Gasket for refrigerator door

Abstract

Provided, according to the present invention, may be: an insulation material for a refrigerator, which is used in parts around a gasket and provides enhanced thermal insulation; and a refrigerator including same. The insulation material for a refrigerator according to the present invention includes, by weight%, 75-95 wt% of a thermoplastic resin, 20 wt% or less of a filler, 5 wt% or less of a blowing agent, and 1 wt% or less of a color pigment, wherein the blowing agent has a diameter of 1-200 µm, has a hollow structure in 50% or more of the volume, and has a thermal conductivity of 0.0001-0.05 W / m·K.

Description

Gasket for refrigerator door

[0001] The present invention relates to a gasket for a refrigerator door with improved insulation properties.

[0002] A refrigerator is a device that maintains food freshness by including a main body with a storage compartment and a cooling air supply system that supplies cold air to the storage compartment. The storage compartment includes a refrigerator compartment, which is maintained at a temperature of approximately 0 to 5°C, for refrigerating food, and a freezer compartment, which is maintained at a temperature of approximately 0 to -30°C, for freezing food. Typically, the storage compartment is designed to have an open front for food entry and exit, and the open front of the storage compartment is opened and closed by a door.

[0003] A refrigerator maintains a low temperature within its storage compartment by operating as follows: First, the compressor draws in refrigerant gas and compresses it. The compressed, heated refrigerant gas passes through the condenser, where it cools and liquefies. The liquefied refrigerant is injected into the evaporator, where it vaporizes, absorbing the heat from the storage compartment and cooling it. The vaporized refrigerant gas is then re-inhaled into the compressor, and through the aforementioned process, it cools the compartment.

[0004] As the temperature inside the refrigerator's storage compartment rises, the compartment is maintained at a low temperature through the operation of the compressor and condenser, as described above. The operating rates of the compressor and condenser are directly related to the refrigerator's power consumption. To reduce power consumption, it is important to minimize the temperature rise inside the storage compartment and lower the operating rates of the compressor and condenser.

[0005] The attached Figure 3 is a diagram illustrating factors that cause temperature rise within a refrigerator storage compartment and the proportion of refrigerator energy lost to maintain the storage compartment at a low temperature for each factor. Referring to Figure 3, the energy loss related to the refrigerator wall insulation is 52%, the energy loss related to the door gasket and its surrounding plastic parts area is 30%, the energy loss related to the defrost heater is 6%, the energy loss related to the fan motor is 6%, and the loss related to the external heater is 6%. Therefore, it is necessary to improve the insulation of the door gasket, which has a high proportion of energy loss.

[0006] One aspect of the present disclosure provides a gasket for a refrigerator door having improved insulation properties.

[0007] 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 art to which the present invention belongs from the description below.

[0008] A gasket for a refrigerator door according to the invention comprises, in wt%, a thermoplastic resin: 30 4 to 60%, a low-molecular plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high-molecular plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%.

[0009] A gasket for a refrigerator door according to the invention comprises: a body disposed between a refrigerator body and a refrigerator door; and a magnet inserted into the body to be attached to and detached from the refrigerator body; wherein the body comprises, in wt%, a thermoplastic resin: 30 to 60%, a low-molecular plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high-molecular plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%, and the magnet comprises, in wt%, a ferrite powder: 40 to 89.5%, a thermoplastic resin: 10 to 40%, and a filler: 0.5 to 20%.

[0010] According to the invention, a gasket for a refrigerator door with improved insulation properties can be provided.

[0011] In addition, according to the idea of ​​the present disclosure, a gasket for a refrigerator door can be provided, which includes a gasket body and a magnet having excellent insulation properties and mechanical properties suitable for a refrigerator door.

[0012] 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.

[0013] FIG. 1 is a photograph of a refrigerator gasket body according to one embodiment of the present disclosure.

[0014] Figure 2 is a diagram showing the heat flow diagram of a refrigerator.

[0015] Figure 3 is a diagram showing factors that cause a rise in temperature within a refrigerator storage compartment and the proportion of energy lost by the refrigerator to maintain the storage compartment at a low temperature for each factor.

[0016] Figure 4 is a perspective view of an open refrigerator.

[0017] Figure 5 is a graph showing the migration resistance according to the content of polymer plasticizer.

[0018] Figure 6 is a photograph of the surface of the body of a gasket taken using a scanning electron microscope (SEM) depending on whether a surface modifier is added.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] First, the structure of a gasket according to one embodiment of the present invention and the operating principle of opening and closing a door will be described with reference to the attached drawings. It should be noted that the gasket structure and drawing symbols in the attached drawings are described solely to aid understanding of the present invention and do not specifically limit the technical spirit of the present invention.

[0024] As illustrated in FIG. 4, the gasket (30) is arranged between the door (20) and the main body (10) of the refrigerator to prevent cold air supplied to the storage compartment from being lost to the outside. Referring to FIG. 1, the gasket (30) is configured with a contact portion (30a) that is pressed against the front of the main body (10) of the refrigerator by the magnetic force of the magnet (33) inserted into the body (31) so that the refrigerator door (20) seals the refrigerator itself, a connecting portion (30b) that is integrally formed at the bottom of the contact portion (30a) and is separated by a partition wall so that a certain space can be formed at the bottom of the contact portion (30a), and an anchor-shaped connecting portion (30c) that is integrally formed at the bottom of the connecting portion (30b) and is inserted and fixed into a connecting groove (22) of the door liner (21) so that the contact portion (30a) and the connecting portion (30b) can be fixed to the door liner (21) of the refrigerator door (20). The air pocket (32) provided by the partition wall at the connection part (30b) serves to absorb shock when the refrigerator door and the refrigerator body come into contact.

