Resin composition, resin sheet, laminate, package, and method for manufacturing package

Abstract

To provide a resin composition that can achieve a resin sheet having excellent transparency and also having high impact resistance while containing petroleum resin.SOLUTION: A resin composition contains polypropylene having smectic crystals, and petroleum resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a resin sheet, a laminate, a package, and a method for producing a package. [Background technology]

[0002] Resin packaging is widely used as packaging containers for food and pharmaceuticals, but in recent years, there has been a strong demand for reducing the amount of fossil fuel-derived resin used in order to be environmentally friendly. While one approach to this demand is to replace all or part of the resin with biomass-derived resin raw materials, it is preferable to reduce the amount of resin used itself from the perspective of reducing carbon dioxide emissions during incineration. On the other hand, simply reducing the amount of resin used may result in a decrease in rigidity, making the material unsuitable for use. Therefore, a method of adding petroleum resin to improve rigidity is known (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 8-157659 [Patent Document 2] Patent Publication No. 2008-87829 Summary of the Invention [Problem to be solved by the invention]

[0004] However, sheets obtained by adding petroleum resins have a problem of poor impact resistance. An object of the present invention is to provide a resin composition that can realize a resin sheet having excellent transparency and high impact resistance despite containing a petroleum resin. [Means for solving the problem]

[0005] As a result of extensive research, the present inventors have found that the above problems can be solved by combining a petroleum resin with polypropylene having smectic crystals, and have thus completed the present invention. According to the present invention, the following resin compositions and the like are provided. 1. A resin composition comprising polypropylene having smectic crystals and a petroleum resin. 2. The resin composition according to 1, wherein the polypropylene has an isotactic pentad fraction of 80 mol % or more and 99 mol % or less. 3. The crystallization rate of the polypropylene at 130°C is 2.5 min -1 3. The resin composition according to 1 or 2, which is: 4. The resin composition according to any one of 1 to 3, wherein the content of the petroleum resin is 1% by mass or more and 20% by mass or less. 5. The resin composition according to any one of 1 to 4, which is substantially free of a nucleating agent. 6. A resin sheet comprising the resin composition according to any one of 1 to 5. 7. The resin sheet according to 6, having an internal haze of 15% or less. 8. A laminate comprising the resin sheet according to 6 or 7. 9. The laminate according to 8, wherein a second layer containing polypropylene having smectic crystals is laminated on at least one surface of the resin sheet. 10. The laminate according to 9, wherein the second layer contains a petroleum resin. 11. The laminate according to 8, wherein a second layer containing polypropylene and a nucleating agent is laminated on at least one surface of the resin sheet. 12. The laminate according to any one of 8 to 11, having a thickness of 100 μm or more and 2000 μm or less. 13. A packaging body produced using the resin sheet according to 6 or 7 or the laminate according to any one of 8 to 12. 14. A packaging body having at least one layer containing polypropylene having smectic crystals and petroleum resin, The polypropylene has an isotactic pentad fraction of 80 mol% or more and 99 mol% or less, The content of the petroleum resin in the layer is 1% by mass or more and 20% by mass or less. packaging. 15. A package according to 13 or 14, having a buckling strength of 20N or more as measured in accordance with JIS K7181 under the following conditions: Measurement sample shape: flange outer dimensions 125mm x 125mm, flange inner dimensions 104mm x 104mm, top outer dimensions: 74mm x 74mm, depth 12mm Measurement conditions: Test environment 23°C ± 2°C, 50% RH ± 10% RH, test speed 10 mm / min Calculation method: Calculate the maximum load at a compressive displacement of 2 mm or less and use this as the buckling strength. 16. A method for producing a packaging body, comprising heat-molding the resin sheet according to 6 or 7 or the laminate according to any one of 8 to 12 at a temperature equal to or lower than the melting point of the polypropylene. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a resin composition that can realize a resin sheet having excellent transparency and high impact resistance despite containing a petroleum resin. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram illustrating an example of a manufacturing apparatus for manufacturing a resin sheet of the present invention. [Figure 2] 1 is a photograph showing the shape of a measurement sample used in evaluating the buckling strength in Examples 2 to 4. [Figure 3] 1 is a photograph of resin sheets after film impact evaluation (impact resistance test) in Example 2 and Comparative Example 1. In the figure, Example 2 is on the right and Comparative Example 1 is on the left. [Figure 4] FIG. 1 is a schematic diagram of a manufacturing apparatus used to manufacture a laminate of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0008] The resin composition, resin sheet, laminate, package, and method for manufacturing the package according to the present invention will be described below. In this specification, "x to y" represents a numerical range of "x or more, y or less." When there are multiple lower limit values, such as "x or more," or multiple upper limit values, such as "y or less," for a single technical feature, any combination of upper and lower limit values ​​can be selected.

[0009] 1.Resin composition A resin composition according to one embodiment of the present invention comprises polypropylene having Smectica crystals and a petroleum resin. Smectica crystals are a metastable mesophase with small individual domain sizes. Polypropylene having Smectica crystals already has excellent transparency, and combining it with a petroleum resin can further improve transparency. Furthermore, while adding a petroleum resin to a resin sheet generally significantly reduces impact resistance, the resin sheet obtained from a resin composition according to one embodiment of the present invention exhibits excellent impact resistance, despite the inclusion of a petroleum resin. While the mechanism is not entirely clear, it is believed to be due to the fine crystalline structure derived from the Smectica crystals. Because the resin sheet obtained from the resin composition according to one embodiment of the present invention has excellent impact resistance, it reduces film-forming problems such as breakage during film formation or breakage due to slitting to a specified width, thereby achieving stable film formation. Furthermore, as described below, by thermoforming the resin sheet, a molded product (packaging product) with high rigidity and excellent transparency can be obtained. Each component used in the resin composition will now be described.

