is particularly preferable. Further, a laminated plastic film in which two or more layers made of the above resin are laminated may be used.

  The range of 30-300 micrometers is suitable for the thickness of a long base film, and the range of 50-200 micrometers is preferable.

  The long base film is preferably pre-laminated with an easy-adhesion layer in order to reinforce the adhesion with the base layer or a functional layer described later. The easy adhesion layer is preferably formed mainly of a resin such as a polyester resin, an acrylic resin, or a urethane resin. Here, the resin as a main component means that the resin is contained in an amount of 50% by mass or more, preferably 60% by mass or more, particularly 70% by mass or more, based on 100% by mass of the total solid content of the easy-adhesion layer. Is to include. The upper limit is about 98% by mass.

  The easy-adhesion layer preferably further contains a crosslinking agent. Examples of such crosslinking agents include melamine crosslinking agents, oxazoline crosslinking agents, carbodiimide crosslinking agents, isocyanate crosslinking agents, aziridine crosslinking agents, and epoxy crosslinking agents. Among these, melamine-based crosslinking agents, oxazoline-based crosslinking agents, and carbodiimide-based crosslinking agents are preferably used.

  The easy-adhesion layer preferably contains inorganic fine particles in order to further improve the slipperiness and blocking resistance. As such inorganic fine particles, colloidal silica is preferably used.

  The range of 5-300 nm is preferable and, as for the thickness of an easily bonding layer, the range of 10-200 nm is more preferable.

  The long laminate for an optical film according to the present invention may be provided with an external light shielding layer only on one side of the long base film, or may be provided with an external light shielding layer on both sides of the long base film. Good. Preferably, in the present invention, an external light shielding layer is provided on one surface of the long base film, and a functional layer other than the external light shielding layer is provided on the opposite surface (the surface opposite to the surface on which the external light shielding layer is provided). It is the obtained elongate laminated body for optical films.

  The functional layer other than the external light shielding layer is not particularly limited, and may be composed of a single layer or a plurality of layers. The functional layer preferably includes at least one layer selected from, for example, an antireflection layer, a hard coat layer, a near infrared shielding layer, a color tone adjustment layer, and an electromagnetic wave shielding layer, and particularly preferably includes an antireflection layer. .

  Therefore, the long base film used in the method for producing a long laminate for an optical film of the present invention has a functional layer other than the external light shielding layer on the surface opposite to the side on which the external light shielding layer is laminated, for example, It is preferable that at least one layer selected from an antireflection layer, a hard coat layer, a near-infrared shielding layer, a color tone adjustment layer, and an electromagnetic wave shielding layer is laminated in advance.

  The functional layer provided on the side opposite to the side on which the external light shielding layer is laminated of the long base film preferably includes at least an antireflection layer, and in particular, a hard coat layer and an antireflection layer are laminated in this order. It is preferable that it is the structure. Such an antireflection layer may have a laminated structure of a high refractive index layer and a low refractive index layer, or may be composed of a single layer of a low refractive index layer. One layer.

  The hard coat layer preferably has a high hardness to prevent scratches on the surface of the antireflection layer, and the pencil hardness defined by JIS K5600-5-4 (1999) is preferably H or more. 2H or more is more preferable. The upper limit is about 9H.

  The hard coat layer preferably contains a thermosetting resin or an active energy ray curable resin as a resin component, and further preferably contains an active energy ray curable resin that is cured by an active energy ray such as an ultraviolet ray or an electron beam. . In particular, an active energy ray-curable acrylic resin is preferable.

  The hard coat layer preferably contains metal oxide particles in order to further increase the refractive index or impart antistatic properties. Examples of such metal oxide particles include titanium oxide, zirconium oxide, zinc oxide, tin oxide, antimony oxide, cerium oxide, iron oxide, zinc antimonate, tin oxide-doped indium oxide (ITO), and antimony-doped tin oxide (ATO). ), Phosphorus-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, and the like. The content of the metal oxide particles in the hard coat layer is preferably 20% by mass or more, more preferably 30% by mass or more, particularly 40% by mass with respect to 100% by mass of the solid content of the hard coat layer. The above is preferable. The upper limit is about 80% by mass.

  The refractive index of the hard coat layer is preferably in the range of 1.5 to 1.8, more preferably in the range of 1.53 to 1.7, and particularly preferably in the range of 1.55 to 1.67. The thickness of the hard coat layer is suitably in the range of 0.5 to 10 μm, preferably in the range of 0.5 to 7 μm, more preferably in the range of 1 to 5 μm, and particularly preferably in the range of 1.5 to 3 μm.

  As described above, the antireflection layer laminated on the hard coat layer is preferably a single layer of a low refractive index layer. The refractive index of the low refractive index layer is preferably in the range of 1.25 to 1.45, more preferably in the range of 1.30 to 1.43, and particularly preferably in the range of 1.30 to 1.40.

