KR19990067747A - refrigerator - Google Patents

Abstract

The present invention relates to a refrigerator having a thermal insulation box filled with a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water, wherein CFC and HCFC are not used as a blowing agent, and a cyclopentane and water mixture system is used as a substitute and high strength and urethane. In order to enable energy saving by reducing the amount of filling and the amount of heat leakage, an insulating box formed by filling a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water is provided in the space formed between the outer box and the inner box of the refrigerator. In one refrigerator, a material having a total skin density of 34 to 37 kg / m 3, a compressive strength of 0.1 Mpa or more, and a bending strength of 0.4 Mpa or more, using at least 500 mm or more from the inlet of the rigid polyurethane foam. The insulation box filled with 30-35 g / L of insulation It was in a configuration.

With such a configuration, by foaming and filling a urethane material having low density, high flowability and high strength characteristics, it is possible to reduce the cost and weight, and to provide excellent compressive strength and dimensional stability and to reduce heat leakage. Energy saving is possible.

Description

Refrigerator {refrigerator}

The present invention relates to a refrigerator having a thermal insulation box filled with a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water.

Conventionally, the heat insulation box of a refrigerator uses the heat insulating material which fills the rigid polyurethane foam which has an independent bubble in the space of an outer box and an inner box. Hard polyurethane foam is obtained by making a polyol component and an isocyanate component react in presence of a foaming agent, a catalyst, and a foam stabilizer. Conventional blowing agents are trichloromonofluoromethanes of refractory chlorofluorocarbons (CFCs) having low gas thermal conductivity (for example, Japanese Patent Application Laid-Open No. 59-84913) are used for heat insulation of refrigerators. However, when released into the atmosphere, the ozone layer in the strata is destroyed, or the surface temperature rises due to the greenhouse effect, thereby selecting alternatives. Currently, 1, 1-dichloro-1-monofluoroethane, which is one kind of hydrochlorofluorocarbon (HCFC) as an alternative foaming agent (Japanese Patent Laid-Open Publication No. 3-258823, Japanese Patent Laid-Open Publication No. 7 as a known example) -25978) is used as insulation for refrigerators. However, since these alternative foaming agents are not zero in the ozone layer destruction coefficient, they are expected to become fully regulated in 2003. On the other hand, non-foam-based blowing agents having a zero ozone depletion coefficient of 0 are actively replaced by hydrocarbon-based compounds (for example, Japanese Patent Application Laid-Open No. HEI 3-152160), and thus cyclopentane blowing agents in Japan. Has been used in the insulation of refrigerators. However, cyclopentane has a problem that the thermal insulation performance is significantly lowered because the thermal conductivity of the gas is higher than that of the conventional blowing agent.

In recent years, as the demand for energy for rigid polyurethane foam materials of cyclopentane prescription has increased, the balance of energy supply and demand has been secured, and the urethane consumption has been reduced from the standpoint of improving the thermal insulation performance by saving energy and protecting the global environment as a response to global warming problems. Increasing the importance of, and from that point of view, the overall expansion to the insulating medium of the refrigerator using a cyclopentane blowing agent is required to improve the performance.

In the rigid polyurethane foam material, polyols and isocyanates, which are the main raw materials, control chemical structures, foaming agents that form bubbles, water, and foam stabilizers that control interfacial phenomena, control of physical structures, and catalysts for controlling reactivity. do. The reaction is started at the time of mixing the polyol and the isocyanate, and a polyurethane foam in which the independent bubbles of the blowing agent are dispersed is formed in the polyurethane resin. Polyurethane foams require strength in particular with thermal insulation. These physical properties are considered to be determined by the physical structure of the polyurethane foam, such as the cell structure, the size of the polyurethane resin chemical structure, density, the resin skeleton surrounding the bubble. The chemical structure of the polyurethane resin depends on the chemical structure of the polyols and isocyanates as raw materials, the amount of blowing agent, the amount of water, and the reactivity controlled by the catalyst. The physical structure of polyurethane foam depends not only on the chemical structure and reactivity of raw materials, but also on the phenomena such as the generation and growth of bubbles controlled by foam stabilizers. Particularly, the compatibility, reactivity, foaming process of each raw material The fluidity of the reaction solution at For this reason, in order to improve polyurethane foam performance, the chemical structure and composition of each raw material must be optimized.

However, the insulating material for short-term boxes of the cyclopentane prescription refrigerator is significantly lower in thermal insulation performance than the conventional CFC and HCFC foaming agents, and has high density and poor fluidity. There is a problem that securing this and strength is not sufficient. In addition, urethane foam is difficult to flow inside the wall due to the narrowing of the space in the cabinet wall and the increase of the number of boxes or driving wirings in the cabinet wall due to the requirement of saving the space of the refrigerator. . Because of this, it is difficult for the foam to stretch uniformly, and the ceiling, bottom, and back of the refrigerator. Since the total density of the skin layer and the core layer density in the handle part and the hinge part are greatly different, it is difficult to form a uniform foam, and it is easy to generate bubbles (double skin), voids (voids), etc. High performance in pentane prescription is required. In order to cope with the problem, it is necessary to develop a new urethane material capable of achieving both low density, high flowability and high strength even in a cyclopentane prescription. In other words, as a result of filling the refrigerator with a low density and high strength cyclopentane prescription urethane material, it is possible to reduce the cost and weight by reducing the amount of heat insulator. From the standpoint of global environmental protection, products such as high-quality refrigerators using cyclopentane blowing agents are achieved. However, polyurethane foams using a cyclopentane blowing agent have a large problem that the saturated vapor pressure is smaller than that of the conventional blowing agent, so that the pressure in the bubble cell is also lowered, shrinkage is likely to occur, and the strength and the like are lowered. In other words, the foam strength and the compressive strength are generally in a non-relationship, and as the density increases, the compressive strength tends to increase. This means that the higher the foam density, the higher the proportion of polyurethane resin, and the higher the compressive strength of the foam. For example, in order to set the compressive strength to 0.1 Mpa or more, the overall density of the skin layer is usually 38 kg / m 3 or more, and it is difficult to achieve both low density and high strength with the urethane material of cyclopentane prescription. Therefore, in order to secure the strength mainly, the rigid polyurethane foam of the cyclopentane prescription of the present development uses urethane with a density of 38 kg / m <^3> or more, filling a large amount of material in the space in a cabinet wall, and manufacturing a heat insulating material. For this reason, a high-performance cyclopentane prescription urethane is required from the standpoint of protecting the global environment by foaming and filling a compatible material having low density and excellent high flowability, compressive strength and dimensional stability. have.

