JP7016605B2 - Laminated body for touch panel and foldable image display device - Google Patents

Description

The present invention relates to a laminated body for a touch panel and a foldable image display device.

Optical films used for touch panels, which have rapidly become widespread in recent years, are required to have excellent hardness and excellent durable folding performance in which cracks do not occur even when the optical film is repeatedly folded.

However, since hardness and folding performance are usually in a trade-off relationship, with conventional optical films, if the hardness is improved, the durable folding performance is lowered, and if the durable folding performance is improved, the hardness is lowered. Therefore, it was not possible to improve these performances at the same time.

Further, in a touch panel, glass is often used for the display screen. However, although glass has a high hardness, it breaks when folded and cannot be given folding performance, and since glass is a material with a large specific gravity, it is necessary to make it thinner in order to reduce its weight. There is a problem that when the glass is made thin, the strength is lowered and the glass is easily broken.

Further, for example, in Patent Document 1, as an optical film having hardness and flexibility, two hard coat layers having different Vickers hardness are provided on one surface of a base film such as a cellulose acylate film and a polyester film. The provided optical film is disclosed.
However, although such an optical film has excellent hardness, the base film may be cut or a fold mark may be left due to repeated folding, and the film does not satisfy the durable folding performance required in recent years. I didn't.

Further, since it has excellent mechanical strength, it is considered to use a polyimide film as a base film in an optical film, but in general, a polyimide film has low transparency and is used as an optical film. There was a problem that it was not suitable.
Further, even if a polyimide film is used as the base film, it is difficult to achieve both the excellent durable folding performance and hardness required in recent years.

Japanese Unexamined Patent Publication No. 2014-186210

In view of the above situation, it is an object of the present invention to provide a touch panel laminate having excellent hardness, transparency and durable folding performance, and a foldable image display device using the touch panel laminate. Is.

INDUSTRIAL APPLICABILITY The present invention is a laminate for a touch panel which is used as a surface material of a touch panel and has a base film and at least one resin cured layer, from the resin cured layer side interface of the base film to the base film. An elution layer is formed in the range up to 300 nm in the thickness direction of the above, and the resin cured layer contains the material components constituting the base film eluted from the elution layer, and the base material is contained. The film is a polyimide film or an aramid film, and the resin cured layer has a first hard coat layer provided on the base film side and a side surface of the first hard coat layer opposite to the base film side. 3. It has a second hard coat layer provided on the top, the thickness of the first hard coat layer is 2.0 μm or more and 5.0 μm or less, and the thickness of the second hard coat layer is 0.5 μm or more. The Martens hardness at the center of the cross section of the first hard coat layer is 500 MPa or more and less than 1000 MPa, the Martens hardness at the center of the cross section of the second hard coat layer is 350 MPa or more and 600 MPa or less, and the resin curing is 0 μm or less. The value of the pencil hardness test (750 g load) specified in JIS K5600-5-4 (1999) of the layer is 5H or more, and the resin cured layer does not have an uneven shape on the surface opposite to the base film side. In that case, the total light transmission rate is 85% or more, and when the resin cured layer has an uneven shape on the surface opposite to the base film side, the total light transmission rate is 80% or more, 3 mm. A touch panel laminate characterized in that cracks or breaks do not occur when the entire surface of the touch panel laminate is folded 180 ° at intervals of 100,000 times on both sides of the touch panel laminate. be.

上記式（１）中、ｎは、繰り返し単位であり、２以上の整数を表す。 Further , the base film is a polyimide film, and it is preferable that the raw material of the polyimide film has a structure represented by the following formula (1).

In the above equation (1), n is a repeating unit and represents an integer of 2 or more.

In the laminated body for a touch panel of the present invention, the thickness of the base film is preferably 10 to 55 μm .
Further , the second hard coat layer contains a cured product of a polyfunctional (meth) acrylate monomer as a resin component, and the first hard coat layer contains a cured product of a polyfunctional (meth) acrylate as a resin component. At the same time, it is preferable to contain silica fine particles dispersed in the resin component of the first hard coat layer.
Further, the silica fine particles are preferably reactive silica fine particles.
Further, it is preferable that the resin cured layer has an uneven shape on the surface opposite to the base film side.
Further, the laminated body for a touch panel of the present invention preferably has antifouling performance, and more preferably has a conductive layer.

A foldable image display device characterized by using the laminated body for a touch panel of the present invention is also one of the present inventions.
Hereinafter, the present invention will be described in detail.

The laminate for a touch panel of the present invention has a base film and at least one cured resin layer.
In the laminated body for a touch panel of the present invention, an elution layer is formed near the interface on the resin cured layer side of the base film.
The elution layer is a layer formed by being modified by a composition (for example, a composition for a hard coat layer described later) applied on the base film when forming the resin cured layer. In the laminated body for a touch panel of the present invention, as will be described later, the material component of the base film eluted from the elution layer is contained in the resin cured layer.
The elution layer is formed in the vicinity of the resin-cured layer-side interface of the base film, but specifically, it is formed in the range from the resin-cured layer-side interface to 300 nm in the thickness direction of the base film. Is preferable. The elution layer can be confirmed by observing a cross-sectional microscope in the thickness direction of the laminate for a touch panel of the present invention, and the range in which the elution layer is formed is any 10 observed in the cross-sectional microscope observation. It is the average value of the thickness of the place.
In the laminated body for a touch panel of the present invention, the base film is a polyimide film or an aramid film.
Here, since the polyimide film and the aramid film have an aromatic ring in the molecule, they are generally colored (yellow), but when used for optical film applications, the skeleton in the molecule is changed. It is a film called "transparent polyimide" or "transparent aramid" that has improved transparency. On the other hand, colored conventional polyimide films and the like are preferably used for electronic materials such as printers and electronic circuits in terms of heat resistance and flexibility.
The touch panel laminate using the base film made of these materials does not crack or break in the durable folding test described later, and not only has the excellent durable folding performance required in recent years, but also has excellent hardness and excellent hardness. It can also have transparency.
Further, the polyimide film and the aramid film are also excellent in heat resistance, and can be imparted with further excellent hardness and transparency by firing.

Here, in the laminated body for a touch panel of the present invention, the above-mentioned excellent hardness was measured under the conditions of the pencil hardness test (750 g load) specified in JIS K5600-5-4 (1999) of the resin cured layer described later. It means that the hardness is 5H or more, preferably 6H or more, and more preferably 7H or more.
Further, in the laminated body for a touch panel of the present invention, the above-mentioned excellent transparency means that when the resin cured layer described later does not have an uneven shape on the surface opposite to the base film side, the total light transmittance is high. It means that it is 85% or more, and it is preferable that the total light transmittance is 90% or more.
On the other hand, when the resin cured layer described later has an uneven shape on the surface opposite to the base film side, the above-mentioned excellent transparency means that the total light transmittance is 80% or more, and all of them. The light transmittance is preferably 85% or more.

Examples of the polyimide film include compounds having a structure represented by the following formula.
In the following formula, n is a repeating unit and represents an integer of 2 or more.

Further, the aramid film generally has a skeleton represented by the following formulas (18) and (19), and the aramid film is specifically, for example, the following formula (20). Examples include the represented compounds.
In the following formula, n is a repeating unit and represents an integer of 2 or more.

As the polyimide film or the aramid film represented by the above formulas (1) to (17) and (20), commercially available ones may be used.
Examples of the commercially available product of the transparent polyimide film include Neoprim manufactured by Mitsubishi Gas Chemical Company, Inc., and examples of the commercially available product of the transparent aramid film include Mictron manufactured by Toray Industries, Inc.
Further, as the polyimide film or the aramid film represented by the above formulas (1) to (17) and (20), those synthesized by a known method may be used.
For example, a method for synthesizing a polyimide film represented by the above formula (1) is described in JP-A-2009-132091, and specifically, the following formula (21).

Reaction of 4,4'-hexafluoropropylidenebisphthalic acid dianhydride (FPA) represented by 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (TFDB). Can be obtained by

The weight average molecular weight of the polyimide film or the aramid film is preferably in the range of 3,000 to 500,000, more preferably in the range of 5,000 to 300,000, and further preferably in the range of 10,000 to 200,000. .. If the weight average molecular weight is less than 3000, sufficient strength may not be obtained, and if it exceeds 500,000, the viscosity increases and the solubility decreases, so that a film having a smooth surface and a uniform film thickness can be obtained. It may not be possible.
In the present specification, the weight average molecular weight is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).

Among the polyimide films or aramid films, a polyimide film or an aramid film having a structure in which charge transfer within or between molecules is unlikely to occur is preferable because it has excellent transparency, and specifically, the above formula (1). )-(8) and the like, fluorinated polyimide films such as the above formulas (9) to (12), and aramid films having a halogen group such as the above formula (20).
Further, since the fluorinated polyimide films of the above formulas (1) to (8) have a fluorinated structure, they have high heat resistance and are not colored by the heat during the production of the polyimide film. Therefore, it has excellent transparency.
Since the substrate film can have a hardness of 5H or more measured under the conditions of the pencil hardness test (750 g load) specified in JIS K5600-5-4 (1999) of the resin cured layer described later, the above formula (1). )-(8) or the like, or an aramid film having a halogen group such as the above formula (20) is preferably used. Above all, it is more preferable to use the polyimide film represented by the above formula (1) because it can impart an extremely excellent hardness of 7H or more to the pencil hardness.

The base film preferably has a thickness of 10 to 55 μm. If the thickness of the base film is less than 10 μm, the curl of the laminated body for a touch panel of the present invention becomes large, the hardness becomes insufficient, and the pencil hardness described later may not be 4H or more. When the laminate for a touch panel of the present invention is manufactured by Roll to Roll, wrinkles are likely to occur, which may lead to deterioration of the appearance. On the other hand, if the thickness of the base film exceeds 55 μm, the folding performance of the touch panel laminate of the present invention may be insufficient, and the requirements of the durable folding test described later may not be satisfied, and the touch panel of the present invention may not be satisfied. The laminate becomes heavy, which is not preferable in terms of weight reduction.

