Parts for home appliances containing recycled acrylonitrile butadiene styrene resin and manufacturing method thereof

Abstract

Provided are parts for home appliances, containing a recycled acrylonitrile-butadiene-styrene (ABS) resin, according to the idea of the present disclosure, wherein the recycled ABS resin contains a styrene-acrylonitrile (SAN) resin, in which recycled polystyrene is dispersed, and a butadiene-based rubber.

Description

Parts for home appliances containing recycled ABS resin and manufacturing method thereof

[0001] The present invention relates to a component for home appliances comprising recycled ABS (acrylonitrile-butadiene-styrene) resin and a method for manufacturing the same.

[0002] ABS (acrylonitrile-butadiene-styrene) resin is a plastic with higher impact resistance than general plastics, and is easy to implement in various colors and has a beautiful appearance, so it is used as a material for a wide range of products including home appliances, office equipment, automobile interior and exterior materials, and toys. In particular, in the case of interior and exterior materials of electrical and electronic products that are subjected to repeated stress, it must withstand a certain period of time without breaking or shattering, so excellent impact resistance and fatigue life are required.

[0003] As the use of ABS resin increases, the need for recycling waste ABS resin also increases.

[0004] Recycling methods include mechanical and chemical recycling. Mechanical recycling involves melting collected waste plastic, forming pellets, and mixing them with virgin materials at a specific ratio to produce resin products. While mechanical recycling is the most cost-effective of the commercially available recycling methods, the incorporation of recycled materials in the final molding stage carries the risk of deteriorating physical properties and poor appearance due to foreign matter. Furthermore, the range of available recycled materials is limited.

[0005] Chemical recycling also involves extracting specific polymers from waste plastic using chemical means, recovering them as pure single molecules, and repolymerizing them. Chemical recycling recycles the material back to its monomeric state, before the polymerization stage, which determines its physical properties, and synthesizes it anew. This requires a process such as pyrolysis to break down the polymer into its single molecule state. This requires high energy consumption, with process temperatures exceeding 500°C, which complicates the process and increases material costs.

[0006] Therefore, the need for manufacturing recycled ABS resin that can achieve the same level of physical properties and appearance quality as virgin ABS resin is emerging.

[0007] One aspect of the present disclosure provides a component for a home appliance including a recycled ABS resin capable of improving the compatibility of recycled polystyrene derived from waste plastic to realize physical properties and appearance quality equivalent to those of virgin ABS resin, and a method for manufacturing the same.

[0008] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] In a component for a home appliance including a recycled ABS (acrylonitrile-butadiene-styrene) resin according to one embodiment of the present disclosure, the recycled ABS resin includes a SAN (styrene-acrylonitrile) resin in which recycled polystyrene is dispersed, and a butadiene-based rubber.

[0010] In addition, the above-mentioned recycled ABS resin comprises 85 to 90 wt% of SAN resin in which recycled polystyrene is dispersed and 10 to 15 wt% of butadiene rubber, and the above-mentioned SAN resin may comprise 5 to 15 wt% of recycled polystyrene, 45 to 65 wt% of virgin styrene monomer, and 20 to 28 wt% of virgin acrylonitrile monomer.

[0011] In addition, the above-mentioned recycled polystyrene may be derived from one or more polystyrene-based waste plastics selected from among GPPS (General purpose polystyrene), EPS (Expandel polystyrene), XPS (Extruded polystyrene), SAN (styrene-acrylonitrile), ABS (acrylonitrile-butadiene-styrene), SBS (Styrene-Butadiene-Styrene), and HIPS (High impact polystyrene).

[0012] Additionally, the SAN resin in which the above-mentioned recycled polystyrene is dispersed may have a weight average molecular weight of 140,000 to 180,000 g / mol.

[0013] In addition, the resin may further include one or more additives selected from among UV stabilizers, antioxidants, neutralizers, coupling agents, antistatic agents, dispersants, flame retardants, heat-resistant stabilizers, long-term heat-resistant stabilizers, and antibacterial agents, in an amount of 0.5 to 3 parts by weight per 100 parts by weight of the recycled ABS resin.

[0014] In addition, the above-mentioned recycled ABS resin may have a specific gravity of 1.00 to 1.10 and a weight average molecular weight (Mw) of 100,000 g / mol or more.

[0015] Additionally, the above-mentioned recycled ABS resin may have an impact strength of 200 J / m or more.

[0016] Additionally, the above-mentioned recycled ABS resin may have a tensile strength of 40 MPa or more.

[0017] Additionally, the above-mentioned recycled ABS resin may have a flexural modulus of 2,000 MPa or more.

[0018] Additionally, the above home appliance component may include any one selected from among a refrigerator shelf, a refrigerator storage container, a door basket, and a door guard.

[0019] A method for manufacturing a component for a home appliance according to one embodiment of the present disclosure includes dissolving and refining polystyrene waste plastic in a solvent to obtain regenerated polystyrene, polymerizing a styrene monomer and an acrylonitrile monomer, mixing and dispersing the regenerated polystyrene during the polymerization reaction to manufacture an SNA resin in which the regenerated polystyrene is dispersed, and compounding a butadiene rubber and the SAN resin in which the regenerated polystyrene is dispersed to manufacture a regenerated ABS resin.

[0020] Additionally, the solvent may include at least one solvent selected from among ethylbenzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldehyde, nitrobenzene, and N,N-dimethylformamide.

[0021] In addition, the above-mentioned recycled polystyrene can be obtained by dissolving 20 to 40 parts by weight of polystyrene waste plastic in 60 to 80 parts by weight of a solvent and purifying it.

