JP2023170419A - Material for molding or forming and method for manufacturing the same - Google Patents

Abstract

To provide a method by which a laminated film can be easily separated and recovered into a single layer and a printed layer can be easily peeled off when a plastic film is a laminated film made by laminating a plurality of films or a film having the printed layer.SOLUTION: The present invention is a method for manufacturing a material for molding or forming, comprising a process of pulverizing plastic film-derived resin to 1 mm or less. The present invention is also a material for molding or forming containing plastic film-derived resin, which is a material for molding or forming that is crushed to 1 mm or less. The present invention also provides a material for molding or forming containing a plastic film-derived resin, and a weight average molecular weight (Mw2) is 450000 or less.SELECTED DRAWING: None

Description

The present invention relates to a molding or molding material using a resin derived from a plastic film, and a method for producing the same.

Currently, the recycling rate of plastic waste, which is separated and collected, is 9% of the plastic produced worldwide. Of the 91% of plastic that becomes garbage, 12% is incinerated, and 79% is disposed of in landfills or leaks into the environment (Non-Patent Document 1). According to the Plastic Recycling Association and the Ministry of Economy, Trade and Industry's Monthly Report on Production Statistics (November 2020 edition), in Japan, out of 8.5 million tons/year of waste plastic (100%), material recycling is 1.86 million tons/year. (22%), 270,000 tons/year (3%) as chemical recycling, and 7.26 million tons/year (61%) as energy recovery. Furthermore, the recycling rate of PET bottles in Japan is approximately 89% of shipped PET bottles, and 510,000 tons/year are recycled as materials. On the other hand, the recycling rate for packaging film remains at 240,000 tons/year, or approximately 8.5%.

One of the reasons why the recycling rate of packaging films continues to be low is the difficulty of separating and collecting systems for stacked packaging films. In order to recycle plastics, it is necessary to separate and collect waste plastics, which are made up of different types of plastic materials such as polyethylene (PE) and polypropylene (PP), separated by material. However, many plastic products, including laminated films, are made up of different types of plastic materials that are bonded and laminated, making it difficult to separate and collect each material. Therefore, there is a strong need to construct a recycling system that can easily separate and recover waste plastics.

Furthermore, it is difficult to return recycled plastic products to the same product due to cost considerations, and basically each time they are recycled, they deteriorate, so they are forced to be reborn as products of lower quality. One of the reasons why the quality of recycled plastic deteriorates is that ink and pigments are mixed into the plastic as impurities. However, because many plastic products have printing processes applied to their surfaces, it is difficult to remove the color during the recycling process, and as a result, recycled plastic products are colored. Recycled plastics containing such pigments and inks not only have extremely low commercial value due to their coloring, but the reality is that they are only plastics whose physical properties have deteriorated due to impurities. Recycling methods that produce recycled plastic are also needed.

To address these problems, Patent Documents 1 to 3 disclose methods for removing ink from the surface of a roll film that has been subjected to printing processing.

Science Advances 19 Jul 2017:Vol. 3, no. 7, e1700782

Special table 2015-520684 publication Special table 2016-509613 publication Special table 2018-514384 publication

In general, the grade of resin for injection molded products is set to have a lower weight average molecular weight (Mw) and a higher melt flow rate (MFR) due to the required characteristics compared to the grade of resin for films.

Here, when a plastic film is used as a recycling resin, the physical properties of the recycling resin are basically the same as those of the plastic film. For example, Patent Document 1 describes that a plastic film is crushed to 6 to 14 mm to obtain a crushed product derived from the plastic film as a pellet-shaped colorless recycled film. It maintains the physical properties of Therefore, when using a resin derived from a plastic film, since the physical properties of the film grade are maintained as they are, there is no problem when recycling it as a film raw material again. However, when used in molded products by injection molding, etc., the MFR value is low due to the molecular weight being too large, that is, the fluidity during heating is low, so it is not suitable for injection molding. Therefore, plastic film cannot be used as is when recycled. When reusing it, it is necessary to adjust the physical properties by mixing it with other resins, which poses a problem in that it is time-consuming. In addition, it is necessary to mix it with a resin having a high MFR as another resin, and since virgin material is often used as such resin, there is also the problem that the recycling rate ultimately decreases significantly.

In the conventional technology, as described in Patent Documents 1 to 3, only the issue of removing ink from plastic film has been studied, and no attention has been paid to physical properties such as the molecular weight and melt flow rate of recycled resin. .

In addition, in recent years, with the diversification of packaging materials, there has been an increasing demand for high functionality of packaging materials, improved adhesion of ink films to plastic substrates, and high design quality of printed materials. As a result, the types of packaging materials and inks are diversifying, and at the same time, it is becoming more difficult to peel off the ink layer. For example, in a laminated film in which multiple films are laminated, or in a laminate in which a printed layer is provided on the film and then another film is laminated via an adhesive layer, the printed layer is between the multiple films. In the case of (back-printed) laminated films provided in Ink removal becomes more difficult. There is a need for a method that can remove ink from plastic films of various configurations.

Therefore, the problem to be solved by the present invention is to provide a molding or molding material that can process plastic films into various molded products or molded products by changing the physical properties of resin derived from plastic films, and a method for producing the same. It is about providing.

Further, the problem to be solved by the present invention is that when the plastic film is a laminated film made by laminating a plurality of films or a film having a printed layer, the laminated film can be easily separated and recovered into a single layer, The object of the present invention is to provide a method that allows a printed layer to be easily peeled off.

As a result of extensive research in order to solve the above-mentioned problems, the present inventors have discovered that by crushing plastic films, it is possible to reduce the molecular weight of resin derived from plastic films, and to obtain the desired resin grade for the film. We have discovered that it is possible to change the physical properties from the grade required for injection molding to the grade required for injection molding.

That is, the present invention provides a method for producing a molding material or a molding material, which includes a step of pulverizing a resin derived from a plastic film into pieces of 1 mm or less.

The present invention also provides a molding or molding material containing a resin derived from a plastic film, which is a pulverized product of 1 mm or less.

The present invention also provides a molding or molding material containing a plastic film-derived resin and having a weight average molecular weight (Mw2) of 450,000 or less.

According to the present invention, the physical properties of a resin derived from a plastic film can be changed. According to the present invention, it is possible to change the resin grade from the grade required for film to the grade required for injection molding, so that the resin derived from plastic film can be used as is, not only for films but also for injection molded products. It can be processed into various molded products or molded products.

Furthermore, according to the present invention, when the plastic film is a laminated film made by laminating a plurality of films or a film having a printed layer, not only a laminated film in which the printed layer is exposed on the film surface (front printing) but also a laminated film having a printed layer exposed on the film surface. Even in plastic laminates with various configurations, such as laminated films in which the printing layer is provided between multiple films (back printing), the plastic laminate can be separated into single layers, and the ink layer can be separated. Can be easily peeled off. That is, regardless of the type of plastic laminate, the film can be separated into a single layer, and the ink layer can be easily peeled off. Therefore, the molding or molding material obtained by the present invention can be reused as a high-quality recycled plastic raw material.

In the present invention, "molding" refers to processing by placing resin in a mold, such as injection molding. On the other hand, "molding" refers to processing resin without using a mold, such as melting the resin to produce a film or the like.
<About process 1>
The method for producing a molding material or a molding material of the present invention includes a step (step 1) of pulverizing a resin derived from a plastic film to 1 mm or less to change the physical properties of the resin.

In step 1, the step of pulverizing the plastic film into pieces of 1 mm or less is not particularly limited, and can be performed by a known method. The plastic film may be ground dry or wet in water or a detergent.

Among these, it is preferable to use a wet pulverizer that can perform pulverization in water or a washing liquid. When a wet pulverizer is used, the plastic film can be efficiently pulverized, and when the plastic film has an ink layer or is a laminated film, it becomes easy to peel off each layer.

In addition, when using a plastic film or a laminated film having an ink layer, it is sufficient that the plastic film or laminated film is crushed in step 1, and the crushed product has no ink completely removed or is completely peeled into a single layer. It doesn't have to be done. By crushing the laminate in step 1, the ink layer can be easily removed and the laminated film can be peeled off in step 2, which will be described later.

(Crusher)
The pulverizer used in Step 1 is not particularly limited as long as it is a device that can pulverize the plastic film into pieces of 1 mm or less.

