Viscoelastic elastomeric polyurethane foam, process for its preparation and use thereof

Abstract

The present invention relates to viscoelastic elastomeric polyurethane foams, methods for their preparation, and their use in the manufacture of shaped articles. More particularly, the present invention relates to the field of viscoelastic elastomeric polyurethane foams having improved, unique impact absorbing properties.

Description

Technical Field

[0001] This invention relates to viscoelastic polyurethane foam, its preparation method, and its use in the manufacture of molded articles. More specifically, this invention relates to the field of viscoelastic polyurethane foam with improved and unique impact absorption properties. Background Technology

[0002] In recent years, viscoelastic polyurethane foam (PU foam) has become increasingly important. They are primarily used in the production of interior decorations, mattresses, pillows, or for vibration damping, such as in the foam backing of carpets. These foams are typically characterized by a slow response to stress and have densities ranging from 30 to 100 kg / m³. 3 They are then manufactured into block or sheet-like foams. Regarding porous structures, these foams generally have open-cell structures. Microporous elastomeric polyurethane foams based on high-density and low-density foam types are used in medical, automotive, and aerospace fields. These foams typically exhibit rapid stress response and have a density greater than 50 kg / m³. 3 Low-density foam is made into block foam or molded foam parts, while high-density foam is generally molded to obtain the desired shape in the final product.

[0003] Each of the aforementioned foams possesses unique advantages and properties. Open-cell foams are generally more flexible and softer, with uniform cell size; however, at similar densities, they are not as durable as microporous polyurethane foams. These foam properties are preferably set by selecting starting materials and controlling chemical reactions during processing. By incorporating a foaming agent into the formulation, complete skins can be formed from these foams, resulting in foams with a unique structure where the core density is lower than the surface density. The density distribution formed from the skin to the core brings some interesting properties and is suitable for cushioning materials in furniture, automobiles, etc.

[0004] One possible way to produce viscoelastic PU foam is to use a mixture of a trifunctional polyether polyol with an OH value of 20 mg KOH / g to 100 mg KOH / g and at least one trifunctional polyether polyol with an OH value between 160 mg KOH / g and 250 mg KOH / g and whose chain is essentially composed of propylene oxide units.

[0005] US 2004 / 0254256 describes viscoelastic foam in which the polyol component comprises 30 to 70 parts by weight of a polyether alcohol having a high proportion of ethylene oxide units in the polyether chain. EP 1 240 228 describes the production of viscoelastic foam using polyether alcohol, wherein the high content of ethylene oxide in the polyether chain is at least 50% by weight and the OH value is in the range of 40 mg KOH / g to 50 mg KOH / g.

[0006] DE19936481 describes a sound-absorbing, easily processed moldable flexible PUR foam with a loss factor >0.2 and comprising at least one castor oil polyether alcohol, which is prepared by, for example, anionic polymerization of an alkali metal hydroxide or cationic polymerization of castor oil with an epoxide. Pure castor oil may optionally be added, but in an amount not exceeding 10%. A disadvantage here is that only small amounts of pure castor oil can be processed. Only by using castor oil derivatives (which must be prepared from castor oil in an additional production step) can the proportion of renewable feedstock be significantly increased.

[0007] For ecological reasons, there is a growing market demand for foams made from renewable raw materials. In polyurethane production, renewable raw materials can also serve as alternatives to starting materials for petrochemical production. Foams are typically produced using natural materials containing hydroxyl groups or polyols prepared by adding epoxides to these compounds.

[0008] WO 2007 / 085548 demonstrates how viscoelastic foams with a loss factor >0.15 or resilience <30% can be produced from renewable raw materials, preferably castor oil. This foam exhibits viscoelastic behavior over a wide temperature range. A drawback here is that the foam can only be prepared by a block process. The overall reactivity of the starting materials is insufficient for manufacturing molding foams.

[0009] US 8,426,482 B2 discloses a flexible open-cell PU foam with viscoelastic properties and a largely non-sticky surface, using renewable materials. This foam is produced as flexible molding foam and flexible block foam. The proportion of renewable raw materials in the polyol component is at least 25% by weight of the foam. The foam systems disclosed herein are primarily water-based foaming systems.

[0010] Applications requiring high-performance damping, dynamic shock attenuation, comfort, and durability under various conditions, combined with acceptable or better mechanical properties, are not discussed in the prior art. Furthermore, existing foams are primarily open-cell and / or flexible foams with viscoelastic properties. These foams are particularly characterized by a recovery time of less than 10 seconds and a density of less than 100 kg / m³. 3 And low stiffness, because these foams are typically manufactured with low indices (e.g., 70 to 80), which results in unwanted properties and lower durability, making them suitable for ordinary use, such as mats and mattresses. At higher densities or high indices, existing foams are stiff enough that the desired viscoelasticity is no longer observed.

