WO2007055162A1

WO2007055162A1 - Lightguide plate

Info

Publication number: WO2007055162A1
Application number: PCT/JP2006/322076
Authority: WO
Inventors: Tomoe Nagayama; Haruhiko Kurokawa; Tatsuya Masuki
Original assignee: Mitsubishi Engineering-Plastics Corporation
Priority date: 2005-11-08
Filing date: 2006-11-06
Publication date: 2007-05-18
Also published as: JP2007131679A; JP5073939B2

Abstract

A lightguide plate made of a thermoplastic resin composition which is excellent in luminance, transferability, hue, weatherability, mechanical strength, heat resistance, and moldability. The lightguide plate is obtained by molding an aromatic polycarbonate resin composition comprising an aromatic polycarbonate resin (A) and a caprolactone polymer (B) incorporated therein. The proportions of the ingredient (A) and the ingredient (B) preferably are 85-99.9 parts by weight and 0.1-15 parts by weight, respectively, per 100 parts by weight of the sum of the ingredients (A) and (B).

Description

Specification

Light guide plate

Technical field

TECHNICAL FIELD [0001] The present invention relates to a light guide plate formed by molding a resin composition obtained by blending an aromatic polycarbonate resin with a force prolatatone polymer. More specifically, the present invention relates to a light guide plate comprising the composition as a main component and having excellent brightness, transferability, hue, weather resistance, mechanical strength, heat resistance, and moldability.

Background art

A surface light source device that guides light to a liquid crystal surface is mounted on a liquid crystal display device used for a liquid crystal television, a personal computer, a mobile phone, a PDA, and the like. The light guide plate is used inside the planar light source device, and normally plays a role of uniformly and efficiently guiding light incident from the side surface to the liquid crystal display side. In recent years, a point light source such as an LED or a bar light source such as a cold-cathode tube has been placed at the end of the light guide plate in order to meet the demands for thin, lightweight, power-saving, high brightness, and high definition liquid crystal display devices. An edge light type that uses a linear light source by converting it to a planar light source is often used. The light guide plate in this surface light source device usually has a wedge shape or a flat plate shape having a uniformly inclined surface on one side, and a prism or dot-shaped uneven pattern is formed on the plane. Has been.

[0003] Conventionally, the light guide plate has been molded from a resin material such as polymethyl methacrylate (PMMA)! In recent years, the interior of the device in which the light guide plate is incorporated tends to become hot, and it has higher heat resistance. V. A light guide plate made of aromatic polycarbonate resin is often used.

[0004] Aromatic polycarbonate resin is excellent in mechanical properties, thermal properties, electrical properties, and weather resistance, but its light transmittance is generally lower than that of PMMA. When a surface light source body is composed of a light guide plate made of light and a light source, there is a problem that the luminance is low. As a method for solving such a problem, several methods have been proposed to increase the luminance of the light guide plate made of aromatic polycarbonate resin.

[0005] For example, a method of adding specific acrylic resin and alicyclic epoxy has been proposed (see Patent Document 1). In addition, as a substrate for liquid crystal display panels with excellent optical properties and heat resistance, 3,3,5-trimethyl — 1, 1 di (4 phenol) cyclohexylidene, bisphenol A and bisphenol components are used. A copolymerized polycarbonate resin has been proposed (see Patent Document 2).

Patent Document 1: Japanese Patent Application Laid-Open No. 11 158364

Patent Document 2: Japanese Patent Laid-Open No. 11 174424

Disclosure of the invention

Problems to be solved by the invention

[0008] However, in the method described in Patent Document 1, it is impossible to increase the light transmittance and the brightness because the resulting resin molded product cannot be turbid due to the addition of acrylic resin. However, there was a problem that a sufficient improvement effect was not observed even when alicyclic epoxy was added. Further, even with the method described in Patent Document 2, the weather resistance and hue were insufficient.

[0009] The object of the present invention is to solve the above-mentioned problems and to simultaneously satisfy various properties such as hue and transferability as well as brightness, weather resistance, mechanical strength, heat resistance, and moldability. It is to provide an excellent light guide plate.

Means for solving the problem

[0010] As a result of intensive studies to achieve the above object, the present inventors have found that a light guide plate in which a specific amount of a force prolatatone polymer is blended in an aromatic polycarbonate resin is not only a luminance but also a transfer. We have found that this is a well-balanced, highly practical light guide plate that simultaneously satisfies various properties such as heat resistance, hue, weather resistance, mechanical strength, heat resistance, and moldability. It was.

[0011] That is, the gist of the present invention is that a light guide plate formed by molding an aromatic polycarbonate resin composition obtained by blending (A) an aromatic polycarbonate resin with (B) a force prolacton-based polymer. Exist.

The invention's effect

[0012] The light guide plate of the present invention has high brightness, high transferability, and excellent hue, weather resistance, mechanical strength, and heat resistance as compared with a conventional light guide plate made of aromatic polycarbonate resin. So mobile phone, mobile terminal, camera, watch, laptop, display, lighting, signal, auto It can be expected to be used as a light guide plate in a wide range of applications, such as car tail lamps and heat display for electromagnetic cookers.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

[0014] (A) Aromatic polycarbonate resin

The component (A) in the present invention is an aromatic polycarbonate resin, and is formed by, for example, reacting an aromatic dihydroxy compound and a carbonate precursor, or a small amount of a polyhydroxy compound in combination with these compounds. A linear or branched thermoplastic aromatic polycarbonate polymer or copolymer.

