Cellular urethanes and microcellular elastomers based on 1,5 pentamethylne diisocyanates

Abstract

A cellular polyurethane (PUR) prepared by reacting an isocyanate-terminated (NCO- terminated) pre-polymer with at least one chain extender in presence of one or more surfactants, blowing agents, and / or additives. The NCO-terminated prepolymer is prepared via reaction of pentamethylene diisocyanate (PDI) with a polyol. The cellular PUR has a biobased content of at least 80%.

Description

CELLULAR URETHANES AND MICRO CELLULAR ELASTOMERS BASED ON 1,5 PENTAMETHYLNE DIISOCYANATESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 673,271, filed July 19, 2024, and U.S. Provisional Application No. 63 / 775,160, filed March 20, 2025, the disclosures of both are hereby incorporated in their entirety by reference.TECHNICAL FIELD

[0002] The present description relates to flexible cellular urethanes, including microcellular elastomers, produced from biobased 1,5 -pentamethylene diisocyanate. The flexible cellular urethanes may be flexible foamed urethanes and microcellular elastomers obtained from 1,5-pentamethylene diisocyanate and a polyol (e.g., a biobased polyols).BACKGROUND

[0003] Flexible polyurethane foams, including microcellular elastomers, may be produced from a reaction of one or more isocyanate components with one or more polyol components, and one or more isocyanate-reactive chain extenders, blowing agents, surfactants, and / or other additives.

[0004] Urethane produced from aromatic polyisocyanates may discolor upon exposure to ultraviolet light. To avoid the issue of ultraviolet light induced discoloration, foams have been developed based on aliphatic isocyanates. One such proposal includes the production of foams based on an allophanate derivative of an aliphatic polyisocyanate, through reaction with monohydric alcohol. The resulting foams have low ball rebound.SUMMARY

[0005] In a first embodiment, a cellular polyurethane (PUR) prepared by reacting an isocyanate-terminated (NCO-terminated) pre-polymer with at least one chain extender in thepresence of one or more surfactants, blowing agents, and / or additives is disclosed. The NCO- terminated prepolymer is prepared via reaction of pentamethylene diisocyanate (PDI) with one or more polyols. The cellular PUR has a biobased content of at least 80%.

[0006] The NCO -terminated prepolymer may be produced via reaction of the PDI with the one or more polyols at a 2: 1 molar ratio. The NCO-terminated prepolymer may be produced via reaction of PDI with the one or more polyols at a 2: 1 equivalent ratio.

[0007] The at least one chain extender contains at least one hydroxyl group, primary amine reactive group, secondary amine reactive groups, or a combination thereof.

[0008] The one or more blowing agents may include one or more reactive components that in reaction with an isocyanate generate CO2. One or more additional physical blowing agents may be used in the reaction in addition to the one or more blowing agents including one or more reactive components that in reaction with an isocyanate generate CO2.

[0009] The one or more additives include one or more catalysts that promote urethane forming and / or reaction between water and isocyanate to generate CO2.

[0010] The cellular PUR may have a biobased content of at least 90%. The cellular PUR may have a resilience of at least 30% or at least 50%. The cellular PUR may have a compression set below 10%. The cellular PUR may have a density of less than 0.5 g / mU.

[0011] In a second embodiment, a cellular polyurethane (PUR) prepared by reacting an isocyanate-terminated (NCO-terminated) pre-polymer with at least one chain extender in the presence of one or more physical blowing agents and one or more chemical blowing agents (e.g., water) is disclosed. The one or more physical blowing agents may include methylal and / or Solstice UBA. Different formulations may maintain blowing capacity while reducing the amount of water (e.g., by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, and 100 weight % reduction, or any subrange therein) by substituting an amount of the physical blowing agent to reduce cream time, rise time, and / or tack-free time. The weight ratio of the one or morephysical blowing agents (e.g., in the side A reactants, side B reactants, and / or a third stream) to water may be 0.01, 0.1, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100, or any sub-range therein.DETAILED DESCRIPTION

[0012] Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. Specific functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present embodiments. As those of ordinary skill in the art will understand, various features described with reference to any one of the embodiments may be combined with features illustrated in one or more other embodiments to produce other embodiments. The combinations of features described provide representative embodiments for one or more applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.

