TWI643740B - Optical laminate and manufacturing method of optical laminate - Google Patents

Abstract

The present invention provides an optical multilayer body having fewer manufacturing steps and exhibiting a stronger function regardless of the type of functional components contained in the resin layer, and a method for manufacturing the same.

The manufacturing method of the optical multilayer body of the present invention is characterized by sequentially performing the following steps: a coating step (A), which coats an acrylic based material with a free radiation-curable resin containing at least a functional component The composition A forms an unhardened resin layer; the step of reducing the thickness (B) is to dissolve the acrylic substrate by the unhardened resin layer and reduce the thickness of the acrylic substrate by 1.0 to 15.0%; and the hardening step (C ), Which is irradiated with free radiation to harden the unhardened resin layer to form a resin layer; thereby, the functional component is biased toward the resin layer surface side; and the optical laminated system of the present invention has a resin layer on an acrylic substrate , And the functional component is biased toward the surface side of the resin layer.

Description

Optical laminated body and manufacturing method thereof

The invention relates to an optical multilayer body and a method for manufacturing the same.

In image display devices, liquid crystal displays (LCDs), LCDs equipped with touch panels, electroluminescence (EL), electronic paper, etc. have features such as power saving, light weight, and thinness. CRT) displays are rapidly spreading.

Optical laminates used on the surface or inside of such image display devices require hard-coating properties that do not scratch during handling, anti-static properties to eliminate the effects of static electricity, and to eliminate the effects of fingerprint adhesion Poor appearance, anti-fouling properties, anti-glare properties to prevent reflection, anti-reflection properties to prevent reflection of external light, etc., so it is usually done by setting the hard Coatings, antistatic layers, antifouling layers, antiglare layers, antireflection layers, etc. provide functions.

For example, in an LCD, a polarizing element is arranged on the image display surface side of a liquid crystal cell. Usually, a hard coating film provided with the above-mentioned functional layer on a light-transmitting substrate is used as a polarizing plate protective film to display an image. Faces give various functions.

Previously, as the light-transmitting substrate of such a hard coating film, Vitamin (TAC) is a typical film made of cellulose ester. The reason is that cellulose ester has the following advantages: excellent transparency and optical isotropy, almost no phase difference in the plane (lower retardation value), so it rarely changes the vibration direction of incident linearly polarized light. The effect of display quality is less. In addition, cellulose ester also has the following advantages: it has moderate water permeability. Therefore, when manufacturing a polarizing plate made using an optical laminate, the optical laminate can be used to keep the moisture remaining in the polarizing element and the optical laminate. The moisture of the adhesive layer of the polarizing plate is dried.

On the other hand, in the case where a cellulose ester film is used as a transparent substrate, in order to impart hard coat properties and antistatic properties, it is known to apply a composition containing an antistatic agent to an ultraviolet curable resin. A method of applying a function to the transparent substrate and curing it. In addition, a method is known in which a composition comprising an inorganic fine particle having a relatively high hardness and an antistatic agent prepared by blending in an adhesive is applied to a transparent substrate and hardened to impart a function.

On the other hand, for example, Patent Document 1 discloses a method of biasing a functional component into a hard coat layer. This method is a method of more effectively expressing the function of the functional component by biasing the functional component toward the surface, and specifically, surface-treating the functional particles to control the degree of hydrophilicity or hydrophobicity. , Surface energy, etc. However, this method has the following problems: it is complicated due to the need for special treatment, and it is also disadvantageous in terms of cost, and the range of material selection is narrow, and the manufacturing conditions are restricted.

[Patent Document 1] Japanese Patent Laid-Open No. 2007-133236

An object of the present invention is to provide an optical multilayer body having fewer manufacturing steps and exhibiting a stronger function regardless of the type of functional components contained in the resin layer, and a method for manufacturing the same.

The present inventors conducted diligent research in order to solve the above-mentioned problems. As a result, they obtained the following insight: In order to achieve the above-mentioned object, an acrylic film was used as a transparent substrate instead of a cellulose ester film, and a resin layer containing a functional component was provided on the acrylic film. Furthermore, the coating liquid in which the acrylic film is dissolved is used as the coating liquid constituting the resin layer, and based on the degree of the dissolution, the functional components are easily biased. As a result, it was found that it is possible to provide an optical multilayer body that has fewer manufacturing steps and that exhibits functions more strongly regardless of the type of functional component contained in the resin layer.

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

[1] A method for manufacturing an optical laminated body, which sequentially performs the following steps: a coating step (A), which coats an acrylic base material (acrylic based material) with a radiation-hardening resin containing at least a functional component The composition A forms an unhardened resin layer; the step of reducing the thickness (B) is to dissolve the acrylic substrate by the unhardened resin layer and reduce the thickness of the acrylic substrate by 1.0 to 15.0%; and the hardening step (C ), Which irradiates free radiation to harden the uncured resin layer to form a resin layer; thereby, the functional component is biased toward the surface side of the resin layer.

[2] The method for producing an optical laminated body according to the above [1], wherein the free radiation-curable resin composition A contains polyalkylene glycol di (meth) acrylate ).

[3] An optical laminate, which is obtained by sequentially performing the following steps to bias a functional component toward the surface side of the resin layer, the above step is: a coating step (A), which is on an acrylic substrate The free radiation-curable resin composition A containing a functional component is applied to form an uncured resin layer; the step of reducing the thickness (B) is to dissolve the acrylic substrate with the uncured resin layer and to dissolve the acrylic substrate. The thickness is reduced by 1.0 to 15.0%; and in the curing step (C), the uncured resin layer is cured to form a resin layer.

According to the present invention, it is possible to provide an optical multilayer body having fewer manufacturing steps and exhibiting a stronger function regardless of the type of functional component contained in the resin layer, and a method for manufacturing the same.

Specifically, by adopting the manufacturing method of the present invention, there is no need to perform special treatment on the functional particles, so the range of material selection is wide, the limitation of manufacturing conditions is eased, and no special processing steps are required. In addition, the number of manufacturing steps is small, and the function is more strongly expressed regardless of the type of the functional component contained in the resin layer, and a wide range of functions can be provided at low cost.

Furthermore, by using the method of the present case, in addition to the purpose of the present case, the following effects are brought.

(1) By using an acrylic substrate with good moisture and heat resistance instead of cellulose ester film, it can improve the polarizing function or color-equivalent polarizing plate in a high-temperature and high-humidity environment exhibited in a polarizing plate using a cellulose ester film. The decline in function is due to the disadvantages of warping caused by moisture absorption or water absorption. In addition, an acrylic substrate is cheaper than a cellulose ester film and is easily available in the market, so it has the advantage of further suppressing manufacturing costs.

(2) The optical laminated body in which a resin layer such as a hard coat layer is formed on one or both sides of the acrylic substrate has a disadvantage that the adhesion between the substrate and the resin layer is poorer than when a cellulose film substrate is used. However, in the optical multilayer body of the present invention, by using a coating liquid containing a binder for dissolving an acrylic substrate as the coating liquid constituting the resin layer, the components of the acrylic substrate are eluted to the resin layer, and the two are firmly near the interface between the two. Ground bonding can improve the adhesion between the acrylic substrate and the resin layer. In addition, when the components of the acrylic base material are eluted to the resin layer, the functional components of the resin layer are biased toward the surface of the resin layer, and surface properties based on the functional components can be imparted.