It is preferable that the touch panel laminate of the present invention does not crack or break when the test of folding the entire surface of the touch panel laminate by 180 ° at intervals of 3 mm is repeated 100,000 times.
FIG. 1 is a cross-sectional view schematically showing a test in which the entire surface of the laminated body for a touch panel of the present invention is folded by 180 ° at intervals of 3 mm (hereinafter, also referred to as a durable folding test).
As shown in FIG. 1A, in the durable folding test, first, one side of the touch panel laminate 10 of the present invention and the other side facing the one side are arranged in parallel. It is fixed to the upper fixing portion 11 and the lower fixing portion 12 respectively. The touch panel laminate of the present invention may have any shape, but the touch panel laminate 10 of the present invention in the durable folding test is preferably rectangular.
Further, as shown in FIG. 1, the upper fixing portion 11 is fixed, and the lower fixing portion 12 can move left and right while maintaining parallelism with the upper fixing portion 11.
In the present invention, the distance between the upper fixing portion 11 and the lower fixing portion 12 is 3 mm.

Next, as shown in FIG. 1 (b), by moving the lower fixing portion 12 to the left, the bent portion of the test piece 10 is moved to the vicinity of the other side fixed to the lower fixing portion 12. Further, as shown in FIG. 1 (c), by moving the lower fixing portion 12 to the right, the bent portion of the test piece 10 is moved to the vicinity of one side fixed to the upper fixing portion 11.
By moving the lower fixing portion 12 as shown in FIGS. 1A to 1C, the entire surface of the touch panel laminate of the present invention can be folded by 180 °.
The touch panel laminate of the present invention is the touch panel laminate of the present invention when the folding test represented by FIGS. 1 (a) to 1 (c) described above is performed 100,000 times on the touch panel laminate 10 of the present invention. It is preferable that the body 10 does not crack or break. If the touch panel laminate 10 of the present invention is cracked or broken within 100,000 times, the durable folding performance of the touch panel laminate of the present invention may be insufficient. In the present invention, it is more preferable that cracking or breaking does not occur when the durable folding test is performed on the touch panel laminate 10 of the present invention 150,000 times.
Further, the touch panel laminate 10 of the present invention may not be cracked or broken when the durable folding test is performed on one side, but the durable folding test is performed on both sides. In that case, it is preferable that cracking or breaking does not occur.
In the present invention, it is preferable that the above-mentioned laminate 10 for a touch panel of the present invention is rotated by 90 ° and the same durable folding test is performed without cracking or breaking.

The laminated body for a touch panel of the present invention has at least one cured resin layer.
In the present invention, the resin cured layer contains a material component constituting the base film eluted from the elution layer described above. By having such a resin cured layer, the laminated body for a touch panel of the present invention can have the above-mentioned excellent hardness and excellent durable folding performance.
The content of the material component of the base film contained in such a resin cured layer is particularly limited as long as it can have the above-mentioned excellent hardness and excellent durable folding performance. Although not limited, for example, it is preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the resin component of the cured resin layer. If it is less than 0.5 parts by mass, the durable folding performance of the touch panel laminate of the present invention may be insufficient, and if it exceeds 5.0 parts by mass, the hardness of the touch panel laminate of the present invention is insufficient. May be sufficient. A more preferable lower limit of the content of the material component of the base film contained in the resin cured layer is 0.8 parts by mass, and a more preferable upper limit is 3.0 parts by mass.
The content of the material component of the base film contained in the cured resin layer is, for example, the content of the base film in the cured resin layer when observed with a cross-sectional microscope in the thickness direction of the cured resin layer. It can be obtained by calculating the ratio of material components.
In such a laminate for a touch panel of the present invention, the material of the base film is selected, the thickness of the base film is controlled, and the strength of the cured resin layer and the strength of the cured resin layer are applied to the base film. It can be obtained by controlling the laminating method.
In the laminated body for a touch panel of the present invention, the resin cured layer is provided on the first hard coat layer provided on the base film side and on the side surface opposite to the base film side of the first hard coat layer. It is preferable to have a second hard coat layer. It is preferable that the material component of the above-mentioned base film is eluted and contained in the above-mentioned first hard coat layer.
Hereinafter, when it is not necessary to distinguish between the first hard coat layer and the second hard coat layer, they are also simply referred to as “hard coat layer”.

The first hard coat layer is a layer for imparting hardness, and it is preferable that the Martens hardness at the center of the cross section is 500 MPa or more and less than 1000 MPa.
By setting the Martens hardness of the first hard coat layer in the above range, the hardness of the resin cured layer in the pencil hardness test (750 g load) specified in JIS K5600-5-4 (1999) is set to 4H or more. Further, it is possible to impart sufficient durable folding performance to the laminated body for a touch panel of the present invention. The more preferable lower limit of the Martens hardness at the center of the cross section of the first hard coat layer is 600 MPa, and the more preferable upper limit is 950 MPa.

The second hard coat layer is a layer for imparting the above-mentioned durable foldability and the following scratch resistance, and the Martens hardness at the center of the cross section is preferably 350 MPa or more and 600 MPa or less. By setting the Martens hardness of the second hard coat layer within the above range, it has sufficient durable folding performance, and while applying a load of 1 kg / cm ² with # 0000 steel wool, the surface of the hard coat layer. It is possible to impart extremely excellent scratch resistance such that scratches do not occur in the steel wool test in which the steel wool is rubbed back and forth 3500 times. The more preferable lower limit of the Martens hardness at the center of the cross section of the second hard coat layer is 375 MPa, and the more preferable upper limit is 575 MPa.
In the laminated body for a touch panel of the present invention, the maltens hardness of the first hard coat layer is preferably larger than the maltens hardness of the second hard coat layer. By having such a relationship of Martens hardness, the laminated body for a touch panel of the present invention has a particularly good pencil hardness. This is because when the pencil hardness test is performed on the touch panel laminate of the present invention and a load is applied to the pencil to push it in, the deformation of the touch panel laminate of the present invention is suppressed, and scratches and dents are reduced. Because.
As a method of increasing the maltens hardness of the first hard coat layer to be larger than the maltens hardness of the second hard coat layer, for example, control is performed so that the content of silica fine particles described later is contained more on the first hard coat layer side. How to do it, etc.
In the laminated body for a touch panel of the present invention, the hard coat layer may have a single structure, and in this case, the silica fine particles described later are unevenly distributed on the base film side in the hard coat layer, that is, the hard. It is preferable that the abundance ratio of the silica fine particles in the coat layer is larger on the base film side and is inclined so as to be smaller toward the side opposite to the base film side.
In the present specification, the "martence hardness" is the hardness when the indenter is pushed in by 500 nm by the hardness measurement by the nanoindentation method.
In the present specification, the measurement of the Martens hardness by the nanoindentation method was performed using "TI950 TriboIndenter" manufactured by HYSITRON. That is, a Berkovich indenter (triangular pyramid) as the indenter is pushed in from the surface of the hard coat layer of the touch panel laminate of the present invention by 500 nm, held constant to relax the residual stress, and then unloaded to be relaxed. The max load is measured, and the Martens hardness is calculated by P _max / A using the max load (P _max (μN)) and the recessed area (A (nm ² )) having a depth of 500 nm.

In the laminated body for a touch panel of the present invention, it is preferable that the first hard coat layer contains a cured product of polyfunctional (meth) acrylate as a resin component and also contains silica fine particles dispersed in the resin component. ..
Examples of the polyfunctional (meth) acrylate include trimethyl propanetri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and pentaerythritol tri (meth) acrylate. Meta) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethyl propantri (meth) acrylate , Ditrimethylol propanetetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) ) Acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, bisphenol di (meth) acrylate, diglycerin tetra (meth) acrylate, adamantyldi (meth) acrylate, isoboroldi (meth) acrylate, dicyclopentane (dicyclopentane) Examples thereof include meth) acrylates, tricyclodecandi (meth) acrylates, ditrimethylolpropanetetra (meth) acrylates, and those modified with PO, EO, caprolactone and the like.
Among these, those having 3 to 6 functionalities are preferable because they can preferably satisfy the above-mentioned Martens hardness, and for example, pentaerythritol triacrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and pentaerythritol tetraacrylate (PETTA) are preferable. ), Dipentaerythritol pentaacrylate (DPPA), trimethylolpropane tri (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol deca (meth) acrylate and the like are preferable.
In addition, in this specification, (meth) acrylate means acrylate and methacrylate.

The silica fine particles are preferably reactive silica fine particles. The reactive silica fine particles are silica fine particles capable of forming a crosslinked structure with the polyfunctional (meth) acrylate, and by containing the reactive silica fine particles, the first hard coat layer can be formed. The hardness can be sufficiently increased.

The reactive silica fine particles preferably have a reactive functional group on the surface thereof, and as the reactive functional group, for example, a polymerizable unsaturated group is preferably used, and more preferably photocurable. It is an unsaturated group, and particularly preferably an ionizing radiation curable unsaturated group. Specific examples of the reactive functional group include ethylenically unsaturated bonds such as a (meth) acryloyl group, a vinyl group and an allyl group, and an epoxy group.

The reactive silica fine particles are not particularly limited, and conventionally known ones can be used, and examples thereof include the reactive silica fine particles described in JP-A-2008-165040. Examples of commercially available products of the reactive silica fine particles include those manufactured by Nissan Chemical Industries, Ltd .; MIBK-SD, MIBK-SDMS, MIBK-SDL, MIBK-SDZL, and JGC Catalysts and Chemicals Co., Ltd .; V8802, V8803 and the like. ..

Further, the silica fine particles may be spherical silica fine particles, but are preferably atypical silica fine particles. Spherical silica fine particles and atypical silica fine particles may be mixed.
In the present specification, the atypical silica fine particles mean silica fine particles having a potato-like random unevenness on the surface.
Since the surface area of the atypical silica fine particles is larger than that of the spherical silica fine particles, the inclusion of such atypical silica fine particles increases the contact area with the polyfunctional (meth) acrylate and the like, and the hard coat. The hardness of the layer (pencil hardness) can be made more excellent.
Whether or not it is the atypical silica fine particles can be confirmed by observing the cross section of the first hardcoat layer with an electron microscope.

