TW202403026A - Multilayered resin molded body recovery pretreatment agent and pretreatment method for multilayered resin molded body recovery - Google Patents

Abstract

Provided is a multilayered resin molded body recovery pretreatment agent that can prevent contamination of a resin film by printing ink in multilayered resin molded body recovery pretreatment. A multilayered resin molded body recovery pretreatment agent containing a polar solvent (A) having an SP value of 9-13, a quaternary ammonium salt (B) represented by general formula (1), and a nonionic surfactant having an HLB of 11.0-14.0 and/or an anionic surfactant having a C13 or higher fatty acid group (C).

Description

Treatment agent before recycling of multi-layered resin molded articles and treatment method before recycling of multi-layered resin molded articles

The invention relates to a pre-treatment agent for recycling multi-layer resin molded objects and a pre-treatment method for recycling multi-layer resin molded objects.

In order to meet the required performance as packaging materials, many laminated films composed of different types of materials have appeared on the market. However, since films with different properties are laminated, it is difficult to separate these materials, and accordingly, it becomes difficult to recycle materials used to protect the global environment and the like.

In order to solve this problem, a process has been studied in which the multi-layer film is immersed in a treatment solution to dissolve specific layers such as the adhesive layer, thereby separating the multi-layer film into each constituent resin (for example, Patent Document 1, 2).

One of the problems in such separation is contamination of the recovered resin film caused by printing ink. That is, packaging materials are often additionally printed for display or decoration purposes such as product names. When the multi-layer film subjected to such printing is separated and recovered, the printing ink will be included in the treatment liquid. This kind of printing ink component easily adheres to the recycled resin. This causes resin contamination and becomes a big problem when reusing resin.

Patent Document 1 discloses the use of A method for recovering laminated membranes from phosphonium liquid. However, in those containing more than 6% In the case of chlorine, the aqueous solution becomes harmful substances, making the operation highly dangerous and requiring special management of the aqueous solution.

Patent Document 2 discloses a method of recovering a multi-layer film having a printing layer using a sodium hydroxide aqueous solution. However, the aqueous solution in this document cannot prevent the re-adhesion of ink, and only shows a peeling effect on multi-layer films containing aluminum, alumina and silicon dioxide, and has limited use. [Prior technical literature] [Patent Document]

Patent Document 1: International Publication 2020/059516 Patent Document 2: Japanese Patent Application Laid-Open No. 2020-175620

[Problem to be solved by the invention]

The object of the present invention is to provide a pre-treatment agent for the recycling of multi-layer resin molded objects that can prevent contamination of the resin film caused by printing ink during the pre-processing of recycling the multi-layer resin molded objects. [Technical means to solve the problem]

The present invention is a pre-treatment agent for recycling multi-layered resin molded articles, which is characterized in that it contains a polar solvent (A) with an SP (Solubility Parameter) value of 9 to 13, and a quaternary ammonium salt represented by the following general formula (1) (B), and a nonionic surfactant with an HLB (Hydrophilic-Lipophilic Balance) of 11.0 to 14.0 and/or an anionic surfactant having a fatty acid group with a carbon number of 13 or more (C). (In the formula, R ₁ to R ₄ are the same or different, and are aliphatic hydrocarbon groups with 1 to 6 carbon atoms that may have hydrogen or 1 hydroxyl group)

In the pretreatment agent for recycling multi-layered resin molded articles of the present invention, the water content is preferably 5% by mass or more. The above-mentioned polar solvent is preferably selected from the group consisting of ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone (NMP), isopropyl alcohol, dimethylformamide (DMF), dimethylsulfoxide (DMSO) ), and at least one of the group consisting of phenyl glycol.

The quaternary ammonium salt preferably has a pH of 11.5 or more when it is a 1% by mass aqueous solution. The above (C) is preferably oleate and/or polyethylene glycol monooleate.

Furthermore, the present invention is a treatment method before recycling of multi-layered resin molded articles, which is characterized by the step of immersing the multi-layered resin molded articles having a printed layer in any of the above-mentioned pre-treatment agents for recycling multi-layered resin molded articles. [Effects of the invention]

By using the multi-layered resin molded article recycling pre-treatment agent of the present invention to dissolve only part of the layers such as the adhesive layer and EVOH (Ethylene vinyl alcohol copolymer, ethylene-vinyl alcohol copolymer) layer from the multi-layered resin molded article, recycling can be achieved When constituting the resin component of the multi-layered resin molded article, the printing ink component is prevented from adhering to the recovered resin.

