JP2012068381A - Luminance increase film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminance increase film having superior transparency, transferring property, scratch resistance, warp resistance and recyclability and composed of a laminated polycarbonate resin.SOLUTION: This luminance increase film comprises a laminated body with a total thickness of 0.1-1.0 mm that consists of a core layer and a skin layer; (i) the core layer is formed from a polycarbonate resin layer; and (ii) the skin layer includes a carbonate unit (a unit A) represented by the following expression [1], formed of a modified polycarbonate resin layer whose ratio to the whole unit is 20-100 mol%, and the skin layer has a surface shape formed into a regularly disposed recessed/projecting shape.

Description

  The present invention relates to a brightness enhancement film comprising a polycarbonate resin laminate. More specifically, a modified polycarbonate resin layer derived from a specific bisphenol structural unit is laminated on the polycarbonate resin layer, and the surface of the laminate is shaped to have a concavo-convex shape, which has excellent transparency, transferability, scratch resistance, and deflection resistance. Concerning the rising film.

  A liquid crystal display device such as a liquid crystal television or a personal computer is generally composed of a liquid crystal panel, a reflective polarizing film, a brightness enhancement film, a diffusion film, a backlight unit, and a reflector. By incorporating the brightness increasing film on the front surface of the backlight unit, the light emitted from the light source can be condensed toward the display and the brightness on the front surface can be improved.

  Conventionally, the brightness enhancement film is mainly an optical film in which an acrylic resin having a prism shape is laminated on the surface of a polyester resin film. However, due to the recent increase in the size of liquid crystal display devices, problems such as warping and waviness due to the difference in shrinkage of each resin that makes up the brightness enhancement film occur. It is being considered. Further, as the liquid crystal display device is made thinner, the heat generated in the vicinity of the light source tends to cause the inside of the device to become high temperature, so that a polycarbonate resin having higher heat resistance is being used.

  However, the polycarbonate resin has a pencil hardness of only about 2B measured according to the coating material general test method described in JIS K5600-Part 5: Mechanical properties of the coating film-Section 4: Scratch hardness (pencil method). Since the surface is soft and easily damaged, there is a problem that scratches occur due to friction with other films (for example, a reflective polarizing film and a diffusion film), and the performance as a brightness enhancement film is deteriorated.

  As one method for improving the surface characteristics, a method of laminating an acrylic resin layer on a polycarbonate resin layer is known (for example, Patent Document 1). However, the acrylic resin has lower heat resistance than the polycarbonate resin and has a higher water absorption rate, so that the amount of dimensional change due to temperature and moisture absorption increases. Therefore, when a laminate having an acrylic resin layer on one side of a polycarbonate resin layer is exposed to high temperature and high humidity, the acrylic resin layer is warped due to deformation and adversely affects the processing process. There is. In addition, acrylic resin has a very hard pencil hardness of 3H compared to polycarbonate resin, so it does not scratch itself due to friction with other films (for example, reflective polarizing film or diffusion film), but damages other films. There is a problem that it ends up. Furthermore, since the refractive index of acrylic resin and polycarbonate resin is greatly different, the front brightness is reduced by reflection at the laminate resin interface. Further, when the laminate is pulverized and melted and kneaded with the polycarbonate resin again, the acrylic resin and the polycarbonate resin are incompatible with each other and thus become cloudy and have poor recyclability.

As another method for improving the surface characteristics, it is generally known that the surface of the polycarbonate resin layer is subjected to a hard coat treatment, but it is not preferable because it is inferior in recyclability after use.
Therefore, at present, there is no brightness enhancement film excellent in transparency, scratch resistance, deflection resistance, transferability, and recyclability.

JP 2007-160892 A

  An object of the present invention is to provide a brightness enhancement film comprising a polycarbonate resin laminate excellent in transparency, transferability, scratch resistance, deflection resistance, and recyclability.

According to the present invention, the above problem is
(Configuration 1): A brightness enhancement film comprising a laminate having a total thickness of 0.1 to 1.0 mm comprising a core layer and a skin layer, wherein (i) the core layer is formed of a polycarbonate resin layer, and (ii) ) The skin layer is composed of a modified polycarbonate resin layer containing a carbonate structural unit (structural unit A) represented by the following formula [1], the proportion of which is 20 to 100 mol% in all structural units, and the skin layer is This is solved by a brightness enhancement film which is a surface shape formed by irregularly arranged regularly arranged shapes.

（式中、Ｗは単結合、炭素原子数１〜６のアルキレン基、炭素原子数１〜６のアルキリデン基、炭素原子数６〜１０のアリーレン基、または炭素原子数３〜８の環状アルキレン基を表す。）

Wherein W is a single bond, an alkylene group having 1 to 6 carbon atoms, an alkylidene group having 1 to 6 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a cyclic alkylene group having 3 to 8 carbon atoms. Represents.)

One preferred aspect of the present invention is:
(Structure 2): The skin layer is composed of a carbonate structural unit represented by the above formula [1] (structural unit A) and a carbonate structural unit derived from 2,2-bis (4-hydroxyphenyl) propane (structural unit B). And the ratio of the structural unit A is 20 to 90 mol% of all the structural units.

One preferred aspect of the present invention is:
(Configuration 3): The brightness enhancement film according to Configuration 1, wherein the skin layer has a thickness of 5 to 100 μm.

One preferred aspect of the present invention is:
(Configuration 4): The modified polycarbonate resin forming the skin layer is
(1) Viscosity average molecular weight is 1.0 × 10 ^{4 to} 4.0 × 10 ⁴ ,
(2) The pencil hardness measured according to JIS K5600-5-4 is HB to 2H.
(3) The refractive index difference with the polycarbonate resin forming the core layer is within ± 0.01,
(4) Glass transition temperature is 120 ° C to 160 ° C,
(5) 300 ° C., a melt volume rate of 1.2kg load 20 cm ^3/10 minutes or more,
It is a brightness enhancement film of the said structure 1 which is.

One preferred aspect of the present invention is:
(Structure 5): The structural unit (A) of the modified polycarbonate resin forming the skin layer is 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methyl) The brightness enhancement film according to the above constitution 1, which is a constitutional unit derived from at least one selected from the group consisting of (phenyl) propane and 2,2′-methyl-4,4′-biphenyldiol.

One preferred aspect of the present invention is:
(Structure 6): The luminance according to structure 1, wherein the structural unit (A) of the modified polycarbonate resin forming the skin layer is a structural unit derived from 2,2-bis (4-hydroxy-3-methylphenyl) propane. It is a rising film.

One preferred aspect of the present invention is:
(Structure 7): The luminance according to structure 1, wherein the structural unit (A) of the modified polycarbonate resin forming the skin layer is a structural unit derived from 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane. It is a rising film.

One preferred aspect of the present invention is:
(Arrangement 8): The irregularly arranged irregular shape is at least one selected from the group consisting of a lenticular type, a prism type, and a linear Fresnel type shape having a pitch of 10 to 300 μm and a height of 10 to 300 μm. The brightness enhancement film according to Configuration 1.

  The brightness enhancement film comprising the polycarbonate resin laminate of the present invention is excellent in transparency, scratch resistance, deflection resistance, transferability, and recyclability, so that it can be used as a brightness enhancement film for thin and large liquid crystal display devices. Is possible. Therefore, the industrial effects that it plays are exceptional.

It is a figure which shows the measuring method of curvature amount. It is the figure which expanded the shaping surface vicinity. It is the figure which showed the one aspect | mode of the manufacturing apparatus of a polycarbonate resin laminated body. It is the figure which showed the one aspect | mode of the manufacturing apparatus of a shaping polycarbonate resin laminated body.