[0025] When the refrigerator door (20) with the gasket (30) fixed thereon is closed on the front of the refrigerator body (10) to seal the refrigerator body (10), the magnet (33) inserted into the sealing portion (30a) of the gasket (30) is attached to the outer case (11) of the refrigerator made of a magnetic material, thereby completely blocking the inside of the refrigerator from the outside of the refrigerator. When the door (20) is pulled to separate the refrigerator door (20) from the refrigerator body (10), a tensile load is applied to the door liner (21) of the door (20) to pull the joint portion (30c) of the gasket (30). The connecting portion (30b) formed integrally with the joint portion (30c) is pulled by the tensile load transferred to the joint portion (30c), and the joint portion (30a) into which the magnet (33) is inserted is also pulled. As a result, the adhesive part (30a) attached to the front of the refrigerator body (10) by magnetic force is separated from the outer case (11) of the refrigerator body (10), and the refrigerator body (10) is opened.

[0026] In this way, the gasket (30) used in the refrigerator door (20) is required to meet various conditions due to the characteristics of the refrigerator, and the most important condition among them is, as mentioned above, the insulation function that maintains an airtight state between the refrigerator door (20) and the main body (10) to block cold air leakage from the inside of the refrigerator to the outside and to block heat transfer from the outside of the refrigerator to the inside.

[0027] The solid arrow shown in Fig. 1 is the path through which the heat of the hot line (13) is conducted through the inner case (12), and the dotted arrow shown in Fig. 3 is the path through which cold air is lost between the inner case (12) and the door liner (21). The body (31) of the gasket (30) used in a conventional refrigerator has a thermal conductivity exceeding 0.2 W / m·K, so there is a problem that heat is transferred from the outside to the inside as shown in the solid arrow shown in Fig. 1, or the cold air inside is lost as shown in the dotted arrow shown in Fig. 1, thereby causing energy loss in the refrigerator.

[0028] Accordingly, the present invention relates to a refrigerator door gasket with improved insulation properties to reduce power consumption of the refrigerator, and more particularly, to an invention that improves the insulation properties of a refrigerator door gasket by controlling the composition of the gasket body and the composition of a magnet inserted into the gasket.

[0029]

[0030] A gasket for a refrigerator door according to one embodiment of the present disclosure comprises, in weight %, a thermoplastic resin: 30 to 60%, a low-molecular plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high-molecular plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%.

[0031] Below, the reasons for limiting the composition of the gasket for the refrigerator door are explained in detail.

[0032] Thermoplastic resin: 30 to 60 wt%

[0033] Refrigerator door gaskets are subject to continuous stress as they repeatedly bend and straighten when the door is opened and closed. Therefore, to ensure durability, the body of the refrigerator door gasket should possess sufficient strength and ductility. Furthermore, to ensure the formation of shock-absorbing air pockets, a structure that can accommodate magnets, and smooth door opening and closing, the body of the refrigerator door gasket should possess sufficient profile extrusion properties to enable it to be manufactured into complex shapes.

[0034] According to the present invention, the thermoplastic resin is a soft material suitable for profile extrusion and is actively added to secure the physical properties of the gasket body, such as tensile strength, elongation, and hardness. If the content of the thermoplastic resin added is less than 30 wt%, profile extrusion is difficult and durability is insufficient. On the other hand, if the content exceeds 60 wt%, insulation properties are reduced. Accordingly, the thermoplastic resin may be added in an amount of 30 to 60 wt% in the present invention.

[0035] According to the present invention, the thermoplastic resin is sufficient to ensure that the gasket body has sufficient formability, durability, and surface adhesiveness, and there is no particular limitation on its components.

[0036] The thermoplastic resin may include, for example, one or more of polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), a thermoplastic elastomer (TPE), a thermoplastic vulcanizate (TPV), or a thermoplastic polyolefin (TPO).

[0037] Plasticizer: 20 to 40 wt%

[0038] In the present invention, the plasticizer induces plastic flow of the thermoplastic resin of the polymer described above, thereby facilitating processing such as extrusion and compression molding for manufacturing a gasket. In addition, since the hardness of the gasket composition increases due to the inclusion of the filler described below in the present invention, the plasticizer is actively added to impart processability.

[0039] If the plasticizer content is less than 20 wt%, there is a problem of not being able to secure ductility suitable for extrusion. On the other hand, if the content exceeds 40 wt%, there is a problem of reduced thermal conductivity. Accordingly, in the present invention, the plasticizer may be added in an amount of 20 to 40 wt%.

[0040] Meanwhile, since plasticizers are usually highly volatile in high-temperature and high-humidity environments and have a high transferability to other substances by decomposition, it may be considered to improve insulation performance by limiting the types of plasticizers to increase the mechanical properties.

[0041] The plasticizer of the present invention comprises 15 to 30 wt% of a low molecular weight plasticizer having a weight average molecular weight of less than 500 and 5 to 10 wt% of a high molecular weight plasticizer having a weight average molecular weight of 500 or more.

[0042] The molecular weight is usually less than 500 as shown below, and DOP, which is used as a representative plasticizer, has a molecular weight of 391, and DINP has a molecular weight of 419. Such low-molecular plasticizers transfer organic substances to the inner surface of the refrigerator, which is the counterpart in high temperature and high humidity conditions, and this causes damage to the appearance. To solve this problem, the use of a high-molecular plasticizer is necessary. However, it is difficult to manufacture with only a high-molecular plasticizer due to the increase in viscosity, so it is necessary to find the optimal point, and through this, the connection between molecules is also increased, making it possible to improve the mechanical properties. Therefore, a high-molecular plasticizer can be added at 5 to 10 wt%.

