WO2023218994A1 - Composition de résine à base de styrène à usage optique, plaque de guidage de lumière, unité de source de lumière de surface de type à émission latérale, plaque de diffusion de lumière, et unité de source de lumière de surface de type directement sous-jacent - Google Patents

Composition de résine à base de styrène à usage optique, plaque de guidage de lumière, unité de source de lumière de surface de type à émission latérale, plaque de diffusion de lumière, et unité de source de lumière de surface de type directement sous-jacent Download PDF

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WO2023218994A1
WO2023218994A1 PCT/JP2023/016702 JP2023016702W WO2023218994A1 WO 2023218994 A1 WO2023218994 A1 WO 2023218994A1 JP 2023016702 W JP2023016702 W JP 2023016702W WO 2023218994 A1 WO2023218994 A1 WO 2023218994A1
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resin composition
light
bis
styrenic resin
mass
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PCT/JP2023/016702
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English (en)
Japanese (ja)
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泰生 山口
亘 渡辺
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デンカ株式会社
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Publication of WO2023218994A1 publication Critical patent/WO2023218994A1/fr

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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
    • C08K5/16—Nitrogen-containing compounds
    • C08K5/34—Heterocyclic compounds having nitrogen in the ring
    • C08K5/3412—Heterocyclic compounds having nitrogen in the ring having one nitrogen atom in the ring
    • C08K5/3432—Six-membered rings
    • C08K5/3435—Piperidines
    • 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
    • C08L25/08—Copolymers of styrene
    • C08L25/14—Copolymers of styrene with unsaturated esters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F21V3/04—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings
    • F21V3/06—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings characterised by the material
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2105/00—Planar light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2105/00—Planar light sources
    • F21Y2105/10—Planar light sources comprising a two-dimensional array of point-like light-generating elements
    • F21Y2105/14—Planar light sources comprising a two-dimensional array of point-like light-generating elements characterised by the overall shape of the two-dimensional array
    • F21Y2105/16—Planar light sources comprising a two-dimensional array of point-like light-generating elements characterised by the overall shape of the two-dimensional array square or rectangular, e.g. for light panels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]

Definitions

  • the present invention relates to an optical styrene resin composition, a light guide plate, an edge-light type surface light source unit, a light diffusion plate, and a direct type surface light source unit.
  • backlights for liquid crystal display devices: a direct type in which the light source is placed in front of the display device, and an edge light type in which the light source is placed on the side.
  • Edge-lit backlights use a component called a light guide plate that guides light from a light source placed on the side to the front of the display device. It is used in a wide range of applications, including televisions, desktop personal computer monitors, notebook personal computers, mobile phones, and car navigation monitors. Furthermore, backlights using light guide plates are also used as lighting devices, signboards, and the like.
  • the light guide plate is required to have a particularly high light transmittance because the light transmission distance is relatively long and the light loss due to the optical path length is large.
  • the material used for the light guide plate is an acrylic resin such as polymethyl methacrylate (PMMA).
  • PMMA polymethyl methacrylate
  • the light guide plate may warp or change dimensions due to water absorption.
  • Patent Document 1 proposes using a styrene-methyl (meth)acrylate copolymer as a material for a light guide plate.
  • Patent Document 2 has been proposed as a technology for improving the hue of styrene-methyl (meth)acrylate.
  • the present invention was made in view of these problems, and provides an optical styrenic resin composition that has excellent transparency, hue, and dimensional stability, and also has excellent light stability for long-term use of LED light sources. It is something to do.
  • an optical material containing a styrenic resin (A) which is a copolymer containing a styrene monomer unit and a (meth)acrylic acid ester monomer unit and a hindered amine light stabilizer (B)
  • a styrenic resin composition wherein the copolymer contains 95 to 20% by mass of the styrene monomer unit and the (meth)acrylic acid ester monomer unit in 100% by mass of the copolymer.
  • a composition is provided.
  • the present inventors conducted extensive studies and found that styrenic resins in which the content of styrene monomer units and (meth)acrylic acid ester monomer units are within a specific range, and It was discovered that an optical styrenic resin composition containing a hindered amine light stabilizer simultaneously satisfies transparency, hue, dimensional stability, and light stability for long-term use of LED light sources, leading to the completion of the present invention. Ta.
  • A Optical styrenic resin containing styrenic resin
  • B a hindered amine light stabilizer
  • the composition, wherein the copolymer contains 95 to 20 mass % of the styrene monomer units and 5 to 80 mass % of the (meth)acrylate monomer units in 100 mass % of the copolymer.