[0010] (polypropylene) Polypropylene is a polymer containing at least propylene. Specific examples include homopolypropylene and copolymers of propylene and olefin. Homopolypropylene is particularly preferred for its heat resistance and hardness.

[0011] The polypropylene used in the resin composition according to one embodiment of the present invention contains Smectic crystals. As described above, Smectic crystals are a metastable mesophase, and have excellent transparency due to the small domain size of each domain. Furthermore, since Smectic crystals are metastable, they soften into a sheet with a lower amount of heat than α crystals, which are highly crystallized, and are therefore preferred for their excellent moldability. The crystalline structure of polypropylene may include, in addition to smectic crystals, other crystalline forms such as α crystals, β crystals, γ crystals, and amorphous portions. For example, 30% by mass or more, 50% by mass or more, 70% by mass or more, or 90% by mass or more of the polypropylene in the resin sheet may be smectic crystals. The specific method for confirming the crystal structure is as described in the Examples below.

[0012] In one embodiment of the present invention, the polypropylene preferably has an isotactic pentad fraction of 80 mol % or more. If the isotactic pentad fraction is 80 mol % or more, sufficient rigidity can be obtained when the resin sheet is made. The isotactic pentad fraction of the polypropylene is preferably 85 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more, and is preferably 99 mol% or less, and even more preferably 98.5 mol% or less. When the isotactic pentad fraction is 80 mol % or more and 99 mol % or less, when the resin is made into a resin sheet, it is possible to obtain excellent rigidity and sufficient transparency. The isotactic pentad fraction is preferably 80 mol % or more and 99 mol % or less, more preferably 85 mol % or more and 99 mol % or less, and even more preferably 90 mol % or more and 98.5 mol % or less.

[0013] The isotactic pentad fraction is the isotactic fraction of pentad units (five consecutive propylene monomers isotactically bonded) in the molecular chain of the resin composition. This fraction can be measured by, for example, the method described in Macromolecules, Vol. 8 (1975), p. 687. 13 It can be measured by C-NMR. A specific method for measuring the isotactic pentad fraction is as described in the Examples below.

[0014] The copolymer of propylene and olefin may be a block copolymer or a random copolymer, or a mixture thereof, so long as the isotactic pentad fraction is 80 mol % or more (preferably 80 to 99 mol %). Examples of the olefin include ethylene, butylene, and cycloolefin.

[0015] In one embodiment of the present invention, the melt flow rate (hereinafter sometimes referred to as "MFR") of the polypropylene is preferably 0.5 g / 10 min or more, more preferably 1 g / 10 min or more, and even more preferably 2 g / 10 min or more. It is also preferably 10 g / 10 min or less, more preferably 8 g / 10 min or less, and even more preferably 6 g / 10 min or less. Within this range, excellent moldability into a film or sheet is achieved. The MFR of polypropylene is measured in accordance with JIS-K7210 at a measurement temperature of 230°C and a load of 2.16 kg.

[0016] In one embodiment of the present invention, the crystallization rate of polypropylene at 130°C is 2.5 min -1 It is preferable that the time is 2.0 min or less. -1 More preferably, it is: Crystallization speed is 2.5 min -1 If it is less than this, deterioration of the design can be prevented. The lower limit is not particularly limited, but is usually 0.01 min -1 More than 0.05min-1 It is preferable that this is equal to or greater than this. The specific method for measuring the crystallization rate is as described in the Examples.

[0017] In one embodiment of the present invention, the resin composition is preferably substantially free of or free of a nucleating agent. Even when a nucleating agent is contained, the amount is preferably small, for example, 1.0 mass % or less, 0.5 mass % or less, 0.1 mass % or less, 0.01 mass % or less, or 0.001 mass % or less of the resin composition, and for example, 1.0 mass % or less, 0.5 mass % or less, 0.1 mass % or less, 0.01 mass % or less, or 0.001 mass % or less relative to the amount of polypropylene. Examples of the nucleating agent include sorbitol-based crystal nucleating agents, and commercially available products include Gelall MD (Shin-Nihon Rikagaku Co., Ltd.) and Rikemaster FC-1 (Riken Vitamin Co., Ltd.).

[0018] In one embodiment, the crystallization rate of polypropylene without the addition of a nucleating agent is increased to 2.5 min -1 or less and cooled at 80° C. / second or more to form the above-mentioned smectic crystals, a resin sheet using the resin composition can have excellent transparency.

[0019] The isotactic pentad fraction is 80 mol% or more and 99 mol% or less, and the crystallization rate of polypropylene is 2.5 min -1 In the following, in order to obtain a resin sheet having excellent transparency and gloss, it is usually necessary to form smectic crystals. By heating the resin sheet, the polypropylene in the resin sheet transforms to α crystal while maintaining the microstructure derived from the smectic crystal. However, the polypropylene in the molded product (packaging) has an isotactic pentad fraction of 85 mol% or more and 99 mol% or less and the crystallization rate of the polypropylene is 2.5 min -1 If it is below this, it can be said to be derived from smectite crystals.

[0020] By calculating the scattering intensity distribution and long period using small-angle X-ray scattering analysis, it is possible to determine whether a resin sheet has been obtained by cooling at 80°C / sec or more. In other words, the above analysis makes it possible to determine whether a resin sheet has a microstructure derived from smectic crystals. The measurement is performed under the following conditions. The X-ray generator used is the ultraX 18HF (manufactured by Rigaku Corporation), and an imaging plate is used to detect scattering. ·Light source wavelength: 0.154nm Voltage / Current: 50kV / 250mA Irradiation time: 60 minutes Camera length: 1.085m -Sample thickness: Stack the sheets so that they are 1.5 to 2.0 mm. Stack the sheets so that the film formation (MD) direction is aligned. In order to shorten the measurement time, the sheets are stacked to a distance of 1.5 to 2.0 mm, but if the measurement time is extended, it is possible to measure with just one sheet without stacking the sheets.