(3) Generally, an optical laminated body in which a resin layer such as a hard coat layer is formed on one or both sides of an acrylic substrate has disadvantages such as a refractive index difference between the acrylic substrate and the resin layer, and the optical laminate is used. When the body is formed with a polarizing plate, etc., interference fringes occur and the appearance is not changed. good. However, as described above, in the optical laminate of the present invention, the components of the acrylic substrate are dissolved in the resin layer, so the change in the refractive index at the interface between the acrylic substrate and the resin layer is reduced, no interference fringes are generated, and the appearance can be improved. bad.

FIG. 1 is a photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical multilayer body obtained by the method for manufacturing an optical multilayer body of Example 1. FIG.

FIG. 2 is a photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical multilayer body obtained by the method for manufacturing an optical multilayer body of Comparative Example 2. FIG.

FIG. 3 is a partially enlarged photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical multilayer body obtained by the method for manufacturing an optical multilayer body of Example 18. FIG.

FIG. 4 is a partially enlarged photograph of a scanning transmission electron microscope (STEM) showing a cross section of a resin layer of an optical laminate obtained by the method for manufacturing an optical laminate in Example 18 from the surface of the resin layer to the side Acrylic substrate side alignment.

FIG. 5 is a partially enlarged photograph of a scanning transmission electron microscope (STEM) showing a cross-section of a resin layer of an optical laminate obtained by the method of manufacturing an optical laminate of Comparative Example 9 from the surface side of the resin layer Acrylic substrate side alignment.

The manufacturing method of the present invention is characterized by sequentially carrying out the following steps: a coating step (A), which coats an acrylic substrate with a free radiation-curable resin composition A containing at least a functional component to form an unhardened resin layer ; Thickening step (B), which is performed by the uncured resin Layer to dissolve the acrylic substrate and reduce the thickness of the acrylic substrate by 1.0 to 15.0%; and a curing step (C), which irradiates free radiation to harden the unhardened resin layer to form a resin layer; thereby making the functional component It leans toward this resin layer surface side.

In the present invention, at least the above steps (A) to (C) are performed in order. However, other steps may be included between the steps within the scope of exerting the effects of the present invention.

Hereinafter, each step will be described in detail.

Steps (A) and (B)

The step (A) in the manufacturing method of the present invention is a coating step in which an uncured resin layer is formed by coating a free radiation-curable resin composition A containing a functional component on an acrylic substrate, and the step (B) is performed by This unhardened resin layer dissolves the acrylic substrate and reduces the thickness of the acrylic substrate by a thickness reduction step of 1.0 to 15.0%.

FIG. 1 is a photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical multilayer body obtained by the method for manufacturing an optical multilayer body of Example 1. FIG. In addition, FIG. 2 is a photograph of a scanning transmission electron microscope (STEM) showing a cross section of an optical multilayer body obtained by the method for manufacturing an optical multilayer body of Comparative Example 2. It can be seen that although the acrylic substrate having a thickness of 40 μm was used in both Example 1 and Comparative Example 2, the thickness of the acrylic substrate in FIG. 1 (Example 1) was reduced by 3 μm (7.5%). In contrast, FIG. 2 (Comparative Example 2) ) The thickness of the acrylic substrate is hardly reduced.

<Acrylic substrate>

The acrylic resin contained in the acrylic substrate is not particularly limited. For example, it is preferably one obtained by polymerizing one (meth) acrylic acid alkyl ester or a combination of two or more. More specifically, it is preferable to use (a Base) methyl acrylate recipient.

In addition, those having a ring structure such as an acrylic resin having a lactone ring structure and an acrylic resin having a fluorene imine ring structure can also be used. These resins are described in detail below.

The optical laminated body of the present invention has an acrylic resin in the base material, which is superior to those having a base material made of TAC in that it has excellent heat and humidity resistance and can prevent the occurrence of wrinkles. In addition, in this specification, "acrylic resin" means an acrylic resin and / or a methacrylic resin.

What is important in the present invention is that in the thickness reduction step (B) detailed below, the acrylic substrate is dissolved by the uncured resin layer to reduce the thickness of the acrylic substrate by 1.0 to 15.0%. That is, the acrylic base material in the present invention is eroded to form the acrylic base material by using a free radiation-curable resin composition A containing a functional component, in particular, a solvent contained in the resin composition A, and the acrylic The resin is eluted to the unhardened resin layer, thereby reducing the thickness of the acrylic substrate.

In the thickness reduction step (B), if the reduction rate of the thickness of the acrylic substrate is less than 1.0%, the components in the acrylic substrate will not be sufficiently transferred to the resin layer, and the functional components in the resin layer cannot be oriented. The surface is biased, and the adhesion between the acrylic substrate and the resin layer cannot be improved, and further, interference fringes cannot be prevented. In addition, in the thickness reduction step (B), if the reduction rate of the thickness of the acrylic substrate exceeds 15.0%, the strength of the acrylic substrate is insufficient, and it may be applied to the substrate during the thickness reduction step (B) or subsequent use processes. Rupture.

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

In the thickness reduction step (B), whether the thickness of the acrylic substrate is reduced can be measured literally as described before and after the thickness reduction step (B), but for example, even after the thickness reduction step (B), The thickness and thickness of the acrylic substrate on the portion where the free radiation-curable resin composition A is not applied are The thicknesses of the acrylic substrates at the locations where the free radiation-curable resin composition A was applied were compared and confirmed. In addition, when the thickness of the acrylic substrate before the thickness reduction step (B) is not obvious, it is preferable that the thickness of the acrylic substrate of the coated portion and the uncoated portion be relatively close. Compare.

In addition, in the present invention, the thickness of the acrylic substrate after the thickness reduction step (B) is an average value of a width of 30 μm of a scanning transmission electron microscope (STEM) photograph showing a cross section of the optical laminate. For example, when the surface of the acrylic substrate is rough as shown in FIG. 3, the average distance from the surface of the acrylic substrate opposite to the resin layer to the resin layer is calculated in a 30 μm width area of the STEM photograph. The average distance is set as the thickness of the acrylic substrate after the thickness reduction step (B). In addition, the thickness of the resin layer after the curing step (C) (the thickness of the layer of the resin layer and the composition of the acrylic substrate are completely integrated to complete the curing) is calculated in a 30 μm width area of the STEM photograph from the resin The average distance from the surface of the layer to the acrylic substrate was set as the thickness of the resin layer.

The thickness of the acrylic substrate is preferably 20 to 300 μm, more preferably 30 to 200 μm, and even more preferably 30 to 100 μm. When the acrylic base material is 20 μm or more, the base material is not easily cracked even after the thickness reduction step (B), and it is not easy to curl after the hardening step (C). In addition, when the acrylic substrate is 300 μm or less, the optical laminate of the present invention becomes thin, and optical properties such as light permeability are excellent.

In the thickness reduction step (B), it is preferred that the thickness of the acrylic substrate after the resin layer is formed be reduced by 0.5 to 5.0 μm, and more preferably reduced by 1.5 to 5.0 μm compared to the thickness of the acrylic substrate before the resin layer is formed. . If it falls within this range, the effects of the present invention described above can be more fully exhibited.

Furthermore, the acrylic substrate in the present invention is preferably an extended acrylic substrate. By using an extended acrylic substrate, the strength or dimensional stability of the substrate can be improved.

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

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

In the general 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. 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 described above is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and more It is preferably 10 to 60% by mass, and most preferably 10 to 50% by mass. When the content rate of the lactone ring structure represented by the said General formula (1) is 5 mass% or more, heat resistance, solvent resistance, and surface hardness will improve, and 90 mass% or less will improve moldability.

