JP4538207B2 - Sealed container and manufacturing method thereof - Google Patents

Description

  The present invention relates to a sealed container and a manufacturing method thereof, and more particularly to a sealed container including a shape-retaining lid manufactured using a cold-molding resin sheet and a manufacturing method thereof.

  Conventionally, as a container for food such as beverage containers, yogurt containers, potion containers, cup noodles, and synthetic resin containers filled with disposable medical supplies, tensile strength, heat resistance, light resistance, moldability, High-impact polystyrene (HIPS) with improved brittleness by blending so-called general-purpose polystyrene resins (GPPS; General Purpose Polystyrene) such as styrene homopolymer with excellent surface gloss and rubbers such as SBR and BR into GPPS ; High Impact Polystyrene) is widely used. As a lid material for pasting and sealing such an opening of a polystyrene-based resin container, an aluminum laminate having an aluminum foil as a base material and a sealant layer for adhesion to the container on the surface is used. ing. A small piece of aluminum lid material punched out from such an aluminum laminate into a flattened shape of the lid is formed into a shape with a folded back end and a skirt, and the aluminum lid sealed at the opening of the container is sealed. It has excellent peelability, has peel resistance, is excellent in stability at the time of peeling, and is commonly used because it is less likely to adhere due to static electricity when supplied to the opening of the container and has good sheet supply. In addition, the aluminum lid has a property of maintaining a shape that is bent and deformed when a skirt formed by bending the peripheral edge portion is provided, so-called shape retention. For this reason, when drinking a filled beverage directly from the container, the state where the portion in contact with the mouth in the vicinity of the opening of the container is covered with the end of the lid is maintained, and the vicinity of the opening of the container is prevented from becoming dirty. It is suitable for use because it is hygienic and excellent in appearance.

  However, recently, there are many accidents in which foreign substances are mixed in processed food containers, and safety measures are an issue, but metal detectors cannot be used in containers using such aluminum lids. , Nails, staples, broken pieces of molded parts, bolts, nuts, wires, springs, and other metals that may be mixed cannot be detected. In addition, these containers having an aluminum lid have the disadvantage that the aluminum lid and the container body made of synthetic resin such as polystyrene need to be separately collected and are inferior in recyclability.

  As an alternative to such a conventional aluminum lid, a lid made entirely of plastic has been proposed. For example, a laminated base in which a heat-resistant film is laminated on both sides of a base material of a coextruded film in which a central layer made of high-density polyethylene and a polypropylene-based polymer and a coating layer made of high-density polyethylene are provided on both sides of the central layer. A lid material obtained by punching a laminated material having a sealant layer on the lower surface of a material into a predetermined shape has been proposed (see Patent Document 1). However, these plastic lids are bonded to the end of the container, and the outer peripheral part of the bonding surface is not folded back, but is extended from the bonding surface as it is, so that the beverage filled in the container is directly removed from the container. When drinking, it is a sanitary problem. Further, when the container is made of a polystyrene resin such as GPPS or HIPS, the material of the lid and the container body is different, and it is necessary to separate the lid and the container when discarding.

  On the other hand, in such a device for filling a container with a liquid such as a beverage, when trouble occurs in the molding and filling sealing process line, the container lid is heated by molding the molding resin sheet. There is an inconvenience that all of the molding resin sheets accumulated in the zone must be discarded. In order to avoid such a heating state, a means for retracting the heating device is separately required. Further, when the apparatus is driven, it takes time to raise the temperature to a certain temperature, and loss of the container material sheet and time is inevitable.

  In the production of an aluminum lid, the aluminum foil material is formed by sandwiching between male and female molds at room temperature without heating, so-called cold molding, and the molded aluminum lid retains its deformation. However, in the case of a plastic lid, when a stress is applied, the shape change of the molecule is strongly governed by the thermodynamic behavior, so the shape tends to recover in press molding at a temperature below the glass transition temperature. Is strong. For this reason, at the time of mold release immediately after molding processing, elastic recovery is not achieved and molding accuracy cannot be obtained, and in combination with changes over time after processing, depending on cold molding below the glass transition point, the mold shape However, a plastic lid having a shape-retaining property that maintains the state in which the end is bent faithfully is not obtained. In addition, attempts have been made to use a thick sheet or a hard material as a lid material in order to obtain the shape retention of the lid by cold forming, but a lid having satisfactory shape retention cannot be obtained. In addition, there is an inconvenience that the peelability of the upper lid is deteriorated.

  In addition, a resin film key top plate is proposed in which physical plastic deformation processing or physical decompression processing applied to a part or all of the base portion is performed by a punching and pressing operation using a sword-shaped jig (see Patent Document 2). In addition, a plastically deformed product obtained by applying a stress to a rubber or resin material preliminarily formed by extrusion molding in a sheet shape and applying plastic deformation is proposed (see Patent Document 3), and is formed from a strip-shaped metal plate. Forming the insert, forming the coated strip by coextrusion and coating with rubber or resin using the insert as a core material, and forming the weather strip by plastic deformation of the coated strip into a predetermined shape A method of manufacturing a weather strip including a plastic deformation step is proposed (see Patent Document 4). However, in the invention described in Patent Document 2, the plastic deformation of the resin film is performed by heating the tip of the sword-shaped jig to a temperature not lower than the glass transition point and not higher than the softening point of the resin film. In the invention described in No. 3, it is necessary to heat the rubber or the resin material. In the invention described in Patent Document 4, the metal body is a plastic deformation of the core material, which is described in these publications. The invention does not relate to a processed product obtained by so-called cold forming of only a resin sheet containing no metal and a method for producing the processed product.

On the other hand, in HIPS, impact resistance increases as the content of rubber blended in polystyrene increases, but tensile strength, heat resistance, light resistance, moldability, surface glossiness, transparency, etc. are reduced. Generally, rubber having a rubber content of 5 to 20% by weight is known. As a method of compounding rubber with polystyrene, a method of polymerizing styrene monomer by dissolving rubber in styrene monomer, or a method of mechanically blending rubber and polystyrene, that is, polymers, or mixing both in latex form. However, according to the former polymerization method, a graft copolymer having a polystyrene side chain on a rubber is obtained, and the impact resistance is remarkably improved, so that it is frequently used. For example, (a) 5 to 97% by weight of a styrene polymer having a syndiotactic structure, (b) 97% to 10% by weight of a rubber-like elastic body containing a styrene component, and a styrene polymer 3 having a syndiotactic structure An impact-resistant polystyrene-based resin composition comprising 3-90% by weight of a blend with -90% by weight and (c) 0-10% by weight of a rubber-like elastic body having a styrene component and a polar group is proposed, An impact-resistant polystyrene-based resin composition having improved impact resistance and elongation while maintaining the properties such as heat resistance, chemical resistance, and mechanical strength inherent in syndiotactic polystyrene has been proposed. (See Patent Document 5).
Japanese Patent Laid-Open No. 11-10810 JP 2001-76581 A JP 2000-135744 A JP-A-5-237904 JP-A-9-100377

  An object of the present invention is to produce a polystyrene-based resin sheet capable of producing a processed product having shape retention by cold forming, in particular, using a cold-forming resin sheet such as an impact-resistant polystyrene-based resin sheet. Another object of the present invention is to provide a sealed container having a lid and a manufacturing method thereof.

  The basic concept of the present inventors is that it can be applied to a conventional filling machine using an aluminum lid that does not include a lid thermoforming device, that is, a cold-formed product of a resin sheet. It has shape retention and impact resistance, is superior in terms of hygiene and appearance, prevents leakage of fillers, makes it possible to use a metal detector for inspection of metallic foreign objects, and the same material as the container It is made of polystyrene resin, which eliminates the need for separation treatment with polystyrene containers and improves recyclability, has excellent peelability when opening the lid, and can prevent deterioration and deterioration of the filling in the container Started development of a lid made of metal. When such a resin container is used, not only can the filling machine be prevented from becoming large, complicated, and slow, but also a filling machine that does not have a conventional thermoforming device can be used as it is. Therefore, as a material for the lid, a polystyrene resin is selected as in the case of the polystyrene container, and the resin sheet material that can be made into a lid with excellent shape retention by cold forming, in particular, high impact polystyrene (HIPS). Researched, when a resin sheet was prepared from a resin composition in which a predetermined impact-resistant polystyrene and a predetermined styrene-butadiene copolymer were mixed at a predetermined ratio, and a lid was prepared from the resin sheet by cold molding, It has been found that the lid is excellent in shape retention and can be put to practical use, and the present invention has been completed.

That is, the present invention provides: (1) a sealed container comprising a resin container and a lid fixed to the resin container, and the lid having shape-retaining properties cold- forms the cold-molding resin sheet. The produced resin sheet is a resin sheet comprising a base material layer containing a polystyrene resin or a base material layer containing a polystyrene resin, and the polystyrene resin is impact resistant. polystyrene (HIPS; High impact polystyrene) and styrene - sealing the container, characterized by containing a butadiene copolymer comprising the composition and, (2) high impact polystyrene, the presence of the rubber-like polymer The weight average molecular weight of the matrix is 150,000 to 300,000, the styrene content is 82 to 94% by weight, the rubber content is 6 to 15% by weight, and the liquid paraffin amount is 0. 3.0 sealed containers or as described in (1) above, which is a high-impact polystyrene (A) in weight percent, (3) high-impact polystyrene (A) is 30 or less swelling and sealing containers or (2) above, wherein it has a soft component particles having a mean particle size in the range of 0.5 to 10 [mu] m, (4) a styrene - butadiene copolymer, styrene content sealed containers or according to any one of the above (1) to (3), which is a butadiene copolymer (B), - 30 to 90 wt%, a styrene-butadiene content of 10 to 70 wt% (5) The above-mentioned (1) to (4) comprising a composition comprising 100 to 70% by weight of impact-resistant polystyrene (A) and 0 to 30% by weight of a styrene-butadiene copolymer (B). ) about the sealing container according to any of.

