JP2010158811A - Method of manufacturing polycarbonate resin sheet having projection and resin sheet manufactured by the method - Google Patents

Abstract

A polycarbonate resin sheet having a fine convex shape is stably produced by a shape extrusion method.
The molten polycarbonate resin material (component A) is sandwiched between a shaping roll having a fine concave shape formed on the surface and a cooling roll facing the shaping roll, thereby forming a convex shape. In the method for producing a polycarbonate resin sheet having a shape of (1), the thickness of the sheet is 0.8 to 3 mm, the height of the convex shape is 20 to 300 μm, and the height is H (μm) and the convexity. In manufacturing a sheet having an H / D in the range of 0.3 to 1 when the width of the shape is D (μm), (II) Shear measured at 280 ° C. with a capillary rheometer as the component A melt viscosity eta ₁ at a speed 6.08 s ^-1, and the melt viscosity eta ₂ at a shear rate of 60.8 sec ^-1, characterized by the use of a polycarbonate resin material satisfying the following formula (1) Production method. 0.03 <log (η ₁ / η ₂ ) <0.5 (1)
[Selection figure] None

Description

  The present invention relates to a method for producing a polycarbonate resin sheet having a convex shape, and a resin sheet produced from the method. More specifically, in the production of a polycarbonate resin sheet having a convex shape formed by a melt extrusion method using a shaping roll, by using a polycarbonate resin material having specific melting characteristics, the thickness of the sheet is increased. The present invention relates to a production method capable of stably producing a sheet having a good shape accuracy even when the height is high, and a resin sheet shaped from the production method. The present invention makes it possible to manufacture a lens shape that requires high accuracy, particularly as the convex shape. As a result, a polycarbonate resin sheet having a lens shape can be produced at low cost by a melt extrusion method. The obtained sheet is particularly suitable as a light diffusing sheet. Therefore, according to the present invention, a light diffusing sheet having high luminance, less luminance unevenness on the light emitting surface, and excellent color tone is provided.

  Polycarbonate resins are excellent in mechanical properties, heat resistance, flame retardancy, and weather resistance, and have a high light transmittance, so that they are used in a wide range of applications. Such applications include, for example, architectural fields such as skydomes, top lights, arcades, condominium waistboards, and road side walls, and have been used in large quantities since ancient times. Light diffusing materials are used for many of these applications. In recent years, the light diffusing material made of such a polycarbonate resin has greatly expanded its use as a light diffusing member by taking advantage of the above-mentioned properties. Applications for which usage is expanding include, for example, various illumination covers, light diffusion sheets for liquid crystal display devices, diffusion sheets for various instruments such as automobile meters, various nameplates, resin window glass, image reading devices, and transmissive screens. Etc. are exemplified. Conventionally, in these applications, a light diffusing material obtained by blending a light diffusing agent with a polycarbonate resin has been often used. Examples of the light diffusing agent include organic particles represented by crosslinked acrylic particles and crosslinked silicone particles, and calcium carbonate and titanium oxide.

  Recent light diffusing members are required to have high light diffusing performance with less luminance unevenness and better light transmittance. Backgrounds of such demands include, for example, power saving by reducing the number of light sources, higher accuracy and higher brightness of an image display device, and point light sources represented by replacement with LEDs. For the purpose of improving the light diffusing ability, a light diffusing sheet (hereinafter sometimes referred to simply as a “shaped light diffusing sheet”) having a fine corrugated pattern having a lens function or a prism shape has been proposed. (See Patent Document 1). In the manufacturing method of a sheet-like molded product, the melt extrusion method is preferable in terms of production efficiency. Therefore, also in the shaped light diffusion sheet, a method of shaping the melt-extruded resin using an engraved cooling roll or the like (hereinafter sometimes simply referred to as “shaped extrusion method”) is preferable. However, the specific disclosure of Patent Document 1 is a method of thermoforming a sheet.

  The present applicant has already proposed a shaped light diffusion sheet made of a polycarbonate resin by a shaped extrusion method (see Patent Documents 2 to 4). More specifically, in Patent Document 2, by using a roll having a V-shaped groove and shaping without full filling with respect to the groove depth, a stable bowl-shaped lens shape is obtained. It is disclosed that a sheet formed with can be manufactured. More specifically, in the embodiment, the sheet is made of a bisphenol A type polycarbonate resin having a viscosity average molecular weight of 25,000, the sheet thickness is 0.5 to 3 mm, the convex height is 2 to 15 μm, and the width is 100 μm. A shaped light diffusing sheet having a bowl-like lens shape is disclosed.

  In Patent Document 3, it is found that by using a polycarbonate resin that satisfies a specific relationship between melt viscosity and load, stable shaping is possible regardless of the state of the melt bank. Discloses a sheet that changes substantially continuously from the central portion to the peripheral portion in a direction perpendicular to the bowl shape. More specifically, the sheet shape disclosed in the examples has a maximum thickness of 1.0 mm and a maximum height of the end portion of 25.9 μm. The polycarbonate resin used for the production of such a sheet is a bisphenol A type polycarbonate resin having a viscosity average molecular weight of 25,000.

  In Patent Document 4, a specific shaping roll is used, and the linear velocity of the shaping roll and the linear velocity of the cooling roll sandwiched between the roll are within a specific range, so that the convex shape is not destroyed. A polycarbonate resin sheet having a convex shape such as a cut spherical shape is disclosed. More specifically, the sheet shape disclosed in the examples has a sheet thickness of 1.0 mm, the convex shape has a height of 100 μm and a diameter of 490 μm, or the sheet thickness is 0.7 mm, and the convex shape has a height of 200 μm. And a diameter of 490 μm. The polycarbonate resin used for the production of such a sheet is a bisphenol A type polycarbonate resin having a viscosity average molecular weight of 23,900.

  However, in order to satisfy the characteristics required for the light diffusing member in recent years, (i) higher height or (ii) higher aspect ratio than the convex shape specifically disclosed in Patent Documents 2 to 4 above. Is required. Alternatively, a thicker light diffusion sheet is required. The reason why a certain thickness is required is mainly for securing rigidity corresponding to the increase in area of the light diffusing member and reducing luminance unevenness.

  As a shaped light diffusion sheet, a sheet in which two or more kinds of different polycarbonate resins are laminated in a multilayer form, a polycarbonate resin layer having a molecular weight of less than 20,000, and a polycarbonate resin layer having a molecular weight of 20,000 or more, And a light control sheet having a concavo-convex shape on the surface having a molecular weight of less than 20,000 is known (see Patent Document 5). In addition, polycarbonate resin with a branch structure unit of more than 0.3 and less than 0.8 mol% produced by transesterification having melt viscosity characteristics in a specific low shear rate range is suitable for profile extrusion and hollow molding. It is known (see Patent Document 6). However, Patent Document 6 did not disclose any description regarding the shape-extrusion method.

International Publication No. 2006/109818 Japanese Patent Laid-Open No. 09-11328 JP 2004-151704 A JP 2006-130901 A JP-A-10-253806 JP 2005-113119 A

  In recent years, in order to further improve the light diffusion function, there is a demand for a shaped light diffusion sheet having a convex shape with a height higher than the width or diameter of the convex shape. For example, when the cross section is a cut spherical convex shape, the convex shape has a fan angle close to 180 degrees. Furthermore, since the image display device and the lighting fixture are increased in area, a certain thickness of the sheet is required to maintain the shape and suppress thermal deformation. The problem to be solved by the present invention is to provide a sheet having a convex shape whose height is higher than the conventional width or diameter of the convex shape and having a fine convex shape having a certain thickness. In addition, a polycarbonate resin material is used for stable production by a shaped extrusion method.

  The present inventors tried a shape extrusion method using a general polycarbonate, for example, in accordance with the methods of Patent Documents 2 and 3, wherein the sheet thickness was increased and the convex shape was increased. However, although such a convex shape is formed in part, it is insufficient or not formed in part, and at least stable continuous production was not possible. In particular, the influence of the sheet thickness is large, and it was unexpected that the shape stability greatly changed even with a slight increase in thickness.

  It is known that a polycarbonate resin having a low molecular weight is generally effective for transferability to a mold shape. Said patent document 5 is also an invention based on such knowledge. Therefore, we tried the shape-extrusion method using a low molecular weight polycarbonate resin, but the results were similarly insufficient.

  Thus, even when a conventionally known technique is used, a shaped light diffusion sheet made of a polycarbonate resin material having a convex shape with a height higher than the convex width or diameter was not obtained. The inventors surprisingly used a polycarbonate resin whose melt viscosity is highly dependent on the shear rate in a very low shear rate range, and that the fine convex shape is constant over the entire sheet width, so that continuous production is stable. The present inventors have found that it is possible to perform shape extrusion with excellent properties, and have further intensively studied to complete the present invention.

The objects of the present invention are as follows: (1) The molten polycarbonate resin material (component A) is narrowed between a shaping roll having a fine concave shape formed on the surface and a cooling roll facing the shaping roll. A method for producing a polycarbonate resin sheet having a convex shape,
(I) When the thickness of the sheet is 0.8 to 3 mm, the height of the convex shape is 20 to 300 μm, the height is H (μm), and the width of the convex shape is D (μm), H / D In manufacturing a sheet having a range of 0.3 to 1,
(II) As the component A, melt viscosity η ₁ at a shear rate of 6.08 seconds ⁻¹ and melt viscosity η ₂ at a shear rate of 60.8 seconds ⁻¹ measured at 280 ° C. with a capillary rheometer This is achieved by a production method using a polycarbonate resin material satisfying the following formula (1).
0.03 <log (η ₁ / η ₂ ) <0.5 (1)

  Here, the convex height H refers to the maximum height from the reference surface on the shaping side. The reference surface on the shaping side is formed by the reference surface of the shaping roll. The convex width D refers to the width when the cross section in the sheet width direction is viewed when the ridge-shaped convex shapes are arranged in the width direction of the sheet. In the case where the ridge-like convex shapes are arranged in the length direction (extrusion direction) of the sheet, D is a width when a cross section in the length direction is viewed. In addition, when the convex shape is not a bowl shape and is an independent shape, the shorter one of the width direction or the length direction of the sheet when viewed from the substantially normal direction of the reference surface on the shaping side. Say.

  The thickness of the sheet is preferably 1.0 to 2.7 mm, more preferably 1.2 to 2.5 mm, and particularly preferably 1.3 to 2.3 mm. The convex shape is basically set as appropriate according to the required optical properties, but H is preferably 40 to 200 μm, more preferably 70 to 150 μm. The value of H / D is preferably 0.35 to 0.8, more preferably 0.4 to 0.6.

  Measurement of melt viscosity with a capillary rheometer under condition (II) is performed, for example, by the following method. That is, after drying the resin material using a hot air dryer at 120 ° C. for 6 hours, the resin material at 280 ° C. under the conditions of barrel inner diameter: 9.55 mm, capillary length: 10.1 mm, capillary inner diameter: 1.0 mm The melt viscosity of is measured. The measurement was performed by changing the piston speed to 0.5, 1, 2, 5, 10, 20, 30, 50, 75, 100, 200, 300, 500, and 1000 mm / min in order, and from the detected load, the melt viscosity Is calculated. As a capillary rheometer suitable for the measurement of the melt viscosity, for example, there is a Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd., and such an apparatus is widely known.