The invention is a pre-treatment agent for recycling multi-layered resin molded bodies, which is characterized in that it contains a polar solvent (A) with an SP value of 9 to 13, a quaternary ammonium salt (B), and a nonionic solvent with an HLB of 11.0 to 14.0. Surfactant and/or anionic surfactant (C) having a fatty acid group with a carbon number of 13 or more.

This kind of pre-treatment agent for recycling multi-layered resin molded articles can separate the multi-layer film into each layer by using a polar solvent and a quaternary ammonium salt to dissolve part of the multi-layer structure such as the adhesive and EVOH resin in the resin. During this dissolution, the printing layer will also be compatible and dispersed, resulting in the presence of printing ink components in the treatment liquid. This kind of ink component has low affinity for solvents and is insoluble even in water. Therefore, it is easy to re-attach to the separated resin components during flushing.

The pretreatment agent for recycling multi-layered resin molded articles of the present invention can increase The compatibility and dispersion properties of this kind of printing ink component in the treatment liquid greatly inhibit the adhesion to the separated resin component.

By using a polar solvent with a specific SP value, the adhesive layer and EVOH can be dissolved, thereby promoting the dissolution of the adhesive layer and EVOH existing between the layers of the multi-layered resin molded article. In addition, by using a quaternary ammonium salt, the dissolution of the adhesive layer and EVOH can be accelerated. Furthermore, by using these together, the permeability of the pretreatment agent for recycling the multi-layer resin molded article between the layers of the multi-layer resin molded article becomes good, and the adhesive layer and EVOH existing between the layers can be fully dissolved.

The SP value of the polar solvent used in the present invention needs to be 9 to 13. The SP value (solubility parameter (δ)) is a value defined by the normal solution theory introduced by Hildebrand, and is determined by the square root of the heat of evaporation required to evaporate 1 cm ³ of liquid (cal/cm ³ ) ^1/2 calculate. In the present invention, by using a polar solvent with an SP value within this range, it is helpful for the organic alkaline compound in the pretreatment agent for recycling the multi-layered resin molded body to react with the adhesive layer existing between the layers of the multi-layered resin molded body. , EVOH plays a role and can fully dissolve them. The SP value of the polar solvent used in the present invention is preferably 10 or more. On the other hand, the SP value is preferably 12 or less.

Specific examples of the polar solvent having the above SP value include diethylene glycol monobutyl ether (SP value: 9.0), N-methyl-2-pyrrolidone (NMP) (SP value: 11.2), isopropyl Propanol (SP value: 11.5), dimethylformamide (DMF) (SP value: 11.9), dimethylsulfoxide (DMSO) (SP value: 12.0), benzyl alcohol (SP value: 10.8), benzene Ethylene glycol (SP value: 12.4), etc. These may be used individually, or 2 or more types may be used together. Among them, NMP is preferred.

The quaternary ammonium salt (B) used in the present invention is a compound represented by the following general formula (1).

(In the formula, R ₁ to R ₄ are the same or different, and are aliphatic hydrocarbon groups with 1 to 6 carbon atoms that may have hydrogen or 1 hydroxyl group)

Furthermore, if a hydrocarbon group having a carbon number of more than 7 is used as R ₁ to R ₄ , the properties as a cationic surfactant become stronger, which is unfavorable in this regard.

In the present invention, the quaternary ammonium salt (B) is a component used to dissolve the adhesive. In the present invention, by using (C) described in detail below as a surfactant, adhesion of ink is prevented. Therefore, it is more preferable that the quaternary ammonium salt (B) has no properties as a cationic surfactant.

When the above-mentioned quaternary ammonium salt (B) is a 1% by mass aqueous solution, the pH is preferably 11.5 or more. If the pH is within this range, it has the advantage that the adhesive can be dissolved.

