TWI791107B - Laminate - Google Patents

Abstract

An object of the present invention is to provide a laminate having a notch in which peeling failure of a release film does not occur when the release film is started to be peeled from an edge having a notch portion.

In the laminate for solving the object, a surface protection film is laminated on one side of a polarizing plate, a release film is laminated on the other side of the polarizing plate, and the polarizing plate contains a polarizer, wherein the laminate has a notch part in planar view, and the maximum value of peel force is 1.0 N or less when the release film is peeled from the edge having the notched portion.

Description

laminate

The present invention relates to laminates.

Polarizers are widely used in image display devices such as liquid crystal display devices and organic electroluminescent (EL) display devices, especially in various portable devices such as smart phones in recent years. Conventionally, polarizers have been used in which dichroic dyes are adsorbed and aligned on a polyvinyl alcohol-based resin film, and a protective film is attached to one or both sides of the polarizer.

Polarizers are generally circulated in the market in the form of laminates. The laminated system is pasted on the surface to prevent its surface from being dirty or scratched. Also known as the separation membrane).

When attaching a polarizing plate to a display element such as a liquid crystal cell or an organic EL element, peel off the release film attached to the surface, and attach the polarizing plate to the display element through the exposed adhesive layer. When peeling off the release film, the surface protection film side of the laminate (a film with a surface protection film layered on one side of the polarizing plate and a release film layered on the other side) is fixed on the holding table by suction, adsorption, etc., and the The release tape is pasted on the release film. Thereafter, the release tape was pulled up and the release film was removed from the surface of the polarizing plate.

According to the design of the image display device, the laminated body is often processed into a shape other than a rectangular shape. Specifically, in the laminated system, hole processing is performed in the plane, corners are subjected to R processing in plan view, or notch processing is performed in plan view. In particular, when the laminate is notched in a plan view, if the peeling film is peeled from the edge having the notch, the peeling film cannot be peeled off when the peeling tip reaches the notch. With the movement of the release film, the originally fixed polarizer and surface protection film will be lifted from the holding table, so that the fixation of the polarizer and surface protection film will be released, and the release film cannot be easily peeled off.

This problem can be solved by increasing the force such as suction force or adsorption force when fixing the laminated body, or reducing the adhesive force of the release film, but on the other hand, new problems will arise. That is, if the force acting on the laminated body such as suction force or adsorption force increases, traces will remain on the polarizing plate to deteriorate the appearance. Moreover, when the adhesive force of a release film becomes small, when impact is given to a laminated body during conveyance etc., a gap will be formed between a release film and a polarizing plate.

[Prior Art Literature] [Patent Document]

Patent Document 1: WO2018/016285A1.

The object of this invention is to provide the laminated body which does not generate|occur|produce the peeling defect of a peeling film.

[1] A laminate comprising a surface protective film layered on one surface of a polarizing plate, a peeling film layered on the other surface of the polarizing plate, and the polarizing plate comprising a polarizer, wherein the laminate has a notch in plan view, When peeling the said peeling film from the edge which has the said notch part, the maximum value of peeling force is 1.0N or less.

[2] The laminate described in [1], wherein the shape of the notch satisfies the following formula (1).

r>3d-14 (1)

[In the formula (1), d (mm) represents the depth of the aforementioned notch, and r (mm) represents the radius of curvature of the inner corner of the aforementioned notch. ]

[3] The laminate described in [1] or [2], wherein the polarizing plate is provided with an adhesive layer on the surface of the release film side, and the adhesive force between the release film and the adhesive layer is 0.02N/25mm Above 0.10N/25mm below.

[4] A method of manufacturing a polarizing plate with a surface protection film, comprising the following steps: attaching The sticking step of the adhesive tape; and the peeling step of pulling up the aforementioned adhesive tape and peeling off the peeling film from the laminate, wherein, in the aforementioned peeling step, the angle between the peeling direction of the adhesive tape and the end edge orthogonal to the end edge having the notch Not less than 25° and not more than 65°.

According to the present invention, it is possible to provide a laminate in which a peeling defect of a peeling film does not occur.

10‧‧‧polarizer

11‧‧‧Polarizer

12, 13‧‧‧Protective film

14‧‧‧retardation film

15‧‧‧adhesive layer

16‧‧‧adhesion layer

17‧‧‧Brightness enhancement film

20‧‧‧Peeling film

30‧‧‧Surface protection film

31‧‧‧Substrate film

32‧‧‧adhesive layer

40‧‧‧Notch

100, 101, 102, 103, 104‧‧‧laminated body

200‧‧‧Peel Tape

300‧‧‧area

400‧‧‧Peeling direction

The schematic cross-sectional view in Fig. 1 shows an example of the layer configuration of the laminate of the present invention.

The schematic cross-sectional view in Fig. 2 shows an example of the layered structure of the laminated body of the present invention.

The schematic plan view of FIG. 3 shows an example of the notch part which the laminated body of this invention has.

The schematic plan view of FIG. 4 shows an example of the notch part which the laminated body of this invention has.

The schematic plan view of Fig. 5 shows an example of a method of peeling off a release film from a laminate.

<laminate>

The laminate system has a surface protective film on one side of the polarizer, and a release film on the other side of the polarizer. The polarizing plate has at least a polarizer. An example of the layer configuration of the laminate of the present invention will be described below with reference to the drawings. In addition to the polarizer, the polarizing plate may include a protective film, a retardation film, a brightness enhancement film, an adhesive layer, and the like.

The schematic sectional view of Fig. 1 shows an example of the laminated body of the present invention. The laminate 100 shown in FIG. 1(a) is composed of a polarizer 10 , a surface protection film 30 laminated on one side of the polarizer 10 , and a release film 20 laminated on the other side of the polarizer 10 . The layer composition of the polarizing plate 10 is as follows: on one side of the polarizing plate 11, the protective film 12 is laminated through the adhesive not shown in the intermediary, on the other side, the retardation film 14 is laminated through the adhesive layer 16, and on the retardation film 14 The adhesive layer 15 is laminated.

The laminate 101 shown in FIG. 1( b ) is composed of a polarizer 10 , a surface protection film 30 laminated on one side of the polarizer 10 , and a release film 20 laminated on the other side of the polarizer 10 . The layer composition of the polarizing plate 10 is as follows: on one side of the polarizing plate 11, an adhesive laminated protective film 12 not shown in the illustration is passed through, and on the other side, an adhesive laminated protective film 13 not shown in the illustration is passed through the protective film. A retardation film 14 is laminated on the substrate 13 via an adhesive layer 16 , and an adhesive layer 15 is laminated on the retardation film 14 .

