Laminate

Abstract

To provide a laminate which uses a bio-polycarbonate resin in a surface layer, has excellent moldability, and easily maintains unevenness (embossment) formed on the surface of the surface layer even if vacuum molding is performed.SOLUTION: A laminate has a surface layer 1 and a core layer 2, wherein the surface layer 1 contains a polycarbonate-based resin having a structural unit derived from isosorbide, and storage elastic modulus at 190°C of the surface layer 1 is 0.4 Pa or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate having a surface layer and a core layer. [Background technology]

[0002] In recent years, for example, polycarbonate resins, which have excellent impact resistance, heat insulation properties, etc., have come to be used in interior and exterior components of automobiles in order to reduce the weight of automobiles and improve their design.

[0003] On the other hand, bio-polycarbonate resins, which are made primarily from plant-derived isosorbide, have been proposed as polycarbonate resins that contribute to the realization of a carbon-free society and have been put to practical use (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-196158 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention aims to provide a laminate that uses a bio-polycarbonate resin for the surface layer, has good formability, and easily maintains the unevenness (embossment, etc.) formed on the surface of the surface layer even when vacuum forming is performed. [Means for solving the problem]

[0006] In order to achieve the above object, the laminate of the present invention is a laminate having a surface layer and a core layer, wherein the surface layer contains a polycarbonate-based resin having a structural unit derived from isosorbide, and the storage modulus of the surface layer at 190°C is 0.4 Pa or more.

[0007] In this case, the polycarbonate resin having structural units derived from isosorbide contained in the surface layer may contain more than 50 mol % of structural units derived from isosorbide and less than 50 mol % of structural units derived from 1,4-cyclohexanedimethanol.

[0008] The surface layer may have a Vicat softening temperature of 114 to 140°C.

[0009] Furthermore, the difference in 60° gloss value of the surface of the surface layer before and after vacuum forming can be 8% or less.

[0010] Furthermore, the surface of the surface layer may be formed with irregularities. [Effects of the Invention]

[0011] The laminate of the present invention contains a polycarbonate resin having structural units derived from plant-derived isosorbide in the surface layer, and the storage modulus of the surface layer at 190°C is 0.4 Pa or more, so that it has good formability and the unevenness (embossment, etc.) formed on the surface of the surface layer is easily maintained even when vacuum forming is performed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram showing a laminate structure of an embodiment of a laminate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the laminate of the present invention will be described.

[0014] FIG. 1 shows a laminate structure diagram of one embodiment of the laminate of the present invention. This laminate has a surface layer 1 and a core layer 2, and the surface layer 1 contains a polycarbonate resin having structural units derived from plant-derived isosorbide, and the storage modulus of the surface layer 1 at 190°C is 0.4 Pa or more.

[0015] An example of a polycarbonate resin having structural units derived from isosorbide that constitutes the surface layer 1 is the "Durabio (registered trademark)" series of bioengineering plastics manufactured by Mitsubishi Chemical Corporation, which uses plant-derived isosorbide as its main raw material. This bio-polycarbonate resin has high transparency, excellent optical properties, and excellent scratch resistance. It also has impact resistance comparable to that of general-purpose polycarbonate resin made from bisphenol A, and exhibits higher chemical resistance than general-purpose polycarbonate resin.

[0016] The storage modulus of the surface layer 1 at 190°C is 0.4 Pa or more, preferably 0.5 Pa or more, and more preferably 0.6 Pa or more. If the storage modulus of the surface layer 1 at 190°C is less than 0.4 Pa, the change in glossiness before and after vacuum forming is large, and the desired texture may not be obtained.

[0017] The polycarbonate resin having structural units derived from isosorbide contained in the surface layer 1 preferably contains more than 50 mol% of structural units derived from isosorbide and less than 50 mol% of structural units derived from 1,4-cyclohexanedimethanol. From the viewpoint of suppressing changes in gloss before and after vacuum processing, the polycarbonate resin more preferably contains more than 55 mol% of structural units derived from isosorbide and less than 45 mol% of structural units derived from 1,4-cyclohexanedimethanol, and even more preferably contains more than 60 mol% of structural units derived from isosorbide and less than 40 mol% of structural units derived from 1,4-cyclohexanedimethanol.

