JP4541970B2 - Polyisocyanurate foam and foam board using the same - Google Patents

Description

  The present invention relates to a polyisocyanurate foam excellent in heat insulation and dimensional stability, and a foam board using the same.

  Among various urethane foams, isocyanurate foams are suitably used for building material panels and the like because they are excellent in heat insulation and flame retardancy and have high strength. 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.

  However, pentane is a foaming agent that is friendly to the global environment and hardly affects ozone destruction. However, since the compatibility with active hydrogen compounds such as polyol is low, a polyol mixture containing pentane has poor storage stability. However, the resulting foam has insufficient dimensional stability and has a problem of shrinking over time.

On the other hand, normal pentane and isopentane, which are chain hydrocarbons among pentane, have better dimensional stability of the foam than cyclopentane, which is a cyclic hydrocarbon. As shown, normal pentane or a mixture of normal pentane and cyclopentane is used as a blowing agent.
JP 2002-121252 A

  However, normal pentane and isopentane are special flammables that fall under Class 4 of the Fire Service Law, and lack handling properties during use. In addition, normal pentane and isopentane have good dimensional stability of the resulting foam compared to cyclopentane, but the compatibility with the polyester polyol is poor and cannot be mixed with the polyol in a short time. Productivity is inferior, and not only the bubbles in the foam are likely to be non-uniform, but also the foaming gas generated when using normal pentane or isopentane is higher than the foaming gas generated when using only cyclopentane. Furthermore, since the thermal conductivity is high, the heat insulation performance of the resulting polyisocyanurate foam tends to be lower than when only cyclopentane is used as the foaming agent.

  On the other hand, when cyclopentane is used as a foaming agent, foaming tends to be rapid, resulting in voids in the foam, poor moldability, insufficient dimensional stability, and shrinkage over time. It had the problem of being easy.

  Therefore, in view of the above-mentioned problems, the present invention mainly aims to protect the global environment, and without using chlorofluorocarbon as a foaming agent, a polyisocyanurate foam excellent in dimensional stability, heat insulation and flame retardancy, and the same It is to provide a foam board using the above.

  The present inventor has made various studies on improvement of dimensional stability defects such as shrinkage of foams over time and non-uniformity of foam cells, which occurs when cyclopentane is used as a foaming agent for polyisocyanurate foams. As a result, the inventors have found that these problems can be solved by using a specific catalyst, and that a polyisocyanurate foam having good dimensional stability, excellent heat insulating properties, flame retardancy, and the like can be obtained, leading to the present invention.

That is, the polyisocyanurate foam of the present invention is a polyisocyanate obtained by reacting an isocyanate component comprising an aromatic polyisocyanate compound with a polyol component containing a foaming agent, a foaming aid, a catalyst, a foam stabilizer and a polyol. A nurate foam, an aromatic polyester polyol having two or more hydroxyl groups is used as the polyol, cyclopentane is used as the foaming agent, water is used as the foaming aid, and potassium acetate is used as the catalyst. A nurating catalyst containing 25 to 200 parts by mass of potassium octylate per 100 parts by mass, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine , bis (2-dimethylaminoethyl) ether, N, N-dimethylaminoethoxyethanol and N, N, N′-trimethylamino ester One or more amine catalysts selected from tilethanolamine, a mixed catalyst containing 3 to 25 parts by mass of the amine catalyst with respect to 100 parts by mass of the nurating catalyst, the foaming agent, and the foaming aid the molar ratio (blowing agent / blowing aid) with a 70 / 30-95 / 5, so that the isocyanate index is from 270 to 360, is reacted with the polyol component and the isocyanate component, resulting poly The isocyanurate foam contains 0.5 to 3% by mass of the catalyst and 0.5 to 2.5% by mass of the nurated catalyst .

According to the present invention, the catalyst comprises a nurating catalyst containing 25 to 200 parts by mass of potassium octylate with respect to 100 parts by mass of potassium acetate, and an amine catalyst, and the amine catalyst is added to 100 parts by mass of the nurating catalyst. Using a mixed catalyst containing 3 to 25 parts by mass, 0.5 to 3% by mass of the catalyst and 0.5 to 2.5% by mass of the nurated catalyst were contained in the resulting polyisocyanurate foam. Thus , even if only cyclopentane is used as the foaming agent , a product with good dimensional stability and good appearance can be obtained. Further, the thermal conductivity of the foaming gas is low and the heat insulation effect is high. And since the nurateization has progressed sufficiently, the foam has high strength and excellent flame retardancy, and since it has moderate flexibility, a face material having an aluminum layer Adhesiveness with a cover material such as is good, and can be suitably used as a foam board.

