KR101949558B1 - Optical laminate and method for manufacturing thereof - Google Patents

Abstract

An object of the present invention is to provide an optical laminate and a method for producing the optical laminate in which the function is more strongly expressed in a small number of manufacturing steps and regardless of the kind of the functional component contained in the resin layer.
A method for producing an acrylic resin composition, comprising: a coating step (A) of applying an ionizing radiation curable resin composition A containing at least a functional component on an acrylic base material to form an uncured resin layer; (B) for reducing the thickness of the resin layer (B) by 1.0 to 15.0%, and a curing step (C) for curing the uncured resin layer by irradiating ionizing radiation to form a resin layer in this order, A method of producing an optical laminate characterized by causing a functional component to be localized on the surface side, and a method for manufacturing an optical laminate comprising a resin layer on an acrylic base material and a functional component distributed on the surface side of the resin layer.

Description

[0001] OPTICAL LAMINATE AND METHOD FOR MANUFACTURING THEREOF [0002]

The present invention relates to an optical laminate and a manufacturing method thereof.

BACKGROUND ART In an image display apparatus, a liquid crystal display (LCD), an LCD equipped with a touch panel, an electroluminescence (EL), an electronic paper and the like have characteristics such as power saving, CRT) display, it is becoming popular recently.

The optical laminate to be used on the surface or the inside of such an image display device has a hard coat property for preventing scratches during handling, antistatic property for eliminating the influence of static electricity, Antistatic property for preventing reflection of external light, and the like, it is necessary to provide a hard coat layer, an antistatic layer, a stain-resistant layer, an antiglare layer, an antireflection layer, and the like on the light- They are generally formed by a single function or a combination of functions.

For example, in an LCD, a polarizing element is disposed on an image display surface side of a liquid crystal cell, and a hard coat film having the functional layer formed on a light transmitting substrate is used as a polarizing plate protective film, Is generally given.

Conventionally, a film containing cellulose ester represented by triacetyl cellulose (TAC) has been used as a light-transmitting base material of such a hard coat film. This is because the case where the cellulose ester has excellent transparency and optical isotropy and has almost no retardation (low retardation value) in the plane is so small that the direction of vibration of the incident linearly polarized light is not very changed and the display quality of the liquid crystal display Is less affected by the effect of the. Further, since the cellulose ester has adequate water permeability, the moisture remaining in the polarizer and the moisture remaining in the adhesive layer of the optical laminate and the polarizing plate are dried through the optical laminate when the polarizing plate using the optical laminate is produced And the like.

On the other hand, in the case where a cellulose ester film is used as a transparent substrate, a method of applying a composition containing an antistatic agent to an ultraviolet curable resin to the transparent substrate and curing the function to give a hard coat property and antistatic property It is known. Further, there is known a method in which a function is imparted by coating a transparent base material with a composition containing an inorganic fine particle having a high hardness and an antistatic agent in a binder and curing the composition.

On the other hand, for example, Patent Document 1 discloses a method of uniformalizing a functional component in a hard coat layer. This is a method for more effectively expressing the function of the functional ingredient by causing the functional ingredient to be uneven on the surface. Specifically, the functional particles are surface-treated to control the hydrophilicity, degree of hydrophobicity, surface energy, etc. will be. However, this method is troublesome and disadvantageous in terms of cost because it requires special treatment, and there is a problem that the range of material selection is narrow and the manufacturing conditions are restricted.

Japanese Patent Application Laid-Open No. 2007-133236

It is an object of the present invention to provide an optical laminate having a function which is manifested in a small number of manufacturing steps and regardless of the kinds of functional components contained in the resin layer, and a method for producing the same.

Means for Solving the Problem As a result of intensive researches for solving the above problems, the present inventors have found that in order to achieve the above object, the present inventors have found that, in place of a cellulose ester film, an acrylic film is used as a transparent substrate, It has been found that a coating liquid for dissolving the acrylic film is used as a coating for forming a layer and constituting the resin layer and that the functional component is easily unevenly distributed depending on the degree of dissolution. As a result, it has been found that the optical laminate can be provided with a small number of manufacturing steps and in which the function is more strongly expressed regardless of the kind of the functional component contained in the resin layer.

The present invention provides the following inventions [1] to [3].

(1) A method for producing an acrylic resin composition, comprising: a coating step (A) of applying an ionizing radiation curable resin composition A containing at least a functional component on an acrylic base material to form an uncured resin layer; , A thickness reducing step (B) for reducing the thickness of the acrylic base material by 1.0 to 15.0%, and a curing step (C) for curing the uncured resin layer by irradiation with ionizing radiation to form a resin layer in this order, And the functional component is localized on the surface side of the resin layer.

[2] The method for producing an optical laminate according to the above [1], wherein the ionizing radiation curable resin composition A comprises a polyalkylene glycol di (meth) acrylate.

(3) A method for producing an acrylic resin composition, comprising the steps of: (A) applying an ionizing radiation curable resin composition A containing a functional component onto an acrylic base material to form an uncured resin layer; (B) for reducing the thickness of the substrate by 1.0 to 15.0%, and a curing step (C) for curing the uncured resin layer to form a resin layer in this order, And the component is localized.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an optical laminate in which functions are more strongly expressed in a small number of manufacturing steps and regardless of the kinds of functional components contained in the resin layer, and a method for producing the same.

Specifically, by employing the production method of the present invention, there is no need to perform special treatment on the functional particles, which widens the range of material selection, relaxes the constraints of the production conditions, and eliminates the need for special treatment steps. In addition, the function can be expressed more stably, inexpensively, and can be given a wide range of functions regardless of the kinds of the functional components contained in the resin layer in a small manufacturing process.

Further, by using the method of the present invention, besides the object of the present invention, the following effects are obtained.

(1) By using an acrylic base material having good moisture and heat resistance in place of the cellulose ester film, the polarizing plate functions in polarizing function and color polarizing plate function in a high temperature and high humidity environment developed in a polarizing plate using a cellulose ester film, Can be improved. In addition, the acrylic base material is inexpensive as compared with the cellulose ester film and is easily available in the market, so that the manufacturing cost can be further reduced.

(2) The optical laminate in which a resin layer such as a hard coat layer is formed on one side or both sides of an acrylic base material has the disadvantage that adhesion between the base material and the resin layer is inferior to that in the case of using a cellulose film base. However, in the optical laminate of the present invention, by using the coating liquid containing the binder for dissolving the acrylic base material as the coating liquid constituting the resin layer, the components of the acrylic base material are eluted into the resin layer, So that the adhesion between the acrylic base material and the resin layer can be improved. Further, when the component of the acrylic base material is eluted into the resin layer, the functional component of the resin layer is localized on the surface of the resin layer, so that the surface property based on the functional component can be imparted.

(3) In general, an optical laminate in which a resin layer such as a hard coat layer is formed on one side or both sides of an acrylic base material has a refractive index difference between the acrylic base and the resin layer, and a polarizing plate or the like is formed In this case, interference fringes are generated and appearance defects are caused. However, in the optical laminate of the present invention, since the component of the acrylic base material is eluted into the resin layer as described above, the change of the refractive index at the interface between the acrylic base and the resin layer is relaxed, The appearance defects can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a photograph showing a scanning electron microscope (STEM) showing a cross section of an optical laminate obtained by the method of producing an optical laminate of Example 1. Fig.
Fig. 2 is a photograph showing a scanning electron microscope (STEM) showing a cross section of an optical laminate obtained by the method for producing an optical laminate of Comparative Example 2. Fig.
3 is a partially enlarged photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical laminate obtained by the method for producing an optical laminate of Example 18. Fig.
4 is a partial enlarged photograph of a scanning transmission electron microscope (STEM) showing a cross section of a resin layer of an optical laminate obtained by the manufacturing method of the optical laminate of Example 18, from the surface side of the resin layer to the acrylic substrate side Fig.
5 is a partial enlarged photograph of a scanning transmission electron microscope (STEM) showing a cross section of a resin layer of the optical laminate obtained by the production method of the optical laminate of Comparative Example 9, from the surface side of the resin layer to the acrylic substrate side Fig.

