JP2019019302A - Curable composition and polyurethane foam - Google Patents

Abstract

To provide a curable composition that can be foamed satisfactorily and can maintain low thermal conductivity for a long time.SOLUTION: A curable composition contains a polyol compound, an isocyanate compound, a foaming agent, and a filler. The foaming agent contains an unsaturated organic halogen compound, with the filler having an average diameter of 30 μm or less, and the filler having an average aspect ratio of 5 or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a curable composition containing a polyol compound and an isocyanate compound and capable of forming a polyurethane by a curing reaction. Moreover, this invention relates to the polyurethane foam using the said curable composition.

  Polyurethane foam is used as a heat insulating material or the like. When the thermal conductivity of the polyurethane foam is low, it becomes difficult for heat to be transmitted in the polyurethane foam. As a result, the heat insulation can be improved by using the polyurethane foam as a heat insulating material.

  The thermal conductivity of the polyurethane foam includes (1) the thermal conductivity of the polyurethane constituting the polyurethane foam, (2) the thermal conductivity of the blowing agent gas component present in the polyurethane foam, and (3) the thermal conductivity due to radiation. It depends on the rate.

  Conventionally, studies have been widely made to lower the thermal conductivity of polyurethane constituting the polyurethane foam or to lower the thermal conductivity of the blowing agent gas component present in the polyurethane foam.

  For example, Patent Document 1 below discloses a curable composition containing an isocyanate compound and a polyol compound as main components, and further containing a foaming agent and an additive. In Patent Document 1, at least one of hydrochlorofluorocarbon, hydrofluorocarbon, and hydrocarbon is used as the foaming agent.

  Patent Document 2 below discloses a polyurethane foam (rigid polyurethane foam) obtained by reacting an organic polyisocyanate in the presence of a compound having two or more reactive hydrogen atoms, graphite (filler), a foaming agent and a catalyst. ) Is disclosed. In addition, Patent Document 2 below indicates that inorganic and organic fillers may be added in an amount of 0.5 to 50% by weight based on the weight of the compound having two or more organic polyisocyanates and reactive hydrogen atoms. Have been described.

  Patent Document 3 below discloses a polyurethane foam (rigid polyurethane foam) using thermally expandable particles and a filler. Moreover, the following patent document 3 describes that the average particle size of the filler may be about 0.01 to 50 μm. Patent Document 3 below describes that the filler is dispersed on the surface of the thermally expandable particles and the surface of the cell wall.

JP 7-268123 A Japanese Patent Laid-Open No. 11-80539 Special table 2013-539492 gazette

  The blowing agent gas component present in the polyurethane foam diffuses out of the polyurethane foam over time. The blowing agent gas component inside the cells of the polyurethane foam is replaced with air. Thereby, the heat conductivity of a polyurethane foam deteriorates with progress of time. As a method for preventing the diffusion of the blowing agent gas component to the outside of the polyurethane foam, a method of miniaturizing the cell size of the polyurethane foam may be considered.

  In patent document 1, since the specific foaming agent is used, it is disclosed that cell size can be refined | miniaturized. By reducing the cell size, the initial thermal conductivity of the polyurethane foam can be lowered to some extent. However, even if the initial thermal conductivity can be lowered to some extent by the method of miniaturizing the cell size, it is difficult to maintain low thermal conductivity and high thermal insulation over a long period of time.

  On the other hand, in the polyurethane foams described in Patent Documents 2 and 3, since the radiant heat can be suppressed by adding the filler, the initial thermal conductivity can be lowered to some extent. However, it may not be possible to maintain a low thermal conductivity over a long period of time simply by adding a filler. As a result, it may not be possible to maintain high heat insulation over a long period of time.

  The objective of this invention is providing the curable composition which can be made to foam well and can maintain low thermal conductivity over a long period of time. Moreover, this invention is providing the polyurethane foam using the said curable composition.

  According to a wide aspect of the present invention, it contains a polyol compound, an isocyanate compound, a foaming agent, and a filler, the foaming agent contains an unsaturated organic halogen compound, and the filler has an average diameter of 30 μm or less. A curable composition is provided in which the filler has an average aspect ratio of 5 or more.

  On the specific situation with the curable composition which concerns on this invention, content of the said filler is 1 to 13 weight part with respect to a total of 100 weight part of the said polyol compound and the said isocyanate compound.

  On the specific situation with the curable composition which concerns on this invention, the average aspect-ratio of the said filler is less than 40.

  On the specific situation with the curable composition which concerns on this invention, the said filler is an inorganic mineral.

  In a specific aspect of the curable composition according to the present invention, the filler is graphite or mica.

  In a specific aspect of the curable composition according to the present invention, the foaming agent further contains water or a saturated organic halogen compound.

  In a specific aspect of the curable composition according to the present invention, the unsaturated organic halogen compound is a hydrochlorofluoroolefin or a hydrofluoroolefin.

  According to a wide aspect of the present invention, there is provided a polyurethane foam in which the above-described curable composition is foamed.

  The curable composition according to the present invention includes a polyol compound, an isocyanate compound, a foaming agent, and a filler, the foaming agent includes an unsaturated organic halogen compound, and the average diameter of the filler is 30 μm or less. Since the filler has an average aspect ratio of 5 or more, it can be foamed well, and a low thermal conductivity can be maintained over a long period of time.

FIG. 1 is a diagram for explaining a method of calculating a cell average diameter.

  Hereinafter, the present invention will be described in detail.

  The curable composition concerning this invention contains a polyol compound, an isocyanate compound, a foaming agent, and a filler. In the curable composition which concerns on this invention, the said foaming agent contains an unsaturated organic halogen compound, the average diameter of the said filler is 30 micrometers or less, and the average aspect-ratio of the said filler is 5 or more. In the curable composition according to the present invention, a specific filler is used.

  In this invention, since said structure is provided, it can be made to foam favorably and low thermal conductivity can be maintained over a long period of time. In this invention, it can be made to foam favorably so that a closed cell rate may become high. In the present invention, the thermal conductivity of the polyurethane foam formed by the curable composition can be kept low over a long period of time. Moreover, in this invention, the heat insulation of the said polyurethane foam can be maintained highly over a long period of time.

