JP2017171774A - Recycled thermoplastic resin composition and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recycled thermoplastic resin composition which contains a used ABS resin and has less gas generation causing gumming.SOLUTION: A recycled thermoplastic resin composition contains 100 pts.mass of an ABS resin and 1 pts.mass or more and 5 pts.mass or less of the total of at least one of a polyether-amide copolymer and a styrene-diene copolymer. The ABS resin contains 20 mass% or more and 100 mass% or less of the used ABS resin.SELECTED DRAWING: None

Description

  The present invention relates to a recycled thermoplastic resin composition and a method for producing the same.

  JP 2013-064043 A (Patent Document 1) discloses a resin composition that is unlikely to deteriorate even when reused. The resin composition is composed of a thermoplastic elastomer resin and a styrene butadiene copolymer resin with respect to 100 parts by mass of a resin composed of 15% by mass to 85% by mass of polystyrene resin and 15% by mass to 85% by mass of ABS resin. It is characterized by blending at least one of them in a range from 5 parts by mass to 20 parts by mass.

JP 2013-064043 A (Abstract)

  From the viewpoint of reducing environmental impact and effective use of resources, efforts are being made to collect and reuse used thermoplastic resins from used home appliances and OA equipment.

  As thermoplastic resins currently used for housings, parts and the like of home appliances, for example, acrylonitrile-butadiene-styrene (ABS) resin, acrylonitrile-styrene (AS) resin Polypropylene (PP) resin, Polyethylene (PE) resin, General Purpose Polystyrene (GPPS) resin, High Impact Polystyrene (HIPS) resin, and the like.

  Examples of thermoplastic resins used for OA equipment and computer casings, parts, etc. include ABS resin and AS resin, polycarbonate (PC) resin, polycarbonate-acrylonitrile resin, flame retardant resin, and the like. .

  Used thermoplastic resin is collected as shredder dust from used home appliances and OA equipment. Shredder dust is a mixture of multiple types of resin, rubber, metal, and the like. Therefore, shredder dust cannot be used as it is because of problems such as physical properties and foreign matters. Therefore, the shredder dust is separated into polyolefin, polystyrene, acrylonitrile, polycarbonate and the like with high accuracy and high purity.

  However, it is difficult to completely remove foreign substances from the used thermoplastic resin. Due to foreign matter remaining without being removed, recycled thermoplastic resin regenerated from used thermoplastic resin has impact characteristics (for example, “Charpy impact strength”) and elongation characteristics (for example, “tensile elongation at break”). It is known to be significantly inferior to new materials (unused materials).

  Currently, the recycled thermoplastic resin is once melted and passed through a screen mesh of an extruder to reduce foreign matters. It has been found that this method can improve the impact and elongation properties of recycled thermoplastic resins.

  Furthermore, in the application of recycled thermoplastic resins to designable parts, studies have been made to conceal foreign matter using pigments or the like. Further, in the application of recycled thermoplastic resin to structural parts, for example, additives that improve mechanical properties are being studied.

  However, even if the above measures are taken, it has been found that the recycled thermoplastic resin has problems to be improved. That is, the recycled thermoplastic resin generates a very small amount of gas during molding. Since this gas is very small, it does not immediately contaminate the molding die. However, this gas becomes a spear at every molding and adheres to the molding die and accumulates. The transferability of the molding die gradually decreases due to the accumulation of the eyes. As a result, for example, in the molding die in which the recycled thermoplastic resin is molded 1000 times or more, the appearance design of the molded product may be impaired.

  Eye deposits are particularly noticeable in spent ABS resin. The used ABS resin contains a large amount of additives for extrusion molding derived from the inner box material of the refrigerator, for example. Therefore, the used ABS resin does not exhibit sufficient fluidity at a normal molding temperature (about 200 to 250 ° C.). Therefore, the molding temperature of the used ABS resin must be higher than the normal molding temperature. Thereby, it is considered that gasification of the additive is promoted.

  The present invention has been made to solve the above-described problems. That is, an object of the present invention is to provide a regenerated thermoplastic resin composition containing a used ABS resin and generating less gas that causes discoloration.

  The recycled thermoplastic resin composition according to the present invention includes 100 parts by mass of an ABS resin and 1 part by mass or more and 5 parts by mass or less in total of at least one of a polyetheramide copolymer and a styrene diene copolymer. . The ABS resin contains 20% by mass or more and 100% by mass or less of the used ABS resin.

  The inventor has analyzed in detail the spear adhering to the molding die. As a result, it was found that the eye candy is an oily component such as stearic acid and palmitic acid (hereinafter also referred to as “eye candy component”).

  In the regenerated thermoplastic resin composition of the present invention, the polyetheramide copolymer and the styrene diene copolymer are oil-absorbing components capable of adsorbing the spear component (oil-based component). Moreover, the polyetheramide copolymer and the styrene diene copolymer are incompatible with the main ABS resin. For this reason, the polyetheramide copolymer and the styrene diene copolymer retain the spear component adsorbed at the time of molding, and are difficult to release thereafter once adsorbed. Therefore, according to the polyether amide copolymer and the styrene diene copolymer, a sufficient gas generation suppressing effect can be expected with a small amount.

  However, the blending amount of the polyetheramide copolymer and the styrene diene copolymer is 1 part by mass or more and 5 parts by mass or less. If the blending amount is less than 1 part by mass, the gas generation suppressing effect may not be sufficient. If the blending amount exceeds 5 parts by mass, mechanical properties and the like may be deteriorated. This is because the polyetheramide copolymer and the styrene diene copolymer are incompatible with the ABS resin.

  As described above, according to the recycled thermoplastic resin composition of the present invention, gas generation during molding is suppressed. In other words, the adhesion and accumulation of the eyes on the molding die are suppressed. As a result, a molded product having excellent appearance design can be repeatedly produced.

  In the recycled thermoplastic resin composition of the present invention, the ABS resin may contain an unused ABS resin (new material) in a range of 80% by mass or less depending on the application.

It is a flowchart which shows the outline of the manufacturing method of the reproduction | regeneration thermoplastic resin composition which concerns on embodiment of this invention.

  Hereinafter, an embodiment of the present invention (hereinafter may be referred to as “this embodiment”) will be described. However, the present invention is not limited to the following description.

<Recycled thermoplastic resin composition>
The recycled thermoplastic resin composition of this embodiment includes 100 parts by mass of an ABS resin and 1 part by mass or more and 5 parts by mass or less in total of at least one of a polyetheramide copolymer and a styrene diene copolymer. . The ABS resin contains 20% by mass or more and 100% by mass or less of the used ABS resin.

