JP6909738B2 - refrigerator - Google Patents

Description

Regarding the refrigerator.

In recent years, refrigerators have been made thinner in their housings in order to meet the needs of consumers with larger capacities. Thinning the wall of the housing has a trade-off relationship with the heat insulating performance because the heat insulating thickness is reduced. Therefore, studies are being conducted to reduce energy consumption even if the wall is thinned by designing such as adding cooling function members and increasing the thickness of the vacuum heat insulating material. Further, since there is a concern that the strength of the thin-walled housing may decrease due to the thin-walled housing, it is desired to improve the strength of the rigid urethane foam alone in addition to the structural design. For example, Patent Document 1 describes that the strength of the box body is improved by increasing the density (60 kg / m3 or more) of the rigid urethane foam in the thin portion in the refrigerator housing.

Japanese Patent No. 6140279

However, in Patent Document 1, since the space in which the hard urethane foam raw material flows is as narrow as less than 10 mm, it is not easy to fill the hard urethane foam without an unfilled portion. Since the unfilled portion of the rigid urethane foam lowers the heat insulating performance of the entire refrigerator, the amount of heat leakage of the refrigerator increases. Further, when an unfilled portion is generated in the housing, not only the distortion deformation that is concave in the direction of the unfilled portion occurs and the appearance is poor, but also when the rigid urethane foam is not sufficiently filled and the density is biased. It causes the partial shrinkage of the rigid urethane foam and causes a poor appearance.

Therefore, an object of the present invention is to suppress deterioration of heat insulating performance and appearance quality even when the wall of the refrigerator is thinned.

The present invention comprises an outer box, an inner box, a vacuum heat insulating material arranged between the outer box and the inner box, and a rigid urethane foam foam-filled between the outer box and the inner box. In the refrigerator provided with, the region where the thickness of the rigid urethane foam is 10 mm or less has a premix polyol composition containing an active hydrogen-containing compound, a foam stabilizer, a catalyst, water, and cyclopentane. The active hydrogen-containing compound includes a first active hydrogen-containing compound (A), a second active hydrogen-containing compound (B), and a third active hydrogen-containing compound (C). The first active hydrogen-containing compound (A) is an active hydrogen-containing chain aliphatic compound having a weight average molecular weight of 200 or less, and the second active hydrogen-containing compound (B) contains 4 to 8 active hydrogens. The third active hydrogen-containing compound (C) is an active hydrogen-containing compound obtained by adding a polyhydric alcohol to a carboxylic acid and is an aromatic polyester polyol, which serves as the catalyst. , A cyclic amine compound, a salt of the cyclic amine compound, or a carboxylate.

According to the present invention, the fluidity of the hard urethane foam raw material is dramatically improved, and even when the refrigerator is made thinner, deterioration of heat insulating performance and appearance quality can be suppressed.

It is a front view of the refrigerator equipped with a door. It is a front view of the refrigerator excluding the door. It is a side sectional view of a refrigerator. It is an enlarged view of the side rail part of the refrigerator of FIG. It is an enlarged view of the foam insulation arrangement position (rail part) of FIG. It is sectional drawing parallel to the foaming direction of the rigid urethane foam of this embodiment. It is sectional drawing which is perpendicular to the foaming direction of the rigid urethane foam of this embodiment.

The refrigerator 1 of the present embodiment has an inner box 13, an outer box 14, and a vacuum heat insulating material 20 arranged between the inner box 13 and the outer box 14. In the present embodiment, the vacuum heat insulating material 20 is arranged on the outer box 14 side via an adhesive such as double-sided tape or hot melt, and the gap between the vacuum heat insulating material 20 and the inner box 13 is a urethane heat insulating material. 19 is injected and foamed, and is adhered to or fixed to the inner box 13. The vacuum heat insulating material 20 may be arranged on the inner box 13 side or between the inner box 13 and the outer box 14. In such a case, the gap between the vacuum heat insulating material 20 and the outer box 14 or the gap between the vacuum heat insulating material 20 or the outer box 14 may be arranged. The urethane heat insulating material 19 is filled in the gap between the vacuum heat insulating material 20 and the inner box 13 and the gap between the vacuum heat insulating material 20 and the outer box 14. The heat insulating performance of the heat insulating box 2 is borne by the urethane heat insulating material 19 and the vacuum heat insulating material 20, and in particular, from the viewpoint of the heat insulating performance, the filling ratio of the vacuum heat insulating material 20 having about 10 times the heat insulating performance of the urethane heat insulating material. It is desirable to increase.

