Manufacturing method for molded products

Abstract

The present invention provides a method for manufacturing molded articles that allows for the recovery of recycled polyolefin resin from a laminate comprising a polyolefin film layer and a functional layer, thereby obtaining a molded article with excellent impact resistance. [Solution] A method for manufacturing a molded article, comprising recovering recycled polyolefin resin from a laminate comprising a polyolefin film layer and a functional layer, and manufacturing a molded article using the recycled polyolefin resin, the method comprising an immersion step of immersing the laminate in a desorption liquid containing alkali, A wet crushing step is performed in which the laminated body, after immersion, is wet crushed in the presence of water to obtain film pieces containing recycled polyolefin resin. The extruder using a screw equipped with a kneading block having one or more kneading discs is kneaded at a screw rotation speed of 300 rpm or more, and the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 A method for manufacturing a molded product, comprising a melt-kneading step of melt-kneading the mixture to the following state.

Description

[Technical Field]

[0001] This invention relates to a method for manufacturing molded articles. [Background technology]

[0002] Currently, the amount of waste plastic collected separately (recycling rate) worldwide is only 9% of the plastic manufactured. Of the 91% of waste plastic that is not collected separately, 12% is incinerated, and 79% ends up in landfills or is released into the environment (Non-Patent Literature 1). One reason for this persistently low recycling rate is the difficulty of implementing a separate collection system.

[0003] Specifically, in order to recycle plastics, it is necessary to separate and collect waste plastics, which are composed of various plastic materials such as polyethylene (PE) and polypropylene (PP), into individual materials. However, many plastic products, including laminated films, are made by bonding different plastic materials together, making it difficult to separate and collect them individually. Therefore, there is a strong need to develop a recycling system that can easily separate and collect waste plastics.

[0004] Furthermore, from a cost perspective, it is difficult to return recycled plastic products to the same quality as before recycling. Moreover, plastic products inherently degrade with each recycling cycle. Therefore, recycled plastic products inevitably suffer from a decline in quality.

[0005] In this regard, one reason why the quality of recycled plastic deteriorates is the presence of ink or pigment as an impurity in the plastic. In particular, many plastic products have printing applied to their surface, making it difficult to decolorize them during the recycling process. Furthermore, the plastic film that makes up plastic products generally has various functional layers in addition to the ink layer (printing layer), such as a hard coat layer, adhesive layer, and detachable primer layer. However, components derived from these functional layers can also cause unintended discoloration.

[0006] As a result, recycled plastic products are often colored. Such recycled plastic products not only have significantly lower commercial value due to the coloring, but their physical properties, such as elasticity, can also deteriorate due to impurities. Therefore, there is a need for methods to produce high-quality recycled plastic products.

[0007] For example, Patent Document 1 proposes a method for recycling multilayer film waste containing plastic and aluminum layers. Specifically, Patent Document 1 discloses a recycling method in which, for crushed multilayer film, the aluminum layer is dissolved in alkali, the remaining crushed material is separated by the difference in specific gravity, and then selectively heated and dissolved in an organic solvent, thereby separating the valuable components.

[0008] Furthermore, Patent Document 2 proposes a method for removing ink from printed plastic films. Specifically, Patent Document 2 discloses a method in which a printed plastic film is processed with a plunger, then crushed with a crusher, then the ink on the film is removed in a predetermined washing system, then the processed plastic film is rinsed, and then dried. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Science Advances 19 Jul 2017:Vol. 3, no. 7, e1700782

Patent Document

[0010]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0011] However, both the methods described in Patent Document 1 and Patent Document 2 have many and long steps and are complicated. Further, the method described in Patent Document 1 is a technique that only targets the removal of the aluminum layer from multilayer film waste, and the method described in Patent Document 2 is a technique that only targets the removal of ink from printed plastic films. Therefore, it is difficult to remove various functional layers by these methods.

[0012] Furthermore, Patent Document 1 and Patent Document 2 mainly focus only on the removal of layers formed on plastic films, and no consideration has been given at all to improving the mechanical properties such as impact resistance of recycled products (molded products). <s

[0013] Therefore, an object of the present disclosure is to provide a method for manufacturing a molded product capable of recovering a recycled polyolefin resin from a laminate including a polyolefin film layer and a functional layer and obtaining a molded product having excellent impact resistance.

Means for Solving the Problems

[0014] As a result of intensive studies, the inventors of the present invention have found that the above problems can be solved by using a laminate including a polyolefin film layer and a functional layer as a raw material and passing through a predetermined process, leading to the present invention.

[0015] [1] A method for manufacturing a molded article, comprising recovering recycled polyolefin resin from a laminate comprising a polyolefin film layer and a functional layer, and manufacturing a molded article using the recycled polyolefin resin, An immersion step in which the laminate is immersed in a desorption solution containing alkali, A wet crushing step is performed in which the laminated body, after immersion, is wet crushed in the presence of water to obtain film pieces containing recycled polyolefin resin. The extruder using a screw equipped with a kneading block having one or more kneading discs is kneaded at a screw rotation speed of 300 rpm or more, and the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 A method for manufacturing a molded product, comprising a melt-kneading step of melt-kneading the mixture to the following state.

[0016] [2] The method according to [1], wherein the kneading block is made up of two or more kneading discs connected together, and the angle between the long axes of adjacent connected kneading discs is greater than 0° and less than 90°.

[0017] [3] The method for producing a molded article according to either [1] or [2], wherein the functional layer is a cured product of a reactive adhesive containing a polyol compound and a polyisocyanate compound.

[0018] [4] A method for manufacturing a molded article according to any one of [1] to [3], wherein the wet crushing is carried out by shaking or beating.

[0019] [5] A method for manufacturing a molded article according to any one of [1] to [4], further comprising a molding step of molding the molten mixture obtained in the molten mixture step to obtain a molded article. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a method for manufacturing a molded article that allows for the recovery of recycled polyolefin resin from a laminate comprising a polyolefin film layer and a functional layer, thereby obtaining a molded article with excellent impact resistance. [Brief explanation of the drawing]

[0021] [Figure 1] Figure 1 is a schematic diagram showing an example of the extrusion apparatus of this embodiment. [Figure 2] Figure 2 is an enlarged view showing an example of a cylinder 3 with the screw 1 shown in Figure 1. [Figure 3] Figure 3 is a schematic diagram showing an example of a screw. [Figure 4] Figure 4 is a schematic diagram showing another example of a screw. [Figure 5] The upper part of Figure 5 shows a front view (left) and a side view (right) of an example of a forward-feeding full-flight screw block 11. The lower part of Figure 5 shows a front view (left) and a side view (right) of an example of a reverse-feeding full-flight screw block 14. [Figure 6] Figure 6 shows a front view (left) and a side view (right) of an example of the kneading block of this embodiment. [Figure 7] Figure 7 shows a front view (left) and a side view (right) of another example of the kneading block of this embodiment. [Figure 8] Figure 8 shows a front view (left) and a side view (right) of another example of the kneading block of this embodiment. [Modes for carrying out the invention]

[0022] The embodiments of the present invention (hereinafter referred to as "these embodiments") will be described in detail below, but this disclosure is not limited to the following description and can be implemented in various modifications within the scope of its gist. [Method for manufacturing molded products] The method for manufacturing molded articles of this embodiment (hereinafter sometimes referred to as "the method of this embodiment") is a method for manufacturing molded articles that recovers recycled plastic from a laminate comprising a polyolefin film layer and a functional layer, and manufactures a molded article using the recycled polyolefin resin. The method of this embodiment comprises an immersion step of immersing the laminate in a desorption solution containing alkali, a wet crushing step of obtaining film pieces containing recycled polyolefin resin by wet crushing the immersed laminate in the presence of water, and kneading the film pieces or a composition containing the film pieces using an extruder with a screw equipped with a kneading block having one or more kneading discs at a screw rotation speed of 300 rpm or more, wherein the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less and the dispersion volume of the domain phase derived from the functional layer is 20 μm 3 This includes a melting and kneading step in which the mixture is melted and kneaded to the following state. Furthermore, if necessary, the process may include a take-up step in which the molten mixture extruded in the molten mixing step is taken up as strands, and a molding step in which the strands are used to form the material.

[0023] As a result of diligent research by the inventors, it has been found that by using a laminate comprising a polyolefin film layer and a functional layer as the object to be processed, as in the method of this embodiment, and by performing a predetermined immersion step and a wet crushing step, a recycled polyolefin resin suitable as a molded article material can be obtained. Furthermore, by performing a predetermined melt-kneading step using such recycled polyolefin resin, the functional layer contained in the laminate can be refined. As a result, it has been found that a molded article with excellent impact resistance can be obtained because the refined functional layer is dispersed as a domain phase having a predetermined dispersion diameter and dispersion volume. More specifically, this improvement in impact resistance can be achieved by appropriately performing the predetermined immersion step and the predetermined wet crushing step, as well as the predetermined melt-kneading step, to form a so-called sea-island structure in which the recycled polyolefin resin is the matrix phase (sea phase) and the refined functional layer is the domain phase (island phase). Furthermore, since the refined functional layer can be dispersed as domain phases (island phases) in the sea phase of the recycled polyolefin resin as particles having an appropriate dispersion volume and dispersion diameter, it is possible to reduce the unevenness of the interface area with the sea phase, such as aggregation of island phases or large island phases. As a result, even when the compatibility between the sea phase and the island phase is low, it is possible to reduce localized fracture at the interface between the island phase and the sea phase due to impact, and thus the impact resistance of the molded product as a whole is presumed to be improved.

[0024] Furthermore, "domain phase derived from the functional layer" refers to a phase that contains one or more of the materials that make up the functional layer in the laminate that is the raw material, and which is a component that is poorly compatible with or undergoes phase separation with the polyolefin resin (including recycled polyolefin resin).

[0025] The method for manufacturing a molded article according to this embodiment essentially comprises an immersion step, a wet crushing step, and a melt-kneading step, and may further comprise one or more steps selected from the group consisting of a pretreatment step, a washing step, a rinsing step, and a molding step, as needed. A preferred method in this embodiment involves subjecting a laminate comprising a polyolefin film layer and a functional layer, which are raw materials, to a pretreatment step, followed by an immersion step, a washing step, a wet crushing step, a rinsing step, a melt-kneading step, a take-up step, and a molding step in that order. This makes it possible to obtain a molded product with superior impact resistance.

[0026] Furthermore, in the method of this embodiment, the functional layer is not limited to a printed layer or the like. Even a laminate in which various functional layers, described later, are provided on a polyolefin film layer can be used as a raw material (or object to be processed) in this manufacturing method, and a desired molded product can be manufactured.

[0027] (Laminate as the target of processing) In the method of this embodiment, a laminate comprising at least a polyolefin film layer and a functional layer is used as the object to be processed. The laminate used in this embodiment is, for example, a non-roll form plastic film. Alternatively, the laminate can be cut from a roll form plastic film.

[0028] The laminate used in this embodiment is not particularly limited as long as it is a material having a layer of polyolefin resin, and may, for example, be a waste plastic film (discarded plastic film). The laminate is not particularly limited and can be a plastic film that is generally distributed as packaging material for food or household goods, or a film with various types of discarded plastic substrates. The laminate may be used alone or in combination of two or more types.

[0029] Furthermore, the laminate used in this embodiment may have only one polyolefin resin layer, or it may have two or more. When the laminate has two or more polyolefin resin layers, the types of resins constituting these polyolefin resin layers may be the same, or they may be different from one another.

[0030] Furthermore, the laminate used in this embodiment may have only one functional layer or two or more functional layers. If the laminate has two or more functional layers, these functional layers may be identical or different. The laminate used in this embodiment may be, for example, a laminate having a functional layer on its outermost surface. The laminate used in this embodiment may be, for example, a laminate in which a functional layer is provided between a plurality of polyolefin resin layers.

[0031] <Polyolefin film layer> As described above, the laminate used in this embodiment comprises a polyolefin film layer. A polyolefin film layer refers to a layered member containing polyolefin resin as the main constituent resin. For example, it refers to a layered member in which 50% or more by mass of the total amount of the polyolefin film layer is composed of polyolefin resin.

[0032] Specifically, the polyolefin film layer mentioned above is a polyolefin film layer composed of a polyolefin resin. Examples of such polyolefin resins include polyethylene such as low-density polyethylene, high-density polyethylene, and linear low-density polyethylene; polypropylene such as OPP (biaxially oriented polypropylene) and CPP (unoriented polypropylene); propylene-ethylene copolymer; ethylene-butene-propylene copolymer; and the like. A preferred example of the polyolefin film layer is, in particular, that it contains polypropylene such as OPP or CPP as the main constituent resin, from the viewpoint of the versatility or ease of recovery of the final molded product. That is, the polyolefin film layer is more preferably a low-density polyethylene film, a high-density polyethylene film, a linear low-density polyethylene film, or a polypropylene film, and is particularly preferably a polypropylene film.