Moreover, this invention is (6) The said (1) characterized by the resin sheet | seat for cold forming having a functional layer laminated | stacked 1 or 2 layers or more on both surfaces or one side of a base material layer. ~ or sealed container according to any one of (5), (7) for cold forming resin sheet, above (1) and having a sealant layer as the functional layer ~ according to any one of (6) sealed container and, (8) a sealant layer, a sealed container and above (7), wherein the containing thermoplastic elastomer and / or ethylene copolymer, (9) cold forming resin sheet, sealed containers or according to any one of the above and having an antistatic layer as the functional layer (1) to (8), (10) for cold forming resin sheet, printing layer as the functional layer and having a seal according to any one of the above (1) to (9) Vessels and, (11) cold molding resin sheet, the functional layer (1) and having a barrier layer as-sealed containers or according to any one of (10), (12) cold forming use resin sheet, sealed containers or according to any one of the above and having a reinforcement layer as the functional layer (1) to (11), (13) reinforcement layer, sealant layer and the substrate layer that provided above (12) according sealed container and characterized by between, (14) reinforcement layer, the (13), characterized by containing a polyolefin-based resin sealed according containers and, (15) a polyolefin resin, LLDPE sealed containers or (14) above, wherein it is a (linear low density polyethylene), the resin sheet for molding inter (16) cold, Features a wear-resistant layer on the surface as a functional layer Sealed containers or according to any one of the above (1) to (15) to (17) above the wear layer, characterized in that a layer containing a polyolefin resin and / or nylon resin (16 ) sealed containers and described, (18) a polyolefin resin, CPP (sealed container and above (17), wherein it is a non-oriented polypropylene), a resin sheet for molding inter (19) cold , sealed containers or according to any one of the above (1) to which is characterized by having a functional layer containing a base layer of the same kind as the resin (18), (20) a base layer and the same kind of resin, general purpose polystyrene (GPPS; general Purpose polystyrene) and / or styrene - butadiene copolymer described above which is characterized by having a functional layer containing the polymer (19) sealed containers and described, (21) cold molding resin The sheet has a surface intrinsic resistance Value sealed containers or according to any one of the above (1) to (20) characterized by having at least one surface is in the range of ^{10 6 ~10 14 Ω, (22} ) a resin sheet for cold forming but sealed containers or of any one of at least one of said characterized by having a surface (1) to the surface static friction coefficient is in the range of 0.1 to 0.4 (21), (23) cold during molding resin sheet, sealed containers or according to any one of the above is characterized in that the white colored (1) to (22), the resin sheet for molding inter (24) cold, thick 50μm~1mm sealed containers or according to any one of the above (1) to (23), which is a by, (25) peel strength between the resin container and lid, 2～30N in 180 ° peel test / wherein any one of the above (1) to (24), which is a 15mm wide Sealed container and, (26) the adhesive strength between the substrate layer and the sealant layer or the reinforcement layer is, about the sealed container of the above (25), wherein a is 3N / 15 mm width or more.

Further, the present invention provides (27) a cold-molding resin sheet at a temperature lower than the glass transition point of the resin constituting the resin sheet to produce a lid having shape retention, A method for producing a sealed container for fixing a resin container , wherein the resin sheet is a resin sheet comprising a base material layer containing a polystyrene resin or a base material layer containing a polystyrene resin on which a functional layer is laminated. there are, the polystyrene resin is high impact polystyrene (HIPS; High impact polystyrene) and styrene - producing how the sealed container, characterized in that it contains butadiene copolymer comprising the composition) and, ( 28) cold molding, indentation in the male mold a resin sheet for cold forming against the female mold, it and the manufacturing how the sealed container (27) above, wherein done by pressing, (29) Mold and the female mold of the clearance with respect to the thickness of the resin sheet for cold forming, manufacturing side of the sealed container above (28) wherein it has been adjusted to 1.3 to 4.0 times law and, (30) is secured between the resin container and the lid, and manufacturing how the sealed container according to any one of the above (27) to (29), characterized in that by ultrasonic welding method, (31) resistance Impact polystyrene is obtained by polymerizing a styrene monomer in the presence of a rubbery polymer, the matrix has a weight average molecular weight of 150,000 to 300,000, a styrene content of 82 to 94% by weight, and a rubber content of The production of a sealed container according to any one of (27) to (30) above, which is an impact-resistant polystyrene (A) having 6 to 15% by weight and a liquid paraffin amount of 0 to 3.0% by weight. mETHODS and, the (32) high-impact polystyrene (A), 30 It and manufacturing how the sealed container above (31) wherein with a soft component particles having a mean particle size in the range of less swelling and 0.5 to 10 [mu] m, (33) a styrene - butadiene copolymer Any of (27) to (32) above , wherein the polymer is a styrene-butadiene copolymer (B) having a styrene content of 30 to 90% by weight and a butadiene content of 10 to 70% by weight. and manufacturing how the sealed container according, (34) high-impact polystyrene (a) 100 to 70% by weight of styrene - by containing a butadiene copolymer (B) a composition consisting of 0 to 30 wt% and manufacturing how the sealed container according to any one of the above (27) - (33), wherein, (35) a resin sheet for cold forming is on both sides or one side of the base layer, one or two layers Having functional layers stacked above And manufacturing how the sealed container according to any one of above, characterized in Rukoto (27) to (34), the resin sheet for molding inter (36) cold, and having a sealant layer as the functional layer above (27) - and manufacturing how the sealed container according to any one of (35), above, characterized in that it contains (37) a sealant layer, a thermoplastic elastomer and / or ethylene copolymer (36 ) and manufacturing how the sealed container, wherein (38) the resin sheet for cold forming is a sealed container according to any one of the above which is characterized by having an antistatic layer as the functional layer (27) - (37) of and manufacturing how, (39) for cold forming resin sheet, having a print layer and manufacturing how the sealed container according to any one of the above (27) to (38), wherein the functional layer, (40) the resin sheet for cold forming, machine And manufacturing how the sealed container according to any one of the above (27) - (39), characterized in that it has a barrier layer as a layer (41) for cold forming resin sheet, reinforcement layer as the functional layer and manufacturing how the sealed container according to any one of the above (27) - (40), characterized in that it comprises, (42) the reinforcement layer is provided between the sealant layer and the substrate layer and manufacturing how the sealed container above (41) wherein, (43) reinforcement layer, the (42), characterized by containing a polyolefin resin Ya producing how the sealed container according , (44) a polyolefin resin, LLDPE and manufacturing how the sealed container above (43), wherein it is a (linear low density polyethylene), the resin sheet for molding inter (45) cold, Has a wear-resistant layer on the surface as a functional layer And manufacturing how the sealed container according to any one of above, characterized in Rukoto (27) - (44), (46) the wear-resistant layer is a layer containing a polyolefin resin and / or nylon resin and manufacturing how the sealed container above (45) wherein, (47) a polyolefin resin, the (46) cold-formed processed product, wherein it is a CPP (cast polypropylene) of and manufacturing how, (48) a resin sheet for cold forming is sealed according to any one of the above which is characterized by having a functional layer containing a base layer of the same kind as the resin (27) - (47) characterized by having a functional layer containing a butadiene copolymer -; (general Purpose polystyrene GPPS) and / or styrene container and manufacturing how, (49) a base layer and the same kind of resin, generally polystyrene Above (48) And manufacturing how the sealed container, wherein (50) the resin sheet for cold forming is, the surface resistivity and having at least one surface is in the range of 10 ⁶ ~10 ¹³ Ω (27 ) - and manufacturing how the sealed container according to any one of (49), (51) a resin sheet for cold forming is a surface static friction coefficient of at least one of the surfaces it is in the range of 0.1 to 0.4 it and manufacturing how the sealed container according to any one of the above (27) - (50), characterized in, (52) a resin sheet for cold forming is, above, characterized in that the white colored (27) ~ and manufacturing how the sealed container according to any one of (51), (53) for cold forming resin sheet, above, characterized in that the thickness of 50μm~1mm (27) - (52) and manufacturing how the sealed container according to any one, (54) and the resin container and the lid Peel strength between the can, and manufacturing how the sealed container according to any one of the above (27) - (53), which is a 6~20N / 15mm width at 180 ° peel test, (55) group adhesion strength between the wood layer and the sealant layer or the reinforcement layer is, relates to the production how the sealed container above (54), wherein a is 3N / 15 mm width or more.

  According to the sealed container of the present invention and the method for manufacturing the same, a heating device is not required in forming the lid, so that the device can be miniaturized and high-speed continuous forming is possible. In particular, when produced using an impact-resistant polystyrene-based resin sheet, a cold-formed product having excellent impact resistance and shape retention can be obtained. By using the sealed container of the present invention, inspection by a metal detector can be performed, so that foreign matter contamination can be detected in advance, and can be collected and processed without separating the lid and the resin container. Even when trouble occurs in the filling device of the filling material to be filled in, there is no softening of the molding resin sheet of the lid supplied to the processing area, and the disposal of the resin sheet can be avoided, Further, the lid can be peeled off from the resin container with a finger, and peeling does not occur due to natural fall.

  The sealed container of the present invention is a sealed container comprising a resin container and a lid fixed to the resin container, and the lid is produced by cold-molding a cold-molding resin sheet and has shape retention. If it has, it will not specifically limit.

  In the present invention, cold forming refers to forming performed in a temperature atmosphere less than the glass transition point (Tg) of the resin. Such cold forming can be performed by using a cold forming machine used for forming aluminum foil or the like by pressing the sheet material into the female mold with a male mold and pressing the sheet material at a high speed. According to the inter-forming, plastic deformation such as molding, bending, shearing and drawing can be generated without heating.

  The plastic deformation refers to deformation that occurs when the elastic limit is exceeded. When the material is subjected to stress above the yield point, the deformation becomes significant. For example, in the case of a polystyrene resin, the glass transition point (Tg ), Usually at a temperature of 10 to 60 ° C., preferably at room temperature or normal temperature, when plastic deformation is performed, the sheet is whitened. To confirm whether plastic deformation has occurred, Whether or not whitening has occurred can be visually determined. In addition, the glass transition point (Tg) of each resin is as shown in Table 1.