[0013] Except in the examples, or where otherwise expressly indicated, all numerical quantities in this description indicating amounts of material or conditions of reaction and / or use are to be understood as modified by the word “about” in describing the broadest scope of the invention. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary: percent, “parts of,” and ratio values are by weight; the description of a group or class of materials as suitable or preferred for a given purpose in connection with the invention implies that mixtures of any two or more of the members of the group or class are equally suitable or preferred; description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description, and does not necessarily preclude chemical interactions among the constituents of a mixture once mixed.

[0014] The first definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation. Unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.

[0015] It must also be noted that, as used in the specification and the appended claims, the singular form “a,” “an,” and “the” comprise plural referents unless the context clearly indicates otherwise. For example, reference to a component in the singular is intended to comprise a plurality of components.

[0016] As used herein, the term “substantially,” “generally,” or “about” means that the amount or value in question may be the specific value designated or some other value in its neighborhood. Generally, the term “about” denoting a certain value is intended to denote a range within ± 5% of the value. As one example, the phrase “about 100” denotes a range of 100 ± 5, i.e. the range from 95 to 105. Generally, when the term “about” is used, it can be expected that similar results or effects according to the invention can be obtained within a range of ± 5% of the indicated value. The term “substantially” may modify a value or relative characteristic disclosed or claimed in the present disclosure. In such instances, “substantially” may signify that the value or relative characteristic it modifies is within ± 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5% or 10% of the value or relative characteristic.

[0017] It should also be appreciated that integer ranges explicitly include all intervening integers. For example, the integer range 1 to 10 explicitly includes 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Similarly, the range 1 to 100 includes 1, 2, 3, 4, . . . . 97, 98, 99, 100. Similarly, when any range is called for, intervening numbers that are increments of the difference between the upper limit and the lower limit divided by 10 can be taken as alternative upper or lower limits. For example, if the range is 1.1 to 2.1 the following numbers 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0 can be selected as lower or upper limits.

[0018] As used herein, the term “and / or” means that either all or only one of the elements of said group may be present. For example, “A and / or B” means “only A, or only B, or both A and B”. In the case of “only A”, the term also covers the possibility that B is absent, i.e., “only A, but not B”.

[0019] It is also to be understood that this invention is not limited to the specific embodiments and methods described below, as specific components and / or conditions may, of course, vary. Furthermore, the terminology used herein is used only for the purpose of describing particular embodiments of the present invention and is not intended to be limiting in any way.

[0020] The term “comprising” is synonymous with “including,” “having,” “containing,” or “characterized by.” These terms are inclusive and open-ended and do not exclude additional, unrecited elements or method steps.

[0021] The phrase “consisting of’ excludes any element, step, or ingredient not specified in the claim. When this phrase appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole.

[0022] The phrase “consisting essentially of’ limits the scope of a claim to the specified materials or steps, plus those that do not materially affect the basic and novel characteristic(s) of the claimed subject matter.

[0023] With respect to the terms “comprising,” “consisting of,” and “consisting essentially of,” where one of these three terms is used herein, the presently disclosed and claimed subject matter can include the use of either of the other two terms.

[0024] The term “one or more” means “at least one” and the term “at least one” means “one or more.” The terms “one or more” and “at least one” include “plurality” as a subset.

[0025] The description of a group or class of materials as suitable for a given purpose in connection with one or more embodiments implies that mixtures of any two or more of the members of the group or class are suitable. Description of constituents in chemical terms refers to the constituents at the time of addition to any combination specified in the description and does not necessarily preclude chemical interactions among constituents of the mixture once mixed. First definition of an acronym or other abbreviation applies to all subsequent uses herein of the same abbreviation and applies mutatis mutandis to normal grammatical variations of the initially defined abbreviation. Unless expressly stated to the contrary, measurement of a property is determined by the same technique as previously or later referenced for the same property.

[0026] Many applications using polyurethane foams would benefit from low energy absorption (e.g., high ball rebound). In addition to this beneficial attribute, it may be desirable to produce cellular polyurethanes, including microcellular elastomers, with high natural biobasedcarbon content. Due to environmental concerns, development of biobased foamed polyurethanes, including microcellular elastomers and other flexible foams, with good physico-chemical properties including high ball rebound (e.g., 60% to 70%) would be desirable.

