JP2018083909A - Hard isocyanurate foam composition and method for producing hard isocyanurate foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for hard isocyanurate foam that has reduced brittleness on the foam surface, and has high flame retardancy with an oxygen index of 30 or more.SOLUTION: A composition for hard isocyanurate foam contains an organic polyisocyanate (A), a polyglycidyl ester compound (B), a catalyst (C), a foaming agent (D), a foam stabilizer (E), and a flame retardant (F). An equivalent ratio between the organic polyisocyanate (A) and the polyglycidyl ester compound (B) [isocyanate group in (A)/ glycidyl group in (B)] is 5-15; the catalyst (C) is a tertiary amine catalyst; the flame retardant (F) is liquid at normal temperature; and the flame retardant (F) content is 5-20 wt.% in all the components.SELECTED DRAWING: None

Description

  The present invention relates to a flame retardant rigid foam composition containing oxazolidone and isocyanurate, and a method for producing the same.

  Rigid polyurethane foam is produced mainly by the reaction of isocyanate and polyol, and is used in a wide range of applications such as heat insulating materials and structural materials in buildings, storage tanks, ships and the like. In recent years, flame retardant technology for rigid polyurethane foams has been required due to strict operation of flame retardant standards and promotion of energy saving policies.

  Hard isocyanurate foams containing isocyanurate rings with high thermal stability obtained by trimerization of isocyanate are effective as a means to make rigid polyurethane foams flame-retardant. Conventionally, they have been widely used as flame-retardant materials. Yes.

  The formation reaction of rigid isocyanurate foam mainly consists of urethane group formation reaction (resinification reaction) by reaction of polyol and isocyanate, urea group formation reaction (bubble formation reaction) by reaction of isocyanate and water, and addition of trimerization of isocyanate. Isocyanurate group formation reaction (isocyanurate formation reaction). Among these urethane bonds, urea bonds, and isocyanurate bonds contained in the rigid isocyanurate foam, the thermal decomposition temperature of the isocyanurate bond is higher than that of the urethane bond or urea bond, and contributes to flame retardancy of the foam.

  Oxazolidone, imide, amide, carbodiimide and the like are known as other bonds having a higher thermal decomposition temperature than urethane bonds and urea bonds. Among these, as isocyanurate foams containing oxazolidone, a production method using an isocyanurate trimerization catalyst and a soluble Lewis acid complex other than a boron halide complex as a catalyst (see Patent Document 1), A composition using 0.1 to 0.6 equivalents of epoxide (see Patent Documents 2 and 3) has been reported.

  In the flame retardance of the foam referred to in Patent Document 1, sufficient flame retardancy cannot be obtained, and high flame retardancy demanded in recent years (for example, used for building wall surfaces defined in Chinese National Standard GB8624-2012) The B1 grade plate-like building material that is obtained cannot satisfy the oxygen index of 30 or more), and Patent Documents 2 and 3 refer to the thermal deterioration of the foam, but the flame retardancy is not Not touched. The epoxides mentioned in these documents are exemplified by polyglycidyl ether compounds represented by glycidyl ether of bisphenol A, but there is no description about polyglycidyl esters, and the flame retardancy of the resin itself is improved. There was room for.

  In order to impart sufficient flame retardancy, for example, Patent Document 4 discloses flame retardancy of rigid polyurethane foam using peelable graphite as a solid flame retardant. Graphite is a powder having a large particle size that is insoluble in isocyanate and polyol, and the flame retardant is unevenly distributed in the isocyanate and polyol raw material by sedimentation and aggregation. For this reason, when a solid flame retardant is included in the raw material liquid, there is a problem that a uniform foam cannot be obtained and the flame retardancy is lowered. Therefore, a flame retardant rigid foam using a composition that does not cause sedimentation or aggregation in the raw material is desired.

JP-A-51-74095 JP-A-62-270612 Japanese Patent Application Laid-Open No. 64-45422 JP-T-2002-532597

  The present invention has been made in view of the above-described background art, and an object thereof is to provide a rigid isocyanurate foam having low flame brittleness and a high flame retardancy having an oxygen index of 30 or more.

  As a result of repeated investigations, the present inventors have determined that the main bond generated in the foaming process is isocyanurate or oxazolidone having a high thermal decomposition temperature, and that the oxazolidone ring is formed from a specific glycidyl compound, thereby The inventors have found that this can be solved, and have reached the present invention.

