JP7234487B1 - Laminate separation and collection method - Google Patents

Abstract

An object of the present invention is to provide excellent releasability of the printed layer and adhesive layer even under conditions where the amount of the printed layer during detachment is large, and to suppress reattachment of the detached printed layer components. To provide a method for separating and recovering a laminated body suitable for plastic recycling. A further object of the present invention is to provide a method for producing a high-quality molding material obtained by heat-molding the collected plastic base material. A laminate comprising at least a plastic base layer and a printed layer is immersed in a desorption liquid, and the printed layer is separated from the plastic base layer by the volume-based median diameter (D50) of the components of the printed layer. A method for separating and recovering a laminate, comprising a step of recovering a plastic substrate by desorbing so that the thickness is 1 μm or more, wherein the printed layer is 0.01 mass with respect to the total mass of the desorbing liquid % or more, a method for separating and recovering a laminate. [Selection figure] None

Description

TECHNICAL FIELD The present invention relates to a method for separating and recovering a laminate comprising at least a plastic substrate layer and a printed layer.

In recent years, packages, plastic bottles, and other plastic products made from plastic film have been discarded or dumped into the ocean as garbage, causing environmental pollution problems. These plastic products are decomposed in seawater to become submicron-sized fragments (microplastics) and float in seawater. When these microplastics are ingested by marine organisms such as fish, they are concentrated in the bodies of the organisms, and there is concern that they may affect the health of seabirds and humans who consume these marine organisms as food.

Examples of the plastic products include multi-layered food packaging packages using plastic films. In such food packaging packages, polyester base material, nylon base material (NY), polypropylene base material ( PP), polyethylene substrates (PE), etc., are used. These film substrates are printed with printing ink, bonded to other film substrates or hot-melt resin substrates via an adhesive or the like, cut and heat-sealed to form a package. However, such a multi-layered food packaging package has a problem that material recycling cannot be performed as it is because a plurality of incompatible different materials are mixed.

Regarding the material recycling of such multilayer packaging materials, for example, Patent Documents 1 and 2 disclose that a laminate provided with a release layer containing a polyurethane resin having a predetermined acid value is treated with an alkaline aqueous solution, Techniques for detaching a printed layer from laminates having a multi-layer structure as well as a surface printing structure have been disclosed.

Further, Patent Document 3 describes a technique for detaching the printed layer from the polyester substrate by immersing a laminate having a polyester substrate and a printed layer in an aqueous sodium hydroxide solution and stirring under certain conditions. there is

JP 2020-090627 A JP 2021-098294 A Japanese Patent Publication No. 2022-510105

However, in the desorption steps described in Patent Documents 1 to 3, if the treatment amount of the laminate with respect to the alkaline aqueous solution is increased in order to improve the treatment efficiency, the desorption property is lowered. In addition, since the print layer components in the treatment liquid also increase, the print layer after detachment tends to reattach to the substrate. Furthermore, if the stirring speed is increased in order to improve the releasability, there arises a problem that the detached printed layer is finely dispersed and reattached to the plastic substrate more easily. Here, the term "re-adhesion" means that a detachable layer such as a printed layer or an adhesive layer that has detached from a base material is finely dispersed by agitation and re-adheres to the base material. It causes coloration and deteriorates the properties of recycled materials. That is, the molding material obtained by recycling the base material to which the printed layer has been reattached as described above causes deterioration in appearance and deterioration in physical properties due to coloring.

Therefore, the problem of the present invention is that even under conditions where the amount of the printed layer during the detachment process is large, the printed layer and the adhesive layer are excellent in releasability, and the reattachment of the detached printed layer components is suppressed. Another object of the present invention is to provide a method for separating and recovering a laminate suitable for plastic recycling. A further object of the present invention is to provide a method for producing a high-quality molding material obtained by heat-molding the recovered plastic base material.

That is, in the present invention, a laminate comprising at least a plastic substrate layer and a printed layer is immersed in a desorption liquid and stirred or shaken, and the printed layer is removed from the plastic substrate layer, based on the volume of the printed layer components. A method for separating and recovering a laminate, comprising a step of desorbing so that the median diameter (D50) of the laminate is 1 μm or more and recovering the plastic substrate,
It relates to a method for separating and recovering a laminate, wherein the content of the printed layer is 0.01% by mass or more with respect to the total mass of the desorbing liquid.

The present invention also relates to the laminate separating and recovering method described above, wherein the desorbed print layer component has a span value A represented by the following formula of 10 or less.
A = (D90-D10)/D50
D10: Cumulative 10% diameter of the volume-based particle size distribution obtained by laser diffraction particle size distribution measurement of the detached print layer component D90: Volume-based particle size distribution obtained by laser diffraction particle size distribution measurement of the detached print layer component Cumulative 90% diameter

The present invention also relates to a method for separating and recovering the laminate, wherein the plastic substrate layer is a polyolefin substrate.

Further, the present invention provides separation of the above laminate, wherein the desorbing liquid contains water and a surfactant, and the content of the surfactant is 0.001% by mass or more in the total mass of the desorbing liquid. Regarding the collection method.

Further, in the present invention, the printed layer contains a colorant, a binder resin, and a dispersant, and the content of the dispersant is 0.01% by mass or more with respect to the total mass of the colorant. It relates to a method for separating and recovering bodies.

The present invention also relates to the method for separating and recovering the laminate, wherein the dispersant contains a pigment derivative and/or a resin type dispersant.

The present invention also relates to the method for separating and recovering the laminate, wherein the dispersant contains a pigment derivative, and the content of the pigment derivative is 0.01 to 10% by mass with respect to the total mass of the colorant.

The present invention also relates to the method for separating and recovering the laminate, wherein the content of the laminate is 1.5% by mass or more with respect to the total mass of the desorbing liquid.

The present invention also relates to a method for separating and recovering the above laminate, wherein the stripping liquid is a basic aqueous solution, and the step of stripping the printed layer in the basic aqueous solution to recover the plastic base material.

The present invention also relates to a method for producing a molding material, which comprises melt-kneading the plastic base material recovered by the method for separating and recovering a laminate described above.

The present invention also relates to a method for producing a molded article, characterized by thermoforming the molding material obtained by the above-described production method.

According to the present invention, even under conditions where the amount of the printed layer during the detachment process is large, the printed layer and the adhesive layer are excellent in detachability, and furthermore, reattachment of the detached printed layer components is suppressed. It is possible to provide a method for separating and recovering a laminate suitable for Furthermore, it is possible to provide a method for producing a high-quality molding material obtained by heat-molding the recovered plastic base material.

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

In the method for separating and recovering a laminate of the present invention, a laminate comprising at least a plastic substrate layer and a printed layer is immersed in a desorption liquid, and the printed layer is separated from the plastic substrate layer. Desorption is performed so that the standard median diameter (D50) is 1 μm or more, and a step of recovering the plastic substrate is included, and the printed layer is 0.01% by mass or more with respect to the total mass of the desorption liquid. characterized by being

In the separation and recovery of the laminate, if the amount of the laminate relative to the desorbing liquid is increased in order to improve the processing efficiency, the amount of the printed layer relative to the desorbing liquid also increases, so the removability deteriorates, and furthermore, the removability deteriorates. Subsequent print layer components are more likely to reattach to the substrate after detachment. Furthermore, since the collision frequency of the laminate increases under stirring conditions, the printed layer components tend to decrease after detachment.

The inventors have found that under conditions where the amount of the printed layer relative to the desorbing liquid is large, the median diameter (D50) of the components of the printed layer after desorption is 1 μm or more, thereby making the printed layer excellent. It was found that reattachment can be effectively suppressed while maintaining detachability. This is considered to be due to proper control of the mobility of the detached printing layer components in the detaching liquid and the polarity of the surface.

In order to detach the printed layer component of the detachment layer so that the median diameter is 1 μm or more, the detachment test conditions such as the stirring speed are selected, and the detachment liquid contains a surfactant. , including a dispersing agent in the printed layer, but the present invention is not limited to this, and it is preferable to combine each means appropriately. Details of each means will be described later.

<Separation and recovery method>
In the method for separating and recovering a laminate of the present invention, a laminate comprising at least a plastic substrate layer and a printed layer is immersed in a desorption liquid, and the printed layer is separated from the plastic substrate layer. It includes a step of desorbing so that the standard median diameter (D50) is 1 μm or more, and recovering the plastic substrate.
In the present invention, the term "detachment" means that the base material is detached from the laminate by dissolving or swelling the detachment layer with the detachment liquid, and (1) the detachment layer is dissolved. (2) Even if the detachable layer does not dissolve, it is peeled off due to neutralization, swelling, etc., and the substrate is detached.

Since the purpose of the present invention is to obtain a plastic base material after desorption as a recycled base material or a recycled base material, it is preferable to remove as many desorption layers and the like as possible from the plastic base material. Specifically, it is preferable that at least 50% by mass or more of 100% by mass of the desorption layer is desorbed in the area or film thickness direction. More preferably 60% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more are desorbed.

