JP2022015801A - Foamable composition for polyurethane foam and manufacturing method of polyurethane foam using the same - Google Patents

Abstract

To provide a foamable composition capable of advantageously forming polyurethane foam in which a foam contraction can be effectively suppressed, and also to provide a method for advantageously manufacturing polyurethane foam having excellent dimensional stability while maintaining good thermal insulation performance.SOLUTION: A foamable composition is composed of a polyol composition having a polyol as a main constituent, and a polyisocyanate, and is capable of forming polyurethane foam by reaction between the polyol and the polyisocyanate as well as foaming of a foaming agent. The polyol composition at least includes a halogenated hydroolefin as the foaming agent, and further includes a defoaming agent.SELECTED DRAWING: None

Description

The present invention relates to a foamable composition for polyurethane foam and a method for producing a polyurethane foam using the same, and in particular, a foamable composition capable of advantageously producing a polyurethane foam in which shrinkage of the foam is effectively suppressed. , It relates to a method of producing a polyurethane foam having excellent properties using it.

Conventionally, polyurethane foam has been used mainly as a heat insulating member to insulate interior and exterior wall materials for buildings, panels, etc., as well as heat insulation for metal siding, electric refrigerators, etc., by utilizing its excellent heat insulating properties and adhesiveness. It has been put into practical use for heat insulation of skeleton walls, ceilings, roofs, etc. of apartments and refrigerators, prevention of dew condensation, and heat insulation of liquid infusion pipes, etc. In general, such polyurethane foam is mainly composed of a polyol compound, which is mixed with a foaming agent and, if necessary, various auxiliaries such as a catalyst, a defoaming agent, and a flame retardant, in a polyol compounding solution (premixed solution). It is produced by continuously or intermittently mixing a polyol composition composed of a composition with a polyisocyanate with a mixing device, applying it to a foam forming site, reacting it, and foaming / curing it. ..

By the way, hydrofluorocarbons (HFCs) such as HFC-134a, HFC-245fa, and HFC-365mfc, which are relatively superior in global warming potential, are currently used as foaming agents for producing such polyurethane foams. System foaming agents are known. Although this hydrofluorocarbon-based foaming agent is recognized as an alternative CFC with little or no ozone depletion, in the near future, strong demand for environmental destruction will limit the use of such alternative CFCs. Instead, halogenated hydroolefin-based foaming agents called hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs), which have a low global warming potential due to their chemical instability, are available. , Has been developed.

For example, in Japanese Patent Application Laid-Open No. 2013-500386 (Patent Document 1), HCFO-1233zd, which is one of the halogenated hydroolefin-based foaming agents, is used, and at least one polyester polyol and at least one polyether polyol are used. A technique has been proposed in which a polyurethane foam is formed by forming a composition containing, and reacting, foaming and curing the composition with polyisocyanate. The halogenated hydroolefin-based foaming agent used there has better compatibility with the polyol as compared with the above-mentioned HFC-based foaming agent, and has the property that the foaming agent is difficult to be detached from the system. However, if the polyester polyol and the polyether polyol proposed there are used in combination as a polyol component, a rigid polyurethane foam that exhibits good properties in terms of dimensional stability of the formed foam can be obtained. It was difficult to get.

Further, Japanese Patent Application Laid-Open No. 2016-74885 (Patent Document 2) contains 1-chloro-3,3,3-trifluoropropene as a foaming agent in a polyol composition for rigid polyurethane foam, and is a polyol compound. By containing at least one of a polyether polyol obtained by using an amino group-containing compound as an initiator and a polyether polyol obtained by using a Mannig-based compound as an initiator, curing failure is suppressed and the shrinkage of the polyurethane foam is suppressed. It has been clarified that a polyol composition capable of suppressing the above can be obtained. Further, also in Japanese Patent Application Laid-Open No. 2019-14840 (Patent Document 3), in a foamable composition for polyurethane foam using at least a halogenated hydroolefin as a foaming agent, a polyester polyol and a polyether polyol are used as polyols. By using in combination and constituting 70% by mass or more of the polyether polyol with an ethylenediamine-based polyether polyol, a polyurethane foam having good spraying workability and excellent dimensional stability is formed. It has been clarified that it can be done.

However, in these conventional effervescent compositions for polyurethane foams using halogenated hydroolefins as foaming agents, such effervescent compositions are sprayed onto the foam-forming object according to a usual spraying method. When a thick layer (for example, 50 mm thick) of the target rigid polyurethane foam is formed, there is a problem that the shrinkage of the polyurethane foam becomes large and the dimensional stability of the foam deteriorates. Further, if the density of the polyurethane foam formed is reduced and the content of the foaming agent in the foamable composition is increased in order to reduce the weight thereof, the cell strength of the foam is reduced and the inside of the cell is reduced. There is also an inherent problem that the shrinkage of the polyurethane foam becomes large due to the reduced pressure, and the dimensional stability deteriorates.

Japanese Patent Application Laid-Open No. 2013-500386 Japanese Unexamined Patent Publication No. 2016-74885 Japanese Unexamined Patent Publication No. 2019-14840

Here, the present invention has been made in the background of such circumstances, and the problem to be solved thereof is foaming capable of advantageously forming a polyurethane foam in which shrinkage of the foam can be effectively suppressed. It is in providing a sex composition, and another challenge is to provide a method capable of advantageously producing a polyurethane foam having excellent dimensional stability while maintaining good heat insulating performance. ..

The present invention can be suitably carried out in various aspects as listed below in order to solve the above-mentioned problems. It should be noted that the aspects or technical features of the present invention are not limited to those described below, and can be recognized based on the description of the entire specification and the invention idea disclosed therein. Should be understood.

