WO2019020598A2

WO2019020598A2 - Composition

Info

Publication number: WO2019020598A2
Application number: PCT/EP2018/069982
Authority: WO
Inventors: Hiroshi Okura; Stephan Dertinger; Ryuta Suzuki; Kazuhisa AZUMA; Eiji Nishihara; Tadashi Ishigaki; Koutoku Ohmi
Original assignee: Merck Patent Gmbh
Priority date: 2017-07-26
Filing date: 2018-07-24
Publication date: 2019-01-31
Also published as: AR112230A1; AR112231A1; WO2019020598A3

Abstract

The present invention relates to a composition, a formulation, an optical medium, use, an optical device, a method for manufacturing thereof.

Description

Composition

Field of the Invention

Background Art

JP 2007-135583 A mentions an organic dye having a peak wavelength at 613 nm and suggestion to use it with a thermoplastic resin as an agriculture film.

A polypropylene film containing an organic dye with peak light emission wavelength at 592 nm is disclosed in WO 1993/009664 A1 . JP H09-249773 A mentions an organic dye having peak light wavelength at 592 nm and a suggestion to use it with a polyolefin resin as an agriculture film.

A combination of an ultraviolet light emitting diode, blue, red, yellow light emitting diodes for green house light source is disclosed in JP 2001 -28947 A.

JP 2004-1 13160 A discloses a plant growth kit with a light emitting diode light source containing blue and red light emitting diodes.

(Ba,Ca,Sr)₃MgSi₂O8:Eu²⁺, Mn²⁺ phosphors such as

(Bao.97Euo.o3)3(Mgo.95Mno.o5)Si₂O8, (Bao.735 Sro.zssEuo.osMMgo.gsMno.os) Si₂O₈ with a peak light emission wavelength around 625 nm, and a suggestion to use it as an agricultural lamp is described on Han et al., Journal of luminescence (2014), vol. 148, p1 -5. Patent Literature

1 . JP 2007-135583A

2. WO 1993/009664 A1

3. JP H09-249773A

4. JP 2001 -28947A

5. JP 2004-1 13160A

Non- Patent Literature

6. "Analysis of (Ba,Ca,Sr)₃MgSi₂O8:Eu²⁺, Mn²⁺ phosphors for application in solid state lighting", Han et al., Journal of luminescence (2014), vol. 148, p1 -5

Summary of the invention

The inventors surprisingly have found that there is still one or more considerable problems for which improvement are desired, as listed below.

1 . A novel composition suitable for fabricating an optical medium such as a color conversion sheet, which shows better UV stability, improved color fastness and color stability on color less, and less concentration

quenching of a fluorescent materials, is desired.

2. A novel composition suitable for fabricating an optical medium such as a color conversion sheet, and / or an optical device comprising a

fluorescent material and matrix material which shows better plant growth ability, is required.

3. A novel composition suitable for fabricating an optical medium such as a color conversion sheet, and / or an optical device comprising a

fluorescent material and matrix material, in which can absorb UV and / or purple light (430 nm or shorter wavelength) to keep off harmful insects from plants, is desired. 4. A novel composition suitable for fabricating an optical medium such as a color conversion sheet, and / or an optical device comprising a fluorescent material and matrix material, in which can pass through blue light, is requested.

Then, it is found that a novel composition comprising, essentially consisting of, or a consisting of at least one inorganic fluorescent material having a peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, preferably it is from 660 nm to 710 nm, and / or an inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm, preferably the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, and a matrix material.

In another aspect, the invention relates to a formulation comprising, essentially consisting of, or a consisting of the composition and a solvent.

In another aspect, the invention relates to an optical medium (100) comprising the composition. In another aspect, the invention relates to an optical device (300) comprising the optical medium (301 ). In another aspect, the invention relates to use of the composition, or the formulation in an optical medium fabrication process.

In another aspect, the invention relates to use of the optical medium (100) in an optical device or for agriculture.

In another aspect, the invention further relates to use of an inorganic fluorescent material having the peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, and / or at least one inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm, preferably the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, with a matrix material in an optical medium (200).

In another aspect, the present invention furthermore relates to method for preparing the optical medium (100), wherein the method comprises following steps (a) and (b) in this sequence; (a) providing the composition or the formulation according to claim 8 onto a substrate or into an inflation moulding machine, and (b) fixing the matrix material by evaporating a solvent and / or polymerizing the composition by heat treatment, or exposing the photosensitive composition under ray of light or a combination of any of these.

In another aspect, the present invention furthermore relates to method for preparing the optical device (200), wherein the method comprises following step (A),

(A) providing the optical medium (100) in an optical device (200). Further advantages of the present invention will become evident from the following detailed description.

Description of drawings Fig. 1 : shows a cross sectional view of a schematic of one embodiment of an optical medium (100) of the invention.

Fig. 2: shows a cross sectional view of a schematic of one embodiment of an optical device (200) of the invention.

Fig. 3: shows a cross sectional view of a schematic of another embodiment of an optical device (200) of the invention.

List of reference signs in figure 1

100. an optical medium (a color conversion sheet)

1 10. an inorganic fluorescent material of the invention 120. a matrix material

130. an another type of inorganic fluorescent material (optional)

List of reference signs in figure 2

200. an optical device (a light emitting diode device)

210. an inorganic fluorescent material of the invention

220. a matrix material

230. a light emitting diode element

240. conductive wires

250. a molding Material

260a. a cup

260b. a mount lead

270. an inner lead

List of reference signs in figure 3

300. a light emitting diode device

301 . a color conversion sheet

310. an inorganic fluorescent material of the invention

320. a matrix material

330. a light emitting diode element

340. an another type of inorganic fluorescent material (optional)

350. a casing

360. converted light

370. emitted light

Detailed Description of the invention -Composition

According to the present invention, said composition comprises, essentially consists of, or a consists of at least one inorganic fluorescent material having a peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, preferably it is from 660 nm to 710 nm, and / or at least one inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm, preferably the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, and a matrix material.

Preferably, the composition comprises a plurality of inorganic fluorescent materials having a peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, and / or a plurality of inorganic fluorescent materials having the first peak wavelength of light emitted from the inorganic fluorescent material and the second peak wavelength of light emitted from the inorganic fluorescent material.

- Inorganic fluorescent materials

According to the present invention, any type of publically known inorganic fluorescent materials having a peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, or an inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm can be used preferably.