An object of the present invention is to reduce the filling amount by filling the urethane insulation material of cyclopentane prescription that can achieve both low density and high strength in the rigid polyurethane foam foam-filled insulation box used for refrigerators and freezers Low-cost, light-weight, compressive strength, dimensional stability, and high fluidity, energy saving by heat leakage can be achieved, and high-performance insulation box can be manufactured stably with good manufacturing efficiency (quantity of production). It is to provide a refrigerator provided.

In addition, another object of the present invention is to provide a refrigerator having a heat insulating door that can achieve energy saving as described above and can be manufactured with good production efficiency.

1 is a schematic diagram of filling a rigid polyurethane foam by four-point injection,

2 is a graph showing the relationship between the distance from the inlet of the heat insulating material and the heat insulating material density,

Figure 3 is a schematic diagram of filling a rigid polyurethane foam by the insulation problem.

<Description of the code>

1: insulation box, 2: urethane injection head, 3: urethane flow, 4: urethane injection port,

5: sampling position, 6: measuring sample, 7: sampling position (up to 500mm or more from the inlet), 8: insulation style, 9: urethane sample, 10: sampling distance A (50mm or more away from the side of the envelope material) Place).

In order to develop an optimal rigid polyurethane foam for use in refrigerators and freezers, the present inventors have found that rigid and soluble properties are the specific measures to balance the low density, high flowability and urethane resin strength (cell) strength required in the cyclopentane prescription. Reduction of the solvent plasticization effect on the cells of the cyclopentane blowing agent, which makes it possible to completely encapsulate the blowing agent in the cell by the selection of a low polyol, and also by using a large amount of water blending in combination with the cyclopentane blowing agent, As a result of earnestly examining a method of increasing the carbon dioxide partial pressure to increase the cell internal pressure, the following findings were obtained and the present invention was completed.

That is, the first object is

[1] A heat insulation box of a refrigerator formed by filling a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water in a space formed between an outer box and an inner box of the refrigerator, wherein at least 500 from the inlet of the rigid polyurethane foam 30-35 g / of heat insulating material filled in the space using a material having a total density of 34 to 37 kg / m3, a compressive strength of 0.1 Mpa or more and a bending strength of 0.4 Mpa of the rigid polyurethane foam separated by ㎜ or more, It is achieved by L injection.

[2] The core layer heat insulating material having a thickness of about 20 to 25 mm in the polyol component of the rigid polyurethane foam containing 60 parts by weight or more of a component having low cyclopentane solubility and at least 500 mm or more away from the urethane inlet. The thermal conductivity is 18.0-18.5mW / mK at an average temperature of 10 ° C, the core layer density is 32-34kg / m3, and the dimensional change rate is 2% or less when left for 24 hours at 70 ° C and -20 ° C in air. It is achieved by constructing the heat insulating material which has the fluidity | strength of 2.6 mm / g or more of foam extension per resin.

The polyol component having low cyclopentane solubility is defined as a polyol component having low cyclopentane solubility as a polyol mixed system which becomes opaque when 10% by weight of cyclopentane is mixed in the polyol.

[3] The polyol component of the rigid polyurethane foam includes a mixture of triylenediamine, glycerin, sucrose, and bisphenol A having a low cyclopentane solubility and at least 60 parts by weight, and a mixture of ethylene oxide or propylene oxide added to triethanolamine. It is achieved by forming an isocyanate component from the heat insulating material obtained by making it react in the mixed foaming agent which combined 2.0-2.5 weight part water and 10-14 weight part cyclopentane with respect to 100 weight part of a catalyst, a foam stabilizer, and a polyol mixture.

[4] The OH obtained by adding ethylene oxide and propylene oxide to trilenediamine as the polyol component of the rigid polyurethane foam is added to ethylene oxide and propylene oxide to 40 to 50% by weight of polyol having 380 to 480, and to triethanolamine. OH obtained by adding 10-20 weight% of 300-400 polyols and propylene oxide to glycerin, 15-25 weight% of OH obtained 450-500 polyols, and OH obtained by adding propylene oxide to sucrose 400-450 Hard polyurethane foam having a polyol of 5 to 10% by weight and a mixture containing 5 to 15% by weight of polyol of 200 to 300 obtained by adding ethylene oxide to bisphenol A, wherein the average OH value of this polyol is 350 to 450 It is achieved by configuring with a heat insulating material using.

If the average OH value of the mixed polyol composition is less than 350, the compressive strength or dimensional stability decreases, and if it exceeds 450, the foam tends to recede, and the average OH value is preferable in producing a rigid polyurethane foam having a stable 350 to 450. . Here, OH value is the number of mg (mgKOH / g) of potassium hydroxide required to neutralize acetic acid bound to the acetylide obtained from the sample 1g.

