JP4699834B2 - Method for producing polyisocyanurate foam - Google Patents

Description

  The present invention relates to a method for producing a polyisocyanurate foam excellent in heat insulation and dimensional stability.

  Among various urethane foams, polyisocyanurate foams are excellent in heat insulation and flame retardancy, and have high strength, and thus are suitably used for various heat insulating materials and building material panels. And since the foam excellent in a flame retardance and heat insulation is obtained, conventionally, chlorofluorocarbons (fluorocarbons), such as trichlorofluoromethane, have been used as a foaming agent.

  However, since chlorofluorocarbon is an environmentally destructive substance such as ozone layer depletion and global warming in the stratosphere, its use is demanded to be limited. Various urethane foams such as isocyanurate foams using next-generation fluorocarbons such as HFC-245fa as foaming agents have been studied. In recent years, hydrocarbon-based blowing agents such as cyclopentane, isopentane, and normal pentane, which do not contain chlorine atoms, have been studied as environmentally friendly blowing agents that hardly cause ozone layer destruction.

  On the other hand, in recent years, it has been known that an inorganic layered material such as a layered silicate that is an inorganic material is dispersed in a resin such as polyamide on the nano order to improve the heat resistance or gas barrier property of the resin. Various urethane foams used are also known.

  However, when an inorganic layered material is used as the raw material for urethane foam, if the inorganic layered material is insufficiently dispersed in the urethane foam, the foam cells (bubbles) become coarse, and the closed cell ratio decreases, thereby insulating the foam. In addition to inferior properties, the resulting urethane foam is subject to dimensional changes, a decrease in compressive strength over time, etc., so it is necessary to disperse it to the nano-order in the urethane foam, but the inorganic layered material aggregates. It is easy and settles, and it took relatively time and effort to disperse it in the nano-order in the urethane foam.

  Therefore, various studies have been made to disperse these inorganic layered materials in the nano-order in the urethane foam. For example, in Patent Document 1 below, an isocyanate composition, a polyol, a foam stabilizer, and a catalyst are used. And a foaming agent comprising at least one of hydrocarbons having 4 to 6 carbon atoms, water, and a carboxylic acid compound as a foaming agent component, and 0.1 to 1. It is disclosed to mix and foam cure with 5 wt% layered silicate.

Patent Document 2 below discloses foaming and curing a urethane mixture containing a polyol mixture in which a layered silicate treated with a quaternary alkyl ammonium salt is dispersed in a polyol, an isocyanate composition, and water. Has been.
JP 2003-48941 A JP 2004-339437 A

  As disclosed in Patent Documents 1 and 2 above, the layer silicate is treated with an organic affinity treatment with a quaternary ammonium salt or the like, so that the layers of the layer silicate are easily opened and the dispersibility is improved. It was sufficient and the foam obtained had poor water absorption, compressive strength, and dimensional stability.

  In order to supplement the dispersibility, it is conceivable to increase the addition of the inorganic layered material. However, the polyisocyanurate foam tends to be inferior in adhesiveness to the face material compared to the urethane foam. A foam obtained by adding an inorganic layered material to a nurate foam is further inferior in face material adhesion, and is difficult to use as a foam board.

  Therefore, the object of the present invention is excellent in mechanical strength, dimensional stability, water absorption, heat insulation, flame retardancy, and productivity, and also excellent in adhesion to a face material, and is suitably used as a foam board. It is in providing the manufacturing method of the polyisocyanurate foam which can be used.

In achieving the above object, the method for producing the polyisocyanurate foam of the present invention comprises:
A method for producing a polyisocyanurate foam by foam-curing a foam raw material containing a polyol mixture containing at least a polyol, an inorganic layered material, and a foaming agent, an isocyanate composition, and a catalyst. The organic layered silicate having a water content of 20 to 90% by mass obtained by treating the layered silicate with a quaternary ammonium salt as the inorganic layered material using pentane, and containing the trimerization catalyst as the catalyst, As said polyol mixture, 5-100 mass parts of said inorganic layered materials are contained with respect to 100 mass parts of said foaming agents, and layered silicate is 0.1-1.0 masses with respect to 100 mass parts of said foam raw materials. What mix | blended the said inorganic layered material so that it may contain part is used, It is characterized by the above-mentioned.

