KR20010032761A - Low density CO2-blown polyurethane foams and a process of preparing same - Google Patents

Abstract

The present invention relates to a process for the preparation of low density CO ₂ -blown foams having a high independent bubble content. The foams produced by the process of the invention are useful for space-injection applications such as, for example, garage doors, doors, stand-up coolers, portable coolers, refrigerators and water warmers. Using the methods described herein, foam leakage from the mold during the Poor-in-Place operation is reduced, thus reducing the waste and costs associated with the production of foam-filled products made with the Poor-In-Place process. .

Description

Low density CO2-blown polyurethane foams and a process of preparing same

The present invention relates to CO ₂ -blown polyurethane foams. In particular, the present invention relates to low density CO ₂ -blown polyurethane foams and processes for their preparation.

Polyurethane and polyisocyanurate foams (hereinafter referred to as foams) can be used for a variety of applications. As used herein, the term "foam" is understood to include polyurethane-modified polyisocyanurate foams and polyisocyanurate foams. Rigid polyurethane foams can provide a support, for example, in applications that require a rigid support. Such applications include building materials for roofs, facades, building panels, pipe insulation and conduit insulation; Flotation; Floral and marine foams; And lightweight structural members for marine, aviation and other industries. Rigid foams can be prepared by a variety of methods including block-foaming, double-band thinning, discontinuous panels, and pour-in-place (PIP). Double-band thinning, discontinuous panels and the Poor-in-Place method can each be used to produce rigid foams in a single step.

The Poor-in-Place method is a method in which a polyurethane foam formulation is poured into a mold or casing (hereafter a mold) which is an empty shell, followed by filling the mold with foam to form a foam-filled product. PIP methods and their useful applications are well known in the art of making polyurethane foams. See Reaction Polymers; Gum, W. F., Riese, W., and Ulrich, H., Eds. Hanser: New York 1992; pg. 575]. Products manufactured by the PIP method include, for example, garage doors, stand-alone coolers, portable coolers, refrigerators, doors, and water heaters. The foams described herein include rigid foams, molded foams, and slabstock foams.

When used in a PIP process, polyurethane foam formulations may leak or leak from the mold if not foamed during or immediately after injection. Leakage from the mold results in high costs for the production of foam products due to the loss of product and increased maintenance costs. Current routine leaks are typically reduced by adding low boiling compounds to the foaming system at room temperature to increase the foaming of the foaming system at the initiation of the polyurethane reaction or pre-expansion of the foaming system. However, this practice generally requires modification of conventional apparatus. Pre-expansion as used herein refers to an increase in the volume of the foaming system which is a polyurethane-forming reaction mixture prior to the initiation of the polyurethane reaction.

Typically polyurethane foams use blowing agents such as halogenated alkanes to produce the bubble structure present in polyurethane foams. CO ₂ is available as a blowing agent. CO ₂ is produced by the reaction of isocyanates with water when water is included in the polyurethane blowing agent formulation. The use of water and CO ₂ helps to reduce the amount of halogenated alkanes used in the production of polyurethane foams. This may advantageously reduce the amount of halogenated alkanes released into the atmosphere.

Polyurethane foams can be prepared using exclusively water or a combination of CO ₂ as blowing agents. Such foams (hereinafter referred to as CO ₂ -blown foams) are described, for example, in US Pat. No. 5,013,766. CO ₂ -blown foams are typically high density foams having a total density of at least about 2.3 pcf (lbs per cubic foot). Although CO ₂ -blown foams with low density can be obtained by conventional methods, such foams can have a low independent bubble content. In certain applications where low density polyurethane foams having a high independent bubble content are desired, typical CO ₂ -blown foams may be undesirable.

In the art of making rigid polyurethane foams, it is desirable to produce low density CO ₂ -blown foams having a high independent bubble content. It is also desirable in the art to produce rigid foams to reduce leakage during the PIP process.

