Transport bags and packaging for silicone materials

Abstract

To provide a shipping bag for silicon material and a package body for the silicon material allowing contamination of the content of the silicon material to be suppressed even in a case where an outer bag is damaged during shipping.SOLUTION: A shipping bag for silicon material is provided with a first bag and a second bag placed in the first bag, wherein package material configuring the second bag includes a barrier layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a bag for transporting silicon materials and a package of silicon materials.

Background Art

[0002] Silicon materials such as silicon wafers used in the manufacture of semiconductor products and polysilicon which is a raw material of silicon wafers are generally transported in a state of being packed in double bags. As such double-packing bags, an inner bag composed of a laminate of plastic bags such as polyester, polyamide, and polyolefin, and an outer bag composed of a laminate having a barrier layer such as aluminum foil or silica-deposited polyester are known (see Patent Document 1). By providing a barrier layer on the outer bag, light-shielding properties, oxygen gas barrier properties, and the like can be achieved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When a package in which a silicon material is packed in the double-packing bag disclosed in Patent Document 1 above is subjected to an impact during transportation and the outer bag is damaged, since the inner bag does not have a barrier layer, there is a risk that the silicon material which is the content will be contaminated.

[0005] In view of the above problems, an object of the present disclosure is to provide a bag for transporting silicon materials and a package of silicon materials that can suppress contamination of the silicon material which is the content even if the outer bag is damaged during transportation.

Means for Solving the Problems

[0006] To solve the above problems, as one embodiment of the present disclosure, a transport bag for a silicone material comprises a first bag and a second bag disposed inside the first bag, wherein the second bag is disposed inside the first bag without being fixed to the first bag, and the packaging material constituting the second bag includes a barrier layer and a sealant layer located inside the second bag, wherein the sealant layer includes low-density polyethylene (LDPE) with substantially no slip agent added and linear low-density polyethylene (LLDPE) with substantially no slip agent added. In the sealant layer, the amount of low-density polyethylene (LDPE) blended is equal to or greater than the amount of linear low-density polyethylene (LLDPE), A transport bag for silicon material is provided in which, when volatile components are analyzed by GC / MS from a section of the sealant layer immersed in ethanol at 60°C for one week, the volatile components are not detected.

[0007] The barrier layer may contain silica or alumina, and the packaging material constituting the second bag is a laminated material having a resin substrate layer, the barrier layer, and a sealant layer in that order, wherein the sealant layer may be located on the inside of the second bag.

[0008] The resin substrate layer may be composed of a polyester resin or a polyamide resin, and the packaging material may be a laminated material further having an adhesive layer located between the resin substrate layer and the barrier layer, or a laminated material further having a resin layer containing a polyester resin located between the barrier layer and the sealant layer.

[0009] The packaging material constituting the second bag is a laminated material having a resin base layer, the barrier layer, a resin layer, and a sealant layer in that order, wherein the resin base layer and the resin layer may contain the same resin, and the sealant layer may be located on the inside of the second bag.

[0010] The packaging material constituting the second bag may be transparent, and the packaging material constituting the first bag is a laminated material having a resin base layer containing polyester resin and a sealant layer in that order, wherein the sealant layer may be located on the inside of the first bag.

[0011] The packaging material constituting the first bag may be made of a laminated material that does not include a barrier layer, or a laminated material that does not include a polyamide resin, and the thickness of the resin base layer of the packaging material constituting the first bag may be 8 μm to 30 μm.

[0012] As one embodiment of the present disclosure, a packaging body for a silicon material is provided, comprising a transport bag for the silicon material and the silicon material contained within the second bag of the transport bag for the silicon material. [Effects of the Invention]

[0013] According to this disclosure, it is possible to provide a transport bag for silicone materials and a packaging for silicone materials that can suppress contamination of the silicone material inside even if the outer bag is damaged during transport. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a perspective view showing a schematic configuration of one embodiment of a transport bag for a silicon material according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a perspective view showing a schematic configuration of one aspect of the first bag in one embodiment of the present disclosure. [Figure 3] Figure 3 is a perspective view showing a schematic configuration of one aspect of the second bag in one embodiment of the present disclosure. [Figure 4] Figure 4 is a partially enlarged cross-sectional view showing a schematic configuration of one embodiment of the first packaging material in one embodiment of the present disclosure. [Figure 5] Figure 5 is a partially enlarged cross-sectional view showing a schematic configuration of one embodiment of the second packaging material in one embodiment of the present disclosure. [Figure 6] Figure 6 is a partially enlarged cross-sectional view showing a schematic configuration of another embodiment of the second packaging material in one embodiment of the present disclosure. [Figure 7] Figure 7 is a partially enlarged cross-sectional view showing a schematic configuration of another embodiment of the second packaging material in one embodiment of the present disclosure. [Figure 8] FIG. 8 is a partially enlarged cutaway end view showing a schematic configuration of another aspect of the second packaging material in one embodiment of the present disclosure. [Figure 9] FIG. 9 is a partially enlarged cutaway end view showing a schematic configuration of one aspect of the sealant layer of the first packaging material in one embodiment of the present disclosure. [Figure 10] FIG. 10 is a partially enlarged cutaway end view showing a schematic configuration of another aspect of the sealant layer of the first packaging material in one embodiment of the present disclosure. [Figure 11] FIG. 11 is a partially enlarged cutaway end view showing a schematic configuration of one aspect of the sealant layer of the second packaging material in one embodiment of the present disclosure. [Figure 12] FIG. 12 is a partially enlarged cutaway end view showing a schematic configuration of another aspect of the sealant layer of the second packaging material in one embodiment of the present disclosure. [Figure 13] FIG. 13 is a perspective view showing a schematic configuration of one aspect of a package of a silicon material in one embodiment of the present disclosure. [Figure 14A] FIG. 14A is a mass spectrum showing the GC / MS analysis result of Sample 1. [Figure 14B] FIG. 14B is a mass spectrum showing the GC / MS analysis result of Sample 2. [Figure 14C] FIG. 14C is a mass spectrum showing the GC / MS analysis result of Sample 3.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, the shape, scale, and aspect ratio of each part may be altered or exaggerated from the actual object for the sake of ease of understanding. In this specification, numerical ranges expressed using "~" mean a range that includes the numerical values ​​before and after "~" as the lower and upper limits, respectively. In this specification, terms such as "film," "sheet," and "plate" are not distinguished from each other based on differences in naming. For example, "plate" is a concept that also includes components that may generally be called "sheet" or "film."