  That is, the present invention includes the following embodiments.

  (1) Composition for rigid isocyanurate foam containing organic polyisocyanate (A), polyglycidyl ester compound (B), catalyst (C), foaming agent (D), foam stabilizer (E), and flame retardant (F) The equivalent ratio of the organic polyisocyanate (A) to the polyglycidyl ester compound (B) [isocyanate group in (A) / glycidyl group in (B)] is 5 to 15, and catalyst (C) Is a tertiary amine catalyst, the flame retardant (F) is liquid at room temperature, and the flame retardant (F) is contained in the total formulation in an amount of 5 to 20% by weight. .

  (2) The composition for rigid isocyanurate foam according to (1) above, wherein the polyglycidyl ester compound (B) is a diglycidyl ester compound.

  (3) The above (1) or (2), wherein the polyglycidyl ester compound (B) is a diglycidyl orthophthalate and the flame retardant (F) is a phosphoric acid ester compound which is liquid at room temperature. The composition for rigid isocyanurate foams described.

  (4) A hard isocyanurate foam obtained by mixing and foaming the composition for hard isocyanurate foam according to any one of (1) to (3) above.

  (5) Mix and foam the organic polyisocyanate (A) with a mixture of polyglycidyl compound (B), catalyst (C), foaming agent (D), foam stabilizer (E), and flame retardant (F). The method for producing a rigid isocyanurate foam, wherein the equivalent ratio of the organic polyisocyanate (A) to the polyglycidyl compound (B) [isocyanate group in (A) / glycidyl group in (B)] is 5 to 15 A hard isocyanic acid, characterized in that the catalyst (C) is a tertiary amine catalyst, the flame retardant (F) is in a liquid state at room temperature, and the flame retardant (F) is included in the total formulation in an amount of 5 to 20% by weight. A method for producing a nurate foam.

  (6) The method for producing a hard isocyanurate foam according to the above (5), wherein the molding temperature is room temperature.

  The brittleness in the present invention represents the degree of brittleness of the side surface of the hard isocyanurate foam, and the surface hardness was used as an index of brittleness.

  According to the present invention, a flame-retardant hard isocyanurate foam having a small foam surface brittleness and an oxygen index of 30 or more can be obtained.

  Hereinafter, the present invention will be described in detail.

  The composition for rigid isocyanurate foams of the present invention comprises an organic polyisocyanate (A), a polyglycidyl ester compound (B), a catalyst (C), a foaming agent (D), a foam stabilizer (E), and a flame retardant (F ), The equivalent ratio of the organic polyisocyanate (A) and the polyglycidyl ester compound (B) [isocyanate group in (A) / glycidyl group in (B)] is 5 The catalyst (C) is a tertiary amine catalyst, the flame retardant (F) is liquid at room temperature, and the flame retardant (F) is contained in the total formulation in an amount of 5 to 20% by weight. Features.

  As the organic polyisocyanate (A) used in the present invention, a compound having at least two isocyanate groups can be used. Such an organic polyisocyanate is not particularly limited. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5 Naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, tetramethylxylene diisocyanate, 1,6-hexamethylene diisocyanate, 4,4 '-Dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate Lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate , An isocyanate-containing prepolymer obtained by reaction of these with a polyol, and a mixture of two or more thereof.

  Furthermore, modified products of these isocyanates (urethane group, carbodiimide group, allophanate group, urea group, burette group, isocyanurate group, amide group, imide group, uretonimine group, uretdione group or oxazolidone group-containing modified product) and polymethylene Condensates (sometimes referred to as polynuclear bodies) such as polyphenylene polyisocyanate (polymeric MDI) are also included.

  Among them, the organic polyisocyanate (A) is a so-called dinuclear polymer, which is a mixture of diphenylmethane diisocyanate (MDI) each having two benzene rings and two isocyanate groups in one molecule, and a polynuclear product thereof. MDI is preferred.

  The polyglycidyl ester compound (B) used in the present invention is an arbitrary compound in which two or more glycidyl groups are esterified, and is an aromatic compound, heterocyclic compound, cyclic saturated hydrocarbon, cyclic unsaturated carbonization. It is a compound in which two or more glycidyl esters are bonded to hydrogen, acyclic saturated hydrocarbon, acyclic unsaturated hydrocarbon, inorganic group or the like directly or through other bonds. When there are three or more glycidyl groups in the compound, it is difficult to react with isocyanate during the foaming process, and the amount of glycidyl groups remaining in the foam increases. Therefore, a preferred polyglycidyl ester compound contains two glycidyl groups in the compound. A compound.