本発明の密封容器の蓋は、後述の樹脂容器に固着し、保形性を有するものである。ここで保形性を有するとは、上述のように、折り曲げられて塑性変形された形態を維持する性質を有することをいい、密封容器の蓋が保形性を有するものであれば、その形状・形態は特に制限されない。例えば、ポリスチレン製の樹脂容器の蓋として、ポリスチレン系樹脂シートを用いて冷間成形により作製した蓋の場合、天面Ｔに対して垂直（α＝９０°）に形成されたスカート部分Ｓが、天面Ｔに対してα＝１３０°を保持することができる（図６）場合を好適に例示することができる。

The lid of the sealed container of the present invention is fixed to a resin container to be described later and has shape retention. Here, having shape-retaining property means having the property of maintaining a shape that is bent and plastically deformed as described above. If the lid of the sealed container has shape-retaining property, its shape -The form is not particularly limited. For example, as a lid of a polystyrene resin container, in the case of a lid made by cold molding using a polystyrene resin sheet, a skirt portion S formed perpendicular to the top surface T (α = 90 °) A case where α = 130 ° can be held with respect to the top surface T (FIG. 6) can be preferably exemplified.

  The lid of the sealed container of the present invention is not limited to any material, shape, form, etc., and any material may be used, but the one containing the same kind of resin as the resin container as a main component, Preferred from the viewpoint of recyclability, for example, PS (polystyrene) resin, AS (styrene-acrylonitrile copolymer) resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, AXS (terpolymer having acrylonitrile and styrene component) ) PS resins such as resins, PET resins such as unsaturated polyester resins and saturated polyester resins, high density polyethylene, low density polyethylene, EVA (ethylene-vinyl acetate copolymer) resin, EVOH (ethylene-vinyl alcohol) Copolymer) polyethylene resin such as resin, polypropylene resin, Other polyolefin resins, polyacetal resins, polycarbonate resins and the like can be exemplified, and one or more of these may be contained, and among these, Those containing PS resin, ABS resin, and PET resin are preferred. Furthermore, it is preferable that both the lid and the resin container contain a polystyrene resin as a main component because of excellent tensile strength, heat resistance, light resistance, moldability, and surface gloss. In addition, additives such as plasticizers, stabilizers, flame retardants, antioxidants, ultraviolet absorbers, colorants, antistatic agents, and auxiliary materials such as reinforcing agents and fillers are added to these resins as appropriate. It may be done.

  The shape and form of the lid of the sealed container of the present invention is not particularly limited, but a skirt is formed which is fixed to the opening of the resin container and the periphery of the resin container is folded to cover the periphery of the opening of the container. The shape is kept as it is, which is preferable in terms of hygiene and appearance.

  The resin container of the sealed container of the present invention is not limited by any material, shape or form. Although what kind of material may be sufficient as the material of a resin container, the same kind of resin as a lid | cover is preferable and resin similar to the above-mentioned lid | cover can be illustrated concretely. Moreover, the additive illustrated as a material of a lid | cover and submaterial may be added to these resin suitably. The shape and form of the resin container containing such resin may be any shape, and the molding method is compression molding, transfer molding, laminate molding, injection molding, extrusion molding, blow molding, calendaring, casting Any method may be used. Specific examples of such a resin container include a liquid filling container, a beverage filling container, and a food filling container. In particular, beverage containers such as lactic acid bacteria beverage containers, and food containers such as dairy products containers do not require a heating process in the liquid filling device, and when the device is downsized and trouble occurs, This is preferable because it is not necessary to discard the resin sheet of the lid material.

  The resin sheet for cold forming used for producing the lid of the sealed container of the present invention is composed of a base material layer (single layer) or a base material layer (laminated body) in which functional layers are laminated, etc. Any of them may be a single layer structure composed of only a base material layer, or a laminated structure in which functional layers are laminated on one or both surfaces of the base material layer. Good. Examples of the functional layer include a sealant layer having an adhesive function, an antistatic layer having an antistatic function, a barrier layer having a gas permeation blocking function, a printing layer having a display function, a protective layer having a printing layer protection function, and an edge break. Examples thereof include a strength reinforcing layer having a prevention function and a wear-resistant layer having a damage prevention function.

  The base layer of the cold-forming resin sheet is a layer having cold formability that makes it possible to form a secondary processed product having shape retention by plastic deformation by cold forming of the sheet. The material of the base material layer is not particularly limited. For example, PS (polystyrene) resin, AS (styrene-acrylonitrile copolymer) resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, AXS (Terpolymers having acrylonitrile and styrene components) PS resins such as resins, PET resins such as unsaturated polyester resins and saturated polyester resins, high density polyethylene, low density polyethylene, EVA (ethylene-vinyl acetate copolymer) ) Polyethylene resins such as resin, EVOH (ethylene-vinyl alcohol copolymer) resin, and poly Propylene-based resin, and other polyolefin resins, and polyacetal resin, can be exemplified those containing polycarbonate resin, it may be one containing one or more of these. Among these, those containing PS resin, ABS resin, and PET resin are preferable, but containing a resin of the same type as the resin container as a main component is particularly preferable because recyclability can be improved. When the resin container is mainly composed of a polystyrene-based resin, in particular, an impact-resistant polystyrene-based resin, it is more preferable to contain the same kind of polystyrene-based resin or impact-resistant polystyrene-based resin as a main component. In addition, these resins include additives such as plasticizers, stabilizers, flame retardants, antioxidants, ultraviolet absorbers, colorants, antistatic agents, and auxiliary materials such as reinforcing agents and fillers (added) Agent) may be added.

  Examples of the polystyrene resin contained in the base layer of the cold forming resin sheet include so-called general-purpose polystyrene resins, rubber-modified polystyrene resins, and mixtures thereof. Among these, A rubber-modified polystyrene resin is preferable, and among the rubber-modified polystyrene resins, an impact-resistant polystyrene resin is preferable, and in particular, a material obtained by mixing and kneading a styrene-butadiene copolymer in a predetermined ratio to an impact-resistant polystyrene resin. More preferred.

  The general-purpose polystyrene resin is also called GPPS (General Purpose Polystyrene) and is usually a styrene homopolymer, but the resin used for the base material layer is not limited to the styrene homopolymer. Examples of the styrene monomer of the general polystyrene resin include styrene having one or more substituents such as an alkyl group and a phenyl group in addition to styrene. Specific examples of the styrene monomer include α-methylstyrene, α-ethylstyrene, α-n-propylstyrene, α-isopropylstyrene, α-n-butylstyrene, α-t-butylstyrene, and o-methylstyrene. , M-methyl styrene, p-methyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene, o-isopropyl styrene, m-isopropyl styrene, p-isopropyl styrene, ot-butyl styrene, m- Examples thereof include alkyl-substituted styrenes such as t-butyl styrene and p-t-butyl styrene, and the polystyrene resin may be a homopolymer of these monomers or a copolymer of two or more. As copolymers, random copolymers, alternating copolymers, block copolymers, grafts The polymer or the like may be any one.

  The rubber-modified polystyrene resin may be any so-called impact-resistant polystyrene (HIPS: High Impact Polystyrene) in which synthetic rubber is blended with polystyrene. Polystyrene, that is, a method in which polymers are mechanically blended or both are mixed in a latex state, or a method in which rubber is dissolved in a styrene monomer and polymerized, may be used. A method of polymerizing a styrene monomer below is preferred. The high impact polystyrene obtained by the method of polymerizing a styrene monomer in the presence of such a rubbery polymer is a graft copolymer having a polystyrene side chain on a rubber, and the high impact polystyrene is a matrix. The soft component particles have a structure in which the soft component particles are dispersed in the polystyrene that forms the polymer, and the soft component particles have a structure in which polystyrene is occluded in a rubbery polymer generally called a salami structure or a single occlusion structure. However, it is not limited to these.

  Examples of the styrene monomer include styrene monomers similar to the above-mentioned GPPS. Examples of the rubbery polymer include polybutadiene, styrene-butadiene copolymer, polyisoprene, and the like. A styrene-butadiene copolymer is particularly preferred. Examples of such styrene-butadiene copolymers include SBR-based thermoplastic rubbers, and styrene-butadiene block copolymers having a SB or SBS structure, or SEBS in which these are completely or partially hydrogenated are also used. be able to.

  As the rubber-modified polystyrene resin contained in the base material layer, impact-resistant polystyrene alone or a composition comprising impact-resistant polystyrene and a styrene-butadiene copolymer, particularly, impact-resistant polystyrene of 100 to 70% by weight. And a styrene-butadiene copolymer in an amount of 0 to 30% by weight, in particular, obtained by polymerizing a styrene monomer in the presence of a rubbery polymer, and the weight average molecular weight of the matrix is 150,000 to 300,000. An impact polystyrene having a styrene content of 82 to 94% by weight, a rubber content of 6 to 15% by weight and a liquid paraffin content of 0 to 3.0% by weight (hereinafter referred to as “impact polystyrene (A)”). Styrene-butadiene copolymer having a styrene content of 30 to 90% by weight and a butadiene content of 70 to 10% by weight (hereinafter referred to as 100 to 70% by weight) A composition comprising a composition consisting of 0 to 30% by weight (referred to as “styrene-butadiene copolymer (B)”) enables plastic deformation by cold forming of the sheet, and is obtained by cold forming of the sheet. The lid of the sealed container, which is the next molded product, is particularly preferable because it has excellent impact resistance and shape retention.

  If the rubber content of the high impact polystyrene (A) is 6% by weight or more, preferably 9% by weight or more, the sheet does not break during cold forming, and if the rubber content is 15% by weight or less, Cold forming is preferable because the sheet is more easily plastically deformed and the lid of the sealed container obtained has sufficient shape retention. The amount of rubber of impact-resistant polystyrene is calibrated by the infrared absorption spectrum (IR) method using a method of calculating from the amount of rubber used at the time of production or using impact-resistant polystyrene containing a known amount of rubber as a standard sample. It can be determined by creating and evaluating a line.

  Further, when the content of liquid paraffin in the above impact-resistant polystyrene (A) is 3.0% by weight or less, preferably 2.0% by weight or less, the sheet is more easily plastically deformed by cold forming, and thus obtained. It is preferable because the lid of the sealed container has sufficient shape retention. Specific examples of such liquid paraffins include cycloparaffins such as cyclopentane, cyclohexane, and cycloheptane. White mineral oil (a mixture of alkyl naphthene hydrocarbons having an average weight molecular weight of 300) that can be used for food packaging materials. (Mineral oil of about ~ 600) can be preferably exemplified.