In one embodiment, the present invention provides a polyisocyanate composition and a polyol composition, wherein the polyol composition comprises (a) at least one aromatic amine-initiated polyol, (b) at least one alkylene carbonate and (c) water) It relates to a polyurethane foam formulation comprising a.

In another aspect, the present invention provides a polyisocyanate composition and a polyol composition, wherein the polyol composition comprises (a) at least one aromatic amine-initiated polyol, (b) at least one alkylene carbonate and (c) water) It relates to a low density CO ₂ -blown foam prepared from a polyurethane foam formulation.

In another embodiment, the present invention provides a polyurethane-filled product by (i) pouring a polyurethane foam formulation, (ii) filling the mold with foam, and (iii) releasing the foam after curing the foam. A method of making a polyurethane-filled product comprising the step of obtaining a polyurethane foam formulation comprising a polyisocyanate composition and a polyol composition, wherein the polyol composition comprises (a) at least one aromatic amine-initiated polyol , (b) at least one alkylene carbonate and (c) water).

Using the method of the present invention, when producing foams using the PIP process, the problem of leakage from the mold can be reduced. The CO ₂ -blown foams obtained using the process of the invention are low density foams which can have a reduction of 15% to 30% in overall density compared to the foams produced by conventional methods.

In one embodiment, the present invention relates to foam formulations useful for the production of CO ₂ -blown foams. Foam formulations of the present invention include polyisocyanate compositions and polyol compositions. When the polyisocyanate and polyol compositions are combined under suitable reaction conditions, the low density polyurethane foams of the present invention are obtained. The polyol composition of the present invention comprises an isocyanate reactant, alkylene carbonate and water. In addition, any component may be included in one or both components of the foam formulation.

Suitable isocyanate-reactive materials for use in the process of the invention include aromatic amine-initiated polyols (AAP). Suitable AAPs for use in the practice of the present invention can be obtained as commercially available products. For example, Boranol 391 (Voranol 391) (trade name of The Dow Chemical Co.) is a commercially available polyol suitable for the practice of the present invention. Boranol 391 is an aromatic amine initiated polyol prepared from o-toluene diamine, ethylene oxide and propylene oxide.

In general, AAP can be obtained by, for example, reacting an aromatic amine with an alkylene oxide under suitable reaction conditions of temperature, pH and catalyst. For example, a suitable temperature range for preparing the AAP of the present invention can be 100 ° C to 135 ° C. The temperature is preferably in the range of 110 ° C to 130 ° C. More preferably, the temperature is 120 ° C to 130 ° C, most preferably 125 ° C to 130 ° C.

The AAP of the present invention can be obtained at a pH in the range of 7.5 to 12. Preferably, the pH is 8 to 11.5. More preferably, the pH is 8.5-11, most preferably 9-11. A catalyst may be included to obtain the AAP of the present invention. Catalysts suitable for the preparation of the polyols of the present invention include, for example, dimethylcyclohexylamine, dimethylethanolamine, and diethylethanolamine, similar compounds, and mixtures thereof; Hydroxides of Group I and Group II metals, such as sodium hydroxide, calcium hydroxide, barium hydroxide, lithium hydroxide, analogous compounds and mixtures thereof.

AAPs suitable for the method of the present invention may have a molecular weight of 425 to 900. Preferably, the molecular weight of AAP is 520-825. More preferably, the molecular weight of AAP is between 560 and 640. Most preferably, the molecular weight of AAP is between 560 and 590. The hydroxyl number of the AAP of the present invention may range from 250 to 530. Preferably the hydroxyl number is in the range of 325 to 465. More preferably, the hydroxyl number is 350 to 450, most preferably 380 to 430. The average functionality of the AAP of the present invention is preferably less than two. More preferably, the average functionality of the AAP is 3 to 5. Most preferably, the average functionality is 3.2 to 4.1.

