Title of Invention	A POLYETHER POLYESTER POLYOL FOR USE IN POLYURETHANE RIGID FOAM MANUFACTURE
Abstract	An ethylene oxide based polyether polyester polyol for use as base polyol in polyurethane rigid foam manufacture comprising 1-5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 - 1000 g/mole with metal content being < 30 ppm.

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FORM 2 THE PATENTS ACT 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See Section 10; rule 13) TITLE OF THE INVENTION A POLYETHER POLYESTER POLYOL FOR USE IN POLYURETHANE RIGID FOAM MANUFACTURE APPLICANTS HUNTSMAN INTERNATIONAL (INDIA) PVT LTD, HAVING THEIR REGISTERED OFFICE AT, PLOT NO. 1/1, TTC INDL AREA, THANE BELAPUR ROAD, P. O. BOX 12, KOPARKHAIRNE, NAVI MUMBAI 400709, MAHARASHTRA, INDIA, AN INDIAN COMPANY. PREAMBLE TO THE DESCRIPTION The following complete specification particularly describes the nature of the invention and the manner in which it is to be performed. GRANTED 20-6-2006 FIELD OF THE INVENTION: This invention relates to a polyether polyester polyol for use in polyurethane rigid foam manufacture. More particularly this invention relates to an ethylene oxide based polyether polyester polyol comprising 1-5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 - 1000 g/mole, with metal content This invention also relates to a process for the production of the ethylene oxide based polyether polyester polyol. The polyurethane rigid foam products manufactured using the ethylene oxide based polyether polyester polyol of the invention as a base polyol, find application as thermal insulators. PRIOR ART; Non-esterified alkoxylated polyols are reported to be used as base polyols in the manufacture of polyurethane rigid foam. The non-esterified alkoxylated polyols may be prepared from polyols such as water soluble sugars or sugar alcohols like sorbitol or aliphatic amines like ethylene 2 diamine and an alkylene oxide such as ethylene or propylene oxide (US) Patents Nos 4239907 and553334 and PCT Publication Nos WO 96/12759 and WO 98/55523). The non-esterified alkoxylated polyols prepared from ethylene oxide being polar, C4 . 6 straight chain or cyclic hydrocarbon blowing agents which axe used in the manufacture of polyurethane rigid foam show poor solubility [ 4.2). Processing of such highly viscous alkoxylated polyols to manufacture polyurethane rigid foam products is difficult under ordinary conditions and requires use of high pressure equipments. Besides, large quantities of blowing agents will be consumed during polyurethane rigid foam manufacture. Propylene oxide is expensive and less active than ethylene oxide. The process for preparing propylene oxide based polyols is thus expensive and time consuming. Esterified alkoxylated polyols are reported to be prepared by alkoxylation of a polyol like sucrose with alkylene oxide such as ethylene oxide in the presence of water and a base catalyst like sodium hydroxide. The resulting alkoxylate is transesterified with an ester like methyl laurate (Japanese Patent No 7762216). The esterifed alkoxylated polyol is reported to comprise 1-3 ester groups per molecule which may or may not be reactive and has nominal functionality upto 2.98. The esterified alkoxylated 3 polyols are reported to be used as non-ionic surfactant. The above alkoxylation employs large amount (~9%) of water because of which the nominal functionality of the esteiified product is reduced to below 3. This renders the esteiified alkoxykated polyol unsuitable as a base polyol for making dimensionally stable polyurethane rigid foam. The esteiified product is also reported to have high (> 500 ppm) metal content. If high metal containing esteiified alkoxylated polyol is processed as base polyol for polyurethane manufacture, by-products are likely to result which affects the quality/properties of the polyurethane rigid foam. The purity of the esteiified alkoxylated polyol as prepared by the above process is reported to be low (95%). Esteiified alkoxylated polyols prepared by esterification