MXPA00010770A - Hydrocarbon blown rigid polyurethane foams having improved flammability performance - Google Patents

Abstract

Rigid polyurethane or urethane modified polyisocyanurate foams having improved flame resistance are disclosed. The foams are prepared from a composition containing (a) an isocyanate, (b) an isocyanate reactive composition, (c) a hydrocarbon/water blowing agent and (d) a phosphorus material.

Description

RIGID POLYMERIC FOAMS EXPANDED WITH HYDROCARBONS THAT HAVE RESISTANCE TO FIRE IMPROVED BACKGROUND OF THE INVENTION The present invention relates to rigid closed cell polyurethane foams or urethane-modified polyurethane foam foams having improved fire resistance, and which are expanded with blowing agents composed of hydrocarbons with a small amount of water. The invention includes a process used to produce foams, new compositions useful in said process and foams prepared from the same. Rigid polyurethane foams have many known uses, such as in building materials or thermal insulation. Such foams are known to have excellent fire resistance, an initial and long-term thermal insulation and outstanding structural properties. Rigid polyurethane foams, in a conventional manner, have been prepared by reacting a suitable, appropriate and compositional composition. reactivates the isocyanate in the presence of an appropriate expansion agent. * With respect to the expansion agents, the chlorocarbons (CFC s) such as the tric 1 orof luor orne ta (CFC-) 11) and the di c 1 or odi f 1 uo r orne (CC? 2) have been the most extensively used and have been shown to produce foams having low flammability, good thermal insulation properties and excellent dimensional stability. However, despite these advantages, CFCs have fallen into disuse, as they have been associated with the reduction of ozone in the Earth's atmosphere, as well as presenting a potential global warming potential. Accordingly, the use of CFCs has been severely restricted Hydrochlorides (HCFCs) such as HC1-2 (HCFC-22), l-chloro-1,1-di fl uor oet an ( HCFC-142b), and particularly 1,1-dicor o-1-fluorine ethane (HCFC-141b) have been considered for the time being as a viable solution. However, HCFCs have also shown that they cause a similar reduction in the ozone layer of the terrestrial atmosphere and in agreement its use is also under surveillance. In effect, the extended production of HCFC-141b Ijpsta scheduled to finish in the year 2002. Therefore, there has been a need to develop processes for the formation of rigid polyurethane foams Jf ?. Use expansion agents that have a potential for reducing the ozone layer equal to zero and which still produce foams that have flammability, good insulation properties as expansion agents includes several hydrocarbons such as n-pentane, n -butane ycic 1 open t ano. The use of such materials is well known and is described, for example, in U.S. Patent Nos. 5,096,933, 5,444,101, 5,182,309, 5,367.00? and 5,387,618. Hydrocarbons offer many advantages such as the zero potential for ozone depletion, a very low global warming potential, low cost, and are liquid at room temperature. A disadvantage of hydrocarbons, however, is their inherent flammability. The rigid polyurethane foams used in the construction of buildings are closed cell to trap the expansion agent and take advantage of its low thermal conductivity, that is, the capacity of heat insulation. But the presence of this flammable gas trapped in the cells presents a special challenge in terms of flammability characteristics of closed cell foam. Although the flammability of such foam has been a concern in general, the combustion characteristics of the surface of the foam have been of particular concern. The combustion characteristics of the surface of the materials is determined by test methods such as the American Society of Testing Materials (ASTM) E-84"Standard Test Method for Surface Burning Cha r a c t e r i s s of Building Materials". East, is used to evaluate the propagation of the flame on the surface of the material. Popularly referred to as "tunnel testing", the E84 test exposes a foam specimen 24 feet long by 20 inches wide to a controlled air flow and to a flame adjusted such that it propagates a flame along the length Total of an oak specimen of grade selected in 5.5 minutes. Generally the test is carried out on central or internal foam of chosen thickness, but sometimes it is carried out on products with faces. The propagation of the flame and the density of the smoke are the two parameters measured in the test. The Flame