Polyols of the invention are prepared from alkylene oxides and aromatic amine initiators. Suitable aromatic amines for preparing the AAPs of the present invention may include di- or poly-functional aromatic amines. Suitable aromatic amines include, for example, isomers of toluene diamine (TDA), including 2,6-TDA and 2,4-TDA; Isomers of methylene diamine (MDA) including, for example, 2,2'-MDA, 2,4'-MDA and 4,4'-MDA; Oligomers of MDA, including, for example, mixtures of isomers having 3 to 6 aromatic rings; Alkyl derivatives of aromatic amines such as 4-methyl-2,6-TDA and isomers of dimethyl-MDA; Halogenated derivatives of TDA such as 3-chloro-2,4-TDA; Analogous compounds and mixtures thereof.

Alkylene oxides suitable for use in the present invention include oxides having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms. For example, suitable alkylene oxides include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, epichlorohydrin, 3-methyl-1,2-butylene oxide , Analogous compounds and mixtures thereof. In the present invention, polymers and copolymers of propylene oxide are preferred.

In the foam formulations of the present invention, AAP is present as the only polyol component in the polyol composition, or optionally other polyols may also be included in the composition. If other polyols are included, they may be present in an amount of from 1 to 50% by weight relative to the total polyols. Preferably from 0 to 10% by weight of other polyols are included.

Water is included in the polyol composition of the present invention in an amount of 1 to 12 parts by weight per 100 parts by weight of APP. Preferably, water is included in an amount of 3 to 9 parts by weight. More preferably, it is included in an amount of 5 to 8, most preferably 6.5 to 7.5 parts by weight.

Alkylene carbonates are included in the foam formulations of the present invention. Alkylene carbonates useful in the practice of the present invention are described by the following formula (I) or (II):

In the above formula,

R ₁ , R ₂ , R ₃ and R ₄ are each independently halogen or combinations thereof, alkyl substituents of formula I,

R ₅ and R ₆ are each independently alkyl substituents of formula (II).

The alkyl substituent of formula (I) or (II) may be an alkyl group having 1 to 8 carbon atoms. Suitable alkyl substituents may be aliphatic, aromatic, cyclic or acyclic, substituted or unsubstituted. Examples of suitable alkyl substituents include methyl, ethyl, n-propyl, iso-propyl, n-butyl, isobutyl, pentyl, hexyl, cyclohexyl, phenyl, hydroxyphenyl, phenylmethyl, methylphenyl, bromophenyl, chloromethyl, Analogous compounds, and mixtures thereof. For example, suitable alkylene carbonates include ethylene carbonate; Propylene carbonate; Butylene carbonate; Styrene carbonate (or 1-phenylethylene carbonate); Isobutylene carbonate; Dimethyl carbonate; Diethyl carbonate; Di-tert-butyl carbonate; Dibenzyl carbonate; Diphenyl carbonate; Phenyl, ethyl carbonate, similar compounds, and mixtures thereof.

Suitable alkylene carbonates for use in the process of the invention are known and can be obtained as commercially available products. The purity of the alkylene carbonates is not believed to be critical to the practice of the present invention. For example, Arconate 1000 from Arco Chemical Co. Propylene carbonate sold commercially) has a minimum purity of 99%, but low purity is not believed to interfere with the performance of the present invention. The alkylene carbonate of the present invention may comprise an amount of 1 to 20 parts by weight per 100 parts by weight of AAP. Preferably, the alkylene oxide comprises alkylene carbonate in an amount of 3 to 15 parts by weight per 100 parts by weight of AAP. More preferably, the alkylene carbonate is included in an amount of 5 to 12 parts by weight per 100 parts by weight of AAP. Most preferably, the alkylene carbonate is included in an amount of 7 to 10 parts by weight per 100 parts by weight of AAP. In the practice of the present invention, alkylene carbonates may be included in polyol compositions or isocyanate compositions. Optionally, alkylene carbonates can be included as part of the polyol and isocyanate compositions. Preferably, the alkylene carbonate is included in the polyol composition.

