WO2022051212A1

WO2022051212A1 - Polyurethane compositions, polyurethane foams prepared with same and preparation methods thereof

Info

Publication number: WO2022051212A1
Application number: PCT/US2021/048180
Authority: WO
Inventors: Masayuki Suzuki
Original assignee: Dow Global Technologies Llc
Priority date: 2020-09-01
Filing date: 2021-08-30
Publication date: 2022-03-10

Abstract

A polyurethane composition is provided. The polyurethane composition comprises A) a polyisocyanate compound; and B) a polyol component comprising B1) B1) a natural oil polyol or a natural oil-based polyol; and B2) a natural oil polyol ethoxylate. A polyurethane foam prepared from the polyurethane composition has an improved hydrophobilicty and/or excellent foam properties. A method for preparing the polyurethane foam and a method for improving the hydrophobilicty of the polyurethane foam are also provided.

Description

POLYURETHANE COMPOSITIONS, POLYURETHANE FOAMS PREPARED WITH SAME AND PREPARATION METHODS THEREOF

FIELD OF THE INVENTION

The present disclosure relates to a polyurethane composition, a polyurethane foam, a method for preparing the polyurethane foam and a method for improving the hydrophobicity of a polyurethane foam. The polyurethane foam exhibits an improved hydrophobicity without sacrificing foam properties such as cream time and rise time, or a balance between hydrophobicity and foam properties such as cream time and rise time, or even exhibits both an improved hydrophobicity and excellent foam properties such as cream time and rise time.

BACKGROUND TECHNOLOGY

Polyurethane (PU) spray foam is widely used as an insulation material. Easy of spray application, good insulation properties and fast turnover construction period make polyurethane (PU) spray foam more attractive than conventional insulation materials such as glass wool and XPS/EPS foams. Water blown spray foams, particularly in density ranging from 7 kg/m³ to 40 kg/m³ are getting more and more popular because of better insulation with seamless insulation layer and fast turnover in the wooden house insulation market in Japan and North American countries (the United States and Canada).

Water uptake of spray foams were not often discussed until now because the water repellant sheets are normally applied to the outer side of spray foams or between insulation PU foam and siding wall materials. So theoretically, the water doesn’t come into the PU foam insulation layer. On the other hand, once a wooden house is used for a long time, water leakage often happens because of some reasons, e.g. joint, deterioration of wall and roofing materials, water condensation, etc.

For the above reasons, there is still a need in the polyurethane manufacture industry to develop a polyurethane composition which can provide a polyurethane foam having an improved hydrophobicity without sacrificing foam properties such as cream time and rise time, or a balance between hydrophobicity and foam properties such as cream time and rise time, or even having both an improved hydrophobicity and excellent foam properties such as cream time and rise time. After persistent exploration, the inventors have surprisingly developed a polyurethane composition which can achieve one or more of the above targets.

SUMMARY OF THE INVENTION

The present disclosure provides a novel polyurethane composition, a polyurethane foam prepared from the composition, a method for preparing the polyurethane foam and a method for improving the hydrophobicity of a polyurethane foam.

In a first aspect of the present disclosure, the present disclosure provides a polyurethane composition, comprising

A) a polyisocyanate compound;

B) a polyol component comprising

B1) a natural oil polyol or a natural oil-based polyol; and

B2) a natural oil polyol ethoxylate.

In a second aspect of the present disclosure, the present disclosure provides a polyurethane foam prepared from the polyurethane composition as stated above, wherein the polyurethane foam has a density of about 4 to about 40 kg/m³.

In a third aspect of the present disclosure, the present disclosure provides a method for preparing the polyurethane foam, comprising the steps of: i) reacting A) a polyisocyanate compound with B) a polyol component to form the polyurethane foam; wheren the B) polyol component comprising

B1) a natural oil polyol or a natural oil-based polyol; and

B2) a natural oil polyol ethoxylate.

In a fourth aspect of the present disclosure, the present disclosure provides a method for improving the hydrophobicity of a polyurethane foam, comprising the step of incorporating B1) a natural oil polyol or a natural oil-based polyol and B2) a natural oil polyol ethoxylate into polyols for preparing the polyurethane foam.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Also, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference.

As disclosed herein, "and/or" means "and, or as an alternative". All ranges include endpoints unless otherwise indicated. Unless indicated otherwise, all the percentages and ratios are calculated based on weight, and all the molecular weights are number average molecular weights.

According to an embodiment of the present disclosure, the polyurethane composition is a "two-component", "two-part" or "two-package" composition comprising at least one polyisocyanate compound (A) and a polyol component B). The polyisocyanate compound (A) and the polyol component B) are transported and stored separately, combined shortly or immediately before being applied during the manufacture of the polyurethane product. Once combined, the isocyanate groups in polyisocyanate compound (A) reacts with the isocyanatereactive groups (particularly, hydroxyl group) in polyol component (B) to form polyurethane.