[0016] As shown in Figures 1 to 3, the transport bag 1 for silicone material according to this embodiment is a double-layered packaging bag comprising a first bag 10 and a second bag 20 placed inside the first bag 10. The first bag 10 is the so-called outer bag, and the second bag 20 is the so-called inner bag.

[0017] The first bag 10 and the second bag 20 are both packaging bags that become roughly cube-shaped (roughly rectangular) when unfolded, and are composed of first side films 11, 21, second side films 12, 22, first gusset films 13, 23, and second gusset films 14, 24. The first side film 11, the second side film 12, the first gusset film 13, and the second gusset film 14 are all composed of the first packaging material 30. The first side film 21, the second side film 22, the first gusset film 23, and the second gusset film 24 are all composed of the second packaging material 40. The outer dimensions of the second bag 20 should be such that it can be placed inside the first bag 10. That is, the first bag 10 is slightly larger than the second bag 20. The first bag 10 and the second bag 20 may not have the first gusset films 13, 23 and the second gusset films 14, 24. In this case, the first side films 11, 21 and the second side films 12, 22 can be heat-sealed at their three side edges so that the first surfaces 32A, 42A of their respective sealant layers 32, 42 face each other.

[0018] The first packaging material 30, which constitutes each film of the first bag 10 (first side film 11, second side film 12, first gusset film 13, second gusset film 14), has a resin base layer 31 having one side 31A and the other side 31B opposite to it, and a sealant layer 32 laminated on the side of the resin base layer 31A (see Figure 4). Note that the first packaging material 30 is not limited to a two-layer structure of resin base layer 31 and sealant layer 32. For example, other layers such as a resin layer or an adhesive layer may be provided between the resin base layer 31 and the sealant layer 32. Similarly, the other layer may be provided on the side of the resin base layer 31 opposite to the sealant layer 32, or on the side of the sealant layer 32 opposite to the resin base layer 31.

[0019] The second packaging material 40, which constitutes each film of the second bag 20 (first side film 21, second side film 22, first gusset film 23, second gusset film 24), has a resin base layer 41 having one side 41A and the other side 41B opposite to it, a barrier layer 43 laminated on the side of the resin base layer 41A, and a sealant layer 42 laminated on the barrier layer 43 (see Figure 5). In addition to the embodiment shown in Figure 5, the second packaging material 40 may also be laminated in the order of barrier layer 43, resin layer 44 containing polyethylene terephthalate (PET), and sealant layer 42 (see Figure 6), or resin base layer 41, barrier layer 43, resin layer 44, and sealant layer 42 (see Figure 7), or resin base layer 41, adhesive layer 45, barrier layer 43, and sealant layer 42 (see Figure 8). In addition, similar to the first packaging material 30 described above, the second packaging material 40 is not limited to the above layer configuration, and may also have other layers.

[0020] Examples of resin materials included in the resin layer 44 include polyester-based resin materials such as polyethylene (PE), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT). In the embodiment shown in Figure 7, the resin substrate layer 41 and the resin layer 44 may contain the same material or different materials, but it is preferable that they contain the same material. This makes it less likely for stress differences to occur on both sides of the barrier layer 43, and can suppress the occurrence of cracks in the barrier layer 43.

[0021] In Figure 7, one resin layer 44 is provided between the sealant layer 42 and the barrier layer 43, but multiple resin layers 44 may be provided. Furthermore, if multiple resin layers 44 are provided, the multiple resin layers 44 may contain the same material or different materials. For example, although not shown, when a resin substrate layer, barrier layer, first resin layer, second resin layer, and sealant layer are laminated in this order, the first resin layer may contain polyethylene terephthalate (PET) and the second resin layer may contain polyethylene (PE).

[0022] The adhesive layer 45 can be formed using an adhesive. Examples of adhesives include two-component urethane resin adhesives. More specifically, a two-component urethane resin adhesive is obtained by mixing a main component (Rock Paint Co., Ltd., Ru77t) and a curing agent (Rock Paint Co., Ltd., H-7). The adhesive layer 45 can be positioned inside or outside the barrier layer 43, but it is more preferable that it be positioned outside the barrier layer 43. When a bag is made using the second packaging material 40, the adhesive layer 45 is positioned outside the bag beyond the barrier layer 43, which prevents organic components from the adhesive layer 45 from moving into the bag. This prevents deterioration of the silicone material inside the bag when the silicone material is contained in the bag. The thickness of the adhesive layer 45 can be, for example, about 1 μm to 5 μm, and is preferably about 2 μm to 4 μm. If the thickness of the adhesive layer 45 is less than 1 μm, sufficient adhesive strength may not be obtained. On the other hand, if the thickness of the adhesive layer 45 is greater than 5 μm, the curing reaction will take longer, which may result in the adhesive layer 45 containing a larger amount of unreacted substances or residual solvents.

