WO2021132001A1 - Light diffusion plate and direct surface light source unit - Google Patents
Light diffusion plate and direct surface light source unit Download PDFInfo
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- WO2021132001A1 WO2021132001A1 PCT/JP2020/047109 JP2020047109W WO2021132001A1 WO 2021132001 A1 WO2021132001 A1 WO 2021132001A1 JP 2020047109 W JP2020047109 W JP 2020047109W WO 2021132001 A1 WO2021132001 A1 WO 2021132001A1
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- WIPO (PCT)
- Prior art keywords
- light diffusing
- tert
- antioxidant
- phosphorus
- butyl
- Prior art date
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Classifications
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/13—Phenols; Phenolates
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/49—Phosphorus-containing compounds
- C08K5/51—Phosphorus bound to oxygen
- C08K5/52—Phosphorus bound to oxygen only
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
- C08L25/02—Homopolymers or copolymers of hydrocarbons
- C08L25/04—Homopolymers or copolymers of styrene
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
- F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
Definitions
- the present invention relates to a light diffusing plate and a direct surface light source unit.
- the light diffuser is used for a direct type liquid crystal display device or the like.
- the direct type liquid crystal display device is a display device including a liquid crystal cell and a backlight device arranged directly under the liquid crystal cell.
- An LED is used as a light source in the backlight device, and a light diffuser is arranged on the front side thereof. Things are being used.
- the styrene-based resin composition may be used as a resin constituting the light diffusing plate (Patent Document 1).
- LEDs used as light sources have become more powerful in order to respond to higher brightness, and due to an increase in calorific value and the like, long-term durability of conventional light diffusing plates made of styrene-based resin compositions has become insufficient. There is. In some cases, the strength did not meet the requirements.
- the present invention has been made in view of such a problem, and is a light diffusing plate containing a styrene resin composition, and provides a light diffusing plate having excellent long-term durability and strength.
- a light diffusing plate containing a styrene resin composition, wherein the styrene resin composition is a styrene resin (A), an antioxidant (B), and a light diffusing agent (C).
- the antioxidant (B) is a phosphorus-based antioxidant (B-1), a phenol-based antioxidant (B-2), and a phosphorus-phenol-based antioxidant (B-3).
- a total of 0.001 of the phosphorus-based antioxidant (B-1) and the phosphorus-phenol-based antioxidant (B-3) is added to 100 parts by mass of the styrene-based resin.
- the light diffuser Provided is a light diffusing plate containing 0.1 to 10 parts by mass of C) and having a content of t-butyl catechol contained in the styrene resin composition of 0.1 to 10 ⁇ g / g.
- the styrene resin composition contains t-butylcatechol, a phosphorus-based antioxidant, a phenol-based antioxidant, a phosphorus-phenol-based antioxidant, and a light diffusing agent. They have found that they are excellent in long-term durability and strength when the amount is within a predetermined range, and have completed the present invention.
- the phosphorus-based antioxidant (B-1) is 2,2'-methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, tris (2,).
- the phenolic antioxidant (B-2) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-.
- the phosphorus-phenolic antioxidant (B-3) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-.
- a light diffusing plate which is tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphepine.
- the light diffusing agent (C) is at least one selected from acrylic polymer crosslinked particles, styrene polymer crosslinked particles, and siloxane polymer crosslinked particles.
- the styrene resin (A) has a weight average molecular weight (Mw) of 200,000 to 400,000, and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 1.0 to Mn.
- a light diffuser that is 3.0.
- the light diffusing plate for the LED light source of the light diffusing plate Preferably, a direct type surface light source unit having the above-mentioned light diffusing plate.
- the light diffusing plate according to the embodiment of the present invention is a light diffusing plate containing a styrene resin composition.
- the thickness of the light diffusing plate is not limited, but is, for example, 1 to 3 mm.
- the light diffusing plate may be laminated with an ultraviolet absorbing layer containing an ultraviolet absorber or a light stabilizer.
- An antistatic agent may be applied to the surface of the light diffusing plate according to the embodiment.
- the antistatic agent By applying the antistatic agent, after the light diffusing plate is attached to the backlight device, the adhesion of dust and the like due to static electricity is suppressed, so that the light diffusing plate can be used for a long period of time without a decrease in brightness.
- the light diffusing plate of the present invention may have fine uneven shapes such as embossing formed on both sides or directions thereof, or a semicircular or elliptical lens shape or a prism shape on both sides or one side. May be formed.
- the styrene-based resin composition contains a styrene-based resin (A), a based antioxidant (B), and a light diffusing agent (C).
- the content of t-butylcatechol contained in the styrene resin composition is 0.1 to 10 ⁇ g / g. Within such a range, long-term durability and strength are excellent. Specifically, the content of t-butylcatechol is 0.1,0.5,1,1.5,2,2.5,3,4,5,6,7,8,9,10 ⁇ g / It is g, and may be within the range between any two of the numerical values exemplified here.
- t-butylcatechol If the content of t-butylcatechol is less than 0.1 ⁇ g / g, the effect of suppressing oxidative deterioration during thermoforming is small, so that the strength of the light diffusing plate is reduced and the content of t-butylcatechol is 10 ⁇ g / g. If it exceeds, t-butylcatechol itself becomes a coloring component, and not only the long-term durability of the light diffusing plate is lowered, but also the strength is lowered.
- the styrene-based resin (A) is a resin obtained by polymerizing a styrene-based monomer as a main component, and specifically, a resin containing a styrene-based monomer in an amount of more than 50%.
- the styrene-based monomer is a single aromatic styrene-based monomer such as styrene, ⁇ -methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, ethylstyrene, and pt-butylstyrene.
- the styrene-based resin (A) may be a copolymer obtained by copolymerizing a monomer copolymerizable with the styrene-based monomer with the styrene-based monomer, and may be copolymerized with the styrene-based monomer.
- Possible monomers include, for example, an acrylic acid monomer such as acrylate and methacrylic acid, a vinyl cyanide monomer such as acrylonitrile and methacrylnitrile, and an acrylic type such as butyl acrylate, ethyl acrylate, methyl acrylate and methyl methacrylate.
- Examples thereof include monomers, ⁇ , ⁇ -ethylene unsaturated carboxylic acids such as maleic anhydride and fumaric acid, and imide-based monomers such as phenylmaleimide and cyclohexylmaleimide. These monomers may be used alone or in combination of two or more.
- the weight average molecular weight (Mw) of the styrene resin (A) is preferably 200,000 to 400,000, more preferably 200,000 to 290,000.
- the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the styrene resin (A) is preferably 1.0 to 3.0, more preferably 1.5 to. It is 2.5.
- the ratio (Mz / Mw) of the Z average molecular weight (Mz) and the weight average molecular weight (Mw) of the styrene resin (A) is preferably 1.0 to 2.0. Within such a range, both moldability and strength of the light diffusing plate can be achieved.
- the weight average molecular weight (Mw) When the weight average molecular weight (Mw) is 200,000 or more, the strength is good, and when it is 400,000 or less, the moldability is good. Further, when the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.0 or more, the moldability is good, and when it is 3.0 or less, the strength is good. When the ratio (Mz / Mw) of the Z average molecular weight (Mz) to the weight average molecular weight (Mw) is 1.0 or more, the moldability is good, and when it is 2.0 or less, the strength is good.
- the antioxidant (B) contains at least one of a phosphorus-based antioxidant (B-1), a phenol-based antioxidant (B-2), and a phosphorus-phenolic antioxidant (B-3).
- the styrene-based resin composition contains a total of 0.001 to 0.5 of a phosphorus-based antioxidant (B-1) and a phosphorus-phenol-based antioxidant (B-3) with respect to 100 parts by mass of the styrene-based resin. It is contained in parts by mass, preferably 0.05 to 0.3 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength.
- the total content of the phosphorus-based antioxidant (B-1) and the phosphorus-phenolic antioxidant (B-3) is 0.001,0 with respect to 100 parts by mass of the styrene-based resin. .005,0.01,0.02,0.03,0.04,0.05,0.1,0.15,0.2,0.25,0.3,0.35,0.4 , 0.45, 0.5 parts by mass, and may be within the range between any two of the numerical values exemplified here.
- a total of 0.001 to 0.5 parts by mass of a phenolic antioxidant (B-2) and a phosphorus / phenolic antioxidant (B-3) is contained, preferably 0.02 to 0.3 parts by mass. It is more preferably contained in an amount of 0.05 to 0.15 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength.
- the total content of the phenolic antioxidant (B-2) and the phosphorus / phenolic antioxidant (B-3) is 0.001,0 with respect to 100 parts by mass of the styrene resin. .005,0.01,0.02,0.03,0.04,0.05,0.1,0.15,0.2,0.25,0.3,0.35,0.4 , 0.45, 0.5 parts by mass, and may be within the range between any two of the numerical values exemplified here.
- the phosphorus-based antioxidant (B-1) is a (sub) phosphoric acid ester having no phenolic hydroxyl group in the basic skeleton, and is preferably a trivalent phosphorus compound, a phosphite ester.
- Phenyl antioxidants (B-1) include, for example, 2,2'-methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, tris (2,4-).
- Di-tert-butylphenyl) phosphite 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5, 5]
- Undecane tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite, bis (2,4-di-tert-butyl-6-methylphenyl) At least one selected from ethyl phosphite and the like.
- Phenolic antioxidant (B-2) is an antioxidant that has a phenolic hydroxyl group in its basic skeleton and is not a (sub) phosphate ester.
- Phenolic antioxidants (B-2) include, for example, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylenebis (oxyethylene) bis [3- (5-tert).
- Phosphite-phenolic antioxidants are (sub) phosphoric acid esters having a phenolic hydroxyl group in the basic skeleton, and preferably a trivalent phosphorus compound having a phenolic hydroxyl group in the basic skeleton. Phosphite esters. Phosphorus-phenolic antioxidant (B-3) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert- Butyldibenzo [d, f] [1,3,2] dioxaphosphepine and the like.
- the styrene resin composition contains 0.1 to 10 parts by mass, preferably 0.5 to 3 parts by mass, and more preferably 0.8 of the light diffusing agent (C) with respect to 100 parts by mass of the styrene resin. Includes up to 1.5 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength.
- the content of the light diffusing agent (C) is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, with respect to 100 parts by mass of the styrene resin. 0.7, 0.8, 0.9, 1.0, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10 parts by mass, and any of the numerical values exemplified here. It may be within the range between the two.
- the light diffusing agent (C) can be used as long as it is particles having a refractive index different from that of the styrene resin composition and has an effect of diffusing incident light.
- styrene polymer crosslinked particles can be used.
- Use organic particles such as acrylic polymer crosslinked particles and siloxane polymer crosslinked particles, and inorganic particles such as glass beads, silica particles, aluminum hydroxide particles, calcium carbonate particles, barium sulfate particles, titanium oxide particles, and talc.
- glass beads, silica particles, aluminum hydroxide particles, calcium carbonate particles, barium sulfate particles, titanium oxide particles, and talc can be done.
- at least one selected from acrylic polymer crosslinked particles, styrene polymer crosslinked particles, and siloxane polymer crosslinked particles is preferable.
- the average particle size of the light diffusing agent (C) is preferably 1 to 20 ⁇ m. If the average particle size of the light diffusing agent (C) is less than 1 ⁇ m, the hue may deteriorate, and if it exceeds 20 ⁇ m, the light diffusing property may not be sufficiently imparted.
- the type of additive is not particularly limited as long as it is generally used for plastics, but it is a flame retardant, a lubricant, a processing aid, an antiblocking agent, an antistatic agent, an antifogging agent, a light resistance improver, and a softening agent.
- the styrene-based resin composition of the present invention can be manufactured by adding an antioxidant (B) and a light diffusing agent (C) to a styrene resin (A). Is.
- the antioxidant (B) and the light diffusing agent (C) may be added at the time of polymerization of the styrene resin (A), or after the styrene resin (A) is polymerized, the antioxidant (B) and the antioxidant (B) may be added.
- the light diffusing agent (C) may be dry-blended and melt-kneaded with an extruder to produce the product.
- a pellet-shaped masterbatch obtained by melting and kneading the antioxidant (B) and the light diffusing agent (C) together with a small amount of styrene resin in advance was prepared, and the styrene resin (A) and the masterbatch were prepared. And may be dry-blended and then melt-kneaded for adjustment.
- Examples of the polymerization method of the styrene resin include known styrene polymerization methods such as a massive polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. From the viewpoint of quality and productivity, the bulk polymerization method and the solution polymerization method are preferable, and continuous polymerization is preferable.
- the solvent for example, alkylbenzenes such as benzene, toluene, ethylbenzene and xylene, ketones such as acetone and methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and cyclohexane can be used.
- a polymerization initiator When the styrene resin (A) is polymerized, a polymerization initiator, a chain transfer agent, a cross-linking agent and other polymerization aids, and other polymerization aids can be used, if necessary.
- a radical polymerization initiator is preferable, and for example, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (t-butylperoxy) butane, 2,2-di (t-butylperoxy) butane, which are known and commonly used, are preferable.
- Peroxyketals such as di (4,5-di-t-butylperoxycyclohexyl) propane, 1,1-di (t-amylperoxy) cyclohexane, cumenehydroperoxide, t-butylhydroperoxide and the like.
- alkyl peroxides such as t-butylperoxyacetate, t-amylperoxyisononanoate, t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, di-t -Dialkyl peroxides such as hexyl peroxide, peroxyesters such as t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxyisopropyl carbonate, polyether Peroxycarbonates such as tetrakis (t-butylperoxycarbonate), N, N'-azobis (cyclohexane-1-carbonitrile), N, N'-azobis (2-methylbutyronitrile), N, N' -Azobis (2,4-dimethylvaleronitrile), N, N'-azobis [2- (hydroxymethyl)
- the styrene resin can be produced by a method including a polymerization step, a volatilization step, and a granulation step.
- a known complete mixing tank type stirring tank, a tower reactor, or the like is used, and the polymerization reaction is controlled by adjusting the polymerization temperature or the like so as to obtain the target molecular weight, molecular weight distribution, and reaction conversion rate.
- the polymerization solution containing the polymer that has left the polymerization step is transferred to the devolatile step, and the unreacted monomer and the polymerization solvent are removed.
- the devolatilization process consists of a vacuum devolatilization tank with a heater and a devolatilization extruder with a vent.
- the molten polymer that has left the devolatile step is transferred to the granulation step.
- the molten resin is extruded into a strand shape from a porous die and processed into a pellet shape by a cold cut method, an aerial hot cut method, or an underwater hot cut method.
- the content of t-butylcatechol in the styrene resin composition can be adjusted at the start of polymerization of the styrene resin (A) and in the subsequent devolatile step. Further, the styrene resin (A) may be adjusted by adding the styrene resin (A), the antioxidant (B), the light diffusing agent (C) and the like before and after the addition.
- the light diffusing plate can be manufactured by molding a styrene resin composition by various methods such as extrusion molding and injection molding, but is preferably manufactured by extrusion molding.
- extrusion molding is a method in which a styrene resin composition is melt-kneaded using a single-screw extruder or a twin-screw extruder, continuously extruded from a T die, and then cooled and solidified by a cooling roll unit. Be done.
- an arbitrary uneven shape can be formed by providing a transfer mold on the surface of the cooling roll and changing the shape of the transfer mold.
- a method such as a coextrusion method, a sticking method, a heat bonding method, a solvent bonding method, a casting method, or a surface coating method can be adopted.
