JPH05228936A - Treating method and regenerating method for coated plastic molded body - Google Patents

Abstract

PURPOSE:To regenerate a plastic molded body without separating and removing a film therefrom and manufacture an inexpensive regenerated plastic product of low pollution without damaging its surface appearance. CONSTITUTION:A plastic molded body with its surface coated partly or totally is brought into contact with hot water and/or water vapor of 100 deg.C or over without making the body into small pieces in the treatment method for a coated plastic molded body. The coated plastic molded body is also melt molded again in the regenerating method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a good method for reclaiming a coated plastic molding, and in particular, by making the coating film finer rather than actively separating and removing it from the plastic molding. The present invention relates to an inexpensive and low-pollution technique that does not deteriorate the physical properties of recycled products and does not impair the surface appearance.

[0002]

2. Description of the Related Art Conventionally, plastics have been burned in an incinerator after use or buried in soil together with other refuse. However, even if it was buried in the soil, it was not decomposed by microorganisms and remained as it was, and the amount thereof increased. In recent years, recycling of plastics has been called for in order to reuse the resources and to protect the global environment such as global warming due to an increase in carbon dioxide concentration, and this problem has become more important. However, in order to recycle and reuse used plastic, various difficult problems must be solved. One of the problems is that the plastic used as the final product may use a single component for its material, but the final product is often obtained by compounding different materials. If the composited final product is used as it is without separating the different materials after use, the original excellent physical properties of the respective plastic materials themselves are significantly impaired, and The product regenerated from the material does not have the required physical properties such as strength, and the design properties such as appearance are significantly impaired. For example, the final product obtained by coating plastic was crushed as it was after use, re-pelletized by an extruder, and re-molded by a molding machine, and the regenerated product obtained was formed on the surface of the plastic. The coating film is not finely dispersed and remains as it is in the recycled product, and this coating film prevents the kneading and integration in the recycled resin, significantly lowering the physical properties of the recycled product,
The surface appearance was also significantly reduced, and it was not possible to obtain a product that could be used as a practical product.

Therefore, as the technique for peeling and removing the coating film from the final product coated with plastic, the following various techniques can be considered, but there is a problem in practicality. As a method of removing the coating film from the coated plastic product, a method of melting the plastic in the extruder and filtering and separating the unmelted coating film with a screen such as a wire mesh is also considered. Clogging occurs, the extrusion pressure remarkably increases, the extrusion amount decreases, the production amount remarkably decreases, and the effect of removing the coating film is poor and a good recycled product cannot be obtained. In addition, it may be possible to equip an automated filter exchanger to cover the reduction in production efficiency due to blockage in the screen or to take a large filtration area, but none of these methods can satisfy the method. . In order to remove the coating from painted plastic products, a large amount of strong alkali is used to hydrolyze the coating,
A method that does not mix the coating film into the product is conceivable, but it requires a separate facility such as wastewater treatment, which results in higher treatment costs and is not a practical technique. In order to remove the coating film from the painted plastic product, it is considered that the method of swelling and peeling the coating film with an organic solvent is also effective, but it increases the cost and uses the organic solvent. There is also concern about secondary pollution caused by. Further, Japanese Patent Application Laid-Open No. 2-273207 proposes a method in which a coating film on a plastic surface is blasted using a soft abrasive, peeled off, and regenerated. However, this method not only lowers the treatment efficiency when the coating surface has a complicated shape, but also makes it difficult to completely remove the coating film. In addition, this technique is not suitable for continuously processing products having different shapes.

[0004]

It was an unsolved problem how the final product of the plastic molded product coated as described above can be recycled as a high-quality plastic molded product at low cost. .. The present invention relates to a good method for recycling a coated plastic molded product, which reduces the physical properties of a recycled product by making the coating film finer and degenerated rather than actively separating and removing the coating film from the plastic molded product. It aims to provide an inexpensive and low-pollution technology that does not impair the surface appearance.

[0005]

[Means for Solving the Problems]

[Summary of the Invention] The present inventors have conducted intensive studies in view of the above problems, and as a result, brought a plastic molded article having a coating film into contact with hot water and / or steam of 100 ° C. or higher,
If the resin components that form the coating film are decomposed to lose their properties as a coating film, it is possible to obtain a remolded product that retains good physical properties even if it is melt-molded again. The present invention has been completed based on the findings. That is, the method for treating a coated plastic molded article of the present invention is to treat a plastic molded article whose surface is partially or wholly coated with hot water and / or steam of 100 ° C. or higher without fragmentation or fragmentation. The feature is that they are brought into contact with each other. In addition, another method of reclaiming a coated plastic molded article according to the present invention is that a plastic molded article whose surface is partially or wholly coated is diced into small pieces or without crushing into pieces at a temperature of 100 ° C or higher. It is characterized in that after being brought into contact with water and / or steam, it is melt-molded again without being fragmented or fragmented, mixed with other optional components or not mixed.

[Detailed Description of the Invention] [I] Method for treating coated plastic molded article (1) Raw material (a) Painted plastic molded article Part of the surface used in the method for treating coated plastic molded article of the present invention Or, a plastic molded product that is entirely coated is a plastic product in which a part of the molded product base material is coated, regardless of whether it is an outer surface or an inner surface.
These are the products used for their original purpose, or
It means a product which is manufactured for the purpose of use but has become a defective product. The above-mentioned plastic products are thermoplastic resins such as injection molding, extrusion molding, blow molding, transfer molding, and various molding methods such as press molding, for automobile bumpers, wheel caps,
Automotive exterior parts such as side moldings, instrument panels, levers, interior parts such as linings, vacuum cleaners, washing machines, refrigerators, lighting fixtures, audio equipment and other electrical products, color boxes, storage cases, etc. It refers to a general product which is formed by coating at least a part of the outer surface or the inner surface of a molded body substrate molded into various shapes such as a product.