Any component can be included in the polyol composition of the present invention. For example, the polyol composition may optionally include copolymer polyols, polyester polyols, catalysts, fillers, crosslinkers, surfactants, communicators, mold release agents and flame retardants.

Examples of suitable polyurethane catalysts for preparing the polyurethane foams of the present invention include triethylenediamine; N-methyl morpholine; Dimethylethanolamine; Pentamethyldimethylenetriamine; N-ethyl morpholine; Diethylethanolamine; N-coco morpholine; 1-methyl-4-dimethylaminoethyl piperazine; Tertiary amine catalysts such as bis (N, N-dimethylaminoethyl) ether, analogous compounds and mixtures thereof.

Catalysts suitable for use in the present invention are also described in Saunders and Frisch, Polyurethanes, Chemistry and Technology in High Polymers Vol. XVI, pp. 94-97 (1962), including those that catalyze the formation of isocyanurates. Such catalysts are referred to as trimerization catalysts. Examples of these catalysts include aliphatic and aromatic tertiary amine compounds, organometallic compounds, alkali metal salts of carboxylic acids, phenols and symmetric triazine derivatives. Preferred catalysts are potassium salts of carboxylic acids such as potassium octoate and potassium salts of 2-ethylhexanoic acid and tertiary amines such as 2,4,6-tris (dimethyl aminomethyl) phenol.

The amine catalyst is generally used in amounts of 0.1 to 5, preferably 0.2 to 3 parts by weight per 100 parts by weight of the polyol composition. Also suitable are organometallic catalysts, examples of which include organic lead, organic iron, organic mercury and organic bismuth, preferably organotin compounds. Most preferably, they are organotin compounds such as compounds such as dibutyltin dilaurate, dimethyltin dilaurate, tin octoate, tin chloride (II) and the like. Organometallic compounds are generally used in amounts of 0.05 to 0.2 parts by weight per 100 parts by weight of the polyol composition.

Examples of surfactants that may optionally be included are silicone surfactants, most of which are block copolymers containing at least one polyoxyalkylene fragment and one poly (dimethylsiloxane) fragment. Other surfactants include polyethylene glycol ethers of long chain alcohols, long chain alkyl sulfate esters, alkyl sulfonic acid esters and tertiary amine or alkanolamine salts of alkylaryl sulfonic acids. If used, based on 100 parts by weight of polyol, 0.1 to 3, preferably 0.3 to about 1 part by weight of surfactant is generally suitable. Surfactants made from ethylene oxide and butylene oxide as described in US Patent Application Serial No. 08 / 342,299 issued July 23, 1996 are also available for the practice of the present invention. Examples of crosslinkers are diethanolamine and methylene bis (o-chloroaniline) and similar compounds. The use of communicators, mold release agents, flame retardants, fillers and other additives is known in the art to modify and aid the processing performance of the foams, preferably according to the end use application.

Polyisocyanate compositions include polyisocyanates. All polyisocyanates or mixtures of polyisocyanates known in the art are suitable for carrying out the invention. Useful polyisocyanates are described, for example, in US Pat. No. 4,785,027. Polyisocyanates can be aliphatic or aromatic. Suitable aromatic polyisocyanates for use herein include phenyl diisocyanate; 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; Ditoluene diisocyanate; Naphthalene 1,4-diisocyanate; Combination with 2,4'- or 4,4'-diphenylmethane diisocyanate (MDI); Polymethylene polyphenylene polyisocyanate (polymeric MDI); Analogous compounds, and mixtures thereof. Suitable aliphatic polyisocyanates include 1,6-hexamethylene diisocyanate; Isophorone diisocyanate; 1,4-cyclohexyl diisocyanate; Analogous compounds, and mixtures thereof. Also suitable are prepolymers prepared by reacting a polyol or chain extender with a polyisocyanate.

