Method of manufacturing a transparent sheet and transparent sheet

Abstract

The present invention relates to a method for manufacturing a transparent sheet, and more specifically, to a method for manufacturing a transparent sheet and a transparent sheet manufactured by said method, wherein a first transparent resin comprising a graft copolymer of a conjugated diene polymer and a second transparent resin comprising a graft copolymer of an acrylic polymer are used as film laminations.

Description

Technical Field

[0001] [Cross-references to related applications]

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2021-0107579, filed with the Korean Intellectual Property Office on August 13, 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0003] This invention relates to a method for manufacturing transparent sheets and transparent sheets. Background Technology

[0004] Transparent sheets used outdoors, such as canopies and soundproof walls, require high weather resistance to maintain transparency and prevent discoloration. Therefore, transparent polycarbonate sheets or transparent sheets manufactured by co-extruding resins with excellent weather resistance or excellent UV stability onto transparent resins are used as outdoor transparent sheets.

[0005] However, when co-extruding two or more resins, the limitations are that not only is the manufacturing process complex, but the loss of raw resin also becomes very large, thus making it economically unfeasible. Further limitations include the susceptibility of polycarbonate to scratches and abrasions, its weak chemical resistance making it sensitive to organic solvents, and its yellowing upon prolonged exposure to sunlight.

[0006] [Existing Technical Documents]

[0007] [Patent Literature]

[0008] (Patent Document 1) KR 10-2011-0011670A Summary of the Invention

[0009] Technical issues

[0010] One object of the present invention, which addresses the aforementioned limitations, is to ensure weather resistance and chemical resistance without degrading the transparency of the transparent sheet, while also addressing the complexity of the manufacturing process during co-extrusion and minimizing the loss of raw material resin.

[0011] That is, one aspect of the present invention provides a method for manufacturing a transparent sheet that has guaranteed weather resistance and chemical resistance without deterioration in its transparency, while overcoming the limitations of co-extrusion by lamination rather than co-extrusion.

[0012] Furthermore, another aspect of the present invention provides a transparent sheet manufactured by the method for manufacturing transparent sheets, which has guaranteed weather resistance and chemical resistance without deterioration in its transparency.

[0013] Technical solution

[0014] According to one aspect of the present invention, a method for manufacturing a transparent sheet and a transparent sheet thereby manufactured are provided.

[0015] (1) According to one aspect of the present invention, a method for manufacturing a transparent sheet is provided, the method comprising the steps of: extruding a first transparent resin from a T-die (S10); conveying the T-die first transparent resin film extruded from the T-die to a compression roller (S20); feeding a second transparent resin film into the compression roller together with the first transparent resin film while the first transparent resin film is discharged from the T-die and fed into the compression roller, and simultaneously bonding the second transparent resin film to at least one surface of the first transparent resin film (S30); and laminating the first transparent resin film and the second transparent resin film using the compression roller (S40), wherein the first transparent resin is a graft copolymer comprising a conjugated diene polymer and the second transparent resin is a graft copolymer comprising an acrylic polymer.

[0016] (2) In the above (1) of the present invention, a method for manufacturing transparent sheet is provided, wherein the temperature of the extruder is 190°C to 210°C during the extrusion process in step S10.

[0017] (3) In the above (1) or (2) of the present invention, a method for manufacturing a transparent sheet is provided, wherein, in the above step S30, the first transparent resin film and the second transparent resin film of the T-shaped mold are fed into the compression roller and then combined.

[0018] (4) In any of (1) to (3) of the present invention, a method for manufacturing a transparent sheet is provided, wherein, in step S30, the second transparent resin film is unwound from the winding roller on which the second transparent resin film is wound and conveyed to the compression roller.

[0019] (5) In any one of (1) to (4) of the present invention, a method for manufacturing a transparent sheet is provided, wherein, in step S30, when the first transparent resin film of the T-shaped mold is discharged from the T-shaped mold and fed into the compression roller, the second transparent resin film is fed into the compression roller together and bonded to both surfaces of the first transparent resin film of the T-shaped mold.

[0020] (6) In any of (1) to (5) of the present invention, a method for manufacturing a transparent sheet is provided, wherein the temperature of the compression roller is 40°C to 70°C during the lamination process in step S40.

[0021] (7) In any of (1) to (6) of the present invention, a method for manufacturing a transparent sheet is provided, wherein the first transparent resin is a graft copolymer comprising a conjugated diene polymer, an aromatic vinyl monomer unit and a vinyl cyanide monomer unit.

[0022] (8) In any of (1) to (7) of the present invention, a method for manufacturing a transparent sheet is provided, wherein the second transparent resin is a graft copolymer comprising an acrylic polymer, an aromatic vinyl monomer unit and a vinyl cyanide monomer unit.

[0023] (9) In any of (1) to (8) of the present invention, a method for manufacturing a transparent sheet is provided, wherein, for a sample with a thickness of 3.2 mm, the second transparent resin has a haze of less than 10%.

[0024] (10) In any of (1) to (9) of the present invention, a method for manufacturing a transparent sheet is provided, wherein, for a sample with a thickness of 3.2 mm, the second transparent resin has a transmittance (Tt) of 70% or more.

[0025] (11) In any of (1) to (10) of the present invention, a method for manufacturing a transparent sheet is provided, wherein the second transparent resin has a haze of 8% or less for a sheet with a thickness of 0.3 mm or a sheet with a thickness of 0.05 mm.

[0026] (12) In any of (1) to (11) of the present invention, a method for manufacturing a transparent sheet is provided, wherein the second transparent resin has a transmittance (Tt) of 80% or more for a sheet with a thickness of 0.3 mm or a sheet with a thickness of 0.05 mm.

[0027] (13) In any of (1) to (12) above, a method for manufacturing a transparent sheet is provided, wherein the first transparent resin and the second transparent resin have the same refractive index.

[0028] (14) According to one aspect of the present invention, a transparent sheet is provided, comprising: a T-shaped first transparent resin film layer; and a second transparent resin film layer laminated on at least one surface of the T-shaped first transparent resin film layer, wherein the first transparent resin is a graft copolymer comprising a conjugated diene polymer, the second transparent resin is a graft copolymer comprising an acrylic polymer, and the T-shaped first transparent resin film layer and the second transparent resin film layer each have a uniform thickness in the transverse (TD) direction of the transparent sheet.

[0029] (15) In the above (14) of the present invention, a transparent sheet is provided, wherein, relative to the total thickness of the transparent sheet, the thickness of the first transparent resin film layer of the T-shaped mold is 85% to 99% and the thickness of the second transparent resin film layer is 1% to 15%.