<< ABS resin >>
ABS resin is a copolymer of acrylonitrile, butadiene, and styrene. The molded article of ABS resin is excellent in surface gloss and impact strength. Therefore, ABS resin is frequently used for home appliances, OA equipment and the like. In this embodiment, the constituent ratio of acrylonitrile, butadiene, and styrene of the ABS resin is not particularly limited.

  “Used ABS resin” refers to an ABS resin recovered from a product or the like after being used at least once for a home appliance or the like. On the other hand, an ABS resin that has not been used for home appliances or the like is referred to as an “unused ABS resin”.

  The ABS resin according to this embodiment contains 20% by mass to 100% by mass of used ABS resin. When the content of the used ABS resin is less than 100% by mass, the balance of the ABS resin becomes unused ABS resin. For example, the ABS resin contains 80% by mass of used ABS resin and 20% by mass of unused ABS resin. The content of the unused ABS resin can be appropriately changed in accordance with the use within the range of 80% by mass or less. However, from the viewpoint of resource efficiency, the smaller the content of unused ABS resin, the better. That is, the ABS resin preferably contains the used ABS resin in an amount of 25 to 100% by mass, more preferably 50 to 100% by mass, and most preferably 75 to 100% by mass. .

  The recycled thermoplastic resin composition may further contain other used thermoplastic resins as long as it contains the used ABS resin, the polyetheramide copolymer, and the styrene diene copolymer in the above-described formulation. For example, the recycled thermoplastic resin composition includes a used thermoplastic resin such as an acrylonitrile-based resin (for example, an AS resin) and a polycarbonate-acrylonitrile resin recovered from home appliances and OA equipment, as well as a used ABS resin. You may go out.

  The used thermoplastic resin may contain a filler, a reinforcing material and the like in addition to the resin component. For example, used thermoplastic resins include talc, mica, wollastonite, calcium carbonate, barium sulfate, magnesium carbonate, clay, alumina, silica, calcium sulfate, carbon fiber, glass fiber, metal fiber, silica sand, silica stone, Inorganic materials such as carbon black, titanium dioxide, zinc oxide, antimony trioxide, magnesium hydroxide, asbestos, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium hydroxide, calcium sulfite, sodium sulfate, bentonite, kaolinite, and graphite May be included.

  The used thermoplastic resin may further contain solid foreign substances that could not be removed. Many solid foreign substances are dark. The size of the solid foreign matter is often about 100 μm square or more. Specific examples of the solid foreign matter include hydrocarbon rubber, silicone rubber, urethane, metal scrap, metal oxide, and the like.

《Oil absorbing component》
In this embodiment, at least one of the polyetheramide copolymer and the styrene diene copolymer is referred to as an “oil absorbing component”.

(Polyetheramide copolymer)
The polyetheramide copolymer is produced by copolymerization of an amide monomer and an ether monomer. The polyetheramide copolymer is preferably a block copolymer comprising a polyamide block and a polyether block. In such a block copolymer, it is considered that the polyamide block constitutes a hard segment and the polyether block constitutes a soft segment. The block copolymer may contain structural units randomly dispersed in the molecule in addition to the polyamide block and the polyether block.

  Specific examples of the polyether amide copolymer that is a block copolymer include a polyether block amide copolymer and a polyether ester block amide copolymer.

The polyether block amide copolymer can be represented by the following formula (I).
HO- [CO- (PA) -CO-NH- (PE) -NH] _n -H (I)
In formula (I), (PA) represents a polyamide block. (PE) indicates a polyether block. n represents a natural number. Formula (I) shows that the structural unit enclosed by [] is repeated. The polyamide block and the polyether block may be substantially the same in all structural units, or may be different for each structural unit.

The polyether ester block amide copolymer can be represented by the following formula (II).
HO- [CO- (PA) -CO-O- (PE) -O] _n- H (II)
In formula (II), (PA) represents a polyamide block. (PE) indicates a polyether block. n represents a natural number. Formula (II) shows that the structural unit enclosed by [] is repeated. The polyamide block and the polyether block may be substantially the same in all structural units, or may be different for each structural unit.

  In the polyetheramide copolymer of this embodiment, the molar ratio of PA (polyamide block) and PE (polyether block) is not particularly limited. The molar ratio of PA to PE is, for example, about PA: PE = 1: 99 to 99: 1, and preferably about PA: PE = 20: 80 to 80:20.

  The polyetheramide copolymer of this embodiment may contain both the structural units represented by the above formulas (I) and (II), for example. That is, the polyetheramide copolymer includes at least one of a polyether block amide copolymer and a polyether ester block amide copolymer. The polyether amide copolymer is preferably a polyether block amide copolymer.

  The polyether amide copolymer as described above comprises (i) a polyamide block in which both ends of the main chain are carboxy groups, (ii) a polyamide block in which both ends of the main chain are amino groups, and (iii) It is produced by polycondensation of polyoxyalkylene having both hydroxyl groups at both ends, and (iv) a polyether block having both ends of the main chain being amino groups.

  (I) The polyamide block in which both ends of the main chain are carboxy groups is produced, for example, by condensation of a polyamide precursor (such as a lactam compound) in the presence of a dicarboxylic acid that is a chain limiter.

  (Ii) A polyamide block in which both ends of the main chain are amino groups is produced, for example, by condensation of a polyamide precursor in the presence of a diamine as a chain limiter.

  The number average molecular weight (Mn) of the polyamide block is, for example, about 400 to 20000 g / mol, and preferably about 500 to 10000 g / mol.

  The polyamide block is produced, for example, by condensation of a dicarboxylic acid and an aliphatic or aromatic diamine.

  The dicarboxylic acid has, for example, 4 to 20 carbon atoms, preferably 6 to 18 carbon atoms. Specific examples of the dicarboxylic acid include, for example, 1,4-cyclohexyldicarboxylic acid, butanedioic acid, adipic acid, azelaic acid, corkic acid, sebacic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, terephthalic acid, isophthalic acid, and dimer Fatty acid and the like.

  The diamine has, for example, 2 to 20 carbon atoms, preferably 6 to 14 carbon atoms. Specific examples of the diamine include, for example, tetramethylene diamine, hexamethylene diamine, 1,10-decamethylene diamine, dodecamethylene diamine, trimethyl hexamethylene diamine, bis (4-aminocyclohexyl) methane isomer, bis (3- Methyl-4-aminocyclohexyl) methane isomer, 2,2-bis (3-methyl-4-aminocyclohexyl) propane isomer, p-aminodicyclohexylmethane, isophoronediamine, 2,6-bis (aminomethyl) Examples include norbornane and piperazine.

