JP2011248104A - Light extraction film and manufacturing method of the same - Google Patents

Abstract

An object of the present invention is to provide a light extraction film having high utilization efficiency of light emitted from organic EL illumination, excellent in luminance and durability of the film, excellent in adhesion prevention and removal of dust, dirt, etc., and a method for producing the same. is there.
A transparent plastic film having a light diffusing layer on at least one surface, wherein the light diffusing layer comprises (X) particles comprising a first polymer and at least one of the surfaces of the (X) particles. A light extraction film comprising: organic modified particles (A) having a (Z) particle composed of a second polymer, and a binder polymer (B).
[Selection figure] None

Description

  The present invention relates to a light extraction film used for increasing luminous efficiency of organic EL lighting, LED lighting, various display devices, backlights for liquid crystal displays, and the like, and a method for producing the same.

  Lighting devices such as organic EL lighting, LED lighting, various display display devices, and backlights for liquid crystal displays are composed of a plurality of members, and the light emitted from the light source is totally reflected by the difference in refractive index between the members. It is attenuated by such factors as not being able to be extracted effectively.

  For example, organic EL (electroluminescence) illumination is a self-luminous illumination device, and research and development is actively progressing for various display display devices, backlights for liquid crystal displays, flat illumination applications, and the like. The organic EL display has the advantages of display performance such as higher visibility and no viewing angle dependency compared to conventional CRTs and liquid crystal displays, and also has the advantage of being lighter and thinner. .

  On the other hand, organic EL lighting for lighting applications is a uniform surface light source that is different from LED, which is a highly directional point light source, and can be made thin, light weight, and have a small number of components. By using it, there is a possibility that illumination having a shape that could not be realized in the past can be realized. As practical use approaches in such a flow, further improvement in luminous efficiency is desired.

  The organic EL illumination is formed as an organic EL surface light emitter by providing an anode electrode, an organic EL element, and a cathode electrode in this order on one surface of a transparent substrate. The light emitted from the organic EL element by applying a voltage between the anode electrode and the cathode electrode is extracted through the transparent substrate. However, the light emitted from the organic light emitting layer is totally reflected depending on the angle of incidence on the adjacent layer interface having a different refractive index, is guided inside the display device, and cannot be extracted outside. The ratio of light to be guided is determined by the relative refractive index with the adjacent layer. In the case of general organic EL lighting using a glass substrate as a transparent substrate, the light extraction efficiency is as low as about 20%. It is.

  As a technique for improving the light extraction efficiency from the transparent substrate, for example, a method in which a concavo-convex structure is provided on the transparent substrate (for example, see Patent Documents 1 and 2), and a method for arranging a microlens (for example, Patent Document 3). 4), a method of installing a diffraction grating (see, for example, Patent Document 5), a method in which an organic EL element itself is subjected to uneven processing (for example, see Patent Document 6), and the like. In addition, many attempts have been made to take out guided light confined inside the device by physically changing the shape of the substrate. However, these are complicated in construction, require strict optical design, and are often lacking in practicality in consideration of actual manufacturing technology and cost, and the light extraction efficiency is also insufficient. there were. In addition, when the size of the structure that causes the reflection of light and the transmission angle to be disturbed, such as a diffraction grating or a microlens, is about the wavelength of light to about 10 μm, a color shift due to light interference occurs, It is a problem.

  As a relatively simple method, a method has been proposed in which a light diffusing layer is formed and the light refraction angle is changed to reduce light in the total reflection condition. For example, a method of dispersing a scattering material having a refractive index different from that of the mother layer in the transparent mother layer (see, for example, Patent Document 7), and a method of arranging an optical layer in which beads are dispersed in a binder in a transparent base material layer (For example, refer to Patent Documents 8 and 9) There are many proposals such as a method of arranging a layer in which transparent particles partially protrude (for example, refer to Patent Document 10). However, with these proposals, it cannot be said that the light extraction efficiency has been sufficiently improved, and further improvements have been desired.

  In addition, these proposals are characterized by the difference in refractive index between the diffusing particles and the binder serving as the base layer, the characteristics, size, and dispersion state of the diffusing particles. In most cases, spherical powder beads are used as the organic particles, and general-purpose commercial products are used as they are, and the concept of improving the light extraction efficiency by controlling the shape of the diffusing particles is completely considered. Absent.

JP-A-9-63767 JP 2000-231985 Japanese Patent Laid-Open No. 9-171892 JP 2004-047298 A JP 2009-083148 A JP 2002-31567 A JP 2001-356207 A JP 2003-100444 A JP 2003-109747 A Special table 2009-522737

  The present invention has been made in view of such problems of the prior art, and the problem is that the use efficiency of light emitted from organic EL illumination is high, the luminance and the durability of the film, An object of the present invention is to provide a light extraction film excellent in adhesion prevention and removal properties such as dust and dirt, and a method for producing the same.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be achieved by using specific organic irregularly shaped particles and a binder polymer, thereby completing the present invention. It came.

That is, according to this invention, the light extraction film used in order to improve luminous efficiency, such as the organic EL illumination shown below, and its manufacturing method are provided.
1) Organic modified particles having (X) particles made of a first polymer and (Z) particles made of a second polymer disposed on at least a part of the surface of the (X) particles. A light extraction film comprising (A) and a binder polymer (B).
2) The light extraction film according to claim 1, wherein the number average particle diameter of the organic irregular shaped particles (A) is 0.8 to 10 μm.

3) The ratio of the number average particle diameter (Lx) of the (X) particles to the number average particle diameter (Lz) of the (Z) particles in the organic irregular particles (A) is (Lx) / (Lz). The light extraction film according to claim 1 or 2, wherein = 0.05 to 20.
4) At least one hemispherical protrusion composed of a part of the monomer component constituting the (Z) particle is disposed on the surface of the (X) particle in the organic irregular particle (A). The light extraction film according to any one of claims 1 to 3.
5) The light extraction film according to any one of claims 1 to 4, wherein the binder polymer (B) is a siloxane-containing acrylic resin.
6) The content of the organic irregularly shaped particles (A) and the binder polymer (B) is 1 to 90% by mass of the organic irregularly shaped particles (A) and 10 to 99% by mass of the binder polymer (B) (provided that (A The light extraction film according to claim 1, wherein: (B) = 100% by mass).

7) Of the refractive index Rx of the (X) particles in the organic fine particles (A) and the refractive index Rz of the (Z) particles, the refractive index _RA having the higher refractive index, the binder polymer ( light extraction film according to any one of claims 1 to 6, the difference in refractive index R _B of B) is characterized in that 0.05 to 0.2.
8) The light extraction film according to any one of claims 1 to 7, wherein the total light transmittance is 50% or more and the haze is 60% or more.
9) The light extraction film according to any one of claims 1 to 8, further comprising a sulfonated polymer (E).
10) The light extraction according to claim 9, wherein the sulfonated polymer (E) is at least one of a sulfonated conjugated diene polymer (E-1) and a polystyrene sulfonic acid (E-2). the film.

11) The light extraction film has an aqueous emulsion containing polymer particles (A-1) made of organic irregular particles (A) and an aqueous emulsion containing polymer particles (B-1) made of a binder polymer (B). The light extraction film according to claim 1, wherein the light extraction film is formed of an aqueous emulsion composition.
12) The light according to any one of claims 1 to 11, wherein a light diffusion layer containing the organic irregular particles (A) and the binder polymer (B) is formed on a transparent plastic film. Take out film.
13) It is for organic EL illumination, The light extraction film in any one of Claims 1-12 characterized by the above-mentioned.

