Method for manufacturing post-consumer recycled resin for film molding

Abstract

The aim is to develop new recycling applications for PCR resin and promote resource circulation by enabling the formation of films from PCR resin derived from household waste, which previously had limited uses, through extrusion using an extruder equipped with a specific mesh. [Solution] A method for producing PCR resin for film molding, characterized by melt-extruding a post-consumer recycled resin (PCR resin) mainly composed of polyolefin using an extruder equipped with a screen mesh of 50 mesh (mesh opening: 290-370 μm) to 400 mesh (mesh opening: 35 μm).

Description

[Technical Field]

[0001] This invention relates to a method for producing PCR resin for film molding, which involves melt-extruding a post-consumer recycled resin mainly composed of polyolefin using an extruder. [Background technology]

[0002] In recent years, the importance of recycling plastic products has increased due to growing concern about environmental pollution caused by plastics.

[0003] Among recycling methods, material recycling is considered the most desirable processing method from the standpoint of resource conservation, energy conservation, and economic efficiency. Material recycling includes post-consumer recycled resin (hereinafter referred to as PCR resin), which recycles used products discarded by consumers, and post-industrial recycled resin (hereinafter referred to as PIR resin), which recycles molding losses generated at plastic molding plants. There are various types of PCR resin, such as resin recycled from home appliance waste and resin recycled from used foam trays, but PCR resin recycled from household waste, which is generated in large quantities, can be said to be an important recycling method and product in the domestic waste treatment process. On the other hand, PCR resin derived from household waste has extremely low physical properties and poor moldability, which limits its uses. Therefore, although PCR resin derived from household waste is used in limited applications such as pallets and artificial wood, not all of it can be used in these applications, and much of it is diverted to thermal recycling or export. To solve these problems, it is necessary to expand the applications of the output, and in particular, expanding into film products, which can be said to be a major application in the plastics industry today, is considered desirable from the standpoint of promoting resource circulation. However, the thinner the film, the more pronounced the effect of coarse foreign matter contained in the PCR resin becomes, leading to problems such as holes forming and the film breaking during film formation.

[0004] Patent Document 1 focuses on dispersing polyethylene, polypropylene, and polystyrene contained in PCR resin, and studies have been conducted to improve the physical properties by adding a modifier consisting of a styrene-based thermoplastic elastomer and calcium carbonate as a compatibilizer for these materials.

[0005] Furthermore, Patent Document 2 describes a study on removing foreign matter by extruding the material using an extruder equipped with a screen mesh with an opening of 840 μm or less.

[0006] However, although the mechanical properties have been improved in all of these patent documents, their application to film has not been considered. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2007-291213 [Patent Document 2] Japanese Patent Publication No. 2001-246621 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The present invention aims to provide a manufacturing method for applying PCR resin derived from household waste, which has previously had limited uses, to film applications, and to develop new recycling applications for PCR resin and promote resource circulation. [Means for solving the problem]

[0009] As a result of diligent research to solve the aforementioned problems, the inventors of the present invention have discovered that post-consumer recycled resin (PCR), mainly composed of polyolefin obtained by recycling household waste, can be molded into a film by extruding it in an extruder equipped with a specific mesh and removing foreign matter, thereby completing the present invention.

[0010] In other words, the embodiments of the present invention are as follows [1] to