One example of a wet pulverizer preferably used in Step 1 is a wet pulverizer that can simultaneously pulverize, disperse, and mix solids in a liquid. Specifically, it is preferable to have a mechanism for crushing solids in a liquid using shearing force and/or frictional force. Among these, those having a mechanism capable of crushing the plastic film while applying a strong crushing force to it by compression, shearing, rolling friction, grinding friction, etc. are preferred. Examples of such a grinder include a grinder, a wet grinding pump, a colloid mill, and the like.

(grinder)
It is preferable that the grinder has a mechanism that rotates a set of upper and lower stone mills in a liquid and uses shearing or friction to crush the solid matter placed between the stone mills, and grinds the solid matter into fine powder while flowing water. It is preferable to use one that can be pulverized up to 100%.

The size of the pulverized product can be adjusted by adjusting the interval between the upper and lower sets of stone mills, but it is usually pulverized to 1 mm or less, 500 μm or less, preferably 300 μm or less, and more preferably 200 μm or less. By pulverizing the pulverized material to a smaller size in this manner, the molecular weight of the resin derived from the plastic film can be reduced, and the MFR can be increased. Moreover, when the plastic film is a laminated film, each layer of the laminated film can be separated into a single layer. Moreover, the storage space for the crushed products can be reduced, and inventory management becomes easier. Furthermore, when producing recycled plastic from the pulverized material, the process can be simplified because it can be fed into a kneader without going through a compressor or the like. On the other hand, the lower limit of the size of the pulverized material is preferably 10 μm or more, preferably 30 μm or more, and more preferably 50 μm or more, in order to facilitate collection. Note that the size of the pulverized material is the size of the longest diameter of the pulverized material.

The rotation speed and water flow speed are not particularly limited.

A specific example of the grinding machine is Super Mascolloider manufactured by Masuko Sangyo Co., Ltd.

(Wet grinding pump)
It is preferable that the wet crushing pump has a mechanism for crushing the solids using a fixed blade and a rotating blade while pumping the solids in the liquid. A more preferable mechanism is a mechanism for crushing the solids using a fixed blade and a rotating blade. It is a mechanism that crushes in three stages by combining four parts.

A wet grinding pump grinds the plastic laminate in three stages. The plastic laminates are roughly cut by the fixed blade cutting blade and the inlet edge of the rotating blade crushing impeller, and then agitated and pumped by the axial flow type crushing impeller, and some plastic laminates are cut by the fixed blade shroud. It hits the blade of the ring and is cut. The laminated film that has passed through the crushing impeller is further finely crushed and agitated with a grid, passed through the grid, and then pressurized by a pressure impeller and sent under pressure to the next process.

The pumping speed is not particularly limited, but in consideration of peeling of the ink layer and peeling and separation efficiency when separating the plastic laminate into each layer, it is preferably 0.03 m ³ /min or more. The upper limit of the pumping speed is not particularly limited, and a standard operating speed of the device, for example, 1.4 m ³ /min, is sufficient to remove the ink and separate the plastic laminate into a single layer.

The grid shape is not particularly limited.

Specific examples of wet grinding pumps include Husqvarna Zenoah's KD series, Nikuni's Suncutter series, Furukawa Industrial Systems' Disintegrator series, Aikawa Iron Works' Ink Crusher series, and Sanwa Hydrotech's Scatter. can be exemplified.

(Colloid mill)
A colloid mill as used in the present invention is a machine used to reduce particle size in dispersions where particles are suspended in a liquid. A colloid mill consists of a combination of a rotor and a stator, and the rotor rotates at high speed relative to the fixed stator. High speed rotation is used to reduce particle size in liquids due to the high levels of shear produced.

The crushing section of the colloid mill consists of a tooth-shaped truncated conical rotor and a stator, and the rotor and stator have a tapered shape that becomes narrower as it approaches the discharge port. The laminated film is crushed by being repeatedly subjected to strong shearing, compression, and impact in a ring-shaped gap that narrows as it approaches the discharge port.

Specific colloid mills are not particularly limited as long as they are dispersion machines that are generally called colloid mills, but include IKA's Colloid Mill MK series, Iwaki's WCM series, Mountech's PUC Colloid Mill series, and Eurotech. An example of this is the Cavitron manufactured by the company.

By pulverizing the plastic film to 1 mm or less in step 1, the physical properties of the resin derived from the plastic film can be changed, for example, from the resin grade required for the film to the resin grade required for injection molding. By pulverizing plastic to a size of 1 mm or less, the polymer chains are broken at various points in the chain, resulting in a decrease in the weight average molecular weight of the resin, a high melt flow rate, and mechanical problems such as elongation in tensile tests. It is thought that the physical properties change.

Further, in step 1, part or all of the laminated film can be separated into single-layer films. In addition to adhesives, laminated films are often provided with a printing ink layer for displaying product names and other decorations. , an offset printer, an inkjet printer, etc., are often used to print with organic solvent-based printing ink, water-based printing ink, or active energy ray-curable ink. For plastic laminates provided with such an ink layer, in order to more efficiently peel off and remove the ink layer, the plastic laminate may be crushed in a cleaning solution containing water containing a cleaning component or a stripping component. good. By crushing the plastic laminate in a cleaning solution containing water containing a cleaning component and a stripping component, it is possible to simultaneously peel off and remove the ink layer provided on the plastic laminate and separate the single layer of the plastic laminate. . For example, the most commonly used inks for plastic laminated films, including those used for food packaging, are gravure inks and flexo inks, but the printing ink layer can also be peeled off during the wet grinding process using a cleaning liquid. Therefore, it is efficient. Further, although the laminated film may include foils or vapor-deposited films of metals such as aluminum, the metal foils and vapor-deposited films can also be peeled off or dissolved in the present invention. In addition, by pulverization, each layer constituting the laminate may be peeled off into a single layer, or a part of the pulverized laminate may be partially peeled off. Further, the ink layer provided on the laminated film does not need to be completely removed from the plastic film in step 1, but may be partially attached or not removed from the ink layer.

In step 1, pulverization may be performed using water as it is, or pulverization may be performed using a cleaning solution containing water containing a cleaning or stripping component such as an inorganic base or a surfactant, or other components. . As the cleaning liquid, water containing one or more of the following components as appropriate can be used. If the cleaning liquid is alkaline, it may damage the pulverizer, so it is preferable to select the cleaning liquid depending on its compatibility with the pulverizer and the releasability of the ink layer.

(Inorganic base)
As the aqueous cleaning liquid that can be used in Step 1, water containing an inorganic base can be used. Specific examples of the inorganic base include sodium hydroxide and potassium hydroxide. These inorganic bases are contained in a concentration of 0.1 to 10% by weight based on the total amount of the aqueous cleaning solution, and a concentration of 0.1 to 5% by weight is more preferable. Further, the pH is preferably 10 or more.

(surfactant)
As the aqueous cleaning liquid that can be used in step 1, water containing a surfactant can be used. The surfactant is not particularly limited, and any known surfactant can be used, such as anionic surfactants, nonionic surfactants, amphoteric surfactants, cationic surfactants, etc. .

Nonionic surfactants generally include, for example, polyoxyalkylene alkyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, Polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, fatty acid alkylolamide, alkyl alkanolamide, acetylene Examples include glycol, oxyethylene adduct of acetylene glycol, polyethylene glycol polypropylene glycol block copolymer, and among these, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, Examples include polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkylolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymer.

In the present invention, 50% by weight or more of water and 0.01% to 5% by weight of a polyoxyalkylene alkyl ether surfactant containing at least one compound represented by general formula (1) are used. Preferably, it is an aqueous cleaning solution containing.

R ¹ -O-[CH ₂ -CH(X ¹ )-O]n ¹ -H (1)
In the general formula (1), R ¹ represents a linear or branched alkyl group, alkenyl group or octylphenol group, n ¹ represents the average number of moles added, and X ¹ represents hydrogen or a short-chain alkyl group.

More preferably, R ¹ in the general formula (1) is a linear or branched alkyl group or alkenyl group having 10 or more carbon atoms. It is preferable that the number of carbon atoms is more than 10 because the ink releasability is better. Specific numbers of carbon atoms include a decyl group with 10 carbon atoms, a lauryl group with 12 carbon atoms, a tridecyl group with 13 carbon atoms, a myristyl group with 14 carbon atoms, a cetyl group with 16 carbon atoms, and a carbon atom. Examples include number 18 oleyl groups and stearyl groups.