of an alkoxylated polyol such as ethoxylate or propoxylate of sugar or sugar alcohol like sucrose with C2-24fatty aids like oleic acid are described in European Patent No 415635A1. These esterified alkoxylated polyols comprise 6-8 ester groups per molecule which may or may not be reactive and are reported to be used as fat substitutes. Presence of 6 - 8 ester groups per molecule will increase the molecular weight of the esterified alkoxylated polyol which renders them unsuitable for use as base polyol in polyurethane rigid foam manufacture. The process for the preparation of the esterified alkoxylated polyol employs inert solvents like methylene chloride or methanol which are hazardous and expensive. The esterification process itself as reported in the above process takes about 32 hours. The process for the preparation of the esterified 4 alkoxylated polyols is thus unsafe, expensive and time consuming. A low-yield of 86% of the product is reported when prepared by the above route. It has been found out by experimentation that an esterified alkoxylated polyol comprising reactive ester groups, hence hereinafter referred to as polyether polyester polyol (PEPEP), based on ethylene oxide and of the characteristics as defined in the invention finds application in the manufacture of polyurethane rigid foam products as base polyol with distinct advantages. OBJECTS OF INVENTION Accordingly an object of the invention is to provide an ethylene oxide based PEPEP for use as base polyol in polyurethane rigid foam manufacture, which results in dimensionally stable polyurethane rigid foam of low thermal conductivity. Another object of the invention is to provide an ethylene oxide based PEPEP for use as base polyol in polyurethane rigid foam manufacture, which is less expensive. Another object of the invention is to provide an ethylene oxide based PEPEP for use as base polyol in polyurethane rigid foam 5 manufacture, which is less viscous and can be easily processed without Rising high pressure equipments and with less quantities of blowing agent. Another object of the invention is to provide an ethylene oxide based PEPEP for use as base polyol in polyurethane rigid foam manufacture, in which C4 . 6 straight chain or cyclic hydrocarbon/halogenating blowing agent shows high solubility. Another object of the invention is to provide an ethylene oxide based PEPEP for use as base polyol in polyurethane rigid foam manufacture, which eliminates formation of by-products in the manufacture of polyurethane rigid foam. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in polyurethane rigid foam manufacture which results in dimensionally stable polyurethane rigid foam of low thermal conductivity. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in polyurethane rigid foam manufacture, which eliminates use of hazardous solvents and is safe and less expensive. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in 6 polyurethane rigid foam manufacture, which results in high yield and purity of the ethylene oxide based PEPEP. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in polyurethane rigid foam manufacture, which is less time consuming. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in polyurethane rigid foam manufacture which is less viscous and can be easily processed without using high pressure equipments and with less quantities of blowing agent. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in polyurethane rigid foam manufacture in which C4-6 straight chain or cyclic hydrocarbon/halogenating blowing agent showsrhigh solubility. Another object of the invention is to provide a process for the production of an ethylene oxide based PEPEP to be used as base polyol in polyurethane rigid foam manufacture which eliminates formation of by-products in the manufacture of polyurethane rigid foam. 7 DESCRIPTION OF INVENTION: According to the invention there is provided an ethylene oxide based polyether polyester polyol for use as base polyol in polyurethane rigid foam manufacture comprising 