[0015] The (A) aromatic polycarbonate resin in the present invention is not particularly limited, and can be produced by a known method, for example, an interfacial polymerization method, a melt transesterification method, a solid-phase transesterification of a prepolymer. The law etc. can be mentioned.

[0016] Aromatic dihydroxy compounds used as raw materials include 2, 2 bis (4-hydroxyphenol) propane (= bisphenol A), 2, 2 bis (3, 5 jib-mouthed 4 hydro Xyphenyl) propane (= tetrabromobisphenol A), bis (4-hydroxyphenol) methane, 1,1-bis (4hydroxyphenol) ethane, 2,2 bis (4hydroxyphenol) Butane, 2,2 bis (4 hydroxyphenol) octane, 2,2 bis (4 hydroxy—3-methylphenol) propane, 1,1-bis (3-tert-butyl 4-hydroxyphenol) propane, 2, 2 bis (4-hydroxy 3, 5 dimethylphenol) propane, 2, 2 — bis (3 bromo 4 hydroxyphenol) propane, 2, 2 bis (3, 5 dichloro-4-hydroxyphenol) propane, 2, 2 bis (3 1-hydroxy 4-hydroxy) Propane, 2, 2 bis (3 cyclohexyl 4 hydroxyphenol) propane, 1, 1—bis (4-hydroxyphenol) 1 phenol norethan, bis (4-hydroxyphenol) diphenylmethane 2, 2, bis (4 hydroxyphenol) 1, 1, 1-trichloropropane, 2, 2, bis (4 hydroxyphenol) 1, 1, 1, 3, 3, 3 2, 2-bis (4-hydroxyphenol) 1, 1, 1, 3, 3, 3 Bis (hydroxyaryl) alkanes exemplified by hexafluoropropane, etc .; 1, 1-bis (4 Hydroxyphenol) cyclopentane, 1,1-bis (4 hydroxyphenol) cyclohexane, 1,1-bis (4 hydro Bis (hydroxyaryl) cycloalkanes exemplified by 1,3,5-trimethylcyclohexane; 9, 9-bis (4-hydroxyphenol) fluorene, 9, 9-bi Forced structure-containing biphenols exemplified by bis (4-hydroxy-3-methylphenol) fluorene, etc .; exemplified by 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, etc. Dihydroxydiaryl ethers; dihydroxydiarylsulfides exemplified by 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxy3,3'-dimethyldiphenylsulfide, etc .; 4,4'-dihydroxy Dihydroxydiaryl sulfoxides exemplified by sidiphenyl sulfoxide, 4,4'-dihydroxy 3,3'-dimethyldiphenyl sulfoxide, etc. 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone, and the like. Hydroxylquinones, resorcins, 4,4′-dihydro Examples include xydiphenol.

Of these, bis (4-hydroxyphenol) alkanes are preferable, and 2, 2 bis (4-hydroxyphenol) propane (= bisphenol A) is particularly preferable from the viewpoint of impact resistance. ).

These aromatic dihydroxy compounds may be used alone or in combination of two or more.

[0018] Carbonate precursors, carbonate esters, haloformates, and the like are used as the carbonate precursor to be reacted with the aromatic dihydroxy compound, and specifically, phosgene; diphenyl carbonate, ditolyl carbonate, and the like. Diaryl carbonates; Dialkyl carbonates such as dimethyl carbonate and jetyl carbonate; and dino-mouth formate of divalent phenol. These carbonate precursors can also be used alone or in combination of two or more.

[0019] (A) The aromatic polycarbonate resin may be a branched aromatic polycarbonate resin obtained by copolymerizing a trifunctional or higher polyfunctional aromatic compound. The polyfunctional aromatic compound can be used by substituting a part of the aromatic dihydroxy compound, and the amount used is in the range of 0.01 to 10 mol% with respect to the aromatic dihydroxy compound. the scope of the preferred tool from 0.1 to 2 mol ^_0/0 is more preferable. [0020] In the reaction by the interfacial polymerization method, in the presence of an organic solvent inert to the reaction and an aqueous alkali solution, the pH is usually kept at 9 or higher, and the aromatic dihydroxy compound, and the molecular weight is adjusted as necessary. Using an antioxidant (terminal terminator) and an antioxidant to prevent aromatic dihydroxy compounds from reacting with phosgene, then adding a polymerization catalyst such as tertiary amine or quaternary ammonium salt Then, polycarbonate is obtained by interfacial polymerization. The addition amount of the molecular weight modifier is not particularly limited as long as the phosgene power is between the start of the polymerization reaction. The reaction temperature is, for example, 0 to 40 ° C., and the reaction time is, for example, 10 minutes to 6 hours.

[0021] Here, the organic solvent inert to the reaction includes chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, black mouth form, monochrome mouth benzene and dichlorobenzene, and aromatics such as benzene, toluene and xylene. A hydrocarbon etc. are mentioned. Examples of the alkaline compound used in the alkaline aqueous solution include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide.

