JP2018141080A - Resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet that can be used as a substitute for checker glass or for other purposes, and is lighter than a glass product, has a light concealment property, and has an appropriate concealing property, and has an impact resistance. It is an object of the present invention to provide a resin sheet that is excellent and has a low risk of injury even if it breaks. SOLUTION: The resin sheet of the present invention uses a transparent thermoplastic resin as a base resin, and a plurality of grooves extending in one direction are formed on at least one surface of the resin sheet, and an arithmetic average is formed on the one surface. Fine irregularities having a height (Ra) of 5 to 60 μm are formed. [Selection] Figure 1

Description

  The present invention relates to a resin sheet on which fine irregularities are formed, and in particular, relates to a resin sheet that has both daylighting property, concealment property, and design property and can be used as a substitute for checker glass.

  The checker glass is also called waffle glass or mosaic glass, and is used for antique interior doors and furniture because of its excellent design and retro feeling. The checkered glass lattice pattern is formed by repeatedly forming hook-shaped patterns extending in one direction on one surface at equal intervals in the width direction so that the hook-shaped protrusions are repeated, It is formed by repeatedly forming a pattern extending in the direction perpendicular to the direction in which the pattern on the surface of the surface extends at equal intervals in the width direction to form a pattern in which the ridge-shaped projections are repeated. As a whole, the protrusion patterns overlap and appear as a lattice pattern.

  The checker glass is excellent in design, but because it is made of glass, it is not light enough, it is easily broken by impact, it is easy to break up when broken, and there is a risk of injury from broken pieces, cutting, polishing There is a problem that secondary processing such as bending is not easy.

  The present invention is a resin sheet that can be used as a substitute for checker glass and other applications, is lighter than glass products, has good concealing properties while having daylighting properties, has excellent impact resistance, and It is an object to provide a resin sheet that is less likely to be injured even if it breaks.

According to the present invention, the following resin sheet is provided.
[1] In a resin sheet using a transparent thermoplastic resin as a base resin, a plurality of grooves extending in one direction are formed on at least one surface of the resin sheet, and the surface on which the grooves are formed has an arithmetic average. A resin sheet having a roughened surface having fine irregularities having a height (Ra) of 5 to 60 μm.
[2] On the other surface of the resin sheet, a number of groove portions extending in the direction of an angle of 0 ° to 90 ° with respect to the extending direction of the groove portion formed on the one surface are formed, and the 0 ° The other surface on which the groove extending in the direction of the angle of ~ 90 ° is formed is a roughened surface having fine irregularities having an arithmetic average height (Ra) of 5 to 60 μm, 2. The resin sheet as described in 1 above.
[3] The other surface of the resin sheet is characterized in that a plurality of groove portions extending in a direction of an angle of 80 ° to 90 ° with respect to a direction in which the groove portion formed on the one surface extends are formed. The resin sheet according to 2 above.
[4] The resin sheet according to any one of 1 to 3, wherein the resin sheet has a total light transmittance of 80% or more and a parallel light transmittance of 60% or less.
[5] The pencil hardness on the roughened surface is H or more in a pencil hardness test in accordance with JIS K5600-5-4 (1999). The resin sheet of description.
[6] The resin sheet as described in any one of 1 to 5, wherein the arithmetic average height (Ra) is 30 to 60 μm.
[7] The resin sheet according to any one of 1 to 6, wherein a groove depth of the groove portion of the resin sheet is 300 to 1500 μm.
[8] The resin sheet according to any one of 1 to 7, wherein the basis weight of the resin sheet is 2000 to 9000 g / m ² .
[9] The resin sheet according to any one of 1 to 8, wherein the transparent thermoplastic resin is any one of a styrene resin, an acrylic resin, and a polycarbonate resin.

