JP2006208985A - Light diffusing member and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light diffusing member capable of adjusting an average coefficient of linear expansion in a wide range and having excellent heat resistance, high rigidity and excellent dimensional stability with respect to the the light diffusing member using crystallized glass and having preferable light diffusing property, and to provide a method for manufacturing the light diffusing member. <P>SOLUTION: The light diffusing member contains a crystal in a glass phase and shows ≥0.1% haze to C-light when the member has 0.1 mm thickness. The method for manufacturing the light diffusing member comprises the steps of: melting a glass source material; molding the melted glass; gradually cooling the molded glass; and performing a heat treatment after gradual cooling. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light diffusing member using crystallized glass and having good light diffusibility, and can adjust an average linear expansion coefficient in a wide range, has excellent heat resistance, has high rigidity, and has excellent dimensional stability. The present invention relates to a light diffusing member and a manufacturing method thereof.

  Resins and glass are known as materials used as the light diffusion plate. The light diffusing plate made of these materials is, for example, using a milky white polycarbonate resin having light diffusibility in the material itself, or imparting light diffusibility by subjecting the surface of the material to processing such as acid treatment or sand scouring, A method of applying a light diffusive film or a milky white film using the material itself as a substrate is used.

  Many of these conventional light diffusing plates have a high expansion coefficient and low rigidity, which causes a problem in dimensional stability. In addition, since the heat resistance is low, there is a problem that softening occurs in a high temperature environment. In the case of a light diffusing member made of a resin, the anisotropy of the linear expansion coefficient caused by the direction of injection molding also causes a problem in dimensional stability.

On the other hand, in recent years, in light diffusing members used in various fields, demands for various physical properties such as dimensional stability are severe.
For example, with an increase in the size of display devices such as liquid crystal displays and projector televisions, high dimensional stability is required for diffusion plates used for these devices.
In addition, when measuring diffused light precisely in an environment with temperature change, the light diffusing member of the measuring device is supported so that the light diffusing property does not change due to temperature change and the light diffusibility does not change. It is required to match the expansion characteristics with the member. Even in an environment where the temperature change is small, if the diffused light source has a large energy such as laser light, the temperature of the light diffusing member becomes high, causing deformation or breakage, and the light diffusibility becomes unstable. End up. In such a case, the light diffusing member may be required to have extremely low expansion.

  In order to solve the above-mentioned problems and satisfy these strict requirements, there is no anisotropy in the expansion characteristic, and from the negative linear expansion characteristic to the extremely low expansion, which is almost zero expansion, and eventually high expansion. The average linear expansion coefficient can be adjusted over a wide range according to the intended use and usage environment, it must have excellent heat resistance, and must have high rigidity and dimensional stability. However, there has been no light diffusing member having such good characteristics.

  Patent Document 1 proposes a light diffusing plate made of a resin composition for the purpose of good rigidity and dimensional stability. However, Tg is low at 80 ° C. to 250 ° C. and has a low coefficient of linear expansion. There is a directionality, and neither rigidity nor dimensional stability is satisfactory.

JP 2004-175963 A

  The problem of the present invention is to solve the above-mentioned problems in the prior art, have good light diffusibility, have no anisotropy in expansion characteristics, can adjust the average linear expansion coefficient over a wide range, and is heat resistant. It is an object to provide a light diffusing member that is excellent and has high rigidity and excellent dimensional accuracy, and a method for manufacturing the same.

  The inventor of the present invention, as a result of diligent test research to solve the above-mentioned problems, results in a light diffusing member using crystallized glass having crystals precipitated in the glass phase, while having good light diffusibility, The average linear expansion coefficient can be adjusted over a wide range according to the environment and purpose of use, the expansion characteristics are isotropic, it has excellent heat resistance, high rigidity, and good dimensional stability. The invention has been completed.

