JP6135893B2 - Multi-layer sheet for secondary molding and package using the same - Google Patents

Description

  The present invention relates to a multilayer sheet formed by laminating a resin film and a thermoplastic resin sheet having different properties, and a packaging body such as a container, a tray or a lid formed by molding the multilayer sheet. Specifically, a cyclic polyolefin is used. It is a laminate of a resin film and a thermoplastic resin sheet, and relates to a multilayer sheet for secondary molding that can be suitably used as a packaging body for packaging food, pharmaceuticals and industrial parts, and a packaging body using the same. .

  Conventionally, as containers for storing dried foods, frozen foods / refrigerated foods, pharmaceuticals, electronic industrial parts, etc., polyethylene, expanded polyethylene, polystyrene, expanded polystyrene paper (PSP), polypropylene, expanded polypropylene are generally used. Containers formed by secondary molding such as vacuum molding and pressure molding have been used. As containers that are particularly lightweight and excellent in heat insulation and volume reduction, foamed plastic sheets, specifically, foamed polyethylene, expanded polystyrene paper (PSP), expanded polypropylene, and the like have been frequently used. However, such a foamed plastic sheet has poor water vapor barrier properties, and in order to improve moisture resistance, it is necessary to increase the thickness of the sheet or to bond other films. The increase in thickness is inconsistent with the recent volume reduction due to environmental considerations, and further has the problem of increasing the amount of heat and molding time required for container molding. Also, in the case of laminated sheets with other films bonded together, the molding conditions of the sheet and film do not match, and the film may be cracked or appearance defects such as laminate lifting may occur. The trouble of adjusting the molding conditions has occurred.

  As a method for improving moisture resistance, methods using various resins other than the above and multilayer structures of multilayer sheets are provided (for example, see Patent Documents 1 to 3). Patent Documents 1 and 2 exemplify a container using a single layer of a cyclic polyolefin resin having moisture-proof performance, and a 300 μm multilayer sheet and a packaging container in which the resin is disposed in the center layer. Since these are mainly composed of cyclic polyolefin and have a large thickness and composition ratio, an increase in cost is unavoidable as compared with the case of using a general polyolefin-based resin. In order to secure interlayer adhesion between the resin layer containing cyclic polyolefin and the adjacent resin layer, the strength is improved by arranging an adhesive resin layer or blending various compatibilizers. However, the adhesive resin is also expensive and causes a cost increase, and depending on the difference in flowability from the resin to be further blended, it may be necessary to devise to obtain the uniformity of the sheet performance, Work efficiency may be extremely deteriorated.

  In addition, a technique in which interlayer adhesion and secondary moldability are improved by the combined use of cyclic polyolefin and low density polyethylene is also provided (see, for example, Patent Document 4), which is also an intermediate resin mainly composed of cyclic polyolefin. Due to the thickness of the film, it is inevitable to raise the cost, and because it is a multilayer film mainly composed of polyethylene with low rigidity, it is difficult to use as a strong and rigid packaging container formed by deep drawing. There is a problem.

JP-A-7-216152 JP 2010-194751 A JP 2010-105318 A JP 2007-245612 A

  An object of the present invention is made in view of the above-described problems, and relates to a relatively inexpensive package of food / pharmaceutical products and industrial products, and particularly has good moisture resistance, such as packaging containers and trays. The present invention provides a multilayer sheet for secondary molding excellent in secondary molding processing characteristics and a package using the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a multilayer sheet formed by laminating a film mainly composed of cyclic polyolefin and a thermoplastic resin sheet. The headline and the present invention were completed.

  That is, the present invention is characterized in that a film (I) having a resin layer (A) whose main component is a cyclic polyolefin resin (a1) and a thermoplastic resin sheet (II) of 300 μm or more are laminated. The multilayer sheet | seat for secondary shaping | molding to perform and the package formed by carrying out the secondary shaping | molding process of this are provided.

  The multilayer sheet of the present invention is obtained by laminating a film excellent in moisture resistance and secondary formability to a sheet that is rigid and versatile and excellent in cost performance, and easily imparts moisture resistance to these sheets. Can do. Because the sheet to be bonded can be freely changed, moisture resistance can be easily added to polypropylene, polyethylene and polystyrene sheets, which are conventionally known as materials with poor moisture resistance. It does not impair the performance and heat insulation. Furthermore, the film itself to be bonded is a thin film while having rigidity, so that there is no peeling between the film and the sheet when the multilayer sheet of the present invention is subjected to secondary processing, warpage, etc. It can be suitably applied to a packaging container, a lid material, a tray, or the like for a packaging body formed by packaging these directly or for materials.

  The multilayer sheet of the present invention is characterized in that a film (I) having a resin layer (A) mainly composed of a cyclic polyolefin-based resin (a1) and a thermoplastic resin sheet (II) of 300 μm or more are laminated. And In the present invention, “main component” means that the specific resin is contained at 50% by mass or more with respect to the total mass of the resin component used for forming the resin layer. Preferably, it is contained at 60% by mass or more.

  Examples of the cyclic polyolefin resin (a1) that is the main component of the resin layer (A) in the present invention include a norbornene polymer, a vinyl alicyclic hydrocarbon polymer, and a cyclic conjugated diene polymer. Among these, norbornene-based polymers are preferable. The norbornene-based polymer includes a ring-opening polymer of a norbornene-based monomer (hereinafter referred to as “COP”), a norbornene-based copolymer obtained by copolymerizing a norbornene-based monomer and an olefin such as ethylene (hereinafter, referred to as “COP”). , “COC”). Furthermore, COP and COC hydrogenates are particularly preferred. In addition, the weight average molecular weight of the cyclic polyolefin resin (a1) is preferably 5,000 to 500,000, more preferably 7,000 to 300,000.

