JP2006110988A - Plastic film and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a functional film (hard coat film) free from occurrence of interference spots under a three wavelength fluorescent lamp even if the refractive index of a primer layer is substantially different from that of a plastic film support in a constitution of the transparent plastic film support, the primer layer, and a functional layer (hard coat layer). <P>SOLUTION: In the plastic film, the primer layer (B) having the film thickness of ≤1 μm and the functional layer (C) having the film thickness of ≥1 μm are laminated in this order at least at one surface at least of the transparent plastic film support (A), wherein the transparent plastic film support (A) and the functional layer (a hard coat layer, for example) (C) have no substantial difference in refractive index at a wavelength of 546 nm and also, the transparent plastic film support (A) and the primer layer (B) are substantially different in refractive index at a wavelength of 546 nm, and the film thickness d<SB>p</SB>of the primer layer (B) satisfies the formula, d<SB>p</SB>=(N×546±50)/(2n<SB>p</SB>) nm, wherein n<SB>p</SB>is the refractive index of the primer layer (B), N is a natural number. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a plastic film that prevents interference spots (unevenness) and improves visibility. In particular, the present invention relates to a functional plastic film in which functional layers such as a hard-coated plastic film, a pressure-sensitive adhesive layer-attached plastic film, and an antireflection layer are laminated so that interference spots are hardly visible even under a three wavelength fluorescent lamp.
The present invention also relates to an image display device provided with the plastic film of the present invention.

In recent years, transparent plastic film substrates have been attached to plastic products, LCDs, displays with surfaces formed of plastic materials, mobile phone and mobile game display boards, touch panels, etc. to provide scratch resistance, glass products and CRT, Demand is growing as a base material such as a hard coat film or an antireflection film for imparting functions such as scattering prevention, antireflection, antifouling, and antistatic properties on the surface of a glass display such as PDP.
Among them, polyester resin-based films, particularly polyethylene terephthalate (PET) biaxially stretched films have excellent mechanical properties, flame resistance, chemical resistance, etc. The growth is remarkable.

  When a functional film is formed using these transparent plastic film base materials, many of them are several μm to about 50 μm made of organic compound resin directly on the base material or through a thin easy adhesion layer (primer layer) or the like. A functional layer, for example, a hardened layer such as a hard coat layer, is formed. The refractive index (plane direction) of the PET film is about 1.65, whereas the refractive index of the hard coat layer formed of an organic compound such as an acrylic resin is usually 1.50 to 1.56 centering on 1.53. Yes, there is a refractive index difference of 0.10 or more. For this reason, the functional film of which the base material is PET has (1) high reflectance at the interface, (2) interference spots occur due to light interference between reflection at the interface and reflection at the surface, (3 ) There is a problem that interference spots occur due to interference of reflected light on the front and back surfaces of PET. From these three problems (1), (2), and (3), it is possible to visually recognize articles such as bonded image display devices. It may worsen the nature or impair the sense of quality.

  In particular, interference spots are emphasized under a three-wavelength fluorescent lamp in which the ratio of the emission line spectral component is high in the emission spectrum. In recent years, the spread of three-wavelength fluorescent lamps has been rapidly progressing in ordinary households, and the problem of interference spots has become important. Therefore, the use application of the functional film based on PET film is remarkably limited. Otherwise, functional films are being sent out to the world with the problem of interference spots. In fact, in the field of large flat-screen televisions where PET film is used as a base material, interference spots are observed in most of the antireflection films currently mounted.

  Interference spots occur due to subtle film thickness unevenness of a hardened layer such as a hard coat layer of about several μm to 50 μm formed on the substrate or a plastic film substrate. As a solution for the problem of film thickness unevenness, for example, a hard coat layer of a synthetic resin lens is usually formed by a film forming method with less coating unevenness such as a dipping method or a vapor deposition method. In contrast, plastic films and functional films produced by continuous WET coating on roll films with a width of 30 cm or more and a length of 10 m or more are comparable to synthetic resin lenses formed by a dipping method or a vapor deposition method in batch mode. At present, the film thickness accuracy to be obtained is not obtained. Accordingly, it is not possible to eliminate the delicate coating unevenness that occurs randomly in the conventional coating method.

Focusing on making the refractive index of the hard coat layer close to the refractive index of the PET film for the purpose of preventing such interference spots, an ionizing radiation curable resin containing metal oxide ultrafine particles having a high refractive index is used as the PET film. It is coated on a high refractive index film such as a hard coat layer to form a hard coat layer, or a siloxane thermosetting resin containing high refractive index metal oxide fine particles is applied and cured to hard coat. It is practiced to form the layer directly on the PET film. (For example, Patent Document 1) However, although these methods are surely effective in reducing interference spots, the composition of the hard coat layer is required because the refractive index of the hard coat layer must match the refractive index of the plastic film substrate. Give significant constraints. Further, the hard coat layer must be directly laminated on the PET film, and sufficient adhesion cannot be obtained.
Since PET film has crystal orientation, it has high surface cohesion and poor adhesion to various materials. In general, a hard coat layer is laminated through a primer layer (an easy-adhesion layer) that has been devised in various ways to provide adhesion.
In the configuration of generally used PET film / primer layer / hard coat layer, it is conceivable to prevent interference spots by combining the refractive indexes of all three layers. However, the refractive index of the primer layer must match the refractive index of the PET film. It also imposes significant constraints on the composition of the primer layer. Further, it is necessary to add high refractive index metal oxide ultrafine particles in order to increase the refractive index of the primer layer. When metal oxide fine particles are added to the hard coat layer or primer layer, the cohesive strength of the layer is lowered. In particular, the cohesive strength of the binder of the easy-adhesion layer is set lower than the cohesion of the hard coat layer in order to provide easy adhesion, and the addition of metal oxide ultrafine particles makes it more cohesive than the hard coat layer. It decreases, causing film peeling and the like.

In addition, a method has been proposed in which scattering is introduced to prevent interference spots (see, for example, Patent Document 2 and Patent Document 3). However, these methods are effective in preventing interference spots, but a new haze problem arises and the usage is severely limited.
Furthermore, a method has been proposed in which interference fringes can be prevented by a buffer layer having a refractive index intermediate between the hard coat layer and the PET film at 3 to 50 μm between the hard coat layer and the PET film (for example, a patent) As a result of additional tests, the effect on interference spots under the above conditions was insufficient.

In order to solve such problems, the present inventors have disclosed a method for solving the problem of interference spots by specifying the refractive index and film thickness of the primer layer without restricting the composition of the hard coat layer. Disclosed.
Since this method does not impose any restrictions on the composition of the hard coat layer, the application range is wide in terms of the degree of freedom of the hard coat layer composition. However, even in this method, the refractive index of the primer layer must be uniquely determined from the refractive indexes of the hard coat layer and the plastic film substrate, which limits the composition of the primer layer.
Therefore, in a hard coat film having a PET film / primer layer / hard coat layer configuration using a high refractive index plastic film substrate such as a PET film, the degree of freedom of the primer layer composition supplementing the technique disclosed in Patent Document 5 It has been desired to develop a hard coat film having a high refractive index, that is, no occurrence of interference spots under a three-wavelength fluorescent lamp in which the refractive index of the primer layer can be freely changed.

  The degree of freedom of the primer layer from the viewpoint of the refractive index is not limited to a hard coat film using a high refractive index plastic film substrate. There is a similar need for a plastic film substrate having a relatively low refractive index, such as a TAC film. For example, in the structure of a TAC film / primer layer / hard coat layer, it is widely practiced that the primer layer contains conductive metal oxide fine particles to form an antistatic layer. In this case, since the conductive metal oxide fine particles have a high refractive index, the refractive index of the primer layer is higher than that of the TAC film, resulting in a substantial refractive index difference. Therefore, reflection occurs at the interface between the antistatic layer and the TAC film, which is the primer layer, or the interface between the antistatic layer and the hard coat layer, and under three-wavelength fluorescent lamps, interference spots due to the film thickness unevenness of the hard coat layer occur. appear.

  In summary, the composition of the transparent plastic film substrate / primer layer / functional layer (hard coat layer) allows the composition of the primer layer to be freely changed from the viewpoint of the refractive index, that is, the refractive index of the primer layer is substantially In particular, there has been a demand for the development of a functional film (hard coat film) that does not generate interference spots under a three-wavelength fluorescent lamp even if it has a refractive index different from that of the plastic film substrate.

Japanese Patent No. 3383039 JP-A-8-197670 JP-A-10-283122 JP 2000-347003 A WO04 / 000550 pamphlet

In view of the above situation, an object of the present invention is to suppress interference spots under a three-wavelength fluorescent lamp in a plastic film provided with a hard coat layer, an adhesive layer, etc. on a substrate, and to have a degree of freedom in the primer layer composition Is to provide a plastic film with a high primer layer. In particular, an object of the present invention is to provide a hard coat film, a plastic film with a pressure-sensitive adhesive layer, and a plastic film with a primer layer suitable as a base material for a functional film with reduced interference spots.
Another object of the present invention is to provide a functional film having various functions, particularly an antireflection film having a low reflectance, using the plastic film as a base material, and further comprising the plastic film. An object is to provide an image display device.

  As a result of intensive studies, the inventor can freely change the refractive index of the primer layer by optimizing the refractive index of the functional layer on the transparent plastic film substrate and the film thickness of the primer layer. A plastic film that can freely change the composition of the primer layer and does not cause interference spots under a three-wavelength fluorescent lamp has been developed, and the present invention has been completed.