Preferably, the inorganic fluorescent material is selected from the group consisting of sulfides, thiogallates, nitrides, oxy-nitrides, silicates, metal oxides, apatites, phosphates, selenides, botates, carbon materials, and a combination of any of these.

For example, the inorganic fluorescent material is selected from the group consisting of AI₂O₃:Cr³⁺, Y₃AI₅Oi₂:Cr³⁺, MgO:Cr³⁺, ZnGa₂O₄:Cr³⁺,

MgAI₂O₄:Cr³⁺,MgSr₃Si₂O₈:Eu²⁺,Mn²⁺, Sr₃MgSi₂O₈:Mn⁴⁺, Sr₂MgSi₂O₇:Mn⁴⁺, SrMgSi₂O₆:Mn⁴⁺, Mg₂SiO₄:Mn²⁺, BaMg₆Ti₆Oi9:Mn⁴⁺, Mg₂TiO₄:Mn⁴⁺,

Li₂TiO₃:Mn⁴⁺, CaAli₂Oi₉:Mn⁴⁺, ZnAI₂O₄:Mn²⁺, LiAIO₂:Fe³⁺, LiAI₅O₈:Fe³⁺, NaAISiO₄:Fe³⁺, MgO:Fe³⁺, Mg₈Ge₂OnF₂:Mn⁴⁺, CaGa₂S₄:Mn²⁺,

Gd₃Ga₅Oi₂:Cr³⁺, Gd₃Ga₅O12:Cr³⁺,Ce³⁺, (Ca, Ba, Sr)MgSi₂O₆:Eu,Mn, (Ca, Ba, Sr)₂MgSi₂O₇:Eu,Mn, (Ca, Ba, Sr)₃MgSi₂O₈:Eu,Mn, ZnS, InP/ZnS, CulnS₂, CulnSe₂, CulnS₂/ZnS, carbon/graphen quantum dot and a combination of any of these as described in the second chapter of Phosphor handbook (Yen, Shinoya, Yamamoto).

In some embodiments of the present invention, the inorganic fluorescent materials can emit a light having the peak wavelength of light emitted from the inorganic fluorescent material in the range from 660 nm to 710 nm.

It is believed that the peak maximum light wavelength of the light emitted from the phosphor in the rage 660 nm to 710 nm is specifically useful for plant growth. Without wishing to be bound by theory, it is believed that the inorganic fluorescent material having at least one light absorption peak wavelength in UV and / or purple light wavelength region from 300 nm to 430 nm may keep harmful insects off plants.

Therefore, in some embodiments of the present invention, the inorganic fluorescent material can have at least one light absorption peak wavelength in UV and / or purple light wavelength reason from 300 nm to 430 nm.

In some embodiments of the present invention, from the viewpoint of improved plant growth and improved homoginiousity of blue and red (or infrared) light emission from the composition or from the light converting sheet, an inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from

400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm can be used preferably. More preferably, the inorganic fluorescent material having the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, is used.

Preferably, said at least one inorganic fluorescent material is a plurality of inorganic fluorescent material having the first and second peak

wavelength of light emitted from the inorganic fluorescent material, or a plurality of inorganic fluorescent material having the first and second peak wavelength of light emitted from the inorganic fluorescent material, or a combination of these. It is believed that the Mn⁴⁺ activated metal oxide phosphors, Mn, Eu activated metal oxide phosphors, Mn²⁺ activated metal oxide phosphors, Fe³⁺ activated metal oxide phosphors can be used preferably from the viewpoint of environmental friendly since these phosphors do not create Cr⁶⁺ during synthesis procedure.

Without wishing to be bound by theory, it is believed that the Mn⁴⁺ activated metal oxide phosphors are very useful for plant growth, since it shows narrow full width at half maximum (hereafter "FWHM") of the light emission, and also have the peak absorption wavelength in UV and green wavelength region such as 350 nm and 520 nm, and the emission peak wavelength is in near infrared ray region such as from 650 nm to 730 nm. More preferably, it is from 670 nm to 710 nm.

In other words, without wishing to be bound by theory, it is believed that the Mn⁴⁺ activated metal oxide phosphors can absorb the specific UV light which attracts insects, and also green light which does not give any advantage for plant growth, and can convert the absorbed light to longer wavelength in the range from 650 nm to 730 nm, more preferably from 670 nm to 710 nm, which can effectively accelerate plant growth.

From that point of view, even more preferably, the inorganic fluorescent material can be selected from Mn activated metal oxide phosphors.

In a further preferred embodiment of the present invention, the inorganic fluorescent material is selected from one or more of Mn activated metal oxide phosphors represented by following formulae (I) to (VI), A_xB_yO_z:Mn⁴⁺ - (I) wherein A is a divalent cation and is selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺, B is a tetravalent cation and is Ti³⁺, Zr³⁺ or a

combination of these; x≥1 ; y≥0; (x+2y) = z, preferably A is selected from one or more members of the group consisting of Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Zn²⁺, B is Ti³⁺, Zr³⁺ or a combination of Ti³⁺ and Zr³⁺, x is 2, y is 1 , z is 4, more preferably, formula (I) is Mg₂TiO₄:Mn⁴⁺;

XaZ_bO_c:Mn⁴⁺ - (II) wherein X is a monovalent cation and is selected from one or more members of the group consisting of Li⁺, Na⁺, K⁺, Ag⁺ and Cu⁺; Z is a tetravalent cation and is selected from the group consisting of Ti³⁺ and Zr³⁺; b≥0; a≥1 ; (0.5a+2b) = c, preferably X is Li⁺, Na⁺ or a combination of these, Z is Ti³⁺, Zr³⁺ or a combination of these a is 2, b is 1 , c is 3, more preferably formula (II) is Li₂TiO3:Mn⁴⁺;

D_dEeO_f:Mn⁴⁺ - (III) wherein D is a divalent cation and is selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺; E is a trivalent cation and is selected from the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; e≥10; d≥0; (d+1 .5e) = f, preferably D is Ca²⁺, Sr²⁺, Ba²⁺ or a combination of any of these, E is Al³⁺, Gd³⁺ or a combination of these, d is 1 , e is 12, f is 19, more preferably formula (III) is CaAli₂Oi₉:Mn⁴⁺;

