Patent Description:
Most aromatic polyester polyols used in the production of polyurethane (PU) foams have low functionally in the range of <NUM>-<NUM>. As the functionality increases to <NUM> so does the viscosity. Typical viscosity of an aromatic polyester polyol with a functionality approaching <NUM> is above <NUM>,<NUM> cps, too high to be used as a sole source of polyol because of the viscosity limitations of PU foam production equipment. Thus, they are combined with high functionally/low viscosity polyether polyols to yield PU foams of commercial value.

Aromatic polyester polyols have been used in polyurethane and polyisocyanurate foams for some time. <CIT> and <CIT> disclose a method for making rigid polyurethane and polyisocyanurate foams which entails reacting an excess of an organic polyisocyanate with an etherified modified aromatic polyol. The etherified modified aromatic polyol is prepared by digesting recycled polyalkylene terephthalte (PET) polymers with a low molecular weight polyol, such as diethylene glycol. The resulting product is then blended with a low molecular weight polyol, such as alpha methyl glucoside. The intermediate product is etherified with propylene oxide and/or ethylene oxide.

<CIT> teaches a method for making liquid terephthalic esters that are useful as polyol extenders in rigid polyurethane foams and as the sole polyol component in polyisocyanurate foams. The terephthalic esters are made to remain in a liquid form by reacting recycled polyethylene terephthalte (PET) with diethylene glycol and one or more oxyalkylene glycols. Ethylene glycol is then stripped from the reaction to yield a mixture of ester which is free of solids upon standing. Due to solubility limit, a maximum of <NUM>% alpha-methyl glucoside may be added to increase the functionality of the resulting product.

<CIT> discloses a method for preparing isocyanurate foam that is similar to the methods disclosed above but this method includes reacting an ethoxylate of an alkylphenol, preferably nonylphenol with the polyethylene terephthalate while it is being digested.

<CIT> discloses a method to produce a high functionality and a high aromatic content at a conventional viscosity by combining ethoxylated methyl glucoside or propoxylated methyl glucoside with a polyethylene terephthalte base polyester. <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and "<NPL>) describe polyester polyols.

None of the above described polyols are capable of being used as the sole polyol in the production of polyurethane foams because they lack sufficiently high functionality. The present invention provides a series of high functional polyester polyols to meet the challenge.

The present invention relates to a new and surprisingly useful class of aromatic polyester polyols suitable for use in the manufacture of polyurethane foams. The present invention further relates to polyol-based compositions prepared using such polyols and a blowing agent. The present invention further relates to polyurethane foams made from such polyol-based compositions, and to methods for preparing such polyurethane foams.

The polyols of this invention have moderate viscosity, very high functionality, and high aromatic content. This unique combination of properties makes them suitable for use as the sole polyol in the production of polyurethane foams. No polyether polyols are present in the polyol composition. With minimum amount of flame retardants, the foam based on this sole aromatic polyester polyol can have E-<NUM> class one fire properties rating. The aromatic polyester polyols of this invention are characterized as having a functionality in the range of <NUM> to <NUM> while having a moderate viscosity ranging from <NUM>,<NUM> -<NUM>,<NUM> cps @ <NUM> C, a hydroxyl number in the range of <NUM>-<NUM> and a percent phenyl content (w/w) in the range of <NUM>% to <NUM>%.

The inventive polyol composition is prepared by the transesterification or esterification of a mixture comprising:.

This invention also provides a composition for preparing PU foam. The typical formulation for a PU foam used in spray applications comprises two components: an A-side, comprising a polyisocyanate and a B-side, comprising a mixture of multiple ingredients including catalyst, surfactant, flame retardant, blowing agent and in major part a polyol component consisting of the high functional, moderate viscosity aromatic polyester polyol of this invention. Typically, the polyol component will be <NUM>-<NUM>% (w/w) of the B side component. The polyol component does not include any contribution from polyethers.

A further aspect of the invention provides a method of applying a polyurethane foam comprising the steps of: providing an A-side component comprising polyisocaynate and a B-side component comprising catalysts, surfactant, flame retardants, blowing agents and in major part a polyol component consisting essentially of the inventive high functional, moderate viscosity aromatic polyester polyol; preparing a surface on which to apply the foam; reacting the A-side and B-side components; and applying the reacting components to a surface. The method of forming a PU foam is advantageously applied to a surface of a roof, a structural wall, an insulated cavity, a storage tank or a process vessel.