14) Organic EL illumination provided with the light extraction film according to claim 13.
15) A light extraction film manufacturing method comprising a light diffusion layer formed of a composition containing the above-mentioned organic irregular particles (A) and a binder polymer (B) on at least one surface of a transparent plastic film, The light diffusion layer has (X) particles made of a first polymer, and (Z) particles made of a second polymer disposed on at least a part of the surface of the (X) particles. It is formed by an aqueous emulsion composition having an aqueous emulsion containing polymer particles (A-1) made of organic irregularly shaped particles (A) and an aqueous emulsion containing polymer particles (B-1) made of a binder polymer (B). A method for producing a light extraction film characterized by the above.

  The light extraction film of the present invention has a light diffusing layer containing organic irregular particles (A), thereby improving the light extraction efficiency of light emitted from the organic EL layer, thereby improving the light utilization efficiency, It is possible to improve brightness, durability of the film, and prevention of adhesion and removal of dust and dirt.

It is a schematic diagram which shows one Embodiment of the organic irregular shaped particle | grains of this invention. It is a schematic diagram which shows other embodiment of the organic deformed particle of this invention. It is a schematic diagram which shows other embodiment of the organic type irregular shape particle | grains of this invention. It is a schematic diagram which shows other embodiment of the organic type irregular shape particle | grains of this invention. It is a schematic diagram which shows other embodiment of the organic type irregular shape particle | grains of this invention. It is a schematic diagram which shows other embodiment of the organic type irregular shape particle | grains of this invention. It is a schematic diagram which shows other embodiment of the organic type irregular shape particle | grains of this invention. It is a schematic diagram explaining the major axis and minor axis of organic irregular shaped particles. (Z) It is a schematic diagram which shows the initial stage of a mode that particle | grains grow. (Z) It is a schematic diagram which shows the intermediate | middle stage of a mode that particle | grains grow. (Z) It is a schematic diagram which shows the last stage of a mode that particle | grains grow.

  Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

<1. Organic irregular particles (A)>
The organic modified particles (A) of the present invention are composed of (X) particles composed of a first polymer and a second polymer disposed on at least a part of the surface of the (X) particles (Z ) Particles. The number average particle diameter of the organic irregularly shaped particles (A) is preferably 0.8 to 10 μm. The details will be described below.

1) (X) Particles The (X) particles constituting the organic modified particles of the present invention are composed of the first polymer. This first polymer is derived from seed polymer particles capable of absorbing an oil-soluble polymerization initiator containing an organic compound having a water solubility of 10 ⁻² mass% or less, and (X1) an aromatic vinyl monomer. Units (hereinafter also referred to as “structural units (X1)”), (X2) units derived from polar functional group-containing monomers (hereinafter also referred to as “structural units (X2)”), and (X3) other units It preferably contains a unit derived from a monomer (hereinafter also referred to as “structural unit (X3)”). This first polymer is obtained by adding (X1) an aromatic vinyl monomer, (X2) to seed polymer particles capable of absorbing an oil-soluble polymerization initiator containing an organic compound having a water solubility of 10 ⁻² mass% or less. It can be obtained by absorbing the polar functional group-containing monomer and (X3) other monomers and polymerizing the monomers (X1) to (X3). Specific examples of the seed polymer particles include styrene polymers such as styrene polymers and styrene-butadiene copolymers, acrylic ester polymers, and the like.

-(I) (X1) A unit derived from an aromatic vinyl monomer As the aromatic vinyl monomer used for constituting the structural unit (X1), styrene, α-methylstyrene, 2-methyl Styrene, 3-methylstyrene, 4-methylstyrene, 4-ethylstyrene, 4-tert-butylstyrene, 3,4-dimethylstyrene, 4-methoxystyrene, 4-ethoxystyrene, 2-chlorostyrene, 3-chlorostyrene , 4-chlorostyrene, 2,4-dichlorostyrene, 2,6-dichlorostyrene, 4-chloro-3-methylstyrene, divinylbenzene, 1-vinylnaphthalene, 2-vinylpyridine, 4-vinylpyridine, etc. I can. Of these, styrene, divinylbenzene, and α-methylstyrene are preferable. These aromatic vinyl monomers can be used singly or in combination of two or more.

  The proportion of the structural unit (X1) contained in the first polymer is 10 to 95 masses when the total of the structural unit (X1), the structural unit (X2), and the structural unit (X3) is 100 mass%. %, Preferably 15 to 90% by mass. When the proportion of the structural unit (X1) contained in the first polymer is less than 10% by mass, the polymerization stability of the organic irregularly shaped particles tends to decrease. On the other hand, when it exceeds 95% by mass, it tends to be difficult to obtain organic irregular particles.

-(Ii) (X2) Unit derived from polar functional group-containing monomer The polar functional group-containing monomer used for constituting the structural unit (X2) is a single monomer having a polar functional group in its molecule Is the body. Preferred examples of this polar functional group include a carboxyl group, a cyano group, a hydroxyl group, an epoxy group, and an ester group. Specific examples of the polar functional group-containing monomer include monomers shown in the following (1) to (5). In addition, the monomer illustrated below can be used individually by 1 type or in combination of 2 or more types.

  (1) Carboxyl group-containing monomer: (meth) acrylic acid, crotonic acid, cinnamic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, monomethyl maleate, monoethyl maleate, itaconic acid Carboxyl group-containing unsaturated monomers such as monomethyl, monoethyl itaconate, mono-2- (meth) acryloyloxyethyl hexahydrophthalate, and anhydrides thereof. Of these, (meth) acrylic acid is preferred.

  (2) Cyano group-containing monomers: vinyl cyanide monomers such as (meth) acrylonitrile, crotonnitrile, cinnamate nitrile; 2-cyanoethyl (meth) acrylate, 2-cyanopropyl (meth) acrylate, 3 -Cyanopropyl (meth) acrylate. Of these, (meth) acrylonitrile is preferable.

  (3) Hydroxyl group-containing monomer: hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, neopentyl glycol mono (meth) Hydroxy (cyclo) alkyl mono (meth) acrylates such as acrylate; substituted hydroxy (cyclo) alkyl mono (3-chloro-2-hydroxypropyl (meth) acrylate, 3-amino-2-hydroxypropyl (meth) acrylate and the like ( (Meth) acrylates. Of these, hydroxymethyl (meth) acrylate is preferable.

  (4) Epoxy group-containing monomer: allyl glycidyl ether, glycidyl (meth) acrylate, methyl glycidyl methyl acrylate, epoxidized cyclohexyl (meth) acrylate. Of these, glycidyl (meth) acrylate is preferable.

  (5) Ester group-containing monomer: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate (Cyclo) alkyl (meth) acrylates such as cyclohexyl (meth) acrylate; alkoxy (cyclo) alkyl (meth) acrylates such as 2-methoxyethyl (meth) acrylate and p-methoxycyclohexyl (meth) acrylate; trimethylol Polyvalent (meth) acrylates such as propane tri (meth) acrylate; vinyl esters such as vinyl acetate, vinyl propionate and vinyl versatate. Of these, butyl (meth) acrylate is preferable.

  The proportion of the structural unit (X2) contained in the first polymer is 5 to 85 when the total of the structural unit (X1), the structural unit (X2), and the structural unit (X3) below is 100% by mass. It is preferable that it is mass%, and it is still more preferable that it is 10-80 mass%. When the proportion of the structural unit (X2) contained in the first polymer is less than 5% by mass, it tends to be difficult to obtain organic irregular particles. On the other hand, if it exceeds 85% by mass, the light diffusibility tends to be inferior.

-(Iii) (X3) Units derived from other monomers The first polymer may be a monomer composed of other monomers copolymerizable with the aforementioned various monomers, if necessary. Units may be included. Examples of other monomers constituting the structural unit (X3) include those shown below.