[11] . [1] A method for producing PCR resin for film molding, comprising melt-extruding a post-consumer recycled resin (PCR resin) mainly composed of polyolefin using an extruder equipped with a screen mesh of 50 mesh (mesh opening: 290-370 μm) to 400 mesh (mesh opening: 35 μm). [2] The method for producing PCR resin for film molding according to [1], wherein the post-consumer recycled resin (PCR resin) is a resin obtained by collecting waste discharged from households and recycling the waste containing polyolefins from said waste. [3] A method for producing a PCR resin for film molding according to any one of the claims [1] to [2], wherein the post-consumer recycled resin (PCR resin) contains 70 to 99 parts by weight of polyolefin and 1 to 30 parts by weight of resin other than polyolefin when the PCR resin is 100 parts by weight. [4] A method for producing a PCR resin for film molding according to any one of the claims [1] to [3], wherein the polyolefin of the post-consumer recycled resin (PCR resin) is polyethylene and / or polypropylene. [5] A method for producing a PCR resin for film molding according to any one of the claims [1] to [4], wherein the post-consumer recycled resin (PCR resin) includes a resin other than polyolefin, and the resin other than polyolefin is at least one selected from the group consisting of polyamide resins, polyester resins, polystyrene resins, polycarbonate resins, styrene-acrylonitrile copolymers, acrylic acid resins, ethylene-vinyl alcohol copolymers, polyvinyl chloride resins, and urethane resins. [6] The method for producing a PCR resin for film molding according to [5], wherein the resin other than polyolefin is at least one selected from the group consisting of polystyrene resin, nylon 6, polyethylene terephthalate, and urethane resin. [7] A method for producing PCR resin for film molding according to any one of the items [1] to [6], wherein the screen mesh is 80 mesh (mesh opening: 180-220 μm) or more and 200 mesh (mesh opening: 80 μm) or less. [8] A method for producing PCR resin for film molding according to any one of [1] to [7], wherein the melt extrusion temperature of the extruder is 170°C or more and 250°C or less. A film made of a PCR resin for film molding obtained by the method for producing a PCR resin for film molding described in any one of the items [9] [1] to [8]. A film comprising a composition containing 50 to 90 parts by weight of a PCR resin for film molding obtained by the method for producing a PCR resin for film molding described in any one of [1] to [8], and 10 to 50 parts by weight of a virgin polyolefin resin. A film comprising a composition containing 50 to 90 parts by weight of PCR resin for film molding obtained by the method for producing PCR resin for film molding described in any one of [1] to [8], and 10 to 50 parts by weight of post-industrial recycled resin (PIR resin) mainly composed of polyolefin. [Effects of the Invention]

[0011] According to the present invention, it is possible to form PCR resin films, and by expanding the applications of recycled resins, it contributes to promoting resource recycling. [Modes for carrying out the invention]

[0012] The present invention will be described in detail below with reference to its preferred embodiments.

[0013] One embodiment of the present invention is a method for producing PCR resin for film molding, characterized by melt-extruding a post-consumer recycled resin (PCR resin) mainly composed of polyolefin using an extruder equipped with a screen mesh of 50 mesh (mesh opening: 290-370 μm) to 400 mesh (mesh opening: 35 μm).

[0014] The manufacturing method of the PCR resin for film forming is a manufacturing method in which a post-consumer recycled resin (PCR resin) mainly composed of polyolefin is melt-extruded by an extruder equipped with a screen mesh of 50 mesh (mesh opening: 290 - 370 μm) or more and 400 mesh (mesh opening: 35 μm) or less. More preferably, a mesh of 80 mesh (mesh opening: 290 - 370 μm) or more and 200 mesh (mesh opening: 80 μm) or less is used, and even more preferably, a mesh of 120 mesh (mesh opening: 132 μm) or more and 200 mesh (mesh opening: 80 μm) or less is used.

[0015] Using 50 mesh or more is preferable because it reduces film perforation due to foreign matter when forming the film. Using 400 mesh or less is preferable because it reduces the increase in resin pressure due to foreign matter clogging during extrusion. Using a screen mesh of less than 50 mesh is not preferable because it is inferior in film formability, and using a screen mesh exceeding 400 mesh is not preferable because the resin pressure is high and the extrusion suitability is poor.

[0016] In the manufacturing method of the PCR resin for film forming, the kneading temperature of the PCR resin is preferably 170°C or more and 250°C or less, and more preferably 180°C or more and 230°C or less. Kneading at 170°C or more is preferable because it can reduce the resin pressure during extrusion, and kneading at 250°C or less is preferable because it can suppress the deterioration of the PCR resin.

[0017] The post-consumer recycled resin (hereinafter referred to as PCR resin) mainly composed of polyolefin refers to a resin obtained by collecting waste discharged from households, selecting waste containing polyolefin from the waste, and recycling it. That is, it is a resin obtained by a recycling process of collecting waste discharged from households, washing, pulverizing, and pelletizing the waste with an extruder. The PCR resin may be obtained by collecting household waste and pelletizing it as it is, or by material selection, etc. It is preferable to perform material selection, etc. because it has excellent physical properties. Examples of the material selection method include specific gravity selection and optical selection.