The condition (II) in the configuration (1) is an index indicating the shear rate dependence of the melt viscosity in the low speed region. When the logarithm of the shear rate is taken on the horizontal axis and the logarithm of the melt viscosity is taken on the vertical axis, the log (η ₁ / η ₂ ) in the above formula (1) is changed from the shear rate of 6.08 sec ⁻¹ to the shear rate of 60. It represents the slope of the melt viscosity between 8 seconds ^-1 . That is, it is an index showing the shear rate dependence of the melt viscosity. The lower limit of the formula (1) is preferably 0.05, more preferably 0.08, and more preferably 0.10. The upper limit of the formula (1) is preferably 0.35, more preferably 0.25. If the log (η ₁ / η ₂ ) in the formula (1) is less than or equal to the lower limit, the melt viscosity difference is low, so that the formability is inferior.

  Although the reason why such melt viscosity characteristics enable good shaped extrusion is not clear, the present inventors speculate as follows. For example, in the shape extrusion method including a first roll as a cooling roll for sandwiching and a second roll as a shaping roll directly under a T die, a sandwich is formed while forming a melt bank on the second roll. The resin is volume-compressed by reduction, and the resin is shaped by applying a high pressure. At this time, although the resin of the extreme surface layer in contact with the cooling roll is solidified, the resin of the inner layer is considered to be melted due to its low thermal conductivity. In the shaping by the roll, unlike the compression in the mold, there is a resin escape. When the melt viscosity of the resin is low, the resin subjected to the compression action easily escapes in the in-plane direction due to the resistance of the solidified surface layer. In order to perform high H / D shaping, it is necessary to increase the pressure of the resin on the shaping roll, but on the other hand, it is considered that the resin easily escapes when high pressure is applied. In the study by the present inventors, behaviors having greatly different formability in the sheet width direction were recognized. This is because the compressed resin escapes little by little, and as a result of the stacking, a large resin flow can occur in the width direction and length direction (rotation direction of the roll), and as a result, deformation of the resin in the compression direction is hindered. I guess. The reason why the shapeability is greatly deteriorated when the thickness of the sheet is increased is considered to be that the internal resin temperature is hardly lowered by the heat insulating action of the resin, and the resin viscosity is low. If the temperature of the molten resin is lowered to improve this point, the melt viscosity at the time of discharging from the T die also increases, and defects in the extrusion molding itself tend to increase.

Generally the shear rate at the time of compression molding is said to be in the speed range of 1～10Sec ^-1, whereas, the shear rate at the time of extrusion, a speed range of about 100 sec ^-1. Η ₁ defined in the present invention can be said to be a melt viscosity representative of the former compression molding region, and η ₂ is considered to be a melt viscosity representative of the latter extrusion molding region. As described above, a more preferable resin material for the problem of the present invention is required to have a low viscosity at the time of extrusion and no turbulence of flow from the T-die. Less is required. The polycarbonate resin material of the present invention is considered to satisfy this requirement by having a high melt viscosity and shear rate dependency that satisfies the above-mentioned formula (1). As a result, it is assumed that high H / D shaping can be achieved even when the sheet thickness is relatively thick.

In addition, although the said consideration showed the example of the shaping | molding with a 2nd roll, the situation that an inside is hard to be cooled by becoming thick is the same also when shaping with a 3rd roll. . Further, from the viewpoint of formability in the roll, the melt viscosity η ₁ at a shear rate of 6.08 seconds ⁻¹ is preferably 1,800 to 8,000 Pa · s, more preferably 2,500 to 7,000 Pa. · S, more preferably 3,000 to 5,000 Pa · s. Details of the polycarbonate resin material will be described later.

  One of the preferable aspects of the present invention is that (2) the configuration (1) wherein the shaped convex shape is a convex shape regularly arranged in a width direction of the sheet or / and a direction perpendicular to the width direction. More preferably, (3) the regularly arranged convex shapes are the manufacturing method of such a configuration (2) having a bowl-like lens shape, and particularly preferably (4) the above-mentioned In this manufacturing method (4), the lens shape is a lenticular type, a prism type, or a linear Fresnel type. Here, in the configuration (2), “the width direction of the sheet or / and the direction perpendicular to the width direction” means that the convex shapes are regularly arranged on one side in the width direction of the sheet or in the direction perpendicular to the width direction, In addition, the convex shape includes a regular arrangement in the width direction of the sheet on one side and a direction perpendicular to the width direction on the other side. The convex shape of the present invention includes both modes of single-sided shaping and double-sided shaping. The convex shape of the present invention is preferably a shape having a lens function that requires higher accuracy. The convex shape of the lens function includes a lens array including a so-called fly-eye lens, but more preferably has a bowl-shaped lens shape, and the configuration (4) is particularly preferable.

One of the preferred embodiments of the present invention is that (5) the regularly arranged convex shapes are regularly arranged in the width direction of the sheet and are suitable over the width of the sheet. Particularly preferred is a lenticular type. It is a manufacturing method of said structure (2)-(4) whose fluctuation | variation rate (alpha) of convex height shown by following formula (2) is calculated | required, and this fluctuation | variation rate is less than 5%.
α (%) = 100 × (H _MAX −H _MIN ) / {(H _MAX + H _MIN ) ÷ 2} (2)
(Here, H _MAX indicates the maximum value of height and H _MIN indicates the minimum value.)

Here, H _MAX and H _MIN are measured as follows. When the width of the sheet is about 1,000 mm and a convex shape is formed substantially over the entire area, the convex shape has a number of around 10,000 over the sheet width. Therefore, it is not efficient to measure all convex shapes. On the other hand, as described above, since a large flow of resin is involved in the transfer failure, it is possible to grasp the substance by sampling measurement at a constant period. Therefore, H _MAX and H _MIN are obtained by measuring the height of the portion that is in the range of 20 to 30 points at regular intervals with respect to the width of the shaped portion of the sheet. For example, when it is shaped over the entire area of a sheet having a width of 1,200 mm, a method of measuring at intervals of 50 mm is exemplified. According to the present invention, there is provided a shaped sheet provided with a constant high H / D convex shape that satisfies the configuration (5).

One of the preferable aspects of the present invention is that (6) the shaping roll has a regular groove shape in the circumferential direction or the width direction of the roll, and the cross-sectional area P of the groove shape of the shaping roll. The manufacturing method according to any one of the configurations (1) to (6), wherein the transfer ratio Q / P to the transferred cross-sectional area Q is in the range of the following formula (3).
0.3 <Q / P <0.95 (3)

  In the production method of the present invention, even if the convex shape of the sheet faithfully transfers the concave shape of the shaping roll, as described in Patent Documents 2 and 3, etc., The shape may be a predetermined shape. However, faithful transfer requires high-pressure filling that sufficiently compensates for heat shrinkage of the resin, and thus transfer tends to be difficult. Therefore, a method of obtaining a predetermined shape with insufficient transfer is preferably used, and particularly preferable when the convex shape is a curved surface. A preferred embodiment in such a case is shown as the condition of the formula (3). In the formula (3), the lower limit is preferably 0.35, more preferably 0.4, and the upper limit is preferably 0.9, more preferably 0.8. For example, when a convex shape whose section is a cut sphere is formed on a sheet, the concave shape of the shaping roll is V-shaped (including curved shapes such as parabola and sine curve), inverted trapezoidal shape (V-shaped) Similarly, including curved shapes), and hemispherical shapes can be used.

  One of the preferable aspects of the present invention is that (7) the first roll, the second roll, and the third roll are arranged in this order, the second roll is the shaping roll, and the first roll is opposed to the shaping roll. It is a manufacturing method of said structure (1)-(6) used as a cooling roll. The production method of the present invention is a melt extrusion method in which a polycarbonate resin material melted from a die of a melt extruder is extruded into a sheet shape, and at least one shaping roll is held between a plurality of cooling rolls and the pressed sheet is taken up. It is. At least two cooling rolls are used, usually 2-4. Here, the shaping roll is preferably provided on the second roll or the third roll, and in the present invention, the second roll is particularly preferred. This is because the polycarbonate resin material of the present invention exhibits a high viscosity during compression even when the resin temperature is high. Furthermore, when shaping on both sides of the sheet, for example, there is a method in which both the second roll and the third roll are shaped rolls. It is also advantageous in the method. In addition, the said description is made into the 1st roll, the 2nd roll, and the 3rd roll in order toward the take-up side from the extruder side.

  In one preferred embodiment of the present invention, (8) the polycarbonate (component a) in the component A comprises 0.05 to 1 mol% of a carbonate structural unit having a branched structure in 100 mol% of the carbonate structural unit. Viscosity average molecular weight 20,000-55,000 mixed with polycarbonate (a-i component), or polycarbonate having viscosity average molecular weight 70,000-300,000 and polycarbonate having viscosity average molecular weight 10,000-40,000 It is a manufacturing method of said structure (1)-(8) which is a polycarbonate (a-ii component). The polycarbonate resin material which is the component A of the present invention is not particularly limited as long as it satisfies the condition (II) of the configuration (1). Methods for satisfying such conditions include (a) increasing the molecular weight of the polycarbonate (for example, if the bisphenol A type polycarbonate is a viscosity average molecular weight of 28,000 or more), (b) introducing a branched structure into the polycarbonate. , (C) mixing high molecular weight polycarbonates, and (d) mixing other high molecular weight polymers. Among these, (b) introduction of a branched structure and (c) mixing of a high molecular weight polycarbonate in that the dependence of the melt viscosity on the shear rate in the low shear rate region can be further improved and good optical properties can be obtained. Is particularly preferred.

  The polycarbonate having a branched structure more preferably satisfies the conditions of the ai component. In the range of such a branched structure, high viscosity in a low shear rate region is obtained, and the productivity of the polymer itself is excellent. The lower limit is preferably 0.1 mol%, more preferably 0.2 mol%. On the other hand, the upper limit is preferably 0.8 mol%, more preferably 0.7 mol%. Such a branched structure is obtained as a side reaction in a melt transesterification reaction or the like even if a polyfunctional phenol and / or polyfunctional alcohol is copolymerized. Also good. Multifunctional phenols and alcohols are preferably trifunctional and tetrafunctional, particularly trifunctional. Specific examples of such phenol will be described later. The viscosity average molecular weight of the ai component is preferably 17,000 to 40,000, more preferably 19,000 to 30,000, still more preferably 20,000 to 28,000.

  In the a-ii component, the viscosity average molecular weight of the former high molecular weight polycarbonate is preferably 70,000 to 250,000, more preferably 100,000 to 200,000. The viscosity average molecular weight of the latter low molecular weight polycarbonate is preferably 18,000 to 32,000, more preferably 20,000 to 28,000. Furthermore, the viscosity average molecular weight of a-ii component becomes like this. Preferably it is 22,000-45,000, More preferably, it is 25,000-40,000. In addition, since the rheological characteristic of such a-ii component is greatly different from that of a single linear polycarbonate, the preferable molecular weight range is greatly different from that of the above-mentioned branched polycarbonate.