[0030] Beneficial effects

[0031] When transparent sheets are manufactured using the method for manufacturing transparent sheets according to the present invention, not only can the complexity of the manufacturing process that occurs during co-extrusion be solved, but the loss of raw material resin can also be minimized, and further, weather resistance and chemical resistance can be ensured without deterioration of the transparency of the transparent sheet. Attached Figure Description

[0032] Figure 1 This is a process flow diagram illustrating a method for manufacturing a transparent sheet according to an embodiment of the present invention.

[0033] Figure 2 This is a process flow diagram illustrating a method for manufacturing a transparent sheet according to another embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram showing the cross-section of a transparent sheet manufactured according to a co-extrusion method and the cross-section of a transparent sheet according to an embodiment of the present invention.

[0035] Figure 4 These are photographs taken of the transparent sheets manufactured in Embodiment 1 and Comparative Example 1 of the present invention.

[0036] Figure 5 These are photographs taken of the transparent sheets manufactured in Embodiment 2 and Comparative Example 2 of the present invention.

[0037] Figure 6 These are photographs taken of the chemical resistance test results of the transparent sheets manufactured in Example 1 and Comparative Example 1 of the present invention.

[0038] Figure 7 and Figure 8 These are photographs taken of the chemical resistance test results of the transparent sheets manufactured in Example 2, Comparative Example 2, and Reference Examples 1 and 2 of the present invention.

[0039] Figure 9 These are photographs taken of the weather resistance test results of the transparent sheets manufactured in Example 1 and Comparative Example 1 of the present invention.

[0040] Figure 10 These are photographs taken of the weather resistance test results of the transparent sheets manufactured in Example 2, Comparative Example 2 and Reference Example 1 of the present invention.

[0041] Figure 11 and Figure 12 Each of the photographs is a result of a heat and cold resistance test on the transparent sheet manufactured in Example 1 and Comparative Example 1 of the present invention.

[0042] Figure 13 These are photographs taken of the results of heat and cold resistance tests on the transparent sheets manufactured in Example 2 and Comparative Example 2 of the present invention. Detailed Implementation

[0043] The invention will be described in more detail below to aid in understanding it.

[0044] It should be understood that the words or terms used in the specification and claims of this invention should not be construed as limited to or having the meanings defined in common dictionaries. It should also be understood that, based on the inventor's ability to appropriately define the meanings of words or terms to best illustrate the principles of the invention, the words or terms should be understood to have meanings consistent with their meanings in the context of the relevant art and in the technical concept of the invention.

[0045] This invention provides a method for manufacturing transparent sheets.

[0046] According to one embodiment of the present invention, the method for manufacturing a transparent sheet may include the following steps: extruding a first transparent resin from a T-die (S10); conveying the T-die first transparent resin film extruded from the T-die to a compression roller (S20); feeding a second transparent resin film into the compression roller together with the first transparent resin film while the first transparent resin film is discharged from the T-die and fed into the compression roller, and simultaneously bonding the second transparent resin film to at least one surface of the first transparent resin film (S30); and laminating the first transparent resin film and the second transparent resin film using the compression roller (S40), wherein the first transparent resin may be a graft copolymer comprising a conjugated diene polymer, and the second transparent resin may be a graft copolymer comprising an acrylic polymer.

[0047] As used herein, the terms “film” and “sheet” are each resin-molded articles having a predetermined thickness and exhibiting a planar shape, and can be used in the same manner. However, specifically, when the thickness is relatively thin or before lamination, the resin-molded article may be referred to as a film, while when the thickness is relatively thick or after lamination, the resin-molded article may be referred to as a sheet.

[0048] According to one embodiment of the present invention, the method of manufacturing the transparent sheet may be a method of manufacturing the transparent sheet by laminating the first transparent resin and the second transparent resin in the form of a film without co-extruding the first transparent resin and the second transparent resin.

[0049] According to one embodiment of the present invention, step S10 may be a step of performing T-die extrusion to produce a film-like first transparent resin, so as to use the first transparent resin to manufacture a transparent sheet. As a specific example, see... Figure 1 and Figure 2 The first transparent resin supplied to the hopper of the extruder 10 can be discharged from the T-die 11 provided in the extruder 10 to produce a T-die first transparent resin film TR1 in the shape of a T-die film. In this case, the above step S10 can be performed continuously, so the T-die first transparent resin film TR1 can be continuously discharged from the T-die 11 provided in the extruder 10.

[0050] According to one embodiment of the present invention, during the extrusion process in step S10 above, the temperature of the extruder can be from 190°C to 210°C, and within this range, the surface temperature of the first transparent resin film TR1 discharged from the T-die 11 can be maintained to be sufficient for lamination with the second transparent resin films TR21 and TR22, which will be described later, thereby inducing lamination of the first transparent resin film TR1 with the second transparent resin films TR21 and TR22 without heating the compression rollers.

[0051] According to one embodiment of the invention, since the method for manufacturing transparent sheets does not require co-extrusion, both single-layer and multi-layer extruders can be used as extruder 10.

[0052] According to one embodiment of the present invention, step S20 is the step of conveying the T-die first transparent resin film TR1 extruded from the T-die 11 to the compression rolls 21 and 22 according to step S10, and can be performed such that the T-die first transparent resin film TR1 can be directly fed into the compression rolls 21 and 22 without passing through a separate calendering roll for smoothing before being fed into the compression rolls 21 and 22. That is, step S20 is characterized in that the T-die first transparent resin film TR1 discharged from the T-die 11 provided in the extruder 10 is directly fed into the compression rolls 21 and 22. As described above, when the T-die first transparent resin film TR1 discharged from the T-die 11 provided in the extruder 10 is directly fed into the compression rolls 21 and 22, a separate calendering roll is not required, thereby simplifying the process and minimizing the surface temperature variation of the T-die first transparent resin film TR1, which can induce lamination with the second transparent resin films TR21 and TR22.

[0053] According to one embodiment of the present invention, step S20 can be performed continuously after step S10. Therefore, starting from step S10, the first transparent resin film TR1 of the T-die can be continuously discharged from the T-die 11 provided in the extruder 10, and can be continuously conveyed to the compression rollers 21 and 22.

