JP2000263702A - Hard coat film, production thereof and hard coat film laminated cathode ray tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard coat film using a plastic substrate film, having surface scratch resistance and having strength sufficient to show scattering preventing effect. SOLUTION: In a hard coat film including a transparent substrate film 2, the hard coat layer 1 provided in one surface of the transparent substrate film 2 and the self-adhesive layer 3 provided on the other surface of the substrate film 2, the transparent substrate film 2 is formed by laminating a first transparent substrate film 4, and adhesive layer 5 and a second transparent substrate film 6 and the elastic modulus of the second transparent substrate film 6 is made lower than that of the first transparent substrate film 4 to achieve strength sufficient to show scattering preventing effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hard coat film having a hard coat layer on a transparent substrate film. More specifically, the present invention relates to a hard coat film having excellent scratch resistance and excellent strength, and a method for producing the same. Furthermore, the present invention relates to a cathode ray tube having a hard coat film bonded thereto. The hard coat film of the present invention,
It is suitable for a surface protective film on the surface of a display such as a CRT, LCD, or PDP, and is particularly suitable for a surface protective film of a CRT display.

[0002]

2. Description of the Related Art In recent years, plastic products have been replaced with glass products from the viewpoint of workability and weight reduction. However, since the surface of these plastic products is easily damaged, a hard coat film is applied for the purpose of imparting scratch resistance. Often used together. Also, for conventional glass products,
In many cases, a plastic film is bonded to prevent scattering, but due to insufficient hardness, a hard coat is widely formed on the surface thereof. CRT and LC
In displays such as D, a hard coat film is suitably used to protect the surface of the display screen of the display.

A hard coat film is disclosed in, for example,
As shown in JP-A-2-87352, an ionizing radiation-curable resin such as a thermosetting resin or an ultraviolet-curable resin is used.
Directly on a plastic substrate film having a thickness of about 0 to 188 μm or via a primer layer of about 1 μm
A thin hard coat layer of about 15 μm is formed, and an adhesive or an ultraviolet curable adhesive is applied to the surface of the plastic substrate film opposite to the surface on which the hard coat layer is formed. Usually, it is used by laminating it.

In CRT display applications, CRT
Is a highly evacuated glass vacuum tube. If a part of the CRT is damaged by various external forces or sudden temperature changes, the atmospheric pressure will cause the debris to suddenly jump into the inside of the CRT, This may cause the debris to fly outward (so-called implosion), and as a result, there is a risk of injuries to those around (especially the front). So CR
It is required to protect the face plate of T to prevent damage and to prevent the fragments from being scattered in case of breakage.

In CRT display applications,
In order to improve the contrast, it is also required to adjust the visible light transmittance of the hard coat film to about 40 to 80%, and any one of the layers constituting the hard coat film is colored, or It has been practiced to provide a colored layer between any of the layers constituting the hard coat film.

[0006]

However, although the conventional hard coat film has abrasion resistance on the surface, the hard coat film in the entire hard coat film has a sufficient scattering prevention effect when the CRT is broken. There was a problem that it did not have strength.

Further, in order to adjust the visible light transmittance of the hard coat film, one of the layers constituting the hard coat film is colored, or the other one of the layers constituting the hard coat film is colored. Providing a colored layer between such layers has the problem that the number of manufacturing steps is increased and the scratch resistance of the hard coat film is reduced.

The present invention solves the above-mentioned problems in a hard coat film using a transparent substrate film, and has such a strength that the hard coat film has surface scratch resistance and sufficiently exhibits a scattering prevention effect. An object of the present invention is to provide a hard coat film having:

[0009]

The present invention provides a transparent base film, a hard coat layer provided on at least one surface of the transparent base film, and a transparent base film. A hard coat film including an adhesive layer provided on the other surface, wherein the transparent base film is formed by laminating a first transparent base film, an adhesive layer, and a second transparent base film. Thereby, the above object is achieved.

