JP2000164017A - Edge light type light guide plate and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high luminance with little color temperature irregularities in a thin and wide area, i.e., on a thin long optical path, by providing a light guide plate which is blended with a specific quantity of an antioxidant into an alicyclic structure-containing polymer resin and is fused and molded, and setting the longitudinal length of the light guide plate along the light incidence direction from a light source to a specific value. SOLUTION: An antioxidant 0.01-0.08 pts.wt. is blended into an alicyclic structure-containing polymer resin 100 pts.wt. The alicyclic structure-containing polymer resin has an alicyclic structure such as cycloalkane structure and cycloalkene structure in a principal chain and/or a side chain, and the cycloalkane structure is preferable in view of mechanical strength and heat resistance. The alicyclic structure having no norbornane cyclic structure is contained preferably at 10 wt.% or above, and an alkyl substituted phenol antioxidant is suitable for the antioxidant. The longitudinal length is set to 100 mm or longer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge light type light guide plate, and more particularly to a light guide plate in which incident light travels along an incident direction from a light incident surface which is an end face for receiving light from a light source. The present invention relates to an edge light type light guide plate having a high degree of transparency, with less color temperature unevenness over the entire surface of the light guide plate even if the length of the light guide plate in the longitudinal direction (hereinafter sometimes referred to as an optical path length) is long, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A light guide plate is one of optical members used for a planar light source device mounted on various display devices. For example, in an edge light type planar light source device, a light guide plate is provided from the side of the light guide plate. It has a function of guiding light emitted from a light source introduced into the light source while guiding the light in a direction perpendicular to the incident direction. Since the entire light exit surface of such a light guide plate serves as a direct light source for various display devices, it is necessary to form the light guide plate with a highly transparent material in order to achieve high luminance.

In recent years, as backlight units have become thinner and lighter year by year, the trend of light guide plates has also shifted to thinner and larger areas. Requirements for transparency tend to be higher. Normally, when the thin and large-area light guide plate is obtained by melt molding, it is necessary that the resin has sufficient fluidity at the time of melt molding.

[0004] However, if the melting temperature of the resin is too high in order to improve the fluidity of the resin, the resin itself in the molten state is thermally deteriorated and colored, and the resulting molded product is used as a light guide plate. May become unusable.

For example, when the melting temperature of a resin such as polycarbonate (PC) or polymethyl methacrylate (PMMA) generally used as a light guide plate is increased to increase fluidity, the resin is thermally decomposed or melted in a molding machine. There is a possibility that coloring or foaming may occur due to hydrolysis, and voids or the like are generated in the molded product, and the transparency is reduced.

On the other hand, polymer resins having an alicyclic structure such as a cycloolefin polymer are known to be excellent in transparency, fluidity during melt molding and heat resistance. It has been proposed to produce a light guide plate by melt molding a resin composition comprising, for example, 0.1 parts by weight of an antioxidant, in order to further effectively suppress oxidative deterioration and thermal deterioration in the combined resin. (JP-A-7-118,34)
No. 4, JP-A-8-94,852).

However, according to studies by the present inventors, although the light guide plates described in these publications have good optical characteristics in the case of a small size, if the optical path length becomes longer as a result of enlargement, the light guide plate A difference between the color temperature at the light exit surface near the light incident surface and the color temperature at the light exit surface near the longest optical path length, as a result,
In some cases, unevenness in color temperature and a reduction in luminance associated with the unevenness may occur. As described above, when the color temperature unevenness occurs on the entire surface of the light guide plate, the color appearance is disturbed, and the luminance is reduced accordingly, so that the light guide plate is not suitable for use.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an edge light type light guide plate having less color temperature unevenness and excellent brightness over the entire surface of the light guide plate even when the optical path length is long, and manufacturing thereof. The aim is to provide a method.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, the light absorption ability of the compounded antioxidant itself affects the color temperature unevenness in the light guide plate. In addition, it has been found that if a small amount of an antioxidant is added, thermal deterioration of the resin during melt molding can be effectively suppressed. As a result, it has been found that by controlling the amount of the antioxidant, a light guide plate can be obtained which is thin and has a wide area, that is, a thin and long light path, which can achieve high brightness with little color temperature unevenness. Was completed. That is, (1) The “edge light type light guide plate” according to the present invention has at least one light incident surface for receiving light from at least one light source on a side surface and reflects the incident light. In an edge light type light guide plate having a light reflection surface and an emission surface for emitting reflected light, the light guide plate may be 0.01 to 0.08 with respect to 100 parts by weight of the alicyclic structure-containing polymer resin. A resin composition obtained by blending parts by weight of an antioxidant is melt-molded, and the length of the light guide plate in the longitudinal direction along the light incident direction from the light source (optical path length)
Is 100 mm or more.

In the present invention, the compounding amount of the antioxidant is
The amount may be in the range of at least 0.01 to 0.08 parts by weight, preferably 0.02 to 0.07 parts by weight, more preferably 0.1 to 0.07 parts by weight, based on 100 parts by weight of the alicyclic structure-containing polymer resin. The amount is desirably from 03 to 0.06 parts by weight.

In the present invention, the length of the light guide plate in the longitudinal direction along the light incident direction from the light source (optical path length) may be at least 100 mm or more, and preferably 13 mm or more.
It is desirable that it is 0 mm or more, more preferably 150 mm or more.

(2) In the present invention, when the light guide plate obtained by melt-molding the above resin composition is dissolved in a solvent which is soluble at a concentration of 15% by weight, the light guide plate has a measurement length of 10 mm. It is desirable that the solvent has a ΔYI of 1.0 or less, preferably 0.8 or less, more preferably 0.7 or less with respect to the solvent. With the light guide plate made of such a resin composition, even when the optical path length is long, more excellent high brightness and less color temperature unevenness can be achieved over the entire light emitting surface of the light guide plate.

(3) The melt molding may be any of extrusion molding, press molding and injection molding.
The light guide plate made of the resin composition of the present invention is particularly preferable in the case of injection molding because the effect can be remarkable.

(4) The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer resin is at least 20% by weight, preferably at least 50% by weight, more preferably at least 70% by weight. Is desirable. This is because by setting the content within this range, the heat resistance during melt molding of the resin is improved.

(5) The alicyclic structure-containing polymer resin includes:
A norbornene-based polymer is desirable from the viewpoint of heat resistance of the resin, and a norbornene-based ring-opened polymer is more desirable from the viewpoint of heat resistance during melt molding of the resin and the strength of the obtained light guide plate. The hydrogenated product of the ring-opening polymer is more desirable from the viewpoint of heat resistance during melt molding of the resin.

(6) In the norbornene-based polymer, a repeating unit having an alicyclic structure having no norbornane ring structure in a repeating unit having an alicyclic structure is preferably at least 10% by weight, more preferably at least 10% by weight. It is desirable that the content be 20% by weight or more, more preferably 30% by weight or more. By having a repeating unit having an alicyclic structure having no norbornane ring structure in this range, fluidity of the resin,
This is because heat resistance during melt molding is improved.

(7) The hydrogenation rate of the hydrogenated norbornene ring-opening polymer is defined as 100% when all double bonds of the ring-opening polymer are saturated by hydrogenation. At least 99.0% of the unsaturated bonds of
It is desirable to hydrogenate 9.6% or more, particularly preferably 99.9% or more, from the viewpoint of heat resistance during melt molding of the resin.

(8) The weight average molecular weight (Mw) of the alicyclic structure-containing polymer resin was measured by gel permeation chromatography of a cyclohexane solution (a toluene solution when the polymer resin was not dissolved). In terms of polyisoprene, it is usually 5,000 to 500,000, more preferably 8,000 to 200,000, particularly preferably 1 to 500,000.
It is desirable to be in the range of 000 to 100,000 in view of the balance between melt moldability and heat resistance.

(9) The glass transition temperature (Tg) of the alicyclic structure-containing polymer resin is 70 ° C. or higher, preferably 8 ° C.
The temperature is preferably at least 0 ° C, more preferably at least 90 ° C, from the viewpoint of heat resistance when the resin is melted.

(10) JIS of the alicyclic structure-containing polymer resin at 280 ° C. under a load of 2.16 kgf
Melt flow rate (MF
R) is 10 (g / 10 min.) Or more, preferably 3
0 (g / 10 min.) Or more, particularly preferably 50 (g / 10 min.).
/ 10 min. The above value is preferable for obtaining a thin and large-area light guide plate that can sufficiently secure fluidity during melt molding.

(11) In the present invention, the cross-sectional shape of the edge light type light guide plate is preferably a wedge plate shape.

