KR20180116314A - Method for producing laminated optical film - Google Patents

Abstract

The present invention provides a method for producing a laminated optical film capable of preventing dirt on a bonding roll by an adhesive or an adhesive used for bonding optical films.
A method of producing a laminated optical film in which a first optical film 2, an adhesive layer 5 and a second optical film 3 are introduced between a pair of rotating bonding rolls 7a and 7b to bond them together The width W _A of the adhesive layer 5 is equal to or greater than the width W _{1 of} the first optical film 2 and the position of the first optical film 2 in the width direction is equal to or greater than the width W ₁ of the adhesive layer width (W ₂₎ has a width (greater than W _a), the second optical film (3) of the adhesive layer 5 of 5) present a width (W _a), within, and the second optical film (3) of the adhesive layer (5) presence width (W _a) to and located so as to nest, the first optical film (2) side between the bonding roll (7a) and the first optical film (2), width (W of the adhesive layer 5 of The third optical film 6 having a width larger than the width _{A of the} adhesive layer 5 is interposed so as to enclose the width W _A of the adhesive layer 5.

Description

Method for producing laminated optical film

The present invention relates to a method for producing a laminated optical film.

Conventionally, a method for producing a laminated optical film is known in which a plurality of optical films are passed through a pair of bonding rolls through an adhesive layer or a pressure-sensitive adhesive layer to press them together (see, for example, Patent Document 1). The adhesive layer or the pressure-sensitive adhesive layer is usually supplied by applying an adhesive or a pressure-sensitive adhesive to either one of the optical films to be laminated.

Japanese Patent Application Laid-Open No. 2014-172290

In the bonding, when the adhesive or pressure-sensitive adhesive is released from the end portion in the width direction of the optical film, an adhesive or a pressure-sensitive adhesive adheres to the bonding roll and becomes dirty. The adhesive or pressure-sensitive adhesive adhered to the bonding roll may cause blocking when the laminated optical film is rolled up in the form of a roll by electrodeposition onto a subsequent optical film.

An object of the present invention is to provide a method for producing a laminated optical film capable of preventing dirt on a bonding roll by an adhesive or an adhesive used for bonding optical films.

In the present invention, a first optical film, an adhesive layer or a pressure-sensitive adhesive layer, and a second optical film are introduced between a rotating pair of bonding rolls in such a manner that the pair of bonding rolls are arranged in this order Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer at the time of bonding is not less than the width of the first optical film, and the width of the first optical film in the width direction Is located within the width of the adhesive layer or the pressure-sensitive adhesive layer, the width of the second optical film is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer, and the second optical film is positioned to contain the width of the adhesive layer or the pressure- A third optical film having a width larger than the width of the adhesive layer or the pressure-sensitive adhesive layer is interposed between the bonding roll on the first optical film side and the first optical film so that the width of the adhesive layer or the pressure- , And a method for producing a laminated optical film.

According to this manufacturing method, at the time of bonding the first optical film and the second optical film, a second optical film or a third optical film that is wider than the adhesive layer or the pressure-sensitive adhesive layer is provided between the adhesive layer or the pressure- It is possible to prevent dirt on the joining roll by the adhesive or the pressure-sensitive adhesive.

In this manufacturing method, the width of the bonding roll on the first optical film side is smaller than the width of the third optical film, and the position of the bonding roll on the first optical film side in the width direction is within the width of the third optical film May be used. In this case, it is further prevented that the bonding roll is dirty by the adhesive or the pressure-sensitive adhesive.

In another aspect of the present invention, a first optical film, an adhesive layer or a pressure-sensitive adhesive layer, and a second optical film are arranged in this order in the direction of connecting the pair of bonding rolls between a pair of rotating rolls Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer is equal to or greater than the width of the first optical film at the time of bonding, and the first optical film and the second optical film are bonded together, The width of the second optical film is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer, and the width of the second optical film is the width of the adhesive layer or the pressure- Wherein the width of the bonding roll on the first optical film side is smaller than the width of the first optical film and the position of the bonding roll on the first optical film side is within the existing width of the first optical film, ore It provides a process for the production of film.

According to this manufacturing method, although the adhesive layer or the pressure-sensitive adhesive layer is evacuated from the existing width of the first optical film, the width of the bonding roll on the first optical film side is smaller than the width of the first optical film, Since the position of the bonding roll on the film side in the width direction is within the existing width of the first optical film, the bonding roll is prevented from being dirty by the adhesive or the adhesive.

According to another aspect of the present invention, there is provided a process for producing a laminated film, comprising the steps of: providing a first optical film, an adhesive layer or a pressure-sensitive adhesive layer, and a second optical film in this order Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer at the time of bonding is less than the width of the first optical film, The width of the second optical film is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer, and the second optical film is in the presence of the adhesive layer or the pressure-sensitive adhesive layer And the width of the first and second optical films is within a range of from 1 to 100 nm.

According to this manufacturing method, since the possibility that the adhesive layer or the pressure-sensitive adhesive layer is released from the width of the first optical film and the second optical film is very small, dirt of the bonding roll by the adhesive or the pressure-sensitive adhesive can be prevented.

In this manufacturing method, the width of the bonding roll on the first optical film side is smaller than the width of the first optical film, and the position on the first optical film side in the width direction is within the width of the first optical film May be used. In this case, it is further prevented that the bonding roll is dirty by the adhesive or the pressure-sensitive adhesive.

