JP2012048978A - Anisotropic light diffusion film for led lighting, and led lighting equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anisotropic light diffusion film for LED lighting capable of diffusing light emitted from an LED light source and having little illuminance unevenness, and to provide LED lighting equipped with the same.SOLUTION: The anisotropic light diffusion film for LED lighting has a layer formed of a resin composition containing (A) a cyclic olefin system resin 70-90 wt.% and a polyethylene resin 10-30 wt.%.

Description

  The present invention relates to an anisotropic light diffusing film capable of diffusing light of LED lighting, and LED lighting using the anisotropic light diffusing film.

  LED lighting has been attracting attention as a lighting fixture to replace fluorescent lamps and incandescent lamps in recent years because it can be small in size, has low power, has a long life, and has little flicker and heat generation. The light emitted from the LED illumination has a higher illuminance than the fluorescent lamp directly under the LED illumination, but there is a problem that the light diffusion is much less than that of the fluorescent lamp and the illuminance unevenness occurs.

  By the way, although it has hitherto been known that a light diffusing sheet is provided in order to diffuse light emitted from a backlight device of a liquid crystal display panel (see, for example, Patent Documents 1 and 2), LED illumination The present situation is that there is still room for improvement with respect to a sheet or film for improving illumination that produces uniform illuminance over a wide range with respect to a luminaire in which illuminance unevenness occurs.

JP 2001-31774 A JP-A-10-111402

  An object of the present invention is to provide an anisotropic light diffusing film for LED illumination that can diffuse light emitted from an LED light source and has little illuminance unevenness, and LED illumination using the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have emitted a film formed from a resin composition containing a cyclic olefin resin and a polyethylene resin in a specific content ratio from an LED light source. The inventors have found that light is diffused, and have further researched to complete the present invention.

  The present invention has been completed based on such findings.

Item 1. (A) An anisotropic light diffusion film for LED lighting having a layer formed from a resin composition containing 60 to 90% by weight of a cyclic olefin resin and 10 to 40% by weight of a polyethylene resin.

Item 2. further,
(B) having a layer formed from a resin composition containing a cyclic olefin-based resin;
Item 2. The anisotropic light diffusing film for LED lighting according to Item 1, wherein the A layer and the B layer are laminated.

  Item 3. Item 3. The anisotropic light diffusion film for LED lighting according to Item 2, wherein the layers are laminated in the order of A layer / B layer / A layer or A layer / B layer.

  Item 4. Item 4. The anisotropic light diffusing film for LED lighting according to any one of Items 1 to 3, wherein the total thickness of the A layer is 5 to 300 μm.

  Item 5. Item 5. The anisotropic light diffusing film for LED lighting according to any one of Items 2 to 4, wherein the total thickness of the B layer is 5 to 3000 μm.

  Item 6. Item 6. An LED illumination comprising the anisotropic light diffusion film for LED illumination according to any one of Items 1 to 5.

  Item 7. Item 7. The LED illumination according to Item 6, wherein the distance between the anisotropic light diffusion film for LED illumination and the light source of the LED illumination is 0.5 cm or more.

  Hereinafter, the anisotropic light diffusion film for LED illumination of the present invention will be described in detail.

  The anisotropic light diffusion film for LED lighting of the present invention is formed from a resin composition containing a cyclic olefin-based resin and a polyethylene resin.

  Specifically, the cyclic olefin-based resin includes (a) a random copolymer of ethylene or propylene and a cyclic olefin (for example, norbornene and its derivatives, or tetracyclododecene and its derivatives), (b) Ring-opening polymer of cyclic olefin or copolymer with α-olefin, (c) Hydrogenated product of polymer of (b), (d) Unsaturated carboxylic acid and derivatives thereof (a) to ( c) graft modified product, and the like. The specific gravity of the cyclic olefin resin is preferably 1.00 to 1.06, and the number average molecular weight measured by GPC (gel permeation chromatography) method is preferably 1,000 to 1,000,000.

