JP2012255140A - Hard polyurethane, premix polyol for manufacturing the same, thermal insulating box for refrigerator, thermal insulating door for refrigerator, method for manufacturing hard polyurethane, and refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the thermal insulation of a refrigerator by raising the fluidity of a urethane raw material and filling urethane in a thermal insulating box interior of the refrigerator.SOLUTION: A hard urethane foam contains cyclopentane as a foaming agent, and has a thermal conductivity at 10°C of 18.0 to 19.0 mW/m K, and a bending strength at 10°C of 0.3 MPa, and has, in the case where an infrared absorption spectral peak intensity at 1,700 to 1,720 cmis represented as A1, and an infrared absorption spectral peak intensity at 1,590 to 1,610 cmis represented as A2, A1/A2 of 1.2 to 1.7. A premix polyol forms the hard urethane foam.

Description

  The present invention relates to rigid polyurethane, a premix polyol for producing rigid polyurethane, a heat insulating box for refrigerator, a heat insulating door for refrigerator, a method for producing rigid polyurethane, and a refrigerator.

  Conventionally, a heat insulation box and a heat insulation door of a refrigerator are formed by filling a space between an outer box and an inner box with a hard urethane foam having bubbles. The rigid urethane foam is formed by reacting a polyol component, a catalyst, a premix polyol containing a foaming agent and a foam stabilizer, and an isocyanate component. Until now, urethane foam used as a heat insulating material for refrigerators has used trichloromonofluoromethane and hydrochlorofluorocarbon (HCFC), which are chlorofluorocarbon (CFC), which has low gas thermal conductivity, as a foaming agent. However, when CFC and HCFC are released into the atmosphere, the ozone layer in the stratosphere is destroyed and the surface temperature rises due to the greenhouse effect. Recently, cyclopentane is used as a blowing agent.

  The prescription using cyclopentane as a blowing agent is greatly inferior to conventional CFC and HCFC blowing agents and has a high density and poor fluidity, ensuring insulation performance and strength unless a large amount of urethane is used. However, urethane materials that can achieve both low density, high fluidity, and high strength characteristics have been developed even with cyclopentane formulations (Patent Documents 1, 2, and 3).

  On the other hand, in recent years, as energy demand increases, reduction of power consumption is also desired in home appliances from the viewpoint of global environmental conservation such as global warming. Under such circumstances, reduction of power consumption by improving heat insulation is also desired in refrigerators. Then, the heat insulation improvement of the refrigerator is aimed at using the vacuum heat insulating material in the heat insulation box of a refrigerator. Furthermore, in order to further improve the heat insulating performance, studies are being made to increase the thickness of the vacuum heat insulating material. However, if the vacuum heat insulating material is made thick, the space in which the urethane foam raw material flows inside the heat insulating box and the heat insulating door becomes narrow, and it becomes difficult to sufficiently fill the urethane foam. In addition, due to the demand for space saving in refrigerators, etc., the space in the heat insulation box and the heat insulation door becomes narrower and the shape becomes complicated, and the urethane foam raw material does not flow easily inside the heat insulation box and the heat insulation door. ing.

  Under such circumstances, in the formulation using cyclopentane as a foaming agent, which has been studied in the past, the fluidity of the urethane foam raw material is poor, and the urethane foam is sufficiently filled in the narrow part of the heat insulation box and the heat insulation door. I can't. If a space that is not filled with urethane foam is generated, the heat insulating property of the refrigerator is deteriorated and power consumption may be increased.

  In Patent Document 4, in order to suppress the influence of the heat bridge by increasing the area of the vacuum heat insulation panel and to prevent the heat leak from the bent portion of the vacuum heat insulation panel, a core material made of a transition assembly not containing a binder is provided. The technique used is disclosed.

Japanese Patent No. 3475762 Japanese Patent No. 3475763 JP 2003-042653 A JP 2009-228917 A

  The object of the present invention is to increase the fluidity of the urethane raw material (premix polyol) in order to sufficiently fill the urethane foam in the narrowed heat insulation box and urethane flow space in the heat insulation door, and to react the urethane raw material. It is intended to improve the heat insulation property of the refrigerator heat insulation box by adjusting the properties and sufficiently filling the heat insulation box of the refrigerator and the narrow portion inside the heat insulation door with the hard urethane foam. Thereby, it becomes possible to make compatible the high fluidity | liquidity of the urethane raw material with which the heat insulation box and heat insulation door of a refrigerator are filled, the low thermal conductivity of a urethane foam, and a high intensity | strength characteristic.

According to the present invention, the infrared absorption spectrum peak intensity of 1700 to 1720 cm ⁻¹ derived from the urethane bond of the polyurethane comprising cyclopentane as the foaming agent and constituting the rigid urethane foam is A1, and 1590 to 1610 cm ⁻¹ derived from the urea bond. When the infrared absorption spectrum peak intensity is represented by A2, it is possible to provide a rigid polyurethane foam characterized by A1 / A2 being 1.2 to 1.7, and this rigid urethane foam has excellent heat insulation properties. It is suitable as a heat insulating material for a heat insulating box of a refrigerator, improves the fluidity of the urethane raw material, and improves the heat insulating property of the heat insulating material.

  Moreover, in the premix polyol composition containing a polyol, a catalyst, water, cyclopentane, and a foam stabilizer, the gel time / cream time is 8 to 6 when reacted with an isocyanate equivalent of 1 for the polyol and water. The premix polyol can be provided, thereby optimizing the reactivity between the premix polyol and isocyanate, ensuring excellent fluidity, and sufficiently flowing even in a narrow part of the heat insulation box, An insulating box sufficiently filled with urethane foam can be obtained.

  The present invention also provides a method for producing a rigid urethane foam and a refrigerator using the rigid urethane foam in a vacuum insulation panel.

  The rigid urethane foam according to the present invention is excellent in heat insulation and mechanical strength, and the premix polyol for producing the above rigid polyurethane foam has a fluidity and reactivity with isocyanate without impairing the mechanical strength of the produced rigid polyurethane foam. It is possible to obtain a rigid polyurethane foam which is suitable and sufficiently flows even in a narrow space in the heat insulation box and has a good filling property. As a result, a heat-insulating box and a refrigerator with good heat insulating properties can be obtained.

The front view of the refrigerator with which this invention is applied. Sectional drawing of FIG. The B section enlarged view of FIG. The C section enlarged view of FIG. The schematic perspective view which shows an example of the structural method of a vacuum heat insulating material. The refrigerator heat insulation box which consists of an outer box iron plate and an inner box resin wall which are filled with rigid polyurethane foam by four-point injection is shown. Indicates the refrigerator door sample collection position. Sectional drawing of a refrigerator heat insulation door. Sectional drawing which shows an example of the refrigerator heat insulation door formation method. Sectional structure of a vacuum insulation panel for a refrigerator using conventional rigid urethane foam materials. Sectional structure of the vacuum heat insulation panel of the refrigerator using the rigid urethane foam raw material by this invention. It is a spectrum figure which shows the infrared absorption spectrum peak A1 derived from the urethane bond of rigid urethane foam, and the infrared absorption spectrum peak A2 derived from a urea bond. The urethane formation reaction diagram shown by cream time and gel time of the premix polyol by this invention and the conventional method is shown.

  Hereinafter, the present invention will be described in detail.

  First, the overall configuration of the refrigerator body 1 will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view of a refrigerator to which the present invention is applied, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The refrigerator body 1 includes a heat insulating box 20 and heat insulating doors 6a, 6b, 7a, 7b, 8, and 9 as main components. The heat insulation box 20 includes a top surface, a bottom surface, both side surfaces, and a back surface, and the front surface has an open box shape. And as shown in FIG. 2, the heat insulation box 20 has the refrigerator compartment 2, the ice making room 3a, the ice storage room 3b, the switching room, the freezer compartment 4, and the vegetable compartment 5 in this order from the top.

