Multilayer molded container, bottle, tube, and recycled resin composition

Abstract

To provide a new use for recycled resin obtained from PET bottle caps. The multi-layer molded container has at least an inner layer containing a recycled resin obtained from PET bottle caps and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2.

Description

[Technical field]

[0001] An embodiment of the present invention relates to a multi-layer molded container, a bottle, a tube, a recycled resin composition, and a method for producing the multi-layer molded container. [Background technology]

[0002] Due to their characteristics of transparency, design, light weight, safety, etc., polyester bottles are used in many fields such as food, healthcare, cosmetics, and medicine, and their usage is expanding. Furthermore, in recent years, as a recycling-oriented society is promoted, polyester, the material of the polyester bottle body, is recycled into bottles, daily necessities, clothing, etc., achieving a high recycling rate.

[0003] For example, Patent Document 1 describes a biaxially oriented polyester film roll obtained by winding up a biaxially oriented polyester film made of a polyester resin composition containing particles and a polyester resin made from recycled PET bottles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 049998 Summary of the Invention [Problem to be solved by the invention]

[0005] On the other hand, for the caps of polyester bottles, polyolefin resins are often used because they are highly resistant to the contents and easy to mold. In addition, to improve the design of the caps, polyolefin resins are colored in a wide variety of ways using pigments. Therefore, the use of recycled caps is currently limited.

[0006] Therefore, an object of an embodiment of the present invention is to provide a new use for recycled resin obtained from PET bottle caps. [Means for solving the problem]

[0007] The present invention includes the following embodiments, but is not limited to the following embodiments.

[0008] One embodiment relates to a multi-layer molded container having at least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2. Another embodiment relates to a recycled resin composition that contains a recycled resin obtained by using a PET bottle cap and pigment 1 and is used for producing the multilayer molded container. Another embodiment relates to a method for producing a multilayer molded container, which includes molding an inner layer material containing recycled resin obtained by using PET bottle caps and pigment 1, and an outer layer material containing white pigment 2 and resin 2, by a blow molding method or an extrusion molding method. Effect of the Invention

[0009] According to one embodiment of the present invention, a multi-layer molded container is provided as a new application of recycled resin obtained from PET bottle caps. According to another embodiment of the present invention, a recycled resin composition suitable for multi-layer molded containers is provided. Furthermore, according to another embodiment of the present invention, a method for producing a multi-layer molded container is provided as a new application of recycled resin obtained from PET bottle caps. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the present invention will be described below, but the embodiment of the present invention is not limited to the following.

[0011] ≪Multilayer molded container≫ In an embodiment of the present invention, the multilayer molded container has at least an inner layer containing a recycled resin obtained by using a PET bottle cap and pigment 1, and an outer layer containing a white pigment 2 and resin 2. The inner layer may further contain resin 1. "Pigment 1" means a pigment contained in the inner layer, "resin 1" means a resin other than the recycled resin contained in the inner layer, "white pigment 2" means a white pigment contained in the outer layer, and "resin 2" means a resin contained in the outer layer. The multilayer molded container may further have any layer such as an adhesive layer and other resin layers.

[0012] From the viewpoint of design, identification, etc., PET bottle caps have a unique color for each product, and are formed from a resin composition containing a colorant corresponding to the color. When various used PET bottle caps are collected to obtain a recycled resin composition, the recycled resin composition contains many types of colorants and recycled resin. The recycled resin composition currently has limited recycling applications due to the color exhibited by the colorant. In order to expand the recycling applications, it is possible to separate the PET bottle caps by color after collecting them, or to separate and remove the colorant from the recycled resin composition, but this is difficult to put into practical use due to reasons such as complexity and cost. In response to these, the embodiment of the present invention has found a new use for PET bottle caps by adopting a multi-layer structure. According to the embodiment of the present invention, it is possible to reduce PET bottle cap waste, reduce the environmental load, and contribute to the realization of a resource-circulating society. In addition, from the viewpoint of manufacturing molded containers, it has the effect of being able to reduce raw material costs and manufacture containers at low cost, as well as having excellent design. However, in the embodiment of the present invention, various PET bottle caps such as PET bottle caps separated by color can be used, not limited to PET bottle caps that are not separated by color.

[0013] <Inner layer> The inner layer contains a resin obtained by using a PET bottle cap and a pigment 1. The inner layer may further contain optional components such as resin 1 and additives. The inner layer can be formed, for example, by using a recycled resin composition obtained by recycling a PET bottle cap. Since a PET bottle cap usually contains a resin, a pigment, an additive, etc., the recycled resin composition contains a recycled resin, a pigment, an additive, etc. obtained from them.

[0014] [Recycled resin] The recycled resin is a resin obtained by using a plastic bottle cap. Generally, polyethylene (PE) and / or polypropylene (PP) are used as the material for the plastic bottle cap. The polyethylene is, for example, high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), etc., and is preferably high density polyethylene. Therefore, the recycled resin may contain at least one selected from the group consisting of polyethylene and polypropylene, and preferably contains at least one selected from the group consisting of high density polyethylene and polypropylene. When the recycled resin contains at least one selected from the group consisting of high density polyethylene and polypropylene, a container with high rigidity tends to be obtained.

[0015] The content ratio of polyethylene and polypropylene in the recycled resin is not particularly limited. When a recycled resin composition is obtained by collecting PET bottle caps without any particular separation, the recycled resin in the composition usually contains polyethylene and polypropylene in a ratio of (mass (g) of polyethylene)>(mass (g) of polypropylene). The mass (g) of polyethylene:mass (g) of polypropylene is, for example, 60-95:5-40, 70-95:5-30, 70-95:5-30 (excluding 80-90:10-20), 65-93:7-35, or 70-90:10-30. However, the content ratio of polyethylene and polypropylene varies depending on the collection conditions such as the season and region in which used PET bottles are collected, and is not limited to the above range. The caps of PET bottles for cold drinks are often polyethylene caps, and the caps of PET bottles for hot drinks are often polypropylene caps. If necessary, PET bottle caps may be separated to obtain a recycled resin composition from specific PET bottle caps, and the ratio of the mass (g) of polyethylene to the mass (g) of polypropylene may be, for example, 95-100:0-5, or 0-60:40-100.

[0016] From the viewpoint of moldability, the ratio of the mass (g) of polyethylene to the mass (g) of polypropylene in the recycled resin is preferably 80-100:0-20. From the viewpoint of strength, it is more preferably 80-90:10-20. In an embodiment of the present invention, the composition ratio of the mass (g) of polyethylene to the mass (g) of polypropylene can be determined from the peak intensities of polyethylene and polypropylene by infrared spectroscopy as described in, for example, JIS K0117:2017.

[0017] The melt mass flow rate (MFR) of the recycled resin composition is preferably 0.1 to 10 g / 10 min, 1 to 10 g / min, or 2 to 10 g / 10 min. In an embodiment of the present invention, the MFR can be determined under conditions of 190° C. and a load of 2.16 kg in accordance with JIS K 7210-1:2014.

[0018] From the viewpoint of moldability, the density of the recycled resin composition is 930 to 970 kg / m 3 , or 950~970kg / m 3 In an embodiment of the present invention, the density can be determined by a water displacement method in accordance with JIS K 7112:2023.

[0019] The content of the recycled resin composition in the inner layer is, for example, 15 to 80 mass%, 20 to 80 mass%, 30 to 75 mass%, or 40 to 70 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 20 mass% or more, the amount of petroleum-derived resin can be reduced by using recycled materials. If it is 80 mass% or less, good moldability can be maintained in blow molding or extrusion molding.