- the light diffusing plate according to the embodiment of the present invention can be used as a light diffusing plate for an LED light source.
- the direct type surface light source unit according to the embodiment of the present invention is a direct type surface light source unit having the above-mentioned light diffusing plate.
- ⁇ Vicat softening temperature> According to JIS K 7206, the measurement was performed at a heating rate of 50 ° C./hr and a test load of 50 N.
- TBC t-butylcatechol
- GC device Agilent 7890A
- Column Agilent DB-5ms (0.25mm id x 30m) Liquid phase film thickness 0.25 ⁇ m
- Injection port 300 ° C, 1.5 mL / min, (split ratio 1: 5)
- MS device Agilent 5975C
- Interface temperature 320 ° C
- MS detection conditions SIM measurement TBC (quantitative m / z 295, confirmation m / z 310)
- Total light transmittance, YI> Using a turbidity meter NDH5000 manufactured by Nippon Denshoku Kogyo Co., Ltd., the total light transmittance in the thickness direction of the light diffusing plate was measured in accordance with JIS-K7105.
- the YI of the light diffusing plate was measured by the reflection method using a colorimetric chromaticity meter NDJ4000 manufactured by Nippon Denshoku Kogyo Co., Ltd. in accordance with JIS-K7105.
- the central part of the light diffusing plate is hollowed out in a square shape of 115 mm ⁇ 115 mm, and the hollowed out portion is used.
- an evaluation test piece obtained by cutting out the light diffusing plate obtained in the comparative example to 115 mm ⁇ 115 mm or an evaluation test piece of 115 mm ⁇ 115 mm after the durability test is attached, and this is attached to the frame of the liquid crystal television after taking out. I put it on.
- the light diffusing plate was cut into a square shape of 200 mm ⁇ 200 mm and used as an evaluation test piece. Using a ball weighing 16.6 g, a 50% fracture height was measured according to JIS K-7211 and evaluated according to the following criteria. ⁇ : 50% destruction height exceeds 40 cm ⁇ : 50% destruction height is 20 to 40 cm X: 50% destruction height is less than 20 cm
- the polymerization initiator was added to the raw material solution at the inlet of the first reactor so as to have the addition concentration (concentration based on the mass with respect to the raw material styrene) shown in Table 1, and uniformly mixed.
- the polymerization initiators listed in Table 1 are as follows.
- Polymerization Initiator-1 2,2-di (4,5-t-butylperoxycyclohexyl) propane (Pertetra A manufactured by NOF CORPORATION was used)
- Polymerization Initiator-2 1,1-di (t-Butyl Peroxy) Cyclohexane (Perhexa C manufactured by NOF CORPORATION was used)
- a temperature gradient was applied along the flow direction, and the temperature was adjusted to the temperature shown in Table 1 at the intermediate portion and the outlet portion.
- a solution containing the polymer continuously taken out from the third reactor was introduced into a vacuum devolatilization tank with a preheater composed of two stages in series, and the preheater was adjusted to the resin temperature shown in Table 1.
- the strands are extruded into strands from a porous die, and the strands are cooled and cut by a cold cut method. It was pelletized.
- PS-2 to PS-5 were also synthesized in the same manner as PS-1 except that the conditions were changed according to Table 1.
- Example 1 0.2 parts by mass of phosphorus-based antioxidant (HP-10) and phosphorus-phenol with respect to 100 parts by mass of styrene resin (PS-1) containing t-butylcatechol (TBC) in the amount shown in Table 1.
- PS-1 styrene resin
- TBC t-butylcatechol
- GP system antioxidant
- MBX-8 1.0 part by mass of the light diffusing agent
- a light diffusing plate having a width of 800 mm and a thickness of 2.0 mm was obtained by discharging with a 0 mm T-die at a T-die temperature of 245 to 250 ° C., cooling and solidifying with three vertical cooling rolls, and trimming the end face.
- the initial optical characteristics of the light diffusing plate were measured based on each measuring method, and the initial intensity was also measured.
- the above durability test was performed, and the subsequent optical characteristics were measured based on each measuring method.
- Examples 2 to 15 and Comparative Examples 1 to 7 were also measured by obtaining a resin composition / light diffusing plate in the same manner as in Example 1 except that the conditions were changed according to the conditions shown in Tables 2 and 3. .. The results are shown in Tables 2 and 3.
- HP-10 2,2'-Methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) Phosphorus (manufactured by ADEKA; HP-10) 168: Tris (2,4-di-tert-butylphenyl) phosphite (manufactured by BASF Japan; Irgafos168) PEP-36: 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] Undecane (ADEKA) Made; PEP-36) P-EPQ: Tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite (manufactured by BASF Japan; IrgafosP-
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Abstract
The present invention provides a light diffusion plate which contains a styrene resin composition, while having excellent long-term durability and strength. The present invention provides a light diffusion plate which contains a styrene resin composition, wherein: the styrene resin composition contains a styrene resin (A), an antioxidant (B) and a light diffusing agent (C); the antioxidant (B) contains at least one of a phosphorus antioxidant (B-1), a phenolic antioxidant (B-2) and a phosphorus/phenolic antioxidant (B-3); relative to 100 parts by mass of the styrene resin, a total of from 0.001 to 0.5 part by mass of the phosphorus antioxidant (B-1) and the phosphorus/phenolic antioxidant (B-3), a total of from 0.001 to 0.5 part by mass of the phenolic antioxidant (B-2) and the phosphorus/phenolic antioxidant (B-3), and from 0.1 to 10 parts by mass of the light diffusing agent (C) are contained; and the content of t-butyl catechol contained in the styrene resin composition is from 0.1 to 10 μg/g.
Description
本発明は、光拡散板及び直下型面光源ユニットに関する。
The present invention relates to a light diffusing plate and a direct surface light source unit.
光拡散板は、直下型液晶ディスプレイ装置等に用いられる。直下型液晶ディスプレイ装置は、液晶セルとその直下に配置されたバックライト装置とを備えたディスプレイ装置であり、バックライト装置には光源としてＬＥＤが用いられ、その前面側に光拡散板を配置したものが使用されている。そして、スチレン系樹脂組成物が光拡散板を構成する樹脂として用いられることがある（特許文献１）。
The light diffuser is used for a direct type liquid crystal display device or the like. The direct type liquid crystal display device is a display device including a liquid crystal cell and a backlight device arranged directly under the liquid crystal cell. An LED is used as a light source in the backlight device, and a light diffuser is arranged on the front side thereof. Things are being used. Then, the styrene-based resin composition may be used as a resin constituting the light diffusing plate (Patent Document 1).
しかし、高輝度化に応えるため光源として用いられるＬＥＤがハイパワー化してきており、発熱量の増大等により、従来のスチレン系樹脂組成物による光拡散板では長期耐久性が不十分となってきている。また、強度が要求を満たさない場合もあった。
However, LEDs used as light sources have become more powerful in order to respond to higher brightness, and due to an increase in calorific value and the like, long-term durability of conventional light diffusing plates made of styrene-based resin compositions has become insufficient. There is. In some cases, the strength did not meet the requirements.
本発明はこのような問題に鑑みてなされたものであり、スチレン系樹脂組成物を含む光拡散板であって、優れた長期耐久性及び強度を有する光拡散板を提供するものである。
The present invention has been made in view of such a problem, and is a light diffusing plate containing a styrene resin composition, and provides a light diffusing plate having excellent long-term durability and strength.
本発明によれば、スチレン系樹脂組成物を含む光拡散板であって、前記スチレン系樹脂組成物が、スチレン系樹脂（Ａ）と、酸化防止剤（Ｂ）と、光拡散剤（Ｃ）と、を含有し、前記酸化防止剤（Ｂ）は、リン系酸化防止剤（Ｂ－１）、フェノール系酸化防止剤（Ｂ－２）、及びリン・フェノール系酸化防止剤（Ｂ－３）のうち少なくとも１種を含み、前記スチレン系樹脂１００質量部に対して、前記リン系酸化防止剤（Ｂ－１）と前記リン・フェノール系酸化防止剤（Ｂ－３）を合計で０．００１～０．５質量部、前記フェノール系酸化防止剤（Ｂ－２）と前記リン・フェノール系酸化防止剤（Ｂ－３）を合計で０．００１～０．５質量部、前記光拡散剤（Ｃ）を０．１～１０質量部、含有し、前記スチレン系樹脂組成物に含まれるｔ－ブチルカテコールの含有量が０．１～１０μｇ／ｇである、光拡散板が提供される
According to the present invention, a light diffusing plate containing a styrene resin composition, wherein the styrene resin composition is a styrene resin (A), an antioxidant (B), and a light diffusing agent (C). The antioxidant (B) is a phosphorus-based antioxidant (B-1), a phenol-based antioxidant (B-2), and a phosphorus-phenol-based antioxidant (B-3). A total of 0.001 of the phosphorus-based antioxidant (B-1) and the phosphorus-phenol-based antioxidant (B-3) is added to 100 parts by mass of the styrene-based resin. ~ 0.5 parts by mass, 0.001 to 0.5 parts by mass of the phenolic antioxidant (B-2) and the phosphorus / phenolic antioxidant (B-3) in total, the light diffuser ( Provided is a light diffusing plate containing 0.1 to 10 parts by mass of C) and having a content of t-butyl catechol contained in the styrene resin composition of 0.1 to 10 μg / g.
本発明者らは、鋭意検討を行ったところ、スチレン系樹脂組成物におけるｔ－ブチルカテコール、リン系酸化防止剤、フェノール系酸化防止剤、リン・フェノール系酸化防止剤、及び光拡散剤の含有量が所定の範囲内である場合に長期耐久性及び強度に優れることを見出し、本発明の完成に至った。
As a result of diligent studies, the present inventors have found that the styrene resin composition contains t-butylcatechol, a phosphorus-based antioxidant, a phenol-based antioxidant, a phosphorus-phenol-based antioxidant, and a light diffusing agent. They have found that they are excellent in long-term durability and strength when the amount is within a predetermined range, and have completed the present invention.
以下、本発明の種々の実施形態を例示する。以下に示す実施形態は互いに組み合わせ可能である。
好ましくは、前記リン系酸化防止剤（Ｂ－１）が、２，２'－メチレンビス（４，６－ジ－ｔｅｒｔ－ブチル－１－フェニルオキシ）（２－エチルヘキシルオキシ）ホスホラス、トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）フォスファイト、３，９－ビス（２，６－ジ―ｔｅｒｔ－ブチル―４－メチルフェノキシ）－２，４，８，１０－テトラオキサ―３，９－ジホスファスピロ〔５，５〕ウンデカン、テトラキス（２，４－ジ―ｔｅｒｔ－ブチルフェニル）〔１，１ビフェニル〕―４，４'ジイルビスホスホナイト、ビス（２，４－ジ―ｔｅｒｔ－ブチル―６－メチルフェニル）エチル亜リン酸エステルから選ばれる少なくとも１種である、光拡散板。
好ましくは、前記フェノール系酸化防止剤（Ｂ－２）が、６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピン、オクタデシル－３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート、エチレンビス（オキシエチレン）ビス〔３－（５－ｔｅｒｔ－ブチル－４－ヒドロキシ－ｍ－トリル）プロピオネート〕、ペンタエリスリトールテトラキス［３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート］、３，９－ビス［２－〔３－（３－ｔｅｒｔ－ブチル―４－ヒドロキシ―５－メチルフェニル）プロピオニルオキシ〕－１，１－ジメチルエチル］－２，４，８，１０－テトラオキサスピロ［５，５］ウンデカンから選ばれる少なくとも１種である、光拡散板。
好ましくは、前記リン・フェノール系酸化防止剤（Ｂ－３）が、６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピンである、光拡散板。
好ましくは、前記光拡散剤（Ｃ）が、アクリル系重合体架橋粒子、スチレン系重合体架橋粒子、シロキサン系重合体架橋粒子から選ばれる少なくとも１種である、光拡散板。
好ましくは、前記スチレン系樹脂（Ａ）の重量平均分子量（Ｍｗ）が２０万～４０万で、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が１．０～３．０である、光拡散板。
好ましくは、上記光拡散板のＬＥＤ光源用光拡散板。
好ましくは、上記光拡散板を有する、直下型面光源ユニット。 Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.
Preferably, the phosphorus-based antioxidant (B-1) is 2,2'-methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, tris (2,). 4-Di-tert-butylphenyl) phosphite, 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [ 5,5] Undecane, tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite, bis (2,4-di-tert-butyl-6-methyl) A light diffusing plate, which is at least one selected from phenyl) ethyl sulfite.
Preferably, the phenolic antioxidant (B-2) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-. tert-Butyldibenzo [d, f] [1,3,2] dioxaphosphepine, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, ethylenebis (oxyethylene) Bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,9 -Bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5, 5] A light diffuser, which is at least one selected from Undecan.
Preferably, the phosphorus-phenolic antioxidant (B-3) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-. A light diffusing plate which is tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphepine.
Preferably, the light diffusing agent (C) is at least one selected from acrylic polymer crosslinked particles, styrene polymer crosslinked particles, and siloxane polymer crosslinked particles.
Preferably, the styrene resin (A) has a weight average molecular weight (Mw) of 200,000 to 400,000, and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 1.0 to Mn. A light diffuser that is 3.0.
Preferably, the light diffusing plate for the LED light source of the light diffusing plate.
Preferably, a direct type surface light source unit having the above-mentioned light diffusing plate.
好ましくは、前記リン系酸化防止剤（Ｂ－１）が、２，２'－メチレンビス（４，６－ジ－ｔｅｒｔ－ブチル－１－フェニルオキシ）（２－エチルヘキシルオキシ）ホスホラス、トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）フォスファイト、３，９－ビス（２，６－ジ―ｔｅｒｔ－ブチル―４－メチルフェノキシ）－２，４，８，１０－テトラオキサ―３，９－ジホスファスピロ〔５，５〕ウンデカン、テトラキス（２，４－ジ―ｔｅｒｔ－ブチルフェニル）〔１，１ビフェニル〕―４，４'ジイルビスホスホナイト、ビス（２，４－ジ―ｔｅｒｔ－ブチル―６－メチルフェニル）エチル亜リン酸エステルから選ばれる少なくとも１種である、光拡散板。
好ましくは、前記フェノール系酸化防止剤（Ｂ－２）が、６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピン、オクタデシル－３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート、エチレンビス（オキシエチレン）ビス〔３－（５－ｔｅｒｔ－ブチル－４－ヒドロキシ－ｍ－トリル）プロピオネート〕、ペンタエリスリトールテトラキス［３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート］、３，９－ビス［２－〔３－（３－ｔｅｒｔ－ブチル―４－ヒドロキシ―５－メチルフェニル）プロピオニルオキシ〕－１，１－ジメチルエチル］－２，４，８，１０－テトラオキサスピロ［５，５］ウンデカンから選ばれる少なくとも１種である、光拡散板。
好ましくは、前記リン・フェノール系酸化防止剤（Ｂ－３）が、６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピンである、光拡散板。
好ましくは、前記光拡散剤（Ｃ）が、アクリル系重合体架橋粒子、スチレン系重合体架橋粒子、シロキサン系重合体架橋粒子から選ばれる少なくとも１種である、光拡散板。
好ましくは、前記スチレン系樹脂（Ａ）の重量平均分子量（Ｍｗ）が２０万～４０万で、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が１．０～３．０である、光拡散板。
好ましくは、上記光拡散板のＬＥＤ光源用光拡散板。
好ましくは、上記光拡散板を有する、直下型面光源ユニット。 Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.