  In the resin sheet of the present invention, a large number of grooves extending in one direction are formed on at least one surface, and the arithmetic average height (Ra) is fine in a specific range on the surface on which the grooves are formed. In addition to being excellent in design properties due to the formation of irregularities, it has moderate concealing properties while having daylighting properties. In addition, since the resin sheet of the present invention is made of resin, it is lightweight and has excellent secondary processability such as cutting, polishing, bending, adhesion, etc., excellent impact resistance than glass products, Unlikely, debris is difficult to scatter and there is little risk of injury.

FIG. 1 is a perspective view showing an example of a resin sheet in which grooves and fine irregularities are formed only on one surface. Fig.2 (a) is a top view which shows an example of the resin sheet in which the groove part and the fine unevenness | corrugation were formed only in one surface, FIG.2 (b) is taken along the II line | wire of Fig.2 (a). It is a longitudinal cross-sectional view which follows. FIG. 3 is a perspective view showing an example of a resin sheet in which grooves and fine irregularities are formed on both sides. Fig.4 (a) is a top view which shows an example of the resin sheet in which the groove part and the fine unevenness | corrugation were formed in both surfaces, FIG.4 (b) is a vertical section along the II-II line | wire of Fig.2 (a) FIG. FIG. 5A is a perspective view showing an example of a mold, and FIG. 5B is a sectional view thereof. Fig.6 (a) is an enlarged photograph which shows an example of the roughened surface which has the fine unevenness | corrugation formed by blasting, The same (b) is the schematic diagram of the cross section. Fig.7 (a) is an enlarged photograph which shows an example of the roughened surface which has the fine unevenness | corrugation formed by embossing, and the same (b) is the schematic diagram of the cross section.

Hereinafter, the resin sheet of the present invention will be described in detail.
In the resin sheet 1 of the present invention, as shown in FIGS. 1, 2A, and 2B, a plurality of grooves 3a extending in one direction are formed on at least one surface 2a. By providing the groove part 3a, a strip-like pattern appears on the surface of the resin sheet 1, and the design is improved.

In the present invention, as shown in FIGS. 3, 4 (a), and 4 (b), the other surface 2 b of the resin sheet 1 extends in the direction in which the groove 3 a formed on the one surface 2 a extends. Thus, the groove 3b extending in the direction of the angle of 0 to 90 ° can be formed.
When the groove portion is formed in this way on the other surface, the geometric pattern formed by the groove portion 3a and the groove portion 3b appears on the surface of the resin sheet, so that the degree of freedom in design increases and the design is improved. . In each of the one surface and the other surface, the distance between the grooves extending in one direction is preferably constant, and more preferably the distance between the groove on one surface and the other surface is constant on both surfaces. More preferably, the distance between the grooves on one surface and the other surface is the same.
When the angle formed by the groove 3a on one surface and the groove 3b on the other surface is 0 ° to 10 °, the angle is substantially parallel, and the angle formed by the groove 3a on one surface and the groove 3b on the other surface is 30. When the angle is from 60 ° to 60 °, the shape is obliquely intersected, and when the angle formed by the groove portion 3a on one surface and the groove portion 3b on the other surface is 80 ° to 90 °, the shape is substantially orthogonal, It is preferable because it is excellent. From the viewpoint that a lattice-like pattern appears on the surface of the resin sheet and the design property is further excellent, the intersecting angle is more preferably 85 ° to 90 °, and particularly preferably 90 °.

Between the groove part 3 and the groove part 3 in the cross section of the resin sheet can be formed as a flat surface, but it is preferably formed as the convex part 4. As for the shape of the convex part 4, it is especially preferable that it is bowl shape. It is considered that the visibility of an object on the other side of the resin sheet can be reduced while maintaining the brightness (lighting property) of the light transmitted through the resin sheet when the convex portion is bowl-shaped. That is, it is considered that the parallel light transmittance can be lowered while maintaining the total light transmittance. In the case where the gap between the groove portions 3 and 3 in the cross section of the resin sheet is formed as a convex portion 4 and the angle formed by the groove portion 3a on one surface and the groove portion 3b on the other surface is substantially orthogonal, It is preferable because it is a resin sheet and is particularly excellent in design.
Hereinafter, the resin sheet of the aspect in which the bowl-shaped convex part 4 is formed adjacently and the trough part between the adjacent convex parts 4 is formed as a groove part is demonstrated.