The typical prior art formulation for a PU foam used in spray applications is shown in Table <NUM>. This type of application requires two components: an A-side, a polyisocyanate and a B-side, a mixture of multiple ingredients including an aromatic polyester polyol and polyether polyol.

The polyisocyanate A-side component of the formulations of the present invention preferably include those as are known to those of skill in the art, and it is not intended that the A-side component be limited to those specifically illustrated herein. For example, the polyisocyanate A-side component of the formulations of the present invention can be advantageously selected from organic polyisocyanates, modified polyisocyanates, isocyanate-based prepolymers, and mixtures thereof. These can include aliphatic and cycloaliphatic isocyanates, but aromatic and especially multifunctional aromatic isocyanates are preferred, and polyphenyl polymethylene polyisocyanates (PMDI) is most preferred. Commercially available PMDI products such as are preferred include Mondur. MR Lite from Bayer Corporation, Rubinate. M from Huntsman Corporation, and the like. PMDI in any of its forms is the most preferred polyisocyanate for use with the present invention.

The requirements for a successful B-side are: (<NUM>) to be visually clear; (<NUM>) to have stable reactivity for a period of time; (<NUM>) to have suitable operation viscosity. Subsequently, the polyurethane (PU) foam is generated from reacting one to one equal volume of B-side and A-side via a high pressure spray equipment with heating and proportional metering capabilities. The spray PU foam must: (<NUM>) be dimensionally stable (<NUM>) have a minimum compressive and tensile strength at nominal two pound density; (<NUM>) must be rated E-<NUM> class I fire property for indoor insulation use. The E-<NUM> class I rating is based on burn results of foam with the flame spread less than or equal to <NUM> and smoke density less than or equal to <NUM>. The biggest challenge to formulators is to have less than or equal to <NUM> smoke density for their PU foams.

The typical prior art balanced formulation of B-side in the Table <NUM> meets all the requirements mentioned above. In detail, the aromatic polyester polyol is Terol <NUM> (manufactured and sold by Oxid LP); polyethers are a combination of JEFFOL R470X and Carpol GSP <NUM> in the weight percent of <NUM> and <NUM> respectively. Flame Retardant <NUM> is Tris(<NUM>-chloro-<NUM>-propyl)phosphate (TCPP) and Flame Retardant <NUM> is PHT4diol, a brominated phthalic anhydrided polyol. The surfactant is a silicon based cell regulator. The co-blowing agents are water and HFC 245FA (<NUM>,<NUM>,<NUM>,<NUM>,<NUM> -pentafluoropropane) with weight percent of <NUM> and <NUM> respectively.

Other blowing agents that can be employed include 365mfc/<NUM> ( a mixture of <NUM>,<NUM>,<NUM>,<NUM>,<NUM>-pentafluorobutane and <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-heptafluoropropane from Solvay), Solstice™-1233zd(E) (trans-<NUM>-chloro-<NUM>,<NUM>,<NUM>-trifluoropropane from Honeywell) and FEA-<NUM> (Hexafluoro-<NUM>-butene from DuPont). The B-side component includes at least one amine catalyst. Commercially available amine catalysts suitable for the present invention include Polycat. <NUM>, Polycat. <NUM>, and Dabco. BL-<NUM> from Air Products. ; Toyocat DM <NUM> from Tosoh Speciality Chemicals USA, Inc. Surfactants such as are commercially available as LK-<NUM> and Dabco. DC-<NUM> from Air Products, and the like can also be used in the present invention. Additionally, flame retardants such as Great Lakes PHT-<NUM> Diol, Akzo-Nobel Fyrol. PCF, ICL Industrial Fyrol <NUM> and the like can be used in the B-side component of the present invention.

Preferably, the Isocyanates:B volume ratio is <NUM>:<NUM>. While not desired, a <NUM>% deviation of this ratio is tolerated.

Polyol Functionality - The average number of reactive group per mole of polyol. It is determined by number average molecular weight of polyol (Mn) divided by equivalent weight of polyol (Eqwt). Mn can be measured by gel permeation chromatography (GPC) or vapor pressure osmometry (VPO). Eqwt can be gained by <NUM>,<NUM> divided by hydroxyl number of polyol. There are many ways to determine the hydroxyl number of polyol, The most popular one is wet method titration.

