JP2009051997A - Process for producing rigid polyurethane foam by froth method and method for applying rigid polyurethane foam thermal insulation layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for producing a rigid polyurethane foam by froth method that can realize on-site foaming with perfect non-chlorofluorocarbon foam by using a compressed or liquefied inert gas as a foaming agent of a substitute for chlorofluorocarbon and using an apparatus whose safety is in compliance with the High Pressure Gas Safety Law and to provide a method for applying a rigid polyurethane foam thermal insulation layer. <P>SOLUTION: The process for producing a rigid polyurethane foam comprises mixing and jetting a foamable polyol composition containing a foaming agent and a polyisocyanate component by a pouring or spraying apparatus wherein the foaming agent is an inert gas compressed or liquefied to a predetermined pressure and the foamable polyol composition is formed by mixing the inert gas and a polyol composition fed in a fixed quantity. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a rigid polyurethane foam in which a hard polyurethane foam layer is formed by on-site application to a building or a structure by a spray or injection foaming method, and a method of applying a hard polyurethane foam heat insulating layer by an on-site application of spray or injection foaming method. Is.

  Spray foaming is a technology for constructing hard polyurethane foam as a thermal insulation material on the surface of the base, such as warehouses, livestock buildings, tank facilities, etc. that require heat insulation, and roofs, walls, and floors of structures. The law is well known. In the spray foaming method, a technique using an HFC compound, for example, 1,1,1,2-tetrafluoroethane (HFC-134a) as a foaming agent instead of the chlorofluorocarbon compound that destroys the ozone layer is known. Cost is high. A spray foaming method using carbon dioxide as a low-cost foaming agent is also known (Patent Documents 1 and 2, etc.).

  In Patent Documents 1 and 2, the polyol component and carbon dioxide, which are raw materials of the rigid polyurethane foam, are in a supercritical state, a subcritical state, or a liquid state of carbon dioxide both before and after mixing. It is sent to the spray device.

JP 2002-327439 A JP 2003-082050 A

  In the spray foaming method, the foamed stock solution composition, which is a mixture of the foamed polyol composition and the polyisocyanate component discharged from the spray gun, flies toward the substrate while forming a certain spread from the spray nozzle, and foams by adhering.・ Curing. However, according to the techniques disclosed in Patent Documents 1 and 2, since the liquid carbon dioxide is vaporized at the same time as the atmosphere is released at the time of spray foaming, the liquid discharged does not form the desired spray pattern, but the direction other than the spray direction. As a result, it was found that it was difficult to maintain and adjust the spray pattern, and there was room for improvement in workability. Such poor workability is particularly likely to occur immediately after the start of construction and may settle down over time to stabilize the workability, but there is a problem in that the loss of raw materials cannot be avoided and the construction time cannot be shortened. These problems are the same in the case of the injection foaming method.

  This invention uses a compressed or liquefied inert gas as a substitute for fluorocarbons as a foaming agent, and a froth-type rigid polyurethane foam that enables completely non-fluorocarbon foaming on-site by using equipment that complies with the High Pressure Gas Safety Law. It aims at providing the manufacturing method and the construction method of a rigid polyurethane foam heat insulation layer.

  In order to solve the above-mentioned conventional problems, the inventors of the present application have studied a manufacturing method of a floss method rigid polyurethane foam and a construction method of a rigid polyurethane foam heat insulating layer. As a result, it has been found that the object can be achieved by employing the following method, and the present invention has been completed.

  That is, the method for producing a rigid polyurethane foam according to the present invention is a method in which a foamed polyol composition containing a foaming agent and a polyisocyanate component are mixed and discharged by an injection or spray device in order to solve the above-mentioned problems. The foaming agent is an inert gas compressed or liquefied to a predetermined pressure, and the foamed polyol composition is prepared by mixing the inert gas and a polyol composition supplied in a fixed amount. It is characterized by.