[0033] The average thickness of the polyolefin film layer is not particularly limited, but is preferably, for example, 5 μm or more, or 10 μm or more, and also preferably, for example, 500 μm or less, 200 μm or less, 100 μm or less, or 50 μm or less. These upper and lower limits can be any combination. In this specification, the average thickness refers to the average thickness at any five locations.

[0034] In the laminate used in this embodiment, it is preferable that a part or all of the polyolefin film layer is in direct contact with the functional layer. As will be described later, multiple functional layers (multiple different functional layers or multiple identical functional layers) may be laminated. In this case, it is preferable that one of the multiple functional layers, or a part or all of one of them, is in direct contact with the polyolefin film layer. Furthermore, it is preferable that the polyolefin film layer is located on the outermost surface of the laminate.

[0035] <Functional Layer> As described above, the laminate used in this embodiment includes a functional layer. The functional layer is not particularly limited and includes, for example, a printing layer (also called an ink layer), a detachable primer layer, an adhesive layer, a functional coating layer, etc. The laminate may have one of these functional layers alone, or two or more in combination. In this embodiment, the functional layer is preferably one or more layers selected from the group consisting of a printing layer, a detachable primer layer, an adhesive layer, and a functional coating layer. The average thickness of the functional layer in this embodiment (or the average thickness of each functional layer if there are multiple functional layers) is not particularly limited, but is preferably 0.1 μm or more and 100 μm or less, more preferably 0.1 μm or more and 10 μm or less, and even more preferably 1 μm or more and 5 μm or less. These upper and lower limits can be combined arbitrarily. The total average thickness of the functional layers in this embodiment is preferably 0.05% μm to 300%, more preferably 0.1% to 100%, and even more preferably 2.5% to 20%, relative to the total average thickness (100%) of the laminate. These upper and lower limits can be combined in any way.

[0036] The functional layer (printing layer, detachable primer layer, adhesive layer, functional coating layer, etc.) may contain a resin having an acidic group or a low molecular weight compound having an acidic group. In addition, the functional layer may contain a resin that does not have an acidic group, in addition to the resin having an acidic group or a low molecular weight compound having an acidic group.

[0037] Examples of resins having the above-mentioned acidic group include rosin-modified maleic acid resin, rosin-modified fumaric acid resin, and polymer resins obtained by copolymerizing polymerizable monomers having the acidic group. Examples of polymerizable monomers having the acidic group include polymerizable monomers having carboxyl groups such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, cinnamic acid or their acid anhydrides, polymerizable monomers having sulfonic acid groups such as sulfonated styrene, and polymerizable monomers having sulfonamide groups such as vinylbenzenesulfonamide. Specific examples of the above-mentioned polymer resin include (meth)acrylic resin, styrene-(meth)acrylic resin, styrene-(anhydride)maleic acid resin, and terpene-(anhydride)maleic acid resin.

[0038] Examples of low molecular weight compounds having the above-mentioned acidic group include saturated fatty acids, unsaturated fatty acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, carboxylic acid derivatives, and acid anhydrides.

[0039] Examples of saturated fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, and stearic acid. Examples of unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and sorbic acid. Examples of hydroxy acids include lactic acid, malic acid, and citric acid. Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, melitic acid, and cinnamic acid. Examples of dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, and maleic acid. Examples of tricarboxylic acids include aconitic acid. Examples of oxocarboxylic acids include pyruvate and oxaloacetate. Examples of carboxylic acid derivatives include amino acids and nitrocarboxylic acids. Examples of acid anhydrides include trimellitic anhydride and pyromellitic anhydride.

[0040] -Print layer- The laminate used in this embodiment may include a printed layer as a functional layer. The printed layer is typically a layer containing ink. The printed layer may be a layer on which any picture, pattern, character, and symbol is displayed for the purpose of decoration or aesthetic appeal, or for displaying contents, expiration date, and manufacturer or seller information. Alternatively, the printed layer may be a layer on which no picture, pattern, character, or symbol is displayed (i.e., a layer without gaps, a solid layer).

[0041] The above-mentioned printed layer is formed by printing using, for example, a gravure printing press, a flexographic printing press, an offset printing press, or an inkjet printing press. That is, the ink used to form the printed layer may be gravure printing ink (gravure ink), flexographic printing ink (flexographic ink), offset printing ink (offset ink), or inkjet printing ink (inkjet ink).

[0042] The above-mentioned ink may be, for example, an organic solvent-based printing ink, a water-based ink, or an active energy ray-curing ink. The ink contained in the printing layer may be a single type or a combination of two or more types. Furthermore, the printing layer may be a single-color printing layer or a multi-color printing layer.

[0043] In the laminate of this embodiment, the position of the printed layer is appropriately selected according to the intended use, and may be located on the outermost surface of the laminate, or it may be sandwiched between other layers. Furthermore, part or all of the printed layer may be in direct contact with other functional layers other than the printed layer.

[0044] -Desorbable primer layer- The laminate used in this embodiment may include a detachable primer layer as a functional layer. In this case, recyclability can be improved, and the quality of recycled plastic can be improved. The detachable primer layer can be easily detached from other layers by treatment with an alkali-containing solution (detachment solution). Therefore, when the laminate of this embodiment has a detachable primer layer as a functional layer, it becomes easier to detach it from other layers during the immersion process. The thickness of the detachable primer layer is preferably 0.1 μm to 100 μm, more preferably 0.1 μm to 10 μm, and even more preferably 1 μm to 5 μm. These upper and lower limits can be combined in any way.

[0045] In the laminate of this embodiment, the deleasible primer layer is preferably in contact with the polyolefin film layer. Furthermore, in the laminate, the deleasible primer layer is preferably bonded to and sandwiched between the polyolefin film layer and other functional layers (e.g., a printing layer, an adhesive layer, a functional coating layer, etc.). In this case, recyclability can be further improved, and the quality of the recycled polyolefin resin can be further improved. The above-mentioned detachable primer layer is typically formed by applying a detachable primer layer composition (solution) to the surface to be formed and drying it.

[0046] Furthermore, the desorbable primer layer (and composition for the desorbable primer layer) of this embodiment may contain a resin that forms a film at room temperature. Examples of resins that form a film at room temperature include polyester; polyvinyl chloride; copolymers of vinyl chloride and other unsaturated double-bond-containing monomers; homopolymers of (meth)acrylic acid esters; copolymers of (meth)acrylic acid esters and other unsaturated double-bond-containing monomers; polystyrene; copolymers of styrene monomer and other unsaturated double-bond-containing monomers; ketone-formaldehyde condensates or their hydrogenated products; polyfunctional epoxy resins; polyvinyl acetal; urethane resins; and the like. Examples of polyfunctional epoxy resins include bisphenol A novolac type epoxy resin, bisphenol F novolac type epoxy resin, bisphenol S novolac type epoxy resin, biphenyl type epoxy resin, and naphthalene type epoxy resin. These resins that form a film at room temperature may be used individually or in combination of two or more types.

[0047] In one embodiment, the detachable primer layer preferably contains a urethane resin. Such a detachable primer layer can be formed, for example, using a detachable primer layer composition containing a urethane resin and an aqueous medium. Urethane resin is a general term for polymer compounds having urethane bonds (-NHCOO-). The above urethane resin can be obtained by reacting a polyol compound (for example, an aromatic polyester polyol), a polyisocyanate compound, and, if necessary, a chain extender. The desorbable primer layer of this embodiment is preferably a cured product of a desorbable primer layer composition containing a polyol compound (for example, an aromatic polyester polyol) and a polyisocyanate compound.

[0048] Examples of polyol compounds used as reaction raw materials for the above-mentioned urethane resin include known polyester polyols, known polyether polyols, and aromatic polyester polyols. For example, the contents of the various polyols described in International Publication No. 2021 / 025093 and International Publication No. 2020 / 003778 can be used as the polyester polyols, polyether polyols, and aromatic polyester polyols. Alternatively, polyol compounds used in the adhesive layer or adhesive layer composition described later may be used.

[0049] Examples of polyisocyanate compounds used as reaction raw materials for the above-mentioned urethane resin include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are commonly used in the production of general polyurethane resins. The organic diisocyanate compound in question is defined by the following general formula (i): [ka] (In the above general formula (i), L 1 and L 2 Each of these independently represents a single bond or an alkylene group with 1 to 5 carbon atoms, M 1 (This represents a divalent organic group.) It is preferable that it be represented as follows: In the above general formula (i), L 1 It is preferable that the bond is a single bond or an alkylene group having 1 to 3 carbon atoms. In the above general formula (i), L 2 It is preferable that the bond is a single bond or an alkylene group having 1 to 3 carbon atoms. In the above general formula (i), the divalent organic group preferably has 1 to 20 carbon atoms, more preferably has 2 to 18 carbon atoms, and even more preferably has 3 to 17 carbon atoms. "Organic group" means a group having 1 or more carbon atoms, and is preferably a hydrocarbon group having 1 to 20 carbon atoms. The above divalent organic group is preferably an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 1 to 20 carbon atoms, an alkylene oxy group having 1 to 20 carbon atoms, or an arylene group having 6 to 18 carbon atoms. Furthermore, one or more non-adjacent -CH2- in the alkylene group, alkenylene group, alkylene oxy group, or arylene group may be substituted with -O-, -COO-, or -OCO-. In the above general formula (i), M 1 Preferably, the alkylene group has 3 to 12 carbon atoms, excluding the number of carbon atoms of the substituent.

[0050] Specific examples of polyisocyanate compounds in this embodiment include, for example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyli isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylenediisocyanate, 1,4-phenylenediisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropyl diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and lysine diisocyanate. Preferred diisocyanates include annetes, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanate-methyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and dimer diisocyanates obtained by converting the carboxyl groups of dimer acids to isocyanate groups. These diisocyanate compounds can be used individually or in combination of two or more. Among the examples of the above organic diisocyanate compounds (a1), hexamethylene diisocyanate, xylylene diisocyanate, and isophorone diisocyanate are preferred, and isophorone diisocyanate is particularly preferred.

[0051] In the reaction raw materials for the urethane resin of this embodiment, the proportion of the polyisocyanate compound is preferably 1 to 40% by mass, more preferably 5 to 30% by mass, and even more preferably 5 to 25% by mass, relative to the total amount of reaction raw materials (100% by mass).

[0052] In another embodiment, the detachable primer layer preferably contains polyvinyl alcohol. Such a detachable primer layer can be formed, for example, using a detachable primer layer composition containing polyvinyl alcohol and an aqueous medium.

[0053] The polyvinyl alcohol mentioned above is a colorless powder obtained by saponifying polyvinyl acetate. Furthermore, polyvinyl alcohol is a water-soluble thermoplastic resin and is a raw material for the synthetic fiber vinylon.

[0054] Examples of the aqueous medium include water and organic solvents that are miscible with water. The aqueous medium may be used alone or in combination of two or more. Examples of organic solvents that are miscible with water include alcohols such as methanol, ethanol, n-propanol, and isopropanol; ketones such as acetone and methyl ethyl ketone; polyalkylene glycols such as ethylene glycol, diethylene glycol, and propylene glycol; alkyl ethers of polyalkylene glycols; and N-methyl-2-pyrrolidone.

[0055] -Adhesive layer- The laminate used in this embodiment may include an adhesive layer as a functional layer. The adhesive constituting the adhesive layer can be any adhesive that can be used in a general-purpose lamination method. Examples of such general-purpose lamination methods include dry lamination and wet lamination using solvent-type laminating adhesives, and non-solvent lamination using solvent-free laminating adhesives.

[0056] Examples of the adhesives mentioned above include vinyl resins, (meth)acrylic resins, polyamide resins, polyester resins, polyether resins, polyurethane resins, epoxy resins, and rubber resins. Among these, polyurethane resins are preferred. Such adhesives may be one-component or two-component, and may be curing or non-curing. The adhesive layer is typically formed by applying an adhesive layer composition (solution) to the surface to be formed and allowing it to dry.

[0057] In this embodiment, the functional layer, for example, the adhesive layer, is preferably a cured product of an adhesive layer composition containing a polyol compound and a polyisocyanate compound. The polyol compound used in the aforementioned adhesive layer composition is not particularly limited as long as it is known as a polyol compound for reactive adhesives. Specific examples of polyol compounds include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, methylpentanediol, dimethylbutanediol, butylethylpropanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1 Examples of polymer polyols include glycols such as 4-cyclohexanedimethanol and triethylene glycol; trifunctional or tetrafunctional aliphatic alcohols such as glycerin, trimethylolpropane, and pentaerythritol; bisphenols such as bisphenol A, bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F; dimergols; and polymer polyols selected from polyester polyols, polyether polyols, polyurethane polyols, polyether ester polyols, polyester (polyurethane) polyols, polyether (polyurethane) polyols, polyesteramide polyols, acrylic polyols, polycarbonate polyols, polyhydroxyl alkanes, castor oil, or mixtures thereof.