[0020] The content of the recycled resin in the inner layer is, for example, 13 to 80 mass%, 18 to 80 mass%, 27 to 75 mass%, or 36 to 70 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 13 mass% or more, the amount of petroleum-derived resin can be reduced by using recycled materials. If it is 80 mass% or less, good moldability can be maintained in blow molding or extrusion molding.

[0021] [Pigment 1] The inner layer contains pigment 1. Pigment 1 includes a pigment derived from a plastic bottle cap contained in the recycled resin composition. The pigment derived from a plastic bottle cap means a pigment contained in a plastic bottle cap. Pigment 1 may further contain a pigment other than the pigment derived from the plastic bottle cap. The pigment derived from the plastic bottle cap may be referred to as "pigment 1a," and the pigment other than pigment 1a may be referred to as "pigment 1b."

[0022] Pigment 1a usually contains two or more pigments, for example, five or more, or ten or more pigments. Pigment 1a and pigment 1b may contain the same pigment or may not contain the same pigment. For example, pigment 1a may contain titanium oxide derived from a white cap, and pigment 1b may also contain titanium oxide. Examples of pigment 1 include organic pigments and inorganic pigments.

[0023] Examples of the organic pigment include azo pigments, quinacridone pigments, perylene pigments, isoindolinone pigments, diketopyrrolopyrrole pigments, phthalocyanine pigments, etc. More specifically, examples of the organic pigment include monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, quinacridone violet, etc. Pigment 1 may include at least one selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet; or may include at least one selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet (excluding Pigment Yellow 181 and Pigment Red 254). By including these pigments in pigment 1, the nucleating effect of the pigments makes it possible to maintain moldability during molding of multilayer molded containers such as blow bottles even when recycled materials are used. Pigment 1a, pigment 1b, or both may include these pigments.

[0024] Specific examples of azo pigments include CI Pigment Yellow 93, 95, 150, 151, 168, 169, 180, 181, CI Pigment Red 144, 208, 214, etc.; specific examples of quinacridone pigments include CI Pigment Red 122, 207, CI Pigment Violet 19, etc.; specific examples of perylene pigments include CI Pigment Red 149, 178, etc.; specific examples of isoindolinone pigments include CI Pigment Yellow 109, 110, 139, CI Pigment Orange 61, etc.; specific examples of diketopyrrolopyrrole pigments include CI Pigment Red 254, 264, CI Pigment Orange 71, etc.; and specific examples of phthalocyanine pigments include CI Pigment Green 7, 36, CI Pigment Blue 15, etc. Pigment 1 may, for example, contain at least one selected from the group consisting of Pigment Yellow 181 and Pigment Red 254. Pigment 1 may contain at least one selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet (excluding Pigment Yellow 181 and Pigment Red 254), and may further contain at least one selected from the group consisting of Pigment Yellow 181 and Pigment Red 254. Pigment 1a, Pigment 1b, or both may contain these pigments.

[0025] A specific example of Pigment Yellow 93 is Chromophthal Yellow 3GNP (manufactured by BASF), a specific example of Pigment Yellow 95 is Chromophthal Yellow GRP (manufactured by BASF), a specific example of Pigment Yellow 150 is Binamon Yellow 115002 (manufactured by Heubach), a specific example of Pigment Yellow 151 is PV Fast Yellow H4G (manufactured by Clariant), a specific example of Pigment Yellow 168 is Lionol Yellow K5G (manufactured by Toyo Color), a specific example of Pigment Yellow 169 is Lionol Yellow K2R (manufactured by Toyo Color), A specific example of Pigment Yellow 180 is PV Fast Yellow HG (manufactured by Clariant), a specific example of Pigment Yellow 181 is PV Fast Yellow H3R (manufactured by Clariant), a specific example of Pigment Red 144 is Chromophthal Red BRN (manufactured by BASF), a specific example of Pigment Red 208 is Grafthol Red HF2B (manufactured by BASF), a specific example of Pigment Red 214 is Chromophthal Red BN (manufactured by BASF), a specific example of Pigment Red 122 is Fastgen Super Magenta RE03 (manufactured by DIC), and Binamon Red 3 12201 (manufactured by Heubach), a specific example of Pigment Red 207 is Fastgen Super Scarlet GK (manufactured by DIC), a specific example of Pigment Violet 19 is Chrome Phthal Red 2020 (manufactured by BASF), a specific example of Pigment Red 149 is Paliogen Red K3580 (manufactured by BASF), a specific example of Pigment Red 178 is Paliogen Red K3911HD (manufactured by BASF), a specific example of Pigment Yellow 110 is Helmcol Yellow 3RLT (manufactured by Hermeta), a specific example of Pigment Yellow 139 is Helmcol Yellow 2140 (manufactured by Hermeta), a specific example of Pigment Orange 61 is Irgazin Orange K2890 (manufactured by BASF), a specific example of Pigment Red 254 is Chromophthal Red 2028 (manufactured by BASF), a specific example of Pigment Red 264 is Irgazin DPP Rubin TR (manufactured by BASF), a specific example of Pigment Orange 71 is Chromophthal DPP Orange TRP (manufactured by BASF), a specific example of Pigment Green 7 is Fastgen Green S (manufactured by DIC), a specific example of Pigment Green 36 is Fastgen Green 2YK (manufactured by DIC),A specific example of Pigment Blue 15 is Fastogen Blue AR-7E (manufactured by DIC Corporation).

[0026] Examples of inorganic pigments include titanium oxide, calcium carbonate, barium sulfate, zinc sulfide, iron oxide, ultramarine, cobalt blue, nickel titanium yellow, bismuth yellow, carbon black, and pearl pigments. The inorganic pigments may or may not be surface-treated. Examples of surface treatments include aluminum oxide treatment, silicon dioxide treatment, siloxane treatment (also called silicone treatment), and treatments combining two or more selected from these.

[0027] The content of pigment 1 is, for example, 1 to 30 mass%, 1 to 25 mass%, 1 to 20 mass%, 1 to 10 mass%, 1 to 8 mass%, or 1 to 6 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 1 mass% or more, the contents of the container tend to be sufficiently concealed. If it is 10 mass% or less, the drop impact strength of the container can be better maintained.

[0028] The content of pigment 1a is, for example, 0.01 to 4.0 mass%, 0.05 to 2.0 mass%, or 0.1 to 1.2 mass% based on the inner layer (in 100 mass% of the inner layer). The content of pigment 1b is, for example, 1 to 25 mass%, 1 to 20 mass%, 1 to 10 mass%, 1 to 8 mass%, or 1 to 6 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 1 mass% or more, the contents of the container tend to be sufficiently concealed. If it is 10 mass% or less, the drop impact strength of the container can be better maintained.

[0029] The content of the organic pigment is, for example, 0 to 5 mass%, 0 to 4 mass%, or 0 to 3 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 5 mass% or less, it is easy to maintain the appearance of the container white.

[0030] The content of the inorganic pigment is, for example, 1 to 25 mass%, 1 to 20 mass%, 1 to 10 mass%, 1 to 8 mass%, or 1 to 6 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 1 mass% or more, the contents of the container tend to be sufficiently concealed. If it is 10 mass% or less, the drop impact strength of the container can be better maintained.

[0031] Pigment 1 may contain white pigment 1. "White pigment 1" means a white pigment contained in the inner layer. Examples of the embodiment in which pigment 1 contains white pigment 1 include (1) the inner layer contains pigment 1a, and pigment 1a contains white pigment 1, and (2) the inner layer contains pigment 1a and pigment 1b, and pigment 1a and pigment 1b contain white pigment 1. White pigment 1 preferably contains titanium oxide.