The present disclosure provides a polyurethane composition, comprising the following components:

A) a polyisocyanate compound

The polyisocyanate compound refers to an aliphatic, cycloaliphatic, aromatic or heteroaryl compound having at least two isocyanate groups. In a preferable embodiment, the polyisocyanate compound can be selected from the group consisting of C₄-C₁₂ aliphatic polyisocyanates comprising at least two isocyanate groups, C₆-C₁₅ cycloaliphatic or aromatic polyisocyanates comprising at least two isocyanate groups, C₇-C₁₅ araliphatic polyisocyanates comprising at least two isocyanate groups, oligomers of C₄-C₁₂ aliphatic polyisocyanates comprising at least two isocyanate groups, oligomers of C₆-C₁₅ cycloaliphatic or aromatic polyisocyanates comprising at least two isocyanate groups, oligomers of C₇-C₁₅ araliphatic polyisocyanates comprising at least two isocyanate groups, and any combinations thereof. In another preferable embodiment, suitable polyisocyanate compounds include m-phenylene diisocyanate, 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate (TDI), the various isomers of diphenylmethanediisocyanate (MDI), carbodiimide modified MDI products, hexamethylene- 1 ,6-diisocyanate, tetramethylene- 1,4- diisocyanate, cyclohexane- 1,4-diisocyanate, hexahydrotoluene diisocyanate, hydrogenated MDI, naphthylene- 1,5-diisocyanate, isophorone diisocyanate (IPDI), oligomers of m-phenylene diisocyanate, oligomers of 2,4-toluene diisocyanate and/or 2,6-toluene diisocyanate (TDI), oligomers of the various isomers of diphenylmethanediisocyanate (MDI), oligomers of carbodiimide modified MDI products, oligomers of hexamethylene- 1 ,6-diisocyanate, oligomers of tetramethylene- 1,4-diisocyanate, oligomers of cyclohexane- 1,4-diisocyanate, oligomers of hexahydrotoluene diisocyanate, oligomers of hydrogenated MDI, oligomers of naphthylene- 1,5- diisocyanate, oligomers of isophorone diisocyanate (IPDI), or mixtures thereof. Generally, the amount of the polyisocyanate compound may vary based on the actual requirement of the polyurethane foam and the polyurethane tire. For example, as one illustrative embodiment, the content of the polyisocyanate compound can be from about 20 wt% to about 80 wt%, or from about 30 wt% to about 75 wt%, or from about 40 wt% to about 70 wt%, or from about 50 wt% to about 65 wt%, based on the total weight of the polyurethane composition. The content of the polyisocyanate component can be in the numerical range obtained by combining any two of the following end point values 20 wt%, 23 wt%, 24 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt% and 80 wt%, based on the total weight of the polyurethane composition.

According to a preferable embodiment of the present disclosure, the amount of the polyisocyanate compound is properly selected so that the isocyanate group is present at a stoichiometric molar amount relative to the total molar amount of the hydroxyl groups included in the polyol component, and any additional additives or modifiers. In an embodiment, the polyisocyanate compound (A) of the present disclosure can include one or more polyisocyanate compounds including for example a mixture of diphenylmethane diisocyanate; isomers and homologues of diphenylmethane diisocyanate (e.g., two more isomers such as 2,2’- and 2,4’-isomer); and 4,4 ’-methylene diphenyl diisocyanate (MDI); larger molecular weight oligomers of MDI such as polymeric MDI or crude MDI; and mixtures thereof. The polyisocyanate compound can include, for example, a polymeric MDI, and typically a low viscosity grade MDI for providing the reactive mixture a low initial viscosity at room temperature. For example, the viscosity of the polymeric MDI at 25 °C is from about 50 mPa.s to about 2,000 mPa.s in one embodiment; from about 50 mPa.s to about 400 mPa.s in another embodiment; and from about 100 mPa.s to about 250 mPa.s in still another embodiment. The viscosity of the polyisocyanate compound is measured by the process described in ASTM D445.

In another preferred embodiment, the polyisocyanate compound can include commercially available compounds such as PAPI™ 27 and PAPI™ 135 (both available from the Dow Chemical Company); and mixtures thereof.

In an embodiment, the amount of polyisocyanate compound A) used in the composition of the present invention, for example, when the composition is used in a spray foam application, can be, for example, at a ratio by volume of about 1:5 to about 5:1, preferably about 1:2 to about 2:1, more preferably about 1:1 between the polyisocyanate compound A) and the polyol component B).

