JP2010083977A - Method for recycling plastics waste, plastic molding and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient method for recycling plastics waste by which plastic moldings having properties just for various uses can be obtained by material recycle and plastics waste to be subjected to thermal recycle is diminished. <P>SOLUTION: The method for recycling plastics waste includes a step of adding a rubber component and/or a flame retardant to plastics waste formed of modified polyphenylene ether resin which is an alloy resin of polyphenylene ether resin and polystyrenic resin, or a step of mixing the plastics waste with polystyrenic resin. A method for producing a plastic molding including the recycling method and a plastic molding obtained by the method are also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method for recycling plastic waste, a plastic molded body, and a method for manufacturing the same.

  In recent years, with the improvement of income levels in Japan, air conditioners (hereinafter also referred to as “air conditioners”) and television receivers (hereinafter referred to as “TV” in this specification). .), Home appliances such as refrigerators and washing machines, personal computers, information devices such as word processors, office equipment such as printers and fax machines, and various other furniture, stationery, toys, etc. Convenience in home life has been dramatically improved. As a result, the amount of discarded products such as these home appliances tends to increase year by year. Conventionally, the recycling of waste materials such as home appliances has often been performed through the iron scrap collection route.

  However, in recent years, the constituent materials of members of various products including home appliances have changed, the number of members made of metal such as iron has decreased, and the proportion of members made of plastic tends to increase. Plastics have a greater degree of design freedom than metals such as iron, and exhibit various properties that are difficult to achieve with metals by preparing components and using additives, and are lightweight and highly durable. This is because it has many advantages.

  Waste materials of various products such as home appliances in recent years have a complicated material composition of various components, the ratio of members made of valuable metals such as iron and copper is reduced, and the value is low. In the conventional processing method, the proportion of members made of plastic, which requires a lot of labor and cost, is increasing. Moreover, the conventional iron scrap recovery route is becoming difficult to deal with because it cannot be profitable even if such waste material is recycled.

  Many of these plastic parts are synthesized using crude fossil and other embedded fossil fuels as a basic raw material, and in recent years, there has been a strong demand for recycling these plastic parts from the viewpoint of effective resource utilization. It is coming.

  In addition, environmental destruction such as global warming and acid rain due to the release of carbon dioxide and sulfur oxides from combustion of buried fossil fuels such as crude oil, environmental pollution such as dioxin generation and scattering by incineration of plastics containing chlorine compounds, From the viewpoint of suppressing problems such as a shortage of landfill disposal sites due to an increase in waste containing bulky plastics, it is important and urgent to recycle waste of products equipped with these plastic components. It is becoming an issue. In the present specification, a member made of plastic is also referred to as “plastic member”. Further, in this specification, waste of plastic members is also referred to as “plastic waste”.

  In response to the above situation, the Home Appliance Recycling Law was enforced in April 2001. Under the Home Appliance Recycling Law, it is obliged to recycle four items of home appliances such as air conditioners, TVs, refrigerators and washing machines. A legal reference value of 50% or more of the washing machine is set.

  Then, following the enforcement of the Home Appliance Recycling Law, the collection of plastic waste materials is progressing. As a method for recycling the collected plastic waste, a so-called thermal recycling method using plastic waste as a fuel has been widely used. However, according to such a method, there is a problem such as generation of carbon dioxide gas due to combustion, so it cannot be said that the method is sufficiently in line with social demands.

  Therefore, for example, by manually dismantling the collected plastic waste material, separating the plastic members for each plastic system, and processing the plastic members again into product members or their raw materials for plastic waste materials to be used A recycling method has been proposed. Such a recycling method is called “material recycling” in contrast to the thermal recycling described above.

  The plastic member separated for each plastic system as described above can be relatively easily material-recycled by heating and melting and molding again. For this reason, research and development of a method for recycling plastic waste materials by material recycling has been conducted with great efforts in various fields with the aim of increasing the material recycling ratio of plastic waste materials.

  However, plastic waste, especially plastic waste used in household appliances and office equipment, is often used for a long time in a harsh environment, so its characteristics have already deteriorated when it is used. In addition to deterioration in appearance characteristics such as discoloration or fading, physical properties such as strength and flexibility are often lowered, resulting in poor durability. For this reason, plastic waste is not a substitute for plastic virgin materials used for plastic members having high required characteristics, and is often used as a raw material for plastic members having low required characteristics.

  At present, this kind of cascade recycling is the mainstream for material recycling of plastic waste. Therefore, the use of the plastic molded body recycled from the plastic waste material is limited, and there is a problem that a large amount of plastic waste material is thermally recycled. Here, in this specification, “virgin material” means an unused plastic. In addition, in this specification, the use of plastic waste material with reduced properties as a raw material for plastic members with low required properties, rather than as a substitute for virgin materials used for plastic members with high required properties, is referred to as “cascade recycling”. Shall be described.

  In order to overcome these problems, much research and development has been carried out to improve the properties of plastic moldings obtained by material recycling from plastic waste, and to achieve a level that can be used as plastic components with high required properties. ing. For example, many methods for maintaining characteristics by mixing a virgin material with plastic waste material (material recycling material) have been proposed (for example, Japanese Patent Laid-Open No. 2000-159900 (Patent Document 1) and Japanese Patent Laid-Open No. 2001-26719). No. (Patent Document 2), Japanese Patent Application Laid-Open No. 2003-160724 (Patent Document 3), etc.). However, in the material recycling methods as disclosed in Patent Documents 1 to 3, it is often necessary to mix a larger amount of virgin material than plastic waste, and it is difficult to say that it corresponds to a resource recycling society. .