(B) Molded-material base material Specific examples of the molded-material base material made of the above thermoplastic resin include polyolefins typified by polyethylene and polypropylene, and thermoplastic polyester resins such as polyethylene terephthalate and polybutylene terephthalate.
Engineering resins such as polyamide, polycarbonate, polyphenylene ether, polyoxymethylene,
Examples include styrene resins such as acrylonitrile / styrene copolymers and acrylonitrile / styrene / butadiene copolymers, or those molded using a composite material (including alloy) of these resins. Among the molded body substrates made of these thermoplastic resins, polyethylene,
A polyolefin represented by polypropylene or the like or a composite material using the same, in which the polyolefin component is 3
0% by weight or more, engineering resin such as polyamide, polycarbonate, polyphenylene ether, polyoxymethylene or its composite material, styrene resin such as acrylonitrile / styrene copolymer, acrylonitrile / styrene / butadiene copolymer or the like Those molded using a composite material are preferable. Among these molded body substrates, components other than the above thermoplastic resins, for example, talc, glass fiber, titanium oxide, inorganic fillers such as carbon, natural rubber, ethylene / propylene copolymer rubber, styrene / butadiene rubber, acrylonitrile.・ Rubber components such as butadiene rubber, isoprene rubber, urethane rubber, hydrogenated products of styrene / diene block copolymers,
It may contain a compounding material such as an organic pigment such as quinacridone or ferrocyan blue.

(C) Coating As a paint used to form a coated plastic molded product by applying a coating to the above-mentioned molded product substrate, generally widely used organic solvent-based paint, water-soluble resin paint, water Examples thereof include dispersible resin paints and aqueous emulsion paints. Specific examples of these paints include paints in which the resin component of the paint is acrylic, epoxy, polyester, alkyd, etc., and the crosslinking component is urethane or melamine. Among these paints, it is preferable to use a paint in which the resin component is acrylic or polyester and the crosslinking component is melamine. These paints are generally used in an amount of 10% by weight or less, preferably 7% by weight or less, based on the molded body substrate. The surface modification method at the time of coating on the plastic molded body substrate may be primer coating, plasma treatment, or other techniques, and the difference between these surface modification methods is the regeneration treatment of the present invention. Will not be affected.

(2) Fragmentation treatment Fragmentation treatment Since the coated plastic molded body obtained by coating the molded body substrate is too large to handle as it is, it is difficult to subject it to hot water and / or steam treatment described later. Usually, the fragmentation process is performed in advance. Therefore, the shape of the plastic used as the molded body substrate is not particularly limited, but is generally 20 cm to 1 mm, preferably 5 cm to 1 mm, particularly preferably 2 cm to 1 mm by this fragmentation treatment.
It is preferable to use it after pulverizing or cutting it to a size of a certain degree. Even if the crushed or cut plastic contains fine particles of 1 mm or less, there is no particular problem in the subsequent processing.

(3) Hot water and / or steam treatment (a) Cleaning treatment When performing hot water and / or steam treatment, remove dirt such as sand, mud, oil, etc. adhering to the surface and metal other than the coating film. A hot water and / or steam treatment may be performed after separation by performing a washing treatment in advance.
Alternatively, in the steam treatment step, the hot water and / or steam treatment and the cleaning treatment can be separated at the same time by utilizing the difference in specific gravity between the two.

(B) Hot water and / or steam treatment The most important hot water and / or steam treatment in the method for treating a coated plastic molding of the present invention is to contact hot water and / or steam at 100 ° C or higher. Done by. <Hot water and / or steam> Hot water used in the above treatment,
As the steam or a mixture of hot water and steam, water heated to a temperature of 100 ° C. or higher under normal pressure or under pressure is used. The hot water, steam, or a mixture of hot water and steam may be used alone, or may be used by mixing or dissolving other additive components such as a compounding agent shown below. Compounding agent During the above contact treatment step, a small amount of heat stabilizer, for example, 2,6
-Ditertiary butyl-4-methylphenol, 3
1% or less by weight of a phenol-based or phosphorus-based antioxidant such as a metal salt of (3,5-ditertiarybutyl-4-hydroxyphenyl) -propionic acid, or a metal salt such as calcium stearate, especially 0.5% by weight
It is also possible to coexist at the following concentrations. In addition, a third addition for preventing adhesion by the coating resin component generated during the contact treatment step, for example, preventing the coating resin component from adhering to the inner wall of the apparatus, and preventing nodule formation by the coating resin component of the molded body substrate. You may add things. Specific examples of these third additives include:
Examples include oil-in-water emulsions of silicone oil, silane compounds such as silane coupling agents, various glycols, and various surfactants.

<Treatment Conditions> Contact Temperature The temperature at the time of the above-mentioned contact treatment is related to the thermal properties of the molded article base plastic and the coating resin, but is a temperature of 100 ° C. or higher, usually 100 to 300 ° C., preferably 105 to 105 ° C. 200
C., particularly preferably in the temperature range 115-175.degree. If the contact temperature is less than the above range, the treatment time becomes long and the treatment becomes incomplete, so that it must be avoided. Further, if the contact temperature exceeds the above range, further treatment effect cannot be expected, which is not preferable. Contact pressure Further , the pressure during the contact treatment is not particularly limited as long as it is equal to or higher than the pressure corresponding to the boiling point of water used for the treatment, but generally 1 to 1
00 kg / cm ² , preferably 1.2 to 20 kg / cm
² , particularly preferably 1.5 to 10 kg / cm ² . Contact time The time required for the above contact treatment also varies depending on the type of molded body substrate, the thickness of the coating film and the type of raw material, but is generally 0.
It is suitable for 5 minutes to 10 hours, preferably for 1 minute to 5 hours, particularly preferably for 1 minute to 3 hours. Contact atmosphere In the atmosphere of the contact treatment is not particularly limited,
It is preferable to suppress the existing amount of oxygen to such an extent that the deterioration of the substrate is not significantly caused.

<Treatment effect> The coating film of a plastic molded product is generally crosslinked and is difficult to melt. However, the contact treatment with hot water and / or steam accelerates the decomposition of the polymer constituting the coating film. It is possible to obtain a recycled molded product that retains good physical properties without deteriorating the physical properties even if the coating film components that have lost their properties as cross-linked polymers are mixed into the plastic molded product and melt-molded again. it can. The coated plastic molding used in the present invention or the fragmented product thereof has a coating film formed on the surface thereof, which is formed by hot water and / or
Alternatively, when contacting with steam, it is desirable to perform contact treatment with the surface exposed so that the hot water and / or steam can be contacted. Therefore, for example, by melting these coated plastic moldings or their small pieces,
When the coating film components are kneaded to be contained in the plastic molded body substrate, the coating film components, when brought into contact with hot water and / or steam to be described later, contain these hot water and / or steam. Since it is not sufficiently contact-treated with steam, its effect is significantly reduced in the present invention.