Propagation Index (IPL) takes into account the velocity and total distance of the propagation of a flame f visually. The smoke factor is a time-integrated measurement of the occlusion of a visible beam of light. The performance of the material is classified into categories, for example, a flame propagation index of 0 to 25 corresponds to Class I, from 26 to 75 is Class II, from 76 to 225 is Class III. A smoke limit of 450 is required in each of these classes. ASTM E-84 also has a number of other designations, such as Under riters Laboratories 723, National Fire Prevention Association 255, or International Conference of Building Officials 8- 1. Since polyurethane foam laminates are used in building construction, they must meet the requirements of local building codes regarding flammability. When regulating materials, many of the model building codes (such as those of Building Officials and Code Admi nistrators International Inc. (BOCA), International Conference of Building Officials (ICBO) and Southern Buying Code Congress International Inc. (SBCCI)] and the or insurance evaluation organizations [such as Underwriters Laboratories (UL); Factory Mutual Research Corporation (FMRC)] refers to quality standards developed by organizations that set standard standards, such as ASTM. Generally the codes require that the center of the foam have a Flame Propagation Index of 75 or less and a degree of smoke development of 450 or less, ie that they comply with Class II according to ASTM E-84. Laminated boards based on rigid polyurethane used in building insulation applications have exceeded these requirements and historically have been classified as Class I in the ASTM E-84 flammability test. Thus, the foam expanded by HCFC-141b commonly used on the market or the foam expanded by CFC-11 used before the use of 108 CFC's in 1993 has been Class I. A widely used method to improve the fire resistance of The rigid closed-cell expanded hydrocarbon foams have been adding water to the formulation, which when reacted with isocyanate releases carbon dioxide. This reduces the amount of hydrocarbon trapped in the closed cells of the foam. The addition of water and consequent reduction of the hydrocarbon has a deleterious effect on the properties of foam insulation and its structural properties. The use of water reduces the amount of gas with low thermal conductivity (ie hydrocarbon as opposed to carbon dioxide) in the closed cells of the foam. This, as a key attribute of the rigid closed cell polyurethane foam, is not desirable in terms of its good insulating properties and good structural properties at low densities. Other attempts to improve fire resistance in general and the burning characteristics of the surface in particular of hydrocarbon expanded closed cell rigid foams have focused on the addition of halogenated blowing agents (eg, US Patents). United Nos. 5,384,338; 5,385,952; 5 420,167 and 5,556,894) to the formulation of the foam. Such attempts have had limited success. The known methods for producing foams using hydrocarbons as blowing agents and the reaction systems used in such methods have not been characterized by producing rigid polyurethane foams having good fire resistance, in particular with the grade 'Class I in the test of the ASTM E-84, and commercially attractive thermal and structural properties at sufficiently low densities to make its use possible. In summary, the aj, fire resistance associated with such hydrocarbon expanded foams has generally been lower than those of the foams expanded by CFCs and HCFCs. In agreement, there is still a need for a production process of rigid polyurethane or closed-cell urethane-modified polyisocyanurate foams that use hydrocarbon as a blowing agent with a small amount of water and that provide foams that have good fire resistance, particular with the Class I grade in the ASTM E-84 test. It is an object of the present invention to provide rigid polyurethane or closed cell urethane modified polyisocyanurate foams expanded by hydrocarbons having good thermal and structural insulation properties together with improved fire resistance properties. Another object of the present invention is to provide rigid foams of polyurethane or Closed-ended, urethane-modified, hydrocarbon-expanded epoxies that possess the flammability, insulation, and structural properties prior to low densities (comparable to those of expanded foam with CFC or HCFC) using minimal amounts of halogens. The low levels of halogens improve the acceptance of the foam from the environmental point of view.