  The polyglycidyl ester compound is not particularly limited, but specific examples include malonic acid diglycidyl ester, succinic acid diglycidyl ester, maleic acid diglycidyl ester, adipic acid diglycidyl ester, fumarate diglycidyl ester, glutaric acid. Diglycidyl ester, 4,4'-diphenyldicarboxylic acid diglycidyl ester, 1,4-cyclohexanedicarboxylic acid diglycidyl ester, 4,4'-oxybisbenzoic acid diglycidyl ester, 4,4'-sulfonyldibenzoic acid diglycidyl Examples thereof include esters and 3,5-pyridinedicarboxylic acid diglycidyl ester. Of these, diglycidyl esters which are liquid at room temperature, such as orthophthalic acid diglycidyl ester, are more preferable. In order to impart flame retardancy, the diglycidyl ester compound may contain halogen (particularly bromine). The epoxy equivalent (g / equivalent) of a suitable polyglycidyl ester compound or a mixture thereof is 100 to 500, and is 100 to 200 when halogen such as bromine is not contained in the polyglycidyl ester compound. The individual epoxides included in the mixture may have equivalents outside this range.

  The equivalent ratio of the organic polyisocyanate (A) and the polyglycidyl ester compound (B) is such that the isocyanate group contained in (A) is in the range of 5 to 15 with respect to the glycidyl group contained in (B). When the equivalent ratio is less than 5, the flame retardancy deteriorates, and when it is more than 15, the foam becomes brittle.

  The catalyst (C) used in the present invention is a tertiary amine. Tertiary amines include, for example, triethylenediamine, dimethylcyclohexylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, N, N , N ′, N ″, N ″ ′, N ″ ′-hexamethyltriethylenetetramine, bis (dimethylaminoethyl) ether, 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro-S-triazine 2,4,6-tris (dimethylaminomethyl) phenol, 2,4-bis (dimethylaminomethyl) phenol, N-dimethylaminoethyl-N′-methylpiperazine, N, N, N ′, N′-tetra Methylhexamethylenediamine, 1,2-dimethylimidazole, 1-isobutyl-2-methylimidazole, N, -Amine compounds such as dimethylaminopropylamine, bis (dimethylaminopropyl) amine, N, N-dimethylaminoethanol, N, N, N'-trimethylaminoethylethanolamine, 2- (2-dimethylaminoethoxy) ethanol N, N, N′-trimethyl-N′-hydroxyethylbisaminoethyl ether, N- (3-dimethylaminopropyl) -N, N-diisopropanolamine, N- (2-hydroxyethyl) -N′- Examples include alkanolamines such as methylpiperazine, N, N-dimethylaminohexanol, 5-dimethylamino-3-methyl-1-pentanol, etc. These tertiary amine catalysts are used alone or in combination of two or more. You may do it.

  Among these tertiary amine catalysts, those having no isocyanuration activity do not foam, so, for example, 1 mol% of tertiary amine catalyst is added to a mixed liquid of organic polyisocyanate and polyglycidyl ester compound, and DSC is added after uniform stirring. A catalyst having both an exothermic peak accompanying the generation of isocyanurate observed at 50 to 100 ° C. and an exothermic peak accompanying the generation of oxazolidone seen at 200 to 300 ° C. is a preferable catalyst. Specifically, dimethylcyclohexylamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine, 1-isobutyl-2-methylimidazole, N, N, N ′, N′-tetramethylethylenediamine, etc. Can be mentioned.

Incidentally, in the infrared absorption spectrum of Form obtained using the above preferred catalyst, appearing as an absorption peak of the absorption 1745cm around ^-1 Karuboruniru groups derived from oxazolidone ring, formation of oxazolidone rings, 1705 cm ^-1 vicinity of This is confirmed as the shoulder peak of the absorption peak of the carbonyl group derived from the isocyanurate ring.