  Among the above impact-resistant polystyrenes (A), those having a weight average molecular weight in the range of 150,000 to 300,000, particularly 200,000 to 250,000 are preferable, and if the weight average molecular weight of the matrix is 150,000 or more, The lid of the sealed container obtained by hot forming becomes a molded product having more appropriate strength. If it is 300,000 or less, the sheet is more easily plastically deformed by cold forming, and the obtained lid has sufficient shape retention. It is preferable because it has properties.

  The molecular weight of the high-impact polystyrene matrix can be measured by the following method. That is, 1 g of impact-resistant polystyrene is dissolved in 30 ml of a methyl ethyl ketone / methanol mixed solvent (20/3 volume ratio). Next, the matrix portion and the soft component particles that are insoluble components are separated by centrifugation, and the supernatant liquid other than the insoluble components is taken out by decantation, and it is gradually added to about 500 ml of methanol with stirring to precipitate the polymer portion. . The polymer part was separated by filtration, methanol was removed by drying, and a solution obtained by dissolving the obtained dry sample in tetrahydrofuran so as to have a concentration of 2 mg / ml was used by gel permeation chromatography (GPC). Measure the molecular weight of the matrix. The GPC used is equipped with a differential refractometer (RI detector) as a detector, and the molecular weight can be calculated by a calibration curve obtained using commercially available monodisperse polystyrene.

  Moreover, among the said impact-resistant polystyrene (A), the thing whose swelling degree of the soft component particle contained is 30 or less is preferable. If the swelling degree of the soft component particles is 30 or less, the sheet is more easily plastically deformed by cold forming, and the lid of the sealed container obtained has sufficient shape retention.

  The degree of swelling can be measured by the following method. That is, 0.4 g of impact-resistant polystyrene is dissolved in 18 ml of toluene and left for 2 hours or longer. The obtained toluene solution is subjected to a centrifuge (4500 rpm × 2 hours) to separate insoluble components. The supernatant is discarded, the insoluble matter is weighed, and the weight is a. Next, the insoluble matter is dried with a vacuum dryer, and the weight after drying is defined as b. The degree of swelling can be determined by a / b.

  Further, among the above impact-resistant polystyrene (A), those having an average particle diameter of 0.5 to 10 μm, particularly 1 to 5 μm are preferable. If it is 0.5 μm or more, preferably 1 μm or more, the sheet will not break during cold forming of the sheet, and if it is 10 μm or less, preferably 5 μm or less, the sheet is more easily plastically deformed by cold forming. Thus, the obtained lid has sufficient shape retention.

  The average particle diameter of the soft component particles can be measured by the following method. That is, high-impact polystyrene is dissolved in methyl ethyl ketone so as to have a concentration of about 1%. This sample solution is irradiated with laser light using a laser diffraction particle size distribution measuring device (SALD1100, manufactured by Shimadzu Corporation), and images of the generated diffracted light and scattered light are detected, and the size of the particles is determined by the pattern and intensity of the image. Calculate thickness and quantity. The average particle size can be 50% in the cumulative volume distribution.

  On the other hand, among the styrene-butadiene copolymers (B), those having a styrene content of 30 to 90% by weight and a butadiene content of 10 to 70% by weight are more excellent in a lid that is cold-formed from a sheet. It is preferable in that it has shape retention and impact resistance.

  For the base material layer in such a resin sheet, various additives such as antioxidants, plasticizers, heat stabilizers, ultraviolet absorbers, light stabilizers, lubricants, mold release agents, flame retardants, flame retardants are optionally added. Additives such as auxiliaries, pigments, dyes, carbon black, and antistatic agents can be blended, and organic fine particles and inorganic fine particles can be added as long as the performance of the base material layer is not impaired. In addition, the thickness of the base material layer in the resin sheet is not particularly limited, for example, in the case of a polystyrene-based resin sheet for producing a lid that needs to be peeled between a resin container such as an open container, A range of 50 μm to 1 mm is preferable.

  The functional layer laminated on one or both sides of the base material layer in the cold-molding resin sheet used in the present invention is adhesive, antistatic, abrasion resistant, aesthetic, weather resistant, and gas barrier resistant. , Ultrasonic vibration resistance (when ultrasonic sealing, if there is a weak part of the molded product due to the vibration and pressure (surface damage, etc. that occurred during molding), the weak part will be damaged such as perforation or tearing. Resistance to breakage due to vibration), edge cut resistance (resistance to ultrasonic seal when the part abutting against the edge of the seal head is damaged by the vibration / pressure and easily cuts at the time of peeling), etc. For example, a sealant layer, an antistatic layer, a printing layer, a barrier layer, a strength reinforcing layer, and an abrasion resistant layer can be used. The functional layer may be composed of a multilayer having each function, or may be composed of a single layer having a plurality of functions. As a resin sheet having these functional layers, For example, a base material layer with a sealant layer laminated on one or both sides, a base material layer with a sealant layer and an antistatic layer laminated on each side, and a base material layer on one side with a sealant layer Is laminated with a printing layer and an antistatic layer sequentially on the other side, a sealant layer is laminated on one side of the base material layer, and a printing layer and an abrasion resistant layer are sequentially provided on the other side. Examples thereof include those in which a barrier layer is laminated between a sealant layer and a base material layer, and those in which a strength reinforcing layer is laminated between a sealant layer and a base material layer. These functional layers may contain additives such as antioxidants, heat stabilizers, UV absorbers, light stabilizers, flame retardants, mineral oils, and external additives as needed. Organic fine particles and inorganic fine particles can be added as long as the performance is not impaired.

  As a method for producing the functional layer such as the sealant layer or the antistatic layer, a coating liquid containing a component corresponding to each function, for example, an adhesive component or an antistatic agent, is applied to one or both sides of the base material layer and dried. And a method in which a film in which these components are kneaded with a resin material is prepared and laminated. As a coating method, a roll coater, a knife coater, a gravure knife coater, a spraying method or the like can be adopted. Even if the surface of the base material layer is modified in advance by a corona discharge treatment method, an ozone treatment method, a plasma treatment method, or the like. Good. Further, in the case of a functional film for laminating, from the viewpoint of recyclability, those containing the same type of resin as the base material layer are preferable. For example, when the base material layer contains the above-mentioned polystyrene resin, GPPS and / or styrene -The thing containing a butadiene copolymer is preferable.

  The sealant layer as the functional layer is laminated directly or indirectly on both sides or one side of the base material layer in order to adjust the fixing strength between the lid cold-formed from the resin sheet and the resin container. When it is necessary to adjust the fixing strength, such as when it is necessary to peel between the resin container and the lid with a finger, it is preferable to provide a sealant layer, but the resin container and the lid are made of the same kind of resin. In the case where it is not necessary to adjust the fixing strength, such as in the case of a molded product that is manufactured and preferably has a high fixing strength, it is not particularly necessary to provide it. The component and thickness of the sealant layer should be appropriately selected according to the components of the lid and the resin container fixed via the sealant layer and the fixing method (for example, physical thermal fusion, chemical bonding, etc.). Can do. Adhesive components in chemical adhesion include starch, glue, dextrin, vinyl acetate resin, vinyl chloride resin, vinyl polymer such as acrylic resin, natural rubber, rubber such as chloroprene rubber, butyl rubber, amino resin, epoxy resin, phenol Resin, unsaturated polyester, polyurethane, polyimide, etc. can be mentioned, but physical bonding with a sealant film for laminating that does not require adjustment of the fixing site rather than chemical bonding with a sealant layer formed by application of such an adhesive component Thermal fusion is preferred. In general, the thickness of the sealant layer is preferably in the range of 10 to 50 μm.

  In a resin sheet on which a sealant layer is laminated, when the sheet is wound and stored and transported in a roll shape, the sheets may adhere to each other or may be blocked. In order to prevent this, it is known that an adhesive layer having an adhesive function and a thermoplastic resin layer such as LDPE (low density polyethylene) which is difficult to adhere are melt-coextruded and laminated (Japanese Patent Laid-Open No. 6-1994). No. 31866). The sealant layer in the present invention includes a single layer adhesive layer having the above-mentioned adhesive function and a two-layered layer in which a thermoplastic resin layer that is difficult to adhere to the adhesive layer is included for convenience. However, for the sake of convenience, a single layer adhesive layer and a two-layered layer in which an adhesive layer and another thermoplastic resin layer that is difficult to adhere are laminated are included. In the present invention, a film in which the adhesive layer and a strength reinforcing layer described below are laminated by melt coextrusion is referred to as a reinforcing sealant film.

  For example, when the resin container containing a polystyrene resin as a main component and a lid are ultrasonically welded via the above-described laminate sealant film, the sealant layer contains the same type of resin as the base material layer as a main component. A sealant film can be suitably exemplified, and when another thermoplastic resin is mixed in the same type of polystyrene resin as the resin container or the base material layer, the peel strength can be adjusted by the amount of the mixture. Moreover, the sealant film which mainly has what is excellent in adhesiveness, such as a thermoplastic elastomer and an ethylene-type copolymer, can be illustrated suitably. Examples of the ethylene copolymer include an ethylene-vinyl acetate copolymer and an ethylene-unsaturated carboxylic acid ester copolymer. In the sealant layer, various additive components such as an antioxidant, a heat stabilizer, an ultraviolet absorber, a light stabilizer, a lubricant, a flame retardant, a flame retardant aid, an antistatic agent, a pigment, carbon black, Additives such as mineral oil and external lubricant can be blended. In addition, organic fine particles and inorganic fine particles can be added as long as the sealing function is not impaired.

The antistatic layer as the functional layer is provided to suppress frictional charging and enable continuous molding of the lid from the resin sheet. Such an antistatic layer is usually laminated directly or indirectly on the base material layer on the surface opposite to the lamination surface of the sealant layer. When a resin sheet provided with such a functional layer is subjected to continuous cold forming, the sheet and the mold are rubbed in the mold portion, and the lid of the molded product is remarkably charged. The lid from the mold adheres to the mold and does not release and overlaps with the next sheet to be supplied, electrification adheres to the periphery of the mold and the star, and the lid immediately after molding flies in the air. It is possible to prevent the unloading / feeding of the sheet from being difficult and impossible to transport. Such charging of the molded product can be prevented by improving the conductivity of the sheet surface and / or improving the slipperiness of the sheet surface. As an improvement in conductivity, the surface specific resistance value of the resin sheet surface measured in accordance with JIS-K6911 is preferably 10 ⁶ to 10 ¹⁴ Ω. It is preferable that the static friction coefficient of the resin sheet surface measured in conformity with 0.1 to 0.4.