  The heat insulating doors 6a to 9 are doors that close the front opening portions of the respective chambers 2 to 5. Refrigerating room doors 6a and 6b, ice storage room door 7a, upper freezing room door 7b, lower freezing room door 8 and vegetable room door 9 are arranged corresponding to each of chambers 2-5. The refrigerator compartment doors 6a and 6b are double doors that rotate around the hinge 10, and all the doors other than the refrigerator compartment doors 6a and 6b are drawer type doors. When these drawer type doors 7 to 9 are pulled out, the containers constituting each chamber are pulled out together with the doors. Each of the doors 6 to 9 includes a packing 11 for sealing the heat insulating box 20. This packing 11 is attached to the indoor side outer periphery of each door 6-9.

  Moreover, between the refrigerator compartment 2, the ice making chamber 3a, and the upper stage freezer compartment 3b, the heat insulation partition 12 for partition heat insulation is arrange | positioned. The heat insulating partition 12 is a heat insulating wall having a thickness of about 30 to 50 mm, and is made of a foamed polystyrene, a foamed heat insulating material (for example, urethane foam), a vacuum heat insulating panel or the like alone or in combination with a plurality of heat insulating materials. . In addition, since the temperature zone is the same between the ice making chamber 3a and the upper freezing chamber 3b and the lower freezing chamber 4, a partition member 13 that forms a packing receiving surface is provided instead of a heat insulating partition that performs heat insulation. Between the lower freezer compartment 4 and the vegetable compartment 5, the heat insulation partition 14 for partition heat insulation is provided. The heat insulating partition 14 is a heat insulating wall of about 30 to 50 mm, like the heat insulating partition 12. Insulation partitions are basically installed in partitions of rooms with different storage temperature zones such as refrigeration and freezing. The heat insulation partitions 12 and 14 are composed of a polystyrene foam 33 and a vacuum heat insulation panel 50.

  In the heat insulation box 20, the storage compartments of the refrigerator compartment 2, the ice making compartment 3a and the upper freezer compartment 3b, the lower freezer compartment 4, and the vegetable compartment 5 are partitioned from above. Is not particularly limited to this. The refrigerator doors 6a and 6b, the ice making door 7a, the upper freezer compartment door 7b, the lower freezer compartment door 8 and the vegetable compartment door 9 are also particularly limited in terms of opening and closing by rotation, opening and closing by drawer, and the number of divided doors. is not.

  The heat insulating box 20 includes a metal outer box 21 and a synthetic resin inner box 22, and a heat insulating portion is provided in a space formed by the outer box 21 and the inner box 22 to connect each storage chamber and the outside. Insulated. A vacuum heat insulating panel 50 'is arranged along the inside of the outer box 21 or the inner box 22, and a space other than the vacuum heat insulating panel 50' is filled with a foam heat insulating material 23 such as hard urethane foam to form a heat insulating portion. Yes. When generally representing a vacuum heat insulation panel, the code | symbol 50 is used, and when expressing the vacuum heat insulation panel of a specific place, suppose that subscripts, such as an alphabet, are added after the code | symbol 50.

  The outer box 21 is formed in a box shape including a top surface, a bottom surface, both side surfaces, and a back surface by welding a folded steel plate or a flat steel plate. The inner box 22 is formed in a box shape including a top surface, a bottom surface, both side surfaces, and a back surface by molding a synthetic resin plate.

  A cooler 28 is provided on the back side of the ice making chamber 3 a and the freezing chamber 4 in order to cool each room such as the refrigerator compartment 2, the ice making chamber 3 a, the freezing room 4, and the vegetable room 5 to a predetermined temperature. The cooler 28, the compressor 30, the condenser 31, and a capillary tube (not shown) are connected to constitute a refrigeration cycle. Above the cooler 28, a blower 27 that circulates the cool air cooled by the cooler 28 in the refrigerator and maintains a predetermined low temperature is disposed.

  An interior lamp 45 having a case 45a protruding toward the foam heat insulating material 23 is installed on a part of the top surface of the inner box 22, so that the interior when the refrigerator door is opened is bright and easy to see. As the interior lamp 45, an incandescent bulb, a fluorescent lamp, a xenon lamp, or the like is used. Since the thickness of the foam heat insulating material 23 between the case 45a and the outer box 21 is reduced due to the installation of the interior lamp 45, the vacuum heat insulating panel 50a is disposed in this portion to ensure the heat insulating performance. .

  A recessed step portion 40 for accommodating an electrical component 41 such as a control board or a power supply board for controlling the operation of the refrigerator body 1 is formed at the rear part of the top surface of the heat insulating box 20. As a result, the top surface of the outer box 21 exhibits a three-dimensional shape due to the recessed step portion 40. The electrical component 41 is a self-heating component that generates a large amount of heat. The concave step portion 40 is provided with a cover 42 that covers the electrical component 41. The height of the cover 42 is arranged so as to be substantially the same height as the top surface of the outer box 21 in consideration of appearance design and securing the internal volume. When the height of the cover 42 protrudes from the top surface of the outer box, it is desirable to keep it within a range of 10 mm. Since the recessed step portion 40 is in a state where only the space for housing the electrical component 41 is recessed on the side of the foam heat insulating material 23, if the foam heat insulating material 23 is made thick to ensure the heat insulating performance of this portion, the internal volume is sacrificed. turn into. On the contrary, if it is going to secure internal volume, the thickness of the foam heat insulating material 23 between the recessed step part 40 and the inner case 22 will become thin, and heat insulation performance will worsen.

  From these things, the heat insulation performance is strengthened by disposing the vacuum heat insulation panel 50a on the surface of the recessed step portion 40 on the foam heat insulating material 23 side. Specifically, a single three-dimensional vacuum heat insulation panel 50a is installed so that the vacuum heat insulation panel 50a straddles the case 45a of the interior light 45 and the electrical component 41.

  A machine room 15 is formed in the rear part of the bottom surface of the heat insulation box 20 over the entire width. A compressor 30 and a condenser 31 are disposed in the machine room 15. The compressor 30 and the condenser 31 are self-heating components that generate a large amount of heat. Therefore, in order to prevent heat from entering from the machine room 15 into the cabinet, a single three-dimensional vacuum heat insulation panel 50b is arranged on the projection surface toward the inner box 22 side.

  Next, the installation of the vacuum heat insulation panels 50a and 50b will be specifically described with reference to FIGS. 3 is an enlarged view of portion B in FIG. 2, and FIG. 4 is an enlarged view of portion C in FIG.

  As shown in FIG. 3, a meandering heat radiating pipe 60 in contact with the inside of the top surface of the outer box 21 positioned in front of the recessed step portion 40 is installed. The heat radiating pipe 60 is covered with an aluminum tape 60 a and fixed to the outer box 21. Thereby, the heat of the heat radiating pipe 60 is also transferred to the outer box 21 through the aluminum tape 60a.

  The recessed step portion 40 includes an inclined surface that inclines from the rear portion of the top surface of the outer box 21 and sinks backward, and a horizontal bottom surface that extends rearward from the inclined surface. That is, the top surface of the outer box 21 has a three-dimensional shape including a front horizontal plane, an inclined plane, and a rear horizontal plane.

  On the other hand, the vacuum heat insulation panel 50a has a three-dimensional shape formed by bending two steps with substantially the same thickness, and includes a front horizontal part, an inclined part sinking backward from the front horizontal part, and a rear part from the inclined part. A rear horizontal portion extending horizontally. The three-dimensional shape of the vacuum heat insulating panel 50 a substantially matches the three-dimensional shape of the top surface of the outer box 21.

  The vacuum heat insulating panel 50 a is installed so as to straddle the heat radiating pipe 60 and the recessed step portion 40. Specifically, the entire surface of one side of the vacuum heat insulation panel 50a is attached to the top surface of the outer box 21 via an adhesive member 62 having flexibility and heat insulation. As a result, the heat of the heat radiating pipe 60 is not directly transferred to the vacuum heat insulating panel 50a, so that the heat insulating performance of the vacuum heat insulating panel 50a due to the heat of the heat radiating pipe 60 is suppressed over time, and the heat insulating performance can be maintained for a long time. it can. In this embodiment, a sheet material made of polyethylene foam with a double-sided pressure-sensitive adhesive is used as the adhesive member 62, so that the vacuum heat insulating panel 50 a can be easily installed while closing the gap between the heat radiating pipes 60.