[5] The above-mentioned object is also directed to a refrigerator having a heat insulating door formed by filling a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water in a space between an iron plate and an inner door wall of an outer door of a refrigerator and a freezer. In the urethane filling part at least 50mm away from the outer side, the urethane material with a total density of 35 ~ 38kg / m3, compressive strength of 0.1Mpa or more and bending strength of more than O.4Mpa is used in the space inside the door. The heat insulating material to be filled is achieved by providing the heat insulation door inject | poured 36-42 g / L seal | sticker with respect to the inside volume.

[6] A core layer heat insulating material having a thickness of about 20 to 25 mm in a polyol component of a rigid polyurethane foam containing 60 parts by weight or more of a component having low cyclopentane solubility and having a urethane filling portion at least 50 mm or more away from the outer surface of the door. Thermal conductivity of 18.0-19.0mW / mK at average temperature 10 ℃, core layer density of 32.5-34.5kg / m3 and dimensional change rate of 2% or less when left for 24 hours at 70 ℃ and -20 ℃ It is achieved by providing a heat insulating door having a heat insulating material having flowability of 2.6 mm / g or more of foam extension per resin.

The polyol component having low cyclopentane solubility is defined as a polyol component having low cyclopentane solubility as a polyol mixed system which becomes opaque when 10% by weight of cyclopentane is mixed in the polyol.

[7] The polyol component of the rigid polyurethane foam is a mixture in which triethylenediamine, glycerin, sucrose, and bisphenol A have at least 60 parts by weight of cyclopentane solubility and ethylene oxide or propylene oxide added to triethanolamine, and an isocyanate component. It is achieved by providing a heat insulating door having a heat insulating material obtained by reacting in a mixed foaming agent combining 2.0 to 2.5 parts by weight of water and 10 to 4 parts by weight of cyclopentane with respect to 100 parts by weight of a catalyst, foam stabilizer and polyol mixture.

[8] OH obtained by adding ethylene oxide and propylene oxide to triylenediamine as a polyol component of hard polyurethane foam is added to ethylene oxide and propylene oxide to 40 to 50% by weight of polyol having 380 to 480 and triethanolamine. OH obtained by adding 10-20 weight% of 300-400 polyols and propylene oxide to glycerin, 15-25 weight% of polyols of 450-50000, and OH obtained by adding propylene oxide to sucrose 400-450 Hard polyurethane foam having a polyol of 5 to 10% by weight and OH obtained by adding ethylene oxide to bisphenol A containing 5 to 15% by weight of polyol of 200 to 300, and having an average 0H value of 350 to 450 of this polyol. It is achieved by providing the heat insulation door which has a heat insulating material using.

<Example>

The rigid polyurethane foam of this invention is obtained by making isocyanate react in presence of a cyclopentane, a water, a foaming agent, and a reaction catalyst using a polyol component as a basic raw material. Since the cause of achieving low density, high flowability, and high strength in cyclopentane prescription is not so obvious, the relationship between solubility, compressive strength, and dimensional stability of cyclopentane foaming agents in various polyols was investigated. As a result, it was found that the compound having lower solubility was superior to the urethane foam in compressive strength and dimensional stability than the polyol had higher solubility in cyclopentane. The solubility of cyclopentane differs according to the alkylene oxide to add, and the polyol has the property to which solubility becomes higher when propylene oxide is added rather than ethylene oxide. In view of the premix stability of the polyol, a system having high solubility in cyclopentane is preferred, and a system having a low solubility is preferable in view of improvement of cell skeleton strength. In other words, it was found that the balance between compatibility with the foaming agent and the foam strength is an important factor in the selection of the polyol mixture composition.

The rigid polyurethane foam of the present invention uses an optimal foam stabilizer in order to increase the resin skeletal strength of the bubble cell and improve the premixing stability by using 60 parts or more of a low polyol system as opposed to a polyol system having high solubility in cyclopentane. It was chosen to achieve balance. At that time, when the mixed polyol is less than 60 parts by weight of the polyol having low solubility, the compressive strength and the dimensional stability tend to decrease. This is considered to be due to the fact that the rigid polyol having lower solubility has a stronger urethane resin wall than the cyclopentane, and the foaming agent is sufficiently encapsulated in the bubble, resulting in lower solvent plasticization of the cyclopentane.

In addition, in order to reduce the amount of heat leakage of the refrigerator and the freezer, it was also found that the heat insulating material of the foam was reduced, and the heat insulating material having a small difference in the surface state of the skin layer and the core layer of the foam was excellent. The reason is that the low density and high flowability urethane material is less likely to be resinized (double skin) or the like in the skin layer portion as in the core layer portion, and the shape in the wall of the refrigerator cabinet is bent intricately. The urethane material exhibiting properties is considered to be due to the formation of a uniform foam having a small difference in density between the skin layer and the core layer and a bubble cell diameter distribution difference.

In order to achieve a low density, high flowability and high strength urethane material which is an object of the present invention, the amount of water blending of the cyclopentane and the auxiliary foaming agent of the blowing agent also greatly influences.