Invention It has now been found that rigid polyurethane or closed-cell urethane modified foams can be obtained with excellent characteristics of fire resistance and good thermal and structural properties using the following formulation: 1) a organic polyisocyanate, 2) an expanding agent comprising; (a) a hydrocarbon, (b) water in an amount greater than 0 but less than or equal to 1.0% by weight based on the total weight of the foam-forming reaction mixture; 3) a polyfunctional isocyanate-reactive coition, and 4) a phosphorus cond To produce the desired foams the amount of elemental phosphorus or organophosphorus conds used is such that the amount of phosphorus is from 0.3 to 2% by weight and does not contain more than 1.5% halogen, all based on weight total of the foam-forming reaction mixture. Rigid polyurethane or closed cell urethane modified polyurethane foams prepared with the above coition meet the requirements of Class I, ie they have a flame propagation index less than or equal to 25 and a density of smoke of 450 or less when subjected to the test of the ASTM E-84 standard.

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a process and coition for the production of rigid polyurethane foam or closed cell urethane modified polystyrene which has excellent characteristics of fire resistance and good thermal and structural properties. . These foams are obtained using the following formulation. The coition comprises: 1) an organic or organic polymer, ^ _a ^ .J.a!? afaa6ft ^ w ^ ^ a ^. ^. 2) an expanding agent comprising; (a) a hydrocarbon and, (b) water in an amount greater than 0 but less than or equal to 1.0% by weight based on the total weight of the foam-forming reaction mixture; 3) a polyfunctional isocyanate-reactive coition, and 4) a phosphorus cond. In which the amount of phosphorus used is such that the amount of phosphorus is 0.3 to 2% by weight and does not contain more than 1.4% halogen, all based on the total weight of the foam-forming reaction mixture. Rigid polyurethane or closed-cell urethane-modified polyisocyanurate foams prepared with the above coition meet the requirements of Class I, ie they have a flame propagation index less than or equal to 25 and a smoke density of 450 or less when they are submitted to the ASTM E-test A detailed description of the coents used in this invention is given below in the same order as in the coition specified above. (1) Organic Polyisocyanate: Suitable organic polyisocyanates that can be used in the present invention include any of the known techniques in the art for the preparation of rigid foams of urethane or polyurethane-modified polyisocyanurate. Particularly useful organic polymers include those having functionality equal to or greater than 2.0 such as diphenylmethane diisocyanate (MDI) in the forms of its 2,4'- and 4,4'-isomers. and mixtures thereof, mixtures of diphenylmethane diisocyanate and oligomers thereof (known as "crude" MDI) and polymeric MDI (for example polymethylene polyphenylene polyisocyanates). Polyisocyanates modified with various groups containing ester groups, urea groups, biuret groups, allofanate groups, carbodiimide groups, isocyanuto groups, uretdione groups and urethane groups can also be used in the process of the present invention. Such modified isocyanates and methods for their preparation are known in the art. (2a) Hydrocarbon-type expansion agent: One or more hydrocarbon-type expansion agents can be used which evaporate under the conditions of foaming. The appropriate hydrocarbons include butane, isobutane, isopentane, n-pentane, cyclopentane, 1-pentene, n-hexane, isohexane, 1-hexane, n-heptane, isoheptane, and mixtures thereof. Preferably the hydrocarbon-type blowing agent is isopentane, n-pentane, cyclopentane or mixtures thereof. The hydrocarbon type blowing agent should be used in an amount of approximately 2% to about 20% and preferably from about 4% to about 15% by weight based on the total weight of the reaction system. Other physical expansion agents such as compounds other than hydrocarbons may also be used in the present process in combination with hydrocarbon-type blowing agents. Suitable blowing agents include 1, 1, 1, 3, 3-pentaf luoropropane (HFC-245fa), 1,1,1,2-t et raf luoroethane (HFC-134a), 1, 1-di f 1 or oe t ano (HFC-152a), di f 1 uo r orne (HFC-32), c 1 or odi f 1 uo r orne (HCFC-22), and 2-chloropropane. When used, these blowing agents can be mixed with the isocyanate-reactive component, the isocyanate component and / or added as a separate stream from the reaction system. (2b) Water: Water reacts with isocyanate under foaming conditions to release CO - Water could be used with any of the physical expansion agents specified in 2a. The total amount of water is set at less than 1.0% by weight of the total foam formulation to obtain good thermal and structural performance. Preferred results-are reached when the amount of water is less than 0.35%. The blowing agents are used in an amount sufficient to provide the resulting foam with the desired density which is less than 4.0 lb / ft3, preferably less than 3.5 lb / ft3, and most preferably 2.0 lb. / ft3. (3) Polyfunctional isocyanate-reactive compositions: The isocyanate-reactive compositions useful in the present invention include any of those known to those skilled in the art as useful in the preparation of rigid polyurethane foams. Examples of isocyanate-reactive compositions having a plurality of isocyanate-reactive groups include polyester polyols, polyether polyols, and mixtures thereof having an average hydroxyl number of about 20 to .S? at about 1000 and preferably about 50 to 700 mg KOH / g and hydroxyl functionality of about 2 to about 8, and preferably about 2 to about 6. Other isocyanate-reactive materials that can be used in the present invention include poly iti oé polymers, polyamides, polyester amides, polycarbonates, polyacetals, polyolefins, polysiloxanes and polymer polyols terminated in hydrogen. Suitable aromatic polyester polyols include those prepared by the reaction of a p-1 to c-acid and / or a derivative thereof or of an anhydride with a polyhydric alcohol, wherein at least one of the reactants is aromatic. The polyacrylate acids can be any of the known aliphatic, cyclic, aromatic, and / or heterocyclic polycarboxylic acids and can be substituted (for example, with halogen atoms). ) and / or unsaturated. Examples of suitable polycarboxylic acids and anhydrides include oxalic acid, malonic acid, glutaric acid, pimelic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, italic acid, isophthalic acid, terephthalic acid W; ? T *,; -t «gs». * F .--. T ** & e * r Trimellitic acid, hydrolyzed with triamidemic acid, pyromellitic dianhydride, phthalic acid anhydride, acid anhydride tetrahydric acid, hexahydric acid anhydride co anhydride of endomethylene tet ahi dr oft a 1 i co, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, and fatty acids dimers and trimers, such as those derived from oleic acid which may be incorporated into monomeric fatty acids. The simple esters of polycarboxylic acids such as the dimethyl ester of terephthalic acid, the bis-glycol of terephthalic acid and extracts thereof can also be used. Examples of suitable polyaromatic aromatic acids are phthalic acid, isophthalic acid, terephthalic acid, and trimellitic acid. Suitable aromatic acid derivatives are: dimethyl or diethyl esters of potassium acids such as phthalic acid, isophthalic acid, terephthalic acid, and trimellitic acid. . Examples of suitable aromatic anhydrides are phthalic anhydride, anhydride, tertiary, and anhydride.