  The manufacturing method of the froth method rigid polyurethane foam of the structure which uses the compressed or liquefied inert gas as a foaming agent. This inert gas does not accompany rapid volume expansion during contact mixing with the polyol composition, for example, when liquid carbon dioxide is used as a blowing agent. Thereby, when discharging a foaming polyol composition from a hose, the destabilization of the behavior inside a hose can be suppressed and the stirring efficiency at the time of stirring a foaming polyol composition and a polyisocyanate component can be improved significantly. As a result, the liquid temperature of the foamed polyol composition can be kept low, and the internal heat generation temperature during foaming of the rigid polyurethane foam can be reduced. Therefore, with the above-described configuration, it becomes possible to produce a rigid polyurethane foam by the floss method, which enables in-situ foaming to be completely non-fluorocarbon. In addition, the maintenance and adjustment of the spray pattern by spraying is as easy as when using conventional chlorofluorocarbon, is stable immediately after the start of construction, and the workability can be improved. Therefore, there is little raw material loss and construction time can be shortened.

  In the above-mentioned method for producing a rigid polyurethane foam, the pressure of the inert gas immediately before mixing with the polyol composition is 4-6. When the liquid pressure of the polyol composition is 3.5-6 MPa. 5 MPa is preferred.

  By setting the pressure of the inert gas to 6.5 MPa or less, it is possible to prevent the momentum at the time of discharging the foamed polyol composition from the hose from becoming too large, and to ensure good workability. On the other hand, by setting the pressure of the inert gas to 4 MPa or more, it is possible to prevent the stirring property from being lowered and to maintain normal foaming.

  In the manufacturing method of the above-mentioned froth method rigid polyurethane foam, the inert gas is carbon dioxide gas, carbon dioxide liquefied by cooling is quantitatively supplied by a non-pulsating metering pump, and after passing through the non-pulsating metering pump It is preferable that it is vaporized.

  In Patent Documents 1 and 2, a cylinder type pump is shown as a metering pump for supplying carbon dioxide. However, when such a pump is used, pulsation inevitably occurs, and spraying is stably performed in spraying construction by spraying. Difficult to do. However, since the compressed inert gas can be quantitatively supplied without pulsation by adopting the above-described configuration, stable floss foaming is possible immediately after the start of construction, and the workability can be further improved.

  The hard polyurethane foam heat insulating layer construction method of the present invention is a hard polyurethane foam heat insulating layer construction method in which a foamed polyol composition containing a foaming agent and a polyisocyanate component are mixed or discharged by an injection or spray device. The foaming agent is an inert gas compressed or liquefied to a predetermined pressure, and the foamed polyol composition is obtained by mixing the inert gas and a polyol composition supplied in a fixed amount.

  According to the construction method having such a configuration, since the compressed or liquefied inert gas is used as a foaming agent in a vaporized state, there is no sudden volume expansion during contact mixing with the polyol composition. . Thereby, when discharging a foaming polyol composition from a hose, the destabilization of the behavior inside a hose can be suppressed and the stirring efficiency at the time of stirring a polyol composition and a polyisocyanate component can be improved significantly. As a result, the liquid temperature of the polyol composition can be kept low, and the internal heat generation temperature during foaming can be reduced. Therefore, with the above-described configuration, it is possible to construct a hard polyurethane foam heat insulating layer by a floss method, which enables in-situ foaming to be completely non-fluorocarbon. In addition, the maintenance and adjustment of the spray pattern by spraying (or injection) is as easy as when using conventional chlorofluorocarbons, and is stable immediately after the start of construction. It is possible to form a polyurethane foam insulation layer.

  In the construction method of the hard polyurethane foam heat insulating layer, the pressure of the inert gas immediately before mixing with the polyol composition is 4 to 4 when the liquid pressure of the polyol composition is 3.5 to 6 MPa. It is preferably 6.5 MPa.