In this manufacturing method, the width of the adhesive layer or the pressure-sensitive adhesive layer may be 0.1 to 50 mm smaller than the width of the first optical film. In this case, the first optical film and the second optical film can be sufficiently adhered or adhered to the ends in the width direction.

In each of the above-described manufacturing methods, the first optical film has the optical functional layer provided on one side or both sides of the resin base and the resin base, the resin base and the optical functional layer are equal in width to each other, 1 optical film may be disposed such that the optical function layer side faces the adhesive layer or the pressure-sensitive adhesive layer side, and the second optical film is a protective film. In this embodiment, the first optical film has the resin substrate and the optical functional layer, and the thickness of the end portion in the width direction is stable.

The optical function layer may be a polarizer, and the polarizer may be coated on the resin substrate.

According to another aspect of the present invention, there is provided a method for producing a laminated film, comprising the steps of: providing a resin substrate, an optical functional layer provided on one side or both sides of the resin substrate, an adhesive layer or a pressure sensitive adhesive layer and a protective film between a pair of bonding rolls Wherein the width of the optical functional layer is smaller than the width of the resin substrate at the time of bonding, and the width of the optical functional layer is smaller than the width of the resin substrate at the time of bonding, The width of the adhesive layer or the pressure-sensitive adhesive layer is not less than the width of the optical function layer and is smaller than the width of the resin base material, the resin base material is positioned so as to contain the width of the optical function layer and the adhesive layer or the pressure- Is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer, and the protective film is positioned so as to contain the width of the adhesive layer or the pressure-sensitive adhesive layer. do.

According to this manufacturing method, since a resin base material or protective film having a wider width than the adhesive layer or the pressure-sensitive adhesive layer is interposed between the adhesive layer or the pressure-sensitive adhesive layer and the bonding roll at the time of bonding the optical functional layer and the protective film, Or dirt of the bonding roll by the pressure-sensitive adhesive can be prevented.

In this manufacturing method, the width of the bonding roll on the resin substrate side may be smaller than the width of the resin substrate, and the position of the bonding roll on the resin substrate side may be within the width of the resin substrate . In this case, it is further prevented that the bonding roll is dirty by the adhesive or the pressure-sensitive adhesive.

In this manufacturing method, the optical functional layer may be a polarizer, and the polarizer may be coated on the resin base material.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing a laminated optical film capable of preventing dirt on a bonding roll by an adhesive or an adhesive used for bonding optical films.

1 is a cross-sectional view of a laminated optical film produced by the manufacturing method of the first embodiment.
2 is a view showing the manufacturing method of the first embodiment.
Fig. 3 is a cross-sectional view taken along the line III-III in Fig. 2, showing the lamination state at the time of bonding according to the first embodiment.
4 is a cross-sectional view of a laminated optical film produced by the manufacturing method of the second embodiment.
5 is a view showing a manufacturing method of the second embodiment.
Fig. 6 is a cross-sectional view taken along the line VI-VI in Fig. 5, showing the lamination state at the time of bonding according to the second embodiment.
7 is a cross-sectional view of a laminated optical film produced by the manufacturing method of the third embodiment.
8 is a view showing a lamination state at the time of bonding according to the third embodiment.
9 is a cross-sectional view of a laminated optical film produced by the manufacturing method of the fourth embodiment.
10 is a view showing a lamination state at the time of bonding according to the fourth embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent parts are denoted by the same reference numerals, and a duplicate description thereof will be omitted. In addition, the dimensional ratios of the respective drawings do not always coincide with actual ones, and in particular, the thickness and width of the film are exaggerated.

≪ First Embodiment >

(Laminated optical film)

1, the laminated optical film 1A produced according to the method for producing a laminated optical film of the first embodiment is obtained by laminating the second optical film 3 on one surface of the first optical film 2, And the third optical film 6 is laminated on the other surface of the first optical film 2. The third optical film 6 is laminated on the other surface of the first optical film 2 through the adhesive layer 5. [ The first optical film 2 has two layers, that is, a resin base material 21 and a polarizer 22 provided on one surface thereof, and they are peelable from each other.

In the first optical film 2, the resin base material 21 and the polarizer 22 are equal in width to each other so that both ends thereof are aligned. In the first optical film 2, the polarizer 22 side is bonded to the adhesive layer 5) side. In the present specification, the "width" of each optical film refers to the width in the extending direction of the bonding roll, which is perpendicular to the carrying direction of each optical film in the production of the laminated optical film 1A. In addition, the expressions " large " and " small " are used for the relative magnitude of the width of each film (the magnitude relation).

The laminated optical film 1A is a laminated optical film 1A in which a third optical film 6 and a resin base material 21 are removed and a polarizing plate 10 having a polarizer 22 and a second optical film ). The polarizing plate 10 may be provided with an optical film other than the protective film on the side of the peeled resin base material 21 or the second optical film 3 through an adhesive layer or a pressure sensitive adhesive layer.

The magnitude and positional relationship of the widths of the first optical film 2, the second optical film 3, the third optical film 6 and the adhesive layer 5 will be described later, The center axes in the respective width directions are roughly arranged. That is, in the cross-sectional view shown in Fig. 1, the lamination mode is substantially symmetrical.

Here, the constitution of each film and the adhesive layer 5 will be described. As the material of the polarizer 22, known materials conventionally used in the production of a polarizing plate can be used. Examples of the material include a polyvinyl alcohol resin, a polyvinyl acetate resin, an ethylene / vinyl acetate (EVA) resin, And polyester-based resins. Among them, a polyvinyl alcohol-based resin is preferable. These materials are subjected to a stretching treatment, dyeing with iodine or a dichroic dye, and boric acid treatment to obtain a polarizer 22 of film type. The laminated body obtained by cutting the polarizer 22 of the film type to an arbitrary size may be the first optical film 2 or the resin substrate 21 bonded to one side or both sides thereof with an adhesive, The film 2 may be used.