Further, there has been proposed a molded body obtained by mixing a virgin material of a modified polyphenylene ether resin and a styrene resin recovered from the market and a manufacturing method thereof (for example, Japanese Patent Application Laid-Open No. 2003-49065 (Patent Document 4). JP, 2006-137808, A (patent documents 5), JP, 2006-297620, A (patent documents 6), etc.). However, in these proposals, the modified polyphenylene ether resin uses a virgin material, and in addition to the styrene resin recovered from the market, a styrene resin virgin material is also mixed. In many cases, it is hard to say that it corresponds to a resource recycling society.
JP 2000-159900 A JP 2001-26719 A JP 2003-160724 A JP 2003-49065 A JP 2006-137808 A JP 2006-297620 A

  As mentioned above, it is a recycling method by material recycling that uses plastic waste recovered from the market as the main raw material, and it has a wide range of uses for the plastic molded body, and has characteristics that can be used as a plastic member or its raw material. There is a demand for a method capable of obtaining a plastic molded body having the same. In addition, development of an efficient and low-cost method for recycling plastic waste is strongly desired. However, such a recycling method is not yet known.

  Recently, flat panel displays (FPD) such as liquid crystal displays, plasma displays, organic EL (Electro Luminescence) displays, inorganic EL displays, field emission displays (FED), and electronic paper have been around. For example, it has been widely used in various fields such as a television, a personal computer, a monitor, a video, a camera, a mobile phone, a car navigation, an information portable terminal, and a small game machine. The market size of FPD is increasing rapidly with the progress of the advanced information society in recent years due to its power saving, space saving and light weight. Along with this, the amount of disposal of these FPDs is expected to increase year by year, and in environmental activities such as recycling activities, there is an increasing demand for improving recyclability.

  However, these FPDs are relatively new products, and at present the amount of waste is relatively small, and recycling such as CRT televisions has not been put into practical use. The current situation is that the discarded FPD is crushed in a waste treatment facility and is landfilled or incinerated with shredder dust.

  In addition, flat TVs such as liquid crystal displays and plasma displays are being added as items to be applied under the Home Appliance Recycling Law in the near future. In this case, from the viewpoint of effective use of resources and improvement of the recycling rate, development of a recycling method for plastic waste materials used in the cabinet of the product is strongly desired. However, as described above, FPD products and flat-screen television products are relatively new products, and the recycling technology of cabinets that are parts thereof has not yet been established.

  For example, in a liquid crystal television cabinet, which is an example of a thin television, a modified polyphenylene ether resin (PPE + PS resin), which is an alloy material (alloy resin) of a polyphenylene ether resin and a polystyrene resin, is often used. This modified polyphenylene ether resin is one of materials having excellent durability, heat resistance and self-extinguishing properties and excellent mechanical properties. In addition, the modified polyphenylene ether resin used as the cabinet material for LCD TVs has a relatively high operating temperature. Therefore, it is difficult to prevent ignition, make it flame retardant for extinguishing, and plasticize it for improving moldability. For the purpose, phosphate ester flame retardants are mainly added.

  In addition to the modified polyphenylene ether resin, for example, polycarbonate resin and acrylonitrile-butadiene-styrene resin alloy resin (PC + ABS resin), acrylonitrile-butadiene-styrene resin (ABS resin), and high-impact polystyrene resin (HIPS resin) or the like is used. Among these, the PC + ABS resin is a polycarbonate resin, which is one of the main materials, having a carbonate ester structure and is prone to hydrolysis due to its chemical structure, especially in combination with a phosphate ester flame retardant. Because of its remarkable properties, it is a difficult material to improve the properties as well as the virgin material. In addition, many ABS resins and HIPS resins use brominated flame retardants as flame retardants. However, brominated flame retardants are very difficult to degrade depending on the grade, so they are very difficult materials when considering recycling. is there.

  On the other hand, the modified polyphenylene ether resin is durable even in wet heat environments, and the resin itself has very little deterioration. Therefore, when considering recycling, it is not necessary to mix virgin materials and the addition of rubber components and flame retardants. It is a material that is very suitable for recycling because it recovers its physical properties with little effort.

  However, nothing may be added as an additive such as the above-described rubber component or flame retardant, and it is desired that the modified polyphenylene ether resin has good compatibility and is easy to handle in the recycling process. .

  Based on the above-mentioned present situation, the problem to be solved by the present invention is that material recycling can provide a plastic molded body having characteristics corresponding to various uses, reducing the amount of plastic waste that is thermally recycled, and improving efficiency. Is to provide a method for recycling plastic waste.

  Furthermore, another subject of this invention is providing the plastic molding which has the characteristic according to various uses by material recycling from a plastic waste material.

  The present inventors pay attention to the durability of the modified polyphenylene ether resin, and without using the virgin material of the modified polyphenylene ether resin, only the addition of an additive such as a rubber component or a flame retardant is sufficient. It was confirmed that the properties recovered. Furthermore, we have found that rubber materials and flame retardants to be added can be recycled repeatedly by adding materials that are durable and easy to handle in the recycling process. Experiments on physical properties were conducted in order to develop a conversion method, and extensive studies were conducted. That is, the present invention is as follows.

  The plastic waste material recycling method of the present invention includes a step of adding a rubber component and / or a flame retardant to a plastic waste material formed of a modified polyphenylene ether resin that is an alloy resin of a polyphenylene ether resin and a polystyrene resin. (This method is hereinafter referred to as “first recycling method”).