When the silica fine particles are atypical silica fine particles, the average particle size of the atypical silica fine particles is preferably 5 to 200 nm. If it is less than 5 nm, it becomes difficult to produce the fine particles themselves, the fine particles may agglomerate with each other, and it may be extremely difficult to disshape the fine particles. Atypical silica fine particles may have poor dispersibility and aggregate at the stage. On the other hand, if the average particle size of the atypical silica fine particles exceeds 200 nm, large irregularities may be formed on the hard coat layer, or problems such as an increase in haze may occur.
The average particle size of the atypical silica fine particles is the average of the maximum value (major diameter) and the minimum value (minor diameter) of the distance between two points on the outer periphery of the atypical silica fine particles that appeared in the cross-sectional microscope observation of the hard coat layer. The value.

By controlling the size and blending amount of the silica fine particles, the hardness (martence hardness) of the first hard coat layer can be controlled, and as a result, the first hard coat layer and the second hard coat layer can be formed. can.
For example, when the first hard coat layer is formed, the silica fine particles have a diameter of 5 to 200 nm, preferably 25 to 60 parts by mass with respect to 100 parts by mass of the resin component.

Further, the second hard coat layer preferably contains a cured product of polyfunctional (meth) acrylate as a resin component.
Examples of the polyfunctional (meth) acrylate include the same as those described above.
Further, the second hard coat layer may contain a polyfunctional urethane (meth) acrylate and / or a polyfunctional epoxy (meth) acrylate or the like in addition to the polyfunctional (meth) acrylate as a resin component.
Further, the second hard coat layer may contain the above-mentioned silica fine particles. The content of the silica fine particles in the second hard coat layer is not particularly limited, but is preferably 0 to 20% by mass in the second hard coat layer, for example.

In any case of the first hard coat layer and the second hard coat layer, the hard coat layer may contain a material other than the above-mentioned materials as long as the above-mentioned Martens hardness is satisfied. For example, as the material of the resin component, a polymerizable monomer or a polymerizable oligomer that forms a cured product by irradiation with ionizing radiation may be contained.
Examples of the polymerizable monomer or the polymerizable oligomer include a (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule and a (meth) acrylate oligomer having a radically polymerizable unsaturated group in the molecule. Be done.
Examples of the (meth) acrylate monomer having a radically polymerizable unsaturated group in the molecule or the (meth) acrylate oligomer having a radically polymerizable unsaturated group in the molecule include urethane (meth) acrylate and polyester (meth). ) Monomers or oligomers such as acrylates, epoxy (meth) acrylates, melamine (meth) acrylates, polyfluoroalkyl (meth) acrylates, silicone (meth) acrylates and the like. These polymerizable monomers or polymerizable oligomers may be used alone or in combination of two or more. Of these, urethane (meth) acrylates that are polyfunctional (six or more functional) and have a weight average molecular weight of 1,000 to 10,000 are preferable.

The material constituting the hard coat may further contain a monofunctional (meth) acrylate monomer in order to adjust the hardness and the viscosity of the composition, improve the adhesion, and the like.
Examples of the monofunctional (meth) acrylate monomer include hydroxyethyl acrylate (HEA), glycidyl methacrylate, methoxypolyethylene glycol (meth) acrylate, isostearyl (meth) acrylate, 2-acryloyloxyethyl succinate, acryloyl morpholine, and N. -Acryloyloxyethyl hexahydrophthalimide, cyclohexyl acrylate, tetrahydrofuryl acrylate, isobornyl acrylate, phenoxyethyl acrylate, adamantyl acrylate and the like can be mentioned.

The weight average molecular weight of the polymerizable monomer is preferably less than 1000, more preferably 200 to 800, from the viewpoint of improving the hardness of the cured resin layer.
The weight average molecular weight of the polymerizable oligomer is preferably 1,000 to 20,000, more preferably 1,000 to 10,000, and even more preferably 2,000 to 7,000.
In the present specification, the weight average molecular weight of the polymerizable monomer and the polymerizable oligomer is the polystyrene-equivalent weight average molecular weight measured by the GPC method.

The hard coat layer may contain an ultraviolet absorber (UVA).
As will be described later, the laminated body for a touch panel of the present invention is particularly preferably used for a mobile terminal such as a foldable smartphone or tablet terminal, but such a mobile terminal is often used outdoors, and therefore. There is a problem that the polarizing element disposed below the touch panel laminate of the present invention is easily deteriorated by being exposed to ultraviolet rays.
However, since the hard coat layer is arranged on the display screen side of the polarizing element, if the hard coat layer contains an ultraviolet absorber, deterioration due to exposure of the polarizing element to ultraviolet rays is preferable. Can be prevented.
The ultraviolet absorber (UVA) may be contained in the above-mentioned base film. In this case, the ultraviolet absorber (UVA) may not be contained in the hard coat layer.

Examples of the ultraviolet absorber include a triazine-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, and a benzotriazole-based ultraviolet absorber.

Examples of the triazine-based ultraviolet absorber include 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1,3,5-triazine. , 2- [4-[(2-Hydroxy-3-dodecyloxypropyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2 , 4-Bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3,5-triazine, 2- [4-[(2-Hydroxy-3-tridecyl) Oxypropyl) Oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, and 2- [4-[(2-hydroxy-3- (2) '-Ethyl) hexyl) oxy] -2-hydroxyphenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine and the like can be mentioned.
Examples of commercially available triazine-based ultraviolet absorbers include TINUVIN460, TINUVIN477 (all manufactured by BASF), LA-46 (manufactured by ADEKA), and the like.

Examples of the benzophenone-based ultraviolet absorber include 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2', 4,4'-tetrahydroxy. Examples thereof include benzophenone, 2-hydroxy-4-methoxybenzophenone, hydroxymethoxybenzophenone sulfonic acid and its trihydrate, sodium hydroxymethoxybenzophenone sulfonate and the like.
Examples of commercially available benzophenone-based ultraviolet absorbers include CHMASSORB81 / FL (manufactured by BASF).

Examples of the benzotriazole-based ultraviolet absorber include 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazole-2-yl) phenyl] propionate, 2 -(2H-benzotriazole-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, 2- [5-chloro (2H) -benzotriazole-2-yl] -4-methyl- 6- (tert-butyl) phenol, 2- (2H-benzotriazole-2-yl) -4,6-di-tert-pentylphenol, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-Hydroxy-3', 5'-di-tert-butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole, 2- (2'-Hydroxy-3', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-(3'', 4'', 5'', 5'', 6''-Tetrahydrophthalimidemethyl) -5'-Methylphenyl) Benzotriazole, 2,2-Methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazole-2-) Il) phenol), 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole and the like.
Examples of commercially available benzotriazole-based ultraviolet absorbers include KEMISORB71D, KEMISORB79 (all manufactured by Chemipro Kasei Co., Ltd.), JF-80, JAST-500 (all manufactured by Johoku Chemical Co., Ltd.), and ULS-1933D. (Manufactured by one company), UVA-93 (manufactured by Otsuka Chemical Co., Ltd.) and the like.

Among the above-mentioned ultraviolet absorbers, triazine-based ultraviolet absorbers and benzotriazole-based ultraviolet absorbers are preferably used.
The ultraviolet absorber preferably has high solubility in the resin component constituting the hard coat layer, and preferably has less bleed-out after the above-mentioned durable folding test.
The UV absorber is preferably polymerized or oligomerized.
The ultraviolet absorber is preferably a polymer or oligomer having a benzotriazole, triazine, or benzophenone skeleton, and specifically, an arbitrary ratio of (meth) acrylate having a benzotriazole or benzophenone skeleton and methyl methacrylate (MMA). It is preferably heat-copolymerized with.
When the laminated body for a touch panel of the present invention is applied to an OLED (organic light emitting diode), the UVA can also play a role of protecting the OLED from ultraviolet rays.

The content of the ultraviolet absorber is not particularly limited, but is preferably 1 to 6 parts by mass with respect to 100 parts by mass of the resin solid content of the hard coat layer. If it is less than 1 part by mass, the effect of containing the above-mentioned ultraviolet absorber in the hard coat layer may not be sufficiently obtained, and if it exceeds 6 parts by mass, the hard coat layer is significantly colored or its strength is lowered. May occur. The more preferable lower limit of the content of the ultraviolet absorber is 2 parts by mass, and the more preferable upper limit is 5 parts by mass.

The layer thickness of the hard coat layer is preferably 2.0 to 5.0 μm in the case of the first hard coat layer, and 0.5 to 4.0 μm in the case of the second hard coat layer. Is preferable. If it is less than the lower limit of each layer thickness, the hardness of the hard coat layer may be significantly lowered, and if it exceeds the upper limit of each layer thickness, it becomes difficult to coat the coating liquid for forming the hard coat layer. In addition, workability (particularly, chipping resistance) due to being too thick may deteriorate.
The more preferable lower limit of the layer thickness of the first hard coat layer is 2.5 μm, the more preferable upper limit is 4.5 μm, the more preferable lower limit of the layer thickness of the second hard coat layer is 1.0 μm, and the more preferable upper limit is 1.0 μm. It is 3.5 μm.
The layer thickness of the hard coat layer is an average value of the thicknesses at any 10 points obtained by observing the cross section with an electron microscope (SEM, TEM, STEM).

The laminate for a touch panel of the present invention having the hard coat layer preferably has a transmittance of light having a wavelength of 380 nm of 10% or less, more preferably 8% or less. If the transmittance exceeds 10%, when the laminated body for a touch panel of the present invention is used for a mobile terminal, the polarizing element may be exposed to ultraviolet rays and easily deteriorate. A more preferable upper limit of the transmittance of light having a wavelength of 380 nm in the hard coat layer is 5%.
Further, the hard coat layer preferably has a haze of 2.5% or less. If it exceeds 2.5%, whitening of the display screen may become a problem when the laminated body for a touch panel of the present invention is used for a mobile terminal. A more preferable upper limit of the haze is 1.5%, and a further preferable upper limit is 1.0%.
The transmittance and haze can be measured according to JIS K-7361 using a haze meter (manufactured by Murakami Color Technology Laboratory, product number; HM-150).
The haze of the entire touch panel laminate of the present invention is the sum of the haze of the hard coat layer and the haze of the base film, and when the haze of the base film is higher than 1%, it is for the touch panel of the present invention. The overall haze of the laminate is higher than 1%.