Preferred embodiments of the present invention are represented by any of the configurations listed below.
(Structure 1) A light diffusing member, wherein the glass phase contains crystals and has a haze value of 0.1% or more for C light when the thickness is 0.1 mm.
(Configuration 2) Crystals contained in the glass phase are selected from Si, Al, P, B, Li, Na, K, Cs, Mg, Ca, Sr, Ba, Zn, Cu, Ni, Co, and Mo. 2. The light diffusing member according to Configuration 1, comprising at least two components.
(Configuration 3) The light diffusing member according to Configuration 1 or 2, wherein the total light transmittance with respect to the C light when the thickness is 0.1 mm is 5% or more.
(Structure 4) The light diffusing member according to Structures 1 to 3, wherein the light reflectance at a wavelength of 200 to 2500 nm is 1% or more.
(Constitution 5) The light diffusing member according to any one of Constitutions 1 to 4, wherein the average linear expansion coefficient is + 200 × 10 ⁻⁷ / ° C. or less in a temperature range of 0 to 50 ° C.
(Structure 6) The light according to any one of Structures 1 to 5, wherein the average linear expansion coefficient is in the range of −100 × 10 ⁻⁷ / ° C. to + 200 × 10 ⁻⁷ / ° C. in the temperature range of 0 to 50 ° C. Diffusion member.
(Arrangement 7) The light diffusing member according to Arrangements 1 to 6, wherein the average crystal particle diameter is 5 nm or more.
(Structure 8) The light diffusing member according to Structures 1 to 7, wherein the average crystal particle diameter is in the range of 5 nm to 2000 nm.
(Configuration 9) The crystals contained in the glass phase are in mass%,
SiO2 5% to 90%,
Li2O3 0% -50%,
Al2O3 0% -50%,
The light-diffusion member of the structure 1-8 characterized by including each component of these.
(Configuration 10) The crystals contained in the glass phase are mol%,
SiO2 3% to 95%,
Li2O3 0% -90%,
Al2O3 0% -50%,
The light-diffusion member of the structure 1-8 characterized by including each component of these.
(Structure 11) A light diffusing member comprising a step of melting a glass raw material, a step of forming molten glass, a step of gradually cooling the formed glass, and a step of performing heat treatment after slow cooling Manufacturing method.

  In one embodiment of the light diffusing member of the present invention, it is important that the glass is reheated to precipitate crystals in the glass phase. The present invention achieves high rigidity and heat resistance by precipitating fine crystals in the glass phase. Further, the present invention realizes light diffusibility by the precipitated crystal becoming a main light diffusion factor. Crystal precipitation due to reheating of the glass is uniformly distributed on the member, so that it is possible to achieve good light diffusion performance and good uniformity of diffused light. Furthermore, since the light diffusing member of the present invention is obtained by precipitating crystals in the glass phase, there is no anisotropy of the linear expansion coefficient like the light diffusing member made of the resin composition, or it can be ignored. It is minute.

  In order for the light diffusing member of the present invention to have good light diffusibility, the average crystal particle diameter of the crystals contained in the glass phase is preferably 5 nm or more, and light diffusion is wide in the range of 5 nm to 2000 nm. Since performance can be adjusted, it is more preferable. Most preferably, it is the range of 100 nm-1000 nm.

  Furthermore, by appropriately selecting the crystals to be precipitated and adjusting the ratio of the crystals to be precipitated with respect to the mass of the entire member, the average linear expansion coefficient and haze value of the light diffusing member, the total light transmittance, the light reflectance, etc. can be broadly selected. It becomes possible to adjust to.

  In order to obtain good diffusibility, the haze value of the light diffusing member of the present invention is preferably 0.1% or more with respect to C light when the thickness is 0.1 mm, and is preferably 1% or more. More preferably, it is most preferably 5% or more.