  As described above, since heat insulation is performed by the single vacuum heat insulation panel 50a across the radiating pipe 60 and the recessed step portion 40 in which the electric component 41 is disposed, in a portion where the self-heating component is disposed with a simple configuration. The heat insulation performance can be remarkably improved.

  Moreover, since it heat-insulates by the vacuum heat insulation panel 50a in the part close | similar to the high temperature part side, the heat leak from the heat radiating pipe 60 and the electrical component 41 to the store | warehouse | chamber can be reduced further.

  As shown in FIG. 4, a machine room 15 in which a compressor 30 and a condenser 31 are arranged is provided at the rear of the bottom surface of the heat insulating box 20. Due to the formation of the machine room 15, the bottom surface of the heat insulation box 20 includes a front horizontal portion, an inclined portion that rises rearward from the front horizontal portion, and a rear horizontal portion that extends horizontally backward from the inclined portion. It has a three-dimensional shape. Therefore, the bottom surfaces of the outer box 21 and the inner box 22 have a three-dimensional shape including a front horizontal part, an inclined part that rises rearward from the front horizontal part, and a rear horizontal part that extends horizontally backward from the inclined part. ing.

  On the other hand, the vacuum heat insulating panel 50b has a three-dimensional shape that is formed by two-stage bending with substantially the same thickness, and includes a front horizontal portion, an inclined portion that rises rearward from the front horizontal portion, and a horizontal portion that extends backward from the inclined portion. And a rear horizontal portion extending in the direction. The three-dimensional shape of the vacuum heat insulating panel 50 substantially matches the three-dimensional shape of the bottom surface of the inner box 22.

  Since this vacuum heat insulation panel 50b is installed so as to straddle the front horizontal portion, the inclined portion and the rear horizontal portion of the inner box 22, the heat insulation performance can be remarkably improved with a simple configuration, and the compressor Heat leakage from 30 and the condenser 31 to the interior can be reliably reduced.

  As described above, the cooler 28 is provided in the back of the interior located directly above the machine room 15, and the three-dimensional vacuum heat insulation panel 50 b is interposed between the cooler 28, the compressor 30 and the condenser 31. Are arranged as follows. Thus, the vacuum heat insulation panel 50b arrange | positioned between the cooler 28 with the lowest temperature and the compressor 30 with the highest temperature is made into a three-dimensional shape, and the compressor 30 whose one end is a heat generating part and Since the position is away from the condenser 31, the influence of the heat bridge can be reduced. In addition, the vacuum heat insulation panel 50b located between the compressor 30 and the cooler 28 is provided with a notch for escaping a drain pipe (not shown). The presence or absence of this notch or its shape is not particularly limited.

  A part of the inner box side projection surface of the machine room 15 is provided with an internal temperature detection means (internal temperature detection sensor) 48 for detecting the internal temperature. This internal temperature detecting means 48 is housed in a protruding portion 48a formed by protruding the inner box 22 toward the foam heat insulating material 23 in order to eliminate the protrusion into the internal space. For this reason, the vacuum heat insulation panel 50b forms and coats the concavo-convex shape according to the shape of the protruding portion 48a. That is, the vacuum heat insulating panel 50b has a concave and convex shape in which a pair of dents and bulges are formed on the front and back surfaces in the plate thickness direction, and the plate thickness between the dents and the bulges is substantially the same as the other parts. The protruding portion 48a is housed in the concave and convex portion.

  Note that the vacuum heat insulating panel 50a on the top surface portion shown in FIG. 3 is obtained by performing bending twice using a bending jig to obtain a substantially Z shape. The vacuum heat insulating panel 50b in the bottom surface portion shown in FIG. 4 is obtained by processing a concavo-convex shape by a drawing press and obtaining a substantially Z shape by a bending jig.

  Next, a refrigerator according to another embodiment of the present invention will be described with reference to FIG. FIG. 5 is a perspective view for explaining an assembled state of a vacuum heat insulation panel of a refrigerator according to still another embodiment of the present invention. Although this embodiment is different from the above-described embodiment in the points described below, the other points are basically the same as those in the above-described embodiment, and thus redundant description is omitted.

  The refrigerator main body 1 of this embodiment is a vacuum heat insulation panel 50a, 50b, 50c having a three-dimensional shape or a notch in a part of the core material on each of the top surface, both side surfaces, the back surface, and the bottom surface of the heat insulation box 20. , 50 g are arranged. The same vacuum insulation panel 50a as used in the previous embodiment is used on the top surface, a pentagonal plate-like vacuum insulation panel 50g in which one corner portion of the core material is chamfered on the side surface, and the outer plate back surface on the back surface. The vacuum heat insulation panel 50c was bent into a substantially U shape along the shape of 21b, and the same vacuum heat insulation panel 50b as used in the second embodiment was used on the bottom surface.

  By these, the core material area of all the vacuum heat insulation panels arrange | positioned on each surface of the heat insulation box 20 can be enlarged. In the fifth embodiment, the power consumption can be reduced by about 6% compared to the first embodiment.

The configuration according to the above-described embodiment is summarized as follows.
(1) A heat insulating layer is formed by combining a vacuum heat insulating panel (VIP; a hollow body having a vacuum layer) and a heat insulating box (a heat insulating material arranged in a space formed by an outer box and an inner box).
(2) There are multiple types of vacuum heat insulation panels, and these are arranged inside the heat insulation box to form a heat insulation layer, or a plurality of vacuum heat insulation panels are arranged on the outer surface of the heat insulation box to form a heat insulation layer To do. The inside of the heat insulation box is filled with hard urethane foam.
(3) At least one of the vacuum heat insulating panels has a bent structure, and a portion difficult to be filled with urethane foam such as a bent portion or a narrow portion is formed in the heat insulating box surrounding the vacuum heat insulating panel. obtain.
(4) A three-dimensional vacuum heat insulation panel is arranged along the shape of the outer box or the inner box on the top, back, and bottom of the outer box, and the side surface has a rectangular plate shape, a notch shape, and a three-dimensional shape. If one of the vacuum insulation panels is placed, it will be possible to place it in a three-dimensional shape or notch shape, etc. even on the part where the vacuum insulation panel could not be placed due to the placement of parts etc. Performance can be improved dramatically.

  Next, the premix polyol used in the present invention and the rigid urethane foam obtained using the same will be described.

  The fluidity of urethane foam can be adjusted by controlling the reactivity of premix polyol (polyol, catalyst, foam stabilizer, foaming agent) and isocyanate, which are raw materials of urethane foam, and as a result, the narrowness of the heat insulation box It is possible to form a rigid urethane foam sufficiently filled in the space. If the reactivity of the premix polyol and isocyanate mixture is too fast, the reaction will be completed before it sufficiently flows into the narrow space of the heat insulation box, and the space of the heat insulation box cannot be sufficiently filled with the rigid urethane foam. As a result, a heat insulation box with insufficient heat insulation is obtained, and those having too low reactivity are filled with urethane foam more than necessary, which is uneconomical.

  When the ratio of the IR intensity A1 derived from the urethane bond and the IR intensity A2 derived from the urea bond of the rigid urethane foam obtained by using the premix polyol with such reactivity adjusted is found to be within a certain range. I understood. That is, A1 / A2 is in the range of 1.2 to 1.7, and it was found that this hard polyurethane has low thermal conductivity, a small dimensional change rate, and a small amount of heat leakage as a heat insulating box of the refrigerator. It is a feature of the rigid polyurethane foam of the present invention that these characteristics are in a well-balanced range as a whole. According to the embodiment of the present invention, the rigid urethane foam has a bending strength of 0.3 MPa or more, a thermal conductivity of 18.8 mW / m · K or less, a dimensional change rate of less than 2% in absolute value, and a heat insulating box. As a result, the amount of heat leakage is 81.2 W or less.

  In FIG. 8, the IR intensity A1 derived from the urethane bond of the rigid urethane foam and the IR intensity A2 derived from the urea bond are shown. In the case of FIG. 8, A1 is about 1.35 and A2 is about 0.09, so A1 / A2 is 1.5. Here, the conventional method is a conventional method known to the applicant and does not mean that it is known per se.