  Moreover, the glass transition temperature of this cyclic olefin resin becomes like this. Preferably it is 50-130 degreeC, More preferably, it is 65-100 degreeC. If it is less than 50 degreeC, the heat resistance of the film surface will fall, and if heat is applied, the surface will stick. On the other hand, when it exceeds 130 ° C., molding becomes difficult.

  The content of the cyclic olefin-based resin is 60 to 90% by weight, preferably about 70 to 90% by weight, more preferably about 75 to 90% by weight, and further preferably about 80 to 85% by weight. When the content of the cyclic olefin-based resin is less than 60% by weight, the total light transmittance of the film decreases, and the loss of light from the LED light source tends to increase. On the other hand, when the content ratio of the cyclic olefin-based resin exceeds 90% by weight, the light diffusing function in a different direction tends to be hardly exhibited. In addition, when using with a single layer as mentioned later, the content ratio of the cyclic olefin-based resin represents the content ratio relative to the entire resin composition when forming a film, and when having a multilayer structure, The content rate with respect to the whole in the resin composition to form is represented.

  Examples of the polyethylene resin include branched, linear, and high density and low density. From the viewpoint of optical anisotropy, branched low density polyethylene or linear low density polyethylene is preferable. preferable.

The density of the polyethylene resin, preferably about 0.88~0.96g / cm ^3, more preferably about 0.88~0.92g / cm ^3, further, the order 0.88~0.91g / cm ³ is preferable. By setting the density of the polyethylene resin within the above range, good optical anisotropy can be expressed.

  The MFR (melt flow rate) measured at a temperature of 230 ° C. and a load of 21.18 N in accordance with JIS K7210 of resin polyethylene is preferably about 1 to 10 g / 10 minutes, and more preferably about 2 to 10 g / 10 minutes.

  The content ratio of the polyethylene resin is 10 to 40% by weight, preferably about 20 to 40% by weight, and more preferably about 25 to 35% by weight. When the polyethylene resin is less than 10% by weight, the light diffusing function in a different direction tends to be hardly exhibited. Moreover, even if a polyethylene resin exceeds 40 weight%, there exists a tendency for the light-diffusion function to a different direction to become difficult to express. In addition, the content rate of a polyethylene resin represents the content rate with respect to the whole resin composition in the case of forming a film, when using by a single layer so that it may mention later, and when it has a multilayer structure, it forms A layer The content rate with respect to the whole in a resin composition is represented.

  Further, in the resin composition containing the resin component, components other than the resin component, for example, optional components such as an antistatic agent, a heat stabilizer, a weathering agent, an antioxidant, and an antiblocking agent are contained at 20% by weight or less. You may do it.

  In the anisotropic light diffusing film for LED lighting of the present invention, the thickness when the layer (A layer) formed from the resin composition containing the cyclic olefin resin and the polyethylene resin is used as a single layer is the strength of the film itself. It is preferably about 5 μm or more, more preferably about 50 μm or more, and more preferably about 100 μm or more from the point that it can be improved, light from the LED illumination light source can be sufficiently diffused, and unevenness in illuminance can be suppressed. preferable. In addition, the thickness is preferably about 300 μm or less, more preferably about 250 μm or less, and even more preferably about 200 μm or less from the viewpoint that light from the LED illumination light source is transmitted and the illuminance is difficult to decrease.

  In the anisotropic light diffusing film for LED lighting of the present invention, a layer (A layer) formed from the resin composition may be used as a single layer, and from the viewpoint of improving the strength of the anisotropic light diffusing film, polyethylene is used. You may have a multilayer structure with B layer formed from the resin composition containing resin. In addition, as a polyethylene resin used for B layer, the same thing as the polyethylene resin used for said A layer is mentioned.

  Further, in the resin composition formed as the B layer, components other than the resin component, for example, optional components such as an antistatic agent, a heat stabilizer, a weathering agent, an antioxidant, an antiblocking agent, etc. at 20% by weight or less. You may contain.