  In the present invention, since the specific filler is used, the filler effectively acts as a nucleating agent for forming bubbles during foaming, and the cell size can be reduced. As a result, in the present invention, the initial thermal conductivity of the polyurethane foam can be lowered. Furthermore, in the present invention, since the specific filler is used, the filler is likely to be dispersed on the surface of the cell wall of the polyurethane foam. As a result, in the present invention, it is considered that the gas barrier property of the cell is improved, and the diffusion of the foaming agent gas component to the outside of the polyurethane foam is suppressed. Thereby, it is thought that the heat conductivity of a polyurethane foam is maintained low over a long period of time.

  Hereinafter, details of components contained in the curable composition according to the present invention will be described.

[Polyol compound]
Examples of the polyol compound contained in the curable composition include polylactone polyol, polycarbonate polyol, aromatic polyol, alicyclic polyol, aliphatic polyol, polyester polyol, and polyether polyol. The polyol compound may be a polymer polyol. As for the said polyol compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the polylactone polyol include polypropiolactone glycol, polycaprolactone glycol, and polyvalerolactone glycol.

  Examples of the polycarbonate polyol include a dealcoholization reaction product of a hydroxyl group-containing compound and a carbonate compound. Examples of the hydroxyl group-containing compound include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, and nonanediol. Examples of the carbonate compound include diethylene carbonate and dipropylene carbonate.

  Examples of the aromatic polyol include bisphenol A, bisphenol F, phenol novolac, and cresol novolac.

  Examples of the alicyclic polyol include cyclohexanediol, methylcyclohexanediol, isophoronediol, dicyclohexylmethanediol, and dimethyldicyclohexylmethanediol.

  Examples of the aliphatic polyol include ethylene glycol, propylene glycol, butanediol, pentanediol, and hexanediol.

  Examples of the polyester polyol include a dehydration condensate of a polybasic acid and a polyhydric alcohol, a ring-opening polymerization product of a lactone, a condensate of a hydroxycarboxylic acid and a polyhydric alcohol, and the like. Examples of the polybasic acid include adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, and succinic acid. Examples of the polyhydric alcohol include bisphenol A, ethylene glycol, propylene glycol, butanediol, diethylene glycol, hexane glycol, and neopentyl glycol. Examples of the lactone include ε-caprolactone and α-methyl-ε-caprolactone. Examples of the hydroxycarboxylic acid include castor oil and a reaction product of castor oil and ethylene glycol.

  Examples of the polyether polyol include a ring-opening polymer of an active hydrogen compound having 2 or more active hydrogen atoms and an alkylene oxide. Examples of the alkylene oxide include ethylene oxide, propylene oxide, and tetrahydrofuran. The molecular weight of the active hydrogen compound is preferably low. Examples of the active hydrogen compounds include diol compounds such as bisphenol A, ethylene glycol, propylene glycol, butylene glycol, and 1,6-hexanediol; triol compounds such as glycerin and trimethylolpropane; amines such as ethylenediamine and butylenediamine. Compounds and the like.

  Examples of the polymer polyol include graft polymers obtained by graft polymerization of unsaturated organic compounds to polyol compounds, polybutadiene polyols, modified polyols of polyhydric alcohols, and hydrogenated products thereof.

  In the graft polymer, examples of the polyol compound include aromatic polyols, alicyclic polyols, aliphatic polyols, polyester polyols, and polyether polyols. Examples of the unsaturated organic compound include acrylonitrile, styrene, and methyl (meth) acrylate.

  Examples of the modified polyol of the polyhydric alcohol include a reaction modified product of a polyhydric alcohol and an alkylene oxide. Examples of the polyhydric alcohol include trihydric alcohols such as glycerin and trimethylolpropane; pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol, sucrose, glucose, mannose, fructose, methyl glucoside, and derivatives thereof. 4 to 9 alcohols: phenol, phloroglucin, cresol, pyrogallol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol S, 1-hydroxynaphthalene, 1,3,6,8-tetrahydroxynaphthalene, anthrol Phenol compounds such as 1,4,5,8-tetrahydroxyanthracene and 1-hydroxypyrene; polybutadiene polyol; castor oil polyol; Kill (meth) acrylate (co) polymers; polyfunctional (e.g. two functional groups to 100) polyol such as polyvinyl alcohol; condensates of phenol and formaldehyde (novolac), and the like. Examples of the alkylene oxide include alkylene oxides having 2 to 6 carbon atoms. Specific examples of the alkylene oxide include ethylene oxide, 1,2-propylene oxide, 1,3-propyloxide, 1,2-butylene oxide, 1,4-butylene oxide, and the like. From the viewpoint of improving properties and reactivity, the alkylene oxide is preferably 1,2-propylene oxide, ethylene oxide or 1,2-butylene oxide, and is 1,2-propylene oxide or ethylene oxide. It is more preferable. As for the said alkylene oxide, only 1 type may be used and 2 or more types may be used together.

  When two or more alkylene oxides are used, the form of addition may be block addition, random addition, or both block addition and random addition.

  From the viewpoint of increasing the effect of reducing the total calorific value during combustion, the polyol compound is preferably a polyester polyol or a polyether polyol, more preferably a polyester polyol, and a molecular weight of 300 or more and 500 or less. More preferably, it is a certain polyester polyol.

[Isocyanate compound]
As an isocyanate compound contained in the said curable composition, aromatic polyisocyanate, alicyclic polyisocyanate, aliphatic polyisocyanate, etc. are mentioned. From the viewpoint of efficiently proceeding the curing reaction, the isocyanate compound is preferably a polyisocyanate compound. As for the said isocyanate compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the aromatic polyisocyanate include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, and polymethylene polyphenyl polyisocyanate.

  Examples of the alicyclic polyisocyanate include cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and dimethyldicyclohexylmethane diisocyanate.

  Examples of the aliphatic polyisocyanate include methylene diisocyanate, ethylene diisocyanate, propylene diisocyanate, tetramethylene diisocyanate, and hexamethylene diisocyanate.

  The isocyanate compound is preferably polymethylene polyphenyl polyisocyanate because it is easily available and is convenient.

  The polyol compound and the isocyanate compound can be used in an appropriate amount so as to efficiently form a urethane bond. From the viewpoint of increasing the reaction efficiency, the content of the isocyanate compound is preferably 100 parts by weight or more, more preferably 120 parts by weight or more, preferably 450 parts by weight or less, more preferably 100 parts by weight of the polyol compound. Is 400 parts by weight or less.