[0043] The low molecular weight plasticizer of the present invention may include at least one of dioctyl phthalate (DOP), dioctyl adipate (DOA), diisodecyl phthalate (DIDP), or trioctyl trimellitate (TOTM).

[0044] The polymer plasticizer of the present invention may include at least one of ESBO (Epoxized Soy Bean Oil) or ELO (Epoxized Linseed Oil).

[0045] Filler: 1 to 30 wt%

[0046] In the present invention, the filler is an important component that lowers the thermal conductivity of the refrigerator door gasket body, thereby improving its insulation properties. The filler has a thermal conductivity of 0.0001 to 0.2 W / m K, and has lower thermal conductivity than the aforementioned plasticizer and thermoplastic resin, thereby improving the insulation properties of the gasket body.

[0047] According to the present invention, filler is added in an amount of at least 1 wt% to lower thermal conductivity. However, excessive addition may degrade the mechanical properties of the gasket body, such as tensile strength, elongation, and hardness, thereby reducing durability. Considering this, the upper limit of the filler added to the gasket body in the present invention is preferably limited to 30 wt%.

[0048] The filler according to the present invention is provided with one or more hollow particles or porous materials having a diameter of 1 to 100 μm, at least 50% of the volume, and the thermal conductivity of the filler may be 0.0001 to 0.2 W / m·K. Examples of the filler are described below.

[0049] According to one embodiment of the present invention, a filler may be provided with one or more hollow particles having a diameter of 1 to 100 μm, with at least 50% of the volume being comprised of the particles. As used herein, the term "hollow particle" is interpreted as a particle having an outer shell that forms closed pores within the particle. The outer shell of the hollow particle may be composed of silica, but is not necessarily limited thereto.

[0050] According to the present invention, in order to increase the thermal insulation properties of the hollow particles, an insulating material having low thermal conductivity may be filled within the pores of the hollow particles. For example, an insulating material having a thermal conductivity of 0.03 W / m K or less may be filled within the pores. For the purpose of sufficiently lowering the thermal conductivity, the insulating material may be filled within the pores at a filling ratio of 10 to 60%. In this specification, the "filling ratio" is interpreted as the volume of the material being filled relative to the total volume of the pores, converted into a percentage. Since a higher filling ratio is advantageous in terms of thermal insulation properties, the lower limit of the filling ratio may be preferably 20%, and more preferably 30%. However, since there is a concern that mechanical properties such as tensile strength may deteriorate when the filling ratio is high, the upper limit of the filling ratio may be preferably 50%.

[0051] In addition, in order to increase the insulation properties of the hollow particles, the pores of the hollow particles may be in a vacuum state. In the present invention, the vacuum state means a complete vacuum state or a partial vacuum state, and it is preferable to increase the degree of vacuum in order to lower the thermal conductivity. Accordingly, the partial vacuum state is a high vacuum section (10 -4 Torr ~ 10 -7 Torr) in the ultra-high vacuum range (10 -10 It is desirable that it be less than 1 Torr.

[0052] Meanwhile, if the aforementioned insulating material is in a liquid or solid state, a vacuum pump or similar device can be used to create a vacuum outside of the area filled with the insulating material. This method offers the advantage of reducing manufacturing costs while also lowering thermal conductivity, compared to increasing the vacuum level.

[0053] According to another embodiment of the present invention, the filler may be formed of a porous material. As used herein, "porous material" is interpreted as a material containing one or more closed pores. Examples of porous materials include, but are not necessarily limited to, porous ceramic materials.

[0054] According to the present invention, in order to increase the thermal insulation properties of a porous material, an insulating material having low thermal conductivity may be filled within the pores of the porous material. For example, an insulating material having a thermal conductivity of 0.03 W / m K or less may be filled within the pores. In order to sufficiently lower the thermal conductivity, the insulating material may be filled within the pores at a filling ratio of 10 to 60%. Since a higher filling ratio is advantageous in terms of thermal insulation properties, the lower limit of the filling ratio may be preferably 20%, and more preferably 30%. However, since there is a concern that mechanical properties such as tensile strength may deteriorate when the filling ratio is high, the upper limit of the filling ratio may be preferably 50%.

[0055] In addition, in order to increase the insulation properties of the porous material, the pores of the porous material may be in a vacuum state. In the present invention, the vacuum state means a complete vacuum state or a partial vacuum state, and it is preferable to increase the degree of vacuum in order to lower the thermal conductivity. Accordingly, the partial vacuum state is a high vacuum section (10 -4 Torr ~ 10 -7 Torr) in the ultra-high vacuum range (10 -10 It is desirable that it be less than 1 Torr.

[0056] Meanwhile, if the aforementioned insulating material is in a liquid or solid state, a vacuum pump or similar device can be used to create a vacuum outside of the area filled with the insulating material. This method offers the advantage of reducing manufacturing costs while also lowering thermal conductivity, compared to increasing the vacuum level.

[0057] According to the present invention, the porous material preferably includes a large number of pores so that an insulating material can be filled therein or the interior can be treated in a vacuum state. In one example, the porosity of the porous material may be 10 to 60%. Here, "porosity" refers to the percentage of the volume occupied by pores in the porous material relative to the total volume of the porous material. Since a higher porosity is advantageous in terms of insulation properties, the lower limit of the porosity may be preferably 20%, and more preferably 30%. However, since there is a concern that mechanical properties such as tensile strength may deteriorate when the porosity of the porous material is high, the upper limit of the porosity may be preferably 50%.

[0058] Meanwhile, as mentioned above, the gasket can be manufactured by extrusion, compression molding, etc., and in order for the filler to maintain a hollow state during the manufacturing process mentioned above, the filler is provided to have a pressure strength of 500 to 20,000 PSI, and more preferably, it can be provided to have a pressure strength of 3,000 to 6,000 PSI.