  N-methylol unsaturated carboxylic acid amides such as N-methylol (meth) acrylamide and N, N-dimethylol (meth) acrylamide; aminoalkyl group-containing acrylamides such as 2-dimethylaminoethylacrylamide; (meth) acrylamide; Amides or imides of unsaturated carboxylic acids such as N-methoxymethyl (meth) acrylamide, N, N-ethylenebis (meth) acrylamide, maleic acid amide, maleimide; N-methylacrylamide, N, N-dimethylacrylamide, etc. N-monoalkyl (meth) acrylamides, N, N-dialkylacrylamides; aminoalkyl group-containing (meth) acrylates such as 2-dimethylaminoethyl (meth) acrylate; 2- (dimethylaminoethoxy) ethyl (meth) Acry (Meth) acrylates containing aminoalkoxyalkyl groups such as vinylate; halogenated vinyl compounds such as vinyl chloride, vinylidene chloride and fatty acid vinyl ester; 1,3-butadiene, 2-methyl-1,3-butadiene, 2 -Conjugated diene compounds such as chloro-1,3-butadiene and 2,3-dimethyl-1,3-butadiene. Of these, N-methylol (meth) acrylamide and (meth) acrylamide are preferable. These other monomers can be used alone or in combination of two or more.

  The proportion of the structural unit (X3) contained in the first polymer is 0 to 10 mass when the total of the structural unit (X1), the structural unit (X2), and the structural unit (X3) is 100 mass%. %, Preferably 0 to 5% by mass. When the proportion of the structural unit (X3) contained in the first polymer is 10% by mass or more, the polymerization stability of the organic irregular particles tends to be lowered.

2) (Z) particles The (Z) particles constituting the organic modified particles of the present embodiment are made of the second polymer. This second polymer includes, for example, (Z1) an aromatic vinyl monomer unit (hereinafter also referred to as “structural unit (Z1)”), (Z2) a polar functional group-containing monomer unit ( Hereinafter, it is preferable to include (constituent unit (Z2)) and (Z3) other monomer units (hereinafter also referred to as “constituent unit (Z3)”).

(I) (Z1) Aromatic vinyl monomer unit The aromatic vinyl monomer used to constitute the structural unit (Z1) is used to constitute the structural unit (Z1). The same thing as the aromatic vinyl-type monomer obtained can be mentioned. Of these, styrene, divinylbenzene, and α-methylstyrene are preferable. These aromatic vinyl monomers can be used singly or in combination of two or more.

  The proportion of the structural unit (Z1) contained in the second polymer is 10 to 100% by mass when the total of the structural unit (Z1), the structural unit (Z2) and the structural unit (Z3) is 100% by mass. It is preferable that it is, and it is still more preferable that it is 15-100 mass%. When the proportion of the structural unit (Z1) contained in the second polymer is less than 10% by mass, the polymerization stability and light transmittance are inferior.

(Ii) (Z2) Polar functional group-containing monomer unit The polar functional group-containing monomer used to constitute the structural unit (Z2) is a monomer having a polar functional group in the molecule. . Preferred examples of this polar functional group include a carboxyl group, a cyano group, a hydroxyl group, an epoxy group, and an ester group. Specific examples of the polar functional group-containing monomer include those similar to the polar functional group-containing monomer used for constituting the structural unit (X2). Among them, ester group-containing monomers are preferable, and polyvalent (meta) such as (cyclo) alkyl (meth) acrylates such as methyl (meth) acrylate, diethylene glycol di (meth) acrylate, and trimethylolpropane tri (meth) acrylate. ) Acrylates are more preferred. These polar group-containing monomers can be used alone or in combination of two or more.

  The proportion of the structural unit (Z2) contained in the second polymer is 0 to 90% by mass when the total of the structural unit (Z1), the structural unit (Z2), and the structural unit (Z3) is 100% by mass. It is preferable that it is 0-85 mass%. If the proportion of the structural unit (Z1) contained in the second polymer exceeds 90% by mass, the polymerization stability and light transmittance are inferior.

(Iii) (Z3) Other monomer units The second polymer may contain monomer units composed of other monomers copolymerizable with the aforementioned various monomers, if necessary. It may be. Examples of the other monomer constituting the structural unit (Z3) include the same monomers as the other monomer that may be used to constitute the structural unit (X3).

  The proportion of the structural unit (Z3) contained in the second polymer is 0 to 10% by mass when the total of the structural unit (Z1), the structural unit (Z2) and the structural unit (Z3) is 100% by mass. It is preferable that it is 0-5 mass%. When the proportion of the structural unit (Z3) contained in the second polymer exceeds 10% by mass, the polymerization stability tends to decrease.

3) Organic irregular particles The organic irregular particles (A) of the present invention have (X) particles and (Z) particles. The (Z) particles are disposed on at least a part of the surface of the (X) particles. Here, “an irregular shape” in the present specification means that two particles are arranged asymmetrically with respect to the center point of the entire particle. In the case of particles having this asymmetry, even when the shape of the particles as a whole is spherical as shown in FIGS. 1 (b) to 1 (d), a rugby ball shape as shown in FIG. 1 (e), Even in the case of a twin sphere as shown in FIG. 1 (f) or a sphere having a spherical protrusion as shown in FIG. 1 (a), it is included in the concept of “organic deformed particles” in this specification. .

  Furthermore, as shown in FIG. 1 (g), when (X) the surface of the particle has at least one hemispherical protrusion composed of a part of the monomer component constituting the (Z) particle. Is also included in the concept of “organic irregular particles”.

  In the organic modified particles of the present invention, the composition of the first polymer and the composition of the second polymer may be the same or different, but the constitutional unit contained in the first polymer It is also preferable that at least one kind is different from the constituent monomer monomer unit contained in the second polymer. That is, in this case, at least one of the units constituting the organic modified particles is contained only in one of the first polymer and the second polymer. Thereby, for example, (X) primary particles and (Z) primary particles can be asymmetrically separated.

  The ratio of the number average value (L) of the major axis to the number average value (D) of the minor axis of the organic irregular shaped particles of the present invention is (L) / (D) = 1.0 to 2.0. Preferably, it is 1.1 to 1.9, more preferably 1.2 to 1.8. When the value of (L) / (D) is more than 2.0, dispersibility in the binder component is lowered, and it tends to be difficult to obtain a uniform light diffusion function.

  Here, “major axis” and “minor axis” in the case where the organic irregular shaped particles are spherical with spherical protrusions as shown in FIG. As shown in FIG. 2, the major axis (L) is represented by the distance from the end of the (X) particle 1 to the end of the (Z) particle 2. The short diameter (D) is represented by the diameter of the larger one of the particles ((X) particle 1 in FIG. 2).

  In the organic irregular shaped particles of the present invention, the ratio of the number average particle diameter (Lx) of (X) particles to the number average particle diameter (Lz) of (Z) particles is (Lx) / (Lz) = 0. It is preferably 05 to 20.0, more preferably 0.1 to 18, and particularly preferably 0.2 to 15. When the value of (Lx) / (Lz) is less than 0.05, the balance between light transmittance and light diffusibility tends to be remarkably inferior. On the other hand, even if the value of (Lx) / (Lz) is more than 20.0, the balance between light transmittance and light diffusibility tends to be extremely inferior. In addition, when the shape of the particle is not a true spherical shape but a so-called flat shape or the like, the average value of the major axis and the minor axis is defined as “average particle diameter”.

In the organic irregular shaped particles (A) of the present invention, the refractive index Rx of the (X) particle, the refractive index Rz of the (Z) particle, and the refractive index _RA having the larger refractive index, the binder polymer the difference in refractive index R _B of (B) is preferably 0.05 to 0.2. The difference in refractive index R _B and the refractive index R _A is less than 0.05, light diffusibility is insufficient, not obtained sufficient improvement of light extraction efficiency. On the other hand, the difference in refractive index R _B and the refractive index R _A is more than 0.2, too high light diffusibility is not preferable because the transmittance decreases remarkably.