Polyisocyanates may be used in an amount suitable to prepare polyurethane-forming compositions having an isocyanate index of 90 to 500. Preferably, the isocyanate index is 100 to 130. More preferred isocyanate index is 105 to 115. Most preferably, the isocyanate index is 105 to 110. The isocyanate index is measured by dividing the isocyanate equivalent number by the equivalent number of isocyanate-reactive substances and multiplying the obtained ratio by 100. The polyisocyanate of the present invention may have an average functionality of 2.0 to 3.5. Preferably the average functionality is 2.5 to 3.3. More preferably, the average functionality is 2.6 to 3.2. Most preferably, the average functionality is 2.6 to 3.0.

In another aspect, the invention relates to a method of making a polyurethane-filled product by a PIP process using the foam formulations described herein. In general, in PIP operation, foaming is typically delayed until the reaction starts inside the mold cavity. In the process of the invention, pre-expansion occurs initially when the foam formulation is poured into the mold due to the presence of alkylene carbonate. Alkylene carbonates present in the foam formulations of the present invention generate CO ₂ during storage at controlled temperatures. Initial foaming inhibits the foam from leaking out of the unsealed mold, and subsequent foaming enhances the mold-filling process. In the present invention, the polyurethane-filled product is obtained according to the following steps: the polyisocyanate composition and the polyol composition are mixed at a suitable isocyanate index as described herein, the polyurethane-forming mixture is poured into the mold, The foam mixture fills the mold to give a molded rigid foam and the foam is released after curing the foam to obtain a polyurethane-filled product.

In the process of the invention, the polyol composition comprising alkylene carbonate may be stored at a temperature of 10 ° C to 60 ° C. Preferably, the alkylene carbonate-containing composition is stored at a temperature of 16 ° C. to 32 ° C., more preferably at a temperature of 18 ° C. to 27 ° C., and most preferably at 21 ° C. to 24 ° C.

In another aspect, the present invention relates to low density CO ₂ -blown foams made from the foam formulations described herein. The foams of the invention have properties which correspond to at least foams produced according to conventional methods. The properties of the foams which can be improved using the process of the invention are the overall density of the foams, while at the same time maintaining the dimensional stability of the foams. Overall density is the density of the entire molded rigid foam portion. Foams produced according to the process of the invention may have an overall density of 10 pcf or less. Preferably, the foam of the present invention may have a density of 5.0 pcf, more preferably 3.0 pcf or less. Most preferably, the foams of the present invention have a density of about 2.2 pcf or less.

Another property of the foam that can be improved using the process of the invention is the independent bubble content of the foam. The foams obtained using the process of the invention may have an independent bubble content of at least 80%. Preferably the foam of the invention has an independent bubble content of at least 85%. More preferably, the independent bubble content is at least 90%, most preferably at least 92%. In particular, it is important in the present invention that the foams produced according to the process of the invention can have low density, suitable dimensional stability and high independent bubble content. Suitable dimensional stability for the foams of the invention is, for example, a change of 0 ± 8% by volume. Preferably, the dimensional stability is a 0 ± 6 vol% change, most preferably a 0 ± 4 vol% change.

The foams of the present invention further provide excellent adhesion to various gases such as steel facers as well as plastic liner materials such as, for example, high impact polystyrene and high density polyethylene. At the same time, the foams of the present invention maintain excellent dimensional stability at densities of 1.80 pcf or more under conditions of cold, dry and wet conditions. The foam of the present invention exhibits a finer, more uniform bubble structure than conventionally produced foams. Other properties of the foams resulting from the process of the present invention include low free rise densities of about 1.10 pcf, preferably 0.95 to 1.10 pcf, more preferably 0.95 to 1.07 pcf, most preferably less than 0.95 to 1.05 pcf; Low core foam brittleness of about 3.0% or less, preferably 1.0% to 3.0% or less, more preferably 1.0% to 2.5% or less, most preferably 1.0% to 2.0% or less; And rapid release. Foams prepared according to the process of the present invention can generally be released in less than about 8 minutes. Preferably, the foam of the invention releases in 3 to 8 minutes, more preferably in 3 to 7 minutes. Most preferably, the foam of the present invention releases in 3 to 6.5 minutes. Release time depends on the thickness of the foam obtained and the range described herein is for a foam thickness of about 1.75 inch.