The laminate 102 shown in FIG. 2 (a) is composed of a polarizer 10 , a surface protection film 30 laminated on one side of the polarizer 10 , and a release film 20 laminated on the other side of the polarizer 10 . The layer composition of the polarizer 10 is as follows: on one side of the polarizer 11, a protective film 13 is laminated via an adhesive not shown in the intermediary, and on the other side, a brightening film 17 is laminated via an adhesive layer 16, and the protective film 13 is laminated and adhered. agent layer 15.

The laminate 103 shown in FIG. 2 (b) is composed of a polarizer 10 , a surface protection film 30 laminated on one side of the polarizer 10 , and a release film 20 laminated on the other side of the polarizer 10 . The layer composition of the polarizing plate 10 is as follows: on one side of the polarizing plate 11, an adhesive laminated protective film 12 not shown in the illustration is passed through, and on the other side, an adhesive laminated protective film 13 not shown in the illustration is passed through the protective film. 12 is laminated with a brightness enhancing film 17 via an adhesive layer 16 , and an adhesive layer 15 is laminated on the protective film 13 .

In the laminates 100 to 103, the surface protection film 30 and the peeling film 20 are each preferably members constituting the outermost surface of the laminate. Laminates 100 to 103 , polarizing plate 10 , release film 20 , and surface protection film 30 may have layers other than those shown in the drawings.

It is preferable that the laminated body has a substantially rectangular main surface. The main surface refers to the surface having the largest area corresponding to the display surface. Substantially rectangular shape means that at least one of the four corners (corners) of the main surface of the laminate is obtuse or rounded, or perpendicular to the main surface. A part of the end surface has a concave portion (notch) that is depressed in the direction of the plane, or a part of the main surface has an opening that is pierced into a shape such as a circle, an ellipse, a polygon, or a combination thereof.

The laminated system has a notch on at least one end surface in plan view. As mentioned above, the notch is a part of the end surface perpendicular to the main surface in plan view, which is recessed in the in-plane direction. The laminate may have one or a plurality of notches. The laminate may have a plurality of notches on one end, but preferably one end has one notch. The notch can be formed on the edge perpendicular to or parallel to the absorption axis of the polarizer. The laminated system has a notch on the end surface in a plan view, so when the laminated body is viewed from the top, the end portion presents a shape of inward depression.

In the laminate of the present invention, when the peeling film is peeled from the edge having the notch, the maximum peeling force is 1.0 N or less. The maximum value of the peel force is preferably 0.8N or less. The maximum value of the peeling force may be 0.1N or more. As will be described later, the maximum value of the peeling force can be controlled by the shape of the notch or the like. The maximum value of the peeling force can be measured according to the method described in the examples described later. By using such a peeling force, peeling defects are less likely to occur.

It is preferable that the shape of the notch part with which the laminated body of this invention is equipped satisfies the following formula (1).

When the laminate has a plurality of notches, at least one of the notches may satisfy the formula (1), and all the notches may satisfy the formula (1). By making the shape of the notch part satisfy said Formula (1), the force required at the time of peeling off a peeling film can be reduced.

r>3d-14 (1)

[In the formula (1), d (mm) represents the depth of the aforementioned notch, and r (mm) represents the radius of curvature of the inner corner of the aforementioned notch. ]

Fig. 3 shows a schematic view of an example of the laminate 104 of the present invention viewed from above. This laminated body 104 has the notch part 40 in planar view seen from above. The notch 40 is in a shape concaved inward from the end. The depth of the notch is equivalent to the length of the double arrow d in Figure 3, which is the distance from the end edge to the deepest part of the recess. The radius of curvature of the inner corner of the notch corresponds to the radius of curvature of the corner indicated by the single arrow R in FIG. 3 . When the radii of curvature of the two inner corners are different, r represents the radius of curvature of the smaller one. The radii of curvature of the two inner corners are preferably the same as each other.

Both r and d are values greater than 0. Although not particularly limited, the upper limit of r may be 17 mm. Although not particularly limited, the upper limit of d may be 20 mm. d may be 10 mm or less or 7 mm or less.

When d is not less than 2 mm and not more than 5 mm, r is preferably not less than 2 mm. When d is more than 5 mm and not more than 6 mm, r is preferably not less than 8 mm. When d is more than 6 mm and less than 8 mm, r is preferably at least 13 mm. When d is 8 mm or more, r is preferably 17 mm or more.

The width of the notch may be not less than 5 mm and not more than 50 mm, preferably not less than 5 mm and not more than 20 mm. The width of the notch refers to the length parallel to the end edge and is the longest distance of the notch.

Specifically, the shape of the notch can be the shape shown in FIG. 4 . The schematic diagram of Fig. 4 shows an example of the notch 40 in the laminated body of the present invention in a top view, and the notch 40 can be a rectangular concave portion as shown in Fig. 4 (a) when viewed from above. Rounded corners are provided at the two inner and middle corners, or rounded corners are provided at the four corners of the rectangular recess as shown in Figure 4 (b). In addition, the notch may have a shape in which corners of trapezoidal recesses are rounded as shown in FIG. 4(c). As shown in Fig. 4(a) to (c), the notch may have a straight portion at the bottom, or as shown in Fig. 4(d), the notch may not have a straight portion at the bottom.

The laminated body can be obtained by manufacturing a strip-shaped laminated body from roll to roll while conveying each member constituting the laminated body separately and cutting it, or by separately preparing each member of a predetermined shape and stacking them sequentially And get.

When the laminate is rectangular (or substantially rectangular) having a long side and a short side, the length of the long side is preferably 35 to 5 cm, more preferably 25 to 10 cm, and the length of the short side is preferably 25 to 5 cm, more preferably 20 to 6cm. Peelability can be further improved by setting it as the magnitude|size of such a range.

Each member included in the laminate will be described below.

<Polarizer>

The polarizer 10 is a polarizing element including at least a polarizer, and usually further includes a thermoplastic resin film attached to one or both sides thereof. The thermoplastic resin film may be a protective film for protecting a polarizer, other films having optical functions, and the like. The thermoplastic resin film may have a resin layer laminated on its surface (for example, at least one optical layer selected from a hard coat layer, an antistatic layer, an antiglare layer, a light diffusion layer, an antireflection layer, a low refractive index layer, and an antifouling layer. layer). The thermoplastic resin film can be bonded to the polarizer via an adhesive layer. The surface protection film 30 may also be laminated on the surface of the resin layer.

When the laminate further contains a brightness enhancement film or a retardation film, the effect of the present invention becomes more remarkable. The rigidity of the polarizing plate including the brightness enhancement film etc. is low, and it is easy to produce a peeling defect.

According to the present invention, even when the laminate contains a brightness enhancing film or the like, occurrence of peeling defects can be reduced.

The thickness (μm) of the polarizing plate is usually 150 μm or less, and the effect of the present invention is more remarkable when the rigidity is lower and is 75 μm or less, or even 70 μm or less. The thickness of the polarizing plate 10 is preferably at least 30 μm, more preferably at least 50 μm.