[0023] Furthermore, "inside the barrier layer" means that when the second bag 20 is made using the second packaging material 40, it is located inside the barrier layer 43 of the second packaging material 40. On the other hand, "outside the barrier layer" means that when the second bag 20 is made using the second packaging material 40, it is located outside the barrier layer 43 of the second packaging material 40.

[0024] The resin base layer 31 of the first packaging material 30 is composed of, for example, a polyester resin material such as polyethylene terephthalate (PET) or polybutylene terephthalate (PBT), and may be a single layer of one type of resin material or a laminate of two or more types of resin materials. The resin base layer 31 may contain a polyamide resin material such as nylon (Ny, registered trademark), but it is preferable that it does not contain such a polyamide resin material. By not containing a polyamide resin material in the resin base layer 31, the possibility of contaminating the silicone material, which is the contents, when opening the first bag 10 can be reduced. A layer of, for example, polyethylene (PE) may be included between the resin base layer 31 and the sealant layer 32.

[0025] The resin base layer 41 of the second packaging material 40 is composed of one resin material selected from, for example, polyester resin materials such as polyethylene (PE), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT), and polyamide resin materials such as nylon (registered trademark, Ny), or a laminate of two or more resin materials. It is preferable that the resin base layer 41 does not contain polyamide resin materials such as nylon (registered trademark). Caprolactam, a residual monomer of polyamide resin materials, may contaminate the silicon material that is the contents, but the second bag 20 has a barrier layer 43 located inside the resin base layer 41, which can suppress contamination by caprolactam. In this regard, if the resin base layer 41 contains a polyamide resin material, it cannot be ruled out that contamination of the silicon material by caprolactam contained in the resin base layer 41 may occur when the second bag 20 is opened. However, by not containing a polyamide resin material in the resin base layer 41, the possibility of contaminating the silicon material inside can be further reduced.

[0026] The thickness of the resin base layer 31 of the first packaging material 30 and the resin base layer 41 of the second packaging material 40 may be, for example, 8 μm to 30 μm, and preferably 10 μm to 27 μm. If the thickness is less than 8 μm, it will be difficult to maintain the shape of the first bag 10 and the second bag 20, which may worsen the workability when placing the silicone material in the transport bag 1 for the silicone material. If the thickness exceeds 30 μm, the first bag 10 and the second bag 20 will be difficult to deform, which may reduce the conformability of the first bag 10 and the second bag 20 when placing the silicone material in the transport bag 1 for the silicone material, degassing, and packaging.

[0027] The sealant layer 32 of the first packaging material 30 has a first surface 32A and a second surface 32B opposite to it. In the first packaging material 30, the second surface 32B of the sealant layer 32 is located on the side of the resin substrate layer 31. The sealant layer 32 may be a laminated structure having a first surface layer 321 located on the side of the first surface 32A, a second surface layer 322 located on the side of the second surface 32B, and an intermediate layer 323 sandwiched between the first surface layer 321 and the second surface layer 322 (see Figure 9), or it may be a single-layer structure having a first surface 32A and a second surface 32B (see Figure 10).

[0028] The sealant layer 32 may contain any heat-sealable resin component, such as polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, or carboxylic acid-modified cyclic polyolefins.

[0029] Examples of polyolefins include polyethylene such as low-density polyethylene (LDPE), medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene (LLDPE); polypropylene such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymer of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymer of propylene and ethylene); and ethylene-butene-propylene terpolymers.

[0030] Cyclic polyolefins are copolymers of olefins and cyclic monomers. Examples of olefin monomers that make up cyclic polyolefins include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers that make up cyclic polyolefins include cyclic alkenes such as norbornene; specifically, examples of cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene.

[0031] Carboxylic acid-modified polyolefins are polymers obtained by modifying polyolefins through block polymerization or graft polymerization with carboxylic acids. Examples of carboxylic acids used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0032] Carboxylic acid-modified cyclic polyolefins are polymers obtained by copolymerizing a portion of the monomers constituting a cyclic polyolefin with α,β-unsaturated carboxylic acids or their anhydrides, or by block polymerization or graft polymerization of α,β-unsaturated carboxylic acids or their anhydrides to a cyclic polyolefin.

[0033] As described later, the sealant layer 42 of the second packaging material 40 constituting the second bag 20 only needs to contain polyethylene such as low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE). Therefore, it is preferable that the sealant layer 32 of the first packaging material 30 constituting the first bag 10 also contains polyethylene such as low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE). However, the sealant layer 32 of the first packaging material 30 may be made of materials other than low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE) as long as it has equivalent sealing characteristics, such as having approximately the same sealing temperature as the polyethylene such as low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE) constituting the sealant layer 42 of the second packaging material 40, or achieving the desired sealing strength. If the sealing properties (e.g., sealing temperature conditions) of the sealant layer 32 of the first packaging material 30 and the sealant layer 42 of the second packaging material 40 are different, process problems may occur when the silicone material is placed in the transport bag 1 for the silicone material to produce the silicone material packaging 60.

