Laminate, container, and method for manufacturing laminate

Abstract

To provide a laminate having a water vapor barrier layer, in which the water vapor barrier properties are improved while impact resistance and thermoformability are maintained.SOLUTION: A laminate contains a first layer composed of a first resin composition containing a first polyolefin and a petroleum resin, and a second layer composed of a second resin composition containing a second polyolefin, an inorganic filler and a petroleum resin.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a laminate, a container, and a method for producing the laminate. [Background technology]

[0002] Conventionally, laminates have been used as packaging materials for medicines, medical products, cosmetics, food, beverages, industrial materials, electronic components, etc. It is also known to construct containers using laminates having a water vapor barrier layer and an oxygen barrier layer in order to improve the protection of the contents, for example, the barrier properties against water vapor and oxygen. For example, Patent Document 1 describes a technology in which a sheet having a water vapor barrier layer and an oxygen barrier layer is provided with a predetermined amount of inorganic filler added to the water vapor barrier layer, thereby exhibiting high barrier properties even after retort and sterilization treatment.

[0003] In this way, the water vapor barrier property can be improved by adding an inorganic filler to the water vapor barrier layer, or by adding a petroleum resin to the water vapor barrier layer in the same way. By laminating a water vapor barrier layer having high water vapor barrier property together with an oxygen barrier layer, it is possible to prevent the oxygen barrier property from decreasing when the contents are heated, even when the oxygen barrier layer is formed from, for example, an ethylene vinyl alcohol resin which has high oxygen barrier property but is highly dependent on humidity. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-24556 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, a container in which a molded body made of a laminate having a water vapor barrier layer is filled with contents and sealed, and then heat-treated, may be easily damaged by impacts such as dropping during storage or transportation at a low temperature after the heat treatment.

[0006] Therefore, an object of the present invention is to provide a laminate, a container, and a method for manufacturing a laminate that can maintain impact resistance and thermoformability while enhancing water vapor barrier properties in a laminate having a water vapor barrier layer.

Means for Solving the Problems

[0007] [1] A laminate including a first layer formed of a first resin composition containing a first polyolefin and a petroleum resin, and a second layer formed of a second resin composition containing a second polyolefin, an inorganic filler, and a petroleum resin. [2] The laminate according to [1], including the first layer, the second layer, and a third layer formed of a third resin composition containing a first polyolefin and a petroleum resin in this order. [3] The laminate according to [2], including the first layer, the second layer, an oxygen barrier layer, a fourth layer formed of a fourth resin composition containing a second polyolefin and a petroleum resin, and the third layer in this order. [4] The laminate according to [3], including the first layer, the second layer, an oxygen barrier layer, the fourth layer, the third layer, and a seal layer in this order. [5] The laminate according to any one of [1] to [4], wherein the 50% fracture energy measured by the DuPont impact test performed in a -5°C environment is 0.4 J or more. [6] The laminate according to any one of [1] to [5], wherein the water vapor transmission rate is less than 0.20 g / (m 2 ·24 h). [7] The laminate according to any one of [1] to [6], wherein either or both of the first polyolefin and the second polyolefin contain a highly stereoregular polypropylene. [8] The laminate according to [7], wherein the content rate of the highly stereoregular polypropylene is 10% by mass or more with respect to the whole laminate. [9] In the first resin composition, the laminated body according to [7] or [8], wherein the content of the highly stereoregular polypropylene is 5% by mass or more.

[10] In the second resin composition, the laminated body according to any one of [7] to [9], wherein the content of the highly stereoregular polypropylene is 10% by mass or more.

[11] The laminated body according to any one of [7] to

[10] , wherein either or both of the first polyolefin and the second polyolefin further contain polyethylene.

[12] The laminated body according to any one of [1] to

[11] , wherein the total content of the first polyolefin and the second polyolefin is 70% by mass or more based on the whole laminated body.

[13] The laminated body according to any one of [1] to

[12] , wherein the content of the petroleum resin is 1% by mass or more and 15% by mass or less based on the whole laminated body.

[14] The laminated body according to any one of [1] to

[13] , wherein the content of the petroleum resin in the first resin composition is 1% by mass or more.

[15] The laminated body according to any one of [1] to

[14] , wherein the content of the petroleum resin in the second resin composition is 2% by mass or more.

