Recycled resin composition, recycled resin molded article, method for manufacturing the recycled resin composition, and method for manufacturing the recycled resin molded article

Abstract

The present invention provides a recycled resin composition that possesses good mechanical strength and excellent moldability at low temperatures. [Solution] The recycled resin composition comprises a first recycled resin with a melting point of 200°C or lower, a second recycled resin with a melting point exceeding 200°C, and a reactive compatibilizer. The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:1. The content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less, relative to the total mass of the recycled resin composition.

Description

Technical Field

[0001] The present invention relates to a recycled resin composition, a recycled resin molded body, a method for producing a recycled resin composition, and a method for producing a recycled resin molded body.

Background Art

[0002] In recent years, in consideration of environmental problems and the like, interest in resource recycling has been increasing. Such resources include resin waste materials and the like.

[0003] Resin waste materials are a mixture of various resins, but it is very difficult to separate and reuse each resin from such resin waste materials. Therefore, it has been studied to use resin waste materials having various resins as recycled resins as they are as a mixture.

[0004] Patent Document 1 discloses a specific graft polymer obtained by polymerizing an aromatic vinyl and an unsaturated nitrile in the presence of a hydrogenated isoprene copolymer as a compatibilizer used when recycling a styrene-based resin and an olefin-based resin. It is described that when such a compatibilizer is used, the decrease in the impact strength of the recycled product is improved.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, according to the findings of the present inventors, when a compatibilizer as described in Patent Document 1 is used, the molded body obtained from such a resin still has dissatisfaction in mechanical strength such as tensile strength.

[0007] Furthermore, recycled resins contain foreign matter due to the attachment of dirt and other substances. When recycled resin compositions containing such recycled resins are used for molding at high temperatures, problems can arise such as the progression of phase separation between the foreign matter and the resin, the formation of defects at the interface between the foreign matter and the resin, resulting in unstable molding, accelerated degradation of the resin by the foreign matter, or bleeding out onto the surface of the molded product, making it difficult to obtain a molded product of good quality. For this reason, it is desirable that such recycled resin compositions be molded at relatively low temperatures (for example, below 200°C). However, as described in Patent Document 1, recycled resin compositions containing high-melting-point resins (styrene-based resins) present the challenge of difficulty in molding at low temperatures.

[0008] This invention has been made in view of the above circumstances, and aims to provide a recycled resin composition, a recycled resin molded article, a method for producing a recycled resin composition, and a method for producing a recycled resin molded article that have good mechanical strength and excellent moldability at low temperatures. [Means for solving the problem]

[0009] One aspect of the present invention relates to the recycled resin compositions described below [1] to [5].

[0010] [1] A first recycled resin with a melting point of 200°C or less, Second recycled resin with a melting point exceeding 200℃, Reactive compatibilizer, A recycled resin composition comprising, The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:1. The content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less, relative to the total mass of the recycled resin composition. Recycled resin composition.

[0011] [2] The first recycled resin comprises polyethylene resin and / or polypropylene resin, The second recycled resin includes a polyester resin and / or a polystyrene resin. [1] The recycled resin composition described above.

[0012] [3] The reactive compatibilizer comprises an ethylene / glycidyl (meth)acrylate copolymer, The recycled resin composition described in [1] or [2].

[0013] [4] The ratio of structural units derived from glycidyl (meth)acrylate to the total mass of the reactive compatibilizer is 5% by mass or more and 13% by mass or less. A recycled resin composition as described in any of [1] to [3].

[0014] [5] The ratio of structural units derived from glycidyl (meth)acrylate to the total mass of the reactive compatibilizer is 5% by mass or more and 7% by mass or less. A recycled resin composition as described in any of [1] to [4].

[0015] One aspect of the present invention relates to recycled resin molded articles as described in [6] to [7] below.

[0016] [6] A recycled resin composition comprising any of the following: [1] to [5] Recycled resin molded product.

[0017] [7] Film-like material with a thickness of 100 μm or less, [6] Recycled resin molded articles as described above.

[0018] One aspect of the present invention relates to a method for producing the recycled resin composition described in [8] below.

[0019] [8] A step of preparing a recycled resin mixture comprising a first recycled resin having a melting point of 200°C or less and a second recycled resin having a melting point of over 200°C, A method for producing a recycled resin composition, comprising the step of melt-kneading the recycled resin mixture and a reactive compatibilizer, The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:1, the content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less based on the total mass of the recycled resin composition, A method for producing a recycled resin composition.

[0020] One aspect of the present invention relates to a method for producing a recycled resin molded body according to [9] below.

[0021] [9] A method for producing a recycled resin molded body by melting and molding the recycled resin composition according to any one of [1] to [5], where the melting temperature during the melting and molding is 200°C or lower, A method for producing a recycled resin molded body.

Effects of the Invention

[0022] According to the present invention, it is possible to provide a recycled resin composition having good mechanical strength and excellent molding suitability at low temperatures, a recycled resin molded body, a method for producing a recycled resin composition, and a method for producing a recycled resin molded body.