Specific products include Dai-ichi Kogyo Seiyaku's Neugen series, DSK NL-Dash series, DKS-NL series, NOF's Nonion series, Kao's Emulgen series, and Lion's Reox. Among the nonionic surfactants represented by the general formula (1) among the series, Leocol series, Lionol series, etc., if the number of carbon atoms represented by R ¹ is 10 or more, it is applicable, but it is limited to this. It's not a thing.

The HLB value of the polyoxyalkylene alkyl ether surfactant represented by the general formula (1) is not particularly limited. The HLB value here is a value representing the degree of affinity of a surfactant for water and oil (organic compounds insoluble in water), and is calculated using the Griffin method (HLB value = 20 x formula weight of hydrophilic part). (total sum of molecular weight/molecular weight).

Among the nonionic surfactants represented by the general formula (1), specific surfactants in which R ¹ has 10 or more carbon atoms and an HLB value of less than 12.5 are manufactured by Daiichi Kogyo Co., Ltd. For pharmaceutical companies, Neugen XL-41, Neugen LF-40X, Neugen TDS-30, Neugen TDS-50, Neugen TDS-70, Neugen TDX-50, Neugen SD-30, Neugen SD-60, DKS NL-15, DKS NL-30, DKS NL-40, DKS NL-50, DKS NL-60, DKS NL-70, Neugen ET-83, Neugen ET-102, DSK Dash400, DSK Dash403, DSK Dash404, DSK Dash408, Neugen LP-55 Neugen LP-70, Neugen ET-65, Neugen ET-95, Neugen ET-115, Neugen ET-69, Neugen ET-89, Neugen ET-109, Neugen ET-129, Neugen ET-149, manufactured by NOF Corporation. , Nonion K-204, Persoft NK-60, Nonion P-208, Nonion P-210, Nonion E-202, Nonion E-202S, Nonion E-205, Nonion E-205S, Nonion S-202, Nonion S- 207, Nonion EH-204, Nonion ID-203, Nonion HT-505, Nonion HT-507, Nonion HT-510, Nonion HT-512, manufactured by Kao Corporation, Emulgen 102KG, Emulgen 103, Emulgen 104P, Emulgen 105, Emulgen 106, Emulgen 108, Emulgen 210P, Emulgen 404, Emulgen 408, Emulgen 409PV, Emulgen 705, Emulgen 707, manufactured by Lion Corporation, Reox CL-30, Reox CL-40, Reox CL-50, Reox CL-60, Reokol NL Examples include, but are not limited to, Rheokol-30C, Rheokol TD-50, Rheokol TD-70, Rheokol SC-50, and Rheokol SC-70.

In addition, among the nonionic surfactants represented by the general formula (1), R1 represents a linear or branched alkyl group or alkenyl group having 10 or more carbon atoms, and the HLB value is 12.5 or more. The specific surfactants are Noogen XL-61, Noogen XL-6190, Noigen XL-70, Noigen XL-80, Noigen XL-100, Noigen XL-140, Noigen XL-160 from Daiichi Kogyo Seiyaku Co., Ltd. , XL-400D, Neugen XL-1000, Neugen LF-60X, Neugen LF-80X, Neugen LF-100X, Neugen TDS-80, Neugen TDS-100, Neugen TDS-120, Neugen TDS-200D, Neugen TDS-500F, Neugen TDX-80, Neugen TDX-80D, Neugen TDX-100D, Neugen TDX-120D, Neugen SD-70, Neugen SD-80, Neugen SD-110, Neugen SD-150, DKS NL-80, DKS NL-90, DKS NL-100, DKS NL-110, DKS NL-180, DKS NL-250, DKS NL-450F, DKS NL-600F, Neugen ET-160, Neugen ET-170, Neugen ET-190, DSK Dash410, Neugen LP -80, Neugen LP-100, Neugen LP-180, Neugen ET-135, Neugen ET-165, Neugen ET-159, Neugen ET-189, NOF Corporation's Nonion K-220, Nonion K-230, Nonion K-2100W, Persoft NH-90C, Persoft NK-100, Persoft NK-100C, Nonion P-210, Nonion P-213, Nonion E-212, Nonion E-215, Nonion E-230, Nonion S- 215, Nonion S-220, Nonion B-250, Nonion ID-206, Nonion ID-209, Dispanol TOC, Nonion HT-515, Nonion HT-518, manufactured by Kao Corporation, Emulgen 109P, Emulgen 120, Emulgen 123P, Emulgen 130K, Emulgen 147, Emulgen 150, Emulgen 220, Emulgen 320P, Emulgen 350, Emulgen 420, Emulgen 430, Emulgen 709, Emulgen 1108, Emulgen 1118S-70, Emulgen 1135S-70, Emulgen 1150S-60, Emulgen 4085, Emulgen 20 20G -HA, Emulgen 2025G, manufactured by Lion Corporation, Reoxk CL-90, Reoxk CL-230, Reokol TD-90, Reokol TD-90D, Reokol TDA-90-25, Reokol TDN-90-80, Reokol TD-120, Examples include Reocol TD-200, Reocol TDA-400-75, Reocol SC-80, Reocol SC-90, Reocol SC-120, Reocol SC-150, Reocol SC-200, Reocol SC-300, and Reocol SC-400. However, it is not limited to this.

In general formula (1), when R ¹ is an octylphenol group, octylphenol ethoxylate is preferred.

Specific products include, but are not limited to, the Dow Chemical Company's TRITON (registered trademark) series, Rhodia's Igepal CA series, Shell Chemicals' Nonidet P series, and Nikko Chemicals' Nikkol OP series. isn't it.

Specifically, the amphoteric surfactant is preferably a betaine type surfactant, for example, an amphoteric interface of an alkylcarboxybetaine skeleton or an alkylamide carboxybetaine skeleton containing at least one compound represented by the general formula (2a). More preferably, it contains an activator.

R1-R2-N ⁺ (CH ₃ ) ₂ CH ₂ COO ^- (2a)
(In general formula (2a), R1 represents hydrogen or C(=O)R3-NH- (R3 represents a linear or branched alkyl group or alkenyl group), and R2 represents an alkylene group or an alkenylene group. .)
In general formula (2a), R1 preferably represents a hydrogen atom.
The compound represented by the general formula (2a) is preferably an amphoteric surfactant having an alkylcarboxybetaine skeleton represented by the general formula (2a-1).

C _n H _2n+1 N ⁺ (CH ₃ ) ₂ CH ₂ COO ^- (2a-1)
(In general formula (2a-1), n indicates the average number of added moles.)
In general formula (2a-1), n is preferably 8 or more, preferably 10 or more, and preferably 11 or more.

Specific products corresponding to general formula (2a) include Nissan Anon BDF (registered trademark)-R, Nissan Anon BDF (registered trademark) -SF, Nissan Anon BDC-SF, and Nissan Anon BDL manufactured by NOF Corporation. -SF, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Amogen CB-H, Amogen HB-C, manufactured by Shin Nippon Rika Co., Ltd., Rikavion B-200, Rikavion B-300, manufactured by Toho Chemical Industry Co., Ltd., Obazoline CAB-30, Examples include ovazoline ISAB. Further, specific products corresponding to general formula (1a-1) include Amogen S, Amogen SH, and Amogen K manufactured by Daiichi Kogyo Seiyaku Co., Ltd.; and Amhitol 20BS, Amhitol 24B, and Amhitol manufactured by Kao Corporation. 86B, manufactured by NOF Corporation: Nissan Anon BF, Nissan Anon BL, Nissan Anon BL-SF; manufactured by New Japan Chemical Co., Ltd., Rikavion A-100, Rikavion A-200, Rikavion A-700; manufactured by Toho Chemical Co., Ltd., Examples include, but are not limited to, ovazoline LB, ovazoline LB-SF, and the like.

In addition, the betaine type amphoteric surfactant may have an imidazolinium betaine skeleton, and specific products manufactured by NOF include Nissan Anon GLM-R and Nissan Anon GLM-R-LV. and Anhitor 20Y-B manufactured by Kao Corporation, but are not limited to these.

Further, the amphoteric surfactant may be a surfactant represented by the following general formula (2b).