  As a specific example when the anisotropic light diffusion film for LED lighting has a multilayer structure of A layer and B layer, a two-layer structure in which A layer and B layer are laminated, or A layer / B layer / A layer or B layer Examples thereof include a three-layer structure having a structure in which / A layer / B layer are stacked in this order.

  The total thickness of the A layers in the multilayer structure is preferably about 5 μm or more, more preferably about 50 μm or more, more preferably 100 μm from the viewpoint that the strength of the film itself can be sufficiently provided and the anisotropic diffusion function can be sufficiently expressed. More than about is more preferable. Further, from the viewpoint of excellent light transmittance, the total thickness of the A layer is preferably about 300 μm or less, more preferably about 250 μm or less, and further preferably about 200 μm or less.

  The total thickness of the B layer is preferably about 5 μm or more, more preferably about 50 μm or more, and further preferably about 100 μm or more from the viewpoint that the strength of the film itself can be sufficiently provided. Moreover, from the point that it is excellent in film forming winding property, the total thickness of the B layer is preferably about 3000 μm or less, more preferably about 1000 μm or less, and further preferably about 500 μm or less.

  The thickness ratio between the A layer and the B layer is preferably 10: 5 to 10: 100, more preferably 10: 5 to 10:40, and more preferably 10:10 to 10: in the ratio of A layer: B layer. 20 is more preferable.

  In addition, when it has a three-layer structure laminated in order of A layer / B layer / A layer or B layer / A layer / B layer, the thickness of the two A layers or B layers in each layer configuration is the same However, although it may be different, it is preferable to have the same thickness from the viewpoint that the strength can be sufficiently maintained and the anisotropic function can be sufficiently provided.

  The total thickness of the anisotropic light diffusing film for LED illumination of the present invention is preferably about 50 μm or more, more preferably about 100 μm or more, and further preferably about 150 μm or more from the viewpoint that the strength of the film itself can be sufficiently provided. Further, the total thickness is preferably about 3000 μm or less, more preferably about 1000 μm or less, and further preferably about 500 μm or less from the viewpoint of excellent film forming winding property.

  The anisotropic light diffusing film for LED lighting of the present invention is, for example, dry blended with the resin composition of each layer of A layer or A layer and B layer, and each composition is A layer single layer, A layer / B layer, A Supply to the extruder so as to be in the desired order of layer / B layer / A layer or B layer / A layer / B layer, etc., extrude from the T die at a barrel temperature of about 180-250 ° C., and cooling water circulates It can be obtained as a flat monolayer or multilayer film that is coextruded on a chill roll.

  The obtained film has a light transmittance in the direction perpendicular to the die resin flow (MD direction) and the direction of the die resin flow (TD direction), so that the film has anisotropy for diffusing light. Light from the light source of LED illumination can be diffused in the TD direction, and illumination unevenness can be reduced.

  The present invention also relates to LED lighting having the anisotropic light diffusion film for LED lighting.

  The schematic diagram of one Embodiment of the said LED illumination is shown in FIG. The light 2 emitted from the LED illumination 1 having the LED light source is point emission when the anisotropic light diffusion film 3 for LED illumination is not provided. When this point emission light is connected to form surface emission, the LED illumination anisotropic light diffusing film 3 is provided so that the direction in which the point emission continues and the TD direction are parallel, thereby reducing the light source of the LED illumination. Can be diffused in the TD direction, and the light 4 emitted from the light source 2 via the film can be used as a surface light source.

  The distance between the LED light source and the anisotropic light diffusing film for LED illumination depends on the intensity of light emitted from the LED light source, but can sufficiently diffuse the light emitted from the LED light source, and can suppress uneven illumination. In view of the ability to diffuse light in different directions, about 1 cm or more is preferable, about 5 cm or more is more preferable, and about 10 cm or more is more preferable. Moreover, the distance between the LED light source and the anisotropic light diffusion film for LED illumination is not particularly limited, but may be a distance that does not decrease the light transmittance, and is preferably about 50 cm or less, for example.