[0032] The content of the white pigment 1 is, for example, 1 to 25 mass%, 1 to 20 mass%, 1 to 10 mass%, 1 to 8 mass%, or 1 to 6 mass% based on the inner layer (in 100 mass% of the inner layer). When it is 1 mass% or more, the contents of the container tend to be sufficiently concealed. When it is 10 mass% or less, the drop impact strength of the container can be better maintained.

[0033] When the white pigment 1 contains titanium oxide, the titanium oxide is preferably rutile type titanium oxide having low catalytic activity from the viewpoint of suppressing weather resistance. Furthermore, when the white pigment 1 contains rutile type titanium oxide, good concealing properties are easily obtained. From the viewpoint of concealing properties, the average particle size of the titanium oxide is preferably 0.10 to 0.30 μm, 0.20 to 0.28 μm, or 0.22 to 0.25 μm. The average particle size refers to the volume-based median diameter (D50) in dynamic light scattering particle size distribution (scattered light intensity basis). The average particle size can be measured, for example, under conditions of 25° C. using a dynamic light scattering particle size distribution measuring device LB-550 (manufactured by Horiba, Ltd.).

[0034] For example, the pigment 1 may contain titanium oxide treated with aluminum oxide, silicon dioxide, and siloxane. In order to provide the cap with a concealing property, it is preferable that titanium oxide is used as a white pigment, and it is more preferable that the cap is surface-treated as described above in order to improve weather resistance and dispersibility in addition to the concealing property. In addition, in terms of moldability and strength of the molded product, it is preferable to use a recycled resin composition obtained from a cap containing titanium oxide that has been surface-treated in this way for the multi-layer molded container. Whether or not the surface-treated titanium oxide is contained can be determined by a method such as ash measurement described in JIS K7250-1:2006 or fluorescent X-ray analysis described in JIS K0119-1:2008. The content of the surface-treated titanium oxide is, for example, 0.05 to 10.00 mass%, 0.05 to 5.00 mass%, 0.10 to 3.00 mass%, or 0.10 to 2.00 mass% based on the inner layer (in 100 mass% of the inner layer). When Pigment 1 contains surface-treated titanium oxide, the content of the organic pigment is preferably 5.00 mass% or less, and more preferably 2.00 mass% or less, based on the inner layer (in 100 mass% of the inner layer) from the viewpoint of hue. The organic pigment contained can be identified by gas chromatography mass spectrometry (GC / MS) as described in JIS K0123:2018.

[0035] [Resin 1] The inner layer may contain resin 1. Resin 1 may be a resin used in molding a multi-layer molded container, and is preferably a thermoplastic resin. Resin 1 may be a resin compatible with recycled resins, and examples of compatible resins include polyester, polystyrene, polyolefin, and aromatic nylon. Examples of polyolefins include high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (LLDPE). Examples of the resin include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-α-olefin random copolymer, ionomer resin, etc. Resin 1 preferably contains polyolefin, and more preferably contains polyethylene, polypropylene, or both of these.

[0036] The melt mass flow rate (MFR) of Resin 1 is preferably, for example, 0.01 to 50 g / 10 min, 0.1 to 2 g / 10 min, or 0.1 to 1 g / 10 min.

[0037] The content of Resin 1 is, for example, 10 to 80 mass%, 10 to 70 mass%, 10 to 50 mass%, 15 to 45 mass%, or 20 to 40 mass% based on the inner layer (in 100 mass% of the inner layer). When it is 10 mass% or more, good moldability can be maintained in blow molding or extrusion molding. When it is 50 mass% or less, the amount of petroleum-derived resin can be reduced.

[0038] [Optional ingredients] The inner layer may contain optional components such as additives in addition to the resin 1, as necessary. Examples of additives include metal soaps such as alkali metals, alkaline earth metals, and zinc; antioxidants; UV absorbers; light stabilizers; metal deactivators; surfactants such as nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants; antistatic agents; and flame retardants such as halogen-based, phosphorus-based, and metal oxide-based flame retardants.

[0039] Examples of metallic soaps include calcium stearate, magnesium stearate, barium stearate, zinc stearate, aluminum stearate, lithium stearate, calcium laurate, zinc laurate, and magnesium laurate.

[0040] Examples of the antioxidant include phenols and phosphites. Examples of the phenols include diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, etc. Examples of the phosphites include tris(2,4-di-tert-butylphenyl)phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol-diphosphite, etc.

[0041] Examples of ultraviolet absorbing agents include benzotriazoles and triazines. Examples of benzotriazoles include 2,2-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6[(2H-benzotriazol-2-yl)phenol]], 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol, and 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol. Examples of triazines include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol.

[0042] Examples of light stabilizers include hindered amines. Examples of hindered amines include bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], and polycondensates of dibutylamine·1,3,5-triazine·N,N-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine·N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine.

[0043] Examples of metal deactivators include 2,3-bis[[3-[3,5-di-tert-butyl-4-hydroxyphenyl]propionyl]]propionohydrazide.

[0044] The content of the optional components is, for example, 0.01 to 5 mass%, 0.05 to 3 mass%, or 0.1 to 1 mass% based on the inner layer (in 100 mass% of the inner layer). If it is 0.01 mass% or more, the effect of the added material can be fully exhibited. If it is 5 mass% or less, molding can be performed while suppressing migration such as bleeding out.

[0045] <Outer layer> The outer layer contains pigment 2 and resin 2. The outer layer may further contain optional components. The outer layer is a layer located outside the inner layer in the multilayer molded container. The outer layer may be a layer in contact with the inner layer, may contain optional layers such as an adhesive layer or other resin layer between the outer layer and the inner layer, or may further contain optional layers outside the outer layer. Examples of pigment 2, resin 2, and optional components are the same as the examples of pigment 1, resin 1, and optional components in the description of the inner layer.

[0046] [Pigment 2] The outer layer contains a pigment 2. Examples of the pigment 2 include organic pigments and inorganic pigments. Examples of the organic pigments and inorganic pigments are the same as the examples of the organic pigments and inorganic pigments in the description of the inner layer.

[0047] The content of pigment 2 is, for example, 2 to 20 mass%, 3 to 15 mass%, or 5 to 10 mass% based on the outer layer (in 100 mass% of the inner layer). If it is 2 mass% or more, the inner layer can be sufficiently concealed, so that a good appearance can be maintained. If it is 20 mass% or less, good moldability can be maintained in blow molding or extrusion molding.

[0048] The content of the organic pigment is, for example, 0 to 3 mass%, 0.1 to 3 mass%, 0.2 to 2 mass%, or 0.3 to 1 mass% based on the outer layer (in 100 mass% of the inner layer). If it is 0.1 mass% or more, a vivid appearance tends to be maintained. If it is 3 mass% or less, leaching into the contents can be suppressed.

[0049] The content of the inorganic pigment is, for example, 2 to 20 mass%, 3 to 15 mass%, or 5 to 10 mass% based on the outer layer (in 100 mass% of the inner layer). If it is 2 mass% or more, the inner layer can be sufficiently concealed, so that a good appearance tends to be maintained. If it is 20 mass% or less, good moldability can be maintained in blow molding or extrusion molding.

[0050] Pigment 2 may contain white pigment 2. "White pigment 2" means a white pigment contained in the outer layer. The content of white pigment 2 is, for example, 2 to 20 mass%, 3 to 15 mass%, or 5 to 10 mass% based on the outer layer (in 100 mass% of the inner layer). When it is 2 mass% or more, it tends to be possible to sufficiently conceal the inner layer and maintain a good white appearance. When it is 20 mass% or less, it is possible to maintain good moldability in blow molding or extrusion molding. It is preferable that white pigment 2 contains titanium oxide.