[0022]

According to the edge light type light guide plate of the present invention, the amount of the antioxidant is set in the above-mentioned specific range with respect to 100 parts by weight of the alicyclic structure-containing polymer resin. Thermal degradation can be suitably suppressed, and coloring of the light guide plate due to the light absorption ability of the antioxidant itself, particularly the absorption ability on the short wavelength side, can also be suppressed. If the compounding amount of the antioxidant is too small, the resin is liable to undergo thermal degradation during melt molding, leading to coloring of the light guide plate, which is not preferable.If it is too large, the antioxidant itself emits light from the light source. Light absorption ability to absorb the light to be emitted, in particular, the light absorption ability on the short wavelength side, so that the color temperature at the light emission surface near the light incident surface and the color temperature at the light emission surface near the longest optical path length This is not preferable because a difference is generated between the colors, resulting in unevenness in color temperature. The range of the amount of the antioxidant to be blended is a suitable range for highly balancing these characteristics and achieving a small color temperature spot and accompanying high luminance as a light guide plate. Therefore, according to the present invention, it is possible to provide a light guide plate having excellent optical characteristics, and it is particularly suitable for a light guide plate required to be thin and have a large area. In addition, if the resin composition of the specific composition of the present invention is used, particularly, 100 m
m or more, preferably 130 mm or more, more preferably 1 mm or more.
Even when used for a light guide plate having an optical path length of 50 mm or more, high brightness and little color temperature unevenness can be achieved over the entire light exit surface of the light guide plate.

[0023]

Embodiments of the present invention will be described below.

The alicyclic structure-containing polymer resin The alicyclic structure-containing polymer resin used in the present invention has an alicyclic structure in a main chain and / or a side chain, and has mechanical strength and heat resistance. From the viewpoint of properties and the like, those containing an alicyclic structure in the main chain are preferred.

Examples of the alicyclic structure of the polymer include a saturated cyclic hydrocarbon (cycloalkane) structure and an unsaturated cyclic hydrocarbon (cycloalkene) structure. From the viewpoint of mechanical strength and heat resistance, A cycloalkane structure or a cycloalkene structure is preferred, and a cycloalkane structure is most preferred.

The number of carbon atoms constituting the alicyclic structure is not particularly limited, but is usually 4 to 30, preferably 5 to 20.
When the number is in the range of 5 pieces, more preferably 5 to 15, the properties of mechanical strength, heat resistance and moldability are highly balanced and suitable.

The proportion of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer resin used in the present invention may be appropriately selected according to the purpose of use. Preferably at least 50% by weight, more preferably 7% by weight.
0% by weight or more. By setting the proportion of the repeating unit having an alicyclic structure to 20% by weight or more, heat resistance is improved, burning does not easily occur, and it is suitable for use in light guide plates.

Further, among the alicyclic structures in the alicyclic structure-containing polymer resin used in the present invention, those having a higher proportion of the repeating unit composed of an alicyclic structure having no norbornane ring structure are preferred. The light guide plate is preferable, and its ratio can be appropriately selected according to the purpose of use, but is preferably 10% by weight.
The above is more preferably 20% by weight or more, further preferably 30% by weight or more, and the upper limit is 100% by weight.

The remainder other than the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer resin is not particularly limited, and is appropriately selected depending on the purpose of use.

Specific examples of such a polymer resin having an alicyclic structure include (1) a norbornene-based polymer, (2) a monocyclic olefin-based polymer, and (3) a cyclic conjugated diene-based polymer. And (4) vinyl alicyclic hydrocarbon-based polymers, and hydrogenated products thereof. Among these, a norbornene-based polymer, a cyclic conjugated diene-based polymer and a hydrogenated product thereof are preferable, and a norbornene-based polymer having a repeating unit having an alicyclic structure having no norbornane structure and a cyclic conjugated diene-based polymer are preferable. A coalescence and a hydrogenated product thereof are more preferable, and a norbornene-based polymer having a repeating unit having an alicyclic structure having no norbornane structure is more preferable. A norbornene-based polymer is preferred because its use improves the heat resistance and mechanical strength of the molded article, and is therefore suitable for a thin-walled body.

(1) Norbornene-based polymer The norbornene-based polymer used in the present invention is not particularly limited. For example, JP-A No. 3-14,882,
It is a known polymer disclosed in JP-A-3-122137, and the like. Specific examples thereof include a ring-opened polymer of a norbornene-based monomer and a hydrogenated product thereof, an addition polymer of a norbornene-based monomer, and norbornene. An addition-type copolymer of a system monomer and a vinyl compound may, for example, be mentioned. Among them, in order to highly balance heat resistance and moldability,
A norbornene-based polymer having a repeating unit composed of an alicyclic structure having no norbornane ring structure is preferable. For example, a ring-opened polymer of a norbornene-based monomer having one norbornene ring structure and having no norbornane ring structure And a hydrogenated product thereof, and a hydrogenated product of a ring-opened polymer of a norbornene-based monomer having one norbornene ring structure and having no norbornane ring structure is particularly preferred.

Examples of the norbornene monomer having no norbornane ring structure include bicyclo [2.2.1] -hept-2-ene (common name: norbornene) and 5-methyl-
Bicyclo [2.2.1] -hept-2-ene, 5,5-
Dimethyl-bicyclo [2.2.1] -hept-2-ene, 5-ethyl-bicyclo [2.2.1] -hept-2
-Ene, 5-butyl-bicyclo [2.2.1] -hept-2-ene, 5-hexyl-bicyclo [2.2.1]-
Hept-2-ene, 5-octyl-bicyclo [2.2.
1] -Hept-2-ene, 5-octadecyl-bicyclo [2.2.1] -hept-2-ene, 5-ethylidene-
Bicyclo [2.2.1] -hept-2-ene, 5-methylidene-bicyclo [2.2.1] -hept-2-ene,
5-vinyl-bicyclo [2.2.1] -hept-2-ene, 5-propenyl-bicyclo [2.2.1] -hept-2-ene, 5-methoxy-carbonyl-bicyclo [2.2. 1] -Hept-2-ene, 5-cyano-bicyclo [2.2.1] -hept-2-ene, 5-methyl-
5-methoxycarbonyl-bicyclo [2.2.1] -hept-2-ene, 5-methoxycarbonyl-bicyclo [2.2.1] -hept-2-ene, 5-ethoxycarbonyl-bicyclo [2.2 .1] -hept-2-ene,
5-methyl-5-ethoxycarbonyl-bicyclo [2.
2.1] -Hept-2-ene, bicyclo [2.2.1]
-Hept-5-enyl-2-methylpropionate, bicyclo [2.2.1] -hept-5-enyl-2-methyloctanoate, bicyclo [2.2.1] -hept-2
-Ene-5,6-dicarboxylic anhydride, 5-hydroxymethyl-bicyclo [2.2.1] -hept-2-ene,
5,6-di (hydroxymethyl) -bicyclo [2.2.
1] -Hept-2-ene, 5-hydroxy-i-propyl-bicyclo [2.2.1] -hept-2-ene, bicyclo [2.2.1] -hept-2-ene, 5,6 -Dicarboxy-bicyclo [2.2.1] -hept-2-ene, bicyclo [2.2.1] -hept-2-ene-5,
6-dicarboxylic imide, 5-cyclopentyl-bicyclo [2.2.1] -hept-2-ene, 5-cyclohexyl-bicyclo [2.2.1] -hept-2-ene, 5
-Cyclohexenyl-bicyclo [2.2.1] -hept-2-ene, 5-phenyl-bicyclo [2.2.1]-
Hept-2-ene, tricyclo [4.3.0.1
^2,5 ] -deca-3,7-diene (common name dicyclopentadiene), tricyclo [4.3.0.1 ^2,5 ]
-Dec-3-ene, tricyclo [4.4.0.1
^2,5 ] -Undeca-3,7-diene or tricyclo [4.4.0.1 ^2,5 ] -undeca-3,8-
Diene and a these partially hydrogenated product (or an adduct of cyclopentadiene and cyclohexene), tricyclo [4.4.0.1 ^{2, 5]} - undec-3-ene, tetracyclo [7.4.0. 1 ^{10, 13} . 0
^2,7 ] -Trideca-2,4,6-11-tetraene (also referred to as 1,4-methano-1,4,4a, 9a-tetrahydrofluorene), tetracyclo [8.4.0.1
^11,14 . 0 ^3,8 ] -tetradeca-3,5
7,12-11-tetraene (1,4-methano-1,
Norbornene-based monomers such as 4,4a, 5,10,10a-hexahydroanthracene).

These norbornene monomers are used alone or in combination of two or more.

Norbornene having a norbornane ring structure
As the system monomer, tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene (simply tet
Lacyclododecene), 8-methyl-tetracycline
B [4.4.0.1^2,5. 1^7,10]-Dodeca-
3-ene, 8-methyl-tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene, 8-ethyl
Le-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-methylidene-tet
Lacyclo [4.4.0.1^2,5. 1^7,10] -Do
Dec-3-ene, 8-ethylidene-tetracyclo [4.
4.0.1.^2,5. 1^7,10] -Dodeka-3-e
8-vinyl-tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene, 8-pro
Phenyl-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-methoxycarboni
Le-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-methyl-8-metho
Xycarbonyl-tetracyclo [4.4.0.
1^2,5 . 1^7,10] -Dodeca-3-ene, 8-hide
Roxymethyl-tetracyclo [4.4.0.
1^2,5. 1^7,10] -Dodeca-3-ene, 8-ca
Ruboxy-tetracyclo [4.4.0.1^2,5. 1
^7,10] -Dodeca-3-ene, 8-cyclopentyl-
Tetracyclo [4.4.0.1^2,5. 1^7,10]
-Dodeca-3-ene, 8-cyclohexyl-tetracycline
B [4.4.0.1^2,5. 1^7,10] -Dodeca-3
-Ene, 8-cyclohexenyl-tetracyclo [4.
4.0.1.^2,5. 1^7,10] -Dodeka-3-e
8-phenyl-tetracyclo [4.4.0.1
^2,5. 1^7,10] -Dodeca-3-ene, pentacy
Black [6.5.1.1^3,6. 0^2,7. 0
^9,13] -Pentadeca-3,10-diene, pentacyclo
Black [7.4.0.1^3,6. 1^10,13. 0
^2,7] -Pentadeca-4,11-diene and other nor
Norbornene-based monomers with two or more bornene structures
Is mentioned.