[0022] Additionally, the above-mentioned recycled polystyrene can be added in an amount of 5 to 15 parts by weight per 100 parts by weight of SAN resin in which recycled polystyrene is dispersed.

[0023] In addition, the SAN resin in which the above-mentioned regenerated polystyrene is dispersed may include a polymerization reaction at a temperature of 45 to 90°C for 3 to 8 hours.

[0024] In addition, the SAN resin in which the regenerated polystyrene is dispersed may further include a washing and drying step after the polymerization reaction.

[0025] According to the idea of ​​the present disclosure, a component for a home appliance including a recycled ABS resin capable of improving the compatibility of recycled polystyrene derived from waste plastic and realizing physical properties and appearance quality equivalent to those of virgin ABS resin, and a method for manufacturing the same can be provided.

[0026] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0027] FIG. 1 is a drawing showing a process diagram for a method of manufacturing a component for a home appliance according to one embodiment.

[0028] FIG. 2 is a drawing showing a refrigerator component to which a component for a home appliance according to an embodiment of the present invention is applied.

[0029] FIG. 3 is a drawing illustrating a refrigerator to which a component for a home appliance according to one embodiment is applied.

[0030] FIG. 4 is a diagram showing the results of measuring the dispersibility and compatibility of recycled polystyrene according to one embodiment.

[0031] Fig. 5 is a drawing showing whether the surface of an ABS resin is peeled off according to one embodiment.

[0032] Figure 6 is a drawing showing a cross-section of a conventional ABS resin manufactured by adding recycled polystyrene during extrusion of SAN resin and butadiene rubber.

[0033] FIG. 7 is a diagram showing the results of fatigue durability life measurement according to the content of recycled polystyrene according to one embodiment of the present disclosure.

[0034] FIG. 8 is a diagram showing the results of fatigue durability life measurement according to the content of recycled polystyrene according to one embodiment of the present disclosure.

[0035] FIG. 9 is a diagram showing the results of fatigue durability life measurement according to an increase in the weight average molecular weight and AN content of SAN resin according to one embodiment of the present disclosure.

[0036] FIG. 10 is a diagram showing the results of fatigue durability life measurement according to an increase in the weight average molecular weight and AN content of SAN resin according to one embodiment of the present disclosure.

[0037] FIG. 11 is a diagram showing the results of fatigue durability life measurement according to an increase in the weight average molecular weight of a SAN resin according to one embodiment of the present disclosure.

[0038] FIG. 12 is a diagram showing the results of fatigue durability life measurement according to an increase in the weight average molecular weight of a SAN resin according to one embodiment of the present disclosure.

[0039] FIG. 13 is a diagram showing the results of fatigue endurance life measurement according to an increase in AN content according to one embodiment of the present disclosure.

[0040] FIG. 14 is a diagram showing the results of fatigue endurance life measurement according to an increase in AN content according to one embodiment of the present disclosure.

[0041] Preferred embodiments of the present invention are described below. However, the embodiments of the present invention may be modified in various ways, and the technical concept of the present invention is not limited to the embodiments described below. Furthermore, the embodiments of the present invention are provided to more fully explain the present invention to those of ordinary skill in the art.

[0042] The terminology used in this application is solely for the purpose of describing specific examples. Therefore, for example, singular expressions include plural expressions unless the context clearly dictates otherwise. Additionally, it should be noted that terms such as "comprise" or "have" used in this application are used to clearly indicate the presence of features, steps, functions, components, or combinations thereof described in the specification, and are not used to preliminarily exclude the presence of other features, steps, functions, components, or combinations thereof.

[0043] Meanwhile, unless otherwise defined, all terms used herein should be considered to have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Therefore, unless explicitly defined herein, specific terms should not be interpreted in an overly idealistic or formal sense. For example, singular expressions herein include plural expressions unless the context clearly indicates otherwise.

[0044] In addition, the terms "about", "substantially", etc. in this specification are used in the sense of or close to the numerical value when manufacturing and material tolerances inherent to the meanings mentioned are presented, and are used to prevent unscrupulous infringers from unfairly using the disclosure contents in which exact or absolute numerical values ​​are mentioned to aid in the understanding of the present invention.

[0045] The following describes in detail a component for home appliances containing recycled ABS resin and a method for manufacturing the same.

[0046] General-purpose polystyrene (GPPS) is a representative thermoplastic resin. Its lightness, excellent insulation, and non-toxicity make it the most commonly used polystyrene (PS)-based synthetic resin. In everyday life, it's primarily used in food packaging and disposable items. Among home appliances, it's found in transparent refrigerator covers and guard components.

[0047] When a product to which GPPS is applied is disposed of, there is a need to recycle the waste GPPS contained in the product. Accordingly, the present disclosure provides a method for manufacturing a recycled ABS resin by recycling waste plastics such as waste GPPS from discarded home appliances, and providing injection-molded home appliance parts using the recycled ABS resin.

[0048] That is, in the present disclosure, when recycled polystyrene derived from waste plastic is introduced into a SAN (styrene-acrylonitrile) polymerization step in which the properties of the material are determined, the recycled polystyrene is introduced into a solution containing a virgin styrene monomer and a virgin acrylonitrile monomer for SAN polymerization, thereby maximizing the dispersion of the recycled polystyrene through the SAN polymerization process, thereby improving compatibility with the final recycled ABS resin, preventing delamination during injection molding, and exhibiting properties and appearance quality equivalent to those of virgin ABS resin.

