Resin molded articles and laminated resin sheets

Abstract

To provide a resin molded article with high strength and excellent processability. [Solution] The resin molded article comprises a first resin which is a thermoplastic resin, a second resin which is a liquid crystal polymer, and a copolymer of polycarbonate and polyester, wherein the melting point of the second resin is below the temperature at which the melt viscosity of the first resin becomes 4000 Pa·s. However, the melt viscosity is 150 sec. -1 The value measured at the shear rate is to be used.

Description

Technical Field

[0001] The present invention relates to a resin molded body and a laminated resin sheet.

Background Art

[0002] Two or more types of resins are blended to improve the properties of the resin. Also, at that time, a compatibilizer is added to improve the compatibility of two or more types of resins.

[0003] Japanese Unexamined Patent Application Publication No. 2010-106186 discloses a compatibilizer for compatibilizing thermoplastic resins having different polarities and biomass-derived resins. This compatibilizer contains a polyester (A) composed of an alkylene oxide adduct (a1) of a bisphenol compound and a dicarboxylic acid (a2), and an ethylenically unsaturated monomer copolymer (B).

[0004] Japanese Unexamined Patent Application Publication No. 2000-234063 discloses a modifier for imparting impact resistance and the like to a thermoplastic resin. This modifier contains a hydrogenated styrene-based thermoplastic elastomer and a compatibilizer. The compatibilizer is at least one selected from (a) a copolymer composed of an aromatic vinyl monomer and a monomer copolymerizable with the aromatic vinyl monomer, and (b) a rubbery polymer having a glass transition temperature (Tg) of -30°C or lower and a graft copolymer composed of an aromatic vinyl monomer (M1) grafted thereto and a monomer (M2) copolymerizable with the aromatic vinyl monomer (M1).

[0005] Japanese Unexamined Patent Application Publication No. 2007-302845 discloses a compatibilizer composition for blending a crystalline polyester resin with a polycarbonate and / or a liquid crystalline polyester resin. This compatibilizer composition consists of an amorphous polyester resin (I) and a reactive compound (II) containing two or more glycidyl groups and / or isocyanate groups per molecule and having a weight average molecular weight of 200 or more and 500,000 or less.

[0006] Japanese Patent Publication No. 3-185049 discloses a thermoplastic resin composition comprising (a) a polyphenylene ether resin, (b) a polyester resin, and (c) a compatibilizer consisting of a polycarbonate-polyester copolymer. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2010-106186 [Patent Document 2] Japanese Patent Publication No. 2000-234063 [Patent Document 3] Japanese Patent Publication No. 2007-302845 [Patent Document 4] Japanese Patent Application Publication No. 3-185049 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Adding inorganic fillers such as glass fibers is a common method to improve the strength of resin molded articles. However, inorganic fillers do not melt even at high temperatures, which reduces the formability of the resin. In particular, it reduces processability during vacuum forming.

[0009] One objective of the present invention is to provide a resin molded article with high strength and excellent processability. Another objective of the present invention is to provide a laminated resin sheet with high strength and excellent processability. [Means for solving the problem]

[0010] A resin molded article according to one embodiment of the present invention comprises a first resin which is a thermoplastic resin, a second resin which is a liquid crystal polymer, and a copolymer of polycarbonate and polyester, wherein the melting point of the second resin is below the temperature at which the melt viscosity of the first resin becomes 4000 Pa·s. However, the melt viscosity is 150 sec. -1 The value measured at the shear rate is to be used.

[0011] A laminated resin sheet according to one embodiment of the present invention comprises a core layer made of foamed resin and a skin layer made of non-foamed resin, which is laminated on the main surface of the core layer, wherein the skin layer is a layer made of the resin molded body described above. [Effects of the Invention]

[0012] According to the present invention, a resin molded article and a laminated resin sheet with high strength and excellent processability can be obtained. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic perspective view showing the structure of a laminated resin sheet according to one embodiment of the present invention. [Modes for carrying out the invention]

[0014] The inventors of the present invention investigated adding a low-melting-point liquid crystal polymer (hereinafter referred to as "low-melting-point liquid crystal polymer") to a thermoplastic resin in order to improve the strength of a molded resin article.