These norbornene monomers having two or more norbornene structures are used alone or in combination of two or more.

The content of the norbornene-based monomer having one norbornane structure in the norbornene-based monomer may be appropriately selected according to a preferable ratio of the repeating unit having an alicyclic structure having no norbornane structure.
Usually 10% by weight or more, preferably 20% by weight or more, more preferably 30% by weight or more, and the upper limit is 100% by weight.
It is.

These ring-opening (co) polymers of norbornene-based monomers can be obtained by using a norbornene-based monomer as a ring-opening polymerization catalyst, such as a metal halide such as ruthenium, rhodium, palladium, osmium, iridium, or platinum;
Using a catalyst system comprising a nitrate or acetylacetone compound and a reducing agent, or a catalyst system comprising a halide or acetylacetone compound of a metal such as titanium, vanadium, zirconium, tungsten or molybdenum, and an organoaluminum compound in a solvent, Or without solvent, usually at a polymerization temperature of -50 ° C to 100 ° C,
It can be obtained by ring-opening (co) polymerizing at a polymerization pressure of 50 kg / cm ² .

The catalyst system includes molecular oxygen, alcohol, ether, peroxide, carboxylic acid, acid anhydride, acid chloride,
By adding a third component such as an ester, ketone, nitrogen-containing compound, sulfur-containing compound, halogen-containing compound, molecular iodine, or other Lewis acid, the polymerization activity and the selectivity of ring-opening polymerization can be increased.

In the present invention, the norbornene-based ring-opened polymer is partially or entirely saturated with olefinically unsaturated groups (such as a main chain double bond and an unsaturated ring double bond) in the molecule. Thereby, a hydrogenated norbornene ring-opening polymer can be obtained. Assuming that the hydrogenation rate is 100% when all the double bonds of the ring-opening polymer are saturated by hydrogenation, it is more necessary to improve heat resistance at the time of melt molding and to prevent burning from occurring. Higher is more preferable, and 99.0% or more, preferably 99.6% or more, particularly preferably 99.9% of the unsaturated bonds in the main chain structure.
It is desirable that the above be hydrogenated. Incidentally, unsaturated bonds other than the main chain structure are generally hydrogenated at a certain rate simultaneously with the unsaturated bonds of the main chain structure. By selecting a hydrogenation catalyst, an aromatic ring can be left as an unsaturated bond without selective hydrogenation. The hydrogenation rate can be determined by distinguishing the unsaturated bonds of the aromatic ring from other unsaturated bonds by infrared absorption spectrum or ¹ H-nuclear magnetic resonance spectrum.

The addition copolymer of a norbornene-based monomer and a vinyl-based compound can be prepared, for example, by adding a monomer component in a solvent or without a solvent in the presence of a catalyst system comprising a titanium, zirconium, or vanadium compound and an organoaluminum compound. In, usually, a polymerization temperature of -50 ° C ~ 100 ° C,
It can be obtained by a method of copolymerizing at a polymerization pressure of 0 to 50 kg / cm ² .

The vinyl compound is not particularly limited as long as it can be copolymerized. For example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1 -Butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl -1-pentene, 4
-Ethyl-1-hexene, 3-ethyl-1-hexene,
C2-C20 ethylene or α-olefins such as 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene; cyclobutene, cyclopentene, cyclohexene, 3,4 Cycloolefins such as -dimethylcyclopentene, 3-methylcyclohexene, 2- (2-methylbutyl) -1-cyclohexene, cyclooctene, 3a, 5,6,7a-tetrahydro-4,7-methano-1H-indene; Non-conjugated dienes such as 4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene;
Are used.

These vinyl compounds can be used alone or in combination of two or more.

(2) Monocyclic Cyclic Olefin Polymer Examples of the monocyclic cycloolefin polymer include, for example, cyclohexene, cycloheptene, cyclooctene and the like disclosed in JP-A-64-66,216. An addition polymer of a monocyclic cyclic olefin monomer can be used.

(3) Cyclic conjugated diene-based polymer As the cyclic conjugated diene-based polymer, for example, Japanese Unexamined Patent Publication No.
136,057 and JP-A-7-258,318, polymers obtained by 1,2- or 1,4-addition polymerization of cyclic conjugated diene-based monomers such as cyclopentadiene and cyclohexadiene; The hydrogenated product can be used.

(4) Vinyl alicyclic hydrocarbon polymer Examples of the vinyl alicyclic hydrocarbon polymer include vinyl cyclohexene and vinyl cyclohexane disclosed in JP-A-51-59,989. Polymers of vinyl alicyclic hydrocarbon monomers and hydrogenated products thereof, JP-A-63-43910, JP-A-64-1,706
For example, a hydrogenated product of an aromatic ring portion of a polymer of a vinyl aromatic monomer such as styrene and α-methylstyrene disclosed in Japanese Patent Application Laid-Open No. H10-260, etc. can be used.

The molecular weight of the alicyclic structure-containing polymer resin used in the present invention is appropriately selected according to the purpose of use.
Weight average molecular weight (M) in terms of polystyrene measured by gel permeation chromatography of a cyclohexane solution (a toluene solution when the polymer resin does not dissolve).
w), 5,000 or more, preferably 5,000 to 50
000, more preferably 8,000 to 200,00
When it is 0, particularly preferably in the range of 10,000 to 100,000, the mechanical strength and the formability are highly balanced and suitable.

The glass transition temperature (Tg) of the alicyclic structure-containing polymer resin used in the present invention may be appropriately selected according to the purpose of use, but is preferably higher from the usage environment of the light guide plate. When the temperature is usually 70 ° C. or higher, preferably 80 ° C. or higher, more preferably 90 ° C. or higher, the heat resistance at the time of melt molding and the moldability are highly balanced, which is preferable.

JI of the alicyclic structure-containing polymer resin used in the present invention at 280 ° C. under a load of 2.16 kgf
Melt flow rate (M
FR) may be appropriately selected depending on the purpose of use, but is usually 10 (g / 10 min.) Or more, preferably 30 (g).
/ 10 min. ) Or more, particularly preferably 50 (g / 10
min. The above is preferred. MFR of 10 (g / 10
min. The above makes it possible to improve the fluidity of the resin during melt molding, so that it is preferable to obtain a thin and wide area, that is, a light guide plate having a long optical path length, and it is possible to lower the molding temperature, Therefore, it is preferable because the occurrence of burning during melt molding is more easily suppressed.

These alicyclic structure-containing polymer resins can be used alone or in combination of two or more.

[0050] As the anti-aging agent used in anti-aging agent present invention, phenol-based antioxidant, phosphorus antioxidant, but like sulfur-based antioxidant, among these, a phenol-based antioxidant is Alkyl-substituted phenolic antioxidants are particularly preferred.

As the "phenolic antioxidant", conventionally known ones can be used. For example, 2-t-butyl-6
-(3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t-amyl-6- (1- (3,5-di-t-amyl-
JP-A-63-179953 and JP-A-Hei.
Acrylate compounds described in JP-B-168,643; octadecyl-3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate, 2,2′-
Methylene-bis (4-methyl-6-t-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2, 4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ′, 5′-di-t-butyl-4 ′)
-Hydroxyphenylpropionate) methane [that is, pentaerythrimethyl-tetrakis (3- (3,5
-Di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- (3-t
Alkyl-substituted phenolic compounds such as -butyl-4-hydroxy-5-methylphenyl) propionate);
6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3,5-triazine, 2- Octylthio-4,6-bis- (3,5-di-
triazine group-containing phenolic compounds such as t-butyl-4-oxyanilino) -1,3,5-triazine;

The "phosphorous antioxidant" is not particularly limited as long as it is one generally used in the general resin industry.
For example, triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-
Di-t-butylphenyl) phosphite, 10- (3,
5-di-t-butyl-4-hydroxybenzyl) -9,
Monophosphite compounds such as 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4′-butylidene-bis (3-methyl-6-
t-butylphenyl-di-tridecyl phosphite),
And diphosphite compounds such as 4,4 ′ isopropylidene-bis (phenyl-di-alkyl (C ₁₂ -C ₁₅ ) phosphite). Among these, a monophosphite compound is preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

Examples of the "sulfur anti-aging agent" include dilauryl 3,3-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3 , 3-thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate, 3,9-bis (2-dodecylthioethyl) -2,
4,8,10-tetraoxaspiro [5,5] undecane and the like.

These anti-aging agents are each used alone,
Alternatively, two or more kinds can be used in combination.
The compounding amount of the anti-aging agent is determined by the amount of the alicyclic structure-containing polymer resin 10.
0.01 to 0.08 parts by weight, preferably 0.02 to 0.07 parts by weight, more preferably 0.0 to 0 parts by weight with respect to 0 parts by weight.
It is desirably 3 to 0.06 parts by weight.