A manufacturing method of the present invention is a manufacturing method comprising: a coating step (A) of applying an ionizing radiation curable resin composition A containing at least a functional component on an acrylic base material to form an uncured resin layer; (B) for reducing the thickness of the acrylic base material by 1.0 to 15.0% by dissolving the base material, and a curing step (C) for curing the uncured resin layer by irradiating with ionizing radiation to form a resin layer, , The functional component is localized on the surface side of the resin layer.

In the present invention, at least the above-mentioned steps (A) to (C) are performed in this order. However, different steps may be included among the respective steps within the range of achieving the effect of the present invention.

Hereinafter, each step will be described in detail.

(A) process and (B) process

The step (A) in the production method of the present invention is a coating step of forming an uncured resin layer by applying an ionizing radiation curable resin composition A containing a functional component on an acrylic base material, and the step (B) Is a thickness reducing process for dissolving an acrylic base material by an uncured resin layer to reduce the thickness of the acrylic base material by 1.0 to 15.0%.

1 is a photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical laminate obtained by the method of producing an optical laminate of Example 1. Fig. 2 is a photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical laminate obtained by the method for producing an optical laminate of Comparative Example 2. Fig. (Example 1), the thickness of the acrylic base material was reduced by 3 占 퐉 (7.5%) while the acrylic base material having a thickness of 40 占 퐉 was used in both of Example 1 and Comparative Example 2. In contrast, ) Indicates that the thickness of the acrylic base material is not substantially reduced.

<Acrylic substrate>

The acrylic resin contained in the acrylic base material is not particularly limited. For example, the acrylic resin is preferably one obtained by polymerizing one or more (meth) acrylic acid alkyl esters in combination, and more specifically, using (meth) .

An acrylic resin having a lactone ring structure or an acrylic resin having an imide ring structure may be used. This resin will be described later in detail.

The optical laminate of the present invention has an excellent heat and humidity resistance as well as a wrinkle can be appropriately prevented as compared with a base material including a TAC including an acrylic resin. In the present specification, &quot; acrylic resin &quot; means acrylic type and / or methacryl type.

In the present invention, it is essential to reduce the thickness of the acrylic base material by 1.0 to 15.0% by dissolving the acrylic base material by the uncured resin layer in the thickness reducing step (B) to be described later in detail. That is, in the acrylic base material of the present invention, the acrylic resin constituting the acrylic base material is corroded by the ionizing radiation curable resin composition A containing the functional component, especially by the solvent contained in the resin composition A, The acrylic resin is eluted into the uncured resin layer, thereby reducing the thickness of the acrylic base material.

If the reduction ratio of the thickness of the acrylic base material in the thickness reducing step (B) is less than 1.0%, the components in the acrylic base material do not sufficiently migrate to the resin layer, so that the functional components in the resin layer can not be localized on the surface, The adhesion between the substrate and the resin layer can not be improved, and interference fringes can not be prevented. In addition, in the thickness reducing step (B), if the reduction rate of the thickness of the acrylic base material exceeds 15.0%, the strength of the acrylic base material is insufficient and the base material is cracked in the thickness reducing step (B) Throw away.

The reduction rate of the thickness of the acrylic base material in the thickness reducing step (B) is preferably 3.0 to 13.0%.

Whether or not the thickness of the acrylic base material has decreased in the thickness reducing step (B) may literally be measured before and after the thickness reducing step (B). For example, even after the thickness reducing step (B) Can be confirmed by comparing the thickness of the acrylic base material where the ionizing radiation curable resin composition A is not applied and the thickness of the acrylic base material where the ionizing radiation curable resin composition A is coated. When thickness irregularity of the acrylic base material before the thickness reducing step (B) is significant, it is preferable to compare the thicknesses of the acrylic base material of the coated portion with the acrylic base material of the non-coated portion at relatively close positions.

In the present invention, the thickness of the acrylic substrate after the thickness reducing step (B) refers to an average value of a width of 30 占 퐉 of a photograph of a scanning transmission electron microscope (STEM) showing a cross section of the optical laminate. For example, when the surface of the acrylic base material is rough as shown in Fig. 3, the average distance from the surface of the acrylic base material opposite to the resin base layer to the resin layer is calculated in the 30 占 퐉 width region of the photograph of the STEM, The average distance is defined as the thickness of the acrylic substrate after the reducing thickness step (B). Further, the thickness of the resin layer after the curing step (C) (the thickness of the layer in which the components of the resin layer and the components of the acrylic base material were integrated by melt-kneading and cured) in the 30 탆 width area of the STEM photograph, Is calculated, and the average distance is defined as the thickness of the resin layer.

The thickness of the acrylic base material is preferably 20 to 300 占 퐉, more preferably 30 to 200 占 퐉, and still more preferably 30 to 100 占 퐉. If the acrylic base material is 20 mu m or more, the base material is less likely to be cracked through the thickness reducing step (B), and becomes less likely to be curled after the curing step (C). When the acrylic base material is 300 m or less, the optical laminate of the present invention becomes thin, and optical characteristics such as light transmittance are excellent.

In the thickness reducing step (B), the thickness of the acrylic base after the resin layer formation is preferably reduced by 0.5 to 5.0 占 퐉, more preferably by 1.5 to 5.0 占 퐉, relative to the thickness of the acrylic base material before the resin layer is formed Do. If the range is reduced, the effects of the present invention described above can be more fully exhibited.

Further, the acrylic base material in the present invention is preferably a drawn acrylic base material. By using a drawn acrylic base material, the strength and dimensional stability of the base material can be improved.

Specific examples of the acrylic resin having the lactone ring structure include those described in, for example, JP-A-2000-230016, JP-A-2001-151814, JP-A-2002-120326, JP- -254544, Japanese Patent Laid-Open Publication No. 2005-146084, and the like.

The acrylic resin having the lactone ring structure preferably has a lactone ring structure represented by the following formula (1).

In formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or an organic group having 1 to 20 carbon atoms. In addition, the organic group may contain an oxygen atom.

The content of the lactone ring structure represented by the general formula (1) in the structure of the acrylic resin having the lactone ring structure is preferably from 5 to 90 mass%, more preferably from 10 to 70 mass%, still more preferably from 10 to 60 mass% , And most preferably from 10 to 50 mass%. When the content of the lactone ring structure represented by the above formula (1) is 5% by mass or more, heat resistance, solvent resistance and surface hardness are improved, and when it is 90% by mass or less, molding processability is improved.

The acrylic resin having the lactone ring structure preferably has a weight average molecular weight of 1,000 to 2,000,000, more preferably 5,000 to 1,000,000, still more preferably 10,000 to 5,000, and most preferably 50,000 to 500,000 . The weight average molecular weight of the acrylic resin having a lactone ring structure within the above range is preferable from the viewpoint of the effect of the present invention described above.

Examples of the acrylic resin having an imide ring structure include an acrylic resin having a glutarimide structure or an N-substituted maleimide structure. As the acrylic resin having a glutarimide structure, it is preferable to have a glutarimide structure represented by the following general formula (2).