While polyester polyols can be prepared from substantially pure reagents such as those above, more complex ingredients can be used with advantages, such as by-product streams, phthalic acid manufacturing residues, phthalic anhydride, terephthalic acid, terephthalate dimethyl, polyethylene terephthalate, and the like. The polyhydric alcohols suitable for the preparation of polyester polyols can be aliphatic, cycloaliphatic, aromatic, and / or heterocyclic. The polyhydric alcohols, optionally, may include substituents which are inert to the reaction, for example, chloro or bromo substituents, and / or may be unsaturated. Appropriate amino alcohols, such as monoethanolamine, diethanolamine and the like may also be used. Examples of suitable polyhydric alcohols include ethylene glycol, propylene glycol, poxyalkylene glycols (such as diethylene glycol, polyethylene glycol, dipropylene glycol, and polypropylene glycol), glycerol, and triethylamine. Examples of suitable aromatic polyhydric alcohols include 1,4-benzene dial, di (2-hydroxyl) i e t e 1 hydroquinone, terephthalate of b i s (hi dr ox i e t i 1 o), and resorcinol. There are many commercially available polyester polyols. Stepanpol® PS-2352, PS-2402, PS-3152 are some such polyols manufactured by Stepan Company. Terate® 2541, 254, 403, and 203 are some of those polyols manufactured by Hoech s t-Ce 1 ane s e Corporation. Terol® 235, 235N and 250 are some of those polyols manufactured by Oxid Inc. Suitable polyether polyols include the reaction products of alkylene oxide, for example, of ethylene oxide and / or propylene oxide with initiators containing to 8 active hydrogen atoms per molecule. Suitable initiators include polyols, for example, diethylene glycol, glycerol, trimethylol propane, t r i e t a nol amine, eg, taerythritol, sorbitol, methyl glucoside, mannitol and sucrose; polyamines, for example, ethylene diamine, toluene diamine, di ami nodi fime and polymethylene polyphenylene polyamines; aminoalcohols, for example, ethanolamine and diethanolamine; and mixtures thereof. Preferred initiators include polyols and polyamines.