However, the vacuum heat insulating material is expensive, and if the required performance is obtained, the filling ratio of the vacuum heat insulating material may be reduced. Here, the filling ratio of the vacuum heat insulating material refers to the ratio of the vacuum heat insulating material 20 in the space formed from the inner box 13 and the outer box 14, and is (volume of the vacuum heat insulating material) / (vacuum heat insulating material). It is calculated by the formula of (volume of vacuum heat insulating material + volume of urethane heat insulating material). The filling ratio of the vacuum heat insulating material in the refrigerator 1 of the present embodiment is 30% or more 80 in the heat insulating space including the top surface, the back surface, both side surfaces, the bottom surface of the refrigerator 1 and the partition plate 5 of the storage chamber 6. % Or less.

As shown in FIGS. 1 and 2, the refrigerator 1 is mainly composed of a heat insulating box 2 and each door, and the heat insulating box 2 has one or more storage chambers 6 open to the front. When there are two or more storage chambers 6, each storage chamber 6 is partitioned by a partition plate 5, and the storage chamber 6 is provided with a rotary door 3 or a pull-out door 4 provided with a case 15. It is installed.

FIG. 3 shows a side sectional view of the refrigerator 1. The case 15 stored in the storage chamber 6 is pulled out together with the pull-out door 4. In the present embodiment, the lowermost storage room 6 assuming a vegetable room formed in front of the machine room 8 will be described, but a freezing room may be assumed and the upper storage room may be used. .. Further, a rail 12 as shown in FIG. 4 is provided on the side wall of the storage chamber 6, and a pull-out door 4 is pulled out while sliding in the front-rear direction via the rail 12.

FIG. 5 is a cross-sectional view showing the structure of the side wall in the portion where the rail 12 is provided. As shown in FIG. 5, the rail 12 includes a rail member 16 attached to the side of the case 15, a pull-out door 4 via the rail member 16, and a rail support member that supports the load of food in the case 15. It is formed of 17 and a rail reinforcing member 10 that improves the strength when the rail support member 17 is attached to the inner box 13. The inner box 13, the rail support member 17, and the rail reinforcing member 10 are mainly fixed by screws 11. For the rail reinforcing member 10, a metal having a thickness of 1 mm or more and less than 10 mm, a thermosetting plastic, or the like is used.

Here, a concave portion is formed inside the inner box 13 so as to house the rail support member 17, while a convex portion is formed on the outside of the inner box 13 toward the vacuum heat insulating material 20 side. Therefore, in the portion of the inner box 13 where the rail 12 is located, the distance between the inner box 12 and the vacuum heat insulating material 20 is closer than in the other portions. Further, since the rail reinforcing member 10 is further present on the outside of the inner box 13 in this portion, the gap between the rail reinforcing member 10 and the vacuum heat insulating material 20 is narrow. In particular, the gap between the inner box 13 and the vacuum heat insulating material 20 is further narrowed at the place where the fixing member such as the screw 11 protruding from the inner box 13 toward the vacuum heat insulating material 20 is present. The fixing members of the inner box 13, the rail supporting member 17, and the rail reinforcing member 10 include, in addition to the screws 11, claws provided on the rail supporting member 17 and supporting the rail reinforcing member 10 by a hooking and fixing structure. Is done.

As described above, among the side walls formed by the inner box 13 and the outer box 14, the portion where the rail 12 exists requires a structure for fixing the rail 12 to the inner box 13, so that the inner box 13 or The gap between the structure provided on the outside of the inner box 13 and the vacuum heat insulating material 20 is narrower than that of the other parts, and the gap is locally less than 10 mm. Moreover, the vacuum heat insulating material 20 itself has variations in thickness, warpage, and surface unevenness, and there are also manufacturing variations when the vacuum heat insulating material 20 is attached to the outer box 14. As a result, the inner box 13 or the structure provided on the outside of the inner box 13 comes into contact with the vacuum heat insulating material 20, and the outer packaging material of the vacuum heat insulating material is cracked or torn, which reduces productivity or slow leaks. There is a possibility that the heat insulating performance will be reduced.

Therefore, in this embodiment, in the region where the gap with the vacuum heat insulating material 20 is less than 10 mm, specifically, as shown in FIG. 5, on the outside of the inner box 13 in the portion where the rail support member 17 is located inside. , A urethane material having the following premix polyol was injected and foamed to obtain a rigid urethane foam.