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

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

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

In addition, such a glutarimidine imine structure can be formed, for example, by amidine imidation of a (meth) acrylic acid ester polymer with a fluorinated imidating agent such as methylamine. Here, the "(meth) acrylic acid" means "acrylic acid" and "methacrylic acid".

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

In the general formula (3), R ⁷ and R ⁸ independently represent a hydrogen atom or a methyl group, and R ⁹ represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, cyclopentyl group, cyclohexyl group, or benzene. base.

Furthermore, an acrylic resin having such an N-substituted maleimide diimide structure in the main chain can be formed by copolymerizing an N-substituted maleimide diimide and a (meth) acrylate, for example.

The glass transition point (Tg) of the acrylic resin is preferably 100 to 150 ° C, more preferably 105 to 135 ° C, and even more preferably 110 to 130 ° C. When the glass transition point (Tg) of the acrylic resin is 100 ° C or higher, the resin layer is less likely to be damaged by the solvent contained in the composition for forming the resin layer. On the other hand, when the temperature is 150 ° C or lower, it is easy to be damaged. Unevenness is formed at the interface with the resin layer to be described later.

The acrylic substrate may contain a resin other than the acrylic resin, and the ratio of the acrylic resin in the acrylic substrate is preferably 80% by mass or more, and more preferably 90% by mass or more.

The above-mentioned acrylic base material can be produced, for example, by performing normal melt extrusion on a chip made of acrylic resin whose humidity is controlled, then cooling it while extending it in the longitudinal direction (film-forming direction), Thereafter it extends laterally.

In the above-mentioned melt extrusion step, a uniaxial, biaxial, or more than two-screw screw can be used, and the rotation direction, number of revolutions, and melting temperature of the screw can be arbitrarily set.

It is preferable to perform the said extending | stretching so that it may become a desired thickness after extending | stretching. The stretching 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 extension can be arbitrarily determined. The extension method may be a common method.

In addition, in order to prevent the adhesion when winding the acrylic substrate, an undercoat layer may be formed on at least one side of the acrylic substrate before or after the acrylic substrate is extended, or a roller pattern may be provided on both sides of the acrylic substrate. .

The acrylic substrate may contain acrylic rubber particles, an antioxidant, an ultraviolet absorber, a plasticizer, and the like. The acrylic rubber particles can easily prevent cracking of the acrylic resin substrate.

In the present invention, the acrylic substrate may be subjected to saponification treatment, glow discharge treatment, corona discharge treatment, plasma treatment, ultraviolet (UV) treatment, and flame treatment within a range not departing from the gist of the present invention. And other surface treatment.

<Free Radiation Curing Resin Composition A Containing Functional Components>

(Functional ingredients)

Examples of the functional component include an antistatic agent, a refractive index adjuster, an antifouling agent, a slip agent, an antireflection agent, an antiglare agent, a hard-coating imparting agent, and an anti-blocking agent. Sheeter.

The antistatic agent may be an organic one or an inorganic one. As the organic one, specific examples include ionic ones such as lithium ion salts, quaternary ammonium salts, and ionic liquids, or polythiophenes and polyanilines. , Polypyrrole, polyacetylene and other electronic conductivity. Examples of the inorganic system include metal oxides such as ATO, ITO, PTO, GZO, antimony pentoxide, and zinc oxide, silver nanowires, carbon nanotubes, and fullerenes.

Regarding the refractive index modifier, examples of the low refractive index material include inorganic materials such as hollow silica, solid silica, magnesium fluoride, and sodium fluoride; and fluorine such as fluorine-containing monomers, oligomers, and polymers. Department of materials and so on. On the other hand, examples of the high refractive index materials include inorganic materials such as zirconia, titanium oxide, ATO, ITO, PTO, GZO, and antimony pentoxide, and halogens (bromine and iodine atoms) other than chlorine and fluorine. Organic materials, organic materials containing sulfur atoms, organic materials having at least one benzene ring skeleton or naphthalene skeleton, anthracene skeleton in the molecule, carbazole materials, and the like.

Examples of the antifouling agent include fluorine-based resins, polysiloxane-based resins, fluorine-polysiloxane copolymer resins, and surfactants not containing fluorine and polysiloxane. Examples of the lubricant include a fluorine-based resin, a silicone resin, and a fluorine-polysiloxane copolymer resin.

Examples of the antireflection agent include the aforementioned low refractive index materials.

Examples of the anti-glare agent include silica particles, acrylic resin particles, melamine particles, benzoguanamine particles, and polysiloxane particles. Examples of the hard-coating property imparting agent include solid ultrafine particles such as silica, alumina, and the like, shaped particles, chain-shaped particles, and fine particles with fine protrusions (gold sugar-type particles).

Examples of the anti-blocking agent include fine particles of silicon dioxide, acrylic acid, styrene, and alumina.

Regarding the content of the functional component, the antistatic agent is preferably in a range of 0.1 to 30% by mass based on the total mass of the total solid component in the free radiation-curable resin composition A. The content of the refractive index adjuster is preferably in a range of 5 to 30% by mass based on the total mass of the total solid components in the free radiation-curable resin composition A. The content of the antifouling agent is preferably in a range of 0.01 to 5% by mass with respect to the total mass of the total solid components in the free radiation-curable resin composition A. The content of the lubricant is preferably in a range of 0.01 to 5% by mass based on the total mass of the total solid components in the free radiation-curable resin composition A. The anti-glare agent is preferably in a range of 1 to 20% by mass based on the total mass of the total solid components in the free radiation-curable resin composition A. The hard-coating property imparting agent is preferably in a range of 5 to 40% by mass based on the total mass of the total solid components in the free radiation-curable resin composition A. The anti-blocking agent is preferably in a range of 0.1 to 5% by mass based on the total mass of the total solid components in the free radiation-curable resin composition A.

Furthermore, as described below, in the present invention, since the functional component is biased toward the upper surface of the resin layer, the effect of the above-mentioned functional component can be expressed in a smaller content.

As shown in FIG. 3 and FIG. 4, since the functional components of the optical laminate of the present invention are biased toward the upper surface of the resin layer, the functions of the functional components can be more strongly expressed. For example, in the case where the resin layer of the optical laminate of the present invention contains an antistatic agent as a functional component, the antistatic agent is biased toward the surface side of the resin layer, which is in contrast to the case where the same amount of the antistatic agent is uniformly dispersed. Than, stronger antistatic performance.

Similarly, when the resin layer contains an anti-glare agent, reflection is further prevented. When a low refractive index agent is included, the reflectance is further reduced. When a hard coating property imparting agent is included, the hard coating performance is further improved. .

Further, as shown in FIG. 5, when the resin layer is formed without dissolving the acrylic substrate, the functional component cannot be biased toward the upper surface of the resin layer.

In the present invention, the mechanism by which the functional component is biased toward the upper surface of the resin layer is estimated as follows. That is, it is presumed that the material component of the dissolved acrylic substrate flows out into the resin layer with the action of the solvent volatilization described below, and gives a force to push the functional component toward the upper layer.

Therefore, in the case where the specific gravity of the functional component relative to the resin component of the matrix is relatively light, the functional component is moved to the upper direction due to the difference in specific gravity. However, in the case of the present invention, it is considered that If the component is heavy, the functional component may be biased toward the surface of the resin layer.

In particular, 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 tends to be biased toward the upper side of the resin layer. In addition, when the compatibility between the functional component and the resin of the resin layer is better than that of the acrylic resin in the acrylic substrate, the functional component tends to be biased toward the upper side of the resin layer.

In addition, as described above, the material components of the acrylic substrate flow out into the resin layer, so that there are moderate irregularities at the interface between the acrylic substrate and the resin layer, and the adhesion between the acrylic substrate and the resin layer becomes better. Optical distances are different, so interference fringes are not clear, and anti-interference fringes are also good.