[0021] In one embodiment of the present invention, the polypropylene preferably has an exothermic peak (also referred to as a "low-temperature exothermic peak") of 1 J / g or more, preferably 1.5 J / g or more, on the low-temperature side of the maximum endothermic peak in a curve (DSC curve) obtained by differential scanning calorimetry (DSC). The upper limit is not particularly limited, but is usually 10 J / g or less.

[0022] In one embodiment of the present invention, the polypropylene content in the resin composition is usually 75% by mass or more, preferably 80% by mass or more, more preferably 87% by mass or more, and usually 99% by mass or less, preferably 95% by mass or less.

[0023] (petroleum resin) Examples of petroleum resins include dicyclopentadiene resins obtained by thermally polymerizing cyclopentadiene fractions; aromatic (C9) petroleum resins obtained by cationic polymerization of a mixture of aromatic olefins having 9 carbon atoms; aliphatic (C5) petroleum resins obtained by cationic polymerization of a mixture of chain olefins having 5 carbon atoms; styrene resins; alkylphenol resins; and xylene resins. Other examples include copolymers of at least two of the monomers of the above resins; petroleum resins obtained by acid-modifying the above petroleum resins or copolymers; petroleum resins obtained by hydrogenating the above petroleum resins or copolymers; and mixtures of at least two of the above-mentioned components.

[0024] As the petroleum resin, from the viewpoints of transparency and moldability, a copolymer petroleum resin containing an aromatic component is preferred, and a copolymer petroleum resin of an aromatic component and dicyclopentadiene is more preferred.

[0025] The softening point of the petroleum resin is preferably 50 to 170°C, and more preferably 100 to 160°C. If the softening point is less than 50°C, heat resistance decreases and the resin component tends to bleed out to the surface in a high-temperature atmosphere. If the softening point exceeds 170°C, the melting point of the polypropylene polymer is exceeded, which tends to make it difficult to impart the sheet softening effect in the molding temperature range where the molded product does not whiten, and there is a concern that transparency may be impaired. The softening point is measured by a method in accordance with JIS K2207.

[0026] The number average molecular weight of the petroleum resin is more preferably 600 or more and 1000 or less. If the number average molecular weight is less than 600, the heat resistance decreases and the resin component tends to bleed out to the surface in a high-temperature atmosphere. On the other hand, if it exceeds 1000, the melting point of the polypropylene polymer is exceeded, so it becomes difficult to impart the sheet softening effect in the molding temperature range where the molded product does not whiten, and there is a concern that transparency will be reduced. The number average molecular weight of the petroleum resin is more preferably 650 or more, and particularly preferably 700 or more. The number average molecular weight is a value calculated as polystyrene measured by gel permeation chromatography (GPC).

[0027] In one embodiment of the present invention, the content of the petroleum resin in the resin composition is usually 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, and usually 20% by mass or less, preferably 15% by mass or less, more preferably 12% by mass or less.

[0028] (Other ingredients) In the resin composition according to one aspect of the present invention, other resin components or additives may be added in addition to the polypropylene and petroleum resin described above. Examples of other resin components include polypropylene other than the above-mentioned polypropylene, polyethylene, etc. Furthermore, when environmental friendliness is taken into consideration, a resin raw material derived from biomass (for example, biopolypropylene, biopolyethylene, etc.) may be added. Among polyethylenes, linear low-density polyethylene (LLDPE) is expected to further enhance transparency, and can also be made into bio-polyethylene, making it environmentally friendly.

[0029] The resin composition according to one embodiment of the present invention preferably contains substantially no inorganic compounds such as inorganic fillers, since the inclusion of such components may impair transparency. Even when an inorganic compound such as an inorganic filler is contained, the amount is preferably small, for example, 1.0 mass % or less, 0.5 mass % or less, 0.1 mass % or less, 0.01 mass % or less, or 0.001 mass % or less of the resin composition, and for example, 1.0 mass % or less, 0.5 mass % or less, 0.1 mass % or less, 0.01 mass % or less, or 0.001 mass % or less relative to the amount of polypropylene.

[0030] In one embodiment of the present invention, 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 85% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, 99.8% by mass or more, 99.9% by mass or more, 99.99% by mass or more, or 100% by mass of the resin composition is polypropylene having Smectic crystals and petroleum resin; or polypropylene having Smectic crystals, petroleum resin, and other components.

[0031] 2. Resin sheet A resin sheet according to one aspect of the present invention is produced using the resin composition of the present invention described above, and can also be said to contain the resin composition. In principle, the composition of the resin composition of the present invention described above is reflected in the resin sheet as is.

[0032] The resin sheet according to one embodiment of the present invention has excellent transparency due to the combination of polypropylene having smectic crystals with a petroleum resin. Furthermore, despite the inclusion of the petroleum resin, the resin sheet exhibits excellent impact resistance, reduces the risk of film formation problems such as breakage during sheet formation, and is easy to handle.

[0033] The type, content and other conditions of each component in the resin sheet according to one embodiment of the present invention are the same as those explained in "1. Resin composition."

[0034] The thickness of the resin sheet according to one embodiment of the present invention is usually 100 μm or more, preferably 150 μm or more, and more preferably 200 μm or more, and is usually 1200 μm or less, and preferably 1000 μm or less.

[0035] The resin sheet according to one aspect of the present invention preferably has a tensile modulus (MD direction) of 1400 MPa or more and 2200 MPa or less. The resin sheet according to one aspect of the present invention preferably has a tensile modulus (TD direction) of 1400 MPa or more and 2200 MPa or less. The tensile modulus is measured by the method described in the examples.