[0049] The home appliance parts described in the present disclosure refer to plastic parts applied to home appliances such as refrigerators, washing machines, air conditioners, and vacuum cleaners, and include, for example, refrigerator shelves, food storage containers, door baskets, and door guards.

[0050] In a component for a home appliance including a recycled ABS resin according to one embodiment of the present disclosure, the recycled ABS resin includes a SAN resin in which recycled polystyrene is dispersed, and a butadiene-based rubber.

[0051] The above SAN resin includes recycled polystyrene, a virgin styrene monomer, and a virgin acrylonitrile monomer, and the recycled polystyrene is dispersed in the SAN resin in a polymer state. In other words, the SAN resin in which the recycled polystyrene is dispersed means a state in which recycled polystyrene is dispersed in a SAN resin that is a polymer of a virgin styrene monomer and a virgin acrylonitrile monomer.

[0052] The above-mentioned recycled polystyrene may be polystyrene derived from polystyrene waste plastic, and may be derived from one or more polystyrene waste plastics selected from, for example, GPPS (General purpose polystyrene), EPS (Expandel polystylene), XPS (Extruded polystyrene), SAN (styrene-acrylonitrile), ABS (acrylonitrile-butadiene-styrene), SBS (Styrene-Butadiene-Styrene), and HIPS (High impact polystylene).

[0053] Depending on the content of the recycled polystyrene, the recycled ABS resin may become embrittled or its durability may be reduced, so it is important to include an appropriate amount of recycled polystyrene.

[0054] Considering these points, the above-mentioned recycled polystyrene may be included in an amount of 5 to 15 parts by weight per 100 parts by weight of the SAN resin in which the recycled polystyrene is dispersed. If the content of the recycled polystyrene is too low, it is difficult to achieve the purpose of the present disclosure of utilizing the recycled polystyrene, and if the content of the recycled polystyrene is too high, an excessive amount of recycled polystyrene is dispersed in the SAN solution, which may cause problems during SAN polymerization.

[0055] The above-mentioned new styrene monomer is not particularly limited, but may include, for example, one or more monomers selected from styrene, α-methylstyrene, β-methylstyrene, p-methylstyrene, p-tert-butylstyrene, o-bromostyrene, o-chlorostyrene, m-bromostyrene, m-chlorostyrene, p-bromostyrene, and p-chlorostyrene.

[0056] The above-mentioned new styrene monomer may be included in an amount of 45 to 65 parts by weight per 100 parts by weight of SAN resin in which recycled polystyrene is dispersed, and when included within the above range, an appropriate polymerization rate can be maintained and the physical properties of the SAN resin can be excellent.

[0057] The above-mentioned new acrylonitrile monomer is not particularly limited, but may include, for example, one or more monomers selected from acrylonitrile, methacrylonitrile, and ethacrylonitrile.

[0058] The above-mentioned new acrylonitrile monomer may be included in an amount of 20 to 28 parts by weight per 100 parts by weight of SAN resin in which recycled polystyrene is dispersed. When included within the above range, the molecular weight size of the SAN resin produced does not become excessive, and the molecular weight distribution appears at an appropriate level, so that the workability and physical properties of the ABS resin produced by including the monomer may be excellent.

[0059] Increasing the weight average molecular weight of SAN resin within an appropriate range can provide resistance to crack initiation, thereby improving fatigue life.

[0060] Considering these points, the weight average molecular weight of the SAN resin may be 140,000 to 180,000 g / mol. If the weight average molecular weight of the SAN resin is too low, it tends to be brittle fractured, making it difficult to guarantee quality in terms of long-term reliability. If it is too high, problems may occur during injection molding of recycled ABS resin.

[0061] The above-mentioned recycled ABS resin may contain 85 to 90 wt% of SAN resin in which the recycled polystyrene described above is dispersed and 10 to 15 wt% of butadiene-based rubber.

[0062] If the content of the SAN resin in which the regenerated polystyrene is dispersed is too low or the content of the butadiene-based rubber is too high, the tensile strength may be reduced, and if the content of the SAN resin in which the regenerated polystyrene is dispersed is too high or the content of the butadiene-based rubber is too low, the impact strength may be deteriorated.

[0063] The above butadiene-based rubber is not particularly limited, and examples thereof include 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, etc.

[0064] The average particle diameter of the above butadiene-based rubber may be 1500 to 5000 Å.

[0065] The above-mentioned recycled ABS resin may be a compound of butadiene rubber and SAN resin in which recycled polystyrene is dispersed. The above-mentioned compounding refers to a process of mixing butadiene rubber and SAN resin in which recycled polystyrene is dispersed, extrusion molding, and then pelletizing. The above-mentioned recycled ABS resin may have a core-shell shape, wherein the core portion at the center is made of butadiene rubber, and the shell portion surrounding the core surface is made of SAN resin.

[0066] In addition, the ABS resin may further include one or more additives selected from among UV stabilizers, antioxidants, neutralizers, coupling agents, antistatic agents, dispersants, flame retardants, heat-resistant stabilizers, long-term heat-resistant stabilizers, and antibacterial agents. The additives may be included in an amount of 0.5 to 3 parts by weight per 100 parts by weight of the recycled ABS resin.