In another embodiment, the amount of polyisocyanate compound A) used in the composition of the present invention, for example, when the composition is used in a spray foam application, can be, for example, at a ratio by weight of about 1:5 to about 5:1, preferably about 1:2 to about 2:1, more preferably about 1:1 between the polyisocyanate compound A) and the polyol component B).

B) a polyol component

The B) polyol component of the present disclosure comprises B1) a natural oil polyol or natural oil based polyol; and B2) a natural oil polyol ethoxylate. For example, as one illustrative embodiment, the content of the polyol component can be from about 15 wt% to about 60 wt%, or from about 20 wt% to about 50 wt%, or from about 23 wt% to about 40 wt%, or from about 24 wt% to about 35 wt%, or from about 25 wt% to about 32 wt%, based on the total weight of the polyurethane composition. The content of the polyol component can be in the numerical range obtained by combining any two of the following end point values 15, 20 wt%, 23 wt%, 24 wt%, 25 wt%, 30 wt%, 32 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, and 60 wt%, based on the total weight of the polyurethane composition.

B1) a natural oil polyol or natural oil based polyol

The natural oil polyol can be, for example, castor oil.

Castor oil is a mixture of triglyceride compounds obtained from pressing castor seed. About 85 to about 95% of the side chains in the triglyceride compounds are ricinoleic acid and about 2 to 6% are oleic acid and about 1 to 5% are linoleic acid. Other side chains that are commonly present at levels of about 1 % or less include linolenic acid, stearic acid, palmitic acid, and dihydroxystearic acid.

The natural oil based polyol can be a chemically modified mixture of triglyceride compounds obtained from vegetable oils, like soybean oil. Double bonds in natural oil are chemically converted to polyols to make the compounds containing 2, 3 or more hydroxyl group in one molecule. The natural oil based polyol can be soybean oil-based polyol. The natural oil based polyol can be vegetable oil and glycol transesterification product, vegetable oil epoxide ring opening product, vegetable oil hydroformylation and hydrogenation product such as Dow’s “RENUVA” polyol.

The amount of the natural oil polyol or natural oil based polyol used will in general be between about 5 and about 70 parts by weight per 100 parts by the total weight of the polyol component, preferably about 10 to about 65 parts by weight per 100 parts by the total weight of the polyol component, more preferably about 20 to about 60 parts by weight per 100 parts by the total weight of the polyol component, more preferably, about 30 to about 55 parts by weight per 100 parts by the total weight of the polyol component. The amount of the natural oil polyol or natural oil based polyol used can be in the numerical range obtained by combining any two of the following end point values 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, and 70 parts by weight per 100 parts by the total weight of the polyol component.

B2) a natural oil polyol ethoxylate

The natural oil polyol ethoxylate may have 10-30 EO units in its structure, preferably 15- 25 EO units in its structure, more preferably 18-22 EO units in its structure, still more preferably 20 EO units in its structure.

The natural oil polyol ethoxylate can be castor oil ethoxylate having 10-30 EO units in its structure, preferably 15-25 EO units in its structure, more preferably 18-22 EO units in its structure, still more preferably 20 EO units in its structure.

The amount of B2) a natural oil polyol ethoxylate used will in general be between about 5 and about 60 parts by weight per 100 parts by the total weight of the polyol component, preferably about 10 to about 55 parts by weight per 100 parts by the total weight of the polyol component, more preferably about 15 to about 50 parts by weight per 100 parts by the total weight of the polyol component, more preferably, about 20 to about 45 parts by weight per 100 parts by the total weight of the polyol component. The amount of B2) a natural oil polyol ethoxylate used can be in the numerical range obtained by combining any two of the following end point values 5, 10, 12, 15, 20, 25, 26, 28, 30, 35, 40, 45, 50, 55, and 60 parts by weight per 100 parts by the total weight of the polyol component.

The B) polyol component of the present disclosure may further comprises B3) a polyether polyol component.

B3) a polyether polyol component

In various embodiments, the polyether polyol B3) has a molecular weight of about 100 to about 6,000 g/mol, and preferably from about 500 to about 5,000 g/mol, and more preferably from about 2,000 to about 4,000 g/mol. In various embodiments, the polyether polyol has an average hydroxyl functionality of 1.5 to 3.0, and may have an average hydroxyl functionality in the numerical range obtained by combining any two of the following end point values: 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9 and 3.0. According to a preferable embodiment of the present disclosure, the polyether polyol is selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly(2-methyl-1,3-propane glycol) and any copolymers thereof, such as poly(ethylene oxide-propylene oxide) glycol.