Aromaticity - Terephthalate stands for one phenyl group with <NUM> hydrogen and <NUM> carbonyl group attachments, the molecular weight is <NUM>. Phenyl stands for a benzene ring with four hydrogen attachments, molecular weight is <NUM>.

Blowing Agent (BA) Solubility - It is a measurement of how many grams of BA in <NUM> grams polyol before reaching the saturation point (the solution turns hazy), expressed as parts per hundred parts of polyol (pphpp).

Compressive strength - It is based on ASTM D <NUM>-<NUM>, a measurement of capacity of foam to withstand axially directed pushing force.

Dimensional Stability - It is based on ASTM D2126-<NUM>, a measurement of foam's ability to retain the precise shape under different temperature and humidity environment. Ranking is given to the aged foam. A is the best and D or below is unacceptable.

Green Strength - A measurement of the ability of foam to withstand the force before complete cure take place. Foam with over all higher functionality would experience less indentation (penetration) than foam with less functionality in same density and reactivities.

SDR - The average smoke density of foam (three burns) from smoke box.

Jeffol R470X, R425X - A Mannich based polyether polyol made by Huntsman.

Caprol GSP <NUM> - A sucrose/glycerin based polyether polyol made by E.

DM <NUM> - Toyocat DM70 is an amine polyurethane catalyst from Tosoh USA.

DC <NUM> - A silicon based cell regulator from Air Products.

BL <NUM> - An amine polyurethane catalyst from Air Products.

PC <NUM> - An amine polyurethane catalyst from Air Products.

Crude Glycerin - collected from biodiesel process, normally contains water, glycerin, free fatty acid, fatty acid methyl ester, soap, ash and transesterifaction catalyst such as potassium hydroxide.

Percent Solids of Polyol- it is determined by Universal Centrifuge (<NUM>,<NUM> rpm for <NUM> minutes) for sampler of <NUM>% solvent and <NUM>% polyol.

Table <NUM> summarizes the advantages and disadvantages of each ingredient in the B-side prior art formulation. Terol <NUM> is aromatic based polyester with hydroxyl number of <NUM>, viscosity of <NUM>,<NUM> cps @ <NUM> C and functionality of <NUM>. Jeffol-470X is an aromatic amine with hydroxyl number of <NUM>, viscosity of <NUM>,<NUM> cps @ <NUM> C and functionality of <NUM>. GSP <NUM> is a sucrose/glycerin initiated propylene oxide based polyether polyol with hydroxyl number of <NUM>, viscosity of <NUM>,<NUM> cps @ <NUM> C and functionality of <NUM>. TCPP is Tris(<NUM>-chloro-<NUM>-propyl)phosphate with viscosity of <NUM> cps @ <NUM> C. It contains <NUM>% phosphate and <NUM>% chlorine. PHT4diol is a brominated polyester polyol (tetrabromophthalic acid ester) with hydroxyl number of <NUM> and viscosity of <NUM>,<NUM> cps @ <NUM> C. It contains <NUM>% bromine. HFC <NUM> is <NUM>,<NUM>,<NUM>,<NUM>,<NUM> -pentafluoropropane.

Terol <NUM> provides the major aromaticity/phenyl for suppressing smoke density and improving char formation of the PU foam but it lacks the functionality as thus no more polyester polyol can be used because the resulting PU foam will not meet the standard of dimensional stability and compressive strength. Polyether polyols provide the functionality to the foam, but they also increase the smoke density due to its propylene oxide content.

In terms of fire properties of the foam, TCPP stops spreading of the flame over the foam by creating a thermal protective char. The chlorine in TCPP and bromine in PHT4 diol undergo thermal degradation and release chloride and bromide radicals that reduce gas phase flame propagation and smoke evolution. Another advantage of TCPP is that it reduces the viscosity of B-side. However, it also acts as a plasticizer and really hurts the dimensional stability as well as mechanical properties of the foam, To meet the E84 class one rating, the prior art foams need both TCPP and PHT4diol (right ratio) in the formulation.

The cost structure of each ingredient in descending order is PHT4diol, TCPP, polyether polyols and aromatic polyester polyols. The formulators would prefer to use more aromatic polyester, less fire retardants, and no polyether polyols. Thus PU foams will have better fire properties and lower cost, but unless the aromatic polyester polyol has high functionality this could not be achieved until the polyols of this invention were developed.

