Urethane and refrigerator comprising same

Abstract

A refrigerator according to an embodiment disclosed herein may comprise: a cavity forming a storage chamber; a cabinet coupled to the outside of the cavity; and a heat insulating material provided between the cavity and the cabinet. The heat insulating material may include: a polyol system including an aliphatic polyol and an aromatic polyol; an isocyanate; and perfluoro polyether (PFPE). The heat insulating material may have 40 to 60 parts by weight of the aliphatic polyol per 100 parts by weight of the polyol system. The heat insulating material may have 40 to 60 parts by weight of the aromatic polyol per 100 parts by weight of the polyol system. The heat insulating material may have 0.2 to 0.4 parts by weight of the PFPE per 100 parts by weight of the polyol system.

Description

Urethane and refrigerators containing the same

[0001] Various embodiments of the present disclosure relate to urethane and refrigerators containing the same.

[0002] A refrigerator is a home appliance that keeps food fresh by having a main body having a storage compartment and a cold air supply device that supplies cold air to the storage compartment. The storage compartment includes a refrigerator compartment that refrigerates food by maintaining it at approximately 0 to 5 degrees Celsius, and a freezer compartment that freezes food by maintaining it at approximately 0 to minus 30 degrees Celsius. The storage compartment is designed so that the front is open for the retrieval and retrieval of food.

[0003] Insulating material is provided between the outer cabinet and the inner cavity of a refrigerator. Generally, urethane used as an insulating material is injected in liquid form between the refrigerator's outer cabinet and inner cavity and forms a wall in a hardened state. The lowest thermal conductivity limit of conventional urethane insulation is approximately 20 mW / m·K, making it difficult to meet stricter environmental regulations.

[0004] One way to enhance the insulation effect of the insulation material is to increase the thickness of the urethane. However, increasing the thickness of the urethane results in problems such as an increase in the size of the refrigerator or a decrease in storage capacity.

[0005] Therefore, to satisfy environmental regulations and minimize consumer inconvenience, it is necessary to develop high-performance urethane with lower thermal conductivity compared to existing materials.

[0006] The information described above may be provided as related art for the purpose of aiding understanding of the present disclosure. No claim or determination is made as to whether any of the foregoing may be applied as prior art related to the present disclosure.

[0007] A refrigerator according to one embodiment of the present disclosure may include an inner body forming a storage compartment, an outer body coupled to the outside of the inner body, and an insulating material provided between the inner body and the outer body. The insulating material may include a polyol system comprising an aliphatic polyol and an aromatic polyol, an isocyanate, and PFPE (Perfluoro Polyether). The aliphatic polyol may have an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The aromatic polyol may have an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The PFPE may have an amount of 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system.

[0008] A urethane according to one embodiment of the present disclosure may comprise a polyol system comprising an aliphatic polyol and an aromatic polyol, an isocyanate, and PFPE. The aliphatic polyol may have an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The aromatic polyol may have an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The PFPE may have an amount of 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system.

[0009] A method for manufacturing urethane according to one embodiment of the present disclosure may include a urethane polymer formation process in which a polyol system and an isocyanate are reacted, a cell formation process in which a blowing agent, a foaming agent and / or a catalyst are added for cell formation, and a cell homogenization process in which PFPE is added to reduce the average diameter and dispersion of the cells.

[0010] However, the problems to be solved in this disclosure are not limited to those mentioned above, and may be determined in various ways without departing from the spirit and scope of this disclosure.

[0011] In relation to the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0012] FIG. 1 is a perspective view of a refrigerator according to one embodiment of the present disclosure.

[0013] FIG. 2 is a perspective view of a refrigerator according to one embodiment of the present disclosure.

[0014] FIG. 3 is a cross-sectional view of a refrigerator according to one embodiment of the present disclosure.

[0015] FIG. 4 is a cross-sectional image of an insulating material according to one embodiment of the present disclosure, taken with a scanning electron microscope (SEM).

[0016] FIG. 5 is a graph showing the relationship between the weight part of an aromatic polyol and the average diameter of a urethane according to one embodiment of the present disclosure.

[0017] FIG. 6 is a graph showing the relationship between the weight part of PFPE and the dispersion of the average diameter of urethane according to one embodiment of the present disclosure.

[0018] FIG. 7 is a flowchart relating to a method for manufacturing urethane according to one embodiment of the present disclosure.

[0019] In the following description, the attached drawings are referenced, and specific examples of implementation are illustrated within the drawings. Additionally, other examples may be used and structural modifications may be made without departing from the scope of the various examples.

[0020] The various embodiments of this document and the terms used therein are not intended to limit the technical features described in this document to specific embodiments, and should be understood to include various modifications, equivalents, or substitutions of said embodiments.

[0021] The singular form of the noun corresponding to an item may include one or plural items, unless the relevant context clearly indicates otherwise.

[0022] In this document, each of the phrases such as "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "at least one of A, B, or C" may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0023] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish a component from another corresponding component and do not limit the components in other aspects (e.g., importance or order).