[Foaming agent]
A foaming agent is a substance that generates a gas upon decomposition or a substance that itself becomes a gas.

  Examples of the foaming agent contained in the curable composition include water, saturated organic halogen compounds, and unsaturated organic halogen compounds. The curable composition contains at least an unsaturated organic halogen compound as a foaming agent. Moreover, it is preferable that the said curable composition contains an unsaturated organic halogen compound and water or a saturated organic halogen compound as a foaming agent.

  In the saturated organic halogen compound and the unsaturated organic halogen compound, all of the hydrogen atoms may be substituted with halogen atoms, or some of the hydrogen atoms may be substituted with halogen atoms.

  Since the said curable composition contains an unsaturated organic halogen compound as a foaming agent, the foamability at the time of formation of a polyurethane foam can be made favorable, and the thermal conductivity of a polyurethane foam can be maintained low over a long period of time.

  When the curable composition contains an unsaturated organic halogen compound and water as a foaming agent, or contains an unsaturated organic halogen compound and a saturated organic halogen compound, the foamability at the time of forming a polyurethane foam is further improved. And the thermal conductivity of the polyurethane foam can be kept low for a longer period of time.

  Examples of the unsaturated organic halogen compounds include unsaturated organic chlorine compounds, unsaturated organic fluorine compounds, unsaturated organic bromine compounds, and unsaturated organic iodine compounds. As for the said foaming agent, only 1 type may be used and 2 or more types may be used together.

  Examples of the unsaturated organic fluorine compound include hydrofluoroolefin. Examples of the hydrofluoroolefin include 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze) (E and Z isomers), and 1 1,1,4,4,4-hexafluoro-2-butene (HFO1336mzz) (E and Z isomers) and the like.

  Further, examples of the unsaturated organic fluorine compound include compounds having a chlorine atom, a fluorine atom and a double bond. Examples of the compound having a chlorine atom, a fluorine atom and a double bond include 1,2-dichloro-1,2-difluoroethene (E and Z isomers), hydrochlorofluoroolefin and the like. Examples of the hydrochlorofluoroolefin include 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) (E and Z isomers), 1-chloro-2,3,3-trifluoropropene (HCFO-). 1233yd) (E and Z isomers), 1- (4) chloro-1,3,3-trifluoropropene (HCFO-1233zb) (E and Z isomers), 2-chloro-1,3,3-tri Fluoropropene (HCFO-1233xe) (E and Z isomers), 2-chloro-2,2,3-trifluoropropene (HCFO-1233xc), 2-chloro-3,3,3-trifluoropropene (HCFO- 1233xf), 3-chloro-1,2,3-trifluoropropene (HCFO-1233ye) (E and Z isomers), 3-chloro-1,1,2 Trifluoropropene (HCFO-1233yc), 3,3-dichloro-3-fluoropropene, 1,2-dichloro-3,3,3-trifluoropropene (HCFO-1223xd) (E and Z isomers), 2- Chloro-1,1,1,4,4,4-hexafluoro-2-butene (E and Z isomers), and 2-chloro-1,1,1,3,4,4,4-heptafluoro- 2-butene (E and Z isomers) and the like.

  From the viewpoint of improving the foamability during the formation of the polyurethane foam and maintaining the thermal conductivity of the polyurethane foam low for a longer period of time, the unsaturated organic halogen compound is hydrochlorofluoroolefin or hydrofluoroolefin. Preferably there is.

  When the curable composition contains the unsaturated organic fluorine compound as a foaming agent, when only the saturated organic halogen compound is used as the foaming agent, and an unsaturated organic halogen other than the unsaturated organic fluorine compound as the foaming agent It has been confirmed that the thermal conductivity of the polyurethane foam can be kept lower for a longer period of time compared to the case where the compound is used.

  Examples of the saturated organic halogen compound include saturated organic chlorine compounds, saturated organic fluorine compounds, saturated organic bromine compounds, and saturated organic iodine compounds. From the viewpoint of improving the foamability during formation of the polyurethane foam and maintaining the thermal conductivity of the polyurethane foam low for a longer period of time, the saturated organic halogen compound is a saturated organic chlorine compound or a saturated organic fluorine compound. Preferably there is.

  Examples of the saturated organic chlorine compound include dichloroethane, propyl chloride, isopropyl chloride, butyl chloride, isobutyl chloride, pentyl chloride, and isopentyl chloride. From the viewpoint of improving the foamability at the time of forming the polyurethane foam and maintaining the thermal conductivity of the polyurethane foam low for a long period of time, the saturated organic chlorine compound is a saturated organic chlorine compound having 2 to 5 carbon atoms. It is more preferable that

  Examples of the saturated organic fluorine compound include hydrofluorocarbon. Examples of the hydrofluorocarbon include difluoromethane (HFC32), 1,1,1,2,2-pentafluoroethane (HFC125), 1,1,1-trifluoroethane (HFC143a), 1,1,2,2- Tetrafluoroethane (HFC134), 1,1,1,2-tetrafluoroethane (HFC134a), 1,1-difluoroethane (HFC152a), 1,1,1,2,3,3,3-heptafluoropropane (HFC227ea) ), 1,1,1,3,3-pentafluoropropane (HFC245fa), 1,1,1,3,3-pentafluofane (HFC365mfc) and 1,1,1,2,2,3,4 , 5,5,5-decafluoropentane (HFC4310mee) and the like.

  In consideration of foamability, the foaming agent can be used in an appropriate content. The content of the foaming agent (the total content when using a plurality of foaming agents) is preferably 0.1 parts by weight or more, more preferably 100 parts by weight in total of the polyol compound and the isocyanate compound. Is 0.5 parts by weight or more, more preferably 0.7 parts by weight or more, particularly preferably 1 part by weight or more, preferably 50 parts by weight or less, more preferably 40 parts by weight or less, still more preferably 20 parts by weight or less. The amount is preferably 18 parts by weight or less. When the content of the foaming agent is not less than the above lower limit, foaming is promoted, and a polyurethane foam having a low density is favorably formed. When the content of the foaming agent is not more than the upper limit, inhibition of foaming by the foaming agent is suppressed.