The hard coat layer may be, for example, a lubricant, a plasticizer, a filler, an antistatic agent, an antiblocking agent, a cross-linking agent, a light stabilizer, an antioxidant, a dye, a colorant such as a pigment, or the like, if necessary. Ingredients may be contained.

Further, in the laminate for a touch panel of the present invention, another hard coat layer (hereinafter referred to as “hardcourt layer”) is provided on the opposite side surface of the above-mentioned base film on which the above-mentioned hard coat layer (first hard coat layer and second hard coat layer) is provided. , Also referred to as a back surface hard coat layer) may be formed. Examples of the back surface hard coat layer include layers similar to the above-mentioned hard coat layer.
Further, as the back surface hard coat layer, it is preferable to have a back surface hard coat layer (1) and / or a back surface hard coat layer (2).
Examples of the back surface hard coat layer (1) and the back surface hard coat layer (2) include a layer having the same composition and thickness as the above-mentioned first hard coat layer or the above-mentioned second hard coat layer.
That is, when the laminated body for a touch panel of the present invention has the back surface hard coat layer, the back surface hard coat layer has the same back surface hard coat layer (1) as the first hard coat layer described above. A structure having a back surface hard coat layer (1) similar to the second hard coat layer, a back surface hard coat layer (1) similar to the first hard coat layer described above, and a back surface hard coat similar to the second hard coat layer described above. A structure in which the layer (2) is laminated in this order from the base film side, the back surface hard coat layer (1) similar to the second hard coat layer described above and the back surface hard coat similar to the first hard coat layer described above. A structure in which the layer (2) is laminated in this order from the base film side can be mentioned.
When the touch panel laminate of the present invention is attached to the touch panel, the back surface hard coat layer is arranged on the side surface opposite to the outermost surface side, so that the antifouling performance described later is unnecessary.

Further, the laminated body for a touch panel of the present invention preferably has antifouling performance. Such antifouling performance can be obtained, for example, by incorporating an antifouling agent in the hard coat layer.
The surface of the hard coat layer containing the antifouling agent preferably has a contact angle of 100 ° or more with respect to water, and in the laminated body for a touch panel of the present invention immediately after production, the surface of the hard coat layer is against water. The contact angle is more preferably 105 ° or more, and a steel wool resistance test is performed in which the surface of the second hard coat layer is rubbed back and forth 3500 times while applying a load of 1 kg / cm ² with # 0000 steel wool. The contact angle of the surface of the hard coat layer after that with water is preferably 90 ° or more, and more preferably 103 ° or more.

It is preferable that the antifouling agent is unevenly distributed on the outermost surface side of the hard coat layer. When the antifouling agent is uniformly contained in the hard coat layer, it is necessary to increase the addition amount in order to impart sufficient antifouling performance, which may lead to a decrease in the film strength of the hard coat layer. When the hard coat layer has the first hard coat layer and the second hard coat layer described above, the antifouling agent is unevenly distributed on the outermost surface side of the second hard coat layer arranged on the outermost surface side. It is preferable that it is contained.
As a method of unevenly distributing the antifouling agent on the outermost surface side of the hard coat layer, for example, at the time of forming the hard coat layer, the coating film formed by using the composition for a hard coat layer described later is dried and cured. Before the coating film is heated, the viscosity of the resin component contained in the coating film is lowered to increase the fluidity, and the antifouling agent is unevenly distributed on the outermost surface side, or the surface tension is low. The antifouling agent is selected and used, and the antifouling agent is floated on the surface of the coating film without applying heat when the coating film is dried, and then the coating film is cured to bring the antifouling agent to the outermost surface side. Examples include a method of uneven distribution.

The antifouling agent is not particularly limited, and examples thereof include a silicone-containing antifouling agent, a fluorine-containing antifouling agent, and a silicone-containing and fluorine-containing antifouling agent, which may be used alone. It may be mixed and used. Further, the antifouling agent may be an acrylic antifouling agent.
The content of the antifouling agent is preferably 0.01 to 3.0 parts by weight with respect to 100 parts by mass of the resin material described above. If it is less than 0.01 parts by weight, sufficient antifouling property may not be imparted to the hard coat layer, and since the slipperiness is poor, scratches may occur even in the steel wool resistance test. On the other hand, if it exceeds 3.0 parts by weight, the hardness of the hard coat layer may decrease, and the antifouling agent itself becomes a ball-like (micellar) state, and the resin component of the hard coat layer and the antifouling agent However, phase separation (sea island state) may occur finely, and there is a risk of whitening.
Further, the antifouling agent preferably has a weight average molecular weight of 20,000 or less, and is a compound having preferably 1 or more, more preferably 2 or more reactive functional groups in order to improve the durability of the antifouling performance. Is. Above all, excellent scratch resistance can be imparted by using an antifouling agent having two or more reactive functional groups.
When the antifouling agent does not have a reactive functional group, the antifouling agent is transferred to the back surface when the laminated body for the touch panel of the present invention is in the form of a roll or in the form of a sheet. Therefore, when an attempt is made to attach or paint another member on the back surface, the other member may be peeled off, and further, the other member may be easily peeled off by performing a plurality of folding tests.
The weight average molecular weight can be determined by polystyrene conversion by gel permeation chromatography (GPC).

Further, the antifouling agent having the above-mentioned reactive functional group has good antifouling performance durability (durability), and among them, the hard coat layer containing the above-mentioned fluorine-containing antifouling agent has fingerprints. It is hard to stand out (not noticeable) and has good wiping ability. Further, since the surface tension of the hard coat layer forming composition at the time of coating can be lowered, the leveling property is good and the appearance of the hard coat layer to be formed is good.
Further, the hard coat layer containing the silicone-containing antifouling agent has good slipperiness and steel wool resistance.
The touch panel equipped with the laminate for the touch panel of the present invention containing such a silicone-containing antifouling agent in the hard coat layer has a good slipperiness when touched with a finger, a pen, or the like, and thus has a good tactile sensation. In addition, fingerprints are less likely to be attached to the hard coat layer (less conspicuous), and the wiping property is also good. Further, since the surface tension of the composition for forming the hard coat layer (composition for the hard coat layer) at the time of coating can be lowered, the leveling property is good and the appearance of the hard coat layer to be formed is good. It will be a thing.
Further, the antifouling agent having the above-mentioned reactive functional group is available as a commercially available product, and as a commercially available product other than the above, for example, as a silicone-containing antifouling agent, for example, SUA1900L10 (Shin-Nakamura Chemical Co., Ltd.). , SUA1900L6 (manufactured by Shin-Nakamura Chemical Co., Ltd.), Ebeclyl1360 (manufactured by Daicel Cytec), UT3971 (manufactured by Nippon Synthetic Co., Ltd.), BYKUV3500 (manufactured by Big Chemie), BYKUV3510 (manufactured by Big Chemie), BYKUV3570 (manufactured by Big Chemie), X22 -164E, X22-174BX, X22-2426, KBM503. KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), TEGO-RAD2250, TEGO-RAD2300. Examples thereof include TEGO-RAD2200N, TEGO-RAD2010, TEGO-RAD2500, TEGO-RAD2600, TEGO-RAD2700 (manufactured by Evonik Japan), Megafuck RS854 (manufactured by DIC) and the like.
Examples of the fluorine-containing antifouling agent include Optool DAC, Optool DSX (manufactured by Daikin Industries, Ltd.), Megafuck RS71, Megafuck RS74 (manufactured by DIC), LINK152EPA, LINK151EPA, LINK182UA (manufactured by Kyoeisha Chemical Co., Ltd.), and Footergent. Examples thereof include 650A, footergent 601AD, and footergent 602.
Examples of the fluorine-containing and silicone-containing antifouling agents having a reactive functional group include Megafuck RS851, Megafuck RS852, Megafuck RS853, Megafuck RS854 (manufactured by DIC Corporation), Opstar TU2225, and Opstar TU2224. (Manufactured by JSR Corporation), X71-1203M (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like can be mentioned.

In addition, in the laminated body for a touch panel of the present invention, in order to improve the coatability of the composition at the time of forming the first hard coat layer, a surfactant (leveling agent) is applied to the first hard coat layer, if necessary. May be included.
If the amount of the above leveling agent added is too large, bubbles are generated in the coating film when forming the first hard coat layer, which causes defects, or when the second hard coat layer is laminated, the second hard The coat layer may repel or the adhesion may deteriorate.
Further, if the coating film for forming the first hard coat layer is also non-uniform, or if there are irregularities or defects, cracks or breaks may occur in the above-mentioned durable folding test.

The hardcoat layer can be formed, for example, by using a composition for a hardcoat layer to which the resin component and reactive silica fine particles, an ultraviolet absorber, other components, and the like are added.
The composition for the hard coat layer may contain a solvent, if necessary.

Examples of the solvent include alcohols (eg, methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol, diacetone alcohol), ketones (eg, acetone, methyl ethyl ketone, etc.). Methylisobutylketone, cyclopentanone, cyclohexanone, heptanone, diisobutylketone, diethylketone, diacetone alcohol), esters (methyl acetate, ethyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, methyl acrylate, PGMEA), aliphatic Hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene chloride, chloroform, carbon tetrachloride), aromatic hydrocarbons (eg, benzene, toluene, xylene), amides (eg, dimethylformamide, dimethylacetamide) , N-Methylpyrrolidone), ethers (eg, diethyl ether, dioxane, hydrocarbons), ether alcohols (eg, 1-methoxy-2-propanol), carbonates (dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate) and the like. .. These solvents may be used alone or in combination of two or more.
Among them, as the solvent, the resin components such as the above-mentioned polymerizable monomer and / or the above-mentioned polymerizable oligomer and other additives can be dissolved or dispersed, and the above-mentioned composition for a hard coat layer can be suitably applied. Therefore, methyl isobutyl ketone and methyl ethyl ketone are preferable.

The composition for the hard coat layer preferably has a total solid content of 25 to 55%. If it is lower than 25%, residual solvent may remain or whitening may occur. If it exceeds 55%, the viscosity of the composition for the hard coat layer becomes high, the coatability is lowered, and unevenness or streaks may appear on the surface. The solid content is more preferably 30 to 50%.