Preferably, the phosphorus-based antioxidant (B-1) is 2,2'-methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, tris (2,). 4-Di-tert-butylphenyl) phosphite, 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [ 5,5] Undecane, tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite, bis (2,4-di-tert-butyl-6-methyl) A light diffusing plate, which is at least one selected from phenyl) ethyl sulfite.
Preferably, the phenolic antioxidant (B-2) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-. tert-Butyldibenzo [d, f] [1,3,2] dioxaphosphepine, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, ethylenebis (oxyethylene) Bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate], pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,9 -Bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5, 5] A light diffuser, which is at least one selected from Undecan.
Preferably, the phosphorus-phenolic antioxidant (B-3) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-. A light diffusing plate which is tetra-tert-butyldibenzo [d, f] [1,3,2] dioxaphosphepine.
Preferably, the light diffusing agent (C) is at least one selected from acrylic polymer crosslinked particles, styrene polymer crosslinked particles, and siloxane polymer crosslinked particles.
Preferably, the styrene resin (A) has a weight average molecular weight (Mw) of 200,000 to 400,000, and a ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 1.0 to Mn. A light diffuser that is 3.0.
Preferably, the light diffusing plate for the LED light source of the light diffusing plate.
Preferably, a direct type surface light source unit having the above-mentioned light diffusing plate.
以下、本発明の実施形態について説明する。以下に示す実施形態中で示した各種特徴事項は、互いに組み合わせ可能である。また、各特徴事項について独立して発明が成立する。
Hereinafter, embodiments of the present invention will be described. The various features shown in the embodiments shown below can be combined with each other. In addition, the invention is independently established for each feature.
１．光拡散板
本発明の一実施形態にかかる光拡散板は、スチレン系樹脂組成物を含む光拡散板である。光拡散板の厚みは、制限されないが、例えば１～３ｍｍである。また、光拡散板は、紫外線吸収剤や光安定剤を配合した紫外線吸収層が積層されていてもよい。 1. 1. Light Diffusing Plate The light diffusing plate according to the embodiment of the present invention is a light diffusing plate containing a styrene resin composition. The thickness of the light diffusing plate is not limited, but is, for example, 1 to 3 mm. Further, the light diffusing plate may be laminated with an ultraviolet absorbing layer containing an ultraviolet absorber or a light stabilizer.
本発明の一実施形態にかかる光拡散板は、スチレン系樹脂組成物を含む光拡散板である。光拡散板の厚みは、制限されないが、例えば１～３ｍｍである。また、光拡散板は、紫外線吸収剤や光安定剤を配合した紫外線吸収層が積層されていてもよい。 1. 1. Light Diffusing Plate The light diffusing plate according to the embodiment of the present invention is a light diffusing plate containing a styrene resin composition. The thickness of the light diffusing plate is not limited, but is, for example, 1 to 3 mm. Further, the light diffusing plate may be laminated with an ultraviolet absorbing layer containing an ultraviolet absorber or a light stabilizer.
一実施形態に係る光拡散板には、その表面に帯電防止剤が塗布されていてもよい。帯電防止剤が塗布されていることによって、光拡散板をバックライト装置に取り付け後、静電気による埃等の付着が抑えられるため、長期間にわたって輝度の低下なく使用することができる。また、本発明の光拡散板には、その両面もしくは方面にエンボス加工等の細かな凹凸形状が形成されていてもよいし、両面もしくは片面に半円形状や楕円形状のレンズ形状、もしくはプリズム形状が形成されていてもよい。
An antistatic agent may be applied to the surface of the light diffusing plate according to the embodiment. By applying the antistatic agent, after the light diffusing plate is attached to the backlight device, the adhesion of dust and the like due to static electricity is suppressed, so that the light diffusing plate can be used for a long period of time without a decrease in brightness. Further, the light diffusing plate of the present invention may have fine uneven shapes such as embossing formed on both sides or directions thereof, or a semicircular or elliptical lens shape or a prism shape on both sides or one side. May be formed.
＜スチレン系樹脂組成物＞
スチレン系樹脂組成物は、スチレン系樹脂（Ａ）と、系酸化防止剤（Ｂ）と、光拡散剤（Ｃ）と、を含有する。また、スチレン系樹脂組成物に含まれるｔ－ブチルカテコールの含有量は、０．１～１０μｇ／ｇである。このような範囲とすることで、長期耐久性及び強度に優れる。ｔ－ブチルカテコールの含有量は、具体的には、０．１，０．５，１，１．５，２，２．５，３，４，５，６，７，８，９，１０μｇ／ｇであり、ここで例示した数値の何れか２つの間の範囲内であってもよい。ｔ－ブチルカテコールの含有量が０．１μｇ／ｇ未満では、熱成形加工時における酸化劣化の抑制効果が小さいため、光拡散板の強度が低下し、ｔ－ブチルカテコールの含有量が１０μｇ／ｇを超えると、ｔ－ブチルカテコール自体が着色成分となり、光拡散板の長期耐久性が低下するだけでなく、強度も低下する。 <Styrene-based resin composition>
The styrene-based resin composition contains a styrene-based resin (A), a based antioxidant (B), and a light diffusing agent (C). The content of t-butylcatechol contained in the styrene resin composition is 0.1 to 10 μg / g. Within such a range, long-term durability and strength are excellent. Specifically, the content of t-butylcatechol is 0.1,0.5,1,1.5,2,2.5,3,4,5,6,7,8,9,10 μg / It is g, and may be within the range between any two of the numerical values exemplified here. If the content of t-butylcatechol is less than 0.1 μg / g, the effect of suppressing oxidative deterioration during thermoforming is small, so that the strength of the light diffusing plate is reduced and the content of t-butylcatechol is 10 μg / g. If it exceeds, t-butylcatechol itself becomes a coloring component, and not only the long-term durability of the light diffusing plate is lowered, but also the strength is lowered.
スチレン系樹脂組成物は、スチレン系樹脂（Ａ）と、系酸化防止剤（Ｂ）と、光拡散剤（Ｃ）と、を含有する。また、スチレン系樹脂組成物に含まれるｔ－ブチルカテコールの含有量は、０．１～１０μｇ／ｇである。このような範囲とすることで、長期耐久性及び強度に優れる。ｔ－ブチルカテコールの含有量は、具体的には、０．１，０．５，１，１．５，２，２．５，３，４，５，６，７，８，９，１０μｇ／ｇであり、ここで例示した数値の何れか２つの間の範囲内であってもよい。ｔ－ブチルカテコールの含有量が０．１μｇ／ｇ未満では、熱成形加工時における酸化劣化の抑制効果が小さいため、光拡散板の強度が低下し、ｔ－ブチルカテコールの含有量が１０μｇ／ｇを超えると、ｔ－ブチルカテコール自体が着色成分となり、光拡散板の長期耐久性が低下するだけでなく、強度も低下する。 <Styrene-based resin composition>
The styrene-based resin composition contains a styrene-based resin (A), a based antioxidant (B), and a light diffusing agent (C). The content of t-butylcatechol contained in the styrene resin composition is 0.1 to 10 μg / g. Within such a range, long-term durability and strength are excellent. Specifically, the content of t-butylcatechol is 0.1,0.5,1,1.5,2,2.5,3,4,5,6,7,8,9,10 μg / It is g, and may be within the range between any two of the numerical values exemplified here. If the content of t-butylcatechol is less than 0.1 μg / g, the effect of suppressing oxidative deterioration during thermoforming is small, so that the strength of the light diffusing plate is reduced and the content of t-butylcatechol is 10 μg / g. If it exceeds, t-butylcatechol itself becomes a coloring component, and not only the long-term durability of the light diffusing plate is lowered, but also the strength is lowered.
＜スチレン系樹脂（Ａ）＞
スチレン系樹脂（Ａ）は、スチレン系単量体を主成分として重合して得られる樹脂であって、具体的には、スチレン系単量体を５０％を超えて含む樹脂である。スチレン系単量体とは、芳香族スチレン系モノマーである、スチレン、α－メチルスチレン、ｏ－メチルスチレン、ｐ－メチルスチレン、ｍ－メチルスチレン、エチルスチレン、ｐ－ｔ－ブチルスチレン等の単独または２種以上の混合物であり、好ましくはスチレンである。また、スチレン系樹脂（Ａ）は、スチレン系単量体と共重合可能なモノマーを、スチレン系単量体と共重合して得られるコポリマーであってもよく、スチレン系単量体と共重合可能なモノマーとしては、例えば、アクリル酸、メタクリル酸等のアクリル酸モノマー、アクリロニトリル、メタクリロニトリル等のシアン化ビニルモノマー、アクリル酸ブチル、アクリル酸エチル、アクリル酸メチル、メタクリル酸メチル等のアクリル系モノマーや無水マレイン酸、フマル酸等のα，β－エチレン不飽和カルボン酸類、フェニルマレイミド、シクロヘキシルマレイミド等のイミド系モノマー類が挙げられる。これらのモノマーは、１種を単独または２種以上を組み合わせて使用することができる。 <Styrene resin (A)>
The styrene-based resin (A) is a resin obtained by polymerizing a styrene-based monomer as a main component, and specifically, a resin containing a styrene-based monomer in an amount of more than 50%. The styrene-based monomer is a single aromatic styrene-based monomer such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, ethylstyrene, and pt-butylstyrene. Alternatively, it is a mixture of two or more kinds, preferably styrene. Further, the styrene-based resin (A) may be a copolymer obtained by copolymerizing a monomer copolymerizable with the styrene-based monomer with the styrene-based monomer, and may be copolymerized with the styrene-based monomer. Possible monomers include, for example, an acrylic acid monomer such as acrylate and methacrylic acid, a vinyl cyanide monomer such as acrylonitrile and methacrylnitrile, and an acrylic type such as butyl acrylate, ethyl acrylate, methyl acrylate and methyl methacrylate. Examples thereof include monomers, α, β-ethylene unsaturated carboxylic acids such as maleic anhydride and fumaric acid, and imide-based monomers such as phenylmaleimide and cyclohexylmaleimide. These monomers may be used alone or in combination of two or more.
スチレン系樹脂（Ａ）は、スチレン系単量体を主成分として重合して得られる樹脂であって、具体的には、スチレン系単量体を５０％を超えて含む樹脂である。スチレン系単量体とは、芳香族スチレン系モノマーである、スチレン、α－メチルスチレン、ｏ－メチルスチレン、ｐ－メチルスチレン、ｍ－メチルスチレン、エチルスチレン、ｐ－ｔ－ブチルスチレン等の単独または２種以上の混合物であり、好ましくはスチレンである。また、スチレン系樹脂（Ａ）は、スチレン系単量体と共重合可能なモノマーを、スチレン系単量体と共重合して得られるコポリマーであってもよく、スチレン系単量体と共重合可能なモノマーとしては、例えば、アクリル酸、メタクリル酸等のアクリル酸モノマー、アクリロニトリル、メタクリロニトリル等のシアン化ビニルモノマー、アクリル酸ブチル、アクリル酸エチル、アクリル酸メチル、メタクリル酸メチル等のアクリル系モノマーや無水マレイン酸、フマル酸等のα，β－エチレン不飽和カルボン酸類、フェニルマレイミド、シクロヘキシルマレイミド等のイミド系モノマー類が挙げられる。これらのモノマーは、１種を単独または２種以上を組み合わせて使用することができる。 <Styrene resin (A)>
The styrene-based resin (A) is a resin obtained by polymerizing a styrene-based monomer as a main component, and specifically, a resin containing a styrene-based monomer in an amount of more than 50%. The styrene-based monomer is a single aromatic styrene-based monomer such as styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, ethylstyrene, and pt-butylstyrene. Alternatively, it is a mixture of two or more kinds, preferably styrene. Further, the styrene-based resin (A) may be a copolymer obtained by copolymerizing a monomer copolymerizable with the styrene-based monomer with the styrene-based monomer, and may be copolymerized with the styrene-based monomer. Possible monomers include, for example, an acrylic acid monomer such as acrylate and methacrylic acid, a vinyl cyanide monomer such as acrylonitrile and methacrylnitrile, and an acrylic type such as butyl acrylate, ethyl acrylate, methyl acrylate and methyl methacrylate. Examples thereof include monomers, α, β-ethylene unsaturated carboxylic acids such as maleic anhydride and fumaric acid, and imide-based monomers such as phenylmaleimide and cyclohexylmaleimide. These monomers may be used alone or in combination of two or more.
スチレン系樹脂（Ａ）の重量平均分子量（Ｍｗ）は、好ましくは２０万～４０万であり、より好ましくは２０～２９万である。また、スチレン系樹脂（Ａ）の重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）は、好ましくは１．０～３．０であり、より好ましくは１．５～２．５である。また、スチレン系樹脂（Ａ）のＺ平均分子量（Ｍｚ）と重量平均分子量（Ｍｗ）の比（Ｍｚ／Ｍｗ）は、好ましくは１．０～２．０である。このような範囲とすることで、光拡散板の成形性と強度を両立することができる。重量平均分子量（Ｍｗ）が２０万以上では、強度が良好となり、４０万以下だと、成形性が良好である。また、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比が１．０以上だと、成形性が良好であり、３．０以下だと、強度が良好である。Ｚ平均分子量（Ｍｚ）と重量平均分子量（Ｍｗ）の比（Ｍｚ／Ｍｗ）１．０以上だと、成形性が良好であり、２．０以下だと、強度が良好である。
The weight average molecular weight (Mw) of the styrene resin (A) is preferably 200,000 to 400,000, more preferably 200,000 to 290,000. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the styrene resin (A) is preferably 1.0 to 3.0, more preferably 1.5 to. It is 2.5. The ratio (Mz / Mw) of the Z average molecular weight (Mz) and the weight average molecular weight (Mw) of the styrene resin (A) is preferably 1.0 to 2.0. Within such a range, both moldability and strength of the light diffusing plate can be achieved. When the weight average molecular weight (Mw) is 200,000 or more, the strength is good, and when it is 400,000 or less, the moldability is good. Further, when the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.0 or more, the moldability is good, and when it is 3.0 or less, the strength is good. When the ratio (Mz / Mw) of the Z average molecular weight (Mz) to the weight average molecular weight (Mw) is 1.0 or more, the moldability is good, and when it is 2.0 or less, the strength is good.
＜酸化防止剤（Ｂ）＞
酸化防止剤（Ｂ）は、リン系酸化防止剤（Ｂ－１）、フェノール系酸化防止剤（Ｂ－２）、及びリン・フェノール系酸化防止剤（Ｂ－３）の少なくとも１種を含む。 <Antioxidant (B)>
The antioxidant (B) contains at least one of a phosphorus-based antioxidant (B-1), a phenol-based antioxidant (B-2), and a phosphorus-phenolic antioxidant (B-3).
酸化防止剤（Ｂ）は、リン系酸化防止剤（Ｂ－１）、フェノール系酸化防止剤（Ｂ－２）、及びリン・フェノール系酸化防止剤（Ｂ－３）の少なくとも１種を含む。 <Antioxidant (B)>
The antioxidant (B) contains at least one of a phosphorus-based antioxidant (B-1), a phenol-based antioxidant (B-2), and a phosphorus-phenolic antioxidant (B-3).