  The rigid urethane foam is formed by the reaction of a premix polyol and an isocyanate, and the reaction at that time can be mainly classified into the following three. Reaction that forms urea bond with carbon dioxide by reaction of isocyanate and water (foaming reaction), formation reaction of urethane bond by reaction of isocyanate and polyol (resinification reaction), and generation of nurate by dimerization and trimerization of isocyanate Reaction (nulation reaction).

  In order to improve the fluidity of the urethane foam, it is necessary to slow down the resinification reaction without changing the foaming reaction and the nurating reaction rate. That is, by slowing the resinification reaction, the time (gel time (GT)) during which the fluidity of the urethane foam is lost can be delayed. In this case, if the foaming reaction (foaming start time (cream time (C.T.))) is delayed, foaming occurs after the urethane raw material is filled more than necessary in the narrow part inside the heat insulating box. The urethane will be filled more than necessary.

  FIG. 11 is a urethane formation reaction diagram comparing the gel time and cream time of the premix polyol for the present invention and the conventional method. In the case of the present invention, the gel time is reduced by the cream time ratio compared to the conventional method, thereby suppressing the resinification reaction and improving the urethane raw material fluidity. Can be filled well.

  Here, the conventional method is a conventional method known to the applicant and does not mean that it is known per se.

  Specifically, the gel time / cream time in a premix polyol containing a polyol, a catalyst, water, cyclopentane, and a foam stabilizer when the isocyanate equivalent is set to 1 is 5.5-9. is required.

The gel time / cream time in the reaction of this premix polyol and isocyanate is characterized by the infrared absorption spectrum of the rigid urethane foam formed. That is, the formed urethane foam has a urethane bond and a urea bond, and the ratio of the urethane bond to the urea bond is the spectrum intensity derived from the urethane bond at 1700 to 1720 cm ⁻¹ in the infrared absorption spectrum and the urea at 1590 to 1610 cm ⁻¹ . It can be confirmed by the spectrum peak intensity derived from the bond.

Specifically, the inside of the foam within 120 days after foaming was sampled and measured by FT-IR (ATR method (total reflection absorption infrared spectroscopy)). Absorbance derived from urethane bonds of 1700 to 1720 cm ⁻¹ ( logIo / I) A rigid polyurethane foam characterized in that the peak A1 and the absorbance peak A2 derived from the urea bond at 1590 to 1610 cm ⁻¹ have A1 / A2 of 1.7 to 1.2.

At this time, in the premix polyol containing a polyol, a catalyst, water, cyclopentane, and a foam stabilizer, the gel time / when the polyisocyanate was reacted with an isocyanate equivalent of 1 by the catalyst without changing the amount of water. When the cream time is adjusted to greater than 9, in the formed urethane foam, the peak A1 and 1590~1610cm peak A2 from urea bond of ^-1 from urethane bond 1700～1720Cm ^-1 in the infrared absorption spectrum A1 / A2 Becomes less than 1.2, the urea bond to the urethane bond increases, and the strength of the urethane foam decreases.

In contrast, in a premix polyol composed of a polyol, a catalyst, water, cyclopentane, and a foam stabilizer, the gel time when the polyisocyanate was reacted with an isocyanate equivalent of 1 by the catalyst without changing the amount of water. / When cream time is adjusted to less than 5.5, the formed urethane foam, a peak derived from urea bond peaks A1 and 1590～1610Cm ^-1 from urethane bond 1700～1720Cm ^-1 in the infrared absorption spectrum A2 However, A1 / A2 exceeds 1.7, and in the formed urethane foam, the urea bond with respect to the urethane bond is reduced, the fluidity of the urethane foam raw material is poor, and the heat insulation of the formed heat insulation box is deteriorated.

  The premix polyol used in the present invention includes a polyol, a catalyst, a foam stabilizer and a foaming agent. The gel time / cream time when the premix polyol and isocyanate are reacted with an isocyanate equivalent of 1 relative to the polyol and water can be changed depending on the kind of polyol in the premix and the catalyst.

  Polyols that can be used include polyhydric alcohols having 4 to 8 active hydrogen groups and / or 30 to 80% of a compound obtained by adding an alkylene oxide to a polyamine. Here, the proportion of the polyol having 4 to 8 active hydrogen groups and / or a mixture containing one or more compounds obtained by adding an alkylene oxide to a polyamine is less than 30%, and the proportion of polyol having a low crosslinking point is If it increases, the IR strength of the resulting urethane will decrease.

  Moreover, when the mixture containing one or two or more compounds obtained by adding an alkylene oxide to a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a polyamine exceeds 80%, the thermal conductivity of the resulting urethane increases. End up.

  The polyol that can be used in the present invention contains 30 to 80% of a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a compound obtained by adding an alkylene oxide to a polyamine. Compounds having 4 to 8 active hydrogen groups and / or polyamines with alkylene oxide added include polyols with aromatic or heterocyclic rings or compounds with alkylene oxide added to polyamines, aliphatic or aliphatic rings. The compound which added the alkylene oxide to the polyol or polyamine which has can be used.

  The polyol that can be used in the present invention includes 30 to 80% of a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a compound obtained by adding an alkylene oxide to a polyamine, and preferably 4 to 8 active hydrogen groups. In a compound in which alkylene oxide is added to one polyhydric alcohol and / or polyamine, an alkylene oxide is added to a polyhydric alcohol having 4 to 8 active hydrogen groups compared to a compound obtained by adding alkylene oxide to a polyamine having 4 to 8 active hydrogen groups. It is desirable that the compound to which the oxide is added is contained twice or more. In general, a compound in which an alkylene oxide is added to a polyamine is more reactive with a polyisocyanate than a compound in which an alkylene oxide is added to a polyhydric alcohol, and the urethane resinization reaction tends to be faster. When the ratio of the compound in which the alkylene oxide is added to the polyamine increases, the reactivity increases, but the reaction rate can be adjusted by the catalyst to adjust the fluidity. However, adjusting the reactivity by reducing the amount of catalyst or the like adversely affects the bending strength and dimensional stability of the urethane formed.

  Examples of polyhydric alcohols having 4 to 8 active hydrogen groups include diglycerin, pentaerythritol, and methylglucoside as tetravalent alcohols, monosaccharides such as glucose, mannose, and fructose as pentavalent alcohols, dipentaerythritol as hexavalent alcohols, Examples of 7-8 octahydric alcohols such as sorbitol include sugars such as sucrose and lactose and derivatives thereof, and phenols. These may be used alone or in combination of two or more. Desirably, sucrose is most preferable in that a rigid urethane foam having a high crosslinking density and high strength can be obtained.

  As polyamines having 4 to 8 active hydrogen groups, aliphatic polyamines such as ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, ethanolamine, propanolamine, bis (aminomethyl) cyclohexane, dicyclohexylmethanediamine An alicyclic polyamine such as isophorone diamine and norbornane diamine, an araliphatic polyamine such as xylylenediamine and tetramethylxylylenediamine, and an aromatic polyamine such as tolylenediamine and diaminodiphenylmethane can be used.

  As the alkylene oxide added to a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a mixture containing one or more polyamines, ethylene oxide, propylene oxide, butylene oxide and the like can be used. Among these, any 1 type of oxide may be used and 2 or more types of oxides may be used together. When two or more kinds of oxides are used in combination, these may be reacted sequentially, or they may be mixed and reacted.

  Catalysts that can be used in the present invention include a reaction that forms a urea bond with carbon dioxide by the reaction of isocyanate and water (foaming reaction), a urethane bond formation reaction (resinification reaction) by the reaction of isocyanate and polyol, isocyanate It is only necessary that the compound be capable of accelerating each of the formation reaction (nulation reaction) of the nurate bond by dimerization and trimerization. The gel time / cream time is 5 when each catalyst is reacted with polyisocyanate at an isocyanate equivalent of 1 in a premix polyol containing polyol, catalyst, water, cyclopentane, and a foam stabilizer in accordance with the reactivity of the polyol. What is necessary is just to mix | blend so that it may be 0.5-9.

  As the foaming catalyst, for example, pentamethyldiethylenetriamine, bis (dimethylaminoethyl) ether, N, N, N′-trimethylaminoethylethanolamine, N, N-dimethylaminoethoxyethanol or the like can be used. These may be used alone or in combination of two or more.