Specifically, it has been found that the above problem can be achieved by the following means.
1. A plastic film in which a primer layer having a film thickness of 1 μm or less and a functional layer having a film thickness of 1 μm or more are laminated in this order on at least one surface of a transparent plastic film substrate, the transparent plastic film substrate and the function The refractive index is substantially different at a wavelength of 546 nm, the refractive index of the transparent plastic film substrate and the primer layer is substantially different at a wavelength of 546 nm, and the thickness d _{P of the} primer layer is expressed by the following formula ( A plastic film characterized by satisfying 1).
Formula (1)
d _P = (N × 546 ± 50) / (2n _P ) (nm)
However, n _P is the refractive index of the primer layer, N is a natural number.

2. Plastic film according to claim 1 where the film thickness d _P of the primer layer is characterized by satisfying the following equation (2).
Formula (2)
d _P = (N × 546 ± 25) / (2n _P ) (nm)
3. Plastic film as described in 2 film thickness d _P of the primer layer is characterized by satisfying the following equation (5).
Formula (5)
d _P = (N × 546 ± 10) / (2n _P ) (nm)

4). 4. The plastic film as described in any one of 1 to 3 above, wherein N is a natural number of 3 or less.
5. 4. The plastic film as described in any one of 1 to 3 above, wherein N is 1 or 2.
6). Said N is 1, The plastic film in any one of said 1-3 characterized by the above-mentioned.

7). 7. The plastic film as described in any one of 1 to 6 above, wherein the base material has a refractive index n _S of 1.56 or more and less than 1.90.
8). 6. The substrate is a polyester film. The plastic film as described in.
9. 9. The plastic film as described in 8 above, wherein the substrate is a polyethylene terephthalate (PET) film.
10. 10. The plastic film as described in 9 above, wherein the substrate is a polycarbonate film.

11. 11. The plastic film as described in any one of 1 to 10 above, wherein the base material has a refractive index n _S of 1.50 or less.
12 12. The plastic film as described in 11 above, wherein the substrate is a cellulose ester film.
13. 13. The plastic film as described in 12 above, wherein the substrate is a triacetyl cellulose (TAC) film.

14 14. The plastic film as described in any one of 1 to 13 above, wherein the primer layer contains metal oxide fine particles.
15. 15. The plastic film as described in 14 above, wherein the primer layer contains conductive metal oxide fine particles and has antistatic properties.
16. 16. The plastic film as described in 15 above, wherein the conductive metal oxide fine particles are particles of ATO (antimony-doped tin oxide), PTO (phosphorus-doped tin oxide) or ITO (tin-doped indium oxide).
17. The plastic film as described in any one of 1 to 16 above, wherein the primer layer is an adhesive undercoat layer.

18. The hard coat film as described in any one of 1 to 17 above, wherein the functional layer is a hard coat layer.
19. 19. The plastic film as described in any one of 1 to 18 above, wherein the functional layer contains metal oxide fine particles.
20. 20. The plastic film as described in 19 above, wherein the functional layer is an antistatic layer containing conductive metal oxide fine particles.
21. 21. The plastic film as described in 20 above, wherein the conductive metal oxide fine particles are particles of ATO (antimony-doped tin oxide), PTO (phosphorus-doped tin oxide) or ITO (tin-doped indium oxide).

22. The plastic film as described in any one of 1 to 21 above, wherein the functional layer contains inorganic fine particles mainly composed of titanium dioxide.
23. 23. The plastic film as described in 22 above, wherein the functional layer contains inorganic fine particles containing titanium dioxide as a main component and containing at least one element selected from the group consisting of cobalt, aluminum and zirconium.
24. 24. The plastic according to 23, wherein the total content of elements selected from the group consisting of cobalt, aluminum and zirconium is 0.5 to 3% by mass with respect to the content of titanium dioxide. the film.
25. The plastic film as described in any one of 1 to 24 above, wherein the functional layer contains hollow silica particles.

26. The plastic film as described in any one of 1 to 21 above, wherein the functional layer is formed from a curable composition containing an organic solvent.
27. 27. The plastic film as described in any one of 1 to 26, wherein the hard coat layer is made of a curable composition that is cured by irradiation with active energy rays.

28. 28. The plastic film according to any one of 1 to 27, wherein the functional layer is a pressure-sensitive adhesive layer.
29. A plastic film in which another primer layer (hereinafter referred to as “primer layer Q”) and an adhesive layer are laminated in this order on the surface of the transparent plastic film substrate on which the primer layer is not laminated, The film substrate and the pressure-sensitive adhesive layer have substantially different refractive indices at a wavelength of 546 nm, and the refractive index n _Q and the film thickness d _{Q of the} primer layer Q satisfy the following formulas (3) and (4). The plastic film as described in any one of 1 to 27 above.
Formula (3)
n _Q = (n _S × n _A ) ^1/2 ± | n _S × n _A | / 4
However, n _S is the refractive index of the substrate, the n _A is the refractive index of the adhesive layer.
Formula (4)
d _Q = (M × 546 ± 50) / (4n _Q ) (nm)
However, M is a natural number.
30. Plastic film as described in 29 the refractive index n _Q of the primer layer Q is characterized by satisfying the following equation (6).
Formula (6)
n _Q = (n _S × n _A ) ^1/2 ± | n _S −n _A | / 8
31. Plastic film as described in 29 the thickness d _Q of the primer layer Q is characterized by satisfying the following equation (7).
Formula (7)
d _Q = (M × 546 ± 25) / (4n _Q ) (nm)
32. Plastic film as described in 31 the thickness d _Q of the primer layer Q is characterized by satisfying the following equation (8).
Formula (8)
d _Q = (M × 546 ± 10) / (4n _Q ) (nm)
33. 33. The plastic film as described in any one of 29 to 32, wherein M is a natural number of 3 or less.
34. 33. The plastic film as described in any one of 29 to 32 above, wherein M is 1 or 2.
35. 33. The plastic film as described in any one of 29 to 32 above, wherein M is 1.
36. The plastic film according to any one of claims 29 to 32, wherein the primer layer Q contains conductive metal oxide fine particles and has antistatic properties.

37. 37. The functional plastic film according to any one of 1 to 36, further comprising a functional layer other than the hard coat layer and the pressure-sensitive adhesive layer.
38. 38. The antireflection film, wherein the functional layer according to 37 is an antireflection layer.
39. The antireflection film as described in 38 above, wherein the minimum wavelength of reflectance is 520 nm to 570 nm.
40. 39. The antireflection film as described in 38 above, wherein the minimum wavelength of reflectance is from 536 nm to 556 nm.
41. 41. The antireflection film as described in any one of 38 to 40 above, wherein the surface reflectance of the antireflection layer is 3% or less.
42. 41. The antireflection film as described in any one of 38 to 40 above, wherein the surface reflectance of the antireflection layer is 1.5% or less.
43. 43. An image display device comprising the plastic film according to any one of 1 to 42 above.

  According to the present invention, a primer layer having a specific film thickness and a functional layer having a refractive index equivalent to that of the base film are laminated in this order on the base film, thereby causing interference spots even under a three-wavelength fluorescent lamp. It is possible to obtain a plastic film with no visibility and good visibility. By using the plastic film of the present invention, it is possible to provide a transparent functional film free from interference spots even under a three-wavelength fluorescent lamp. The plastic film of the present invention is a glass scattering prevention film, an adhesive tape, a transparent sticker substrate, and the transparent functional film is a surface of an image display device such as CRT, LCD, PDP, FED, touch panel, glass plate, It is suitable as a protective film for plastic plates and the like.

Hereinafter, the present invention will be described in detail.
The plastic film of the present invention has a transparent plastic film / primer layer / functional layer structure, and the composition of the primer layer can be freely changed from the viewpoint of refractive index, and is observed under a fluorescent lamp, particularly under a three-wavelength fluorescent lamp. It is a plastic film that suppresses easy interference spots. Specifically, a hard coat film having a hard coat layer, a plastic film with an adhesive layer having an adhesive layer, a functional film provided with a functional layer on the film, and an antireflection film provided with an antireflection layer Corresponds to the plastic film with suppressed interference spots of the present invention.

  The interference spots taken up in the present invention are provided, for example, on a high refractive index substrate film typified by PET (polyethylene terephthalate) with a layer having a large refractive index difference from the substrate such as a hard coat layer and an adhesive layer. In this case, the reflectance at the interface between the layer and the substrate is increased, and the light reflected from the interface and the light reflected from the film surface are generated. The interference is affected by subtle changes in film thickness of the base material such as the hard coat layer and the base material, and generates spots (unevenness) that are observed in stripes or spots. Although this phenomenon is expressed as interference fringes, Newton rings, or interference fringes depending on published patents and documents, the appearance of unevenness caused by the same mechanism is not necessarily striped, ring-shaped or spot-like, In particular, if there is a thin layer (several μm or less), it may be observed in the form of spots. In the present invention, based on this situation, it is expressed as interference spots.

  The interference spots taken up in the present invention are the same in the structure of TAC film / primer layer / hard coat film even when a low refractive index base film represented by TAC (triacetyl cellulose) is used as the base. If the layer has a high refractive index, strong interference spots are observed. For example, when the primer layer is a conductive layer containing conductive metal oxide fine particles, the conductive metal oxide fine particles have a high refractive index, and the refractive index of the primer layer itself is also high.

When such interference spots occur, the refractive index difference (absolute value) between the layer provided on the base material and the base material is usually 0, as described in JP-A-7-15902. It is supposed to occur when there is 03 or more.
Therefore, in the present invention described below, when there is a substantial difference between the refractive index of the hard coat layer or the pressure-sensitive adhesive layer and the refractive index of the substrate, the effect of preventing interference spots when the difference is 0.03 or more. Appears prominently. The effect is greater when the difference in refractive index is 0.06 or more, and the effect is greater when it is 0.10 or more.

  It is well known that the distance at which light can interfere, that is, the coherent length (coherence distance), is approximately determined by the wavelength and bandwidth (emission spectrum width) of light and is expressed by the following equation (for example, JD Rancourt, “OPTICAL THIN FILMS USER HANDBOOK”, Optical Coating Laboratory, Inc. 11 (1996)).

