JP7318775B1 - Recycled plastic manufacturing method - Google Patents

Abstract

Kind Code: A1 The present invention provides a laminated plastic packaging material that can be efficiently and easily produced from a laminated plastic packaging material of high quality without a step of separating each layer of a plastic substrate, a printing layer, and an adhesive layer that constitute the laminated plastic packaging material. It is an object of the present invention to provide a recycled plastic manufacturing method for obtaining a recycled plastic having good moldability. A recycled plastic manufacturing method for obtaining a recycled plastic from a laminated plastic packaging material and a compatibilizer using an extrusion device equipped with a screw and a discharge part, wherein the plastic base material constituting the packaging material is: The urethane resin (A), which contains a polyolefin resin, the packaging material comprises a printed layer containing the urethane resin (A) and/or an adhesive layer containing the urethane resin (B), and is contained in the total mass of the packaging material. and the urethane resin (B) have a total mass of 0.1 to 15% by mass, and a method for producing recycled plastic, comprising a step of melting and kneading the packaging material and the compatibilizer in an extrusion device. . [Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a method for producing recycled plastic, which performs material recycling from a laminated plastic packaging material containing polyolefin resin.

Various plastic substrates such as polyester substrates, nylon substrates (NY), polypropylene substrates (PP), and polyethylene substrates (PE) are bonded together and used for food packaging packages (packaging materials). A multi-layered food packaging package, for example, is printed with printing ink on a first film substrate, and a second film substrate is attached onto the printed layer via an adhesive layer as necessary. After being combined, it is cut and heat-sealed to form the package. Food packaging packages composed of different types of base materials have high functionality, but on the other hand, there is a problem of compatibility, so material recycling is considered difficult.

On the other hand, food packaging packages discarded or dumped in the ocean as garbage have become a problem of environmental pollution, and interest in recycling has been rapidly increasing in recent years. When recycling a food packaging package, first, impurities contained in the package are removed, pulverized, alkaline treatment etc. are performed as necessary (Patent Document 1), and the washed material is melted as a raw material and made into pellets. The obtained pellets are then processed into new products. However, in the recycling method described above, most of the printed layer and adhesive layer contained in the package remain without being removed, resulting in poor quality pellets and the like.

Further, Patent Documents 2 and 3 disclose a method for producing a recycled resin composition having excellent moldability from a recycled resin containing various resins using a compatibilizer. However, there is no detailed description of a method for producing recycled resin from food pouches containing printing ink and adhesive when urethane resin and polyolefin resin are present, and printing ink, adhesive and packaging materials are not described. The compatibility with the olefin resin in the medium is unclear.

In other words, there is a demand for a method of producing good-quality recycled plastic from plastic packaging materials by simple separation, washing, and dehydration without the step of removing the printed layer and the adhesive layer.

Japanese Patent Application Laid-Open No. 2014-19003 Japanese Patent Application Laid-Open No. 2020-158698 JP 2020-158699 A

The present invention provides a laminated plastic packaging material that can be efficiently and simply molded with good quality without performing a separation step between the plastic base material constituting the laminated plastic packaging material, the printing layer, and the adhesive layer. An object of the present invention is to provide a recycled plastic production method for obtaining a recycled plastic having excellent properties.

As a result of extensive studies, the present inventors have found that the above problems can be solved by using the method for producing recycled plastic described below, and have completed the present invention.

That is, the present invention is a method for producing recycled plastic, in which a recycled plastic is obtained from a laminated plastic packaging material and a compatibilizer using an extrusion device equipped with a screw and a discharge part,
The plastic base material constituting the packaging material contains a polyolefin resin,
The packaging material comprises a printed layer containing a urethane resin (A) and/or an adhesive layer containing a urethane resin (B),
The total mass of the urethane resin (A) and the urethane resin (B) contained in the total mass of the packaging material is 0.1 to 15% by mass,
The present invention relates to a method for producing recycled plastic, including a step of melting and kneading the packaging material and the compatibilizer in an extrusion device.

The present invention also relates to the method for producing recycled plastic according to claim 1, wherein the laminated plastic packaging material contains 85% by mass or more of polyolefin resin in the total mass of the laminated plastic packaging material.

Further, according to the present invention, the laminated plastic packaging material includes an adhesive layer containing a urethane resin (B), and the urethane resin (B) has a glass transition temperature of -30°C to 30°C. It relates to the described method for manufacturing recycled plastics.

Further, in the present invention, the laminated plastic packaging material includes an adhesive layer containing a urethane resin (B), and the storage elastic modulus of the urethane resin (B) at a temperature of 150° C. and a frequency of 10 Hz is 0.01 to 10 MPa. The method for producing recycled plastic according to claim 1, which is as follows.

Further, according to the present invention, the recycled plastic according to claim 1, wherein the laminated plastic packaging material includes an adhesive layer containing a urethane resin (B), and the melting point of the urethane resin (B) is 180 to 280°C. It relates to a manufacturing method.

The present invention also relates to the method for producing recycled plastic according to claim 1, wherein the compatibilizer has a melting point of 55°C to 140°C.

The present invention also relates to the method for producing recycled plastic according to claim 1, wherein the chlorine content of the laminated plastic packaging material is 0.4% by mass or less in the total mass.

The present invention also relates to the method for producing recycled plastic according to claim 1, further comprising a drying step to reduce the moisture content of the laminated plastic packaging material to 3% by mass or less.

The present invention also relates to the method for producing recycled plastic according to claim 1, wherein the step of melting and kneading includes a step of kneading at a screw rotation speed of 50 to 900 rpm.

According to the present invention, a laminated plastic packaging material can be efficiently and simply molded with good quality without performing a separation step between the plastic base material constituting the laminated plastic packaging material, the printing layer, and the adhesive layer. It has become possible to provide a recycled plastic manufacturing method for obtaining a recycled plastic having excellent properties.

Embodiments of the present invention will be described in detail below, but the description of the embodiments or requirements described below is an example of the embodiments of the present invention, and the present invention does not exceed the gist thereof. Not limited.

In the present invention, the term "laminated plastic packaging material" may be simply referred to as "packaging material" but has the same meaning.

The manufacturing method of the present invention is a recycled plastic manufacturing method in which a recycled plastic is obtained from a laminated plastic packaging material and a compatibilizer using an extrusion device equipped with a screw and a discharge part,
The plastic base material constituting the packaging material contains a polyolefin resin,
The packaging material comprises a printed layer containing a urethane resin (A) and/or an adhesive layer containing a urethane resin (B),
The total mass of the urethane resin (A) and the urethane resin (B) contained in the total mass of the packaging material is 0.1 to 15% by mass,
It is characterized by including a step of melting and kneading the packaging material and the compatibilizer in an extrusion device.
The total mass of the urethane resin (A) and the urethane resin (B) contained in the total mass of the packaging material is 0.1 to 15% by mass, and a laminated plastic packaging material and a compatibilizer are placed in an extrusion device. By melting and kneading with , resin components such as polyolefin resin and urethane resin, which are originally incompatible, are compatible, and a recycled plastic with excellent moldability with less foreign matter derived from the printed layer and adhesive layer is obtained. be able to. The range of the total mass of the urethane resin (A) and the urethane resin (B) contained in the total mass of the packaging material is preferably 0.5 to 13% by mass, and is 0.8 to 10% by mass. is still more preferable, and 1.0 to 8.0% by mass is even more preferable. This is to achieve both a function as a packaging material and recyclability. In addition, the case where either the urethane resin (A) or the urethane resin (B) does not exist is not excluded.

<Compatibilizer>
The compatibilizer of the present invention is not particularly limited as long as it improves the compatibility between the polyolefin resin contained in the laminated plastic packaging material and the urethane resin, but it is preferably a polyolefin (modified polyolefin) having a polar group. . Polar groups include isocyanate groups, carboxy groups, carboxylic anhydride groups, carboxylic acid halide groups, amino groups, hydroxyl groups, and epoxy groups.
A polyolefin having a polar group is specifically a polyolefin modified with a compound having a polar group such as a polar monomer. Examples include modified polyolefins composed of copolymers of solids and polar monomers. The polyolefin part (the part other than the polar group of the modified polyolefin) constituting the modified polyolefin has an affinity with the polyolefin resin of the plastic base material, while the polar group constituting the modified polyolefin is used in the printing layer and the adhesive layer. It expresses affinity by reacting or interacting with the urethane resin from which it originates. Polyethylene-based copolymers and polypropylene-based copolymers are more preferred as the modified polyolefin having a polar group.