In the general formula (2), R ⁴ and R ⁵ independently represent a hydrogen atom or a methyl group, and R ⁶ represents a hydrogen atom, a straight chain alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group or a phenyl group.

Such a glutarimide structure can be formed, for example, by imidizing a (meth) acrylic acid ester polymer with an imidizing agent such as methylamine. Here, "(meth) acryl" means "acryl" and "methacryl".

The acrylic resin having the N-substituted maleimide structure preferably has an N-substituted maleimide structure represented by the following formula (3).

In the above formula (3), R ⁷ and R ⁸ independently represent a hydrogen atom or a methyl group, and R ⁹ represents a hydrogen atom, a straight chain alkyl group having 1 to 6 carbon atoms, a cyclopentyl group, a cyclohexyl group or a phenyl group.

The acrylic resin having such an N-substituted maleimide structure in its main chain can be formed, for example, by copolymerizing N-substituted maleimide and (meth) acrylic acid ester.

The acrylic resin preferably has a glass transition point (Tg) of 100 to 150 ° C, more preferably 105 to 135 ° C, and even more preferably 110 to 130 ° C. When the glass transition temperature (Tg) of the acrylic resin is 100 占 폚 or more, it is difficult for the acrylic resin to be damaged by the solvent contained in the resin layer forming composition at the time of forming the resin layer. On the other hand, It is easy to form irregularities at the interface.

The acrylic base material may contain a resin other than the acrylic resin, but the proportion of the acrylic resin in the acrylic base material is preferably 80 mass% or more, more preferably 90 mass% or more.

The acrylic base material is produced, for example, by stretching a pellet (chip) containing an air-moistened acrylic resin in the longitudinal direction (film forming direction) while cooling it after the general melt extrusion and then stretching it in the transverse direction .

In the melt extrusion process, a screw having one axis, two axes, or two or more axes can be used, and the rotational direction, the number of rotations, and the melting temperature of the screw can be arbitrarily set.

The stretching is preferably performed so as to have a desired thickness after stretching. The drawing magnification is not limited, but is preferably 1.2 times or more and 4.5 times or less. The temperature and humidity at the time of stretching are arbitrarily determined. The stretching method may be a general method.

In order to prevent the acrylic base material from being adhered to the acrylic base material, a primer layer may be formed on at least one side of the acrylic base material before or after the stretching of the acrylic base material, or nulling may be provided on both sides of the acrylic base material.

The acrylic base material may include acrylic rubber particles, an antioxidant, an ultraviolet absorber, a plasticizer and the like. The acrylic rubber particles can easily prevent cracking of the acrylic base material.

In the present invention, the acrylic base material is subjected to surface treatment such as saponification treatment, glow discharge treatment, corona discharge treatment, plasma treatment, ultraviolet (UV) treatment and flame treatment within the range not deviating from the object of the present invention .

&Lt; Ionizing Radiation Curable Resin Composition A Containing Functional Component >

(Functional ingredient)

Examples of the functional component include those used in conventional optical sheets such as antistatic agents, refractive index adjusting agents, antifouling agents, slip agents, antireflective agents, antistatic agents, hard coatability-imparting agents and antiblocking agents.

The antistatic agent may be organic or inorganic. Examples of the organic antistatic agent include ionic compounds such as lithium ion salts, quaternary ammonium salts and ionic liquids, and ionic compounds such as polythiophene, polyaniline, polypyrrole, poly And electron conductive ones such as acetylene. Examples of the inorganic material include metal oxides such as ATO, ITO, PTO, GZO, antimony pentoxide and zinc oxide, silver nanowires, carbon nanotubes, and fullerenes.

As the refractive index adjusting agent, inorganic materials such as hollow silica, solid silica, magnesium fluoride, and sodium fluoride, and fluorine-based materials such as fluorine-containing monomers, oligomers, and polymers can be given as the low refractive index material. Examples of the high refractive index material include inorganic materials such as zirconium oxide, titanium oxide, ATO, ITO, PTO, GZO and antimony pentoxide, organic materials containing chlorine, halogens other than fluorine (bromine and iodine atoms) A benzene ring skeleton or a naphthalene skeleton, an organic material having at least one anthracene skeleton in the molecule, and a carbazole material.

Examples of the antifouling agent include a fluorine resin, a silicone resin, a fluorine-silicone copolymer resin, and a fluorine- and silicon-free surfactant. Examples of the slip agent include a fluorine-based resin, a silicone-based resin, and a fluorine-silicone copolymer resin.

As the antireflection agent, there can be mentioned the above-mentioned low refractive index material.

Examples of the dispersant include silica particles, acrylic particles, melamine particles, benzoguanamine particles, and silicone particles. Examples of hard coatability-imparting agents include fine solid fine particles such as silica and alumina, fine fine particles, fine chain fine particles, fine particles having protrusions (star candy fine particles), and the like.

Examples of the antiblocking agent include fine particles such as silica, acryl, styrene and alumina.

The content of the functional component is preferably in the range of 0.1 to 30 mass% as the antistatic agent, based on the total mass of the total solid content in the ionizing radiation curable resin composition A. The content of the refractive index adjusting agent is preferably in the range of 5 to 30% by mass with respect to the total mass of all solids in the ionizing radiation curable resin composition A. The content of the antifouling agent is preferably in the range of 0.01 to 5 mass% with respect to the total mass of all solids in the ionizing radiation curable resin composition A. The content of the slip agent is preferably in the range of 0.01 to 5% by mass with respect to the total mass of all solids in the ionizing radiation curable resin composition A. The blending agent is preferably in the range of 1 to 20 mass% with respect to the total mass of the total solid content in the ionizing radiation curable resin composition A. The hard coat property-imparting agent is preferably in the range of 5 to 40% by mass with respect to the total mass of all solids in the ionizing radiation curable resin composition A. The antiblocking agent is preferably in the range of 0.1 to 5 mass% with respect to the total mass of all the solids in the ionizing radiation curable resin composition A.

Further, as described below, in the present invention, since the functional component is unevenly distributed on the upper surface of the resin layer, the effect of the functional component can be exhibited with a smaller content.

In the optical laminate of the present invention, as shown in Figs. 3 and 4, since the functional component is unevenly distributed on the upper surface of the resin layer, the function of the functional component can be more strongly expressed. For example, when the resin layer of the optical laminate of the present invention contains an antistatic agent as a functional component, since the antistatic agent is localized on the surface side of the resin layer, the case where the same amount of the antistatic agent is uniformly dispersed In comparison, the antistatic performance is more strongly expressed.

Similarly, when the resin layer contains a defoaming agent, the projection is further prevented. When the resin layer contains a low refractive index agent, the reflectance is further lowered. When the hard coat property-imparting agent is contained, the hard coat performance is further improved .

In addition, when the resin layer is formed without dissolving the acrylic base material, as shown in Fig. 5, the functional component can not be distributed on the upper surface of the resin layer.

In the present invention, the mechanism by which the functional component is localized on the upper surface of the resin layer is estimated as follows. In other words, it is presumed that the acrylic-based material component dissolved in the volatile solvent, which will be described later, flows out to the resin layer to provide a force for pushing up the functional component to the upper layer.

Therefore, conventionally, in the case where the specific gravity is light relative to the resin component in which the functional component is a matrix, the functional component moves in the direction of the upper layer due to the difference in specific gravity. In the case of the present invention, however, , It is thought that the functional component can be distributed on the surface of the resin layer.

Particularly, when the functional component is a hydrophilic component such as a quaternary ammonium salt or a component having a low surface tension such as an antifouling agent or a slip agent, the functional component is liable to be unevenly distributed above the resin layer. In addition, when the functional component is more compatible with the resin of the resin layer than the acrylic resin in the acrylic base material, the functional component is likely to be unevenly distributed above the resin layer.