Specific examples of the quaternary ammonium salt used in the present invention include: dimethylbis(2-hydroxyethyl)ammonium hydroxide (the above-mentioned pH 12.3), monomethyltris(2-hydroxyethyl) Ammonium hydroxide (the above-mentioned pH 12.1), trimethyl-2-hydroxyethylammonium hydroxide (the above-mentioned pH 12.5), tetraalkyl ammonium hydroxide with a pH of 11.5 or more in 1 mass % aqueous solution (as an example, Tetramethylammonium hydroxide (above pH 12.9)), etc. Among them, dimethylbis(2-hydroxyethyl)ammonium hydroxide and the like are preferred.

Furthermore, the pretreatment agent for recycling multi-layered resin molded articles of the present invention contains a specific surfactant. By containing surfactants, printing ink remaining in multi-layered resin molded objects such as films can be made compatible and dispersed. Thereby, the printing ink will not contaminate the recovered resin, which is better in this aspect.

The above-mentioned surfactant is a nonionic surfactant with an HLB of 11.0 to 14.0 and/or an anionic surfactant (C) having a fatty acid group with a carbon number of 13 or more. That is, by using a surfactant having specific emulsifying ability, the object of the present invention can be better achieved. In addition, in the present invention, HLB is a value defined by the following calculation formula based on Griffin's method. HLB value=20×[sum of chemical formula weights of hydrophilic parts]/molecular weight

Examples of nonionic surfactants include: polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether and other ether types; Glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyglycerol fatty acid ester, propylene glycol fatty acid ester and other ester types; Polyoxyethylene glycerol fatty acid ester, polyoxyethylene castor oil, polyoxyethylene hardened castor oil, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol sorbitan fatty acid ester, polyethylene glycol fatty acid ester, etc. Ester ether type etc. Among them, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, etc. are preferred.

Among the various nonionic surfactants mentioned above, those with an HLB of 11.0 to 14.0 are preferred. The above-mentioned HLB is more preferably 11.5 to 13.5.

Examples of the anionic surfactant include alkali metal salts, ammonium salts, quaternary ammonium salts, and the like of fatty acids having 13 or more carbon atoms that can be uniformly dissolved in the present composition. The carbon number of the above-mentioned fatty acid is more preferably 14 or more. The upper limit of the carbon number of the fatty acid is not particularly limited, but is preferably 30 or less.

Specific examples of the fatty acid having a carbon number of 13 or more include: oleic acid (carbon number 18), stearic acid (carbon number 18), palmitic acid (carbon number 16), myristic acid (carbon number 16) 14), linoleic acid (carbon number 18), etc. Moreover, it may be a saturated fatty acid or an unsaturated fatty acid, and it is especially preferable to use an unsaturated fatty acid. More specifically, it is best to use oleic acid.

In addition, one type of the above-mentioned surfactant may be used, or two or more types may be used in combination. In addition, the content of the surfactant in the pretreatment agent for recycling multi-layered resin molded articles is preferably 0.1 to 5% by mass.

The pretreatment agent for recycling multi-layered resin molded articles of the present invention is preferably used in the form of an aqueous solution. The water content in the aqueous solution of the pre-treatment agent for recycling multi-layered resin molded articles is preferably 5% by mass or more. More preferably, it is 10 mass % or more. On the other hand, the upper limit is preferably 40 mass%, more preferably 30 mass%. If the water content is within the above range, a uniform state can be maintained when mixed into a solution, and good solubility of the adhesive and EVOH can be demonstrated.

In the aqueous solution of the pre-treatment agent for recycling multi-layered resin molded articles, the content of the polar solvent is preferably 50 to 90% by mass. The lower limit of the content is more preferably 60% by mass, and still more preferably 65% by mass. On the other hand, the upper limit of the content is more preferably 80% by mass, and still more preferably 75% by mass.

The content of the above-mentioned quaternary ammonium salt in the aqueous solution of the pre-treatment agent for recycling multi-layered resin molded bodies is preferably 1 to 20 mass%. The lower limit of the content is more preferably 3% by mass, and still more preferably 5% by mass. On the other hand, the upper limit of the content is more preferably 18% by mass, and still more preferably 15% by mass.

Moreover, the ratio between the above-mentioned polar solvent and the quaternary ammonium salt is preferably 20:1 to 5:1 (mass ratio).