<Apparatus> As a processing device used in the hot water and / or steam treatment step in the method for treating a coated plastic molded article of the present invention, the plastic of the molded article base material and a treatment medium (water at 100 ° C. or higher, It is a device that can be brought into contact with water vapor or a mixture of water and water vapor, and both may be brought into contact in a stationary state, but it is desirable that they are devices that can be moved relatively by stirring or the like. .. Specifically, there can be mentioned an apparatus and the like that can be achieved by using the following apparatuses singly or in combination of two or more. Equipment with mechanical stirrer such as vertical type and horizontal type. Not only a tank equipped with a stirrer, but also an extruder, a kneader, and the like are included. An apparatus capable of causing a flow by a treatment medium (hot water, or steam, or a mixture of hot water and steam) and other third substance without relying on mechanical stirring. For example, fluidized bed, spouted bed, etc. A device that can move a substrate by applying vibration or rotation to the device from the outside. The base material is a fixed bed, but a fixed bed reactor in which a treatment medium (hot water, steam, or a mixture of hot water and steam) moves. An apparatus for directly spraying a treatment medium (hot water, steam, or a mixture of hot water and steam) onto a molded product or a processing base material. An apparatus in which a substrate is passed through a chamber in which a treatment medium (hot water, steam, or a mixture of hot water and steam) is present. The contact treatment by the above-mentioned devices can be applied either continuously or batchwise.

(C) Dehydration / Drying The molded body substrate after the hot water and / or steam treatment is
If water adheres to the surface, it is subjected to a drying process, but it is usually the case that only dehydration is sufficient. Although the degree of dehydration / drying varies depending on the content of the next step, dehydration by a centrifuge or the like or drying by hot air may be performed. Further, such dehydration / drying can be carried out at the same time when repelletizing is carried out by an extruder having a dehydrating function. Such dehydration / drying is generally carried out until the water content in the molded base material becomes 1% by weight or less.

[II] Regeneration of plastic molded product (1) Small piece processing The molded material base material subjected to the hot water treatment is made into small pieces suitable for the subsequent molding step. In the process of "treatment", when the fragmentation process is not performed and the fragment is sized into a target size, this process can be omitted. (2) Composition The above-mentioned hot water-treated molded body substrate is pelletized again in the extruder and recycled, but at this time, unused plastic and other additional components can be mixed and used. .. The unused plastic may be the same plastic as the treated plastic or different plastics.
Moreover, the following can be mentioned as an example of other additional components. That is, antioxidants such as hindered phenol-based, sulfur-based, phosphorus-based, hindered amine-based, triazole-based, benzophenone-based, benzoate-based, nickel-based, salicylic acid-based light stabilizers, antistatic agents, lubricants, and peroxides. , Metal deactivators, organic and inorganic nucleating agents, neutralizing agents, antacids, antibacterial agents, optical brighteners, fillers, flame retardant aids and the like.

As the hindered phenol type antioxidant, 3,5-di-t-butyl-4-hydroxy-toluene and n-octadecyl-β- (4'-hydroxy-3) are used.
′, 5′-di-t-butylphenyl) propionate,
Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6'-tris (3,5- Di-t-butyl-4-hydroxybenzyl)
Benzene, calcium (3,5-di-t-butyl-4-
Hydroxy-benzyl-monoethyl-phosphate), triethylene glycol-bis [3- (3-t-
Butyl-5-methyl-4-hydroxyphenyl) propionate], 3,9-bis [1,1-dimethyl-2-
{Β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,
10-tetraoxaspiro [5,5] undecane, bis [3,3-bis [4'hydroxy-3'-t-butylphenyl) butyric acid] glycol ester, tocopherol,
2,2'-ethylidene bis (4,6-di-t-butylphenol), N, N'-bis [3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionyl] hydrazine, 2,2′-oxamidobis [ethyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate], 1,1,3-tris (2-methyl-
4-hydroxy-5-t-butylphenyl) butane,
1,3,5-Tris (3 ', 5'-di-t-butyl-4
'-Hydroxybenzyl) -S-triazine-2,4
6 (1H, 3H, 5H) -trione, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 3,5-di-t-butyl-4 -Hydroxyhydrocinnamic acid triester with-1,3,5-tris (2-hydroxyethyl) -S-triazine-2,4,6 (1H, 3H, 5
H) etc. can be mentioned.

As the sulfur type antioxidant, dilauryl-
3,3′-thiodipropionic acid ester, dimyristyl-3,3′-thiodipropionic acid ester, distearyl-3,3′-thiodipropionic acid ester, laurylstearyl-3,3′-thiodipropionic acid ester,
Examples thereof include dioctadecyl sulfide and pentaerythritol-tetra (β-lauryl-thiopropionate) ester.

As the phosphorus-based antioxidant, tris (mixed, mono- and dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 4,4'-butylidene-bis ( 3-methyl-6-t
-Butylphenyl-di-tridecyl) phosphite,
1,1,3-Tris (2-methyl-4-di-tridecylphosphite-5-t-butylphenyl) butane, bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphite , Tetrakis (2,4-di-t-butylphenyl) -4,4'-biphenylene phosphonite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2'-ethylidene-bis (4,6-di-t-
Butylphenyl) fluorophosphite, methylene-
Bis (4,6-di-t-butylphenyl) -2-ethylhexyl-phosphite, bis (2,4,6-di-t
-Butylphenyl) pentaerythritol-di-phosphite, triphenylphosphite, diphenyldecylphosphite, didecylphenylphosphite, tridecylphosphite, trioctylphosphite, tridodecylphosphite, trioctadecylphosphite, trinonyl Examples thereof include phenyl phosphite and tridodecyl trithiophosphite.

As the hindered amine-based light stabilizer, a polycondensate of dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, poly [[6- (1,1,3,3-Tetrabutyl) imino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [( 2,2,6,6-Tetramethyl-4-piperidyl) imino]], 2- (3,5
-Di-t-butyl-4-hydroxybenzyl) -2-n
-Bis (1,2,2,6,6-pentamethyl-4-piperidyl) ester of butylmalonic acid, tetrakis (2,2)
2,6,6-tetramethyl-4-piperidyl) -1,
2,3,4-butane tetracarboxylate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, N, N'-bis (2,2,6,6-tetramethyl-4- Piperidyl) hexamethylenediamine and 1,
Polycondensate with 2-dibromoethane, poly [(N, N'-
Bis (2,2,6,6-tetramethyl-4-piperidyl) hexamethylenediamine)-(4-morpholino-
1,3,5-triazine 2,6-diyl)], 1,1 '
-(1,2-ethanediyl) -bis (3,3,5,5-
Tetramethylpiperazinone), Tris (2,2,6,6)
-Tetramethyl-4-piperidyl) -dodecyl-1,
2,3,4-butanetetracarboxylate, tris (1,2,2,6,6-pentamethyl-4-piperidyl) -dodecyl-1,2,3,4-butanetetracarboxylate, bis (1,2) , 2,6,6-Pentamethyl-4-piperidyl) sebacate, 1,6,11-tris [{4,6-bis (N-butyl-N- (1,2,2,
6,6-Pentamethylpiperidin-4-yl) amino)
-1,3,5-Triazin-2-yl} amino] undecane, 1- [2- [3- (3,5-di-t-butyl-4]
-Hydroxyphenyl) propionyloxy] ethyl]
-4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-
Tetramethylpiperidine, 8-benzyl-7,7,9,
9-Tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-
Benzoyloxy-2,2,6,6-tetramethylpiperidine, N, N'-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,
2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like can be mentioned.

