WO2017221375A1 - Multilayer resin sheet and shaped container - Google Patents

Multilayer resin sheet and shaped container Download PDF

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Publication number
WO2017221375A1
WO2017221375A1 PCT/JP2016/068681 JP2016068681W WO2017221375A1 WO 2017221375 A1 WO2017221375 A1 WO 2017221375A1 JP 2016068681 W JP2016068681 W JP 2016068681W WO 2017221375 A1 WO2017221375 A1 WO 2017221375A1
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Prior art keywords
layer
resin
sheet
resin layer
thickness
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PCT/JP2016/068681
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French (fr)
Japanese (ja)
Inventor
徳永　久次
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デンカ株式会社
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Priority to JP2018523231A priority Critical patent/JP6800972B2/en
Priority to PCT/JP2016/068681 priority patent/WO2017221375A1/en
Publication of WO2017221375A1 publication Critical patent/WO2017221375A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins

Definitions

  • the present invention relates to a multilayer resin sheet having high barrier properties and a container formed by thermoforming it.
  • polystyrene resins having excellent thermoformability and rigidity have been used as containers for soft drinks, fruit juice drinks, and favorite foods and drinks.
  • a polystyrene resin layer is used as the outermost layer, and an ethylene-vinyl alcohol copolymer resin layer is provided in the middle through an adhesive layer such as a modified polyolefin resin to provide oxygen barrier properties.
  • Multilayer resin sheets that suppress deterioration in quality and multilayer containers comprising the same have become widespread (see Patent Document 1).
  • a gas barrier material containing a silicon-containing polymer and a thermoplastic resin is used, the glass transition temperature of the thermoplastic resin is set to a value of 100 ° C. or higher, and plasma ion implantation is performed for the gas barrier material.
  • the silicon-containing polymer is a polysilazane compound
  • the thermoplastic resin is at least one selected from the group consisting of a polycarbonate resin, a cyclopolyolefin resin, and a polysulfone resin.
  • Patent Document 3 Furthermore, an optical resin sheet having barrier properties and solvent resistance against gases such as oxygen and water vapor and moisture has been proposed (see Patent Document 3).
  • the thickness is determined by performing heat curing treatment on the coating film.
  • a gas barrier layer having a thickness of 0.02 to 5 ⁇ m is provided.
  • Patent Document 4 discloses a fragrance-holding resin layer made of a mixture of a terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol terpolymer resin and a polybutylene terephthalate resin, and an impact resistance made of a polyamide resin.
  • a composite sheet in which an application layer, a water vapor barrier resin layer, a gas barrier resin layer, and a thermoplastic support resin layer are sequentially laminated.
  • Patent Document 5 a polypropylene resin is laminated on one side of a barrier resin layer, and the total thickness of the polypropylene resin layer is 10 to 40% of the total thickness of the sheet. Sheets having excellent properties (particularly oxygen barrier properties), moldability, and mechanical properties such as rigidity and strength have been proposed.
  • Patent Document 5 an oil-resistant polypropylene resin is formed on the outermost surface of a sheet, and a resin composition layer composed of a styrene resin, a styrene-diene copolymer and an olefin resin is formed as a support layer.
  • a sheet configuration has been proposed. However, by laminating a crystalline polypropylene resin and an amorphous styrene resin, warping is likely to occur after container molding, resulting in problems such as poor sealing with the lid material and poor appearance as a container. There is a possibility.
  • Patent Documents 1 to 5 mainly describe the characteristics of blocking components that affect the contents of the container such as oxygen and water vapor. However, it is not configured to cover additional performance such as the above-described oil resistance and warpage affecting the appearance and functionality of the container.
  • the present invention has been made in view of the above circumstances, and has a high barrier property multilayer resin that has excellent thermoformability, oxygen barrier property, water vapor barrier property, and oil resistance, and suppresses warpage after the sheet and thermoforming.
  • An object is to provide a sheet and a molded container formed by molding the sheet.
  • the present inventor has intensively studied for the purpose of having the above characteristics, and as a result, is a multilayer resin sheet formed by laminating a plurality of resin layers, and a polyolefin-based resin layer serving as a skin layer and an adhesive Layer, an oxygen-barrier resin layer, and a resin layer including a polystyrene-based resin layer serving as an undercoat layer.
  • the thickness of the entire sheet is 200 to 1300 ⁇ m
  • the thickness of the polyolefin-based resin layer is the thickness of the entire sheet.
  • the polyolefin resin layer is formed of a block polypropylene resin.
  • the block polypropylene resin refers to one in which a homopropylene block is a continuous phase and ethylene propylene rubber (EPR) forms a dispersion layer.
  • EPR ethylene propylene rubber
  • the thickness of the polyolefin-based resin layer is 5% or more and less than 10% with respect to the thickness of the entire sheet.
  • the thickness of the oxygen barrier resin layer is preferably 10 to 50 ⁇ m, and the oxygen permeability is preferably 10 cc / m 2 ⁇ day or less.
  • transmittance of the multilayer resin sheet comprised as mentioned above is 10 g / m ⁇ 2 > * day or less.
  • the present invention provides a molded container obtained by thermoforming the multilayer resin sheet configured as described above so that the polyolefin resin layer is positioned on the inner surface of the container.
  • the multilayer resin sheet configured as described above and a molded container formed by molding the same have excellent thermoformability, oxygen barrier property, water vapor barrier property, oil resistance, and warp after the sheet and thermoforming. Can be suppressed.
  • an oxygen barrier resin layer 12 is laminated with a polyolefin-based resin layer 10 serving as a skin layer on the outermost surface through an adhesive layer 11a.
  • a polystyrene resin layer is laminated on the opposite side through the adhesive layer 11b.
  • the thickness of the entire sheet is 200 to 1300 ⁇ m, and the thickness of the polyolefin resin layer is set to 1 to 30% of the layer composition ratio with respect to the thickness of the entire sheet. More preferably, the thickness of the polyolefin resin layer is 2% or more and less than 10% with respect to the thickness of the entire sheet. More preferably, the thickness of the polyolefin resin layer is 5% or more and less than 10% with respect to the thickness of the entire sheet.
  • the multilayer resin sheet according to an embodiment of the present invention has a layer structure of polyolefin resin layer / adhesive layer / oxygen barrier resin layer / adhesive layer / polystyrene resin layer, and is simply a skin layer / adhesive layer / The notation is oxygen barrier layer / adhesive layer / undercoat layer.
  • the lower skin layer is a layer that is finely pulverized or re-pelletized after heat melting and returned as a recycled product without discarding the part called scrap generated in the process of producing the multilayer resin sheet or molded container of the present invention. It is good also as a structure which provided newly.
  • a configuration may be adopted in which a printing surface is provided by a method such as direct printing or laminating printed films.
  • the thickness of the entire sheet in the present invention is preferably 200 to 1300 ⁇ m. If the thickness of the container after thermoforming is less than 200 ⁇ m, a thin portion of the container is formed, and the content of the container on the inner surface of the container is reduced due to a decrease in container strength representing resistance to compression and pressure called buckling strength. There is a possibility that deformation or breakage of the container may occur due to vibration or compression when the object is stored and transported. When it exceeds 1300 ⁇ m, heat is not sufficiently transmitted in the thickness direction of the sheet during thermoforming, and molding defects may occur.
  • the container is allowed to stand on a smooth surface with the flange portion of the molded container at the bottom, and deformation is confirmed by placing a weight with a constant load on the bottom surface of the container.
  • a method of measuring a load that deforms a container using a device called a push-pull gauge that measures a load applied to tension or compression is not limited to this, and is evaluated by a suitable method. Can do.
  • the film forming method of the multilayer resin sheet of the present embodiment is not particularly limited, and a general film forming method can be used.
  • a coextrusion method in which each raw resin is melt-extruded using four or more single-screw or twin-screw extruders, and a multilayer resin sheet is obtained by a feed block and a T-die incorporating a selector plug, or a multi-manifold
  • dye is mentioned.
  • the polyolefin-based resin layer 10 preferably has a layer composition ratio of 1 to 30% with respect to the thickness of the entire sheet. More preferably, the layer composition ratio is 2% or more and less than 10%. More preferably, the layer composition ratio is 5% or more and less than 10%.
  • the layer composition ratio described here is calculated as a percentage from a value obtained by dividing the thickness of the polyolefin resin layer by the thickness of the entire sheet. When the layer composition ratio with respect to the entire sheet is less than 1%, particularly when the entire sheet thickness is thin, a sufficient thickness as a polyolefin-based resin layer cannot be secured, and functions such as water vapor barrier properties may not be exhibited.
  • the crystalline polyolefin resin layer that forms the skin layer tends to increase in heat shrinkage during thermoforming, whereas the non-crystalline polystyrene resin that forms the lower skin layer. Since the heat shrinkage of the layer is small, a difference in the heat shrinkage rate between the skin layer and the lower skin layer may cause warpage of the sheet or the container after thermoforming.
  • the skin layer 10 composed of the polyolefin-based resin described in the present invention is basically located on the inner surface (the surface in contact with the contents) of a container formed by thermoforming a sheet. It is formed for the purpose of imparting oil resistance. Moreover, it is preferable to provide a heat resistance by selecting a resin that can withstand a hot water temperature of 90 ° C. or higher for a container into which hot water is poured.
  • the multilayer resin sheet configured as described above preferably has a water vapor transmission rate of 10 g / m 2 ⁇ day or less, and more preferably 5 g / m 2 ⁇ day or less. If it exceeds 10 g / m 2 ⁇ day, there is a possibility that a sufficient suppression function will not be exhibited when the contents of the thermoformed container are altered or discolored due to the permeation of moisture.
  • polyolefin resin in the constitution of the present invention examples include, but are not limited to, a homopolymer of a polyolefin having about 2 to 8 carbon atoms such as ethylene, propylene and butene-1.
  • polyethylene resin high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and the like that are commonly used can be applied.
  • polypropylene resin any of homopolymer, random copolymer and block copolymer can be applied.
  • block copolymer is particularly preferably used.
  • the block copolymer has a viscosity (Pa ⁇ s) at a measurement temperature of 190 ° C., a shear rate of 100 to 300 (1 / sec) of 50,000 to 1,000,000, and a viscosity change at 190 to 230 ° C. of 0.5 to 15 Pa ⁇ . More preferably, a resin having a range of s / ° C. is used.
  • the polyolefin resin to be used can be appropriately blended to such an extent that the appearance of the sheet and the container after thermoforming is not impaired.
  • Typical examples of the oxygen barrier resin constituting the oxygen barrier resin layer 12 of the present embodiment include ethylene-vinyl alcohol copolymer resin, polyamide resin, polyvinyl alcohol, and polyvinylidene chloride. It is not limited to these. Among these, ethylene-vinyl alcohol copolymer resin is preferable in terms of extrusion moldability.
  • the ethylene-vinyl alcohol copolymer resin is usually obtained by saponifying an ethylene-vinyl acetate copolymer, and has an ethylene content of 10 to 65 mol in order to provide oxygen barrier properties and extrusion moldability. %, Preferably 20 to 50 mol%, and a saponification degree of 90% or more, preferably 95% or more.
  • polyamide resin examples include lactam polymers such as caprolactam and laurolactam, polymers of aminocarboxylic acids such as 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, hexamethylenediamine, decamethylenediamine, Aliphatic diamines such as dodecamethylenediamine, 2,2,4- or 2,4,4-trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane) ), Alicyclic diamines such as m- or p-xylylenediamine, diamine units such as aromatic diamines, aliphatic dicarboxylic acids such as adipic acid, suberic acid and sebacic acid, and alicyclics such as cyclohexanedicarboxylic acid Aromatic dicarboxylic acid, terephthalate
  • polyamide resin examples include nylon 6, nylon 9, nylon 11, nylon 12, nylon 66, nylon 610, nylon 611, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6/66, nylon 6 / 610, nylon 6 / 6T, nylon 6I / 6T, etc., among which nylon 6 and nylon MXD6 are preferred.