The following examples and comparative examples are intended to illustrate the invention. These and comparative examples are not intended to limit the scope of the claims of the present invention and should not be interpreted in such a manner.

Example 1

A polyol composition is prepared by mixing polyol, propylene carbonate and water with any of the ingredients in the amounts described in Table 1.

Example 2

A polyol composition is prepared by mixing polyol, propylene carbonate and water with any of the ingredients in the amounts described in Table 1.

Example 3-Comparative Example

A polyol composition is prepared by mixing the polyol and water with any of the ingredients in the amounts described in Table 1.

Example 4-Comparative Example

A polyol composition is prepared by mixing the polyol and water with any of the ingredients in the amounts described in Table 1.

Example 5-Comparative Example

A polyol composition is prepared by mixing the polyol and water with any of the ingredients in the amounts described in Table 1.

Example 6-Comparative Example

A polyol composition is prepared by mixing the polyol and water with any of the ingredients in the amounts described in Table 1.

Example 7

The polyol composition of Example 1 was PAPI It is combined with 215 parts of 27 isocyanates and an isocyanate index of 105. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3. Foam physical properties are measured according to the following method:

a. The in-place or overall density is measured by the formula D = W / V, where D is the density of the foam, W is the weight of the foam, and V is the volume of the foam.

b. Core density is measured according to ASTM D-1622.

c. The k-factor is measured according to ASTM C-518.

d. Compressive strength is measured according to ASTM D-1621.

d. Brittleness is measured according to ASTM D-421.

e. Dimensional stability is measured according to ASTM D-2126.

f. Independent bubble content is measured according to ASTM D-2856.

Example 8-Comparative Example

PAPI of the polyol composition of Example 3 173 parts of 27 isocyanates and an isocyanate index of 110 are combined. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3.

Example 9-Comparative Example

The polyol composition of Example 4 was PAPI It mix | blends with 214 parts of 27 isocyanates, and the isocyanate index of 110. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3.

Example 10-Comparative Example

The polyol composition of Example 5 was PAPI 173 parts of 27 isocyanates and an isocyanate index of 110 are combined. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3.

Example 11-Comparative Example

The polyol composition of Example 6 was PAPI It is blended with 214 parts of 27 isocyanates and an isocyanate index of 110. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3.

Example 12

The polyol composition of Example 1 was PAPI It is blended at 84 ° F. with 215 parts of 27 isocyanates and an isocyanate index of 105. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3.

Example 13

PAPI of the polyol composition of Example 3 173 parts of 27 isocyanates and an isocyanate index of 110 are combined. The resulting polyurethane-forming mixture is poured into a mold heated to a temperature of 130 ° F. After 4.5 minutes the foam is removed from the mold. The physical properties of one end of the foam are recorded in Table 2. Foam reactivity profiles are shown in Table 3.

Polyols (pph) Propylene carbonate (pph) Water (pph) Surfactant ⁺ (pph) Cat 1 ^a (pph) Cat 2 ^b (pph) Cat 3 ^c (pph) Pyrrole PCF ^# flame retardant (pph) Example 1 100 8.0 7.5 0.8 0.6 None None 3.0 Example 2 100 8.0 7.5 0.8 0.5 0.6 None None Example 3 ^* 100 None 5.0 2.0 1.8 None 2.5 None Example 4 ^* 100 None 7.5 0.8 1.8 None 2.5 None Example 5 ^* 100 None 5.0 0.8 1.8 None 2.5 None Example 6 ^* 100 None 7.5 2.0 1.8 None 2.5 None

* Not an embodiment of the present invention.

+ Vorasurf 504 (trade name of The Dow Chemical Co.).

a dimethylcyclohexylamine.

b Toyota F94 (Toyocat F94) (trade name of Tosoh Corp.).

c Curatene 52 52) (trade name of The Dow Chemical Co.).