[0011] Therefore, an object of the present invention is to provide a microporous viscoelastic PU foam based on renewable raw materials, which also possesses acceptable or even excellent characteristics, such as, but not limited to, high shock absorption, dynamic impact damping, and water absorption, combined with excellent mechanical properties, making it suitable for applications requiring high impact performance, comfort, and durability, such as protective equipment. Another object of the present invention is to provide a viscoelastic PU foam that is easy to process using conventional foaming systems and has a wide processing window. Summary of the Invention

[0012] Surprisingly, it has been found that the above-mentioned objectives can be achieved by providing a viscoelastic elastomer PU foam, which is obtained by reacting an isocyanate component comprising at least one isocyanate prepolymer, wherein the isocyanate prepolymer has an NCO content between 10% and 30% by weight, with an isocyanate reactive component comprising a mixture of polyols and chain extenders and / or crosslinking agents in the presence of a foaming agent mixture comprising water and at least one hydrofluorocarbon or at least one hydrofluoroolefin.

[0013] Therefore, in one aspect, the present invention relates to a viscoelastic elastomer polyurethane foam obtained by reacting a reactive mixture, said reactive mixture comprising:

[0014] (A) An isocyanate component comprising at least one isocyanate prepolymer (A1), wherein the NCO content of the isocyanate component is between 10% by weight and 30% by weight, and

[0015] (B) An isocyanate reactive component comprising a mixture of the following substances:

[0016] (a) 60% to 95% by weight of at least one natural oil polyol, which, as determined according to DIN 53240, has an average functionality between 2.0 and 4.0 and an OH value between 100 mg KOH / g and 200 mg KOH / g.

[0017] (b) 0.1% to 10.0% by weight of at least one first polyether polyol, determined according to DIN 53240, having an average functionality between 2.5 and 5.0 and an OH value between 200 mg KOH / g and 450 mg KOH / g, wherein the at least one first polyether polyol is prepared by adding at least one epoxide to an amine.

[0018] (c) 1.0 wt% to 30.0 wt% of at least one second polyether polyol, determined according to DIN 53240, wherein the average functionality of the at least one second polyether polyol is between 2.0 and 4.0 and the OH value is between 20 mg KOH / g and 200 mg KOH / g, wherein the at least one second polyether polyol is prepared by adding ethylene oxide and propylene oxide to at least one H-functional initiator substance, wherein the proportion of ethylene oxide, based on the weight of the second polyether polyol, is between 40 wt% and 95 wt%, and

[0019] (d) 0% to 10.0% by weight of at least one chain extender and / or crosslinking agent, wherein the molecular weight of the at least one chain extender and / or crosslinking agent is between 40 g / mol and 499 g / mol.

[0020] The weight percentage is calculated as the sum of (a), (b), (c), and (d).

[0021] In the presence of the following substances

[0022] (C) A foaming agent mixture comprising water (C1) and (C2) at least one hydrofluorocarbon or (C3) at least one hydrofluoroolefin.

[0023] In another aspect, the present invention relates to a method for preparing the above-mentioned viscoelastic elastomer PU foam.

[0024] In another aspect, the present invention relates to the use of the above-mentioned viscoelastic elastomer PU foam in molded articles.

[0025] In another aspect, the present invention relates to a molded article comprising the above-described viscoelastic elastomer PU foam. Detailed Implementation

[0026] Before describing the compositions and formulations of the present invention, it should be understood that the invention is not limited to the specific compositions and formulations described, as such compositions and formulations can certainly be varied. It should also be understood that the terminology used herein is not intended to be limiting, as the scope of the invention will be limited only by the appended claims.

[0027] As used herein, the terms “comprising, comprises, and comprised of” are synonymous with “including, includes” or “containing, contains”, and are inclusive or open-ended and do not exclude additional, unlisted members, elements, or method steps. It should be understood that, as used herein, the terms “comprising, comprises, and comprised of” include the terms “consisting of, consistes, and consistes of”.

[0028] Furthermore, the terms “first,” “second,” “third,” or “(a),” “(b),” “(c),” “(d),” etc., used in the specification and claims are used to distinguish similar elements and are not necessarily used to describe an order or temporal sequence. It should be understood that such terms are interchangeable where appropriate, and embodiments of the invention described herein can operate in a different order than those described or illustrated herein. Where the terms “first,” “second,” “third,” or “(A),” “(B),” and “(C),” or “(a),” “(b),” “(c),” “(d),” “i,” “ii,” etc., relate to steps of a method, use, or measurement, there is no temporal or time interval continuity between the steps; that is, these steps may be performed simultaneously, or there may be time intervals of seconds, minutes, hours, days, weeks, months, or even years between such steps, unless otherwise indicated in the application set forth above or below.

[0029] The different aspects of the invention are defined in more detail in the following paragraphs. Each aspect so defined may be combined with any one or more other aspects unless explicitly indicated to the contrary. In particular, any feature indicated as preferred or advantageous may be combined with any one or more other features indicated as preferred or advantageous.

[0030] Throughout this specification, references to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the invention. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, features, structures, or characteristics may be combined in any suitable manner, as will be apparent to those skilled in the art from this disclosure. Moreover, while some embodiments described herein include some but not others of features included in other embodiments, as will be understood by those skilled in the art, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the appended claims, any claimed embodiment may be used in any combination.