  By using the organic layered silicate having the above-mentioned water content as the inorganic layered material, it does not impair the physical properties such as heat insulation, dimensional stability, flame retardancy, etc. of the obtained foam. Since the dispersibility in the polyol mixture can be improved without lowering the water absorption of the polyisocyanurate foam, a polyisocyanurate foam excellent in mechanical strength in which the layered silicate is dispersed in the nano order. It can be produced efficiently. In addition, since the layers of the layered silicate are easily peeled and the silicate layer is efficiently dispersed in the foam, a high reinforcing effect by the silicate can be obtained even with a small amount of addition, which has been regarded as a problem in the past. In addition, it is possible to improve poor adhesion with a face material that tends to occur by blending an inorganic layered material. Furthermore, the layered silicate treated with the quaternary ammonium salt does not have the same polarity as the polyether polyol, and precipitation may occur. Since precipitation does not occur even when used, it can be applied to a wide range of polyols.

  In the method for producing a polyisocyanurate foam of the present invention, as the polyol mixture, an inorganic layered material is dispersed in advance in the polyol to obtain a dispersion solution, and then the dispersion solution is dispersed in the foaming agent. It is preferable. According to this, the dispersion efficiency of the inorganic layered material is improved, and as a result, it is possible to efficiently obtain a foam in which the inorganic layered material is dispersed in the nano order, which is often seen in closed-cell type urethane resin foams. Moreover, the shrinkage immediately after foaming curing and the deterioration of heat insulation over time can be improved.

  Moreover, it is preferable to use what the said foaming agent contains 3-7 mass parts with respect to 100 mass parts of said foam raw materials as said polyol mixture, Furthermore, pentane / water by the molar ratio of pentane and water. However, it is preferable to use what is 50 / 50-90 / 10. According to this, it can be set as the polyisocyanurate foam excellent in dimensional stability, heat insulation, a moldability, a flame retardance, etc.

  Further, as the inorganic layered material, it is preferable to use a layered silicate / quaternary ammonium salt in a mass ratio of the layered silicate to the quaternary ammonium salt of 75/25 to 35/65. The organically modified layered silicate is preferably further treated with a silane coupling agent. According to this, it is easy to delaminate the layered silicate, the layered silicate can be nano-dispersed in the polyol mixture in a short time, and thixotropic expression is suppressed when the layered silicate is dispersed in the polyol mixture. Therefore, the miscibility with the isocyanate composition is not impaired.

  The quaternary ammonium salt used for the organic treatment of the layered silicate is preferably a tetraalkylammonium salt. According to this, the layered silicate treated with the tetraalkylammonium salt is easily peeled off and easily nano-dispersed in the polyol mixture.

  Moreover, it is preferable to use what contains the compound which further has a morpholine ring in a molecule | numerator as said foam raw material. According to this, since the polyisocyanurate foam excellent in adhesiveness with a face material can be obtained, it can be used suitably as a foam board etc.

According to the method for producing a polyisocyanurate foam of the present invention, a polyisocyanurate foam excellent in mechanical strength, heat insulation, dimensional stability, water resistance, flame retardancy and the like can be efficiently obtained. Further, thus obtained polyisocyanurate foams, adhesive has been improved with conventional inorganic layered materials polyisocyanurate foam seen face material using, it can be suitably used for foam board, etc. .

  The polyisocyanurate foam in the present invention is obtained by foam-curing a foam material containing a polyol mixture, an isocyanate composition, and a catalyst. Hereinafter, each component used for the manufacturing method of the polyisocyanurate foam of this invention is demonstrated in detail.

  The isocyanate composition used in the method for producing a polyisocyanurate foam of the present invention is not particularly limited as long as it can be used for a general urethane resin foam. Specifically, for example, phenylene diisocyanate, Examples include tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, and the like. Of these, polymethylene polyphenyl polyisocyanate (crude MDI) is preferred. In addition, the isocyanate composition may be used alone or as a mixed system of two or more, and further, an aliphatic polyisocyanate or alicyclic polyisocyanate and an aromatic polyisocyanate composition, You may mix and use the isocyanate group terminal prepolymer obtained by making it react with a polyol, the isocyanurate compound which has an isocyanate group obtained by trimerizing an isocyanate composition, etc.

