JP2011190359A - Crushing method of thermoplastic resin molded article, method of manufacturing spall of thermoplastic resin molded article, and method of manufacturing regenerated thermoplastic resin molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a regenerated thermoplastic resin molded article of high quality by forming spalls of different sizes using spalls (A) obtained from degraded parts in a surface degrading step and spalls (B) obtained from the other parts than the degraded parts. <P>SOLUTION: The method for manufacturing the regenerated thermoplastic resin molded article includes: a surface degrading step of degrading the surface of a thermoplastic resin molded article by ultraviolet irradiation; a crushing step of crushing the spalls (A) obtained from the degraded parts in the surface degrading step and spalls (B) obtained from the other parts than the degraded parts so that the spalls (A) and the spalls (B) have a different mean maximum diameter; a separating step of separating the spalls (B) among the spalls (A) and the spalls (B); and a molding step of the regenerated thermoplastic resin molded article of molding and regenerating the thermoplastic resin molded article. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for crushing a thermoplastic resin molded product, a method for producing a crushed piece of a thermoplastic resin molded product, and a method for producing a recycled thermoplastic resin molded product.

  Thermoplastic resins such as polycarbonate-based (PC-based) resins are used for various applications, and in particular, are used for various home appliances, various parts of automobiles, casings, and the like. In addition, thermoplastic resins such as alloy resins in which styrene (PS) resin or acrylonitrile styrene (ABS) resin is blended with PC resin are used for parts such as office equipment and electronic and electrical equipment casings. ing. For this reason, when the above parts are manufactured or after the parts are used, waste materials of thermoplastic resins such as PC resins and their alloy resins are discharged in large quantities, and in recent years material recycling that effectively uses these waste materials (Recycling) is desired.

  Here, the material recycling means that the recovered thermoplastic resin waste material (waste plastic) is separated, crushed and washed, and this is used as a raw material (hereinafter referred to as “crushed material”) to produce recycled plastic. There are two types of material recycling: horizontal recycling, which is recycled at the same level as the resin used, depending on the quality of the crushed material, and cascade cascade, which is recycled as a lower quality resin than the quality of the resin used. . In this specification, recycling refers to the horizontal recycling described above.

  In the horizontal recycling described above, it is desired that the quality of the crushed material is equal to that of a newly manufactured resin (hereinafter referred to as “virgin resin”), not a recycled material. For this reason, the crushed material is required to have a composition equivalent to that of the virgin resin, and in recycling, a method is used in which the recovered resin is crushed after being classified into the same or similar grade.

Here, as a factor that lowers the quality of the crushed material, foreign materials are attached or deteriorated depending on the use conditions in the market, and the degree thereof is different. On the other hand, it has been proposed that the degree of deterioration is obtained by the use situation in the market or by measurement, and recycling is performed according to the degree of deterioration (see, for example, Patent Documents 1 and 2).
Further, since most of the deterioration and foreign matter are present on the surface of the recovered thermoplastic resin (waste material), a method using a crushed material from which the surface portion has been removed has been proposed. As a method for removing the surface, a method of irradiating with high-pressure water (for example, see Patent Document 3) and a method for rubbing the crushed materials at the time of crushing to wear the surface (for example, see Patent Documents 4 and 5) have been proposed. .

  In addition, a method of crushing after degrading the resin once, specifically, a method of crushing after deteriorating the resin by leaving the resin in an ozone atmosphere and irradiating with ultraviolet rays has been proposed (for example, (See Patent Documents 6 and 7). Note that the crushed material obtained by this method is subdivided into small pieces having a substantially uniform size.

  In addition, in the processing of nuclear power cables, a method has been proposed in which the surface portion is deteriorated by irradiating ultraviolet rays, and the deteriorated resin is dissolved in a solvent to remove the surface portion (see, for example, Patent Document 8).

Japanese Patent No. 3275462 JP 2006-123193 A Japanese Patent Laid-Open No. 7-80839 JP 2004-122575 A JP 2004-42461 A Japanese Patent No. 3307629 Japanese Patent No. 3761161 JP 2002-174695 A

  The object of the present invention is that the crushed piece (A) obtained from the portion deteriorated by the surface deterioration process and the deterioration as compared with the case where the surface is deteriorated by irradiating the thermoplastic resin molded body with ultraviolet rays is not crushed. The purpose is to form crushed pieces having different sizes from the crushed pieces (B) obtained from portions other than the portion.