1-5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 - 1000 g/mole with metal content being According to the invention there is also provided a process for the production of an ethylene oxide based polyether polyester polyol for use as base polyol in polyurethane rigid foam manufacture comprising 1 - 5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 - 1000 g/mole with metal content being a) ethoxylation of a compound comprising more than one active hydrogen from amino and/or hydroxyl groups with ethylene oxide of 0.5 - 6 kg/cm2 pressure in the mole ratio 0.3 - 3.0, in the presence of a base catalyst in 0.01 -1% by weight of the amino or hydroxyl compound without a solvent in an inert atmosphere at 80 - 160°C; b) insitu transesterification of the resulting ethoxylate of molecular weight 340 - 650 g/mole with a C2-24fatty acid ester comprising atleast one active hydrogen and 1-5 reactive ester groups per molecule in 8 10 - 70% by weight of the ethoxylate under inert atmosphere at 100 - 180°C; followed by c) isolation of the resulting ethylene oxide based polyether polyester polyol by filtration through an inorganic metal oxide or silicate filter bed. Preferably the ethylene oxide based PEPEP comprises 3-5 reactive ester groups, nominal functionality of 3.9 - 5.5 and has molecular weight of 400 - 850 g/mole with metal content being The compound comprising hydroxyl group may be a polyol, sugar and/or sugar alcohol. The polyol may be monoethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropyiene glycol, butane-1,4-diol, butane- 1,3-diol, glycerine, triethylol ethane, trimethylol propane, 3-methyl-l,3,5-pentane trial, 1,2,6-hexane triol and/or diglycerine, pentaerythritol, preferably monoethylene glycol. The sugar or sugar alcohol may be sorbitol, marmitol. glucose, lactose, maltose, sucrose, starch and/or methyl glucoside, preferably sorbitol or sucrose. The compound comprising amino group may be aromatic, aliphatic and/or alkanol amine. The aromatic amine may be aniline, 2,4-toluene diamine, 2,6-toluene diamine or isomeric mixtures thereof, 3,4-toluene diamine, 3,5-toluene diamine, 4,5-toluene diamine, 2,3-toluene 9 diamine, 4,4-diaminodiphenyl methane, 2,4'-diphenyldiamino methane, 2,2'- diphenyldiamino methane or their homologs, m-phenylene diamine, 1,4-cyclohexylene diamine, 2,2,4-trimethylhexamethylene diamine, naphthyl amine or mixtures thereof. Preferably toluene diamine, diamino diphenyl methane or diphenyl diamine or isomers thereof may be used. The aliphatic amine may be ethylene diamine, 1,3-propylene diamine, 1,4-butylene diamine and/or isophorone diamine, preferably ethylenediamine and/or isophorone diamine. The alkanol amine may be monoethanol amine, diethanol amine, triethanol amine, diisopropanol amine and/or triisopropanol amine, preferably mono or diethanol amine. Representative mixtures of amino and hydroxyl compound that may be used for reaction are toluene diamine and sucrose, toluene diamine and sorbitol, toluene diamine isomers and sucrose or toluene diamine isomers and sorbitol. Preferred mixtures may be toluene diamine isomers and sucrose or toluene diamine isomers and sorbitol. The pressure of ethylene oxide may be preferably 0.5 - 4 kg/cm2. The mole ratio of ethylene oxide to active hydrogen from the amino or hydroxyl compound is preferably 0.5 : 3.0. 10 The base catalyst may be inorganic such as alkali or alkaline earth metal salts, oxides, hydroxides, carbonates, alkoxides such as sodium, potassium or cesium oxides, hydroxides, carbonates or alkoxides. Alternatively the base catalyst may be organic such as primary, secondary or tertiary amines such as triethyl amine, butyl amine, ethylene diamine, tetramethyl ethylene diamine, dibutyl amine, di or tri-n-propyl amine, methyldiethyl amine, isobutyl amine, isopropyl amine or amyl or isoamyl amine. Preferably sodium or potassium hydroxide or methoxide is used as a base catalyst. Preferably the catalyst is used in 0.1 - 0.3% by weight of the amino or hydroxy compound. The inert atmosphere during