[0027] One or more embodiments disclosed herein relate to cellular polyurethanes that can be prepared from a biobased pentamethylene diisocyanate (PDI). PDI is a diisocyanate of formula O=C=N-(CH2)5-N=C=O and thus contains five methylene groups and two terminal isocyanato groups. Biobased content may be defined as a fraction of a product that is derived from renewable biological resources, expressed as a percentage of total organic carbon. The amount of biobased content may be measured using ASTM D6866, which uses radiocarbon analysis. The calculation may be represented using the following equation.Biobased Content (%) = (Biobased Carbon / Total Organic Carbon) * 100 (1)

[0028] In one or more embodiments, the polyurethanes (PURs) can be prepared from PDI and a polyol, such as a polyester polyol or a polyether polyol. Depending on the selection of the polyol which can be reacted with PDI, polyurethanes of various properties can be prepared. The preparation of the cellular PUR can involve reacting an NCO-terminated pre-polymer prepared from PDI and at least one polyol, with an isocyanate reactive chain extender, in presence of surfactants, blowing agents, and / or other additives (NCO refers to isocyanate). The cellular PURs of one or more different embodiments can thus present interesting physico-chemical properties and can be used in many different applications.

[0029] In one or more embodiments, a cellular PUR is prepared from an NCO prepolymer produced from biobased monomeric PDI having a biobased content of at least 70% and at least one biobased polyol having a molecular weight of at least 500 g / mol selected from a biobased polyester polyol, a biobased polyether polyol, and a combination thereof, and at least one chain extender in presence of surfactants, blowing agents, and other additives to provide cellular PURs. The cellular PUR can be obtained by first reacting at least one polyol with PDI to form the NCO- terminated pre-polymer which is subsequently reacted with at least one chain extender in presence of surfactants, blowing agents, and / or other additives to provide cellular PURs. Alternatively, cellular PUR can be obtained by reacting PDI with at least one polyol and at and at least one chainextender in presence of surfactants, blowing agents, and / or other additives to provide cellular PURs in single step syntheses.

[0030] In one or more embodiments, a cellular PUR can be prepared from an NCO prepolymers produced from biobased monomeric PDI and at least one polyol, which is subsequently blended with a second isocyanate which are then reacted with at least one chain extender in presence of surfactants, blowing agents, and / or other additives. The second polyol can include aliphatic isocyanates, aromatic isocyanates, isocyanate trimers, and other isocyanate derivatives, including uretdions, and biurets.

[0031] In one or more embodiments, the PDI used for preparing the cellular PURs can be produced by a process as described in US2023416194, which is incorporated herein by reference in its entirety. In one or more embodiments, the PDI can be produced from a cadaverine salt, by a process comprising: (a) providing a phosgene source; (b) providing a solution comprising a cadaverine salt dissolved in an inert solvent in the presence of a tertiary amine base; and (c) subjecting the solution to a liquid-phase phosgenation reaction to convert the cadaverine in the inert solvent to PDI, the phosgenation reaction comprising a step of maintaining the reaction at a temperature range between 100 °C and 120 °C for a sufficient time to achieve a desired threshold yield of PDI, wherein the tertiary amine base is present in an amount sufficient to enable the phosgenation reaction to occur to completion at said temperature range.

[0032] In one or more embodiments, the NCO-prepolymer can result from a reaction between the PDI and at least one of polyol, which can be a polyester polyol, a polyether polyol, or any combination thereof. In one or more embodiments, the polyol (e.g., a polyester polyol and / or a polyether polyol) can be biobased. In one or more embodiments, the polyol can be a biobased polyester polyol and / or a biobased polyether polyol, collectively having a biobased content of at least 90%, or at least 95% or at least 99%, or at least 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, or 99.9%, or about 100%. Alternatively, the polyol can be non-sustainable, or a mixture of a biobased polyol and a non-sustainable polyol.

