Method for producing recycled resin, method for producing pellet, and method for deodorizing raw film for recycling

Abstract

To provide a method for producing a recycled resin, a method for producing pellets, and a method for deodorizing a raw material film for recycling, which can reduce volatile components including fragrances from crushed packaging containers, i.e., reduce a content of volatile components contained in the resin before the resin contained in the packaging container is melted, kneaded, and molded, and can obtain recycled resin with a sufficiently reduced content of volatile components.SOLUTION: A method for producing a recycled resin, a method for producing pellets, and a method for deodorizing a raw material film for recycling have a following volatile component removal process. The volatile component removal process includes a process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing a heated gas through the chamber or by passing a gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing recycled resin, a method for producing pellets, and a method for deodorizing raw film for recycling. [Background technology]

[0002] Many shampoos and fabric softeners are characterized by their strong residual fragrance. Various volatile components such as fragrances remain in packaging containers that contain such products, and packaging containers made of laminated films with a polyolefin layer as the innermost layer are particularly prone to volatile components remaining in the polyolefin layer, and have traditionally been considered waste. For example, Patent Document 1 describes a technology for treating such waste, which aims to provide an apparatus for deodorizing the exhaust gas from an apparatus that heats and shrinks, melts, or dries waste such as rubber, plastic, or garbage, and is characterized in that after heating rubber, plastic, or garbage, the rubber, plastic, or garbage is mixed with water vapor or heated in the presence of water vapor, and then the heated steam flow is cooled to condense the water vapor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-162249 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for recycling the resin (plastic) contained in the packaging container. Through research by the present inventors, it has been found that when the resin contained in the packaging container used for a product containing a fragrance is used as a recycled resin, volatile components containing the fragrance may remain in the recycled resin, which hinders the use of the recycled resin. It has also been found that in the process of producing recycled resin from the packaging container (each process of melting, kneading, and molding), volatile components containing the fragrance diffuse into the production site, deteriorating the working environment when producing the recycled resin.

[0005] The present invention relates to a method for producing recycled resin that can reduce volatile components, including fragrances, from crushed packaging containers, i.e., can reduce the content of volatile components contained in the resin before melting, kneading and molding the resin contained in the packaging container, and can obtain recycled resin with a sufficiently reduced content of volatile components. The present invention also relates to a method for producing pellets that can reduce volatile components, including fragrances, from crushed packaging containers, and can obtain pellets with a sufficiently reduced content of volatile components. Furthermore, the present invention relates to a deodorizing method for recycled raw material film that can reduce volatile components, including fragrances, from crushed packaging containers. [Means for solving the problem]

[0006] The inventors have discovered that a raw recycling film having a specific average thickness or less, which contains volatile components and recycled resin and is obtained by, for example, crushing the above-mentioned packaging containers, can be floated and flowed in a chamber by circulating heated gas through the chamber, or by circulating gas through the chamber while heating it, thereby reducing the content of volatile components in the film, and that by melting, kneading, and molding the raw recycling film after the content of volatile components has been reduced, the diffusion of volatile components in the manufacturing site can be suppressed and recycled resin of the desired shape can be obtained. The present invention relates to the following [1] to [3]. [1] A method for producing recycled resin, comprising the following volatile component removal step: Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. [2] A method for producing pellets, comprising the steps of: a volatile component removing step; a melt-kneading step; and a molding step, in this order. Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. Melting and kneading process: A process in which the recycled resin obtained through the volatile component removal process is melted and kneaded. Molding process: The process of molding recycled resin that has gone through the melting and kneading process into pellets. [3] A method for deodorizing raw film for recycling, comprising the following volatile component removal process: Volatile component removal process: A process for removing or reducing the volatile components by floating and flowing the raw material film for recycling with an average thickness of 500 μm or less, which contains volatile components and recycling resin, in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating it. Effect of the Invention

[0007] According to the present invention, there is provided a method for producing recycled resin, which can reduce volatile components from crushed packaging containers, i.e., reduce the content of volatile components before melting, kneading, and molding the resin contained in the packaging container, and obtain recycled resin with a sufficiently reduced content of volatile components. Also, according to the present invention, there is provided a method for producing pellets, which can reduce volatile components including fragrances from crushed packaging containers, and obtain recycled resin with a sufficiently reduced content of volatile components. Furthermore, according to the present invention, there is provided a method for deodorizing raw material film for recycling, which can reduce volatile components from crushed packaging containers. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Manufacturing method of recycled resin] The method for producing recycled resin of the present invention includes the following volatile component removal step. Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. Hereinafter, the method for producing the recycled resin of the present invention may be simply referred to as the "production method of the present invention." Furthermore, the raw film for recycling having an average thickness of 500 μm or less used in the production method of the present invention may be simply referred to as the "raw film for recycling" or "film." According to the manufacturing method of the present invention, it is possible to reduce volatile components from crushed packaging containers, i.e., to reduce the content of volatile components contained in the resin before melting, kneading and molding the resin contained in the packaging containers, and to obtain recycled resin with a sufficiently reduced content of volatile components.

[0009] The reason why the present invention exhibits the above-mentioned effects is presumed to be as follows. In the manufacturing method of the present invention, the raw material for recycling is made into a film, so that the raw material for recycling is easily floated and flowed by the resistance of the gas flowing through the chamber. In addition, by flowing heated gas through the chamber, or by flowing gas while heating the chamber, the film is floated and flowed, and it is considered that the flexibility of the amorphous region of the resin for recycling contained in the raw material for recycling can be improved by thermal energy and kinetic energy. Therefore, even if the film containing volatile components has a multi-layer structure, gas molecules that collide with the film from the front, back, and side of the film easily penetrate into the film, and the volatile components are efficiently expelled from the film, which is considered to have reduced the content of volatile components in the film. It is possible to visually confirm that the raw material film for recycling is floating and flowing from the floor of the chamber.

[0010] The manufacturing method of the present invention may have a crushing step, a melt-kneading step, and a molding step in addition to the volatile component removal step, and preferably has the crushing step, the volatile component removal step, the melt-kneading step, and the molding step in this order. Hereinafter, the raw material film for recycling used in the manufacturing method of the present invention and the steps that the manufacturing method of the present invention has or can have will be described in that order.

[0011] [Recycling raw film] The raw material film for recycling, which has an average thickness of 500 μm or less and is used in the manufacturing method of the present invention, contains a volatile component and a resin for recycling. The raw material film for recycling can be obtained, for example, by subjecting the raw material for recycling to a crushing process described below, and the raw material film for recycling is preferably a crushed product of the raw material for recycling.

