Polyol for polyurethane production and method to produce such polyol

Abstract

A method for manufacturing a polyester polyol composition comprises the step of providing isohexide, at least a reaction compound and a diol. The reaction compound comprises a dicarboxylic acid or an anhydride of a dicarboxylic acid, or combinations thereof. By chemical reaction between the isohexide, the reaction compound and the diol, a polyester polyol composition is obtained comprising polyester polyol molecules comprising primary hydroxyl groups. The isohexide, the reaction compound and the diol are integrated in the polyester polyol molecules.

Description

[0001] Polyol for polyurethane production and method to produce such polyol

[0002] The invention relates to a polyester polyol composition that can be used in the production of polyurethane, e.g. in the production of rigid polyisocyan urate foams. The invention also relates to methods for the production of the polyester polyol.

[0003] It is known to produce polyurethane, e.g. polyurethane or polyisocyanurate foams, by a chemical reaction between a polyol and a di-isocyanate or a polyisocyanate.

[0004] W02020 / 076529A1 and W02020 / 076539A1 describe recipes for the production of polyurethane foams. The recipes comprise polyol, a polyisocyanate, a blowing agent, surfactants, and a catalyst.

[0005] US2010 / 0240785A1 discloses a foam forming composition comprising at least one diisocyanate component and / or at least one polyisocyanate component; and at least one aromatic polyester polyol component. The aromatic polyester polyol comprises at least one aromatic acid component, at least one hydroxylated component, at least one functionalized natural oil component: and optionally at least one catalyst component. US2010 / 0240785 Al describes methods to produce the aromatic polyester polyol component.

[0006] It is an objective of the invention to provide a polyester polyol that comprises a higher content of biobased raw material, and preferably consists of biobased raw material. It is an objective of the invention to provide a method for the production of a polyester polyol having a higher content of biobased material. It is an objective of embodiments of the invention to provide a polyester polyol that does not comprise aromatic components.

[0007] The first aspect of the invention relates to a method for manufacturing a polyester polyol composition. The method is characterized in that the method comprises the step of providing isohexide, at least a reaction compound and a diol. The reaction compound comprises - and preferably consists of - a dicarboxylic acid or an anhydride of adicarboxylic acid, or combinations thereof. By chemical reaction between the isohexide, the reaction compound and the diol, a polyester polyol composition is obtained comprising polyester polyol molecules comprising primary hydroxyl groups. The isohexide, the reaction compound and the diol are integrated in the polyester polyol molecules.

[0008] T he method of the invention results in a polyester polyol composition that can be used in the production of polyurethane foams, and more particularly in the production of rigid polyisocyanurate foams. The polyester polyol composition that is obtained in the method has the benefit that it uses isohexide, which is a biobased material. Therefore, polyurethane (and more particularly rigid polyisocyanurate foams) can be made with a higher percentage of biobased material. Therefore, more sustainable products can be manufactured thanks to the invention.

[0009] The inventor has surprisingly observed that the use of the polyester polyol composition in the production of polyisocyanurate foams results in rigid foams having good rigidity. The flame retardancy and compression of such foams are similar to polyurethane foams in which aromatic polyester polyol was used in the production of the polyisocyanurate foam.

[0010] With;‘the isohexide, the reaction compound and the diol are integrated in the polyester polyol molecules” is meant that they are integrated in the polyester polyol molecules by chemical reactions.

[0011] Catalysts can be added in the different steps of the reactions. Examples of catalysts that can be used include zinc acetate and titanium butoxide for the condensation reactions. Titanium butoxide is preferably added towards the end of the condensation reaction in order to stimulate the condensing reactions further, when the formation of condensing water is reducing.

[0012] Preferably, the condensing water is evacuated during the condensation reactions, e.g. by means of continuous distillation.During the reactions, the method can comprise the step of continuously or periodically monitoring the acid value in the reaction mixture. Such approach allows to monitor the progress of the reactions, and optionally the timing of add ing components. It is a benefit that such embodiments allow to optimize the polyester polyol which is produced in the method of the invention.

[0013] The method preferably uses only biobased raw materials, possibly except for catalysts that may be used.

[0014] The method of the invention preferably comprises the steps of:

[0015] - providing a mixture comprising isohexide - and preferably all isohexide used in the method - and at least the reaction compound;

[0016] - reacting the isohexide with the reaction compound; thereby obtaining an intermediate reaction product; and

[0017] - reacting the intermediate reaction product with the diol, to obtain the polyester polyol composition.

[0018] In a preferred embodiment, the diol is added to the intermediate reaction product once the condensation reaction between the isohexide and the reaction compound has ended.

[0019] In this embodiment, the diol is added to the intermediate reaction product once the condensation reaction between the isohexide and the reaction compound has ended. The end of the condensation reaction between the isohexide and the reaction compound can be determined by continuously or periodically measuring the acid value. An alternative method is via observing the amount of water generated by the condensation reaction. The condensation reaction between the isohexide and the reaction compound has ended when substantially no more water is generated.

[0020] A preferred method is characterized in that the method comprises the steps of providing a mixture of the isohexide, the at least a reaction compound and the diol; and reacting this mixture.Preferably, this mixture is reacted till no more condensation of water occurs.

[0021] Preferably, this mixture is reacted during which water originating from the condensation reactions is removed, e.g. via continuous distillation.

[0022] Preferably, after reacting the mixture of the isohexide, the at least a reaction compound and the diol; ethylene carbonate is added and allowed to react.

[0023] Such embodiment has the benefit that at least part of the secondary hydroxyl groups present after reacting the mixture of the isohexide, the at least a reaction compound and the diol are converted to primary hydroxyl groups. The presence of primary hydroxyl groups is preferred over secondary hydroxyl groups because of the higher reactivity of primary hydroxyl groups in the reaction with isocyanate in the production of polyurethane or polyisocyanurate. The higher reactivity has been confirmed by practical experiments by the inventor in producing isocyanurate rigid foams.

[0024] Preferably, when adding the ethylene carbonate, a catalyst is added, e.g. potassium carbonate.