  The organic modified particles of the present invention tend to maintain good polymerization stability when the first polymer and / or the second polymer has one or more reactive functional groups. Is preferred. Examples of the “reactive functional group” include an ester group, an amide group, an amine group, a carboxyl group, a sulfonic acid group, a sulfuric acid group, an epoxy group, and a hydroxyl group. As for the polymer having a reactive functional group, for an ester group, an amide group, an amine group, a carboxyl group, an epoxy group, and a hydroxyl group, for example, a monomer having these reactive functional groups is copolymerized, or It can be obtained by grafting a compound having these reactive functional groups. The polymer having a sulfonic acid group can be obtained, for example, by polymerizing a monomer in the presence of a reactive surfactant having a sulfonic acid group. Moreover, about the polymer which has a sulfate group, it can obtain by polymerizing a monomer using initiators, such as potassium persulfate, for example. The amount of the reactive functional group contained in the first polymer and / or the second polymer is 0.5 for each polymer in terms of the compound used for the introduction of the reactive functional group. It is preferable that it is -50 mass%, and it is still more preferable that it is 2-30 mass%.

4) Method for producing organic irregular particles The organic irregular particles of the present invention can be produced , for example, according to the methods described in JP-A-2007-197588 and WO2009 / 16765. First, the (X) particles comprising the first polymer can be obtained by a usual emulsion polymerization method using an aqueous medium.

The conditions for emulsion polymerization may be in accordance with known methods.
The polymerization conversion rate of the monomer at the end of the emulsion polymerization is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 95% by mass or more. When the monomer for the second polymer is added in a state where the polymerization addition rate of the first polymer is less than 80% by mass, the formed (X) particles and (Z) particles are difficult to clearly separate. Become. The (X) particles made of the first polymer obtained are usually spherical particles. (X) The number average particle diameter of the particles is preferably 0.1 to 9 μm, and more preferably 0.2 to 8 μm. (X) If the number average particle diameter of the particles is outside this range, it may be difficult to produce by emulsion polymerization.

  In the presence of the obtained (X) particles, the monomer for the second polymer is polymerized. More specifically, (Z) particles can be formed by seed polymerizing a monomer for the second polymer in a state where the obtained (X) particles are used as seed polymer particles.

(X) When the second polymer monomer is introduced into the aqueous medium in which the particles are dispersed, most of the second polymer monomer introduced as shown in FIG. Usually, (a) the particles are occluded once, and the polymerization starts in or on the surface of the (X) particles. As the polymerization proceeds, the compatibility of the second polymer monomer with the first polymer decreases, and the second polymer monomer phase separates from the first polymer. Therefore, at the initial stage of the polymerization, (a) the polymerization can proceed at a plurality of locations of the particles, but when the monomer units constituting each polymer satisfy the relationship described so far, the second polymer The (X) particles polymerized at various points tend to gather together to form a single (Z) particle (FIG. 3B). When the (Z) particles grow to a certain size, the subsequent polymerization proceeds mainly with the (Z) particles (FIG. 3 (c)). In this way, the organic irregular shaped particles of the present invention in which (X) particles and (Z) particles are separated asymmetrically are formed.

  The organic irregular shaped particles (A) of the present invention obtained as described above are aqueous emulsions containing polymer particles (A-1). The number average particle diameter of the polymer particles (A-1) is 0.8 to 10 μm, preferably 1.0 to 10 μm, and more preferably 1.2 to 10 μm. When the number average particle diameter is larger than 10 μm, it may be difficult to produce by an emulsion polymerization method. On the other hand, when it is smaller than 0.8 μm, the balance between light transmittance and light diffusibility is inferior, and sufficient light extraction efficiency cannot be improved. In addition, the “number average particle diameter” in the organic irregular shaped particles of the present embodiment refers to the length of passing in the longest direction of the organic irregular shaped particles, and can be measured by, for example, a light scattering method.

  In the organic modified particles of the present invention, the mass ratio ((X) / (Z)) of (X) particles to (Z) particles is preferably 2/98 to 98/2, and 5/95 to More preferably, it is 95/5. The ratio of the exposed surface formed by the (X) particles and the exposed surface formed by the (Z) particles (area ratio = (X) / (Z)) of the total surface area of the organic irregular particles is The ratio is preferably 5/95 to 95/5, and more preferably 10/90 to 90/10. When the proportion of either one of the (X) particles and the (Z) particles is less than the above range, the effect due to the fact that the organic modified particles are “modified” may not be sufficiently obtained. In addition, the ratio of the exposed surface of each primary particle which occupies for the total surface area of an organic deformed particle can be measured from an electron micrograph, for example.

  The shape of the organic irregular particles varies depending on the mass ratio of (X) particles and (Z) particles, the separability of (X) particles and (Z) particles, the polymerization conditions when forming (Z) particles, and the like. Change. For example, when the mass ratio of (X) particles to (Z) particles and the polymerization conditions are constant, the shape of the organic deformed particles is as shown in FIG. 1 as the separability between (X) particles and (Z) particles increases. It tends to change in the order of (b), FIG. 1 (d), and FIG. 1 (a).

<2. Binder polymer (B)>
The binder polymer (B) contained in the light extraction film of the present invention is transparent and can disperse and integrate the organic irregularly shaped particles (A) on the surface of a resin sheet, for example. For example, the type is not particularly limited. Specific examples of the binder polymer (B) include thermoplastic resins such as polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyvinyl butyral, poly (meth) acrylate, and nitrocellulose; phenol resins, melamine resins, polyester resins, A mixture containing a polyurethane resin, an epoxy resin, an organosilane, at least one selected from the organosilane hydrolyzate and the organosilane condensate, and a radically polymerizable (meth) acryl monomer in an emulsified state is hydrolyzed. Examples thereof include thermosetting resins such as siloxane-containing acrylic resins obtained by condensation reaction and radical polymerization. Among these, poly (meth) acrylic acid ester and siloxane-containing acrylic resin are preferable, and siloxane-containing acrylic resin is particularly preferable in terms of stain removability and weather resistance. These binder components can be used singly or in combination of two or more.

  The siloxane-containing acrylic resin is obtained by hydrolyzing, in an emulsified state, a mixture containing at least one selected from organosilane, the organosilane hydrolyzate and the organosilane condensate, and a radically polymerizable (meth) acrylic monomer. An organic-inorganic composite that can be obtained by condensation reaction and radical polymerization. The average particle diameter of the polymer particles (B-1) composed of the binder polymer (B) is usually 0.01 to 100 μm, preferably 0.05 to 10 μm. Moreover, the solid content concentration of the aqueous dispersion to be used is usually 10 to 60% by mass, preferably 20 to 50% by mass. In addition, although the aqueous medium in the binder polymer (B) of the present invention is essentially composed of water, an organic solvent such as alcohol may be contained up to several mass% depending on the case.

  In addition, the binder polymer (B) of this invention may be mix | blended with the silane coupling agent, and can be used as a binder of a light extraction film by mix | blending a silane coupling agent.

  The total light transmittance of the binder polymer (B) is preferably 80% or more, and more preferably 90% or more. If the total light transmittance of the binder component is less than 80%, the light extraction efficiency is lowered, which is not preferable. The “total light transmittance” referred to in this specification is a value measured based on JIS K7361-1.

  Commercially available products of the binder polymer (B) of the present invention can include, as siloxane-containing acrylic resins, siloxane-containing acrylic binder emulsion Glasca W3050 and Grasca W3010 manufactured by JSR, and poly (meth) acrylic acid ester resins made by Etec. And acrylic emulsions AE314A, AE373D, AE402A, and AE986B.

  The refractive index of the binder polymer (B) can be set so that the difference in refractive index from the transparent plastic film described later is 0.2 or less, preferably 0.15 or less, more preferably 0.1 or less. preferable. If the difference in refractive index between the transparent plastic film and the binder polymer (B) exceeds 0.2, the amount of incident light at a specific angle at the interface between the light diffusing layer and the transparent plastic film becomes too large, resulting in organic This is not preferable because the light extraction efficiency from EL illumination cannot be sufficiently improved.