DgE_hOi:Mn⁴⁺ - (IV) wherein D is a trivalent cation and is selected from one or more members of the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; E is a trivalent cation and is selected from the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; h≥0; a≥g; (1 .5g+1 .5h) = I, preferably D is La³⁺, E is Al³⁺, Gd³⁺ or a combination of these, g is 1 , h is 12, i is 19, more preferably formula (IV) is LaAIO₃:Mn⁴⁺;

GjJ_kLiO_m:Mn⁴⁺ - (V) wherein G is a divalent cation and is selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺; J is a trivalent cation and is selected from the group consisting of Y³⁺, Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; L is a trivalent cation and is selected from the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; l≥0; k≥0; j≥0; (j+1 .5k+1 .51) = m, preferably G is selected from Ca²⁺, Sr²⁺, Ba²⁺ or a combination of any of these, J is Y³⁺, Lu³⁺ or a combination of these, L is Al³⁺, Gd³⁺ or a combination of these, j is 1 , k is 1 , I is 1 , m is 4, more preferably it is CaYAIO₄:Mn⁴⁺; and

MnQoRpO_q:Eu,Mn - (VI) wherein M and Q are divalent cations and are, independently or

dependently of each other, selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺; R is Ge³⁺, Si³⁺, or a combination of these; n≥2; o≥0; p≥1 ; (n+o+2.0p) = q, preferably M is Ca²⁺, Sr²⁺, Ba²⁺ or a combination of any of these, Q is Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Zn²⁺ or a combination of any of these, R is Ge³⁺, Si³⁺, or a combination of these, n is 3, o is 1 , p is 2, q is 8, more preferably it is (Ca, Ba, Sr)₃MgSi2O₈:Eu, Mn. A Mn activated metal oxide phosphor represented chemical formula (VI) is more preferable since it emits a light with a first peak wavelength in the range from 400nm to 500nm and a second peak wavelength in the range from 600 nm to 750 nm, preferably the Mn activated metal oxide phosphor represented chemical formula (VI) emits light with the first peak

wavelength in the range from 430 nm to 490 nm, and the second peak wavelength in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm.

In some preferred embodiments of the present invention, the inorganic fluorescent material can be a Mn activated metal oxide phosphor selected from the group consisting of Mg₂TiO₄:Mn⁴⁺, Li₂TiO₃:Mn⁴⁺, CaA ₂Oi₉:Mn⁴⁺, LaAIO₃:Mn⁴⁺, CaYAIO₄:Mn⁴⁺, (Ca, Ba, Sr)₃MgSi₂O₈:Eu,Mn and a

combination of any of these.

In some embodiments of the present invention, the total amount of the phosphor of the composition is in the range from 0.01 wt.% to 30wt.% based on the total amount of the matrix material, preferably it is from

0.1 wt.% to 10wt.%, more preferably from 0.5wt.% to 5wt.%, furthermore preferably it is from 1wt.% to 3wt.% from the view point of better light conversion property, lower production cost and less production damage of a production machine.

--Matrix materials

According to the present invention, as the matrix material, a transparent photosetting polymer, a thermosetting polymer, a thermoplastic polymer, glass substrates or a combination of any of these, can be used preferably. As polymer materials, polyethylene, polypropylene, polystyrene, polymethylpentene, polybutene, butadiene styrene, polyvinyl chloride, polystyrene, polymethacrylic styrene, styrene-acrylonitrile, acrylonitrile- butadiene-styrene, polyethylene terephthalate, polymethyl methacrylate, polyphenylene ether, polyacrylonitrile, polyvinyl alcohol, acrylonitrile polycarbonate, polyvinylidene chloride, polycarbonate, polyamide, polyacetal, polybutylene terephthalate, polytetrafluoroethylene, ethyl vinylacetate copolymer, ethylene tetrafluorethylen copolymer, polyaminde, phenol, melamine, urea, urethane, epoxy, unsaturated polyester, polyallyl sulfone, polyarylate, hydroxybenzoic acid polyester, polyetherimide, polycyclohexylenedimethylene terephthalate, polyethylene naphthalate, polyester carbonate, polylactic acid, phenolic resin, silicone can be used preferably.

As the photosetting polymer, several kinds of (meth)acrylates can be used preferably. Such as unsubstituted alkyl-(meth)acrylates, for examples, methyl-acrylate, methyl-methacrylate, ethyl-acrylate, ethyl-methacrylate, butyl-acrylate, butyl-methacrylate, 2-ethylhexyl-acrylate, 2-ethylhexyl- methacrylate; substituted alkyl-(meth)acrylates, for examples, hydroxyl- group, epoxy group, or halogen substituted alkyl-(meth)acrylates;

cyclopentenyl(meth)acrylate, tetra-hydro furfuryl-(meth)acrylate, benzyl (meth)acrylate, polyethylene-glycol di-(meth)acrylates.

In view of better coating performance of the composition, sheet strength, and good handling, the matrix material has a weight average molecular weight in the range from 5,000 to 50,000 preferably, more preferably from 10,000 to 30,000.

According to the present invention, the molecular weight Mw is determined by means of GPC (= gel permeation chromatography) against an internal polystyrene standard. As the thermosetting polymer, publically known transparent thermosetting polymer can be used preferably. Such as OE6550 series (Dow Corning).

As the thermoplastic polymer, the type of thermoplastic polymer is not particularly limited. For example, natural rubber(refractive index(n)=1 .52), poly-isoprene(n=1 .52), poly 1 ,2-butadine(n=1 .50), polyisobutene(n=1 .51 ), polybutene(n=1 .51 ), poly-2-heptyl 1 ,3-butadine(n=1 .50), poly-2-t-butyl-1 ,3- butadine(n=1 .51 ), poly-1 ,3-butadine(n=1 .52), polyoxyethylene(n=1 .46), polyoxypropylene(n=1 .45), polyvinylethyl ether(n=1 .45),

polyvinylhexylether(n=1 .46), polyvinylbutylether(n=1 .46), polyethers, poly vinyl acetate(n=1 .47), poly esters, such as poly vinyl propionate(n=1 .47), poly urethane(n=1 .5 to 1 .6), ethyl celullose(n=1 .48), poly vinyl