[0058] In addition, as the polyisocyanate compound used in the composition for the adhesive layer, any polyisocyanate compound known as a polyisocyanate compound for reactive adhesives can be used without particular limitation. Specific examples of the polyisocyanate compound include, for example, polyisocyanates having an aromatic structure in the molecular structure such as tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate, xylylene diisocyanate, etc.; compounds obtained by modifying a part of the isocyanate groups (NCO groups) of these polyisocyanates with carbodiimide; polyisocyanates having an alicyclic structure in the molecular structure such as isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,3-(isocyanatomethyl)cyclohexane, etc.; linear aliphatic polyisocyanates such as 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, etc., and compounds obtained by modifying a part of the NCO groups of these polyisocyanates with carbodiimide; isocyanurate forms of the various polyisocyanates described above; allophanate forms derived from the various polyisocyanates described above; biuret forms derived from the various polyisocyanates described above; adduct forms obtained by modifying the various polyisocyanates with trimethylolpropane; polyisocyanates which are reaction products of the various polyisocyanates and a polyol component described below, and the like. Incidentally, the content of the reactive adhesive described in, for example, International Publication No. 2020 / 066652 may be incorporated into the composition for the adhesive layer. Further, the polyisocyanate compound used in the composition for the detachable primer layer described above may be used.

[0059] The adhesive layer is preferably sandwiched between other layers (a polyolefin film layer; other functional layers other than the adhesive layer (the printing layer); etc.) in the laminate. The average coating amount of the adhesive layer is adjusted as appropriate. In the case of a solvent-based adhesive, as an example, the solid content is 1 g / m 2 or more and 10 g / m 2 or less, preferably 2 g / m2 More than 5g / m 2 Adjust the following: For solvent-free adhesives, the adhesive application amount is, for example, 1 g / m². 2 More than 5g / m 2 Preferably 1 g / m 2 More than 3g / m 2 The following applies. These upper and lower limits can be combined in any way.

[0060] - Functional coating layer - The laminate used in this embodiment may include a functional coating layer as a functional layer. The functional coating layer may be provided on the laminate for purposes such as hard coating, silicone-based release, IR cut, waterproofing and moisture resistance, antibacterial properties, UV cut, heat dissipation, photocatalysis, weather resistance, anti-fogging, fingerprint resistance, self-healing, and water and oil repellency. Specifically, examples of functional coating layers include hard coating layers, adhesive layers, release layers, decorative layers, light-shielding layers, ultraviolet shielding layers, antistatic layers, refractive index adjusting layers, and oligomer encapsulation layers. These functional coating layers may be colorless or colored.

[0061] The above-mentioned functional coating layer can be formed by applying various coating agents, such as hard coating agents, self-healing coating agents, anti-fingerprint and anti-fouling coating agents, anti-fogging coating agents, silicone-based release agents, non-silicone-based release agents, waterproof and moisture-proof coating agents, water-repellent and oil-repellent coating agents, photocatalytic coating agents, weather-resistant coating agents, IR-cut coating agents, and other surface modifiers, optical adhesives, polyimide varnishes, liquid crystal alignment film materials, electromagnetic wave shielding coating agents, fine wiring pastes, antistatic coating agents, high refractive index coating agents, and optical lens coating agents, to the surface to be formed. The average thickness of these functional coating layers is preferably 0.1 μm to 100 μm, more preferably 0.1 μm to 10 μm, and even more preferably 1 μm to 5 μm.

[0062] The above-mentioned functional coating layer may be a layer formed of a metallic material (metal layer). The metal layer may be a metal foil, or a metal vapor-deposited layer formed by the deposition of a metal or metal oxide. Examples of metal foils include foils of metals with excellent malleability, such as gold, silver, copper, zinc, iron, lead, tin and their alloys, steel, stainless steel, and aluminum. Examples of metal vapor-deposited layers include layers containing aluminum, aluminum oxide, silica, zinc oxide, etc.

[0063] The above-mentioned functional coating layer may be a single layer or a multilayer consisting of multiple identical or different functional coating layers. For example, the functional coating layer may be a multilayer consisting of a layer formed using the above-mentioned various coating agents and the above-mentioned metal vapor deposition layer. In this case, the layer formed using the above-mentioned various coating agents may be provided in the laminate via a metal vapor deposition layer in contact with the plastic substrate layer.

[0064] Next, each step constituting the method of this embodiment will be described. (Pre-treatment process) The method of this embodiment is not particularly limited, and a pretreatment step of crushing the laminate described above may be performed prior to the immersion step if necessary. Performing such a pretreatment step increases the processing efficiency of each subsequent step, and allows for more efficient recovery of recycled plastic from the laminate. More specifically, by performing such a pretreatment step, the laminate can be recovered as film pieces containing raw polyolefin resin in subsequent steps. The method of crushing the laminate is not particularly limited, and known methods can be used. Furthermore, the crushing of the laminate can be performed in an air atmosphere where no liquid such as a solvent is present, and in that case, a known dry crusher can be suitably used.

[0065] When performing a pretreatment step, the laminate can be crushed so that the dimensions in the short side direction and the long side direction are preferably 1 mm to 30 mm, more preferably 1 mm to 20 mm.

[0066] (Soaking process) In the manufacturing method of the molded product of this embodiment, the laminate described above is immersed in a desorption solution containing alkali as an immersion step. This allows the laminate to swell.

[0067] <Separated liquid> Examples of alkalis in the above-mentioned desorbed liquid include sodium hydroxide, lithium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, and ammonium. Among these, sodium hydroxide or potassium hydroxide is preferred as the alkali, and sodium hydroxide is more preferred.

[0068] The alkali concentration in the above-mentioned eluent is preferably 0.1% to 10% by mass, and more preferably 0.1% to 5% by mass, as a percentage of the total volume of the eluent. The pH of the above-mentioned eluent is preferably 10 or higher, preferably 11 or higher, and more preferably 12 or higher. The above-mentioned eluent may contain water. In this case, operational stability and environmental stability can be improved.

[0069] The above-mentioned eluent may contain a surfactant. The surfactant is not particularly limited, and known surfactants can be used. Examples of surfactants include anionic surfactants, nonionic surfactants, amphoteric surfactants, and cationic surfactants. The surfactant may be used alone or in combination of two or more types. When a surfactant is used, the concentration of the surfactant in the eluent is preferably 0.01% to 5% by mass, and more preferably 2% by mass or less, as a percentage of the total eluent.

[0070] The above-mentioned eluent may contain an appropriate amount of organic solvent. Examples of organic solvents include water-soluble alcohols and water-soluble solvents with a flash point of 21°C or higher. Examples of water-soluble alcohols include methanol, ethanol, 1-propyl alcohol, and 2-propyl alcohol. Examples of water-soluble solvents with a flash point of 21°C or higher include diethylene glycol methyl ether, diethylene glycol butyl ether, propylene glycol propyl ether, and 3-methoxy-3-methyl-1-butanol. By using the above-mentioned water-soluble organic solvent, ions such as hydroxide ions generated from the alkali in the eluent become less susceptible to hydration, thus increasing the nucleophilicity of these ions. As a result, the recovery of recycled polyolefin resin can be performed more efficiently.

[0071] <Stirring> In the immersion process of this embodiment, stirring is preferable, although not essential. In this case, the laminate can be swelled more efficiently. The stirring device and stirring conditions are not particularly limited, and known ones can be appropriately adopted. For example, immersion with stirring can be performed using a container equipped with a motor-driven stirring blade, a container equipped with means for generating ultrasonic waves, or a container equipped with a shaking means.

[0072] <Soaking temperature> In the immersion step of this embodiment, the immersion temperature (temperature of the desorbing liquid during immersion) at which the laminate is immersed in the desorbing liquid is not particularly limited as long as the liquid state of the desorbing liquid is maintained, but can be, for example, 15 to 90°C. However, a higher immersion temperature is preferable because it can shorten the immersion time. Specifically, the preferred immersion temperature varies depending on the composition of the desorbing liquid, but is 40°C or higher, 50°C or higher, or 60°C or higher.

[0073] <Soaking time> In the immersion process of this embodiment, the immersion time for immersing the laminate in the desorption liquid is preferably a time for the laminate to swell sufficiently, and specifically, it is preferably 30 minutes or more. Furthermore, from the viewpoint of processing efficiency, the upper limit of the immersion time is preferably 48 hours or less. Also, if the immersion temperature is room temperature, the laminate can swell sufficiently with an immersion time of 24 hours. Furthermore, if the immersion temperature is, for example, 40°C, the laminate can swell sufficiently with an immersion time of 16 hours. Furthermore, if the immersion temperature is, for example, 75°C, the laminate can swell sufficiently with an immersion time of 120 minutes. Moreover, the immersion time can be appropriately adjusted depending on the combination of whether or not stirring is performed and the immersion temperature as described above.

[0074] <Washing process> The laminate after the immersion process in this embodiment may have alkali-containing desorbing liquid adhering to it. Therefore, in the method of this embodiment, although not particularly limited, a washing step may be performed after the immersion process to wash the laminate in order to remove the adhering alkali. Water can usually be used for washing such a laminate.

[0075] (Wet crushing process) The manufacturing method of the molded product of this embodiment includes a wet crushing step, in which the laminate obtained in the immersion step is wet crushed in the presence of water to obtain a film piece containing recycled polyolefin resin. When a polyolefin film layer or laminate is crushed by a wet crushing process, the polyolefin film layer can be easily peeled off completely as a single layer in a subsequent process. In the wet crushing process, it is sufficient that the polyolefin film layer or laminate is crushed; the crushed polyolefin film layer or laminate may have at least a part of it, such as the edges, partially peeled off, or each layer may be completely peeled off, or each layer may not be peeled off at all. Furthermore, if the film piece containing recycled polyolefin resin obtained in the wet crushing process is not a flat body but has a shape with protruding parts relative to the surface, is folded, or is well-crushed, it can be easily peeled off completely as a single layer in a subsequent process. As an example of a preferred embodiment of the film piece containing recycled polyolefin resin obtained in the wet crushing process, a well-crushed state is defined as a film piece with a surface roughness of 0.7 μm or more. By making the surface roughness of the film piece, which is the crushed material obtained by the wet crushing process described above, 0.7 μm or more, the laminate can be separated into single layers, and not only the functional layer (especially the printed layer) provided on the surface of the laminate but also the functional layer (especially the printed layer) provided between the laminates can be removed. Therefore, the recovered crushed material is suitable as a raw material for producing high-quality recycled plastic. The surface roughness of the film piece is preferably 0.7 μm or more, more preferably 0.8 μm or more, and even more preferably 0.9 μm or more. On the other hand, there is no particular upper limit, and it can be adjusted as appropriate according to the conditions of the wet crushing equipment, and for example, it may be preferably 10 μm. The surface roughness of the film sample is determined by measuring the surface roughness Sa of a 500 μm × 600 μm area using a white light interference microscope manufactured by Ryoka Systems Co., Ltd. Sa represents the entire surface area, unlike Ra which is a value determined from a cross-section, thus providing a wider evaluation range and allowing for the assessment of overall surface roughness.

[0076] As a means for wet crushing the immersed laminate in the presence of water, a wet crushing method that crushes in water or a washing solution is preferred, and a wet crusher that can crush and pump simultaneously can be used. This allows for efficient crushing of the laminate or polyolefin film layer, and also allows for the separation of the laminated laminate into individual layers. The preferred wet crusher is one that can simultaneously perform at least three, more preferably four or more, of the five actions of crushing, dispersing, mixing, pumping, and shaking solid material in a liquid. Specifically, it is preferable to have a mechanism that crushes solid material in a liquid using shear force and / or frictional force, and a crusher that can crush and pump a polyolefin film layer. Examples of such wet crushers include one or more selected from the group consisting of a continuous shaking device, a wet crushing pump, a colloid mill, a grinder, and a beating machine, with a continuous shaking device being particularly preferred.

[0077] <Continuous Shaking Device> In this embodiment, the wet crushing step is preferably a step in which the laminate after the immersion step is shaken in the presence of water using a continuous shaking device equipped with dispersed media in a container. Such a shaking step makes it easier to obtain only the recycled polyolefin resin derived from the polyolefin film layer of the laminate.

[0078] The above shaking can be performed using a continuous shaking device equipped with a dispersion medium such as a rod or beads. Examples of such continuous shaking devices equipped with a dispersion medium include paint shakers, ball mills, vibratory mills, attritors, and bead mills.