  The content ratio of the organic irregular particles (A) and the binder polymer (B) constituting the light diffusion layer of the light extraction film of the present invention is 1 to 90% by mass of the organic irregular particles (A), and the binder polymer (B). It is preferably 10 to 99% by mass (however, (A) + (B) = 100% by mass), more preferably 3 to 80% by mass of the organic irregularly shaped particles (A), 20 to 20% of the binder polymer (B). 97% by mass. When the content ratio of the binder polymer (B) is less than 10% by mass, for example, it becomes difficult to disperse and integrate the organic irregularly shaped particles (A) on the surface of a transparent plastic film or the like. On the other hand, if the content of the binder polymer (B) exceeds 99% by mass, that is, if the content of the organic irregularly shaped particles (A) is less than 1% by mass, the light diffusibility becomes insufficient and sufficient light The improvement in the extraction efficiency cannot be obtained.

3. Sulfonated polymer (E)
The light diffusion layer constituting the light extraction film of the present invention preferably further contains a sulfonated polymer (E). By containing the sulfonated polymer, stability when the organic irregularly shaped particles (A) and the binder polymer (B) are blended is improved, and antistatic properties are imparted when the light diffusion layer is formed, and dust is added. The adhesion prevention property is significantly improved.

  Examples of the sulfonated polymer (E) include a sulfonated conjugated diene polymer (E-1) such as a sulfonated product of a conjugated diene polymer or a hydrogenated product of a conjugated diene polymer; an aromatic vinyl such as polystyrene. Examples thereof include sulfonated products of sulfonic acid polymers; sulfonated aromatic vinyl polymers such as homopolymers or copolymers of sulfonic acid group-containing monomers such as styrene sulfonic acid. Among these, at least one of the sulfonated conjugated diene polymer (E-1) and the polystyrene sulfonic acid (E-2) is preferable, and the sulfonated conjugated diene polymer (E-1) is particularly preferable.

  The sulfonated conjugated diene polymer (E-1) is a polymer containing a unit derived from a conjugated diene monomer or a hydrogenated product thereof (hereinafter, this polymer and the hydrogenated product are collectively referred to as “conjugated diene-based polymer”). Can be prepared by sulfonation, followed by treatment with water or a basic compound. Moreover, a commercial item can also be used as a sulfonated conjugated diene polymer (E-1).

1) Sulfonated conjugated diene polymer (E-1)
The sulfonated conjugated diene polymer (E-1) is obtained by converting a conjugated diene base polymer into a conventionally known method, for example, “New Experimental Chemistry Course” edited by The Chemical Society of Japan, Vol. 14 III, p. In accordance with the method described in 1773-1783 and the method described in JP-A-2-227403, the double bond portion of the conjugated diene unit in the conjugated diene base polymer is converted using a sulfonating agent. It can be prepared by sulfonation and then treatment with water or a basic compound.

  The sulfonic acid (salt) group content in the sulfonated conjugated diene polymer (E-1) is usually 0.1 to 6 mmol / g, preferably 0.5 to 5 mmol / g. If the sulfonic acid (salt) group content is less than 0.1 mmol / g, the antistatic ability may be insufficient. On the other hand, if it exceeds 6 mmol / g, the transparency of the light diffusion layer may be impaired.

The sulfonic acid (salt) group content of the sulfonated conjugated diene polymer (E-1) can be confirmed from absorption of the sulfone group by infrared absorption spectrum, and the composition ratio can be confirmed from elemental analysis or the like. The structure of the sulfonated conjugated diene polymer (E-1) can be confirmed from ¹ H-NMR analysis and ¹³ C-NMR analysis.

  The Mw of the sulfonated conjugated diene polymer (E-1) is preferably 1,000 or more, more preferably 5,000 or more, and particularly preferably 5,000 to 400,000. If the Mw is less than 1,000, the sulfonated conjugated diene polymer (E-1) may bleed out from the surface of the light diffusion layer, and the total light transmittance may decrease, which is not preferable. On the other hand, if it exceeds 400,000, the productivity may decrease. The sulfonated conjugated diene polymer (E-1) may be used alone or in combination of two or more.

<4. Other ingredients>
The composition for forming the light diffusing layer of the light extraction film of the present invention comprises, if desired, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polycarboxylic acid type polymer surfactant, Dispersants such as carboxylate, polyphosphate, polyacrylate, polyamide ester salt, polyethylene glycol; celluloses such as methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, castor oil derivatives, ferrosilicic acid In addition to a thickener such as a salt, other additives such as a surfactant, a silane coupling agent, and a titanium coupling agent can also be blended. In addition, as an ultraviolet absorber, inorganic semiconductors such as ZnO, TiO ₂ (not showing a photocatalytic function), CeO ₂ ; organic ultraviolet rays such as salicylic acid, benzophenone, benzotriazole, cyanoacrylate, and triazine As the absorber and ultraviolet stabilizer, an ultraviolet stabilizer such as a piperidine-based compound can be used.

  In addition, as a leveling agent for coating, for example, silicone-based, fluorine-based, fatty acid amide-based, acetylene glycol-based, and polyether-based compounds can be used. More specifically, “PSA336” (manufactured by Nissin Chemical Industry Co., Ltd.), “Envirogem AD-01” (manufactured by Air Product Japan Co., Ltd.), and “Surflon” Fluorine-based surfactants such as “S111N”, “Surflon S211” (manufactured by AGC Seimi Chemical Co., Ltd.), “Megafac F-812”, “F-833” (manufactured by DIC) can be mentioned. In addition, “trinone” (manufactured by Nippon Kasei Co., Ltd.) as the fatty acid amide wetting agent, acetylene glycol such as “Surfinol 104” as acetylene glycol wetting agent, “Surfinol 420”, “Surfinol 465” ( As mentioned above, an ethylene oxide adduct such as Air Product Japan Co., Ltd. can be mentioned. Furthermore, as a polyether-based wetting agent, “SN984”, “SN980” (manufactured by San Nopco), “KF-351”, “KF-352”, “KF-353”, “KF-615” (above, And polyether-based silicones such as “TSF-4442” and “TSF-4445” (manufactured by Toshiba Silicone Co., Ltd.).

  As the film-forming aid, one or more of alcohols, ethers and esters can be used. Examples include cellosolve, butyl cellosolve, 1,4-dioxane, diacetone alcohol, carbitol acetal, and the like, and commercially available butyl cellosolve, texanol and the like can be used as appropriate.

  In addition, you may blend other resin with the composition which forms the light-diffusion layer of the light extraction film of this invention. Examples of other resins include acrylic-urethane resins, epoxy resins, polyesters, acrylic resins, fluororesins, acrylic resin emulsions, epoxy resin emulsions, polyurethane emulsions, and polyester emulsions.