(1) Polarizer

The polarizer constituting the polarizer 10 is an absorbing polarizer, which absorbs linearly polarized light whose vibration plane is parallel to the absorption axis of the polarizer and transmits linearly polarized light whose vibration plane is perpendicular to the absorption axis (parallel to the transmission axis). It can be suitably used as a polarizer in which a dichroic dye is adsorbed and aligned on a uniaxially stretched polyvinyl alcohol-based resin film. The polarizer can be produced, for example, by a method including: a step of uniaxially stretching a polyvinyl alcohol-based resin film; a step of dyeing the polyvinyl alcohol-based resin film with a dichroic dye, thereby adsorbing the dichroic dye ; a step of treating the polyvinyl alcohol-based resin film on which the dichroic pigment is adsorbed with a cross-linking solution such as boric acid aqueous solution; and a step of washing with water after the treatment with the cross-linking solution.

As the polyvinyl alcohol-based resin, a saponified polyvinyl acetate-based resin can be used. Examples of polyvinyl acetate-based resins include, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers thereof with other monomers copolymerizable with vinyl acetate, and the like. Examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having ammonium groups.

In this specification, "(meth)acrylic acid" means at least one selected from acrylic acid and methacrylic acid. The same applies to "(meth)acryl", "(meth)acrylate", etc.

The saponification degree of polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin can be modified, for example, polyvinyl formaldehyde or polyvinyl acetal modified with aldehydes can be used. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000. The average degree of polymerization of a polyvinyl alcohol-type resin can be calculated|required based on JISK6726.

Such a film made of polyvinyl alcohol-based resin is used as a base film of a polarizer (polarizer). The film-forming method of polyvinyl alcohol-type resin is not specifically limited, A well-known method can be used. The thickness of the polyvinyl alcohol-based embryo film is not particularly limited, but in order to make the thickness of the polarizer 15 μm or less, it is preferably 5 to 35 μm. More preferably, it is 20 μm or less.

The uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before dyeing of the dichroic dye, simultaneously with dyeing, or after dyeing. When performing uniaxial stretching after dyeing, this uniaxial stretching may be performed before or during crosslinking treatment. Also, uniaxial stretching may be performed in these plural steps.

For uniaxial extension, it can be extended to a single axis between rollers with different peripheral speeds, or it can be extended to a single axis with a hot roller. In addition, the uniaxial stretching may be dry stretching in which the film is stretched in the air, or wet stretching in which the polyvinyl alcohol-based resin film is swollen using a solvent or water. The elongation ratio is usually 3 to 8 times.

As a method of dyeing a polyvinyl alcohol-type resin film with a dichroic dye, for example, a method of immersing the film in an aqueous solution containing a dichroic dye can be employed. As a dichroic dye, iodine or a dichroic organic dye is used. Moreover, it is preferable that the polyvinyl-alcohol-type resin film is previously subjected to the immersion process in water before dyeing process.

The cross-linking treatment after dyeing with a dichroic dye is usually a method of immersing a dyed polyvinyl alcohol-based resin film in an aqueous solution containing boric acid. When using iodine as a dichroic dye, it is preferable that the boric acid-containing aqueous solution contains potassium iodide.

The thickness of the polarizer is usually 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less, and more preferably 10 μm or less. In particular, setting the thickness of the polarizer to 15 μm or less is advantageous for thinning the laminate. The thickness of the polarizer is usually 2 μm or more, and from the viewpoint of making the polarizer rigid, it is preferably 3 μm or more. As described in JP-A-2016-170368, the polarizer can be used, for example, on a cured film polymerized from a liquid crystal compound Middle-matching those with dichroic pigments. Dichroic pigments can be used that have absorption in the wavelength range of 380 to 800nm, preferably organic dyes. As a dichroic dye, an azo compound is mentioned, for example.

The liquid crystal compound is a liquid crystal compound that can be polymerized under alignment, and may have a polymerizable group in the molecule.

(2) Protective film

The protective film that can be laminated on one side or both sides of the polarizer can be a film made of the following resin: thermoplastic resin with light transmission (preferably optically transparent), such as chain polyolefin resin (polypropylene resins, etc.), polyolefin-based resins such as cyclic polyolefin-based resins (norcamphene-based resins, etc.); cellulose-based resins such as cellulose triacetate and cellulose diacetate; such as polyethylene terephthalate , Polyester resins of polybutylene terephthalate; polycarbonate resins; (meth)acrylic resins such as methyl methacrylate resins; polystyrene resins; polyvinyl chloride resins; Acrylonitrile/butadiene/styrene resin; acrylonitrile/styrene resin; polyvinyl acetate resin; polyvinylidene chloride resin; polyamide resin; polyacetal resin; modified poly Phenyl ether-based resins; polyamide-based resins; polyether-based resins; polyarylate-based resins; polyamideimide-based resins; polyimide-based resins, etc.

Chain polyolefin resins, except polyethylene resins (polyethylene resins belonging to ethylene homopolymers or copolymers mainly composed of ethylene), polypropylene resins (polypropylene resins belonging to propylene homopolymers or copolymers mainly composed of propylene) In addition to homopolymers of chain olefins such as copolymers), copolymers composed of two or more types of chain olefins are mentioned.

Cyclic polyolefin-based resins are a general term for resins polymerized with cyclic olefins as polymerization units, and examples include JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, etc. Resins listed. Cyclic polyolefin resins specifically include ring-opening (co)polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and chain olefins such as ethylene and propylene (typically are random copolymers), graft polymers modified with unsaturated carboxylic acids or their derivatives, and hydrogenated products of these. Among them, a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer can be preferably used as the cyclic olefin norbornene-based resin.

The polyester-based resin is a resin having an ester bond other than the following cellulose ester-based resins, and is generally composed of a polycondensate of a polycarboxylic acid or its derivative and a polyhydric alcohol. As the polyvalent carboxylic acid or its derivative, a divalent dicarboxylic acid or its derivative can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalene dicarboxylate. Dihydric diols can be used as the polyhydric alcohol, and examples thereof include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, and cyclohexanedimethanol. A representative example of the polyester-based resin includes polyethylene terephthalate, which is a polycondensate of terephthalic acid and ethylene glycol.

The (meth)acrylic resin is a resin mainly composed of a compound having a (meth)acryl group. Specific examples of (meth)acrylic resins include, for example: poly(meth)acrylate such as polymethyl methacrylate; methyl methacrylate/(meth)acrylic acid copolymer; methyl methacrylate/( Meth)acrylate copolymer; methyl methacrylate/acrylate/(meth)acrylic acid copolymer; (meth)methyl acrylate/styrene copolymer (MS resin, etc.); methyl methacrylate with Copolymers of alicyclic hydrocarbon-based compounds (such as methyl methacrylate/cyclohexyl methacrylate copolymer, methyl methacrylate/norbornyl (meth)acrylate copolymer, etc.). It is preferable to use polymers such as poly(meth)acrylate C _1-6 alkyl esters as the main component, more preferably to use methyl methacrylate as the main component (50 to 100% by weight, preferably 70 to 100% by weight) of methyl methacrylate resin.