[0054] According to one embodiment of this disclosure, step S30 may be a step of bonding the first transparent resin film TR1 and the second transparent resin films TR21 and TR22 of the T-shaped mold to the compression rollers 21 and 22 before feeding the first transparent resin film TR1 and the second transparent resin films TR21 and TR22 of the T-shaped mold into the compression rollers 21 and 22, so that the first transparent resin film TR1 and the second transparent resin films TR21 and TR22 of the T-shaped mold can be laminated on the compression rollers 21 and 22. That is, when the first transparent resin film TR1 of the T-shaped mold is discharged from the T-shaped mold 11 and fed into the compression rollers 21 and 22 through the above steps S10 and S20, step S30 may be performed simultaneously with bonding the second transparent resin films TR21 and TR22 to at least one surface of the first transparent resin film TR1 of the T-shaped mold and feeding them together into the compression rollers 21 and 22. In this case, the bonding refers to inducing one surface of the second transparent resin films TR21 and TR22 to contact at least one surface of the first transparent resin film TR1 of the T-die, and lamination is not achieved through bonding itself. The first transparent resin film TR1 and the second transparent resin films TR21 and TR22 of the T-die can have a shape in which the films are simply stacked by bonding. As a specific example, the first transparent resin film TR1 and the second transparent resin films TR21 and TR22 of the T-die can be bonded simultaneously with feeding into the compression rollers 21 and 22.

[0055] According to one embodiment of the present invention, step S30 can be performed continuously after steps S10 and S20. Therefore, starting from step S10, the first transparent resin film TR1 of the T-die can be continuously discharged from the T-die 11 provided in the extruder 10, and simultaneously, it can be continuously conveyed and fed into compression rollers 21 and 22. The second transparent resin films TR21 and TR22 can be continuously bonded to at least one surface of the first transparent resin film TR1 of the T-die, and can be fed together into compression rollers 21 and 22. Therefore, in step S30, the second transparent resin films TR21 and TR22 can be conveyed to compression rollers 21 and 22 simultaneously with unwinding from the winding rollers 41 and 42 that wind the second transparent resin films TR21 and TR22.

[0056] According to one embodiment of the present invention, in step S30 above, when the first transparent resin film TR1 of the T-die is discharged from the T-die 11 and fed into the compression rollers 21 and 22, the second transparent resin films TR21 and TR22 can be simultaneously bonded to both surfaces of the first transparent resin film TR1 of the T-die when they are fed together into the compression rollers 21 and 22. In this case, the second transparent resin films TR21 and TR22 can be laminated onto both surfaces of the first transparent resin film TR1 of the T-die.

[0057] According to one embodiment of the present invention, step S40 is a step of laminating the first transparent resin film TR1 and the second transparent resin films TR21 and TR22 fed from step S30 into compression rollers 21 and 22 in a mutually compatible state, and the first transparent resin film TR1 and the second transparent resin films TR21 and TR22 can be laminated simultaneously through compression rollers 21 and 22 to form a transparent sheet TS.

[0058] According to one embodiment of the present disclosure, the transparent sheet TS formed by compression rollers 21 and 22 may include: a T-shaped first transparent resin film layer; and a second transparent resin film layer stacked on at least one surface of the T-shaped first transparent resin film layer.

[0059] According to one embodiment of the present invention, during the lamination process in step S40 above, the temperature of compression rollers 21 and 22 can be 40°C to 70°C or 40°C to 60°C.

[0060] According to one embodiment of the invention, compression rollers 21 and 22 may be a pair of calendering rollers. That is, the T-die first transparent resin film TR1 and the second transparent resin films TR21 and TR22 bonded to at least one surface thereon, fed to compression rollers 21 and 22, can be fed between the pair of compression rollers 21 and 22, which are a pair of calendering rollers. The pair of compression rollers 21 and 22 rotate about a rotation axis, wherein the T-die first transparent resin film TR1 and the second transparent resin films TR21 and TR22 bonded to at least one surface thereon, fed between the pair of compression rollers 21 and 22, can be laminated due to the compression caused by the pair of compression rollers 21 and 22, thus allowing the production of a transparent sheet TS simultaneously with the passing through the pair of compression rollers 21 and 22. Additionally, the transparent sheet TS, which has already passed through a pair of compression rollers 21 and 22, can be fed and passed between any one of the compression rollers 21 and the compression roller 23 connected thereto. If necessary, it can be further passed through additional calendering rollers. The positions of the multiple compression rollers 21, 22, and 23 can be adjusted to positions sufficient for laminating the first transparent resin film TR1 of the T-die and the second transparent resin films TR21 and TR22 bonded to at least one surface thereto. Furthermore, each compression roller may include a stretching roller, in which case the smoothness of the transparent sheet TS can be improved. The diameter and length of the compression rollers 21, 22, and 23 can be adjusted according to the length of the T-die 11 disposed in the extruder 10, the width and thickness of the transparent sheet TS to be manufactured, etc., and they can have the same diameter and length as each other.

[0061] According to one embodiment of the present invention, step S40 can be performed continuously after steps S10 to S30, so that the transparent sheet TS that has passed through compression rollers 21, 22 and 23 can be continuously obtained by winding it onto a separate winding roller (not shown).

[0062] As described above, according to one embodiment of the present invention, the method for manufacturing the transparent sheet may not be based on a simple roll-to-roll process but rather on a similar roll-to-roll process in which the first transparent resin film TR1 of the T-die is discharged and conveyed to be directly fed into the compression rollers 21 and 22 according to the above steps S10 and S20, wherein the second transparent resin films TR21 and TR22 are fed together into the compression rollers 21 and 22 according to the above step S30, and in the above step S40, the first transparent resin film TR1 of the T-die and the second transparent resin films TR21 and TR22 bonded to at least one surface thereon are laminated by passing them through the compression rollers 21 and 22 to manufacture the transparent sheet TS, and the manufactured transparent sheet TS is wound using a winding roller.

[0063] According to one embodiment of the invention, it is important to carry out the method of manufacturing the transparent sheet according to steps S10 to S40 above, but it is equally important to select the first transparent resin constituting the first transparent resin film TR1 of the T-die and the second transparent resin constituting the second transparent resin film, so that, as in steps S10 to S40 above, when the first transparent resin film TR1 of the T-die and the second transparent resin films TR21 and TR22 bonded to at least one surface thereto are laminated, the transparent sheet TS is manufactured without co-extrusion and without separately heating the compression rollers, while ensuring weather resistance and chemical resistance without deterioration of the transparency of the transparent sheet.