1 is a perspective view of a resin sheet in which a groove portion is formed only on one surface, and a gap between adjacent groove portions is formed as a hook-shaped convex portion. FIG. 2A is a groove portion only on one surface. And FIG. 3B is a longitudinal sectional view taken along the line II of FIG. 2A, and FIG. 3 is one surface and the other surface. 4A is a perspective view of a resin sheet in which grooves are formed on both surfaces at an intersecting angle of 90 °, and a gap between adjacent grooves is formed as a ridge-shaped convex portion. FIG. And FIG. 4B is a plan view of the resin sheet in which grooves having a crossing angle of 90 ° and ridge-shaped protrusions are formed on the other surface. It is a longitudinal cross-sectional view which follows II line. In the figure, 1 is a resin sheet, 2a is one surface, 2b is the other surface, 3a is a groove formed on one surface, 3b is a groove formed on the other surface, and 3 is a groove. 4a is a bowl-shaped projection formed on one surface, 4b is a bowl-shaped projection formed on the other surface, 4 is a generic name of the bowl-shaped projection, and 5a is one 5b is a fine unevenness formed on the other surface, 5 is a generic name for the fine unevenness, and W (1) is an adjacent groove 3a formed on one surface. , W (2) is the distance between adjacent grooves 3b formed on the other surface, H (1) is the height of the convex portion 4a formed on one surface, H ( 2) shows the height of the convex part 4b formed in the other surface, respectively.

  The interval W between the adjacent groove portions 3 is preferably 5 to 30 mm, and more preferably 10 to 20 mm. When the width is within the above range, it is comfortable to the eye and has excellent design. The interval W (1) between the groove portions 4a formed on the one surface 2a and the interval W (2) between the groove portions 3b formed on the other surface 2b can be different, but from the viewpoint of design. Preferably they are the same size.

  When forming between the adjacent groove part 3 as the convex part 4, the groove depth H (1) of the groove part formed in one surface 2a and the groove depth H (2) of the groove part formed in the other surface 2b are: Although it can also be set as a different magnitude | size, it is preferable that it is the same magnitude | size from a viewpoint of design property.

  Although there is no restriction | limiting in the groove depth H of this groove part, it is preferable that it is 300-1500 micrometers. If the groove depth H is in the above range, the pattern of the convex portion 4 becomes clear and a resin sheet excellent in design can be obtained. From this viewpoint, the lower limit is preferably 350 μm, more preferably 400 μm. Moreover, the upper limit is preferably 1300 μm, more preferably 1000 μm, and still more preferably 800 μm.

  The space | interval of the groove part 3 and the groove depth H of the groove part 3 are measured by measuring the cut surface shape of the resin sheet surface using a surface roughness measuring machine. Examples of the surface roughness measuring machine include “Surface Roughness Measuring Machine Surfcoder SE1700α” manufactured by Kosaka Laboratory Ltd.

In the resin sheet of the present invention, the surface on which the groove 3a is formed is a roughened surface having fine irregularities 5a having an arithmetic average height (Ra) of 5 to 60 μm. Further, when the groove 3b is formed on the other surface as required, the surface on which the groove 3b is formed also has a rough surface having fine irregularities 5b having an arithmetic average height (Ra) of 5 to 60 μm. The resulting surface.
The roughened surface having the fine irregularities improves the concealing property while maintaining the brightness (lighting property) of the light transmitted through the resin sheet, so that the object on the other side of the resin sheet is improved. Visibility can be reduced. In general, the larger the arithmetic average height (Ra) within the range of the arithmetic average height (Ra), the smaller the parallel light transmittance tends to be, and the concealability tends to be improved, and the resin sheet surface is scratched. This can be suppressed. From the above viewpoint, the arithmetic average height (Ra) of the surface on one surface is preferably 30 to 60 μm, and the arithmetic average height (Ra) of the surface on both surfaces is more preferably 30 to 60 μm. . Furthermore, the surface of the resin sheet of the present invention on which the groove 3a is formed has an average length (Rsm) of roughness curve elements of preferably 300 to 1500 μm, more preferably 400 to 1300 μm, and 500 More preferably, it is ˜1100 μm.