If desired, inorganic compound powders and / or sols or colloids may be blended. Specifically, TiO ₂ , TiO ₃ , SrTiO ₃ , FeTiO ₃ , WO ₃ , SnO ₂ , Bi ₂ O ₃ , In ₂ O ₃ , ZnO, Fe ₂ O ₃ , RuO ₂ , CdO, CdS, CdSe, GaP , GaAs, CdFeO ₃ , MoS ₂ , LaRhO ₃ , GaN, CdP, ZnS, ZnSe, ZnTe, Nb ₂ O ₅ , ZrO ₂ , InP, GaAsP, InGaAlP, AlGaAs, PbS, InAs, PbSe, InSb, etc. in addition to semiconductors _{with, SiO 2, Al 2 O 3} , AlGa, As, Al (OH) 3, Sb 2 O 5, Si 3 N 4, Sn-in 2 O 3, Sb-in 2 O 3, MgF, CeF ₃ , CeO ₂ , 3Al ₂ O ₃ .2SiO ₂ , BeO, SiC, AlN, Fe, Co, Co—FeOx, CrO ₂ , Fe 4 N, BaTiO ₃ , BaO—Al ₂ O ₃ —SiO ₂ , Ba ferrite, SmCO ₅ , YCO ₅ , CeCO ₅ PrCO ₅ , Sm ₂ CO ₁₇ , Nd ₂ Fe ₁₄ B, Al ₄ O ₃ , α-Si, SiN ₄ , CoO, Sb—SnO ₂ , Sb ₂ O ₅ , MnO ₂ , MnB, Co ₃ O ₄ , Co ₃ B, LiTaO ₃ , MgO, MgAl ₂ O ₄ , BeAl ₂ O ₄ , ZrSiO ₄ , ZnSb, PbTe, GeSi, FeSi ₂ , CrSi ₂ , CoSi ₂ , MnSi _1.73 , Mg ₂ Si, β-B, BaC, BP, TiB ₂ , ZrB ₂ , HfB ₂ , Ru ₂ Si ₃ , TiO ₂ (rutile type), TiO ₃ , PbTiO ₃ , Al ₂ TiO ₅ , Zn _{2 SiO 4, Zr 2 SiO 4} , 2MgO 2 -Al 2 O 3 -5SiO 2, Nb 2 O 5, Li 2 O-Al 2 O 3 -4SiO 2, Mg ferrite, Ni ferrite, Ni-Zn ferrite , Li ferrite, Sr ferrite and the like. These inorganic compounds can be used alone or in admixture of two or more.

  The inorganic compound is present in the form of a powder, an aqueous sol or colloid dispersed in water, a polar solvent such as isopropyl alcohol, or a solvent sol or colloid dispersed in a nonpolar solvent such as toluene. The average particle diameter is usually about 0.001 to 100 μm. In the case of a solvent-based sol or colloid, depending on the dispersibility of the semiconductor, it may be further diluted with water or a solvent, or may be used after a surface treatment to improve the dispersibility.

  The content of the other components is preferably 0 to 50% by mass, and preferably 0 to 40% by mass with respect to the organic irregularly shaped particles (A) + binder polymer (B) = 100% by mass. More preferably, it is especially preferable that it is 0-30 mass%. When the content ratio of the other components exceeds 50% by mass, the other components bleed out from the surface of the light diffusion layer, and the light extraction efficiency from the organic EL illumination may decrease with time, which is not preferable.

<5. Transparent plastic film>
The light extraction film of the present invention is a film having a light diffusion layer on at least one surface of a transparent plastic film. Examples of the transparent plastic film on which the light diffusion layer of the present invention can be disposed include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene-2,6-naphthalate (PEN); nylon 6, nylon 6 Polyamide such as polyethylene (PE) and polypropylene (PP); Polyacrylic such as polycarbonate (PC) and polymethyl methacrylate (PMMA); ABS resin, AES resin, polychlorinated biphenyl, polyvinyl alcohol, polyurethane And plastic molded products such as polyimide resins, polytetrafluoroethylene (PTFE), and fluorine resins such as ethylenetetrafluoroethylene (ETFE) and plastic films. Of these, polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) films are preferably used.

  The transparent plastic film used in the present invention can be used without particular limitation as long as it is a transparent (colorless transparent, colored transparent, translucent) film, and the binder polymer (B) constituting the light diffusion layer. It is preferable to appropriately select the composition of the binder polymer (B) and the transparent plastic film so that the difference in the refractive index of the binder polymer is 0.2 or less, preferably 0.15 or less, and more preferably 0.1 or less. If the difference in refractive index between the transparent plastic film and the binder polymer (B) exceeds 0.2, the amount of incident light at a specific angle at the interface between the light diffusing layer and the transparent plastic film becomes too large, resulting in organic This is not preferable because the light extraction efficiency from EL illumination cannot be sufficiently improved.

  Although the thickness of a transparent plastic film is not specifically limited, The thing of about 25-300 micrometers is preferably used at the point of the ease of handling of a film, and the ease of arrangement | positioning to organic EL illumination using a flexible substrate.

  These transparent plastic films can be surface-treated in advance for the purpose of improving adhesion. Examples thereof include blast treatment, chemical treatment, degreasing, flame treatment, oxidation treatment, steam treatment, corona discharge treatment, ultraviolet irradiation treatment, plasma treatment, ion treatment and the like.

  If necessary, for example, antifouling coating, hard coating, antistatic coating or the like can be performed on the opposite side of the transparent plastic film from the light diffusion layer with an arbitrary composition. Furthermore, surface microfabrication such as prism, microlens or pyramid shape can also be performed, and a plastic film which has been previously microfabricated such as prism, microlens or pyramid shape is used as the transparent plastic film of the present invention. You can also

  Usually, an adhesive layer is formed between the organic EL lighting and the transparent plastic film for bonding with the organic EL lighting. The pressure-sensitive adhesive layer is not particularly limited, but a re-peelable pressure-sensitive adhesive layer is preferably used so that re-bonding can be performed when the organic EL lighting and the light extraction film are bonded. The adhesive layer can also contain light diffusing particles such as organic irregular particles used in the present invention.

<6. Manufacturing method of light extraction film>
The manufacturing method of the light extraction film of this invention has the light-diffusion layer formed with the composition containing the above-mentioned organic type irregular-shaped particle (A) and binder polymer (B) on the at least one surface of a transparent plastic film. A method for producing a light extraction film, wherein the light diffusion layer comprises (X) particles made of a first polymer, and a second polymer disposed on at least a part of the surface of the (X) particles. An aqueous emulsion containing polymer particles (A-1) comprising organic deformed particles (A) having (Z) particles, and an aqueous emulsion comprising polymer particles (B-1) comprising binder polymer (B). A method for producing a light extraction film, characterized in that the light extraction film is formed from an aqueous emulsion composition. Details will be described below.

  In the light extraction film of the present invention, for example, the organic irregularly shaped particles (A) and the binder polymer (B) are dispersed or dissolved in a solvent capable of dispersing or dissolving them, and coating with various coaters and drying are performed. Can be manufactured. Specific examples of the solvent include water, toluene, cyclohexane, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), N-methyl-2-pyrrolidone (NMP) and the like.

  Among these, water is preferably used as a solvent, and an aqueous emulsion containing polymer particles (A-1) made of organic irregularly shaped particles (A) produced in an aqueous emulsion state, and polymer particles made of binder polymer (B) It is preferably formed by an aqueous emulsion composition having an aqueous emulsion containing (B-1). By mixing and stirring in the aqueous emulsion state, the polymer particles (A-1) composed of the organic irregularly shaped particles (A) and the polymer particles (B-1) composed of the binder polymer (B) are dispersed at the particle level. Therefore, any polymer particles are not partially aggregated, and the light extraction efficiency can be remarkably improved. In addition, since each produced aqueous emulsion is simply mixed and stirred, there is an advantage that a film product can be produced at low cost without the need for special powdering equipment and dispersion blending equipment.

  In order to apply the composition containing the organic irregularly shaped particles (A) and the binder polymer (B) on the transparent plastic film, various coating apparatuses can be used. Specific examples of the coating apparatus include a comma coater, a reverse coater, a slot die coater, a lip coater, a gravure chamber coater, and a curtain coater.

  When the composition containing the organic modified particles (A) and the binder polymer (B) coated on the transparent plastic film is dried and cured, it is preferably dried and cured in an atmosphere of 50 to 120 ° C. If it is less than 50 ° C., it is difficult to dry or harden, and therefore it tends to take a long time to form the light diffusion layer. On the other hand, when it exceeds 120 ° C., the transparent plastic film tends to be thermally deteriorated.