The premix polyol of the present embodiment is a premix polyol composition containing an active hydrogen-containing compound, a foam stabilizer, a catalyst, water, and cyclopentane, and the active hydrogen-containing compound is a first active hydrogen-containing compound. It contains at least one (A), a second active hydrogen-containing compound (B), and a third active hydrogen-containing compound (C). Here, the first active hydrogen-containing compound (A) is alkylene to an active hydrogen-containing chain aliphatic compound having a weight average molecular weight of 200 or less, or an active hydrogen-containing chain aliphatic compound having a weight average molecular weight of 200 or less. It is a compound to which oxide is added. The second active hydrogen-containing compound (B) is an active hydrogen-containing compound obtained by adding an alkylene oxide to a compound having 4 to 8 active hydrogens. Further, the third active hydrogen-containing compound (C) is an active hydrogen-containing compound obtained by adding a polyhydric alcohol to a monovalent carboxylic acid or a polyvalent carboxylic acid. The catalyst component contains any one of a cyclic amine compound, a salt of the cyclic amine compound, and a carboxylate.
By mixing and foaming a premix polyol with such a composition and polyisocyanate, it is possible to make the reaction delayed compared to the normal foaming reaction while maintaining low viscosity, which is a leap forward compared to the past. Therefore, it is possible to provide a rigid urethane foam having high strength and high heat insulating performance.

Specific examples of the first active hydrogen-containing compound (A) of the present embodiment include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, and 1,4-butane. It contains at least one of diol, 1,5-pentanediol, hydrazine, ethylenediamine, hexamethylenediamine, diethanolamine, aminoethylethanolamine, glycerin, triethanolamine, pentaerythritol and triisopropanolamine. Hereinafter, it is referred to as polyol (A). The premix polyol composition of the present embodiment may contain at least one of the above-mentioned polyols (A), and may contain two or more of them.

Here, since the low molecular weight and chain aliphatic polyol (A) has a shorter molecular chain than the polyol having a weight average molecular weight of more than 200, it is derived from polymethylene diisocyanate in the molecular structure after the reaction with polymethylene diisocyanate. It has the effect of further shortening the distance between the aromatic molecular chains of. Further, the urethane bond obtained by reacting and forming a chain aliphatic polyol (A) with polymethylene diisocyanate having a low molecular weight is a urethane bond derived from water molecules (obtained by reaction forming between water and polymethylene diisocyanate) and / Or easily forms a hydrogen bond with a urethane bond. The formation of these hydrogen bonds promotes aggregation between aromatic molecular chains derived from polymethylene diisocyanate, resulting in an effect of improving strength.

Next, the premix polyol composition of the present embodiment has 4 to 4 hydroxyl groups as the second active hydrogen-containing compound (B) (hereinafter referred to as polyol (B)) in addition to the above-mentioned polyol (A). It contains an active hydrogen-containing compound obtained by adding an alkylene oxide to the polyhydric alcohol of 8.

Here, as the polyhydric alcohol having 4 to 8 hydroxyl groups, specifically, if it is a tetrahydric alcohol, it is glycerin, pentaerythritol, methyl glucoside, toluenediamine, etc., and if it is a pentahydric alcohol, it is glucose, mannose, fructose, etc. In the case of monosaccharides and hexahydric alcohols, pentaerythritol, sorbitol and the like can be preferably used, and in the case of 7 to octahydric alcohols, saccharides such as sucrose and lactose and derivatives thereof, phenols and the like can be preferably used. Of these, it is particularly preferable to use sucrose. Sucrose has many cross-linking points, and can improve the strength and dimensional stability of rigid urethane foam.

As the alkylene oxide of the polyol (B), ethylene oxide, propylene oxide, butylene oxide and the like can be preferably used. Of these, any one of the oxides may be used, or two or more kinds of oxides may be used in combination. When two or more kinds of oxides are used in combination, they may be reacted sequentially, or they may be mixed and reacted.

The premix polyol composition of the present embodiment may contain at least one of the above-mentioned polyols (B), and may contain two or more of them.

Polyurethane (B), which has a relatively low viscosity, has many reaction cross-linking points, forms a three-dimensional cross-linked structure, and has a strong molecular structure. Therefore, it is possible to increase the strength of rigid urethane foam while maintaining low viscosity. be. As a result, the strength of the rigid urethane foam can be improved synergistically with the effect of the above-mentioned polyol (A).

Further, in the present embodiment, the third active hydrogen-containing compound (C) (hereinafter referred to as polyester polyol (C)) contains active hydrogen obtained by adding a polyhydric alcohol to a monovalent carboxylic acid or a polyvalent carboxylic acid. Contains compounds. Since the polyester polyol (C) has an appropriately low compatibility with cyclopentane, which is a foaming agent, it is efficiently gasified during the foaming reaction and is effective in reducing the thermal conductivity. Specifically, as the polyester polyol (C) used in the present embodiment, polyester polyols having an aromatic such as phthalic anhydride-based polyester polyol, terephthalic acid-based polyester polyol, and benzoic acid derivative polyester polyol are preferable, and these are preferable. Since it has a rigid aromatic ring, it is also effective in increasing the strength of rigid urethane foam.