スチレン系樹脂組成物は、スチレン系樹脂１００質量部に対して、リン系酸化防止剤（Ｂ－１）とリン・フェノール系酸化防止剤（Ｂ－３）を合計で０．００１～０．５質量部含有し、好ましくは０．０５～０．３質量部含有する。このような範囲とすることで、光拡散板は長期耐久性及び強度に優れる。リン系酸化防止剤（Ｂ－１）とリン・フェノール系酸化防止剤（Ｂ－３）の合計の含有量は、具体的には、スチレン系樹脂１００質量部に対して、０．００１，０．００５，０．０１，０．０２，０．０３，０．０４，０．０５，０．１，０．１５，０．２，０．２５，０．３，０．３５，０．４，０．４５，０．５質量部であり、ここで例示した数値の何れか２つの間の範囲内であってもよい。
The styrene-based resin composition contains a total of 0.001 to 0.5 of a phosphorus-based antioxidant (B-1) and a phosphorus-phenol-based antioxidant (B-3) with respect to 100 parts by mass of the styrene-based resin. It is contained in parts by mass, preferably 0.05 to 0.3 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength. Specifically, the total content of the phosphorus-based antioxidant (B-1) and the phosphorus-phenolic antioxidant (B-3) is 0.001,0 with respect to 100 parts by mass of the styrene-based resin. .005,0.01,0.02,0.03,0.04,0.05,0.1,0.15,0.2,0.25,0.3,0.35,0.4 , 0.45, 0.5 parts by mass, and may be within the range between any two of the numerical values exemplified here.
フェノール系酸化防止剤（Ｂ－２）とリン・フェノール系酸化防止剤（Ｂ－３）を合計で０．００１～０．５質量部含有し、好ましくは０．０２～０．３質量部含有し、より好ましくは０．０５～０．１５質量部含有する。このような範囲とすることで、光拡散板は長期耐久性及び強度に優れる。フェノール系酸化防止剤（Ｂ－２）とリン・フェノール系酸化防止剤（Ｂ－３）の合計の含有量は、具体的には、スチレン系樹脂１００質量部に対して、０．００１，０．００５，０．０１，０．０２，０．０３，０．０４，０．０５，０．１，０．１５，０．２，０．２５，０．３，０．３５，０．４，０．４５，０．５質量部であり、ここで例示した数値の何れか２つの間の範囲内であってもよい。
A total of 0.001 to 0.5 parts by mass of a phenolic antioxidant (B-2) and a phosphorus / phenolic antioxidant (B-3) is contained, preferably 0.02 to 0.3 parts by mass. It is more preferably contained in an amount of 0.05 to 0.15 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength. Specifically, the total content of the phenolic antioxidant (B-2) and the phosphorus / phenolic antioxidant (B-3) is 0.001,0 with respect to 100 parts by mass of the styrene resin. .005,0.01,0.02,0.03,0.04,0.05,0.1,0.15,0.2,0.25,0.3,0.35,0.4 , 0.45, 0.5 parts by mass, and may be within the range between any two of the numerical values exemplified here.
リン系酸化防止剤（Ｂ－１）とは、基本骨格にフェノール性水酸基を有しない（亜）リン酸エステル類であり、好ましくは三価のリン化合物である亜リン酸エステル類である。リン系酸化防止剤（Ｂ－１）は、例えば、２，２'－メチレンビス（４，６－ジ－ｔｅｒｔ－ブチル－１－フェニルオキシ）（２－エチルヘキシルオキシ）ホスホラス、トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）フォスファイト、３，９－ビス（２，６－ジ―ｔｅｒｔ－ブチル―４－メチルフェノキシ）－２，４，８，１０－テトラオキサ―３，９－ジホスファスピロ〔５，５〕ウンデカン、テトラキス（２，４－ジ―ｔｅｒｔ－ブチルフェニル）〔１，１ビフェニル〕―４，４'ジイルビスホスホナイト、ビス（２，４－ジ―ｔｅｒｔ－ブチル―６－メチルフェニル）エチル亜リン酸エステル等から選ばれる少なくとも１種である。
The phosphorus-based antioxidant (B-1) is a (sub) phosphoric acid ester having no phenolic hydroxyl group in the basic skeleton, and is preferably a trivalent phosphorus compound, a phosphite ester. Phenyl antioxidants (B-1) include, for example, 2,2'-methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, tris (2,4-). Di-tert-butylphenyl) phosphite, 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5, 5] Undecane, tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite, bis (2,4-di-tert-butyl-6-methylphenyl) At least one selected from ethyl phosphite and the like.
フェノール系酸化防止剤（Ｂ－２）とは、基本骨格にフェノール性水酸基を持ち（亜）リン酸エステル類でない酸化防止剤である。フェノール系酸化防止剤（Ｂ－２）は、例えば、オクタデシル－３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート、エチレンビス（オキシエチレン）ビス〔３－（５－ｔｅｒｔ－ブチル－４－ヒドロキシ－ｍ－トリル）プロピオネート〕、ペンタエリスリトールテトラキス［３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート］、３，９－ビス［２－〔３－（３－ｔｅｒｔ－ブチル―４－ヒドロキシ―５－メチルフェニル）プロピオニルオキシ〕－１，１－ジメチルエチル］－２，４，８，１０－テトラオキサスピロ［５，５］ウンデカン等から選ばれる少なくとも１種である。
Phenolic antioxidant (B-2) is an antioxidant that has a phenolic hydroxyl group in its basic skeleton and is not a (sub) phosphate ester. Phenolic antioxidants (B-2) include, for example, octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and ethylenebis (oxyethylene) bis [3- (5-tert). -Butyl-4-hydroxy-m-tolyl) propionate], pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 3,9-bis [2- [3- [3-] (3-tert-Butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] At least selected from undecane and the like It is one kind.
リン・フェノール系酸化防止剤（Ｂ－３）は、基本骨格にフェノール性水酸基を持つ（亜）リン酸エステル類であり、好ましくは基本骨格にフェノール性水酸基を持つ三価のリン化合物である亜リン酸エステル類である。リン・フェノール系酸化防止剤（Ｂ－３）は、６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピン等である。
Phosphite-phenolic antioxidants (B-3) are (sub) phosphoric acid esters having a phenolic hydroxyl group in the basic skeleton, and preferably a trivalent phosphorus compound having a phenolic hydroxyl group in the basic skeleton. Phosphite esters. Phosphorus-phenolic antioxidant (B-3) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert- Butyldibenzo [d, f] [1,3,2] dioxaphosphepine and the like.
＜光拡散剤（Ｃ）＞
スチレン系樹脂組成物は、スチレン系樹脂１００質量部に対して、光拡散剤（Ｃ）を０．１～１０質量部含み、好ましくは０．５～３質量部含み、より好ましくは０．８～１．５質量部含む。このような範囲とすることで、光拡散板は長期耐久性及び強度に優れる。光拡散剤（Ｃ）の含有量は、具体的には、スチレン系樹脂１００質量部に対して、０．１，０．２，０．３，０．４，０．５，０．６，０．７，０．８，０．９，１．０、１．５、２、３、４、５、６、７、８、９、１０質量部であり、ここで例示した数値の何れか２つの間の範囲内であってもよい。 <Light diffuser (C)>
The styrene resin composition contains 0.1 to 10 parts by mass, preferably 0.5 to 3 parts by mass, and more preferably 0.8 of the light diffusing agent (C) with respect to 100 parts by mass of the styrene resin. Includes up to 1.5 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength. Specifically, the content of the light diffusing agent (C) is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, with respect to 100 parts by mass of the styrene resin. 0.7, 0.8, 0.9, 1.0, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10 parts by mass, and any of the numerical values exemplified here. It may be within the range between the two.
スチレン系樹脂組成物は、スチレン系樹脂１００質量部に対して、光拡散剤（Ｃ）を０．１～１０質量部含み、好ましくは０．５～３質量部含み、より好ましくは０．８～１．５質量部含む。このような範囲とすることで、光拡散板は長期耐久性及び強度に優れる。光拡散剤（Ｃ）の含有量は、具体的には、スチレン系樹脂１００質量部に対して、０．１，０．２，０．３，０．４，０．５，０．６，０．７，０．８，０．９，１．０、１．５、２、３、４、５、６、７、８、９、１０質量部であり、ここで例示した数値の何れか２つの間の範囲内であってもよい。 <Light diffuser (C)>
The styrene resin composition contains 0.1 to 10 parts by mass, preferably 0.5 to 3 parts by mass, and more preferably 0.8 of the light diffusing agent (C) with respect to 100 parts by mass of the styrene resin. Includes up to 1.5 parts by mass. Within such a range, the light diffusing plate is excellent in long-term durability and strength. Specifically, the content of the light diffusing agent (C) is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, with respect to 100 parts by mass of the styrene resin. 0.7, 0.8, 0.9, 1.0, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10 parts by mass, and any of the numerical values exemplified here. It may be within the range between the two.
光拡散剤（Ｃ）は、スチレン系樹脂組成物と屈折率が異なる粒子であって、入射する光を拡散する効果のあるものであれば用いることができるが、例えば、スチレン系重合体架橋粒子、アクリル系重合体架橋粒子、シロキサン系重合体架橋粒子などの有機粒子やガラスビーズ、シリカ粒子、水酸化アルミニウム粒子、炭酸カルシウム粒子、硫酸バリウム粒子、酸化チタン粒子、タルクなどの無機粒子を用いることができる。中でも、アクリル系重合体架橋粒子、スチレン系重合体架橋粒子、シロキサン系重合体架橋粒子から選ばれる少なくとも１種であることが好ましい。光拡散剤（Ｃ）の平均粒子径は、好ましくは１～２０μｍである。光拡散剤（Ｃ）の平均粒子径が１μｍ未満では、色相が悪化する場合があり、２０μｍを超えると、光拡散性の付与が十分でない場合がある。
The light diffusing agent (C) can be used as long as it is particles having a refractive index different from that of the styrene resin composition and has an effect of diffusing incident light. For example, styrene polymer crosslinked particles can be used. Use organic particles such as acrylic polymer crosslinked particles and siloxane polymer crosslinked particles, and inorganic particles such as glass beads, silica particles, aluminum hydroxide particles, calcium carbonate particles, barium sulfate particles, titanium oxide particles, and talc. Can be done. Among them, at least one selected from acrylic polymer crosslinked particles, styrene polymer crosslinked particles, and siloxane polymer crosslinked particles is preferable. The average particle size of the light diffusing agent (C) is preferably 1 to 20 μm. If the average particle size of the light diffusing agent (C) is less than 1 μm, the hue may deteriorate, and if it exceeds 20 μm, the light diffusing property may not be sufficiently imparted.
＜その他の添加剤＞
スチレン系樹脂組成物には、本発明の特性を損なわない範囲で、必要に応じて種々の添加剤を配合することができる。添加剤の種類はプラスチックに一般的に用いられるものであれば特に制限はないが、難燃剤、滑剤、加工助剤、ブロッキング防止剤、帯電防止剤、防曇剤、耐光性向上剤、軟化剤、可塑剤、無機補強剤、架橋剤、顔料、染料、その他或いはこれらの混合物が挙げられる。 <Other additives>
Various additives can be added to the styrene resin composition, if necessary, as long as the characteristics of the present invention are not impaired. The type of additive is not particularly limited as long as it is generally used for plastics, but it is a flame retardant, a lubricant, a processing aid, an antiblocking agent, an antistatic agent, an antifogging agent, a light resistance improver, and a softening agent. , Plasticizers, inorganic reinforcing agents, cross-linking agents, pigments, dyes, etc., or mixtures thereof.
スチレン系樹脂組成物には、本発明の特性を損なわない範囲で、必要に応じて種々の添加剤を配合することができる。添加剤の種類はプラスチックに一般的に用いられるものであれば特に制限はないが、難燃剤、滑剤、加工助剤、ブロッキング防止剤、帯電防止剤、防曇剤、耐光性向上剤、軟化剤、可塑剤、無機補強剤、架橋剤、顔料、染料、その他或いはこれらの混合物が挙げられる。 <Other additives>
Various additives can be added to the styrene resin composition, if necessary, as long as the characteristics of the present invention are not impaired. The type of additive is not particularly limited as long as it is generally used for plastics, but it is a flame retardant, a lubricant, a processing aid, an antiblocking agent, an antistatic agent, an antifogging agent, a light resistance improver, and a softening agent. , Plasticizers, inorganic reinforcing agents, cross-linking agents, pigments, dyes, etc., or mixtures thereof.
２．スチレン系樹脂組成物及び光拡散板の製造方法
本発明のスチレン系樹脂組成物は、スチレン系樹脂（Ａ）に酸化防止剤（Ｂ）と、光拡散剤（Ｃ）を添加することによって製造可能である。酸化防止剤（Ｂ）、及び、光拡散剤（Ｃ）は、スチレン系樹脂（Ａ）の重合時に添加してもよいし、スチレン系樹脂（Ａ）を重合後、酸化防止剤（Ｂ）と光拡散剤（Ｃ）をドライブレンドし、押出機で溶融混練して製造してもよい。また、酸化防止剤（Ｂ）、光拡散剤（Ｃ）を、予め少量のスチレン系樹脂と共に溶融混錬して得たペレット状のマスターバッチを作成し、スチレン系樹脂（Ａ）と該マスターバッチとをドライブレンド後、溶融混練し、調整してもよい。 2. Method for Producing Styrene-based Resin Composition and Light Diffusing Plate The styrene-based resin composition of the present invention can be manufactured by adding an antioxidant (B) and a light diffusing agent (C) to a styrene resin (A). Is. The antioxidant (B) and the light diffusing agent (C) may be added at the time of polymerization of the styrene resin (A), or after the styrene resin (A) is polymerized, the antioxidant (B) and the antioxidant (B) may be added. The light diffusing agent (C) may be dry-blended and melt-kneaded with an extruder to produce the product. Further, a pellet-shaped masterbatch obtained by melting and kneading the antioxidant (B) and the light diffusing agent (C) together with a small amount of styrene resin in advance was prepared, and the styrene resin (A) and the masterbatch were prepared. And may be dry-blended and then melt-kneaded for adjustment.
本発明のスチレン系樹脂組成物は、スチレン系樹脂（Ａ）に酸化防止剤（Ｂ）と、光拡散剤（Ｃ）を添加することによって製造可能である。酸化防止剤（Ｂ）、及び、光拡散剤（Ｃ）は、スチレン系樹脂（Ａ）の重合時に添加してもよいし、スチレン系樹脂（Ａ）を重合後、酸化防止剤（Ｂ）と光拡散剤（Ｃ）をドライブレンドし、押出機で溶融混練して製造してもよい。また、酸化防止剤（Ｂ）、光拡散剤（Ｃ）を、予め少量のスチレン系樹脂と共に溶融混錬して得たペレット状のマスターバッチを作成し、スチレン系樹脂（Ａ）と該マスターバッチとをドライブレンド後、溶融混練し、調整してもよい。 2. Method for Producing Styrene-based Resin Composition and Light Diffusing Plate The styrene-based resin composition of the present invention can be manufactured by adding an antioxidant (B) and a light diffusing agent (C) to a styrene resin (A). Is. The antioxidant (B) and the light diffusing agent (C) may be added at the time of polymerization of the styrene resin (A), or after the styrene resin (A) is polymerized, the antioxidant (B) and the antioxidant (B) may be added. The light diffusing agent (C) may be dry-blended and melt-kneaded with an extruder to produce the product. Further, a pellet-shaped masterbatch obtained by melting and kneading the antioxidant (B) and the light diffusing agent (C) together with a small amount of styrene resin in advance was prepared, and the styrene resin (A) and the masterbatch were prepared. And may be dry-blended and then melt-kneaded for adjustment.