According to a particularly preferable embodiment of the present disclosure, the polyether polyol is select from the group consisting of (i) polytetramethylene glycol having a molecular weight of about 200-5,000 g/mol and a hydroxyl functionality of 1.5-3.0; (ii) polyether polyol based on one or more of ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, and 2,3-butylene oxide, having a molecular weight of about 200 to about 5,000 g/mol and a hydroxyl functionality of 1.5-3.0; and a combination thereof. According to a most preferable embodiment of the present disclosure, the polyether polyol is a polytetramethylene glycol having a molecular weight of about 200 to about 5,000 g/mol and a hydroxyl functionality of 1.5-3.0.

According to an embodiment of the present disclosure, the above polyether polyol component can be prepared by polymerization of one or more linear or cyclic alkylene oxides selected from propylene oxide (PO), ethylene oxide (EO), butylene oxide, tetrahyfrofuran, 2- methyl- 1,3 -propane glycol and mixtures thereof, with proper starter molecules in the presence of a catalyst. Typical starter molecules include compounds having at least 1, preferably from 1.5 to 3.0 hydroxyl groups or having 1 or more primary amine groups in the molecule. Suitable starter molecules having at least 1 and preferably from 1.5 to 3.0 hydroxyl groups in the molecules are for example selected from the group comprising ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butenediol, 1,4-butynediol, 1,5 -pentanediol, neopentyl glycol, 1,4-bis(hydroxymethyl) -cyclohexane, 1,2-bis(hydroxymethyl)cyclohexane, 1,3- bis (hydroxymethyl) -cyclohexane, 2-methylpropane- 1,3-diol, methylpentanediols, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, polybutylene glycols, trimethylolpropane, glycerol, pentaerythritol, castor oil, sugar compounds such as, for example, glucose, sorbitol, mannitol and sucrose, polyhydric phenols, resols, such as oligomeric condensation products of phenol and formaldehyde and Mannich condensates of phenols, formaldehyde and dialkanolamines, and also melamine. By way of starter molecules having 1 or more primary amine groups in the molecules are selected for example from the group consisting of aniline, EDA, TDA, MDA and PMDA, more preferably from the group comprising TDA and PMDA, an most preferably TDA. When TDA is used, all isomers can be used alone or in any desired mixtures. For example, 2,4-TDA, 2,6-TDA, mixtures of 2,4-TDA and 2,6-TDA, 2,3-TDA, 3,4-TDA, mixtures of 3,4-TDA and 2,3- TDA, and also mixtures of all the above isomers can be used. Catalysts for the preparation of the poly ether polyols may include alkaline catalysts, such as potassium hydroxide, for anionic polymerization or Lewis acid catalysts, such as boron trifluoride, for cationic polymerization. Suitable polymerization catalysts may include potassium hydroxide, cesium hydroxide, boron trifluoride, or a double cyanide complex (DMC) catalyst such as zinc hexacyanocobaltate or quaternary phosphazenium compound. In a preferable embodiment of the present disclosure, the poly ether polyol include polyethylene, (methoxy)poly ethylene glycol (MPEG), polyethylene glycol (PEG), polypropylene glycol), polytetramethylene glycol, poly(2-methyl-1,3-propane glycol) or copolymer of ethylene epoxide and propylene epoxide (polyethylene glycol-propylene glycol) with primary hydroxyl ended group or secondary hydroxyl ended group.

In a preferred embodiment, the polyether polyol B3) can include, for example, sucrose initiated polyoxypropylene polyol; glycerine initiated polyoxypropylene polyol; ethylene diamine initiated polyol, and the like; and mixtures thereof.

In another preferred embodiment, the polyether polyol B3) can include commercially available compounds such as VORANOL™ 4701 Polyol, VORANOL™4240, VGRANOL™EP1900, VORANOL™ 360, VORANOL™446, VORANOL™482, VORANOL™490, VORANOL™640, VORANOL™800, VORANOL™391, VORANOL™CP1055, VORANOL™8010G, VORANOL™2070, VORANOL™8595, VORANOL™ 1000LM, VORANOL™2QOOLM, VORANOL™WD2104 (all available from The Dow Chemical Company); and mixtures thereof.

If present, the amount of the polyether polyol used will in general be between about 1 and about 60 parts by weight per 100 parts by the total weight of the polyol component, preferably about 2 to about 50 parts by weight per 100 parts by the total weight of the polyol component, more preferably about 3 to about 40 parts by weight per 100 parts by the total weight of the polyol component, more preferably, about 5 to about 35 parts by weight per 100 parts by the total weight of the polyol component, even more preferably, about 10 to about 30 parts by weight per 100 parts by the total weight of the polyol component. The amount of the polyether polyol used can be in the numerical range obtained by combining any two of the following end point values 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 parts by weight per 100 parts by the total weight of the polyol component.