  The norbornene monomer used as a raw material for the norbornene polymer is an alicyclic monomer having a norbornene ring. Examples of such norbornene-based monomers include norbornene, tetracyclododecene, ethylidene norbornene, vinyl norbornene, ethylidetetracyclododecene, dicyclopentadiene, dimethanotetrahydrofluorene, phenyl norbornene, methoxycarbonyl norbornene, methoxy And carbonyltetracyclododecene. These norbornene monomers may be used alone or in combination of two or more.

  The norbornene-based copolymer is a copolymer of the norbornene-based monomer and an olefin copolymerizable with the norbornene-based monomer, and examples of such olefin include the number of carbon atoms such as ethylene, propylene, and 1-butene. Examples thereof include olefins having 2 to 20; cycloolefins such as cyclobutene, cyclopentene, and cyclohexene; and non-conjugated dienes such as 1,4-hexadiene. These olefins can be used alone or in combination of two or more.

  The glass transition point (Tg) of the cyclic polyolefin resin (a1) is preferably 70 ° C. or higher from the viewpoint of the heat resistance and high rigidity of the obtained sheet. In view of the fact that it can be produced by a co-extrusion lamination method and from the viewpoint of easy availability of industrial raw materials, Tg is preferably 200 ° C. or lower. The temperature is particularly desirably 80 ° C to 180 ° C. As the cyclic polyolefin resin (a1) having such Tg, the content ratio of the norbornene monomer is preferably in the range of 20 to 90% by mass, more preferably 25 to 90% by mass, and still more preferably. 30 to 85% by mass. When the content ratio is within this range, the heat resistance, rigidity, moisture resistance, and processing stability are improved. In addition, the glass transition point (Tg) in this invention is a value obtained by measuring by DSC.

  On the other hand, norbornene copolymers with a high glass transition point (Tg) have low tensile strength, are too rigid, and are extremely easy to break and tear easily. In consideration of handleability, it is also possible to blend a high Tg product and a low Tg product having a glass transition point of less than 100 ° C.

  As a commercial product that can be used as the cyclic polyolefin resin (a1), examples of the ring-opening polymer (COP) of the norbornene monomer include “ZEONOR” manufactured by Nippon Zeon Co., Ltd., and norbornene. Examples of the system copolymer (COC) include “Appel” manufactured by Mitsui Chemicals, Inc., “TOPAS” manufactured by Polyplastics Co., Ltd., and the like.

  The resin layer (A) of the film (I) used in the present invention may be composed of the cyclic polyolefin resin (a1). However, the cost is reduced and the rigidity is too high for the above-mentioned handling. Other resins can also be used in combination, for example, in terms of difficulty and easy tearing. In this case, from the viewpoint of compatibility with the cyclic polyolefin resin (a1), the polyethylene resin (a2) and / or Alternatively, it is preferable to use a polypropylene resin (a3).

Examples of the polyethylene resin (a2), those densities be used 0.88 g / cm ² or more 0.970 g / cm ² less than the polyethylene-based resin, from the viewpoint of the secondary formability of the multilayer sheet obtained is there. In particular, high-density polyethylene is preferable from the viewpoint of moisture resistance.

  Examples of the polyethylene resin (a2) include polyethylene resins such as very low density polyethylene (VLDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and high density polyethylene (HDPE), and ethylene-vinyl acetate. Copolymer (EVA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate (EMA) copolymer, ethylene-ethyl acrylate-maleic anhydride copolymer Ethylene copolymers such as polymers (E-EA-MAH), ethylene-acrylic acid copolymers (EAA), ethylene-methacrylic acid copolymers (EMAA); and ionomers of ethylene-acrylic acid copolymers , Ethylene-methacrylic acid copolymer ionomer, etc. Among them, alone, it may be used by mixing two or more kinds. Among these, VLDPE, LDPE, and LLDPE are preferable from the viewpoints of processability (film formability), secondary moldability, and the like.

  The LDPE may be a branched low density polyethylene obtained by a high pressure radical polymerization method, and is preferably a branched low density polyethylene obtained by homopolymerizing ethylene by a high pressure radical polymerization method.

  As LLDPE, an ethylene monomer is the main component by a low-pressure radical polymerization method using a single site catalyst, and an α-olefin such as butene-1, hexene-1, octene-1, 4-methylpentene is used as a comonomer. Are copolymerized. As a comonomer content rate in LLDPE, it is preferable that it is the range of 0.5-20 mol%, and it is more preferable that it is the range of 1-18 mol%.

  Examples of the single-site catalyst include various single-site catalysts such as metallocene catalyst systems such as combinations of metallocene compounds of Group IV or V transition metals and organoaluminum compounds and / or ionic compounds. In addition, the single-site catalyst has a uniform active site, so the molecular weight distribution of the resulting resin is sharper than a multi-site catalyst with a non-uniform active site. The storage stability (physical property stability) is improved.

As described above, the density of the polyethylene resin (a2) is preferably 0.88 to 0.97 g / cm ³ . If the density is within this range, it has appropriate rigidity, excellent mechanical strength such as pinhole resistance, and film film formability and extrusion suitability are improved. Moreover, it is preferable that melting | fusing point is generally the range of 60-130 degreeC, and 70-120 degreeC is more preferable. If melting | fusing point is this range, process stability and coextrusion workability with cyclic polyolefin resin (a1) will improve. Moreover, it is preferable that it is 2-20 g / 10min, and, as for MFR (190 degreeC, 21.18N) of the said polyethylene-type resin, it is more preferable that it is 3-10 g / 10min. When the MFR is within this range, the extrusion moldability is improved.

  Since such a polyethylene resin (a2) has good compatibility with the cyclic polyolefin resin (a1), it is possible to maintain transparency when mixed. Further, since it has flexibility, the pinhole resistance is also good. Furthermore, when improving pinhole resistance, it is preferable to use VLDPE or LLDPE.