スチレン系樹脂の重合方法としては、塊状重合法、溶液重合法、懸濁重合法、乳化重合法等公知のスチレン重合方法が挙げられる。品質面や生産性の面では、塊状重合法、溶液重合法が好ましく、連続重合であることが好ましい。溶媒として例えばベンゼン、トルエン、エチルベンゼン及びキシレン等のアルキルベンゼン類やアセトンやメチルエチルケトン等のケトン類、ヘキサンやシクロヘキサン等の脂肪族炭化水素等が使用できる。
Examples of the polymerization method of the styrene resin include known styrene polymerization methods such as a massive polymerization method, a solution polymerization method, a suspension polymerization method, and an emulsion polymerization method. From the viewpoint of quality and productivity, the bulk polymerization method and the solution polymerization method are preferable, and continuous polymerization is preferable. As the solvent, for example, alkylbenzenes such as benzene, toluene, ethylbenzene and xylene, ketones such as acetone and methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and cyclohexane can be used.
スチレン系樹脂（Ａ）の重合時に、必要に応じて重合開始剤、連鎖移動剤、架橋剤などの重合助剤、その他の重合助剤を使用することができる。重合開始剤としては、ラジカル重合開始剤が好ましく、公知慣用の例えば、１，１－ジ（ｔ－ブチルパーオキシ）シクロヘキサン、２，２－ジ（ｔ－ブチルパーオキシ）ブタン、２，２－ジ（４，４－ジ－ｔ－ブチルパーオキシシクロヘキシル）プロパン、１，１－ジ（ｔ－アミルパーオキシ）シクロヘキサン等のパーオキシケタール類、クメンハイドロパーオキサイド、ｔ－ブチルハイドロパーオキサイド等のハイドロパーオキサイド類、ｔ－ブチルパーオキシアセテート、ｔ－アミルパーオキシイソノナノエート等のアルキルパーオキサイド類、ｔ－ブチルクミルパーオキサイド、ジ－ｔ－ブチルパーオキサイド、ジクミルパーオキサイド、ジ－ｔ－ヘキシルパーオキサイド等のジアルキルパーオキサイド類、ｔ－ブチルパーオキシアセテート、ｔ－ブチルパーオキシベンゾエート、ｔ－ブチルパーオキシイソプロピルモノカーボネート等のパーオキシエステル類、ｔ－ブチルパーオキシイソプロピルカーボネート、ポリエーテルテトラキス（ｔ－ブチルパーオキシカーボネート）等のパーオキシカーボネート類、Ｎ，Ｎ'－アゾビス（シクロヘキサン－１－カルボニトリル）、Ｎ，Ｎ'－アゾビス（２－メチルブチロニトリル）、Ｎ，Ｎ'－アゾビス（２，４－ジメチルバレロニトリル）、Ｎ，Ｎ'－アゾビス［２－（ヒドロキシメチル）プロピオニトリル］等が挙げられ、これらの１種あるいは２種以上を組み合わせて使用することができる。連鎖移動剤としては、脂肪族メルカプタン、芳香族メルカプタン、ペンタフェニルエタン、α－メチルスチレンダイマー及びテルピノーレン等が挙げられる。
When the styrene resin (A) is polymerized, a polymerization initiator, a chain transfer agent, a cross-linking agent and other polymerization aids, and other polymerization aids can be used, if necessary. As the polymerization initiator, a radical polymerization initiator is preferable, and for example, 1,1-di (t-butylperoxy) cyclohexane, 2,2-di (t-butylperoxy) butane, 2,2-di (t-butylperoxy) butane, which are known and commonly used, are preferable. Peroxyketals such as di (4,5-di-t-butylperoxycyclohexyl) propane, 1,1-di (t-amylperoxy) cyclohexane, cumenehydroperoxide, t-butylhydroperoxide and the like. Hydroperoxides, alkyl peroxides such as t-butylperoxyacetate, t-amylperoxyisononanoate, t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, di-t -Dialkyl peroxides such as hexyl peroxide, peroxyesters such as t-butyl peroxyacetate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxyisopropyl carbonate, polyether Peroxycarbonates such as tetrakis (t-butylperoxycarbonate), N, N'-azobis (cyclohexane-1-carbonitrile), N, N'-azobis (2-methylbutyronitrile), N, N' -Azobis (2,4-dimethylvaleronitrile), N, N'-azobis [2- (hydroxymethyl) propionitrile] and the like can be mentioned, and one or a combination of two or more of these can be used. .. Examples of the chain transfer agent include aliphatic mercaptans, aromatic mercaptans, pentaphenylethane, α-methylstyrene dimer and terpinolene.
連続重合の場合、スチレン系樹脂は、重合工程と、脱揮工程、造粒工程を備える方法によって製造可能である。
In the case of continuous polymerization, the styrene resin can be produced by a method including a polymerization step, a volatilization step, and a granulation step.
まず重合工程にて公知の完全混合槽型攪拌槽や塔型反応器等を用い、目標の分子量、分子量分布、反応転化率となるよう、重合温度調整等により重合反応が制御される。
First, in the polymerization step, a known complete mixing tank type stirring tank, a tower reactor, or the like is used, and the polymerization reaction is controlled by adjusting the polymerization temperature or the like so as to obtain the target molecular weight, molecular weight distribution, and reaction conversion rate.
重合工程を出た重合体を含む重合溶液は、脱揮工程に移送され、未反応の単量体及び重合溶媒が除去される。脱揮工程は加熱器付きの真空脱揮槽やベント付き脱揮押出機などで構成される。脱揮工程を出た溶融状態の重合体は造粒工程へ移送される。造粒工程では、多孔ダイよりストランド状に溶融樹脂を押出し、コールドカット方式や空中ホットカット方式、水中ホットカット方式にてペレット形状に加工される。
The polymerization solution containing the polymer that has left the polymerization step is transferred to the devolatile step, and the unreacted monomer and the polymerization solvent are removed. The devolatilization process consists of a vacuum devolatilization tank with a heater and a devolatilization extruder with a vent. The molten polymer that has left the devolatile step is transferred to the granulation step. In the granulation process, the molten resin is extruded into a strand shape from a porous die and processed into a pellet shape by a cold cut method, an aerial hot cut method, or an underwater hot cut method.
スチレン系樹脂組成物中のｔ－ブチルカテコールの含有量は、スチレン系樹脂（Ａ）の重合開始時における含有量の調整及びその後の脱揮工程等における含有量の調整が可能である。また、スチレン系樹脂（Ａ）にスチレン系樹脂（Ａ）、酸化防止剤（Ｂ）、光拡散剤（Ｃ）等を添加する前後に添加して調整してもよい。
The content of t-butylcatechol in the styrene resin composition can be adjusted at the start of polymerization of the styrene resin (A) and in the subsequent devolatile step. Further, the styrene resin (A) may be adjusted by adding the styrene resin (A), the antioxidant (B), the light diffusing agent (C) and the like before and after the addition.
光拡散板は、スチレン系樹脂組成物を、押出成形、射出成形等、種々の方法により成形することにより製造可能であるが、好ましくは押出成形によって製造する。押出成形の例としては、スチレン系樹脂組成物を単軸押出機、または二軸押出機を用いて溶融混錬し、Ｔダイスより連続的に押出し後、冷却ロールユニットにより冷却固化する方法が上げられる。光拡散板の表面に凹凸形状を形成させる場合には、冷却ロールの表面に転写型を備え、該転写型の形状を変更することで、任意の凹凸形状を形成させることができる。また、光拡散板の両面、片面に表面層を積層する場合には、共押出法、貼付法、熱接着法、溶剤接着法、キャスト法、表面塗布法等の方法を採用することができる。
The light diffusing plate can be manufactured by molding a styrene resin composition by various methods such as extrusion molding and injection molding, but is preferably manufactured by extrusion molding. An example of extrusion molding is a method in which a styrene resin composition is melt-kneaded using a single-screw extruder or a twin-screw extruder, continuously extruded from a T die, and then cooled and solidified by a cooling roll unit. Be done. When forming an uneven shape on the surface of the light diffusing plate, an arbitrary uneven shape can be formed by providing a transfer mold on the surface of the cooling roll and changing the shape of the transfer mold. Further, when the surface layer is laminated on both sides or one side of the light diffusing plate, a method such as a coextrusion method, a sticking method, a heat bonding method, a solvent bonding method, a casting method, or a surface coating method can be adopted.
３．その他
本発明の一実施形態にかかる光拡散板は、ＬＥＤ光源用光拡散板として用いることができる。
また、本発明の一実施形態にかかる直下型面光源ユニットは、上記光拡散板を有する直下型面光源ユニットである。 3. 3. Others The light diffusing plate according to the embodiment of the present invention can be used as a light diffusing plate for an LED light source.
Further, the direct type surface light source unit according to the embodiment of the present invention is a direct type surface light source unit having the above-mentioned light diffusing plate.
本発明の一実施形態にかかる光拡散板は、ＬＥＤ光源用光拡散板として用いることができる。
また、本発明の一実施形態にかかる直下型面光源ユニットは、上記光拡散板を有する直下型面光源ユニットである。 3. 3. Others The light diffusing plate according to the embodiment of the present invention can be used as a light diffusing plate for an LED light source.
Further, the direct type surface light source unit according to the embodiment of the present invention is a direct type surface light source unit having the above-mentioned light diffusing plate.
以下に実施例をあげて本発明を更に詳細に説明する。また、これらはいずれも例示的なものであって、本発明の内容を限定するものではない。
The present invention will be described in more detail with reference to examples below. Moreover, these are merely examples and do not limit the content of the present invention.
１． 測定方法
＜分子量＞
数平均分子量（Ｍｎ）、重量平均分子量（Ｍｗ）及びＺ平均分子量（Ｍｚは、ゲルパーミエイションクロマトグラフィー（ＧＰＣ）を用いて、次の条件で測定した。
ＧＰＣ機種：昭和電工株式会社製Ｓｈｏｄｅｘ ＧＰＣ－１０１
カラム：ポリマーラボラトリーズ社製 ＰＬｇｅｌ １０μｍ ＭＩＸＥＤ－Ｂ
移動相：テトラヒドロフラン
試料濃度：０．２質量％
温度：オーブン４０℃、注入口３５℃、検出器３５℃
検出器：示差屈折計
分子量は単分散ポリスチレンの溶出曲線より各溶出時間における分子量を算出し、ポリスチレン換算の分子量として算出したものである。 1. 1. Measurement method <Molecular weight>
The number average molecular weight (Mn), the weight average molecular weight (Mw), and the Z average molecular weight (Mz were measured by gel permeation chromatography (GPC) under the following conditions.
GPC model: Showa Denko Corporation Shodex GPC-101
Column: Polymer Laboratories PLgel 10 μm MIXED-B
Mobile phase: tetrahydrofuran Sample concentration: 0.2% by mass
Temperature: Oven 40 ° C, inlet 35 ° C, detector 35 ° C
Detector: Differential refractometer The molecular weight is calculated as the polystyrene-equivalent molecular weight by calculating the molecular weight at each elution time from the elution curve of monodisperse polystyrene.
＜分子量＞
数平均分子量（Ｍｎ）、重量平均分子量（Ｍｗ）及びＺ平均分子量（Ｍｚは、ゲルパーミエイションクロマトグラフィー（ＧＰＣ）を用いて、次の条件で測定した。
ＧＰＣ機種：昭和電工株式会社製Ｓｈｏｄｅｘ ＧＰＣ－１０１
カラム：ポリマーラボラトリーズ社製 ＰＬｇｅｌ １０μｍ ＭＩＸＥＤ－Ｂ
移動相：テトラヒドロフラン
試料濃度：０．２質量％
温度：オーブン４０℃、注入口３５℃、検出器３５℃
検出器：示差屈折計
分子量は単分散ポリスチレンの溶出曲線より各溶出時間における分子量を算出し、ポリスチレン換算の分子量として算出したものである。 1. 1. Measurement method <Molecular weight>
The number average molecular weight (Mn), the weight average molecular weight (Mw), and the Z average molecular weight (Mz were measured by gel permeation chromatography (GPC) under the following conditions.
GPC model: Showa Denko Corporation Shodex GPC-101
Column: Polymer Laboratories PLgel 10 μm MIXED-B
Mobile phase: tetrahydrofuran Sample concentration: 0.2% by mass
Temperature: Oven 40 ° C, inlet 35 ° C, detector 35 ° C
Detector: Differential refractometer The molecular weight is calculated as the polystyrene-equivalent molecular weight by calculating the molecular weight at each elution time from the elution curve of monodisperse polystyrene.
＜メルトマスフローレート（ＭＦＲ）＞
ＪＩＳ Ｋ ７２１０に従って、温度２００℃、４９Ｎ荷重の条件で測定した。 <Melt mass flow rate (MFR)>
According to JIS K 7210, the measurement was performed under the conditions of a temperature of 200 ° C. and a load of 49 N.
ＪＩＳ Ｋ ７２１０に従って、温度２００℃、４９Ｎ荷重の条件で測定した。 <Melt mass flow rate (MFR)>
According to JIS K 7210, the measurement was performed under the conditions of a temperature of 200 ° C. and a load of 49 N.
＜ビカット軟化温度＞
ＪＩＳ Ｋ ７２０６に従って、昇温速度５０℃／ｈｒ、試験荷重５０Ｎで測定した。 <Vicat softening temperature>
According to JIS K 7206, the measurement was performed at a heating rate of 50 ° C./hr and a test load of 50 N.
ＪＩＳ Ｋ ７２０６に従って、昇温速度５０℃／ｈｒ、試験荷重５０Ｎで測定した。 <Vicat softening temperature>
According to JIS K 7206, the measurement was performed at a heating rate of 50 ° C./hr and a test load of 50 N.
＜ｔ－ブチルカテコール（ＴＢＣ）の含有量＞
スチレン系樹脂０．２ｇを少量のＴＨＦに溶解した後、ＢＳＴＦＡ（Ｍ，Ｏ－ビス（トリメチルシリル）トリフルオロアセトアミド）２００μＬを添加し、トリメチルシリル誘導体化処理を実施し、ＴＨＦにて１０ｍＬ定容した後、遠心分離によって分離した上澄み液について、ガスクロマトグラフ質量分析（ＧＣ／ＭＳ）にて、以下の条件で測定した。なお、濃度の決定には、予め作成した検量線を用いた。
ＧＣ装置 ：Ａｇｉｌｅｎｔ社製 ７８９０Ａ
カラム ：Ａｇｉｌｅｎｔ社製 ＤＢ－５ｍｓ（０．２５ｍｍ ｉ．ｄ．×３０ｍ）
液相膜厚０．２５μｍ
カラム温度：５０℃（１ｍｉｎ）→（２０℃／ｍｉｎ昇温）→
３２０℃（６．５ｍｉｎ）計２０ｍｉｎ
注入口 ：３００℃、１．５ｍＬ／ｍｉｎ、（スプリット比１：５）
注入量 ：１μＬ
ＭＳ装置 ：Ａｇｉｌｅｎｔ社製 ５９７５Ｃ
インターフェイス温度：３２０℃
ＭＳ検出条件：ＳＩＭ測定 ＴＢＣ（定量用ｍ／ｚ ２９５、確認用ｍ／ｚ ３１０） <Content of t-butylcatechol (TBC)>
After dissolving 0.2 g of styrene resin in a small amount of THF, 200 μL of BSTFA (M, O-bis (trimethylsilyl) trifluoroacetamide) was added, trimethylsilyl derivatization treatment was performed, and 10 mL of the volume was adjusted with THF. The supernatant separated by centrifugation was measured by gas chromatograph mass spectrometry (GC / MS) under the following conditions. A calibration curve prepared in advance was used to determine the concentration.