The above object is achieved by the present invention described below.
That is, the invention according to claim 1
A surface deterioration process that deteriorates the surface by irradiating the thermoplastic resin molding with ultraviolet rays,
And the crushing process which crushes so that the average longest diameter may differ with the crushing piece (A) obtained from the part deteriorated by the said surface deterioration process, and the crushing piece (B) obtained from parts other than the said deteriorated part. It is the crushing method of the thermoplastic resin molding which has.

The invention according to claim 2
Crushing of a thermoplastic resin molded body having a separation step of separating the crushed pieces (B) among the crushed pieces (A) and the crushed pieces (B) obtained by being crushed by the crushing method according to claim 1. It is a manufacturing method of a piece.

The invention according to claim 3
It has the reproduction | regeneration thermoplastic resin molding formation process which shape | molds and reproduces a thermoplastic resin molding using the crushing piece (B) manufactured by the manufacturing method of the crushing piece of the thermoplastic resin molding of Claim 2. This is a method for producing a recycled thermoplastic resin molded article.

  According to the first aspect of the present invention, compared to the case where the thermoplastic resin molded body is irradiated with ultraviolet rays to deteriorate the surface and then not crushed, the crushed pieces (A) obtained from the portion deteriorated by the surface deterioration process The crushed pieces having different sizes are formed by the crushed pieces (B) obtained from portions other than the deteriorated portion.

  According to the invention which concerns on Claim 2, compared with the case where the thermoplastic resin molding crushed by the crushing method of Claim 1 is not used, a high quality crushing piece is manufactured.

  According to the invention which concerns on Claim 3, compared with the case where the crushed piece (B) of the thermoplastic resin molded object obtained by the manufacturing method of Claim 2 is not used, a high quality recycled thermoplastic resin molded object is obtained. Manufactured.

It is a schematic diagram which shows an example of the components of an electronic / electric equipment provided with the resin molding which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described.
The method for crushing a thermoplastic resin molded body according to the present embodiment includes a surface deterioration step of irradiating the thermoplastic resin molded body with ultraviolet rays to deteriorate the surface, and a crushed piece obtained from a portion deteriorated by the surface deterioration step ( A crushing step of crushing so that the average longest diameter differs between A) and crush pieces (B) obtained from parts other than the deteriorated part is characterized.

  Moreover, the manufacturing method of the crushing piece of the thermoplastic resin molding which concerns on this embodiment is the said crushing piece (A) and the said crushing piece which were obtained by crushing with the crushing method of the thermoplastic resin molding which concerns on the said this embodiment. Among (B), it has the isolation | separation process which isolate | separates the said crush piece (B), It is characterized by the above-mentioned.

  Furthermore, the method for producing a recycled thermoplastic resin molded article according to the present embodiment uses a crushed piece (B) produced by the method for producing a crushed piece of a thermoplastic resin molded article according to the present embodiment, and is thermoplastic. It has the reproduction | regeneration thermoplastic resin molding formation process which shape | molds and reproduces a resin molding.

Plastics (thermoplastic resin) collected after being used in the market have foreign matters attached to the surface or deteriorated due to the conditions of use in the market. When recycled, the surface part deteriorates and deteriorates. It is desirable to efficiently separate other parts that are not.
In contrast, according to the method for crushing a thermoplastic resin molded body according to the present embodiment, crushed pieces having different sizes are formed between the deteriorated surface portion and the other portions that have not deteriorated. In addition, according to the method for producing a crushed piece of a thermoplastic resin molded body according to the present embodiment, only other parts that have not deteriorated are efficiently separated from the crushed pieces having different sizes, and the quality is high. Fragment pieces are produced. Furthermore, according to the method for manufacturing a recycled thermoplastic resin molded body according to the present embodiment, a high-quality recycled thermoplastic resin molded body is manufactured using the high-quality crushed pieces.