  FIG. 6 and FIG. 7 show enlarged photographs of examples of roughened surfaces having fine irregularities 5a having an arithmetic average height (Ra) of 5 to 60 μm. FIG. 6A is an enlarged photograph of a roughened surface having fine irregularities 5 formed by blasting, and FIG. 6B is a schematic diagram of the cross section thereof. FIG. 7A is an enlarged photograph of the roughened surface having fine irregularities 5 formed by embossing, and FIG. 7B is a schematic diagram of the cross section thereof.

  The arithmetic average height (Ra) and the average length (Rsm) of the roughness curve element are measured based on JIS B0601-2013. Specifically, it can be measured using a surface roughness measuring machine. Examples of the surface roughness measuring device include a Kosaka Laboratories Co., Ltd., Surfcoder (model: SE1700α), and the like.

  From the viewpoint of scratch resistance of the resin sheet, the resin sheet surface preferably has a hardness of “H” or higher, more preferably a hardness of “2H” or higher, and a hardness of “3H” or higher in the pencil hardness test. It is further preferable to have Both surfaces of the resin sheet are preferably surfaces that satisfy the above-mentioned hardness. The pencil hardness test is defined by JIS K5600-5-4 (1999).

  The feature of the resin sheet of the present invention is that it has an appropriate concealing property even though it transmits light as much as the checker glass and is excellent in daylighting performance. The light transmittance is quantified by the total light transmittance. The total light transmittance represents the ratio of light transmitted through the resin sheet, and the larger the total light transmittance, the easier the light passes from the front side to the back side of the resin sheet. From this viewpoint, the total light transmittance is preferably 80% or more, and more preferably 85% or more. The upper limit is not limited, but is approximately 98%.

  The concealability is quantified by the parallel light transmittance that represents the ratio of light that enters the resin sheet and travels straight. It means that the smaller the parallel light transmittance is, the higher the concealing property is, and it is difficult to see the other side of the resin sheet. From this viewpoint, the parallel light transmittance is preferably 70% or less, more preferably 60% or less, still more preferably 50% or less, and particularly preferably 40% or less. The lower limit of the parallel light transmittance is preferably approximately 5%. From the viewpoint of achieving both daylighting and appropriate hiding properties, the resin sheet preferably has a total light transmittance of 80% or more and a parallel light transmittance of 60% or less. In the light transmittance, the total of the diffuse light transmittance and the parallel light transmittance is the total light transmittance.

  The total light transmittance, diffuse light transmittance, and parallel light transmittance can be measured using a turbidimeter (for example, Haze Meter NDH7000SP manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K7361-1: 1997. .

The basis weight of the resin sheet is preferably 2000~9000g / ^{m 2,} more preferably from 3000~8000g / ^{m 2,} further preferably 4000~6000g / ^{m 2.} If this basic weight is the said range, it can be set as the resin sheet which is excellent in lightweight property compared with a glass plate, and is easy to handle.
Since the resin sheet is excellent in secondary workability such as cutting, the vertical and horizontal dimensions can be appropriately changed depending on the intended use.

  As the transparent thermoplastic resin used in the present invention, a resin corresponding to “transparent plastic” described in JIS K7361 (1997) is preferably used. Specific examples of the transparent thermoplastic resin include polystyrene resin, polypropylene resin, acrylic resin, polycarbonate resin, thermoplastic polyester resin, and cyclic olefin resin. These may be used alone or in combination of two or more. used. Among these, since it is excellent in workability, it is preferably any of a polystyrene resin, an acrylic resin, and a polycarbonate resin. Acrylic resin is particularly preferable because it is excellent in scratch resistance when formed into a resin sheet.