  The content of the unsaturated organic halogen compound is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, and still more preferably 0 with respect to 100 parts by weight of the total of the polyol compound and the isocyanate compound. 0.7 parts by weight or more, particularly preferably 1 part by weight or more, preferably 50 parts by weight or less, more preferably 40 parts by weight or less, still more preferably 20 parts by weight or less, particularly preferably 18 parts by weight or less, and most preferably 15 parts by weight. Or less. When the content of the unsaturated organic halogen compound is not less than the above lower limit, foaming is promoted, and a polyurethane foam having a small density is favorably formed. When the content of the unsaturated organic halogen compound is not more than the above upper limit, inhibition of foaming by the unsaturated organic halogen compound can be suppressed.

  In the case of using an unsaturated organic halogen compound and water as the foaming agent, water can be used in an appropriate content in consideration of foamability. The water content is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, preferably 20 parts by weight or less, more preferably 100 parts by weight in total of the polyol compound and the isocyanate compound. Is 18 parts by weight or less, more preferably 15 parts by weight or less, and particularly preferably 0.7 parts by weight or less. When the water content is not less than the above lower limit, foaming is promoted, and a polyurethane foam having a low density is favorably formed. When the water content is not more than the above upper limit, inhibition of foaming by water can be suppressed.

  When using an unsaturated organic halogen compound and a saturated organic halogen compound as the foaming agent, the saturated organic halogen compound can be used in an appropriate content in consideration of foamability. The content of the saturated organic halogen compound is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, preferably 20 parts by weight or less with respect to 100 parts by weight of the total of the polyol compound and the isocyanate compound. More preferably, it is 18 parts by weight or less, further preferably 15 parts by weight or less, and particularly preferably 10 parts by weight or less. When the content of the saturated organic halogen compound is not less than the above lower limit, foaming is promoted and a polyurethane foam having a small density is favorably formed. When the content of the saturated organic halogen compound is not more than the above upper limit, an increase in cell size due to the saturated organic halogen compound can be suppressed.

[Filler]
The filler is well dispersed on the surface of the cell wall in the polyurethane foam.

  The filler contained in the curable composition includes phosphate, sediment, ash, metal oxide, metal hydroxide, carbonate, mineral, sulfate, magnetic powder, silicate, nitride, carbide, boron. And fluorides, fibrous materials and the like. Specifically, phosphates such as inorganic phosphorus compounds; deposits such as diatomaceous earth; ash such as fly ash; metals such as silica, alumina, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, and antimony oxide Oxides: Metal hydroxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide; carbonates such as basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, barium carbonate; dosonite, hydrotalcite, silicon carbide Minerals such as calcium mineral, barium sulfate and magnesium sulfate; magnetic powders such as calcium silicate, potassium silicate, zinc borate and ferrite; silicates such as glass beads and silica balloons; Nitride such as aluminum nitride, boron nitride, silicon nitride Carbides such as carbon black, graphite, hollow carbon particles charcoal powder; titanium oxides such as potassium titanate and lead zirconate titanate; borides such as aluminum borate; sulfides such as molybdenum sulfide; carbon fibers and gypsum fibers And fibrous materials such as glass fiber, stainless steel fiber, slag fiber, silica alumina fiber, alumina fiber, silica fiber, and zirconia fiber.

  The filler is preferably an inorganic mineral because it is inexpensive and easily available in large quantities and can form a good polyurethane foam.

  From the viewpoint of keeping the thermal conductivity of the polyurethane foam low over a long period of time, the average diameter of the filler is 30 μm or less. From the viewpoint of keeping the thermal conductivity of the polyurethane foam low for an even longer period, the average diameter of the filler is preferably 0.1 μm or more, preferably 10 μm or less, more preferably 5 μm or less. When the average diameter of the filler is not less than the above lower limit, the filler hardly aggregates and the filler is well dispersed. When the average diameter of the filler is less than or equal to the above upper limit, the filler is difficult to break through the cell when the polyurethane foam is formed, and the polyurethane foam is in a more favorable foamed state. When the filler is difficult to break through the cell, the foaming agent gas component is difficult to diffuse, and the thermal conductivity of the polyurethane foam is effectively lowered. When the polyurethane foam is in a well-foamed state, the closed cell ratio of the polyurethane foam tends to be high.

  The average diameter of the filler is an average diameter measured on a number basis, and is a median diameter (D50) value of 50%. The average diameter can be measured by a laser diffraction / scattering method, an image analysis method, a Coulter method, a centrifugal sedimentation method, or the like. Measurement by laser diffraction / scattering method is preferred.

  From the viewpoint of keeping the thermal conductivity of the polyurethane foam low over a long period of time, the average aspect ratio of the filler is 5 or more. From the viewpoint of keeping the thermal conductivity of the polyurethane foam low for a longer period of time, the average aspect ratio of the filler is preferably less than 40. When the average aspect ratio is less than the lower limit, the foaming agent gas component is hardly retained in the cell, and the thermal conductivity of the polyurethane foam may not be maintained low. When the average aspect ratio is less than the above upper limit, the filler is unlikely to break through the cells when the polyurethane foam is formed, and the polyurethane foam is in a more favorable foamed state.

  The aspect ratio is a ratio of the average diameter of the filler to the average thickness of the filler (average diameter of filler / filler thickness). The aspect ratio can be measured by a water surface particle film method or the like. The average aspect ratio is an average of the aspect ratios of a plurality of fillers.

  Examples of the method for obtaining the aspect ratio from the water surface particle film method include the following examples.

  After hydrophobizing a plurality of fillers, the weight is measured, and the filler volume is calculated from the known filler density. Float the filler in water and determine the surface area of the filler. The average thickness is calculated from the volume and the surface area. When the weight of the hydrophobized filler is w, the density is d, the volume is V, the area is S, and the average thickness is l, the average thickness of the filler can be calculated by the following formula.

  l = V / S = w / (d · S)

  From the viewpoint of keeping the thermal conductivity of the polyurethane foam low over a long period of time, the content of the filler is preferably 1 part by weight or more, more preferably 100 parts by weight in total for the polyol compound and the isocyanate compound. Is 2 parts by weight or more, more preferably 3 parts by weight or more, preferably 13 parts by weight or less, more preferably 10 parts by weight or less, and still more preferably 8 parts by weight or less. Further, when the content of the filler is not less than the above lower limit, the foaming agent gas component is difficult to diffuse, and the thermal conductivity of the polyurethane foam is effectively lowered. When the content of the filler is less than or equal to the above upper limit, the filler is difficult to break through the cells when the polyurethane foam is formed, and the polyurethane foam is in a more favorable foamed state. When the content of the filler is not less than the above lower limit and not more than the above upper limit, the cell average diameter of closed cells can be made relatively small.