  The rubber component in the first recycling method of the present invention is preferably a styrene-ethylene / butylene-styrene copolymer. In this case, the styrene-ethylene / butylene-styrene copolymer is more preferably in a weight ratio of 95 to 40% by weight of the ethylene / butylene component to 5 to 60% by weight of the styrene component.

  In the 1st recycling method of this invention, it is preferable to add the said rubber component in the ratio used as 1-10 weight part with respect to 100 weight part of plastic waste materials.

  The flame retardant in the first recycling method of the present invention is preferably an aromatic condensed phosphate ester flame retardant. In this case, the aromatic condensed phosphate ester flame retardant is preferably solid at room temperature.

  In the 1st recycling method of this invention, it is preferable to add the said flame retardant in the ratio used as 1-30 weight part with respect to 100 weight part of plastic waste materials.

  The present invention also provides a method for recycling plastic waste, including a step of mixing polystyrene resin with plastic waste formed of a modified polyphenylene ether resin, which is an alloy resin of a polyphenylene ether resin and a polystyrene resin. (Hereinafter, this method is referred to as “second recycling method”).

  In the second recycling method of the present invention, the polystyrene resin mixed with the alloy resin may be any one obtained from a virgin material or a plastic waste material.

  In the plastic waste material recycling method of the present invention, at least one of the alloy resin waste material and the polystyrene resin waste material is selected from the group consisting of home appliances, OA equipment, and electrical and electronic parts. More preferably, it is a part of a product on which a flat panel display is mounted. Further, the product on which the flat panel display is mounted is preferably at least one selected from a liquid crystal display, a plasma display, an organic EL display, an inorganic EL display, a field emission display, and electronic paper.

  The present invention also provides a method for producing a plastic molded body, including the above-described method for recycling plastic waste materials according to the present invention.

  The present invention further provides a plastic molded body produced by the above-described method for producing a plastic molded body of the present invention. The plastic molded body of the present invention is preferably used for a product that is material-recycled. In this case, the product that is material-recycled is at least one selected from the group consisting of home appliances, OA equipment, and electrical / electronic parts. Or a part of a product on which a flat panel display is mounted. Further, the product on which the flat panel display is mounted is more preferably at least one selected from a liquid crystal display, a plasma display, an organic EL display, an inorganic EL display, a field emission display, and electronic paper.

  According to the plastic waste material recycling method of the present invention, it is not necessary to add a virgin material of a modified polyphenylene ether resin, which can contribute to a reduction in the use of new fossil resources. Also, because material recycling is performed, unlike thermal recycling, it also leads to suppression of greenhouse gas generation. In addition, since material recycling can be repeated with the formulation of additives, stable recycling can be continued with little effort, and effective use of resources can be promoted. And by the manufacturing method of the plastic molding of this invention, material recycling which uses a plastic waste material as a main raw material can be performed, and the plastic molding which has the characteristic suitable for various uses can be provided.

  FIG. 1 is a flowchart showing a method for recycling plastic waste materials according to a preferred example of the present invention. Here, in the first recycling method of the present invention, a rubber component and a plastic waste material formed of a modified polyphenylene ether (PPE + PS) resin (hereinafter also referred to as “modified polyphenylene ether (PPE + PS) resin waste material”) are used. And / or a step of adding a flame retardant. The second recycling method of the present invention includes a step of mixing a polystyrene-based resin with a modified polyphenylene ether (PPE + PS) resin waste material. The polystyrene resin contained in the modified polyphenylene ether (PPE + PS) resin waste material in the present invention and the polystyrene resin added in the second recycling method are general-purpose polystyrene (GPPS) resin and / or impact resistance. Polystyrene (HIPS) resin is preferred.

  As described above, the plastic waste material recycling method of the present invention is applied to the plastic waste material formed of the modified polyphenylene ether (PPE + PS) resin according to the first recycling method and the second recycling method described above. , A rubber component and / or a flame retardant (first recycling method) or a step of mixing a polystyrene resin (second recycling method) (in the example shown in FIG. 1, a mixing step (step S8)) ) At least. In FIG. 1, before this mixing step (step S8), a modified polyphenylene ether (PPE + PS) resin waste recovery step (step S1), a foreign material removal step (step S2), and a crushing step (step S3) And a cleaning process (step S4), a drying process (step S5), a modified polyphenylene ether (PPE + PS) resin waste lot inspection process (step S6), and a characteristic improvement prescription determination process (step S7) in this order. In addition, after the mixing process (step S8), a pellet manufacturing process (step S9) and a molded body manufacturing process (step S10) are shown. For example, when the above plastic waste material is obtained from a waste liquid crystal television cabinet, when it is subjected to advanced recycling such as recycling to the same member again, this plastic waste material is required to have high characteristics equivalent to the virgin material of the same material. Therefore, it is preferable that the recycling method of the present invention includes each step as in the example shown in FIG. Hereinafter, taking the case shown in FIG. 1 as an example, the plastic waste material recycling method of the present invention will be described in detail.

  In the example shown in FIG. 1, first, in the modified polyphenylene ether (PPE + PS) resin waste material recovery step (step S1), the waste material is recovered. The waste material is preferably at least one selected from the group consisting of home appliances, OA equipment, and electrical and electronic parts. Moreover, it can also be applied to plastic waste materials collected from products equipped with flat panel displays (such as liquid crystal displays and plasma displays) that have recently been on an expanding trend, and can be efficiently recycled. Home appliances include products selected from the group consisting of air conditioners, televisions, refrigerators, washing machines, and the like, and particularly include members made of plastics that use flame retardants used in liquid crystal televisions, copiers, and the like. Further, the product on which the flat panel display is mounted is preferably at least one selected from a liquid crystal display, a plasma display, an organic EL display, an inorganic EL display, a field emission display, and electronic paper.