Additional useful isocyanate reactive materials include the primary and secondary diamines (Unilink 4200), enamines, cyclic ureas, cyclic carbonates, and polycarboxylic acids. Some of these compounds react with isocyanate with evolution of carbon dioxide and contribute to the expansion of the puma. The isocyanate reactive material is used in an amount of about 15% to about 70% and preferably about 20% to about 60% by weight of the total reaction system. (4) Organo - Fó sf gold compounds: Several organic compounds containing phosphorus can be used. Appropriate compounds include phosphates, phosphites, phosphonates, polyfines, polyfluoroes, polyunsaturates, and ammonium polyphosphate. The appropriate phosphate-type compounds are the following: O P ^ -O-P-O-R2? OR3 Where R1 to R * represent alkyl groups, alkyl substituted with halogen, aryl, aryl substituted with halogen, and C i cl or 1 qu 11 o. Preferred phosphates are those wherein R1 to R represent C1-C12 alkyl groups, C1-C12 alkyl substituted with halogen, phenyl, cresyl, phenyl substituted with halogen, and cycloalkyl Cs-Cio- The most preferred phosphates are those where R a R3 represent C? -C8 alkyl groups, C? -C? Alkyl substituted with halogen and phenyl. The most preferred phosphate compounds are those wherein R to R3 represent C1-C4 alkyl groups, C1-C4 alkyl substituted with halogen and phenyl. Some specific compounds of the most preferred phosphites are, t-butyl phosphate, tris (2-c 1 or op r op 11 o) phosphate (Antiblaze 80 from Albpght &Wilson), diphenyl phosphate t-bu 111 f at 11 or (Phosflex 71B from Akzo Nobel), tpethyl phosphate (Eastman's TEP), tbbutyl phosphate (Phosflex 4 from Akzo Nobel), chloropropyl phosphate bi s (br omop r op 11 o) (Firemaster FM 836 from Great Lakes) . Suitable phosphite compounds are the following: R -O-P-O-R '? OR3 Where R1 to R represent H groups, alkyl, alkyl substituted with halogen, aryl, halo substituted halo, and c i c 1 or 1 qu 11 o. Preferred phosphites are those wherein R1 to R3 represent C1-C12 alkyl groups, C1-C12 alkyl substituted with halogen, phenyl, cresyl, phenyl substituted with halogen, and C5-C10 cycloalkyl. The most preferred phosphites are those where R to R3 represent C?-C8 alkyl groups, Ci-Cß alkyl substituted with halogen and phenyl. The most preferred phosphite compounds are those where R1 to R3 represent C1-C4 alkyl groups, C1-C4 alkyl substituted with halogen and phenyl. Some compounds specific for the most preferred phosphites are tpethyl phosphite (Albpte TEP from Albpght & Wilson), phosphite tr 1 s (2-c 1 or oe 11 lo), and tphenyl phosphite (Albrite TPP). Suitable phosphonate-type compounds are the following O FF R ^ O-P-O-R2 F ORJ Where R to R represent alkyl groups, alkyl substituted with halogen, aryl, aryl substituted with halogen, and cycloalkyl. Preferred phosphonates are those wherein R1 to R3 represent C1-C12 alkyl groups, C1-C12 alkyl substituted with halogen, phenyl, cresyl, phenyl substituted with halogen, and C5-C10 cycloalkyl. The most preferred phosphonates are those in which R1 to R3 represent C C-C8 alkyl, C alquilo ~C alquilo alkyl groups substituted with halogen and phenyl. The most preferred phosphone compounds are those wherein R 1 to R 3 represent C 1 -C 4 alkyl, C 1 -C 4 alkyl groups substituted with halogen and phenyl. Some compounds specific for the most preferred phosphonates are diethyl ethyl phosphonate (Antiblaze 75 or Amgard V490 from Albright &ilson), dimethyl methyl phosphonate (Amgard DMMP), 2-chloroethyl phosphonate bis (2-c lo r oe). ti 1 o). Especially preferred results are obtained when one of these preferred phosphonates is included in the composition. Illustrative examples of the polyphosphate type compounds include Amgard V-6, a chlorinated diphosphate ester of A &W. Illustrative examples of ammonium polyphosphate [(NH (P03) ", - n = approximately 1000) are the Hostaflam AP 422 of Hoechst AG and many products of A & . The compounds of the invention used in the invention may have one or more hydrogen atoms reactive to the isocyanate in hydroxyl groups, amine groups, unclear groups, and mixtures thereof. Suitable compounds include monomeric or oligomeric phosphates, phosphites, and phosphonate polyols. Appropriate isocyanate-reactive phosphate compounds are those prepared by (1) the reaction of polyalkylene oxides with (a) phosphoric acids, (b) partial esters of phosphoric acids; (2) the reaction of aliphatic alcohols with (a) phosphoric acids, (b) partial esters of phosphoric acids; and (3) t r an s s t e r i f i ca t ion of the products of (1) and (2). Preferred compounds include tributoxyethyl phosphate (Phosflex T-BEP from Akzo); one or more oligomeric diol (Hostaflam TP OP 550 from Hoechst AG); ethoxylated phosphate esters (Unithox X-5126 from Petrolite); mono and di esters of phosphoric acid and alcohols (Unithox X-1070 from Petrolite).