According to the previous knowledge, it is known that the foam density is easily reduced when both the cyclopentane and the water blend amount are used. In the conventional foaming agent, since the skeletal strength in the foam cell is relatively high, by using a large amount of foaming agent such as fron and substitute fron, a small amount of water mixture which adversely affects the thermal conductivity is used, thereby achieving low density, high flowability, and high strength. I could make it. However, in the case of the cyclopentane prescription excellent in the global environment, unlike the conventional foaming agent, when the foam density is lowered, the saturated medium pressure is low, so that the skeleton strength in the bubble cell is weakened, resulting in poor foam shrinkage, compressive strength, and dimensional stability. Therefore, as a means of increasing the saturated vapor pressure of the cyclopentane prescription, in contrast to the conventional foaming agent, by reducing the compounding amount of the cyclopentane foaming agent and increasing the water compounding amount which adversely affects the thermal conductivity, the carbon dioxide gas in the cell is increased to increase the carbon dioxide gas in the cell. The examination which improved pressure and made both low density and high strength was performed. At that time, the amount of water blended into the cyclopentane may cause layer separation or worsen thermal conductivity during premixing when the solubility is close to the limit value. However, it was found that cyclopentane prescription has a smaller effect of water on thermal conductivity than conventional blowing agents. As for the optimum compounding ratio of water and cyclopentane, it is preferable that cyclopentane is 7 weight part or less with respect to 1 weight part of water. That is, it is more preferable to use 2.0-2.5 weight part water and 10-1 4 weight part cyclopentane with respect to 100 weight part of polyol components. If the water content is less than 100 parts by weight of the polyol component, the compressive strength or dimensional stability is lowered. If the water content is more than the water content, the thermal conductivity tends to be significantly deteriorated. In addition, when the amount of cyclopentane foaming agent exceeds the blending amount, the compressive strength and the dimensional stability are inferior.

Other polyols used in the present invention include polyester polyols.

For example, polyols of polyhydric alcohols, polyhydric carboxylic acid condensation systems and cyclic ester ring-opening polymers can also be used. Ethylene glycol, glycerin, trimethylolpropane as the polyhydric alcohol, and sucrose and sorbitol as the saccharide. As the alkanolamine, diethanolamine, triethanolamine, and polyamine may be ethylenediamine, triylenediamine, bisphenol A, etc., and as polyhydric carboxylic acid, adipic acid, futalic acid, polyhydric carboxylic acid and the like can be used. As for the quantity of polyester polyol, 5-20 weight part of mixing systems are preferable.

As the reaction catalyst, for example, a phosphate of a tertiary amine such as tetramethylhexamethylenediamine, trimethylaminoethyl pipeladine, pentamethyldiethylenetriamine, triethylenediamine and trimethylaminoethyl pipeladine I) and a reactivity catalyst such as a slow-release catalyst such as dipropylene glycol combined use, all conventionally known catalysts can be used. The amount of the reaction catalyst is preferably 3 to 5 parts by weight per 100 parts by weight of the polyol component.

As the foam stabilizer, the Si molecular weight is 1800 to 3000, for example, because of the stability of premix compatibility such as X-20-1548, X-20-1614, and X-20-1634 manufactured by Shin-Etsu Chemical Co., Ltd. It is more preferable that it is suitable for the comparatively low emulsification action having a content of 25 to 30. That is, it is also possible to use an organosilicon compound, a fluorine compound or the like which is an alkylene oxide-modified polydimethylsiloxane and has an OH group or an alkoxy group at its terminal. The amount of foam stabilizer is preferably 1 to 4 parts by weight per 100 parts by weight of the polyol component.

Filler used normally as a mixed composition for rigid polyurethane foams as needed. Additives, such as a flame retardant, a reinforcing fiber, and a coloring agent, can also be contained.

As the isocyanate, any known one can be used, but most commonly, is triylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI), and TDI is a mixture of isomers, that is, 2,4-body. ) 100%, 2, 4-body / 2, 6-body = 80/20, 65/35 (weight ratio), as well as the multifunctional, such as Mitsui Cosmonate TRC, Takeda Pharmaceutical Take 4040 Coarse TDI containing tar can also be used. As the MDI, a polymeric MDI such as Mitsui Cosmonate M-200 containing a polynuclear body or a polyhedral body of three or more nuclei in addition to a pure product mainly composed of 4, 4'-diphenylmethane diisocyanate, and Milionate MR of Takeda Pharmaceutical Co., Ltd. may be used. Can be. In addition, polymethylene polyphenyl is aromatic or aliphatic polyfunctional isocyanate represented by isocyanate, 1, 6-hexamethylene diisocyanate, etc., urethane modified triylene diisocyanate, carbodiimide modified diphenylmethane diisocyanate, etc. Modified isocyanates of can also be used. These polyfunctional isocyanates can be used individually or as a mixture of 2 or more types. Moreover, the weight% (NCO%) of the isocyanate group in isocyanate defined by following formula 1 is mentioned as a characteristic of isocyanate.

NCO% = ([NCO] × f (iso) / Mw (iso)) × 10

[NCO] is the molecular weight of the isocyanate group, f (iso) is the number of functional groups of the isocyanate group, Mw (iso) represents the molecular weight of the isocyanate. When NC0% of an isocyanate is less than 31, fluidity falls and when it exceeds 33, dimensional stability falls. For this reason, NC0% is preferable in manufacturing rigid polyurethane foam which is 31-33.

Foaming of the rigid polyurethane foam of the present invention is formed with a conventional foaming machine used in the art, for example, PU-30 type foaming machine made by Bromat. Foot conditions are slightly different depending on the kind of foaming is usually a liquid temperature of 18~30 ℃, discharge pressure 80 ~150kg / cm ^2. As for discharge amount 15-30 kg / min, and the temperature of a box, 35-45 degreeC is preferable.

More preferably, liquid temperature is 20 degreeC, discharge pressure 100 kg / cm <^2> , discharge amount 25 kg / min, and the temperature of a box is 45 degreeC vicinity.

The rigid polyurethane foam foamed and filled into the refrigerator and freezer obtained in this way is filled with a urethane material capable of achieving low density, high flowability, and high strength, thereby enabling low cost and light weight due to the effect of reducing the amount of foam filling. do. In addition, since the foam has excellent compressive strength, dimensional stability, and high fluidity, the amount of heat leakage is also reduced, and energy saving is achieved.

The embodiment of the present invention will be described in more detail in comparison with a comparative example. In addition, in description of an Example, a part and% represent a weight part.