[0031] Furthermore, the ranges defined throughout the specification also include end values; that is, "the range of 1 to 10" or "between 1 and 10" means that the range includes both 1 and 10. For the avoidance of doubt, the applicant is entitled to an equivalent under applicable law.

[0032] viscoelastic elastomer PU foam

[0033] One aspect of the present invention is Example 1, which relates to a viscoelastic elastomer PU foam obtained by reacting a reactive mixture, the reactive mixture comprising:

[0034] (A) An isocyanate component comprising at least one isocyanate prepolymer (A1), wherein the NCO content of the isocyanate component is between 10% by weight and 30% by weight, and

[0035] (B) An isocyanate reactive component comprising a mixture of the following substances:

[0036] (a) 60% to 95% by weight of at least one natural oil polyol, which, as determined according to DIN 53240, has an average functionality between 2.0 and 4.0 and an OH value between 100 mg KOH / g and 200 mg KOH / g.

[0037] (b) 0.1% to 10.0% by weight of at least one first polyether polyol, determined according to DIN 53240, having an average functionality between 2.5 and 5.0 and an OH value between 200 mg KOH / g and 450 mg KOH / g, wherein the at least one first polyether polyol is prepared by adding at least one epoxide to an amine.

[0038] (c) 1.0 wt% to 30.0 wt% of at least one second polyether polyol, determined according to DIN 53240, wherein the average functionality of the at least one second polyether polyol is between 2.0 and 4.0 and the OH value is between 20 mg KOH / g and 200 mg KOH / g, wherein the at least one second polyether polyol is prepared by adding ethylene oxide and propylene oxide to at least one H-functional initiator substance, wherein the proportion of ethylene oxide, based on the weight of the second polyether polyol, is between 40 wt% and 95 wt%, and

[0039] (d) 0% to 10.0% by weight of at least one chain extender and / or crosslinking agent, wherein the molecular weight of the at least one chain extender and / or crosslinking agent is between 40 g / mol and 499 g / mol.

[0040] The weight percentage is calculated as the sum of (a), (b), (c), and (d).

[0041] In the presence of the following substances

[0042] (C) A foaming agent mixture comprising water (C1) and (C2) at least one hydrofluorocarbon or (C3) at least one hydrofluoroolefin.

[0043] In this paper, OH values ​​were determined using DIN 53240.

[0044] In one embodiment, the viscoelastic elastomer PU foam in Example 1 is a microporous PU foam with viscoelastic characteristics. "Microporous" refers to the morphology of the PU foam, characterized by a discrete pore structure and very small pores, typically with holes in the pore walls. The average pore size is usually less than 200 μm, or even less than 100 μm. In this text, if the density of the PU foam is 90 kg / m³... 3 Up to 450kg / m 3 If the following properties are met: between 10 and 60 seconds (as determined by ASTM D1622); recovery time adjustable between 10 and 60 seconds (as determined by ASTM D3574); water absorption less than 10% by weight after 24 hours (as determined by ASTM D2842); and hysteresis loss up to 96% at 75% deflection and up to 83% at 40% deflection (as determined by ASTM D3574), then it is classified as "microporous PU foam with viscoelastic characteristics".

[0045] Isocyanate component (A)

[0046] In one embodiment, the NCO content of the isocyanate component (A) in Example 1 is between 10 wt% and 30 wt%. In another embodiment, the NCO content in Example 1 is between 12 wt% and 30 wt%, or between 12 wt% and 29 wt%, or between 15 wt% and 29 wt%. In yet another embodiment, the NCO content in Example 1 is between 15 wt% and 28 wt%, or between 18 wt% and 28 wt%. Hereinafter, NCO content may also be referred to as isocyanate content or NCO content %. Measuring and determining NCO content is well known to those skilled in the art, and therefore, the present invention is not limited to the selection or choice of these techniques. For example, ASTM D5155-96 can be used to determine NCO content.

[0047] In one embodiment, the isocyanate component (A) in Example 1 comprises at least one isocyanate prepolymer (A1). A suitable isocyanate prepolymer (A1) in Example 1 is obtained by reacting a monomeric isocyanate with a prepolymer polyol. In one embodiment, the monomeric isocyanate may be an aliphatic or aromatic isocyanate. For example, the monomeric isocyanate may be a diisocyanate of the aforementioned aliphatic or aromatic isocyanates. Representative examples of these preferred diisocyanates can be found in US 4,385,133, US 4,522,975, and US 5,167,899.