Modes for Carrying Out the Invention

[0023] Hereinafter, one embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiment. Also, in this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

[0024] 1. Recycled resin composition The recycled resin composition according to this embodiment is a first recycled resin having a melting point of 200°C or lower, a second recycled resin having a melting point exceeding 200°C, a reactive compatibilizer, and is a recycled resin composition containing The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:1. The content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less, based on the total mass of the recycled resin composition.

[0025] Such recycled resin compositions possess good mechanical strength and excellent moldability at low temperatures. The reason for this is not entirely clear, but it is thought to be as follows.

[0026] As mentioned above, it is extremely difficult to completely separate and reuse each resin from resin waste. When resin waste is used as recycled resin, it generally contains both a first recycled resin with a melting point below 200°C and a second recycled resin with a melting point above 200°C. However, the first and second recycled resins often have low compatibility, and phase separation is likely to occur between them, leading to defects at the interfaces of each recycled resin. As a result, the mechanical strength of such resin mixtures tends to decrease.

[0027] Furthermore, in the process of manufacturing the molded product, the physical properties of the first recycled resin and the second recycled resin differ when heated. Generally, the physical properties of resins change significantly depending on whether the temperature is above or below the melting point. When melt molding is performed at relatively low temperatures (for example, below 200°C), the molding temperature is often set to a temperature above the melting point of the first recycled resin and below the melting point of the second recycled resin. As a result, the difference in physical properties (e.g., elastic modulus, elongation at break) between the first recycled resin and the second recycled resin at the molding temperature becomes significantly large. Consequently, when stress is applied during the molding process, for example, when the product is stretched in the winding direction during transport, stress tends to concentrate near the interface between the different resins, leading to defects such as holes in the molded product and a deterioration in moldability.

[0028] Recycled resins may have carboxyl groups or other reactive groups due to oxidative degradation, for example. Furthermore, depending on the type of resin (e.g., polyester resin, polyamide resin, etc.), they may contain reactive groups such as carboxyl groups, amino groups, and hydroxyl groups. Therefore, by using a predetermined amount of reactive compatibilizer, for example, if the reactive compatibilizer is a copolymer having a block that reacts with at least one of the first recycled resin and the second recycled resin, and a block that has high affinity with the other block, the reactive compatibilizer can contribute to improving the compatibility between the first recycled resin and the second recycled resin. Also, for example, if the reactive compatibilizer is a compound having multiple reactive groups, it can crosslink the resins together, reducing the mobility of each resin at the molding temperature, suppressing the progression of aggregation between the resins, and making phase separation less likely. In addition, by adjusting the ratio of the first recycled resin and the second recycled resin to a predetermined ratio, the reactive compatibilizer can act effectively, making it less likely for defects to occur at the interface between the different resins, resulting in a significant increase in mechanical strength.

[0029] Similarly, by adjusting the ratio to a predetermined level so that the proportion of the second recycled resin does not become too high, and by using a predetermined proportion of reactive compatibilizer, it is possible to appropriately adjust the viscosity of the composition at the molding temperature and improve the uniformity of the composition's physical properties. Therefore, it is thought that the moldability when molding at relatively low temperatures will be improved.

[0030] 1-1. First recycled resin with a melting point of 200℃ or less The first recycled resin is not particularly limited as long as it is a resin with a melting point of 200°C or less, and may be a single type of resin or a combination of two or more types of resins.

[0031] The melting point of the resin in this application is the value measured in accordance with JIS K 7122:2012.

[0032] Examples of first recycled resins include: Polyolefin resins such as polyethylene resins and polypropylene resins; Polyolefin resins containing functional groups, such as ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-alkyl acrylate copolymer, ethylene-alkyl methacrylate copolymer, maleic acid-modified polyethylene, and maleic acid-modified polypropylene; Thermoplastic polyester resins such as polybutylene succinate and polylactic acid, which are aliphatic polyester resins; Polyvinyl chloride, polyvinylidene chloride, and other polyvinyl chloride-based resins; These are some examples.

[0033] Among these, the first recycled resin preferably contains a polyolefin resin, more preferably a polyethylene resin and / or a polypropylene resin, and even more preferably a polyethylene resin. Using such a resin makes it easier to improve the processability at low temperatures, and when made into a film, it is easier to obtain good flexibility and mechanical strength.

[0034] Polyolefin resins are resins whose main component is olefin-derived structural units. In this application, a polyolefin resin is a resin in which the amount of olefin-derived structural units relative to the total structural units constituting the polyolefin resin is 50% by mass or more. A polyolefin resin may be a homopolymer of one olefin, a copolymer of two or more olefins, or a copolymer of one or more olefins and one or more other monomers (monomers other than olefins). The amount of olefin-derived structural units in the polyolefin resin is preferably 75% by mass or more, more preferably 85% by mass or more, and even more preferably 90% by mass or more.

[0035] Examples of olefins include ethylene and α-olefins having 3 to 10 carbon atoms. Specific examples of olefins include ethylene, propylene, 1-butene, isobutylene, 1-pentene, 3-methyl-1-butene, 1-hexene, 3,4-dimethyl-1-butene, 1-heptene, 3-methyl-1-hexene, and 1-octene. Polyolefin resins may contain only one of these constituent units, or two or more.