[catalyst]
The catalyst accelerates the polyurethane reaction. The curable composition preferably contains a catalyst. Examples of the catalyst include a urethanization catalyst and a trimerization catalyst.

  The urethanization catalyst promotes the formation of urethane bonds by promoting the reaction between the hydroxyl group of the polyol compound and the isocyanate group of the isocyanate compound.

  Examples of the urethanization catalyst include amine catalysts. Examples of the amine catalyst include triethylamine, N-methylmorpholine bis (2-dimethylaminoethyl) ether, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, N, N, N′-trimethylamino. Examples include ethyl-ethanolamine, bis (2-dimethylaminoethyl) ether, N-methyl, N′-dimethylaminoethylpiperazine, and imidazole compounds in which the secondary amine functional group in the imidazole ring is substituted with a cyanoethyl group. It is done. As for the said urethanization catalyst, only 1 type may be used and 2 or more types may be used together.

  The urethanization catalyst can be used in an appropriate content so that the polyol compound and the isocyanate compound react well. The content of the urethanization catalyst is preferably 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, preferably 10 parts by weight or less with respect to a total of 100 parts by weight of the polyol compound and the isocyanate compound. The amount is more preferably 8 parts by weight or less, still more preferably 6 parts by weight or less, and particularly preferably 5 parts by weight or less. When the content of the urethanization catalyst is not less than the above lower limit, the urethane bond effectively proceeds. When the content of the urethanization catalyst is not more than the above upper limit, an appropriate foaming rate can be maintained, and the moldability tends to be good.

  The trimerization catalyst promotes the trimerization reaction of the isocyanate group of the isocyanate compound and promotes the formation of an isocyanurate ring. Further, the trimerization catalyst suppresses expansion of the polyurethane foam during combustion.

  Examples of the trimerization catalyst include aromatic compounds, alkali metal salts of carboxylic acids, quaternary ammonium salts of carboxylic acids, and quaternary ammonium salts / ethylene glycol mixtures. Examples of the aromatic compound include tris (dimethylaminomethyl) phenol, 2,4-bis (dimethylaminomethyl) phenol, and 2,4,6-tris (dialkylaminoalkyl) hexahydro-S-triazine. Examples of the alkali metal salt of the carboxylic acid include potassium acetate and potassium 2-ethylhexanoate. As for the said trimerization catalyst, only 1 type may be used and 2 or more types may be used together.

  The trimerization catalyst can be used in an appropriate content so that the trimerization reaction is favorably promoted. The content of the trimerization catalyst is preferably 0.01 parts by weight or more, more preferably 1 part by weight or more, still more preferably 3 parts by weight or more, with respect to 100 parts by weight of the total of the polyol compound and the isocyanate compound. The amount is preferably 10 parts by weight or less. When the content of the trimerization catalyst is not less than the above lower limit, the expansion of the polyurethane foam is easily suppressed during the formation of the polyurethane foam. When the content of the trimerization catalyst is less than or equal to the above upper limit, urethanization and trimerization of isocyanate groups proceed with an appropriate balance, and foaming defects are less likely to occur.

[Flame retardants]
A flame retardant is a substance that can impart flame retardancy to a flammable substance such as plastic, wood, fiber, and the like.

  It is preferable that the said curable composition contains a flame retardant. Examples of the flame retardant include nitrogen-containing non-halogen flame retardant, red phosphorus, phosphate ester, phosphate-containing flame retardant, bromine-containing flame retardant, boron-containing flame retardant, antimony-containing flame retardant, and metal hydroxide. It is done. From the viewpoint of effectively increasing the flame retardancy, the flame retardant preferably contains a nitrogen-containing non-halogen flame retardant, red phosphorus, or phosphate ester. As for the said flame retardant, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of suppressing the expansion of the polyurethane foam, the nitrogen-containing non-halogen flame retardant is preferably a compound having a triazine skeleton. As for the said nitrogen-containing non-halogen flame retardant, only 1 type may be used and 2 or more types may be used together.

  Examples of the compound having a triazine skeleton include melamine compounds; cyanuric acid; cyanuric acid derivatives such as methyl cyanurate, diethyl cyanurate, trimethyl cyanurate, and triethyl cyanurate; isocyanuric acid; methyl isocyanurate, N, N′-diethyl isocyanate Nurate, trismethyl isocyanurate, trisethyl isocyanurate, bis (2-carboxyethyl) isocyanurate, 1,3,5-tris (2-carboxyethyl) isocyanurate, tris (2,3-epoxypropyl) isocyanurate, etc. Isocyanuric acid derivatives; melamine cyanurate; melamine isocyanurate and the like. Examples of the melamine compound include melamine and melamine derivatives. Examples of the melamine derivative include butyl melamine, trimethylol melamine, hexamethylol melamine, hexamethoxymethyl melamine, and melamine phosphate.

  From the viewpoint of suppressing the expansion of the polyurethane foam, the compound having a triazine skeleton is preferably a melamine compound, more preferably melamine, melamine cyanurate, melamine isocyanurate, or a derivative thereof. More preferred is cyanurate.

  As said phosphate ester, monophosphate ester, condensed phosphate ester, etc. are mentioned. From the viewpoint of effectively increasing the flame retardancy, the phosphate ester is preferably a monophosphate ester or a condensed phosphate ester. As for the said phosphate ester, only 1 type may be used and 2 or more types may be used together.

  Examples of the monophosphate include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri (2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, Tris (phenylphenyl) phosphate, trinaphthyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, diphenyl (2-ethylhexyl) phosphate, di (isopropylphenyl) phenyl phosphate, monoisodecyl phosphate, 2-acryloyloxyethyl acid phosphate , 2-methacryloyloxyethyl acid phosphate, diphenyl 2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, melamine phosphate, dimelamine phosphate, melamine pyrophosphate, triphenylphosphine oxide, tricresylphosphine oxide, diphenyl methanephosphonate, diethyl phenylphosphonate, relucinol Examples thereof include bis (diphenyl phosphate), phosphate ester bisphenol A bis (diphenyl phosphate), phosphaphenanthrene, and tris (β-chloropropyl) phosphate.