[0048] In one embodiment, the aliphatic isocyanate may comprise 6 to 100 carbon atoms linked in a straight-chain or cyclic form and having at least two reactive isocyanate groups. Suitable aliphatic isocyanates may be selected from tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene-1,6-diisocyanate, decamethylene diisocyanate, 1,12-dodecane diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate, 2-methyl-1,5-pentamethylene diisocyanate, cyclobutane-1,3-diisocyanate, 1,2-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, and 1,4-cyclohexane diisocyanate. Esters, 2,4-methylcyclohexane diisocyanate and 2,6-methylcyclohexane diisocyanate, 4,4'-dicyclohexyl diisocyanate and 2,4'-dicyclohexyl diisocyanate, 1,3,5-cyclohexane triisocyanate, methyl isocyanate cyclohexane isocyanate, isocyanate ethylcyclohexane isocyanate, bis(methyl isocyanate)cyclohexane diisocyanate, 4,4'-bis(isocyanate methyl)dicyclohexane and 2,4'-bis(isocyanate methyl)dicyclohexane, isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

[0049] In one embodiment, the aromatic isocyanate may be selected from toluene diisocyanate; diphenylmethane diisocyanate; isophenyl diisocyanate; 1,5-naphthalene diisocyanate; 4-chloro-1,3-isophenyl diisocyanate; 2,4,6-stilbene triisocyanate; 1,3-diisopropylphenylene-2,4-diisocyanate; 1-methyl-3,5-diethylphenylene-2,4-diisocyanate; 1,3,5-triethylphenylene-2,4-diisocyanate; 1,3,5-triisopropylphenylene-2,4-diisocyanate; 3,3' -Diethyl-bisphenyl-4,4'-diisocyanate; 3,5,3',5'-tetraethyldiphenylmethane-4,4'-diisocyanate; 3,5,3',5'-tetraisopropyldiphenylmethane-4,4'-diisocyanate; 1-ethyl-4-ethoxy-phenyl-2,5-diisocyanate; 1,3,5-triethylphenyl-2,4,6-triisocyanate; 1-ethyl-3,5-diisopropylphenyl-2,4,6-triisocyanate; betoluidine diisocyanate and 1,3,5-triisopropylphenyl-2,4,6-triisocyanate.

[0050] In another embodiment, the aromatic isocyanate is selected from toluene diisocyanate; diphenylmethane diisocyanate; isophenyl diisocyanate; 1,5-naphthalene diisocyanate; 4-chloro-1,3-isophenyl diisocyanate; 2,4,6-stilbene triisocyanate; 1,3-diisopropylphenylene-2,4-diisocyanate and 1-methyl-3,5-diethylphenylene-2,4-diisocyanate. In yet another embodiment, it is selected from toluene diisocyanate; diphenylmethane diisocyanate; isophenyl diisocyanate and 1,5-naphthalene diisocyanate. In yet another embodiment, the aromatic isocyanate is diphenylmethane diisocyanate or MDI.

[0051] MDI can be obtained in three different isomer forms: 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI. In one embodiment, as described herein, the monomeric isocyanate in the isocyanate prepolymer (A1) of Example 1 is composed of aromatic isocyanates. In another embodiment, the monomeric isocyanate in the isocyanate prepolymer (A1) of Example 1 is selected from 2,2'-MDI, 2,4'-MDI, and 4,4'-MDI.

[0052] In one embodiment, the prepolymer polyol in the isocyanate prepolymer (A1) of Example 1 may be selected from (but not limited to) natural oil polyols (a), first polyether polyols (b), second polyether polyols (c), and other polyols described herein. Furthermore, polyester polyols and polyether polyols other than natural oil polyols (a), first polyether polyols (b), and second polyether polyols (c) may also be used for this purpose and are well known to those skilled in the art.

[0053] As suitable prepolymer polyols, hydroxyl-functionalized polyethers, sometimes also called polyether polyols, having an average of two or more OH- functional groups per molecule, typically form the product of a polymerization reaction between an organic oxide and an initiator compound containing two or more active hydrogen atoms. The active hydrogen compound initiates ring-opening and oxide addition in the presence of a base catalyst, which continues until the desired molecular weight is obtained. If the initiator has two active hydrogens, a diol is produced. If a trifunctional initiator such as glycerol is used, oxidative addition occurs in three directions, resulting in chain growth and the formation of a triol.

[0054] Hydroxyl-functionalized polyethers can be any type of hydroxyl-functionalized polyether known in the art. Hydroxyl-functionalized polyethers can be unethoxylated or ethoxylated. Additionally, hydroxyl-functionalized polyethers can be short-chain, low-molecular-weight hydroxyl-functionalized polyethers having one or more OH functional groups. Particularly suitable one or more hydroxyl-functionalized polyethers for polyurethanes include, but are not limited to, products obtained by polymerization of epoxides such as ethylene oxide (EO), propylene oxide (PO), butane oxide (BO), or tetrahydrofuran in the presence of an initiator compound having one or more active hydrogen atoms. Suitable initiator compounds containing multiple active hydrogen atoms for obtaining hydroxyl-functionalized polyethers include water, butanediol, ethylene glycol, propylene glycol (PG), diethylene glycol, triethylene glycol, dipropylene glycol, ethanolamine, diethanolamine, triethanolamine, toluenediamine, diethyltoluenediamine, phenyldiamine, diphenylmethanediamine, ethylenediamine, cyclohexanediamine, cyclohexanediethanolamine, resorcinol, bisphenol A, glycerol, trimethylolpropane, 1,2,6-hexanetriol, pentaerythritol, and combinations thereof.