[0036] Other examples of monomers used in polyolefin resins include diene monomers such as 1,4-hexadiene, 1,6-octadiene, 5-methyl-1,4-hexadiene, 3,7-dimethyl-1,6-octadiene, dicyclopentadiene (DCPD), ethylidene norbornene (ENB), norbornadiene, and 5-vinyl-2-norbornene; acid (or acid anhydride) modified olefins such as maleic anhydride modified olefins; and (meth)acrylates such as methyl (meth)acrylate. Polyolefin resins may contain only one of these constituent units, or two or more.

[0037] In this specification, "polypropylene resin" refers to a resin having 50% or more by mass of propylene-derived structural units, and includes propylene homopolymers and copolymers of propylene and other monomers (propylene copolymers). Propylene homopolymers include isotactic, syndiotactic, atactic, hemiisotactic, and linear or branched polypropylenes exhibiting various stereoregularities. Note that the stereoregularity of propylene is 13It can be identified by 1C-NMR or the like. Furthermore, the propylene copolymer may be a random copolymer or a block copolymer. Also, the propylene copolymer may be a binary copolymer of propylene and other monomers, or a polypolymer of propylene and two or more other monomers. Examples of preferred copolymer components (other monomers) include ethylene, α-olefins with 4 or more carbon atoms, tetrafluoroethylene, vinyl acetate, etc. In this embodiment, the polypropylene resin is preferably a propylene homopolymer or a propylene copolymer in which the constituent units derived from other monomers are less than 5% by mass.

[0038] In this specification, "polyethylene resin" refers to a resin having 50% by mass or more of ethylene-derived structural units, and includes ethylene homopolymers and copolymers of ethylene and other monomers (ethylene copolymers). Examples of ethylene homopolymers include high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene, and linear low-density polyethylene (LLDPE). Furthermore, the ethylene copolymer may be a binary copolymer of ethylene and other monomers, or a polypolymer of ethylene and two or more other monomers. Examples of preferred copolymer components (other monomers) include vinyl acetate and α-olefins having 3 or more carbon atoms. In this embodiment, the polyethylene resin is preferably an ethylene homopolymer or an ethylene copolymer having less than 5% by mass of structural units derived from other monomers.

[0039] The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:1, preferably 80:20 to 99:1, more preferably 85:15 to 99:1, and even more preferably 90:10 to 99:1. As described above, when the amount of the first recycled resin is greater than 75:25, defects in the composition are less likely to occur, mechanical strength tends to increase, and the amount of the second recycled resin, which has a high melting point, does not become too large, thus improving moldability at low temperatures. In addition, when formed into a film, it is easier to obtain a good appearance and good flexibility. Furthermore, when the amount of the first recycled resin is less than 99:1, the proportion of the second recycled resin, which tends to have higher mechanical strength than the first recycled resin, increases, so in the presence of a reactive compatibilizer, mechanical strength tends to increase.

[0040] The content of the first recycled resin in the recycled resin composition is not particularly limited, but from the same viewpoint as above, it is preferably 75% by mass or more and 98% by mass or less of the total mass of the recycled resin composition.

[0041] 1-2. Second recycled resin with a melting point exceeding 200°C The second recycled resin is not particularly limited as long as it is a resin with a melting point exceeding 200°C, and may be a single type of resin or a combination of two or more types of resins.

[0042] Examples of recycled resins include: Polyamide resins such as nylon-6, nylon-6,6, nylon-6,10, and nylon-6,12; Polyester resins such as polyethylene terephthalate and its copolymers, polyethylene naphthalate, polybutylene terephthalate, and other aromatic polyester resins; Polycarbonate resins such as aromatic polycarbonates and aliphatic polycarbonates; Polystyrene resins such as atactic polystyrene, syndiotactic polystyrene, acrylonitrile-styrene (AS) copolymer, and acrylonitrile-butadiene-styrene (ABS) copolymer; Polyphenylene sulfide; Polyethersulfones, polyetherketones, polyetheretherketones and other polyether resins, These are some examples.

[0043] The second recycled resin preferably contains a polyamide resin, a polyester resin, or a polycarbonate resin, and more preferably a polyester resin. These resins may have reactive groups such as carboxyl groups, which increases their reactivity with reactive compatibilizers. In particular, these recycled resins are repeatedly melted and heated, foreign matter accelerates resin degradation, and hydrolysis occurs in some structures, making them more reactive with reactive compatibilizers compared to virgin materials. Furthermore, from the viewpoint of increasing compatibility with the first recycled resin, which has relatively low polarity, embodiments containing a relatively low polarity polystyrene resin are also preferably used. From the above viewpoint, embodiments in which the second recycled resin contains polyester and / or a polystyrene resin are also preferably used.

[0044] The content of the second recycled resin in the recycled resin composition is not particularly limited, but from the same viewpoint as above, it is preferably 0.5% by mass or more and 25% by mass or less of the total mass of the recycled resin composition.

[0045] 1-3. Reactive compatibilizers The reactive compatibilizer is not particularly limited as long as it contains a reactive site and compatibilizes the first recycled resin and the second recycled resin.

[0046] Examples of reactive sites included in reactive compatibilizers include double bond sites, carboxyl groups or carboxylic acid anhydride sites, epoxy groups, or oxazoline sites.