As a method for producing the laminate for a touch panel of the present invention using the composition for a hard coat layer, for example, the composition for a hard coat layer is applied on one surface of the base film to form a coating film. Examples thereof include a method of forming and curing the coating film after drying.
In the laminated body for a touch panel of the present invention, the composition for the hard coat layer is applied to form a coating film, so that the resin component, the solvent, etc. in the composition for the hard coat layer can be applied to the base film. It acts on the layer-forming side interface and is modified to form the above-mentioned elution layer. Then, by controlling the drying conditions and the curing conditions of the coating film according to the material of the base film and the composition of the composition for the hard coat layer, the coating of the material constituting the base film from the elution layer is applied. The amount of elution into the film can be controlled, and the laminate for a touch panel of the present invention having the desired hardness and durable folding performance can be obtained.

Examples of the method of applying the composition for a hard coat layer on one surface of the base film to form a coating film include a spin coating method, a dip method, a spray method, a die coating method, a bar coating method, and a roll. Various known methods such as a coater method, a meniscus coater method, a flexographic printing method, a screen printing method, and a bead coater method can be mentioned.

As a method for drying the coating film, for example, it is preferable to dry the coating film at 30 to 120 ° C. for 10 to 120 seconds.
Further, as a method for curing the coating film, a known method may be appropriately selected depending on the composition of the composition for the hard coat layer and the like. For example, if the composition for the hard coat layer is an ultraviolet curable type, the coating film may be cured by irradiating the coating film with ultraviolet rays.

When the hard coat layer has the above-mentioned first hard coat layer and the second hard coat layer, the composition for the first hard coat layer prepared for forming the first hard coat layer is used as the base. The coating film applied on the material film is dried and then half-cured. By forming the second hard coat layer, which will be described later, in a state where the coating film is not completely cured and is half-cured, the adhesion between the first hard coat layer and the second hard coat layer becomes extremely excellent. .. Examples of the method of half-curing the coating film include a method of irradiating the dried coating film with ultraviolet rays at 100 mJ / cm ² or less.
The composition for the second hard coat layer prepared for forming the second hard coat layer is applied onto the first hard coat layer that has been half-cured, and the formed coating film is dried, and then the coating film is applied. By completely curing, a second hard coat layer can be formed on the first hard coat layer. By completely curing the coating film using the composition for the second hard coat layer, the steel wool resistance of the surface of the hard coat layer (second hard coat layer) becomes excellent. As a method for completely curing the coating film of the composition for the second hard coat layer, for example, the coating film is placed in a nitrogen atmosphere (oxygen concentration is preferably 500 ppm or less, more preferably 200 ppm or less, still more preferably 100 ppm or less). Then, a method of curing by irradiation with ultraviolet rays can be mentioned. Further, the steel wool resistance can be improved by increasing the degree of cross-linking (reaction rate) on the side surface opposite to the first hard coat layer side of the second hard coat layer which is the outermost surface.
When the first hard coat layer and the second hard coat layer are formed by the above-mentioned method, ultraviolet irradiation is performed in order to obtain a sufficiently cured hard coat layer (first hard coat layer and second hard coat layer). The total amount is preferably 150 mJ / cm ² or more.

In the present invention, the hard coat layer may be formed by using a conventionally known thermosetting sol-gel method.
In the above-mentioned heat-curing sol-gel method, generally, an alkoxysilane compound having an epoxy group is hydrolyzed to obtain a gel having lost its fluidity by a polycondensation reaction, and this gel is heated to form an oxide. The method for obtaining the oxide is generally known, but in addition, for example, a method of hydrolyzing an alkoxysilane compound and subjecting it to a polycondensation reaction to obtain an oxide, or a method of heating an alkoxysilane compound having an isocyanate group to cause polycondensation. The method may be a method of obtaining an oxide, or a method of mixing an alkoxysilane compound and a compound having an isocyanate group at an arbitrary ratio, hydrolyzing the compound, and causing a polycondensation reaction.
The alkoxysilane compound having an epoxy group is not particularly limited as long as it has at least one epoxy group and at least one hydrolyzable silicon group in the molecule, and is, for example, γ-glycidoxypropyltrimethoxysilane or γ. -Glysidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane and the like can be mentioned.

The hydrolyzate of the alkoxysilane compound having an epoxy group can be obtained by dissolving the alkoxysilane compound having an epoxy group in an appropriate solvent and performing hydrolysis. Examples of the solvent used include alcohols such as methyl ethyl ketone, isopropyl alcohol, methanol, ethanol, methyl isobutyl ketone, ethyl acetate and butyl acetate, ketones, esters, halogenated hydrocarbons, toluene and aromatic hydrocarbons such as xylene. Alternatively, a mixture thereof may be mentioned. Of these, methyl ethyl ketone is preferable because it has an appropriate drying rate for forming a film.

When performing the above hydrolysis, a catalyst may be used if necessary. The catalyst to be used is not particularly limited, and a known acid catalyst or base catalyst can be used.
Examples of the acid catalyst include organic acids such as acetic acid, chloroacetic acid, citric acid, benzoic acid, dimethylmalonic acid, formic acid, propionic acid, glutaric acid, glycolic acid, malonic acid, maleic acid, toluenesulfonic acid and oxalic acid. Inorganic acids such as hydrochloric acid, nitrate and silane halide; acidic sol-like fillers such as acidic colloidal silica and thiania oxide sol, and the like can be mentioned. These may be used alone or in combination of two or more.
Examples of the base catalyst include an aqueous solution of an alkali metal such as sodium hydroxide and calcium hydroxide or a hydroxide of an alkaline earth metal, an aqueous solution of ammonia, and an aqueous solution of amines. Of these, the use of hydrochloric acid or acetic acid, which has high efficiency of catalytic reaction, is preferable.

The alkoxysilane compound is not particularly limited, and for example, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, and methyltri. Butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dimethyldiisopropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldi Ethoxysilane, diethyldiisopropoxysilane, diethyldibutoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc. Can be mentioned.
These may be used in combination of two or more.

The alkoxysilane compound having an isocyanate group is not particularly limited, and examples thereof include 3-isocyanatepropyltriethoxysilane, 3-isocyanatepropyltrimethoxysilane, and 2-isocyanateethyltrin-propoxysilane.

The compound having an isocyanate group is not particularly limited, and is, for example, tolylene diisocyanate (TDI), 3,3'-tolylen-4,4'-isocyanate, diphenylmethane 4,4'-diisocyanate (MDI), triphenyl. Methan p, p', p''-triisocyanate (TM), 2,4-tolylene dimer (TT), naphthalene-1,5-diisocyanate, tris (4-phenylisocyanate) thiophosphate, crude (MDI) ), TDI trimer, dicyclohexamethane 4,4'-diisocyanate (HMDI), hydrogenated TDI (HTDI), metaxylylene diisocyanate (XDI), hexahydromethoxylylene diisocyanate (HXDI), hexamethylene diisocyanate, Trimethylpropane-1-methyl-2-isocyano-4-coverbamate, polymethylenepolyphenylisocyanate, 3,3'-dimethoxy4,4'-diphenyldiisocyanate, diphenylether 2,4,1'-triisocyanate, m-xylylene Examples thereof include isocyanate (MXDI) and polymethylene polyphenyl isocyanate (PAPI).

In the laminated body for a touch panel of the present invention, the resin cured layer may or may not have an uneven shape on the surface opposite to the base film, but may be reflected by external light or on the screen. From the viewpoint of improving visibility such as preventing glare, it is preferable to have an uneven shape on the surface opposite to the base film side.
The resin cured layer having the uneven shape may be one in which the first hard coat layer has an uneven shape on the surface opposite to the base film, or the second hard coat layer is on the opposite side to the base film. It may have an uneven shape on the surface of the surface.
For the uneven shape of the resin cured layer, the average spacing between the irregularities on the surface of the cured resin layer opposite to the base film side is Sm, the average inclination angle of the uneven portion is θa, and the arithmetic average roughness of the irregularities is Ra. When, it is preferable to satisfy the following formula.
30 μm <Sm <90 μm,
2 <θa <15,
0.5 μm <Ra <1.5 μm
The above Sm, θa and Ra are values obtained by a method conforming to JIS B 0601-1994, and can be obtained by measuring with, for example, a surface roughness measuring instrument: SE-3400 / manufactured by Kosaka Laboratory.

For the uneven shape of the resin cured layer, the average spacing between the irregularities on the surface of the cured resin layer opposite to the base film side is Sm, the average inclination angle of the uneven portion is θa, and the arithmetic average roughness of the irregularities is Ra. When, it is preferable to satisfy the following formula.
Sm: preferably 30 μm <Sm <600 μm,
More preferably 30 μm <Sm <90 μm
θa: preferably 0.1 <θa <1.2, more preferably 0.1 <θa <0.5
Ra: preferably 0.02 μm <Ra <1.0 μm,
More preferably 0.02 μm <Ra <0.20 μm
The above Sm, θa and Ra are values obtained by a method conforming to JIS B 0601-1994, and can be obtained by measuring with, for example, a surface roughness measuring instrument: SE-3400 / manufactured by Kosaka Laboratory.

The uneven shape of the surface of the cured resin layer on the opposite side to the base film side may be formed by a composition containing an antiglare agent, formed by phase separation of the resin, or formed by embossing. good.
Above all, the uneven shape of the surface of the cured resin layer on the opposite side to the base film side is preferably formed by the composition for the cured resin layer containing an antiglare agent.
The antiglare agent is fine particles, and the shape is not particularly limited, such as spherical, elliptical, and amorphous. Further, as the antiglare agent, inorganic or organic fine particles can be used, and transparent fine particles are preferable.
Specific examples of the organic fine particles include plastic beads. Examples of the plastic beads include polystyrene beads (refractive index 1.60), melamine beads (refractive index 1.57), acrylic beads (refractive index 1.49 to 1.53), and acrylic-styrene copolymer beads (refractive index 1). .54 to 1.58), benzoguanamine-formaldehyde condensate beads (refractive index 1.66), melamine-formaldehyde condensate (refractive index 1.66), polycarbonate beads (refractive index 1.57), polyethylene beads (refractive index) 1.50), etc. The plastic beads preferably have a hydrophobic group on the surface thereof, and examples thereof include polystyrene beads.
Examples of the inorganic fine particles include inorganic silica beads having a specific shape such as amorphous silica and spherical particles.
Among them, it is preferable to use acrylic-styrene copolymer beads and / or amorphous silica as the antiglare agent.