[0025] A preferred method according to the first aspect of the invention is characterized in that the method comprises the steps of

[0026] - providing a mixture of isohexide and ethylene carbonate;

[0027] - reacting the isohexide with the ethylene carbonate, thereby obtaining a first intermediate reaction product;

[0028] - adding at least the reaction compound and the diol to the first intermediate reaction product;

[0029] reacting the first intermediate reaction product with the reaction compound and with the diol; thereby obtaining the polyester polyol composition,

[0030] Such embodiment, has the benefit that in the step of reacting the isohexide with the ethylene carbonate, thereby obtaining a first intermediate reaction product, secondary hydroxyl groups are converted into primary hydroxyl groups. This way, it is ensured thatthe polyester polyol molecules comprise less - or even no - secondary hydroxyl groups, but more - or exclusively - primary hydroxyl groups. Primary hydroxyl groups are preferred over secondary hydroxyl groups, because of the higher reactivity of primary' hydroxyl groups in the production of polyurethane or polyisocyanurate compared to secondary hydroxyl groups.

[0031] In the mixture comprising isohexide and ethylene carbonate, the mol ratio of the ethylene carbonate to the isohexide is preferably between 2.4 and 0.6, more preferably higher than 1.6, preferably substantially equal to 2.

[0032] Such embodiments provide optimum results to convert secondary hydroxyl groups into primary hydroxyl groups, and in minimizing or even preventing secondary hydroxyl groups in the polyester polyol molecules.

[0033] The mol ratio of the ethylene carbonate to the isohexide can be higher than 2. It means that the amount of ethylene carbonate is higher than the amount stoichiometrically required for converting the secondary hydroxyl groups of the isohexide to primary hydroxyl groups. Such excess amount is favorable for converting a maximum amount of secondary hydroxyl groups to primary hydroxyl groups. Excess ethylene carbonate can still convert remaining secondary hydroxyl groups to primary hydroxyl groups at the end of the reactions, thereby ensuring a maximum amount of primary hydroxyl groups and a minimum amount of secondary hydroxyl groups in the polyester polyol composition that is obtained in the method.

[0034] The isohexide can preferably be selected from the group consisting of isosorbide, isoidide, isomannide, or combinations thereof.

[0035] Such isohexide products are readily available and are biobased. Isosorbide is particularly preferred, thanks to its best availability.

[0036] Preferably, the polyester polyol molecules obtained comprise on number based average at least 1.8 primary hydroxyl groups, and preferably at least 1.9 primary hydroxyl groups.Such embodiments are preferred as the polyester polyol obtained in the method is very well suited for use as polyol in the production of polyurethane or polyisocyanurate products, e.g. polyisocyanurate rigid foams.

[0037] The amount of primary hydroxyl groups can be determined by means of NMR (Nuclear Magnetic Resonance) techniques.

[0038] The diol used in the method of the invention can preferably be selected from monoethylene glycol (MEG), diethylene glycol, triethylene glycol, polyethylene glycol, butanediol, hexanediol, 1,4-cyclohexanedimethanol, or combinations thereof.

[0039] The use of monoethylene glycol (MEG), butanediol, hexanediol, and 1,4-cyclohexanedimethanol is particularly preferred as they are biobased diols. This way, polyurethane or polyisocyanurate can be produced with an even larger relative amount of biobased material.

[0040] A preferred method is characterized in that the mol ratio of the isohexide to the reaction compound is higher than 0.4, and preferably higher than 0.5, and preferably less than 1.6. The mol ratio of the isohexide to the reaction compound can be less than 0.8. In embodiments wherein after reacting the mixture of the isohexide, the at least a reaction compound and the diol; ethylene carbonate is added and allowed to react, the mol ratio of the iso hexide to the reaction compound is preferably higher than 1.0, and more preferably less than 1.6.

[0041] Such embodiments provide optimum reaction conditions for obtaining a suitable polyester polyol for use in the production of polyurethane or polyisocyanurate rigid foams.

[0042] There are several options for the reaction compound that can be used in the method of the invention. The reaction compound can e.g. be selected from adipic acid, succinicacid, maleic acid, itaconic acid, glutaric acid, phtalic acid, terephthalic acid, their anhydrides, or combinations thereof.

[0043] Specific anhydrides that can be used in the invention are succinic anhydride, maleic anhydride and phthalic anhydride.

[0044] The reaction compound preferably comprises - and more preferably consists of - adipic acid. The inventors have found that the use of adipic acid results in a polyester polyol composition having a suitable viscosity for use in the production of polyisocyanurate foams.

[0045] The reaction compound can comprise - or consist of - a combination of adipic acid and succinic acid (or succinic anhydride), preferably wherein the mol ratio of the adipic acid to the succinic acid (or succinic anhydride) is between 2 / 1 and 1 / 2.

[0046] A preferred embodiment of the method of the invention is characterized in that in the method the mol ratio of the diol to the isohexide is between 0.4 and 3.5; preferably between 1.0 and 2.1, more preferably between 1.3 and 2.0.

[0047] Such embodiment results in an excellent polyester polyol composition for use in the production of rigid polyurethane or polyisocyanurate foams.

[0048] A preferred embodiment of the method of the invention is characterized in that a fatty acid is provided and allowed to react at the same time as the reaction compound.

[0049] Such embodiments are preferred as the polyester polyol composition obtained is better suited for use in the production of polyurethane or polyisocyanurate. The incorporation of the fatty acid in the polyester polyol composition provides the polyester polyol composition with apolar chains. The apolar chains are favorable, as they will facilitate the emulsification of apolar blowing agents (e.g. such as pentane) in the polyester polyol composition in the production process of polyurethane or polyisocyanurate.The fatty acid preferably is a monocarboxylic acid.

[0050] The fatty acid can comprise or consists of a tall oil fatty acid (TOFA). Preferred tall oil fatty acid for use in the invention is or comprises a combination of saturated and unsaturated C18 fatty acids. Tall oil fatty acid (TOFA) is a natural resin product obtained from coniferous wood. The use of tall oil fatty acid (TOFA) in the invention also has the benefit that the amount of biobased raw materials used in the method is increased.

[0051] The use of tall oil fatty acid (TOFA) comprising unsaturated C18 fatty acids has the further benefit that it reduces the viscosity of the polyester polyol composition obtained. It is believed that the presence of the carbon - carbon double bonds in the unsaturated C18 chains reduce de van der Waals forces between molecules, resulting in a reduction of the viscosity of the polyester polyol resulting from the method of the invention. The lower viscosity facilitates processing of the polyester polyol obtained in the method.

[0052] The mol ratio of the fatty acid to the reaction compound is preferably larger than 0.025, and preferably lower than 0.1, more preferably lower than 0.08.