  Moreover, it is preferable that the polyisocyanurate foam of this invention is a thing obtained by mix | blending 160-240 mass parts of said isocyanate components with respect to 100 mass parts of said polyol components. This makes it possible to obtain a polyisocyanurate foam having good miscibility between the isocyanate component and the polyol component during the production of the polyisocyanurate foam and having high flame retardancy and heat insulation.

  Moreover, it is preferable that the said polyol is obtained using what has a hydroxyl value of 200-350 [KOHmg / g]. According to this, since the foam does not become too rigid, the adhesiveness with the skin material is good, and it can be suitably used as a foam board.

  Moreover, the said polyisocyanurate foam is obtained by using what further contains a phosphate ester type flame retardant as said polyol component, and 1-8 mass of said phosphate ester type flame retardants. % Content is preferable. According to this, a flame retardance can be provided, without impairing heat insulation and dimensional stability.

  On the other hand, the foam board of the present invention has one or more aluminum layers on at least one surface of the polyisocyanurate foam, and the total thickness of the aluminum layers is 3 to 40 μm, and the polyisocyanate foam The skin material in which the resin layer is formed is affixed on the surface contact | abutted to. The above-mentioned polyisocyanurate foam has good adhesion to the skin material, and the foamed board thus obtained has excellent flame retardancy. Therefore, the non-flammability specified in the ISO 5660 cone calorimeter test is used. It can be used as a material.

  According to the present invention, an aromatic polyester polyol having two or more hydroxyl groups is used as a polyol, and a nurating catalyst containing 25 to 200 parts by mass of potassium octylate per 100 parts by mass of potassium acetate as a catalyst; Using the mixed catalyst, the isocyanate component and the polyol component were mixed so that the isocyanate index was 270 to 360, thereby improving the dimensional stability defect that occurred when cyclopentane was used as the foaming agent. Polyisocyanurate foam excellent in heat resistance and flame retardancy. Moreover, since normal pentane etc. do not need to be used as a foaming agent, the handleability of a foaming agent is favorable. And the polyisocyanurate foam obtained in this way has favorable adhesiveness with a skin material, and can be utilized as a foam board with a high flame-retardant and heat insulation effect.

  The polyisocyanurate foam of the present invention is a urethane fold having an isocyanurate ring, and includes at least an isocyanate component composed of an aromatic polyisocyanate compound, a foaming agent, a foaming aid, a catalyst, a foam stabilizer, and a polyol. It is obtained by reacting with a polyol component.

  Hereinafter, each component used for this invention is demonstrated in detail.

  The aromatic polyisocyanate compound used as the isocyanate component of the polyisocyanurate foam of the present invention is not particularly limited as long as it is used for general urethane resin foams. For example, phenylene diisocyanate, tolylene diisocyanate, xylylene diene Examples include isocyanate, diphenylmethane diisocyanate, dimethyldiphenylmethane diisocyanate, triphenylmethane triisocyanate, naphthalene diisocyanate, polymethylene polyphenyl polyisocyanate, and among them, polymethylene polyphenyl polyisocyanate (crude MDI) is preferable.

  And the said aromatic polyisocyanate compound may be used independently, may be used as 2 or more types as a mixture, Furthermore, aliphatic polyol or alicyclic isocyanate, and the said isocyanate compound are used for a polyol. An isocyanate group-terminated prepolymer obtained by reacting with each other, an isocyanurate compound having an isocyanate group obtained by trimerizing an isocyanate compound, and the like may be mixed and used.

  The polyol component of the polyisocyanurate foam of the present invention contains at least a foaming agent, a foaming aid, a catalyst, a foam stabilizer and a polyol.

  As the polyol, an aromatic polyester polyol having two or more hydroxyl groups at the terminal or side chain, obtained by condensing a polyfunctional polyol having two or more functions and a polybasic acid is used.

  Multifunctional polyols include bifunctional polyols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butanediol, pentanediol, neopentylglycol, hexanediol, cyclohexanedimethanol, bisphenol A, bisphenol F. , Bisphenol S, etc., or compounds obtained by addition polymerization of alkylene oxides of ethylene oxide or propylene oxide, polyethylene glycol, polypropylene glycol, etc.), trifunctional polyols (trimethylolpropane, glycerin, etc., or alkylene oxides thereof) , Etc.), polyfunctional polyols (pentaerythritol, dipentaerythritol, sorbite) Le, saccharides, or these compounds by addition polymerization of alkylene oxides, etc.).