Here, the haze value is obtained by quantifying the light diffusibility of the material, and it can be said that the higher (larger) the value, the better the light diffusibility.
The haze value represented by the present invention refers to that measured by the following method.
Specifically, a 20 × 20 × 0.1 mm plate-like sample is prepared, and both surfaces thereof are optically polished. Whether optical polishing is satisfactorily confirmed can be easily confirmed by the fact that no grain is observed on the polished surface. After the polished sample is washed, it is measured using a haze meter (“HGM-2DP” manufactured by Suga Test Instruments Co., Ltd.).

  The C light is standard light C defined by the International Commission on Illumination (CIE). This is obtained by applying a specified filter to a gas-filled tungsten light bulb having a color temperature of 6740 ° K., which is lit with a specified rule. The nature of this light corresponds to daylight including blue sky light.

When using for the purpose of diffusing the light which permeate | transmits a light-diffusion member, it is preferable that the transmittance | permeability of light is high since the loss of light quantity decreases. Therefore, in one aspect of the light diffusing member of the present invention, the total light transmittance for C light when the thickness is 0.1 mm is preferably 5% or more, more preferably 7% or more. Preferably, it is most preferably 10% or more.
The total light transmittance represented by the present invention is evaluated by the method shown in JIS K 7361-1, and specifically shows the average transmittance at a wavelength of 380 to 770 nm.

The light diffusing member of the present invention can also be used for the purpose of diffusing reflected light. In this case, it is preferable that the reflectance is high because the loss of light amount is reduced. Accordingly, in one aspect of the light diffusing member of the present invention, the light reflectance at a wavelength of 200 to 2500 nm is preferably 1% or more, more preferably 2% or more, and 3% or more. Is most preferred.
The light reflectance represented by the present invention means an average value of the reflectance of each wavelength measured in the wavelength range of 200 to 2500 nm.

It is preferable that the average linear expansion coefficient of the light diffusing member of the present invention can be adjusted in a wide range according to the use environment and the purpose of use. Therefore, the average linear expansion coefficient is preferably + 200 × 10 ⁻⁷ / ° C. or less in the temperature range of 0 to 50 ° C., and is in the range of −100 × 10 ⁻⁷ / ° C. to + 200 × 10 ⁻⁷ / ° C. It is more preferable. Within this range, it is possible to match the average linear expansion coefficient with materials such as metal, ceramic, crystallized glass, glass and resin.
In addition, the light diffusing member itself has high dimensional stability when it has an extremely low expansion range of −5 × 10 ⁻⁷ / ° C. to + 5 × 10 ⁻⁷ / ° C. in the temperature range of 0 to 50 ° C. Therefore, it is most preferable.

In one aspect of the light diffusing member of the present invention, the crystals contained in the glass phase are Si, Al, P, B, Li, Na, K, Cs, Mg, Ca, Sr, Ba, Zn, Cu. It is preferable to contain at least two components selected from Ni, Co, and Mo.
A crystal for adjusting the average linear expansion coefficient, haze value, total light transmittance, light reflectance, etc. over a wide range by containing at least two or more components selected from these components. It is possible to cover almost all kinds of the crystal and to change the kind and ratio of the desired crystal in various ways.

In one of the embodiments of the light diffusing member of the present invention, the crystals contained in the glass phase are in mass%,
_{SiO 2 5~90%, Al 2 O} 3 0~50%, Li 2 O 0~50%, preferably includes the components of.
Within this range, it is possible to cover the main crystal types for adjusting the average linear expansion coefficient over a wide range.

In one embodiment of the light diffusing member of the present invention, the crystal contained in the glass phase is mol%,
_{SiO 2 3~95%, Al 2 O} 3 0~90%, Li 2 O 0~50%, preferably includes the components of.
As described above, within this range, it is possible to cover the main crystal types for adjusting the average linear expansion coefficient over a wide range.

  In order to contain each of the above components in the crystal, these components may be included in the glass material to be melted, and the heating conditions (crystallization conditions) for reheating the glass may be adjusted as appropriate. .