The pre-treatment agent for recycling multi-layered resin molded articles of the present invention may further contain a compatibilizer. The composition containing each of the above components may not be completely homogeneous depending on the composition, and may separate when left to stand. In this case, a compatibilizer can be blended to make the components compatible.

The above-mentioned compatibilizer is used to uniformly mix the polar solvent, quaternary ammonium salt and water contained in the present composition when it is difficult to uniformly mix these components. If it is of this nature, there is no particular limitation. Specifically, for example, polyoxyalkyl ether, coconut oil fatty acid diethanolamide, etc. can be used as the nonionic surfactant, and sodium alkylbenzenesulfonate, sodium p-toluenesulfonate, etc. can be used as the anionic surfactant. Furthermore, when a nonionic surfactant is used as the compatibilizer, the surfactant that can be used as the component (C) is not equivalent to the compatibilizer. Here, the HLB of the nonionic surfactant used as a compatibilizer is preferably more than 14.0 and 20.0 or less.

When the above-mentioned compatibilizer is contained in the pre-treatment agent for recycling multi-layered resin molded articles of the present invention, its content is preferably 0.1 to 20% by weight relative to the total amount of the treatment agent. By setting the content of the compatibilizer within this range, the above object can be achieved. The lower limit is preferably 1.0% by weight, more preferably 2.0% by weight.

In the present invention, the target multi-layered resin molded article is not particularly limited, and examples include packaging films and sheets, packaging materials such as packaging containers, fuel tanks such as gasoline, hoses for refrigerant transportation, optical materials, etc. Frequently used users. The shape is not particularly limited, and examples include hollow bodies, films, and the like.

These multi-layer resin molding systems are multi-layer bodies composed of two or more resin layers. Generally, it can be a complex composed of an olefin-based resin layer such as polyethylene and polypropylene, a polyester resin layer such as polyethylene terephthalate, polyethylene naphthalate, and a polyamide-based resin layer as structural units. layer resin molded body.

When the laminated resin molded article is a laminated film, use unstretched polyethylene (PE) resin film, unstretched polypropylene (CPP) resin film, cyclic polyolefin (COP or COC) resin film, or unstretched polyethylene (PE) resin film. Olefin film group composed of co-extruded film of polyethylene and unstretched polypropylene (PE/CPP), polyethylene terephthalate (PET) resin film, polyamide (PA) resin film, polynaphthalene Ethylene diformate (PEN) resin film, polyacrylonitrile (PAN) resin film, polycarbonate (PC) resin film, polyimide (PI) resin film, polyvinyl chloride (PVC) resin film, etc. In the present invention, any one can be used.

In addition, the resin molded article or multi-layered film having an EVOH layer may be a multi-layered article of three or more layers formed by combining EVOH as an intermediate layer with two or more of the above-mentioned resins.

EVOH is usually a resin obtained by copolymerizing ethylene and a vinyl ester monomer and then saponifying it. Vinyl acetate is generally used. As the polymerization method, any known polymerization method such as solution polymerization, suspension polymerization, and emulsion polymerization may be used. However, solution polymerization using methanol as a solvent is generally used. The obtained ethylene-vinyl ester copolymer can also be saponified by a known method. This kind of EVOH is mainly composed of ethylene structural units and vinyl alcohol structural units and contains a certain amount of vinyl ester structural units that remain unsaponified.

In the present invention, the EVOH preferably has an ethylene unit content of 3 to 70 mol%, and more preferably 25 to 50 mol%. The ethylene unit content can be determined by ¹ H-NMR measurement, for example.

The degree of saponification of the vinyl ester component in EVOH is not particularly limited as long as it does not affect the gas barrier properties that are EVOH characteristics.

Furthermore, EVOH may further contain structural units derived from comonomers shown below. Examples of the comonomer include propylene, isobutylene, vinyl acetate, α-olefins such as α-octene, α-dodecene, and α-octadecene, 3-butene-1-ol, and 4-pentene. Hydroxyl-containing α-olefins such as en-1-ol, 3-butene-1,2-diol and their esterified products, chelates and other hydroxyl-containing α-olefin derivatives; unsaturated carboxylic acids or their salts, Partial alkyl ester, complete alkyl ester, nitrile, amide, anhydride; unsaturated sulfonic acid or its salt; vinyl silane compound; vinyl chloride, styrene and other comonomers. Furthermore, it may also be an EVOH-based resin that has been "post-modified" such as amine esterification, acetalization, cyanoethylation, and oxyalkylation.