chloride(n=1 .54 to 1 .55), poly acrylo nitrile(n=1 .52), poly

methacrylonitrile(n=1 .52), poly-sulfone(n=1 .63), poly sulfide(n=1 .60), phenoxy resin(n=1 .5 to 1 .6), polyethylacrylate(n=1 .47), poly butyl acrylate(n=1 .47), poly-2-ethylhexyl acrylate(n=1 .46), poly-t-butyl acrylate(n=1 .46), poly-3-ethoxypropylacrylate(n=1 .47), polyoxycarbonyl tetra-methacrylate(n=1 .47), polymethylacrylate(n=1 .47 to 1 .48),

polyisopropylmethacrylate(n=1 .47), polydodecyl methacrylate(n=1 .47), polytetradecyl methacrylate(n=1 .47), poly-n-propyl methacrylate(n=1 .48), poly-3,3,5-trimethylcyclohexyl methacrylate(n=1 .48),

polyethylmethacrylate(n=1 .49), poly-2-nitro-2- methylpropylmethacrylate(n=1 .49), poly-1 ,1 -diethylpropylmethacrylate (n=1 .49), poly(meth)acrylates, such as polymethylmethacrylate(n=1 .49), or a combination of any of these, can be used preferably as desired.

In some embodiment of the present invention, such thermoplastic polymers can be copolymerized if necessary.

A polymer, which can be copolymerized with the thermoplastic polymer described above is for example, urethane acrylate, epoxy acrylate, polyether acrylate, or, polyester acrylate (n=1 .48 to 1 .54) can also be employed. From the viewpoint of adhesiveness of the color conversion sheet, urethane acrylate, epoxy acrylate, and polyether acrylate are preferable.

The matrix materials and the inorganic fluorescent materials mentioned above in - Matrix materials, and in - Inorganic fluorescent materials, can be preferably used for a fabrication of the color conversion sheet (100) and the light emitting diode device (200) of the present invention.

In some embodiments of the present invention, the composition can optionally further comprise one or more of additional inorganic fluorescent materials, which emits blue or red light.

As an additional inorganic fluorescent material which emits blue or red light, any type of publically known materials, for example as described in the second chapter of Phosphor handbook (Yen, Shinoya, Yamamoto), can be used if desired.

Without wishing to be bound by theory, it is believed that the blue light especially around 450 nm wavelength light may lead better plant growth, if it is combined with emission light from the inorganic fluorescent material having the peak wavelength of light emitted from the inorganic fluorescent material in the range from 660 nm to 730 nm, especially the combination of the blue light around 450 nm wavelength and emission light from the inorganic fluorescent material having the peak wavelength of light emitted from the inorganic fluorescent material in the range from 670 nm to 700 nm is preferable for better plant growth. Thus, more preferably, the composition can further comprise at least one blue light emitting inorganic fluorescent material having peak wavelength of light emitted from the inorganic fluorescent material around 450 nm, like described in the second chapter of Phosphor handbook (Yen, Shinoya, Yamamoto).

- Surface treatment method

The surface treatment method for the inorganic materials using the siloxane compound is not particularly limited.

For example, as popular methods, there are two kinds of methods as follows: 1 ) the method of surface treatment of inorganic material using siloxane compound before mixing with resin and 2) the method of surface treatment of inorganic material using siloxane compound to mix inorganic materials, siloxane compounds and resin at the same time. There are two kinds of treatment methods. In the first method mentioned above, there are two kinds of methods: the wet method and the dry method.

In a typical wet method using siloxane, firstly, siloxane compounds are mixed with solution dispersed inorganic materials. After that, the resultant materials in the solution are separated from the solvent, and then the heat treatment at less than 300°C is performed to the resultant materials to acquire the final material. On the other hand, in a typical dry method using siloxane, siloxane compounds and inorganic materials are prepared at least, and the chemicals are mixed by Henschel mixer, which is one of the high-speed mixers and so on. After that, the resultant materials are heated in an oven at a temperature less than 300°C.

In the latter method for preparing the siloxane compound-coated inorganic materials, siloxane compounds and resin at least are prepared, and the surface treatment of the inorganic materials is completed while mixing it with siloxane compounds, inorganic materials and resin by the inflation machine and so on. The first method is more ordinary than the latter one. Preferably, the wet method of the first method is the best way but is not limited.

The siloxane-based compound is not particularly limited, but the silicone oil include, for example, triethoxycaprylylsilane (e.g. AES-3083 of Shin- Etsu Chemical Co., Ltd.), polymethylhydrosiloxane (e.g. KF-99P of Shin- Etsu Chemical Co., and SH1 107 of Dow Corning Toray Co., Ltd.), polydimethylsiloxane-polymethylhydrosiloxane copolymer (e.g. KF-9901 of Shin-Etsu Chemical Co., Ltd.), triethoxysilylethyl polydimethylsiloxyethyl dimethicone (e.g. KF-9908 of Shin-Etsu Chemical Co., Ltd.),

triethoxysilylethyl polydimethylsiloxyethyl hexyl dimethicone (e.g. KF-9909 of Shin-Etsu Chemical Co., Ltd.) and acrylicsilicone resin (e.g. KP-574 of Shin-Etsu Chemical Co., Ltd.).

As the silane coupling agent, for example, silane coupling agent having an amino group, e.g., Y-(2-aminoethyl)aminopropyltrimethoxysilane, v- aminopropyltrimethoxysilane, n- (aminoethyl)Y- aminopropyltrimethoxysilane and n- (aminoethyl)Y- aminopropylmethyledimethoxysilane; silane coupling agent having a glycidyl group, e.g. γ-glycidoxypropyltrimethoxysilane and v- Glycidoxypropyl methyldiethoxysilane; silane coupling agent having a mercapto group, e.g. γ-mercapto-propyltrimethoxysilane; silane coupling agent having a vinyl group, e.g. vinyltriethoxysilane, vinyltrimethoxysilane and vinyl tris(methoxyethoxy)silane; and silane coupling agent having a (meth)acryloyl group, e.g. Y-(meth)acryloyloxypropyltrimethoxysilane ,γ- (meth)acryloyloxypropyltriethoxysilane and γ- (meth)acryloyloxypropyldimethoxymethylsilane are used. The alkoxysilane may be methyltnnnethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n- propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexylt ethoxysilane, decylt methoxisilane and

trifluoropropyltrimethoxysilane.

- The additional volume of the siloxane compound

The weight percentage of siloxane compounds to the volume of inorganic materials is preferably between 0.1 and 20 weight percentage. The siloxane compounds cannot perfectly cover the whole surface of the inorganic materials as they are using less than 0.1 weight percentage and their excessive addition of more than 20 weight percentage cause deterioration or discoloration of the resin. The siloxane compound is preferably treated at 1 % to 5% by weight.