[0018] The PCR resin only needs to contain polyolefin as the main component, and may also contain resins other than polyolefin. Examples of polyolefins include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymer, etc., which are polyethylene and / or polypropylene. These may be included alone as the polyolefin component or in multiple types. Among these, high-density polyethylene, low-density polyethylene, and linear low-density polyethylene are preferred as the polyolefin. These may be included alone as the polyolefin component or in multiple types.

[0019] Examples of resins other than polyolefin include polyamide resins, polyester resins, polystyrene resins, polycarbonate resins, styrene-acrylonitrile copolymers, acrylic acid resins, ethylene-vinyl alcohol copolymers, polyvinyl chloride resins, urethane resins, etc.

[0020] Examples of polyamide resins include nylon 6, nylon 6,6, nylon II, nylon 12, poly(m-xylylene adipamide), etc.

[0021] Examples of polyester resins include polyethylene terephthalate, glycol-modified polyethylene terephthalate resin (PETG resin), polybutylene terephthalate, polylactic acid, etc.

[0022] Among these, it is preferable that the resin other than polyolefin is at least one selected from the group consisting of polystyrene resin, nylon 6, polyethylene terephthalate, and urethane resin.

[0023] The ratio of resins constituting the PCR resin is preferably 70 to 99 parts by weight of polyolefin and 1 to 30 parts by weight of resins other than polyolefin, and more preferably 80 to 99 parts by weight of polyolefin and 1 to 20 parts by weight of resins other than polyolefin. The total of polyolefin and non-polyolefin resins is 100 parts by weight.

[0024] Furthermore, PCR resin may contain impurities other than the resin components. Impurities refer to both substances intentionally added during the process of obtaining the PCR resin and substances unintentionally mixed into the PCR resin.

[0025] For example, possible impurities present in PCR resin include, but are not limited to, inorganic fillers, antioxidants, acid absorbers, anti-foaming agents, tackifiers, light stabilizers, UV absorbers, anti-blocking agents, plasticizers, waxes, crosslinking agents, release agents, antistatic agents, antibacterial agents, flame retardants, pigments, dyes, paper, synthetic and natural fibers, adhesives, or combinations thereof.

[0026] Examples of inorganic fillers include talc, carbon black, calcium carbonate, titanium dioxide, mica, barite, kaolin, silica, and glass fibers.

[0027] Examples of antioxidants include phenolic antioxidants and phosphorus-based antioxidants.

[0028] Examples of acid acceptors include, but are not limited to, calcium stearate, sodium stearate, zinc stearate, magnesium oxide and zinc oxide, synthetic hydrotalcite, lactate and lactylate, epoxy compounds, or combinations thereof.

[0029] Anti-foaming agents are substances that suppress foaming caused by moisture, and examples include calcium oxide.

[0030] The melt mass flow rate (MFR) of the PCR resin measured under conditions of 190°C and a 2.16 kg load is not particularly limited, but is preferably 0.1 g / 10 min to 30 g / 10 min, more preferably 0.5 g / 10 min to 20 g / 10 min, and most preferably 0.5 g / 10 min to 10 g / 10 min. An MFR of 0.1 g / 10 min or higher is preferred because it does not easily increase the extrusion load when producing PCR resin pellets in the extruder, resulting in excellent productivity. An MFR of 30 g / 10 min or lower is preferred because it provides excellent tensile stability of the strands when producing PCR resin pellets in the extruder.

[0031] When using PCR resin for film molding, it may be used alone, or it may be blended with virgin polyolefin resin or post-industrial recycled resin (hereinafter referred to as PIR resin).

[0032] The mixing ratio of PCR resin for film molding to virgin polyolefin resin or PIR resin is preferably 50 parts by weight or more and 99 parts by weight or less for PCR resin for film molding, and 1 part by weight or more and 50 parts by weight or less for virgin polyolefin resin or PIR resin. The total amount of PCR resin for film molding and virgin polyolefin resin or PIR resin is 100 parts by weight. It is preferable that the amount of PCR resin for film molding is 50 parts by weight or more because it increases the effective utilization rate of the PCR resin, and it is preferable that it is 99 parts by weight or less because it yields a recycled product with excellent mechanical properties. It is also preferable that the amount of virgin polyolefin resin or PIR resin is 1 part by weight or more because it has excellent mechanical properties, and it is preferable that it is 50 parts by weight or less because it increases the effective utilization rate of the PCR resin.