As a method for forming the polarizer 22, a coating solution obtained by dissolving the material of the polarizer 22 on one or both surfaces of the resin base material 21 is coated with a thin film (film type) and dried, Dyeing with iodine or a dichroic dye and boric acid treatment may be performed. Thereafter, the first optical film 2 can be obtained by cutting the resin base material 21 to an arbitrary size.

Examples of the stretching treatment method include longitudinal stretching in the film longitudinal direction (film transport direction), transverse stretching in the film width direction, or oblique stretching. Examples of the longitudinal stretching method include inter-roll stretching and compression stretching, and the transverse stretching method includes a tenter method and the like. Any of the wet stretching method and the dry stretching method can be employed for the stretching treatment, but a dry stretching method is preferred, because the stretching temperature can be selected within a wide range.

The thickness of the polarizer 22 is preferably 2 to 75 占 퐉, more preferably 2 to 50 占 퐉, and still more preferably 2 to 30 占 퐉.

The resin base material 21 has a role as a support for coating the polarizer 22 in a thin film form (film form) and for protecting the surface of the polarizer 22, and various resin materials can be used. Examples of the material of the resin base material 21 include polyethylene terephthalate (PET) resin, polypropylene resin and polycarbonate resin.

The thickness of the resin base material 21 is preferably 20 to 500 mu m, more preferably 30 to 300 mu m, and still more preferably 50 to 200 mu m.

The second optical film 3 is here a protective film 3 and the third optical film 6 is a guard film 6.

The protective film (3) is a film for preventing cracks and scratches on the main surface or end of the polarizer (22). Here, the " protective film " refers to a film directly laminated through an adhesive, among films that can be laminated in various ways on the polarizer 22.

The protective film 3 can be composed of various transparent resin films known in the field of polarizing plate. Examples thereof include cellulose resins typified by triacetylcellulose, polyolefin-based resins exemplified by polypropylene-based resins, cyclic olefin-based resins exemplified by norbornene-based resins, and polymethylmethacrylate-based resins Acrylic resin, polyethylene terephthalate resin, polyester resin, and the like. Among them, a cellulose-based resin is typical.

The protective film 3 may be a film having no optical function or a film having an optical function such as a retardation film or a brightness enhancement film.

The thickness of the protective film 3 is preferably 5 to 90 탆, more preferably 5 to 80 탆, and still more preferably 5 to 50 탆.

As the adhesive forming the adhesive layer 5, various adhesives conventionally used in the production of a polarizing plate can be used. For example, from the viewpoints of weatherability, refractive index, cationic polymerizability, etc., an epoxy resin which does not contain aromatic rings in the molecule is preferable. Further, it is preferable to cure by irradiation with an active energy ray (ultraviolet ray or heat ray).

As the epoxy resin, for example, a hydrogenated epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin and the like are preferable. (For example, a photo cationic polymerization initiator for polymerizing by irradiation with ultraviolet rays, a thermal cationic polymerization initiator for polymerizing by irradiation of heat rays) and other additives (sensitizers, etc.) are further added to the epoxy resin to prepare an epoxy A resin composition may be prepared and used.

As the adhesive, an acrylic resin such as acrylamide, acrylate, urethane acrylate, or epoxy acrylate, or a polyvinyl alcohol-based water-based adhesive may be used.

The polarizing plate 10 is adhered to one or both surfaces of a display cell (image display device) such as a liquid crystal cell. The polarizing plate may further include another optical layer laminated on the protective film. As another optical layer, there are a reflective polarizing film that transmits a certain kind of polarized light and reflects polarized light exhibiting properties opposite to that of the polarized light; A film having an antireflection function on the surface and having an antiglare function; A film having a surface antireflection function; A reflecting film having a reflecting function on the surface; A transflective film having a reflection function and a transmission function; And a viewing angle compensation film.

The thickness of the polarizing plate 10 composed of two layers of the polarizer 22 and the protective film 3 is preferably 10 to 500 占 퐉, more preferably 10 to 300 占 퐉, still more preferably 10 to 200 占 퐉 Do.

The protective film 6 is a film for preventing the adhesive from adhering to the bonding roll, and also the surface of the member (here, the first optical film 2) in which the protective film 6 is laminated is damaged, And the like. As the material of the protective film 6, the same material as the protective film can be used, and among these, a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, polyethylene isophthalate, polybutylene terephthalate and the like is preferable.

The guard film 6 may have a pressure-sensitive adhesive layer laminated on the surface of the film in addition to the film serving as the base material and having weak adhesion.

The thickness of the protective film 6 is preferably 5 to 200 占 퐉, more preferably 5 to 100 占 퐉, and still more preferably 5 to 50 占 퐉.

(Production method of laminated optical film)

2 and 3, the laminated optical film 1A is produced by laminating the first optical film 2 and the adhesive layer 5 between a pair of rotating bonding rolls 7a and 7b, And the protective film 3 are arranged in this order in the direction of connecting the pair of bonding rolls 7a and 7b to bond the first optical film 2 and the protective film 3 . At this time, the protective film 6 is sandwiched between the bonding roll 7a on the first optical film 2 side and the first optical film 2.