[0018] The Vicat softening temperature of the polycarbonate resin having structural units derived from isosorbide that constitutes the surface layer 1 is preferably 114 to 140° C., more preferably 120 to 138° C., and even more preferably 125 to 135° C. If the Vicat softening temperature is less than 114° C., there is a risk that the heat resistance during use will be insufficient, and if it exceeds 140° C., there will be a large change in gloss before and after vacuum forming, and the desired texture may not be obtained.

[0019] The difference in 60° gloss value before and after vacuum forming of the surface of the surface layer 1 is preferably 8% or less, more preferably 7.5% or less, and even more preferably 7% or less. If the difference in 60° gloss value exceeds 8%, the gloss state before and after vacuum forming will change significantly, and the desired texture may not be obtained.

[0020] The thickness of the surface layer 1 is preferably 30 to 200 μm, more preferably 50 to 100 μm, for reasons of performance, cost, productivity, etc.

[0021] The surface of the surface layer 1 may be a smooth plane or may have irregularities formed thereon. Methods for forming irregularities on the surface include, for example, press processing (embossing, texturing), laser processing, end mill processing, and lithography. Alternatively, a mold having an irregular structure on the surface may be produced by molding using a metal 3D printer. Examples of embossing include a method using an embossing mold roll and a method using an embossing press plate. can be done.

[0022] The core layer 2 is not particularly limited, and may be made of, for example, one or more selected from acrylic resins, vinyl resins, urethane resins, polyester resins, polypropylene resins, polyethylene resins, polystyrene resins, polycarbonate resins, vinylon resins, acetate resins, polyamide resins, silicone resins, fluorine resins, and copolymers thereof.

[0023] Specifically, this laminate can be formed using the following materials and forming method.

[0024] [material] ○Surface layer 1 (thickness 50 to 100 μm) Bio PC1: "Durabio (registered trademark) D5380R" (Mitsubishi Chemical Corporation) Polycarbonate resin with structural units derived from isosorbide (ISB / CHDM=50 / 50) It has higher pencil hardness and better chemical resistance than general polycarbonate resin. Melt Volume Rate (MVR): 4cm 3 / 10min, deflection temperature under load: 82℃ Bio PC2: "Durabio (registered trademark) D7340IR" (Mitsubishi Chemical Corporation) Polycarbonate resin with structural units derived from isosorbide (ISB / CHDM=70 / 30) It has higher pencil hardness and better chemical resistance than general polycarbonate resin. Melt Volume Rate (MVR): 8cm 3 / 10min, deflection temperature under load: 102℃ ○ Core layer 2 (thickness 1.35~1.65mm) PC: "Caliber (product name) 300-8" (manufactured by Sumika Polycarbonate Co., Ltd.) Made of general polycarbonate resin, it has excellent impact resistance. Melt Volume Rate (MVR): 8cm 3 / 10min

[0025] [Molding method (molding conditions)] Co-extrusion molding The material for surface layer 1 (bio-PC) and the material for core layer 2 (PC) are melted and kneaded in an extruder, and the two layers of resin extruded from the die are glossed with a polishing roll at a temperature of 100-180°C and formed into a sheet. After forming, the sheet is heat-pressed at a surface temperature of 170°C using a press plate with an embossed pattern to emboss the surface. Here, the material for the surface layer 1 (bio-PC) is extruded through a die at 200 to 250°C, and the material for the core layer 2 (PC) is extruded at 240 to 280°C. ○Vacuum forming The sheet is heated to 200-300°C, and a two-stage box-shaped mold is pressed against it before and after the sheet is drawn down (45 seconds) to perform vacuum forming.