C) water

The polyurethane composition of the present disclosure may optionally further comprise C) water. The water used in the present disclosure can include, for example, potable water; distilled water; deionized water; or mixtures thereof. And, the amount of water used will in general be between about 0.1 and about 40 part by weight per 100 parts by the total weight of the polyol component, preferably about 1 to about 35 part by weight per 100 parts by the total weight of the polyol component, more preferably about 5 to about 30 part by weight per 100 parts by the total weight of the polyol component. The amount of water used can be in the numerical range obtained by combining any two of the following end point values 0.1, 0.5, 1, 3, 5, 10, 15, 20, 25, 30, 35, and 40 parts by weight per 100 parts by the total weight of the polyol component.

D) Catalysts

The polyurethane composition of the present disclosure may optionally further comprise a catalyst.

The reaction between the polyisocyanate compound and the polyol component may occur in the presence of one or more catalysts that can promote the reaction between the isocyanate group and the hydroxyl group. Without being limited to theory, the catalysts can include, for example, glycine salts; tertiary amines; tertiary phosphines, such as trialkylphosphines and dialkylbenzylphosphines; morpholine derivatives; piperazine derivatives; chelates of various metals, such as those which can be obtained from acetylacetone, benzoylacetone, trifluoroacetyl acetone, ethyl acetoacetate and the like with metals such as Be, Mg, Zn, Cd, Pd, Ti, Zr, Sn, As, Bi, Cr, Mo, Mn, Fe, Co and Ni; acidic metal salts of strong acids such as ferric chloride and stannic chloride; salts of organic acids with variety of metals, such as alkali metals, alkaline earth metals, Al, Sn, Pb, Mn, Co, Ni and Cu; organotin compounds, such as tin(II) salts of organic carboxylic acids, e.g., tin(II) diacetate, tin(II) dioctanoate, tin(II) diethylhexanoate, and tin(II) dilaurate, and dialkyltin(IV) salts of organic carboxylic acids, e.g., dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; bismuth salts of organic carboxylic acids, e.g., bismuth octanoate; organometallic derivatives of trivalent and pentavalent As, Sb and Bi and metal carbonyls of iron and cobalt; or mixtures thereof.

Tertiary amine catalysts include organic compounds that contain at least one tertiary nitrogen atom and are capable of catalyzing the hydroxyl/isocyanate reaction. The tertiary amine, morpholine derivative and piperazine derivative catalysts can include, by way of example and not limitation, N,N'-Dimethylaminoethyl-N- Methylethanolamine (such as Dabco® T), Bis(N,N- dimethyl-3-amino-propyl)amine)triethylenediamine (such as Polycat® 15), tetramethylethylenediamine, pentamethyl- diethylene triamine, bis(2-dimethylaminoethyl)ether, triethylamine, tripropylamine, tributyl-amine, triamylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N-ethylmorpholine, 2-methylpropanediamine, methyltriethylenediamine, 2,4,6-tridimethylamino-methyl)phenol, N,N’,N”-tris(dimethyl aminopropyl) sym-hexahydro triazine, or mixtures thereof.

Tertiary amines either alone or in combination with organo-tin catalyst can be used as catalysts in the manufacture of polyurethane foams.

Tertiary amine catalysts play an important role in the composition of the present invention, not only in the control and balance between the gelling and blowing reactions, but also in the optimization of the foam properties and the curing speed during the foam formation.

The amount of the catalyst used will in general be between about 0.1 and about 30 parts by weight per 100 parts by the total weight of the polyol component, preferably about 1 to about 25 parts by weight per 100 parts by the total weight of the polyol component, more preferably about 5 to about 20 parts by weight per 100 parts by the total weight of the polyol component. The amount of the catalyst used can be in the numerical range obtained by combining any two of the following end point values 0.1, 0.5, 1, 3, 5, 10, 12, 14, 15, 20, 25, and 30 parts by weight per 100 parts by the total weight of the polyol component.

E) surfactants

A surfactant may be optionally present in the polyurethane composition. Silicone surfactants can be used in the polyurethane composition of the present disclosure. As a example, grafted copolymers which consist of a polydimethylsiloxane backbone and poly(ethylene oxide- co-propylene oxide) pendant groups can be used as a surfactant to stabilize the bubbles in flexible polyurethane foam. A non-ionic surfactant can also be used, such as 2-ethylhexyl alcohol ethoxylate, commercially available under the trademark Ecosurf EH-9.