[0022] Examples of the molecular weight regulator include a compound having a monovalent phenolic hydroxyl group.

Examples of the compound having a monovalent phenolic hydroxyl group include m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol and p-long chain alkyl-substituted phenol. It is done. The amount of the molecular weight regulator used is preferably 50 to 0.5 mol, more preferably 30 to 1 mol, per 100 mol of the aromatic dihydroxy compound.

[0023] Polymerization catalysts include tertiary amines such as trimethylamine, triethylamine, triptylamamine, tripropylamine, trihexylamine, pyridine, etc .: trimethylbenzyl ammonium chloride, tetramethyl ammonium chloride, triethylbenzyl ammonium Umuku quaternary ammonium salt such as mouth ride.

[0024] The reaction by the melt transesterification method is, for example, an ester exchange reaction between a carbonic acid diester and an aromatic dihydroxy compound. Examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, jetyl carbonate and di-tert-butyl carbonate, substituted diphenyl carbonates such as diphenyl carbonate and ditolyl carbonate, and the like. The carbonic acid diester is preferably diphenyl carbonate or substituted diphenyl carbonate, and more preferably diphenyl carbonate. [0025] Generally, a polycarbonate having a desired molecular weight and a terminal hydroxyl group amount can be obtained by adjusting the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound or by adjusting the degree of vacuum during the reaction. Is obtained. As a more aggressive method, an adjustment method in which a terminal terminator is added separately during the reaction is also well known. In this case, examples of the terminal terminator include monovalent phenols, monovalent carboxylic acids, and carbonic acid diesters. The amount of terminal hydroxyl groups greatly affects the thermal stability, hydrolysis stability, color tone, etc. of the product polycarbonate. Depending on the application, in order to have practical physical properties, it is preferably 1, OOOppm or less, more preferably 700 ppm or less.

[0026] In the polycarbonate produced by the transesterification method, the amount of terminal hydroxyl groups is preferably 10 Oppm or more. By using such a terminal hydroxyl group amount, it is possible to suppress a decrease in the molecular weight and to improve the color tone. Therefore, it is preferable to use an equimolar amount or more of carbonic acid diester with respect to 1 mol of aromatic dihydroxy compound, and use it in an amount of 1.01 to 1.30 monolayer! It's better!

[0027] When a polycarbonate is produced by a transesterification method, a transesterification catalyst is usually used. The transesterification catalyst is not particularly limited, but alkali metal compounds and z or alkaline earth metal compounds are preferred. In addition, a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound can be used in combination. As the transesterification reaction using the above raw materials, the reaction is carried out at a temperature of 100 to 320 ° C., and finally, under reduced pressure of 2 mmHg or less, while removing by-products such as aromatic hydroxy compounds and the like, The method of performing a condensation reaction is illustrated.

[0028] The melt polycondensation can be carried out in a notch manner or continuously, but in view of the stability of the resin composition of the present invention, it is preferably conducted in a continuous manner. As the catalyst deactivator in the transesterification polycarbonate, it is preferable to use a compound that neutralizes the catalyst, such as a xio-containing acidic compound or a derivative formed therefrom. The compound neutralizing such a catalyst is preferably added in an amount of 0.5 to 10 equivalents, more preferably 1 to 5 equivalents, relative to the alkali metal contained in the catalyst. In addition, the compound that neutralizes such a catalyst is added to the polycarbonate in an amount of preferably 1 to L00 ppm, more preferably 1 to 20 ppm. [0029] The molecular weight of the (A) aromatic polycarbonate resin used in the present invention is a viscosity average molecular weight converted from the solution viscosity [Mv] force 0000 to 25000, preferably 12000 to 24000, more preferably 14000 to 23000. By setting the viscosity average molecular weight of the aromatic polycarbonate to 10000 or more, the mechanical strength tends to be further improved, and it is more preferable when used for applications requiring high mechanical strength. On the other hand, when the viscosity average molecular weight is 25000 or less, there is a tendency that the decrease in fluidity can be improved, and the viewpoint power of easy molding processability is also preferred.

[0030] In addition, two or more types of aromatic polycarbonate resin having different viscosity average molecular weights may be mixed. Of course, you may mix the aromatic polycarbonate resin whose viscosity average molecular weight is outside the said suitable range.

[0031] Here, the viscosity average molecular weight [] ν] refers to the intrinsic viscosity [η] (unit dlZg) at a temperature of 20 ° C using a Ubbelohde viscometer using methylene chloride as a solvent. degree equation, i.e., r? = 1. means a value is also calculated 23 X 10- ⁴ Μ ° · ⁸³ force. Here, the limiting viscosity [r?] Is the specific viscosity [7?] Measured at each solution concentration [C] (gZdl) and calculated by the following formula.

Value.

[0032] [Equation 1] = lim¾ / c

c → 0 ^r

[0033] In order to improve the appearance of the molded product and the fluidity, the (A) aromatic polycarbonate resin in the present invention may contain an aromatic polycarbonate oligomer. The viscosity average molecular weight [Mv] of the aromatic polycarbonate oligomer is preferably 1500 to 9500, more preferably J to 2000 to 9000. The aromatic positive carbon digomer is preferably used in an amount of 30% by weight or less of the component (Α).

