JP2007326940A - Thermoplastic resin composition, thermoplastic resin molded product and method for producing thermoplastic resin molded product and method for reconverting thermoplastic resin into resource - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition having various characteristics sufficiently withstanding even use over a long period and comprising a thermoplastic resin component derived from biomass, to provide a molded product and a method for producing the molded product and to provide a method for reconverting a thermoplastic resin comprising the thermoplastic resin component derived from the biomass into resources. <P>SOLUTION: The thermoplastic resin composition comprises a thermoplastic resin component (A) derived from a fossil resource, the thermoplastic resin component (B) derived from the biomass and a hydrolysis inhibitor (C). The molded product and the method for producing the molded product are provided. The method for reconverting the thermoplastic resin into the resources comprises adding the hydrolysis inhibitor to the thermoplastic resin recovered from wastes, heating and melting the resultant mixture and affording the thermoplastic resin molded product. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition and a thermoplastic resin molded body, and more specifically, a thermoplastic resin composition and a thermoplastic resin molded body containing a biomass-derived thermoplastic resin component and a fossil resource-derived thermoplastic resin component. About. The present invention also relates to a method for producing a thermoplastic resin molded body. Furthermore, the present invention relates to a method for recycling a thermoplastic resin, and more particularly to a method for recycling a thermoplastic resin containing a biomass-derived thermoplastic resin component.

  In order to build a recycling-oriented society, there is a need to switch from the conventional mass production, mass consumption, and mass disposal paradigm to a new production paradigm that takes circulation into account. In particular, in a new production paradigm that takes circulation into account, it is necessary to use renewable resources and to make resources more friendly to the earth.

  From the viewpoint of renewable resources, environmentally friendly resources derived from biomass have attracted attention. Among biomass-derived resources, especially plant-derived resources are renewable, and even if incinerated, carbon dioxide is absorbed during the plant growth process, so the concentration of carbon dioxide in the environment is said not to increase. It is an environmentally friendly material. In recent years, in order to expand and appropriately circulate the use of plant-derived resources, which are environmentally friendly materials, plant-based resource utilization and recycling technologies are being developed in various fields. Further expansion and establishment of appropriate recycling methods are important issues.

  Various efforts have been made to circulate resources derived from biomass appropriately. For example, a method for composting using biodegradability, which is one of the characteristics of biomass-derived resources, has been proposed.

  For example, Patent Document 1 proposes a method for treating organic waste having a fermentation decomposition process of organic waste and a process of disintegrating a biodegradable plastic product. However, in such composting, air is required to ferment organic waste, and an apparatus for supplying air to the treatment tank is required. Therefore, the organic waste processing method has a problem that the processing tank and the apparatus for supplying air are expensive. Moreover, there is a possibility that power is applied to the device and the environmental load increases.

  Patent Document 2 discloses an energy recovery method including a step of bringing a polylactic acid biodegradable plastic into contact with a methanogen in the presence of water and anaerobic fermentation, and a step of generating biogas containing methane. Yes. However, such an energy recovery method has a problem that it takes 10 days or more to recover the energy by fermentation. In addition, a solid-liquid separation device is used to recover the solid matter remaining in the fermenter after energy recovery, and there is a problem that costs increase.

  In this way, regarding the recycling of biomass-derived thermoplastic resins, composting and energy recovery have been carried out taking advantage of their biodegradability characteristics, but recycling of thermoplastic resins derived from fossil resources has been carried out. The conventional “material recycling” is not carried out as a conversion method. This is because many of the biomass-derived thermoplastic resins are biodegradable and are not suitable for long-term use. Here, “material recycling” of the thermoplastic resin means separating the members made of the thermoplastic resin for each thermoplastic resin system from the recovered thermoplastic resin waste material by a method such as manual disassembly, It means a recycling method in which a member made of such a thermoplastic resin is processed again into a product member or its raw material.

In order to expand the reuse of thermoplastic resins derived from biomass, there is a need for a completely new recycling method that takes into account the resource circulation while exhibiting performance that can withstand long-term use.
JP 2001-269652 A JP 2005-206735 A

  The present invention has been made in view of such a situation, and the object of the present invention is thermoplasticity including a biomass-derived thermoplastic resin component having various characteristics that can sufficiently withstand long-term use. It is providing a resin composition and its molded object.

  Moreover, another subject of this invention is providing the efficient manufacturing method of the said thermoplastic resin molding.

  Furthermore, another subject of this invention is providing the efficient recycling method of the thermoplastic resin containing the thermoplastic resin component derived from biomass.

  As a result of intensive studies, the inventors have found that a hydrolysis inhibitor may be added so that a thermoplastic resin containing a biomass-derived thermoplastic resin component can withstand long-term use. In addition, it can withstand long-term use by adding a hydrolysis inhibitor when further recycling the thermoplastic resin containing biomass-derived thermoplastic resin components. It was found that there was almost no deterioration in physical properties. The present invention is based on these findings.

  The thermoplastic resin composition of the present invention comprises a thermoplastic resin component (A) derived from fossil resources, a thermoplastic resin component (B) derived from biomass, and a hydrolysis inhibitor (C).

  The thermoplastic resin component (A) preferably contains a polyolefin-based thermoplastic resin as a main component.

  Here, the thermoplastic resin component (B) preferably contains a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid.

  The hydrolysis inhibitor (C) is a carbodiimide compound and is preferably contained in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the thermoplastic resin component (B).

  The thermoplastic resin composition of the present invention may further contain a modifier and / or an antioxidant.

  Here, the modifier preferably contains a block copolymer obtained by bonding a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid and an aliphatic polyester.

  Moreover, it is preferable that a modifier contains the block copolymer which contains a polyolefin-type resin component and a polystyrene-type resin component as a structural unit.

  Moreover, it is preferable that a modifier contains the modified polymer which contains the olefin containing a carboxylic acid group or its derivative group as a structural unit.

  Further, the antioxidant includes a phenolic antioxidant and a phosphorus antioxidant, and the phenolic antioxidant and the phosphorus antioxidant are each 0.01 parts in 100 parts by weight of the thermoplastic resin composition. It is preferable that -5 weight part is contained.

  Furthermore, the thermoplastic resin component (A) and / or the thermoplastic resin component (B) is preferably a thermoplastic resin recovered from waste.

The present invention also provides a thermoplastic resin molded article comprising the thermoplastic resin composition.
The thermoplastic resin molding of the present invention may have a pellet shape.

  The thermoplastic resin molded article of the present invention can be used in any of an air conditioner, a television, a refrigerator, and a washing machine.

  The present invention also provides a method for producing a thermoplastic resin molded article, which is characterized by molding the thermoplastic resin composition into a specific shape.

  Furthermore, the present invention has at least a resin recovery step for separating and recovering a thermoplastic resin from waste, and a molded body manufacturing step for manufacturing a thermoplastic resin molded body from the separated and recovered thermoplastic resin. The manufacturing process includes a mixing step of adding and mixing a hydrolysis inhibitor to the pre-separated and recovered thermoplastic resin, and a heating and melting step of heating and melting the mixture, and a method for recycling thermoplastic resin, Also provide.

  Here, the thermoplastic resin separated and recovered from the waste is preferably a fossil resource-derived thermoplastic resin and / or a biomass-derived thermoplastic resin.

  The fossil resource-derived thermoplastic resin preferably contains a polyolefin-based thermoplastic resin as a main component.

  The biomass-derived thermoplastic resin preferably contains a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid.

  Furthermore, the hydrolysis inhibitor is a carbodiimide compound, and is preferably included in an amount of 0.01 to 10 parts by weight with respect to 100 parts by weight of the biomass-derived thermoplastic resin.

  Here, in the mixing step, a modifier and / or an antioxidant can be further added and mixed.

  The modifier comprises a block copolymer obtained by bonding a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid and an aliphatic polyester, a polyolefin resin component, and a polystyrene resin component. It is preferable that it is a 1 type, or 2 or more types of combination selected from the modified polymer containing the olefin containing the block copolymer containing a unit, a carboxylic acid group, or its derivative group as a structural unit.