According to the present invention, the first transparent base film has an elastic modulus of 200 to 1000 kgf / mm.
² , and the elastic modulus of the second transparent base film is
The above object is achieved by a hard coat film having a lower elastic modulus than the first transparent base film.

According to a third aspect of the present invention, the adhesive layer and / or the adhesive layer may be a hard coat film containing a coloring agent.

Further, the second transparent substrate film may be a hard coat film containing a coloring agent.

According to a fifth aspect of the present invention, a hard coat film containing an ultraviolet absorber at least in the adhesive layer may be used.

Further, the first transparent substrate may be a polyethylene terephthalate film.

A first transparent base film, wherein a hard coat layer is formed on the first transparent base film and an adhesive layer is formed on the second transparent base film. Laminating the surface opposite to the hard coat layer and the adhesive layer formed on the second transparent substrate film, and forming an adhesive layer on the surface of the second transparent substrate film opposite to the adhesive layer. The above object is achieved by a method for producing a hard coat film.

Further, the above object is achieved by a cathode ray tube in which a hard coat film is adhered to the surface of a face plate via an adhesive layer.

Further, the peel strength between the adhesive layer and the face plate is weaker than the peel strength between the second transparent substrate film and the adhesive layer. The object is achieved by a hard coat film that is weaker than the peel strength between the base film and the adhesive layer and weaker than the peel strength between the first transparent base film and the adhesive layer. .

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the basic layer structure of the hard coat film 9 of the present invention. In FIG. 1, 1 is a hard coat layer, 2 is a transparent base film, and 3 is an adhesive layer. The transparent base film 2 includes a first transparent base film 4, an adhesive layer 5, and a second transparent base film 6.

Although not shown in the figure, the hard coat layer 1
A primer layer of about 0.1 to 3 μm may be provided between the transparent base film 4 and the transparent base film 4 to improve the adhesiveness.

As the first transparent substrate film 4, any transparent plastic film can be used, for example, a polyethylene terephthalate film, a polyethylene naphthalate film, a nylon film,
Urethane films are preferably used. The thickness of the transparent substrate film is preferably 1 to 1000 μm, more preferably 10 to 500 μm, and most preferably 12 to 250 μm.
m. If the thickness is less than 12 μm, the strength of the substrate is insufficient, and the substrate is liable to cause thermal damage, curl and wrinkles. If the thickness is more than 250 μm, handling becomes difficult due to too strong elasticity, and the transmittance of the substrate Is also undesirably reduced.

As a material for forming the adhesive layer 5, for example, a urethane-based, epoxy-based, polyester-based or acrylic-based adhesive is preferably used because of its excellent adhesive strength.

As the second transparent substrate film 6, any transparent plastic film can be used, for example, a polyethylene terephthalate film, a polyethylene naphthalate film, a nylon film,
Urethane films are preferably used. The thickness of the transparent substrate film is preferably 1 to 1000 μm, more preferably 10 to 500 μm, and most preferably 12 to 250 μm.
m. When the thickness is less than 12 μm, the strength as a substrate is insufficient, and when the thickness is more than 250 μm, the transmittance is undesirably reduced.

By using a transparent substrate film obtained by bonding the first transparent substrate film 4 and the second transparent substrate film 6 through an adhesive layer, the strength of the substrate film, particularly It can be preferably used because the tensile strength is improved.

The elastic modulus of the first transparent substrate film is preferably 200 to 1000 kgf / mm ² , more preferably 300 to 1000 kgf / mm ² .

Further, it is preferable that the elastic modulus of the second transparent base film is lower than the elastic modulus of the first transparent base film. The reason is that the tensile strength is improved,
Therefore, the transparent base film in which the first transparent base film and the second base film are bonded to each other is suitable as a hard coat film exhibiting a sufficient scattering prevention effect.