  Examples of the condensed phosphate ester include trialkyl polyphosphate, resorcinol polyphenyl phosphate, resorcinol poly (di-2,6-xylyl) phosphate, hydroquinone poly (2,6-xylyl) phosphate, bisphenol A polycresyl phosphate, and These condensates are mentioned.

  The phosphate ester is preferably a phosphate ester that is liquid at 23 ° C. Since the amount of the solid flame retardant can be relatively reduced by using the liquid phosphate ester, the viscosity of the curable composition can be appropriately reduced. Moreover, mixing of a compounding component becomes easy by using liquid phosphate ester.

  Examples of the phosphate-containing flame retardant include a phosphoric acid compound, a metal of group 1 element to group 4 element of the periodic table, ammonia, an aliphatic amine, an aromatic amine, or a heterocyclic ring containing a nitrogen atom. Examples include salts with compounds. Examples of the phosphoric acid compound include monophosphoric acid, pyrophosphoric acid, and polyphosphoric acid. Examples of metals of Group 1 elements to Group 4 elements of the periodic table include lithium, sodium, calcium, barium, iron (II), iron (III), and aluminum.

  In order to improve water resistance, the phosphate-containing flame retardant may be treated with a silane coupling agent or coated with a melamine resin. You may add well-known foaming adjuvants, such as a melamine and a pentaerythritol, to the said phosphate containing flame retardant.

  Examples of the bromine-containing flame retardant include brominated aromatic ring-containing aromatic compounds. Examples of the brominated aromatic ring-containing aromatic compounds include organic bromine compound monomers, polycarbonate oligomers, brominated polycarbonates, brominated epoxy compounds, brominated phenol condensates, brominated polystyrene, and halogenated bromine compound polymers. Can be mentioned.

  Examples of the boron-containing flame retardant include borax, boron oxide, boric acid, and borate.

  Examples of the antimony-containing flame retardant include antimony oxide, antimonate, and pyroantimonate.

  From the viewpoint of preventing generation of harmful gases during the combustion of the polyurethane foam, the flame retardant preferably does not contain a halogen compound, and when it contains a halogen compound, the content of the halogen compound is preferably small. In the flame retardant, the content of the halogen compound is preferably 1500 ppm or less. In the flame retardant, the chlorine content is preferably 900 ppm or less, the bromine content is preferably 900 ppm or less, and the fluorine content is preferably 900 ppm or less.

  The average diameter of the flame retardant is preferably 1 μm or more, more preferably 2 μm or more, preferably 50 μm or less, more preferably 20 μm or less. When the average diameter is equal to or greater than the lower limit, the flame retardant hardly aggregates. When the average diameter is not more than the above upper limit, clogging occurring in the nozzle of the spraying machine and in the pump is suppressed.

  The average diameter of the flame retardant is an average diameter measured on a number basis, and is a median diameter (D50) value of 50%. The average diameter can be measured by a laser diffraction / scattering method, an image analysis method, a Coulter method, a centrifugal sedimentation method, or the like. Measurement by laser diffraction / scattering method is preferred.

  A commercial item can be used as said red phosphorus.

  The content of the flame retardant is not particularly limited. The content of the flame retardant is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, and still more preferably 1 part by weight or more with respect to a total of 100 parts by weight of the polyol compound and the isocyanate compound. The amount is particularly preferably 5 parts by weight or more, preferably 60 parts by weight or less, more preferably 50 parts by weight or less, still more preferably 46 parts by weight or less, and particularly preferably 40 parts by weight or less. When the content of the flame retardant is equal to or more than the lower limit, expansion of the polyurethane foam is easily suppressed during the formation of the polyurethane foam. When the content of the flame retardant is not more than the above upper limit, the viscosity of the curable composition is appropriately lowered.

  When the flame retardant is the nitrogen-containing non-halogen flame retardant, the content of the nitrogen-containing non-halogen flame retardant is preferably 0.5% with respect to a total of 100 parts by weight of the polyol compound and the isocyanate compound. Part or more, more preferably 1 part by weight or more, preferably 20 parts by weight or less, more preferably 10 parts by weight or less. When the content of the nitrogen-containing non-halogen flame retardant is equal to or higher than the lower limit, expansion of the polyurethane foam is easily suppressed during formation of the polyurethane foam. When the content of the nitrogen-containing non-halogen flame retardant is not more than the above upper limit, the viscosity of the curable composition is appropriately lowered.

  When the flame retardant is red phosphorus, the content of the red phosphorus is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight with respect to a total of 100 parts by weight of the polyol compound and the isocyanate compound. Parts by weight or more, more preferably 1 part by weight or more, particularly preferably 5 parts by weight or more, preferably 60 parts by weight or less, more preferably 50 parts by weight or less, still more preferably 40 parts by weight or less, particularly preferably 20 parts by weight or less. It is. When the content of the red phosphorus is not less than the above lower limit, the self-extinguishing property of the curable composition is increased. When the content of the red phosphorus is not more than the above upper limit, foaming is hardly inhibited during the formation of the polyurethane foam, and the viscosity of the curable composition is appropriately reduced.

  As said flame retardant, you may use together red phosphorus and another flame retardant. As a flame retardant, when red phosphorus and another flame retardant are used in combination, the content of red phosphorus is preferably 10% by weight or more, more preferably 14% by weight or more, in a total of 100% by weight of the flame retardant. Preferably it is 50 weight% or less, More preferably, it is 20 weight% or less. When the content of the red phosphorus is not less than the above lower limit, it is easy to suppress the expansion of the polyurethane foam during the formation of the polyurethane foam. When the content of the red phosphorus is not more than the above upper limit, the viscosity of the curable composition is appropriately lowered.

  When the flame retardant is a phosphate ester, the content of the phosphate ester is preferably 20 parts by weight or more, preferably 40 parts by weight or less with respect to a total of 100 parts by weight of the polyol compound and the isocyanate compound. It is. When the content of the phosphoric acid ester is not less than the above lower limit, the viscosity of the curable composition is appropriately lowered. When the content of the phosphoric acid ester is not more than the above upper limit, foaming inhibition at the time of forming the polyurethane foam can be suppressed.