Furthermore, the multi-layered resin molded article may have layers other than resin such as a metal foil layer. In food packaging containers, standing pouches for toiletry products, laminated tubes, and pharmaceutical packaging materials, metal layers such as aluminum foil layers are widely used to improve gas barrier properties. Multi-layered resin molded body. In such a multi-layered resin molded article, similarly, if the multi-layered resin molded article recovery pretreatment agent of the present invention is used, the metal foil layer can be dissolved and removed, and the resin layer can be separated. When processing such a multi-layered resin molded article, it is preferable in that the metal foil layer can be dissolved and removed, and the resin layer containing no metal component can be reused.

Furthermore, this treatment agent can also be used to treat multi-layered resin molded bodies having evaporated layers of aluminum, alumina, silica, etc. It is known that many packaging containers and the like have such vapor-deposited layers. When regenerating such multi-layered laminates, the pretreatment agent for recycling multi-layered resin molded articles of the present invention can be suitably used.

The composition and formation method of the above-mentioned vapor deposition layer are not particularly limited. The vapor deposition layer is preferably composed of an amorphous (amorphous) layer. Furthermore, from the viewpoint of visible light transmittance, alumina and/or silica are preferred. In order to form it into a form showing light-shielding properties, aluminum is preferred. The release layer (A) may have two or more vapor deposition layers. When there are two or more evaporated layers, each layer may have the same composition or different compositions. Furthermore, when there is a detachment layer (A) including a vapor deposition layer, the detachment layer also functions as an oxygen and/or water vapor barrier layer before detachment using an alkaline aqueous solution.

The evaporated layer composed of alumina and silicon dioxide is preferably in a form containing Al ₂ O ₃ and SiO ₂ respectively. For example, when alumina is expressed as AlO _n and silicon dioxide is SiO _n , the value of n may be in the range of 0.5 to 1.5 for alumina and 1 to 2 for silicon dioxide. Forms of alumina and silicon dioxide other than Al ₂ O ₃ and SiO ₂ are not excluded. On the other hand, from the viewpoint of light-shielding properties, the vapor-deposited layer made of aluminum is preferably a vapor-deposited film substantially made only of aluminum. The film thickness of the vapor-deposited film composed of at least one selected from the group consisting of aluminum, alumina, and silicon dioxide should be in the range of 1 to 400 nm, preferably in the range of 5 to 300 nm, and more preferably It is in the range of 10~200 nm.

In the case of an aluminum vapor deposition layer, the film thickness is preferably 5 to 300 nm, more preferably 10 to 100 nm, and further preferably 10 to 60 nm. Moreover, in the case of a vapor-deposited layer of aluminum oxide and/or silicon dioxide, the film thickness is preferably 5 to 300 nm, more preferably 10 to 100 nm, and still more preferably 10 to 60 nm. The film thickness of the vapor-deposited film can be measured according to the Fundamental Parameter method by using a fluorescence X-ray analyzer (model name: EA6000VX, EA8000) manufactured by Hitachi High-Tech Science Co., Ltd., for example.

In addition, the above-mentioned multi-layered resin molded article may be one in which each layer is bonded with an adhesive. Examples of the adhesive include commonly used polyurethane adhesive compositions. These adhesives are dissolved by the quaternary ammonium salt in the pretreatment agent for recycling multi-layered resin molded articles of the present invention.

The above-mentioned multi-layered resin molded article preferably further has a printed layer. Since the pre-treatment agent for recycling multi-layered resin molded objects of the present invention makes it difficult for printing ink to adhere to the surface of the recovered resin, etc., it can be particularly suitably used for treating molded objects having a printing layer.

The above-mentioned printing layer refers to one formed by printing ink, and can preferably be listed as: screen ink (screen ink), gravure ink (gravure ink), quick-drying ink (flexographic ink), ink jet ink (ink jet ink), offset plate Ink (offset ink) and other printing inks. Among them, gravure ink, quick-drying ink, and inkjet ink are preferably used, and gravure ink and/or quick-drying ink is more preferably used.