GC device: Agilent 7890A
Column: Agilent DB-5ms (0.25mm id x 30m)
Liquid phase film thickness 0.25 μm
Column temperature: 50 ° C (1 min) → (20 ° C / min temperature rise) →
320 ° C (6.5 min) 20 min in total
Injection port: 300 ° C, 1.5 mL / min, (split ratio 1: 5)
Injection volume: 1 μL
MS device: Agilent 5975C
Interface temperature: 320 ° C
MS detection conditions: SIM measurement TBC (quantitative m / z 295, confirmation m / z 310)
スチレン系樹脂０．２ｇを少量のＴＨＦに溶解した後、ＢＳＴＦＡ（Ｍ，Ｏ－ビス（トリメチルシリル）トリフルオロアセトアミド）２００μＬを添加し、トリメチルシリル誘導体化処理を実施し、ＴＨＦにて１０ｍＬ定容した後、遠心分離によって分離した上澄み液について、ガスクロマトグラフ質量分析（ＧＣ／ＭＳ）にて、以下の条件で測定した。なお、濃度の決定には、予め作成した検量線を用いた。
ＧＣ装置 ：Ａｇｉｌｅｎｔ社製 ７８９０Ａ
カラム ：Ａｇｉｌｅｎｔ社製 ＤＢ－５ｍｓ（０．２５ｍｍ ｉ．ｄ．×３０ｍ）
液相膜厚０．２５μｍ
カラム温度：５０℃（１ｍｉｎ）→（２０℃／ｍｉｎ昇温）→
３２０℃（６．５ｍｉｎ）計２０ｍｉｎ
注入口 ：３００℃、１．５ｍＬ／ｍｉｎ、（スプリット比１：５）
注入量 ：１μＬ
ＭＳ装置 ：Ａｇｉｌｅｎｔ社製 ５９７５Ｃ
インターフェイス温度：３２０℃
ＭＳ検出条件：ＳＩＭ測定 ＴＢＣ（定量用ｍ／ｚ ２９５、確認用ｍ／ｚ ３１０） <Content of t-butylcatechol (TBC)>
After dissolving 0.2 g of styrene resin in a small amount of THF, 200 μL of BSTFA (M, O-bis (trimethylsilyl) trifluoroacetamide) was added, trimethylsilyl derivatization treatment was performed, and 10 mL of the volume was adjusted with THF. The supernatant separated by centrifugation was measured by gas chromatograph mass spectrometry (GC / MS) under the following conditions. A calibration curve prepared in advance was used to determine the concentration.
GC device: Agilent 7890A
Column: Agilent DB-5ms (0.25mm id x 30m)
Liquid phase film thickness 0.25 μm
Column temperature: 50 ° C (1 min) → (20 ° C / min temperature rise) →
320 ° C (6.5 min) 20 min in total
Injection port: 300 ° C, 1.5 mL / min, (split ratio 1: 5)
Injection volume: 1 μL
MS device: Agilent 5975C
Interface temperature: 320 ° C
MS detection conditions: SIM measurement TBC (quantitative m / z 295, confirmation m / z 310)
＜全光線透過率、ＹＩ＞
日本電色工業社製 濁度計ＮＤＨ５０００を用いて、ＪＩＳ－Ｋ７１０５に準拠し、光拡散板の厚み方向の全光線透過率を測定した。 <Total light transmittance, YI>
Using a turbidity meter NDH5000 manufactured by Nippon Denshoku Kogyo Co., Ltd., the total light transmittance in the thickness direction of the light diffusing plate was measured in accordance with JIS-K7105.
日本電色工業社製 濁度計ＮＤＨ５０００を用いて、ＪＩＳ－Ｋ７１０５に準拠し、光拡散板の厚み方向の全光線透過率を測定した。 <Total light transmittance, YI>
Using a turbidity meter NDH5000 manufactured by Nippon Denshoku Kogyo Co., Ltd., the total light transmittance in the thickness direction of the light diffusing plate was measured in accordance with JIS-K7105.
＜ＹＩ＞
日本電色工業社製 測色色度計ＮＤＪ４０００を用いて、ＪＩＳ－Ｋ７１０５に準拠し、反射法により、光拡散板のＹＩを測定した。 <YI>
The YI of the light diffusing plate was measured by the reflection method using a colorimetric chromaticity meter NDJ4000 manufactured by Nippon Denshoku Kogyo Co., Ltd. in accordance with JIS-K7105.
日本電色工業社製 測色色度計ＮＤＪ４０００を用いて、ＪＩＳ－Ｋ７１０５に準拠し、反射法により、光拡散板のＹＩを測定した。 <YI>
The YI of the light diffusing plate was measured by the reflection method using a colorimetric chromaticity meter NDJ4000 manufactured by Nippon Denshoku Kogyo Co., Ltd. in accordance with JIS-K7105.
＜平均輝度差＞
市販の２０インチ直下型ＬＥＤ液晶テレビから、液晶パネル、各種光学フィルム、光拡散板を取り出した後、この光拡散板の中央部を１１５ｍｍ×１１５ｍｍの正方形状にくり抜き、このくり抜いた部分に、実施例、比較例で得られた光拡散板を１１５ｍｍ×１１５ｍｍに切り出した評価試験片、若しくは、耐久試験後の１１５ｍｍ×１１５ｍｍの評価試験片を装着し、これを前記取り出し後の液晶テレビのフレームに装着した。その後、光拡散板の前面側に市販の光拡散フィルムを２枚重ね、更にその前面側に輝度向上フィルム（スリーエム社製「ＤＢＦＦ」）を１枚重ね合わせ、ＬＥＤを点灯した状態で、マルチポイント輝度計を用いて、液晶テレビの前面の全範囲にわたって、各スポット（５１×５１＝２６０１箇所）の輝度を測定し、これらの輝度の平均値を平均輝度（ｃｄ／ｍ２）とした。更に、下記式により、平均輝度差（％）を求めた。
平均輝度差（％）＝｛（実施例の平均輝度）－（比較例１の平均輝度）｝／（比較例１の平均輝度）×１００ <Average brightness difference>
After taking out the liquid crystal panel, various optical films, and the light diffusing plate from a commercially available 20-inch direct-type LED liquid crystal TV, the central part of the light diffusing plate is hollowed out in a square shape of 115 mm × 115 mm, and the hollowed out portion is used. For example, an evaluation test piece obtained by cutting out the light diffusing plate obtained in the comparative example to 115 mm × 115 mm or an evaluation test piece of 115 mm × 115 mm after the durability test is attached, and this is attached to the frame of the liquid crystal television after taking out. I put it on. After that, two commercially available light diffusing films are laminated on the front side of the light diffusing plate, and one brightness improving film (“DBFF” manufactured by 3M Co., Ltd.) is further laminated on the front side thereof. The brightness of each spot (51 × 51 = 2601 points) was measured over the entire range of the front surface of the LCD TV using a luminance meter, and the average value of these luminances was taken as the average luminance (cd / m 2 ). Further, the average luminance difference (%) was calculated by the following formula.
Average brightness difference (%) = {(average brightness of Example)-(average brightness of Comparative Example 1)} / (average brightness of Comparative Example 1) × 100
市販の２０インチ直下型ＬＥＤ液晶テレビから、液晶パネル、各種光学フィルム、光拡散板を取り出した後、この光拡散板の中央部を１１５ｍｍ×１１５ｍｍの正方形状にくり抜き、このくり抜いた部分に、実施例、比較例で得られた光拡散板を１１５ｍｍ×１１５ｍｍに切り出した評価試験片、若しくは、耐久試験後の１１５ｍｍ×１１５ｍｍの評価試験片を装着し、これを前記取り出し後の液晶テレビのフレームに装着した。その後、光拡散板の前面側に市販の光拡散フィルムを２枚重ね、更にその前面側に輝度向上フィルム（スリーエム社製「ＤＢＦＦ」）を１枚重ね合わせ、ＬＥＤを点灯した状態で、マルチポイント輝度計を用いて、液晶テレビの前面の全範囲にわたって、各スポット（５１×５１＝２６０１箇所）の輝度を測定し、これらの輝度の平均値を平均輝度（ｃｄ／ｍ２）とした。更に、下記式により、平均輝度差（％）を求めた。
平均輝度差（％）＝｛（実施例の平均輝度）－（比較例１の平均輝度）｝／（比較例１の平均輝度）×１００ <Average brightness difference>
After taking out the liquid crystal panel, various optical films, and the light diffusing plate from a commercially available 20-inch direct-type LED liquid crystal TV, the central part of the light diffusing plate is hollowed out in a square shape of 115 mm × 115 mm, and the hollowed out portion is used. For example, an evaluation test piece obtained by cutting out the light diffusing plate obtained in the comparative example to 115 mm × 115 mm or an evaluation test piece of 115 mm × 115 mm after the durability test is attached, and this is attached to the frame of the liquid crystal television after taking out. I put it on. After that, two commercially available light diffusing films are laminated on the front side of the light diffusing plate, and one brightness improving film (“DBFF” manufactured by 3M Co., Ltd.) is further laminated on the front side thereof. The brightness of each spot (51 × 51 = 2601 points) was measured over the entire range of the front surface of the LCD TV using a luminance meter, and the average value of these luminances was taken as the average luminance (cd / m 2 ). Further, the average luminance difference (%) was calculated by the following formula.
Average brightness difference (%) = {(average brightness of Example)-(average brightness of Comparative Example 1)} / (average brightness of Comparative Example 1) × 100
＜拡散率＞
オプテック社製 ゴニオフォトメーターを用いて、白色光の光源から光拡散板の表面に直角方向に入光させ、透過した光を、光拡散板の表面に直角方向を０度として、５度、２０度、７０度における輝度を測定し、下記式により拡散率を求めた。
光拡散率（％）＝（２０度の輝度＋７０度の輝度）／（５度の輝度×２）×１００ <Diffusivity>
Using a Gonio photometer manufactured by Optech, light enters from a white light source in a direction perpendicular to the surface of the light diffuser plate, and the transmitted light is taken as 0 degree in the direction perpendicular to the surface of the light diffuser plate, 5 degrees, 20 degrees. The brightness at 70 degrees was measured, and the diffusion rate was calculated by the following formula.
Light diffusion rate (%) = (20 degree brightness + 70 degree brightness) / (5 degree brightness x 2) x 100
オプテック社製 ゴニオフォトメーターを用いて、白色光の光源から光拡散板の表面に直角方向に入光させ、透過した光を、光拡散板の表面に直角方向を０度として、５度、２０度、７０度における輝度を測定し、下記式により拡散率を求めた。
光拡散率（％）＝（２０度の輝度＋７０度の輝度）／（５度の輝度×２）×１００ <Diffusivity>
Using a Gonio photometer manufactured by Optech, light enters from a white light source in a direction perpendicular to the surface of the light diffuser plate, and the transmitted light is taken as 0 degree in the direction perpendicular to the surface of the light diffuser plate, 5 degrees, 20 degrees. The brightness at 70 degrees was measured, and the diffusion rate was calculated by the following formula.
Light diffusion rate (%) = (20 degree brightness + 70 degree brightness) / (5 degree brightness x 2) x 100
＜強度＞
光拡散板を、２００ｍｍ×２００ｍｍに正方形状に切り出し、評価試験片とした。重量１６．６ｇの球を使用し、ＪＩＳ Ｋ－７２１１に従って、５０％破壊高さを測定し、以下の基準により評価した。
○：５０％破壊高さが４０ｃｍ超
△：５０％破壊高さが２０～４０ｃｍ
×：５０％破壊高さが２０ｃｍ未満 <Strength>
The light diffusing plate was cut into a square shape of 200 mm × 200 mm and used as an evaluation test piece. Using a ball weighing 16.6 g, a 50% fracture height was measured according to JIS K-7211 and evaluated according to the following criteria.
◯: 50% destruction height exceeds 40 cm Δ: 50% destruction height is 20 to 40 cm
X: 50% destruction height is less than 20 cm
光拡散板を、２００ｍｍ×２００ｍｍに正方形状に切り出し、評価試験片とした。重量１６．６ｇの球を使用し、ＪＩＳ Ｋ－７２１１に従って、５０％破壊高さを測定し、以下の基準により評価した。
○：５０％破壊高さが４０ｃｍ超
△：５０％破壊高さが２０～４０ｃｍ
×：５０％破壊高さが２０ｃｍ未満 <Strength>
The light diffusing plate was cut into a square shape of 200 mm × 200 mm and used as an evaluation test piece. Using a ball weighing 16.6 g, a 50% fracture height was measured according to JIS K-7211 and evaluated according to the following criteria.
◯: 50% destruction height exceeds 40 cm Δ: 50% destruction height is 20 to 40 cm
X: 50% destruction height is less than 20 cm
２．耐久試験
光拡散板を１１５ｍｍ×１１５ｍｍに切り出した後、評価試験片を楠本化成製ギアオーブンＨＩＳＰＥＣ ＨＴ３１０を用いて、温度を８０℃に設定した槽内で、１，０００時間暴露した。 2. Durability test After cutting out the light diffusing plate to 115 mm × 115 mm, the evaluation test piece was exposed for 1,000 hours in a tank set at a temperature of 80 ° C. using a gear oven HISPEC HT310 manufactured by Kusumoto Kasei.
光拡散板を１１５ｍｍ×１１５ｍｍに切り出した後、評価試験片を楠本化成製ギアオーブンＨＩＳＰＥＣ ＨＴ３１０を用いて、温度を８０℃に設定した槽内で、１，０００時間暴露した。 2. Durability test After cutting out the light diffusing plate to 115 mm × 115 mm, the evaluation test piece was exposed for 1,000 hours in a tank set at a temperature of 80 ° C. using a gear oven HISPEC HT310 manufactured by Kusumoto Kasei.
長期耐久性の結果については、上記耐久試験後の各測定の結果を示している。
Regarding the results of long-term durability, the results of each measurement after the above durability test are shown.
３．スチレン系樹脂の合成
スチレン系樹脂ＰＳ－１～ＰＳ－５を表１の各条件に従い合成した。 3. 3. Synthesis of Styrene-based Resins Styrene-based resins PS-1 to PS-5 were synthesized according to the conditions shown in Table 1.
スチレン系樹脂ＰＳ－１～ＰＳ－５を表１の各条件に従い合成した。 3. 3. Synthesis of Styrene-based Resins Styrene-based resins PS-1 to PS-5 were synthesized according to the conditions shown in Table 1.