[0067] For example, the antioxidant may include a phenol-based antioxidant, a phosphite-based antioxidant, a thiodipropionate synergist, etc. The neutralizing agent may include calcium stearate, zinc oxide, etc. The coupling agent may include a polymer having a reactive functional group, such as maleic acid or an elastomeric compatibilizer. The antistatic agent may include a cationic quaternary ammonium salt, glycerin monostearate, etc. The dispersing agent may include tricalcium phosphate, etc. The flame retardant may include a brominated flame retardant, such as hexabromocyclododecane, tetrabromocyclooctane, tetrabromovinylcyclohexane, 2,2'(4-allyloxy-3,5-dibromophenyl)propane, or tribromophenyl allyl ether, a chlorinated flame retardant, or a phosphorus flame retardant. As the above flame retardant additive, dicumyl peroxide and the like can be used. As the above heat-resistant stabilizer, tetrakis(methylene(3,5-di-tert-butyl-4-hydroxycinnamate))methane, 3,3'-bis(3,5-di-tert-butyl-4-hydroxylphenyl)-N,N'-hexamethylenedipropionamide and the like can be used. As the above long-term heat-resistant stabilizer, a phenol-based antioxidant, a phosphite-based antioxidant and the like can be used.

[0068] The above-mentioned recycled ABS resin may have a specific gravity of 1.00 to 1.10 and a weight average molecular weight (Mw) of 100,000 g / mol or more.

[0069] If the above weight average molecular weight is low, it exists in the form of a monomer rather than a polymer and is easily eluted, and if it is too high, the strength and chemical resistance are reduced and molding defects may occur during injection molding.

[0070] In addition, the above-mentioned recycled ABS resin may have an impact strength of 200 J / m or more, a tensile strength of 40 MPa or more, and a flexural modulus of 2,000 MPa or more.

[0071] If the above impact strength is too low, deformation or cracks may occur during the assembly process, and if it is too high, fluidity may be reduced, resulting in a drop in productivity.

[0072] If the above tensile strength is too low, deformation or cracks may occur during the assembly process, similar to the impact strength, and if it is too high, fluidity may be reduced, resulting in a drop in productivity.

[0073] If the above flexural modulus is too low, deformation due to load may occur, and if it is too high, cracks may occur during the assembly process.

[0074] Next, a method for manufacturing a component for a home appliance according to one embodiment of the present disclosure will be described with reference to the drawings.

[0075] Figure 1 is a drawing showing a process diagram for a method of manufacturing a component for a home appliance according to one embodiment.

[0076] Referring to FIG. 1, a method for manufacturing a component for a home appliance according to one embodiment includes dissolving and refining polystyrene waste plastic in a solvent to obtain regenerated polystyrene, polymerizing a styrene monomer and an acrylonitrile monomer, mixing and dispersing the regenerated polystyrene during the polymerization reaction to manufacture an SNA resin in which the regenerated polystyrene is dispersed, and compounding a butadiene rubber and a SAN resin in which the regenerated polystyrene is dispersed to manufacture a regenerated ABS resin.

[0077] The above-mentioned recycled polystyrene may be polystyrene derived from the polystyrene-based waste plastic described above. The above-mentioned recycled polystyrene may be extracted from the waste plastic using a conventional method. In the present disclosure, the recycled polystyrene is extracted using a solvent extraction method, but the extraction method is not limited thereto.

[0078] For example, a method of extracting regenerated polystyrene by a solvent extraction method can be performed by dissolving polystyrene waste plastic in a solvent and purifying it. At this time, 20 to 40 parts by weight of polystyrene waste plastic can be dissolved in 60 to 80 parts by weight of solvent so as to sufficiently dissolve the polystyrene waste plastic. When the contents of the solvent and the polystyrene waste plastic are within the above ranges, the polystyrene waste plastic can be sufficiently dissolved, thereby increasing the extraction efficiency of regenerated polystyrene from the polystyrene waste plastic.

[0079] The solvent may be an organic solvent capable of dissolving polystyrene waste plastic, and for example, at least one solvent selected from among ethylbenzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldehyde, nitrobenzene, and N,N-dimethylformamide may be used.

[0080] The above extraction can be performed at a temperature of 50°C to 300°C and a pressure of 1 to 20 MPa. Furthermore, the polystyrene precipitated in the solvent after the extraction can be further washed and dried to obtain regenerated polystyrene. The washing and drying can be performed using conventional methods, and can be performed more than once, if necessary.

[0081] Recycled polystyrene is introduced in the SAN resin polymerization step where the properties of the material are determined. The recycled polystyrene is introduced into a mixture of a new styrene monomer and a new acrylonitrile monomer for SAN resin polymerization, and a polymerization reaction occurs while the recycled polystyrene is dissolved. During the polymerization, the recycled polystyrene does not participate in the SAN polymerization, but is dissolved and dispersed in the new SAN solution in a polymer state.

[0082] In addition, the above-mentioned new styrene monomer, new acrylonitrile monomer, and recycled polystyrene can be prepared in the form of a solution dissolved in a solvent. At this time, the solvent that can be used is not limited in type as long as it can dissolve the above-mentioned components, and for example, water, ethanol, ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butanediol, propylene glycol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl ethyl ketone, acetone, methyl amyl ketone, cyclohexanone, cyclopentanone, diethylene glycol monomethyl ether, diethylene glycol ethyl ether, toluene, xylene, butyrolactone, carbitol, methyl cellosolve acetate, N,N-dimethylformamide, N,N-dimethylacetamide, etc. can be used.

[0083] The polymerization of the above SAN resin can be performed according to a conventional method, and for example, the polymerization reaction can be performed at a temperature of 45 to 90°C for 3 to 8 hours. Specifically, the polymerization can be achieved by methods such as emulsion polymerization, suspension polymerization, and bulk polymerization, and an appropriate polymerization method can be selected depending on the final use.