<Particle Size Distribution of Detached Printed Layer Components>
In the present invention, the volume-based median diameter (D50) and span value A of the printed layer components separated from the plastic substrate layer are measured by a laser diffraction particle size distribution analyzer. The span value A is represented by the following formula.
A = (D90-D10)/D50
D10: Cumulative 10% diameter of the volume-based particle size distribution obtained by laser diffraction particle size distribution measurement of the detached print layer component D90: Volume-based particle size distribution obtained by laser diffraction particle size distribution measurement of the detached print layer component Cumulative 90% diameter

In the present invention, it is important that the median diameter of the separated printing layer components is 1 μm or more. When the median diameter of the removed print layer components is 1 μm or more, it is possible to prevent the removed print layer components from reattaching to the base material as described above, and to obtain a high-performance recycled material. The median diameter of the separated print layer components is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 15 μm or more, and particularly preferably 20 μm or more. The median diameter of the detached printing layer components is preferably 1000 μm or less, more preferably 800 μm or less. A median diameter of 1000 μm or less is preferable because separation of the base material and the printed layer components after detachment is facilitated.

The span value A represents the particle size distribution width of the detached print layer component, and the larger the value, the wider the particle size distribution width, and the more likely it is to contain fine print layer components that are likely to reattach to the substrate.
The span value A is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less. A span value of 10 or less is preferable because reattachment of the detached printed layer can be suppressed.

<Desorption liquid>
The detachment liquid may swell and dissolve the detachable layer, and can be appropriately selected in consideration of ease of detachment of the detachable layer, which will be described later. Examples of such desorbing liquids include water, basic aqueous solutions, and acidic aqueous solutions. These desorbed liquids may be heated.
From the viewpoint of removing a urethane-based adhesive layer commonly used in packaging materials, the removing liquid is more preferably a basic aqueous solution containing a basic compound.

[Surfactant]
The desorption liquid preferably contains water and a surfactant. A surfactant mainly plays a role of improving the detachability of the detachable layer. This is probably because the action of the surfactant facilitates penetration of the stripping liquid into the stripping layer such as the primer layer, the printing layer, and the adhesive layer, thereby promoting the strippability. In addition, the median diameter of the print layer components detached in the detaching liquid can be easily controlled to 1 μm or more. In addition, when the amount of the laminate relative to the desorbing liquid is increased in the separation and recovery, the laminate and the separated base material tend to curl with the desorbed ink pieces involved, and even if they are immersed in the desorbing liquid. However, it is difficult to cleanly remove ink fragments and the like caught in the curl. However, since the desorption liquid contains a surfactant, the surfactant is adsorbed on the surfaces of the laminate and the separated base material, thereby suppressing curling. As a result, detachability is improved and reattachment can be suppressed.
Furthermore, when the stripping liquid contains a surfactant, it is possible to strip the printed layer in contact with the plastic substrate without the stripping layer.

The HLB value is an index value related to the affinity of a surfactant for water and oil, and is divided equally by setting the HLB value of a substance having no hydrophilic group to 0 and the HLB value of a substance having only a hydrophilic group to 20. be. The concept of HLB was proposed by William Griffin of the Atlas Powder Company in 1949, and several calculation methods have been proposed.
Formula) HLB = 20 x [(molecular weight of hydrophilic group contained in surfactant)/(molecular weight of surfactant)]
Hydrophilic groups contained in surfactants include, for example, hydroxyl groups and ethyleneoxy groups.

The HLB value of the surfactant in the present invention is preferably 7 or more. When the HLB is 7 or more, excellent deinking properties and reattaching properties are exhibited. The HLB value of the surfactant is preferably 8 or higher, more preferably 10 or higher. The HLB value of the surfactant is preferably 20 or less, more preferably 19 or less, and even more preferably 17 or less. When the HLB value is 20 or less, the defoaming property is excellent, which is preferable.

Types of surfactants include, for example, nonionic, anionic, cationic, and amphoteric surfactants, and suitable types and blending amounts can be appropriately selected and used according to required properties. From the viewpoint of releasability and foamability, it is preferably at least one selected from the group consisting of anionic surfactants and nonionic surfactants.
Further, the surfactant has a structure to which an alkylene oxide (hereinafter also referred to as AO) is added, so that deinking property and reattachment property are improved, which is preferable.

(Nonionic surfactant)
Although the nonionic surfactant is not particularly limited, it is preferably an alkylene oxide adduct to which alkylene oxide is added. More preferred are compounds obtained by adding alkylene oxide to alcohols having active hydrogen, compounds obtained by adding alkylene oxide to amines, or compounds obtained by adding alkylene oxide to fatty acids. The addition may be either random addition or block addition. Also, the carbon number of the alkylene oxide is preferably 2 to 4 carbon atoms.
More preferred nonionic surfactants are alcohol-based nonionic surfactants obtained by adding an alkylene oxide having 2 to 4 carbon atoms to an alcohol.

[Alcohol-based nonionic surfactant]
Examples of alcohol-based nonionic surfactants include alkylene oxide adducts of primary or secondary alcohols having a total carbon number of 8 to 24, or alkylene oxide adducts of alkylphenols having a total carbon number of 8 to 12. be done. The primary or secondary alcohol having a total carbon number of 8 to 24 may be either saturated or unsaturated.
Examples of primary or secondary alcohols having a total carbon number of 8 to 24 include lauryl alcohol, stearyl alcohol, oleyl alcohol, dodecyl alcohol, arachidyl alcohol, behenyl alcohol, lignoceryl alcohol, and myristyl alcohol.
Examples of the alkylene oxide to be added to the alcohol include ethylene oxide, propylene oxide and butylene oxide, and ethylene oxide is preferably essential. The number of moles of alkylene oxide to be added is preferably 1 to 100 mol, more preferably 2 to 50 mol, per 1 mol of alcohol or alkylphenol. It is preferable that it is in the above range because it is particularly excellent in releasability.

[Fatty acid-based nonionic surfactant]
The structure of the fatty acid-based nonionic surfactant is not particularly limited. Examples include oils and fats composed of esters of higher fatty acids and glycerin, and alkylene oxide adducts of mixtures of the above oils and fats and 2 to 10 polyhydric alcohols. The higher fatty acid having 10 to 24 total carbon atoms may be either saturated or unsaturated.
Examples of the higher fatty acids having 10 to 24 carbon atoms in total include saturated higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, and behenic acid; palmitoleic acid, oleic acid, elaidic acid, linoleic acid, unsaturated higher fatty acids such as linolenic acid, erucic acid and ricinoleic acid; Dihydric to decahydric polyhydric alcohols include ethylene glycol, propylene glycol, glycerin, polyglycerin, sorbitol, sorbitan, sucrose and the like. The type and number of moles of alkylene oxide to be added are the same as those described in the section [Alcoholic Nonionic Surfactant] above.

[Amine-based nonionic surfactant]
Amine-based nonionic surfactants include AO adducts of saturated or unsaturated primary or secondary amines having a total carbon number of 8 to 36. Amines include 2-ethylhexylamine, di-2-ethylhexylamine, laurylamine, dilaurylamine, tetradecylamine, ditetradecylamine, hexadecylamine, dihexadecylamine, stearylamine, distearylamine, oleylamine, di and oleylamine. Moreover, the kind of AO and the number of added moles are the same as above.

(Anionic surfactant)
The anionic surfactant is preferably a non-soap surfactant, such as a sulfonate anionic surfactant, a sulfate ester anionic surfactant, a carboxylic acid anionic surfactant, a phosphate ester anionic surfactant. active agents.

[Sulfonic acid-based anionic surfactant]
Examples of the sulfonic acid anionic surfactant include alkylsulfonic acid, alkylbenzenesulfonic acid, alkylnaphthalenesulfonic acid, alkyldiphenyletherdisulfonic acid, alkylmethyltaurine, sulfosuccinic acid diester, alkylene oxide adduct of sulfonic acid, and these. salt of Specific examples include hexanesulfonic acid, octanesulfonic acid, decanesulfonic acid, dodecanesulfonic acid, toluenesulfonic acid, cumenesulfonic acid, octylbenzenesulfonic acid, dodecylbenzenesulfonic acid, dinitrobenzenesulfonic acid, and lauryldodecylphenyl ether disulfone. An acid or the like can be used.

[Sulfuric Acid Ester-Based Anionic Surfactant]
Examples of the above-mentioned sulfate ester-based anionic surfactants include sulfate esters (alkyl ether sulfate esters), alkylene oxide adducts of sulfate esters, and salts thereof. Specific examples include lauryl sulfuric acid, myristyl sulfuric acid, polyoxyethylene lauryl ether sulfuric acid, and the like.

[Carboxylic acid-based anionic surfactant]
Examples of the carboxylic acid-based anionic surfactants include alkylcarboxylic acids, alkylbenzenecarboxylic acids, alkylene oxide adducts of carboxylic acids, and salts thereof. Specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, polyoxyethylene lauryl ether acetic acid, and polyoxyethylene tridecyl ether acetic acid.

[Phosphate Ester Anionic Surfactant]
Examples of the phosphate ester-based anionic surfactants include phosphate esters (alkyl ether phosphate esters), alkylene oxide adducts of phosphate esters, and salts thereof. Specific examples include octyl phosphate, lauryl phosphate, tridecyl phosphate, myristyl phosphate, cetyl phosphate,
Stearyl phosphate, polyoxyethylene octyl ether phosphate, polyoxyethylene lauryl ether phosphate, and the like can be used.

