JPH11199696A - Production of foamed heat insulating material and production of heat-insulated box body by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the generation of cavitation for increasing the filling property, heat insulation and releasing property from a mold in the temperature elevation of a stock liquid of a foaming urethane containing a blowing agent of a useful material for protecting the earth environment. SOLUTION: This method for producing a foamed urethane as a heat insulating material by mixing a first stock liquid consisting of an organic isocyanate with a second stock liquid containing a polyol, foam regulating agent, catalyst, blowing agent and as necessary water, is provided by adjusting a temperature of the second stock liquid before mixing at a boiling point of a blowing agent or lower and also >=30 deg.C, and also mixing two stock liquids as colliding so as to make the temperature of the mixed liquid just after the mixing of the both liquids lower than the boiling point of the blowing agent and also >=30 deg.C. It is preferable to adjust the temperatures of the mixture of the second stock liquid before mixing the blowing agent to >=25 deg.C, and the viscosity thereof to >=12,000 cps, and also the temperature of the mixture after mixing the blowing agent lower than the boiling point of the above blowing agent and also >=30 deg.C and the viscosity thereof to >=800 cps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a foamed heat insulating material, which is a foamed urethane foam, for example, which is filled in a gap between an inner box and an outer box of a refrigerator to form a heat insulator, and a foam formed by the method. The present invention relates to a method for manufacturing a heat insulating box using a heat insulating material formed of a heat insulating material.

[0002]

2. Description of the Related Art Conventionally, an insulated box such as a refrigerator is
Rigid polyurethane foam with excellent heat insulation is injected and foamed into the gap formed by the bent product (outer box) of a thin metal plate such as an iron plate as the outer shell and the resin molded product (inner box) as the inner shell. It is formed by using a heat insulator constituted by this. In order to ensure excellent heat insulating properties of the rigid polyurethane foam constituting the heat insulator, monochlorotrifluoromethane (hereinafter, referred to as CFC-11) which is a chlorofluorocarbon (hereinafter, referred to as CFC) is used as a foaming agent for the rigid polyurethane foam. Or 1,1-dichloro-1, which is a hydrochlorofluorocarbon (hereinafter referred to as HCFC), which can significantly suppress the ozone layer destruction rate in order to protect the global environment.
-Fluoroethane (hereinafter referred to as HCFC-141b)
Alternatively, 1,1-dichloro-2,2,2-trifluoroethane (hereinafter, referred to as HCFC-123) or the like is used.

[0003] However, since chlorine which destroys the ozone layer together with hydrogen remains in the molecules of these blowing agents, hydrofluorocarbons (hereinafter referred to as HFCs) and hydrocarbons containing no chlorine in the molecules are included. (Hereinafter referred to as HC) has been proposed as a foaming agent for rigid polyurethane foam. Then, for example, 1,1,1,3,3-pentafluoropropane (hereinafter, referred to as HFC-245fa) or 1,1,1,1
4,4,4-hexafluorobutane (hereinafter referred to as HFC-3
JP-A-2-2359 discloses a method for producing a rigid polyurethane foam using an HFC such as 56 mff) as a foaming agent.
No. 82 is disclosed.

[0004] However, these HFCs have a global warming potential several hundred to several thousand times that of carbon dioxide, and cannot be said to be a useful substance in protecting the global environment.
Therefore, as an alternative, a method for producing urethane foam using a hydrocarbon such as cyclopentane as a foaming agent is disclosed in JP-A-3-152160.

A method of using a heat insulator composed of urethane foam using a hydrocarbon such as cyclopentane as a foaming agent disclosed in the above publication as a heat insulator for a refrigerator is as follows. A liquid of an organic isocyanate having a plurality of isocyanate groups (hereinafter also referred to as an isocyanate liquid), one or more polyols having a plurality of hydroxy groups, a tertiary amine as a catalyst, and an organic metal And a mixed solution in which a surfactant having a siloxane group or the like is dissolved as a foam stabilizer, and also cyclopentane or, in some cases, water is also dissolved or dispersed as a foaming agent (hereinafter referred to as a premix solution). Using a mixing device such as a foaming machine, the two liquids are mixed, and the mixed liquid is poured into the gap between the inner box and the outer box of the refrigerator, and then filled by foaming and expansion. Used for

[0006] As described above, the foaming agent used for the urethane foam is used in refrigerators because it is premixed with a polyol or the like since the number of working steps is reduced and the solubility stability of the surfactant is ensured. When forming a heat insulator, after inserting and fixing a heat insulation box such as a refrigerator in a foaming jig heated to 40 to 55 ° C., using a mixing device such as a high pressure foaming machine, the other undiluted solution is subjected to high pressure using a mixing device. Mix instantly by colliding with certain isocyanate liquids. Next, the foaming agent is vaporized and foamed by the reaction heat generated by the reaction of the two stock solutions mixed, and this urethane foam is injected into the gap between the inner box and the outer box of the refrigerator and filled by foaming and expansion to insulate. Form the body.

[0007] Urethane foam used as a foam heat insulating material has various characteristics. Among them, the heat insulating performance evaluated by thermal conductivity is an extremely important characteristic, and in order to improve the characteristics, it is used for a refrigerator, for example. At the time of forming the heat insulator, the foaming gas in the cell formed in the formed heat insulator is converted into a substance with low thermal conductivity, that is, the heat conductivity is low in the gaseous state and the molecule does not contain chlorine, and global warming It is most preferable to use cyclopentane as a foaming agent for urethane foam among hydrocarbons having a low conversion coefficient.

[0008]

As a foaming agent for urethane foam, which is a conventional foam heat insulating material as described above, cyclopentane, which has recently been replaced for the purpose of protecting the ozone layer, is used. Urethane foam using conventional HC
The fluidity was lower than that of a rigid polyurethane foam using FC-141b or CFC-11 as a foaming agent. Therefore, it is effective to secure a high exothermic temperature in order to obtain sufficient fluidity, and therefore, the activity of aromatic amines such as toluenediamine or diphenylmethanediamine, or aliphatic amines such as triethanolamine is effective. Addition of a high polyol and an increase in the amount of a catalyst were required.

As described above, in the method of activating the reaction between an organic isocyanate, water and a polyol by adding an amine-based polyol or increasing the amount of a catalyst, resinification by such a reaction rapidly progresses and foaming occurs. In some cases, the viscosity of the obtained resin suddenly increases, causing a problem that the fluidity is deteriorated. At this time, since the heat generated in the foamed resin is concentrated in a shorter time as compared with the case where the foamed resin exhibits a normal foaming state, heat accumulation inside the foamed resin is remarkable and the internal temperature of the foamed resin is several tens of degrees. Therefore, even if the foaming jig is inserted and fixed for the purpose of preventing deformation of the heat insulating box, it is difficult to remove the foaming jig. For this reason, there has been a problem that the internal temperature of the foamed resin has to be cooled until an appropriate temperature is reached by extending the demolding time or the like.