  The antioxidant includes a phenolic antioxidant and a phosphorus antioxidant, and the phenolic antioxidant and the phosphorus antioxidant are separated from the recovered thermoplastic resin and the hydrolysis inhibitor. It is preferable that 0.01 to 5 parts by weight of each of the modifier and the antioxidant is contained in a total of 100 parts by weight.

  Since the thermoplastic resin composition of the present invention and the thermoplastic resin molded article of the present invention comprising the thermoplastic resin composition of the present invention can withstand long-term use, they are used in air conditioners, televisions, refrigerators, washing machines (hereinafter referred to as It may be suitably used as a member having high required characteristics, such as home appliances such as home appliances (sometimes referred to as four items of home appliances), OA equipment, and electric / electronic components.

  According to the thermoplastic resin production method and the recycling method of the present invention, it is possible to material-recycle a thermoplastic resin containing a biomass-derived thermoplastic resin component. Such material recycling of the thermoplastic resin containing the biomass-derived thermoplastic resin component can be performed using the equipment for material recycling of the thermoplastic resin material containing the conventional thermoplastic resin component derived from fossil resources, It is possible to reduce a new capital investment for recycling a thermoplastic resin containing a thermoplastic resin component derived from biomass.

  Furthermore, according to the method for recycling a thermoplastic resin of the present invention, it is possible to recycle a thermoplastic resin containing a biomass-derived thermoplastic resin component, thereby reducing the use of a new fossil resource-derived thermoplastic resin. it can.

Hereinafter, the present invention will be described in detail with reference to embodiments.
<Thermoplastic resin composition>
The thermoplastic resin composition of the present invention comprises a fossil resource-derived thermoplastic resin component (A), a biomass-derived thermoplastic resin component (B), and a hydrolysis inhibitor (C). Such a thermoplastic resin composition of the present invention can withstand long-term use in the same manner as the thermoplastic resin molded body of the present invention shown below, and is preferably used as a member having high required characteristics. Can do.

<Thermoplastic resin component (A) derived from fossil resources>
The thermoplastic resin component (A) contained in the thermoplastic resin composition of the present invention is a thermoplastic resin derived from a fossil resource. Here, “fossil resources” include natural gas as well as crude oil and coal. The “fossil resource-derived thermoplastic resin component” means a thermoplastic resin produced by polymerization reaction of various compounds obtained using such a fossil resource as a raw material.

  Examples of the thermoplastic resin component (A) include polyolefin, polystyrene, polyester, polyurethane, polycarbonate, polyamide, acrylic, acrylonitrile, polyvinyl chloride, polyether, polyvinyl alcohol, poly Examples thereof include thermoplastic resins such as vinyl acetate and fluororesin.

  As the thermoplastic resin component (A), it is particularly preferable to use a polyolefin-based thermoplastic resin among the thermoplastic resins described above. The polyolefin-based thermoplastic resin has a relatively good miscibility with the biomass-derived thermoplastic resin component (B) described later.

  As the thermoplastic resin component (A), a thermoplastic resin recovered from waste can be suitably used. Thereby, material recycling can be effectively realized. In particular, the polyolefin-based thermoplastic resin is one of the most widely used fossil resource-derived thermoplastic resins. Therefore, by using a thermoplastic resin recovered from waste as a fossil resource-derived thermoplastic resin. The amount of the polyolefin-based thermoplastic resin used as a virgin material can be reduced, which is extremely preferable in terms of the environment. The “virgin material” means an unused resin material that has not been recovered from waste. Such waste is not particularly limited as long as a member containing a thermoplastic resin is used, and examples thereof include household appliances, OA equipment, and electric / electronic components. . Moreover, as a method of recovering the thermoplastic resin component (A) from the waste, for example, a method of recovering through a resin recovery step described later is suitably used.

  In addition, as a thermoplastic resin component (A) derived from a fossil resource, 1 type of resin components may be contained and 2 or more types of resin components may be contained.

<Biomass-derived thermoplastic resin component (B)>
The thermoplastic resin component (B) contained in the thermoplastic resin composition of the present invention is a thermoplastic resin derived from biomass. Here, the term “biomass-derived thermoplastic resin component” refers to a thermoplastic resin produced by polymerizing various compounds obtained from plants or microorganisms, as well as direct extraction from such plants or microorganisms. Is included.

  Some of such biomass-derived thermoplastic resin components (B) have the characteristic of exhibiting biodegradability. Examples of biomass-derived thermoplastic resin component (B) include thermoplastic resins such as polybutylene succinate, polytrimethylene terephthalate, polylactic acid-based polymer system, polyhydroxyalkanoate, cellulose acetate, esterified starch, and bacterial cellulose. Can be mentioned. Examples of the polylactic acid-based polymer system include a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid.

  As the biomass-derived thermoplastic resin component (B), it is preferable to use a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid. Since the polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid absorbs carbon dioxide during the growth of plants, the concentration of carbon dioxide in the environment does not increase even if incinerated at the time of disposal. Therefore, it is environmentally suitable. Moreover, it has various properties such as excellent mechanical properties and is excellent in mass productivity as a molding material.

  As a property of the thermoplastic resin derived from biomass, the softening point is 100 to 400 ° C, preferably 120 to 350 ° C, and more preferably 150 to 300 ° C.

  When the softening point is less than 100 ° C., mixing with the fossil resource-derived thermoplastic resin component (A) becomes insufficient, and when the softening point exceeds 400 ° C., the molding temperature becomes too high and the thermoplasticity derived from the fossil resource. There is a possibility that the resin component (A) is thermally decomposed.

  In addition, 1 type of resin components may be contained as a thermoplastic resin component (B) derived from biomass, and 2 or more types of resin components may be contained.

  As the thermoplastic resin component (B), a thermoplastic resin recovered from waste can be suitably used. Thereby, material recycling can be effectively realized. Such waste is not particularly limited as long as a member containing a thermoplastic resin is used, and examples thereof include household appliances, OA equipment, and electric / electronic components. . Moreover, as a method of recovering the thermoplastic resin component (B) from the waste, for example, a method of recovering through a resin recovery step described later is preferably used.

<Hydrolysis inhibitor (C)>
The thermoplastic resin composition of the present invention further contains a hydrolysis inhibitor (C). The hydrolysis inhibitor is not particularly limited as long as it is a compound having a function of preventing or suppressing the hydrolysis reaction of the biomass-derived thermoplastic resin component (B). For example, a carbodiimide compound, epoxidized soybean oil, and the like are used. Can be mentioned. Among these, a carbodiimide compound is preferable from the viewpoint of transparency and thermal stability.

  A carbodiimide compound means a compound having one or more carbodiimide groups in the molecule. An example of such a compound is Carbodilite LA-1 manufactured by Nisshinbo Co., Ltd. Here, the carbodiimide compound can prevent or suppress the hydrolysis reaction of the biomass-derived thermoplastic resin component (B), that is, the binding of the biomass-derived thermoplastic resin composition cut by hydrolysis, that is, This is considered to be because a carbodiimide compound containing a carbodiimide group is recombined with a carboxyl group and a hydroxyl group to suppress further hydrolysis reaction. Here, the carbodiimide group, the carboxyl group, and the hydroxyl group are represented by the following chemical formulas (1) to (3), respectively.

  Here, the reaction between the carboxyl group and the carbodiimide group can be expressed by the following formula (4).

  Moreover, reaction of a hydroxyl group and a carbodiimide group can be expressed by the following formula (5).

  As shown in the above reaction formula, the carbodiimide compound acts to prevent or suppress hydrolysis by causing a bonding reaction and a crosslinking reaction of the cut biomass-derived thermoplastic resin composition. Thereby, the initial characteristics of the thermoplastic resin composition and the thermoplastic resin molded article of the present invention can be maintained.