[0015] When a thermoplastic resin and a low-melting-point liquid crystal polymer were kneaded together, a structure was formed in which the low-melting-point liquid crystal polymer was finely dispersed within the matrix of the thermoplastic resin. However, the adhesion between the thermoplastic resin and the low-melting-point liquid crystal polymer was low, and voids existed at the interface between the two. Therefore, the effect of improving strength was limited. Furthermore, the mixture of thermoplastic resin and low-melting-point liquid crystal polymer did not exhibit good moldability in vacuum forming.

[0016] The inventors have found that a copolymer of polycarbonate and polyester is suitable as a compatibilizer to improve the compatibility between thermoplastic resins and low-melting-point liquid crystal polymers. By kneading the thermoplastic resin and low-melting-point liquid crystal polymer with this copolymer, the strength and moldability of the resin molded article were improved.

[0017] The present invention has been completed based on the above findings. Hereinafter, a resin molded body and a laminated resin sheet according to an embodiment of the present invention will be described in detail.

[0018] [Resin Molded Body] The resin molded body according to an embodiment of the present invention includes a first resin that is a thermoplastic resin, a second resin that is a liquid crystal polymer, and a copolymer of polycarbonate and polyester. The melting point of the second resin is not higher than the temperature at which the melt viscosity of the first resin becomes 4000 Pa·s. However, the melt viscosity is the value measured at a shear rate of 150 sec -1 and shall be the value measured at a shear rate of 150 sec.

[0019] [First Resin] The resin molded body according to the present embodiment includes a first resin that is a thermoplastic resin. The first resin preferably is a thermoplastic resin having a heat deflection temperature of 90°C or higher. The heat deflection temperature can be determined in accordance with ISO75-2B (1.81 MPa load).

[0020] The first resin preferably is an engineering plastic or a super engineering plastic.

[0021] An engineering plastic is a thermoplastic resin having a heat deflection temperature of 100°C or higher. Specifically, for example, polycarbonate (PC), modified polyphenylene ether (m-PPE), syndiotactic polystyrene (SPS), polybutylene terephthalate (PBT), polyacetal (POM), polyethylene terephthalate (PET), polyamide (PA), etc. may be mentioned. Among them, polycarbonate is preferable.

[0022] Super engineering plastics are thermoplastic resins having a load deflection temperature of 150°C or higher. Specific examples include polyphenylsulfone (PPSU), polysulfone (PSU), polyarylate (PAR), polyetherimide (PEI), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyethersulfone (PES), polyamideimide (PAI), polyvinylidene fluoride (PVDF), and tetrafluoroethylene perfluoroalkyl vinyl copolymer (PFA).

[0023] The first resin is preferably one having an aromatic ring, and is particularly preferably an aromatic polycarbonate, and is preferably one synthesized from 2,2-bis(4-hydroxyphenylpropane).

[0024] [Second resin] The resin molded article according to this embodiment includes a second resin, which is a liquid crystal polymer with a low melting point. Liquid crystal polymers are, for example, aromatic polyesters and aromatic polyesteramides synthesized from aromatic hydroxycarboxylic acids, etc. Liquid crystal polymers are, but are not limited to these, copolymers that typically contain structural units derived from parahydroxybenzoic acid, and various grades with different melting points are available on the market by adjusting the copolymerized components, etc. The liquid crystal polymer used as the second resin in this embodiment is a liquid crystal polymer with a low melting point (low-melting point liquid crystal polymer) among such liquid crystal polymers.

[0025] The second resin is, more specifically, a liquid crystal polymer having a melting point below the temperature at which the melt viscosity of the first resin becomes 4000 Pa·s (hereinafter referred to as the "reference temperature"). However, the melt viscosity is 150 sec. -1 The value measured at the shear rate is to be used.