[0034] Further, (ii) aromatic polycarbonate resin in the present invention uses aromatic polycarbonate resin regenerated from used products made only of virgin raw materials, so-called material-recycled aromatic polycarbonate resin. May be. Used products include optical recording media such as optical discs, light guide plates, automotive window glass, automotive headlamp lenses 'vehicle transparent members such as windshields, containers such as water bottles, glasses lenses, and sound barriers' glass. Preferably, building materials such as glass windows and corrugated sheets are used. It is also possible to use non-conforming products, sprue, runners, etc., obtained powdered products, or pellets obtained by melting them. The regenerated aromatic polycarbonate resin is preferably 80% by weight or less of component (A), more preferably 50% by weight or less.

[0035] (B) Force prolatatatone polymer

The (B) force prolatatatone polymer according to the present invention contains at least 70% by weight, preferably 75% by weight or more, more preferably 80% by weight or more, of a structural unit derived from ε-force prolatatone in the polymer. It is a polymer or a copolymer. Monomers that can be copolymerized with ε-force prolatatatone include: / 3 Lactone monomers such as propiolataton, pivalolatatone, butyrolatataton, ethylene oxide, 1,2 propionoxide, 1,3 propylene oxide, alkylene oxide such as tetrahydrofuran, Examples thereof include unsaturated monomers such as styrene, methyl methacrylate and butadiene and coupling agents such as dimethyl terephthalate and diphenyl carbonate.

[0036] (i) As a force prolatatone polymer, ε is a force prolatatone polymer in which a part of the hydrogen atom of the methylene chain of one force prolatatone unit may be substituted with a halogen atom or a hydrocarbon group. The terminal may be terminal-modified by esterification, etherification or the like. Although there is no particular limitation on the production method of strong prolataton-based polymer, ε-strength prolataton is ring-opening polymerized using a suitable initiator such as alcohol, glycol, water, etc. and a catalyst such as titanium tetrabutoxide, tin chloride. The method is used.

[0037] The molecular weight of the (ii) force prolatatatone polymer used in the present invention is preferably 1000 to 100,000 in terms of polystyrene-reduced number average molecular weight by GPC. If the number average molecular weight is less than 1000, the heat resistance becomes insufficient, and if it exceeds 100000, the workability and transparency are likely to decrease. Transparent '14, force, more preferably ί or 4000-50000, more preferably ί. 8000-30000.

[0038] In the present invention, the blending ratio of the (Α) component and the (Β) component is such that the (Α) component is 85 to 99.9 weights in a total of 100 parts by weight of the (Α) component and the (Β) component. Parts, (Β) component is 0.1-15 parts by weight. When the amount of the component (ii) is 85 parts by weight or more, heat resistance and mechanical strength can be made sufficient, but if it is too much, moldability, transferability and brightness may be lowered. In the present invention The component (A) in the total 100 parts by weight of the component (A) and the component (B) is more preferably 8

It is 8 to 99.5 parts by weight, and the component (B) is preferably 0.5 to 12 parts by weight.

[0039] (C) Phosphorus compound

The phosphorus compound used as the component (C) of the present invention is a compound containing phosphorus in the molecule.

Of these, phosphites represented by the following general formula (I) are preferable.

[0040] [C 1] Phosphite

[C-1] Phosphite used as the component (C) of the present invention is represented by the following general formula (I).

[0041] General formula (I)

[Chemical 1]

(In general formula (I), R ′ is an alkyl group or an aryl group, which may be the same or different.)

In general formula (I), when R ′ is an alkyl group, an alkyl group having 1 to 30 carbon atoms is preferable, and when R ′ is an aryl group, an aryl group having 6 to 30 carbon atoms is preferable.

[0044] Preferable examples of the phosphite represented by the above general formula (I) include distearyl pentaerythritol diphosphite, dinol pentaerythritol diphosphite, bis-norphenol pentaerythritol. Diphosphite, bis (2,4 di tert-butyl phosphine) pentaerythritol diphosphite, bis (2,6 di-tert-butyl-4-methyl phthal) pentaerythritol diphosphite, bis (2, 6 Di-tert-butyl 4-ethylpropyl) pentaerythritol diphosphite, bis (2,6 di-tert-butyl-4-isopropylphenyl) pentaerythritol diphosphite, bis (2,4 dicumylphenol) Examples include pentaerythritol diphosphite.

[0045] Of these, more preferred are distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenol) pentaerythritol diphosphite, bis (2,6-ditert-butyl-4-methylphenol). ) Pentaerythritol diphosphite, and Among them, bis (2,4 di-tert-butylphenol) pentaerythritol diphosphite and bis (2,6 di-tert-butyl-4-methylphenol) pentaerythritol diphosphite are preferable.

[0046] The phosphorus compound used as the component (C) of the present invention is represented by the following [C-2] phosphate ester represented by the following general formula (II) and general formulas (III) to (VI). [C3] Organophosphate metal salt may be used.

[0047] [C 2] Phosphate esterolate

The phosphate ester used as the component (C) of the present invention is represented by the following general formula (II).