  The polystyrene resin has a styrene-based unit or styrene component content of 50 mol% or more, preferably 70 mol% or more, and particularly preferably 80 mol% or more.

  The acrylic resin is composed of a homopolymer of acrylic acid alkyl ester and / or methacrylic acid alkyl ester (hereinafter collectively referred to as (meth) acrylic acid ester) or a co-polymer of (meth) acrylic acid esters. A polymer or a (meth) acrylic acid ester-based copolymer having a unit based on (meth) acrylic acid ester of 50 mol% or more and a unit based on another comonomer of 50 mol% or less, and two or more of these Such as a mixture. In addition, (meth) acrylic acid is the concept containing acrylic acid and methacrylic acid, and means one or both of these. Examples of the homopolymer or copolymer of the (meth) acrylic acid ester include, for example, polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polyethyl acrylate, Examples include methyl methacrylate-ethyl methacrylate copolymer, methyl methacrylate-butyl methacrylate copolymer, methyl methacrylate-ethyl acrylate copolymer, and the like. Among these, polymethyl methacrylate, polymethyl acrylate, methyl methacrylate-ethyl methacrylate copolymer, or methyl methacrylate-ethyl acrylate copolymer is preferable, and polymethyl methacrylate is more preferable.

  Examples of the (meth) acrylic acid ester copolymer include methyl methacrylate-styrene-butylene copolymer, (meth) methyl acrylate-styrene copolymer, (meth) ethyl acrylate-styrene copolymer. Or methyl methacrylate-acrylonitrile-butadiene-styrene copolymer and the like. Of these, methyl methacrylate-styrene-butylene copolymer or methyl methacrylate-styrene copolymer is preferred.

  Examples of the polycarbonate resin include bisphenol A (4,4′-dihydroxydiphenyl-2,2-propane) polycarbonate, bisphenol F (4,4′-dihydroxydiphenyl-2,2-methane) polycarbonate, and bisphenol S (4 , 4′-dihydroxydiphenylsulfone) polycarbonate, 2,2-bis (4-dihydroxyhexyl) propane) polycarbonate, and the like. Of these, optical grade polycarbonate resins are particularly preferred.

The density of the transparent thermoplastic resin used in the present invention is preferably 0.8~1.6g / cm ^3, more preferably 0.9~1.5g / cm ^3, 1~1. More preferably, it is ³ g / cm ³ . When the density of the transparent thermoplastic resin is within the above range, it is possible to obtain a resin sheet that is excellent in light weight and easy to handle as compared with a glass plate. In addition, the density of the float glass generally used as a glass product is about 2.5 g / cm < ³ >.

  Various additives can be added to the base resin of the resin sheet used in the present invention as long as the objective effects of the present invention are not impaired. Examples of such additives include antioxidants, ultraviolet inhibitors, antistatic agents, flame retardants, metal deactivators, pigments, and dyes. Specifically, the addition amount of the additive is preferably 3 parts by weight or less and more preferably 1 part by weight or less with respect to 100 parts by weight of the base resin.

  In the present invention, grooves are formed on both surfaces of the resin sheet, and in order for the lattice pattern to appear, it is necessary that the pattern formed on the back surface is seen through the surface. It is required to be a transparent resin. Further, even when the groove is formed only on one surface, it is required to use a transparent resin from the viewpoint of daylighting. However, the various additives can be added as long as the transparency is not impaired.

  By preparing a transparent resin sheet and press molding the resin sheet using a mold, the resin sheet of the present invention is formed by forming a plurality of grooves extending in one direction on one surface of the resin sheet. Further, if necessary, a plurality of grooves formed on one surface and a plurality of grooves extending at an angle of 0 to 90 ° with respect to the extending direction of the groove can be applied to the other surface. Can be shaped.