Cellulose ester-based resins are esters of cellulose and fatty acids. Specific examples of cellulose ester resins include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Moreover, the thing which modified these copolymers or some hydroxyl groups with other substituents is mentioned. Among them, triacetyl cellulose is particularly preferred.

Polycarbonate-based resins are engineering plastics composed of polymers that link monomer units through carbonate groups.

It is also useful to control the retardation value of the protective film to a value suitable for image display devices such as liquid crystal display devices. For example, in a liquid crystal display device of an in-plane switching (IPS: in-plane switching) mode, it is preferable to use a film having substantially zero retardation as the protective film.

Substantially zero retardation means that the in-plane retardation value R ₀ is less than 10nm at a wavelength of 590nm, the absolute value of the retardation value R _th in the thickness direction at a wavelength of 590nm is less than 10nm, and the thickness direction at a wavelength of 480 to 750nm The absolute value of the retardation value R _th is 15nm or less.

For example, depending on the mode of the liquid crystal display device, the protective film may be stretched and/or shrunk to give a preferable retardation value. For example, for the purpose of viewing angle compensation, a retardation layer (or film) having a single-layer or multi-layer structure can be used as the protective film. In this case, the polarizing plate 10 may be an elliptic circular polarizing plate or a circular polarizing plate including a laminated structure of a polarizer and a retardation layer, or a polarizing plate including a retardation layer and having a viewing angle compensation function.

The thickness of the protective film is usually 1 to 100 μm, but is preferably 5 to 60 μm, more preferably 10 to 55 μm, and still more preferably 15 to 40 μm from the viewpoint of strength and handleability.

When bonding protective films to both surfaces of the polarizer, these protective films may be composed of the same type of thermoplastic resin or may be composed of different types of thermoplastic resins.

Also, the thicknesses may be the same or different. Also, they may have the same phase difference characteristics or may have different phase difference characteristics.

As mentioned above, at least any one of the protective films may be equipped with hard coat layer, antiglare layer, light diffusion layer, antireflection layer, low refractive index layer, antistatic layer, The surface treatment layer (coating layer) of the antifouling layer. In addition, the thickness of the protective film includes the thickness of the surface treatment layer.

From the viewpoint of suppressing air bubbles from entering between the surface protection film and the polarizer, the surface on the side of the surface protection film 30 in the polarizer 10 (the surface bonded to the surface protection film 30 can be a surface treatment layer) is preferably in accordance with JIS The arithmetic mean roughness Ra of B 0601:2013 is the smaller one. Specifically, Ra of the above-mentioned surface is preferably 0.3 μm or less, more preferably 0.2 μm or less, still more preferably 0.15 μm or less. Ra of the above-mentioned surface is usually 0.001 μm or more, for example, 0.005 μm or more.

The protective film can be bonded to the polarizer via an adhesive layer, for example. The adhesive for forming the adhesive layer may be a water-based adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive, preferably a water-based adhesive or an active energy ray-curable adhesive.

Examples of the water-based adhesive include an adhesive composed of a polyvinyl alcohol-based resin aqueous solution, a water-based two-component urethane-based emulsion adhesive, and the like. Among them, a water-based adhesive composed of a polyvinyl alcohol-based resin aqueous solution is preferably used. Polyvinyl alcohol-based resins include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, and vinyl acetate and other resins that can be copolymerized with the vinyl acetate. A polyvinyl alcohol-based copolymer obtained by saponifying a copolymer of monomers, or a modified polyvinyl alcohol-based polymer obtained by modifying a part of such hydroxyl groups. The water-based adhesive may contain cross-linking agents such as aldehyde compounds (glyoxal, etc.), epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, amine compounds, and polyvalent metal salts.

When using a water-based adhesive, after laminating the polarizer and the protective film, it is preferable to perform a drying step in order to remove water contained in the water-based adhesive. After the drying step, for example, a hardening step at a temperature of 20 to 45° C. can be provided.

The above-mentioned active energy ray-curable adhesive is an adhesive containing a curable compound cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, and is preferably an ultraviolet-curable adhesive.

The aforementioned curable compound may be a cation polymerizable curable compound or a radical polymerizable curable compound. Cationic polymerizable curable compounds can be, for example, epoxy-based compounds (compounds having one or more than two epoxy groups in the molecule), or oxetane-based compounds (having one or two epoxy groups in the molecule). Compounds of the above oxetane rings), or a combination thereof. Radical polymerizable curable compounds include, for example, (meth)acrylic compounds (compounds having one or more (meth)acryloxy groups in the molecule), or radical polymerizable double bonds other vinyl compounds, or combinations thereof. A cation polymerizable curable compound and a radical polymerizable curable compound may also be used together. The active energy ray-curable adhesive usually further contains a cationic polymerization initiator and/or a radical polymerization initiator for initiating the curing reaction of the above-mentioned curable compound.

When bonding a polarizer and a protective film, in order to improve adhesiveness, surface activation treatment may be performed on the bonding surface of at least any one of these. Surface activation treatment can include: dry treatment such as corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, ionizing active line treatment (ultraviolet treatment, electron beam treatment, etc.) Treatment; such as ultrasonic treatment using solvents such as water or acetone, saponification treatment, wet treatment of primer treatment. These surface activation treatments may be performed alone or in combination of two or more.

When bonding protective films on both sides of the polarizer, the adhesive used to bond the protective films can be the same type of adhesive or different type of adhesive.

(3) Other films

The polarizing plate 10 may include films other than the polarizer and the protective film, and representative examples thereof are brightness enhancement films and retardation films. When the polarizing plate 10 includes another film, the surface protection film 30 may be laminated on the surface of the film or on the surface of the surface treatment layer laminated on the film.

The brightness enhancement film is also called a reflective polarizer, which uses a polarization conversion element. The polarization conversion element has the function of separating the light emitted by the light source (backlight) into penetrating polarized light, reflected polarized light or scattered polarized light. By arranging the brightness enhancement film on the polarizer, the output efficiency of the linearly polarized light emitted from the polarizer can be improved by utilizing the returning light which is reflected polarized light or scattered polarized light. The brightness enhancing film can be laminated on the polarizer through an adhesive layer.

Another film such as a protective film may be interposed between the polarizer and the brightness enhancement film.