In addition, the functional component often has a refractive index different from that of acrylic as the base material. Therefore, if the functional component is uniformly dispersed in the resin layer, a refractive index difference occurs between the acrylic base material and the resin layer, and interference fringes tend to occur. On the other hand, since the optical laminated body of the present invention hardly exists at the acrylic substrate-resin layer interface, it is difficult to generate interference fringes due to the difference in refractive index.

(Free radiation curable resin)

As used herein, the term "radiation-curable resin composition" means an electron beam-curable resin composition or an ultraviolet-curable resin composition. The free radiation curable resin is preferably a polyalkylene glycol di (meth) acrylate as a main component. Specifically, the content of the polyalkylene glycol di (meth) acrylate in the free radiation curable resin is preferably 25 to 100% by mass, and more preferably 50 to 100% by mass in terms of solid content.

The acrylic substrate is also dissolved by the solvent, but the acrylic substrate can be more easily dissolved by the multiplication of the solvent and the polyalkylene glycol di (meth) acrylate. In addition, polyalkylene glycol di (meth) acrylate is easily mixed with the resin component of the acrylic substrate. Therefore, by using a polyalkylene glycol di (meth) acrylate as the radiation-hardenable resin, it is possible to easily bias the functional component above the resin layer.

Examples of the polyalkylene glycol di (meth) acrylate include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) Polyacrylate Polypropylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, and dibutyl glycol di (meth) acrylate, tributyl glycol di (meth) acrylate Polybutylene glycol di (meth) acrylates such as meth) acrylates and tetrabutanediol di (meth) acrylates.

The polyalkylene glycol di (meth) acrylate is preferably one having a molecular weight of 180 to 1,000, more preferably one having a molecular weight of 200 to 750, and particularly preferably one having a molecular weight of 220 to 450. When the molecular weight is within this range, the acrylic substrate and the resin layer are excellent in adhesion or interference fringing resistance, and the functional component can be easily biased above the resin layer.

The free radiation-curable resin composition A preferably contains polyalkylene glycol di (meth) acrylate as a main component, but may also contain other components described below. Furthermore, when materials with extremely different properties are mixed in the free radiation-curable resin composition A, an island structure is formed when components of the acrylic base material flow into the resin layer side in the thickness reduction step (B). And the appearance is damaged. Therefore, in a case where the material of the free radiation-curable resin composition A is two or more components, it is preferable to use a material having similar properties.

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

Specific examples of the monofunctional (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, and (meth) ) Cyclohexyl acrylate, 2-ethylhexyl (meth) acrylate, phenyl (meth) acrylate, propylene morpholine, N-acryloxyethyl hexahydrophthalimide, Tetrahydrofurfuryl acrylate, isoamyl acrylate, phenoxyethyl acrylate, adamantyl acrylate, alkylene glycol mono (meth) acrylate (ethylene glycol mono (meth) acrylate, propylene glycol mono ( (Meth) acrylate, butanediol mono (meth) acrylate, etc.) or polyalkylene glycol mono (meth) acrylate (polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) Acrylate), polybutylene glycol mono (meth) acrylate, etc.), particularly preferred is alkylene glycol mono (meth) acrylate.

Specific examples of the trifunctional (meth) acrylate include isocyanurate triacrylate, polyalkylene glycol tri (meth) acrylate (trimethylolpropane tri (meth) acrylate). , Neopentaerythritol tri (meth) acrylate, etc.).

Further, as the monofunctional (meth) acrylate and trifunctional (meth) acrylate, modified products of propylene oxide (PO) and ethylene oxide (EO) of each compound may be used.

By using a monofunctional (meth) acrylate, it becomes easy to adjust viscosity, and adhesiveness with a base material becomes favorable. In addition, the monofunctional (meth) acrylate can be easily mixed with the resin component in the acrylic substrate, so that the functional component can be easily biased above the resin layer.

When a trifunctional (meth) acrylate is used, hardness can be improved. On the other hand, a trifunctional (meth) acrylate tends to be difficult to mix with a resin component in an acrylic substrate, and there is a case where it becomes difficult to bias a functional component upward from the resin layer.

In addition, in this specification, "(meth) acrylate" means a methacrylate and an acrylate.

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

(Photopolymerizable polymer)

As the photopolymerizable polymer, those having a (meth) acrylfluorenyl group as a functional group are preferred, and the number of functional groups is preferably 10 to 250, more preferably 10 to 100, and even more preferably 10 to 50 people.

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

The blending amount of the photopolymerizable polymer in the free 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)

As the photopolymerizable oligomer, one having more than two functions can be used, preferably one having a (meth) acrylfluorenyl group as a functional group, preferably one having 2 to 30 functional groups, and more preferably 2 to 20 It is further preferably 3 to 15.

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

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

(Other photopolymerizable monomers)

Examples of other photopolymerizable monomers include compounds other than the above-mentioned (meth) acrylates and tetrafunctional or more (meth) acrylates having one or two or more unsaturated bonds. Examples of compounds other than (meth) acrylates include monofunctional monomers such as styrene, methylstyrene, and N-vinylpyrrolidone, and polyfunctional monomers such as poly (meth) acrylates of polyhydric alcohols.体 等。 Body and so on. Examples of the tetrafunctional or higher (meth) acrylates include neopentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol penta (meth) acrylic acid. Esters, etc., and polyfunctional compounds modified by using ethylene oxide (EO) or the like.

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

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

The blending amount of other photopolymerizable monomers in the free radiation-curable resin composition A is not particularly limited as long as it exhibits the effects of the present invention, and it is preferably 0 to 40% by mass in terms of solid content conversion, and more preferably 0 to 30% by mass.

(Starter)

The initiator is not particularly limited, and a known one may be used. For example, as a photopolymerization initiator, specific examples include acetophenones, benzophenones, and Michele benzamidine benzoic acid. Ester, α-pentyloxime ester, 9-oxosulfur Type, phenylacetone type, benzophenone type, benzoin type, fluorenyl phosphine oxide type. In addition, it is preferable to use a mixed photosensitizer, and 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 radical polymerizable unsaturated group, it is preferable to use acetophenones alone or in combination. Benzophenones, 9-oxysulfur Type, benzoin, benzoin methyl ether, etc., 1-hydroxy-cyclohexyl-phenyl-ketone is particularly preferred due to its compatibility with free radiation-curable resins and less yellowing. When the photopolymerizable monomer / oligomer / polymer has a cationically polymerizable functional group, the photopolymerization initiator is preferably an aromatic diazonium salt, an aromatic sulfonium salt, Aromatic sulfonium salts, metallocene compounds, benzoin sulfonate and the like are used alone or as a mixture.

The content of the initiator in the above-mentioned free radiation-curable resin composition A is 1 to 10% by mass based on the total mass of the total solid component. If 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 if it is 10% by mass or less, the resin caused by excessive residue of the initiator can be suppressed Deterioration and prevention of cost increase, pencil hardness of the target resin layer or the hard coat surface described below can be obtained.

The lower limit of the content of the above-mentioned starter relative to the total mass of the total solids component is 2 Mass%, and a more preferable upper limit is 8 mass%. When the content of the initiator is within this range, the hardening can be made more certain.