[0047] Examples of reactive compatibilizers containing epoxy groups include ethylene / glycidyl (meth)acrylate copolymers. Examples of commercially available reactive compatibilizers containing epoxy groups include Bondfast 2C, Bondfast E, Bondfast 30C, Bondfast CG5001, Bondfast 2B, Bondfast 7B, Bondfast 7L, Bondfast 7M (all manufactured by Sumitomo Chemical Co., Ltd., "Bondfast" is a registered trademark of the company), Modiper A4100, Modiper A4300, Modiper A4400, Modiper CL430-G (all manufactured by NOF Corporation, "Modiper" is a registered trademark of the company). In this application, "(meth)acrylate" may refer to an acrylate compound, a methacrate compound, or a mixture thereof.

[0048] An ethylene / glycidyl (meth)acrylate copolymer is any copolymer having structural units derived from ethylene and structural units derived from glycidyl (meth)acrylate. Examples include ethylene / glycidyl (meth)acrylate / vinyl alcohol copolymer, ethylene / glycidyl (meth)acrylate / (meth)acrylate copolymer, ethylene / glycidyl (meth)acrylate / acrylonitrile / styrene copolymer, ethylene / glycidyl (meth)acrylate / methyl (meth)acrylate copolymer, and ethylene / glycidyl (meth)acrylate / styrene copolymer.

[0049] Examples of reactive compatibilizers containing a carboxyl group or carboxylic acid anhydride moiety include styrene / maleic anhydride copolymer, methyl (meth)acrylate / maleic anhydride copolymer, maleic anhydride-modified polyethylene, maleic anhydride-modified polypropylene, and ethylene / maleic anhydride / ethyl (meth)acrylate. Examples of commercially available reactive compatibilizers containing a carboxyl group or carboxylic acid anhydride moiety include Rexpearl ET (Nippon Polyethylene Co., Ltd., "Rexpearl" is a registered trademark of the company).

[0050] Examples of reactive compatibilizers containing an oxazoline moiety include mixtures of bisoxazoline and styrene / maleic anhydride copolymer, mixtures of bisoxazoline and maleic anhydride-modified polyethylene, mixtures of bisoxazoline and maleic anhydride-modified polypropylene, or polymers containing an oxazoline moiety in their side chains (for example, the Epocross series: manufactured by Nippon Shokubai Co., Ltd., "Epocross" is a registered trademark of the company).

[0051] Among these, from the viewpoint of reacting with carboxyl groups, hydroxyl groups, etc., contained in the recycled resin, the reactive site in the reactive compatibilizer is preferably a carboxyl group or carboxylic acid anhydride site, an epoxy group, a carbodiimide group, or an oxazoline site, and more preferably an epoxy group. Similarly, the reactive compatibilizer preferably contains an ethylene / glycidyl (meth)acrylate copolymer, and more preferably the ethylene / glycidyl (meth)acrylate copolymer is 50% by mass or more, even more preferably 75% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 99% by mass or more, and most preferably only the ethylene / glycidyl (meth)acrylate copolymer is present. With this configuration, when the first recycled resin contains a low-polarity resin (for example, a polyolefin resin such as polyethylene resin or polypropylene resin), the compatibility between the first recycled resin and the second recycled resin tends to increase.

[0052] Furthermore, from a similar viewpoint, it is preferable that the ethylene / glycidyl (meth)acrylate copolymer contained in the reactive compatibilizer is a copolymer having substantially only structural units derived from ethylene and structural units derived from glycidyl (meth)acrylate. In this application, "having substantially only structural units derived from ethylene and structural units derived from glycidyl (meth)acrylate" means that the amount of structural units other than those derived from ethylene and glycidyl (meth)acrylate is 1% by mass or less, preferably 0.1% by mass or less, and more preferably none.

[0053] When the reactive compatibilizer contains an ethylene / glycidyl (meth)acrylate copolymer, or when it contains a polymer having structural units derived from glycidyl (meth)acrylate, the content ratio of structural units derived from glycidyl (meth)acrylate is preferably 5% by mass or more and 13% by mass or less, and more preferably 5% by mass or more and 7% by mass or less, relative to the total mass of the reactive compatibilizer. If the content ratio is 5% by mass or more, it reacts more easily with recycled resin, making it easier to obtain compatibilization ability and improving mechanical strength and moldability at low temperatures. If the content ratio is 13% by mass or less, the reactivity does not become too high, making it less likely to become hard and brittle, and improving moldability at low temperatures and making it easier to obtain a good appearance.

[0054] The content of the reactive compatibilizer is preferably 0.1% to 10.0% by mass, and more preferably 0.5% to 5.0% by mass, relative to the total mass of the recycled resin composition. If the content of the reactive compatibilizer is above the lower limit, it reacts more easily with the recycled resin, making it easier to obtain compatibilization ability and improving mechanical strength and moldability at low temperatures. If the content of the reactive compatibilizer is below the upper limit, the reactivity does not become too high, making it less likely to become hard and brittle, and improving moldability at low temperatures and obtaining a good appearance.