Coherent length L = λ ² / Δλ (Δλ: bandwidth)

  From this equation, it can be said that light from a light source including a spectrum having a narrow bandwidth Δλ has a long coherent length, so that interference spots are easily observed. An emission line spectrum having a narrow bandwidth due to emission of mercury atoms by discharge (546.074 nm). It can be understood that interference spots are observed under a three-wavelength fluorescent lamp with a high component ratio of the emission spectrum with a narrow bandwidth.

The essential solution to this interference spot is to reduce the reflected light between the hard coat layer / substrate of the three-wavelength fluorescent lamp emission line spectral component, preferably by eliminating the reflected light on the surface of the hard coat layer. It is to prevent the interference with. Here, between hard coat layer / substrate means the vector sum of the reflected light at the hard coat layer / primer layer interface and the reflected light at the primer layer / substrate interface.
This also applies to layers that cause interference spots other than the hard coat layer, such as a pressure-sensitive adhesive layer, and the essential solution to the interference spots is a substrate / adhesive of a spectral component of a three-wavelength fluorescent lamp emission line. By reducing the reflected light between the layers, and preferably eliminating it at all, it is possible to prevent interference with the reflected light on the surface of the hard coat layer. Thereby, the interference spots resulting from the total film thickness unevenness of the hard coat layer and the plastic film substrate can be reduced or eliminated.

In the plastic film of the present invention, a primer layer having a thickness of 1 μm or less and a functional layer having a thickness of 1 μm or more are provided on a transparent plastic film substrate, and the refractive index of the functional layer and the thickness of the primer layer are optimized. Thus, the reflected light generated between the base material and the functional layer is reduced to prevent the occurrence of interference spots.
A hard coat film in which a primer layer P and a hard coat layer are laminated in this order on at least one surface of a transparent plastic film substrate will be described as an example. In a system in which the refractive index of the transparent plastic film substrate and the primer layer are substantially different, the substantial difference in refractive index at a wavelength of 546 nm between the transparent plastic film substrate and the hard coat layer is eliminated, and the film thickness d _{P of the} primer layer is set as follows: Interference spots are reduced or eliminated by approaching the film thickness given by Equation (9).
Formula (9)
d _P = (N × 546) / 2n _P (nm)
Here, N is a natural number. n _P is the refractive index of the primer layer.

  The same applies to the plastic film provided with a functional layer other than the hard coat layer, such as a plastic film with an adhesive layer in which a primer layer and an adhesive layer are laminated in this order on at least one surface of a transparent plastic substrate. It is sufficient to satisfy various conditions (conditions regarding the difference in refractive index from the substrate and the reflectance at the interface).

Here, Formula (9) will be described. The emission spectrum of the three-wavelength fluorescent lamp includes emission line spectra in the vicinity of 440 nm, 545 nm, and 610 nm, and these emission lines can cause interference spots. When the interference spots under the three-wavelength fluorescent lamp were observed using the three primary color filters of red, green, and blue, strong interference spots were seen when viewed with the green filter. The reason is that the green region includes an emission line spectrum of 546.074 nm due to mercury atom emission in the vicinity of 545 nm, the bandwidth is very narrow, and interference is likely to occur in terms of coherent length. Considering that human visibility is high in green, it is considered that the contribution of 546 nm is substantially very large.
Actually, when the primer layer of Formula (9) that zeroes the reflected light with a wavelength of 546 nm based on the hypothesis by interference of the reflected light on both surfaces of the primer layer, the interference spots were reduced very effectively. For this reason, it has been found that the primer layer thickness design according to the formula (9) for zeroing the reflected light of 546 nm by thin film interference is effective in preventing interference spots under a three-wavelength fluorescent lamp.

Hereinafter, the plastic film of the present invention will be described in detail.
The base material used for this invention is a transparent plastic film base material, and a film form, a sheet | seat, and a plate-shaped thing are preferable. The “film” referred to in the present invention includes not only a film shape but also a sheet shape or plate shape as a substrate.

  Since the refractive index of a hard coat layer or pressure-sensitive adhesive layer made of an ordinary organic compound is usually around 1.53, first, in the present invention, when using a substrate having a high refractive index (1.56 or more), the substrate and the hard coat layer are used. It is conceivable to treat interference spots caused by the difference in the refractive index of the layers. In this case, the refractive index of the base material is preferably 1.56 or more and less than 1.90, and more preferably 1.60 or more and less than 1.70. A plastic film formed from a polymer having a high refractive index is preferable. Examples of the polymer having a high refractive index include polycarbonate, polyester (eg, polyethylene terephthalate, polyethylene naphthalate, poly-1,4-cyclohexanedimethylene terephthalate, Polyethylene-1,2-diphenoxyethane-4,4′-dicarboxylate, polybutylene terephthalate) polysulfone, polyarylate and polystyrene (eg, syndiotactic polystyrene). Of these, polycarbonate and polyethylene terephthalate are preferable.

  Even when a plastic film substrate having a low refractive index (less than 1.50) is used, when the primer layer is made to contain conductive metal oxide fine particles and the primer layer is used as an antistatic layer, the primer layer The refractive index is high, and the present invention can be preferably applied. Such a substrate is preferably a plastic film formed from a polymer having a low refractive index. Examples of the polymer having a low refractive index include cellulose esters (cellulose acetate (eg, triacetyl cellulose, cellulose acetate butyrate), cellulose tributyrate), PMMA (polymethyl methacrylate), PP (polypropylene), and FEP (tetrafluoroethylene). Fluorine resin film such as (hexafluoropropylene polymer). Of these, triacetylcellulose is preferable.

  “Transparent” of the transparent substrate means that the light transmittance in the visible light region is 80% or more, and preferably 86% or more. When a plastic film with an adhesive layer is used as a sticker or the like, there may be a printing layer between the primer layer and the adhesive layer, and the light transmittance may be partially 80% or less.

From the viewpoint of the visibility of the plastic film, the haze of the plastic film is preferably 3.0% or less, more preferably 2.0% or less, and particularly preferably 1.0% or less. The haze of the transparent plastic substrate itself is preferably 50% or less, more preferably 25% or less, and particularly preferably 10% or less. However, since it is required to have low haze particularly in applications where linear transmitted light is important, it is preferably 3.0% or less, more preferably 2.0% or less, and 1.0% or less. It is particularly preferred that
The lower limit of the haze is preferably 0%, but is suitably 0.01% from the viewpoint of measurement and the like.

When the substrate is in the form of a film, the thickness of the substrate is preferably 20 to 300 μm, and more preferably 80 to 200 μm. If the thickness of the base film is too thin, the film strength is weak, and if it is thick, the rigidity becomes too large. In the case of a sheet form, the thickness of the substrate may be in a range that does not impair the transparency, and those having a thickness of 300 μm to several mm can be used.
When the thickness of the substrate is 1 mm or less, particularly 300 μm or less, interference spots may be seen due to interference between reflected light on the substrate surface and the back surface under a light source containing a bright line component in the visible light region, for example, a three-wavelength fluorescent lamp. In the present invention, interference spots on the front and back surfaces of the substrate can be reduced by providing the primer layers on both sides. In general, a synthetic resin lens has a large thickness, and interference spots due to reflected light on the front and back surfaces do not occur. This is the fundamental difference between synthetic resin lenses and films.

  As described above, the present invention significantly reduces the reflectance at the interface by providing an antireflection primer layer (primer layer P, primer layer Q) at the interface between the hard coat layer or the pressure-sensitive adhesive layer and the substrate. It makes the interference spots almost invisible.

If the hard coat film of the present invention, the refractive index n _P of the primer layer P, the refractive index n _H of the refractive index of the substrate n _S or hardcoat layer is substantially different, the difference is 0.03 or more Occasionally interference spots occur, and the countermeasure effect appears. The effect is greater when the difference in refractive index is 0.06 or more, and the effect is greater when it is 0.10 or more.

At least one surface of the transparent plastic film base material is laminated with a primer layer P having a film thickness of 1 μm or less and a functional layer having a film thickness of 1 μm or more in this order. And the transparent plastic film and the primer layer P have different refractive indexes at a wavelength of 546 nm, and the film thickness d _P of the primer layer P approaches the film thickness given by the following formula (9). Can be reduced or eliminated.
Formula (9)
d _P = (N × 546) / 2n _P (nm)
Here, N is a natural number. n _P is the refractive index of the primer layer.

In the above description, the transparent plastic film substrate and the functional layer have substantially no difference in refractive index at a wavelength of 546 nm. When the refractive index of the functional layer and the refractive index of the transparent plastic film are measured at a wavelength of 546 nm, both refractive indexes This means that the difference is not at least 0.03 or more considering the measurement error.
The difference in refractive index between the transparent plastic film substrate and the primer layer P at a wavelength of 546 nm is that the refractive index difference between the transparent plastic film substrate and the primer layer P is at least 0.03 or more in consideration of measurement errors when the refractive index is measured at 546 nm. Means that.
Further, the fact that the refractive index of the transparent plastic film substrate and the pressure-sensitive adhesive layer are substantially different at a wavelength of 546 nm means that when the refractive index is measured at 546 nm, the difference in refractive index between the two takes into account the measurement error. 03 or more means different.

  By eliminating the difference between the refractive index of the transparent plastic film substrate and the refractive index of the functional layer at 546 nm where the emission line components of the three-wavelength fluorescent lamp are concentrated, the amplitude of the reflected light at the functional layer / primer layer interface and the primer layer / The amplitude of the reflected light at the transparent plastic interface can be adjusted, and by satisfying Expression (9), the phase of the two reflected lights can be shifted by 180 ° around 546 nm. Therefore, both reflected lights interfere near 546 nm, and the vector sum of the reflected lights can be brought close to zero.