[0024] Where any (e.g., 1st) component is referred to as "coupled" or "connected" to another (e.g., 2nd) component, with or without the terms "functionally" or "communicationly," it means that the component may be connected to the other component directly (e.g., via a wire), wirelessly, or through a third component.

[0025] Terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this document, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0026] When it is said that a component is "connected," "combined," "supported," or "in contact" with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0027] When it is said that a component is located "on" another component, this includes not only cases where one component is in contact with the other, but also cases where another component exists between the two components.

[0028] The term "and / or" includes a combination of multiple related described components or any of the multiple related described components.

[0029] The effects obtainable from the exemplary embodiments of the present disclosure can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure belong from the description below. That is, unintended effects resulting from the implementation of the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0030] The operating principle and embodiments of the present invention will be described below with reference to the attached drawings.

[0031] The refrigerator (1) described below is to be understood as being illustrative for the purpose of facilitating understanding of the present disclosure and may be implemented with various modifications. Additionally, some of the attached drawings may not be drawn to actual scale and the dimensions of some components may be exaggerated to facilitate understanding of the present disclosure.

[0032] FIG. 1 is a perspective view illustrating the exterior of a refrigerator according to one embodiment of the present disclosure.

[0033] FIG. 2 is a perspective view with the door of a refrigerator opened, according to one embodiment of the present disclosure.

[0034] FIG. 3 is a cross-sectional view of a refrigerator according to one embodiment of the present disclosure.

[0035] Referring to FIGS. 1 to 3, the refrigerator (1) may include a main body (10), a storage room (21, 22, 23) formed inside the main body (10), a door (31, 32, 33, 34) for opening and closing the storage room (21, 22, 23), and a cold air supply device (50) for supplying cold air to the storage room (21, 22, 23).

[0036] According to one embodiment, the main body (10) may include an inner layer (11) forming storage chambers (21, 22, 23), an outer layer (12) coupled to the outside of the inner layer (11) to form an outer layer, and an insulating material (100) provided between the inner layer (11) and the outer layer (12) to insulate the storage chambers (21, 22, 23). The insulating material (100) may be composed of, for example, urethane. The detailed composition (e.g., composition ratio) of the insulating material (100) will be described with reference to FIG. 4 and below.

[0037] According to one embodiment, a machine room (13) in which some components of a cold air supply device (50) are arranged (or accommodated) may be provided in the lower part of the main body (10). For example, a compressor (53) of the cold air supply device (50) may be arranged in the machine room (13).

[0038] According to one embodiment, the storage rooms (21, 22, 23) may be divided into multiple sections by a horizontal partition (15) and a vertical partition (16). The storage rooms (21, 22, 23) may be divided into an upper storage room (21) and lower storage rooms (22, 23) by the horizontal partition (15). The lower storage rooms (22, 23) may be divided into a left lower storage room (22) and a right lower storage room (23) by the vertical partition (16). The upper storage room (21) may be used as a refrigerator, and the lower storage rooms (22, 23) may be used as a freezer. However, such division and use of the storage rooms (21, 22, 23) are merely examples, and the present disclosure is not limited thereto. Unlike what is shown in the drawing, the refrigerator (1) may be an SBS (side by side) type in which the storage compartment is divided into left and right by a single vertical partition, an FDR (french door refrigerator) type in which the storage compartment is divided into an upper refrigerator compartment and a lower refrigerator compartment by a single horizontal partition, or a 1-door type having one storage compartment and one door.

[0039] According to one embodiment, a shelf (26) for placing food and a storage container (27) for storing food may be provided inside the storage room (21, 22, 23).

[0040] According to one embodiment, the doors (31, 32, 33, 34) may be rotatably connected to the main body (10). The doors (31, 32, 33, 34) may include a first door (31) located in the upper left, a second door (32) located in the upper right, a third door (33) located in the lower left, and a fourth door (44) located in the lower right. The first door (31) and the second door (32) may be referred to as a pair of upper doors (31, 32), and the third door (33) and the fourth door (34) may be referred to as a pair of lower doors (33, 34).

[0041] According to one embodiment, the upper storage room (21) can be opened and closed by a pair of upper doors (31, 32). The upper doors (31, 32) can be rotatably coupled to the main body (10). According to one embodiment, each of the lower storage rooms (22, 23) can be opened and closed by a pair of lower doors (33, 34). The lower doors (33, 34) can be rotatably coupled to the main body (10).

[0042] According to one embodiment, the door (31, 32, 33, 34) may include a door basket (39, 40) having a door storage space for storing food. A gasket (37) that adheres to the front of the main body (10) to seal the storage chamber (21, 22, 23) may be provided on the back of the door (31, 32, 33, 34). The gasket (37) may be positioned along the back edge of the door (31, 32, 33, 34).

[0043] According to one embodiment, at least one of the doors (31, 32, 33, 34) may be configured as a double door having an inner door (35) and an outer door (36). For example, the upper left door (31) may include an inner door (35) and an outer door (36).