Appropriate isocyanate-reactive phosphite compounds are those prepared by (1) the reaction of oxides from po 1 to 1 qui 1 e not with (a) phosphorous acids, (b) partial esters of phosphorous acids; (2) the reaction of aliphatic alcohols with (a) phosphorous acids, (b) partial esters of phosphorous acids; and (3) transesterification of the products of (1) and (2). Appropriate isocyanate-reactive phosphonate compounds are those prepared by (1) the reaction of polyalkylene oxides with phosphonic acids; (2) the reaction of polyols phosphite with alkyl halides; (3) the condensation of dialkyl phosphonates with diethanolamine and formaldehyde; (4) transesterification of the products of (1) and (2) and (3); and (5) by reaction of dialkyl alkyl phosphonate with phosphorus pentoxide and alkylene oxide. Preferred compounds include N, N-bis (2-hydroxy, i, i, i) amyl ether, diethyl phosphonate (Fyrol 6 from Akzo); and the hydroxyl-containing oligomeric phosphonate (Fyrol 51 from Akzo). You can also use elemental phosphorus. The amount of said organo-phosphorus compound used is such that the amount of phosphorus is between 0.3 to 2% by weight and if the compound contains halogen there is no more than 1.4% of halogen, based on the total weight of the reaction mixture foam former The preferred amount of phosphorus is between 0.4 to 1.5% and most preferably 0.5 to 1.0% by weight based on the total weight of the foam-forming reaction mixture. Also, preferably no more than 1.25% and most preferably no more than 1.0% by weight of halogens, based on the total weight of the foam-forming reaction mixture. (5) Additives: One or more other auxiliary or conventional additives may be included in the reaction system in the formulation of rigid polyurethane or urethane-modified polyisocyanurate foams. Such optional additives include (without limitation): agents in tr ecr uz ami ent, stabilizing agents or foam like surfactants, catalysts, opacifiers infrared, compounds reducing cell size, viscosity reducing agents co pa t ibi 1 izes, demolding agents, charges, pigments and antioxidants. The various auxiliary agents and additives, when needed for a particular purpose, are generally added to the isocyanate-reactive composition. Suitable auxiliaries and additives include inorganic agents such as triethanolamine and glycerol; stabilizing agents of foam or surfactants such as siloxane-oxyalkylene copolymers; catalysts such as tertiary amines (for example, dimethylcyclohexylamine, pentamethyl diethylenetriamine, 2,4,6-tris (dimethylaminoethyl) phenol, triethylenediamine); organometallic compounds (for example, potassium octoate, potassium acetate, dibutyltin dilaurate); quaternary ammonium salts (e.g. formate, 2-hydroxypropyl trimethylammonium) and triazines N-substituted (N, N ', S' 'dimethylaminopropyl hexahydrotriazine); viscosity reducers such as propylene carbonate, l-metl-2-pyrroldinone, halogenated hydrocarbons; opaque infrared such as carbon black, titanium dioxide, metallic flake; cell size reducing compounds such as fluorinated compounds and inert and insoluble perfluorinated compounds; reinforcing agents such as glass fibers, ground foam residues; demolding agents such as zinc stearate; antioxidants such as butylated hydroxy toluene; and pigments such as azo- / diazo dyes, and f t a 1 oc i ani n s. The amount of such additives is generally from 0.1 to 20%, preferably from 0.3 to 15% and most preferably from 0.5 to 10% by weight based on 100% of the total formulation of the puma When the process for making rigid foams according to this invention is carried out, the techniques of a weight, prepolymer or semi prepolymer together with conventional mixing methods including mixing impact rigid foam may be produced in sheets, molded, filling cavities, applied by spray foam, foam bubbles or laminates with other material such as paper, metal, plastic, or wooden boards. The various aspects of this invention are illustrated, but not limited, by the following examples. Unless otherwise indicated, all temperatures are expressed in Ceisius degrees and all components of the formulation are expressed in parts by weight.