When β-eucryptite and / or β-eucryptite solid solution and / or β-quartz and / or β-quartz solid solution are included in the glass phase, the average temperature range of 0 to 50 ° C. The linear expansion coefficient can be adjusted in the range of −100 × 10 ⁻⁷ / ° C. to + 50 × 10 ⁻⁷ / ° C.

β-quartz and / or β-quartz solid solution, and / or β-spodumene (β-Li ₂ O.Al ₂ O ₃ .SiO ₂ ) and / or β-spodumene solid solution (β-Li ₂ O.Al ₂ O ₃₎ · a SiO ₂ solid solution) when included in the glass phase, adjusts the average linear expansion coefficient of the temperature range of 0 to 50 ° C. in the range of ^{-10 × 10 -7 / ℃ ~ +} 10 × 10 -7 / ℃ be able to.

In particular, in order to realize an extremely low expansion characteristic in which the average linear expansion coefficient of the light diffusing member is −5 × 10 ⁻⁷ / ° C. to + 5 × 10 ⁻⁷ / ° C. in the temperature range of 0 to 50 ° C., Contains β-quartz and / or β-quartz solid solution, and the crystals in the glass phase are in mass%, SiO ₂ 50 to 62%, P ₂ O _{5 5 to} 10%, Al ₂ O ₃ 22 to 26%, Li _{2 O3~5%, TiO 2 1~4%} , preferably contains the respective components of the ZrO 2 1 to 4%.

α-quartz (α-SiO ₂ ), and / or α-quartz solid solution (α-SiO ₂ solid solution), and / or α-cristobalite (α-SiO ₂ ), and / or α-cristobalite solid solution (α-SiO ₂₎ When the solid solution is included in the glass phase, the average linear expansion coefficient in the temperature range of 0 to 50 ° C. can be adjusted in the range of + 50 × 10 ⁻⁷ / ° C. to + 200 × 10 ⁻⁷ / ° C.

  In addition, the average linear expansion coefficient of the light diffusing member and the average crystal particle diameter of the crystal can be variously adjusted by selecting the type of crystal included in the glass phase.

Lithium disilicate (Li ₂ O.2SiO ₂ ) and / or α-quartz (α-SiO ₂ ) and / or α-quartz solid solution (α-SiO ₂ solid solution) and / or α-cristobalite (α-SiO ₂ ), and / or α-cristobalite solid solution (α-SiO ₂ solid solution)
Is included in the glass phase, the average linear expansion coefficient at −50 to + 70 ° C. is in the range of + 65 × 10 ⁻⁷ / ° C. to + 130 × 10 ⁻⁷ / ° C., and the average crystal grain size is 0.01 to 1. It can be in the range of 00 μm.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 70 ~79%,
Li ₂ O 5 ~12%,
K ₂ O 0-4%,
MgO 0 to less than 2%,
ZnO 0 to less than 2%,
P ₂ O ₅ 1.5~ 3%,
ZrO ₂ 1.5-7%,
Al ₂ O ₃ 3-9%,
Sb2O3 + As2O3 0-2%,
It is preferable to contain each component of the range.

α-quartz (α-SiO ₂ ) and / or α-quartz solid solution (α-SiO ₂ solid solution),
Is included in the glass phase, the average linear expansion coefficient at −50 to + 70 ° C. is in the range of + 60 × 10 ⁻⁷ / ° C. to + 130 × 10 ⁻⁷ / ° C., and the average crystal particle size is 1.00 μm or less. be able to.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 70 ~77%,
Li ₂ O 5 to less than 9%,
K ₂ O ₂ ~ 5%,
MgO + ZnO + SrO + BaO 1-2%,
_{Y 2 O 3 + WO 3 +} La 2 O 3 + Bi 2 O 3 1 ~ 3%,
P ₂ O ₅ 1.0-2.5%,
ZrO ₂ 2.0-7%,
Al ₂ O ₃ 5-10%,
Na ₂ O 0 to 1%,
_{Sb 2 O 3 + As 2 O} 3 0 ~ 2%,
It is preferable to contain each component of the range.