Hereinafter, the present invention will be described in detail.
(Core layer)
In the present invention, the core layer is formed from a polycarbonate resin layer.

<Polycarbonate resin>
The polycarbonate resin used in the polycarbonate resin layer of the present invention is obtained by reacting a dihydric phenol and a carbonate precursor. Examples of the reaction method include an interfacial polycondensation method, a melt transesterification method, a solid phase transesterification method of a carbonate prepolymer, and a ring-opening polymerization method of a cyclic carbonate compound. The polycarbonate resin may be produced by any production method, and in the case of interfacial polycondensation, a terminal stopper of a monohydric phenol is usually used. The polycarbonate resin may be a branched polycarbonate obtained by polymerizing a trifunctional or higher polyfunctional component in addition to the dihydric phenol or difunctional alcohol. Further, it may be a branched polycarbonate resin obtained by polymerizing polyfunctional phenols such as trifunctional phenols, and further, an aliphatic dicarboxylic acid or aromatic dicarboxylic acid, a polyorganosiloxane component, and a vinyl monomer may be copolymerized. Copolymer polycarbonate may also be used. Representative examples of dihydric phenols include 2,2-bis (4-hydroxyphenyl) propane (commonly known as bisphenol A), 1,1-bis (4-hydroxyphenyl) ethane, and 1,1-bis (4-hydroxyphenyl). ) Cyclohexane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, bis (4-hydroxyphenyl) sulfide, Examples thereof include bis (4-hydroxyphenyl) sulfone. A preferred dihydric phenol is a bis (4-hydroxyphenyl) alkane series, and bisphenol A is particularly preferred.

  In a reaction using, for example, phosgene as a carbonate precursor, the reaction is usually performed in the presence of an acid binder and a solvent. As the acid binder, for example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide or an amine compound such as pyridine is used. As the solvent, for example, halogenated hydrocarbons such as methylene chloride and chlorobenzene are used. In order to accelerate the reaction, a catalyst such as a tertiary amine or a quaternary ammonium salt can also be used. In that case, reaction temperature is 0-40 degreeC normally, and reaction time is several minutes-5 hours.

  For example, a transesterification reaction using a carbonic acid diester as a carbonate precursor is carried out by a method in which an aromatic dihydroxy component in a predetermined ratio is stirred with a carbonic acid diester while heating in an inert gas atmosphere to distill the resulting alcohol or phenol. Is called. The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, but is usually in the range of 120 to 300 ° C. The reaction is completed while distilling off the alcohol or phenol produced under reduced pressure from the beginning. Moreover, in order to accelerate | stimulate reaction, the catalyst normally used for transesterification can also be used. Examples of the carbonic acid diester used in the transesterification include diphenyl carbonate, dinaphthyl carbonate, bis (diphenyl) carbonate, dimethyl carbonate, diethyl carbonate, and dibutyl carbonate. Of these, diphenyl carbonate is particularly preferred.

  Monofunctional phenols usually used as a terminal terminator can be used. Particularly in the case of a reaction using phosgene as a carbonate precursor, monofunctional phenols are generally used as a terminator for controlling the molecular weight, and the resulting aromatic polycarbonate resin has a terminal monofunctional phenol. Since it is blocked by a group based on, it is superior in thermal stability as compared to those not. Such monofunctional phenols may be used as long as they are used as an end stopper for aromatic polycarbonate resins. Specific examples of the monofunctional phenols include phenol, p-tert-butylphenol, and p-cumyl. Phenol and isooctylphenol are mentioned.

  In producing the polycarbonate resin, the above dihydric phenols can be used alone or in combination of two or more thereof, and a molecular weight regulator, a branching agent, a catalyst and the like can be used as necessary.

The molecular weight of the polycarbonate resin is preferably 1.0 × 10 ^{4 to} 4.0 × 10 ⁴ in terms of viscosity average molecular weight, more preferably 1.3 × 10 ^{4 to} 3.0 × 10 ⁴ , and still more preferably. Is 1.4 × 10 ^{4 to} 2.0 × 10 ⁴ . The viscosity average molecular weight referred to in the present invention is obtained by inserting the specific viscosity (η _sp ) obtained from a solution obtained by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20 ° C. into the following equation.
η _sp /c=[η]+0.45×[η] ² c (where [η] is the intrinsic viscosity)
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
c = 0.7
The polycarbonate resin of the present invention can contain functional agents known per se such as a mold release agent, a heat stabilizer, and a flow modifier as long as the effects of the present invention are not impaired.

(Skin layer)
In the present invention, the skin layer is formed from a modified polycarbonate resin layer.

<Modified polycarbonate resin>
The modified polycarbonate resin in the present invention contains a carbonate structural unit (structural unit A) represented by the above formula [1], and the proportion thereof is 20 to 100 mol% in all structural units. It has been found that by using a modified polycarbonate resin containing such a structural unit A in a specific ratio or more, it is possible to develop higher scratch resistance than conventional polycarbonate resins. In particular, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane and 2,2′-methyl-4,4′-biphenyldiol It is preferably a structural unit derived from at least one selected from the group consisting of 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane or 2,2-bis (4-hydroxy-3-). It is preferably a structural unit derived from methylphenyl) propane.

  Further, the proportion of the structural unit A is preferably 30 mol% or more, more preferably 40 mol% or more in all the structural units. If the proportion of the structural unit A is less than 20 mol%, the scratch resistance is insufficient, which is not preferable.

  Furthermore, as a modified polycarbonate resin, from a carbonate structural unit (structural unit A) represented by the above formula [1] and a carbonate structural unit derived from 2,2-bis (4-hydroxyphenyl) propane (structural unit B). Thus, a modified polycarbonate resin in which the proportion of the structural unit A is 20 to 90 mol% in all the structural units is preferably used. The proportion of the structural unit A is more preferably 30 to 80 mol%, and even more preferably 40 to 70 mol% in all the structural units.

For the production of the modified polycarbonate resin, the same technique as that for the polycarbonate resin can be used.
The molecular weight of the modified polycarbonate resin is preferably 1.0 × 10 ^{4 to} 4.0 × 10 ⁴ , more preferably 1.3 × 10 ^{4 to} 3.0 × 10 ⁴ in terms of viscosity average molecular weight, preferably ^{1.4 × 10 4 ~2.0 × 10 4} .

  The pencil hardness of the modified polycarbonate resin is preferably HB to 2H, more preferably F to H. When the pencil hardness is less than the lower limit of the range, the scratch resistance is insufficient, and when the pencil hardness exceeds the upper limit of the range, the film itself is not damaged by the friction with the other film constituting the liquid crystal display device, but the other film is damaged. Therefore, it is not preferable. The pencil hardness referred to in the present invention is a three-stage plate formed by injection molding (width 50 mm, length 90 mm, thickness is 3.0 mm (length 20 mm), 2.0 mm (length 45 mm) from the gate side, 1 It was measured in accordance with the method described in JIS K5600-5-4 at a thickness of 2.0 mm with a thickness of 0.0 mm (length 25 mm) and arithmetic average roughness (Ra): 0.03 μm.