[0034] The first surface layer 321 located on the first surface 32A side of the sealant layer 32 may be a layer containing low-density polyethylene (LDPE) with substantially no slip agent added, the second surface layer 322 located on the second surface 32B side may, similar to the first surface layer 321, be a layer containing low-density polyethylene (LDPE) with substantially no slip agent added, and the intermediate layer 323 sandwiched between the first surface layer 321 and the second surface layer 322 may be a layer containing linear low-density polyethylene (LLDPE) with substantially no slip agent added. In this embodiment, "substantially no slip agent added" means that the components that actually improve the slipperiness of the sealant surface as a slip agent are not added in an amount that actually affects the slipperiness of the sealant surface for the purpose of actually affecting the slipperiness of the sealant surface. Examples of slip agents include particles such as calcium carbonate or talc, and surfactants such as silicone resin or quaternary ammonium salt compounds.

[0035] The sealant layer 42 of the second packaging material 40 has a first surface 42A and a second surface 42B opposite to it, similar to the sealant layer 32 of the first packaging material 30. In the second packaging material 40, the second surface 42B of the sealant layer 42 is located on the resin substrate layer 41 side. The sealant layer 42 may be a laminated structure having a first surface layer 421 located on the first surface 42A side, a second surface layer 422 located on the second surface 42B side, and an intermediate layer 423 sandwiched between the first surface layer 421 and the second surface layer 422 (see Figure 11), or it may be a single-layer structure having a first surface 42A and a second surface 42B (see Figure 12).

[0036] The sealant layer 42 may contain polyethylene such as low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE), and it is preferable that it contains low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE) that is substantially free of slip agents.

[0037] Since the sealant layer 42 is located in the innermost layer of the second bag 20, if volatile components (such as outgassing components originating from the sealant layer 42) from the sealant layer 42 adhere to the polysilicon or silicon wafer, which are the contents, it may cause defects in semiconductor devices manufactured using the silicon wafer. Therefore, it is desirable to minimize the amount of volatile components originating from the sealant layer 42. To reduce the amount of volatile components originating from the sealant layer 42, it is desirable to make the thickness T42 of the sealant layer 42 as thin as possible. By making the thickness T42 of the sealant layer 42 relatively thin, the volatile components originating from the sealant layer 42 are released to the outside of the film, thus reducing the amount of volatile components originating from the sealant layer 42. On the other hand, if the thickness T42 of the sealant layer 42 is made too thin, its resistance to mechanical properties such as tensile strength will decrease, which may impair its function as a bag for packaging contents. In this respect, linear low-density polyethylene (LLDPE) has higher elasticity and greater resistance to bending compared to low-density polyethylene (LDPE). Therefore, by using linear low-density polyethylene (LLDPE) as the sealant layer 42, the thickness T42 of the sealant layer 42 can be made relatively thinner.

[0038] Furthermore, since the resin case 51 is placed in the second bag 20 and then de-aeroded from the second bag 20 for packaging, the sealant layer 42 contained in the second packaging material 40 that constitutes the second bag 20 is required to have good conformability. In this respect as well, linear low-density polyethylene (LLDPE) has relatively high elasticity, so by using linear low-density polyethylene (LLDPE), the conformability of the sealant layer 42 can be improved.

[0039] If the sealant layer is composed of a single layer of linear low-density polyethylene (LLDPE), the indentation modulus of the sealant layer composed of a single layer of linear low-density polyethylene (LLDPE) can be adjusted to approximately 150 MPa to 600 MPa, thus allowing for a reduction in the thickness of the sealant layer. Furthermore, even considering the need for good conformability of the sealant layer, it can be said that a single layer of linear low-density polyethylene (LLDPE) is preferable. However, because the polymerization pressure of linear low-density polyethylene (LLDPE) is lower than that of low-density polyethylene (LDPE), low-molecular-weight components are more easily volatile in linear low-density polyethylene (LLDPE) compared to low-density polyethylene (LDPE). Therefore, even if the thickness of the sealant layer can be reduced when the sealant layer is composed of a single layer of linear low-density polyethylene (LLDPE), there is a risk that the silicon material may be contaminated by volatile components originating from the sealant layer. Furthermore, since linear low-density polyethylene (LLDPE) tends to have lower slipperiness than low-density polyethylene (LDPE), if the sealant layer is composed of a single layer of linear low-density polyethylene (LLDPE), there is a risk that the slipperiness of the surface of the sealant layer will be low. Since it is preferable that the sealant layer 42 used in the second bag 20 does not contain substantially any slip agents that may become foreign matter, it is preferable to improve the slipperiness by means other than the use of slip agents. In this embodiment, the intermediate layer 423 containing linear low-density polyethylene (LLDPE) may be sandwiched between a first surface layer 421 and a second surface layer 422 containing low-density polyethylene (LDPE). Therefore, in the sealant layer 42 of the second bag 20, the thickness T42 can be made relatively thin, the conformability and slipperiness are good, and it is possible to prevent the volatilization of low-molecular-weight components from the linear low-density polyethylene (LLDPE) contained in the intermediate layer 423.