  • the NH type hindered amine light stabilizer is bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate, 2,2,6,6-tetramethyl-4-piperidylhexadecanoate, 2,2,6,6-tetramethyl-4-piperidyloctadecanoate, tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate, A polycondensate of N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylenediamine and 4-morpholino2,6-dichloro-1,3,5-triazine, 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino) and 1,3,5-triazine/N,N'-bis(2,2,6,6-tetramethyl-4 - polycondensate with piperidyl)hexamethylene diamine,
  • the NR type hindered amine light stabilizer is Methyl (1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate, bis(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate, bis(1,2,2,6,6-pentamethylpiperidin-4-yl)n-butyl 3,5-di-tert-butyl 4-hydroxybenzylmalonate, Polycondensate of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol and dimethyl succinate, 1,5,8,12-tetrakis[4,6-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-1,3,5-triazine- 2-yl]-1,5,8,12-tetraazadodecane, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and ⁇ ,
  • the phosphorus antioxidant (C-1) is tris(2,4-di-tert-butylphenyl) phosphite, 2,2'-methylenebis(4,6-di-tert-butyl-1) -phenyloxy)(2-ethylhexyloxy)phosphorus, bis-(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, 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' -
  • the optical styrenic resin composition according to [5] which is at least one selected from diylbisphosphonite and bis(2,4-di-tert-butyl-6-methylphen
  • a light guide plate formed by molding the optical styrenic resin composition according to any one of [1] to [6].
  • An edge-light surface light source unit comprising the light guide plate according to [7] and a light source that supplies LED light to an end surface of the light guide plate.
  • a light diffusing plate formed by molding the optical styrenic resin composition according to any one of [1] to [6].
  • a direct type surface light source unit comprising the light diffusing plate according to [9] and a light source that supplies LED light to the light diffusing plate.
  • the styrenic resin composition for optics is a styrenic resin composition for optics containing a styrenic resin (A) and a hindered amine light stabilizer (B). be.
  • the styrenic resin (A) is a resin obtained by copolymerizing a monomer containing a styrene monomer and a (meth)acrylic acid ester monomer.
  • the styrenic resin (A) is a copolymer containing a styrene monomer unit and a (meth)acrylic acid ester monomer unit.
  • the copolymer contains 95 to 20 mass % of styrene monomer units and 5 to 80 mass % of (meth)acrylate monomer units in 100 mass % of the copolymer, preferably styrene monomer units.
  • the content of (meth)acrylic acid ester monomer units in the styrene resin (A) is, for example, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35 , 40, 45, 50, 55, 60, 65, 70, 75, 80% by mass, and may be within a range between any two of the numerical values exemplified here.
  • styrenic monomer examples include styrene, ⁇ -methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, ethylstyrene, and pt-butylstyrene. These can be used alone or in combination of two or more.
  • the styrenic monomer is preferably styrene.
  • Examples of (meth)acrylic acid ester monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and n-(meth)acrylate.
  • - (Meth)acrylic acid alkyl esters such as butyl, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, etc.
  • (meth)acrylic acid aryl esters such as phenyl (meth)acrylate and benzyl (meth)acrylate; cyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, 2-(meth)acrylate norbornyl, isobornyl (meth)acrylate, adamantan-1-yl (meth)acrylate, 2-methyladamantan-2-yl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate, (meth)acrylate
  • Examples include cycloalkyl (meth)acrylates such as tricyclodecanyl acrylate; glycidyl (meth)acrylate; dicyclopentanyl (meth)acrylate; and the like. These can be used alone or in combination of two or more.
  • the (meth)acrylic acid ester monomer is preferably an alkyl (meth)acrylate, more
  • the styrene resin (A) may be a copolymer obtained by copolymerizing with a monomer copolymerizable with a styrene monomer and a (meth)acrylic acid ester monomer.
  • copolymerizable monomers include (meth)acrylic acids such as acrylic acid and methacrylic acid; vinyl cyanides such as acrylonitrile and methacrylonitrile; and ⁇ , ⁇ -ethylene monomers such as maleic anhydride and fumaric acid.
  • Saturated carboxylic acids; Imides such as phenylmaleimide and cyclohexylmaleimide can be mentioned. These can be used alone or in combination of two or more.
  • the weight average molecular weight (Mw) of the styrenic resin (A) is preferably 50,000 to 400,000, more preferably 100,000 to 350,000. Further, 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 3.5, more preferably 1.5 to It is 3.0. By setting it within such a range, it is possible to achieve both moldability and strength of the light guide plate. If the weight average molecular weight (Mw) is less than 50,000, the strength of the molded article will be insufficient, and if it exceeds 400,000, moldability may deteriorate. Further, when the ratio of number average molecular weight (Mn) (Mw/Mn) is less than 1.0, moldability is reduced, and when it exceeds 3.5, the strength of the molded article may be reduced.