[16] The laminated body according to any one of [1] to

[15] , wherein the content of the inorganic filler is 1% by mass or more based on the whole laminated body.

[17] The laminated body according to any one of [1] to

[16] , wherein the content of the inorganic filler in the second resin composition is 2% by mass or more.

[18] A container including a first layer formed of a first resin composition containing a first polyolefin and a petroleum resin, and a second layer formed of a second resin composition containing a second polyolefin, an inorganic filler, and a petroleum resin.

[19] The container according to

[18] , including the first layer, the second layer, and a third layer formed of a third resin composition containing a first polyolefin and a petroleum resin in this order.

[20] The container according to

[19] , including the first layer, the second layer, an oxygen barrier layer, a fourth layer formed of a fourth resin composition containing a second polyolefin and a petroleum resin, and the third layer in this order.

[21] The container according to

[20] , comprising a first layer, a second layer, an oxygen barrier layer, a fourth layer, a third layer, and a seal layer in this order.

[22] The container according to any one of

[18] to

[21] , having a buckling strength of 30 N or more.

[23] The container according to any one of

[18] to

[22] , having a content evaporation rate of 0.50% or less when stored in an environment of 40 °C and a relative humidity of 25% for two weeks.

[24] A method for manufacturing a laminate, comprising a step of co-extrusion molding a laminate including a first layer formed of a first resin composition containing a first polyolefin and a petroleum resin, and a second layer formed of a second resin composition containing a second polyolefin, an inorganic filler, and a petroleum resin. [Effect of the Invention]

[0008] According to the above configuration, by dispersing and adding a hydrogenated petroleum resin to both the first base material layer and the second base material layer, while maintaining the addition amount of the hydrogenated petroleum resin as a whole of the laminate to enhance the water vapor barrier property, it is possible to suppress a decrease in impact resistance and thermoformability of the polyolefin due to a locally increased addition amount of the hydrogenated petroleum resin. [Brief Description of the Drawings]

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted. Note that the ratio of raw materials is described by mass ratio (or mass %) unless otherwise specified.

[0011] FIG. 1 is a schematic cross-sectional view showing the laminated structure of a laminate according to an embodiment of the present invention. The laminate 10 has first base material layers 11 and 13, second base material layers 12 and 14, an oxygen barrier layer 15, and a seal layer 16. Specifically, the laminate 10 includes a first base material layer 11, a second base material layer 12, an oxygen barrier layer 15, a second base material layer 14, a first base material layer 13, and a seal layer 16 in this order. The laminate 10 is formed with a thickness suitable for forming a container, specifically, for example, a thickness of 0.3 mm or more and 1.2 mm or less, but is not limited to this example. From the viewpoint of reducing the resin usage amount, 1.1 mm or less is preferable, 1.0 mm or less is more preferable, and 0.9 mm or less is even more preferable. Hereinafter, the configuration of each layer will be described.

[0012] The first base material layers 11 and 13 are formed of a first resin composition containing a first polyolefin and a petroleum resin. Also, the second base material layers 12 and 14 are formed of a second resin composition containing a second polyolefin, an inorganic filler, and a petroleum resin. Here, although both the first base material layers 11 and 13 contain a first polyolefin and a petroleum resin, the compositions may be different between the first base material layer 11 and the first base material layer 13. That is, the third resin composition forming the first base material layer 13 may be the same as or different from the first resin composition forming the first base material layer 11. Similarly, although both the second base material layers 12 and 14 contain a second polyolefin, an inorganic filler, and a petroleum resin, the compositions may be different between the second base material layer 12 and the second base material layer 14. That is, the fourth resin composition forming the second base material layer 14 may be the same as or different from the second resin composition forming the second base material layer 12. Further, the total thickness of the first base material layer and the second base material layer in the laminate is 10% to 100% of the thickness of the laminate 10, more preferably 30% to 99%, still more preferably 50% to 98%, and particularly preferably 70% to 95%.