  Examples of the resinification catalyst include diethylcyclohexylamine, triethylenediamine, N, N, N ′, N′-tetramethylhexanediamine, N, N, N ′, N′-tetramethylpropylenediamine, N, N, N ′, N '-Tetramethylethylenediamine or the like can be used. These may be used alone or in combination of two or more.

  As the nurating catalyst, N, N ″, N ″ -tris (3-dimethylaminopropyl) hexahydro-s-triazine, N, N ′, N ″ -tris (3-diethylaminopropyl) hexahydro-s-triazine or the like is used. These may be used alone or in combination of two or more.

  The urethane foam of the present invention is produced by the vaporization and expansion of cyclopentane coexisting in situ and the carbon dioxide produced by the reaction of isocyanate and water when the polyol and isocyanate react.

  The optimum mixing ratio of water and cyclopentane in the premix polyol of the present invention is 1.4 to 2.0 parts of water and 14.0 to 18.0 parts of cyclopentane with respect to 100 parts by weight of the polyol. The mixing ratio of water and cyclopentane is not limited as long as it is in the above-described range.

  The polyisocyanate used in the present invention is not particularly limited as long as it is a conventionally known polyisocyanate. For example, diphenylmethane diisocyanate (MDI) and its derivatives, these may be used alone or mixed. It can be used. Examples of MDI and its derivatives include a mixture of MDI and its polymer polyphenylpolymethylene diisocyanate, and a diphenylmethane diisocyanate derivative having a terminal isocyanate group.

The urethane foam of the present invention is formed by an ordinary high-pressure foaming machine, and for example, a PU-30 type foaming machine manufactured by Promart can be used. Foaming conditions are a liquid temperature of 18 to 30 ° C., a discharge pressure of 80 to 150 kg / cm ² , a discharge amount of 15 to 30 kg / min, and the temperature of the mold box is around 45 ° C. At this time, since the reactivity (cream time and gel time) of the premix polyol changes depending on the liquid temperature and the temperature of the mold box, in the premix polyol containing polyol, catalyst, water, cyclopentane, and foam stabilizer, It is necessary to adjust the gel time / cream time to be 6 to 8 when the reaction is performed with an isocyanate equivalent to 1 for polyol and water.

The reactivity (cream time and gel time) of the premix polyol of the present invention is obtained by using a normal high pressure foaming machine, and for example, a PU-30 type foaming machine manufactured by Promart can be used. Foaming conditions are a liquid temperature of 22 ° C., a discharge pressure of 100 kg / cm ² , and a mold box temperature measured in the vicinity of 40 ° C.

  Here, the cream time and the gel time are defined as the cream time when the mixed raw material is whitened and foaming starts after mixing of the polyisocyanate component and the polyol component, and the gel time is defined as the time when the needle is inserted into the foam and the yarn is drawn.

〔Example〕
Examples of the present invention will be described below.

Example 1
Hereinafter, the preparation method and the measurement method of the physical property value of Sample 1 will be described.

(1) Preparation of Sample 1 50 parts (parts by weight) of pentaerythritol (polyol A) to which propylene oxide and ethylene oxide are added, 20 parts of triethanolamine-based polyol (polyol D), glycerin-based polyol (polyol E) 20 Using 100 parts by weight of mixed polyol of 10 parts of tolylenediamine (polyol F), 1.8 parts of water, 15.3 parts of cyclopentane, bis (dimethylaminoethyl) ether, triethylenediamine, N, N ′, N ″ -tris (3-diethylaminopropyl) hexahydro-s-triazine mixture 3.0 parts, premix polyol comprising 2.5 parts of foam stabilizer and polymethylene polyphenyl diisocyanate, IR intensity (1700-1720cm ^-1 Ureta The peak A1 derived from the hydrogen bond and the peak A2 derived from the urea bond from 1590 to 1610 cm ⁻¹ A2) The premix polyol composition was adjusted so that A1 / A2 was approximately 1.6, and the urethane foam was thermally insulated using a high-pressure foaming device. The box and the heat insulating door shown in Fig. 7 were filled and foamed to prepare a refrigerator box (sample 1) and a door (sample 2), and a refrigerator was prepared by combining the formed refrigerator box and the refrigerator door. Table 1 shows the physical properties of the rigid urethane foam filled by the four-point injection shown in Fig. 9 and the hard urethane foam formed by the one-point injection method shown in Fig. 9 and the amount of heat leakage of the refrigerator. The agent is a silicone compound represented by the formula (1), and the blending amount is 2.5 parts.

  In Formula (1), x / y = 10-20 and m + n = 20-35 are preferable.

  The physical properties shown in Table 1 were examined as follows.

(I) IR intensity: Measured by FT-IR (ATR method (total reflection absorption infrared spectroscopy)), absorbance (log Io / I) peak A1 from 1700 to 1720 cm ⁻¹ and 1590 to 1610 cm ⁻ A1 / A2 was determined from the absorbance peak A2 derived from ¹ urea bond.

  (Ii) Dimensional change rate (heat insulation box): 150 mm × 300 mm × 20 to 25 mm urethane foam in the urethane foam at position 106 at least 500 mm away from the urethane inlet 102 of the refrigerator heat insulation box in FIG. Thickness dimensional change rate when left at -20 ° C or 70 ° C for 24 hours. In FIG. 6, 100 is a urethane injection head, 102 is a urethane injection port, 103 is a heat insulation box, 104 is an outer box iron plate, 105 is an inner box resin wall, and 106 is a characteristic evaluation sample collection position. Dimensional change rate (heat-insulating door): 150 mm × 300 mm × 20-25 mm urethane foam was left at −20 ° C. or 70 ° C. for 24 hours in urethane foam 50 mm or more away from the side of the outer packaging material of the refrigerator heat insulating door shown in FIG. It is the thickness dimensional change rate.

  FIG. 9 shows a schematic diagram of filling a rigid urethane foam into a door body by one-point injection. An outer box (door plate) 202 made of a steel plate having a polyurethane injection gap and an inner box (door liner) 201 made of a molded product of ABS resin. A heat insulator molded from the above is prepared and temperature-controlled in advance. After that, in the case of a door body, set the foamed jigs 205a and 205b so that the outer box (door plate) 202 is on the lower side and the inner box (door liner) 201 is on the upper side, and a predetermined amount of the rigid urethane foam 203 is used as a gap. inject. Similarly, in the case of a box, set it in a foam jig that has been temperature-controlled in advance so that the entire surface of the box is on the bottom and the back of the box is on the top, and inject a specified amount of rigid urethane foam into the gap. . At that time, the active hydrogen group-containing compound of the premix polyol and the isocyanate are chemically reacted and pressurized by the foaming pressure, and the foamed urethane foam is injected into the wall of the refrigerator to form the heat insulation door 200 and the heat insulation box 20.

  10A and 10B are cross-sectional views of the heat insulation box of the refrigerator, and the hard urethane foam 9 is filled in the heat insulation box 7 between the heat insulation box and the vacuum heat insulation layer 8. FIG. 8 is a cross-sectional view of the heat insulating door of the refrigerator, and the hard urethane foam 203 is filled in the heat insulating door 200 having the vacuum heat insulating material 250. As shown in FIG. 10A, when the filling property of the rigid urethane foam is poor, voids 10 are formed inside the heat insulation box and the heat insulation door, and the surface of the vacuum heat insulation panel box is deformed to deteriorate the appearance. On the other hand, when the premix polyol according to the present invention is used, since the fluidity is excellent, the narrow vacuum heat insulation panel is well filled, so that no void is formed.

  (Iii) Thermal conductivity (insulated box): In a urethane foam at least 500 mm away from the urethane inlet, a urethane foam of 200 mm × 200 mm × 20-25 mm was replaced with HC-073 type (heat flow meter) Method, average temperature 10 ° C.). Thermal conductivity (heat insulating door): In the urethane foam 50 mm or more away from the side of the outer packaging material of the refrigerator heat insulating door shown in FIG. 7, a urethane foam of 200 mm × 200 mm × 20 to 25 mm was replaced with HC-073 type manufactured by Eihiro Seiki Co., Ltd. Evaluation was performed using a heat flow meter method, an average temperature of 10 ° C.