[0079] When using rods as the dispersion medium, the material of the rods can be steel, zirconia, alumina, stainless steel, etc. The diameter of the rods is preferably 12 mm or more, preferably 35 mm or less, more preferably 24 mm or less, and even more preferably 19 mm or less. A rod diameter of 12 mm or more makes handling easier and helps suppress problems such as twisting within the device. Furthermore, a rod diameter of 35 mm or less ensures sufficient contact with the laminate within a predetermined time, thereby suppressing a decrease in productivity.

[0080] When beads are used as the dispersion medium, the materials of the beads include steel, zirconia, alumina, stainless steel, and glass. The diameter (sphere diameter) of the beads is preferably 0.5 mm or more, more preferably 5 mm or more, even more preferably 10 mm or more, preferably 35 mm or less, more preferably 30 mm or less, and even more preferably 25 mm or less. If the diameter of the beads is 0.5 mm or more, they are easy to handle and it is possible to suppress the difficulty in recovering the beads due to them getting mixed with the laminate (or film piece) to be processed. Also, if the diameter of the beads is 35 mm or less, it is possible to ensure a sufficient number of contacts with the laminate within a predetermined time and suppress a decrease in productivity.

[0081] The continuous shaking device used in the shaking process preferably has a dispersion media packing rate of 10 vol% to 90 vol%, more preferably 30 vol% to 80 vol%. If the dispersion media packing rate is less than 10 vol%, it may not be possible to specifically change the crystalline structure and higher-order structure of the polyolefin film layer, and the impact resistance of the final molded product may not be improved. Furthermore, if the dispersion media packing rate exceeds 90 vol%, it may not be possible to provide sufficient energy to the laminate, and the desired recycled polyolefin resin may not be obtained. From a similar viewpoint, the dispersion media packing rate in the container is preferably 35 vol% or more, preferably 70 vol% or less, and more preferably 60 vol% or less.

[0082] In a shaking process using a continuous shaking device, the residence time of the material to be processed can be, for example, 10 seconds or more, 20 seconds or more, or 30 seconds or more, and can also be 10 minutes or less, 5 minutes or less, or 2 minutes or less. In this case, specific changes in the crystalline structure and higher-order structure of the polyolefin film layer can be brought about more effectively while maintaining high productivity and processing efficiency.

[0083] In the shaking process using a continuous shaking device, the processing speed of the laminate can be, for example, 100 g / min or more, 200 g / min or more, or 300 g / min or more, and can also be 2000 g / min or less, 1500 g / min or less, or 1000 g / min or less. In this case, while maintaining high productivity and processing efficiency, it is possible to more effectively bring about specific changes in the crystalline structure and higher-order structure of the polyolefin film layer.

[0084] In a shaking process using a continuous shaking device, the ratio of laminate to water can be, for example, 50g or more, 100g or more, or 120g or more of laminate per liter of water, or 400g or less, 300g or less, or 200g or less. In this case, specific changes in the crystalline structure and higher-order structure of the polyolefin film layer can be brought about more effectively while maintaining high productivity and processing efficiency.

[0085] Furthermore, the film fragments containing recycled polyolefin resin generated during the shaking process can be recovered prior to the subsequent melt-mixing process. The recovery method is not particularly limited and can be any conventional method, such as specific gravity separation in a liquid such as water. In addition, it is preferable to thoroughly remove moisture from the recovered film fragments containing recycled polyolefin resin prior to the subsequent melt-mixing process.

[0086] <Wet crushing pump> The above-mentioned wet crushing pump preferably has a mechanism that crushes the solid material by a fixed blade and a rotating blade while pumping the solid material in a liquid, and a more preferred mechanism is one in which the material is crushed in three stages by a combination of four parts: a cutting blade, a crushing impeller, a shroud ring, and a grid. The polyolefin film layer or laminate is crushed in three stages by a wet crushing pump. The polyolefin film layer or laminate is roughly cut by the cutting edge of a fixed blade and the edge of the inlet of the rotating crushing impeller, then agitated and pumped by an axial-flow type crushing impeller, and some of the polyolefin film layer or laminate is cut by the blade portion of the shroud ring of the fixed blade. The polyolefin film layer or laminate that has passed through the crushing impeller is further crushed and agitated between the grid and the grid, then pressurized by a pressure impeller through the grid and pumped to the next process. While there are no particular limitations on the pumping speed, considering the peeling and separation efficiency when peeling the ink layer and separating the laminate into individual layers, 0.03 m 3 A rate of at least / min is preferred. The upper limit of the pumping speed is not particularly limited, and the standard operating speed of the device, for example, 1.4m / min, is acceptable. 3 Even at a rate of / min, it is sufficient to remove the ink and separate the laminate into single layers. The grid shape is not particularly limited. Since the grid diameter affects the size of the laminate after crushing, the grid diameter is preferably 0.1 to 50 mm, and more preferably 1 to 20 mm, considering the crushing efficiency and the size of the laminate after crushing. Specific examples of wet crushing pumps that can be used in this embodiment include the KD series from Husqvarna Zenoah, the San Cutter series from Nikuni, the Disintegrator series from Furukawa Industrial Systems, the Incrusher series and Refiners from Aikawa Iron Works, the Scatter from Sanwa Hydrotech, and the Trigonal from Nippon Coke Co., Ltd.

[0087] <Colloid Mill> The colloidal mill described above is a machine used to reduce particle size in dispersions where particles are suspended in a liquid. A colloidal mill consists of a rotor and a stator, with the rotor rotating at high speed relative to the stationary stator. The high level of shear generated by this high-speed rotation is used to reduce the particle size in the liquid. The crushing section of the colloid mill consists of a combination of a toothed, frustoconical rotor and a stator, both of which are tapered, narrowing as they approach the discharge port. The laminate is crushed by repeatedly applying strong shear, compression, and impact in a ring-shaped gap that narrows as it approaches the discharge port. The specific colloid mills that can be used in this embodiment are not particularly limited as long as they are dispersers that are generally called colloid mills, but examples include IKA's Colloid Mill MK series, Iwaki's WCM series, Mountec's PUC Colloid Mill series, and Eurotech's Cavitron.

[0088] <Grinding machine> The above-mentioned grinder preferably has a mechanism that rotates an upper and lower set of millstones in a liquid while crushing solid material placed between the millstones by shearing and friction, and is preferably capable of grinding solid material to a fine powder while water is flowing through it. The size of the crushed material can be adjusted by adjusting the spacing between the upper and lower millstones, but it is usually finely ground to 500 μm or less, preferably 300 μm or less, and more preferably 200 μm or less. By reducing the size of the crushed material in this way, each layer of the laminate is separated into a single layer, and the storage space required for the crushed material can be reduced, making inventory management easier. In addition, when producing film pieces containing recycled polyolefin resin from the crushed material, the material can be fed into the kneader without passing through a compressor or the like, thus simplifying the process. On the other hand, the lower limit of the size of the crushed material is preferably 10 μm or more, preferably 30 μm or more, and more preferably 50 μm or more, in order to facilitate recovery. There are no particular restrictions on rotational speed or water flow speed. Examples of grinding machines that can be used in this embodiment include the Super Mascolloider manufactured by Masuko Sangyo Co., Ltd.

[0089] <beating machine> The above-described beating machine is generally a device for grinding fibrous materials, etc., equipped with a rotating blade or preferably a rotating disc and optionally a fixed blade or preferably a fixed disc. Preferably, it consists of one or two metal discs with radial ridges, these discs are in close contact with each other, and a gap is formed between them. In a double-disc type beating machine, one or both discs can rotate, usually in opposite directions. Normally, the beating machine is operated at atmospheric pressure. In this embodiment, suitable beating machines include disc refiners, conical refiners, high-pressure homogenizers, millstone grinders, or beaters. Among these, disc refiners and conical refiners are preferred from the viewpoint of being able to finely refinish the material most efficiently.

[0090] When wet crushing a laminate in the presence of water using the wet crusher described above, crushing may be carried out using water as the solvent, or a washing solution containing an inorganic base, a known surfactant or other washing or peeling component, or other components in water. Specifically, examples of the inorganic base include sodium hydroxide and potassium hydroxide. These inorganic bases are contained in a concentration of 0.1 to 10% by weight of the total amount of the washing solution, but a concentration of 0.1% to 5% by weight is more preferred. The pH is preferably 10 or higher. Furthermore, various washing agents and surfactants described in International Publication No. 2024 / 053245 and International Publication No. 2021 / 230033 may be incorporated herein by reference as the washing solution and the surfactant.

[0091] (Rinsing process) On the surface of the film pieces containing recycled polyolefin resin obtained in the wet crushing process described above, substances other than those intended for recovery, such as functional layers, may remain and adhere. Therefore, it is preferable that the method for manufacturing molded articles in this embodiment further includes a rinsing step in which the film pieces are washed with a rinsing solution after the wet crushing process (and before the melt-kneading process).

[0092] Washing with rinsing solution may be accompanied by agitation. The agitation device and agitation conditions are not particularly limited, and known devices can be appropriately adopted. For example, immersion with agitation can be performed using a container equipped with a motor-driven agitator, a container equipped with means for generating ultrasonic waves, or a container equipped with a shaking means.

[0093] Washing with a rinsing solution can be performed using a device equipped with a dispersion medium such as rods or beads. Such a device equipped with a dispersion medium is the same as that described in the shaking process.

[0094] The rinsing solution preferably contains a water-soluble solvent. Examples of water-soluble solvents include water-soluble alcohols and water-soluble solvents with a flash point of 21°C or higher. Examples of water-soluble alcohols include methanol, ethanol, 1-propyl alcohol, and 2-propyl alcohol. Examples of water-soluble solvents with a flash point of 21°C or higher include diethylene glycol methyl ether, diethylene glycol butyl ether, propylene glycol propyl ether, and 3-methoxy-3-methyl-1-butanol.

[0095] From the viewpoint of improving cleaning efficiency, the proportion of water-soluble solvent in the rinsing solution is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0096] (Melting and mixing process) The manufacturing method for the molded product of this embodiment includes a melt-kneading step. In the melt-kneading step of this embodiment, a film piece containing recycled polyolefin resin obtained in the wet crushing step, or a composition containing the recycled polyolefin resin, is kneaded at a rotation speed of 300 rpm or more using an extruder with a screw equipped with a kneading block having one or more kneading discs, so that the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 This is the process of melting and kneading the mixture to the following state. This has the effect of improving the impact resistance of the entire molded product.

[0097] In this embodiment, the conditions for reducing the dispersion diameter of the domain phase derived from the functional layer to 10 μm or less mainly consist of the following four conditions: (i) the feeding rate of the raw material film pieces obtained by the wet crushing process (= the speed at which the crushed plastic film is fed into the extruder), (ii) the cylinder temperature (or barrel temperature), (iii) the screw rotation speed, and (iv) the screw formation (referring to the configuration of the screw, such as the presence or absence of a kneading block). By controlling these four conditions (i) to (iv) within a specific range, it tends to become easier to control the dispersion diameter of the domain phase derived from the functional layer to 10 μm or less. Among these, (iv) the screw formation is considered to be particularly important. A preferred specific example of (iv) the screw formation is that by using a kneading block having one or more kneading discs as the configuration of the screw, it becomes easier to control the dispersion diameter to 10 μm or less. In this embodiment, the dispersion volume of the domain phase derived from the functional layer is 20 μm 3The conditions for achieving the following are mainly the following four: (i) the rate at which the raw material film pieces obtained by the wet crushing process are fed into the extruder (= the rate at which the crushed plastic film is fed into the extruder), (ii) the cylinder temperature (or barrel temperature), (iii) the screw rotation speed, and (iv) the screw formation (referring to the configuration of the screw, such as the presence or absence of a kneading block). By controlling these four conditions (i) to (iv) within a specific range, the dispersion volume of the domain phase derived from the functional layer can be reduced to 20 μm³. 3 The following tendencies make control easier. Among them, (iv) screw formation is considered to have a particularly significant effect. Specifically, by using a screw with a kneading block having one or more kneading disks, the dispersion volume of the domain phase derived from the functional layer can be reduced to 20 μm 3 The following will make it easier to control.