The thinner the primer layer thickness d _P , the more preferable it is because interference at both interfaces is more likely to occur, so that the antireflection effect increases. Therefore, the natural number N ≦ 3 is preferable, N ≦ 2 (d _P = λ / n _P or d _P = λ / 2n _P ) is more preferable, and N = 1 (d _P = λ / 2n _P Is particularly preferred.
As described above, the emission line component near 546 nm in the emission spectrum of the three-wavelength fluorescent lamp has a high contribution, but the emission line spectrum near 610 nm also contributes to interference spots. I learned from the research.
Wavelength can be the film thickness d _P in the case of 546nm as well as the primer layer is to reduce the interference spots due to the wavelength 610nm by approaching the thickness given by the following equation (10).
Formula (10)
d _P = (J × 610) / 2n _P (nm)
Where J is a natural number. n _P is the refractive index of the primer layer.
In the formula (9), when N ≦ 3, the deviation of the film thickness d _{P from} the formula (10) is relatively small, and there is an effect of reducing reflected light having a wavelength of 610 nm. From this point, N ≦ 3 is preferable, and N ≦ 3 2 is more preferable, and N = 1 is particularly preferable.

The film thickness is preferably closer to the film thickness given by Equation (9), and the design wavelength is preferably a value calculated by Equation (9). However, even if the film thickness deviates from Equation (9) for reasons such as manufacturing film thickness variation, the intensity of interference spots is reduced to 15% or less as long as the deviation width is within 50 / n _P (nm). This is preferable because it can be reduced and has a clear effect of reducing interference spots. Further, if it is within 25 / n _P (nm), the intensity of interference spots can be made 5% or less, more preferably within 10%, if it is within 10 / n _P (nm), Particularly preferred.
In addition, by increasing the design wavelength within a range within 30 / n _P (nm) with respect to the value calculated from Equation (9), interference spots caused by the bright line near 610 nm of the three-wavelength fluorescent lamp are further reduced. This embodiment is also preferable because it can be performed.

When the hard coat film is bonded to, for example, an image display device or the like, usually, an adhesive layer is provided on the surface opposite to the side on which the hard coat of the substrate is provided, and the substrate is bonded via the adhesive layer.
In this case, the hard coat layer H / primer layer P / plastic film substrate S / primer layer Q / adhesive layer A is constructed, and the refractive index difference between the adhesive layer A and the plastic film substrate S is eliminated. can the thickness d _Q provided a primer layer Q lowers the reflectivity of the interface between the plastic film substrate S and the pressure-sensitive adhesive layer a by satisfying the following formula, preferred.
Formula (11)
d _Q = (N × 546 ± 50) / 2n _Q
N is a natural number.

  At this time, the compositions of the primer layer P and the primer layer Q may be different as long as they satisfy the formulas (1) and (11). N in Formula (1) may be different from N in Formula (11). From the viewpoint of productivity, it is also a preferable embodiment to provide the same primer layer.

When laminating a hard coat film to an article such as a window glass, the reflection of the interface between the adhesive layer and the bonded article is eliminated by adjusting the refractive index of the adhesive layer to the refractive index of the bonded article and eliminating the reflected light at the interface. Can be prevented. When the refractive index of the plastic film substrate and the refractive index of the bonded article are greatly deviated, a substantial difference occurs between the refractive index n _S of the plastic film substrate and the refractive index n _A of the pressure-sensitive adhesive layer. In this case, the reflectance of the plastic film substrate S and the pressure-sensitive adhesive layer A is satisfied by satisfying the following two conditions with the configuration of the hard coat layer H / primer layer P / plastic film substrate S / primer layer Q / adhesive layer A. Can be reduced.

The refractive index n _S of the base _material, the thickness primer layer Q when the refractive index was n _A pressure-sensitive adhesive layer satisfies the refractive index n _Q and the following equation is satisfied (4) the following equation (3) d Plastic film characterized by having a _Q (3)
n _Q = (n _S × n _A ) ^1/2 ± | n _S −n _A | / 4
Formula (4)
d _Q = (M × 546 ± 50) / (4n _Q ) (nm)
However, M is a natural number.

Furthermore, in order to reduce the reflectance between the pressure-sensitive adhesive layer A and the plastic film substrate S, the refractive index n _Q preferably satisfies the following formula (6).
Formula (6)
n _Q = (n _S × n _A ) ^1/2 ± | n _S −n _A | / 8

When the refractive index of the base material is n _S and the refractive index of the pressure-sensitive adhesive layer is n _A , the primer layer Q is close to the refractive index given by the following formula (12), whereby the emission line components of the three-wavelength fluorescent lamp are concentrated. The amplitude of the reflected light at the base material / primer layer Q interface and the reflected light at the primer layer / adhesive layer interface can be matched at 546 nm, and further, the film thickness is brought closer to the value given by the following formula (13), to 546 nm. The phase of the two reflected lights can be shifted by 180 ° in the vicinity. Therefore, both reflected lights interfere near 546 nm, and the vector sum of the reflected lights can be brought close to zero.
Formula (12)
n _Q = (n _S × n _A ) ^1/2
A plastic film having a refractive index n _Q satisfying the following formula and a film thickness d _Q satisfying the following formula (13): Formula (13)
d _Q = (M × 546) / (4n _Q )

  Formulas (3) and (6) are obtained by adding a width corresponding to the difference in refractive index between the base material and the pressure-sensitive adhesive layer in Formula (12), and the smaller the width, the better.

  When the hard coat layer is laminated by applying and curing a curable composition containing an organic solvent, the primer layer P is exposed to the solvent and is subjected to the stress of curing shrinkage. On the other hand, the primer layer on the pressure-sensitive adhesive layer side is not significantly affected by curing shrinkage, and the pressure-sensitive adhesive layer is adhered to the back surface of the hard coat layer by, for example, forming the pressure-sensitive adhesive layer on a release paper by an indirect method If the method of laminating is used, neither the influence of organic solvents nor the influence of curing shrinkage is affected. Therefore, generally, the primer layer Q on the pressure-sensitive adhesive layer side has few requirements that must be satisfied with respect to the primer layer P on the hard coat layer side, and therefore, the above-described aspect in which only the degree of freedom of the primer layer P is ensured is also a preferable aspect. .

In the above configuration, the refractive index n _A of the pressure-sensitive adhesive needs to match the refractive index n _M of the plastic film substrate refractive index n _S or the stuck article.
Various pressure-sensitive adhesives usually have a refractive index of about 1.40 to 1.70. An acrylic material having a refractive index of 1.50 to 1.55 is mainly used for pasting the transparent film as in the present invention, but the refractive index n of the adhesive is not limited by this refractive index range. By adjusting the refractive index (n _M ) of the surface material of the object (for example, an image display device) to which _A is attached, the reflectance of the hard coat and the adhesive is suppressed, and the adhesive and the adhesive are further applied. The reflectivity at the interface of the wearing object can be minimized. In recent years, pressure-sensitive adhesives or adhesives having various refractive indexes have been developed (for example, Fumio Ide et al., “Optical Transparent Resin”, Technical Information Association (2001), p. 177-180). When combined with these adhesives, the range of application is extremely wide.

(Primer layer)
When a polyester film is used as a substrate, the polyester film has high surface cohesiveness due to crystal orientation and poor adhesion to various materials. For the purpose of improving the adhesion between the polyester film and the hard coat layer, a surface treatment can be applied to one side or both sides of the polyester film by an oxidation method, an unevenness method, or the like as desired. Examples of the oxidation method include corona discharge treatment, glow discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like.

The primer layer can also be set as an undercoat layer of the substrate. Examples of the material for the undercoat layer include copolymers such as vinyl chloride, vinylidene chloride, butadiene, (meth) acrylic acid ester, and vinyl ester, or water-soluble polymers such as latex, low molecular weight polyester, and gelatin. Further, the undercoat layer may contain tin oxide, a metal oxide such as tin oxide / antimony oxide composite oxide, tin oxide / indium oxide composite oxide, or an antistatic agent such as a quaternary ammonium salt.
Moreover, in order to improve adhesiveness with a base material and a hard-coat layer, easy-adhesiveness can be added and the function as an adhesive subbing layer can also be provided to a primer layer. In order to add easy adhesiveness, a primer layer may be provided by applying an easily adhesive coating material.

  As the primer layer coating liquid, an organic solvent system and an aqueous system are conceivable, but either can be used in the present invention. From the viewpoint of safety such as deterioration of the environment due to volatilization, hygiene and resource saving, water-based ones are preferable.

  Examples of the water-based easy-adhesive coating material include water-soluble or water-dispersible polyurethane and copolymer polyurethane resin, and the primer layer can be formed using these. Moreover, a primer layer can also be formed by bridge | crosslinking of acrylic resin and acrylic modified polyester resin which are described in Unexamined-Japanese-Patent No. 1-108037. Furthermore, a primer layer can also be formed using a styrene-butadiene resin or acrylonitrile-butadiene resin and a specific polyester resin described in JP-B-3-22899. Moreover, the styrene-butadiene-type copolymer and acrylic modified polyester resin which are described in Unexamined-Japanese-Patent No. 10-166517 can also be used.

The antireflection primer layer in the present invention can be made into an antistatic layer by mixing conductive metal oxide fine particles in a resin.
Examples of the conductive metal oxide fine particles include ATO (antimony-doped tin oxide), PTO (phosphorus-doped tin oxide), and ITO (tin-doped indium oxide). Examples of organic solvent-based transparent conductive paints containing these conductive metal oxide fine particles are described by Michio Komatsu, “Characteristics and Optimal Design / Film Production Technology of Antireflection Films”, Technical Information Association (2001), p. 37-39, and in the present invention, these coating materials can be used to form an antireflection primer layer. Further, the technique described in paragraph numbers 0040 to 0051 of JP-A-11-84573 can be applied.