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

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

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

  The hydroxyl value is preferably 200 to 350 [KOH mg / g], more preferably 220 to 330 [KOH mg / g]. If the hydroxyl value is within the above range, the resulting polyisocyanurate foam will not be too stiff and will not become soft, so it has good adhesion to the skin material and is suitable as a foam board. It can be.

  Moreover, it is preferable that a viscosity is 10,000 cps or less, More preferably, it is 6000-300 cps.

  Cyclopentane is used as the blowing agent. Moreover, water is used as the foaming aid. The molar ratio of the foaming agent to the foaming aid (foaming agent / foaming aid) is blended in the polyol component so as to be 70/30 to 95/5, preferably 75/25 to 90/10. It is. When the ratio of the foaming agent is less than 70, the foam is likely to be rigid, the adhesiveness to the skin material, etc. is likely to be poor, and the heat insulation is likely to be inferior, and further, the foam shrinks over time. Dimensional stability tends to be inferior. On the other hand, if the ratio of the foaming agent is larger than 95, it is difficult to obtain sufficient heat generation in the urethane reaction between the polyol component and the isocyanate component, so that nurateization tends to be insufficient, and the strength of the foam decreases. The flame retardancy tends to be inferior.

  And it is preferable that content of the foaming agent in a polyol component shall be 10-30 mass%, More preferably, it is 15-25 mass%. Moreover, it is preferable that content of a foaming adjuvant shall be 0.2-2 mass%, More preferably, it is 0.5-1.5 mass%.

  Moreover, it is preferable that content of a foaming agent in a polyisocyanurate foam is 5-15 mass%, More preferably, it is 7-13 mass%. Moreover, it is preferable that content of a foaming adjuvant is 0.1-1 mass%, More preferably, it is 0.2-8 mass%. If the content of the foaming agent and foaming aid in the polyisocyanurate foam is within the above range, an isocyanurate foam that is lightweight, excellent in handleability and workability, and excellent in heat insulation can be obtained. .

  As a catalyst, a mixed catalyst of 25 to 200 parts by mass of potassium octylate with respect to 100 parts by mass of potassium acetate and an amine catalyst is used, and the content of potassium octylate is 100 parts by mass of potassium acetate. On the other hand, it is preferable that it is 30-190 mass parts.

  When the content of potassium octylate in the catalyst is less than 25 parts by mass with respect to 100 parts by mass of potassium acetate, the fluidity of the resin in the foaming stage is inferior, and the resulting polyisocyanurate foam has voids and wrinkles. Since it tends to occur, the moldability tends to be inferior. On the other hand, when the amount exceeds 200 parts by mass, the nucleation reaction becomes insufficient, so that the resulting polyisocyanurate foam tends to have insufficient strength, and the adhesiveness of the skin material, etc. described later is insufficient. It tends to be sufficient, making it difficult to use as a foam board.

  And as an amine catalyst, there is no limitation in particular and what can be used when manufacturing a usual urethane foam can be utilized, for example, monoamines (N, N-dimethylcyclohexylamine, N, N-dicyclohexylmethylamine, triethylamine) N, N-dimethylbenzylamine, etc.), cyclic monoamines (pyridine, N-methylmorpholine, N-ethylmorpholine, etc.), diamines (N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethyl-1,3-propanediamine, N, N, N ′, N′-tetramethyl-1,3-butanediamine, N, N, N ′, N′-tetramethyl Hexanediamine, methylene-bis (dimethylcyclohexylamine), N, N, N ′, N′-tetraethylethylenediamine, etc.) Triamines (N, N, N ′, N ′, N ″ -pentamethyldiethylenetriamine, N, N, N ′, N ′, N ″ -pentamethyldipropylenetriamine, 2,4,6-tris (dimethylaminomethyl ) -Phenol and the like, ether diamines (bis (2-dimethylaminoethyl) ether, 2- (N, N-dimethylamino) ethyl-3- (N, N-dimethylamino) propyl ether, 4,4′- Oxydimethylene dimorpholine, etc.), cyclic polyamines (triethylenediamine, N, N′-dimethylpiperazine, N, N′-diethylpiperazine, N, N-dimethylaminoethylmorpholine, 1-isobutyl-2-methylimidazole, 1-butoxy-2-methylimidazole), alkanolamines (N, N, N′-trimethylamino) Ethylethanolamine, N, N, N′-trimethylaminopropylethanolamine, 2- (2-dimethylamino-ethoxy) ethanol, N, N-dimethylaminoethanol, N, N-trimethyl-1,3-diamino-2 -Propanol, N-methyl-N '-(2-hydroxyethyl) -piperazine, etc.), among others, bis (2-dimethylaminoethyl), which is highly effective in promoting the reaction between water and isocyanate groups Ether, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, N, N, N′-trimethylaminoethylethanolamine, N, N ′, N ″ -tris (3-dimethylaminopropyl) hexahydro- S-triazine and N, N-dimethylcyclohexylamine are preferable, and N, N, N ′, N is particularly preferable. , N "- pentamethyldiethylenetriamine, bis (2-dimethylaminoethyl) ether, N, is N- dimethylaminoethoxy ethanol. In addition, as an amine catalyst, you may use together the said compound 2 or more types.