[0048] General formula (Π)

0 = P (OH) (OR)---(II)

n 3-n

(In the general formula (II), R is an alkyl group or an aryl group, and may be the same or different. N represents an integer of 0 to 2.)

[0049] In the general formula (II), R is preferably an alkyl group having 1 to 30 carbon atoms or 6 to 3 carbon atoms.

An aryl group of 0, and more preferably an alkyl group having 2 to 25 carbon atoms, a phenol group, a non-aryl group, a stearyl group, 2, 4 di-tert-butyl group, 2, 4-di-tert-butyl methylphenol group, tolyl group.

From the viewpoint of further improving transparency, luminance, and hue, a phosphate ester represented by the following general formula (II I) is preferable.

[0050] General formula (II I)

0 = P (OH) (OR ") · '· (Π— I)

η '3- η'

(In the general formula (II I), R ″ is an alkyl group having 2 to 25 carbon atoms, which may be the same or different. Η ′ is 1 or 2.)

Here, the alkyl group includes octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group. And octadecyl group.

[0051] [C 3] Organophosphate metal salt

The organophosphate metal salt used as the component (C) of the present invention is represented by the following general formulas (III) to (VI). [0052] General formula (ΠΙ)

[Chemical 2]

(In the general formula (III), Ri to R ⁴ are alkyl groups or aryl groups, and may be the same or different, and M represents a metal selected from an alkaline earth metal and zinc. )

[0054] General formula (IV)

[Chemical 3]

[In general formula (IV), R ⁵ represents an alkyl group or an aryl group, and M represents a metal selected from an alkaline earth metal and zinc.)

[0056] General formula (V)

[Chemical 4]

(In general formula (V), R ^{6 to} R ^U are alkyl groups or aryl groups, and may be the same or different. M ′ represents a metal atom that becomes a trivalent metal ion. To express. )

[0058] General formula (VI)

[Chemical 5]

(In the general formula (VI), R to R ^{14 each} represents an alkyl group or an aryl group, and may be the same or different. M ′ represents a metal atom that becomes a trivalent metal ion. And two M's may be the same or different.)

[0060] In the general formulas (III) to (VI), Ri to R "are preferably each an alkyl group having 1 to 30 carbon atoms or an aryl group having 6 to 30 carbon atoms, and more preferably. Respectively, an alkyl group having 2 to 25 carbon atoms, a phenol group, a non-phenolic group, a stearylphenol group, a 2,4-di-tert-butylphenol group, and a 2,4-di-tert-butyl-methylphenol. -Group or tolyl group.

[0061] From the viewpoint of further improving the transparency, brightness, and hue, RR "is preferably an octyl group, a 2-ethylhexyl group, or an isooctyl group, each preferably an alkyl group having 2 to 25 carbon atoms. Nonyl group, isononyl group, decyl group, isodecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, hexadecyl group, and octadecyl group are more preferable.

[0062] In the general formulas (III) to (VI), M is preferably zinc.

[0063] In the general formulas (III) to (VI), M 'is preferably aluminum.

[0064] Particularly preferred organophosphate metal salts include a mixture of a zinc salt of monostearyl acid phosphate and a zinc salt of distearyl acid phosphate, an aluminum salt of monostearyl acid phosphate and distearyl acid phosphate. Mention may be made of mixtures of aluminum salts. Such a metal salt of an organic phosphate is commercially available as LBT-1830 manufactured by Zhigaku Kogyo or LBT-1813 manufactured by Zhigaku Kogyo.

[0065] The phosphorus compounds used as the component (C) of the present invention may be used singly or in combination of two or more. When used alone, those selected from [C-1] are preferred. What is necessary is just to select and determine suitably the combination at the time of using together according to the various characteristics requested | required of the light-guide plate of this invention. One or two or more of the same skeleton structure may be used from the group having different skeleton structures, respectively. [0066] The content of the component (C) in the present invention is 0.001 to 0.3 parts by weight with respect to 100 parts by weight of the total of the components (A) and (B). If the content of component (C) is too high or too low, the melt heat stability, brightness, and hue may decrease.

[0067] (D) Polyorganosiloxane

The resin composition of the present invention can further contain a polyorganosiloxane for the purpose of further improving transparency, luminance, and hue.

[0068] The polyorganosiloxane (D) in the present invention has a phenyl group in at least a side chain. In particular, a compound having a branched siloxane structure may be a preferred single compound or a mixture. In the case of a mixture, a combination of a polyorganosiloxane having at least a phenyl group in the side chain and a polyorganosiloxane having at least a branched siloxane structure is also preferred.

[0069] In addition, the component (D) in the present invention has a kinematic viscosity at 25 ° C of 1 to 200 cSt, preferably 5 to: LOOcSt, and more preferably 10 to 50 cSt. Use of a material having a kinematic viscosity of lcSt or more is preferable because it suppresses the amount of gas generated during molding and lowers the possibility of forming defects due to gas, such as unfilling, gas burnout, and transfer defects. On the other hand, by using a kinematic viscosity having a viscosity of 2 OOcSt or less, the effect of improving the transparency and hue of the resin composition of the present invention becomes more remarkable. The polyorganosiloxane used in the present invention can be easily obtained by a conventional organic reaction.