[0059] While two embodiments of the filler according to the present invention have been described above, the technical concept of the present invention is not necessarily limited to these examples. Various materials that can be filled with insulating materials and have a closed space capable of maintaining a vacuum inside can be used as the filler of the present invention.

[0060] The filler is present in the gasket composition as shown in the attached drawing 6. As described above, the thermal conductivity of the filler can be lowered by filling the pores of the filler with an insulating material having low thermal conductivity or by controlling the pores to a vacuum state. Therefore, the higher the volume occupied by the filler in the overall composition, the lower the thermal conductivity of the material.

[0061] The refrigerator door gasket of the present invention may contain additional additives in addition to the composition described above. The additives may include one or more of a stabilizer, a lubricant, a reinforcing agent, an antibacterial agent, and a pigment. Each component is described below.

[0062] Stabilizers are added to improve the stability of refrigerator door gaskets against heat, oxygen, ultraviolet rays, etc. For example, the stabilizers may be heat-resistant stabilizers such as sodium stearate, calcium stearate, and epoxidized soybean oil; cold-resistant stabilizers such as butylene laurate complexes; and weather-resistant stabilizers such as organic phosphorous ester complexes. The stabilizers may be included in an amount of 4 wt% or less.

[0063] Lubricants are added to improve the surface finish of molded and extruded gaskets and to facilitate pigment dispersion. Examples of lubricants include fatty alcohols, fatty acids, and fatty acid amides.

[0064] Reinforcing agents are added to improve the mechanical strength, dimensional stability, heat distortion temperature, hardness, and other physical properties of gaskets. For example, the reinforcing agent may be a calcium carbonate (CaCO3)-based reinforcing agent.

[0065] An antimicrobial agent may be added to prevent the growth of mold or bacteria due to migration of the plasticizer. The antimicrobial agent may be included in an amount of 1% by weight or less.

[0066] Pigments may be added to obtain a desired color for the gasket body. For example, the pigments may be titanium oxide, carbon black, violet, etc. The pigments may be included in an amount of 1 wt% or less.

[0067] The refrigerator door gasket of the present invention, having the composition described above, includes a filler, thereby improving thermal insulation to a thermal conductivity of 0.2 W / m·K or less. Accordingly, the energy efficiency of the refrigerator can be improved by reducing cold air loss due to the gasket.

[0068] A gasket for a refrigerator door according to another embodiment of the present disclosure may include 15 to 30 wt% of polyvinyl chloride as a thermoplastic resin, 15 to 30 wt% of a thermoplastic elastomer, 15 to 30 wt% of a low-molecular plasticizer having a weight average molecular weight of less than 500, 5 to 10 wt% of a high-molecular plasticizer having a weight average molecular weight of 500 or more, and 1 to 30 wt% of a filler.

[0069] For refrigerator gaskets to withstand repeated physical stresses, they must be able to recover stress within the elastic range. In this regard, polyvinyl chloride (PVC) exhibits poor properties. Furthermore, when fillers are added for insulation, the higher the filler content, the lower the gasket's mechanical properties, such as tensile strength, elongation, and hardness.

[0070] Therefore, in order to improve the aforementioned deterioration of physical properties that may occur when using polyvinyl chloride as a thermoplastic resin and the deterioration of physical properties due to increased filler content, a thermoplastic resin may be included in which 15 to 30 wt% of polyvinyl chloride is mixed with 15 to 30 wt% of a thermoplastic elastomer. When polyvinyl chloride and a thermoplastic elastomer are mixed in such a ratio, the basic physical properties of the thermoplastic resin can be increased and the deterioration of physical properties of the gasket described above can be prevented.

[0071] The thermoplastic resin may include polyethylene (PE), polypropylene (PP), etc. in addition to the aforementioned polyvinyl chloride, and the elastomer may include one or more of styrene butadiene rubber, chloroprene rubber, silicone, thermoplastic polyurethane, thermoplastic vulcanizate, thermoplastic polyolefin, or thermoplastic styrene.

[0072] Descriptions of plasticizers, fillers, and other additives are omitted as they are as described above.

[0073] The refrigerator door gasket of the present invention having the above-described composition includes a thermoplastic resin mixed with an elastomer, thereby improving tensile strength and also improving insulation with a thermal conductivity of 0.2 W / m·K or less, thereby reducing cold air loss due to the gasket and improving the energy efficiency of the refrigerator.

[0074] A gasket for a refrigerator door according to another embodiment of the present disclosure may include: 0.5 to 5 wt% of a surface modifier; 30 to 60 wt% of a thermoplastic resin; 15 to 30 wt% of a low-molecular plasticizer having a weight average molecular weight of less than 500; 5 to 10 wt% of a high-molecular plasticizer having a weight average molecular weight of 500 or more; and 1 to 30 wt% of a filler.

[0075] As described above, fillers can be added to improve insulation, but as the amount of filler added increases, the mechanical properties of the gasket body, such as tensile strength, elongation, and hardness, may deteriorate, potentially leading to poor durability. That is, as the amount of filler added increases, an interface is created between the organic thermoplastic resin and the inorganic filler, and the deterioration of mechanical properties, such as tensile strength, may increase due to interfacial separation.

[0076] Therefore, to solve this problem, the gasket can improve mechanical properties such as tensile strength by including a surface modifier to enhance the adhesion between the organic thermoplastic resin and the inorganic filler. The surface modifier can include one or more of a silane coupling agent, a titanate coupling agent, or a zirconate coupling agent.