[0026] [Evaluation method] Vicat softening temperature The Vicat softening temperature was measured in accordance with JIS-K7206:2016 using the following equipment. Measurement equipment: Heat distortion tester / deflection temperature tester "148-HD-3" (Yasuda Seiki Seisakusho) Glass transition temperature The glass transition temperature was measured in accordance with JIS-K7121:1987 using the following equipment. Measuring equipment: Rheometer / viscoelasticity measuring device "DHR-2" (manufactured by TA Instruments) Storage modulus The storage modulus was measured under the following conditions in accordance with JIS-K7244-4. Measurement temperature: 190℃ Measuring equipment: Dynamic viscoelasticity measuring device "DMA-Q800" (TA Instruments) ○Gloss The 60° gloss of the surface of the surface layer was measured in accordance with JIS-Z8741:1997. Measuring equipment: Gloss checker "IG-320" (manufactured by Horiba Ltd.) ○Workability The state of the sheet after vacuum forming was visually inspected and evaluated according to the following criteria. 〇: Can be molded exactly as the mold suggests. ×: Unable to mold according to the mold.

[0027] Examples and comparative examples of this laminate are shown in Table 1.

[0028] [Table 1]

[0029] From Table 1, the following points were confirmed: The laminates of Examples 1 to 4 (surface layer material (bio-PC): structural units derived from isosorbide are greater than 50 mol % and structural units derived from 1,4-cyclohexanedimethanol are less than 50 mol %) use a bio-polycarbonate resin for the surface layer, have good formability, and have a storage modulus of the surface layer at 190°C of 0.4 Pa or more (preferably 0.5 Pa or more, more preferably 0.6 Pa or more). Even when molded (vacuum molded) to a predetermined product shape after sheet molding (co-extrusion molding), the laminates easily maintain the shape of the irregularities (embossments) 11 formed on the surface of the surface layer 1 during sheet molding (co-extrusion molding). The laminates of Examples 1 to 4 have a gloss change of 8 or less before and after vacuum forming, and can maintain a small change in the gloss of the surface of the surface layer even after vacuum forming. Here, in order to suppress the change in gloss before and after vacuum processing, it is preferable that the structural units derived from isosorbide are more than 50 mol% and the structural units derived from 1,4-cyclohexanedimethanol are less than 50 mol%, more preferably the structural units derived from isosorbide are more than 55 mol% and the structural units derived from 1,4-cyclohexanedimethanol are less than 45 mol%, and even more preferably the structural units derived from isosorbide are more than 60 mol% and the structural units derived from 1,4-cyclohexanedimethanol are less than 40 mol%. It is less than 1%.

[0030] The laminate of the present invention has been described above based on its embodiment, but the present invention is not limited to the above configuration, and the configuration can be changed as appropriate within the scope of the invention. [Industrial Applicability]

[0031] The laminate of the present invention uses a bio-polycarbonate resin for the surface layer, has good formability, and is easy to maintain the unevenness (embossing, etc.) formed on the surface of the surface layer even when vacuum-molded. Therefore, it can be suitably used, for example, in laminates used in interior and exterior components of automobiles for the purpose of reducing the weight of automobiles and improving their design. [Explanation of symbols]

[0032] 1 Surface layer 11 Embossing 2 Core layer

Claims

1. A laminate having a surface layer and a core layer, The surface layer is It contains a polycarbonate resin having a structural unit derived from isosorbide, The surface layer has a storage modulus of 0.4 Pa or more at 190°C. A laminate characterized by:

2. The polycarbonate resin having a structural unit derived from isosorbide contained in the surface layer is The structural unit derived from isosorbide is greater than 50 mol %, The structural unit derived from 1,4-cyclohexanedimethanol is less than 50 mol % The laminate according to claim 1 .

3. The Vicat softening temperature of the surface layer is 114 to 140°C.

3. The laminate according to claim 1 or 2.

4. The difference in 60° gloss value of the surface of the surface layer before and after vacuum forming is 8% or less.

3. The laminate according to claim 1 or 2.

5. The surface of the surface layer is formed with irregularities.

3. The laminate according to claim 1 or 2.

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