  • the optical styrenic resin composition contains 0.001 to 1.0 parts by mass of the hindered amine light stabilizer (B), preferably 0.01 to 0.0 parts by mass, per 100 parts by mass of the styrene resin (A). Contains 3 parts by mass. By setting it as such a range, transparency, hue, and light stability with respect to an LED light source can be improved. Specifically, the content of the hindered amine light stabilizer (B) is, for example, 0.001, 0.005, 0.01, 0.02, 0.03, 0.
  • the amount may be 0.8, 0.9, or 1.0 part by mass, and may be within a range between any two of the numerical values exemplified here.
  • the hindered amine light stabilizer (B) may be used alone or in combination of two or more.
  • the hindered amine light stabilizer (B) is a compound having a structural unit represented by the following general formula (1).
  • R is a hydrogen atom, it is an N-H type hindered amine light stabilizer, and when R is a linear or branched alkyl group having 1 to 10 carbon atoms, or a methylene group, it is an N-R type hindered amine.
  • a light stabilizer in which R is an alkoxy group is referred to as an N-OR hindered amine light stabilizer.
  • N-H type hindered amine light stabilizer examples include bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate (TINUVIN770DF manufactured by BASF), 2,2,6,6-tetramethyl -4-piperidylhexadecanoate, 2,2,6,6-tetramethyl-4-piperidyl octadecanoate (SABOSTAB UV91 manufactured by SONGWON), tetrakis (2,2,6,6-tetramethyl-4- piperidyl)-1,2,3,4-butanetetracarboxylate (ADK STAB LA-57 manufactured by ADEKA), N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexa Polycondensate of methylene diamine and 4-morpholino 2,6-dichloro-1,3,5-triazine (SABOSTAB UV79 manufactured by SONGWON), 2,4-dichloro-6-(1,1,3,3-te
  • Henicosan-20-yl)propionate tetradecyl 3-(2,2,4,4-tetramethyl-21-oxo-7-oxa-3,20-diazadispiro(5.1.11.2)henicosan -20-yl) propionate (manufactured by CLARIANT HOSTAVIN3030), 2,2,4,4-tetramethyl-7-oxa-3,20-diazadispiro-(5.1.11.2) henicosan-21-one and epi Examples include polycondensates with chlorohydrin (HOSTAVIN N30P manufactured by CLARIANT).
  • NR type hindered amine light stabilizers include methyl (1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate, bis(1,2,2,6,6-pentamethyl piperidin-4-yl) sebacate (manufactured by BASF, TINUVIN292, TINUVIN765), bis(1,2,2,6,6-pentamethylpiperidin-4-yl)n-butyl 3,5-di-tert-butyl 4- Hydroxybenzyl malonate (TINUVIN144 manufactured by BASF), polycondensate of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol and dimethyl succinate (TINUVIN622SF manufactured by BASF), 1,5 ,8,12-tetrakis[4,6-bis(N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino)-1,3,5-triazin-2-yl ]-1,5,8,12-tetraazad
  • N-OR type hindered amine light stabilizers include bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate (TINUVIN123 manufactured by BASF), bis(1-undecanoxy-2,2 , 6,6-tetramethylpiperidin-4-yl) carbonate (ADKSTAB LA-81 manufactured by ADEKA).
  • the hindered amine light stabilizer (B) is preferred as the NH type hindered amine light stabilizer and/or the NR type hindered amine light stabilizer in that it has little influence on the transparency and hue of the optical styrenic resin composition.
  • a light stabilizer is preferable, and an NR type hindered amine light stabilizer is more preferable.
  • the hindered amine light stabilizer (B) is generally oxidized by oxygen, ultraviolet light, and peroxide to generate nitroxy radicals.
  • the mechanism by which the hindered amine light stabilizer (B) can improve the photostability of LED light sources for long-term use is still being elucidated, the effectiveness of the hindered amine light stabilizer (B) has been discovered by the present invention. It is something that
  • the optical styrenic resin composition preferably contains 0.001 to 0.5 parts by mass of the phosphorus antioxidant (C-1), more preferably, based on 100 parts by mass of the styrenic resin (A). is 0.002 to 0.4 parts by weight, particularly preferably 0.005 to 0.3 parts by weight. By setting it as such a range, transparency and hue can be improved.
  • the content of the phosphorus antioxidant (C-1) is, for example, 0.001, 0.002, 0.003, 0.004, based on 100 parts by mass of the styrene resin (A). 0.005, 0.01, 0.02, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5 parts by mass, and any two of the numerical values exemplified here. It may be within the range between.
  • the phosphorous antioxidant (C-1) is a ()phosphorous ester that does not have a phenolic hydroxyl group in its basic skeleton, preferably a phosphorous ester that is a trivalent phosphorus compound.