[0064] As mentioned in the background section of this invention, outdoor transparent sheets such as canopies and soundproof walls require high weather resistance to maintain transparency and prevent discoloration. Polycarbonate resin, polymethyl methacrylate resin, ethylene glycol-modified polyethylene terephthalate resin, or transparent ABS resin can be considered as transparent resins for such outdoor transparent sheets. However, polymethyl methacrylate resin, which has excellent weather resistance, is limited by its weak impact resistance and chemical resistance; polycarbonate resin is limited by its weak abrasion resistance and weather resistance; ethylene glycol-modified polyethylene terephthalate resin is limited by its weak weather resistance and heat resistance; and transparent ABS resin has excellent impact resistance, transparency, heat resistance, and abrasion resistance, but is limited by its very weak weather resistance and chemical resistance. Therefore, the present invention is characterized by the introduction of a second transparent resin to ensure the weather resistance and chemical resistance of the transparent resin.

[0065] However, refer to Figure 3 When a second transparent resin is simply introduced through co-extrusion with a first transparent resin, the transparent sheet is inevitably manufactured in a form in which the second transparent resin surrounds the first transparent resin. In this case, when observing the cross-section of the transparent sheet, the first and second transparent resin film layers in the T-die inevitably have uneven thicknesses in the TD direction of the transparent sheet. This uneven thickness ultimately causes an increase in the haze of the transparent sheet and also causes temperature-based warping. Furthermore, since the thickness of the second transparent resin film layer inevitably increases, the uneven thickness causes a deterioration in the impact resistance of the transparent sheet itself.

[0066] On the other hand, refer to Figure 3When a transparent sheet is manufactured according to the method of manufacturing a transparent sheet according to the present invention, second transparent resin films TR21 and TR22 are laminated on at least one surface of a T-die first transparent resin film TR1. Therefore, the transparent sheet is manufactured in a form in which the second transparent resin film layers are stacked on top of the T-die first transparent resin film layers. In this case, when the cross-section of the transparent sheet is observed, the T-die first transparent resin film layer and the second transparent resin film layer each have a uniform thickness in the TD direction of the transparent sheet. Therefore, in the case of a transparent sheet manufactured according to the method of manufacturing a transparent sheet according to the present invention, when performing a trimming process to cut unnecessary portions from the manufactured transparent sheet, only a portion of the T-die first transparent resin film layer that is not laminated with the second transparent resin film layer can be set as a trimming line. In this case, the trimmed portion of the T-die first transparent resin film layer can be entirely recycled as the first transparent resin. Furthermore, the resins of the first and second transparent resin films in the T-molding can be induced to have the same refractive index. Preferably, as described below, the refractive indices are the same, and the monomer compositions of the individual resins are similar, so that even if the transparent sheet containing both the first and second transparent resin films in the T-molding is recycled, the transparency and haze are not affected. Moreover, since the thickness of the first and second transparent resin films in the T-molding is uniform, the haze of the transparent sheet is not affected. Due to less warping deformation caused by temperature, and the fact that the second transparent resin film can be formed thinly, the first transparent resin film in the T-molding exhibits excellent transparency and color rendering, while also ensuring the impact resistance of the transparent sheet itself.

[0067] In this case, according to one embodiment of the invention, the second transparent resin used to achieve the advantages of the second transparent resin film layer can be a graft copolymer containing an acrylic polymer. Meanwhile, in the method of manufacturing a transparent sheet according to the invention, when introducing the graft copolymer containing an acrylic polymer as the second transparent resin, the transparent resin as the first transparent resin can include polycarbonate resin, polymethyl methacrylate resin, ethylene glycol-modified polyethylene terephthalate resin, and transparent ABS resin. However, polycarbonate resin and ethylene glycol-modified polyethylene terephthalate resin are unsuitable for bonding and laminating the graft copolymer containing an acrylic polymer as the second transparent resin due to the high extrusion process temperature of 270°C to 300°C when manufacturing the T-die using extruder 10. Furthermore, crystalline polymers are unsuitable because peeling may occur after lamination with the second transparent resin film. Taking these points into consideration, and considering refractive index adjustment, recycling possibility, and compatibility with the second transparent resin, the first transparent resin according to the invention is preferably a graft copolymer containing a conjugated diene polymer, such as transparent ABS resin.

[0068] That is, taking into account all the above points, the first transparent resin used in the method of manufacturing transparent sheets according to the present invention can be a graft copolymer containing conjugated diene polymers, the second transparent resin can be a graft copolymer containing acrylic polymers, and the method of manufacturing transparent sheets according to the present invention can only be applied when the first transparent resin and the second transparent resin satisfy certain conditions.

[0069] According to one embodiment of the present invention, the first transparent resin may be a graft copolymer comprising a conjugated diene polymer, aromatic vinyl monomer units, and vinyl cyanide monomer units. As a specific example, the first transparent resin may be a graft copolymer formed by grafting aromatic vinyl monomer units and vinyl cyanide monomer units onto a conjugated diene polymer.

[0070] According to one embodiment of the present invention, the conjugated diene polymer may comprise conjugated diene monomer units, and the conjugated diene monomer used to form the conjugated diene monomer units may be at least one selected from 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, isoprene, 3-butyl-1,3-octadiene, isoprene, and 2-phenyl-1,3-butadiene, more specifically, 1,3-butadiene. Additionally, if desired, the conjugated diene polymer may also comprise aromatic vinyl monomer units.

[0071] According to one embodiment of the present invention, the aromatic vinyl monomer of the aromatic vinyl monomer unit used to form the first transparent resin may be at least one selected from styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene and 1-vinyl-5-hexylnaphthalene, specifically, it may be styrene.

[0072] According to one embodiment of the present invention, the vinyl cyanide monomer of the vinyl cyanide monomer unit used to form the first transparent resin may be at least one selected from acrylonitrile, methacrylonitrile, ethyl acrylonitrile, phenyl acrylonitrile and α-chloroacrylonitrile, specifically, it may be acrylonitrile.

[0073] According to one embodiment of the present invention, the first transparent resin may further comprise an alkyl methacrylate monomer unit to provide transparency, and the alkyl methacrylate monomer used to form the alkyl methacrylate monomer unit may be an alkyl methacrylate monomer having 1 to 12 carbon atoms, specifically, it may be at least one selected from methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate and n-butyl acrylate.

[0074] According to one embodiment of the invention, the amounts of the conjugated diene polymer, aromatic vinyl monomer units, vinyl cyanide monomer units, and (meth)acrylate alkyl ester monomer units of the first transparent resin can be appropriately adjusted to ensure the transparency of the first transparent resin manufactured from the graft copolymer.

[0075] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D638, the tensile strength of the first transparent resin can be 100 kgf / cm². 2 Above, 200kgffcm 2 Above, 300 kgf / cm 2 Above or 350kgffcm 2 The above, and the tensile strength can also be 800 kgf / cm. 2 Below, 700kgffcm 2 Below, 600 kgf / cm 2 Below, 500 kgf / cm 2 Below or 450kgffcm 2 the following.