The anionic surfactant preferably has an alkyl group of 2 to 24 carbon atoms or an alkenyl group of 2 to 24 carbon atoms, more preferably an alkyl group of 8 to 18 carbon atoms. The alkyl group or alkenyl group may be linear or branched.
When the anionic surfactant is an alkylene oxide adduct, examples of the alkylene oxide include ethylene oxide, propylene oxide and butylene oxide, with ethylene oxide being preferred. The number of moles of alkylene oxide to be added is preferably 1 to 12 mol, more preferably 1 to 8 mol, per 1 mol of alcohol or alkylphenol. It is preferable that it is in the above range because it is particularly excellent in releasability.

Examples of salts constituting the above-mentioned anionic surfactants include metal salts of sodium, potassium, magnesium, calcium and the like. These salts may be used individually by 1 type, and may be used in combination of 2 or more type.
Among them, the anionic surfactant is preferably a sulfonate type or a phosphate type, more preferably an alkyl sulfonate or a polyoxyalkylene alkyl ether sulfonate, from the viewpoint of desorption and reattachment properties. , polyoxyalkylene alkyl ether phosphate, and the like.

(Cationic surfactant)
Examples of cationic surfactants include alkylamine salts and quaternary ammonium salts. Specifically, stearylamine acetate, trimethylyac ammonium chloride, trimethyl tallow ammonium chloride, dimethyldioleyl ammonium chloride, methyloleyl diethanol chloride, tetramethylammonium chloride, laurylpyridinium chloride, laurylpyridinium bromide, laurylpyridinium disulfate, cetylpyridinium bromide. , 4-alkylmercaptopyridine, poly(vinylpyridine)-dodecyl bromide, dodecylbenzyltriethylammonium chloride and the like can be used.

(Amphoteric surfactant)
Examples of amphoteric surfactants include betaine lauryldimethylaminoacetate, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, betaine coconut fatty acid amidopropyldimethylaminoacetate, polyoctylpolyaminoethylglycine, and imidazoline. derivatives.

These surfactants may be used alone or in combination of two or more. The content of the surfactant in the desorbed liquid is preferably in the range of 0.001 to 10% by mass, more preferably in the range of 0.005 to 7% by mass, based on the mass of the desorbed liquid. , more preferably 0.03 to 5% by mass, still more preferably 0.05 to 3% by mass. When the amount is 0.001% by mass or more, the deinking property is excellent, and the median diameter of the separated print layer components can be easily controlled to 1 μm or more.

[Antifoaming agent]
In the present invention, it is also preferred that the desorbing liquid further contains an antifoaming agent. By using the antifoaming agent in combination with the surfactant described above, good antifoaming properties can be exhibited without deteriorating the detachability and reattachment properties, and foaming due to the surfactant can be suppressed. Antifoaming agents include, for example, silicone compounds and non-silicone compounds.

(Silicone-based compound)
Examples of the silicone compound include emulsion type, self-emulsifying type, oil type, oil compound type, and solvent type.
Emulsion type is a silicone antifoaming agent made into an O / W type emulsion by emulsifying a silicone oil compound with an active agent. Examples include “FC2913” and “SILFOAMSE47” manufactured by Wacker Silicone, and “BYK-015” and “BYK-1640” manufactured by BYK-Chemie Japan.
The self-emulsifying type is a silicone-based antifoaming agent containing 100% active ingredients that becomes an emulsion state by diluting and mixing with water. , "SILFOAM SD670" and "SILFOAM SD850" manufactured by Asahi Kasei Wacker Silicone.
The oil type is a 100% silicone oil defoaming agent that does not contain solvents or additives. AK12500” and “BYK-1770” manufactured by BYK-Chemie Japan.
The oil compound type is a silicone antifoaming agent in which silica particles are blended with silicone oil. "PULPSIL22274VP", BYK-Chemie Japan's "BYK-017" and "BYK-018" are mentioned.
The solvent type is a silicone antifoaming agent obtained by dissolving silicone oil in a solvent. and "BYK-025".

(Non-silicone compound)
Examples of the non-silicone compounds include fatty acid ester compounds, urea resin compounds, paraffin compounds, polyoxyalkylene glycol compounds, acrylic ester copolymers, ester polymers, ether polymers, and amide polymers. mineral oil emulsified type, polysiloxane adduct, fluorine compound, vinyl polymer, acetylene alcohol, acrylic polymer, special vinyl polymer, ethylene glycol, higher alcohol (octyl alcohol, cyclohexanol, etc.).

An antifoaming agent may be used individually by 1 type, and may use 2 or more types together. The content of the antifoaming agent in the desorbed liquid is preferably in the range of 0.0001 to 5% by mass, more preferably in the range of 0.001 to 4.5% by mass, based on the mass of the desorbed liquid. , more preferably 0.01 to 4% by mass, still more preferably 0.02 to 3.5% by mass, and particularly preferably 0.03 to 3% by mass. When it is 0.0001% by mass or more, the antifoaming property is excellent, and when it is 5% by mass or less, the deinking property and reattachment property are excellent.

The antifoaming agent has good alkali resistance, and when combined with the surfactant, it is difficult to reduce the deinking property and reattachment property. , and non-silicone compounds.

[Basic compound]
As described above, the stripping solution used in the present invention is preferably a basic aqueous solution containing a basic compound from the viewpoint of stripping the urethane-based adhesive layer that is commonly used in packaging materials.
The basic compound is not particularly limited, and examples thereof include sodium hydroxide (NaOH), potassium hydroxide (KOH), calcium hydroxide (Ca(OH) ₂ ), ammonia, barium hydroxide (Ba(OH) ₂ ), Sodium carbonate _{( Na2CO3} ) is preferably used. More preferably, it is at least one selected from the group consisting of sodium hydroxide and potassium hydroxide.
The content of the basic compound in the basic aqueous solution is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, and still more preferably 3 to 15% by mass, based on the mass of the basic aqueous solution. Range. Within the above range, the basic aqueous solution retains sufficient basicity to dissolve or swell the detachable layer, which will be described later, to detach and recover the plastic substrate.

The release liquid permeates from the end portion of the laminate, contacts the release layer, dissolves or swells, and separates the plastic substrate and the release layer. Therefore, in order to proceed with the desorption step efficiently, it is preferable that the laminate is cut or pulverized and the desorption layer is exposed in the cross section when immersed in the desorption liquid. In such a case, the substrate layer can be removed in a shorter time.

The laminate when the laminate is separated in the desorbing liquid is preferably 0.1% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 8% by mass or less, relative to the total mass of the desorbing liquid. , more preferably 1.5% by mass or more and 7% by mass or less, still more preferably 2% by mass or more and 6% by mass or less. A content of 0.1% by mass or more is preferable from the viewpoint of treatment efficiency. A content of 10% by mass or less is preferable from the viewpoint of releasability.

The printed layer when the laminate is separated in the desorption liquid is 0.01% by mass or more, preferably 0.05% by mass or more and 1% by mass or less, more preferably 0.01% by mass or more, relative to the total mass of the desorption liquid. is 0.1% by mass or more and 0.5% by mass or less. A content of 0.01% by mass or more is preferable from the viewpoint of treatment efficiency. When it is 1% by mass or less, it is preferable from the viewpoint of reattachment.

The temperature of the desorption liquid when the laminate is immersed is preferably 25 to 120.degree. C., more preferably 30 to 120.degree. C., and particularly preferably 30 to 80.degree. The immersion time in the desorbing solution is preferably 1 minute to 24 hours, more preferably 1 minute to 12 hours, still more preferably 1 minute to 6 hours. In order to improve desorption efficiency, it is preferable to stir or shake the desorbed liquid, circulate it, or the like. The rotation speed is preferably 80-5000 rpm, more preferably 80-4000 rpm.

After removing the release layer from the laminate and recovering the plastic base material, the recycled base material can be obtained through the steps of washing and drying the obtained plastic base material. The removal rate of the desorption layer on the surface of the substrate is preferably 70% or more, more preferably 80% or more, particularly preferably 90% or more, relative to the area of the desorption layer before desorption.
Further, the obtained recycled base material can be processed into pellets by an extruder or the like and reused as a recycled resin.

<Laminate>
The laminate used in the present invention comprises at least a plastic substrate layer and a printed layer. By removing the layer in contact with the plastic substrate with the above-described desorption liquid, the plastic substrate can be recovered and recycled. In the present invention, it is preferable to provide a release layer in contact with the plastic substrate layer in order to improve the release property.