[0033] In one or more embodiments, the polyester polyol can be selected from a succinate based polyester polyol, an adipate based polyester polyol, a sebacate based polyester polyol, an azelate based polyester polyol, a 1,18-octadecanedioic diacid based polyester polyol, or anycombination thereof. In one or more embodiments, the polyester polyol can be a succinate based polyester polyol, an adipate based polyester polyol, a sebacate based polyester polyol, an azelate based polyester polyol, a 1,18-octadecanedioic diacid based polyester polyol, or any combination thereof, with the polyol being selected from 1,4-Butanediol (1,4-BDO), 1,3 -Propanediol (1,3- PDO) and a mixture thereof. In one or more embodiments, the polyester polyol can be selected from 1,4-BDO-adipate, 1,3-PDO-adipate, 1,4-BDO-Sebacate, 1,3-PDO-sebacate, and any combination thereof. For one or more applications, the polyester polyol can be 1,3-PDO-sebacate. In one or more embodiments, blends of polyester polyols can be used to adjust the polyurethane properties.

[0034] In one or more embodiments, the polyether polyol can be selected from a polytrimethylene ether glycol (PO3G), a polytetramethylene ether glycol (PTMEG or PTMG), a polyethylene glycol, or any combination thereof. In one or more embodiments, the polyether polyol can be a polytrimethylene ether glycol (PO3G). In one or more embodiments, the poly ether polyol can comprise at least one polytetramethylene ether glycol (PTMEG or PTMG). In one or more embodiments, blends of poly ether polyols can be used to adjust the polyurethane properties. For instance, one can use mixtures of PTMEGs of different molecular weights to prepare the NCO- terminated pre-polymer.

[0035] In one or more embodiments, the polyol (e.g., a poly ether polyol and / or a polyester polyol) can have a molecular weight ranging from at least 500 to about 10000 g / mol. The poly ether polyol can have a molecular weight ranging from 500 to about 10000 g / mol, from 500 to about 9000 g / mol, 500 to about 8000 g / mol, 500 to about 7000 g / mol, 500 to about 6000 g / mol, 500 to about 5000 g / mol, 500 to about 40070 g / mol, 500 to about 3000 g / mol, 500 to about 2000 g / mol, or 500 to about 1000 g / mol. In one or more embodiments, the polyether polyol can have a molecular weight ranging from 500 to about 3000 g / mol.

[0036] In one or more embodiments, the NCO-terminated pre-polymer can be produced using a demoisturized polyol. For instance, the polyol can be demoisturized before preparing the NCO-terminated prepolymer to reach a water content below 0.1 wt%, and in one or more embodiments, below 0.06 wt% based on the weight of the polyol.

[0037] The NCO-terminated pre-polymer can be prepared by mixing the PDI and the polyol at the desired ratios and heating the mixture. In one or more embodiments, the reaction advancement can be monitored via NCO% titration. In one or more embodiments, the NCO- terminated pre-polymer can be produced by reacting the PDI and the polyol at 1.1 : 1 to 10: 1 molar ratio. In one or more embodiments, the NCO-terminated pre-polymer can be produced by reacting the PDI and the polyol at a molar ratio of at least 2: 1. In one or more embodiments, the molar ratio of PDI to polyol can be from 1.5: 1 to 4: 1, or from 1.5:1 to 3.5:1, or from 1.5:1 to 3:1, or from 2:1 to 3: 1. In one or more embodiments, the NCO-terminated pre-polymer can be produced by reacting the PDI and the polyol under heating at a temperature ranging from about 50 °C to about 120 °C. In one or more embodiments, the NCO-terminated pre-polymer can be produced by mixing the PDI and the polyol in the absence of any catalyst.

[0038] As mentioned above, and in one or more embodiments, the PDI used to prepare the NCO-terminated pre-polymer is biobased and can have a biobased content of at least 70%. When using a biobased polyol (e.g., a biobased polyether polyol and / or a biobased polyester polyol for preparing the NCO-terminated pre-polymer), it has been found that a very high content of biobased content in the NCO-terminated pre-polymer can be reached, which can be advantageous from a sustainable standpoint.

[0039] In one or more embodiments, the NCO-terminated pre-polymer can reach a biobased content of at least 90%. In one or more embodiments, the NCO-terminated pre-polymer can have a biobased content of from about 90% to about 95%, or from about 90% to about 96%, or from about 90% to about 97%, or from about 90% to about 98%, or from about 90% to about 99%, or from about 90% to about 100%. In one or more embodiments, the biobased content of the NCO-terminated pre-polymer can be about 90%, or about 91%, or about 92%, or about 93%, or about 94%, or about 95%, or about 96%, or about 97%, or about 98%, or about 99%, or about 99.5%, or about 99.6%, or about 99.7%, or about 99.8%, or about 99.9%, or about 100%.