  As said (d) other polymer of high molecular weight, Preferably the method of mixing a small amount of high molecular weight components which have a molecular weight of 200,000 or more is used. Preferred examples of such a polymer include polytetrafluoroethylene, polystyrene, polymethyl methacrylate, and styrene-acrylonitrile polymers, and mixtures thereof. The molecular weight of such high molecular weight polymer is preferably 500,000 or more. The upper limit of the molecular weight is preferably 10 million. The mixing amount is 0.05 to 5% by weight, preferably 0.3 to 3% by weight, in 100% by weight of component A. In the method (d), the viscosity average molecular weight of the polycarbonate is preferably 17,000 to 40,000, more preferably 19,000 to 30,000, still more preferably 20,000 to 28,000. Such a method can be combined with the above-described methods (a) to (c).

  One of the preferred embodiments of the present invention is as follows. (9) The components (1) to (9), wherein the component A contains 0.01 to 2% by weight of organic fine particles having an average particle size of 0.5 to 10 μm as a diffusing agent. It is a manufacturing method of 8). Since the polycarbonate resin sheet of the present invention can exhibit an excellent light diffusion function, it can contain a light diffusion agent for the purpose of further improving and adjusting the function. Among them, it is preferable to use organic fine particles that satisfy the condition of the constitution (9) that has little adverse effect on the shaping roll even in long-term continuous production and is excellent in light diffusibility. Such organic fine particles are preferably crosslinked particles. The crosslinked organic fine particles are at least partially crosslinked in the production process, are not practically deformed in the process of processing the polycarbonate resin material, and maintain the fine particle state. That is, fine particles that do not melt in the resin even when heated to the molding temperature of the polycarbonate resin, preferably 350 ° C., are more preferable. More preferred are organic fine particles of a crosslinked (meth) acrylic resin or silicone resin. Particularly preferred specific examples thereof include, for example, polymer particles based on partially crosslinked methyl methacrylate, polymer particles having a poly (butyl acrylate) core / poly (methyl methacrylate) shell, and cores and shells of rubbery vinyl polymer. Fine particles having a core / shell morphology containing bismuth [represented by Rohm and Hers Company, trade name Paraloid (registered trademark) EXL-5136], and fine silicone resin particles having a crosslinked siloxane bond [Momentive Performance Material Represented by Tospearl (registered trademark) 120 manufactured by Co., Ltd.], which may be used alone or as a mixture of two or more kinds of fine particles.

  The average particle size of the diffusing agent fine particles is preferably 0.5 to 10 μm, more preferably 1 to 5 μm. The average particle diameter of such fine particles is a weight average particle diameter measured by a Coulter counter method. In such a preferable average particle diameter range, a good light diffusion function is exhibited, and the synergistic effect with the shaped sheet can be further enhanced. The particle size distribution may be single or plural. That is, it is possible to combine two or more light diffusing agents having different average particle diameters. However, a more preferred light diffusing agent has a narrow particle size distribution. The variation coefficient represented by “particle diameter standard deviation σ / average particle diameter D × 100 (%)” is preferably within 20%, more preferably within 10%, and even more preferably within 7%. An appropriate lower limit is 1%. The shape of the light diffusing agent is preferably close to a sphere from the viewpoint of light diffusibility, and more preferably a shape close to a true sphere. More nearly spherical means more specifically a shape having a ratio of major axis to minor axis within 1.1. Such a spherical shape includes an elliptical sphere.

  Another aspect of the present invention is (10) a polycarbonate resin sheet having a convex shape produced from the production method of the above constitutions (1) to (9), and (11) the resin sheet is a light diffusing material. It is a polycarbonate resin sheet of the configuration (10), which is a sheet.

In another aspect of the present invention, (12) a polycarbonate resin material (component A) produced by melt extrusion is formed with a regularly arranged convex shape over a substantially entire area of at least one surface. A polycarbonate resin sheet,
(I) When the thickness of the sheet is 0.8 to 3 mm, the height of the convex shape is 20 to 300 μm, the height is H (μm), and the width of the convex shape is D (μm), H / D Is in the range of 0.3 to 1,
(Ii) When the convex shape regularly arranged is regularly arranged in the width direction of the sheet, and the fluctuation rate of the convex height represented by the following formula (2) is obtained over the width of the sheet, The rate of change is less than 5%,
(Iii) the A component is measured at 280 ° C. by capillary rheometer, the melt viscosity eta ₁ at a shear rate of 6.08 sec ^-1, and the melt viscosity eta ₂ at a shear rate of 60.8 sec ^-1 The polycarbonate resin sheet satisfies the following formula (1).
0.03 <log (η ₁ / η ₂ ) <0.5 (1)
α (%) = 100 × (H _MAX −H _MIN ) / {(H _MAX + H _MIN ) ÷ 2} (2)
(Here, H _MAX indicates the maximum value of height and H _MIN indicates the minimum value.)

  Furthermore, one of the suitable aspects of the present invention is (13) the polycarbonate resin sheet having the constitution (12), wherein the resin sheet is a light diffusion sheet.

Hereinafter, the details of the present invention will be described.
<Sheet manufacturing method>
A sheet manufacturing method will be described with reference to the drawings. FIG. 1 is a schematic view showing an example of an apparatus for producing a light diffusing sheet by a shaped extrusion method in the present invention. In FIG. 1, reference numerals 1, 2 and 3 denote cooling rolls, which are hereinafter referred to as a first roll, a second roll and a third roll in this description. Of these, fine engraving grooves are preferably provided in a ring shape on the surface of at least one roll, preferably the second roll or the third roll or both. A roll other than the shaping roll is a mirror roll. For example, when the second roll is a shaping roll, the first roll and the third roll are mirror rolls. Hereinafter, description will be given based on such roll arrangement. In the figure, 4 is a melt bank, 5 is a melt-extruded sheet-like resin, 6 is a T-die lip, and 7 is a take-up roll. The melt extruder not shown may be a single screw extruder or a twin screw extruder. The extrusion temperature is usually 250 to 350 ° C, preferably 260 to 320 ° C. For the purpose of preventing thermal deterioration of resin, coloring, prevention of T-die lips, 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.

A specific manufacturing method of the light diffusion sheet will be described. The polycarbonate resin material is melted in an extruder and extruded through a T-die lip 6 into a sheet shape. In such an extrusion, the shear rate gamma _T apparent represented by the following formula, preferably 30～500Sec ^-1, more preferably 50～300Sec ^-1, more preferably adjusted to a range of 60~200sec ^-1. Here, γ _T (sec ⁻¹ ) is represented by γ _T = (6Q / Wh ² ), Q: flow rate (m ³ / sec), W: die width (m), and h: die slit thickness (m ).

  The sheet 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 sheet is given a fine lens shape by the engraving grooves formed on the surface of the second roll, cooled, and then taken up by the take-up roll 7. 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 40 to 400 μm, more preferably 80 to 300 μm. The pitch of the convex shape in the shaped sheet depends on the pitch of the engraving grooves of the roll. It is desirable that the saddle-like convex shapes suitable in the present invention have the same pitch. Therefore, the pitch of the engraving grooves is a constant value, and as a result, a sheet in which a number of bowl-shaped lens shapes are regularly arranged at the same pitch is desirable. The pitch value is basically determined as appropriate in the required optical design, but in the range of 40 to 400 μm, the sheet has excellent light diffusibility and productivity, and roll engraving productivity. The groove depth of the engraving groove roll used in the present invention is preferably 30 to 400 μm. Such a lower limit is more preferably 50 μm, still more preferably 100 μm. On the other hand, the upper limit is preferably 300 μm, more preferably 250 μm. The depth of the groove of the roll is designed in consideration of the transfer rate to the sheet, and can be engraved using a known engraving machine.

  In the method for producing a polycarbonate resin sheet having a fine convex shape, a position in which a melt-extruded sheet-like polycarbonate resin is sandwiched between a first roll and a second roll and pressed by the two rolls, That is, when the roll is viewed from the side with respect to the extrusion direction, the contact point of the second roll of the line connecting the center of the circle of the second roll and the center of the circle of the first roll is X (point X in FIG. 2), When the point where the extruded resin leaves the shaping roll as the second roll is Y (point Y in FIG. 2), the angle from X to Y with respect to the center of the second roll (that is, the resin on the second roll) When the holding angle (angle θ in FIG. 2) is defined as the holding angle (the angle θ in FIG. 2), the holding angle at which the extruded resin contacts the mold roll is important, and the angle θ is preferably 90 to 225 degrees. Range, more preferably 135- The range is 180 degrees.

  The linear pressure when sandwiched between the shaping roll and the opposing cooling roll and pressed by the two rolls is preferably in the range of 4 to 8 MPa · cm, more preferably in the range of 5 to 7 MPa · cm. It is more preferable that In particular, when the shaping roll is the second roll, the linear pressure between the second roll and the first roll preferably satisfies this range. By pressing the sheet with a pressure in this range, the concave shape engraved on the die roll is sufficiently transferred. In addition, when the third roll is not a shaping roll and the polycarbonate resin sheet is pulled while being in contact with the third roll, it is not necessary to press, and when pressing between the second roll and the third roll, the linear pressure Is preferably in the range of up to 1 MPa · cm.

  In the said manufacturing method, when the glass transition temperature of the polycarbonate (a component) to be used is set to Tg, it is preferable to adjust the roll temperature of a 1st roll in the range of Tg-50-Tg-20 degreeC, Tg-45- It is more preferable to adjust to the range of Tg-25 ° C. When the polycarbonate resin to be used is a polycarbonate resin obtained from bisphenol A, the roll temperature of the first roll is preferably adjusted to a range of 95 to 125 ° C, and more preferably adjusted to a range of 100 to 120 ° C. By adjusting the roll temperature of the first roll to such a temperature range, a sheet having a uniform surface shape on the mirror surface side with little thickness unevenness can be obtained.

  It is preferable to adjust the roll temperature of a 2nd roll to the range of Tg-90-Tg-15 degreeC, and it is more preferable to adjust to the range of Tg-85-Tg-20 degreeC. When the polycarbonate resin to be used is a polycarbonate resin obtained from bisphenol A, the roll temperature of the second roll is preferably adjusted to a range of 55 to 130 ° C, more preferably adjusted to a range of 60 to 125 ° C. Note that the roll temperature of the second roll is desirably adjusted by the thickness of the sheet. In order to fully transfer the concave shape engraved on the roll with mold to the sheet, it is preferable to adjust the roll temperature higher because the resin is easily cooled if the sheet is thin, and the sheet is thick In order to reduce the fluidity of the resin, it is preferable to adjust the roll temperature to be low. In the present invention, the roll temperature is more preferably adjusted in the range of Tg-90 to Tg-50 ° C. The roll temperature of the third roll is preferably adjusted to a range of Tg-25 to Tg ° C, and more preferably adjusted to a range of Tg-20 to Tg-5 ° C. When the polycarbonate resin to be used is a polycarbonate resin obtained from bisphenol A, the roll temperature of the third roll is preferably adjusted to a range of 120 to 145 ° C, and more preferably adjusted to a range of 125 to 140 ° C. When the roll temperatures of the first roll, the second roll, and the third roll satisfy the above range, the concave shape engraved on the die-formed roll is sufficiently transferred to the sheet, and the convex shape does not lose its shape. Since cooling is performed, it is preferable.