[0098] In the melt-mixing process of this embodiment, the preferred input rate of the film pieces, which are the raw material obtained by the wet crushing process (i) described above, is preferably 5 to 100 kg / h, more preferably 5 to 50 kg / h, and even more preferably 5 to 30 kg / h. The faster the input rate of the film pieces, the higher the resin pressure inside the extruder, and a better mixing state can be formed. In the manufacturing method of the molded article of this embodiment, only a laminate comprising a polyolefin film layer and a functional layer may be used as the raw material component, or one or more selected from the group consisting of virgin material, modified resin, and additives may be mixed with the laminate. For example, in the former case, only a laminate comprising a polyolefin film layer and a functional layer is subjected to a melt-kneading step to a film piece containing recycled polyolefin resin obtained by an immersion step and a wet crushing step. On the other hand, in the latter case, at least in the melt-kneading step of this embodiment, it is sufficient that the film piece containing recycled polyolefin resin and one or more selected from the group consisting of virgin material, modified resin, and additives are melt-kneaded. Therefore, one or more selected from the group consisting of virgin material, modified resin, and additives can be appropriately blended from before the immersion step until the completion of the melt-kneading step. Therefore, when mixing the film pieces with unused resin (so-called virgin material), or when mixing the film pieces with modified resin or additives, it is preferable to increase the resin pressure. The resin pressure is preferably 1 to 30 MPa, more preferably 1 to 25 MPa, and even more preferably 1 to 20 MPa. Furthermore, any known thermoplastic resin suitable for various applications can be used as the virgin material without any limitations. Examples include homopolymers or copolymers made of α-olefins such as ethylene, propylene, and butene, as well as styrene-α-olefin block copolymers, polyamides, polyester resins, polyvinyl chloride, styrene resins, methacrylic resins, polycarbonates, and polyacetals. These can be used individually or in mixtures of two or more resins. Examples of the modified resin include so-called compatibilizers, such as acrylic elastomers or styrene elastomers. Examples of known and commonly used additives include colorants, antistatic agents, antioxidants, heat stabilizers, UV stabilizers, UV absorbers, foaming agents, flame retardants, flame retardant aids, rust inhibitors, and mold release agents (such as metal salts and esters of fatty acids with 18 to 30 carbon atoms, including stearic acid and montanic acid, and polyolefin waxes such as polyethylene). Furthermore, synthetic resins and elastomers as listed below can also be mixed and used. Examples of these synthetic resins include polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylate, polyethylene, polypropylene, polytetrafluoroethylene, polydifluoroethylene, polystyrene, ABS resin, epoxy resin, silicone resin, phenolic resin, urethane resin, and liquid crystal polymer. Examples of elastomers include polyolefin rubber, fluororubber, and silicone rubber. When virgin material, modified resin, and additives are blended, the total amount of virgin material, modified resin, and additives blended may be preferably 10 to 70 parts by mass, more preferably 30 to 50 parts by mass, per 100 parts by mass of the film piece.

[0099] In the melt-mixing process of this embodiment, for example, when using a single-screw extruder or a twin-screw extruder as described later, general melt-mixing conditions can be used. The average temperature of the cylinder temperature (or barrel temperature) is preferably 180 to 260°C, more preferably 190 to 250°C, and even more preferably 200 to 240°C. The average temperature of the cylinder (or barrel) refers to the arithmetic mean of the temperature inside the cylinder on the raw material inlet side (the temperature of the cylinder directly below the hopper), the temperature inside the cylinder in the center, and the temperature inside the cylinder on the outlet side. Furthermore, to achieve a better melt-mixing state, the raw material inlet temperature (the so-called hopper barrel temperature) is preferably about -50 to -100°C lower than the temperature at the center of the cylinder. More preferably, the temperature is gradually increased in a gradient from the raw material inlet temperature towards the center. If the temperature at the center of the cylinder is below 180°C, melt-mixing becomes difficult, and if it is above 260°C, the physical properties of the manufactured recycled pellets deteriorate significantly. The temperature directly below the film piece input (the so-called hopper) is preferably 20 to 100°C to prevent the film piece from melting too quickly and causing bridging.

[0100] In the melt-mixing process of this embodiment, the rotational speed of the (iii) screw loaded into the single-screw or twin-screw extruder, which will be described later, is preferably 50 to 500 rpm, more preferably 80 to 400 rpm, and even more preferably 100 to 300 rpm. If the rotational speed of the screw is too low, it is difficult to produce uniform recycled pellets during melting, and if it is too high, the physical properties of the recycled pellets produced by the heat generated during mixing will be significantly reduced.

[0101] The preferred screw configuration described in (iv) above will be explained in detail later with reference to the drawings, but it is preferable to use a screw equipped with a kneading block having one or more kneading discs.

[0102] In the cured product obtained by cooling the molten compound obtained in the above molten compounding process, the dispersion diameter of the domain phase derived from the functional layer in the cured product is 10 μm or less, and the dispersion volume of the domain phase derived from the functional layer in the cured product is 20 μm. 3 By controlling the process as described below, the functional layer, refined into particles with appropriate dispersion volume and dispersion diameter, can be dispersed in the cured product as a domain phase. This reduces the localized increase in the interface area with the sea phase, such as aggregation of domain phases or formation of large domain phases. As a result, even when the compatibility between the sea phase and the island phase is low, localized fracture at the interface between the island phase and the sea phase due to impact can be reduced, thereby improving the impact resistance of the molded product as a whole.

[0103] In this embodiment, the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less, preferably 8 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. On the other hand, the lower limit of the dispersion diameter of the functional layer is preferably greater than 0 μm. These upper and lower limits can be combined arbitrarily. The dispersion diameter of the domain phase derived from the functional layer is the so-called D(90%) value, which is the 90% integral of a differential distribution curve created with the diameter of each particle on the horizontal axis and the frequency on the vertical axis. The measurement method is the same as described in the Examples section.

[0104] The dispersion volume of the domain phase derived from the functional layer in this embodiment is 20 μm 3 The following is preferred: 1 μm 3 More than 18μm 3 More preferably 3 μm 3 More than 15μm 3 The following applies. These upper and lower limits can be combined in any way. The method for measuring the dispersion volume of the domain phase derived from the functional layer is the same as described in the Examples section. Furthermore, the dispersion volume represents the volume assuming that the domain phase derived from the functional layer is a sphere with a dispersion diameter.

[0105] Generally, extrusion equipment used for melting and kneading plastic materials such as resins includes various devices such as kneaders, roll mills, single-screw extruders, twin-screw extruders, and rotor-type twin-screw kneaders. On the other hand, the extrusion equipment used in the melting and kneading process of this embodiment may be a single-screw extruder, twin-screw extruder, tri-screw extruder, conical extruder, and kneader-type kneader equipped with a predetermined screw. The predetermined screw is equipped with a kneading block having one or more kneading discs. Furthermore, by kneading at a screw rotation speed of 300 rpm or more, the dispersion diameter of the domain phase derived from the functional layer contained in the laminate is 10 μm or less, and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 It is characterized by being melt-mixed to the following state.

[0106] <Extruder> In this specification, a single-screw extruder and a twin-screw extruder, which are examples of extrusion apparatus, will be described below with reference to Figures 1 to 8. Figure 1 shows a schematic diagram of an extruder 10 (for example, a single-screw or twin-screw extruder), which is an example of the extruder of this embodiment. Figure 2 is a schematic diagram showing the differences between a single-screw extruder and a twin-screw extruder. Figure 3 is a schematic diagram showing an example of a screw 1. And Figure 4 is a schematic diagram showing another example of a screw 1.

[0107] As shown in Figure 1, the extruder 10 (for example, a single-screw or twin-screw extruder) is an extruder having a screw 1 (dotted line), a hopper 2, and a cylinder (also referred to as a barrel) 3 equipped with a heater 5. The screw 1, which rotates inside the cylinder 3 heated by the heater 5 and driven by a drive motor (not shown), melts the raw material (for example, one or more components selected from the group consisting of film pieces containing recycled polyolefin resin and, if necessary, virgin material, modified resin, and additives) 4 (hereinafter simply referred to as raw material 4) supplied from the hopper 2, sending it to the die section 6, which is the outlet side of the cylinder 3. More specifically, the extruder 10 (for example, a single-screw or twin-screw extruder) comprises a drive motor (not shown), a tubular cylinder 3 provided adjacent to the drive motor and wound around a heater 5, a screw 1 positioned inside the tubular cylinder 3 and connected to the drive motor, a hopper 2 for supplying raw material 4, and a die section 6 provided downstream from the hopper 2 in the extrusion direction (towards the die section 6) and equipped with a discharge die for recovering the molten mixture. The screw 1 is inserted into the cylinder 3 that extends from the hopper 2 to the die section 6. Then, when the raw material 4 is melted and kneaded in the cylinder 3 and the molten mixture is recovered from the die section 6 which is in communication with the inside of the cylinder 3, the molten mixture obtained from the die section 6 is passed directly through the cooling water tank 7, and the molten mixture is stretched into a thread-like shape and cooled to obtain strands 9, which can then be processed in the pelletizer 8 to recover them as pelletized material. Figure 1 shows an example of recovering pelletized material for ease of explanation, but depending on the shape of the die section 6, which is the part that recovers the molten mixture containing recycled polyolefin resin that is conveyed while being kneaded by screw 1, it can be molded into various product shapes such as film, plate, injection molded product, and pellets, depending on the purpose.

[0108] In addition, while Figure 1 shows an example of a molding machine connected to the extrusion device 10 (for example, a single-screw or twin-screw extruder) used in the manufacturing method of the molded product of this embodiment, the molded product may also be recovered by a hot-cut method or an underwater-cut method.

[0109] Figure 2 is an enlarged view showing an example of a cylinder 3 equipped with the screw 1 shown in Figure 1. The left side of Figure 2 is a cross-sectional perspective view showing an example of a single screw 1 inserted into a tubular cylinder 3 around which a heater 5 is wound in a single-screw extruder. On the other hand, the right side of Figure 2 is a cross-sectional perspective view showing an example of two screws 1 inserted into a tubular cylinder 3 around which a heater 5 is wound in a twin-screw extruder. The screw 1 shown in Figure 2 is a cross-sectional perspective view of the base end side (hopper 2 side) of the tubular cylinder 3, and the structure of the base end side of the shaft body of the screw 1 shown in Figure 2 (16 in Figure 3, 17 in Figure 4) is an example of a grooved structure with a thread-like protrusion a. In other words, the base end of the screw 1 in Figure 2 has a so-called screw-like structure in which a helical thread-like protrusion a is formed. Furthermore, an extruder with primarily one screw is called a single-screw extruder (or monoscrew extruder), while an extruder with two screws is called a twin-screw extruder.

[0110] As shown in Figure 2, the screw 1 has a thread-shaped protrusion a (for example, 11a or 14a in Figure 5) around the base end side (hopper 2 side) of the shaft body. The structure of this thread a allows it to act as a groove for feeding the raw material 4 from the hopper 2 side of the cylinder 3 to the die section 6, which is the outlet side. The raw material 4 supplied from the hopper 2 to the cylinder 3 as shown in Figure 1 is kneaded by the meshing of the screws 1, the shear generated between the outer circumference of the screws 1 and the inner circumference of the cylinder 3, etc. In the case of a twin-screw extruder, kneading occurs by the meshing of the two screws 1, the shear generated between the outer circumference of the screws 1 and the inner circumference of the cylinder 3, etc. Therefore, in the case of a twin-screw extruder, the rotation directions of the two screws 1 may be the same or different. In this embodiment, the extrusion apparatus 10 is preferably a twin-screw extruder. In a twin-screw extruder, after supplying the raw material 4 from the hopper 3 into the cylinder 3, the raw material 4 is melted and kneaded by a screw 1 located inside the cylinder 3 while being transported to the die section 6, and the molten kneaded raw material 4 is discharged to the outside of the cylinder 3 through the die section 6. The twin-screw extruder may further include a reduction gear for adjusting the rotational speed of the screw 1. Twin-screw extruders tend to knead better than single-screw extruders, resulting in improved quality (homogeneity, dispersibility, etc.). Therefore, different resins, additives, colorants, pigments, color masterbatches, etc., can be kneaded together and dispersed more homogeneously.

[0111] The following describes in detail the components of the extrusion device 10 (for example, a single-screw or twin-screw extruder): the hopper 2, cylinder 3, die section 6, and screw 1.

[0112] <Hopper> The hopper 2 in this embodiment is attached to an opening located at the top of the main body of the extruder 10 (for example, a single-screw or twin-screw extruder), and supplies raw material 4 into the hopper 2. The inlet located at the bottom of the hopper 2 communicates with the upstream opening of the cylinder 3, and the raw material 4 that has reached the raw material supply inlet of the hopper 2 can be fed into the cylinder 3 through this opening.

[0113] <Cylinder> In this embodiment, the cylinder 3 is a tubular body configured to allow the screw 1 to be inserted inside. A hopper 2 is attached near one end, and a die section 6 is attached near the other end. The cylinder 3 has the hopper 2 attached to the upstream side and the die section 6 attached to the downstream side, forming a transport path for the raw material 4 between the hopper 2 and the die section 6. Figures 1 and 2 also show, as an example, a configuration in which a heater 5 is wound around the outside of the cylinder 3. Known heating means such as the heater 5 for melting the raw material 4 can be used.

[0114] <Dice Club> In this embodiment, the die section 6 is an outlet attached to the downstream end of the cylinder 3. The shape of the molding die section 6 can be appropriately changed according to the desired molded product. Normally, a die section 6 for pellet molding is used, but it is also possible to use a die section 6 for film molding or a die section 6 for sheet molding.