  The refractive index difference between the modified polycarbonate resin forming the skin layer and the polycarbonate resin forming the core layer is preferably -0.01 to +0.01, more preferably -0.008 to +0.008. If the refractive index difference is larger than the above described range, it is not preferable because the front luminance is reduced by reflection at the resin interface of the laminate. The refractive index referred to in the present invention is a wavelength of 589 nm (D) using an Abbe refractometer having a wavelength selection filter as a light source in accordance with JIS-K7142 by cutting a 1.0 mm thickness portion of the above-described three-stage plate. The refractive index measured by (line) indicates a refractive index difference obtained by subtracting the refractive index of the polycarbonate resin from the refractive index of the modified polycarbonate resin.

  The modified polycarbonate resin preferably has a glass transition temperature (Tg) of 120 to 160 ° C, and more preferably 130 to 150 ° C. When the Tg is less than the lower limit of the above range, the heat resistance is insufficient, and the brightness enhancement film is warped by thermal deformation, which is not preferable. If Tg exceeds the upper limit of the above range, it is not preferable because the transferability of the concavo-convex shape is inferior at the time of shaping. Tg in the present invention is obtained by using a differential scanning calorimeter (DSC) and measuring at a heating rate of 20 ° C./min in accordance with JIS K7121.

Modified polycarbonate resin is preferably a melt volume Le flow rate (MVR) is 20 cm ^3/10 minutes or more, more preferably 30 cm ^3/10 minutes or more. The upper limit is not particularly limited, has sufficient transferability equal to or less than 100 cm ^3/10 min. If the MVR is less than the lower limit of the above range, transferability of the surface shaped shape is inferior, which is not preferable. The MVR in the present invention is measured at 300 ° C. and 1.2 kg load according to the method described in ISO 1133.
The modified polycarbonate resin of the present invention may contain functional agents known per se such as a mold release agent, a heat stabilizer, and a flow modifier as long as the effects of the present invention are not impaired.

<Ingredients other than resin>
The polycarbonate resin and modified polycarbonate resin of the present invention are more preferably blended with the following release agent, heat stabilizer and the like.

(I) Release agent It is preferable to mix a release agent with the polycarbonate resin and modified polycarbonate resin used in the present invention.
Known release agents can be used as the release agent of the present invention. For example, fatty acid ester, polyolefin wax (polyethylene wax, 1-alkene polymer, etc., which may be modified with a functional group-containing compound such as acid modification), silicone compound, fluorine compound (represented by polyfluoroalkyl ether) Fluorinated oil), paraffin wax, beeswax and the like. Of these, fatty acid esters are preferred from the standpoints of availability, releasability and transparency. Such a release agent is preferably 0.005 to 0.3 parts by weight, more preferably 0.007 to 0.2 parts by weight with respect to 100 parts by weight of the resin. When the addition amount is less than the lower limit of the above range, the releasability is not sufficiently improved. When the addition amount exceeds the upper limit, transferability is deteriorated due to contamination of a shaping apparatus such as a roll, a mold or a stamper, or bleed out.

  Among the above, fatty acid ester is mentioned as a preferable release agent. Such fatty acid esters are esters of aliphatic alcohols and aliphatic carboxylic acids. Such an aliphatic alcohol may be a monohydric alcohol or a dihydric or higher polyhydric alcohol. Moreover, as carbon number of this alcohol, it is the range of 3-32 suitably, More preferably, it is the range of 5-30. Examples of such monohydric alcohols include dodecanol, tetradecanol, hexadecanol, octadecanol, eicosanol, tetracosanol, seryl alcohol, and triacontanol. Examples of such polyhydric alcohols include pentaerythritol, dipentaerythritol, tripentaerythritol, polyglycerol (triglycerol to hexaglycerol), ditrimethylolpropane, xylitol, sorbitol, and mannitol. In the fatty acid ester of the present invention, a polyhydric alcohol is more preferable.

  On the other hand, the aliphatic carboxylic acid preferably has 3 to 32 carbon atoms, and particularly preferably an aliphatic carboxylic acid having 10 to 22 carbon atoms. Examples of the aliphatic carboxylic acid include decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid, octadecanoic acid (stearic acid), nonadecanoic acid, icosanoic acid, And saturated aliphatic carboxylic acids such as docosanoic acid (behenic acid) and unsaturated aliphatic carboxylic acids such as palmitoleic acid, oleic acid, linoleic acid, linolenic acid, eicosenoic acid, eicosapentaenoic acid, and cetreic acid it can. Among the above, aliphatic carboxylic acids having 14 to 20 carbon atoms are preferable. Of these, saturated aliphatic carboxylic acids are preferred. Such aliphatic carboxylic acids are usually produced from natural fats and oils such as animal fats (such as beef tallow and pork fat) and vegetable fats and oils (such as palm oil). Of other carboxylic acid components. Therefore, in the production of the aliphatic carboxylic acid used in the present invention, it is produced from such natural fats and oils and is in the form of a mixture containing other carboxylic acid components. The acid value in the fatty acid ester is preferably 20 or less (can take substantially 0). However, in the case of all esters (full esters), it is preferable to contain at least free fatty acids in order to improve releasability. In this respect, the acid value in the full esters is preferably in the range of 3 to 15. The iodine value of the fatty acid ester is preferably 10 or less (can take substantially 0). These characteristics can be obtained by a method defined in JIS K 0070.

  The fatty acid ester of the present invention may be either a partial ester or a full ester. In the present invention, a partial ester is more preferable in terms of good releasability and durability. Of these, glycerin monoester is preferred. Glycerin monoester is mainly composed of monoester of glycerin and fatty acid. Suitable fatty acids include saturated fatty acids such as stearic acid, palmitic acid, behenic acid, arachidic acid, montanic acid, lauric acid, oleic acid, and linoleic acid. And unsaturated fatty acids such as sorbic acid, and those having glycerin monoesters of stearic acid, behenic acid, and palmitic acid as main components are particularly preferred. Such fatty acids are synthesized from natural fatty acids and become a mixture as described above. The glycerin monoester can be used in combination with other release agents, particularly fatty acid full esters, but even when used in combination, it is preferable that the glycerin monoester is the main component. That is, it is preferably 60% by weight or more in 100% by weight of the release agent.

  In addition, partial esters are often inferior to full esters in terms of thermal stability. In order to improve the thermal stability of such a partial ester, the partial ester preferably has a sodium metal content of less than 20 ppm, more preferably less than 5 ppm, and even more preferably less than 1 ppm. The fatty acid partial ester having a sodium metal content of less than 1 ppm can be produced by producing the fatty acid partial ester by an ordinary method and then purifying it by molecular distillation or the like.

  Specifically, after removing gas components and low-boiling substances with a spray nozzle type degassing apparatus, glycerin is used under the conditions of a distillation temperature of 120 to 150 ° C. and a vacuum degree of 0.01 to 0.03 kPa using a falling film distillation apparatus. For example, a high molecular weight fatty acid ester is distilled off using a centrifugal molecular distillation apparatus at a distillation temperature of 160 to 230 ° C. and a vacuum of 0.01 to 0.2 Torr. The sodium metal can be removed as a distillation residue. By subjecting the resulting distillate to repeated molecular distillation, it is possible to further increase the purity and obtain a fatty acid partial ester having a lower sodium metal content. It is also important to prevent the contamination of the sodium metal component from the external environment by thoroughly washing the inside of the molecular distillation apparatus by an appropriate method in advance and improving airtightness. Such a fatty acid ester is available from a specialist (for example, Riken Vitamin Co., Ltd.).

(Ii) Phosphorous stabilizer It is preferable that various phosphorous stabilizers are further blended in the polycarbonate resin and modified polycarbonate resin of the present invention mainly for the purpose of improving thermal stability during processing. Examples of such phosphorus stabilizers include phosphorous acid, phosphoric acid, phosphonous acid, phosphonic acid, and esters thereof. In addition, such phosphorus stabilizers include tertiary phosphines.