The emulsions In the examples, the following Terate® 254 ma- terials are used: An aromatic polyester polyol of hydroxyl number 235 mg KOH / g, a Average functionality of approximately 2 and a viscosity of 2500 cps at 25 ° C from Hoechst Celanese Corparation. Pelron® 9540A: potassium octoate diethylene glycol Pelron Corp. Dabco® TMR-2: formate N- (2-h i r dr oxip opi 1) - N - t ime t r i 1 ammonium dipropyleneglycol Air Products. Polycat® 5: Pen t ame t i 1 di e t i 1 in Air Products. Polycat® 8: Dime t i 1 ci c 1 ohe xi 1 ami na of Air Products. Polycat® 41: An amine catalyst from Air Products. Tegostab® B8469: A silicone surfactant from Goldshmídt Corporation. Cyclopentane: Available in the Exxon Chemical Company with a purity greater than 95%. Isopentane: Available in the Phillips Chemical Company with a purity greater than 97%. TCPP: T r i Phosphate (be t a - c 1 or op r op i 1 o) (9.5% of P) available from several companies including Akzo Nobel Chemical Inc.

Antiblaze® 75: E 111 diethyl phthalate (DEEP, 18.7% P) available from Albright & Wilson Americas Inc. under the registered trademark. Great Lakes DE-60F ™ Special: 11 oz / aromatic phosphate oxide available at Great Lakes Chemical Corparation. Rubinate® 1850: A polymeric MDI of high functionality available in ICI Americas. Laminated plates of rigid polyurethane foam were prepared using the formulation shown in Table 1. The laminate plate samples were made in a OMS laminator. The laminator is 24.3 feet (7.4 meters) long and can produce plates up to 39 inches (1 meter) wide and 7.9 inches (20 centimeters) thick. The conveyor can be heated to 158 ° F and the table to 122 ° F. The output is 16-33 pounds per minute. All laminates were made with a thickness of 1.5 inches and 39 inches wide, using a typical black glass cover from GAF Corp. The process conditions for making the laminates are shown in the following Table.