As a material for forming the adhesive layer, an acrylic adhesive can be preferably used. In the present invention, a hard coat film provided with an adhesive layer is shown. However, the adhesive layer may not be provided, and when the hard coat film is attached, a transparent substrate film may be attached via an adhesive.

By adding a colorant to any one of the adhesive layer, the adhesive layer and the second transparent substrate film, the colorant is added to the hard coat layer or to the layer directly in contact with the hard coat layer. The transmittance of the hard coat film can be adjusted without lowering the hardness or strength of the hard coat layer. In particular, the use of a CRT display is preferable because the contrast can be improved. Usually, the transmittance is adjusted to 40 to 80%, but it can be used without limitation.

As the colorant, ordinary dyes and pigments can be used, and two or more colorants can be mixed to adjust the hue before use. For example, as organic pigments, carbon black, phthalocyanine pigments, indanthrene blue pigments, quinacridone pigments, watching pigments,
Permanent pigments, anthraquinone pigments, berylen pigments, condensed azo pigments and the like are preferred.

When a colorant is added to any one of the adhesive layer, the adhesive layer and the second transparent substrate film, at least an ultraviolet absorber is added to the adhesive layer in order to improve the light stability of the colorant. Is preferable.

On one or both surfaces of the second transparent substrate film, a coating material in which the same coloring agent as described above is dispersed in a binder resin is applied in a thickness of 1 to 50 μm to form a colored layer. May be used as a transparent base material.

The following are examples of ionizing radiation-curable resins that can be used for the hard coat layer.

The ionizing radiation-curable resin is preferably one having an acrylate-based functional group, more preferably polyester acrylate or urethane acrylate. The polyester acrylate is preferably an acrylate or methacrylate of an oligomer of a polyester-based polyol (hereinafter, acrylate and / or methacrylate is simply referred to as (meth) in the present specification).
Acrylate) or a mixture thereof. The urethane acrylate is formed by acrylate-forming an oligomer composed of a diisocyanate compound from a polyol compound.

The monomers constituting the acrylate include:
Preferably, there are methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, phenyl (meth) acrylate and the like. .

In order to further impart hardness to the coating film of the hard coat layer, a polyfunctional monomer can be used in combination. For example, preferred polyfunctional monomers include trimethylolpropane tri (meth) acrylate, hexanediol (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, Pentaerythritol hexa (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth)
Acrylate, and the like.

Preferred examples of the polyester oligomer include adipic acid and glycol (ethylene glycol, polyethylene glycol, propylene glycol,
Polypropylene glycol, butylene glycol, polybutylene glycol, etc.) and triols (glycerin,
Trimethylolpropane), polyadipate polyol which is a condensation product of sebacic acid with glycol or triol, polysebacate polyol, and the like.

In addition, some or all of the aliphatic dicarboxylic acids can be substituted with other organic acids. For example,
Isophthalic acid, terephthalic acid, phthalic anhydride and the like can be used as components for imparting hardness.

The polyurethane oligomer can be obtained from a condensation product of a polyisocyanate and a polyol. For example, an adduct of methylene bis (p-phenylene diisocyanate), an adduct of hexamethylene diisocyanate / hexanetriol, an adduct of hexamethylene diisocyanate, tolylene diisocyanate, tolylene diisocyanate trimethylolpropane, 1,5-
Naphthylene diisocyanate, thiopropyl diisocyanate, ethylbenzene-2,4-diisocyanate,
Those selected from 2,4-tolylene diisocyanate dimer, hydrogenated xylylene diisocyanate, tris (4-phenyl isocyanate) neophosphate, and the like;
It is obtained by the following reaction with a polyol.

Preferred examples of the polyol include polyether polyols such as polyoxytetramethylene glycol, polyester polyols such as polyadipate polyol and polycarbonate polyol, and copolymers of acrylic esters and hydroxyethyl methacrylate.