The molecular weight of cyclopentane is 70, and CFC-11 (molecular weight: 13
7), HCFC-141b (molecular weight; 117) or H
Since it is about half that of CFC-123 (molecular weight: 153), the amount of addition to the premix solution is very small, about half that of the prior art, to obtain urethane foam having the same expansion ratio, that is, foam density. No problem. However, in a premix solution containing a polyol having a high viscosity of several thousands to tens of thousands of cps as a main component, if the amount of cyclopentane, which is a low-viscosity substance as low as water, is reduced, the viscosity increases. 1200 cps as it is
That's all. This causes problems in the feeding and temperature control of the premix liquid and the like when foaming urethane foam into an insulating box such as a refrigerator.
There have been problems such as a reduction in the handling speed of the production equipment when producing urethane foam and an increase in the capacity of the production equipment. In addition, in mixing with an isocyanate liquid using a mixing device such as a high-pressure foaming machine,
In some cases, sufficient mixing properties could not be ensured.

Therefore, in order to solve such a problem, the viscosity of both the stock solutions of the isocyanate solution and the premix solution for producing foamed urethane is reduced by increasing the temperature of the stock solutions, and the mixing device such as a high-pressure foaming machine is used. Japanese Patent Application Laid-Open No. 7-2 is to improve the mixing property when using
No. 6056 discloses this.

[0012] However, simply raising the temperature of both stock solutions causes various problems. That is, the rise of the stock solution temperature in the production method of the above publication causes the foaming agent to evaporate in the high-pressure foaming machine by using the foaming agent (HCFC-141b) at a temperature (35 ° C.) exceeding the boiling point (32 ° C.). This tends to cause a phenomenon called "cavitation" in which bubbles are caught in the liquid sending pump, which is a measuring pump of the high-pressure foaming machine, and it is not possible to secure a normal quantitative liquid sending. Also, when the urethane foam is foamed, since the internal temperature of the foamed resin increases with the activation of the initial reaction,
It takes a long time to cool the foamed resin to the internal temperature at which the foamed resin does not deform when the foaming jig is removed, or the formed heat-insulating box is significantly deformed. However, there was a problem that was reduced.

The present invention has been made to solve the above problems, and uses cyclopentane, which is a substance useful for protecting the global environment, as a blowing agent, preferably in combination with water. In a rise in the temperature of the stock solution of urethane foam contained, generation of cavitation is suppressed, and a method of manufacturing a foamed heat insulating material capable of improving filling properties, heat insulating properties and mold release properties, and a method of manufacturing a heat insulating box body using the same. It is intended to provide.

[0014]

According to the present invention, there is provided a method for producing a foamed heat insulating material, comprising a first undiluted solution comprising an organic isocyanate and a second undiluted solution containing a polyol, a foam stabilizer, a catalyst, a foaming agent and, in some cases, water. And the temperature of the second undiluted solution before mixing is adjusted to be equal to or lower than the boiling point of the foaming agent and equal to or higher than 30 ° C., and the temperature of the mixed solution immediately after mixing both the undiluted solutions is adjusted to be equal to or lower than the boiling point of the foaming agent. In addition, this is a method in which impact-mixing is performed at 35 ° C. or more to form urethane foam as a heat insulating material.

In the method for producing a foamed heat insulating material according to the present invention, the temperature of the mixture before mixing the foaming agent of the second undiluted solution is 25 ° C.
In this method, the viscosity is adjusted to 12000 cps or more, and the temperature of the mixture after mixing the blowing agent is adjusted to be equal to or lower than the boiling point of the blowing agent and equal to or higher than 800 cps at 30 ° C. or higher.

In the method for producing a foamed heat insulating material according to the present invention, the foaming agent of the second stock solution contains a substance containing no chlorine in the molecule.

In the method for producing a foamed heat insulating material according to the present invention, the foaming agent of the second stock solution contains cyclopentane and water.

In the method for producing a foamed heat insulating material according to the present invention, the foaming agent of the second stock solution contains cyclopentane in an amount of 60% or more.

In the method for producing a foamed heat insulating material according to the present invention, the foaming agent of the second stock solution contains cyclopentane having a purity of 60% or more.

[0020] In the method for producing a foamed heat insulating material according to the present invention, the polyol of the second stock solution is prepared by converting the polyol having a hydroxyl value of 300 to 600 m.
It is a substance having a gKOH / g range and containing four or more functional groups.

In the method for producing a foamed heat insulating material according to the present invention, the organic isocyanate of the first undiluted solution may be a polymethylene polyphenyl polyisocyanate, a mixture of a modified polymethylene polyphenyl polyisocyanate and a modified product of diphenylmethane diisocyanate, or It is a mixture of a modified form of methylene polyphenyl polyisocyanate and polymethylene polyphenyl polyisocyanate.

The method for producing a heat insulating box according to the present invention is a method for producing urethane foam produced by the above-described method for producing a foamed heat insulating material, comprising: forming a box, a door or a part of a refrigerator or a similar product thereof; And a method using a heat insulator formed by injecting into the gap between the outer box and filling.

[0023]

1 and 2 are explanatory views of a manufacturing process for carrying out the present invention. The steps of the method for manufacturing a foamed heat insulating material according to the present invention, together with the drawings, are shown. A detailed description will be given of a manufacturing process in a case where a heat insulator composed of foamed urethane as a foam heat insulator is used for a refrigerator as a heat insulator box.

[First Step: Preparation of Isocyanate Solution and Premix Solution] As shown in FIG. 1, the isocyanate solution, which is one of the stock solutions of urethane foam, contains a plurality of isocyanate groups contained in a stock solution tank 2. Comprising a liquid of an organic isocyanate having the formula:

Examples of the organic isocyanate used in the isocyanate solution include a crude product of 4,4'-diphenylmethane diisocyanate (hereinafter, referred to as Polymeric MDI) or toluene diisocyanate (hereinafter, referred to as TDI) and a modified product thereof. May be used alone or a mixture of those generally used conventionally, but polymethylene polyphenyl polyisocyanate, a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate, Alternatively, a mixture of modified polymethylene polyphenyl polyisocyanate and polymethylene polyphenyl polyisocyanate is preferable, and the amount of the mixture is not particularly limited. As a result, a resin composition having excellent reactivity is obtained, the curing rate of the resin at the time of demolding is increased, and the demolding time is shortened.

As shown in FIG. 1, a premix solution, which is another stock solution of urethane foam, contains a polyol, which is a resin raw material as a main component, in a stock solution tank 1, and a catalyst and a foam stabilizer are charged. At this time, the mixture was heated at a temperature of 25 ° C. and a viscosity of 12,000 by heating means provided in the stock solution tank 1.
Heat and adjust so as to be more than cps. Next, a liquid foaming agent is added and stirred and mixed to prepare a premix liquid.
Then, the temperature of the premix liquid is adjusted to a temperature not higher than the boiling point of the liquid foaming agent and 30 ° C. by a heating means provided in the stock solution tank 1.
The above is adjusted, and the viscosity is adjusted to 800 cps or more. In addition, you may mix a foaming auxiliary agent, such as water, with a liquid foaming agent as needed.