<Print layer>
In the present invention, the printed layer is an essential component, and may be provided in contact with the plastic substrate, or may be provided in contact with the primer layer when the laminate has a primer layer. The printed layer is a layer that forms an arbitrary printed pattern for the purpose of decoration, imparting aesthetics, content, expiration date, manufacturer's or seller's indication, etc., and includes a solid printed layer. The printed layer may be formed from a single layer or multiple layers.
When the printed layer contains a water-soluble resin or a compound having an acidic group, which will be described later, it also functions as a release layer.
The printing ink used to form the printing layer can be produced by dissolving and/or dispersing at least a colorant, a dispersant, and a binder resin in a solvent, and optionally contains other components. may

[Coloring agent]
The printing layer may be colored or colorless and contains known colorants used in printing inks and paints. Such coloring agents are not particularly limited, and in addition to inorganic pigments, organic pigments, and dyes, metal powders that impart metallic luster, near-infrared absorbing materials, and ultraviolet absorbing materials may be used.
Examples of inorganic pigments include colored pigments such as titanium oxide, red iron oxide, Prussian blue, ultramarine blue, carbon black and graphite; and extender pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide and talc.
As organic pigments, soluble azo pigments, insoluble azo pigments, azo chelate pigments, condensed azo pigments, copper phthalocyanine pigments, condensed polycyclic pigments and the like are preferably used.
It should be noted that the above pigments are not limited to these, and those listed in the generic names of the Color Index can be used as appropriate. Among them, when the removing liquid is a basic aqueous solution, a pigment having alkali resistance that does not dissolve in the basic aqueous solution is preferable. Preventing the elution of the pigment facilitates reuse of the aqueous base solution.
The alkali resistance of a pigment is generally estimated based on the skeleton or structure of the pigment. I. Pigment Blue 15, C.I. I. Pigment Yellow 83 can be mentioned.
When the pigment is titanium oxide, the content of titanium oxide in the printed layer is preferably 20-80% by mass, more preferably 30-75% by mass. When the pigment is an inorganic pigment other than titanium oxide, an extender pigment, or an organic pigment, the content of these pigments in the printed layer is preferably 0.5 to 60% by mass, more preferably 10 to 50% by mass. % by mass.

[Dispersant]
The print layer contains a pigment derivative and/or a resin-type dispersant as a dispersant for the colorant, thereby improving releasability. In addition, the median diameter of the print layer components detached in the detaching liquid can be easily controlled to 1 μm or more. Furthermore, the dispersion stability and aging stability of the ink are improved. Although these may be used alone, they are preferably used in combination because the dispersion stability and the stability over time are further improved.

(pigment derivative)
A pigment derivative is a compound in which a substituent is introduced into the skeleton of a pigment. In the printing ink, the pigment skeleton of the pigment derivative adsorbs to the surface of the pigment in the printing ink, and the substituent moiety of the pigment derivative is oriented toward the solvent in the printing ink, thereby dispersing the pigment in the printing ink. have.
Pigment derivatives include, for example, phthalocyanine-based, azo-based, anthraquinone-based, and quinacridone-based pigments having functional groups such as carboxyl groups, sulfonic acid groups, carbonyl groups, and sulfonyl groups added to their skeletons, and salts thereof. can be preferably used. These can be used alone or in combination.

Commercially available pigment derivatives include Solsperse 5000, Solsperse 12000 (manufactured by Nippon Lubrizol), BYK-SYNERGIST2100, BYK-SYNERGIST2105 (manufactured by Big Chemie Japan), Efca 6745, Efca 6750 (manufactured by BASF), and the like. can do. These can be used alone or in combination.

The pigment derivative preferably exhibits the same or similar color as the pigment in the ink. For example, when adding to black ink or cyan ink, a phthalocyanine pigment derivative can be preferably used as the pigment derivative.

The total amount of the pigment derivative is preferably 0.01 to 10% by mass, more preferably 0.05 to 6% by mass, and more preferably 0.1 to 4% by mass with respect to the total colorant. More preferred. When it is 0.01% by mass or more, the dispersion stability of the printing ink is improved, and the releasability is also improved. Further, when the content is 0.01 to 10% by mass, the median diameter of the desorbed print layer component can be easily controlled to 1 μm or more, and a high-quality recycled molding material can be reproduced.

(resin type dispersant)
The resin-type dispersant has an affinity site for the pigment composition having the property of adsorbing to the pigment composition and a site compatible with the pigment composition carrier, and adsorbs to the pigment composition to form the pigment composition. It works to stabilize the dispersion in the carrier. Specific examples of resin-type dispersants include polyurethanes, polycarboxylic acid esters such as polyacrylates, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamine salts. , polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, modified products thereof, amides formed by the reaction of poly(lower alkyleneimine) with polyesters having free carboxyl groups, and salts thereof Oily dispersants such as (meth)acrylic acid-styrene copolymer, (meth)acrylic acid-(meth)acrylic acid ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, water-soluble such as polyvinylpyrrolidone Resins, water-soluble polymer compounds, polyesters, modified polyacrylates, ethylene oxide/propylene oxide addition compounds, phosphoric acid esters, etc. are used, and these can be used alone or in combination of two or more. It is not necessarily limited to these.

The total amount of the resin-type dispersant is preferably 0.01 to 30% by mass, more preferably 0.05 to 20% by mass, and 0.1 to 10% by mass with respect to the total colorant. is more preferred. When it is 0.01% by mass or more, the dispersion stability of the printing ink is improved, and the releasability is also improved. Furthermore, it is easy to control the median diameter of the printing layer components detached in the detaching liquid to 1 μm or more. Moreover, when it is 30% by mass or less, the printed layer has good water resistance.

[Binder resin]
Examples of the binder resin for the printing layer include fibrous materials such as nitrocellulose, cellulose acetate and propionate, chlorinated polypropylene, vinyl chloride-vinyl acetate copolymer, polyester, acrylic, urethane resin and acrylic urethane. , polyamide, polybutyral, cyclized rubber, chlorinated rubber, or a suitable combination thereof. When containing a water-soluble resin or a compound having an acidic group, the printed layer also functions as a release layer. These resins may be used individually by 1 type, and may use 2 or more types together.

[Primer layer]
The laminate used in the present invention may have a primer layer. When the laminate has a primer layer, the primer layer is arranged in contact with the plastic substrate, has a water-soluble resin or a compound having an acidic group, and is removed from the plastic substrate by dissolution and peeling with a desorption liquid. It is preferable to play the role of separating.

(Water-soluble resin)
As the water-soluble resin, any resin can be used as long as it can be swelled or dissolved in water and released from the plastic substrate. The water may be heated to a temperature of about 25-100°C. Thereby, the primer layer can be removed with water (including warm water).
Such resins can be selected from known resins as long as they do not impair water solubility. polyallylamine resins, water-soluble phenolic resins, water-soluble epoxy resins, water-soluble phenoxy resins, water-soluble urea resins, water-soluble melamine resins, polyvinyl alcohol resins, and modified products of these resins. These can be used singly or in combination of two or more. Among them, polyvinyl alcohol (PVA) resin is preferably used from the viewpoint of availability and releasability.
When the water-soluble resin has film-forming properties, the water-soluble resin may be used as the binder resin constituting the primer layer.

Polyvinyl alcohol resins include, in addition to unmodified polyvinyl alcohol, modified polyvinyl alcohol obtained by copolymerizing various monomers during the production of vinyl ester resins and saponifying them, and various types of polyvinyl alcohol obtained by post-modification of unmodified polyvinyl alcohol. Various post-modified polyvinyl alcohols into which functional groups have been introduced may be used. Also, modified polyvinyl alcohol may be post-modified. These modification|denaturation can be performed in the range which does not impair the water-solubility of polyvinyl alcohol resin.
These resins may be used individually by 1 type, and may use 2 or more types together.

Preferable polyvinyl alcohol resins include resins containing structural units having primary hydroxyl groups in side chains and ethylene-modified polyvinyl alcohol resins. Among them, a polyvinyl alcohol resin containing a structural unit having a primary hydroxyl group in a side chain is preferable because of its excellent melt moldability and excellent water solubility. The number of primary hydroxyl groups in these structural units is generally 1-5, preferably 1-2, more preferably 1. Moreover, it is preferable to have a secondary hydroxyl group in addition to the primary hydroxyl group.

The degree of saponification (measured according to JIS K 6726) of the polyvinyl alcohol resin used in the present invention is usually 60 to 100 mol%. In addition, the preferred range of saponification degree varies depending on the modified species. 0.5%. The saponification degree of the side chain 1,2-diol structural unit-containing modified polyvinyl alcohol resin is usually 60 to 99.9 mol%, preferably 65 to 99.8 mol%, more preferably 70 to 99.5 mol%. be. If the degree of saponification is too low, the water solubility tends to decrease. The saponification degree of the ethylene-modified polyvinyl alcohol resin modified with a small amount of ethylene is usually 60 mol % or more, preferably 70 to 99.5 mol %, particularly preferably 75 to 99.0 mol %.
When the degree of saponification is within the above range, the water solubility is excellent and the releasability is improved, which is preferable. Moreover, it is preferable because it is excellent in coatability when forming a primer layer.

The average degree of polymerization of the polyvinyl alcohol resin (measured according to JIS K 6726) is generally 100-3000, preferably 150-2000, more preferably 180-1000, particularly preferably 200-800.

(Compound having an acidic group)
As the compound having an acidic group, a resin having an acidic group or a low-molecular-weight compound having an acidic group may be used. As a result, the primer layer can be removed with the basic aqueous solution described above.