[0055] 1-4. Other ingredients The recycled resin composition according to this embodiment may further contain other components not mentioned above, as long as they do not impair the purpose and effects of this embodiment. Examples of other components include lubricants, inorganic powders, plasticizers, colorants, antioxidants, flame retardants, foaming agents, and flow regulators. These other components may be originally present in the resin waste material that serves as the raw material for the recycled resin, or they may be added during the manufacturing of the recycled resin composition.

[0056] Examples of lubricants include fatty acid-based lubricants such as stearic acid, hydroxystearic acid, complex stearic acid, and oleic acid; aliphatic alcohol-based lubricants; aliphatic amide-based lubricants such as stearamide, oxystearamide, oleylamide, erucylamide, ricinolamide, behenamide, methylolamide, methylenebisstearoamide, methylenebisstearobehenamide, bisamic acid (a higher fatty acid), and complex amides; aliphatic ester-based lubricants such as n-butyl stearate, methyl hydroxystearate, polyhydric alcohol fatty acid esters, saturated fatty acid esters, and ester waxes; and fatty acid metal soap-based lubricants, such as zinc stearate and magnesium stearate. Examples of commercially available lubricants include Aamide AP-1 (manufactured by Mitsubishi Chemical Corporation).

[0057] The recycled resin composition according to this embodiment preferably contains a lubricant. As described above, the lubricant has hydrophobic parts such as long-chain alkyl groups and hydrophilic parts such as carboxyl groups, improving the fluidity of the resin so that it can be efficiently kneaded and uniformly dispersed. For example, even if the recycled resin contains dirt or impurities, it is thought that the compatibility with the resin can be improved. As a result, defects are less likely to occur at the interface between the dirt or impurities and the resin, and the suitability for molding at low temperatures is likely to be improved. In addition, in tensile strength measurement, which is a general test method for mechanical strength, stress is applied to the molded body and the maximum stress when the stress is applied until it breaks is defined as the tensile strength. Therefore, if defects occur at the interface between the dirt or impurities and the resin, the elongation at break tends to be small and the tensile strength tends to be low. Therefore, by including a lubricant, defects are reduced and the mechanical strength becomes relatively uniform within the composition, so it is thought that mechanical strength such as elongation at break and tensile strength can be improved in particular. In addition, since the lubricant can also act as a surfactant, a smooth appearance is more easily obtained when it is made into a film. From this viewpoint, the lubricant is preferably stearate amide.

[0058] When the recycled resin composition contains a lubricant, the lubricant content is preferably 0.05% by mass or more and 0.50% by mass or less, relative to the total mass of the recycled resin composition. This range makes it easier to obtain the above-mentioned effects.

[0059] Inorganic powders are powders composed of inorganic substances. The type of inorganic substance can be selected according to the application of the resin composition. Examples of inorganic substances include calcium, magnesium, aluminum, titanium, iron, zinc, silicon, barium, molybdenum, sodium, and potassium carbonates, silicates, phosphates, borates, oxides, sulfates, or hydrates thereof. Inorganic carbon compounds are also included as examples of inorganic substances.

[0060] Specific examples of inorganic substances include calcium carbonate, magnesium carbonate, zinc oxide, titanium dioxide, silica, alumina, clay (e.g., talc and kaolin), aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, calcium silicate, aluminum sulfate, magnesium sulfate, calcium sulfate, magnesium phosphate, barium sulfate, silica sand, carbon black, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium sulfite, sodium sulfate, potassium titanate, bentonite, wollastonite, dolomite, and graphite. These may be synthesized or derived from natural minerals. Inorganic powders may contain only one or more of these substances.

[0061] Examples of plasticizers include triethyl citrate, acetyl triethyl citrate, dibutyl phthalate, diaryl phthalate, dimethyl phthalate, diethyl phthalate, dioctyl phthalate, di(2-ethylhexyl) phthalate, di-2-methoxyethyl phthalate, dibutyl tartrate, o-benzoyl benzoate, diacetin, and epoxidized soybean oil. The resin composition may contain one of these individually or two or more.

[0062] The colorant may be any known organic pigment, inorganic pigment, or dye. Specific examples of colorants include organic pigments such as azo, anthraquinone, phthalocyanine, quinacridone, isoindolinone, diosadin, perinone, quinophthalone, and perylene pigments; and inorganic pigments such as ultramarine, titanium yellow, and chromium oxide. The resin composition may contain one or more of these.

[0063] Examples of antioxidants include phosphorus-based antioxidants, phenol-based antioxidants, and pentaerythritol-based antioxidants. The resin composition may contain one or more of these. Phosphorus-based antioxidants, more specifically phosphorus-based antioxidants such as phosphite esters and phosphate esters, are preferred. Examples of phosphite esters include triesters, diesters, and monoesters of phosphite such as triphenyl phosphite, trisnonylphenyl phosphite, and tris(2,4-di-t-butylphenyl) phosphite.

[0064] Examples of phosphate esters include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, tris(nonylphenyl) phosphate, and 2-ethylphenyldiphenyl phosphate.

[0065] Examples of phenolic antioxidants include α-tocopherol, butylhydroxytoluene, cinapyl alcohol, vitamin E, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-t-butyl-6-(3'-t-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-t-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-t-butyl-4-hydroxybenzylphosphonate diethyl ester, and tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxymethyl]methane.