Here, the polarizer 22 in the first optical film 2 is coated on the resin base material 21, dried and then subjected to a stretching treatment for each resin base material 21, and dyeing with iodine or dichromatic dye and boric acid treatment And the end portions in the width direction are cut off so that the widths of the resin base material 21 and the polarizer 22 are equal to each other and both end portions are aligned so as to supply the adhesive layer 5 to the protective film 3). In Fig. 2, the illustration of the adhesive layer 5 is omitted.

The first optical film 2, the protective film 3 and the guard film 6 are laminated to form a laminate 4A. The laminate 4A is then cured by the adhesive layer 5, 1 as the laminated optical film 1A shown in Fig.

The presence of each member at the time of bonding will be described. As shown in Fig. 3, the width of each film or adhesive layer 5 between the pair of bonding rolls 7a, 7b satisfies the following relationship. In Fig. 3, the joining rolls 7a and 7b are separated from the laminate 4A in order to make the drawing easier to see.

, Width (W _A) of the adhesive layer 5 is not less than the width (W ₁₎ of the first optical film _{(2). (W A ≥W} 1)

The position of the first optical film 2 in the width direction lies within the existence width W _A of the adhesive layer 5.

The width W ₂ of the protective film 3 is larger than the width W _A of the adhesive layer 5 (W ₂ > W _A )

The protective film 3 is positioned so as to enclose the existence width W _A of the adhesive layer 5.

The width W ₃ of the guard film 6 is larger than the width W _A of the adhesive layer 5 (W ₃ > W _A )

The protective film 6 is interposed so as to contain the existence width W _A of the adhesive layer 5.

The term " nested " as used herein means that both ends of a member on a wide side are positioned on the outside in a width direction than both ends of a member on a narrow side.

The relationship between the width of the protective film 3 and the width of the guard film 6 is arbitrary.

The manufacturing method of the first embodiment is not an essential requirement, but satisfies the following relationships.

· A first width of the optical film (2) side bonding roll (7a) of the (W _R1) is smaller than the width (W ₃₎ of the Gabor call film _{(6). (W 3>} W R1)

, Within the first optical film (2) side bonding roll (7a) there is a width in the width direction of the arc positions go film 6 of (W _3).

The width W _R2 of the bonding roll 7b on the protective film 3 side is larger than the width W _A of the adhesive layer 5. (W _R2 > W _A )

The bonding roll 7b on the side of the protective film 3 is positioned such that the position in the width direction contains the existence width W _A of the adhesive layer 5.

Width (W _R2), the protective film 3 side bonding roll (7b) is greater than the width (W ₂₎ of the protective film (3). (W _R2> W ₂₎

· Protective film 3 bonding roll (7b) of the side is positioned in the width direction are positioned so as to pose a present width (W ₂₎ of the protective film 3.

Here, the " width of the joining roll " means the entire width of a portion that becomes an effective contact surface contributing to bonding and extends while maintaining the same diameter. For example, in the case where a portion of the end portions of the bonding rolls 7a and 7b in the width direction is reduced in diameter and does not contact the first optical film 2 or the protective film 3, And the width of the portion excluding the entire width of the bonding rolls 7a and 7b.

The width of the first optical film (2) side bonding roll (7a) of the (W _R1) is the width of the adhesive layer 5, the width (W _A) is less than desirable, and the first optical film (2) of (W ₁ ) Is more preferable.

The width W _R1 of the bonding roll 7a is preferably 1 to 100 mm smaller than the width W ₃ of the third optical film 6 and more preferably 1 to 50 mm smaller.

According to this manufacturing method, when the first optical film 2 and the protective film 3 are bonded to each other, the adhesive layer 5 and the bonding rolls 7a and 7b are wider than the adhesive layer 5 Since the protective film 3 or the guard film 6 is interposed, it is possible to prevent the bonding rolls 7a and 7b from being dirty by the adhesive.

The width W _R1 of the bonding roll 7a on the first optical film 2 side is smaller than the width W ₃ of the guard film 6, Since the position in the width direction of the joining roll 7a on the side of the joining film ₂ is within the existence width W3 of the protective film 6, the joining roll 7a is further prevented from being dirty by the adhesive.

Since the resin base material 21 and the polarizer 22 constituting the first optical film 2 are equal in width to each other and have both ends aligned with each other, The thickness is stable.

In addition, since the width (W _A), the width (W ₁₎ over _(A ≥W W ₁₎ of the first optical film (2) of the adhesive layer 5, the peeling of the resin substrate 21 from the polarizer 22 The polarizer 22 is prevented from tearing.

Although the width W _R2 of the bonding roll 7b on the protective film 3 side is larger than the width W2 of the protective film 3 in the _first embodiment, the width is smaller than the width may be (W ₂₎ of the protective film 3. In this case, the joining roll 7b is positioned within the existence width W ₂ of the protective film 3. According to this, it is further prevented that the bonding roll 7b is dirty by the adhesive.

≪ Second Embodiment >

Hereinafter, a second embodiment of the present invention will be described. The difference from the first embodiment will be mainly described.

(Laminated optical film)

As shown in Fig. 4, the laminated optical film 1B produced by the method for producing a laminated optical film of the second embodiment does not have the third optical film 6. [

(Production method of laminated optical film)

5 and 6, the laminated optical film 1B is produced by laminating the first optical film 2 and the adhesive layer 5 between a rotating pair of bonding rolls 7a and 7b, And the protective film 3 are arranged in this order in the direction of connecting the pair of bonding rolls 7a and 7b to bond the first optical film 2 and the protective film 3 .