Monomers constituting the polyolefin part include ethylene, propylene and other olefin monomers. For example, as one embodiment, it may be a propylene copolymer such as a copolymer of propylene and one or more other vinyl compounds (such as α-olefin). Polyethylene includes low density polyethylene, medium density polyethylene, High-density polyethylene, ethylene-based polymers such as copolymers of ethylene and one or more other vinyl compounds, ethylene-propylene copolymers, polybutene, poly-4-methylpentene-1, and the like.

Suitable polar monomers include polar monomers such as vinyl acetate, methacrylic acid, acrylic acid, glycidyl (meth)acrylate and other acrylic monomers, maleic anhydride (including maleic acid) and other acidic monomers. Among these, vinyl acetate, acidic monomers, and acrylic monomers are more preferable from the viewpoint of improving the moldability of recycled plastics.

The compatibilizer is not limited to the following examples, but preferably includes maleic anhydride-modified polyolefin and the like. Commercially available products include Sumitomo Chemical Co., Ltd.'s "Bond First" (a copolymer of polyethylene having an epoxy group and (meth)acrylic acid), and Japan Polyethylene Co., Ltd.'s "Rex Pearl" (a polyolefin resin having an epoxy group). , NOF's "Modiper" (polyolefin resin with epoxy groups), Sanyo Chemical Industries' "Umex" (maleic anhydride-modified polypropylene), Arkema's "Orevac" (maleic anhydride-modified polyethylene), Arkema "Rotada" (polyolefin resin with acid anhydride) manufactured by Sumitomo Chemical Co., Ltd. "Bondyne" (polyolefin resin with acid anhydride) polyolefin-based resin), Dow Chemical Co.'s "Primacol" (a polyolefin-based resin having a carboxyl group), and the like.

The melting point of the compatibilizing agent is preferably 160° C. or less because the compatibilizing agent must be sufficiently melted in the process of melting and kneading the laminated plastic packaging material. Moreover, from the viewpoint of the physical properties of the recycled plastic, the melting point is preferably 40° C. or higher. It is preferably 40°C to 160°C, more preferably 50°C to 150°C, and even more preferably 55°C to 140°C. The melting point of the compatibilizing agent is a value measured with a differential scanning calorimeter (DSC).

Also, the content of the compatibilizer is preferably 0.01 to 10% by mass, more preferably 0.02 to 5.0% by mass or more, still more preferably 0.02% to 5.0% by mass, based on the total mass of the laminated plastic packaging material. 03 to 1.0% by mass. If it is 0.01% by mass or more, the polyolefin resin or urethane resin is more uniformly compatible, and if it is 10% by mass or less, it suppresses the deterioration of the mechanical properties of the recycled plastic due to the compatibilizer component, A recycled material with excellent moldability can be obtained.

<Laminated plastic packaging material>
A plastic base material that constitutes the laminated plastic packaging material comprises a polyolefin resin. The plastic substrate may be modified chemically or physically.
Further, the packaging material includes a printed layer containing the urethane resin (A) and/or an adhesive layer containing the urethane resin (B), and also includes an embodiment including either the printed layer or the adhesive layer. Further, the total mass of the urethane resin (A) and the urethane resin (B) contained in the total mass of the packaging material is 0.1 to 15% by mass.
Examples of the laminated plastic base material that constitutes the laminated plastic packaging material include a stretched plastic base material, a plastic base material having a vapor deposition layer, a non-stretched plastic base material (sealant base material), and the like. .

<Urethane resin>
In the present invention, a urethane resin means a resin having a urethane bond. The urethane resin contained in the "printing layer" is called urethane resin (A), and the urethane resin contained in the "adhesive layer" is called urethane resin (B). Urethane resins contained in the "printing layer" and the "adhesive layer" may be the same resin, but are preferably urethane resins of different embodiments. Moreover, the urethane resin (A) and the urethane resin (B) may be used alone or in combination of two or more urethane resins. Furthermore, other than the urethane bond, it may have other bonds such as an ether bond, an ester bond and a urea bond.

The configuration of the laminated plastic packaging material preferably has at least a substrate 1, a printed layer and/or an adhesive layer, and a substrate 2 in this order. It is preferable that the base material 1 is a stretched polyolefin base material and the base material 2 is a non-stretched polyolefin base material (for example, a sealant base material). Furthermore, as one embodiment, a plastic base material (intermediate base material) may be provided as an intermediate layer between the base material 1 and the base material 2 .
Specifically, the following configurations can be exemplified, but are not limited to these. Laminated plastic packaging materials are preferably laminated by known methods such as dry lamination, non-sol lamination and extrusion lamination.
In the structural representations (1) to (19) below, "/" means the boundary of each layer. In addition, even when a plurality of layers are actually laminated in contact with each other, such as the first printed layer and the second printed layer, the printed layers are collectively referred to simply as the printed layer.

(1) Substrate/printing layer/adhesive layer/sealant substrate (2) Substrate/printing layer/adhesive layer/intermediate substrate/adhesive layer/sealant substrate (3) Substrate/printing layer/adhesion Agent layer/first intermediate substrate/adhesive layer/second intermediate substrate/adhesive layer/sealant substrate (4) substrate/printing layer/AC agent layer/adhesive layer/sealant substrate (5) Substrate/Printing layer/AC agent layer/Adhesive layer/Intermediate substrate/AC agent layer/Adhesive layer/Sealant substrate (6) Substrate/Printing layer/Adhesive layer/Intermediate substrate/AC agent layer/Adhesive layer /Sealant base material (7) base material/printing layer/AC agent layer/adhesive layer/intermediate base material/adhesive layer/sealant base material (8) base material/adhesive layer/sealant base material (9) base material/ Adhesive layer/intermediate substrate/adhesive layer/sealant substrate (10) substrate/adhesive layer/first intermediate substrate/adhesive layer/second intermediate substrate/adhesive layer/sealant substrate (11) Base material/adhesive layer/intermediate base material/AC agent layer/adhesive layer/sealant base material (12) Base material/AC agent layer/adhesive layer/intermediate base material/adhesive layer/sealant base material (13) ) Printing layer/substrate/adhesive layer/sealant substrate (14) Printing layer/substrate/adhesive layer/intermediate substrate/adhesive layer/sealant substrate (15) Printing layer/substrate/adhesive layer /first intermediate substrate/adhesive layer/second intermediate substrate/adhesive layer/sealant substrate (16) printed layer/substrate/AC agent layer/adhesive layer/sealant substrate (17) printed layer /base material/AC agent layer/adhesive layer/intermediate base material/AC agent layer/adhesive layer/sealant base material (18) printed layer/base material/adhesive layer/intermediate base material/AC agent layer/adhesive layer/sealant Substrate (19) Printed layer/substrate/AC agent layer/adhesive layer/intermediate substrate/adhesive layer/sealant substrate The above-mentioned “adhesive layer” is an adhesive layer for bonding substrates together. For example, it is formed from a urethane-based adhesive used in dry lamination and non-sol lamination.
The "adhesive layer" is a hot-melt resin used in extrusion lamination, and adheres the substrates together. When the "adhesive layer" is polyolefin resin such as low-density polyethylene resin, medium-density polyethylene resin, high-density polyethylene resin, and polypropylene resin, it is regarded as polyolefin resin.
In the above structure, the "AC agent layer" represents an anchor coat agent layer, and examples of the anchor coat layer include butadiene-based, imine-based, and isocyanate-based layers. Used to improve adhesion. The "AC agent layer" may or may not be present, and the "AC agent layer" is not included in the "plastic substrate".

Since the purpose of the present invention is to produce a recycled plastic containing polyolefin resin as a main component, the laminated plastic packaging material preferably contains 85% by mass or more of the polyolefin resin in the total mass of the laminated plastic packaging material. It is more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 99% by mass or more. To obtain a molding material that has a simple separation process, high recyclability, good moldability, and can be used for various purposes by containing the polyolefin resin of the laminated plastic packaging material in the above range. can be done. The polyolefin resin is preferably polypropylene-based and/or polyethylene-based. More preferably, the polypropylene system is a copolymer of propylene and ethylene and/or butene. Further, it is more preferable that the polyolefin base materials constituting the laminated plastic packaging material are of the same type so as to be a monomaterial.