Examples of resins having an acidic group include cellulose resins, urethane resins, polyamide resins, vinyl chloride/vinyl acetate copolymers, ketone resins, polyester resins, and (meth)acrylic resins. Examples of the acidic group include a carboxy group, a phosphoric acid group, a sulfo group, a sulfino group, etc., or an ester or salt thereof.
As the resin having an acidic group, a rosin-modified resin having an acid value such as maleated rosin and fumarated rosin can be used.
In addition, as the resin having an acidic group, a polymerizable monomer having a carboxy group such as itaconic acid, maleic acid, fumaric acid, and cinnamic acid; a polymerizable monomer that is an acid anhydride such as itaconic anhydride and maleic anhydride; Polymerizable monomers having a sulfonic acid group such as styrene; Polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide; Polymerizable monomers having an acidic group such as styrene-(meth)acrylic Resins, radical copolymers such as styrene-(anhydride) maleic acid resins and terpene-(anhydride) maleic acid resins, and acid-modified polyolefin resins can be used.
These may be used individually by 1 type, and may use 2 or more types together.

A low-molecular-weight compound having an acidic group refers to a compound having no molecular weight distribution and having a molecular weight of 1,000 or less. Examples of such compounds include saturated fatty acids such as lauric acid, myristic acid, palmitic acid, margaric acid, and stearic acid; hydroxy acids such as lactic acid, malic acid, and citric acid; aromatic carboxylic acids such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, and cinnamic acid; oxalic acid, Dicarboxylic acids such as malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid and maleic acid; tricarboxylic acids such as aconitic acid; oxocarboxylic acids such as pyruvic acid and oxaloacetic acid; carboxylic acid derivatives such as amino acids and nitrocarboxylic acids and acid anhydrides such as trimellitic anhydride and pyromellitic anhydride.
A low-molecular-weight compound having an acidic group can be used in combination with a resin having an acidic group or a known binder resin constituting a known primer layer to form a primer layer.

From the viewpoint of suitability for recoating, the primer layer preferably contains a compound having an acidic group. In addition, from the viewpoint of printability, it is preferable to include a urethane resin having an acidic group, an acrylic resin having an acidic group, and a rosin-modified resin.

[Urethane resin having an acidic group]
The urethane resin having an acidic group is not particularly limited, and for example, a urethane resin obtained by reacting a polyol having an acidic group with a polyisocyanate, or a urethane resin obtained by reacting a polyol with a polyisocyanate, the hydroxyl groups in the urethane resin are acid-modified. and a resin obtained by acid-modifying the amino group in a urethane urea resin obtained by reacting an isocyanate group in a urethane resin obtained by reacting a polyol and a polyisocyanate with a polyamine.
As the urethane resin having an acidic group, a resin obtained by reacting a polyol containing a hydroxy acid and a polyisocyanate may be used. By using a hydroxy acid as a polyol, an acid value derived from a carboxy group can be imparted to the urethane resin, and the releasability can be improved. Further, when the urethane resin having an acidic group has an isocyanate group, a part of the isocyanate group may be reacted with a polyamine to introduce a urea bond to form a urethane urea.

《Polyol》
Polyol is a general term for compounds having at least two hydroxyl groups in one molecule. The number average molecular weight of the polyol is preferably 500-10,000, more preferably 1,000-5,000. The number average molecular weight is calculated from the hydroxyl value of the polyol, and the hydroxyl value refers to the value measured according to JIS K 0070. When the number average molecular weight of the polyol is 500 or more, the flexibility of the primer layer is excellent and the adhesion to the plastic substrate is improved. When the number average molecular weight is 10,000 or less, the anti-blocking property for plastic substrates is excellent.

The polyol is not particularly limited, and more preferably at least one polyol selected from the group consisting of polyester polyols, polyether polyols and polycarbonate polyols. Furthermore, the polyol may also include other dimer diols, hydrogenated dimer diols, castor oil-modified polyols, and the like.
That is, the urethane resin preferably contains at least one polyol-derived structural unit selected from the group consisting of polyester polyols, polyether polyols, and polycarbonate polyols. More preferably, it contains a structural unit derived from a polyester polyol, since alkali hydrolysis of the ester bond site of the polyester polyol improves the releasability.
The content of polyol-derived structural units is preferably 10 to 75% by mass, more preferably 15 to 70% by mass, and still more preferably 20 to 65% by mass, based on the total amount of the urethane resin. The content of polyester polyol-derived structural units is preferably 5% by mass or more, more preferably 30% by mass or more, still more preferably 60% by mass or more, and particularly preferably 80% by mass, based on the total amount of polyol-derived structural units. That's it.

《Hydroxy acid》
The polyols may contain hydroxy acids. The hydroxy acid refers to a compound having both a hydroxyl group, which is an active hydrogen group, and an acidic functional group in one molecule. The acidic functional group refers to a functional group that can be neutralized with potassium hydroxide when measuring the acid value, and specifically includes a carboxy group, a sulfonic acid group, and the like, preferably a carboxy group. As such hydroxy acids, dimethylolalkanoic acids such as 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2-dimethylolvaleric acid are preferably used.

《Polyisocyanate》
The polyisocyanate is not particularly limited and can be selected from conventionally known polyisocyanates. Preferably, it contains diisocyanates or triisocyanates, more preferably aromatic, aliphatic or cycloaliphatic diisocyanates. These may be used alone or in combination of two or more.

《Polyamine》
Polyamines for forming urethane urea are not particularly limited, and diamine compounds are preferred. In addition, a diamine having a hydroxyl group may be used in that a hydroxyl group can be introduced into the urethane resin.

The acid value of the urethane resin having acidic groups is preferably 15 mgKOH/g or more, more preferably 15 to 70 mgKOH/g, still more preferably 20 to 50 mgKOH/g. When it is 15 mgKOH/g or more, the detachability with a desorbing liquid is favorable, and when it is 70 mgKOH/g or less, it is preferable because substrate adhesion and retort resistance are improved. The hydroxyl value of the urethane resin is preferably 1-35 mgKOH/g, more preferably 10-30 mgKOH/g. When it is 1 mgKOH/g or more, it is preferable because the detachability by the detachment liquid is improved, and when it is 35 mgKOH/g or less, it is preferable because the adhesion to the substrate is improved.

The urethane resin having an acidic group preferably has a weight average molecular weight of 10,000 to 100,000, more preferably 15,000 to 70,000, still more preferably 15,000 to 50,000. The molecular weight distribution (Mw/Mn) of the urethane resin is preferably 6 or less. Mw represents the weight average molecular weight and Mn represents the number average molecular weight. When the molecular weight distribution is 6 or less, the releasability, the drying property of the primer composition, and the suitability for retort resistance are excellent. Further, the smaller the molecular weight distribution, that is, the sharper the molecular weight distribution, the more uniformly the dissolution and peeling action by the desorption liquid occurs, and the detachability of the plastic substrate is improved. The molecular weight distribution is more preferably 5 or less, still more preferably 4 or less. Also, the molecular weight distribution is preferably 1.5 or more, more preferably 1.2 or more.
In the present specification, Mw, Mn and molecular weight distribution (Mw/Mn) are polystyrene equivalent values determined by gel permeation chromatography (GPC).

A urethane resin having an acidic group may have an amine value. When the urethane resin has an amine value, the amine value is preferably 0.1 to 20 mgKOH/g, more preferably 1 to 10 mgKOH/g. Within the above range, the adhesiveness to the substrate is excellent.

The number of urethane bonds in the polyurethane resin having an acidic group is preferably 1-3 mmol/g, more preferably 1.5-2 mmol/g. Also, the number of urea bonds is preferably 0 to 3 mmol/g, more preferably 0.2 to 1 mmol/g. Also, the total number of urethane bonds and urea bonds is preferably 1 to 6 mmol/g, more preferably 1.7 to 3 mmol/g.
By setting the number of urethane bonds and the number of urea bonds within the relevant ranges, the releasability and substrate adhesion are improved.

[Acrylic resin having an acidic group]
The acrylic resin having an acidic group includes, for example, a polymer obtained by polymerizing a monomer containing a (meth)acrylic monomer having an acidic group such as (meth)acrylic acid and maleic acid; a (meth)acrylic monomer having a hydroxyl group or a glycidyl group. After polymerizing a monomer containing, the functional group is modified to introduce a carboxyl group (for example, a maleic anhydride-modified resin);
The acid value of the acrylic resin having acidic groups is preferably 50 mgKOH/g or more, more preferably 100 mgKOH/g or more.

[Rosin modified resin]
A rosin-modified resin is a resin prepared using rosin as one of raw materials. Rosin contains a mixture of resin acids such as abietic acid, parastric acid, isopimaric acid, levopimaric acid, etc. These resin acids contain hydrophilic and chemically active carboxyl groups, some of which have conjugated double bonds. Some are prepared. Therefore, polyhydric alcohols and polybasic acids are combined for condensation polymerization, phenolic condensate resol is added to the benzene ring contained in the rosin skeleton, and dienophile maleic anhydride and maleic acid undergo Diels-Alder reaction. Various rosin-modified resins have been prepared by adding a maleic acid or maleic anhydride skeleton by allowing the Various types of such rosin-modified resins are commercially available, and it is also possible to obtain and use them.