  The carbodiimide compound is preferably contained in an amount of 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin component (B). If it is less than 0.01 part by weight, the resulting thermoplastic resin molded article may not exhibit sufficient characteristics to withstand long-term use. Moreover, it is because there exists a possibility that the thermoplastic resin component derived from biomass may deteriorate significantly when material-recycling the obtained thermoplastic resin molding. On the other hand, when the amount exceeds 10 parts by weight, deterioration of the thermoplastic resin component derived from biomass in the case of material recycling of the obtained thermoplastic resin molded article can be suppressed, but costly problems and use of resources derived from new fossil resources There is a risk of deviating from the purpose of reducing the above.

  Moreover, it is preferable that content of a carbodiimide compound is determined according to long-term reliability, such as durability required for the product in which the thermoplastic resin molding of this invention is used.

  Furthermore, it is preferable that the content of the carbodiimide compound is determined in consideration of a recycling scenario. In other words, if the scenario of recycling a molded product that has been recycled by adding a carbodiimide compound is thermal recycling, long-term reliability needs to be ensured until the molded product that has been recycled is thermally recycled. If the molded body is subjected to a scenario where the material is further recycled, it can be said that long-term reliability must be ensured while the molded body exists in the market.

<Modifier>
The thermoplastic resin composition of the present invention may further contain a modifier. Here, the “modifier” means an agent for adjusting or controlling the properties of the obtained thermoplastic resin molded article of the present invention. As the modifier contained in the thermoplastic resin composition of the present invention, any compound having such a function may be used. For example, L-lactic acid and / or D-lactic acid may be used. A block copolymer obtained by bonding a polylactic acid polymer as a main component and an aliphatic polyester can be suitably used. Here, the aliphatic polyester is not particularly limited, and examples thereof include an aliphatic polyester composed of glycol and aliphatic dicarboxylic acid such as polybutylene succinate, polyethylene succinate, polybutylene succinate adipate, and the like. . As a block copolymer obtained by bonding a polylactic acid polymer containing L-lactic acid and / or D-lactic acid as a main component and an aliphatic polyester, for example, Daimate Ink Plamate (registered trademark) PD-150 is preferably used. Can be used.

  Another example of the modifier contained in the thermoplastic resin composition of the present invention is a block copolymer containing a polyolefin resin component and a polystyrene resin component as constituent units. Among them, the triblock copolymer having a skeleton in which the constituent units of the resin component are arranged at both ends of the constituent units of the polyolefin resin component is a polyolefin type that is a continuous phase that can be included in the thermoplastic resin composition of the present invention. It can be preferably used because it easily coordinates to the interface between the thermoplastic resin component and the polystyrene-based thermoplastic resin component which is the dispersed phase.

  Examples of the triblock copolymer containing the polyolefin resin component and the polystyrene resin component as structural units include styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-styrene block copolymer. (SBS), styrene-butylene-butadiene-styrene copolymer (SBBS), styrene-ethylene-butylene-olefin block copolymer (SEBC), and the like. Here, the ethylene / butylene block may be all hydrogenated polybutadiene, partially hydrogenated or not hydrogenated. As a triblock copolymer containing a polyolefin-based resin component and a polystyrene-based resin component as structural units, for example, Asahi Kasei Tuftec (registered trademark) P2000, which is a styrene-butylene-butadiene-styrene copolymer, is preferably used. Can do.

  Another example of the modifier contained in the thermoplastic resin composition of the present invention is a modified polymer containing an olefin containing a carboxylic acid group or a derivative group thereof as a structural unit.

  Here, such modified polymers include those in which a structural unit containing a carboxylic acid group or a derivative group thereof is blocked or grafted.

  Examples of the carboxylic acid group or its derivative group include maleic anhydride and the like. Therefore, such a modified polymer includes, for example, a maleic anhydride group in the main chain or side chain of polypropylene as a polyolefin. Specific examples thereof include maleic acid-modified SEBS. As a modified block copolymer in which a molecular unit containing a carboxylic acid group or a derivative group thereof is bonded to a polyolefin block, for example, Umex 1010 manufactured by Sanyo Chemical Co., Ltd. can be suitably used.

  Maleic acid-modified SEBS is particularly preferable because it contains maleic acid that can react with an ester group that is a structural unit contained in a biomass-derived thermoplastic resin component, and has good light resistance and heat resistance.

  In addition, 1 type of modifiers may be contained in the thermoplastic resin composition of this invention, and 2 or more types of modifiers may be contained.

<Antioxidant>
The thermoplastic resin composition of the present invention may further contain an antioxidant. The antioxidant is not particularly limited, and examples thereof include at least one selected from a phenol-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, and the like. Further, a “hybrid antioxidant” in which a phenolic antioxidant and a phosphorus antioxidant are combined may be used. Among these, the combined use of a phenolic antioxidant and a phosphorus antioxidant, or the use of a hybrid type antioxidant is particularly preferable. As such a hybrid type antioxidant, for example, ADK STAB AO612 manufactured by Asahi Denka Kogyo Co., Ltd. can be suitably used. By using an antioxidant, long-term reliability can be improved.

  It is preferable that 0.01 to 5 parts by weight of the antioxidant is contained in 100 parts by weight of the thermoplastic resin composition. Moreover, when using together 2 or more types of antioxidant, it is preferable that 0.01-5 weight part is contained in 100 weight part thermoplastic resin composition, respectively. If the addition amount is less than 0.01 parts by weight, a sufficient effect cannot be obtained, and if it exceeds 5 parts by weight, there is a possibility that the cost is disadvantageous. Even when the antioxidant is a hybrid type antioxidant, it is preferably contained in an amount of 0.01 to 5 parts by weight in 100 parts by weight of the thermoplastic resin composition.

  In addition, 1 type of antioxidant may be contained in the thermoplastic resin composition of this invention, and 2 or more types of antioxidant may be contained. Moreover, it may be contained together with the modifier, and only the antioxidant or only the modifier may be contained.

<Thermoplastic resin molding>
The thermoplastic resin molded article of the present invention is a molded article composed of the thermoplastic resin composition of the present invention.

  The shape of the thermoplastic resin molding of the present invention is not particularly limited. That is, for example, the shape of the thermoplastic resin molded body of the present invention may be a shape molded to be a shape used as a member of various products.

  Alternatively, it may be a pellet shape, a sheet shape, a film shape, a pipe shape, or the like, which is a shape used as a precursor used in the step of forming into the shape of such a member.

  When the thermoplastic resin molded body of the present invention has a shape used as a member of various products, examples of such products include home appliances, OA equipment (information equipment such as personal computers, and office equipment such as printers and copiers). In particular, it is preferable to have a shape used as a member of an air conditioner, a television set, a refrigerator, or a washing machine that is a home appliance.

  On the other hand, when the thermoplastic resin molding of the present invention has a shape as a precursor used in the step of molding into the shape of the member as described above, the shape is particularly preferably a pellet. In this case, the particle size of the pellet is not particularly limited, but is preferably 1 mm or more, and more preferably 2 mm or more. Moreover, it is preferable that the particle size of a pellet is 8 mm or less, and it is more preferable that it is especially 5 mm or less. When the particle size of the pellet is less than 1 mm, there is a tendency that the workability is lowered due to 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 it is uniformly mixed. There is a tendency not to be refined.

<Method for producing thermoplastic resin molding>
The thermoplastic resin molded article of the present invention can be produced by heating and melting a mixture comprising the components constituting the thermoplastic resin composition and molding the mixture into a specific shape. Heat melting and molding are the same as in the following thermoplastic resin recycling method.

<Recycling method of thermoplastic resin>
In the method for producing a thermoplastic resin molded article, the thermoplastic resin (A) and / or the thermoplastic resin (B) of the mixture comprising the components constituting the thermoplastic resin composition is recovered from waste as at least a part. In the case where a thermoplastic resin is used, the present invention also provides a method for recycling the thermoplastic resin recovered from the waste. In particular, the method for recycling a thermoplastic resin of the present invention provides an efficient method for recycling a thermoplastic resin containing a biomass-derived thermoplastic resin component.