  Specifically, as the phosphite compound, for example, triphenyl phosphite, tris (nonylphenyl) phosphite, tridecyl phosphite, trioctyl phosphite, trioctadecyl phosphite, didecyl monophenyl phosphite, dioctyl monophenyl Phosphite, diisopropyl monophenyl phosphite, monobutyl diphenyl phosphite, monodecyl diphenyl phosphite, monooctyl diphenyl phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, tris ( Diethylphenyl) phosphite, tris (di-iso-propylphenyl) phosphite, tris (di-n-butylphenyl) phosphite, tris (2,4-di-tert-butylpheny) ) Phosphite, tris (2,6-di-tert-butylphenyl) phosphite, distearyl pentaerythritol diphosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2 , 6-Di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,6-di-tert-butyl-4-ethylphenyl) pentaerythritol diphosphite, phenylbisphenol A pentaerythritol diphosphite Phyto, bis (nonylphenyl) pentaerythritol diphosphite, dicyclohexyl pentaerythritol diphosphite, and the like.

  Further, as other phosphite compounds, those which react with dihydric phenols and have a cyclic structure can be used. For example, 2,2′-methylenebis (4,6-di-tert-butylphenyl) (2,4-di-tert-butylphenyl) phosphite, 2,2′-methylenebis (4,6-di-tert- Butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite, 2,2′-methylenebis (4-methyl-6-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite 2,2′-ethylidenebis (4-methyl-6-tert-butylphenyl) (2-tert-butyl-4-methylphenyl) phosphite.

  Examples of the phosphate compound include tributyl phosphate, trimethyl phosphate, tricresyl phosphate, triphenyl phosphate, trichlorophenyl phosphate, triethyl phosphate, diphenyl cresyl phosphate, diphenyl monoorxenyl phosphate, tributoxyethyl phosphate, dibutyl phosphate, dioctyl phosphate, Examples thereof include diisopropyl phosphate, and triphenyl phosphate and trimethyl phosphate are preferable.

  Examples of the phosphonite compound include tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite, tetrakis (2,4-di-tert-butylphenyl) -4,3′-biphenylenedi. Phosphonite, tetrakis (2,4-di-tert-butylphenyl) -3,3′-biphenylenediphosphonite, tetrakis (2,6-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite Tetrakis (2,6-di-tert-butylphenyl) -4,3′-biphenylene diphosphonite, tetrakis (2,6-di-tert-butylphenyl) -3,3′-biphenylene diphosphonite, bis (2,4-di-tert-butylphenyl) -4-phenyl-phenylphosphonite, bis (2,4-di tert-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-n-butylphenyl) -3-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl)- 4-phenyl-phenylphosphonite, bis (2,6-di-tert-butylphenyl) -3-phenyl-phenylphosphonite, and the like, and tetrakis (di-tert-butylphenyl) -biphenylenediphosphonite, bis (Di-tert-butylphenyl) -phenyl-phenylphosphonite is preferred, tetrakis (2,4-di-tert-butylphenyl) -biphenylenediphosphonite, bis (2,4-di-tert-butylphenyl)- More preferred is phenyl-phenylphosphonite. Such a phosphonite compound is preferable because it can be used in combination with a phosphite compound having an aryl group in which two or more alkyl groups are substituted.

  Examples of the phosphonate compound include dimethyl benzenephosphonate, diethyl benzenephosphonate, and dipropyl benzenephosphonate.

  Tertiary phosphine includes triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triamylphosphine, dimethylphenylphosphine, dibutylphenylphosphine, diphenylmethylphosphine, diphenyloctylphosphine, triphenylphosphine, tri-p-tolyl. Examples include phosphine, trinaphthylphosphine, and diphenylbenzylphosphine. A particularly preferred tertiary phosphine is triphenylphosphine.

  The phosphorus stabilizer can be used not only in one kind but also in a mixture of two or more kinds. Among the phosphorus stabilizers, phosphite compounds or phosphonite compounds are preferable. In particular, tris (2,4-di-tert-butylphenyl) phosphite, tetrakis (2,4-di-tert-butylphenyl) -4,4′-biphenylenediphosphonite and bis (2,4-di-) tert-Butylphenyl) -phenyl-phenylphosphonite is preferred. A combination of these and a phosphate compound is also a preferred embodiment.

(Iii) Hindered phenol stabilizer The polycarbonate resin of the present invention and the modified polycarbonate resin are blended with a hindered phenol stabilizer mainly for the purpose of improving the heat stability during processing and heat aging resistance. can do. Examples of such hindered phenol stabilizers include α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-tert-butylfel). ) Propionate, 2-tert-butyl-6- (3′-tert-butyl-5′-methyl-2′-hydroxybenzyl) -4-methylphenyl acrylate, 2,6-di-tert-butyl-4- ( N, N-dimethylaminomethyl) phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2 ′ -Methylenebis (4-ethyl-6-tert-butylphenol), 4,4'-methylenebis (2 , 6-di-tert-butylphenol), 2,2′-methylenebis (4-methyl-6-cyclohexylphenol), 2,2′-dimethylene-bis (6-α-methyl-benzyl-p-cresol) 2, 2′-ethylidene-bis (4,6-di-tert-butylphenol), 2,2′-butylidene-bis (4-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6) -Tert-butylphenol), triethylene glycol-N-bis-3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate, 1,6-hexanediol bis [3- (3,5- Di-tert-butyl-4-hydroxyphenyl) propionate], bis [2-tert-butyl-4-methyl 6- (3-tert- Butyl-5-methyl-2-hydroxybenzyl) phenyl] terephthalate, 3,9-bis {2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1, -Dimethylethyl} -2,4,8,10-tetraoxaspiro [5,5] undecane, 4,4'-thiobis (6-tert-butyl-m-cresol), 4,4'-thiobis (3- Methyl-6-tert-butylphenol), 2,2′-thiobis (4-methyl-6-tert-butylphenol), bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4,4 ′ -Di-thiobis (2,6-di-tert-butylphenol), 4,4'-tri-thiobis (2,6-di-tert-butylphenol), 2,2-thio Ethylenebis- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-hydroxy-3 ′, 5′-di -Tert-butylanilino) -1,3,5-triazine, N, N'-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydrocinnamide), N, N'-bis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,3 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxyphenyl) Isocyanurate, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate 1,3,5-tris 2 [3 (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl isocyanurate and tetrakis [methylene-3- (3 ′, 5′-di- tert-butyl-4-hydroxyphenyl) propionate] methane and the like. All of these are readily available. The said hindered phenolic antioxidant can be used individually or in combination of 2 or more types.

  The amount of the above (ii) phosphorus stabilizer and (iii) hindered phenol antioxidant is preferably 0.0001 to 1 part by weight, more preferably 0.001 to 0 parts per 100 parts by weight of the polycarbonate resin. 0.1 part by weight, more preferably 0.005 to 0.1 part by weight. If the stabilizer is less than the above range, it is difficult to obtain a good stabilizing effect. If the stabilizer exceeds the above range, the physical properties of the material are deteriorated, and rolls, molds, stampers, etc. May cause contamination.

  For the polycarbonate resin and modified polycarbonate resin of the present invention, an antioxidant other than the hindered phenol antioxidant can be used as appropriate. Examples of such other antioxidants include pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-lauryl thiopropionate), and glycerol-3-stearyl thiopropionate. The amount of these other antioxidants used is preferably 0.001 to 0.05 parts by weight with respect to 100 parts by weight of the polycarbonate resin.