[0036] The resin sheet according to one aspect of the present invention preferably has a yield strength (MD direction) of 23 MPa or more and 36 MPa or less. The resin sheet according to one aspect of the present invention preferably has a yield strength (TD direction) of 23 MPa or more and 36 MPa or less. The yield strength is measured by the method described in the Examples.

[0037] The resin sheet according to one aspect of the present invention preferably has a breaking strength (MD direction) of 38 MPa or more and 50 MPa or less. The resin sheet according to one aspect of the present invention preferably has a breaking strength (TD direction) of 34 MPa or more and 50 MPa or less. The breaking strength is measured by the method described in the examples.

[0038] The resin sheet according to one aspect of the present invention preferably has a breaking elongation (MD direction) of 300% or more and 550% or less. The resin sheet according to one aspect of the present invention preferably has a breaking elongation (TD direction) of 300% or more and 550% or less. The breaking elongation is measured by the method described in the examples.

[0039] The resin sheet according to one embodiment of the present invention preferably has a total haze of 20% or less, more preferably 15% or less, 10% or less, and even more preferably 5% or less. The resin sheet according to one embodiment of the present invention preferably has an internal haze of 15% or less, more preferably 10% or less, and even more preferably 5% or less. The haze is measured by the method described in the examples.

[0040] The resin sheet according to one aspect of the present invention preferably has a total light transmittance of 85% or more, and more preferably 90% or more. The total light transmittance is measured by the method described in the examples.

[0041] The resin sheet according to one aspect of the present invention preferably has a glossiness of 120% or more and 150% or less. The glossiness is measured by the method described in the examples.

[0042] The resin sheet according to one aspect of the present invention preferably has an impact strength (film impact) of 1500 J / m or more and 17000 J / m or less. The impact strength is measured by the method described in the examples.

[0043] 3. Manufacturing method of resin sheet The method for producing the resin sheet of the present invention is not particularly limited, and examples thereof include an extrusion method. The extrusion method involves cooling a melt of the resin composition of the present invention (hereinafter referred to as the molten resin), and the cooling is preferably carried out at a cooling rate of 80°C / sec or more until the internal temperature of the resin sheet falls below the crystallization temperature. This allows the crystalline structure of the polypropylene contained in the resin sheet to become the Smectic crystal structure described above. The cooling rate is more preferably 90°C / sec or more, and even more preferably 150°C / sec or more. The specific production method will be described in detail in the Examples.

[0044] 4.Laminate The resin sheet according to the embodiment of the present invention described above may be used to form a laminate. The configuration of the laminate is not particularly limited as long as it contains the above-mentioned resin sheet (hereinafter also referred to as "substrate layer"), and may be a laminate structure of two or more layers. It may also contain multiple substrate layers, such as "substrate layer / substrate layer," "substrate layer / substrate layer / substrate layer," "substrate layer / barrier layer / substrate layer," or "substrate layer / adhesive layer / barrier layer / adhesive layer / substrate layer," as described below. When multiple substrate layers are contained, the multiple substrate layers may have the same or different compositions. Furthermore, the multiple substrate layers may have the same or different thicknesses.

[0045] Examples of other layers used in the laminate according to one embodiment of the present invention include a highly transparent layer, a barrier layer, an anti-fogging layer, and an adhesive layer.

[0046] The highly transparent layer is a layer used to further increase the transparency of the laminate. Examples of highly transparent layers include layers made of polypropylene (preferably homopolypropylene) to which high MFR polypropylene (for example, MFR is 2 g / 10 min or more, preferably 4 g / 10 min, more preferably 6 g / 10 min or more, and even more preferably 8 g / 10 min or more) and a nucleating agent (for example, a sorbitol-based crystal nucleating agent) have been added. The highly transparent layer may also contain polyethylene, and linear low-density polyethylene (LLDPE) is expected to further enhance transparency. Furthermore, using biopolyethylene makes it environmentally friendly.

[0047] Furthermore, the highly transparent layer is preferably formed from a crystalline resin (e.g., polypropylene) having a higher MFR than the adjacent lower layer (e.g., substrate layer) and a shorter relaxation time than the adjacent lower layer (e.g., transparent layer). Specifically, the highly transparent layer preferably has an MFR at least 1.5 times that of the adjacent lower layer (e.g., substrate layer). If the MFR is less than 1.5 times, the transparency improvement effect may be small. Furthermore, the relaxation time of the highly transparent layer is preferably 80% or less of that of the adjacent lower layer (e.g., transparent layer). If the relaxation time is greater than 80%, the transparency improvement effect may be small. The relaxation time is calculated as follows: The complex elastic modulus G*(iω) measured for the resin pellet is defined as σ* / γ*, where σ* is the stress and γ* is the strain, as shown in the following formula (4), and the relaxation time τ is calculated by the following formula (5). G*(iω)=σ* / γ*=G'(ω)+IG''(ω)...(4) τ(ω)=G'(ω) / (ωG''(ω))···(5) (In the formula, G' represents the storage modulus, and G'' represents the loss modulus.)

[0048] The thickness of the highly transparent layer is usually 1 μm or more, preferably 3 μm or more, and usually 300 μm or less, preferably 200 μm or less. In the laminate according to one embodiment of the present invention, multiple highly transparent layers may be provided, for example, as in the "highly transparent layer / substrate layer / highly transparent layer" structure described below. When multiple highly transparent layers are included, the compositions of the multiple highly transparent layers may be the same or different. Furthermore, the thicknesses of the multiple highly transparent layers may be the same or different.