[0076] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D790, the flexural strength of the first transparent resin can be 200 kgf / cm². 2 Above, 300kgffcm 2 Above, 400 kgf / cm 2 Above, 500kgffcm 2 Above or 600kgffcm 2 The above, and the bending strength can also be 1,000 kgf / cm. 2 Below, 900 kgf / cm 2 Below, 800 kgf / cm 2 Below, 700kgffcm 2 Below or 650 kgf / cm 2 the following.

[0077] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D790, the flexural modulus of the first transparent resin can be 10,000 kgf / cm². 2 Above, 12,000kgffcm 2 Above, 15,000 kgf / cm 2 Above, 16,000kgffcm 2 Above or 17,000 kgffcm 2The above, and the flexural modulus can also be 50,000 kgf / cm. 2 Below, 40,000 kgf / cm 2 Below, 30,000kgffcm 2 Below, 25,000 kgf / cm 2 Below, or 20,000 kgffcm 2 the following.

[0078] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 4″ as measured according to ASTM D256, the notched cantilever beam impact strength of the first transparent resin at 23°C can be greater than 1 kgfcm / cm, greater than 2 kgfcm / cm, greater than 3 kgfcm / cm, greater than 4 kgfcm / cm, or greater than 5 kgfcm / cm, and the notched cantilever beam impact strength can also be less than 20 kgfcm / cm, less than 15 kgfcm / cm, less than 10 kgfcm / cm, less than 9 kgfcm / cm, less than 8 kgfcm / cm, or less than 7 kgfcm / cm.

[0079] According to one embodiment of the present invention, for a standard based on ASTM D648 (18.6 kgf / cm²) 2 For a sample with a thickness of 6.4 mm, the heat distortion temperature of the first transparent resin can be above 50℃, above 60℃, above 70℃ or above 75℃, and the heat distortion temperature can also be below 100℃, below 90℃ or below 85℃.

[0080] According to one embodiment of the present invention, the melt index of the first transparent resin, measured at 220°C and under a load of 10 kgf, can be greater than 1 g / 10 min or greater than 2 g / 10 min, and the melt index can also be less than 10 g / 10 min, less than 8 g / 10 min, less than 6 g / 10 min, or less than 4 g / 10 min, according to ASTM D1238.

[0081] According to one embodiment of the present invention, the second transparent resin may be a graft copolymer comprising an acrylic polymer, aromatic vinyl monomer units, and vinyl cyanide monomer units. As a specific example, the second transparent resin may be a graft copolymer formed by grafting aromatic vinyl monomer units and vinyl cyanide monomer units onto an acrylic polymer. In this respect, in the prior art, the transparency of the graft copolymer comprising an acrylic polymer, aromatic vinyl monomer units, and vinyl cyanide monomer units corresponding to the second transparent resin, i.e., ASA resin, has not been achieved. However, in the present invention, the object of the invention can be achieved by using a graft copolymer comprising a novel acrylic polymer with transparency as the second transparent resin, and the object of the invention cannot be achieved by using conventional opaque ASA resin because the transparency of the transparent sheet cannot be ensured as in the present invention.

[0082] According to one embodiment of the present invention, the acrylic polymer may comprise acrylic monomer units, wherein the acrylic monomer used to form the acrylic monomer units may be an alkyl (meth)acrylate monomer, specifically an alkyl (meth)acrylate monomer having 1 to 12 carbon atoms, and more specifically, may be at least one selected from methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, and n-butyl acrylate.

[0083] According to one embodiment of the present invention, the aromatic vinyl monomer of the aromatic vinyl monomer unit used to form the second transparent resin may be at least one selected from styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene and 1-vinyl-5-hexylnaphthalene, specifically, it may be styrene.

[0084] According to one embodiment of the present invention, the vinyl cyanide monomer of the vinyl cyanide monomer unit used to form the second transparent resin may be at least one selected from acrylonitrile, methacrylonitrile, ethyl acrylonitrile, phenyl acrylonitrile and α-chloroacrylonitrile, specifically, it may be acrylonitrile.

[0085] According to one embodiment of the present invention, the amounts of the acrylic polymer, aromatic vinyl monomer units, and vinyl cyanide monomer units of the second transparent resin can be appropriately adjusted to ensure the transparency of the second transparent resin prepared from the graft copolymer.

[0086] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D638, the tensile strength of the second transparent resin can be 100 kgf / cm².2 Above, 150 kgf / cm 2 Above or 250 kgf / cm 2 The above, and the tensile strength can also be 800 kgf / cm. 2 Below, 500kgffcm 2 Below or 350kgffcm 2 the following.

[0087] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D638, the elongation of the second transparent resin can be more than 50%, more than 55%, more than 60%, more than 65%, more than 70%, or more than 75%, and the elongation can be less than 100%, less than 95%, less than 90%, or less than 85%.

[0088] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D790, the flexural strength of the second transparent resin can be 100 kgf / cm². 2 Above, 300kgffcm 2 Above or 400 kgf / cm 2 The above, and the bending strength can also be 800 kgf / cm. 2 Below, 600 kgf / cm 2 Below or 500kgffcm 2 the following.

[0089] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 8″ as measured according to ASTM D790, the flexural modulus of the second transparent resin can be 5,000 kgf / cm². 2 Above, 8,000kgffcm 2 Above, 10,000kgffcm 2 Above or 11,000 kgffcm 2 The above, and the flexural modulus can also be 30,000 kgf / cm. 2 Below, 20,000 kgf / cm 2 Below or 15,000 kgffcm 2 the following.

[0090] According to one embodiment of the present invention, for a specimen with a thickness of 1 / 4″ as measured according to ASTM D256, the notched cantilever beam impact strength of the second transparent resin at 23°C can be 1 kgfcm / cm or more, 2 kgfcm / cm or more, 3 kgfcm / cm or more, 4 kgfcm / cm or more, 5 kgfcm / cm or more, or 6 kgfcm / cm or more, and the notched cantilever beam impact strength can also be 20 kgfcm / cm or less, 15 kgfcm / cm or less, 10 kgfcm / cm or less, 9 kgfcm / cm or less, or 8 kgfcm / cm or less.

[0091] According to one embodiment of the present invention, for a weight according to ASTM D648 (18.6 kgffcm) 2 For a sample with a thickness of 6.4 mm, the heat distortion temperature of the second transparent resin can be above 50℃, above 60℃, or above 65℃, and the heat distortion temperature can also be below 100℃, below 90℃, or below 80℃.