  At this time, the sheet is given a fine lens shape by engraving grooves formed on the roll, cooled, and then taken up by the take-up roll 7. The roll diameters of the rolls 1, 2 and 3 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, particularly those having the same diameter of 250 to 500 mm. Preferably used.

In Patent Document 3, it is disclosed that the formation of a melt bank is important in the shape extrusion method, while the melt bank is difficult to stabilize. The polycarbonate resin material of the present invention has excellent stability with little fluctuation of the melt bank, and as a result, enables good shape extrusion. Such stability is also considered to be an effect of high viscosity in a low shear rate region. By using the stability of the melt bank effectively for the shaping extrusion, a homogeneous shaped sheet can be produced more stably. When the melt bank horizontal thickness is m ₁ and the sheet thickness is t ₁ , the melt bank ratio m ₁ / t ₁ is preferably in the range of 0.3 to 2.5, more preferably 0.5 to 2. It is preferable that The melt bank width can be adjusted by, for example, automatic measurement control method by installing a bank sensor using a radiation thermometer, video camera system that captures visually, optical fiber system, and adjusting the die temperature and the lip interval of the die by visual inspection. And the like.

<Polycarbonate resin sheet>
The polycarbonate resin sheet of the present invention may be a single layer, but if necessary, a laminate in which a layer having, for example, a UV cut function, an antistatic performance, an IR cut performance, and an electromagnetic wave cut performance is laminated on one side and / or both sides. It may be a body. As a method for obtaining a laminate, there are a method by coextrusion or a method in which a laminate film or a transfer foil is thermocompression bonded after melt extrusion. In order to improve the light diffusion function, a layer of 10 to 100 μm is provided on one side or both sides of the shaped sheet, and the layer contains a light diffusing agent having a particle size of 10 μm or more, mica, talc, etc. An embossed pattern may be formed. The surface of the polycarbonate resin sheet is expected to be improved in diffusibility due to a geometric pattern such as a concavo-convex shape, and when a functional film is overlaid, it can have appropriate pores, resulting in an increase in luminance. Further, in the use of the light diffusion sheet of the present invention, the sheet may be used alone or may be used by overlapping a plurality of sheets.

<About component A: polycarbonate resin material>
The component A polycarbonate resin material refers to a resin material containing polycarbonate (a component) as a main component, that is, 50% by weight or more. The content of the polycarbonate in the component A is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably 95% by weight or more. Examples of components other than polycarbonate in the component A include other polymers, organic additives, and inorganic additives. Hereinafter, details of the polycarbonate (component a) and the components that can be blended will be described.

<a component: About polycarbonate>
The a component polycarbonate is known per se and has been used for various molded articles. That is, it is obtained by reacting a dihydric phenol or / and an aliphatic difunctional alcohol or / and an alicyclic bifunctional alcohol with 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. In the case of interfacial polycondensation, a terminal stopper of a monohydric phenol is usually used. As described above, the polycarbonate component a may be a branched polycarbonate obtained by polymerizing a trifunctional or higher polyfunctional component in addition to the dihydric phenol or difunctional alcohol. A particularly preferred embodiment is the ai component of the aforementioned constitution (9). Further, it may be a copolymerized polycarbonate obtained by copolymerizing an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, a polyorganosiloxane component, and a vinyl monomer.

A suitable polycarbonate having a structural unit composed of a dihydric phenol is represented by the following formula (i).
(A is at least one divalent organic residue selected from the group consisting of the following formulas (i-1) to (i-3) and (i-5), a single bond, or the following formula (i-4 ) And s and t are each independently 0 or an integer of 1 to 4, and R ₁₃ and R ₁₄ are each independently a halogen atom or an alkyl group having 1 to 10 carbon atoms. , An alkoxy group having 1 to 10 carbon atoms, a cycloalkyl group having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and a carbon number It represents an organic residue selected from the group consisting of an aryloxy group having 6 to 10 carbon atoms and an aralkyloxy group having 7 to 20 carbon atoms.)

(In formula (i-1), R ₁₅ , R ₁₆ , R ₁₇ and R ₁₈ each independently represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 3 carbon atoms.)

(In formula (i-2), R ₁₉ and R ₂₀ each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 3 carbon atoms.)

(In the formula (i-3), u represents an integer of 4 to 11, and the plurality of R ₂₁ and R ₂₂ are each independently selected from a hydrogen atom, a halogen atom, and an alkyl group having 1 to 3 carbon atoms. Represents a group to be

(In formula (i-5), R ₂₃ and R ₂₄ each independently represent a group selected from a hydrogen atom, a halogen atom, and a hydrocarbon group having 1 to 10 carbon atoms.)

Next, specific examples of the formula (i) will be described based on specific examples of the dihydroxy compound from which the structural unit is derived.
Examples of the compound when A in the chemical formula (i) is a single bond include 4,4′-biphenol and 4,4′-bis (2,6-dimethyl) diphenol.

  Examples of the compound when A in the chemical formula (i) is the formula (i-1) include α, α′-bis (4-hydroxyphenyl) -o-diisopropylbenzene, α, α′-bis (4-hydroxyphenyl). ) -M-diisopropylbenzene, and α, α′-bis (4-hydroxyphenyl) -p-diisopropylbenzene.

  The compound when A in the chemical formula (i) is the formula (i-2) includes 9,9-bis (4-hydroxyphenyl) fluorene and 9,9-bis (4-hydroxy-3-methylphenyl). Fluorene etc. are mentioned.

  As the compound when A in the chemical formula (i) is the formula (i-3), 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3, 5-trimethylcyclohexane, 1,1-bis (4-hydroxy-3methylphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -4-isopropylcyclohexane, and 1,1-bis (3-cyclohexyl-4) -Hydroxyphenyl) cyclohexane and the like.

  Examples of the compound when A in the chemical formula (i) is any one of the formula (i-4) include 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether. -Tell, 4,4'-dihydroxydiphenyl sulfone, 2,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4 ' -Dihydroxydiphenyl sulfide, bis (3,5-dimethyl-4-hydroxyphenyl) sulfone and the like.

  As a compound when A in chemical formula (i) is any one of formula (i-5), 1,1-bis (4-hydroxyphenyl) methane, 2,4′-dihydroxydiphenylmethane, bis (2-hydroxy) Phenyl) methane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5-nitrophenyl) methane, bis (4-hydroxy-2,6-dimethyl-3-methoxyphenyl) methane, bis (4-hydroxy) Phenyl) cyclohexylmethane, bis (4-hydroxyphenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxy-2-phenyl) -1-phenylethane, 1,1 -Bis (4-hydroxy-2-chlorophenyl) ethane, 2,2-bis (4-hydroxyphenyl) propyl Bread (usually referred to as “bisphenol A”), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2 -Bis (4-hydroxy-3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-ethylphenyl) propane, 2,2-bis (4-hydroxy-3-isopropylphenyl) propane, 2, 2-bis (3-t-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) ) Propane, 2,2-bis (4-hydroxyphenyl) -1-phenylpropane, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3 -Hexafluoropropane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 2,2-bis (4-hydroxyphenyl) butane, 4,4-bis ( 4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) octane, 1,1-bis (4-hydroxyphenyl) decane, 1,1-bis (3-methyl-4-hydroxyphenyl) decane, And 1,1-bis (2,3-dimethyl-4-hydroxyphenyl) decane and the like.

  Furthermore, as the dihydric phenol from which the structural unit other than the chemical formula (i) is derived, 2,6-dihydroxynaphthalene, hydroquinone, resorcinol, resorcinol substituted with an alkyl group having 1 to 3 carbon atoms, 3- (4 -Hydroxyphenyl) -1,1,3-trimethylindan-5-ol, 1- (4-hydroxyphenyl) -1,3,3-trimethylindan-5-ol, 6,6'-dihydroxy-3,3 , 3 ′, 3′-tetramethylspiroindane, 1-methyl-1,3-bis (4-hydroxyphenyl) -3-isopropylcyclohexane, 1-methyl-2- (4-hydroxyphenyl) -3- [1 -(4-Hydroxyphenyl) isopropyl] cyclohexane, 1,6-bis (4-hydroxyphenyl) -1,6-hexanedione And ethylene glycol bis (4-hydroxyphenyl) ether, and the like.

  Among the dihydric phenols, bisphenol M in formula (i-1), 9,9-bis (4-hydroxy-3-methylphenyl) fluorene in formula (i-2), 1, in formula (i-3), 1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxy-3methylphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, formula ( 3,4'-Dimethyl-4,4'-dihydroxydiphenyl sulfide is preferred for i-4), and bisphenol A, bisphenol C, and 1,1-bis (4-hydroxyphenyl) decane are preferred for formula (i-5). .

  Other details of the polycarbonate are described in, for example, WO03 / 080728 pamphlet, JP-A-6-172508, JP-A-8-27370, JP-A-2001-55435, and JP-A-2002-117580. Has been.

As the bifunctional alcohol for deriving the structural unit of the polycarbonate of the present invention, an alicyclic diol is more preferable. For example, cyclohexanedimethanol, cyclohexanediol, tricyclo (5.2.1.0 ^2,6 ) decanedimethanol. , Norbornanedimethanol, decalin-2,6-dimethanol, spiroglycol, 1,4; 3,6-dianhydro-D-glucitol, 1,4; 3 6-dianhydro-D-mannitol, and 1,4; 3 , 6-dianhydro-L-iditol and the like.

  Further, as the component A of the present invention, a polycarbonate-polyorganosiloxane copolymer obtained by copolymerizing polyorganosiloxane units can be used. The polycarbonate-polyorganosiloxane copolymer is preferably a polycarbonate part composed of a structural unit represented by the general formula (ii-1) and a polyorganosiloxane part composed of a structural unit represented by the general formula (ii-2). Can be mentioned in the molecule.

Here, Z in the formula (ii-1) represents a dihydric phenol and / or an aliphatic and / or alicyclic difunctional alcohol for deriving a structural unit of the polycarbonate part as HO-Z-OH. Represents such a divalent residue -Z-. R ₁ , R ₂ , R ₃ and R _{4 each} represent an alkyl group having 1 to 6 carbon atoms or a phenyl group, and may be the same or different, and is preferably a methyl group. R ₅ represents a divalent organic residue from an aliphatic or aromatic compound, preferably an o-allylphenol residue, a p-hydroxystyrene residue, a 4-allyl-2-methoxyphenol residue, and an iso It is a propenylphenol residue, and an o-allylphenol residue is particularly preferable. N represents the degree of polymerization of the structural units in parentheses, and the structural units may be a mixture of two or more. The range of n is 1 to 500, preferably 5 to 200, more preferably 10 to 70, and still more preferably 15 to 30 in the number average value. The upper limit of the number of each component n is preferably 500, more preferably 200, and still more preferably 70.