  The polyol mixture of the polyisocyanurate foam used in the method for producing the polyisocyanurate foam of the present invention is a mixture containing at least a polyol, an inorganic layered material, and a foaming agent.

  As the polyol used in the polyol mixture, polyether polyol, polyester polyol, and the like can be used. Among them, it is preferable to use polyester polyol because the dispersibility of the inorganic layered material described later is improved. And as polyester polyol, it is preferable to use the aromatic polyester polyol which has two or more hydroxyl groups in the terminal or the side chain obtained by condensing bifunctional or more polyfunctional polyol and polybasic acid.

  As polyfunctional polyols, 1); ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, neopentylglycol, hexanediol, cyclohexanedimethanol, bisphenol A, bisphenol F, bisphenol S or the like, or a compound obtained by addition polymerization of ethylene oxide or propylene oxide alkylene oxide, bifunctional polyol such as polyethylene glycol or polypropylene glycol, 2); trimethylolpropane, glycerin or the like, or alkylene oxides thereof Trifunctional polyols such as compounds obtained by addition polymerization of 3); pentaerythritol, dipentaerythritol, sorbitol, S etc., or multifunctional polyol such as these compounds by addition polymerization of alkylene oxides and the like.

  Examples of the polybasic acid include orthophthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, trimellitic acid, pyromellitic acid and the like.

  From the viewpoint of flame retardancy, polyester polyols obtained by condensing phthalic acid with difunctional, trifunctional, or polyfunctional alcohols or one or more of these alkylene oxide adducts are preferred, and terephthalic acid and diethylene glycol are preferred. Polyester polyols obtained by condensing and are particularly preferred.

  The hydroxyl group content of the polyol is preferably 2 to 3. If the hydroxyl group content is 2 or more, the resulting polyisocyanurate foam has good dimensional stability, and if it is more than 4, the adhesion to the face may be impaired. The following is preferable.

  The hydroxyl value of the polyol is preferably 100 to 1,000 [KOH mg / g], more preferably 150 to 400 [KOH mg / g]. If the hydroxyl value is within the above range, the resulting polyisocyanurate foam will not be too stiff and will not be soft, so that it will have good adhesion to the face material and will be suitable as a foam board. A nurate foam is obtained.

  As a viscosity of a polyol, it is preferable that it is 10,000 cps or less, More preferably, it is 300-1,500 cps. If the viscosity is 10,000 cps or less, the miscibility with the isocyanate composition is not impaired, so that the polyisocyanurate foam can be produced with high productivity.

  As the inorganic layered material used for the polyol mixture, an organically layered silicate having a water content of 20 to 90% by mass obtained by treating the layered silicate with a quaternary ammonium salt is used.

  Here, the layered silicate has a structure in which a silicate layer having a thickness of about 1 nm and a length of about 100 to 500 nm is laminated, and further, sodium ions, potassium ions, calcium ions, etc. are present between the silicate layers. It is a material having a property that a swelling agent such as water swells by expanding the interlayer distance from a densely laminated state by electrostatically (hydrating) the cation. Specific examples of the layered silicate include smectites such as montmorillonite, beidellite, nontrolite, hectorite, saponite, vermiculite, halosite, mica, and the like.

  In the present invention, an organically modified layered silicate having an organic affinity in which exchangeable cations such as sodium, potassium or calcium ions existing between layers of the layered silicate are ion-exchanged with a quaternary ammonium cation is used.

  The oxygen atom on the surface of the silicate layer easily forms a hydrogen bond with a functional group having an active hydrogen such as a hydroxyl group, an amino group, or a carboxyl group. Therefore, an organic compound having the above functional group is inserted between the layered silicate layers (intercalation). ), The layered silicate easily swells (delaminates). Therefore, the organically modified layered silicate that has been subjected to the above treatment easily spreads the gap between the layers, and is easily nanodispersed in the polyol.