  • the thickness of the oxygen barrier resin layer 12 is preferably 10 to 50 ⁇ m, more preferably 20 to 40 ⁇ m. If the thickness is less than 10 ⁇ m, the thickness of the oxygen barrier resin layer in the container after thermoforming the sheet becomes extremely thin, so that the oxygen contained in the container can be prevented from deterioration due to oxidative degradation. There is a possibility that the barrier performance cannot be obtained, and when it exceeds 50 ⁇ m, there is a possibility that a so-called appearance defect called “hibari burr” occurs at the time of punching of the container applied after thermoforming.
  • the oxygen permeability of the oxygen barrier resin layer 12 is preferably 10 cc / m 2 ⁇ day or less, and more preferably 5 cc / m 2 ⁇ day or less. When it exceeds 10 cc / m 2 ⁇ day, there is a possibility that a sufficient suppression function is not exhibited when the contents of the thermoformed container are subject to oxidative degradation.
  • a modified polyolefin polymer is preferable.
  • the modified polyolefin polymer constituting the adhesive layer include homopolymers of polyolefins having about 2 to 8 carbon atoms such as ethylene, propylene and butene-1, and these polyolefins and ethylene, propylene, butene-1, 3-methylbutene.
  • polystyrene resins such as copolymers with vinyl compounds such as acrylic acid esters, methacrylic acid esters, polystyrene, ethylene-propylene copolymers, ethylene-propylene-diene copolymers, ethylene-butene-1 copolymers, Polyolefin rubber such as propylene-butene-1 copolymer is used for acrylic acid, Unsaturated carboxylic acids such as rillic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, or derivatives thereof such as acid halides, amides, imides, anhydrides, esters, and other polyolefins having about 2 to 20 carbon atoms, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, Polyolefin resins such as copolymers with vinyl compounds such as acrylic acid esters, methacrylic acid esters, poly
  • maleyl chloride maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like can be cited as representative examples.
  • modified polyolefin polymer among them, an ethylene resin, a propylene resin, or an ethylene-propylene or butene-1 copolymer rubber modified with an unsaturated dicarboxylic acid or an anhydride thereof, particularly maleic acid or an anhydride thereof is preferable. It is.
  • the thickness of the adhesive layer is preferably 5 to 50 ⁇ m, more preferably 10 to 30 ⁇ m in any layer. If the thickness is less than 5 ⁇ m, sufficient adhesion strength between layers may not be obtained. If the thickness exceeds 50 ⁇ m, an appearance defect called so-called whirling may occur at the time of punching a container applied after thermoforming. There is sex.
  • the polystyrene resin constituting the polystyrene resin layer 13 of the present embodiment includes polystyrene monomers such as polystyrene, ⁇ -methyl polystyrene, p-methyl polystyrene, dimethyl polystyrene, pt-butyl polystyrene, chloropolystyrene.
  • HIPS resin high impact polypolystyrene
  • ABS resin polystyrene-acrylonitrile Rugurafuto polymer
  • Polystyrene (GPPS resin) and high-impact polypolystyrene (HIPS resin) are preferable from the viewpoint of the rigidity and moldability of the molded container, and the blend ratio can be adjusted as appropriate. It can be used by blending.
  • the polystyrene resin preferably contains 4 to 8% by mass of a butadiene rubber component.
  • the butadiene rubber component content is a simple method of adjusting by blending GPPS and HIPS, but it may be adjusted at the manufacturing stage of HIPS. If it is less than 4% by mass, there is a possibility that practically sufficient container strength may not be obtained, and if it exceeds 8% by mass, there is a possibility of causing problems such as adhesion of a hot plate, particularly during thermoforming using a hot platen. .
  • the polystyrene resin layer 13 may have a colorant such as a pigment or a dye, a release agent such as silicon oil or an alkyl ester, or a fiber such as glass fiber as long as the effect of the present invention is not impaired.
  • a colorant such as a pigment or a dye, a release agent such as silicon oil or an alkyl ester, or a fiber such as glass fiber as long as the effect of the present invention is not impaired.
  • Additives such as reinforcing agents, granular lubricants such as talc, clay, silica, salt compounds of sulfonic acid and alkali metals, antistatic agents such as polyalkylene glycol, UV absorbers, and antibacterial agents can be added .
  • the thickness of the polystyrene resin layer 13 of this embodiment is preferably 200 to 900 ⁇ m, more preferably 300 to 700 ⁇ m. If it is less than 200 ⁇ m, the thickness of each part of the container after molding may not be more uniform, and there is a possibility that excellent thermoformability may not be expressed. If it exceeds 900 ⁇ m, in the thickness direction of the sheet during thermoforming Heat may not be sufficiently transmitted, and molding defects may occur.
  • FIG. 3 shows an example of the molded container of the present invention.
  • the molded container of the present invention is obtained by thermoforming the multilayer resin sheet of the present invention.
  • Thermoforming methods include general vacuum forming, pressure forming, and plug assist method in which plugs are formed by contacting a plug on one side of the sheet, and male and female molds that form a pair on both sides of the sheet. Examples of the method include so-called match mold molding, which is performed by bringing them into contact with each other, but is not limited thereto.
  • a known sheet heating method such as radiant heating by an infrared heater or the like which is non-contact heating, or hot plate heating to soften the sheet by directly touching the heated hot plate is applied. can do.
  • the molding temperature at the time of thermoforming is appropriately set in consideration of the melting point of the resin, etc., but if the sheet heating temperature is too low, the molded state of the container after thermoforming is insufficient, and conversely the sheet heating If the temperature is too high, there is a risk that a defect such as a fusing to the hot platen may occur, so it is preferable to set the temperature appropriately.
  • the resin raw materials used in the examples are as follows.
  • Polyolefin-based resin layer PP resin “3080” (Formosa Polypropylene Co., Ltd., MI: 8.5 g / 10 min. (190 ° C., 2.16 kgf), Block-PP)
  • Adhesive layer Modified polyolefin polymer modified PO
  • Modic F502C Mitsubishi Chemical Corporation, MI: 1.3 g / 10 min. (190 ° C., 2.16 kgf)
  • Polystyrene resin layer HIPS resin “4241” (Total Petrochemicals, MI: 4.0 g / 10 min. (200 ° C, 5.0 kgf))
  • the multilayer resin sheet was thermoformed under the following conditions to obtain a container shown in FIG.
  • Equipment used Vacuum pressure forming machine manufactured by Asano Laboratories Heating heater: Non-contact far infrared heater Sheet surface temperature: Adjust sheet surface temperature as appropriate according to the sheet configuration
  • various evaluations of multilayer resin sheets and containers are performed by the following methods. It was. The results are shown in Table 1.
  • PP resin was used as polyolefin resin by a feed block method.
  • the water vapor transmission rate of the multilayer resin sheet obtained as described above is 0.8 g / m 2 ⁇ day.
  • the oxygen permeability is 0.5 cc / m 2 ⁇ day.
  • the warpage of the multilayer resin sheet was 13 mm.
  • the layer composition ratio of the resin layer was 17%, the total thickness was 900 ⁇ m, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
  • the water vapor transmission rate of the multilayer resin sheet obtained as described above As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.7 g / m 2 ⁇ day. As a result of measuring the oxygen permeability, as shown in Table 1, the oxygen permeability is 0.4 cc / m 2 ⁇ day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 15 mm.
  • Polyolefin-based resin layer (10) 80 ⁇ m / adhesive layer (11a) 15 ⁇ m / oxygen barrier resin layer (12) 40 ⁇ m / adhesive layer (11b) 15 ⁇ m / polystyrene-based resin layer (13) 950 ⁇ m
  • a multilayer resin sheet was obtained in the same manner as in Example 1 except that the resin layer had a layer composition ratio of 7% and a total thickness of 1100 ⁇ m.
  • the water vapor transmission rate of the multilayer resin sheet obtained as described above As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.7 g / m 2 ⁇ day. As a result of the oxygen permeability measurement, as shown in Table 1, the oxygen permeability is 0.6 cc / m 2 ⁇ day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank, and as a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 9 mm.
  • the layer composition ratio of the resin layer was 5%, the total thickness was 1000 ⁇ m, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
  • the water vapor transmission rate of the multilayer resin sheet obtained as described above As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.7 g / m 2 ⁇ day. As a result of measuring the oxygen transmission rate, as shown in Table 1, the oxygen transmission rate is 0.7 cc / m 2 ⁇ day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 7 mm.
  • the layer composition ratio of the resin layer was 3%, the total thickness was 1200 ⁇ m, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
  • the water vapor transmission rate is in the 0.7g / m 2 ⁇ day.
  • the oxygen permeability is 0.6 cc / m 2 ⁇ day.
  • the warpage of the multilayer resin sheet was 5 mm.
  • the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
  • PP resin was used as the polyolefin resin.
  • the polyolefin resin may be any one of, for example, a homopolymer of a polyolefin having about 2 to 8 carbon atoms such as ethylene, propylene, and butene-1.
  • a resin may be used. In this case, substantially the same effects as those of the first to fifth embodiments can be obtained.
  • Example 1 Compared with Example 1, the modification which makes the total thickness of a polyolefin-type resin layer, the thickness of the polystyrene-type resin layer used as a skin layer, etc. small, or forms a water vapor
  • each performance was evaluated as follows. ⁇ Comparative Example 1>
  • a single-layer sheet having a polystyrene resin layer of 450 ⁇ m was obtained with one 65 mm single-screw extruder.
  • the characteristic of this comparative example is that the resin sheet is composed of a single layer composed of only a polystyrene-based resin layer.
  • the water vapor transmission rate of the single layer resin sheet obtained from the comparative example is 7.0 g / m 2 ⁇ day.
  • the oxygen transmission rate is 350 cc / m 2 ⁇ day.
  • the oil resistance of the single layer resin sheet was evaluated, the oil resistance was evaluated as C rank, and as a result of evaluating the warp of the single layer resin sheet, the warp of the single layer resin sheet was 12 mm.
  • the moldability of a container molded using the single-layer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
  • a multilayer resin sheet was obtained in the same manner as in Example 1 except that the skin layer was made of polystyrene resin.
  • the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example is 4.2 g / m 2 ⁇ day.
  • the oxygen transmission rate is 1.2 cc / m 2 ⁇ day.
  • the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as C rank.
  • the warpage of the multilayer resin sheet was 15 mm.
  • the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
  • a multilayer resin sheet was obtained in the same manner as in Example 1 except that the layer composition ratio of the resin layer was 33% and the total thickness was 600 ⁇ m.
  • the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 0.7 g / m 2 ⁇ day. As a result of measuring the oxygen transmission rate, as shown in Table 2, the oxygen transmission rate is 0.8 cc / m 2 ⁇ day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 43 mm. Furthermore, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as C rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 12 mm. It has become.
  • the warp of the multilayer resin sheet is 43 mm, and the warpage of the container molded using the multilayer resin sheet is 12 mm.
  • the molded container is not acceptable because the moldability as in the mold is not obtained.
  • Polyolefin-based resin layer (10) 25 ⁇ m / adhesive layer (11a) 10 ⁇ m / oxygen barrier resin layer (12) 30 ⁇ m / adhesive layer (11b) 10 ⁇ m / polystyrene-based resin layer (13) 120 ⁇ m
  • the layer composition ratio of the resin layer was 13%, the total thickness was 195 ⁇ m, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
  • the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example is 0.9 g / m 2 ⁇ day.
  • the oxygen permeability is 1.0 cc / m 2 ⁇ day.
  • the moldability of a container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as B rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0 mm. It has become.
  • a multilayer resin sheet was obtained in the same manner as in Example 1 except that the polyolefin resin layer had a layer composition ratio of 84% and a total thickness of 450 ⁇ m.
  • the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 0.7 g / m 2 ⁇ day. As a result of measuring the oxygen transmission rate, as shown in Table 2, the oxygen transmission rate is 0.8 cc / m 2 ⁇ day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank, and as a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 9 mm.
  • the moldability of a container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as B rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0 mm. It has become.
  • the formability was evaluated as B rank, and during use, the thin part of the container after molding may be broken, and the barrier property may be reduced due to the intrusion of water vapor or oxygen There is.
  • a plurality of resin layers including a resin layer, the thickness of the entire sheet is 200 to 1300 ⁇ m, and the thickness of the polyolefin resin layer is 1% to 30% with respect to the thickness of the entire sheet.