  Therefore, the polyamide constituting the polyamide block includes polyamide 6, polyamide 11, polyamide 12, polyamide 66, polyamide 412, polyamide 414, polyamide 418, polyamide 610, polyamide 612, polyamide 614, polyamide 618, polyamide 912, polyamide 1010, Examples thereof include polyamide 1012, polyamide 1014, and polyamide 1018.

  (Iii) Examples of the polyoxyalkylene in which both ends of the main chain are hydroxyl groups include glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polyhexamethylene glycol.

  (Iv) Examples of the polyether in which both ends of the main chain are amino groups include polyether diamines such as poly (ethylene glycol) diamine.

(Styrene diene copolymer)
The styrene diene copolymer is produced by copolymerization of a styrene monomer and a diene monomer. The styrene diene copolymer is preferably a block copolymer comprising a polystyrene block and a polydiene block. That is, the styrene diene copolymer is preferably a styrene diene block copolymer.

  Examples of the styrene monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, isobutylstyrene, t-butylstyrene, o-bromostyrene, m- Examples include bromostyrene, p-bromostyrene, o-chlorostyrene, m-chlorostyrene, and p-chlorostyrene. Of these, styrene is preferred. Styrene is easy to polymerize because of its good reactivity.

  Examples of the diene monomer include butadiene, chloroprene, isoprene, 1,3-pentadiene and the like. Of these, butadiene is preferred. This is because butadiene is excellent in reactivity. That is, the styrene diene copolymer is preferably a styrene butadiene copolymer, and more preferably a styrene butadiene block copolymer.

  In the styrene diene copolymer, the constituent ratio of the styrene structural unit is not particularly limited. However, in the case of a styrene butadiene block copolymer, the constituent ratio of the styrene constituent unit is preferably about 30 to 50% by mass. In such a range, improvement in mechanical properties (for example, impact strength) can be expected.

(Incompatible)
The polyether amide copolymer and the styrene diene copolymer are incompatible with the ABS resin. Therefore, it is considered that the polyether amide copolymer and the styrene diene copolymer do not readily release the once adsorbed component. An SP value can be given as one indication of incompatibility. The SP value of the polyetheramide copolymer and the styrene diene copolymer is preferably, for example, a value that is 1.0 or more away from the SP value (about 9.6 to 10.1) of the ABS resin.

(Amount of oil absorption component)
The adsorbing component exhibits a high adsorbing ability with respect to the spear component of this embodiment. When the recycled thermoplastic resin composition contains 1 part by mass or more and 5 parts by mass or less of oil-absorbing components in total, gas generation during molding can be suppressed. This is probably because the oil-absorbing component adsorbs the spear component that causes gas generation. The oil absorbing component is preferably 2 parts by mass or more and 4 parts by mass or less. This is because in such a range, the gas generation suppressing effect is high and the influence on the mechanical characteristics is small.

(Eye component)
Examples of the spider component that can be adsorbed by the oil-absorbing component of this embodiment include hexane, heptene, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, and nonadecane. Hydrocarbons; fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, and palmitoleic acid; higher alcohols such as cetyl alcohol, stearyl alcohol, and oleyl alcohol; stearic acid amide, oleic acid amide, erucic acid amide And fatty acid amides such as hexadecanamide; squalene; and; bisphenol A and the like.

"Antioxidant"
The recycled thermoplastic resin composition preferably further contains an antioxidant.
Among the foreign substances mixed in the recycled thermoplastic resin, there is a substance that oxidizes the resin component. For example, metals such as copper, iron, and aluminum have a strong oxidizing power for the resin component. For example, oxidative decomposition of a resin with copper is known as “copper damage”. In addition, some of the metal scraps, metal oxides, and dissimilar resins promote the oxidation of the resin component. Due to these actions, there is a possibility that the appearance design of a molded product produced from the recycled thermoplastic resin composition is impaired. Alternatively, the mechanical properties of the molded product may be deteriorated. Therefore, it is conceivable to suppress oxidation of the resin component with an antioxidant.

  The recycled thermoplastic resin composition preferably contains a phosphoric acid-based antioxidant, a sulfur-based antioxidant, and a hindered phenol-based antioxidant. More preferably, the recycled thermoplastic resin composition contains 0.05 parts by weight or more and 1 part by weight or less of a phosphate-based antioxidant or sulfur-based antioxidant and a hindered phenol-based antioxidant in total. Within such a range, it is possible to suppress the oxidation of the resin component while suppressing a decrease in mechanical properties and the like. The phosphoric acid antioxidant or sulfur antioxidant and the hindered phenol antioxidant are preferably the same amount. Further, the total amount of the antioxidant is more preferably 0.1 parts by mass or more and 1 part by mass or less.

  Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-p-cresol, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl). ) Propionate] methane, stearyl β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-) Butyl-4-hydroxybenzyl) benzene, triethylene glycol bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] and the like. Of these, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane and stearyl β- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate is excellent in terms of thermal stability. A hindered phenolic antioxidant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the phosphoric acid antioxidant include tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4, 4'-diylbisphosphonite, bis [2,4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, bis (2,4-di-t-butylphenyl) penta Examples include erythritol diphosphite, triallyl phosphite, and tri (monononylphenyl) phosphite. Of these, tris (2,4-di-t-butylphenyl) phosphite is excellent in terms of thermal stability. A phosphoric acid type antioxidant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the sulfur-based antioxidant include dilauryl-3,3'-thiodipropionate and dioctadecyl-3,3'-thiodipropionate. Of these, dioctadecyl-3,3'-thiodipropionate is excellent in terms of thermal stability. A sulfur type antioxidant may be used individually by 1 type, and may be used in combination of 2 or more type.

<< Other ingredients (additives, etc.) >>
The recycled thermoplastic resin composition is an oil-absorbing inorganic compound, a flow regulator, a plasticizer, a mold release agent, a flame retardant, a flame retardant aid, a metal deactivator, a dye, as long as the purpose of this embodiment is not impaired. A pigment, an antistatic agent, or the like may be contained. These components may be contained alone in the recycled thermoplastic resin composition, or may be contained in combination of two or more.

(Oil-absorbing inorganic compounds)
The recycled thermoplastic resin composition preferably contains 0.5 to 5 parts by mass (more preferably 1 to 2 parts by mass) of the oil-absorbing inorganic compound.