In addition, the halogen elements that are sometimes contained in laminated plastic packaging materials due to printed layers, adhesive layers, etc. generate halogen gas and hydrogen chloride, which is an acid gas, during the production of recycled plastic (also called pellets). may cause injury or endanger human health. In addition, if air bubbles are generated during pellet production, there is a possibility that compatibility of the resin will be inhibited. Therefore, the chlorine content of the laminated plastic packaging material is preferably 0.4% by mass or less, preferably 0.2% by mass or less, and 0.1% by mass or less in the total mass of the laminate. is still preferred. The chlorine content in the laminated plastic packaging material can be measured using known methods such as ion chromatography (IC) and ICP mass spectrometry (ICP-MS).

<Base material 1>
The substrate 1 contains a polyolefin resin. Further, it is more preferable to use the same (identical) material as the intermediate base material and the sealant. Materials of the same type (identical) include a combination of polypropylenes and polyethylenes.
The polyolefin resin content of the substrate is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and 80% by mass or more. It is more preferable that the content is 90% by mass or more, and it is particularly preferable that the content is 90% by mass or more.
Further, it is more preferable that the polyolefin base material is a polypropylene base material and/or a polyethylene base material, more preferably the polyolefin base material is a polypropylene base material, and the polypropylene base material is composed of propylene, ethylene and Polypropylene substrates which are copolymers with/or butene are particularly preferred.

<Intermediate base material>
The laminated plastic packaging material may further have an intermediate substrate layer. The intermediate base material contains a polyolefin resin, and is more preferably the same material as the base material 1 and the sealant base material. Furthermore, the polyolefin resin content of the intermediate base material is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and 80% by mass of the total mass. % or more, and particularly preferably 90 mass % or more. Further, the polyolefin resin is more preferably a polypropylene resin and/or a polyethylene resin, more preferably a polypropylene resin, and the polypropylene resin is propylene, ethylene and/or or a copolymer with butene is particularly preferred.
Examples of intermediate base materials include low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene-vinyl acetate copolymer, and propylene homopolymer. , polyolefin resins such as ethylene-propylene copolymers, etc., gas barrier substrates, for example, plastic substrates having an inorganic deposited layer of aluminum, silica, alumina, etc., and layers having a mixture of organic and inorganic components. A form that is a plastic substrate is preferred.

<Base material 2 (sealant base material)>
A sealant base material refers to a thermoplastic resin layer. By using a sealant base material, heat sealing is possible, and even if the surface on the sealant side comes into direct contact with the contents, it can be protected. The sealant base material is preferably the innermost layer in order to make the laminate bag-like. The sealant base material preferably contains a polyolefin resin, and is more preferably the same material as the base material 1 and the intermediate base material.
Furthermore, the polyolefin resin content of the sealant base material is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and 80% by mass. % or more, and particularly preferably 90 mass % or more.
Further, the polyolefin resin is more preferably a polypropylene resin and/or a polyethylene resin, more preferably a polypropylene resin, and the polypropylene resin is propylene, ethylene and/or or a copolymer with butene is particularly preferred.
Materials constituting the sealant include, for example, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene-vinyl acetate copolymer, and propylene. Examples include polyolefin resins such as homopolymers and ethylene-propylene copolymers, and one or more of these resins can be used. The sealant may be composed of a single layer or multiple layers of two or more layers. It should be noted that the sealant is preferably a non-stretched film made of the resin described above in order to suppress shrinkage during heat sealing.

The thickness of the sealant base material is not particularly limited, and is appropriately set according to the use of the packaging material and the type and properties of the object to be packaged. In the case of pouches (especially retort pouches), the thickness of the sealant is preferably 20-150 μm, more preferably 25-130 μm.

The sealant substrate may be, for example, a sealant having an inorganic deposition layer such as aluminum, silica, and alumina, or an organic layer such as ethylene-vinyl alcohol copolymer, polyvinyl alcohol, etc. However, in order to obtain a good quality plastic, is preferably free of inorganic deposition layers and organic layers. In addition, the sealant base material may be a multi-layer formed by a co-extrusion method.

<Print layer>
The printed layer in the present invention is a layer that displays arbitrary pictures, patterns, characters, symbols, etc. for the purpose of imparting decoration or aesthetics; displaying contents, expiration dates, manufacturers or sellers, etc. be. The printed layer may be a solid printed layer without pictures, patterns, characters, symbols, and the like. The method of forming the printed layer is not particularly limited, and it can be formed using a known colorant (pigment and/or dye), but it is preferably formed using a printing ink containing a pigment and a binder resin. Moreover, the printed layer may have a single layer structure or a multilayer structure, and may be printed on the surface layer. The thickness of the printed layer is preferably 0.1-10 μm, more preferably 0.5-5 μm, particularly preferably 1-2.5 μm.

The printed layer can be obtained by forming printing ink on the substrate by various printing methods. Although the printing method is not particularly limited, preferred examples include screen printing, gravure printing, flexographic printing, offset printing, and inkjet printing, with gravure printing being particularly preferred.

<Pigment>
The printed layer is preferably formed using a printing ink containing a pigment in addition to the urethane resin (A). Considering quality deterioration due to coloring of recycled plastic, the content of the colorant in the total mass of the printed layer is preferably 30% by mass or less, more preferably 25% by mass or less, and 23% by mass or less. It is even more preferable to have The coloring agent is preferably a pigment, and the pigment may be an organic pigment, an inorganic pigment, or an extender pigment. Examples of inorganic pigments include those containing titanium oxide, and extender pigments that include silica, Barium sulfate, kaolin, clay, calcium carbonate, magnesium carbonate and the like are preferred. Among organic pigments, it is preferable to use those composed of organic compounds and organometallic complexes. Colorants such as pigments may be used singly or in combination of two or more.

[Organic pigment]
Examples of organic pigments include, but are not limited to, soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthrone, dianthraquinonyl, anthrapyrimidine, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethineazo, flavanthrone, diketopyrrolopyrrole, isoindoline, indanthrone, carbon black, etc. pigments. Also, for example, Carmine 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmine FB, Chromophtal Yellow, Chromophtal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Quinacridone Magenta, Quinacridone Red, Indance Ron blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, daylight fluorescent pigments, and the like.

The hue of the organic pigment is preferably at least one selected from the group consisting of black pigments, indigo pigments, green pigments, red pigments, purple pigments, yellow pigments, orange pigments and brown pigments. Furthermore, at least one or two or more selected from the group consisting of black pigments, indigo pigments, red pigments, and yellow pigments are preferred. Specific examples of organic pigments include C.I. I. Indicate by number. Preferably C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 48:2, C.I. I. Pigment Red 48:3, C.I. I. Pigment Red 146, C.I. I. Pigment Red 242, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 14, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 13, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 139, C.I. I. Pigment Red 185, C.I. I. Pigment Red 122, C.I. I. Pigment Red 178, C.I. I. Pigment Red 149, C.I. I. Pigment Red 144, C.I. I. Pigment Red 166, C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 37, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:1, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 15:4, C.I. I. Pigment Blue 15:6, C.I. I. Pigment Green 7, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 64, C.I. I. Pigment Black 7.

[Inorganic pigment]
Inorganic pigments include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, aluminum particles, mica (mica), bronze powder, chromium vermillion, yellow lead, cadmium yellow, cadmium red, and ultramarine blue. , Prussian blue, red iron oxide, yellow iron oxide, iron black, titanium oxide, zinc oxide, etc. Aluminum is available in leafing type and non-leafing type, but non-leafing type is preferred.

<Urethane resin (A)>
The urethane resin (A) is a urethane resin that functions as a binding resin (binder resin) in the printed layer of the laminated plastic packaging material. The urethane resin (A) is preferably a thermoplastic resin soluble in an organic solvent and contains at least the urethane resin (A). The urethane resin (A) used in the binder resin preferably has a glass transition temperature of -60°C or more and less than 40°C, more preferably -50°C to 0°C. In the present invention, the glass transition temperature of the urethane resin (A) is a value measured with a differential scanning calorimeter (DSC).

The method for producing the urethane resin (A) is not particularly limited, and it can be produced appropriately by a known method. A urethane resin composed of a polyol and a polyisocyanate, a urethane resin obtained by reacting an isocyanate-terminated urethane prepolymer composed of a polyol and a polyisocyanate with a polyamine, and the like are preferable. Examples of the manufacturing method include the method described in JP-A-2013-256551.