[0013] In this embodiment, the total content of the first polyolefin and the second polyolefin with respect to the whole of the laminate 10 is, for example, 50% or more, preferably 60% or more, more preferably 70% or more. The upper limit of the total content of the first polyolefin and the second polyolefin with respect to the whole of the laminate 10 is usually 99% or less. The content of the first polyolefin in the first resin composition is, for example, 60% or more, preferably 70% or more, more preferably 80% or more, still more preferably 85% or more. The upper limit of the content of the first polyolefin in the first resin composition is usually 99% or less. Further, the content of the second polyolefin in the second resin composition is, for example, 60% or more, preferably 70% or more, more preferably 80, still more preferably 85% or more. The upper limit of the content of the second polyolefin in the second resin composition is usually 99% or less. The content of the polyolefin can be confirmed, for example, by the IR method. Incidentally, for each of the first and second resin compositions, mixing of additives and impurities such as elastomers other than the first and second polyolefins, petroleum resins, and inorganic fillers is allowed.

[0014] Examples of the first and second polyolefins contained in the first and second resin compositions for forming each of the above base material layers include polypropylene, polyethylene, or cyclic polyolefin, and preferably homopolypropylene is used. The first and second polyolefins may be the same type of polyolefin or different types of polyolefins from each other. Also, the first and second polyolefins may be a mixture of two or more types of polyolefins. For example, either or both of the first polyolefin and the second polyolefin may contain highly stereoregular polypropylene which is polypropylene having an isotactic pentad fraction of 80 mol% or more as described later. The isotactic pentad fraction of the highly stereoregular polypropylene is preferably 87 mol% or more, more preferably 92 mol% or more, still more preferably 95 mol% or more, and particularly preferably 97 mol% or more. The upper limit value of the isotactic pentad fraction is not particularly limited, but is, for example, 100 mol%. By increasing the isotactic pentad fraction of the highly stereoregular polypropylene, the barrier property can be improved. The content of the highly stereoregular polypropylene with respect to the whole of the laminate 10 is, for example, 5% or more, preferably 15% or more, more preferably 30% or more. The upper limit value of the highly stereoregular polypropylene with respect to the whole of the laminate 10 is usually 99% or less. The content of the highly stereoregular polypropylene in the first resin composition is, for example, 50% or more, preferably 60% or more, more preferably 70% or more, still more preferably 80% or more. The upper limit value of the highly stereoregular polypropylene in the first resin composition is usually 99% or less. Also, the content of the highly stereoregular polypropylene in the second resin composition is, for example, 45% or more, preferably 55% or more, more preferably 65% or more, still more preferably 75% or more. The upper limit value of the highly stereoregular polypropylene in the second resin composition is usually 99% or less. When the content of high-density polyethylene (HDPE) in the second resin composition is made higher than that in the first resin composition as described later, the content of the highly stereoregular polypropylene is lower in the second resin composition than in the first resin composition.

[0015] Also, either or both of the first polyolefin and the second polyolefin may be a mixture of highly stereoregular polypropylene and high-density polyethylene (HDPE). The density of HDPE is, for example, 930 kg / m 3 or more, preferably 935 kg / m 3 or more, more preferably 942 kg / m 3 or more. The content of HDPE in the first resin composition is, for example, 3% or more, preferably 5% or more, more preferably 7% or more, more preferably 9% or more. The upper limit of the content of HDPE in the first resin composition is usually 30% or less. Also, the content of HDPE in the second resin composition is, for example, 5% or more, preferably 10% or more, more preferably 15% or more, more preferably 18% or more. The upper limit of the content of HDPE in the second resin composition is usually 40% or less. Since the second resin composition contains an inorganic filler, it is preferable to make the content of HDPE higher than that of the first resin composition in order to ensure moldability and fluidity.

[0016] The petroleum resins contained in the first and second resin compositions may be of a synthetic resin type or a natural resin type. In the case of a synthetic resin type, examples include an aliphatic type, an aromatic hydrocarbon resin type, an alicyclic saturated hydrocarbon resin type, a copolymer type, etc. Preferably, either or both of the first and second resin compositions contain a hydrogenated petroleum resin. As the hydrogenated petroleum resin, for example, Imarflex (registered trademark) or Alcon (registered trademark) etc. are used. The content rate of the petroleum resin with respect to the whole of the laminate 10 is, for example, 1% or more, preferably 3% or more, more preferably 5% or more. The upper limit value of the content rate of the petroleum resin with respect to the whole of the laminate 10 is, for example, 20% or less, preferably 15% or less, more preferably 12% or less, still more preferably 10% or less. The content rate of the petroleum resin in the first resin composition is, for example, 1% or more, preferably 3% or more, more preferably 5% or more, preferably 7% or more. The upper limit value of the content rate of the petroleum resin in the first resin composition is, for example, 20% or less, preferably 15% or less, more preferably 12% or less, still more preferably 10% or less. Also, the content rate of the petroleum resin in the second resin composition is, for example, 1% or more, preferably 3% or more, more preferably 5% or more, still more preferably 7% or more, particularly preferably 9% or more. The upper limit value of the content rate of the petroleum resin in the second resin composition is, for example, 20% or less, preferably 15% or less, more preferably 12% or less, still more preferably 10% or less. The higher the content rate of the petroleum resin, the more the barrier property is improved, but if the content rate is too high, the fluidity becomes excessive and it becomes easy to generate poor appearance. On the other hand, if the content rate of the petroleum resin is too low, the barrier property and rigidity become insufficient. Therefore, it is preferable to set the content rate of the petroleum resin within an appropriate range as described above.