(Iv) Antistatic agent An antistatic agent can be blended in the polycarbonate resin and modified polycarbonate resin of the present invention mainly for the purpose of improving antistatic properties. As the antistatic agent, sulfonic acid phosphonium salts, phosphite esters, caprolactone-based polymers, and the like can be used, and sulfonic acid phosphonium salts are preferably used. Specific examples of such phosphonium sulfonates include tetrabutylphosphonium dodecylsulfonate, tetrabutylphosphonium dodecylbenzenesulfonate, tributyloctylphosphonium dodecylbenzenesulfonate, tetraoctylphosphonium dodecylbenzenesulfonate, tetraethylphosphonium octadecylbenzenesulfonate, dibutyl Examples thereof include tributylmethylphosphonium benzenesulfonate, triphenylphosphonium dibutylnaphthylsulfonate, and trioctylmethylphosphonium diisopropylnaphthylsulfonate. Of these, tetrabutylphosphonium dodecylbenzenesulfonate is preferred because it is compatible with polycarbonate and easily available. The amount of the antistatic agent is 0.1 to 5.0 parts by weight based on 100 parts by weight of the polycarbonate resin, preferably 0.2 to 3.0 parts by weight, and more preferably 0.3 to 2. 0 parts by weight, particularly preferably 0.5 to 1.8 parts by weight. If the amount is less than 0.1 parts by weight, the antistatic effect cannot be obtained. If the amount exceeds 5.0 parts by weight, the transparency and mechanical strength are lowered, and silver or peeling occurs on the surface of the molded product, which easily causes poor appearance. .

  In addition, the polycarbonate resin and modified polycarbonate resin of the present invention can contain a flame retardant. These can contain the agent and compounding quantity which do not have a trouble as a brightness enhancement film, selecting suitably.

<Brightness enhancement film (laminate)>
The brightness enhancement film of the present invention is a laminate having a total thickness of 0.1 to 1.0 mm composed of a core layer and a skin layer, and is a laminate formed with irregularities regularly arranged on the surface of the skin layer. Is the body.
In the laminate, the core layer may be a polycarbonate resin layer and the skin layer may be a modified polycarbonate resin layer, and the skin layer may be on one or both surfaces of the core layer surface. The thickness of the skin layer is preferably 5 to 100 μm, more preferably 50 μm or less, and further preferably 30 μm or less. If the skin layer is less than the lower limit of the range, the scratch resistance is insufficient, and if it exceeds the upper limit of the range, spots are generated when the skin layer is laminated, which is not preferable. The thickness of the skin layer is determined by precisely cutting the resin film with a microtome, or by uniformly dividing the resin film solidified with liquid nitrogen to create a cut surface, and using a scanning electron microscope, the resin film from the interface between the skin layer and the core layer The distance to the surface is calculated as the skin layer thickness.

The production method of the polycarbonate resin layer is not particularly limited, and examples thereof include a melt extrusion method and a solution casting method (casting method). A specific method of the melt extrusion method is, for example, that a polycarbonate resin is quantitatively supplied to an extruder, heated and melted, and the molten resin is extruded in a film form on a mirror surface roll from the tip of a T die, and a plurality of rolls A method is used in which it is taken up while being cooled and cut or wound into an appropriate size when solidified. A specific method of the solution casting method is, for example, casting a solution of polycarbonate resin in methylene chloride (concentration 5% to 40%) from a T-die onto a mirror-polished stainless steel plate, and controlling the temperature stepwise. The film is peeled off while passing through the oven, the solvent is removed, and the film is cooled and wound.
The production method of the modified polycarbonate resin layer is not particularly limited, and for example, the same production method as that of the polycarbonate resin layer can be used.

An arbitrary method may be used as a method for producing the polycarbonate resin laminate, and it is particularly preferable to carry out by a thermocompression bonding method or a coextrusion method. Any method can be adopted as the thermocompression bonding method. For example, a method of thermocompression bonding a polycarbonate resin film and a modified polycarbonate resin film with a laminating machine or a press, a thermocompression bonding of the modified polycarbonate resin film to the polycarbonate resin film immediately after extrusion. The method is preferred, and in particular, the method of continuously thermocompression bonding to a polycarbonate resin film immediately after extrusion is industrially advantageous. The thermocompression bonding conditions in this case vary depending on the thickness of the polycarbonate resin film or the modified polycarbonate resin film, the state of the crimping surface, etc., and cannot be specified in general, but the temperature near or above the glass transition point of the modified polycarbonate resin film, usually Glass transition point of modified polycarbonate resin film −10 ° C. to glass transition point + 150 ° C., preferably about 0.05 to 5 kg / cm ² , preferably 0.1 to 1 kg at glass transition point −5 ° C. to glass transition point + 100 ° C. Thermocompression bonding is possible by applying a pressure of about / cm ² . At that time, as a method of forming a regular concavo-convex shape on the surface, a method of hot press molding a heat-bonded film using a stamper having a concavo-convex shape, the concavo-convex shape is formed during thermocompression bonding. A method of pressing the engraved roll is used.

  In the coextrusion method, the modified polycarbonate resin is melt-extruded at a glass transition point to a glass transition point + 230 ° C., preferably at a glass transition point + 50 ° C. to a glass transition point + 200 ° C. with an auxiliary melt extruder, and polycarbonate is used with a main melt extruder. The resin can be melt-extruded at its glass transition point to glass transition point + 230 ° C., preferably glass transition point + 50 ° C. to glass transition point + 200 ° C., and extrusion laminated by a known method such as a multi-manifold method or a feed block method. The melt extruder may be a single screw extruder or a twin screw extruder. In order to prevent thermal deterioration of resin, coloring, prevention of T-die lip, and roll contamination, vacuum degassing by vent suction, suction degassing in hopper, and hopper or barrel of inert gas such as nitrogen Infusion can be performed. In the case of vent suction, the pressure is preferably reduced at 1.33 to 66.5 kPa.

  The film extruded in the molten state is cooled while being nipped by the first roll, the second roll, and the third roll. At this time, the film is given a fine uneven shape by the engraving grooves formed on the surface of the second roll, cooled, and then taken up by the take-up roll. The roll diameters of the first to third rolls used here do not need to be particularly restricted and need not be unified to the same roll diameter, but the roll diameter is usually 200 mm or more, and particularly the same diameter of 250 to 500 mm. Are preferably used. Any of the rolls may be subjected to various coating treatments including a resin coat on the roll surface. The pitch of the engraving groove of the engraving groove roll to be used is preferably 10 to 300 μm, more preferably 20 to 100 μm. The pitch of the convex shape in the shaped film depends on the pitch of the engraving grooves of the roll. It is desirable that the convex shapes in the present invention have the same pitch. Therefore, the pitch of the engraving grooves is a constant value, and as a result, a film in which fine irregularities are regularly arranged at the same pitch is desirable. Basically, the pitch value is appropriately determined in the required optical design. However, in the range of 10 to 300 μm, the film brightness enhancement, productivity, and roll engraving productivity are excellent.

  The groove depth of the engraving groove roll used in the present invention is preferably 10 to 300 μm. Such a lower limit is more preferably 20 μm, still more preferably 100 μm. On the other hand, the upper limit is preferably 300 μm, more preferably 200 μm. The groove depth of the roll is designed in consideration of the transfer rate to the film, and can be engraved using a known engraving machine. The linear pressure when the melt-extruded polycarbonate resin composition is sandwiched between the first roll and the second roll and pressed by the two rolls is preferably 50 kg / cm or more. More preferably, it is the range of 100-200 kg / cm. If it exceeds 200 kg / cm, the film tends to be distorted on the front surface in the thickness direction due to crushing, causing curling and warping of the film, and also causing the roll axis to be distorted due to pressure. It causes a difference.