The amount of surfactant used will in general be between about 0.1 and about 40 parts by weight per 100 parts by the total weight of the polyol component, preferably about 1 to about 35 parts by weight per 100 parts by the total weight of the polyol component, more preferably about 3 to about 30 parts by weight per 100 parts by the total weight of the polyol component, even more preferably about 10 to about 20 parts by weight per 100 parts by the total weight of the polyol component. The amount of the surfactant used can be in the numerical range obtained by combining any two of the following end point values 0.1, 0.5, 1, 2, 3, 4, 5, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, and 40 parts by weight per 100 parts by the total weight of the polyol component.

F) flame retardants

The polyurethane composition of the present disclosure may optionally further comprise a flame retardant. The flame retardant can be a phosphate ester, such as tris(l-chloro-2- propyl)phosphate (TCPP) or triethylphosphate. (TEP). Other flame retardants commonly used in polyurethane foam can also be used.

The amount of the flame retardant used will in general be between about 0.1 and about 60 parts by weight per 100 parts by the total weight of the polyol component, preferably about 5 to about 55 parts by weight per 100 parts by the total weight of the polyol component, more preferably about 10 to about 40 parts by weight per 100 parts by the total weight of the polyol component, still more preferably about 12 to about 30 parts by weight per 100 parts by the total weight of the polyol component. The amount of the flame retardant used can be in the numerical range obtained by combining any two of the following end point values 0.1, 0.5, 1, 3, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 parts by weight per 100 parts by the total weight of the polyol component. G) other additives

In various embodiments of the present disclosure, the polyurethane composition comprises one or more additives selected from the group consisting of chain extenders, crosslinkers, blowing agents, foam stabilizers, tackifiers, plasticizers, rheology modifiers, antioxidants, fillers, colorants, pigments, dyes, water scavengers, solvents, diluents, slippery-resistance agents, antistatic agents, antioxidants, internal mold release agents, lubricants, UV stabilizers, plasticizers, fungistatic or bacteriostatic substances, external release agents, internal release agents, and combinations of two or more thereof. External release agents, such as silicone oils, can be used instead of, or in addition to, internal release agents.

A chain extender may be present in the reactants that form the polyurethane foam. A chain extender is a chemical having two isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than about 300, preferably less than about 200 and especially from about 31 to about 125. The isocyanate reactive groups are preferably hydroxyl, primary aliphatic or aromatic amino or secondary aliphatic or aromatic amino groups. Representative chain extenders include ethylene glycol, diethylene glycol, triethylene glycol, 1 ,2- propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, cyclohexane dimethanol, ethylene diamine, phenylene diamine, bis(3-chloro-4-aminophenyl)methane, dimethylthio- toluenediamine and diethyltoluenediamine.

One or more crosslinkers also may be present in the reactants that form the polyurethane foam. For purposes of this invention, "crosslinkers" are materials having three or more isocyanatereactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 300. Crosslinkers preferably contain from 3 to 8, especially from 3 to 4 hydroxyl, primary amine or secondary amine groups per molecule and have an equivalent weight of from about 30 to about 200, especially from about 50 to about 125. Examples of suitable crosslinkers include diethanol amine, monoethanol amine, triethanol amine, mono-, di- or tri(isopropanol) amine, glycerine, trimethylol propane, pentaerythritol, and the like.

Chain extenders and crosslinkers are suitably used in small amounts, as hardness increases as the amount of either of these materials increases. From 0 to about 25 parts by weight of a chain extender is suitably used per 100 parts by weight of the polyol component. A preferred amount is from about 1 to about 15 parts per 100 parts by weight of the polyol component. From 0 to about 10 parts by weight of a crosslinker is suitably used per 100 parts by weight of the polyol component. A preferred amount is from 0 to about 5 parts per 100 parts by weight of the polyol component.

A filler may be present in the polyurethane composition. Fillers are mainly included to reduce cost. Particulate rubbery materials are especially useful fillers. Such a filler may constitute from about 1 to about 50% or more of the weight of the polyurethane composition.

Suitable blowing agents include water, air, nitrogen, argon, carbon dioxide and various hydrocarbons, hydrofluorocarbons and hydrochlorofluorocarbons, preferably, the blowing agent is water. From 0 to about 35 parts by weight of a chain extender is suitably used per 100 parts by weight of the polyol component. A preferred amount is from about 5 to about 30 parts per 100 parts by weight of the polyol component. From about 10 to about 25 parts by weight of a crosslinker is suitably used per 100 parts by weight of the polyol component. A preferred amount is from about 15 to about 20 parts per 100 parts by weight of the polyol component.

The C) water, D) catalyst, E) surfactant, F) flame retardant and G) other additives can be transmitted and stored as independent components and incorporated into the polyurethane composition shortly or immediately before the combination of components (A) and (B). Alternatively, these additives may be contained in either of components (A) and (B) when they are chemically inert to the isocyanate group or the isocyanate-reactive group. In an embodiment, the C) water, D) catalyst, E) surfactant, F) flame retardant and G) other additives are contained in B) the polyol component.