In order to set the surface resistivity of the resin sheet surface to 10 ⁶ to 10 ¹⁴ Ω, for example, as an antistatic layer, a surfactant such as an antistatic agent or an antifogging agent, or a conductive substance such as a hydrophilic polymer is used. It can be prepared by coating on the surface of the sheet, or it can be prepared as a sheet by kneading an antistatic agent, an antifogging agent or the like into the resin. For example, in the case of a polystyrene resin sheet, when an antistatic layer is formed by applying a conductive material or the like to the surface of a polystyrene resin substrate layer, the coating amount is preferably in the range of ^{20 to} 500 mg / m ^2. If the surface resistivity of the resin sheet is greater than 10 ¹⁴ Ω, as described above, frictional charging during continuous molding may be significant, and the molded product may adhere to the mold part, making it difficult to take out and feed. is there. Further, in order to set the static friction coefficient of the sheet surface to 0.1 to 0.4, for example, as a functional layer, a surface lubricant such as polysiloxane resin is applied to the surface of the sheet, or surface lubricity is produced. An agent or the like can be kneaded into a resin to produce a sheet. In production of the functional layer, the polysiloxane resin can be used in the form of either an oil or an aqueous emulsion, and when applied, a coating amount in the range of 0.1 to 50 mg / m ² is preferred. As described above, an antistatic layer having an antistatic effect having a predetermined surface specific resistance value or static friction coefficient by directly kneading an antistatic agent, a surface lubricant or the like into the raw material resin of the base material layer. Can be substituted.

  The printed layer as the functional layer is provided for product display and surface decoration filled in a sealed container, and is provided on the surface of the base material layer. It may be provided between the functional layer, but when it has other functional layers on both sides or one side of the base material layer, it may be provided between the base material layer and the other functional layer. It is preferable that the printed surface is not dropped or damaged due to friction between the sheet and the mold during cold forming. As a printing layer forming method, a method of forming by printing on the surface of the base material layer, a method of forming by laminating other functional layers on the printing surface applied to the surface of the base material layer, In addition, a method of forming the film on the back side of the other functional layer produced as a film and also using the print layer and laminating the print layer combined film so that the print surface is in contact with the base material layer, For example, a method in which a separately printed film is used as a printing layer, and this film is laminated between a base material layer and another functional layer. The printed layer may be decorated with metallic luster.

  The barrier layer as the functional layer imparts weather resistance, gas barrier properties, etc. to light and gas to the resin sheet. In the case of a lid of a container formed from the resin sheet, the barrier layer prevents the filler from being altered. It is provided to add a perfume function and a function to prevent permeation of water vapor and harmful gases. The barrier layer is usually produced as a gas-impermeable film, and when another functional layer is provided on the surface of the base material layer, both surfaces of the base material layer or one of the one surface, the other functional layer and the base material It is provided between the layers, for example, between the sealant layer and the base material layer. As the gas-impermeable film, a resin film prepared from a resin containing a resin component constituting the base material layer is preferable, and an ultraviolet absorber or the like can be contained as necessary. The thickness of the gas-impermeable film forming such a barrier layer is usually in the range of 10 to 100 μm.

  The strength reinforcing layer as the functional layer is fixed to the resin molded product when, for example, a resin molded product such as a container containing a polystyrene resin as a main component and a cold molded product such as a lid are ultrasonically welded. It is provided to give resistance against damage to the corner (edge part) of the top surface of the lid corresponding to the welded part, that is, edge breakage, when the cold-formed processed product is peeled with a finger. The edge breakage can be suppressed by providing a strength reinforcing layer having a function of reinforcing the strength between the base material layer and the sealant layer. The strength reinforcing layer preferably includes a polyolefin-based resin. Examples of the polyolefin-based resin include high-density polyethylene, low-density polyethylene, EVA (ethylene-vinyl acetate copolymer) resin, and EVOH (ethylene-vinyl alcohol). (Copolymer) resins such as polyethylene resins and polypropylene resins can be mentioned, among which low density polyethylene is preferable, and LLDPE (linear low density polyethylene) is particularly preferable. In general, the thickness of the strength reinforcing layer is preferably in the range of 10 to 100 μm, and particularly preferably in the range of 20 to 45 μm.

  The wear-resistant layer as the functional layer is, for example, when the base material layer is mainly composed of a polystyrene resin having poor wear resistance, the surface is damaged during cold molding, or the resin molded product and the cold molded product Is provided to provide resistance against damage such as perforation or tearing in the skirt portion of the lid due to the influence of ultrasonic vibration on the damaged portion of the surface. By providing the wear layer on the outermost surface, damage during cold forming or ultrasonic welding can be prevented. The wear-resistant layer is not particularly limited as long as it contains a wear-resistant resin, and a layer containing a polyolefin-based resin and / or a nylon resin, particularly a laminating film can be preferably exemplified. Examples of the polyolefin resin include polyethylene resins such as high density polyethylene, low density polyethylene, EVA (ethylene-vinyl acetate copolymer) resin, EVOH (ethylene-vinyl alcohol copolymer) resin, and CPP (unstretched polypropylene). ), OPP (biaxially oriented polypropylene), and the like, can be exemplified, but CPP is particularly preferable because it is excellent in shape retention of the lid by cold forming.

  The adhesive strength between the sealant layer and the base material layer as the functional layer, or the adhesive strength between the strength reinforcing layer and the base material layer as the functional layer is 3N / 15 mm width or more, particularly 5 to 8 N / 15 mm width. preferable. When the adhesive strength between the sealant layer and the base material layer or the strength reinforcing layer and the base material layer is 3 N / 15 mm width or more, the sealant layer is peeled off when the cold-formed product fixed to the resin molded product is peeled off with a finger. Occurrence of delamination between the base material layer or the strength reinforcing layer and the base material layer can be suppressed, and the base material layer and the sealant layer or the strength reinforcing layer are peeled off between the resin molded product and the cold molded product. It can be avoided that the fragments of the sealant layer due to delamination between the substrate and the base material layer adhere to the resin molded product and remain, and if the width is 5 to 8 N / 15 mm or more, a more remarkable effect is obtained. can get. The adhesive strength can be measured by the following method based on JIS-K6854. That is, using a tensile tester, the unbonded portions of the base material layer and the sealant layer or the strength reinforcing layer and the base material layer are sandwiched with chucks, the opening degree of both layers is 180 °, and the tensile speed is 300 mm / min. Pull and measure the load at that time. The adhesive strength can be obtained by converting the load per adhesive width of 15 mm. In addition, if even better peelability is required between the resin molded product and the cold-formed product, the flexibility of the functional layer is made larger than that of the base material layer in order to obtain a comfortable peel property. The hardness is preferably smaller than that of the base material layer.

  By the way, as described above, the resin sheet for cold forming is usually molded at room temperature without being heated, pressed into a female mold with a male mold, and pressed at a high speed, thereby forming, bending, shearing and drawing. However, from this viewpoint, a high-speed impact test at room temperature is considered to be effective as a model evaluation method for plastic deformation of resin sheets. The resin sheet for cold forming preferably has a specific value for propagation energy and maximum load displacement when measured by a falling weight impact test method based on ASTM-D3763.

  For example, when the sheet for cold forming contains a polystyrene resin, the propagation energy in a 150 μm-thick sheet measured by a falling weight impact test method based on ASTM-D3763 is 0.015 J or more, particularly 0.02 J or more. It is preferable. If the propagation energy is 0.015 J or more, the lid of the cold-formed product that can be sufficiently plastically deformed without breaking the sheet material has a uniform shape and has shape retention, and if it is 0.02 J or more This effect becomes more prominent. Here, the propagation energy in the drop weight impact test is the absorbed energy from the displacement at the maximum load to the displacement at break in the total absorbed energy required for the fracture obtained in the drop weight impact test. In addition, the measured value obtained by the falling weight impact is a value measured at a falling speed of 5.0 M / sec using a weight of φ45 mm for the holder and φ13 mm for the hitting core.

  Similarly, when the cold forming sheet contains a polystyrene-based resin, the maximum load displacement in a 150 μm-thick sheet measured by a falling weight impact test method in accordance with ASTM-D3763 is 10.0 mm or less, particularly 9.5 mm or less. It is preferable that When the maximum load indication displacement is 10.0 mm or less, the lid that can be sufficiently plastically deformed without breaking the sheet material has a uniform shape and has shape retention, and when the displacement is 9.5 mm or less, such an effect. Becomes more prominent. Here, the displacement at the maximum load in the drop weight impact test is a displacement amount (a displacement amount between the tip of the drop weight and the surface of the test piece sheet) when the load becomes maximum. In addition, the measured value obtained by the falling weight impact is a value measured at a falling speed of 5.0 M / sec using a weight of φ45 mm for the holder and φ13 mm for the hitting core.

  Such a cold-molding resin sheet can be colored such as white. In particular, when the sheet contains a polystyrene-based resin, it is preferable that one or both of the base material layer and the functional layer are colored white. When a sheet containing a polystyrene-based resin is molded, the bent portions that have undergone plastic deformation are whitened. Therefore, when these layers themselves are previously colored in white, the whitening of the bent portions due to plastic deformation can be unclear. In order to color these layers white, a sheet can be prepared by adding white pigments and dyes such as titanium oxide and zinc oxide to the raw material resin in the range of 0.5 to 8% by weight.

  The cold forming resin sheet can be produced by a known method using a sheet extrusion apparatus, a press processing apparatus, or the like. For example, a method of coextruding a base material layer and a functional layer simultaneously using a sheet extrusion device, a method of dry laminating a base material layer and a functional layer using a two-component reaction adhesive, etc. A method of laminating a functional layer with a thermal lamination method, a method of extrusion coating a functional layer on a base material layer, a method of printing on a base material layer or a functional layer, or these methods By using together, it can manufacture as a base material layer single layer or as a laminated body of a base material layer and 1 or 2 or more functional layers.