[0040] The sealant layers 32 and 42 of the single-layer structure shown in Figures 10 and 12 may contain low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). In these sealant layers 32 and 42, the mixing ratio of low-density polyethylene (LDPE) to linear low-density polyethylene (LLDPE) should be approximately 50:50 to 70:30. By having a larger amount of low-density polyethylene (LDPE) than linear low-density polyethylene (LLDPE), the amount of low-density polyethylene (LDPE) present on the first surface 32A and 42A side of the sealant layers 32 and 42 can be increased, and the effect of reducing the thickness T32 and T42 of the sealant layers 32 and 42 by the linear low-density polyethylene (LLDPE) is achieved, that is, the effect of preventing the volatilization of low-molecular-weight components. Furthermore, when viewed in the thickness direction of the sealant layers 32 and 42, low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) may be substantially uniformly present, or the low-density polyethylene (LDPE) may be unevenly distributed on the first surface 32A, 42A side and the second surface 32B, 42B side.

[0041] The thicknesses T32 and T42 of the sealant layers 32 and 42 can be appropriately set according to the thickness of the first bag 10 made of the first packaging material 30, the thickness of the second bag 20 made of the second packaging material 40, etc., but for example, a thickness of about 35 μm to 100 μm is sufficient.

[0042] In the embodiments shown in Figures 9 and 11, the first surface layers 321, 421 and the second surface layers 322, 422, which also contain low-density polyethylene (LDPE), are arranged with intermediate layers 323, 423 in between. This allows the internal stress on one side of the sealant layers 32, 42 to cancel out to some extent the internal stress on the other side, thereby suppressing curling of the sealant layers 32, 42. Furthermore, in the embodiments shown in Figures 9 and 11, the thicknesses T321, T322, T421, and T422 of the first surface layers 321, 421 and the second surface layers 322, 422 are all thinner than the thicknesses T323, T423 of the intermediate layers 323, 423. The thicknesses T321, T322, T421, and T422 of the first surface layers 321, 421 and the second surface layers 322, 422, respectively, are thinner than the thicknesses T323, T423 of the intermediate layers 323, 423, thereby providing the sealant layers 32, 42 with a predetermined degree of conformability. The ratio of the thicknesses T321, T421 of the first surface layers 321, 421 to the thicknesses T323, T423 of the intermediate layers 323, 423 should be approximately 1:1 to 10, and preferably approximately 1:2 to 3. With this thickness ratio within the above range, sufficient conformability is provided to the sealant layers 32, 42 by the low-density linear polyethylene (LLDPE) contained in the intermediate layers 323, 423, and the indentation modulus of the sealant layers 32, 42 can be set to the range of 300 MPa to 500 MPa. The indentation modulus can be measured using a microhardness tester (product name "PICODENTOR HM500," manufactured by Fischer Instruments).

[0043] It is known that the seal strength of a sealant can be controlled by the sealing temperature, sealing pressure, sealing time, etc., during heat sealing. Generally, the seal strength tends to improve as the sealing temperature increases, but if the sealing temperature is too high, the sealant may melt more than necessary, which may actually decrease the seal strength. In this embodiment, under heat sealing conditions of a sealing temperature of 150°C, a sealing pressure of 0.1 MPa, and a sealing time of 1 second, the seal strength when the first surfaces 32A and 42A of the sealant layers 32 and 42 are sealed together should be 30 N / 15 mm or more, and preferably 50 N / 15 mm or more and less than 60 N / 15 mm. If the seal strength is less than 30 N / 15 mm, there is a risk that the heat-sealed portion (e.g., the upper heat-sealed portions HST1, HST2, etc. (see Figure 13)) of the silicone material transport bag 1, which has first and second bags 10, 20 composed of first and second packaging materials 30, 40 having sealant layers 32, 42, may peel off during transport of the silicone material transport bag 1.

[0044] As described above, from the viewpoint of relatively reducing the thickness T42 of the sealant layer 42, it is considered preferable to use linear low-density polyethylene (LLDPE) as the constituent material of the sealant layer 42. However, in a sealant layer composed of linear low-density polyethylene (LLDPE), the sealing temperature required to obtain a predetermined sealing strength becomes relatively high. In this regard, in this embodiment, by including low-density polyethylene (LDPE) in the first surface layer 421 of the sealant layer 42, the sealing temperature required to obtain a predetermined sealing strength can be relatively reduced.

[0045] In this embodiment, the haze of the sealant layer 42 should be 25% or less, and preferably 20% or less. A haze of 20% or less in the sealant layer 42 allows for good visibility inside the second bag 20. Furthermore, before packaging the silicone material in a transport packaging for the silicone material, it is possible to check whether or not foreign matter is adhering to the first surface 41A of the sealant layer 42, thereby preventing contamination of the silicone material. The haze of the sealant layer 42 can be measured, for example, using a haze meter (product name: HM-150, manufactured by Murakami Color Research Institute Co., Ltd.) in accordance with JIS-K7136.

[0046] The sealant layers 32 and 42 having the above-described configuration can be manufactured using conventionally known film formation methods. For example, the sealant layers 32 and 42 having the configurations shown in Figures 9 and 11 can be manufactured by laminating the second surface layer 322 and 422, the intermediate layer 323 and 423, and the first surface layer 321 and 421 using coating methods such as die coating and inflation. Similarly, the sealant layers 32 and 42 having the configurations shown in Figures 10 and 12 can be manufactured using the above-mentioned coating methods, extrusion inflation methods, etc.