[0044] According to one embodiment, an outer door (36) may be provided to open and close the door interior space of an inner door (35). A gasket may be provided on the back of the outer door (36) to seal the door interior space. The gasket may be positioned around the door interior space and may be in close contact with the front of the inner door (35).

[0045] According to one embodiment, when the outer door (36) is opened, access to the door interior space of the inner door (35) is possible. The outer door (36) may be rotatably connected to the inner door (35) via a hinge (not shown). The outer door (36) may rotate in the same direction as the inner door (35). The outer door (36) may have a size corresponding to the size of the inner door (35). The outer door (36) may cover the entire area of ​​the inner door (35).

[0046] According to one embodiment, a decorative panel (not shown) can be detachably attached to the front of the outer door (36).

[0047] According to one embodiment, 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 a hinge and various electrical components placed 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 to input various commands for the operation of the refrigerator (1).

[0048] According to one embodiment, the cold air supply device (50) may be configured to generate cold air using a cooling circulation cycle that compresses, condenses, expands, and evaporates a refrigerant, and to supply the generated cold air to storage rooms (21, 22, 23). For example, the cold air supply device (50) may maintain the temperature of the storage rooms (21, 22, 23) within a specified range by using the circulation of the refrigerant through the cooling circulation cycle.

[0049] According to one embodiment, the cold air supply device (50) can cool the air in the storage room (21, 22, 23) by utilizing the phenomenon in which a refrigerant in a liquid state undergoes a phase change to a gaseous state and absorbs thermal energy from the surrounding air. However, the present disclosure is not limited to the cold air supply device (50) including a cooling circulation cycle. For example, the cold air supply device (50) may include a Peltier element utilizing the Peltier effect or a magnetic cooling material utilizing the magneto-caloric effect.

[0050] According to one embodiment, the cold supply device (50) may include a compressor (53) that compresses a refrigerant in a gaseous state, a condenser (not shown) that converts the compressed gaseous refrigerant into a liquid state, an expansion device (not shown) that reduces the pressure of the liquid refrigerant, and an evaporator (54) that converts the reduced liquid refrigerant into a gaseous state.

[0051] According to one embodiment, the cold air supply device (50) may further include a blower (55) configured to circulate cold air supplied to the storage rooms (21, 22, 23). The blower (55) may be positioned on one side (e.g., the rear) of the storage rooms (21, 22, 23). The blower (55) may be provided in multiple units and distributed to each of the upper storage room (21) and the lower storage rooms (22, 23).

[0052] According to one embodiment, the evaporator (54) may be positioned on one side (e.g., the rear) of the storage chambers (21, 22, 23). For example, the evaporator (54) may be installed to be fixed to one side of the inner chamber (11). The evaporator (54) may be provided in multiple units and divided and positioned in the upper storage chamber (21) and the lower storage chambers (22, 23), respectively.

[0053] According to one embodiment, the evaporator (54) can operate to lower the temperature of the surrounding air by evaporating the refrigerant through heat exchange with the surrounding air. Water vapor contained in the surrounding air can condense during the heat exchange process and form on the surface of the evaporator (54).

[0054] According to one embodiment, the refrigerator (1) may include a drain pan (14) for collecting condensation formed on the surface of the evaporator (54). The drain pan (14) may be integrally provided in the inner chamber (11) of the main body (10). The drain pan (14) may be provided in a part (e.g., the lower part) of the inner chamber (11) where the evaporator (54) is positioned to collect condensation.

[0055] According to one embodiment, the refrigerator (1) may include a drain hose configured to discharge condensate collected in a drain pan (14) to the outside or to guide it to a water receiving container (17) provided in the machine room (13). Condensate collected in the drain pan (14) may be collected in the water receiving container (17) through the drain hose, and the condensate collected in the water receiving container (17) may be evaporated by heat generated in a compressor (53) or a condenser. Condensate collected in the water receiving container (17) may also be discharged to the outside through a separate drain hose (not shown) connected to the water receiving container (17).

[0056] FIG. 4 is a cross-sectional image of an insulating material according to one embodiment of the present disclosure, taken with a scanning electron microscope (SEM).

[0057] Referring to FIG. 4, an insulating material (100) (hereinafter referred to as urethane) according to one embodiment may include a plurality of open cells (101), a plurality of closed cells (102), and cell walls (103). A closed cell (102) refers to a closed cavity containing an internal gas generated during urethane foaming. The internal gas may include, for example, CP (Cyclopentane), air, HFO (hydrofluoro-olefin), HFC (hydrofluorocarbon), or carbon dioxide (CO2). An open cell (101) refers to an open cavity that does not form a closed cell (102) and is connected to the external atmosphere. A cell wall (103) refers to a structure provided between a closed cell (102) and an open cell (101), or between a plurality of closed cells (102), and connects a closed cell (102) and an open cell (101), or a plurality of closed cells (102). Additionally, the strut (104) refers to a point where three or more closed cells (102) or open cells (101) meet.