  As the flame retardant, a phosphate ester and another flame retardant may be used in combination. When a phosphoric acid ester and another flame retardant are used in combination as the flame retardant, the content of the phosphoric acid ester is preferably 30% by weight or more, more preferably 40% by weight or more in the total 100% by weight of the flame retardant. More preferably, it is 70% by weight or more, particularly preferably 71% by weight or more, preferably 80% by weight or less, more preferably 79% by weight or less. When the content of the phosphoric acid ester is not less than the above lower limit, the viscosity of the curable composition is appropriately lowered. When the content of the phosphoric acid ester is not more than the above upper limit, the expansion of the polyurethane foam is suppressed during the formation of the polyurethane foam.

  As the flame retardant, red phosphorus and phosphate ester may be used in combination. In a total of 100% by weight of the phosphate ester and the red phosphorus, the ratio of the phosphate ester content to the red phosphorus content (phosphate ester content / red phosphorus content) is based on weight. , Preferably 0.5 or more, more preferably 1 or more, still more preferably 2 or more, particularly preferably 3.1 or more, most preferably 3.5 or more, preferably 8 or less, more preferably 6 or less. When the ratio (phosphoric acid ester content / red phosphorus content) is equal to or higher than the lower limit, the viscosity of the curable composition is appropriately lowered. When the ratio (phosphoric acid ester content / red phosphorus content) is not more than the above upper limit, the expansion of the polyurethane foam is suppressed during the formation of the polyurethane foam.

[Foam stabilizer]
The curable composition preferably contains a foam stabilizer. As for the said foam stabilizer, only 1 type may be used and 2 or more types may be used together.

  Examples of the foam stabilizer include polyoxyalkylene foam stabilizer and silicone foam stabilizer. Examples of the polyoxyalkylene foam stabilizer include polyoxyalkylene alkyl ethers. Examples of the silicone foam stabilizer include organopolysiloxane. The foam stabilizer is preferably a surfactant.

  The content of the foam stabilizer can be used at an appropriate content so that bubbles are stably and satisfactorily formed. From the viewpoint of forming air bubbles stably and satisfactorily, the content of the foam stabilizer is preferably 0.01 parts by weight or more, preferably 10 parts by weight with respect to a total of 100 parts by weight of the polyol compound and the isocyanate compound. It is 5 parts by weight or less, more preferably 5 parts by weight or less.

(Other details of curable composition)
The said curable composition can be prepared by mixing the said polyol compound, the said isocyanate compound, the said foaming agent, the said filler, the said urethanization catalyst, and another component as needed. The mixing method of each component is not specifically limited. A plurality of liquids containing one or a plurality of components may be prepared, and a plurality of liquids may be mixed to obtain a curable composition. The mixing of the plurality of liquids may be performed at the time of forming the polyurethane foam. A curable composition may be obtained during the formation of the polyurethane foam. A curable composition may be obtained by preparing a first liquid containing the isocyanate compound and a second liquid containing the polyol compound and the foaming agent, and mixing these liquids. The filler, the urethanization catalyst, the flame retardant, and the foam stabilizer may be added to the first liquid, may be added to the second liquid, and the first liquid and You may add to both the said 2nd liquid.

  From the viewpoint of efficiently allowing urethane bonding to proceed at an appropriate time, the urethanization catalyst is preferably added to the second liquid. From the viewpoint of effectively increasing the flame retardancy, the flame retardant is preferably added to the second liquid.

(Polyurethane foam)
The polyurethane foam according to the present invention is a foam obtained by foaming the curable composition according to the present invention. The polyurethane foam according to the present invention can be formed by a known method using the curable composition according to the present invention.

  For example, a polyurethane foam can be formed by heating and curing and curing the curable composition at 60 to 70 ° C.

  From the viewpoint of keeping the thermal conductivity of the polyurethane foam low for a longer period of time, the polyurethane foam preferably has a high closed cell ratio. The closed cell ratio is a ratio of the independent bubbles in the cells (bubbles) of the polyurethane foam. The closed cell ratio can be measured by JIS K7138 (pressure change method).

  From the viewpoint of effectively increasing the thermal conductivity, the closed cell ratio of the polyurethane foam is preferably 75% or more, more preferably 80% or more.

(Example)
Hereinafter, the present invention will be specifically described by giving examples and comparative examples. The present invention is not limited to the following examples.

  The following materials were prepared.

(Polyol compound)
Terephthalic acid polyester polyol 1 ("Maximol RFK505" manufactured by Kawasaki Kasei Kogyo Co., Ltd.)
Terephthalic acid polyester polyol 2 ("Maximol RLK087" manufactured by Kawasaki Kasei Kogyo Co., Ltd.)
Terephthalic acid polyester polyol 3 ("Maximol RDK142" manufactured by Kawasaki Kasei Kogyo Co., Ltd.)
Succinic acid polyester polyol ("Maximol SDK145" manufactured by Kawasaki Kasei Kogyo Co., Ltd.)
Sucrose polyether polyol ("Sanix HS-209" manufactured by Sanyo Chemical Co., Ltd.)
Polyether polyol ("J610" manufactured by Sumika Covestro Urethane Co., Ltd.)

(Isocyanate compound)
Diphenylmethane diisocyanate (“Millionate MR-200” manufactured by Tosoh Corporation)

(Foaming agent)
1,1,1,4,4,4-hexafluoro-2-butene (“HFO1336mzz” manufactured by DuPont): unsaturated organic halogen compound trans-1-chloro-3,3,3-trifluoropropene (Honeywell) “Solstice LBA”: Unsaturated organic halogen compound Isopropyl chloride: Saturated organic halogen compound Water

(Filler)
Graphite 1 (“J-CPB” manufactured by Nippon Graphite Industries Co., Ltd., average diameter 5 μm, average aspect ratio 8.3)
Graphite 2 (“CPB” manufactured by Nippon Graphite Industries Co., Ltd., average diameter 19 μm, average aspect ratio 20)
Graphite 3 (“FB-150” manufactured by Nippon Graphite Industries Co., Ltd., average diameter 45 μm, average aspect ratio 45)
Mica 1 (manufactured by Repco “M-XF”, average diameter 4 μm, average aspect ratio 15)
Mica 2 (“M-325” manufactured by Repco, average diameter 26 μm, average aspect ratio 20)

  The average diameter of the filler was measured by a laser diffraction / scattering method.