Examples of rosin-modified resins include maleated rosin, fumarated rosin, rosin-modified maleic acid resin, rosin-modified fumaric acid resin, rosin-modified phenolic resin, rosin-modified alkyd resin, and rosin-modified polyester resin. In the present invention, any rosin-modified resin may be used, but among these, at least one selected from the group consisting of maleic acid, maleic anhydride, fumaric acid and fumaric anhydride in its structure Those containing a portion to be used are preferably used. A resin that "contains a site derived from at least one selected from the group consisting of maleic acid, maleic anhydride, fumaric acid and fumaric anhydride in its structure" means maleic acid and maleic anhydride as part of raw materials. It is prepared using at least one selected from the group consisting of acid, fumaric acid and fumaric anhydride, for example, rosin-modified malein obtained by condensation polymerization of maleic acid or fumaric acid as part of the polybasic acid Acid resins, rosin-modified fumaric acid resins, maleic rosins and fumaric rosins having a structure obtained by adding maleic acid, maleic anhydride, fumaric acid, or fumaric anhydride as a dienophile by Diels-Alder reaction, fumaric rosins, and functional groups contained therein It means a resin or the like obtained by further polymerizing another chemical species using a group.

The acid value of the rosin-modified resin is preferably 10-400 mgKOH/g, more preferably 100-300 mgKOH/g.

(Other ingredients)
The primer layer may contain a resin other than a water-soluble resin or a compound having an acidic group.
Examples of such resins include cellulose resins, polyamide resins, vinyl chloride resins such as vinyl chloride-vinyl acetate copolymer resins or vinyl chloride-acrylic copolymer resins, ethylene-vinyl acetate copolymer resins, and vinyl acetate resins. , acrylic resin, styrene resin, dammar resin, styrene-acrylic copolymer resin, polyester resin, alkyd resin, terpene resin, phenol-modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, polyacetal resin, petroleum resin, and These modified resins can be mentioned. These resins may be used individually by 1 type, and may use 2 or more types together.
Among them, the primer layer preferably contains at least one resin selected from the group consisting of cellulose resins, vinyl chloride resins, rosin resins, and acrylic resins. More preferably, vinyl chloride resin or acrylic resin is included.
The mass ratio of the urethane resin having an acidic group to the other resin (urethane resin having an acidic group:other resin) is preferably 95:5 to 50:50. Within the above range, when the printed layer is peeled off together with the primer layer in a basic aqueous solution, the printed layer is peeled off in the form of a thin film, which facilitates recovery, which is preferable.

The primer layer may contain an extender. Examples of extender pigments include metal oxides such as silica, barium sulfate, kaolin, clay, calcium carbonate, magnesium carbonate, zinc oxide and zirconium oxide. Among them, silica is preferred, and hydrophilic silica is more preferred.
The average particle size of the extender is preferably 0.5-10 μm, more preferably 1-8 μm. The content of the extender pigment in the primer layer is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass. When the average particle size and the content of the extender are within the above ranges, the wettability of the printed layer is improved and the image quality is improved.

The primer layer may be a layer in which the above-described urethane resin having an acidic group is crosslinked with a curing agent. By introducing a crosslinked structure into the primer layer, it is possible to suppress permeation and bleeding of the print layer formed on the primer layer, thereby exhibiting excellent image quality.
Curing agents include, for example, polyisocyanates. The polyisocyanate is not particularly limited and can be selected from conventionally known polyisocyanates, such as aliphatic polyisocyanates and araliphatic polyisocyanates. These may be used alone or in combination of two or more.

The primer layer may further contain known additives. Known additives include, for example, dispersants, wetting agents, adhesion aids, leveling agents, antifoaming agents, antistatic agents, viscosity modifiers, metal chelates, trapping agents, antiblocking agents, wax components other than the above, A silane coupling agent is mentioned.

The thickness of the primer layer is preferably 0.5 to 3.0 μm, more preferably 0.6 to 2.0 μm, still more preferably 0.8 to 1.5 μm, and is formed by a known method. be able to.

[Adhesive layer]
The laminate of the present invention may have an adhesive layer. When the laminate has an adhesive layer, the adhesive layer is disposed in contact with the plastic substrate and contains a compound having an acidic group, It preferably plays a role of detaching the plastic base material by dissolution, detachment, or the like with a detaching liquid. Since the adhesive layer contains a resin having an acidic group or a low-molecular-weight compound having an acidic group, the adhesive layer can be removed using the basic aqueous solution described above.
For the compound having an acidic group, the resin having an acidic group, and the low-molecular-weight compound having an acidic group, the description of (compound having an acidic group) in the section [Primer layer] described above can be used.
Moreover, the method for forming the adhesive layer is not limited, and it can be formed using a known method.

The adhesive layer is a cured product of an adhesive containing a polyester polyol having an acidic group and at least one polyisocyanate selected from the group consisting of aliphatic polyisocyanates and araliphatic polyisocyanates, from the viewpoint of releasability. may be The cured product corresponds to a resin having an acidic group.
Further, the adhesive layer is a cured product of an adhesive containing polyester polyol, at least one polyisocyanate selected from the group consisting of aliphatic polyisocyanate and araliphatic polyisocyanate, and a low-molecular-weight compound having an acidic group. may be

<Plastic substrate layer>
Examples of plastic substrates include polyolefin resins, polyester resins, polyamide resins, polystyrene resins, vinyl chloride resins, vinyl acetate resins, ABS resins, acrylic resins, acetal resins, polycarbonate resins, polyvinyl alcohol resins, and cellulose plastics. be done.

From the viewpoint of reuse as a recycled base material, the plastic base material is preferably a polyolefin base material containing a polyolefin resin. Examples of base materials containing such polyolefin resins include plastic base materials such as polyethylene (PE) and biaxially oriented polypropylene (OPP), as well as low density polyethylene (LDPE) and linear low density polyethylene (LLDPE). ), high-density polyethylene (HDPE), acid-modified polyethylene, unoriented polypropylene (CPP), acid-modified polypropylene, copolymerized polypropylene.

The thickness of the plastic substrate layer is not particularly limited, and may be appropriately selected according to the application. It is preferably 5 to 200 μm, more preferably 10 to 150 μm. Examples of gas barrier substrates include aluminum foil, vapor deposited layers of metal such as aluminum, and vapor deposited layers of metal oxides such as silica and alumina. The thickness of the aluminum foil is often used in the range of 3 to 50 μm from an economical point of view. In addition, since the aluminum foil, the aluminum vapor deposition layer and the alumina vapor deposition layer are dissolved in the basic aqueous solution and desorbed, they function as a desorption layer and can separate the adjacent polyolefin resin.

Examples of the laminate structure of the present invention are shown below, but the present invention is not limited thereto. In addition, in the following configuration, the "base material layer" does not have to be a single layer, and may be a laminate in which a plurality of base materials are laminated.
・Plastic base layer/printing layer ・Plastic base layer/primer layer/printing layer ・Plastic base layer/printing layer/adhesive layer/plastic base layer ・Plastic base layer/primer layer/printing layer/adhesive Layer/Plastic base layer/Base layer/Printing layer/Adhesive layer/Plastic base layer/Plastic base layer/Primer layer/Printing layer/Adhesive layer/Vapor deposition layer/Plastic base layer

<Method for manufacturing molding material>
A molding material can be produced by melt-kneading the plastic base material recovered by the separation and recovery method described above. The method for producing the molding material of the present invention preferably includes steps 1 to 3 below. When the molding material contains a masterbatch, the following step 4 may be further included.
(Step 1) A step of crushing the laminate and immersing it in a detachment liquid to detach the plastic substrate from the laminate (Step 2) A step of washing the plastic substrate obtained in Step 1 with water ( Step 3) Step of melt-kneading the plastic base material obtained in step 2 to obtain a recycled resin (step 4) Step of mixing the masterbatch with the recycled resin obtained in step 3

The method of crushing the packaging material in step 1 is not particularly limited, and examples thereof include methods using a jaw crusher, impact crusher, cutter mill, stamp mill, ring mill, roller mill, jet mill, and hammer mill.
Step 2 may further include a drying step as needed. Through step 2, a recycled base material (also referred to as a recycled plastic base material) can be obtained.

In the melt-kneading step in step 3, various additives are added as necessary, and after mixing with a Henschel mixer, tumbler, disper, etc., a kneader, roll mill, super mixer, Henschel mixer, Shugi mixer, vertical granulator, high Speed mixer, fur matrix, ball mill, steel mill, sand mill, vibration mill, attritor, batch kneader such as Banbury mixer, twin screw extruder, single screw extruder, rotor type twin screw kneader, etc. Refers to mixing or dispersing. As a result, a recycled resin, which is a resin composition, is obtained. The shape of the recycled resin is not particularly limited, and may be in the form of pellets, powder, granules, or beads. The melt-kneading step preferably uses a twin-screw extruder.

[Master Badge]
The molding material of the present invention can further contain a masterbatch. The masterbatch is not particularly limited as long as it is compatible with the recycled resin, and generally a mixture of a thermoplastic resin such as polyethylene resin or polypropylene resin and a colorant kneaded can be used. The thermoplastic resin contained in the masterbatch may be used alone or in combination of two or more.
The masterbatch in the present invention may contain alkali metal, alkaline earth metal or zinc metallic soap, hydrotalcite, nonionic surfactant, cationic surfactant, anionic surfactant, as long as the effects of the present invention are not impaired. amphoteric surfactants, antistatic agents, flame retardants such as halogen-based, phosphorus-based or metal oxides, lubricants such as ethylenebisalkylamide, antioxidants, ultraviolet absorbers and fillers.