  In addition, a quaternary ammonium salt, an alkali metal salt of a carboxylic acid having 2 to 12 carbon atoms, an alkali metal salt of acethiacetone or salicylaldehyde, a Lewis acid complex salt of an amine, a metal catalyst, etc. may be used in combination as necessary. May be. However, catalysts with strong isocyanurate activity, such as quaternary ammonium salts and alkali metal salts of carboxylic acids having 2 to 12 carbon atoms, inhibit the production of oxazolidone and deteriorate the flame retardancy, so their use is restricted. Is done.

  The amount of the catalyst (C) added is preferably 0.1 to 15% by weight in the hard isocyanurate foam composition of the present invention. If it is less than the lower limit, foaming may be delayed and the isocyanate may be separated before foaming. If the upper limit is exceeded, foaming may become uneven and the foam may be cracked or ruptured, or the flame retardancy may be reduced.

  A commercially available physical foaming agent can be used as the foaming agent (D) used in the present invention. Although these foaming agents are not particularly limited, for example, chlorofluorocarbons, hydrochlorofluoroolefins, hydrochlorofluorocarbons, hydrofluoroolefins, hydrofluorocarbons, perfluorocarbons, halogen-based hydrocarbons having a low boiling point such as methylene chloride. Examples include carbons, hydrocarbons such as pentane and cyclopentane, gases such as air, nitrogen and carbon dioxide, or low-temperature liquids.

  Among them, since the ozone depletion potential (ODP) is small and the global warming potential (GWP) is small, HCFO-1233zd, its trans isomer, HCFO-1233xf, hydrochlorofluoroolefins such as dichlorofluorinated propene, HCFC-141b Hydrochlorofluorocarbons such as HDP-1234zf, E-HFO-1234ze, Z-HFO-1234ze, HFO-1234yf, E-HFO-1255ye, Z-HFO because ODP is zero and has a small GWP. -125ye, E-HFO-1336mzz, Z-HFO-1336mzz, hydrofluoroolefins such as HFO-1438mzz, HFC-134a, HFC-245, HFC-236, HFC-356, HFC-365mfc, H Hydrofluorocarbons such as C-227ea, propane, butane, pentane, hexane, hydrocarbon and the like cyclopentane are preferred.

  The amount of the foaming agent (D) added is preferably in the range of 5 to 20% by weight in the hard isocyanurate foam composition of the present invention. If the upper limit value is exceeded, the strength may decrease, and if it is less than the lower limit value, the foam density becomes higher than necessary, and the amount of raw material used increases, which may be uneconomical.

  As a foam stabilizer (E) used for this invention, the commercially available foam stabilizer used for manufacture of a polyurethane foam etc. are mentioned. Although it does not specifically limit as foam stabilizer (E), For example, surfactant is mentioned, Organic silicones, such as nonionic surfactants, such as an organosiloxane-polyoxyalkylene copolymer and a silicone-grease copolymer And surface active agents. These surfactants are not particularly limited. For example, L5420, L5340, L6188, L6877, L6889, L6900 manufactured by Momentive, B8040, B8155, B8239, B8244, B8330, B8443, B8450, B8460, B8462 manufactured by Evonik. B8465, B8466, B8467, B8481, B8484, B8485, B8486, B8496, B8870, B8871, SZ-1328, SZ-1642, SZ-1677, SH-193, DC-193 manufactured by Toray Dow Corning , DC5598 and the like.

  The amount of the foam stabilizer (E) added is preferably in the range of 0.1 to 10% by weight in the hard isocyanurate foam composition of the present invention. If the amount is less than the lower limit, the cell structure and cell size may not be stable, and a uniform foam may not be obtained. If the amount exceeds the upper limit, flame retardancy may be reduced.

  The flame retardant (F) used in the present invention is a liquid flame retardant at room temperature. Examples of the flame retardant that is liquid at room temperature include phosphate ester flame retardants, phosphazene flame retardants, and halogenated epoxy flame retardants.