[0066] The flame retardant is not particularly limited, but for example, halogenated flame retardants or non-phosphorus halogenated flame retardants such as phosphorus-based flame retardants or metal hydrates can be used. The resin composition may contain one of these alone or two or more of them.

[0067] Examples of halogenated flame retardants include halogenated bisphenol compounds such as halogenated bisphenylalkanes, halogenated bisphenyl ethers, halogenated bisphenyl thioethers, and halogenated bisphenylsulfones, as well as bisphenol-bis(alkyl ether) compounds such as brominated bisphenol A, brominated bisphenol S, chlorinated bisphenol A, and chlorinated bisphenol S. Examples of phosphorus-based flame retardants include aluminum tris(diethylphosphinate), bisphenol A bis(diphenyl phosphate), triarylisopropyl phosphate, cresyl di2,6-xylenyl phosphate, and aromatic condensed phosphate esters. Examples of metal hydrates include aluminum trihydrate, magnesium dihydrate, or combinations thereof.

[0068] Furthermore, flame retardants and flame retardant additives may be combined. Examples of flame retardant additives include antimony oxides such as antimony trioxide and antimony pentoxide, and other known flame retardant additives.

[0069] The blowing agent is not particularly limited as long as it is a compound capable of generating bubbles when mixed with or injected under pressure into a composition that is in a molten state in a melting kneader. Examples of blowing agents include those that change phase from solid to gas to generate bubbles, those that change phase from liquid to gas to generate bubbles, those that decompose from solid or liquid to generate gas, or gas itself.

[0070] Examples of foaming agents include aliphatic hydrocarbons such as propane, butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclobutane, cyclopentane, and cyclohexane; halogenated hydrocarbons such as chlorodifluoromethane, difluoromethane, trifluoromethane, trichlorofluoromethane, dichloromethane, dichlorofluoromethane, dichlorodifluoromethane, chloromethane, chloroethane, dichlorotrifluoroethane, dichloropentafluoroethane, tetrafluoroethane, difluoroethane, pentafluoroethane, trifluoroethane, dichlorotetrafluoroethane, trichlorotrifluoroethane, tetrachlorodifluoroethane, and perfluorocyclobutane; pyrolytic compounds such as azodicarbonamide, N,N'-dinitropentamethylenetetramine, 4,4'-oxybisbenzenesulfonyl hydrazide, carbon dioxide, and sodium hydrocarbons; inorganic gases such as nitrogen and air; and water.

[0071] The foaming agent may contain the active ingredient of the foaming agent together with the carrier resin. Examples of carrier resins include crystalline olefin resins such as crystalline propylene. Examples of active ingredients include bicarbonates. Of these, bicarbonates are preferred. Preferably, the foaming agent concentrate contains crystalline polypropylene resin as the carrier resin and bicarbonate as a thermal decomposition type foaming agent.

[0072] Known fluidity modifiers can also be used. Examples of fluidity modifiers include peroxides such as dialkyl peroxides, for example, 1,4-bis[(t-butylperoxy)isopropyl]benzene. Depending on the type of thermoplastic resin used, these peroxides can also act as crosslinking agents. In particular, if the thermoplastic resin (polyolefin resin) has constituent units derived from dienes, the dienes may be crosslinked with the peroxide.

[0073] Examples of antistatic agents include fatty acid diethanolamides such as lauryl diethanolamide and stearyl diethanolamide; and hydroxyl group-containing compounds, including alcoholamine compounds. Alcoholamines, such as monoethanolamine, diethanolamine, and triethanolamine, are particularly preferred. Two or more antistatic agents can also be used in combination. These antistatic agents may be supported on calcium silicate or calcium carbonate. Furthermore, a range of 8 to 22 carbon atoms in the acyl group of fatty acid diethanolamides is preferred from the viewpoint of exhibiting sufficient antistatic effect.

[0074] The total amount of other components in the resin composition is not particularly limited, but can be, for example, 5% by mass or less relative to the total amount of the resin composition.

[0075] 1-5. Shape of recycled resin composition The shape of the resin composition according to this embodiment is not particularly limited and can be any shape, such as particulate, pelletized, or lumpy. If the resin composition is pelletized, the shape of the pellet is not particularly limited and may be cylindrical, spherical, or ellipsoidal. The size is also not particularly limited and can be appropriately selected according to the shape. For example, in the case of spherical pellets, the diameter may be 1 to 10 mm. In the case of ellipsoidal pellets, the major axis may be about 1 to 10 mm and the aspect ratio may be about 0.1 to 1.0. In the case of cylindrical pellets, the diameter may be about 1 to 10 mm and the height may be about 1 to 10 mm.

[0076] 2. Method for producing recycled resin compositions The method for manufacturing the recycled resin composition according to this embodiment is: A process of preparing a recycled resin mixture containing a first recycled resin with a melting point of 200°C or less and a second recycled resin with a melting point exceeding 200°C, A method for producing a recycled resin composition, comprising the step of mixing the recycled resin mixture with a reactive compatibilizer, The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:1. The content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less, based on the total mass of the recycled resin composition.