  Examples of the polypropylene resin (a3) include propylene homopolymer, propylene / α-olefin random copolymer, such as propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-ethylene-butene- 1 copolymer, metallocene catalyst type polypropylene, etc. are mentioned. These may be used alone or in combination. A propylene-α-olefin random copolymer is desirable, and a propylene / α-olefin random copolymer polymerized using a metallocene catalyst is particularly preferable. When these polypropylene resins (a3) are used, the heat resistance of the resulting film can be improved and the softening temperature can be increased, so that even when heat-laminated with the thermoplastic resin sheet (II) It can be suitably used.

  Further, these polypropylene resins (a3) preferably have an MFR (230 ° C.) of 0.5 to 30.0 g / 10 minutes and a melting point of 110 to 165 ° C., more preferably MFR (230 ° C. ) Is 2.0 to 15.0 g / 10 min, and the melting point is 115 to 162 ° C. If MFR and melting | fusing point are this range, the dimensional stability of the film obtained will be favorable and the film-forming property at the time of setting it as a film will also improve.

  In addition, for the purpose of further imparting moisture resistance to the film (I) used in the present invention, the resin layer (A) has a rosin resin such as petroleum resin, coumarone-indene resin, terpene resin, polymerized rosin, or the like. A hydrogenated product (a4) may be added. In particular, from the viewpoints of moisture resistance and moldability, it is preferable that the usage ratio of the resin (a4) is in the range of 3 to 50 mass% with respect to the total mass of the resin that forms the resin layer (A).

  Examples of petroleum resins include alicyclic petroleum resins obtained by polymerizing cyclopentadiene or its dimer, aromatic petroleum resins obtained by polymerizing C9 component, and the like. Examples of the terpene resin include a terpene-phenol resin obtained by polymerizing β-pinene. Examples of rosin resins include rosin resins such as gum rosin and wood rosin, and esterified rosin resins modified with glycerin, pentaerythritol, and the like. Specific examples include Alcon (trade name: manufactured by Arakawa Chemical Co., Ltd.), Clearon (trade name: manufactured by Yasuhara Chemical Co., Ltd.), and the like. These may be used alone or in combination of two or more.

  In addition, the film (I) used in the present invention may be a single layer film composed only of the resin layer (A), but from the viewpoint of cost reduction and the balance with rigidity, tearability and the like as described above. Thus, a multilayer film in which the resin layer (B) containing the polyolefin resin (b) as a main component is laminated on one side or both sides of the resin layer (A) may be used.

  As said polyolefin resin (b), the C2-C6 alpha-olefin homopolymer or copolymer is mentioned. The copolymerization type may be a block copolymer or a random copolymer.

  As resin which forms the resin layer (B) laminated | stacked on a resin layer (A), a polyethylene-type resin (b1) and / or a polypropylene-type resin (b2) are used from a compatible viewpoint with cyclic polyolefin resin (a1). It is preferable to use it. The resin layer (B) may be a single layer or a laminate of two or more layers.

  The polyethylene resin (b1) is the same as the above-mentioned polyethylene resin (a2), and preferred ones are also the same. The polypropylene resin (b2) is the same as the polypropylene resin (a3) described above, and preferable ones are also the same. A polyethylene resin (a2) and a polypropylene resin (a3) used together in the resin layer (A), a polyethylene resin (b1) and a polypropylene resin (b2) that can be preferably used as main components of the resin layer (B); May be the same or different.

  Furthermore, as the film (I) used in the present invention, the cyclic polyolefin resin (a1) is a main component on the resin layer (B) for the purpose of further providing moisture resistance or improving the moldability. The resin layer (A) to be laminated may have a multilayer structure such as (A) / (B) / (A), (B) / (A) / (B) / (A).

  In addition, when laminating with the thermoplastic resin sheet (II) described later, it may be bonded to the film (I) using an adhesive, but the adhesive application process / drying process can be eliminated. As a method excellent in productivity, it is preferable to perform thermal lamination. In order to maintain the interlayer strength between the film (I) and the sheet (II) by such a heat laminate, the film (I) includes a resin layer (A) mainly composed of the cyclic polyolefin resin (a1). In the multilayer film, the resin layer adjacent to the thermoplastic resin sheet (II) is preferably a resin layer (C) mainly composed of an acid-modified polyolefin having adhesiveness.

  The olefin component which is the main component of the acid-modified polyolefin is not particularly limited, but preferably an alkene having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 2-butene, 1-butene, 1-pentene, 1-hexene, Mixtures of these may be used. Among these, alkene having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene and 1-butene is more preferable, ethylene and propylene are further preferable, and ethylene is most preferable. Moreover, it is preferable that the acid-modified polyolefin contains a (meth) acrylic acid ester component. (Meth) acrylic acid ester components include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid Examples include octyl, decyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like. From the viewpoint of easy availability and adhesiveness, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and hexyl acrylate are more preferable, and methyl acrylate and ethyl acrylate are more preferable. The (meth) acrylic acid ester component may be copolymerized with the olefin component, and the form thereof is not limited. Examples of the copolymerization state include random copolymerization, block copolymerization, and graft copolymerization. (Graft modification) and the like. (In addition, "(meth) acrylic acid ~" means "acrylic acid ~ or methacrylic acid ~".) Specifically, as an ethylene- (meth) acrylic acid ester copolymer, for example, Elvalloy ( Product name: Mitsui-DuPont Polychemical Co., Ltd.), Aklift (trade name: Sumitomo Chemical Co., Ltd.), etc. These may be used alone or in combination of two or more.