  The content of the amine catalyst in the catalyst is preferably 3 to 25 parts by mass, more preferably 4 to 20 parts by mass with respect to 100 parts by mass of the nurating catalyst. When the content of the amine catalyst is less than 3 parts by mass with respect to 100 parts by mass of the nurating catalyst, the foaming speed tends to be slow during the production of the polyisocyanurate foam, and the cells of the foam are not uniform. Therefore, the air bubbles tend to be coarse, and the heat insulating property tends to be inferior. On the other hand, when the amount is more than 25 parts by mass, the foaming speed tends to be high, the foam cell becomes finer, voids and wrinkles are likely to occur, the moldability tends to be poor, and the dimensional stability tends to be poor. It is.

  And it is preferable to mix | blend in a polyol component so that content of the catalyst in a polyol component may contain 0.5-3 mass% in the polyisocyanurate foam obtained, More preferably, it is 1-2.5. % By mass. Moreover, it is preferable to mix | blend in a polyol component so that content of a nurating catalyst may contain 0.5-2.5 mass% in the polyisocyanurate foam obtained, More preferably, it is 1-2 mass%. It is.

  If the content of the catalyst and the nurating catalyst in the polyisocyanurate foam is within the above range, the amount of generation of voids and wrinkles is small, the appearance is good, the moldability is excellent, and the polyisocyanate has a high heat insulation effect. An isocyanurate foam can be obtained.

  As the foam stabilizer, 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”, “TEGOSTAB-B8870” commercially available from GOLDSHMIT, and “SF2938F” commercially available from Toray Dow Corning Silicone. ”,“ SF2939 ”and the like can be preferably used.

  And although content of the foam stabilizer in a polyol component changes with isocyanate compounds and polyol to be used, it mix | blends in a polyol component so that it may become 0.1-2 mass% in the polyisocyanurate foam obtained. Preferably, it is 0.2 to 1.5% by mass.

  In the present invention, a flame retardant may be added to the polyol component.

  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 Phosphoester compounds such as bromoneopentyl) phosphate are mentioned. Among them, phosphate ester compounds are preferable, and tris (chloropropyl) phosphate, trie are particularly preferable. Til phosphate and tricresyl phosphate.

  And although content of the flame retardant in a polyol component changes with isocyanate compounds and polyol to be used, it is mix | blended in a polyol component so that it may contain 1-8 mass% in the polyisocyanurate foam obtained. Preferably, it is 2 to 6% by mass. When the content of the flame retardant in the polyisocyanurate foam is less than 1% by mass, the effect of improving flame retardancy by the flame retardant is hardly obtained, and when the content is more than 8% by mass, the foam becomes soft. Therefore, heat insulation and dimensional stability may be inferior.

  Furthermore, you may add various additives, such as a viscosity reducing agent, a face material adhesive improvement agent, and a bubble refiner, in a polyol component as needed.

  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. Further, 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. Further, 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. The content of these additives is not particularly limited, but it is preferably blended in the polyol component so as to be contained in an amount of 0.1 to 4% by mass in the resulting polyisocyanurate foam.

  The polyisocyanurate foam of the present invention contains at least an isocyanate component composed of the aromatic polyisocyanate compound, the polyol, a foaming agent, a foaming aid, a foam stabilizer, and a catalyst, and if necessary, a flame retardant, The compounding ratio with a polyol component containing various additives such as a viscosity reducer, a face material adhesion improver, and a cell micronizer is set so that the isocyanate index is 270 to 360, preferably 290 to 330, for example. Can be obtained by reacting polyol and isocyanate by collision mixing or the like.