[0053] Such ranges have shown to provide optimum polyester polyol compositions for use in the production of polyurethane or polyisocyanurate in which an apolar blowing agent (e.g. pentane) is used.

[0054] The fatty acid can comprise one or more of a C6, a C7, a C8, a C9, a CIO, a Cl 1, a Cl 2, a CI 3, a C14, a C15, a C17 or a Cl 8 tail fatty acid, or combinations thereof.

[0055] It has been noticed that short tail length fatty acids result in a polyester polyol composition which - when used in the production of polyurethane foam or polyisocyanurate foam --- leads to polyurethane or polyisocyanurate foam with higher compression strength compared to when using fatty’ acids having longer tail length.Therefore, it is preferred that at least 30 percent by weight - and preferably at least 50 percent by weight - of the fatty acid used in the method is C14 or less, more preferably C12 or less.

[0056] A preferred embodiment of the method is characterized in that a fatty alcohol is provided and allowed to react at the same time as the reaction compound.

[0057] Such embodiments are preferred as the polyester polyol composition obtained is better suited for use in the production of polyurethane or polyisocyanurate. The incorporation of the fatty alcohol in the polyester polyol composition provides the polyester polyol composition with apolar chains. The apolar chains are favorable, as they will facilitate the emulsification of apolar blowing agents (e.g. such as pentane) in the polyester polyol composition in the production process of polyurethane or polyisocyanurate.

[0058] The fatty alcohol preferably comprises only one hydroxyl group.

[0059] The mol ratio of the fatty alcohol to the reaction compound is preferably larger than 0.025, and preferably lower than 0.1, more preferably lower than 0.08.

[0060] Such ranges have shown to provide optimum polyester polyol compositions for use in the production of polyurethane or polyisocyanurate in which an apolar blowing agent (e.g. pentane) is used.

[0061] The fatty alcohol can comprise one or more of a C6, a C7, a C8, a C9, a Cl 0, a Cl 1, a C12, a C13, a C14, a C15, a C 17 or a C 18 tail fatty alcohol, or combinations thereof.

[0062] Short tail length fatty alcohols result in a polyester polyol composition which - when used in the production of polyurethane foam or polyisocyanurate foam - leads to polyurethane or polyisocyanurate foam with higher compression strength compared to when using fatty alcohols having longer tail length.Therefore, it is preferred that at least 30 percent by weight - and preferably at least 50 percent by weight - of the fatty alcohols used in the method is C14 or less, more preferably Cl 2 or less.

[0063] The fatty alcohol used can be a saturated fatty alcohol, an unsaturated fatty alcohol, or combinations thereof.

[0064] It is a benefit that fatty alcohols can be biobased, increasing the amount of biobased products used in the method of the invention.

[0065] An example of a fatty alcohol that can be used in the invention is oleyl alcohol, an unsaturated alcohol having a Cl 8 tail.

[0066] A preferred method is characterized in that glycerol is provided and in that the glycerol is allowed to react with the reaction compound and / or with reaction products of a reaction with the reaction compound.

[0067] The use of glycerol in the method is preferred for increasing the functionality of the polyester polyol composition which is obtained in the method.

[0068] The use of lycerol is particularly preferred when tall oil fatty acid or fatty acids are used in the method according to the invention. Tall oil fatty acids and fatty acids have functionality one, whereas glycerol has functionality three. As an example, if the same molar amount of glycerol is added as the molar amount of tall oil fatty acids and fatty acids combined, then a final functionality of two for the polyester polyol composition is obtained.

[0069] A preferred method in which fatty acid and glycerol is used, is characterized in that the mol ratio of the glycerol to the fatty acid is between 0.3 and 3, more preferably between 0.5 and 1.5.It has been noticed that the viscosity of the polyester polyol composition can be high when using glycerol in the method. This can be counteracted by the addition of the fatty acid, preferably in the specified ranges.

[0070] The use of glycerol is particularly preferred when fatty alcohols are used in the method according to the invention. Fatty alcohols have functionality one, whereas glycerol has functionality three. As an example, if the same molar amount of glycerol is added as the molar amount of fatty alcohol, then a final functionality of two for the polyester polyol composition is obtained,

[0071] A preferred method in which faty alcohol and glycerol is used, is characterized in that the mol ratio of the glycerol to the fatty alcohol is between 0.3 and 3, more preferably between 0.5 and 1.5,

[0072] It has been noticed that the viscosity of the polyester polyol composition can be high when using glycerol in the method. This can be counteracted by the addition of the fatty alcohol, preferably in the specified ranges.

[0073] A preferred method is characterized in that glycerol is provided and in that the glycerol is allowed to react with the reaction compound and / or with reaction products of a reaction with the reaction compound; and in that the mol ratio of glycerol to the reaction compound is larger than 0.025, and more preferably lower than 0.1, even more preferably lower than 0,08.

[0074] The use of glycerol is beneficial for the reasons already indicated.

[0075] A preferred embodiment is characterized in that glycerol is provided and in that the glycerol is allowed to react with the reaction compound and / or with reaction products of a reaction with the reaction compound; and in that in the raw materials used in the method the mol ratio of glycerol to the diol is larger than 0.025, and more preferably lower than 0.1, even more preferably lower than 0.08.The use of glycerol is beneficial for the reasons already indicated.

[0076] A preferred method comprises the additional steps of providing ethylene carbonate and reacting the polyester polyol composition obtained with the ethylene carbonate, thereby converting secondary hydroxyl groups into primary hydroxyl groups.

[0077] The additional steps ensure that the polyester polyol composition comprises a maximum amount of primary hydroxyl groups and a minimal, or even no, secondary hydroxyl groups. Such polyol composition is favored for use in the production of polyurethane foam or polyisocyanurate foam thanks to the higher reactivity of primary hydroxyl groups compared to secondary hydroxyl groups.

[0078] The molar amount of ethylene carbonate added in the additional step of providing ethylene carbonate and reacting the polyester polyol composition obtained with the ethylene carbonate, is preferably between 0.5 and 2 times (and more preferably between 0.8 and 1.2 times) the number of free hydroxyl groups of the polyester polyol composition as determined by the hydroxyl number.