  • a multilayer resin sheet formed by laminating resin layers has excellent thermoformability and oil resistance, and can suppress warpage of the sheet.
  • the oxygen barrier resin layer has a thickness of 10 to 50 ⁇ m and an oxygen permeability of 10 cc / m 2 ⁇ day or less.
  • the multilayer resin sheet having the above configuration has a water vapor transmission rate of 10 g / m 2 ⁇ day or less.
  • the multilayer resin sheet configured as described above, it has excellent thermoformability, oxygen barrier property, water vapor barrier property, and oil resistance, and can suppress warpage of the sheet.
  • the molded container formed by molding the multilayer resin sheet configured as described above has excellent thermoformability, oxygen barrier property, water vapor barrier property, oil resistance, and suppresses warping after thermoforming. Can do.

Abstract

A multilayer resin sheet which simultaneously has excellent thermal formability, oxygen barrier properties, vapor barrier properties and oil resistance, and which suppresses warping in the sheet and after thermal forming, and a shaped container obtained by forming said multilayer resin sheet are provided. This multilayer resin sheet, formed by laminating multiple resin layers, is characterized by being formed from a polyolefin resin layer that becomes the surface layer, an adhesive layer, an oxygen barrier resin layer and a resin layer which includes a polyethylene resin layer that becomes a bottom surface layer, wherein the thickness of the entire sheet is 200-1300 μm, the layer composition ratio of the thickness of the polyolefin resin layer to the thickness of the entire sheet is 1-30%, the polyolefin resin layer is preferably formed from a block polypropylene resin, the thickness of the oxygen barrier resin layer is preferably 10-50 μm, the oxygen permeability is preferably less than or equal to 10 cc/m2·day, and the water vapor permeability is preferably less than or equal to 10 g/m2·day.

Description

多層樹脂シート及び成形容器Multilayer resin sheet and molded container
　本発明は、ハイバリア性を有する多層樹脂シート、及びそれを熱成形してなる容器に関するものである。 The present invention relates to a multilayer resin sheet having high barrier properties and a container formed by thermoforming it.
　従来から、清涼飲料水や果汁飲料、嗜好飲食品等の容器としては、熱成形性、剛性に優れたポリスチレン系樹脂が用いられてきた。しかし、近年、ポリスチレン系樹脂層を最外層としてその中間に変性ポリオレフィン系樹脂等の接着層を介してエチレン－ビニルアルコール共重合体樹脂層を設けて酸素バリア性を付与し、内容物の酸化による品質低下を抑えた多層樹脂シート及びそれからなる多層容器が普及している（特許文献１参照）。 Conventionally, polystyrene resins having excellent thermoformability and rigidity have been used as containers for soft drinks, fruit juice drinks, and favorite foods and drinks. However, in recent years, a polystyrene resin layer is used as the outermost layer, and an ethylene-vinyl alcohol copolymer resin layer is provided in the middle through an adhesive layer such as a modified polyolefin resin to provide oxygen barrier properties. Multilayer resin sheets that suppress deterioration in quality and multilayer containers comprising the same have become widespread (see Patent Document 1).
　また、特許文献２には、ケイ素含有高分子と、熱可塑性樹脂と、を含むガスバリア材料を用い、熱可塑性樹脂のガラス転移温度を１００℃以上の値とするととともに、ガスバリア材料につき、プラズマイオン注入処理してあることを特徴とし、当該ケイ素含有高分子がポリシラザン化合物であり、熱可塑性樹脂が、ポリカーボネート樹脂、シクロポリオレフィン樹脂、およびポリサルフォン樹脂からなる群から選択される少なくとも一つであるにガスバリアシートが提案されている。 In Patent Document 2, a gas barrier material containing a silicon-containing polymer and a thermoplastic resin is used, the glass transition temperature of the thermoplastic resin is set to a value of 100 ° C. or higher, and plasma ion implantation is performed for the gas barrier material. The gas barrier sheet, wherein the silicon-containing polymer is a polysilazane compound, and the thermoplastic resin is at least one selected from the group consisting of a polycarbonate resin, a cyclopolyolefin resin, and a polysulfone resin. Has been proposed.
　更に、酸素及び水蒸気などのガスや湿気に対するバリア性及び耐溶剤性を有する光学樹脂シートが提案されている（特許文献３参照）。 Furthermore, an optical resin sheet having barrier properties and solvent resistance against gases such as oxygen and water vapor and moisture has been proposed (see Patent Document 3).
　より具体的には、光学的に透明な樹脂シートの少なくとも一方の表面に、ポリシラザン系無機重合体を主成分とする塗布膜を形成した後、それに対して加熱硬化処理を行うことによって、厚さ０．０２～５μｍのガスバリア層を備えることを特徴としている。 More specifically, after forming a coating film mainly composed of a polysilazane-based inorganic polymer on at least one surface of an optically transparent resin sheet, the thickness is determined by performing heat curing treatment on the coating film. A gas barrier layer having a thickness of 0.02 to 5 μm is provided.
　特許文献４には、テレフタル酸、エチレングリコール及び、１，４－シクロヘキサンジメタノールの３成分の共重合樹脂とポリブチレンテレフタレート樹脂との混合物からなる保香性樹脂層、ポリアミド樹脂からなる耐衝撃性付与層と、水蒸気バリア性樹脂層、ガスバリアー性樹脂層および熱可塑の支持体樹脂層とを順次積層してなる複合シートが提案されている。 Patent Document 4 discloses a fragrance-holding resin layer made of a mixture of a terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol terpolymer resin and a polybutylene terephthalate resin, and an impact resistance made of a polyamide resin. There has been proposed a composite sheet in which an application layer, a water vapor barrier resin layer, a gas barrier resin layer, and a thermoplastic support resin layer are sequentially laminated.
　特許文献５には、バリア性樹脂層の片面にポリプロピレン系樹脂を積層し、このポリプロピレン系樹脂層の合計厚みをシート全体の厚みに対して１０～４０％とすることで薄肉化しても、バリア性（特に酸素バリア性）、成形性、及び剛性や強度等の機械的特性に優れるシートが提案されている。 In Patent Document 5, a polypropylene resin is laminated on one side of a barrier resin layer, and the total thickness of the polypropylene resin layer is 10 to 40% of the total thickness of the sheet. Sheets having excellent properties (particularly oxygen barrier properties), moldability, and mechanical properties such as rigidity and strength have been proposed.
　一般に、食品等が収納された容器の内容物にポリフェノールやタンニン、カテキンといった成分が含まれる場合、溶存酸素または容器外から透過された酸素との強力な酸化作用により変色や変質、品質劣化が起こることが知られている。また上記以外にも、例えば、ヨーグルト成分に含まれるビフィズス菌等の嫌気性成分についても溶存酸素または容器外から透過された酸素により菌数が死滅して減少するといった現象が起こることが知られている。 In general, when the contents of containers containing foods contain components such as polyphenols, tannins, and catechins, discoloration, alteration, and quality degradation occur due to strong oxidizing action with dissolved oxygen or oxygen that has permeated from outside the container. It is known. In addition to the above, for example, anaerobic components such as bifidobacteria contained in the yogurt component are also known to cause a phenomenon that the number of bacteria is killed and reduced by dissolved oxygen or oxygen permeated from outside the container. Yes.
　一方で、ミルクポーション等の成分中に水分を多分に含む液状物が収納されている容器では、容器構成に水蒸気バリア性を有する層がない場合、成分中の水分が水蒸気として容器外に散逸することで液状物の粘度が上昇して出にくくなる、または、変色するといった現象が起きる。 On the other hand, in a container in which a liquid material containing a large amount of water in components such as milk potion is stored, if there is no layer having a water vapor barrier property in the container structure, water in the component is dissipated out of the container as water vapor As a result, a phenomenon occurs in which the viscosity of the liquid material is increased and the liquid material becomes difficult to be emitted or discolored.
　また、食品等が収納された容器を運搬する場合、運搬中の振動や外部の温度環境から容器そのものの破損を防ぐためや容器の内容物の品質低下を抑制する目的として、梱包材の中に多数の容器を積層して保護する、もしくは温度管理された運搬方式が適用される。しかしながら、容器に収納される食品類には油脂成分を含むものも多く、油脂成分がその分子骨格中に極性基を有する場合、容器を構成する樹脂の極性基と反応することで容器の強度が低下し、運搬や保管の際の取り扱いにより容器が破損して内容物が流出してしまう可能性がある。 Also, when transporting containers that contain food, etc., in order to prevent damage to the containers themselves from vibrations during transportation and external temperature environments, and to prevent deterioration of the contents of the containers, A transport system in which a large number of containers are stacked and protected or temperature controlled is applied. However, many foods contained in containers contain fat and oil components, and when the fat and oil components have polar groups in their molecular skeleton, the strength of the container is reduced by reacting with the polar groups of the resin constituting the container. There is a possibility that the container will be damaged due to handling during transportation and storage, and the contents may flow out.
　特許文献５では、耐油性を持つポリプロピレン系樹脂をシートの最表面に形成させ、更にスチレン系樹脂、スチレン－ジエン系共重合体及びオレフィン系樹脂で構成された樹脂組成物層を支持層として形成させるシート構成が提案されている。しかしながら、結晶性のポリプロピレン系樹脂と非結晶性のスチレン系樹脂を積層することで容器成形後に反りが発生し易くなり、蓋材とのシール性不良や容器としての外観が悪くなるといった課題が起きる可能性が考えられる。 In Patent Document 5, an oil-resistant polypropylene resin is formed on the outermost surface of a sheet, and a resin composition layer composed of a styrene resin, a styrene-diene copolymer and an olefin resin is formed as a support layer. A sheet configuration has been proposed. However, by laminating a crystalline polypropylene resin and an amorphous styrene resin, warping is likely to occur after container molding, resulting in problems such as poor sealing with the lid material and poor appearance as a container. There is a possibility.
　特許文献１～５には、上記の酸素や水蒸気といった容器の内容物に影響を与える成分を遮断する特性を主眼とした記載がされている。しかしながら、上記のような耐油性や容器の外観や機能性に影響を及ぼす反りといった付加性能について網羅することが考慮された構成とはされていない。 Patent Documents 1 to 5 mainly describe the characteristics of blocking components that affect the contents of the container such as oxygen and water vapor. However, it is not configured to cover additional performance such as the above-described oil resistance and warpage affecting the appearance and functionality of the container.
特開平１１－５８６１９号公報Japanese Patent Laid-Open No. 11-58619 ＷＯ２０１３１７５９１１Ａ１公報WO2013175911A1 特開平８－１６９０７８号公報Japanese Patent Laid-Open No. 8-169078 特開２０００－１０８２８８号公報JP 2000-108288 A 特許第３９６７８９９号Japanese Patent No. 3967899
　本発明は上記事情に鑑みてなされたもので、優れた熱成形性、酸素バリア性、水蒸気バリア性、耐油性をあわせ持ち、且つ、シートおよび熱成形後の反りを抑制するハイバリア性の多層樹脂シート、及びそれを成形してなる成形容器を提供することを目的とする。 The present invention has been made in view of the above circumstances, and has a high barrier property multilayer resin that has excellent thermoformability, oxygen barrier property, water vapor barrier property, and oil resistance, and suppresses warpage after the sheet and thermoforming. An object is to provide a sheet and a molded container formed by molding the sheet.
　すなわち、本発明者は、前記特性を具備することを目的として鋭意検討した結果、複数の樹脂層を積層して形成される多層樹脂シートであって、表皮層となるポリオレフィン系樹脂層と、接着層と、酸素バリア性樹脂層と、下皮層となるポリスチレン系樹脂層を含む樹脂層とから形成されてなり、シート全体の厚みを２００～１３００μｍとし、ポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を１％～30％とすることで前記課題を解決できることを見出し、本発明を完成するに至ったものである。 That is, the present inventor has intensively studied for the purpose of having the above characteristics, and as a result, is a multilayer resin sheet formed by laminating a plurality of resin layers, and a polyolefin-based resin layer serving as a skin layer and an adhesive Layer, an oxygen-barrier resin layer, and a resin layer including a polystyrene-based resin layer serving as an undercoat layer. The thickness of the entire sheet is 200 to 1300 μm, and the thickness of the polyolefin-based resin layer is the thickness of the entire sheet. The present inventors have found that the above problems can be solved by setting the layer composition ratio to 1% to 30%, and have completed the present invention.