[0070] The content of the component (D) in the present invention is preferably 0.01 to 1 part by weight, more preferably 0.001 parts by weight with respect to 100 parts by weight of the total of the components (A) and (B). 03 to 0.8 parts by weight. (D) By setting the content of the component to 0.01 parts by weight or more, it is effective to improve the transparency, brightness, and hue of the resin composition, and by setting it to 1 part by weight or less, depending on the gas The possibility of occurrence of molding defects such as unfilling, gas burnout, and transfer defects can be further reduced.

[0071] In addition to the components (A) to (D) described above, the aromatic polycarbonate resin composition used in the present invention may contain other various resin additives as long as it does not impair the purpose of the present invention. An agent may be contained. For example, various types of resin additives include antioxidants, mold release agents, dyes and pigments, weather resistance improvers, antistatic agents, antifogging agents, lubricants, antiblocking agents, flame retardants, fluidity One or more improvers, plasticizers, dispersants, antibacterial agents, filler fillers and the like may be contained.

[0072] Antioxidant

Examples of the acid / antioxidant preferably blended in the aromatic polycarbonate resin composition include a hindered phenolic acid / antioxidant. Specific examples include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenol) propionate], octadecyl-3- (3,5-ditert-butyl-4-hydroxyphenol) probione. Thiothioethylene bis [3- (3,5-di-tert-butyl-4-hydroxyphenol) propionate], N, N 'hexane-1,6 diylbis [3- (3,5 di-tert-butyl) Ru 4-hydroxyphenylpropionamide), 2,4 dimethyl-6- (1-methylpentadecyl) phenol, jetyl [[3,5 bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] phosphoate, 3, 3 ', 3 ", 5, 5', 5" —hexa tert-butyl-a, a, a "— (mesitylene 1, 2, 4, 6 tolyl) tree p cresol, 4, 6 bis (octylthiomethyl) o Cresol, ethylene bis (ox Siethylene) bis [3- (5-tert-butyl-1-hydroxy-1-m-tolyl) propionate], hexamethylenebis [3- (3,5 di-tert-butyl-4-hydroxyphenol) propionate], 1, 3, 5 Tris (3,5 di-tert-butyl-4-hydroxybenzyl) -1,3,5 triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6 di-tert-butyl- 4— (4,6 bis (octylthio) —1,3,5 triazine-2-ylamino) phenol etc. Among them, especially pentaerythritol tetrakis [3- (3,5-di-tert-butyl- 4-Hydroxyphenol) propionate], Octadecyl 3- (3,5-di-tert-butyl 4-hydroxyphenol) propionate is preferred, these two phenolic antioxidants are Ilganock from Chemicals It sold under the name 1010 and Iruganokkusu 1076.

[0073] The mixing ratio of the phenolic anti-oxidation agent is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of the total of the component (A) and the component (B). If the blending amount of the phenolic anti-oxidation agent is less than 0.01 parts by weight, the effect as an anti-oxidation agent is insufficient. The effect is not obtained. [0074] Release agent

The release agent preferably blended in the aromatic polycarbonate resin composition is at least one compound selected from aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, and aliphatic hydrocarbon compounds.

[0075] Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent or trivalent carboxylic acids. Here, the aliphatic carboxylic acid includes an alicyclic carboxylic acid. Among these, preferable aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferable. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, force puric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, melicic acid, tetrariacontanoic acid, montan. Examples include acids, adipic acid, and azelaic acid.

[0076] As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, the same aliphatic carboxylic acid as that described above can be used. Examples of the alcohol that reacts with the aliphatic carboxylic acid to form ester include saturated or unsaturated monohydric alcohol, saturated or unsaturated polyhydric alcohol, and the like. These alcohols may have a substituent such as a fluorine atom or an aryl group. Of these alcohols, monovalent or polyvalent saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric alcohols or polyhydric alcohols having 30 or less carbon atoms are preferred. The term “aliphatic” as used herein includes alicyclic compounds. Specific examples of these alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycolanol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluorinated propanol, neopentylene. Examples include glycol, ditrimethylolpropane, dipentaerythritol, and the like. These esterified compounds of aliphatic carboxylic acid and alcohol may be a mixture of a plurality of compounds that contain aliphatic carboxylic acid and Z or alcohol as impurities.

[0077] Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (mixture based on myristyl valmitate), stearyl stearate, beryl behenate, stearyl behenate, glycerol mono Palmitate, glycerol monostearate, glycerol dis Mention may be made of tearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate.

[0078] Examples of the aliphatic hydrocarbon include liquid paraffin, norafin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and an α-olefin oligomer having 3 to 12 carbon atoms. Here, the aliphatic hydrocarbon also includes alicyclic hydrocarbons. Moreover, these hydrocarbon compounds may be partially oxidized.

[0079] The compounding ratio of the release agent is usually from 0.001 to 1 part by weight based on 100 parts by weight of the total of the component (ii) and the component (ii). If the compounding ratio of the release agent exceeds 1 part by weight, there are problems such as degradation of hydrolysis resistance and mold contamination during injection molding. One type of release agent can be used, but multiple types can be used in combination.