  The quaternary ammonium salt used for the organic treatment of the layered silicate is preferably a tetraalkylammonium salt, and at least one of the four alkyl groups contained is a methyl group, an ethyl group, a dodecyl group, or a tetradecyl group. A quaternary alkyl ammonium salt containing a hexadecyl group or an octadecyl group is particularly preferred. Specifically, dodecyl trimethyl ammonium salt, tetradecyl trimethyl ammonium salt, hexadecyl trimethyl ammonium salt, octadecyl trimethyl ammonium salt, dioctadecyl dimethyl ammonium salt, dihexadecyl dimethyl ammonium salt, trimethyl stearyl ammonium salt, dimethyl stearyl ammonium salt, etc. And trimethylstearylammonium salt and dimethylstearylammonium salt are particularly preferable.

  As the amount of quaternary ammonium salt inserted or attached to the layered silicate, the layered silicate / quaternary ammonium salt is preferably 75/25 to 35/65 by mass ratio of the layered silicate to the quaternary ammonium salt, More preferably, it is 65 / 35-45 / 55.

  If the amount of quaternary ammonium salt inserted or adhered is less than 25 in the above mass ratio, the organic affinity is poor, and it takes time to disperse the layered silicate to the nano-order in the polyol mixture, and the productivity In some cases, the layered silicate is not dispersed to the nano order, and the improvement aimed at by the present invention is not manifested. On the other hand, when the amount of quaternary ammonium salt inserted or adhered exceeds 65 in the above mass ratio, the metal cation on the surface of the silicate layer is sufficiently ion-exchanged with the quaternary ammonium cation. It may remain, which is uneconomical and inferior in heat resistance and heat insulation.

  Further, the water content of the organically modified layered silicate is required to be 20 to 90% by mass, and preferably 40 to 80% by mass. The moisture content can be obtained, for example, by heating the organically modified layered silicate at 105 ° C. until there is no change in mass, and determining the ratio of the mass reduced by heating to the mass before heating.

  By treating the layered silicate with a quaternary ammonium salt, the interlayer of each silicate layer can be easily opened. However, when the water content is low, the interlayer opening is narrowed. However, it is easy to cause delamination (swelling) and nano-dispersion with the organic layered silicate having the above water content. This is because the presence of water molecules in addition to the quaternary ammonium salt widens the interlayer, so the polyol molecules and pentane molecules easily enter the interlayer and cause delamination. It is considered that the water molecules between the layers react with the isocyanate to expand the layers, so that nano-dispersion is facilitated.

  And when the water content of the organically modified layered silicate is less than 20% by mass, the dispersibility of the layered silicate tends to be inferior, and it takes time and labor to disperse the layered silicate in the nano order. When a polyether polyol is used as a polyol, precipitation may occur due to a difference in polarity, and it cannot be applied to a wide range of polyols. In addition, if the water content exceeds 90% by mass, the layered silicate cannot be blended so much as a result, so that the reinforcing effect by the layered silicate can hardly be obtained, and the moisture content may become excessive, and the predetermined density It becomes difficult to obtain a foam.

  Accordingly, organic layered silicates having a water content in the above range (hereinafter referred to as “water-containing organic layered silicate”) can be applied to a wide range of polyols, and the dispersibility of the layered silicate can be improved. It can be set as the polyisocyanurate foam excellent in physical properties, such as intensity | strength, heat insulation, dimensional stability, a flame retardance, and water resistance. In addition, since the dispersibility of the layered silicate is high, a high reinforcing effect (improvement in mechanical strength, heat resistance, water resistance, etc.) due to the layered silicate can be obtained even with a small addition amount. As a result, the layered silicate The blending amount can be reduced, and poor adhesion with a face material that tends to occur by blending an inorganic layered material such as a layered silicate can be improved.

  Such a water-containing organic layered silicate is prepared by, for example, dispersing a layered silicate in an aqueous quaternary ammonium salt solution having an appropriate concentration and stirring it in a swollen state, and ion-exchange Na ions between the layers with quaternary ammonium ions. After the treatment, it can be obtained by performing a treatment such as filter pressing so as to obtain a predetermined water content.

  In the present invention, it is preferable to use, as the inorganic layered material, the above hydrous organically modified layered silicate which has been further treated with a silane coupling agent. By further treating the hydrated organic layered silicate with a silane coupling agent, the fluidity of the mixture of the polyol mixture and the isocyanate composition can be reduced by increasing the viscosity of the polyol mixture, changing the viscosity, and developing thixotropic properties. Can be suppressed.