  (Iv) Bending strength (insulation box): In urethane foam at least 500 mm away from the urethane inlet, load 80 mm x 250 mm x 20-25 mm urethane foam at a feed rate of 10 mm / min and load when the foam breaks Is divided by the square of the width and thickness of the foam. Bending strength (insulated door): Bending strength: In the urethane foam 50 mm or more away from the side of the outer packaging material of the refrigerator insulated door shown in FIG. 7, a urethane foam of 80 mm × 250 mm × 20-25 mm is loaded at a feed rate of 10 mm / min. It is a value obtained by dividing the load when the foam breaks by the square of the width and thickness of the foam.

  (V) Heat leakage amount of refrigerator: A refrigerator was created using the created refrigerator door and box, and the amount of heat leakage was measured. The amount of heat leakage of the refrigerator was measured as the amount of heat leakage from the interior by setting the temperature condition opposite to the operation state of the refrigerator. Specifically, a temperature condition in which a refrigerator is installed in a thermostatic chamber of −10 ° C. and the heater temperature is set to a predetermined measurement condition (temperature difference) to compare the power consumption and cooling performance of the refrigerator. Measured with

(2) Preparation of samples 3 and 4 Instead of 50 parts of pentaerythritol (polyol A) added with propylene oxide and ethylene oxide, sample 3 was prepared using 50 parts of sucrose (polyol B) added with propylene oxide and ethylene oxide. Using 50 parts of sorbitol (polyol C) to which propylene oxide and ethylene oxide were added, sample 4 was subjected to IR intensity (peaks A1 and 1590 to 1610 cm ⁻¹ derived from urethane bonds of 1700 to 1720 cm ^{−1) in} the same manner as in sample 1. The premix polyol composition and the catalyst composition were adjusted so that the peak A2) A1 / A2 from the urea bond of A was approximately 1.5, and a refrigerator door was prepared and evaluated in the same manner as in Sample 1. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 3 or 4, and the amount of heat leakage was measured.

(Example 2)
(1) Sample 5 Preparation sample 1 and the same method (urea bond derived peak A1 and 1590～1610Cm ^-1 from urethane bond 1700～1720Cm ^-1 peak A2) urethane foam IR intensity at A1 / A2 The catalyst composition and blending amount were adjusted so as to be approximately 1.4, and a refrigerator box was produced. A refrigerator was formed using the refrigerator door formed of sample 1 and the refrigerator door of sample 5, and the amount of heat leakage was measured.

(2) Preparation of Samples 6 and 7 Instead of 50 parts of polyol A, sample 6 was prepared using 50 parts of polyol B, and sample 7 was prepared similarly to sample 5 using 50 parts of polyol C. A refrigerator was formed using the refrigerator door formed of sample 1 and the refrigerator box of sample 5 or 6, and the amount of heat leakage was measured.

(Example 3)
(1) Preparation Sample 1 similar way (from urea bond peaks A1 and 1590～1610Cm ^-1 from urethane bond 1700～1720Cm ^-1 peak A2) urethane foam IR intensity at the sample 8 A1 / A2 The catalyst composition and blending amount were adjusted so as to be approximately 1.2, and a refrigerator box was created. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 8, and the amount of heat leakage was measured.

(2) Preparation of Samples 9 and 10 In place of 50 parts of polyol A, 50 parts of polyol B was used, sample 9 was prepared using 50 parts of polyol C, and sample 10 was prepared in the same manner as sample 8, and evaluated. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 9 or 10, and the amount of heat leakage was measured.

Example 4
Sample 11 was prepared in the same manner as Sample 5 using 100 parts by weight of a mixed polyol of 70 parts of polyol B, 10 parts of polyol D, 10 parts of polyol E, and 10 parts of polyol F. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 11, and the amount of heat leakage was measured.

(Example 5)
Sample 12 was prepared in the same manner as Sample 5, using 100 parts by weight of a mixed polyol of 35 parts of polyol B, 30 parts of polyol D, and 35 parts of polyol E. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 12, and the amount of heat leakage was measured.

(Example 6)
Sample 13 was prepared in the same manner as Sample 1 using 25 parts of polyol A, 15 parts of polyol B, 10 parts by weight of polyol C, 20 parts of polyol D, 20 parts of polyol E, and 10 parts of polyol F. . A refrigerator was formed using the refrigerator door formed of sample 1 and the refrigerator box of sample 13, and the amount of heat leakage was measured.

(Example 7)
Sample 14 was prepared in the same manner as Sample 1 using 35 parts by weight of polyol B, 20 parts of polyol D, 20 parts of polyol E, and 25 parts of polyol F. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 14, and the amount of heat leakage was measured.

In Examples 1 to 5, IR strength of rigid urethane foam formed using a premix polyol having a gel time / cream time of 7.6 to 5.8 (peaks A1 and 1590 derived from urethane bonds of 1700 to 1720 cm ⁻¹ ) 1610 cm ^-1 peak derived from urea bond A2) A1 / A2 is 1.7 to 1.2, all samples have a bending strength of 0.3 MPa or more, and a thermal conductivity of 18 to 19 mW / m · K. It was within the range.

  Sample 3 formed using polyol B is superior in all values of bending strength, thermal conductivity, dimensional stability, and heat leakage compared to sample 1 or 4 formed using polyol A or polyol C. Similarly, sample 6 formed using polyol B is superior in all values of bending strength, thermal conductivity, dimensional stability, and heat leakage compared to sample 5 or 7 formed using polyol A or polyol C. ing. Similarly, in sample 9 formed using polyol B, all values of bending strength, thermal conductivity, and heat leakage amount are superior to those of sample 8 or 10 formed using polyol A or polyol C.

  Among compounds with polyhydric alcohols having 4 to 8 active hydrogen groups and / or addition of alkylene oxide to polyamines, compounds having an aliphatic ring or an aliphatic ring with respect to compounds in which alkylene oxide is added to polyamines having an aromatic ring or heterocyclic ring Compared with Examples 1 to 6 in which a compound obtained by adding an alkylene oxide to a polyol is contained twice or more, a polyhydric alcohol having 4 to 8 active hydrogen groups and / or an aromatic ring in a compound obtained by adding an alkylene oxide to a polyamine In Example 7 in which the compound obtained by adding an alkylene oxide to a polyol having an aliphatic or aliphatic ring is included 1.4 times the compound obtained by adding an alkylene oxide to a polyamine having a heterocyclic ring or a heterocyclic ring, the flexural strength is 0.37 MPa. The low temperature dimensional stability is -1.6, and the high temperature dimensional stability is 1.8. Moreover, the amount of heat leakage is getting worse.

(Comparative Example 1)
A1 / A2 (peak A2 from urea bond 1700～1720Cm ^-1 urethane bond derived peak A1 and 1590~1610cm ^-1) urethane foam IR intensity is approximately 1.8 at the sample by the same procedure for the intermediate 1 Thus, the catalyst composition and the blending amount were adjusted to prepare Sample 15. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 15, and the amount of heat leakage was measured.

  Samples produced in Comparative Example 1 so that A1 / A2 is 1.6 compared with the amount of heat leakage of the refrigerator produced in Samples 1-14 produced with A1 / A2 in the range of 1.2-1.7. In No. 15, the fluidity of the urethane raw material is insufficient, the amount of heat leakage is increased by 1.3 W or more, and the heat insulating performance of the refrigerator is not sufficient.

(Comparative Example 2)
Sample 1 IR intensity of urethane foam in the same manner as (peak A2 of a urea bond derived peak A1 and 1590～1610Cm ^-1 from urethane bond 1700~1720cm ^-1) A1 / A2 to become approximately 1.2 Sample 16 was prepared by adjusting the catalyst composition and blending amount. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 16, and the amount of heat leakage was measured.

  In Samples 1 to 14 produced with A1 / A2 in the range of 1.2 to 1.7, the bending strength of the produced urethane foam was 0.4 MPa or more, whereas in Comparative Example 1, A1 / A2 was 1 In the sample 16 manufactured to be 0.2, the bending strength of the urethane foam is lowered to 0.29 MPa, and the dimensional stability is lowered.