[0051] [Resin 2] The outer layer contains resin 2. Resin 2 may be a resin used in molding a multi-layer molded container, and is preferably a thermoplastic resin. Resin 2 preferably contains polyolefin, and more preferably contains polyethylene, polypropylene, or both. Examples of thermoplastic resins and polyolefins are the same as those of thermoplastic resins and polyolefins described in the description of the inner layer.

[0052] The content of resin 2 is, for example, 80 to 98 mass%, 85 to 97 mass%, or 90 to 95 mass% based on the outer layer (in 100 mass% of the inner layer). When it is 80 mass% or more, good moldability can be maintained in blow molding or extrusion molding. When it is 98 mass% or less, the inner layer can be sufficiently concealed, so that a good appearance tends to be maintained.

[0053] <Multilayer structure> The multi-layer molded container has a multi-layer structure. Examples of the multi-layer structure are given below. Inner / Outer Layer Inner layer / adhesive layer / outer layer Resin layer X / inner layer / outer layer Inner layer / Outer layer / Resin layer X Resin layer X / adhesive layer / inner layer / adhesive layer / outer layer Resin layer X / inner layer / resin layer Y / outer layer Resin layer X / inner layer / outer layer / resin layer Y Resin layer X / adhesive layer / inner layer / adhesive layer / resin layer Y / adhesive layer / outer layer Resin layer X / Resin layer Y / Inner layer / Outer layer Resin layer X / adhesive layer / resin layer Y / adhesive layer / inner layer / adhesive layer / outer layer

[0054] The adhesive layer is a layer that bonds two or more layers together, and may be a layer for bonding two layers together when the melting points of the two layers to be bonded are different. As the adhesive layer, a layer formed using an adhesive containing an acid-modified polyolefin, an ethylene-acrylic acid copolymer resin, an ethylene-vinyl acetate copolymer resin, etc. is known. Examples of commercially available adhesives include Nucrel (manufactured by Mitsui DuPont Polychemicals), Admer (manufactured by Mitsui Chemicals), and Mersen (manufactured by Tosoh Corporation).

[0055] The resin layer X and the resin layer Y are layers having various functions, such as an innermost layer for preventing direct contact between the contents and the inner layer containing recycled materials, a barrier layer, an outermost layer provided outside the outer layer to increase the smoothness of the container surface and further improve the design, etc. For example, the resin layer X and the resin layer Y may each independently be a layer having the same composition as the inner layer or the outer layer.

[0056] <Shape, usage, etc.> The shape of the multilayer molded container may be any shape, such as a bottle, a tube, a cylinder, a prism, a sphere, etc. Preferably, the shape is a bottle or a tube. According to an embodiment of the present invention, a bottle or a tube that is a multilayer molded container is obtained. The volume of the multilayer molded container is not particularly limited, and may be any volume, such as 350 mL, 500 mL, 1000 mL, 1500 mL, 2000 mL, etc. The thickness of the entire multilayer molded container may be uniform or non-uniform. For example, when the multilayer molded container is a bottle, the thicknesses of the mouth, shoulder, body, bottom, etc. of the bottle may be different from each other. The multilayer molded container may have a multilayer structure having an inner layer and an outer layer at least in a part. The multilayer molded container may have a multilayer structure in the entire container, or may have a multilayer structure in a part of the container, and the other part may have a single layer or another laminate structure.

[0057] The multi-layer molded container is suitable for various applications such as detergent, cosmetics, medicine, food, medical use, etc. The multi-layer molded container is preferably a detergent bottle or a detergent tube.

[0058] <Brightness and yellowness> The multilayer molded container may have a lightness (L* value) of at least a part of the surface of 80.0 to 99.0. The lightness (L* value) is the L* value in the L*a*b* color system defined by the International Commission on Illumination (CIE) and can be measured using a color difference meter. The lightness (L* value) is preferably 85.0 to 99.0, or 90.0 to 99.0. The lightness (L* value) can be adjusted by the lightness, thickness, etc. of the outer layer and the inner layer. When the multilayer molded container is a bottle or a tube, it is preferable that the lightness of at least the body portion satisfies the above range, and it is more preferable that the lightness of the entire bottle or tube satisfies the above range.

[0059] The multilayer molded container may have a yellowness index (YI value) of -15.0 to 15.0 on at least a part of the surface. The yellowness index (YI value) is a YI value determined according to JIS K 7373:2006 based on the XYZ color system defined by the International Commission on Illumination (CIE), and can be measured using a color difference meter. The yellowness index (YI value) is preferably -10.0 to 10.0, or -5.0 to 5.0. The yellowness index (YI value) can be adjusted by the hue, thickness, etc. of the outer layer and the inner layer. When the multilayer molded container is a bottle or a tube, it is preferable that the yellowness index of at least the body portion satisfies the above range, and it is more preferable that the yellowness index of the entire bottle or tube satisfies the above range.

[0060] <Total light transmittance> At least a part of the multilayer molded container may have a total light transmittance of 10.0% or less. The total light transmittance is preferably 5.0% or less, or 1.0% or less. The total light transmittance can be adjusted by the total light transmittance and thickness of the outer layer and the inner layer. When the multilayer molded container is a bottle or a tube, it is preferable that the total light transmittance of at least the body portion satisfies the above range, and it is more preferable that the total light transmittance of the entire bottle or tube satisfies the above range.

[0061] <Thickness> For example, the multilayer molded container has at least an inner layer and an outer layer, and at least a part of the multilayer molded container has a multilayer structure in which the inner layer has a thickness of 300 to 2,500 μm and the outer layer has a thickness of 50 to 1,000 μm. The multilayer molded container may entirely have a multilayer structure in which the inner layer and outer layer have thicknesses within the above ranges.

[0062] When the container is a bottle, the total thickness of the multilayer structure may be 500 to 3,000 μm, 700 to 2,500 μm, or 900 to 1,500 μm. If it is 500 μm or more, the strength of the bottle can be maintained. If it is 3,000 μm or less, uniform blow molding can be achieved. It is preferable that the thickness of at least a part of the multilayer structure of the bottle satisfies the above range, and it is more preferable that the thickness of the entire multilayer structure of the bottle satisfies the above range. Similarly, it is preferable that a part of the thickness of the inner layer, the thickness of the outer layer, and the thickness of the inner layer / thickness of the outer layer (ratio) below satisfies the following range, and it is more preferable that the entirety satisfies the following range. The thickness of the inner layer is, for example, 300 to 2,500 μm, 500 to 2,000 μm, or 700 to 1,500 μm. If it is 300 μm or more, the strength of the bottle can be maintained. If it is 2,500 μm or less, uniform blow molding can be achieved. The thickness of the outer layer is, for example, 50 to 1,000 μm, 60 to 500 μm, or 70 to 200 μm. If it is 50 μm or more, the inner layer can be sufficiently concealed. If it is 1,000 μm or less, uniform blow molding can be achieved. The thickness of the inner layer / the thickness of the outer layer (ratio) is, for example, 20 / 1 to 1 / 1, 15 / 1 to 3 / 1, or 12 / 1 to 5 / 1.