ethoxylation or transesterification may be argon, nitrogen or helium, preferably nitrogen. Preferably the ethoxylation is carried out at 120 - 155°C. The fatty acid ester comprises preferably 3-5 reactive ester groups per molecule. The fatty acid ester may comprise C2-24 preferably C14-18 fatty acid ester such as castor oil or hydrogenated castor oil or glycerides, methyl or ethyl esters of 12-hydroxy stearic acid or ricinoleic acid. Preferably castor oil, hydrogenated castor oil or methyl or ethyl ester of 12-hydroxy stearic acid or ricinoleic acid is used. 11 Preferably the C2-24 fatty acid ester may be in 40 - 60% by weight of the ethoxylate. The transesterification is carried out preferably at 135 - 160°C. Preferably the molecular weight of the ethoxylate is 400 -500 g/mole. The inorganic oxide or silicate filter bed used for isolation of the ethylene oxide based PEPEP may be aluminium or magnesium oxide or silicate, preferably magnesium silicate. Prior to filtration, the reaction mixture may be neutralised with a mineral acid such as hydrochloric acid, sulfuric acid or phosphoric acid or organic acid such as acetic acid, tartaric acid or lactic acid. Polyurethane rigid foam products may be prepared using the ethylene oxide based PEPEP of the invention as base polyol in known manner by blending it with polyoxyalkylenated polyols and aromatic isocyanates such as polymethylene polyphenylene isocyanate in the presence of hydrocarbon blowing agents such as cyclopentane, catalysts such as an amine catalyst and surfactants such as a silicone surfactant. Instead of hydrocarbon blowing agents, halogenating blowing agents such as chlorofluorocarbon may also be used. 12 According to the invention, by controlling the mole ratio of ethylene oxide to the amino or hydroxy compound during ethoxylation as stated in the invention, an ethoxyiate which has a molecular weight of 340 - 65g/mole is obtained. Reaction of such an ethoxyiate with fatty acid ester which comprises atleast one reactive hydrogen and 1-5 reactive ester groups per molecule results in a PEPEP comprising 1-5 reactive ester groups with molecular weight of 400 - 1000 g/mole. Water not being used for the reaction, the nominal functionality of the PEPEP of the invention is achieved between 3.1 - 5.5. Filtration of the PEPEP through a filter bed of metal oxide or silicate ensures low metal content in the PEPEP. Use of ethylene oxide in the preparation of PEPEP of the invention renders the PEPEP less viscous which can be easily processed further for the manufacture of polyurethane rigid foam without using high pressure equipments. Further blowing agents are consumed in the quantities during the manufacture of polyurethane rigid foam Ethylene oxide is also less expensive and more reactive than other alkylene oxides. Therefore the ethylene oxide based PEPEP of the invention is rendered less expensive. The process of the invention for the preparation of the ethylene oxide based PEPEP is less time consuming. It does not use any solvent and is safe and economical. PEPEP produced by the process of the invention is obtained in high yield (~99.5%) and purity (99.5 - 99.9%). Therefore the use of the ethylene oxide based PEPEP prepared by the process of the invention, in the manufacture of polyurethane rigid foam renders the polyurethane rigid foam products less expensive. Due to capping of the ethoxyiate with C2.24 fatty acid ester, hydrocarbon/halogenating blowing agent show high 13 solubility in the ethoxylated PEPEP of the invention than in non-esterified ethoxylated polyol. Low metal content in the ethylene oxide based PEPEP of the invention eliminates formation of by-products in the manufacture of polyurethane rigid foam. The polyurethane rigid foam products to be used as thermal insulators prepared from the PEPEP of the invention are of good quality and show dimesional stability with low thermal conductivity. The following experimental examples are illustrative of the invention but not limitative of the scope thereof. Example 1 14.71 