R4-(NHC ₂ H ₄ ) _nb -N(R5) ₂ (2b)
(In the general formula (2b), R4 represents a linear or branched alkyl group or alkenyl group, nb represents an integer of 0 to 5, and R5 represents hydrogen, -CH ₂ COONa or -CH ₂ COOH. , two R5s may be the same or different, and at least one R5 represents -CH ₂ COONa.)
In general formula (2b), R4 preferably represents a linear alkyl group, and the number of carbon atoms in R4 is preferably 8 or more, preferably 10 or more, and preferably 12 or more.

Specific products corresponding to general formula (2b) include, but are not limited to, Nissan Anon LG-R and Nissan Anon LA manufactured by NOF Corporation.

Further, the amphoteric surfactant may be an amine oxide type surfactant represented by the following general formula (2c).

R6-N ⁺ (CH ₃ ) ₂ O ^- (2c)
(In general formula (2c), R6 represents a linear or branched alkyl group or alkenyl group.)
In general formula (2c), R6 is in general formula (2b), R4 preferably represents a linear alkyl group, and the number of carbon atoms in R4 is preferably 8 or more, preferably 10 or more. , preferably 12 or more.

Specific products corresponding to general formula (2c) include, but are not limited to, Amogen AOL manufactured by Daiichi Kogyo Seiyaku Co., Ltd. and Amhitol 20N manufactured by Kao Corporation.

Specifically, the cationic surfactant is preferably a cationic surfactant with a quaternary ammonium skeleton, such as a cationic surfactant with a quaternary ammonium skeleton containing at least one compound represented by the general formula (3a). More preferably, it contains an activator.

R1-N ⁺ (R2R3)-R4 (3a)
(In general formula (3a), R1 represents a straight-chain or branched alkyl group, or a straight-chain or branched alkenyl group, and -CH ₂ - in the alkyl group or alkenyl group is -C(=O) -, -NH- or -C(=O)-NH-, R2 and R3 represent a hydrogen atom, a straight-chain or branched alkyl group, or a straight-chain or branched alkenyl group, and R4 represents a hydrogen atom, a straight-chain or branched alkyl group, a straight-chain or branched alkenyl group, or a phenyl group, and the terminal -CH ₃ in the alkyl group or alkenyl group is substituted with a carboxy group or a phenyl group. may be done.)
In general formula (3a), R1 is preferably a long-chain alkyl group or alkenyl group, specifically an alkyl group or alkenyl group having 8 to 30 carbon atoms, in order to further improve the releasability of the ink. It is preferably a group, preferably an alkyl group having 10 to 25 carbon atoms, and preferably an alkyl group or alkenyl group having 12 to 22 carbon atoms. The alkyl group or alkenyl group may be linear or branched, but it is preferably a linear alkyl group, and more preferably a linear alkyl group.

In R1, at least one -CH ₂ - in the alkyl group or alkenyl group may be substituted with -C(=O)-, -NH- or -C(=O)-NH-. Among these, it is preferable that at least one -CH ₂ - in the alkyl group or alkenyl group is substituted with -C(=O)-NH- or -NH-C(=O); It is preferable that one -CH ₂ - is substituted with -C(=O)-NH- or -NH-C(=O), and it is more preferable that R1 has an amidopropyl skeleton.

R2 and R3 preferably represent a straight-chain or branched alkyl group or a straight-chain or branched alkenyl group, and preferably represent a straight-chain or branched alkyl group. Among these, a linear alkyl group having 1 to 3 carbon atoms is preferred, and a methyl group is more preferred.

R4 preferably represents a straight-chain or branched alkyl group, a straight-chain or branched alkenyl group, or a phenyl group, and more preferably a straight-chain or branched alkyl group. Furthermore, the terminal --CH ₃ in the alkyl group or alkenyl group is preferably substituted with a carboxy group or a phenyl group.

R4 preferably has 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and more preferably 1 or 2 carbon atoms.

When R4 represents a methyl group, it is preferable that R2 and R3 also represent a methyl group, and general formula (3a) represents an alkyltrimethylammonium skeleton.

Furthermore, when R4 represents an ethyl group, the terminal --CH ₃ in the ethyl group is preferably substituted with a carboxy group or a phenyl group. That is, it is preferable that R4 represents -CH ₂ -(C(=O)OH or a benzyl group.
The compound represented by the general formula (3a) is preferably a cationic surfactant having a quaternary ammonium skeleton represented by the general formula (3a-1).

C _n H _2n+1 N ⁺ (CH ₃ ) ₂ R4 (3a-1)
(In the general formula (3a-1), n represents the average number of added moles, and R4 has the same meaning as R4 in the general formula (3a) according to claim 3.)
In the general formula (3a-1a), the number of carbon atoms represented by n is preferably 8 or more. The greater the number of carbon atoms is, the better the ink removability is and is preferred. The specific number of carbon atoms is 8 or more carbon atoms. octyl group with 9 carbon atoms, nonyl group with 9 carbon atoms, decyl group with 10 carbon atoms, undecyl group with 11 carbon atoms, lauryl group with 12 carbon atoms, tridecyl group with 13 carbon atoms, myristyl group with 14 carbon atoms Examples include a pentadecyl group having 15 carbon atoms, a cetyl group having 16 carbon atoms, an oleyl group having 18 carbon atoms, and a stearyl group.

Preferred groups for R4 are the same as those in general formula (3a).
These cationic surfactants having a quaternary ammonium skeleton are preferably of the quaternary ammonium skeleton salt type in which a salt is formed with a halogen, preferably a salt with a Cl ⁻ , and more preferably a salt with a Cl ⁻ . It is preferable to form a salt, and more preferably to form a salt with ^I- . A quaternary ammonium skeleton salt formed into a salt with a halogen is considered to improve the releasability of the ink because it promotes hydrolysis of the ink film due to the nucleophilic action of the halogen.

Among these, compounds of the alkyltrimethylammonium chloride type, dialkyldimethylammonium chloride type, and alkylbenzalkonium chloride type are preferred.

Specific products corresponding to general formula (3a) or (3a-1) include Nissan Cation MA, Nissan Cation SA, Nissan Cation BB, Nissan Cation FB, Nissan Cation PB-300, and Nissan Cation PB-300 manufactured by NOF Corporation. Cation ABT2-500, Nissan Cation AB, Nissan Cation AB-600, Nissan Cation VB-M Flake, Nissan Cation VB-F, Nissan Cation 2-DB-500E, Nissan Cation 2-DB-800E, Nissan Cation 2ABT, Nissan Cation 2-OLR, Nissan Cation F ₂ -50R, and Nissan Cation M ₂ -100R, and those manufactured by Daiichi Kogyo Co., Ltd. include Cation Gen TML, Cation Gen TMP, Cation Gen TMS, Cation Gen DDM-PG, Cation Gen BC-50, and Cation Gen TBB. Kao Corporation's products include Cortamine 24P, Cortamine 86P Conc, Cortamine 60W, Cortamine 86W, Sanizol C, and Sanizol B-50, and Lion's products include Lipoguard C-50, Lipoguard T-28, and Lipoguard T-30. , Lipo Guard T-50, Lipo Guard T-800, Lipo Guard 16-29, Lipo Guard 16-50E, Lipo Guard 18-63, Lipo Guard 22-80, Lipo Guard CB-50, Lipo Guard 210-80E, Lipo Guard 2C-75, Lipo Guard 2 HP-75 , Lipoguard 2HP flakes, Lipoguard 2HT-75, Lipoguard 2HT flakes, Lipoguard 20-75l, Lipoguard 41-50, TMAC-50, TPAH-40, TBAB-50A, TBAB-100A, TBAH-40, Lipoguard PH-100, BTMAC -50, BTMAC-100A, BTEAC-50, BTEAC-100A, BTBAC-50A, etc., but are not limited to these.

The cationic surfactant preferably contains at least one compound represented by a primary to secondary alkanolamine skeleton, and preferably contains at least one compound represented by a monoalkanolamine skeleton. It is preferable.
The primary monoalkanolamine is preferably a lower alkanol having 1 to 4 carbon atoms, and specific examples include monoethanolamine and 2-aminoisobutanol. Examples include N-methylethanolamine, 2-ethylaminoethanol, and isopropanolamine, but substances other than those listed can also be used as appropriate. Further, these monoalkanolamine compounds can be used alone or in an appropriate combination of two or more, and can also be used by mixing with water.
These cationic surfactants having a monoalkanolamine skeleton are preferably of the monoalkanolamine salt type in which a salt is formed with a halogen, and preferably a salt is formed with ^Cl.sup.- .