  By setting the pressure of the inert gas to 6.5 MPa or less, it is possible to prevent the momentum at the time of discharging the foamed polyol composition from the hose from becoming too large, and to ensure good workability. On the other hand, by setting the pressure of the inert gas to 4 MPa or more, it is possible to prevent the stirring property from being lowered and to maintain normal foaming.

  In the construction method of the hard polyurethane foam heat insulating layer, the inert gas is carbon dioxide gas, and the cooled carbon dioxide liquefied by cooling is quantitatively supplied by a non-pulsating metering pump, and the non-pulsating metering pump It is preferable that it is vaporized after passing.

  Thereby, since it can supply quantitatively without pulsating the inert gas by which compression etc. as a foaming agent was pulsated, stable floss foaming is possible immediately after the start of construction, and workability can be made still better.

  In the present invention, the inert gas used as the foaming agent is, for example, carbon dioxide, nitrogen, rare gas, or the like. In addition, examples of the rare gas include helium, neon, argon, krypton, xenon, and radon. Each illustrated inert gas can be used 1 type or in mixture of 2 or more types. Among the inert gases exemplified above, in the present invention, carbon dioxide is preferable because of its relatively low thermal conductivity and easy handling. Note that chlorofluorocarbon is removed from the inert gas of the present invention. The method for producing a rigid polyurethane foam of the present invention enables non-fluorocarbon froth foaming.

  The pressure of the inert gas is preferably 4 to 6.5 MPa immediately before mixing with the polyol composition when the liquid pressure of the polyol composition is 3.5 to 6 MPa. By setting the pressure to 6.5 MPa or less, it is possible to prevent the momentum when the foamed polyol composition is discharged from the hose from becoming too large, and to ensure good workability. On the other hand, by setting the pressure of the inert gas to 4 MPa or more, it is possible to prevent the stirring property from being lowered and to maintain normal foaming.

For example, when the inert gas is CO ₂ , the flow rate of the inert gas is preferably 20 to 70 g / min, more preferably 30 to 50 g / min immediately before mixing with the polyol composition. preferable. If the flow rate of the inert gas is less than 20 g / min, sufficient foaming cannot be performed, so that a good foam cannot be obtained. On the other hand, if it exceeds 70 g / min, the foam density is lowered and the physical properties of the foam are affected. The flow rate of the inert gas corresponds to the case where the polyol composition is 2 to 4 kg / min (1-1.75 wt% / polyol wt%).

Moreover, it is preferable to use water together as a foaming agent. Although the usage-amount of water is not specifically limited, 0.5-3.5 weight part is preferable with respect to 100 weight part of polyol compositions, and 1-2.5 weight part is more preferable. If the amount of water used is less than 0.5 parts by weight, the amount of carbon dioxide generated by reacting with the polyisocyanate component is reduced, and the resulting foamed synthetic resin may not be reduced in weight. On the other hand, when the amount used exceeds 3.5 parts by weight, the amount of CO ₂ gas generated by reaction with mixing with the polyol composition increases, resulting in an extreme decrease in density and a decrease in strength characteristics of polyurethane foam properties. May occur.

  The polyol composition used in the present invention contains a polyol compound, a catalyst, and a foam stabilizer, and optionally contains known additives in the field of polyurethane foam, such as a crosslinking agent and a flame retardant. A foamed polyol composition is formed by mixing a compressed inert gas, which is a foaming agent, with the polyol composition.

  The liquid temperature of the polyol composition when contacting with the inert gas is preferably 30 to 50 ° C, and more preferably 35 to 40 ° C. When it exceeds 50 ° C., the internal heat generation temperature rises and the rigid polyurethane foam may be burned. On the other hand, when the liquid temperature is lower than 30 ° C., workability may be deteriorated due to an extremely slow foaming speed (reactivity) or a decrease in stirring efficiency due to an increase in the viscosity of the stock solution. By setting the liquid temperature to 30 to 40 ° C., the internal heat generation temperature when foaming the rigid polyurethane foam can be reduced by about 15 to 20 ° C.