[0040] In one or more embodiments, the cellular PUR can be prepared by reacting an NCO-terminated pre-polymer as described herein with at least one chain extender in presence of surfactants, blowing agents, and / or other additives. Suitable chain extenders can include, but are not limited to, isocyanate reactive alcohols, primary or secondary amines, and combinationthereof. In one or more embodiments, short polyols may be utilized. Non-limiting examples of short polyols include linear and / or branched polyols, including 1,2-propanediol, 1,3-propanediols, 1,4-propanediols, 1,5-propanediol, and combination thereof. In one or more embodiments, the chain extender can include molecules with hydroxyl functionality greater than 2 (e.g., ethylenedinitrilo)tetra-2-propanol commercially as available as Quadrol for BASF and other suppliers). In one or more implementations, the chain extender can include diamines such as aliphatic or ether diamines. In one or more embodiments, deithanolamine can be used as a chain extender. In one or more embodiments, at least one sterically hindered diamine which comprises two primary amino groups, one primary amino group and one secondary amino group, or two secondary amino groups can be used. In one or more embodiments, the sterically hindered diamine used to prepare the elastomer can comprise an aromatic diamine. Non-limiting examples of sterically hindered diamines include Dimethyl thio-toluene diamine (DMTDA), Diethyltoluene diamines such as 3,5-Diethyltoluene-2,4-diamine and 3,5-Diethyltoluene-2,6-diamine or a mixture thereof), or 4,4’-Methylene-bis(2-chloroaniline) (MOCA).

[0041] In one or more embodiments, cellular PUR can be prepared by reacting an NCO- terminated pre-polymer as described herein with at least one chain extender in presence of surfactants, blowing agents, and / or other additives. Silicon surfactants used in foamed polyurethanes can be used.

[0042] In one or more embodiments, cellular PUR can be prepared by reacting an NCO- terminated pre-polymer as described herein with at least one chain extender in presence of surfactants, blowing agents, and / or other additives. The physical or chemical blowing agent may be a low ozone depletion potential (ODP) (e.g., 0.01 to 0.1) and a low global warming potential (GWP) (e.g., less than 1). An additional or alternative blowing agent may be selected from the group consisting of carbon dioxide (CO2); formic acid; organic acids that in reaction with isocyanate produce CO2and / or CO; water that in reaction with isocyanate produce CO2; hydrocarbons; ethers; halogenated ethers; esters; alcohols; aldehydes; ketones; pentafluorobutane; pentafluoro propane; hexafluoropropane; heptafluoropropane; trans- 1.2 di chloroethylene; methyl formate; 2, 2-di chloro- 1,1,1 -trifluoroethane (HCFC-123); 1 -chloro- 1,2, 2, 2-tetrafluoroethane (HCFC-124); 1,1-dichl oro-1 -fluoroethane (HCFC-141b); 1 , 1 , 1 , 2-tetrafluoroethane (HFC 134a); 1-chloro 1 , 1 -difluoroethane (HCFC-142b); 1,1,1,3,3-pentafhiorobutane (HFC-365mfc);;trichlorofluoromethane (CFC-11); dichlorodifluoromethane (CFC-12); dichlorofluoromethane (HCFC-22); 1,1, 1,3, 3, 3 -hexafluoropropane (HFC-236fa); 1,1, 1,2, 3, 3- hexafluoropropane (HFC- 236e); 1,1, 1,2, 3, 3, 3 -heptafluoro propane (HFC-227ea), difluoromethane (HFC-32); 1,1- difluoroethane (HFC-152a); 1,1, 1,3, 3 -pentafluoropropane (HFC-245fa); 1, 3,3,3- tetrafluoropropene (HFO-1234ze); trans-l-chloro-3,3,3- trifluoropropene (HFCO-1233zd(E)) (an example of a physical blowing agent sold under Solstice LBA, available from Honeywell International Inc. of Charlotte, North Carolina); (Z)-l,l,l,4,4,4-Hexafluoro-2-butene (HFO- 1336mzz-Z); butane; isobutane; normal pentane; isopentane; and combinations thereof. Methylal may also be used as a physical blowing agent. Methylal may otherwise be referred to as dimethoxymethane. Methylal may be used as the only blowing agent or in combination with other physical and / or chemical blowing agents. The one or more physical blowing agents may include, for example, one or more physical blowing agents approved by the Environmental Protection Agency (EP A) for use in polyurethane foam systems.