The thermoplastic resin recycling method of the present invention is preferably roughly divided into two steps, namely,
(A) a resin recovery step of separating and recovering the thermoplastic resin from the waste;
(B) A molded article manufacturing step of adding an additive such as a modifier as necessary to the thermoplastic resin recovered in step (a), mixing, heating and melting to produce a thermoplastic resin molded article, including. Hereafter, the said resin collection | recovery process and a molded object manufacturing process are demonstrated in detail.

(Resin recovery process)
FIG. 1 is a schematic flowchart showing a preferred example of the recycling method of the present invention. Hereinafter, the resin recovery process will be described with reference to FIG. The resin recovery step includes steps 101 to 105 in the example shown in FIG.

  First, waste containing a thermoplastic resin is collected (step 101). Here, the thermoplastic resin contained in the waste is not particularly limited, but may be a thermoplastic resin containing a thermoplastic resin component derived from biomass. According to the method for recycling a thermoplastic resin of the present invention, it is possible to efficiently recover a thermoplastic resin containing a biomass-derived thermoplastic resin component that could not be achieved conventionally.

  The waste is not particularly limited as long as it includes a thermoplastic resin, and examples thereof include home appliances such as four home appliances, OA equipment, and electric / electronic components. The recovered waste is not limited to one type, and two or more types of waste may be recovered and used for one resin recovery step.

  Here, in Table 1, in the members made of plastics included in TVs, refrigerators, washing machines, and air conditioners (hereinafter sometimes referred to as four items of home appliances), representative composition ratios by resin component constituting the members An example is shown. In the present specification, the term “plastic” means a broad concept including a thermoplastic resin and a polymer such as a thermosetting resin or rubber.

As shown in Table 1, in the members made of plastics included in the four household appliances, the total composition ratio of the polyolefin-based thermoplastic resin component and the polystyrene-based thermoplastic resin component is 95.1% by weight for televisions, refrigerators Is 67.3 wt%, the washing machine is 85.7 wt%, the air conditioner is 68.1 wt%, which is an extremely high value exceeding 60 wt%. Therefore, in the four home appliances, among the members made of plastic, recycling a member made of plastic containing a polyolefin-based thermoplastic resin component and / or a polystyrene-based thermoplastic resin component is called effective use of resources. It is particularly important from the viewpoint, and if the material consisting of at least a polyolefin-based thermoplastic resin component and a polystyrene-based thermoplastic resin component can be material-recycled, the recycling rate of the members made of plastics of four home appliances exceeds 60%. In the subsequent process, the collected waste is roughly disassembled and a member made of thermoplastic resin, a large metal member such as a compressor, a heat exchanger, or the like is taken out (step 102). As a method of dismantling, a conventionally known appropriate method can be adopted, and for example, dismantling by a human hand can be exemplified. Note that step 102 is not an essential process and can be omitted depending on the type of waste.

  In the subsequent process, the remaining members of the waste from which the members made of thermoplastic resin, large metal members, and the like are taken out are roughly crushed (step 103). As the rough crushing method, a conventionally known appropriate method can be adopted, and examples thereof include a method using a large crusher such as an impact crusher or a shear crusher. Hereinafter, the crushed material generated by rough crushing is referred to as a coarsely crushed material.

  The particle size of the coarsely crushed product produced by the coarse crushing is not particularly limited, but is preferably 10 mm or more, and more preferably 40 mm or more. Moreover, it is preferable that the particle size of a coarsely crushed material is 80 mm or less, and it is more preferable that it is 60 mm or less. When the particle size of the coarsely crushed material is less than 10 mm or more than 80 mm, the metal selection accuracy in the next process tends to decrease. In addition, when the particle size of the coarsely crushed material is less than 10 mm, it takes a long time for crushing, so that the plastic contained in the waste tends to be melted or deteriorated by thermal oxidation. Furthermore, when the particle size of the coarsely crushed material exceeds 80 mm, the bulk specific gravity tends to be small, and the workability in the subsequent processes tends to be adversely affected. Therefore, it is particularly preferable to crush so that the particle diameter is about 60 mm.

  In the case where the step 102 is provided and the member made of thermoplastic resin is taken out from the waste, the remaining member of the waste from which the member is taken out separately, or the member made of the thermoplastic resin or the large metal member is taken out. Rough crushing with the member is preferred.

  In the subsequent process, a metal-based coarsely crushed product made of iron, copper, aluminum, or the like is selectively removed from the roughly crushed product obtained in Step 103 (Step 104), and the plastic crushed material is recovered. Here, the roughly crushed plastic material means a roughly crushed material made of plastic. As a method for selectively removing the metal-based coarsely crushed material, a conventionally known appropriate method can be employed. For example, iron-based coarsely crushed materials can be selected and removed using magnetic force. In addition, aluminum-based and copper-based coarsely crushed materials can be selectively removed using eddy currents.

  In addition, although not shown in figure, you may provide the process of classifying and removing a low bulk specific gravity crushed material before or after step 104. Here, the low bulk specific gravity crushed material means a crushed material having a bulk specific gravity of 0.3 or less, and examples thereof include a polyurethane-based heat-insulated material and a foamed styrene-based material. By providing this process, workability of the subsequent processes is improved.

  For the selective removal of the low-bulk specific gravity crushed material, a conventionally known appropriate method can be adopted, for example, a method using wind power can be mentioned. In this way, when a process for selectively removing crushed materials with low bulk specific gravity is provided, and further, when selecting and removing metal-based crushed materials using magnets and selecting and removing metal-based crushed materials using eddy currents, The order is not particularly limited, but from the viewpoint of sorting efficiency, first, iron-based coarsely crushed materials are sorted and removed by magnetic force, then aluminum-based and copper-based crushed materials are sorted and removed by eddy current, and finally It is preferable to screen and remove the low bulk specific gravity crushed material by wind power. Through the above steps, the metal-based crushed material and the low bulk density crushed material are removed from the waste, and the plastic crushed material is sorted and recovered.

  In addition, although not shown in figure, it is preferable that a plastic crushed material is finely crushed before using for the following process (step 105). As a fine crushing method, a conventionally known appropriate method can be adopted, and for example, a method using a large crusher such as a shear crusher can be mentioned. Hereinafter, the finely crushed material is referred to as “finely crushed material”.

  The size of the finely crushed material is not particularly limited, but the maximum length of the finely crushed material is about 5 to 20 mm so that it can be sufficiently melted and mixed with other substances in a subsequent process. It is preferable that it is about 10 mm. In addition, this process is performed as needed and may be omitted. Further, the fine crushing step may be performed after the next step 105.

  In the subsequent process, the crude plastic crushed material or the fine crushed material is separated according to the resin component constituting the plastic using the specific gravity difference (step 105). The plastic crushed material or finely crushed material includes the roughly crushed material or the finely crushed material of the thermoplastic resin taken out in step 102. Hereinafter, this process is referred to as “specific gravity separation process”.

  The specific gravity separation step (step 105) will be described in detail. In the method for recycling the thermoplastic resin of the present invention, it is preferable to perform the specific gravity separation operation twice using two types of X separation liquid and Y separation liquid having different specific gravities. Here, the specific gravity separation operation means that plastic crushed material or finely crushed material is put into, for example, a liquid (referred to as a separation liquid) accommodated in a mixing and stirring tank and separated because it has a specific gravity smaller than the specific gravity of the separation liquid. This refers to a series of operations for recovering the crushed plastic material floating in the liquid or on the surface of the separation liquid using a method such as an overflow method. The crushed material having a specific gravity greater than the specific gravity of the separation liquid settles toward the bottom of the container, but these can be recovered by suction or the like.

  Table 2 shows a typical example of the range of specific gravity of the thermoplastic resin composed of various resin components.