Although the film thickness after drying of a light-diffusion layer can be adjusted suitably, it is not specifically limited, Usually, it is 3-100 micrometers, Preferably it is 5-50 micrometers.
In the light diffusion layer described above, the organic irregular particles (A) are integrated on the transparent plastic film by the binder polymer (B). In addition, some organic system irregular-shaped particles (A) may be in the state which made the one part protrude from the surface of a binder polymer (B). Further, the protruding portion of the organic irregularly shaped particles (A) may be entirely covered with the binder polymer (B) or may be only partially covered. Note that all of the organic irregular particles (A) may be completely buried in the binder component.

  The total light transmittance of the light extraction film of the present invention is preferably 50% or more, and more preferably 60% or more. When the total light transmittance is less than 50%, the light transmittance is inferior, and the light extraction efficiency is hardly improved. Further, the haze of the light extraction film of this embodiment is preferably 60% or more, and more preferably 70% or more. When the haze is less than 60%, the light diffusibility is inferior, and the light extraction efficiency is hardly improved.

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. In addition, a method for measuring various physical property values and a method for evaluating various properties are shown below.

[Number average particle size]: Measured using a laser particle size analysis system (trade name “LS13320”, manufactured by Beckman Coulter, Inc.).
[Number average value of major axis (L) and number average value of minor axis (D)]: Measured by observation using SEM (scanning electron microscope).
[Total light transmittance]: Measured using a haze meter manufactured by Suga Test Instruments Co., Ltd. according to JIS K7361-1, assuming that the state without sample (air) was 100%.
[Haze]: Measured according to JIS K7136 using a haze meter manufactured by Suga Test Instruments Co., Ltd.

[Integrated intensity]: A 3 mm thick Mitsubishi Rayon milk white plate is installed in a light source device in which a plurality of LED light sources are arranged, and a uniform surface light source and a commercially available half mirror (aluminum vapor deposition) film (transmittance 20%, The reflectance 55%) was bonded in this order to obtain a simple organic EL light source device. The test light extraction film was bonded to the half mirror surface of a simple organic EL light source device using Nikon immersion oil (refractive index = 1.515), and the angular distribution of luminance was measured using EZContrast XL88 manufactured by ELDIM. Thus, the integrated intensity of light emission was obtained.

[Stain removal property]: A test light extraction film was marked with an aqueous pen, dried, then washed with water, the surface was wiped with a cloth, the pen marks were visually observed and evaluated according to the following criteria: .
◎ (Pass): Pen marks are completely wiped off ○ (Pass): Pen marks remain about 20% of the marking area

[Dust adhesion preventing property] In an environment of a temperature of 23 ° C. and a humidity of 55% RH, the light diffusion layer surface of the test light diffusion film was rubbed and charged at a constant load and a constant speed using BEMCOT M3 manufactured by Asahi Kasei. Next, it was brought close to a commercially available powder toner, and the adhesion of the toner to the surface of the light diffusion layer was visually confirmed and evaluated according to the following criteria.
◎ (Pass): Powder toner does not adhere at all ○ (Pass): Powder toner adheres about 20% of the sample area

1. Synthesis of polymer particles (A) (Synthesis Example 1)
Stir 2 parts of 3,5,5-trimethylhexanoyl peroxyside (trade name “Perroyl 355”, manufactured by NOF Corporation, water solubility: 0.01%), 0.1 part of sodium lauryl sulfate, and 20 parts of water. After emulsification, the mixture was further microparticulated with an ultrasonic homogenizer to obtain an aqueous dispersion. To the obtained aqueous dispersion, 11 parts of monodispersed polystyrene particles having a number average particle diameter of 1.0 μm were added and stirred for 16 hours. Next, 70 parts of styrene (ST), 20 parts of divinylbenzene (DVB), and 10 parts of glycidyl methacrylate (GMA) are added, and the mixture is slowly stirred at 40 ° C. for 3 hours, and the monomer components (ST, DVB, and GMA) are simply added. Absorbed in dispersed polystyrene particles. Then, it heated up at 75 degreeC and performed the polymerization reaction for 3 hours, and the emulsion containing the (X) particle | grains which consist of a 1st polymer was obtained. The number average particle diameter of the (X) particles was 2.1 μm, and almost no coagulum was generated.

  22.1 parts of the same aqueous dispersion as the above-mentioned aqueous dispersion and 10 parts of an emulsion containing the above-mentioned (X) particles (but as a solid content) were mixed and stirred for 16 hours. Next, 90 parts of styrene (ST) and 20 parts of divinylbenzene (DVB) were added, and the mixture was slowly stirred at 40 ° C. for 3 hours to absorb the monomer components (ST and DVB) in the (X) particles. Thereafter, the temperature is raised to 75 ° C. and a polymerization reaction is carried out for 3 hours to form (Z) particles composed of the second polymer, and polymer particles composed of (X) particles and (Z) particles (polymer (A An aqueous emulsion containing)) was obtained. The shape of the polymer particles is a Dharma-shaped irregular shape particle as shown in FIG. 1 (a). The particle size of (Z) particles is 4.0 μm, the number average particle size of polymer particles is 4.5 μm, (L) The / (D) ratio was 1.3, and Lx (μm) / Lz (μm) = 2.1 / 4.0, and almost no coagulum was generated.

(Synthesis Examples 2-5, Comparative Synthesis Examples 1-4)
Except for the formulation of the first polymer and the second polymer as shown in Table 1 (however, in Comparative Synthesis Examples 1 to 4, the second polymer is not formed) In the same manner as in Synthesis Example 1, aqueous emulsions each containing polymer particles (polymers (B) to (I)) were obtained. As for the shape of the polymer particles, the polymers (B) and (C) are dharma-shaped irregular particles similar to the polymer (A), and the polymers (D) and (E) are as shown in FIG. On the surface of the (X) particles, Dharma-shaped irregularly shaped particles in which a plurality of hemispherical protrusions composed of a part of the monomer component constituting the (Z) particles were arranged. Various physical property values are shown in Table 1.

2. Synthesis of sulfonated conjugated diene polymer (E-1) (Synthesis Example 6)
Into a glass reaction vessel, 100 g of dioxane was added, 15.7 g of anhydrous sulfuric acid was added while maintaining the internal temperature at 25 ° C., and then stirred for 1 hour to obtain an anhydrous sulfuric acid-dioxane complex. Next, a 15% concentration solution of 100 g of isoprene / styrene binary block copolymer (isoprene / styrene weight ratio = 60/40, weight average molecular weight = 10,000) dissolved in dioxane, and the internal temperature at 25 ° C. While maintaining the total amount of the complex, the solution was stirred for 1 hour to prepare a polymer solution (1). Separately, 1200 g of water and 7.9 g of sodium hydroxide were put in a flask, the internal temperature was heated to 40 ° C., and the whole amount of the polymer solution (1) was added dropwise in 10 minutes while maintaining the same temperature. . After completion of the dropwise addition, the mixture was stirred for 2 hours while maintaining the same temperature, and then the solvent was completely removed by distillation under reduced pressure to give a sulfonated conjugated diene polymer (E-1) in which the isoprene unit was sulfonated (solid content concentration). Synthesized as a 15% aqueous solution. In addition, the sulfonate group content of the sulfonated conjugated diene polymer (E-1) was 1.7 mmol / g, and the weight average molecular weight (Mw) was 20,000.

3. Preparation of polymer composition and preparation of test light extraction film (Example 1)
A JSR siloxane-containing acrylic binder (Glaska W3050) emulsion (solid content 41%) is used as the binder polymer (B), and the aqueous system containing the polymer (A) with respect to 60 parts of the binder emulsion (but as solid content). 40 parts of the emulsion was added and stirred thoroughly. Subsequently, 5 parts of butyl cellosolve (film forming aid) and 0.2 part of Surflon S211 (wetting agent) manufactured by AGC Seimi Chemical were further added to obtain an aqueous emulsion composition.