[0084] The SAN resin in which the recycled polystyrene obtained through the above polymerization is dispersed is a state in which the recycled polystyrene in a polymer state is dissolved and dispersed in a new SAN resin solution. That is, during the polymerization, the new styrene monomer and the new acrylonitrile monomer participate in the polymerization to form the SAN resin, and the recycled polystyrene does not participate in the polymerization and exists dispersed in the new SAN solution in a polymer state.

[0085] In addition, the SAN resin in which the regenerated polystyrene is dispersed can be further subjected to washing and drying steps to obtain a final SAN resin in which the regenerated polystyrene is dispersed. In particular, the drying process can improve the transparency and increase the heat resistance of the final SAN resin in which the regenerated polystyrene is dispersed by volatilizing unreacted monomers and solvents remaining after the polymerization reaction.

[0086] Next, the SAN resin in which the regenerated polystyrene is dispersed is compounded with butadiene rubber to produce a regenerated ABS resin. That is, the SAN resin in which the regenerated polystyrene is dispersed and the butadiene rubber can be mixed and extruded to produce regenerated ABS resin pellets.

[0087] The method for mixing the SAN resin and butadiene-based rubber in which the above-mentioned recycled polystyrene is dispersed is not particularly limited, but a mechanical shearing method for mixing each component using a screw-type extruder may be used.

[0088] The above extrusion can be performed at 180°C to 230°C. If the temperature is too low during the extrusion, the manufacturing process may be delayed and productivity may be reduced, and if it is too high, the mixed components may decompose.

[0089] The above-mentioned recycled ABS resin has excellent dispersibility and compatibility by including the above-mentioned recycled polystyrene in a form dispersed in a SAN resin, and thus can realize excellent appearance quality without surface peeling, and can have mechanical properties equivalent to those of new ABS resin.

[0090] That is, in the present disclosure, by introducing recycled polystyrene derived from waste plastic in the SAN polymerization step where the properties of the material are determined, the dispersibility is maximized through a polymerization process in which a new styrene monomer and a new acrylonitrile monomer are polymerized to manufacture a SAN resin, thereby improving the compatibility of the recycled polystyrene, and accordingly, a recycled ABS resin having mechanical properties and appearance quality equivalent to those of the new ABS resin can be obtained without the problem of the outer layer and the inside being peeled off and torn during injection molding.

[0091] Next, a refrigerator to which a component for a home appliance according to one embodiment of the present disclosure is applied will be described with reference to drawings.

[0092] FIG. 2 is a drawing illustrating a refrigerator component to which a home appliance component according to an embodiment of the present invention is applied. FIG. 3 is a drawing illustrating a refrigerator to which a home appliance component according to an embodiment of the present invention is applied.

[0093] Referring to FIGS. 2 and 3, a refrigerator (1) according to one embodiment includes a main body (10), a storage compartment (21, 22, 23) formed inside the main body (10), a door (31, 32, 33, 34) for opening and closing the storage compartment (21, 22, 23), and a cold air supply device (not shown) for supplying cold air to the storage compartment (21, 22, 23), and a shelf (26) for placing food and a storage container (27) for storing food are provided inside the storage compartment (21, 22, 23), and a door basket (39) and a door guard (40) for storing food are provided in the door (31, 32, 33, 34), and the shelf (26), the storage container (27), the door basket (39) and the door guard (40) are for home appliances including the recycled ABS resin of the present disclosure. It may include parts. That is, the recycled ABS resin including the recycled polystyrene derived from the above-described waste plastic can be applied to the shelf (26), storage container (27), door basket (39) and door guard (40) of the refrigerator.

[0094] A top cover (24) may be attached to the upper surface of the main body (10). The top cover (24) may be provided to cover hinges and various electrical components arranged on the upper surface of the main body (10). A control panel (25) may be provided on the front of the top cover (24) to display various status and operation information of the refrigerator (1) or input various commands for the operation of the refrigerator (1).

[0095] The storage rooms (21, 22, 23) can be divided into a plurality of sections by horizontal bulkheads (15) and vertical bulkheads (16). The storage rooms (21, 22, 23) can be divided into an upper storage room (21) and a lower storage room (22, 23) by the horizontal bulkhead (15), and the lower storage rooms (22, 23) can be divided into a lower left storage room (22) and a lower right storage room (23) by the vertical bulkhead (16).

[0096] The upper storage compartment (21) can be used as a refrigerator, and the lower storage compartments (22, 23) can be used as a freezer. However, the division and use of the storage compartments (21, 22, 23) as described above are only an example and are not limited thereto.

[0097] In addition, unlike the present embodiment, the refrigerator may be of the SBS (Side By Side) type in which the storage compartment is divided into left and right sides by vertical partitions, the FDR (French Door Refrigerator) type in which the storage compartment is divided into an upper refrigerator compartment and a lower refrigerator compartment by horizontal partitions, or a single-door type having one storage compartment and one door.

[0098] Inside the storage room (21, 22, 23), a shelf (26) for placing food and a storage container (27) for storing food can be provided.

[0099] The cold air supply device can generate cold air by using a cooling cycle of compressing, condensing, expanding, and evaporating a refrigerant, and supply the generated cold air to a storage room (21, 22, 23).

[0100] The upper storage compartment (21) can be opened and closed by a pair of doors (31, 32). The doors (31, 32) can be rotatably coupled to the main body (10). A filler (43) can be provided on one of the doors (31, 32) to prevent cold air from leaking out of the storage compartment (21) between the doors (31, 32) when the pair of doors (31, 32) is closed. The filler (43) can be guided by a filler guide (13) provided on the main body (10).