As the polyol used in the premix solution thus prepared, almost all polyols usually used as urethane raw materials can be used. Among them, polyhydric alcohols such as ethylene glycol, glycerin, and trihydric alcohol can be used. Starting materials such as methylolpropane and bisphenol A, propylene oxide,
Although it may be obtained by addition polymerization of ethylene oxide, it is obtained by addition polymerization using pentaerythritol, sorbitol, sucrose, ethyleneamines as aliphatic amines, tolylenediamine as aromatic amines as starting materials, and the like. Those obtained by subjecting esters to glycerin addition polymerization are particularly preferable.
In this case, the polyol has a hydroxyl value (OHV) of 300 to 600 mgKOH /, which increases the crosslink density for obtaining a resin composition having a high heat deformation temperature up to the time of demolding.
Those having a number of functional groups of 4 or more within the range of g are preferable. The above polyol may be used as a mixture of two or more.

Known foam stabilizers are known as foam stabilizers that play a role in ensuring foam stability during foaming after the reaction of an organic isocyanate and a polyol when an isocyanate solution and a premix solution are mixed and adjusting the shape or size of the foam. Organic silicon compound-based surfactants such as F-230, F-305, F-230 manufactured by Shin-Etsu Silicone Co., Ltd.
341 or F-348, L manufactured by Nippon Unicar Co., Ltd.
-544, L-5310, L-5320, L-5420
Or L-5720, SH manufactured by Toray Silicone Co., Ltd.
-193, SH-195, SH-200 or SRX-
253, TFA-4200 manufactured by Toshiba Silicone Co., Ltd.
Or TFA-4202 (both are trade names).

As the catalyst for adjusting the foaming or curing speed, a known amine catalyst or a metal catalyst alone or in combination is used. For example, tertiary amines such as trimethylamine and trimethylamine are used for the amine catalyst. Ethylenediamine, N-ethylmorpholine, trimethylaminoethylpiperazine, N, N′-dimethylaminoethylether, pentamethyldiethylenetriamine or tetramethylhexamethylenediamine, and the like. In a metal catalyst, dibutyltin dilaurate, which is an organic metal salt, Examples include tin laurate dichloride, lead octoate, cobalt naphthenate or nickel naphthenate.

As the liquid foaming agent, a hydrocarbon containing no chlorine in the molecule and having a low global warming coefficient is used, and among them, cyclopentane is preferable. In this case, it is preferable to use high-purity cyclopentane as the liquid foaming agent in order to reduce the thermal conductivity and increase the heat insulating property and the filling property, and it is more preferable that the liquid foaming agent has a purity of 60% or more. . The content of cyclopentane is 6% of the liquid foaming agent.
It is preferred to be 0% or more. Also in this case, the deterioration of the thermal conductivity is suppressed, and the heat insulating property is enhanced.

The temperature of the prepared premix liquid is preferably not higher than the boiling point of the liquid blowing agent (boiling point of cyclopentane, 49 ° C.) and not lower than 30 ° C. before mixing with the isocyanate liquid. By increasing the temperature of the premix liquid below the boiling point and above 30 ° C., the increase in viscosity due to resinification is suppressed, the filling property is enhanced, and the occurrence of cavitation is suppressed. Further, it is preferable that the viscosity of the premix liquid is 800 cps or more at a temperature of 30 ° C. or more when the liquid foaming agent is mixed. In this case, even if foaming is performed at a high stock solution temperature, enlargement of the bubble size of the foamed urethane is suppressed, and heat insulation is enhanced.

Water, which is a foaming aid mixed with the liquid foaming agent as needed, reacts with the organic isocyanate to generate carbon dioxide gas, which is one of the foaming agents. Therefore, the content is preferably 3 parts or less, more preferably 2 parts or less, based on 100 parts of the polyol. This is because the miniaturization of the cell is achieved, the deterioration of the thermal conductivity is suppressed, and the fluidity is enhanced.

[Second Step: Mixing Step of Isocyanate Solution and Premix Solution] The isocyanate solution and the premix solution produced in each stock solution tank 2, 1 are supplied to a high pressure feeder connected to each stock solution tank 2, 1. The liquid is sent to the mixing head 4 of the mixing device (high-pressure foaming machine) by the liquid pumps 3 and 3a, and a mixed liquid is produced. At this time, the mixing of the two stock solutions collides at a high pressure (60 to 180 kg / cm ² ), and is achieved in the colliding surface and the subsequent turbulent state, and the temperature rises due to frictional heat (heat generation) at the time of the collision. . Then, this temperature rise is 5 to 10 ° C. higher than the temperature of both stock solutions in the liquid state until the mixed liquid starts foaming, that is, 35 ° C.
The temperature is preferably set to not less than ° C. This is because gasification of the liquid foaming agent is efficiently performed by setting the temperature of the mixed liquid to be equal to or lower than the boiling point of the liquid foaming agent and equal to or higher than 35 ° C., and the fluidity is increased.

[Third Step: Manufacturing Process of Molded Product (Heat Insulation Body) and Heat Insulation Box] In FIG. 2, an inner box obtained by vacuum molding ABS resin of a refrigerator as a heat insulation box is formed by bending a steel plate. Then, it is inserted into the outer box molded and assembled to assemble the body frame of the refrigerator (STEP 1). Next, the assembled main body frame is mounted on a foaming jig having a role of preventing deformation of the inner box and the outer box caused by the pressure generated when the urethane foam is foamed (STEP 2). The foam jig is 3
It is previously adjusted to an arbitrary temperature between 5 and 50 ° C. Next, a mixed solution (urethane foam) prepared by mixing both stock solutions of an isocyanate solution and a premix solution in a gap formed by an inner box and an outer box of a main body frame fixed to a foaming jig.
When the mixture is injected, the mixture is filled without gaps in the gap in the process of foaming by the liquid foaming agent vaporized by the heat generated by the reaction between the organic isocyanate and the polyol and water,
A heat insulator is formed (STEP 3). Then, it is left for several minutes so that the foam filling of the urethane foam and the curing of the resin are sufficiently performed, the fixing of the foaming jig is released, and the heat insulating box formed of the heat insulator is taken out (STEP 4). Next, a refrigerator circuit is completed by installing a refrigerant circuit component, an electric device component, an interior component, and the like in the obtained heat insulating box (STEP 5).

As described above, the OHV is 300 to 600 mg.
Polyol, foam stabilizer, catalyst, and optionally water having a functional group number of 4 or more in the range of KOH / g and a liquid having a purity of 60% or more and cyclopentane having a content of 60% or more Before mixing the liquid foaming agent, the premix liquid into which the foaming agent is mixed is adjusted to a temperature of 25 ° C. or higher and the viscosity to 12000 cps, and after mixing the liquid foaming agent, the temperature is adjusted to a temperature not higher than the boiling point of the liquid foaming agent and 30 ° C. By adjusting the viscosity at 800 ° C. or higher to 800 cps or higher,
The heat insulating property and the demolding property are enhanced, and the occurrence of cavitation can be suppressed.

Polymethylene polyphenyl polyisocyanate, a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate, or a mixture of modified polymethylene polyphenyl polyisocyanate and polymethylene polyphenyl polyisocyanate, etc. An isocyanate liquid comprising an organic isocyanate of the formula (I), a polyol, a foam stabilizer, a catalyst, water in some cases, and a liquid blowing agent having a purity of 60% or more and cyclopentane having a content of 60% or more are mixed. And a premix liquid whose viscosity is adjusted to 800 cps or more at a temperature not higher than the boiling point of the liquid foaming agent and not less than 30 ° C., so that the temperature is not higher than the boiling point of the liquid foaming agent and not lower than 35 ° C. Impingement mixing allows the mixture to flow Sex is enhanced.