（ＰＳ－１の合成）
完全混合型撹拌槽である第１反応器と第２反応器及び静的混合器付プラグフロー型反応器である第３反応器を直列に接続して重合工程を構成し、表１に示す条件によりスチレン系樹脂の製造を実施した。各反応器の容量は、第１反応器を３９リットル、第２反応器を３９リットル、第３反応器を１６リットルとした。表１に記載の原料組成にて、原料溶液を作成し、第１反応器に原料溶液を表１に記載の流量にて連続的に供給した。重合開始剤は、第１反応器の入口で表１に記載の添加濃度（原料スチレンに対する質量基準の濃度）となるように原料溶液に添加し、均一混合した。表１に記載の重合開始剤は次の通りである。
重合開始剤－１ ：２，２－ジ（４，４－ｔ－ブチルパーオキシシクロヘキシル）プロパン（日油株式会社製パーテトラＡを使用した。）
重合開始剤－２ ：１，１－ジ（ｔ－ブチルパーオキシ）シクロヘキサン（日油株式会社製パーヘキサＣを使用した。）
なお、第３反応器では、流れの方向に沿って温度勾配をつけ、中間部分、出口部分で表１の温度となるよう調整した。
続いて、第３反応器より連続的に取り出した重合体を含む溶液を直列に２段より構成される予熱器付き真空脱揮槽に導入し、表１に記載の樹脂温度となるよう予熱器の温度を調整し、表１に記載の圧力に調整することで、未反応スチレン及びエチルベンゼンを分離した後、多孔ダイよりストランド状に押し出しして、コールドカット方式にて、ストランドを冷却および切断しペレット化した。 (Synthesis of PS-1)
The conditions shown in Table 1 are formed by connecting the first reactor, which is a complete mixing type stirring tank, the second reactor, and the third reactor, which is a plug-flow type reactor with a static mixer, in series to form a polymerization process. To produce a styrene-based resin. The capacity of each reactor was 39 liters for the first reactor, 39 liters for the second reactor, and 16 liters for the third reactor. A raw material solution was prepared with the raw material composition shown in Table 1, and the raw material solution was continuously supplied to the first reactor at the flow rate shown in Table 1. The polymerization initiator was added to the raw material solution at the inlet of the first reactor so as to have the addition concentration (concentration based on the mass with respect to the raw material styrene) shown in Table 1, and uniformly mixed. The polymerization initiators listed in Table 1 are as follows.
Polymerization Initiator-1: 2,2-di (4,5-t-butylperoxycyclohexyl) propane (Pertetra A manufactured by NOF CORPORATION was used)
Polymerization Initiator-2: 1,1-di (t-Butyl Peroxy) Cyclohexane (Perhexa C manufactured by NOF CORPORATION was used)
In the third reactor, a temperature gradient was applied along the flow direction, and the temperature was adjusted to the temperature shown in Table 1 at the intermediate portion and the outlet portion.
Subsequently, a solution containing the polymer continuously taken out from the third reactor was introduced into a vacuum devolatilization tank with a preheater composed of two stages in series, and the preheater was adjusted to the resin temperature shown in Table 1. After separating unreacted styrene and ethylbenzene by adjusting the temperature of the above to the pressure shown in Table 1, the strands are extruded into strands from a porous die, and the strands are cooled and cut by a cold cut method. It was pelletized.
完全混合型撹拌槽である第１反応器と第２反応器及び静的混合器付プラグフロー型反応器である第３反応器を直列に接続して重合工程を構成し、表１に示す条件によりスチレン系樹脂の製造を実施した。各反応器の容量は、第１反応器を３９リットル、第２反応器を３９リットル、第３反応器を１６リットルとした。表１に記載の原料組成にて、原料溶液を作成し、第１反応器に原料溶液を表１に記載の流量にて連続的に供給した。重合開始剤は、第１反応器の入口で表１に記載の添加濃度（原料スチレンに対する質量基準の濃度）となるように原料溶液に添加し、均一混合した。表１に記載の重合開始剤は次の通りである。
重合開始剤－１ ：２，２－ジ（４，４－ｔ－ブチルパーオキシシクロヘキシル）プロパン（日油株式会社製パーテトラＡを使用した。）
重合開始剤－２ ：１，１－ジ（ｔ－ブチルパーオキシ）シクロヘキサン（日油株式会社製パーヘキサＣを使用した。）
なお、第３反応器では、流れの方向に沿って温度勾配をつけ、中間部分、出口部分で表１の温度となるよう調整した。
続いて、第３反応器より連続的に取り出した重合体を含む溶液を直列に２段より構成される予熱器付き真空脱揮槽に導入し、表１に記載の樹脂温度となるよう予熱器の温度を調整し、表１に記載の圧力に調整することで、未反応スチレン及びエチルベンゼンを分離した後、多孔ダイよりストランド状に押し出しして、コールドカット方式にて、ストランドを冷却および切断しペレット化した。 (Synthesis of PS-1)
The conditions shown in Table 1 are formed by connecting the first reactor, which is a complete mixing type stirring tank, the second reactor, and the third reactor, which is a plug-flow type reactor with a static mixer, in series to form a polymerization process. To produce a styrene-based resin. The capacity of each reactor was 39 liters for the first reactor, 39 liters for the second reactor, and 16 liters for the third reactor. A raw material solution was prepared with the raw material composition shown in Table 1, and the raw material solution was continuously supplied to the first reactor at the flow rate shown in Table 1. The polymerization initiator was added to the raw material solution at the inlet of the first reactor so as to have the addition concentration (concentration based on the mass with respect to the raw material styrene) shown in Table 1, and uniformly mixed. The polymerization initiators listed in Table 1 are as follows.
Polymerization Initiator-1: 2,2-di (4,5-t-butylperoxycyclohexyl) propane (Pertetra A manufactured by NOF CORPORATION was used)
Polymerization Initiator-2: 1,1-di (t-Butyl Peroxy) Cyclohexane (Perhexa C manufactured by NOF CORPORATION was used)
In the third reactor, a temperature gradient was applied along the flow direction, and the temperature was adjusted to the temperature shown in Table 1 at the intermediate portion and the outlet portion.
Subsequently, a solution containing the polymer continuously taken out from the third reactor was introduced into a vacuum devolatilization tank with a preheater composed of two stages in series, and the preheater was adjusted to the resin temperature shown in Table 1. After separating unreacted styrene and ethylbenzene by adjusting the temperature of the above to the pressure shown in Table 1, the strands are extruded into strands from a porous die, and the strands are cooled and cut by a cold cut method. It was pelletized.
ＰＳ－２～ＰＳ－５についても、表１に従い条件を変更した以外は、ＰＳ－１と同様に合成した。
PS-2 to PS-5 were also synthesized in the same manner as PS-1 except that the conditions were changed according to Table 1.
４．実施例・比較例
以下に示す方法で、実施例・比較例を実施した。 4. Examples / Comparative Examples Examples / Comparative Examples were carried out by the methods shown below.
以下に示す方法で、実施例・比較例を実施した。 4. Examples / Comparative Examples Examples / Comparative Examples were carried out by the methods shown below.
＜実施例１＞
表１に示す量のｔ－ブチルカテコール（ＴＢＣ）を含有するスチレン系樹脂（ＰＳ－１）１００質量部に対し、リン系酸化防止剤（ＨＰ－１０）０．２質量部と、リン・フェノール系酸化防止剤（ＧＰ）０．１質量部と、光拡散剤（ＭＢＸ－８）１．０質量部をブレンダーで混合し、スクリュー径４０ｍｍの単軸押出機を用いて、シリンダー温度２３０℃、スクリュー回転数１００ｒｐｍで混合し、スチレン系樹脂組成物を得た。 <Example 1>
0.2 parts by mass of phosphorus-based antioxidant (HP-10) and phosphorus-phenol with respect to 100 parts by mass of styrene resin (PS-1) containing t-butylcatechol (TBC) in the amount shown in Table 1. 0.1 part by mass of the system antioxidant (GP) and 1.0 part by mass of the light diffusing agent (MBX-8) are mixed with a blender, and using a single shaft extruder with a screw diameter of 40 mm, the cylinder temperature is 230 ° C. Mixing was performed at a screw rotation speed of 100 rpm to obtain a styrene resin composition.
表１に示す量のｔ－ブチルカテコール（ＴＢＣ）を含有するスチレン系樹脂（ＰＳ－１）１００質量部に対し、リン系酸化防止剤（ＨＰ－１０）０．２質量部と、リン・フェノール系酸化防止剤（ＧＰ）０．１質量部と、光拡散剤（ＭＢＸ－８）１．０質量部をブレンダーで混合し、スクリュー径４０ｍｍの単軸押出機を用いて、シリンダー温度２３０℃、スクリュー回転数１００ｒｐｍで混合し、スチレン系樹脂組成物を得た。 <Example 1>
0.2 parts by mass of phosphorus-based antioxidant (HP-10) and phosphorus-phenol with respect to 100 parts by mass of styrene resin (PS-1) containing t-butylcatechol (TBC) in the amount shown in Table 1. 0.1 part by mass of the system antioxidant (GP) and 1.0 part by mass of the light diffusing agent (MBX-8) are mixed with a blender, and using a single shaft extruder with a screw diameter of 40 mm, the cylinder temperature is 230 ° C. Mixing was performed at a screw rotation speed of 100 rpm to obtain a styrene resin composition.
続いて、当該スチレン系樹脂組成物を、スクリュー径９０ｍｍ、Ｌ／Ｄ＝３２の単軸ベント付き押出機に供給し、２００～２３５℃で溶融混練した後、リップ幅１０００ｍｍ、リップ開度３．０ｍｍのＴダイにて、Ｔダイ温度２４５～２５０℃で吐出し、縦型３本冷却ロールで冷却固化後、端面をトリミングし、幅８００ｍｍ、厚み２．０ｍｍの光拡散板を得た。光拡散板について初期の光学特性を各測定方法に基づき測定し、また初期の強度についても測定した。次に、上記耐久試験を行い、その後の光学特性を各測定方法に基づき測定を行った。これらの結果について表２に示す。
Subsequently, the styrene-based resin composition was supplied to an extruder with a single-screw vent having a screw diameter of 90 mm and L / D = 32, melt-kneaded at 200 to 235 ° C., and then melt-kneaded. A light diffusing plate having a width of 800 mm and a thickness of 2.0 mm was obtained by discharging with a 0 mm T-die at a T-die temperature of 245 to 250 ° C., cooling and solidifying with three vertical cooling rolls, and trimming the end face. The initial optical characteristics of the light diffusing plate were measured based on each measuring method, and the initial intensity was also measured. Next, the above durability test was performed, and the subsequent optical characteristics were measured based on each measuring method. These results are shown in Table 2.
＜実施例２～１５・比較例１～７＞
実施例２～１５及び比較例１～７についても、表２及び表３に記載の条件に従い変更した以外は、実施例１と同様に樹脂組成物・光拡散板を得て、測定を行った。その結果は、表２及び表３に示す。 <Examples 2 to 15 and Comparative Examples 1 to 7>
Examples 2 to 15 and Comparative Examples 1 to 7 were also measured by obtaining a resin composition / light diffusing plate in the same manner as in Example 1 except that the conditions were changed according to the conditions shown in Tables 2 and 3. .. The results are shown in Tables 2 and 3.
実施例２～１５及び比較例１～７についても、表２及び表３に記載の条件に従い変更した以外は、実施例１と同様に樹脂組成物・光拡散板を得て、測定を行った。その結果は、表２及び表３に示す。 <Examples 2 to 15 and Comparative Examples 1 to 7>
Examples 2 to 15 and Comparative Examples 1 to 7 were also measured by obtaining a resin composition / light diffusing plate in the same manner as in Example 1 except that the conditions were changed according to the conditions shown in Tables 2 and 3. .. The results are shown in Tables 2 and 3.
表中の各略号は下記の通りである。
ＨＰ－１０：２，２'－メチレンビス（４，６－ジ－ｔｅｒｔ－ブチル－１－フェニルオキシ）（２－エチルヘキシルオキシ）ホスホラス（ＡＤＥＫＡ社製；ＨＰ－１０）
１６８：トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）フォスファイト（ＢＡＳＦジャパン社製；Ｉｒｇａｆｏｓ１６８）
ＰＥＰ－３６：３，９－ビス（２，６－ジ－ｔｅｒｔ－ブチル－４－メチルフェノキシ）－２，４，８，１０－テトラオキサ－３，９－ジホスファスピロ〔５．５〕ウンデカン（ＡＤＥＫＡ社製；ＰＥＰ－３６）
Ｐ－ＥＰＱ：テトラキス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）［１，１ビフェニル］－４，４'ジイルビスホスホナイト（ＢＡＳＦジャパン社製；ＩｒｇａｆｏｓＰ－ＥＰＱ）
３８：ビス（２，４－ジ－ｔｅｒｔ－ブチル－６－メチルフェニル）エチル亜リン酸エステル（ＢＡＳＦジャパン社製；Ｉｒｇａｆｏｓ３８）
ＧＰ：６－〔３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ〕－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ〔ｄ，ｆ〕〔１，３，２〕ジオキサホスフェピン（住友化学社製；スミライザーＧＰ）
１０７６：オクタデシル－３－（３，５－ジ－ｔ－ブチル－４－ヒドロキシフェニル）プロピオネート（ＢＡＳＦジャパン社製；Ｉｒｇａｎｏｘ１０７６）
２４５：エチレンビス（オキシエチレン）ビス〔３－（５－ｔｅｒｔ－ブチル－４－ヒドロキシ－ｍ－トリル）プロピオネート〕（ＢＡＳＦジャパン社製；Ｉｒｇａｎｏｘ２４５）
１０１０：ペンタエリスリトールテトラキス［３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート］ （ＢＡＳＦジャパン社製；Ｉｒｇａｎｏｘ１０１０）
ＡＯ８０：３，９－ビス［２－〔３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロピオニルオキシ〕－１，１－ジメチルエチル］－２，４，８，１０－テトラオキサスピロ［５．５］ウンデカン（ＡＤＥＫＡ社製；ＡＯ－８０）
ＭＢＸ－８：アクリル系架橋粒子（平均粒子径８μｍ、積水化成品工業社製；ＭＢＸ－８）
ＳＢＸ－８：ポリスチレン系架橋粒子（平均粒子径８μｍ、積水化成品工業社製；ＳＢＸ－８）
ＫＭＰ－５９０：シリコーン系架橋粒子（平均粒子径２μｍ、信越化学工業社製；ＫＭＰ－５９０） Each abbreviation in the table is as follows.