  • Specific examples of the phosphorus antioxidant (C-1) include 2,2'-methylenebis(4,6-di-tert-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, bis-(2 , 4-di-tert-butylphenyl) pentaerythritol diphosphite, 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)
  • the optical styrenic resin composition may contain 0 to 0.5 parts by mass of a phenolic antioxidant (C-2) based on 100 parts by mass of the styrenic resin (A). If the content of the phenolic antioxidant (C-2) exceeds 0.5 parts by mass, the hue deteriorates, which is not preferable.
  • the content of the phenolic antioxidant (C-2) is, for example, 0, 0.001, 0.002, 0.003, 0.000%, based on 100 parts by mass of the styrene resin (A).
  • the phenolic antioxidant (C-2) is an antioxidant that has a phenolic hydroxyl group in its basic skeleton and is not a ()phosphate ester.
  • Specific examples of the phenolic antioxidant (C-2) include 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], and these are one type. These can be used alone or in combination of two or more.
  • Antioxidants include 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenzo[d,f][ 1,3,2]
  • phosphorus-phenol compounds such as dioxaphosphepine that have both a phosphite structure and a phenol structure in the same molecule.
  • the optical styrenic resin composition is considered to contain each of a phosphorus antioxidant and a phenolic antioxidant, and for example, based on 100 parts by mass of the styrenic resin (A), When containing 0.1 part by mass of the phosphorus-phenol compound, it is considered that 0.1 part by mass of the phosphorus antioxidant and 0.1 part by mass of the phenolic antioxidant are contained.
  • the content of t-butylcatechol (TBC) in the optical styrenic resin composition is preferably 10 ppm or less, more preferably 5 ppm or less. By setting it as such a range, a light guide plate with excellent hue and transmittance can be obtained.
  • the content of TBC is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ppm, and may be within the range between any two of the numerical values exemplified here.
  • the content of 6-tert-butyl-2,4-xylenol (TBX) in the optical styrenic resin composition is preferably 10 ppm or less, more preferably 5 ppm or less. By setting it as such a range, a light guide plate with excellent hue and transmittance can be obtained.
  • the content of TBX is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 ppm, and any two of the numerical values exemplified here. It may be within the range between.
  • the optical styrenic resin composition may contain sulfur-based antioxidants, lactone-based antioxidants, ultraviolet absorbers, antistatic agents, hydrophilic additives, liquid paraffin (mineral oil), within a range that does not impair the characteristics of the present invention. ), polyethylene wax, microcrystalline wax, bluing agent, higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, higher fatty acid amides such as stearic acid amide, erucic acid amide, ethylene bisstearic acid amide, lauric acid It may contain a mold release agent such as higher fatty acid glycerides such as monoglyceride, palmitic acid monoglyceride, stearic acid monoglyceride, and behenic acid monoglyceride, higher alcohols such as myristyl alcohol, cetyl alcohol, and stearyl alcohol.
  • a mold release agent such as higher fatty acid glycerides such as monoglyceride, palm
  • the melt mass flow rate (MFR) of the optical styrenic resin composition at a temperature of 200° C. and a load of 49 N is preferably 0.5 to 5.0 g/10 minutes, more preferably 1.0 to It is 4.0g/10 minutes. If the MFR is less than 0.5 g/10 minutes, the molding stability will decrease, and if the MFR exceeds 5.0 g/10 minutes, the strength will be insufficient.
  • the Vicat softening temperature of the optical styrenic resin composition is preferably 95 to 104°C, more preferably 100 to 104°C. If the Vicat softening temperature is less than 95° C., heat resistance will be insufficient, and the light guide plate may be deformed depending on the usage environment.
  • Examples of the polymerization method for the styrene resin (A) include known styrene polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization. In terms of quality and productivity, bulk polymerization and solution polymerization are preferred, and continuous polymerization is preferred.
  • Examples of solvents that can be used include alkylbenzenes such as benzene, toluene, ethylbenzene, and xylene, ketones such as acetone and methyl ethyl ketone, and aliphatic hydrocarbons such as hexane and cyclohexane.
  • polymerization auxiliaries such as a polymerization initiator, chain transfer agent, crosslinking agent, and other polymerization auxiliaries can be used as necessary.
  • the polymerization initiator is preferably a radical polymerization initiator, such as known and commonly used ones such as 1,1-di(t-butylperoxy)cyclohexane, 2,2-di(t-butylperoxy)butane, and 2,2-di(t-butylperoxy)butane.
  • Peroxy ketals such as di(4,4-di-t-butylperoxycyclohexyl)propane, 1,1-di(t-amylperoxy)cyclohexane, cumene hydroperoxide, t-butyl hydroperoxide, etc.
  • Hydroperoxides alkyl peroxides such as t-amylperoxyisononanoate, dialkyl such as t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, di-t-hexyl peroxide, etc.
  • Peroxides peroxy esters such as t-butylperoxyacetate, t-butylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl carbonate, polyether tetrakis (t-butylperoxy) carbonate), 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, and one or more of these can be used in combination.