  The acid-modified polyolefin may be one that has been acid-modified with an unsaturated carboxylic acid component. Examples of unsaturated carboxylic acid components include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like, as well as unsaturated dicarboxylic acid half esters and half amides. It is done. Of these, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and acrylic acid and maleic anhydride are particularly preferable. The unsaturated carboxylic acid component may be copolymerized with the olefin component, and the form thereof is not limited. Examples of the copolymerization state include random copolymerization, block copolymerization, and graft copolymerization (grafting). Modification). Specifically, examples of the ethylene-acrylic acid copolymer include Nucrel (trade name: Mitsui / DuPont Polychemical Co., Ltd.). Examples of the ethylene- (meth) acrylic acid ester-maleic anhydride copolymer include bondine (trade name: manufactured by Tokyo Materials Co., Ltd.). These may be used alone or in combination of two or more.

  Furthermore, as the acid-modified polyolefin, ethylene-vinyl acetate copolymer (EVA), or this EVA as a base resin, rosin, hydrogenated rosin, rosin ester derivative, polymerized rosin, terpene, modified terpene resin, aliphatic petroleum Modified EVA obtained by mixing and modifying one or more of resins and styrene resins is preferable, and modified EVA is particularly preferable. Specific examples of the modified EVA include modified polyethylene VMX manufactured by Mitsubishi Chemical Corporation and Mersen manufactured by Tosoh Corporation.

  These acid-modified polyolefins are variously selected from the viewpoint of compatibility with the thermoplastic resin sheet (II) to be thermally laminated, and may be used alone or in combination of two or more.

  The thickness of the film (I) used in the present invention is preferably in the range of 15 to 100 μm, particularly in the range of 20 to 90 μm, from the viewpoint of the balance between moisture resistance, laminate suitability, and secondary moldability. It is preferable. When the thickness of the film (I) is within this range, moisture resistance, stable vacuum formability / pressure forming characteristics, and further adhesive strength can be easily obtained.

  For each of the resin layers (A), (B), and (C), an antifogging agent, an antistatic agent, a thermal stabilizer, a nucleating agent, an antioxidant, a lubricant, an antiblocking agent, Components such as a release agent, an ultraviolet absorber, and a colorant can be added within a range that does not impair the object of the present invention. In particular, it is possible to make the content opaque or white due to the concealability of the contents and the print appearance characteristics. Further, when an adhesive or the like is used at the time of bonding with the sheet (II), the friction coefficient of the outermost resin layer to be bonded is preferably 1.5 or less, more preferably 1.0 or less. It is preferable to add a lubricant, an anti-blocking agent, and an antistatic agent to the resin layer corresponding to.

  Further, in the film (I) used in the present invention, the surface of the outermost resin layer bonded to the resin sheet (II) is treated so that the surface tension of the outermost surface is 38 mN / m or more, preferably 40 mN / m or more. It is preferable. Examples of such treatment methods include corona treatment, plasma treatment, chromic acid treatment, flame treatment, hot air treatment, surface oxidation treatment such as ozone / ultraviolet treatment, and surface unevenness treatment such as sandblasting. Corona treatment is preferable. By performing such a surface treatment, the coating property when applying the adhesive to the film (I) is improved, the adhesiveness with the adhesive and the like is excellent, and when the resulting multilayer sheet is secondarily formed It is easy to avoid problems such as peeling and twisting. In addition, even when heat laminating, interlayer adhesion can be ensured, and secondary molding processability is improved.

  Although it does not specifically limit as a manufacturing method of the film (I) used by this invention, For example, when setting it as a multilayer structure, the resin or resin mixture used for each resin layer is heat-melted with a respectively separate extruder, Examples thereof include a coextrusion method in which a desired multilayer structure is laminated in a molten state by a method such as a coextrusion multilayer die method or a feed block method, and then formed into a film by inflation, a T die / chill roll method, or the like. This coextrusion method is preferable because the thickness ratio of each layer can be adjusted relatively freely, and a multilayer film excellent in hygiene and cost performance can be obtained. Moreover, when a polyethylene-based resin and acid-modified polyethylene are used as the cyclic polyolefin resin (a1) used in the present invention, the resin layer (B), and the resin layer (C), the difference between the melting point and Tg between the two. In some cases, the film appearance may deteriorate during coextrusion processing, and it may be difficult to form a uniform layer structure. In order to suppress such deterioration, a T-die / chill roll method that can perform melt extrusion at a relatively high temperature is preferable.

  Since the film of the present invention can be obtained as a substantially unstretched film by the above-described production method, it is necessary to perform two processes such as deep drawing, embossing, foil pressing, etc. by vacuum forming after bonding to the thermoplastic sheet (II). Subsequent molding is also possible.

  The multilayer sheet of the present invention is obtained by laminating a film (I) having a resin layer (A) mainly composed of the above-mentioned cyclic polyolefin resin (a) and a thermoplastic resin sheet (II) of 300 μm or more. The sheet (II) is not particularly limited as long as it is made of a heat-moldable resin, but from the viewpoint of versatility and extrusion suitability, a sheet made of polyolefin resin such as polypropylene, polyethylene, polystyrene, or polyester resin. Is preferably used.

Further, the thickness is required to be 300 μm or more in order to form a rigid container, a container formed by deep drawing, or a tray, and a sheet of 500 μm or more and less than 5 mm is more preferable. Moreover, a foamed thermoplastic resin sheet is preferable from the viewpoint of lightness and heat insulation, and foamed polypropylene, foamed polyethylene, and foamed polystyrene are particularly preferable. As the foaming agent and foaming nucleating agent at the time of extrusion foaming, commonly used substances can be used. As the foaming agent, butane, heptane, chlorofluorocarbon, water or the like can be used. Butane is preferable from the viewpoint of easily obtaining a high expansion ratio. Moreover, talc etc. can be used as a foam nucleating agent. The extruded foam sheet using a polystyrene-based resin preferably has a thickness of 500 μm to 5.0 mm, and preferably has an apparent density of 50 g / L to 300 g / L from the balance between lightness and strength. it is preferred basis weight of ^{80g / m 2 ~300g / m 2} .