Further, when the above-mentioned ionizing radiation-curable resin is used as an ultraviolet-curable resin, α-amyloxime esters and thioxanthones as photopolymerizing agents and n-butylamine as a photosensitizer are included in these resins. , Triethylamine, tri-n-butylphosphine and the like can be used in combination.

Urethane acrylate is rich in elasticity and flexibility and excellent in workability, but cannot obtain a material having a pencil hardness of 2H or more due to poor surface hardness. On the other hand, polyester acrylate can impart hardness by selecting the constituent components of polyester.

In order to obtain a flexible hard coat film, it is preferable to mix 40 to 10 parts by weight of a polyester acrylate with 60 to 90 parts by weight of a urethane acrylate. A hard coat film having both properties can be obtained.

The coating liquid for the hard coat layer has a secondary particle diameter of 20 μm or less, more preferably 0.1 μm or less, for the purpose of adjusting the gloss and imparting a surface slip (not a releasability). It is preferable to add 0.3 to 3 parts by weight of inorganic fine particles having a size of from 15 to 15 μm to 100 parts by weight of the resin component. If the amount is less than 0.3 parts by weight, the desired lubricity cannot be obtained, and if the amount is more than 3 parts by weight, the pencil hardness may decrease.

The fine particles include inorganic fine particles such as silica, magnesium carbonate, aluminum hydroxide and barium sulfate, and fine particles of an organic polymer such as polycarbonate, acrylic resin, polyimide, polyamide, polyethylene naphthalate and melamine resin. Can also be used.

The method of forming the hard coat layer by coating may be a method such as roll coating, gravure coating, bar coating, or extrusion coating, and is conventionally known depending on the characteristics of the coating composition and the coating amount. To form a hard coat layer.

The hard coat film of the present invention may be a hard coat film in which the surface of the hard coat layer is made uneven to impart an antiglare property.

The hard coat film of the present invention may be a hard coat film in which an antireflection layer is further provided on the hard coat layer of the hard coat film in order to give the hard coat film an antireflection effect.

Further, the hard coat film of the present invention contains a conductive agent in the hard coat layer or has a conductive layer formed below or above the hard coat layer in order to provide antistatic performance. It may be.

Next, a method for producing the hard coat film of the present invention will be described.

In the method for producing a hard coat film of the present invention, a hard coat layer is provided on the first transparent base film 4 as shown in FIG.

On the other hand, as shown in FIG. 2B, the adhesive layer 5 is provided on the second transparent base film 6. Then, FIG.
As shown in (c), the surface of the first transparent substrate film 4 opposite to the hard coat layer and the adhesive layer 5 formed on the second transparent substrate film are laminated.

Further, as shown in FIG. 2D, a hard coat film 9 is formed by forming an adhesive layer 3 on the surface of the second transparent base film 6 opposite to the adhesive layer.

FIG. 3 shows the hard coat film 9 of the present invention.
This shows an example of the configuration of a cathode ray tube 10 in which is adhered to a face plate 11 with an adhesive layer 3.

The peel strength between the adhesive layer and the face plate is lower than the peel strength between the second transparent substrate film and the adhesive layer, and the peel strength between the second transparent substrate film and the adhesive layer is lower. If the peel strength is lower than the peel strength and lower than the peel strength between the first transparent substrate film and the adhesive layer, when the hard coat film of the present invention is used for CRT, the hard coat film is used in the laminating step. When the lamination of the film fails and the hard coat film is peeled off (reworkability), C
This is preferable because the adhesive can be easily re-entered into the bonding step without leaving any adhesive on the RT glass, and productivity and workability are improved.

[0055]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail based on embodiments of the present invention.

Example 1 A 188 μm-thick easily-adhesive polyethylene terephthalate film (A4350: trade name, manufactured by Toyobo Co., Ltd.) was used as a first transparent substrate film, and a hard coat layer was formed thereon as ionizing radiation. A curable resin (PETD-31: trade name, manufactured by Dainichi Seika Co., Ltd.) is applied to a dry thickness of about 6 μm, and an acceleration voltage of 1
Cured with an electron beam of 75 KV, irradiation dose of 10 Mrad,
A hard coat layer of about 6 μm was obtained.