The first optical film 2 and the protective film 3 are laminated to form a laminate 4B and the laminate 4B is then cured by the adhesive layer 5 to form a laminated optical film 1B).

The presence of each member at the time of bonding will be described. As shown in Fig. 6, the widths of the films, the adhesive layer 5 and the bonding rolls 7a between the pair of bonding rolls 7a and 7b satisfy the following relationship. In Fig. 6, the bonding rolls 7a and 7b are separated from the laminate 4B for easy viewing.

, Width (W _A) of the adhesive layer 5 is not less than the width (W ₁₎ of the first optical film _{(2). (W A ≥W} 1)

The position of the first optical film 2 in the width direction lies within the existence width W _A of the adhesive layer 5.

The width W ₂ of the protective film 3 is larger than the width W _A of the adhesive layer 5 (W ₂ > W _A )

The protective film 3 is positioned so as to enclose the existence width W _A of the adhesive layer 5.

The width W _R1 of the bonding roll 7a on the first optical film 2 side is smaller than the width W ₁ of the first optical film 2 (W ₁ > W _R1 )

The position of the bonding roll 7a on the side of the first optical film 2 in the width direction is within the existence width W ₁ of the first optical film 2.

The width W _R1 of the bonding roll 7a on the first optical film 2 side is preferably _{1 to} 200 mm smaller than the width W ₁ of the first optical film 2, Small is more preferable.

Further, the manufacturing method of the second embodiment is not an essential requirement, but satisfies the following relationships.

The width W _R2 of the bonding roll 7b on the protective film 3 side is larger than the width W _A of the adhesive layer 5. (W _R2 > W _A )

The bonding roll 7b on the side of the protective film 3 is positioned so that the widthwise position thereof includes the existence width W _A of the adhesive layer 5.

Width (W _R2), the protective film 3 side bonding roll (7b) is greater than the width (W ₂₎ of the protective film (3). (W _R2> W ₂₎

· Protective film 3 bonding roll (7b) of the side is positioned in the width direction are positioned so as to pose a present width (W ₂₎ of the protective film 3.

According to this manufacturing method, the width W _R1 of the bonding roll 7a on the first optical film 2 side is larger than the width W _R1 of the second optical film 2, while the adhesive layer 5 comes out of the width of the first optical film 2, Is smaller than the width W _{1 of} the first optical film 2 and the position of the bonding roll 7a on the first optical film 2 side is the width of the first optical film 2 W ₁ , the bonding roll 7a is prevented from being dirty by the adhesive.

In addition, the second embodiment, although the large aspect than the width (W ₂₎ of the protective film 3 side bonding roll (7b), the width (W _R2), a protective film 3 of, bonding roll (7b) It is good also to the width (W _R2) smaller than the width (W ₂₎ of the protective film 3, the same as those of the first embodiment.

≪ Third Embodiment >

Hereinafter, a third embodiment of the present invention will be described. The differences from the second embodiment will mainly be described.

(Laminated optical film)

As shown in Fig. 7, in the laminated optical film 1C produced according to the method for producing a laminated optical film of the third embodiment, the width of the first optical film 2 is larger than the width of the adhesive layer 5 .

The relationship between the widths of the first optical film 2, the protective film 3 and the adhesive layer 5 and the positional relationship therebetween will be described later. Roughly arranged. That is, in the cross-sectional view shown in Fig. 7, the lamination mode is substantially symmetrical.

(Production method of laminated optical film)

As shown in Figs. 5 and 8, the laminated optical film 1C is produced by laminating the first optical film 2 and the adhesive layer 5 between a pair of rotating bonding rolls 7a and 7b, And the protective film 3 are arranged in this order in the direction of connecting the pair of bonding rolls 7a and 7b to bond the first optical film 2 and the protective film 3 .

The first optical film 2 and the protective film 3 are laminated to form a laminate 4C and the laminate 4C is then cured to form a laminated optical film 1C).

The presence of each member at the time of bonding will be described. As shown in Fig. 8, the width of each film or adhesive layer 5 between the pair of bonding rolls 7a, 7b satisfies the following relationship. In Fig. 8, the bonding rolls 7a and 7b are separated from the laminate 4C in order to make the drawing easier to see.

The width W _A of the adhesive layer 5 is less than the width W ₁ of the first optical film 2. (W ₁ > W _A )

The position of the adhesive layer 5 in the width direction is within the existence width W ₁ of the first optical film 2.

The width W ₂ of the protective film 3 is larger than the width W _A of the adhesive layer 5 (W ₂ > W _A )

The protective film 3 is positioned so as to enclose the existence width W _A of the adhesive layer 5.

Here, the width W _A of the adhesive layer 5 is preferably 0.1 to 50 mm smaller than the width W ₁ of the first optical film 2, more preferably 0.1 to 20 mm, Mm is more preferable. In this case, the first optical film (2) and the protective film (3) can be sufficiently adhered to the ends in the width direction.

In addition, the first magnitude relationship between the width (W ₂₎ of the optical film (2), the width (W ₁₎ and a protective film 3 may be any of, but in this case has to be the same. (W ₁ = W ₂₎

The manufacturing method of the third embodiment is not an essential requirement, but satisfies the following relationships.

The widths W _R1 and W _R2 of the bonding rolls 7a and 7b are larger than the width W ₁ of the first optical film 2 and the width W ₂ of the protective film 3. W _R1> W _1, also, W _R2> W ₂₎

, Both bonding rolls (7a, 7b) is of the width-direction position, respectively, positioned to imply the existence range of the first optical film (2) (W ₁₎ and the second presence of the optical film (3) the width (W ₂₎ have.