[0012] The average mass per piece of raw film for recycling is preferably 0.1 mg or more, more preferably 0.2 mg or more, and even more preferably 0.3 mg or more from the viewpoint of improving the work efficiency, and is preferably 6.0 mg or less, more preferably 5.0 mg or less, and even more preferably 4.0 mg or less from the viewpoint of efficiently reducing volatile components. Also, from the above two viewpoints, the average mass per piece of film is preferably 0.1 mg or more and 6.0 mg or less, more preferably 0.2 mg or more and 5.0 mg or less, and even more preferably 0.3 mg or more and 4.0 mg or less. The average mass per piece of film is determined by the method described in the Examples below. The average mass per film piece can be controlled, for example, by the crushing conditions in the crushing step described below and the screen opening size of the crusher used. In this specification, numerical ranges can be arbitrarily combined, and the numerical values ​​in the examples can be used as either the upper or lower limits.

[0013] The average thickness of the raw material film for recycling is preferably 50 μm or more, more preferably 80 μm or more, and even more preferably 100 μm or more from the viewpoint of having a protective function, and is 500 μm or less, preferably 400 μm or less, and more preferably 300 μm or less from the viewpoint of efficiently reducing volatile components. In addition, from the above two viewpoints, the average thickness of the film is preferably 50 μm or less and 500 μm or less, more preferably 80 μm or more and 400 μm or less, and even more preferably 100 μm or more and 300 μm or less. The average thickness of the film is determined by the method described in the examples below. Packaging containers made of a laminated film having the above average thickness are suitable as raw materials for recycling.

[0014] The average circle-equivalent diameter of the raw material film for recycling is preferably 500 μm or more, more preferably 1000 μm or more, and even more preferably 1500 μm or more from the viewpoint of economic efficiency and production efficiency, and is preferably 50000 μm or less, more preferably 10000 μm or less, and even more preferably 5000 μm or less from the viewpoint of promoting the removal of volatile components. In addition, the average circle-equivalent diameter of the film is preferably 500 μm or more and 50000 μm or less, more preferably 1000 μm or more and 10000 μm or less, and even more preferably 1500 μm or more and 5000 μm or less from the above two viewpoints. The average circle-equivalent diameter of the film is determined by the method described in the examples below. The average equivalent circular diameter of the film can be controlled, for example, by the crushing conditions in the crushing step described below and the screen opening size of the crusher used.

[0015] The ratio of the average equivalent circular diameter to the average thickness of the raw material film for recycling (average equivalent circular diameter (μm) / average thickness (μm)) is not particularly limited, but from the viewpoint of promoting the removal of volatile components, it is preferably 5 or more, more preferably 7 or more, and even more preferably 9 or more, and from the same viewpoint, it is preferably 100 or less, more preferably 50 or less, and even more preferably 30 or less. Moreover, from the above viewpoint, the ratio of the average equivalent circular diameter to the average thickness of the film is preferably 5 or more and 100 or less, more preferably 7 or more and 50 or less, and even more preferably 9 or more and 30 or less.

[0016] Examples of the raw material for recycling include packaging containers (e.g., pouch products) used for compositions containing volatile components including fragrances (e.g., shampoos, fabric softeners, laundry detergents, body soaps, household detergents, etc.). From the viewpoints of flexibility and strength, laminated films (multilayer films) are often used for such packaging containers, and many of them use polyolefins such as polyethylene for the inner layer and nylon or polyethylene terephthalate (PET) for the outer layer. Polyethylene has many amorphous regions, which allows fragrances to penetrate and leave a lingering scent. Packaging containers are usually used, but unused products may also be included in the raw material for recycling. The term "laminated film" refers to a film having a structure in which two or more layers of the same or different polymeric resins are laminated together. The laminated film may have a metal foil layer, such as an aluminum foil layer, in addition to the polymeric resin layer. As described above, the recycled raw material film used in the present invention is preferably crushed recycled raw material (crushed recycled raw material), and more preferably crushed used pouch products (crushed used pouch products).

[0017] <Recycled resin> The recycled resin contained in the raw material film for recycling used in the manufacturing method of the present invention is preferably, for example, one containing polyolefin and / or olefin copolymer. The polyolefin is at least one selected from polyethylene and polypropylene, and the olefin copolymer is an ethylene-vinyl alcohol copolymer. From the viewpoint of the recyclability of the recycled resin, the recycled resin preferably contains polyethylene. From the same viewpoint, the polyolefin may be polyethylene. As the polyethylene, commercially available ones such as high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), ultra-low density polyethylene (ULDPE), linear low density polyethylene (LLDPE), etc. are applicable to the present invention without any particular limitation. Other resins include the above-mentioned nylon and polyethylene terephthalate (PET).

[0018] From the viewpoint of recyclability, the content of the recycled resin in the raw film for recycling is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 99% by mass or more, and preferably 99.5% by mass or less. From the viewpoint of recyclability, the polyethylene content in the raw material film for recycling is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, and from the viewpoint of forming a laminated film containing polyethylene, it is preferably 90% by mass or less.

[0019] In addition to the volatile components and the recycled resin, the recycled raw material film may contain components other than the recycled resin, such as metals (e.g., aluminum), plasticizers, viscosity modifiers, UV absorbers, antioxidants, compatibilizers, gas barrier agents, and antistatic agents, to the extent that they do not interfere with recycling. From the viewpoint of recyclability, it is preferable that the amount of components other than the recycled resin is small. Specifically, the content of components other than the recycled resin in the recycled raw material is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less, and 0% by mass or more.

[0020] <Volatile components> The volatile components contained in the raw material film for recycling are not particularly limited, but preferably have a vapor pressure of 0.01 kPa or more and 106.66 kPa or less at 20° C. Also, preferably have a boiling point of 260° C. or less at normal pressure (1 atm). The volatile component may be one or more of a fragrance, a pharmaceutical, an agricultural chemical, a solvent, etc. Among them, in the production method of the present invention, it is preferable that the volatile component contains a fragrance, since the fragrance can be effectively reduced in the volatile component removal step.

[0021] Examples of the fragrance include fragrances blended in shampoos, fabric softeners, laundry detergents, body soaps, household detergents, etc. From the viewpoint of fragrance retention, the CLogP of the fragrance is preferably 0.1 or more, more preferably 1 or more, and even more preferably 3 or more, and from the viewpoint of reducing fragrance retention in the film, it is preferably 7 or less, more preferably 6 or less, and even more preferably 5 or less. From these viewpoints, the CLogP of the fragrance is preferably 0.1 or more and 7 or less, more preferably 1 or more and 6 or less, and even more preferably 3 or more and 5 or less.