[0026] In this configuration, when the first resin is heated to form a resin molded article, the second resin, which is a low-melting-point liquid crystal polymer, is finely dispersed within the first resin. This improves the strength of the resin molded article. If the melting point of the second resin is higher than the molding temperature of the first resin, the second resin will not melt near the molding temperature of the first resin, making molding impossible. If the heating temperature is increased to disperse the second resin, the melt viscosity of the first resin decreases too much, making it difficult to properly mix the first and second resins.

[0027] The melting point of the second resin is preferably lower than the reference temperature, but close to the reference temperature. If the melting point of the second resin is too low, the difference in melt viscosity between it and the first resin may become too large, making proper mixing impossible. Therefore, the lower limit of the melting point of the second resin may be 40°C lower than the reference temperature, or 30°C lower than the reference temperature.

[0028] If the first resin is polycarbonate, the melt viscosity (150 sec -1 The temperature at which the melt viscosity (measured at a shear rate) reaches 4000 Pa·s is approximately 260°C, although this depends on the grade of the polycarbonate, etc. Therefore, when the first resin is polycarbonate resin, the melting point of the second resin may be 260°C or lower. When the first resin is polycarbonate, the melting point of the second resin is more preferably 250°C or lower. The lower limit of the melting point of the second resin may be, for example, 220°C.

[0029] The mass ratio of the first resin to the second resin is preferably 99:1 to 90:10. If the proportion of the second resin is too low, the effect of improving strength will not be sufficiently obtained. On the other hand, if the proportion of the second resin is too high, the elongation will be poor and the moldability will decrease. More preferably, the mass ratio of the first resin to the second resin is 98:2 to 93:7.

[0030] [Copolymer of polycarbonate and polyester] The resin molded article according to this embodiment further comprises a copolymer of polycarbonate and polyester. The copolymer of polycarbonate and polyester improves the compatibility between the first resin and the second resin. By including the copolymer of polycarbonate and polyester in the resin molded article, the adhesion between the first resin and the second resin, which is finely dispersed in the first resin, is improved, thereby improving the strength and moldability of the resin molded article.

[0031] The polycarbonate constituting the above copolymer may be an aliphatic polycarbonate or an aromatic polycarbonate, but it is preferably an aromatic polycarbonate, and particularly preferably one derived from 2,2-bis(4-hydroxyphenyl)propane.

[0032] The polyesters constituting the above copolymer are not limited to those listed above, but polybutylene succinate (PBS), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), polyethylene naphthalate (PEN), polytrimethylene terephthalate (PMT), polyethylene terephthalate (PET), etc., can be used. Among these, PBS and PBT are preferred.

[0033] The ratio of polycarbonate to polyester is not particularly limited and may be, for example, 10:90 to 90:10 in molar ratio. Preferably, the ratio of polycarbonate to polyester is 20:80 to 80:20 in molar ratio, and more preferably 30:70 to 70:30.

[0034] The copolymer of polycarbonate and polyester is preferably a block copolymer or a random copolymer, and more preferably a block copolymer.

[0035] A copolymer of polycarbonate and polyester can be produced, for example, by melt-mixing the aforementioned polycarbonate and polyester in the presence of a catalyst.

[0036] The copolymer of polycarbonate and polyester may contain components other than polycarbonate and polyester. The copolymer of polycarbonate and polyester may contain, for example, structural units derived from polyhydric alcohols. The proportion of components other than polycarbonate and polyester is preferably 30 mol% or less of the total copolymer, preferably 10 mol% or less, more preferably 5 mol% or less, and even more preferably 3 mol% or less. Furthermore, the proportion of components other than polycarbonate and polyester is preferably 30 wt% or less of the total copolymer, preferably 10 wt% or less, more preferably 5 wt% or less, and even more preferably 3 wt% or less.