The average particle size of the antiglare agent is preferably 1 to 10 μm, more preferably 3 to 8 μm. The average particle size is a value obtained by measuring with a laser diffraction / scattering method particle size distribution measuring device in the state of a toluene 5% by mass dispersion.
The content of the antiglare agent is preferably 1 to 40 parts by mass, more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the binder resin solid content.

Further, it is preferable that the resin cured layer having an uneven shape on the surface opposite to the base film side further contains internally scattered particles. The internally scattered particles can impart internal haze and suppress surface glare (scintillation) and the like.
Examples of the internally scattered particles include organic particles having a relatively large difference in refractive index from the binder resin constituting the cured resin layer. For example, acrylic-styrene copolymer beads (refractive index 1.54 to 1. 58), melamine beads (refraction 1.57), polystyrene beads (refraction 1.60), polyvinyl chloride beads (refraction 1.60), benzoguanamine-formaldehyde condensate beads (refraction 1.66), melamine -Plastic beads such as formaldehyde condensate (refraction rate 1.66) can be mentioned.
As these particles, those having both the properties as an antiglare agent and the properties as internally scattered particles may be used.

The average particle size of the internally scattered particles is preferably 0.5 to 10 μm, more preferably 1 to 8 μm. The average particle size is a value obtained by measuring with a laser diffraction / scattering method particle size distribution measuring device in the state of a toluene 5% by mass dispersion.
The amount of the internally scattered particles added is preferably 0.1 to 40% by mass, more preferably 1 to 30% by mass, based on 100 parts by mass of the binder resin solid content.

Examples of the binder resin of the resin cured layer having an uneven shape on the surface opposite to the base film side include the same binder resin that can be used for the hard coat layer described above.

The resin cured layer having an uneven shape on the surface opposite to the base film side may further contain other components, if necessary, to the extent that the effect of the present invention is not impaired. Examples of the other components include the same components as those that can be used for the above-mentioned hard coat layer.

The resin cured layer having an uneven shape on the surface opposite to the base film side may be formed by a known method. For example, a binder resin, an antiglare agent and other components can be mixed and dispersed with a solvent to prepare a composition for a cured resin layer, which can be formed by a known method. The method for preparing the composition for the cured resin layer and the method for forming the cured resin layer using the same are the same as the above-mentioned method for preparing the composition for the hard coat layer and the method for forming the hard coat layer. Each method can be listed.

The layer thickness of the cured resin layer having an uneven shape on the surface opposite to the base film side is preferably 1 to 10 μm. If it is less than 1 μm, antiglare may not be suitably imparted. If it exceeds 10 μm, curls and cracks may occur.
The layer thickness is a value obtained by observing the cross section of the optical laminate with an electron microscope (SEM, TEM, STEM).

It is preferable that the laminated body for a touch panel of the present invention further has a conductive layer.
The conductive layer preferably contains, for example, a conductive fibrous filler as a conductive agent.

The conductive fibrous filler preferably has a fiber diameter of 200 nm or less and a fiber length of 1 μm or more.
If the fiber diameter exceeds 200 nm, the haze value of the conductive layer to be manufactured may be high or the light transmission performance may be insufficient. The preferable lower limit of the fiber diameter of the conductive fibrous filler is 10 nm from the viewpoint of the conductivity of the conductive layer, and the more preferable range of the fiber diameter is 10 to 180 nm.
Further, if the fiber length of the conductive fibrous filler is less than 1 μm, it may not be possible to form a conductive layer having sufficient conductive performance, and aggregation occurs, resulting in an increase in haze value and a decrease in light transmission performance. The preferable upper limit of the fiber length is 500 μm, the more preferable range of the fiber length is 3 to 300 μm, and the more preferable range is 10 to 30 μm.
For the fiber diameter and fiber length of the conductive fibrous filler, for example, using an electron microscope such as SEM, STEM, or TEM, the fiber diameter and fiber length of the conductive fibrous filler can be adjusted by 1000 to 500,000 times. It can be obtained as the average value of 10 measured points.

The conductive fibrous filler is preferably at least one selected from the group consisting of, for example, conductive carbon fibers, metal fibers and metal-coated synthetic fibers.
Examples of the conductive carbon fiber include vapor phase growth method carbon fiber (VGCF), carbon nanotubes, wire cups, wire walls and the like. One kind or two or more kinds of these conductive carbon fibers can be used.

As the metal fiber, for example, a fiber produced by a wire drawing method in which stainless steel, iron, gold, silver, aluminum, nickel, titanium or the like is drawn thin and long, or a fiber produced by a cutting method can be used. One kind or two or more kinds of such metal fibers can be used. Among these metal fibers, metal fibers using silver are preferable because they are excellent in conductivity.

Examples of the metal-coated synthetic fiber include fibers obtained by coating acrylic fiber with gold, silver, aluminum, nickel, titanium, or the like. One kind or two or more kinds of such metal-coated synthetic fibers can be used. Among these metal-coated synthetic fibers, metal-coated synthetic fibers using silver are preferable because they are excellent in conductivity.

The content of the conductive fibrous filler in the conductive layer is preferably 20 to 3000 parts by mass with respect to 100 parts by mass of the resin component constituting the conductive layer, for example. If it is less than 20 parts by mass, it may not be possible to form a conductive layer having sufficient conductive performance, and if it exceeds 3000 parts by mass, the haze of the conductive laminate of the present invention becomes high or the light transmission performance is insufficient. May become. Further, as the amount of the binder resin entering the contacts of the conductive fibrous filler increases, the conduction of the conductive layer deteriorates, and the conductive laminate of the present invention may not obtain the target resistance value. The more preferable lower limit of the content of the conductive fibrous filler is 50 parts by mass, and the more preferable upper limit is 1000 parts by mass.
The resin component of the conductive layer is not particularly limited, and examples thereof include conventionally known materials.

Examples of other conductive agents other than the above conductive fibrous filler include quaternary ammonium salts, pyridinium salts, various cationic compounds having cationic groups such as primary to tertiary amino groups, and sulfonic acids. Anionic compounds having anionic groups such as bases, sulfate ester bases, phosphate ester bases, and phosphonic acid bases, amphoteric compounds such as amino acids and aminosulfate esters, nonions such as aminoalcohols, glycerins, and polyethylene glycols. Higher molecular weight compounds such as sex compounds, organic metal compounds such as tin and titanium alkoxides and metal chelate compounds such as acetylacetonate salts thereof, and tertiary amino groups. , A quaternary ammonium group, or a monomer or oligomer that has a metal chelating moiety and is polymerizable by ionizing radiation, or a polymerizable functional group that can be polymerized by ionizing radiation, and is a coupling agent. Examples thereof include polymerizable compounds such as organic metal compounds.
The content of the other conductive agent is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the resin component constituting the conductive layer. If it is less than 1 part by mass, it may not be possible to form a conductive layer having sufficient conductive performance, and if it exceeds 50 parts by mass, the haze of the conductive laminate of the present invention becomes high or the light transmission performance is insufficient. May become.

Further, as the conductive agent, for example, conductive fine particles can also be used.
Specific examples of the conductive fine particles include those made of a metal oxide. Examples of such metal oxides include ZnO (refractive index 1.90, hereinafter, the numerical value in parentheses represents the refractive index), CeO ₂ (1.95), Sb ₂ O ₃ (1.71). , SnO ₂ (1.997), indium tin oxide (1.95), often abbreviated as ITO, In ₂ O ₃ (2.00), Al ₂ O ₃ (1.63), antimony-doped tin oxide. (Abbreviation; ATO, 2.0), aluminum-doped zinc oxide (abbreviation: AZO, 2.0) and the like can be mentioned. The average particle size of the conductive fine particles is preferably 0.1 nm to 0.1 μm. Within such a range, when the conductive fine particles are dispersed in the raw material of the resin component constituting the conductive layer, a composition capable of forming a highly transparent film having almost no haze and good total light transmittance can be formed. You get things.
The content of the conductive fine particles is preferably 10 to 400 parts by mass with respect to 100 parts by mass of the resin component constituting the conductive layer. If it is less than 10 parts by mass, it may not be possible to form a conductive layer having sufficient conductive performance, and if it exceeds 400 parts by mass, the haze of the conductive laminate of the present invention becomes high or the light transmission performance is insufficient. May become.

Examples of the conductive agent include aromatic conjugated poly (paraphenylene), heterocyclic conjugated polypyrrole, polythiophene, aliphatic conjugated polyacetylene, heteroatomic conjugated polyaniline, and mixed conjugated poly. (Phenylene vinylene), a double-chain type conjugated system which is a conjugated system having a plurality of conjugated chains in a molecule, a conductive complex which is a polymer obtained by grafting or block-coweighting the above-mentioned conjugated polymer chain to a saturated polymer, etc. It is also possible to use the high molecular weight conductive agent of.

The conductive layer may contain refractive index adjusting particles.
Examples of the refractive index adjusting particles include high refractive index fine particles and low refractive index fine particles.
The high refractive index fine particles are not particularly limited, and for example, aromatic rings and sulfur are used in resin materials such as aromatic polyimide resins, epoxy resins, (meth) acrylic resins (acrylates and methacrylate compounds), polyester resins and urethane resins. Examples thereof include fine particles made of a resin having a high refractive index containing an atom or a bromine atom and a material having a high refractive index such as a precursor thereof, or metal oxide fine particles or metal alkoxide fine particles.
The low refractive index fine particles are not particularly limited, and for example, a resin having a low refractive index containing a fluorine atom in a resin material such as an epoxy resin, a (meth) acrylic resin, a polyester resin, and a urethane resin, and a precursor thereof. Examples thereof include fine particles made of a material having a low refractive index, magnesium fluoride fine particles, hollow or porous fine particles (organic or inorganic), and the like.

Examples of the method for forming the conductive layer include a method of laminating the conductive layer by a normal coating method, a method of laminating an overcoat layer on the conductive layer at a level at which a desired resistance value is obtained, and a release film. Examples thereof include a method having a transfer step of transferring the conductive layer to the hard coat layer which is a transfer material by using a transfer film having at least the conductive layer on the top. In order to lower the resistance value of the conductive layer of the present invention, it is preferable to produce the conductive layer by a method having a transfer step of transferring the conductive layer to the transferred body.
In the transfer step, a transfer film having at least a conductive layer on the release film is used.