  Such a silane coupling agent is not particularly limited. For example, 1); N-β (2-aminoethyl) γ-aminopropyltrimethoxysilane, N-β (2-aminoethyl) γ-aminopropyl Aminosilanes such as methyldimethoxysilane, γ-aminepropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, 2); vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyl Vinylsilanes such as trimethoxysilane, 3); Acrylic silanes such as γ-methacryloxypropyltrimethoxysilane, 4); β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-glycidoxypropylmethyldi Examples thereof include epoxy silanes such as ethoxysilane, 5); γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Of these, aminosilanes are more preferably used in the present invention.

  And as an adhesion amount of a silane coupling agent, it is preferable that it is 0.05-2 mass% with respect to the said layered silicate, More preferably, it is 0.1-1 mass%. When the adhesion amount of the silane coupling agent is less than 0.05% by mass, the effect of suppressing the aggregation of the layered silicate is small, the dispersibility cannot be improved so much, and the adhesion amount is 2% by mass. Even if it exceeds, since the effect which suppresses aggregation of a layered silicate does not improve so much, it is economically unpreferable.

  And content of the inorganic layered material in a polyol mixture needs to mix | blend in a polyol mixture so that layered silicate may be 0.1-1.0 mass part with respect to 100 mass parts of said foam raw materials. Preferably, it is 0.2-1.0 mass part. If the amount is less than 0.1 parts by mass, the reinforcing effect of the layered silicate is poor, and if it exceeds 1.0 parts by mass, the adhesiveness of the resulting foam to the face material may be inferior.

  As the foaming agent used in the polyol mixture, it is more preferable to use cyclopentane, normal pentane, or isopentane because pentane is used to obtain a polyisocyanurate foam excellent in heat insulation and dimensional stability.

  Moreover, it is preferable to mix | blend a foaming agent in a polyol mixture so that pentane / water may be 50 / 50-90 / 10 by the molar ratio of pentane and water, More preferably, it is 70 / 30-85 / 15. When the ratio of pentane is less than 50, it becomes easy to form a rigid foam, which tends to have poor adhesion to a face material, etc., and is also poor in heat insulation, and further, the foam tends to shrink over time. Therefore, the dimensional stability is likely to be inferior. On the other hand, if the ratio of pentane exceeds 90, it becomes difficult to obtain sufficient heat in the urethane reaction between the polyol mixture and the isocyanate composition, so that nurateization tends to be insufficient, and the strength of the resulting foam is low. It tends to decrease, and the flame retardancy tends to be poor.

  Here, since the water contained in the polyol mixture can be supplemented with the water contained in the inorganic layered material, the addition of water is not particularly necessary, but the molar ratio of pentane to water is adjusted within the above range. If necessary, water may be further added as necessary.

  And it is preferable to mix | blend in a polyol mixture so that content of a foaming agent may be 3-7 mass parts with respect to 100 mass parts of said foam raw materials, More preferably, it is 4-6 mass parts. If the content of the foaming agent is within the above range, an isocyanurate foam that is lightweight, excellent in handleability and workability, and excellent in heat insulation can be obtained.

  In the present invention, the catalyst may be added when mixing the polyol mixture and the isocyanate composition, or may be contained in the polyol mixture in advance.

  As the catalyst, a trimerization catalyst is used, and in order to adjust the reaction rate and moldability, a foaming catalyst and a resinification catalyst may be used in combination as necessary.

  Examples of the trimerization catalyst include 1); metal oxides such as lithium oxide, sodium oxide, and potassium oxide, 2); methoxy sodium, ethoxy sodium, propoxy sodium, butoxy sodium, methoxy potassium, ethoxy potassium, propoxy potassium, Alkoxides such as butoxy potassium, 3); organometallic salts such as potassium acetate, potassium octylate, iron oxalate, etc. 4); 2,4,6-tris (dimethylaminomethyl) phenol, N, N ′, N ″ -Tertiary amines such as tris (dimethylaminopropyl) hexahydrotriazine and triethylenediamine, 5); derivatives of ethyleneimine, 6); acetylacetone chelates of alkali metals, aluminum and transition metals, quaternary ammonium salts, etc. These are independent Or a mixture of two or more kinds can be used, inter alia, it is more preferable to use an organic metal salts and quaternary ammonium salts.