(1) A foamable composition composed of a polyol composition mainly composed of a polyol and a polyisocyanate, which forms a polyurethane foam by foaming with a foaming agent together with the reaction between the polyol and the polyisocyanate. A foamable composition for polyurethane foam, wherein the polyol composition contains at least a halogenated hydroolefin as the foaming agent, and further contains a foam breaking agent.
(2) The defoaming agent is 0. With respect to 100 parts by mass of the polyol in the polyol composition. The effervescent composition for polyurethane foam according to the above-mentioned mode (1), which is contained in a proportion of 01 to 0.7 parts by mass.
(3) The effervescent composition for polyurethane foam according to the above aspect (1) or the above aspect (2), wherein the defoaming agent is a mixture of cyclic dialkylpolysiloxane and a silicone polymer.
(4) One of the above-mentioned embodiments (1) to (3), wherein the defoaming agent is diluted with a liquid organic phosphoric acid ester and contained in the polyol composition. The foamable composition for polyurethane foams described.
(5) The aspect (1) to the above, wherein the polyester polyol and the polyether polyol are used in combination as the polyol, and the polyether polyol is mainly composed of an ethylenediamine-based polyether polyol. The effervescent composition for polyurethane foam according to any one of the embodiment (4).
(6) The embodiment (6), wherein the halogenated hydroolefin as the foaming agent is contained in the polyol composition at a ratio of 10 to 50 parts by mass with respect to 100 parts by mass of the polyol. The effervescent composition for polyurethane foam according to any one of 1) to (5) above.
(7) Water is further used as the foaming agent together with the halogenated hydroolefin, and the amount of such water is 0. The effervescent composition for polyurethane foam according to any one of the above-mentioned embodiments (1) to (6), which is contained in a proportion of 5 to 4.0 parts by mass.
(8) The invention according to any one of the embodiments (1) to (7), wherein the defoaming agent and the foaming agent are each blended into the polyol composition. Foamable composition for polyurethane foam.
(9) The polyurethane foam according to any one of the above embodiments (1) to (8), wherein the polyurethane foam has a closed cell ratio of 80 to 90%. Effervescent composition.
(10) Using the effervescent composition for polyurethane foam according to any one of the above aspects (1) to (9), the effervescent composition is sprayed onto the surface of a predetermined structure. A method for producing a polyurethane foam, which comprises forming a polyurethane foam layer having a predetermined thickness by foaming and curing.
(11) The production of the polyurethane foam according to the above aspect (10), wherein the reaction time between the polyol composition and the polyisocyanate in the effervescent composition is adjusted to be within 20 seconds. Method.
(12) The method for producing a polyurethane foam according to the embodiment (10) or the embodiment (11), wherein the polyurethane foam layer is formed to have a thickness of 50 mm or more.
(13) The polyuretan foam according to any one of the above embodiments (10) to (12), wherein the polyurethane foam layer has a closed cell ratio of 80 to 90%. Production method.

As described above, in the effervescent composition for polyurethane foam according to the present invention, at least a halogenated hydroolefin is contained as a foaming agent in the polyol composition to be mixed and reacted with polyisocyanate, and further. From where the foaming agent is contained, the polyurethane foam formed by such an effervescent composition is one in which a portion (air bubble or cell) of the foam is defoamed, thereby It is possible to advantageously suppress or avoid decompression in the cells of the foam, whereby the shrinkage of the foam can be effectively suppressed, and the dimensional stability of the foam is improved, in particular. It is possible to significantly contribute to the improvement of the dimensional stability of the rigid polyurethane foam obtained by thick foaming, and it is also possible to advantageously improve the flexibility of the foam.

Moreover, by adding the foam breaking agent to the effervescent composition, the closed cell ratio of the polyurethane foam formed from the effervescent composition is reduced, and the thermal conductivity is reduced according to the decrease in the closed cell ratio. Although the rate also deteriorates, in the foamable composition for polyurethane foam according to the present invention, the closed cell ratio of the foam formed from the effervescent composition is adjusted to be 80 to 90%, whereby the rate is adjusted to be 80 to 90%. The deterioration of the thermal conductivity of the formed foam can be effectively suppressed or prevented, and the good heat insulating performance can be advantageously maintained.

Hereinafter, a specific configuration of an effervescent composition for polyurethane foam according to the present invention and a method for producing a polyurethane foam using the same will be described in detail.

First, the effervescent composition for polyurethane foam according to the present invention is composed of a polyol composition mainly composed of a polyol and polyisocyanate, and is predetermined by a foaming action by a foaming agent together with the reaction between the polyol and the polyisocyanate. A foamable composition that gives polyurethane foam, but the polyol that is the main component constituting the polyol composition used therein is a variety of known polyol compounds that react with polyisocyanate to produce polyurethane, for example. Examples thereof include polyester polyols, polyether polyols, polyolefin-based polyols, acrylic-based polyols, polymer polyols, etc. Among them, it is desirable to use a polyester polyol and a polyether polyol in combination, and further, these two desirable polyols. In addition, it is also possible to use other polyols in combination. The proportion of the polyol in such a polyol composition is about 50 to 80% by mass, preferably about 60 to 70% by mass in total.

Among the above-mentioned polyester polyols and polyether polyols that advantageously constitute the polyols in such a polyol composition, the polyester polyols include polyhydric alcohol-polyhydric carboxylic acid condensation type polyols and cyclic ester open. Known examples such as polyols of the ring polymerization system can be mentioned. Here, as the polyhydric alcohol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol and the like can be used, and among them, the dihydric alcohol is preferably used. Examples of the polyvalent carboxylic acid include succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, isophthalic acid, and anhydrides thereof. Be done. Further, examples of the cyclic ester include ε-caprolactone and the like.

Among them, as the polyester polyol, it is preferable to use an aromatic polyester polyol from the viewpoint of flame retardancy and compatibility, and specifically, it is preferable to use a phthalic acid polyester polyol, and further, such a polyester. It is also effective to combine two or more types of polyols. The phthalic acid-based polyester polyol is a phthalic acid composed of a condensate of phthalic acid, terephthalic acid, isophthalic acid and their anhydrides and dihydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol. A polyester polyol is preferably used. When such a phthalic acid-based polyester polyol is used, even when in-situ foaming is performed at a low temperature (about -10 to 5 ° C.), peeling from the building frame or the like is unlikely to occur, and the foam end after in-situ foaming. There is an advantage that it is possible to obtain a rigid polyurethane foam having flexibility to the extent that the treatment of the portion is relatively easy. In particular, when a hydrofluoroolefin-based foaming agent or a hydrochlorofluoroolefin-based foaming agent is contained, the composition is characterized by having excellent storage stability.

When a plurality of phthalic acid-based polyester polyols are used in combination, it is preferable to combine two types of phthalic anhydride-based polyester polyol and terephthalic acid-based polyester polyol. Phthalic anhydride can be obtained at a low cost, and the polyester polyol obtained from the phthalic anhydride can be produced at a low cost, and has a characteristic of being advantageous in terms of cost. In addition, since it has an aromatic ring, it has excellent flame retardancy and has excellent compatibility with halogenated hydroolefins used as foaming agents. Furthermore, the terephthalic acid-based polyester polyol is more flame-retardant than the phthalic anhydride-based polyester polyol, and has a rigid structure, which contributes to the improvement of dimensional stability. Have. Therefore, by combining two polyester polyols, phthalic anhydride and terephthalic acid, a hard polyurethane foam that is excellent in flame retardancy is advantageous because it moderately dissolves the halogenated hydroolefin which is a foaming agent. It is possible to manufacture it.