  Examples of the oil-absorbing inorganic compound include aluminum oxide such as alumina and boehmite, calcium silicate, kaolinite, and calcium carbonate. The oil-absorbing inorganic compound can adsorb the spear component. Therefore, when the recycled thermoplastic resin composition contains an oil-absorbing inorganic compound, there is a possibility that gas generation during molding can be further reduced.

  The oil absorbing inorganic compound preferably has an oil absorption of 50 ml / 100 g or more. Thereby, improvement of the gas generation suppression effect can be expected. The “oil absorption amount” in the present specification indicates a value measured in accordance with “JIS K5101-13-1” or “JIS K5101-13-2”. When there is a difference between the values measured by these two methods, the value measured by “JIS K5101-13-1” is adopted.

The oil-absorbing inorganic compound preferably has a specific surface area of 1 m ² / g or more. Thereby, improvement of the gas generation suppression effect can be expected. The “specific surface area” in the present specification indicates a specific surface area determined by a BET (Brunauer, Emmet and Teller) method. Nitrogen is used as the measurement gas.

Aluminum oxide is represented by the chemical formula Al ₂ O ₃ . Aluminum oxide is an amphoteric oxide. Aluminum oxide is produced, for example, by firing aluminum hydroxide. Aluminum oxide is a white powder crystal.

  Examples of aluminum oxide include various forms such as α-alumina, δ-alumina, θ-alumina, and κ-alumina. Further, there are forms such as colloidal alumina and fumed alumina produced by a specific manufacturing method. In this embodiment, any form can be adopted. A plurality of aluminum oxides having different forms may be used in combination. However, hexagonal α-alumina is preferable from the viewpoint of oil absorption.

The specific surface area of the powder material increases as the particle size decreases. In order for the oil-absorbing inorganic compound to exhibit a desired oil absorption capacity, the specific surface area is preferably 1 m ² / g or more. The average particle diameter of α-alumina is preferably 0.01 to 50 μm, more preferably 0.1 to 1.0 μm. With such an average particle size, α-alumina can satisfy an oil absorption of 50 ml / 100 g or more and a specific surface area of 1 m ² / g or more.

For example, α-alumina having an average particle size of 1.0 μm, an oil absorption of 50 ml / 100 g, and a specific surface area of 5.4 m ² / g may be used. For example, α-alumina having an average particle diameter of 0.8 μm, an oil absorption of 60 ml / 100 g, and a specific surface area of 5.9 m ² / g may be used. The “average particle size” in the present specification indicates a total particle size of 50% from the fine particle side in the volume-based particle size distribution measured by the laser diffraction / scattering method.

Boehmite is a monohydrate of alumina. Boehmite is represented by the chemical formula AlOOH or the chemical formula Al ₂ O ₃ .H ₂ O. Boehmite is an orthorhombic white powder. Boehmite preferably has an average particle size of 0.01 to 50 μm, more preferably 0.1 to 5.0 μm. In such a range, boehmite can satisfy an oil absorption of 50 ml / 100 g or more and a specific surface area of 1 m ² / g or more.

For example, boehmite having an average particle diameter of 0.1 μm, an oil absorption amount of 220 ml / 100 g, and a specific surface area of 110 m ² / g may be used. For example, boehmite having an average particle diameter of 0.7 μm, an oil absorption of 84 ml / 100 g, and a specific surface area of 16 m ² / g may be used. For example, boehmite having an average particle diameter of 2.3 μm, an oil absorption of 60 ml / 100 g, and a specific surface area of 3.0 m ² / g may be used.

Calcium silicate is a general term for compounds in which calcium oxide (CaO), silicon dioxide (SiO ₂ ) and water are combined in various proportions. Calcium silicate is synthesized, for example, by hydrothermal reaction using quick lime, wollastonite, and water as main raw materials. Among calcium silicates, zonorite (6CaO · 6SiO ₂ · H ₂ O) which is a fibrous crystal and tobermorite (5CaO · 6SiO ₂ · 5H ₂ O) which is a strip-like crystal are preferable.

Zonolite preferably has an average particle size of 0.01 to 50 μm, more preferably 1 to 50 μm. In such a range, zonolite can satisfy an oil absorption of 50 ml / 100 g or more and a specific surface area of 1 m ² / g or more.

Tobermorite preferably has an average particle size of 0.01 to 50 μm, more preferably 1 to 50 μm. For example, tobermorite having an average particle diameter of 24 μm, an oil absorption amount of 620 ml / 100 g, and a specific surface area of 56 m ² / g may be used. For example, tobermorite having an average particle diameter of 17 μm, an oil absorption of 440 ml / 100 g, and a specific surface area of 55 m ² / g may be used. For example, tobermorite having an average particle diameter of 47 μm, an oil absorption of 480 ml / 100 g, and a specific surface area of 50 m ² / g may be used.

  Kaolinite is a kind of silicate mineral. Kaolinite is triclinic. The name of kaolinite is derived from China's Kaolin, which is the production area of clay. Kaolinite includes wet kaolinite and calcined kaolinite. Wet kaolinite is kaolinite from which impurities have been removed by purification and bleaching using water. Wet kaolinite has high whiteness.

  Firing kaolinite is kaolinite from which water of crystallization has been removed by firing the wet kaolinite. Since organic substances are decomposed by the firing treatment, the fired kaolinite has higher whiteness. Since the fired kaolinite has a high whiteness, it has excellent hiding power. In addition, calcined kaolinite is also excellent in weather resistance. For this reason, calcined kaolinite is used in paints, pigments, rubber, plastics, cosmetics and the like.

Kaolinite preferably has an average particle size of 0.01 to 50 μm, more preferably 0.1 to 10 μm. In such a range, kaolinite can satisfy an oil absorption of 50 ml / 100 g or more and a specific surface area of 1 m ² / g or more. For example, kaolinite having an average particle diameter of 0.7 μm, an oil absorption of 120 ml / 100 g, and a specific surface area of 15 m ² / g may be used. For example, kaolinite having an average particle size of 1.5 μm, an oil absorption of 60 ml / 100 g, and a specific surface area of 9.0 m ² / g may be used. For example, kaolinite having an average particle diameter of 0.3 μm, an oil absorption of 62 ml / 100 g, and a specific surface area of 4.0 m ² / g may be used.