[0077] For example, in the case of a silane coupling agent, the alkoxysilyl group (Si-OR), which improves degradation due to interfacial separation, is hydrolyzed by water or moisture to become a silanol group (Si-OH). This silanol group and the inorganic surface combine through a condensation reaction, thereby increasing the bonding strength, and another reactive group of the silane coupling agent, which chemically bonds with the organic material, combines or compatibilizes with the organic material, resulting in chemical bonding of the inorganic material and the organic material. Through this, the surface modifier increases the bonding strength between the organic thermoplastic resin and the inorganic filler, thereby improving mechanical properties such as tensile strength even when the amount of filler added increases.

[0078] The surface modifier of the present invention may be added in an amount of 0.5 wt% or more to prevent deterioration of mechanical properties due to the addition of filler. If the amount is excessively low, the effect of the surface modifier addition will not be apparent, so the lower limit of the surface modifier is set at 0.5 wt%. However, excessive addition may cause problems such as increased costs, overprocessing, adhesion between the objects to be treated, and difficulty in drying. Therefore, the upper limit of the surface modifier is preferably limited to 5 wt%.

[0079] These surface modifiers can be added directly to the inorganic surface or mixed simultaneously during mixing. Considering the manufacturing process and workability, the method of adding simultaneously during mixing is preferable.

[0080] However, because these surface modifiers have high molecular weights, their dispersibility may deteriorate when added during mixing. To prevent this deterioration in dispersibility and ensure uniform dispersion, the amount added or the mixing time may need to be increased. To prevent this deterioration in dispersibility and ensure efficient dispersion of the surface modifier, the molecular weight (g / mol) of the surface modifier may be limited to 100 to 500 g / mol.

[0081] The gasket body for a refrigerator door of the present invention having the composition described above includes a surface modifier, thereby improving tensile strength by 100% on average compared to when the surface modifier is not included, although this may vary depending on the content of the filler, and also improving thermal insulation to a thermal conductivity of 0.2 W / m·K or less. Accordingly, it is possible to reduce cold air loss due to the gasket, thereby improving the energy efficiency of the refrigerator.

[0082] A gasket (30) for a refrigerator door according to another embodiment of the present disclosure comprises: a body (31) disposed between a refrigerator body (10) and a refrigerator door (20);

[0083] It includes a magnet (33) that is inserted into the above body (31) and is provided to be attached to and detached from the refrigerator body (10);

[0084] The above body (31) comprises, in weight %, a thermoplastic resin: 30 to 60%, a low-molecular plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high-molecular plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%.

[0085] The above magnet (33) contains, in weight %, ferrite powder: 40 to 89.5%, thermoplastic resin: 10 to 40%, and filler: 0.5 to 20%.

[0086] The insertion form of the magnet is not particularly limited, and it is sufficient for the magnet to be inserted into the gasket body so that it can be attached to and detached from the outer case of the refrigerator body made of a magnetic material by the magnet's magnetism. According to an example, the magnet may be inserted so that the body surrounds the entire surface of the magnet, or the magnet may be inserted so that one surface of the magnet is exposed toward the refrigerator body and surrounds the remaining surface except for the exposed surface.

[0087] Below, the reasons for limiting the magnet composition of the gasket for the refrigerator door are explained in detail.

[0088] Ferrite powder: 40 to 89.5 wt%

[0089] Ferrite powder is a key component that makes a magnet magnetic. Considering this, in the present invention, ferrite powder is actively added, and the lower limit of addition for making the magnet magnetic may be 40 wt%. The composition of the ferrite powder may be variously adjusted considering the strength of the magnetism. However, considering the content of the filler added to improve the above-mentioned insulation properties and the thermoplastic resin component added considering the impact properties, the upper limit of addition of the ferrite powder may be 89.5 wt%.

[0090] According to one example of the present invention, the ferrite powder may include one or more of strontium-based ferrite oxide powder (Sr-ferrite oxide powder), barium-based ferrite oxide powder (Ba-ferrite oxide powder), and rare earth-based powder.

[0091] Thermoplastic resin: 10 to 40 wt%

[0092] Thermoplastic resin is added to ensure sufficient durability, including impact resistance, of the magnet. Considering this, the thermoplastic resin is added in an amount of at least 10% by weight in the present invention. However, if the thermoplastic resin exceeds 40% by weight, there is a risk of reduced insulation properties. Accordingly, the thermoplastic resin may be added in an amount of 10 to 40% by weight in the present invention.

[0093] According to one example of the present invention, the thermoplastic resin may include one or more of polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS), polyamide (PA), and chlorinated polyethylene (CPE).

[0094] Filler: 0.5 to 20 wt%

[0095] In the present invention, the filler is an important component that lowers the thermal conductivity of the refrigerator door magnet and improves its insulation properties. The filler has a thermal conductivity of 0.0001 to 0.2 W / m·K, and has lower thermal conductivity than the aforementioned ferrite powder and thermoplastic resin, thereby improving the insulation properties of the magnet.

[0096] According to the present invention, filler is added in an amount of 0.5 wt% or more to lower thermal conductivity. However, excessive addition may deteriorate the mechanical properties of the magnet, including its impact resistance, resulting in poor durability and insufficient magnetic properties. Considering this, the upper limit of the filler added to the magnet in the present invention is preferably limited to 20 wt%.

[0097] Since the example of the filler added to the magnet is the same as described above, a detailed description is omitted for convenience.

[0098] According to one example of the present invention, the filler may be provided as one or more hollow particles or porous materials having a diameter of 1 to 100 μm.