[0058] The thermal conductivity of urethane (λurethane), which determines the thermal insulation performance of urethane, can be calculated using the following equation (1).

[0059] Equation (1): λurethane = λgas + λsolid + λradiation + λconvection

[0060] The thermal conductivity of the urethane (λurethane) can be calculated as the sum of the thermal conductivity of the internal gas contained in the sealed cell (102) (λgas), the thermal conductivity of the cell wall (103) (λsolid), the thermal conductivity due to radiant energy generated throughout the cell wall (103) and the internal gas (λradiation), and the convective thermal conductivity (λconvection) generated by the circulation of the internal gas. However, since convective thermal conductivity is generally known to have almost no effect within the urethane, it is not considered when calculating the thermal conductivity of the urethane (λurethane) in the present invention.

[0061] In order to lower the thermal conductivity of the urethane (λurethane), the thermal conductivity of the internal gas (λgas), the thermal conductivity of the cell wall (103) (λsolid), or the thermal conductivity due to radiant energy (λradiation) must be lowered. In the present invention, the thermal conductivity due to radiant energy (λradiation) is lowered by miniaturizing the diameter of the cell.

[0062] The thermal conductivity (λradiation) due to the above radiation energy can be expressed by the following equation (2).

[0063] Equation (2):

[0064]

[0065] In the above equation (2), K can be expressed by the following equation (3).

[0066] Equation (3):

[0067]

[0068] In the above equation (3), fs can be expressed as the following equation (4).

[0069] Equation (4):

[0070] In the above equations (2) and (3), σ represents the Stefan-Boltzmann constant, T represents the temperature, K represents the absorption coefficient, and f s represents the strut fraction, and ρ f represents the density of the foamed urethane, and ρ s represents the density of the solid urethane in an unfoamed state, d represents the average diameter of the closed cell (102), Kw represents the absorption coefficient of the cell wall (103), and t represents the average thickness of the cell wall (103).

[0071] Meanwhile, the above σ (Stefan-Boltzmann constant) is 5.6704 * 10⁻⁸ W / m 2 ·K 4 Substitute into, substitute the above temperature (T) as 293 K, and the above ρs The density of unfoamed solid urethane is 1250 kg / m³ 3 Substitute as, and the above K w (The absorption coefficient of the cell wall (103)) is calculated by substituting 60000 1 / m.

[0072] In order to lower the thermal conductivity (λradiation) due to radiant energy, the density (ρf) of the foamed urethane must be increased, and the average diameter (d) of the urethane (or the diameter of the open cell (101), the diameter of the closed cell (102)) must be reduced. In addition, the thermal conductivity (λradiation) due to radiant energy is calculated to be almost constant regardless of the increase or decrease in the average thickness (t) of the cell wall (103).

[0073] According to one embodiment, the urethane may have a thermal conductivity of 19.3 to 19.4 mW / m·K.

[0074] According to one embodiment, the average diameter (d) of the urethane may be 150 to 165 μm.

[0075] Hereinafter, the composition and / or manufacturing method of urethane to satisfy the thermal conductivity and diameter (d) of the urethane as described above will be explained.

[0076] The urethane according to one embodiment and the urethane according to a comparative example constituting the insulation material may have the composition ratios shown in the table below.

[0077] Urethane Components Comparative Example Example Polyol System Aromatic Polyol 30 ~ 40 40 ~ 60 Aliphatic Polyol 60 ~ 70 40 ~ 60 Isocyanate 110 ~ 120 110 ~ 120 Foaming Agent 15 ~ 25 15 ~ 25 Foam Stabilizer 1 ~ 5 1 ~ 5 Catalyst 0.5 ~ 3.5 0.5 ~ 3.5 PFPE 0 0.2 ~ 0.4

[0078] According to one embodiment, the urethane may include a polyol system, an isocyanate, a foaming agent, a foam stabilizer, a catalyst, or PFPE (Perfluoro Polyether).

[0079] According to one embodiment, the polyol system of the urethane may comprise an aromatic polyol in the range of 40 to 60 parts by weight and an aliphatic polyol in the range of 40 to 60 parts by weight, based on 100 parts by weight of the polyol system. The aromatic polyol may comprise an aromatic structure such as a benzene ring. The aliphatic polyol may comprise a linear or branched hydrocarbon structure.

[0080] Urethane can be formed as a result of the chemical reaction between a polyol (e.g., a polyol system) and an isocyanate, as shown in Reaction Scheme 1 below.

[0081] Reaction Equation 1:

[0082]

[0083] Urethane can be produced, for example, by the chemical bonding of a hydroxyl group (-OH) and an isocyanate group (-NCO) (urethane bond). In this case, in addition to the chemical bonding of the hydroxyl group (-OH) and the isocyanate group (-NCO), aggregation may occur between the aromatic rings (e.g., benzene rings) of the polyol and the isocyanate, respectively. For example, the aromatic rings of the polyol and the isocyanate, respectively, may aggregate with each other through double bonds, specifically π bonds (or electric dipole moments).