In addition, as described above, since the material component of the acrylic base material flows out to the resin layer, appropriate irregularities are generated at the acrylic base-resin layer interface to improve the adhesion between the acrylic base material and the resin layer, Since the distances are different, the interference fringe becomes unclear, and interference fringe prevention is improved.

In addition, since the functional component often differs in refractive index from acryl as the base material, if the functional component is uniformly dispersed in the resin layer, a refractive index difference occurs between the acrylic base and the resin layer, and interference fringes are likely to occur. On the other hand, in the optical laminate of the present invention, since the functional component is hardly present at the acrylic base-resin layer interface, it is possible to make it difficult to generate interference fringes caused by the refractive index difference.

(Ionizing radiation curable resin)

In the present specification, the ionizing radiation curable resin composition refers to an electron beam-curable resin composition or an ultraviolet ray curable resin composition. As the ionizing radiation curable resin, it is preferable to use a polyalkylene glycol di (meth) acrylate as a main component. Specifically, the content of the polyalkylene glycol di (meth) acrylate in the ionizing radiation curable resin is preferably 25 to 100% by mass, more preferably 50 to 100% by mass in terms of solid content.

The acrylic base material is also dissolved by the solvent, but the acrylic base material can be more easily dissolved by the synergistic action of the solvent and the polyalkylene glycol di (meth) acrylate. Further, the polyalkylene glycol di (meth) acrylate is apt to be mixed with the acrylic resin component. Therefore, by using a polyalkylene glycol di (meth) acrylate as the ionizing radiation curable resin, the functional component can be easily flattened above the resin layer.

Examples of the polyalkylene glycol di (meth) acrylate include polyethylene glycol di (meth) acrylate such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate and tetraethylene glycol di Polypropylene glycol di (meth) acrylate such as dipropylene glycol di (meth) acrylate and dibutylene glycol di (meth) acrylate, tributylene glycol di (meth) acrylate, tetrabutylene glycol di (Meth) acrylate, and polybutylene glycol di (meth) acrylate.

The polyalkylene glycol di (meth) acrylate preferably has a molecular weight of 180 to 1000, more preferably a molecular weight of 200 to 750, and particularly preferably a molecular weight of 220 to 450. When the molecular weight is within this range, the adhesion between the acrylic substrate and the resin layer and the prevention of interference streaking are excellent, and the functional component can be easily localized above the resin layer.

The ionizing radiation curable resin composition A preferably contains polyalkylene glycol di (meth) acrylate as a main component, but may contain other components to be described later. In addition, when a material having extremely different properties is mixed in the ionizing radiation curable resin composition A, a sea-island structure is formed when the component of the acrylic base material flows into the resin layer side in the thickness reducing step (B) . Therefore, when the ionizing radiation curable resin composition A is composed of two or more components, it is preferable to use materials having similar properties.

The ionizing radiation curable resin composition A may further contain monofunctional (meth) acrylate or trifunctional (meth) acrylate.

Specific examples of monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl Acrylates such as hexyl (meth) acrylate, phenyl (meth) acrylate, acryloylmorpholine, N-acryloyloxyethylhexahydrophthalimide, tetrahydrofurfuryl acrylate, isobornyl acrylate, (Meth) acrylate, ethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, and butylene glycol mono (meth) acrylate) or polyalkyl (Meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol mono (meth) acrylate, There may be mentioned rate, etc.), an alkylene glycol mono (meth) acrylate is particularly preferred.

Specific examples of the trifunctional (meth) acrylate include isocyanuric acid triacrylate, polyalkylene glycol tri (meth) acrylate (trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) And the like.

As monofunctional (meth) acrylate and trifunctional (meth) acrylate, modified compounds of propylene oxide (PO) and ethylene oxide (EO) of each compound may be used.

By using the monofunctional (meth) acrylate, the viscosity can be easily adjusted and the adhesion with the base material can be improved. Further, the monofunctional (meth) acrylate is easily mixed with the resin component in the acrylic base material, so that the functional component can be easily flattened above the resin layer.

When trifunctional (meth) acrylate is used, the hardness can be increased. On the other hand, the trifunctional (meth) acrylate tends to be difficult to mix with the resin component in the acrylic base material, and it may be difficult to flatten the functional component above the resin layer.

In the present specification, "(meth) acrylate" refers to methacrylate and acrylate.

The ionizing radiation curable resin composition A may further contain a photopolymerizable polymer, a photopolymerizable oligomer and other photopolymerizable monomers, and in the case of an ultraviolet curable resin composition, an initiator.

(Photopolymerizable polymer)

The photopolymerizable polymer preferably has a (meth) acryloyl group as the functional group. The number of the functional groups is preferably 10 to 250, more preferably 10 to 100, and still more preferably 10 to 50.

The weight average molecular weight of the photopolymerizable polymer is preferably 10,000 to 100,000, more preferably 12,000 to 40,000.

The blending amount of the photopolymerizable polymer in the ionizing radiation curable resin composition A is preferably 0 to 40% by mass, more preferably 0 to 30% by mass in terms of solid content.

(Photopolymerizable oligomer)

The photopolymerizable oligomer is preferably a bifunctional or higher functional group and preferably has a (meth) acryloyl group as the functional group. The number of the functional groups is preferably 2 to 30, more preferably 2 to 20, still more preferably 3 to 15 Do.

The weight average molecular weight of the photopolymerizable oligomer is preferably 1,000 to 10,000, more preferably 1,500 to 10,000.

The blending amount of the photopolymerizable oligomer in the ionizing radiation curable resin composition A is preferably 0 to 40% by mass, more preferably 0 to 30% by mass in terms of solid content.

(Other photopolymerizable monomer)

As other photopolymerizable monomer, those having one or two or more unsaturated bonds include a compound other than the (meth) acrylate described above and a (meth) acrylate having four or more functionalities. (Meth) acrylate include polyfunctional monomers such as monofunctional monomers such as styrene, methyl styrene and N-vinyl pyrrolidone, poly (meth) acrylate esters of polyhydric alcohols and the like . Examples of the tetrafunctional or higher (meth) acrylate include pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate and the like, and ethylene oxide (EO) And the like, and the like.

The refractive index and the hardness can be adjusted by these other photopolymerizable monomers.

The molecular weight of the photopolymerizable monomer is preferably 200 to 1,000, more preferably 250 to 750.

The blending amount of other photopolymerizable monomers in the ionizing radiation curable resin composition A is not particularly limited within the range of exhibiting the effects of the present invention, but is preferably 0 to 40 mass%, more preferably 0 to 30 mass% % Is more preferable.

(Initiator)

The initiator is not particularly limited and known ones can be used. Specific examples of the photopolymerization initiator include acetophenones, benzophenones, meihylbenzoyl benzoates,? -Amyl oxime esters, thioxanthones, Propiophenes, benzyls, benzoins, and acylphosphine oxides. Further, it is preferable to use a mixture of photosensitizer. Specific examples thereof include n-butylamine, triethylamine, poly-n-butylphosphine and the like.

As the photopolymerization initiator, when the photopolymerizable monomer / oligomer / polymer is a resin system having a radically polymerizable unsaturated group, the photopolymerization initiator may be selected from the group consisting of acetophenones, benzophenones, thioxanthones, benzoins, benzoin methyl ethers, Cyclohexyl-phenyl-ketone is particularly preferable from the viewpoint of compatibility with the ionizing radiation curable resin and yellowing. When the photopolymerizable monomer / oligomer / polymer has a cationic polymerizable functional group, examples of the photopolymerization initiator include aromatic diazonium salts, aromatic sulfonium salts, aromatic iodonium salts, metallocene compounds, benzoin sulfonic acid esters and the like. It is preferably used alone or as a mixture.