[0079] In a preferred embodiment of the invention, the polyester polyol composition obtained has a hydroxyl number (IOH) higher than 170 mg KOH / gram, and more preferably higher than 200 mg KOH / gram, even more preferably higher than 230 mg KOH / gram, and preferably less than 260 mg KOH / gram, even more preferably less than 250 mg KOH / gram.

[0080] Such polyol composition is very well suited for use in the production of polyurethane foam or polyisocyanurate foam.

[0081] A hydroxyl number (IOH) of the polyester polyol composition between 230 and 250 mg KOH / gram is particularly preferred, as it is the optimum range for use of the polyester polyol composition in the production of polyisocyanurate. It is prevented that an excessive amount of expensive di-isocyanate or polyisocyanate is required in the production of the polyisocyanurate, while polyisocyanurate products with excellentproperties can be obtained. A too low hydroxyl number would result in polyisocyanurate products with lower compression strength.

[0082] In a preferred embodiment of the invention, the polyester polyol composition has acid value less than 3 mg KOH / gram, more preferably less than 2 mg KOH / gram, even more preferably less than 1.5 mg KOH / gram.

[0083] A low acid value can be obtained by ensuring a high conversion rate of the condensation reaction. A high conversion rate can be obtained by removing water during the reaction, e.g. by continuous distillation.

[0084] Such polyol composition is very well suited for use in the production of polyurethane foam or polyisocyanurate foam.

[0085] The polyester polyol molecules of the polyester polyol composition obtained in the method preferably have number based average hydroxyl group functionality of at least 1.95, and preferably of at least 2.

[0086] Preferably, the viscosity, measured at 25 °C, of the polyester polyol composition obtained in the method is between 2000 and 7000 mPa.s, and more preferably below 5000 mPa.s.

[0087] Such polyol composition is very well suited for use in the production of polyurethane foam or polyisocyanurate foam.

[0088] A preferred polyol composition obtained in the method of the invention does not comprise aromatic components.

[0089] When ethylene carbonate is used in embodiments of the method according to the invention, carbon dioxide is generated in the chemical reactions involving ethylene carbonate. The carbon dioxide which is formed in the chemical reactions is preferably evacuated.A second aspect of the invention is a polyester polyol composition obtained or obtainable from a method as in any embodiment of the first aspect of the invention.

[0090] A third aspect of the invention is a polyester polyol composition, preferably a polyester polyol composition obtained or obtainable from a method as in any embodiment of the first aspect of the invention. The polyester polyol composition is characterized in that it comprises polyester polyol molecules comprising primary hydroxyl groups. Isohexide, a reaction compound and a diol are integrated in the polyester polyol molecules. The reaction compound comprises - and preferably consists of - a dicarboxylic acid or an anhydride of a dicarboxylic acid, or combinations thereof.

[0091] The polyester polyol composition of the third aspect of the invention can be used in the production of polyurethane foams, and more particularly in the production of rigid polyisocyanurate foams. The polyester polyol composition has the benefit that it uses isohexide, which is a biobased material. Therefore, polyurethane - and more particularly rigid polyisocyanuarate foams - can be made with a higher percentage of biobased material, and even which are 100% biobased.

[0092] The inventor has surprisingly observed that the use of the polyester polyol composition of the invention in the production of polyisocyanurate foams results in rigid foams having good rigidity. The flame retardancy and compression of such foams are similar to polyurethane foams in which aromatic polyester polyol was used in the production of the polyisocyanurate foam.

[0093] With the isohexide, the reaction compound and the diol are integrated in the polyester polyol molecules is meant that they are integrated in the polyester polyol molecules by a chemical reaction,

[0094] A preferred polyol composition according to the invention does not comprises aromatic components.The isohexide, the reaction compound and the diol can be as specified in embodiments of the first aspect of the invention.

[0095] Furthermore, the polyester polyol can comprise any one or more than one of glycerol, fatty acids, fatty alcohol, and ethylene carbonate built into molecules of the polyester polyol. The fatty acids can be as specified in embodiments of the method of the first aspect of the invention.

[0096] A fourth aspect of the invention is a polyurethane formulation, comprising

[0097] - a polyol blend, wherein the polyol blend comprises - and preferably consists of - a polyester polyol composition obtained according to a method of the first aspect of the invention, or according to any embodiment of the second aspect of the invention, or according to any embodiment of the third aspect of the invention;

[0098] - a di-isocyanate and / or a polyisocyanate; and

[0099] - optionally additives such as surfactants, a catalyst, a blowing agent and / or a flame retardant.

[0100] Optionally, other additives can be added in the polyurethane formulation.

[0101] The polyurethane composition may comprise a blowing agent comprising water and an auxiliary physical blowing agent. Examples of suitable auxiliary blowing agents that can be used in the invention are cyclic or linear aliphatics, pentane, hexane, cyclo-pentane, iso-pentane, chlorofluorocarbons (CFCs), hydrogenated fluorocarbons (HFCs), hydrogenated chlorofluoro- carbons (HCFCs), hydrofluoroethers (HFEs), hydrofluoro olefins (HFO), methylal, methylformate; or combinations thereof.

[0102] Embodiments wherein fatty acids, e.g. tall oil fatty acids (TOFA), have been added in the production process of the polyester polyol composition are beneficial for emulsifying the auxiliary blowing agents - and especially apolar auxiliary blowing agents - in the polyurethane formulation.Embodiments wherein fatty alcohols have been added in the production process of the polyester polyol composition are beneficial for emulsifying the auxiliary blowing agents - and especially apolar auxiliary blowing agents - in the polyurethane formulation.

[0103] A preferred polyurethane formulation is characterized in that the formulation comprises at least a surfactant, more preferably a silicone surfactant.

[0104] Preferably, the hydroxyl number (IOH) of the polyol blend of the polyurethane formulation is between 150 to 300 mg KOH / gram.

[0105] Such values have proven to result in polyurethane foams with excellent properties.

[0106] The polyol blend may comprise at least 25 wt%, and preferably at least 30 wt%, of a polyester polyol composition according to the second aspect of the invention, or according to the third aspect of the invention, or obtained from a method according to the first aspect of the invention.

[0107] The polyol blend preferably provides less than 55 wt% - and more preferably less than 35 wt% - of the polyurethane composition.

[0108] A preferred polyurethane composition is a composition for producing a polyisocyanurate foam. The isocyanurate bonds in polyisocyanurate foams provide high rigidity. The isohexide in the polyester polyol composition used contributes to the high rigidity.