These surfactants can be used alone or in combination of two or more. The amount added is preferably 5% by weight or less, and preferably 2% by weight or less, based on the total amount of the aqueous cleaning liquid. The lower limit of the surfactant is not particularly limited and may be 0% by mass, but if a surfactant is contained, it is preferably 0.1% by mass or more.

(Alkylene glycol alkyl ether solvent)
As the aqueous cleaning liquid that can be used in Step 1, water containing an alkylene glycol alkyl ether solvent can be used. Preferably, it is an aqueous cleaning liquid containing 20% by weight or more of a solvent having an alkylene glycol alkyl ether skeleton represented by the general formula (4).

R ¹ -O-[CH ₂ -CH(X)-O]n ¹ -R ² (4)
(In general formula (4), R ¹ is an alkyl group having 1 or more carbon atoms, R ² is an alkyl group having 1 or more carbon atoms or hydrogen, n ¹ is an integer of 1 to 3, and X is hydrogen or (Indicates a methyl group.)
Among the alkylene glycol alkyl ethers represented by the general formula (4), water-soluble alkylene glycol alkyl ethers are more preferred.

Examples of the water-soluble alkylene glycol alkyl ether represented by the general formula (4) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether. , ethylene glycol dipropyl ether, ethylene glycol methyl ethyl ether, ethylene glycol methyl propyl ether, ethylene glycol ethyl propyl ether, ethylene glycol monobutyl ether, ethylene glycol-tert-butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether , diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl propyl ether, diethylene glycol ethyl propyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene Examples include glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, and propylene glycol diethyl ether.
These alkylene glycol alkyl ethers can be used alone or in an appropriate combination of two or more, and can also be used by mixing with water. There is no particular problem with the alkylene glycol alkyl ether content as long as it is 20% by weight or more, but when water is the medium, it is preferably 30% by weight or more, most preferably 40% by weight or more. On the other hand, the upper limit may be 100% by weight, but from the viewpoint of environmental impact and safety, it is preferable to use water as the medium.

Among the water-soluble alkylene glycol alkyl ethers represented by general formula (4), more preferred are alkylene glycol monoalkyl ethers represented by general formula (5).

R ² -O-[CH ₂ -CH(X)-O]n ² -H (5)
(In the general formula (5), R ² represents an alkyl group having 1 or more carbon atoms, n ² represents an integer of 1 to 3, and X represents hydrogen or a methyl group.)
Examples of the water-soluble alkylene glycol alkyl ether represented by the general formula (5) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether, and ethylene glycol-tert. -Butyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol Examples include monobutyl ether, dipropylene glycol monomethyl ether, and tripropylene glycol monomethyl ether.

Furthermore, in an aqueous cleaning solution containing a water-soluble alkylene glycol alkyl ether represented by the general formula (5), releasability can be maintained even in a composition in which the water content is much more than 50% by weight. , R ² is preferably an alkyl group having 3 or more carbon atoms, n ² is 1 to 3, and X ² is hydrogen or a methyl group.

Specifically, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol-tert-butyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monobutyl ether, Examples include propylene glycol monomethyl ether. These alkylene glycol alkyl ethers can be used alone or in an appropriate combination of two or more, and can also be used by mixing with water.

Furthermore, among these, diethylene glycol monobutyl ether, ethylene glycol mono-tert-butyl ether, and propylene glycol monopropyl ether are particularly preferred from the viewpoint of environmental characteristics, flammability, and antifoaming properties.

(antifoaming agent)
The water used in step 1 may contain an antifoaming agent. In step 1, a large amount of foam may be generated during the stirring and crushing steps, and if the foam remains, the foam may overflow during the plastic film recovery step. Furthermore, in the plastic film crushing process, if a large amount of bubbles are involved in the cleaning liquid, the plastic substrate may not be crushed to a desired size.

Compounds commonly used as antifoaming agents include water-soluble organic solvents and nonionic surfactants with low HLB values, but silicone compounds are particularly preferred in terms of their high antifoaming ability. . Among these, emulsion type and self-emulsifying type silicone compounds are preferred.

As specific antifoaming agents, self-emulsifying types include X-50-1176, KS-530, and KS-537 manufactured by Shin-Etsu Chemical Co., Ltd., and emulsion type agents include KM-7750D and KM manufactured by Shin-Etsu Chemical Co., Ltd. Examples include, but are not limited to, -7752, KM-98, FS Antifoam 025, FS Antifoam 80, FS Antifoam 92, FS Antifoam 93, DKQ1-1183, and DKQ1-1247 manufactured by Nagase Chemspec.

(liquid temperature)
The liquid temperature of the water or cleaning liquid used in Step 1 is not particularly limited as long as it can maintain a liquid state, and it is usually preferable to carry out the liquid temperature at a temperature of 0°C to 90°C. When using an aqueous cleaning liquid prepared by adding a surfactant or the like to water, it is preferable to adjust the liquid temperature depending on the type of surfactant. The optimum temperature for achieving excellent cleaning effects varies depending on the type of surfactant, but is preferably 40°C or higher, preferably 65°C or higher, and preferably 85°C or higher.

<About process 2>
The molding or molding material of the present invention may have a step 2 of heating and stirring the blasted plastic film pulverized in step 1 in a release agent. When the plastic film is a plastic film having an ink layer, by performing Step 2 after crushing the laminated film in Step 1, it is possible to peel off the ink layer that remained attached without being peeled off from the crushed material. can.

In addition, when the plastic film is a laminated film having at least a plastic film layer and a layer selected from another plastic layer different from the plastic layer, a vapor deposited film layer, and a metal foil layer, the laminated film is crushed in step 1. By performing step 2 later, the laminated film can be more completely peeled into a single layer. For example, even if the films are not completely separated into a single layer by the crushing process in Step 1, the broken surface is exposed in Step 1, so performing Step 2 after Step 1 will prevent the cleaning liquid from penetrating. This facilitates formation of a single layer.

Therefore, by performing step 2, higher quality molding or molding material can be obtained. If the plastic film is a virgin plastic film, step 2 is not necessary.

(paint remover)
The release agent used in step 2 can be one that promotes separation of the laminate into single layers and facilitates the easy release of the ink layer from the plastic film having the ink layer. As such a stripping agent, it is preferable to use one containing (a) a solvent and (b) an inorganic base.

(a) The solvent may be any solvent as long as it can dissolve the (b) inorganic base, and may be a water-soluble solvent or a non-aqueous solvent.

The water-soluble solvent preferably contains one or more water-soluble alcohols or water-soluble solvents with a flash point of 21° C. or higher. By using a water-soluble solvent as a stripping agent, the hydroxide ions generated from the inorganic base contained in the stripping agent are difficult to be hydrated, so the nucleophilicity of the hydroxide ions increases, and it also It is effective in removing the ink film because it can advance the reaction for removing the ink layer.
The water-soluble solvent having a flash point of 21° C. or higher is preferably a water-soluble solvent among organic solvents that fall under the second petroleum class and the third petroleum class specified in the Fire Service Act. Furthermore, examples of water-soluble alcohols include alcohols specified in the Fire Service Act. Specific examples of these include 3-methoxy-3-methyl-1-butanol, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, and ethanol, which may be used alone or in combination.

The non-aqueous solvent is preferably a compound having an ethylene glycol skeleton and an aromatic skeleton, and phenoxyethanol is preferably used.

It is preferable that the entire stripping agent contains the above-mentioned solvent in an amount of 20% by mass or more. When the content of the water-soluble solvent is less than 20% by mass, it becomes difficult to obtain a sufficient effect in peeling off the ink layer. From the viewpoint of the releasability of the ink layer, it is preferable to contain a large amount of water-soluble solvent in the release agent, specifically, the water-soluble solvent is preferably 30% by mass or more, and preferably 40% by mass or more, It is preferably 50% by mass or more, preferably 60% by mass or more, preferably 70% by mass or more, preferably 80% by mass or more, preferably 90% by mass or more, It is preferably 95% by mass or more.