  The method for laminating the film (I) and the thermoplastic resin sheet (II) is not particularly limited. For example, a dry laminate, a wet laminate, a non-solvent laminate, or the like that is laminated by applying an adhesive. A method is mentioned. Moreover, it is also possible to form various layers of film (I) / thermoplastic resin sheet (II) by applying various lamination methods such as thermal lamination and extrusion lamination which are bonded by thermocompression bonding of a heating roll. Further, the thermoplastic resin sheet (II) can be laminated with the film (I) by the residual heat while extrusion molding.

  Examples of the adhesive used in the dry laminate include a polyether-polyurethane adhesive and a polyester-polyurethane adhesive.

  As a specific example of lamination by thermal lamination, when an impact-resistant polystyrene (HIPS) sheet or expanded polystyrene paper (PSP) is laminated with the film (I), the HIPS sheet or PSP side is heated with a heating roll, and this heating is performed. The HIPS sheet, PSP, and film (I) can be pressurized by the roll and the nip roll disposed on the film (I) side to thermally bond them together.

  The multilayer sheet of the present invention is secondarily molded and used as various packages. As a molding method, the multilayer sheet is heated and softened in a heating zone and then molded by a conventional method. As molding methods, vacuum molding, air pressure molding and their applications include rigid molding, free drawing molding, plug and rigid molding, matched molding, straight molding, air slip molding, drape molding, reverse draw molding, plug assist molding, Plug-assisted reverse draw molding or a combination of these methods can be employed.

  The application range of the multilayer sheet of the present invention is not particularly limited, and examples thereof include trays or containers used for foods, pharmaceuticals, industrial parts, miscellaneous goods, magazines, lids, etc., especially deep drawing. Can be suitably used as a packaging container. In particular, those using a foamed thermoplastic resin sheet can be suitably used as a container excellent in lightness, heat insulation, and volume reduction.

  Next, the present invention will be described in more detail with reference to examples and comparative examples.

Example 1
As a resin for the resin layer (A), a ring-opening polymer of a norbornene-based monomer [“Apel APL8008T” manufactured by Mitsui Chemicals, MFR: 15 g / 10 minutes (260 ° C., 21.18 N), glass transition temperature: 70 ° C .; Hereinafter, it is referred to as “COC (3)”. ] 90 parts by mass and linear medium density polyethylene [density: 0.930 g / cm ³ , melting point 125 ° C., MFR: 5 g / 10 min (190 ° C., 21.18 N); hereinafter referred to as “LMDPE”. 10 parts by mass of a resin mixture was used. These resins are supplied to a resin layer (A) extruder (40 mm in diameter) and melted at 200 to 230 ° C., and the molten resin is a co-extruded multilayer film manufacturing apparatus of T-die / chill roll method having a feed block. (Feed block and T die temperature: 250 ° C.) and melt extrusion was performed to obtain a film (I-1) having a film thickness of 20 μm. The surface of the resin layer (A) was subjected to corona treatment, and the surface tension with a wetting reagent was 40 mN / m.

On the corona-treated surface side of the obtained film (I-1), a urethane-based adhesive (1.5 mm, hereinafter referred to as “PSP”) is laminated after coating and drying the urethane-based adhesive to 2 g / m ^2. Then, a multilayer sheet was created.

Example 2
COC (3) was used as the resin for the resin layer (A). Further, as a resin for the resin layer (C) adjacent to the thermoplastic resin sheet (II), modified polyethylene having adhesiveness with polystyrene [VMX Z100F manufactured by Mitsubishi Chemical Corporation, density: 0.910 g / cm ³ , hereinafter referred to as “modified” PE ". ] Was used. These resins are respectively supplied to an extruder for a resin layer (A) (caliber 40 mm) and an extruder for a resin layer (C) (caliber 50 mm) and melted at 200 to 230 ° C., and the melted resin is fed into a block. Co-extrusion multilayer film production apparatus (feed block and T-die temperature: 250 ° C.) of T-die / chill roll method having co-extrusion and carrying out co-melt extrusion, and the layer structure of the film is (A) / (C) A co-extruded multilayer film (I-2) having a two-layer structure in which the thickness of each layer was 20 μm / 10 μm (total 30 μm) was obtained. The surface of the resin layer (C) was subjected to corona treatment, and the surface tension by the wetting reagent was 40 mN / m.

  On the corona-treated surface side of the obtained film (I-2), the PSP used in Example 1 was heat-laminated while being heated and pressed to prepare a multilayer sheet.

Example 3
As the resin for the resin layer (A-1), a resin mixture of 90 parts by mass of COC (3) and 10 parts by mass of LMDPE was used. Moreover, LMDPE was used as resin for resin layers (B). Further, a resin layer (A-2) using COC (3) was laminated on the resin layer (B). These resins are supplied to the respective extruders, and in the same manner as in Example 2, the film has a three-layer structure (A-1) / (B) / (A-2), and the thickness of each layer. Co-extruded multilayer film (I-3) having a thickness of 4 μm / 12 μm / 4 μm (total 20 μm) was obtained. The resin layer (A-1) was subjected to corona treatment, and the surface tension with the wetting reagent was 45 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-3) in the same manner as in Example 1 to prepare a multilayer sheet.

Example 4
As the resin for the resin layer (A-1), a resin mixture of 90 parts by mass of COC (3) and 10 parts by mass of LMDPE was used. LMDPE was used as the resin for the resin layer (B). Further, on the resin layer (B), 80 parts by mass of COC (3) and a norbornene-based monomer ring-opening polymer [“Appel AP6013T” manufactured by Mitsui Chemicals, Inc., MFR: 15 g / 10 min (260 ° C., 21.18 N) Glass transition temperature: 125 ° C .; hereinafter referred to as “COC (2)”. ] A resin layer (A-2) using 20 parts by mass of a resin mixture was laminated. These resins are supplied to the respective extruders, and in the same manner as in Example 3, the film has a three-layer structure (A-1) / (B) / (A-2), and the thickness of each layer. Coextruded multilayer film (I-4) having a thickness of 4 μm / 12 μm / 4 μm (total 20 μm) was obtained. The surface of the resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 45 mN / m.