A polyurethane foam can be prepared from the polyurethane composition described herein. According to various embodiments of the present disclosure, the polyurethane foam has a density of about 4 to about 40 kg/m³, such as from about 7 to about 30 kg/m³, from about 10 to about 25 kg/m³, from about 12 to about 20 kg/m³, from about 13 to about 16 kg/m³.

Preferably, the polyurethane foam is a spray foam, more preferably is a water-blown opencell PU spray foam.

Preferably, the polyurethane foam is a water-blown open-cell PU spray foam having a density of about 4 to about 40 kg/m³, such as from about 7 to about 30 kg/m³, from about 10 to about 25 kg/m³, from about 12 to about 20 kg/m³, from about 13 to about 16 kg/m³.

Preferably, the polyurethane foam has a cream time of about 3-7 seconds, and/or a rise time of about 15-25 seconds, and/or a water uptake of about 1-80 kg/m³, more preferably a water uptake of about 5-60 kg/m³, even more preferably a water uptake of about 10-50 kg/m³.

Spraying device such as Graco A30 machine and Air purge gun can be used to spray the spray foam composition of the present disclosure.

The foams are generally produced with an Isocyanate Index, or NCO Index within a range of about 40 to about 100, or about 50 to about 70, or about 55 to about 65, or about 60 to 65. NCO index is the actual amount of polyisocyanate used divided by the theoretically required stoichiometric amount of polyisocyanate required to react with all the active hydrogen in the reaction mixture, multiplied by 100. For purposes of the present disclosure, Isocyanate Index is represented by the equation:

Isocyanate Index = (Eq NCO/Eq of active hydrogen) x 100, wherein Eq NCO is the number of NCO functional groups in the polyisocyanate, and Eq of active hydrogen is the number of equivalent active hydrogen atoms.

The present disclosure also provides a method for preparing the polyurethane foam, comprising the steps of: i) reacting A) a polyisocyanate compound with B) a polyol component to form the polyurethane foam, wheren the B) polyol component comprising

B1) a natural oil polyol or a natural oil-based polyol; and

B2) a natural oil polyol ethoxylate.

If any one or more of B3) a polyether polyol, C) water, D) catalyst, E) surfactant, F) flame retardant and G) other additives are used during the preparation of the polyurethane foam, they can be incorporated into the reaction system together with the B) polyol component comprising B1) a natural oil polyol or a natural oil-based polyol; and B2) a natural oil polyol ethoxylate. EXAMPLES

Some embodiments of the invention will now be described in the following Examples. However, the scope of the present disclosure is not, of course, limited to the formulations set forth in these examples. Rather, the Examples are merely inventive of the disclosure.

The information of the raw materials used in the examples is listed in the following Table 1:

Table 1. Raw materials used in the examples

Dabco® T is (N,N'-Dimethylaminoethyl-N- Methylethanolamine)

Polycat® 15 is (Bis(N,N-dimethyl-3-amino-propyl)amine)

PAPI 27 is polymeric MDI with an NCO content of around 31.5%, a functionality of around 2.7, and a viscosity of around 200 mPa-s

VORANOL 4240 is propylene glycol-initiated diol with around 17% EO capping and around 90% primary hydroxyls

VORANOL CP1055 is glycerine-initiated PO homopolymer triol Table I Polyol premix

Preparation of polyol premix

All the ingredients listed in table I were mixed together thoroughly by a pencil mixer (Model number: DX, available from AS ONE Corporation) in a 140ml glass bottle. After the temperature of the mixture was adjusted in a low temperature oven (15°C) for 2 hours until the polyol premix temperature reached to 15 °C.

The temperature of PAPI27 was also controlled to be 15 °C before use.

Test method

Hand foaming test (DOWM 100531)

The polyol premix was mixed with PAPI 27, polymeric MDI under 3000 RPM for 3 seconds. The mixing ratio was polyol premix 28g I Isocyanate 32g in 1000ml plastic cup. Then the following reactivity was observed visually: cream time, rise time, foam height, and foam cell structure.

The specific requirements for hand foaming test was summarized below. As for spray foam application, the cream time should be fast like 3 to 7 seconds. Otherwise, the spray mixture will be sagging. The rise time is important to be fast like within 15-25 seconds. Delaying rise time would lead irregular foam thickness and often cause delamination. The foam height is relating to the foam density. Too low density results in lower insulation performance and poor mechanical properties. Too high density foam will be higher cost.