  • peroxy esters such as t-butylperoxyacetate, t-butylperoxybenzoate, t-butylperoxyisopropyl monocarbonate, t-butylperoxyisopropyl carbonate, polyether tetrakis (t-butylper
  • chain transfer agents examples include aliphatic mercaptans such as n-dodecyl mercaptan and tert-dodecyl mercaptan, aromatic mercaptans, thiocarboxylic acids such as thioglycolic acid and mercaptopropionic acid, ethylene glycol, tetraethylene glycol, neopentyl glycol, and trimethylol.
  • Polyfunctional mercaptans obtained by esterifying the hydroxyl groups of polyhydric alcohols such as propane, pentaerythritol, dipentaerythritol, tripentaerythritol, and sorbitol with thioglycolic acid or mercaptopropionic acid, pentaphenylethane, ⁇ -methylstyrene dimer, and terpinolene.
  • polyhydric alcohols such as propane, pentaerythritol, dipentaerythritol, tripentaerythritol, and sorbitol with thioglycolic acid or mercaptopropionic acid, pentaphenylethane, ⁇ -methylstyrene dimer, and terpinolene.
  • aliphatic mercaptans, aromatic mercaptans, thiocarboxylic acids, and polyfunctional mercaptans are preferred from the viewpoint of easy molecular weight adjustment.
  • the styrenic resin (A) can be produced by a method including a polymerization step, a devolatilization step, and a granulation step.
  • the polymerization reaction is controlled by adjusting the polymerization temperature, etc. so that the target molecular weight, molecular weight distribution, and reaction conversion rate are achieved.
  • the polymerization solution containing the polymer that has exited the polymerization step is transferred to a devolatilization step, where unreacted monomers and 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 exited the devolatilization step is transferred to the granulation step.
  • the molten resin is extruded into strands through a perforated die and processed into pellets using a cold cut method, an air hot cut method, or an underwater hot cut method.
  • the optical styrenic resin composition is produced by adding a hindered amine light stabilizer (B), a phosphorus antioxidant (C-1), and a phenolic antioxidant (C-2) to the styrenic resin (A).
  • a hindered amine light stabilizer (B), phosphorus antioxidant (C-1), and a phenolic antioxidant (C-2) may be added to the raw material solution before polymerization of the styrenic resin (A).
  • the styrenic resin (A) may be mixed in an extruder installed after polymerization and before granulation, or in a static mixing device.
  • pellets after granulating the styrene resin (A), the hindered amine light stabilizer (B), the phosphorus antioxidant (C-1), and the phenolic antioxidant (C-2) are dry blended and melted. It may be manufactured by kneading.
  • a pellet-shaped masterbatch obtained by melt-kneading a hindered amine light stabilizer (B), a phosphorus antioxidant (C-1), and a phenolic antioxidant (C-2) with a small amount of styrene resin in advance. may be prepared, dry-blended the styrenic resin (A) and the masterbatch, and then melt-kneaded and adjusted.
  • the content of t-butylcatechol or 6-tert-butyl-2,4-xylenol in the optical styrene resin composition is determined by adjusting the content at the start of polymerization of the styrenic resin (A) and by devolatilizing it thereafter. It is possible to adjust the content in the process etc.
  • a light guide plate according to one embodiment of the present invention is a molded product formed by molding the optical styrenic resin composition.
  • the light guide plate is a light guide plate that can be used in an edge-light type surface light source unit.
  • the light guide plate may have an uneven shape on the surface of the light guide plate. More specifically, the light guide plate may have a plurality of lenticular and/or prism-shaped protrusions on its surface.
  • the convex portion is preferably provided on at least one surface of the light guide plate, and particularly on one surface that is the front surface (light emitting surface) of the light guide plate. Although it may be provided on other surfaces if necessary, it is more preferable that it is provided only on the front surface (light emitting surface) of the light guide plate.
  • the lenticular-shaped convex portion is an arc-shaped convex portion, and is a protrusion whose cross-sectional edge shape is circular.
  • the prism shape is an arcuate convex portion, and a protrusion whose cross-sectional edge shape is a triangular mountain shape.
  • a plurality of convex portions may be formed in parallel relationship with each other.
  • the convex portion may be integrally formed with the light guide plate.
  • the thickness of the light guide plate is 0.2 to 3.0 mm, preferably 0.3 to 2.5 mm, and more preferably 0.4 to 2.4 mm. Within this range, it is easy to produce a light guide plate with excellent moldability such as excellent extrusion stability and strength when molding an optical styrenic resin composition.
  • the average transmittance of the light guide plate in the wavelength range of 380 to 780 nm at an optical path length of 115 mm is preferably 85% or more, more preferably 86% or more.
  • the YI value of the light guide plate at an optical path length of 115 mm is preferably 6.0 or less, more preferably 4.0 or less.