[0022] Here, the LogP value is a coefficient indicating the affinity of a compound to water and 1-octanol. The 1-octanol / water partition coefficient P is the ratio of the equilibrium concentration of a compound in each solvent when a trace amount of a compound is dissolved as a solute in a solvent consisting of two liquid phases, 1-octanol and water, and reaches distribution equilibrium, and is generally expressed in the form of their logarithm LogP to the base 10. Nowadays, the value of "calculated LogP (CLogP)" calculated by a calculation program using the fragment value of the atomic group determined by the number of atoms constituting the compound molecule and the type of chemical bond is widely used. In this specification, the value of CLogP is calculated using the software EPI Suite (registered trademark; The Estimations Programs Interface for Windows version 4.11) jointly developed by the United States Environmental Protection Agency and Syracuse, Inc. The larger the CLogP value, the higher the fat solubility.

[0023] The preferred fragrances to be removed are acetyl cedrene (ClogP value: 5.0), aldehyde C-6 (ClogP value: 1.8), aldehyde C-10 (ClogP value: 3.8), aldehyde C-14 (ClogP value: 3.1), aldehyde C-16 (ClogP value: 3.0), allyl amyl glycolate (ClogP value: 2.3), α-Damascone (ClogP value: 4.3), amyl salicylate (ClogP value: 4.6), amber core ...14 (ClogP value: 3.1), aldehyde C-16 (ClogP value: 3.0), aldehyde C-14 (ClogP value: 3.1), aldehyde C-16 (ClogP value: 3.0), aldehyde C-14 (ClogP value: 3.1), aldehyde C-16 (ClogP value: 3.0), aldehyde C-14 (ClogP value: 3.1), aldehyde C-16 (ClogP value: 3.0), aldehyde C-14 (ClogP value: 3.1), aldehyde C-14 (ClogP value: 3.1), aldehyde C-14 (ClogP value: 3.1), aldehyde C-14 (ClogP value: 3.1), aldehyde C-14 (ClogP value: 3.1 core, ClogP value: 4.1), Ambroxan, ClogP value: 4.8, Amyl cinnamic aldehyde, ClogP value: 4.3, Anis aldehyde, ClogP value: 1.8, Benzyl acetate, ClogP value: 2.1, Benzyl alcohol, ClogP value: 1.1, Benzyl benzoate, ClogP value: 3.5, Benzyl salicylate, ClogP value: 4.3, β-Damascone, ClogP value: 4.4, β-Pinene, ClogP value: 4.4, Boisambrene forte forte, ClogP value: 5.5), Calone, ClogP value: 2.4, Canthoxal, ClogP value: 2.5, Cedryl methyl ether, ClogP value: 5.0, cis-3-Hexenol, ClogP value: 1.6, cis-3-Hexenyl acetate, ClogP value: 2.6, cis-3-Hexenyl benzoate, ClogP value: 4.1, cis-3-Hexenyl hexanoate, ClogP value: 4.6), cis-3-Hexenyl salicylate (ClogP value: 4.8), Citral (ClogP value: 3.5), Citronellol (ClogP value: 3.6), Citronellyl acetate (ClogP value: 4.6), Citronellyl nitrile (ClogP value: 3.6), Coumarin (ClogP value: 1.5), Cyclohexyl salicylate (ClogP value: 4.9), Cyclotene (ClogP value: 1.3), Damascenone (ClogP value: 4.2), δ-Damascone (ClogP value: 4.2), Dihydromyrcenol (Dihydromyrcenol) myrcenol, ClogP value: 3.6), diphenyl oxide, ClogP value: 4.1, dynascone, ClogP value: 4.5, ethyl acetate, ClogP value: 0.86, ethyl butyrate, ClogP value: 1.9, ethyl maltol, ClogP value: 0.30, ethyl 2-methylbutyrate, ClogP value: 2.3, ethyl vanillin, ClogP value: 1.6, ethylene brassylate brassylate, ClogP value: 4.7), Eugenol, ClogP value: 2.7, Farnesol, ClogP value: 5.8, Floralozone, ClogP value: 3.9, Floramat, ClogP value: 4.8, Floropal, ClogP value: 3.1, Fructone, ClogP value: 1.3, Fruitate, ClogP value: 3.6, γ-Terpinene, ClogP value: 4.8, Geraniol, ClogP value: 3.5, Geranyl acetate, ClogP value: 4.5), Geranyl propionate (ClogP value: 5.0), Helional (ClogP value: 2.5), Heliotropine (ClogP value: 1.8), Hexyl acetate (ClogP value: 2.8), Hexyl cinnamic aldehyde (ClogP value: 4.8), Hexyl salicylate (ClogP value: 5.1), Hydroxy citronellal (ClogP value: 2.1), Indoflor crystal (ClogP value: 1.8), Indol (ClogP value: 2.1), Ionone alpha (ClogP value: 4.3), Ionone beta (ClogP value: 4.3), Ionone β ... beta, ClogP value: 4.4), iso-Amyl acetate, ClogP value: 2.3, iso-Amyl salicylate, ClogP value: 4.5, Iso E super, ClogP value: 5.2, iso-Longiforanone, ClogP value: 3.8, Lactone C-10 gamma, ClogP value: 2.6, Lactone C-12 delta, ClogP value: 3.6, Lactone C-12 gamma, ClogP value: 3.6, Lemonile, ClogP value: 4.0, Ligustral SB SB, ClogP value: 4.8), Lilar, ClogP value: 3.3, Lilial, ClogP value: 4.4, Limonene, ClogP value: 4.8, Linalool, ClogP value: 3.4, Linalool oxide, ClogP value: 2.0, Linalyl acetate, ClogP value: 4.4, Manzanate, ClogP value: 2.8, Mayol, ClogP value: 3.5), 1-Menthol (ClogP value: 3.4), 1-Menthone (ClogP value: 2.9), Methyl dihydrojasmonate (ClogP value: 3.5), Methyl ionone-G (ClogP value: 4.8), Methyl jasmonate (ClogP value: 2.8), Musk C-14 (ClogP value: 4.2), Nectaryl (ClogP value: 5.1), Nerol (ClogP value: 3.5), Nerolidol (ClogP value: 5.7), o-t-Butylcyclohexyl acetate (ot-Butylcyclohexyl acetate, ClogP value: 4.4), Pamplefleur, ClogP value: 3.4, p-Cymene, ClogP value: 4.0, p-Menthane, ClogP value: 5.3, pt-Butylcyclohexyl acetate, ClogP value: 4.4, Phenoxy ethanol, ClogP value: 1.1, Phenyl ethyl alcohol, ClogP value: 1.6, Phenyl ethyl salicylate, ClogP value: 4.8, Phenyl propyl alcohol, ClogP value: 2.1, Poirenate, ClogP value: 4.0, Prenyl acetate acetate, ClogP value: 2.2), Raspberry ketone, ClogP value: 1.5, Rose oxide, ClogP value: 3.6, Styrallyl acetate, ClogP value: 2.5, Styrallyl alcohol, ClogP value: 1.5, Styrallyl propionate, ClogP value: 3.0, Terpineol, ClogP value: 3.3), Terpinolene 90 (ClogP value: 4.9), Terpinyl acetate (ClogP value: 4.3), Tetrahydro linalool (ClogP value: 3.6), Tetrahydro muguol (ClogP value: 3.6), Thymol (ClogP value: 3.5), Tricyclo decenyl acetate (ClogP value: 2.9), Tricyclo decenyl propionate (ClogP value: 3.5), At least one selected from the group consisting of propionate, ClogP value: 3.3), Triplar (ClogP value: 2.9), Undecavertol (ClogP value: 4.1), Vanillin (ClogP value: 1.1), Veloutone (ClogP value: 4.3), etc. is preferred, and at least one selected from Triplar, Flute, and Iso-E-Super is more preferred.