[0080] Dyeing pigment

Examples of dyes and pigments that are preferably blended in the aromatic polycarbonate resin composition include inorganic pigments, organic pigments, and organic dyes. The blending ratio of the dye / pigment is usually 1 part by weight or less, preferably 0.3 parts by weight or less, more preferably 0.1 parts per 100 parts by weight in total of the components (ii) and (ii). Less than parts by weight. The colorant can be used alone or in combination of two or more.

[0081] Furthermore, the aromatic polycarbonate resin composition according to the present invention may contain other resin as long as the effects of the present invention are not impaired. Examples of other resins include polyamide resins, polyimide resins, polyetherimide resins, polyurethane resins, polyphenylene ether resins, polyphenylene sulfide resins, polysulfone resins, polyethylene, polypropylene, and other polyolefin resins. Examples thereof include styrene-based resins such as fat, polystyrene, and acrylonitrile-styrene copolymer, polymethacrylate resin, phenol resin, and epoxy resin.

[0082] The method for producing the aromatic polycarbonate resin composition according to the present invention is not particularly limited, but can be produced by a general method for producing a thermoplastic resin composition. For example, (Α) aromatic polycarbonate resin, (Β) force prolatatone polymer, (C) phosphorus compound, (D) polyorganosiloxane, and additive components blended as needed are added to tumbler or Henschelmi. A resin composition is prepared by premixing using various mixers such as Kisani, and then melt-kneading with a banner mixer, roll, brabender, single-screw kneading extruder, twin-screw kneading extruder, kneader, etc. can do. Further, the resin composition can be produced without mixing each component in advance, or by mixing only a part of the components in advance and supplying them to an extruder using a feeder and melt-kneading them.

A resin composition can also be produced by melt-kneading some components in advance to produce an intermediate composition, and then blending other components and melt-kneading them. For example, an intermediate composition obtained by melt-kneading the component (A) and the component (C) is blended with the component (B), the component (D), and other necessary additional components, melt-kneaded, and then mixed with the resin. The composition can be produced, and the (A) component and other additive components are combined with the intermediate composition obtained by melt-kneading the (B) component, (C) component, and (D) component. It can also be melt kneaded to produce a resin composition.

Furthermore, a master batch may be manufactured by melt-kneading a part of the components, and the obtained master batch and other components may be melt-kneaded to obtain the desired resin composition. For example, after the (D) component is blended with a small amount of the (A) component and melt-kneaded to produce a master batch of the (D) component, the obtained master batch and other additive components are blended and melt-kneaded. Examples thereof include a method for obtaining a desired rosin composition.

[0083] The light guide plate of the present invention is obtained by molding the above resin composition. Examples of the molding method include injection molding, compression molding, injection compression molding, blow molding, and rotational molding. Generally, injection molding is employed.

[0084] Further, the light guide plate has a wedge shape, a flat plate shape, and the like, and any of them has a prism-shaped or dot-shaped uneven pattern formed on at least one plane. Such an uneven pattern is imparted by transferring an uneven portion formed on a part of the surface of the mold during injection molding. It is convenient and preferable to form the concavo-convex part in the nest that is a part of the mold.

[0085] Further, since the fluidity is improved by blending the force prolatatatone polymer, molding at a lower cylinder temperature is possible. By lowering the cylinder temperature, it is possible to reduce the mechanical strength due to the deterioration of the resin and to reduce the yellowing of the resin, and it is possible to obtain a light guide plate that is superior in impact strength and hue. In addition, due to the improvement in fluidity, the possibility of large-scale molding with a thin wall can be expected.

[0086] When the light guide plate of the present invention is used in a liquid crystal display device, there is a backlight type surface light source body in which light sources are arranged in an edge type or a direct type. In addition to fluorescent lamps, self-luminous materials such as cold cathode tubes, LEDs, laser diodes, and organic EL can be used as the light source.

[0087] The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded. The raw materials used in the following examples are shown in Table 1.

[0088] [Table 1]

[0089] (1) Viscosity average molecular weight:

The intrinsic viscosity [7?] At 20 ° C in methylene chloride was measured with an Ubbelohde viscometer, and determined by the following formula.

[0090] [7?] = 1. 23 X 10— ⁴ X (Mv) ⁰⁸³

[0091] (2) Average brightness, brightness uniformity, and color temperature:

A light guide plate with a wedge-shaped cross section having a width of 40 mm, a length of 60 mm, a thin-walled portion of 0.7 mm, and a thick-walled portion of 0.9 mm and having a prism-shaped uneven pattern formed on an inclined surface was formed. The prism shape was given by a mold with a pitch of 200 μm and a depth of 8 μm. The molding machine used was Sodick TR100EH manufactured by Sodick Plastics, and injection molding was performed under conditions of a mold temperature of 125 ° C and a cylinder temperature of 290 ° C to 320 ° C.

[0092] Next, in the dark room, the light guide plate is disposed so that the concave / convex pattern forming surface is on the lower surface side, and a cold cathode tube is disposed at the thick end portion, thereby providing an edge type backlight type surface light source body. A luminance meter (“Topcon BM-7” manufactured by Topcon) was installed at a position 30 cm above the surface on which the concave / convex pattern was not formed, and the luminance and color temperature were measured. The average brightness was obtained by averaging the measured values at 9 locations, 3 levels wide and 3 levels long. In addition, the luminance uniformity was calculated by the equation (minimum luminance value Z maximum luminance value) X 100 (%).