Cordierite _{(Mg 2 Al 4 Si 5 O} 18 ), and / or cordierite solid solution _{(Mg 2 Al 4 Si 5 O} 18 solid solution), and / or spinel, and / or spinel solid solution, and / or enstatite (MgSiO ₃ ), And / or enstatite solid solution (MgSiO ₃ solid solution), and / or β-quartz (β-SiO ₂ ), and / or β-quartz solid solution (β-SiO ₂ solid solution), and / or magnesium titanate (MgTi) ₂ O ₅ ) and / or magnesium titanate solid solution (MgTi ₂ O ₅ solid solution)
Is included in the glass phase, the average linear expansion coefficient at −50 to + 70 ° C. can be in the range of + 30 × 10 ⁻⁷ / ° C. to + 65 × 10 ⁻⁷ / ° C.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 40 ~60%,
MgO 10-18%,
Al ₂ O ₃ 10 to less than 20%,
_{P 2 O 5 0 ~ 4%} ,
B ₂ O ₃ 0-4%,
CaO 0.5-4%,
SrO 0-2%,
BaO 0-5%,
ZrO ₂ 0-5%,
TiO ₂ 2.5-12%,
Bi ₂ O ₃ 0-6%,
Sb ₂ O ₃ 0 to 1%,
As ₂ O ₃ 0 to 1%,
Fe ₂ O ₃ 0-2%,
It is preferable to contain each component of the range.

Enstatite (MgSiO ₃ ), and / or enstatite solid solution (MgSiO ₃ solid solution), and / or magnesium titanate (MgTi ₂ O ₅ ), and / or magnesium titanate solid solution (MgTi ₂ O ₅ solid solution), and / or Spinel and / or spinel solid solution,
In the glass phase, the average linear expansion coefficient at −50 to + 70 ° C. is in the range of + 40 × 10 ⁻⁷ / ° C. to + 60 × 10 ⁻⁷ / ° C., and the average crystal particle size is 0.05 μm to 0.00. It can be in the range of 30 μm.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 40~60%,
MgO 10-20%,
Al ₂ O ₃ less than 10-20%,
CaO 0.5-4%,
SrO 0.5-4%,
BaO 0-5%,
ZrO ₂ 0-5%,
Over TiO ₂ 8% to 12%,
Bi ₂ O ₃ 0-6%,
Sb ₂ O ₃ 0 to 1%,
As ₂ O ₃ 0-1%,
It is preferable to contain each component of the range.

β-quartz (β-SiO ₂ ) and / or β-quartz solid solution (β-SiO ₂ solid solution) and / or enstatite (MgSiO ₃ ) and / or enstatite solid solution (MgSiO ₃ solid solution) and / or When stellite and / or forsterite solid solution is contained in the glass phase, the average crystal particle diameter can be in the range of 0.05 μm to 0.30 μm.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 40 ~60%,
MgO 10-20%,
Al ₂ O ₃ 10 to less than 20%,
P ₂ O ₅ 0.5~ 2.5%,
_{B 2 O 3 1 ~ 4%} ,
Li ₂ O 0.5-4%,
CaO 0.5-4%,
ZrO ₂ 0.5-5%,
TiO ₂ 2.5-8%,
Sb ₂ O ₃ 0.01~0.5%,
As ₂ O ₃ 0-0.5%,
SnO ₂ 0-5%,
MoO ₃ 0 ~ _3%,
CeO 0-5%,
Fe ₂ O ₃ 0-5%,
It is preferable to contain each component of the range.