[0024] The raw material film for recycling used in the manufacturing method of the present invention is preferably a laminated film containing a polyethylene layer from the viewpoint of film flexibility, and from the viewpoint of using a polyethylene layer as an inner layer of the laminated film, it is preferable that a volatile component is contained in the polyethylene layer. Note that, in the form in which the volatile component is contained in the polyethylene layer, the volatile component may be contained not only in the polyethylene layer but also in layers other than the polyethylene layer.

[0025] [Crushing process] The raw material film for recycling used in the manufacturing method of the present invention is preferably obtained by subjecting the above-mentioned raw material for recycling to a crushing step. The crushing step is carried out by crushing the raw material for recycling with a crusher such as a single-shaft crusher, a two-shaft crusher, a three-shaft crusher, a cutter mill, a mesh mill, a cleaning crusher, etc. In this specification, the term "crushing" is used as a term including "pulverization". In order to remove contents and dirt adhering to the raw material for recycling, the raw material for recycling may be washed before or after the crushing process. Washing can be performed, for example, by rinsing the raw material for recycling with water or an aqueous surfactant solution. It is preferable to use a washing and crushing machine because washing and crushing can be performed simultaneously.

[0026] The crushing step may be performed once with a single crusher, or may be performed multiple times with the same or different crushers. By performing the crushing step multiple times, crushed material of smaller size can be easily obtained. For example, in the first crushing step, the screen opening of the crusher is preferably set to 10 mm or more, preferably 50 mm or less, and in the second crushing step, the screen opening of the crusher is preferably set to 1 mm or more, preferably 10 mm or less.

[0027] [Volatile component removal process] In the volatile component removal step of the manufacturing method of the present invention, the raw material film for recycling, which contains the volatile components and the resin for recycling, is suspended and flowed in a chamber by passing heated gas through the chamber, or by passing gas through the chamber while heating it, thereby reducing the content of volatile components in the film. In the volatile component removal step of the production method of the present invention, a heated gas may be circulated through the chamber while the inside of the chamber is heated.

[0028] The temperature of the heated gas and / or the temperature at which the inside of the chamber is heated in the volatile component removal step is preferably equal to or lower than the melting point of polyethylene. The temperature at which the inside of the chamber is heated here means the product temperature. The temperature of the heated gas and / or the temperature at which the inside of the chamber is heated is not particularly limited, but from the viewpoint of promoting the removal of volatile components, it is preferably 50°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher, and from the viewpoint of suppressing adhesion of molten polyethylene to the inside of the machine, it is preferably 160°C or lower, more preferably 140°C or lower, and even more preferably 130°C or lower. From the above two viewpoints, the temperature is preferably 50°C or higher and 160°C or lower, more preferably 70°C or higher and 140°C or lower, and even more preferably 80°C or higher and 130°C or lower.

[0029] The volatile component removal step may be carried out under reduced pressure, atmospheric pressure, or pressure. The internal pressure of the device in the volatile component removal step is not particularly limited, but from the viewpoint of promoting the removal of volatile components, it is preferably -1.0 kPaG or more, more preferably -0.5 kPaG or more, and even more preferably -0.1 kPaG or more, and from the same viewpoint, it is preferably 1.5 kPaG or less, more preferably 0.9 kPaG or less, and even more preferably 0.3 kPaG or less.

[0030] The volatile component removal step is carried out by passing a heated gas through the chamber or by passing a gas through the chamber while heating the chamber. By passing a heated gas through the chamber or a gas through the chamber, the raw film for recycling can be suspended and flowed, and as a result, the removal of the volatile components from the raw film for recycling can be promoted. That is, a recycled resin with a sufficiently reduced content of volatile components can be obtained from the resin for recycling contained in the film. The gas preferably contains air, more preferably air or a mixed gas of air and an inert gas such as nitrogen or carbon dioxide, and even more preferably air.

[0031] The flow rate of the gas (air volume) depends on the size of the chamber, but from the viewpoint of promoting the removal of volatile components, it is preferably 10 m 3 / h or more, preferably 30m3 / h or more, more preferably 50m 3 / h or more, and from the viewpoint of economy and production efficiency, it is preferably 1000 m 3 / h or less, preferably 500m 3 / h or less, more preferably 300m 3 From these viewpoints, the flow rate of the gas (air volume) is preferably 10 m 3 / h or more 1000m 3 / h or less, preferably 30m 3 / h or more 500m 3 / h or less, more preferably 50m 3 / h or more 300m 3 / h or less.

[0032] The flow rate (air volume) of the heated gas or gas relative to the average mass per piece of raw film for recycling (air volume of heated gas or gas / average mass per piece of raw film for recycling) is preferably 5 m from the viewpoint of promoting the removal of volatile components. 3 / (mg·h) or more, preferably 10m 3 / (mg·h) or more, more preferably 50m 3 / (mg·h) or more, and even more preferably 100m 3 / (mg·h) or more, and the upper limit is not particularly limited, but from the viewpoint of economy and equipment load, it is preferably 10,000 m 3 / (mg·h) or less, preferably 5000m 3 / (mg·h) or less, more preferably 4000m 3 From the above three viewpoints, the ratio of the volume of the heated gas or gas to the average mass per piece of raw film for recycling is preferably 5 m 3 / (mg·h) or more 10000m 3 / (mg·h) or less, preferably 10m 3 / (mg·h) or more 10000m 3 / (mg·h) or less, more preferably 50m 3 / (mg·h) or more 5000m 3 / (mg·h) or less, more preferably 100m 3 / (mg·h) or more 4000m3 / (mg·h) or less.