[0077] The step of preparing a recycled resin mixture containing a first recycled resin and a second recycled resin may be replaced with the preparation of a mixture containing the recycled resin mixture. The mixture containing the recycled resin mixture may be prepared by sorting the resin waste materials so that the mass ratio of the first recycled resin to the second recycled resin is a predetermined ratio, or by adjusting the mixing ratio of each resin waste material.

[0078] The resin waste used in the above preparation process may be pre-crushed into chips (several centimeters to several millimeters in diameter) using a crusher or the like to facilitate melting and processing, or it may be pelletized using known methods.

[0079] Furthermore, known methods can be used to adjust the above ratio. For example, the resin waste material may be sorted by visual inspection, by specific gravity, by electrostatic charge, or by X-ray or light absorption.

[0080] The method for mixing the recycled resin mixture and the reactive compatibilizer is not particularly limited, but may be, for example, by melt kneading. All components may be mixed before melt kneading, or some components may be melt kneaded first and the remaining components kneaded afterward. The apparatus for melt kneading is not particularly limited, and general extruders, kneaders, Banbury mixers, etc., can be used. In particular, from the viewpoint of obtaining a resin composition with a uniform composition, kneading with a twin-screw kneader is preferable.

[0081] 3. Recycled resin molded products The recycled resin molded article according to this embodiment is molded using the recycled resin composition described above by a known method.

[0082] The shape and application of the recycled resin molded article are not particularly limited and can be used in films, sheets, containers (such as food containers), daily necessities, automotive parts, electrical and electronic components, and various consumables. For example, the molded article obtained from the recycled resin composition according to this embodiment is suitable as a film-like molded article because it is easy to obtain a good appearance.

[0083] Furthermore, from the viewpoint of easily obtaining the above-mentioned good appearance, it is preferable to use a thin film-like molded body. The thickness of the molded body is preferably 100 μm or less, and more preferably 15 μm or more and 100 μm or less. If it is 15 μm or more, sufficient strength can be ensured when molding the molded body, and moldability can be improved. If it is 100 μm or less, the weight of the molded body can be reduced, the amount of material used can be reduced, and it becomes easier to obtain a good appearance.

[0084] 4. Method for manufacturing recycled resin molded products The molded article according to this embodiment is molded using the above resin composition by a known method, but may also be molded by melting.

[0085] The molding method is not particularly limited and may include any of the following: inflation molding, extrusion molding, injection molding, foam injection molding, injection compression molding, blow molding, press molding, calendering, vacuum forming, etc., but inflation molding is preferably used.

[0086] When molding a molded product by melting it, the melting temperature is preferably above the melting point of the first recycled resin used (for example, 150°C or higher in the case of polyethylene-based resins) and 200°C or lower. By setting these conditions, the formation of defects due to foreign matter such as dirt and impurities contained in the recycled resin mixture is suppressed, the moldability is improved, foreign matter is less likely to bleed out onto the surface of the molded product, and a molded product of good quality is more likely to be obtained. [Examples]

[0087] The present invention will be described in detail based on examples, but the present invention is not limited to these examples.

[0088] 1. Preparation of materials The following materials were used to prepare the resin compositions for each example and comparative example.

[0089] 1-1. First recycled resin with a melting point of 200°C or less • Recycled LLDPE (manufactured by Asei Shoji Co., Ltd., MFR 1.37g / 10min [190℃, 2.16kg]) • Recycled HDPE (manufactured by Chiyo Environmental Resources Co., Ltd., MFR 0.45g / 10min [190℃, 2.16kg])

[0090] 1-2. Second type of recycled resin with a melting point exceeding 200°C Recycled PET

[0091] 1-3. Reactive compatibilizers • BF-2C: Bondfast 2C (a copolymer of ethylene and glycidyl methacrylate, with a glycidyl methacrylate content of 6% by mass) • BF-E: Bondfast E (a copolymer of ethylene and glycidyl methacrylate, with a glycidyl methacrylate content of 12% by mass) • BF-CG5001: Bondfast CG5001 (a copolymer of ethylene and glycidyl methacrylate, with a glycidyl methacrylate content of 19% by mass) • BF-7M: Bondfast 7M (a copolymer of ethylene, glycidyl methacrylate, and methyl acrylate; glycidyl methacrylate content 6% by mass, methyl acrylate content 27% by mass) (The above products are manufactured by Sumitomo Chemical Co., Ltd., and "BondFirst" is a registered trademark of the company.)

[0092] 1-4. Other ingredients • Lubricant: Amid AP-1 (manufactured by Mitsubishi Chemical Corporation) • Antioxidant 1 (phenolic antioxidant, manufactured by ADEKA) • Antioxidant 2 (Phosphate-based antioxidant, manufactured by ADEKA)

[0093] 1-5. Virgin resin used in the reference example Virgin LLDPE Virgin PET

[0094] 2. Preparation of recycled resin composition [Examples 1-14, Comparative Examples 1-17, Reference Examples 1-3] (Preparation of recycled resin composition pellets) Each component was fed into a Parker HK-25D co-rotating twin-screw compounding extruder (φ25mm, L / D=41) in the mass ratios shown in Tables 1 to 5. After melt-mixing at a cylinder temperature of 280°C, the mixture was extruded into strands. The extruded resin composition was then cooled and cut to obtain resin pellets.