[0109] A fifth aspect of the invention is a polyurethane product, characterized in that the polyurethane product is obtained by reacting a polyurethane formulation according to any embodiment of the fourth aspect of the invention. The polyurethane product preferably is a polyisocyanurate product, more preferably a rigid polyisocyanurate foam product.The following section describes the chemical structure of raw materials that can be used in the invention, and of intermediate products and of molecules of the polyester polyol obtained in the method of the invention.

[0110] Isosorbide, that can be used as raw material in the method of the invention is presented by formula:

[0111]

[0112] The diol used in the method can be selected from molecules or from combinations of molecules such as:

[0113] or

[0114]

[0115] Dicarboxylic acid that can be used in the invention corresponds to the formula:

[0116]

[0117] n

[0118] Glycerol is presented by the formula

[0119]

[0120] The chemical reaction between isosorbide and dicarboxylic acid can result in intermediate products represented by formula 1:

[0121]

[0122] The product presented in formula 1 is preferably the main compound of methods wherein the isosorbide reacts with the dicarboxylic acid, even if glycerol and / or fatty acids (e.g. tall oil fatty acid) and / or fatty alcohols is added before this reaction step. Besides the main intermediate product, other intermediate products may be formed, e.g. intermediate products comprising secondary hydroxyl groups.

[0123] In methods wherein glycerol is added, intermediate products --- meaning reaction products obtained before reaction with the diol - can include molecules of some or of all of the following molecules:

[0124]

[0125]

[0126] A reaction can also occur between glycerol and a dicarboxylic acid when used as reaction compound, resulting in an intermediate product of the following chemical structure:

[0127] O OH

[0128]

[0129] After reaction with the diol, the intermediate product presented by formula 1 of the chemical reaction between isosorbide and dicarboxylic acid will be converted mainly in the following polyester polyol molecules comprising primary hydroxyl groups:

[0130]

[0131] If intermediate products were present from reactions involving glycerol, these intermediate products can also be converted to polyester polyol molecules via a chemical reaction with the diol.

[0132] The method of the invention optionally provides the use of ethylene carbonate. A preferred method comprises the step of providing a mixture of isohexide and ethylene carbonate; and reacting the isohexide with the ethylene carbonate, thereby obtaining a first intermediate reaction product. This first intermediate product can be represented by the following chemical reaction:

[0133]

[0134] This reaction can then be followed by addition to the first intermediate reaction product of at least the reaction compound and the diol; and by reacting the first intermediate reaction product with the reaction compound and with the diol; thereby obtaining the polyester polyol composition.

[0135] A preferred embodiment of the invention comprises the additional steps of providing ethylene carbonate; and reacting the polyester polyol composition obtained with the ethylene carbonate. This allows the conversion of secondary hydroxyl groups intoprimary hydroxyl groups. In such embodiment of the invention, the reaction of the ethylene carbonate can comprise the following reactions:

[0136]

[0137] A number of examples of the invention will be described in the following paragraphs.

[0138] Recipe 1 provides an example of a recipe that can be used in the method according to the invention:

[0139] isosorbide 16.4 mol%

[0140] monoethylene glycol 41.8 mol%

[0141] glycerol 1.9 mol%

[0142] - adipic acid 38.1 mol%

[0143] - tall oil fatty acid (TOFA) 1.9 mol%

[0144] and in addition suitable catalysts.

[0145] The isosorbide, the adipic acid, the tall oil fatty acid and the glycerol are blended and allowed to react at 235 °C. Once the condensation reaction stopped, the monoethylene glycol is added and allowed to react at 210°C. The resulting polyol composition comprises polyester polyol molecules having primary hydroxyl groups. The polyesterpolyol composition obtained had hydroxyl value (IOH) 174 mg KOH / g, acid value 1.5 mg KOH / g and viscosity (measured at 25 °C) 3337 mPa.s.

[0146] Recipe 2 provides an example of a recipe that can be used in the method according to the invention:

[0147] isosorbide 20.0 mol%

[0148] monoethylene glycol 40.0 mol%

[0149] glycerol 1.1 mol %

[0150] adipic acid 37.8 mol%

[0151] - tall oil fatty acid (TOFA) 1.1 mol%

[0152] and in addition suitable catalysts.

[0153] The isosorbide, the adipic acid, the tall oil fatty acid and the glycerol were blended and allowed to react at 235 °C. Once the condensation reaction stopped, the monoethylene glycol is added and allowed to react at 210°C. The resulting polyol composition comprises polyester polyol molecules having primary hydroxyl groups. The polyester polyol composition obtained had hydroxyl value (IOH) 236 mg KOH / g, acid value 0.5 mg KOH / g and viscosity (measured at 25 °C) 2037 mPa.s.

[0154] Using 2.6 equivalents of polymeric methylene diphenyl diisocyanate (pMDI) relative to the polyester polyol composition: and using appropriate additives (blowing agent, catalyst, surfactants...) a laboratory sample of a polyisocyanurate foam was made using the polyester polyol composition obtained from recipe 2. The resulting polyisocyanurate foam had the following properties:

[0155] density 28.9 kg / m3

[0156] thermal insulation value (lambda) 23.6 mW / (m*K) compression strength (foam rise direction) 219 kPa

[0157] compression counter rise direction 91.3 kPa

[0158] Flammability was also tested and showed to be good, even if the polyester polyol composition used in the production of the polyisocyanurate foam did not comprise aromatic compounds.Recipes 3, 4 and 5 comprise varying amounts of isosorbide (respectively 20 mol%, 25 mol% and 30 mol%). Recipes 3, 4 and 5 are listed in Table 1. The recipes have been used in the same way as with recipes 1 and 2 to produce polyester polyol compositions. With the polyester polyol compositions obtained with recipes 3, 4 and 5, polyisocyanurate foam samples have been prepared in laboratory conditions in the same way as prepared with recipe 2.