- Another additives

In some embodiments of the present invention, the composition can further comprise at least one additive selected from one or more members of the group consisting of photo initiators, co-polymerizable monomers, cross linkable monomers, bromine-containing monomers, sulfur-containing monomers, adjuvants, dispersants, surfactants, fungicides, antimicrobial agents, and antifungal agents.

In some embodiments of the present invention, the composition can embrace one or more of publically available vinyl monomers that are co- polymerizable. Such as acrylamide, acetonitrile, diacetone-acrylamide, styrene, and vinyl-toluene or a combination of any of these. According to the present invention, the composition can further include one or more of publically available crosslinkable monomers.

For example, cyclopentenyl(meth)acrylates; tetra-hydro furfuryl- (meth)acrylate; benzyl (meth)acrylate; the compounds obtained by reacting a polyhydric alcohol with and α,β-unsaturated carboxylic acid, such as polyethylene-glycol di-(meth)acrylates (ethylene numbers are 2- 14), tri-methylol propane di(meth)acrylate, tri-methylol propane di

(meth)acrylate, tri-methylol propane tri-(meth)acrylate, tri-methylol propane ethoxy tri-(meth) acrylate, tri-methylol propane propoxy tri-(metha) acrylate, tetra-methylol methan tri-(meth) acrylate), tetra-methylol methane

tetra(metha) acrylate, polypropylene glycol di(metha)acrylates (propylene number therein are 2-14), Di-penta-erythritol penta(meth)acrylate, di- penta-erythritol hexa(meth)acrylate, bis-phenol-A Polyoxyethylene di- (meth)acrylate, bis-phenol-A dioxyethylene di-(meth)acrylate, bis-phenol-A trioxyethylene di-(meth)acrylate, bis-phenol-A decaoxyethylene di- (meth)acrylate; the compounds obtained from an addition of an α,β- unsaturated carboxylic acid to a compound having glycidyl, such as tri- methylol propane triglycidylether triacrylate, bis-phenol A diglycidylether diacrylates; chemicals having poly-carboxylic acids, such as a phtalic anhydride; or chemicals having hydroxy and ethylenic unsaturated group, such as the esters with hydroxyethyl (meth)acrylate; alkyl-ester of acrylic acid or methacylic acid, such as methyl (meth)acrylate, ethyl

(meth)acrylate, butyl (meth)acrylate, 2-ethyl hexyl (meth)acrylate; urethane (meth)acrylate, such as the reactants of Tolylene diisocyanate and 2- hydroxyethyl (meth)acrylate, the reactants of tri-methyl hexamethylene diisocyanate and cyclohexane dimethanol, and 2-hydroxyethyl

(meth)acrylate; and a combination of any of these. In a preferred embodiment of the present invention, the crosslinkable monomer is selected from the group consisting of tri-methylol-propane tri (meth)acrylate, di-pentaerythritol tetra-(meth)acrylate, di-pentaerythritol hexa-(meth)acrylate, bisphenol-A polyoxyethylene dimethacrylate and a combination thereof. The vinyl monomers and the crosslinkable monomers described above can be used alone or in combination.

From the viewpoint of controlling the refractive index of the composition and / or the refractive index of the color conversion sheet according to the present invention, the composition can further comprise publically known one or more of bromine-containing monomers, sulfur-containing monomers. The type of bromine and sulfur atom-containing monomers (and polymers containing the same) are not particularly limited and can be used

preferably as desired.

For example, as bromine-containing monomers, new frontier® BR-31 , new Frontier® BR-30, new Frontier® BR-42M (available from DAI-ICHI KOGYO SEIYAKU CO., LTD) or a combination of any of these, as the sulfur- containing monomer composition, IU-L2000, IU-L3000, IU-MS1010

(available from MITSUBISHI GAS CHEMICAL COMPANY, INC.) or a combination of any of these, can be used preferably.

In a preferred embodiment of the present invention, the photo initiator can be a photo initiator that can generates a free radical when it is exposed to an ultraviolet light or a visible light. For example, benzoin-methyl-ether, benzoin-ethyl-ether, benzoin-propyl-ether, benzoin-isobutyl-ether, benzoin-phenyl-ether, benzoin-ethers, benzophenone, N,N'-tetramethyl- 4,4'-diaminobenzophenone (Michler's-ketone), N,N'-tetraethyl- 4,4'diaminobenzophenone, benzophenones, benzil-dimethyl-ketal (Ciba specialty chemicals, IRGACURE® 651 ), benzil-diethyl-ketal, dibenzil ketals, 2,2-dimethoxy-2-phenylacetophenone, p-tert-butyldichloro acetophenone, p-dimethylamino acetophenone, acetophenones, 2,4- dimetyl thioxanthone, 2,4-diisopropyl thioxanthone, thioxanthones, hydroxy cyclohexyl phenyl ketone (Ciba specialty chemicals, IRGACURE® 184), 1 - (4-isopropylphenyl)-2-hydroxy-2-methylpropane-1 -on (Merck, Darocure® 1 1 16), 2-hydroxy-2-methyl-1 -phenylpropane-1 -on (Merck, Darocure® 1 173).

An adjuvant can enhance permeability of effective component (e.g.

insecticide), inhibit precipitation of solute in the composition, or decrease a phytotoxicity. Here, a surfactant means it does not comprise or is not comprised by other additives, for example a spreading agent, a surface treatment and an adjuvant.

Preferably said adjuvant can be selected from the group consisting of a mineral oil, an oil of vegetable or animal origin, alkyl esters of such oils or mixtures of such oils and oil derivatives, and combination thereof.

As one embodiment, the mass ratio of each 1 additive of dispersant, surfactant, fungicide, antimicrobial agent and antifungal agent, to the mass of the invention phosphor in the total amount of the composition is in the range from 50 wt.% to 200 wt.%, more preferably it is from 75 wt.% to 150 wt.%. Exemplified embodiment of an adjuvant is Approach Bl (Trademark,

Kao Corp.).

- Formulation

- Solvent

As a solvent, wide variety of publically known solvents can be used preferably. There are no particular restrictions on the solvent as long as it can dissolve or disperse the matrix material, and the inorganic fluorescent material of the composition.