[0115] <Screw> The screw 1 in this embodiment only needs to include a kneading block having one or more kneading discs. As a result, the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less, and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 The following will make it easier to control. The following provides a detailed explanation of Screw 1, the kneading disk, and the kneading block that constitute Screw 1, with reference to Figures 3 to 8. Generally, the screw of an extruder is mainly composed of three parts: a feeding section, a compression section, and a metering section. Similarly, it is preferable that the screw 1 of this embodiment also has three parts: a feeding section, a compression section, and a metering section. As shown in Figure 3, the screw 1 has a feeding section E1, a compression section E2, and a metering section E3. The feeding section E1 mainly refers to blocks with roughly the same height between the grooves on the surface of the screw 1, from 3 to 8 pitches, directly below the hopper 2 to which the raw material 4 is supplied. The feeding section E1 has the role of facilitating the transport of the raw material 4 supplied from the hopper 2 to the die section 6, for example, while remaining mostly solid, so it is preferable that the grooves be relatively deep. Figure 3 shows a so-called full-flight screw block 11 as an example of the supply unit E1. Next, the compression section E2 is the part where the raw material 4, which has received residual heat from the supply section E1, is compressed, heated, and kneaded, changing most of the raw material 4 into a molten state. Therefore, it is preferable that the compression section E2 has the effect of compressing the solid raw material 4 and sending back the air, moisture, and volatile components contained inside to the supply section E1. Furthermore, it is possible to change the raw material 4 from a solid to a viscoelastic material. For this reason, a taper (gradient) may be provided in the depth of the grooves of the crests of the screw 1. Figure 3 shows an example of a kneading block 15 (5 discs) having one or more kneading discs P (see Figures 6-8) as an example of a compression section E2. The metering section E3 refers to the tip of the screw 1 (the end of the screw 1 on the die section 6 side), and is the part that sends the raw material 4, which has been mostly melted in the compression section E2, to the die section 6 at a constant pressure and in fixed amounts. Figure 3 shows a so-called full-flight screw block 11 as an example of the metering section E3.

[0116] Therefore, the screw 1 shown in Figure 3 is assembled in the following order from the upstream side of the cylinder 3: full-flight screw block 11, kneading block 15, and full-flight screw block 11. The full-flight screw block 11 is composed of a combination of individual parts (screw members) called full-flight screw members (see Figure 5 below). On the other hand, the kneading block 15 is composed of a combination of individual parts (screw members) called kneading discs P (see Figure 6 below). In other words, the screw 1 in Figure 3 has a shaft body 17 and a screw member having a through hole 20 (see Figures 5-8 described later) into which the shaft body 17 is inserted, and the screw member is assembled in the order of full-flight screw block 11, kneading block 15, and full-flight screw block 11. Figure 4 shows an example of another preferred embodiment of the screw 1 of this embodiment. The screw 1 shown in Figure 4 is assembled in the following order from the upstream side of the cylinder 3: full-flight screw block 11, kneading block 15, (reverse-feed) full-flight screw block 14, full-flight screw block 11, kneading block 12R, and full-flight screw block 11. The (reverse-feed) full-flight screw block 14 is composed of a combination of individual parts (screw members) called (reverse-feed) full-flight screw members (see Figure 5 below). On the other hand, the kneading block 12R is composed of a combination of individual parts (screw members) called kneading discs P (see Figure 7 below). In other words, the screw 1 in Figure 4 has a shaft body 16 and a screw member having a through hole 20 (see Figures 5-8 described later) into which the shaft body 16 is inserted, and the screw member is assembled in the following order: full-flight screw block 11, kneading block 15, (reverse-feed) full-flight screw block 14, full-flight screw block 11, kneading block 12R, and full-flight screw block 11. Therefore, each screw 1 in Figures 3 and 4 is constructed by combining these screw members, and each screw 1 can be inserted and fixed inside the cylinder 3 shown in Figures 1 and 2. In the case of a single-screw extruder, one screw 1 is inserted and fixed inside the cylinder 3; in the case of a twin-screw extruder, two screws 1 are inserted and fixed inside the cylinder 3; and in the case of a tri-screw extruder, three screws 1 are inserted and fixed inside the cylinder 3. By using an extruder equipped with a screw 1 having a kneading block 15, as shown in Figures 3 and 4, the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less, and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 The following makes it easier to control. In Figure 4, an example of a supply unit E1 is shown, in which a full-flight screw block 11 is connected in order to a kneading block 15 as a compression unit E2-1, a (reverse-feed) full-flight screw block 14 as a compression unit E2-2, a full-flight screw block 11 as a compression unit E2-3, a kneading block 12R as a compression unit E2-4, and a full-flight screw block 11 as a metering unit E3. The following describes each of these screw components, the screw blocks.

[0117] <<Full Flight Screw Block>> In this embodiment, the full-flight screw block 11 may be composed of one type of progressive full-flight screw member, or it may be composed of multiple identical progressive full-flight screw members connected together, or it may be composed of one or more progressive full-flight screw members with different flight shapes or lead lengths connected together. A full-flight screw member is a full-flight type screw member on which one or more flights (spiral or threaded protrusions a) are provided spirally on the shaft body 16, 17. There are two types of full-flight screw members: a forward-feed full-flight screw member 11 equipped with threaded protrusions 11a to transport the raw material 4 supplied from the hopper 2 into the cylinder 3 to the die section 6 side (downstream), and a reverse-feed full-flight screw member 14 equipped with flights 14a (threaded protrusions a) in the opposite direction to the forward-feed full-flight screw 11 to temporarily hold the molten mixture being transported downstream (see Figure 5).

[0118] Figure 5 shows the front view (left) and side view (right) of the forward-feed full-flight screw block 11 and the reverse-feed full-flight screw block 14. In Figure 5, Lf represents the lead length of the full-flight screw member. The "lead length" of the full-flight screw member is the length of the screw member in the X-axis direction when flights 11a and 14a complete one rotation. Both the forward-feed full-flight screw block 11 and the reverse-feed full-flight screw block 14 allow the respective lead lengths Lf to be changed to adjust the mixing process. Furthermore, the forward-feeding full-flight screw block 11 and the reverse-feeding full-flight screw block 14 may have mixing screws with notches in the flights 11a and 14a shown in Figure 5 for adjusting the mixing process.

[0119] <<Kneading Block>> The screw 1 of this embodiment includes a kneading block having one or more kneading discs P. The kneading block may be configured by using one or more kneading blocks having one or more kneading discs P individually, or by using various combinations of kneading blocks having one or more kneading discs P. The number of kneading discs P constituting the kneading block may be one or more, preferably 2 to 10, and more preferably 3 to 7. Preferably, at least one kneading block has one of the following configurations (v) to (vi). (v) The kneading block is preferably made by connecting two to nine kneading discs P. (vi) The kneading block preferably has two to nine kneading discs P, and the angle between adjacent kneading discs P along their long axes is greater than 0° and less than 90°. The angle between adjacent kneading discs along their long axes refers to the minimum angle between adjacent kneading discs P along their long axes. At least one kneading block has one of the configurations (v) to (vi) above, so that the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less and the dispersion volume of the domain phase derived from the functional layer is 20 μm 3 The following makes it easier to control.

[0120] An example of the kneading block of this embodiment will be described below with reference to the examples shown in Figures 6 to 8. The kneading block 15 shown in Figure 6 is constructed by arranging multiple kneading discs P adjacent to each other in the X-axis direction. The number of kneading discs P can be set to an appropriate number to adjust the degree of kneading. For example, it is particularly preferable that the number of kneading discs P be 3 to 7. Figures 6-8 all show examples with five kneading disks P, but the scope of this disclosure is not limited to this. The kneading disc P is a disc-shaped member having two parallel elliptical surfaces. A through hole 20 (Figures 6-8) is provided in the center of the kneading disc P through which the shaft bodies 16, 17 (Figures 3, 4) are inserted, and the ends of the elliptical surfaces in the direction of the major axis have notches. The distance between the two parallel surfaces of the kneading disc P is defined as the average thickness La, and the diameter (major axis) in the direction of the major axis of the elliptical surface is defined as Da.

[0121] As shown in the left diagram of Figure 6, the kneading block 15 is arranged with the rotational phase (helix angle), which is the minimum angle between the long axes of adjacent kneading discs P, alternating by α degrees. The kneading block 15 shown in Figure 6 is an example where the rotational phase (helix angle) α is 90°. Because the kneading discs P are arranged with the rotational phase (helix angle) alternating by α degrees, efficient melt kneading can be performed due to the shearing action between the disc surfaces of adjacent kneading discs P and the turning effect of the discontinuously arranged group of kneading discs P. Furthermore, Figures 6-8 show examples where the rotational phase (torsion angle) α, which is the minimum angle between the long axes of adjacent kneading discs P, is all equal. However, they do not have to be arranged at equal angles. For example, when a kneading block is constructed with three kneading discs P, the minimum angle between the long axes of the first and second kneading discs P may be 60°, and the minimum angle between the long axes of the second and third kneading discs P may be 30°.

[0122] Furthermore, the minimum angle between the long axes of adjacent kneading disks can be arbitrarily selected within the range of greater than 0° to 90°. Therefore, the rotational phase (torsion angle) α between adjacent kneading disks P in the kneading block 15 only needs to be greater than 0° and less than or equal to 90°.

[0123] The kneading block 12R shown in Figure 7 is an example where the rotational phase (helix angle) α between adjacent kneading disks P is 45°. Except for the difference in rotational phase (helix angle) α, the configuration is identical to the kneading block 15 in Figure 6. Furthermore, the kneading block 12L shown in Figure 8 is another example where the rotational phase (helix angle) α between adjacent kneading disks P is 45°. Except for the difference in rotational phase (helix angle) α, the configuration is identical to the kneading block 15 in Figure 6. The difference between the kneading blocks shown in Figures 7 and 8 is the difference in the helix angle of the kneading disks P, which is clockwise and counterclockwise. That is, the kneading block 12R shown in Figure 7 is a kneading block combined with adjacent kneading disks P with a right-hand helix angle of 45° in phase. On the other hand, the kneading block 12L shown in Figure 8 is a kneading block combined with adjacent kneading disks P with a left-hand helix angle of 45° in phase. For example, in this embodiment, when using a twin-screw extruder, two screws 1 are required. One configuration is to have one or more kneading blocks 12R as the first screw 1, and one or more kneading blocks 12L as the second screw 1, so that the rotational directions of the two screws 1 are different. By using an extruder equipped with a screw 1 having the kneading block 15 described above, the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less, and the dispersion volume of the domain phase derived from the functional layer is 20 μm. 3 The following makes it easier to control. As a result, the functional layer, which has been refined into particles with an appropriate dispersion volume and dispersion diameter, can be dispersed in the cured product as a domain phase, which is expected to improve the impact resistance of the molded product as a whole.

[0124] <Melting and mixing conditions and extrusion conditions> When a single-screw extruder or a twin-screw extruder 10 is used as the extrusion device, the screw rotation speed is 300 rpm or higher, preferably 300 rpm to 700 rpm. A screw rotation speed of 300 rpm or higher allows for the acquisition of a more uniform molten mixture. Furthermore, a screw rotation speed of 700 rpm or lower can suppress a significant decrease in the physical properties of the molten mixture. From a similar viewpoint, the lower limit of the screw rotation speed is more preferably 400 rpm or higher, and even more preferably 500 rpm or lower.

[0125] In the melt-mixing process, the raw material 4 may be film pieces containing the recycled polyolefin resin obtained in the wet crushing process, or a composition containing the recycled polyolefin resin and other resins. The other resins are preferably those compatible with the recycled polyolefin resin, and specifically include thermoplastic resins (virgin thermoplastic resins) such as polyethylene resin and polypropylene resin. These other resins may be used individually or in combination of two or more.

[0126] The content of recycled polyolefin resin in the total raw material 4 used in the melt-mixing process is preferably 50% by mass or more. In this case, the recycling rate is at a sufficiently high level. The above-mentioned content of recycled polyolefin resin refers to the proportion of recycled polyolefin resin in the total raw material 4 used in the melt-mixing process. From a similar viewpoint, the content of recycled polyolefin resin is more preferably 60% by mass or more, even more preferably 75% by mass or more, and even more preferably 90% by mass or more. It is also preferable that the content of recycled polyolefin resin is 100% by mass (i.e., the raw material 4 used in the melt-mixing process consists only of the above-mentioned recycled polyolefin resin).

[0127] The above composition subjected to the melting and kneading process may contain appropriate amounts of alkali metal, alkaline earth metal, or zinc metal soap; hydrotalcite; surfactants such as nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants; antistatic agents; flame retardants such as halogen-based, phosphorus-based, or metal oxides; lubricants such as ethylenebisalkylamide; antioxidants; ultraviolet absorbers; fillers; colorants; peroxides, etc., to the extent that they do not impair the effects of the present invention.