In addition to the urethane resin (A), examples of the binder resin that can be contained in the print layer are not limited to the following, but are cellulose-based resins, polyamide resins, rosin-based resins, and ethylene-vinyl acetate copolymer resins. , vinyl chloride-vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, styrene resin, dammar resin, styrene-maleic acid copolymer resin, polyester resin, alkyd resin, terpene resin, phenol-modified terpene resin, ketone resin, ring rubber, butyral, polyacetal resin, petroleum resin, modified resins thereof, and the like. These resins can be mixed and used.

In addition, the binder resin preferably has a chlorine content of 5% by mass or less, more preferably 4% by mass or less, in consideration of the generation of halogen gas and hydrogen chloride during pellet production. It is preferably 3% by mass or less, and particularly preferably 2% by mass or less. It also includes the case where it is 0.
When the chlorine content of the binder resin is 5% by mass or less, the environmental safety is excellent and free chlorine is less likely to occur. The above chlorine content is the content of chlorine atoms (% by mass) based on the mass of the binder resin.

The chlorine content can be measured using known methods such as ion chromatography (IC) and ICP mass spectrometer (ICP-MS). Examples of measuring instruments include LC-20ADsp manufactured by Shimadzu Corporation for IC and Agilent 7700x manufactured by Agilent Technologies for ICP-MS.
Further, the chlorine content of the printed layer can be easily calculated from the chlorine content of each raw material constituting the printed layer by the following formula. The same applies to other layers.
Formula: chlorine content (%) in the total mass of resin solids in the printing layer = mass of chlorine in the total mass of resin solids in the printing layer / total solid mass (%) in the printing layer
Formula: Chlorine content (%) in the total mass of solid content in the printing layer = mass of chlorine in the total mass of solid content in the printing layer / total mass of solid content in the printing layer (%)

In the present invention, the chlorine content is preferably measured according to JISK0127 (2013). In this measurement method, a sample pretreated by the combustion method is quantified by the ion chromatography method.

<Adhesive layer>
The adhesive layer in the present invention is a layer that adheres each layer (also referred to as a laminate), and particularly refers to a layer formed by a dry lamination method or a non-sol lamination method. When forming an adhesive layer by a dry lamination method or a non-sol lamination method, a two-liquid type urethane adhesive composed of a polyol as a main agent and a polyisocyanate as a curing agent is preferred. In this case, the adhesive layer is formed of urethane resin (B), which is a cured product of this two-liquid type urethane adhesive. The polyol may be any compound having two or more hydroxyl groups, and can be selected from known polyols. Examples of polyols include polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyether polyols, polyolefin polyols, acrylic polyols, silicone polyols, castor oil-based polyols, and fluorine-based polyols. Among them, it is preferable to contain polyether polyol and/or polyester polyol. The polyol may be an acid-modified product in which some of the hydroxyl groups in the polyol have been acid-modified, or may be one in which some of the hydroxyl groups in the polyol are reacted with diisocyanate to introduce urethane bonds. The polyisocyanate may be any compound having two or more isocyanate groups, and can be selected from known polyisocyanates. Polyisocyanates include, for example, aromatic polyisocyanates, araliphatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, and modified products thereof. Polyols may be used alone or in combination of two or more. The same applies to polyisocyanates.
In addition, the adhesive layer can use additives described later as other components.

The glass transition temperature of the urethane resin (B) is preferably -30°C to 30°C, more preferably -20°C to 20°C, even more preferably -15°C to 15°C, from the viewpoint of adhesion to the substrate.
Further, the storage elastic modulus at 150° C. and a frequency of 10 Hz is preferably 0.01 to 10 MPa, more preferably 0.05 to 5 MPa, even more preferably 0.1 to 1 MPa. A polyurethane resin (B) having a storage elastic modulus of 10 MPa or less at 150° C. and a frequency of 10 Hz is likely to be melted and kneaded by the shear stress of the screw of the extruder. Therefore, the compatibility with the polyolefin resin and the compatibilizer is improved during melting and kneading. The polyurethane resin (B) can have various molecular structures depending on the structure of the adhesive used and the reaction conditions of the adhesive, so the molecular structure is not limited, but the storage elastic modulus is 10 MPa or less. It can be said that the polyurethane resin (B) at the melting temperature has flexibility and high compatibility. Moreover, if the storage elastic modulus is 0.01 or more, it has functions as an adhesive such as heat resistance and adhesion to a substrate.
The melting point of the urethane resin is preferably 180 to 280°C, more preferably 190 to 270°C, even more preferably 200 to 260°C. When it is within the above range, it is easier to knead in the extruder, and a uniform recycled plastic with less foreign matter can be obtained. The melting point and glass transition temperature of the urethane resin (B) are values measured by a differential scanning calorimeter (DSC). be.

[Other ingredients]
The adhesive layer contains silane coupling agents, phosphorus oxyacids or derivatives thereof, leveling agents, antifoaming agents, reaction accelerators, inorganic fillers (for example, silica, alumina, mica, talc, aluminum flakes, glass flakes, etc.). ), layered inorganic compounds, stabilizers (e.g., antioxidants, heat stabilizers, ultraviolet absorbers, hydrolysis inhibitors), rust inhibitors, thickeners, plasticizers, antistatic agents, lubricants, antiblocking agents, It may contain a coloring agent, a filler, a crystal nucleating agent, a catalyst for adjusting the curing reaction, and the like.

<Adhesive layer>
As a layer for adhering each layer, an adhesive layer can be used in addition to the adhesive layer.
The adhesive layer in the present invention is suitably exemplified by a thermoplastic resin formed by an extrusion lamination method. The thermoplastic resin formed by the extrusion lamination method is preferably a polyolefin resin, and more preferably the same (identical) material as the base material 1, the intermediate base material, and the sealant base material. In addition, an imine-based anchor coating agent, a butadiene-based anchor coating agent, and other anchor coating agents can be used to improve the adhesiveness between the base material 1 or the printed layer and the adhesive layer.

<Recycled plastic manufacturing method>
For example, the following embodiments are preferable for the recycled plastic manufacturing method of the present invention.
In one embodiment, the laminated plastic packaging material is preferably in a fragmented shape by cutting or crushing. A method such as cutting or crushing is used for fragmentation.
Moreover, the laminated plastic packaging material is preferably washed, and in the present invention, preferably has a washing step. It is preferable that the laminated plastic packaging material is further dehydrated and dried. After that, the laminated plastic packaging material is processed to obtain recycled plastic. Processing includes heat melting and kneading and extrusion (discharging), which will be described in detail below.

<Cut or crush>
Cutting or crushing is effective for fragmenting the shape of the laminated plastic packaging material. The cutting or crushing method is not particularly limited, and examples thereof include methods using a jaw crusher, impact crusher, cutter mill, stamp mill, ring mill, roller mill, jet mill, or hammer mill. The size of the piece of the laminated plastic packaging material preferably has a side length of 1 mm to 50 mm, more preferably 3 mm to 40 mm, even more preferably 5 mm to 30 mm. Fragmentation of the shape of the laminated plastic packaging into 1 to 50 mm sizes increases the efficiency of the washing, dehydration, and drying processes by increasing the surface area, and promotes the homogenization of the molten resin, resulting in high-quality recycled plastics. .

<Washing>
The laminated plastic packaging material is preferably washed. The cleaning method may be batch type or continuous type, and may use water, detergent, neutralizer, or alkaline aqueous solution.
Further, it is more preferable that the washed laminated plastic packaging material is dehydrated and dried. A centrifugal dehydration method is suitable as a dehydration method, and a hot air drying method is suitable as a drying method. The purpose of adjusting the moisture content of the laminated plastic packaging material by dehydration and drying is to avoid foaming during pellet production. If air bubbles are generated during pellet production, the pressure in the cylinder will change, the extrusion rate and extrusion pressure will not be constant, and there is a risk that the shape and dimensions of the pellets will become irregular. In addition, when a molded article is produced using the produced pellets, irregularities are likely to occur on the surface, and the surface condition of the molded article may deteriorate.
The water content in the printed matter or laminate (A) is preferably 3% by mass or less, more preferably 2% by mass or less, still more preferably 1% by mass or less, based on the total mass of the printed matter or laminate (A), and 0.5 mass % or less is particularly preferred.