β-quartz (β-SiO ₂ ), and / or β-quartz solid solution (β-SiO ₂ solid solution), and / or β-spodumene (β-Li ₂ O.Al ₂ O ₃ .SiO ₂ ), and / or β- spodumene solid solution _{(β-Li 2 O · Al} 2 O 3 · SiO 2 solid solution), and / or β- eucryptite _{(β-Li 2 O · Al} 2 O 3 · 2SiO 2, provided that a part of Li2O is substitutable), and / or β- eucryptite solid solution _{(β-Li 2 O · Al} 2 O 3 · 2SiO 2 solid solution, although some of Li2O substitution of MgO and / or ZnO with MgO and / or ZnO Possible) and / or the glass phase contains an average coefficient of linear expansion at −50 to + 600 ° C. within the range of −10 × 10 ⁻⁷ / ° C. to + 35 × 10 ⁻⁷ / ° C. The crystal particle diameter can be in the range of 5 nm to 0.10 μm.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 50~65%,
P ₂ O ₅ 0-10%,
Al ₂ O ₃ 22-30%,
Li ₂ O 1.5-5%,
MgO 0.5-2%,
ZnO 0.2-15%,
CaO 0.3-4%,
BaO 0.5-5%,
TiO ₂ 1-4%,
ZrO ₂ 1-5%,
Nb ₂ O ₅ 0-5%,
La ₂ O ₃ 0-5%,
Y ₂ O ₃ 0-5%,
As ₂ O ₃ + Sb ₂ O ₃ 0-4%,
It is preferable that PbO, Na ₂ O, and K ₂ O are substantially not included while containing each component in the range.

Spinel crystals (preferably garnite (ZnAl ₂ O ₄ )) and / or solid solutions of spinel crystals (preferably garnite solid solution (ZnAl ₂ O ₄ solid solution))
Is included in the glass phase, the average linear expansion coefficient at −50 to + 600 ° C. can be in the range of + 35 × 10 ⁻⁷ / ° C. to + 65 × 10 ⁻⁷ / ° C.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 30~65%,
Al ₂ O ₃ 5~35%,
ZnO 5-35%,
MgO 1-20%,
TiO ₂ 1-15%,
CaO + SrO + BaO + B ₂ O ₃ + La ₂ O ₃ + Y ₂ O ₃ + Gd ₂ O ₃ + Ta ₂ O ₅ + Nb ₂ O ₅ + WO ₃ + Bi ₂ O ₃ 0.5-20%,
However, B ₂ O ₃ 0-10%,
Ta ₂ O ₅ + Nb ₂ O ₅ + WO ₃ + Bi ₂ O ₃ 0-10%,
ZrO ₂ 0 to less than 2%,
P ₂ O ₅ 0-5%,
SnO ₂ 0-2%,
However, ZrO ₂ + P ₂ O ₅ + SnO ₂ 0-7%,
As ₂ O ₃ + Sb ₂ O ₃ 0-4%,
It is preferable to contain each component of the range.

β-eucryptite, and / or
β-eucryptite solid solution, and / or
β-quartz (β-SiO ₂ ) and / or
β-quartz solid solution (β-SiO ₂ solid solution) and / or
The the inclusion in the glass phase, in the range of average linear expansion coefficient of ^{-25 × 10 -7 / ℃ ~-} 15 × 10 -7 / ℃ at -40 ℃ ~ + 80 ℃, Young's modulus be at least 60GPa Can do.

In order to include the above crystals, the glass raw material is a mass percentage based on oxide,
SiO ₂ 40~59%,
Al ₂ O ₃ 10-30%,
Li ₂ O 1-5.4%,
And SiO ₂ / (Al ₂ O ₃ + Li ₂ O) ≧ 1.5,
ZnO 3-10%,
BaO + SrO 0.5-6%,
TiO ₂ + ZrO ₂ 1.0-5.0%,
B ₂ O ₃ 0-5%,
BaO 0-4%,
SrO 0-4%,
CaO 0-2%,
ZrO ₂ 0.5-3%,
TiO ₂ 0.5-3%,
HfO ₂ 0-3%,
As ₂ O ₃ + Sb ₂ O ₃ 0-2%,
It is preferable that the P ₂ O ₅ content is less than 4% by mass and MgO, PbO, Na ₂ O and K ₂ O are not substantially contained, while containing each component in the range.

