WO2016088988A1 - Blue light cut protection film - Google Patents

Abstract

The present invention relates to a blue light cut protection film that comprises a base film, an anti-reflection layer formed on a surface of the base film, and an adhesion layer formed on the other surface of the base film, wherein the adhesion layer includes one or more types of dyes that absorb a particular wavelength band, and thereby blocks 95% or more of light in the 380 nm wavelength region, and blocks 40% or more of light in the 430 nm wavelength region. The blue light cut protection film of the present invention can be attached to the front surface of an LCD or LED display, efficiently blocking harmful blue light, which allows light to pass that will not cause straining problems even when the screen is looked at for a long time, and thereby reduces brightness degradation and widens the colour region (colour gamut).

Description

Blue Light Cut Protective Film

The present invention relates to a protective film for blocking harmful light in the blue light area when applied to the front of the display (blue light cut, blue light cut).

Blue light refers to blue light having a wavelength range of 380 to 495 nm among visible light, and has the shortest wavelength among visible light visible to the human eye and has strong energy close to ultraviolet light, so that it is not absorbed by the cornea or lens and reaches the retina. Can reach and cause eye fatigue, as well as damage the eye. When the eyes are exposed to this blue light for a long time, clear vision is obstructed and various symptoms such as dry eyes, eye strain, insomnia, stiff shoulders and back pain occur.

Recently, smart devices such as PCs and mobile phones have become an indispensable necessity for modern people due to their wide spread, but there are many harmful blue lights in LCDs, LED displays, and lighting devices of smart devices, which threaten users' sight. .

Therefore, the blue light cut protection film that blocks harmful light in the blue light area is commercialized by applying it to the front of the display through detachment and attachment. However, the conventional blue light cut protection film reduces the harmful blue light area to 30% or less. It only blocks, requiring a protective film with higher blue light cut capability.

Accordingly, an object of the present invention is to provide a blue light cut protective film that can widen the color gamut while blocking harmful light in the blue light region at a high level as a protective film detachable on the front of the display.

The present invention to achieve the above object,

A base film, an antireflection layer formed on one surface of the base film, and an adhesive layer formed on the other surface of the base film, wherein the adhesive layer includes one or more dyes absorbing a specific wavelength band, thereby providing light in a 380 nm wavelength region. It provides a blue light cut protection film having a function of shielding more than 95% and shielding more than 40% of light in the 430 nm wavelength region.

When the protective film of the present invention is attached to the front of the LCD, LED display, while providing a surface reflection prevention function, harmful blue light wavelength region (380 ~ 495 nm) of various light emitted from the display screen due to the combination of the dye in the adhesive layer By effectively blocking, the user can pass an appropriate value as long as the screen is long enough to reduce luminance deterioration and widen the color gamut. It can also help keep your eyes healthy by blocking harmful blue light.

1 is a cross-sectional view showing the structure of a conventional blue light cut protective film.

Figure 2 shows the structure of a blue light cut protective film according to an embodiment of the present invention as a cross-sectional view.

3 is a graph showing the transmission characteristics of the protective film prepared in Examples 1 to 3 and Comparative Examples 1 to 3 and the emission intensity of the light emitting device.

<Description of the code>

1: base film

2: blue light cut reflection ring layer

3: adhesion layer

4: protective layer

5: release liner

2 ': antireflection layer

3 ': blue light cut adhesive layer

The blue light cut protective film of the present invention comprises (i) a base film, (ii) an antireflection layer formed on one surface of the base film, and (iii) a dye formed on the other side of the base film and absorbing a specific wavelength band. It includes a pressure-sensitive adhesive layer in a stacked form, and has a function of shielding 95% or more of light in the 380 nm wavelength region and 40% or more of light in the 430 nm wavelength region (blue light cut function). The blue light cut protective film of the present invention may further include a protective layer on the opposite surface of the base film contact surface of the anti-reflection layer, and may further include a release liner on the opposite side of the base film contact surface of the adhesive layer. .

The structure of a conventional blue light cut protective film is shown in Figure 1, the structure of a blue light cut protective film according to an embodiment of the present invention is shown in FIG.

Referring to FIG. 1, a conventional blue light cut protective film sequentially includes a release liner 5, an adhesive layer 3, a base film 1, a blue light cut reflective ring layer 2, and a protective layer 4. Included in stacked form. That is, the conventional blue light cut protective film includes one or more dyes capable of performing a blue light cut function in the antireflection layer.