The relationship between the widths of the both bonding rolls 7a and 7b is arbitrary, but is assumed to be the same here. (W _R1 = W _R2 )

According to this manufacturing method, since the possibility that the adhesive layer 5 is released from the width of the first optical film 2 and the protective film 3 is very small, the dirt of the bonding rolls 7a and 7b Can be prevented.

In the third embodiment, the widths W _R1 and W _R2 of the bonding rolls 7a and 7b are respectively equal to the width W ₁ of the first optical film 2 and the width W ₂ of the protective film 3 The width of the bonding rolls 7a and 7b may be smaller than the width W ₁ of the first optical film 2 and the width W ₂ of the protective film 3, May be smaller than the width (W _A ) of the wirings (5). In this case, the bonding rolls 7a and 7b are respectively positioned within the existence width W ₁ of the first optical film 2 and the existence width W ₂ of the protective film 3. According to this, it is further prevented that the bonding rolls 7a and 7b are dirty by the adhesive.

Although the adhesive layer 5 is provided by coating the protective film 3 in the same manner as in the first embodiment in the third embodiment, the adhesive layer 5 may be coated on the polarizer 22 side good.

(Modifications of First to Third Embodiments)

The first to third embodiments may be implemented as the following embodiments. In other words, when the first optical film 2 is a polarizing plate (e.g., a polarizing plate having the configuration of the polarizing plate 10 shown in Fig. 1) and the second optical film 3 is a separator, Or the like. In this case, a polarizing plate having a separator is produced as a laminated optical film. Hereinafter, this aspect will be described.

The pressure-sensitive adhesive layer is a layer that functions when a polarizing plate is adhered to another article (for example, a liquid crystal cell). The pressure-sensitive adhesive layer can be composed of acrylic resin, silicone resin, polyester, polyurethane, polyether, or the like.

The thickness of the pressure-sensitive adhesive layer is preferably 2 to 500 占 퐉, more preferably 2 to 200 占 퐉, and still more preferably 2 to 50 占 퐉.

As a method of laminating the pressure-sensitive adhesive layer on the polarizing plate, for example, a method of applying a solution containing the above resin or an arbitrary additive component to the polarizing plate, or a method of forming a pressure-sensitive adhesive layer with the solution on the separator and then laminating the pressure- good.

The separator is a peelable film which is adhered to the surface of the pressure-sensitive adhesive layer for the purpose of protecting the pressure-sensitive adhesive layer or preventing foreign matter from adhering thereto. The separator is peeled off when the polarizing plate is used to expose the pressure- The separator may be made of, for example, a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, or a polyester-based resin such as polyethylene terephthalate. Among them, a stretched film of polyethylene terephthalate is preferable.

The separator may be subjected to a releasing treatment with a silicone resin or the like on the surface in contact with the pressure-sensitive adhesive layer so that the separator can be easily peeled off when the polarizing plate is used.

The thickness of the separator is preferably 10 to 500 mu m, more preferably 10 to 300 mu m, and further preferably 10 to 200 mu m.

Even in the above-described mode, dirt of the bonding rolls 7a and 7b by the pressure-sensitive adhesive can be prevented by the same action as in the above embodiment.

When a polarizing plate is used as the first optical film 2, a protective film is usually laminated on one or both sides of the polarizer through an adhesive. In the case of a polarizing plate in which a protective film is laminated on only one side of a polarizer, the side opposite to the side where the protective film is laminated may be laminated so as to be on the side of the adhesive layer. The polarizing plate may further include another optical layer laminated on the protective film or a protective layer for protecting the surface of the protective film. As another optical layer, there are a reflective polarizing film that transmits a certain kind of polarized light and reflects polarized light exhibiting properties opposite to that of the polarized light; A film having an antireflection function on the surface and having an antiglare function; A film having a surface antireflection function; A reflecting film having a reflecting function on the surface; A transflective film having a reflection function and a transmission function; And a viewing angle compensation film. As the protective layer for protecting the surface of the protective film, a general transparent resin film can be used. Examples thereof include cellulose resins typified by triacetylcellulose, polyolefin-based resins exemplified by polypropylene-based resins, cyclic olefin-based resins exemplified by norbornene-based resins, and polymethylmethacrylate-based resins Acrylic resin, polyethylene terephthalate resin, polyester resin, and the like. The protective layer for protecting the surface of the protective film may be a film having no optical function or a film having an optical function such as a retardation film or a brightness enhancement film.

≪ Fourth Embodiment &

Hereinafter, a fourth embodiment of the present invention will be described. The differences from the second embodiment will mainly be described.

(Laminated optical film)

9, the laminated optical film 1D produced by the method for producing a laminated optical film of the fourth embodiment is a laminated optical film obtained by laminating the resin base material 21 and the polarizer 22 in the first optical film 2, The width of the resin base material 21 is larger than the width of the polarizer 22.

The relationship between the widths of the resin substrate 21, the polarizer 22, the protective film 3 and the adhesive layer 5 and the positional relationship therebetween will be described later. The axes are roughly arranged. That is, in the cross-sectional view shown in Fig. 9, the lamination mode is substantially symmetrical.

(Production method of laminated optical film)

As shown in Figs. 5 and 10, the laminated optical film 1D includes a resin base material 21, a polarizer 22, an adhesive agent (binder) The layer 5 and the protective film 3 are introduced while being arranged in this order in the connecting direction between the pair of bonding rolls 7a and 7b so that the polarizer 22 and the protective film 3 are bonded do.