[0101] The lower left storage compartment (22) can be opened and closed by a door (33), and the door (33) can be rotatably coupled to the main body (10). The lower right storage compartment (23) can be opened and closed by a door (34), and the door (34) can be rotatably coupled to the main body (10).

[0102] The door (31, 32, 33, 34) may include a door basket (39) having a door storage space for storing food and a door guard (40). A gasket (101) that is in close contact with the front of the main body (10) to seal the storage compartment (21, 22, 23) may be provided on the back surface of the door (31, 32, 33, 34).

[0103] At least one of the doors (31, 32, 33, 34) may be configured as a double door having an inner door (100) and an outer door (110). For example, the upper left door may include an inner door (100) and an outer door (110).

[0104] The inner door (110) can be rotatably connected to the main body (10) via a hinge. The inner door (100) can have an inner space. The inner space can be formed in the central portion of the inner door (100) excluding the edge portion. The inner space can be formed to extend between the front and back surfaces of the inner door (100). Therefore, when the inner door (100) is closed, the inner space of the door can be connected to the storage compartment (21).

[0105] A door basket (39) and a door guard (40) can be installed in the inner space of the door.

[0106] The outer door (110) may be configured to open and close the inner space of the inner door (100). A gasket may be provided on the back surface of the outer door (110) to seal the inner space of the door. The gasket may be attached to the front surface of the inner door (100) around the inner space of the door.

[0107] Meanwhile, the home appliance parts including the recycled ABS resin of the present disclosure can be applied to home appliance parts such as washing machines, air conditioners, and vacuum cleaners in addition to refrigerators.

[0108] Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are intended only to illustrate the present invention and the scope of the present invention is not limited to these examples.

[0109] Example

[0110] 20-40 wt% of polystyrene waste plastic GPPS was dissolved in 60-80 wt% of ethylbenzene and purified to extract recycled polystyrene.

[0111] The extracted recycled polystyrene (5-15 wt%) was added to a stirred tank reactor containing 45-65 wt% of virgin styrene monomer and 20-28 wt% of virgin acrylonitrile monomer, and polymerized at 45-90°C for 3-8 hours to produce a SAN resin solution in which the recycled polystyrene was dispersed. The SAN resin solution in which the recycled polystyrene was dispersed was washed and vacuum-dried. The molecular weight of the vacuum-dried SAN resin in which the recycled polystyrene was dispersed was 100,000-180,000 g / mol.

[0112] 85 to 90 wt% of the above-described dried regenerated polystyrene dispersed SAN resin and 10 to 15 wt% of butadiene rubber were mixed and extruded at 180 to 230°C to produce regenerated ABS resin pellets.

[0113] Comparative Example 1

[0114] New ABS resin manufactured without using recycled polystyrene was used.

[0115] Comparative Example 2

[0116] Conventional ABS resin was used, which was manufactured by adding recycled polystyrene during extrusion of SAN resin and butadiene rubber.

[0117] Table 1 below shows the content of recycled polystyrene, the content of virgin acrylonitrile, and the molecular weight of the SAN resin. Table 2 also shows the tensile strength, impact strength, flexural modulus, and flow index. Furthermore, the results of measurements of the dispersibility and compatibility of recycled polystyrene are shown in Figure 4, and the presence or absence of surface peeling is shown in Figures 5 and 6.

[0118] In FIGS. 4 and 5, (a) shows the results of an example, (b) shows the results of comparative example 1, and (c) shows the results of comparative example 2.

[0119] Tensile strength was measured at room temperature at a tensile speed of 50 mm / min using a Universal Testing Machine (UTM) (Model: Instron 5969, Capacity: 50 kN) according to ASTM D638 standard.

[0120] Impact strength was measured at room temperature using a 6.4 mm thick specimen according to ASTM D256 standard.

[0121] Flexural modulus was measured at room temperature at a test speed of 5 mm / min according to ASTM D790 standard.

[0122] Melt Index (MI) was measured at 230℃ and 2.16㎏ load according to ASTM D1238 standard.

[0123] To visually confirm dispersibility, compatibility, and surface peeling, images were taken using an optical microscope and a transmission electron microscope as follows.

[0124] Transmission Electron Microscopy (TEM): The microstructure of a thin film specimen less than 0.1 μm thick stained with OsO4 was observed using TEM (Product No.: JEM-F200, Manufacturer: JEOL) to confirm dispersibility and compatibility.

[0125] Optical microscope: The fracture surface of the ASTM D638 tensile strength specimen was photographed at 50x magnification using a digital optical microscope (Product No.: AM3113, Manufacturer: Dino-Lite) to observe the presence of surface peeling.

[0126] Recycled polystyrene (parts by weight) New styrene (parts by weight) New acrylonitrile (parts by weight) SAN molecular weight (g / mol) Example 105624140,000 Comparative example 106624140,000 Comparative example 2105624140,000

[0127] Tensile strength (MPa) Impact strength (J / m) Flexural modulus (MPa) Flow index (g / 10min) Example 44.72451,8633.0 Comparative example 147.22351,9614.0 Comparative example 236.1592,0592.5

[0128] As shown in Table 2 above, in the case of an example in which recycled polystyrene was added to a mixture of styrene monomer and acrylonitrile monomer during SAN polymerization to manufacture a recycled ABS resin, it was confirmed that the tensile strength, impact strength, flexural modulus, and flow index were similar to those of the virgin ABS resin of Comparative Example 1 even though the recycled polystyrene was included. Fig. 4 shows dispersibility and compatibility, and as shown in Fig. 4, the example according to the present disclosure showed a microstructure similar to that of the virgin ABS resin of Comparative Example 1. On the other hand, in the case of the conventional ABS resin of Comparative Example 2 in which recycled polystyrene was added during extrusion of the SAN resin and butadiene rubber, it was confirmed that the SAN resin and the recycled polystyrene were not compatible, and thus the recycled polystyrene domains existed in a phase-separated form from the SAN resin, such as oval spaces.