[0099] According to the present invention, in order to increase the thermal insulation properties of the filler, an insulating material having a thermal conductivity of 0.03 W / m K or less may be filled in the pores of the hollow particles or the pores of the porous material. In order to sufficiently lower the thermal conductivity, the insulating material may be filled in the pores at a filling ratio of 10 to 60%. Since a higher filling ratio is advantageous in terms of thermal insulation properties, the lower limit of the filling ratio may be preferably 20%, and more preferably 30%. However, since there is a concern that mechanical properties such as tensile strength may deteriorate when the filling ratio is high, the upper limit of the filling ratio may be preferably 50%.

[0100] Additionally, to enhance the insulation properties of the filler, the pores of the hollow particles or the pores of the porous material can be vacuumed. If the insulating material is liquid or solid, a vacuum pump or similar device can be used to create a vacuum outside of the area filled with the insulating material. This approach offers the advantage of reducing manufacturing costs while also lowering thermal conductivity, compared to increasing the degree of vacuum.

[0101] According to the present invention, the porous material preferably includes a large number of pores so that the material can be filled with an insulating material or the interior can be treated in a vacuum state. For example, the porosity of the porous material may range from 10% to 60%. Since a higher porosity is advantageous in terms of insulation, the lower limit of the porosity may be preferably 20%, and more preferably 30%. However, since a high porosity of the porous material may deteriorate mechanical properties such as tensile strength, the upper limit of the porosity may be preferably 50%.

[0102] The refrigerator door magnet of the present invention may further include a binder and a pigment in addition to the composition described above.

[0103] A binder is added to improve extrusion moldability when mixing the above-described composition and then extruding it. For example, the binder may be chlorinated rubber, etc.

[0104] Pigments are added to obtain the desired color of the magnet. Examples of pigments include titanium dioxide, carbon black, and violet.

[0105] The refrigerator door magnet of the present invention having the above-described composition has improved thermal insulation properties with a thermal conductivity of 1 W / m·K or less. Accordingly, energy efficiency can be improved by reducing cold air loss due to the gasket.

[0106] In addition, the magnet of the refrigerator door gasket according to the present invention has excellent insulation properties and can have a magnetic force of 70 g / 50 mm or more, so that it can have a magnetic force suitable as a magnet of the refrigerator door gasket.

[0107] The present invention can provide a refrigerator including the gasket for the refrigerator door described above. According to the present invention, a refrigerator can be provided including a main body forming a storage compartment, a door configured to open and close the storage compartment, and a gasket according to the above-described embodiment, which is disposed between the main body and the door.

[0108] Hereinafter, the present invention will be described in more detail through examples. However, it should be noted that the following examples are intended only to illustrate and further illustrate the present invention and are not intended to limit the scope of the invention. This is because the scope of the invention is determined by the matters set forth in the patent claims and matters reasonably inferred therefrom.

[0109] {Example}

[0110] The body composition of a refrigerator door gasket having the composition described in Table 1 below was mixed, compounded, extruded, and then molded to manufacture a body of a refrigerator door gasket. The extrusion molding temperature at this time was 140 to 200°C. The thermal conductivity, tensile strength, elongation, and hardness of the manufactured body were measured and are shown in Table 1.

[0111] ClassificationThermoplastic resin (wt%)Plasticizer (wt%)Filler (wt%)Additive (wt%)Thermal conductivity (W / m K)Mechanical propertiesTotal high molecular weightLow molecular weightTensile strength (kgf / mm) 2 ) Elongation (%) Hardness (Hs) Comparative Example 160 350.035.005.00.241.538064 Invention Example 157 353.032.035.00.191.337065 Invention Example 252.5358.027.07.55.00.161.136067 Invention Example 345 3511.024.0155.00.140.825068 Invention Example 442.53515.020.017.55.00.120.721068 Invention Example 530 3520.015.0305.00.100.515070

[0112] Referring to Table 1, it can be confirmed that the thermal insulation performance is improved by satisfying the composition range of the refrigerator door gasket body limited in the present invention, and the thermal conductivity is 0.2 W / m K or less. In addition, while the thermal insulation performance is excellent, it is 0.5 kgf / mm 2 It can be confirmed that it has mechanical properties suitable for a gasket body for a refrigerator door, satisfying the above tensile strength, elongation of 150% or more, and hardness of 60 to 70Hs.

[0113] A magnet composition for a refrigerator door gasket having the composition described in Table 2 below was mixed, compounded, extruded, and then molded to manufacture a magnet for a refrigerator door gasket. The thermal conductivity and magnetic force of the manufactured magnet were measured and are shown in Table 2.

[0114] Ferrite powder (weight%) Thermoplastic resin (weight%) Filler (weight%) Thermal conductivity (W / m K) Magnetic force (g / 50mm) Invention example 689.5100.51100 Invention example 787.5102.50.9585 Invention example 8851050.980 Invention example 982.5107.50.8575 Invention example 108010100.870

[0115] Referring to Table 2, it can be confirmed that the composition range of the magnet of the refrigerator door gasket limited in the present invention is satisfied, and the thermal conductivity is 1 W / m K or less, thereby improving the insulation properties. In addition, it can be confirmed that the magnet has a magnetic force of 70 g / 50 mm or more while maintaining excellent insulation properties, thereby having a magnetic force suitable for use as a magnet of the refrigerator door gasket.

[0116] Table 3 below evaluates the improvement in the migration resistance of gaskets according to the use of polymer plasticizers.

[0117] The migration resistance evaluation is conducted and evaluated in the following manner, and the migration resistance can be confirmed according to changes in the content of polymer plasticizer.

[0118] 1) Test method: Leave the two materials in contact in a constant temperature and humidity chamber at 60℃, 95% (6 Hr).