On the other hand, it is desirable that 70% by mass or more, preferably 80% by mass or more of the polyether polyol, which is another preferable constituent component of the polyol in the polyol composition, is composed of ethylenediamine-based polyether polyol. .. When the ratio of the ethylenediamine-based polyether polyol in the polyether polyol is less than 70% by mass, the curing rate is lowered, and dripping and lateral running phenomenon are likely to occur during construction, and the foam end portion during spraying work is likely to occur. This is because problems such as peeling occur in the above. Here, as the ethylenediamine-based polyether polyol, ethylenediamine is used as the reaction initiator, and the polyol is obtained by adding an alkylene oxide to the ethylenediamine, and the hydroxyl value is adjusted to 400 to 1000 mgKOH / g. It will be suitably used. Therefore, as the ethylenediamine, a normal ethylenediamine produced by the reaction of ethylene dichloride and ammonia can be used, and as the alkylene oxide, ethylene oxide, propylene oxide, butylene oxide and the like can be used alone or in combination of two or more. However, propylene oxide is advantageously used in view of the price of the raw material and the physical characteristics of the hard foam. If the hydroxyl value of the ethylenediamine-based polyether polyol is less than 400 mgKOH / g, the development of foam strength becomes insufficient, a transverse phenomenon occurs during spraying, and the formed hard foam peels off from the construction surface. There is a risk of Further, when the amount exceeds 1000 mgKOH / g, the flyability becomes large and problems such as scorch generation are likely to occur.

In particular, among the above-mentioned ethylenediamine-based polyether polyols, an ethylenediamine-based polyether polyol having a hydroxyl value of 400 mgKOH / g or more and less than 600 mgKOH / g, and an ethylenediamine-based polyether polyol having a hydroxyl value of 600 mgKOH / g or more and 1000 mgKOH / g or less. It is recommended to use it in combination with a polyol, which can effectively suppress the residual unreacted hydroxyl groups while improving the curing rate, and enjoys the advantage of improving dimensional stability. Can be done. The ethylenediamine-based polyether polyol having a hydroxyl value of 400 mgKOH / g or more and less than 600 mgKOH / g and the ethylenediamine-based polyether polyol having a hydroxyl value of 600 mgKOH / g or more and 1000 mgKOH / g or less are in mass ratio. It is desirable that the mixture is mixed at a ratio of 10:90 to 30:70, preferably 15:85 to 25:75.

Further, the polyether polyol preferably used as one of the polyols in the polyol composition is not only the case where it is composed of the above-mentioned ethylenediamine-based polyether polyol, but also 70% by mass of such an ethylenediamine-based polyether polyol. It is also possible to combine the above with other polyether polyols other than this ethylenediamine-based polyether polyol. The other polyether polyols used therein include Mannig-based polyether polyols, glycerin-based polyether polyols, aromatic polyether polyols, Schklaus-based polyether polyols, sorbitol-based polyether polyols, and toluenediamine-based poly. Examples thereof include ether polyols and tolylene diamine-based polyether polyols.

Above all, in the polyol composition constituting the effervescent composition according to the present invention, it is recommended to use the Mannig-based polyether polyol in combination as another polyether polyol component used together with the ethylenediamine-based polyether polyol. Since the Mannig-based polyether polyol has excellent reaction activity, its use contributes effectively to the promotion of the resinification reaction. Therefore, when sprayed, the curing reaction (resinification) and foaming occur. It is advantageous to prevent the heat of reaction generated by the chemical reaction from being transferred to the adherend exposed to the low temperature environment and being taken away by the adherend, and as a result, the heat of reaction generated is further reduced. It can be effectively used for the curing reaction and the foaming reaction, and the initial foamability can be effectively improved.

The above-mentioned Mannich-based polyether polyol is obtained by utilizing the Mannich reaction, and an alkylene oxide is added to a Mannich condensate having two or more hydroxyl groups in the molecule, or such a Mannich condensate. The added Mannich-based polyether polyol or a mixture thereof. Further, among them, phenols such as a Mannich condensate obtained by reacting phenols, aldehydes and secondary amines, or a Mannich-based polyether polyol obtained by adding an alkylene oxide to such a Mannich condensate are used as a base. The Mannig-based polyether polyol described above will be preferably used.

By the way, the polyester polyol and the polyether polyol as described above constituting the polyol in the polyol composition used in the present invention have a mass ratio of 80:20 to 40:60, preferably 75:25 to 45:55. However, when the proportion of polyester polyol is more than 80% by mass [the proportion of polyether polyol is less than 20% by mass], the curing rate decreases. During spraying work, dripping and lateral running phenomenon may be caused, and problems such as peeling may occur at the end of the foam during spraying work may be caused. In addition, when the proportion of the polyether polyol is more than 60% by mass [the proportion of the polyester polyol is less than 40% by mass], the curing rate is too high and the tip of the spray gun is used during spraying. The foam may harden, causing a gun clogging phenomenon in which spraying cannot be performed in a circular spray pattern, which may cause a problem that it becomes difficult to continue the spraying work.

Then, in the present invention, a polyol composition is prepared by appropriately selecting and using various polyol compounds as described above, and such polyol compositions have conventionally been made of polyurethane. Various additives used in the production of foams, for example, foaming agents (and / or their sources), catalysts, flame retardants, foam stabilizers, etc., are appropriately blended and contained. In particular, as a foaming agent, at least one or more organic foaming agents of halogenated hydroolefins such as HFO and HCFO will be used.

Here, examples of the hydrofluoroolefin (HFO), which is one of the above-mentioned halogenated hydroolefins, include pentafluoropropenes such as 1,2,3,3,3-pentafluoropropene (HFO1225ye), 1, Tetrafluoropropenes such as 3,3,3-tetrafluoropropene (HFO1234ze), 2,3,3,3-tetrafluoropropene (HFO1234yf), 1,2,3,3-tetrafluoropropene (HFO1234ye), 3 , 3,3-Trifluoropropene (HFO1243zf) and other trifluoropropenes, tetrafluorobutene (HFO1345), pentafluorobutene isomers (HFO1354), 1,1,1,4,4,4-hexafluoro Hexafluorobutene isomers (HFO1336) such as -2-butene (HFO1336mzz), heptafluorobutene isomers (HFO1327), heptafluoropentene isomers (HFO1447), octafluoropentene isomers (HFO1438), nona Fluoropentene isomers (HFO1429) and the like can be mentioned. Examples of the hydrochlorofluoroolefin (HCFO) include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf), and the like. Dichlorotrifluoropropene (HCFO1223) and the like can be mentioned.

Further, in the present invention, water as a foaming agent is advantageously used together with the above-mentioned halogenated hydroolefin. As described above, the presence of water in the polyol composition causes the polyol composition and the polyisocyanate to be mixed and reacted, and the water reacts with the polyisocyanate to generate carbon dioxide. At that time, heat of reaction is generated, so that the heat can effectively promote the urethanization reaction and the isocyanurate-forming reaction, and the compressive strength of the obtained polyurethane foam can be further increased. It becomes. Then, due to the presence of water in such a polyol composition, when the polyol composition and the polyisocyanate are mixed and reacted, carbon dioxide is generated by the reaction between the water and the polyisocyanate, and this carbon dioxide is generated. Carbon also contributes to the foaming of polyurethane. Moreover, the combined use of the halogenated hydroolefin and water causes an endothermic reaction when the halogenated hydroolefin volatilizes, but the reaction heat occurs when water reacts with the polyisocyanate to generate carbon dioxide. There is an advantage that the halogenated hydroolefin is easily volatilized by such reaction heat, and thereby there is also an advantage that the amount of the halogenated hydroolefin used can be reduced and the cost thereof can be reduced. It will be.