When a crystal represented by Li _{1 + x + y} Al _x Ti _2-x Si _y P _3-y (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) is included in the glass phase, the average coefficient of linear expansion at 100 ° C. to 300 ° C. is The average crystal particle diameter in the range of + 60 × 10 ⁻⁷ / ° C. to + 300 × 10 ⁻⁷ / ° C. can be in the range of 0.1 μm to 2 μm.

In order to include the above crystals, the glass raw material is mol% based on oxides and Li ₂ O 12-18%,
_{Al 2 O 3 + Ga 2 O} 3 5~10%,
TiO ₂ + _{GeO 2} 35~45%,
SiO ₂ 1~10%,
P ₂ O ₅ 30~40%,
It is preferable to contain each component of the range.

Other crystals that can be included in the glass phase are α-tridymite, petalite, Al ₂ TiO ₅ , cordierite spinel crystals, forsterite, wollastonite, diopsite, nepheline, nephrin, clinoenstatite, ano Sites, celsian, gelenite, felsper, willemite, mullite, corundum, lanquinite, larnite, and solid solutions thereof.

The light diffusing member of the present invention can achieve high rigidity due to the crystals contained in the glass phase, and the Young's modulus can be in the range of 70 GPa to 160 GPa.
For high dimensional stability, it is preferably 60 GPa or more, more preferably 70 GPa or more, and most preferably 80 GPa or more.

  The light diffusing member of the present invention has high heat resistance. The upper limit of the temperature at which the light diffusing member of the present invention is not softened and maintains a shape, strength, and the like substantially equal to those at room temperature is approximately between 400 ° C and 1000 ° C.

The light diffusing member of the present invention dissolves a glass raw material, performs hot forming or cold working and then slowly cools, and then performs a first heat treatment to form crystal nuclei in the glass phase, followed by second It is manufactured by crystallization by heat treatment. Further, after cooling to room temperature after the second heat treatment, a third heat treatment may be performed again to recrystallize.
At this time, the melting temperature of the glass raw material is preferably in the range of 1000 ° C to 1800 ° C, more preferably in the range of 1100 ° C to 1700 ° C, and most preferably in the range of 1200 ° C to 1600 ° C.
The temperature of the first heat treatment is preferably in the range of 400 ° C to 900 ° C, more preferably in the range of 450 ° C to 850 ° C, and most preferably in the range of 500 ° C to 800 ° C. The heating time at this time is preferably 0.1 to 100 hours, and more preferably 1 to 100 hours.
The temperature of the second heat treatment is preferably in the range of 550 ° C to 1200 ° C, more preferably in the range of 600 ° C to 1150 ° C, and most preferably in the range of 650 ° C to 1100 ° C. The heating time at this time is preferably 0.1 to 100 hours, and more preferably 1 to 100 hours.
The temperature of the third heat treatment is preferably in the range of 550 ° C to 1250 ° C, more preferably in the range of 600 ° C to 1200 ° C, and most preferably in the range of 650 ° C to 1150 ° C. The heating time at this time is preferably 0.1 to 100 hours, and more preferably 0.5 to 100 hours.

  The light diffusing member of the present invention may have a surface having a surface shape such as a Fresnel lens shape or a cylindrical lens shape, or may be a laminated plate in which such a shape is separately laminated with another material. is there. When the light diffusing member of the present invention directly imparts a Fresnel lens shape or a cylindrical lens shape, the molten glass can be cast and molded into a mold having these shapes.

The light diffusing member according to the present invention can be formed into various films such as various antireflection films in order to prevent reflection of light from the light source.
The film formation means that a new layer is formed on the surface layer by means of vapor deposition (physical vapor deposition, chemical vapor deposition, etc.), plating (electroplating, electroless plating, hot dipping, etc.), painting, coating, printing, and the like. Examples of the method for laminating a metal layer or metal oxide layer on the surface include physical vapor deposition, chemical vapor deposition, thermal spraying, and plating. As the physical vapor deposition method, a vacuum vapor deposition method, sputtering, ion plating, or the like can be applied. As the chemical vapor deposition (CVD) method, a thermal CVD method, a plasma CVD method, a photo CVD method, or the like can be applied. As the thermal spraying method, an atmospheric pressure plasma spraying method, a low pressure plasma spraying method, or the like can be applied. Examples of the plating method include an electroless plating (chemical plating) method, a hot dipping method, and an electroplating method. In the electroplating method, a laser plating method can be used.