5A and 5B are drawings showing an example of a mold. The molds shown in FIGS. 5A and 5B are formed with recesses capable of forming a large number of bowl-shaped projections extending in one direction, and the surface of the recesses has a specific fineness. Fine irregularities capable of forming irregularities are formed. Examples of the method for forming fine irregularities on the mold include etching and blasting.
5A is a perspective view showing an example of a mold, and FIG. 5B is a sectional view for explaining the shape of a recess formed in the mold. What is necessary is just to form the width | variety and depth of a recessed part in the same dimension as the width | variety and height of the convex part of the target resin sheet.

  When a resin sheet is manufactured by press molding, it is preferable to provide an air vent in the mold. The diameter of the air vent hole is preferably 0.05 to 0.3 mm, and the distance between the air vent holes is preferably 5 to 30 mm. Further, it is particularly preferable that the air vent hole is in a portion corresponding to the groove portion of the resin sheet, since the trace of the air vent hole becomes inconspicuous and a resin sheet having an excellent appearance can be obtained.

  The resin sheet of the present invention is formed by extruding a melted thermoplastic resin into a sheet shape, taking up the extruded sheet-like material, and having a longitudinal groove roll having concave grooves continuous in the circumferential direction of the roll, and in the width direction of the roll. A forming roll comprising a transverse groove roll having continuous concave grooves, and by pressing the extruded sheet-like material, the surface shape of the forming roll is transferred to both surfaces of the sheet-like material to form the groove portion. It can also be obtained by a method. The fine irregularities can be shaped by forming fine irregularities capable of forming fine irregularities in the grooves of the longitudinal groove roll and / or the transverse groove roll. In order to form a ridge-like convex part and fine irregularities only on one side, the surface of either the longitudinal groove roll or the transverse groove roll may be smoothed.

The resin sheet of the present invention is suitably used for antique interior doors and furniture. Specific examples include interior / exterior lighting windows, partition materials, partition materials, closet doors and cupboard doors.
In addition, it can be used to confirm the presence of people and objects inside the room, but it cannot be specified until it is used for partition materials that require privacy protection, such as the doors of private rooms in hospital rooms and nursing homes, bathroom doors and lighting windows. There is expected. In addition, it may be used for lighting covers and commercial displays that make use of anti-glare properties.

Example 1
It is a pair of upper and lower molds, and on both inner wall surfaces, a concave part capable of forming a groove part and a bowl-like convex part, and a concave pattern having a width of 15 mm and a depth of 500 μm capable of forming a groove part between the convex parts are repeated. A press molding machine “FKS-0631-10” was used, in which the formed molds were used and each of the pair of molds was attached so that the extending direction of the groove portions intersected at 90 °.
From polystyrene resin (density 1.05 g / cm ³ ) containing organic beads with an average particle diameter of 12 μm made of MS resin (methyl methacrylate: styrene = 50: 50) and having fine irregularities formed on both surfaces Using a transparent polystyrene plate having a thickness of 4 mm, the plate is heated to a surface temperature of 165 ° C., and press-molded for 120 seconds, so that both surfaces extend in one direction at intervals of 15 mm and have a ridge-like convex shape with a height of 500 μm. A plurality of valley portions between the convex portions and adjacent convex portions were formed as groove portions, and a resin sheet in which fine irregularities due to organic beads were formed on the surface of the convex portions was obtained. The compounding amount of the organic beads was 1.2 parts by weight with respect to 100 parts by weight of the base resin of the resin sheet.

Example 2
A concave pattern with a width of 15 mm and a depth of 500 μm capable of forming a groove between the adjacent convex portions on the inner wall surfaces of the pair of molds is repeatedly formed, and the surface of the pattern is further blasted Example 1 except that a 4 mm-thick transparent plate made of methyl methacrylate-styrene copolymer resin (density 1.13 g / cm ³ ) was heated to a surface temperature of 175 ° C. with a heater, using a mold provided with A resin sheet was obtained in the same manner as above.