Examples of light stabilizers such as triazole-based, benzophenone-based, benzoate-based, nickel-based, salicylic acid-based light stabilizers are 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, p. -T-butylphenyl salicylate, 2,
4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2-
(2'-hydroxy-3 ', 5'-di-t-amyl-phenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole , 2- (2'-hydroxy-3
′, 5′-Di-t-butylphenyl) -5-chlorobenzotriazole, 2,5-bis- [5′-t-butylbenzoxazolyl- (2)]-thiophene, [bis (3,3
5-di-t-butyl-4-hydroxybenzylphosphoric acid monoethyl ester] nickel salt, 2-ethoxy-5-t-
Butyl-2'-ethyloxalic acid-bis-anilide 85-90% and 2-ethoxy-5-t-butyl-
2'-Ethyl-4'-t-butyl oxalic acid-bis-anilide 10-15% mixture, 2- (3,5
-Di-t-butyl-2-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2-ethoxy-2'- Ethyl oxalic acid bisanilide, 2- [2 'hydroxy-5
′ -Methyl-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimido-methyl) phenyl] benzotriazole, bis (5-benzoyl-4-hydroxy-2-)
Methoxyphenyl) methane, 2- (2'-hydroxy-
5'-t-octylphenyl) benzotriazole, 2
-Hydroxy-4-i-octoxybenzophenone, 2
-Hydroxy-4-dodecyloxybenzophenone, 2
-Hydroxy-4-octadecyloxybenzophenone etc. can be mentioned.

[0022] As the antistatic agent, glycerin fatty acid (C ₈ ~C ₂₂₎ esters, sorbitan fatty acid (C ₈ -C
₂₂ ) ester, propylene glycol fatty acid (C _{8 to} C
₂₂₎ esters, sucrose fatty acid (C ₈ -C ₂₂₎ esters,
Citric acid mono (di or tri) stearyl ester, pentaerythritol fatty acid (C ₈ -C ₁₈₎ esters, trimethylolpropane fatty acid (C ₈ -C ₁₈₎ esters, polyglycerin fatty acid (C ₈ -C ₂₂₎ esters, polyoxy ethylene (20 mol) of glycerin fatty acid (C ₁₂ ~
C ₁₈₎ esters, polyoxyethylene (20 moles) sorbitan fatty acid (C ₁₂ -C ₁₈₎ esters, polyethylene glycol fatty acid (C ₈ -C ₂₂₎ esters, polypropylene glycol fatty acid (C ₈ -C ₁₈₎ esters, polyoxyethylene fatty alcohols (C ₁₂ -C ₂₀₎ ethers, polyoxyethylene (4-50 moles) alkyl (C ₄ or higher) phenyl ether, N, N-bis (2-hydroxyethyl) fatty (C ₈ -C ₁₈₎ amines, condensation product with a fatty acid and diethanolamine, polyoxypropylene polyoxyethylene block polymers, polyethylene glycol, non-ionic surfactants such as polypropylene glycol; alkyl (C ₁₀ ~C ₂₀₎ sulfonates (Na,
K, NH _4), alkyl (C ₉ ~C ₂₀₎ benzenesulfonate _{(Na, K, NH 4)} , alkyl naphthalene sulfonate (Na), sodium dialkyl (C ₄ ~C ₁₆₎
Sulfosuccinates, alkyl (C ₈ ~C ₂₀₎ sulphate (Na, K, NH _4), fatty acid (C ₈ ~C ₂₂₎ salt (Na, K, NH ₄₎ anionic surface active agents such as; N-
Acyl (C ₈ ~C ₁₈₎ zwitterionic surfactants such Sarcosinate; Other auxiliaries, such as polyacrylic acid and its sodium salt, and the like.

As the lubricant, hexylamide, octylamide, stearylamide, oleylamide, erucylamide, ethylenebisstearylamide, laurylamide, behenylamide, methylenebisstearylamide,
Saturated or unsaturated aliphatic amides having 3 to 30 carbon atoms such as ricinol amide and derivatives thereof; butyl stearate,
Examples thereof include saturated or unsaturated aliphatic esters having 3 to 30 carbon atoms such as isobutyl stearate and their derivatives; commercially available silicone release agents and silicone compounds such as silicone oil.

Examples of the metal deactivator include 3-N'-salicyloyl-amino-1,2,4-triazole, salicylaldehyde, salicylhydrazine, N, N'-bis [3.
-(3,5-Di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, oxalyl-bis [benzylidenehydrazide], 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 3 , 4,5,6-Dibenzo-1,2-oxaphosphane-2-oxide, tris [2-t-butyl-4]
-Thio (2'-methyl-4'-hydroxy-5-t-butyl) phenyl-5-methyl] phenyl phosphite, 2,2'-oxamido-bis- [ethyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] and the like.

As the nucleating agent, 1,3,2,4-di-benzylidene-sorbitol and 1,3,2,4-di- (p-
Methyl-benzylidene) sorbitol, 1,3,2,4
-Di- (p-ethyl-benzylidene) sorbitol,
1,3,2,4-di- (2 ', 4'-di-methyl-benzylidene) sorbitol, 1,3-p-chloro-benzylidene-2,4-p-methyl-benzylidene-sorbitol, 1,3 , 2,4-Di- (p-propyl-benzylidene) sorbitol, aluminum-mono-hydroxy-di-pt-butylbenzoate, sodium-bis (4-t-butylphenyl) phosphate, sodium-2,2 ′ -Methylene-bis- (4,6-di-t-butyl-phenyl) phosphate, talc, sodium benzoate, lithium-2,2′-methylene-bis- (4.
6-di-t-butylphenyl) phosphate and the like can be mentioned.