When forming the primer layer in an organic solvent system, in order to increase the affinity between the inorganic fine particles and the organic component, it is preferable to treat the surface of the inorganic fine particles with a surface modifier containing an organic segment. Those having a high affinity for a functional group capable of forming a bond or adsorbing to inorganic fine particles and on the other hand a curable resin cured by irradiation with active energy rays are preferred.
Examples of the surface modifier having a functional group capable of binding or adsorbing to the inorganic fine particles include metal alkoxide curable resins such as silane, aluminum, titanium, and zirconium, and phosphoric acid groups, sulfuric acid groups, sulfonic acid groups, and carboxylic acid groups. A surface modifier having an anionic group is preferred. Furthermore, the functional group having a high affinity with the organic component may be simply a combination of the organic component and the hydrophilicity / hydrophobicity, but a functional group that can be chemically bonded to the organic component is preferable, and an ethylenically unsaturated group is particularly preferable. preferable.
In the present invention, the metal oxide fine particle surface modifier is preferably a metal alkoxide or an acrylic acid copolymer having an anionic group and an ethylenically unsaturated group in the same molecule and an anionic group such as a carboxylic acid. Etc.

Representative examples of these surface modifiers include the following unsaturated double bond-containing coupling agents, phosphate group-containing organic curable resins, sulfate group-containing organic curable resins, carboxylic acid group-containing organic curable resins, and the like. It is done.
S-1 H ₂ C═C (X) COOC ₃ H ₆ Si (OCH ₃ ) _{3
S-2 H 2 C = C} (X) COOC 2 H 4 OTi (OC 2 H 5) 3
S-3 H ₂ C═C (X) COOC ₂ H ₄ OCOC ₅ H ₁₀ OPO (OH) ₂
S-4 (H ₂ C═C (X) COOC ₂ H ₄ OCOC ₅ H ₁₀ O) ₂ POOH
S-5 H ₂ C═C (X) COOC ₂ H ₄ OSO ₃ H
S-6 H ₂ C═C (X) COO (C ₅ H ₁₀ COO) ₂ H
S-7 H ₂ C═C (X) COOC ₅ H ₁₀ COOH
(X represents H or CH ₃ )

The surface modification of these inorganic fine particles is preferably performed in a solution. When inorganic fine particles are mechanically finely dispersed, a surface modifier is present together, or after finely dispersing inorganic fine particles, the surface modifier is added and stirred, or further before finely dispersing inorganic fine particles Alternatively, the surface may be modified (if necessary, heated, dried and then heated, or changed in pH), and then finely dispersed.
As the solution for dissolving the surface modifier, an organic solvent having a large polarity is preferable. Specific examples include known solvents such as alcohols, ketones and esters.

  An overcoat layer having the same refractive index as that of the hard coat layer can be provided between the primer layer and the hard coat layer. Further, an undercoat layer having the same refractive index as that of the substrate can be provided between the primer layer and the substrate. Similarly, an overcoat layer having the same refractive index as that of the pressure-sensitive adhesive can be provided between the primer layer and the pressure-sensitive adhesive. Further, an undercoat layer having the same refractive index as that of the substrate can be provided between the primer layer and the substrate. In these cases, if the film thickness of the overcoat layer or the undercoat layer is large, the films are easily fixed to each other, and the light transmittance may be lowered. Therefore, the film thickness is preferably 1 μm or less. More preferably, it is 5 μm.

  The equipment used to apply the primer layer coating solution to the transparent substrate is a reverse coater, gravure coater, rod coater, air doctor coater, etc., published in Yuji Harasaki's “Coating Method” Shinsho Store, published in October 1979. In addition, any known coating apparatus can be used. From the standpoint of productivity, it is preferable to apply a roll-to-roll to a long plastic film. In this case, the length of the roll is preferably 10 m or more, more preferably 100 m or more, and particularly preferably 500 m or more. The width is preferably 30 cm or more, preferably 60 cm or more, and particularly preferably 1 m or more. Moreover, the thing which can apply a primer layer to front and back independently from a viewpoint of the freedom degree of prescription is preferable.

  The primer layer P of the present invention may be higher or lower than the refractive index of the substrate.

  If the primer layer is thick, the films are likely to stick to each other, and the light transmission may be reduced. In the present invention, interference of reflected light on both surfaces of the primer layer is used. However, the interference effect is reduced when the thickness is increased. For these reasons, the thickness of the primer layer is preferably 1 μm or less, and more preferably 0.5 μm or less.

(Hard coat layer)
The hard coat layer of the present invention is a layer that increases pencil hardness. As the hard coat film, by providing a hard coat layer, the pencil hardness of the hard coat side surface is preferably 2H or more, and more preferably 3H or more.

  The method for forming the hard coat layer of the present invention may be any method, but from the viewpoint of productivity, a curable composition that is cured by irradiation with active energy rays is applied, and curing that is cured by irradiation with the active energy rays is performed. A layer made of a conductive resin is preferable.

  The curable resin that is cured by irradiation with active energy rays is preferably a curable resin having two or more acrylic groups in the same molecule. Specific examples include ethylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol-A diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipenta. Polyfunctional urethane acrylates and polyepoxy curable resins obtained by reaction of polyol polyacrylates such as erythritol pentaacrylate and dipentaerythritol hexaacrylate, and polyisocyanate curable resins and hydroxyl-containing acrylates such as hydroxyethyl acrylate and hydroxyethyl acrylate Polyfunctionality obtained by reaction of hydroxyl group-containing acrylate (methacrylate) It can be exemplified port carboxymethyl acrylate. A polymer having an ethylenically unsaturated group in the side chain can also be used.

  In the present invention, for curing the hard coat layer, radiation, gamma rays, alpha rays, electron beams, ultraviolet rays and the like are used as active energy rays. Among these methods, a method of adding a polymerization initiator that generates radicals using ultraviolet rays and curing with ultraviolet rays is particularly preferable.

  The polymerization initiators may be used alone or in combination with a plurality of initiators. The addition amount of the polymerization initiator is 0.1 to 15% by mass with respect to the total mass of the ethylenically unsaturated group-containing curable resin and the ring-opening polymerizable group-containing curable resin contained in the curable composition. It is preferably used in a range, and more preferably in a range of 1 to 10% by mass.

The hard coat film or antireflection film of the present invention is a film having very little or no surface unevenness and almost no surface haze, and when haze is imparted, it has internal haze, that is, has internal scattering properties. preferable.
As described above, interference spots are generated by interference between reflected light at the hard coat layer / substrate film interface and reflected light at the hard coat layer surface (antireflection layer surface). In the case of having, the surface reflected light is scattered and interference is difficult to occur. Therefore, the present invention is effective in a system with little scattering due to irregularities on the surface of the hard coat layer.

  For the above reason, the center line average roughness Ra of the hard coat layer surface is preferably 0.1 μm or less, more preferably 0.08 μm or less, and particularly preferably 0.05 μm or less. For the same reason, the surface haze of the hard coat layer of the present invention is preferably 5% or less, more preferably 3% or less, and particularly preferably 1% or less.

  Japanese Patent No. 3507719 discloses a technique relating to a film that improves the viewing angle dependency of the LCD by having only internal scattering and no surface scattering. However, the present invention may be applied to such a film. This is a preferred embodiment.

(High refractive index hard coat layer)
When a high refractive index film such as PET is used as the plastic film substrate, it is necessary to increase the refractive index of the hard coat layer.
The refractive index of the hard coat layer in the present invention can be increased by mixing metal oxide fine particles with a resin.
The metal oxide fine particles include titanium dioxide (eg, rutile, rutile / anatase mixed crystal, anatase, amorphous structure), tin oxide, indium oxide, zinc oxide, zirconium oxide having an average particle size of 100 nm or less, preferably 50 nm or less. Examples thereof include particles and aluminum oxide particles having a refractive index of greater than 1.6. Titanium dioxide having a large refractive index is preferable because the refractive index of the hard coat layer can be adjusted with a small addition amount.

As an example of the composition for forming the high refractive index hard coat layer, a resin-forming component of the hard coat layer is a polyfunctional acrylate monomer, and a powdery inorganic filler such as alumina or titanium oxide is added thereto. A coating composition is disclosed in Japanese Patent No. 1815116. Japanese Patent No. 1416240 describes a photopolymerizable composition containing an inorganic charge material made of alumina.
It is also widely known that a conductive material is mixed in the hard coat layer to impart antistatic properties. When ATO (antimony-doped tin oxide), PTO (phosphorus-doped tin oxide) or ITO (tin-doped indium oxide) is used as the metal oxide fine particles, conductivity can be imparted. These conductive metal oxide fine particles also have a high refractive index and cause the same problems as described above. Examples of organic solvent-based transparent conductive paints are described by Michio Komatsu, “Characteristics and Optimal Design / Film Production Technology of Antireflection Films”, Technical Information Association (2001), p. 37-39.

  Another method for forming a hard coat layer having a high refractive index is a method using a polymer having a high refractive index as a binder. Of course, a combination of a high refractive index binder and high refractive index fine particles is also possible. The polymer having a high refractive index used as the binder of the hard coat layer is preferably a polymer having a cyclic group or a polymer containing a halogen atom other than fluorine. A polymer having a cyclic group is preferred to a polymer containing a halogen atom other than fluorine. A polymer containing both a cyclic group and a halogen atom other than fluorine may be used. The cyclic group includes an aromatic group, a heterocyclic group and an aliphatic ring group. Aromatic ring groups are particularly preferred. As a halogen atom other than fluorine, a chlorine atom is preferable.

(Low refractive index hard coat layer)
When a low refractive index film such as TAC is used as the plastic film substrate, it is necessary to lower the refractive index of the hard coat layer.
The refractive index of the hard coat layer in the present invention can be lowered by mixing silica fine particles with a resin.
The silica fine particles preferably have an average particle size of 100 nm or less, more preferably 50 nm or less, and particularly preferably 30 nm or less.