[0092] According to one embodiment of the present invention, the melt index of the second transparent resin, measured at 220°C and under a load of 10 kgf according to ASTM D1238, can be greater than 1 g / 10 min, greater than 2 g / 10 min, or greater than 3 g / 10 min, and the melt index can also be less than 10 g / 10 min, less than 8 g / 10 min, less than 6 g / 10 min, or less than 5 g / 10 min.

[0093] According to one embodiment of the present invention, for a sample with a thickness of 3.2 mm as measured according to ASTM D785, the Rockwell hardness of the second transparent resin can be 50 or more, 55 or more, 60 or more, 65 or more, 70 or more, or 75 or more, and the Rockwell hardness can be less than 100, less than 95, less than 90, or less than 85.

[0094] According to one embodiment of the present invention, for a sample with a thickness of 3.2 mm, the haze of the second transparent resin can be less than 10%, less than 9%, less than 8%, less than 7%, less than 6%, less than 5%, or less than 4%, and the haze can be more than 0.1%, more than 0.5%, or more than 1%.

[0095] According to one embodiment of the present invention, for a sheet with a thickness of 0.3 mm, the haze of the second transparent resin can be less than 8%, less than 7%, less than 6%, less than 5%, less than 4%, less than 3%, or less than 2.5%, and the haze can be more than 0.1%, more than 0.5%, or more than 1%.

[0096] According to one embodiment of the present invention, for a sheet with a thickness of 0.05 mm, the haze of the second transparent resin can be less than 5%, less than 4%, less than 3%, less than 2.5%, or less than 2%, and the haze can be more than 0.1%, more than 0.5%, or more than 1%.

[0097] According to one embodiment of the present invention, for a sample with a thickness of 3.2 mm, the transmittance (Tt) of the second transparent resin can be 70% or more, 75% or more, or 80% or more, and the transmittance (Tt) can be less than 100%, less than 95%, less than 90%, or less than 85%.

[0098] According to one embodiment of the present invention, for a sheet with a thickness of 0.3 mm, the transmittance (Tt) of the second transparent resin can be 80% or more, 85% or more, or 90% or more, and the transmittance (Tt) can be less than 100%, less than 95%, less than 93%, or less than 92%.

[0099] According to one embodiment of the present invention, for a sheet with a thickness of 0.05 mm, the transmittance (Tt) of the second transparent resin can be 80% or more, 85% or more, or 90% or more, and the transmittance (Tt) can be less than 100%, less than 95%, less than 93%, or less than 92%.

[0100] According to one embodiment of the present invention, the first transparent resin and the second transparent resin may have the same refractive index. Therefore, even when the second transparent resin film is laminated onto the first transparent resin film in a T-molding, the transparency of the transparent sheet can be maintained, and the increase in haze can be minimized. Here, "the same refractive index" means that the refractive index difference between the first transparent resin and the second transparent resin is less than ±0.1, less than ±0.01, less than ±0.001, less than ±0.0001, or less than ±0.00001, or there is no difference between them.

[0101] According to one embodiment of the present invention, if resins that meet physical properties are used as the first transparent resin and the second transparent resin respectively, then when manufacturing transparent sheets according to the present invention, weather resistance and chemical resistance can be further improved without deteriorating the transparency of the transparent sheets.

[0102] This invention provides a transparent sheet.

[0103] According to one embodiment of the present invention, the transparent sheet can be manufactured according to the above-described method for manufacturing transparent sheets. As a specific example, the transparent sheet may include: a T-shaped first transparent resin film layer; and a second transparent resin film layer laminated on at least one surface of the T-shaped first transparent resin film layer, wherein the first transparent resin is a graft copolymer comprising a conjugated diene polymer, the second transparent resin is a graft copolymer comprising an acrylic polymer, and the T-shaped first transparent resin film layer and the second transparent resin film layer each have a uniform thickness in the TD direction of the transparent sheet.

[0104] According to one embodiment of the present invention, the first transparent resin and the second transparent resin may be the same as those described in the method of manufacturing transparent sheets.

[0105] According to one embodiment of the present invention, since the thicknesses of the first and second transparent resin films of the T-die are uniform in the TD direction of the transparent sheet, the haze of the transparent sheet is unaffected, less warping occurs due to temperature, and the second transparent resin film can be formed thinly. This results in the first transparent resin film of the T-die exhibiting excellent transparency and color rendering, and sufficiently ensuring the impact resistance of the transparent sheet itself. Here, uniform thickness means that the thickness difference between the thickest and thinnest portions of the first and second transparent resin films of the T-die in the TD direction of the transparent sheet is less than ±0.05 mm, less than ±0.01 mm, less than ±0.005 mm, less than ±0.001 mm, or there is no difference between them.

[0106] According to one embodiment of the present invention, relative to the total thickness of the transparent sheet, the thickness of the first transparent resin film layer of the T-die can be 85% or more, 90% or more, or 95% or more and 99% or less, and the thickness of the second transparent resin film layer can be 1% or more and 15% or less, 10% or less or 5% or less. Within this range, not only can the impact resistance, heat resistance and scratch resistance of the transparent sheet be ensured by the first transparent resin film layer of the T-die, but also the weather resistance and chemical resistance can be ensured by the second transparent resin film layer without deteriorating the physical properties of the first transparent resin film layer of the T-die.

[0107] According to one embodiment of the present invention, the thickness of the first transparent resin film layer of the T-shaped mold can be 1 mm or more, 2 mm or more, 3 mm or more, or 4 mm or more, and can be less than 10 mm, 8 mm or less, 7 mm or less, or 6 mm or less. The thickness of the second transparent resin film layer can be 0.01 mm or more, 0.05 mm or more, or 0.10 mm or more, and can be less than 0.50 mm, 0.30 mm or less, or 0.15 mm or less. Within this range, not only can the first transparent resin film layer of the T-shaped mold ensure the impact resistance, heat resistance, and scratch resistance of the transparent sheet, but the second transparent resin film layer can also ensure the weather resistance and chemical resistance without deteriorating the physical properties of the first transparent resin film layer of the T-shaped mold.

[0108] According to one embodiment of the present invention, for a sample with a thickness of 3.2 mm as measured according to ASTM D1003, the total transmittance of the transparent sheet can be above 80%, above 81%, or above 81.5%, and the total transmittance can also be below 90%, below 88%, below 85%, or below 82%.