[0128] In this embodiment, the melt-mixing temperature in the melt-mixing process must be, for example, 20°C or higher and 100°C or lower than the melting point of the recycled polyolefin resin. If the melt-mixing temperature is not 20°C or higher than the melting point of the recycled polyolefin resin, it may not be possible to specifically change the crystalline structure and higher-order structure of the recycled polyolefin resin, and the impact resistance of the final molded product may not be improved. Also, if the melt-mixing temperature is not 120°C or lower than the melting point of the recycled polyolefin resin, it may not be possible to improve the mechanical properties such as impact resistance of the final molded product due to overheating.

[0129] The supply rate of raw material 4 during extrusion is preferably 5 kg / h or more and 100 kg / h or less. If the supply rate is 5 kg / h or more, the resin pressure during extrusion will increase, and a better mixing state can be formed. Also, if the input rate is 100 kg / h or less, equipment malfunctions such as clogging can be suppressed. From a similar viewpoint, the input rate of raw material 4 during extrusion is more preferably 50 kg / h or less, and even more preferably 30 kg / h or less.

[0130] The resin pressure during extrusion is preferably between 1 MPa and 30 MPa. A resin pressure of 1 MPa or higher allows for a better mixing state. Furthermore, a resin pressure of 30 MPa or lower can suppress equipment malfunctions such as clogging. From a similar viewpoint, the resin pressure during extrusion is more preferably 25 MPa or lower, and even more preferably 20 MPa or lower.

[0131] (Collection process) Furthermore, the manufacturing method of the molded product in this embodiment may include a take-up step as a melt-mixing step, in which the molten mixture extruded in the melt-mixing step is taken up as a strand 9. The take-up step can be carried out using the same apparatus as the melt-mixing step (see Figure 1). In other words, as shown in Figure 1, after melting and kneading the laminate under the predetermined conditions described in the (melting and kneading process) section above to obtain a molten mixture, when recovering the molten mixture from the die section 6 which is in communication with the cylinder 3, the molten mixture obtained from the die section 6 is passed directly through the cooling water tank 7, and the molten mixture is stretched into a thread-like shape and cooled to obtain a strand 9. The entire process from melting and kneading the laminate to taking up the strand 9 can be performed using the same apparatus.

[0132] In addition, while Figure 1 shows an example of a molding machine connected to an extrusion device (for example, a single-screw or twin-screw extruder 10) used in the manufacturing method of the molded product of this embodiment, the molded product may also be recovered by a hot-cut method or an underwater-cut method.

[0133] The take-up speed of the strand 9 in the take-up process is preferably, for example, 8 m / min or more and 50 m / min or less. If the take-up speed of the strand 9 is 8 m / min or more, it can more effectively bring about specific changes in the crystalline structure and higher-order structure of the recycled polyolefin resin, and the extensibility of the final molded product can be further improved. If the take-up speed of the strand 9 is 50 m / min or less, the occurrence of defects such as wire breakage can be suppressed. From a similar viewpoint, it is more preferable that the take-up speed of the strand 9 in the take-up process is 30 m / min or less.

[0134] (molding process) In the method of this embodiment, the molding process involves molding using strands 9. This molding process ultimately yields a molded product. Alternatively, the molding process may also involve using pellets obtained by cutting strands 9 with a pelletizer 8 or the like. The final shape of the molded product is not particularly limited and can be modified as appropriate depending on the purpose. In the molding process, the strands 9 or pellets can be used for heat molding. The heat molding method is not particularly limited and includes, for example, injection molding, extrusion molding, blow molding, compression molding, etc.

[0135] The heating temperature during heat molding is preferably 180°C or higher, 190°C or higher, or 200°C or higher, and also preferably 260°C or lower, 250°C or lower, or 240°C or lower.

[0136] In the case of heat molding using a mold (such as injection molding), the mold temperature is preferably between 20°C and 60°C. If the mold temperature is 20°C or higher, the fluidity of the molten resin can be maintained, preventing filling defects and the generation of air bubbles. If the mold temperature is 60°C or lower, the cooling rate of the molten resin can be appropriately maintained, suppressing the shrinkage rate after molding. From a similar viewpoint, the mold temperature is more preferably 30°C or higher, and even more preferably 50°C or lower.

[0137] The molding time during the above heat molding process is preferably 10 seconds or more and 45 seconds or less. If the molding time is 10 seconds or more, a good molded product can be obtained by sufficient cooling. Also, if the molding time is 45 seconds or less, productivity can be maintained well. From a similar viewpoint, the molding time is more preferably 20 seconds or more, even more preferably 25 seconds, even more preferably 40 seconds or less, and even more preferably 35 seconds or less.

[0138] The holding pressure during heat molding is preferably between 20 MPa and 100 MPa. A holding pressure of 20 MPa or higher can improve the quality of the molded product and its surface. Furthermore, a holding pressure of 100 MPa or lower can suppress mold release defects. From a similar viewpoint, the holding pressure during heat molding is more preferably 30 MPa or higher, even more preferably 40 MPa or higher, even more preferably 70 MPa or lower, and even more preferably 60 MPa or lower. [Examples]

[0139] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to the following examples. In addition, unless otherwise specified, "%" in the compositions of the following examples means "mass%".

[0140] <Preparation of the polyolefin film layer> The following materials were prepared as polyolefin film layers. PP1...Polypropylene film, manufactured by Toyobo Co., Ltd., "P2161", thickness: 20 μm, melting point of the constituent polypropylene: 165°C PP2...Polypropylene film, manufactured by Toyobo Co., Ltd., "P1128", thickness: 30 μm, melting point of the constituent polypropylene: 145℃ PP3...Polypropylene film, manufactured by Toray Industries, Inc., "VM-CPP", thickness: 30 μm, melting point of constituent polypropylene: 145°C

[0141] <Preparation of composition for detachable primer layer (1)> 0.32 g of terephthalic acid (TPA), 0.32 g of isophthalic acid (IPA), 0.13 g of ethylene glycol (EG), and 0.23 g of diethylene glycol (DEG) were mixed and reacted to prepare polyol compound (a) (aromatic polyester polyol).

[0142] Next, 0.74 g of polyol compound (a), 0.20 g of isophorone diisocyanate, and 0.06 g of 2,2'-dimethylolpropionic acid were charged into a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube, and the mixture was reacted at 75°C for 8 hours under a nitrogen stream to obtain urethane resin (1).

[0143] Next, the urethane resin (1) was diluted with isopropyl alcohol to a solid content concentration of 10% to obtain a composition for a detachable primer layer (1).

[0144] <Preparation of composition for detachable primer layer (2)> A composition for a detachable primer layer (2) was obtained by mixing 10 parts by mass of PVA1 (polyvinyl alcohol, PVA-A, weight-average molecular weight: 48,000), 45.0 parts by mass of water, and 45.0 parts by mass of ethanol.

[0145] <Preparation of composition for detachable primer layer (3)> A composition for a detachable primer layer (3) was obtained by mixing 10 parts by mass of PVA-2 (polyvinyl alcohol, manufactured by Nippon Vinegar Bi-Poval Co., Ltd., J-POVAL JF-05, weight-average molecular weight: 22,000), 0.5 parts by mass of polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd.), 44.5 parts by mass of water, and 45.0 parts by mass of ethanol.

[0146] <Preparation of composition for detachable primer layer (4)> A composition for a detachable primer layer (4) was obtained by mixing 10 parts by mass of PVA-3 (polyvinyl alcohol, manufactured by Nippon Vinegar Bi-Poval Co., Ltd., J-POVAL JF-17, weight-average molecular weight: 75,000), 1.0 part by mass of polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd.), 44.0 parts by mass of water, and 45.0 parts by mass of ethanol.

[0147] <Preparation of composition for detachable primer layer (5)> A composition for a detachable primer layer (5) was obtained by mixing 10 parts by mass of PVA-4 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd., KURARAY POVAL 60-98, weight-average molecular weight: 106,000), 3.0 parts by mass of polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd.), 42.0 parts by mass of water, and 45.0 parts by mass of ethanol.

[0148] <Preparation of adhesive layer composition> As the adhesive layer composition, DICDRY® LX-510 and DICDRY® KW-75, both manufactured by DIC Corporation, were mixed in a mass ratio of LX-510:KW-75 = 9:1, and further diluted with ethyl acetate as a solvent (a polyurethane-based two-component curing laminate adhesive).

[0149] <Preparation of composition for the printing layer (blue)> For the printing layer (blue), a gravure ink for surface printing (DIC Graphics, Glossa 507 primary color blue S2) was used, with its viscosity adjusted to 15 seconds (25°C) using a Zaan cup #3 manufactured by Rigosha.

[0150] <Fabrication of the laminate (LAM1)> On a PP1 polyolefin film layer, a gravure printing press equipped with a gravure plate with a plate depth of 22 μm applies a coating amount (solid content) of 0.5 g / m². 2 The deleasible primer layer composition (1) was applied without gaps (in a solid form), dried by passing it through a 70°C oven, and then left at room temperature for one day to form the deleasible primer layer (1). Next, the printing layer (blue) composition was printed in a solid form onto this deleasible primer layer (1) using a gravure printing press equipped with a gravure plate with a plate depth of 43 μm, and dried or cured by passing it through a 70°C oven to form the printing layer. On the other hand, an adhesive layer composition was applied to the PP1 surface that did not have the printed layer formed on it, and the surface coated with the adhesive layer composition was bonded to PP2. Then, aging was performed at 40°C for 5 days to obtain a laminate (LAM1) having a layer structure of "printed layer (blue) / desorption primer layer (1) / PP1 / adhesive layer / PP2".

[0151] <Fabrication of the laminate (LAM2)> A laminate (LAM2) having the layer configuration of "printing layer (blue) / depositionable primer layer (2) / PP1 / adhesive layer / PP2" was obtained in the same manner as LAM1, except that composition (2) for the depositionable primer layer was used instead of composition (1) for the depositionable primer layer in LAM1.

[0152] <Fabrication of the laminate (LAM3)> A laminate (LAM3) having the layer configuration of "printing layer (blue) / depositionable primer layer (3) / PP1 / adhesive layer / PP2" was obtained in the same manner as LAM1, except that composition (3) for the depositionable primer layer was used instead of composition (1) for the depositionable primer layer in LAM1.

[0153] <Fabrication of the laminate (LAM4)> A laminate (LAM4) having the layer configuration of "printing layer (blue) / depositionable primer layer (4) / PP1 / adhesive layer / PP2" was obtained in the same manner as LAM1, except that composition (4) for the depositionable primer layer was used instead of composition (1) for the depositionable primer layer in LAM1.

[0154] <Fabrication of the laminate (LAM5)> In LAM1, a laminate (LAM5) was obtained having a layer structure of "printing layer (blue) / detachable primer layer (5) / PP1 / adhesive layer / PP3", except that detachable primer layer composition (5) was used instead of detachable primer layer composition (1) and PP3 was used instead of PP2.

[0155] Table 1 shows the layer structure of each laminate created.

[0156] [Table 1]

[0157] <Manufacturing of molded products> (Pre-treatment process) Each prepared laminate was fitted with a 10mm diameter screen and fed into a dry crusher with cooling water flowing through it. The laminate was pre-treated so that its dimensions were approximately 5-10mm in the short direction and 10-20mm in the long direction. The input rate for each laminate was also adjusted to 1kg / min.

[0158] (Soaking process) The laminate after the pretreatment process was subjected to either the following immersion process (A) or immersion process (B). Immersion process (A): A desorbing solution was selected from desorbing solutions (1) to (4) shown in Table 2, and 2 kg of laminate was placed in 15 L of the desorbing solution. The laminate was then immersed in the desorbing solution at 40°C for 16 hours. Immersion process (B): A desorbing solution was selected from desorbing solutions (1) to (4) shown in Table 2, and 2 kg of laminate was placed in 15 L of the desorbing solution. The laminate was then immersed in the desorbing solution at 75°C for 120 minutes while stirring at 300 rpm using a three-one motor.

[0159] [Table 2]

[0160] Alkali: Sodium hydroxide Surfactant (1): "DSK NL Dash 403" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyalkylalkylene lauryl ether, HLB value = 6.5 Surfactant (2): "DSK NL Dash 408" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., polyalkylalkylene lauryl ether, HLB value = 12.5 Surfactant (3): NOF Corporation, "PB-300", cationic surfactant

[0161] (Washing process) After the immersion process, the laminate was rinsed with water using a shower until the pH was within the range of 7 to 12 to remove the alkali, and then lightly dehydrated by placing it in a colander.