The amount of the above-mentioned halogenated hydroolefin used is preferably 10 to 50 parts by mass, more preferably 20 to 40 parts by mass with respect to 100 parts by mass of the entire polyol in the polyol composition. .. When the amount of the halogenated hydroolefin used exceeds 50 parts by mass, the core density of the foam becomes low, which may cause a decrease in the strength of the foam and a deterioration in dimensional stability. There is also a problem of disadvantage in terms of cost. On the other hand, if the amount of the halogenated hydroolefin used is less than 10 parts by mass, the characteristics as a foaming agent may not be sufficiently exhibited, the density of the obtained foam may be increased, and the polyol may be increased. The viscosity of the composition becomes high, the mixing property with the polyisocyanate deteriorates, and a problem that a good spray pattern cannot be obtained is caused.

Further, the amount of water used as a foaming agent should be 0.5 to 4 parts by mass, preferably 1 to 3.5 parts by mass with respect to 100 parts by mass of the entire polyol in the polyol composition. , Water is contained. If the amount of this water used is more than 4 parts by mass with respect to 100 parts by mass of the entire polyol, the strength of the foam will rather decrease. The reason is that the urea bond generated by the reaction between water and polyisocyanate increases in the resin, and the polyisocyanate used for the isocyanurate-forming reaction is consumed in the reaction with water, so that the polyisocyanate in the reaction system decreases. Because. Further, if the amount of water used is less than 0.5 parts by mass, there is a problem that the effect as a foaming agent due to the inclusion of water cannot be sufficiently obtained.

As described above, when the halogenated hydroolefin and water are used in combination, the mass ratio of the halogenated hydroolefin and water is 80:20 to 99: 1, preferably 85:15 to 95: 5. It is desirable to use in proportion. If the proportion of water exceeds 20 outside this range, brittleness develops as the reaction progresses, the adhesiveness to the skeleton surface decreases, and problems such as peeling may occur. In addition, carbon dioxide generated by the reaction with polyisocyanate may deteriorate the thermal conductivity and form a foam layer having an insufficient thermal conductivity.

Further, the polyol composition used in the present invention will further contain a defoaming agent in addition to the foaming agent such as the above-mentioned halogenated hydroolefin. This defoaming agent is a component that breaks cells (bubbles) and promotes the formation of open cells when the polyurethane foam is formed. In the present invention, the closed cell ratio of the polyurethane foam is reduced and formed. It is used to suppress or prevent foam shrinkage and improve dimensional stability. Then, such a defoaming agent is adjusted so that the closed cell ratio of the polyurethane foam formed from the effervescent composition according to the present invention is generally 80 to 90%, preferably 82 to 88%. It will be. If the closed cell ratio is lower than 80%, the thermal conductivity of the polyurethane foam deteriorates, and if it is higher than 90%, the dimensional stability of the foam deteriorates. There is a risk of causing it.

By the way, as the defoaming agent, various known defoaming agents can be appropriately selected and used, and specifically, a silicone-based defoaming agent obtained by emulsifying polydimethylsiloxane or a mineral oil is used as a base. Oil-based defoaming agent, higher alcohol-based defoaming agent in which normal-temperature solid higher alcohol is emulsified and dispersed in water, polyether-based defoaming agent using a special polyether that self-emulsifies by water addition, surface activity such as nonionic properties Examples thereof include agent-based defoaming agents and fatty acid ester-based defoaming agents. Further, a defoaming agent having a defoaming action and a defoaming agent having a defoaming action can also be used as the defoaming agent in the present invention. Among them, silicone-based defoaming agents such as oil type, compound type, self-emulsifying type, and emulsion type are particularly preferably used, and among them, a foaming agent composed of a mixture of cyclic dialkylpolysiloxane and a silicone polymer is used. , Will be used advantageously. Specific examples of these cyclic dialkylpolysiloxanes and silicone polymers are given in JP-A-2007-332331, and those disclosed therein can be appropriately used in the present invention. That is, the cyclic dialkylpolysiloxane is produced by a known method, and usually one having an average number of Si—O bonds of 4 to 5 is preferably used, and among them, cyclic dimethylpolysiloxane is preferably used. The silicone polymer is at least 1 selected from the group consisting of (R ¹ ) Si (OR ² ) ₃ , (R ¹ ) ₂ Si (OR ² ) ₂ , and (R ¹ ) ₃ Si (OR ² ). It can be produced by co-hydrolyzing and condensing the seed and Si (OR ² ) ₄ with water and a catalyst to form a polysiloxane bond. R ¹ is an alkyl or phenyl group having 1 or 2 carbon atoms, R ² is an alkyl group having 1 or 2 carbon atoms, and R ¹ and R ² may be the same or different, particularly a methyl group or an ethyl group. Is preferable. Further, there, the mixing ratio of the cyclic dialkylpolysiloxane and the silicone polymer is set to a mass ratio of about 1/9 to 8/2. As the mixture of the cyclic dialkylpolysiloxane and the silicone polymer, a commercially available product can be used, and specifically, F701 (Shin-Etsu Chemical Co., Ltd.) can be exemplified.

Then, in the present invention, such a defoaming agent is used in a ratio of 0.01 to 0.7 parts by mass with respect to 100 parts by mass of the entire polyol in the polyol composition, as described above. A polyurethane foam with the desired closed cell ratio will be formed. If the amount of the defoaming agent used is too small, the problem that the closed cell ratio of the foam is not sufficiently reduced is caused. On the other hand, if the amount used is too large, the closed cell ratio is significantly reduced. There is a risk of causing problems such as deterioration of the thermal conductivity (insulation characteristics) of the foam.

Further, such a defoaming agent is present in the polyol composition in a dissolved or dispersed state, but it is difficult for the defoaming agent to be uniformly dissolved or dispersed in the polyol constituting the polyol composition. In some cases, those diluted with a liquid phosphate ester such as TCPP, which is used as a flame retardant described later, are preferably used.

