Polyol of natural origin useful for the preparation of polyurethane

Abstract

The present invention relates to a polyol of formula (I), obtained from resources of natural origin, to a method for preparing same, to uses thereof for preparing a polyurethane, and to a vehicle part comprising such a polyurethane.

Description

[0001] TITLE: Naturally derived polyol useful for the preparation of polyurethane

[0002] The present invention relates to a polyol derived from natural resources, its preparation process and its use for the preparation of polyurethane useful in particular for the preparation of vehicle parts.

[0003] Polyurethanes have numerous applications. They are prepared from polyol and diisocyanate.

[0004] We seek to make polyurethanes and their preparation processes more environmentally friendly by using less fossil-based raw materials to prepare them and more natural-based raw materials, but while retaining the properties of a polyurethane made from fossil-based raw materials, in particular mechanical properties.

[0005] One of the objectives of the application is to provide a naturally derived polyol-type compound that allows the preparation of a polyurethane with mechanical properties similar to those of a polyurethane prepared from fossil-derived polyols.

[0006] Another objective of the application is to supply a polyurethane prepared from such a naturally occurring polyol-type compound.

[0007] To this end, according to a first object, the invention relates to a compound of formula (I): in which: n is an integer from 2 to 3, preferably 2, each R-COO- is independently a mono- or polyunsaturated fatty acid residue at C8 to C24,

[0008] G represents an alkyl radical of valence n and comprising from 3 to 35, in particular from 4 to 12 carbon atoms, the alkyl radical being substituted by at least two hydroxyl groups (in particular secondary), preferably at least three hydroxyl groups (in particular secondary), and possibly being interrupted by one or more oxygen atoms.

[0009] The compound of formula (I) comprises a radical G containing at least two hydroxyl groups, preferably at least three. It is therefore a polyol. Generally, the radical G contains 10 or fewer hydroxyl groups. Preferably, the radical G contains from 2 to 8, for example, from 3 to 6 hydroxyl groups. Advantageously, the radical G contains at least two secondary hydroxyl groups, preferably at least three. For example, the radical G contains 10 or fewer secondary hydroxyl groups. Preferably, the radical G contains from 2 to 8, for example, from 3 to 6 secondary hydroxyl groups. In particular, all the hydroxyl groups on the radical G are secondary hydroxyl groups.

[0010] A "secondary hydroxyl" is a hydroxyl group (OH) attached to a secondary carbon atom, meaning one that is bonded to only one hydrogen atom. Thus, the carbon atom is bonded to the hydroxyl group, to a hydrogen atom, and to two other groups that are not hydrogen atoms.

[0011] The alkyl radical, possibly interrupted by one or more oxygen atoms, of group G can be linear, branched or cyclic.

[0012] The alkyl radical of group G can be interrupted by one or more oxygen atoms and thus comprise one or more ether groups. It can then be a monoether or a polyether. Two oxygen atoms are generally not adjacent, so the compound of formula (I) is usually free of a peroxide group (-OO-).

[0013] The compound of formula (I) comprises at least two R-COO- groups, which are mono- or polyunsaturated fatty acid residues in positions O8 to C24, preferably O12 to O24, and therefore advantageously of natural origin. Thus, the compound of formula (I) has a lower carbon footprint than a compound whose radicals are derived from fossil fuels. The compound of formula (I) advantageously consists of radicals of which at least 15% by weight are of natural origin. This is referred to as "biocontent."

[0014] Each R-COO- is a mono- or polyunsaturated fatty acid residue at positions O8 to C24, preferably O12 to C24. Within the compound of formula (I), the R-COO- groups may be identical or different. Thus, each R-COO- is a fatty acid residue chosen from among saturated fatty acids (R is then a linear or branched alkyl group comprising 7 to 23 carbon atoms) and mono- or polyunsaturated fatty acids (R is then a linear or branched alkenyl group comprising one or more unsaturations and comprising 7 to 23 carbon atoms). Examples of saturated fatty acids include lauric acid (012), myristic acid (014), palmitic acid (016), stearic acid (018), arachidic acid (020), behenic acid (022), and lignoceric acid (C24).Among the monounsaturated and polyunsaturated fatty acids, we can mention myristoleic acid (14:1), palmitoleic acid (16:1), sapienic acid (16:1), oleic acid (18:1), elaidic acid (18:1), trans-vaccenic acid (18:1), linoleic acid (18:2), linolelaidic acid (18:2), eicosenoic acid (20:1), and erucic acid (22:1). Among the triunsaturated fatty acids, we can mention linolenic acid (018:3). The G radicals originate from compounds with the formula G-(OH). n Naturally derived radicals are particularly preferred. In this case, advantageously, both the RCOO and G radicals are of natural origin. The compound of formula (I) is then advantageously composed of radicals that are 100% by weight of natural origin.