This effect is not necessarily clear, but is presumed to be due to the following mechanism. That is, only the surface portion of the thermoplastic resin is acceleratedly deteriorated by irradiation with ultraviolet rays. A thermoplastic resin in which only the surface portion has deteriorated by ultraviolet irradiation causes color change (mainly yellowing), generation of cracks, a decrease in molecular weight, and the like on the surface portion. When the molecular weight is lowered, the impact resistance strength is lowered. When the thermoplastic resin is crushed in this state, the portion is crushed more finely than the portion not deteriorated by the ultraviolet irradiation. Therefore, when the surface portion is deteriorated by ultraviolet irradiation and then crushed, the surface portion becomes a very small crushed piece (crushed piece (A)). On the other hand, the portion not deteriorated by ultraviolet irradiation is crushed. It is presumed that the crushed pieces (crushed pieces (B)) having the longest diameter larger than the pieces are formed.
In addition, by forming crushed pieces with different sizes (different in average longest diameter) between the surface portion and other portions, it is easy to separate the surface portion from other portions. A high-quality recycled thermoplastic resin molded article is produced by using only the crushed pieces of the other parts that are not deteriorated due to use or adhered to foreign matter.

  That is, the present inventors have deteriorated only the surface part by ultraviolet irradiation (surface deterioration process) and then crushed (crushing process), so that the surface part and other parts can be crushed under the same conditions. It was found that crushed pieces of different sizes can be easily obtained.

  The thermoplastic resin molded body used in the crushing method according to the present embodiment refers to a thermoplastic resin molded body made of the same material with no coating film or the like formed on the surface. Therefore, in the case of a thermoplastic resin molded body having a coating film or the like formed on the surface, the crushing method according to the present embodiment is used for the thermoplastic resin molded body after the coating film or the like is removed.

  Hereafter, each process in the crushing method of the thermoplastic resin molding which concerns on this embodiment, the manufacturing method of the crushing piece of a thermoplastic resin molding, and the manufacturing method of a reproduction | regeneration thermoplastic resin molding is explained in full detail, respectively.

<Method of crushing thermoplastic resin molding>
(Thermoplastic resin molding)
First, the thermoplastic resin molding used for the crushing method of this embodiment is demonstrated.
As the thermoplastic resin, a thermoplastic resin such as polycarbonate (PC) resin is used for home appliances, various parts of automobiles, cases and the like, and also for parts such as cases of office equipment and electronic and electrical equipment. A thermoplastic resin such as an alloy resin in which a styrene (PS) resin or an acrylonitrile styrene (ABS) resin is blended with a PC resin is used. When the above-described parts are manufactured or after the parts are used, a large amount of the thermoplastic resin waste material is discharged, and these waste materials are collected for the purpose of recycling.
These recovered thermoplastic resin moldings are used in the crushing method according to the present embodiment. The recovered thermoplastic resin molded body is desirably used after separating resin parts of the same grade or close grades based on the markings of the resin parts.

  Examples of the thermoplastic resin include the following resins. Polycarbonate resin, polyester resin, polyester carbonate resin, polyphenylene ether resin, polyphenylene sulfide resin, polysulfone resin, polyether sulfone resin, polyarylene resin, polyamide resin, polyether imide resin, polyacetal resin, polyvinyl acetal resin, polyketone resin, poly From ether ketone resin, polyether ether ketone resin, polyaryl ketone resin, polyether nitrile resin, liquid crystal resin, polybenzimidazole resin, polyparabanic acid resin, aromatic alkenyl compound, methacrylic acid ester, acrylic acid ester and vinyl cyanide compound A vinyl polymer or copolymer resin obtained by polymerizing or copolymerizing at least one vinyl monomer selected from the group consisting of Diene-aromatic alkenyl compound copolymer resin, vinyl cyanide-diene-aromatic alkenyl compound copolymer resin, aromatic alkenyl compound-diene-vinyl cyanide-N-phenylmaleimide copolymer resin, vinyl cyanide- (Ethylene-diene-propylene (EPDM))-aromatic alkenyl compound copolymer resin, polyolefin, vinyl chloride resin, chlorinated vinyl chloride resin and the like. Especially, the thermoplastic resin molding containing a polycarbonate resin is used suitably for the crushing method which concerns on this embodiment.

  Here, examples of the polycarbonate (PC) resin include aromatic polycarbonate, polyorganosiloxane-containing aromatic polycarbonate, aliphatic polycarbonate, and alicyclic polycarbonate. Among the above, aromatic polycarbonate is desirable.