  The waste material is often used as a cabinet for a liquid crystal television. In this case, since the cabinet is usually fixed with a plurality of screws, the housing can be removed by removing the screws using a screwdriver.

  Next, in the foreign material removal process (step S2), a material different from the cabinet (hereinafter referred to as "different material") is removed. Examples of the different material include a seal attached to a cabinet, a logo batch, a vibration preventing tape, a cord binding band, and the like. The front cabinet is often painted, but the coating is also made of a different material. It is preferable to remove these foreign materials because they are a cause of deterioration in physical properties. The method for removing foreign materials from the cabinet is not particularly limited, such as mechanical methods such as cutting and polishing, and removal using chemicals, and conventionally known methods can be used as appropriate.

  In the subsequent crushing step (step S3), the cabinet is crushed to about 10 mm). Thereafter, in the cleaning step (step S4), the cabinet crushed material is washed to remove adhered dirt, dust, foreign matter, and the like. Examples of the method for washing the crushed cabinet include a dry method for removing foreign matters by rubbing crushed resins and a wet method such as water washing, but the method is not particularly limited. Conventionally known methods can be appropriately used.

  Next, in the drying step (step S5), the washed cabinet crushed material is dried. The modified polyphenylene ether (PPE + PS) resin is resistant to a moist heat environment, and even if it contains moisture, it hardly causes deterioration of physical properties, but it is preferable to perform drying in consideration of the appearance finish. The drying conditions are, for example, about 3 to 5 hours at 80 ° C., but are not particularly limited. Moreover, also about drying equipment, although a thermostat, a dehumidification dryer, a hot air dryer etc. are mentioned, it does not specifically limit also about this.

  In the subsequent lot inspection step (step S6), a small amount of the modified polyphenylene ether (PPE + PS) resin waste material that has undergone the drying step (step S5) is extracted and subjected to lot inspection. Thereby, it becomes possible to grasp the characteristics of the waste material and to formulate a characteristic improvement prescription. Examples of inspection items include mechanical properties such as tensile strength, tensile elongation, bending strength, flexural modulus, impact strength, flow characteristics, and flame retardancy. Modified polyphenylene ether (PPE + PS) resin is less prone to deterioration of the resin itself, so there is little degradation in mechanical properties of waste materials, but there is a possibility of deterioration of additives such as rubber components and flame retardants. It is preferable to grasp the characteristics comprehensively.

  Next, in the characteristic improvement prescription determination step (step S7), the characteristic improvement prescription is determined according to the inspection result in the lot inspection step (step S6). Here, in the case of the 1st recycling method mentioned above, a rubber component and / or a flame retardant are used as an additive added in a characteristic improvement prescription.

  The rubber component used in the first recycling method is preferably a styrene-ethylene-butylene-styrene copolymer obtained by adding hydrogen to a styrene-butadiene copolymer. In the copolymer of styrene and butadiene, the double bond portion of butadiene is deteriorated by long-term use of the product, and the impact characteristic which is the characteristic of rubber is lowered. On the other hand, in the case of styrene-ethylene / butylene-styrene copolymer, the double bond part is saturated by hydrogenation, so it is a rubber component with excellent heat resistance and weather resistance, and repeated material recycling is considered. This is also effective. Examples of such rubber components include Tuftec H1272 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1221 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1062 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1043 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1052 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1053 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1041 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1051 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1031 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec H1141 (Asahi Kasei Chemicals Corporation), Tuftec M1911 (Asahi Kasei Chemicals Corporation), Tuftec M1913 (Asahi Kasei Chemicals Corporation), Tough MUC43 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec P1000 (manufactured by Asahi Kasei Chemicals Corporation), Tuftec P200 (manufactured by Asahi Kasei Chemicals Corporation), etc., but these are only examples and are limited to these. is not.

  In addition, as the styrene-ethylene / butylene-styrene copolymer having a good compatibility with the modified polyphenylene ether (PPE + PS) resin having a track record as a cabinet material in the market, the styrene-ethylene / butylene-styrene copolymer is a styrene component. The weight ratio is preferably 95 to 40% by weight of ethylene / butylene component with respect to 5 to 60% by weight. When the styrene component exceeds 60% by weight and the ethylene / butylene component is less than 40% by weight, the compatibility with the polystyrene resin which is one of the main materials of the modified polyphenylene ether (PPE + PS) resin is good, but relatively Since the ratio of ethylene / butylene component, which is a rubber component, decreases, desired impact characteristics may not be obtained. On the other hand, when the styrene component is less than 5% by weight and the ethylene / butylene component ratio exceeds 95% by weight, the rubber component is excessive in this case, and the possibility of lowering the rigidity and the styrene component is too small. There is a possibility that the compatibility with a polystyrene resin which is one of the materials is deteriorated.

  In consideration of the overall physical properties such as rigidity, impact characteristics and compatibility, the weight ratio of the styrene-ethylene / butylene-styrene copolymer is approximately 42% by weight of the styrene component, and the ethylene / butylene component is approximately More preferably it is 58% by weight.