Further, by filling a gap formed by an inner box and an outer box of a refrigerator, which is a heat insulating box, with a foamed heat insulating material using the above-mentioned mixed solution as a stock solution to form a heat insulating body.
An increase in the internal temperature of the foamed resin during foaming of the foamed heat insulating material can be suppressed, and a decrease in mold release properties can be suppressed.

Accordingly, polymethylene polyphenyl polyisocyanate, a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate, or a mixture of modified polymethylene polyphenyl polyisocyanate and polymethylene polyphenyl polyisocyanate, etc. An isocyanate solution comprising an organic isocyanate of OHV 300 to 600
a polyol having a functional group number of 4 or more in the range of mgKOH / g, a foam stabilizer, a catalyst, optionally water, and a liquid having a purity of 60% or more and cyclopentane having a content of 60% or more A foaming agent is mixed, the temperature is below the boiling point of the liquid foaming agent, 30 ° C. or more, and the viscosity is 800 cp.
s or more and a premix liquid adjusted so that the temperature is equal to or lower than the boiling point of the liquid foaming agent and equal to or higher than 35 ° C. at the time of mixing the two stock solutions. Since it is high and can suppress the occurrence of cavitation as a foamed heat insulating material constituting the heat insulator of the heat insulating box and can suppress a decrease in removability, it is suitable as a foam heat insulating material used for the heat insulating box. You can see that. The effects of the foam insulating material and the heat insulating box will be specifically described below using examples.

[0039]

EXAMPLES [Examples 1 to 5] In each of the examples and comparative examples, when a liquid foaming agent of foamed urethane, which is a foamed heat insulating material, and cyclopentane were mixed, the properties of the stock solution were homogeneous and safe. A raw material system that is completely compatible and transparent so as to obtain a liquid is selected, and the temperature at the time of mixing the premix solution of the stock solution and the isocyanate solution is equal to or lower than the boiling point of the liquid foaming agent and equal to or higher than 35 ° C. As described above, the miniaturization, filling and demolding properties of the cell based on the improvement of the flowability of the foamed resin obtained by adjusting and mixing the average temperature of both the stock solutions to 30 ° C. or more, and the most important as a heat insulating material The effect on the heat insulation property, which is a characteristic, was examined.

First, raw materials are formulated as shown in Table 1, and urethane foam panels to be used as samples, Examples 1 to 5 and Comparative Examples 1 to 3 are formed by the following methods (1) to (3). (1) A premix liquid is prepared by mixing a polyol, a foam stabilizer, a catalyst, water and cyclopentane as a liquid foaming agent based on a predetermined compounding ratio (see FIG. 1). (2) The prepared premix liquid and the isocyanate liquid comprising the organic isocyanate are respectively charged into the raw material tanks, the temperature is adjusted by a heating means, and the two raw liquids are crushed and mixed at a predetermined mixing ratio using a high-pressure foaming machine. A liquid was prepared, and the mixture was heated to 50 ° C., and had an inner dimension of 300 (width).
An aluminum mold of × 1100 (height) × 50 (thickness) mm is filled from an injection port provided at the lower part of the aluminum mold and filled to form a foam that overflows about 100 mm from the upper part of the aluminum mold (FIG. 1 and FIG. 1). (See FIG. 3). (3) A foamed urethane sample formed by encapsulating and foaming in an aluminum mold so that the weight of the filled foam becomes 15% more than the weight of the portion where the overflowed portion was removed, and demolding after a demolding time of 6 minutes. (See FIGS. 1 and 3).

[0041]

[Table 1]

In Examples 1 to 5, the OHV of the polyol was used.
Are different from 410, 450, 380, and 500 (polyols A to D) so that the total weight of the polyol becomes 100 parts, and the temperature at the time of mixing the premix liquid and the isocyanate liquid is 60 kg / cm ² or more. The temperature of the premix solution is adjusted to 30 ° C. or 35 ° C., the temperature of the isocyanate solution is adjusted to 30 ° C. or 25 ° C., and the viscosity of the premix solution is adjusted so that the temperature becomes 35 ° C. or higher when subjected to collision mixing at a high pressure. 800 cp when pentane is mixed
s or more. Comparative Examples 1 and 2
In the comparative examples 2 and 3, the temperature of each stock solution was adjusted to 20 ° C. so that the temperature at the time of mixing the premix solution and the isocyanate solution did not reach 35 ° C. Adjusted.

In Examples 1 to 5 and Comparative Examples 1 to 3, free foams of urethane foam as samples were formed by the following methods (4) to (6), and the reaction rates and densities of the formed samples were as follows. Is measured with the following measurement contents. From the measurement results, the amount of the liquid blowing agent is increased when the strength or the density affecting the flow of the foamed resin is higher than a desired value, and the amount of the catalyst is decreased when the reaction rate affecting the thermal conductivity is high. For example, the amounts of the liquid foaming agent and the catalyst were adjusted so that the properties such as the filling property and the heat insulating property could be compared and examined. (4) A polyol, a foam stabilizer, a catalyst, water and cyclopentane which is a liquid foaming agent are mixed based on an arbitrary mixing ratio to prepare a premix liquid. (5) The prepared premix solution and the isocyanate solution composed of organic isocyanate are respectively charged into a stock solution tank, the temperature is adjusted by a heating means, and both stock solutions are transferred to a beaker and stirred for about 5 seconds by an impeller mixer having a rotation speed of 5000 rpm. Mix. This mixed solution has an internal size of 200
Inject and fill into a (width) × 200 (height) × 200 (thickness) mm box. (6) After the foaming of the filled liquid mixture in the middle of foaming is pierced with a sharp stick and the state thereof is observed, the foamed foam is removed from the box-shaped urethane foam after 2 hours of demolding time at room temperature. Obtain a free form for the sample. Reaction speed: gel time (hereinafter referred to as GT), which is the time during which foaming of the mixed liquid filled in the box during foaming is pierced with a drill-like rod to convert the mixed liquid into a resin and form a deposit in the form of a thread;
And a tack-free time (hereinafter referred to as TFT), which is a time during which the resin does not adhere even when the foam surface is touched with a finger. Density: The apparent density determined from the apparent volume and weight obtained by cutting the free form of the box-shaped urethane foam sample as a sample into a cubic shape having a side of 100 mm from the center and measuring the external dimensions of the processed product using calipers.