  As the polyol compound, known polyol compounds such as polyether polyols and polyester polyols can be used without limitation as polyol compounds for rigid polyurethane foam or isocyanurate foam. As the polyether polyol compound, aliphatic polyether polyol, aliphatic amine polyol, aromatic amine polyol, aromatic polyether polyol and the like are known and can be used. A polyol compound may be used independently and may use 2 or more types together. The polyol compound to be used in combination may be a product prepared by using a single initiator, or a product prepared by mixing an initiator.

  Aliphatic polyether polyols are glycols such as ethylene glycol and 1,4-butanediol, triols such as trimethylolpropane and glycerin, tetrafunctional alcohols such as pentaerythritol, pentafunctional and more polyfunctional alcohols such as sorbitol and sucrose. A polyol compound obtained by ring-opening addition of at least one of ethylene oxide and propylene oxide using at least one low molecular weight polyhydric alcohol selected from polyhydric alcohols as an initiator.

  The hydroxyl value of the aliphatic polyether polyol is preferably 50 to 600 mgKOH / g for a bifunctional and trifunctional polyol compound, and preferably 300 to 600 mgKOH / g for a tetrafunctional or higher polyol compound.

  Examples of the aliphatic amine polyol include alkylene diamine polyols and alkanol amine polyols. These polyol compounds are polyfunctional polyol compounds having terminal hydroxyl groups obtained by ring-opening addition of at least one cyclic ether such as ethylene oxide and propylene oxide using alkylene diamine or alkanol amine as an initiator. As the alkylene diamine, known compounds can be used without limitation. Specifically, use of alkylene diamine having 2 to 8 carbon atoms such as ethylene diamine, propylene diamine, butylene diamine, hexamethylene diamine, and neopentyl diamine is preferable. Among these, the use of alkylenediamine having a small number of carbon atoms is more preferable, and the use of a polyol compound having ethylenediamine or propylenediamine as an initiator is particularly preferable. Examples of the alkanolamine include monoethanolamine, diethanolamine, and triethanolamine. The number of functional groups of the polyol compound using alkylenediamine as the initiator is 4, the number of functional groups of the polyol compound using alkanolamine as the initiator is 3, and the number of functional groups in these mixtures is 3 to 4. The hydroxyl value of the aliphatic amine polyol is preferably 300 to 600 mgKOH / g.

  The aromatic polyether polyol is produced in the same manner as the above-mentioned aliphatic polyether polyol using an aromatic compound such as hydroquinone, bisphenol A, and xylylene glycol as an initiator. The hydroxyl value of the aromatic polyether polyol is preferably 300 to 600 mgKOH / g.

  The aromatic amine polyol is a polyfunctional polyether polyol compound having a terminal hydroxyl group obtained by ring-opening addition of at least one cyclic ether such as ethylene oxide or propylene oxide using an aromatic diamine as an initiator. As the initiator, known aromatic diamines can be used without limitation. Specific examples include 2,4-toluenediamine, 2,6-toluenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, naphthalenediamine and the like. Of these, the use of toluenediamine (2,4-toluenediamine, 2,6-toluenediamine or a mixture thereof) is particularly preferred in that the obtained rigid polyurethane foam has excellent properties such as heat insulation and strength. The number of functional groups of the aromatic amine polyol is 4, and the hydroxyl value is preferably 300 to 600 mgKOH / g.

  The polyester polyol is composed of glycol and aromatic dicarboxylic acid. Examples of the glycol include ethylene glycol, 1,2- to 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, and a poly having an average molecular weight of 150 to 500. An example is oxyethylene glycol. Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid and the like. Such an ester polyol can be produced by the same production method as an ester polyol composed of an aromatic dicarboxylic acid and ethylene glycol or diethylene glycol which are generally used conventionally.