[0063] The total thickness of the laminated structure, in the case of a tube, may be 100 to 1,000 μm, 150 to 800 μm, or 200 to 600 μm. When it is 100 μm or more, the strength of the tube can be maintained. When it is 1,000 μm or less, a lightweight tube can be held. The thickness of the inner layer is, for example, 40 to 800 μm, 80 to 500 μm, or 100 to 300 μm. When it is 40 μm or more, the strength of the tube can be maintained. When it is 800 μm or less, a lightweight tube can be held. The thickness of the outer layer is, for example, 20 to 500 μm, 40 to 300 μm, or 60 to 200 μm. When it is 20 μm or more, the inner layer can be sufficiently concealed. When it is 500 μm or less, a lightweight tube can be held. The ratio of the thickness of the inner layer to the thickness of the outer layer is, for example, 10 / 1 to 1 / 2, 5 / 1 to 1 / 1, or 3 / 1 to 1 / 1.

[0064] The adhesive layer has a thickness of, for example, 10 to 100 μm. The resin layer X may have a thickness suitable for the function, material, etc. of the resin layer X, for example, 50 to 1,000 μm. The resin layer Y may have a thickness suitable for the function, material, etc. of the resin layer Y, for example, 50 to 1,000 μm.

[0065] <Recycled resin composition> The recycled resin composition according to the embodiment of the present invention is obtained by recycling a PET bottle cap. The recycled resin composition contains at least a recycled resin and a pigment 1a, and may further contain optional components. The recycled resin, the pigment 1a, and the optional components are as described above. The optional components may be additives contained in the PET bottle cap. The shape of the recycled resin composition may be, for example, pellet-like, powder-like, or granular, and is preferably pellet-like. The recycled resin composition is used to manufacture the multilayer molded container according to the embodiment described above.

[0066] The content of the recycled resin is, for example, 90.0 to 99.9 mass%, 95.0 to 99.8 mass%, or 98.0 to 99.5 mass% based on the recycled resin composition (100 mass% of the recycled resin composition). If it is 90.0 mass% or more, the amount of petroleum-derived resin can be reduced. If it is 99.9 mass% or less, the contents of the container are concealed, so that a good appearance can be maintained.

[0067] The content of pigment 1a is, for example, 0.01 to 10.00 mass%, 0.05 to 5.00 mass%, or 0.10 to 2.00 mass% based on the recycled resin composition (in 100 mass% of the recycled resin composition). When it is 0.01 mass% or more, the contents are concealed, so that a good appearance can be maintained. When it is 10.00 mass% or less, good moldability can be maintained in blow molding or extrusion molding. The content of organic pigment is, for example, 0 to 1 mass%, 0.001 to 1.00 mass%, or 0.01 to 0.50 mass%. The content of inorganic pigment is, for example, 0.00 to 10.00 mass%, 0.05 to 5.00 mass%, or 0.10 to 2.00 mass%.

[0068] The recycled resin composition can be obtained, for example, by a manufacturing method including crushing PET bottle caps to obtain a crushed product (crushing step), melt-kneading the crushed product to obtain a kneaded product (kneading step). The manufacturing method may further include any steps such as washing the PET bottle caps, drying the washed PET bottle caps, washing the crushed product, drying the washed crushed product, separating the crushed product, adding any component, and forming the kneaded product into a shape such as pellets.

[0069] The method for crushing the packaging material in the crushing step is not particularly limited, and examples thereof include methods using a jaw crusher, impact crusher, cutter mill, stamp mill, ring mill, roller mill, jet mill, and hammer mill.

[0070] In the kneading step, any component such as an additive may be added as necessary. The melt-kneading method is not particularly limited, and examples thereof include a method in which the mixture is mixed using a Henschel mixer, a tumbler, a disperser, or the like, and then melt-kneaded using a batch mixer such as a kneader, a roll mill, a super mixer, a Henschel mixer, a Schugie mixer, a vertical granulator, a high-speed mixer, a Furmatrix, a ball mill, a steel mill, a sand mill, a vibration mill, an attritor, or a Banbury mixer, a twin-screw extruder, a single-screw extruder, or a rotor-type twin-screw kneader. When the kneaded product is granulated into a shape such as pellets, a twin-screw extruder or a single-screw extruder can be preferably used.

[0071] <Manufacturing method for multi-layer molded containers> The manufacturing method of the multilayer molded container according to the embodiment of the present invention includes molding an inner layer material containing recycled resin and pigment 1 obtained by using a PET bottle cap, and an outer layer material containing white pigment 2 and resin 2 by a blow molding method or an extrusion molding method. The blow molding method may be, for example, an injection blow molding method, and the extrusion molding method may be, for example, a co-extrusion molding method. The inner layer material may further contain resin 1. The outer layer material may further contain a pigment other than white pigment 2. The recycled resin, pigment 1 (pigment 1a, pigment 1b), resin 1, pigment 2 (white pigment 2), resin 2, and optional components that can be used in the manufacturing method of the multilayer molded container are as described above.

[0072] The method for producing a multilayer molded container may be a method including molding an inner layer and / or an outer layer that satisfies at least one of the following (1) to (4). (1) When a laminate consisting of an inner layer and an outer layer is formed, the lightness (L* value) measured from the outer layer side is 80.0 to 99.0, 85.0 to 99.0, or 90.0 to 99.0. (2) When a laminate consisting of an inner layer and an outer layer is formed, the yellowness index (YI value) measured from the outer layer side is −15.0 to 15.0, −10.0 to 10.0, or −5.0 to 5.0. (3) The lightness (L* value) of the inner layer is 45.0 to 90.0, 70.0 to 85.0, or 75.0 to 82.0. (4) The total light transmittance of the outer layer is 90.0% or less, 60.0% or less, or 35.0% or less.

[0073] The brightness, yellowness, and total light transmittance can be adjusted by changing the type of the inner layer material and the outer layer material, the thickness of the inner layer and the outer layer, etc. In addition, as the values ​​of brightness, yellowness, and total light transmittance in the above (1) to (4), the same inner layer material and outer layer material as those used in producing a multilayer molded container according to the method for producing a multilayer molded container according to the embodiment of the present invention are used, and an inner layer, an outer layer, or a laminate composed of these is produced with the same thickness as that used in producing a multilayer molded container according to the method for producing a multilayer molded container according to the embodiment of the present invention, and the values ​​measured using the produced inner layer, outer layer, or a laminate composed of these can be adopted. The production method in this case may be, for example, a method using a film forming machine or a method using a heat press machine.

[0074] Preferred combinations of the inner layer and the outer layer include the following. An inner layer with a lightness (L* value) of 45.0 to 85.0 and an outer layer with a total light transmittance of less than 35.0% An inner layer with a lightness (L* value) of 75.0 to 90.0 and an outer layer with a total light transmittance of 35.0 to 40.0%

[0075] <Inner layer materials and outer layer materials> The material for the inner layer (sometimes referred to as the "inner layer material") can be prepared by kneading a recycled resin composition containing recycled resin and pigment 1a with resin 1, pigment 1b, and optional components as required. The material for the outer layer (sometimes referred to as the "outer layer material") can be prepared by kneading white pigment 2, resin 2, and optional components as required.