By the way, in the present invention, the polyol composition constituting the effervescent composition and the polyisocyanate are mixed and reacted in the presence of a catalyst, and at the same time, they are foamed by a foaming agent and cured. , Hard polyurethane foam will be formed, and as one of the catalysts used there, a resinification catalyst for accelerating the reaction between the polyol and the polyisocyanate is advantageously used. It becomes. This resinification catalyst is appropriately selected and used according to the type of foam, and for example, a urethanization catalyst or an isocyanurate-forming catalyst may be used alone or in combination thereof. .. Here, examples of the urethanization catalyst include fatty acid bismuth salts such as dibutyltin dilaurate, bismuth octylate (bismuth 2-ethylhexylate), bismuth neodecanoate, bismuth neododecanoate, and bismuth naphthenate, and lead naphthenate. .. On the other hand, examples of the isocyanurate-forming catalyst include quaternary ammonium salts, fatty acid alkali metal salts such as potassium octylate and sodium acetate, tris (dimethylaminopropyl) hexahydrotriazine and the like. Of these, it is particularly preferable to use a quaternary ammonium salt.

The quaternary ammonium groups (monovalent cations in which four organic groups are covalently bonded to the nitrogen atom) in the quaternary ammonium salt advantageously used here include tetramethylammonium, methyltriethylammonium, and ethyltrimethyl. Ammonium, propyltrimethylammonium, butyltrimethylammonium, pentyltrimethylammonium, hexyltrimethylammonium, heptyltrimethylammonium, octyltrimethylammonium, nonyltrimethylammonium, decyltrimethylammonium, undecyltrimethylammonium, dodecyltrimethylammonium, tridecyltrimethylammonium, tetradecyl Adipose ammonium compounds such as trimethylammonium, heptadecyltrimethylammonium, hexadecyltrimethylammonium, heptadecyltrimethylammonium, octadecyltrimethylammonium, hydroxyammonium such as (2-hydroxypropyl) trimethylammonium, hydroxyethyltrimethylammonium, trimethylaminoethoxyethanol Compounds, 1-methyl-1-azania-4-azabicyclo [2,2,2] octanium, 1,1-dimethyl-4-methylpiperidinium, 1-methylmorpholinium, 1-methylpiperidinium, etc. Examples thereof include alicyclic ammonium compounds. Among these, tetramethylammonium, methyltriethylammonium, ethyltrimethylammonium, butyltrimethylammonium, hexyltrimethylammonium, octyltrimethylammonium, decyltrimethylammonium, dodecyltrimethylammonium, because of their excellent catalytic activity and industrial availability, Tetradecyltrimethylammonium, hexadecyltrimethylammonium, octadecyltrimethylammonium, (2-hydroxypropyl) trimethylammonium, hydroxyethyltrimethylammonium, 1-methyl-1-azania-4-azabicyclo [2,2,2] octanium, and 1 , 1-dimethyl-4-methylpiperidinium will be preferably used.

Further, examples of the organic acid group or inorganic acid group which are monovalent anions which are ionically bonded to such a quaternary ammonium group to form a quaternary ammonium salt include formic acid group, acetic acid group and octyl acid. Group, oxalic acid group, malonic acid group, succinic acid group, glutarate group, adipic acid group, benzoic acid group, toluyl acid group, ethyl benzoic acid group, methyl carbonate group, phenol group, alkylbenzene sulfonic acid group, toluene sulfonic acid group. , Organic acid groups such as benzenesulfonic acid group and phosphoric acid ester group, and inorganic acid groups such as halogen group, hydroxyl group, hydrogencarbonate group and carbonic acid group can be mentioned. Among these, a formic acid group, an acetic acid group, an octylate group, a methyl carbonate group, a halogen group, a hydroxyl group, a hydrogen carbonate group and a carbonic acid group are preferable because they have excellent catalytic activity and are industrially available.

Further, as a catalyst composed of such a quaternary ammonium salt, various catalysts are commercially available, and for example, U-CAT 18X, U-CAT 2313 (manufactured by San-Apro Co., Ltd.), Kaorizer No. 410, Kao Riser No. 420 (manufactured by Kao Corporation) and the like can be mentioned.

The amount of the resinification catalyst used as one of such catalysts is 0.5 to 100 parts by mass with respect to 100 parts by mass of the entire polyol in the polyol composition in order to effectively exert the function as the catalyst. It will be selected within the range of 8 parts by mass, preferably 0.8 to 5 parts by mass. If the amount of this resinification catalyst used is too small, the obtained foam may become sticky, dust, etc. may adhere to it, resulting in a poor appearance, and in the spray foaming operation, droplets adhering to the floor, etc. may be present. Since it becomes sticky, there are problems such as poor workability. On the other hand, if the amount used is too large, heat generation increases during the resinification reaction, causing abnormalities in appearance such as yellowing of the foam. The quaternary ammonium salt catalyst contained in the droplets generated during foaming may worsen the work environment at the work site where the spraying work is being performed.

Further, in addition to the above-mentioned resinification catalyst, if necessary, a known catalyst conventionally used in the production of polyurethane foam is appropriately selected and contained in the polyol composition. .. For example, an amine-based catalyst can advantageously improve the initial foamability of polyurethane, and also has the effect of reducing the overall density of the foam without changing the density difference between the skin layer and the core layer, and further. The stickiness of the foam can be improved to advantageously prevent the deterioration of the appearance due to the adhesion of dust, etc., and in the spray foaming method, the feature of improving the deterioration of workability due to the stickiness of the droplets adhering to the floor, etc. is exhibited. It is something to do. As such an amine-based catalyst, it is recommended to use a reactive amine compound having an OH group or an NH group in the chemical structure, or a cyclic amine compound having a cyclic structure. Among them, the reactive amine compound is recommended. By using it as a catalyst, the odor can be further reduced.

The reactive amine compound or cyclic amine compound used as such an amine-based catalyst can be appropriately selected from known urethanization catalysts. For example, the reactive amine compound includes 2, 4,6-Tri (dimethylaminomethyl) phenol, tetramethylguanidine, N, N-dimethylaminoethanol, N, N-dimethylaminoethoxyethanol, ethoxylated hydroxylamine, N, N, N', N'-tetramethyl -1,3-Diamino-2-propanol, N, N, N'-trimethylaminoethylethanolamine, 1,4-bis (2-hydroxypropyl), 2-methylpiperazine, 1- (2-hydroxypropyl) imidazole , 3,3-Diamino-N-methyldipropylamine, N-methyl-N'-hydroxyethylpiperazine and the like. Examples of the cyclic amine compound include triethylenediamine, N, N'-dimethylcyclohexylamine, N, N-dicyclohexylmethylamine, methylenebis (dimethylcyclohexyl) amine, N, N-dimethylbenzylamine, morpholine, and N-methyl. Morpholine, N-ethylmorpholine, N- (2-dimethylaminoethyl) morpholine, 4,4'-oxydiethylenedimorpholin, N, N'-diethylpiperazine, N, N'-dimethylpiperazine, N- Methyl-N'-dimethylaminoethylpiperazine, 1,8-diazobicyclo (5,4,0) -undecene-7 and the like can be mentioned.