kg of TDA isomers [o-toluene diamine (65 - 95%), 2,5 -toluene diamine (0 - 20%), toluidine 0 - 0.5%)], 0.463 kg of diethanol amine and 0.027 kg of KOH dissolved in 40 ml of water were heated to 90°C with stirring under vacuum in an autoclave to remove water (water content post removal 14 to 35°C to obtain ethylene oxide based PEPEP as a Kght brown liquid with the following characteristics: Molecular weight Nominal functionality Hydroxyl value Viscosity K+ content pH Unreacted free amine Cyclopentane solubility Yield Purity 535 g/mole 3.82 400 + 15mgKOH/gm 29001 300 cps at 31°C Spectroscopy (AAS)] 7.0 Liquid Chromatography (HPLC)] 14 parts by weight (pbw) in 100 pbw ofPEPEP 99.5% 99.5% Example 2 The procedure of Example 1 was followed without removal of the residual ethylene oxide to obtain an ethylene oxide based PEPEP of characteristics as stated in Example 1. Example 3 12.24 kg of powdered sucrose 6.5 kg of TDA isomers [o- toluene diamine (65 - 95%), 2,5 - toluene diamine (0 - 20%), toluidine 0 - 0.5%)], 2.14 kg of monoethylene glycol, 0.864 kg of diethanol amine and 0.034 kg of KOH dissolved in 40 ml of water were heated to 120°C with 15 stirring under vacuum in an autoclave for 0.5 hrs to remove water (water content post removal Molecular weight Nominal functionality Hydroxyl value Viscosity K+ content pH Unreacted free amine Unreacted sucrose Cyclopentane solubility Yield Purity 630 g/mole 4.5 400 ± 15mgKOH/gm 1450±200cpsat3PC 7.0 Nil(ByHPLC) > 25 pbw in 100 pbw of PEPEP 99.7% 99.6% Example 4 310 g of sorbitol (70% solution in water) and 0.4 g of NaOH were heated to 120°C under reduced pressure in an autoclave to remove water 16 rater content post removal Molecular weight Nominal functionality Hydroxyl value Viscosity Na+ content pH Unreacted sucrose Cyclopentane solubility Yield Purity 670 g/mole 5.0 418±15mgKOH/gm 1550±200cpsat30°C 7.0 Nil(ByHPLC) 24 pbw in 100 pbw of PEPEP 99.8% 99.9% Example 5 The procedure of Example 4 was followed except that 0.3 g of K2CO3 was used during transesterification instead of 0.3 g of Na2C03 to 17 obtain an ethylene oxide based PEPEP of the characteristics as stated in Example 4. Example 6 10.25 kg of monoethylene glycol, 11.3 kg of sucrose powder and 0.07 kg of KOH dissolved in 100 ml of water were heated to 120°C with stirring under vacuum in an autoclave for 0.5 hrs to remove water (water content post removal Molecular weight - 440 g/mole Nominal functionality - 3.1 Hydroxyl value - 400 ± 15 mgKCOH/gm Viscosity - 750150 cps at 20°C K+ content - pH - 7.0 Unreacted monoethylene 18 glycol - Nil(ByHPLC) Unreacted castor oil - Cyclopentane solubility - 14 pbw in 100 pbw of PEPEP Yield - 99.5% Purity - 99.8% Example 7 100 g of polymer formed of sucrose, diethylene glycol and propylene oxide (Polyol A, Mfd by TPI, Thailand), 100 g of the ethylene oxide based PEPEP of Example 1, 4.2 g of a silicone surfactant (Tegostab B8404, Mfd by Goldschmidth, Essen, Germany ), 1.0 g of a tertiary amine catalyst (Polycat 8, Mfd by AIR Products, USA), 0.4 g of pentamethyldiethylene triamine catalyst (Polycat 5, Mfd by AIR Products, USA) and 4.8 g of deionised water were blended together. With the mixture was mixed 70 g of chlorofluorocarbon (CFC-11, Mfd by Gujarat Fluorochemicals, India). 163 g of the blend was mixed with 163 g of polymethylene polyphenylene polyisocyanate (~31% free NCO content, functionality ~ 2.7, Suprasec 5005, Mfd by Huntsman Polyurethane, USA) at 22°C for 6 sees. The resulting polyurethane rigid foam was moulded using a mild steel carton box of dimensions 45 x 25 x 9 cms. Example 8 120 g of polymer formed of sucrose, diethylene glycol and propylene oxide (Polyol A), 80 g of the ethylene oxide based PEPEP of Example 2, 4.2 g of a silicone surfactant (Tegostab B8404), 1.5 g of a tertiary amine catalyst (Polycat 8), 0.4 g of an amine catalyst (NIAX - Al, 19 Mfd by WITCO, USA), 0.2 g of pentamethyldiethylene triamine catalyst (Polycat 5) and 4.8 g of deionised water were blended together. With the mixture was mixed 70 g of chlorofluorocarbon (CFC-11). 