[0084] Referring to [Table 1], when comparing the urethane according to one embodiment of the present disclosure with the urethane according to a comparative example, it can be seen that the content of aromatic polyol in the urethane in one embodiment is increased compared to the comparative example. In this case, as described above, the diameter (d) of the urethane (e.g., closed cell or open cell (101)) may be reduced due to aggregation between the polyol and the isocyanate. Additionally, aggregation between the polyol and the isocyanate may hinder aggregation between the urethanes.

[0085] In addition, when a blowing agent is added to create internal pores and H2O is used as a co-blowing agent to aid in foaming, CO2 and amine can be formed as shown in reaction equation 2 below.

[0086] Reaction Equation 2:

[0087]

[0088] Meanwhile, the amine generated in the above reaction scheme 2 is required for the subsequent reaction, the urea and biuret reaction. In the above urea and biuret reaction, urea, biuret, etc. act as intermediate reaction groups to strengthen the physical bonding strength of the urethane.

[0089] According to one embodiment, the isocyanate of the urethane may comprise 110 to 120 parts by weight based on 100 parts by weight of the polyol system. The isocyanate may be, for example, methylene diphenyl diisocyanate (MDI) or toluene diisocyanate (TDI).

[0090] According to one embodiment, the blowing agent of the urethane serves to form internal cells of the urethane. In one embodiment, the blowing agent may comprise 15 to 25 parts by weight based on 100 parts by weight of the polyol system. The blowing agent may comprise, for example, at least one of CP (Cyclopentane), HFO (hydrofluoro-olefin), and HFC (hydrofluorocarbon).

[0091] According to one embodiment, the foaming agent of the urethane serves to maintain the urethane cells formed through a surfactant effect. In one embodiment, the foaming agent may comprise 1 to 5 parts by weight based on 100 parts by weight of the polyol system.

[0092] According to one embodiment, the catalyst for the urethane plays a role in accelerating or delaying the chemical reaction rate during the urethane production process. In one embodiment, the catalyst may comprise 0.5 to 3.5 parts by weight based on 100 parts by weight of the polyol system. The catalyst may include a foaming catalyst, a resinification catalyst, and a trimerization catalyst. For example, the catalyst may be at least one of triethylamine (TEA), triethylenediamine (TEDA), pentamethylethylenediethylene triamine (PMDETA), dimethylcyclohexylamine (DMCHA), and tetramethyln-hexyldiamine (TMHDA).

[0093] According to one embodiment, the PFPE in the urethane can serve to reduce or homogenize the diameter (or size) of the urethane cells. In one embodiment, the PFPE in the urethane may be included in an amount of 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system. The PFPE may be named a cell homogenizing agent.

[0094] The diameter (d) of the above urethane can be determined by the following equation (5). The above equation (5) may correspond to the Young-Laplace law.

[0095] Equation (5): ΔP = 4ρ / d

[0096] In the above equation (5), ΔP represents the pressure difference between the outside and inside of the urethane (or cell), ρ represents the surface tension of the urethane, and d represents the average diameter of the urethane.

[0097] In light of the above equation (5), in order to reduce the average diameter (d) of the urethane, the surface tension (ρ) of the urethane must be lowered, or the pressure difference (ΔP) between the outside and inside of the urethane must be increased.

[0098] In one embodiment, the surface tension (ρ) of the urethane can be lowered by adding PFPE to the urethane. For example, as the amount of PFPE added increases, the surface tension (ρ) of the urethane can be gradually lowered by the PFPE surrounding the urethane (or surface), and micelles can be formed when the amount of PFPE added reaches a critical micelle concentration (CMC).

[0099] In one embodiment, the boiling point of PFPE may be 40 to 80 degrees. When urethane is produced according to the reaction equation (1) described above, the temperature of the urethane may rise up to 150 degrees due to the exothermic reaction. If the boiling point of the added cell homogenizer is 150 degrees or higher, it does not vaporize during urethane production and cannot be uniformly distributed in the urethane. In addition, if the boiling point of the added cell homogenizer is below room temperature, problems such as gas loss may occur during storage or transportation of the cell homogenizer. Considering these points, PFPE having a boiling point of 40 to 80 degrees may be selected as the cell homogenizer.

[0100] FIG. 5 is a graph showing the relationship between the weight part of an aromatic polyol and the average diameter of a urethane according to one embodiment of the present disclosure.

[0101] The X-axis of Fig. 5 represents the weight portion of the aromatic polyol in the polyol system based on 100 weight parts of the polyol system. The Y-axis of Fig. 5 represents the average diameter (um) of the urethane.

[0102] Referring to Fig. 5, it can be seen that the average diameter of the urethane gradually decreases in a certain range as the weight portion of the aromatic polyol in the polyol system increases. This can also be confirmed in the table below.