The content of the initiator in the ionizing radiation curable resin composition A is preferably 1 to 10% by mass with respect to the total mass of all the solid components. When the content of the initiator is 1% by mass or more, it is preferable from the viewpoint of the hardness of the resin layer in the optical laminate, and when it is 10% by mass or less, the resin deterioration due to the excess of the initiator remaining is suppressed, And the pencil hardness of the target resin layer or the surface of the hard coat layer described later can be obtained.

A more preferable lower limit of the content of the initiator is 2% by mass with respect to the total mass of the total solid content, and a more preferable upper limit is 8% by mass. When the content of the initiator is within this range, the curing is made more reliable.

(Solvent-drying type resin)

The ionizing radiation curable resin composition A may further contain a solvent-drying type resin. By using the solvent-drying type resin in combination, it is possible to effectively prevent coating defects on the coated surface. The above-mentioned solvent-drying resin refers to a resin such as a thermoplastic resin, which is added to adjust the solid content at the time of coating and is formed into a film by simply drying the solvent.

The solvent-drying resin is not particularly limited, and a thermoplastic resin can be generally used.

The thermoplastic resin is not particularly limited and examples thereof include thermoplastic resins such as styrene resin, (meth) acrylic resin, vinyl acetate resin, vinyl ether resin, halogen-containing resin, alicyclic olefin resin, polycarbonate resin, A polyester resin, a polyamide resin, a cellulose derivative, a silicone resin and a rubber or an elastomer. The thermoplastic resin is preferably amorphous and soluble in an organic solvent (in particular, a common solvent capable of dissolving a plurality of polymers or curable compounds). Particularly, styrene resins, (meth) acrylic resins, alicyclic olefin resins, polyester resins, cellulose derivatives (such as cellulose esters) and the like are preferable from the viewpoints of film formability, transparency and weather resistance.

(solvent)

It is preferable that the ionizing radiation curable resin composition A further contains a solvent.

This solvent is preferably selected so as to appropriately dissolve the acrylic base material. More specifically, as described above, it is preferable to select a solvent which reduces the thickness of the acrylic base material after the formation of the resin layer by 1.0 to 15.0% with respect to the thickness of the acrylic base material before the resin layer formation in the thickness reduction step (B) desirable.

However, unlike the conventional TAC substrate, acrylic base materials are dissolved by almost all kinds of solvents. Therefore, there is a case where the influence of the solvent is strong, and if the solubility is excessively strong, the optical laminate can not be produced due to cracking. Therefore, it is preferable to select the following solvents among the solvents. The solubility of the acrylic base material also affects the mass ratio of the solvent in the coating liquid and the drying temperature of the solvent. For this reason, it is preferable to select an appropriate one from the following solvents while considering the amount of the solvent used and the drying temperature.

As such a solvent, alcohols, ketones, aromatic hydrocarbons, glycols and the like are suitably used, and in the case of alcohol, lower alcohols such as methanol, ethanol, isopropanol and 1-butanol are preferable. Further, in each of the solvents other than alcohols, the greater the number of carbon atoms tends to be good, and the higher the rate of evaporation tends to be, the better. Specifically, methyl isobutyl ketone is used as the ketone, toluene as the aromatic hydrocarbon, and propylene glycol monomethyl ether as the glycol, and the mixed solvent may be used.

Particularly, in the present invention, since the compatibility with the resin is excellent, the application workability is excellent, and the specific irregular shape of the present invention is formed at the acrylic base-resin layer interface, and furthermore, , Especially methyl isobutyl ketone, isopropanol, and 1-butanol and propylene glycol monomethyl ether. With these solvents, the acrylic base material can be appropriately dissolved without cracking.

On the other hand, esters such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, and diacetone alcohol; Cellosolve; Ethers such as dioxane, tetrahydrofuran and propylene glycol monomethyl ether acetate; Aliphatic hydrocarbons such as hexane; Aromatic hydrocarbons other than toluene such as xylene; Dichloromethane, dichloroethane halogenated carbons; Cellosolve such as methylcellosolve, ethylcellosolve; Cellosolve acetate; Sulfoxides such as dimethyl sulfoxide: amides such as dimethylformamide and dimethylacetamide are preferably not used when tension is applied to the substrate, since the acrylic base may be excessively dissolved.

The content of the solvent in the ionizing radiation curable resin composition A is determined according to the kind of the solvent to be used and the drying temperature of the solvent within a range in which the acrylic base material is appropriately dissolved. The content of the above-mentioned preferable solvent is preferably 30 to 300 parts by mass, more preferably 100 to 220 parts by mass with respect to 100 parts by mass of the solid content of the ionizing radiation curable resin composition A. [

The acrylic base material-resin layer interface in the optical laminate of the present invention can be obtained by, for example, a method in which an acryl base material is appropriately dissolved by a solvent and a polyalkylene glycol di (meth) acrylate or the like having an appropriate molecular weight Permeates the acrylic substrate. In addition, when the component of the resin layer penetrates the acrylic substrate, on the contrary, when the material component of the acrylic base material is extruded toward the resin layer or the solvent volatilizes from the acrylic base to the air surface of the resin layer, The material component of the resin penetrates into the resin layer. As each component moves from the upper part to the lower part and from the lower part to the upper part, proper irregularities are generated at the interface, so that the adhesion is improved and interference fringe prevention is also improved.

(Preparation of ionizing radiation curable resin composition A)

The ionizing radiation curable resin composition A can be produced by any known method such as a paint shaker, a bead mill, a kneader, a mixer or the like without particular limitation as long as the respective components can be uniformly mixed.

(Application method)

The method of applying the ionizing radiation curable resin composition A on the acrylic base material in the coating step (A) is not particularly limited, and examples of the method include a spin coating method, a dipping method, a spraying method, a die coating method, a bar coating method , A gravure coating method, a roll coater method, a meniscus coater method, a flexo printing method, a screen printing method, and a bead coater method.

(Drying step)

Subsequently, if necessary, a drying step is carried out. The drying step may also reduce the thickness of the acrylic substrate, and in that case, the drying step becomes part of the (B) thickness reducing step.

The drying time in the drying step is preferably 20 seconds to 120 seconds, more preferably 40 seconds to 80 seconds. The drying temperature in the drying step is preferably 40 to 90 占 폚, more preferably 50 to 80 占 폚. If the drying temperature exceeds 100 ° C, even if a solvent having good solubility in acrylic is selected, penetration of the solvent or the like may increase and the substrate may be cracked. Therefore, even if any solvent is used, Lt; 0 &gt; C or less. For example, as described above, there is methylisobutylketone as a preferable solvent. However, if the drying temperature is 100 deg. C even with this solvent, the acryl base may be broken by applying a tensile force.

The minimum temperature may be as long as the solvent can be dried, and preferably 40 ° C or more. For example, in the case of methylisobutyl ketone, when the drying temperature is 30 ° C, curing with ultraviolet rays or the like is carried out in an insufficiently dried state. In this case, curing is not performed well and uncured portions are also generated. At this time, the adhesion may be lowered.

(C) Process

The step (C) in the production method of the present invention is a curing step of curing the uncured resin layer by irradiating with ionizing radiation to form a resin layer.

Examples of the ionizing radiation include irradiation with ultraviolet rays or electron beams.