As for the amount of the amine-based catalyst used as one of the catalysts, the function as the catalyst is effectively exhibited, the problems such as odor and deterioration of the working environment are reduced, and the effective foam characteristics are obtained. In order to obtain it, it is in the range of 0.1 to 7 parts by mass, preferably 0.2 to 3 parts by mass, and more preferably 0.3 to 1 part by mass with respect to 100 parts by mass of the entire polyol in the polyol composition. , Will be selected. If the amount of this amine-based catalyst used is less than 0.1 parts by mass, it becomes difficult to fully exert the function as a catalyst, and the obtained foam becomes sticky, dust, etc. adheres, and the appearance deteriorates. In addition, in the spray foaming operation, the droplets adhering to the floor or the like become sticky, which causes problems such as poor workability. Further, when the amount of the amine-based catalyst used is more than 7 parts by mass, the odor of the obtained polyurethane foam becomes remarkable, and the amine-based catalyst volatilized during foaming causes a problem that the spraying work environment is deteriorated. It will be like. Therefore, from the viewpoint of odor, it is preferable that the amount of the amine-based catalyst added is small.

On the other hand, the polyisocyanate constituting the effervescent composition for polyurethane foam according to the present invention together with the above-mentioned polyol composition is blended with the polyol composition and reacts with the polyol in the polyol composition. It is an organic isocyanate compound that produces polyurethane (resin) and has two or more isocyanate groups (NCO groups) in the molecule. For example, diphenylmethane diisocyanate, polymethylenepolyphenylene polyisocyanate, tolylene diisocyanate, polytri Aromatic polyisocyanates such as lentry isocyanate, xylylene diisocyanate, naphthalene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, and urethane prepolymers having an isocyanate group at the molecular terminal. , Isocyanurate modified product of polyisocyanate, Carbodiimide modified product and the like. These polyisocyanate compounds may be used alone or in combination of two or more. In general, polymethylene polyphenylene polyisocyanate (crude MDI) is preferably used from the viewpoints of reactivity, economy, handleability and the like.

The blending ratio of the polyisocyanate and the above-mentioned polyol composition is appropriately determined depending on the type of foam to be formed (for example, polyurethane or polyisocyanurate), but is generally an isocyanate of polyisocyanate. The NCO / OH index (equivalent ratio) indicating the ratio of the group (NCO) to the hydroxyl group (OH) of the polyol in the polyol composition is appropriately determined so as to be in the range of about 0.9 to 2.5. The Rukoto. Above all, it is recommended that the polyol composition and the polyisocyanate are mixed at a volume ratio of 1: 1 to form the desired polyurethane foam.

By the way, in the polyol composition and the polyisocyanate constituting the effervescent composition for polyurethane foam according to the present invention, in addition to the above-mentioned compounding components or contained components, if necessary, a known flame retardant or defoaming agent It is also possible to appropriately select and blend various conventionally known auxiliary agents such as.

The defoaming agent used here is used to uniformly arrange the cell structure of the polyurethane foam, and here, a silicone-based one or a nonionic surfactant is preferably adopted. Specific examples include polyoxyalkylene-modified dimethylpolysiloxane, polysiloxane-oxyalkylene copolymer, polyoxyethylene sorbitan fatty acid ester, castor oil ethylene oxide adduct, lauryl fatty acid ethylene oxide adduct, and the like. One type may be used alone, or two or more types may be used in combination. The blending amount of this defoaming agent is appropriately determined according to the desired foam characteristics, the type of the defoaming agent to be used, and the like, but it is included in 100 parts by mass of the entire polyol in the polyol composition. On the other hand, it is selected in the range of 0.1 to 10 parts by mass, preferably 1 to 8 parts by mass.

Further, as the flame retardant, phosphoric acid esters such as trischloroethyl phosphate, trischloropropyl phosphate, and triethyl phosphate, which have less impact on the environment and also function as a thickener of the effervescent composition, are advantageous. Used for. When this phosphoric acid ester is blended, the blending amount thereof can be appropriately determined depending on the desired foam characteristics, the type of flame retardant, etc., but it is based on 100 parts by mass of the entire polyol in the polyol composition. Generally, it is selected in the range of 5 to 60 parts by mass, preferably 10 to 40 parts by mass. In addition to the above-mentioned phosphoric acid ester, red phosphorus, aluminum hydroxide and the like can be preferably used as the flame retardant. As the flame retardant described above, phosphoric acid esters such as trischloroethyl phosphate, trischloropropyl phosphate, and triethyl phosphate, which have a low environmental load and also function as a thickener for effervescent compositions, are used. , Used to advantage. When this phosphoric acid ester is blended, the blending amount thereof can be appropriately determined depending on the desired foam characteristics, the type of flame retardant, etc., but is generally based on 100 parts by mass of the entire polyol in the polyol composition. It is selected in the range of 5 to 60 parts by mass, preferably 10 to 40 parts by mass.

Further, in the present invention, as the foaming agent, in addition to the above-mentioned halogenated hydroolefin and water, various other known foaming agents such as hydrofluorocarbon (HFC) and hydrocarbon (HC) are used. It can be used in combination as appropriate.

In addition, the effervescent composition for polyurethane foam according to the present invention may further include, if necessary, a formaldehyde scavenger such as urea or melamine, a bubble micronizing agent, a plasticizer, a reinforcing base material, or the like. Various known additives can be appropriately selected and blended.

Then, when the polyol composition obtained as described above and the polyisocyanate are reacted in the presence of a catalyst to foam and cure, various known methods for producing polyurethane foam can be adopted. By the way, for example, a laminated continuous foaming method in which a mixture of these polyol compositions and polyisocyanate is applied onto a face material to foam and cure in the form of a plate, in a space where heat insulation is required, such as an electric refrigerator. Injecting and filling into the honeycomb structure of a lightweight and high-strength board to foam and cure, or spraying from the spray gun head of an on-site foaming machine onto a predetermined adherend (structure) to foam and cure. By the spray foaming method, the foamable composition according to the present invention is foamed and cured to form the desired polyurethane foam.

Further, in the spray foaming method, it is desirable that the reaction time for mixing the polyol composition and the polyisocyanate to form a polyurethane foam is adjusted to be within 20 seconds, and more preferably 10 to 10 seconds. It's 15 seconds. If the reaction time is longer than 20 seconds, problems such as dripping and lateral elongation are caused when the foam is sprayed on the skeleton, and if the reaction time is too short, the gun is clogged or sprayed. Problems such as gas swelling of foam occur, and problems such as a significant decrease in work efficiency are caused. The reaction time is appropriately adjusted depending on the reaction temperature, the type of polyol or polyisocyanate as a reaction component, the amount used thereof, the type of catalyst, the amount used thereof, and the like.