  The cold forming resin sheet has been described in detail above, but the thickness of the cold forming resin sheet varies depending on the type and shape of the cover of the cold formed product, and is not particularly limited. Those having a thickness of 0.2 mm or less recognized as a film and those having a thickness of 1 mm or more recognized as a thin plate are also included in the cold forming resin sheet used for cold forming. And when the resin sheet for cold forming is a sheet | seat containing a polystyrene-type resin, the thickness is 50 micrometers-1 mm, and the thing of 80 micrometers-300 micrometers is especially preferable. If the thickness of the sheet is 50 μm or more, a container lid having strength can be produced from the polystyrene-based resin sheet. If the thickness is 80 μm or more, the effect becomes more prominent. A lid having a shape retaining property can be obtained by plastic deformation of the sheet material during cold forming.

  As a manufacturing method of the lid | cover of the sealed container of this invention, if it uses the said cold forming resin sheet, it is a method of cold forming at the temperature below the glass transition point (Tg) of resin which comprises this resin sheet. There is no particular limitation. As described above, as described above, press molding is performed by pressing a resin sheet against a mold by an air flow such as vacuum molding or compression pneumatic molding, or press molding by pressing with a roll and embossing as described above. However, a resin sheet is sandwiched between a pair of male molds and female molds, the sheet is pushed into the female molds with a male mold, and pressed at a high speed to plastically deform the resin sheet. Molding to mold is preferable, and it is preferable to use a cold forming machine used for molding aluminum foil or the like. According to such cold forming, plastic deformation such as molding, bending, shearing, drawing, etc. can be generated on the sheet without heating, and molding can be performed by molding. In addition, the plastic deformation is a deformation that occurs when the material exceeds the elastic limit. When the material is subjected to a stress above the yield point, the deformation becomes significant, and a molded product having shape retention can be obtained. The molding pressure can be appropriately selected depending on the type of the resin sheet, the shape of the molded product, and the like, and is not particularly limited. As described above, high-speed pressing is usually performed at room temperature or normal temperature without heating, but in some cases, it is performed at a temperature substantially lower than the glass transition point (Tg) of the resin sheet under low-temperature heating. You can also.

  In particular, when a polystyrene resin sheet is cold formed using an aluminum foil cold forming machine to produce a container lid, the clearance between the male mold and the female mold is 1. It is preferable to perform molding using a mold adjusted to 3 to 4.0 times, and it is preferable to use a mold adjusted to 1.5 to 3.5 times. If the clearance between the male mold and the female mold is 1.3 times or more, the resin sheet will not be broken during molding. If the clearance between the male mold and the female mold is 4.0 times or less, the resin sheet The sheet is plastically deformed to produce a lid having shape retention. In such an aluminum foil cold molding machine, the molding pressure can be appropriately selected depending on the type of the resin sheet, the shape of the lid, and the like. As described above, high-speed pressing is usually performed at room temperature without heating, but in some cases, it can be performed at a temperature substantially lower than the glass transition point (Tg) of the resin sheet under low-temperature heating. In the case of a polystyrene resin sheet, it is less than 80 ° C., preferably 10 to 60 ° C., and more preferably at room temperature or room temperature.

  As a method of fixing the cold-molded lid to the opening of the resin container, any method such as adhesion or welding (fusion) may be used. As a welding method, hot plate welding, hot air welding, impulse welding may be used. Examples of the method include ultrasonic welding, and among these, the ultrasonic welding method is preferable in that welding can be performed more uniformly and at high speed. For example, ultrasonic welding between an open resin container and a lid made from a resin sheet having a sealant layer is performed using an ultrasonic welding machine having a specific specification for a specific application in addition to a normal ultrasonic welding machine. It can be carried out by applying an ultrasonic wave having a frequency of 15 to 50 kHz, preferably 20 to 40 kHz, and an amplitude of 16 to 126 μmpp, preferably 40 to 80 μmpp to the adhesive surface. As conditions for such ultrasonic welding, for example, when a cold-formed lid is sealed in a polystyrene resin container opening to form a sealed container, the frequency is 20 to 40 kHz, the output is 50 to 100 w / piece, and the irradiation time is 0.2 to 1 second is preferable, and the lid of a resin container such as a beverage container welded under such conditions can be peeled with a finger, and the peel strength is such that the lid does not peel even if the sealed container is inadvertently dropped. can get. Also, as an adhesion method, various adhesives are applied to a predetermined surface of a lid or a resin container, or a sealant layer containing an adhesive component is provided on a cold forming resin sheet. By using a sealant layer capable of obtaining a fixing strength that can be peeled off, a method of adjusting the fixing strength and appropriately applying pressure and welding can be exemplified.

  As the adhesive strength between the resin container and the lid, the peel strength is preferably in the range of 6 to 20 N / 15 mm width in the 180 ° peel test according to JIS-K6854, and more preferably in the range of 8 to 15 N / 15 mm width. It is more preferable that The peel strength is obtained by welding a sheet made of a resin raw material having the same composition as that of the resin molded product and a cold-molding resin sheet by, for example, ultrasonic welding, and setting the opening degree of both sheets to 180 °. When the peel strength is 6 N / 15 mm width or more, even if the sealed container is dropped with the contents filled, the lid peels off from the container and the contents leak. In addition, if the peel strength is 20 N / 15 mm width or less, it is not difficult to peel the lid by hand. It is more preferable that the peel strength is in the range of 8 to 15 N / 15 mm width because the above-described effects can be obtained more reliably. Also, if the peel strength between the lid and the open resin container is within the above range, when the lid is pierced with a straw, there is no separation between the lid and the resin container, and the resin container is filled. Beverages can be drunk.

  As a manufacturing method of the sealed container of the present invention, the cover-shaped cover material is punched out from the resin sheet, and after forming the cover by cold forming almost simultaneously, the cover is supplied to the opening of the resin container, Specific examples include a method of fixing the lid.

  The lid can be cold-molded using a mold and molded in a temperature atmosphere lower than the glass transition point (Tg) of the resin. For example, using a cold forming machine that is widely used for molding aluminum foil, etc., it is sandwiched between a male mold and a female mold, and the resin yield point exceeds the elastic limit of the lid at room temperature without heating. By applying the above pressure, plastic deformation such as shearing, bending, drawing or shaping is applied to the cover material, and the cover having shape retention can be formed by shaping.

  When the lid of the sealed container of the present invention is made of polystyrene resin, for example, in order to perform cold forming using an aluminum foil cold forming machine, the clearance between the male mold and the female mold is the thickness of the lid material. For example, it is preferable to use a mold adjusted to 1.3 to 4.0 times with respect to 50 μm to 1 mm. Furthermore, it is preferable to use a mold adjusted to 1.5 times to 3.5 times. If the clearance between the male mold and the female mold is 1.3 times or more, the lid material will not be destroyed during molding, and if the clearance between the male mold and the female mold is 4.0 times or less, The lid member is plastically deformed, and a molded product having shape retention can be produced. As molding conditions at this time, it is preferable to pressurize at 10 to 60 ° C., particularly at room temperature or room temperature. After molding the lid, the lid material is supplied to the opening of the resin container filled with the contents, and ultrasonic waves of 20 to 40 kHz are applied on the lid for 0.2 to 1 second by an ultrasonic welding machine so as to have the above peeling strength. Can be welded and sealed with a resin container.

  Hereinafter, examples of the sealed container of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to these examples.

[Preparation of resin sheet for cold forming]
Using a 65 mmφT die extruder, the resin was melt extruded to produce 150 μm thick sheets of the following specific examples 1-12.
Example 1
A high-impact polystyrene having a weight average molecular weight of 230,000, a rubber amount of 12% by weight, a liquid paraffin amount of 1.0% by weight, a soft component particle swelling degree of 12 and a soft component particle average particle size of 3.4 μm is melt extruded. As shown in FIG. 1, the sheet | seat of the base material layer 1 was obtained. Thereafter, a 30 μm sealant film (LDPE layer 15 μm + adhesive layer 15 μm; ZH-41 manufactured by J Film Co., Ltd.) was laminated on one side by a dry lamination method to produce a sealant layer 2. The peel strength between the polystyrene resin sheet and the sealant film was 4 N / 15 mm width. On the surface of the base material layer 1 opposite to the surface on which the sealant layer 2 is laminated, using a roll coater, an aqueous solution in which a surfactant (Electro Stripper AC manufactured by Kao Corporation) is diluted to a concentration of 30% is applied, An antistatic layer 3 was produced on the sheet surface.

Example 2
Impact polystyrene having a weight average molecular weight of 230,000, rubber content of 12% by weight, liquid paraffin content of 1.0% by weight, soft component particle swelling degree of 12, soft component particle average particle size of 3.4 μm, and styrene -A butadiene copolymer (TR2003 manufactured by JSR Corporation; styrene content 40 wt%, butadiene content 60 wt%) was blended at a ratio of 90/10 wt%, and then melt-extruded to obtain a sheet of the base layer 1. Thereafter, a 30 μm sealant film (LDPE layer 15 μm + adhesive layer 15 μm; ZH-41 manufactured by J Film Co., Ltd.) was laminated on one side by a dry lamination method to produce a sealant layer 2. On the surface of the base material layer 1 opposite to the surface on which the sealant layer 2 is laminated, using a roll coater, an aqueous solution in which a surfactant (Electro Stripper AC manufactured by Kao Corporation) is diluted to a concentration of 30% is applied, The antistatic layer 3 was produced on the sheet surface, and the resin sheet shown in FIG. 1 was obtained.

Example 3
Impact polystyrene having a weight average molecular weight of 230,000, rubber content of 12% by weight, liquid paraffin content of 1.0% by weight, soft component particle swelling degree of 12, soft component particle average particle size of 3.4 μm, and styrene -A butadiene copolymer (TR2003 manufactured by JSR Corporation) was blended at a ratio of 90/10% by weight, and then melt-extruded to obtain a sheet of the base material layer 1 as shown in FIG. Thereafter, a 30 μm sealant film (LDPE layer 15 μm + adhesive layer 15 μm; ZH-41 manufactured by J Film Co., Ltd.) was laminated on one side by a dry lamination method to produce a sealant layer 2. A 20 μm back-printed polystyrene resin film was laminated on the surface of the base material layer 1 opposite to the surface on which the sealant layer 2 was laminated by the dry lamination method, and the printed layer 4 was produced. An aqueous solution in which a surfactant (Electro Stripper AC manufactured by Kao Corporation) is diluted to a concentration of 30% is applied to the surface of the polystyrene resin film of the printed layer 4 using a gravure coater, and the antistatic layer 3 is applied to the sheet surface. Was made.