[0033] Examples of virgin polyolefin resins include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, and ethylene-propylene copolymers. These may be used individually or in combination. Among these, high-density polyethylene, low-density polyethylene, and linear low-density polyethylene are preferred as polyolefins, with linear low-density polyethylene being the most preferred. Using linear low-density polyethylene improves the mechanical properties of the blended resin film. Furthermore, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene can be used as comonomers for linear low-density polyethylene, with 1-hexene, 1-octene, and 4-methyl-1-pentene being preferred due to their excellent mechanical properties. In addition, the resin density is 870 kg / m³ due to its excellent mechanical properties. 3 More than 910kg / m 3 The following is preferable, and more preferably, the resin density is 870 kg / m³. 3 More than 900kg / m 3 The following applies:

[0034] PIR resin, while not specifically limited, refers to resin that is recycled from in-process losses, burrs, and substandard products generated in plastic molding plants, and then pelletized again.

[0035] PIR resin can be a single material or a composite of different materials, and it can also be recycled from waste materials such as containers, injection plates, and films.

[0036] The PIR resin obtained from dissimilar multilayer films preferably contains at least a polyolefin and also contains a resin other than a polyolefin.

[0037] Examples of polyolefins include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, and ethylene-propylene copolymers. These may be included individually or in combination. Among these, high-density polyethylene, low-density polyethylene, and linear low-density polyethylene are preferred as polyolefins, with the inclusion of linear low-density polyethylene being the most preferred. Including linear low-density polyethylene improves the mechanical properties of the resin composition obtained by blending the resulting PIR resin with the PCR resin for film molding. Furthermore, propylene, isobutylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene can be used as comonomers for linear low-density polyethylene, with 1-hexene, 1-octene, and 4-methyl-1-pentene being preferred due to their excellent mechanical properties. In addition, the resin density is 870 kg / m³ due to its excellent mechanical properties. 3 More than 910kg / m 3 The following is preferable, and more preferably, the resin density is 870 kg / m³. 3 More than 900kg / m 3 The following applies:

[0038] Furthermore, while not particularly limited, resins other than polyolefins include polyamide resins, polyester resins, polystyrene resins, and ethylene-vinyl alcohol copolymers, and among these, polyamide resins and polyester resins are preferred.

[0039] Examples of polyamide resins include nylon 6, nylon 6,6, nylon 11, nylon 12, and poly(metaxylylene adipamide).

[0040] Examples of polyester resins include polyethylene terephthalate, glycol-modified polyethylene terephthalate resin (PETG resin), polybutylene terephthalate, and polylactic acid.

[0041] Among these, nylon 6 and polyethylene terephthalate are preferred resins other than polyolefins included in the PIR resin.

[0042] The resin composition of the PIR resin obtained by recycling dissimilar multilayer films is preferably 70 to 99 parts by weight of polyolefin and 1 to 30 parts by weight of resin other than polyolefin, and more preferably 80 to 99 parts by weight of polyolefin and 1 to 20 parts by weight of resin other than polyolefin. The total of polyolefin and non-polyolefin resin is 100 parts by weight.

[0043] PIR resins obtained from dissimilar multilayer films may contain compatibilizers to improve their moldability and physical properties.

[0044] The compatibilizer is not particularly limited and can be any agent that can improve the physical properties of the PIR resin, but examples include ethylene-vinyl acetate copolymer, acid-modified polyolefin, ethylene-glycidyl methacrylate copolymer, ionomer resin, oxazoline group-containing resin, and preferably at least one selected from the group consisting of ethylene-vinyl acetate copolymer, maleic anhydride-modified polyethylene, and ethylene-glycidyl methacrylate copolymer.

[0045] The ethylene vinyl acetate copolymer may also be an ethylene vinyl acetate copolymer composition containing multiple types of ethylene vinyl acetate copolymers with different vinyl acetate content. In this case, ethylene From the viewpoint of compatibility, it is preferable to have three or more types of ethylene vinyl acetate copolymers. Furthermore, from the viewpoint of compatibility, an ethylene vinyl acetate copolymer bloc containing multiple types of ethylene vinyl acetate copolymers is preferable. When the product is considered as 100% by weight, the difference in vinyl acetate content of each ethylene vinyl acetate copolymer is preferably 40% by weight or less, and more preferably the difference in vinyl acetate content of at least one set of ethylene vinyl acetate copolymers is 5% by weight or more.