Here, the polarizer 22 in the first optical film 2 is coated only in the widthwise central portion of the resin base material 21, and both ends are uncoated, followed by drying, Followed by dyeing with iodine or a dichroic dye and treatment with boric acid, followed by washing with water and drying.

The resin substrate 21, the polarizer 22 and the protective film 3 are laminated to form a laminate 4D. The laminate 4D is then cured by the adhesive layer 5, And is completed as the optical film 1D.

The presence of each member at the time of bonding will be described. As shown in Fig. 10, the width of each film or adhesive layer 5 between the pair of bonding rolls 7a and 7b satisfies the following relationship. In Fig. 10, the bonding rolls 7a and 7b are separated from the laminate 4D in order to make the drawing easier to see.

The width W ₁₂ of the polarizer 22 is smaller than the width W ₁₁ of the resin base material 21 (W ₁₁ > W ₁₂ )

The width W _A of the adhesive layer 5 is equal to or larger than the width W ₁₂ of the polarizer 22 and smaller than the width W ₁₁ of the resin base material 21 (W ₁₁ > W _A ? W ₁₂ )

The resin base material 21 is positioned so as to contain the existence width W ₁₂ of the polarizer 22 and the existence width W _A of the adhesive layer 5.

The width W ₂ of the protective film 3 is larger than the width W _A of the adhesive layer 5 (W ₂ > W _A )

The protective film 3 is positioned so as to enclose the existence width W _A of the adhesive layer 5.

Further, the magnitude relation of the width (W ₂₎ of the width (W ₁₂₎ and a protective film 3 of the resin base 21 is arbitrary.

The manufacturing method of the fourth embodiment is not an essential requirement, but satisfies the following relationships.

The width W _R1 of the bonding roll 7a on the resin base material 21 side is smaller than the width W ₁₁ of the resin base material 21 (W ₁₁ > W _R1 )

The position of the bonding roll 7a on the side of the resin base material 21 in the width direction lies within the existing width of the resin base material 21. [

Width (W _R2), the protective film 3 side bonding roll (7b) is greater than the width (W ₂₎ of the protective film (3). (W _R2> W ₂₎

· Protective film 3 bonding roll (7b) of the side is positioned in the width direction are positioned so as to pose a present width (W ₂₎ of the protective film 3.

The width W _R1 of the bonding roll 7a on the resin base material 21 side is preferably smaller than the width W _A of the adhesive layer 5 and smaller than the width W ₁₂ of the polarizer 22 Is more preferable. The width W _R1 of the bonding roll 7a is preferably 1 to 100 mm smaller than the width W ₁₁ of the resin base 21 and more preferably 1 to 50 mm smaller.

According to this manufacturing method, when the polarizer 22 and the protective film 3 are bonded to each other, a resin base material (base material) 5 having a wider width than the adhesive layer 5 is provided between the adhesive layer 5 and the bonding rolls 7a, 21 or the protective film 3 interposed therebetween, it is possible to prevent the bonding rolls 7a, 7b from being dirty by the adhesive.

The width W _R1 of the bonding roll 7a on the resin base material 21 side is smaller than the width of the resin base material 21 and the width W _R1 of the bonding roll 7a on the resin base material 21 side ) it is because in the present width (W ₁₁₎ of the width direction position of the resin substrate 21, a bonding roll (7a) is prevented from further a spotted by adhesive.

In the fourth embodiment, the first optical film 2 may be a polarizing plate. As the polarizing plate, a protective film may be laminated on one or both sides of the polarizer through an adhesive. The polarizer may be smaller than the width of the protective film and exist within the width of the protective film. In the case of a polarizing plate in which a protective film is laminated on only one side of a polarizer, the side opposite to the side where the protective film is laminated may be laminated so as to be on the side of the adhesive layer. The polarizing plate may further include another optical layer laminated on the protective film or a protective layer for protecting the surface of the protective film. As another optical layer, there are a reflective polarizing film that transmits a certain kind of polarized light and reflects polarized light exhibiting properties opposite to that of the polarized light; A film having an antireflection function on the surface and having an antiglare function; A film having a surface antireflection function; A reflecting film having a reflecting function on the surface; A transflective film having a reflection function and a transmission function; And a viewing angle compensation film. As the protective layer for protecting the surface of the protective film, a general transparent resin film can be used. Examples thereof include cellulose resins typified by triacetylcellulose, polyolefin-based resins exemplified by polypropylene-based resins, cyclic olefin-based resins exemplified by norbornene-based resins, and polymethylmethacrylate-based resins Acrylic resin, polyethylene terephthalate resin, polyester resin, and the like. The protective layer for protecting the surface of the protective film may be a film having no optical function or a film having an optical function such as a retardation film or a brightness enhancement film.

While the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all.

For example, in each of the above embodiments, the polarizer 22 is coated on one side of the resin base material 21, but the polarizer 22 may be coated on both sides of the resin base material 21. In this case, after the laminated optical films 1A to 1D are manufactured, the polarizer 22 facing the adhesive layer 5 is peeled off from the resin base material 21, whereby the polarizer 22 remaining on the resin base material 21 side Can be used for the production of a separate polarizing plate.

In the above embodiments, the example of the first optical film provided with the polarizer 22 on one side of the resin base material 21 has been described. However, it is also possible to use the first optical film provided on one side or both sides of the resin base material 21 separately from the polarizer 22 An optical function layer of the above-described structure may be provided. Examples of the optical function layer other than the polarizer 22 include a retardation layer and a viewing angle compensation layer. A liquid obtained by dissolving or dispersing a material having a desired optical function is coated on the resin base material 21, Layer can be provided.