[0037] The copolymer of polycarbonate and polyester preferably has a number-average molecular weight Mn of 30,000 or less. The copolymer of polycarbonate and polyester preferably has a weight-average molecular weight Mw of 50,000 or less. Furthermore, the degree of dispersion (Mw / Mn) is preferably 1.0 to 2.5. By setting the molecular weight within these ranges, the dispersibility in the base resin is improved, and the effect as a compatibilizer is enhanced. The lower limit of the number-average molecular weight Mn is not particularly limited, but may be, for example, 8,000. The lower limit of the weight-average molecular weight Mw is not particularly limited, but may be, for example, 12,000.

[0038] The amount of the copolymer of polycarbonate and polyester (hereinafter simply referred to as "polymer" in this paragraph) is preferably 0.5 to 15 wt% of the total resin molded article. If the amount of copolymer is too small, the effect of improving the compatibility between the first resin and the second resin may not be sufficiently obtained. If the amount of copolymer is too large, the effect of improving the properties by blending the first resin and the second resin may not be sufficiently obtained. The amount of copolymer is more preferably 0.8 to 12 wt% of the total resin molded article, and even more preferably 0.8 to 5 wt%.

[0039] [Other ingredients] The resin molded article according to this embodiment may contain components other than the first resin, the second resin, and the copolymer of polycarbonate and polyester described above. The resin molded article may contain, for example, a third resin which is a thermoplastic resin different from the first resin and the second resin. The amount of components other than the first resin, the second resin, and the copolymer of polycarbonate and polyester is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 2 parts by mass or less, based on 100 parts by mass of the total of the first resin and the second resin.

[0040] [Shape, mechanical properties, etc. of the resin molded product] The shape of the resin molded article according to this embodiment is not particularly limited. The shape of the resin molded article may be, for example, a sheet, a wire, a block, or a complex shape. The resin molded article may also be a foamed molded article or a non-foamed molded article (solid product).

[0041] When the resin molded body is in the form of a sheet, its thickness is preferably 1.0 to 4.0 mm. This facilitates thermal shaping during vacuum forming.

[0042] When the shape of the resin molded body is sheet-like, it is preferable that the resin molded body is an extruded molded body formed by extrusion molding, as described later.

[0043] The resin molded article preferably has a flexural modulus of 2200 MPa or higher and a yield stress of 100 MPa or higher. The flexural modulus and yield stress shall be measured at room temperature (23°C) in accordance with JIS K7171:2016 or ISO 178. The lower limit of the flexural modulus of the resin molded article is more preferably 2300 MPa. The upper limit of the flexural modulus of the resin molded article is not particularly limited, but may be, for example, 3000 MPa. The lower limit of the yield stress of the resin molded article is more preferably 120 MPa. The upper limit of the yield stress of the resin molded article is not particularly limited, but may be, for example, 150 MPa.

[0044] [Method for manufacturing resin molded products] The resin molded article according to this embodiment can be manufactured, for example, by mixing the first resin, the second resin, and a copolymer of polycarbonate and polyester described above, as well as other components added as needed, heating and kneading the mixture to a temperature suitable for molding (e.g., 260-300°C), and then molding it into a predetermined shape using any molding method.

[0045] While not limited to these methods, injection molding and extrusion molding are representative methods for molding resin articles. Injection molding allows for the production of resin articles with complex shapes. On the other hand, extrusion molding has fewer limitations on mold size and load than injection molding and is suitable for the continuous production of resin articles with a single shape and thickness. Furthermore, sheet-like resin articles obtained by extrusion molding can be shaped into somewhat complex shapes or relatively large sizes by vacuum forming or pressure forming.

[0046] [Effects of the resin molded article according to this embodiment] The above describes a resin molded article according to one embodiment of the present invention. The resin molded article according to this embodiment includes a first resin, which is a thermoplastic resin; a second resin, which is a low-melting-point liquid crystal polymer; and a copolymer of polycarbonate and polyester. With this configuration, when the first resin is heated to mold the resin molded article, the second resin, which is a low-melting-point liquid crystal polymer, is finely dispersed in the first resin. This improves the strength of the resin molded article. Furthermore, by including the copolymer of polycarbonate and polyester in the resin molded article, the adhesion between the first resin and the second resin, which is finely dispersed in the first resin, is improved, improving the strength and moldability of the resin molded article. Therefore, according to this embodiment, a resin molded article with high strength and excellent processability can be obtained.