Specification

Cream time, sec 3-7

Rise time, sec 15-25

Foam height, mm 270-300

In-house water absorption test (Foam soaking method)

Specimen

50 mm X 50 mm X 50 mm, cube foam Procedures:

1. The cube foam was soaked to the water for 3 min;

2. Paper towel was used to dry the foam surface;

3. The foam weight was measured.

Table II Foam properties

Inventive 1: The polyol premix was transparent. Good reactivity (cream and rise time) was obtained. Water uptake was low. Inventive 2: The polyol premix was transparent. Better reactivity (cream and rise time are shorter than Inventive 1) was obtained. Foam height was also higher than Inventive 1 and 3. This should be a best formulation among all formulations in view of the performance balance. Inventive 3 : The polyol premix was transparent. Good reactivity (cream and rise time are the shortest among all formulations) was obtained. Water uptake was the lowest among all formulations.

Comparative 1: This formulation didn’t include ECO20, but the amount of EH-9 was increased instead. The water uptake was higher than those of inventive examples. The polyol premix was transparent. However, the rise time was too slow and foam height was also lower.

Comparative 2: ECO36 was used instead of ECO20, the water uptake was drastically worsen. In addition, the polyol premix was cloudy. However, the reactivity (cream and rise time) was good. The foam height was also acceptable. Comparative 3: This formulation employed CP1055, a 1000MW triol instead of castor oil. The water uptake was higher than those of inventive examples. However, other performances were all good.

Comparative 4: This formulation didn’t include ECO20, but the amount of EH-9 was increased instead. The water uptake was higher than those of inventive examples. The polyol premix was transparent. However, the rise time was too slow and foam height was also lower.

Claims

What is claimed is:

1. A polyurethane composition, comprising

A) a polyisocyanate compound;

B) a polyol component comprising

B1) a natural oil polyol or a natural oil-based polyol; and

B2) a natural oil polyol ethoxylate.

2. The polyurethane composition according to claim 1, wherein the B) polyol component further comprises B3) a poly ether polol.

3. The polyurethane composition according to claim 1, wherein the polyurethane composition further comprises any one or more of the following components: C) water, D) a catalyst, E) a surfactant, F) a flame retardant and G) other additives.

4. The polyurethane composition according to claim 1, wherein the B2) natural oil polyol ethoxylate is a natural oil polyol ethoxylate having 10-30 EO units in its structure.

5. The polyurethane composition according to claim 1, wherein the B2) a natural oil polyol ethoxylate is a castor oil ethoxylate having 10-30 EO units in its structure.

6. The polyurethane composition according to claim 1, wherein the B2) a natural oil polyol ethoxylate is a castor oil ethoxylate having 15-25 EO units in its structure.

7. The polyurethane composition according to claim 1, wherein the B1) a natural oil polyol or a natural oil-based polyol is a castor oil.

8. The polyurethane composition according to claim 1, wherein the polyisocyanate compound is selected from the group consisting of C₄-C₁₂ aliphatic polyisocyanates comprising at least two isocyanate groups, C₆-C₁₅ cycloaliphatic or aromatic polyisocyanates comprising at least two isocyanate groups, C₇-C₁₅ araliphatic polyisocyanates comprising at least two isocyanate groups, oligomers of C₄-C₁₂ aliphatic polyisocyanates comprising at least two isocyanate groups, oligomers of C₆-C₁₅ cycloaliphatic or aromatic polyisocyanates comprising at least two isocyanate groups, oligomers of C₇-C₁₅ araliphatic polyisocyanates comprising at least two isocyanate groups, and any combinations thereof.

9. The polyurethane composition according to claim 1, wherein the content of the polyol component is from about 15 wt% to about 60 wt% based on the total weight of the polyurethane composition.

10. The polyurethane composition according to claim 1, wherein the content of the polyisocyanate compound is from about 20 wt% to about 80 wt% based on the total weight of the polyurethane composition..

11. A polyurethane foam prepared from the polyurethane composition according to any one of claims 1-10, wherein the polyurethane foam has a density of about 4 to about 40 kg/m³.

12. A method for preparing the polyurethane foam of claim 11, comprising the steps of: i) reacting A) a polyisocyanate compound with B) a polyol component to form the polyurethane foam, wheren the B) polyol component comprising

B1) a natural oil polyol or a natural oil-based polyol; and

B2) a natural oil polyol ethoxylate.

13. A method for improving the hydrophobicity of a polyurethane foam, comprising the step of incorporating B1) a natural oil polyol or a natural oil-based polyol and B2) a natural oil polyol ethoxylate into polyols for preparing the polyurethane foam.

14. The method of claim 13, wherein the B2) natural oil polyol ethoxylate is a natural oil polyol ethoxylate having 10-30 EO units in its structure.

15. The method of claim 13, wherein the B1) a natural oil polyol or a natural oil-based polyol is a castor oil.