Subsequently, the obtained aqueous emulsion composition was coated on a transparent plastic film (total light transmittance: 92.5%, haze: 1.2%, thickness: 125 μm) made of polymethyl methacrylate (PMMA). Then, it was dried and cured at 80 ° C. for 3 minutes to obtain a light extraction film (Example 1) having a light diffusion layer having a thickness of 20 μm. The obtained light extraction film has a total light transmittance of 79.9%, a haze of 99.2%, an integrated strength of 2970 lm / m ² , a stain removal property of “◎ (pass)”, and a dust adhesion prevention property. Was "○ (pass)". The evaluation results are shown in Table 2 below.

(Examples 2-8, Comparative Examples 1-7)
An aqueous emulsion composition was obtained in the same manner as in Example 1 except that the formulation shown in Table 2 was used. Moreover, using the obtained water-based emulsion composition, it carried out similarly to the case of the above-mentioned Example 1, and obtained the light extraction film (Examples 2-8, Comparative Examples 1-7). Table 2 shows the thickness of the light diffusion layer, total light transmittance, haze, integrated strength, dirt removing property and dust adhesion preventing property of the obtained light extraction film.

Example 9
An aqueous emulsion composition was obtained in the same manner as in Example 1 except that Etec acrylic emulsion (AE986B) and polymer (E) containing no siloxane component were used as the binder polymer. Further, using the obtained aqueous emulsion composition, a light extraction film (Example 9) was obtained in the same manner as in Example 1 described above. Table 2 shows the thickness of the light diffusion layer, total light transmittance, haze, integrated strength, dirt removing property and dust adhesion preventing property of the obtained light extraction film.

(Example 10)
An aqueous emulsion composition was obtained in the same manner as in Example 6 except that 5 parts of the sulfonated conjugated diene polymer obtained in Synthesis Example 6 was used. Further, using the obtained aqueous emulsion composition, a light extraction film (Example 10) was obtained in the same manner as in Example 1 described above. Table 2 shows the thickness of the light diffusion layer, total light transmittance, haze, integrated strength, dirt removing property and dust adhesion preventing property of the obtained light extraction film.

(Example 11)
The same as in Example 6 above, except that a polyethylene terephthalate (PET) film (total light transmittance: 92.4%, haze: 2.5%, thickness: 125 μm) was used as the transparent plastic film. Thus, an aqueous emulsion composition was obtained. Moreover, using the obtained aqueous emulsion composition, a light extraction film (Example 16) was obtained in the same manner as in Example 6 described above. Table 2 shows the thickness of the light diffusion layer, total light transmittance, haze, integrated strength, dirt removing property and dust adhesion preventing property of the obtained light extraction film.

(Example 12)
The water-based emulsion containing the polymer (A) was dried using a spray dryer (model number “L-8 type”, manufactured by Okawara Chemical Co., Ltd.) to obtain a powdery polymer (A). 40 parts of the above-mentioned powdery polymer (A) with respect to a mixed liquid obtained by mixing 60 parts of Kuraray polymethyl methacrylate resin (parapet HR-L) and 200 parts of methyl isobutyl ketone (MIBK) Was added and dispersed to obtain a polymer composition. Next, the obtained polymer composition was coated on the same transparent plastic film made of PMMA as in Example 6 described above, and dried at 60 ° C. for 3 hours, whereby light having a light diffusion layer having a thickness of 20 μm was obtained. A take-out film (Comparative Example 16) was obtained. Table 2 shows the thickness of the light diffusion layer, total light transmittance, haze, integrated strength, dirt removing property and dust adhesion preventing property of the obtained light extraction film.

４．考察
表２に示すように、合成例１〜５のポリマー粒子を用いて作製した実施例１〜１２の光取り出しフィルムは、比較合成例１〜４のポリマー粒子を用いて作製した比較例１〜７の光取り出しフィルムと比べて、光取り出し効率の指標である積算強度の値が高いことが明らかである。

4). Discussion As shown in Table 2, the light extraction films of Examples 1 to 12 prepared using the polymer particles of Synthesis Examples 1 to 5 are Comparative Examples 1 to 1 prepared using the polymer particles of Comparative Synthesis Examples 1 to 4. It is clear that the integrated intensity value, which is an index of the light extraction efficiency, is higher than the light extraction film of No. 7.

  In addition, the light extraction films of Comparative Examples 7 to 13 were prepared using spherical particles alone or compositions obtained by simply blending two kinds of spherical particles. Thus, it is clear that it is difficult to improve the light extraction efficiency simply by blending spherical particles without using irregularly shaped particles.

  According to the light extraction film of the present invention, the utilization efficiency of the light emitted from the organic EL layer can be remarkably enhanced, and the brightness and durability of the film, and the adhesion prevention and removal properties such as dust and dirt can be improved.

1 (X) Particle 2 (Z) Particle 5 Organic deformed particle D Minor axis L Major axis

Claims (15)

  Organic modified particles (A) having (X) particles made of the first polymer and (Z) particles made of the second polymer disposed on at least a part of the surface of the (X) particles ) And a binder polymer (B).   2. The light extraction film according to claim 1, wherein a number average particle diameter of the organic irregular particles (A) is 0.8 to 10 μm.   The ratio of the number average particle diameter (Lx) of the (X) particles to the number average particle diameter (Lz) of the (Z) particles in the organic modified particles (A) is (Lx) / (Lz) = 0. The light extraction film according to claim 1, wherein the light extraction film is from 0.05 to 20.   At least one hemispherical protrusion composed of a part of the monomer component constituting the (Z) particle is arranged on the surface of the (X) particle in the organic irregular particle (A). The light extraction film according to claim 1, wherein the light extraction film is a film.   The light extraction film according to any one of claims 1 to 4, wherein the binder polymer (B) is a siloxane-containing acrylic resin.   The content of the organic irregularly shaped particles (A) and the binder polymer (B) is 1 to 90% by mass of the organic irregularly shaped particles (A) and 10 to 99% by mass of the binder polymer (B) (however, (A) + The light extraction film according to claim 1, wherein (B) = 100% by mass).   Of the refractive index Rx of the (X) particles in the organic fine particles (A) and the refractive index Rz of the (Z) particles, the higher refractive index RA, and the binder polymer (B) The light extraction film according to claim 1, wherein the difference in refractive index RB is 0.05 to 0.2.   The light extraction film according to claim 1, wherein the total light transmittance is 50% or more and the haze is 60% or more.   The light extraction film according to claim 1, further comprising a sulfonated polymer (E).   The light extraction film according to claim 9, wherein the sulfonated polymer (E) is at least one of a sulfonated conjugated diene polymer (E-1) and a polystyrene sulfonic acid (E-2).   An aqueous emulsion in which the light extraction film includes an aqueous emulsion containing polymer particles (A-1) made of organic irregularly shaped particles (A) and an aqueous emulsion containing polymer particles (B-1) made of a binder polymer (B). It forms with the composition, The light extraction film in any one of Claims 1-10 characterized by the above-mentioned.   The light extraction film according to claim 1, wherein a light diffusion layer containing the organic irregularly shaped particles (A) and the binder polymer (B) is formed on a transparent plastic film. .   It is an object for organic EL illumination, The light extraction film in any one of Claims 1-12 characterized by the above-mentioned.   An organic EL illumination comprising the light extraction film for organic EL illumination according to claim 13.   A method for producing a light extraction film obtained by a composition comprising the above-mentioned organic irregularly shaped particles (A) and a binder polymer (B), comprising: (X) particles comprising a first polymer; An aqueous emulsion comprising polymer particles (A-1) consisting of organic irregularly shaped particles (A) having (Z) particles consisting of a second polymer and disposed on at least a part of the surface; and a binder polymer ( A method for producing a light extraction film, comprising: an aqueous emulsion composition having an aqueous emulsion comprising polymer particles (B-1) comprising B).

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