[0043] In one or more embodiments, cellular PUR can be prepared by reacting an NCO- terminated pre-polymer as described herein with at least one chain extender in presence of surfactants, blowing agents, and other additives. A reaction system may also include one or more catalysts, and in one or more embodiments, amine catalysts, such as, but not limited to, primary amine, secondary amine or tertiary amine catalysts which promote reaction between isocyanate and polyols, trimerization reaction of isocyanate, and / or reaction of isocyanates with water to generate CO2. A reaction system may include one or more metal catalysts, including metal salts, metal carboxylic acid salts, organo-metallic catalysts, which typically promote reaction between polyols and isocyanate and trimerization reaction of isocyanates leading to isocyanurate ring formation. In one or more embodiments, catalysts that are stable in contact with HFO blowing agents may be used. Suitable catalysts may include, without limitation, tertiary amine catalysts such as dimethylcyclohexylamine, benzyldimethylamine, N.N.N',N',N'- pentamethyldiethylenetriamine, 2,4,6- tris-(dimethylaminomethyl)-phenol, triethylenediamine, N,N-dimethyl ethanolamine, and combinations thereof; organometallic compounds such as potassium octoate (2-ethylhexanoate), potassium acetate, dibutyltin dilaurate, dibutlytin diacetate, and combinations thereof; and quaternary ammonium salts such as 2-hydroxpropyltrimethylammonium formate; N-substituted triazines such as N,N',N'- dimethylaminopropylhexahydrotriazine; and combinations of thereof.

[0044] In one or more embodiments, the pre-polymer can be heated prior to reaction with the chain extender in presence of silicon surfactants, blowing agents, and / or other additives. Furthermore, additives such as pigments, flame retardants, fillers, colorants, processing aids, plasticizers, stabilizers, antioxidants, mold release agents, to name a few examples, can also be added to the mixture.

[0045] In one or more embodiments, the cellular PUR has varying biobased contents depending on whether biobased polyols are used for the preparation of the NCO-terminated prepolymer. In one or more embodiments, at least the biobased content provided by the PDI is included in the biobased content measurement of the cellular PUR. In one or more embodiments, the biobased content of the PDLbased cellular PUR may be above 90%.

[0046] In one or more embodiments, the PDLbased cellular PURs can be characterized by various physico-chemical properties. These physico-chemical properties may include, without limitation, hardness, resilience, tensile strength, elongation at break, abrasion resistance, and compression set.

[0047] In one or more embodiments, the PDLbased cellular PURs can have a resilience from 5% to 70%.

[0048] In one or more embodiments, the PDLbased cellular PURs can have a resilience above 30% while at the same time providing low compression set below 20%.

[0049] The PDLbased cellular PURs of one or more embodiments can be used in various applications. Non-limiting examples of such applications include footwear production (e.g., shoe insoles and midsoles), liners, metal coatings, seals, rollers for industrial and consumer applications, valves, wheels, tires, agitator blades, rollers, rolls, gaskets, seals, pulleys, bumpers, shock absorbers, bushings, bearings, wear strips, slide plates, machine parts, housings, escalator parts, couplings, fixture blocks, grommets, hammers, striker pads, wood-sorter pads, gears, and sprockets.

[0050] In one or more embodiments, one or more physical blowing agents (e.g., methylal and Solstice LB A) may be used. One or more physical blowing agents may be used to reduce the amount of chemical blowing agent(s) (e.g., water) used in the polyurethane foam system (e.g., microcellular elastomer system), which in turn reduces the amount of PDI based NCO-prepolymer used. The use of one or more physical blowing agents in substitution for a portion of one or more chemical blowing agents may reduce tack-free time, which can reduce the demold time resulting in improved production cycle time. This use of physical blowing agent(s) may produce PDL prepolymer based microcellular elastomers with a relatively low density with an adequate foaming profile and reduced tack-free time. Also, the relatively higher cost of using the physical blowing agent(s) may be offset by reducing the amount of PDI-prepolymer in the polyurethan foam system.