  • a light guide plate according to an embodiment of the present invention is obtained by molding the optical styrenic resin composition described above, and a known method such as sheet extrusion molding, injection molding, or compression molding is used as the molding method.
  • a known method such as sheet extrusion molding, injection molding, or compression molding is used as the molding method.
  • continuous sheet extrusion molding equipped with a surface shape transfer mold is preferable in terms of productivity and ease of increasing the size of the molded product.
  • Examples of sheet extrusion molding include an extrusion process in which a resin is supplied in a heated molten state to a feed block and continuously extruded from a die to create a sheet; a pressing process in which the resin sheet is sandwiched between a pressure roll and a cooling roll; After the pressing step, there is a continuous sheet extrusion molding method that has a conveyance step of conveying the resin sheet while keeping it in close contact with a cooling roll, and has a transfer mold on the surface of the cooling roll, and by changing the shape of the transfer mold, Any uneven shape can be transferred onto the sheet surface.
  • the light guide plate may have an uneven shape on the front surface (light-emitting surface), and the back surface may be subjected to reflective processing to diffusely reflect light.
  • reflective processing include silk printing, inkjet printing, and methods of applying dot-shaped irregularities by laser irradiation. For printing dot patterns, it is possible to use ink with fine particles that diffuse light. can.
  • Edge-light type surface light source unit is an edge-light type surface light source unit having the above-mentioned light guide plate and a light source that supplies LED light to the end face of the light guide plate. .
  • the edge-light type surface light source unit is suitably used as a surface light source device for a liquid crystal display device.
  • a light diffusing plate according to one embodiment of the present invention is a molded article formed by molding the optical styrenic resin composition.
  • the light diffusing plate is a light diffusing plate that can be used in a direct type surface light source unit.
  • the thickness of the light diffusing plate according to an embodiment of the present invention is, for example, 1 to 3 mm, although it is not limited.
  • An antistatic agent may be applied to the surface of the light diffusion plate. By applying the antistatic agent, the attachment of dust and the like due to static electricity is suppressed after the light diffusion plate is attached to the backlight device, so that it can be used for a long period of time without deterioration in brightness.
  • the light diffusing plate of the present invention may have a fine uneven shape such as embossing on both sides or one side, or may have a lenticular shape or a prism shape on both sides or one side. .
  • the light diffusing plate may contain 0.1 to 1.0 parts by mass of a light diffusing agent based on 100 parts by weight of the optical styrene resin composition.
  • the light diffusing agent can be particles having a refractive index different from that of the optical styrene resin composition and can be used as long as it has the effect of diffusing incident light.
  • styrene polymer particles acrylic Organic particles such as polymer particles and siloxane polymer 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 used.
  • at least one selected from acrylic polymer particles, styrene polymer particles, and siloxane polymer particles is preferable.
  • the light diffusing plate according to one embodiment of the present invention can be manufactured by molding the optical styrene resin composition described above by various methods such as extrusion molding and injection molding, but preferably by extrusion molding. do.
  • extrusion molding is a method in which an optical 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 using a cooling roll unit. It can be raised.
  • a transfer mold is provided on the surface of the cooling roll, and by changing the shape of the transfer mold, an arbitrary uneven shape can be formed.
  • methods such as a coextrusion method, an adhesion method, a thermal adhesion method, a solvent adhesion method, a casting method, and a surface coating method can be employed.
  • a direct type surface light source unit is a direct type surface light source unit that includes the above-mentioned light diffusion plate and a light source that supplies LED light to the light diffusion plate.
  • the direct type surface light source unit is suitably used as a surface light source device for a liquid crystal display device.
  • Example 1 Production of optical styrenic resin composition
  • a first reactor which is a complete mixing type stirring tank
  • a second reactor which is a plug flow type reactor with a static mixer, are connected in series to constitute a polymerization process, and a styrenic resin is produced.
  • the capacity of each reactor was 30 liters for the first reactor and 12 liters for the second reactor.
  • the polymerization rate of the monomer at this time was 70%.
  • a temperature gradient was created along the flow direction, and the temperature was adjusted to 130° C. at the middle portion and 145° C. at the outlet portion.
  • the solution containing the polymer continuously taken out from the second reactor is introduced into a vacuum devolatilization tank with a preheater, which consists of two stages in series, and the temperature of the preheater is adjusted so that the resin temperature is 220°C. was adjusted to separate unreacted styrene and ethylbenzene at a pressure of 0.8 kPa.
  • the obtained molten polymer was continuously fed to the extruder, and 0.1 parts by mass of hindered amine light stabilizer (770) was added to 100 parts by mass of the polymer from the additive feed port, and the settings were made. After mixing at a temperature of 220° C., the mixture was extruded into a strand through a multi-hole die, and the strand was cooled and cut using a cold cut method to form pellets.