(Solvent-drying resin)

The above-mentioned free radiation-curable resin composition A may further contain a solvent-drying resin. By using a solvent-drying resin in combination, it is possible to effectively prevent coating defects on the coating surface. The above-mentioned solvent-drying resin refers to a resin such as a thermoplastic resin that is added to adjust a solid component during coating, and is a film that is formed by merely 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 a styrene resin, a (meth) acrylic resin, a vinyl acetate resin, a vinyl ether resin, a halogen-containing resin, an alicyclic olefin resin, and a polymer. Carbonate resin, polyester resin, polyamide resin, cellulose derivative, silicone resin, rubber or elastomer, etc. The thermoplastic resin is preferably amorphous and soluble in an organic solvent (especially a common solvent capable of dissolving a plurality of polymers or hardening compounds). Especially from a viewpoint of film forming property, transparency, or weather resistance, a styrene resin, a (meth) acrylic resin, an alicyclic olefin resin, a polyester resin, and a cellulose derivative are preferable. (Cellulose esters, etc.) and the like.

(Solvent)

The free radiation-curable resin composition A preferably further contains a solvent.

The solvent is preferably selected from those which will moderately dissolve the acrylic substrate. In more detail, it is preferable to select the above-mentioned method. In the thickness reduction step (B), the thickness of the acrylic substrate after the resin layer is formed is reduced by 1.0 to 15.0% relative to the thickness of the acrylic substrate before the resin layer is formed. Solvent.

However, acrylic substrates are different from previously used TAC substrates and can be used by almost all species. Similar solvents dissolve. Therefore, the influence caused by the solvent is strong, and if the solubility is too strong, there may be cases where it is broken and the optical laminate cannot be produced. Therefore, among the solvents, the following solvents are preferably selected. The solubility of the acrylic substrate is also affected by the mass ratio of the solvent in the coating liquid or the drying temperature of the solvent. Therefore, it is preferable to select an appropriate one from the following solvents in consideration of the amount of the solvent used and the drying temperature.

Examples of such a solvent include alcohols, ketones, aromatic hydrocarbons, glycols, and the like, and in the case of alcohols, lower alcohols such as methanol, ethanol, isopropanol, and 1-butanol are preferred. In addition, each solvent other than alcohols tends to be more favorable if the number of carbons is higher, and the solvent having a higher evaporation rate tends to be better. Specifically, methyl isobutyl ketone may be exemplified if it is a ketone, toluene may be exemplified if it is an aromatic hydrocarbon, propylene glycol monomethyl ether, etc. may be exemplified if it is a diol, and a mixture of these may also be exemplified. Solvent.

Especially in the present invention, the resin has excellent compatibility and coating properties, and also forms a special uneven shape in the present case at the interface between the acrylic substrate and the resin layer, so that the failure of the substrate does not occur during processing. For reasons, it is particularly preferable to contain one or more selected from the group consisting of methyl isobutyl ketone, isopropyl alcohol, 1-butanol, and propylene glycol monomethyl ether. If it is these solvents, it can melt | dissolve moderately without breaking an acrylic base material.

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; Ethers such as alkane, tetrahydrofuran, propylene glycol monomethyl ether acetate; aliphatic hydrocarbons such as hexane; aromatic hydrocarbons other than toluene such as xylene; halogenated carbons such as dichloromethane, dichloroethane; methyl Fibrinolysins such as lysinolysin, ethyl lysinolysin; fibrinolysins such as acetic acid; hydrazones such as dimethylarsine; amides such as dimethylformamide and dimethylacetamide Since the acrylic substrate is excessively dissolved, it is preferably not used when tension is applied to the substrate.

The content ratio of the solvent in the above-mentioned free radiation-curable resin composition A is determined within a range in which the acrylic substrate is moderately dissolved according to the type of the solvent used and the drying temperature of the solvent. The content of the above-mentioned preferable solvent is preferably 30 to 300 parts by mass, and more preferably 100 to 220 parts by mass with respect to 100 parts by mass of the solid content of the free radiation-curable resin composition A.

The acrylic substrate-resin layer interface in the optical laminate of the present invention is, for example, an acrylic substrate that is appropriately dissolved by a solvent, and a polyalkylene glycol di (meth) acrylate having a moderate molecular weight is accompanied by this. Isotonic penetration into acrylic substrate. In addition, when the components of the resin layer penetrate into the acrylic substrate, the material components of the acrylic substrate are conversely extruded in the direction of the resin layer, or the solvent is volatilized from the acrylic substrate to the air surface of the resin layer. The material component of the acrylic substrate also penetrates into the resin layer. As described above, it is considered that each component moves from the upper part to the lower part and from the lower part to the upper part, thereby generating appropriate unevenness at the interface, and the adhesiveness is improved, and the anti-interference fringing property is also improved.

(Preparation of Free Radiation Curable Resin Composition A)

The method for producing the free radiation-curable resin composition A is not particularly limited as long as the components can be uniformly mixed, and for example, a known device such as a paint shaker, a bead mill, a kneader, and a stirrer can be used.

(Coating method)

The method for applying the free radiation-curable resin composition A in the coating step (A) to the acrylic substrate is not particularly limited, and examples thereof include a spin coating method, a dipping method, a spray method, and a mold. The nozzle coating method, the bar coating method, the gravure coating method, the roll coater method, the liquid surface bending coating method, the flexographic printing method, the screen printing method, and the droplet coater method are known. method.

(Drying step)

Second, if necessary, a drying step is performed. There are cases where the thickness of the acrylic substrate is also reduced by the drying step, and in this case, the drying step becomes part of the (B) thickness reduction step.

The drying time in the drying step is preferably 20 seconds to 120 seconds, and more preferably 40 seconds to 80 seconds. The drying temperature in the drying step is preferably 40 to 90 ° C, and more preferably 50 to 80 ° C. If the drying temperature exceeds 100 ° C, even if a solvent with better solubility in acrylic acid is selected, the solvent's penetrability and the like will increase, which will cause the substrate to break. Therefore, the drying temperature is preferably in the case of whichever solvent is used The temperature is basically below 90 ° C. For example, as described above, methyl isobutyl ketone is a preferred solvent. However, even if the solvent is a drying temperature of 100 ° C, the acrylic substrate may be broken by applying tension.

The minimum temperature may be such that the solvent can be dried, and is preferably 40 ° C or higher. For example, in the case of methyl isobutyl ketone and a drying temperature of 30 ° C, curing may be performed directly by ultraviolet rays or the like in a state of insufficient drying. In this case, curing may not be performed smoothly, and unsettling may occur. Hardened part. At this time, the adhesion may be reduced.

(C) Step

Step (C) in the manufacturing method of the present invention is a hardening step of irradiating free radiation to harden an unhardened resin layer to form a resin layer.

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

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

As a specific example of the electron beam source irradiated by the above electron beam, Kirklauf-Walten Electron beam accelerators of various types, such as Vandergraff type, resonant transformer type, insulated core transformer type, or linear type, high frequency and high voltage accelerator type, and high frequency type.

In addition, the preferred film thickness of the above resin layer (thickness of the layer in which the components of the resin layer and the component of the acrylic substrate are completely integrated and hardened) is 0.5 to 100 μm, and more preferably 0.8 to 20 μm. Particularly, the crack resistance is particularly preferably in a range of 2 to 10 μm.

<Optical laminate>

The optical laminated body of the present invention is characterized in that the following steps are sequentially performed: a coating step (A), which forms an uncured resin layer by coating a free radiation-curable resin composition A containing a functional component on an acrylic substrate. ; A thickness reduction step (B), which is to dissolve the acrylic substrate by the uncured resin layer, and reduce the thickness of the acrylic substrate by 1.0 to 15.0%; and a curing step (C), which is the uncured resin The layer is hardened to form a resin layer; thereby, the functional component is biased toward the surface side of the resin layer.