As can be seen from Table 2, the range of specific gravity of the thermoplastic resin comprising the polyolefin resin component is generally within the range of 0.89 to 0.91 g / cm ³ , and the thermoplastic resin comprising the polystyrene resin component. the range of specific gravities generally understood to be included within the scope of 1.04~1.05g / cm ^3. Moreover, it turns out that the specific gravity of most thermoplastic resins which consist of another resin component is generally contained in the range of 1.05-2.00 g / cm < ³ >. However, some deviation may occur due to an increase in specific gravity due to the addition of a filler or the like, or a decrease in specific gravity due to foaming.

More generally, by using a separation liquid having a specific gravity in the range of 1.01 to 1.08 g / cm ³ , a plastic crushed material composed of a polyolefin-based thermoplastic resin component and a polystyrene-based thermoplastic resin component are used. It turns out that it is possible to isolate | separate most of the plastic crushed material and the plastic crushed material which consists of another resin component, and generally specific gravity is the range of 0.92-1.00 g / cm < ³ >. It can be seen that by using the separation liquid in the above, it is possible to separate the crushed plastic material composed of the polyolefin-based thermoplastic resin component and the crushed plastic material composed of the polystyrene-based thermoplastic resin component.

Accordingly, in the specific gravity separation step (step 105), first, the X separation liquid is preferably a liquid having a specific gravity of 1.0 to 1.1 g / cm ³ , more preferably 1.01 to 1.08 g / cm ^3. Separation of specific gravity using, separating plastic crushed material made of polyolefin thermoplastic resin component and plastic crushed material made of polystyrene thermoplastic resin component from plastic crushed material made of other resin components, rubber crushed material, etc. To do. When the specific gravity of the X separation liquid is less than 1.0 g / cm ³ , the plastic crushed material made of polystyrene-based thermoplastic resin component is mainly used for the crushed plastic material or rubber crushed material made of other resin components. The tendency for crushed plastic to be mixed increases. In addition, when the specific gravity of the X separation liquid exceeds 1.1 g / cm ³ , a polyamide crushed polycarbonate resin component and a crushed plastic plastic polyolefin component and a crushed polystyrene thermoplastic resin component are used. There is a greater tendency for crushed plastics and crushed rubbers to enter.

Next, the Y separation liquid, preferably 0.92~1.01g / cm ^3, further preferably subjected to gravity separation using a liquid having a specific gravity of 0.95~1.00g / cm ^3, a polyolefin thermoplastic A plastic crushed material composed of a resin component and a plastic crushed material composed of a polystyrene-based thermoplastic resin component are separated. When the specific gravity of the Y separation liquid is less than 0.92 g / cm ³ , a part of the plastic crushed material mainly composed of the plastic crushed material comprising the polyolefin-based thermoplastic resin component is settled, and the recovery rate tends to decrease. . Also, if the specific gravity of the Y separating liquid exceeds 1.01 g / cm ³ , the plastic crushed material mainly composed of the polystyrene-based thermoplastic resin component is mixed with the plastic crushed material composed of the polyolefin-based thermoplastic resin component. The tendency to do becomes large.

For example, each of the crushed plastic material made of polyolefin-based thermoplastic resin component and the crushed plastic material made of polystyrene-based thermoplastic resin component, which is separated and recovered in this step, contains the crushed plastic material made of other thermoplastic resin components. It may be. Such a mixture of crushed plastics composed of other thermoplastic resin components may occur for the following reasons, for example. That is, when the plastic crushed material made of polystyrene-based thermoplastic resin component is made porous by foaming, the plastic crushed material made of polystyrene-based thermoplastic resin component to be precipitated in the separated liquid rises, and polyolefin It can partly mix in the crushed plastic mainly composed of the crushed plastic made of the thermoplastic resin component. Further, there may be a case where a light specific gravity foreign substance adheres to a plastic crushed material composed of a polystyrene-based thermoplastic resin component and floats and mixes in the specific gravity liquid without being settled. Furthermore, when the crushed material of the thermoplastic resin containing the thermoplastic resin component derived from biomass is contained in the crushed plastic material, and the specific gravity of the crushed material is, for example, less than 1.0 g / cm ³ , The crushed material is separated and recovered together with the plastic crushed material comprising the polyolefin-based thermoplastic resin component.

  For example, the crushed plastic made of polyolefin-based thermoplastic resin component and the crushed plastic made of polystyrene-based thermoplastic resin component separated and recovered as described above are the thermoplastic resin composition and the thermoplastic resin molded article of the present invention. This contributes to the thermoplastic resin component (A), or to the thermoplastic resin component (A) and the thermoplastic resin component (B).

  In the above description, the specific gravity separation operation using the Y separation liquid is performed after the specific gravity separation operation using the X separation liquid. However, this is a preferable order, and the order is not limited to this. . Further, the specific gravity separation operation is not limited to twice, and may be performed three or more times depending on circumstances.

  The separation liquid having a desired specific gravity can be adjusted, for example, as follows. That is, when the desired specific gravity is less than 1.0, water is added to a solvent having a specific gravity of less than 1.0, such as alcohol such as ethanol, until the desired specific gravity is obtained. If the desired specific gravity is greater than 1.0, a salt such as sodium chloride is added to water to obtain the desired specific gravity. If the desired specific gravity is 1.0, water is used. Although the solvent used as the main ingredient of the specific gravity liquid is not necessarily water, the solvent used as the main ingredient of the specific gravity liquid is preferably water in consideration of the ease of adjusting the specific gravity and the treatment after using the specific gravity liquid.

(Molded body manufacturing process)
Hereinafter, the said molded object manufacturing process is demonstrated according to FIG.

  First, among the crushed plastic material comprising the polyolefin-based thermoplastic resin component collected in step 105 and the crushed plastic material comprising the polystyrene-based thermoplastic resin component, those to be recycled are washed and dried (step 106). ). As a method of washing and drying, a conventionally known appropriate method can be adopted, and examples thereof include a method using a blade rotor, a dehydrating screen type washing dehydrating dryer, and the like.

  In a subsequent process, the thermoplastic resin component (to be recycled) is washed and dried, for example, a plastic crushed material made of a polyolefin-based thermoplastic resin component or a plastic crushed material made of a polystyrene-based thermoplastic resin component. B) a thermoplastic resin comprising a biomass-derived thermoplastic resin component as well as a hydrolysis inhibitor (C) and, if necessary, a modifier for adjusting the properties of the finally obtained thermoplastic resin molded article Other additives are added and mixed uniformly (step 107). Here, the thermoplastic resin comprising the thermoplastic resin component derived from biomass as the thermoplastic resin component (B) to be uniformly mixed is the thermoplastic comprising the thermoplastic resin component derived from the fossil resource as the thermoplastic resin component (A). A composite material with resin may be used, and at least in the step of uniformly mixing (step 107), the thermoplastic resin containing the thermoplastic resin component (B) and the hydrolysis inhibitor (C) may be mixed. In addition, the hydrolysis inhibitor (C) is preliminarily obtained from the above-mentioned plastic crushed material, a thermoplastic resin composed of a biomass-derived thermoplastic resin component as the thermoplastic resin component (B), and a fossil as the thermoplastic resin component (A). It is blended in at least one of a composite material of a thermoplastic resin comprising a thermoplastic resin component derived from resources and a thermoplastic resin comprising a thermoplastic resin component derived from biomass as the thermoplastic resin component (B). If necessary, a modifier and other additives may be added and mixed uniformly. Alternatively, it comprises a thermoplastic resin composed of the above-mentioned crushed plastic and a thermoplastic resin component derived from biomass as the thermoplastic resin component (B) and / or a thermoplastic resin component derived from fossil resources as the thermoplastic resin component (A). After mixing a thermoplastic resin and a composite material of a thermoplastic resin component derived from biomass as a thermoplastic resin component (B), a hydrolysis inhibitor (C) may be added thereto. . Here, if necessary, a modifier or other additives may be added and mixed uniformly.

  The specific example of the thermoplastic resin which consists of a thermoplastic resin component derived from biomass is as having already mentioned above. Among them, it is preferable to use a polylactic acid polymer containing L-lactic acid and / or D-lactic acid as a main component as the biomass-derived thermoplastic resin component. Since the polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid absorbs carbon dioxide during the growth of plants, the concentration of carbon dioxide in the environment does not increase even if incinerated at the time of disposal. Therefore, it is environmentally suitable. Moreover, it has various properties such as excellent mechanical properties and is excellent in mass productivity as a molding material.