On the other hand, referring to Figure 2, the blue light cut protective film according to an embodiment of the present invention is a release liner (5), blue light cut adhesive layer (3 '), base film (1), reflective ring layer (2') ) And the protective layer 4 are sequentially stacked. That is, the blue light cut protective film of the present invention comprises a blue light region (380 ~ 495 nm wavelength region) by including one or more, preferably two or more dyes that can perform a blue light cut function in the adhesive layer. Compared to the 30% or less level and no effect on color gamut at all, the blue gamut can be blocked at a high level of 40% or more while the color gamut can be widened.

(i) base film

The base film may be a transparent plastic plastic substrate, preferably has good adhesiveness with the resin, the transmittance of light incident from the rear side should be 90% or more, and the surface smoothness should be uniform so as not to bring about variations in luminance. do.

Specific examples of suitable materials for the base film include polyethylene terephthalate (PET), cellulose triacetate (TAC), polycarbonate (PC), polyether sulfone (PES), polyacrylate (PAR), Polyetherimide (PEI), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polyallylate, polyimide, cellulose acetate propionate acetate propionate (CAP) and mixtures thereof, preferably polyethylene terephthalate (PET), cellulose triacetate (TAC) or polycarbonate (PC).

The thickness of the base film may be 30 to 250 ㎛, preferably 40 to 125 ㎛.

(ii) antireflection layer

The antireflection layer may be made of a resin such as a thermoplastic resin, a thermosetting resin, an ionizing radiation (ultraviolet or electron beam) curable resin.

Specific examples of the thermoplastic resin and the thermosetting resin include polyester resin, acrylic resin, acrylic urethane resin, polyester acrylate resin, polyurethane acrylate resin, epoxy acrylate resin, urethane resin, epoxy resin, poly Carbonate resin, cellulose resin, acetal resin, polyethylene resin, polystyrene resin, polyamide resin, polyimide resin, melamine resin, phenol resin, silicone resin, and mixtures thereof.

As the ionizing radiation curable resin, a photopolymerizable prepolymer crosslinked and cured by irradiation with ionizing radiation may be used. Examples of the photopolymerizable prepolymer may include a cationic polymerization type prepolymer and a radical polymerization type prepolymer. Examples of the cationic polymerization type photopolymerizable prepolymers include epoxy resins and vinyl ether resins. Examples of the epoxy resins include bisphenol epoxy resins, novolac epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. And mixtures thereof. As the radically polymerized photopolymerizable prepolymer, an acrylic prepolymer (hard prepolymer) having two or more acryloyl groups in one molecule and becoming a three-dimensional network structure through crosslinking curing may be particularly preferably used from the viewpoint of hard coating property. Examples of the acrylic prepolymers include urethane acrylate, polyester acrylate, epoxy acrylate, melamine acrylate, polyfluoroalkyl acrylate, silicone acrylate, and mixtures thereof.

The antireflection layer includes a photopolymerizable monomer and / or a photopolymerization initiator in order to impart various performances such as improving crosslinking curability or adjusting curing shrinkage.

Examples of photopolymerizable monomers include monofunctional acrylic monomers (e.g. 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, butoxyethyl acrylate, etc.), bifunctional acrylic monomers ( For example, 1, 6-hexanediol diacrylate, neopentyl glycol acrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, hydroxy pivalic acid ester neopentyl glycol diacrylate, etc.), trifunctional or more acryl A monomer (for example, dipentaerythritol hexaacrylate, trimethyl propane triacrylate, pentaerythritol triacrylate, etc.) is mentioned. In addition, examples of the photopolymerization initiator may be one or more photoinitiators such as oxime esters, acetophenones, benzophenones, benzoin and benzoyl, xanthones, triazines, halomethyloxadiazoles, and ropindimers. Can be.

The anti-reflection layer may include additional additives as necessary in a range that does not impair the effects of the present invention.

The anti-reflection layer may be dry coated or wet coated on one surface of the base film, or may be formed on a separate support and then attached to one surface of the base film using an adhesive.

The thickness of the antireflective layer may be 50 to 200 nm, preferably 80 to 120 nm.

(iii) Adhesive layer

The adhesive layer includes a pressure-sensitive adhesive (PSA) to attach the protective film to the front surface of the display, and includes 95% of light in the 380 nm wavelength region by including at least one dye that absorbs a specific wavelength band. It shields more than 40% of light in the 430 nm wavelength region.