  Examples of phosphate ester flame retardants include tris (chloroethyl) phosphate, tris (2-chloroisopropyl) phosphate, tris (1-chloro-2-propyl) phosphate, tris (dichloropropyl) phosphate, tetrakis (2-chloroethyl). ) Ethylene diphosphate, 2,2-bis (chloromethyl) -1,3-propanebis (chloroethyl) phosphate, tris (2,3-dibromopropyl) phosphate, tris (tribromoneopentyl) phosphate, 2,2- Bis (chloromethyl) trimethylene bis (bis (2-chloroethyl) phosphate), polyoxyalkylene bisdichloroalkyl phosphate, halogen-containing phosphate phosphonate oligomer ester (CR-830, manufactured by Daihachi Chemical Industry Co., Ltd.) -570, CR-509, etc.), trimethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, tri-2-ethylhexyl phosphate, tributyl phosphate, trixylenyl phosphate, triethyl phosphate, trioctyl phosphate, dimethylmethyl Phosphonate, diethyl phenyl phosphonate, dimethyl phenyl phosphonate, resorcinol diphenyl phosphate, ethyl phosphite, diethyl phosphite, ethyl ethylene phosphate oligomer (FR-PNX made by ICL, etc.), aromatic phosphoric acid oligomer ester (Resorcinol bisdiphenyl phosphate, resorcinol bisdixylenyl phosphate, bisphenol A bisdiphenyl phosphate Door, include the Daihachi Chemical Industry Co., Ltd. CR-735, etc.) and the like.

  Examples of the phosphazene flame retardant include cyclic phenoxyphosphazene (SPB-100L manufactured by Otsuka Chemical).

  Examples of the halogenated epoxy flame retardant include dibromophenyl glycidyl ether, dibromocresyl glycidyl ether (manac EB-200B), and the like.

  Among these, it is preferable to use a phosphate ester flame retardant, and tris (2-chloroisopropyl) phosphate is more preferable from an economical viewpoint.

  In the present invention, the normal temperature is 5 ° C to 35 ° C.

  The ratio of the flame retardant (F) added to the hard isocyanurate foam composition of the present invention is 5 to 20% by weight, preferably 8 to 12% by weight. When the flame retardant (F) is less than 5% by weight, the flame retardancy is lowered, and when it exceeds 20% by weight, the mechanical properties of the foam are lowered due to the plasticizing action, and there is a risk of causing a decrease in strength or shrinkage.

  In the hard isocyanurate foam composition of the present invention, in addition to the above (A) to (F), foam cracks generated during the foaming process, foam cracks at high temperatures of 200 ° C. or higher, and prevention of bursting A small amount of a polyol that reacts with isocyanate to form a urethane bond and a chemical blowing agent that reacts with isocyanate to form a urea bond may be added. When these addition amounts are increased, urethane bonds and urea bonds having a low thermal decomposition temperature are increased and flame retardancy is deteriorated. Therefore, the addition amount is preferably 5 mol% or less of all isocyanate-reactive groups. Although the polyol in the case of adding is not specifically limited, The hydroxyl value of 1-2000 (mgKOH / g) is preferable, and 10-800 (mgKOH / g) is further more preferable. The hydroxyl value can be calculated according to the method of JIS K1557.

  Polyols include, for example, polyether polyols obtained by ring-opening polymerization of alkylene oxide, polymer polyols obtained by radical polymerization of vinyl monomers in polyether polyols, polyhydric alcohols and polyhydric carboxylic acids. Polyester polyols obtained by condensation, polyester amide polyols obtained by polycondensation of polyhydric alcohols, polycarboxylic acids and amino alcohols, polylactone polyols obtained by ring-opening polymerization of lactones, polyhydric alcohols Polyols, acrylic polyols, polybutadiene polyols and their hydrogenated products, polyisoprene polyols and their hydrogenated products, partially saponified ethylene-vinyl acetate obtained by polycondensation of alcohols and carbonates Polymers, natural oil based polyols such as soybean or castor oil, halogenated polyols, phosphorus-based polyol, a phenol-based polyols, and the like. Of these, polyester polyols, halogen polyols, phosphorus polyols, and phenol polyols are preferred because of excellent flame retardancy.

  Examples of the polyester polyols include polyester polyols derived from adipic acid, orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, succinic acid, azelaic acid, sebacic acid, linoleic acid, dimethyl terephthalate, and polyethylene terephthalate. However, it also includes polyester polyols produced from polyethylene terephthalate waste, dimethyl terephthalate process waste, nylon waste, trimethylolpropane or pentaerythritol waste, phthalate polyester waste, and the like. Also included are lactone-based polyester polyols obtained by ring-opening polymerization of cyclic esters such as ε-caprolactone and methylvalerolactone. Among the polyester polyols, an aromatic polyester polyol derived from phthalic acid and a polyhydric alcohol is preferable for imparting flame retardancy.