EXAMPLES 1-6

Comparative Examples 1-3

Triylene diamine polyether polyol with an average hydroxyl value of 380 to 480 and ethylene oxide added (referred to as polyol A), propylene oxide with an average hydroxyl value of 300 to 400 and triethanolamine polyether with ethylene oxide added Ether polyol (called polyol B), glycerin-based polyether polyol (polyol C) added with propylene oxide having an average hydroxyl value of 450 to 500, and sucrose type added with propylene oxide having an average hydroxyl value of 400 to 450 Polyether polyol (also referred to as polyol D), bisphenol A-based polyether polyol to which ethylene oxide having an average hydroxyl value of 20/3/3 is added (called polyol E), and to which propylene oxide having an average hydroxyl value of 400 to 750 is added Trimethylolpropane polyether polyol (referred to as polyol F), and triylenediamine based on addition of ethylene oxide having an average hydroxyl value of 250 to 450 100 parts by weight of a mixed polyol component (an average hydroxyl value of 350 to 450) of a liether polyol (hereinafter referred to as polyol G) is used as a blowing agent, 2.0 parts of water, 13 parts of cyclopentane (manufactured by Nippon Zeon), and trimethylamino as a reaction catalyst. 1.6 parts of ethyl pipeladine (manufactured by Huawang Co., Ltd.), trimethylaminoethyl pipeladine (manufactured by Tosoh Corporation), 2.4 parts, dipropylene glycol liquid (manufactured by Tosoh Corporation) 0 tripart of triethylenediamine, organic group silicone as a foam stabilizer Two parts of a compound (X-20-1614, manufactured by Shin-Etsu Chemical Co., Ltd.) and polymethylene polyphenyl diisocyanate (NCO% = 31) were charged and foamed to prepare a rigid polyurethane foam. First, Table 1 shows the physical properties and characteristics results of the heat insulating material filled with rigid polyurethane foam by four-point injection shown in FIG. 1. In addition, the physical properties and characteristics of Table 1 were examined as follows.

Skin layer total density: Measure the weight (A) of the skinned foam of 50 mm x 50 mm x 35 tmm at the urethane-filled insulation part at least 500 mm away from the urethane inlet. After zero-adjusting the foam attached to the distilled water and the metal needle in the beaker by balance, the volume (B) when the foam was submerged with the metal needle was measured and the value obtained by dividing the weight (A) by the volume (B) was evaluated. .

Core layer density: In the urethane-filled insulation portion at least 500 mm away from the urethane inlet, a foam of 200 mm x 200 mm x 20 to 25 tmm was divided by the volume after the measurement of the dimensions and weight.

Embodiments of the present invention and comparative examples will be described below according to manufacturing contents for filling rigid polyurethane foam in the outer wall of the refrigerator and freezer and the cabinet wall of the inner box.

FIG. 1 shows a flow diagram in which a rigid polyurethane foam is filled by four-point injection and a foam, and shows a schematic diagram of a measurement sample. First of all, a steel outer box and a plastic inner box are assembled, and a box before urethane foam is filled to fill the refrigerator. The foam box is placed in a urethane foam box, and then preheated to form a rigid polyurethane foam in the void portion ( Polyol mixture and water, cyclopentane, catalyst and foam stabilizer is foamed and filled into the mixed composition and isocyanate). At that time, the polyol of the urethane foam and the isocyanate are chemically reacted and pressurized by the foaming pressure, and the foamed urethane foam is injected into the cabinet of the refrigerator to form a heat insulating box.

After setting the zero pack (referred to as the minimum injection amount required for filling the actual machine) of the urethane materials of Examples 1 to 6 and Comparative Examples 1 to 3, the urethane was applied to the refrigerator of the box body in which the urethane material was injected at a pack rate of 110%. Foam samples were taken from the urethane-filled insulation part at least 500 mm away from the inlet and evaluated for various properties and properties. At the time of injection, the liquid temperature of about 45 degreeC and a polyol liquid and an isocyanate liquid was performed at about 20 degreeC, The result is shown in Table 1. In Table 1, the heat insulating material according to the embodiment of the present invention has a lower skin layer density and core layer density, a lower temperature change rate, a higher temperature change rate and a smaller bubble cell diameter distribution, and a lower thermal conductivity than the heat insulating material of the comparative example. It has become clear that the strength and the bending strength are also increased, and the foam extension is improved.

In addition, in Example 1 and Comparative Examples 1 and 2, the amount of urethane actual charge at the time of pack rate of 110% was evaluated using the refrigerator of about 150-180 L of space in the cabinet wall space.

As a result, in the refrigerator having a volume of about 180 L, although the filling amount of 6.35 to 6.50 kg is required in the refrigerator having a volume of about 180 L, the urethane material of Examples 1 and 2 is 5.45 to 5.90 kg of filling amount. I could see a good thing. In addition, in the refrigerator having an internal volume of about 150L, the urethane material of Comparative Examples 1 and 2 is 5.35-.5.65 kg, whereas in Examples 1 and 2, the filling amount of 4.65 to 5.00 kg can be reduced, and about 10 to 18% It was confirmed that the urethane material can be saved. In addition, as a result of re-assembling the refrigeration cycle components (compressor / condenser / evaporator) in the refrigerator in which the heat insulating material was formed, the amount of heat leakage was measured. As a result, it was found that energy saving of about 1 to 2 Kwh / month is possible.

For this reason, the rigid polyurethane foam of the present invention has low density, high flowability and high strength, so that the cost of urethane foam filling is reduced, the weight is reduced, the compressive strength and dimensional stability of the foam are excellent, and the amount of heat leakage is also reduced. Energy saving was also achieved by the effect.

It shows the physical properties and characteristics of the rigid urethane foam (skin layer density, core layer density, dimensional change rate, cell diameter distribution, thermal conductivity, compressive strength, bending strength, foam elongation).