[0015] Preferably, in formula (I), the radical G is, according to a first alternative, a residue of a compound of formula G-(OH) nwhere G is an alkylene, an alkylene oxide or an alkylene polyoxide, said alkylene, alkylene oxide or alkylene polyoxide being substituted by at least two -(CH2)j-OH groups, preferably at least three -(CH2)j-OH groups), where, in each -(CH2) r OH, i independently represents 0 or 1, preferably 0, it being understood that the total number of carbon atoms in group G is from 3 to 35, in particular from 4 to 12.

[0016] As examples, the radical G can be a residue of a compound with the formula G-(OH) n where n is as defined above, where the compound G-(OH) n is pentaerythritol, a polyglycerol or an alditol.

[0017] Examples of alditols include erythritol (04), threitol (04), arabitol (05), xylitol (05), ribitol (05), mannitol (06), sorbitol (06), galactitol (06), fucitol (06), iditol (06), volmitol (07), isomalt (012), maltitol (012), lactitol (012) and glycerol, where sorbitol, xylitol, mannitol and glycerol are particularly preferred.

[0018] Typically, n represents 2 and the radical G has one of the formulas (II) to (V) described below, in particular one of the formulas (II), (III) and (V): in which m represents an integer from 1 to 10, in particular from 2 to 5, preferably from 2 to 3, in which p represents 1 or 2,

[0019] When the G radical has formula (II), it is a residue of a compound with the formula G-(OH)2, which is a polyglycerol containing 2 to 11 glycerol units. When the G radical has formula (III), it is a residue of a compound with the formula G-(OH)2, which is an alditol containing 5 or 6 carbon atoms, such as sorbitol, xylitol, or mannitol.

[0020] When the radical G has the formula (IV), it is a residue of a compound with the formula G-(OH)2, which is pentaerythritol.

[0021] According to a second alternative, in formula (I), the radical G is preferably a sugar derivative chosen from a monosaccharide, a disaccharide, an oligosaccharide comprising 3 to 10 oses, a polysaccharide comprising 11 to 30 oses, a methyl monoether of mono-, di- or oligo-saccharide, or an oligomer of these, it being understood that the total number of carbon atoms of group G is from 3 to 35, in particular from 4 to 12 carbon atoms.

[0022] Examples of monosaccharides include hexoses such as allose, galactose, glucose, mannose, and fructose.

[0023] Examples of disaccharides include maltose, lactose, and sucrose.

[0024] Methyl glucoside can be cited as an example of a mono- or di-saccharide methyl ether.

[0025] Examples of polysaccharides include cellulose, hemicellulose, and lignocellulose.

[0026] Typically, n represents 2 and the radical G has the formula (V) described below:

[0027] The radical G of formula (V) is then a residue of a compound of formula G-(OH)2 which is sucrose.

[0028] The compound of formula (I) preferably has: a hydroxyl value of 20 to 210 mg KOH / g, preferably 20 to 150 mg KOH / g, as measured according to method A of standard NF EN ISO 14900:2023; an acid value less than or equal to 1.0 mg KOH / g, preferably less than or equal to 0.7 mg KOH / g, as measured according to standard NF EN ISO 660:2020; and / or a viscosity at 20°C of 400 to 20,000 mPa·s, preferably 400 to 10,000 mPa·s, even more preferably 400 to 5,000 mPa·s, as measured with a shear rate between 0.1 and 100 s⁻¹ -1 .

[0029] The compound of formula (I) is generally obtained by esterification of at least one mono- or polyunsaturated fatty acid in C8 to C24, preferably in C12 to C24, with a polyol of formula G-(OH) n in which n and G are as defined above. Typically, esterification is carried out with a fatty acid / polyol molar ratio G-(OH)n less than or equal to n. The ratio must not exceed n so that at least two hydroxyl groups of group G are not esterified.

[0030] For example, when n equals 2, the esterification is as follows:

[0031] 2 R-COOH + G-fOHJg- R-COO-G-OOC-R, it being understood that the two Rs are identical or different. The fatty acid / polyol molar ratio G-(OH)2 is then preferably less than or equal to 2, typically 2.

[0032] Thus, the invention also relates to a mixture comprising at least two compounds of formula (I).