In a preferred embodiment of the present invention, the solvent can be selected from the group consisting of ethylene glycol monoalkyl ethers, such as, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether; diethylene glycol dialkyl ethers, such as, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; ethylene glycol alkyl ether acetates, such as, methyl cellosolve acetate and ethyl cellosolve acetate; propylene glycol alkyl ether acetates, such as, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate; aromatic hydrocarbons, such as, benzene, toluene and xylene; ketones, such as, methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols, such as, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerin; esters, such as, ethyl 3-ethoxypropionate, methyl 3-methoxypropionate and ethyl lactate; and cyclic asters, such as, γ-butyrolactone. Those solvents are used singly or in combination of two or more, and the amount thereof depends on the coating method and the thickness of the coating.

More preferably, propylene glycol alkyl ether acetates, such as, propylene glycol monomethyl ether acetate (hereafter "PGMEA"), propylene glycol monoethyl ether acetate, or propylene glycol monopropyl ether acetate and / or aromatic hydrocarbons, such as, benzene, toluene and xylene, can be used.

Even more preferably, benzene, toluene, or xylene can be used.

The amount of the solvent in the formulation can be freely controlled. For example, if the formulation is to be spray-coated, it can contain the solvent in an amount of 90 wt.% or more based on total amount of the formulation. Further, if a slit-coating method, which is often adopted in coating a large substrate, is to be carried out, the content of the solvent is normally 60 wt.% or more, preferably in the range from 70 wt.% to 95 wt.% based on the total amount of the formulation.

- Optical medium

In another aspect, the invention relates to an optical medium (100) comprising the composition.

More details of the composition are described in the section of

"Composition". In some embodiments of the present invention, the optical medium is an optical film, for example, a color conversion film, a remote phosphor tape, or another film or a filter for agriculture.

In some embodiments of the present invention, the layer thickness of the optical film is in the range from 5 μιτι to 1 mm, preferably it is in the range from 10 m to 500 μιτι, more preferably it is from 30 μιτι to 200 μιτι, even more preferably from 50 μιτι to 100 μιτι from the view point of better light conversion property and lower production cost. In some embodiments of the present invention, the total amount of the phosphor in the optical film is in the range from 0.01 wt.% to 30wt.% based on the total amount of the matrix material, preferably it is from 0.1 wt.% to 10wt.%, more preferably from 0.5wt.% to 5wt.%, furthermore preferably it is from 1 wt.% to 3wt.%, from the view point of better light conversion property, lower production cost and less production damage of a production machine. - Optical device

In another aspect, the invention relates to an optical device (300) comprising the optical medium (301 ).

Preferably, the optical device (300) further comprises a light source, e.g. a light emitting diode, an organic light emitting diode.

In a preferred embodiment of the present invention, the optical device is a lighting device, a light emitting diode device for agriculture, or building materials of greenhouse.

In another aspect, the invention relates to use of the composition, or formulation in an optical medium fabrication process. In another aspect, the invention relates to use of the optical medium (100) in an optical device or for agriculture.

In another aspect, the invention further relates to use of an inorganic fluorescent material having the peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, and / or at least one inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm, preferably the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, with a matrix material in a light emitting diode device (200).

In another aspect, the present invention furthermore relates to method for preparing the optical medium (100), wherein the method comprises following steps (a) and (b) in this sequence;

(a) providing the composition or the formulation according to claim 8 onto a substrate or into an inflation moulding machine, and (b) fixing the matrix material by evaporating a solvent and / or polymerizing the composition by heat treatment, or exposing the photosensitive composition under ray of light or a combination of any of these.

In some embodiments of the present invention, the composition in step (a) is provided by spincoating, spraycoating, barcoating, or a slit coating method.

In a preferred embodiment of the present invention, the composition or the formulation in step (a) is provided into an inflation-molding machine and the matrix material is fixed by heat treatment of the machine.

(A) providing the optical medium (100) in an optical device. The details of the composition and the formulation are described in the section of "composition" and the section of "formulation". Technical effects

The present invention provides,

quenching of a fluorescent materials,

2. A novel composition suitable for fabricating an optical medium such as a color conversion sheet, and / or an optical device comprising a fluorescent material and matrix material which shows better plant growth ability,

3. A novel composition suitable for fabricating an optical medium such as a color conversion sheet, and / or an optical device comprising a fluorescent material and matrix material, in which can absorb UV and / or purple light (430 nm or shorter wavelength) to keep off harmful insects from plants, and / or

4. A novel composition suitable for fabricating an optical medium such as a color conversion sheet, and / or an optical device comprising a fluorescent material and matrix material, in which can pass through blue light.

The present invention further provides following effects;

controlling of a plant height; controlling of color of fruits; promotion and inhibition of germination; promoting synthesis of chlorophyll and

carotenoids by blue light; plant growth promotion; adjustment and / or acceleration of flowering time of plants; increasing production amount, sugar content, vitamin content of plants such as rice, wheat, fruit trees, vegetables; increase in secondary metabolites (polyphenols,

anthocyanins); increasing a disease resistivity of plants. -Comparative example 1 -

A large plant growth-promoting sheet without phosphor having 50 μιτι layer thickness is made from Petrothene180 (Trademark, Tosoh Corporation) as a polymer with using a Kneading machine and inflation moulding machine. Then all plant seedlings of Boston lettuce are covered by the sheet and it is exposed to light from artificial LED lighting for 16 days. Finally, their fresh weight is measured.

-Comparative example 2- A large plant growth-promoting sheet without phosphor having 50 μιτι layer thickness is made in the same manner as described in comparative examplel .

Then all plant seedlings of Boston lettuce are covered by the sheet and it is exposed to sunlight for 16 days. Finally, their fresh weight is measured.

-Working example 1 -

In a typical synthesis of Mg₂TiO₄:Mn⁴⁺, the phosphor precursors of

Mg₂TiO₄:Mn⁴⁺ are synthesized by a conventional solid-state reaction. The raw materials of magnesium oxide, titanium oxide and manganese oxide are prepared with a stoichiometric molar ratio of 2.000:0.999:0.001 . The chemicals are put in a mixer and mixed by a pestle for 30 minutes. The resultant materials are oxidized by firing at 1000 °C for 3 h in air. To confirm the structure of the resultant materials, XRD measurements are performed using an X-ray diffractometer (RIGAKU RAD-RC).