The brightness enhancement film can be, for example, an anisotropic reflective polarizer. An example of an anisotropic reflective polarizer is an anisotropic multilayer film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in another vibration direction. A specific example of the anisotropic reflective polarizer is "APF" manufactured by 3M Corporation. Another example of an anisotropic reflective polarizer is a composite of a cholesteric liquid crystal layer and a λ/4 plate (also known as a "quarter-wave plate"). A specific example is "PCF" manufactured by Nitto Denko Co., Ltd. Another example of the anisotropic reflective polarizer is a reflective grid polarizer, and its specific example is a metal grid reflective polarizer that can emit reflected polarized light in the visible light region by micro-processing metal, and adding metal fine particles in the polymer matrix and Extended membrane.

As mentioned above, such as hard coat layer, anti-glare layer, light diffusion layer, retardation layer (retardation layer with a retardation value of 1/4 wavelength, etc.), antireflection layer, low Refractive index layer, antistatic layer, surface treatment layer (coating layer) of antifouling layer. By forming this layer, the adhesiveness with a backlight tape and the uniformity of a display image can be improved. The thickness of the brightness enhancement film 50 is usually 10 to 100 μm, preferably 10 to 50 μm, more preferably 10 to 30 μm.

Examples of the retardation film include positive type A plates such as 1/4 wavelength (λ/4) plates and 1/2 wavelength (λ/2) plates, positive type C plates, and the like. The λ/4 plate is a layer whose in-plane retardation value Re(550) satisfies the relationship of 100nm≦Re(550)≦200nm at a wavelength of 550nm. The λ/4 plate can show inverse wavelength dispersion satisfying Re(450)<Re(550)<Re(650). The λ/2 plate is a layer in which Re(550) satisfies 210nm≦Re(550)≦300nm. The positive type C plate satisfies the relationship of Nz>Nx≧Ny, preferably its retardation value Rth(λ) in the thickness direction at a wavelength of λnm satisfies the relationship of -300nm≦Rth(550)≦-20nm.

The retardation film can be formed, for example, from the resins exemplified as the above-mentioned protective film material, and among them, cyclic olefin-based resins and styrene-based resins are preferable. The retardation layer may be formed of a single layer or a plurality of layers. The retardation layer having a plurality of layers may include, for example, a resin film (substrate film) exemplified as the above-mentioned protective film material and a layer formed by hardening a liquid crystal compound polymerized from a liquid crystal compound, or may include a plurality of layers such as 2 layers) The layer formed by hardening the liquid crystal compound. The layer having a phase difference may be a resin film and/or a layer formed by hardening a liquid crystal compound. The resin film also functions as the above-mentioned protective film.

The retardation film may be composed of one type of retardation layer, or may be composed of a plurality of types of retardation layers. When the retardation film is composed of a plurality of retardation layers, it is preferably a combination of a 1/4 wavelength plate and a 1/2 wavelength plate, or a combination of a 1/4 wavelength plate and a positive C plate.

The retardation film preferably contains a layer formed by curing a liquid crystal compound. When the retardation film is composed of a plurality of retardation layers, any one of the retardation layers may contain a layer formed by curing a liquid crystal compound. The type of liquid crystal compound is not particularly limited, but can be classified into rod-like type (rod-like liquid crystal compound) and discotic type (disco-like liquid crystal compound, discotic liquid crystal compound) according to its shape. In addition, there are low-molecular-weight type and high-molecular-weight type, respectively. Also, a polymer generally refers to a polymer having a degree of polymerization of 100 or more (Masao Doi, Masao Doi, 2 pages, Iwanami Shoten, 1992). Any liquid crystal compound can be used in this embodiment. In addition, two or more rod-shaped liquid crystal compounds, two or more types of discotic liquid crystal compounds, or a mixture of rod-shaped liquid crystal compounds and discotic liquid crystal compounds can also be used.

Furthermore, rod-like liquid crystal compounds are suitably used, for example, those described in claim 1 of JP-A-11-513019 or paragraphs [0026] to [0098] of JP-A-2005-289980. As the discotic liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 or paragraphs [0013]-[0108] of JP-A-2010-244038 can be used suitably.

The retardation layer is more preferably formed using a liquid crystal compound (rod-shaped liquid crystal compound or discotic liquid crystal compound) having a polymerizable group. This reduces temperature or humidity changes in optical properties.

The liquid crystal compound may be a mixture of two or more types. In this case, it is preferable that at least one has two or more polymerizable groups. That is, the retardation layer is preferably a layer formed by immobilizing a rod-shaped liquid crystal compound having a polymerizable group or a discotic liquid crystal compound having a polymerizable group by polymerization. In this case, it is no longer necessary to exhibit liquid crystallinity after layer formation.

The type of polymerizable group contained in the rod-shaped liquid crystal compound or the discotic liquid crystal compound is not particularly limited, for example, a polymerizable ethylenically unsaturated group or a ring polymerizable group is preferably a functional group that can undergo addition polymerization reaction. More specifically, (meth)acryl group, vinyl group, styryl group, allyl group, etc. are mentioned, for example. Among them, a (meth)acryl group is preferred. Also, (meth)acryl is a concept including both methacryl and acryl.

The formation method of the phase difference layer is not specifically limited, A well-known method is mentioned. For example, a composition for forming an optically anisotropic layer (hereinafter referred to as "composition") containing a liquid crystal compound having a polymerizable group is applied to a predetermined substrate (including a temporary substrate) to form a coating film, and the resulting coating film is subjected to curing treatment (irradiation of ultraviolet rays (photoirradiation treatment) or heat treatment) to manufacture a retardation layer. The produced retardation layer can be transferred onto a polarizer or a protective film, for example.

Coating of the composition can be performed by known methods such as wire bar coating, extrusion coating, direct gravure coating, reverse gravure coating, and slot die coating.

The composition may contain components other than the above-mentioned liquid crystal compounds. For example, the composition may contain a polymerization initiator. The polymerization initiator used can be selected according to the form of the polymerization reaction, for example, a thermal polymerization initiator or a photopolymerization initiator. Examples of photopolymerization initiators include α-carbonyl compounds, alcohol ketone ethers, α-hydrocarbon substituted aromatic alcohol ketone compounds, polynuclear quinone compounds, combinations of triaryl imidazole dimers and p-aminophenyl ketones, and the like. The amount of the polymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass relative to the total solids of the composition.

In addition, the composition may contain a polymerizable monomer from the viewpoint of the uniformity of the coating film and the film strength. Examples of polymerizable monomers include radically polymerizable or cationically polymerizable compounds. Among these, polyfunctional radically polymerizable monomers are preferred.

Furthermore, the polymerizable monomer is preferably one having copolymerizability with the above-mentioned polymerizable group-containing liquid crystal compound. Specific examples of polymerizable monomers include those described in paragraphs [0018] to [0020] of JP-A-2002-296423. The amount of the polymerizable monomer used is preferably from 1 to 50% by mass, more preferably from 2 to 30% by mass, based on the total mass of the liquid crystal compound.