A light stabilizer can be used together with such an antioxidant.

As the “light stabilizer”, for example, 2, 2,
6,6-tetramethyl-4-piperidyl benzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl)- 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate, 4- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy ) -1- (2-
(3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2,6,6
-Hindered amine light stabilizers such as tetramethylpiperidine.

These light stabilizers can be used alone or in combination of two or more. The compounding amount of the light stabilizer is appropriately selected within a range not to impair the object of the present invention, but the alicyclic structure-containing polymer resin component 10
0.001 to 1 part by weight, preferably 0.005 to 0.5 part by weight, more preferably 0.01 to 0 part by weight.
~ 0.3 parts by weight.

Other Ingredients The alicyclic structure-containing polymer resin constituting the “edge light type light guide plate” of the present invention contains, in addition to the above-mentioned anti-aging agent and light stabilizer which is optionally added, If necessary,
Soft polymers, other polymers, and various compounding agents can be used alone or in combination of two or more.

The term "soft polymer" refers to a polymer having a glass transition temperature (Tg) of usually 30 ° C. or lower, a polymer having a plurality of Tg, or having both Tg and a melting point (Tm). In the case of a polymer, the lowest Tg is 30 °.
If it is C or less, it is included in the soft polymer.

Examples of such a soft polymer include (a) an olefin-based soft polymer mainly composed of α-olefins such as ethylene and propylene, (b) an isobutylene-based soft polymer mainly composed of isobutylene, and (c) butadiene. , A diene-based soft polymer mainly composed of a conjugated diene such as isoprene, (d) a cyclic olefin-based ring-opened polymer mainly composed of a cyclic olefin such as norbornene and cyclopentene, and (e) a soft weight having a silicon-oxygen bond as a skeleton. Coalescing (organic polysiloxane), (f) α, β-
A soft polymer mainly composed of unsaturated acids and their derivatives,
(G) a soft polymer mainly composed of an unsaturated alcohol and an amine or an acyl derivative or acetal thereof,
(H) a polymer of an epoxy compound, (i) a fluorine-based rubber,
(J) Other soft polymers.

Specific examples of these soft polymers include, for example, (a) liquid polyethylene, atactic polypropylene, 1-butene, 4-methyl-1-butene,
Homopolymers such as -hexene, 1-octene and 1-decene; ethylene / α-olefin copolymers, propylene / α-olefin copolymers, ethylene / propylene / diene copolymers (EPDM), ethylene / cyclic olefins And copolymers such as copolymers and ethylene / propylene / styrene copolymers.

Examples of (b) include polyisobutylene, isobutylene / isoprene rubber, and isobutylene / styrene copolymer.

(C) is a homopolymer of a conjugated diene such as polybutadiene or polyisoprene; butadiene / styrene random copolymer, isoprene / styrene random copolymer, acrylonitrile / butadiene copolymer, acrylonitrile / butadiene copolymer Unionized hydrogenated product, random copolymer of conjugated diene such as acrylonitrile / butadiene / styrene copolymer; butadiene /
Styrene block copolymer, styrene butadiene
Styrene block copolymer, isoprene styrene
Block copolymer, styrene, isoprene, styrene,
Examples include block copolymers of conjugated dienes and aromatic vinyl hydrocarbons such as block copolymers, and hydrogenated products thereof.

As (d), norbornene monomers such as norbornene, vinyl norbornene and ethylidene norbornene, or cyclobutene, cyclopentene,
Examples include a metathesis ring-opened polymer of a monocyclic olefin such as cyclooctene and a hydrogenated product thereof.

As (e), silicone rubbers such as dimethylpolysiloxane, diphenylpolysiloxane, dihydroxypolysiloxane and the like can be mentioned.

Examples of (f) include homopolymers of acrylic monomers such as polybutyl acrylate, polybutyl methacrylate, polyhydroxyethyl methacrylate, polyacrylamide, and polyacrylonitrile; acrylic monomers such as butyl acrylate / styrene copolymer; Copolymers with monomers are mentioned.

As (g), polyvinyl alcohol,
(Esterification) of polyvinyl acetate, polyvinyl polystearate, polyvinyl benzoate, polyvinyl maleate, etc.
Homopolymers of unsaturated alcohols; copolymers of (esterified) unsaturated alcohols such as vinyl acetate / styrene copolymers and other monomers, and the like.

As (h), polyethylene oxide,
Polypropylene oxide, epichlorohydrin rubber, and the like.

Examples of (i) include vinylidene fluoride rubber, ethylene tetrafluoride-propylene rubber, and the like.

Examples of (j) include natural rubber, polypeptides, proteins, and polyester thermoplastic elastomers, vinyl chloride thermoplastic elastomers, and polyamide thermoplastic elastomers described in JP-A-8-73709.

These soft polymers may have a crosslinked structure or may have a functional group introduced by modification.

The “other polymers” include polystyrene, poly (meth) acrylate, polycarbonate,
Resins such as polyester, polyether, polyamide, polyimide, and polysulfone; and the like. Each of these other polymers may be used alone or
A mixture of more than one species can be used. The ratio is
It is appropriately selected within a range that does not impair the purpose of the present invention.

The “various compounding agents” are not particularly limited as long as they are commonly used in the resin industry.
For example, alcoholic compounds, organic or inorganic fillers,
Other additives are included.

In particular, in the light guide plate of the present invention, it is preferable to add an anti-opacity agent as a compounding agent. However, various properties such as transparency, heat resistance, low water absorption, and strength of the polymer having an alicyclic structure are preferred. Those that can prevent cloudiness under high temperature and high humidity, for example, without impairing the characteristics are preferable. Examples of the anti-opacity agent include the above-mentioned soft polymer, alcoholic compound, organic filler, inorganic filler and at least one compound selected from the group consisting of compounds incompatible with the alicyclic structure-containing polymer resin, Among these, an alcoholic compound and a soft polymer are preferable, and a soft polymer is particularly preferable in order to highly balance the properties of the alicyclic structure-containing polymer and the anti-clouding property.

In the present invention, among the above soft polymers, the soft polymers (a), (b) and (c) are particularly preferred from the viewpoint of the prevention of white turbidity when the light guide plate is used in a moisture-resistant environment. This is preferable because of excellent transparency and dispersibility after the formation. Among them, the diene-based soft polymer (c) is preferable, and a hydrogenated product of the diene-based soft polymer in which the carbon-carbon unsaturated bond of the conjugated diene bond unit is hydrogenated is more preferable. Specific examples of such a soft polymer include, for example, a hydrogenated product of a homopolymer such as polybutadiene, a hydrogenated product of a random copolymer such as a butadiene / styrene copolymer; butadiene / styrene / block copolymer And hydrogenated block copolymers such as styrene / butadiene / styrene / block copolymers, isoprene / styrene / block copolymers, and styrene / isoprene / styrene / block copolymers.

In the present invention, the amount of the soft polymer is determined so that moisture resistance is imparted when the optical member is used in a moisture-resistant environment.
The weight ratio of the soft polymer to 00 parts by weight is preferably 0.01 to 5 parts by weight, more preferably 0.01 to 1 part by weight.

Examples of the “alcoholic compound” include compounds having at least one alcoholic hydroxyl group and at least one ether bond, compounds having at least one alcoholic hydroxyl group and at least one ester bond, and the like. No.

The compound having at least one alcoholic hydroxyl group and at least one ether bond includes at least one alcoholic hydroxyl group other than a phenolic hydroxyl group and at least one ether bond unit in the molecule. There is no particular limitation as long as it is an organic compound having For example, a partial ether compound in which a part of hydroxyl groups is etherified, such as a polyhydric alcohol having preferably 2 or more hydroxyl groups, and more preferably a polyhydric alcohol having 3 to 8 hydroxyl groups, may be mentioned.

The compound having at least one alcoholic hydroxyl group and at least one ester bond includes at least one alcoholic hydroxyl group that is not a phenolic hydroxyl group and at least one ether bond unit in the molecule. There is no particular limitation as long as it is an organic compound having two or more compounds. For example, a partial ester compound in which a part of hydroxyl groups is esterified, such as a polyhydric alcohol having preferably 2 or more hydroxyl groups, and more preferably a polyhydric alcohol having 3 to 8 hydroxyl groups, may be mentioned.

Examples of the dihydric or higher polyhydric alcohol include polyethylene glycol, glycerol, trimethylolpropane, pentaerythrol, diglycerol, triglycerol, dipentaerythol,
6,7-trihydroxy-2,2-di (hydroxymethyl) -4-oxoheptane, sorbitol, 2-methyl-1,6,7-trihydroxy-2-hydroxymethyl-4-oxoheptane, 1,5 , 6-trihydroxy-
3-oxohexanepentaerythritol, tris (2-
Hydroxyethyl) isocyanurate, among which trihydric or higher polyhydric alcohols,
Polyhydric alcohols having up to 8 hydroxyl groups are preferred. In order to obtain a partially esterified product, glycerol, diglycerol, triglycerol, and the like, from which a partially esterified product containing α, β-diol can be synthesized, are preferable.