  Calcium carbonate is a carbonate of calcium. Calcium carbonate is a main component of, for example, shells, cocoon skeletons, egg shells, limestone, marble, stalactites, chalk. Calcium carbonate is a colorless crystal or a white powder. Calcium carbonate is hardly soluble in neutral water. However, calcium carbonate reacts with strong acids such as hydrochloric acid to release carbon dioxide.

  In general, calcium carbonate is synthesized by reacting calcium hydroxide with calcium hydroxide. Solid crystals of calcium carbonate have polymorphs such as rhombohedral, trigonal (for example, produced as calcite), and orthorhombic (for example, produced as meteorite). At normal temperature and pressure, the trigonal system tends to be stable. In addition, hexagonal vaterite is also known. But the vaterite is unstable.

  Calcium carbonate includes heavy calcium carbonate produced by pulverizing and classifying natural raw materials (such as limestone) and precipitated calcium carbonate produced by chemical reaction (also referred to as “light calcium carbonate”). is there. When precipitated calcium carbonate is produced at room temperature, a trigonal system is first generated. When the solution is then boiled, an orthorhombic system precipitates. This orthorhombic system easily changes to a trigonal system when left untreated.

The average particle diameter of calcium carbonate is preferably 0.01 to 50 μm, more preferably 0.1 to 10 μm. In such a range, calcium carbonate can satisfy an oil absorption of 50 ml / 100 g or more and a specific surface area of 1 m ² / g or more. For example, calcium carbonate having an average particle diameter of 1.2 μm, an oil absorption of 60 ml / 100 g, and a specific surface area of 3.0 m ² / g may be used. For example, calcium carbonate having an average particle diameter of 1.5 μm, an oil absorption of 70 ml / 100 g, and a specific surface area of 3.5 m ² / g may be used. For example, calcium carbonate having an average particle size of 0.15 μm, an oil absorption of 53 ml / 100 g, and a specific surface area of 12 m ² / g may be used.

  In addition, you may use together carbon oil which is a black pigment, talc, a silica, etc. which are inorganic fillers to said oil-absorbing inorganic compound (alumina etc.). Carbon black has an average particle diameter of preferably 0.001 to 1 μm, and more preferably 10 to 200 nm. Talc preferably has an average particle size of 1 μm or less. Silica preferably has an average particle size of 20 μm or less.

(Fluidity modifier)
The fluidity modifier is used to adjust the fluidity during molding. The fluidity modifier is also used as a plasticizer and lubricant for resin components.

  Examples of fluidity modifiers include: hydrocarbons such as liquid paraffin, paraffin wax and synthetic polyethylene wax; fatty acids such as stearic acid, palmitic acid and oleic acid; higher alcohols such as stearyl alcohol, cetyl alcohol and oleyl alcohol; stearic acid Fatty acid amides such as amide, oleic acid amide, erucic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide; metal soaps such as magnesium stearate, calcium stearate, zinc stearate; stearic acid monoglyceride, stearyl stearate, cured And esters such as oil;

  Of these, fatty acids, higher alcohols, aliphatic amides, esters, and the like are frequently used to adjust the fluidity of unused thermoplastic resins (new materials). Therefore, many of these components remain in the used thermoplastic resin. In order to suppress gas generation during molding, it is desirable that the amount of the compound that volatilizes around the molding temperature (about 180 to 270 ° C.) of the recycled thermoplastic resin composition is as small as possible.

  That is, it is desirable to use a compound that hardly volatilizes in the vicinity of the aforementioned molding temperature as the fluidity modifier. For example, paraffin wax, methylene bis stearamide, ethylene bis stearamide, magnesium stearate, calcium stearate, stearic acid monoglyceride, stearyl stearate, hydrogenated oil and the like are suitable.

(Plasticizer)
The plasticizer is not particularly limited. In this embodiment, a conventionally known plasticizer can be used. Examples of the plasticizer include polyethylene glycol, polyamide oligomer, ethylene bisstearamide, phthalic acid ester, adipic acid ester, polystyrene oligomer, polyethylene wax, silicone oil, mineral oil, and the like.

(Release agent)
The release agent is not particularly limited. In this embodiment, a conventionally known release agent can be used. Examples of the release agent include polyethylene wax, silicone oil, long chain carboxylic acid, and long chain carboxylic acid metal salt.

(Flame retardants)
The flame retardant is not particularly limited. In this embodiment, a conventionally known flame retardant can be used. Examples of the flame retardant include: phosphorus-based flame retardants such as tricresyl phosphate, triphenyl phosphate, tris-3-chloropropyl phosphate; 2,2-bis [4- (2,3-dibromopropoxyl) -3, Brominated flame retardants such as 5-dibromophenyl] propane, bis (3,5-dibromo-4-dibromopropyloxyphenyl) sulfone, ethylenebispentabromobenzene, hexabromocyclododecane; silicone-based flame retardants; magnesium hydroxide, Hydroxide hydroxide flame retardants such as aluminum hydroxide; and the like.

(Flame retardant aid)
In order to enhance the flame retardant effect of the flame retardant, a flame retardant aid may be used in combination. Examples of the flame retardant aid include antimony compounds such as antimony trioxide.

(Metal deactivator)
In order to suppress the oxidizing power of the metal component contained in the recycled thermoplastic resin composition, a metal deactivator may be blended. Examples of the metal deactivator include 2 ′, 3-bis [[3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionyl]] propionohydrazide, 3- (N-salicyloyl) amino. -1,2,4-triazole, decamethylenedicarboxylic acid disalicyloyl hydrazide, N-formyl salicyloyl hydrazine, benzotriazole, methylbenzotriazole, methylbenzotriazole potassium salt, N, N-dibenzal (oxalyl hydrazide ), N, N-bis (3,5-di-t-butyl-4-hydroxyhydrocinnamate) and the like. Of these, decamethylene dicarboxylic acid disalicyloyl hydrazide is superior in terms of thermal stability.

<Method for Producing Recycled Thermoplastic Resin Composition>
The recycled thermoplastic resin composition of this embodiment can be produced, for example, by the following production method.

  FIG. 1 is a flowchart showing an outline of a method for producing a recycled thermoplastic resin composition of this embodiment. As shown in FIG. 1, the manufacturing method includes a preparation step (S10) and a mixing step (S20).

<< Preparation process (S10) >>
In the preparation step (S10), a used ABS resin is prepared. Used ABS resin is collected from used home appliances, OA equipment, and the like.

  The preparation step (S10) preferably includes at least one of a density selection step (S01) and a surface polishing step (S02). In the preparation step (S10), either the density selection step (S01) or the surface polishing step (S02) may be executed, or both the density selection step (S01) and the surface polishing step (S02) are executed. May be. When both the density sorting step (S01) and the surface polishing step (S02) are executed, the execution order is not particularly limited, and either may be executed first.