Specific examples of the ultraviolet ray source include light sources such as ultrahigh pressure mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc lamp, black light fluorescent lamp, metal halide lamp and the like. A wavelength range of 190 to 380 nm can be used as the wavelength of ultraviolet rays.

Specific examples of the electron beam source in the electron beam irradiation include various types of electron beam accelerators such as a Cocross Walton type, a Bandegraft type, a resonant transformer type, an insulating core transformer type, or a linear type, a dinamitron type and a high frequency type.

The preferable film thickness of the resin layer (the thickness of the layer of the resin layer and the layer of the acryl base material formed by cementing together the acrylic base material) is 0.5 to 100 탆, more preferably 0.8 to 20 탆, Since the anti-blocking property is particularly excellent, it is most preferably in the range of 2 to 10 mu m.

&Lt; Optical laminate &

The optical laminate of the present invention comprises: an application step (A) of applying an ionizing radiation curable resin composition A containing a functional component on an acrylic base material to form an uncured resin layer; and a step (B) for reducing the thickness of the acrylic base material by 1.0 to 15.0%, and a curing step (C) for curing the uncured resin layer to form a resin layer in this order, Characterized in that the functional component is localized on the surface side of the stratum corneum.

Since the above-described various components can be used for the functional component, the optical laminate of the present invention can be constituted only by the acrylic base material and the resin layer.

On the other hand, the optical laminate of the present invention may have at least one selected from a low refractive index layer, a hard coat layer, a scattering layer, an antiglare layer, an antistatic layer and a high refractive index layer on a resin layer.

<Hard coat layer>

The hard coat layer preferably includes a cured product of the ionizing radiation curable resin composition B.

The hard coat layer preferably has a hardness of H or more and more preferably 2H or more in a pencil hardness test (load 4.9 N) according to JIS K5600-5-4 (1999). The hard coat layer may contain the above-mentioned functional components other than the hard coat property-imparting agent.

Details of the ionizing radiation curable resin composition B forming the hard coat layer are the same as those of the ionizing radiation curable resin composition A described above.

Further, in the ionizing radiation curable resin composition B, the blending amount of the photopolymerizable monomer (particularly, the polyfunctional monomer) is preferably 30 to 100 mass%, more preferably 40 to 90 mass%, based on the total mass of the total solid content , And more preferably 50 to 80 mass%.

In the ionizing radiation curable resin composition B, the total amount of the photopolymerizable oligomer and the photopolymerizable polymer is preferably 30 to 100% by mass, more preferably 40 to 90% by mass, based on the total mass of the total solid content , And more preferably 50 to 80 mass%.

The method of forming the hard coat layer is the same as the above-mentioned resin layer. The details of the other hard coat layers are the same as those of the resin layer described above.

In the present invention, it is preferable to laminate a hard coat layer on the resin layer. In order to obtain the hardness as the optical laminate, it is considered that the resin layer itself has a high hardness. However, when a material having a reactive functional group having a polyfunctional functional group is used directly on the acrylic base material, that is, the resin base layer has a hardness of 2H or more, the acrylic base material tends to be cracked, for example, when a partial pressure is applied to the hard coat layer . Therefore, in the optical laminate of the present invention, the impact of the hard coat layer is not directly transmitted to the acrylic base material because the resin layer is in contact with the hard coat layer, and the buffer layer has a buffering action. In addition, by using the resin layer / hard coat layer, it is possible to improve the hardness as compared with the case where only the hard coat layer is laminated.

However, when a hard coat layer or the like is laminated, a new interface is generated between the resin layer and the resin layer, that is, a portion where interference fringes are generated is increased. In this case, it is important that the refractive index of the layer to be laminated is as close as possible to the layer below it. Therefore, in order to maintain interference fringe prevention properties well, the refractive index of the hard coat layer is preferably approximately the same as the refractive index of the resin layer, and the preferable difference in refractive index is 0.03 or less.

<Low Refractive Index Layer>

The optical laminate of the present invention preferably further comprises a low refractive index layer on the hard coat layer.

Preferable examples of the low refractive index layer include 1) a resin containing low refractive index inorganic fine particles such as silica or magnesium fluoride, 2) a fluororesin as a low refractive index resin, and 3) a resin containing low refractive index inorganic fine particles such as silica or magnesium fluoride A fluorine resin, and 4) a low refractive index inorganic thin film such as silica or magnesium fluoride. As the resin other than the fluorine resin, the same resin as the above-mentioned acrylic resin can be used.

The above-mentioned silica is preferably hollow silica fine particles, and such hollow silica fine particles can be produced, for example, by the production method described in the embodiment of Japanese Patent Application Laid-Open No. 2005-099778.

These low refractive index layers preferably have a refractive index of 1.47 or less, particularly 1.42 or less. The thickness of the low refractive index layer is not limited, but may be suitably set within a range of usually about 10 nm to 1 m.

As the fluororesin, at least a polymerizable compound containing a fluorine atom in a molecule or a polymer thereof can be used. The polymerizable compound is not particularly limited, but preferably has a curing-reactive group such as a functional group which is cured by ionizing radiation or a polar group which is thermally cured. Further, a compound capable of simultaneously combining these reactive groups may also be used. With respect to the polymerizable compound, the polymer does not have any reactive group as described above.

As the polymerizable compound having a functional group which is cured by the above ionizing radiation, a fluorine-containing monomer having an ethylenic unsaturated bond can be widely used. More specifically, fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3 -Dioxol, etc.) can be exemplified.

Further, a fluorine-containing monomer having a (meth) acryloyloxy group may also be used. Specific examples include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluorobutyl) ethyl (Perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (meth) acrylate compounds having a fluorine atom in the molecule, such as methyl? -trifluoromethacrylate and ethyl? -trifluoromethacrylate.

Further, it is also possible to use, in the molecule, a fluorine-containing polyfunctional (meth) acrylate having at least three fluorine atom-containing fluoroalkyl groups, fluorocycloalkyl groups or fluoroalkylene groups each having 1 to 14 carbon atoms and at least two (meth) acryloyloxy groups ) Acrylic ester compounds.

Next, preferable examples of the polar group which is thermally cured include a hydrogen bond forming group such as a hydroxyl group, a carboxyl group, an amino group, and an epoxy group. These are excellent not only in adhesion to the coating film but also in affinity with inorganic ultrafine particles such as silica. As the polymerizable compound having a thermosetting polar group, for example, a 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; Fluoroethylene-hydrocarbon-based vinyl ether copolymers; Fluorine-modified products of various resins such as epoxy, polyurethane, cellulose, phenol, and polyimide.

Examples of the polymerizable compound having a polar group capable of being thermally cured by a functional group cured by the ionizing radiation include acrylic or methacrylic acid moieties and fully fluorinated alkyl, alkenyl, aryl esters, fully or partially fluorinated vinyl ethers, Partially-fluorinated vinyl esters, fully or partially fluorinated vinyl ketones, and the like.

Examples of the fluorine-based resin include the following.

A polymer of a monomer or monomer mixture containing at least one fluorine-containing (meth) acrylate compound of the polymerizable compound having an ionizing radiation curable group; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl Copolymers of (meth) acrylate compounds that do not contain fluorine atoms in the molecule such as acrylate; Fluoroethylene, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-trifluoropropylene, Homopolymers or copolymers of fluorine-containing monomers such as hexafluoropropylene. Silicon-containing vinylidene fluoride copolymers containing a silicone component in these copolymers may also be used. Examples of the silicone component in this case include (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, (poly) methylphenylsiloxane, alkyl modified (poly) dimethylsiloxane, azo group- A silicon-containing silicon, an alkoxy group-containing silicone, a phenol group-containing silicone, a methacryl-modified silicone, an alkylaryl-modified silicone, a fluoro silicone, a polyether-modified silicone, a fatty acid ester- , Acryl modified silicone, amino modified silicone, carboxylic acid modified silicone, carbinol modified silicone, epoxy modified silicone, mercapto modified silicone, fluorine modified silicone, polyether modified silicone and the like. Among them, those having a dimethylsiloxane structure are preferable.