[0055] Other hydroxyl-functionalized polyethers or a variety of polyethers, suitable prepolymer polyols, include polyether glycols and triols, such as polyoxypropylene glycol and triol, and poly(ethylene oxide-propylene oxide) glycol and triol, which are obtained by simultaneously or sequentially adding ethylene oxide and propylene oxide to a bifunctional or trifunctional initiator. Copolymers with an ethylene oxide content ranging from about 5% to about 90% by weight of the polyether polyol component may also be used, wherein the polyether polyol can be a block copolymer, a random / block copolymer, or a random copolymer. Other suitable hydroxyl-functionalized polyethers include polytetramethylene ether glycol obtained by tetrahydrofuran polymerization.

[0056] Particularly suitable hydroxyl-functionalized polyethers or polyethers include those based on fully anisotropic (or random) EO (ethylene oxide) or PO (propylene oxide) structures, or those having mixed but uniform EO and PO blocks, such as blocks including EO and blocks including PO. As another suitable example, hydroxyl-functionalized polyethers can have mixed and uniform blocks of EO and PO, such as blocks including all EO or PO and blocks including random EO and PO. Additionally, in some instances, hydroxyl-functionalized polyethers can be mixed or random copolymers of EO and PO, end-capped with EO or PO. A particularly suitable hydroxyl-functionalized polyether includes polyether triols having ethylene oxide terminal groups.

[0057] In some of these embodiments, the weight-average molecular weight (Mw) of the hydroxyl-functionalized polyethers (one or more) used to form the isocyanate-terminated prepolymers disclosed in this subject matter is in the range of 60 to 10,000, such as 180 to 6,500 g / mol, as measured by gel permeation chromatography (GPC) or nuclear magnetic resonance (NMR), which has been previously calibrated using a calibration curve based on monodisperse polystyrene standards.

[0058] In another embodiment, the isocyanate component (A) of Example 1 further comprises another isocyanate prepolymer (A1') different from the isocyanate prepolymer (A1). The isocyanate prepolymer (A1') can be obtained as any monomer and as a reaction product of polymerized isocyanate with a suitable polyol. The term "polymerization" refers to the polymerization grade of aliphatic and / or aromatic isocyanates, which comprise different oligomers and homologs. Further, the suitable polyol may be selected from those described herein.

[0059] In one embodiment, the isocyanate component (A) in Example 1 further comprises at least one selected from the following substances: (A2) carbodiimide-modified isocyanate, (A3) polymeric methylene diphenyl diisocyanate, (A4) isocyanate comprising biuret and / or isocyanurate groups, and (A5) 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and / or 4,4'-diphenylmethane diisocyanate.

[0060] In another embodiment, the isocyanate component (A) comprises at least one isocyanate prepolymer (A1) and a mixture of at least one of the following: (A2) carbodiimide-modified isocyanate, (A3) polymeric methylene diphenyl diisocyanate, (A4) isocyanate comprising biuret and / or isocyanurate groups, and (A5) 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and / or 4,4'-diphenylmethane diisocyanate.

[0061] In another embodiment, the isocyanate component (A) consists of a mixture of at least one isocyanate prepolymer (A1) and at least one of the following: (A2) carbodiimide-modified isocyanate, (A3) polymeric methylene diphenyl diisocyanate, (A4) isocyanate comprising biuret and / or isocyanurate groups, and (A5) 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and / or 4,4'-diphenylmethane diisocyanate.

[0062] In one embodiment, the isocyanate component (A) in Example 1 is a mixture of (A1) isocyanate prepolymer and (A2) carbodiimide-modified isocyanate. In another embodiment, the carbodiimide-modified isocyanate (A2) comprises carbodiimide-modified 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and / or 4,4'-diphenylmethane diisocyanate. In yet another embodiment, the carbodiimide-modified isocyanate (A2) is carbodiimide-modified 4,4'-MDI.

[0063] In one embodiment, the amount of isocyanate prepolymer (A1) in Example 1 is between 10% by weight and 90% by weight, based on the total weight of isocyanate component (A). In another embodiment, the amount of isocyanate prepolymer (A1) in Example 1 is between 20% by weight and 90% by weight, or between 20% by weight and 80% by weight, or between 30% by weight and 80% by weight. In yet another embodiment, the amount of isocyanate prepolymer (A1) in Example 1 is between 30% by weight and 70% by weight, or between 40% by weight and 70% by weight, or between 40% by weight and 60% by weight.

[0064] In one embodiment, the isocyanate component (A) in Example 1 further comprises a blowing agent different from the blowing agent mixture (C). Suitable blowing agents in the isocyanate component (A) include physical blowing agents selected from hydrocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluorocarbons, hydrochlorofluoroolefins, fluorocarbons, dialkyl ethers, cycloalkylene ethers and ketones, and fluorinated ethers.

[0065] Isocyanate reactive component (B)

[0066] The isocyanate reactive component (B) in Example 1 comprises a mixture of the following substances:

[0067] (a) 60% to 95% by weight of at least one natural oil polyol, wherein the average functionality of the at least one natural oil polyol is between 2.0 and 4.0 and the OH value is between 30 mg KOH / g and 600 mg KOH / g.