The polycarbonate resin may be used as an alloy resin in which at least one polycarbonate resin and at least one styrene resin are combined.
Examples of the styrene resin include GPPS resin (general polystyrene resin), HIPS resin (impact polystyrene), SBR resin (styrene butadiene rubber), ABS resin (acrylonitrile-butadiene rubber-styrene copolymer), and AES resin. (Acrylonitrile-ethylenepropylene rubber-styrene copolymer), AAS resin (acrylonitrile-acrylic rubber-styrene copolymer), MBS resin (methyl methacrylate-butadiene rubber-styrene copolymer), AS resin (acrylonitrile-styrene copolymer) Polymer), MS resin (methyl methacrylate-styrene copolymer), and the like. Among the above, HIPS resin, ABS resin, AS resin and the like are desirable.

  Commercially available polycarbonate / styrene alloy resins include “TN7300”, a PC / ABS alloy resin manufactured by Teijin Chemicals, “NN2710AS”, a PC / HIPS alloy resin manufactured by Idemitsu Kosan Co., Ltd., PC / Examples thereof include “ZFJ61” which is an ABS alloy resin, “C6600” which is a PC / ABS alloy resin manufactured by SABIC.

  The content of the thermoplastic resin in the thermoplastic resin molded body used in the crushing method according to the present embodiment is not particularly limited, but is desirably 10% by mass or more and 50% by mass or less.

(Surface degradation process)
The surface deterioration step in the method for crushing a thermoplastic resin molded body according to the present embodiment is a step of irradiating the thermoplastic resin molded body with ultraviolet rays to deteriorate the surface.
When the surface portion of the thermoplastic resin molded body is irradiated with ultraviolet rays, the thickness of the deteriorated portion is desirably 1 mm or less from the surface, and more desirably 0.2 mm or less.

  When the thermoplastic resin is irradiated with ultraviolet rays, light energy is absorbed and deterioration occurs. The light energy increases as the wavelength is shorter, and in this embodiment, ultraviolet light having a wavelength shorter than 400 nm is used.

  As a light source for irradiating ultraviolet rays, a sunshine weather meter for light resistance test and various ultraviolet irradiation devices are used. As a sunshine weather meter, for example, WEL-SUN-HC manufactured by Suga Test Instruments Co., Ltd. is used, and as various ultraviolet irradiation devices, an ultraviolet irradiation device manufactured by USHIO INC. Is used. As the ultraviolet lamp, a mercury lamp in which mercury is enclosed, a metal halide lamp in which mercury and a halogen gas are enclosed, and the like, and an excimer laser can also be used as an apparatus for irradiating ultraviolet rays, but a mercury lamp and a metal halide lamp are more preferable.

In addition, it is desirable that irradiation of the ultraviolet rays with respect to the thermoplastic resin molding is performed under the following conditions.
Irradiation intensity: 200 W / m ² or more and 2000 W / m ² or less
(More desirably, 500 W / m ² or more and 1000 W / m ² or less)
・ Irradiation time: 1 to 24 hours
(More desirably, 2 hours to 5 hours)
・ Temperature: 10 ℃ to 80 ℃
(More desirably, 25 ° C to 60 ° C)
・ Humidity: 30% RH to 80% RH
(More desirably, 50% RH to 60% RH)
・ Distance to light source: 50mm or more and 1000mm or less
(More desirably, 100 mm to 200 mm)

  In addition, the ultraviolet irradiation with respect to the thermoplastic resin is described in detail in “Polymer degradation mechanism and stabilization technology (CMC Publishing)”.

In addition, a substance that absorbs light is in a high energy state (excited state), and induces thermal deterioration and oxidative deterioration in addition to deterioration due to bond breakage. Accordingly, in the surface deterioration step, in addition to the ultraviolet irradiation, the thermoplastic resin molded body is heated or the thermoplastic resin molded body absorbs moisture within a range not exceeding the thickness of the portion deteriorated by the ultraviolet irradiation. By deteriorating, deterioration may be further promoted. However, it is desirable that the heating be less than the glass transition temperature at which the thermoplastic resin flows, and not be heated for more than 24 hours.
In addition, about deterioration of a thermoplastic resin molded object, there exists a detailed description in "Study on life evaluation of general purpose plastics (Yamanashi Prefectural Industrial Technology Center research report No. 19 (2005))."