  • the TBC concentration in the obtained optical styrenic resin composition was 1.5 ⁇ g/g, and the TBX concentration was 0.2 ⁇ g/g. Further, the weight average molecular weight (Mw) was 170,000, and the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw/Mn) was 2.0.
  • Examples 2 to 17 and Comparative Examples 1 to 6 The composition of the raw material solution and polymerization conditions were changed as shown in Table 1, and a hindered amine light stabilizer (B), a phosphorus antioxidant (C-1), a phenolic antioxidant (C-2), and an ultraviolet absorber were added.
  • An optical styrenic resin composition and a light guide plate were produced in the same manner as in Example 1, except that the formulation of agent (D) was changed as shown in Tables 2 (Tables 2-1 and 2-2) to Table 3.
  • Tables 2 Table 2-1 and Table 2-2
  • the ultraviolet absorbers (D) are as follows.
  • (Hindered amine light stabilizer (B)) 770 Bis(2,2,6,6-tetramethylpiperidin-4-yl)sebacate (BASF TINUVIN770DF) 944: 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino) and 1,3,5-triazine/N,N'-bis(2,2,6,6-tetramethyl Polycondensate of -4-piperidyl)hexamethylenediamine (Chimass®rb944FDL, manufactured by BASF) 292: Methyl (1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate: 25% and bis(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate: 75 % mixture (BASF TINUVIN292) 123: Bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate (BASF TINUVIN123)
  • Phosphorous antioxidant (C-1)) 168 Tris(2,4-di-tert-butylphenyl) phosphite (Irgafos 168 manufactured by BASF) HP-10: 2,2'-methylenebis(4,6-di-tert-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus (ADKSTAB HP-10 manufactured by ADEKA) 126: Bis-(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (Irgafos 126 manufactured by BASF)
  • melt mass flow rate (MFR)> The melt mass flow rate was measured according to JIS K 7210 at a temperature of 200°C and a load of 49N.
  • the Vicat softening temperature was measured according to JIS K 7206 at a heating rate of 50°C/hr and a test load of 50N.
  • ⁇ Content of TBC and TBX in optical styrenic resin composition After dissolving 0.2 g of the optical styrene resin composition in a small amount of THF, 200 ⁇ L of BSTFA (M,O-bis(trimethylsilyl)trifluoroacetamide) was added, trimethylsilyl derivatization treatment was performed, and 10 mL of THF was added. After adjusting the volume, the supernatant liquid was separated by centrifugation, and the supernatant liquid was measured by gas chromatography/mass spectrometry (GC/MS) under the following conditions. Note that a previously prepared calibration curve was used to determine the concentration.
  • BSTFA M,O-bis(trimethylsilyl)trifluoroacetamide
  • GC device Agilent 7890A
  • Column Agilent DB-5ms (0.25mm i.d. x 30m) Liquid phase film thickness 0.25 ⁇ m
  • Inlet 300°C, 1.5mL/min, (split ratio 1:5)
  • MS device Agilent 5975C Interface temperature: 320°C MS detection conditions: SIM measurement TBC (m/z 295 for quantification, m/z 310 for confirmation)
  • GC device GC2010 Plus manufactured by Shimadzu Corporation
  • Column: DB-1 (30m x 0.25mm i.d., df 0.10 ⁇ m)
  • ⁇ Weight average molecular weight (Mw)> The weight average molecular weight (Mw), Z average molecular weight (Mz), and number average molecular weight (Mn) were measured using gel permeation chromatography (GPC) under the following conditions.
  • ⁇ Average transmittance and YI value of light guide plate> The average transmittance and YI value were measured using the following procedure.
  • a test piece of 115 mm x 85 mm was cut out from the light guide plate obtained above, and the end surface was polished by buffing to create a plate-shaped molded product having a mirror surface on the end surface.
  • the plate-shaped molded product after polishing was measured using an ultraviolet-visible spectrophotometer V-670 manufactured by JASCO Corporation to measure the wavelength at an optical path length of 115 mm for incident light with a size of 20 x 1.6 mm and a spread angle of 0°.
  • the spectral transmittance from 350 nm to 800 nm was measured, and the YI value at a field of view of 2° using a C light source was calculated according to JIS K7105.
  • the average transmittance (total light transmittance) was calculated as the average of the spectral transmittances in the wavelength range of 380 to 780 nm.
  • ⁇ Dimensional stability (moisture absorption deformation)> Cut out a 200 mm x 300 mm test piece from the light guide plate obtained above, store the test piece at a temperature of 60 ° C. and a relative humidity of 90% for 500 hours, and measure the dimensional change of the long side before and after storage.
  • the deformation rate was calculated using the following formula.