  In addition, hollow silica fine particles with pores inside have been developed in recent years as silica fine particles with a high refractive index reducing effect (for example, Michio Komatsu, “Characteristics and Optimal Design of Antireflective Films / Film Production Technology”, Technology Information Association (2001), p. 49) In the hard coat layer of the present invention, the refractive index can be controlled using such hollow particles.

  The film thickness of the hard coat layer is not particularly limited, but when it exceeds 10 μm, the interference spots become thinner due to the coherent length described above, and when it is 20 μm or more, it is easy to completely eliminate the interference spots when combined with the primer layer of the present invention. Become. Therefore, in this respect, it is also a preferable aspect that the hard coat film thickness is 10 μm or more.

The hard coat layer of the present invention is produced by dipping the active energy ray curable coating solution on a transparent substrate, spinner method, spray method, roll coater method, gravure method, wire bar method, slot extrusion coater method (single layer) , Multi-layered), and a known thin film forming method such as a slide coater method, followed by drying, irradiation with active energy rays, and curing.
Drying is preferably performed under conditions where the organic solvent concentration in the applied liquid film is 5% by mass or less after drying, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The drying conditions are affected by the thermal strength of the substrate, the conveyance speed, the length of the drying process, and the like, but the one having as low an organic solvent content as possible is preferable in terms of increasing the polymerization rate.

  The hard coat layer can have a multi-layer structure, and can be produced by appropriately laminating in order of hardness.

(Antireflection layer)
In the present invention, in order to prevent reflection from the surface of the hard coat layer on these prepared hard coat layers, an antireflection layer excellent in scratch resistance comprising a low refractive index layer and a high refractive index layer is provided. By providing, it can be set as the anti-reflective hard coat layer of high surface hardness.
Since the hard coat layer of the present invention using a high refractive index transparent plastic film substrate such as PET has a high refractive index, even one low refractive index layer can effectively reduce the reflectance. This is a preferred embodiment of the present invention.

In the present invention, the low refractive index layer and the high refractive index layer are mainly composed of a curable resin that is cured by irradiation with active energy rays, or the low refractive index layer and the high refractive index layer are cured by irradiation with active energy rays. The layer is preferably composed of a conductive resin and metal oxide fine particles.
The curable resin that is cured by irradiation with active energy rays is preferably a curable resin having two or more acrylic groups in the same molecule. Specific examples include ethylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol-A diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipenta. Polyfunctional urethane acrylates and polyepoxy curable resins obtained by reaction of polyol polyacrylates such as erythritol pentaacrylate and dipentaerythritol hexaacrylate, and polyisocyanate curable resins and hydroxyl-containing acrylates such as hydroxyethyl acrylate and hydroxyethyl acrylate Polyfunctionality obtained by reaction of hydroxyl group-containing acrylate (methacrylate) It can be exemplified port carboxymethyl acrylate. A polymer having an ethylenically unsaturated group in the side chain can also be used.

  As the metal oxide fine particles, titanium dioxide having an average particle size of 100 nm or less, preferably 50 nm or less (eg, rutile, rutile / anatase mixed crystal, anatase, amorphous structure), tin oxide, indium oxide, zinc oxide, zirconium oxide Examples thereof include particles and aluminum oxide particles having a refractive index of greater than 1.6. Titanium dioxide having a large refractive index is preferred because the amount added can be reduced.

In order to increase the affinity between the inorganic fine particles and the organic component, the surface of the inorganic fine particles is preferably treated with a surface modifier containing an organic segment, and the surface modifier can form a bond with the inorganic fine particles or be adsorbed on the inorganic fine particles. Those having a high affinity for the functional group and, on the other hand, a curable resin that is cured by irradiation with active energy rays are preferred.
Examples of the surface modifier having a functional group capable of binding or adsorbing to inorganic fine particles include metal alkoxide curable resins such as silane, aluminum, titanium and zirconium, and phosphoric acid groups, phosphonic acid groups, sulfuric acid groups, sulfonic acid groups, carboxylic acids. A surface modifier having an anionic group such as an acid group is preferred. Furthermore, the functional group having a high affinity with the organic component may be simply a combination of the organic component and the hydrophilicity / hydrophobicity, but a functional group that can be chemically bonded to the organic component is preferable, and an ethylenically unsaturated group is particularly preferable. preferable.
In the present invention, the metal oxide fine particle surface modifier is preferably a metal alkoxide or an acrylic acid copolymer having an anionic group and an ethylenically unsaturated group in the same molecule and an anionic group such as a carboxylic acid. Etc.

Representative examples of these surface modifiers include the following unsaturated double bond-containing coupling agents, phosphate group-containing organic curable resins, sulfate group-containing organic curable resins, carboxylic acid group-containing organic curable resins, and the like. It is done.
S-1 H ₂ C═C (X) COOC ₃ H ₆ Si (OCH ₃ ) _{3
S-2 H 2 C = C} (X) COOC 2 H 4 OTi (OC 2 H 5) 3
S-3 H ₂ C═C (X) COOC ₂ H ₄ OCOC ₅ H ₁₀ OPO (OH) ₂
S-4 (H ₂ C═C (X) COOC ₂ H ₄ OCOC ₅ H ₁₀ O) ₂ POOH
S-5 H ₂ C═C (X) COOC ₂ H ₄ OSO ₃ H
S-6 H ₂ C═C (X) COO (C ₅ H ₁₀ COO) ₂ H
S-7 H ₂ C═C (X) COOC ₅ H ₁₀ COOH
(X represents H or CH ₃ )

The surface modification of these inorganic fine particles is preferably performed in a solution. When inorganic fine particles are mechanically finely dispersed, a surface modifier is present together, or after finely dispersing inorganic fine particles, the surface modifier is added and stirred, or further before finely dispersing inorganic fine particles Alternatively, the surface may be modified (if necessary, heated, dried and then heated, or changed in pH), and then finely dispersed.
As the solution for dissolving the surface modifier, an organic solvent having a large polarity is preferable. Specific examples include known solvents such as alcohols, ketones and esters.

  In the present invention, radiation, gamma rays, alpha rays, electron beams, ultraviolet rays, and the like are used as active energy rays for curing the high refractive index layer. Among these methods, a method of adding a polymerization initiator that generates radicals using ultraviolet rays and curing with ultraviolet rays is particularly preferable.

  Examples of polymerization initiators that generate radicals by ultraviolet rays include known radical generators such as acetophenones, benzophenones, Michler's ketone, benzoylbenzoate, benzoins, α-acyloxime esters, tetramethylthiuram monosulfide, and thioxanthone. Can be used. Further, as mentioned above, since sulfonium salts and iodonium salts that are usually used as photoacid generators also act as radical generators upon irradiation with ultraviolet rays, these may be used alone in the present invention. In addition to a polymerization initiator, a sensitizer may be used for the purpose of increasing sensitivity. Examples of the sensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone derivatives.

  The polymerization initiators may be used alone or in combination with a plurality of initiators. The addition amount of the polymerization initiator is 0.1 to 15% by mass with respect to the total mass of the ethylenically unsaturated group-containing curable resin and the ring-opening polymerizable group-containing curable resin contained in the curable composition. It is preferably used in a range, and more preferably in a range of 1 to 10% by mass.

  The refractive index of the high refractive index layer comprising a curable resin and metal oxide fine particles that are cured by irradiation with these active energy rays is preferably 1.6 or more, more preferably 1.65 or more, and more than the refractive index of the low refractive index layer. It is preferably 0.2 or more.

For the low refractive index layer, a curable resin similar to the curable resin that is cured by irradiation with active energy rays used for the high refractive index layer can be used. The refractive index after curing of the resin used is preferably 1.6 or less, and the metal oxide fine particles are preferably silicon dioxide having a small refractive index.
The refractive index of the low refractive index layer is preferably 1.45 or more and 1.6 or less, and more preferably 1.55 or less.

These high refractive index layer and low refractive index layer are each applied in the range of 50 to 100 nm, and the optical distance (refractive index × thickness) is 4 minutes of the observation wavelength (especially 580 nm) in order to increase the antireflection effect. 1 is preferable.
In the present invention, the high refractive index layer and the low refractive index layer are obtained by applying the active energy ray-curable coating liquid on the hard coat layer, the spinner method, the gravure method, and the wire bar method in the order of the high refractive index layer and the low refractive index layer. It can be produced by applying a known thin film forming method such as drying, irradiating with active energy rays and curing.

  The reflectance (regular reflectance) of the antireflection layer is preferably 3.0% or less, and more preferably 1.5% or less. The reduction in reflectivity between the transparent plastic film substrate / hard coat layer according to the present invention is more important for an antireflection film having a lower reflectivity.

  Moreover, the wavelength which becomes interference spots can be effectively prevented by making the minimum wavelength of the reflectance close to 546 nm where the emission line spectral components of the three-wavelength fluorescent lamp are concentrated, which is preferable. Specifically, the minimum value Rmin of the reflectance is preferably 520 nm to 570 nm, more preferably 536 to 556 nm, and particularly preferably 540 nm to 550 nm.

In the antireflection hard coat layer of the present invention, in order to improve the antifouling property of the antireflection layer, a curable resin containing fluorine and / or silicon is contained in the low refractive index layer, or on the low refractive index layer. A layer containing a curable resin containing fluorine and / or silicon can also be provided.
Examples of the curable resin to be added to the low refractive index layer include known fluorine curable resins and silicon curable resins, or curable resins having a block having fluorine and silicon-containing portions, and further resins, metal oxides, etc. A curable resin having a segment having good compatibility with fluorine and a segment containing fluorine or silicon is preferable. By adding to the low refractive index layer, fluorine or silicon can be unevenly distributed on the surface.