[0047] The barrier layer 43 of the second packaging material 40 in this embodiment may be, for example, a vapor-deposited film obtained by depositing an inorganic oxide such as silica or alumina onto a PET layer, for example. The presence of the barrier layer 43 in the second packaging material 40 can suppress the intrusion of gases and the like that contaminate the surface of the silicon material, which is the contents, from outside the second bag 20. The barrier layer 43 may also be a metal vapor-deposited film obtained by depositing a metal such as aluminum onto a resin substrate layer 41 or a resin layer 44, or a metal foil such as aluminum. When the barrier layer 43 is one of these metal vapor-deposited films or metal foils, transparency is not ensured in the second bag 20, but the second bag 20 can be given not only barrier properties but also light shielding properties. Furthermore, in this embodiment, since the sealant layer 42 has a predetermined transparency, it is possible to more easily confirm whether or not foreign matter is attached to the first surface 42A of the sealant layer 42 in the second bag 20.

[0048] As described above, the sealant layers 32 and 42 have a degree of transparency that allows the inside of the transport bag 1 (see Figure 1) to be visible when the silicone material is packaged in the transport bag 1. Therefore, it is desirable that the first packaging material 30 and the second packaging material 40 having the sealant layers 32 and 42 also have a degree of transparency that allows the inside of the transport bag 1 to be visible. From this viewpoint, the haze of the first packaging material 30 and the second packaging material 40 in this embodiment should be, for example, 30% or less, and preferably 25% or less. If the haze of the first packaging material 30 and the second packaging material 40 exceeds 30%, the visibility of the inside of the transport bag 1 for the silicone material, which has the first bag 10 and the second bag 20 manufactured from the first packaging material 30 and the second packaging material 40 respectively, may deteriorate, or it may become difficult to confirm whether or not foreign matter is attached to the first surfaces 32A and 42A of the sealant layers 32 and 42 in the transport bag 1 for the silicone material. The haze of the first packaging material 30 and the second packaging material 40 can be measured, for example, using a haze meter (product name: HM-150, manufactured by Murakami Color Research Institute Co., Ltd.) in accordance with JIS-K7136.

[0049] Here, low-density polyethylene (LDPE with substantially no added slip agent, manufactured by Ube Maruzen Polyethylene Co., Ltd., product name: UBE Polyethylene B128) is used as the constituent material of the first surface layer 421, and low-density polyethylene (LDPE with substantially no added slip agent, manufactured by Ube Maruzen Polyethylene Co., Ltd., product name: UBE Polyethylene B128) and linear low-density polyethylene (LLDPE with substantially no added slip agent, manufactured by Prime Polymer Co., Ltd., product name: UBE Polyethylene B128) are used as the constituent materials of the intermediate layer 423. Using a molten mixture of Tozex 3500ZA (mixing ratio = 1:1 (by mass)), and low-density polyethylene (LDPE with substantially no added slip agent, manufactured by Ube Maruzen Polyethylene Co., Ltd., product name: UBE Polyethylene B128) as the constituent material of the second surface layer 422, a sealant layer 42 (first surface layer 421 (film thickness: 8 μm), intermediate layer 423 (film thickness: 24 μm), second surface layer 422 (film thickness: 8 μm)) having the structure shown in Figure 11 was fabricated by multilayer co-extrusion inflation deposition (Sample 1).

[0050] Further, pellets of low-density polyethylene (LDPE with substantially no slip agent added, manufactured by Ube Maruzen Polyethylene Co., Ltd., product name: UBE Polyethylene B128) and pellets of linear low-density polyethylene (LLDPE with substantially no slip agent added, manufactured by Prime Polymer Co., Ltd., product name: Ultra Zex 3500ZA) were melt-mixed at a blending ratio of 7:3 (by mass), and a sealant layer 42 (thickness: 40 μm) having the configuration shown in FIG. 12 was produced by an inflation film-forming method (Sample 2).

[0051] Furthermore, a sealant layer (thickness: 50 μm) made of non-additive linear low-density polyethylene (non-additive LLDPE, manufactured by Tama Poly Co., Ltd., product name: NB-1) was prepared (Sample 3).

[0052] Sections of the sealant layers of Samples 1 to 3 cut into 100 mm × 25 mm were immersed in ethanol at 60°C for 1 week, and then the volatile components from the sections were analyzed by GC / MS under the following conditions to obtain mass spectra. The obtained mass spectra are shown in FIGS. 14A to 14C.

[0053] <GC / MS Conditions> · Gas chromatograph: GCMS-QP2010 (manufactured by Shimadzu Corporation) · Column: 670-15003-03 (length: 30 mm, inner diameter: 0.25 mm, manufactured by Shimadzu Corporation) · Column oven temperature: 50°C · Injection volume: 1 μL · Carrier gas: He (57.1 mL / min) · Vaporization chamber temperature setting: 300°C · Measurement mode: Split

[0054] As shown in the mass spectra in Figures 14A to 14C, no volatile components were detected in the sealant layers of samples 1 and 2, but volatile components were detected in the sealant layer of sample 3. It can be inferred that the volatilization of low-molecular-weight components from the sealant layer can be prevented by having the first portion located on the first surface 42A side, as in samples 1 and 2, contain low-density polyethylene (LDPE), and the second portion located on the second surface 42B side contain linear low-density polyethylene (LLDPE).