[0159] Recipe 3 Recipe 4 Recipe 5 Isosorbide 20.0 mol% 24,9 mol% 30.0 mol% Monoethylene 40.0 mol % 35.7 mol% 31.0 mol% glycol

[0160] Glycerol 1.1 mol % 1.1 mol% 1.1 mol% Adipic acid 37.8 mol% 37.2 mol% 36.8 mol%

[0161] Tall oil fatty acid 1.1 mol % 1.1 mol% 1.1 mol%

[0162]

[0163] Table 1: Composition of recipes 3, 4 and 5

[0164] ? 0

[0165] The results obtained with recipes 3, 4 and 5 are summarized in Table 2. Table 2 lists the hydroxyl value, the acid value and the viscosity of the polyester polyol compositions made; and the foam density, thermal insulation value (lambda), compression strength in the rise direction and the compression strength in the counter rise direction of the 15 polyisocyanurate samples that have been made.Recipe 3 Recipe 4 Recipe 5 Hydroxyl value 198 226 180

[0166] (IOH), mg KOH / g

[0167] Acid value, mg 1.4 1.8 0.5

[0168] KOH / g

[0169] Viscosity, mPa.s 2850 3325 4987

[0170] Foam density, 32.8 30.2 30.9

[0171] kg / m3

[0172] Lambda, 23.03 23.45 23.68 mW / (m*K)

[0173] Compression 256 242 250

[0174] strength rise

[0175] direction, kPa

[0176] Compression 75.8 83.8 81.9

[0177] counter rise

[0178] direction, kPa

[0179]

[0180] Table 2: results obtained with recipes 3, 4 and 5

[0181] Recipes 6, 7 and 8 comprise varying amounts of tall oil fatty acid (respectively 1 mol%, 2 mol% and 3 mol%). The recipes have been adjusted as indicated in Table 3. With the polyester polyol compositions obtained from recipes 6, 7 and 8, polyisocyanurate foam samples have been prepared in laboratory conditions in the same way as with the other recipes.Recipe 6 i Recipe 7 Recipe 8 Isosorbide 24.9 mol% 1 25.0 mol% 25.0 mol% Monoethylene 35.7 mol% | 34.3 mol% 33.0 mol% glycol

[0182] Glycerol 1.0 mol% | 2.0 mol% 3.0 mol% Adipic acid 37.2 mol.% | 36.6 mol% 35.9 mol% Tall oil fatty acid 1.0 mol % | 2.0 mol% 3.0 mol%

[0183]

[0184] 1

[0185] Table 3: composition of recipes 6, 7 and 8

[0186] The results obtained with recipes 6, 7 and 8 are summarized in the Table 4:

[0187] Recipe 6 Recipe 7 Recipe 8 Hydroxyl value 237 235 243 (IOH), mg K. OH / g

[0188] Acid value, mg 1.8 0.9 1.2 KOH / g

[0189] Viscosity, mPa.s 3112 3437 2912 Foam density, 32.2 32.0 31.8 kg / m3

[0190] Lambda, 23.05 23.07 23.29 mW / (m*K)

[0191] Compression 244 243 228 strength rise

[0192] direction, kPa

[0193] Compression 79 75 74 counter rise

[0194] direction @ ref

[0195] density, kPa

[0196]

[0197] Table 4: test results obtained with recipes 6, 7 and 8Recipe 9 provides an example of a recipe that can be used in the method according to the invention:

[0198] isosorbide 25.0 mol%

[0199] monoethylene glycol 35.8 mol%

[0200] - glycerol 1.0 mol%

[0201] adipic acid 37.2 mol%

[0202] tall oil fatty acid (TOFA) 0.3 mol%

[0203] lauric acid 0.7 mol%

[0204] and in addition suitable catalysts.

[0205] The isosorbide, the adipic acid, the tall oil fatty acid, the lauric acid and the glycerol were blended and allowed to react at 235 °C. Once the condensation reaction stopped, the monoethylene glycol is added and allowed to react at 210°C. The resulting polyol composition comprises polyester polyol molecules having primary hydroxyl groups. The polyester polyol composition obtained had hydroxyl value (IOH) 259 mg KOH / g, acid value 1.2 mg KOH / g and viscosity (measured at 25 °C) 3350 mPa.s.

[0206] Using 2.6 equivalents of polymeric methylene diphenyl diisocyanate (pMDI) relative to the polyester polyol composition; and using appropriate additives (blowing agent, catalyst, surfactant...) a laboratory sample of a polyisocyanurate foam was made using the polyester polyol composition obtained from recipe 9. The resulting polyisocyanurate foam had the following properties:

[0207] density 32.2 kg / m3

[0208] thermal insulation value (lambda) 23.59 mW / (m* K)

[0209] - compression strength (foam rise direction) 267 kPa

[0210] compression counter rise direction @ pref, kPa 108 kPa

[0211] Flammability was also tested and showed to be good, even if the polyester polyol composition used in the production of the polyisocyanurate foam did not comprise aromatic compounds.Recipe 10 provides an example of a recipe that can be used in a method according to the invention.

[0212] isosorbide 26.9 mol%

[0213] monoethylene glycol 14.0 mol%

[0214] glycerol 1.0 mol%

[0215] adipic acid 19.8 mol%

[0216] tall oil fatty acid (TOFA) 0.3 mol%

[0217] lauric acid 0.7 mol%

[0218] ethylene carbonate 36.8 mol%

[0219] and in addition suitable catalysts.

[0220] The isosorbide, the adipic acid, the tall oil fatty acid, the lauric acid and the glycerol were blended and allowed to react at 235 °C. Once the condensation reaction stopped, the monoethylene glycol is added and allowed to react at 210°C.

[0221] Then the temperature is reduced, the ethylene carbonate is added and allowed to react at 170°C in the presence of potassium carbonate acting as catalyst. In this reaction, carbon dioxide is released and evacuated. In this reaction, secondary hydroxyl groups are converted in primary hydroxyl groups.

[0222] The use of the ethylene carbonate in recipe 10 indeed showed to increase the overall reactivity, meaning that the total reaction time was lower than without using ethylene carbonate.

[0223] The resulting polyol composition comprised polyester polyol molecules with primary hydroxyl groups. The polyester polyol composition obtained had hydroxyl value (IOH) 251 mg KOH / g, acid value 0.4 mg KOH / g and viscosity (measured at 25 °C) 3750 mPa.s.

[0224] Using 2.6 equivalents of polymeric methylene diphenyl diisocyanate (pMDI) relative to the polyester polyol composition; and using appropriate additives (blowing agent, catalyst, surfactant...) a laboratory sample of a polyisocyanurate foam was made usingthe polyester polyol composition obtained from recipe 10. The resulting polyisocyanurate foam had the following properties:

[0225] density 31.7 kg / m3

[0226] thermal insulation value (lambda) 23.69 mW / (m*K) compression strength (foam rise direction) 231 kPa

[0227] compression counter rise direction @ pref, kPa 74.6 kPa

[0228] Flammability was also tested and showed to be good, even if the polyester polyol composition used in the production of the polyisocyanurate foam did not comprise aromatic compounds.