Then, in each sample which is a urethane foam panel formed according to the above-mentioned methods (1) to (3), the core density of the foam (15 mm for both sides of the sample panel)
While measuring the physical properties of the core portion obtained by removing the core, the demold expansion coefficient and the cell size, as shown in FIG. 3, individual plates (X1 to X1) obtained by dividing the sample panel X into four equal parts were obtained.
The thermal conductivity and the compressive strength of the sample taken from the center of 4) were measured. The content of each measurement is as follows,
Table 2 shows the measurement results. Core density: The apparent density obtained from the apparent volume and weight obtained from the external dimensions of the caliper. Thermal conductivity: Anacon-model 88 applying the flat plate comparison method
(Amco). Compressive strength: 10% at a compression speed of 10 mm / min
Strength when strained. Demold expansion rate: A dimensional difference obtained from a thickness measured by a caliper and a dimension in a mold. Cell size: Cell evaluation by visual observation. ：: good (extremely fine), Δ: somewhat good (fine), ×:
Bad (bloated)

[0045]

[Table 2]

As is clear from Table 2, Comparative Examples 2 and 3 in which the temperature of both stock solutions was adjusted to 20 ° C. so that the temperature during mixing of the premix solution and the isocyanate solution did not reach 35 ° C.
In order to obtain the same reaction rate and density as in Examples 1 to 5 and Comparative Example 1 in which the temperature of each stock solution was adjusted so that the temperature at the time of mixing both stock solutions was 35 ° C. or higher, a catalyst and a liquid foaming agent were used. The amount is large. For this reason, the core density is high, the thermal conductivity and the compressive strength are low, and the thermal conductivity,
Affects compressive strength or foamed resin flow.
This means that when the temperature of the stock solution is increased, the temperature at the time of mixing both stock solutions tends to increase, but without the promotion of resinification such that the gelation time is shortened with the increase in the temperature,
Example 1 has no effect of accelerating the increase in viscosity due to resinification.
No. 5 and Comparative Example 1 do not show a decrease in the filling property. In other words, the temperature rise during mixing with the rise in the temperature of the stock solution depends on the amount of temperature rise required to reach the temperature at which the liquid foaming agent, which appears as a result of the polymerization reaction of the resin, evaporates and starts foaming. This is because it is much smaller than in the case where a large amount is used, and the subsequent vaporization of the liquid foaming agent is also promoted, so that it is difficult to reach the excessive weight region where the viscosity rises sharply. Thereby, in order to obtain a high filling property, as in Examples 1 to 5 and Comparative Example 1, the temperature of the premix liquid before mixing with the isocyanate liquid is set to be equal to or lower than the boiling point of the liquid foaming agent and equal to or higher than 30 ° C, It is understood that the temperature of the mixed liquid after mixing is preferably equal to or lower than the boiling point of the liquid foaming agent and equal to or higher than 35 ° C.

In Comparative Example 1 in which the temperature of the premix solution was raised to 35 ° C. and the viscosity difference from the isocyanate solution was reduced while maintaining the average temperature of both stock solutions, the viscosity of the premix solution was less than 800 cps, 800c even if there is a difference
The thermal conductivity is lower than that of Example 1 which is not less than ps. On the other hand, in Example 5 in which the temperature of the premix solution was raised to 35 ° C. and the viscosity difference from the isocyanate solution was reduced while maintaining the average temperature of both stock solutions, the viscosity of the premix solution was 8
Example 3 in which the same raw material formula was obtained at a rate of 00 cps or more.
Almost the same as the thermal conductivity of The cell size of Comparative Example 1 is larger than those of Examples 1 to 5.
This is because the viscosity of the premix liquid at the time of mixing with the isocyanate liquid is too low, and the foam nuclei, which are fine bubbles formed by instantaneous vaporization of air dissolved under pressure in each stock solution, are not sufficiently generated. This suggests that the thermal conductivity is high and the heat insulation is poor. In addition, the viscosity is 800
The reason why the cell size is good in Comparative Example 2 below cps is that since the amount of the catalyst and the liquid foaming agent is large, nuclei for foaming are sufficiently generated by the catalyst and the liquid foaming agent. Thereby, in order to obtain a low heat conductivity, that is, a high heat insulating property, as in Examples 1 to 5, the viscosity of the premix liquid before mixing with the isocyanate liquid is set to 80.
It is preferable to be 0 cps or more.

In order to obtain sufficient fluidity, it is effective to increase the temperature at the time of mixing the two stock solutions. For this reason, as in Comparative Examples 2 and 3, the amount of the catalyst was increased to increase the reaction between the two stock solutions. Is activated. However, at this time, the internal temperature of the foamed resin becomes high, and it is necessary to extend the demolding time with this temperature rise. Therefore, the reaction rate of the foamed resin is increased to increase the heat distortion temperature at the time of demolding, and the heat resistance of the foamed resin at the time of demolding is improved. It is conceivable to use a resin composition having the same. In order to obtain a resin composition having a high heat distortion temperature, it is preferable to increase the crosslink density, and it is effective to have a cyclo ring or an aromatic ring in the resin structure. As a result, the polyols have an OHV of 300 to
Those having a range of 600 mg KOH / g and having four or more functional groups are preferred, and Examples 3 and 4 having a smaller demolding expansion coefficient than Examples 1 and 2 are particularly preferred.

Therefore, as in Examples 1 to 5, OH
V is in the range of 300 to 600 mgKOH / g, and a polyol, a foam stabilizer, a catalyst, and optionally water and a liquid foaming agent containing 4 or more functional groups are mixed, and the temperature is not higher than the boiling point of the liquid foaming agent; 800c viscosity at 30 ° C or higher
The mixture obtained by mixing the premix solution adjusted to not less than ps and the isocyanate solution so that the temperature is equal to or lower than the boiling point of the liquid foaming agent and equal to or higher than 35 ° C. at the time of mixing the two stock solutions has a filling property and a heat insulating property. It can be seen that the material has high fluidity and is suitable for foam insulation.

Example 6 In each of the examples and comparative examples, when a liquid foaming agent of urethane foam, which is a foamed heat insulating material, and cyclopentane are mixed, the properties of the stock solution are uniform and a safe state can be obtained. Select a raw material system that is completely compatible and transparent as described above, and change the purity of cyclopentane and the water content of the premix solution of the stock solution to change the temperature at the time of mixing with the isocyanate solution. Below boiling point and 3
The foaming resin obtained by adjusting the average temperature of both the stock solutions to 30 ° C. or more and mixing so that the temperature becomes 5 ° C. or more, and the filling property and the demolding property based on the improvement of the fluidity, and the low thermal conductivity The effect of the pentane content on the heat insulation was investigated.

First, raw materials were formulated as shown in Table 3 and urethane foam panels to be used as samples by the methods (1) to (3) described in Examples 1 to 5, Examples 1 to 4 and Example 6 And Comparative Examples 4 to 6 are formed.

[0052]

[Table 3]

In Examples 1 to 4 and Example 6, polyols having different OHVs of 410, 450, 380 and 500 (polyols A to D) were combined so that the total weight of the polyol was 100 parts. The purity of the liquid foaming agent was 95% or 60% (foaming agents I and J). In Example 6, the contents of the liquid foaming agent and water were changed. In Comparative Examples 4 and 5, the purity of the liquid foaming agent was 4
In Comparative Example 6, the content of the liquid foaming agent was changed and water was not contained. In Examples 1 to 4 and Example 6 and Comparative Examples 4 to 6, a free foam of urethane foam as a sample was formed by the methods (4) to (6) described in Examples 1 to 5, and this free foam was formed. The amounts of the liquid blowing agent and the catalyst were adjusted so that the density of the foam was almost the same.