In addition, the composition may contain a surfactant from the viewpoint of uniformity and film strength of the coating film. Surfactants include conventionally known compounds. Among these, fluorine-based compounds are particularly preferred.

Also, the composition may contain a solvent, preferably an organic solvent. Organic solvents can be exemplified by amides (such as N, N-dimethylformamide), argonoxides (such as dimethylsulfoxide), heterocyclic compounds (such as pyridine), hydrocarbons (such as benzene, hexane), alkanes Halides (e.g. chloroform, dichloromethane), esters (e.g. methyl acetate, ethyl acetate, butyl acetate), ketones (e.g. acetone, methyl ethyl ketone), ethers (e.g. tetrahydrofuran, 1,2-dimethyl Oxyethane).

Among them, alkyl halides and ketones are preferred. In addition, two or more types of organic solvents may be used in combination.

In addition, the composition may contain vertical alignment promoters such as vertical alignment agents on the interface side of the polarizer, vertical alignment agents on the air interface side, and horizontal alignment accelerators such as horizontal alignment agents on the interface side of the polarizer and horizontal alignment agents on the air interface side. . In addition, the composition may contain an adhesion improving agent, a plasticizer, a polymer, and the like in addition to the above-mentioned components.

The retardation film may contain an alignment film having a function of regulating the alignment direction of the liquid crystal compound. Alignment films are generally composed of polymers. Polymer materials for alignment films are described in many documents, and many commercial products are available. Among them, the polymer material is preferably polyvinyl alcohol or polyimide and its derivatives, particularly modified or unmodified polyvinyl alcohol.

In addition, the alignment film is subjected to a generally known alignment treatment. Examples include rubbing treatment, photo-alignment treatment by irradiating polarized light, etc., and photo-alignment treatment is preferable from the viewpoint of the surface roughness of the alignment film.

The thickness of the layer formed by hardening the liquid crystal compound is not particularly limited, but is preferably 0.5 to 10 μm, more preferably 1.0 to 5 μm. The thickness of the alignment film is not particularly limited, but it is usually less than 20 μm, preferably 0.01 to 10 μm, more preferably 0.01 to 5 μm, and even more preferably 0.01 to 1 μm.

(4) Adhesive layer

The polarizer 10 preferably has an adhesive layer 15 on its outermost surface. The adhesive layer can be used to attach the polarizing plate 10 to a display element (such as a liquid crystal cell, an organic EL element) or other optical components, and the adhesive layer is exposed by peeling off the release film 20 . In addition, the adhesive layer can be used for lamination of polarizers, protective films, brightness enhancement films, and retardation films. The adhesive layer 16 in FIGS. 1 and 2 corresponds to the adhesive layer. The adhesive layer can be composed of an adhesive composition mainly composed of (meth)acrylic, rubber, urethane, ester, polysiloxane, and polyvinyl ether resins. Among them, an adhesive composition using a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc. as a matrix polymer is preferred. The adhesive composition may be an active energy ray curing type or a thermosetting type.

The (meth)acrylic resin (matrix polymer) used in the adhesive composition is suitably used, for example, as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, ( A polymer or copolymer of one or more (meth)acrylates of 2-ethylhexyl methacrylate as monomers. Among the base polymers, copolymerization with a polar monomer is preferred. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, (meth)acrylic acid N,N-di Monomers with carboxyl group, hydroxyl group, amido group, amino group, epoxy group, etc.

The adhesive composition may contain only the above-mentioned matrix polymer, and usually further contains a crosslinking agent. Examples of cross-linking agents include metal ions with a valence of two or more that form a metal carboxylate with a carboxyl group; polyamine compounds that form an amide bond with a carboxyl group; polyepoxides or polyols that form an amide bond with a carboxyl group; Those who form ester bonds; belong to polyisocyanate compounds and form amide bonds with carboxyl groups. Among them, polyisocyanate compounds are preferred.

The active energy ray-curable adhesive composition has the property of being cured by irradiation with active energy rays such as ultraviolet rays or electron rays, and has adhesiveness even before the active energy ray is irradiated, so that it can be adhered to a substrate such as a film. It sticks to the body and hardens by irradiating active energy rays and can adjust the properties of the adhesive force. The active energy ray-curable adhesive composition is preferably an ultraviolet-curable adhesive composition. The active energy ray-curable adhesive composition may further contain an active energy ray polymerizable compound in addition to the matrix polymer and the crosslinking agent. Furthermore, a photopolymerization initiator, a photosensitizer, etc. may be contained as needed.

The adhesive composition may contain fine particles for imparting light scattering, beads (resin beads, glass beads, etc.), glass fibers, resins other than matrix polymers, antistatic agents, adhesion imparting agents, fillers ( Metal powder or other inorganic powder, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoamers, anti-corrosion agents, photopolymerization initiators and other additives.

An adhesive layer can be formed by applying an organic solvent dilution of the above-mentioned adhesive composition on a substrate and drying it. The substrate can be other optical films such as polarizers, protective films, brightness enhancement films, release films (such as the release film 20 ), and the like. When an active energy ray-curable adhesive composition is used, the formed adhesive layer can be irradiated with active energy rays to obtain a cured product having a desired degree of hardening.

The thickness of the adhesive layer 15 is usually 1 to 40 μm, but it is preferably 3 to 25 μm (for example, 3 to 20 μm, preferably 3 to 15 μm). The thickness of the subsequent layer 16 is usually 1 to 20 μm, preferably 3 to 10 μm.

The adhesive force of the adhesive layer 15 of the laminated release film 20 relative to the release film is 0.10 N/25 mm or less, preferably 0.04 N/25 mm or less. By setting it as such an adhesive force, when peeling off a peeling film, a polarizing plate does not become warped, and peelability can be improved more. Moreover, the adhesive force is 0.02 N/25mm or more. By setting it as such an adhesive force, even if impact is given to a laminated body by conveyance etc., it becomes easy to prevent that a gap will generate|occur|produce between a peeling film and an adhesive agent layer. In this specification, the adhesive force of an adhesive layer with respect to a peeling film is the value measured by the method described in the Example mentioned later.

<Surface Protection Film>

The surface protection film 30 may include a base film 31 and an adhesive layer 32 laminated on the base film 31 . The surface protection film 30 is a film used to protect the surface of the polarizing plate 10 , usually, for example, after the display element or other optical components are attached to the laminate, it will be peeled off together with the adhesive layer it has.