  Examples of the halogen-based polyol include halogen-containing polyols obtained by ring-opening polymerization of epichlorohydrin and trichlorobutylene oxide, halogenated polyols such as brominated pentaerythritol-based polyols, and tetrabromophthalic acid polyesters.

  Examples of the phosphorus-based polyol include halogen-based phosphate esters or non-halogen-based polyols such as so-called phosphorus-containing polyols having a hydroxyl group in a phosphoric acid compound (FC-450 manufactured by Adeka Co., Ltd., Filol 6 manufactured by ICL, Filol PNX, etc.) Examples thereof include phosphate esters and oligomers thereof.

  As the phenolic polyol, for example, a phenol derivative such as phenol or nonylphenol or alkylphenol is modified with Mannich using a secondary amine such as formaldehyde and diethanolamine, ammonia or a primary amine, and an alkylene oxide such as ethylene oxide or propylene oxide. And Mannich polyols obtained by ring-opening addition polymerization.

  In the hard isocyanurate foam composition of the present invention, other additives such as a foam breaker, an antioxidant, an ultraviolet absorber, a plasticizer, a pigment / dye, an antibacterial agent / antifungal agent, etc. Various known additives can be added. As the addition amount of these various additives, the proportion of the hard isocyanurate foam composition of the present invention is preferably 5% by weight or less. If it exceeds 5% by weight, flame retardancy and strength may be reduced.

  The production method of the rigid isocyanurate foam of the present invention comprises an organic polyisocyanate (A), a polyglycidyl compound (B), a catalyst (C), a foaming agent (D), a foam stabilizer (E), and a flame retardant (F ) Is mixed and foamed to produce a rigid isocyanurate foam, the equivalent ratio of the organic polyisocyanate (A) to the polyglycidyl compound (B) [isocyanate groups in (A) / in (B) Glycidyl group] is 5 to 15, the catalyst (C) is a tertiary amine catalyst, the flame retardant (F) is liquid at room temperature, and the flame retardant (F) is 5 to 20% by weight in the total formulation. It is characterized by including.

  Conventionally, in the hard isocyanurate foam, since unreacted isocyanate tends to remain on the foam surface, it is necessary to heat the mold in order to improve the brittleness of the foam surface. By using the product, a hard isocyanurate foam having a small brittleness on the foam surface can be obtained even when the mold temperature (molding temperature) of the mold is normal.

  As a manufacturing method of the rigid isocyanurate foam of this invention, well-known manufacturing methods, such as slab foaming, continuous production foaming, and injection mold foaming, are mentioned. In the present invention, injection mold foaming is preferred in which the brittleness of the foam surface is further suppressed.

The core density of the rigid isocyanurate foam obtained by the production method of the present invention is preferably in the range of 20 to 100 kg / m ³ . If it exceeds 100 kg / m ³ , the cost is high and uneconomical, and if it is less than 20 kg / m ³ , the strength characteristics and the like may be inferior.

  The rigid isocyanurate foam obtained by the production method of the present invention can be used for various applications in which a rigid polyurethane foam is generally used. For example, the rigid isocyanurate foam can be used for a heat insulating material such as a heat insulating material or a structural material related to construction or civil engineering.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition,% description in an Example is a basis of weight unless there is particular notice.

<< Reactivity, evaluation of core density >>
<Foam evaluation>
At room temperature (20-25 ° C.), the mixture of organic polyisocyanate (A) and other components (G) was weighed to a total of 250 g, adjusted to a temperature of 20 ° C., and then the two liquids were mixed at a stirring speed of 6000 rpm. The mixture was stirred and mixed for 2 seconds, poured into a 150 × 150 × 200 mm upper open aluminum container at room temperature, and free foamed.

<Core density of foam>
After foaming for 30 minutes, the foam which was free-foamed in the container was removed from the mold, the central part was cut into dimensions of 100 mm × 100 mm × 120 mm, and the core density was calculated by measuring the dimensions and weight.

<< Evaluation of foam surface brittleness and oxygen index >>
<Evaluation of brittleness on foam surface>
When the foam surface is brittle, the surface hardness is low, and when the brittleness is small, the hardness is high. Therefore, the surface hardness was used as an alternative index of brittleness.

  30 minutes after foaming, the foam that was free-foamed in the container was removed, and the hardness of the foam side surface was measured with a durometer (Asker C-type hardness meter). .