<Processing>
The laminated plastic packaging material that has been fragmented or washed and dried is heat-melted and kneaded together with a compatibilizing agent in an extruder equipped with a screw to form a resin composition (a). When the resin composition (a) is cooled to 40° C. or lower, it becomes a recycled plastic.

Specific steps for obtaining recycled plastic include a step of supplying a laminated plastic packaging material and a compatibilizer from a supply port, and melting and kneading the laminated plastic packaging material and the compatibilizer supplied from the supply port. A step of forming a resin composition (a), a step of discharging the resin composition (a) melted and kneaded in the melt-kneading section, and cooling and regenerating the resin composition (a) discharged from the discharge section. obtaining the plastic. The shape of the recycled plastic is not particularly limited, and includes rod-like, particulate, cubic, rectangular parallelepiped, irregular shapes, and the like.

The laminated plastic packaging material and the compatibilizing agent are heated and melted at 150 to 270° C. and further kneaded to form a resin composition (a). Regarding the temperature range in this process, it is necessary to consider the glass transition temperature and melting temperature of the laminated plastic packaging material, the shape of the recycled plastic, and the pressure applied during the molding process. The melting temperature is preferably 160°C to 260°C, more preferably 170°C to 250°C, and even more preferably 180°C to 240°C. It is heated and melted in this temperature range and kneaded to form a uniform recycled plastic.
The rotation speed of the screw during kneading is 50 to 900 rpm, preferably 80 to 800 rpm, more preferably 100 to 700 rpm, still more preferably 150 to 600 rpm.
When the speed is 50 rpm or more, a sufficient shear stress is applied to the printed matter or laminate (A), the resin composition (a) and further the recycled plastic are made more uniform, and the generation of insoluble matter can be suppressed. If the speed is 900 rpm or less, it is possible to suppress the occurrence of scorch due to the shear heat of the resin. As a result, good appearance and moldability can be maintained.

In the step of obtaining the recycled plastic by discharging the resin composition (a), the resin pressure at the tip discharge part of the extrusion device is preferably 18 MPa or less, more preferably 15 MPa, and still more preferably 10 MPa. Due to the pressure, impurities are less likely to be contained, and recycled plastics with stable purity can be obtained continuously. Discharge pressure is affected by processing temperature, screw rotation speed, discharge rate, resin viscosity, screen mesh (metal net) used to remove foreign matter from pellets to be molded, and the like. In addition, clogging of the mesh with insoluble matter and foreign matter, foaming caused by moisture and chlorine-containing substances, etc., also cause changes in pressure. If the pressure is less than this pressure, it is possible to suppress the spread of the screen mesh (metal net) due to the pressure, and it becomes difficult for impurities to pass through, so it is possible to continuously obtain recycled plastics with stable purity.
Also in the present invention, it is preferable to use a screen mesh (metal net), and the type of screen mesh (metal net) is not particularly limited. Examples thereof include plain weave, twill weave, plain dutch weave and twilled tatami weave, and punching metal types, with plain weave being preferred. The size of the screen mesh is preferably 40 mesh or more, more preferably 80 mesh or more, still more preferably 120 mesh or more, in consideration of the pressure of the discharge part and clogging.

Examples of the method for cooling and shredding the discharged resin composition (a) to obtain a recycled plastic include a hot cut method and a strand cut method, but are not particularly limited.

Cooling methods include, for example, air cooling, wind cooling, and water cooling. In the present invention, it is preferable to include a water cooling step. Cooling to 20°C to 80°C is preferable, and cooling to 30°C to 60°C is more preferable.

In addition, the laminated plastic packaging material may be processed by an extrusion device after adding various additives, if necessary. Mixing of the cut or crushed material with optional ingredients can be performed using a Henschel mixer, a tumbler, a disper, or the like.

<Molded product>
The recycled plastic obtained by the manufacturing method described above can be used as a molding material, for example, and can be heat-molded to obtain a molded product. The thermoforming method is not particularly limited, and examples thereof include injection molding, extrusion molding, blow molding, and compression molding.
The molding material produced using the recycled plastic of the present invention has a high quality because the printed layer is detached and the reattachment of the detached component is suppressed. , toys, sporting goods, medical materials, construction materials, and so on.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. Parts and % in the present invention represent parts by mass and % by mass unless otherwise specified.

<Hydroxyl value>
The hydroxyl value is the number of mg of potassium hydroxide required to neutralize the acetic acid bound to the hydroxyl group when 1 g of the sample is acetylated, and was measured by the method described in JIS K 0070.

<Acid value>
The acid value is mg of potassium hydroxide required to neutralize free fatty acid, resin acid, etc. contained in 1 g of sample, and was measured by the method described in JIS K 0070.

<Amine value>
The amine value is the number of mg of potassium hydroxide equivalent to the equivalent of hydrochloric acid required to neutralize the amino groups contained in 1 g of the sample, and was measured according to JIS K 0070. That is, 0.5 to 2 g of the sample was accurately weighed (sample solid content: Sg). 50 mL of a mixed solution of methanol/methyl ethyl ketone=60/40 (mass ratio) was added to the accurately weighed sample to dissolve the sample. Bromophenol blue was added to the resulting solution as an indicator, and the resulting solution was titrated with a 0.2 mol/L ethanolic hydrochloric acid solution (potency: f). The point at which the color of the solution changed from green to yellow was defined as the end point, and the titration amount (AmL) at this time was used to determine the amine value by the following formula.
(Formula) Amine value = (A x f x 0.2 x 56.108) / S [mgKOH/g]

<Weight average molecular weight>
The weight-average molecular weight was obtained by measuring the molecular weight distribution using a gel permeation chromatography (GPC) device (HLC-8220 manufactured by Tosoh Corporation) and obtaining the converted molecular weight using polystyrene as a standard substance. Measurement conditions are shown below.
Column: The following columns were connected in series and used.
TSKgelSuperAW2500 manufactured by Tosoh Corporation
TSKgelSuperAW3000 manufactured by Tosoh Corporation
TSKgelSuperAW4000 manufactured by Tosoh Corporation
TSK gelguard column Super AWH manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Measurement conditions: Column temperature 40°C
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min

<Chlorine content>
The chlorine content was measured according to JIS K0127 (2013). That is, a coating film was formed by applying ink or a binder resin on a transparent substrate so as to have a thickness of 2.0 μm. Dried at 80° C. and scraped off 0.5 g. The scraped coating film was subjected to pretreatment by a combustion method, and the chlorine content of the obtained sample was quantified by ion chromatography to determine the chlorine content.

<Melting point, glass transition point (Tg)>
Melting points and glass transition points were determined by differential scanning calorimetry measurements (DSC). The measurement was performed using a DSC8231 manufactured by Rigaku Corporation under the conditions of a measurement temperature range of -70 to 280°C and a heating rate of 10°C/min. The midpoint (inflection point) of the baseline shift based on the peak in the DSC curve was defined as the melting point and the glass transition point, respectively.

<Water content measurement method>
The moisture content of the dried pulverized packaging material was measured according to JIS K 0068 (2001). Measuring instruments and reagents are shown below.
Measuring instrument: Karl Fischer moisture meter MKC-710D (manufactured by Kyoto Electronics Industry Co., Ltd.)
: Moisture vaporizer ADP-611 (manufactured by Kyoto Electronics Industry Co., Ltd.)
Karl Fischer reagent: Chem Aqua water standard 1 (manufactured by Kyoto Electronics Industry Co., Ltd.)

<Dynamic viscoelasticity measurement method>
The adhesive and the adhesive solution were applied to a release film so that the dry film thickness was 100 μm, dried, allowed to stand at 40° C., and cured to prepare a urethane resin (B) film.
This urethane resin (B) film was peeled off from the release film and cut into a rectangular shape suitable for dynamic viscoelasticity measurement. For this urethane resin (B), using a dynamic viscoelasticity measuring device (manufactured by IT Keisoku Co., Ltd., product name "DVA-200"), tensile mode, frequency 10 Hz, temperature -50 to 300 ° C., heating rate Dynamic viscoelasticity was measured under conditions of 5°C/min. A graph showing the temperature dependence of the storage modulus (E') obtained by this measurement (the horizontal axis is the temperature) was created. Then, the storage modulus E' (MPa) at 150°C was recorded.