[0109] According to one embodiment of the present invention, for a sample with a thickness of 3.2 mm as measured according to ASTM D1003, the diffusion transmittance of the transparent sheet can be more than 1%, more than 2%, more than 3%, or more than 4%, and the diffusion transmittance can also be less than 10%, less than 8%, less than 6%, or less than 5%.

[0110] According to one embodiment of the present invention, for a sample with a thickness of 3.2 mm as measured according to ASTM D1003, the haze of the transparent sheet can be more than 1%, more than 2%, more than 3%, or more than 5%, and the haze can also be less than 10%, less than 8%, less than 7%, or less than 6%.

[0111] According to one embodiment of the present invention, for a specimen with a thickness of 3.2 mm as measured according to ASTM D2457, the gloss of the transparent sheet at 60° can be greater than 100, greater than 110, or greater than 120, and the gloss can be less than 150, less than 140, less than 130, or less than 125.

[0112] Embodiments of the invention will be described in detail below to enable those skilled in the art to readily implement the invention. However, the invention can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[0113] Example

[0114] Example 1

[0115] LG Chem's product name TR562-23316 (transparent ABS resin) was used as the first transparent resin, and LG Chem's product name LI901-INP (transparent ASA resin) was used as the second transparent resin.

[0116] A first transparent resin granule is placed into the hopper of an extruder 10 equipped with a T-die 11 and extruded at an extruder temperature of 210°C to discharge a 3mm thick T-die first transparent resin film TR1 from the T-die 11. While the T-die first transparent resin film TR1 discharged from the T-die 11 is directly fed to compression rollers 21 and 22, a 0.1mm thick second transparent resin film TR21 wound on a separate winding roller 41 is bonded to one surface of the T-die first transparent resin film TR1 and simultaneously fed between compression rollers 21 and 22. While passing through compression rollers 21 and 22, the T-die first transparent resin film TR1 and the second transparent resin film TR21 are laminated together, and a transparent sheet TS passes between compression rollers 21 and 23, and is then wound using a separate winding roller to manufacture the transparent sheet TS. In this case, the temperature of compression rollers 21 and 22 is 60°C.

[0117] Example 2

[0118] LG Chem's product name TR562-NP (transparent ABS resin) was used as the first transparent resin, and LG Chem's product name LI901-INP (transparent ASA resin) was used as the second transparent resin.

[0119] A first transparent resin granule is placed into the hopper of an extruder 10 equipped with a T-die 11 and extruded at an extruder temperature of 210°C to discharge a 3mm thick T-die first transparent resin film TR1 from the T-die 11. While the T-die first transparent resin film TR1 discharged from the T-die 11 is directly fed to compression rollers 21 and 22, second transparent resin films TR21 and TR22, each 0.1mm thick, wound on separate winding rollers 41, are bonded to one surface of the T-die first transparent resin film TR1 and simultaneously fed between compression rollers 21 and 22. Simultaneously, while passing through compression rollers 21 and 22, the T-die first transparent resin film TR1 and the second transparent resin films TR21 and TR22 are laminated together, and a transparent sheet TS passes between compression rollers 21 and 23, and is then wound using separate winding rollers to manufacture the transparent sheet TS. In this case, the temperature of compression rollers 21 and 22 is 60°C.

[0120] Comparative Example 1

[0121] In Example 1, the first transparent resin film TR1 of the T-shaped mold is manufactured as a transparent sheet without laminating the second transparent resin film TR21 onto the first transparent resin film TR1 of the T-shaped mold.

[0122] Comparative Example 2

[0123] In Example 2, the first transparent resin film TR1 of the T-shaped mold is manufactured as a transparent sheet without laminating the second transparent resin films TR21 and TR22 onto the first transparent resin film TR1 of the T-shaped mold.

[0124] Reference example 1

[0125] Commercially available polycarbonate resin is manufactured into transparent sheets.

[0126] Reference example 2

[0127] Commercially available polymethyl methacrylate resin is manufactured into transparent sheets.

[0128] Experimental Example 1: Evaluation of the optical properties of transparent sheets

[0129] Using the transparent sheets manufactured in Examples 1 and 2, and Comparative Examples 1 and 2, the chromaticity, total transmittance, diffuse transmittance, haze, and gloss were measured using the following method, and the results are listed in Table 1 below. Additionally, photographs of the transparent sheets manufactured in Examples 1 and 1 are shown below. Figure 4 In the image, the transparent sheets manufactured in Example 2 and Comparative Example 2 are photographed and shown. Figure 5 middle.

[0130] *Color coordinates: Color coordinates of the CIE LAB color space measured using a colorimeter.

[0131] *Total transmittance (Tt, %), diffuse transmittance (Td, %), and haze (haze, %): Total transmittance, diffuse transmittance, and haze were measured using an HM-150N (MURAKAMI COLORLAB Co., Ltd.) according to ASTM D1003 for a transparent sheet sample with an area of ​​40 mm × 80 mm and a thickness of 3.2 mm.

[0132] * Gloss: The gloss of a transparent sheet sample with an area of ​​40mm × 80mm and a thickness of 3.2mm was measured at 60° using Rhopoint IQ (Rhopoint Instruments Co., Ltd.) according to ASTM D2457.

[0133] [Table 1]

[0134]

[0135] As shown in Table 1, although the transparent sheet in Example 1 has a second transparent resin film laminated on one of its surfaces compared to the transparent sheet in Comparative Example 1, it can be confirmed that the color coordinates and transparency are almost unchanged, and thus the gloss is even increased while maintaining transparency.

[0136] Furthermore, although the transparent sheet of Example 2 has a second transparent resin film laminated on both surfaces compared to the transparent sheet in Comparative Example 2, it can be confirmed that the color coordinates and transparency are almost unchanged, and thus the gloss is even increased while maintaining transparency.

[0137] Experimental Example 2: Evaluation of the chemical resistance of transparent sheets

[0138] The chemical resistance of the transparent sheets manufactured in Examples 1 and 2, Comparative Examples 1 and 2, and Reference Examples 1 and 2 was measured using the following method, and the results are shown in Table 2 and... Figures 6 to 8 middle.

[0139] *Chemical resistance: According to ASTM D5419, a 3.2 mm thick dog bone-shaped transparent sheet sample was fixed to a fixture, and then isopropanol, ammonia and acetic acid were applied to it respectively. After 1 week, the presence of cracks and the time required for cracks to appear were observed.

[0140] [Table 2]

[0141]

[0142] As shown in Table 2 and Figure 6 As shown, it can be confirmed that the transparent sheet in Example 1 does not crack in any alcohols, alkalis and acids. Therefore, its chemical resistance is significantly improved compared to the transparent sheet in Comparative Example 1, which cracks in alcohols and acids.