According to the present embodiment, in the insulating box in which the low density, high flowability and high strength rigid polyurethane foam is foam-filled, the urethane filling amount can be further reduced and the weight can be reduced, and the compressive strength and the dimensional stability are excellent. In addition, it is possible to provide a high quality refrigerator and a freezer, which can be energy-saved by the effect of reducing the amount of heat leakage.

Low temperature dimensional change rate: The rate of change in thickness dimension when 150mm × 300mm × 20-25tmm foam was left at -20 ° C for 24 hours in the urethane-filled insulation part at least 500mm away from the urethane inlet was evaluated.

High temperature dimensional change rate: The thickness dimensional variation was evaluated when the foam of 150 mm × 300 mm × 20-25 tmm was left at 70 ° C. for 24 hours in the urethane-filled insulation part at least 500 mm away from the urethane inlet.

Thermal conductivity: Use the HC-073 type (heat flow meter, average temperature 10 ℃) manufactured by Young Hong Jeonggi Co., Ltd. with foam of 200mm × 200mm × 20 ~ 25tmm in urethane filled insulation part at least 500mm away from urethane inlet. Evaluated.

Compressive strength: 50mm × 50mm × 20 ~ 25tm foam is loaded at 4mm / min in the urethane-filled insulation part at least 500mm away from the urethane inlet, and the load at 10% deformation is divided by the original hydraulic area. Was evaluated.

Bending strength: Load 80mm × 250mm × 20 ~ 25tm foam at 10mm / min in the urethane filled insulation part at least 500mm away from the urethane inlet, and load the foam at the time of foam breakage. The value divided by the power of 2 was evaluated.

Foam Elongation: The foam elongation per urethane filling amount when foamed in an inverted L panel of 550 mm x 580 mm x 35 tmm was evaluated.

The reason why the distance from the injection port of urethane which is a heat insulating material to be filled to the position which evaluates the characteristic of urethane is 500 mm or more is shown in FIG. Fig. 2 is a diagram showing the relationship between the distance from the injection port of the heat insulating material and the density of the heat insulating material.

As shown in this figure, in the area where the distance from the injection port is small, the density is not stable because the change of the density of the heat insulating material with respect to the distance is large. This is because the thermally insulated film injected is poor in mixing properties, and because of this, the fluidity of the thermally insulated material is low, so that a portion (called a skin layer) in which the thermally insulated resin is increased. In this invention, all the characteristics of the heat insulating material were evaluated in the part from which the distance from the injection hole which is a part (referred to as a core layer) with few densified resin parts to which density was stabilized.

EXAMPLES 7-12

Comparative Examples 4 to 6

Tylenediamine-based polyether polyol added with propylene oxide and ethylene oxide having an average hydroxyl value of 380 to 480 (called polyol A), propylene oxide having an average hydroxyl value of 300 to 400 and triethanolamine added with ethylene oxide

Polyether polyol (referred to as polyol B), glycerin-based polyether polyol (referred to as polyol C) added with propylene oxide having an average hydroxyl value of 450 to 500, and sucrose added to propylene oxide having an average hydroxyl value of 400 to 450. Polyether polyol (called polyol D), bisphenol A-based polyether polyol (polyol E) added with ethylene oxide having an average hydroxyl value of 200 to 300, and propylene oxide having an average hydroxyl value of 400 to 750 added Mixed polyol component (average hydroxyl value of 350) of trimethylolpropane polyether polyol (referred to as polyol F) and triylenediamine polyether polyol (referred to as polyol G) to which ethylene oxide with an average hydroxyl value of 250 to 450 is added 450 parts by weight of 2.0 to 2.5 parts of water as a blowing agent, 10.5 to 14 parts of cyclopentane (manufactured by Nippon Zeon), and trimethylaminoethyl pipeladine (manufactured by Hwawang) as a reaction catalyst. Organosilicon compound (X-20-1614, Shin-Etsu Chemical) as 6 parts and acid salt (made by Tosoh Corporation) 2.4 parts of trimethylaminoethyl pipeladine, 0.4 parts of dipropylene glycol liquids (made by Tosoh Corporation) of triethylenediamine Company) 2 parts and polyfoamed polystyrene diisocyanate (NC0% = 31) as an isocyanate component were filled and foamed, and the rigid polyurethane foam was produced. First, Table 2 shows the physical properties and characteristics results of the heat insulating material filled with the rigid polyurethane foam in the style shown in FIG. In addition, each physical property and the characteristic of Table 2 were investigated as follows.

Skin layer overall density: Measure the weight (A) of the skinned foam of 50 mm x 50 mm x 35 tmm in the urethane filled insulation part at least 50 mm away from the outer surface of the door. After zero-adjusting the foam attached to the distilled water and the metal needle in the beaker by balance, the volume (B) when the foam was submerged with the metal needle was measured and the value obtained by dividing the weight (A) by the volume (B) was evaluated. .

Core Layer Density: In the urethane-filled insulation portion at least 50 mm away from the outer surface of the door, the dimensions of 200 mm x 200 mm x 20-25 tmm were measured and measured, and the weight divided by volume.

Low temperature dimensional change: The rate of change in the thickness dimension of a 150 mm × 300 mm × 20 to 25 tmm foam in a urethane-filled insulator portion at least 50 mm away from the outer surface of the door when left at −20 ° C. for 24 hours was evaluated.

High temperature dimensional change rate: The rate of change in the thickness dimension of a 150 mm × 300 mm × 20 to 25 tmm foam in a urethane-filled insulator portion at least 50 mm away from the outer surface of the door was left at 70 ° C. for 24 hours.

Thermal Conductivity: 200mm × 200mm × 20 ~ 25tmm foam in urethane-filled insulation part at least 50mm away from the outer side of the door, type HC-073 (heat flow method, average temperature 10 ℃) manufactured by Younghong Jeonggi Co., Ltd. ) Was evaluated.