Table: Laminate Conditions Foam center density was measured following ASTM 1622. Closed cell contents were measured following ASTM D2856. The fire resistance was tested on a 1.3 inch foam taken from the center of the laminates using the ASTM E-84 test method. The thermal properties of the foam laminates were measured according to the procedures established in ASTM C 518. The thermal aging was performed at room temperature over the total thickness of the laminate. In the evaluations of thermal properties, the lower the k-factor, the better the insulation efficiency of the foam. The structural behavior of the foam was measured on foams taken from the center of the laminates. The dimensional stability at low temperature was measured after 7 days of exposure to -25 ° C following the "Dimvac method" described in "Techniques to Asses the Various Factors Affecting the Long Term Dimensional Stability of Rigid Poiyurethane Foam" in Proceedings of the Poiyurethane 1995 Conference, page 11, (1995). The dimensional stability of the foam was measured after 14 days of exposure to 158 ° F and 97% RH following ASTM D2126. In the dimensional stability test, the closer to zero is the percentage linear change, the better the dimensional behavior of the foam. The structural properties of the foam are also characterized by compression resistance measurements. Said measurements are made in parallel to the elevation and perpendicular to the elevation (in the machine direction and transverse to the machine) following ASTM D1621 P procedure A. Generally, the higher the compression strength, the better it is the structural behavior of the foam. Foams # 1, # 4 and # 6 represent foams prepared using the formulations according to this invention. All the foams were expanded using hydrocarbons as expansion agents with an additional expansion from the reaction of the water with the isocyanate.

Foams # 1 and # 4, which have a density of 1.8 and 1.7 respectively were classified as Class I in the tests of the ASTM E-84 and had thermal and structural properties as good as the foams # 2, # 3, and # 5 which were classified as Class II in the tests of the ASTM E-84. Similarly, foam # 6, which was essentially expanded with hydrocarbon and very little water, was still classified as Class I in the tests of ASTM E-84 and had thermal properties as good as foams # 2, # 3, and # 5 which were classified as Class II in the tests of the ASTM E-84. For comparison, foams # 2, # 3, and # 5 are not within the scope of this invention and do not meet the requirements of Class I in accordance with ASTM E-8.

Table 1

Claims (8)

1. CLAIMS 1. Reaction system for the production of rigid polyurethane or modified urethane of polyisocyanurate foams comprising, A. an organic polyisocyanate; B. an isocyanate reactive composition containing a plurality of isocyanate reactive groups; C. a blowing agent comprising a hydrocarbon and water wherein the amount of water is less than or equal to 1.0% by weight based on the total weight of the reaction system; D. a phosphorus material containing allogen wherein the amount of material used is such that the amount of phosphorus in the composition is equal to about 0.3% to about 2% by weight based on the total weight of the reaction system and with no more than 1.4% by weight of allogen based on the total weight of the reaction system.
2. 2. Reaction system as claimed in claim 1, wherein the organic polyisocyanate is polyphenylene polymethylene polyisocyanate.
3. 3. Reaction system as claimed in claim 1, wherein the isocyanate reactive composition is selected from the group it consists of polyether polyols, polyester polyols and mixtures thereof having average hydroxyl numbers of from about 100 to about 1000 KOH / g and hydroxyl functionalities from about 2 to about 8.
4. 4. Reaction system as claimed in claim 1, wherein the hydrocarbon in the blowing agent is selected from the group consisting of butane, isobutane, isopentane, n-pentane, cyclopentane, 1-pentane, n-hexane, isohexane, 1 -hexane, n-heptane, isoheptane and mixtures of the same.
5. 5. Reaction system as claimed in claim 1, wherein the amount of water in the blowing agent is less than or equal to 0.35% by weight based on the total weight of the reaction system.
6. 6. A reaction system as claimed in claim 1, wherein the phosphorus material is an organic compound selected from the group consisting of phosphates, phosphites, phosphonates, polyfines, polyfines, and phosphonates. afe _ ". rs-l! fe.¿
7. 7. Process for the production of > Rigid polyurethane or modified ureWine of foams of po 1 i i or c anur a t a, the process comprises reacting; A. an organic polyisocyanate; B. an isocyanate reactive composition containing a plurality of isocyanate reactive groups; C. a blowing agent comprising a hydrocarbon and water wherein the amount of water is less than or equal to 1.0% by weight based on the total weight of the reaction system; D. an allogen-containing phosphorus material wherein the amount of material used is such that the amount of phosphorus in the composition is equal to about 0.3% to about 2% by weight based on the total weight of the reaction system and with no more than 1.4% by weight of allogen based on the total weight of the reaction system.
8. 8. Rigid polyurethane or modified urethane foam of water or oil prepared from the reaction system of claim 1.