[0129] Fig. 5 shows the fracture surface of an ASTM D638 tensile strength specimen to determine whether there is surface peeling. As shown in Fig. 5, in the case of the examples and comparative example 1 according to the present disclosure, no surface peeling occurred, but in the case of the conventional ABS resin of comparative example 2, it was confirmed that the surface layer and the interior were peeled off and torn even in the fracture surface of the specimen (Fig. 6).

[0130] Experimental example

[0131] As shown in Table 3 below, recycled ABS resin was manufactured by varying the content of recycled polystyrene, the weight average molecular weight of SAN resin, and the content of virgin acrylonitrile (AN).

[0132] The tensile strength, toughness, elastic modulus, elongation at break, fatigue durability and appearance of the manufactured recycled ABS resin were measured using the following methods, and the results are shown in Table 4 below.

[0133] Tensile properties, including tensile strength, toughness, elongation at break, and elastic modulus, were measured at room temperature at a speed of 50 mm / min using a Universal Testing Machine (UTM) (Model: Instron 5969, Capacity: 50 kN) according to ASTM D638-1 Type 1.

[0134] Fatigue endurance life was measured using the same tester and specimens used in the tensile test, ASTM D638-1 Type I specimens, under sinusoidal cyclic loading in a tension-tension configuration on an MTS 810 tester. The maximum load was set at 80%, 70%, 60%, and 50% of the tensile strength at break, with the ratio of the minimum to maximum load (R-ratio) being 0.1 and the frequency of the load cycle being 2 Hz.

[0135] The appearance was evaluated visually and the presence of foreign substances on the surface and the presence of peeling of the epidermis were confirmed through observation of the judgment surface.

[0136] Classification Recycled polystyrene content (wt%) SAN weight average molecular weight (g / mol) AN content (wt%) Comparative example 10 100,000 24 Comparative example 20 140,000 24 Comparative example 30 140,000 28 Comparative example 40 180,000 20 Example 15 100,000 20 Example 25 140,000 28 Example 35 180,000 24 Example 410 100,000 28 Example 510 140,000 20 Example 610 140,000 24 Example 710 180,000 24 Example 815 100,000 20 Example 915 140,000 24 Example 1015180,00028

[0137] Tensile strength (MPa) Toughness (MJ / ㎥) Elastic modulus (MPa) Elongation at break (mm / mm) Fatigue durability life Appearance Stress amplitude (MPa) (@10 3 Cycles) Stress amplitude (MPa) (@10 6 Cycles) Comparative Example 145.117.91097.80.50915.644.64○Comparative Example 247.219.71147.90.53816.978.52○Comparative Example 346.818.41057.80.50117.119.33○Comparative Example 445.414.61065.80.42116.238.52○Example 146.111.01070.50.31016.038.29○Example 247.619.31152.80.52316.879.38○Example 347.715.91182.70.43117.519.80○Example 444.61.61077.80.05813.905.43○Example 542.95.61063.70.17213.574.98○Example 644.716.11165.20.46616.398.07○Example 746.010.51136.50.29716.918.90○Example 841.81.11112.10.04911.631.68△Example 945.711.61335.90.33315.397.47△Example 1047.010.81163.30.29917.0210.63△

[0138] As in Comparative Example 2, Examples 6 and 9 of Table 4, and Examples 1 and 8, when the content of recycled polystyrene was changed under the same conditions as the weight average molecular weight and AN content of the SAN resin, it was confirmed that the material was embrittled and the toughness and fatigue life were reduced. Fig. 7 shows the experimental results of Comparative Example 2 and Examples 6 and 9 with different contents of recycled polystyrene when the weight average molecular weight of the SAN resin was 140,000 g / mol and the AN content was 24 wt%, and Fig. 8 shows the experimental results of Examples 1 and 8 with different contents of recycled polystyrene when the weight average molecular weight of the SAN resin was 100,000 g / mol and the AN content was 20 wt%. In particular, when the content of recycled polystyrene was as high as 10 wt% and the weight average molecular weight of the SAN resin was as low as 140,000 g / mol or less, a tendency toward brittle fracture was observed. From these results, it was found that when the content of recycled polystyrene was as high as 10 wt% and the weight average molecular weight of the SAN resin was as low as 140,000 g / mol or less, it would be applicable to non-appearance and non-durable parts.

[0139] As shown in Examples 1 to 3 and Examples 8 to 10 of Table 4 above, it was confirmed that the fatigue durability characteristics of the recycled ABS resin were effectively improved as the weight average molecular weight and AN content of the SAN resin increased. Fig. 9 shows the experimental results of Examples 1 to 3 according to the increase in the weight average molecular weight and AN content of the SAN resin in the case of 5 wt% of recycled polystyrene, and Fig. 10 shows the experimental results of Examples 8 to 10 according to the increase in the weight average molecular weight and AN content of the SAN resin in the case of 15 wt% of recycled polystyrene.