  In addition, the above rubber component (preferably styrene-ethylene / butylene-styrene copolymer) is added in the ratio of 1 to 10 parts by weight with respect to 100 parts by weight of the modified polyphenylene ether (PPE + PS) resin waste. It is preferable to do. When the addition amount of the rubber component is less than 1 part by weight with respect to 100 parts by weight of the waste material, the effect of improving the impact characteristics is small, and when the addition amount of the rubber component exceeds 10 parts by weight with respect to 100 parts by weight of the waste material, The rigidity tends to decrease and is not economically effective. The rubber component (preferably styrene-ethylene / butylene-styrene copolymer) is used in a ratio of 1 to 3 parts by weight with respect to 100 parts by weight of the waste material from a comprehensive viewpoint such as rigidity, impact characteristics, and economic aspect. It is preferable to add to.

  As the flame retardant used in the first recycling method, an aromatic condensed phosphate ester flame retardant is preferable. Here, the flame retardant added from the original (virgin material) to the modified polyphenylene ether (PPE + PS) resin waste material, which has a proven track record as a cabinet material in the market, is a liquid state at normal temperature among aromatic condensed phosphate esters. Most are. Examples of the flame retardant originally added from (virgin material) include resorcinol bisdiphenyl phosphate and bisphenol A bisdiphenyl phosphate. Specifically, CR-733S (made by Daihachi Chemical Industry Co., Ltd.) and CR-741 (made by Daihachi Chemical Industry Co., Ltd.) can be mentioned. These are superior in heat resistance and hydrolysis resistance compared to triphenyl phosphate and trixylenyl phosphate, which have been often used as phosphorus flame retardants in the past, but they are highly viscous liquids at room temperature. And the problem of being difficult to handle in the addition (mixing) process remains. In addition, when material recycling is repeatedly taken into account, durability such as heat resistance and hydrolysis resistance is not necessarily sufficient.

  Here, considering the handling in the recycling process, the flame retardant used in the first recycling method is preferably an aromatic condensed phosphate ester flame retardant fixed at room temperature. Examples of the aromatic condensed phosphate ester flame retardant fixed at room temperature include 1,3-phenylene-teslakis (2,6-dimethylphenyl) phosphate, 1,4-phenylene-tetrakis (2,6- Dimethylphenyl) phosphate, 4,4′-biphenylene-teslakis [2,6-dimethylphenyl] phosphate, and the like. Specifically, PX-200 (made by Daihachi Chemical Industry Co., Ltd.), PX-201 (made by Daihachi Chemical Industry Co., Ltd.), PX-202 (made by Daihachi Chemical Industry Co., Ltd.) and the like can be mentioned.

  Further, when considering durability such as hydrolysis resistance, it is particularly preferable to use 4,4'-biphenylene-teslakis [2,6-dimethylphenyl] phosphate. However, this is only an example and is not particularly limited.

  Moreover, it is preferable to add the said rubber component to the flame retardant mentioned above in the ratio used as 1-30 weight part with respect to 100 weight part of said modified polyphenylene ether (PPE + PS) resin waste materials. This is because when the amount of flame retardant added is less than 1 part by weight with respect to 100 parts by weight of the waste material, the effect of improving the flame retardant properties may be small, and the amount of flame retardant added is 100 parts by weight of waste material. On the other hand, if it exceeds 30 parts by weight, the plasticity tends to be excessive and the rigidity and heat resistance tend to decrease, and it is not economically effective.

  In the second recycling method described above, a polystyrene resin is mixed with the modified polyphenylene ether (PPE + PS) resin waste material instead of the rubber component and the flame retardant. The modified polyphenylene ether (PPE + PS) resin is completely compatible with the polyphenylene resin and the polystyrene resin, and is very compatible with the polystyrene resin. Until now, there have been many examples of mixing of modified polyphenylene ether (PPE + PS) resin virgin materials and polystyrene resins. Thus, examples of mixing modified polyphenylene ether (PPE + PS) resin waste materials and polystyrene resins have been found so far. There wasn't.

  In this case, the polystyrene resin may be a virgin material or may be obtained from a plastic waste material, but from the viewpoint of effective use of resources, the polystyrene resin is preferably a waste material. Polystyrene resins have very good moldability and appearance characteristics, and are used in various product housings. Therefore, they are widely used as waste materials. For example, they are often used in home appliances, OA equipment, and electrical and electronic parts. It has been. In addition, FPD products, which have recently been on an expanding trend, are often used in housings of liquid crystal televisions and plasma televisions, and polystyrene resin waste materials can be sufficiently recovered from these housings.

  Here, the polystyrene-based resin may be mixed in any proportion with respect to 100 parts by weight of the modified polyphenylene ether (PPE + PS) resin waste material. Since the polyphenylene ether component and the polystyrene-based component are compatible with each other at any ratio, it is not necessary to specify the mixing ratio. For example, if heat resistance is more important, mixing may be performed so as to increase the proportion of the polyphenylene ether component. For example, if importance is attached to the moldability of the resin, mixing may be performed so as to increase the proportion of the polystyrene component.

  Next, in the mixing step (step S8), based on the property improvement prescription determined in the property improvement prescription determination step (step S7), the modified polyphenylene ether (PPE + PS) resin waste material is converted into a rubber component and / or a flame retardant (first). In the case of the first recycling method), a polystyrene resin (in the case of the second recycling method) is mixed.

  In the subsequent pellet manufacturing process (step S9), the modified polyphenylene ether (PPE + PS) resin waste material mixed in the above-described mixing process (step S8), a rubber component and / or a flame retardant (in the case of the first recycling method), A mixture with a polystyrene resin (in the case of the second recycling method) is heated and melted to produce a pellet-shaped resin material for molding. Pellet manufacture can be performed with an extruder. The extruder is not particularly limited, and for example, a single screw extruder, a twin screw extruder, or a multi-screw extruder can be preferably used.