(Crushing process)
The crushing step in the method for crushing a thermoplastic resin molded body according to the present embodiment is obtained from a crushed piece (A) obtained from a portion deteriorated by the surface deterioration step and a portion other than the deteriorated portion (other portion). This is a step of crushing so that crushing pieces (B) having different average longest diameters are formed. In the present specification, “crushing” means that energy is applied and destroyed by a physical operation.

In the crushing step, as described above, the crushing pieces (A) obtained from the portion deteriorated by the surface deterioration step (namely, the surface portion) and the crushing pieces (B) obtained from other portions, the crushing pieces having different average longest diameters. Crushing is performed so that
Specifically, the average longest diameter of crushed pieces (B) obtained from other parts is 1 mm or more and 20 mm or less, and the average longest diameter of crushed pieces (A) obtained from deteriorated parts (surface parts) is 0.05 mm or more. The average longest diameter of the crushed pieces (B) is preferably 3 mm or more and 15 mm or less, and the average longest diameter of the crushed pieces (A) is more preferably 0.1 mm or more and 0.5 mm or less.

The average longest diameter is obtained by separating the crushed pieces (A) obtained from the portion (surface portion) deteriorated by the “separation step” described later and the crushed pieces (B) obtained from other portions, and then Measured by method.
Disperse 100 g of each crushed piece in water so that the volume concentration is 5% or less, and pass through sieves with various openings (nominal diameters) while applying vibration. The dry mass after passage was measured, and the average opening diameter was defined as the sieve opening (nominal diameter) that passed 50 g or more. The numerical values described in this specification are measured by the above method.

  As described above, only the surface part is deteriorated by ultraviolet irradiation (surface deterioration process) and then crushed (crushing process), so that even if the surface part and other parts are crushed under the same conditions, the deteriorated part (surface The crushed pieces (A) and the crushed pieces (B) having different sizes in the portion) and other portions are easily formed.

  In addition, as a method of crushing, the method of using a dry or wet crusher is mentioned. As the crusher, a uniaxial crusher that crushes while pressing the object against the rotary blade and scraping it little by little, a biaxial crusher that crushes it with scissors, a hammer crusher that crushes with a hammer, crushing with media Media crushing machines that perform such operations, and other crushing machines that shatter objects by hitting them against metal. In the crushing step, the crushing process may be divided into rough crushing and fine crushing for efficient crushing. As described above, the setting condition of the crusher is desirably set so that the average longest diameter of the crushed pieces (B) obtained from the part other than the part deteriorated by the ultraviolet irradiation (other part) is 1 mm or more and 20 mm or less. Furthermore, it is more desirable to set it to be 3 mm or more and 15 mm or less.

  Specifically, as a desirable setting condition when a wet crusher (PR30-360S-800) manufactured by Tanaka Co., Ltd. is used as a crusher (uniaxial crusher), the processing amount is 10 kg / hour or more and 250 kg / hour. Or less, more preferably 50 kg / hour or more and 150 kg / hour or less.

<Method for producing crushed pieces of thermoplastic resin molding>
(Separation process)
The separation step in the method for producing a crushed piece of a thermoplastic resin molded body according to the present embodiment includes the crushed piece (A) obtained by being crushed by the method for pulverizing a thermoplastic resin molded body according to the present embodiment and the crushed piece. It is the process of isolate | separating the said crushing piece (B) among pieces (B).

Examples of the separation method include a separation method by passing through a filter and a separation method using wind power.
In the separation method by passing through a filter, the opening is larger than the average longest diameter of the crushed pieces (A) obtained from the deteriorated portion (surface portion), and other portions (portions other than the deteriorated portion) The crushed pieces (B) are separated by passing through a filter smaller than the average longest diameter of the crushed pieces (B) obtained from 1. In the method of separating by wind force, the wind speed is adjusted so that the fragment (A) obtained from the deteriorated part (surface part) which is a small fragment is applied to the wind to remove other parts. The fragment (B) obtained from (parts other than the deteriorated part) is separated.

  In addition, you may use separation apparatuses, such as a filter attached to the crusher etc. which were mentioned above for the separation method used for a separation process.