[0140] As shown in Comparative Examples 1 and 2 and Examples 3 and 6 in Table 4 above, it was confirmed that the fatigue durability life was improved by imparting resistance to crack initiation as the weight average molecular weight of the SAN resin increased. Fig. 11 shows the experimental results of Comparative Examples 1 and 2 according to the increase in the weight average molecular weight of the SAN resin when the recycled polystyrene content was 0 wt% and the AN content was 24 wt%, and Fig. 12 shows the experimental results of Examples 3 and 6 according to the increase in the weight average molecular weight of the SAN resin when the polystyrene content was 10 wt% and the AN content was 24 wt%.

[0141] In addition, as shown in Examples 5 and 6 and Comparative Examples 2 and 3 in Table 4, it was confirmed that crack propagation resistance was improved and fatigue durability was improved as the AN content increased. Fig. 13 shows the experimental results of Examples 5 and 6 according to the increase in AN content when the recycled polystyrene content was 10 wt% and the weight average molecular weight of the SAN resin was 140,000 g / mol, and Fig. 14 shows the experimental results of Comparative Examples 2 and 3 according to the increase in AN content when the recycled polystyrene content was 0 wt% and the weight average molecular weight of the SAN resin was 140,000 g / mol. In particular, the acrylonitrile (AN) functional group was thought to be effective in reducing fatigue deterioration due to the effects resulting from dipole interaction and hydrogen bonding.

[0142] From the above results, it was found that since the recycled ABS resin may become embrittled or have reduced fatigue durability characteristics as the content of recycled polystyrene increases, it is possible to use the recycled ABS resin of the present disclosure by mixing an appropriate composition while simultaneously considering the cost aspect so that it is suitable for the required properties of the part to which it is applied.

Claims

1. In home appliance parts containing recycled ABS (acrylonitrile-butadiene-styrene) resin, The above recycled ABS resin is, SAN (styrene-acrylonitrile) resin with recycled polystyrene dispersed therein, and Parts for home appliances containing butadiene rubber.

2. In paragraph 1, The above recycled ABS resin is, Contains 85 to 90 wt% of SAN resin dispersed with recycled polystyrene and 10 to 15 wt% of butadiene rubber, The above SAN resin is a component for home appliances containing 5 to 15 parts by weight of recycled polystyrene, 45 to 65 parts by weight of virgin styrene monomer, and 20 to 28 parts by weight of virgin acrylonitrile monomer.

3. In paragraph 1, The above recycled polystyrene is a component for home appliances derived from one or more polystyrene waste plastics selected from among GPPS (General purpose polystyrene), EPS (Expandel polystyrene), XPS (Extruded polystyrene), SAN (styrene-acrylonitrile), ABS (acrylonitrile-butadiene-styrene), SBS (Styrene-Butadiene-Styrene), and HIPS (High impact polystyrene).

4. In paragraph 1, The SAN resin in which the above-mentioned recycled polystyrene is dispersed is a component for home appliances having a weight average molecular weight of 140,000 to 180,000 g / mol.

5. In paragraph 1, The above-mentioned recycled ABS resin is a component for home appliances, which further contains 0.5 to 3 parts by weight of one or more additives selected from among UV stabilizers, antioxidants, neutralizers, coupling agents, antistatic agents, dispersants, flame retardants, heat-resistant stabilizers, long-term heat-resistant stabilizers, and antibacterial agents, based on 100 parts by weight of the recycled ABS resin.

6. In paragraph 1, The above recycled ABS resin is a component for home appliances having a specific gravity of 1.00 to 1.10 and a weight average molecular weight (Mw) of 100,000 g / mol or more.

7. In paragraph 1, The above recycled ABS resin is a component for home appliances with an impact strength of 200 J / m or more.

8. In paragraph 1, The above recycled ABS resin is a component for home appliances with a tensile strength of 40 MPa or more.

9. In paragraph 1, The above recycled ABS resin is a component for home appliances having a flexural modulus of 2,000 MPa or more.

10. In paragraph 1, The above home appliance component is a home appliance component including any one selected from among a refrigerator shelf, a refrigerator storage container, a door basket, and a door guard.

11. Dissolving polystyrene waste plastic in a solvent and refining it to obtain recycled polystyrene, A styrene monomer and an acrylonitrile monomer are polymerized, and the recycled polystyrene is mixed and dispersed during the polymerization reaction to produce an SNA resin in which the recycled polystyrene is dispersed. A method for manufacturing an exterior part of a home appliance comprising a recycled ABS resin, comprising: manufacturing a recycled ABS resin by compounding a butadiene-based rubber and a SAN resin in which the recycled polystyrene is dispersed.

12. In paragraph 11, The above-mentioned recycled polystyrene is a method for manufacturing an exterior component of a home appliance, obtained by dissolving 20 to 40 parts by weight of polystyrene waste plastic in 60 to 80 parts by weight of a solvent and refining the same.

13. In paragraph 11, A method for manufacturing an exterior component of a home appliance, wherein the above-mentioned recycled polystyrene is included in an amount of 5 to 15 parts by weight per 100 parts by weight of SAN resin in which recycled polystyrene is dispersed.

14. In paragraph 11, A method for manufacturing an exterior component of a home appliance, comprising polymerizing a SAN resin in which the above-mentioned recycled polystyrene is dispersed at a temperature of 45 to 90°C for 3 to 8 hours.

15. In paragraph 11, A method for manufacturing an exterior component of a home appliance, wherein the SAN resin in which the above-mentioned recycled polystyrene is dispersed further comprises a step of washing and drying after the above-mentioned polymerization reaction.

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