Since the various components mentioned above can be used as a functional component, the optical laminated body of this invention can be comprised only with an acrylic base material and a resin layer.

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

<Hard coating>

The hard coat layer is preferably composed of a cured product of the free radiation-curable resin composition B.

In the pencil hardness test (load: 4.9N) according to JIS K5600-5-4 (1999), the hardness of the hard coating layer is preferably H or more, and more preferably 2H or more. Moreover, the said hard-coat layer may be a thing containing the said functional component other than a hard-coating property imparting agent.

Details of the free radiation-curable resin composition B forming the hard coat layer are It is the same as the above-mentioned free radiation-curable resin composition A.

In addition, the blending amount of the photopolymerizable monomer (especially a polyfunctional monomer) of the free radiation-curable resin composition B is preferably 30 to 100% by mass and more preferably 40 to 100% of the total mass of the total solid component. 90% by mass, more preferably 50 to 80% by mass.

Furthermore, the total amount of the photopolymerizable oligomer and photopolymerizable polymer in the free radiation-curable resin composition B is preferably 30 to 100% by mass, and more preferably 40 to the total mass of the total solid content. ~ 90 mass%, more preferably 50 to 80 mass%.

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

In the present invention, a hard coat layer is preferably laminated on the resin layer. In order to obtain the hardness as an optical laminate, it is considered to make the resin layer itself high in hardness. However, when a material having a polyfunctional reactive functional group and a high hardness of 2H or more is used directly on the acrylic substrate, that is, when the resin layer is made to have a high hardness of 2H or more, there is a possibility of locally applying a certain pressure to the hard coating layer. In some cases, the acrylic substrate is liable to crack. Therefore, in the optical multilayer body of the present invention, it is preferable that the impact of the hard coating layer is not directly transmitted to the acrylic substrate and has a buffering effect by having the resin layer between the hard coating layer and the hard coating layer. In addition, by forming a resin layer / hard coat layer, the hardness can be increased as compared with a case where only a hard coat layer is laminated.

However, when a hard coat layer is laminated, etc., a new interface with the resin layer is formed, and the portion that causes an interference fringe is increased. In this case, it is important that the refractive index of the laminated layer be as close as possible to the underlying layer. Therefore, in order to maintain the anti-interference fringe property well, the refractive index of the hard coat layer is preferably substantially the same as the refractive index of the resin layer, and the preferable refractive index difference is 0.03 or less.

<Low refractive index layer>

The optical laminated body of the present invention preferably has a low refractive index layer on the hard coat layer.

As the low-refractive index layer, it is preferable to use 1) a resin containing low-refractive index inorganic particles such as silicon dioxide or magnesium fluoride, 2) a fluorine-based resin containing a low-refractive index resin, and 3) containing silicon dioxide or A fluorine-based resin of low-refractive index inorganic fine particles such as magnesium fluoride, and 4) a composition for forming a low-refractive index layer containing any of low-refractive index inorganic films such as silicon dioxide and magnesium fluoride. Regarding the resin other than the fluorine-based resin, the same resin as the above-mentioned acrylic resin can be used.

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

The refractive index of these low refractive index layers is 1.47 or less, and particularly preferably 1.42 or less. The thickness of the low-refractive index layer is not limited, and generally it may be appropriately set within a range of about 10 nm to 1 μm.

As the fluorine-based resin, a polymerizable compound containing a fluorine atom in a molecule or a polymer thereof can be used. Although it does not specifically limit as a polymerizable compound, For example, it is preferable to have a hardening reactive group, such as a functional group hardened by a free radiation, and a thermally hardening polar group. It may also be a compound having both of these reactive groups. With respect to this polymerizable compound, the so-called polymer system does not have any of the reactive groups and the like described above.

As the polymerizable compound having a functional group hardened by free radiation, a fluorine-containing monomer having an ethylenically unsaturated bond can be widely used. More specifically, fluoroolefins (e.g., fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluorobutadiene, perfluoro-2,2-dimethyl-1,3- Dioxolene, etc.).

Further, a fluorine-containing monomer having a (meth) acrylic fluorenyloxy group may be used. Specific examples include 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, and 2- (meth) acrylic acid. Perfluorobutyl) ethyl ester, 2- (perfluorohexyl) ethyl (meth) acrylate, 2- (perfluorooctyl) ethyl (meth) acrylate, 2- (perfluorodecyl) (meth) acrylate (Meth) acrylate, (alpha) -trifluoromethyl methacrylate, (alpha) -trifluoromethacrylate and the like (meth) acrylate compounds having a fluorine atom in the molecule.

Furthermore, there are compounds containing a fluoroalkyl group, a fluorocycloalkyl group or a fluoroalkylene group having 1 to 14 carbon atoms having at least 3 fluorine atoms in the molecule, and at least 2 (meth) acryloxy groups. Fluorine polyfunctional (meth) acrylate compounds and the like.

Next, as the above-mentioned thermally-curable polar group, a hydrogen bond-forming group such as a hydroxyl group, a carboxyl group, an amine group, or an epoxy group is preferred. These are not only excellent in adhesion to the coating film, but also excellent in affinity with inorganic ultrafine particles such as silicon dioxide. Examples of the polymerizable compound having a thermosetting polar group include a 4-fluoroethylene-perfluoroalkyl vinyl ether copolymer; a fluoroethylene-hydrocarbon-based vinyl ether copolymer; an epoxy resin, a polyurethane, and cellulose , Phenol, polyimide and other resins such as fluorine modified products.

Examples of the polymerizable compound having both a functional group hardened by the above-mentioned free radiation and a polar group thermally hardened include partially or fully fluorinated alkyl, alkenyl, and aryl esters of acrylic or methacrylic acid, and Partially fluorinated vinyl ethers, completely or partially fluorinated vinyl esters, completely or partially fluorinated ketenes, etc.

Examples of the fluorine-based resin include the following.

A polymer containing at least one monomer or monomer mixture of a fluorine-containing (meth) acrylate compound as the polymerizable compound having a free radiation-curable group; at least one of the fluorine-containing (meth) acrylate compounds 1 type with methyl (meth) acrylate, ethyl (meth) acrylate, (meth) Copolymers of (meth) acrylate compounds containing no fluorine atom in the molecule, such as propyl acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; vinyl fluoride, vinylidene Fluorine-containing monomers such as fluoroethylene, trifluoroethylene, trifluorochloroethylene, 3,3,3-trifluoropropylene, 1,1,2-trichloro-3,3,3-trifluoropropylene, and hexafluoropropylene Homopolymer or copolymer. Polysiloxane-containing vinylidene fluoride copolymers containing a polysiloxane component in these copolymers can also be used. Examples of the polysiloxane component in this case include (poly) dimethylsiloxane, (poly) diethylsiloxane, (poly) diphenylsiloxane, and (poly) methylphenylsiloxane). Oxane, alkyl modified (poly) dimethylsiloxane, (poly) dimethylsiloxane containing azo group, dimethylpolysiloxane, phenylmethylpolysiloxane, alkyl- Aralkyl modified polysiloxane, fluoropolysiloxane, polyether modified polysiloxane, fatty acid ester modified polysiloxane, methylhydrogen polysiloxane, silanol containing silanol, alkoxy Polysiloxane based on phenol, polysiloxane based on phenol group, modified polysiloxane based on methacryl group, modified polysiloxane based on propylene group, polysiloxane based on amino group, polysiloxane based on carboxylic acid, Methanol modified polysiloxane, epoxy modified polysiloxane, mercapto modified polysiloxane, fluorine modified polysiloxane, polyether modified polysiloxane, etc. Among them, those having a dimethylsiloxane structure are preferred.