[0033] The ratio of the volume of the heated gas or gas (volume of the heated gas or gas / volume of the raw film for recycling) to the volume of the raw film for recycling in the chamber (volume of the raw film for recycling charged in the chamber for removing volatile components) is preferably 10 m or less from the viewpoint of promoting the removal of volatile components. 3 / (kg·h) or more, preferably 30m 3 / (kg·h) or more, more preferably 50m 3 / (kg·h) or more, and from the viewpoint of economy, it is preferably 500m 3 / (kg·h) or less, preferably 400m 3 / (kg·h) or less, more preferably 300m 3 From the above two viewpoints, the flow rate / charge amount of the heating gas or gas is preferably 10 m 3 / (kg·h) or more 500m 3 / (kg·h) or less, preferably 30m 3 / (kg·h) or more 400m 3 / (kg·h) or less, more preferably 50m 3 / (kg·h) or more 300m 3 / (kg·h) or less. The duration of the volatile component removal process (the time during which the gas is circulated) is preferably 10 minutes or more, more preferably 15 minutes or more, even more preferably 20 minutes or more, and is preferably 120 minutes or less, more preferably 90 minutes or less, even more preferably 60 minutes or less.

[0034] Examples of the type of equipment having a chamber that can be used in the volatile component removal step include dryers, such as fluidized bed dryers. Examples of the fluidized bed dryers include convection heat transfer type fluidized bed dryers, and among these, convection heat transfer type vibration fluidized bed dryers are preferred.

[0035] The floor area of ​​the chamber depends on the size of the equipment, but from the viewpoints of economy and manufacturing efficiency, it is preferably 0.003 m 2 More than 0.005m, preferably 0.005m 2More preferably, 0.007 m 2 From the viewpoint of workability, it is preferably 10 m or more. 2 Less than or equal to 5m, preferably 2 Less than 1m, more preferably 2 The following is the result.

[0036] The volume of the chamber (volume of the space) depends on the size of the device, but is, for example, 0.001 to 500 m 3 It is.

[0037] The gas velocity (apparent velocity) is not particularly limited, but from the viewpoint of promoting the removal of volatile components, it is preferably 0.1 m / sec or more, more preferably 0.2 m / sec or more, and even more preferably 0.3 m / sec or more, and from the viewpoint of reducing the load on the equipment, it is preferably 20 m / sec or less, more preferably 10 m / sec or less, and even more preferably 5 m / sec or less. The apparent velocity is the value obtained by dividing the air volume by the floor area (fluidized bed area) of the chamber.

[0038] Amount of raw film for recycling to be charged relative to the floor area of ​​the chamber (fluidized bed area) (amount of raw film for recycling charged / floor area of ​​the chamber (fluidized bed area)) (kg / m 2 ) is preferably 3 kg / m from the viewpoint of economy. 2 More preferably, 5kg / m 2 More preferably, 10 kg / m 2 From the viewpoint of facilitating the removal of volatile components, it is preferably 500 kg / m 2 Less than or equal to 400 kg / m 2 More preferably, 300 kg / m or less 2 From the above two viewpoints, the amount of raw film to be recycled / floor area of ​​the chamber (fluidized bed area) (kg / m 2 ) is preferably 3 kg / m 2 More than 500kg / m 2 Less than 5kg / m, more preferably 5kg / m 2 More than 400kg / m 2 More preferably, 10 kg / m or less 2 More than 300kg / m2 The following is the result.

[0039] [Melt-kneading process] From the viewpoint of the recyclability of the resin, the manufacturing method of the present invention preferably further includes a melt-kneading step. In the melt-kneading step, the recycled resin that has been subjected to the volatile component removal step is melt-kneaded. By melt-kneading the recycled resin, a recycled resin such as recycled polyolefin can be produced, for example, in the form of pellets. If the raw film for recycling contains components other than the resin for recycling (for example, metals), these can be removed, for example, by a laser filter during melt-kneading.

[0040] The melt-kneading step in the production method of the present invention may be any of a batch type, a semi-batch type, and a continuous type. The operating conditions and the equipment used in carrying out the melt-kneading step may be those known in the field of the present invention.

[0041] [Molding process] From the viewpoint of the recyclability of the resin, the production method of the present invention preferably further includes a molding step, in which recycled resin can be obtained in the form of pellets or film by a conventional method. The recycled resin may be formed into pellets, for example, by melt-kneading the resin, extruding a strand-like molten material from a die of a kneader, cooling the material with water, and then pelletizing the material with a cutter. The shape of the pellets may be granular or cylindrical, with a size of 3 to 5 mm.

[0042] [Recycled resin] The recycled resin produced by the production method of the present invention has a low content of volatile components and is suitable as a raw material for packaging containers from the viewpoint of recycling. The shape of the recycled resin is not particularly limited, and examples thereof include pellets and films, with pellets being preferred. The packaging container manufactured from the recycled resin manufactured by the manufacturing method of the present invention can be further used as a raw material for recycling after use. That is, the raw material for recycling can contain the recycled resin manufactured by the present invention from the viewpoint of recycling.

[0043] [Pellet manufacturing method] The method for producing pellets of the present invention includes the following steps of removing volatile components, melt-kneading, and molding, in this order. Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. Melting and kneading process: A process in which the recycled resin obtained through the volatile component removal process is melted and kneaded. Molding process: The process of molding recycled resin that has gone through the melting and kneading process into pellets. The pellet manufacturing method of the present invention may have a crushing step in addition to the volatile component removal step, the melt-kneading step, and the molding step, and preferably has the crushing step, the volatile component removal step, the melt-kneading step, and the molding step in that order. These crushing step, volatile component removal step, melt-kneading step, and molding step are the same as the crushing step, volatile component removal step, melt-kneading step, and molding step described in the recycled resin manufacturing method of the present invention, and therefore their description will be omitted.

[0044] [Method of deodorizing raw film for recycling] It is preferable to deodorize the raw material film for recycling from the viewpoint of reusing the resin for recycling, and a deodorization method having the volatile component removal step described below is preferable. The method for deodorizing raw film for recycling according to the present invention (hereinafter simply referred to as the "deodorizing method" of the present invention) has the following volatile component removing step. Volatile component removal process: A process for removing or reducing the volatile components by floating and flowing the raw material film for recycling with an average thickness of 500 μm or less, which contains volatile components and recycling resin, in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating it. The raw material film for recycling used in the deodorizing method of the present invention is similar to the raw material film for recycling used in the manufacturing method of the present invention, and the preferred numerical ranges are also similar, so a description thereof will be omitted. The deodorizing method of the present invention may have a crushing step in addition to the volatile component removal step, and preferably has the crushing step followed by the volatile component removal step in that order. These crushing step and volatile component removal steps are the same as the crushing step and volatile component removal step described in the manufacturing method of the present invention, and therefore will not be described here.