Preferable examples of the binder resin contained in the printing layer include polyurethane resin, cellulose resin, polyamide resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-acrylic copolymer resin, and the like. Vinyl resin, chlorinated polyolefin, ethylene vinyl acetate copolymer, chlorinated ethylene vinyl acetate copolymer, rosin resin, ethylene-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, cyclized rubber, chlorinated rubber, butyl Aldehydes, polyacetal resins, petroleum resins, and their modified resins, etc. These resins can be used individually or in mixture of 2 or more types.

Among the above, it is preferable to contain at least one adhesive selected from the group consisting of polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, polyamide resin, acrylic resin, polyester resin, rosin resin and cellulose resin. agent resin. Furthermore, it is preferable that the total mass of the binder resin contains at least 50% by mass of a polyurethane resin and a vinyl chloride-vinyl acetate copolymer resin, a polyamide resin and a cellulose resin, or an acrylic resin and a cellulose resin. For the binder resin composed of two resins combined, the mass ratio of the former to the latter is preferably 95:5 to 30:70.

The above-mentioned printing layer preferably contains a colorant. As the coloring agent, pigments are preferred. For example, preferred organic pigments include soluble azo-based pigments, insoluble azo-based pigments, azo-based pigments, phthalocyanine-based pigments, halogenated phthalocyanine-based pigments, anthraquinone-based pigments, anthrone-based pigments, and dianthraquinone-based pigments. , anthrapyrimidine series, perylene series, perinone series, quinacridone series, thioindigo series, dioxins series, isoindolinone series, quinophthalone series, azomethine-azo series, flavanthrone series, diketopyrrolopyrrole pigments such as isoindoline, indanthrene, and carbon black pigments, but are not limited to the above examples. For example, preferred examples include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazole orange, carmine FB, and cromophtal yellow. , Gumei red, phthalocyanine blue, phthalocyanine green, two Purple, quinacridone magenta, quinacridone red, indanthryne blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, pyrenone orange, isoindolinone yellow yellow), aniline black, diketopyrrolopyrrole red, daylight fluorescent pigments, etc. In addition, CI pigments described in the dye index (color index) can be used appropriately.

The pre-treatment method for recycling multi-layer resin molded articles of the present invention is a method of applying the pre-treatment agent for recycling multi-layer resin molded articles of the present invention to the multi-layer resin molded article and extracting the adhesive layer and EVOH. For example, a suitable method is a method of immersing the multi-layer resin molded article in the above-mentioned pre-treatment agent solution for recycling the multi-layer resin molded article.

The form of the above-mentioned multi-layered resin molded body can be set arbitrarily. The molded body can be directly impregnated, or the molded body can be transformed into small pieces, granules, etc. by appropriate crushing, pulverization, etc., and then impregnated.

In addition, the temperature of the solution during the pre-treatment of recycling the laminated film can be normal temperature, preferably 60 to 100°C. Moreover, an autoclave etc. can also be used for processing. In addition, when performing the pretreatment for recovering the multilayer film, it is appropriate to stir or apply vibration to the solution in which the multilayer resin molded body is impregnated.

By using the multi-layered resin molded article recovery pre-treatment agent of the present invention, the adhesive, EVOH, etc. in the multi-layered resin molded article are selectively dissolved, so that the other layers constituting the multi-layered resin molded article are separated into independent states. disintegrate.

The resin components recovered and separated in this way can be reused as materials and directly used as recycled resin. Furthermore, the polymer may be subjected to chemical treatment to become a raw material, and the raw material may be used as a raw material for chemical recovery for reuse as a polymer raw material. For example, when the polyamide resin is recycled, the polyamide resin can be decomposed into monomers and then utilized.

Furthermore, the pre-treatment method for recycling multi-layered resin molded articles of the present invention may also include a step of distilling water and/or polar solvents from the residual liquid after pre-treatment. The above-mentioned distillation may be carried out by using general equipment and in accordance with general methods, and the conditions may be appropriately set.

In the above distillation step, even when the boiling point of the polar solvent in the pre-treatment agent for recycling multi-layered resin molded articles is equal to or lower than the boiling point of water, it is sometimes difficult to remove it due to the presence of quaternary ammonium salts. Polar solvents. Thus, during the distillation step, this polar solvent remains to some extent while the water is removed.