  As a property of the thermoplastic resin which consists of a thermoplastic resin component derived from biomass, a softening point is 100-400 degreeC, Preferably it is 120-350 degreeC, More preferably, it is 150-300 degreeC.

  When the softening point is less than 100 ° C., the mixing with the crushed plastic material made of polyolefin-based thermoplastic resin component or the crushed plastic material made of polystyrene-based thermoplastic resin component becomes insufficient, and the softening point exceeds 400 ° C. If the molding temperature becomes too high, the crushed plastic made of polyolefin-based thermoplastic resin component or the crushed plastic made of polystyrene-based thermoplastic resin component may be thermally decomposed.

  The addition amount of the thermoplastic resin composed of the biomass-derived thermoplastic resin component is not particularly limited, but should be determined according to the required characteristics of the product in which the obtained thermoplastic resin molded article is used. Here, as described above, the crushed material recovered in step 105 may include a crushed material of a thermoplastic resin containing a thermoplastic resin component derived from biomass. There is no need to add a thermoplastic resin composed of the derived thermoplastic resin component. In such a case, not only a thermoplastic resin composed of a polyolefin-based thermoplastic resin component and a thermoplastic resin composed of a polystyrene-based thermoplastic resin component, but also a thermoplastic resin containing a biomass-derived thermoplastic resin component is recycled. Therefore, it is more preferable from the viewpoint of effective use of resources.

  Here, as the thermoplastic resin composed of the biomass-derived thermoplastic resin component, a thermoplastic resin recovered from waste can be suitably used. Thereby, material recycling of the thermoplastic resin derived from biomass can be effectively realized. As the thermoplastic resin composed of the biomass-derived thermoplastic resin component recovered from the waste, the thermoplastic resin composed of the polyolefin-based thermoplastic resin component or the polystyrene-based thermoplastic resin component in the specific gravity separation process described above. It may be collected together, or may be collected by manual dismantling in Step 102.

  A hydrolysis inhibitor (C) is further added to the recovered plastic crushed material. Further, a modifier and an antioxidant as described above are further added as necessary. In addition, when the hydrolysis inhibitor (C) is contained in a thermoplastic resin composed of a recovered plastic crushed material and / or a biomass-derived thermoplastic resin component in advance, the hydrolysis inhibitor (C) May not be added again. It is sufficient that the hydrolysis inhibitor (C) is contained in at least the thermoplastic resin composition obtained by material recycling and the thermoplastic resin molded article. By adding the hydrolysis inhibitor (C), not only can the thermoplastic resin molded product develop characteristics that can withstand long-term use, but it can also be used for a long time for molded products after material recycling. It is possible to develop characteristic values that can withstand.

  Here, the addition of the hydrolysis inhibitor (C) in the thermoplastic resin recycling method of the present invention is not performed every time the material is recycled when the thermoplastic resin molded body of the present invention is subjected to material recycling multiple times. Alternatively, the hydrolysis inhibitor (C) may be added at least once during recycling. Further, the amount of the hydrolysis inhibitor (C) added is preferably the above-mentioned amount, but more preferably the biomass-derived thermoplastic resin component and the water in the thermoplastic resin contained in the waste recovered at the time of recycling. After detecting the blending ratio of the decomposition inhibitor (C), the blending amount of the hydrolysis inhibitor (C) should be determined in consideration of a scenario after use of the recycled thermoplastic resin composition.

  The above-mentioned various components are added, and the resulting mixture is mixed so as to be uniform. Such mixing can be performed by a conventionally known method such as a method using a tumbler mixer or the like.

  In the subsequent step, the obtained mixture is heated and melted to obtain the thermoplastic resin composition of the present invention (step 108), and further molded as necessary (step 109) to obtain a thermoplastic resin molded body.

  Here, when the melting point of the thermoplastic resin composition is T ° C., the heating temperature at the time of heat melting and molding is preferably T ° C. or higher, and more preferably (T + 10) ° C. or higher. The heating temperature at the time of heat melting and molding is preferably (T + 120) ° C. or lower, more preferably (T + 80) ° C. or lower. This is because when the heating temperature at the time of heat melting and molding is less than T ° C., the thermoplastic resin composition does not sufficiently melt and tends to be difficult to mold, and at the time of heat melting and molding This is because if the heating temperature exceeds (T + 120) ° C., the thermoplastic resin composition tends to be thermally deteriorated.

  The shape of the thermoplastic resin molded body is not particularly limited. That is, for example, the shape of the thermoplastic resin molded body may be a shape formed to be a shape used as a member of various products, and as a precursor used in the process of forming the shape of such a member. The shape may be a pellet shape, a sheet shape, a film shape, a pipe shape, or the like.

  Further, the shape of the thermoplastic resin molded body is not limited to the above-mentioned shapes, and is particularly preferably a molding process (step 109) such as one obtained by heating and melting and then simply agglomerated or crushed into an irregular shape. Some that have not passed are also included.

  When the thermoplastic resin molding has a shape used as a member of various products, examples of such products include home appliances, OA equipment (including information equipment such as personal computers and office equipment such as printers and copiers). In particular, it is preferable to have a shape used as a member of an air conditioner, a television set, a refrigerator, or a washing machine that is a household electric appliance. In addition, as a method of forming into a shape used as a member of various products from a pellet shape, a sheet shape, a film shape, a pipe shape or the like as a precursor, a conventionally known method can be used, For example, a method using an injection molding machine such as a screw inline type injection molding machine or a plunger type injection molding machine can be used.

  On the other hand, when the thermoplastic resin molded body has a shape as a precursor used in the step of molding into the shape of the member as described above, the shape is particularly preferably a pellet. In this case, the particle size of the pellet is not particularly limited, but is preferably 1 mm or more, and more preferably 2 mm or more. Moreover, it is preferable that the particle size of a pellet is 8 mm or less, and it is more preferable that it is especially 5 mm or less. When the particle size of the pellet is less than 1 mm, there is a tendency that the workability is lowered due to floating, and when the particle size of the pellet exceeds 8 mm, it does not melt sufficiently in the cylinder of the molding machine. There is a tendency not to be refined.

  A conventionally known method can be used as a method for forming a pellet, sheet, film, pipe, or the like as a precursor, such as a single screw extruder or a multi-screw extruder. A method using an extrusion molding machine such as can be used. When forming into a pellet form, methods such as sheet cutting, strand cutting, hot air cutting, underwater cutting, and the like can be used. Among these methods, when molding into a specific shape by injection molding later, an underwater cut that can smoothly supply the resin raw material and can cope with a large amount of processing is particularly preferable. In addition, in order to manage quality etc., it is preferable that the thermoplastic resin molding of this invention investigates and manages a characteristic value for every lot.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Examples 1-4>
(Recovery of thermoplastic resin)
Steps 101 to 105 shown in the flowchart of FIG. 1 were performed to recover the crushed thermoplastic resin from the waste. First, a household electrical appliance selected from the group consisting of an air conditioner, a TV, a refrigerator, and a washing machine is collected as waste (step 101), manually disassembled (step 102), and then crushed using a normal crusher (step). 103) From the obtained crushed material, the metal-based crushed material is sorted by a sorter using a normal magnetic force, and further, the low bulk specific gravity crushed material is sorted by a sorter using a normal wind force, and the remaining plastic coarsely crushed The material was collected (step 104).