[0095] 3. Evaluation The pellets obtained from Examples 1-14, Comparative Examples 1-17, and Reference Examples 1-3 were evaluated as follows.

[0096] 3-1. Molding suitability at low temperatures Each pellet was molded (to a thickness of 30 μm) using an inflation film extrusion line (60 mm circular die, 1.2 mm die gap, 30 mm screw diameter, L / D ratio = 30). The film was processed with a BUR (blow-up ratio) of 2.5. In the extruder, the temperature in each section was set to 180°C to 200°C, and the rotation speed was maintained at 20 rpm. The moldability at this time was evaluated according to the following criteria. A score of B or higher was considered acceptable.

[0097] (Judgment criteria) A: After extrusion from the die, no malfunctions occur for a long period of time until the molding is complete, allowing for stable and continuous molding. B: No malfunctions occurred for a certain period of time between the time of extrusion from the die and the completion of molding, so there are virtually no problems with continuous molding. C: After extrusion from the die, holes or other defects may occur between the time of extrusion and the completion of molding, making stable and continuous molding impossible. D: After being extruded from the die, the material was extremely unstable and impossible to mold.

[0098] 3-2. Tensile Strength Each film obtained in the above moldability test was subjected to a tensile test in accordance with JIS K 7161-1:2014, and the maximum stress was defined as the tensile strength. For comparative examples that received a C or D rating in the low-temperature moldability evaluation, the films were evaluated after raising the temperature of each section of the extruder to a moldable temperature.

[0099] 3-3. Appearance For each film obtained in the above molding suitability test, the appearance was evaluated using the film of Reference Example 1 as a reference. For comparative examples that received C or D ratings in the low-temperature molding suitability evaluation, the films were evaluated after raising the temperature of each section of the extruder to a moldable temperature.

[0100] (Judgment criteria) A: The film has the same appearance as the film in Reference Example 1. B: The appearance is slightly inferior to the film in Reference Example 1 (but there are no problems in actual use). C: The appearance is significantly inferior to that of the film in Reference Example 1.

[0101] 3-4. Evaluation Results The evaluation results for Examples 1-14, Comparative Examples 1-17, and Reference Examples 1-3 are shown in Tables 1-5.

[0102] [Table 1]

[0103] [Table 2]

[0104] [Table 3]

[0105] [Table 4]

[0106] [Table 5]

[0107] As shown in Tables 1-5, when the first recycled resin, the second recycled resin, and the reactive compatibilizer are included in predetermined ratios (comparison between examples and comparative examples), it can be seen that the mechanical strength (tensile strength) and moldability at low temperatures (below 200°C) are excellent, and a good appearance can be obtained as a molded article. [Industrial applicability]

[0108] According to the present invention, a recycled resin composition having good mechanical strength and excellent moldability at low temperatures, a recycled resin molded article, and a method for producing a recycled resin composition can be provided using a recycled resin composition comprising a first recycled resin and a second recycled resin. Therefore, even when the first recycled resin and the second recycled resin cannot be completely separated from the resin waste material, for example, the recycled resin can be effectively utilized.

Claims

1. A first recycled resin with a melting point of 200°C or less, A second recycled resin with a melting point exceeding 200°C, Reactive compatibilizer, A recycled resin composition comprising, The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:

1. The content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less, based on the total mass of the recycled resin composition. Recycled resin composition.

2. The first recycled resin includes polyethylene resin and / or polypropylene resin, The second recycled resin includes a polyester resin and / or a polystyrene resin. The recycled resin composition according to claim 1.

3. The reactive compatibilizer comprises an ethylene / glycidyl (meth)acrylate copolymer. The recycled resin composition according to claim 1.

4. The content ratio of structural units derived from glycidyl (meth)acrylate to the total mass of the reactive compatibilizer is 5% by mass or more and 13% by mass or less. The recycled resin composition according to claim 3.

5. The content ratio of structural units derived from glycidyl (meth)acrylate to the total mass of the reactive compatibilizer is 5% by mass or more and 7% by mass or less. The recycled resin composition according to claim 4.

6. A recycled resin composition comprising the one described in any one of claims 1 to 5, Recycled resin molded product.

7. It is in the form of a film with a thickness of 100 μm or less. The recycled resin molded article according to claim 6.

8. A step of preparing a recycled resin mixture containing a first recycled resin with a melting point of 200°C or less and a second recycled resin with a melting point exceeding 200°C, A method for producing a recycled resin composition, comprising the step of melt-kneading the recycled resin mixture and a reactive compatibilizer, The mass ratio of the first recycled resin to the second recycled resin is 75:25 to 99:

1. The content of the reactive compatibilizer is 0.1% by mass or more and 10.0% by mass or less, based on the total mass of the recycled resin composition. A method for producing recycled resin compositions.

9. A method for producing a recycled resin molded article by melting and molding a recycled resin composition according to any one of claims 1 to 5, The melting temperature when melting and molding is 200°C or lower. A method for manufacturing recycled resin molded products.

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