<Synthesis of urethane resin (A)>
(Synthesis Example 1) Urethane resin A1
100 parts of a polyester polyol having a number average molecular weight of 2,000 (hereinafter “MPD/SA”), which is a condensate of 3-methyl 1,5 pentanediol (MPD) and sebacic acid (SA), 1,4-butanediol ( 1 part of “1,4-BD” hereinafter), 28.5 parts of isophorone diisocyanate (hereinafter “IPDI”) and 32.1 parts of ethyl acetate are mixed and reacted at 90° C. for 5 hours under a nitrogen atmosphere to A urethane prepolymer of isocyanate was obtained. Then, isophoronediamine (hereinafter "IPDA") 11.0 parts, N-(2-aminoethyl)ethanolamine (hereinafter "AEA") 1.0 parts, dibutylamine (hereinafter "DBA") 1.0 parts and mixed 298.1 parts of solvent 1 (ethyl acetate/isopropanol = 70/30 (mass ratio)) were stirred and mixed, and the obtained urethane prepolymer having terminal isocyanate was gradually added at 40°C.
A reaction was carried out at 80° C. for 1 hour to obtain a solution of urethane resin A1 having a solid content of 30% by mass, an amine value of 6.5 mgKOH/g, a hydroxyl value of 3.8 mgKOH/g and a weight average molecular weight of 50,000. The chlorine content of urethane resin A1 is 0% by mass.

In the following ink preparation examples, the following were used.
PVB solution: Polyvinyl butyral resin having vinyl alcohol units, vinyl acetate units and vinyl butyral units and containing 73% by mass of butyral ring groups (glass transition point 70°C, weight average molecular weight 50,000, chlorine content 0% by mass) , nitrification degree 0 mass%) solid content 30% solution in ethyl acetate / isopropanol = 1/1 mixed solvent Vinyl chloride-vinyl acetate solution: vinyl chloride-vinyl acetate copolymer resin (manufactured by Nissin Chemical Co., Ltd. Solbin TA3, chlorine 30% solid content ethyl acetate solution with a content of 47.1% by mass and a degree of nitrification of 0% by mass

<Ink preparation>
[Gravure ink preparation example 1] Gravure ink I1
40 parts of urethane resin A1 solution, 15 parts of polyvinyl butyral resin (PVB) solution, C.I. I. Pigment Blue 15:3 (manufactured by Toyocolor Co., Ltd., product name: LIONOL BLUE FG-7330, chlorine content 0% by mass, degree of nitrification 0% by mass) 5 parts, silica particles (hydrophilic silica, average particle size 3.0 μm, 0.8 parts of specific surface area of 300 m ² /g) and 36 parts of mixed solvent 2 (n-propyl acetate/isopropanol = 70/30 (mass ratio)) were mixed and dispersed in a bead mill for 20 minutes to obtain a pigment dispersion. . To the resulting pigment dispersion, 0.8 parts of chlorinated polypropylene solution, 3.5 parts of propylene glycol monomethyl ether (boiling point: 121.0°C), and 1.5 parts of water were stirred and mixed to prepare organic solvent-based gravure ink I1. got

[Gravure ink preparation example 2] Gravure ink I2
40 parts of urethane resin A1 solution, 15 parts of vinyl chloride-vinyl acetate solution (PVC) solution, C.I. I. Pigment Blue 15:3 (manufactured by Toyocolor Co., Ltd., product name: LIONOL BLUE FG-7330, chlorine content 0% by mass, degree of nitrification 0% by mass) 5 parts, silica particles (hydrophilic silica, average particle size 3.0 μm, 0.8 parts of specific surface area of 300 m ² /g) and 36 parts of mixed solvent 2 (n-propyl acetate/isopropanol = 70/30 (mass ratio)) were mixed and dispersed in a bead mill for 20 minutes to obtain a pigment dispersion. . 0.8 parts of a chlorinated polypropylene solution, 3.5 parts of propylene glycol monomethyl ether (boiling point: 121.0° C.), and 1.5 parts of water were stirred and mixed with the resulting pigment dispersion to prepare organic solvent-based gravure ink I2. got

<Manufacture of adhesive>
[Polyol Production Example 1] (Polyol Solution C1)
40 parts of bifunctional polypropylene glycol having a number average molecular weight of about 2,000 and 30 parts of bifunctional polypropylene glycol having a number average molecular weight of about 400 were added to a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping tank and nitrogen gas inlet tube. 10 parts of a trifunctional polypropylene glycol having a number average molecular weight of about 400, 20 parts of a bifunctional polyether polyol ECOPROL 2000 having a number average molecular weight of about 2000, and 26 parts of tolylene diisocyanate were charged, and the mixture was stirred under a nitrogen gas stream to 80 to 80 parts. A urethanization reaction was carried out by heating at 90° C. for 5 hours. During the urethanization reaction, 0.1% of dibutyltin dilaurate (DBTDL) was added as a reaction catalyst to accelerate the reaction to obtain a polyether urethane polyol. The obtained polyether urethane polyol was adjusted to a solid content concentration of 75% with ethyl acetate to obtain a polyol solution C1.

[Polyol Production Example 2] (Polyol Solution C2)
188 parts of ethylene glycol, 316 parts of neopentyl glycol, 179 parts of 1,6-hexanediol, 315 parts of terephthalic acid and isophthalic acid were added to a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping tank and nitrogen gas inlet tube. 315 parts of acid, 64 parts of adipic acid, and 323 parts of sebacic acid were charged, and the temperature was raised to 250° C. while stirring under a nitrogen stream to carry out an esterification reaction. A predetermined amount of water was distilled, the pressure was gradually reduced, and deglycol reaction was performed at 1 mmHg or less for 5 hours to obtain a polyester polyol. After that, 7.0 parts of isophorone diisocyanate was gradually added and reacted at 150° C. for about 2 hours to obtain a polyester polyurethane polyol. 0.4 parts of trimellitic anhydride was added to 100 parts of this polyester polyurethane polyol, reacted at 180° C. for about 2 hours, and then diluted with ethyl acetate to a solid content concentration of 50%, resulting in an acid value of 2.2 mg KOH. /g of a polyol solution C2 containing partially acid-modified polyester polyol was obtained.

[Polyol Production Example 3] (Polyol Solution C3)
188 parts of ethylene glycol, 316 parts of neopentyl glycol, 179 parts of 1,6-hexanediol, 315 parts of terephthalic acid and isophthalic acid were added to a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping tank and nitrogen gas inlet tube. 315 parts of acid, 64 parts of adipic acid, and 323 parts of sebacic acid were charged, and the temperature was raised to 250° C. while stirring under a nitrogen stream to carry out an esterification reaction. A predetermined amount of water was distilled, the pressure was gradually reduced, and deglycol reaction was carried out at 1 mmHg or less for 8 hours to obtain a polyester polyol. After that, 9.0 parts of isophorone diisocyanate was gradually added and reacted at 150° C. for about 2 hours to obtain a polyester polyurethane polyol. 0.4 parts of trimellitic anhydride was added to 100 parts of this polyester polyurethane polyol, reacted at 180° C. for about 2 hours, and then diluted with ethyl acetate until the solid content concentration reached 50%, resulting in an acid value of 2.0 mg KOH. /g of polyol solution C3 containing partially acid-modified polyester polyol was obtained.

[Polyol Production Example 4] (Polyol C4)
84.4 parts of triol having a number average molecular weight of about 400 obtained by adding polypropylene glycol to glycerin and 6.9 parts of trimethylolpropane were placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank and a nitrogen gas inlet tube. , 207.7 parts of polypropylene glycol with a number average molecular weight of about 2,000, 235.4 parts of polypropylene glycol with a number average molecular weight of about 400, 205.4 parts of polytetramethylene glycol with a number average molecular weight of about 2,000, tolylene diisocyanate 60 .2 parts were charged and heated at 80° C. to 90° C. for 3 hours while stirring under a nitrogen gas stream to carry out a urethanization reaction to obtain a polyol C4 having a urethane bond.