In particular, in the present invention, a spray foaming method in which foaming is performed on-site at an ambient temperature (ambient temperature) is preferably adopted, in which a foaming composition according to the present invention is used on the surface of a predetermined structure. By being sprayed on, foamed and cured, a polyurethane foam layer having a predetermined thickness, particularly a thickness of 50 mm or more, in which the characteristics of the present invention can be advantageously exhibited is formed. By applying to such an in-situ spray foaming method, the features of the present invention are more advantageously exhibited, and thus effective suppression or prevention of foam shrinkage is realized, and further, dimensional stability and the like are realized. Polyurethane foam with excellent properties will be advantageously formed.

Hereinafter, the features of the present invention will be clarified more concretely by showing some examples of the present invention and comparing them with the comparative examples. Needless to say, it is not subject to any restrictions. Further, in addition to the following examples, the present invention is further modified in various ways based on the knowledge of those skilled in the art, as long as it does not deviate from the gist of the present invention, in addition to the above-mentioned specific description. It should be understood that modifications, improvements, etc. can be made. Unless otherwise specified, the percentages (%) and parts shown below are all shown on a mass basis.

Further, the density, foaming characteristics (curing rate), closed cell ratio, workability, dimensional stability and thermal conductivity of the polyurethane foams obtained in the following Examples and Comparative Examples are evaluated as follows. Or measured.

(1) Measurement of Density For the rigid polyurethane foams obtained in each Example and Comparative Example, the respective densities were measured in accordance with JIS-K-7222. That is, five or more 100 mm × 100 mm × 30 mm square test pieces were cut out from a polyurethane foam that was 72 hours or more after foaming and was allowed to stand at 23 ° C ± 2 ° C for 16 hours or more before measurement. rice field. Next, for each test piece, each dimension of length, width, and height was measured three times or more using a caliper, the average value was obtained, and the volume of each test piece was calculated. Then, the mass of each test piece was measured, and the density (ρ) of the test piece was calculated from the following formula. If the density is too high, the polyurethane foam becomes hard and the stability deteriorates. Therefore, 30 kg / m ³ or less was accepted.
ρ (kg / m ³ ) = [m (g) / V (mm ³ )] × 10 ⁶
Here, ρ: density, m: mass of the test piece, V: volume of the test piece.

(2) Measurement of foaming characteristics (curing rate) The polyol composition and crude MDI (Millionate MR-100: manufactured by Tosoh Corporation) as a polyisocyanate are mixed, and the volume ratio of the polyol composition to the polyisocyanate is a polyol. After weighing in a paper cup (capacity: 500 ml) so that the composition / polyisocyanate = 100/100, use a homodisper (manufactured by Tokushu Kagaku Kogyo Co., Ltd.) to stir and mix at high speed for 1 second. Prepared an effervescent mixture for rigid polyurethane foam. Then, the effervescent mixed solution prepared in the paper cup was foamed and cured at room temperature to obtain a rigid polyurethane foam.

Then, the cream time (CT) and the rise time (RT) were measured in order to determine the reactivity of the effervescent mixed solution at the time of such effervescent curing. Here, CT is the time from the start of mixing the polyol composition and the polyisocyanate to the start of foaming, and RT is the time from the start of mixing of the components to the end of foaming. The CT may not be too early or too late, and 2 to 5 seconds is preferable, and RT is said to be early. Then, this RT is the reaction time when the polyol composition and the polyisocyanate are mixed.

(3) Measurement of closed cell ratio The closed cell ratio was measured according to ASTM-D-2856.

(4) Evaluation of workability The polyol composition and crude MDI in each Example and Comparative Example are stirred and mixed using an in-situ spray foaming machine (trade name: A-25, manufactured by Graco) to foam. Along with forming a sex mixture, the effervescent mixture was sprayed onto the surface of a concrete plate of a predetermined size, which is a skeleton, under the condition of an ambient temperature of 15 ° C. to form a foam layer made of rigid polyurethane foam. .. Then, the "workability" at the time of forming the foamed layer was judged from the "initial foamability" and the "shape of the spray pattern" according to the following evaluation criteria.
×: The surface is not smooth because dripping occurs and the spray pattern is not circular. Δ: Slight dripping occurs, the pattern shape changes slightly, and the surface is not smooth. ○: Dripping occurs. The pattern shape does not change, and the surface is smooth.

(5) Evaluation of dimensional stability The dimensional change rate was measured according to the following method according to ASTM-D-2126. First, 25 mm test pieces and 50 mm test pieces were cut out from the foam layer formed by spraying, respectively, using the effervescent compositions prepared in the respective Examples and Comparative Examples as test pieces. Specifically, the 25 mm test piece is collected by cutting out a size of 100 mm × 100 mm × 25 mm so as to include one intermediate skin layer from two foam layers formed with a wall thickness of 30 mm by spraying. Was done. Further, the 50 mm test piece was collected by cutting out a test piece having a size of 100 mm × 100 mm × 50 mm from one foam layer formed with a wall thickness of 60 mm by spraying.

The cut test piece was then allowed to stand at 23 ° C. and 50 RH% for 20 hours, then exposed to 70 ° C. and 95 RH% conditions, and the test piece was removed after 48 hours. Then, the dimensions of the test piece were measured at 5 points for thickness and 3 points for width / length, average values were obtained for each, and the rate of change for each was calculated according to the following formula.
Length change rate ₌ 100 × (lt − l ₀ ) / l ₀
Width change rate = 100 x (b _t -b ₀ ) / b ₀
Thickness change rate = 100 × (δ _t − δ ₀ ) / δ ₀
[L ₀ , b ₀ and δ ₀ : mean value of the first dimension, l _t , b _t and δ _t : mean value of the final dimension after 48 hours]

Then, in the evaluation of dimensional stability, if the three rate of change calculated by the above formula is 10% or more even at one point, it is marked as "x" because good dimensional stability cannot be maintained, and one point. However, those having 5% or more and less than 10% were evaluated as "Δ", all those having less than 5% were evaluated as "○", and those having less than 3% were evaluated as "◎".

(6) Measurement of thermal conductivity For the 25 mm test piece used in the above evaluation of dimensional stability, use a thermal conductivity measuring device: AUTO-A-HC-074 / 200 (manufactured by Eiko Seiki Co., Ltd.) to JIS. -A-1412-2 Annex A (Regulation) A6 of the flat plate comparison method. The thermal conductivity of each test piece was measured according to the measurement method. Then, the obtained thermal conductivity was evaluated according to the following criteria.
◯: 0.023 W / m ・ K or less Δ: 0.023 W / m ・ K or more to 0.026 W / m ・ K or less ×: 0.026 W / m ・ K or more