Furthermore, non-polymers or polymers composed of the following compounds can also be used as the fluorine-based resin. That is, a compound obtained by reacting a fluorine-containing compound having at least one isocyanate group in the molecule with a compound having at least one amine group, a hydroxyl group, and a carboxyl group and a functional group that reacts with an isocyanate group in the molecule; Fluorinated polyether polyols, fluorinated alkyl polyols, fluorinated polyester polyols, fluorinated polyols such as fluorinated ε-caprolactone modified polyols, and compounds obtained by reacting compounds having isocyanate groups, etc. .

The composition for forming a low-refractive-index layer may contain each of the thermoplastic resins described above together with the polymerizable compound or polymer having a fluorine atom. Further, a hardening agent for hardening a reactive group or the like can be appropriately used, and in order to improve coating properties or impart antifouling properties, Various additives and solvents can be used suitably.

In the formation of the above-mentioned low-refractive index layer, it is preferable that the viscosity of the composition for forming the above-mentioned low-refractive index layer is set to 0.5 to 5 mPa to obtain better coatability. The range of s (25 ℃) is preferably 0.7 ~ 3mPa. S (25 ° C). It can realize an excellent anti-reflection layer for visible light, and it can form a uniform and non-uniform thin film, and it can form a low refractive index layer with excellent adhesion.

The hardening means of the resin may be the same as the hardening means of the above-mentioned hard coat layer. When a heating means is used for the hardening treatment, it is preferable to add a thermal polymerization initiator that starts the polymerization of the polymerizable compound by heating, for example, to generate a radical, to the composition for forming a low refractive index layer.

The optical laminated body of the present invention preferably has a total light transmittance of 80% or more. If it is less than 80%, when it is installed in an image display device, there is a possibility that the color reproducibility or visibility may be impaired. In addition, there is a possibility that a desired contrast cannot be obtained. The above-mentioned total light transmittance is more preferably 90% or more.

The above-mentioned total light transmittance can be measured by a method according to JIS K-7361 using a haze meter (manufactured by Murakami Color Technology Research Institute, product number: HM-150).

Moreover, it is preferable that the haze of the optical laminated body of this invention is 1% or less. If it is 1% or less, desired optical characteristics can be obtained, and there is no deterioration in visibility when the optical laminated body of the present invention is provided on the image display surface.

The haze can be measured by a method according to JIS K-7136 using a haze meter (manufactured by Murakami Color Technology Research Institute, product number: HM-150).

The optical laminated body of the present invention can be used as a polarizing plate, and is formed by layering the optical laminated body of the present invention on at least one area of a polarizing film.

The polarizing film is not particularly limited, and for example, a polyvinyl alcohol film, a polyvinyl formal film, a polyvinyl formal film, an ethylene-vinyl acetate copolymer that is dyed and stretched with iodine, or the like can be used. Department of saponification film. In the lamination process of the polarizing film and the optical laminate, it is preferable to perform a saponification treatment on an acrylic substrate. By the saponification treatment, the adhesiveness becomes good and an antistatic effect can also be obtained.

The optical multilayer body of the present invention can be applied to an image display device including the optical multilayer body and / or the polarizing plate.

Examples of the image display device include a television, a computer, an LCD, a PDP, a FED, an ELD (organic EL, an inorganic EL), a CRT, a tablet PC, an electronic paper, a mobile phone, and the like, and can also be preferably used in an image display Touch panel used in the etc.

The LCD as a representative example includes a transmissive display and a light source device for irradiating the transmissive display from the back. When the image display device using the optical laminated body of the present invention is an LCD, the optical laminated body of the present invention is formed on the surface of the transparent display body and / or the polarizing plate using the optical laminated body of the present invention is used. Become. However, in the case of an image display device equipped with a touch panel, in addition to the configuration surface, it can also be used as a transparent substrate or the like inside the device.

In the image display device using the optical laminated body of the present invention, the light source of the light source device is irradiated from the lower side of the optical laminated body or the polarizing plate. Furthermore, a retardation plate may be inserted between the image display element and the polarizing plate. An adhesive layer may be provided between the layers of the image display device as required.

Here, when the image display device using the optical laminate of the present invention is a liquid crystal display device, the backlight light source is not particularly limited, and a white light emitting diode is preferred. (White LED), the image display device is preferably a VA mode or IPS mode liquid crystal display device having a white light emitting diode as a backlight light source.

The above-mentioned white LED is a phosphor method, that is, a device that emits white by using a combination of a compound semiconductor-emitting light emitting diode and a phosphor emitting blue light or ultraviolet light. Among them, a white light-emitting diode composed of a light-emitting element using a compound semiconductor blue light-emitting diode and a yttrium-aluminum-garnet yellow phosphor has a continuous and wide light-emitting spectrum, and therefore has anti-reflection performance. It is effective to improve the contrast in bright places, and also has excellent luminous efficiency, so it is preferably used as the backlight light source in the present invention. In addition, since white LEDs that consume less power can be widely used, energy saving effects can also be exerted.

In addition, the above-mentioned VA (Vertical Alignment) mode is an operation mode in which, when no voltage is applied, the liquid crystal molecules are aligned perpendicular to the substrate of the liquid crystal cell to display a dark display. Fall down and display clearly.

In addition, the above-mentioned IPS (In-Plane Switching, coplanar switching) mode is a method of displaying liquid crystal by rotating a liquid crystal within a substrate surface by applying a lateral electric field to a comb-shaped electrode pair provided on a substrate of a liquid crystal cell.

The PDP of the image display device described above is provided with a front glass substrate and a back glass substrate. The front glass substrate is formed with electrodes on the surface, and the back glass substrate is arranged opposite to the front glass substrate and sealed in between. The discharge gas forms electrodes and minute grooves on the surface, and red, green, and blue phosphor layers are formed in the grooves. In the case where the image display device of the present invention is a PDP, it is also the one on the surface of the front glass substrate or the front panel (glass substrate or film substrate) provided with the optical laminate.

The image display device described above may also be zinc sulfide, An amine is an ELD device in which a light-emitting body is vapor-deposited on a glass substrate and controls the voltage applied to the substrate to perform display; or an image display device such as a CRT that converts electrical signals into light to produce an image that can be viewed by the human eye. In this case, the above-mentioned optical laminate is provided on the outermost surface of each display device or the surface of its front panel as described above.

[Example]

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

(Evaluation method)

The following evaluations were performed on the optical laminates produced by the respective examples and comparative examples.

(1) Thickness measurement of acrylic substrate

The thickness of the acrylic substrate after the thickness reduction step (B) and the thickness of the resin layer after the hardening step (C) were calculated by the method described in the text of the description.

(2) Adhesiveness

Based on JIS K 5600, the hard coating of the optical laminate is engraved with a checkerboard of 1mm square and a total of 100 grids. Industrial continuous 24mm Cellotape (registered trademark) manufactured by NICHIBAN is used for 5 consecutive peel tests, and the remaining is measured. The number of squares.

The evaluation was performed as follows based on the number of cells that were not peeled. B grade or higher is a good product.

A: 90-100

B: 80-89

C: 50-79

D: less than 50

(3) interference fringes

After the black tape was attached to the surface of the optical multilayer body opposite to the hard coat layer, the presence or absence of interference fringes was evaluated visually under a three-wavelength fluorescent lamp. A good product that cannot recognize the interference fringe is set to A, a case where it is slightly visible is set to C, and a case where it is visible is set to D.