　また、前記ポリオレフィン系樹脂層がブロックポリプロピレン樹脂から形成されていることが好ましい。ここでブロックポリプロピレン樹脂とは、ホモプロピレンブロックを連続相としてエチレンプロピレンゴム（ＥＰＲ）が分散層を形成しているものをさす。 Further, it is preferable that the polyolefin resin layer is formed of a block polypropylene resin. Here, the block polypropylene resin refers to one in which a homopropylene block is a continuous phase and ethylene propylene rubber (EPR) forms a dispersion layer.
　また、前記ポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を５％以上且つ１０％未満とすることがより好ましい。 Further, it is more preferable that the thickness of the polyolefin-based resin layer is 5% or more and less than 10% with respect to the thickness of the entire sheet.
　また、前記酸素バリア性樹脂層の厚みが１０～５０μｍであり、酸素透過率が１０ｃｃ／ｍ２・ｄａｙ以下であることが好ましい。 The thickness of the oxygen barrier resin layer is preferably 10 to 50 μm, and the oxygen permeability is preferably 10 cc / m 2 · day or less.
　また、上記のように構成した多層樹脂シートの水蒸気透過率が１０ｇ／ｍ２・ｄａｙ以下であることが好ましい。 Moreover, it is preferable that the water vapor permeability | transmittance of the multilayer resin sheet comprised as mentioned above is 10 g / m < 2 > * day or less.
　さらに、本発明は、上記で構成された多層樹脂シートをポリオレフィン系樹脂層が容器の内面に位置するよう熱成形してなる成形容器を提供する。 Furthermore, the present invention provides a molded container obtained by thermoforming the multilayer resin sheet configured as described above so that the polyolefin resin layer is positioned on the inner surface of the container.
　上記のように構成した多層樹脂シート、及びそれを成形してなる成形容器は優れた熱成形性、酸素バリア性、水蒸気バリア性、耐油性をあわせ持ち、且つ、シートおよび熱成形後の反りを抑制することができる。 The multilayer resin sheet configured as described above and a molded container formed by molding the same have excellent thermoformability, oxygen barrier property, water vapor barrier property, oil resistance, and warp after the sheet and thermoforming. Can be suppressed.
本発明の実施形態に係る多層樹脂シートの積層構造の一例を示す概略縦側断面図である。It is a schematic longitudinal cross-sectional view which shows an example of the laminated structure of the multilayer resin sheet which concerns on embodiment of this invention. 本発明の多層樹脂シートの反り評価の方法を示す概略図である。It is the schematic which shows the method of curvature evaluation of the multilayer resin sheet of this invention. 本発明の成形容器の一例とその反り評価の方法を示す概略図である。It is the schematic which shows an example of the shaping | molding container of this invention, and the method of the curvature evaluation. 本発明における耐油性評価の方法を示す概略図である。It is the schematic which shows the method of oil resistance evaluation in this invention.
　図１に示すように、本発明の一実施形態としての多層樹脂シートは、酸素バリア性樹脂層１２に接着層１１ａを介して最表面に表皮層となるポリオレフィン系樹脂層１０が積層され、また、その反対側に同じく接着層１１ｂを介してポリスチレン系樹脂層が積層されてなる。シート全体の厚みは２００～１３００μｍであり、ポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を１～３０％としている。より好ましくはポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を２％以上且つ１０％未満とする。更に好ましくはポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を５％以上且つ１０％未満とする。 As shown in FIG. 1, in the multilayer resin sheet as one embodiment of the present invention, an oxygen barrier resin layer 12 is laminated with a polyolefin-based resin layer 10 serving as a skin layer on the outermost surface through an adhesive layer 11a. A polystyrene resin layer is laminated on the opposite side through the adhesive layer 11b. The thickness of the entire sheet is 200 to 1300 μm, and the thickness of the polyolefin resin layer is set to 1 to 30% of the layer composition ratio with respect to the thickness of the entire sheet. More preferably, the thickness of the polyolefin resin layer is 2% or more and less than 10% with respect to the thickness of the entire sheet. More preferably, the thickness of the polyolefin resin layer is 5% or more and less than 10% with respect to the thickness of the entire sheet.
　以下、上記多層樹脂シート及びそれを熱成形してなる成形容器について詳細に説明する。
　本発明の一実施形態に係る多層樹脂シートの層構成は、ポリオレフィン系樹脂層／接着層／酸素バリア性樹脂層／接着層／ポリスチレン系樹脂層であり、簡素的には表皮層／接着層／酸素バリア層／接着層／下皮層との表記とする。下皮層には、本発明の多層樹脂シートや成形容器を製造する工程で発生するスクラップと称される部位を廃棄することなく、細かく粉砕して戻す若しくは熱溶融後にリペレット化して再生品として戻す層を新たに設けた構成としてもよい。 Hereinafter, the multilayer resin sheet and a molded container formed by thermoforming the multilayer resin sheet will be described in detail.
The multilayer resin sheet according to an embodiment of the present invention has a layer structure of polyolefin resin layer / adhesive layer / oxygen barrier resin layer / adhesive layer / polystyrene resin layer, and is simply a skin layer / adhesive layer / The notation is oxygen barrier layer / adhesive layer / undercoat layer. The lower skin layer is a layer that is finely pulverized or re-pelletized after heat melting and returned as a recycled product without discarding the part called scrap generated in the process of producing the multilayer resin sheet or molded container of the present invention. It is good also as a structure which provided newly.
　また、下皮層側には、特に限定されないが、例えばダイレクト印刷や印刷されたフィルムを積層するといった方法により印刷面を設けた構成としてもよい。 Further, although it is not particularly limited on the lower skin layer side, for example, a configuration may be adopted in which a printing surface is provided by a method such as direct printing or laminating printed films.
　本発明におけるシート全体の厚みは２００～１３００μｍが好ましい。２００μｍ未満であると熱成形後の容器の厚みが薄い箇所が形成されてしまうことで、座屈強度と称される圧縮や圧力に対する耐性を表す容器強度の低下により、例えば、容器の内面に内容物が収納された状態で運搬、保管される際の振動や圧縮により容器の変形や破損が発生する可能性がある。１３００μｍを超えると、熱成形の際にシートの厚み方向に十分に熱が伝わりにくくなり、成形不良が発生する可能性がある。 The thickness of the entire sheet in the present invention is preferably 200 to 1300 μm. If the thickness of the container after thermoforming is less than 200 μm, a thin portion of the container is formed, and the content of the container on the inner surface of the container is reduced due to a decrease in container strength representing resistance to compression and pressure called buckling strength. There is a possibility that deformation or breakage of the container may occur due to vibration or compression when the object is stored and transported. When it exceeds 1300 μm, heat is not sufficiently transmitted in the thickness direction of the sheet during thermoforming, and molding defects may occur.
　上記の座屈強度の評価方法としては例えば、成形容器のフランジ部を下方として平滑な面の上に容器を静置し、上部となる容器底面の上に一定荷重の錘をのせて変形を確認する方法、もしくは、プッシュプルゲージと呼ばれる引張や圧縮にかかる荷重を測定する装置を用いて容器が変形する荷重を測定する方法などが挙げられるが、これに限定されず好適な方法により評価することができる。 As a method for evaluating the buckling strength, for example, the container is allowed to stand on a smooth surface with the flange portion of the molded container at the bottom, and deformation is confirmed by placing a weight with a constant load on the bottom surface of the container. Or a method of measuring a load that deforms a container using a device called a push-pull gauge that measures a load applied to tension or compression, but is not limited to this, and is evaluated by a suitable method. Can do.
　本実施形態の多層樹脂シートの製膜方法としては、特に限定されず、一般的な製膜方法を用いることができる。例えば、４台もしくはそれ以上の単軸または二軸押出機を用いて各々の原料樹脂を溶融押出し、セレクタープラグを内蔵したフィードブロックとＴダイによって多層樹脂シートを得る共押出の方法や、マルチマニホールドダイを使用して多層樹脂シートを得る方法が挙げられる。 The film forming method of the multilayer resin sheet of the present embodiment is not particularly limited, and a general film forming method can be used. For example, a coextrusion method in which each raw resin is melt-extruded using four or more single-screw or twin-screw extruders, and a multilayer resin sheet is obtained by a feed block and a T-die incorporating a selector plug, or a multi-manifold The method of obtaining a multilayer resin sheet using die | dye is mentioned.
　ポリオレフィン系樹脂層１０は、その厚みがシート全体の厚みに対する層構成比率を１～３０％とすることが好ましい。より好ましくはその層構成比率が２％以上且つ１０％未満である。更に好ましくはその層構成比率が５％以上且つ１０％未満である。ここで表記されている層構成比率とは、ポリオレフィン系樹脂層の厚みをシート全体の厚みで除した値から百分率で算出したものとする。シート全体に対する層構成比率が１％未満では、特にシート全体厚みが薄い場合にポリオレフィン系樹脂層として十分な厚みが確保できず、水蒸気バリア性等の機能性が発現されない可能性がある。また、３０％を超えると表皮層を形成する結晶性のポリオレフィン系樹脂層が熱成形の際に加熱収縮が大きくなる傾向にあるのに対して、下皮層を形成する非結晶性のポリスチレン系樹脂層では加熱収縮が小さくなるために、表皮層と下皮層での加熱収縮率に差異が生じることで、シートもしくは熱成形後の容器に反りが発生する可能性がある。 The polyolefin-based resin layer 10 preferably has a layer composition ratio of 1 to 30% with respect to the thickness of the entire sheet. More preferably, the layer composition ratio is 2% or more and less than 10%. More preferably, the layer composition ratio is 5% or more and less than 10%. The layer composition ratio described here is calculated as a percentage from a value obtained by dividing the thickness of the polyolefin resin layer by the thickness of the entire sheet. When the layer composition ratio with respect to the entire sheet is less than 1%, particularly when the entire sheet thickness is thin, a sufficient thickness as a polyolefin-based resin layer cannot be secured, and functions such as water vapor barrier properties may not be exhibited. Further, when the content exceeds 30%, the crystalline polyolefin resin layer that forms the skin layer tends to increase in heat shrinkage during thermoforming, whereas the non-crystalline polystyrene resin that forms the lower skin layer. Since the heat shrinkage of the layer is small, a difference in the heat shrinkage rate between the skin layer and the lower skin layer may cause warpage of the sheet or the container after thermoforming.
　本発明に記載のポリオレフィン系樹脂から構成される表皮層１０は、基本的にシートを熱成形した容器の内面（内容物と接触する面）に位置するものであり、主に、水蒸気バリア性や耐油性を持たせる目的で形成されるものである。また、熱湯が注がれるような容器に対しては９０℃以上の熱湯温度に耐えうる樹脂を選定し、耐熱性を付与することが好ましい。 The skin layer 10 composed of the polyolefin-based resin described in the present invention is basically located on the inner surface (the surface in contact with the contents) of a container formed by thermoforming a sheet. It is formed for the purpose of imparting oil resistance. Moreover, it is preferable to provide a heat resistance by selecting a resin that can withstand a hot water temperature of 90 ° C. or higher for a container into which hot water is poured.
　上記のように構成された多層樹脂シートは、その水蒸気透過率が好ましくは１０ｇ／ｍ２・ｄａｙ以下であり、更に好ましくは５ｇ／ｍ２・ｄａｙ以下である。１０ｇ／ｍ２・ｄａｙを超えると、熱成形容器の内容部が水分の透過により変質や変色が生じるものである場合に十分な抑制機能が発現しない可能性がある。 The multilayer resin sheet configured as described above preferably has a water vapor transmission rate of 10 g / m 2 · day or less, and more preferably 5 g / m 2 · day or less. If it exceeds 10 g / m 2 · day, there is a possibility that a sufficient suppression function will not be exhibited when the contents of the thermoformed container are altered or discolored due to the permeation of moisture.