The light diffusing member of the present invention has high uniformity of diffused light and excellent light diffusibility due to crystals uniformly dispersed in the glass phase.
According to the present invention, a light diffusing member having good light diffusibility, capable of adjusting an average linear expansion coefficient in a wide range, excellent in heat resistance, high rigidity and excellent in dimensional stability, and their A manufacturing method can be provided.

A preferred embodiment of the present invention will be described. Note that the present invention is not limited to these embodiments.

Examples of the present invention are shown in Table 1.
Glass raw materials having the composition shown in Table 1 were melted at 1300 to 1600 ° C., formed into a 100 mm square, annealed, and then nucleated at 600 to 800 ° C. for 5 to 100 hours, and crystallized at 650 to 900 ° C. for 1 to 100 hours Then, grinding and polishing were performed to obtain a plate-shaped light diffusion member. The details of the crystallization conditions for each example are shown in Table 1.
The main crystal phase of the obtained light diffusing member, the average linear expansion coefficient at 0 ° C. to 50 ° C., the average crystal particle diameter of the main crystal phase, the total light transmittance for C light when the thickness is 0.1 mm, wavelength 200 Table 1 shows the haze value with respect to C light when the light reflectivity, the Young's modulus, and the thickness are ˜2500 nm.

The light diffusing member of the present invention includes a light diffusing plate of a display device, a light diffusing plate of various measuring devices, a light cover, a meter, a signboard, an image reading device, a roof material for a vehicle, a roof material for a ship, a roof material for a house, and a solar cell. Suitable for covers and the like.

Claims (11)

A light diffusing member comprising a crystal in a glass phase and having a haze value of 0.1% or more for C light when the thickness is 0.1 mm. Crystals contained in the glass phase include at least two components selected from Si, Al, P, B, Li, Na, K, Cs, Mg, Ca, Sr, Ba, Zn, Cu, Ni, Co, and Mo. The light diffusing member according to claim 1, comprising: 3. The light diffusing member according to claim 1, wherein the total light transmittance for C light when the thickness is 0.1 mm is 5% or more. 4. 4. The light diffusing member according to claim 1, wherein the light reflectance at a wavelength of 200 to 2500 nm is 1% or more. 5. The light diffusing member according to claim 1, wherein an average linear expansion coefficient is + 200 × 10 ⁻⁷ / ° C. or less in a temperature range of 0 to 50 ° C. 5. 6. The light diffusing member according to claim 1, wherein an average linear expansion coefficient is in a range of −100 × 10 ⁻⁷ / ° C. to + 200 × 10 ⁻⁷ / ° C. in a temperature range of 0 to 50 ° C. 6. 7. The light diffusing member according to claim 1, wherein an average crystal particle diameter is 5 nm or more. 8. The light diffusing member according to 1 to 7, wherein the average crystal particle diameter is in the range of 5 nm to 2000 nm. The crystals contained in the glass phase are mass%,
SiO2 5% to 90%,
Li2O3 0% -50%,
Al2O3 0% -50%,
The light diffusing member according to claim 1, comprising the following components. The crystals contained in the glass phase are mol%,
SiO2 3% to 95%,
Li2O3 0% -90%,
Al2O3 0% -50%,
The light diffusing member according to claim 1, comprising the following components. A method for producing a light diffusing member, comprising: a step of melting a glass raw material; a step of forming molten glass; a step of gradually cooling the formed glass; and a step of performing heat treatment after slow cooling.