With the new composition of HF polyester polyol of this invention, a new B-side can be formulated as following Table <NUM>:.

Subsequently, the polyurethane foam made from B side as Table <NUM> and polyisocyanate can meet the current requirement of PU spray foam.

Oxid has developed a series of high functional polyester polyols to meet the challenge. A typical high functional (HF) polyester polyol has a hydroxyl number ranging between <NUM>-<NUM>, viscosity of <NUM>,<NUM> -<NUM>,<NUM> cps @ <NUM> C, functionality of greater than <NUM> and percent phenyl content of greater than <NUM> (typically a terephthalate (TERE) content of greater than <NUM>. The Table <NUM> shows a typical transesterification or direct esterification formulation for producing the inventive HF polyester polyol.

In a broad sense, the glycols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol and polypropylene glycol.

Glycerin includes source of petroleum based, plant based, animal based, biodiesel recycled crude and refined grade.

Pentaerythriol (PE) includes source from mono, technical, di-pentaerythriol, tri-pentaerythriol and by-product of manufacturing PE.

Methyl glucoside includes alpha/beta methyl glucoside.

TERE is terephthalate and it comes from polyethylene terephthalate (PET), industrial recycled PET, post-consumer PET, terephthalic acid (TA), industrial recycled TA (Byproduct of Aromatic Carboxylic Acid), phthalic anhydride, iso-phthalic acid and meta- phthalic acid.

Natural oil/fatty acid includes castor oil, palm oil, cotton oil, soybean oil, corn oil, linseed oil, tung oil, tall oil fatty acid, dimer acid and trimer acid. Modified oil includes epoxidized natural oil.

We also know that trimethyolpropane (TMP) and sorbitol can be used to replace glycerin or PE in this application.

The following examples illustrate the present invention, and are not intended to limit the scope of the invention in any way.

Researchers first added <NUM> grams of diethylene glycol, <NUM>,<NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of glycerin, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

Researchers then heat the pot to <NUM> degree C (<NUM> degree F) and hold the pot temperature @ <NUM> degree C (<NUM> degree F) for <NUM> hours. Then, the pot is let to cool down to <NUM> degree C (<NUM> degree F).

When temperature reaches <NUM> degree C (<NUM> degree F), researchers add <NUM> grams of mono PE and <NUM> grams of castor oil. The pot is heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

The polyol produced according to the above trans-esterification method has the following properties:.

Hydroxyl number is raised up to <NUM> by adding some diethylene glycol. The final properties are as follows:.

Researchers first add <NUM> grams of diethylene glycol, <NUM>,<NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of glycerin, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

Researchers then heat the pot to <NUM> degree C (<NUM> degree F) and hold the pot temperature @ <NUM> degree C (<NUM> degree F) for <NUM> hours. Then, researchers will let the pot cool down to <NUM> degree C (<NUM> degree F).

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of mono PE and <NUM> grams of castor oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

Researchers first add <NUM> grams of diethylene glycol, <NUM> grams of triethylene glycol, <NUM>,<NUM> grams of tetraethylene glycol, <NUM> grams of glycerin, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of mono PE. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE that is a mixture of about <NUM>% mono pentaerythritol and <NUM>% di-pentaerythriol and <NUM> grams of castor oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

Researchers first add <NUM> grams of diethylene glycol, <NUM> grams of triethylene glycol, <NUM> grams of C236 (C236 is a product of <NUM> moles propylene oxide added to <NUM> mole of mixtures of ethylene glycol and diethylene glycol in the weight ratio of approximate <NUM> to <NUM>), and <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE and <NUM> grams of castor oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

The polyol produced according to the above method has the following properties:.

Researchers first add <NUM> grams of diethylene glycol, <NUM>,<NUM> grams of tripropylene glycol <NUM> grams of glycerin, and <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

Researchers first add <NUM> grams of diethylene glycol, <NUM> grams of triethylene glycol, <NUM>,<NUM> grams of TPG, <NUM> grams of glycerin, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead polyol receiver and a thermocouple.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

Researchers charge <NUM>,<NUM> gram of crude glycerin into a <NUM> liter pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple. The crude glycerin contains <NUM>% water as supplier suggests. Heat the pot to <NUM> degree C (<NUM> degree F) with <NUM> mmHg vacuum to remove the water and light. Collect condensation @ <NUM> degree C (<NUM> degree F) pot temperature and overhead temperature on top of column @ <NUM> degree C (<NUM> degree F). Total overhead collected is <NUM> grams.