The surface protection film is generally more rigid than the brightness enhancement film, and it is important to improve the peelability of the release film. In this specification, the thickness of the surface protection film is the total value of the thickness of the base film and the thickness of the adhesive layer laminated on the base film, and is preferably 30 μm or more, more preferably 50 μm or more. On the other hand, if the thickness of the surface protection film is too large, peeling between the surface protection film and the polarizer is likely to occur when the release film is peeled off, so the thickness of the surface protection film is preferably 100 μm or less, more preferably 70 μm or less.

The base film is preferably a thermoplastic resin film. The thermoplastic resin constituting the thermoplastic resin film can be, for example: polyolefin resins such as polyethylene resins and polypropylene resins; cyclic polyolefin resins; polyethylene terephthalate or polyethylene naphthalate. Esters of polyester resins; polycarbonate resins; (meth)acrylic resins, etc. The substrate film may be of a single-layer construction or a multi-layer construction.

The thickness of the substrate film may be 20 to 150 μm (eg, 30 to 80 μm, preferably 30 to 60 μm). The composition of the adhesive layer basically refers to the description of the aforementioned adhesive layer of the polarizing plate.

In particular, the storage elastic modulus of the adhesive layer is preferably at most 0.15 MPa at 80° C., more preferably at most 0.14 MPa, and even more preferably at most 0.10 MPa. Usually, the storage elastic modulus of the adhesive layer at 80° C. is 0.01 MPa or more. In the present specification, the storage elastic modulus of the adhesive layer can be measured using a commercially available viscoelasticity measuring device, for example, a viscoelasticity measuring device "DYNAMIC ANALYZER RDA II" manufactured by REOMETRIC Corporation.

The surface protection film 30 may contain an antistatic agent. An antistatic agent may be contained in an adhesive layer, for example. Instead of containing an antistatic agent in the adhesive layer, or simultaneously with the antistatic agent, an antistatic layer containing an antistatic agent may be provided on the surface of the base film opposite to the surface on which the adhesive layer is laminated.

Examples of the antistatic agent include ionic compounds. An ionic compound is a compound having an inorganic cation or an organic cation, and an inorganic anion or an organic anion.

Two or more ionic compounds can be used.

<Peeling film>

The release film 20 is a film temporarily adhered to protect the surface of the adhesive layer before bonding the adhesive layer to a display element (for example, a liquid crystal cell, an organic EL element) or other optical members. By subjecting one side of the release film 20 to release treatment with a silicone-based, fluorine-based, or other release agent, the adhesion to the adhesive layer 15 can be adjusted. The peeling film 20 can be made of a thermoplastic resin film that has undergone a mold release process, and an adhesive layer can be attached to the surface that has undergone a mold release process.

The thermoplastic resin constituting the peeling film 20 can be, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, or a polyester resin such as polyethylene terephthalate or polyethylene naphthalate. wait. The thickness of the release film 20 is, for example, 10 to 50 μm.

The release film 20 can be peeled off, and the laminates 100 to 103 can be bonded to a display element (for example, a liquid crystal cell, an organic EL element). Moreover, the surface protection film 30 can be peeled off and it can be assembled in a display device (for example, a liquid crystal display device, an organic EL display device). When constructing a display device, the laminate of the present invention can be used as a polarizing plate disposed on the visual recognition side based on the display element, can also be used as a polarizing plate disposed on the opposite side to the visual recognition side, and can also be used as a visual recognition side and a visual recognition side. Check the polarizers on the opposite sides.

<Manufacturing method of laminate>

The laminated body can be obtained by manufacturing a strip-shaped laminated body from roll to roll while transporting each member constituting the laminated body separately and cutting it, or by separately preparing each member of a predetermined shape and stacking them sequentially And get.

Notching processing, drilling processing, and corner R processing can be performed using planing processing, end mill processing, etc. The processing method of notch processing and hole processing is preferably an end mill. An end mill is a type of cutting tool. The end mill processing system is different from the drill bit that only processes in the axial direction (only for hole opening), and can also process in the direction perpendicular to the rotation axis. Planing is a process in which a protruding blade is used to cut parallel to the processing surface, and the blade has a rotation axis parallel to the processing surface. Specifically, the processing apparatus and processing method described in JP-A-2018-22140 can be used.

<Manufacturing method of polarizing plate with surface protection film>

As a specific example, taking FIG. 5 as an example, the method of peeling off the peeling film from the laminated body 104 will be described.

The surface on the side of the surface protection film in the laminate was fixed to a holding table, and the adhesive tape 200 was bonded to the release film. The method of fixing the laminated body 104 is not particularly limited, and it may be fixed by a force absorbed by the surface protection film side, or may be fixed by adhesive force. From the viewpoint of not leaving traces on the polarizing plate, the adhesive force between the surface protection film to be fixed and the holding table is preferably 0.1 to 0.3 N/60 mm, more preferably 0.15 to 0.2 N/60 mm. According to the laminate of the present invention, even if the laminate is fixed with such a small pressure, it shows good peelability. For example, as shown in FIG. 5 , the position of attaching the adhesive tape 200 may be a corner portion of the end edge with a notch.

Next, the adhesive tape 200 is pulled up to peel off the release film. In Fig. 5, the angle θ between the end side perpendicular to the end side having the notch and the peeling direction 400 of the adhesive tape may be 0° or more and 90° or less. When the adhesive tape is attached to one end corner of the edge with the notch and the peeling film is peeled off, when the peeling tip reaches the notch, especially when the peeling tip reaches the region 300 shown in FIG. 5 , a peeling failure is likely to occur. That is, when the peeling tip reaches the inner corner of the notch, that is, the inner corner far from the position where the tape is pasted, peeling failure is likely to occur. According to the present invention, even when the peeling tip reaches the notch, peeling failure is less likely to occur. In the region 300 , in order to reduce the force of peeling off the release film, the angle θ is preferably not less than 25° and not more than 65°. Also, the peeling angle may be 90 to 180°, and the peeling speed may be 0.1 to 10 m/min.

(Example)

The following examples and comparative examples are used to further illustrate the present invention, but the present invention is not limited to these examples.

(1) Film thickness measurement method

Measurement was performed using a digital micrometer MH-15M manufactured by Nikon Corporation.

(2) Adhesion measurement method

The adhesion force between the release film and the adhesive layer of the polarizing plate was measured using Autograph (registered trademark) AGS-X, a desktop precision universal testing machine manufactured by Shimadzu Corporation.

(3) Peeling force of the peeling film

The laminate produced in each Example was fixed to a glass plate (holding stand) with the surface protection film facing downward. An adhesive sheet is used for fixing, and the fixing force (adhesion force) is 0.1 to 0.3 N/60mm. As shown in Fig. 5, an adhesive tape was attached to one corner of the end side having the notch so that the longitudinal direction of the adhesive tape was parallel to the longitudinal direction of the laminate. As for the adhesive tape, No. 315 of polyester adhesive tape manufactured by Nitto Denko Co., Ltd. was used, and the width was set to 12 mm, and the length of the bonding portion was set to 10 mm. Hold one end of the tape with a clamp and peel off the release film. The angle between the peeling direction of the tape and the end side perpendicular to the end side having the notch (angle θ in FIG. 5 ) was 45°. The peeling speed was 3 m/min, and the peeling angle was 180°. The peeling force when peeling off the peeling film was measured, and the maximum value of the peeling force was obtained.