Next, as a second transparent substrate film, 7
5 μm thick polyethylene terephthalate film (O-
300: trade name, manufactured by Mitsubishi Polyester Corporation)
A urethane-based adhesive was applied thereon, and an adhesive layer having a dry thickness of about 5 μm was obtained. Then, the surface of the first transparent substrate film opposite to the hard coat layer is bonded to the adhesive layer,
Aging was performed at 0 ° C. for 5 days.

Further, an acrylic pressure-sensitive adhesive (SK2092: trade name, manufactured by Soken Chemical Co., Ltd.) applied on the silicone separator is attached to the surface of the second transparent substrate film opposite to the hard coat layer, and dried. An adhesive layer having a thickness of about 25 μm was formed to obtain a hard coat film.

Example 2 A second transparent substrate film was formed of a 25 μm thick nylon film (Harden N1100:
A hard coat film was obtained in the same manner as in Example 1 except that the trade name was Toyobo Co., Ltd.).

Example 3 A 188 μm-thick easily-adhesive polyethylene terephthalate film (A4350: trade name, manufactured by Toyobo Co., Ltd.) was used as a first transparent base film, and a hard coat layer was formed thereon as ionizing radiation. A curable resin (PETD-31: trade name, manufactured by Dainichi Seika Co., Ltd.) is applied to a dry thickness of about 6 μm, and an acceleration voltage of 1
Cured with an electron beam of 75 KV, irradiation dose of 10 Mrad,
A hard coat layer of about 6 μm was obtained.

Next, as a second transparent substrate film, 7
5 μm thick polyethylene terephthalate film (O-
300: trade name, manufactured by Mitsubishi Polyester Corporation)
An acrylic adhesive (SK Dyne 1386: trade name, manufactured by Soken Kagaku Co., Ltd.) was applied thereon, and a dry thickness of about 5 was applied.
A μm adhesive layer was obtained. Thereafter, the surface of the first transparent substrate film opposite to the hard coat layer is bonded to the adhesive layer,
Aging was performed at 5 ° C. for 5 days.

Further, an acrylic pressure-sensitive adhesive (SK2092: trade name, manufactured by Soken Chemical Co., Ltd.) was applied thereon using a silicone separator to obtain a pressure-sensitive adhesive layer having a dry thickness of about 25 μm. Thereafter, the surface of the second transparent substrate film opposite to the hard coat layer was bonded to an adhesive layer to obtain a hard coat film.

Example 4 A second transparent substrate film was
A hard coat layer was obtained in the same manner as in Example 1 except that a polyester film (Lumirror T-60: trade name, manufactured by Toray Industries, Inc.) dyed to a total light transmittance of 55% and having a thickness of 50 μm was used. Was.

[Comparative Example 1] 18
An 8 μm-thick easily-adhesive polyethylene terephthalate film (A4350, manufactured by Toyobo Co., Ltd.) was used, and an ionizing radiation-curable resin (PETD-3) was formed thereon as a hard coat layer.
1, Dainichi Seika Co., Ltd.) to a dry thickness of about 6 μm, an acceleration voltage of 175 KV, and an irradiation dose of 10 Mr.
A hard coat film was obtained by curing with an electron beam of ad.

The pencil hardness of each hard coat film obtained in Examples 1 to 4 and Comparative Example 1 (please replenish)
And the explosion-proof test results of each hard coat film are shown in Table 1.