  The laminate of the present invention is a concavo-convex shape in which the surface-shaped concavo-convex shape is regularly arranged in the width direction of the film or / and the direction perpendicular to the width direction, and the concavo-convex shape is preferably a lens shape, and more preferably For this, a lenticular type, a prism type, or a linear Fresnel type lens is preferable. Here, “the width direction of the film or / and the direction perpendicular to the width direction” means that the uneven shape is regularly arranged on one side in the width direction of the film or the direction perpendicular to the width direction, and the uneven shape is on one side. Includes the regular arrangement in the width direction of the film and in the direction perpendicular to the width direction on the other surface. The concavo-convex shape of the present invention includes both modes of single-sided shaping and double-sided shaping. The uneven shape of the present invention is preferably a shape having a lens function that requires higher accuracy. The concave / convex shape of the lens function includes a lens array including a so-called fly-eye lens, but more preferably a bowl-shaped lens shape, and a prism type is particularly preferable.

  As transparency of the laminated body of this invention, it evaluates by the total light transmittance value and haze value based on JISK7361-1 and JISK7136. The total light transmittance value of the resin laminate obtained in the present invention is preferably 85% or more, and more preferably 90% or more. Further, the haze value is preferably 1.0% or less, and more preferably 0.5% or less.

  The pencil hardness of the laminate of the present invention is preferably HB to 2H, more preferably F to H. When the pencil hardness is less than the lower limit of the range, the scratch resistance is insufficient, and when the pencil hardness exceeds the upper limit of the range, the film itself is not damaged by the friction with the other film constituting the liquid crystal display device, but the other film is damaged. Therefore, it is not preferable. The pencil hardness referred to in the present invention is a three-stage plate formed by injection molding (width 50 mm, length 90 mm, thickness is 3.0 mm (length 20 mm), 2.0 mm (length 45 mm) from the gate side, 1 It was measured in accordance with the method described in JIS K5600-5-4 at a thickness of 2.0 mm with a thickness of 0.0 mm (length 25 mm) and arithmetic average roughness (Ra): 0.03 μm.

  The bending resistance of the laminate of the present invention is the amount of warpage after cutting into a length of 80 mm and a width of 25 mm and treating in a 60 ° C., 90% RH atmosphere for 96 hours, preferably 500 μm or less, more preferably It is 300 μm or less, and 100 μm or less is particularly preferable. When the warpage exceeds the upper limit of the above range, it is not preferable because the film bends to cause a circular shape change, resulting in uneven brightness.

  In the laminate of the present invention, the transfer rate of the surface-shaped concavo-convex shape is preferably 90% or more, and more preferably 95% or more. In addition, it is preferable that deformation and warping at the time of mold release be as small as possible.

  Hereinafter, although an example is given and explained in detail, the present invention is not limited to this unless it exceeds the purpose. In addition, the performance evaluation in an Example and a comparative example followed the following method.

(1) Viscosity average molecular weight The viscosity average molecular weight of the modified polycarbonate resin and polycarbonate resin (L-1225LM) was determined from an Ostwald viscometer from a solution in which 0.7 g of polycarbonate resin was dissolved in 100 ml of methylene chloride at a specific viscosity (η _SP ) of 20 ° C. The viscosity average molecular weight Mv was calculated from the specific viscosity (η _SP ) by the following formula.
Specific viscosity (η _SP ) = (t−t ₀ ) / t ₀
[T ₀ is methylene chloride falling seconds, t is sample solution falling seconds]
η _SP /c=[η]+0.45×[η] ² c (where [η] is the intrinsic viscosity)
[Η] = 1.23 × 10 ⁻⁴ Mv ^0.83
c = 0.7

(2) Pencil hardness The pencil hardness of the modified polycarbonate resin and the laminate was measured by the following method. Using a mold having a cavity surface with an arithmetic average roughness (Ra) of 0.03 μm, using an injection molding machine J-75E3 manufactured by Nippon Steel Works under conditions of a cylinder temperature of 280 ° C. and a mold temperature of 80 ° C. A three-stage type having a width of 50 mm, a length of 90 mm, and a thickness of 3 mm (length: 20 mm), 2 mm (length: 45 mm), and 1 mm (length: 25 mm) with a holding pressure of 20 seconds and a cooling time of 20 seconds. Plates were molded. The pencil hardness at a thickness of 2 mm of the three-stage plate was measured according to JIS K5600.

(3) Refractive index The refractive index of the modified polycarbonate resin and polycarbonate resin (L-1225LM) is cut at a 1.0 mm thickness of the three-stage plate, and the light source has a wavelength selection filter in accordance with JIS-K7142. The refractive index at a wavelength of 589 nm (D line) was measured using an Abbe refractometer.

(4) Glass transition temperature The glass transition temperature of the modified polycarbonate resin was measured using a thermal analysis system DSC-2910 manufactured by TA Instruments, under a nitrogen atmosphere (nitrogen flow rate: 40 ml / min) in accordance with JISK7121, and the rate of temperature increase: The measurement was performed under the condition of 20 ° C./min.

(5) Melt Volume Flow Rate The melt volume flow rate (MVR) of the modified polycarbonate resin was measured according to the method described in ISO 1133 at 300 ° C. and 1.2 kg load.

(6) Total thickness The total thickness of the laminate and the shaped laminate was measured using a continuous thickness meter (Anritsu Co., Ltd. film thickness tester, model KG601A).

(7) Skin layer thickness The laminate and the shaped laminate were cut with a microtome, the cut surface was observed with a Hitachi scanning electron microscope S-3400N, and the skin layer thickness was measured.

(8) Transparency The total light transmittance value and haze value of the laminate were measured according to JIS K 7361-1 and JIS K 7136.

(9) Scratch resistance The laminate was measured for pencil hardness in accordance with JIS K 5600.

(10) Deflection Resistance The amount of warpage after the laminate was cut into a length of 80 mm and a width of 25 mm and treated in an atmosphere of 60 ° C. and 90% RH for 96 hours was measured by the method shown in FIG.

(11) Brightness increasing property The total light transmittance value was measured based on JIS K 7361-1 using the shaped laminate. At that time, measurement was performed with the shaping surface opposite to the light source side, and an increase in total light transmittance was confirmed.

(12) Transferability The shaped laminate was cut with a microtome, and the cut surface was observed with a Hitachi scanning electron microscope S-3400N to measure the pitch and height of the shaped shape. The pitch and height of the shaped shape were measured at the positions shown in FIG. FIG. 2 is an enlarged view of the vicinity of the shaping surface.

(13) Recyclability The shaped laminate is pulverized with a pulverizer, and 5 parts by weight of the pulverized product is mixed with polycarbonate resin (Teijin Kasei Panlite (registered trademark) L-1225WP: 95 parts by weight), uniformly The premix was fed to the first inlet at the end using a vented twin screw extruder (KZW15-25MG manufactured by Technovel Corp.) with a screw diameter of 15 mm. The temperature and the die temperature were 280 ° C., the screw rotation speed was 200 rpm, the discharge rate was 2 kg / hour, and the vent vacuum was 3 kPa The obtained resin composition pellets were heated at 120 ° C. for 6 hours with hot air. After drying with a dryer, cylinder temperature 230 ° C, mold temperature 90 ° C, molding cycle by injection molding machine (J75EIII type, manufactured by Nippon Steel) Molded in 40 seconds, an impact test piece (size: length 80 mm × width 10 mm × thickness 4 mm) was molded, and notched Charpy impact strength at 23 ° C. and −30 ° C. was measured according to ISO-179. Was visually observed.