[Polyisocyanate Production Example 1] (Polyisocyanate solution D1)
23 parts of bifunctional polypropylene glycol having a number average molecular weight of about 2,000 and 18 parts of bifunctional polypropylene glycol having a number average molecular weight of about 400 were added to a reaction vessel equipped with a stirrer, temperature system, reflux condenser, dropping tank and nitrogen gas inlet tube. parts, 2 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 30 parts of 4,4′-diphenylmethane diisocyanate are charged into a reaction vessel, and heated at 70 to 80° C. for 7 hours while stirring under a nitrogen gas stream to form urethane. reacted. After completion of the reaction, 7 parts of trimethylolpropane adduct of tolylene diisocyanate were mixed. Thereafter, the mixture was diluted with ethyl acetate to a solid content concentration of 75% to obtain a polyisocyanate solution containing polyether urethane polyisocyanate. 80 parts of the above polyisocyanate solution and 20 parts of Desmodur L75 (manufactured by Sumika Covestro Urethane Co., Ltd., trimethylolpropane adduct of toluene diisocyanate, NCO group content of 13%, solid content concentration of 75%) were mixed. It was designated as isocyanate solution D1.

[Polyisocyanate Production Example 2] (Polyisocyanate solution D2)
Coronate 2785 (a biuret-type polyisocyanate derived from hexamethylene diisocyanate, manufactured by Tosoh Corporation) was diluted with ethyl acetate to a solid concentration of 50% to obtain a polyisocyanate solution D2.

[Polyisocyanate Production Example 3] (Polyisocyanate D3)
A mixture of 2,4-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate (mass ratio 50:50) was placed in a reaction vessel equipped with a stirrer, temperature system, reflux condenser, dropping tank and nitrogen gas inlet tube, and 371.0. 27.4 parts of triol obtained by adding polypropylene glycol to glycerin and having a number average molecular weight of about 400; 2.6 parts of trimethylolpropane; 31.8 parts of polypropylene glycol having a number average molecular weight of about 400; 289.4 parts of polypropylene glycol and 77.8 parts of polytetramethylene glycol having a number average molecular weight of about 1,000 are charged, and the mixture is heated at 80°C to 90°C for 3 hours while stirring under a nitrogen gas stream to carry out a urethanization reaction. A polyisocyanate D3 having urethane bonds and having an isocyanate group content of 11.1% was obtained.

<Adhesive adjustment>
[Adhesive Preparation Example 1] (Adhesive R1)
100 parts of polyol solution C1 and 100 parts of polyisocyanate solution D1 were blended, and EA was added to obtain adhesive R1 having a solid concentration of 30%.

[Adhesive Preparation Example 2] (Adhesive R2)
100 parts of the polyol solution C1 and 150 parts of the polyisocyanate solution D1 were blended, and EA was added to obtain an adhesive R2 having a solid concentration of 30%.

[Adhesive Preparation Example 3] (Adhesive R3)
100 parts of polyol solution C2 and 8 parts of polyisocyanate solution D2 were blended, and EA was added to obtain adhesive R3 having a solid concentration of 30%.

[Adhesive Preparation Example 4] (Adhesive R4)
100 parts of polyol solution C3 and 10 parts of polyisocyanate solution D2 were blended, and EA was added to obtain adhesive R4 having a solid concentration of 30%.

[Adhesive Preparation Example 5] (Adhesive R5)
50 parts of polyol C4 and 100 parts of polyisocyanate D3 were blended to obtain adhesive R5.

<Manufacturing of laminated plastic packaging materials>
(Manufacture of packaging material P1)
Using a dry laminating machine, apply adhesive R1 to the corona-treated surface of a corona-treated biaxially oriented polypropylene (OPP) film (thickness 20 μm), dry the solvent in an oven, and then apply a line speed A non-stretched polypropylene (CPP) film (thickness: 30 μm) was laminated at 100 m/min and kept at 40° C. for 3 days to obtain a laminate P1 having an OPP/adhesive layer/CPP structure. The coating amount of the adhesive layer after drying was 2.5 g/m ² .
Table 1 shows the mass % of the polyolefin resin, the total mass % of the urethane resin (A) and the urethane resin (B), and the chlorine content (mass %) in the total mass of the packaging material.

(Manufacture of packaging material P2)
A laminate P2 having an OPP/adhesive layer/CPP structure was obtained in the same manner as the packaging material P1, except that the sealant base material was changed to an unstretched polypropylene (CPP) film (thickness: 60 μm). The coating amount of the adhesive layer after drying was 2.5 g/m ² .

(Manufacture of packaging material P3)
A laminate P3 having an OPP/adhesive layer/CPP structure was obtained in the same manner as in the manufacturing process of the packaging material P1, except that the coating amount of the adhesive was changed to 5.0 g/m ² .

(Manufacture of packaging material P4)
A laminate P4 having an OPP/adhesive layer/CPP structure was obtained in the same manner as the manufacturing process of the packaging material P1, except that the adhesive R1 was changed to the adhesive R2.

(Manufacture of packaging material P5)
A laminate P5 having an OPP/adhesive layer/CPP structure was obtained in the same manner as the manufacturing process of the packaging material P1, except that the adhesive R1 was changed to the adhesive R3.

(Manufacture of packaging material P6)
A laminate P6 having an OPP/adhesive layer/CPP structure was obtained in the same manner as the manufacturing process of the packaging material P1, except that the adhesive R1 was changed to the adhesive R4.

(Manufacture of packaging material P7)
Adhesive R5 was applied to the corona-treated surface of a corona-treated biaxially oriented polypropylene (OPP) film (thickness: 20 μm) using a non-sol laminating machine, and adhesive R5 was applied thereon at a line speed of 100 m/min. A oriented polypropylene (CPP) film (thickness: 30 μm) was laminated and kept at 40° C. for 3 days to obtain a laminate P7 having an OPP/adhesive layer/CPP structure. The coating amount of the adhesive layer was 2.0 g/m ² .

(Manufacture of packaging material P8)
Except for changing the front base material (base material 1) to a linear low density polyethylene (LLDPE) film (thickness 20 μm) and the sealant base material (base material 2) to a linear low density polyethylene (LLDPE) film (thickness 40 μm), A laminate P8 having a structure of LLDPE/adhesive layer/LLDPE was obtained in the same manner as the manufacturing process of the packaging material P1.

(Manufacture of packaging material P9)
Printing ink I1 was diluted with a mixed solvent of ethyl acetate/isopropyl alcohol (mass ratio 70/30) to Zahn cup #3 (manufactured by Rigosha) for 14.5 seconds (25°C). After that, a corona-treated oriented polypropylene (OPP) film (thickness 20 μm) is printed in this order by a gravure printing machine equipped with a gravure plate with a plate depth of 35 μm, dried at 50 ° C., OPP substrate / printing layer got Next, using a dry laminator, the printed layer of this laminate is coated with an adhesive R1, and after drying the solvent in an oven, unstretched polypropylene ( CPP) film (thickness: 30 μm) was laminated and kept at 40° C. for 3 days to obtain a packaging material P9 having an OPP substrate/printing layer/adhesive layer/CPP substrate configuration. The coating amount of the printed layer after drying was 2.0 g/m 2 , and the coating amount of the adhesive layer after drying was 2.5 g/m ² .

(Manufacture of packaging material P10)
A packaging material P10 having an OPP substrate/printing layer/adhesive layer/CPP substrate structure was obtained in the same manner as the manufacturing process of the packaging material P9, except that the printing ink I1 was changed to the printing ink I2.

(Manufacture of packaging material P11)
Printing ink I1 was printed on a corona-treated oriented polypropylene (OPP) film (thickness: 20 μm) in the same manner as in the printing process in the manufacturing process of packaging material P9 to obtain an OPP substrate/printed layer. Next, using a non-sol laminating machine, the printed layer of this laminate is coated with an adhesive R5, and a non-stretched polypropylene (CPP) film (thickness 30 μm) is laminated at a line speed of 100 m / min, It was kept at 40° C. for 3 days to obtain a packaging material P11 having a configuration of OPP substrate/printing layer/adhesive layer/CPP substrate. The coating amount of the printed layer and the adhesive after drying was 2.0 g/m ² .

(Manufacture of packaging material P12)
An OPP/printed layer was obtained in the same procedure as the printing process in the manufacturing process of the packaging material P9. Next, using an extrusion laminator, a polyethyleneimine anchor coating agent (EL-420 manufactured by Toyo-Morton Co., Ltd.) is diluted with a solvent consisting of methanol:water=70:30 (mass ratio) on the printed layer of this laminate. A solution of 1% solid content (weight ratio, methanol / water = 70/30) was applied, and after drying the solvent in an oven, a polypropylene resin (Novatec FL02A, Japan Polypropylene Co., Ltd.) melted at 330 ° C. was applied to the coated surface. (thickness: 15 μm), and at the same time, a non-stretched polypropylene (CPP) film (thickness: 30 μm) is laminated to create an OPP/printing layer/AC agent/PP resin layer/CPP base structure. A packaging material P12 was obtained. The coating amount of the printed layer after drying was 2.0 g/m ² .