Examples of the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer may include one or more pressure-sensitive adhesives selected from the group consisting of acrylic, urethane, epoxy, and silicone pressure sensitive adhesives, preferably urethane, silicone pressure sensitive adhesives, or mixtures thereof.

The dye used in the present invention may be a combination of one or more dyes having a main absorption wavelength band of 380 to 420 nm and one or more dyes having a main absorption wavelength band of 560 to 580 nm.

Examples of dyes that shield wavelengths of 380 to 420 nm include hydroxy benzotriazole (HB), Tris-Resorcinol-Triazine chromophore (TRTC), and hydroxyphenyl-benzo Triazole chromophore (Hydroxylphenyl-benzotriazole chromophore, HBC) series is mentioned.

Examples of the dye that shields the wavelength of 560 to 580 nm include tetraaza porphyrin (TAP), rhodamine (RH), squaraine (Squarine, SQ), and cyanine (CY).

The dye may be used in an amount of 0.01 to 10% by weight, preferably 0.05 to 7% by weight based on the total weight of the adhesive layer.

If necessary, the adhesive layer may further include a sunscreen to block UV light. The sunscreen used is absorbing (shielding) light of 420 nm or less, which is tris-resorcinol-triazine chromophore (TRTC), hydroxybenzotriazole (HOBT) ), Hydroxyphenyl-benzotriazole chromophore (HBC, hydroxylphenyl-benzotriazole chromophore) series can be used, can be used alone or in combination of two or more. The adhesive layer may include the sunscreen in an amount of 0.01 to 10% by weight, preferably 0.05 to 7% by weight based on the total weight of the adhesive layer.

The pressure-sensitive adhesive layer may include additional additives as necessary in a range that does not impair the effects of the present invention.

The adhesive layer may be formed by wet coating on the other surface of the base film.

The adhesive layer may have a thickness of 2 to 100 μm, 5 to 100 μm, and preferably 15 to 25 μm.

The base film, the anti-reflection layer and the adhesive layer may have a material, thickness, shape, and the like, which are conventionally acceptable in the art, and may be variously modified as necessary.

In addition to the constituent layers, the blue light cut protective film of the present invention may further include a protective layer on the opposite surface of the base film contact surface of the anti-reflection layer, and a release liner on the opposite side of the base film contact surface of the adhesive layer. The protective layer and the release liner may further include a material, a thickness, a shape, and the like, which are commonly accepted in the art, and may be variously modified as necessary.

The blue light cut protective film according to the present invention shields 95% or more of the light in the 380 nm wavelength region and 40% or more of the light in the 430 nm wavelength region. In addition, the blue light cut protective film according to the present invention can widen the color gamut (color gamut) by more than 5% when attached to the front of the light emitting display.

Thus, when the protective film of the present invention is attached to the front of the LCD, LED display, while providing a surface reflection prevention function, the harmful blue light wavelength region (380 ~ 380) among the various light emitted from the display screen due to the combination of the dye in the adhesive layer By blocking the 495 nm efficiently, it is possible to pass the appropriate numerical value to the extent that the screen is long enough to reduce the luminance deterioration and widen the color gamut. It can also help keep your eyes healthy by blocking harmful blue light.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example  One

After preparing a pressure-sensitive adhesive solution by mixing 35% by weight of SHP1 SHP1 as a pressure-sensitive adhesive and 65% by weight of methyl ethyl ketone (MEK) as a solvent, Ciba Tinuvin 312 and SK Chemicals SK-d400 (Note) Absorption wavelength band: 380 to 420 nm) and SK Chemicals SK-d590 (main absorption wavelength band: 560 to 580 nm) were added in an amount of 0.2, 0.03 and 0.03 parts by weight with respect to 100 parts by weight of the pressure-sensitive adhesive solution, respectively. The composition was prepared.

On the other side of the 100-μm-thick transparent PET base film having an anti-reflection layer having a thickness of 0.1 μm on one side, the adhesive layer composition was coated using a gap coater, dried and cured to form an adhesive layer having a thickness of 20 μm. By this, the protective film was completed.

Example 2

Except that Ciba Tinuvin 312, SK Chemicals SK-d400 and SK Chemicals SK-d590 were added in an amount of 0.2, 0.03 and 0.02 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive solution as a dye in preparing the adhesive layer composition. A protective film was prepared by performing the same process as in Example 1.