[0047] [Laminated resin sheet] Figure 1 is a schematic perspective view showing the structure of a laminated resin sheet 1 according to one embodiment of the present invention. The laminated resin sheet 1 comprises a core layer 2 made of foamed resin, a skin layer 3 made of non-foamed resin laminated on one main surface of the core layer 2, and a skin layer 4 made of non-foamed resin laminated on the other main surface of the core layer 2.

[0048] The core layer 2 is made of foamed resin. The core layer 2 can be formed by physico-foaming or chemical foaming of molten resin material. The core layer 2 is preferably foamed using a physico-foaming agent such as nitrogen or carbon dioxide at a relatively low pressure, with nitrogen being more preferred. Examples of physico-foaming agents include inert gases such as nitrogen, carbon dioxide, air, and argon.

[0049] The resin constituting the core layer 2 is not particularly limited as long as it can bond well with the skin layers 3 and 4. While not limited to these, the resin constituting the core layer 2 can include, for example, engineering plastics and super engineering plastics, with polycarbonate being particularly preferred.

[0050] Skin layers 3 and 4 are made of non-foamed resin. In other words, skin layers 3 and 4 are not foamed.

[0051] Each of the skin layers 3 and 4 is a layer made of the resin molded body described above. That is, each of the skin layers 3 and 4 is a layer made of a resin molded body containing a first resin which is a thermoplastic resin, a second resin which is a low-melting-point liquid crystal polymer, and a copolymer of polycarbonate and polyester. Skin layer 3 and skin layer 4 may have the same composition or may have different compositions.

[0052] The laminated resin sheet 1 may be manufactured by integrally molding the core layer 2, skin layers 3 and 4, for example, by co-extrusion molding. Alternatively, the laminated resin sheet 1 may be manufactured by separately molding the core layer 2, skin layers 3 and 4, and then fixing them together by adhesive or welding.

[0053] [Method for manufacturing laminated resin sheets] The following describes an example of manufacturing a laminated resin sheet 1 by co-extrusion molding.

[0054] First, resin pellets, which will form the core layer 2, are fed into the screw cylinder of the main extruder. The resin pellets are heated in the screw cylinder to produce molten resin. Next, a foaming agent is injected into the molten resin from a foaming agent injection cylinder attached to the screw cylinder of the main extruder. The foaming agent is dissolved in the molten resin by the aforementioned screw cylinder, mixed, and uniformly dispersed. In this way, a mixed molten resin is produced. The mixed molten resin is discharged from the die outlet to form the core layer 2.

[0055] Simultaneously, the materials for skin layers 3 and 4 (first resin, second resin (low-melting point liquid crystal polymer), copolymer of polycarbonate and polyester, etc.) are introduced into the screw cylinders of the two auxiliary extruders, heated, and melted to produce two molten resins. One of the two molten resins is discharged from the die outlet to form skin layer 3, and the other is discharged from the die outlet to form skin layer 4.

[0056] The mixed molten resin and the two molten resins flow into dies from their respective extruders, merge within the dies, and are extruded from the die outlet so that the skin layer 3 is laminated to one main surface of the core layer 2 and the skin layer 4 is laminated to the other main surface of the core layer 2. The mixed molten resin foams as it is extruded into the atmosphere from the die outlet. The laminated resin sheet 1 thus extruded is cooled and then transported to a cutting machine by a take-up machine. The cutting machine cuts the laminated resin sheet 1 into the desired shape. In this way, the laminated resin sheet 1 is manufactured. The foaming method is a physical foaming method using inert gases such as nitrogen and carbon dioxide as foaming agents.

[0057] When extruded from the die, the second resin (low-melting point liquid crystal polymer) contained in each of the mixed resins forming skin layers 3 and 4 is extruded from the die exit in a molten state together with the first resin, making it easier to stretch along the extrusion direction. As a result, fibrous low-melting point liquid crystal polymer can be formed inside the laminated resin sheet 1, improving the flexural modulus of the laminated resin sheet 1.