Examples of the trifunctional or higher functional compound used in the branched polycarbonate include 4,6-dimethyl-2,4,6-tris (4-hydroxydiphenyl) heptene-2, 2,4,6-trimethyl-2, 4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (4-hydroxyphenyl) benzene, 1,1,1-tris (4-hydroxyphenyl) ethane, 1,1,1-tris (3,5-dimethyl-4-hydroxyphenyl) ethane, 2,6-bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, and 4- {4- [1,1-bis (4- Preferable examples include trisphenol such as hydroxyphenyl) ethyl] benzene} -α, α-dimethylbenzylphenol. Of these, 1,1,1-tris (4-hydroxyphenyl) ethane is preferred. The structural unit derived from such a polyfunctional compound is preferably 0.05 to 1 mol% in a total of 100 mol% with the structural units derived from other divalent components. The more preferable lower limit and upper limit of this range are as described above. Further, the branched structural unit may be derived not only from a polyfunctional compound but also from a polyfunctional aromatic compound such as a side reaction during a melt transesterification reaction. The ratio of such a branched structure can be calculated by ¹ H-NMR measurement.

  The a component polycarbonate includes polyester carbonate copolymerized with an aromatic or aliphatic (including alicyclic) bifunctional carboxylic acid. The aliphatic bifunctional carboxylic acid is preferably α, ω-dicarboxylic acid. Examples of aliphatic difunctional carboxylic acids include sebacic acid (decanedioic acid), dodecanedioic acid, tetradecanedioic acid, octadecanedioic acid, and linear saturated aliphatic dicarboxylic acids such as icosanedioic acid, and cyclohexanedicarboxylic acid. Preferred are alicyclic dicarboxylic acids such as acids.

  The viscosity average molecular weight (M) of the polycarbonate can be appropriately adjusted to satisfy the condition (II) of the constitution (1) of the present invention, but can be preferably in the range of 10,000 to 60,000. A polycarbonate having a viscosity average molecular weight of 25,000 or less can satisfy the condition (II) by mixing with another high molecular weight polymer as described above.

The viscosity average molecular weight of the polycarbonate is first determined by using an Ostwald viscometer from a solution in which 0.7 g of polycarbonate is dissolved in 100 ml of methylene chloride at 20 ° C., with a specific viscosity (η _SP ) calculated 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]
The viscosity average molecular weight M is calculated from the determined specific viscosity (η _SP ) by the following formula.
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

<Ingredients other than component a>
In addition to the above-mentioned light diffusing agent, various additives can be appropriately blended with the polycarbonate resin material which is the component A of the present invention, and these utilize various additives known to be blended with polycarbonate. be able to.

(I) Release agent A release agent can be mix | blended with A component of this invention as needed, and it is preferable to mix | blend. In the shape-extrusion method, a release agent having good releasability and less adhesion to and deposition on a roll is required.
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 mold release agent is preferably 0.005 to 1% by weight, more preferably 0.01 to 0.3% by weight, still more preferably 0.03 to 0.2% by weight, in 100% by weight of component A. Preferably it is 0.07 to 0.15 weight%. If the addition amount is less than the lower limit of the above range, the release property is not sufficiently improved. If the addition amount exceeds the upper limit, depending on the type of the release agent, light diffusibility, roll contamination, etc. are likely to be adversely affected.

  Among these, fatty acid esters are preferred as a 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, 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 them, the aliphatic carboxylic acid preferably has 14 to 20 carbon atoms. 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. In the production of the fatty acid ester of the present invention, an aliphatic carboxylic acid produced from such natural fats and oils and in the form of a mixture containing other carboxylic acid components can be used. The acid value in the fatty acid ester is preferably 20 or less (can take substantially 0). 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.

(Ii) Phosphorus stabilizer It is preferable that the polycarbonate resin material of the present invention is further blended with various phosphorous stabilizers mainly for the purpose of improving the thermal stability during the molding process. 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 monoorthoxenyl 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 material of the present invention contains a hindered phenol stabilizer mainly for the purpose of improving the heat stability, heat aging resistance, and ultraviolet resistance during molding. Can be blended. 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 (ii) phosphorus stabilizer and (iii) hindered phenol antioxidant is preferably 0.0001 to 1% by weight, more preferably 0.001% in 100% by weight of the polycarbonate resin material (component A). 001 to 0.1% by weight, more preferably 0.005 to 0.1% by weight. If the amount of the stabilizer is too small, it is difficult to obtain a good stabilizing effect. If the amount exceeds the above range, the physical properties of the material may be deteriorated or roll contamination may occur. .

  In the polycarbonate resin material of the present invention, an antioxidant other than the hindered phenol antioxidant can be used in order to further stabilize the hue at the time of heat treatment of the molded product. 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% by weight in 100% by weight of component A.

(Iv) Ultraviolet Absorber The polycarbonate resin sheet of the present invention preferably contains an ultraviolet absorber to improve weather resistance and cut harmful ultraviolet rays. Specific examples of the ultraviolet absorber of the present invention include, for example, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4 in the benzophenone series. -Benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfoxytrihydridolate benzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2, 2 ′, 4,4′-tetrahydroxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,2′-dihydroxy-4,4′-dimethoxy-5-sodiumsulfoxybenzophenone, bis (5-Benzoyl-4-hydroxy-2- Examples include methoxyphenyl) methane, 2-hydroxy-4-n-dodecyloxybenzophenone, and 2-hydroxy-4-methoxy-2′-carboxybenzophenone.

  Specific examples of the ultraviolet absorber include, for example, 2- (2-hydroxy-5-methylphenyl) benzotriazole and 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole in the benzotriazole series. 2- (2-hydroxy-3,5-dicumylphenyl) phenylbenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2,2′- Methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2-hydroxy-3,5-di-tert-butylphenyl) ) Benzotriazole, 2- (2-hydroxy-3,5-di-tert-butylphenyl) -5-chlorobenzotriazol 2- (2-hydroxy-3,5-di-tert-amylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-5- tert-butylphenyl) benzotriazole, 2- (2-hydroxy-4-octoxyphenyl) benzotriazole, 2,2'-methylenebis (4-cumyl-6-benzotriazolephenyl), 2,2'-p -Phenylenebis (1,3-benzoxazin-4-one), and 2- [2-hydroxy-3- (3,4,5,6-tetrahydrophthalimidomethyl) -5-methylphenyl] benzotriazole, and 2- (2'-Hydroxy-5-methacryloxyethylphenyl) -2H-benzotriazole and co-polymerized with the monomer 2 such as a copolymer with a possible vinyl monomer and a copolymer of 2- (2′-hydroxy-5-acryloxyethylphenyl) -2H-benzotriazole with a vinyl monomer copolymerizable with the monomer Examples include polymers having a -hydroxyphenyl-2H-benzotriazole skeleton.

  Specific examples of the ultraviolet absorber include 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-hexyloxyphenol and 2- (4) in hydroxyphenyltriazine series. , 6-Diphenyl-1,3,5-triazin-2-yl) -5-methyloxyphenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-ethyloxy Phenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-propyloxyphenol, and 2- (4,6-diphenyl-1,3,5-triazine-2- Yl) -5-butyloxyphenol and the like. Further, the phenyl group of the exemplified compound such as 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -5-hexyloxyphenol is 2,4-dimethyl. Examples of the compound are phenyl groups.

  As the ultraviolet absorber, specifically, in the cyclic imino ester type, for example, 2,2′-p-phenylenebis (3,1-benzoxazin-4-one), 2,2 ′-(4,4′-diphenylene) ) Bis (3,1-benzoxazin-4-one), 2,2 ′-(2,6-naphthalene) bis (3,1-benzoxazin-4-one) and the like.

  Further, as the ultraviolet absorber, specifically, for cyanoacrylate, for example, 1,3-bis-[(2′-cyano-3 ′, 3′-diphenylacryloyl) oxy] -2,2-bis [(2- Examples include cyano-3,3-diphenylacryloyl) oxy] methyl) propane and 1,3-bis-[(2-cyano-3,3-diphenylacryloyl) oxy] benzene.

  Furthermore, the ultraviolet absorber has a structure of a monomer compound capable of radical polymerization, so that the ultraviolet absorbing monomer and / or the light-stable monomer and a single amount of an alkyl (meth) acrylate or the like. It may be a polymer type ultraviolet absorber copolymerized with a body. Preferred examples of the ultraviolet absorbing monomer include compounds containing a benzotriazole skeleton, a benzophenone skeleton, a triazine skeleton, a cyclic imino ester skeleton, and a cyanoacrylate skeleton in the ester substituent of (meth) acrylic acid ester. The

  Among them, benzotriazole and hydroxyphenyltriazine are preferable from the viewpoint of ultraviolet absorbing ability, and cyclic imino ester and cyanoacrylate are preferable from the viewpoint of heat resistance and hue (transparency). You may use the said ultraviolet absorber individually or in mixture of 2 or more types.

  The blending amount of the ultraviolet absorber is preferably 0.01 to 2% by weight, more preferably 0.03 to 2% by weight, still more preferably 0.02 to 1% by weight, and particularly preferably 0 in 100% by weight of the component A. 0.05 to 0.5% by weight.

(V) Light stabilizer The polycarbonate resin material of the present invention includes bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and bis (1,2,2,6,6-pentamethyl-4- Piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2,6,6-pentamethyl-4 -Piperidyl) -1,2,3,4-butanetetracarboxylate, poly {[6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl ] [(2,2,6,6-tetramethylpiperidyl) imino] hexamethylene [(2,2,6,6-tetramethylpiperidyl) imino]}, and polymethylpropyl 3-oxy- [4- ( A hindered amine-based light stabilizer represented by 2,2,6,6-tetramethyl) piperidinyl] siloxane and the like can also be included.

  The light stabilizers may be used alone or in a mixture of two or more. The amount of the light stabilizer used is preferably 0.0005 to 3% by weight, more preferably 0.01 to 2% by weight, and still more preferably 0.02 to 1% by weight, in 100% by weight of component A.

(Vi) Blueing agent The polycarbonate resin material of the present invention can be blended with a blueing agent in order to counteract the yellowness of the sheet based on the resin or the ultraviolet absorber. Any bluing agent can be used without any problem as long as it is used for a resin. In general, anthraquinone dyes are preferred because they are readily available.

Specific examples of the bluing agent include the general name Solvent Violet 13 [CA. No. (Color Index No.) 60725; Trade names “Macrolex Violet B” manufactured by Bayer, “Diaresin Blue G” manufactured by Mitsubishi Chemical Corporation, “Sumiplast Violet B” manufactured by Sumitomo Chemical Co., Ltd.], general name Solvent Violet 31 [CA. No. 68210; Trade name “Diaresin Violet D” manufactured by Mitsubishi Chemical Corporation], generic name Solvent Violet 33 [CA. No. 60725; Trade name “Diaresin Blue J” manufactured by Mitsubishi Chemical Corporation], generic name Solvent Blue 94 [CA. No. 61500; trade name “Diaresin Blue N” manufactured by Mitsubishi Chemical Corporation, generic name Solvent Violet 36 [CA. No. 68210; Trade name “Macrolex Violet 3R” manufactured by Bayer, Inc., generic name Solvent Blue 97 [trade name “Macrolex Violet RR” manufactured by Bayer, Inc.] and generic name Solvent Blue 45 [CA. No. 61110; trade name “Tetrazole Blue RLS” manufactured by Sand Corp.] is a typical example. These bluing agents are preferably blended at a ratio of 0.3 × 10 ⁻⁴ to 2 × 10 ⁻⁴ wt% in 100 wt% of component A.