[0045] The present invention includes the following aspects. [1] A method for producing recycled resin, comprising the following volatile component removal step: Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. [2] The method for producing recycled resin according to [1], wherein the average thickness of the raw material film for recycling is preferably 50 μm or less and 500 μm or less, more preferably 80 μm or more and 400 μm or less, and even more preferably 100 μm or more and 300 μm or less. [3] The method for producing recycled resin according to [1] or [2], wherein the average mass per piece of raw film for recycling is preferably 0.1 mg or more and 6.0 mg or less, more preferably 0.2 mg or more and 5.0 mg or less, and even more preferably 0.3 mg or more and 4.0 mg or less. [4] The method according to any one of [1] to [3], wherein the average equivalent circle diameter of the raw film for recycling is preferably 500 μm or more and 50,000 μm or less, more preferably 1,000 μm or more and 10,000 μm or less, and even more preferably 1,500 μm or more and 5,000 μm or less. [5] The method for producing a recycled resin according to any one of [1] to [4], wherein the ratio of the average equivalent circular diameter to the average thickness of the raw film for recycling (average equivalent circular diameter (μm) / average thickness (μm)) is preferably 5 or more and 100 or less, more preferably 7 or more and 50 or less, and even more preferably 9 or more and 30 or less. [6] The ratio of the flow rate (air volume) of the heated gas or gas to the average mass per piece of raw film for recycling (air volume of heated gas or gas / average mass per piece of raw film for recycling) is preferably 5 m3 / (mg·h) or more, preferably 5m 3 / (mg·h) or more 10000m 3 / (mg·h) or less, more preferably 10m 3 / (mg·h) or more 10000m 3 / (mg·h) or less, more preferably 50m 3 / (mg·h) or more 5000m 3 / (mg·h) or less, more preferably 100m 3 / (mg·h) or more 4000m 3 The method for producing a recycled resin according to any one of [1] to [5], wherein the kinetic energy of the recycled resin is 0.1-0.2 wt %. [7] The ratio of the volume of the heated gas or gas to the volume of the raw film for recycling in the chamber (volume of the heated gas or gas / volume of the raw film) is preferably 10 m 3 / (kg·h) or more 500m 3 / (kg·h) or less, preferably 30m 3 / (kg·h) or more 400m 3 / (kg·h) or less, more preferably 50m 3 / (kg·h) or more 300m 3 The method for producing a recycled resin according to any one of [1] to [6], wherein the kinetic energy of the recycled resin is 0.1 wt. / (kg·h) or less. [8] The gas flow rate (air volume) is preferably 10 m 3 / h or more 1000m 3 / h or less, preferably 30m 3 / h or more 500m 3 / h or less, more preferably 50m 3 / h or more 300m 3 / h or less. [9] Amount of raw film to be recycled relative to the floor area of ​​the chamber (fluidized bed area) (amount of raw film to be recycled / floor area of ​​the chamber (fluidized bed area)) (kg / m 2 ), but preferably 3kg / m 2 More than 500kg / m 2 Less than 5kg / m, more preferably 5kg / m 2 More than 400kg / m 2 More preferably, 10 kg / m or less 2More than 300kg / m 2 The method for producing a recycled resin according to any one of [1] to [8] below.

[10] The method for producing a recycled resin according to any one of [1] to [9], wherein the gas preferably contains air.

[11] The method for producing a recycled resin according to any one of [1] to

[10] , wherein the gas is preferably air or a mixed gas of air and an inert gas such as nitrogen or carbon dioxide, more preferably air.

[12] The method for producing a recycled resin according to any one of [1] to

[11] , wherein the chamber is preferably a chamber of a dryer, more preferably a chamber of a fluidized bed dryer, even more preferably a chamber of a convection heat transfer type fluidized bed dryer, and even more preferably a chamber of a convection heat transfer type vibration fluidized bed dryer.

[13] The chamber floor area is preferably 0.003 m 2 More than 10m 2 Less than or equal to 0.005m, more preferably 2 More than 5m 2 Less than 0.007m, more preferably 0.007m 2 More than 1m 2 The method for producing a recycled resin according to any one of [1] to

[12] below.

[14] The method for producing recycled resin according to any one of [1] to

[13] , wherein the gas wind speed (apparent wind speed) is preferably 0.1 m / sec or more and 20 m / sec or less, more preferably 0.2 m / sec or more and 10 m / sec or less, and even more preferably 0.3 m / sec or more and 5 m / sec or less.

[15] The method for producing a recycled resin according to any one of [1] to

[14] , wherein the temperature of the heated gas and / or the temperature at which the inside of the chamber is heated in the volatile component removal step is preferably 50°C or higher and 160°C or lower, more preferably 70°C or higher and 140°C or lower, and even more preferably 80°C or higher and 130°C or lower.

[16] The method for producing recycled resin according to any one of [1] to

[15] , wherein the content of recycled resin in the raw film for recycling is preferably 85% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 99% by mass or more, and preferably 99.5% by mass or less.

[17] The method for producing a recycled resin according to any one of [1] to

[16] , wherein the polyethylene content in the raw material film for recycling is preferably 50% by mass or more and 90% by mass or less, more preferably 60% by mass or more and 90% by mass or less, and even more preferably 70% by mass or more and 90% by mass or less.

[18] The method for producing recycled resin according to any one of [1] to

[17] , wherein the raw material film for recycling is preferably a laminated film (multilayer film), more preferably a laminated film containing a polyethylene layer, and even more preferably a laminated film containing a polyethylene layer in which a volatile component is contained in the polyethylene layer.

[19] The method for producing recycled resin according to

[18] , wherein the laminated film preferably has an inner layer made of a polyolefin such as polyethylene and an outer layer made of nylon or polyethylene terephthalate (PET).

[20] The method for producing recycled resin according to

[18] , wherein the laminated film preferably uses a polyolefin such as polyethylene for the innermost layer and nylon or polyethylene terephthalate (PET) for the outermost layer.

[21] The method for producing recycled resin according to any one of [1] to

[20] , wherein the raw material film for recycling is preferably crushed raw material for recycling (crushed material of raw material for recycling), more preferably crushed used pouch products (crushed material of used pouch products).

[22] The method for producing recycled resin according to

[21] , wherein the raw material to be recycled is a packaging container (pouch product) used for a composition containing a volatile component, preferably including a fragrance (e.g., shampoo, fabric softener, laundry detergent, body soap, household detergent, etc.).

[23] The method for producing recycled resin according to any one of [1] to

[22] , wherein the volatile components include a fragrance.