<Molded body>
A molded article can be obtained by heat-molding the molding material obtained by the manufacturing method described above. The thermoforming method is not particularly limited, and examples thereof include injection molding, extrusion molding, blow molding, and compression molding.
The molding material produced using the plastic base material recovered by the separation and recovery method of the present invention is of high quality because the printed layer is detached and reattachment of the detached component is suppressed. It can be used in various fields such as products, stationery, parts for automobiles, toys and sporting goods, materials for medical use, and building and construction materials.

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

<Molecular weight and molecular weight distribution>
Weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) were measured by GPC (gel permeation chromatography), and were obtained as converted molecular weights using polystyrene as a standard substance. Measurement conditions are shown below.
GPC device: Showa Denko Shodex GPC-104
Column: The following columns were connected in series and used.
Showa Denko Shodex LF-404 2 Showa Denko Shodex LF-G
Detector: RI (differential refractometer)
Measurement conditions: Column temperature 40°C
Eluent: Tetrahydrofuran Flow rate: 0.3 mL/min

<Acid value, hydroxyl value>
Acid value and hydroxyl value were measured according to the method described in JIS K 0070 (1992).

<Production of primer composition and printing ink resin>
[Synthesis Example 1-1] (Polyurethane resin P1)
While introducing nitrogen gas in a reactor equipped with a reflux condenser, a dropping funnel, a gas inlet tube, a stirrer, and a thermometer, PPA (consisting of a polycondensate of propylene glycol and adipic acid, having a number average molecular weight of 2, 000 polyester polyol) 152.2 parts, PPG (a polyether polyol having a number average molecular weight of 2,000 consisting of polypropylene glycol) 15.2 parts, BD (1,4-butanediol) 13.6 parts, IPDI (isophorone 99.8 parts of diisocyanate) and 200 parts of NPAC (n-propyl acetate) were charged and reacted at 90° C. for 5 hours to obtain a urethane prepolymer solution having terminal isocyanate groups.
Then, a mixture of 19.2 parts of AEA (2-(2-aminoethylamino) ethanol) and 350 parts of IPA (isopropyl alcohol) was added dropwise over 60 minutes at room temperature, followed by reaction at 70° C. for 3 hours. to obtain a polyurethane resin solution.
NPAC was added to the obtained polyurethane resin solution to adjust the solid content, resulting in polyurethane resin P1 having a solid content concentration of 30%, a weight average molecular weight of 27,000, Mw/Mn = 3.1, and an acid value of 0.0 mgKOH/g. A solution of

[Synthesis Example 1-2] (Polyurethane Resin P2)
135.7 parts of PPA, 13.6 parts of PPG, DMPA (2,2 -dimethylolpropanoic acid), 105.7 parts of IPDI, and 200 parts of NPAC were charged and reacted at 90°C for 5 hours to obtain a urethane prepolymer solution having terminal isocyanate groups.
Then, a mixture of 16.7 parts of AEA and 350 parts of IPA was added dropwise at room temperature over 60 minutes, followed by reaction at 70° C. for 3 hours to obtain a polyurethane resin solution.
NPAC was added to the obtained polyurethane resin solution to adjust the solid content, resulting in a polyurethane resin P2 having a solid content concentration of 30%, a weight average molecular weight of 30,000, Mw/Mn = 3.0, and an acid value of 39.3 mgKOH/g. A solution of

<Production of composition for forming primer layer>
[Production Example 1-1] (Primer Composition S1)
87 parts of the polyurethane resin P2 solution, 5 parts of EA, 5 parts of IPA, and 3 parts of silica particles (P-73 manufactured by Mizusawa Chemical Co., Ltd.: hydrophilic silica particles having an average particle diameter of 3.8 μm) are stirred and mixed using a disper to form a primer. A composition S1 was obtained.

<Production of printing ink>
[Production Example 2-1] (Printing ink R1)
Indigo pigment P. B. 15 (CI Pigment Blue 15) 10 parts, polyurethane resin P1 solution 25 parts, PVC solution (vinyl chloride-vinyl acetate copolymer resin solution (manufactured by Nissin Kagaku Solbin TAO, solid content 30%, EA solution) ), 10 parts of EA, and 10 parts of IPA were mixed and stirred, and dispersed for 20 minutes using a sand mill as a bead mill. Thereafter, 20 parts of the polyurethane resin P1 solution, 10 parts of EA, and 10 parts of IPA were mixed and stirred to obtain printing ink R1. Table 1 shows the total blending amount of the blending at the time of dispersion and the post-blending.

[Production Examples 2-2 to 6] (Printing Inks R2 to 6)
Printing inks R2 to R6 were obtained in the same manner as in Ink Production Example 2-1, except that the raw materials and blending ratios shown in Table 1 were used. The blending amount in Table 1 is the sum of the blending at the time of dispersion and the post-blending. The blending amount at the time of dispersion was adjusted so that the resin solution at the time of post blending would be 20 parts.

Abbreviations in Table 1 are shown below.
P. B. 15: C.I. I. Pigment Blue 15
Synergist 2100: Pigment derivative, BYK-SYNERGIST 2100 manufactured by BYK-Chemie Japan
BYK-142: Resin type dispersant, DISPERBYK-142 manufactured by BYK-Chemie Japan
PVC solution: vinyl chloride-vinyl acetate copolymer resin solution, Solbin TAO manufactured by Nissin Chemical Co., Ltd. (30% solid content, EA solution)
EA: ethyl acetate IPA: isopropyl alcohol

<Production of polyol used for adhesive>
[Synthesis Example 2-1] (polyester polyol B1)
124 parts of ethylene glycol, 212 parts of neopentyl glycol, 368 parts of 1,6-hexanediol, 645 parts of isophthalic acid and adipine were placed in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping tank and nitrogen gas inlet tube. 36 parts of acid and 265 parts of sebacic acid were charged, and the temperature was raised to 250° C. while stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value became 5 or less, the pressure was gradually reduced, and the deglycol reaction was performed at 1 mmHg or less for 5 hours to obtain a polyester polyol. After that, 35 parts of isophorone diisocyanate was gradually added and reacted at 150° C. for about 2 hours to obtain a polyester polyurethane polyol. 12.0 parts of ethylene glycol bis-anhydrotrimellitate was added to 100 parts of this polyester polyurethane polyol, reacted at 180° C. for about 2 hours, and then diluted with ethyl acetate until the solid content concentration reached 50%. A solution of partially acid-modified polyester polyol B1 having an average molecular weight of 9,000 and an acid value of 30.3 mgKOH/g was obtained.

[Synthesis Example 2-2] (polyester polyol B2)
58 parts of ethylene glycol, 412 parts of diethylene glycol, 343 parts of neopentyl glycol, 517 parts of isophthalic acid, and 393 parts of adipic acid are charged into a reaction vessel equipped with a stirrer, thermometer, reflux condenser, dropping tank and nitrogen gas inlet tube. , the temperature was raised to 250° C. with stirring under a nitrogen stream to carry out an esterification reaction. After a predetermined amount of water was distilled and the reaction was continued until the acid value became 5 or less, the pressure was gradually reduced, and the deglycol reaction was performed at 1 mmHg or less for 5 hours to obtain a polyester polyol. 4.0 parts of trimellitic anhydride was added to 100 parts of this polyester polyol, reacted at 180° C. for about 2 hours, and then diluted with ethyl acetate to a solid content concentration of 50%, resulting in a number average molecular weight of 2,000. , and an acid value of 23.5 mg KOH/g to obtain a solution of partially acid-modified polyester polyol B2.

<Adjustment of polyisocyanate>
[Preparation Example 1] (Polyisocyanate C1)
Coronate 2785 (biuret-type polyisocyanate derived from hexamethylene diisocyanate, manufactured by Tosoh Corporation) was diluted with ethyl acetate to adjust the solid content concentration to 50% and NCO% = 9.6%, and a solution of polyisocyanate C1 was prepared. Obtained.

<Manufacture of adhesive>
[Production Example 3-1] (Adhesive D1)
90 parts of the polyester polyol B1 solution, 10 parts of the polyester polyol B2 solution and 8 parts of the polyisocyanate C1 solution were blended, and EA was added to prepare an adhesive solution having a solid concentration of 30%.

<Production of laminate>
A method for manufacturing a laminate will be described below. In addition, the primer composition and the printing ink were each prepared using a mixed solvent of EA/IPA (mass ratio: 70/30) so that the viscosity would be 15 seconds (25°C, Zahn Cup #3 (manufactured by Rigosha)). was used after diluting to Also, the thickness of the primer layer and the printed layer were each adjusted to be about 1.5 μm.

[Production Example 4-1] (Laminate L1)
The diluted primer composition S1 and printing ink R1 were printed in this order on OPP (corona-treated oriented polypropylene film, thickness 20 μm) using a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, and printed at 50° C. After drying, a laminate having a configuration of OPP/S1/R1 was obtained.
Next, on the printed layer of the obtained laminate, an adhesive D1 was applied using a dry laminator so that the film thickness after drying was about 3 μm, dried, and then CPP (unstretched polypropylene film thickness 50 μm). By lamination, a laminate L1 having a structure of base layer (OPP)/primer layer (S1)/printing layer (R1)/adhesive layer (D1)/base layer (CPP) was obtained.