(Tint selection process (S01))
In the density selection step (S01), the used ABS resin whose surface color brightness exceeds a predetermined threshold is selected based on the density of the surface color of the used ABS resin. Here, “brightness” indicates a value in which the brightness between white and black is expressed as a ratio to white, where the brightness of white is 100% and the brightness of black is 0%. The brightness can be detected by, for example, a CCD (Charge Couple Device) camera. By performing the density selection step (S01), an improvement in appearance design can be expected in a molded product produced from the recycled thermoplastic resin composition.

  The lightness threshold is preferably 75%. That is, in the density selection step (S01), preferably, the used ABS resin having a surface color brightness exceeding 75% is selected based on the density of the surface color of the used ABS resin.

  As a specific operation in the density selection step (S01), a used ABS resin containing light-absorbing pigments and dark foreign matters whose lightness is not more than a predetermined threshold is detected by a CCD camera and removed. Thereby, the used ABS resin exceeding a predetermined brightness can be selected and collected. The light absorbing pigment is typically carbon black.

  A method for removing the light-absorbing pigment and the dark foreign matter is, for example, as follows. First, the used ABS resin is transported to the measurement area using a transport device such as a belt conveyor. The brightness of the surface color of the used ABS resin is detected by a CCD camera or the like, and if the brightness is equal to or less than a threshold value, the used ABS resin is shot down by an air gun (ejector) nozzle. Thereby, the used ABS resin containing a light absorptive pigment and a dark color foreign material can be removed.

(Surface polishing step (S02))
In the surface polishing step (S02), the used ABS resin is rubbed against each other to reduce dark foreign matter in the used ABS resin. That is, all or part of the dark colored foreign matter adhering to the surface of the used ABS resin is removed by friction and polishing. By performing the surface polishing step (S02), an improvement in appearance design can be expected in a molded product produced from the recycled thermoplastic resin composition. The surface polishing step (S02) may involve cutting with a cutter.

  In the surface polishing step (S02), it is preferable to rub and polish the surface of the used ABS resin so that the yield is 90% or more and 97% or less. If the yield is less than 90%, there are many losses in this process, which is uneconomical. If the yield exceeds 97%, the removal of foreign matter may be insufficient.

<< Mixing step (S20) >>
In the mixing step (S20), 100 parts by mass of ABS resin containing 20% by mass or more and 100% by mass or less of the used ABS resin, and at least one of the polyetheramide copolymer and the styrene diene copolymer in total 1 mass. To 5 parts by mass or more. At this time, an antioxidant may be added to the mixture. Furthermore, you may add another component (an oil-absorbing inorganic compound, a fluidity modifier etc.) to a mixture as needed.

  At the time of mixing, used ABS resin, polyether amide copolymer, styrene diene copolymer, antioxidant, and the like are used, for example, in the form of powder or granules.

  The mixing method is not particularly limited. For example, physical mixing such as melt kneading, solvent cast blending, latex blending, and polymer complex can be performed. The mixing is preferably melt kneading.

  In the mixing step (S20), a mixing device such as a tumbler, a Henschel mixer (registered trademark), a rotary mixer, a super mixer, a ribbon tumbler, or a V blender can be used. A mixture is prepared in advance by mixing the materials uniformly using these mixing devices. Further, it is preferable to carry out melt kneading and finally form pellets.

  For melt-kneading and pelletizing, a single-screw type, multi-axis type, tandem type or the like can be used. Alternatively, a Banbury mixer, a roller, a conida, a blast mill, a Plavender brow graph, or the like may be used. The operation of the extrusion kneader or the like may be a batch type or a continuous type.

  Alternatively, a mixture is prepared by mixing a used ABS resin, a polyether amide copolymer, a styrene diene copolymer, an antioxidant and the like without performing melt kneading. The mixture may be supplied to a molding machine and melt kneaded in a heating cylinder of the molding machine. That is, mold blending may be performed.

  The recycled thermoplastic resin composition of this embodiment can be processed into a molded product by a conventionally known molding method. The molding method is, for example, an injection molding method.

  Hereinafter, the embodiment will be described in more detail with reference to examples. However, this embodiment is not limited to the following example.

<Production of recycled thermoplastic resin composition>
Various recycled thermoplastic resin compositions were produced as follows.

Example 1
Used ABS resin was collected from used home appliances. Thus, a used ABS resin was prepared (S10).

  A polyether block amide copolymer was prepared as a polyether amide copolymer. Stearyl β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate was prepared as a hindered phenol antioxidant. Tris (2,4-di-t-butylphenyl) phosphite was prepared as a phosphoric acid antioxidant. A mixture was prepared by mixing the materials with the following formulation (S20).

Used ABS resin 100 parts by weight Polyether block amide copolymer 5 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

  The mixture was fed to the extruder. In the extruder, the mixture was melt-kneaded while being heated at 240 ° C. to produce pellets (regenerated thermoplastic resin composition). The size of the pellet is about 3 to 5 mm. The pellets were supplied to an injection molding machine, and a flat plate test piece for measuring glossiness was molded at a molding temperature of 240 ° C. and a mold temperature of 60 ° C. The dimension of the flat plate test piece is 100 mm long × 100 mm wide × 2 mm thick. Further, for the Charpy impact test described later, a multipurpose test piece A type conforming to “JIS K7139” was molded under the same molding conditions. Hereinafter, the flat plate test piece and the multipurpose test piece A type may be collectively referred to as “test piece”.

Example 2
A styrene butadiene block copolymer was prepared as a styrene diene copolymer. A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Example 2 were produced in the same manner as in Example 1.

Used ABS resin 100 parts by weight Styrene butadiene block copolymer 5 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

Example 3
A recycled thermoplastic resin composition and a test piece according to Example 3 were produced in the same manner as in Example 1 except that the blending amount of the polyether block amide copolymer was changed to 1 part by mass.

Example 4
A recycled thermoplastic resin composition and a test piece according to Example 4 were produced in the same manner as in Example 2 except that the blending amount of the styrene butadiene block copolymer was changed to 1 part by mass.

Example 5
Kaolinite was prepared as an oil-absorbing inorganic compound. Paraffin wax was prepared as a fluidity modifier. A mixture was prepared by mixing the materials in the following formulation. A recycled thermoplastic resin composition and a test piece according to Example 5 were produced in the same manner as Example 1 except for these.