Since the laminated body for a touch panel of the present invention has the above-mentioned structure, it can have extremely excellent foldability, and further has excellent hardness and transparency, and can be cracked or broken in a durable folding test. It does not occur, and it does not cause scratches even in the pencil hardness test.
Such a laminated body for a touch panel of the present invention can be used not only as a surface protective film for an image display device such as a liquid crystal display device or a touch panel as well as a hard coat film provided with a conventionally known hard coat layer, but also for a curved display. It can also be used as a surface protective film for products with curved surfaces and as a surface protective film for foldable members.
Among them, the laminated body for a touch panel of the present invention has extremely excellent foldability, and is therefore suitably used as a surface protective film for a foldable member.
Further, since the laminated body for a touch panel of the present invention is a member used for a touch panel, it is preferable that the laminated body has antibacterial properties. The method for imparting the antibacterial property is not particularly limited, and examples thereof include conventionally known methods.
Further, since it is a member used for a touch panel, it is preferable that the laminated body for a touch panel of the present invention has a blue light cut property by a conventionally known method. The blue light means light having a wavelength of 385 to 495 nm.

The foldable member is not particularly limited as long as it is a member having a foldable structure, and examples thereof include a foldable smartphone, a foldable touch panel, and a foldable (electronic) album. A foldable touch panel using the touch panel laminate of the present invention is also one of the present inventions.
The member having a foldable structure may be folded at one place or at a plurality of places. The folding direction can also be arbitrarily determined as needed.

Since the laminated body for a touch panel of the present invention has the above-mentioned structure, it has excellent hardness, transparency, and durable folding performance.
Therefore, the laminate for a touch panel of the present invention includes a surface protective film similar to a hard coat film provided with a conventional hard coat layer, a surface protective film for a product having a curved surface, a foldable image display device, and a touch panel. It can be suitably used as a surface material for a foldable member.

It is sectional drawing which shows typically the endurance folding test.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples and Comparative Examples.
In the text, "part" or "%" is based on mass unless otherwise specified.

(Example 1)
As a base film, a polyimide film having a thickness of 30 μm and represented by the above formula (1) is prepared, and the composition 1 for a hard coat layer having the following composition is applied and coated on one surface of the base film. A film was formed.
Next, the formed coating film is heated at 70 ° for 1 minute to evaporate the solvent in the coating film, and the ultraviolet rays are emitted into the air using an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H bulb). The coating film was half-cured by irradiation so that the integrated light amount was 100 mJ / cm ² , and a first hard coat layer having a thickness of 3 μm was formed.
Next, the composition A for a hard coat layer having the following composition was applied onto the first hard coat layer to form a coating film. Next, the formed coating film is heated at 70 ° for 1 minute to evaporate the solvent in the coating film, and the ultraviolet rays are converted into oxygen concentration using an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H valve). A second hard coat layer having a thickness of 2 μm is formed by irradiating the coating film with an integrated light amount of 200 mJ / cm ² under the condition of 200 ppm or less to completely cure the coating film, and a laminate for a touch panel is manufactured. did.

(Composition 1 for hard coat layer)
Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toa Synthetic Co., Ltd.) 25 parts by mass Dipentaerythritol EO modified hexaacrylate (A-DPH-6E, manufactured by Shin-Nakamura Chemical Co., Ltd.) 25 parts by mass Atypical silica fine particles (Average particle size 25 nm, manufactured by JGC Catalysts and Chemicals Co., Ltd.) 50 parts by mass (solid equivalent)
Photopolymerization initiator (Irg184) 4 parts by weight Fluorine-based leveling agent (F568, manufactured by DIC Corporation) 0.2 parts by weight (solid conversion)
Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained first hard coat layer was 830 MPa.

(Composition A for Hardcourt Layer)
Urethane acrylate (UX5000, manufactured by Nippon Kayaku Co., Ltd.) 25 parts by mass Dipentaerythritol Pentaacrylate and dipentaerythritol hexaacrylate mixture (M403, manufactured by Toagosei Co., Ltd.) 50 parts by mass Polyfunctional acrylate polymer (Acryt 8KX-012C, Taisei Fine Chemicals) (Manufactured by) 25 parts by mass (solid conversion)
Antifouling agent (BYKUV3500, manufactured by Big Chemie) 1.5 parts by mass (solid conversion)
Photopolymerization Initiator (Irg184) 4 parts by weight Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained second hardcoat layer was 500 MPa.

(Example 2)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the second hard coat layer was 4 μm.

(Example 3)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the first hard coat layer was 5 μm.

(Example 4)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the second hard coat layer was 0.75 μm.

(Example 5)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the first hard coat layer was 2 μm.

(Example 6)
It was carried out except that the composition 2 for the hard coat layer having the following composition was used instead of the composition 1 for the hard coat layer, and the composition B for the hard coat layer having the following composition was used instead of the composition A for the hard coat layer. A first hard coat layer and a second hard coat layer were formed in the same manner as in Example 1, and a laminate for a touch panel was manufactured.

(Composition 2 for hard coat layer)
Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toa Synthetic Co., Ltd.) 25 parts by mass 6-functional acrylate (MF001, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 25 parts by mass Atypical silica fine particles (average particle diameter 25 nm, JGC (Manufactured by JGC Catalysts and Chemicals) 50 parts by mass (solid conversion)
Fluorine-based leveling agent (F568, manufactured by DIC Corporation) 0.2 parts by weight (solid conversion)
Photopolymerization Initiator (Irg184) 4 parts by weight Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained first hardcoat layer was 890 MPa.

(Composition B for Hardcourt Layer)
Urethane acrylate (UX5000, manufactured by Nippon Kayaku Co., Ltd.) 50 parts by mass Mix of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toagosei Co., Ltd.) 50 parts by mass Antifouling agent (BYKUV3500, manufactured by Big Chemie) 1. 5 parts by mass (solid conversion)
Photopolymerization Initiator (Irg184) 4 parts by weight Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained second hardcoat layer was 600 MPa.

(Example 7)
It was carried out except that the composition 3 for the hard coat layer having the following composition was used instead of the composition 1 for the hard coat layer, and the composition C for the hard coat layer having the following composition was used instead of the composition A for the hard coat layer. A first hard coat layer and a second hard coat layer were formed in the same manner as in Example 1, and a laminate for a touch panel was manufactured.

(Composition 3 for hard coat layer)
Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toa Synthetic Co., Ltd.) 35 parts by mass Dipentaerythritol EO modified hexaacrylate (A-DPH-6E, manufactured by Shin-Nakamura Chemical Co., Ltd.) 35 parts by mass Atypical silica fine particles (Average particle size 25 nm, manufactured by JGC Catalysts and Chemicals Co., Ltd.) 30 parts by mass (solid equivalent)
Photopolymerization initiator (Irg184) 4 parts by weight Fluorine-based leveling agent (F568, manufactured by DIC Corporation) 0.2 parts by weight (solid conversion)
Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained first hard coat layer was 620 MPa.

(Composition C for Hardcourt Layer)
Urethane acrylate (KRM8452, manufactured by Dycel Ornex) 100 parts by mass antifouling agent (TEGO-RAD2600, manufactured by Evonik Japan)
1.5 parts by mass (solid conversion)
Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained second hard coat layer was 420 MPa.

(Example 8)
It was carried out except that the composition 4 for the hard coat layer having the following composition was used instead of the composition 1 for the hard coat layer, and the composition D for the hard coat layer having the following composition was used instead of the composition A for the hard coat layer. A first hard coat layer and a second hard coat layer were formed in the same manner as in Example 1, and a laminate for a touch panel was manufactured.

(Composition for Hardcourt Layer 4)
Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toagosei Corporation) 25 parts by mass 6-functional acrylate (MF001, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 10 parts by mass polyfunctional acrylate polymer (PVEEA, AX-4) -HC, manufactured by Nippon Catalyst Co., Ltd.)
15 parts by mass (solid conversion)
Photopolymerization initiator (Irg184) 4 parts by weight Atypical silica fine particles (average particle diameter 25 nm, manufactured by JGC Catalysts and Chemicals Co., Ltd.) 50 parts by mass (solid equivalent)
Fluorine-based leveling agent (F568, manufactured by DIC Corporation) 0.2 parts by weight (solid conversion)
Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained first hard coat layer was 800 MPa.

(Composition D for Hardcourt Layer)
Urethane acrylate (UV7600B, manufactured by Nippon Synthetic Chemical Co., Ltd.) 50 parts by mass Pentaerythritol triacrylate (M306, manufactured by Toagosei Co., Ltd.) 50 parts by mass Antifouling agent (X71-1203M) (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by mass (solid) Conversion)
Photopolymerization Initiator (Irg184) 4 parts by weight Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained second hardcoat layer was 600 MPa.

(Example 9)
It was carried out except that the composition 5 for the hard coat layer having the following composition was used instead of the composition 1 for the hard coat layer, and the composition E for the hard coat layer having the following composition was used instead of the composition A for the hard coat layer. A first hard coat layer and a second hard coat layer were formed in the same manner as in Example 1, and a laminate for a touch panel was manufactured.

(Composition 5 for hard coat layer)
Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (M403, manufactured by Toa Synthetic Co., Ltd.) 25 parts by mass Dipentaerythritol EO-modified hexaacrylate (A-DPH-6E, manufactured by Shin-Nakamura Chemical Co., Ltd.) 25 parts by mass Solid silica Fine particles (average particle diameter 12 nm, MIBKSD, manufactured by Nissan Chemical Co., Ltd.)
50 parts by mass (solid conversion)
Fluorine-based leveling agent (F568, manufactured by DIC Corporation) 0.2 parts by weight (solid conversion)
Photopolymerization Initiator (Irg184) 4 parts by weight Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained first hard coat layer was 730 MPa.
The solid silica fine particles were spherical solid silica fine particles.