　本発明の構成におけるポリオレフィン系樹脂としては、エチレン、プロピレン、ブテン－１等の炭素数２～８程度のポリオレフィンの単独重合体が挙げられるがこれに限定されるものではない。 Examples of the polyolefin resin in the constitution of the present invention include, but are not limited to, a homopolymer of a polyolefin having about 2 to 8 carbon atoms such as ethylene, propylene and butene-1.
　ポリエチレン樹脂としては一般的なものとして挙げられる高密度ポリエチレン（ＨＤＰＥ）、直鎖低密度　ポリエチレン（ＬＬＤＰＥ）、低密度ポリエチレン（ＬＤＰＥ）等を適用することができる。また、ポリプロピレン樹脂としてはホモポリマー、ランダムコポリマーとブロックコポリマーの何れも適用することができるが、本発明においては特にブロックコポリマーが好適に用いられる。ブロックコポリマーとしては、測定温度＝１９０℃、剪断速度１００～３００（１／ｓｅｃ）における粘度（Ｐａ・ｓ）が５００００～１００００００であり、１９０℃～２３０℃における粘度変化が０．５～１５Ｐａ・ｓ／℃の範囲の樹脂を使用することが更に好ましい。用いられるポリオレフィン系樹脂はシートや熱成形後の容器の外観が損なわれない程度に適宜ブレンドして用いることも可能である。 As the polyethylene resin, high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and the like that are commonly used can be applied. Also, as the polypropylene resin, any of homopolymer, random copolymer and block copolymer can be applied. In the present invention, block copolymer is particularly preferably used. The block copolymer has a viscosity (Pa · s) at a measurement temperature of 190 ° C., a shear rate of 100 to 300 (1 / sec) of 50,000 to 1,000,000, and a viscosity change at 190 to 230 ° C. of 0.5 to 15 Pa ·. More preferably, a resin having a range of s / ° C. is used. The polyolefin resin to be used can be appropriately blended to such an extent that the appearance of the sheet and the container after thermoforming is not impaired.
　本実施形態の酸素バリア性樹脂層１２を構成する酸素バリア性樹脂としては、例えば、エチレン－ビニルアルコール共重合体樹脂、ポリアミド樹脂、ポリビニルアルコール、ポリ塩化ビニリデン等が代表的なものとして挙げられるがこれらに限定されるものではない。その中でも、押出成形性の面でエチレン－ビニルアルコール共重合体樹脂が好ましい。 Typical examples of the oxygen barrier resin constituting the oxygen barrier resin layer 12 of the present embodiment include ethylene-vinyl alcohol copolymer resin, polyamide resin, polyvinyl alcohol, and polyvinylidene chloride. It is not limited to these. Among these, ethylene-vinyl alcohol copolymer resin is preferable in terms of extrusion moldability.
　エチレン－ビニルアルコール共重合体樹脂は、通常、エチレン－酢酸ビニル共重合体を鹸化して得られるものであり、酸素バリア性、押出成形性を具備させる為に、エチレン含有量が１０～６５モル％、好ましくは２０～５０モル％で、鹸化度が９０％以上、好ましくは９５％以上のものが好ましい。 The ethylene-vinyl alcohol copolymer resin is usually obtained by saponifying an ethylene-vinyl acetate copolymer, and has an ethylene content of 10 to 65 mol in order to provide oxygen barrier properties and extrusion moldability. %, Preferably 20 to 50 mol%, and a saponification degree of 90% or more, preferably 95% or more.
　また、ポリアミド樹脂としては、カプロラクタム、ラウロラクタム等のラクタム重合体、６－アミノカプロン酸、１１－アミノウンデカン酸、１２－アミノドデカン酸等のアミノカルボン酸の重合体、ヘキサメチレンジアミン、デカメチレンジアミン、ドデカメチレンジアミン、２，２，４－または２，４，４－トリメチルヘキサメチレンジアミン等の脂肪族ジアミン、１，３－または１，４－ビス（アミノメチル）シクロヘキサン、ビス（ｐ－アミノシクロヘキシルメタン）等の脂環式ジアミン、ｍ－またはｐ－キシリレンジアミン等の芳香族ジアミン等のジアミン単位と、アジピン酸、スベリン酸、セバシン酸等の脂肪族ジカルボン酸、シクロヘキサンジカルボン酸等の脂環式ジカルボン酸、テレフタル酸、イソフタル酸等の芳香族ジカルボン酸等のジカルボン酸単位との重縮合体、並びにこれらの共重合体等が挙げられる。 Examples of the polyamide resin include lactam polymers such as caprolactam and laurolactam, polymers of aminocarboxylic acids such as 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid, hexamethylenediamine, decamethylenediamine, Aliphatic diamines such as dodecamethylenediamine, 2,2,4- or 2,4,4-trimethylhexamethylenediamine, 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane) ), Alicyclic diamines such as m- or p-xylylenediamine, diamine units such as aromatic diamines, aliphatic dicarboxylic acids such as adipic acid, suberic acid and sebacic acid, and alicyclics such as cyclohexanedicarboxylic acid Aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, etc. Polycondensates of a dicarboxylic acid units, such as carboxylic acid, and copolymers thereof.
　ポリアミド樹脂として、具体的には、ナイロン６、ナイロン９、ナイロン１１、ナイロン１２、ナイロン６６、ナイロン６１０、ナイロン６１１、ナイロン６１２、ナイロン６Ｔ、ナイロン６Ｉ、ナイロンＭＸＤ６、ナイロン６／６６、ナイロン６／６１０、ナイロン６／６Ｔ、ナイロン６Ｉ／６Ｔ等があり、中でもナイロン６、ナイロンＭＸＤ６が好適である。 Specific examples of the polyamide resin include nylon 6, nylon 9, nylon 11, nylon 12, nylon 66, nylon 610, nylon 611, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6/66, nylon 6 / 610, nylon 6 / 6T, nylon 6I / 6T, etc., among which nylon 6 and nylon MXD6 are preferred.
　また、前記酸素バリア性樹脂層１２の厚みは、好ましくは１０～５０μｍ、より好ましくは２０～４０μｍである。１０μｍ未満であると、シートを熱成形した後の容器において酸素バリア性樹脂層の厚みが極端に薄肉化することで、容器内に収納された内容物の酸化劣化による品質低下を抑える程の酸素バリア性能が得られない可能性があり、また、５０μｍを超えると、熱成形の後に施される容器の打ち抜き加工時に所謂ヒゲバリと呼ばれる外観不良が発生する可能性がある。 The thickness of the oxygen barrier resin layer 12 is preferably 10 to 50 μm, more preferably 20 to 40 μm. If the thickness is less than 10 μm, the thickness of the oxygen barrier resin layer in the container after thermoforming the sheet becomes extremely thin, so that the oxygen contained in the container can be prevented from deterioration due to oxidative degradation. There is a possibility that the barrier performance cannot be obtained, and when it exceeds 50 μm, there is a possibility that a so-called appearance defect called “hibari burr” occurs at the time of punching of the container applied after thermoforming.
　前記酸素バリア性樹脂層１２の酸素透過率は好ましくは１０ｃｃ／ｍ２・ｄａｙ以下であり、更に好ましくは５ｃｃ／ｍ２・ｄａｙ以下である。１０ｃｃ／ｍ２・ｄａｙを超えると、熱成形容器の内容部が酸化劣化するものである場合に十分な抑制機能が発現しない可能性がある。 The oxygen permeability of the oxygen barrier resin layer 12 is preferably 10 cc / m 2 · day or less, and more preferably 5 cc / m 2 · day or less. When it exceeds 10 cc / m 2 · day, there is a possibility that a sufficient suppression function is not exhibited when the contents of the thermoformed container are subject to oxidative degradation.
　本実施形態の接着層１１ａ，１１ｂを構成する樹脂としては、変性ポリオレフィン系重合体が好ましい。接着層を構成する変性ポリオレフィン系重合体としては、エチレン、プロピレン、ブテン－１等の炭素数２～８程度のポリオレフィンの単独重合体、それらのポリオレフィンとエチレン、プロピレン、ブテン－１、３－メチルブテン－１、ペンテン－１、４－メチルペンテン－１、ヘキセン－１、オクテン－１、デセン－１等の炭素数２～２０程度の他のポリオレフィンや酢酸ビニル、塩化ビニル、アクリル酸、メタクリル酸、アクリル酸エステル、メタクリル酸エステル、ポリスチレン等のビニル化合物との共重合体等のポリオレフィン系樹脂や、エチレン－プロピレン共重合体、エチレン－プロピレン－ジエン共重合体、エチレン－ブテン－１共重合体、プロピレン－ブテン－１共重合体等のポリオレフィン系ゴムを、アクリル酸、メタクリル酸、クロトン酸、イソクロトン酸、マレイン酸、フマル酸、イタコン酸、シトラコン酸、テトラヒドロフタル酸等の不飽和カルボン酸、または、その酸ハライド、アミド、イミド、無水物、エステル等の誘導体、具体的には、塩化マレニル、マレイミド、無水マレイン酸、無水シトラコン酸、マレイン酸モノメチル、マレイン酸ジメチル、マレイン酸グリシジル等でグラフト反応条件下に変性したものが代表的なものとして挙げられる。 As the resin constituting the adhesive layers 11a and 11b of this embodiment, a modified polyolefin polymer is preferable. Examples of the modified polyolefin polymer constituting the adhesive layer include homopolymers of polyolefins having about 2 to 8 carbon atoms such as ethylene, propylene and butene-1, and these polyolefins and ethylene, propylene, butene-1, 3-methylbutene. -1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, decene-1, and other polyolefins having about 2 to 20 carbon atoms, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, Polyolefin resins such as copolymers with vinyl compounds such as acrylic acid esters, methacrylic acid esters, polystyrene, ethylene-propylene copolymers, ethylene-propylene-diene copolymers, ethylene-butene-1 copolymers, Polyolefin rubber such as propylene-butene-1 copolymer is used for acrylic acid, Unsaturated carboxylic acids such as rillic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, or derivatives thereof such as acid halides, amides, imides, anhydrides, esters, etc. Specifically, those modified under the graft reaction conditions with maleyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, glycidyl maleate and the like can be cited as representative examples.
　変性ポリオレフィン系重合体として、中でも、不飽和ジカルボン酸またはその無水物、特にマレイン酸またはその無水物で変性したエチレン系樹脂、プロピレン系樹脂、またはエチレン－プロピレンまたはブテン－１共重合体ゴムが好適である。 As the modified polyolefin polymer, among them, an ethylene resin, a propylene resin, or an ethylene-propylene or butene-1 copolymer rubber modified with an unsaturated dicarboxylic acid or an anhydride thereof, particularly maleic acid or an anhydride thereof is preferable. It is.
　接着層の厚みは、いずれの層も、好ましくは５～５０μｍ、より好ましくは１０～３０μｍである。５μｍ未満であると、十分な層間の接着強度が得られなくなる可能性があり、また、５０μｍを超えると、熱成形の後に施される容器の打ち抜き加工時に所謂ヒゲバリと呼ばれる外観不良が発生する可能性がある。 The thickness of the adhesive layer is preferably 5 to 50 μm, more preferably 10 to 30 μm in any layer. If the thickness is less than 5 μm, sufficient adhesion strength between layers may not be obtained. If the thickness exceeds 50 μm, an appearance defect called so-called whirling may occur at the time of punching a container applied after thermoforming. There is sex.