As the neutralizing agent and antacid, lithium stearate, 1,2-hydroxylithium stearate,
Sodium stearoyl lactylate, sodium stearate, potassium stearate, lithium behenate, lithium montanate, sodium behenate, sodium montanate,
Calcium stearyl lactate, calcium behenate, calcium montanate, cadmium stearate, cadmium laurate, cadmium ricinoleate, cadmium naphthenate, cadmium 2-ethylhexoate, barium stearate, barium laurate, barium ricinoleate, barium naphthenate, Barium 2-ethylhexoate, calcium stearate, calcium laurate, calcium ricinoleate, strontium stearate, zinc stearate, zinc laurate, zinc ricinoleate, zinc 2-ethylhexoate, lead stearate, dibasic lead stearate, naphthene. Higher fatty acids such as lead oxide, tin stearate, aluminum stearate, magnesium stearate, and alkali or alkaline earth metals such as alkyl lactic acid ; Basic magnesium aluminum aluminum hydroxy carbonate hydrate (hydrotalcite), basic zeolite, epichlorohydrin and bisphenol A polymers, epoxidized soybean oils, epoxidized fatty acid monoesters, epoxidized alicyclic Examples thereof include fatty acid esters.

As the filler, magnesium oxide, aluminum oxide, silicon oxide, calcium oxide, titanium oxide, chromium (III) oxide, iron oxide, zinc oxide, silica, diatomaceous earth, alumina fiber, antimony oxide, barium ferrite, strontium ferrite , Oxides such as beryllium oxide, pumice, pumice balloons, basic substances or hydroxides such as magnesium hydroxide, aluminum hydroxide, basic magnesium carbonate; magnesium carbonate, calcium carbonate,
Carbonates such as dolomite and dawsonite; (sulfite) salts such as calcium sulfate, barium sulfate, ammonium sulfate, calcium sulfite, basic magnesium sulfate; sodium silicate, magnesium silicate, aluminum silicate, potassium silicate, calcium silicate, talc, clay, Mica,
Silicates such as asbestos, glass fiber, montmorillonite, glass balloon, glass beads, pentonite, etc .; kaolin (ceramic), perlite, iron powder, copper powder, lead powder, aluminum powder, molybdenum sulfide, boron fiber, silicon carbide fiber, brass Fiber, potassium titanate, lead zirconate titanate, zinc borate, aluminum borate, barium metaborate,
Examples thereof include calcium borate and sodium borate.

When the treated product and the unused plastic are mixed and used, depending on the performance of the final product,
The treated plastic is generally 1% by weight or more, preferably 3
% Or more, particularly preferably 5% by weight or more.
It should be noted that unpainted used plastic can be used in place of virgin plastic.

(3) Forming The above-mentioned hot-water and / or steam-treated molded body substrate is melted again in an extruder and pelletized for recycling. The extruder used for pelletizing is not special, and a generally used single-screw or twin-screw extruder can be used. The extruder can also be removed by using a wire mesh of 20 to 200 μm, a filter or the like in order to remove dust, metals and the like that could not be removed in the hot water treatment step. However, re-pelletization by an extruder is not essential, and the final product can be directly molded. As the molding method, various molding methods such as injection molding, extrusion molding, blow molding, transfer molding, and press molding can be adopted. The molding conditions are appropriately set depending on the properties of the plastic, the shape of the molded product, and the like.

(4) Coating The regenerated molded article base material is re-coated by re-coating with a coating material such as the organic solvent-based coating material, the water-soluble resin coating material, the water-dispersible resin coating material and the aqueous emulsion coating material. It can also be a plastic molding.

(5) Product The above recycled plastic molded product can be applied again as various industrial products. Specifically, automotive bumpers, wheel caps, automobile exterior parts such as side moldings, instrument panels, interior parts such as levers and linings, vacuum cleaners, washing machines, refrigerators, lighting equipment, audio equipment, and other electrical products. , Miscellaneous sundries such as color boxes and storage cases.

[0032]

EXAMPLES In order to explain in more detail the method for treating a coated plastic molded article of the present invention and the method for recycling the same,
Hereinafter, the examples and the comparative examples will be specifically described. However, the present invention is not limited to these examples. The evaluations in the following examples and comparative examples are measured by the evaluation methods shown below. [I] Evaluation method (1) Bending test The bending test was performed according to JIS K7203. (2) Tensile test The test was conducted according to JIS K7113. Tensile speed: 50mm
/ Min (3) Izod impact test It was performed according to JIS K7110. Measurement temperature 23 ℃ and-
Performed at 30 ° C. (4) Drop weight impact strength A test piece (120 m) installed on a support (hole diameter 40 mm)
A dart, which is a load sensor, was dropped (2 m x 4 kgf) onto a m x 80 mm, thickness 2 mm), the deformation and fracture behavior of the test piece under an impact load was measured, and the impact absorbed up to the crack initiation point in the obtained impact pattern. The energy was calculated and used as the impact strength of the material. Measurement temperature is -30
Performed at ° C. (5) Exterior The surface of the injection-molded product (120 mm × 80 mm, thickness 2 mm) was visually observed and evaluated according to the following evaluation criteria. ◯: The surface of the molded product is the same as the surface of the molded product formed only by the base material not containing the coating film, and the surface roughness is not observed. ○ ⁻ : It is almost the same as the surface of the molded product formed by the base material alone, but some small irregularities are observed on the surface. X: A part of the coating film is observed on the surface and surface roughness is remarkable,

[II] Experimental Example Example 1 (1) Production of Molded Body Base Resin (A) Melt flow rate (MF) with ethylene content of 4% by weight
R) is 60 g / 10 min, the propylene / ethylene block copolymer is 60% by weight, and the ethylene content is 80% by weight, and the Mooney viscosity (ML1 + 4) measured at 100 ° C. is 50.
30% by weight of the ethylene / propylene copolymer rubber of 10% by weight and 10% by weight of talc having an average particle size of 1.7 μm were mixed to prepare a molding material base resin A.

(2) Manufacture of coated plastic product (A) Using the J-100 type injection molding machine manufactured by Nippon Steel Co., Ltd., the molding base resin A was molded at a molding temperature of 210 ° C. and an injection pressure of 500 kg.
/ Cm injection molded article at ² conditions (120 mm × 120
mm × 3 mm) was molded. Then, the injection-molded article was steam-cleaned with 1,1,1-trichloroethane, and one surface (120 mm × 120 mm) thereof was disclosed in JP-A-59-98140.
Plasma treatment by the method described in Japanese Patent Publication (apparatus: microwave plasma treatment apparatus (TMZ-9602B manufactured by Toshiba Corp.), conditions: oxygen gas flow rate 400 cc / min, pressure 0.5 to.
rr, output 400 W, processing time 10 seconds), and a one-component white paint made by Nippon Bee Chemical Co., Ltd. (with a melamine-based cross-linking component) having a polyester resin component and a urethane bond at a thickness of 40 μm. After coating, baking was performed in an oven at a temperature of 120 ° C. for 30 minutes to produce a coated plastic product A.