[0046] The melt mass flow rate (MFR) of virgin polyolefin resin and PIR resin measured under conditions of 190°C and a 2.16 kg load is not particularly limited, but is preferably 0.5 g / 10 min to 30 g / 10 min, more preferably 0.8 g / 10 min to 20 g / 10 min, and most preferably 1 g / 10 min to 10 g / 10 min, as it provides excellent film moldability.

[0047] Furthermore, the Vicat softening temperature of virgin polyolefin resin and PIR resin, as measured in accordance with JIS K7206, is preferably 50°C to 100°C, more preferably 60°C to 95°C, and most preferably 70°C to 90°C. When the Vicat softening temperature is 50°C or higher, the resin composition obtained by blending with PCR resin for film molding has a high elastic modulus, resulting in a recyclable product with good rigidity, which is preferable. When the Vicat softening temperature is 100°C or lower, the toughness of the resin composition obtained by blending with PCR is improved, resulting in a recyclable product with excellent mechanical properties, which is also preferable.

[0048] There are no particular restrictions on the method of blending PCR resin for film molding with virgin polyolefin resin or PIR resin, as long as they can be uniformly dispersed. The pellets may be blended together and directly fed into an extruder such as a film molding machine (hereinafter referred to as the dry blend method), or the blended resin may be prepared by melting and kneading it once (hereinafter referred to as the melt blend method) and then fed into a molding machine such as a film molding machine.

[0049] In the dry blending method, the pellets can be pre-blended using a Henschel mixer or tumbler before use.

[0050] In the melt blending method, examples of blending methods include using kneading equipment such as a single-screw extruder, twin-screw extruder, multi-screw extruder, Banbury mixer, pressure kneader, rotary roll, and internal mixer. Among these, single-screw and twin-screw extruders are preferred due to their excellent dispersibility and continuous production capabilities.

[0051] When mixing with a twin-screw extruder, the screw rotation speed is not particularly limited, but it is preferable to mix at 50 rpm to 3000 rpm, and more preferably at 150 rpm to 1000 rpm. A screw rotation speed of 50 rpm or higher is preferable because it improves the dispersibility of each mixed component and results in a resin with excellent physical properties. A screw rotation speed of 3000 rpm or lower is also preferable because it prevents deterioration of the resin due to excessive shear heat, resulting in a resin with excellent physical properties. When using the melt blend method, the mixing temperature is preferably 160°C to 300°C, more preferably 170°C to 250°C, and even more preferably 180°C to 230°C.

[0052] Furthermore, the PCR resin for film molding may be intentionally modified to the extent that it does not impair the effects of the present invention by adding acid absorbers, foam inhibitors, antistatic agents, light stabilizers, ultraviolet absorbers, nucleating agents, antioxidants, blocking inhibitors, flow improvers, mold release agents, flame retardants, colorants, inorganic neutralizing agents, filler conductive agents, chain length extenders, hydrolysis inhibitors, etc.

[0053] Furthermore, PCR resin for film molding can be used in any form, such as pellets or powder.

[0054] The molding method for the PCR resin for film molding is not particularly limited, but examples include inflation molding, co-extrusion inflation molding, T-die molding, co-extrusion T-die molding, extrusion lamination, calendering, and compression molding. Among these, inflation molding, co-extrusion inflation molding, T-die molding, and co-extrusion T-die molding are preferred due to their superior productivity. Furthermore, the film of the present invention may be laminated with other films, and similarly, there are no particular limitations on the lamination method, but examples include dry lamination, extrusion lamination, and sandwich lamination.

[0055] One embodiment of the present invention is a film that can be obtained by forming a film (shaping into a film) from a PCR resin for film molding. The film made of the PCR resin for film molding may be a single layer or can be used as a multilayer film. The lamination structure of the multilayer film is not particularly limited, but for example, it may include not only the resin composition (I) layer but also layers made of other components, such as a virgin resin layer (II), an adhesive layer (III), or a barrier layer (IV). Specifically, examples include (I) / (II), (II) / (I) / (II), (I) / (III) / (IV) / (III) / (I), and (I) / (III) / (IV) / (III) / (II). The thickness of the film made of the above resin composition is not particularly limited, but from the viewpoint of mechanical strength, it is preferably 10 μm to 300 μm.