[0103] Specimen Name 12345678 Aromatic Polyo Content 3035404550556070 Specimen Mean 204.6186.4177.8163.8159.0156.5155.0155.2 Dispersion 119.7120.0114.3115.1115.2113.9114.4110.4 Standard Deviation 48.3648.3248.4647.1044.6740.8740.9140.66

[0104] Table 2 shows the average diameter of specimens with different weight parts of aromatic polyol based on 100 weight parts of a polyol system, as well as the dispersion and standard deviation thereof.

[0105] Referring to Table 2, when the weight part of aromatic polyol is 30 (Specimen 1), the average diameter of the urethane is 204.6 µm; when the weight part of aromatic polyol is 35 (Specimen 2), the average diameter of the urethane is 186.4 µm; when the weight part of aromatic polyol is 40 (Specimen 3), the average diameter of the urethane is 177.8 µm; when the weight part of aromatic polyol is 45 (Specimen 4), the average diameter of the urethane is 163.8 µm; when the weight part of aromatic polyol is 50 (Specimen 5), the average diameter of the urethane is 159.0 µm; when the weight part of aromatic polyol is 55 (Specimen 6), the average diameter of the urethane is 156.5 µm; and when the weight part of aromatic polyol is 60 (Specimen 7), the average diameter of the urethane is 155.0 µm. It can be confirmed that the average diameter of the urethane is 155.2 µm when the weight part of the aromatic polyol is 70 (Specimen 8).

[0106] As a result, it can be observed that the average diameter of the urethane gradually decreases as the weight portion of the aromatic polyol increases. The average diameter of the urethane gradually decreases as the weight portion of the aromatic polyol increases, but it can be observed that the rate of change is negligible after the weight portion of the aromatic polyol is 60. Based on this, the weight portion of the aromatic polyol can be set within the range of 40 to 60. In addition, the thermal conductivity of the urethane at this time can be 19.5 to 19.6 mW / m·K.

[0107] However, when the weight part of aromatic polyol is 30 (Specimen 1), the dispersion of the average diameter of the urethane is 119.7; when the weight part of aromatic polyol is 35 (Specimen 2), the dispersion of the average diameter of the urethane is 120.0; when the weight part of aromatic polyol is 40 (Specimen 3), the dispersion of the average diameter of the urethane is 114.3; when the weight part of aromatic polyol is 45 (Specimen 4), the dispersion of the average diameter of the urethane is 115.1; when the weight part of aromatic polyol is 50 (Specimen 5), the dispersion of the average diameter of the urethane is 115.2; when the weight part of aromatic polyol is 55 (Specimen 6), the dispersion of the average diameter of the urethane is 113.9; and when the weight part of aromatic polyol is 60 (Specimen 7), the dispersion of the average diameter of the urethane is It can be confirmed that the average diameter of the urethane is 110.4 when the weight part of the aromatic polyol is 70 (specimen 8), and the dispersion of the average diameter of the urethane is 111.4.

[0108] Consequently, it was confirmed that while the average urethane diameter gradually decreases as the weight portion of aromatic polyol increases, the dispersion and / or standard deviation regarding the average urethane diameter are not uniform. Therefore, a method for homogenizing the cells was required.

[0109] FIG. 6 is a graph showing the relationship between the weight part of PFPE and the dispersion of the average diameter of urethane according to one embodiment of the present disclosure.

[0110] The X-axis of Fig. 6 represents the weight of PFPE based on 100 parts by weight of the polyol system. The Y-axis of Fig. 6 represents the dispersion regarding the average diameter of the urethane.

[0111] Referring to Fig. 6, it can be seen that the dispersion regarding the average diameter of the urethane gradually decreases in a certain range as the weight part of PFPE increases. This can also be confirmed in the table below.

[0112] Specimen Name 12345 Cells Homogenizer Content 0.20.31 Specimen Mean 156.5 158.0 156.5 156.0 158.5 Dispersion 113.9 83.0 74.4 73.7 70.7 Standard Deviation 40.8 738.6 938.7 834.7 231.77

[0113] Table 3 shows the test results based on 40 to 60 parts by weight of aromatic polyol based on 100 parts by weight of polyol system.

[0114] Table 3 shows the average diameter of specimens with different weight parts of PFPE (or cell homogenizer) based on 100 weight parts of a polyol system, as well as the dispersion and standard deviation thereof.

[0115] Referring to Table 3, it can be seen that when the weight part of PFPE is 0 (Specimen 1), the dispersion of the average diameter of the urethane is 113.9, when the weight part of PFPE is 0.2 (Specimen 2), the dispersion of the average diameter of the urethane is 83.9, when the weight part of PFPE is 0.3 (Specimen 3), the dispersion of the average diameter of the urethane is 74.4, when the weight part of PFPE is 1 (Specimen 4), the dispersion of the average diameter of the urethane is 73.7, and when the weight part of PFPE is 3 (Specimen 5), the dispersion of the average diameter of the urethane is 70.7.