Used ABS resin 100 parts by weight Polyether block amide copolymer 3 parts by weight Styrene butadiene block copolymer 2 parts by weight Kaolinite 0.5 part by weight Paraffin wax 0.5 part by weight Hindered phenol antioxidant 0.05 Parts by mass Phosphate-based antioxidant 0.05 parts by mass

Example 6
Calcium silicate was prepared as an oil absorbing inorganic compound. A mixture was prepared by mixing the materials in the following formulation. A recycled thermoplastic resin composition and a test piece according to Example 6 were produced in the same manner as Example 1 except for these.

Used ABS resin 100 parts by weight Polyether block amide copolymer 1 part by weight Styrene butadiene block copolymer 2 parts by weight Calcium silicate 1 part by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 parts by mass

Example 7
Boehmite was prepared as an oil-absorbing inorganic compound. A mixture was prepared by mixing the materials in the following formulation. A recycled thermoplastic resin composition and a test piece according to Example 7 were produced in the same manner as Example 1 except for these.

Used ABS resin 100 parts by weight Polyether block amide copolymer 0.5 part by weight Styrene butadiene block copolymer 0.5 part by weight Boehmite 2 parts by weight Hindered phenol antioxidant 0.05 part by weight Phosphoric acid oxidation 0.05 parts by weight of inhibitor

Example 8
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Example 8 were produced in the same manner as in Example 1.

Used ABS resin 100 parts by weight Polyether block amide copolymer 3 parts by weight Kaolinite 0.5 part by weight Calcium silicate 0.5 part by weight Boehmite 0.5 part by weight Paraffin wax 0.5 part by weight Hindered phenol oxidation Inhibitor 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

Example 9
Unused ABS resin (new material) was prepared. A mixture was prepared by mixing the materials in the following formulation. A recycled thermoplastic resin composition and a test piece according to Example 9 were produced in the same manner as Example 1 except for these.

Used ABS resin 50 parts by weight Unused ABS resin 50 parts by weight Polyether block amide copolymer 5 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

Example 10
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Example 10 were produced in the same manner as in Example 4.

Used ABS resin 25 parts by weight Unused ABS resin 75 parts by weight Styrene butadiene block copolymer 1 part by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

Example 11
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Example 11 were produced in the same manner as in Example 1 and the like.

Used ABS resin 25 parts by weight Unused ABS resin 75 parts by weight Polyether block amide copolymer 2 parts by weight Styrene butadiene block copolymer 3 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 parts by weight of agent

Example 12
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Example 12 were produced in the same manner as in Example 1 and the like.

Used ABS resin 20 parts by weight Unused ABS resin 80 parts by weight Polyether block amide copolymer 1 part by weight Styrene butadiene block copolymer 3 parts by weight Kaolinite 1 part by weight Calcium silicate 1 part by weight Hindered phenolic antioxidant 0.05 parts by weight Phosphoric antioxidant 0.05 parts by weight

Example 13
A mixture was prepared by mixing the materials in the following formulation. A recycled thermoplastic resin composition and a test piece according to Example 13 were produced in the same manner as Example 1 except for the above.

Used ABS resin 100 parts by mass Polyether block amide copolymer 5 parts by mass Hindered phenol-based antioxidant 0.50 parts by mass Phosphoric acid-based antioxidant 0.50 parts by mass

Example 14
A mixture was prepared by mixing the materials in the following formulation. A recycled thermoplastic resin composition and a test piece according to Example 14 were produced in the same manner as Example 9 except for the above.

Used ABS resin 50 parts by weight Unused ABS resin 50 parts by weight Polyether block amide copolymer 5 parts by weight Hindered phenol-based antioxidant 0.50 parts by weight Phosphate-based antioxidant 0.50 parts by weight

<< Comparative Example 1 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 1 were produced in the same manner as in Example 1. Comparative Example 1 is an example in which the regenerated thermoplastic resin composition does not contain a polyetheramide copolymer and a styrene diene copolymer.

Used ABS resin 100 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

<< Comparative Example 2 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 2 were produced in the same manner as in Example 1. In Comparative Example 2, the total of the polyetheramide copolymer and the styrene diene copolymer is less than 1 part by mass.

Used ABS resin 100 parts by weight Polyether block amide copolymer 0.5 part by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

<< Comparative Example 3 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 2 were produced in the same manner as in Example 2. In Comparative Example 3, the total of the polyetheramide copolymer and the styrene diene copolymer is less than 1 part by mass.

Used ABS resin 100 parts by mass Styrene butadiene block copolymer 0.5 part by mass Hindered phenol-based antioxidant 0.05 part by mass Phosphate-based antioxidant 0.05 part by mass

<< Comparative Example 4 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 4 were produced in the same manner as in Example 1. In Comparative Example 4, the total of the polyetheramide copolymer and the styrene diene copolymer exceeds 5 parts by mass.

Used ABS resin 100 parts by mass Polyether block amide copolymer 10 parts by mass Hindered phenol-based antioxidant 0.05 part by mass Phosphate-based antioxidant 0.05 part by mass

<< Comparative Example 5 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 5 were produced in the same manner as in Example 2. In Comparative Example 5, the total of the polyetheramide copolymer and the styrene diene copolymer exceeds 5 parts by mass.

Used ABS resin 100 parts by mass Styrene butadiene block copolymer 10 parts by mass Hindered phenol-based antioxidant 0.05 part by mass Phosphoric acid-based antioxidant 0.05 part by mass

<< Comparative Example 6 >>
An ethylene acrylic copolymer was prepared. A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 6 were produced in the same manner as in Example 1. Comparative Example 6 is an example in which an ethylene acrylic copolymer was used instead of at least one of the polyetheramide copolymer and the styrene diene copolymer.

Used ABS resin 100 parts by mass Ethylene acrylic copolymer 5 parts by mass Hindered phenol-based antioxidant 0.05 part by mass Phosphate-based antioxidant 0.05 part by mass

<< Comparative Example 7 >>
A styrene acrylic copolymer was prepared. A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 7 were produced in the same manner as in Example 1. In Comparative Example 7, a styrene acrylic copolymer was used in place of at least one of the polyetheramide copolymer and the styrene diene copolymer.

Used ABS resin 100 parts by mass Styrene acrylic copolymer 5 parts by mass Hindered phenol antioxidant 0.05 part by mass Phosphoric acid antioxidant 0.05 part by mass

<< Comparative Example 8 >>
Methacrylic acid butadiene styrene resin was prepared. A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 8 were produced in the same manner as in Example 1. Comparative Example 8 is an example in which a methacrylic acid butadiene styrene copolymer was used in place of at least one of the polyetheramide copolymer and the styrene diene copolymer.