[0055] Furthermore, the indentation modulus of sections cut to the desired size from the sealant layers of samples 1 to 3 was measured in accordance with ISO 14577:2015, under an atmosphere of 23°C ± 2°C and 60% RH ± 5% RH. First, the sections cut to a size of 20 mm × 20 mm were fixed to a commercially available microscope slide (hereinafter referred to as "first microscope slide") with the first surface 42A facing upwards, using adhesive resin (product name "Aron Alpha (registered trademark) General Use," manufactured by Toagosei Co., Ltd.). Specifically, the adhesive resin was dropped onto the center of the first microscope slide (product name "Slide Glass (Cut Type) 1-9645-11," manufactured by AS ONE Corporation). At this time, only one drop of adhesive resin was dropped so as not to spread it and so as not to spill out from the section when it was spread as described later. Subsequently, the section was brought into contact with the first slide glass so that the first surface 42A side was facing upwards and the adhesive resin was positioned in the center of the section. The adhesive resin was spread between the first slide glass and the section to temporarily bond them together. Then, another new slide glass (hereinafter referred to as "second slide glass") was placed on top of the section to obtain a laminate of first slide glass / adhesive resin / section / second slide glass. Next, a weight of 30g to 50g was placed on the second slide glass and left at room temperature for 12 hours. After that, the weight and second slide glass were removed and used as the measurement sample. This measurement sample was then fixed to the measurement stage of a microhardness tester (product name: PICODENTOR HM500, manufactured by Fischer Instruments) which was set up parallel to a vibration isolation table. To prevent the measurement sample from moving, the four sides of the first slide glass were secured with tape (product name: Cellotape®, manufactured by Nichiban Co., Ltd.). Next, on the first face 42A of the section, the indentation modulus (MPa) was measured using an ultra-microload hardness tester (Picodenter HM500, Fischer Instruments) equipped with a Vickers indenter (a square pyramidal diamond indenter with a 136° face angle) under the following conditions: indentation speed of 0.15 μm / sec, indentation depth of 3 μm, holding time of 5 seconds, and withdrawal speed of 0.15 μm / sec. Measurements were taken at least five different locations on each section, and the average of these measurements was taken as the indentation modulus value for the sealant under those conditions.

[0056] As a result, the indentation modulus of sample 1 was 457.3 MPa, the indentation modulus of sample 2 was 371.6 MPa, and the indentation modulus of sample 3 was 159.0 MPa. Although the indentation modulus of samples 1 and 2 is higher than that of sample 3, it is presumed that they have sufficient elasticity and flexibility to exhibit sufficient conformability for practical use. Furthermore, it is presumed that the sealant layers of samples 1 and 2 can ensure sufficient transparency.

[0057] Furthermore, the first surfaces of the sealant layers of samples 1 to 3 were heat-sealed at sealing temperatures of 110°C, 120°C, 130°C, 140°C, and 150°C. Heat-sealed test pieces with a width of 15 mm including the heat-sealed portion were taken, and the seal strength (N / 15 mm) of the heat-sealed test piece at each sealing temperature was determined in accordance with JIS-Z1711.

[0058] As a result, under the condition of a sealing temperature of 130°C, the sealing strength of sample 1 was 13.7 N / 15 mm, the sealing strength of sample 2 was 9.4 N / 15 mm, while the sealing strength of sample 3 was 2.3 N / 15 mm. Furthermore, under the condition of a sealing temperature of 140°C, the sealing strength was 26.1 N / 15 mm, the sealing strength of sample 2 was 55.7 N / 15 mm, while the sealing strength of sample 3 was 9.2 N / 15 mm. From these results, it can be inferred that the sealant layers of samples 1 and 2 can achieve higher sealing strength at lower sealing temperatures compared to the sealant layer of sample 3. However, under the conditions of sealing temperatures of 110°C and 120°C, none of samples 1 to 3 could obtain satisfactory sealing strength.

[0059] The first bag 10 is configured such that the first surface 32A of each sealant layer 32 of the first side film 11, second side film 12, first gusset film 13, and second gusset film 14 is located on the innermost side, and the other side 31B of the resin substrate layer 31 is located on the outermost side. The second bag 20 is configured such that the first surface 42A of each sealant layer 42 of the first side film 21, second side film 22, first gusset film 23, and second gusset film 24 is located on the innermost side, and the other side 41B (see Figures 5 and 7) of the resin substrate layer 41 or the barrier layer 43 (see Figure 6) is located on the outermost side.

[0060] In each of the first bag 10 and the second bag 20 described above, a first heat-sealed portion HS11, HS21 is formed by overlapping one of the two opposing side edges of the first side films 11, 21 with one of the two opposing side edges of the folded first gusset films 13, 23 and welding them together by heat sealing, and a second heat-sealed portion HS12, HS22 is formed by overlapping the other side edge of the first side films 11, 21 with one of the two opposing side edges of the folded second gusset films 14, 24 and welding them together by heat sealing. Furthermore, third heat-sealed portions HS13 and HS23 are formed by overlapping one of the two opposing side edges of the second side films 12 and 22 with the other side edge of the folded first gusset films 13 and 23 and welding them together by heat sealing. Fourth heat-sealed portions HS14 and HS24 are formed by overlapping the other side edge of the second side films 12 and 22 with the other side edge of the folded second gusset films 14 and 24 and welding them together by heat sealing. Bottom heat-sealed portions HSB1 and HSB2 are formed by overlapping the respective side edges of the first side films 11 and 21 and the second side films 12 and 22 and welding them together by heat sealing. The respective side edges of the first side films 11 and 21 and the second side films 12 and 22 that are located opposite the bottom heat-sealed portions HSB1 and HSB2 are not heat-sealed and form the openings 15 and 25 of the first bag 10 and the second bag 20.