  Specific examples of these curable resins include block copolymers or graft copolymers of fluorine- or silicon-containing monomers with other hydrophilic or lipophilic monomers. Examples of the fluorine-containing monomer include perfluoroalkyl group-containing (meth) acrylic esters represented by hexafluoroisopropyl acrylate, heptadecafluorodecyl acrylate, perfluoroalkylsulfonamidoethyl acrylate, perfluoroalkylamidoethyl acrylate, and the like. Examples of the silicon-containing monomer include monomers having a siloxane group by reaction of polydimethylsiloxane and (meth) acrylic acid. Hydrophilic or lipophilic monomers include (meth) acrylic acid esters such as methyl acrylate, hydroxyl-containing polyester and (meth) acrylic acid ester at the terminal, hydroxyethyl (meth) acrylate, polyethylene glycol (meth) acrylic acid Examples include esters. Commercially available curable resins include acrylic oligomer defensers MCF-300, 312, 323, etc. having a perfluoroalkyl chain microdomain structure, and perfluoroalkyl group / lipophilic group-containing oligomers Megafac F-170, F -173, F-175, etc., perfluoroalkyl group / hydrophilic group-containing oligomer Megafac F-171 (Dainippon Ink Chemical Co., Ltd.), and segments with excellent surface migration and resin are compatible. Examples thereof include alkyl fluoride-based Modiper F-200, 220, 600, and 820 which are block polymers of vinyl monomers composed of segments, and silicon-based Modiper FS-700 and 710 (manufactured by NOF Corporation).

  In order to provide an antifouling layer on the low refractive index layer, a curable resin having a low surface energy and containing fluorine atoms is preferable. Specifically, JP-A-57-34526 and JP-A-2 Examples include fluorinated hydrocarbon group-containing silicon curable resins and fluorinated hydrocarbon group-containing polymers described in JP-A No. 19801 and JP-A-3-170901.

  In addition to the antireflection layer, the plastic film of the present invention can be laminated together with layers having functions such as an ultraviolet / infrared absorbing layer, a colored layer, a selective wavelength absorbing layer, an electromagnetic wave shielding layer, and the like. Served as a functional film of hardness.

  Moreover, as an image display apparatus provided with the plastic film of this invention, displays, such as CRT, LCD, FED, EL, a touch panel, a display board of a portable game, etc. are preferable. In particular, a flat CRT television that requires the base material to be PET from the viewpoint of preventing crushing and a PDP in which a part of the base material is made of PET are preferable.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to an Example.

<Preliminary experiment>
The relationship between the refractive index difference (| n _S −n _H |) between the substrate and the hard coat layer and the occurrence of interference spots was examined in the following experiment.

(Hard coat layer coating solution)
Titanium dioxide fine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.) 30.0 parts by mass, carboxylic acid group-containing monomer (Aronix M-5300 manufactured by Toagosei Co., Ltd.) 4.5 parts by mass and cyclohexanone 65.5 parts by mass Was dispersed by a sand grinder mill to prepare a titanium dioxide dispersion having a mass average diameter of 55 nm. A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) and a photo radical polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals, Inc., monomer) (5% with respect to the total amount of dipentaerythritol hexaacrylate, anionic monomer and cationic monomer) and the refractive index was adjusted to be in Table 1.

(Application of hard coat layer)
Both sides of 100 μm thick PET (biaxially stretched polyethylene terephthalate film having a refractive index of 1.65 in the plane direction) were subjected to corona treatment, and the coating solution was applied on one side so that the film thickness after drying was 5 μm.

Here, the interference spots were evaluated by the following method.
Evaluation of interference spots: Place a sample with rubbing on the back side with sandpaper and applying black magic so that reflection on the back side does not occur on the desk, and a three-wavelength fluorescent lamp (National PALUCK fluorescent lamp FL20SS · EX-D) from 30 cm above The sample was illuminated with / 18), interference spots were observed, and evaluated according to the following criteria.
◎: Interference spots are not visible at all. ○: Interference spots are hardly visible. △: Interference spots appear weak. ×: Interference spots appear strong. XX: Interference spots appear very strong.

  From the above results, it was found that when the refractive index difference between the base material and the hard coat layer was 0.03, interference spots started to appear, the refractive index difference increased, and the interference spots looked strong.

<Example>
(Production of PET base with primer layer 1- Examples 1 to 5, Comparative Examples 1 and 2)
(A) Formation of primer layer (no conductive metal oxide): Examples 1 to 3, Comparative Examples 1 and 2
Latex made of polyester resin having a refractive index of 1.53 and a glass transition temperature of 55 ° C. (Pesresin A-520, Takamatsu) on both sides of PET (biaxially stretched polyethylene terephthalate film, refractive index 1.65) having a thickness of 100 μm. Apply the water-based primer layer coating solution (p-1) made of Yushi Co., Ltd. on one side so that the film thickness after drying is the value shown in Table 2 (178 nm, 356 nm, 534 nm, 98 nm, 264 nm). A primer layer was formed.
(B) Formation of primer layer containing conductive metal oxide: Examples 4 and 5
Latex made of polyester resin having a refractive index of 1.53 and a glass transition temperature of 55 ° C. (Pesresin A-520, Takamatsu) on both sides of PET (biaxially stretched polyethylene terephthalate film, refractive index 1.65) having a thickness of 100 μm. (F-Co., Ltd.) and tin oxide / antimony oxide composite oxide (SN-38, manufactured by Ishihara Sangyo Co., Ltd.) were mixed so that the refractive index after drying was 1.59 (p- 2) was prepared and applied to one side so that the film thickness after drying was a value shown in Table 2 (172 nm, 160 nm) to form a primer layer.

(Preparation of PET base with primer layer 2-Example 6)
(1) Preparation of organic solvent-based primer layer coating solution (p-3) 30.0 parts by mass of titanium dioxide fine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.), carboxylic acid group-containing monomer (Aronix M-5300 Toagosei) 4.5 parts by mass and 65.5 parts by mass of cyclohexanone were dispersed by a sand grinder mill to prepare a titanium dioxide dispersion having a mass average diameter of 55 nm. A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) and a photo radical polymerization initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals, Inc., monomer) (5% with respect to the total amount of dipentaerythritol hexaacrylate, anionic monomer and cationic monomer) was mixed to adjust the refractive index of the primer layer to 1.59.
(2) Production of base Corona treatment is performed on both sides of 100 μm thick PET (biaxially stretched polyethylene terephthalate film, refractive index: 1.65) so that the coating film (p-3) has a thickness of 172 nm after drying. Applied to one side.

(Preparation of TAC base with primer layer-Example 7, Comparative Example 3)
(1) Preparation of organic solvent-based primer layer coating solution (p-4) Commercially available transparent antistatic layer coating “Pertron C-4456S-7” (solid content 45%, manufactured by Nippon Pernox Co., Ltd.) Used as an antistatic primer layer coating liquid (p-4). C-4456S-7 is a coating for transparent antistatic layer containing conductive fine particles ATO dispersed using a dispersion. The refractive index of the film thickness by this paint was 1.55.
(2) Preparation of base After drying the coating liquid (p-4) on an 80 μm-thick TAC film (triacetyl cellulose film (TAC-TD80U, manufactured by Fuji Photo Film Co., Ltd.), refractive index 1.48) The film was coated on one side so that the film thickness would be the values shown in Table 2 (176 nm, 264 nm).

(Preparation of PC base with primer layer-Example 8)
(1) Preparation of organic solvent based primer layer coating solution (p-5) 450 parts by weight of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) It was dissolved in a mixed solvent of isopropyl alcohol (IPA) and 140 parts by weight of methyl isobutyl ketone (MIBK). To the resulting solution, 12.0 parts by weight of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) was added and stirred until dissolved, then 380 parts by weight of IPA-ST (average particle size of 10 to 10). 20 nm, isopropyl alcohol dispersion of SiO ₂ sol having a solid content of 30% by weight, manufactured by Nissan Chemical Co., Ltd., and 257 parts by weight of MIBK-ST (average particle size of 10-20 nm, solid content of 30% by weight of SiO ₂ A sol methyl isobutyl ethyl ketone dispersion (manufactured by Nissan Chemical Co., Ltd.) was added and stirred to obtain a mixture, which was filtered through a polypropylene filter (PPE-03) having a pore size of 3 μm, and a primer layer coating solution (p- 5) was prepared.
(2) Preparation of base To dry the primer layer coating solution (p-5) on the air surface of a polycarbonate film having a thickness of 80 mm (Pure Ace 110-80 manufactured by Teijin Chemicals Ltd.), the thickness after drying is 184 nm. After applying using a bar coater and drying at 70 ° C. for 1 minute, the primer layer was cured by irradiating with ultraviolet rays to prepare a PC film with a primer layer.

(Preparation of hard coat layer coating solution (h-1))
306 parts by weight of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was dissolved in a mixed solvent of 16 parts by weight of methyl ethyl ketone and 220 parts by weight of cyclohexanone. After adding 7.5 parts by weight of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) to the obtained solution and stirring until dissolved, 450 parts by weight of MEK-ST (average particle size of 10 to 10) was added. 20 nm, solid content concentration 30 wt% SiO ₂ sol methyl ethyl ketone dispersion (Nissan Chemical Co., Ltd.) was added and stirred to obtain a mixture, which was filtered through a polypropylene filter (PPE-03) with a pore size of 3 μm. A hard coat layer coating solution (h-1) was prepared. The refractive index after curing was adjusted to 1.48.

(Preparation of hard coat layer coating solution (h-2))
Titanium dioxide fine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.) 30.0 parts by mass, carboxylic acid group-containing monomer (Aronix M-5300 manufactured by Toagosei Co., Ltd.) 4.5 parts by mass and cyclohexanone 65.5 parts by mass Was dispersed by a sand grinder mill to prepare a titanium dioxide dispersion having a mass average diameter of 55 nm. The titanium dioxide dispersion was mixed with dipentaerythritol hexaacrylate, 5% based on the total amount of the anionic monomer and the cationic monomer) to prepare a refractive index after curing of 1.65.