1A-1D ... Laminated optical film, 2 ... The first optical film, 3 ... A protective film (second optical film), 4A to 4D, The laminate, 5 ... Adhesive layer, 6 ... Gabor film (third optical film), 7a ... A bonding roll on the first optical film side, 7b ... The bonding roll on the protective film side, 10 ... Polarizer, 21 ... Resin substrate, 22 ... Polarizer, W ₁ ... The width of the first optical film, W ₁₁ ... Width of resin base material, W ₁₂ ... The width of the polarizer, W ₂ ... Width of protective film, W ₃ ... Gabor arc width of the film, W ... _A Width of adhesive layer, W _R1 ... The width of the bonding roll on the first optical film side, W _R2 ... Width of the bonding roll on the protective film side.

Claims (13)

A first optical film, an adhesive layer or a pressure-sensitive adhesive layer, and a second optical film are introduced between a pair of rotating rotating rolls in the order of connecting the pair of rolls in this order, 1. A method for producing a laminated optical film, which comprises bonding an optical film and a second optical film,
At the time of bonding,
Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer is not less than the width of the first optical film,
The position of the first optical film in the width direction is within the existing width of the adhesive layer or the pressure-sensitive adhesive layer,
The width of the second optical film is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer,
The second optical film is positioned so as to contain the width of the adhesive layer or the pressure-sensitive adhesive layer,
A third optical film having a width larger than the width of the adhesive layer or the pressure-sensitive adhesive layer is provided between the bonding roll on the first optical film side and the first optical film, and the width of the adhesive layer or the pressure- To form a laminated optical film. The optical film according to claim 1, wherein a width of the bonding roll on the first optical film side is smaller than a width of the third optical film,
And the position of the bonding roll on the first optical film side in the width direction is within the existing width of the third optical film. A first optical film, an adhesive layer or a pressure-sensitive adhesive layer, and a second optical film are introduced between a pair of rotating rotating rolls in the order of connecting the pair of rolls in this order, 1. A method for producing a laminated optical film, which comprises bonding an optical film and a second optical film,
At the time of bonding,
Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer is not less than the width of the first optical film,
The position of the first optical film in the width direction is within the existing width of the adhesive layer or the pressure-sensitive adhesive layer,
The width of the second optical film is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer,
The second optical film is positioned so as to contain the width of the adhesive layer or the pressure-sensitive adhesive layer,
The width of the bonding roll on the first optical film side is smaller than the width of the first optical film,
And the position of the bonding roll on the first optical film side in the width direction is within the existing width of the first optical film. A first optical film, an adhesive layer or a pressure-sensitive adhesive layer, and a second optical film are introduced between a pair of rotating rotating rolls in the order of connecting the pair of rolls in this order, 1. A method for producing a laminated optical film, which comprises bonding an optical film and a second optical film,
At the time of bonding,
Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer is less than the width of the first optical film,
Wherein the adhesive layer or the pressure-sensitive adhesive layer has a widthwise position within an existing width of the first optical film,
The width of the second optical film is larger than the width of the adhesive layer or the pressure-sensitive adhesive layer,
Wherein the second optical film is positioned so as to contain the width of the adhesive layer or the pressure-sensitive adhesive layer. The optical film according to claim 4, wherein the width of the bonding roll on the first optical film side is smaller than the width of the first optical film,
And the position of the bonding roll on the first optical film side in the width direction is within the existing width of the first optical film. The method of producing a laminated optical film according to claim 4 or 5, wherein the width of the adhesive layer or the pressure-sensitive adhesive layer is 0.1 to 50 mm smaller than the width of the first optical film. The optical element according to any one of claims 1 to 6, wherein the first optical film has a resin base material and an optical functional layer provided on one or both surfaces of the resin base material,
Wherein the resin base material and the optical function layer have the same width and are arranged at both ends,
The first optical film is disposed such that the optical function layer side faces the adhesive layer or the pressure-sensitive adhesive layer side,
And the second optical film is a protective film. 8. The method of producing a laminated optical film according to claim 7, wherein the optically functional layer is a polarizer. The method of producing a laminated optical film according to claim 8, wherein the polarizer is coated on the resin base material. And a protective film are laminated between a rotating pair of bonding rolls in such a manner that a resin substrate, an optical functional layer provided on one side or both sides of the resin substrate, an adhesive layer or a pressure sensitive adhesive layer, In which the optical functional layer and the protective film are bonded to each other,
At the time of bonding,
The width of the optical function layer is smaller than the width of the resin substrate,
Wherein the width of the adhesive layer or the pressure-sensitive adhesive layer is larger than the width of the optical functional layer, is smaller than the width of the resin substrate,
Wherein the resin substrate is positioned so as to contain the width of the optical function layer and the adhesive layer or the pressure-sensitive adhesive layer,
Wherein the width of the protective film is larger than the width of the adhesive layer or the pressure-
Wherein the protective film is positioned so as to contain the width of the adhesive layer or the pressure-sensitive adhesive layer. The method according to claim 10, wherein the width of the bonding roll on the resin substrate side is smaller than the width of the resin substrate,
And the position of the bonding roll on the side of the resin substrate in the width direction is within the existing width of the resin substrate. The method for producing a laminated optical film according to claim 10 or 11, wherein the optically functional layer is a polarizer. The method for producing a laminated optical film according to claim 12, wherein the polarizer is coated on the resin base material.

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