(4) Evaluation method of peelability of release film

The laminate produced in each Example was fixed to a glass plate (holding stand) so that the surface protection film might face downward. An adhesive sheet is used for fixing, and the fixing force (adhesion force) is 0.1 to 0.3 N/60mm. As shown in FIG. 5 , an adhesive tape was attached to one corner of the end side having the notch so that the longitudinal direction of the adhesive tape was parallel to the longitudinal direction of the laminate. As for the adhesive tape, No. 315 of polyester adhesive tape manufactured by Nitto Denko Co., Ltd. was used, and the width was set to 12 mm, and the length of the bonding portion was set to 10 mm. Hold one end of the tape with a clamp and peel off the release film. The angle between the peeling direction of the tape and the end side perpendicular to the end side having the notch (angle θ in Fig. 5 ) was 45°. The peeling speed was 3 m/min, and the peeling angle was 180°. At this time, when the layer composed of the polarizing plate and the surface protection film floated from the glass fixing the laminated body, it was judged as peeling failure (NG), and when the peeling film could be peeled without lifting, it was judged as good peeling (OK).

[Making laminated body]

Polarizers (thickness 8 μm) made of polyvinyl alcohol resin adsorbed and aligned with iodine.

Attach a hard-coated cyclic olefin-based resin (COP) film (thickness 25 μm) to one side of the polarizer through an ultraviolet curable adhesive, and attach the same adhesive to the other side of the polarizer Cellulose triacetate (TAC) membrane (thickness 20 μm).

Next, a retardation film including a layer in which a polymerizable liquid crystal compound is cured is prepared. This retardation film has a layer structure in which a λ/4 plate (thickness 2 μm) and a positive type C plate (thickness 3 μm) are laminated via an ultraviolet curable adhesive (thickness 2 μm). The retardation film and the TAC film were bonded through an adhesive layer (thickness: 5 μm) so that the λ/4 plate and the TAC film became bonding surfaces.

The acrylic adhesive layer (thickness: 25 μm) formed on the release film was laminated on the positive C plate. A surface protection film including a base film made of polyester resin and an acrylic pressure-sensitive adhesive layer is laminated on the COP film.

The obtained film was cut into a rectangle with a long side of 150 mm and a short side of 70 mm. The long side direction is parallel to the absorption axis of the polarizer. The laminate has the following layer composition: release film/adhesive layer/retardation layer (including two layers of liquid crystal compound cured layer)/TAC film/polarizer/COP film with hard coat layer/surface protection membrane. The thickness of the polarizing plate was 80 μm, the thickness of the release film was 38 μm, and the thickness of the surface protection film was 53 μm.

The adhesive force between the adhesive layer and the release film was 0.02 N/25 mm, and no peeling between the adhesive layer and the release film was observed due to transport or the like.

[Example 1]

Notch machining is performed on one of the short sides of the laminate by end milling. The shape of the notch is such that the depth d is 2 mm, and the radius of curvature r of the two inner corners is 2 mm. The shape of the notch is the shape shown in Fig. 4 (d) when viewed from above.

[Examples 2 to 15, Comparative Examples 1 to 11]

Except having made the shape of the notch part into the shape shown in Table 1, it carried out the notch processing to the laminated body in the same manner as in Example 1.

[Comparative Example 12]

One short side of the laminate was cut with a knife to form a notch. R processing is not performed on the two inner corners, but the two inner corners are each at a right angle.

The maximum value of the peeling force was measured for the laminates produced in Examples 1 to 15 and Comparative Examples 1 to 11 above, and the peelability was further evaluated. The results are shown in Table 1. As shown in Table 1, in the laminates of Examples 1 to 15, the peeling of the peeling film was performed favorably. Also, in any of the Examples, no defect occurred in peeling between the polarizing plate and the surface protection film. In the laminates of Comparative Examples 1 to 12, the release film could not be easily peeled off. The maximum value of the peel force of Comparative Example 12 exceeded 1.0N. Also, in any of the laminates, the maximum value of the peeling force was recorded when the peeling tip reached the region 300 shown in FIG. 5 . That is, when the peeling front reaches the inner corner of the notch, that is, the inner corner farther from the position where the tape is pasted, the maximum value of the peeling force is recorded.

(Industrial Utilization)

The present invention is useful because it can provide a laminate that does not cause peeling failure of the peeling film.

10‧‧‧polarizer

11‧‧‧Polarizer

12, 13‧‧‧Protective film

14‧‧‧retardation film

15. 32‧‧‧adhesive layer

16‧‧‧adhesion layer

20‧‧‧Peeling film

30‧‧‧Surface protection film

31‧‧‧Substrate film

100, 101‧‧‧laminated body

Claims (3)

A laminate comprising a surface protective film layered on one side of a polarizing plate, a release film layered on the other side of the polarizing plate, and the polarizing plate includes a polarizer, wherein the polarizing plate is provided with an adhesive on the surface of the peeling film side. In the agent layer, the adhesive force between the peeling film and the adhesive layer is 0.02N/25mm or more and 0.10N/25mm or less, and the laminate has a notch in plan view, the depth of the notch is d (mm), and the notch is When the radius of curvature of the middle inner corner is r (mm), d is 2 mm to 20 mm, when d is 2 mm to 5 mm, r is 2 mm or more, and d is more than 5 mm to 6 mm, r is 8 mm or more, and d is When it exceeds 6 mm and is less than 8 mm, r is 13 mm or more, and when d is 8 mm or more, r is 17 mm or more, and when the peeling film is peeled from the edge having the aforementioned notch, the maximum value of the peeling force is 1.0 N or less. The laminated body described in item 1 of the scope of the patent application, wherein the shape of the aforementioned notch satisfies the following formula (1), r>3d-14 (1) In the formula (1), d (mm) represents the depth of the aforementioned notch , r (mm) represents the radius of curvature of the inner corner of the aforementioned notch. A method of manufacturing a polarizing plate with a surface protection film, comprising the following steps: attaching one end corner of the end edge with the aforementioned notch in the laminated body as described in any one of the claims 1 to 2 of the patent application The adhesive tape sticking step; and the peeling step of pulling up the aforementioned adhesive tape and peeling off the aforementioned peeling film from the aforementioned laminate, wherein, in the aforementioned peeling step, the peeling direction of the aforementioned adhesive tape is perpendicular to the end edge having the aforementioned notch The included angle angle is more than 25° and less than 65°.

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