Next, the premix polyol composition of the present embodiment contains any one of a cyclic amine compound, a salt of the cyclic amine compound, and a carboxylate as a catalyst component. By using these catalysts, it is possible to prolong the time in the liquid state by delaying the initial foaming reaction and prolong the time in the gel state by delaying the gel time in the middle of the reaction, dramatically improving the fluidity. can. In the reaction of the rigid urethane foam, the liquid mixed with the premix polyol composition and the polyisocyanate changes to cream color at the initial stage of the reaction and the foaming reaction starts. After that, when the cross-linking (gelation) reaction of the resin is started, the viscosity increases, the fluidity decreases, and finally the resin is cured. In order to fill a complicated / narrow space with rigid urethane foam, it is effective to prolong the fluidity time. Since the cyclic amine compound, the salt of the cyclic amine compound, and the carboxylate have a characteristic of having a small catalytic activity in the initial foaming reaction, it is possible to prolong the low viscosity state, that is, the time of having fluidity. The cyclic amine compound has a small catalytic activity for the reaction between water and the polyisocyanate and a large catalytic activity for the cross-linking (gelling) reaction of the resin in the initial reaction between the premix polyol composition of the present embodiment and the polyisocyanate. .. Therefore, the gelation time can be controlled to an arbitrary length by adjusting the addition amount.

Salts and carboxylates of cyclic amine compounds also have a delaying effect. These catalysts exhibit catalytic activity by increasing the temperature of the reaction system and causing salt dissociation. Since it is active in both the initial reaction and the cross-linking (gelling) reaction of the resin, the time until the initial reaction can be lengthened, but the control of the cross-linking (gelling) reaction of the resin is more difficult than that of the cyclic amine compound.

The polyol (A) is preferably contained in an amount of 5 to 10% by mass of the premix polyol composition. In addition, "5 to 10% by mass" means 5% by mass or more and 10% by mass or less. When the polyol (A) is less than 5% by mass of the premix polyol composition, the effect of reducing the viscosity and improving the strength of the premix polyol composition is insufficient, and when it is more than 10% by mass, the viscosity becomes high. If it becomes too small, liquid may leak in the refrigerator during the reaction process of the rigid urethane foam, and the amount of heat leakage may increase.

The polyol (B) is preferably contained in an amount of 70 to 90% by mass of the premix polyol composition. When the polyol (B) is less than 70% by mass of the premix polyol composition, the amount of the polyol component having many reaction cross-linking points decreases, and the strength of the premix polyol composition decreases. If it exceeds 90% by mass, the compatibility between cyclopentane and the premics polyol composition rapidly deteriorates due to the high polarity of the polyol (B), and the amount of cyclopentane volatilized increases, resulting in efficient cells. It becomes impossible to contain cyclopentane inside. As a result, the thermal conductivity increases and the amount of heat leakage increases. The polyol (B) may have many reaction cross-linking points, and its structure is not limited to a chain or an aliphatic like the polyol (A). It may have an aromatic ring.

The polyester polyol (C) is preferably contained in an amount of 5 to 10% by mass of the premix polyol composition. The polyester polyol (C), which has a relatively low viscosity, has an appropriately low compatibility with cyclopentane, which is a foaming agent, and is efficiently gasified during the foaming reaction and is encapsulated in the cell, so that the thermal conductivity is reduced. It is effective in improving fluidity. If the addition amount is less than 5% by mass, the above-mentioned effect cannot be obtained. Since the polyester polyol (C) is synthesized by polycondensation of a carboxylic acid and a polyhydric alcohol (for example, diethylene glycol), it has a primary hydroxyl group having high reactivity with isocyanate. Therefore, when the addition amount exceeds 10% by mass, the reactivity is fast, the gel time in the middle of the initial foaming reaction and the reaction is fast, and the fluidity is lowered.

The monovalent carboxylic acid or polyvalent carboxylic acid is characterized by being one or more of succinic acid, adipic acid, sebacic acid, aromatic mono-substituted carboxylic acid derivative, and aromatic di-substituted carboxylic acid derivative. In particular, polyester polyols having fragrances such as phthalate ester-based polyester polyols, terephthalic acid-based polyester polyols, and benzoic acid-based polyester polyols are preferable in terms of both improving strength and reducing thermal conductivity.

The premix polyol composition of the present embodiment contains any of a cyclic amine compound, a salt of the cyclic amine compound, and a carboxylate in an amount of 0.5 to 1.5% by mass of the premix polyol composition. By reacting such a premix polyol with polyisosinate, the time in the liquid state is prolonged by delaying the initial foaming reaction, and the time in the gel state is prolonged by delaying the gel time in the middle of the reaction. It is possible to fill the heat insulating housing having a complicated shape with rigid urethane foam without any unfilled portion. In the case of the thin-walled refrigerator, it is preferable that the bending strength of the rigid urethane foam is 0.25 MPa or more in order to secure the strength of the wall surface.