^# Commercially available from Akzo Chemical Co.

Free rising density (pcf) Foam overall density (pcf) Core density (pcf) k-factor Independent bubble (%) Compressive strength (psi) Brittleness (% of weight loss) 28 day dimensional stability (% Volume) -22 ° F / 200 ° F / 158 ° F @ Example 7 0.97 2.00 1.83 0.157 96 35 0.8 -0.3 / -2.6 / -2.4 Example 8 ^* 1.56 2.30 2.26 0.153 95 26 1.9 -0.4 / -2.6 / -2.1 Example 9 ^* ** ** ** ** ** ** ** **

* Not an embodiment of the present invention.

@ 95% relative humidity.

** No data. Unmeasurable properties due to the collapse of foam.

Cream time (seconds) Gel time (seconds) Rise time (seconds) Tack-glass time (seconds) Free rising density (pcf) Example ^# 7 10 40 65 65 1.00 Example ^# 8 ^* 10 43 60 70 1.72 Example ^# 9 ^* 10 - - - - Example ^# 10 ^* 10 - - - - Example ^# 11 ^* 11 - - - - Example 12 4-5 28 35 40 0.97 Example 13 ^* 4-5 28 35 40 1.56

* Not an embodiment of the present invention.

# Hand Pour @ 72 ℉.

-No data. Properties that cannot be measured due to the collapse of the foam.

Claims (20)

(1) polyisocyanate compositions; And (2) (a) at least one aromatic amine-initiated polyol; (b) at least one alkylene carbonate; And (c) A polyurethane foam formulation comprising a polyol composition comprising water. The process of claim 1, wherein the aromatic amine-initiated polyol is an isomer of TDA; A polyurethane foam formulation prepared using an aromatic amine selected from the group consisting of isomers of MDA and oligomers of MDA. The polyurethane foam formulation according to claim 2, wherein the aromatic amine is selected from the group consisting of isomers of TDA and isomers of MDA. The polyurethane foam formulation according to claim 3, wherein the aromatic amine is selected from isomers of TDA. The polyurethane foam formulation according to claim 4, wherein the aromatic amine is o-TDA. The polyurethane foam formulation of claim 1 wherein the alkyl carbonate is selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diphenyl carbonate and diethyl carbonate. 7. The polyurethane formulation of claim 6 wherein the alkylene carbonate is propylene carbonate. A low density CO ₂ -blown polyurethane foam made from the polyurethane foam formulation of claim 1. The low density CO ₂ -blown polyurethane foam according to claim 8, wherein the foam overall density is 5.0 pcf or less. The low density CO ₂ -blown polyurethane foam according to claim 9, wherein the foam overall density is 3.0 pcf or less. The low density CO ₂ -blown polyurethane foam of claim 10, wherein the foam overall density is no greater than 2.2 pcf. The low density CO ₂ -blown polyurethane foam according to claim 8, wherein the foam has an independent bubble content of at least 85%. The low density CO ₂ -blown polyurethane foam according to claim 12, wherein the foam has an independent bubble content of at least 90%. The low density CO ₂ -blown polyurethane foam according to claim 13, wherein the foam has an independent bubble content of at least 92%. (i) pouring the polyurethane foam formulation of claim 1 into a mold; (ii) filling the mold with foam; (iii) curing the foam and then releasing the foam to obtain a polyurethane-filled product. The method of claim 15, wherein the foam is produced by a PIP process, wherein leakage from the mold is reduced compared to a PIP process that does not use the formulation of claim 1. The method of claim 15, wherein the polyol composition is stored at a temperature of 10 ° C. to 60 ° C. before blending with the polyisocyanate composition. A polyurethane-filled product made by the method of claim 15. 19. The polyurethane-filled product of claim 18, wherein the product is a door, a refrigerator, a portable cooler, a stand-in cooler, a garage door or a water heater. The polyurethane-filled product of claim 18, wherein the product is a door.