(Preparation of hard coat layer coating solution (h-3))
Titanium dioxide fine particles (TTO-55B, manufactured by Ishihara Sangyo Co., Ltd.) 30.0 parts by mass, carboxylic acid group-containing monomer (Aronix M-5300 manufactured by Toagosei Co., Ltd.) 4.5 parts by mass and cyclohexanone 65.5 parts by mass Was dispersed by a sand grinder mill to prepare a titanium dioxide dispersion having a mass average diameter of 55 nm. The titanium dioxide dispersion was mixed with dipentaerythritol hexaacrylate, 5% based on the total amount of the anionic monomer and the cationic monomer) to prepare a refractive index after curing of 1.60.

(Preparation of hard coat film)
On the primer layer P of the film with the primer layer produced above, the hard coat layer coating solution is applied by an extrusion method so as to have the thickness (5 μm) shown in Table 2, dried, and irradiated with ultraviolet rays (700 mJ / Cm ² ) to harden the hard coat layer to produce a hard coat film. (See Figure 1)

  The interference spots were evaluated by the same method as in the preliminary experiment.

From the results shown in Table 2, the following is clear.
When the substrate is a PET film, the hard coat layer of the present invention has a specific film thickness of the primer layer between the PET film substrate / hard coat layer after adjusting the refractive index of the hard coat layer to the refractive index of the substrate. In the films (Examples 1 to 6), no interference spots were seen under a three-wavelength fluorescent lamp, but interference spots were strongly observed in the films (Comparative Examples 1 and 2) in which the film thickness of the primer layer was not controlled to a specific value. .
Even if the base material is a TAC film (Example 7, Comparative Example 3), the film thickness of the primer layer between the PET film base material / hard coat layer is specified after adjusting the refractive index of the hard coat layer to the refractive index of the base material. The hard coat film of the present invention having a film thickness (Example 7) does not show interference spots under a three-wavelength fluorescent lamp, but the film thickness of the primer layer is not controlled to a specific value (Comparative Example 3). Was strongly observed.
The same result was obtained when the substrate was a PC film (Example 8).

[Application of hard coat film to antireflection film]
(Preparation of single-layer antireflection layer)
(1) Preparation of low refractive index layer coating solution (Ln-1) 6% by mass of methyl isobutyl ketone solution (JN-7228, manufactured by JSR Corporation) having a refractive index of 1.42 and a thermally crosslinkable fluorine-containing polymer. Was replaced with a solvent to obtain a polymer solution containing 10% by mass of solid content in a mixed solvent consisting of 85% by mass of methyl isobutyl ketone and 15% by mass of 2-butanol. In 70 parts by mass of this polymer solution, 10 parts by mass of MEK-ST (Methyl ethyl ketone dispersion of SiO 2 sol having an average particle size of 10 to 20 nm and a solid content concentration of 30% by mass, manufactured by Nissan Chemical Co., Ltd.), and 42 parts by mass of methyl isobutyl ketone Then, 28 parts by mass of cyclohexanone was added, stirred, and then filtered through a polypropylene filter (PPE-03) having a pore size of 3 μm to prepare a low refractive index layer coating solution (Ln-1).
(2) Production of hard coat film with single-layer antireflection layer On the hard coat layer of the hard coat film produced in Example 4, the low refractive index layer coating solution (Ln-1) was applied using a gravure coater. The coating layer was applied and cured at 120 ° C. for 8 minutes, and a low refractive index layer (refractive index 1.43, film thickness 96 nm) was provided according to Table 3. In this way, an antireflection film was produced. (See Figure 2)

The surface reflectance shown in Table 3 was measured as follows.
Measurement of surface reflectance; rubbing the back surface with sandpaper, applying black magic so that the back surface reflection does not occur, and using a spectrophotometer (manufactured by JASCO Corporation), 450-650 nm The average reflectance and the minimum reflectance wavelength of the surface reflectance of regular reflection at an incident light of 5 ° in the wavelength region were obtained.
Evaluation of interference spots: Evaluation was performed in the same manner as in the preliminary experiment.

From the results shown in Table 3, the following is clear.
By providing the primer layer of the present invention, an antireflection film has an effect of preventing interference spots. In addition, the average reflectance is also lowered.

[Production of hard coat film-laminated glass plate with double-sided antireflection layer]
A primer layer coating solution (p-2) is applied to the surface of Example 11 where the hard coat layer of the PET film substrate is not laminated, and the cured film thickness is 86 nm and the refractive index is 1.59. Next, an acrylic pressure-sensitive adhesive having a thickness of 20 μm and a refractive index of 1.52 was laminated to prepare a hard coat film with an antireflection layer with a pressure-sensitive adhesive layer (Example 21). (See Figure 6)
The film of Example 21 and the film (Comparative Example 21) in which an acrylic adhesive having a thickness of 20 μm and a refractive index of 1.52 was laminated on the surface of the base material of Comparative Example 11 on which the antireflection layer was not laminated, respectively. The pressure-sensitive adhesive layer surface was bonded to the front and back surfaces of a 3 mm (thickness) glass plate according to Table 5 (S-1, S-2). Table 4 shows the measurement of the reflectance performed on the glass plate and the result of interference spots.

  The average integrated reflectance shown in Table 4 was measured by the method of JIS-R-3106. The interference spots were evaluated by the same method as in the preliminary experiment.

From the results shown in Table 4, the following is clear.
The hard coat film-laminated glass plate with a double-sided antireflection layer (S-1) provided with an antireflection film with an optimized thickness of the primer layer of the present invention has a low average integrated reflectance and no interference spots. When an antireflection film in which the thickness of the primer layer is not optimized is provided (S-2), the reflectance is high and interference spots appear very strong.

[Application of antireflection film to PDP front panel]
The antireflection hard coat film of Example 21 and Comparative Example 21 were peeled off from the front plate surface of the plasma display (PDP-433HD-U Pioneer Co., Ltd.) and partially cut into 10 cm × 10 cm at the center. Adhering the anti-reflection hard coat film next to each other so that each anti-reflection layer is the outermost surface, and using a three-wavelength fluorescent lamp (National Parook fluorescent lamp FL40SS · EX-D / 37) as room lighting Observed at. The display with the antireflection hard coat film of Example 21 had no interference spots and the visibility was good, whereas the display with the antireflection hard coat film of Comparative Example 21 showed strong interference spots. . From this result, it was found that the antireflection hard coat film obtained by the present invention is suitable for a PDP front plate as an image display device.

The plastic film of the present invention comprising a transparent plastic film substrate, a primer layer P, and a functional layer (hard coat layer). The plastic film of the present invention comprising a transparent plastic film substrate, a primer layer P, a functional layer (hard coat layer), and an antireflection layer (low refractive index single layer constitution). The plastic film of the present invention comprising a transparent plastic film substrate, a primer layer P, a functional layer (hard coat layer), and an antireflection layer (a high refractive index layer and a low refractive index two-layer structure). The plastic film of the present invention comprising a transparent plastic film substrate, a primer layer P, and a functional layer (adhesive layer). The plastic film of the present invention comprising a functional layer (hard coat layer), a primer layer P, a transparent plastic film substrate, a primer layer Q, and a functional layer (adhesive layer). The plastic film of the present invention comprising an antireflection layer, a functional layer (hard coat layer), a primer layer P, a transparent plastic film substrate, a primer layer Q, and a functional layer (adhesive layer).

Explanation of symbols

A Transparent plastic film B Primer layer P
C Functional layer (hard coat layer)
D Antireflection layer E High refractive index layer F Low refractive index layer G Primer layer Q
H Functional layer (adhesive layer)

Claims (10)

A plastic film in which at least one surface of a transparent plastic film base material is laminated with a primer layer having a thickness of 1 μm or less and a functional layer having a thickness of 1 μm or more in this order,
The transparent plastic film substrate and the functional layer have substantially no difference in refractive index at a wavelength of 546 nm,
And the refractive index of the transparent plastic film substrate and the primer layer are substantially different at a wavelength of 546 nm,
Plastic film thickness d _P of the primer layer is characterized by satisfying the following formula (1).
Formula (1)
d _P = (N × 546 ± 50) / (2n _P ) (nm)
However, n _P is the refractive index of the primer layer, N is a natural number. Plastic film according to claim 1 having a thickness d _P of the primer layer is characterized by satisfying the following equation (2).
Formula (2)
d _P = (N × 546 ± 25) / (2n _P ) (nm)   3. The plastic film according to claim 1, wherein N is 1 or 2.   The hard coat film according to claim 1, wherein the functional layer is a hard coat layer.   The plastic film according to claim 1, wherein the functional layer is an adhesive layer. A plastic film in which another primer layer and an adhesive layer are laminated in this order on the surface of the transparent plastic film substrate on which the primer layer is not laminated,
The transparent plastic film substrate and the adhesive layer have substantially different refractive indices at a wavelength of 546 nm,
Plastic film according to claim 1, the refractive index n _Q and the thickness d _Q of said another primer layer is characterized by satisfying the following formula (3) and Equation (4).
Formula (3)
n _Q = (n _S × n _A ) ^1/2 ± | n _S × n _A | / 4
However, n _S is the refractive index of the substrate, the n _A is the refractive index of the adhesive layer.
Formula (4)
d _Q = (M × 546 ± 50) / (4n _Q ) (nm)
However, M is a natural number.   The plastic film according to claim 6, wherein at least one of the primer layers contains conductive metal oxide fine particles and has antistatic properties.   8. The plastic film according to claim 4, further comprising another functional layer on the surface of the hard coat layer opposite to the transparent plastic film substrate. 9.   9. The plastic film according to claim 8, wherein the another functional layer is an antireflection layer.   An image display device comprising the plastic film according to claim 1.

Images