The premix polyol composition may contain a polyol other than the above-mentioned polyols (A), (B) and polyester polyol (C) (hereinafter, referred to as polyol (D)). The weight average molecular weight of the polyol component (polyol (A) + polyol (B) + polyester polyol (C) + polyol (D)) contained in the premix polyol composition is preferably 600 to 1300, preferably 800 to 1000. Is more preferable. When the weight average molecular weight is smaller than 600, the viscosity of the premix polyol composition is lowered, the fluidity is improved, but the strength is lowered. On the other hand, when the weight average molecular weight is larger than 1300, the viscosity increases and the fluidity deteriorates remarkably.

The viscosity of the polyol component (polyol (A) + polyol (B) + polyester polyol (C) + polyol (D)) contained in the premix polyol composition at 25 ° C. is preferably 2000 to 6000 mPa · s. , 3000-5000 mPa · s is more preferable. When a polyol component having a viscosity of less than 2000 mPa · s is used, the viscosity of the rigid urethane foam raw material decreases and the fluidity improves, but liquid leakage occurs in the heat insulating housing mold having a complicated shape during the reaction of the rigid urethane foam. As a result, the final filling part of the heat insulating housing having a complicated shape is not filled with the rigid urethane foam. On the other hand, when the viscosity is larger than 5000 mPa · s, the fluidity of the hard urethane foam raw material is not sufficiently improved, and voids and density bias occur in the complicated shape portion of the heat insulating use housing having a complicated shape.

The foam stabilizer contained in the premix polyol composition of the present embodiment is not particularly limited, and known materials can be used. It is an alkylene oxide-modified polydimethylsiloxane, which is an organic silicone compound having an OH or an alkoxy group as a terminal group. For example, B8462, B8454, B8545, B8546, B8547 manufactured by Evonic, L6966, L6900, Y16300 manufactured by Momentive, SF2937F, SF2938F, SF2936F manufactured by Dow Corning, and the like can be used. The amount of these foam stabilizers is preferably 1.0 to 4.0 parts by mass with respect to 100 parts by mass of the premix polyol composition.

Next, the catalyst contained in the premix polyol composition of the present embodiment is not limited to the above-mentioned cyclic amine compound, the salt of the cyclic amine compound, and the carboxylate, and other catalysts may be used. As the type of catalyst, there is no particular limitation on the foaming catalyst, the resinification catalyst, the trimerization catalyst and the like, and known materials can be used. For example, as the foaming catalyst, pentamethyldiethylenetriamine, bis (dimethylaminoethyl) ether and the like can be specifically applied. Specifically, as a resinification catalyst, N, N, N'-trimethylaminoethylethanolamine, N, N-dimethylaminoethoxyethanol, diethylcyclohexylamine, triethylenediamine, N, N, N', N'-tetramethyl Hexamethylenediamine, N, N, N ″, N ″ -tetramethylpropylenediamine, N, N, N ″, N ″ -tetramethylethylenediamine and the like are preferable. Specifically, as a nucleolation catalyst, N, N', N''-tris (3-dimethylaminopropyl) hexahydro-s-triazine, N, N', N''-tris (3-diethylaminopropyl) hexahydro -S-Triazine and the like are suitable. These may be used alone or in combination of two or more. The amount of each of the above catalysts added is preferably 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the premix polyol composition. By mixing and reacting the premix polyol to which the catalyst has been added and the polyisocyanate in this way, the time in the liquid state is prolonged due to the delay in the initial foaming reaction, and the gel state due to the delay in the gel time in the middle of the reaction is obtained. It is possible to prolong the time. Assuming that the cream time (CT) at which the effervescence reaction starts and the gel time (GT) at which the cross-linking reaction starts are used as indicators of reactivity, the above-mentioned effervescence reaction is carried out by C.I. T. = 6-12 seconds, G.M. T. = 35 to 55 seconds.

The optimum blending ratio of water and cyclopentane contained in the premix polyol composition is 1.5 to 2.0 parts by mass of water and 14.0 to 18 parts by mass of cyclopentane with respect to 100 parts by mass of the premix polyol composition. It is .0 parts by mass. The mixing ratio of water and cyclopentane is not particularly limited as long as it is within the above range.

The rigid urethane foam of the present embodiment can be obtained by foaming the above-mentioned premix polyol composition with polyisocyanate. The polyisocyanate used in this embodiment may be any conventionally known polyisocyanate and is not particularly limited. For example, diphenylmethane diisocyanate (MDI) or tolylene diisocyanate (TDI) and its derivatives are suitable. These may be used alone or in combination. Examples of MDI and its derivative include a mixture of MDI and its polymer, polyphenylpolymethylene diisocyanate, and a diphenylmethane diisocyanate derivative having a terminal isocyanate group. Examples of TDI and its derivative include a mixture of 2,4-TDI and 2,6-TDI, a terminal isocyanate prepolymer derivative of TDI, and the like.