  The average thickness for obtaining the average aspect ratio of the filler was measured by a water surface particle film method.

(catalyst)
N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine (“TOYOCAT-DT” manufactured by Tosoh Corporation)
Tertiary amine mixture (“TOYOCAT-CX40” manufactured by Tosoh Corporation)
Quaternary ammonium salt / ethylene glycol mixture (“TOYOCAT-TRX” manufactured by Tosoh Corporation)
Imidazole special composite catalyst ("Kao Riser # 300" manufactured by Kao)

(Flame retardants)
Red phosphorus ("Nova Excel" manufactured by Rin Chemical Industry Co., Ltd.)
Phosphate ester bisphenol A bis (diphenyl phosphate) ("CR-741" manufactured by Daihachi Chemical Co., Ltd.)
Melamine cyanurate (Nissan Chemical Industries "MC-4500")

(Foam stabilizer)
Silicone foam stabilizer ("SH193" manufactured by Toray Dow Corning)

(Examples 1 and 2, Comparative Examples 1 and 2)
(Preparation of curable composition)
Each material other than the isocyanate compound and the filler was mixed to obtain a polyol premix. The obtained polyol premix was mixed with a filler. A curable composition was prepared by blending and mixing an isocyanate compound with the obtained mixture. Each component was used in the amount (parts by weight) shown in Table 1 below.

(Production of polyurethane foam)
The obtained curable composition was poured into a mold (size of 300 × 300 × 50 mm) and then heated in an oven at 60 ° C. for 10 minutes to foam and harden, thereby producing a polyurethane foam.

(Example 3-13, Comparative Example 3-5)
A curable composition and a polyurethane foam were obtained in the same manner as in Example 1 except that the types and amounts (parts by weight) of the components used were changed as shown in Tables 2 and 3 below.

(Evaluation)
(1) Closed cell ratio The closed cell ratio of the obtained polyurethane foam was measured according to JIS K7138 (pressure change method).

[Criteria for closed cell ratio]
○: Closed cell ratio is 80% or more △: Closed cell ratio is 75% or more and less than 80% ×: Closed cell ratio is less than 75% (foam failure)

(2) Thermal conductivity deterioration rate The thermal conductivity of the obtained polyurethane foam was measured according to JIS A 9521: 2014, and was defined as the initial thermal conductivity.

  In Examples 1, 2, 8-13 and Comparative Examples 1, 2, and 5, the obtained polyurethane foam was stored in an oven at 70 ° C. for 5 weeks. The thermal conductivity of the polyurethane foam after storage was measured according to JIS A 9521: 2014, and was defined as the long-term thermal conductivity. Since the deterioration of the polyurethane foam is promoted by storage at 70 ° C. and 5 weeks, the long-term thermal conductivity corresponds to, for example, the thermal conductivity after the polyurethane foam is stored at room temperature for about 5 years.

  In Example 3-7 and Comparative Examples 3 and 4, long-term thermal conductivity was measured in the same manner as in Example 1 except that the obtained polyurethane foam was stored in an oven at 70 ° C. for 10 weeks. Since the deterioration of the polyurethane foam is promoted by storage at 70 ° C. and 10 weeks, the long-term thermal conductivity corresponds to, for example, the thermal conductivity after the polyurethane foam is stored at room temperature for about 10 years.

  From the obtained initial thermal conductivity and long-term thermal conductivity, the thermal conductivity deterioration rate was determined by the following formula. When the thermal conductivity deterioration rate is less than 100%, it can be said that the thermal conductivity value of the polyurethane foam is maintained for a long period of time and is excellent in long-term heat insulation. Using Comparative Example 1 as STD, the thermal conductivity deterioration rates of Examples 1 and 2 and Comparative Example 2 were determined. The thermal conductivity deterioration rate of Example 3-7 and Comparative Example 4 was calculated using Comparative Example 3 as STD. Using Comparative Example 5 as STD, the thermal conductivity deterioration rate of Examples 8-13 was determined.

  Thermal conductivity change rate (%) = initial thermal conductivity / long-term thermal conductivity × 100

  Thermal conductivity deterioration rate (%) = STD thermal conductivity change rate−thermal conductivity change rate

[Criteria for thermal conductivity deterioration rate]
○: Thermal conductivity deterioration rate is −3% or less ○: Thermal conductivity deterioration rate is over −3% and −2% or less Δ: Thermal conductivity deterioration rate is over −2% and 0% or less ×: Heat Conductivity deterioration rate exceeds 0%

(3) Cell average diameter In Comparative Example 5 and Examples 8-13, the obtained polyurethane foam was thinly sliced in the thickness direction using a razor to obtain slice pieces. The slice piece was photographed at a scale size of 100 times using a digital microscope (“VHX-100” manufactured by Keyence Corporation). With respect to the cells displayed in the obtained micrographs, using the image analysis software, as shown in FIG. 1, a circle inscribed in the cell and having the maximum diameter was drawn, and the diameter of the circle was calculated. Similarly, the diameter of the circle was calculated for a total of 100 cells, and the average value of the diameters of the 100 circles was taken as the average cell diameter of the obtained polyurethane foam.

  The compositions and results are shown in Tables 1 to 3 below.

Claims (8)

Including a polyol compound, an isocyanate compound, a foaming agent, and a filler;
The blowing agent comprises an unsaturated organohalogen compound;
The filler has an average diameter of 30 μm or less,
The curable composition whose average aspect-ratio of the said filler is 5 or more.   The curable composition of Claim 1 whose content of the said filler is 1 to 13 weight part with respect to a total of 100 weight part of the said polyol compound and the said isocyanate compound.   The curable composition of Claim 1 or 2 whose average aspect-ratio of the said filler is less than 40.   The curable composition according to any one of claims 1 to 3, wherein the filler is an inorganic mineral.   The curable composition according to any one of claims 1 to 4, wherein the filler is graphite or mica.   The curable composition according to any one of claims 1 to 5, wherein the foaming agent further contains water or a saturated organic halogen compound.   The curable composition according to any one of claims 1 to 6, wherein the unsaturated organic halogen compound is hydrochlorofluoroolefin or hydrofluoroolefin.   The polyurethane foam in which the curable composition of any one of Claims 1-7 was foamed.