[0093] The color temperature is a numerical value representing the relative intensity of blue and red, defined as "temperature of a black body when a perfect black body emits light of the same color as that light". The higher the value, the stronger the blue color. When used for applications such as displays, the higher the color temperature, the better the power display visibility, so the light guide plate is required to have a higher color temperature.

[0094] (3) Formability:

The cylinder temperature when a predetermined transfer property (prism depth: 8 m) is obtained is shown. The better the fluidity, the easier it is to mold (fill) at lower cylinder temperatures. If the cylinder temperature is too high, thermal degradation of the resin tends to occur, so it can be said that the material is superior to the force that can achieve the same transferability at a lower cylinder temperature. The preferred cylinder temperature is 3 10 ° C or lower, more preferably 300 ° C or lower.

[0095] (4) Transferability:

The light guide plate is molded under conditions of constant molding temperature (cylinder temperature: 310 ° C) to evaluate transferability. I was worth it. The surface of the concavo-convex pattern was observed with a scanning confocal laser microscope (SHIMADZU / OL YMPUS “OLS1100”), and the depth of the surface prism was measured.

[0096] Examples 1 to 12 and Comparative Examples 1 to 8

After blending the raw materials in the proportions shown in Table 2, melt-kneaded at a cylinder temperature of 250 ° C using a single-screw extruder with a screw diameter of 40 mm (“VS-40” manufactured by Tanabe Plastics Machinery Co., Ltd.). Pellets were made by cutting. Further, the obtained pellets were dried by a hot air circulation dryer at 120 ° C. for 5 to 7 hours, and then a light guide plate molded product for evaluation was molded.

[0097] [Table 2]

[0098] [Table 3] Example

Item Unit

7 8 9 10 11 12

Component A PC 94 94 94 94 94 92

Component B PCL 6 6 6 6 6 8

PEP24G 0.02

PEP36 0.1 0.04 0.04

C component

Composition AX-71 parts by weight

LBT1830 0.02

D component SH556 0.03 0.03 0.03 0.03

S-100A 0.03 other

AS2112 0.04

Average brightness cd / m ² 1488 1476 1401 1418 1352 1550 Made luminosity Characteristics Brightness uniformity% 83 83 82 82 82 82

E / jm. I K 6863 6840 6738 6750 6663 6902 Formability Cylinder temperature. C 300 300 300 300 300 290 Transferability

Prism depth μ m 8.0 8.0 8.0 8.0 8.0 8.0

(Forming at 310 ° C) Table 4] Comparison example

Item Unit

1 2 3 4 5 6

Component A PC 100 100 100 100 100 100

B component PCL 0 0 0 0 0 0

PEP24G 0.02

PEP36 0.04 0.1

C component

Composition AX-71 parts by weight 0.04

LBT1830 0.04 0.02

D component SH556 0.03 0.03 0.03 0.03 0.03 0.03

S-100A

Other

AS2112 0.04 Average Luminance cd / m ² 1080 1020 1033 1054 1046 989 Manufactured Characteristics Luminance Uniformity% 83 82 82 82 83 80 Color / dish i K 6398 6098 6115 6331 6211 5921 Formability Cylinder temperature. C 320 320 320 320 320 320 Transferability

Prism depth U m 1.1 1.1 1.1 1.1 1.1 1.1

(310 ° C molding) [0100] [Table 5]

[0101] From Tables 2 to 5, it can be seen that the luminance and hue are improved by the addition of the force prolatatatone polymer. It can also be seen that molding (filling) can be performed at a low cylinder temperature, and transferability equivalent to that of the comparative example can be obtained. Furthermore, when molding is performed at the same cylinder temperature, the addition of a force prolatatatone polymer provides better transferability.

Claims

The scope of the claims

[1] A light guide plate formed by molding an aromatic polycarbonate resin composition obtained by blending (A) an aromatic polycarbonate resin with (B) a force prolatatone polymer.

[2] A total of 100 parts by weight of the component (A) and the component (B) is characterized in that the component (A) contains 85 to 99.9 parts by weight and the component (B) contains 0.1 to 15 parts by weight. The light guide plate according to claim 1.

[3] The phosphorous compound represented by the following general formula (I) is contained in an amount of 0.001 to 0.3 parts by weight with respect to 100 parts by weight of the total of the components (A) and (B). Item 3. The light guide plate according to Item 1 or 2.

[Chemical 1]

H ₂ C CH ₂ 0

R'— O— P, ヽ P— O— R '■ ■ ■ C I)

OH ₂ C, CH ₂ 0

(In the general formula (I), R ′ represents an alkyl group or an aryl group, which may be the same or different.)

[4] For 100 parts by weight of the total of component (A) and component (B), (D) polyorganosiloxane having a phenyl group at least in the side chain and a kinematic viscosity at 25 ° C of 1 to 200 cSt. The light guide plate according to any one of claims 1 to 3, comprising 0.01 to 1 part by weight.