[24] The method for producing recycled resin according to

[23] , wherein the CLogP of the fragrance is preferably 0.1 or more and 7 or less, more preferably 1 or more and 6 or less, and even more preferably 3 or more and 5 or less.

[25] A method for producing recycled resin according to

[24] , wherein the fragrance comprises at least one selected from the group consisting of Triplear, Fruitate and Iso-E-Super.

[26] Melt-kneading step: The method for producing a recycled resin according to any one of [1] to

[25] , further comprising a step of melt-kneading the recycled resin obtained through the volatile component removal step.

[27] A method for producing recycled resin according to

[26] , further comprising a molding step of molding the recycled resin that has been subjected to the melt kneading step into pellets.

[27] A method for producing pellets, comprising the steps of: a volatile component removing step; a melt-kneading step; and a molding step, in this order: Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is suspended and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. Melting and kneading process: A process in which the recycled resin obtained through the volatile component removal process is melted and kneaded. Molding process: The process of molding recycled resin that has gone through the melting and kneading process into pellets.

[28] A method for deodorizing raw film for recycling, comprising the following volatile component removal step: Volatile component removal process: A process for removing or reducing the volatile components by floating and flowing the raw material film for recycling with an average thickness of 500 μm or less, which contains volatile components and recycling resin, in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating it. EXAMPLES

[0046] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples in any way.

[0047] The raw material for recycling was collected packaging containers (recycling pouches) made of laminated film (innermost layer: polyethylene layer (70-90% by mass) / outermost layer: nylon layer or polyethylene terephthalate (PET) layer (5-25% by mass)) that contained fragrance-containing laundry detergents. The laminated film also contains a barrier layer, a printing layer, and an adhesive layer as other layers.

[0048] Example 1 [First crushing process] The residual liquid remaining in the packaging container was washed away using a washing and crushing machine (PFS-40, manufactured by Nippon Seam Co., Ltd.) and a centrifugal dehydrator (SW-408, manufactured by Nippon Seam Co., Ltd.) while being crushed and dehydrated into a film of several centimeters square. The operating conditions for the washing and crushing machine and the centrifugal dehydrator are as follows. Packaging container loading speed: 100kg / h Washing water flow rate: 1.4m 3 / h Number of cleaning water circulation times: 5 times (the water in the circulating water tank is drained after circulating through the device 5 times and replaced with clean water) Crusher blade rotation speed: 600r / min Rotational speed of the dehydrator rotor: 1730 r / min Crusher screen aperture Φ: 15mm Dehydrator screen opening Φ: 2mm

[0049] [Second crushing process] The film obtained in the first crushing step was further crushed into pieces of several millimeters square using a fine grinder (BO-480, manufactured by Horai Co., Ltd.) to obtain raw film for recycling. The operating conditions of the fine grinder were as follows: Raw material input speed: 100kg / h Rotating blade speed: 900r / min Screen aperture Φ: 3mm Blower speed: 41m / sec Blower air volume: 19.3m 3 / min

[0050] [Volatile component removal process] Small fluidized bed dryer (FD-LAB-1, chamber volume: 3 L, fluidized bed area: 0.008 m 2 The raw material film for recycling was dried using a small fluidized bed dryer (Powrex Corporation). 800 g of raw material film for recycling was placed in the chamber, and heated air was circulated from the bottom of the chamber into the chamber to float the raw material film for recycling and remove volatile components. The operating conditions of the small fluidized bed dryer are as shown in Table 1.

[0051] Sampling was performed 30 minutes after the start of the heated air flow, and the obtained samples were used for GC / FID (gas chromatography / flame ionization detector) analysis and sensory evaluation. The results are shown in Table 1. The GC / FID analysis and sensory evaluation will be described later.

[0052] Example 2 In the volatile component removal step of Example 1, a vibration fluidized bed dryer (B-QAD(C), vibration bed area 0.094 m) was used instead of the small fluidized bed dryer. 2 The procedure up to sampling was the same as in Example 1, except that a 1000g PET bottle (manufactured by Mitsubishi Materials Corporation) was used under the conditions shown in Table 1 and the following conditions, and the amount of raw film for recycling was changed from 800g to 1250g. Then, GC / FID analysis and sensory evaluation were performed. The results are shown in Table 1. Vibration floor punching diameter: 3mm Amplitude: 3mm Frequency: 50Hz

[0053] Example 3 In the "second crushing step" of Example 1, except that the screen opening Φ was changed from 3 mm to 6 mm, the same procedures as in Example 1 were carried out up to sampling, and GC / FID analysis and sensory evaluation were carried out. The results are shown in Table 1.

[0054] Comparative Example 1 The volatile component removal step of Example 1 was carried out with the following modifications. Instead of a small fluidized bed dryer, a high-speed mixer (FS VDGS-5JED type, manufactured by EarthTechnica Co., Ltd.) was used. Hot water set at 85°C was passed through the jacket of the high-speed mixer. 630 g of raw film for recycling obtained in the same manner as in the crushing process of Example 1 was charged into the high-speed mixer, and volatile components were removed while stirring. The operating conditions of the high-speed mixer are as follows. Agitator speed: 300 r / min Chopper speed: 150 r / min After drying the samples for 240 minutes in a high-speed mixer, GC / FID analysis and sensory evaluation were performed. The results are shown in Table 1.

[0055] Comparative Example 2 The raw film for recycling obtained in the same manner as in the crushing step of Example 1 was melt-kneaded (barrel temperature during kneading was 220°C, rotation speed was 250 r / min) in a twin-screw kneader (TEX-28V, screw diameter 28 mm, L / D = 42 mm, manufactured by Japan Steel Works, Ltd.) to obtain strands, which were cut with a cutter mill to prepare pellets having a thickness of 3.4 mm. The volatile components of the pellets were removed in the same manner as in Example 1, except that in the volatile component removal step of Example 1, pellets were used instead of the raw film for recycling and the conditions shown in Table 1 were adopted. In addition, the treatment was carried out at a higher air velocity than in Example 1 in order to remove volatile components while keeping the pellets in suspension. Sampling was performed 30 minutes after the start of the heated air flow, and the obtained samples were used for GC / FID (gas chromatography / flame ionization detector) analysis and sensory evaluation. The results are shown in Table 1.

[0056] [GC / FID analysis] Approximately 0.7 g of each sample was weighed out (referred to as a(g)), 10 mL of ethyl acetate was added, and extraction was performed at 50°C for 1 hour. The extract was filtered. GC analysis of the filtrate was performed under the following conditions, and the total area of ​​the chart after 3 minutes from the start of analysis (referred to as b) was obtained. Separately, in order to perform sensitivity correction, an ethyl acetate solution containing 20 ppm of tridecane was analyzed before the continuous analysis sequence of each sample was interrupted, and the peak area of ​​the tridecane chart that appeared after 3 minutes from the start of analysis (referred to as c) was obtained. The value of b / (a*c) was used as the conversion value of the volatile components of each sample.