<Manufacturing Method of Recycled Thermoplastic Resin Molded Body>
(Recycled thermoplastic resin molding process)
The recycled thermoplastic resin molded body molding step in the method for manufacturing a recycled thermoplastic resin molded body according to the present embodiment is a crushed piece manufactured by the method for manufacturing a crushed piece of a thermoplastic resin molded body according to the present embodiment (B ) Is used to mold and recycle the thermoplastic resin molded body.

  First, the crushed pieces (B) obtained by the separation step (crushed pieces obtained from a portion other than the deteriorated portion) may be washed with water or the like. As an example of the cleaning method, there is a method of cleaning by putting in a vortex type rotating tub such as a washing machine and stirring. In addition, it is desirable to perform washing | cleaning by water in the temperature range of 10 to 40 degreeC from a viewpoint of suppressing hydrolysis of a thermoplastic resin.

  In the method for producing a recycled thermoplastic resin molded body according to the present embodiment, the crushed pieces (B) obtained by the separation step (crushed pieces obtained from parts other than the deteriorated part) are used, and for example, a flame retardant. And other components and the like are melted and kneaded, and then molded to produce a recycled thermoplastic resin molded article.

  Here, known means are used as the melt kneading means, and examples thereof include a twin screw extrusion, a Henschel mixer, a Banbury mixer, a single screw extruder, a multi-screw extruder, and a kneader. Also, known means are used as the molding means, for example, molding methods such as injection molding, extrusion molding, blow molding, hot press molding, calendar molding, coating molding, cast molding, dipping molding, vacuum molding, transfer molding, etc. Is mentioned.

  The injection molding is performed using a commercially available device such as NEX150 manufactured by Nissei Plastic Industry, NEX70000 manufactured by Nissei Plastic Industry, SE50D manufactured by Toshiba Machine. In this case, the cylinder temperature is preferably 220 ° C. or higher and 280 ° C. or lower, and more preferably 230 ° C. or higher and 270 ° C. or lower. The mold temperature is preferably 40 ° C. or higher and 80 ° C. or lower, and more preferably 50 ° C. or higher and 70 ° C. or lower.

  Next, the flame retardant and other components added to the recycled thermoplastic resin molded body will be described.

-Flame retardant In the said reproduction | regeneration thermoplastic resin molding, you may contain a flame retardant. As the flame retardant, conventionally known flame retardants are used, and an organic phosphorus flame retardant is particularly desirable.
The organophosphorus flame retardant is not particularly limited. For example, melamine polyphosphate, aromatic phosphorus compound, phosphate ester, condensed phosphate ester, phosphinate, phosphonate, phosphazene compound, ammonium polyphosphate, etc. Is mentioned. In the present embodiment, it is desirable to use a condensed phosphate ester that does not contain a halogen-based compound that generates a harmful substance during combustion as a flame retardant.

  Although content of the said flame retardant in the said reproduction | regeneration thermoplastic resin molding is not specifically limited, It is desirable that they are 5 mass% or more and 40 mass% or less.

Other components The recycled thermoplastic resin molded article may further contain other components. The content of the other components in the recycled thermoplastic resin molded article is preferably 0% by mass or more and 10% by mass or less, and more preferably 0% by mass or more and 5% by mass or less. Here, “0 mass%” means a form that does not contain other components.
Examples of the other components include various pigments, modifiers, anti-drip agents, compatibilizers, antistatic agents, antioxidants, weathering agents, antihydrolysis agents, fillers, reinforcing agents (glass fibers, Carbon fiber, talc, clay, mica, glass flake, milled glass, glass beads, crystalline silica, alumina, silicon nitride, alumina nitride, boron nitride, etc.). In addition, the recycled thermoplastic resin molded article in the present embodiment may contain, for example, 0.1% by mass or more and 1% by mass of polytetrafluoroethylene (PTFE) as other components.

  The recycled thermoplastic resin molded article is suitably used for applications such as cases, containers, various parts of automobiles, cases, etc. for office equipment, electronic equipment, electrical equipment, home appliances and the like. More specifically, housings such as home appliances and electronic / electrical equipment, various parts, wrapping films, storage cases such as CD-ROMs and DVDs, tableware, food trays, beverage bottles, chemical wraps, automobiles Various parts.