Compressive strength: Load 50mm × 50mm × 20 ~ 25tmm foam at 4mm / min of feed rate at the urethane-filled insulation part at least 50mm away from the outer side of the door, and divide the load at 10% deformation by the original hydraulic area. The value was evaluated.

Bending strength: Load 80mm × 250 × 20 ~ 25tmm foam at 10mm / min supply rate from urethane filled insulation part at least 50mm away from the outer surface of the door, and load the foam at the time of foam breakage The value divided by the square of the thickness was evaluated.

Foam Elongation: The foam elongation per urethane filling amount when foamed in an inverted L panel of 550 mm x 580 mm x 35 tmm was evaluated.

Embodiments of the present invention and comparative examples will now be described according to manufacturing contents for filling rigid polyurethane foam in the steel plate and the inner wall of the outer door surface of the refrigerator and freezer.

In FIG. 3, the foam | bubble filled with a rigid polyurethane foam is collected by the heat insulating body, and the schematic diagram of a measurement sample is shown. First, the vegetable door, the refrigerator door, and the freezer door are manufactured by assembling the steel outer door and the plastic inner door and filling the refrigerator door. The urethane foam is foam-filled into the void portion (a mixture of polyol and a mixed composition and isocyanate premixed with water, cyclopentane, a catalyst and a foam stabilizer). At that time, the polyol and the isocyanate of the urethane foam are chemically reacted and pressurized by the foaming pressure, and the foamed urethane foam is injected into the wall of the refrigerator door to form a heat insulating door.

The urethane materials of Examples 7 to 12 and Comparative Examples 4 to 6 were set to zero pack (referred to as the minimum injection amount required for actual filling). Foam samples were taken from the urethane-filled insulator portion at least 50 mm away from the outer side of the door, and various properties and properties were evaluated. The temperature at the time of injection at that time was about 45 degreeC, and the liquid temperature of a polyol liquid and an isocyanate liquid was performed at about 20 degreeC. The results are shown in Table 2. In Table 2, the heat insulating material according to the embodiment of the present invention has a lower skin layer density and core layer density, a low temperature change rate, a high temperature change rate and a smaller bubble cell diameter distribution, and a lower thermal conductivity than the heat insulating material of the comparative example. It is also apparent that the bending strength is also increased, and the foam extension is improved.

Moreover, about the urethane actual charge amount at the pack rate of 115 to 120% about Example 7, 8 was evaluated using the refrigerator of about 12-20 L of interior space of a door wall. As a result, in the refrigerator having a volume of about 20L, although the amount of filling is 0.90 to 1.05kg, the filling amount of the urethane material of Example 7, 8 is 0.76 to 0.82kg. I could see a good thing. Moreover, in the refrigerator of about 12L in contents, the urethane material of Comparative Examples 4 and 5 is 0.59-0.68 kg, whereas in Example 7,8, the filling amount of 0.47-0.52 kg can be reduced and about 10-18% of urethane is We can see that we can save material. In addition, after assembling refrigeration cycle parts (compressor / condenser / evaporator) in the refrigerator with heat insulation and mounting them on the door, the amount of heat leakage was measured. It was found that the energy saving of about 1 to 2 Kwh / month is possible with the power saving of -6%.

For this reason, the rigid polyurethane foam of the present invention has low density, high flowability and high strength, so that the cost of urethane foam filling is reduced, the weight is reduced, the compressive strength and dimensional stability of the foam are excellent, and the amount of heat leakage is also reduced. Energy saving was also achieved by the effect.

The properties and properties (skin layer density, core layer density, dimensional change rate, thermal conductivity, compressive strength, bending strength, foam elongation, bubble cell diameter distribution) of the rigid urethane foam are shown.

According to this embodiment, it is possible to reduce the cost of urethane and reduce the weight by reducing the amount of urethane in the foam door filled with low density, high flowability and high strength rigid polyurethane foam, and also excellent in compressive strength and dimensional stability. It is possible to provide high quality refrigerators and freezers that can be energy-saved by the effect of reducing the amount of heat leakage.

In addition, the area where the heat insulating material is evaluated is a part having a distance of 50 mm or more from the outer surface of the door (end surface of the door), as in the case of the heat insulating box, the fluidity of the heat insulating material is poor in the vicinity of the end surface of the door, and many parts have been resinized. This is to avoid the skin layer so that all properties can be evaluated at the stable generation and filling of the insulation.

As described above, according to the present invention, the urethane filling amount can be reduced and the weight can be reduced by reducing the amount of urethane in the insulation box and the insulation door in which the low density, high flowability and high strength rigid polyurethane foam is foam-filled. It is possible to provide a high quality refrigerator and a freezer which are excellent in compressive strength and dimensional stability and which can also save energy by reducing heat leakage.

Claims (11)