  When the mixture obtained in the mixing step (step S8) is formed into pellets and recycled, it may be granulated by a method such as sheet cut, strand cut, hot air cut, underwater cut after extrusion. it can. Further, when molding into a specific shape later by injection molding, the underwater cut method is particularly preferable in that the resin raw material can be supplied smoothly and processed in large quantities.

  The particle size of the pellet is preferably 1 mm or more, and more preferably 2 mm or more. The particle size of the pellet is preferably 8 mm or less, and more preferably 5 mm or less. When the particle size of the pellet is less than 1 mm, the workability is likely to be lowered because it is floating, and when the particle size of the pellet exceeds 8 mm, it is not sufficiently melted in the cylinder of the molding machine, so that uniform kneading becomes difficult. Prone.

  The shape of the molding resin raw material described above is not limited to a pellet shape, and may be a sheet shape, a film shape, a pipe shape, or the like. Therefore, it can be determined as appropriate from the type of the extruder, the mode of use or the required characteristics. In addition, the above-described molding resin raw material may include additives such as a heat stabilizer, a light stabilizer, an antistatic agent, a lubricant, a filler, a copper damage inhibitor, an antibacterial agent, and a colorant, if necessary. Can be added in an amount that does not harm the amount.

  In addition, in order to simplify the manufacturing process of the plastic member, it is possible to directly produce the plastic member by directly putting the crushed plastic into the injection molding machine without forming it into a pellet shape. When mixing a flame retardant etc., it is preferable to perform pellet manufacture by an extrusion process, since the extrusion process can blend uniformly.

  Next, in the molded body manufacturing process (step S10), the pellet-shaped resin raw material manufactured in the above-described pellet manufacturing process (step S9) is heated and melted with an injection molding machine to manufacture a plastic molded body. Although it does not specifically limit as an injection molding machine, For example, a screw in-line type injection molding machine or a plunger type injection molding machine etc. are mentioned.

  The present invention also provides a method for producing a plastic molded body including the above-described method for recycling plastic waste materials according to the present invention. Processes other than the above-described method for recycling plastic waste of the present invention in the method for producing a plastic molded body of the present invention can be combined with known processes as appropriate, and are not particularly limited. Furthermore, the present invention also provides a plastic molded body produced by the above-described method for producing a plastic molded body of the present invention.

  The plastic molded article of the present invention is preferably used for a product that is material-recycled. In this case, the product that is material-recycled is selected from the group consisting of home appliances, OA equipment, and electrical and electronic parts. It is preferable that at least one of the above. The material recycled product may be a part of a product on which a flat panel display is mounted. In this case, the product on which the flat panel display is mounted is a liquid crystal display, a plasma display, an organic EL display, or an inorganic EL display. It is preferable that at least one selected from a field emission display and electronic paper.

  Hereinafter, although an example of an experiment is given and the present invention is explained in detail, the present invention is not limited to these.

<Experimental Example 1: Examination of Component Ratio of Styrene-Ethylene / Butylene-Styrene Copolymer>
Currently, the modified polyphenylene ether (PPE + PS) resin, which is an alloy resin composed of a polyphenylene ether resin and a styrene resin, used in a cabinet material for liquid crystal televisions, etc., has hardly passed the time (one year). degree). Therefore, since it is expected that there is almost no deterioration over time due to user use, the present inventors artificially produced plastic waste materials by the following procedure.

  First, virgin pellets of modified polyphenylene ether resin (PPE + PS), which is an alloy resin composed of polyphenylene ether resin and polystyrene resin (Zylon TV08J (manufactured by Asahi Kasei Chemicals Corporation): hereinafter referred to as “PPE + PS virgin material”), are prepared at 80 ° C. 3 hours, after drying with a dehumidifying dryer (Matsui Seisakusho Co., Ltd.), with a 10-ton injection molding machine (Nissei Plastic Industries Co., Ltd.), a molding temperature of 260 ° C., a mold temperature of 60 ° C., and cooling A molded body was produced under the injection molding conditions of 30 seconds.

  Next, this molded body was put into a constant temperature and humidity chamber (LH-113, manufactured by ESPEC Corp.) set at a room temperature of 80 ° C. and a humidity of 95% RH for 800 hours to promote deterioration. This was used as a pseudo plastic waste material (hereinafter referred to as “PPE + PS waste material”) and crushed by a crusher.

  Next, several types of styrene-ethylene butylene-styrene copolymers having different weight ratios of styrene and ethylene / butylene were prepared. Specifically, (1) Tuftec H1052 (made by Asahi Kasei Chemicals Corporation) (styrene / ethylene butylene weight ratio = 20/80), (2) Tuftec H1041 (made by Asahi Kasei Chemicals Corporation) (styrene / ethylene butylene weight) Ratio = 30/70), (3) Tuftec H1051 (manufactured by Asahi Kasei Chemicals Corporation) (styrene / ethylene / butylene weight ratio = 42/58), (4) Tuftec H1043 (manufactured by Asahi Kasei Chemicals Corporation) (styrene / ethylene. Four types of butylene weight ratio = 67/33) were prepared.

  Next, 1 kg of each crushed PPE + PS waste material was put in a bag, and 5 bags were prepared. This contains the above-mentioned styrene-ethylene-butylene-styrene copolymer ((1) Tuftec H1052, (2) Tuftec H1041, (3) Tuftec H1051, (4) Tuftec H1043, and 1 kg of crushed PPE + PS waste material. 3 parts by weight (30 g) was added to each bag, and mixed so as to be uniformly mixed with the crushed PPE + PS waste material (Examples 1 to 4). (Comparative Example 1).