[0076] The inner layer material and the outer layer material may be materials that satisfy at least one of the following (1) to (6). (1) The MFR of the layer 1 having a thickness of 1,000 μm and formed using the inner layer material is 0.05 to 5 g / 10 min. (2) The MFR of the layer 2 having a thickness of 100 μm and formed using the outer layer material is 0.05 to 5 g / 10 min. (3) The lightness (L* value) of a laminate consisting of a layer 1 having a thickness of 1,000 μm formed using an inner layer material and a layer 2 having a thickness of 100 μm formed using an outer layer material, measured from the layer 2 side, is 80.0 to 99.0, 85.0 to 99.0, or 90.0 to 99.0. (4) A laminate consisting of a layer 1 having a thickness of 1,000 μm formed using an inner layer material and a layer 2 having a thickness of 100 μm formed using an outer layer material has a yellowness index (YI value) measured from the layer 2 side of -15.0 to 15.0, -10.0 to 10.0, or -5.0 to 5.0. (5) The lightness (L* value) of the layer 1 having a thickness of 1,000 μm formed using the inner layer material is 45.0 to 90.0, 70.0 to 85.0, or 75.0 to 82.0. (6) The layer 2 having a thickness of 100 μm and formed using the outer layer material has a total light transmittance of 90.0% or less, 60.0% or less, or 35.0% or less.

[0077] The MFR of the inner layer material can be adjusted by changing the type and content of Resin 1, the content of Pigment 1, etc. The MFR of the outer layer material can be adjusted by changing the type and content of Resin 2, the content of Pigment 2, etc. The brightness, yellowness, and total light transmittance can be adjusted by changing the type and content of the pigment contained in each layer, etc.

[0078] Preferable combinations of the inner layer material and the outer layer material are as follows. An inner layer material having a lightness (L* value) of 45.0 to 85.0 for layer 1, and an outer layer material having a total light transmittance of less than 35.0% for layer 2 The inner layer material has a lightness (L* value) of 75.0 to 90.0 for layer 1, and the outer layer material has a total light transmittance of 35.0 to 40.0% for layer 2.

[0079] MFR can be determined in accordance with JIS K 7210:-1:2014. Total light transmittance can be measured in accordance with JIS K 7375:2008. Lightness (L* value) is the L* value in the L*a*b* color system defined by the International Commission on Illumination (CIE) and can be measured using a colorimeter. Yellowness (YI value) is the YI value calculated in accordance with JIS K 7373:2006 based on the XYZ color system defined by the International Commission on Illumination (CIE) and can be measured using a colorimeter.

[0080] The amounts of recycled resin obtained using PET bottle caps, pigment 1, optionally used resin 1, white pigment 2, and resin 2 used may be the amounts that result in the content rates described in the description of the inner layer and outer layer of the multilayer molded container of the above embodiment.

[0081] Examples of embodiments are given below. The embodiments of the present invention are not limited to the following.

[0082] (1) A multi-layer molded container having at least an inner layer containing a recycled resin obtained by using PET bottle caps and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2. (2) At least an inner layer containing a recycled resin composition obtained by using a PET bottle cap and an outer layer containing a white pigment 2 and a resin 2; The recycled resin composition contains a recycled resin obtained by using a PET bottle cap and a pigment 1a derived from a PET bottle cap, and has a melt mass flow rate (MFR) of 2 to 10 g / 10 min. (3) A plastic bag having at least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, the inner layer being obtained by using a recycled resin composition, The recycled resin composition has a melt mass flow rate (MFR) of 0.1 to 10 g / 10 min and a density of 930 to 970 kg / m 3 and The multi-layer molded container, wherein the pigment 1 comprises aluminum oxide, silicon dioxide, and titanium oxide treated with siloxane. (4) At least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, The multilayer molded container, wherein the recycled resin contains polyethylene and polypropylene, and the ratio of the mass (g) of polyethylene to the mass (g) of polypropylene in the recycled resin is 80-90:10-20. (5) At least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, The multilayer molded container, wherein the recycled resin contains polyethylene and polypropylene, and the ratio of mass (g) of polyethylene to mass (g) of polypropylene in the recycled resin is 70-95:5-30. The ratio of mass (g) of polyethylene to mass (g) of polypropylene may be 70-95:5-30 (excluding 80-90:10-20). (6) At least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, The pigment 1 includes at least one pigment selected from the group consisting of Pigment Yellow 181 and Pigment Red 254. (7) At least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, A multi-layer molded container, wherein the pigment 1 includes at least one selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet. The pigment 1 may include at least one selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet (excluding Pigment Yellow 181 and Pigment Red 254).

[0083] (8) The multilayer molded container according to any one of (1) to (7) above, wherein the recycled resin contains at least one selected from the group consisting of polyethylene and polypropylene. (9) The multilayer molded container according to any one of (1) to (8) above, wherein the inner layer further contains a resin 1, and the resin 1 and the resin 2 each contain a polyolefin. (10) The multilayer molded container according to any one of (1) to (9), wherein the white pigment 2 contains titanium oxide. (11) The multilayer molded container according to any one of (1) to (10) above, wherein the content of the white pigment 2 is 2 to 20 mass % based on the outer layer. (12) The multilayer molded container according to any one of (1) to (11) above, wherein the pigment 1 includes a white pigment 1. (13) The multilayer molded container according to (12) above, wherein the white pigment 1 contains titanium oxide. (14) The multilayer molded container according to (12) or (13) above, wherein the content of the white pigment 1 is 1 to 25 mass % based on the inner layer. (15) The multilayer molded container according to any one of (1) to (14), which at least partially has a multilayer structure including the inner layer and the outer layer, the inner layer having a thickness of 300 to 2,500 μm, and the outer layer having a thickness of 50 to 1,000 μm. (16) The multilayer molded container according to any one of (1) to (15) above, wherein the lightness (L* value) of at least a part of the surface is 80.0 to 99.0. (17) A bottle, which is the multilayer molded container according to any one of (1) to (16) above. (18) A tube which is the multilayer molded container according to any one of (1) to (16) above. (19) A recycled resin composition containing a recycled resin obtained by using a PET bottle cap and pigment 1, which is used for producing the multilayer molded container according to any one of (1) to (16) above.

[0084] (20) A method for producing a multilayer molded container, comprising molding, by blow molding or extrusion molding, an inner layer material containing recycled resin obtained by using PET bottle caps and pigment 1, and an outer layer material containing white pigment 2 and resin 2. The multilayer molded container may be the multilayer molded container described in any one of (1) to (16) above. (21) A method for producing a multi-layer molded container having an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, comprising the steps of: A method for producing a multilayer molded container, comprising molding, by blow molding or extrusion molding, an inner layer material containing the recycled resin composition described in (19) above and an outer layer material containing a white pigment 2 and a resin 2. The multilayer molded container may be any of the multilayer molded containers described in (1) to (16) above. (22) The method for producing a multilayer molded container according to (20) or (21) above, wherein the inner layer material further contains a resin 1. (23) A method for producing a multilayer molded container according to any one of (20) to (22) above, comprising molding an inner layer and an outer layer that satisfy the following: When a laminate consisting of an inner layer and an outer layer is formed, the lightness (L* value) measured from the outer layer side is 80.0 to 99.0. (24) The method for producing a multilayer molded container according to any one of (20) to (23) above, wherein an inner layer that satisfies the following criteria is molded: The lightness (L* value) of the inner layer is 45.0 to 90.0. (25) The method for producing a multilayer molded container according to any one of (20) to (24) above, wherein an outer layer that satisfies the following criteria is molded: The outer layer has a total light transmittance of 90.0% or less. EXAMPLES

[0085] The embodiments of the present invention will be described with reference to the following examples, but the embodiments of the present invention are not limited to the following examples.