[0119] 2) Evaluation method: Visual evaluation (proceed with the 2 levels of inspection below)

[0120] - Final non-performance score: number of lines x weight

[0121] Level 1 inspection: degree of visual inspection without reflection by light (weight: 1.0)

[0122] Level 2 inspection: degree of visual detection through light reflection (weight 0.5)

[0123] Polymer Plasticizer Content (Wt%) 0 %2 %5 %6 %8 %10 %15 %20 %1 Level 4 x 14 x 10000002 Level 8 x 0.55 x 0.57 x 0.56 X 0.55 x 0.54 x 0.52 x 0.51 x 0.5 Total Score 86.53.53.02.52.01.00.5

[0124] Referring to Table 3 and Figure 5 above, it can be confirmed that the higher the polymer plasticizer content up to 20 wt%, the lower the evaluation score, indicating superior migration resistance.

[0125] Table 4 below is an example of blending an elastomer with a thermoplastic resin.

[0126] The body composition of a refrigerator door gasket having the composition described in Table 4 was mixed, compounded, extruded, and then molded to produce a body of a refrigerator door gasket. The extrusion molding temperature at this time was 140 to 200°C. The thermal conductivity and tensile strength of the manufactured body were measured and are shown in Table 4.

[0127] Classification Thermoplastic resin (wt%) Elastomer (wt%) Plasticizer (wt%) Filler (wt%) Additive (wt%) Thermal conductivity (W / m·K) Tensile strength (kgf / mm) 2 ) Total high molecular weight low molecular weight invention example 1110.042.5358.027.07.55.00.161.5 invention example 1230.022.5358.027.07.55.00.161.2

[0128] Inventive Example 11 is an example in which the remaining composition is the same as that of Inventive Example 2 except for the thermoplastic resin, and 42.5 wt% of elastomer is added, and Inventive Example 12 is an example in which 22.5 wt% of elastomer is added compared to Inventive Example 2, and it can be confirmed that the tensile strength increases due to the addition of the elastomer.

[0129] Table 5 below is an example of a case where a surface modifier is further added.

[0130] The body composition of a refrigerator door gasket having the composition described in Table 5 was mixed, compounded, extruded, and then molded to manufacture a body of a refrigerator door gasket. The extrusion molding temperature at this time was 140 to 200°C. The thermal conductivity and tensile strength of the manufactured body were measured and are shown in Table 5.

[0131] Classification Thermoplastic resin (wt%) Plasticizer (wt%) Filler (wt%) Additive (wt%) Surface modifier (wt%) Thermal conductivity (W / m·K) Tensile strength (kgf / mm) 2 ) Total high molecular weight low molecular weight invention example 1357353.032.034.01.00.191.4 invention example 1452.5358.027.07.54.01.00.161.2 invention example 15453511.024.0154.01.00.140.9 invention example 1642.53515.020.017.54.01.00.120.8 invention example 17303520.015.0304.01.00.100.6

[0132] Invention Examples 13 to 17 are examples in which the remaining composition is the same as that of Invention Examples 1 to 5, except for the additive content, and 1.0 wt% of a surface modifier is added. It can be confirmed that the tensile strength increases due to the inclusion of the surface modifier.

[0133] The disclosed embodiments have been described with reference to the attached drawings and tables as described above. Those skilled in the art will understand that the present invention can be implemented in forms other than the disclosed embodiments without altering the technical spirit or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

[0134] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, comprising, by weight %, a thermoplastic resin: 30 to 60%, a low-molecular plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high-molecular plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%.

[0135] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided in which the filler is provided with one or more hollow particles or porous materials having a diameter of 1 to 100 μm or more, with a volume of 50% or more, and the filler has a thermal conductivity of 0.0001 to 0.2 W / m·K.

[0136] According to one aspect of the present disclosure, a gasket for a refrigerator door having a thermal conductivity of 0.03 W / m·K or less can be provided within the pores of the hollow particles or the pores of the porous material.

[0137] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided wherein the pressure strength of the filler is 500 to 20,000 PSI.

[0138] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, wherein the thermoplastic resin includes at least one of polyvinyl chloride, polyethylene, polypropylene, a thermoplastic elastomer, a thermoplastic vulcanizate, or a thermoplastic polyolefin.

[0139] According to one aspect of the present disclosure, the thermoplastic resin can provide a gasket for a refrigerator door comprising 15 to 30% of polyvinyl chloride and 15 to 30% of thermoplastic elastomer.

[0140] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, wherein the thermoplastic elastomer comprises at least one of styrene butadiene rubber, chloroprene rubber, silicone, thermoplastic polyurethane, thermoplastic vulcanizate, thermoplastic polyolefin, or thermoplastic styrene.

[0141] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided further comprising 0.5 to 5% of a surface modifier.

[0142] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided in which the molecular weight of the surface modifier is 100 to 1000 g / mol.

[0143] According to one aspect of the present disclosure, the low molecular weight plasticizer can provide a gasket for a refrigerator door comprising at least one of dioctyl phthalate, dioctyl adipate, diisodecyl phthalate, or trioctyl trimellitate.

[0144] According to one aspect of the present disclosure, the polymer plasticizer can provide a gasket for a refrigerator door comprising at least one of ESBO (Epoxized Soy Bean Oil) and ELO (Epoxized Linseed Oil).

[0145] According to one aspect of the present disclosure, there is provided a body disposed between a refrigerator body and a refrigerator door;

[0146] A magnet is inserted into the body and is provided to be attached to and detached from the refrigerator body;

[0147] The above body comprises, in weight %, a thermoplastic resin: 30 to 60%, a low molecular weight plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high molecular weight plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%.

[0148] The above magnet can provide a gasket for a refrigerator door, which comprises, by weight %, ferrite powder: 40 to 89.5%, thermoplastic resin: 10 to 40%, and filler: 0.5 to 20%.