(Vii) Fluorescent Dye Since the polycarbonate resin material of the present invention has good transparency, it further imparts higher light transmittance and natural transparency by including a fluorescent brightening agent, and fluorescent whitening. By including an agent or a fluorescent dye that emits light other than that, it is possible to impart a design effect utilizing the luminescent color.

  Examples of the fluorescent dye (including a fluorescent brightening agent) used in the present invention include a coumarin fluorescent dye, a benzopyran fluorescent dye, a perylene fluorescent dye, an anthraquinone fluorescent dye, a thioindigo fluorescent dye, and a xanthene fluorescent dye. And xanthone-based fluorescent dyes, thioxanthene-based fluorescent dyes, thioxanthone-based fluorescent dyes, thiazine-based fluorescent dyes, and diaminostilbene-based fluorescent dyes. Among these, coumarin fluorescent dyes, benzopyran fluorescent dyes, and perylene fluorescent dyes are preferable because they have good heat resistance and little deterioration during molding of the polycarbonate resin. The blending amount of the fluorescent dye (including the fluorescent brightening agent) is preferably 0.0005 to 1% by weight, more preferably 0.0005 to 0.5% by weight, more preferably 100% by weight of the polycarbonate resin (component A). Preferably it is 0.001 to 0.1 weight%. Within such a range, better UV resistance and hue, thermal stability and light transmittance are compatible.

(Viii) Antistatic agent The polycarbonate resin material of the present invention may require antistatic performance (for example, to prevent adhesion of dust during printing). In such a case, it is preferable to include an antistatic agent. Examples of the antistatic agent include (i) an organic sulfonic acid phosphonium salt such as an aryl sulfonic acid phosphonium salt represented by (i) dodecylbenzenesulfonic acid phosphonium salt, and an alkyl sulfonic acid phosphonium salt, and a tetrafluoroboric acid phosphonium salt. Examples thereof include phosphonium borate salts. The phosphonium salt has an appropriate composition ratio of 5% by weight or less in 100% by weight of component A, preferably 0.05 to 5% by weight, more preferably 1 to 3.5% by weight, and 1.5 to 3% by weight. % Range is more preferred.

  Examples of the antistatic agent include (ii) lithium organic sulfonate, organic sodium sulfonate, organic potassium sulfonate, cesium organic sulfonate, rubidium organic sulfonate, calcium organic sulfonate, magnesium organic sulfonate, and barium organic sulfonate. Organic sulfonate alkali (earth) metal salts of Specifically, for example, metal salts of dodecylbenzenesulfonic acid, metal salts of perfluoroalkanesulfonic acid, and the like are exemplified. The organic sulfonate alkali (earth) metal salt has an appropriate composition ratio of 2% by weight or less in 100% by weight of component A, preferably 0.001 to 1.5% by weight, more preferably 0.005 to 1% by weight. preferable. In particular, alkali metal salts such as potassium, cesium, and rubidium are preferable.

  Examples of the antistatic agent include (iii) organic sulfonic acid ammonium salts such as alkyl sulfonic acid ammonium salt and aryl sulfonic acid ammonium salt. The composition ratio of the ammonium salt is 0.05% by weight or less in 100% by weight of the component A. Examples of the antistatic agent include (iv) a polymer containing a poly (oxyalkylene) glycol component such as polyether ester amide as a constituent component. The polymer is suitably 5% by weight or less in 100% by weight of component A.

(Ix) Compound having heat ray absorbing ability In the polycarbonate resin material of the present invention, a compound having heat ray absorbing ability in an amount that does not impair the object of the present invention can be used. Examples of the compound include phthalocyanine-based near-infrared absorbers, metal oxide-based near-infrared absorbers such as ATO, ITO, iridium oxide and ruthenium oxide, and metal boride-based near infrared rays such as lanthanum boride, cerium boride and tungsten boride. Preferred examples include various metal compounds having excellent near-infrared absorption ability such as an absorber, and carbon filler. Examples of carbon fillers include carbon black, graphite (including both natural and artificial, and whiskers), carbon fibers (including those produced by vapor phase growth), carbon nanotubes, and fullerenes, preferably carbon. Black and graphite. These can be used alone or in combination of two or more. The phthalocyanine near-infrared absorber is preferably 0.0005 to 0.2 parts by weight, more preferably 0.0008 to 0.1 parts by weight, and further 0.001 to 0.07 parts by weight in 100% by weight of component A. preferable. The metal oxide near-infrared absorber, metal boride-based near infrared absorber and carbon filler are preferably in the range of 0.1 to 200 ppm (weight ratio) in the resin composition of the present invention, and in the range of 0.5 to 100 ppm. Is more preferable.

(X) Other dyes and pigments In the polycarbonate resin material of the present invention, various dyes and pigments are used in addition to the bluing agent and the fluorescent dye within a range in which the effects of the invention are exerted, for example, an optical function having wavelength selectivity. It can be a member. In particular, a dye is preferable because it does not impair the transparency. As dyes, perylene dyes, coumarin dyes, thioindigo dyes, anthraquinone dyes, thioxanthone dyes, ferrocyanides such as bitumen, perinone dyes, quinoline dyes, quinacridone dyes, dioxazine dyes, isoindo Examples thereof include linone dyes and phthalocyanine dyes. The amount of these dyes used is preferably 0.0001 to 0.2% by weight and more preferably 0.0005 to 0.05% by weight in 100% by weight of component A.

  In the polycarbonate resin material of the present invention, an amount of flame retardant that does not impair the object of the present invention can be used. Examples of the flame retardant include brominated epoxy resin, brominated polystyrene, brominated polycarbonate, brominated polyacrylate, monophosphate compound, phosphate oligomer compound, phosphonate oligomer compound, phosphonitrile oligomer compound, phosphonic acid amide compound, sulfonate salt Organic acid metal salts represented by the above, silicone flame retardants, and the like, and one or more of them can be used. Each of these flame retardants can be blended in a known amount relative to the polycarbonate resin. The a-i component and the a-ii component, which are preferred a components of the present invention, exhibit an excellent effect on flame retardancy, and are therefore preferable because of their synergistic effects. In particular, organic acid metal salts or silicone flame retardants, and combinations thereof are preferred. Suitable organic acid metal salts include, for example, alkali (earth) metal perfluoroalkyl sulfonates, alkali (earth) metal aromatic sulfonates, and aromatic compounds disclosed in JP-A-2007-031583. Examples thereof include alkali (earth) metal salts of imides and polymers of sulfonic acid metal salts disclosed in JP-A-2008-214642. Preferred examples of the silicone flame retardant include silicone compounds containing an aromatic group disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-031583 and Japanese Patent Application Laid-Open No. 2008-094904. As for the organic acid metal salt flame retardant, a composition ratio of 2% by weight or less is appropriate in 100% by weight of component A, preferably 0.001 to 1.5% by weight, more preferably 0.005 to 1% by weight. . A silicone type flame retardant is 0.1 to 7 weight% in 100 weight% of A component, Preferably it is 0.5 to 5 weight%.

  In the polycarbonate resin material of the present invention, other polymers can be blended as long as the object of the present invention is not impaired. Other polymers include, for example, various olefinic polymers and copolymers such as polyethylene (including various copolymers such as LLDPE) and polypropylene (including modified polymers and copolymers such as maleic anhydride modified and various graft modified), polystyrene. Styrene-based polymers such as acrylonitrile-styrene copolymer, maleic anhydride-styrene copolymer, methyl methacrylate-styrene copolymer, styrene-isoprene copolymer, and phenyl methacrylate-styrene copolymer, polymethyl methacrylate and its copolymer, polyamide, polyethylene terephthalate, polybutylene Terephthalate, polyethylene naphthalate, cyclohexanedimethanol (CHDM) copolymer polyethylene Aromatic polyester such as phthalate and polyarylate, aliphatic polyester such as polylactic acid, polyurethane, polysulfone, polyethersulfone, cyclic polyolefin, polyetherimide, polyamideimide, polyimide, polyaminobismaleimide, polyetheretherketone, epoxy Examples thereof include resins and phenoxy resins. Such other polymer is preferably 20% by weight or less, more preferably 10% by weight or less in 100% by weight of component A. Further, various inorganic fillers, antibacterial agents, photocatalytic antifouling agents, white pigments for high light reflection, photochromic agents and the like may be appropriately blended with the polycarbonate resin material of the present invention.

<About the production method of polycarbonate resin material>
The polycarbonate resin material for forming the resin sheet of the present invention is a method in which the material is once pelletized and shaped extrusion is performed, and a method in which components constituting the material are supplied to an extruder performing the shaped extrusion and uniformized Either of these can be adopted. As the extruder, both a single screw extruder and a twin screw extruder can be used. In the case of the method of once pelletizing, it is preferable to use a twin screw extruder capable of better kneading.

  Furthermore, as an extruder, what has a vent which can deaerate the water | moisture content in a raw material and the volatile gas generate | occur | produced from melt-kneading resin can be used preferably. From the vent, a vacuum pump is preferably installed for efficiently discharging generated moisture and volatile gas to the outside of the extruder. It is also possible to remove a foreign substance from the resin composition by installing a screen for removing the foreign substance mixed in the extrusion raw material in the zone in front of the extruder die. Examples of such a screen include a wire mesh, a screen changer, a sintered metal plate (such as a disk filter), and the like.

  Furthermore, the method of supplying the component A and other additives (simply referred to as “additives” in the following examples) to the extruder is not particularly limited, but the following methods are typically exemplified. (I) A method in which the additive is fed into the extruder independently of the component A resin. (Ii) A method in which the additive and the resin powder of component A are premixed using a mixer such as a super mixer and then supplied to the extruder. (Iii) A method in which an additive and component A resin are previously melt-kneaded to form a master pellet. Such a feeding method to an extruder is applied to both a pelletizing extruder and an extruder performing shape extrusion.

  One of the methods (ii) is a method in which all necessary raw materials are premixed and supplied to the extruder. Another method (ii) is a method in which a master agent containing a high concentration of additives is prepared, and the master agent is independently or further premixed with the remaining resin and then supplied to the extruder. is there. The master agent can be selected from either a powder form or a form obtained by compressing and granulating the powder. Examples of other premixing means include a Nauter mixer, a V-type blender, a Henschel mixer, a mechanochemical device, and an extrusion mixer. Since the polycarbonate resin sheet of the present invention often requires high optical performance, it is preferable to clean the atmosphere around the extruder. Furthermore, in the production of such pellets, various methods already proposed in optical sheet extrusion of polycarbonate resin or cyclic polyolefin resin can be applied.