[0049] The barrier layer is a layer that has oxygen barrier properties, and when used as a package, can suppress oxidative deterioration of the contents. Examples of materials used for the barrier layer include ethylene vinyl alcohol copolymer resin (EVOH), polyvinylidene chloride resin (PVDC), polyacrylonitrile resin (PAN), etc., and one of these may be used alone or two or more may be used in combination. The barrier layer can also be formed by a coating method, and materials that can be used in this case include coating materials selected from the group consisting of inorganic materials such as silica, alumina, aluminum, and silicon nitride, organic materials such as polyvinyl alcohol (PVA), and organic-inorganic hybrid materials such as silica / PVA.

[0050] The thickness of the barrier layer is usually 1 μm or more, preferably 5 μm or more, and usually 50 μm or less, preferably 30 μm or less. The laminate according to one embodiment of the present invention may include a plurality of barrier layers. When the laminate includes a plurality of barrier layers, the barrier layers may have the same composition or different compositions. Furthermore, the barrier layers may have the same thickness or different thicknesses.

[0051] The anti-fogging layer is a layer containing an anti-fogging agent, and examples of the anti-fogging agent include sucrose-based fatty acid esters, glycerin fatty acid esters, fatty acid tertiary amides, higher alcohol fatty acid esters, and propylene glycol fatty acid esters. One of these may be used alone, or two or more may be used in combination.

[0052] The anti-fogging layer is preferably formed from a resin composition containing an anti-fogging agent and a binder component, which is not particularly limited but may be an acrylic adhesive or the like.

[0053] The laminate according to one embodiment of the present invention may include a plurality of anti-fogging layers. When the laminate includes a plurality of anti-fogging layers, the anti-fogging layers may have the same or different compositions. Furthermore, the anti-fogging layers may have the same or different thicknesses.

[0054] The adhesive layer is a layer used as needed to increase the adhesion between the layers of the laminate. For example, a urethane-based elastomer, a styrene-based elastomer, maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, or ethylene vinyl acetate (EVA) can be used, with maleic anhydride-modified polypropylene being preferred.

[0055] The thickness of the adhesive layer is usually 1 μm or more, preferably 3 μm or more, and usually 20 μm or less, preferably 10 μm or less. In the laminate according to one embodiment of the present invention, multiple adhesive layers may be provided, for example, as in the "substrate layer / adhesive layer / barrier layer / adhesive layer / substrate layer" configuration described below. When multiple adhesive layers are included, the compositions of the multiple adhesive layers may be the same or different. Furthermore, the thicknesses of the multiple adhesive layers may be the same or different.

[0056] Examples of the stack structure of the stack according to one embodiment of the present invention include the following structures. (1) Base material layer / base material layer (2) Base material layer / base material layer / base material layer (3) Base material layer / highly transparent layer (4) Highly transparent layer / base material layer / highly transparent layer (5) Base layer / barrier layer (6) Base layer / adhesive layer / barrier layer (7) Base layer / barrier layer / anti-fogging layer (8) Base layer / barrier layer / base layer (9) Base layer / adhesive layer / barrier layer / adhesive layer / base layer (" / " indicates the layer interface.)

[0057] The thickness of the laminate according to one embodiment of the present invention is preferably 100 μm or more, more preferably 150 μm or more, and even more preferably 200 μm or more, and is preferably 2000 μm or less, more preferably 1500 μm or less, even more preferably 1200 μm or less, and particularly preferably 1000 μm or less.

[0058] The method for producing the laminate according to one embodiment of the present invention is not particularly limited, and the above-mentioned resin sheet and other layers may be formed by co-extrusion, or, for example, a barrier layer or the like may be formed on the resin sheet (substrate layer) by a coating method.

[0059] 5.Packaging The resin sheet or laminate according to one aspect of the present invention can be used as a package. That is, the conditions of each component constituting the resin sheet or laminate in the package and the thickness of each layer are the same as those described above. The shape of the package is not particularly limited, and may be a sheet or a three-dimensional hot water container. The container shape may be circular, rectangular, oval, or various other shapes.

[0060] A package according to one embodiment of the present invention can also be described as follows: A package having at least one layer containing polypropylene having smectic crystals and a petroleum resin, wherein the polypropylene has an isotactic pentad fraction of 80 mol% or more and 99 mol% or less, and the content of the petroleum resin in the layer is 1 mass% or more and 20 mass% or less.

[0061] Although the method for producing the packaging body according to an embodiment of the present invention is not particularly limited, it is preferable to heat-mold the resin sheet or laminate according to an embodiment of the present invention at a temperature equal to or lower than the melting point of polypropylene, thereby maintaining a fine crystalline structure and providing a packaging body with high transparency and rigidity.

[0062] The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has a tensile modulus (MD direction) of 3000 MPa or more and 4300 MPa or less. The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has a tensile modulus (TD direction) of 3000 MPa or more and 4300 MPa or less. The tensile modulus is measured by the method described in the examples.

[0063] The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has a yield strength (MD direction) of 45 MPa or more and 55 MPa or less. The sheet portion corresponding to the resin sheet (substrate layer) in the packaging body according to one embodiment of the present invention preferably has a yield strength (TD direction) of 45 MPa or more and 55 MPa or less. The yield strength is measured by the method described in the Examples.

[0064] The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has a breaking strength (MD direction) of 38 MPa or more and 50 MPa or less. The sheet portion corresponding to the resin sheet (base layer) in the package according to one embodiment of the present invention preferably has a breaking strength (TD direction) of 38 MPa or more and 50 MPa or less. The breaking strength is measured by the method described in the examples.

[0065] The sheet portion corresponding to the resin sheet (base layer) in the package according to one embodiment of the present invention preferably has a breaking elongation (MD direction) of 3% or more and 400% or less. The sheet portion corresponding to the resin sheet (base layer) in the package according to one embodiment of the present invention preferably has a breaking elongation (TD direction) of 3% or more and 400% or less. The breaking elongation is measured by the method described in the examples.