[0149] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, wherein each of the fillers is provided with one or more hollow particles or porous materials having a diameter of 1 to 100 μm, at least 50% of the volume of which, and the thermal conductivity of the fillers is 0.0001 to 0.2 W / m·K, respectively.

[0150] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, in which the pores of the hollow particles or the pores of the porous material are filled with an insulating material having a thermal conductivity of 0.03 W / m·K or less.

[0151] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, wherein the pressure strength of the fillers is 500 to 20,000 PSI, respectively.

[0152] According to one aspect of the present disclosure, the thermoplastic resin can provide a gasket for a refrigerator door comprising 15 to 30% of polyvinyl chloride and 15 to 30% of elastomer.

[0153] According to one aspect of the present disclosure, the elastomer may provide a gasket for a refrigerator door comprising at least one of styrene butadiene rubber, chloroprene rubber, silicone, thermoplastic polyurethane, thermoplastic vulcanizate, thermoplastic polyolefin, or thermoplastic styrene.

[0154] According to one aspect of the present disclosure, a gasket for a refrigerator door can be provided, which further comprises 0.5 to 5% of a surface modifier, wherein the molecular weight of the surface modifier is 100 to 500 g / mol.

[0155] According to one aspect of the present disclosure, the low molecular weight plasticizer can provide a gasket for a refrigerator door comprising at least one of dioctyl phthalate, dioctyl adipate, diisodecyl phthalate, or trioctyl trimellitate.

[0156] According to one aspect of the present disclosure, the polymer plasticizer can provide a gasket for a refrigerator door comprising at least one of ESBO (Epoxized Soy Bean Oil) and ELO (Epoxized Linseed Oil).

[0157] Above, a gasket for a refrigerator door according to one embodiment has been described.

[0158] (Explanation of symbols)

[0159] 10: Body

[0160] 11: External case

[0161] 12: Inner case

[0162] 13: Hotline

[0163] 20: Door

[0164] 21: Doorliner

[0165] 22: Combination Home

[0166] 30: Gasket

[0167] 30a: Adhesive

[0168] 30b: Connection

[0169] 30c: Joint

[0170] 31: Body

[0171] 32: Air pocket

[0172] 33: Magnet

Claims

1. A gasket for a refrigerator door, comprising: 30 to 60% by weight of a thermoplastic resin, 15 to 30% by weight of a low-molecular plasticizer having a weight-average molecular weight of less than 500, 5 to 20% by weight of a high-molecular plasticizer having a weight-average molecular weight of 500 or more, and 1 to 30% by weight of a filler.

2. In claim 1, A gasket for a refrigerator door, wherein the filler is provided with one or more hollow particles or porous materials having a diameter of 1 to 100 ㎛, at least 50% of the volume thereof, and the thermal conductivity of the filler is 0.0001 to 0.2 W / m K.

3. In claim 2, A gasket for a refrigerator door, wherein the pores of the hollow particles or the pores of the porous material are filled with an insulating material having a thermal conductivity of 0.03 W / m K or less.

4. In claim 1, A gasket for a refrigerator door, wherein the pressure strength of the above filler is 500 to 20,000 PSI.

5. In claim 1, A gasket for a refrigerator door, wherein the thermoplastic resin comprises at least one of polyvinyl chloride, polyethylene, polypropylene, a thermoplastic elastomer, a thermoplastic vulcanizate, or a thermoplastic polyolefin.

6. In claim 1, A gasket for a refrigerator door, wherein the thermoplastic resin comprises 15 to 30% of polyvinyl chloride and 15 to 30% of thermoplastic elastomer.

7. In claim 6, A gasket for a refrigerator door, wherein the thermoplastic elastomer comprises at least one of styrene butadiene rubber, chloroprene rubber, silicone, thermoplastic polyurethane, thermoplastic vulcanizate, thermoplastic polyolefin, or thermoplastic styrene.

8. In claim 1, A gasket for a refrigerator door, further comprising 0.5 to 5% of a surface modifier.

9. In claim 8, A gasket for a refrigerator door, wherein the molecular weight of the surface modifier is 100 to 1000 g / mol.

10. In claim 1, A gasket for a refrigerator door, wherein the low molecular weight plasticizer comprises at least one of dioctyl phthalate, dioctyl adipate, diisodecyl phthalate, or trioctyl trimellitate.

11. In claim 1, A gasket for a refrigerator door, wherein the polymer plasticizer comprises at least one of ESBO (Epoxized Soy Bean Oil) and ELO (Epoxized Linseed Oil).

12. A body placed between the refrigerator body and the refrigerator door; A magnet is inserted into the body and is configured to be attached to and detached from the refrigerator body; The above body comprises, in weight %, a thermoplastic resin: 30 to 60%, a low molecular weight plasticizer having a weight average molecular weight of less than 500: 15 to 30%, a high molecular weight plasticizer having a weight average molecular weight of 500 or more: 5 to 20%, and a filler: 1 to 30%. A gasket for a refrigerator door, wherein the magnet comprises, in weight %, 40 to 89.5% of ferrite powder, 10 to 40% of thermoplastic resin, and 0.5 to 20% of filler.

13. In claim 12, A gasket for a refrigerator door, wherein each of the above fillers is provided with one or more hollow particles or porous materials having a diameter of 1 to 100 ㎛, wherein 50% or more of the volume of the above fillers is provided, and the thermal conductivity of the fillers is 0.0001 to 0.2 W / m K, respectively.

14. In claim 13, A gasket for a refrigerator door, wherein the pores of the hollow particles or the pores of the porous material are filled with an insulating material having a thermal conductivity of 0.03 W / m K or less.

15. In claim 12, A gasket for a refrigerator door, wherein the pressure strength of the above fillers is 500 to 20,000 PSI respectively.

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