After applying the urethane adhesive to 2 g / m ² on the corona-treated surface side of the obtained film (I-4), a polystyrene film (25 μm) is laminated, and the PSP is further heat-pressed while heating. Thermal lamination was performed to create a multilayer sheet.

Example 5
As a resin for the resin layers (A-1) and (A-2), 90 parts by mass of COC (3) and a norbornene-based monomer ring-opening polymer [“Apel APL6015T” manufactured by Mitsui Chemicals, MFR: 10 g / 10 min. (260 ° C., 21.18 N), glass transition temperature: 145 ° C .; hereinafter referred to as “COC (1)”. 10 parts by mass of a resin mixture was used. Moreover, 90 mass parts of LMDPE and 10 mass parts of COC (3) were used as resin for resin layers (B). In the same manner as in Example 3 so that the layer structure of the film is (A-1) / (B) / (A-2), and the thickness of each layer is 5 μm / 40 μm / 5 μm (total 50 μm). Thus, a coextruded multilayer film (I-5) was obtained. The surface of the resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 45 mN / m.

On the corona-treated surface side of the obtained film (I-5), in the same manner as in Example 1, after applying and drying a urethane adhesive to 2 g / m ² , PSP (2.0 mm) was laminated. A multilayer sheet was created.

Example 6
COC (3) was used as the resin for the resin layers (A-1) and (A-2). As a resin for the resin layer (B), linear low density polyethylene [density: 0.900 g / cm ³ , melting point 85 ° C., MFR: 5 g / 10 minutes (190 ° C., 21.18 N); hereinafter, “LLDPE” That's it. A resin mixture of 90 parts by mass and 10 parts by mass of COC (3) was used. A coextruded multilayer film (I-6) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 15 μm / 40 μm / 15 μm (total 70 μm). The surface of the resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 45 mN / m.

  PSP (2 mm) was laminated on the corona-treated surface side of the obtained film (I-6) in the same manner as in Example 5 to prepare a multilayer sheet.

Example 7
As the resin for the resin layers (A-1) and (A-2), a resin mixture of 20 parts by mass of COC (2) and 80 parts by mass of COC (3) was used. LMDPE was used as the resin layer (B). A coextruded multilayer film (I-7) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 25 μm / 50 μm / 25 μm (total 100 μm). The surface of the resin layer (A-1) was subjected to corona treatment, and the surface tension with the wetting reagent was 43 mN / m.

After coating and drying the urethane adhesive to 2 g / m ² on the corona-treated surface side of the obtained film (I-7), a high impact polystyrene sheet (HIPS, 800 μm) is laminated, and a multilayer sheet is obtained. Created.

Example 8
A resin mixture of 70 parts by mass of COC (1) and 30 parts by mass of COC (3) as the resin for the resin layer (A-2), and propylene-α polymerized using a metallocene catalyst as the resin for the resin layer (B) -Olefin random copolymer [Density: 0.900 g / cm ³ , Melting point 135 ° C., MFR: 4 g / 10 min (230 ° C., 21.18 N)]; hereinafter referred to as “MRCP”. ) Was used. COC (3) was used for the resin layer (A-1). A coextruded multilayer film (I-8) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 10 μm / 30 μm / 10 μm (total 50 μm). The surface of the resin layer (A-1) was subjected to corona treatment, and the surface tension with the wetting reagent was 43 mN / m.

On the corona-treated surface side of the obtained film (A-8), in the same manner as in Example 1, after applying and drying a urethane adhesive to 2 g / m ² , PSP (1.5 mm) was laminated. A multilayer sheet was created.

Example 9
COC (1) was used as the resin for the resin layer (A-2), and COC (3) was used as the resin for the inner resin layer (A-1). LLDPE was used as the resin for the resin layer (B). A coextruded multilayer film (I-9) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 5 μm / 40 μm / 5 μm (total 50 μm). The surface of the resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 45 mN / m.

On the corona-treated surface side of the obtained film (I-9), in the same manner as in Example 1, after applying and drying a urethane adhesive to 2 g / m ² , PSP is laminated to create a multilayer sheet. did.

Example 10
As the resin for the resin layers (A-1) and (A-2), a resin mixture of 20 parts by mass of COC (1), 40 parts by mass of COC (2), and 40 parts by mass of COC (3) was used. Moreover, LLDPE was used as resin for the resin layer (B). A coextruded multilayer film (I-10) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 16 μm / 18 μm / 16 μm (total 50 μm). The resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 43 mN / m.

On the corona-treated surface side of the obtained film (A-10), in the same manner as in Example 1, after applying and drying a urethane-based adhesive to 2 g / m ² , PSP is laminated to create a multilayer sheet. did.

Example 11
As a resin for the resin layer (A-2) on the surface, 70 parts by mass of COC (2) and high-density polyethylene [density: 0.960 g / cm ³ , melting point 128 ° C., MFR: 10 g / 10 minutes (190 ° C., 21. 18N); hereinafter referred to as “HDPE”. 30 parts by mass of a resin mixture was used. Moreover, LLDPE was used as resin for the resin layer (B). As the resin for the inner resin layer (A-1), a resin mixture of 50 parts by mass of COC (1) and 50 parts by mass of COC (3) was used. Further, as the resin for the resin layer (C) adjacent to the thermoplastic resin sheet (II), the modified PE having adhesiveness with PS used in Example 2 was used. The layer structure of the film is a four-layer structure of (A-2) / (B) / (A-1) / (C), and the thickness of each layer of the film is 18 μm / 24 μm / 18 μm / 10 μm (total 70 μm). In the same manner as in Example 3, a coextruded multilayer film (I-11) was obtained. The resin layer (C) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  The resulting film (I-11) was heat laminated to the resin layer (C) surface side of PSP (1.5 mm) while heating, thereby producing a multilayer sheet.