[0017] Examples of the inorganic filler contained in the second resin composition include talc, calcium carbonate, magnesium hydroxide, etc. With respect to the entire laminate 10, the content rate of the inorganic filler is, for example, 1% or more, preferably 5% or more, more preferably 8% or more. The upper limit value of the content rate of the inorganic filler with respect to the entire laminate 10 is, for example, 50% or less, preferably 30% or less, more preferably 20% or less. The content rate of the inorganic filler in the second resin composition is, for example, 2% or more, preferably 7% or more, more preferably 17% or more, still more preferably 25% or more. The upper limit value of the content rate of the inorganic filler in the second resin composition is, for example, 60% or less, preferably 50% or less, more preferably 40% or less. If the content rate of the inorganic filler is too low, the barrier property and rigidity will be insufficient. On the other hand, if the content rate of the inorganic filler is too high, the impact resistance will decrease and appearance defects are likely to occur. Therefore, it is preferable to set the content rate of the inorganic filler within an appropriate range as described above.

[0018] Here, the highly stereoregular polypropylene that may be included in either or both of the first polyolefin and the second polyolefin will be further described. When the isotactic pentad fraction of the polypropylene-based resin is less than 80 mol%, excessive biting is likely to occur during sealing, so it is preferably set to 80 mol% or more. The more preferable range of the isotactic pentad fraction is as described above. Here, the measurement of the isotactic pentad fraction used as an index of stereoregularity can be exemplified by a method based on the 13C-NMR method disclosed by, for example, A. Zambelli et al. ("Carbon-13 Observations of the Stereochemical Configuration of Polypropylene," Macromolecules, Vol. 6, No. 6, pp. 925-926, 1973). Specifically, first, 220 mg of an i-PP sample was taken into a 10 mm diameter NMR sample tube, 2.5 ml of a 1,2,4-trichlorobenzene / deuterated benzene mixed solution (90 / 10 vol%) was added, and the mixture was uniformly dissolved at 140 °C. Then, a 13C-NMR spectrum was measured using JNM-EX400 (trade name: manufactured by JEOL Ltd.). The 13C-NMR spectrum measurement conditions are shown below.

[0019] · Pulse width: 7.5 μs / 45 degrees · Observation frequency range: 25,000 Hz · Pulse repetition time: 4 seconds · Measurement temperature: 130 °C · Number of integrations: 10,000 times

[0020] The isotactic pentad fraction is defined as the relative ratio of the peak area corresponding to "mmmm" to the areas of all nine peaks observed as a 13C-NMR spectrum corresponding to each of the nine bonding patterns of five propylene molecules ("mmmm", "mmmr", "rmmr", "mmrr", "rmrr+mrmm", "rmrm", "rrrr", "mrrr", "mrrm"). Specifically, it is calculated by the following relational expression (1). Here, when there is an overlap between two peaks, perpendicular lines are drawn from the valleys of the two peaks to the baseline to divide both peaks (vertical division method).

[0021] {Relational expression (1)} Isotactic pentad fraction (mol%) ={A(mmmm) / A(total)} × 100 …(1) Here, A(mmmm) is the area of the mmmm peak, and A(total) means the sum of the areas of the nine peaks.

[0022] In addition, when there is an overlap between two peaks, in addition to the above vertical division method, a method of performing waveform separation with each peak as an aggregate of Lorentzian peaks is also known, and the value obtained using analysis software (ALICE 2 of JEOL Ltd.) may also be used.

