CN-121973516-A - Resin sheet and resin molded body

Abstract

The invention provides a resin sheet and a resin molded body, which can use a thermoplastic resin with high load deflection temperature and simultaneously has light weight and strength. The resin sheet (1) is composed of a thermoplastic resin, and comprises a core layer (2) as a foamed resin layer and a surface layer (3) continuously formed outward in the thickness direction of the core layer (2). The core layer (2) comprises a region (A1) and a region (A2) positioned between the region (A1) and the two surface layers (3). The region (A2) has an average void fraction smaller than the region (A1) and smaller than 50%. The thermoplastic resin has a load deflection temperature of 90 ℃ or more. The resin sheet has a thickness of 1 to 40 mm. The surface layer has a thickness of 5 to 50% of the thickness of the resin sheet. In this way, in the thermoplastic resin having a load deflection temperature of 90 ℃ or higher, the thickness of the resin sheet and the thickness of the surface layer can be appropriately set, whereby both the light weight and the strength can be achieved.

Inventors

• You Zuodun
• Shui Gugui
• YAMAMOTO SATOSHI
• GOTO TOSHIHARU
• TANIGUCHI TAKAO

Assignees

• 麦克赛尔株式会社

Dates

Publication Date

20260505

Application Date

20221008

Priority Date

20211011

Claims (9)

1. 1. A resin sheet comprising a thermoplastic resin, characterized by comprising: A core layer as a foaming resin layer, and A surface layer continuously formed outward in the thickness direction of the core layer, The core layer comprises a first region and a second region positioned between the first region and the two surface layers, The first region has an average void fraction of 50% -95%, The second region has an average void fraction of less than 50% and less than the first region, The thermoplastic resin has a load deflection temperature of 90 ℃ or more, The resin sheet has a thickness of 1 to 40mm, The average void fraction of the second region continuously gradually decreases from the center in the thickness direction of the core layer toward the surface of the resin sheet, The surface layer has a thickness of 5 to 50% of the thickness of the resin sheet and is composed of a thermoplastic resin having a load deflection temperature of 90 ℃ or more, The resin sheet has a flexural modulus of elasticity of 3GPa or more and a density of 1.3g/cm3 or less.
2. 2. The resin sheet according to claim 1, wherein, The breaking probability of the test piece in the Charpy impact test, which was based on ISO179-1 standard, was 0%, and each of the test pieces was subjected to a flat-wound vertical test under a notch-free condition, and the presence or absence of breaking was evaluated using a 4J vibrator.
3. 3. The resin sheet according to claim 1, wherein, The first region has an average void fraction of 65% -90%.
4. 4. The resin sheet according to claim 1, wherein, The surface layer is composed of a reinforcing resin containing an inorganic filler.
5. 5. The resin sheet according to any one of claim 1 to 4, wherein, The surface layer has a flexural modulus of elasticity that is 1.5 times or more the flexural modulus of elasticity of the core layer.
6. 6. The resin sheet according to any one of claim 1 to 4, wherein, The resin sheet has a load deflection temperature of 150 ℃ or more, a flexural modulus of 3GPa or more, and a density of 1.3g/cm3 or less.
7. 7. The resin sheet according to any one of claim 1 to 4, wherein, The thermoplastic resin contains at least one selected from the group consisting of polycarbonate, modified polyphenylene ether, syndiotactic polystyrene, polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, polyamideimide, thermoplastic polyimide, polyetherimide, and liquid crystal polymer.
8. 8. The resin sheet according to any one of claim 1 to 4, wherein, The average void ratio is obtained from the ratio of the cross-sectional areas of the foaming units per unit cross-sectional area in the resin sheet.
9. 9. A resin molded article characterized in that, A resin sheet according to any one of claims 1 to 8, which is formed by heating and shaping.

Description

Resin sheet and resin molded body The present invention is a divisional application of the invention patent application having the national application number 202211223399.0 (International application number PCT/JP 2021/037500) and the invention creation name "resin sheet and resin molded body". Technical Field The present disclosure relates to a resin sheet using engineering plastics and super engineering plastics as resin materials, and a resin molded body composed of the resin sheet. Background In recent years, foamed resins have been attracting attention because of their ability to reduce carbon dioxide emissions by reducing the weight of resin molded articles. As a foam molding method of the foaming resin, there are physical foam molding and chemical foam molding. The chemical foaming molding has high environmental load and has great influence on the environment. Therefore, physical foam molding using a physical foaming agent such as nitrogen or carbon dioxide has been studied. As a method for foaming engineering plastics and super engineering plastics having high heat resistance, there is a method of shearing and kneading a molten resin of engineering plastics and super engineering plastics and a high-pressure supercritical fluid to dissolve them. Japanese patent No. 6139038 (patent document 1) discloses a method for producing a foam molded body using a physical foaming agent such as nitrogen or carbon dioxide at a relatively low pressure without requiring a supercritical fluid. According to this method, a fine foaming unit can be formed on a resin molded body by a relatively simple process using a low-pressure physical foaming agent without using a special high-pressure apparatus. The molding method of the foaming resin includes an injection molding method capable of obtaining a resin molded article having a complicated shape and an extrusion molding method capable of continuously obtaining a resin molded article having a single shape. In the injection molding method, when a foamed resin is molded, a surface layer of the molten resin flows in a mold while cooling and solidifying, and thus a non-foamed surface layer is formed on a surface layer of a resin molded body. On the other hand, the extrusion molding method is suitable for producing a resin molded article having a single thickness because the size and load of the mold are less limited than the injection molding method, and it is also possible to obtain a resin molded article having a somewhat complicated shape and a large size by vacuum molding or the like after obtaining a resin molded article having a thin plate shape by extrusion molding. However, in the extrusion molding method, the molten resin expands by foaming at the time of ejection from a die (mold), and then cools and solidifies, but it is difficult to form a surface layer on the surface layer of the resin molded body. Japanese patent No. 3654697 (patent document 2) discloses a method for producing a thermoplastic resin foamed sheet capable of easily forming a surface layer on the surface of the thermoplastic resin foamed sheet by extrusion molding. Further, japanese patent application laid-open No. 2000-52370 (patent document 3) discloses a method for producing a multilayer laminated molded body having a foamed layer and a surface layer by coextrusion molding. In the method for producing the thermoplastic resin foamed sheet of patent document 2 and the method for producing the multilayer laminated molded article of patent document 3, a general-purpose plastic having relatively low heat resistance and strength such as polypropylene or polystyrene is used as a main resin material, and engineering plastics and super engineering plastics having excellent heat resistance and strength are not used. The production methods of patent documents 2 and 3 are not aimed at improving heat resistance and strength, but aimed at ease of production or stability of the foam molded product. Japanese patent No. 3568655 (patent document 4) discloses a polycarbonate resin extrusion foam laminated sheet obtained by bonding a plurality of polycarbonate resin extrusion foam sheets. However, the polycarbonate resin extrusion-molded laminate sheet of patent document 4 is a relatively thick polycarbonate resin foam sheet obtained by cutting and laminating a polycarbonate resin extrusion-molded laminate sheet, and is not a surface layer of a control surface layer. JP-A06-79816 (patent document 5) discloses a multilayer high molecular weight polycarbonate resin foam in which the weight average molecular weight of the surface layer is 1.15 times or more higher than that of the other layers. The multilayer high molecular weight polycarbonate resin foam of patent document 5 suppresses the decrease in the strength of the skin layer by decreasing the foam density of the skin layer of the high molecular weight polycarbonate resin foam, and does not precisely control the mechanical strength of the skin layer and the mec