[Production Examples 4-2 to 5] (Laminates L2 to 5)
Laminates L2 to L5 were obtained in the same manner as in Production Example 4-1, except that the printing ink was changed as shown in Table 2.

[Production Example 4-6] (Laminate L6)
The diluted primer composition S1 and printing ink R3 are printed on OPP in this order using a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, dried at 50 ° C., and a base layer (OPP) A laminate L6 having a structure of /primer layer (S1)/printing layer (R3) was obtained.

[Production Example 4-7] (Laminate L7)
A diluted printing ink R3 is printed on OPP using a gravure printing machine equipped with a gravure plate with a plate depth of 30 μm, and dried at 50 ° C. to form a substrate layer (OPP)/printing layer (R3) structure. A laminate L7 was obtained.

[Production Example 4-8] (Laminate L8)
A laminate L8 was obtained in the same manner as in Production Example 4-7, except that the printing ink was changed as shown in Table 2.

Abbreviations in Table 2 are shown below.
OPP: corona-treated oriented polypropylene film, thickness 20 μm
CPP: unstretched polypropylene film, thickness 50 μm

<Production of desorbed liquid>
[Production Example 5-1] (Elimination liquid A1)
2 parts of sodium hydroxide and 98 parts of water were blended and stirred with a disper to obtain a stripped liquid A1.

[Production Examples 5-2 to 4] (Elimination liquids A2 to 4)
In addition to sodium hydroxide and water, POE stearyl ether (POE addition number: 12, HLB: 13.9) as a surfactant, BYK-1650 as an antifoaming agent (manufactured by BYK-Chemie Japan, silicone emulsion type antifoaming agent, Solid content concentration 27.5%) was blended according to the blending composition shown in Table 3 to obtain stripped liquids A2 to 4 in the same manner as in Production Example 5-1.

<Separation and recovery of laminate>
[Example 1]
In a 1000 mL stainless steel beaker, 500 g of desorption liquid A3 and 20 g of a 1 cm×1 cm sample of laminate L4 were placed and stirred at 70° C. and 2000 rpm. The following evaluations were performed on the state of separation and collection of the laminate.

[Examples 2 to 13, Comparative Examples 1 to 4]
In addition, the separation and recovery state of the laminate was evaluated in the same manner as in Example 1, except that the materials, the amounts of the laminate and the printed layer with respect to the desorbing liquid, and the stirring speed were changed to the contents shown in Table 4. gone. In addition, 0.2 g of the laminate of Comparative Example 4 corresponds to 100 samples obtained by cutting the laminate L4 into a size of 1 cm×1 cm.
Table 4 shows the results. Regarding the amounts of the laminate, the printed layer, and the film with respect to the removing liquid, the density of the primer layer, the printed layer, and the adhesive layer was 1 g/cm ³ , and the density of the OPP base material and the CPP base material was 0.91 g/cm 3 . calculated as ³ .

<Evaluation of laminate>

(removable)
After 15 minutes, 30 minutes, and 1 hour from the start of stirring, the substrate was sampled, washed with water, and dried. Ten OPP substrates were sampled from the obtained substrates, and the removal rate of the printed layer was visually confirmed and evaluated according to the following criteria.
A (excellent): 90% or more of the printed layer was peeled off from the substrate after 15 minutes from the start of stirring.
B (good): 90% or more of the printed layer was peeled off from the substrate after 30 minutes from the start of stirring.
C (acceptable): 90% or more of the printed layer was peeled off from the base material after 1 hour from the start of stirring.
D (impossible): 90% or more of the printed layer was not peeled from the substrate after 1 hour from the start of stirring.

(Reattachment)
After 2 hours from the start of stirring, the detached base material was collected in a sieve with an opening of 1 mm, washed with water, and dried. 10 OPP substrates were sampled from the obtained substrates, and the 10 substrates were stacked and color values L ^* _x , a ^* _x , b were measured with a spectrophotometer (manufactured by X-rite, X-rite eXact). ^* _x was measured.
Similarly, for the OPP base material before printing, OPP (20 g) cut into a size of 1 cm × 1 cm is immersed in desorption liquid A3 (500 g), stirred at 70 ° C. and 2000 rpm for 2 hours, washed with water, and dried. , 10 sheets were sampled, 10 sheets of the base material were stacked, and the color values L ^* _y , a ^* _y , and b ^* _y were measured.
The color difference ΔE was determined by the following formula, and the reattachment property was evaluated according to the following criteria.
(Formula) ΔE=((L ^* _x −L ^* _y ) ² +(a ^* _x −a ^* _y ) ² +(b ^* _x −b ^* _y ) ² ) ^1/2
A (excellent): ΔE is less than 3 B (good): ΔE is 3 or more and less than 10 C (acceptable): ΔE is 10 or more and less than 20 D (improper): other than A to C

(Particle size of separated print layer component)
After stirring for 2 hours from the start of stirring, the detached base material was removed with a sieve with an opening of 1 mm, and the detached liquid in which the detached printing layer components were dispersed was recovered. The particle size distribution of the desorbed liquid was measured with a laser diffraction/scattering particle size distribution analyzer (Microtrac MT-3000EX (II) manufactured by Microtrac Bell). A 2% sodium hydroxide aqueous solution was used as a dispersion medium. From the obtained volume frequency particle size distribution curve, the 10 volume% diameter (D10), the median diameter (50 volume% diameter, D50), and the 90 volume% diameter (D90) are obtained, and the span value of the particle size distribution is obtained from the obtained values. A ((D90-D10)/D50) was determined.

(processing efficiency)
After 2 hours from the start of stirring, the desorbed OPP base material and CPP base material are collected, washed with water, and dried, then the weight of the collected base material is measured, the amount relative to the desorbed liquid charged is determined, and evaluated according to the following criteria. bottom.
A (excellent): The amount of recovered base material relative to the charged desorbed liquid is 3% or more B (Good): The amount of recovered base material relative to the charged desorbed liquid is 1% or more and less than 3% C (Fair): Recovery relative to the charged desorbed liquid The amount of base material is 0.1% or more and less than 1% D (impossible): The amount of recovered base material is less than 0.1% with respect to the charged and desorbed liquid

(Manufacture of recycled film and transmittance evaluation)
After 2 hours from the start of stirring, the detached OPP base material and CPP base material are collected, washed with water, and dried. A pellet was obtained. The recycled resin was extruded at 200° C. using a T-die film molding machine to produce a recycled film having a thickness of 50 μm.
Using a haze meter (manufactured by Nippon Denshi Kogyo Co., Ltd., SH7000), the haze of the recycled film was measured and evaluated according to the following criteria.
A (excellent): haze of 20% or less B (good): haze of 20% or more and less than 40% C (acceptable): haze of 40% or more and less than 60% D (improper): haze of 60% or more

From the above evaluation results, with the separation and recovery method of the present invention, the printed layer can be easily detached from the laminate even when the processing amount of the laminate is large, and the printed layer is less redeposited. It was shown that a recycled base material can be obtained, and furthermore, a high-quality molding material with little coloration can be obtained.

Claims (9)

A laminate comprising at least a plastic base layer and a printed layer is immersed in a desorption liquid, and the printed layer is removed from the plastic base layer so that the median diameter (D50) on a volume basis of the printed layer components is 1 μm or more. A method for separating and recovering a laminate, comprising a step of desorbing and recovering a plastic substrate,
The desorbed print layer component has a span value A represented by the following formula of 10 or less,
A = (D90-D10)/D50
D10: Cumulative 10% diameter of volume-based particle size distribution obtained by laser diffraction particle size distribution measurement of desorbed print layer components
D90: Cumulative 90% diameter of volume-based particle size distribution obtained by laser diffraction particle size distribution measurement of desorbed print layer components
A method for separating and recovering a laminate, wherein the printed layer accounts for 0.01% by mass or more of the total mass of the desorbing liquid. 2. Separation and recovery of the laminate according to claim 1 , wherein the detached liquid contains water and a surfactant, and the content of the surfactant is 0.001% by mass or more in the total mass of the detached liquid. Method. 3. The printing layer according to claim 1, wherein the printed layer contains a colorant, a binder resin, and a dispersant, and the content of the dispersant is 0.01% by mass or more relative to the total mass of the colorant. A method for separating and collecting a laminate. 4. The method for separating and recovering a laminate according to claim 3 , wherein the dispersant contains a pigment derivative and/or a resin type dispersant. 5. The method for separating and recovering a laminate according to claim 4 , wherein the dispersant contains a pigment derivative, and the content of the pigment derivative is 0.01 to 10% by mass with respect to the total mass of the colorant. 3. The method for separating and recovering a laminate according to claim 1 or 2 , wherein the laminate accounts for 1.5% by mass or more of the total mass of the desorbing liquid. 3. The method for separating and recovering a laminate according to claim 1 , wherein the stripping liquid is a basic aqueous solution, and the step of stripping the printed layer in the basic aqueous solution to recover the plastic base material is included. 3. A method for producing a molding material, comprising melt-kneading a plastic base material recovered by the method for separating and recovering a laminate according to claim 1 or 2 . A method for producing a molded article, which comprises thermoforming the molding material obtained by the production method according to claim 8 .