  If necessary, a low molecular weight polyhydric alcohol used in the technical field of polyurethane can be used as the crosslinking agent constituting the polyol composition for rigid polyurethane foam of the present invention. Specifically, trimethylolpropane, glycerin, pentaerythritol, triethanolamine and the like are exemplified.

  In the production of the rigid polyurethane foam of the present invention, in addition to the above components, catalysts, flame retardants, colorants, antioxidants and the like well known to those skilled in the art can be used.

  As the catalyst, tertiary amines such as N-alkylpolyalkylenepolyamines, diazabicycloundecene (DBU), N, N-dimethylcyclohexylamine (Polycat-8), triethylenediamine, N-methylmorpholine, Preference is given to using imidazole derivatives. In addition, it is also preferable to use a catalyst that forms an isocyanurate bond that contributes to improving flame retardancy in the structure of the polyurethane molecule, and examples thereof include fatty acid alkali metal salt catalysts such as potassium acetate and potassium octylate, and quaternary ammonium salt catalysts. .

  In the present invention, it is also a preferable aspect to add a flame retardant, and examples of suitable flame retardants include organic phosphate esters. Organophosphates are suitable additives because they also have an action as a plasticizer and thus have an effect of improving the brittleness of rigid polyurethane foam. It also has the effect of reducing the viscosity of the polyol composition. As such organic phosphoric acid esters, halogenated alkyl esters of phosphoric acid, alkyl phosphoric acid esters, aryl phosphoric acid esters, phosphonic acid esters and the like can be used.

  Next, a preferred embodiment of an apparatus for supplying a foamed polyol composition used in the method for producing a rigid polyurethane foam of the present invention will be described. Hereinafter, carbon dioxide gas will be described as an example of the inert gas. FIG. 1 is a schematic front view showing a preferred embodiment of the foamed polyol composition supply device. The foamed polyol composition supply device includes a cylinder 12 in which liquefied carbon dioxide gas is stored, a carbon dioxide supply device 10, a polyol composition storage device 14, and a polyisocyanate storage device 41 that stores a polyisocyanate component. Yes.

  The carbon dioxide gas is sent from the cylinder 12 to the carbon dioxide supply device 10 through the valve 21 and the pipe 23. The carbon dioxide supply device 10 includes a liquefaction device 16 that cools carbon dioxide and maintains it in a liquid state, and a non-pulsation metering pump 18 that quantitatively sends out liquid carbon dioxide, and the liquefaction device 16 and a non-pulsation metering pump 18 are provided. The pipe 25 to be connected is cooled or insulated and kept cool so that the liquefied carbon dioxide is not vaporized. A cooling device (chiller) for cooling the liquefying device 16 and the pipe 25 is not shown. Carbon dioxide sent from the cylinder 12 to the liquefying device 16 may be any of liquid, gas, and a mixture of liquid and gas. The measured carbon dioxide is sent out through the pipe 27 and mixed with the polyol composition 31. In the pipe 27, carbon dioxide in a liquid state is set within a temperature range described later so that it is completely vaporized and becomes carbon dioxide gas. In FIG. 1, carbon dioxide is configured to be mixed with the polyol composition 31 by switching the flow path with a three-way cock at the point P. When the pipe 26 </ b> A is used, the foamed polyol composition is formed by mixing the carbon dioxide gas and the polyol composition 31 at the junction A to pass through the temperature control device 37, and the foamed polyol composition adjusted to a predetermined temperature. It is sent to the spray device SP (or injection device) through the pipe 39.

  Further, when the pipe 26B is used, the carbon dioxide gas and the polyol composition 31 are mixed at the junction B to form a foamed polyol composition. In this case, the polyol composition 31 passes through the temperature adjusting device 37 and is adjusted to a predetermined temperature, and then mixed with carbon dioxide at the junction B to become a foamed polyol composition, which is sent to the spray device SP through the pipe 39. The foamed polyol composition supplied through the pipe 39 is discharged and mixed with a polyisocyanate component by a spray device (not shown), and sprayed onto the substrate to form a froth-type rigid polyurethane foam.