[0033] In particular, such a mixture can be obtained by esterification of an oil hydrolysate, preferably vegetable, comprising several mono- or polyunsaturated fatty acids in C8 to C24, preferably in C12 to C24, with a polyol of formula G-(OH) nin which n and G are as defined above. According to another example, such a mixture can be obtained by esterification of mono- or polyunsaturated fatty acids in O8 to O24 from refining processes, for example acid oil, or from the paper industry, for example tallol, with a polyol of formula G-(OH) n in which n and G are as defined above.

[0034] According to a second object, the invention relates to a process for preparing a compound of formula (I) as defined above comprising the esterification of a polyol of formula G-(OH) n in which n and G are as defined above with a mono- or polyunsaturated fatty acid in 08 to 024, preferably in 012 to 024.

[0035] Preferably, esterification is carried out using a molar ratio of fatty acid(s) to polyol of formula G-(OH) n compared to the number of equivalents as defined above.

[0036] The process may include, after esterification, a step of purification of the compound of formula (I) or of the mixture of compounds of formula (I), for example by distillation.

[0037] The embodiments defined above for the first object are of course applicable. In particular, the polyol with the formula G-(OH) n is preferably as defined above and / or the fatty acid is in particular as defined above. A mixture of mono- or polyunsaturated fatty acids in C8 to C24 may be used, and this mixture may be a hydrolysate of an oil, in particular as defined above, or this mixture may be a mixture of mono- or polyunsaturated fatty acids in C8 to C24 from refining processes, for example acid oil, or from the paper industry, for example tallol.

[0038] The process may include a preliminary step of preparing the C8 to C24 monounsaturated or polyunsaturated fatty acid by hydrolysis of a vegetable oil. The vegetable oil is typically soybean, rapeseed, palm, sunflower, flaxseed, camelina, cottonseed, coconut, olive, corn, safflower, jatropha, microalgae oil, or a mixture thereof. The oil may be used oil, such as recovered oil from the food industry, for example, cooking oil. The process thus contributes to the recycling of used oils generally considered waste, which is beneficial for the environment.

[0039] According to a third object, the invention relates to a process for preparing a polyurethane comprising the polymerization of a diisocyanate and at least one compound of formula (I) as defined above.

[0040] The embodiments defined above for the first and second objects are of course applicable.

[0041] For example, polymerization can be carried out from a diisocyanate and a mixture of compounds of formula (II) as defined above where m represents 2 and 3.

[0042] Polymerization can be carried out in the absence of any polyol other than compound of formula (I), or alternatively, using a mixture of at least one compound of formula (I) and at least one other polyol that does not correspond to formula (I), for example, a polyol of fossil origin. For example, polymerization can be carried out from one or more compounds of formula (I) as defined above, other polyol(s) that do not correspond to formula (I), and a diisocyanate, with a mass proportion of compound(s) of formula (I) from 1 to 60% by weight, in particular from 10 to 55% by weight, preferably from 20 to 50% by weight relative to the weight(s) of the other polyol(s).

[0043] Polymerization may involve foaming of the polyurethane. Standard foaming parameters are applicable.

[0044] Polymerization can be carried out in the presence of one or more additives chosen from among catalysts, surfactants, stabilizing agents and flame retardants.

[0045] According to a fourth object, the invention relates to a polyurethane, foamed or non-foamed, which can be obtained by this process.

[0046] The embodiments defined above for other objects are of course applicable. Polyurethane can be a rigid or flexible foam.

[0047] This polyurethane, whether foamed or non-foamed, can be used in various applications, such as a coating, adhesive, sealant, or for preparing parts or components. A preferred application is the preparation of vehicle parts, ideally interior vehicle parts. Examples of vehicles include cars, trucks, buses, tractors, airplanes, and trains.

[0048] Thus, according to a fifth object, the invention relates to an interior vehicle part comprising a polyurethane as defined above.

[0049] The invention is illustrated by the examples and figures that follow.

[0050] Figure 1 represents the residual deformation in % after compression under constant height of the foams prepared in example 2 as a function of their hardness in kPa.

[0051] Figure 2 represents the tear resistance in N / cm of the foams prepared in example 2 as a function of their hardness in kPa.

[0052] Figure 3 represents the residual deformation in % after compression under constant height of the foams prepared in example 4 as a function of their hardness in kPa.

[0053] Figure 4 represents the tear resistance in N / cm of the foams prepared in example 4 as a function of their hardness in kPa.