[0116] As a result, it can be observed that the dispersion regarding the average diameter of the urethane gradually decreases as the weight part of PFPE increases. It can be observed that the dispersion regarding the average diameter of the urethane gradually decreases as the weight part of PFPE increases, and then the rate of change becomes negligible based on the weight part of PFPE being approximately 0.3. Based on this, the weight part of PFPE can be set within the range of 0.2 to 0.4. At this time, the thermal conductivity of the urethane can be 19.3 to 19.4 mW / m·K.

[0117] FIG. 7 is a flowchart relating to a method for manufacturing urethane according to one embodiment of the present disclosure.

[0118] The processes 710, 720, and 730 described below, illustrated in this drawing, may be performed individually or collectively, and the order of the processes illustrated in this drawing should not be understood as constraining the order of each process.

[0119] Referring to FIG. 7, a method for manufacturing urethane according to one embodiment may form a urethane polymer by reacting an isocyanate with a polyol system comprising an aromatic polyol and an aliphatic polyol in process 710. When forming the urethane polymer, the average diameter of the urethane may be reduced by aggregation between the aromatic rings of the aromatic polyol and the isocyanate. For example, the aromatic polyol may be included in an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system.

[0120] According to one embodiment, a method for manufacturing urethane may add a blowing agent, a foam stabilizer, and / or a catalyst in process 720. When forming a urethane polymer, cells may be formed by the blowing agent, the cells formed by the foam stabilizer are maintained, and the reaction rate is controlled by the catalyst.

[0121] According to one embodiment, in the method for manufacturing urethane, PFPE may be added in process 730. When forming the urethane polymer, the average diameter of the urethane may be reduced as the surface tension of the cells is reduced by PFPE, and the size of the cells formed may become uniform.

[0122] The urethane produced by the above processes may have a thermal conductivity of 19.3 to 19.4 mW / m·K. In addition, the urethane produced by the above processes may have an average diameter of 150 to 165 μm.

[0123] According to one embodiment of the present disclosure, a rigid urethane with improved thermal insulation performance and a refrigerator including the same can be provided.

[0124] According to one embodiment, the urethane comprises 40 to 60 parts by weight of an aromatic polyol based on 100 parts by weight of the polyol system, so that during the urethane chemical reaction, the average diameter of the urethane can be reduced by the aggregation of aromatic rings of the aromatic polyol and the isocyanate along with urethane bonding. Accordingly, the thermal conductivity of the resulting urethane can be lowered.

[0125] According to one embodiment, the urethane comprises 0.2 to 0.4 parts by weight of PFPE based on 100 parts by weight of the polyol system, thereby lowering the surface tension of the urethane, which can reduce the average diameter of the urethane and also reduce the dispersion of the average diameter of the urethane. Accordingly, the thermal conductivity of the produced urethane can be lowered.

[0126] According to one embodiment of the present disclosure, a refrigerator (1) may include an inner layer (11) forming storage compartments (21, 22, 23), an outer layer (12) coupled to the outside of the inner layer (11), and an insulating material (100) provided between the inner layer (11) and the outer layer (12). The insulating material (100) may include a polyol system comprising an aliphatic polyol and an aromatic polyol, an isocyanate, and PFPE (Perfluoro Polyether). The aliphatic polyol may have 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The aromatic polyol may have 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The PFPE may have 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system.

[0127] According to one embodiment, the insulating material (100) may include a plurality of open cells (101) connected to the outside atmosphere and a plurality of closed cells (102) that contain internal gas.

[0128] According to one embodiment, the average diameter of the closed cell (102) and / or open cell (101) may be 150 to 165 μm.

[0129] According to one embodiment, the dispersion regarding the average diameter of the closed cell (102) and / or open cell (101) may be 75 to 85.

[0130] According to one embodiment, the thermal conductivity of the insulation material (100) may be 19.3 to 19.4 mW / m·K.

[0131] According to one embodiment, the boiling point of the PFPE may be 40 to 80 degrees.

[0132] According to one embodiment, the insulating material (100) may further include a foaming agent, a foam stabilizer, and a catalyst. Based on 100 parts by weight of the polyol system, the foaming agent may have 15 to 20 parts by weight, the foam stabilizer may have 1 to 5 parts by weight, and the catalyst may have 0.5 to 3.5 parts by weight.

[0133] According to one embodiment, the blowing agent may be at least one of CP (Cyclopentane), HFO (hydrofluoro-olefin), and HFC (hydrofluorocarbon).

[0134] According to one embodiment, the internal gas may include CP (Cyclopentane), air, HFO (hydrofluoro-olefin), HFC (hydrofluorocarbon), or carbon dioxide (CO2).

[0135] According to one embodiment of the present disclosure, the urethane constituting the insulation material (100) for a refrigerator (1) may include a polyol system comprising an aliphatic polyol and an aromatic polyol, an isocyanate, and PFPE. The aliphatic polyol may have 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The aromatic polyol may have 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The PFPE may have 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system.

[0136] According to one embodiment, the insulating material (100) may include a plurality of open cells (101) connected to the outside atmosphere and a plurality of closed cells (102) containing internal gas. The average diameter of the closed cells (102) and / or open cells (101) may be 150 to 165 μm.