[0023] The oxygen barrier layer 15 is formed of an oxygen barrier layer containing an ethylene vinyl alcohol resin such as ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride, or polyacrylonitrile, and is preferably ethylene-vinyl alcohol copolymer (EVOH). Adhesive layers 151 and 152 such as maleic anhydride-modified polypropylene are formed between the oxygen barrier layer 15 and the second base material layers 12 and 14 laminated on both sides of the oxygen barrier layer 15.

[0024] The seal layer 16 is formed of a resin composition suitable for joining by heat sealing or the like with a lid when a container is formed of the laminate 10. Such a resin composition is, for example, a polyolefin, specifically, a polypropylene-based resin such as homopolypropylene (HPP), random polypropylene (RPP), or block polypropylene (BPP), a polyethylene-based resin such as high-density polyethylene (HDPE) or low-density polyethylene (LDPE), or a linear ethylene-α-olefin copolymer, etc. is used.

[0025] In the laminate 10 as described above, high oxygen barrier properties are achieved by the oxygen barrier layer 15 containing EVOH. Further, high water vapor barrier properties are achieved by the first base material layers 11, 13 mainly composed of polyolefin and containing a hydrogenated petroleum resin, and the second base material layers 12, 14 mainly composed of polyolefin and containing an inorganic filler and a hydrogenated petroleum resin. By adding an inorganic filler or a hydrogenated petroleum resin, the water vapor barrier properties of the polyolefin are further enhanced. By providing water vapor barrier properties to the layer on the content side rather than the oxygen barrier layer 15 when a container is formed of the laminate 10, it is possible to prevent the oxygen barrier properties of the oxygen barrier layer 15 from decreasing due to water vapor during heating of the content.

[0026] In the present embodiment, by dispersing and adding the hydrogenated petroleum resin to both the first base material layer and the second base material layer, while maintaining the addition amount of the hydrogenated petroleum resin as a whole of the laminate and enhancing the water vapor barrier properties, it is possible to suppress a decrease in impact resistance and thermoformability of the polyolefin due to an increase in the addition amount of the hydrogenated petroleum resin locally.

[0027] In addition, a decrease in impact resistance and thermoformability of the polyolefin due to the addition of an inorganic filler or a hydrogenated petroleum resin is also suppressed by adding a thermoplastic elastomer. Depending on the required degree of impact resistance and thermoformability, at least one of the first base material layers 11, 13 or the second base material layers 12, 14 may contain a thermoplastic elastomer. As the thermoplastic elastomer, for example, an olefin-based elastomer, or an α-olefin copolymer, etc. is used.

[0028] In the above laminate 10, the layer thickness of each layer and the blending ratio of the raw materials are not necessarily limited. For example, the total content of polyolefin is 70% by mass or more, the content of hydrogenated petroleum resin is about 10% by mass, the content of inorganic filler is about 15% by mass, and the content of the raw materials of the oxygen barrier layer and the adhesive layer is about 5% by mass each with respect to the whole laminate. A configuration in which the water vapor barrier property can be improved by the blending ratio of the raw materials as described above is exemplified.

[0029] FIG. 2 and FIG. 3 are schematic cross-sectional views showing modified examples of the laminate according to the embodiment of the present invention. In the example described with reference to FIG. 1 above, for example, when heat sealing with a lid body is not performed, the seal layer 16 is not required. Therefore, as in the example shown in FIG. 2, a laminate 10A including a first base material layer 11, a second base material layer 12, an oxygen barrier layer 15, a second base material layer 14, and a first base material layer 13 in this order can be used. Further, the configuration for realizing a high water vapor barrier property with the above-described first and second resin compositions is effective not only when combined with the oxygen barrier property. Therefore, as in the example shown in FIG. 3, a laminate 10B including a first base material layer 11, a second base material layer 12, and a first base material layer 13 in this order and not including an oxygen barrier layer can also be used. Further, although not shown, a laminate composed of two layers of the first base material layer 11 and the second base material layer 12 can also be used.