<Examples 1-4>
(Production of modified polycarbonate resin (PC-1))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 4229 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. 2191 parts of phenyl) propane (Bis-1), 1951 parts of bisphenol A and 8.3 parts of hydrosulfite were dissolved, and 11,620 parts of methylene chloride was added, and phosgene 2,200 at 15 to 25 ° C. with stirring. The part was blown in over 60 minutes. After the completion of the phosgene blowing, 704 parts of 48% aqueous sodium hydroxide and 102 parts of p-tert-butylphenol were added, stirring was resumed, 4.32 parts of triethylamine was added after emulsification, and the mixture was further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin-screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.], and the modified polycarbonate resin shown in Table 1 was obtained.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin (Panlite (registered trademark) L-1225LM manufactured by Teijin Chemicals Ltd .; viscosity average molecular weight 18,500), which constitutes the core layer of the polycarbonate resin laminate, is put into a single-screw extruder having a screw diameter of 40 mm to form a skin layer. The modified polycarbonate resin to be used was put into a single screw extruder having a screw diameter of 30 mm. It was kept at an extruder temperature of 280 ° C. and a vent portion vacuum degree of 26 kPa, laminated in two layers by a feed block method, and extruded through a T-die having a set temperature of 280 ° C. The width of the T die was 450 mm, and was adjusted to 350 mm width when the roll contacted by necking between the air gaps. Moreover, the level of the extruder screw of the core layer was kept constant at 40 rpm, and the level of the skin layer was adjusted to 250 to 650 rpm by adjusting the skin screw level of the skin layer. Furthermore, adjustment was performed by the take-up speed so that the total thickness of the resin laminate was constant. Extrusion was performed in the manner shown in FIG. That is, the first, second and third rolls were mirror rolls. All rolls had a roll diameter of 360 mm. The roll temperature was 95 ° C. for the first, second and third rolls. The obtained film was cooled with a mirror-finished roll, and about 50 mm at both ends of the film was finally cut to obtain a polycarbonate resin laminate as shown in Table 2 having a width of 250 mm.

(Manufacture of shaped polycarbonate resin laminate)
A polycarbonate resin (Panlite (registered trademark) L-1225LM manufactured by Teijin Chemicals Ltd.) constituting the core layer of the polycarbonate resin laminate is put into a single screw extruder having a screw diameter of 40 mm, and the modified polycarbonate resin constituting the skin layer is changed to a screw diameter. It put into a 30 mm single screw extruder. It was kept at an extruder temperature of 280 ° C. and a vent portion vacuum degree of 26 kPa, laminated in two layers by a feed block method, and extruded through a T-die having a set temperature of 280 ° C. The width of the T die was 450 mm, and was adjusted to 350 mm width when the roll contacted by necking between the air gaps. The core layer extruder screw rotation speed was fixed at 40 rpm, and the skin layer extruder screw rotation speed was changed to 250 to 1500 rpm to adjust the four-level skin layer. Furthermore, adjustment was performed by the take-up speed so that the total thickness of the resin laminate was constant. This was carried out in the manner shown in FIG. That is, the second roll was a shaping roll, and the first and third rolls were mirror rolls. All rolls had a roll diameter of 360 mm. A V-shaped groove having the following shape was formed on the second roll (width 1,600 mm) and shaped to the full width of the film. The V-shaped groove has a prism shape with a pitch of 50 μm, a height of 25 μm, and an apex angle of 45 °. The roll temperature is 95 ° C. for the first roll, 95 ° C. for the second roll, and 125 ° C. for the third roll, and the speed ratio V1 / V2 between the peripheral speed V1 of the first roll and the peripheral speed V2 of the second roll is 0.998. A melt bank was provided on the second roll. The linear pressure between the first roll and the second roll was held at 12 MPa for shaping. Finally, the film was cut at about 50 mm at both ends to obtain a shaped polycarbonate resin laminate described in Table 3 having a width of 250 mm.

<Example 5>
(Production of modified polycarbonate resin (PC-2))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 4229 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. After dissolving 4382 parts of phenyl) propane (Bis-1) and 8.7 parts of hydrosulfite, add 11,620 parts of methylene chloride, and stir 2,200 parts of phosgene at 15 to 25 ° C. over about 60 minutes. Blew in. After the completion of the phosgene blowing, 704 parts of 48% aqueous sodium hydroxide and 102 parts of p-tert-butylphenol were added, stirring was resumed, 4.32 parts of triethylamine was added after emulsification, and the mixture was further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.] to obtain modified polycarbonate resins listed in Table 1.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-2) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

(Manufacture of shaped polycarbonate resin laminate)
A shaped polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-2) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

<Example 6>
(Production of modified polycarbonate resin (PC-3))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 5236 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. 2,533 parts of phenyl) cyclohexane (Bis-2), 1948 parts of bisphenol A and 9.4 parts of hydrosulfite are dissolved, and 17,540 parts of methylene chloride is added, and phosgene 2 is added at 15 to 25 ° C. with stirring. 200 parts were blown in over 60 minutes. After completion of the phosgene blowing, 654 parts of a 48% aqueous sodium hydroxide solution and 102 parts of p-tert-butylphenol were added and stirring was resumed. After emulsification, 4.32 parts of triethylamine was added, and the mixture was further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.] to obtain modified polycarbonate resins listed in Table 1.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-3) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

(Manufacture of shaped polycarbonate resin laminate)
A shaped polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-3) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

<Example 7>
(Production of modified polycarbonate resin (PC-4))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 5236 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. After dissolving 4704 parts of phenyl) cyclohexane (Bis-2) and 9.4 parts of hydrosulfite, 17,540 parts of methylene chloride was added and 2,200 parts of phosgene was added at 15 to 25 ° C. for about 60 minutes with stirring. It was blown over. After completion of the phosgene blowing, 654 parts of a 48% aqueous sodium hydroxide solution and 102 parts of p-tert-butylphenol were added and stirring was resumed. After emulsification, 4.32 parts of triethylamine was added, and the mixture was further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.] to obtain modified polycarbonate resins listed in Table 1.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-4) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

(Manufacture of shaped polycarbonate resin laminate)
A shaped polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-4) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

<Example 8>
(Production of modified polycarbonate resin (PC-5))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 4229 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. 2191 parts of phenyl) propane (Bis-1), 1951 parts of bisphenol A and 8.3 parts of hydrosulfite were dissolved, and 11,620 parts of methylene chloride was added, and phosgene 2,200 at 15 to 25 ° C. with stirring. The part was blown in over 60 minutes. After completion of the phosgene blowing, 704 parts of 48% aqueous sodium hydroxide solution and 76.92 parts of p-tert-butylphenol were added and stirring was resumed. After emulsification, 4.32 parts of triethylamine was added and further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin-screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.], and the modified polycarbonate resin shown in Table 1 was obtained.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-5) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

(Manufacture of shaped polycarbonate resin laminate)
A shaped polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-5) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