[0051] In one or more embodiments, the blowing capacity may be maintained by reducing the amount of chemical blowing agent by substituting with an amount (e.g., equivalents) of physical blowing agent to reduce cream time, rise time and / or tack-free time. The cream time and / or rise time may be 10 to 90 seconds, including any incremental sub-range therebetween. The tack- free time may be less than 15 minutes, including any incremental sub-range therebetween. The one or more physical blowing agents may comprise 0 to 100 weight % of the total weight of the one or more blowing agents used. In one or more embodiments, the one or more physical blowing agents may comprise any of the following weight %s of the total weight of the one or more blowing agents used or any range of two of the weight %s: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, and 100 weight %. The weight ratio of the one or more physical blowing agents (e.g., in the side A reactants, side B reactants, and / or a third stream) to water may be 0.01, 0.1, 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100, or any sub-range therein.EXAMPLES

[0052] The following examples are illustrative of the invention in its various embodiments and do not limit the scope thereof.

[0053] Preparation of PDI based NCO-prepolymer.

[0054] The NCO-terminated prepolymers based on PDI monomer and polyol was prepared at NCO / OH equivalent ratio of approximately 2 / 1, according to the following procedure: PDI was placed in a 1-L glass reaction kettle equipped with a stirring shaft and continuous flow of nitrogen. The reactor was heated with a temperature-controlled heating mantle. When the temperature of the isocyanate reached 70°C, the polyol was added into the reactor under continuous stirring while maintaining the temperature below 90°C. The reaction was monitored via NCO% titration. After the theoretical NCO% was reached, the reaction was stopped by cooling to room temperature. The prepolymer was stored in a sealed glass bottle under nitrogen at room temperature.

[0055] Table 1 A (above) shows prepolymer synthesis (PO3G 2000 MW polyol with PDI at 1:2.05 equivalent ratio.

[0056] Preparation of Cellular PUR.

[0057] Microcellular elastomers (MCEs) were prepared by the reaction of NCO- prepolymers with the Side B curative blends, which contained chain extender, surfactant, catalyst, and water. In most instances, the MCEs were prepared at an isocyanate index of 105.

[0058] Calculated amount of PDI-prepolymer was pre-heated in an oven at a desired temperature. For Side B curative blend, components were mixed via a planetary mixer (Speed Mixer, FlackTek Inc.) for one minute and preheated in an oven at desired temperature.

[0059] PDI-prepolymer and Side B blend were combined and mixed via agitator equipped with pitched blades for 10 seconds at 3000 RPM. The foaming mixture was transferred into aplastic cup prior to cream time and allowed to free-rise. The foam was cured in a convection oven at desired temperature to cure.

[0060] Table 2A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1-1 through 1-7.

[0061] Table 3A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1-8 through 1-14.

[0062] Table 4A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1-9-2 through 1-9-7.

[0063] Table 5 A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1 -9-6-2, 1-15, 1-15-2, and 1-16.

[0064] Table 6A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1 -9-6-2, 1-9-6-2-T, 1-9-6-2-Q, 1-9-6-2-EC 300, 1-9-6- 2-EDA, and 1 -9-6-2- WI.

[0065] Table 7A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1 -9-6-2, 1-9-6-2-EC 100, 1-9-6-2-EDR, 1-9-6-2-D2000, and 1-9-6-2-T403.

[0066] Table 8 A (above) shows microcellular elastomers based on PDI-PO3G 2000 prepolymers for sample formulations (#s) 1-9-6-2, 1-9-6-2-D2000 / T403-50.50, 1-9-6-2- D2000 / T403-90.10, 1-9-8, 1-9-8-2, and 1-9-9.

[0067] Table 9A (above) shows a microcellular elastomer based on PDI-PO3G 2000 prepolymers for sample formulation (#) 1 -9-6-2.

[0068] Table 10 shows the impact of adding physical blowing agents on foaming activity of a microcellular elastomer system where A is sample formulation (#) 1 -9-6-2. The amounts identified in Table 10 are actual weights in grams used in the synthesis of the microcellular elastomers.

[0069] The use of methylal in formulation L2 resulted in a tack-free time of 13 minutes. The use of Solstice LBA in formulation Ml resulted in a tack-free time of 12 minutes. Formulation Ml also resulted in low density, good resilience, and low compression set. While hardness was relatively lower due to an overall decrease in water and therefore decreased urea linkages, the hardness may be increased by including additional diethanolamine in the formulation and / or other chain extenders, increase in isocyanate index, or addition of fillers.