Examples of such partially etherified or partially esterified products include, for example, glycerin monostearate, glycerin monolaurate, glycerin monobehenate, diglycerin monostearate, glycerin distearate, glycerin dilaurate, Esterified products of polyhydric alcohols such as pentaerythritol monostearate, pentaerythritol monolaurate, pentaerythritol beherate, pentaerythritol dilaurate, pentaerythritol tristearate, dipentaerythritol distearate, and the corresponding etherified products; 3- (octyloxy)-
1,2-propanediol, 3- (lauryloxy)-
1,2-propanediol, 3- (4-nonylphenyloxy) -1,2-propanediol, 1,6-dihydroxy-2,2-di (hydroxymethyl) -7- (4-
Nonylphenyloxy) -4-oxoheptane, an etherified product obtained by reacting a condensate of p-nonylphenyl ether and aldehyde with glycidol, an ether obtained by reacting a condensate of p-octylphenyl ether and dicyclopentadiene with glycidol And the like.

The molecular weight of these alcoholic compounds is
Although not particularly limited, it is usually 100 to 3,000, preferably 200 to 2,000, more preferably 300 to 1,
When it is in the range of 500, the transparency and the effect of preventing white turbidity are highly balanced and suitable.

As the “organic or inorganic filler”,
If it is commonly used in the polymer industry,
There is no particular limitation.

As the organic filler, ordinary organic polymer particles or crosslinked organic polymer particles can be used.
Specifically, for example, polyethylene, polypropylene,
Polyolefins such as polymethyl-1-butene, poly-4-methyl-1-pentene and poly1-butene; halogen-containing vinyls such as polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polyvinylidene fluoride, polychloroprene, and chlorinated rubber Polymers: α, β- such as polyarylate, polymethacrylate, polyacrylamide, polyacrylonitrile, acrylonitrile / butadiene / styrene copolymer, polyacrylonitrile, acrylonitrile / styrene / acrylate (co) polymer, etc.
(Co) polymers derived from unsaturated acids or derivatives thereof; polyvinyl alcohol, polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl maleate, polyvinyl bityral, polyallyl phthalate, polyallyl melatin, Polymers derived from unsaturated alcohols and amines or acyl derivatives or acetal thereof, such as ethylene-vinyl acetate copolymer; polyethylene oxide, or polymers derived from bisglycidyl ether; polyphenylene oxide;
Polycarbonate; Polysulfone; Polyurethane;
And urea resins; polyamides such as nylon 6, nylon 66, nylon 11, and nylon 12; polyesters such as polyethylene terephthalate, polybutylene terephthalate, and poly-1,4-dimethylol / cyclohexane terephthalate; phenol / formaldehyde resins, urea / formaldehyde resins, and melamine. A polymer having a crosslinked structure derived from an aldehyde such as a formaldehyde resin and phenol, urea or melamine, for example, natural polymer compounds such as cellulose acetate, cellulose propionate and cellulose ether; be able to.

Inorganic fillers include Group 1, Group 4, Group 4, and 6
Oxides, hydroxides, sulfides, nitrides of the elements of Group 7, Group 7, 8 to 10, Group 11, Group 12, 13 or 14;
Halides, carbonates, sulfates, acetates, phosphates, phosphites, organic carboxylates, silicates, titanates, borates, and hydrated compounds thereof, and composite compounds containing these compounds, Natural mineral particles with a chemical composition.

Specifically, Group 1 element compounds such as lithium fluoride and borax (sodium borate hydrate); magnesium carbonate, magnesium phosphate, magnesium oxide, magnesium chloride, magnesium acetate, magnesium fluoride, magnesium titanate, silicate Magnesium, magnesium silicate hydrate (talc), calcium carbonate, calcium phosphate, calcium phosphite, calcium sulfate (gypsum), calcium acetate, calcium terephthalate, calcium hydroxide, calcium silicate, calcium fluoride, calcium titanate, titanic acid Group 2 element compounds such as strontium, barium carbonate, barium phosphate, barium sulfate, barium phosphite; titanium dioxide (titania), titanium monoxide, titanium nitride, zirconium dioxide (zirconia), zirconium monoxide Group 6 element compounds such as molybdenum dioxide, molybdenum trioxide and molybdenum sulfide; Group 7 element compounds such as manganese chloride and manganese acetate; Group 8-10 element compounds such as cobalt chloride and cobalt acetate; Group 11 element compounds such as cuprous chloride; Group 12 element compounds such as zinc oxide and zinc acetate; Group 13 element compounds such as aluminum oxide (alumina), aluminum fluoride, and aluminosilicate (alumina silicate, kaolin, kaolinite) Group 14 element compounds such as silicon oxide (silica, silica gel), graphite, carbon, graphite, glass;
Examples include particles of natural minerals such as kainite, mica (mica, kinmo) and virose ore.

The compound incompatible with the alicyclic structure-containing thermoplastic resin is a compound other than the alcoholic compound, the filler and the soft polymer, and is incompatible with the alicyclic structure-containing thermoplastic resin. It is a compatible compound. The compound incompatible with the alicyclic structure-containing thermoplastic resin is not particularly limited as long as it is an incompatible compound that is not completely dissolved in the alicyclic structure-containing thermoplastic resin. The incompatibility is determined according to the ordinary method in the resin industry. For example, with respect to 100 parts by weight of the alicyclic structure-containing thermoplastic resin, a molded product obtained by melting and mixing 5 parts by weight of a compound is observed with an electron microscope at a magnification of 100,000 times,
Those having at least one domain or particle of 1 mm ² or more in the area of 10 cm × 15 cm can be defined as incompatible.

As the incompatible compound, other resins other than the alicyclic structure-containing thermoplastic resin are usually used.
Other resins incompatible with the alicyclic structure-containing thermoplastic resin include, for example, polyphenylene sulfide, polyether such as polyphenylene ether or polythioether; aromatic polyester, polyarylate, polyethylene terephthalate, polybutylene terephthalate,
Polyester polymers such as polycarbonate and polyether ketone; linear polyolefin polymers such as polyethylene, polypropylene and poly-4-methyl-pentene-1; polymethyl methacrylate, cyclohexyl methacrylate and methyl methacrylate copolymer, polyacrylonitrile styrene ( General-purpose transparent resin such as AS resin); acrylic resin; MS resin;

When an incompatible compound is added to these alicyclic structure-containing thermoplastic resins, a large number of dispersed microdomains are often formed in a molded article. In the case of forming a microdomain, the average particle diameter [(major axis + minor axis) / 2] of the domain observed with an electron microscope is usually 0.001.
When the size is from 0.5 to 0.5 μm, preferably from 0.005 to 0.3 μm, and particularly preferably from 0.01 to 0.2 μm, the transparency of the molded product and the effect of preventing cloudiness in a high-temperature and high-humidity environment are reduced. Highly balanced and preferred.

The refractive index of the light-transmitting one of these anti-opacity agents may be appropriately selected according to the purpose of use.
The difference between the refractive index of the alicyclic structure-containing thermoplastic resin is usually 0.5 or less, preferably 0.2 or less, and more preferably 0.1 or less. The prevention is highly balanced and suitable.

These anti-opacity agents are each used alone.
Alternatively, two or more kinds can be used in combination. The blending ratio of the anti-opacity agent may be appropriately selected within a range in which the anti-opacity effect can be exerted, but is usually 0.01 to 10 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the alicyclic structure-containing thermoplastic resin. Is 0.01 to 5 parts by weight, more preferably 0.01 to 1 part by weight, heat resistance,
The transparency and the effect of preventing white turbidity in a high temperature and high humidity environment are highly balanced and suitable.

The “other compounding agents” are not particularly limited as long as they are commonly used in the resin industry. For example, ultraviolet absorbers, near infrared absorbers, coloring agents such as dyes and pigments, plasticizers And a fluorescent whitening agent.

Examples of the "UV absorber" include a benzotriazole UV absorber; a benzoate UV absorber; a benzophenone UV absorber; an acrylate UV absorber; and a metal complex UV absorber.

Examples of the “near-infrared absorbing agent” include a cyanine-based near-infrared absorbing agent; a pyrylium-based infrared absorbing agent; a squarylium-based near-infrared absorbing agent; a croconium-based infrared absorbing agent;
Phthalocyanine-based near-infrared absorber; dithiol metal complex-based near-infrared absorber; naphthoquinone-based near-infrared absorber; anthraquinone-based near-infrared absorber; indophenol-based near-infrared absorber;
And the like.

The “dye” is not particularly limited as long as it can be uniformly dispersed and dissolved in the polymer component, but oil-soluble dyes (various CI solvent dyes) are widely used.

Examples of the “pigment” include diarylide pigments; azo lake pigments; condensed azo pigments; penzimidazolone pigments; quinacridone pigments; perylene pigments; and anthraquinone pigments.

When the light guide plate of the present invention needs to be colored, any of dyes and pigments can be used within the scope of the present invention, and is not limited, but microscopic optical characteristics become a problem. In the case of such a light guide plate, coloring with a dye is preferable. Also, the ultraviolet absorber may show a yellow to red color visually, and the near infrared absorber may show a black color visually, so there is no need to use these dyes strictly distinguished from each other. Further, they may be used in combination.