(b) Specific examples of the inorganic base include sodium hydroxide and potassium hydroxide, and it is preferable to use potassium hydroxide. These inorganic bases are preferably contained in a concentration of 0.1 to 10% by weight, more preferably 0.1 to 5% by weight, based on the total amount of the ink remover. Further, the pH is preferably 10 or more, preferably 11 or more, and more preferably 12 or more.

When the stripping agent in step 2 is a water-soluble solvent, it may contain (c) water. By containing water in the release agent in step 2, the work stability and environmental stability in step 2 can be improved. The content of water is preferably 80% by mass or less based on the release agent. When the water content exceeds 80% by mass, it becomes difficult to obtain sufficient effects in separating the laminate into single layers and peeling off the ink layer.

The ratio of water-soluble solvent to water can be adjusted as appropriate from the viewpoint of peeling effect and safety of the plastic film and ink layer, but the mass ratio is within the range of water-soluble solvent: water = 20:80 to 100:0. It is preferable to use it in The lower limit of the proportion of water-soluble solvent in the total amount of water-soluble solvent and water is preferably 20% by mass, preferably 30% by mass, preferably 50% by mass, and 70% by mass. is preferably 80% by mass, preferably 90% by mass, and preferably 100% by mass.

The release agent in step 2 may contain (d) a surfactant. The surfactant is not particularly limited, and any known surfactant can be used, such as anionic surfactants, nonionic surfactants, amphoteric surfactants, cationic surfactants, etc. . As specific types of these surfactants, those similar to those described as surfactants that can be contained in water in Step 1 can be used.
In the stripping agent in Step 2, the surfactant can be used alone or in combination of two or more types. The amount added is preferably 5% by weight or less, and preferably 2% by weight or less, based on the total amount of the release agent. The lower limit of the surfactant is not particularly limited and may be 0% by mass, but if a surfactant is contained, it is preferably 0.01% by mass or more.

(temperature)
In step 2, the temperature at which the cleaning liquid is stirred, that is, the liquid temperature, is not particularly limited. Since the cleaning effect as a stripping agent is higher when the liquid temperature is higher, the temperature is preferably 40°C or higher, preferably 50°C or higher, and preferably 60°C or higher. The upper limit of the liquid temperature is not particularly limited as long as the liquid state can be maintained, but it is usually preferably 90°C or lower.

(stirring)
In step 2, the equipment and method for stirring the pulverized laminate in the cleaning liquid are not particularly limited, and any known method can be used. Specifically, there are devices equipped with a motor with stirring blades that can stir the cleaning liquid within a container, devices equipped with a device that generates ultrasonic waves, devices that can shake the entire container, and wet crushers. It will be done. As the wet pulverizer, one similar to the pulverizer described in Step 1 can be used. Since strong stirring can be performed by using a wet grinder in step 2, if part of the laminate cannot be completely peeled into a single layer in step 1, it can be peeled into a single layer in step 2. Can be done.

(Collection equipment)
The pulverized plastic material separated into single layers in step 2 can be collected every single layer. Equipment and methods for recovering crushed plastics are not particularly limited, but for example, filters, centrifuges, automatic scraping bar screens, inclined wire screens, rotating drum screens, etc. can be used. can.

(Plastic film)
The plastic film used for molding or molding material of the present invention may be a single layer film or a multilayer laminated film. Further, it may be a recycled film having a printed layer or the like that has been used for soft packaging materials, or a virgin plastic film.

Examples of plastic films include polyolefin films such as low-density polyethylene, high-density polyethylene, linear low-density polyethylene, OPP (biaxially oriented polypropylene), and CPP (unoriented polypropylene); polyethylene terephthalate (PET), polybutylene terephthalate polyester films such as nylon 6, nylon 6,6, and meta-xylene adipamide (N-MXD6); biodegradable films such as polylactic acid; polyacrylonitrile films; poly(meth)acrylic films Films containing these pigments include films; polystyrene films; polycarbonate films; saponified ethylene-vinyl acetate copolymer (EVOH) films; polyvinyl alcohol films; and K coats such as polyvinylidene chloride. Transparent vapor-deposited films in which alumina, silica, or the like is vapor-deposited on these films may also be used. Among these, a film containing at least a polyolefin resin is preferable.

In the present invention, the molding or molding material obtained by pulverizing a plastic film has a weight average molecular weight (Mw2) of the molding or molding material after pulverization that is smaller than the weight average molecular weight (Mw1) of the resin derived from the plastic film before pulverization. . Specifically, when using an olefin resin as a plastic film, the film grade of the olefin resin has a weight average molecular weight of about 450,000, but the weight average molecular weight (Mw2) of the molding or molding material after pulverization is about 400,000. It is preferably below, preferably below 380,000, and preferably below 350,000.

In addition, in the present invention, the molding or molding material obtained by pulverizing the plastic film has a melt flow rate (MFR2) of the molding or molding material after pulverization that is higher than the melt flow rate (MFR1) of the resin derived from the plastic film before pulverization. growing. Specifically, when using an olefin resin as a plastic film, the film grade of the olefin resin has an MFR of about 5 to 10, but the melt flow rate (MFR2) of the molding or molding material after pulverization is higher than before pulverization. For example, it is preferably 5 or more, preferably 10 or more, and preferably 15 or more.

The plastic film may have an ink layer.

(Plastic laminate)
The plastic film used for molding or molding material of the present invention may be a laminated film having at least a plastic film layer and a layer selected from a plastic film layer, a vapor deposited film layer, and a metal foil layer. A laminated film is a laminated film in which a plurality of layers such as an ink layer, an adhesive layer, and other plastic films are laminated on a plastic film. Examples of such laminated films include, without limitation, laminated films laminated with reactive adhesives used for food packaging and household goods, but of course non-reactive adhesives such as thermoplastic resins can be used. A laminated film laminated with an adhesive or a laminated film obtained by heat-sealing by an extrusion lamination method can also be separated and recovered into individual monolayer films by the separation and recovery method of the present invention. Further, it may be a sheet-shaped or container-shaped laminate.

That is, a feature of the present invention is that plastic laminated films having various types of resin layers that have been discarded through recycling can be processed together without having to be re-separated.

In addition, shrink labels, which are laminated films formed in a cylindrical shape, are used on containers such as plastic bottles to display product names and add decoration, and the shrink labels are consumed when recycled. In many cases, the PET bottle body and the shrink label are peeled off by a person and disposed of separately, but in the separation and collection method of the present invention, even if the PET bottle body and the shrink label are integrated, the shrink label is removed from the PET bottle body. The labels can be separated and the shrink labels can be separated into each single layer film.

A laminated film laminated with a reactive adhesive often has an adhesive layer made of the reactive adhesive laminated between at least two resin film layers, metal foil, or vapor deposited film layers. Specifically, in the laminated film, the resin film layer is expressed as (F), the metal foil layer or vapor deposited film layer is expressed as (M), and the adhesive layer such as the reactive adhesive is expressed as (M). When expressed as (AD), the following configuration can be considered as a specific embodiment of the laminated film, but of course it is not limited to this.
(F)/(AD)/(F),
(F)/(AD)/(F)/(AD)/(F),
(F)/(AD)/(M)/(AD)/(F),
(F)/(AD)/(M),
(F)/(AD)/(M)/(F),
(F)/(AD)/(F)/(AD)/(M)/(AD)/(F),
(F)/(AD)/(M)/(AD)/(F)/(AD)/(F),
(M)/(AD)/(F)/(AD)/(M),
(AD)/(F)/(AD)/(M),
(AD)/(F)/(AD)/(F)/(AD), etc.

The laminated film may further include a paper layer, an oxygen absorption layer, an anchor coat layer, an ink layer, a release primer layer provided to facilitate ink removal, and the like.

The ink layer is a printing ink printed with an organic solvent-based printing ink, a water-based printing ink, or an active energy ray-curable ink using, for example, a gravure printing machine, a flexo printing machine, an offset printing machine, an inkjet printing machine, or the like. The ink layer may be printed in multiple colors using a plurality of ink types. In the present invention, by going through Steps 1 and 2, the ink layer can be peeled off regardless of the type of ink.

The location where the ink layer is provided is not particularly limited. For example, the ink layer may be provided as the outermost layer of the laminated film, or may be provided between the resin film layer (F) and the adhesive layer (AD). When there is an ink layer between the resin film layer (F) and the adhesive layer (AD) (back printing), the ink layer and the adhesive layer are bonded more firmly, making it more difficult to peel off the ink layer. However, by the method of the present invention, the ink layer can be effectively peeled off even in a back printing configuration.