Furthermore, the pre-treatment method for recovering the multi-layered resin molded article may include a step of adding a polar solvent and/or water to the residue obtained in the above-mentioned distillation step. That is, by adding a polar solvent and/or water to the residue obtained by distillation and adjusting the mixing ratio of each, it can be used as a pre-treatment agent for recycling multi-layered resin molded bodies and can be used as a pre-treatment agent for recycling multi-layered membranes.

After the pre-treatment of the laminated film is carried out according to the present invention, the separated laminated film can be separated into the resin components constituting each layer of film by known methods, and then each resin can be reused.

In this way, according to the present invention, each component constituting the multi-layer film can be regenerated and reused, thereby contributing to the protection of the global environment and the like. [Example]

Hereinafter, this invention is demonstrated concretely based on an Example. In addition, this invention is not limited to the following Example. In the examples, in the case of "parts" and "%", unless otherwise specified, it means "parts by mass" and "% by mass".

[Examples 1 to 6, Comparative Examples 1 to 10] A pretreatment agent for recycling multi-layered resin molded articles containing each of the components (A) to (C) in the ratio shown in Table 1 was prepared. The obtained pre-treatment agent for recovery of each multi-layered resin molded article is used to perform pre-treatment for recovery of the multi-layered resin molded article. This processing is performed under the following conditions. Furthermore, the multi-layer resin molding system used in this process has a multi-layer resin molded body composed of polyamide/printing layer/adhesive layer/polyethylene.

(Methods for pre-recycling treatment of multi-layered resin molded articles) The procedures and methods for obtaining a polyamide-based resin composition and a polyolefin-based resin composition by separation and regeneration from a multi-layered resin molded body using a release agent are as follows. First, the multi-layered resin molded body is cut with a crusher to produce fluff. Secondly, under normal pressure and heating conditions, the fluff is immersed in the release agent and stirred to dissolve, compatibility and disperse the adhesive layer, printing layer, various resins, etc. The temperature and time of immersion and stirring are preferably 1 to 5 days, and more preferably 2 to 4 days under conditions of 20°C or higher and less than 60°C. Under conditions above 60°C, 1 to 5 hours is preferred, and 2 to 4 hours is more preferred. Thereafter, the resin composition insoluble in the release agent is taken out and washed with water or the like to remove the release agent. The resin composition contains polyamide resin fluff and polyolefin resin fluff that are insoluble in the release agent. Thereafter, for example, using water, the resin composition is stirred in the water at 25° C. and left to stand, thereby utilizing the difference in specific gravity between the specific gravity of the polyamide resin of 1.00 to 1.25 and the specific gravity of the polyolefin resin of 0.870 to 0.970. , separate the two (separation by difference in specific gravity), and dry them under hot air conditions, etc. Furthermore, when a plurality of types of polyamide-based resins are included in the multi-layered resin molded article, they are all separated as fluff of the polyamide-based resins. When a plurality of types of polyolefin resins are included, they are all separated as fluff of the polyolefin resins in the same manner.

The results of the above processing were evaluated based on the following criteria. (film peelability) ◎: Complete peeling was confirmed very quickly 〇: Complete peeling confirmed △: Although partial peeling was observed, it was not sufficient. ×: No peeling occurred at all

(film anti-staining properties) 〇: Very little coloring of the film △: Coloring is observed on the film ×: Very strong coloring was observed on the film

[Table 1] Example 1 Example 2 Case Example 3 Example 4 Example 5 Example 6 NMP 69 69 28 28 Phenyl glycol 46 46 60 60 Quaternary ammonium salt 7.5 7.5 6.5 6.5 6.5 6.5 Sodium p-toluenesulfonate 15 Coconut Oil Fatty Acid Diethanolamide 20 water 22.5 22.5 18.5 18.5 17.5 12.5 Potassium oleate (carbon number: 18) 1 1 Polyethylene glycol monooleate (HLB: 120) 1 1 1 1 Film peelability ◎ ◎ ◎ ◎ ◎ ◎ Membrane anti-staining properties 〇 〇 〇 〇 〇 〇