[0229] Recipe 11 provides an example of a recipe that can be used in a method according to the invention:

[0230] functionalized isosorbide 40.4 mol%

[0231] monoethylene glycol 25.6 mol%

[0232] - glycerol 1.0 mol%

[0233] adipic acid 32.0 mol%

[0234] tall oil fatty acid (TOFA) 1.0 mol%

[0235] and in addition suitable catalysts.

[0236] The functionalized isosorbide (as first intermediate reaction product) is obtained as the reaction product of isosorbide and ethylene carbonate using the following recipe:

[0237] isosorbide 33.1 mol%

[0238] ethylene carbonate 66.2 mol%

[0239] and in addition suitable catalysts.

[0240] In a first stage, the ethylene carbonate is added to the isosorbide together with potassium carbonate as a catalyst and allowed to react at 170 °C. During the reaction CO2is released and evacuated. Once the reaction is complete, as can be monitored by FT-IR, the temperature is reduced and the remaining components are added (the monoethylene glycol, the glycerol, the adipic acid and the tall oil fatty acid). The temperature of the reaction mixture is increased to 210 °C and allowed to react till completion of thereaction. The resulting polyol composition comprised polyester polyol molecules with primary hydroxyl groups. The polyester polyol composition obtained had hydroxyl value (IOH) 251 mg KOH / g, acid value 1.6 mg KOH / g and viscosity (measured at 25 °C) 2437 mPa.s.

[0241] The inventor has noticed that the properties of the polyisocyanurate foams made can be modified and optimized via optimization of the surfactants used. Using routine experimentation with commercially available surfactants that can be used for polyurethane or polyisocyanurate rigid foam production, it is possible to optimize the properties of the rigid foams, e.g. to optimize the lambda insulation value of the polyisocyanurate rigid foam.

[0242] Although in all recipe examples isosorbide has been used, it is clear that other isohexides can be used in the invention instead of isosorbide, or partly replacing the isohexide.

[0243] Although in all examples monoethylene glycol has been used as polyol, other diols can be used in the invention partially or fully replacing the monoethylene glycol.

[0244] Although in the examples adipic acid has been used, other dicarboxylic acids or an anhydride of a dicarboxylic acid, or combinations thereof, can be used in the invention.

[0245] Although in most examples tall oil fatty acid (TOFA) has been used as fatty acid, other fatty acids can be used instead in the invention, in full or in partial replacement of the tall oil fatty acid (TOFA).

[0246] Although in all recipe examples a fatty acid has been used, it is also possible to replace all or part of the fatty acid by a fatty alcohol or by a combination of fatty alcohols, whether saturated faty alcohols or unsaturated fatty alcohols or a combination of saturated and unsaturated fatty alcohols.The present invention is in no way limited to the embodiments described as an example, on the contrary it can be realized in various forms and dimensions, without leaving the scope of the invention.