In cyclopentane, most of the impurities are isomers such as n-pentane and i-pentane, and homologues having different carbon numbers such as hexane, and aromatic and aliphatic compounds such as toluene and xylene. The content of substances having a function as a solvent, such as system aldehydes, is extremely small, and does not exert an effect of destroying foamed foam.

Then, the viscosity of the premix liquid is 800 c
While adjusting the temperature of both stock solutions so that it does not fall below ps,
In each sample which is a urethane foam panel formed based on the methods (1) to (3) described in Examples 1 to 5,
The core density of the foam (the density which is the physical property of the core portion obtained by removing both sides of the sample panel by 15 mm) and the demold expansion coefficient were measured, and as shown in FIG.
The thermal conductivity and the compressive strength were measured for those obtained from the central part of each plate (X1 to X4) obtained by dividing the plate into four equal parts.
The details of each measurement are as described in Examples 1 to 5, and the measurement results are shown in Table 4.

[0056]

[Table 4]

As is clear from Table 4, when the purity of cyclopentane is reduced, the compressive strength is slightly increased, but the thermal conductivity, which is the most important property as a heat insulating material, is considered to be the thermal conductivity. Average of 0.0176 kcal / mh in Comparative Examples 4 and 5 in which the purity of pentane is 40%
K, 0.0175 kcal / mhK, and Examples 1-4 and Example 6 in which the purity of cyclopentane is 60% or more.
It turns out that it becomes higher than the thing of Comparative Example 6, and heat insulation is low. This indicates that cyclopentane has a lower thermal conductivity than any of the other HCs with similar boiling points, so the decrease in absolute amount with increasing impurities increased the thermal conductivity. .

In Example 6 and Comparative Example 6 in which the content of water was reduced and the content of cyclopentane was increased,
The increase in the content of cyclopentane in the mixed foaming gas with carbon dioxide gas causes not only an insufficient decrease in thermal conductivity, but also an increase in thermal conductivity in Comparative Example 6, which does not contain water. Although not shown in FIG. 4, when the size of the cell was evaluated by visual observation, it was confirmed that the cell became larger as the content of cyclopentane was increased, and the decrease in the radiation heat insulation performance was due to the heat insulation performance of the gas in the cell. It can be seen that it exceeded the improvement of.

Further, the decrease in the content of water, which has been responsible for the initial reaction with the organic isocyanate, and the increase in the content of cyclopentane, which has a very high boiling point, reduce the heat generated during foaming due to resinification. Because the amount increases by absorption with vaporization, the viscosity of the mixed solution and the foam during foaming is reduced together with the delaying effect of resinification, and the progress of foaming becomes uneven. In Example 6 and Comparative Example 6,
It can be seen that the core density and the demolding expansion rate are high and the compressive strength is low, which affects the fluidity, the filling property and the demolding property. This is because bubbles generated by the initial vaporization tend to concentrate on the foaming tip of the sample panel formed by enlargement due to the low viscosity of the liquid mixture during foaming, and furthermore, demolding due to the delay of the reaction. It can be said that the demold expansion rate was increased due to the decrease in resin strength at the time. In particular, in Comparative Example 6 in which the demolding expansion rate exceeds 2%, the demolding property is reduced to such an extent that the appearance design is impaired, and it can be seen that it is difficult to use it for a heat insulating box such as a refrigerator.

Therefore, Examples 1-4 and Example 6
The use of cyclopentane having high purity, preferably 60% or more in purity, and mixing a premix solution using water and an isocyanate solution together with an isocyanate solution provides fluidity, filling properties, heat insulation and demolding. It can be seen that the property is high and suitable for foam insulation.

Examples 7 and 8 In both Examples and Comparative Examples, when a liquid foaming agent of urethane foam, which is a foam heat insulating material, and cyclopentane were mixed, the properties of the stock solution were homogeneous and safe. Select a raw material system that is completely compatible and transparent so that it can be obtained, change the type of organic isocyanate in the isocyanate solution of the stock solution, mix it with the premix solution, and demold the foamed resin obtained by this The effect on sex was investigated.

First, raw materials were formulated as shown in Table 5, and urethane foam panels to be used as samples were prepared by the following methods (1) to (3). Examples 1, 3, 7, 8 and Comparative Examples 7, 8 To form (1) A premix liquid is prepared by mixing a polyol, a foam stabilizer, a catalyst, water and cyclopentane as a liquid foaming agent based on a predetermined compounding ratio. (2) The prepared premix liquid and the isocyanate liquid comprising the organic isocyanate are respectively charged into the raw material tanks, the temperature is adjusted by a heating means, and the two raw liquids are crushed and mixed at a predetermined mixing ratio using a high-pressure foaming machine. A liquid was prepared, and the mixture was heated to 50 ° C., and had an inner dimension of 300 (width).
An aluminum mold having a size of 1100 (height) x 50 (thickness) mm is filled from an injection port provided at a lower portion of the aluminum mold, and filled to form a foam that overflows from the upper portion of the aluminum mold by about 100 mm. (3) A foamed urethane sample formed by enclosing and foaming in an aluminum mold so that the weight of the filled foam is increased by 15% of the weight after removing the overflowed portion, and then demolding after a demolding time of 5 minutes. Get a panel for

[0063]

[Table 5]

In Examples 1, 3, 7 and 8, polyols having different OHV from 410, 450, 380 and 500 (polyols A to D) were prepared by adding 10 parts by weight of total polyol.
The organic isocyanate is either polymethylene polyphenyl isocyanate (isocyanate K) or a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate (isocyanate K1). In Comparative Examples 7 and 8, the organic isocyanate was toluene diisocyanate (isocyanate L), and the water content was changed. Examples 1, 3, 7, 8
In Comparative Examples 7 and 8, the method (4) described in Examples 1 to 5 was performed using a free foam of urethane foam as a sample.
(6), and the amount of the catalyst was adjusted so that the density of the free form became substantially the same.

Then, the viscosity of the premix liquid is 800 c
While adjusting the temperature of both stock solutions so that it does not fall below ps,
In each sample which is a urethane foam panel formed based on the above methods (1) to (3), the core density of the foam (the density which is the physical property of the core portion obtained by removing both sides of the sample panel by 15 mm), In addition to measuring the thermal conductivity and the demold expansion coefficient, as shown in FIG. 3, the compressive strength was measured for a sample taken from the center of each plate (X1 to X4) obtained by dividing the sample panel X into four equal parts. did. The details of each measurement are as described in Examples 1 to 5, and the measurement results are shown in Table 6.

[0066]

[Table 6]

As is clear from Table 6, Examples 1 and 3 using polymethylene polyphenyl isocyanate as the organic isocyanate and Examples using a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate 7, 8 and Comparative Examples 7, 8 using toluene diisocyanate can be confirmed that there is not much difference in each property if the raw material composition of the premix liquid is the same. However, Comparative Examples 7 and 8 using toluene diisocyanate have a high demold expansion coefficient, which exceeds 2%, which impairs the appearance and design. This is because the resinification reaction with a polyol or the like is inferior.
That is, the organic isocyanates used in Examples 1, 3, 7, and 8 are excellent in resinification reaction with polyols and the like,
A resin composition having a high degree of polymerization is easily obtained, and the curing rate of the resin at the time of demolding is increased. As a result, the demolding expansion rate is reduced, and the demolding time can be shortened.