[0086] Example I <Preparation of inner layer material and outer layer material> The following raw materials for the inner layer material and the outer layer material were prepared. <Recycled resin composition derived from PET bottle caps> The plastic bottle caps were crushed, and the crushed material was melt-kneaded to obtain a pellet-shaped recycled resin composition containing the recycled resin and the pigment 1a. The composition and MFR of the recycled resin composition are as follows: Mass of polyethylene (g): mass of polypropylene (g) = 80:20 Pigment 1a content: 0.50% by mass MFR: 5g / 10min <Resin 1 (A)> (A-1) HDPE (Hi-Zex 6203B, manufactured by Prime Polymer Co., Ltd., MFR: 0.35g / 10min) (A-2) LLDPE (Neozex 2006H, manufactured by Prime Polymer Co., Ltd., MFR: 0.63g / 10min) (A-3) LDPE (Tosoh Corporation, Petrothene 170K, MFR: 1.0g / 10min) <Pigment 1b(B)> (B-1) Titanium oxide (Ishihara Sangyo Kaisha, Ltd., Typak PF-711, average particle size: 0.25 μm) (B-2) Heavy calcium carbonate (Whiten-H, manufactured by Shiraishi Calcium Co., Ltd., average particle size: 22 μm) (B-3) Zinc sulfide (Venator Sactris HD-S, average particle size: 0.30 μm)

[0087] <Resin 2> (C-1) HDPE (Hi-Zex 6203B, manufactured by Prime Polymer Co., Ltd., MFR: 0.35g / 10min) <Pigment 2> (D-1) Titanium oxide (Ishihara Sangyo Kaisha, Ltd., Typak PF-711, average particle size: 0.25 μm)

[0088] [Inner layer composition 1] Resin 1 (A-1) and the recycled resin composition derived from PET bottle caps were fed into a twin-screw extruder (manufactured by Japan Steel Works) from separate feed ports so that the mixture was 50% by mass of Resin 1 (A-1) and 50% by mass of the recycled resin composition derived from PET bottle caps, and melt-kneaded at 220°C to obtain inner layer composition 1, a pellet-shaped polyethylene-based inner layer material.

[0089] [Inner layer compositions 2-16] An inner layer composition was produced in the same manner as inner layer composition 1, except that the types and amounts (mass%) of resin 1 (A), pigment 1b (B), and recycled resin composition derived from PET bottle caps were changed as shown in Table 1.

[0090] A pressed sheet having a thickness of 1,000 μm was prepared using the inner layer composition at a temperature of 200° C. using a heat press machine, and the color was measured. A vernier caliper was used to measure the film thickness, and a color difference meter (SpectroColorMeterSE2000, manufactured by Nippon Denshoku Industries Co., Ltd.) was used to measure the color.

[0091] [Table 1]

[0092] [Outer layer material 1] An outer layer material 1 was prepared containing 100% by mass of resin 2 (C-1).

[0093] [Outer layer composition 2] Resin (C-1) and pigment (D-1) were fed into a twin-screw extruder (manufactured by Japan Steel Works) from separate feed ports so that the composition was 97% by mass of resin 2 (C-1) and 3% by mass of pigment 2 (D-1), and melt-kneaded at 220°C to obtain outer layer composition 2, which is a pellet-shaped polyethylene-based outer layer material.

[0094] [Outer layer composition 3-6] An outer layer composition was produced in the same manner as for outer layer composition 2, except that the blending amounts (mass %) of resin 2 (C-1) and pigment 2 (D-1) were changed as shown in Table 2.

[0095] A film having a thickness of 100 μm was produced using the outer layer composition by a film forming machine at a temperature of 200° C., and the total light transmittance was measured. A caliper was used to measure the film thickness, and a haze meter (BYK, Hazeguard Plus) was used to measure the total light transmittance.

[0096] [Table 2]

[0097] <Production and evaluation of multi-layer molded containers> Multilayer molded containers were produced using the inner layer materials (inner layer compositions 1 to 16) and the outer layer materials (outer layer compositions 1 to 6).

[0098] [Example 1] Using the inner layer composition 1 and the outer layer composition 2, direct blow molding was performed at a temperature of 280° C. using a direct multilayer blow molding machine (manufactured by Nissei ASB Co., Ltd.) to produce a blow-molded container having a polyolefin-based multilayer structure. The blow-molded container had a capacity of 500 mL and a cylindrical bottle shape with a body diameter of 70 mm, and was molded so that the total thickness at the center of the body (near the center between the shoulder and bottom of the container) was 1,100 μm, the thickness of the inner layer was 1,000 μm, and the thickness of the outer layer was 100 μm.

[0099] [Examples 2 to 28, Comparative Examples 1 to 6, and Reference Example 1] A blow-molded container having a polyolefin-based multilayer structure was produced in the same manner as in Example 1, except that the types and layer structures of the inner layer composition and outer layer composition were changed as shown in Table 3. [Example 29] A blow molded container having a polyolefin-based multilayer structure was produced in the same manner as in Example 23, except that the multilayer structure was an inner layer / adhesive layer / outer layer, and a modified polyolefin (Admer NF518, manufactured by Mitsui Chemicals, Inc.) was used as the adhesive layer. Molding was performed so that the thickness of the adhesive layer at the center of the body was 20 μm. [Example 30] A blow molded container having a polyolefin-based multilayer structure was produced in the same manner as in Example 23, except that the multilayer structure was resin layer X / inner layer / outer layer, and HDPE (Hi-Zex 6008B, manufactured by Prime Polymer Co., Ltd.) was used as the resin layer X. Molding was performed so that the thickness of the resin layer X at the center of the body was 100 μm.

[0100] The multilayer molded containers obtained in Examples 1 to 30, Comparative Examples 1 to 6, and Reference Example 1 were evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4.

[0101] [Moldability] The center of the body of the multi-layer molded container was cut into three 3 cm squares, and the thickness was measured with a vernier caliper. The difference between the maximum and minimum values ​​was taken as the film thickness unevenness and was evaluated according to the following criteria. ○: Film thickness unevenness is less than 50 μm △: Film thickness unevenness is 50 μm or more and less than 100 μm ×: Film thickness unevenness is 100 μm or more

[0102] [Color as seen from the exterior] A 3 cm square was cut out from the center of the body of the multilayer molded container and the color was measured with a color difference meter (SpectroColorMeterSE2000, manufactured by Nippon Denshoku Industries Co., Ltd.) to measure the L* value and YI value, and evaluated according to the following criteria. (L* value) ○: 90.0 or higher △: 80.0 or more and less than 90.0 ×: Less than 80.0 (YI value) ○: Less than 10.0 △: 10.0 or more and less than 15.0 ×: 15.0 or more

[0103] [Concealment] A 3 cm square was cut out from the center of the body of the multilayer molded container, and the total light transmittance was measured using a haze meter (BYK, Hazeguard Plus) and evaluated according to the following criteria. ○: Less than 1.0% △: 1.0% or more and less than 10.0% ×: 10.0% or more

[0104] [Drop strength] A multi-layer molded container was filled with water, sealed, and then dropped from a height of 1m twice, once so that the bottom part touched the concrete floor, and once so that the body part touched the concrete floor.The results were judged according to the following criteria. ○: No cracks or breaks, and no leakage of contents △: No leakage of contents observed, but cracks or breaks occurred ×: Cracks or breaks occurred, and leakage of contents was observed

[0105] [Recycled resin composition content] The content (mass%) of the recycled resin composition in the inner layer material was calculated according to the following formula and evaluated according to the following criteria: Content (mass%) of recycled resin composition=(mass (g) of recycled resin composition) / (mass (g) of recycled resin composition + mass (g) of resin 1 + mass (g) of pigment 1b)×100 ○: 50% by mass or more △: 10% by mass or more and less than 50% by mass ×: Less than 10% by mass

[0106] [Table 3]

[0107] [Table 4]