Examples of the "plasticizer" include a phosphate triester plasticizer; a phthalate ester plasticizer; a fatty acid monobasic ester plasticizer; a dihydric alcohol ester plasticizer; an oxyacid ester plasticizer; And the like. Further, as a plasticizer, squalane (C
₃₀ H ₆₂ , Mw = 422.8), liquid paraffin (white oil, ISO specified in JIS-K2231)
VG10, VG15, ISO VG32, ISO V
G68, ISO VG100, VG8 and VG21), polyisobutene, hydrogenated polybutadiene, hydrogenated polyisiprene and the like. Among them, squalane, liquid paraffin and polyisobutene are preferred.

The method of mixing the alicyclic structure-containing polymer resin with the above-mentioned antioxidant and other components is such that these compounding agents are sufficiently dispersed in the alicyclic structure-containing polymer resin component. If so, there is no particular limitation. For example, a method of kneading a resin in a molten state with a mixer, a twin-screw kneader, a roll, a Brabender, an extruder, or the like, dissolving and dispersing in a suitable solvent, coagulating, casting, or directly drying a solvent. There is a method of removing. In the case of using a twin-screw kneader, after kneading, the mixture is usually extruded into a rod in a molten state, cut into a suitable length by a strand cutter, and pelletized.
The molding method of the "edge light type light guide plate" comprising the alicyclic structure-containing polymer resin composition of the present invention is preferably melt molding, and includes extrusion molding, press molding, and injection molding. Molding is preferable from the viewpoint of moldability and productivity.

In the present invention, the “resin temperature” in the mold during injection molding is usually 150 to 400 ° C., preferably 180 to 360 ° C., more preferably 190 to 330 ° C.
C, particularly preferably in the range of 200 to 300 ° C. If the resin temperature is too low, the fluidity will deteriorate, and the light guide plate will have sink marks and distortion.If the resin temperature is too high, silver streaks will occur due to thermal decomposition of the resin, and the light guide plate will turn yellow. Failure may occur.

For the purpose of minimizing the above-mentioned molding failure, the alicyclic structure-containing polymer resin composition before molding is usually prepared in advance within usually 6 hours, preferably within 4 hours, more preferably within 2 hours. And "preliminary drying".

The “mold temperature” is usually set at a temperature lower than the Tg of the alicyclic structure-containing polymer resin, and is preferably 0 to 100 ° C. lower than the Tg of the alicyclic structure-containing polymer resin.
In the lower range, more preferably 20 to 60 lower than Tg.
It is set at a temperature in the range of ° C lower. By setting the mold temperature in this range, distortion of the light guide plate to be formed can be favorably suppressed.

The “injection speed” is usually 10 to 200 cm
³/ Sec, preferably 20 cm ³/ Sec-10
0cm³/ Sec. Injection speed 10cm³/
sec or more, a relatively large screen size (1
(0 inch or more) can be molded with high surface accuracy
Easier and also 200cm³/ Sec or less
This reduces the risk of resin decomposition due to shear heat.
Good light guide plate with little silver streak
Can be obtained.

The “injection pressure” may be appropriately determined in consideration of the design of the mold, the flowability of the alicyclic structure-containing polymer resin to be used, and the like, and is usually 100 kgf / cm ² to 1,
500 kgf / cm ² , preferably 500 kgf / c
m ^{2 to} 1,300 kgf / cm ² . When the injection pressure is in this range, the molding material (polymer resin composition having an alicyclic structure) is less likely to be decomposed due to shear heat generation, and a good light guide plate can be obtained.

The “holding pressure” means that the mold is substantially filled by the injection pressure.
After filling, the mold gate is completely cooled and solidified.
Pressure applied for a certain period of time. The upper limit of the holding pressure
Is generally set within the range of the mold clamping pressure.
Always 2000kgf / cm² Below, preferably 1700
kgf / cm²Or less, more preferably 1500 kgf
/ Cm²The range is as follows. The upper limit of holding pressure is
In this case, molding defects such as distortion may occur in the light guide plate.
There is no risk of production. As the lower limit of holding pressure,
At least 100kgf / cm²Above, preferably 120
kgf / cm ²Above, more preferably 150 kgf /
cm²This is the above range. The lower limit of the holding pressure
By setting the range, the occurrence of sink marks on the light guide plate is prevented,
Light shrinkage ratio can be reduced and light guide plate with excellent dimensional accuracy can be obtained.
Can be

[0106] In the edge light type light guide plate present invention an "edge light type light guide plate" has at least one light entrance surface for entering light from the at least one light source on a side surface, reflects the incident light Means a light guide plate having a light reflection surface for emitting light and an emission surface for emitting reflected light, and includes all light guide plates of an edge light type in addition to a single light type, a double light type and the like.

The “shape” of the light guide plate is not particularly limited, and may be a flat plate, a wedge plate, or another shape. This is preferable in terms of effective use of light. In this case, the tip of the wedge may be flat, curved, or substantially not form a surface, but a flat surface is preferable for effective use of light. In addition, the so-called two-lamp wedge-shaped edge light light guide plate, which is formed by arranging the wedge plate shapes so that the thin portions thereof face each other and providing two light sources on the left and right light incidence surfaces, is also available. It is included in the edge light type light guide plate of the present invention.

Light guide plates include, for example, personal computers such as laptops, notebooks, books and palmtops, OA equipment such as word processors, home appliances such as liquid crystal televisions for wall mounting, illumination signs,
It is used for a planar light source device used as a backlight for a light table, a viewer and other display devices.

Preferred Embodiment of the Present Invention In the present embodiment, a light guide plate (edge light type light guide plate) used in an edge light type planar light source device will be described with reference to the following examples. FIG. 1 is a schematic perspective view showing an outline of a light guide plate used in an edge light type planar light source device of various display devices and a planar light source device incorporating the light guide plate.

As shown in FIG. 1A, for example, as shown in FIG. 1A, the edge light type planar light source device 10 comprises: a light guide plate 100 for guiding a light source incident from a light incident surface 100a in a longitudinal direction and emitting the light; A light source 200 such as a cold-cathode tube disposed on at least one side of
0, the light source side end surface 10 of the light guide plate 100
A light reflector 300 for efficiently guiding the light source light not directly incident on the light guide plate 0a to the light guide plate 100;
A light diffusion sheet 400 disposed on the side of the light exit surface 100b of the light guide plate 100 as needed to diffuse light emitted from the exit surface 100b, and a light reflection surface 100c of the light guide plate 100.
And a reflection sheet 500 for returning light leaked from the light guide plate 100 into the light guide plate 100 again.

The light guide plate 100 in this embodiment is similar to the light guide plate shown in FIG.
As shown in (B), the cross section becomes wedge-shaped so that the light emitted from the emission surface 100b becomes thinner as the distance from the light source 200 increases, so that the light emitted from the emission surface 100b becomes uniform as a whole. The incident angle θ1 (see FIG. 1C) of the light emitting device 100 with respect to the outside of the emission surface 100b is set to be larger than the critical angle (the minimum incident angle at which total reflection occurs). In the present invention, the light guide plate has a thickness of the surface 100a based on the incident surface of 5 mm or less, preferably 0.1 to 4 mm, and more preferably 0.3 to 3 mm. Thickness 4
mm or less, preferably 0.05 to 3 mm, more preferably 0.1 to 2 mm. The area ratio between the entrance surface and the exit surface is 1/5 to 1/5 based on the ratio of the entrance surface / the exit surface.
00, preferably 1/10 to 1/400, more preferably 1/15 to 1/300. Further, a light guide plate having a diagonal length of the exit surface of usually 1 to 50 inches, preferably 5 to 40 inches, more preferably 1 to 30 inches, and particularly preferably 14 to 25 inches can be expected to have more effect.

In the present embodiment, as shown in FIG. 1C, the light introduced from the light source 200 is uniformly emitted on the back surface of the light guide plate 100 and on the light reflection surface 100c side of the light guide plate 100. In addition, a pattern consisting of a V-groove 1001 elongated in a direction substantially perpendicular to the direction away from the light source 200 side (a direction substantially parallel to the axis of the linear light source) is formed on the light guide plate 10.
A mold that can obtain a light guide plate that is provided so as to be gradually denser or deeper in the groove from the light source side of 0 to the end portion is used.

In this embodiment, adjacent V-grooves 1001
The pitch Pc (see FIG. 1D) between 10 and 5,000
0 μm, preferably 30 to 1,000 μm, more preferably 50 to 500 μm. Also, V
The height H of the groove is 10 to 5,000 μm, preferably 3 μm.
0 to 1,000 μm, more preferably 50 to 500 μm
It is desirable that Further, the pitch Pc on the 100d side of the light guide plate 100 between the V grooves 1001 is preferably 0.5 to 50% smaller than the pitch Pc on the 100a side.

In this embodiment, the light guide plate 100 is used in an amount of 0.01 parts by weight based on 100 parts by weight of the alicyclic structure-containing polymer resin.
A resin composition containing an antioxidant in an amount of 15 parts by weight to 0.08 part by weight. When the resin composition is dissolved in a solvent at a concentration of 15% by weight, a measurement length of 10% with respect to the solvent is obtained.
The resin composition having a specific composition having a ΔYI of 1.0 or less in mm is injection molded. Furthermore, the light guide plate 100 has a longitudinal direction X in a direction away from the vicinity of the light source 200 side (a direction substantially perpendicular to the axis of the linear light source).
Is 100 mm or more.