Therefore, as in Examples 1, 3, 7, and 8, polymethylene polyphenyl polyisocyanate, a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate, or polymethylene polyphenyl is used as the organic isocyanate. It can be seen that a mixed liquid obtained by mixing an isocyanate liquid, such as a mixture of a modified polyisocyanate and a polymethylene polyphenyl polyisocyanate, with a premix liquid has a high mold release property and is suitable for a foam insulation material.

[Examples 9 to 11] Here, in each of the examples and comparative examples, the premix liquid of Example 1 was used, and the temperature was changed as shown in Table 7 to produce urethane foam. In FIG. 1), the high-pressure foaming machine (see FIG. 4) is operated by repeating the circulation of the premix liquid and the isocyanate liquid from the respective raw material tanks to the liquid feed pump and the mixing head. Then, the dissolved gas is gasified due to a change in the circulation pressure before and after the orifice of the liquid feeding pump and the mixing head, and fine bubbles are generated, thereby making it impossible to secure the liquid feeding amount of the proper weight set by the liquid feeding pump. Focusing on the phenomenon, the premix liquid circulating when cavitation occurs becomes a state containing excessive bubbles, the density of the bubbles of the premix liquid at this time is obtained by a measuring method described below, and the cavitation The state of occurrence was evaluated and the optimum temperature of the premix solution was examined.

The premix solution of Example 1 was used,
One having a temperature of 55 ° C. exceeding the boiling point of cyclopentane was designated as Comparative Example 9. The method of measuring the density of the foam is as follows. Table 7 shows the temperature of the premix liquid, the density of each foam, and the presence or absence of abnormal noise during the operation of the liquid feeding pump in Examples 9 to 11 and Comparative Example 9. Shown in Foam density: 20 minutes for 3 minutes alternately between passing the premix solution through the orifice of the mixing head and circulating it without passing through the orifice using the bypass in front of it.
The cycle is performed, and then the premix liquid in the raw material tank is collected and allowed to stand for 1 minute, and the apparent density is determined from the volume and weight measured using a measuring cylinder.

[0071]

[Table 7]

As is clear from Table 7, Comparative Example 9 in which the temperature of the premix liquid was 55 ° C., which was higher than the boiling point of cyclopentane, was free from bubbles in the stock solution by pressurizing and dissolving nitrogen or the like in the raw material tank. The density of the original premix liquid used in the state was significantly lower than 1.13 kg / cm ² , and an abnormal sound of the liquid sending pump was also generated. This suggests that in Comparative Example 9, air bubbles were generated in the premix liquid, and cavitation was thereby generated.
In Examples 9 to 11 in which the temperature of the premix liquid was lower than the boiling point of cyclopentane, the density of the premix liquid was slightly lower than the original density of the premix liquid, 1.13 kg / cm ² , but there was no further decrease. It can be seen from FIG.

Therefore, as in Examples 9 to 11, a mixture obtained by mixing a premix solution having a temperature of not higher than the boiling point of cyclopentane and not lower than 30 ° C. with an isocyanate solution can suppress cavitation and provide a foamed insulating material. It turns out that it is suitable for the material.

[Examples 12 and 13] Here, the respective temperatures of the premix solution and the isocyanate solution, which are the undiluted solutions of urethane foam, were adjusted to predetermined temperatures and mixed. Were filled into a gap to form a heat insulator, and the heat-insulating properties of this heat-insulating body when applied to a refrigerator were examined.

First, the same raw materials as in Examples 1 and 3 were formulated, and a refrigerator heat insulator composed of urethane foam as a sample was prepared by the following methods (7) to (10). And Comparative Examples 10 and 11 are formed. (7) A polyol, a foam stabilizer, a catalyst, water, and cyclopentane as a liquid foaming agent are mixed based on a predetermined compounding ratio to prepare a premix liquid. (8) The prepared premix liquid and the isocyanate liquid comprising the organic isocyanate are each charged into a raw material tank, adjusted to a predetermined temperature by a heating means, and the two raw liquids are subjected to collision mixing at a predetermined mixing ratio using a high-pressure foaming machine. To prepare a mixture. (9) The mixed liquid is injected into the gap formed by the ABS resin inner box and the steel plate outer box which is the box part of the refrigerator fixed to the foaming jig preheated to 45 ° C., foamed and filled. (See FIG. 2). (10) The filled foam is allowed to stand for 6 minutes, and then a heat insulator composed of the urethane foam is assembled to form a refrigerator 9 as a heat insulating box as shown in FIGS. 5 and 6 (see FIG. 2). ). Then, a heat insulator taken from the refrigerator 9 whose power consumption was measured is used as a sample. The refrigerator used here has an internal volume of 450L.

In Example 12, the same raw materials as in Example 1 were formulated, in Example 13, the same raw materials as in Example 3 were formulated, and in both Examples 12 and 13, the temperature of both stock solutions was reduced to 30 ° C. Adjusted. Comparative Example 10 formulates the same raw materials as in Example 1, Comparative Example 11 formulates the same raw materials as in Example 3,
In both Comparative Examples 10 and 11, the temperature of both stock solutions was adjusted to 20 ° C.

Then, in the refrigerator using the heat insulator of each sample thus formed, the amount of power consumption was measured, and then each refrigerator was disassembled to obtain Y1 to Y8 shown in FIG.
The core density of the foam (density which is the physical property of the core portion obtained by removing both sides of the sample panel by 15 mm), the thermal conductivity and the compressive strength of each of the samples (heat insulators) collected from the positions of Examples 1 to 5 The measurement was performed using the measurement contents described in the above section. The measurement results are shown in Table 8, and the distributions of the core density and the compressive strength are shown in FIGS. The measurement of power consumption is based on JIS-C
Measured according to the power consumption measurement and B method in 9607,
By replacing the door and compressor, measurement errors between samples were eliminated.

[0078]

[Table 8]

As is clear from the distribution diagrams of FIGS. 8 and 9, Examples 12 and 13 show values with substantially uniform core density and compressive strength, while Comparative Examples 10 and 11 show foams injected into the right and left side walls. High values are shown at the back surfaces Y6 and Y7 of the freezing and refrigerating compartments where the front end portions of the urethane foam are combined, and at the bottom surface Y8 as the final filling portion. Table 8
As is clear from FIG.
The core density is higher and the compressive strength is lower than in Examples 2 and 13, which reflects the results of Examples 1 to 5. Further, since the thermal conductivity and the power consumption also show almost the same values, it is suggested that the decrease in the compressive strength relative to the core density is caused by the decrease in the strength of the resin itself.

Therefore, it can be seen that those of Examples 12 and 13 in which the temperature of both the stock solutions was adjusted to 30 ° C. or higher were suitable for urethane foam constituting a heat insulator of a refrigerator.

In the above-described embodiments and examples, the case of using as a heat insulator of a refrigerator is shown. However, the present invention is not limited to this. For example, a heat insulating car, a heat insulating board of a prefabricated refrigerator, a heat insulating board of a showcase. It may be used as a body. In this case as well, the same effects can be obtained, and various modifications can be made without departing from the scope of the invention.