　また、本実施形態のポリスチレン系樹脂層１３を構成するポリスチレン系樹脂としては、ポリスチレン、α－メチルポリスチレン、ｐ－メチルポリスチレン、ジメチルポリスチレン、ｐ－ｔ－ブチルポリスチレン、クロロポリスチレン等のポリスチレン系モノマーの単独または共重合体、それらポリスチレン系モノマーと他のモノマーとの共重合体、例えばポリスチレン－アクリルニトリル共重合体（ＡＳ樹脂）、または、前記ポリスチレン系モノマーとさらに他のポリマー、例えば、ポリブタジエン、ポリスチレン－ブタジエン共重合体、ポリイソプレン、ポリクロロプレン等のジエン系ゴム質重合体の存在下にグラフト重合したグラフト重合体、例えばハイインパクトポリポリスチレン（ＨＩＰＳ樹脂）、ポリスチレンーアクリルニトリルグラフト重合体（ＡＢＳ樹脂）等が挙げられる。 The polystyrene resin constituting the polystyrene resin layer 13 of the present embodiment includes polystyrene monomers such as polystyrene, α-methyl polystyrene, p-methyl polystyrene, dimethyl polystyrene, pt-butyl polystyrene, chloropolystyrene. Homopolymer or copolymer, copolymer of polystyrene monomer and other monomer, such as polystyrene-acrylonitrile copolymer (AS resin), or other polymer such as polystyrene monomer and further polymer, such as polybutadiene, polystyrene -Graft polymers grafted in the presence of diene rubber polymers such as butadiene copolymer, polyisoprene, polychloroprene, such as high impact polypolystyrene (HIPS resin), polystyrene-acrylonitrile Rugurafuto polymer (ABS resin).
　ポリスチレン系樹脂として、中でもポリポリスチレン（ＧＰＰＳ樹脂）、ハイインパクトポリポリスチレン（ＨＩＰＳ樹脂）が成形容器の剛性、成形性の観点から好ましく、単体で使用することはもちろんのこと、適宜、ブレンド比率を調整することで配合して使用しても差し支えない。 Polystyrene (GPPS resin) and high-impact polypolystyrene (HIPS resin) are preferable from the viewpoint of the rigidity and moldability of the molded container, and the blend ratio can be adjusted as appropriate. It can be used by blending.
　ポリスチレン系樹脂は、ブタジエンゴム成分を４～８質量％含有することが好ましい。ブタジエンゴム成分含有量は、ＧＰＰＳとＨＩＰＳのブレンドにより調整するのが簡便な方法であるが、ＨＩＰＳの製造段階で調整しても構わない。４質量％未満であると実用上十分な容器強度が得られなくなる可能性があり、８質量％を超えると、特に熱盤を用いた熱成形時に熱盤付着等の不具合を引き起こす可能性がある。 The polystyrene resin preferably contains 4 to 8% by mass of a butadiene rubber component. The butadiene rubber component content is a simple method of adjusting by blending GPPS and HIPS, but it may be adjusted at the manufacturing stage of HIPS. If it is less than 4% by mass, there is a possibility that practically sufficient container strength may not be obtained, and if it exceeds 8% by mass, there is a possibility of causing problems such as adhesion of a hot plate, particularly during thermoforming using a hot platen. .
　前記ポリスチレン系樹脂層１３には、必要に応じて、本発明の効果を阻害しない範囲で、顔料、染料などの着色剤、シリコンオイルやアルキルエステル系等の離型剤、ガラス繊維等の繊維状強化剤、タルク、クレー、シリカなどの粒状滑剤、スルホン酸とアルカリ金属などとの塩化合物やポリアルキレングリコール等の帯電防止剤及び紫外線吸収剤、抗菌剤のような添加剤を添加することができる。 If necessary, the polystyrene resin layer 13 may have a colorant such as a pigment or a dye, a release agent such as silicon oil or an alkyl ester, or a fiber such as glass fiber as long as the effect of the present invention is not impaired. Additives such as reinforcing agents, granular lubricants such as talc, clay, silica, salt compounds of sulfonic acid and alkali metals, antistatic agents such as polyalkylene glycol, UV absorbers, and antibacterial agents can be added .
　本実施形態のポリスチレン系樹脂層１３の厚みは、好ましくは２００～９００μｍ、より好ましくは３００～７００μｍである。２００μｍ未満であると、成形後の容器各部の厚みがより均等にならない等、優れた熱成形性が発現されない可能性があり、また、９００μｍを超えると、熱成形の際にシートの厚み方向に十分に熱が伝わりにくくなり、成形不良が発生する可能性がある。 The thickness of the polystyrene resin layer 13 of this embodiment is preferably 200 to 900 μm, more preferably 300 to 700 μm. If it is less than 200 μm, the thickness of each part of the container after molding may not be more uniform, and there is a possibility that excellent thermoformability may not be expressed. If it exceeds 900 μm, in the thickness direction of the sheet during thermoforming Heat may not be sufficiently transmitted, and molding defects may occur.
　図３に、本発明の成形容器の一例を示す。本発明の成形容器は、本発明の多層樹脂シートを熱成形してなる。熱成形方法としては、一般的な真空成形、圧空成形や、これらの応用として、シートの片面にプラグを接触させて成形を行うプラグアシスト法、また、シートの両面に一対をなす雄雌型を接触させて成形を行う、いわゆるマッチモールド成形と称される方法等が挙げられるが、これらに限定されるものではない。また、成形前にシートを加熱軟化させる方法として非接触加熱である赤外線ヒーター等による輻射加熱やシートを加熱された熱盤に直接触れさせて軟化させる熱盤加熱等、公知のシート加熱方法を適用することができる。 FIG. 3 shows an example of the molded container of the present invention. The molded container of the present invention is obtained by thermoforming the multilayer resin sheet of the present invention. Thermoforming methods include general vacuum forming, pressure forming, and plug assist method in which plugs are formed by contacting a plug on one side of the sheet, and male and female molds that form a pair on both sides of the sheet. Examples of the method include so-called match mold molding, which is performed by bringing them into contact with each other, but is not limited thereto. In addition, as a method of heating and softening the sheet before forming, a known sheet heating method such as radiant heating by an infrared heater or the like which is non-contact heating, or hot plate heating to soften the sheet by directly touching the heated hot plate is applied. can do.
　熱成形の際の成形温度は、樹脂の融点等を考慮して適切に設定されるが、シート加熱温度が低すぎると加熱成形後の容器の賦型状態が不十分であり、逆にシート加熱温度が高すぎると熱盤への融着等の不具合を起こす等の不良が発生する恐れがあるため、適宜の温度に設定することが好ましい。 The molding temperature at the time of thermoforming is appropriately set in consideration of the melting point of the resin, etc., but if the sheet heating temperature is too low, the molded state of the container after thermoforming is insufficient, and conversely the sheet heating If the temperature is too high, there is a risk that a defect such as a fusing to the hot platen may occur, so it is preferable to set the temperature appropriately.
　以下、実施例及び比較例を挙げて本発明をより具体的に説明するが、本発明は実施例等の内容に何ら限定されるものではない。 Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the contents of Examples and the like.
　実施例で用いた樹脂原料は以下の通りである。
（１）ポリオレフィン系樹脂層
　ＰＰ樹脂：「３０８０」
（Ｆｏｒｍｏｓａ　Ｐｏｌｙｐｒｏｐｙｌｅｎｅ　Ｃｏ．,Ｌｔｄ．製、ＭＩ：８．５ｇ／１０ｍｉｎ．（１９０℃、２．１６ｋｇｆ）、Ｂｌｏｃｋ－ＰＰ）
（２）酸素バリア性樹脂層
　エチレン－ビニルアルコール共重合体（ＥＶＯＨ）　「エバールＪ１７１Ｂ」
（クラレ社製、ＭＩ：１．７ｇ／１０ｍｉｎ．（１９０℃、２．１６ｋｇｆ）、エチレン含量３２ｍｏｌ％）
（３）接着層
　変性ポリオレフィン系重合体（変性ＰＯ）　「モディックＦ５０２Ｃ」
（三菱化学社製、ＭＩ：１．３ｇ／１０ｍｉｎ．（１９０℃、２．１６ｋｇｆ））
（４）ポリスチレン系樹脂層
　ＨＩＰＳ樹脂：「４２４１」
（Ｔｏｔａｌ Ｐｅｔｒｏｃｈｅｍｉｃａｌｓ社製、
ＭＩ：４．０ｇ／１０ｍｉｎ．（２００℃、５．０ｋｇｆ）） The resin raw materials used in the examples are as follows.
(1) Polyolefin-based resin layer PP resin: “3080”
(Formosa Polypropylene Co., Ltd., MI: 8.5 g / 10 min. (190 ° C., 2.16 kgf), Block-PP)
(2) Oxygen barrier resin layer Ethylene-vinyl alcohol copolymer (EVOH) “EVAL J171B”
(Kuraray Co., Ltd., MI: 1.7 g / 10 min. (190 ° C., 2.16 kgf), ethylene content: 32 mol%)
(3) Adhesive layer Modified polyolefin polymer (modified PO) “Modic F502C”
(Mitsubishi Chemical Corporation, MI: 1.3 g / 10 min. (190 ° C., 2.16 kgf))
(4) Polystyrene resin layer HIPS resin: “4241”
(Total Petrochemicals,
MI: 4.0 g / 10 min. (200 ° C, 5.0 kgf))
　　この多層樹脂シートを下記条件にて加熱成形を行い、図３に示す容器を得た。
　　使用機器：浅野研究所社製　真空圧空成形機
　　加熱ヒーター：非接触式遠赤外線ヒーター
　　シート表面温度：シート構成により適宜シート表面温度を調整
　また、多層樹脂シート及び容器の各種評価を下記の方法で行った。結果を表１に示す。 The multilayer resin sheet was thermoformed under the following conditions to obtain a container shown in FIG.
Equipment used: Vacuum pressure forming machine manufactured by Asano Laboratories Heating heater: Non-contact far infrared heater Sheet surface temperature: Adjust sheet surface temperature as appropriate according to the sheet configuration In addition, various evaluations of multilayer resin sheets and containers are performed by the following methods. It was. The results are shown in Table 1.
（１）シートの反り評価
　図２に示すように、シートの流れ方向（ＭＤ）と幅方向（ＴＤ）に対して４５度の角度で、長さが１２０ｍｍとなる切れ目を入れた後、シートの最大の反り上がり高さを金尺を用いて測定した。 (1) Evaluation of sheet warpage As shown in FIG. 2, after making a break having a length of 120 mm at an angle of 45 degrees with respect to the flow direction (MD) and the width direction (TD) of the sheet, The maximum warped height was measured using a metal scale.
（２）容器の反り評価
　図３に示すように、１個あたりの寸法が横４４ｍｍ、縦５５ｍｍであり絞り比が０．５の容器を２０個多列式に成形した。その多列成形品のフランジ部が下方となるよう、平坦な面の上に静置した後、平坦面から容器／フランジ部の浮き上がった部分までの最大の高さを金尺を用いて測定した。 (2) Warpage evaluation of containers As shown in FIG. 3, 20 containers each having dimensions of 44 mm in width and 55 mm in length and a drawing ratio of 0.5 were formed in a multi-row manner. After standing on a flat surface so that the flange portion of the multi-row molded product is on the bottom, the maximum height from the flat surface to the raised portion of the container / flange portion was measured using a metal ruler. .
（３）耐油性評価
　シートの耐油性評価を図４に示す方法にて行った。
　幅１５ｍｍ、長さ２００ｍｍのシート試験片を固定治具の間に円弧状に歪がかかった状態で固定し、最上部に大豆油を浸したガーゼを置いた。この時、固定治具の幅は１３０ｍｍとなるように固定する。また、シートの側面から大豆油が入らないように注意する。経過日数ごとにガーゼに大豆油が乾燥しない程度に滴下し、３０日間連続でこの評価を実施し、シートの亀裂や破断の発生の有無につき以下の基準で判定を行った。
　　Ａ：亀裂や破断の発生が一切無し
　　Ｂ：僅かにシート表面に亀裂の発生が見られる
　　Ｃ：完全にシートの破断が発生し、折れた状態が確認される (3) Evaluation of oil resistance The oil resistance of the sheet was evaluated by the method shown in FIG.
A sheet test piece having a width of 15 mm and a length of 200 mm was fixed between the fixing jigs while being distorted in an arc shape, and gauze dipped in soybean oil was placed on the top. At this time, the fixing jig is fixed so that the width is 130 mm. Be careful not to allow soybean oil to enter from the side of the sheet. The soybean oil was dropped to the gauze so as not to dry every elapse of days, and this evaluation was carried out continuously for 30 days. The presence or absence of cracks or breakage of the sheet was determined according to the following criteria.