Here, one application of the recycled thermoplastic resin molded article obtained by the manufacturing method according to the present embodiment will be described.
FIG. 1 is an external perspective view of an image forming apparatus as an example of a part of an electronic / electric device provided with the recycled thermoplastic resin molded body, as viewed from the front side. The image forming apparatus 100 in FIG. 1 includes front covers 120 a and 120 b on the front surface of the main body device 110. These front covers 120a and 120b can be freely opened and closed so that an operator can operate the inside of the apparatus. Thus, the operator replenishes the toner when the toner is exhausted, replaces the exhausted process cartridge, or removes the jammed paper when a paper jam occurs in the apparatus. FIG. 1 shows the apparatus with the front covers 120a and 120b opened.

  On the upper surface of the main unit 110, an operation panel 130 on which various conditions relating to image formation such as a paper size and the number of copies are input by an operation of an operator, and a copy glass 132 on which a document to be read is arranged are provided. Yes. In addition, the main body device 110 includes an automatic document conveying device 134 that conveys a document on the copy glass 132 at the top thereof. Further, main device 110 includes an image reading device that scans a document image placed on copy glass 132 and obtains image data representing the document image. Image data obtained by the image reading apparatus is sent to the image forming unit via the control unit. Note that the image reading device and the control unit are housed in a housing 150 that forms part of the main body device 110. The image forming unit is provided in the housing 150 as a detachable process cartridge 142. The process cartridge 142 is attached and detached by turning the operation lever 144.

  A toner container 146 is attached to the casing 150 of the main body device 110, and toner is replenished from the toner supply port 148. The toner stored in the toner storage unit 146 is supplied to the developing device.

  On the other hand, sheet storage cassettes 140a, 140b, and 140c are provided at the lower portion of the main unit 110. In addition, the main body apparatus 110 has a plurality of conveying rollers formed of a pair of rollers arranged in the apparatus, thereby forming a conveying path through which the sheets of the sheet storage cassette are conveyed to the upper image forming unit. ing. The paper in each paper storage cassette is taken out one by one by a paper take-out mechanism arranged at the end of the transport path and sent out to the transport path. Further, a manual paper supply unit 136 is provided on a side surface of the main apparatus 110, and paper is supplied from here.

  The paper on which the image is formed by the image forming unit is sequentially transferred between two fixing rolls that are supported by a casing 152 that forms part of the main body device 110 and is in contact with each other. Paper is discharged to the outside. The main body device 110 is provided with a plurality of paper discharge sections 138 on the side opposite to the side where the paper supply section 136 is provided, and the paper after image formation is discharged to these paper discharge sections.

  In the image forming apparatus 100, for example, the recycled thermoplastic resin molded body is used for the front covers 120 a and 120 b, the exterior of the process cartridge 142, the casing 150, and the casing 152.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Preparation of collected materials)
The polycarbonate / styrene (PC / PS) alloy resin used for 3 years as a cover for the image forming apparatus (copier) was recovered, and metal parts and seals were removed.

(Preparation of virgin material)
An unused polycarbonate / styrene (PC / PS) alloy resin (manufactured by Teijin Kasei Co., Ltd., trade name: TN7300) having the same grade as that of the recovered material was prepared.

<Example 1>
(Surface degradation process)
The recovered material was irradiated with ultraviolet rays under the following conditions using a metal halide weather resistance tester (Daipura Wintes Co., Ltd., Daipura Metal Weather (KU-R5A)).
Irradiation intensity: 650 W / m ²
・ Irradiation time: 24 hours ・ Temperature: 60 ℃
・ Humidity: 60% RH
・ Distance from light source: 300mm

(Crushing process and separation process)
Using a wet crusher manufactured by Tanaka Co., Ltd. (uniaxial crusher, product name: PR30-360S-800), the collected material whose surface was irradiated with ultraviolet rays was crushed in a shower under the conditions of 100 kg / hr. The crushed material was introduced into the washer through an open 12 mm filter. The washer was worn and washed in water, and further passed through a filter (aperture: 1 mm) attached to the wet crusher to separate and remove small crushed pieces together with drainage. Thereafter, water was sufficiently removed from the crushed pieces remaining on the filter by centrifugation to obtain crushed pieces for regeneration.