  As the foaming catalyst, a catalyst having a high effect of promoting the reaction between water and an isocyanate group is preferably used. Specifically, N, N, N ′, N ′, N ″ -pentamethyldiethylenetriamine, Bis (2-dimethylaminoethyl) ether, N, N, N′-trimethylaminoethylethanolamine, N, N ′, N ″ -tris (3-dimethylaminopropyl) hexahydro-s-triazine, N, N-dimethyl Cyclohexylamine is preferred.

  Further, compounds having a morpholine ring in the molecule such as N-methylmorpholine, N-ethylmorpholine, 4,4′-oxydimethylenedimorpholine, N, N-dimethylaminoethylmorpholine (hereinafter referred to as “morpholine compounds”). Can be preferably employed because it can improve the surface properties of the resulting foam and improve the adhesion to the face material. The morpholine compound has a boiling point of 200 ° C. or less. Some are preferred. And as content of a morpholine type compound, it is preferable that it is 0.04-0.4 mass% with respect to the whole quantity of a foam raw material, and it is more preferable that it is 0.1-0.3 mass%.

  In the present invention, various additives such as a foam stabilizer, a flame retardant, a viscosity reducer, a face material adhesion improver, and a cell finer can be used. These additives include a polyol mixture and an isocyanate. It may be added when mixing with the composition, or may be contained in the polyol mixture in advance.

  The foam stabilizer is not particularly limited, and conventionally known nonionic surfactants, silicone surfactants, and the like can be used. From the viewpoint of heat insulation, it is preferable that the bubble diameter of the foam is small. Therefore, a foam stabilizer having a high cell nucleus forming ability in which the bubble diameter tends to be relatively small is preferable. Examples of such foam stabilizers include “TEGOSTAB-B8461”, “TEGOSTAB-B8474”, and “TEGOSTAB-B8870” commercially available from GOLDSHMIT, and “SF2938F” commercially available from Toray Dow Corning. “SF2939” or the like can be preferably used.

  Flame retardants include phosphorus compounds such as ammonium polyphosphate, melamine phosphate and triphenylphosphine, melamine compounds such as melamine cyanurate and melamine, metal hydrates such as aluminum hydroxide and magnesium hydroxide, trimethyl phosphate, Triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenol phosphate, cresyl di 2,6-xylenyl phosphate, tris (dichloropropyl) phosphate, tris (chloropropyl) phosphate, tris (tri And phosphoric acid ester compounds such as bromoneopentyl) phosphate. Among them, phosphoric acid ester compounds are preferable, and tris (chloropropyl) phosphate is particularly preferable. Li ethyl phosphate, a tricresyl phosphate.

  As the thickener, conventionally known ones can be used, and examples include glycol ethers, compounds obtained by addition polymerization of alkylene oxides thereto, low molecular alcohols, low viscosity phosphate esters, and the like. Also, as the face material adhesion improver, conventionally known ones can be used, such as glycol ethers, compounds obtained by addition polymerization of alkylene oxides thereto, low molecular alcohols, low viscosity phosphate esters, and the like. Can be mentioned. As the bubble refining agent, conventionally known ones can be used, and examples thereof include polyalkylpolysiloxanes and perfluoro compounds having a low degree of condensation.

  In the present invention, the polyol, inorganic layered material, and a foaming agent added and mixed are used as a polyol mixture. After the inorganic layered material is dispersed in the polyol in advance to form a dispersion solution, the dispersion solution is used as the foaming agent. It is preferable to use those dispersed in an agent. By dispersing the inorganic layered material in the polyol in this way, the dispersion efficiency of the inorganic layered material is improved, the occurrence of precipitation and the like can be suppressed, and a foam in which the inorganic layered material is dispersed on the nano order is produced with high productivity can do. As described above, the catalyst, foam stabilizer, water, flame retardant, viscosity reducer, face material adhesion improver, bubble refining agent, and the like can be added to the polyol mixture in advance.

  And in the manufacturing method of the polyisocyanurate foam of this invention, when not adding a catalyst in the said isocyanate composition, the said polyol mixture, and a polyol mixture, a catalyst is used, for example, a general purpose high-pressure foaming machine etc. The mixture is collided into a mixed solution, and the mixed solution is put into a mold having a predetermined size and foamed and cured. As a mixing ratio of the isocyanate composition and the polyol mixture, it is preferable to mix so that the isocyanate index is 150 to 450.