[0068] (b) 0.1% to 10.0% by weight of at least one first polyether polyol, wherein the average functionality of the at least one first polyether polyol is between 2.5 and 5.0 and the OH value is between 200 mg KOH / g and 450 mg KOH / g, wherein the at least one first polyether polyol is prepared by adding at least one epoxide to an amine.

[0069] (c) 1.0% to 30.0% by weight of at least one second polyether polyol, wherein the average functionality of the at least one second polyether polyol is between 2.0 and 4.0 and the OH value is between 20 mg KOH / g and 200 mg KOH / g, wherein the at least one second polyether polyol is prepared by adding ethylene oxide and propylene oxide to at least one H-functional initiator substance, wherein the proportion of ethylene oxide, based on the weight of the second polyether polyol, is between 40% and 95% by weight.

[0070] (d) 0% to 10.0% by weight of at least one chain extender and / or crosslinking agent, wherein the molecular weight of the at least one chain extender and / or crosslinking agent is between 40 g / mol and 499 g / mol.

[0071] The weight percentage is the sum of (a), (b), (c) and (d).

[0072] Natural oil polyols (a)

[0073] The suitable natural oil polyol (a) in Example 1 has an average functionality between 2.0 and 4.0 and an OH value between 30 mg KOH / g and 600 mg KOH / g. In one embodiment, the natural oil polyol (a) in Example 1 has an average functionality between 2.0 and 3.8, or between 2.0 and 3.6, or between 2.0 and 3.4. In another embodiment, the natural oil polyol (a) in Example 1 has an average functionality between 2.0 and 3.2, or between 2.0 and 3.0, or between 2.2 and 3.0. In yet another embodiment, the natural oil polyol (a) in Example 1 has an average functionality between 2.5 and 3.0, or between 2.5 and 2.9.

[0074] In one embodiment, the OH value of the natural oil polyol (a) in Example 1 is between 30 mg KOH / g and 600 mg KOH / g, or between 50 mg KOH / g and 300 mg KOH / g, or between 100 mg KOH / g and 200 mg KOH / g, or between 110 mg KOH / g and 190 mg KOH / g, or between 120 mg KOH / g and 190 mg KOH / g. In another embodiment, the OH value of the natural oil polyol (a) in Example 1 is between 120 mg KOH / g and 180 mg KOH / g, or between 130 mg KOH / g and 180 mg KOH / g, or between 130 mg KOH / g and 170 mg KOH / g. In another embodiment, the OH value of the natural oil polyol (a) in Example 1 is between 140 mg KOH / g and 170 mg KOH / g, or between 150 mg KOH / g and 170 mg KOH / g.

[0075] In one embodiment, the natural oil polyol (a) is selected from castor oil, polyhydroxy fatty acids, ricinoleic acid, hydroxy-modified oils such as grape seed oil, black cumin oil, pumpkin seed oil, borage seed oil, soybean oil, wheat germ oil, rapeseed oil, sunflower oil, peanut oil, almond oil, pistachio oil, olive oil, macadamia nut oil, avocado oil, sea buckthorn oil, sesame oil, sesame seed oil, safflower oil, walnut oil, hydroxy-modified fatty acids and myristone acid-based fatty acid esters, palmitoleic acid, oleic acid, octadecenoic acid, phellandrene acid, cod oleic acid, erucic acid, nervonic acid, linoleic acid, α-linolenic acid and γ-linolenic acid, octadecanoic acid, arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid and docosahexaenoic acid.

[0076] In another embodiment, the natural oil polyol (a) in Example 1 is castor oil and / or hydrogenated castor oil. These natural oils and fats can be modified by addition reactions with alkylene groups. Here, the alkylene oxide is preferably added in an amount such that the OH value of the addition product is within the range described herein. The addition reaction with the alkylene oxide can preferably be carried out using a DMC catalyst.

[0077] The suitable amount of natural oil polyol (a) in Example 1, calculated as a sum of (a), (b), (c), and (d) as described herein, is in the range of 65% to 95% by weight. In one embodiment, the natural oil polyol (a) in Example 1 is present in an amount between 65% and 90% by weight, or between 70% and 90% by weight, or between 72% and 90% by weight, or between 75% and 90% by weight. In another embodiment, the natural oil polyol (a) in Example 1 is present in an amount between 75% and 88% by weight, or between 78% and 88% by weight, or between 80% and 88% by weight, or between 80% and 85% by weight.

[0078] First polyether polyol (b)

[0079] In one embodiment, the average functionality of the first polyether polyol (b) in Example 1 is between 2.5 and 5.0, and the OH value is between 200 mg KOH / g and 450 mg KOH / g. In one embodiment, the average functionality of the first polyether polyol (b) in Example 1 is between 2.7 and 5.0, or between 2.7 and 4.9, or between 2.9 and 4.9. In another embodiment, the average functionality of the first polyether polyol (b) in Example 1 is between 3.0 and 4.9, or between 3.0 and 4.8, or between 3.2 and 4.8. In yet another embodiment, the average functionality of the first polyether polyol (b) in Example 1 is between 3.2 and 4.5, or between 3.5 and 4.5, or between 3.5 and 4.3, or between 3.6 and 4.3, or between 3.8 and 4.2.