The color temperature unevenness of the light guide plate 100 having such a configuration is desirably 1500 K (Kelvin) or less, preferably 1200 K or less, more preferably 1,000 K or less on the light emitting surface 100 b. When the color temperature unevenness is in this range, the function as the light guide plate is properly exhibited. Further, the average color temperature at the light exit surface 100b of the light guide plate 100 (what color the light exit surface 100b of the light guide plate 100 has in terms of temperature (K: Kelvin)) is 6,000K or more. Preferably 6,500K
It is more desirable that the temperature be 7,000K or more. When the average color temperature is in this range, sufficient luminance and visibility as a light guide plate can be obtained.

Since the light guide plate 100 of the present embodiment is composed of a resin composition in which an alicyclic structure-containing polymer resin and an antioxidant are blended in a specific composition, transparency, moldability and meltability are improved. It has excellent heat resistance during molding, and is less likely to cause oxidative degradation and thermal degradation. In particular, it is preferable to apply to a thin and large-area light guide plate as in the present embodiment. When the resin composition used in the present embodiment is dissolved in a solvent at a concentration of 15% by weight, the resin composition has a ΔYI of 1.0 or less at a measurement length of 10 mm with respect to the solvent. Even if the light guide plate 100 made of the composition has a long optical path length of 100 mm or more, high brightness and little color temperature unevenness can be achieved over the entire light exit surface 100b of the light guide plate 100.

[0117]

EXAMPLES Hereinafter, the present invention will be described based on more detailed examples in comparison with comparative examples, but the present invention is not limited to these examples. In the following examples, “parts” and “%” are based on weight unless otherwise specified.

In the following Production Examples, Examples and Comparative Examples, the methods for measuring various physical properties are as follows.

(1) Regarding the physical properties of the resin, the weight average molecular weight (Mw), the hydrogenation rate of the main chain and the aromatic ring (nuclear hydrogenation rate), the glass transition temperature (Tg), the transparency and the refractive index were measured. . Here, "Mw" was measured as a polyisoprene conversion value by gel permeation chromatography (GPC) using cyclohexane as a solvent unless otherwise specified. "The hydrogenation rate of the main chain and the aromatic ring (nuclear hydrogenation rate)" was measured by ¹ H-NMR. "Tg"
Was measured based on JIS-K7121. "Refractive index"
Was measured according to ASTM-D542.

(2) "Transparency" was measured using a spectrophotometer (product number U-30 manufactured by JASCO Corporation) at a wavelength of 400 to 90.
The light transmittance (%) was measured while continuously changing the wavelength in the range of 0 nm, and the minimum transmittance was measured as the light transmittance of the light guide plate.

(3) “Yellowness index difference (ΔYI)” refers to the yellowness index of a test solution obtained by dissolving a part of a molded light guide plate at a concentration of 15% by weight in a soluble solvent. Index (Y
I: yellow index) according to JIS-K7103, using a colorimeter color analyzer with a measurement optical path 10
mm; blank: measured as a solvent for dissolution, and the value obtained by subtracting the YI value of only the blank solvent from the measured YI value was determined as the ΔYI value derived from the molded light guide plate. In addition, the measurement was performed three times and evaluated using the average value. Also, whether the solution was completely dissolved or not was determined by 0.5 μm P
The solution was filled into a syringe having a TFE filter attached to the tip, and it was confirmed that all the liquid was discharged from the tip of the filter without resistance when the piston was pressed. △ YI
Is less than 0.7, “◎ (very good)”, ΔYI is 0.7 or more and less than 1.0, “○ (good)”, ΔYI
Is not less than 1.0 and less than 1.5, "△ (somewhat bad)"
A case where ΔYI was 1.5 or more was evaluated as “× (defective)”.

(4) The "color temperature" is measured using a luminance meter (BM-7:
Using Topcon Corporation, the color temperature (vertical direction) of 9 light-emitting surfaces was measured in the same manner, and the average value was 6,
500K (Kelvin; the same applies hereinafter) to 7,500K: "A", 6,000K to 7,000K: "O", 6,0
Less than 00K was evaluated as "x". The higher the color temperature, the better the light guide plate without affecting the appearance.

(5) The “color temperature unevenness” means that the light guide plate is kept for one hour after the lamp is turned on, and the light emitting surface is uniformly spaced in the axial direction of the light source within 0.5 cm from the end of the light source side light guide plate. A total of 6 points were measured: 3 points and 3 points equidistant in the direction of the light source within 0.5 cm from the opposite end.
The maximum value-minimum value was evaluated, and 1,000 K (Kelvin) or less was evaluated as “◎ (very good)”, and 1,500 K or less as “「 ”.
(Good), more than 1,500 K and less than 2,000 K, “Δ (somewhat bad)”, and more than 2,000 K, “x (bad)”.

(6) “Brightness” means that the formed light guide plate was turned on for one hour after the lamp was turned on, and then the long side of the light emitting surface (a rectangular surface 0.5 cm inside the periphery of the light guide plate forming surface) was obtained. Luminance of a total of 9 points at equal intervals to the short side (vertical direction)
Was measured using a luminance meter (BM-7: manufactured by Topcon Corporation), and the average was calculated.

(7) “Luminance unevenness” is measured at 6 points (vertical direction) in the same manner as in the above (5), and evaluated by luminance unevenness = (minimum value / maximum value). Was regarded as good.

(8) "Moldability" was evaluated by visually judging a molded product (light guide plate) according to the following criteria. No appearance defects such as foaming, sink marks and silver streaks in 10 injection moldings "O", 10 or more injection moldings with 1-2 moldings showing the above molding failure "△", 10 injections "X", in which the above molding failure is observed in three or more samples in molding
And

Reference Example 1 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -dodeca-3
1-hexene 1 obtained by diluting 100 parts by weight of -ene (hereinafter abbreviated as ETCD) with 250 parts by weight of dehydrated cyclohexane in a nitrogen atmosphere and 10 parts by weight of cyclohexane as a molecular weight modifier with a known metathesis ring-opening polymerization catalyst system .2
Polymerization was carried out in the presence of 0 parts by weight, followed by hydrogenation by a known method to obtain a hydrogenated ETCD ring-opened polymer. This ETC
Mw of the hydrogenated D-ring-opened polymer was 29,500, the hydrogenation rate was 99.9%, Tg was 140 ° C, and the refractive index was 1.
53.

[Reference Example 2] Instead of 100 parts by weight of ETCD, 15 parts by weight of ETCD and tricyclo [4.3.0.
1 ^2,5 ] deca-3,7-diene (dicyclopentadiene; hereinafter, referred to as DCP) was replaced with 85 parts by weight (100 parts by weight in total) in the same manner as in Production Example 1 except that ETCD /
A hydrogenated DCP ring-opening copolymer was obtained. The copolymerization ratio of each norbornene in the polymer is determined by the composition of the residual norbornene in the solution after polymerization (by gas chromatography).
ETCD / DCP = 15/85, which was almost equal to the charged composition. The hydrogenated ETCD / DCP ring-opening polymer had a Mw of 29,500, a hydrogenation rate of 99.9%, a Tg of 104 ° C., a refractive index of 1.53,
Met.

[Reference Example 3] 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2.5 . 1
^7.10 ] 100 g of dodeca-3-ene (hereinafter also referred to as MMTCD), 60 g of 1,2-dimethoxymethane, 240 g of cyclohexane, 7 g of 1-hexene, and 0.96 mol / l of diethylaluminum chloride in toluene. 4 ml was added to a 1-liter autoclave. On the other hand, another vessel was mixed with 20 ml of a 0.05 mol / l 1,2-didimethoxyethane solution of tungsten hexachloride and 10 ml of a 0.1 mol / l 1,2-didimethoxyethane solution of paraaldehyde. 4.9 ml of this mixture was added to the mixture in the autoclave. The mixture was heated to 80 ° C. and stirred for 2.5 hours. To the obtained polymer solution was added a mixed solvent of 1/8 (weight ratio) of 1,2-didimethoxyethane and cyclohexane to make the polymer / solvent 1/10 (weight ratio), and then 20 g of triethanolamine. Was added and stirred for 10 minutes. 500 g of methanol was added to the polymerization solution, and the mixture was stirred for 30 minutes and allowed to stand. The upper layer separated into two layers was removed, methanol was added again, the mixture was stirred, allowed to stand, and the upper layer was removed. The same operation was further repeated twice, and the lower layer obtained was appropriately diluted with cyclohexane and 1,2-didimethoxyethane to obtain a cyclohexane-1,2-didimethoxyethane solution having a polymer concentration of 10%. To this solution, 2 kg of palladium / silica magnesia (manufactured by Nikki Chemical Co., Ltd., palladium amount = 5%) was added, and the hydrogen pressure was set to 40 k in an autoclave.
The reaction was performed at 165 ° C. for 4 hours at g / cm ² . The hydrogenation catalyst was removed by filtration to obtain a hydrogenated polymer solution. The hydrogenated polymer had a Mw of 31,000, a hydrogenation rate of 99.5%, a Tg of 167 ° C., and a refractive index of 1.51.
Met.