Example 12
COC (3) was used as the resin for the resin layers (A-1) and (A-2) on the surface. As the resin for the resin layer (B), a resin mixture of 50 parts by mass of LMDPE and 50 parts by mass of MRCP was used. Further, as a resin for the resin layer (C) to be laminated on the inner resin layer (A-1), an acid-modified polyolefin adhesive resin (Plexer PX5400: manufactured by Rio Del Basel) was used. A coextruded multilayer film (I-12) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 18 μm / 40 μm / 18 μm / 14 μm (total 90 μm). The surface of the resin layer (C) was subjected to corona treatment, and the surface tension with a wetting reagent was 40 mN / m.

  Polystyrene (HIPS: GH8300-5 manufactured by DIC Corporation) resin is supplied to an extruder (40 mm diameter) on the resin layer (C) side of the obtained film (I-12) and melted at 200 to 230 ° C. Then, the molten resin is supplied to a T die / chill roll sheet manufacturing apparatus (feed block and T die temperature: 220 ° C.) having a feed block, melt extrusion is performed, and a sheet having a thickness of 600 μm is stuck while being extruded. Thermal lamination was performed to create a multilayer sheet.

Example 13
As the resin for the resin layers (A-1) and (A-2), a resin mixture of 50 parts by mass of COC (1) and 50 parts by mass of COC (3) was used. LMDPE was used as the resin for the resin layer (B). Further, modified PE was used as the resin for the resin layer (C) to be laminated on the inner resin layer (A-1). A coextruded multilayer film (I-13) was obtained in the same manner as in Example 3 so that the thickness of each layer of the film was 20 μm / 50 μm / 20 μm / 10 μm (total 100 μm). The surface of the resin layer (C) was subjected to corona treatment, and the surface tension with a wetting reagent was 40 mN / m.

  A polyethylene sheet (1 mm, hereinafter referred to as PE) was heated and laminated on the resin layer (C) surface side of the obtained film (I-13) to prepare a multilayer sheet.

Example 14
As the resin for the resin layer (A), a resin mixture of 80 parts by mass of COC (3) and 20 parts by mass of HDPE was used. A film (I-14) was obtained in the same manner as in Example 1 so that the thickness of the film was 20 μm. The resin layer (A) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-14) in the same manner as in Example 1 to prepare a multilayer sheet.

Example 15
As the resin for the resin layer (A), a resin mixture of 80 parts by mass of COC (3) and 20 parts by mass of HDPE was used. Further, modified PE was used as the resin for the resin layer (C). These resins were supplied to the respective extruders, and in the same manner as in Example 2, the layer structure of the film was a two-layer structure of (A) / (C), and the thickness of each layer was 20 μm / 10 μm (total 30 μm). A coextruded multilayer film (I-15) was obtained. The resin layer (C) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  PSP was heat laminated while heating on the corona-treated surface side of the obtained film (I-15) in the same manner as in Example 2 to prepare a multilayer sheet.

Example 16
A resin mixture of 80 parts by mass of COC (3) and 20 parts by mass of HDPE was used for the resin layer (A-1) and the resin layer (A-2). In addition, MRCP was used as the resin for the resin layer (B). These resins are supplied to the respective extruders, and in the same manner as in Example 3, the layer structure of the film is a three-layer structure of (A-1) / (B) / (A-2). A coextruded multilayer film (I-16) having a thickness of 10 μm / 10 μm / 10 μm (total 30 μm) was obtained. The resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 43 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-16) in the same manner as in Example 1 to prepare a multilayer sheet.

Example 17
After applying the urethane adhesive to 2 g / m ² on the corona-treated surface side of the film (I-16) obtained in Example 16, a polystyrene film (25 μm) is laminated, and the PSP is further heated. Then, a heat-laminated sheet that was thermocompression bonded was carried out to produce a multilayer sheet.

Example 18
As a resin for the resin layer (A), a resin mixture of 80 parts by mass of COC (3) and 20 parts by mass of a petroleum resin (“Arcon P-125” softening point 125 ° C. manufactured by Arakawa Chemical Industries) was used. A film (I-17) was obtained in the same manner as in Example 1 so that the thickness of the film was 20 μm. The resin layer (A) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-17) in the same manner as in Example 1 to prepare a multilayer sheet.

Example 19
As the resin for the resin layer (A), a resin mixture of 80 parts of COC (3) and 20 parts of petroleum resin was used. Further, modified PE was used as the resin for the resin layer (C). These resins were supplied to the respective extruders, and in the same manner as in Example 2, the layer structure of the film was a two-layer structure of (A) / (C), and the thickness of each layer was 20 μm / 10 μm (total 30 μm). A coextruded multilayer film (I-18) was obtained. The resin layer (C) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  PSP was heat laminated while heating on the corona-treated surface side of the obtained film (I-18) in the same manner as in Example 2 to prepare a multilayer sheet.

Example 20
For the resin layer (A-1) and the resin layer (A-2), a resin mixture of 80 parts by mass of COC (3) and 20 parts by mass of petroleum resin was used. In addition, MRCP was used as the resin for the resin layer (B). These resins are supplied to the respective extruders, and in the same manner as in Example 3, the layer structure of the film is a three-layer structure of (A-1) / (B) / (A-2). A coextruded multilayer film (I-19) having a thickness of 10 μm / 10 μm / 10 μm (total 30 μm) was obtained. The resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 43 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-19) in the same manner as in Example 1 to prepare a multilayer sheet.