(Manufacture of packaging material P13)
Packaging except that the front base material (base material 1) was changed to a linear low density polyethylene (LLDPE) film (thickness 20 μm) and the sealant base material (base material 2) was changed to a linear low density polyethylene (LLDPE) film (40 μm) A laminate P13 having a structure of LLDPE/adhesive layer/LLDPE was obtained in the same manner as in the manufacturing process of the material P9.

(Manufacture of packaging material P14)
Printing ink I1 was diluted with a mixed solvent of ethyl acetate/isopropyl alcohol (mass ratio 70/30) to Zahn cup #3 (manufactured by Rigosha) for 14.5 seconds (25°C). After that, a corona-treated oriented polypropylene (OPP) film (thickness: 20 μm) was printed three times using a gravure printing machine equipped with a gravure plate with a plate depth of 35 μm. got a layer. Next, using a dry laminator, the printed layer of this laminate was coated with an adhesive R1. At that time, the coating amount of the adhesive after drying was adjusted to 5.0 g. After drying the solvent in an oven, a non-stretched polypropylene (CPP) film (thickness 30 μm) is laminated on top of this at a line speed of 100 m / min, kept at 40 ° C. for 3 days, OPP substrate / printing layer / A packaging material P14 having an adhesive layer/CPP substrate three-print configuration was obtained. The coating amount of the printed layer after drying was 6.0 g/m ² , and the coating amount of the adhesive after drying was 5.0 g/m ² .

(Manufacture of packaging material P15)
A laminate P15 having a structure of NY/adhesive layer/CPP was obtained in the same manner as the manufacturing process of the packaging material P1, except that the front substrate was changed to a corona-treated nylon (NY) film (thickness: 15 μm).

Abbreviations in Table 1 are shown below. The number in parentheses after the abbreviation is the thickness (μm)
OPP: Corona-treated oriented polypropylene film LLDPE: Corona-treated linear low-density polyethylene film CPP: Non-oriented polypropylene film NY: Corona-treated nylon film PP resin layer: Polypropylene-based resin layer

<Manufacture of recycled plastic>
(Example 1) Recycled plastic L1
The packaging material P1 was cut into a size of 2 cm×2 cm, washed with water, and dehydrated. Further, it was dried with hot air until the water content reached 0.5%.
The crushed material of the packaging material P1 obtained above and 0.5% by mass of a compatibilizer (Umex 1010: maleic anhydride-modified PP, melting point 135 ° C.) with respect to the crushed material are mixed with a twin-screw extruder (Japan Steel Works), melted and kneaded at a screw rotation speed of 250 rpm and 230° C., and extruded from the discharge port of an extruder using a 150-mesh filter. The pressure at that time was 3 MPa. After that, it was immediately cut with a pelletizer and cooled by immersing it in cold water. Thus, a recycled plastic L1 was obtained from the packaging material P1. Table 1 shows the water content and chlorine content of the resulting crushed packaging material, the compatibilizing agent used, and other various recycled plastic manufacturing conditions.

(Examples 2 to 18) Recycled plastics L2 to L18
Under the conditions shown in Table 1, L2 to L18 were obtained from recycled plastics recycled from packaging materials in the same manner as the manufacturing process for recycled plastic L1.
The compatibilizers in Table 1 are shown below.
Yumex 1001: manufactured by Sanyo Chemical Industries, Ltd., maleic anhydride-modified PP, melting point 142°C
Yumex 1010: manufactured by Sanyo Chemical Industries, Ltd., maleic anhydride-modified PP, melting point 135°C
Bond Fast-E: manufactured by Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer, melting point 103°C
Bond Fast-7L: Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer, melting point 60 ° C.

(Comparative Examples 1 and 2) Recycled pellets L19 and L20
Pellets L18 and L19, which are recycled plastics recycled from packaging materials, were obtained in the same manner as the manufacturing process of recycled plastic L1 under the conditions shown in Table 1.

<Evaluation of film molding>
Pellets of the recycled plastics L1 to L20 were each extruded at 230° C. using a T-die extruder to produce a film-like molding with a thickness of 50 μm. For each 0.1 m ² of the obtained film, the number and size of foreign matter were confirmed visually and with an optical microscope (VHX-7100), and foreign matter of 100 μm or more was counted and evaluated according to the following criteria. Table 1 shows the evaluation results.
A (excellent): the number of foreign substances of 100 μm or more is less than 5,
B (good): the number of foreign substances of 100 μm or more is 5 or more and less than 15;
C (acceptable): the number of foreign substances of 100 μm or more is 15 or more and less than 30;
D (impossible): the number of foreign substances of 100 μm or more is 30 or more and less than 50;
E (poor): 50 or more foreign matter of 100 μm or more

<Evaluation of bottle-shaped compact>
Pellets of recycled plastics L1 to L20 were each blow-molded at 230° C. using a blow-molding machine to produce bottle-shaped moldings each having a thickness of 1 mm. Regarding the bottles obtained in each example, the number of bottles per 50 bottles in which visually discernable foaming was observed was counted. Table 1 shows the evaluation results.
A (excellent): 1 or less out of 50 bottles in which foaming was observed,
B (good): 2 to 3 out of 50 bottles with foaming observed,
C (acceptable): 4 to 5 out of 50 bottles in which foaming was observed,
D (improper): 6 to 7 out of 50 bottles showed foaming.
E (poor): 8 or more out of 50 bottles showed foaming.

From the above results, it was found that the molded article using the recycled plastic obtained by the production method of the present invention can provide high-quality recycled products with little or no foreign matter. A packaging material containing an olefin resin in which the total mass of the urethane resin (A) derived from the printing and the urethane resin (B) derived from the adhesive in the packaging material is 0.1 to 15% by mass, and a compatibilizer. By melting and kneading in an extrusion device, resin components such as polyolefin resin and urethane resin, which are originally incompatible, are compatible, resulting in less foreign matter derived from the printed layer and adhesive layer, and excellent moldability. It is considered that a recycled plastic was obtained.

Claims (7)

A recycled plastic production method for obtaining recycled plastic from a laminated plastic packaging material and a compatibilizer using an extrusion device equipped with a screw and a discharge part,
The plastic base material constituting the packaging material contains a polyolefin resin,
The packaging material contains 85% by mass or more of polyolefin resin in the total mass of the packaging material,
The packaging material comprises a printed layer containing a urethane resin (A) and/or an adhesive layer containing a urethane resin (B),
The packaging material is a laminated plastic packaging material that has not undergone a separation step between the plastic substrate and the printed layer and/or adhesive layer,
The total mass of the urethane resin (A) and the urethane resin (B) contained in the total mass of the packaging material is 0.1 to 15% by mass,
A step of melting and kneading the packaging material and the compatibilizer in an extrusion device,
The method for producing recycled plastic, wherein the melting and kneading step includes kneading at a screw rotation speed of 50 to 900 rpm. The method for producing recycled plastic according to claim 1 , wherein the laminated plastic packaging material includes an adhesive layer containing a urethane resin (B), and the urethane resin (B) has a glass transition temperature of -30°C to 30°C. . 1. The laminated plastic packaging material comprises an adhesive layer containing a urethane resin (B), and the storage elastic modulus of the urethane resin (B) at a temperature of 150° C. and a frequency of 10 Hz is 0.01 to 10 MPa or less. Or the recycled plastic manufacturing method according to 2. The method for producing recycled plastic according to claim 1 or 2, wherein the laminated plastic packaging material includes an adhesive layer containing a urethane resin (B), and the melting point of the urethane resin (B) is 180 to 280°C. The method for producing recycled plastic according to claim 1 or 2, wherein the compatibilizer has a melting point of 55°C to 140°C. 3. The method for producing recycled plastic according to claim 1, wherein the chlorine content of the laminated plastic packaging material is 0.4% by mass or less in the total mass. 3. The method for producing recycled plastic according to claim 1, further comprising a drying step of reducing the moisture content of the laminated plastic packaging material to 3% by mass or less.