Example 4
A high-impact polystyrene having a weight average molecular weight of 220,000, a rubber amount of 8% by weight, a liquid paraffin amount of 0.5% by weight, a soft component particle swelling degree of 11 and a soft component particle average particle diameter of 1.0 μm is melt extruded. A sheet of the base material layer 1 was obtained. Other than that was carried out similarly to the specific example 1, and obtained the sheet | seat shown in FIG.

Example 5
An impact-resistant polystyrene having a weight average molecular weight of 240,000, a rubber amount of 6.6% by weight, a liquid paraffin amount of 2.5% by weight, a soft component particle swelling degree of 12, and a soft component particle average particle diameter of 3.5 μm. The sheet of the base material layer 1 having a thickness of 150 μm was obtained by melt extrusion. Other than that was carried out similarly to the specific example 1, and obtained the sheet | seat shown in FIG.

Example 6
A high-impact polystyrene having a weight average molecular weight of 250,000, a rubber amount of 9.7% by weight, a liquid paraffin amount of 0% by weight, a soft component particle swelling degree of 12, and a soft component particle average particle diameter of 2.7 μm is melt-extruded. A sheet of the base material layer 1 was obtained. Other than that was carried out similarly to the specific example 1, and obtained the sheet | seat shown in FIG.

Example 7
A high-impact polystyrene having a weight average molecular weight of 160,000, a rubber content of 14% by weight, a liquid paraffin content of 0% by weight, a soft component particle swelling degree of 12 and a soft component particle average particle size of 3.6 μm is melt extruded. A sheet of material layer 1 was obtained. Other than that was carried out similarly to the specific example 1, and obtained the sheet | seat shown in FIG.

Example 8
A high-impact polystyrene having a weight average molecular weight of 230,000, a rubber amount of 12% by weight, a liquid paraffin amount of 1.0% by weight, a soft component particle swelling degree of 12 and a soft component particle average particle size of 3.4 μm is melt extruded. A sheet of the base material layer 1 was obtained. Thereafter, a sealant film of 30 μm (LDPE layer 15 μm + adhesive layer 15 μm; ZH-41 manufactured by J-Film Co., Ltd.) is laminated on one side to produce the sealant layer 2, and then the base on the side opposite to the side on which the sealant layer 2 is laminated. On the surface of the material layer 1, an aqueous solution of polydimethylsiloxane aqueous solution (KM787 manufactured by Shin-Etsu Chemical Co., Ltd.) diluted to 30% concentration was applied to the sheet surface using a gravure coater to produce an antistatic layer 3. The sheet shown in 1 was obtained.

Example 9
An impact-resistant polystyrene having a weight average molecular weight of 230,000, a rubber amount of 12% by weight and a liquid paraffin amount of 1.0% by weight was melt-extruded to obtain a sheet of the base material layer 1. Thereafter, a sealant film of 30 μm (LDPE layer 15 μm + adhesive layer 15 μm; ZH-41 manufactured by J-Film Co., Ltd.) is laminated on one side to produce the sealant layer 2, and then the base on the side opposite to the side on which the sealant layer 2 is laminated. On the surface of the material layer 1, a mixed solution of a surfactant (Electro Stripper AC manufactured by Kao Corporation) and polydimethylsiloxane (KM787 manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to produce an antistatic layer 3, which is shown in FIG. A sheet was obtained.

Example 10
1 part by weight of a surfactant (Electro Stripper AC manufactured by Kao Corporation) is added to a high-impact polystyrene having a weight average molecular weight of 230,000, a rubber amount of 12% by weight, and a liquid paraffin content of 1.0% by weight, and melt extruded. 1 sheet was obtained. Thereafter, a 30 μm sealant film (LDPE layer 15 μm + adhesive layer 15 μm; ZH-41 manufactured by J-Film Co., Ltd.) was laminated on one side to produce a sealant layer 2, and the sheet shown in FIG. 3 was obtained.

Specific Example 11
Impact polystyrene having a weight average molecular weight of 230,000, rubber content of 12% by weight, liquid paraffin content of 1.0% by weight, soft component particle swelling degree of 12, soft component particle average particle size of 3.4 μm, and styrene -A butadiene copolymer (TR2003 manufactured by JSR Corporation; styrene content 40 wt%, butadiene content 60 wt%) was blended at a ratio of 90/10 wt%, and then melt-extruded to obtain a sheet of the base layer 1. Thereafter, a 50 μm reinforcing sealant film (LLDPE layer 35 μm + sealant layer (adhesive layer) 15 μm) is laminated on one side, and a gravure coater is used on the surface of the base material layer 1 opposite to the side on which the reinforcing sealant film is laminated. Then, an aqueous solution obtained by diluting a surfactant (Electro Stripper AC manufactured by Kao Corporation) to a concentration of 30% was applied to produce the antistatic layer 3, and the sheet shown in FIG. 4 was obtained.

Example 12
Impact polystyrene having a weight average molecular weight of 230,000, rubber content of 12% by weight, liquid paraffin content of 1.0% by weight, soft component particle swelling degree of 12, soft component particle average particle size of 3.4 μm, and styrene -A butadiene copolymer (TR2003 manufactured by JSR Corporation; styrene content 40 wt%, butadiene content 60 wt%) was blended at a ratio of 90/10 wt%, and then melt-extruded to obtain a sheet of the base layer 1. Thereafter, a 65 μm reinforcing sealant film (LLDPE layer 50 μm + sealant layer (adhesive layer) 15 μm) was laminated on one side, and a 30 μm back-print was printed on the surface of the base material layer 1 opposite to the side on which the reinforcing sealant film was laminated. A CPP (unstretched polypropylene) film 6 was laminated. An aqueous solution obtained by diluting a surfactant (Electro Stripper AC, manufactured by Kao Corporation) to a concentration of 30% is applied to the surface of the CPP film 6 using a gravure coater to produce an antistatic layer 3, and the sheet shown in FIG. Obtained.

Reference Example An aluminum foil having a thickness of 60 μm was used for the lid sheet.

[Production of lid]
The various sheets of Examples 1 to 10 were pressed and pressed with a male mold against a female mold in a 23 ° C. atmosphere using a cold forming machine in a 23 ° C. atmosphere, and the cap shown in FIG. A shaped lid 7 was obtained. The clearance between the male mold and the female mold was 0.3 mm, and continuous molding was performed. The flat part of the lid 7 was 24.5 mm, and the length of the crease part (skirt S) was 5 mm. In the aluminum foil having a thickness of 60 μm of the reference example, the clearance between the male mold and the female mold of the cold forming machine was set to 1.0 mm, and the other processes were performed in the same manner as in the specific example.

[Production of sealed containers]
A container 8 shown in FIG. 7 was produced by an injection blow molding method. The flange diameter of the container 8 was 24.0 mm and the capacity was 65 cc. As the resin, impact resistant polystyrene (H440X manufactured by Nippon Polystyrene Co., Ltd.) was used. The container and the lid were welded by an ultrasonic welding method under conditions of a frequency of 20 kHz, an amplitude of 100 μmpp, and 0.5 seconds to obtain a sealed container shown in FIG.

[Characteristic test]
About the sheet | seat obtained in Example 1, the falling weight impact test is performed with the following method, surface specific resistance and a static friction coefficient are measured, About the lid | cover obtained in Example 2, and the sealed container obtained in Example 3 Evaluation of performance and formability was performed by four-step evaluation (（, ○, Δ, ×). The results are shown in Table 2.
(1) Falling weight impact test It was based on ASTM D3763. A GRAPHIC IMPACT TESTER manufactured by Toyo Seiki Seisakusho Co., Ltd. was used as a measuring instrument, and the propagation energy and displacement at the maximum load were measured. The holder was a spindle having a diameter of 45 mm, the hitting core was φ13 mm, and the hitting speed of the hitting core was 5.0 M / sec. The load cell load was 5000 lb, the load amplifier range was 1 Kunit, the sampling time was 2 μs, and the load input sensitivity was 5 V.
(2) Measurement of surface resistivity It conformed to JIS-K6911. A digital ultrahigh resistance / microammeter manufactured by Advantest Co., Ltd. was used as the measuring instrument.
(3) Measurement of static friction coefficient It was based on JIS-K7125. A friction measuring instrument TR manufactured by Toyo Seiki Seisakusho Co., Ltd. was used as the measuring instrument.
(4) Lid strength at molding 13,000 shots were molded per hour using a cold molding machine. The molded lid was visually checked for damage.
(5) Continuous cold formability 13,000 shots were formed per hour using a cold forming machine. It was confirmed that the molded lid did not adhere to the mold part.
(6) Lid strength during ultrasonic welding A cold-formed lid was welded to a 65 cc container having a flange diameter of φ24.0 mm by ultrasonic welding. The welded sealed container lid was visually inspected for damage (opening or tearing).
(7) Shape retention The angle α between the flat portion and the fold of the molded lid was determined and determined as follows. The determination was performed immediately after molding and after 2 hours. In the table, the folding angle α is indicated as follows: ○: 130 ° or less, Δ: exceeding 130 ° to 150 ° or less, and x: exceeding 150 °.
(8) Sealing property The lid of the welded sealed container was tapped with a fingertip to check whether the lid was adhered to the container.
(9) Peelability of sealant layer The lid of the sealed container was peeled off by hand, and it was visually confirmed whether the sealant layer remained in the container.
(10) Lid strength at opening When the lid of the sealed container was peeled off by hand, it was confirmed that the lid was not torn (edge breakage).
(11) Lid strength at the time of dropping The sealed container was naturally dropped from a height of 100 cm, and it was confirmed whether or not the lid was torn.
(12) Peelability between the lid and the container The resin sheet for the lid and the sheet prepared using the container raw material were welded by an ultrasonic welding method. The peel strength at 180 ° was measured and judged with the opening degree of both sheets being 180 degrees. The tester used Shimadzu Corporation autograph AG-500B, and the peeling rate was 300 mm / min. In the table, O: 6 to 20 N / 15 mm width, Δ: less than 6 N / 15 mm width, and over 20 N / 15 mm width.
(13) Recyclability It was evaluated whether it was necessary to separate the lid and the container. In the table, “O” indicates that separation is not necessary, and “X” indicates that separation is necessary.
(14) Metal detection possibility It was evaluated whether inspection was possible using a metal detector. In the table, “O” indicates that inspection is possible, and “X” indicates that inspection is impossible.