[0030] Regarding the laminate according to the embodiment of the present invention as described above, as shown by the examples described later, the 50% fracture energy measured by the DuPont impact test performed in an environment of -5°C is, for example, 0.4 J or more, preferably 0.5 J or more, and more preferably 0.6 J or more. The upper limit value is preferably higher but is usually 3 J. Further, the water vapor permeability is, for example, less than 0.20 g / (m 2 ·24 h), preferably 0.18 g / (m 2 ·24 h) or less, and more preferably 0.16 g / (m 2 ·24 h) or less. The lower limit value is preferably lower but is usually 0.01 g / (m 2·It is 24 h). Note that since these indicators of cold resistance impact and water vapor barrier properties improve further as the ratio of the base material layer to the whole of the laminate increases, the above numerical range is applicable also to the cases of the laminates 10A and 10B shown in FIGS. 2 and 3, as in the case of the laminate 10 shown in FIG. 1.

[0031] FIG. 4 is a cross-sectional view of a container formed of the laminate shown in FIG. 1. As shown in FIG. 4, the container 100 includes a container body formed of the laminate 10 and a lid body 20 joined to the container body. For simplicity, only the first base material layer 11 and the second base material layer 12 are shown as the layers of the laminate 10, and the other layers are omitted. It is also possible to form the container body with the laminates 10A and 10B shown in FIGS. 2 and 3 instead of the laminate 10, or with a laminate composed of two layers of the first base material layer 11 and the second base material layer 12. In the illustrated example, the container body is formed in a shape including a bottom surface portion 101, a side surface portion 102, and a flange portion 103, and the lid body 20 is joined to the container body at the flange portion 103. The lid body 20 and the flange portion 103 are joined by, for example, heat sealing. By forming the lid body 20 with a laminate having oxygen barrier properties and water vapor barrier properties and joining the container body and the lid body 20 to each other, a storage space for storing the contents is sealed, and high protection of the contents, specifically, barrier properties against water vapor and oxygen are realized.

[0032] When the container 100 as described above is heat-treated for sterilizing the contents or the like, water vapor is generated in the storage space. When the generated water vapor reaches the oxygen barrier layer 15, the oxygen barrier property may decrease. However, in this embodiment, the oxygen barrier layer 15 is protected from the water vapor by the first base material layer 13 and the second base material layer 14 included in the laminate 10. Therefore, even after the heat treatment of the container, the oxygen barrier property of the oxygen barrier layer 15 is maintained, and the quality of the contents can be kept good. For example, when the container 100 is stored or transported in a low-temperature state after the heat treatment and is subjected to an impact such as a drop, the hydrogenated petroleum resin is dispersed and added to the first base material layers 11 and 13 and the second base material layers 12 and 14 in the laminate 10, so that the impact resistance is maintained and the container 100 is not deformed or the first base material layers 11 and 13 and the second base material layers 12 and 14 are not damaged, and a good water vapor barrier property can be continuously obtained.

[0033] Regarding the container according to the embodiment of the present invention as described above, as shown by the examples described later, the buckling strength of the container body is, for example, 30 N or more, preferably 40 N or more, and more preferably 80 N or more. If it is a laminate that can easily obtain the buckling strength of the container body, the amount of resin used can be reduced by thinning the container body while maintaining the strength. Thereby, it is possible to reduce the amount of use of resins derived from fossil fuels, which has been required in recent years for environmental protection, and for example, reduce the carbon dioxide emissions during incineration. The buckling strength of the container body is preferably higher, but the upper limit is usually 400 N or less. Further, when water is enclosed in the storage space formed between the container body and the lid body and stored for 2 weeks in an environment of 40 °C and a relative humidity of 25%, the content evaporation rate is, for example, 0.50% or less, preferably 0.45% or less, and more preferably 0.35% or less. The lower limit value is preferably lower, and is usually 0.1%. In addition, since these indexes of cold impact resistance and water vapor barrier property are further improved as the ratio of the base material layer to the whole laminate increases, the above numerical ranges are the same as those of the laminate 10 shown in FIG. 4, and are also applicable when the laminates 10A and 10B shown in FIGS. 2 and 3 are formed into the container body.