(Composition E for Hardcourt Layer)
Urethane acrylate (UV7600B, manufactured by Nippon Gosei Co., Ltd.) 45 parts by mass Pentaerythritol triacrylate (M306, manufactured by Toagosei Co., Ltd.) 45 parts by mass Solid silica fine particles (average particle diameter 12 nm, MIBKSD, manufactured by Nissan Chemical Industries, Ltd.) 10 parts by mass Antifouling Agent (Optur DAC, manufactured by Daikin Industries, Ltd.) 0.5 parts by mass (solid conversion)
Photopolymerization Initiator (Irg184) 4 parts by weight Solvent (MIBK) 150 parts by mass The Martens hardness of the obtained second hardcoat layer was 500 MPa.

(Example 10)
A laminate for a touch panel was produced in the same manner as in Example 1 except that the thickness of the base film was 50 μm.

(Example 11)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the first hard coat layer was 5 μm and the thickness of the second hard coat layer was 4 μm.

(Example 12)
A laminate for a touch panel was produced in the same manner as in Example 1 except that the thickness of the base film was 20 μm.

(Example 13)
As the base film, the same as in Example 1 except that the polyimide film represented by the above formula (2) having a thickness of 30 μm was used instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. The laminate for the touch panel was manufactured.

(Example 14)
As the base film, the same as in Example 1 except that the polyimide film represented by the above formula (3) having a thickness of 30 μm was used instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. The laminate for the touch panel was manufactured.

(Example 15)
As the base film, the same as in Example 1 except that the polyimide film represented by the above formula (8) having a thickness of 30 μm was used instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. The laminate for the touch panel was manufactured.

(Example 16)
As the base film, the same as in Example 1 except that the polyimide film represented by the above formula (9) having a thickness of 30 μm was used instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. The laminate for the touch panel was manufactured.

(Example 17)
As the base film, instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm, an aramid film represented by the above formula (20) having a thickness of 30 μm (product name: Mictron, manufactured by Toray Industries, Inc.) is used. A laminate for a touch panel was manufactured in the same manner as in Example 1 except that it was used.

(Comparative Example 1)
As the base film, a triacetyl cellulose film (TAC, manufactured by Fujifilm Co., Ltd.) having a thickness of 25 μm was used instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. A laminate for a touch panel was manufactured in the same manner.

(Comparative Example 2)
Same as Example 1 except that a polyethylene terephthalate film (PET film, manufactured by Toray Industries, Inc.) having a thickness of 50 μm was used as the base film instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. To manufacture a laminated body for a touch panel.

(Comparative Example 3)
As the base film, a polyethylene naphthalate film (PEN film, manufactured by Teijin Limited) having a thickness of 30 μm was used instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. A laminate for a touch panel was manufactured in the same manner.

(Comparative Example 4)
Same as Example 1 except that a cycloolefin film (COP, manufactured by Nippon Zeon Corporation) having a thickness of 25 μm was used as the base film instead of the polyimide film represented by the above formula (1) having a thickness of 30 μm. The laminate for the touch panel was manufactured.

(Comparative Example 5)
The curing condition of the first hard coat layer was set to 200 mJ / cm ² by using an ultraviolet irradiation device (Fusion UV System Japan Co., Ltd., light source H bulb) under the condition that the oxygen concentration was 200 ppm or less. A laminate for a touch panel was produced in the same manner as in Example 1 except that the coating film was cured by irradiating the mixture so as to be.

(Reference example 1)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the first hard coat layer was 10 μm.

(Reference example 2)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the second hard coat layer was not provided.

(Reference example 3)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the thickness of the first hard coat layer was 2 μm and the thickness of the second hard coat layer was 10 μm.

(Reference example 4)
A laminate for a touch panel was produced in the same manner as in Example 11 except that the thickness of the base film was 100 μm.

(Reference example 5)
A laminate for a touch panel was manufactured in the same manner as in Example 1 except that the first hard coat layer was not provided and the thickness of the second hard coat layer was 3 μm.

The following evaluations were performed on the touch panel laminates obtained in Examples and Comparative Examples. The results are shown in Table 2.

(Durable folding test)
A sample prepared by cutting a touch panel laminate according to Examples and Comparative Examples (hereinafter, the side surface on which the hard coat layer is formed is the front surface and the opposite side surface is the back surface) into a rectangle of 30 mm × 100 mm is prepared. , Attached to a durability tester (DLDMLLH-FU, manufactured by Yuasa System Equipment Co., Ltd.) so that the bending radius is 1.5 mm (diameter 3.0 mm), and the entire surface of the surface on which the hard coat layer of the sample is formed is covered. A 180 ° folding test (a test of folding so that the back surface is on the outside) was performed 100,000 times. After that, it was replaced with a new sample, and a test of folding the entire surface of the side surface opposite to the side on which the hard coat layer of the new sample was formed by 180 ° (a test of folding so that the surface was on the outside) was performed 100,000 times, and the following was performed. Evaluated by criteria.
◯: No cracks occurred in the sample even when the above test was performed on both sides Δ: When the above test was performed so that the back surface was on the outside, no cracks were generated in the sample, but the front surface was The sample cracked when it was performed so as to be on the outside. ×: The sample cracked regardless of whether the above test was performed on the front surface or the back surface.

(Pencil hardness)
The pencil hardness of the touch panel laminate according to Examples and Comparative Examples was measured based on JIS K5600-5-4 (1999).

(Steel wool (SW) resistance)
A load of 1 kg / cm ² was applied to the outermost surface of the hard coat layer of the touch panel laminate according to the examples and comparative examples using # 0000 steel wool (trade name: BON STAR, manufactured by Nippon Steel Wool Co., Ltd.). While applying the material, the material was rubbed back and forth 3500 times at a speed of 50 mm / sec, and then the presence or absence of scratches on the surface of the hard coat layer was visually observed and evaluated according to the following criteria.
○: No scratches ×: There were scratches

(Total light transmittance)
The total light transmittance (%) was measured according to JIS K-7361 using a haze meter (manufactured by Murakami Color Technology Laboratory, product number; HM-150).

As shown in Table 2, the touch panel laminates according to Examples 1 to 17 were excellent in durable folding performance, scratch resistance and transparency, and had a very excellent pencil hardness of 5H or more.
Further, when the laminated body for the touch panel according to any of the examples was observed with a cross-sectional microscope, it was confirmed that the material component of the base film was eluted into the first hard coat layer.
On the other hand, the laminate for the touch panel according to Comparative Examples 1 to 4 in which the polyimide film or the aramid film was not used as the base film was inferior in pencil hardness, and when observed with a cross-sectional microscope, it was found in the first hard coat layer. Elution of the material components of the substrate film into the substrate film was not confirmed.
Further, the touch panel laminate according to Comparative Example 5 was inferior in durable foldability because the adhesion between the first hard coat layer and the second hard coat layer was poor.
In addition, Reference Example 1 in which the first hard coat layer was too thick, Reference Example 2 in which the second hard coat layer was not formed, Reference Example 3 in which the second hard coat layer was too thick, and Reference in which the base film was too thick. In the touch panel laminate according to Example 4, cracks did not occur when the endurance folding test was performed so that the back surface was on the outside, but cracks occurred when the durability folding test was performed so that the front surface was on the outside. rice field.
Further, in Reference Example 2 in which the second hard coat layer was not formed, the scratch resistance was also inferior.
Further, in Reference Example 5 in which the first hard coat layer was not formed, the pencil hardness was inferior.

The laminated body for a touch panel of the present invention can be suitably used as a surface material for a foldable image display device or a touch panel.

10 Laminated body for touch panel 11 of the present invention Upper fixing portion 12 Lower fixing portion

Claims (9)

A laminate for a touch panel, which is used as a surface material for a touch panel and has a base film and at least one cured resin layer.
An elution layer is formed in the range from the interface on the resin cured layer side of the base film to 300 nm in the thickness direction of the base film.
The resin cured layer contains a material component constituting the base film eluted from the elution layer.
The base film is a polyimide film or an aramid film.
The resin cured layer has a first hard coat layer provided on the base film side and a second hard coat layer provided on the side surface of the first hard coat layer opposite to the base film side. death,
The thickness of the first hard coat layer is 2.0 μm or more and 5.0 μm or less, and the thickness of the second hard coat layer is 0.5 μm or more and 4.0 μm or less.
The Martens hardness at the center of the cross section of the first hard coat layer is 500 MPa or more and less than 1000 MPa, and the Martens hardness at the center of the cross section of the second hard coat layer is 350 MPa or more and 600 MPa or less.
The value of the pencil hardness test (750 g load) specified in JIS K5600-5-4 (1999) of the resin cured layer is 5H or more.
When the resin cured layer does not have an uneven shape on the surface opposite to the base film side, the total light transmittance is 85% or more, and the resin cured layer is the surface opposite to the base film side. When the film has an uneven shape, the total light transmittance is 80% or more.
A touch panel laminate characterized in that cracks or breaks do not occur when the test of folding the entire surface of the touch panel laminate by 180 ° at intervals of 3 mm is repeated 100,000 times on both sides of the touch panel laminate. .. The laminate for a touch panel according to claim 1, wherein the base film is a polyimide film, and the raw material of the polyimide film has a structure represented by the following formula (1).

In the above equation (1), n is a repeating unit and represents an integer of 2 or more. The laminate for a touch panel according to claim 1 or 2, wherein the base film has a thickness of 10 to 55 μm. The second hard coat layer contains a cured product of a polyfunctional (meth) acrylate monomer as a resin component, and the first hard coat layer contains a cured product of a polyfunctional (meth) acrylate as a resin component and is described above. (1) The laminate for a touch panel according to claim 1, 2 or 3 , which contains silica fine particles dispersed in the resin component of the hard coat layer. The laminate for a touch panel according to claim 4 , wherein the silica fine particles are reactive silica fine particles. The laminate for a touch panel according to claim 1, 2, 3, 4 or 5 , wherein the resin cured layer has an uneven shape on the surface opposite to the base film side. The laminate for a touch panel according to claim 1, 2, 3, 4, 5 or 6 , which further has antifouling performance. The laminate for a touch panel according to claim 1, 2, 3, 4, 5, 6 or 7 , further comprising a conductive layer. A foldable image display device according to claim 1, wherein the laminated body for a touch panel according to claim 1, 2, 3, 4, 5, 6, 7 or 8 is used.

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