Example 1 To 100 parts of hydrogenated ETCD ring-opening polymer of Reference Example 1,
0.025 parts by weight of a phenolic antioxidant (pentaerythrityl-tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate)) and a hydrogenated styrene / butadiene / styrene block copolymer (ToughTech H1051, manufactured by Asahi Kasei Corporation)
0.1 parts by weight of a crumb-shaped, 30 ° C refractive index 1.52) was added, and a twin-screw kneader (manufactured by Toshiba Machine Co., Ltd., TEM-3)
5B, screw diameter 37 mm, L / D = 32, screw rotation speed 250 rpm, resin temperature 240 ° C., feed rate 10 kg / hour), extruded and pelletized. A light guide plate was obtained by injection molding the pellet. The molding conditions for the injection molding were as follows: using an injection molding machine of product number IS450 manufactured by Toshiba Machine Co., Ltd.
0 ° C, cylinder temperature 290 ° C, nozzle temperature 260
° C, injection pressure 1,000 kgf / cm ² , holding pressure 800
kgf / cm ² , mold clamping pressure 1200 kgf / cm ² ,
Injection speed (corresponding to screw advance speed) 40 cm ³
/ S.

As shown in FIG. 1, the obtained light guide plate had a thickness at one end (100a side) of 2 mm and a terminal side (100b).
Side) has a thickness of 0.5 mm, a length from one end to the end (length in the longitudinal direction from the light source to the light guide plate) is 190 mm, and a length along the axial direction of the linear light source is 250 mm. It was wedge-shaped so that the thickness gradually decreased in the direction away from the side to the terminal side (direction substantially perpendicular to the axis of the linear light source). In addition, the light guide plate has a light reflecting surface 100c that is elongated in a direction substantially perpendicular to the direction away from the light source 200 (in a direction substantially parallel to the axis of the linear light source), and that is located from one end to the end of the light guide plate. The V-shaped groove 1001 that gradually becomes denser as the distance increases is formed well without transfer failure. The shape of the V-groove has a vertex angle of 110 ° C., a pitch width near the light source of 0.3 to 1.5 mm, and a pitch width near the end of 0.0.
3 to 0.06 mm, and the depth of the groove was uniformly 80 μm. When the light transmittance of the light guide plate was measured, it was 400
The minimum light transmission from 9 nm to 900 nm is 92.0
%, And the transparency was good.

An edge light type planar light source unit was manufactured using the obtained light guide plate. Specifically, a reflection tape of product number RF188 manufactured by Tsujimoto Electric Machine Co., Ltd. was adhered to the side end surface other than the light incident end surface of each light guide plate, and Harrison Electric Co., Ltd. was attached to the short side light incident end portion. A cold cathode lamp with a tube diameter of 2.4 mmφ is installed, and the area around the lamp and the light incident portion of the light guide plate is a product number GR38 manufactured by Kimoto Corporation.
Covered with a W reflector. A reflection sheet of product number RF188 manufactured by Tsujimoto Electric Machine Co., Ltd. was arranged on the surface of the light guide plate opposite to the light exit surface to obtain an edge light type planar light source unit.

Using this unit, ΔYI, color temperature, color temperature unevenness, average luminance, luminance unevenness,
Table 1 summarizes the results of the evaluation of the moldability.

[0134] except for using ETCD / DCP = 15/85 ring-opening polymer hydrogenation product of Example 2 Reference Example 2, to obtain a light guide plate in the same manner as in Example 1. When the light transmittance of this light guide plate was measured,
The minimum light transmittance at 00 to 900 nm is 92.0
%, And the transparency was good. Using this light guide plate, an edge light type planar light source unit was prepared in the same manner as in Example 1, and the ΔYI, color temperature,
Table 1 summarizes the results of the evaluation of the color temperature unevenness, average brightness, brightness unevenness, and moldability.

Example 3 In the same manner as in Example 1 except that the hydrogenated ETCD / DCP = 15/85 ring-opening polymer of Reference Example 2 was used and the amount of the antioxidant was changed to 0.05 part by weight. A light guide plate was obtained.

When the light transmittance of this light guide plate was measured, the minimum light transmittance at 400 to 900 nm was 9%.
2.0%, and the transparency was good. Using this light guide plate, an edge light type planar light source unit was prepared in the same manner as in Example 1, and the ΔYI, color temperature, color temperature unevenness, average brightness, brightness unevenness, and moldability of the solution in which the light guide plate was dissolved were determined. Table 1 summarizes the evaluation results.

Comparative Example 1 A light guide plate was obtained in the same manner as in Example 2 except that 0.005 parts by weight of a phenolic antioxidant was added. When the light transmittance of this light guide plate was measured, the minimum light transmittance at 400 to 900 nm was 91.0%, and the transparency was good. Using this light guide plate, an edge light type planar light source unit was prepared in the same manner as in Example 1, and ΔYI, color temperature, color temperature unevenness, average luminance,
Table 1 summarizes the results of the evaluation of unevenness in brightness and moldability.

Comparative Example 2 A light guide plate was obtained in the same manner as in Example 2, except that 0.10 part by weight of a phenolic antioxidant was added. When the light transmittance of this light guide plate was measured, the minimum light transmittance at 400 to 900 nm was 92.0%, and the transparency was good. Using this light guide plate, an edge light type planar light source unit was prepared in the same manner as in Example 1, and the ΔYI, color temperature, color temperature unevenness, average brightness, brightness unevenness, and moldability of the solution in which the light guide plate was dissolved were determined. Table 1 summarizes the evaluation results.

Comparative Example 3 Comparative Example 2 was conducted except that the hydrogenated polymer produced in Reference Example 3 was used.
A light guide plate was obtained in the same manner as described above. When the light source absorptance of this light guide plate was measured, the minimum light transmittance at 400 to 900 nm was 91.0% and the transparency was good. Using this light guide plate, an edge light type planar light source unit was prepared in the same manner as in Example 1, and ΔY of a solution in which the light guide plate was dissolved was used.
Table 1 summarizes the results of evaluations of I, color temperature, color temperature unevenness, average brightness, brightness unevenness, and moldability.

[0140]

[Table 1]

[0141]

The edge light type light guide plate of the present invention is composed of a resin composition in which an alicyclic structure-containing polymer resin and an antioxidant are blended in a specific composition. The product is excellent in transparency, moldability and heat resistance, and is less likely to cause oxidative degradation and thermal degradation particularly during melt molding.

By setting the lower limit of the addition amount of the antioxidant to 100 parts by weight of the alicyclic structure-containing polymer resin to 0.01 part by weight, the heat resistance of the resin is not impaired during the melt molding of the light guide plate. Since the resin can be molded, the resin is not burned, and therefore, the risk of yellowing is reduced, and the color temperature at the light emitting surface near the light source and the light near the longest optical path length are reduced. The unevenness of the color temperature due to the difference from the color temperature on the emission surface is reduced, and the luminance is also improved. Further, by setting the upper limit to 0.08 parts by weight, it is possible to prevent the influence of the low-wavelength light absorption of the antioxidant, and as a result,
The color temperature unevenness is reduced, and the luminance is also improved. Therefore,
It is suitable for use in edge light type light guide plates that require a thinner and larger area.

When the above-mentioned resin composition is dissolved in a solvent soluble at a concentration of 15% by weight, it has a ΔYI of 1.0 or less with respect to the solvent at a measurement length of 10 mm. Therefore, even if the edge light type light guide plate made of this resin composition has an optical path length as long as 100 mm or more, it is possible to achieve better color temperature unevenness and higher brightness over the entire light exit surface of the light guide plate.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an outline of a light guide plate used in an edge light type planar light source device of various display devices and a planar light source device incorporating the light guide plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 100 ... Light guide plate 100a ... Light source side end surface 100b ... Light emission surface 100c ... Light reflection surface 100d ... Surface facing the light source side end surface 1001 ... V-shaped groove 200 ... Light source 300 ... Lamp reflector 400 ... Light diffusion sheet 500 ... Reflective sheet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tatsuo Miyazaki 1-2-1, Yako, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Zeon Corporation General Development Center (72) Inventor Yuichiro Konishi 2--6, Marunouchi, Chiyoda-ku, Tokyo No. 1 F-term in ZEON Corporation (reference) 2H038 AA55 BA06 2H091 FA23Z FA41Z FB04 FB12 FB13 LA11

Claims (4)

[Claims] 1. A light reflecting surface for reflecting incident light having at least one light incident surface for receiving light from at least one light source on a side surface, and for emitting reflected light. In an edge light type light guide plate having an emission surface, the light guide plate is prepared by blending 0.01 parts by weight to 0.08 parts by weight of an antioxidant with respect to 100 parts by weight of the alicyclic structure-containing polymer resin. An edge light type light guide plate, wherein a resin composition is melt-molded, and a length of the light guide plate in a longitudinal direction along a light incident direction from a light source is 100 mm or more. 2. When the light guide plate is dissolved in a soluble solvent at a concentration of 15% by weight, when the light guide plate is measured at a measurement length of 10 mm,
The edge light type light guide plate according to claim 1, wherein the solvent has a ΔYI of 1.0 or less. 3. A resin composition obtained by blending 0.01 to 0.08 parts by weight of an antioxidant with respect to 100 parts by weight of an alicyclic structure-containing polymer resin. Of manufacturing an edge light type light guide plate. 4. The method for producing an edge light type light guide plate according to claim 3, wherein the melt molding is injection molding.