160 g of the blend was mixed with 166 g of polymethylene polyphenylene polyisocyanate (Suprasec 5005) at 22°C for 6 secs. The resulting polyurethane rigid foam was moulded using a mild steel carton box of dimensions 45 x 25 x 9 cms. Example 9 120 g of polymer formed of sucrose, diethylene glycol and propylene oxide (Poiyol A), 80 g of the ethylene oxide based PEPEP of Example 1, 4g of a silicone surfactant (L-6900, Mfd by Osi, USA), 1.4 g of a tertiary amine catalyst (Polycat 8), 0.1 g of pentamethyldiethylene triamine catalyst (Polycat 5), and 3.6 g of deionised water were blended together. With the mixture was mixed 52 g of dichlorofluoroethane (141b, Mfd by Solve, Germany). 162 g of the blend was mixed with 192 g of polymethylene polyphenylene polyisocyanate (Suprasec 5005) at 22°C for 6 sees. The resulting polyurethane rigid foam was moulded using a mild steel carton box of dimensions 45 x 25 x 9 cms. Example 10 140 g of polymer formed of sucrose, diethylene glycol and propylene oxide (Poiyol A), 60 g of the ethylene oxide based PEPEP of Example 4, 4.6 g of a silicone surfactant (SZ1675A, Mfd by WITCO, USA), 2.8 g of a tertiary amine catalyst (Polycat 8) and 4.4 g of deionised water were blended together. With the mixture was mixed 28 g 20 of cyclopentane. 162 g of the blend was mixed with 192 g of polymethylene polyphenylene polyisocyanate (Suprasec 5005) at 22°C for 6 secs. The resulting polyurethane rigid foam was moulded using a mild steel carton box of dimensions 45 x 25 x 9 cms. The properties of a sample of each of the polyurethane rigid foam products of Examples 7 to 10 of dimensions 100 x 100 x 30 mm were studied and the results were as follows in Table 1 Product of Example 7 Product of Example 8 Product of Example 9 Product of Example 10 Cream time (Sees) 18 18 21 16 Tack free time (Sees) 70 70 71 75 Free rise density (kg/m3) 27 26 29 32 Moulded density (kg/m3) 32 32 35 37 Thermal parameter (mW/mk) 17.5 16.7 18.1 22 Dimensional stability at 30°C with respect to L=-0.2 L=-0.1 LF-0.2 L=-0.2 lengm (L), wtdth (W) W=-0.2 W=-0.1 W=-0.3 W=-.0.2 and thickness (T) T=-0.3 T=-0.2 T=-0.4 T=-0.4 21 The polyurethane rigid loam products of Examples 7 to 10 prepared using the less expensive PEPEP of the invention as base polyol have proved to be less expensive. Since the ethylene oxide based PEPEP of the invention is less viscous, its further processibility while blending with other agents viz polymers, surfactants or catalysts was found to be easy and did not require the use of high pressure equipments. Blowing agents were consumed in less quantities during the manufacture of polyurethane products. In the ethylene oxide based PEPEP of the invention, hydrocarbon/halogenating blowing agents like cyclopentane or chlorofluorocarbon were found to be highly soluble while manufacturing the polyurethane rigid foam products. The polyurethane rigid foam products of Examples 7 to 10 prepared using the ethylene oxide based PEPEP of the invention as base polyol were found to be dimensionally stable with low thermal conductivity with other properties comparable to the standard polyurethane rigid foam products commercially available. 22 We claim: 1) An ethylene oxide based polyether polyester polyol for use as base polyol in polyurethane rigid foam manufacture comprising 1-5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 - 1000 g/mole with metal content being 2) A polyether polyester polyol as claimed in claim 1 comprising 3-5 reactive ester groups, nominal functionality 3.9 - 5.5 and of molecular weight 400 - 850 g/mole with metal content being 3) A process for the production of an ethylene oxide based polyether polyester polyol for use as base polyol in polyurethane rigid foam manufacture comprising 1-5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 -1000 g/mole with metal content being a) ethoxylation of a compound comprising more than one active hydrogen from amino and/or hydroxyl groups with ethylene oxide of 0.5 - 6 kg/cm2 pressure in the mole ratio 0.3 - 3.0, in the