  Next, for these five samples, using a biaxial melt kneading extruder (manufactured by Technobel Co., Ltd.) having a screw diameter of 25 mm and L / D = 26, heat melting and kneading at a set temperature of 260 ° C. and extrusion molding, Cutting was performed using a pelletizer to obtain a pellet-shaped resin material for molding.

  Finally, the above 10-ton injection molding machine (manufactured by Nissei Plastic Industry Co., Ltd.) is remolded under injection molding conditions of a molding temperature of 260 ° C., a mold temperature of 60 ° C. and a cooling time of 30 seconds, and is compliant with ASTM. A test specimen for measurement was prepared. In addition, a test piece for measuring physical properties having a thickness of 3 mm was also prepared for measuring the surface impact strength. Here, the above-mentioned test piece was produced also about PPE + PS virgin material, and it was set as the comparative sample (comparative example 2). And using each of these test pieces, the tensile strength, elongation, bending strength, bending elastic modulus, Izod impact strength, and surface impact strength described later were measured.

<Method for measuring physical properties>
(1) Tensile strength (MPa) and elongation (%)
The tensile strength at break and the elongation at break were measured according to JIS K7113. In addition, “tensile strength” and “elongation” are materials that are tensioned at a constant speed, and the relationship between stress and strain is obtained. The stretched material first undergoes elastic deformation, then plastic deformation, When the maximum strength is reached and the yield point is exceeded, necking occurs and breaks. The place where the stress is greatest (maximum point stress) is called “tensile strength”, and the strain at break (elongation at break) is called “elongation”.

(2) Flexural strength (MPa) and flexural modulus (MPa)
Measurements were made in accordance with JIS K7203. “Bending strength” and “flexural modulus” are obtained by applying a stress to the center of a test piece supported at two points to obtain a relationship between stress and strain. The place where the stress is greatest is called “bending strength”, and the slope of the stress-strain curve is called “flexural modulus”.

(3) Notched Izod impact strength (KJ / m ² )
The measurement was performed in accordance with JIS K7110.

(4) Surface impact strength (cm)
The measurement was performed in accordance with JIS K7211.

  The physical property measurement results of Experimental Example 1 are shown in Table 1. From Table 1, it was found that PPE + PS waste material to which Tuftec H1051 (styrene / ethylene butylene weight ratio = 42/58) was added had the best balance of physical properties and was optimal.

<Experimental example 2: Examination of addition amount of styrene-ethylene / butylene-styrene copolymer>
Next, the PPE + PS waste material used in Experimental Example 1 and a styrene-ethylene-butylene-styrene copolymer (Tuftec H1051, manufactured by Asahi Kasei Chemicals Corporation) were prepared, and the addition amount thereof was examined. The specific method is shown below.

  First, 1 kg of crushed PPE + PS waste material was put in a bag, and 5 bags were prepared. Four types of H1051 are prepared: (1) 1 part by weight (10 g), (2) 3 parts by weight (30 g), (3) 5 parts by weight (50 g), and (4) 10 parts by weight (100 g). In the bag containing 1 kg of the PPE + PS waste material, one kind was added to each bag and mixed so as to be uniformly mixed with the crushed material of PPE + PS waste materials (Examples 5 to 8). One bag to which nothing was added was used as a comparative sample (Comparative Example 3). Thereafter, the same experiment as in Experimental Example 1 was performed.

  The physical property measurement results of Experimental Example 2 are shown in Table 2. As a result, it was found that the addition amount of the styrene-ethylene / butylene-styrene copolymer is 1 to 3 parts by weight as the balance of physical properties. Further, when the addition amount was 5 parts by weight and 10 parts by weight, the decrease in the flexural modulus was increasing.

<Experimental example 3: Examination of mixing work of flame retardant>
Next, 1 kg of each crushed PPE + PS waste material used in Experimental Example 1 was put in a bag, and two bags were prepared. PX-202 (made by Daihachi Chemical Industry Co., Ltd.) (solid at room temperature) and CR-741 (made by Daihachi Chemical Industry Co., Ltd.) (liquid at room temperature) are prepared as aromatic condensed phosphate ester flame retardants. Then, 3 parts by weight (30 g) of each type was added to each bag containing 1 kg of the PPE + PS waste material, the bag was sealed, and the mixture was stirred and mixed for 5 minutes with Platec Tumbler (SKD-15). . As a result, since PX-202 is a solid (powder) at room temperature, it was uniformly mixed with the crushed material of PPE + PS waste, but CR-741 may be a highly viscous liquid and not uniformly mixed. Many places were seen.

<Experimental Example 4: Evaluation of hydrolysis resistance of flame retardant>
Next, using the PPE + PS virgin material used in Experimental Example 1, the hydrolysis resistance of the flame retardant was evaluated. As the flame retardant, PX-202 (manufactured by Daihachi Chemical Industry Co., Ltd.) and CR-741 (manufactured by Daihachi Chemical Industry Co., Ltd.) were used. Details of the experimental method are shown below.