  The polycarbonate resin sheet of the present invention has an excellent light diffusion function, as described above, various illumination covers, light diffusion sheets for image display devices such as liquid crystal display devices, diffusion sheets for various instruments such as automobile meters, various nameplates, resin windows It can be used for a wide range of applications such as glass, image reading devices, and transmission screens. In particular, the image display device, the instrument, and the object for the purpose are effective in saving power by reducing the number of light sources, increasing the accuracy and brightness of the image display device, and making the light source represented by an LED a point light source. It can be suitably used for an indicator such as a blinker. In particular, it is suitable for a light diffusion sheet of a direct backlight type for a liquid crystal display or a liquid crystal television. Furthermore, it is useful for various applications such as various electronic / electrical equipment, OA equipment, exterior parts for vehicles, interior parts for vehicles, machine parts, other agricultural materials, fishery materials, transport containers, packaging containers and miscellaneous goods. Applications other than the light diffusion sheet for display devices include, for example, electric lamp covers, meters, signboards (particularly internally lit), resin window glass, image reading devices, vehicle roofing materials, ship roofing materials, residential roofing materials and Examples include a solar cell cover. As described above, the polycarbonate resin sheet of the present invention makes it possible to stably produce a light diffusing sheet applicable to an extremely wide range of uses by a shaping extrusion method, and its industrial effect is exceptional. .

It is the schematic which shows an example of the manufacturing apparatus of the light-diffusion sheet by the shape extrusion method in this invention. FIG. 2 is a diagram showing the holding angle θ with respect to the second roll (die with roll) in the cooling step. It is a simplification figure of the evaluation apparatus of the light-diffusion sheet used for the Example and the comparative example. It is a simplified diagram (graph) of measured luminance data. It is a cross-sectional simplified view of the shaping roll A used for producing a light-diffusion sheet in an Example and a comparative example. It is a cross-sectional simplified view of the shaping roll B used for producing the light-diffusion sheet in an Example and a comparative example. It is a graph which shows the shear rate dependence of the melt viscosity of the resin material used by Example 1 and the comparative example 1 measured with the capillary rheometer, and the value of each log ((eta) ₁ / (eta) ₂ ).

  The following examples further illustrate the present invention. The evaluation items and methods are as follows.

(1) Melt viscosity measurement: The obtained light diffusion sheet was cut into about 3 mm square and dried at 120 ° C. for 6 hours using a hot air dryer, and then a capillary rheometer (Capillograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.) Was measured at 280 ° C. under the conditions of barrel inner diameter: 9.55 mm, capillary length: 10.1 mm, and capillary inner diameter: 1.0 mm. The measurement was performed by changing the piston speed to 0.5, 1, 2, 5, 10, 20, 30, 50, 75, 100, 200, 300, 500, and 1000 mm / min in order, and from the detected load, the melt viscosity Was calculated. Here, the piston speed: 0.5 mm / min corresponds to the shear rate: 6.08 sec- ¹ , and the piston speed: 5 mm / min corresponds to the shear rate: 60.8 sec- ¹ . Than this, the shear rate of the material: 6.08 seconds melt viscosity eta ₂ calculated in the melt viscosity eta ₁ and a shear rate of 60.8 sec ^{-1 -1,} the melt viscosity ratio of the formula (1) log (η ₁ / η ₂ ) was calculated.

  (2) Calculation of convex height, convex width, and variation rate (α): A total of 19 samples having a width of 5 mm and a length of 10 mm are obtained by applying the obtained light diffusion sheet (width: 1,000 mm) in the width direction. (For example, in a portion 50 mm from the end, a portion 50 to 55 mm is cut from the end). A cross section perpendicular to the length direction of the light diffusion sheet was cut out from the small piece with a microtome. From the SEM observation of the cross section, the height and width of the formed convex shape were determined. From the obtained height and width, the number average value and the fluctuation rate α represented by the formula (2) were obtained.

  (3) Calculation of cross-sectional area Q: A convex contour shape was copied from JIS standard A4 fine paper from the SEM observation photograph, the paper was carefully cut along the contour shape, and its weight was measured. The contour shape in which the groove shape of the roll was drawn at the same magnification was copied on the same high-quality paper, and the same was cut out and the weight was measured. Assuming that the former weight corresponds to Q and the latter weight corresponds to P, the ratio of Q to P (whether or not the expression (3) is satisfied) was calculated. The table shows the maximum value and the minimum value among the magnitudes of Q with respect to P.

(4) Front luminance: A light diffusion sheet having a length of 318 mm and a width of 418 mm was cut out from the obtained light diffusion sheet so that the length direction of the light diffusion sheet was the horizontal direction. Therefore, the lens ridge shape of the light diffusion sheet is arranged in parallel in the lateral direction. The cut light diffusing sheet was incorporated into a 20-inch type direct backlight unit having cold cathode tubes arranged in parallel at intervals of 20 mm in the long side direction as a light source so that the distance from the light source was 15 mm. . Using the intersection of the diagonal lines of the diffusion sheet as the center of the diffusion sheet, the luminance (cd / m ² ) in the range of 100 mm in the vertical direction from the center is measured with a luminance meter BM-7 manufactured by Topcon Corporation at intervals of 2 mm. did. An evaluation apparatus is shown in FIG. The evaluation of luminance was performed by superimposing the following luminance enhancement films. The brightness enhancement film is composed of three films: diffusion film: Kimoto DX2, prism film: BEF-II, diffusion film: Kimoto DX2, each of which has a shaping surface on the liquid crystal side and the prism stripe direction. Evaluation was made in an arrangement parallel to the cold cathode tube.

  (5) Luminance fluctuation range: Using the luminance data obtained from “(4) Front luminance measurement”, the luminance fluctuation range was obtained by the following procedure. First, among the positions showing the maximum value of luminance, a total of three points are obtained: the position closest to the center of the diffusion sheet and the positions before and after the position. Next, the positions of the two minimum values existing between the three maximum values are obtained. FIG. 4 shows the positional relationship between the maximum value and the minimum value. A difference is calculated by subtracting the number average value of two local minimum values from the number average value of three local maximum values. A value obtained by dividing the difference by the number average value of the three maximum values was displayed in% as a fluctuation range (see FIG. 4).

  (6) Luminance non-uniformity: When the fluctuation range calculated in “(5) Luminance fluctuation range” is 3% or less, “◎” is greater than 3% and 6% or less, and “X” is 6% or more. evaluated.

(7) Appearance: The obtained light diffusing sheet was cut at 100 mm at both ends with a width of 1,000 mm to obtain a light diffusing sheet having a length of 400 mm and a width of 800 mm. Therefore, the lens bowl shapes are arranged in parallel in the vertical direction. The appearance of the light diffusing sheet was visually observed. Evaluation was performed according to the following criteria. I.e., the appearance of defects is not recognized (shaping unevenness may not be observed actual area 1 mm ² or more defects) ◎, shaping unevenness is not observed but actual area 1 mm ² or more defects were observed A thing was shown as ○, and a thing with irregular shaping was seen as x. In the appearance observation, a light diffusion sheet is installed so that the shaping surface is in the observation surface and the lens ridge shape is in the vertical direction, and parallel to the lateral direction of the sheet at a position 2 m above the sheet normal direction. A fluorescent tube was installed. In this state, the uniformity of the appearance was determined by observing the reflection state of the fluorescent tube light source over the entire region in the lateral direction of the sheet from angles of +45 degrees and −45 degrees with respect to the sheet normal. If irregular shaping or defects are recognized, this is reflected as image distortion.

[Example 1]
[Production method of diffusion sheet]
Branched polycarbonate “PC-B” produced by the production method shown below: 99.90 parts by weight and a light diffusing agent [Mostive Performance Materials Tospearl (registered trademark) 120, weight average particle size 2 μm] 02 parts by weight, fluorescent brightener [Kayalite OS manufactured by Nippon Kayaku Kogyo Co., Ltd.] 0.02 part by weight, trimethyl phosphate [TMP manufactured by Daihachi Chemical Co., Ltd.] 0.01 part by weight, phosphonite heat stabilizer (Manufactured by Clariant: Sandstub P-EPQ (trade name)) 0.05 parts by weight were mixed in advance with a Nauta mixer, and the extruder temperature was 280 ° C. using a vented T-die single screw extruder with a screw diameter of 120 mmφ. T-die temperature is 280 ° C., the vacuum degree of the vent is kept at 26.6 kPa, and a 1.5 mm thick polycarbonate resin light diffusion sheet is melt-pressed. I put it out. The width of the T die was 1,200 mm, and the width was about 1,100 mm during roll forming by necking between the air gaps. The flow rate Q was 80 cm ³ / sec. Shape extrusion was performed 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. The second roll (width 1,600 mm) was formed with a V-shaped groove having the following shape, and was shaped over the entire width of the sheet. As shown in FIG. 5, the V-shaped groove has an elliptical arc shape cut by a line segment perpendicular to the major axis at a position 160 μm from the intersection of the major axis of the ellipse having a major axis of 720 μm and a minor axis of 240 μm and the ellipse. It was. The pitch between the V grooves was 200 μm. Such a shaping roll is shown as “roll A” in Table 1. The roll temperature is a first roll: 95 ° C., a second roll: 95 ° C., and a third roll: 125 ° C., and a speed ratio V ₁ between the peripheral speed V ₁ of the first roll and the peripheral speed V ₂ of the second roll. / _{V 2} was 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. The holding angle on the second roll was 180 degrees. Finally, about 50 mm at both ends of the sheet were cut to produce a light diffusion sheet having a width of 1,000 mm. The evaluation results are shown in Table 1, and data on the shear rate dependence of the melt viscosity are shown in FIG.

(Production method of branched polycarbonate “PC-B”)
A reactor equipped with a thermometer, a stirrer, and a reflux condenser was charged with 2867 parts by weight of ion-exchanged water, 1105 parts by weight of 25% aqueous sodium hydroxide, and 1 part by weight of hydrosulfite, and 750 parts by weight of bisphenol A was dissolved under stirring. 2252 parts by weight of methylene chloride was added, and 370 parts by weight of phosgene was blown at 20 ° C. over about 40 minutes to obtain a polycarbonate oligomer.

  To this reaction mixture, 159.6 parts by weight of 11% strength p-tert-butylphenol in methylene chloride was added, and then 1,1,1-tris (4-hydroxyphenyl) was added to 5% strength by weight aqueous sodium hydroxide solution. ) After adding 55.9 parts by weight (0.28 mol%) of an aqueous solution of ethane dissolved at a concentration of 5% by weight and 118.3 parts by weight of an aqueous solution of 48.5% by weight sodium hydroxide, the mixture was vigorously stirred and highly emulsified. The reaction was completed by standing for 3 hours. After completion of the reaction, 9000 parts by weight of methylene chloride was added to dilute, then the methylene chloride phase was separated from the reaction mixture, 8000 parts by weight of ion-exchanged water was added to the methylene chloride phase and mixed with stirring. The phase and the organic phase were separated. This operation was repeated four times until the conductivity of the aqueous phase was almost the same as that of ion-exchanged water.