Examples

[0034] Next, examples of the present invention will be described. In the examples, a laminate having the layer structure described above with reference to FIG. 1 was produced using a distributer-type coextrusion multilayer sheet manufacturing apparatus. In the base material layers of the laminates of the examples and comparative examples shown in Table 1, highly stereoregular polypropylene (referred to as PP in Table 1) * and described) had an isotactic pentad fraction of 97 mol% and a melt flow rate of 0.4 g / 10 minutes, high density polyethylene (HDPE) had a melt flow rate of 0.35 g / 10 minutes, hydrogenated petroleum resin was "EX-5N00500A" manufactured by Nippon Pigment Co., Ltd. (a masterbatch (MB) prepared by blending "Imarub P-140" manufactured by Idemitsu Kosan Co., Ltd. and "F133A" manufactured by Prime Polymer Co., Ltd. at a ratio of 1:1), and talc was MB "S-U3" manufactured by Shinwa Plastics Co., Ltd. (a masterbatch (MB) containing about 60% talc). For the oxygen barrier layer, an ethylene-vinyl alcohol copolymer resin (trade name: Eval J) manufactured by Kuraray Co., Ltd. was used, and for the adhesive layers on both sides of the oxygen barrier layer, maleic anhydride-modified polypropylene (trade name: Admer, grade: QB515) manufactured by Mitsui Chemicals, Inc. was used. The thickness of the laminate was 1.0 mm in Example 1, 0.8 mm in Example 2, 0.6 mm in Example 3, and 1.0 mm in Comparative Example 1. The ratio (layer ratio) of the thickness of each layer of the laminate to the total layer thickness was common in each example, with the first base material layer being 30%, the second base material layer being 60%, and the oxygen barrier layer, adhesive layer, and seal layer being 10%. Further, the produced laminate was vacuum-formed to form a container as described above with reference to FIG. 4. Specifically, the laminate was formed into a container body that was a round container with a diameter of 95 mm.

[0035]

Table 1

[0036] The results of evaluating the laminates and containers created in the examples and comparative examples for the following items are shown in Table 2. (1) Cold impact resistance For the laminate, the DuPont impact test specified in JIS K5600-5-3 was carried out at -5°C, and the 50% fracture energy (J) was calculated based on JIS K7211. Also, for the container body, the buckling strength (N) was calculated by the following method. A buckling jig was attached to an Instron universal material testing machine model 5965 (manufactured by Instron Japan Co., Ltd.). The container opening was placed downward under the jig, and the upper side of the jig was lowered at a speed of 10 mm / min to cause buckling of the container. When the primary buckling load was obtained, the lowering of the upper side of the jig was stopped and it was raised to the initial predetermined position. (2) Water vapor barrier property For the laminate, the water vapor permeability (g / (m 2 ·24h)) was measured by the infrared sensor method specified in JIS K7129-2. Also, for the container, 100 g of water was enclosed in the space formed between the container body and the lid, and the content evaporation rate (%) was measured when stored in an environment of 40°C and 25% relative humidity for 2 weeks.

[0037] [Table 2]

[0038] In the results shown in Table 2 above, in each of Examples 1 to 3, since the second base material layer was formed of a resin composition containing a hydrogenated petroleum resin, good evaluation indices were obtained for the cold resistance impact property (50% fracture energy and buckling strength) and the water vapor barrier property (water vapor permeability and content evaporation rate) of the container. Specifically, for the laminate, the 50% fracture energy measured by the DuPont impact test carried out at -5°C was 0.4 J or more, and the water vapor permeability was less than 0.20 g / (m 2 ·24h). The water vapor permeability was improved in all of Examples 1 to 3 as compared with Comparative Example 1. Also, for the container, the buckling strength was 30 N or more, and the content evaporation rate when stored in an environment of 40°C and 25% relative humidity for 2 weeks was 0.50% or less. The content evaporation rate was also improved in all of Examples 1 to 3 as compared with Comparative Example 1.

[0039] Also, in Example 2 and Example 3, although the laminate was made 20% or 40% thinner than Comparative Example 1 respectively, the same results as Comparative Example 1 were obtained for the water vapor barrier property. Also, results with no problem in practical use were obtained for the cold resistance impact property. Therefore, the configuration of the embodiment of the present invention in which the second base material layer is formed of a resin composition containing a hydrogenated petroleum resin is effective for reducing the amount of resin used.

[0040] As described above, the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that those having ordinary knowledge in the technical field to which the present invention pertains can conceive of various modifications or corrections within the scope of the technical idea described in the claims, and it is naturally understood that these also belong to the technical scope of the present invention.

Explanation of reference numerals

[0041] 10, 10A, 10B... laminate, 11, 13... first base material layer, 12, 14... second base material layer, 15... oxygen barrier layer, 151, 152... adhesive layer, 16... seal layer, 20... lid, 100... container.