Example 3

Except that Ciba Tinuvin 312, SK Chemicals SK-d400 and SK Chemicals SK-d590 were added in an amount of 0.2, 0.03 and 0.01 parts by weight based on 100 parts by weight of the pressure-sensitive adhesive solution as a dye in preparing the adhesive layer composition. A protective film was prepared by performing the same process as in Example 1.

Comparative Example 1

A protective film was prepared by the same process as in Example 1, except that no dye was used when forming the adhesive layer.

Comparative Examples 2 and 3

Blue light cut LCD protective film (Elecom (Japan); Comparative Example 2) and Healing Shield Anti-Blue (Fontary, Korea) which are commercially available blue light cut films as Comparative Examples 2 and 3, respectively: Comparative Example 3) was used.

Experimental Example

The optical spectrum (light transmittance) of the protective films prepared in Examples and Comparative Examples was measured using a spectrophotometer (U4100; Hitachi); After attaching to the surface of the light emitting display product, the color gamut (color gamut) was measured using a luminance meter (CS-2000; Minolta). The results are shown in Table 1 and FIG. 3. The color gamut represents the color reproducibility ratio (color reproduction area) after the protective film is attached to the state where the protective film is not present on the light emitting display surface. If the color gamut is more than 100%, the color reproduction area is increased.

	Film transmittance	Transmittance at 380 nm	Transmittance at 430 nm	Color characteristics (a * / b *)	Gamut	Yellow index
Example 1	75.8%	4.6%	59.4%	-1.9 / -0.8	107.0%	-2.9
Example 2	80.1%	4.8%	59.2%	-1.4 / 1.7	105.8%	2.0
Example 3	79.0%	4.8%	59.7%	0.2 / 1.9	105.2%	3.0
Comparative Example 1	94.8%	87.9%	92.1%	-0.37 / 1.48	100.0%	2.7
Comparative Example 2	76%	67.8%	73.9%	-0.18 / -0.83	100.1%	-1.7
Comparative Example 3	93.3%	64.5%	75.9%	-2.89 / 7.01	100.2%	11

Table 1 and Figure 3, the protective film of the embodiment according to the present invention can be seen that the shielding of the light in the 380 nm wavelength region of more than 95% and the light in the 430 nm wavelength region of more than 40% compared to the case of the comparative example . In addition, the comparative example has almost no effect with respect to the color gamut, whereas in the case of the example, the color gamut is widened by 5% or more by being attached to the front surface of the light emitting display. On the other hand, in the case of Comparative Example 3 has a yellowish yellow light, it can be seen that the protective films of the embodiment is not.

Claims (7)

1. A base film, an antireflection layer formed on one surface of the base film, and an adhesive layer formed on the other surface of the base film, wherein the adhesive layer includes one or more dyes absorbing a specific wavelength band, thereby providing light in a 380 nm wavelength region. Blue light cut protective film having a function of shielding more than 95% and shields more than 40% of the light in the 430 nm wavelength range.
2. The method of claim 1,

   Said at least one dye is a combination of at least one dye having a main absorption wavelength band of 380 to 420 nm and at least one dye having a main absorption wavelength band of 560 to 580 nm.
3. The method of claim 2,

   The dyes having the main absorption wavelength band of 380 to 420 nm include hydroxy benzotriazole (HB), tris-resorcinol-triazine chromophore (TRTC) and hydroxyphenyl. Blue light cut protective film, characterized in that selected from the group consisting of benzotriazole chromophore (Hydroxylphenyl-benzotriazole chromophore, HBC) series dyes.
4. The method of claim 2,

   The dye having a main absorption wavelength range of 560 to 580 nm is a dye of tetraaza porphyrin (TAP), rhodamine (RH), squaraine (Squarine, SQ) and cyanine (Cyanine, CY) series. Blue light cut protective film, characterized in that selected from the group consisting of.
5. The method of claim 1,

   Blue light cut protective film, characterized in that the at least one dye is used in an amount of 0.01 to 10% by weight based on the total weight of the adhesive layer.
6. The method of claim 1,

   Blue light cut protective film, characterized in that the adhesive layer comprises a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive or a mixture thereof.
7. The method of claim 1,

   The protective film is attached to the front of the light emitting display blue light cut protective film, characterized in that to extend the color gamut (color gamut) by more than 5%.

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