  Moreover, it is also possible to set it as the LED illumination which can illuminate in a wide range by arranging LED illumination as shown in FIG. 1 in several rows.

  Since the anisotropic light diffusion film for LED lighting of the present invention can diffuse light anisotropically, it can improve unevenness in illuminance in LED lighting. Therefore, it can be suitably used for LED illumination.

It is a schematic diagram of one Embodiment of LED lighting which has the anisotropic light-diffusion film for LED lighting.

  The present invention will be described more specifically with reference to the following examples and comparative examples. In addition, this invention is not limited to the following embodiment.

  The raw material resins used in the following examples and comparative examples are shown below.

Cyclic olefin resin: (Cyclic olefin resin (TOPAS (8007F) manufactured by TOPAS ADVANCED POLYMERS GmbH))
PE resin: (polyethylene resin made by Prime Polymer Co., Ltd. (Evolue SP0510))
Examples 1-3 and Comparative Examples 1-2
The resin composition obtained by blending with the components and compositions shown in Table 1 so as to be the A layer shown in Table 1 is put into an extruder adjusted to 180 to 250 ° C., and a T die at 250 ° C. Extruded and coextruded onto a chill roll in which 80 ° C. cooling water circulates to obtain a flat single layer film.

Examples 4 to 5 and Comparative Example 3
In order to make the layer structure B layer / A layer / B layer, the components and compositions shown in Table 2 are blended, and the resin composition constituting each layer is added to each extruder adjusted to 180 to 250 ° C. A flat three-layer film that is extruded with a T die at 250 ° C., laminated, and coextruded on a chill roll in which cooling water at 80 ° C. circulates so that the order of A layer / B layer / A layer is reached. Got.

Examples 6 to 7 and Comparative Example 4
Compounding with the components and compositions shown in Table 3 so that the layer structure is A layer / B layer, the resin composition constituting each layer is put into each extruder adjusted to 180 to 250 ° C. Extruded with a 250 ° C T-die in order of layer / B layer / A layer, laminated, and coextruded onto a chill roll in which 80 ° C cooling water circulates to obtain a flat two-layer film .

Evaluation of Physical Properties The following properties were evaluated for the single layer, the two-layer film, and the three-layer film described in Examples 1 to 7 and Comparative Examples 1 to 4, respectively. The results are shown in Tables 1-3.

[Total light transmission in MD direction and TD direction]
Light transmission of the obtained film in the dice resin flow direction (MD direction) and the direction perpendicular to the dice resin flow (TD direction) (measured by rotating the film 90 degrees with respect to the MD direction film). The rate was measured and the difference was calculated.

DESCRIPTION OF SYMBOLS 1 LED illumination 2 Light emitted from LED light source 3 Anisotropic light diffusion film for LED illumination 4 Light emitted from LED light source

Claims (7)

(A) An anisotropic light diffusion film for LED lighting having a layer formed from a resin composition containing 60 to 90% by weight of a cyclic olefin resin and 10 to 40% by weight of a polyethylene resin. further,
(B) having a layer formed from a resin composition containing a cyclic olefin-based resin;
The anisotropic light diffusion film for LED lighting according to claim 1, wherein the A layer and the B layer are laminated. The anisotropic light diffusion film for LED lighting according to claim 2, which is laminated in the order of A layer / B layer / A layer or A layer / B layer. The anisotropic light diffusion film for LED lighting according to any one of claims 1 to 3, wherein the total thickness of the A layer is 5 to 300 µm. The total thickness of B layer is 5-3000 micrometers, The anisotropic light-diffusion film for LED lighting in any one of Claims 2-4. LED lighting which has the anisotropic light-diffusion film for LED lighting in any one of Claims 1-5. The LED illumination according to claim 6, wherein the distance between the anisotropic light diffusion film for LED illumination and the light source of the LED illumination is 0.5 cm or more.

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