[0137] According to one embodiment, the dispersion regarding the average diameter of the closed cell (102) and / or open cell (101) may be 75 to 85.

[0138] According to one embodiment, the thermal conductivity of the urethane may be 19.3 to 19.4 mW / m·K.

[0139] According to one embodiment, the boiling point of the PFPE may be 40 to 80 degrees.

[0140] According to one embodiment, the urethane may further comprise a blowing agent, a foam stabilizer, and a catalyst. Based on 100 parts by weight of the polyol system, the blowing agent may be 15 to 20 parts by weight, the foam stabilizer may be 1 to 5 parts by weight, and the catalyst may be 0.5 to 3.5 parts by weight.

[0141] A method for manufacturing urethane according to one embodiment of the present disclosure may include a urethane polymer forming process (710) in which a polyol system and an isocyanate are reacted, a cell forming process (720) in which a foaming agent, a foaming agent and / or a catalyst are added for cell formation, and a cell homogenization process (730) in which PFPE is added to reduce the average diameter and dispersion of the cells.

[0142] According to one embodiment, the polyol system may include an aliphatic polyol and an aromatic polyol. The aliphatic polyol may have an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The aromatic polyol may have an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system. The PFPE may have an amount of 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system.

[0143] According to one embodiment, the average diameter of the cell may be 150 to 165 µm.

[0144] According to one embodiment, the thermal conductivity of the urethane may be 19.3 to 19.4 mW / m·K.

[0145] According to one embodiment, the boiling point of the PFPE may be 40 to 80 degrees.

Claims

1. In the refrigerator (1), An inner layer (11) forming storage chambers (21, 22, 23); An external (12) coupled to the outside of the internal (11) above; and The above inner surface (11) includes an insulating material (100) provided between the above outer surface (12), and The above insulation material (100) is, Polyol system comprising aliphatic polyols and aromatic polyols; isocyanate; and Contains PFPE (Perfluoro Polyether), and The above aliphatic polyol has an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system, The above aromatic oliol has an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system, The refrigerator having 0.2 to 0.4 parts by weight of the above PFPE based on 100 parts by weight of the above polyol system.

2. In Paragraph 1, The above insulation material (100) is, A plurality of open cells (101) connected to the external atmosphere; and A refrigerator comprising a plurality of sealed cells (102) that accommodate internal gas.

3. In Paragraph 2, A refrigerator in which the average diameter of the above-mentioned closed cell (102) and / or open cell (101) is 150 to 165 μm.

4. In Paragraph 2 or 3, A refrigerator in which the average diameter of the above-mentioned closed cell (102) and / or open cell (101) is 75 to 85.

5. In any one of paragraphs 1 through 4, A refrigerator in which the thermal conductivity of the above-mentioned insulating material (100) is 19.3 to 19.4 mW / m·K.

6. In any one of paragraphs 1 through 5, A refrigerator in which the boiling point of the above PFPE is 40 to 80 degrees.

7. In the urethane constituting the insulation material (100) for the refrigerator (1), Polyol system comprising aliphatic polyols and aromatic polyols; isocyanate; and Contains PFPE, The above aliphatic polyol has an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system, The above aromatic oliol has an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system, The above PFPE is a urethane having 0.2 to 0.4 parts by weight based on 100 parts by weight of the polyol system.

8. In Paragraph 7, A plurality of open cells (101) connected to the external atmosphere; and It includes a plurality of sealed cells (102) that accommodate internal gas, and The average diameter of the above closed cells and / or open cells is 150 to 165 μm, and The dispersion regarding the average diameter of the above-mentioned closed cell (102) and / or open cell (101) is 75 to 85, urethane.

9. In Paragraph 7 or 8, Urethane with a thermal conductivity of 19.3 to 19.4 mW / m·K.

10. In any one of paragraphs 7 through 9, The above PFPE is a urethane having a boiling point of 40 to 80 degrees.

11. In a method for manufacturing urethane, A urethane polymer formation process (710) that reacts a polyol system with an isocyanate; A cell formation process (720) for adding a foaming agent, a foaming agent and / or a catalyst for cell formation; and A method comprising a cell homogenization process (730) of adding PFPE to reduce the average diameter and dispersion of the cells.

12. In Paragraph 11, The above polyol system includes an aliphatic polyol and an aromatic polyol, and The above aliphatic polyol has an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system, The above aromatic oliol has an amount of 40 to 60 parts by weight based on 100 parts by weight of the polyol system, A method having 0.2 to 0.4 parts by weight of the above PFPE based on 100 parts by weight of the above polyol system.

13. In Paragraph 11 or 12, A method in which the average diameter of the cell is 150 to 165 µm.

14. In any one of paragraphs 11 through 13, A method in which the thermal conductivity of the above urethane is 19.3 to 19.4 mW / m·K.

15. In any one of paragraphs 11 through 13, A method in which the boiling point of the above PFPE is 40 to 80 degrees.

Images