[0066] The sheet portion corresponding to the resin sheet (substrate layer) in the packaging body according to one embodiment of the present invention preferably has a total haze of 20% or less, more preferably 15% or less, 10% or less, and even more preferably 5% or less. The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has an internal haze of 15% or less, more preferably 10% or less, 5% or less, and even more preferably 3% or less. The haze is measured by the method described in the examples.

[0067] The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has a total light transmittance of 85% or more, and more preferably 90% or more. The total light transmittance is measured by the method described in the examples.

[0068] The sheet portion corresponding to the resin sheet (substrate layer) in the packaging body according to one embodiment of the present invention preferably has a glossiness of 100% or more and 160% or less. The glossiness is measured by the method described in the examples.

[0069] The sheet portion corresponding to the resin sheet (substrate layer) in the package according to one embodiment of the present invention preferably has an impact strength of at least 900. There is no particular upper limit, but it is, for example, 1500 J / m or less. The impact strength is measured by the method described in the examples.

[0070] The sheet portion corresponding to the resin sheet (base layer) in the package according to one embodiment of the present invention preferably has a buckling strength of 20 N or more, more preferably 25 N or more. The buckling strength is measured by the method described in the examples.

[0071] The packaged products are not particularly limited, but examples include food and beverages such as food and beverages, medicines, medical products, cosmetics, industrial materials, and electronic components. [Example]

[0072] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0073] Example 1 (1) Preparation of resin composition The following polypropylene and petroleum resin were mixed in the blending amounts (mass %) shown in Table 1 to prepare resin composition 1. Polypropylene 1: Homopolypropylene ("F-300SP" manufactured by Prime Polymer Co., Ltd., melting point: 160°C, isotactic pentad fraction: [mmmm] = 92 mol%, MFR: 3 g / 10 min; hereinafter, also referred to as "PP-1") Petroleum resin 1: Hydrogenated petroleum resin (Idemitsu Kosan Co., Ltd. "Imarv" (P-140), dicyclopentadiene / aromatic copolymer petroleum resin, softening point: 140°C, number average molecular weight: 900)

[0074] (2) Manufacturing of resin sheets Using the apparatus shown in FIG. 1, a resin sheet 1 made of a resin composition 1 was produced by the following method. (Method for manufacturing a resin sheet (hereinafter also referred to as "Method 1")) Resin composition 1 was extruded from T-die 11 of the extruder, and sheet-like material 1a was sandwiched between a metal endless belt 25 and a fourth cooling roll 22 on a first cooling roll 21. In this state, sheet-like material 1a was pressed against the first cooling roll 21 and the fourth cooling roll 22 at a circular arc portion corresponding to the central angle θ1 of the first cooling roll 21, and was rapidly cooled. Next, the sheet-like material 1a was sandwiched between the metallic endless belt 25 and the fourth cooling roll 22 in an arc portion corresponding to approximately the lower half of the circumference of the fourth cooling roll 22 and pressed together, and the sheet-like material 1a was further quenched by spraying cooling water onto the back side of the metallic endless belt 25 using a cooling water spray nozzle 26. The sprayed cooling water was collected in a water tank 27 and discharged through a drainage groove 27a. After being face-to-face pressed and cooled by the fourth cooling roll 22, the sheet-like material 1a in close contact with the metal endless belt 25 was moved onto the second cooling roll 23 as the metal endless belt 25 rotated. Here, the sheet-like material 1a, guided by the peeling roll 29 and pressed toward the second cooling roll 23, was face-to-face pressed by the metal endless belt 25 at a circular arc portion corresponding to approximately the upper half of the second cooling roll 23, as described above, and was cooled again. Note that water adhering to the back surface of the metal endless belt 25 was removed by a water absorbing roll 28 provided midway between the fourth cooling roll 22 and the second cooling roll 23. The sheet material 1 a cooled on the second cooling roll 23 was then peeled off from the metallic endless belt 25 by a peeling roll 29 . The surface of the first cooling roll 21 is covered with an elastic material 21a made of nitrile-butadiene rubber (NBR). The surface of the second cooling roll 23 is also covered with an elastic material (not shown) made of nitrile-butadiene rubber (NBR). Furthermore, the temperature of the metallic endless belt 25 can be adjusted by a cooling means (not shown) such as a water-cooling type built into the third cooling roll 24 or the like.

[0075] The manufacturing conditions for the resin sheet 1 are as follows. T-die 11 width (die edge size): 900mm Resin sheet 1 thickness: 0.30 mm Resin sheet 1 take-up speed: 3.6 m / min Surface temperature of the fourth cooling roll 22 and the metal endless belt 25: 20°C ·Cooling rate: 10,800℃ / min (180℃ / sec)

[0076] (3) Evaluation of resin sheet (before thermoforming treatment) The following evaluations were carried out on the obtained resin sheet 1. The results are shown in Table 1.

[0077] (a1) Isotactic pentad fraction About PP-1 13The isotactic pentad fraction was measured by evaluating the C-NMR spectrum. Specifically, the peak assignments proposed by A. Zambelli et al. in "Macromolecules, 8, 687 (1975)" were used with the following equipment, conditions, and calculation formula. (equipment / conditions) Device: 13 C-NMR device (JEOL Ltd. "JNM-EX400" model) Method: Proton complete decoupling method (concentration: 220 mg / ml) Solvent: 90:10 (volume ratio) mixture of 1,2,4-trichlorobenzene and heavy benzene Temperature: 130℃ Pulse width: 45° Pulse repetition time: 4 seconds Accumulation: 10,000 times (calculation formula) Isotactic pentad fraction [mmmm] = m / S × 100 Racemic pentad fraction [rrrr] = γ / S × 100 Racemic-mesoracemic-mesopentad fraction [rmrm] = Pββ + Pαβ + Pαγ S: signal intensity of the side chain methyl carbon atoms of all propylene units Pββ: 19.8 to 22.5 ppm Pαβ: 18.0 to 17.5 ppm Pαγ: 17.5 to 17.1 ppm γ: Racemic pentad chain: 20.7-20.3 ppm m: Mesopentad chain: 21.7-22.5 ppm