Example 3
A resin sheet was obtained in the same manner as in Example 2 except that a mold having a texture pattern formed by etching was used instead of blasting.

Example 4
In the pair of molds, a concave pattern having a width of 15 mm and a depth of 500 μm capable of forming a groove portion between adjacent convex portions on the inner wall surface of one mold is repeatedly formed. Except for the use of one mold in which the surface of the pattern is embossed by etching and the other mold in which the inner wall surface of the other mold is smooth and no grooves or fine irregularities are formed. A resin sheet was obtained in the same manner as in Example 3. In addition, the arithmetic average roughness (Ra) and the pencil hardness in Example 4 were measured by selecting a surface having a groove portion, a ridge-like convex portion, and a texture pattern on the surface.

Comparative Example 1
A resin sheet was obtained in the same manner as in Example 2 except that a mold whose surface was not blasted was used.

Comparative Example 2
A resin sheet was obtained in the same manner as in Example 2, except that a mold in which the bowl-shaped convex part and the concave part for forming the groove part were not formed was used.

  For the resin sheets obtained in Examples 1 to 3 and Comparative Example 1, optical characteristics (total light transmittance, diffuse light transmittance, parallel light transmittance), impact resistance (falling ball test), scratch resistance (pencil hardness) Table 1 shows the measurement results. In addition, as a reference example, one surface has a ridge-like convex portion that is repeated at equal intervals in the width direction, and the other surface has a ridge shape that extends in a direction orthogonal to the direction in which the handle on the one surface extends. The physical properties of a checker glass in which a pattern having a plurality of convex portions was repeatedly formed at equal intervals in the width direction were shown.

  The height of the bowl-shaped convex part 4 was determined by the following method. A 100 mm × 100 mm test piece was randomly cut out from the resin sheet, and a cross-section of the resin sheet was photographed with a microscope to obtain an enlarged photograph. Next, about the obtained enlarged photograph, the deepest point of the groove part of the both ends of the arbitrary ridge-shaped convex part 3 of a sheet | seat cross section using "surface roughness measuring machine surf coder SE1700α" by Kosaka Laboratory Ltd. Connect each other with a straight line A, and define a point that is a straight line parallel to the straight line A and point-contacts with the ridge-shaped peak as the ridge-shaped vertex, and downward from the ridge-shaped vertex in the thickness direction of the resin sheet A straight line B perpendicular to the straight line A was drawn. Next, the length from the apex of the bowl-shaped peak portion on the straight line B to the intersection with the straight line A was measured, and the height of the convex portion 4 was determined in consideration of the magnification. The said operation was performed about 4 points | pieces at equal intervals, and the arithmetic average value of 4 points | pieces was made into the height of the bowl-shaped convex part 4. FIG.

  Arithmetic average roughness (Ra) on the surface of the resin sheet, average length (Rsm) of the roughness curve element, in accordance with JIS B0601 (2013), cut-off λc = 0.8, measurement length = 8mm, The surface roughness was measured using a surface roughness measuring machine (“Surface Roughness Measuring Machine Surfcoder SE1700α” manufactured by Kosaka Laboratory Ltd.). Specifically, a 300 mm × 300 mm test piece was randomly cut out from the resin sheet, three equally spaced locations on one surface of the test piece were selected at random, and the above operation was performed on three test pieces. The arithmetic average value of the obtained values was defined as the arithmetic average roughness (Ra) on the surface of the resin sheet and the average length (Rsm) of the roughness curve elements.