Claims

1. A first layer formed of a first resin composition containing 1% by mass or more and 15% by mass or less of a first polyolefin and a petroleum resin, a second layer formed of a second resin composition containing 2% by mass or more and 60% by mass or less of an inorganic filler, 1% by mass or more and 15% by mass or less of a second polyolefin, and a petroleum resin, and the first and second polyolefins include polypropylene, polyethylene, or cyclic polyolefin, a laminate.

2. The laminate according to claim 1, including, in this order, the first layer, the second layer, and a third layer formed of a third resin composition containing the first polyolefin and a petroleum resin.

3. The laminate according to claim 2, including, in this order, the first layer, the second layer, an oxygen barrier layer, a fourth layer formed of a fourth resin composition containing the second polyolefin and a petroleum resin, and the third layer.

4. The laminate according to claim 3, including, in this order, the first layer, the second layer, the oxygen barrier layer, the fourth layer, the third layer, and a seal layer.

5. The laminate according to any one of claims 1 to 4, wherein the 50% fracture energy measured by the Dupont impact test performed in an environment of -5°C is 0.4 J or more.

6. The laminate according to any one of claims 1 to 5, having a water vapor permeability of less than 0.20 g / (m ２ ·24 h).

7. The laminate according to any one of claims 1 to 6, wherein either or both of the first polyolefin and the second polyolefin include highly stereoregular polypropylene.

8. The laminate according to claim 7, wherein the content of highly stereoregular polypropylene is 10% by mass or more with respect to the whole laminate.

9. The laminate according to claim 7 or 8, wherein the content of highly stereoregular polypropylene in the first resin composition is 5% by mass or more.

10. The laminate according to any one of claims 7 to 9, wherein the content of highly stereoregular polypropylene in the second resin composition is 10% by mass or more.

11. The laminate according to any one of claims 7 to 10, wherein either or both of the first polyolefin and the second polyolefin further include polyethylene.

12. The laminate according to any one of claims 1 to 11, wherein the total content of the first polyolefin and the second polyolefin is 70% by mass or more with respect to the whole laminate.

13. The laminate according to any one of claims 1 to 12, wherein the content of the petroleum resin is 1% by mass or more and 15% by mass or less based on the whole laminate.

14. The laminate according to any one of claims 1 to 13, wherein the content of the petroleum resin in the second resin composition is 2% by mass or more.

15. The laminate according to any one of claims 1 to 14, wherein the content of the inorganic filler is 1% by mass or more based on the whole laminate.

16. The laminate according to any one of claims 1 to 15, wherein the content of the inorganic filler in the second resin composition is 7% by mass or more.

17. A first layer formed of a first resin composition containing 1% by mass or more and 15% by mass or less of a first polyolefin and a petroleum resin, a second layer formed of a second resin composition containing a second polyolefin, 2% by mass or more and 60% by mass or less of an inorganic filler, and 1% by mass or more and 15% by mass or less of a petroleum resin and wherein the first and second polyolefins include a container containing polypropylene, polyethylene or cyclic polyolefin.

18. The container according to claim 17, comprising the first layer, the second layer, and a third layer formed of a third resin composition containing the first polyolefin and a petroleum resin in this order.

19. The container according to claim 18, comprising the first layer, the second layer, an oxygen barrier layer, a fourth layer formed of a fourth resin composition containing the second polyolefin and a petroleum resin, and the third layer in this order.

20. The container according to claim 19, comprising the first layer, the second layer, the oxygen barrier layer, the fourth layer, the third layer, and a seal layer in this order.

21. The container according to any one of claims 17 to 20, having a buckling strength of 30 N or more.

22. The container according to any one of claims 17 to 21, having a content evaporation rate of 0.50% or less when stored in an environment of 40°C and a relative humidity of 25% for 2 weeks.

23. A first layer formed of a first resin composition containing 1% by mass or more and 15% by mass or less of a first polyolefin and a petroleum resin, a second layer formed of a second resin composition containing a second polyolefin, 2% by mass or more and 60% by mass or less of an inorganic filler, and 1% by mass or more and 15% by mass or less of a petroleum resin and including The method for manufacturing a laminate includes a step of co-extrusion molding a laminate including the first and second polyolefins, which are polypropylene, polyethylene, or cyclic polyolefin.

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