A: No cracks or breaks occur B: Cracks are slightly observed on the sheet surface C: The sheet breaks completely and the broken state is confirmed
（４）酸素透過率測定
　シートの酸素透過率を、以下の方法にて測定した。
［測定方法］　ＧＢ／Ｔ　１０３８準拠
　　使用機器：ＬａｂＴｈｉｎｋ社製　ＶＡＣ－Ｖ１
　　測定条件：２３℃×６５％Ｒ．Ｈ．
　　サンプルセット：基本的に、容器成形後の実用性を鑑みて、シートサンプルの下皮層側から酸素が透過するような向きにサンプルをセットする。 (4) Oxygen permeability measurement The oxygen permeability of the sheet was measured by the following method.
[Measurement method] GB / T 1038 compliant Device used: VAC-V1 manufactured by LabThink
Measurement conditions: 23 ° C. × 65% R.D. H.
Sample setting: Basically, in view of practicality after container molding, the sample is set in such a direction that oxygen can permeate from the lower skin layer side of the sheet sample.
（５）水蒸気透過率測定
　シートの水蒸気透過率を、以下の方法にて測定した。
［測定方法］　ＧＢ／Ｔ　１０３７準拠
　　使用機器：ＬａｂＴｈｉｎｋ社製　Ｗ３／０３１
　　測定条件：４０℃×９０％Ｒ．Ｈ． (5) Measurement of water vapor transmission rate The water vapor transmission rate of the sheet was measured by the following method.
[Measurement method] GB / T 1037 compliant Equipment used: W3 / 031 manufactured by LabThink
Measurement conditions: 40 ° C. × 90% R.D. H.
（６）成形性
　図３に挙げた容器用の成形金型を用い、熱成形する際の成形性を以下の基準で評価した。
　　Ａ：成形性良好
　　Ｂ：成形後の容器の一部に厚みの薄い箇所が見られる
　　Ｃ：成形金型通りの賦形性が得られていない。若しくは成形外観不良が見られる。
　＜実施例１＞ (6) Formability The moldability for thermoforming was evaluated according to the following criteria using the container mold shown in FIG.
A: Good moldability B: A portion with a small thickness is seen in a part of the molded container. C: Shapeability as in a molding die is not obtained. Or a molding appearance defect is seen.
<Example 1>
　３台の４５ｍｍ単軸押出機、１台の６５ｍｍ単軸押出機、１台の１０５ｍｍ単軸押出機を使用し、フィードブロック法により、ポリオレフィン系樹脂にＰＰ樹脂を用い、ポリオレフィン系樹脂層（１０）４０μｍ／接着層（１１ａ）１５μｍ／酸素バリア性樹脂層（１２）４０μｍ／接着層（１１ｂ）１５μｍ／ポリスチレン系樹脂層（１３）３４０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が９％、総厚が４５０μｍとなる多層樹脂シート得た。 Three 45mm single screw extruders, one 65mm single screw extruder, and one 105mm single screw extruder were used, and PP resin was used as polyolefin resin by a feed block method. ) 40 μm / adhesive layer (11a) 15 μm / oxygen barrier resin layer (12) 40 μm / adhesive layer (11b) 15 μm / polystyrene resin layer (13) 340 μm layer composition ratio of polyolefin resin layer Was 9% and a total thickness of 450 μm was obtained.
　上記のように得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表1に示すように、その水蒸気透過率が0．8ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表1に示すように、その酸素透過率が0．5ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが13mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。
＜実施例２＞ As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.8 g / m 2 · day. As a result of the oxygen permeability measurement, as shown in Table 1, the oxygen permeability is 0.5 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 13 mm. Further, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
<Example 2>
　ポリオレフィン系樹脂層（１０）１５０μｍ／接着層（１１ａ）１５μｍ／酸素バリア性樹脂層（１２）４０μｍ／接着層（１１ｂ）１５μｍ／ポリスチレン系樹脂層（１３）６８０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が１７％、総厚が９００μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin resin layer (10) 150 μm / adhesion layer (11a) 15 μm / oxygen barrier resin layer (12) 40 μm / adhesion layer (11b) 15 μm / polystyrene resin layer (13) 680 μm The layer composition ratio of the resin layer was 17%, the total thickness was 900 μm, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
　上記のように得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表1に示すように、その水蒸気透過率が0．7ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表1に示すように、その酸素透過率が0．4ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが15mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。
＜実施例３＞ As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.7 g / m 2 · day. As a result of measuring the oxygen permeability, as shown in Table 1, the oxygen permeability is 0.4 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 15 mm. Further, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
<Example 3>
　ポリオレフィン系樹脂層（１０）８０μｍ／接着層（１１ａ）１５μｍ／酸素バリア性樹脂層（１２）４０μｍ／接着層（１１ｂ）１５μｍ／ポリスチレン系樹脂層（１３）９５０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が７％、総厚が１１００μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin-based resin layer (10) 80 μm / adhesive layer (11a) 15 μm / oxygen barrier resin layer (12) 40 μm / adhesive layer (11b) 15 μm / polystyrene-based resin layer (13) 950 μm A multilayer resin sheet was obtained in the same manner as in Example 1 except that the resin layer had a layer composition ratio of 7% and a total thickness of 1100 μm.
　上記のように得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表1に示すように、その水蒸気透過率が0．7ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表1に示すように、その酸素透過率が0．6ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが9mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。
＜実施例４＞ As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.7 g / m 2 · day. As a result of the oxygen permeability measurement, as shown in Table 1, the oxygen permeability is 0.6 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank, and as a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 9 mm. Further, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
<Example 4>
　ポリオレフィン系樹脂層（１０）５０μｍ／接着層（１１ａ）１０μｍ／酸素バリア性樹脂層（１２）３０μｍ／接着層（１１ｂ）１０μｍ／ポリスチレン系樹脂層（１３）９００μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が５％、総厚が１０００μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin resin layer (10) 50 μm / adhesion layer (11a) 10 μm / oxygen barrier resin layer (12) 30 μm / adhesion layer (11b) 10 μm / polystyrene resin layer (13) 900 μm The layer composition ratio of the resin layer was 5%, the total thickness was 1000 μm, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
　上記のように得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表1に示すように、その水蒸気透過率が0．7ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表1に示すように、その酸素透過率が0．7ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが7mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。
＜実施例５＞ As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained as described above, as shown in Table 1, the water vapor transmission rate is 0.7 g / m 2 · day. As a result of measuring the oxygen transmission rate, as shown in Table 1, the oxygen transmission rate is 0.7 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 7 mm. Further, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
<Example 5>
　ポリオレフィン系樹脂層（１０）３０μｍ／接着層（１１ａ）２０μｍ／酸素バリア性樹脂層（１２）４０μｍ／接着層（１１ｂ）２０μｍ／ポリスチレン系樹脂層（１３）１０９０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が３％、総厚が１２００μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin-based resin layer (10) 30 μm / adhesive layer (11a) 20 μm / oxygen barrier resin layer (12) 40 μm / adhesive layer (11b) 20 μm / polystyrene-based resin layer (13) 1090 μm The layer composition ratio of the resin layer was 3%, the total thickness was 1200 μm, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
　上記のように得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表1に示すように、その水蒸気透過率が0．7ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表1に示すように、その酸素透過率が0．6ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが5mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。 To multilayer resin sheet obtained as described above, as a result of its water vapor transmission rate measurement, as shown in Table 1, the water vapor transmission rate is in the 0.7g / m 2 · day. As a result of the oxygen permeability measurement, as shown in Table 1, the oxygen permeability is 0.6 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 5 mm. Further, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
　上記実施例１～５ではポリオレフィン系樹脂にＰＰ樹脂を用いたが、ポリオレフィン系樹脂に、例えばエチレン、プロピレン、ブテン－１等の炭素数２～８程度のポリオレフィンの単独重合体などいずれか１の樹脂を用いてもよい。この場合、実施例１～５の効果とほぼ同様な効果を得ることができる。 In Examples 1 to 5, PP resin was used as the polyolefin resin. However, the polyolefin resin may be any one of, for example, a homopolymer of a polyolefin having about 2 to 8 carbon atoms such as ethylene, propylene, and butene-1. A resin may be used. In this case, substantially the same effects as those of the first to fifth embodiments can be obtained.
　一方、実施例１に比べ、ポリオレフィン系樹脂層の合計厚みや表皮層となるポリスチレン系樹脂層の厚みなどを小さくさせたり、水蒸気バリア性樹脂層をポリスチレン系樹脂層にて形成させたりする変更例を比較例としてそれぞれの性能について以下のように評価した。
＜比較例１＞ On the other hand, compared with Example 1, the modification which makes the total thickness of a polyolefin-type resin layer, the thickness of the polystyrene-type resin layer used as a skin layer, etc. small, or forms a water vapor | steam barrier resin layer in a polystyrene-type resin layer. As a comparative example, each performance was evaluated as follows.
<Comparative Example 1>
　１台の６５ｍｍ単軸押出機により、ポリスチレン系樹脂層４５０μｍという単層構成のシートを得た。実施例１に比べ、本比較例の特徴は樹脂シートがポリスチレン系樹脂層のみの単層で構成されている。 A single-layer sheet having a polystyrene resin layer of 450 μm was obtained with one 65 mm single-screw extruder. Compared with Example 1, the characteristic of this comparative example is that the resin sheet is composed of a single layer composed of only a polystyrene-based resin layer.
　当該比較例から得た単層樹脂シートに対し、その水蒸気透過率測定を行った結果、表２に示すように、その水蒸気透過率が7．0ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表２に示すように、その酸素透過率が350ｃｃ／ｍ２・ｄａｙである。また、当該単層樹脂シートの耐油性を評価したところ、耐油性がCランクと評価され、当該単層樹脂シートのそりに対して評価した結果、単層樹脂シートのそりが12mmとなる。さらに、当該単層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。 As a result of measuring the water vapor transmission rate of the single layer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 7.0 g / m 2 · day. As a result of measuring the oxygen transmission rate, as shown in Table 2, the oxygen transmission rate is 350 cc / m 2 · day. Further, when the oil resistance of the single layer resin sheet was evaluated, the oil resistance was evaluated as C rank, and as a result of evaluating the warp of the single layer resin sheet, the warp of the single layer resin sheet was 12 mm. Furthermore, when the moldability of a container molded using the single-layer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
　それぞれの評価基準に照らしたところ、酸素透過率が１０ｃｃ／ｍ２・ｄａｙより遥かに大きいとともに、耐油性の評価では完全にシートの破断が発生し、折れた状態が確認されたため、耐油性では不合格である。
＜比較例２＞ In light of the respective evaluation criteria, the oxygen permeability was far greater than 10 cc / m 2 · day, and the oil resistance evaluation completely caused the sheet to break and the broken state was confirmed. Fail.
<Comparative Example 2>
　表皮層がポリスチレン系樹脂から構成されている以外、他の方法は実施例１と同様として多層樹脂シートを得た。 A multilayer resin sheet was obtained in the same manner as in Example 1 except that the skin layer was made of polystyrene resin.
　当該比較例から得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表２に示すように、その水蒸気透過率が4．2ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表２に示すように、その酸素透過率が1．2ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がCランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが15mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がAランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0となっている。 As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 4.2 g / m 2 · day. As a result of measuring the oxygen transmission rate, as shown in Table 2, the oxygen transmission rate is 1.2 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as C rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 15 mm. Further, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as A rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0. It has become.
　それぞれの評価基準に照らしたところ、耐油性の評価では完全にシートの破断が発生し、折れた状態が確認されたため、耐油性は不合格である。
＜比較例３＞ In light of the respective evaluation criteria, in the oil resistance evaluation, the sheet was completely broken and the folded state was confirmed, so the oil resistance was unacceptable.
<Comparative Example 3>
　ポリオレフィン系樹脂層（１０）２００μｍ／接着層（１１ａ）１５μｍ／酸素バリア性樹脂層（１２）４０μｍ／接着層（１１ｂ）１５μｍ／ポリスチレン系樹脂層（１３）３３０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が３３％、総厚が６００μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin-based resin layer (10) 200 μm / adhesive layer (11a) 15 μm / oxygen barrier resin layer (12) 40 μm / adhesive layer (11b) 15 μm / polystyrene-based resin layer (13) 330 μm A multilayer resin sheet was obtained in the same manner as in Example 1 except that the layer composition ratio of the resin layer was 33% and the total thickness was 600 μm.