[0143] Additionally, as shown in Table 2, Figure 7 and Figure 8 As shown, it can be confirmed that the transparent sheet in Example 2 does not crack in any alcohols, alkalis, acids and silicone resins. Therefore, compared with the transparent sheet in Comparative Example 2, which cracks in alcohols and acids, Reference Example 1, which cracks in acids and Reference Example 2, which cracks in alcohols, the chemical resistance is significantly improved.

[0144] Experimental Example 3: Evaluation of the weather resistance of transparent sheets

[0145] According to SAE J2527, using MV3000 metal halide (SUGA Co.), transparent sheets manufactured in Example 1 and Comparative Example 1 were exposed to a cumulative light dose of 299.52 MJ (approximately 95 days of xenon arc), and discoloration was observed. The results are as follows: Figure 9 As shown, it was confirmed that the transparent sheet in Example 1 did not undergo discoloration, while the transparent sheet in Comparative Example 1 did undergo discoloration.

[0146] Additionally, according to ASTM G155-1, using MV3000 metal halide (SUGA Co.), transparent sheets manufactured in Example 2, Comparative Example 2, and Reference Example 1 were exposed to a cumulative light dose of 252 MJ (approximately 84 days of xenon arc), and discoloration was observed. The results were as follows: Figure 10 As shown, it was confirmed that the transparent sheet in Example 2 did not undergo discoloration, while the transparent sheets in Comparative Example 2 and Reference Example 1 did undergo discoloration.

[0147] Experimental Example 4: Evaluation of the heat and cold resistance of transparent sheet 1

[0148] Using the transparent sheet manufactured in Example 1 and Comparative Example 1, a dog bone-shaped transparent sheet sample with a thickness of 3.2 mm was fixed onto a fixture, placed in a heat- and cold-resistant cycling chamber, and three cycles were repeated by setting one cycle to 2 hours at -20°C and 2 hours at 80°C and 85% relative humidity, and then observing for any peeling, changes in transparency and haze.

[0149] like Figure 11 As shown, it can be confirmed that even when the sample is exposed to the above-mentioned hot and cold cycling conditions, no peeling occurs between the first and second transparent resin film layers of the T-shaped mold, and the transparency and haze do not deteriorate.

[0150] Experimental Example 5: Evaluation of the heat and cold resistance of transparent sheet 2

[0151] Using transparent sheets manufactured in Examples 1 and 2, and Comparative Examples 1 and 2, dog-bone shaped transparent sheet samples with a thickness of 3.2 mm were fixed onto a fixture and placed in a heat- and cold-resistant cycling chamber. Three cycles were repeated: one cycle was set to be 3 hours at a surface temperature of 80°C, 3 hours at an ambient temperature of -40°C, and 7 hours at an ambient temperature of 50°C and 90% relative humidity. Changes in peeling, transparency, and haze were then observed, and the results are shown in Table 3 below. Figure 12 and Figure 13 middle.

[0152] [Table 3]

[0153]

[0154] like Figure 12 and Figure 13 As shown, it can be confirmed that even when the transparent sheet is exposed to the above-mentioned heat and cold resistance cycling conditions, no peeling occurs between the first transparent resin film layer and the second transparent resin film layer of the T-shaped mold in the transparent sheet of Examples 1 and 2.

[0155] Furthermore, as shown in Table 3, it can be confirmed that the degradation of transparency and haze of the transparent sheet of Example 1 was minimized compared with that of Comparative Example 1, and it can also be confirmed that the transparent sheet of Example 2 maintained the same level of transparency and haze as that of the transparent sheet of Comparative Example 2.

[0156] The results above confirm that when a transparent sheet is manufactured using the method for manufacturing transparent sheets according to the present invention, not only can the complexity of the manufacturing process that occurs during co-extrusion be solved, but the loss of raw material resin can also be minimized, and weather resistance and chemical resistance can be ensured without deterioration of the transparency of the transparent sheet.

Claims

1. A method for manufacturing a transparent sheet, the method comprising the following steps: S10, the first transparent resin film is extruded from the T-die; S20, the first transparent resin film extruded from the T-die is conveyed to the compression roller; S30, when the first transparent resin film is extruded from the T-die and fed into the compression roller, the second transparent resin film is fed into the compression roller together, and at the same time the second transparent resin film is bonded to at least one surface of the first transparent resin film; and S40, the first transparent resin film and the second transparent resin film are laminated using the compression roller. The first transparent resin is a graft copolymer comprising a conjugated diene polymer, aromatic vinyl monomer units, and vinyl cyanide monomer units, and the second transparent resin is a graft copolymer comprising an acrylic polymer, aromatic vinyl monomer units, and vinyl cyanide monomer units. The first transparent resin and the second transparent resin have the same refractive index.

2. The method of claim 1, wherein, During the extrusion process in step S10, the temperature of the extruder is 190°C to 210°C.

3. The method of claim 1, wherein, In step S30, the first transparent resin film and the second transparent resin film are bonded together while being fed into the compression roller.

4. The method of claim 1, wherein, In step S30, the second transparent resin film is unwound from the winding roller on which the second transparent resin film is wound and simultaneously conveyed to the compression roller.

5. The method of claim 1, wherein, In step S30, when the first transparent resin film is extruded from the T-die and fed into the compression roller, the second transparent resin film is simultaneously fed into the compression roller and bonded to both surfaces of the first transparent resin film.

6. The method of claim 1, wherein, During the lamination process in step S40, the temperature of the compression roller is 40°C to 70°C.

7. The method of claim 1, wherein, The second transparent resin film, with a thickness of 3.2 mm, has a haze of less than 10%.

8. The method of claim 1, wherein, The second transparent resin film sample with a thickness of 3.2 mm has a transmittance of over 70%.

9. A transparent sheet material, comprising: First transparent resin film; and A second transparent resin film laminated on at least one surface of the first transparent resin film. The first transparent resin is a graft copolymer comprising conjugated diene polymers, aromatic vinyl monomer units, and vinyl cyanide monomer units. The second transparent resin is a graft copolymer comprising acrylic polymers, aromatic vinyl monomer units, and vinyl cyanide monomer units. The first transparent resin film and the second transparent resin film each have a uniform thickness in the transverse direction of the transparent sheet. The first transparent resin and the second transparent resin have the same refractive index.

10. The transparent sheet material according to claim 9, wherein, The thickness of the first transparent resin film is 85% to 99% relative to the total thickness of the transparent sheet, and the thickness of the second transparent resin film is 1% to 15%.

Images