The rigid urethane foam of the present embodiment, which is formed by mixing a premix polyol composition and polyisocyanate and foaming, satisfies the aspect ratio (aspect ratio) = 1.5 to 3.0 with the cross-sectional shape being vertical in the foaming flow direction. Contains cells. Here, the rigid urethane foam is formed of closed cell cells. In general, in order to efficiently incorporate the foaming agent cyclopentane into the cell, a rapid foaming / curing reaction promotes spherical fine cells to achieve low thermal conductivity. However, a fast foaming / curing reaction shortens the time for fluidity. The rigid urethane foam of the present embodiment has high fluidity due to the prolongation of the liquid state time due to the delay of the initial foaming reaction and the prolongation of the gel state time due to the gel time delay in the middle of the reaction. The prolongation of the gel state time due to the gel time delay is characterized by making the cell shape into a vertically long elliptical shape 21 in the foaming direction (FIG. 6). Even if the cell is elliptical in the foaming direction 22, the cross section in the X-axis direction when the foaming direction is the Y-axis is a circular 23 cell (FIG. 7), so that the gas convection in the X-axis direction is almost the same as that of the spherical cell. The thermal conductivity is the same as before. From this, by controlling the injection point and the foaming direction of the raw material (premix polyol composition of the present embodiment + polyisocyanate) into the housing for heat insulating use, the heat insulating property can be maintained at the same level as before even in the elliptical cell. Can be done. For example, if a vertically long ellipse is located in the plane direction of the wall surface of the refrigerator housing, deterioration of the heat insulating performance can be suppressed. Further, when the rigid urethane foam of the present embodiment is applied to the housing of a refrigerator, the thermal conductivity is preferably 18.5 mW / m · K or less. The elliptical cells may occupy half or more, preferably 80% or more of the total number of cells, and may include some spherical cells.

Hereinafter, the effects of the premix polyol composition of the present embodiment and the hard urethane foam foamed by mixing it with polyisocyanate will be described with reference to Examples and Comparative Examples.

(Examples 1 to 13)
<Premix polyol composition and isocyanate addition amount>
The premix polyol composition was prepared using the polyol components shown in Table 1. As the polyol (A) component, at least one of A: tripropylene glycol, B: triethanolamine, and C: diethylene glycol-based polyether was used. Further, as the polyol (B) component, at least one of D: sorbitol, E: sucrose, F: toluenediamine, and G: triethanolamine to which an alkylene oxide was added was used. As the polyester polyol (C) component, at least one of H: phthalic acid type and I: benzoic acid type was used.

2.5 parts by mass of B8462 (manufactured by Evonic) was added as a foam stabilizer to 100 parts by mass of the polyol component shown in Table 1. Table 1 shows a total of 2.0 parts by mass of a foaming catalyst and a trimerization catalyst, a cyclic amine catalyst (cyclic amine compound) A: Dabco33LV, and a carboxylate catalyst B: DabcoTMR2 with respect to 100 parts by mass of the polyol component. According to the above, an arbitrary addition amount was added. All catalysts used were manufactured by Evanic. To 100 parts by mass of the polyol component, 2.0 parts by mass of water and 16.0 parts by mass of cyclopentane (manufactured by Maruzen) as a foaming agent, and 150 parts of mylionate MR200 (manufactured by Tosoh) which is a polymethylene polyphenyldiisocyanate as an isocyanate component. Added.

<Cell shape aspect ratio / aspect ratio>
When the rigid urethane foam containing the polyol component shown in Examples 1 to 13 is arranged in a region having a thickness of 10 mm or less, for example, an outer region of the inner box in a portion where the rail support member is located inside, the rigid urethane foam is arranged. Rigid urethane foam was collected in a direction orthogonal to the foam flow direction, and the aspect ratio with respect to the foam flow direction was measured.

Carbon spray FC-153 (manufactured by Fine Chemical Japan Co., Ltd.) was applied to the cross section of the rigid urethane foam and observed using a stereomicroscope (Digital Microscope VHX-1000 / 1100 ver.1.2 manufactured by Keyence Co., Ltd.). The aspect / width ratio of was calculated. Table 2 shows the average value of 20 cells.

<Thermal conductivity>
Thermal conductivity A 200 mm × 200 mm × 30 tmm foam is cut out from the above-mentioned urethane foam board, and at an average temperature of 10 ° C. using a heat flow type thermal conductivity measuring instrument (manufactured by Eiko Seiki Co., Ltd., model: HC-73). evaluated.