(3) Pulverizing treatment This coated plastic product A is a pulverizer BO manufactured by Horai Co., Ltd.
It was crushed to a size of about 5 mm square by -3084 type. (4) Hot water treatment 10 kg of the pulverized product of the coated plastic product A was placed in a pressure-resistant autoclave with an internal volume of 100 liter equipped with a stirrer, 50 liters of water was further added, and the temperature was raised to 145 ° C with stirring, ² under pressure of 3.7 kg / cm 2.
Hot water treatment was performed for an hour. After the hot water treatment, dehydration was performed with a centrifuge. (5) Manufacture of Pellets The crushed and hot water treated product of the coated plastic product A dehydrated after the hot water treatment was used with a TEM35 twin-screw extruder manufactured by Toshiba Machine Co., Ltd., with a cylinder set temperature of 200 ° C. and a screw rotation speed of 250 rpm. Pellets were produced by melting and kneading under the conditions. The extrusion rate at this time was set to 30 kg / hr using a feeder.

(6) Molding The above pellets were molded with a J-100 injection molding machine manufactured by Nippon Steel Co., Ltd. under the conditions of a molding temperature of 210 ° C. and an injection pressure of 500 kg / cm ² , and a test piece for measuring physical properties. Got (7) Measurement of Physical Properties Using the test pieces molded by the above molding machine, physical properties were measured by the above-mentioned measuring method of physical properties. The results are shown in Table 1.

Comparative Example 1 The pulverized product of the coated plastic product A produced in "(3) Pulverizing treatment" of Example 1 was pelletized by the extruder used in "(5) Pellet production" of Example 1. And then
A test piece for measuring physical properties was molded by the molding machine used in “(6) Molding”, and physical properties were measured. The results are shown in Table 1.
Shown in. The obtained results showed that the elongation at break was 483% at maximum and 55% at minimum, and the variations were remarkable. Also,
Fragments of the coating film were visually observed on the surface, and the surface irregularities were remarkable.

Example 2 30% by weight of a crushed / hot-water treated product of the coated plastic product A which was subjected to the hot water treatment in "(4) Hot water treatment" of Example 1 and "(1) Molded product of Example 1" 70% by weight of the molded base material resin A produced in "Production of base resin (A)" was mixed and pelletized using the extruder used in "(5) Production of pellets" of Example 1. After that, a test piece for measuring physical properties was further molded with the molding machine used in “(6) Molding”, and physical properties were measured. The results are shown in Table 1.

Comparative Example 2 30% by weight of the pulverized product of the coated plastic product A produced in "(3) Pulverizing treatment" of Example 1 and "(1) of Example 1"
Molded product base resin A manufactured in "Production of molded product base resin (A)" (70% by weight) is mixed and pelletized by using the extruder used in "(5) Production of pellets" in Example 1. After that, a test piece for measuring physical properties was further molded by the molding machine used in “(6) Molding”, and physical properties were measured. The results are shown in Table 1. The results obtained showed that the elongation at break was highly variable and the surface irregularities were significant.

Example 3 (1) Manufacture of painted plastic product (B) The molded product base resin A manufactured in "(1) Manufacture of molded product base resin (A)" of Example 1 was manufactured by Nippon Steel Corporation. Using J-100 type injection molding machine, the molding temperature is 210 ° C., the injection pressure is 500.
Injection-molded product (120 mm x 1 under the condition of kg / cm ²
20 mm × 3 mm) was molded. Then, the injection-molded product was steam-cleaned with 1,1,1-trichloroethane, and one side (120 mm × 120 mm) was undercoated with a primer containing chlorinated polypropylene as a component to a thickness of 10 μm, and then for 10 minutes. After flushing at room temperature,
A paint of Nippon Bee Chemical Co., Ltd. (a melamine-based cross-linking component) is used as a one-component white paint whose resin component is polyester and contains urethane bond.
The coated plastic product B was obtained by baking at a temperature of 0 ° C. for 30 minutes. (2) Pulverization Treatment The coated plastic product B was pulverized to a size of about 5 mm square by using the same device as above.

(3) Hot water treatment 10 kg of this pulverized product was placed in a pressure resistant autoclave with an internal volume of 100 liter equipped with a stirrer, 50 liters of water was added thereto, and the temperature was raised to 125 ° C. with stirring. Was subjected to hot water treatment for 3 hours under a pressure of 3.0 kg / cm ² . After the hot water treatment, dehydration was performed with a centrifuge. (4) Manufacture of pellets 30% by weight of a crushed / hot-water treated product of the coated plastic product B dehydrated after the above-mentioned hot water treatment, and the molded product manufactured in "(1) Manufacture of base resin for molded product" of Example 1. Base resin A
70 wt% was mixed and melted and kneaded using a TEM35 twin-screw extruder manufactured by Toshiba Machine Co., Ltd. at a cylinder set temperature of 200 ° C. and a screw rotation speed of 250 rpm to produce pellets. At this time, the extruder was equipped with a filter using a wire mesh of 1,000 mesh. The extrusion rate was set to 30 kg / hr using a feeder. (5) Molding The above pellets were molded with a J-100 injection molding machine manufactured by Nippon Steel Co., Ltd. under the conditions of a molding temperature of 210 ° C. and an injection pressure of 500 kg / cm ² to obtain test pieces for measuring physical properties. .. (6) Measurement of Physical Properties Using a test piece molded by the above molding machine, physical properties were measured by the above-mentioned measuring method of physical properties. The results are shown in Table 1.

Comparative Example 3 (1) Production of Pellet Pulverized product 30 of coated plastic product B produced in "(1) Production of coated plastic product (B)" of Example 3
% By weight and 70% by weight of the molded body base resin A produced in “(1) Production of molded body base resin (A)” of Example 1 were mixed, and a TEM35 twin screw extruder manufactured by Toshiba Machine Co., Ltd. was mixed. Cylinder set temperature 200 ℃, screw rotation speed 250r
Pellets were produced by melting and kneading under the condition of pm. At this time, the extruder was equipped with a filter using a wire mesh of 1,000 mesh. Under these conditions, the extrusion rate could not be increased by venting up the resin from the vent port, so the extrusion rate was 1 kg / hr. Also,
The extrusion rate tended to decrease as the filter clogged. (2) Molding The above pellets were molded with a J-100 injection molding machine manufactured by Nippon Steel Co., Ltd. under the conditions of a molding temperature of 210 ° C. and an injection pressure of 500 kg / cm ² to obtain test pieces for measuring physical properties. .. (3) Measurement of Physical Properties Using the test pieces molded by the above molding machine, the physical properties were measured by the measuring method of physical properties described above. The results are shown in Table 1. The obtained results show that the maximum elongation at break is 585%.
To a minimum of 63%, the variation was remarkable.