  Next, the crushed plastic made of a polyolefin-based thermoplastic resin component contained in the recovered plastic crushed material was separated using a separation liquid having a specific gravity of 1.08 and a specific gravity of 1.00 using the difference in specific gravity ( Step 105). Specifically, it is as follows. The recovered crude plastic crushed material is put into a mixing and stirring tank filled with a sodium chloride aqueous solution with a specific gravity of 1.08, stirred, and then floated (plastic crushed material comprising polyolefin-based and polystyrene-based thermoplastic resin components) ) Was collected by the overflow method, and the precipitate (crushed plastic material including other resin components, rubber, metal, etc.) was collected by suction together with an aqueous sodium chloride solution. Here, the sodium chloride aqueous solution which flowed out by the overflow method and the sodium chloride aqueous solution simultaneously recovered at the time of suction recovery were injected into the mixing and stirring tank using a pump and reused. Next, the plastic crushed material made of polyolefin and polystyrene thermoplastic components recovered as floating was put into a mixing and stirring tank filled with water having a specific gravity of 1.00, stirred, and then floated. (Plastic crushed material made of polyolefin-based thermoplastic resin component) and precipitated (plastic crushed material made of polystyrene-based thermoplastic resin component) were collected.

(Manufacture of molded products)
Next, the obtained crushed plastic material (A) comprising the polyolefin-based thermoplastic resin component was finely crushed and then washed. Next, a thermoplastic resin (B) composed of biomass-derived thermoplastic resin components, three kinds of modifiers (referred to as modifiers 1, 2 and 3, respectively), a hydrolysis inhibitor (C) and an antioxidant The agent was added in the proportions shown in Table 3, and uniformly mixed using a normal tumbler mixer to prepare four types of thermoplastic resin compositions. Here, in Table 3, the numerical values of (A), (B) and the modifier indicate the weight percent of each component in the total weight of (A), (B) and the modifier. Moreover, the numerical value of a hydrolysis inhibitor (C) and antioxidant has shown the weight part with respect to the total weight of 100 weight part of (A), (B), and a modifier.

  Here, the thermoplastic resin (B) composed of a biomass-derived thermoplastic resin component includes a polylactic acid polymer containing L-lactic acid and / or D-lactic acid as a main component (Lacia (registered trademark) manufactured by Mitsui Chemicals, Inc.). ) H-100J). The modifier 1 is a block copolymer (Plamate (registered trademark) manufactured by Dainippon Ink and Co., Ltd.) in which a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid and an aliphatic polyester are bonded. ) PD-150) was used. As the modifier 2, a modified block copolymer (Umex 1010 manufactured by Sanyo Chemical Co., Ltd.) in which a molecular unit containing a carboxylic acid group or a derivative group thereof was bonded to a polyolefin block was used. As the modifier 4, styrene-butylene butadiene-styrene (Asahi Kasei Corporation Tuftec (registered trademark) P2000), which is a triblock copolymer containing a polystyrene resin component and a polyolefin resin component, was used. The hydrolysis inhibitor (C) is a hydrolysis inhibitor (Nisshinbo Co., Ltd. Carbodilite (registered trademark) LA-1), which is a carbodiimide compound, and the antioxidant is a hybrid antioxidant (Asahi Denka). Industrial Co., Ltd. Adeka Stub AO612) was used.

  Next, these thermoplastic resin compositions are melt-kneaded at 220 ° C. using a twin-screw melt kneader / extruder having a screw diameter of 45 mm, and extruded to form pellets having a diameter of about 2 mm and a length of about 3 mm. Four types of thermoplastic resin moldings were produced.

(Production of recycled samples)
In order to investigate how the properties of the obtained thermoplastic resin molded article change each time the material is recycled by the recycling method of the present invention, the above-mentioned pellet-shaped thermoplastic resin molded article (resin with zero recycling) From the above, a material-recycled sample (recycled once resin) and a material-recycled sample (recycled resin twice) were produced. Specifically, it is as follows.

  FIG. 2 is a schematic flowchart for preparing a material-recycled sample from a resin that has been recycled zero times. As shown in FIG. 2, first, the above-mentioned pellet-shaped thermoplastic resin molding (resin with zero recycling) was injection-molded (step 201), and then a constant temperature and humidity chamber (Tokyo Rika) at a temperature of 60 ° C. and a humidity of 95%. It was left for 500 hours in KCL-2000W manufactured by Kikai Co., Ltd. (step 202). Next, the mixture is crushed using a normal crusher (step 203), sufficiently dried (step 204), melt-kneaded again under the same extrusion conditions using the same extruder, and subjected to extrusion molding ( Step 205), a pellet-shaped molded body was obtained. In this way, a molded article was recycled once.

  Next, steps 201 to 205 were performed again on the pellet-shaped molded body of one recycling, thereby obtaining a pellet-shaped molded body of two-time recycling. Here, the injection molding process, extrusion molding, and standing under high temperature and high humidity are performed every time the sample is recycled once and twice as described above, when the thermoplastic resin is material recycled. In addition, a large amount of heat load is applied at the time of injection molding, and materials can be deteriorated by these heat loads, and when molded products using thermoplastic resin are on the market, various conditions such as heat and humidity overlap and deteriorate. This is a faithful reproduction of this as much as possible. Leaving it under high temperature and high humidity simulates the usage condition in the market.

  Next, the recycled thermoplastic resin moldings once and twice are respectively put into a hopper of a 10-ton injection molding machine, and measured in accordance with ASTM under injection molding conditions of a molding temperature of 220 ° C. and a mold temperature of 40 ° C. Test pieces were prepared, and the following characteristics of each test piece were measured by the following measuring method.

  Moreover, after extruding the pellet-shaped thermoplastic resin molded article of recycling 0 times in Example 1, injection molding was performed under the same injection molding conditions as in Examples 1 to 4, and test specimens for measuring physical properties in accordance with ASTM were produced. .

(Measurement methods for various characteristics)
About the following characteristics, the test piece of Examples 1-4 (recycle 0 times-2 times) was measured with the following measuring methods.

  (I) “Tensile strength” and “elongation” were measured according to JIS K7113 as tensile yield strength and tensile elongation at break, respectively.

  (Ii) “Bending strength” and “flexural modulus” were measured according to JIS K7203.

(Iii) “Izod impact strength” was measured according to JIS K7110.
(Iv) “Surface impact strength” was measured according to JIS K7211.

(V) “MFR” was measured according to JIS K7210.
Here, “tensile strength” and “elongation” are materials that are stretched at a constant speed to obtain the relationship between stress and strain. The stretched material first undergoes elastic deformation, and then begins plastic deformation. When the 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”.

  “Bending strength” and “flexural modulus” are stresses applied to the center of the test piece supported at two points, so that the concave part has tensile stress and the convex part has compressive stress. As in “tensile strength” and “elongation”, the relationship between stress and strain is also obtained. The characteristics change depending on the balance between stress and strain from each measured value. For example, PP has a high strength but a low elastic modulus and a high elongation is a “soft and tenacious” material. Polylactic acid or the like is a “hard and brittle” material having both large strength and elastic modulus and small elongation.

  “Izod impact strength” refers to a phenomenon that instantaneously breaks when a material is loaded at a high speed, referred to as impact fracture, and resistance to the fracture is impact strength. Generally speaking, when the strength is high, the material is hard and strong, and when the strength is small, the material is brittle and weak. However, since the elasticity is large like rubber, the strength may be difficult to break.

  “Surface impact strength” refers to the height at which a weight is dropped from a certain height and the material breaks. For materials that are mixed with different materials, each material is at the interface. Since they are peeled off (not compatible), the surface impact strength is reduced, which is an indicator of compatibility.

  “MFR” expresses the fluidity and moldability of a material. For example, if a material undergoes hydrolysis, the fluidity increases. Compared to the material before hydrolysis, the value of MFR Is greatly expressed. That is, it can be an indicator of whether or not hydrolysis is occurring.

(Evaluation of test piece characteristics)
Table 4 shows the measurement results for the test pieces of Examples 1 to 4 (0 to 2 times of recycling). In Table 4, “-” indicates that a test piece for measuring physical properties based on ASTM could not be produced.