(Comparative Example 3)
Sample 17 was prepared in the same manner as Sample 5 using 100 parts by weight of a mixed polyol of 15 parts of polyol B, 40 parts of polyol D, 35 parts of polyol E, and 10 parts of polyol F. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 16, and the amount of heat leakage was measured.

  In sample 17, which contains less polyol B, the bending strength of the produced urethane foam is reduced to 0.28 MPa and dimensional stability is also reduced as compared to sample 12 (flexural strength 0.44 MPa).

(Comparative Example 4)
Sample 18 was prepared in the same manner as Sample 5, using 100 parts by weight of a mixed polyol of 75 parts of polyol B, 10 parts of polyol D, and 15 parts of polyol F. A refrigerator was formed using the refrigerator door formed of Sample 1 and the refrigerator box of Sample 18, and the amount of heat leakage was measured.

  In the sample 18 in which the blend of polyol B + polyol F is large, the thermal conductivity of the urethane foam produced is larger by 1.3 mW / m · K than the sample 11. The amount of heat leakage of the refrigerator has also increased by 2.4 W, and the heat insulation performance of the refrigerator is not sufficient.

(Example 8)
In place of 50 parts of pentaerythritol (polyol A) added with propylene oxide and ethylene oxide used in forming the refrigerator door in Example 1, 50 parts of sucrose (polyol B) added with propylene oxide and ethylene oxide were used. Sample 19 was treated with 50 parts of sorbitol (polyol C) to which propylene oxide and ethylene oxide were added, and sample 20 was subjected to IR intensity (peaks A1 and 1590 derived from urethane bonds of 1700 to 1720 cm ^{−1) in} the same manner as in sample 1. ˜1610 cm ⁻¹ peak derived from urea bond A2) The premix polyol composition and the catalyst composition were adjusted so that A1 / A2 was approximately 1.4, and a refrigerated door was prepared and evaluated in the same manner as Sample 2. . A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 19 or 20, and the amount of heat leakage was measured.

(I) IR intensity: Measured by FT-IR (ATR method (total reflection absorption infrared spectroscopy)), absorbance (log Io / I) peak A1 from 1700 to 1720 cm ⁻¹ and 1590 to 1610 cm ⁻ A1 / A2 was determined from the absorbance peak A2 derived from ¹ urea bond.

  (Ii) Dimensional stability: When urethane foam of 150 mm × 300 mm × 20 to 25 mm is left at −20 ° C. or 70 ° C. for 24 hours in urethane foam 50 mm or more away from the side of the outer packaging material of the refrigerator heat insulating door shown in FIG. The thickness dimensional change rate.

  (Iii) Thermal conductivity: In the urethane foam 50 mm or more away from the side of the outer packaging material of the refrigerator heat insulating door shown in FIG. 7, a urethane foam of 200 mm × 200 mm × 20 to 25 mm was replaced with HC-073 type (Heat Flow) Evaluation was made using a measuring method, an average temperature of 10 ° C.).

  (Iv) Bending strength: In a urethane foam 50 mm or more away from the side of the outer packaging material of the refrigerator heat insulating door shown in FIG. 7, a urethane foam of 80 mm × 250 mm × 20 to 25 mm is loaded at a feed rate of 10 mm / min. It is a value obtained by dividing the load by the square of the width and thickness of the foam.

  (V) Heat leakage amount of refrigerator: The same raw materials (polyol and isocyanate), catalyst, and foam stabilizer as those of Sample 1 were prepared, and filled by four-point injection shown in FIG. 6 with a high-pressure foaming device to form a refrigerator box. . A refrigerator was formed using the created refrigerator door and box, and the amount of heat leakage was measured. The amount of heat leakage of the refrigerator was measured as the amount of heat leakage from the interior by setting the temperature condition opposite to the operation state of the refrigerator. Specifically, a temperature condition in which a refrigerator is installed in a thermostatic chamber of −10 ° C. and the heater temperature is set to a predetermined measurement condition (temperature difference) to compare the power consumption and cooling performance of the refrigerator. Measured with

Example 9
Sample 21 which is a refrigerator door was produced in the same manner as Sample 2 by using 100 parts by weight of mixed polyol of 70 parts of polyol B, 10 parts of polyol D, 10 parts of polyol E, and 10 parts of polyol F. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 21, and the amount of heat leakage was measured.

(Example 10)
Sample 22 which is a refrigerator door was produced in the same manner as Sample 2 using 35 parts by weight of polyol B, 20 parts of polyol D, 20 parts of polyol E and 25 parts of polyol F. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 22, and the amount of heat leakage was measured.

(Example 11)
In the same manner as Sample 2, using 25 parts of polyol A, 15 parts of polyol B, 10 parts by weight of polyol C, 20 parts of polyol D, 20 parts of polyol E, and 10 parts of polyol F. A sample 23 was produced. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 23, and the amount of heat leakage was measured.

IR intensity of rigid urethane foam (samples 19 to 23) formed using a premix polyol having a gel time / cream time of 7.1 to 6.7 (peaks A1 and 1590 to 1610 cm derived from urethane bonds of 1700 to 1720 cm ^-1 ) ^-1 peak derived from urea bond A2) A1 / A2 is 1.42-1.38, each sample has a bending strength of 0.3 MPa or more, and a thermal conductivity of 18-19 mW / m · K. Was within.
Among compounds with polyhydric alcohols having 4 to 8 active hydrogen groups and / or addition of alkylene oxide to polyamines, compounds having an aliphatic ring or an aliphatic ring with respect to compounds in which alkylene oxide is added to polyamines having an aromatic ring or heterocyclic ring Compared with Examples 8 and 9 in which a compound obtained by adding an alkylene oxide to a polyol is contained twice or more, a polyhydric alcohol having 4 to 8 active hydrogen groups and / or an aromatic ring in a compound obtained by adding an alkylene oxide to a polyamine In Example 10 in which the compound obtained by adding an alkylene oxide to a polyol having an aliphatic or aliphatic ring is included 1.4 times the compound obtained by adding an alkylene oxide to a polyamine having a ring or a heterocyclic ring, the flexural strength is 0.35 MPa. The low temperature dimensional stability is -1.7, and the high temperature dimensional stability is 1.6. Moreover, the amount of heat leakage increases and the heat insulation property is deteriorated.

  Sample 19 formed using polyol B is superior in all values of bending strength, thermal conductivity, dimensional stability, and heat leakage compared to sample 2 or 20 formed using polyol A or polyol C.

(Comparative Example 5)
A1 / A2 (peak A2 from urea bond 1700～1720Cm ^-1 urethane bond derived peak A1 and 1590~1610cm ^-1) urethane foam IR intensity is approximately 1.8 at the sample 2 with the same method Thus, the catalyst composition and the blending amount were adjusted, and a sample 24 as a refrigerator door was produced. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 24, and the amount of heat leakage was measured.

  In sample 2 and samples 19 to 23, which were prepared in the range of A1 / A2 of 1.7 to 1.2, a sample prepared so that A1 / A2 was 1.8 in Comparative Example 5 as compared with the prepared refrigerator. In No. 24, the thermal conductivity is increased by 1.3 mW / m · K or more. Further, the amount of heat leakage is increased by 1.3 W or more, and the heat insulating heat capacity of the refrigerator is not sufficient.

(Comparative Example 6)
IR intensity of the urethane foam in the same manner as Sample 2 (peak A2 from urea bond peaks A1 and 1590～1610Cm ^-1 from urethane bond 1700~1720cm ^-1) to A1 / A2 is approximately 1.1 The catalyst composition and the blending amount were adjusted to prepare a sample 25 that is a refrigerator door. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 25, and the amount of heat leakage was measured.

  In Sample 2 and Samples 19 to 23 produced with A1 / A2 in the range of 1.2 to 1.7, the bending strength of the produced urethane foam was 0.4 MPa or more, whereas in Comparative Example 1, A1 In the sample 25 prepared so that / A2 is 1.2, the bending strength of the urethane foam is reduced to 0.29 MPa, the low temperature dimensional stability is -2.3, and the high temperature dimensional stability is 2.1.

(Comparative Example 7)
Sample 26, which is a refrigerator door, was prepared in the same manner as Sample 20 using 15 parts by weight of polyol B, 40 parts of polyol D, 35 parts of polyol E, and 10 parts of polyol F. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 26, and the amount of heat leakage was measured.