Example 4 (1) Steam treatment 10 kg of a pulverized product of the coated plastic product A obtained by the "(3) pulverization treatment" of Example 1 was placed in a pressure-resistant autoclave having a 100 liter internal volume with a stirrer. The water vapor treatment was performed by adding water vapor at a temperature of 150 ° C. for 3 hours while stirring at a speed of 200 rpm without adding water. After the steam treatment, dehydration was performed with a centrifuge. (2) Production of pellets 30% by weight of the steam-treated coated plastic product A crushed and steam-treated, and the molded body substrate manufactured in "(1) Manufacturing of molded body base resin (A)" of Example 1 70% by weight of material resin A was mixed and melted and kneaded using a TEM35 twin-screw extruder manufactured by Toshiba Machine Co., Ltd. at a cylinder temperature of 200 ° C. and a screw rotation speed of 250 rpm to produce pellets. Also, the extrusion rate is 3 using the feeder.
It was set to 0 kg / hr. (3) Molding The above pellets were molded in a J-100 injection molding machine manufactured by Nippon Steel Co., Ltd. under the conditions of a molding temperature of 210 ° C. and an injection pressure of 500 kg / cm ² to obtain test pieces for measuring physical properties. .. (4) Measurement of Physical Properties Using the test pieces molded by the above molding machine, the physical properties were measured by the above-mentioned measuring method of physical properties. The results are shown in Table 1.

Example 5 (1) Production of molded base resin (B) Ethylene content of 4% by weight and melt flow rate of 30
g / 10 min propylene / ethylene block copolymer 5
6% by weight, 24% by weight of ethylene / propylene copolymer rubber having an ethylene content of 72% by weight and a Mooney viscosity (ML1 + 4) of 75 measured at 100 ° C., and 20% by weight of talc having an average particle size of 1.7 μm. A molded body base resin B made of a resin composition obtained by mixing and was produced. (2) Manufacture of coated plastic product (C) Using the J-100 injection molding machine manufactured by Nippon Steel Co., Ltd., the molding base resin B is molded at a temperature of 210 ° C. and an injection pressure of 500 kg.
/ Cm injection molded article at ² conditions (120 mm × 120
mm × 3 mm) was molded. Then, the injection-molded product was steam-cleaned with 1,1,1-trichloroethane, and one side (120 mm × 120 mm) was undercoated with a primer containing chlorinated polypropylene as a component to a thickness of 10 μm, and then for 10 minutes. After flushing at room temperature, 40 μm of 1-component white paint manufactured by Kansai Paint Co., Ltd. in which the resin component of the paint is acrylic (the cross-linking component is melamine)
After coating with the thickness of No. 3, it was baked in an oven at a temperature of 120 ° C. for 30 minutes to obtain a coated plastic product C. (3) Pulverization treatment This coated plastic product C was pulverized to a size of about 5 mm square using the same device as above.

(4) Hot water treatment 10 kg of the crushed product of the coated plastic product C was placed in a pressure-resistant autoclave with an internal volume of 100 liter equipped with a stirrer, 50 liters of water was further added, and the temperature was raised to 145 ° C. with stirring. Allow to warm and pressurize at 3.7 kg / cm ² for 2
Hot water treatment was performed for an hour. After the hot water treatment, dehydration was performed with a centrifuge. (5) Production of pellets The crushed / hot water treated product of the coated plastic product C dehydrated after the above hot water treatment was used with a TEM35 twin-screw extruder manufactured by Toshiba Machine Co., Ltd., with a cylinder set temperature of 200 ° C. and a screw rotation speed of 250 rpm. Pellets were produced by melting and kneading under the conditions. The extrusion rate at this time was set to 30 kg / hr using a feeder. (6) Molding The above pellets were molded with a J-100 injection molding machine manufactured by Nippon Steel Co., Ltd. under the conditions of a molding temperature of 210 ° C. and an injection pressure of 500 kg / cm ² to obtain test pieces for measuring physical properties. .. (7) Measurement of Physical Properties Using the test pieces molded by the above molding machine, physical properties were measured by the above-mentioned measuring method of physical properties. The results are shown in Table 2.

Comparative Example 4 In the "(5) Pellet production" of Example 1, the coated plastic product A was produced by the "(3) Pulverization treatment" of the above Example 5 instead of the pulverized / hot water treated product. "(5) of Example 1 except that the crushed product of the coated plastic product C was used.
Pellets are manufactured in the same manner as in "Production of pellets", and then "(6) Forming" is performed to form test pieces.
The physical properties were evaluated. The results are shown in Table 2. The obtained results are that the tensile elongation is remarkably reduced like other comparative examples,
The unevenness was so remarkable that fragments of the coating film were visually observed on the surface.

Example 6 The pulverized product of the coated plastic product C produced in "(3) Pulverizing treatment" of Example 5 above was treated with hot water in the same manner as in "(4) Hot water treatment" of Example 1. 30% by weight of the crushed and hot water treated plastic product C was mixed with 70% by weight of the molded product base resin B obtained by "(1) Production of molded product base resin (B)" of Example 5. After making pellets by using the extruder used in "(5) Pellet production" of Example 1, test pieces for measuring physical properties were further prepared by the molding machine used in "(6) Molding". After molding, the physical properties were measured. The results are shown in Table 2.

Comparative Example 5 30% by weight of the pulverized product of the coated plastic product C produced in "(3) Crushing treatment" of Example 5 above and "(1) Molded base resin (B) of Example 5" 70% by weight of the molded product base resin B obtained in "Production of pellets" was mixed into pellets using the extruder used in "(5) Production of pellets" in Example 1, and then "(6 ) A molding machine used in "molding" was used to mold a test piece for measuring physical properties, and the physical properties were measured. The results are shown in Table 2.