Example 21
As the resin for the resin layer (A), a resin mixture of 70 parts by mass of COC (3), 20 parts by mass of HDPE, and 10 parts by mass of petroleum resin was used. A film (I-20) was obtained in the same manner as in Example 1 so that the thickness of the film was 20 μm. The resin layer (A) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-20) in the same manner as in Example 1 to prepare a multilayer sheet.

Example 22
As the resin for the resin layer (A), a resin mixture of 70 mass parts of COC (3), 20 mass parts of HDPE, and 10 mass parts of petroleum resin was used. Further, modified PE was used as the resin for the resin layer (C). These resins were supplied to the respective extruders, and in the same manner as in Example 2, the layer structure of the film was a two-layer structure of (A) / (C), and the thickness of each layer was 20 μm / 10 μm (total 30 μm). Coextruded multilayer film (I-21) was obtained. The resin layer (C) was subjected to corona treatment, and the surface tension by the wetting reagent was 43 mN / m.

  A multilayer sheet was prepared by heating and laminating PSP on the corona-treated surface side of the obtained film (I-21) while heating PSP in the same manner as in Example 2.

Example 23
A resin mixture of 70 parts by mass of COC (3), 20 parts by mass of HDPE, and 10 parts by mass of petroleum resin was used for the resin layer (A-1) and the resin layer (A-2). In addition, MRCP was used as the resin for the resin layer (B). These resins are supplied to the respective extruders, and in the same manner as in Example 3, the layer structure of the film is a three-layer structure of (A-1) / (B) / (A-2). A coextruded multilayer film (I-22) having a thickness of 10 μm / 10 μm / 10 μm (total 30 μm) was obtained. The resin layer (A-1) was subjected to corona treatment, and the surface tension with a wetting reagent was 43 mN / m.

  PSP was laminated on the corona-treated surface side of the obtained film (I-22) in the same manner as in Example 1 to prepare a multilayer sheet.

Comparative Example 1
PSP (2 mm) was used alone and evaluated.

Comparative Example 2
The HIPS sheet prepared in Example 12 before heat lamination was used alone and evaluated.

Comparative Example 3
PSP (2 mm) was laminated on the corona-treated surface side of a biaxially stretched polypropylene film (OPP: FOR 20 μm manufactured by Futamura Chemical Co., Ltd.) to prepare a multilayer sheet.

  Using the multilayer sheets obtained in Examples 1 to 22 and Comparative Examples 1 to 3, the following tests and evaluations were performed.

Secondary formability The sheet obtained above was attached to a container molding die having a circular shape with an opening shape of 150 mmφ, a bottom shape of 50 mmφ, and a depth of 80 mm, using a hot plate heating type pneumatic molding machine. Molding was performed such that the thermoplastic resin film surface was on the outside of the container. This molding test was carried out under the optimum conditions for each sheet at a hot plate temperature of 120 to 150 ° C., a heating time of 2.0 seconds, a heating pressure of 0.1 MPa, and a molding time of 1.0 to 3.0 seconds. The appearance of the obtained molded body was visually confirmed. The result of this visual confirmation was defined as secondary formability.

  The shape of the mold of the molded body is clearly shown, and the film (I) that is not torn or cracked and that the laminated film is not peeled is judged as good and is indicated as “O”, and the mold of the molded body The case where the shape did not appear clearly, the case where there was tearing or peeling of the laminated film was judged as defective and indicated as “x”.

Moisture proofing 30 g of calcium chloride is put into the molded body (container) obtained above, and the upper part is sealed with 30 μm of aluminum foil with an epoxy resin two-component adhesive, and then placed in a constant temperature and humidity chamber at 40 ° C. and 90% humidity. The change in the weight of the container was measured and the moisture resistance was evaluated.
◎: 3 g / container, 15 days or less ○: 5 g / container, 15 days or less ×: 5 g / container, 15 days or less

  The results obtained above are shown in Tables 1-3.

Claims (7)

A film (I) having a resin layer (A) mainly composed of a cyclic polyolefin resin (a1) and a resin layer (B) mainly composed of a polyolefin resin (b), and a thermoplastic resin sheet (II) And the thickness of the film (I) is 15 to 100 μm, the thickness of the thermoplastic resin sheet (II) is 300 μm or more,
The layer structure of the film (I) is such that the resin layer (A) and the resin layer (B) are (A) / (B) / (A) or (B) / (A) / (B) / (A) is a multilayer structure,
The resin layer (A) further contains a polyethylene resin (a2), and the polyethylene resin (a2) is high-density polyethylene,
The multilayer sheet for secondary molding, wherein the thermoplastic resin sheet (II) is expanded polypropylene, expanded polyethylene, or expanded polystyrene.   The multilayer sheet for secondary molding according to claim 1, wherein the cyclic polyolefin resin (a1) is a norbornene polymer. At least one layer of the resin layer (A) further contains at least one resin (a4) selected from the group consisting of petroleum resins, coumarone-indene resins, terpene resins, rosin resins, and hydrogenated products thereof. The multilayer sheet for secondary molding according to claim 1 or 2 . The multilayer sheet for secondary molding according to claim 3 , wherein a use ratio of the resin (a4) is in a range of 3 to 50 mass% with respect to a total mass of the resin forming the resin layer (A). The multilayer sheet for secondary molding according to any one of claims 1 to 4, wherein the polyolefin resin (b) is a propylene-α-olefin random copolymer polymerized using a metallocene catalyst . The film (I) is a multilayer film including a resin layer (A) mainly composed of a cyclic polyolefin resin (a1), and the resin layer adjacent to the thermoplastic resin sheet (II) is mainly composed of an acid-modified polyolefin. The multilayer sheet for secondary molding according to any one of claims 1 to 5, which is a resin layer (C) as a component. A deep-drawn molded container using the multilayer sheet for secondary molding according to any one of claims 1 to 6 .