Researchers heat the pot to <NUM> degree C (<NUM> degree F) with <NUM> Hg vacuum. The equilibrium reaches @ <NUM> degree C (<NUM> degree F) with <NUM> Hg vacuum. Overhead temperature is <NUM> degree C. total <NUM>,<NUM> grams of refine clear glycerin is collected with hydroxyl number of <NUM> and percent water of <NUM>. This glycerin is called refine glycerin.

Researchers first add <NUM> grams of diethylene glycol, <NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of refine glycerin produced from experiment <NUM>, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE and <NUM> grams of soybean oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of soybean oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

Researchers first add <NUM> grams of diethylene glycol, <NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of refine glycerin produced from experiment <NUM> and <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of methyl glucoside and <NUM> grams of soybean oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

The hydroxyl number of polyol is raised to <NUM> by post addition of diethylene glycol.

Researchers first add <NUM>,<NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of glycerin, and <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

Researchers then heat the pot to <NUM> degree C (<NUM> degree F) and hold the pot temperature @ <NUM> degree C (<NUM> degree F) for <NUM> hours. Then, researchers will let the pot cool down to <NUM> degree C (<NUM> degree F). When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE and <NUM> grams of epoxidized soybean oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol is distilled from the reaction mixture.

Researchers first add <NUM> grams of diethylene glycol, <NUM>,<NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of glycerin, <NUM>,<NUM> grams of terephthalic acid and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple. Researchers then heat the pot to <NUM> degree C (<NUM> degree F) and hold the pot temperature @ <NUM> degree C (<NUM> degree F) for <NUM> hours. Then, researchers will let the pot cool down to <NUM> degree C (<NUM> degree F). When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE and <NUM> grams of soybean oil. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of water is distilled from the reaction mixture.

The polyol produced according to the above direct esterification method has the following properties:.

Researchers first add <NUM> grams of diethylene glycol, <NUM>,<NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM> grams of refine glycerin produced from experiment <NUM>, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

Researchers first add <NUM> grams of diethylene glycol, <NUM> grams of triethylene glycol, <NUM> grams of tetraethylene glycol, <NUM>,<NUM> grams of polyethylene terephthalate and <NUM> grams of Tyzor TE (a triethanolamine titanate chelate) into a <NUM> neck <NUM> liter glass pot that is equipped with reflux condenser, separation column, overhead receiver and a thermocouple.

When temperature reaches <NUM> degree C (<NUM> degree F), researchers will add <NUM> grams of tech PE, <NUM> grams of soybean oil and <NUM> grams of crude glycerin with <NUM>% water as determined by Karl Fisher Titrator. The pot will be heated up to <NUM> degree C (<NUM> degree F) with vacuum pressure @ <NUM> Hg. The ratio of return to receive is set to three to one. Researchers continue the reactive distillation process until the theoretical amount, <NUM> grams of ethylene glycol and <NUM> grams of water are distilled from the reaction mixture. The polyol was cooled down to about <NUM> to <NUM> degree C (<NUM> to <NUM> degree F) and was filtered through a <NUM> micron filter bag (Filter Specialists, Inc - BPONG25P2pWE).

The main functionality enhancements are glycerin and PE. The examples show that the high functional polyol can be made by using PE or glycerin solely (as example <NUM> and <NUM>). However, with PE and glycerin, polyol seems to be more robust. Castor and epoxidized oil are used for reducing polyol viscosity. They do have some functionality but provide very little of blowing agent solubility improvement. Soybean oil is primarily used for viscosity reduction and for improving blowing agent solubility. Unfortunately, soybean oil does not provide any functionality. Example <NUM> and <NUM> contain no oil of any kind. We get the desirable viscosity by employing high loading of high molecular weight glycols.