[0080] In one embodiment, the OH value of the first polyether polyol (b) in Example 1 is between 210 mg KOH / g and 450 mg KOH / g, or between 210 mg KOH / g and 420 mg KOH / g, or between 220 mg KOH / g and 420 mg KOH / g. In another embodiment, the OH value of the first polyether polyol (b) in Example 1 is between 220 mg KOH / g and 400 mg KOH / g, or between 230 mg KOH / g and 400 mg KOH / g, or between 230 mg KOH / g and 380 mg KOH / g. In yet another embodiment, the OH value of the first polyether polyol (b) in Example 1 is between 250 mg KOH / g and 380 mg KOH / g, or between 250 mg KOH / g and 350 mg KOH / g, or between 270 mg KOH / g and 320 mg KOH / g.

[0081] In one embodiment, the first polyether polyol (a) of Example 1 is prepared by adding at least one epoxide to an amine. Suitable amines for the first polyether polyol (a) of Example 1 may be selected from diamino-methyldipropylamine, diamino-methyldiethylamine, diamino-methyl-ethylpropylamine, phenylenediamine, toluenediamine, diaminodiphenylmethane, ethanolamine, methylethanolamine, ethylethanolamine, diethanolamine, methyldiethanolamine, ethyldiethanolamine, triethanolamine, and isomers thereof.

[0082] In one embodiment, the isomer of the amine used in the first polyether polyol (a) of Example 1 may be selected from 3,3'-diamino-N-methyldipropylamine, 2,2'-diamino-N-methyldiethylamine, 2,3-diamino-N-methyl-ethylpropylamine, 1,2-phenylenediamine, 1,3-phenylenediamine, 1,4-phenylenediamine, 2,3-toluenediamine, 2,4-toluenediamine, 3,4-toluenediamine, 2,6-toluenediamine, 4,4'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 2,2'-diaminodiphenylmethane, ethanolamine, N-methylethanolamine, N-ethylethanolamine, diethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, and triethanolamine.

[0083] In another embodiment, the amine in the first polyether polyol (b) of Example 1 is based on an aromatic amine, such as toluene diamine (TDA), phenylenediamine, diaminodiphenylmethane, and its isomers. When using TDA, the o-isomer, also known as ortho-TDA, is particularly preferred.

[0084] In Example 1, a suitable epoxide in the first polyether polyol (b) can be selected from ethylene oxide, propylene oxide, butane oxide, styrene oxide, its isomers, and mixtures. In one embodiment, the epoxide in the first polyether polyol (b) of Example 1 can be propylene oxide. Ethylene oxide can also be used simultaneously, particularly when aromatic amines are used. Then, the amount of ethylene oxide used is preferably in the range of 2% to 15% by weight, based on the total weight of the first polyether polyol (a).

[0085] In one embodiment, the first polyether polyol (a) of Example 1 is present in an amount between 0.1 wt% and 9.0 wt%, based on the sum of (a), (b), (c), and (d). In another embodiment, the first polyether polyol (a) of Example 1 is present in an amount between 0.5 wt% and 9.0 wt%, or between 0.5 wt% and 8.0 wt%, or between 0.5 wt% and 7.0 wt%. In yet another embodiment, the first polyether polyol (a) of Example 1 is present in an amount between 0.5 wt% and 6.0 wt%, or between 0.5 wt% and 5.0 wt%, or between 1.0 wt% and 5.0 wt%. In yet another embodiment, the first polyether polyol (a) of Example 1 is present in an amount between 1.0 wt% and 4.0 wt%, or between 1.0 wt% and 3.5 wt%.

[0086] Second polyether polyol (c)

[0087] In one embodiment, the average functionality of the second polyether polyol (c) in Example 1 is between 2.2 and 4.0, or between 2.2 and 3.8, or between 2.4 and 3.8. In another embodiment, the average functionality of the second polyether polyol (c) in Example 1 is between 2.4 and 3.6, or between 2.5 and 3.6, or between 2.5 and 3.5. In yet another embodiment, the average functionality of the second polyether polyol (c) in Example 1 is between 2.8 and 3.5, or between 2.8 and 3.3, or between 2.9 and 3.1.

[0088] In one embodiment, the OH value of the second polyether polyol (c) in Example 1 is between 30 mg KOH / g and 100 mg KOH / g, or between 30 mg KOH / g and 90 mg KOH / g, or between 40 mg KOH / g and 90 mg KOH / g. In another embodiment, the OH value of the second polyether polyol (c) in Example 1 is between 40 mg KOH / g and 80 mg KOH / g, or between 40 mg KOH / g and 70 mg KOH / g, or between 40 mg KOH / g and 60 mg KOH / g. In yet another embodiment, the OH value of the second polyether polyol (c) in Example 1 is between 40 mg KOH / g and 55 mg KOH / g.