[0061] With a large number of second bags 20, each with a first gusset film 23 and a second gusset film 24 folded in, stacked on top of each other, the opening 25 can be opened by suction-holding the first side film 21 or the second side film 22 and lifting it upward. A resin case 51 (see Figure 13) containing the silicone material 52 inside the second bag 20 is placed inside the opened opening 25, and the side edges of the first side film 21 and the second side film 22 at the opening 25 are overlapped and heat-sealed to form the upper heat-sealed portion HST2. Subsequently, with a large number of first bags 10, each with a first gusset film 13 and a second gusset film 14 folded in, stacked on top of each other, the opening 15 can be opened by suction-holding the first side film 11 or the second side film 12 and lifting it upward. A second bag 20, containing the resin case 51 and with the upper heat-sealed portion HST2 formed, is placed inside the opened opening 15. Then, the upper heat-sealed portion HST1 is formed by overlapping and heat-sealing the respective side edges of the first side film 11 and the second side film 12 at the opening 15. In this way, a packaging body 60 made of silicone material can be manufactured.

[0062] In the second bag 20 of this embodiment, the innermost sealant layer 42 contains low-density polyethylene (LDPE) on the first surface 42A side and linear low-density polyethylene (LLDPE) on the second surface 42B side. The linear low-density polyethylene (LLDPE) constituting the sealant layer 42 makes the thickness T42 of the sealant layer 42 relatively thin, improving its conformability, and the low-density polyethylene (LDPE) contained on the first surface 42A side of the sealant layer 42 prevents the volatilization of low-molecular-weight components from the linear low-density polyethylene (LLDPE). If the barrier layer 43 of the second packaging material 40 constituting the second bag 20 is a metal vapor-deposited film or metal foil, a predetermined transparency cannot be ensured, but if the barrier layer 43 is a metal vapor-deposited film or metal foil, barrier properties and light shielding properties can be given to the second bag 20. Furthermore, because a predetermined level of transparency is ensured in the sealant layer 42, it is easy to confirm whether or not foreign matter is adhering to the first surface 42A of the sealant layer 42 in the second bag 20.

[0063] The embodiments described above are provided to facilitate understanding of this disclosure and are not intended to limit it. Accordingly, each element disclosed in the embodiments above is intended to include all design modifications and equivalents that fall within the technical scope of this disclosure. [Explanation of symbols]

[0064] 1…Transport bag for silicone materials 10...First bag 20... Second bag 30,40…Packaging material 31,41...Resin base layer 32,42…Sealant layer 43… Barrier layer 44… Resin layer 52… Silicone materials 60… Silicone material packaging

Claims

1. A transport bag for silicone material, The device comprises a first bag and a second bag placed inside the first bag. The second bag is placed inside the first bag without being fixed to the first bag. The packaging material constituting the second bag includes a barrier layer and a sealant layer located on the inside of the second bag. The sealant layer comprises low-density polyethylene (LDPE) with substantially no slip agent added and linear low-density polyethylene (LLDPE) with substantially no slip agent added. In the sealant layer, the amount of low-density polyethylene (LDPE) is greater than or equal to the amount of linear low-density polyethylene (LLDPE), When volatile components were analyzed by GC / MS from sections of the sealant layer immersed in ethanol at 60°C for one week, the volatile components were not detected. Bags for transporting silicone materials.

2. In the sealant layer, the amount of low-density polyethylene (LDPE) is greater than the amount of linear low-density polyethylene (LLDPE). The sealant according to claim 1.

3. The sealant layer contains low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) in a mass ratio of 50:50 to 70:

30. A transport bag for silicone material according to claim 1.

4. The barrier layer contains silica or alumina. A transport bag for silicone material according to any one of claims 1 to 3.

5. The packaging material constituting the second bag is a laminated material having a resin substrate layer, the barrier layer, and the sealant layer in that order. The sealant layer is located inside the second bag. A transport bag for silicone material according to any one of claims 1 to 4.

6. The resin substrate layer is composed of polyester resin or polyamide resin. A transport bag for silicone material according to claim 5.

7. The packaging material constituting the second bag is a laminated material further having an adhesive layer located between the resin substrate layer and the barrier layer. A transport bag for silicone material according to claim 5 or 6.

8. The packaging material constituting the second bag is a laminated material further having a resin layer containing a polyester resin located between the barrier layer and the sealant layer. A transport bag for silicone material according to any one of claims 5 to 7.

9. The packaging material constituting the second bag is a laminated material having a resin substrate layer, the barrier layer, a resin layer, and the sealant layer in this order. The resin substrate layer and the resin layer contain the same resin. The sealant layer is located inside the second bag. A transport bag for silicone material according to any one of claims 1 to 4.

10. The packaging material that makes up the second bag described above is transparent. A transport bag for silicone material according to any one of claims 1 to 9.

11. The packaging material constituting the first bag is a laminated material having a resin base layer containing a polyester resin and a sealant layer in that order. The sealant layer of the first bag is located on the inside of the first bag. A transport bag for silicone material according to any one of claims 1 to 10.

12. The packaging material constituting the first bag is made of a laminated material that does not include a barrier layer. A transport bag for silicone material according to claim 10 or 11.

13. The packaging material constituting the first bag is made of a laminated material that does not contain polyamide resin. A transport bag for silicone material according to any one of claims 10 to 12.

14. The thickness of the resin substrate layer in the packaging material constituting the first bag is 8 μm to 30 μm. A transport bag for silicone material according to claim 11.

15. A transport bag for silicone material according to any one of claims 1 to 14, The silicone material contained in the second bag of the transport bag for the silicone material and A packaging body made of silicone material, equipped with the following features.

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