presence of a base catalyst in 0.01 - 1% by weight of the amino or hydroxyl compound without a solvent in an inert atmosphere at 80 - 160°C; 23 b) insitu transesterification of the resulting ethoxylate of molecular weight 340 - 650 g/mole with a C2.24fatty acid ester comprising atleast one active hydrogen and 1-5 reactive ester groups per molecule in 10 - 70% by weight of the ethoxylate under inert atmosphere at 100 - 180°C; followed by c) isolation of the resulting ethylene oxide based polyether polyester poiyol by filtration through an inorganic metal oxide or silicate filter bed. 4) A process as claimed in claim 3, wherein the polyether polyester poiyol comprises 3-5 reactive ester groups, nominal functionality 3.9 - 5.5 and is of molecular weight 400 - 850 g/mole with metal content being 5) A process as claimed in claim 3 or 4, wherein the hydroxyl compound is monoethylene glycol, sorbitol and/or sucrose. 6) A process as claimed in any one claims 3 to 5, wherein the amino compound is toluene diamine, diamino diphenyl methane, ethylene diamine, isophorone diamine, mono or diethanol amine and/or isomers thereof. 24 7) A process as claimed in any one of claims 3 to 6, wherein the compound comprising more than one active hydrogen used for ethoxylation is toluene diamine isomers with sucrose or sorbitol. 8) A process as claimed in any one claims 3 to 7, wherein the pressure of ethylene oxide is 0.5 - 4 kg/cm2. 9) A process as claimed in any one claims 3 to 8, wherein the mole ratio of ethylene oxide to the active hydrogen from the hydroxyl or amino compound is 0.5 : 3.0. 10) A process as claimed in any one claims 3 to 9, wherein the base catalyst is sodium or potassium hydroxide or methoxide. 11) A process as claimed in any one claims 3 to 10, wherein the catalyst is in 0.1 - 0.3%. 12) A process as claimed in any one of claims 3 to 11, wherein the inert atmosphere is nitrogen. 13) A process as claimed in any one of claims 3 to 12, wherein the ethoxylation is carried out at 120 - 155°C. 25 14) A process as claimed in any one of claims 3 to 13, wherein the C2.24 fatty acid ester comprises 3 - 5 reactive ester groups per molecule. 15) A process as claimed in any one of claims 3 to 14, wherein the C2.24 fatty acid ester is castor oil, hydrogenated castor oil or methyl or ethyl ester of 12- hydroxy stearic acid or ricinoleic acid. 16) A process as claimed in any one of claims 3 to 15, wherein the C2.24 fatty acid ester is in 40 - 60%. 17) A process as claimed in any one of claims 3 to 16, wherein the transesterification is carried out at 135- 160°C. 18) A process as claimed in any one of claims 3 to 17, wherein the molecular weight of the ethoxylate is 400 - 500 g/mole. 19) A process as claimed in any one of claims 3 to 18, wherein the filter bed used for isolation of the ethylene oxide based polyether polyester polyol is of magnesium silicate. 20) A process for the production of an ethylene oxide based polyether polyester polyol for use as base polyol in polyurethane rigid foam manufacture comprising 1 - 5 reactive ester groups, nominal functionality 3.1 - 5.5 and of molecular weight 400 -1000 g/mole with metal content being Dated this 7th day of November 2000 (MA Jose) of DePenning & DePenning Agent for the Applicants

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1002-mum-2000-claims(granted)-(20-06-2006).doc

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1002-mum-2000-correspondence(20-06-2006).pdf

1002-mum-2000-correspondence(ipo)-(31-10-2006).pdf

1002-mum-2000-form 1(08-11-2000).pdf

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1002-mum-2000-form 19(25-06-2004).pdf

1002-mum-2000-form 2(granted)-(20-06-2006).doc

1002-mum-2000-form 2(granted)-(20-06-2006).pdf

1002-mum-2000-form 26(08-11-2000).pdf

1002-mum-2000-form 26(28-02-2001).pdf

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1002-mum-2000-form 3(20-06-2006).pdf

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1002-mum-2000-form 6(28-02-2001).pdf

1002-mum-2000-power of attorney(20-06-2006).pdf