  As understood from Table 4, in the case where the antioxidant and the hydrolysis inhibitor were not added (Example 1), the MFR increased significantly after one recycling, and the tensile strength, bending strength and It was found that the flexural modulus was greatly reduced, and the thermoplastic resin molded body was severely deteriorated. Moreover, it was difficult to produce a test piece for measuring physical properties in accordance with ASTM from a pellet-shaped thermoplastic resin molded article that was recycled once. Furthermore, due to severe deterioration when the number of recycles was two, ASTM-compliant test specimens for measuring physical properties could not be produced.

  In addition, even when only an antioxidant was added (Example 2), it was severely deteriorated after one recycle as in Example 1, and a test piece for measuring physical properties in conformity with ASTM could be produced with two recycles. There wasn't. That is, it is understood that material recycling cannot be performed without adding a hydrolysis inhibitor. In the case where the hydrolysis inhibitor was added (Example 3), compared with Example 1 and Example 2, when the number of times of recycling was 1, the initial characteristic value (of the resin of 0 times of recycling in Example 1) It is understood that the range of decrease from the characteristic value is small. This is presumably because the hydrolysis inhibitor acts on polylactic acid to suppress deterioration.

  Furthermore, in the case of adding an antioxidant in addition to the hydrolysis inhibitor (Example 4), it is understood that the increase in MFR for each repeated recycling is further suppressed as compared with Example 3. . This indicates that oxidative degradation and hydrolysis are suppressed during extrusion molding, injection molding, heat load and humidity load under high temperature and high humidity, and material recycling can be repeated. However, in Example 3 and Example 4, when the number of recycles was 2, the tensile strength, bending strength, and flexural modulus were clearly compared with the initial characteristic values (characteristic values of the resin with zero recycling in Example 1). It can be understood that the material value cannot be recycled as a high-quality member.

<Example 5>
A pellet-shaped thermoplastic resin molded article having been recycled once in Example 4 was left in a constant temperature and humidity chamber for 500 hours under conditions of a temperature of 60 ° C. and a humidity of 95%, and then a normal crusher was used. And then sufficiently dried. Then, as a hydrolysis inhibitor, a carbodiimide compound (Nisshinbo Co., Ltd. Carbodilite (registered trademark) LA-1) was added in an amount of 1 part by weight, and extrusion molding was performed in the same manner as in Example 4 except that extrusion molding was performed. A test piece for measuring physical properties was prepared.

  Table 5 shows the MFR measurement results of the test piece obtained in Example 5. For comparison, Table 5 also shows the MFR measurement results for the test piece with one recycle and the test piece with two recycles in Example 4.

  As can be seen from Table 5, in Example 5, the addition of a hydrolysis inhibitor at the time of recycling hardly increased the MFR as compared with the case where it was not added, and the recycling was performed twice when not added. It is understood that the increase in MFR is greatly suppressed as compared with the test piece of Example 4 (Example 4, which is recycled twice). That is, it shows that by adding a hydrolysis inhibitor at the time of recycling, hydrolysis is suppressed and material recycling can be repeated as a high-quality member.

  From the above, it is understood that the conditions for material recycling of a thermoplastic resin containing a biomass-derived thermoplastic resin component must include at least the hydrolysis inhibitor in the thermoplastic resin. Furthermore, as understood from Example 5, it is understood that it is preferable to add a hydrolysis inhibitor during material recycling. Here, if material recycling of a thermoplastic resin molded article containing a thermoplastic resin component derived from biomass is taken into consideration, a hydrolysis inhibitor sufficient to withstand long-term use of the molded article after material recycling is preliminarily used. It may be added.

  The embodiments and examples disclosed herein are illustrative in all respects and should not be construed as being 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.

It is a schematic flowchart which shows a preferable example of the recycling method of this invention. It is a schematic flowchart for producing the sample which material-recycled from the resin of 0 times of recycling.

Claims (24)

  A thermoplastic resin composition comprising a thermoplastic resin component (A) derived from a fossil resource, a thermoplastic resin component (B) derived from biomass, and a hydrolysis inhibitor (C).   The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin component (A) contains a polyolefin-based thermoplastic resin as a main component.   The thermoplastic resin composition according to claim 1 or 2, wherein the thermoplastic resin component (B) contains a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid.   The said hydrolysis inhibitor (C) is a carbodiimide compound, and contains 0.01-10 weight part with respect to 100 weight part of thermoplastic resin components (B), The any one of Claims 1-3 characterized by the above-mentioned. The thermoplastic resin composition described in 1.   The thermoplastic resin composition according to claim 1, further comprising a modifier and / or an antioxidant.   The said modifier contains the block copolymer which combined the polylactic acid polymer and aliphatic polyester which have L-lactic acid and / or D-lactic acid as a main component, and aliphatic polyester. Thermoplastic resin composition.   The thermoplastic resin composition according to claim 5 or 6, wherein the modifier contains a block copolymer containing a polyolefin resin component and a polystyrene resin component as constituent units.   The thermoplastic resin composition according to any one of claims 5 to 7, wherein the modifier includes a modified polymer containing an olefin containing a carboxylic acid group or a derivative group thereof as a structural unit.   The antioxidant includes a phenol-based antioxidant and a phosphorus-based antioxidant, and the phenol-based antioxidant and the phosphorus-based antioxidant are each 0.01 to 100 parts by weight in a thermoplastic resin composition. 5 parts by weight is contained, The thermoplastic resin composition according to any one of claims 5 to 8.   The thermoplastic resin composition according to any one of claims 1 to 9, wherein the thermoplastic resin component (A) and / or the thermoplastic resin component (B) is a thermoplastic resin recovered from waste. object.   The thermoplastic resin molded object which consists of a thermoplastic resin composition in any one of Claims 1-10.   The thermoplastic resin molded body according to claim 11, which has a pellet shape.   It is used for any of an air conditioner, a television, a refrigerator, or a washing machine, The thermoplastic resin molding of Claim 11 characterized by the above-mentioned.   A method for producing a thermoplastic resin molded article, wherein the thermoplastic resin composition according to any one of claims 1 to 10 is molded into a specific shape. A resin recovery step of separating and recovering the thermoplastic resin from the waste, and a molded body manufacturing step of manufacturing a thermoplastic resin molded body from the separated and recovered thermoplastic resin,
The molded body manufacturing process includes a mixing process of adding and mixing a hydrolysis inhibitor to the separated and recovered thermoplastic resin, and a heating and melting process of heating and melting the mixture. Recycling method.   The method according to claim 15, wherein the thermoplastic resin separated and recovered from the waste is a fossil resource-derived thermoplastic resin and / or a biomass-derived thermoplastic resin.   The method according to claim 16, wherein the fossil resource-derived thermoplastic resin is mainly composed of a polyolefin-based thermoplastic resin.   The method according to claim 16 or 17, wherein the biomass-derived thermoplastic resin includes a polylactic acid polymer mainly composed of L-lactic acid and / or D-lactic acid.   The said hydrolysis inhibitor is a carbodiimide compound, and contains 0.01-10 weight part with respect to 100 weight part of said thermoplastic resins derived from biomass, The any one of Claims 16-18 characterized by the above-mentioned. Method.   The method according to any one of claims 15 to 19, wherein in the mixing step, a modifier and / or an antioxidant are further added and mixed.   The said modifier contains the block copolymer which combined the polylactic acid polymer and aliphatic polyester which have L-lactic acid and / or D-lactic acid as a main component, and characterized by the above-mentioned. Method.   The method according to claim 20 or 21, wherein the modifier comprises a block copolymer containing a polyolefin resin component and a polystyrene resin component as constituent units.   The method according to any one of claims 20 to 22, wherein the modifier comprises a modified polymer containing an olefin containing a carboxylic acid group or a derivative group thereof as a structural unit.   The antioxidant includes a phenol-based antioxidant and a phosphorus-based antioxidant, and the phenol-based antioxidant and the phosphorus-based antioxidant are separated from the separated and recovered thermoplastic resin, the hydrolysis inhibitor, and the modified agent. The method according to any one of claims 20 to 23, wherein 0.01 to 5 parts by weight are contained in a total of 100 parts by weight of the quality agent and the antioxidant.

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