For example, when the structure of the laminated film is (F1)/INK/(AD)/(M)/(F2) or (F1)/INK/(AD)/(F2), the ink layer exists between the layers constituting the laminate, and the ink layer and adhesive layer are more strongly bonded, so it is difficult to separate them into single layers and remove the ink layer. However, if part of the film of F2 is peeled off in step 1, or if F2 is made into a pulverized product in a state where it can be easily peeled off, the remaining layer structure can be easily peeled off and the ink layer can be removed in step 2. It is.

The resin film layer (F) functions as a base film layer (F1), a sealant layer (F2) which becomes a heat-sealing part when forming a packaging material, etc. when classified according to required roles. The base film layer (F1) is similar to the plastic film described above, and preferably contains at least an olefin resin. Further, the surface of the film may be subjected to various surface treatments such as flame treatment, corona discharge treatment, or chemical treatment with a primer or the like.

The flexible polymer film that becomes the sealant layer (F2) includes polyethylene film, polypropylene film, polyolefin film such as ethylene-vinyl acetate copolymer, ionomer resin, EAA resin, EMAA resin, EMA resin, EMMA resin, A film of decomposed resin is preferred. Common names include CPP (unoriented polypropylene) film, VMCPP (aluminized unoriented polypropylene film), LLDPE (linear low density polyethylene), LDPE (low density polyethylene), HDPE (high density polyethylene), and VMLDPE (aluminum vapor deposited). Examples include low-density polyethylene film), films containing these pigments, and the like. The surface of the film may be subjected to various surface treatments such as flame treatment, corona discharge treatment, or chemical treatment with a primer or the like.

Examples of the metal foil layer (M) include foils of metals with excellent malleability, such as gold, silver, copper, zinc, iron, lead, tin, alloys thereof, steel, stainless steel, and aluminum.

Examples of the paper layer include natural paper and synthetic paper. The first and second sealant layers may be formed from similar materials to the sealant layers described above.

Other layers may contain known additives and stabilizers, such as antistatic agents, non-reactive adhesive layers, adhesive coating agents, plasticizers, lubricants, antioxidants, and the like.

The laminated film of the present invention can be used for molding or a material for molding can be obtained by separating and recovering the pulverized resin derived from the plastic film in the laminated film through Steps 1 and 2.

Hereinafter, an example of a specific aspect of the method for producing a molding material or a molding material will be described.

(1) Plastic film crushing process (process 1)
First, a plastic film or a laminated film containing a plastic film is sequentially introduced into a pulverizer filled with water or a cleaning liquid to obtain a pulverized plastic product. At this time, the plastic film or the laminated film may be cut into plastic pieces having a square size of, for example, 5 mm to 10 mm and then fed into a crusher. By passing through the cutting step, the pulverization in the pulverizer in the next step can be performed more efficiently. For cutting, a known crusher can be used, such as an impact crusher such as a hammer crusher or a rotary crusher, or a dry crusher such as a shredder or cutter. Although the size and shape of the cut plastic laminate pieces are not particularly limited, the maximum length of the plastic pieces is, for example, preferably 100 mm or less, preferably 70 mm or less, and preferably 50 mm or less. The lower limit is not particularly limited, but is preferably 1 mm or more, preferably 3 mm or more, and preferably 5 mm or more.

For example, a laminated film obtained by cutting a film roll into a square size of about 5 to 10 mm is drawn into a crushing section by the suction of a crusher, and is pulverized into pieces of 1 mm or less, preferably 500 μm or less, in water or in a detergent. The lower limit of the size of the pulverized product is not particularly limited, but is, for example, 10 μm or more, preferably 50 μm or more.

At this time, at least a portion of each layer constituting the laminated film is likely to be separated into a single layer due to the high shear that the introduced film receives when being crushed. When the laminated film is provided with an ink layer, the ink layer is also easily peeled off and removed from the film due to the high shear caused by pulverization, and it is preferable that at least a portion of the ink layer is peeled off.

Even if the object to be wet-pulverized is not a laminated film roll but an individual film bag collected from the market, it can be directly input into the wet-pulverizer in the same state as it was collected.

The number of times of the pulverization step in step 1 may be one time or divided into several times. For example, if multiple wet pulverization steps are performed in Step 1, each cleaning liquid may be changed. Further, during this step or after step 1, known steps such as washing, draining, dehydration, drying, etc. may be added as appropriate.

(2) Step of stirring the crushed plastic material in the cleaning liquid (Step 2)
If the plastic film has an ink layer, step 2 may be performed. In step 2, the pulverized plastic material pulverized in step 1 is stirred in a release agent using a known stirring device such as a homodisper or a wet grinder similar to step 1, thereby forming a laminated film into a single layer. At the same time as separating, if an ink layer is present, the ink layer is peeled off from the plastic film.

The liquid temperature and stirring time when stirring in the stripping agent are not particularly limited, and can be adjusted as appropriate from various conditions such as the material of the cleaning liquid used and the structure of the laminate.

The number of times the stirring step in the release agent in Step 2 may be performed once or divided into several times. For example, if step 2 is performed multiple times, each release agent may be changed. Further, during this step or after step 2, known steps such as washing, draining, dehydration, drying, etc. may be added as appropriate.

(3) Recovery process of the separated pulverized mixture of each single layer (process 3)
When the laminate is separated into single layers as a crushed plastic product in Step 1, or Steps 1 and 2, the water or cleaning liquid in Step 1 and the release agent in Step 2 contain the monolayer film of each separated layer, Residues of adhesives, printing ink, metal foil, etc. are floating or dissolved. After these are removed from the cleaning solution, they are separated and collected.

As an example of a specific method, for example, in flotation sorting, plastics with a light specific gravity such as polyolefins such as polypropylene and polyethylene (floats), condensation synthetic films such as polyester and nylon, which have a higher specific gravity than polyolefins, or metals are used. Heavy items such as foil are sorted and removed, then the plastics collected in the washing and dehydration process are washed and dehydrated, and plastics with different specific gravity are separated by centrifugation. For example, it can be divided into separated plastics containing vinyl chloride resin and polyethylene terephthalate with a specific gravity of 1 or more that sink in water, and separated plastics containing olefin resins such as polyethylene and polypropylene that do not contain vinyl chloride resin. Further fractionation is possible by changing the specific gravity by appropriately changing the blending ratio of the liquid used in floating fractionation, for example, water and organic solvent or salt.

After rough separation and recovery using specific gravity separation, advanced separation may be performed using electrostatic separation that takes advantage of the inherent charging characteristics of plastics.

One specific method is to separate a pre-charged plastic mixture by dropping it between parallel plate electrodes to which a voltage is applied. It is also possible to separate combinations of plastics with small differences in specific gravity that are difficult to separate using specific gravity separation.

(4) Recovery and reuse of cleaning solution (Step 4)
The water, cleaning liquid, or stripping agent used in steps 1 and 2 is supplied to one or more recycling machines selected from a filter, a centrifuge, and an ultrafilter to recover the solids. It will be reused after being removed. While carrying out the wet grinding process and the specific gravity separation process in steps 1 and 2, the water, cleaning liquid, or stripping agent reuse process may be continuously operated to separate the solids from the water, cleaning liquid, or stripping agent. can.

(5) Drying of plastic separated material (Step 5)
The recovered laminate separated and recovered in step 3 is dried into film pieces by one or more methods selected from reduced pressure heat drying, hot air drying, and pressure compression drying in order to remove residual moisture. . As a pre-treatment for producing recycled pellets in step 5, after or during the drying of the recovered film pieces, a processing machine such as a pellet mill (manufactured by Oike Iron Works Co., Ltd.) or Stella (manufactured by Elcom Co., Ltd.) is used. Briquettes may be produced using a pressure compressor.In the present invention, the plastic film is pulverized into powder, and the pulverized material is pulverized to about 10 to 500 μm, and the density of the pulverized material is high. The pressure and compression step can be omitted.The density varies depending on the material constituting the pulverized material, but a higher density is preferable because it is easier to handle when applied to a kneader.Specifically, it is possible to omit 0 in the dry state. The weight is preferably .03 kg or more, more preferably 0.05 kg or more, more preferably 0.2 kg or more, and even more preferably 0.3 kg or more.