[0056] The film molding temperature is preferably in the range of 160°C to 250°C, more preferably in the range of 160°C to 230°C, and even more preferably in the range of 160°C to 200°C. A molding temperature of 160°C or higher is preferable because it reduces the occurrence of fish eyes, and a temperature of 250°C or lower is preferable because it provides excellent film moldability.

[0057] The above film is useful as packaging for garbage bags, daily necessities, industrial parts, pharmaceuticals, office supplies, chemical products, etc., as well as for surface protection films, shrink films, transport bags, and more. [Examples]

[0058] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these. (1) Meltmass flow rate (MFR) The MFR of the resin used in this example was measured using a melt indexer (manufactured by Takara Kogyo Co., Ltd.) at 190°C and under a load of 2.16 kg. (2) Density The density of the resin used in this example was measured in accordance with JIS K7112. (3) Vicat softening temperature The Vicat softening temperature of the resin used in this example was measured in accordance with JIS K7206. (4) Extrusion properties When PCR resin was extruded using an extruder, a ○ was given if the resin pressure did not exceed the extruder's upper limit and the strands were cleanly taken up; a △ was given if the resin pressure was 80% or more of the upper limit or if the strands were difficult to take up; and a × was given if the resin pressure exceeded the upper limit or the strands could not be taken up. (5) Film moldability When forming the film using the cast film molding machine, a circle (○) was used to indicate that the film was picked up without any problems, while a cross (×) was used to indicate that the film had holes or torn. (6) Tensile properties The physical properties of the fabricated film in the MD direction (parallel to the film molding flow) and TD direction (perpendicular to the film molding flow) were measured using a tensile testing machine. The film was punched out in both the MD and TD directions using 10mm wide x 100mm long dumbbell test pieces, and measured using a Tensilon tensile testing machine (Orientec, RTE-1210) under conditions of a chuck distance of 30mm and a tensile speed of 200mm / min. The stress and elongation at the point of fracture (elongation at fracture [%] = tensile length required to fracture [mm] / chuck distance 30mm) were measured. [Example 1] The post-consumer recycled resin (PCR resin), primarily composed of polyolefins, was obtained by sorting household waste collected from the city into polyethylene-containing waste (optical sorting, specific gravity sorting), washing, crushing, melt extrusion, and pelletizing using a recycler's equipment. Analysis of the composition of this PCR resin (A1) revealed the following: polyethylene (PE): 78% by weight, polypropylene (PP): 12% by weight, polystyrene (PS): 5% by weight, nylon 6 (PA): 1% by weight, polyethylene terephthalate (PET): 1% by weight, and inorganic materials: 3% by weight. The MFR (Metal Flow Rate) was 0.6 g / 10 min.

[0059] This PCR resin (A1) was extruded using a single-screw extruder (Placo, screw diameter 50 mmφ) equipped with an 80-mesh screen mesh (mesh opening: 290-370 μm) on the die, at a temperature of 200°C, a screw rotation speed of 40 rpm, and a resin extrusion rate of 10 kg / h, to remove coarse foreign matter and obtain PCR resin for film molding. The extrusion moldability was good.

[0060] The obtained PCR resin for film molding was fed into the extruder of a cast film molding machine (manufactured by the Plastics Engineering Research Institute) to form a film. The cast film molding was performed at an extrusion temperature of 180°C, a cooling roll temperature of 30°C, a take-up speed of 4.0 m / min, a film width of 250 mm, and a film thickness of 30 μm. The film moldability was good.

[0061] Table 1 shows the results of the evaluation of the tensile properties of the obtained film, measured using the evaluation method described above. [Example 2] PCR resin for film molding and a single-layer film were obtained using the same method as in Example 1, except that a single-screw extruder equipped with a 100-mesh (mesh opening: 140-150 μm) was used when extruding the PCR resin (A1).