Oxid has recently acquired a smoke box, an instrument for detecting smoke density of foam. Although the sampler size of foam is only one inch cubic, the results (SDR) of burning from the box can be correlated to smoke density of real E-<NUM> tunnel test. For example, Oxid is able to get foam samplers that have been tested in the E-<NUM> tunnel. The <NUM>st one is a phenolic foam with smoke density of less than <NUM> (that is determined by E-<NUM>); <NUM>nd one is <NUM> index polyisocyanurate bun stock foam with average smoke density of <NUM> from two reputable E-<NUM> tunnel tests facilities; <NUM>rd one is current commercial two pound wall cavity spray foam as described at Table <NUM>; the <NUM>th one is a roof foam with smoke density of <NUM>. These foams are carefully cut into many one inch cubic foams. The repeat burn on these foams in smoke box is carried out. The following Table <NUM> displays the results.

If charted, the data of Table <NUM> clearly shows that SD <NUM> to <NUM> of E84 vs. SDR of smoke box is almost linear correlation.

Five polyurethane foams and control are prepared in the lab based on the formula of the following Table <NUM>:.

As mentioned above, the control foam meets all the requirements of commercial application. The SDR value of control foam is <NUM>. Based on correlation of Table <NUM>, that is about <NUM> - <NUM> of E-<NUM> tunnel test. (Note: SDR value from Smoke Box is a laboratory test of one cubic inch foam smoke density property. The correlation is just for foam smoke property screening purpose of E84 test. We are not predicting the real E-<NUM> burning smoke density number of actual big scale spray foam due to many other factors are involved. ) PBW1 foam with <NUM>% polyester polyol and <NUM>% flame retardants is <NUM> that is almost equivalent to smoke density of <NUM> of E84. Four percent of PHT4diol and TCPP respectively added to B blend, the SDR value of PBW2 foam increases to <NUM> as expected. When four percent of PHT4diol is replaced by TCPP, the SDR value of PBW3 foam increases to <NUM>. TCPP generates more smoke than PHT4diol does. When <NUM> percent of Carpol GSP <NUM> is added into B blend, the SDR value of PBW4 further increases to <NUM>. When ten percent of Carpol GSP <NUM> is added to the blend, the SDR of PBW5 foam decreases a little bit (perhaps due to more cross linking density). Nonetheless, the polyether does generate smoke. Based on the above results, it seems to me that phenyl (aromaticity) content of B blend is the most important parameter for the smoke density of foam.

In other words, <NUM> percent polyester as solo polyol in the B blend without any polyether and flame retardant is the best method to suppress the smoke density of polyurethane foam. Unfortunately, polyurethane foam is organic material that does need some flame retardants, especially phosphorus to prevent the flame from spreading while burning. Therefore, concerning about foam flame spread and optimal processing viscosity, we recommend seven or ten percent TCPP should be included in the formulation as PBW3 of Table <NUM>. Clearly, PBW3 contains no PHT4diol and its foam has less smoke density (SDR = <NUM>) than the control foam does (SDR= <NUM>).

Again, the <NUM>% polyester polyol as PBW1 of Table <NUM> generates the lowest smoke among five formulations. The more TCPP and PHT4diol in the formulation, the SDR of foam increases.

Replacing HFC 245FA by Solstice™-1233zd(E), the SDR of polyurethane foams based on these two polyols seems to be close. In the case of polyol of example <NUM>, with <NUM> percent TCPP, PBW3 on Table <NUM> is <NUM> and PBW1 on Table <NUM> is <NUM>. In the case of polyol of example <NUM>, with <NUM> percent flame retardants, PBW2 on Table <NUM> is <NUM> and PBW2 on Table <NUM> is <NUM>. Example <NUM> contains PE and glycerin but no castor oil. Its foam smoke property is in line of example <NUM> and example <NUM> polyol.

With <NUM> percent TCPP, the PBW3 on Table <NUM> has viscosity of <NUM> cps @ <NUM> and <NUM> SDR value.

The example <NUM> polyol has the composition as in the Table <NUM>.

Again, we see the dominant effect of phenyl (aromaticity) in B blend on smoke density of foam. Obviously, more castor oil does increase more smoke. Compared to GSP <NUM>, the Jeffol 425X created less smoke.

In Example <NUM>, <NUM> and <NUM>, we are adding C236 as well as Tripropylene glycol to increase the polyol solubility of FEA <NUM>. The polyol as example <NUM> has <NUM> pphpp FEA1100 solubility and the polyol as example <NUM> has <NUM> pphpp FEA1100 solubility. Pphpp stands for parts per hundred parts of polyol.