[0057] The conditions for GC / FID analysis were as follows: GC device: 7890B (Agilent Technologies) Column: DB-1 HT Dimethylpolysiloxane (30 m × 0.25 mm × 0.25 μm) (Agilent Technologies) Carrier gas (N 2 ): 3.27mL / min Temperature conditions: 80℃→(10℃ / min)→300℃ hold 10min Inlet temperature: 250℃ Detector: FID Injection volume: 1μL

[0058] The conversion value obtained by this analysis method includes impurities (volatile components) contained in the virgin film (film before filling (film obtained from unused raw materials for recycling in the same manner as in the crushing process of the examples)). Therefore, GC / FID analysis was first performed on the virgin film to obtain the conversion value of the volatile components of the virgin film. The "equivalent value of volatile components contained in the raw material for recycling before being subjected to the volatile component removal process" in Table 1 is the equivalent value obtained by performing GC / FID analysis on the raw material for recycling (film or pellets) before being subjected to the volatile component removal process minus the equivalent value for virgin film. The "equivalent value of volatile components contained in the sample after the volatile component removal process" in Table 1 is the equivalent value obtained by performing GC / FID analysis on the sample (film or pellet) after the volatile component removal process minus the equivalent value for the virgin film. The reduction rate (%) of the volatile components shown in Table 1 was calculated from the following formula. Reduction rate of volatile components (%) = 100 - {converted value of volatile components (fragrances) in the sample after the volatile component removal process / converted value of volatile components (fragrances) contained in the recycled raw material before the volatile component removal process} x 100

[0059] [Sensory evaluation] The odor of the samples was evaluated by two expert panelists. Approximately 10g of the sample was placed in a sealable container and the evaluation was carried out from the viewpoint of odor intensity. The odor intensity was evaluated relatively on a five-point scale from 0 to 4 (the higher the number, the stronger the odor). The average value of the evaluation by the two panelists is shown in Table 1. 4: Strong odor 3: Easily detectable odors 2: A faint smell that you can tell what it is 1: A smell that can barely be detected 0: Odorless

[0060] [Table 1]

[0061] [Average mass per piece of recycled raw film or pellet] Fifty pieces of raw film or pellets for recycling were randomly selected, the masses of the 50 pieces were measured, and the number average of the masses of the 50 pieces was calculated to obtain the mass per piece. [Average circular equivalent diameter of raw film or pellets for recycling] 50 pieces of raw film or pellets for recycling were randomly selected. Using an image reader (Mac-view, manufactured by Mountec Co., Ltd.), the periphery of one piece of film or pellet was traced with a mouse to automatically measure the area, and the circle equivalent diameter was calculated from the area. The number average of the circle equivalent diameters of 50 pieces of film or 50 pellets was calculated and used as the average circle equivalent diameter. [Average thickness of raw film or pellets for recycling] The thicknesses of 50 randomly selected raw material films or pellets for recycling were measured with an electronic caliper, and the number average value was calculated to obtain the average thickness.

[0062] From the results of Examples 1 to 3, it is clear that the recycled resin obtained by the production method of the present invention has a sufficiently reduced content of volatile components contained in the raw material film for recycling. Comparing Examples 1 and 3, the content of volatile components is lower in Example 1. This is presumably because the larger (air volume / average mass per piece) makes it easier for the film to float and flow, making the amorphous regions of the recycled resin in the film more flexible and making it easier for the volatile components to be expelled. Also, the higher reduction rate of the content of volatile components in Example 2 is presumably due not only to the effect of vibration but also to the larger (air volume / average mass per piece). Furthermore, although the converted value of the volatile components contained in the sample after the volatile component removal process in Example 3 was high, the sensory evaluation was not so bad. This is presumably because the volatile components close to the film surface were removed. In Comparative Example 1, a conductive electrothermal high-speed mixer was used to produce recycled resin without passing gas through it, and the content of volatile components was not sufficiently reduced. In Comparative Example 2, the recycled resin was produced using pellets, not films, and even if the air volume was increased, the average mass per piece could not be made the desired value, and it is presumed that the floating fluidity was low and the content of volatile components was not sufficiently reduced. In addition, compared to Comparative Example 1, the converted value of the volatile components contained in the raw material for recycling before being subjected to the volatile component removal process in Comparative Example 2 is high, but the sensory evaluation is good, which is presumed to be due to the influence of the large average mass per piece and the small surface area.

Claims

1. A method for producing recycled resin, comprising the following volatile component removal step: Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is floated and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin.

2. The method for producing recycled resin according to claim 1, wherein the average equivalent circle diameter / average thickness of the raw material film for recycling is 5 or more and 100 or less.

3. The ratio of the volume of heated gas or gas to the average mass per piece of raw film for recycling is 5m ３ The method for producing recycled resin according to claim 1 or 2, wherein the carbon dioxide is 0.1 wt % or more.

4. The ratio of the volume of heated gas or gas to the volume of raw film for recycling in the chamber is 10 m ３ The method for producing recycled resin according to claim 1 or 2, wherein the reaction rate is 1000 kJ / (kg·h) or more.

5. The method for producing recycled resin according to claim 1 or 2, wherein the temperature of the heated gas and / or the temperature at which the inside of the chamber is heated is 50°C or higher and 160°C or lower.

6. 3. The method for producing recycled resin according to claim 1, wherein the raw material film for recycling is a laminated film including a polyethylene layer, and the volatile component is contained in the polyethylene layer.

7. The method for producing recycled resin according to claim 1 or 2, wherein the volatile components contain a fragrance.

8. 3. The method for producing recycled resin according to claim 1, wherein the recycled raw material film is a crushed material for recycled raw material.

9. The method for producing recycled resin according to claim 1 or 2, wherein the gas includes air.

10. A method for producing pellets, comprising the following steps in this order: a volatile component removal step; a melt-kneading step; and a molding step. Volatile component removal process: A process in which a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling is floated and flowed in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components and obtaining a recycled resin. Melting and kneading process: A process of melting and kneading the recycled resin obtained through the volatile component removal process. Molding process: The recycled resin that has been melted and kneaded is molded into pellets.

11. A method for deodorizing raw material film for recycling, comprising the following volatile component removal step: Volatile component removal process: A process of floating and flowing a raw material film for recycling with an average thickness of 500 μm or less containing volatile components and a resin for recycling in a chamber by passing heated gas through the chamber or by passing gas through the chamber while heating the chamber, thereby removing or reducing the volatile components.