[0058] Low-melting-point liquid crystal polymers are particularly prone to fiberization in skin layer 3 or 4. That is, in the manufacturing method described above, the two molten resins are more susceptible to the shear stress generated between them and the inner wall of the die near the die exit than the mixed molten resin located between the two molten resins. Furthermore, since skin layers 3 and 4 are made of non-foaming resin, they are less affected by bubbles than core layer 2, where bubbles are formed. Therefore, the low-melting-point liquid crystal polymers contained in skin layers 3 and 4 are more likely to form into fibers that extend in the extrusion direction.

[0059] [Effects of the laminated resin sheet according to this embodiment] The laminated resin sheet 1 according to one embodiment of the present invention has been described above. The laminated resin sheet 1 comprises a core layer 2 made of foamed resin. Therefore, the amount of resin used can be reduced compared to a molded body in which the entire molded body is made of a non-foamed molded body.

[0060] As a result, laminated resin sheet 1 can contribute to improving resource utilization, reducing transportation burden, reducing energy consumption, and reducing CO2 emissions. By providing laminated resin sheets to society, it is possible to contribute to achieving four of the 17 Sustainable Development Goals (SDGs) established by the United Nations: Goal 7 (Affordable and Clean Energy), Goal 9 (Industry, Innovation and Infrastructure), Goal 11 (Sustainable Cities and Communities), and Goal 12 (Responsible Consumption and Production).

[0061] The laminated resin sheet 1 further comprises skin layers 3 and 4 laminated on the main surface of the core layer 2. Each of the skin layers 3 and 4 is a layer made of the resin molded body described above, namely a resin molded body containing a first resin which is a thermoplastic resin, a second resin which is a low-melting-point liquid crystal polymer, and a copolymer of polycarbonate and polyester. As described above, this resin molded body has excellent strength and moldability. Therefore, according to this embodiment, a laminated resin sheet with high strength and excellent processability can be obtained.

[0062] In the above description, a skin layer 3 is laminated on one main surface of the core layer 2 and a skin layer 4 is laminated on the other main surface of the core layer 2. However, the laminated resin sheet may have a skin layer formed only on one main surface of the core layer. [Examples]

[0063] The present invention will be described more specifically below with reference to examples. The present invention is not limited to these examples.

[0064] [Solid Sheet] A non-foamed resin molded sheet (solid sheet) was produced by kneading polycarbonate (PC) and liquid crystal polymer (LCP) using an extruder. The thickness of the solid sheet was 1.5 mm. Teijin Limited's Panlite® L1225L polycarbonate was used. Ueno Pharmaceutical Co., Ltd.'s low-melting-point LCP, A-8100 (melting point approximately 230°C), was used as the liquid crystal polymer. The molding temperature was 260-300°C.

[0065] As a compatibilizer, a copolymer of polycarbonate and polyester was prepared and used. For comparison, an alloy (a compound, not a copolymer) of polycarbonate and polyester was also prepared and used as a compatibilizer.

[0066] [Laminated resin sheet] A laminated resin sheet was fabricated by co-extrusion molding, comprising a core layer made of foamed resin and a skin layer made of non-foamed resin laminated on both main surfaces of the core layer. The total thickness of the laminated resin sheet was 3.0 mm. The core layer (foamed layer) was made of 100% polycarbonate, and the skin layer (non-foamed layer) was made of a resin molded product containing PC, LCP, and a copolymer of polycarbonate and polyester.

[0067] The flexural modulus and yield stress of the fabricated solid sheets and laminated resin sheets were measured. The results are shown in Tables 1 and 2. Note that the compositions of laminated resin sheets No. 6 and No. 10 in Table 2 are the compositions of the skin layer (non-foamed layer).