[0082]

As described above, the method for producing a foamed heat insulating material according to the present invention comprises a first undiluted solution comprising an organic isocyanate and a second undiluted solution containing a polyol, a foam stabilizer, a catalyst, a foaming agent and, in some cases, water. And the temperature of the second undiluted solution before mixing is adjusted to be equal to or lower than the boiling point of the foaming agent and equal to or higher than 30 ° C., and the temperature of the mixed solution immediately after mixing both the undiluted solutions is adjusted to be equal to or lower than the boiling point of the foaming agent. In addition, since it is a method of forming a urethane foam as a heat insulating material by impinging and mixing at a temperature of 35 ° C. or more, the increase in viscosity due to resinification is suppressed, the filling property is enhanced, and the gasification of the foaming agent is efficiently performed. This is done to increase liquidity. This makes it possible to obtain a foamed heat insulating material having high filling properties, heat insulating properties and mold release properties, and capable of suppressing the occurrence of cavitation.

In the method for producing a foamed heat insulating material according to the present invention, the temperature of the mixture before mixing the foaming agent of the second undiluted solution is 25 ° C.
With the above method, the viscosity is adjusted to 12000 cps or more, and the temperature of the mixture after mixing the foaming agent is adjusted to the boiling point of the foaming agent or lower, and the viscosity is adjusted to 800 cps or more at 30 ° C. or higher. Even if this is done, enlargement of the size of bubbles is suppressed, and a heat insulating foam having high heat insulating properties can be obtained.

In the method for producing a foamed heat insulating material according to the present invention, since the foaming agent of the second undiluted solution contains a substance containing no chlorine in the molecule, it does not destroy the ozone layer and has no adverse effect on the global environment. The foamed heat insulating material with less amount can be obtained.

In the method for producing a foamed heat insulating material according to the present invention, since the foaming agent of the second stock solution contains cyclopentane and water, a hydrocarbon containing no chlorine in the molecule and having a low global warming potential is used. In addition to reducing the negative impact on the global environment, the use of a heat-insulating foam material that achieves finer cells, suppresses deterioration in thermal conductivity, and has high fluidity and can suppress a decrease in demoldability Obtainable.

In the method for producing a foamed heat insulating material according to the present invention, since the foaming agent of the second undiluted solution contains cyclopentane at 60% or more, deterioration of the heat conductivity is suppressed and a heat insulating foamed material having a high heat insulating property is obtained. be able to.

In the method for producing a foamed heat insulating material according to the present invention, the foaming agent of the second undiluted solution contains cyclopentane having a purity of 60% or more. Can be. This makes it possible to obtain a heat insulating foam having high fluidity, filling properties, heat insulating properties, and high mold release properties.

In the method for producing a foamed heat insulating material according to the present invention, the polyol of the second stock solution is prepared by converting the polyol having a hydroxyl value of 300 to 600 m
Since the substance is in the range of gKOH / g and has a functional group number of 4 or more, it is possible to increase the crosslink density and to obtain a heat-insulating foam material having high releasability.

In the method for producing a foamed heat insulating material according to the present invention, the organic isocyanate of the first stock solution may be a polymethylene polyphenyl polyisocyanate, a mixture of modified polymethylene polyphenyl polyisocyanate and diphenyl methane diisocyanate, or Since a mixture of methylene polyphenyl polyisocyanate and a modified product of polymethylene polyphenyl polyisocyanate is used, a resin composition having excellent reactivity is obtained, and the curing rate of the resin at the time of demolding is increased, and the demolding time is reduced. Foamed heat insulating material that can be obtained.

The method for manufacturing a heat-insulating box according to the present invention is directed to a method for manufacturing a foamed heat-insulating material using the above-described foamed urethane, and a box, a door, or an inner box forming these parts of a refrigerator or a similar product. Injection into the gap between the outer box and filling, and using the formed heat insulator, high filling, heat insulation and fluidity, suppress the occurrence of cavitation and decrease in demolding, global environment The heat insulation box body which can aim at the improvement of a heat insulation property while protecting this can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a manufacturing process when the present invention is carried out.

FIG. 2 is an explanatory view of a manufacturing process when the present invention is carried out.

FIG. 3 is a schematic view showing a sampling position on a prototype urethane foam panel.

FIG. 4 is a cross-sectional view of a high-pressure foaming machine which is a part of equipment for implementing the present invention.

FIG. 5 is a perspective view of a main body of a prototype refrigerator.

FIG. 6 is a longitudinal sectional view of FIG.

FIG. 7 is a schematic diagram showing a sampling position in dismantling a prototype refrigerator.

FIG. 8 is a distribution diagram showing a core density which is a physical property of a sample collected from a prototype refrigerator.

FIG. 9 is a distribution diagram showing compressive strength, which is a property of a sample collected from a prototype refrigerator.

[Explanation of symbols]

9 refrigerator, 10 outer box, 11 inner box, 12 urethane foam.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 75/04 C08L 75/04 F25D 23/08 F25D 23/08 D

Claims (9)

[Claims] 1. A first undiluted solution comprising an organic isocyanate, and a second undiluted solution containing a polyol, a foam stabilizer, a catalyst, a blowing agent and, in some cases, water, are mixed. The temperature of the mixture is adjusted to be not higher than the boiling point of the blowing agent and not lower than 30 ° C.
A method for producing a foamed heat insulating material, wherein the foamed heat insulating material is formed by foaming urethane as a heat insulating material by impact-mixing at a temperature of at least ℃. 2. The temperature of the mixture before mixing the foaming agent of the second stock solution is adjusted to 25 ° C. or higher and the viscosity to 12000 cps or more, and the temperature of the mixture after mixing the foaming agent is adjusted to the foaming agent. The method for producing a foamed heat insulating material according to claim 1, wherein the viscosity is adjusted to 800 cps or more at a boiling point of 30 ° C. or more. 3. The method according to claim 1, wherein the foaming agent of the second undiluted solution contains a substance containing no chlorine in the molecule. 4. The method for producing a foamed heat insulating material according to claim 1, wherein the foaming agent of the second stock solution contains cyclopentane and water. 5. The method according to claim 1, wherein the foaming agent of the second undiluted solution contains 60% or more of cyclopentane. 6. The method according to claim 1, wherein the foaming agent of the second stock solution contains cyclopentane having a purity of 60% or more. 7. The polyol of the second stock solution is a substance having a hydroxyl value in the range of 300 to 600 mg KOH / g and containing four or more functional groups.
7. The method for producing a foamed heat insulating material according to any one of items 6 to 6. 8. An organic isocyanate as the first undiluted solution, comprising polymethylene polyphenyl polyisocyanate, a mixture of modified polymethylene polyphenyl polyisocyanate and diphenylmethane diisocyanate, or polymethylene polyphenyl polyisocyanate and polymethylene polyphenyl. The method for producing a foamed heat insulating material according to any one of claims 1 to 7, wherein the mixture is a mixture of a modified product with a polyisocyanate. 9. An urethane foam produced by the production method according to any one of claims 1 to 8, wherein the urethane foam is a box of a refrigerator or a similar product, a door, or an inner box and an outer box forming these parts. A method for manufacturing a heat-insulating box, comprising using a heat-insulating body formed by filling and filling a gap in a box.