Photoluminescence (PL) spectra is measured by using a

spectrofluorometer (JASCO FP-6500) at room temperature.

Then, 20 g of Mg₂TiO₄:Mn⁴⁺ phosphor and 0.6 g of siloxane compound (SH 1 107, manufactured by Toray Dow Corning Co., Ltd.) are put in a Waring blender, and mixed at a low speed for 2 minutes. After uniformly surface- treating in this process, the resultant materials are heat-treated in an oven at 140 °C for 90 minutes.

Then, final surface treated Mg₂TiO₄:Mn⁴⁺ phosphors with aligned particle sizes are acquired by shaking with a stainless screen with an opening of 63 pm.

The agricultural material is prepared using Mg₂TiO₄:Mn⁴⁺ as a fluorescent material, and Petrothene180 (Trademark, Tosoh Corporation) as a polymer. 2wt% of Mg₂TiO₄:Mn⁴⁺ phosphors in the polymer is mixed and a large plant growth-promoting sheet having 50 m layer thickness is formed by using a Kneading machine and inflation-moulding machine.

Then all plant seedlings of Boston lettuce are covered by the sheet and it is exposed to light from artificial LED lighting for 16 days. Finally, their fresh weight is measured.

The present invention demonstrated a fresh weight increase from 20.23g to 22.34g in the plants under the growth-promoting sheet compared to the sheet of comparative example 1 . -Working example 2- The phosphor precursors of CaMgSi2O6:Eu²⁺, Mn2⁺ are synthesized by a conventional co-precipitation method.

Then, CaCI₂ · 2H₂O (0.0200 mol, Merck), SiO₂ (0.05 mol, Merck), EuCI₃ · 6H₂O (0.0050 mol, Auer-Remy), MnCI₂ · 4H2O (0.0050 mol, Merck), and MgCI₂ · 4H₂O (0.0200 mol, Merck) are dissolved in deionized water.

NH₄HCO3 (0.5 mol, Merck) is dissolved separately in deionized water.

The two aqueous solutions are simultaneously stirred into deionized water. The combined solution is heated to 90°C and evaporated to dryness.

Then, the residue is annealed at 1000°C for 4 hours under an oxidative atmosphere, and the resulting oxide material is annealed at 1000°C for 4 hours under a reductive atmosphere.

To confirm the structure of the resultant materials, XRD measurements are performed using an X-ray diffractometer (RIGAKU RAD-RC).

Photoluminescence (PL) spectra is measured using a spectrofluorometer (JASCO FP-6500) at room temperature.

Then, 20 g of CaMgSi₂O₆:Eu²⁺, Mn²⁺ phosphor and 0.6 g of siloxane compound (SH 1 107, manufactured by Toray Dow Corning Co., Ltd.) are put in a Waring blender, and mixed at low speed for 2 minutes. After uniformly surface-treating in this process, the resultant materials are heat- treated in an oven at 140°C for 90 minutes. Then, final surface treated CaMgSi₂O6:Eu²⁺, Mn2⁺ phosphors with aligned particle sizes are acquired by shaking with a stainless screen with an opening of 63 μιτι. The agricultural material is prepared using CaMgSi2O6:Eu²⁺, Mn²⁺ as a fluorescent material, and Petrothene180 (Trademark, Tosoh Corporation) as a polymer. 2wt% of CaMgSi2O6:Eu²⁺, Mn2⁺ phosphors in the polymer is mixed and a large plant growth-promoting sheet having 50 μιτι layer thickness is formed by using a Kneading machine and inflation-moulding machine.

The present invention demonstrated a height increase from 21 .45g to 23.81 g in the plants under the growth-promoting sheet compared to the sheet of comparative example 2.

-Working example 3-

20 g of Mg₂TiO₄:Mn⁴⁺ phosphors synthesized in the same manner as described in working example 1 and 0.6 g of siloxane compound (SH 1 107, manufactured by Toray Dow Corning Co., Ltd.) are put in a Waring blender, and mixed at a low speed for 2 minutes. After uniformly surface- treating in this process, the resultant materials are heat-treated in an oven at 140 °C for 90 minutes. Then, final surface treated Mg₂TiO₄:Mn⁴⁺ phosphors with aligned particle sizes are acquired by shaking with a stainless screen with an opening of 63 pm.

The tunnel sheet with Mg₂TiO₄:Mn⁴⁺ is prepared using Mg₂TiO₄:Mn⁴⁺ as a fluorescent material, and Petrothene180 (Trademark, Tosoh Corporation) as a polymer. 2wt% of Mg₂TiO₄:Mn⁴⁺ phosphors in the polymer is mixed and a large plant growth-promoting sheet having 50 μιτι layer thickness is formed by using a Kneading machine and inflation-moulding machine.

Then all plant seedlings of Holly basil are covered by the sheet and it is exposed to the sun light for 28 days. Finally, their fresh weight is measured.

-Working example 4-

The tunnel sheet is prepared in the same manner as described in working example 3 except for 4wt.% of Mg₂TiO₄:Mn⁴⁺ phosphors in the polymer is mixed.

-Working example 5-

The tunnel sheet is prepared in the same manner as described in working example 3 except for 1 wt.% of Mg₂TiO₄:Mn⁴⁺ phosphors in the polymer is mixed.

-Comparative example 3-

All plant seedlings of Holly basil are exposed to the sun light without any tunnel sheet for 28 days. Finally, their fresh weight is measured.

Table 1 shows the results of the measurements. Table 1

Working example 3 146g

Working example 4 146g

Working example 5 146g

Comparative example 3 122g

Claims

Patent Claims

1 . A composition comprising at least one inorganic fluorescent material having a peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, preferably it is from 660 nm to 710 nm, and / or at least one inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm, preferably the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, and a matrix material.

2. The composition according to claim 1 , wherein said inorganic fluorescent material is selected from the group consisting of sulfides, thiogallates, nitrides, oxy-nitrides, silicates, metal oxides, apatites, quantum sized materials, and a combination of any of these, preferably, it is a Mn activated metal oxide phosphor.