[0162] (Wet grinding process) Next, the laminate obtained in the above washing step was subjected to the following wet grinding step (a), wet grinding step (b), or stirring step (c) to obtain a film piece containing recycled polyolefin resin. Wet grinding process (a): A continuous vibratory mill (continuous shaking device) manufactured by Chuo Kakoki Co., Ltd. was used as the wet grinder. 2 kg of laminate was used, and the ratio of laminate to water was adjusted to 150 g / 1 L. The vibratory mill used was equipped with dispersion media in the container. A 19 mm diameter rod was used as the dispersion media, and the filling rate of the dispersion media in the container was 15 vol%. The water inflow rate was adjusted so that the loaded laminate was discharged from the machine in 1 minute, and the laminate was shaken and wet ground. The processing speed of the laminate at this time was 500 g / min. Wet grinding process (b): A Beat Refiner manufactured by Satomi Seisakusho Co., Ltd. was used as the wet grinder. 2 kg of the laminate obtained in the above washing process was used, and the ratio of laminate to water was adjusted to 100 g / 1 L. The blade design of the fixed and rotating blades was such that the blades, which were arranged radially, were tilted at 30° from the radial direction, the blade width of the rotating blade was 3 mm, the groove width between the blades was 0.3 mm, and the blade height was 3 mm. The clearance between the fixed and rotating blades was set to 1 mm, the peripheral speed was 24 m / s, and the water inflow was adjusted so that the input film was discharged from the machine in 1 minute. At that time, the laminate was processed at 500 g / min. Agitation process (c): As a wet grinder, a Shinto Kagaku Co., Ltd. Three One Motor BLW-3000 agitator was used, and 2 kg of the laminate obtained in the above washing process was used, and the agitator was operated at a rotation speed of 600 rpm in 15 L of water. Furthermore, the surface roughness of the film pieces containing recycled polyolefin resin obtained in wet grinding steps (a) and (b) was 0.7 μm or more. More specifically, the surface roughness of the film pieces containing recycled polyolefin resin obtained in wet grinding step (a) was 0.9 μm or more, and the surface roughness of the film pieces containing recycled polyolefin resin obtained in wet grinding step (b) was 0.7 μm or more. On the other hand, the surface roughness of the film piece containing the recycled polyolefin resin obtained in the stirring step (c) was less than 0.7 μm. The surface roughness was calculated by measuring the surface roughness Sa of a 500 μm × 600 μm area using a white light interference microscope manufactured by Ryoka Systems Co., Ltd.

[0163] (Rinsing process) The recycled polyolefin resin film pieces obtained in the shaking process were washed with a rinsing solution. Specifically, 1 kg of recycled polyolefin resin film pieces were placed in 10 L of diethylene glycol methyl ether as the rinsing solution, and stirring was performed for 30 minutes using a three-one motor (rotation speed: 500 rpm).

[0164] (Dehydration drying process) The film fragments of recycled polyolefin resin after the wet grinding and rinsing processes were subjected to specific gravity separation in water using a water-tank specific gravity separation apparatus manufactured by Nippon Seam Co., Ltd. During this process, polypropylene and polyethylene (film fragments of recycled polyolefin resin) floated, while the other components settled. The floating film fragments were collected and centrifuged at 500 rpm to remove moisture. They were then dried at 60°C for one day.

[0165] (Melting and mixing process) A 0.3% antioxidant (Irganox 1010) was added to the recycled polyolefin resin film pieces after the wet grinding and rinsing processes. A twin-screw extruder "KZW" (L / D=45) manufactured by Technovel Co., Ltd. was used as the extrusion apparatus. With a screw rotation speed of 300 rpm, the recycled polyolefin resin film pieces after the wet grinding and rinsing processes were supplied to the twin-screw extruder at a speed of 10 kg / h and melt-kneaded to obtain a molten kneaded product. In this process, the two screws mounted on the twin-screw extruder were screws that combined the screw blocks shown in Table 3 below. These were used in the examples and comparative examples. The types and quantities of screw blocks and kneading blocks are shown in Table 3 below. Furthermore, the resin pressure was 2-3 MPa. The extruded molten mixture was then taken up as strands and also pelletized. The molten mixture temperature (measured resin temperature during extrusion) used in each example is shown in Tables 4 and 5.

[0166] [Table 3]

[0167] In Table 3 above, "BF" indicates a forward-feed full-flight screw block (forward-feed full-flight screw block 11 in Figure 5). "BR(45)" indicates a kneading block (kneading block 12R in Figure 7) that uses five kneading discs P and is assembled with a right-hand twist angle of 45° between adjacent kneading discs P. "BL(45)" indicates a kneading block (kneading block 12L in Figure 8) that uses five kneading discs P and is assembled with a left-hand twist angle of 45° between adjacent kneading discs P. "BN(90)" indicates a kneading block (kneading block 15 in Figure 6) that uses five kneading discs P and is assembled with a twist angle of 90° between adjacent kneading discs P.

[0168] The screw (a) in Table 3 consists only of a forward-feeding full-flight screw block 11 (Figure 5), and it is shown that six forward-feeding full-flight screw blocks 11 are connected in a continuous sequence from the base end to the tip end. Furthermore, the screw (b) in Table 3 shows that four forward-feeding full-flight screw blocks 11 (Figure 5) are connected in a row from the base end, and two more kneading blocks 12R (Figure 7) are connected in a row from the base end toward the tip end. Next, Table 3 shows that screw (c) has a configuration in which four forward-feed full-flight screw blocks 11 (Figure 5) are connected in a row from the base end, and two more kneading blocks 15 (Figure 6) are connected in a row from the base end toward the tip end. Furthermore, Table 3 shows that screw (d) has a configuration in which four forward-feed full-flight screw blocks 11 (Figure 5) are connected in a row from the base end, and two more kneading blocks 12L (Figure 8) are connected in a row toward the tip end. Furthermore, screw (e) in Table 3 is configured to consist of two consecutive forward-feeding full-flight screw blocks 11 (Figure 5), two consecutive kneading blocks 12R (Figure 7), and two consecutive kneading blocks 15 (Figure 6), connected in that order from the base end to the tip end. Screw (f) in Table 3 has a configuration in which two consecutive kneading blocks 12R (Figure 7), two consecutive kneading blocks 15 (Figure 6), and two consecutive kneading blocks 12L (Figure 8), connected in that order from the base end to the tip end.

[0169] (molding process) Using the obtained pellets, a 4mm thick dumbbell test piece (molded product) was produced by injection molding using a Sodick MS100 injection molding machine. The injection molding conditions were as follows: injection temperature (heating temperature) 200°C, mold temperature (cooling temperature) 40°C, indentation pressure 90 MPa, holding pressure 50 MPa, and molding time (cooling time) 30 seconds. A mold of type 1B as specified in JIS K 7139 was used.

[0170] <Measurement and Evaluation> The following measurements and evaluations were performed during the series of operations described above. The results are shown in Tables 4 to 6.

[0171] (Peelability) The area of ​​the peeled portion relative to the total surface area was measured for film pieces of recycled polyolefin resin after the wet grinding and rinsing processes. A score was assigned to each measured peeled area according to the following criteria. A higher score indicates superior peelability. 1 point... Peeling area is less than 10% 2 points... Peeling area is 10% or more but less than 50% 3 points... Peeling area is 50% or more but less than 100% 4 points... 100% of the peeling area

[0172] (Evaluation of impact resistance of molded products) The dumbbell test specimens produced in the above molding process were evaluated for notched impact strength using a Charpy impact tester manufactured by Yasuda Seiki Co., Ltd., in accordance with the method of JIS K7111. Ten measurements were taken for each level, and the average of the six points obtained by excluding the two highest and two lowest values ​​was adopted. The measurement temperature was 23°C and the humidity was 50%.

[0173] (Measurement of dispersed particle size (dispersion diameter of the functional layer) of the domain phase of the functional layer after the melting and mixing process) The dumbbell specimens prepared in the above molding process were cut at 10 locations using a microtome, and SEM backscattered electron images were observed at 15KV and 150x magnification for each cross-section, obtaining images of a 400 μm × 600 μm field of view. The particle size of the functional layer was extracted from the obtained images using the image processing software ImageJ. In this process, pixels smaller than 2 × 2 pixels were considered noise, and the diameter was calculated from the area assuming the particles were circles, and a histogram was created. Then, the maximum value of the region occupying 90% of the total area from the obtained histogram was taken as the dispersion diameter of the functional layer. Furthermore, the dispersed particle size of the domain phase derived from the functional layer in the pellet was also measured in the same manner as described above. The obtained dispersed particle size values ​​were within a ±10% variation range compared to the dispersed particle size values ​​of the domain phase of the functional layer in the dumbbell specimen, and were 10 μm or less.

[0174] (Measurement of the volume of dispersed particles in the domain phase of the functional layer after the melting and mixing process (dispersion volume of the functional layer)) The dumbbell test specimens prepared in the above molding process were cut at 10 locations using a microtome, and each cross-section was X-ray CT scanned using a Toshiba TOSCANER-32300μFD-Z2 to calculate the adhesive particle volume. A histogram was created by calculating the volume assuming the particles were circular. From the obtained histogram, the maximum value in the region occupying 90% of the total was defined as the dispersion volume of the functional layer. Furthermore, the dispersion volume of the domain phase of the functional layer in the pellet was also measured in the same manner as above. The obtained dispersion volume value was within a ±10% variation range compared to the dispersion volume of the domain phase of the functional layer in the dumbbell specimen, and was 20 μm. 3 The results were as follows:

[0175] [Table 4] In Table 4 above, the two screws used are the same. For example, in Example 1, both screws used are screw (c) from Table 3.

[0176] [Table 5] In Table 5 above, the two screws used are the same.

[0177] Tables 4 and 5 show that in the embodiments according to this disclosure, molded articles were manufactured by performing a predetermined process, and the resulting molded articles were found to have superior impact resistance compared to the comparative examples. In particular, it has been confirmed that the manufacturing method of this embodiment provides excellent impact resistance to the entire molded product by reducing the dispersion diameter and dispersion volume of the domain phase derived from the functional layer contained in the laminate, which is the raw material. For example, the following reasons can be considered. In this embodiment, the molded article has a so-called sea-island structure as its morphology, with recycled polyolefin resin as the matrix phase (sea phase) and the functional layer as the domain phase (island phase). By a predetermined method in this embodiment, the functional layer can be dispersed in the recycled polyolefin resin as finely milled particles with relatively small dispersion volume and dispersion diameter, thereby reducing unevenness in the interface area with the sea phase, such as aggregation of island phases or large island phases. As a result, even when the compatibility between the sea phase and the island phase is low, localized fracture at the interface between the island phase and the sea phase due to impact can be reduced, thus improving the impact resistance of the molded article as a whole. [Industrial applicability]

[0178] According to the present invention, it is possible to provide a method for manufacturing a molded article that allows for the recovery of recycled polyolefin resin from a laminate comprising a polyolefin film layer and a functional layer, thereby obtaining a molded article with excellent impact resistance. [Explanation of Symbols]

[0179] 1. Screw 2 Hopper 3 Cylinders (or barrels) 4 Raw materials 5 Heater 6 Dice section 7. Cooling water tank 8 Peretazer 9 Strands 10 Extruder 11 (Forward Feed) Full Flight Screw Block 12R Right-handed kneading block 12L Left-hand turning kneading block 14 (Reverse Feed) Full Flight Screw Block 15 Kneading Blocks 16-axis body 17 Axis body 20 Through holes

Claims

1. A method for manufacturing a molded article, comprising recovering recycled polyolefin resin from a laminate comprising a polyolefin film layer and a functional layer, and manufacturing a molded article using the recycled polyolefin resin, An immersion step in which the laminate is immersed in a desorption solution containing alkali, A wet crushing step is performed in which the laminated body, after immersion, is wet crushed in the presence of water to obtain film pieces containing recycled polyolefin resin. The extruder using a screw equipped with a kneading block having one or more kneading discs is kneaded at a screw rotation speed of 300 rpm or more, and the dispersion diameter of the domain phase derived from the functional layer is 10 μm or less and the dispersion volume of the domain phase derived from the functional layer is 20 μm. ３ A method for manufacturing a molded product, comprising a melt-kneading step of melt-kneading the mixture to the following state.

2. The method for manufacturing a molded article according to claim 1, wherein the kneading block is made up of two or more kneading discs connected together, and the angle between the long axes of adjacent connected kneading discs is greater than 0° and 90°.

3. The method for producing a molded article according to claim 1 or 2, wherein the functional layer is a cured product of an adhesive layer composition containing a polyol compound and a polyisocyanate compound.

4. The method for manufacturing a molded article according to claim 1 or 2, wherein the wet crushing is performed by shaking or beating.

5. A method for manufacturing a molded article according to claim 1 or 2, further comprising a molding step of molding the molten kneaded material obtained in the molten kneading step to obtain a molded article.

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