  The carbon dioxide discharged from the pulsation-free metering pump 18 is completely vaporized in the pipe 27 up to the confluence point A, and the polyol composition is in a gaseous state (either a supercritical state, a subcritical state, or a liquid state). Mixed with the product 31. The piping 27 is not cooled. A commercially available product is used as the non-pulsating metering pump 18. Non-cylinder type is preferable. Mixing of the carbon dioxide gas and the polyol composition 31 can be performed simply by feeding the carbon dioxide gas into the pipe 35 through which the polyol composition 31 flows while the pipe 27 through which the carbon dioxide gas flows is connected. A mixing device such as a static mixer may be further provided downstream of the junction point A.

  The foamed polyol composition is heated to a predetermined temperature before being mixed with the polyisocyanate component. Heating may be performed, for example, at the B position of the polyol composition 31 before mixing with carbon dioxide, or may be performed at the A position in the state of a foamed polyol composition mixed with carbon dioxide. It is more preferable to heat the foamed polyol composition mixed with carbon dioxide at the A position in terms of excellent stability during spray foaming. The temperature of the foamed polyol composition is preferably 50 ° C. or lower and 30 ° C. or higher.

  The filling pressure of the liquefied carbon dioxide gas in the cylinder 12 is preferably 4 to 6 MPa. Moreover, it is preferable that the temperature of the liquefied carbon dioxide gas in the cylinder 12 is 6-22 degreeC.

  Further, the pressure of carbon dioxide from the valve 21 of the cylinder 12 to the non-pulsating metering pump 18 of the carbon dioxide supply device 10 may be substantially liquid by cooling, and is 4 to 7 MPa in consideration of the filling pressure of the cylinder. It is preferable that the pressure is 4.5 to 6.5 MPa. Moreover, it is preferable that it is -20-0 degreeC, and, as for the cooling temperature in the liquefying apparatus 16, it is more preferable that it is -15--5 degreeC.

  As described above, the pressure of the carbon dioxide gas in the pipe 27 from the non-pulsation metering pump 18 to the confluence point A is preferably 3 to 5 MPa, and more preferably 3.5 to 4.5 MPa. The temperature is a temperature at which vaporization is complete, and is adjusted according to the pressure, but is preferably 14 to 30 ° C, and more preferably 20 to 30 ° C. The pressure and temperature of the carbon dioxide gas in the pipe 27 from the non-pulsation metering pump 18 to the confluence point A are set so that fine bubbles of carbon dioxide gas are formed in the foamed polyol composition. As the non-pulsating metering pump 18, it is preferable to use, for example, a non-pulsating metering pump provided with two to three plungers.

  The polyisocyanate component passes through the temperature adjusting device 43 and is adjusted to a predetermined temperature, and is supplied through the pipe 42. The mixing of the foamed polyol composition and the polyisocyanate component is preferably performed, for example, in the case of in-situ foaming, by stirring and mixing with medium pressure discharge (about 5 to 7 MPa). Moreover, as stirring and mixing, stirring and mixing such as a helical rotating type and a rotating type with a pin may be mentioned. During production of the rigid polyurethane foam of the present invention, it is possible to carry out factory production or on-site foaming using an intermediate pressure foaming machine or the like.

The density of the rigid polyurethane foam to polyisocyanurate foam produced by a production method of the present invention (as an insulator) is preferably 50~110kg / ^{m 3,} more preferably 55~90kg / ^{m 3.} The amount of carbon dioxide supplied to achieve the density is 0.3 to 1.5% by weight, more preferably 0.5 to 1.0%, in the foamed stock solution composition (foamed polyol composition + polyisocyanate component). % By weight.