The foam example of polyol example <NUM> displays on Table <NUM>.

PBW1 on Table <NUM> has an excellent dimensional stability. Smoke density based on SDR value is high but manageable. TPG in the polyol provides plenty of FEA1100 solubility to the B Blend.

Although Example <NUM> and <NUM> polyol contains refined glycerin; it performs the same as if it contains the pure glycerin. It is believed that nature oil would increase smoke density of foam. However, the SDR value of PBW1 on Table <NUM> shows that five percent of soybean oil in the polyol seems to be fine. Again, clearly, containing no PHT4diol, PBW1 foam has lower SDR than the control foam does,.

The example polyol <NUM> contains <NUM> percent glycerin and no PE. The dimensional stability of PBW1 on Table <NUM> is not as good as others but acceptable. The smoke will be on the borderline. Example polyol <NUM> containing about <NUM>% MG seems to be fine with hydroxyl value of <NUM> and viscosity of <NUM>,<NUM> cps @ <NUM> degree C (<NUM> F).

The example <NUM> polyol produced by direct esterification method has same results of example <NUM> that is produced by trans-esterification method does in terms of hydroxyl number, acid number, viscosity and HFC245FA solubility.

Terol <NUM> (supplied by Oxid LP) is a high aromatic content, high functionality polyester polyol. Terol <NUM> has been found useful in spray formulations requiring an E-<NUM> Class I rating using 245fa. The typical properties of Terol <NUM> are as follows:.

Table <NUM> shows the PUR foam formulation and physical properties of foams based on Terol <NUM> (comparative example <NUM> ) and Example polyol <NUM>.

as shown, the polyol ester loading of PBW1 and PBW2 of Table <NUM> are the same. The B side viscosity of PBW1 is <NUM>,<NUM> cps that is much higher than typical handling desirable viscosity. The comparative polyol has higher reaction index than example <NUM> does. However, the foam properties in terms of compressive strength, green strength and dimensional stability, the example <NUM> is much superior to comparative polyol - Terol <NUM>. Without polyether polyol, T925 would have difficulties to provide the much needed physical properties to the foam. The example <NUM> and other HF polyols as sole polyol in the B blend would provide the physical properties to the spray polyurethane foam. Due to higher aromaticity, the Terol <NUM> has less smoke density than polyol as example <NUM> does.

a <NUM>% polyether ( Jeffol 470X and GSP <NUM>) foam is prepared based on the formulation PBW1 on Table <NUM>. As expected, the foam has excellent physical properties including ranking A dimensional stability, minimal indentation of green strength. However, the smoke density is quite high that is almost twice of the foams based on our new polyester.

Based on the polyol formulation excluding example <NUM>, <NUM> and <NUM> as mentioned above, <NUM> (<NUM>,<NUM> pounds) of polyol was produced in pilot plant, labeled as XO <NUM>. The typical polyol properties are on the Table <NUM>.

We sprayed several commercial wall and roof polyurethane foam in Canada using XO <NUM> aromatic polyester polyol. The E-<NUM> tunnel tests were conducted at Exova in Toronto, Canada.

Claim 1:
A polyol composition comprising a high functional, moderate viscosity aromatic polyester polyol, which composition is essentially free of polyether polyol, suitable as the sole polyol in the production of polyurethane foams that have an E-<NUM> tunnel fire test class one rating, said aromatic polyester polyol having a functionality range from <NUM> to <NUM>, a moderate viscosity ranging from <NUM>,<NUM> -<NUM>,<NUM> cps @ <NUM> inclusive, a hydroxyl number in the range of <NUM>-<NUM> inclusive, and percent phenyl content (w/w) in the range of <NUM>% to <NUM>%, wherein said polyol composition is prepared by the transesterification or esterification of a mixture consisting of:
<NUM>-<NUM>% w/w glycols,
<NUM>-<NUM> w/w terephthalate,
<NUM>-<NUM>% w/w glycerin,
<NUM>-<NUM>% w/w pentaerythriol,
<NUM>-<NUM>% w/w methyl glucoside,
<NUM>-<NUM>% w/w sorbitol, and
<NUM>-<NUM>% w/w natural vegetable oil, modified natural vegetable oil or fatty acid derivatives of vegetable oil.