  The total light transmittance, parallel line transmittance, and diffusive transmittance were cut out of a test piece having a size of 20 mm × 20 mm (thickness is the thickness of the resin sheet) from the resin sheet so as to include two grooves in the vertical and horizontal directions. Draw six straight lines to divide each into seven equal parts, and turbidimeter (Haze Meter NDH7000SP manufactured by Nippon Denshoku Industries Co., Ltd.) according to JIS K7361 (1997) for 49 points (7 × 7) divided by the straight lines. ) Was used to measure the total light transmittance, parallel line transmittance, and diffusible transmittance of the test piece. Values obtained by arithmetically averaging the values of the obtained 49 locations were adopted as total light transmittance, parallel light transmittance, and diffused light transmittance, and are shown in Table 1.

Falling ball test In the falling ball test, a test piece of 250 mm × 250 mm was randomly cut from a resin sheet, and the outer periphery of the test piece was sandwiched between iron molds (inner dimensions of iron molds 220 mm × 220 mm). Fix the steel ball to a height of 30 mm, drop an iron ball with a weight of 1040 g and a diameter of 63.5 mm starting from a height of 10 mm and increasing the height in units of 10 mm to determine the height at which the crack occurred. Recorded, and the average value of 5 times was taken as the falling ball average breaking height (mm).

Scratch hardness test (pencil method)
For the scratch hardness test, No. manufactured by Yasuda Seiki Seisakusho Co., Ltd. Using 553-S, a pencil hardness test was performed by a method (angle 45 °, load 750 g, speed 1 mm / s, temperature 23 ° C.) in accordance with JIS K5600-5-4 (1999). Note that the hardness in the pencil method is defined as “2B <B <HB <F <H <2H <3H <4H” when the higher hardness is defined as large.

DESCRIPTION OF SYMBOLS 1 Resin sheet 2a One surface 2b The other surface 3a Groove part formed in one surface 3b Groove part formed in the other surface 3 Groove part generic name 4a Convex part formed in one surface 4b Formed in the other surface Projection 4 General name of projection 5a Fine irregularities formed on one surface 5b Fine irregularities formed on the other surface 5 Generic name of fine irregularities H Height of projection 4 H (1) One surface The height H (2) of the convex portion 4a formed on the other surface W The height of the convex portion 4b formed on the other surface W The width between the adjacent groove portions W (1) Between the groove portions 3a formed on one surface Width W (2) The width between the grooves 3b formed on the other surface

Claims (9)

In a resin sheet using a transparent thermoplastic resin as a base resin, a plurality of grooves extending in one direction are formed on at least one surface of the resin sheet, and the surface on which the grooves are formed has an arithmetic average height ( A resin sheet characterized in that Ra) is a roughened surface having fine irregularities of 5 to 60 μm.
On the other surface of the resin sheet, a plurality of groove portions extending in the direction of an angle of 0 ° to 90 ° with respect to the extending direction of the groove portion formed on the one surface are formed, and the 0 ° to 90 ° The other surface on which the groove extending at an angle of 5 is formed is a roughened surface having fine irregularities having an arithmetic average height (Ra) of 5 to 60 μm. Resin sheet.
A number of groove portions extending in a direction of an angle of 80 ° to 90 ° with respect to a direction in which the groove portion formed on the one surface extends are formed on the other surface of the resin sheet. Item 3. The resin sheet according to Item 2.
The resin sheet according to claim 1, wherein the resin sheet has a total light transmittance of 80% or more and a parallel light transmittance of 60% or less.
The pencil hardness on the roughened surface is H or more in a pencil hardness test in accordance with JIS K5600-5-4 (1999), according to any one of claims 1-4. Resin sheet.
The resin sheet according to claim 1, wherein the arithmetic average height (Ra) is 30 to 60 μm.
The groove depth of the groove part of the said resin sheet is 300-1500 micrometers, The resin sheet in any one of Claims 1-6 characterized by the above-mentioned.
The resin sheet according to claim 1, wherein the basis weight of the resin sheet is 2000 to 9000 g / m ² .
The resin sheet according to claim 1, wherein the transparent thermoplastic resin is any one of a styrene resin, an acrylic resin, and a polycarbonate resin.