Further, a non-polymer or a polymer containing the following compounds can also be used as the fluorine resin. A compound obtained by reacting a fluorine-containing compound having at least one isocyanato group in a molecule with a compound having at least one functional group reactive with an isocyanato group such as an amino group, a hydroxyl group or a carboxyl group in a molecule; A compound obtained by reacting a fluorine-containing polyol such as a fluorine-containing polyether polyol, a fluorine-containing alkylpolyol, a fluorine-containing polyesterpolyol and a fluorine-containing? -Caprolactone-modified polyol with a compound having an isocyanato group.

The composition for forming a low refractive index layer may contain the thermoplastic resin as described above together with the above-mentioned polymerizable compound or polymer having a fluorine atom. In addition, various additives and solvents can be suitably used to improve the curing agent for curing the reactive group or the like, the application workability, or the antifouling property.

In forming the low refractive index layer, the viscosity of the low refractive index layer forming composition is in the range of 0.5 to 5 mPa ((25 캜), preferably 0.7 to 3 mPa s (25 캜) . It is possible to form an excellent antireflection layer of visible light and to form a thin film which is uniform and free from coating irregularities and can form a low refractive index layer having particularly excellent adhesion.

The curing means of the resin may be the same as the curing means in the above-mentioned hard coat layer. When a heating means is used for the curing treatment, it is preferable that, for example, a thermal polymerization initiator which generates radicals to initiate polymerization of the polymerizable compound by heating is added to the composition for forming a low refractive index layer.

The optical laminate of the present invention preferably has a total light transmittance of 80% or more. If it is less than 80%, there is a fear that the color reproducibility and visibility may be impaired in the case of being mounted on the image display apparatus, and there is a possibility that the desired contrast may not be obtained. The total light transmittance is more preferably 90% or more.

The total light transmittance can be measured by a method in accordance with JIS K-7361 using a haze meter (Murakami Shikigi Co., Ltd., product number: HM-150).

The optical laminate of the present invention preferably has a haze of 1% or less. If it is 1% or less, desired optical characteristics are obtained, and there is no deterioration of visibility when the optical laminate of the present invention is formed on the image display surface.

The haze can be measured by a method in accordance with JIS K-7136 using a haze meter (Murakami Shikigi Co., Ltd., product number: HM-150).

The optical laminate of the present invention is useful as a polarizer, and is formed by laminating the optical laminate of the present invention on at least one side of a polarizing film.

The polarizing film is not particularly limited, and for example, a stretched polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl acetal film, an ethylene-vinyl acetate copolymerization system saponified film and the like can be used which are dyed with iodine or the like. In the lamination treatment of the polarizing film and the optical laminate, it is preferable to saponify the acrylic base material. By the saponification treatment, the adhesiveness is improved and an antistatic effect can be obtained.

The optical laminate of the present invention can be applied to an image display apparatus comprising the optical laminate and / or the polarizer.

Examples of the image display device include a television, a computer, an LCD, a PDP, an FED, an ELD (organic EL, inorganic EL), a CRT, a tablet PC, an electronic paper, a mobile phone, It can also be applied to panels.

The LCD, which is a typical example of the above, comprises a transmissive display body and a light source device for irradiating the transmissive display body from the back side. When the image display device using the optical laminate of the present invention is an LCD, a polarizing plate using the optical laminate of the present invention and / or the optical laminate of the present invention is formed on the surface of the transmissive display. However, in the case of an image display apparatus equipped with a touch panel, it can be used not only as a surface but also as a transparent substrate constituting the inside of the apparatus.

In the image display apparatus using the optical laminate of the present invention, the light source of the light source device is irradiated from the lower side of the optical laminate or the polarizing plate. Further, a phase difference plate may be inserted between the image display element and the polarizing plate. An adhesive layer may be formed between each layer of the image display apparatus, if necessary.

Here, when the image display apparatus using the optical laminate of the present invention is a liquid crystal display device, the backlight light source is not particularly limited, but it is preferable that the image display apparatus is a white light emitting diode (white LED) It is preferable that the liquid crystal display device is a VA mode or IPS mode liquid crystal display device having a white light emitting diode.

The white LED is a device that emits white light by combining a phosphor or a light emitting diode that emits blue light or ultraviolet light using a phosphor compound, that is, a compound semiconductor. Among them, a white light emitting diode including a light emitting element comprising a combination of a blue light emitting diode using a compound semiconductor and a yttrium aluminum garnet yellow phosphor has a continuous and broad emission spectrum, and therefore has improved antireflection performance and improved spot contrast And is also suitable as the backlight light source in the present invention because of its excellent luminous efficiency. In addition, since a white LED having a small power consumption can be widely used, the effect of energy saving can also be exhibited.

The VA (Vertical Alignment) mode is a mode in which the liquid crystal molecules are oriented so as to be perpendicular to the substrate of the liquid crystal cell when no voltage is applied, and the liquid crystal molecules are collapsed by application of a voltage, to be.

The IPS (In-Plane Switching) mode is a mode in which the liquid crystal is rotated in the plane of the substrate by the electric field in the horizontal direction applied to the interdigital electrode pairs provided on one substrate of the liquid crystal cell to perform display.

The PDP as the image display device has a surface glass substrate on which electrodes are formed on the surface, and a discharge gas is disposed in confrontation with the surface glass substrate, electrodes and minute grooves are formed on the surface, Green, and blue phosphor layers are formed on the rear glass substrate. When the image display apparatus of the present invention is a PDP, the above-described optical laminate may be provided on the surface of the surface glass substrate or on the front surface plate (glass substrate or film substrate) thereof.

The image display device includes an ELD device for depositing zinc sulfide, a substance of diamines, and a light emitting substance, which emit light when a voltage is applied, on a glass substrate and controlling the voltage applied to the substrate to perform display, Or an image display device such as a CRT for generating a visible image. In this case, the above-mentioned optical laminate is provided on the outermost surface of each display device or on the surface of the front surface plate.

[Example]

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited at all by this example.

(Assessment Methods)

The following evaluations were performed on the optical laminate produced in each of the Examples and Comparative Examples.

(1) Measurement of thickness of acrylic base material

The thickness of the acrylic base material after the thickness reducing step (B) and the thickness of the resin layer after the curing step (C) were calculated by the method described in the specification.

(2) Adhesion

On the basis of JIS K 5600, a total of 100 checkerboard eyes were formed in a square of 1 mm on each side in the hard coat layer of the optical laminate, and a 24 mm cellophane tape (registered trademark) for industrial use manufactured by Nichiban Co., Ltd. was used Five consecutive peeling tests were performed to measure the remaining number of the grids.

According to the number of ungrooved grids, the following evaluation was made. Level B or better is good as a product.

A: 90-100

B: 80-89

C: 50-79

D: less than 50

(3) Interference stripes

After a black tape was bonded to the surface of the optical laminate opposite to the hard coat layer, the presence or absence of interference fringe was visually observed under a three-wavelength tube fluorescent lamp. The acceptable product which can not recognize interference fringes is designated as A, the case where blurred visibility is possible is designated as C, and the case where visibility is visable is defined as D.