[0108] Example II <Preparation of inner layer material> The following raw materials for the inner layer were prepared: <Recycled resin composition derived from PET bottle caps> The crushed material of PET bottle caps purchased from a recycler was subjected to gravity-difference separation to remove foreign matter such as minute fragments of polyethylene terephthalate (PET), and was washed and dehydrated to obtain crushed recycled resin containing polyethylene (PE) and polypropylene (PP). The composition ratio of PE and PP contained in the recycled resin in the crushed material varies depending on the time and region in which the caps are collected, and the composition ratio can be identified from the peak intensity of PE and PP by infrared spectroscopy analysis in accordance with JIS K0117:2017. Then, for example, a resin sorter Aero Sorter III (manufactured by Daio Engineering Co., Ltd.) can be used to adjust the belt conveyor speed and recognition sensitivity to obtain crushed material with any composition ratio of PE and PP. The pigment contained in the crushed material can be identified by ash measurement in accordance with JIS K7250-1:2006, fluorescent X-ray analysis in accordance with JIS K0119-1:2008, and gas chromatography mass spectrometry (GC / MS method) in accordance with JIS K0123:2018. The pulverized materials separated according to composition ratio were melt-kneaded in a single screw extruder (manufactured by Nippon Placo Co., Ltd.) and fed into a pelletizer to obtain recycled resin compositions 1 to 21 in the form of pellets containing the recycled resin and pigment 1a. In the recycled resin compositions 1 to 21, the pigment 1a contained an inorganic pigment containing titanium oxide and a plurality of organic pigments selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet. In the recycled resin compositions 1 to 21, the pigment 1a contained at least one pigment selected from the group consisting of Pigment Yellow 181 and Pigment Red 254. In the recycled resin compositions 1 to 21, the content of the pigment 1a was 0.1 to 5 mass% based on the recycled resin composition. Table 5 shows the composition, MFR and density of the recycled resin compositions 1 to 21.

[0109] [Table 5]

[0110] <Resin 1 (A)> (A-1) HDPE (Hi-Zex 6203B, manufactured by Prime Polymer Co., Ltd., MFR: 0.35g / 10min) <Pigment 1b(B)> (B-1) Titanium oxide (Ishihara Sangyo Kaisha, Ltd., Typeque PF-711, average particle size: 0.25 μm, surface treatment: treatment with aluminum oxide, silicon dioxide, and siloxane) (B-4) Titanium oxide (Ishihara Sangyo Kaisha, Ltd. CR-80, average particle size: 0.25 μm, surface treatment: treatment with aluminum oxide and silicon dioxide) (B-5) Titanium oxide (Sakai Chemical Industry Co., Ltd. D-962, average particle size: 0.26 μm, surface treatment: treatment with aluminum oxide and siloxane)

[0111] [Inner layer composition 17] Resin 1 (A-1), Pigment 1b (B-1), and recycled resin composition 1 derived from PET bottle caps were fed into a twin-screw extruder (manufactured by Japan Steel Works) from separate supply ports so that the mixture was 47 mass% Resin 1 (A-1), 3 mass% Pigment 1b (B-1), and 50 mass% recycled resin composition derived from PET bottle caps. They were then melt-kneaded at 220°C to obtain inner layer composition 17, a pellet-shaped polyethylene-based inner layer material.

[0112] [Inner layer compositions 18-42] An inner layer composition was produced in the same manner as inner layer composition 17, except that the types and amounts (mass%) of resin 1 (A), pigment 1b (B), and recycled resin composition derived from PET bottle caps were changed as shown in Table 6.

[0113] A press sheet was prepared using the inner layer composition in the same manner as in Example I, and the color was measured.

[0114] [Table 6]

[0115] <Production and evaluation of multi-layer molded containers> Using the inner layer materials (inner layer compositions 17 to 42) and the outer layer materials produced in Example I (outer layer compositions 1 and 2), multilayer molded containers were produced.

[0116] [Examples 31 to 56 and Comparative Examples 7 to 13] A blow-molded container having a polyolefin-based multilayer structure was produced in the same manner as in Example I, except that the types and layer structures of the inner layer composition and outer layer composition were changed as shown in Tables 7 and 8, respectively.

[0117] The multilayer molded containers obtained in Examples 31 to 56 and Comparative Examples 7 to 13 were evaluated according to the same criteria as in Example I. The evaluation results are shown in Tables 7 and 8.

[0118] [Table 7]

[0119]

Table 8

Claims

1. The present invention has at least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, the inner layer being obtained by using a recycled resin composition, The recycled resin composition has a melt mass flow rate (MFR) of 0.1 to 10 g / 10 min and a density of 930 to 970 kg / m ３ and The multi-layer molded container, wherein the pigment 1 comprises aluminum oxide, silicon dioxide, and titanium oxide treated with siloxane.

2. The present invention has at least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, The recycled resin contains polyethylene and polypropylene, and in the recycled resin, the ratio of the mass (g) of polyethylene to the mass (g) of polypropylene is 70-95:5-30 (excluding 80-90:10-20).

3. The present invention has at least an inner layer containing a recycled resin obtained by using a PET bottle cap and a pigment 1, and an outer layer containing a white pigment 2 and a resin 2, The multilayer molded container includes at least one pigment selected from the group consisting of monoazo yellow, disazo yellow, monoazo orange, quinacridone red, diketopyrrolopyrrole red, phthalocyanine green, phthalocyanine blue, and quinacridone violet (excluding Pigment Yellow 181 and Pigment Red 254).

4. The multilayer molded container according to claim 1 or 3, wherein the recycled resin comprises at least one selected from the group consisting of polyethylene and polypropylene.

5. The multilayer molded container according to any one of claims 1 to 3, wherein the inner layer further contains a resin 1, and the resin 1 and the resin 2 contain a polyolefin.

6. The multilayer molded container according to any one of claims 1 to 3, wherein the inner layer further contains a resin 1, and the content of the resin 1 is 20 to 40 mass % based on the inner layer.

7. The multilayer molded container according to any one of claims 1 to 3, wherein the content of the white pigment 2 is 2 to 20 mass % based on the outer layer.

8. 4. The multilayer molded container according to claim 1, wherein the content of the white pigment 2 is 5 to 10 mass % based on the outer layer.

9. 4. The multilayer molded container according to claim 2, wherein the inner layer contains a white pigment 1, and the content of the white pigment 1 is 1 to 25 mass % based on the inner layer.

10. 4. The multilayer molded container according to claim 2, wherein the inner layer contains a white pigment 1, and the content of the white pigment 1 is 1 to 6 mass % based on the inner layer.

11. The multilayer molded container according to any one of claims 1 to 3, which at least partially has a multilayer structure having the inner layer and the outer layer, the inner layer having a thickness of 300 to 2,500 µm, and the outer layer having a thickness of 50 to 1,000 µm.

12. The multilayer molded container according to any one of claims 1 to 3, wherein the lightness (L* value) of at least a portion of the surface is 80.0 to 99.

0.

13. A method for producing the multilayer molded container according to any one of claims 1 to 3, comprising the steps of: A method for producing a multilayer molded container, comprising: molding an inner layer material containing a recycled resin composition including the recycled resin and a pigment 1a derived from a PET bottle cap, and an outer layer material containing a white pigment 2 and a resin 2, by a blow molding method or an extrusion molding method.

14. The method for producing a multilayer molded container according to claim 13, comprising molding an inner layer that satisfies the following: The lightness (L* value) of the inner layer is 45.0 to 90.

0.

15. The method for producing a multilayer molded container according to claim 13, comprising molding an outer layer that satisfies the following: The outer layer has a total light transmittance of 90.0% or less.

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