HP-10: 2,2'-Methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) Phosphorus (manufactured by ADEKA; HP-10)
168: Tris (2,4-di-tert-butylphenyl) phosphite (manufactured by BASF Japan; Irgafos168)
PEP-36: 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] Undecane (ADEKA) Made; PEP-36)
P-EPQ: Tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite (manufactured by BASF Japan; IrgafosP-EPQ)
38: Bis (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite ester (manufactured by BASF Japan; Irgafos38)
GP: 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3 2] Dioxaphosfepine (manufactured by Sumitomo Chemical Co., Ltd .; Sumilyzer GP)
1076: Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by BASF Japan, Inc .; Irganox 1076)
245: Ethylene bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate] (manufactured by BASF Japan, Inc .; Irganox 245)
1010: Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF Japan, Inc .; Irganox 1010)
AO80: 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetra Oxaspiro [5.5] undecane (manufactured by ADEKA; AO-80)
MBX-8: Acrylic crosslinked particles (average particle size 8 μm, manufactured by Sekisui Plastics Co., Ltd .; MBX-8)
SBX-8: Polystyrene-based crosslinked particles (average particle size 8 μm, manufactured by Sekisui Plastics Co., Ltd .; SBX-8)
KMP-590: Silicone-based crosslinked particles (average particle size 2 μm, manufactured by Shin-Etsu Chemical Co., Ltd .; KMP-590)
ＨＰ－１０：２，２'－メチレンビス（４，６－ジ－ｔｅｒｔ－ブチル－１－フェニルオキシ）（２－エチルヘキシルオキシ）ホスホラス（ＡＤＥＫＡ社製；ＨＰ－１０）
１６８：トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）フォスファイト（ＢＡＳＦジャパン社製；Ｉｒｇａｆｏｓ１６８）
ＰＥＰ－３６：３，９－ビス（２，６－ジ－ｔｅｒｔ－ブチル－４－メチルフェノキシ）－２，４，８，１０－テトラオキサ－３，９－ジホスファスピロ〔５．５〕ウンデカン（ＡＤＥＫＡ社製；ＰＥＰ－３６）
Ｐ－ＥＰＱ：テトラキス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）［１，１ビフェニル］－４，４'ジイルビスホスホナイト（ＢＡＳＦジャパン社製；ＩｒｇａｆｏｓＰ－ＥＰＱ）
３８：ビス（２，４－ジ－ｔｅｒｔ－ブチル－６－メチルフェニル）エチル亜リン酸エステル（ＢＡＳＦジャパン社製；Ｉｒｇａｆｏｓ３８）
ＧＰ：６－〔３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ〕－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ〔ｄ，ｆ〕〔１，３，２〕ジオキサホスフェピン（住友化学社製；スミライザーＧＰ）
１０７６：オクタデシル－３－（３，５－ジ－ｔ－ブチル－４－ヒドロキシフェニル）プロピオネート（ＢＡＳＦジャパン社製；Ｉｒｇａｎｏｘ１０７６）
２４５：エチレンビス（オキシエチレン）ビス〔３－（５－ｔｅｒｔ－ブチル－４－ヒドロキシ－ｍ－トリル）プロピオネート〕（ＢＡＳＦジャパン社製；Ｉｒｇａｎｏｘ２４５）
１０１０：ペンタエリスリトールテトラキス［３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート］ （ＢＡＳＦジャパン社製；Ｉｒｇａｎｏｘ１０１０）
ＡＯ８０：３，９－ビス［２－〔３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロピオニルオキシ〕－１，１－ジメチルエチル］－２，４，８，１０－テトラオキサスピロ［５．５］ウンデカン（ＡＤＥＫＡ社製；ＡＯ－８０）
ＭＢＸ－８：アクリル系架橋粒子（平均粒子径８μｍ、積水化成品工業社製；ＭＢＸ－８）
ＳＢＸ－８：ポリスチレン系架橋粒子（平均粒子径８μｍ、積水化成品工業社製；ＳＢＸ－８）
ＫＭＰ－５９０：シリコーン系架橋粒子（平均粒子径２μｍ、信越化学工業社製；ＫＭＰ－５９０） Each abbreviation in the table is as follows.
HP-10: 2,2'-Methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) Phosphorus (manufactured by ADEKA; HP-10)
168: Tris (2,4-di-tert-butylphenyl) phosphite (manufactured by BASF Japan; Irgafos168)
PEP-36: 3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] Undecane (ADEKA) Made; PEP-36)
P-EPQ: Tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite (manufactured by BASF Japan; IrgafosP-EPQ)
38: Bis (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite ester (manufactured by BASF Japan; Irgafos38)
GP: 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3 2] Dioxaphosfepine (manufactured by Sumitomo Chemical Co., Ltd .; Sumilyzer GP)
1076: Octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (manufactured by BASF Japan, Inc .; Irganox 1076)
245: Ethylene bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate] (manufactured by BASF Japan, Inc .; Irganox 245)
1010: Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (manufactured by BASF Japan, Inc .; Irganox 1010)
AO80: 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetra Oxaspiro [5.5] undecane (manufactured by ADEKA; AO-80)
MBX-8: Acrylic crosslinked particles (average particle size 8 μm, manufactured by Sekisui Plastics Co., Ltd .; MBX-8)
SBX-8: Polystyrene-based crosslinked particles (average particle size 8 μm, manufactured by Sekisui Plastics Co., Ltd .; SBX-8)
KMP-590: Silicone-based crosslinked particles (average particle size 2 μm, manufactured by Shin-Etsu Chemical Co., Ltd .; KMP-590)
Claims (8)
- スチレン系樹脂組成物を含む光拡散板であって、
前記スチレン系樹脂組成物が、スチレン系樹脂（Ａ）と、酸化防止剤（Ｂ）と、光拡散剤（Ｃ）と、を含有し、
前記酸化防止剤（Ｂ）は、リン系酸化防止剤（Ｂ－１）、フェノール系酸化防止剤（Ｂ－２）、及びリン・フェノール系酸化防止剤（Ｂ－３）のうち少なくとも１種を含み、
前記スチレン系樹脂１００質量部に対して、
前記リン系酸化防止剤（Ｂ－１）と前記リン・フェノール系酸化防止剤（Ｂ－３）を合計で０．００１～０．５質量部、
前記フェノール系酸化防止剤（Ｂ－２）と前記リン・フェノール系酸化防止剤（Ｂ－３）を合計で０．００１～０．５質量部、
前記光拡散剤（Ｃ）を０．１～１０質量部、
含有し、
前記スチレン系樹脂組成物に含まれるｔ－ブチルカテコールの含有量が０．１～１０μｇ／ｇである、光拡散板。 A light diffusing plate containing a styrene resin composition.
The styrene-based resin composition contains a styrene-based resin (A), an antioxidant (B), and a light diffusing agent (C).
The antioxidant (B) is at least one of a phosphorus-based antioxidant (B-1), a phenol-based antioxidant (B-2), and a phosphorus-phenol-based antioxidant (B-3). Including
With respect to 100 parts by mass of the styrene resin
A total of 0.001 to 0.5 parts by mass of the phosphorus-based antioxidant (B-1) and the phosphorus-phenolic antioxidant (B-3).
A total of 0.001 to 0.5 parts by mass of the phenolic antioxidant (B-2) and the phosphorus / phenolic antioxidant (B-3).
0.1 to 10 parts by mass of the light diffusing agent (C),
Contains,
A light diffusing plate having a content of t-butylcatechol contained in the styrene resin composition of 0.1 to 10 μg / g. - 前記リン系酸化防止剤（Ｂ－１）が、
２，２'－メチレンビス（４，６－ジ－ｔｅｒｔ－ブチル－１－フェニルオキシ）（２－エチルヘキシルオキシ）ホスホラス、
トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）フォスファイト、
３，９－ビス（２，６－ジ―ｔｅｒｔ－ブチル―４－メチルフェノキシ）－２，４，８，１０－テトラオキサ―３，９－ジホスファスピロ〔５，５〕ウンデカン、
テトラキス（２，４－ジ―ｔｅｒｔ－ブチルフェニル）〔１，１ビフェニル〕―４，４'ジイルビスホスホナイト、
ビス（２，４－ジ―ｔｅｒｔ－ブチル―６－メチルフェニル）エチル亜リン酸エステルから選ばれる少なくとも１種である、請求項１に記載の光拡散板。 The phosphorus-based antioxidant (B-1)
2,2'-Methylenebis (4,6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus,
Tris (2,4-di-tert-butylphenyl) phosphite,
3,9-bis (2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro [5,5] undecane,
Tetrakis (2,4-di-tert-butylphenyl) [1,1 biphenyl] -4,4'diylbisphosphonite,
The light diffusing plate according to claim 1, which is at least one selected from bis (2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite ester. - 前記フェノール系酸化防止剤（Ｂ－２）が、
６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピン、
オクタデシル－３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート、
エチレンビス（オキシエチレン）ビス〔３－（５－ｔｅｒｔ－ブチル－４－ヒドロキシ－ｍ－トリル）プロピオネート〕、
ペンタエリスリトールテトラキス［３－（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシフェニル）プロピオネート］、
３，９－ビス［２－〔３－（３－ｔｅｒｔ－ブチル―４－ヒドロキシ―５－メチルフェニル）プロピオニルオキシ〕－１，１－ジメチルエチル］－２，４，８，１０－テトラオキサスピロ［５，５］ウンデカンから選ばれる少なくとも１種である、請求項１又は請求項２に記載の光拡散板。 The phenolic antioxidant (B-2)
6- [3- (3-tert-Butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert-butyldibenzo [d, f] [1,3,2] Dioxaphosfepine,
Octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate,
Ethylene bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate],
Pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate],
3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5, 5] The light diffusing plate according to claim 1 or 2, which is at least one selected from undecane. - 前記リン・フェノール系酸化防止剤（Ｂ－３）が、６－［３－（３－ｔｅｒｔ－ブチル－４－ヒドロキシ－５－メチルフェニル）プロポキシ］－２，４，８，１０－テトラ－ｔｅｒｔ－ブチルジベンゾ［ｄ，ｆ］［１，３，２］ジオキサホスフェピンである、請求項１～請求項３のいずれか１項に記載の光拡散板。 The phosphorus-phenolic antioxidant (B-3) is 6- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propoxy] -2,4,8,10-tetra-tert. The light diffusing plate according to any one of claims 1 to 3, which is butyldibenzo [d, f] [1,3,2] dioxaphosphepine.
- 前記光拡散剤（Ｃ）が、アクリル系重合体架橋粒子、スチレン系重合体架橋粒子、シロキサン系重合体架橋粒子から選ばれる少なくとも１種である、請求項１～請求項４のいずれか１項に記載の光拡散板。 Any one of claims 1 to 4, wherein the light diffusing agent (C) is at least one selected from acrylic polymer crosslinked particles, styrene polymer crosslinked particles, and siloxane polymer crosslinked particles. The light diffusing plate described in.
- 前記スチレン系樹脂（Ａ）の重量平均分子量（Ｍｗ）が２０万～４０万で、重量平均分子量（Ｍｗ）と数平均分子量（Ｍｎ）の比（Ｍｗ／Ｍｎ）が１．０～３．０である、請求項１～請求項５のいずれか１項に記載の光拡散板。 The weight average molecular weight (Mw) of the styrene resin (A) is 200,000 to 400,000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.0 to 3.0. The light diffusing plate according to any one of claims 1 to 5.
- ＬＥＤ光源用である請求項１～請求項６のいずれか１項に記載の光拡散板。 The light diffusing plate according to any one of claims 1 to 6, which is for an LED light source.
- 請求項１～請求項７のいずれか１項に記載の光拡散板を有する、直下型面光源ユニット。 A direct type surface light source unit having the light diffusing plate according to any one of claims 1 to 7.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020227025179A KR20220118526A (en) | 2019-12-24 | 2020-12-17 | Light diffuser plate and direct surface light source unit |
| JP2021567354A JPWO2021132001A1 (en) | 2019-12-24 | 2020-12-17 | |
| MX2022005316A MX2022005316A (en) | 2019-12-24 | 2020-12-17 | Light diffusion plate and direct surface light source unit. |
| CN202080077557.9A CN114730022A (en) | 2019-12-24 | 2020-12-17 | Light diffusion plate and direct type surface light source unit |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019232946 | 2019-12-24 | ||
| JP2019-232946 | 2019-12-24 |
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| WO2021132001A1 true WO2021132001A1 (en) | 2021-07-01 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2020/047109 WO2021132001A1 (en) | 2019-12-24 | 2020-12-17 | Light diffusion plate and direct surface light source unit |
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| Country | Link |
|---|---|
| JP (1) | JPWO2021132001A1 (en) |
| KR (1) | KR20220118526A (en) |
| CN (1) | CN114730022A (en) |
| MX (1) | MX2022005316A (en) |
| TW (1) | TW202132822A (en) |
| WO (1) | WO2021132001A1 (en) |
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| JP2006299192A (en) * | 2005-04-25 | 2006-11-02 | Asahi Kasei Chemicals Corp | Styrene-based resin composition containing silicone-based particle |
| JP2006299191A (en) * | 2005-04-25 | 2006-11-02 | Asahi Kasei Chemicals Corp | Styrene-based resin composition containing acrylic resin particle |
| JP2009215476A (en) * | 2008-03-12 | 2009-09-24 | Toyo Styrene Co Ltd | Styrenic resin composition for light diffusing plate and process for producing the same |
| WO2010071152A1 (en) * | 2008-12-17 | 2010-06-24 | 電気化学工業株式会社 | Molded object for optical use, and lightguide plate and light diffuser both comprising same |
| WO2016129675A1 (en) * | 2015-02-12 | 2016-08-18 | デンカ株式会社 | Styrene-based optical resin composition |
| WO2017094748A1 (en) * | 2015-11-30 | 2017-06-08 | デンカ株式会社 | Transparent highly heat-resistant styrene copolymer |
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|---|---|---|---|---|
| JP4890766B2 (en) * | 2005-01-28 | 2012-03-07 | 帝人化成株式会社 | Light diffusing aromatic polycarbonate resin composition |
| JP4837981B2 (en) * | 2005-11-18 | 2011-12-14 | 住化スタイロンポリカーボネート株式会社 | Thermoplastic resin composition having excellent light diffusibility and light diffusing plate comprising the same |
| KR20100028057A (en) * | 2007-06-28 | 2010-03-11 | 스미토모 다우 가부시키가이샤 | Light diffusing thermoplastic resin composition and light diffusion sheet thereof |
| KR101045558B1 (en) * | 2007-09-11 | 2011-07-01 | 디아이씨 가부시끼가이샤 | Resin composition for light-diffusion plate, light-diffusion plate, and its manufacturing method |
| WO2010053204A1 (en) | 2008-11-06 | 2010-05-14 | 住友化学株式会社 | Light diffuser plate and use thereof |
| KR101981561B1 (en) * | 2015-03-26 | 2019-05-23 | 스미카 폴리카르보네이트 가부시키가이샤 | Polycarbonate resin composition and optical molded article |
-
2020
- 2020-12-17 TW TW109144598A patent/TW202132822A/en unknown
- 2020-12-17 MX MX2022005316A patent/MX2022005316A/en unknown
- 2020-12-17 KR KR1020227025179A patent/KR20220118526A/en unknown
- 2020-12-17 WO PCT/JP2020/047109 patent/WO2021132001A1/en active Application Filing
- 2020-12-17 JP JP2021567354A patent/JPWO2021132001A1/ja active Pending
- 2020-12-17 CN CN202080077557.9A patent/CN114730022A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006299192A (en) * | 2005-04-25 | 2006-11-02 | Asahi Kasei Chemicals Corp | Styrene-based resin composition containing silicone-based particle |
| JP2006299191A (en) * | 2005-04-25 | 2006-11-02 | Asahi Kasei Chemicals Corp | Styrene-based resin composition containing acrylic resin particle |
| JP2009215476A (en) * | 2008-03-12 | 2009-09-24 | Toyo Styrene Co Ltd | Styrenic resin composition for light diffusing plate and process for producing the same |
| WO2010071152A1 (en) * | 2008-12-17 | 2010-06-24 | 電気化学工業株式会社 | Molded object for optical use, and lightguide plate and light diffuser both comprising same |
| WO2016129675A1 (en) * | 2015-02-12 | 2016-08-18 | デンカ株式会社 | Styrene-based optical resin composition |
| WO2017094748A1 (en) * | 2015-11-30 | 2017-06-08 | デンカ株式会社 | Transparent highly heat-resistant styrene copolymer |
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| Publication number | Publication date |
|---|---|
| MX2022005316A (en) | 2022-05-26 |
| CN114730022A (en) | 2022-07-08 |
| TW202132822A (en) | 2021-09-01 |
| KR20220118526A (en) | 2022-08-25 |
| JPWO2021132001A1 (en) | 2021-07-01 |
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