<Bending strength>
The bending strength was measured using an autograph (manufactured by Shimadzu Corporation, AG-100kNX). A rigid urethane foam of 80 mm × 250 mm × 30 tmm was cut out from the above-mentioned urethane foam board, loaded at a feed rate of 10 mm / min, and the load at the time of breaking the rigid urethane foam was divided by the square of the width and thickness of the rigid urethane foam. The value was taken as the bending strength.

In Examples 1 to 13, since the number of foam cells perpendicular to the bending direction increases, the bending strength is larger than that of the comparative example and the conventional example. As a result, even in the thin-walled portion, high strength can be exhibited against a load in the front-rear direction of the housing, which leads to improvement in the strength of the housing.

[Comparison example]
(Comparative Examples 1 to 3)
<Premix polyol composition and isocyanate addition amount>
The premix polyol composition was prepared using the polyol components shown in Table 1. As the polyol (A) component, at least one of A: tripropylene glycol, B: triethanolamine, and C: diethylene glycol-based polyether was used. Further, as the polyol (B) component, at least one of D: sorbitol, E: sucrose, F: toluenediamine, and G: triethanolamine to which an alkylene oxide was added was used. As the polyester polyol (C) component, at least one of H: phthalic acid-based, I: benzoic acid-based, and J: adipic acid-based was used.

2.5 parts by mass of B8462 (manufactured by Evonic) was added as a foam stabilizer to 100 parts by mass of the polyol component shown in Table 1. As the reaction catalyst, a foaming catalyst and a trimerization catalyst were added in a total amount of 2.0 parts by mass, a cyclic amine catalyst A: Dabco33LV, and a monoamine catalyst C: Polycat8 were added in an arbitrary amount according to Table 1 with respect to 100 parts by mass of the polyol component. rice field. All catalysts used were manufactured by Evanic. To 100 parts by mass of the polyol component, 2.0 parts by mass of water and 16.0 parts by mass of cyclopentane (manufactured by Maruzen) as a foaming agent, and 150 parts of mylionate MR200 (manufactured by Tosoh) which is a polymethylene polyphenyldiisocyanate as an isocyanate component. Added. The fluidity evaluation and the hard urethane foam physical property evaluation were carried out in the same manner as in Examples.

From Examples 1 to 8 and Comparative Example 1, in the premix polyol composition shown in Table 1, the polyol (A) was 5 to 10% by mass, the polyol (B) was 70 to 90% by mass, and the polyester polyol (C) was added. By containing 5 to 10% by mass, it was proved that the viscosity, the relative flow rate ratio and the cell shape aspect ratio (aspect ratio) showing high fluidity of the present embodiment were satisfied. In Comparative Example 1, since the polyol (A) component or the polyester polyol (C) component was added in a large amount, the viscosity was reduced and the bending strength was lowered. Further, in Comparative Example 1, the reactivity is high due to the effect of the primary hydroxyl group of the polyester polyol added in a large amount in the polyester polyol (C) component. Due to the increased reactivity, the urethane foam could not be raised evenly on the side surface of the housing, and unfilled voids were generated near the foam seams.

From Examples 9 to 13 and Comparative Examples 2 to 4, in the premix polyol composition shown in Table 1, by using a cyclic amine catalyst and a carboxylate-based catalyst, the viscosity and the flow velocity showing high fluidity of the present embodiment are exhibited. It was proved that the relative ratio and the cell shape aspect ratio were satisfied. In Comparative Example 2, since the amount of the cyclic amine catalyst A added is small and the initial reaction and the resinification reaction are slower than necessary, there is a concern that the liquid may leak from the mold. In Comparative Example 3, since the amount of the cyclic amine catalyst A added is large, the reactivity is high and the high fluidity is lost. In Comparative Example 4, since the monoamine catalyst C which does not show the property of delay was used, C.I. T. And G. T. Both are fast reactions. Therefore, in Comparative Examples 3 and 4, due to the increased reactivity, the urethane foam could not be raised evenly on the side surface of the housing, and unfilled voids were generated in the vicinity of the foam seams.

[Conventional example]
<Premix polyol composition and isocyanate addition amount>
The premix polyol composition was prepared using the polyol components shown in Table 1. As the polyol (A) component, C: diethylene glycol-based polyether was used. Further, as the polyol (B) component, E: sucrose, F: toluenediamine, and G: triethanolamine were used. The polyester polyol (C) component is not used.