  If the isocyanate index is less than 270, the formation of nurate rings tends to be reduced, the resulting polyisocyanurate foam is insufficient in strength, and flame retardancy tends to be inferior. Since it becomes too rigid, the adhesion of the skin material is inferior, the curing becomes insufficient, and voids, wrinkles, etc. are likely to occur, and the moldability is inferior.

  And it is preferable that the mixing ratio of an isocyanate component and a polyol component is 160-240 mass parts with respect to 100 mass parts of polyol components, More preferably, it is 180-220 mass parts. If the mixing ratio is as described above, the viscosity of the mixed solution does not become too high, so the miscibility of the isocyanate component and the polyol component is good.

The polyisocyanurate foam thus obtained has a density of 36 to 27 kg / m ³ , a thermal conductivity of 19 to 22 mW / mK, a closed cell ratio of 90% or more, and a high heat insulating property. . 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.

  Next, the foam board of the present invention will be described.

  The foam board in the present invention is obtained by attaching a skin material to at least one surface of the outer periphery of the polyisocyanurate foam of the present invention.

  And the foam board of the present invention, for example, using a continuous laminator, on the skin material (lower surface material) that is continuously supplied, the foamed liquid mixed with the isocyanate component and the polyol component is spouted, At the same time, a skin material (upper surface material) is placed on the foaming liquid, sandwiched and foamed and cured.

  The skin material used in the foamed board of the present invention has a resin layer such as polyethylene resin, acrylic resin, epoxy resin, etc. on the surface in contact with the polyisocyanurate foam, and at least one aluminum layer It is. Further, a fiber layer such as kraft paper, nonwoven fabric or woven fabric may be interposed between the resin layer and the aluminum layer.

  The resin layer is preferably a polyethylene resin layer in view of adhesiveness with the polyisocyanurate foam.

  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 μm or more, the heat insulating property can be improved, and if it is 9 μm or more, it can be combined with the present foam and used as a flame retardant material defined in ISO5660. 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.

  The foam board to which the skin material is attached is excellent in flame retardancy and heat insulation, and can also be used as a non-combustible material determined by the ISO 5660 cone calorimeter test.

  In addition, the foam board of this invention may use fiber mats, such as a glass mat, as a core material as needed. Thereby, the shape as a foam board can be stably maintained for a long time.

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

[Manufacture of foam board]
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. Then, the mixture material was injected into a mold made of side-opening aluminum having an inner dimension of 500 mm × 500 mm × 48 mm, which was provided with a skin material on which the polyethylene resin coating film was formed on the upper and lower surfaces and heated to 65 ° C., After 6 minutes, the mold was removed to obtain foam boards of test bodies 1 to 16.

[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. The thermal conductivity was judged to be good if it was 22 (mW / mK) or less.

(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%, it was evaluated as ◯, when it was 1 to 3%, Δ when it was 3% or more.

(Compressive strength)
Performed by a method in accordance with JIS A 9511, a strength at break of the foam were measured, those of more than 1.5 kgf / cm ² ○, the 0.8~1.5kgf / cm ² △, 0.8kgf / Less than cm ² was set as x.

(appearance)
The obtained specimens were each left for 1 day, the surface state of the foam was observed, and the number and size of voids, the presence or absence of wrinkles, the degree of unevenness, etc. were visually observed.

(Adhesiveness with skin material)
A cut of 100 mm × 100 mm square was made in the skin material of the obtained test body, one side of the skin material was peeled off 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 skin material, the skin material was peeled from the foam, and the maximum load at that time was measured. When the maximum load was 1.5 kgf or more, it was evaluated as ◯, when it was 1.0 to 1.5 kgf, Δ when it was less than 1.0 kgf.

(Nonflammability test)
The test was carried out by a method based on the ISO 5660 corn calorimeter test, and it was considered acceptable if the following criteria (1) to (3) could be satisfied.
(1) The total calorific value for 20 minutes after the start of heating is 8 MJ / m ² or less.
(2) There should be no cracks or holes penetrating to the back side, which is harmful to fire prevention, for 20 minutes after the start of heating.
(3) The maximum exotherm rate should not exceed 200 kW / m ² for 20 minutes after the start of heating for 10 seconds or more.

The said test is done about the test bodies 1-16, and a result is put together in Table 2 and described.

  From the above results, the foam of the test body 9 in which the content of potassium octylate is more than 200 parts by mass with respect to 100 parts by mass of potassium acetate as the nurating catalyst has dimensional stability, strength, and moldability. It was inferior.