(4) Manufacturing processability

A tensile test was performed at the stage where the free radiation-curable resin composition A was applied to an acrylic substrate and dried. The degree of stretching was set to 2.2 N / cm. The result was evaluated as "A" when it was not broken during stretching, and it was evaluated as "C" if it was slightly broken and a problem occurred in the manufacturing process. Furthermore, since the optical laminated body whose manufacturing processability is "poor" is weakened in the physical properties of the base material, the pencil hardness (JIS K5600-5-4) does not become 2H or more even if the resin layer or hard coating layer is hardened. .

(5) Haze

The haze value (%) of the optical laminate was measured using a haze meter (manufactured by Murakami Color Technology Research Institute, product number: HM-150) in accordance with JIS K-7136, and evaluated by the following evaluation criteria.

A: Haze value is 0.8 or less

C: Haze value exceeds 0.8

(6) Bursting resistance

A Tensilon universal material testing machine (RTG-1310, manufactured by A & D Co., Ltd.) was used to perform a tensile test to evaluate the fracture resistance. The optical laminate was a sample having a width of 10 mm and a length of 100 mm. Tensilon was used to stretch the sample at 100 mm / min. The evaluation was performed based on the following criteria.

A: The case where it will not break even when it is stretched stronger than 15N.

C: Fracture below 15N

(7) Surface resistivity

Using a surface resistivity measuring device (Hiresta HT-210, manufactured by ANALYTECH, Mitsubishi Chemical Corporation), the surface resistivity (Ω / □) was measured on an optical laminate including an antistatic material in a resin layer.

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

Two optical laminated bodies (the optical laminated body of Example 21) containing an anti-blocking agent in the resin layer were prepared and cut into a size of 5 cm × 5 cm, respectively. The acrylic substrate side of one optical laminated body and the resin layer side of the other optical laminated body were opposed to each other, and they were closely adhered under a condition of a pressure of 3.0 kgf / cm ² at 50 ° C. for 30 hours, and then evaluated based on the following criteria.

A: No attachment

C: with stickers

(9) Pencil hardness

Using a pencil for testing specified in JIS-S-6006 and a pencil hardness evaluation method specified in JIS K5600-5-4 (1999), the pencil hardness of the surface on which the hard coat layer was formed was measured under a load of 4.9N.

Example 1

(Manufacture of acrylic substrate)

Melt-knead the granules composed of a copolymer of methyl methacrylate and methyl acrylate (glass transition point: 130 ° C), remove foreign matter with a filter, and extrude and polymerize through the gap of the die by the melt extrusion method Thing. Secondly, while cooling the polymer, one side extended 1.2 times in the longitudinal direction, and 1.5 times in the lateral direction thereafter to obtain an acrylic substrate having a thickness of 40 μm.

(Preparation of Free Radiation Curable Resin Composition A)

Relative to tetraethylene glycol diacrylate (manufactured by Toa Synthesis Co., Ltd., "M240", Molecular weight: 286) 80 parts by mass, 20 parts by mass ("EPT5DL2MIBK") of antimony-doped tin oxide particles (methyl isobutyl ketone dispersion of ATO particles, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.) as functional components ( 4 parts by mass of the initiator ("Irg184" manufactured by BASF) was dissolved in 150 parts by mass of methyl isobutyl ketone (MIBK) to prepare a free radiation-curable resin composition A. Table 1 shows the composition of the free radiation-curable resin composition A.

(Manufacture of optical laminated body)

An uncured resin layer was formed by applying a free radiation-curable resin composition A to an acrylic substrate by a die coating method. It dried at 70 degreeC for 1 minute, the solvent was evaporated, and the resin layer was formed so that the adhesion amount after drying might be 5 g / m <^2> . In a nitrogen environment (oxygen concentration of 500 ppm or less), the obtained coating film was irradiated with ultraviolet rays at an ultraviolet irradiation amount of 200 mJ / cm ² to completely harden the coating film (full cure state), thereby obtaining an optical laminate. Table 1 shows the results obtained by the above evaluation method.

Examples 2 to 28, Comparative Examples 1 to 13

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

(Materials used in Tables 1 to 5)

[Free Radiation Hardening Resin]

TEGDA: Tetraethylene glycol diacrylate (manufactured by Toa Synthesis Co., Ltd., "M240", molecular weight: 286)

PETA: neopentaerythritol triacrylate

[Other free radiation curable resins]

A: Dinepentaerythritol hexaacrylate

B: amine acrylate, manufactured by Japan Synthetic Chemical Industry Co., Ltd., "violet UV1700B"

[Functional materials]

Antistatic agent a: ATO dispersion, manufactured by Mitsubishi Materials Electronic Chemicals, "EPT5DL2MIBK"

Antistatic agent b: Chain-shaped ATO dispersion, manufactured by Nihon Catalyst Chemical Co., Ltd., "ELCOM V3560"

Antistatic agent c: Antimony pentoxide dispersion, manufactured by Niwa Catalyst Co., Ltd., "ELCOM V4504"

Antistatic agent d: quaternary ammonium salt, manufactured by COLCOAT, "COLCOAT NR121X"

Antistatic agent e: quaternary ammonium salt, manufactured by TAISEI FINE CHEMICAL, "1SX3004"

Antistatic agent f: Li ion-based antistatic agent, lithium bis (trifluoromethanesulfonyl) imide, manufactured by Sumitomo 3M, "LJ-603010"

Reactive silicon dioxide a: Solid silicon dioxide, "MIBK-SDL" manufactured by Nissan Chemical Industries, Inc., with an average particle size of 44 nm

Reactive silicon dioxide b: manufactured by Niwa Catalyst Co., Ltd., shaped silicon dioxide, "ELCOM V8803", average particle size is 25nm

Anti-blocking agent: made by CIK NanoTek, solid silicon dioxide, "E65", average primary particle size is 150 ~ 300nm

High refractive index material a: High refractive index amine acrylate, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd., "R1403MB"

High refractive index material b: high refractive index monofunctional monomer, manufactured by Daiichi Kogyo Co., Ltd., "OPPE"

[Solvent]

MIBK: methyl isobutyl ketone

IPA: isopropanol

MEK: methyl ethyl ketone

PGME: propylene glycol monomethyl ether

The optical laminate of the present invention can be preferably used in cathode ray tube display devices (CRT), liquid crystal displays (LCD), plasma displays (PDP), electroluminescence displays (ELD), touch panels, electronic paper, mobile Displays for telephones, especially high-definition displays.

Claims (3)

A method for manufacturing an optical laminate, which sequentially performs the following steps: a coating step (A), which coats an acrylic substrate with a free radiation-curable resin composition A containing at least a functional component to form an uncured resin Layer; step (B) of reducing the thickness of the acrylic substrate by dissolving the acrylic substrate by the unhardened resin layer, and reducing the thickness of the acrylic substrate by 1.0 to 15.0%; The uncured resin layer is cured to form a resin layer; thereby, the functional component is biased toward the surface side of the resin layer. For example, the method for manufacturing an optical laminated body according to item 1 of the patent application scope, wherein the free radiation-curable resin composition A contains polyalkylene glycol di (meth) acrylate. An optical laminated body is formed by sequentially performing the following steps to bias a functional component toward the surface side of the resin layer. The above step is: a coating step (A), which is coated on an acrylic substrate and contains The non-hardened resin layer is formed by the radiation-hardenable resin composition A of the functional component, and the thickness reduction step (B) is to dissolve the acrylic base material by the unhardened resin layer and reduce the thickness of the acrylic base material by 1.0. ~ 15.0%; and a curing step (C), which hardens the uncured resin layer to form a resin layer.