It is a figure which shows one Example of the resin sheet for cold forming used for preparation of the lid | cover of the sealed container of this invention. It is a figure which shows one Example of the resin sheet for cold forming used for preparation of the lid | cover of the sealed container of this invention. It is a figure which shows one Example of the resin sheet for cold forming used for preparation of the lid | cover of the sealed container of this invention. It is a figure which shows one Example of the resin sheet for cold forming used for preparation of the lid | cover of the sealed container of this invention. It is a figure which shows one Example of the resin sheet for cold forming used for preparation of the lid | cover of the sealed container of this invention. It is a figure which shows the lid | cover of one Example of the sealed container of this invention. It is a figure which shows the resin container of one Example of the sealed container of this invention. It is a figure which shows one Example of the sealed container of this invention.

Explanation of symbols

1 …… Base material layer 2 …… Sealant layer (functional layer)
3 ... Antistatic layer (functional layer)
4. Print layer (functional layer)
5. Strength reinforcement layer (functional layer)
6 …… Surface layer (functional layer)
7 …… Lid 8 …… Container

Claims (55)

A sealed container comprising a resin container and a lid fixed to the resin container,
A lid having shape retention is produced by cold molding a resin sheet for cold molding,
The resin sheet is a resin sheet comprising a base material layer containing a polystyrene resin in which a base material layer containing a polystyrene resin or a functional layer is laminated,
The sealed container , wherein the polystyrene-based resin contains a composition composed of high-impact polystyrene (HIPS) and a styrene-butadiene copolymer . High impact polystyrene is obtained by polymerizing a styrene monomer in the presence of a rubbery polymer, the weight average molecular weight of the matrix is 150,000 to 300,000, the styrene content is 82 to 94% by weight, the rubber content There 6 to 15 wt%, sealed container according to claim 1, wherein the liquid paraffin content is characterized by a high impact polystyrene is 0-3.0 wt% (a). The sealed container according to claim 2, wherein the impact-resistant polystyrene (A) has soft component particles having a degree of swelling of 30 or less and an average particle diameter in the range of 0.5 to 10 µm. Styrene - butadiene copolymer, a styrene content of 30 to 90% by weight, a butadiene content of styrene is 10 to 70 wt% - any of claims 1 to 3, wherein the butadiene copolymer (B) Or a sealed container. 5. The composition according to claim 1 , comprising a composition comprising 100 to 70% by weight of impact-resistant polystyrene (A) and 0 to 30% by weight of a styrene-butadiene copolymer (B). Sealed container. Cold forming a resin sheet, on both sides or one side of the base layer, one or sealed container according to any one of claims 1 to 5 which are stacked two or more layers and having a functional layer are. The sealed container according to claim 1 , wherein the cold-molding resin sheet has a sealant layer as a functional layer. The sealed container according to claim 7 , wherein the sealant layer contains a thermoplastic elastomer and / or an ethylene-based copolymer. The sealed container according to claim 1 , wherein the cold-molding resin sheet has an antistatic layer as a functional layer. The sealed container according to claim 1 , wherein the cold-molding resin sheet has a printed layer as a functional layer. The sealed container according to claim 1 , wherein the cold-molding resin sheet has a barrier layer as a functional layer. The sealed container according to any one of claims 1 to 11 , wherein the cold-molding resin sheet has a strength reinforcing layer as a functional layer. The sealed container according to claim 12 , wherein the strength reinforcing layer is provided between the sealant layer and the base material layer. The sealed container according to claim 13 , wherein the strength reinforcing layer contains a polyolefin resin. The sealed container according to claim 14 , wherein the polyolefin resin is LLDPE (linear low density polyethylene). The sealed container according to any one of claims 1 to 15 , wherein the cold-molding resin sheet has a wear-resistant layer as a functional layer on a surface layer. The sealed container according to claim 16 , wherein the wear-resistant layer is a layer containing a polyolefin resin and / or a nylon resin. The sealed container according to claim 17 , wherein the polyolefin resin is CPP (unstretched polypropylene). The sealed container according to claim 1 , wherein the cold-molding resin sheet has a functional layer containing the same kind of resin as the base material layer. 20. The sealed container according to claim 19 , wherein the same kind of resin as the base material layer has a functional layer containing general purpose polystyrene (GPPS) and / or a styrene-butadiene copolymer. The sealed container according to any one of claims 1 to 20 , wherein the cold-molding resin sheet has at least one surface having a surface resistivity of 10 ⁶ to 10 ¹⁴ Ω. The sealed container according to any one of claims 1 to 21 , wherein the cold-molding resin sheet has at least one surface having a surface static friction coefficient in the range of 0.1 to 0.4. The sealed container according to any one of claims 1 to 22 , wherein the cold-molding resin sheet is colored in white. For cold forming resin sheet, sealed container according to any one of claims 1 to 23, characterized in that the thickness of 50Myuemu～1mm. Peel strength between the resin container and lid, sealed container according to any one of claims 1-24, characterized in that the 2~30N / 15mm width at 180 ° peel test. The sealed container according to claim 25 , wherein the adhesive strength between the base material layer and the sealant layer or the strength reinforcing layer is 3 N / 15 mm width or more. A cold-molding resin sheet is cold-molded at a temperature lower than the glass transition point of the resin constituting the resin sheet to produce a shape-retaining lid, and a sealed container for fixing the lid to the resin container A manufacturing method comprising:
The resin sheet is a resin sheet comprising a base material layer containing a polystyrene resin in which a base material layer containing a polystyrene resin or a functional layer is laminated,
The method for producing a sealed container, wherein the polystyrene resin contains a composition comprising high impact polystyrene (HIPS) and a styrene-butadiene copolymer . 28. The method for manufacturing a sealed container according to claim 27 , wherein the cold forming is performed by pressing and pressing a cold forming resin sheet with a male die against a female die. 29. The method for producing a sealed container according to claim 28 , wherein the clearance between the male mold and the female mold is adjusted to 1.3 to 4.0 times the thickness of the cold forming resin sheet. . The method for producing a sealed container according to any one of claims 27 to 29 , wherein the resin container and the lid are fixed to each other by an ultrasonic welding method. High impact polystyrene is obtained by polymerizing a styrene monomer in the presence of a rubbery polymer, the weight average molecular weight of the matrix is 150,000 to 300,000, the styrene content is 82 to 94% by weight, the rubber content The method for producing a sealed container according to any one of claims 27 to 30, wherein the impact-resistant polystyrene (A) is 6 to 15% by weight and the amount of liquid paraffin is 0 to 3.0% by weight. 32. The method for producing a sealed container according to claim 31, wherein the impact-resistant polystyrene (A) has soft component particles having a degree of swelling of 30 or less and an average particle diameter in the range of 0.5 to 10 [mu] m. Styrene - butadiene copolymer, a styrene content of 30 to 90% by weight, a butadiene content of styrene is 10 to 70 wt% - any of claims 27 to 32, wherein the butadiene copolymer (B) A method for producing a sealed container as described above. 34. The composition according to any one of claims 27 to 33 , comprising a composition comprising 100 to 70% by weight of impact-resistant polystyrene (A) and 0 to 30% by weight of a styrene-butadiene copolymer (B). A manufacturing method of a sealed container. The sealed container according to any one of claims 27 to 34 , wherein the cold-molding resin sheet has a functional layer in which one or two or more layers are laminated on both sides or one side of the base material layer. Production method. 36. The method for producing a sealed container according to claim 27 , wherein the cold-molding resin sheet has a sealant layer as a functional layer. The method for producing a sealed container according to claim 36 , wherein the sealant layer contains a thermoplastic elastomer and / or an ethylene-based copolymer. The method for producing a sealed container according to any one of claims 27 to 37 , wherein the cold-molding resin sheet has an antistatic layer as a functional layer. The method for producing a sealed container according to any one of claims 27 to 38 , wherein the cold-molding resin sheet has a printing layer as a functional layer. The method for manufacturing a sealed container according to any one of claims 27 to 39 , wherein the cold-molding resin sheet has a barrier layer as a functional layer. The method for producing a sealed container according to any one of claims 27 to 40 , wherein the cold-molding resin sheet has a strength reinforcing layer as a functional layer. 42. The method for producing a sealed container according to claim 41 , wherein the strength reinforcing layer is provided between the sealant layer and the base material layer. The method for producing a sealed container according to claim 42 , wherein the strength reinforcing layer contains a polyolefin-based resin. 44. The method for producing a sealed container according to claim 43 , wherein the polyolefin resin is LLDPE (linear low density polyethylene). The method for producing a sealed container according to any one of claims 27 to 44 , wherein the cold-molding resin sheet has a wear-resistant layer as a functional layer on a surface layer. 46. The method for producing a sealed container according to claim 45 , wherein the wear-resistant layer is a layer containing a polyolefin resin and / or a nylon resin. The method for producing a cold-formed product according to claim 46 , wherein the polyolefin resin is CPP (unstretched polypropylene). The method for producing a sealed container according to any one of claims 27 to 47 , wherein the cold-molding resin sheet has a functional layer containing the same kind of resin as the base material layer. 49. The method for producing a sealed container according to claim 48 , wherein the resin of the same type as the base material layer is general purpose polystyrene (GPPS) and / or styrene-butadiene copolymer. The method for producing a sealed container according to any one of claims 27 to 49 , wherein the cold-molding resin sheet has at least one surface having a surface specific resistance value in a range of 10 ⁶ to 10 ¹⁴ Ω. The method for producing a sealed container according to any one of claims 27 to 50 , wherein the cold-molding resin sheet has at least one surface having a surface static friction coefficient in the range of 0.1 to 0.4. The method for producing a sealed container according to any one of claims 27 to 51 , wherein the cold-molding resin sheet is colored in white. The method for producing a sealed container according to any one of claims 27 to 52, wherein the cold-molding resin sheet has a thickness of 50 µm to 1 mm . The method for producing a sealed container according to any one of claims 27 to 53, wherein the peel strength between the resin container and the lid is 6 to 20 N / 15 mm width in a 180 ° peel test. 55. The method for producing a sealed container according to claim 54 , wherein the adhesive strength between the base material layer and the sealant layer or the strength reinforcing layer is 3N / 15 mm width or more.

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