  The foam of the test body 10 having an isocyanate index greater than 360 was inferior in moldability and was not suitable as a foam board because of poor adhesion to the skin material.

  The foam of the test body 11 which did not use potassium acetate as a nurating catalyst is inferior in dimensional stability, strength and moldability, and is not suitable as a foam board because of poor adhesion to the skin material. Met.

  The foam of the test body 12 that did not use potassium octylate had very large amounts of voids and wrinkles, poor appearance, and poor moldability.

  The foam of the test body 13 using a quaternary ammonium salt as a nurating catalyst had a poor appearance and inferior moldability, and was also inferior in dimensional stability and strength.

  Specimen 14 using isopentane instead of cyclopentane has a slight amount of voids and wrinkles, poor appearance, poor moldability, high thermal conductivity, and poor heat insulation. there were.

  The foam of the test body 15 obtained by setting the ratio of the foaming agent to less than 70 in the molar ratio of the foaming agent to the foaming aid (foaming agent / foaming aid) has high thermal conductivity and poor heat insulating properties. The foam of the test body 16 obtained by increasing the ratio of the foaming agent to more than 95 was low in strength and further lacked dimensional stability.

  On the other hand, as a catalyst, a mixed catalyst of a nurating catalyst containing 25 to 200 parts by mass of potassium octylate with respect to 100 parts by mass of potassium acetate and an amine catalyst is used, and the molar ratio of foaming agent to foaming aid (foaming) The foams of Specimens 1 to 8 obtained with 70/30 to 95/5 as the additive / foaming aid have good dimensional stability, strength and appearance, and excellent moldability. Adhesiveness was good, and it could be used suitably as a foam board. And the foam board of the test bodies 1, 2 and 8 obtained by sticking the skin material having an aluminum layer of 3 to 40 μm has extremely high flame retardancy, and in particular, a flame retardant is blended as a raw material of the foam. Furthermore, as the skin material, the foam board of the test body 1 using the aluminum layer having a thickness of 9 to 40 μm could be used as a non-combustible material defined in the ISO 5660 cone calorimeter test.

The polyisocyanurate foam and the foam board of the present invention can be used as a heat insulating material with a low environmental load, and can be particularly suitably used as a building material such as a residential panel.

Claims (6)

A polyisocyanurate foam obtained by reacting an isocyanate component composed of an aromatic polyisocyanate compound and a polyol component containing a foaming agent, a foaming aid, a catalyst, a foam stabilizer and a polyol,
As the polyol, an aromatic polyester polyol having two or more hydroxyl groups is used,
Cyclopentane is used as the foaming agent,
As the foaming aid, water is used,
Examples of the catalyst include a nitrating catalyst containing 25 to 200 parts by mass of potassium octylate per 100 parts by mass of potassium acetate, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine , bis (2-dimethylamino) Ethyl) ether, N, N-dimethylaminoethoxyethanol, and one or more amine catalysts selected from N, N, N′-trimethylaminoethylethanolamine, and the amine with respect to 100 parts by mass of the nurated catalyst. Using a mixed catalyst containing 3 to 25 parts by mass of catalyst,
The molar ratio (foaming agent / foaming aid) between the foaming agent and the foaming aid is 70/30 to 95/5,
The isocyanate component and the polyol component are reacted so that the isocyanate index is 270 to 360. In the resulting polyisocyanurate foam, the catalyst is 0.5 to 3% by mass, and the nurating catalyst is 0. A polyisocyanurate foam characterized by containing 5 to 2.5% by mass .   The polyisocyanurate foam according to claim 1, wherein the polyisocyanurate foam is obtained by blending 160 to 240 parts by mass of the isocyanate component with respect to 100 parts by mass of the polyol component.   The polyisocyanurate foam according to claim 1 or 2, wherein the polyisocyanurate foam is obtained by using a polyol having a hydroxyl value of 200 to 350 [KOHmg / g] as the polyol. The said polyisocyanurate foam is obtained using what further contains the phosphate ester type flame retardant as said polyol component, and contains 1-8 mass% of the said phosphate ester type flame retardant. The polyisocyanurate foam according to any one of claims 1 to 3 .   At least one surface of the polyisocyanurate foam according to any one of claims 1 to 4 has one or more aluminum layers, and the total thickness of the aluminum layers is 3 to 40 µm, A foam board characterized in that a skin material on which a resin layer is formed is affixed to a surface in contact with a polyisocyanate foam. The foam board according to claim 5 , which is a non-combustible material defined in ISO 5660 cone calorimeter test.