Example 7 (1) Manufacture of coated plastic product (D) The molded product base resin B manufactured in "(1) Manufacture of molded product base resin (B)" of Example 5 was manufactured by Nippon Steel J-10
Using 0 type injection molding machine, molding temperature 210 ℃, injection pressure 5
Injection-molded product (120 mm x 120 mm x 3 m) of the molded base resin B molded by injection molding under the condition of 00 kg / cm ^2.
m) was steam-washed with 1,1,1-trichloroethane, and one side (120 mm × 120 mm) was primed with a primer containing chlorinated polypropylene as a thickness of 10 μm and then flushed at room temperature for 10 minutes. ,
40μ of 1-component white paint made by Nippon Paint Co., Ltd. in which the resin component of the paint is acrylic (the cross-linking component is melamine)
After coating with a thickness of m, baking was performed in an oven at a temperature of 120 ° C. for 30 minutes to obtain a coated plastic product D. (2) Crushing treatment This coated plastic product D was crushed to a size of about 5 mm square by using the same device as above. (3) Hot water treatment 10 kg of this pulverized product was placed in a pressure-resistant autoclave with an internal volume of 100 liter equipped with a stirrer, 50 liters of water was added, and the temperature was raised to 145 ° C. with stirring and 3.7 kg.
Hot water treatment was performed for 2 hours under a pressure of / cm ² . After treating with the hot water, dehydration was performed with a centrifuge. (4) Manufacture of pellets Crushed product 30 of the above-mentioned hot water treated coated plastic product D
% By weight, and 70% by weight of the molded body base resin B produced in “(1) Production of molded body base resin (B)” of Example 5 above are mixed to give “(5) Pellets of Example 1”. After pelletizing using the extruder used in "Production of", further "(6)
A test piece for measuring physical properties was molded by the molding machine used in "molding", and the physical properties were measured. The results are shown in Table 3.

Comparative Example 6 30% by weight of the pulverized product of the coated plastic product D produced in "(2) Pulverizing treatment" of Example 7 and the above-mentioned Example 5
Extrusion used in "(5) Production of pellets" of Example 1 by mixing with 70% by weight of the molding base resin B produced in "(1) Production of molded base resin (B)" After making it into pellets using a machine, a test piece for measuring physical properties was further molded with the molding machine used in “(6) Molding”, and the physical properties were measured. The results are shown in Table 3. The obtained results were that the tensile elongation was remarkably reduced and the surface irregularities were remarkable.

Example 8 (1) Molded Base Material Resin (C) As an application example of the engineering resin and the styrene resin, "Nonyl PX0844" manufactured by GE Plastics Japan, which is a blend of polyphenylene ether and high-impact polystyrene, is used. It was used as a molded body substrate resin C. (2) Production of coated plastic product (E) The above-mentioned molded body substrate resin C was subjected to a cylinder temperature of 280 ° C. and a mold temperature of 80 with a J-100 injection molding machine manufactured by Nippon Steel Co., Ltd.
An injection-molded product (120 mm x 120 mm x 3 mm) was molded under the conditions of ° C and an injection pressure of 600 kg / cm ² , and one side (120 mm x 120 mm) of the obtained injection-molded product.
On the surface of the paint, a one-component white paint made by Kansai Paint Co., Ltd. whose resin component of the paint is acrylic (the cross-linking component is melamine) is used.
Painted to a thickness of 0 μm and baked in an oven at 120 ° C for 30 minutes to obtain a coated plastic product E
Got (3) Pulverizing treatment This coated plastic product E was pulverized to a size of about 5 mm square using the same device as above.

(4) Hot water treatment 10 kg of the pulverized product of the coated plastic product E was placed in a pressure-resistant autoclave with an internal volume of 100 liter equipped with a stirrer, 50 liters of water was further added, and the temperature was raised to 145 ° C. with stirring. Warm up and pressurize at 3.7 kg / cm ² for 2
Hot water treatment was performed for an hour. After the hot water treatment, dehydration was performed with a centrifuge. (5) Manufacture of pellets 30% by weight of a crushed / hot-water treated product of the coated plastic product E dehydrated after the hot-water treatment, and the molded body base resin C7.
0 wt% was mixed and melted and kneaded using a TEM35 twin-screw extruder manufactured by Toshiba Machine Co., Ltd. at a cylinder temperature of 250 ° C. and a screw rotation speed of 250 rpm to produce pellets. The extrusion rate at this time was set to 30 kg / hr using a feeder. (6) Molding The above pellets were molded on a J-100 JS injection molding machine manufactured by Nippon Steel Co., Ltd. at a molding temperature of 280 ° C, a mold temperature of 80 ° C and an injection pressure of 600.
Molding was carried out under the condition of kg / cm ² to obtain a test piece for measuring physical properties. The results are shown in Table 3.

Comparative Example 7 (1) Manufacture of Pellets 30% by weight of the pulverized product of the coated plastic product E produced in "(3) Crushing" of Example 8 and 70% by weight of the above-mentioned molded body base resin C And TEM35 manufactured by Toshiba Machine Co., Ltd.
Using a twin-screw extruder, the pellets were produced by melting and kneading at a cylinder temperature of 250 ° C. and a screw rotation speed of 250 rpm. The extrusion rate at this time was set to 30 kg / hr using a feeder. (2) Molding The above pellets were molded on a J-100 model injection molding machine manufactured by Nippon Steel Co., Ltd. at a molding temperature of 280 ° C, a mold temperature of 80 ° C, and an injection pressure of 600.
Molding was carried out under the condition of kg / cm ² to obtain a test piece for measuring physical properties. The results are shown in Table 3.

[0054]

[Table 1]

[0055]

[Table 2]

[0056]

[Table 3]

[0057]

EFFECTS OF THE INVENTION In such a method for treating a coated plastic molded article of the present invention, the coating film is not separated from the plastic molded article, but is regenerated by contacting it with hot water and / or steam of 100 ° C. or higher. Therefore, it is possible to recycle plastics at low cost and with low pollution without impairing physical properties and surface appearance.

Claims (4)

[Claims] 1. A plastic molded product having a part or all of its surface coated, at 100 ° C. with or without fragmentation.
A method for treating a coated plastic molded article, which comprises contacting with the above hot water and / or steam. 2. The method for treating a coated plastic molded article according to claim 1, wherein the plastic molded article is at least one of polyolefin, engineering resin, and styrene resin. 3. The resin component of the paint is either acrylic or polyester, and the crosslinking component is melamine.
The method for treating the coated plastic molding according to claim 1 or 2. 4. A plastic molding having a part or all of its surface coated, at 100 ° C. with or without fragmentation.
After being brought into contact with the above hot water and / or steam, it is melted and molded again into fragments or without fragmentation, or with or without mixing with other optional components. How to regenerate the body.