(4) Manufacturing processability

The ionic radiation-curable resin composition A was applied onto an acrylic base material and dried, thereby performing a tensile test. The degree of tension was 2.2 N / cm. As a result, it was evaluated as &quot; C &quot; when a case of not being broken when stretched was denoted by &quot; A &quot; In addition, since the physical properties of the substrate itself are weakened in the optical laminate in which the manufacturing processability becomes &quot; defective &quot;, the pencil hardness (JIS K5600-5-4) does not become 2H or more even if the resin layer or the hard coat layer is cured .

(5) Hayes

The haze value (%) of the optical laminate was measured in accordance with JIS K-7136 using a haze meter (Murakami Shikigui Co., Ltd., product number: HM-150) and evaluated according to the following evaluation criteria .

A: Haze value is 0.8 or less

C: Haze value exceeded 0.8

(6) Crack resistance

A tensile test was carried out using a tensile shear universal testing machine (RTG-1310 manufactured by A & D Co., Ltd.) to evaluate cracking resistance. The optical laminate was made into a sample having a width of 10 mm and a length of 100 mm, and was stretched at a rate of 100 mm / min with a tensilon and evaluated according to the following criteria.

A: Stronger than 15N, but not broken

C: Breaks below 15N

(7) Surface resistivity

The surface resistivity (? /?) Of the optical laminate containing the antistatic material in the resin layer was measured by using a surface resistivity meter (HiRester HT-210, manufactured by Mitsubishi Chemical Industry Co., Ltd.).

(8) Anti-blocking property (anti-adhesion property)

Two optical laminated bodies (optical laminated bodies of Example 21) containing an antiblocking agent in the resin layer were prepared and cut into a size of 5 cm x 5 cm each. The acrylic base side of one optical laminate and the resin layer side of the other optical laminate were stacked so as to face each other, and the laminate was closely contacted for 30 hours under the conditions of a pressure of 3.0 kgf / cm 2 and 50 ° C. Respectively.

A: No attachment

C: Attached

(9) Pencil Hardness

The pencil hardness of the surface on which the hard coat layer was formed was measured at a load of 4.9 N according to the pencil hardness evaluation method prescribed by JIS K5600-5-4 (1999) using a test pencil specified by JIS-S-6006 Respectively.

Example 1

(Preparation of acrylic substrate)

A pellet containing a copolymer of methyl methacrylate and methyl acrylate (glass transition point: 130 占 폚) was melted and kneaded, and the polymer was extruded from the gap of the die by a melt extrusion method while removing foreign matters through a filter. Subsequently, the polymer was stretched 1.2 times in the longitudinal direction while cooling the polymer, and then stretched 1.5 times in the transverse direction to obtain an acrylic base material having a thickness of 40 占 퐉.

(Preparation of ionizing radiation curable resin composition A)

80 parts by mass of tetraethylene glycol diacrylate ("M240", manufactured by Toagosei Co., Ltd., molecular weight: 286) was added, as a functional component, antimony doped tin oxide particles (methyl isobutyl ketone dispersion of ATO particles Mitsubishi Material Dicy , 4 parts by mass of an initiator (&quot; Irg184 &quot;, manufactured by BASF) were dissolved in 150 parts by mass of methyl isobutyl ketone (MIBK) Curable resin composition A was prepared. Table 1 shows the composition of the ionizing radiation curable resin composition A.

(Production of optical laminate)

An ionizing radiation-curable resin composition A was coated and formed on an acrylic substrate by a die coating method to form an uncured resin layer. The resultant was dried at 70 DEG C for 1 minute to evaporate the solvent, and a resin layer was formed so that the adhesion amount after drying was 5 g / m &lt; 2 &gt;. The resulting coating film was irradiated with ultraviolet rays at a dose of ultraviolet radiation of 200 mJ / cm 2 under a nitrogen atmosphere (oxygen concentration of 500 ppm or less) to completely cure the coating film (full cure state) to obtain an optical laminate. Table 1 shows the results of evaluation by the above evaluation method.

Examples 2 to 28, Comparative Examples 1 to 13

An optical laminate was obtained in the same manner as in Example 1 except that the ionizing radiation curable resin composition A, the drying temperature, and the deposition amount after drying were changed to the conditions of Tables 1 to 5. The evaluation results are shown in Tables 1 to 5 in the same manner as in Example 1.

(Materials used in Tables 1 to 5)

[Ionizing radiation curable resin]

TEGDA: tetraethylene glycol diacrylate ("M240" manufactured by Toagosei Co., Ltd., molecular weight: 286)

PETA: pentaerythritol triacrylate

[Other ionizing radiation curable resins]

A: Dipentaerythritol hexaacrylate

B: urethane acrylate, manufactured by Nippon Kogei Kagaku Kogyo Co., Ltd., "Zircon UV1700B"

[Functional Materials]

Antistatic agent a: ATO dispersion, manufactured by Mitsubishi Materials Denshi Chemical Industry &quot; EPT5DL 2MIBK &quot;

Antistatic agent b: Stretched ATO dispersion, manufactured by Nikkiso Co., Ltd., &quot; ELCOM V3560 &quot;

Antistatic agent c: antimony pentoxide dispersion, NIKKISOKUBA Kasei Co., Ltd., "ELCOM V4504"

Antistatic agent d: quaternary ammonium salt, trade name, &quot; Colcoat NR121X &quot;

Antistatic agent e: quaternary ammonium salt, manufactured by Daisepine Chemical Co., Ltd., 1SX3004

Antistatic agent f: Li ion-type antistatic agent, lithium bistrifluoromethanesulfonimide, Sumitomo 3M, LJ-603010

Reactive silica a: "MIBK-SDL" manufactured by Nissan Chemical Industries, Ltd., solid silica, average particle diameter 44 nm

Reactive silica b: NIKKISOKU Cubase KASEI Co., Ltd., modified silica, "ELCOM V8803", average particle diameter 25 nm

Anti-blocking agent: CIK Nanotek Co., solid silica, "E65", average primary particle diameter 150 to 300 nm

High refractive index material a: high refractive index urethane acrylate, manufactured by Dai-ichi Kogyo Seiyaku, &quot; R1403MB &quot;

High refractive index material b: high refractive index monofunctional monomer, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., "OPPE"

[solvent]

MIBK: methyl isobutyl ketone

IPA: Isopropyl alcohol

MEK: methyl ethyl ketone

PGME: Propylene glycol monomethyl ether

&Lt; Industrial applicability >

INDUSTRIAL APPLICABILITY The optical laminate of the present invention can be applied to a display such as a cathode ray tube display (CRT), a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), a touch panel, And can be suitably used for a high-definition display.

Claims (3)

(A) applying at least an ionizing radiation curable resin composition A containing a functional component on an acrylic base material having a thickness of 20 to 300 탆 to form an uncured resin layer; and (B) for reducing the thickness of the acrylic base material by 3.0 to 15.0%, and a curing step (C) for curing the uncured resin layer by irradiating with ionizing radiation to form a resin layer in this order And the functional component is localized on the surface side of the resin layer, thereby producing an optical laminate. The method according to claim 1,
Wherein the ionizing radiation curable resin composition A comprises a polyalkylene glycol di (meth) acrylate. (A) applying an ionizing radiation curable resin composition A containing a functional component on an acrylic base material having a thickness of 20 to 300 탆 to form an uncured resin layer, and a step (A) of dissolving the acrylic base material by the uncured resin layer (B) for reducing the thickness of the acrylic base material by 3.0 to 15.0%, and a curing step (C) for curing the uncured resin layer to form a resin layer in this order, And the functional component is unevenly distributed on the side of the optical layer.

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