[0078] (a2) Crystallization rate The crystallization rate of PP-1 was measured using a differential scanning calorimeter (DSC) (PerkinElmer "Diamond DSC"). Specifically, polypropylene was heated from 50°C to 230°C at 10°C / min, held at 230°C for 5 minutes, cooled from 230°C to 130°C at 80°C / min, and then held at 130°C for crystallization. Measurement of the change in heat quantity was started when the temperature reached 130°C, and a DSC curve was obtained. The crystallization rate was determined from the obtained DSC curve using the following steps (i) to (iv). (i) The baseline was determined as a linear approximation of the change in heat quantity from a point 10 times the time from the start of measurement to a point 20 times the time from the start of measurement to the maximum peak top. (ii) The intersection points of the tangent line having a slope at the inflection point of the peak and the baseline were determined, and the crystallization start and end times were calculated. (iii) The time from the obtained crystallization start time to the peak top was measured as the crystallization time. (iv) The crystallization rate was calculated from the reciprocal of the obtained crystallization time.

[0079] (a3) Melting point The melting point of PP-1 was measured as follows: Using a differential scanning calorimeter (DSC) (Diamond DSC, manufactured by PerkinElmer Japan Co., Ltd.), polypropylene was heated from 50°C to 200°C at a rate of 10°C / min, held at 220°C for 5 minutes, and cooled from 220°C to 50°C at a rate of 10°C / min. The temperature at which the maximum endothermic peak was obtained was taken as the melting point of the polypropylene.

[0080] (a4) Crystal structure The crystal structure of PP-1 was identified by measuring the wide-angle X-ray scattering pattern under the following measurement conditions using an X-ray generator (Model Ultra X 18HB, manufactured by Rigaku Corporation). As a result, even after peak separation, a Smectite crystal-type peak was observed in Resin Sheet 1, confirming the presence of Smectite crystals in Resin Sheet 1. (Measurement conditions) Light source wavelength: 300mA CuKα line (wavelength = 1.54Å) monochromatic light Line source output voltage / current: 50kV / 250mA Irradiation time: 60 minutes Camera length: 1.085m -Sample thickness: Stack the sheets so that they are 1.5 to 2.0 mm. Stack the sheets so that the film formation (MD) direction is aligned. In order to shorten the measurement time, the sheets are stacked so that the spacing is 1.5 to 2.0 mm, but if the measurement time is extended, it is possible to measure with just one sheet without stacking the sheets.

[0081] (b) Tensile properties The tensile properties, tensile modulus, yield strength, breaking strength, and breaking elongation, were measured in accordance with JIS K 7161. Each measurement was carried out in the extrusion direction (MD) of molding and in the direction perpendicular to the MD (TD).

[0082] (c1) Haze The total haze and internal haze were measured using a haze meter ("NDH2000" manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136.

[0083] (c2) Total light transmittance The total light transmittance was measured in accordance with JIS K7136 using a haze meter ("NDH2000" manufactured by Nippon Denshoku Industries Co., Ltd.).

[0084] (c3) Glossiness In accordance with the JIS Z 8741 method for measuring 60-degree specular gloss, an automatic colorimeter (AUD-CH-2 type-45,60, manufactured by Suga Test Instruments Co., Ltd.) was used to measure the reflected luminous flux ψs when irradiating light at an incident angle of 60 degrees and receiving reflected light at the same 60 degrees, and the gloss was calculated using the following formula (1) as the ratio to the reflected luminous flux ψ0s from a glass surface with a refractive index of 1.567. Glossiness (Gs) = (ψs / ψ0s) * 100 (1)

[0085] (d) Impact strength (film impact) Measurements were made at 23°C using a film impact tester (Yasuda Seiki Seisakusho Co., Ltd., product number 181, conforming to ASTM D3420) under conditions of a test load of 6J and a 1-inch head. After the above test, the degree of damage to the resin sheet 1 was visually checked and evaluated according to the following criteria. ○: Radial cracks occurred around the impact area, and slight damage (holes) to the sheet was observed. ×: Clear damage (holes) was observed in the sheet, mainly around the impacted area.

[0086] (4) Evaluation of resin sheet (after thermoforming treatment) The obtained resin sheet 1 was subjected to solid-phase molding at a temperature below the melting point to form a container with a flange outer diameter of 125 mm x 125 mm and a depth of 25 mm into a thermoformed top surface. The resin sheet after this process was evaluated in the same manner as in (b) to (d) of "(3) Evaluation of resin sheet (before heat treatment)", as well as the buckling strength evaluation described below. The buckling strength evaluation was performed on Examples 2 to 4. The results are shown in Table 2. (e) Buckling strength Buckling strength was measured under the following conditions using a universal material testing machine (Instron Model 5566) in accordance with JIS K7181. A photograph of the molded product used for the measurement is shown in Figure 2. Note that the corners of the molded product are slightly rounded, but this has almost no effect on the buckling strength. Measurement sample: Molded product (flange outer dimensions 125mm x 125mm, flange inner dimensions 104mm x 104mm, top outer dimensions 74mm x 74mm, depth 12mm) Measurement conditions: Test environment 23°C, 50% RH, test speed 10 mm / min Calculation method: The maximum load at a compressive displacement of 2 mm or less was calculated and used as the buckling strength. The temperature of the test environment may be 23°C ± 2°C, and the humidity may be 50% RH ± 10% RH; as long as it is within these ranges, there will be almost no effect on the measurement results.