[0068] [Table 1]

[0069] [Table 2]

[0070] Solid sheet No. 1 (Table 1), which used a copolymer of polycarbonate and polyester as a compatibilizer, showed significantly improved flexural modulus and yield stress compared to solid sheet No. 7 (Table 2), which did not use a compatibilizer. On the other hand, solid sheet No. 8 (Table 2), which used an alloy of polycarbonate and polyester as a compatibilizer, did not show a significant difference in flexural modulus and yield stress compared to solid sheet No. 7.

[0071] Solid sheet No. 2 (Table 1) is a modified version of solid sheet No. 1, with changes to the copolymer composition of the compatibilizer. Solid sheet No. 2 also exhibited superior flexural modulus and yield stress compared to solid sheets No. 7 and No. 8.

[0072] Solid sheet No. 3 (Table 1) is a modified version of solid sheet No. 1, with changes to the copolymer composition of the compatibilizer and an increased compatibilizer content. The increased compatibilizer content further improved the flexural modulus and yield stress.

[0073] Solid sheet No. 4 (Table 1) is a modified version of solid sheet No. 1 with a reduced LCP ratio. Compared to solid sheet No. 1, solid sheet No. 4 exhibited lower flexural modulus and yield stress due to the reduced LCP ratio. However, compared to solid sheet No. 9 (Table 2), which had the same PC-to-LCP ratio but no compatibilizer added, solid sheet No. 4 showed a significant improvement in both flexural modulus and yield stress. This indicates that, regardless of the PC-to-LCP ratio, using a polycarbonate-polyester copolymer as a compatibilizer can improve both flexural modulus and yield stress.

[0074] Solid sheet No. 5 (Table 1) is a solid sheet No. 1 with a higher proportion of LCP. The increased LCP proportion in solid sheet No. 5 further improved the flexural modulus and yield strength. This indicates that increasing the LCP proportion is advantageous from a strength standpoint. However, increasing the LCP proportion too much reduces moldability. Therefore, a PC to LCP ratio of approximately 90:10 to 99:1 is considered preferable.

[0075] Examples of laminated resin sheets No. 6 (Table 2) and No. 10 (Table 2) are laminated resin sheets in which layers made of resin containing PC and LCP as skin layers are formed. Laminated resin sheet No. 6, which used a copolymer of polycarbonate and polyester as a compatibilizer, showed significantly improved flexural modulus and yield stress compared to laminated resin sheet No. 10, which did not use a compatibilizer.

[0076] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the invention.

Claims

1. A first resin, which is a thermoplastic resin, The second resin is a liquid crystal polymer, It contains a copolymer of polycarbonate and polyester, A resin molded article wherein the melting point of the second resin is below the temperature at which the melt viscosity of the first resin becomes 4000 Pa·s. However, the melt viscosity is 150 sec. －１ The value measured at the shear rate is to be used.

2. The resin molded article according to claim 1, wherein the first resin is polycarbonate.

3. The resin molded article according to claim 2, wherein the melting point of the second resin is 260°C or lower.

4. A resin molded article according to any one of claims 1 to 3, wherein the mass ratio of the first resin to the second resin is such that the mass of the first resin : the mass of the second resin = 90:10 to 99:

1.

5. The resin molded article according to any one of claims 1 to 3, wherein the amount of the copolymer is 0.5 to 15 wt% of the total resin molded article.

6. The resin molded article according to any one of claims 1 to 3, wherein the polyester is polybutylene succinate or polybutylene terephthalate.

7. It has a sheet-like shape, A resin molded article according to any one of claims 1 to 3, having a thickness of 1.0 to 4.0 mm.

8. The flexural modulus is 2200 MPa or higher. A resin molded article according to any one of claims 1 to 3, wherein the yield strength is 100 MPa or more.

9. A core layer made of foamed resin, It comprises a non-foaming resin and a skin layer laminated on the main surface of the core layer, The skin layer is a layer made of a resin molded article according to any one of claims 1 to 3, wherein the laminated resin sheet.

10. The flexural modulus is 1500 MPa or higher. The laminated resin sheet according to claim 9, wherein the yield strength is 60 MPa or more.

Images