  In sample 26 with a small amount of polyol B and F, compared to sample 2 and samples 19 to 23, the produced urethane foam has a bending strength of 0.28 MPa, a low temperature dimensional stability of -2.2, and a high temperature dimensional stability. It has dropped to 2.5.

(Comparative Example 8)
Sample 27, which is a refrigerator box, was produced in the same manner as Sample 20, using 100 parts by weight of a mixed polyol of 75 parts of polyol B, 10 parts of polyol D, and 15 parts of polyol E. A refrigerator was formed using the refrigerator box formed of sample 1 and the refrigerator door of sample 27, and the amount of heat leakage was measured.

  In the sample 27 in which the blend of polyol B + polyol F is large, the thermal conductivity of the urethane foam produced is larger than that of the sample 20 by 1.3 mW / m · K. Further, the amount of heat leakage is increased by 2 W, and the heat insulating heat capacity of the refrigerator is not sufficient.

  The present invention can be applied to a heat insulating box of a refrigerator filled with hard polyurethane.

DESCRIPTION OF SYMBOLS 1 Refrigerator main body 50a, 50b Vacuum heat insulation panel 100 Urethane injection head 102 Urethane injection port 103 Heat insulation box 104 Outer box iron plate 105 Inner box resin wall 106 Urethane foam sample collection position 107 Box 108 Vacuum layer 109 Urethane foam 110 Void

Claims (18)

It contains cyclopentane as a blowing agent, has a thermal conductivity at 10 ° C. of 18.0 to 19.0 mW / m · K, a bending strength of 0.3 MPa or more, and an infrared absorption spectrum peak intensity of 1700 to 1720 cm ^−1. A rigid urethane foam, wherein A1 / A2 is 1.2 to 1.7 when the infrared absorption spectrum peak intensity of A1, 1590 to 1610 cm ^-1 is represented by A2.   2. The rigid urethane foam according to claim 1, comprising 30 to 80 wt% of a compound obtained by adding an alkylene oxide to a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a polyamine.   The rigid urethane foam according to claim 1, wherein the bending strength of the rigid urethane foam is 0.3 MPa or more and the dimensional change rate is less than 2% in absolute value.   A heat insulating box body for a refrigerator, wherein the rigid urethane foam according to any one of claims 1 to 3 is filled in a space formed between an outer box and an inner box of the refrigerator.   A heat insulating door for a refrigerator, wherein the hard urethane foam according to any one of claims 1 to 3 is filled in an outer door front iron plate of the refrigerator and an inner door wall space.   A premix polyol containing a polyol, a catalyst, water, cyclopentane, and a foam stabilizer, and adjusting a blending amount of the polyol, catalyst, water, cyclopentane, and the foam stabilizer, Ratio of loss of fluidity of the urethane foam (gel time; GT) and foaming reaction (time for foaming to start; cream time (C.T.)) when the isocyanate equivalent to water is 1 A premix polyol for producing rigid urethane foam, characterized in that it is a mixed solution having a gel time / cream time of 5.5 to 9.   The premix polyol for producing rigid urethane foam according to claim 6, wherein the rigid urethane foam has a bending strength of 0.3 MPa or more and a dimensional change rate of less than 2% in absolute value.   The premix polyol for producing rigid urethane foam according to claim 6, wherein the bending strength of a refrigerator having a rigid urethane foam formed using the premix polyol is 0.3 MPa or more.   The premix polyol according to claim 6, wherein the polyol contains 30 to 80 wt% of a compound obtained by adding an alkylene oxide to a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a polyamine. .   A premix polyol, wherein the polyol is a compound in which an alkylene oxide is added to sucrose in a polyhydric alcohol having 4 to 8 active hydrogen groups to which an alkylene oxide is added according to claim 6.   A heat insulation box for a refrigerator, which is formed by filling a space formed between an outer box and an inner box of a refrigerator with the rigid urethane foam formed by reacting the premix polyol and isocyanate according to claim 6 or 7.   A heat insulating door for a refrigerator, comprising: a hard urethane foam formed by reacting the premix polyol and isocyanate according to claim 6 or 7 in a front iron plate of the refrigerator and an inner door wall space.   A polyol, a catalyst, water, cyclopentane, and a foam stabilizer premix polyol are prepared, and a blending amount of the polyol, catalyst, water, cyclopentane, and foam stabilizer is adjusted, and a polyisocyanate is added to the polyol and the water. This is the ratio between the time (gel time; GT) when the urethane foam loses fluidity when reacted with an isocyanate equivalent of 1 and the foaming reaction (time when foaming starts; cream time (C.T.)). A method for producing a rigid urethane foam, comprising preparing a mixed solution having a gel time / cream time of 5.5 to 9, mixing it with an isocyanate, supplying the mixture into a mold, and reacting the mixture.   The method for producing a rigid urethane foam according to claim 11, wherein the premix polyol is adjusted so that the bending strength of the rigid urethane foam is 0.3 MPa or more and the dimensional change rate is less than 2% in absolute value. . In a refrigerator having a heat insulation layer composed of a heat insulation box having a rigid urethane foam filled in a space formed by an outer box and an inner box, and a plurality of vacuum heat insulation panels arranged in contact with the heat insulation box ,
The rigid urethane foam has a thermal conductivity of 18 to 19 mW / mK at an average temperature of 10 ° C. and 70 ° C. in air at an average temperature of 10 to 25 mm from a plane portion at least 500 mm away from the urethane inlet. Rigidity characterized in that the dimensional change rate after standing for 24 hours at a temperature of -20 ° C is 2% or less in absolute value, and the bending strength of rigid urethane foam at least 500 mm away from the urethane inlet is 0.4 MPa or more. A refrigerator characterized by being a polyurethane foam. A refrigerator having a plurality of heat insulating boxes each having a plurality of vacuum heat insulating panels disposed in a space formed by the outer box and the inner box and along the outer box or the inner box and filled with rigid urethane foam in the space. In
In a premix polyol composition containing a polyol, a foam stabilizer, a catalyst, water and cyclopentane, the polyol is a compound obtained by adding an alkylene oxide to a polyhydric alcohol having 4 to 8 hydroxyl groups with respect to the polyol component. A premix polyol composition containing 80% by weight is foamed in a heat insulating box, and 70 ° C. and −20 in air of a core layer heat insulating material having a thickness of about 20 to 25 mm from a plane portion at least 500 mm away from the urethane inlet. Rigid polyurethane foam characterized in that the dimensional change rate after standing for 24 hours at a temperature of 2 ° C. is 2% or less in absolute value and the bending strength of rigid urethane foam at least 500 mm away from the urethane inlet is 0.4 MPa or more. . In a refrigerator having a heat insulating door having a hard urethane foam filled in a space formed by an outer door front iron plate and an inner door wall,
Dimensional change rate of the rigid urethane foam when left at 70 ° C. and −20 ° C. for 24 hours in the air of the core layer heat insulating material having a thickness of about 20 to 25 mm away from the side of the outer packaging material of the refrigerator heat insulating door. A refrigerator characterized in that the bending strength of rigid urethane foam at an absolute value of 2% or less and at least 50 mm or more away from the side of the outer packaging material of the refrigerator heat insulating door is 0.4 MPa or more. In a refrigerator having a heat insulating door having a hard urethane foam filled in a space formed by an outer door front iron plate and an inner door wall,
In the premix polyol composition containing a polyol, a foam stabilizer, a catalyst, water and cyclopentane, the polyol is a polyhydric alcohol having 4 to 8 active hydrogen groups and / or a compound obtained by adding an alkylene oxide to a polyamine. On the other hand, the premix polyol composition containing 30 to 80% by weight is foamed in the heat insulating box, and the core layer heat insulating material having a thickness of about 20 to 25 mm away from the side of the outer packaging material of the refrigerator heat insulating door is in the air. The dimensional change rate after standing for 24 hours at temperatures of 70 ° C and -20 ° C is 2% or less in absolute value, and the bending strength of rigid urethane foam at least 50mm away from the side of the outer packaging material of the refrigerator heat insulation door is 0.4MPa or more. The refrigerator characterized by being.