<Evaluation of flame retardancy>
After the foam sample was cured for 3 days in an atmosphere at 20 ° C., a 10 × 10 × 120 mm sample was cut out from the center of the foam, and the oxygen index was measured according to JIS K7201-2.

As raw materials described in Table 1, the following were used.
Glycidyl ester: Orthoglycic acid diglycidyl ester (epoxy equivalent = 185) manufactured by Nagase ChemteX Corporation
Glycidyl ether: 2,2-bis (4-glycidylphenyl) propane flame retardant manufactured by Tokyo Chemical Industry Co., Ltd .: Tris (2-chloroisopropyl) phosphate manufactured by ICL-IP (trade name: Pyrol PCF)
Foaming agent A: 1,1,1,3,3-pentafluorobutane (trade name: Solcan HFC-365mfc) manufactured by Nippon Solvay
Foam stabilizer A: Silicone surfactant (trade name: B-8465) manufactured by Toray Dow Corning
Catalyst A: A tertiary amine catalyst manufactured by Tosoh Corporation (trade name: TOYOCAT-DT)
Catalyst B: Quaternary ammonium salt catalyst manufactured by Tosoh Corporation (trade name: TOYOCAT-TRX)
Isocyanate: Polymeric MDI (trade name: MR-200, NCO content = 31.0%) manufactured by Tosoh Corporation.

  The results of Examples 1 to 3 and Comparative Examples 1 to 5 are shown in Table 1.

Examples 1-3
In accordance with the formulation shown in Table 1, after blending a mixture of components other than the organic polyisocyanate (A), the mixture was stirred and mixed with the organic polyisocyanate (A) to obtain a hard isocyanurate foam. In all cases, the brittleness of the foam side surface was small, and the flame retardancy was also good.

Comparative Example 1
When the flame retardant concentration in the composition for hard isocyanurate foam was less than 5%, the flame retardancy decreased.

Comparative Examples 2-3
When the equivalent ratio of the organic polyisocyanate (A) to the polyglycidyl ester compound (B) [isocyanate group in (A) / glycidyl group in (B)] is less than 5 or more than 15, flame retardancy decreases. .

Comparative Example 4
Although the evaluation similar to the comparative example 1 was performed using glycidyl ether instead of the polyglycidyl ester compound (B), the flame retardance was further lowered.

Comparative Example 5
The same evaluation as in Comparative Example 1 was performed using a nurate catalyst instead of the tertiary amine catalyst (C), but the flame retardancy was further reduced.

Claims (6)

  A composition for a rigid isocyanurate foam comprising an organic polyisocyanate (A), a polyglycidyl ester compound (B), a catalyst (C), a foaming agent (D), a foam stabilizer (E), and a flame retardant (F). The equivalent ratio of the organic polyisocyanate (A) to the polyglycidyl ester compound (B) [isocyanate group in (A) / glycidyl group in (B)] is 5 to 15, and the catalyst (C) is tertiary. A composition for rigid isocyanurate foam, which is an amine catalyst, the flame retardant (F) is in a liquid state at room temperature, and the flame retardant (F) is contained in an amount of 5 to 20% by weight in the total formulation.   The composition for rigid isocyanurate foam according to claim 1, wherein the polyglycidyl ester compound (B) is a diglycidyl ester compound.   3. The rigid isocyanurate foam according to claim 1, wherein the polyglycidyl ester compound (B) is a diglycidyl orthophthalate and the flame retardant (F) is a normal temperature liquid phosphate ester compound. Composition.   A rigid isocyanurate foam obtained by mixing and foaming the composition for rigid isocyanurate foam according to any one of claims 1 to 3.   Rigid isocyanate which mixes and foams organic polyisocyanate (A) and polyglycidyl compound (B), catalyst (C), foaming agent (D), foam stabilizer (E), and flame retardant (F). A method for producing a nurate foam, wherein the equivalent ratio of the organic polyisocyanate (A) to the polyglycidyl compound (B) [isocyanate group in (A) / glycidyl group in (B)] is 5 to 15, Production of rigid isocyanurate foam characterized in that (C) is a tertiary amine catalyst, the flame retardant (F) is liquid at room temperature, and the flame retardant (F) is contained in an amount of 5 to 20% by weight in the total formulation. Method.   6. The method for producing a hard isocyanurate foam according to claim 5, wherein the molding temperature is room temperature.