2.5 parts by mass of B8462 (manufactured by Evonic) was added as a foam stabilizer to 100 parts by mass of the polyol component shown in Table 1. As the reaction catalyst, an arbitrary amount of monoamine catalyst C: Polycat8 was added to 100 parts by mass of the polyol component according to Table 1. All catalysts used were manufactured by Evonic. To 100 parts by mass of the polyol component, 2.0 parts by mass of water and 16.0 parts by mass of cyclopentane (manufactured by Maruzen) as a foaming agent, and 150 parts of mylionate MR200 (manufactured by Tosoh) which is a polymethylene polyphenyldiisocyanate as an isocyanate component. Added. The fluidity evaluation and the physical properties of the rigid urethane foam were evaluated in the same manner as in the examples.

1 ... Refrigerator 2 ... Insulation box 3 ... Rotating door 4 ... Pull-out door 5 ... Partition plate 6 ... Storage room 7 ... Foam heat insulating body 8 ...・ Machine room 9 ・ ・ ・ Base room 10 ・ ・ ・ Rail reinforcing member 11 ・ ・ ・ Screw 12 ・ ・ ・ Rail 13 ・ ・ ・ Inner box 14 ・ ・ ・ Outer box 15 ・ ・ ・ Case 16 ・ ・ ・ Rail member 17・ ・ ・ Rail support member 18 ・ ・ ・ Hinge 19 ・ ・ ・ Urethane heat insulating material 20 ・ ・ ・ Vacuum heat insulating material 21 and 23 ・ ・ ・ Cell wall of hard urethane foam 22 ・ ・ ・ Arrow indicating foam flow direction

Claims (6)

The outer box, the inner box, the vacuum heat insulating material arranged between the outer box and the inner box, and the rigid urethane foam foam-filled between the outer box and the inner box are provided. In the refrigerator
The region where the thickness of the hard urethane foam is 10 mm or less has a premix polyol composition containing an active hydrogen-containing compound, a defoaming agent, a catalyst, water, and cyclopentane.
The active hydrogen-containing compound includes a first active hydrogen-containing compound (A), a second active hydrogen-containing compound (B), and a third active hydrogen-containing compound (C).
The first active hydrogen-containing compound (A) is an active hydrogen-containing chain aliphatic compound having a weight average molecular weight of 200 or less, and the second active hydrogen-containing compound (B) contains 4 to 8 active hydrogens. The third active hydrogen-containing compound (C) is an active hydrogen-containing compound obtained by adding a polyhydric alcohol to a carboxylic acid, and is an aromatic polyester polyol, which serves as the catalyst. , A refrigerator comprising any of a cyclic amine compound, a salt of the cyclic amine compound, and a carboxylate. It has a storage chamber, a door that is pulled out together with a container to be stored in the storage chamber, and a rail support member that is provided on the side wall of the storage chamber and supports the door.
The side wall is formed of an outer box, an inner box, a vacuum heat insulating material arranged between the outer box and the inner box, and a rigid urethane foam foam-filled between the outer box and the inner box. In a refrigerator equipped with,
The outside of the inner box in the portion where the rail support member is located inside has a premix polyol composition containing an active hydrogen-containing compound, a defoaming agent, a catalyst, water, and cyclopentane.
The active hydrogen-containing compound includes a first active hydrogen-containing compound (A), a second active hydrogen-containing compound (B), and a third active hydrogen-containing compound (C).
The first active hydrogen-containing compound (A) is an active hydrogen-containing chain aliphatic compound having a weight average molecular weight of 200 or less, and the second active hydrogen-containing compound (B) contains 4 to 8 active hydrogens. The third active hydrogen-containing compound (C) is an active hydrogen-containing compound obtained by adding a polyhydric alcohol to a carboxylic acid, and is an aromatic polyester polyol, which serves as the catalyst. , A refrigerator comprising any of a cyclic amine compound, a salt of the cyclic amine compound, and a carboxylate. In the refrigerator according to claim 1 or 2.
The foaming flow direction as the vertical, refrigerator vertical / horizontal ratio is present closed cell cell satisfying 1.8 to 3.0, bending strength is equal to or not less than 0.41 MPa. In the refrigerator according to any one of claims 1 to 3.
The first active hydrogen-containing compound (A) is contained in an amount of 5 to 10% by mass of the premix polyol composition.
The second active hydrogen-containing compound (B) is contained in an amount of 70 to 90% by mass of the premix polyol composition.
A refrigerator containing 5 to 10% by mass of the premix polyol composition as the third active hydrogen-containing compound (C). In the refrigerator according to claim 4,
A refrigerator comprising 0.5 to 1.0% by mass of any of a cyclic amine compound, a salt of the cyclic amine compound, and a carboxylate as the catalyst of the premix polyol composition. In the refrigerator according to claim 3,
The third active hydrogen-containing compound (C) is at least in the group consisting of phthalic anhydride-based polyester polyol, phthalic acid ester-based polyester polyol, terephthalic acid-based polyester polyol, benzoic acid-based polyester polyol, and benzoic acid derivative polyester polyol. Refrigerator containing any one.

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