  First, 1 kg of PPE + PS virgin material was put in a bag, and two bags were prepared. Then, (1) PX-202, (2) CR-741 is added to each bag containing 1 kg of PPE + PS virgin material, 10 parts by weight (100 g) per bag until it is evenly mixed by hand. Mixed (Examples 9, 10). These two types of samples were heated and melt-kneaded at a set temperature of 260 ° C. using the biaxial melt-kneading extruder (manufactured by Technobel Co., Ltd.) used in Experimental Example 1, and extruded and cut using a pelletizer. Then, 2 samples of pelletized resin raw material for molding were obtained. The two samples were subjected to a pressure cooker test at 121 ° C., 100% RH, 2 atm, and 6 hours. For the pressure cooker test, EHS-410M (manufactured by ESPEC Corporation) was used. After completion of the pressure cooker test, a sample was taken out and the melt flow rate (MFR) was measured according to JIS K7210 (melt flow tester, manufactured by CEAST). As measurement conditions, the resin melting temperature was 250 ° C., and the load weight was fixed at 5 kg. The results are shown in Table 3. As a result, the sample to which PX-202 was added had a lower MFR than that of CR-741. This is because PX-202 is more difficult to hydrolyze than CR-741 and is durable.

  The method for recycling plastic waste materials according to the present invention is not limited to the method for recycling plastic waste materials collected from household electrical appliances, OA equipment, and electrical / electronic components, and comprises a polyphenylene ether resin and a styrene resin. Any product can be suitably applied as long as the product includes a member composed of a modified polyphenylene ether (PPE + PS) resin that is an alloy resin.

  The embodiments and experimental examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the method for recycling plastic waste material of the present invention, plastic waste material formed from a modified polyphenylene ether resin, which is an alloy resin of a polyphenylene ether resin and a polystyrene resin, can be efficiently recycled. Accordingly, it is possible to obtain a plastic molded body having characteristics corresponding to the above, and it is possible to reduce plastic waste materials that are thermally recycled.

  In addition, according to the method for recycling plastic waste material of the present invention, it is not necessary to add a virgin material of a modified polyphenylene ether resin, which can contribute to a reduction in the use of new fossil resources. Also, because material recycling is performed, unlike thermal recycling, it also leads to suppression of greenhouse gas generation. In addition, since material recycling can be repeated with the formulation of additives, stable recycling can be continued with little effort, and effective use of resources can be promoted. And by the manufacturing method of the plastic molding of this invention, material recycling which uses a plastic waste material as a main raw material can be performed, and the plastic molding which has the characteristic suitable for various uses can be provided.

  And by the manufacturing method of the plastic molding of this invention, material recycling which uses a plastic waste material as a main raw material can be performed, and the plastic molding which has the characteristic suitable for various uses can be provided.

It is a flowchart which shows a preferable example of the recycling method of the plastic waste material of this invention.

Claims (19)

  A method for recycling plastic waste, comprising a step of adding a rubber component and / or a flame retardant to plastic waste formed of a modified polyphenylene ether resin, which is an alloy resin of a polyphenylene ether resin and a polystyrene resin.   The method for recycling plastic waste material according to claim 1, wherein the rubber component is a styrene-ethylene-butylene-styrene copolymer.   The method for recycling plastic waste materials according to claim 2, wherein the styrene-ethylene / butylene-styrene copolymer is in a weight ratio of 95 to 40% by weight of ethylene / butylene component to 5 to 60% by weight of styrene component. .   The plastic waste material recycling method according to any one of claims 1 to 3, wherein the rubber component is added at a ratio of 1 to 10 parts by weight with respect to 100 parts by weight of the plastic waste material.   The method for recycling plastic waste materials according to claim 1, wherein the flame retardant is an aromatic condensed phosphate ester flame retardant.   The method for recycling plastic waste materials according to claim 5, wherein the aromatic condensed phosphate ester flame retardant is in a solid state at room temperature.   The method for recycling plastic waste material according to claim 1, wherein the flame retardant is added at a ratio of 1 to 30 parts by weight with respect to 100 parts by weight of plastic waste material.   A method for recycling plastic waste, including a step of mixing a polystyrene resin with a plastic waste made of a modified polyphenylene ether resin, which is an alloy resin of a polyphenylene ether resin and a polystyrene resin.   The method for recycling plastic waste material according to claim 8, wherein the polystyrene resin mixed with the alloy resin is a virgin material.   The method for recycling plastic waste material according to claim 8, wherein the polystyrene resin mixed with the alloy resin is obtained from plastic waste material.   The waste material of the said alloy resin and at least any one of the waste material of a polystyrene-type resin are at least any one chosen from the group which consists of household appliances, OA apparatus, and an electrical and electronic component, Any of Claims 1-8, 10 Recycling method of plastic waste materials described in Crab.   The plastic waste material recycling method according to claim 1, wherein at least one of the alloy resin waste material and the polystyrene resin waste material is a part of a product on which a flat panel display is mounted. .   The recycled plastic waste according to claim 12, wherein the product on which the flat panel display is mounted is at least one selected from a liquid crystal display, a plasma display, an organic EL display, an inorganic EL display, a field emission display, and electronic paper. Recycling method.   The manufacturing method of a plastic molding including the recycling method of the plastic waste material in any one of Claims 1-13.   The plastic molding manufactured by the manufacturing method of the plastic molding of Claim 14.   The plastic molded body according to claim 15, which is used for a product to be recycled.   The plastic molded body according to claim 16, wherein the product to be material-recycled is at least one selected from the group consisting of home appliances, OA equipment, and electrical and electronic parts.   The plastic molded body according to claim 16, wherein the product to be material-recycled is a part of a product on which a flat panel display is mounted.   The plastic molded article according to claim 18, wherein the product on which the flat panel display is mounted is at least one selected from a liquid crystal display, a plasma display, an organic EL display, an inorganic EL display, a field emission display, and electronic paper.

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