  If the isocyanate index is less than 150, the formation of nurate rings tends to be reduced, and the resulting polyisocyanurate foam is insufficient in strength and tends to be inferior in flame retardancy. Is too stiff to have poor adhesion to the face material, insufficient curing, and voids and wrinkles are likely to occur, resulting in poor moldability and tend to be difficult to use as foam boards.

  As temperature of shaping containers, such as a metal mold | die, it is preferable that it is 40-85 degreeC, More preferably, it is 55-70 degreeC. The foam curing temperature is poor at less than 40 ° C., and when it exceeds 85 ° C., the surface of the foam becomes rough and the appearance is inferior, and the adhesiveness to the face material is inferior.

The polyisocyanurate foam thus obtained has a density of 27 to 40 kg / m ³ , a thermal conductivity of 19 to 22 mW / mK, a closed cell ratio of 90% or more, and a compressive strength of 1.5 kg / cm ^2. It is above and has high heat insulation. Further, since the foam does not shrink over time, the dimensional stability is excellent, and furthermore, since the generation of voids and wrinkles is extremely small, the moldability is also good. Moreover, since adhesiveness with a face material etc. is also favorable, a face material can be affixed on the outer periphery and it can be used suitably as a foam board.

  The face material has a resin layer such as polyethylene resin, acrylic resin, and epoxy resin on the surface in contact with the polyisocyanurate foam from the viewpoint of heat insulation and adhesiveness, and at least one aluminum layer. It is preferable to have a fiber layer such as kraft paper, nonwoven fabric, or woven fabric between the resin layer and the aluminum layer.

  Moreover, it is preferable that the thickness of an aluminum layer is 3-40 micrometers in total, More preferably, it is 9-40 micrometers. If it is 3 micrometers or more, heat insulation can be improved. Even if the thickness of the aluminum layer is larger than 40 μm, the cost and weight are only increased and the effect is not improved so much. Therefore, the thickness is preferably 40 μm or less.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Production of Polyisocyanurate Foam]
Each raw material was mixed in the ratio shown in Table 1, and stirred at a rotational speed of 5000 rpm for 5 seconds using a lab mixer. After that, this mixed solution (foam material) is placed in a side part-open aluminum mold having inner dimensions of 500 mm × 500 mm × 48 mm, in which face materials with polyethylene resin coatings formed on the upper and lower surfaces are heated to 65 ° C. And after 6 minutes, the mold was removed to obtain polyisocyanurate foams of Examples 1 to 7 and Comparative Examples 1 to 6. In addition, as an inorganic layered material, what was shown in Table 2 was used.

[Evaluation item]
(Thermal conductivity)
The method was performed in accordance with JIS A 1412, and the thermal conductivity of the foam was measured at an average temperature of 20 ° C.

(viscosity)
The viscosity at 25 ° C. of the polyol mixture was measured. If less than 1500 cps, ◎, 1500 to 3000 cps, ○, 3000 to 5000 cps, Δ, and 5000 cps, x.

(Water absorption)
What adjusted polyisocyanurate to 100 mm x 100 mm x 25 mm was used as a test piece, and this test piece was immersed in water. After 24 hours, the test piece was taken out from the water and sufficiently removed from water, and the weight change before and after immersion in water was measured. 1.5 to 2.0 g, Δ, and 2.0 g were evaluated as x.

(Dimensional stability)
The measurement was carried out by a method in accordance with JIS A 9511, and the dimensional change rate in the thickness direction of the foam under wet heat conditions (temperature: 60 ° C., humidity: 95%) was measured. When the rate of dimensional change was less than 1%, ◎, when it was 1-2%, ◯, when it was 2-3%, Δ, when it exceeded 3%, x.

(Compressive strength)
Performed by a method in accordance with JIS A 9511, a strength at break of the foam were measured, if it exceeds 1.8 kg / cm ² ◎, if 1.5~1.8kg / cm ² ○, 1.2 If it was ˜1.5 kg / cm ² , Δ, and if it was less than 1.2 kg / cm ² , it was rated as x.