<Example 9>
(Production of modified polycarbonate resin (PC-6))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 4229 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. (Phenyl) propane (Bis-1) 3067 parts, bisphenol A 1170 parts, and hydrosulfite 8.3 parts were dissolved, and then methylene chloride 11,620 parts were added and phosgene 2,200 at 15 to 25 ° C. with stirring. The part was blown in over 60 minutes. After completion of the phosgene blowing, 704 parts of 48% aqueous sodium hydroxide solution and 76.92 parts of p-tert-butylphenol were added and stirring was resumed. After emulsification, 4.32 parts of triethylamine was added and further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin-screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.], and the modified polycarbonate resin shown in Table 1 was obtained.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-6) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

(Manufacture of shaped polycarbonate resin laminate)
A shaped polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-6) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

<Example 10>
(Production of modified polycarbonate resin (PC-7))
A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 4229 parts of a 48% aqueous sodium hydroxide solution and 20,000 parts of ion-exchanged water, and 1,1-bis (4-hydroxy-3-methyl) was added thereto. Phenyl) propane (Bis-1) 1314 parts, bisphenol A 2731 parts, and hydrosulfite 8.3 parts were dissolved, and then methylene chloride 11,620 parts were added and phosgene 2,200 at 15 to 25 ° C. with stirring. The part was blown in over 60 minutes. After completion of the phosgene blowing, 704 parts of 48% aqueous sodium hydroxide solution and 76.92 parts of p-tert-butylphenol were added and stirring was resumed. After emulsification, 4.32 parts of triethylamine was added and further stirred at 28 to 33 ° C. for 1 hour. The reaction was terminated. After completion of the reaction, the product is diluted with methylene chloride, washed with water, acidified with hydrochloric acid, washed with water, and further washed with water until the conductivity of the aqueous phase becomes substantially the same as that of ion-exchanged water. Obtained. Next, this solution is passed through a filter having an aperture of 0.3 μm, and further dropped into warm water in a kneader with an isolation chamber having a foreign matter outlet at the bearing, and the polycarbonate resin is flaked while distilling off methylene chloride. The liquid-containing flakes were pulverized and dried to obtain a powder. Thereafter, tris (2,4-di-tert-butylphenyl) phosphite is added to the powder so as to be 0.0025% by weight and stearic acid monoglyceride to be 0.1% by weight. The powder was melt-kneaded while degassing with a vent type twin-screw extruder [KTX-46, manufactured by Kobe Steel, Ltd.], and the modified polycarbonate resin shown in Table 1 was obtained.

(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-7) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

(Manufacture of shaped polycarbonate resin laminate)
A shaped polycarbonate resin laminate was obtained in the same manner as in Example 1 except that the modified polycarbonate resin (PC-7) was used and the extruder screw rotation speed of the skin layer was changed to 650 rpm.

<Comparative Example 1>
(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate was prepared in the same manner as in Example 1 except that polycarbonate skin (Panlite (registered trademark) L-1225LM manufactured by Teijin Chemicals Ltd.) was used for the skin layer and the screw speed of the skin layer extruder was 650 rpm. Obtained.
(Manufacture of shaped polycarbonate resin film)
A polycarbonate resin laminate was prepared in the same manner as in Example 1 except that polycarbonate skin (Panlite (registered trademark) L-1225LM manufactured by Teijin Chemicals Ltd.) was used for the skin layer and the screw speed of the skin layer extruder was 650 rpm. Obtained.

<Comparative example 2>
(Manufacture of polycarbonate resin laminate)
A polycarbonate resin laminate is obtained in the same manner as in Example 1 except that PMMA (Acrypet (registered trademark) standard grade VH001 manufactured by Mitsubishi Rayon) is used for the skin layer, and the screw speed of the extruder for the skin layer is 600 rpm. It was.
(Manufacture of shaped polycarbonate resin laminate)
Shaped polycarbonate resin laminate in the same manner as in Example 1 except that PMMA (Acrypet (registered trademark) standard grade VH001 manufactured by Mitsubishi Rayon) was used for the skin layer, and the screw speed of the extruder for the skin layer was 600 rpm. Got.

As is clear from the results of Table 1, Table 2, and Table 3, the laminate having the modified polycarbonate resin layer has a good surface hardness and deflection resistance as a brightness enhancement film, while being a polycarbonate resin that is widely used as a skin layer. It can be seen that such useful properties cannot be obtained with polymethylmethacrylate resin. In addition, transferability and brightness enhancement of shaped polycarbonate resin laminates with a modified polycarbonate as a skin layer, as well as transparency of recycled products and good impact strength, are used. Has been found to be suitable for recycling to other useful materials.
That is, according to this invention, it turns out that the favorable brightness enhancement film which cannot be obtained with the polycarbonate resin and polymethylmethacrylate resin which are used widely is obtained.

  The brightness enhancement film of the present invention can be used in liquid crystal display devices for liquid crystal televisions, personal computers, mobile phones, portable game machines, display panels, automobiles, and the like.

A Shaped Shape Height B Shaped Shape Pitch 1 T Die Lip 2 Melt Extruded Film Resin 3 First Roll of Cooling Roll 4 Second Roll of Cooling Roll 5 Third Roll of Cooling Roll 6 Take-off Roll 7 Shaped engraving roll

Claims (8)

A brightness enhancement film comprising a laminate having a total thickness of 0.1 to 1.0 mm comprising a core layer and a skin layer, wherein (i) the core layer is formed from a polycarbonate resin layer, and (ii) the skin layer is It is formed from a modified polycarbonate resin layer containing a carbonate structural unit (structural unit A) represented by the following formula [1], the proportion of which is 20 to 100 mol% in all structural units, and the skin layers are regularly arranged. Brightness-enhancement film, which is a surface shape that is shaped by uneven shape.

Wherein W is a single bond, an alkylene group having 1 to 6 carbon atoms, an alkylidene group having 1 to 6 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a cyclic alkylene group having 3 to 8 carbon atoms. Represents.)   The skin layer is composed of a carbonate structural unit (structural unit A) represented by the above formula [1] and a carbonate structural unit (structural unit B) derived from 2,2-bis (4-hydroxyphenyl) propane. The brightness enhancement film according to claim 1, which is formed from a modified polycarbonate resin layer in which the proportion of unit A is 20 to 90 mol% in all the structural units.   The brightness enhancement film according to claim 1, wherein the skin layer has a thickness of 5 to 100 μm. The modified polycarbonate resin that forms the skin layer is
(1) Viscosity average molecular weight is 1.0 × 10 ^{4 to} 4.0 × 10 ⁴ ,
(2) The pencil hardness measured according to JIS K5600-5-4 is HB to 2H.
(3) The refractive index difference with the polycarbonate resin forming the core layer is within ± 0.01,
(4) Glass transition temperature is 120 ° C to 160 ° C,
(5) 300 ° C., a melt volume rate of 1.2kg load 20 cm ^3/10 minutes or more,
The brightness enhancement film according to claim 1.   The structural unit (A) of the modified polycarbonate resin forming the skin layer is 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane and 2 The brightness enhancement film according to claim 1, which is a structural unit derived from at least one selected from the group consisting of 2,2'-methyl-4,4'-biphenyldiol.   The brightness enhancement film according to claim 1, wherein the structural unit (A) of the modified polycarbonate resin forming the skin layer is a structural unit derived from 2,2-bis (4-hydroxy-3-methylphenyl) propane.   The brightness enhancement film according to claim 1, wherein the structural unit (A) of the modified polycarbonate resin forming the skin layer is a structural unit derived from 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane.   2. The luminance according to claim 1, wherein the irregularly arranged irregular shape is at least one selected from the group consisting of a lenticular type, a prism type, and a linear Fresnel type shape having a pitch of 10 to 300 μm and a height of 10 to 300 μm. Rising film.

Images