  The thickness of the low refractive index layer is preferably in the range of 0.05 to 0.15 μm, particularly preferably in the range of 0.08 to 0.12 μm.

  The low refractive index layer is a layer containing an active energy ray-curable resin that is cured by active energy rays such as ultraviolet rays and electron beams, and low refractive index inorganic particles and / or fluorine-containing compounds as a low refractive index material. preferable. As the active energy ray curable resin, an acrylic resin is preferable.

  As the low refractive index inorganic particles, inorganic particles such as silica and magnesium fluoride are preferably used. Further, these inorganic particles are preferably hollow or porous. The refractive index of the inorganic particles is preferably in the range of 1.2 to 1.4, more preferably in the range of 1.2 to 1.35.

  Examples of the fluorine-containing compound include a fluorine-containing monomer and a fluorine-containing polymer compound.

  Examples of the fluorine-containing monomer include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ethyl (meth) ) Acrylate, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, and other fluorine-containing (meth) acrylic acids Examples include esters.

  Examples of the fluorine-containing polymer compound include a fluorine-containing copolymer having a fluorine-containing monomer and a monomer for imparting a crosslinkable group as constituent units. Specific examples of the fluorine-containing monomer unit include, for example, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoro-2,2-dimethyl-1,3-dioxole, etc. ), (Meth) acrylic acid partial or fully fluorinated alkyl ester derivatives (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fully or partially fluorinated vinyl ethers, and the like. As a monomer for imparting a crosslinkable group, in addition to a (meth) acrylate monomer having a crosslinkable functional group in the molecule like glycidyl methacrylate, it has a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, etc. ) Acrylate monomers (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, etc.).

  Furthermore, the long base film used for the long laminated body for optical films of the present invention has a polyester film (especially polyethylene terephthalate is preferable) on one surface with an easy-adhesion layer (A) mainly composed of a polyester resin. The hard coat layer and the antireflection layer are laminated in this order, and the easy adhesion layer (B) mainly composed of an acrylic resin and / or a urethane resin is previously formed on the other surface (the surface on which the external light shielding layer is laminated). It is preferable that they are laminated.

  Here, the easy-adhesion layer (A) contains a polyester resin as a main component means that it contains 50% by mass or more, preferably 60% by mass or more, based on 100% by mass of the total solid content of the easy-adhesion layer (A). In particular, it is preferably 70% by mass or more. The upper limit is about 98% by mass. Similarly, that the easy-adhesion layer (B) is mainly composed of an acrylic resin and / or a urethane resin means that it contains 50% by mass or more with respect to 100% by mass of the total solid content of the easy-adhesion layer (B), Is to contain 60% by mass or more, particularly preferably 70% by mass or more. The upper limit is about 98% by mass.

  By using the easy-adhesion layer (A) and the easy-adhesion layer (B), the adhesion of the hard coat layer and the external light shielding layer to the polyester film is improved, and it is also effective in reducing interference fringes on the antireflection surface. Become.

  As described above, it is preferable that the easy-adhesion layer (A) and the easy-adhesion layer (B) further contain a crosslinking agent and particles.

  As described above, when a long base film having a functional layer previously laminated on the side opposite to the side on which the external light shielding layer is laminated, is used as the long base film. In order to further improve the added value of the long laminated body for optics, it is extremely significant that the single-wafer optical film can be efficiently cut out without waste as in the present invention.

DESCRIPTION OF SYMBOLS 1, 10, 40 Sheet-fed optical film 2 Base film 3, 13 External light shielding layer 4, 14 Base layer 5, 15, 45 Light absorption part 11, 41 Long laminated body for optical films 12, 42 Long base material Film 30 Molding roll 31 Spiral protrusion 32 Supply device 33 for base layer forming paint UV irradiation device 34 Blade 35 Storage container for base layer forming paint M Groove

Claims (4)

A step (a) of laminating a base layer on at least one surface of the long substrate film;
A step (b) of forming a plurality of grooves whose longitudinal direction is inclined with respect to the longitudinal direction of the long base film in the base layer by a molding roll having a spiral projection;
After completing both the step (a) and the step (b), the step (c) of forming a light-absorbing portion by filling the groove with a light-absorbing ink has a long laminate for an optical film. Manufacturing method.   The manufacturing method of the elongate laminated body for optical films of Claim 1 whose inclination | tilt angle (beta) of the helical processus | protrusion of the said forming roll is 80-89.5 degree | times with respect to the rotating shaft X of this roll.   The manufacturing method of the elongate laminated body for optical films of Claim 1 or 2 with which the said process (a) and the said process (b) are performed substantially simultaneously.   The long base film is at least one selected from the group consisting of an antireflection layer, a hard coat layer, a near-infrared shielding layer, a color tone adjusting layer, and an electromagnetic wave shielding layer on the surface opposite to the surface on which the base layer is laminated. The manufacturing method of the elongate laminated body for optical films in any one of Claims 1-3 which has one functional layer.

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