[0062] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Example 3] A PCR resin for film molding and a single-layer film were obtained using the same method as in Example 1, except that a single-screw extruder equipped with a 200-mesh (mesh opening: 80 μm) was used when extruding the PCR resin (A1).

[0063] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Example 4] PCR resin for film molding and a single-layer film were obtained using the same method as in Example 1, except that a single-screw extruder equipped with a 400-mesh (mesh opening: 35 μm) was used when extruding the PCR resin (A1).

[0064] Table 1 shows the results of the evaluation of the extrusion property and the tensile property of the film measured by the above evaluation method. [Example 5] 70 parts by weight of the PCR resin obtained by the same method as in Example 1 and 30 parts by weight of a PIR resin (B1) mainly composed of polyolefin were used. After preliminarily blending these in a tumbler mixer, the blended resin was charged into an extruder of a cast film forming machine (manufactured by Plastic Engineering Laboratory), and a single-layer film was obtained by the same method as in Example 1 except that a film was formed. [[ID=**6**]]

[0065] [[ID=**7**]] [[ID=**8**]] [[ID=**9**]]<00000**9**>[[ID=**10**]]The PIR resin (B1) used pellets obtained by collecting, pulverizing, granulating, and biaxially extruding the trimming loss of a multilayer film generated by a film manufacturer producing a film for food packaging. At this time, a compatibilizer of an ethylene-vinyl acetate copolymer system (manufactured by Tosoh Corporation, MFR 10 g / 10 min, trade name Melsene (registered trademark) SA-5115) was added at 5% by weight based on the trimming loss in the biaxial extrusion process. The biaxial extrusion was carried out at 250 °C. The obtained PIR resin (B1) had an MFR of 4.0 g / min, a density of 950 kg / m[[ID=**11**]]

[0066] [[ID=**12**]] [[ID=**13**]] [[ID=**14**]]Table 1 shows the results of the evaluation of the extrusion property and the tensile property of the film measured by the above evaluation method. [[ID=**15**]] [[ID=**16**]][Example 6][[ID=**17**]] [[ID=**18**]]A single-layer film was obtained by the same method as in Example 5 except that 50 parts by weight of the PCR resin obtained by the same method as in Example 1 and 50 parts by weight of the PIR resin (B1) were used. [[ID=**19**]]

[0067] [[ID=**20**]] [[ID=**21**]] [[ID=**22**]]Table 1 shows the results of the evaluation of the extrusion property and the tensile property of the film measured by the above evaluation method. [[ID=**23**]] [[ID=**24**]][Example 7][[ID=**25**]] [[ID=**26**]]50 parts by weight of the PCR resin obtained by the same method as in Example 1 and linear low-density polyethylene (manufactured by Tosoh Corporation, comonomer: 1-hexene, MFR 2 g / 10 min, density 910 kg / m as virgin polyolefin It seems there are some formatting or numbering irregularities in the original text. I've tried my best to translate it accurately while maintaining the original structure. If you have any further questions or need clarification, please let me know.3 A single-layer film was obtained by the same method as in Example 5, except that 50 parts by weight of product name Nipolon (registered trademark) Z HF210K)(C1) was used, with a Vicat softening temperature of 97°C.

[0068] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Example 8] A PCR resin for film molding and a single-layer film were obtained using the same method as in Example 1, except that the temperature when extruding the PCR resin (A1) was set to 180°C.

[0069] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Example 9] A PCR resin for film molding and a single-layer film were obtained using the same method as in Example 1, except that the temperature when extruding the PCR resin (A1) was set to 230°C.

[0070] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Example 10] A PCR resin for film molding and a single-layer film were obtained using the same method as in Example 2, except that the temperature when extruding the PCR resin (A1) was set to 160°C.

[0071] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Example 11] A PCR resin for film molding and a single-layer film were obtained using the same method as in Example 2, except that the temperature when extruding the PCR resin (A1) was set to 260°C.

[0072] Table 1 shows the results of the evaluations, which measured the extrudeability and tensile properties of the film using the evaluation method described above. [Comparative Example 1] A PCR resin for film molding was obtained using the same method as in Example 1, except that a mesh was not used when extruding the PCR resin (A1).