[0054] Examples

[0055] Example 1: Preparation of compounds of formula (I) with G representing a polyglycerol 3 (PG3)

[0056] Rapeseed oil (ITERG) was hydrolyzed in two stages. In addition, used cooking oil was hydrolyzed in two stages.

[0057] The first step was saponification with potassium hydroxide (KOH), and the second was acidification with hydrochloric or sulfuric acid. 1.1 eq. (based on the saponification value) of aqueous KOH (50 wt. aqueous KOH solution) were added dropwise to the oil. The mixture was heated to 70°C for 2–3 hours. After validation by gas chromatography, the heating was stopped, and the acid (1.1 eq / n) was added. KThe diluted solution was added dropwise. After settling the aqueous phase and washing the organic phase with clear water until the wash water was neutral, the fatty acids were dried. The two hydrolysates obtained had the composition shown in Table 1 below.

[0058] Table 1: Composition of hydrolysates

[0059] Each hydrolysate was esterified in the presence of a polyglycerol 3 (PG3) according to the polyglycerol / fatty acid ratio 1 / 2 at 180°C according to the following reaction scheme: where R and R' are fatty acid residues, identical or different, as defined in Table 1. For example, for the hydrolysate from rapeseed oil which has a high oleic acid content, one of the esterifications that takes place is illustrated in the following diagram:

[0060]

[0061] We thus obtained two mixtures of compounds of formula (I).

[0062] The properties of the prepared mixtures of compounds of formula (I) are given in Table 2. Table 2: Properties of the prepared mixtures of compounds of formula (I)

[0063] Example 2: Preparation of compounds of formula (I) with G representing a polyglycerol 4 (PG4)

[0064] The hydrolysate obtained in example 1 from used cooking oil was esterified in the presence of polyglycerol 4 (PG4) according to the polyglycerol / fatty acid ratio 1 / 3 at 180°C according to the following reaction scheme: where R and R' are fatty acid residues, identical or different, as defined in Table 1 for cooking oil hydrolysate. For example, since cooking oil hydrolysate has a high oleic acid content, one of the esterifications that takes place is illustrated in the following diagram:

[0065] This resulted in a mixture of compounds with formula (I).

[0066] The properties of this mixture of compounds of formula (I) thus prepared are given in Table 3. Table 3: Properties of the mixture of compounds of formula (I) prepared

[0067]

[0068] Example 3: Preparation of a polyurethane according to the invention from a mixture of compounds of formula (I) according to Example 1

[0069] A polymerization was carried out between a diisocyanate (ISO 135 / 161 (BASF)), a polyol (Rokopol 6010 (Rokita)) and the mixture of compounds of formula (I) obtained by esterification of PG3 and hydrolysate from cooking oil obtained in example 1, with a mass proportion of mixture of example 1 / (mixture of example 1 + polyol) of 30%, and in the presence of water, a catalyst (DABCO NE 300 and Polycat 15 (Evonik)) and surfactants (Tegostab B 8715 LF2) and a crosslinker (diethanolamine). The diisocyanate represented 38% by weight of the mixture, the polyol 51.3% by weight of the mixture, the catalysts respectively 0.1 and 1% by weight of the mixture, the surfactant 1% of the mixture, water 1.9% of the mixture and the crosslinker 1% of the mixture.

[0070] Foam formed and expanded freely (free-rise foam). The observed reactivity was similar to that of a comparative foam obtained by polymerization of diisocyanate and polyol, in the absence of compound of formula (I). Reactivity was observed, in particular, by comparing the evolution of foam height as a function of polymerization time, as shown in Table 4 below.

[0071] Table 4: Foam rise height, rise time, and foam rise speed

[0072] As illustrated in Figures 1 and 2, the mechanical properties, in particular the compression set under constant height (measured according to DI N EN ISO 1856, method A) and the tear resistance (measured according to DI N EN ISO 1798, type 1A), of the polyurethane foam according to the invention and that of the comparative foam, were similar at similar hardness (DI N EN ISO 3386-1) at identical density of 60 kg.m- 3 (DIN EN ISO 845)

[0073] Polyurethane foam blocks according to example 2 and with a density of 60 kg / m³ 3 were thus prepared.