[Table 2] Example 7 Example 8 Example 9 Example 10 NMP 28 28 28 28 Phenyl glycol Ethylene glycol monobutyl ether 46 Isopropyl alcohol 46 DMF 46 DMSO 46 Quaternary ammonium salt 6.5 6.5 6.5 6.5 Sodium p-toluenesulfonate Coconut Oil Fatty Acid Diethanolamide water 18.5 18.5 18.5 18.5 Potassium oleate Polyethylene glycol monooleate 1 1 1 1 Film peelability ◎ ◎ ◎ ◎ Membrane anti-staining properties 〇 〇 〇 〇

[table 3] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Comparative example 6 NMP 70 70 28 28 Phenyl glycol 47 47 60 60 Quaternary ammonium salt 7.5 7.5 6.5 6.5 6.5 6.5 Sodium p-toluenesulfonate 15 Coconut Oil Fatty Acid Diethanolamide 20 water 22.5 22.5 18.5 18.5 18.5 13.5 Potassium oleate Polyethylene glycol monooleate Film peelability ◎ ◎ ◎ ◎ ◎ ◎ Membrane anti-staining properties × × × × × ×

[Table 4] Comparative example 7 Comparative example 8 Comparative example 9 Comparative example 10 NMP 69 69 28 28 Phenyl glycol 46 46 Quaternary ammonium salt 7.5 7.5 6.5 6.5 Sodium p-toluenesulfonate Coconut Oil Fatty Acid Diethanolamide water 22.5 22.5 18.5 18.5 Potassium octoate (carbon number 8) 1 1 Polyethylene glycol monooleate (HLB: 17.2) 1 1 Film peelability ◎ ◎ ◎ ◎ Membrane anti-staining properties × × × × In addition, in the above-mentioned Tables 1 to 4, dimethylbis(2-hydroxyethyl)ammonium hydroxide is used as the quaternary ammonium salt.

According to the results of the above-mentioned Examples and Comparative Examples, the pre-treatment agent for recycling multi-layered resin molded articles of the present invention has excellent film peelability, and at the same time, the film anti-coloration performance is also excellent. [Industrial availability]

The present invention can be used for pre-processing when recycling multi-layered resin molded articles. By using the multi-layer film recycling pre-treatment agent of the present invention, the plurality of layers constituting the multi-layer resin molded body can be separated, and the multi-layer film recycling pre-treatment agent of the present invention can be preferably used for the pre-treatment for recycling. .

without

without

Claims (6)

A pre-treatment agent for recycling multi-layered resin molded objects, characterized by containing a polar solvent (A) with an SP (Solubility Parameter) value of 9 to 13, and a quaternary ammonium salt (B) represented by the following general formula (1) , and a nonionic surfactant with an HLB (Hydrophilic-Lipophilic Balance) of 11.0 to 14.0 and/or an anionic surfactant (C) with a fatty acid group with a carbon number of 13 or more, (In the formula, R ₁ to R ₄ are the same or different and are aliphatic hydrocarbon groups having 1 to 6 carbon atoms that may have hydrogen or 1 hydroxyl group). For example, the pre-treatment agent for recycling multi-layered resin molded objects according to claim 1, wherein the water content is 5% by mass or more. The pre-treatment agent for recycling multi-layered resin molded articles of claim 1 or 2, wherein the above-mentioned polar solvent is selected from the group consisting of ethylene glycol monobutyl ether, N-methyl-2-pyrrolidone (NMP), isopropyl alcohol, At least one kind from the group consisting of dimethylformamide (DMF), dimethylsulfoxide (DMSO), and phenyl glycol. The pre-treatment agent for recycling multi-layered resin molded articles according to claim 1 or 2, wherein the pH of the above-mentioned quaternary ammonium salt is 11.5 or above when it is a 1% by mass aqueous solution. The pre-treatment agent for recycling multi-layered resin molded objects according to claim 1 or 2, wherein the above (C) is oleate and/or polyethylene glycol monooleate. A method for pre-recycling treatment of multi-layered resin molded objects, characterized by the step of immersing the multi-layered resin molded object with a printed layer in the pre-recycling treatment agent for multi-layered resin molded objects according to claim 1 or 2.