  Next, 100 L of ion-exchanged water was added to a 1000 L kneader, and the organic phase (organic solvent solution) obtained at a water temperature of 42 ° C. was gradually added to the kneader to evaporate methylene chloride to obtain a granular material. Next, the mixture of the granular material and water is put into a hot water treatment tank with a stirrer controlled at a water temperature of 95 ° C., mixed at a weight ratio of 25 parts by weight of the granular material and 75 parts by weight of water, and stirred for 30 minutes. did. This mixture of powder and water was separated with a centrifuge to obtain a powder containing 0.5% by weight of methylene chloride and 45% by weight of water. Next, this granular material was continuously supplied at 50 kg / hr (in terms of polycarbonate resin) to a SUS316L conductive heat-receiving groove type biaxial stirring continuous dryer controlled at 140 ° C., and the condition of an average drying time of 3 hours And dried to obtain a powder. The resulting branched polycarbonate resin had a viscosity average molecular weight of 25,600 and the proportion of branched structural units derived from 1,1,1-tris (4-hydroxyphenyl) ethane was 0.28 mol%.

[Example 2]
A light diffusing sheet was produced under the same conditions as those described in Example 1 except that a roll having a V-shaped groove having the following shape was used as the second roll. The V-shaped groove of Example 2 had a prism shape with a width of 50 μm and a height of 25 μm and an inclination angle of 45 degrees, and the distance between the grooves was 2 μm. Such a shaping roll is shown as “roll B” in Table 1. The evaluation results are shown in Table 1.

[Example 3]
A light diffusion sheet was produced under the same conditions as described in Example 1 except that the following composition was used as the polycarbonate resin material and the sheet thickness was 2.5 mm. The composition of Example 3 is composed of 99.87 parts by weight of the above-mentioned branched polycarbonate “PC-B”, 0.02 parts by weight of brightening agent [Kayalite OS manufactured by Nippon Kayaku Kogyo Co., Ltd.], trimethyl phosphate [Daihachi TMP manufactured by Chemical Industry Co., Ltd.] 0.01 parts by weight, 0.05 parts by weight of phosphonite heat stabilizer [Sandstub P-EPQ (trade name) manufactured by Clariant, Inc.], and flame retardant [Megafac manufactured by DIC Corporation] F-114] 0.05 parts by weight, and these were mixed in advance by a Nauta mixer and charged into an extruder. The evaluation results are shown in Table 1.

[Example 4]
As the polycarbonate resin material, the same conditions as described in Example 1 were used except that the same composition as Example 2 was used as the shaping roll, and the sheet thickness was 0.9 mm. A light diffusion sheet was produced under the conditions. The composition of Example 4 comprises 99.92 parts by weight of the above-mentioned branched polycarbonate “PC-B”, 0.02 parts by weight of a brightening agent (Kayalite OS manufactured by Nippon Kayaku Kogyo Co., Ltd.), trimethyl phosphate [Daihachi Chemical Industry Co., Ltd. TMP] 0.01 parts by weight, and phosphonite heat stabilizer [Clariant Sandstub P-EPQ (trade name)] 0.05 parts by weight, these were mixed in advance by a Nauta mixer And put into an extruder. The evaluation results are shown in Table 1.

[Example 5]
A material comprising the same composition as in Example 1 was used except that the branched polycarbonate “PC-B” in Example 1 was changed to the high molecular weight component-containing polycarbonate “PC-U” shown below. Were subjected to extrusion extrusion under the same conditions as described above to produce a light diffusing sheet. The evaluation results are shown in Table 1.

(Manufacturing method of high molecular weight component-containing polycarbonate “PC-U”)
Two types of linear aromatic polycarbonate resins were synthesized from bisphenol A, p-tert-butylphenol as a terminal terminator, and phosgene by an interfacial polycondensation method using triethylamine as a catalyst. The viscosity average molecular weight of the first polycarbonate was 23,700 and the second was 120,000. 90 parts by weight of the first polycarbonate and 10 parts by weight of the second polycarbonate were mixed in methylene chloride to a concentration of about 10% by weight, and the solution was put into a kneader filled with water at a water temperature of 80 ° C. The solid was then powdered and the collected solid was dried with a hot air dryer at 120 ° C. To 100 parts by weight of the solid obtained after drying, 0.03 part by weight of a phosphonite heat stabilizer (manufactured by Clariant: Sandstub P-EPQ (trade name)) is added, pelletized using a single screw extruder, and viscosity Aromatic polycarbonate resin pellets having an average molecular weight of 30,500 were obtained.

[Example 6]
The conditions described in Example 1 except that the composition obtained by changing the branched polycarbonate “PC-B” of Example 1 to the above-described high molecular weight component-containing polycarbonate “PC-U” was used, and the sheet thickness was changed to 2 mm. The light diffusing sheet was manufactured by performing shape extrusion under the same conditions. The evaluation results are shown in Table 1.

[Example 7]
A composition obtained by changing the branched polycarbonate “PC-B” of Example 1 to a linear polycarbonate resin having a viscosity average molecular weight of 30,000 (Panlite (registered trademark) K-1300 manufactured by Teijin Chemicals Ltd.) is used. As described in Example 1, except that the same roll B as in Example 2 was used as the shaping roll, the sheet thickness was changed to 1.2 mm, and the extrusion temperature and the die temperature were each increased by 10 degrees from Example 1. A light diffusing sheet was produced under the same conditions as described above. The evaluation results are shown in Table 1.

[Example 8]
The branched polycarbonate “PC-B” of Example 1 was prepared by using the PC-B and a linear polycarbonate resin having a viscosity average molecular weight of 23,900 (Panlite (registered trademark) L-1250 manufactured by Teijin Chemicals Ltd.) A light diffusing sheet was produced under the same conditions as described in Example 1 except that the composition was changed to a mixture having a weight ratio of 6: 4. The evaluation results are shown in Table 1.

[Comparative Example 1]
Except for using a composition obtained by changing the branched polycarbonate PC-B of Example 1 to a linear polycarbonate resin having a viscosity average molecular weight of 23,900 (Panlite (registered trademark) L-1250 manufactured by Teijin Chemicals Ltd.). Produced a light diffusion sheet under the same conditions as described in Example 1. The evaluation results are shown in Table 1, and data on the shear rate dependence of the melt viscosity are shown in FIG.

[Comparative Example 2]
Using a composition obtained by changing the branched polycarbonate PC-B of Example 1 to a linear polycarbonate resin having a viscosity average molecular weight of 23,900 (Panlite (registered trademark) L-1250 manufactured by Teijin Chemicals Ltd.), and Except that the sheet thickness was changed to 2 mm, the shape-extrusion extrusion was performed under the same conditions as described in Example 1 to produce a light diffusion sheet. The evaluation results are shown in Table 1. The sheet resulted in uneven brightness due to its deflection.

DESCRIPTION OF SYMBOLS 1 1st roll of cooling roll 2 2nd roll of cooling roll 3 3rd roll of cooling roll 4 Melt bank 5 Melt extruded sheet-like resin 6 T die lip 7 Take-up roll 11 Center 12 of 1st roll circle 12 Center of the circle of the two rolls X Contact point of the second roll of the line connecting the center of the circle of the second roll and the center of the circle of the first roll Y Point where the extruded resin leaves the shaping roll as the second roll θ Holding angle 31 Luminance meter 32 Light diffusing sheet (Lens bowl shape parallel to cold cathode)
33 Cold cathode tube 34 Backlight unit 41 Schematic diagram of measured values of luminance (graph)
42 Maximum value 43 at a position closest to the center of the diffusion sheet 43 Maximum value 44 positioned before and after 42 Minimum value 51 positioned between maximum values Forming roll A
52 Elliptical arc V-shaped groove 53 Groove depth (160 μm)
54 Pitch between V grooves (200μm)
61 Shaping roll B
62 V-shaped groove width (50μm)
63 Groove depth (25μm)
64 Distance between grooves (2μm)
71 Horizontal axis: logarithmic coordinate 72 of shear rate (sec ⁻¹ ) Vertical axis: logarithmic coordinate 73 of melt viscosity (Pa · sec) Graph 74 of Example 1 Graph 75 of Comparative Example 1 Position of shear rate 6.08 sec ⁻¹ (Intersection with the graph is η ₁ (Pa · sec))
76 Position at a shear rate of 60.8 sec ⁻¹ (intersection with the graph is η ₂ (Pa · sec))
77 log (η ₁ / η ₂ ) in Example 1
78 log (η ₁ / η ₂ ) in Comparative Example 1

Claims (11)

The molten polycarbonate resin material (component A) is sandwiched between a shaping roll having a fine concave shape formed on the surface and a cooling roll facing the shaping roll, and the convex shape is shaped. A method for producing a polycarbonate resin sheet comprising:
(I) When the thickness of the sheet is 0.8 to 3 mm, the height of the convex shape is 20 to 300 μm, the height is H (μm), and the width of the convex shape is D (μm), H / D In manufacturing a sheet having a range of 0.3 to 1,
(II) As the component A, melt viscosity η ₁ at a shear rate of 6.08 seconds ⁻¹ and melt viscosity η ₂ at a shear rate of 60.8 seconds ⁻¹ measured at 280 ° C. with a capillary rheometer The manufacturing method characterized by using the polycarbonate resin material which satisfies following formula (1).
0.03 <log (η ₁ / η ₂ ) <0.5 (1)   The manufacturing method according to claim 1, wherein the shaped convex shape is a convex shape regularly arranged in a width direction of the sheet or / and a direction perpendicular to the width direction.   The manufacturing method according to claim 2, wherein the regularly arranged convex shapes are bowl-shaped lens shapes.   The manufacturing method according to claim 3, wherein the lens shape is a lenticular type, a prism type, or a linear Fresnel type. The regularly arranged convex shapes are regularly arranged in the width direction of the sheet, and when the fluctuation rate α of the convex height expressed by the following formula (2) is obtained over the width of the sheet, the fluctuation rate 5 is less than 5%, The manufacturing method of any one of Claims 2-4.
α (%) = 100 × (H _MAX −H _MIN ) / {(H _MAX + H _MIN ) ÷ 2} (2)
(Here, H _MAX indicates the maximum value of height and H _MIN indicates the minimum value.) The shaping roll has a regular groove shape in the circumferential direction or the width direction of the roll, and a transfer ratio of the groove-shaped sectional area P of the shaping roll to the transferred convex sectional area Q. Q / P exists in the range of following formula (3), The manufacturing method of any one of Claims 1-5.
0.3 <Q / P <0.95 (3)   The first roll, the second roll, and the third roll are arranged in this order, and the second roll is used as a shaping roll, and the first roll is used as a cooling roll facing the shaping roll. The manufacturing method as described in.   The polycarbonate (component a) in the component A is a polycarbonate comprising 0.05 to 1 mol% of a carbonate structural unit having a branched structure in 100 mol% of the carbonate structural unit, or a viscosity average molecular weight of 70, A polycarbonate (a-ii component) having a viscosity average molecular weight of 20,000 to 55,000, which is a mixture of a polycarbonate having a viscosity average molecular weight of 10,000 to 40,000 and a polycarbonate having a viscosity average molecular weight of 10,000 to 40,000. 8. The production method according to any one of 7 above.   The said A component is a manufacturing method of any one of Claims 1-8 containing 0.01-2 weight% of organic fine particles with an average particle diameter of 0.5-10 micrometers as a diffusing agent.   The polycarbonate resin sheet in which the convex shape manufactured from the manufacturing method of any one of the said Claims 1-9 was shaped.   The polycarbonate resin sheet according to claim 10, wherein the resin sheet is a light diffusion sheet.