  • Deformation rate ((Long side length after storage) - (Long side length before storage)) ⁇ (Long side length before storage) x 100 (%)
  • the dimensional stability (moisture absorption change) of the light guide plate was evaluated by rating a change rate of less than 0.10% as ⁇ , a rate of change of 0.10 to 0.15% as ⁇ , and a rate of change of more than 0.15% as ⁇ . .
  • a test piece of 115 mm x 85 mm was cut from the light guide plate obtained above, and the end face was polished at 2.0 m/min with a diamond blade rotating at 8000 rpm using an end face polisher (GCPB-500 manufactured by Megalo Technica Co., Ltd.). Polishing was performed at a feed rate of 0.2 mm to create a plate-shaped molded product with mirror surfaces on the end faces.
  • a flat blue LED light source for TV peak wavelength 445 nm
  • an input current of 0.05 W/mm 2 was applied in an environment of 80°C. , 500h, LED light was irradiated.
  • the wavelength at an optical path length of 115 mm was measured for incident light with a size of 20 x 1.6 mm and a spread angle of 0°.
  • the spectral transmittance from 350 nm to 800 nm was measured, and the YI value at a field of view of 2° using a C light source was calculated according to JIS K7105.
  • the value obtained by subtracting the YI value before the test from the YI value after the test was defined as ⁇ YI.
  • the LED light entrance part of the plate-shaped molded product after the test was visually checked, and the LED durability was evaluated by rating ⁇ if there was no change and rating ⁇ if carbonization occurred.

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Abstract

L'invention fournit une composition de résine à base de styrène à usage optique qui est excellente en termes de transparence, de teinte et de stabilité dimensionnelle, et qui est également excellente en termes de stabilité lumineuse pour un usage à long termes d'une source lumineuse à DEL.　Plus précisément, l'invention concerne une composition de résine à base de styrène à usage optique qui comprend : une résine à base de styrène (A) qui consiste en un copolymère contenant une unité monomère à base de styrène et une unité monomère à base d'ester d'acide (méth)acrylique ; et un photostabilisant à amine encombrée (B). Ledit copolymère comprend 95 à 20% en masse de ladite unité monomère à base de styrène, et 5 à 80% en masse de ladite unité monomère à base d'ester d'acide (méth)acrylique pour 100% en masse dudit copolymère. Enfin, ladite composition de résine à base de styrène à usage optique comprend ０,００１ à １,０ partie en masse dudit photostabilisant à amine encombrée (B) pour 100 parties en masse de ladite résine à base de styrène (A).
PCT/JP2023/016702 2022-05-13 2023-04-27 Composition de résine à base de styrène à usage optique, plaque de guidage de lumière, unité de source de lumière de surface de type à émission latérale, plaque de diffusion de lumière, et unité de source de lumière de surface de type directement sous-jacent WO2023218994A1 (fr)

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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003075648A (ja) * 2001-09-07 2003-03-12 Denki Kagaku Kogyo Kk 導光板
JP2007246810A (ja) * 2006-03-17 2007-09-27 Nippon A & L Kk 光学用樹脂成形品およびそれからなる導光板、拡散板
WO2008010553A1 (fr) * 2006-07-19 2008-01-24 Denki Kagaku Kogyo Kabushiki Kaisha Composition de résine styrène et corps moulé
WO2016129675A1 (fr) * 2015-02-12 2016-08-18 デンカ株式会社 Composition de résine optique à base de styrène
WO2021039368A1 (fr) * 2019-08-30 2021-03-04 東レ株式会社 Composition de résine thermoplastique transparente, procédé de production associé, article moulé obtenu par moulage de composition de résine thermoplastique transparente, et procédé de production pour article moulé
WO2021199501A1 (fr) * 2020-04-01 2021-10-07 デンカ株式会社 Composition de résine optique à base de styrène, plaque de guidage de lumière, et unité de source de lumière plane de type lumière latérale

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003075648A (ja) * 2001-09-07 2003-03-12 Denki Kagaku Kogyo Kk 導光板
JP2007246810A (ja) * 2006-03-17 2007-09-27 Nippon A & L Kk 光学用樹脂成形品およびそれからなる導光板、拡散板
WO2008010553A1 (fr) * 2006-07-19 2008-01-24 Denki Kagaku Kogyo Kabushiki Kaisha Composition de résine styrène et corps moulé
WO2016129675A1 (fr) * 2015-02-12 2016-08-18 デンカ株式会社 Composition de résine optique à base de styrène
WO2021039368A1 (fr) * 2019-08-30 2021-03-04 東レ株式会社 Composition de résine thermoplastique transparente, procédé de production associé, article moulé obtenu par moulage de composition de résine thermoplastique transparente, et procédé de production pour article moulé
WO2021199501A1 (fr) * 2020-04-01 2021-10-07 デンカ株式会社 Composition de résine optique à base de styrène, plaque de guidage de lumière, et unité de source de lumière plane de type lumière latérale

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