[0074] Example 4: Preparation of a polyurethane according to the invention from a mixture of compounds of formula (I) according to Example 2

[0075] A polymerization was carried out between a diisocyanate (ISO 135 / 161 (BASF)), a polyol (Rokopol 6010 (Rokita)) and the mixture of compounds of formula (I) obtained by esterification of PG4 and hydrolysate from cooking oil obtained in example 2, with a mass proportion of mixture of example 2 / (mixture of example 2 + polyol) of 30%, and in the presence of water, a catalyst (DABCO NE 300 and Polycat 15 (Evonik)) and surfactants (Tegostab B 8715 LF2) and a crosslinker (diethanolamine). The diisocyanate represented 38% by weight of the mixture, the polyol 51.3% by weight of the mixture, the catalysts respectively 0.1 and 1% by weight of the mixture, the surfactant 1% of the mixture, water 1.9% of the mixture and the crosslinker 1% of the mixture.

[0076] Foam formed and expanded freely (free-rise foam). The observed reactivity was similar to that of a comparative foam obtained by polymerization of diisocyanate and polyol, in the absence of compound of formula (I). Reactivity was observed, in particular, by comparing the evolution of foam height as a function of polymerization time, as shown in Table 5 below.

[0077] Table 5: Foam rise height, rise time, and foam rise speed

[0078] As illustrated in Figures 3 and 4, the mechanical properties, in particular the compression set under constant height (measured according to DIN EN ISO 1856, method A) and the tear resistance (measured according to DIN EN ISO 1798, type 1A), of the polyurethane foam according to the invention and that of the comparative foam, were similar at similar hardness (DIN EN ISO 3386-1) at identical density of 60 kg.m- 3 (DIN EN ISO 845) Polyurethane foam blocks according to example 2 and with a density of 60 kg / m³ 3 were thus prepared.

Claims

DEMANDS 1. Compound of formula (I): in which: n is an integer from 2 to 3, preferably 2, each R-COO- is independently a mono- or polyunsaturated fatty acid residue at C8 to C24, G represents an alkyl radical of valence n and comprising from 3 to 35, in particular from 4 to 12 carbon atoms, the alkyl radical being substituted by at least two hydroxyl groups and possibly being interrupted by one or more oxygen atoms.

2. Compound according to claim 1, wherein the radical G is a residue of a compound G-(OH) n , n being as defined in claim 1 , and which is pentaerythritol, a polyglycerol, an alditol, a monosaccharide, a disaccharide, an oligosaccharide comprising 3 to 10 oses, a polysaccharide comprising 11 to 30 oses, a mono- or di-saccharide methyl monoether, or an oligomer thereof.

3. Compound according to claim 1 or 2, in which n represents 2 and the radical G has one of the following formulas: in which m represents an integer from 1 to 10, in which p represents 1 or 2, 4. Compound according to any one of claims 1 to 3, wherein the G comprises at least two secondary hydroxyl groups.

5. A compound according to any one of claims 1 to 4, having: a hydroxyl value of 20 to 210 mg KOH / g, preferably 20 to 150 mg KOH / g as measured according to method A of standard NF EN ISO 14900:2023, an acid value less than or equal to 1.0 mg KOH / g, preferably less than or equal to 0.7 mg KOH / g as measured according to standard NF EN ISO 660:2020, and / or a viscosity at 20°C of 400 to 20,000 mPa·s, preferably 400 to 10,000 mPa·s, even more preferably 400 to 5,000 mPa·s as measured with a shear rate between 0.1 and 100 s⁻¹1 .

6. Compound according to any one of claims 1 to 5, obtained by esterification of at least one mono- or polyunsaturated fatty acid in C8 to C24, preferably of an oil hydrolysate comprising several mono- or polyunsaturated fatty acids in C8 to C24 or of a mixture of mono- or polyunsaturated fatty acids in C8 to C24 from a refining process or from the paper industry, with a polyol of formula G-(OH) n in which n and G are such as defined in claim 1.

7. A process for preparing a compound of formula (I) comprising the esterification of at least one C8-C24 mono- or polyunsaturated fatty acid, preferably of an oil hydrolysate comprising several C8-C24 mono- or polyunsaturated fatty acids or of a mixture of C8-C24 mono- or polyunsaturated fatty acids derived from a refining process or paper industry, with a polyol of formula G-(OH) nin which n and G are as defined in claim 1.

8. A process for preparing a polyurethane comprising the polymerization of a diisocyanate, of at least one compound of formula (I) according to any one of claims 1 to 6, and optionally of a polyol which does not correspond to formula (I).

9. A method according to claim 8, comprising foaming the polyurethane.

10. Polyurethane obtained by the process according to any one of claims 8 and 9.

11. Vehicle part, preferably an interior vehicle part, comprising a polyurethane according to claim 10.

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