-Preparation of polyol composition-
As polyols, 750ED (manufactured by Asahi Glass Co., Ltd.), which is an ethylenediamine-based polyether polyol, RDK133 (manufactured by Kawasaki Kasei Kogyo Co., Ltd.), which is a phthalic acid-based polyester polyol, and RFK505 (Kawasaki Kasei Kogyo Co., Ltd.), which is a phthalic acid-based polyester polyol. As a catalyst, Kaorizer No. 420 (manufactured by Kao Co., Ltd.), which is a quaternary ammonium salt, and N, N-dicyclohexylmethylamine (manufactured by Ebonic Japan Co., Ltd.), which is a tertiary amine, are prepared. 12), TOYOCAT-DM70 (manufactured by Toso Co., Ltd.), which is an imidazole-based catalyst, and hexoate lead (manufactured by Toei Kako Co., Ltd.), which is a metal catalyst (Pb), were prepared. Also, cyclic dialkyl as a foam breaking agent. F701 (manufactured by Shin-Etsu Chemical Industry Co., Ltd.), which is a mixture of polysiloxane and silicone polymer, and Dappo SN374 (manufactured by Sannopco Co., Ltd.), which is a fluorine-modified silicone, were prepared. F701 was used as a flame retardant. It was uniformly dispersed in the TCPP to be used as a 10-fold diluted solution (the amount added in the table is the amount of the 10-fold diluted diluted solution). Further, as a flame retardant, Tris (1-chloro-2-propyl) was used. ) Phosphate (TCPP: manufactured by Wanshan) was prepared, and Niax Silicone L-6100 (manufactured by Momentive Performance Materials Japan GK), which is a silicone-based foam stabilizer, was prepared as a foam stabilizer. As a foaming agent, 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd: manufactured by Honeywell), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz:). (Manufactured by Chemours) and water were prepared respectively.

Then, these various polyols, catalysts, defoaming agents, flame retardants, defoaming agents and foaming agents are uniformly mixed in various combinations and blending ratios shown in Tables 1 to 3 below, and Example 1 Various polyol compositions according to 14 and Comparative Examples 1 to 5 were prepared.

-Preparation of polyisocyanate-
Crude MDI (Millionate MR-100: manufactured by Tosoh Corporation) was prepared as a polyisocyanate.

-Manufacturing of polyurethane foam-
The various polyol compositions obtained above and polyisocyanate are used at a volume ratio of 1: 1 and mixed by stirring with an in-situ spray foaming machine (trade name: A-25, manufactured by Graco) to obtain a foaming stock solution. By spraying this on the surface of the inorganic flexible board as an adherend a predetermined number of times under the condition of an atmospheric temperature of 15 ° C. to foam and cure, Examples 1 to 14 and Comparative Examples 1 to 5 are obtained. The various rigid polyurethane foams concerned were produced at predetermined thicknesses, respectively.

Then, using the various polyurethane foams thus obtained, the density, foaming characteristics, closed cell ratio, workability, dimensional stability and thermal conductivity are measured or evaluated, respectively, and the polyurethane foam is also used. The reaction times (CT, RT) at the time of formation of the above were measured, and the obtained results are also shown in Tables 1 to 3 below, respectively.

As is clear from the results of Tables 1 and 2, in the foaming agent composition composed of the combination of the polyol composition and the polyisocyanate adopted in Examples 1 to 14 according to the present invention, the foam breaking agent is used. The closed cell ratio of the polyurethane foam (foam) obtained from such an effervescent composition can be effectively reduced by the addition and inclusion of the foam, and its shrinkage can be suppressed or prevented. As a result, the dimensional change rate evaluated by the dimensional change rate is 3% or less, the dimensional change rate is excellent, the thermal conductivity is small, and therefore the heat insulating property is obtained. It is recognized that excellent polyurethane foam can be obtained.

On the other hand, as shown in the results of Table 3, the polyurethane foam obtained by reacting with polyisocyanate using the polyol compositions according to Comparative Examples 1 to 3 to which the defoaming agent was not added or contained. In each case, the closed cell ratio exceeded 90%, and therefore, in the 50 mm test piece, the shrinkage was remarkable and the dimensional stability was inferior. Further, in Comparative Example 4 in which the amount of water used as a foaming agent was increased, the reaction time was long and the closed cell ratio of the formed polyurethane foam was 70% or less, so that the thermal conductivity was increased. At the same time, the foam shrinks remarkably, lacks dimensional stability, and is poor in workability. Further, in Comparative Example 5 in which the amount of water as a foaming agent was 10 parts with respect to 100 parts of the polyol, the desired polyurethane foam could not be formed.

Claims (13)

A foamable composition composed of a polyol composition mainly composed of a polyol and a polyisocyanate, which forms a polyurethane foam by foaming with a foaming agent together with the reaction between the polyol and the polyisocyanate.
The effervescent composition for polyurethane foam, wherein the polyol composition contains at least a halogenated hydroolefin as the effervescent agent and further contains a defoaming agent. The polyurethane foam according to claim 1, wherein the defoaming agent is contained in a proportion of 0.01 to 0.7 parts by mass with respect to 100 parts by mass of the polyol in the polyol composition. Effervescent composition. The effervescent composition for polyurethane foam according to claim 1 or 2, wherein the defoaming agent is a mixture of cyclic dialkylpolysiloxane and a silicone polymer. The foamability for polyurethane foam according to any one of claims 1 to 3, wherein the defoaming agent is diluted with a liquid organic phosphoric acid ester and contained in the polyol composition. Composition. Any of claims 1 to 4, wherein the polyester polyol and the polyether polyol are used in combination as the polyol, and the polyether polyol is mainly composed of an ethylenediamine-based polyether polyol. The effervescent composition for polyurethane foam according to item 1. Claims 1 to 5, wherein the halogenated hydroolefin as the foaming agent is contained in the polyol composition at a ratio of 10 to 50 parts by mass with respect to 100 parts by mass of the polyol. The foamable composition for polyurethane foam according to any one of the following items. Further water is used as the foaming agent together with the halogenated hydroolefin, and the water is contained in a ratio of 0.5 to 4.0 parts by mass with respect to 100 parts by mass of the polyol in the polyol composition. The foamable composition for polyurethane foam according to any one of claims 1 to 6, wherein the foaming composition is squeezed. The effervescent composition for polyurethane foam according to any one of claims 1 to 7, wherein the defoaming agent and the foaming agent are each blended in the polyol composition. The foamable composition for polyurethane foam according to any one of claims 1 to 8, wherein the polyurethane foam has a closed cell ratio of 80 to 90%. By using the effervescent composition for polyurethane foam according to any one of claims 1 to 9, the effervescent composition is sprayed onto the surface of a predetermined structure to be foamed and cured. A method for producing a polyurethane foam, which comprises forming a polyurethane foam layer having a predetermined thickness. The method for producing a polyurethane foam according to claim 10, wherein the reaction time between the polyol composition and the polyisocyanate in the effervescent composition is adjusted to be within 20 seconds. The method for producing a polyurethane foam according to claim 10 or 11, wherein the polyurethane foam layer is formed with a thickness of 50 mm or more. The method for producing a polyurethane foam according to any one of claims 10 to 12, wherein the polyurethane foam layer has a closed cell ratio of 80 to 90%.