　当該比較例から得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表２に示すように、その水蒸気透過率が0．7ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表２に示すように、その酸素透過率が0．8ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが43mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がCランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが12mmとなっている。 As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 0.7 g / m 2 · day. As a result of measuring the oxygen transmission rate, as shown in Table 2, the oxygen transmission rate is 0.8 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank. As a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 43 mm. Furthermore, when the moldability of the container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as C rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 12 mm. It has become.
　それぞれの評価基準に照らしたところ、多層樹脂シートのそりが43mmであり、当該多層樹脂シートを用いて成形される容器の反りが12mmとなっているため、従来技術の課題を解決していない。また、成形性に対する評価の結果、成形金型通りの賦形性が得られていないため、成形した容器は不合格である。
＜比較例４＞ In light of the respective evaluation criteria, the warp of the multilayer resin sheet is 43 mm, and the warpage of the container molded using the multilayer resin sheet is 12 mm. In addition, as a result of the evaluation of the moldability, the molded container is not acceptable because the moldability as in the mold is not obtained.
<Comparative Example 4>
　ポリオレフィン系樹脂層（１０）２５μｍ／接着層（１１ａ）１０μｍ／酸素バリア性樹脂層（１２）３０μｍ／接着層（１１ｂ）１０μｍ／ポリスチレン系樹脂層（１３）１２０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が１３％、総厚が１９５μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin-based resin layer (10) 25 μm / adhesive layer (11a) 10 μm / oxygen barrier resin layer (12) 30 μm / adhesive layer (11b) 10 μm / polystyrene-based resin layer (13) 120 μm The layer composition ratio of the resin layer was 13%, the total thickness was 195 μm, and other methods were obtained in the same manner as in Example 1 to obtain a multilayer resin sheet.
　当該比較例から得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表２に示すように、その水蒸気透過率が0．9ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表２に示すように、その酸素透過率が1．0ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが11mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がBランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0mmとなっている。 As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 0.9 g / m 2 · day. As a result of the oxygen permeability measurement, as shown in Table 2, the oxygen permeability is 1.0 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank, and as a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 11 mm. Furthermore, when the moldability of a container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as B rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0 mm. It has become.
　それぞれの評価基準に照らしたところ、成形性がBランクと評価されたため、使用中において、成形後の容器における厚みの薄い箇所が破れて、水蒸気または酸素の侵入によってバリア性が低下してしまう恐れがある。
＜比較例５＞ In light of each evaluation standard, the formability was evaluated as B rank, and during use, the thin part of the container after molding may be broken, and the barrier property may be reduced due to the intrusion of water vapor or oxygen There is.
<Comparative Example 5>
　ポリオレフィン系樹脂層（１０）４０μｍ／接着層（１１ａ）１５μｍ／酸素バリア性樹脂層（１２）４０μｍ／接着層（１１ｂ）１５μｍと下皮層が表皮層と同一の樹脂を用いたポリオレフィン系樹脂層３４０μｍという層構成を有し、ポリオレフィン系樹脂層の層構成比率が８４％、総厚が４５０μｍ、他の方法は実施例１と同様の方法で多層樹脂シートを得た。 Polyolefin-based resin layer (10) 40 μm / adhesive layer (11a) 15 μm / oxygen barrier resin layer (12) 40 μm / adhesive layer (11b) 15 μm and lower-layer resin layer 340 μm using the same resin as the skin layer A multilayer resin sheet was obtained in the same manner as in Example 1 except that the polyolefin resin layer had a layer composition ratio of 84% and a total thickness of 450 μm.
　当該比較例から得た多層樹脂シートに対し、その水蒸気透過率測定を行った結果、表２に示すように、その水蒸気透過率が0．7ｇ／ｍ２・ｄａｙとなっている。また、その酸素透過率測定を行った結果、表２に示すように、その酸素透過率が0．8ｃｃ／ｍ２・ｄａｙである。また、当該多層樹脂シートの耐油性を評価したところ、耐油性がAランクと評価され、当該多層樹脂シートのそりに対して評価した結果、多層樹脂シートのそりが9mmとなる。さらに、当該多層樹脂シートを用いて成形される容器の成形性を評価したところ、成形性がBランクと評価され、当該成形容器の反りに対して評価した結果、当該成形容器の反りが0mmとなっている。 As a result of measuring the water vapor transmission rate of the multilayer resin sheet obtained from the comparative example, as shown in Table 2, the water vapor transmission rate is 0.7 g / m 2 · day. As a result of measuring the oxygen transmission rate, as shown in Table 2, the oxygen transmission rate is 0.8 cc / m 2 · day. Further, when the oil resistance of the multilayer resin sheet was evaluated, the oil resistance was evaluated as A rank, and as a result of evaluating the warpage of the multilayer resin sheet, the warpage of the multilayer resin sheet was 9 mm. Furthermore, when the moldability of a container molded using the multilayer resin sheet was evaluated, the moldability was evaluated as B rank, and as a result of evaluating the warpage of the molded container, the warpage of the molded container was 0 mm. It has become.
　それぞれの評価基準に照らしたところ、成形性がBランクと評価されたため、使用中において、成形後の容器における厚みの薄い箇所が破れて、水蒸気または酸素の侵入によってバリア性が低下してしまう恐れがある。 In light of each evaluation standard, the formability was evaluated as B rank, and during use, the thin part of the container after molding may be broken, and the barrier property may be reduced due to the intrusion of water vapor or oxygen There is.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　上記実施例１～３及び比較例１～５の結果によれば、表皮層となるポリプロピレンおよびポリエチレンを含むポリオレフィン系樹脂層と、接着層と、酸素バリア性樹脂層と、下皮層となるポリスチレン系樹脂層を含む樹脂層とから形成されてなり、シート全体の厚みを２００～１３００μｍとし、ポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を１％～３０％とするように複数の樹脂層を積層して形成される多層樹脂シートは、優れた熱成形性、耐油性をあわせ持ち、シートの反りを抑制することができる。 According to the results of Examples 1 to 3 and Comparative Examples 1 to 5, the polyolefin resin layer containing polypropylene and polyethylene as the skin layer, the adhesive layer, the oxygen barrier resin layer, and the polystyrene resin as the lower skin layer. A plurality of resin layers including a resin layer, the thickness of the entire sheet is 200 to 1300 μm, and the thickness of the polyolefin resin layer is 1% to 30% with respect to the thickness of the entire sheet. A multilayer resin sheet formed by laminating resin layers has excellent thermoformability and oil resistance, and can suppress warpage of the sheet.
　また、前記酸素バリア性樹脂層の厚みが１０～５０μｍであり、酸素透過率が１０ｃｃ／ｍ２・ｄａｙ以下である。 The oxygen barrier resin layer has a thickness of 10 to 50 μm and an oxygen permeability of 10 cc / m 2 · day or less.
　さらに、上記の構成を有する多層樹脂シートはその水蒸気透過率が１０ｇ／ｍ２・ｄａｙ以下である。 Furthermore, the multilayer resin sheet having the above configuration has a water vapor transmission rate of 10 g / m 2 · day or less.
　従って、上記のように構成された多層樹脂シートによれば、優れた熱成形性、酸素バリア性、水蒸気バリア性、耐油性をあわせ持ち、シートの反りを抑制することができる。 Therefore, according to the multilayer resin sheet configured as described above, it has excellent thermoformability, oxygen barrier property, water vapor barrier property, and oil resistance, and can suppress warpage of the sheet.
　また、上記のように構成した多層樹脂シートを成形してなる成形容器は優れた熱成形性、酸素バリア性、水蒸気バリア性、耐油性をあわせ持ち、且つ、熱成形後の反りを抑制することができる。 In addition, the molded container formed by molding the multilayer resin sheet configured as described above has excellent thermoformability, oxygen barrier property, water vapor barrier property, oil resistance, and suppresses warping after thermoforming. Can do.

Claims (6)

  1. 　複数の樹脂層を積層して形成される多層樹脂シートであって、表皮層となるポリオレフィン系樹脂層と、接着層と、酸素バリア性樹脂層と、下皮層となるポリスチレン系樹脂層を含む樹脂層とから形成されてなり、シート全体の厚みを２００～１３００μｍとし、ポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を１%～３０％とすることを特徴とする多層樹脂シート。 A multilayer resin sheet formed by laminating a plurality of resin layers, which includes a polyolefin-based resin layer serving as a skin layer, an adhesive layer, an oxygen barrier resin layer, and a polystyrene-based resin layer serving as a lower skin layer A multilayer resin sheet, wherein the thickness of the entire sheet is 200 to 1300 μm, and the thickness of the polyolefin resin layer is 1% to 30% of the layer composition ratio to the total thickness of the sheet.
  2. 　ポリオレフィン系樹脂層がブロックポリプロピレン樹脂からなることを特徴とする請求項１に記載の多層樹脂シート。 The multilayer resin sheet according to claim 1, wherein the polyolefin resin layer is made of a block polypropylene resin.
  3. 　前記ポリオレフィン系樹脂層の厚みがシート全体の厚みに対する層構成比率を５％以上１０％未満とすることを特徴とする請求項１または２に記載の多層樹脂シート。 The multilayer resin sheet according to claim 1 or 2, wherein the thickness of the polyolefin-based resin layer is such that the layer composition ratio with respect to the thickness of the entire sheet is 5% or more and less than 10%.
  4. 　酸素バリア性樹脂層の厚みが１０～５０μｍであり、酸素透過率が１０ｃｃ／ｍ２・ｄａｙ以下であることを特徴とする請求項３に記載の多層樹脂シート。 4. The multilayer resin sheet according to claim 3, wherein the oxygen barrier resin layer has a thickness of 10 to 50 μm and an oxygen permeability of 10 cc / m 2 · day or less.
  5. 　水蒸気透過率が１０ｇ／ｍ２・ｄａｙ以下であることを特徴とする請求項４に記載の多層樹脂シート。 Multilayer resin sheet according to claim 4, water vapor transmission rate is equal to or less than 10g / m 2 · day.
  6. 　請求項１～５のいずれか１項に記載の多層樹脂シートをポリオレフィン系樹脂層が容器の内面に位置するよう熱成形してなることを特徴とする成形容器。 A molded container obtained by thermoforming the multilayer resin sheet according to any one of claims 1 to 5 so that the polyolefin-based resin layer is positioned on the inner surface of the container.
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WO2021111815A1 (en) * 2019-12-03 2021-06-10 デンカ株式会社 Multilayer resin sheet and molding container
WO2022054567A1 (en) * 2020-09-11 2022-03-17 デンカ株式会社 Multilayer resin sheet and molded container

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JPH10315370A (en) * 1997-05-19 1998-12-02 Daicel Chem Ind Ltd Laminate, sheet for molding laminate, and container
JP2006021409A (en) * 2004-07-07 2006-01-26 Idemitsu Unitech Co Ltd Laminated sheet, container comprising it and container manufacturing method
JP2006181797A (en) * 2004-12-27 2006-07-13 Dainippon Ink & Chem Inc Re-sealable coextrusion multilayered film and re-sealable laminated film
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WO2014087695A1 (en) * 2012-12-07 2014-06-12 電気化学工業株式会社 Water-repellent, thermoplastic resin sheet, and molded article

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JPH10315370A (en) * 1997-05-19 1998-12-02 Daicel Chem Ind Ltd Laminate, sheet for molding laminate, and container
JP2006021409A (en) * 2004-07-07 2006-01-26 Idemitsu Unitech Co Ltd Laminated sheet, container comprising it and container manufacturing method
JP2006181797A (en) * 2004-12-27 2006-07-13 Dainippon Ink & Chem Inc Re-sealable coextrusion multilayered film and re-sealable laminated film
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Publication number Priority date Publication date Assignee Title
WO2021111815A1 (en) * 2019-12-03 2021-06-10 デンカ株式会社 Multilayer resin sheet and molding container
WO2022054567A1 (en) * 2020-09-11 2022-03-17 デンカ株式会社 Multilayer resin sheet and molded container

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