Used ABS resin 100 parts by weight Methacrylic acid butadiene styrene copolymer 5 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphoric acid-based antioxidant 0.05 part by weight

<< Comparative Example 9 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, in the same manner as in Comparative Example 2, a recycled thermoplastic resin composition and a test piece according to Comparative Example 9 were produced.

Used ABS resin 50 parts by weight Unused ABS resin 50 parts by weight Polyether block amide copolymer 0.5 part by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

<< Comparative Example 10 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, a recycled thermoplastic resin composition and a test piece according to Comparative Example 10 were produced in the same manner as in Comparative Example 5.

Used ABS resin 25 parts by weight Unused ABS resin 75 parts by weight Styrene butadiene block copolymer 10 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

<< Comparative Example 11 >>
A mixture was prepared by mixing the materials in the following formulation. Except for this, in the same manner as in Comparative Example 8, a recycled thermoplastic resin composition and a test piece according to Comparative Example 11 were produced.

Used ABS resin 10 parts by weight Unused ABS resin 90 parts by weight Butadiene styrene styrene copolymer 5 parts by weight Hindered phenol-based antioxidant 0.05 part by weight Phosphate-based antioxidant 0.05 part by weight

<Evaluation>
Each recycled thermoplastic resin composition obtained above was evaluated as follows.

(Gas generation rate)
Gas chromatography mass spectrometry (GC / MS) was performed on 10 mg of the pellets of the regenerated thermoplastic resin composition. The measurement conditions are as follows. However, the following columns are only examples, and it is considered that equivalent products can be used.

Column: “HP-5” manufactured by Agilent Technologies
Heating temperature: 200-250 ° C
Measurement time: 30 minutes

  Since there are many gas species to be detected, the amount of gas generated in each example was compared using stearic acid and palmitic acid with the largest amounts of gas generated as indices. The gas generation amount (relative value) of each example was calculated with the gas generation amount of Comparative Example 1 as 100%. In this example, an example in which the gas generation amount was 50% or less was determined to be acceptable, and an example in which the gas generation amount exceeded 50% was determined to be unacceptable.

(Glossiness)
The appearance design of the molded product was evaluated based on the glossiness. The glossiness was measured on a flat specimen. The glossiness was measured according to “JIS Z 8741: Specular Glossiness—Measurement Method”. The measurement range was φ8 mm. Using a goniophotometer, the glossiness was measured at an incident angle of 60 ° and a light receiving angle of 60 °. In this example, an example having a glossiness of 75% or more was determined to be acceptable, and an example having a glossiness of less than 75% was determined to be unacceptable.

(Charpy impact strength)
The mechanical properties of the molded product were evaluated by Charpy impact strength. A Charpy impact test in accordance with “JIS K 7111” was performed using the multipurpose test piece A type, and the Charpy impact strength was measured. Taking the Charpy impact strength of Comparative Example 1 as 100%, the Charpy impact strength (relative value) of each example was calculated. In this example, an example in which the Charpy impact strength was 75% or more was determined to be acceptable, and an example in which the Charpy impact strength was less than 75% was determined to be unacceptable.

(Comprehensive judgment)
The example in which all the above three evaluation items are acceptable was determined to be a pass (Pass) as a comprehensive determination. An example in which even one of the three evaluation items has failed was set to fail (Fail) as a comprehensive judgment.

<Results and discussion>
The blending and evaluation results of each recycled thermoplastic resin composition obtained above are shown in Tables 1 to 3 below.

  As can be seen from Tables 1 to 3, the recycled thermoplastic resin composition according to the example containing at least one of a polyether amide copolymer and a styrene diene copolymer in a total of 1 to 5 parts by mass is as follows. Compared to a comparative example that does not satisfy the conditions, the amount of gas generation is small, the appearance design is good, and the mechanical properties are also excellent.

  From the results of Examples 1 and 2 and Comparative Examples 6, 7 and 8, the polyetheramide copolymer and the styrene diene copolymer have a remarkable gas generation inhibiting effect as compared with the ethylene acrylic copolymer and the like. It turns out that it has. The polyether amide copolymer and the styrene diene copolymer are considered to have a high adsorbing ability with respect to the spear component and are incompatible with the ABS resin as the main material.

  From the results of Examples 1 to 4 and Comparative Examples 1 to 5, it can be seen that when the total of the polyetheramide copolymer and the styrene diene copolymer is less than 1 part by mass, the gas generation suppressing effect is not sufficient. On the other hand, if the total exceeds 5 parts by mass, the reduction in mechanical properties is large. Therefore, it is considered that the total of at least one of the polyetheramide copolymer and the styrene diene copolymer needs to be 1 part by mass or more and 5 parts by mass or less.

  From the results of Examples 1, 9, 10 and 14, even when the total amount of antioxidants is increased to 1 part by mass, no deterioration in mechanical properties is observed. Therefore, the total amount of antioxidants is preferably 0.05 parts by mass or more and 1 part by mass or less.

  The embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiments and examples but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

Claims (5)

100 parts by weight of ABS resin,
A total of at least one of a polyetheramide copolymer and a styrene diene copolymer of 1 to 5 parts by mass;
Including
The said ABS resin is a reproduction | regeneration thermoplastic resin composition containing 20 mass% or more and 100 mass% or less of used ABS resin. The polyether amide copolymer is a polyether block amide copolymer,
The regenerated thermoplastic resin composition according to claim 1, wherein the styrene diene copolymer is a styrene butadiene block copolymer.   The regenerated thermoplastic according to claim 1 or 2, further comprising a total of 0.05 parts by mass or more and 1 part by mass or less of a phosphorus-based antioxidant or a sulfur-based antioxidant and a hindered phenol-based antioxidant. Resin composition. Preparing a used ABS resin;
100 parts by mass of ABS resin containing 20% by mass or more and 100% by mass or less of the used ABS resin, and a total of 1 part by mass or more and 5 parts by mass or less of at least one of a polyetheramide copolymer and a styrene diene copolymer. And a step of mixing
A method for producing a recycled thermoplastic resin composition. The step of preparing includes
The used ABS resin having a lightness of the surface color of more than 75% is selected according to the surface color of the used ABS resin, and the used ABS resin is rubbed against each other. The method for producing a recycled thermoplastic resin composition according to claim 4, comprising at least one of reducing dark colored foreign matters in the ABS resin.

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