Claims

1.Claims1 Method for manufacturing a polyester polyol composition, characterized in that the method comprises the step of providing isohexide, at least a reaction compound and a diol; wherein the reaction compound comprises - and preferably consists of - a dicarboxylic acid or an anhydride of a dicarboxylic acid, or combinations thereof; wherein by chemical reaction between the isohexide, the reaction compound and the diol, a polyester polyol composition is obtained comprising polyester polyol molecules comprising primary hydroxyl groups, wherein the isohexide, the reaction compound and the diol are integrated in the polyester polyol molecules.2.- Method for manufacturing a polyester polyol composition as in claim 1, characterized in that the method comprises the steps of- providing a mixture comprising isohexide and at least the reaction compound; - reacting the isohexide with the reaction compound, thereby obtaining an intermediate reaction product; and- reacting the intermediate reaction product with the diol, to obtain the polyester polyol composition.3.- Method as in claim 2, characterized in that the diol is added to the intermediate reaction product once the condensation reaction between the isohexide and the reaction compound has ended.4.- Method as in claim 1, characterized in that the method comprises the steps of providing a mixture of the isohexide, the at least a reaction compound and the diol; and reacting this mixture.5.- Method for manufacturing a polyester polyol composition as in claim 1, characterized in that the method comprises the steps of- providing a mixture of isohexide and ethylene carbonate;- reacting the isohexide with the ethylene carbonate, thereby obtaining a firstintermediate reaction product;- adding at least the reaction compound and the diol to the first intermediate reaction product;reacting the first intermediate reaction product with the reaction compound and with the diol; thereby obtaining the polyester polyol composition.6.- Method as in claim 5, characterized in that in the mixture comprising isohexide and ethylene carbonate, the mol ratio of the ethylene carbonate to the isohexide is between 2.4 and 0.6; preferably wherein the mol ratio of the ethylene carbonate to the isohexide is higher than 1.6; preferably wherein the mol ratio of the ethylene carbonate to the isohexide is substantially equal to 2.7.- Method as in any of the preceding claims, characterized in that the isohexide is selected from the group consisting of isosorbide, isoidide, isomannide, or combinations thereof.8.- Method as in any of the preceding claims, characterized in that the polyester polyol molecules comprise on number based average at least 1.8 primary hydroxyl groups, and preferably at least 1.9 primary hydroxyl groups.9.- Method as in any of the preceding claims, characterized in that the diol is selected from monoethylene glycol (MEG), diethylene glycol, triethylene glycol, polyethylene glycol, butanediol, hexanediol, 1,4-cyclohexanedimethanol, or combinations thereof.10.- Method as in any of the preceding claims, characterized in that in the method the mol ratio of the isohexide to the reaction compound is higher than 0.4, and preferably higher than 0.5, and preferably less than 1.6.11.- Method as in any of the preceding claims, characterized in that the reaction compound is selected from adipic acid, succinic acid, maleic acid, itaconic acid, glutaric acid, phtalic acid, terephthalic acid, their anhydrides, or combinations thereof.12.- Method as in any of the preceding claims, characterized in that in the method the mol ratio of the diol to the isohexide is between 0.4 and 2.1; preferably between 1.1 and 2.7, more preferably between 1.3 and 2.0.13.- Method as in any of the preceding claims, characterized in that in the method a fatty acid is provided and allowed to react at the same time as the reaction compound; preferably wherein the fatty acid comprises or consists of a tall oil fatty acid (TOFA).14.- Method as in claim 13, characterized in that the mol ratio of the fatty acid to the reaction compound is larger than 0.025, and preferably lower than 0.1, more preferably lower than 0.08.15.- Method as in claims 13 or 14, characterized in that the fatty acid comprises one or more of a C6, a C7, a C8, a C9, a C10, a C11, a C12, a C13, a C14, a C15, a C17 or a C18 tail fatty acid, or combinations thereof.16.- Method as in any of the preceding claims, characterized in that in the method a fatty alcohol is provided and allowed to react at the same time as the reaction compound; preferably wherein the fatty alcohol comprises or consists of one or more of a C6, a C7, a C8, a C9, a C10, a C11, a C12, a C13, a C14, a C15, a C17 or a C18 fatty alcohol.17.- Method as in any of the preceding claims, characterized in that glycerol is provided and in that the glycerol is allowed to react with the reaction compound and / or with reaction products of a reaction with the reaction compound.18.- Method as in any of the preceding claims 13 - 15 and as in claim 17, characterized in that the mol ratio of the glycerol to the fatty acid is between 0.3 and 3, preferably between 0.5 and 1.5.19.- Methode as in claim 16 and as in claim 17 or 18, characterized in that the mol ratio of the glycerol to the fatty alcohol is between 0.3 and 3, preferably between 0.5 and 1.5.20.- Method as in any of the preceding claims, characterized in that glycerol is provided and in that the glycerol is allowed to react with the reaction compound and / or with reaction products of a reaction with the reaction compound; and in that the mol ratio of glycerol to the reaction compound is larger than 0.025, and preferably lower than 0.1, more preferably lower than 0.08.21.- Method as in any of the preceding claims, characterized in that glycerol is provided and in that the glycerol is allowed to react with the reaction compound and / or with reaction products of a reaction with the reaction compound; and in that in the raw materials used in the method the mol ratio of glycerol to the diol is larger than 0.025, and preferably lower than 0.1, more preferably lower than 0.08.22.- Method as in any of the preceding claims, characterized in that the method comprises the additional steps of providing ethylene carbonate and reacting the polyester¬ polyol composition obtained with the ethylene carbonate, thereby converting secondary hydroxyl groups into primary hydroxyl groups.23.- Method as in claim 22, characterized in that in the additional step of providing ethylene carbonate and reacting the polyester polyol composition obtained with the ethylene carbonate, the molar amount of ethylene carbonate added is between 0.5 and 2 times the number of free hydroxyl groups of the polyester polyol composition as determined by the hydroxyl number.24.- Method as in any of the preceding claims, characterized in that the polyesterpolyol composition obtained has a hydroxyl number (IOH) higher than 170 mg KOH / gram, and preferably higher than 200 mg KOH / gram, more preferably higher than 230 mg KOH / gram, and preferably less than 260 mg KOH / gram, more preferably less than 250 mg KOH / gram.25.- Method as in any of the preceding claims, characterized in that the polyester polyol composition has acid value less than 3 mg KOH / gram, preferably less than 2 mg KOH / gram, even more preferably less than 1.5 mg KOH / gram.26.- Method as in any of the preceding claims, characterized in that the polyester polyol molecules of the polyester polyol composition have number based average hydroxyl group functionality of at least 1.95, and preferably of at least 2.27.- Method as in any of the preceding claims, characterized in that the viscosity of the polyester polyol composition measured at 25 °C is between 2000 and 7000 mPa.s, and preferably below 5000 mPa.s.28.- Method as in any of the preceding claims, characterized in that the polyester polyol composition does not comprise aromatic components.29.- Polyester polyol composition obtained or obtainable from a method as in any of the preceding claims.30.- Polyester polyol composition, preferably a polyester polyol composition as in claim 29, characterized in that the polyester polyol composition comprises polyester polyol molecules, wherein the polyester polyol molecules comprise primary hydroxyl groups; wherein isohexide, a reaction compound and a diol are integrated in the polyester polyol molecules;wherein the reaction compound comprise - and preferably consists of - a dicarboxylic acid or an anhydride of a dicarboxylic acid, or combinations thereof.31.- Polyol composition as in claims 29 or 30, characterized in that the polyester polyol composition does not comprise aromatic components.32.- Polyurethane formulation, comprising- a polyol blend, wherein the polyol blend comprises - and preferably consists of - a polyester polyol composition as in any of the preceding claims 29 -32, or obtained froma method as in any of the preceding claims 1 - 28;- a di-isocyanate and / or a polyisocyanate; and- optionally additives such as surfactants, a catalyst, a blowing agent and / or a flame retardant.533.- Polyurethane formulation as in claim 32, characterized in that the polyurethane composition comprises a blowing agent comprising water and an auxiliary physical blowing agent, e.g. cyclic or linear aliphatics, pentane, hexane, cyclo-pentane, iso¬ pentane, chlorofluorocarbons (CFCs), hydrogenated fluorocarbons (HFCs), 0 hydrogenated chlorofluoro- carbons (HCFCs), hydrofluoroethers (HFEs), hydrofluoro olefins (HFO), methylal, methylformate; or combinations thereof.34.- Polyurethane formulation as in any of the preceding claims 32 - 33, characterized in that the formulation comprises at least a surfactant, preferably a silicone surfactant. g35.- Polyurethane formulation as in any of the preceding claims 32 - 34, characterized in that the hydroxyl number of the polyol blend is between 150 to 300 mg KOH / gram.36.- Polyurethane composition as in any of the preceding claims 32 - 35, characterized 0 in that the polyol blend comprises at least 25 wt%, and preferably at least 30 wt%, of a polyester polyol composition as in any of the preceding claims 30 - 32, or obtained from a method as in any of the preceding claims 1 - 28.37.- Polyurethane composition as in any of the preceding claims 32 - 36, characterized 5 in that the polyol blend provides less than 55 wt% - and preferably less than 35 wt% - of the polyurethane composition.38.- Polyurethane composition as in any of the preceding claims 32 - 37, characterized in that the polyurethane composition is a composition for producing a polyisocyanurate 0 foam.39.- Polyurethane product, characterized in that the polyurethane product is obtained by reacting a polyurethane formulation as in any of the preceding claims 32- 38.