[0073] When this PCR resin for film molding was used to form a film under the same conditions as in Example 1, holes were formed in the film starting from foreign matter, and it was not possible to obtain a film worthy of evaluation. [Comparative Example 2] PCR resin for film molding was obtained using the same method as in Example 1, except that a single-screw extruder equipped with a 30-mesh screen (mesh opening: 510-630 μm) was used when extruding the PCR resin (A1).

[0074] When this PCR resin for film molding was used to form a film under the same conditions as in Example 1, holes were formed in the film starting from foreign matter, and it was not possible to obtain a film worthy of evaluation. [Comparative Example 3] Except for using 70 parts by weight of PCR resin and 30 parts by weight of PIR resin (B1) obtained by the same method as in Comparative Example 1, film molding was performed under the same conditions as in Example 5. As a result, holes were formed in the film starting from foreign matter, and a film worthy of evaluation could not be obtained. [Comparative Example 4] Except for using 50 parts by weight of PCR resin and 50 parts by weight of PIR resin (B1) obtained by the same method as in Comparative Example 1, film molding was performed under the same conditions as in Example 5. As a result, holes were formed in the film starting from foreign matter, and a film worthy of evaluation could not be obtained. [Comparative Example 5] Except for using 50 parts by weight of PCR resin obtained by the same method as in Comparative Example 1 and 50 parts by weight of virgin polyolefin (C1), film molding was performed under the same conditions as in Example 5. As a result, holes were formed in the film starting from foreign matter, and a film worthy of evaluation could not be obtained.

[0075] [Table 1] [Industrial applicability]

[0076] Films made from the resin composition of the present invention are useful as packaging containers for garbage bags, daily necessities, industrial parts, pharmaceuticals, office supplies, chemical products, etc., as well as surface protection films, shrink films, transport bags, and the like.

Claims

1. A method for producing PCR resin for film molding, comprising melt-extruding a post-consumer recycled resin (PCR resin) mainly composed of polyolefin using an extruder equipped with a screen mesh of 50 mesh (mesh opening: 290-370 μm) to 400 mesh (mesh opening: 35 μm).

2. The method for producing a PCR resin for film molding according to claim 1, wherein the post-consumer recycled resin (PCR resin) is a resin obtained by collecting waste discharged from households, selecting waste containing polyolefins from said waste, and recycling it.

3. The method for producing a PCR resin for film molding according to claim 1, wherein the post-consumer recycled resin (PCR resin) contains 70 to 99 parts by weight of polyolefin and 1 to 30 parts by weight of a resin other than polyolefin when the PCR resin is 100 parts by weight.

4. A method for producing a PCR resin for film molding according to claim 1, wherein the polyolefin of the post-consumer recycled resin (PCR resin) is polyethylene and / or polypropylene.

5. A method for producing a PCR resin for film molding according to claim 1, wherein the post-consumer recycled resin (PCR resin) includes a resin other than polyolefin, and the resin other than polyolefin is at least one selected from the group consisting of polyamide resins, polyester resins, polystyrene resins, polycarbonate resins, styrene-acrylonitrile copolymers, acrylic acid resins, ethylene-vinyl alcohol copolymers, polyvinyl chloride resins, and urethane resins.

6. The method for producing PCR resin for film molding according to claim 5, wherein the resin other than the polyolefin is selected from the group consisting of polystyrene resin, nylon 6, polyethylene terephthalate, and urethane resin.

7. The method for producing PCR resin for film molding according to claim 1, wherein the screen mesh is 80 mesh (mesh opening: 180-220 μm) or more and 200 mesh (mesh opening: 80 μm) or less.

8. The method for producing PCR resin for film molding according to claim 1, wherein the melt extrusion temperature of the extruder is 170°C or higher and 250°C or lower.

9. A film made of a PCR resin obtained by the method for producing a PCR resin for film molding according to any one of claims 1 to 8.

10. A film comprising a composition containing 50 to 90 parts by weight of a PCR resin for film molding obtained by the method for producing a PCR resin for film molding according to any one of claims 1 to 8, and 10 to 50 parts by weight of a virgin polyolefin resin.

11. A film comprising a composition containing 50 to 90 parts by weight of PCR resin for film molding obtained by the method for producing PCR resin for film molding described in any one of claims 1 to 8, and 10 to 50 parts by weight of post-industrial recycled resin (PIR resin) mainly composed of polyolefin.

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