(6) Production of recycled pellets (Step 6)
The film pieces or briquettes dried in step 5 are put into a single-screw and two-screw molding machine to produce recycled pellets. The conditions of the kneading machine are not particularly limited, but it is preferable to operate the kneading machine at a temperature of 180 to 240°C in order not to significantly deteriorate the resin performance before recycling.

EXAMPLES Below, the contents and effects of the present invention will be explained in more detail with reference to Examples. In addition, the films, printing inks, reactive adhesives, and organic solvents used as raw materials in each example and comparative example are shown below.

(Plastic film used)
OPP: Biaxially oriented polypropylene film (manufactured by Toyobo Co., Ltd., P2161)
Thickness 20 μm, main raw material polypropylene homopolymer CPP: unstretched polypropylene film (manufactured by Toyobo Co., Ltd., P1128)
Thickness 35μm, main raw material polypropylene random copolymer (printing ink)
INK1: Glosser 507 primary color indigo S2 (manufactured by DIC Graphics Co., Ltd.)
INK2: Finart R507 primary color indigo (manufactured by DIC Graphics Co., Ltd.)
INK2: Finart R794 White G3 (manufactured by DIC Graphics Co., Ltd.)
(reactive adhesive)
AD1: Solvent adhesive Dick Dry 2-component adhesive (ether adhesive) between LX-401A and SP-60 (manufactured by DIC Corporation)
AD2: Solvent-free adhesive Dick Dry 2K-SF-400A and HA-400B two-component adhesive (ester adhesive) (manufactured by DIC Corporation)
(Manufacturing method of laminated film)
The laminated film was created by printing the target film using the following printing method and then laminating the target film together using the following laminating method. The layer structure of the film, the reactive adhesive, and the type of printing ink were determined according to the combinations shown in Table 1.

(Printing method)
Gravure ink and flexo ink, which are printing inks, were spread on a film "Film1" using a proofer.

(Lamination method)
The reactive adhesive "AD" was applied with a laminator to the surface of the film "Film 1" on which the printing ink was spread, so that the coating amount was 3 g/m ² in solid content, and the film "Film 2" was prepared. Pasted with. The bonded laminated film was subjected to an aging reaction at 40° C. for 72 hours. Laminated films "LAM1" to "LAM2" shown in Table 1 were obtained.

Single films "FilmA" to "FilmB", "Print C" (front printing) spread on FilmA, and laminated films "LAM1" to "LAM2" (back printing laminate) were cut into 2 cm x 6 cm size test pieces. I got it.

(Step 1)
PRO1: MultiDrive manufactured by IKA was used and operated at 20,000 rpm for 2 minutes, and the size after crushing was about 5 mm to 20 mm.
PRO2: Using a Super Mascolloider manufactured by Masuko Sangyo Co., Ltd., the material was pulverized at 1500 rpm until the size after crushing (the longest diameter of the pulverized material) was approximately 500 μm or less. The size of the pulverized material is distributed in the range of about 20 μm to 500 μm, and the mode diameter (modest value) is about 100 to 200 μm.

In step 1, pulverization was performed in water.

(Step 2)
For "Print C" and "LAM1" to "LAM2", Step 2 was performed using a homodisper and stirring at 200 rpm for 10 minutes while keeping the liquid temperature at 70°C.

The ink cleaning agent used in Step 2 was prepared by mixing the solvent shown in Table 2 with 2% by weight of potassium hydroxide to prepare the ink cleaning agent shown in Table 3.

(Ink removability from laminated film)
The cleaning results in Tables 4 and 5 show the state of ink removal from the film after performing step 2. After washing the laminated film in each washing process and drying it, the area of the ink removal property of the printed part was calculated by image processing of the photograph taken using an optical microscope, and the ink removal rate was calculated using the following formula. The determination was made by asking for.
Ink removal rate (%) = (1 - ink adhesion area after cleaning/ink adhesion area before cleaning) x 100
◎: 100% of the printed area was removed.
○: 75% or more but less than 100% of the printed area is removed.
〇△: 50% or more and less than 75% of the printed part or laminated part was removed.
×: No peeling at all to less than 50% removed.
Note that ◎ and ○ are within a range that causes no practical problems.

(dehydration, drying)
The crushed and crushed film was collected using a PP non-woven filter bag of 1 μm manufactured by 3M, and dehydrated at 3000 rpm for 5 minutes using a compact high-speed dehydrator Dry Cyclone HS-S60A manufactured by High Smart Japan, and set at 80 ° C. The fluff was dried in a dryer for 3 hours to obtain dried fluff.

(Pelletization using an extruder)
The obtained dried fluff was melt-kneaded using a twin-screw extruder (manufactured by Technovel Co., Ltd., KZW15) at 200° C. and 150 rpm to produce pellets.

(Press molding, punching)
The obtained pellets were press-molded using an electric-hydraulic heating press machine 4B00 manufactured by Imoto Seisakusho, using a mold with a thickness of 1 mm, and under conditions of 210° C. and 30 MPa for 2 minutes. Thereafter, it was punched out using a standard 5B dumbbell manufactured by Super Dumbbell Co., Ltd., and left to stand in a constant temperature and humidity room for about 24 hours.

(Tensile test)
The punched dumbbell test piece was lengthened at a tensile speed of 200 mm/min using a Tensilon tensile tester (model: RTF-1210, manufactured by A&D Co., Ltd.) in a measurement atmosphere of 23°C and 50% RH. The strength and elongation measured at break when pulled in the transverse direction were recorded.

The weight average molecular weight was determined using a high-temperature GPC HLC-8321GPC/HT manufactured by Tosoh Corporation, using a pellet obtained by an extruder with a TSKgel GMHHR-H (20)HT column and 1,2,4-trichlorobenzene as an eluent. (TCB) + BHT, measured at a measurement temperature of 140° C., a flow rate of 1 mL/min, and a sample injection volume of 300 L, to obtain Mw in terms of polystyrene.

In the MFR, 8 g of pellets obtained by an extruder were put into a cylinder, and the temperature was raised to 230°C. Under a load condition of 2.16 kgf, the resin extruded from the die at the bottom of the cylinder was measured every minute, the amount of resin per 10 minutes was calculated, and the average value was calculated to obtain the MFR value.

From this result, the weight average molecular weight of the example was lower than that of the comparative example, and the value of the melt flow rate was able to be increased. For example, a polypropylene homopolymer for general injection molding is required to have a weight average molecular weight of about 300,000 and a melt flow rate of about 10 (cm ³ /10 min). The pulverized film product of the invention was able to change the physical properties of a resin derived from a plastic film to properties suitable for a resin for injection molding.

Claims (11)

A method for producing a molding material or a material for molding, which comprises a step of pulverizing resin derived from a plastic film into pieces of 1 mm or less. The method for producing a molding or molding material according to claim 1, wherein the weight average molecular weight (Mw2) of the molding or molding material after pulverization is smaller than the weight average molecular weight (Mw1) of the resin derived from the plastic film before pulverization. . The method for producing a molding material or a molding material according to claim 1 or 2, wherein the resin derived from the plastic film contains at least an olefin resin. The method for producing a molding or molding material according to claim 3, wherein the weight average molecular weight (Mw2) of the molding or molding material after pulverization is 450,000 or less. The method for producing a molding or molding material according to claim 3, wherein the molding or molding material after pulverization has a melt flow rate of 5 or more. The plastic film is a laminated film having at least the plastic film layer and another plastic layer different from the plastic layer, a layer selected from a vapor deposited film layer and a metal foil layer, or an ink film is formed on the plastic film. The method for producing a molding material or a molding material according to claim 1 or 2, wherein the film is a film having layers. 7. The method for producing a molding material or molding material according to claim 6, comprising the step of stirring the pulverized material after the pulverization in a release agent to obtain a pulverized material having a single layer structure. 8. The method for producing a molding material or a molding material according to claim 7, further comprising the step of separating and recovering each layer of the single-layered pulverized material. The method for producing a molding material or a molding material according to claim 1 or 2, wherein the pulverized material after the pulverization is collected, and the collected material is dried and then processed into pellets. A molding or molding material containing a resin derived from a plastic film, which is pulverized to a size of 1 mm or less. A molding or molding material containing a resin derived from a plastic film, the molding or molding material having a weight average molecular weight (Mw2) of 450,000 or less.