[0066]

[Table 1]

FIG. 4 shows an outline of the explosion-proof test based on the UL standard. As shown in FIG. 4 (b), the CRT was fixed on a table so that the display surface was vertical, and was installed such that the center of the display surface was 1 m from the floor surface. 2 from the top of this display surface
Weight 5mm, 25mm from the end (Fig. 4 (a))
An iron ball having a hardness of HRc60 and a diameter of 50 mm was collided with 5 g. The iron ball is fixed to the end of the wire, and 1 mm from the center of the display surface.
The panel was collided perpendicularly to the display surface from a height of 340 mm (2340 mm from the floor) (collision energy was 7 J). Also,
Barriers were provided at positions 90 cm and 150 cm on the front side from the display surface, and a pass / fail judgment was made based on the area reached by the scattered glass fragments and the weight of the fragments. A zone 90 cm from the display surface, zone B from 90 cm to 150 cm, 1 zone
An area of 50 cm or more was defined as a C zone. The allowable range of the debris in each area is “A zone: no restriction”, “B zone: one debris is 0.025 g or less, total weight is 0.1 g or less”, and “C zone: there must be no debris”, If it exceeds this, it is considered to be out of specification. This test was repeated 100 times, and the number of times out of specifications is shown in Table 1.

[0068]

According to the hard coat film of the present invention, a hard coat film using a transparent substrate film has a surface scratch resistance and a strength sufficient to sufficiently show a scattering prevention effect. it can.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a basic layer configuration of a hard coat film of the present invention.

FIG. 2 is a schematic cross-sectional view showing a basic layer configuration of a cathode ray tube to which a hard coat film of the present invention is attached.

FIG. 3 is a schematic view showing a method for producing a hard coat film of the present invention.

FIG. 4 is a schematic view showing an explosion-proof test of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 hard coat layer 2 transparent base film 3 adhesive layer 4 first transparent base film 5 adhesive layer 6 second transparent base film 9 hard coat film 10 cathode ray tube 11 face plate

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shu Koike 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo F-term in Dai Nippon Printing Co., Ltd. 4D075 CA02 DA04 DB36 DC18 4F100 AK25D AK42A AK42B AK51G AT00A AT00B BA04 BA07 BA10C CA07H CA13B CA13D CA13H CB00G CB05D CC00C CC02C EJ53 JK07A JK07B JK12C JN01A JN01B YY00A

Claims (9)

[Claims] 1. A hard coat comprising a transparent base film, a hard coat layer provided on at least one surface of the transparent base film, and an adhesive layer provided on the other surface of the transparent base film. A hard coat film, wherein the transparent base film is formed by laminating a first transparent base film, an adhesive layer, and a second transparent base film. 2. The elastic modulus of the first transparent base film is 200 to 1000 kgf / mm ² , and the elastic modulus of the second transparent base film is equal to that of the first transparent base film. 2. The method according to claim 1, wherein the elastic modulus is lower than the elastic modulus.
The hard coat film as described above. 3. The hard coat film according to claim 1, wherein the adhesive layer and / or the adhesive layer contains a coloring agent. 4. The hard coat film according to claim 1, wherein the second transparent base film contains a colorant. 5. The hard coat film according to claim 3, wherein at least the adhesive layer contains an ultraviolet absorbent. 6. The method according to claim 1, wherein said first transparent substrate is a polyethylene terephthalate film.
5. The hard coat film according to 5. 7. The first transparent base film, wherein the hard coat layer is formed on the first transparent base film, and the adhesive layer is formed on the second transparent base film. Laminating a surface opposite to the hard coat layer and an adhesive layer formed on the second transparent base material film;
The method for producing a hard coat film according to any one of claims 1 to 6, wherein an adhesive layer is formed on a surface of the transparent base film opposite to the adhesive layer. 8. The method according to claim 1, wherein a surface of the face plate is provided.
A cathode ray tube obtained by laminating the hard coat film as described above. 9. A hard coat film used for a cathode ray tube according to claim 8, wherein the peel strength between the adhesive layer and the face plate is higher than that of the second transparent substrate film and the adhesive layer. Weaker than the peel strength between
A hard coat, wherein the peel strength between the transparent substrate film and the adhesive layer is lower than the peel strength between the first transparent substrate film and the adhesive layer. the film.