<Example of rigid polyurethane foam production>
(Examples 1 to 3, Comparative Example 1)
A commercially available rigid polyurethane foam stock solution (Sophane-R, polyol 182-1100LC1, Isocyanate S-220NC: manufactured by Toyo Tire & Rubber Co., Ltd.) was used and a froth was sprayed by a spray foaming method using the foaming polyol composition supply apparatus shown in FIG. A method rigid polyurethane foam was prepared. The mixing position of carbon dioxide and the polyol composition was either A or B shown in FIG. The foamed polyol composition and the polyisocyanate component were used at the same temperature. In Comparative Example 1, the pipe 27 was cooled or insulated and kept cool so that the liquefied carbon dioxide was not vaporized. Further, the CO ₂ temperature is a temperature at the outlet of the carbon dioxide supply device 10.

<Evaluation>
(Compressive strength)
It measured based on JISK7220.

(Workability)
It was visually evaluated whether construction could be performed with a predetermined spray pattern from the beginning of construction at the time of injection foaming.

<Evaluation results>
The experimental conditions and evaluation results are shown in Table 1. From this evaluation result, according to the injection foaming method of the present invention, it was possible to form a heat insulating layer of rigid polyurethane foam having predetermined characteristics with good workability. On the other hand, in the comparative example constructed under the condition that carbon dioxide is in a liquid state as a foaming agent, the workability is particularly poor after the start of construction, a lot of raw material loss occurs, and it takes time to adjust the spray or injection conditions. The shortening of construction time was insufficient.

It is the schematic front view which showed suitable embodiment of the foaming polyol composition supply apparatus used for the manufacturing method of the rigid polyurethane foam of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Carbon dioxide supply device 12 Cylinder 14 Polyol composition storage device 16 Liquefaction device 18 Non-pulsation metering pump 21 Valve 23 Piping 25 Piping 26A Piping 26B Piping 27 Piping 31 Polyol composition 35 Piping 37 Temperature control device 39 Piping 41 Polyisocyanate storage device 42 Piping 43 Temperature controller

Claims (6)

A method for producing a rigid polyurethane foam in which a foamed polyol composition containing a foaming agent and a polyisocyanate component are mixed by an injection or spray device and discharged.
The foaming agent is an inert gas compressed or liquefied to a predetermined pressure,
A method for producing a froth-type rigid polyurethane foam, wherein the foamed polyol composition is prepared by mixing the inert gas and a polyol composition supplied in a fixed amount.   The pressure of the inert gas immediately before mixing with the polyol composition is 4 to 6.5 MPa when the liquid pressure of the polyol composition is 3.5 to 6 MPa. Manufacturing method of rigid polyurethane foam.   The inert gas is carbon dioxide gas, carbon dioxide liquefied by cooling is quantitatively supplied by a non-pulsating metering pump, and vaporized after passing through the non-pulsating metering pump. A method for producing a floss-method rigid polyurethane foam according to 1 or 2. A construction method of a hard polyurethane foam heat insulating layer in which a foamed polyol composition containing a foaming agent and a polyisocyanate component are mixed by an injection or spray device and discharged.
The foaming agent is an inert gas compressed or liquefied to a predetermined pressure,
The construction method of the hard polyurethane foam heat insulation layer characterized by mixing the said inert gas and the polyol composition supplied quantitatively, and setting it as the said foaming polyol composition.   The pressure of the inert gas immediately before mixing with the polyol composition is 4 to 6.5 MPa when the liquid pressure of the polyol composition is 3.5 to 6 MPa. Method of hard polyurethane foam insulation layer.   The inert gas is carbon dioxide gas, carbon dioxide liquefied by cooling is quantitatively supplied by a non-pulsating metering pump, and vaporized after passing through the non-pulsating metering pump. The construction method of the hard polyurethane foam heat insulation layer of 4 or 5.

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