(Surface adhesive)
A 100 mm × 100 mm square cut was made in the face material of the obtained test body, one side of the face material was peeled from the foam by 5 mm, and a clip was attached to the peeled portion. Thereafter, the clip was pulled in the vertical direction of the face material, the face material was peeled from the foam, and the maximum load at that time was measured. ◎ if the maximum load exceeds 2.0 kg, ○ if 1.5-2.0 kg, Δ if 1.2-1.5 kg, x if less than 1.2 kg.

The said test was done about the polyisocyanurate foam of Examples 1-7 and Comparative Examples 1-6, and a result is put together in Table 3 and described.

  From the above results, the polyisocyanurate foams of Comparative Examples 1 to 3 using an organically modified layered silicate having a moisture content outside the range of 20 to 90% by mass as the inorganic layered material have poor compressive strength and dimensional stability. Met.

  Moreover, the comparative example 4 which used the polyol mixture for which the ratio of the inorganic layered material with respect to 100 mass parts of foaming agents exceeds 100 mass parts, and the comparative example with the ratio of the layered silicate with respect to 100 mass parts of foam raw materials exceeding 1.0 mass part The polyisocyanurate foams Nos. 2 and 6 had a high viscosity of the polyol mixture, had poor handleability, and had poor adhesion to the face material.

  Further, the polyisocyanurate foam of Comparative Example 5 using a polyol mixture in which the ratio of the inorganic layered material to 100 parts by mass of the foaming agent is less than 5 parts by mass is inferior in compressive strength, dimensional stability, and water absorption. It was.

  On the other hand, the polyisocyanurate foams of Examples 1 to 7 obtained using the polyol mixture of the present invention have excellent physical properties such as dimensional stability, heat insulation, water absorption, compressive strength, and adhesion to a face material. It was. Among them, the foams of Examples 1 and 2 using an inorganic layered material treated with a quaternary ammonium salt and then treated with a silane coupling agent have a low polyol mixture viscosity and excellent handleability. It was a polyisocyanurate foam with few voids. And the polyisocyanurate foam of Example 1 which further used the compound which has a morpholine ring in a molecule | numerator is excellent in adhesiveness with a face material, and can be used especially suitably as a foam board. there were.

  The polyisocyanurate foam of the present invention can be used as a heat insulating material with little environmental load, and can be suitably used as a building material for a residential panel or the like.

Claims (7)

A method for producing a polyisocyanurate foam, which comprises foam-curing a foam raw material containing a polyol mixture containing at least a polyol, an inorganic layered material, and a foaming agent, an isocyanate composition, and a catalyst,
As the foaming agent, pentane is used,
As the inorganic layered material, an organic layered silicate having a water content of 20 to 90% by mass, which is obtained by treating a layered silicate with a quaternary ammonium salt,
As the catalyst, a catalyst containing a trimerization catalyst is used.
As said polyol mixture, 5-100 mass parts of said inorganic layered materials are contained with respect to 100 mass parts of said foaming agents, and layered silicate is 0.1-1.0 masses with respect to 100 mass parts of said foam raw materials. A method for producing a polyisocyanurate foam, which comprises using the inorganic layered material so as to contain a part.   2. The production of a polyisocyanurate foam according to claim 1, wherein the polyol mixture is prepared by previously dispersing the inorganic layered material in the polyol to form a dispersion solution, and then dispersing the dispersion solution in the foaming agent. Method.   The manufacturing method of the polyisocyanurate foam of Claim 1 or 2 using what the said foaming agent contains 3-7 mass parts with respect to 100 mass parts of said foam raw materials as said polyol mixture.   The polyisocyanurate foam according to any one of claims 1 to 3, wherein the polyol mixture has a pentane / water molar ratio of 50/50 to 90/10. Production method.   5. The material according to claim 1, wherein the inorganic layered material is a layered silicate / quaternary ammonium salt in a mass ratio of the layered silicate to the quaternary ammonium salt of 75/25 to 35/65. The manufacturing method of the polyisocyanurate foam as described in one.   The method for producing a polyisocyanurate foam according to any one of claims 1 to 5, wherein a material obtained by further treating the organically modified layered silicate with a silane coupling agent is used as the inorganic layered material.   The method for producing a polyisocyanurate foam according to any one of claims 1 to 6, wherein the quaternary ammonium salt used for the organic treatment of the layered silicate is a tetraalkylammonium salt.