[0070] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the invention. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These 1attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications.

Claims

AMENDED CLAIMS received by the International Bureau on 26 December 2025 (26.12.2025)1. A method of preparing a flexible, cellular polyurethane (PUR) comprising: reacting an isocyanate-terminated (NCO-terminated) pre-polymer with at least one chain extender in the presence of one or more physical blowing agents and one or more chemical blowing agents, and optionally one or more surfactants and / or additives to form the flexible, cellular PUR, the NCO-terminated prepolymer is prepared via a reaction of pentamethylene diisocyanate (PDI) with one or more polyols, the flexible, cellular PUR has a biobased content of at least 80%, the one or more chemical blowing agents include water, the flexible, cellular PUR has a compression set below 20%.

2. The method of preparing the flexible, cellular PUR of claim 1, wherein the NCO- terminated prepolymer is produced via a reaction of PDI with the one or more polyols at a 2: 1 molar ratio.

3. The method of preparing the flexible, cellular PUR of claim 1, wherein the NCO- terminated prepolymer is produced via a reaction of PDI with the one or more polyols at a 2: 1 equivalent ratio.

4. The method of preparing the flexible, cellular PUR of claim 1, wherein the at least one chain extender contains at least one hydroxyl group, primary amine reactive group, secondary amine reactive groups, or a combination thereof.

5. The method of preparing the flexible, cellular PUR of claim 1 , wherein the one or more blowing agents include one or more reactive components that in reaction with an isocyanate generate CO2.

6. The method of preparing the flexible, cellular PUR of claim 1 , wherein the one or more blowing agents may include one or more physical blowing agents, the one or more physical blowing agents include one or more reactive components that in reaction with an isocyanate generate CO2.

7. The method of preparing the flexible, cellular PUR of claim 1 , wherein the one or more additives include one or more catalysts that promote urethane forming and / or reaction between eater and isocyanate to generate CO2.

8. The method of preparing the flexible, cellular PUR of claim 1 , wherein the flexible, cellular PUR has a biobased content of at least 90%.

9. The method of preparing the flexible, cellular PUR of claim 1 , wherein the flexible, cellular PUR has a resilience of at least 30%.

10. The method of preparing the flexible, cellular PUR of claim 1 , wherein the flexible, cellular PUR has a resilience of at least 50%.

11. The method of preparing the flexible, cellular PUR of claim 1 , wherein the flexible, cellular PUR has a compression set below 20%.

12. The method of preparing the flexible, cellular PUR of claim 1 , wherein the flexible, cellular PUR has a density of less than 0.5 g / mU.

13. A method of preparing a flexible, cellular polyurethane (PUR) comprising: reacting an isocyanate-terminated (NCO-terminated) pre-polymer with at least one chain extender in the presence of one or more physical blowing agents and one or more chemical blowing agents to form the flexible, cellular PUR, the NCO-terminated prepolymer is prepared via a reaction of pentamethylene diisocyanate (PDI) with one or more polyols, the flexible, cellular PUR has a biobased content of at least 80%, the one or more chemical blowing agents include water, the reacting step is completed within 2 to 15 minutes as measured by tack-free time.

14. The method of preparing the flexible, cellular PUR of claim 13, wherein the one or more physical blowing agents includes methylal.

15. The method of preparing the flexible, cellular PUR of claim 13, wherein the one or more physical blowing agents includes trans-1-chloro-3,3,3- trifluoropropene (HFCO-1233zd(E)).

16. The method of preparing the flexible, cellular PUR of claim 13, wherein the reacting step is completed within 3 to 15 minutes as measured by tack-free time.

17. The method of preparing the flexible, cellular PUR of claim 13, wherein the reacting step includes maintaining a blowing capacity while reducing the amount of water with an amount of the one or more physical blowing agents to reduce cream time, rinse time, and / or tack- free time.

18. The method of preparing the flexible, cellular PUR of claim 17, wherein the weight reduction % is in a range of 1 to 100 %.

19. The method of preparing the flexible, cellular PUR of claim 13, wherein a weight ratio of the one or more physical blowing agents to water is 0.01 to 100.

20. The method of preparing the flexible, cellular PUR of claim 13, wherein the one or more physical blowing agents are in side A reactants, side B reactants, and / or a third stream.

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