In the refrigerator provided with the heat insulation box which fills the space formed between the outer box and the inner box of the refrigerator with the hard polyurelan foam which used the mixed foaming agent of cyclopentane and water, In the space using a material having a total density of 34 to 37 kg / m ³ , a compressive strength of 0.1 Mpa or more, and a bending strength of 0.4 Mpa or more, at least 500 mm or more from the injection hole of the rigid polyurethane foam. A refrigerator provided with a heat insulation box in which 30 to 35 g / L of insulator to be filled is injected. In claim 1, The thermal conductivity of the core layer heat insulating material having a thickness of about 20 to 25 mm in a planar portion at least 500 mm away from the urethane inlet, wherein the polyol component of the rigid polyurethane foam contains a component having low cyclopentane solubility, has an average temperature of 10 ° C. in 18.0~18.5mW / mK, the core layer density is 32~34kg / m ³ and air is from 70 ℃ and dimensional change is 2% or less, foam expansion amount of the resin per 24 hrs degradation allowed to stand at a temperature of -20 ℃ 2.6mm Refrigerator with a heat insulation box which is a heat insulating material having a fluidity of / g or more. The method of claim 1, The polyol component of the rigid polyurethane foam is a catalyst and foaming mixture of isotropic triylenediamine, glycerin, sucrose and bisphenol A having low cyclopentane solubility and a mixture of ethylene oxide or propylene oxide added to triethanolamine and an isocyanate component. The refrigerator provided with the heat insulation box which is a heat insulating material obtained by making it react in the mixed foaming agent which combined 2.0-2.5 weight part water and 10-14 weight part cyclopentane with respect to 100 weight part of polyol mixtures. The method of claim 1, OH obtained by adding ethylene oxide and propylene oxide to trilenediamine as polyol component of said rigid polyurethane foam 40-40 weight% of polyols with 380-480, OH obtained by adding ethylene oxide and propylene oxide to triethanolamine 300 10 to 25% by weight of the polyol of -400, 5 to 10% by weight of OH obtained by adding propylene oxide to 5 to 10% by weight of OH obtained by adding ethylene oxide to 450 to 500 DML VHFFLDHF and bisphenol A was added. A refrigerator provided with a heat insulation box which consists of a mixture to contain and which is a heat insulating material using hard polyurethane foam whose average OH value of this polyol is 350-450. A refrigerator provided with a heat insulating door formed by filling a rigid polyurethane foam using a mixed foaming agent of cyclopentane and water in a steel plate on the outer door surface of a refrigerator and a freezer and a space inside the inner door wall, the urethane filling being at least 50 mm away from the outer surface of the door. in the portion where the skin layer of full density rigid polyurethane foam 35~38kg / m ³ and a compression strength of 0.1Mpa or more, a heat insulating material for using a urethane material having a flexural strength of 0.4Mpa charging contact intramural space information about enemy 36~ 42g / L Refrigerator with insulated doors. The method of claim 5, The thermal conductivity of the core layer insulation material having a thickness of about 20 to 25 mm in the urethane filling portion containing at least 50 parts by weight of the polyol component of the hard polyurethane groove containing a component having low cyclopentane solubility and at least 50 mm or more from the outer surface of the door is average temperature. at 10 ℃ 18.0~19.0mW / mK, core layer portion density 32.5~34.5kg / m ³ and 70 ℃ and the dimensional change is 2% or less, foam expansion amount of the resin per 24 hrs degradation allowed to stand at a temperature of -20 ℃ 2.6 Refrigerator with a heat insulated door having a heat insulating material having a fluidity of at least mm / g. The method of claim 5, The polyol component of the rigid polyurethane foam is a catalyst and foaming mixture of isotropic triylenediamine, glycerin, sucrose and bisphenol A having low cyclopentane solubility and a mixture of ethylene oxide or propylene oxide added to triethanolamine and an isocyanate component. The refrigerator provided with the heat insulation door which has a heat insulating material obtained by making it react in the mixed foaming agent which combined 2.0-2.5 weight part water and 10-14 weight part cyclopentane with respect to 100 weight part of polyol mixtures. The method of claim 6, The polyol component of the rigid polyurethane foam is a catalyst and foaming mixture of isotropic triylenediamine, glycerin, sucrose and bisphenol A having low cyclopentane solubility and a mixture of ethylene oxide or propylene oxide added to triethanolamine and an isocyanate component. The refrigerator provided with the heat insulation door which has a heat insulating material obtained by making it react in the mixed foaming agent which combined 2.0-2.5 weight part water and 10-14 weight part cyclopentane with respect to 100 weight part of polyol mixtures. The method of claim 5, OH obtained by adding ethylene oxide and propylene oxide to triylenediamine as the polyol component of the rigid polyurethane foam is 40 to 50% by weight of polyol having 380 to 480, and 0H obtained by adding ethylene oxide and propylene oxide to triethanolamine is 300 Rigid polyurethane foam having 10 to 20% by weight of ˜400 polyol, OH obtained by adding propylene oxide to glycerin and 15 to 25% by weight of polyol of 450 to 500 and OH obtained by adding propylene oxide to sucrose Refrigerator with a heat insulated door having a heat insulating material using. The method of claim 6, OH obtained by adding ethylene oxide and propylene oxide to trilenediamine as polyol component of said rigid polyurethane foam 40-40 weight% of polyols with 380-480, OH obtained by adding ethylene oxide and propylene oxide to triethanolamine 300 OH obtained by adding propylene oxide to 10 to 20% by weight of -400 polyol, glycerine is 15 to 25% by weight of polyol of 450 to 500, and OH obtained by adding propylene oxide to sucrose 5 to 10 polyol of 400 to 450 OH obtained by adding ethylene oxide to weight% bisphenol A consists of a mixture containing 5 to 15% by weight of a polyol of 200 to 300, and has a heat insulating material using a rigid polyurethane foam having an average OH value of 350 to 450 of this polyol. Refrigerator with insulated door. The method of claim 7, wherein OH obtained by adding ethylene oxide and propylene oxide to trilenediamine as polyol component of said rigid polyurethane foam 40-40 weight% of polyols with 380-480, OH obtained by adding ethylene oxide and propylene oxide to triethanolamine 300 OH obtained by adding propylene oxide to 10 to 20% by weight of -400 polyol, glycerine is 15 to 25% by weight of polyol of 450 to 500, and OH obtained by adding propylene oxide to sucrose 5 to 10 polyol of 400 to 450 WT obtained by adding ethylene oxide to bisphenol A by weight%, and it consists of a mixture containing 5-15 weight% of polyols of 200-300, and has a heat insulating material using the polyurethane foam whose average OH value of this polyol is 350-450. Refrigerator with insulated door.