[0087] Examples 2 to 4 Resin compositions and resin sheets were produced and evaluated in the same manner as in Example 1, except that the thickness of the resin sheet was changed as shown in Table 1. The results are shown in Tables 1 and 2. 3 shows photographs of the resin sheets after film impact evaluation (impact resistance test) in Example 2 and Comparative Example 1 described below. In the figure, Example 2 is on the right and Comparative Example 1 is on the left.

[0088] Comparative Example 1 A resin sheet was produced and evaluated in the same manner as in Example 1, except that the resin sheet was produced in the following manner. The results are shown in Tables 1 and 2. (Method for manufacturing a resin sheet (hereinafter also referred to as "Method 2")) A resin sheet was produced by the following method using a distributor-type co-extrusion laminate sheet production apparatus shown in Figure 4. Specifically, in this production apparatus, molten resin co-extruded from a T-die 72 of an extruder was brought into close contact with a cooling roll 76 by an air knife 74, and cooled by cooling rolls 76 and 78 to produce a laminate sheet 71. The production conditions are as follows: Extruder diameter: 65mm Width of T-die 72: 900mm Take-up speed of laminated sheet 71: 3.4 m / min Surface temperature of cooling rolls 76 and 78: 95℃ ·Cooling rate: 2,300℃ / min (38℃ / sec)

[0089] Comparative Example 2 A resin sheet was produced and evaluated in the same manner as in Comparative Example 1, except that petroleum resin 1 was not added. The results are shown in Tables 1 and 2.

[0090] [Table 1]

[0091] [Table 2]

[0092] From Table 1, it can be seen that the resin sheets of Examples 1 to 4 have higher haze, total light transmittance, and gloss than the resin sheets of Comparative Examples 1 and 2, and are excellent in optical properties such as transparency. Furthermore, as can be seen from a comparison between Comparative Example 1 and Comparative Example 2, while the addition of petroleum resin generally significantly reduces impact strength, the resin sheet of the present invention, despite containing petroleum resin, exhibits excellent impact resistance in some cases that is significantly higher than that of Comparative Example 2, which does not contain petroleum resin. Note that although the tensile properties of the resin sheets of Examples 1 to 4 are numerically inferior to those of Comparative Examples 1 and 2 in some items, they can be said to have sufficient rigidity for use. It can be seen from Table 2 that the molded articles (packaging articles) obtained by thermoforming the resin sheets of Examples 1 to 4 have high rigidity and excellent transparency. [Industrial Applicability]

[0093] A package according to one embodiment of the present invention can be used to package foods, beverages, and other foods, medicines, medical supplies, cosmetics, industrial materials, electronic components, and the like. [Explanation of symbols]

[0094] 1a Sheet-like object 10 Manufacturing equipment 11 T-die 21 First cooling roll 21a Elastic material 22 Fourth cooling roll 23 Second cooling roll 24 Third cooling roll 25 Metal endless belt 26 Cooling water spray nozzle 27 Aquarium 27a Drainage ditch 28 Water-absorbing roll 29 Peeling roll θ1 Center angle 71 Laminate 72 T-die 74 Air Knife 76,78 Cooling roll

Claims

1. a resin sheet containing a resin composition comprising 75 to 99% by mass of polypropylene having Smectica crystals and 1% by mass or more of a petroleum resin, wherein the petroleum resin is one or more selected from the group consisting of a petroleum resin containing a monomer unit derived from dicyclopentadiene, a petroleum resin obtained by acid-modifying a petroleum resin containing a monomer unit derived from dicyclopentadiene, and a petroleum resin obtained by hydrogenating a petroleum resin containing a monomer unit derived from dicyclopentadiene; a second layer containing polypropylene having smectic crystals laminated on at least one surface of the resin sheet; A package made using a laminate comprising:

2. 2. The packaging body according to claim 1, wherein the isotactic pentad fraction of the polypropylene in the resin composition is 80 mol % or more and 99 mol % or less.

3. The crystallization rate of the polypropylene in the resin composition at 130°C is 2.5 min －１ 3. The package of claim 1 or 2, wherein:

4. The package according to any one of claims 1 to 3, wherein the content of the petroleum resin in the resin composition is 1% by mass or more and 20% by mass or less.

5. The packaging body according to any one of claims 1 to 4, wherein the content of the nucleating agent in the resin composition is 1.0% by mass or less.

6. The package according to any one of claims 1 to 5, wherein the resin sheet has an internal haze of 15% or less.

7. 7. The package according to claim 1, wherein the second layer contains at least one selected from the group consisting of a petroleum resin containing a monomer unit derived from dicyclopentadiene, a petroleum resin obtained by acid-modifying a petroleum resin containing a monomer unit derived from dicyclopentadiene, and a petroleum resin obtained by hydrogenating a petroleum resin containing a monomer unit derived from dicyclopentadiene.

8. The packaging body according to any one of claims 1 to 7, wherein a layer containing polypropylene and a nucleating agent is laminated on the surface of the resin sheet opposite to the surface on which the second layer is laminated.

9. The package according to any one of claims 1 to 8, wherein the thickness of the laminate is 100 µm or more and 2000 µm or less.

10. The package according to any one of claims 1 to 9, having a buckling strength of 20 N or more as measured in accordance with JIS K7181 under the following conditions: Measurement sample shape: flange outer dimensions 125mm x 125mm, flange inner dimensions 104mm x 104mm, top outer dimensions: 74mm x 74mm, depth 12mm Measurement conditions: Test environment 23°C ± 2°C, 50% RH ± 10% RH, test speed 10 mm / min Calculation method: The maximum load at a compressive displacement of 2 mm or less is calculated and used as the buckling strength.

11. A method for manufacturing a packaging body, which produces the packaging body according to any one of claims 1 to 10, comprising heat-molding the laminate at a temperature equal to or lower than the melting point of the polypropylene in the resin composition.

Images