  In addition, the average longest diameter of the regenerated crushed pieces (crushed pieces that did not pass through the filter) was 10 mm, and the average longest diameter of the small crushed pieces that passed through the filter was 0.3 mm. When the small crushed pieces that passed through the filter were visually observed, yellowing that was probably caused by ultraviolet irradiation was observed.

<Comparative Example 1>
In the said Example 1, the crushing process and the isolation | separation process were performed without passing through a surface deterioration process, ie, without performing ultraviolet irradiation, and the crushing piece was obtained.
The average longest diameter of the crushed pieces that did not pass through the filter was 10 mm, while there were no small crushed pieces that passed through the filter.

<Reference Example 1>
The virgin material was used.

[Evaluation]
−Measurement of volume rate−
The volume rate (MVR) of the crushed pieces for regeneration obtained in the examples, the crushed pieces obtained in the comparative example, and the virgin material of the reference example was measured using a melt indexer (F-F01, manufactured by Toyo Seiki Seisakusho Co., Ltd.). ). The measurement was performed according to ASTM D1238, and the conditions were a cylinder temperature of 260 ° C. and a load of 2.16 kg. The results are shown in Table 1.

-Measurement of color difference-
The crushed pieces for regeneration obtained in the examples, the crushed pieces obtained in the comparative examples, and the virgin material of the reference example were put into an injection molding machine “NEX500” (manufactured by Nissei Plastic Industrial Co., Ltd.), and the cylinder temperature Injection molding was performed under the conditions of 235 ° C. and a mold temperature of 60 ° C. to produce a plate-like test piece (90 mm × 50 mm, 2 mm thickness).
Using a color difference meter “Macbeth Color-Eye 3100” (manufactured by Gredag Macbeth), the hue (L value, a value, b value) of the plate-like test piece was measured, and the hue in the reference example (virgin material) was determined. As a reference, the color difference ΔE of the plate-like test pieces in the examples and comparative examples was determined. The results are shown in Table 1.

−Measurement of foreign matter amount−
The regenerated crushed pieces obtained in the examples and the crushed pieces obtained in the comparative examples were melt kneaded at 260 ° C. without a filter in a lab plast mill (manufactured by Toyo Seiki Seisakusho, 2D25S). And granulated. Using a small heat press machine (AH-1TC, ASONE Co., Ltd.), a granulated crushed piece and a granulated crushed piece of a comparative example were used to produce a pancake as a recycled thermoplastic resin molded body. Separately, a pancake was prepared using the virgin material of the reference example. The amount of foreign matter in these pancakes was counted visually and microscopically. The foreign matter refers to a black spot observed on the pancake mainly due to deterioration of the surface or adhesion of foreign matter to the surface when the thermoplastic resin molded body is used (that is, before recovery). The amount of foreign matter existing around φ50 was counted for each size (0.3 mm or more, 0.1 mm or more and less than 0.3 mm, or less than 0.1 mm). The results are shown in Table 1.

Compared to Comparative Example 1, MVR was slightly lower in Example 1. This seems to be because the resin on the deteriorated surface portion is removed.
In Example 1, compared with Comparative Example 1, the color difference was dramatically improved, and the color difference from Reference Example 1 (virgin material) was only 0.3. If it is such a color change, it can be used without toning.
In Example 1, no foreign matter whose presence was discriminated by visual observation of 0.3 mm or more was found.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Main body apparatus 120a, 120b Front cover 136 Paper supply part 138 Paper discharge part 142 Process cartridge 150, 152 Case

Claims (3)

A surface deterioration process that deteriorates the surface by irradiating the thermoplastic resin molding with ultraviolet rays,
And the crushing process which crushes so that the average longest diameter may differ with the crushing piece (A) obtained from the part deteriorated by the said surface deterioration process, and the crushing piece (B) obtained from parts other than the said deteriorated part. A method for crushing a molded thermoplastic resin product.   Crushing of a thermoplastic resin molded body having a separation step of separating the crushed pieces (B) among the crushed pieces (A) and the crushed pieces (B) obtained by being crushed by the crushing method according to claim 1. A manufacturing method of a piece.   It has the reproduction | regeneration thermoplastic resin molding formation process which shape | molds and reproduces a thermoplastic resin molding using the crushing piece (B) manufactured by the manufacturing method of the crushing piece of the thermoplastic resin molding of Claim 2. A method for producing a recycled thermoplastic resin molded article.