3. The composition according to claim 1 or 2, wherein the inorganic fluorescent material is selected from one or more of Mn activated metal oxide phosphors represented by following formulae (I) to (VI) A_xB_yO_z:Mn⁴⁺ - (I) wherein A is a divalent cation and is selected from one or more members ⁵ of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺, B is a tetravalent cation and is Ti³⁺, Zr³⁺ or a

combination of these; x≥1 ; y≥0; (x+2y) = z, preferably A is selected from one or more members of the group consisting of Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Zn²⁺, B is Ti³⁺, Zr³⁺ or a combination of Ti³⁺ and Zr³⁺, x is 2, y is 1 , z is 4, ^ more preferably, formula (I) is Mg₂TiO₄:Mn⁴⁺;

XaZ_bO_c:Mn⁴⁺ - (II) wherein X is a monovalent cation and is selected from one or more

^ members of the group consisting of Li⁺, Na⁺, K⁺, Ag⁺ and Cu⁺; Z is a

tetravalent cation and is selected from the group consisting of Ti³⁺ and Zr³⁺; b≥0; a≥1 ; (0.5a+2b) = c, preferably X is Li⁺, Na⁺ or a combination of these, Z is Ti³⁺, Zr³⁺ or a combination of these a is 2, b is 1 , c is 3, more preferably formula (II) is Li₂TiO3:Mn⁴⁺;

20

D_dEeO_f:Mn⁴⁺ - (III) wherein D is a divalent cation and is selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, ^ Mn²⁺, Ce²⁺ and Sn²⁺; E is a trivalent cation and is selected from the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; e≥10; d≥0; (d+1 .5e) = f, preferably D is Ca²⁺, Sr²⁺, Ba²⁺ or a combination of any of these, E is Al³⁺, Gd³⁺ or a combination of these, d is 1 , e is 12, f is 19, more preferably formula (III) is CaAli₂Oi₉:Mn⁴⁺;

30 DgE_hOi:Mn⁴⁺ - (IV) wherein D is a trivalent cation and is selected from one or more members of the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; E is a trivalent cation and is selected from the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; h≥0; a≥g; (1 .5g+1 .5h) = I, preferably D is La³⁺, E is Al³⁺, Gd³⁺ or a combination of these, g is 1 , h is 12, i is 19, more preferably formula (IV) is LaAIO₃:Mn⁴⁺; GjJ_kLiO_m:Mn⁴⁺ - (V) wherein G is a divalent cation and is selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺; J is a trivalent cation and is selected from the group consisting of Y³⁺, Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; L is a trivalent cation and is selected from the group consisting of Al³⁺, Ga³⁺, Lu³⁺, Sc³⁺, La³⁺ and ln³⁺; l≥0; k≥0; j≥0; (j+1 .5k+1 .51) = m, preferably G is selected from Ca²⁺, Sr²⁺, Ba²⁺ or a combination of any of these, J is Y³⁺, Lu³⁺ or a combination of these, L is Al³⁺, Gd³⁺ or a combination of these, j is 1 , k is 1 , I is 1 , m is 4, more preferably it is CaYAIO₄:Mn⁴⁺; and

dependently of each other, selected from one or more members of the group consisting of Mg²⁺, Zn²⁺, Cu²⁺, Co²⁺, Ni²⁺, Fe²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Mn²⁺, Ce²⁺ and Sn²⁺; R is Ge³⁺, Si³⁺, or a combination of these; n≥2; o≥0; p≥1 ; (n+o+2.0p) = q, preferably M is Ca²⁺, Sr²⁺, Ba²⁺ or a combination of any of these, Q is Mg²⁺, Ca²⁺, Sr²⁺, Ba²⁺, Zn²⁺ or a combination of any of these, R is Ge³⁺, Si³⁺, or a combination of these, n is 3, o is 1 , p is 2, q is 8, more preferably it is (Ca, Ba, Sr)₃MgSi2O₈:Eu, Mn.

4. The composition according to any one of claims 1 to 3,

wherein the inorganic fluorescent material is a Mn activated metal oxide phosphor represented by chemical formula (VI).

5. The composition according to any one of claims 1 to 4, wherein the matrix material wherein the matrix material comprises a polymer selected from the group consisting of photosetting polymer, a thermosetting polymer, a thermoplastic polymer, and a combination of any of these.

6. The composition according to any one of claims 1 to 5, the total amount of the phosphor of the composition is in the range from 0.01 wt.% to 30wt.% based on the total amount of the matrix material, preferably it is from 0.1 wt.% to 10wt.%, more preferably from 0.5wt.% to 5wt.%, furthermore preferably it is from 1wt.% to 3wt.%.

7. The composition according to any one of claims 1 to 6, further comprises at least one additive selected from one or more members of the group consisting of photo initiators, co-polymarizable monomers, cross linkable monomers, bromine-containing monomers, sulfur-containing monomers, adjuvants, dispersants, surfactants, fungicides, antimicrobial agents, and antifungal agents.

8. A formulation comprising the composition according to any one of claims 1 to 7, and a solvent.

9. An optical medium (100) comprising the composition according to any one of claims 1 to 7.

10. An optical device (300) comprising the optical medium (100) according to claim 8.

1 1 . Use of the composition according to any one of claims 1 to 7, or the formulation according to claim 8 in an optical medium fabrication process.

12. Use of the optical medium (100) according to claim 9, in an optical device or for agriculture.

13. Use of the inorganic fluorescent material having the peak wavelength of light emitted from the inorganic fluorescent material in the range from 650 nm to 730 nm, and / or at least one inorganic fluorescent material having a first peak wavelength of light emitted from the inorganic fluorescent material in the range from 400nm to 500nm and a second peak wavelength of light emitted from the inorganic fluorescent material from 600 nm to 750 nm, preferably the first peak wavelength of light emitted from the inorganic fluorescent material is in the range from 430 nm to 490 nm, and the second peak light emission wavelength is in the range from 650 nm to 720 nm, more preferably the first peak wavelength of light emitted from the inorganic fluorescent material is 450 nm and the second peak wavelength of light emitted from the inorganic fluorescent material is in the range from 660 nm to 710 nm, with a matrix material in an optical medium (200).

14. Method for preparing the optical medium (100), wherein the method comprises following steps (a) and (b) in this sequence; (a) providing the composition according to any one of claims 1 to 7, or the formulation according to claim 8 onto a substrate or into an inflation moulding machine, and

(b) fixing the matrix material by evaporating a solvent and / or polymerizing the composition by heat treatment, or exposing the photosensitive composition under ray of light or a combination of any of these.

15. Method for preparing the optical device (200) according to claim 10, wherein the method comprises following step (A);

(A) providing the optical medium (100) according to claim 9, in an optical device (200).