[0089] In one embodiment, the second polyether polyol (c) of Example 1 is prepared by adding ethylene oxide and propylene oxide to at least one H-functional initiator substance, wherein the proportion of ethylene oxide, based on the weight of the second polyether polyol (c), is between 40% by weight and 95% by weight. In another embodiment, the proportion of ethylene oxide in the second polyether polyol (c) of Example 1 is between 60% by weight and 85% by weight, or between 70% by weight and 85% by weight. Examples of H-functional initiator substances include sugars, sugar alcohols such as glucose, mannitol, sucrose, pentaerythritol, sorbitol; polyphenols, methylphenolic resins such as oligomeric condensation products formed from phenol and formaldehyde, trimethylolpropane, glycerol, glycols such as ethylene glycol, propylene glycol and their condensation products such as polyethylene glycol and polypropylene glycol, such as diethylene glycol, triethylene glycol, dipropylene glycol and water or combinations thereof.

[0090] In one embodiment, the H-functional initiator substance in the second polyether polyol (c) of Example 1 comprises glycerol, glycols such as ethylene glycol, propylene glycol and their condensation products such as polyethylene glycol and polypropylene glycol, for example diethylene glycol, triethylene glycol, dipropylene glycol and water or combinations thereof.

[0091] In another embodiment, the second polyether polyol (c) in Example 1 is a glycerol-initiated polyoxypropylene-polyoxyethylene polyol with an average functionality between 2.9 and 3.1 and an OH value between 40 mg KOH / g and 55 mg KOH / g. Based on the weight of the second polyether polyol (c), EO accounts for 75% by weight and PO accounts for 25% by weight.

[0092] In one embodiment, the second polyether polyol (c) of Example 1 is present in an amount between 1.0 wt% and 20.0 wt%, based on the sum of (a), (b), (c), and (d). In another embodiment, the second polyether polyol (c) of Example 1 is present in an amount between 2.0 wt% and 18.0 wt%, or between 5.0 wt% and 18.0 wt%, or between 5.0 wt% and 15.0 wt%. In yet another embodiment, the second polyether polyol (c) of Example 1 is present in an amount between 8.0 wt% and 15.0 wt%, or between 10.0 wt% and 15.0 wt%.

[0093] Chain extenders and / or crosslinking agents (d)

[0094] Suitable chain extenders and / or crosslinking agents (d) have molecular weights between 40 g / mol and 499 g / mol. These compounds are typically present in the isocyanate reactive component (B) to modify foam hardness, increase stability, and reduce shrinkage. In one embodiment, the chain extender and / or crosslinking agent (d) in Example 1 may be selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,2-dihydroxycyclohexane, 1,3-dihydroxycyclohexane, 1,4-dihydroxycyclohexane, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, bis(2-hydroxy-ethyl)hydroquinone, dipropylene glycol, glycerol, diethanolamine, and triethanolamine.

[0095] In another embodiment, the chain extender and / or crosslinking agent (d) in Example 1 may be selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,4-butanediol, 1,6-hexanediol, bis(2-hydroxy-ethyl)hydroquinone, dipropylene glycol, glycerol, diethanolamine, and triethanolamine.

[0096] In another embodiment, the chain extender and / or crosslinking agent (d) in Example 1 is triethanolamine. If desired, the chain extender and / or crosslinking agent (d) in Example 1 may be present in an amount between 0.1 wt% and 10.0 wt%, based on the sum of (a), (b), (c), and (d). In one embodiment, the chain extender and / or crosslinking agent (d) in Example 1 may be present in an amount between 0.1 wt% and 10.0 wt%, or between 0.1 wt% and 8.0 wt%, or between 0.1 wt% and 5.0 wt%. In another embodiment, the chain extender and / or crosslinking agent (d) in Example 1 may be present in an amount between 0.1 wt% and 4.0 wt%, or between 0.1 wt% and 3.0 wt%, or between 0.1 wt% and 2.0 wt%. In yet another embodiment, the chain extender and / or crosslinking agent (d) in Example 1 may be present in an amount between 0.5 wt% and 2.0 wt%.

[0097] Although the isocyanate reactive component (B) in Example 1 includes (a), (b), (c), and (d), it may include other components that are reactive with isocyanates. These components may be polyols and / or diols different from (a), (b), (c), and (d). For example, the average functionality and OH value of polyether polyols and polyester polyols may differ from those of natural oil polyol (a), first polyether polyol (b), and second polyether polyol (c).

[0098] In one embodiment, the isocyanate reactive component (B) in Example 1 further comprises a polymeric polyol (e). These polymeric polyols have a nominal functionality ranging from 2.0 to 8.0 and an OH value ranging from 10 mg KOH / g to 1000 mg KOH / g.

[0099] Polymer polyols are stable dispersions of polymer particles within polyols, thus they do not readily settle or float. Polymer particles are chemically grafted onto polyols and act as enhanced reinforcing fillers, allowing the polymer composition to be tailored to provide desired properties. Polymer polyols have very low moisture content, thus avoiding the problems associated with wet fillers. Compared to inorganic fillers such as clay or calcium carbonate, the polymer density in polymer polyols is typically lower.

[0100] Suitable polymeric polyols are selected from styrene-acrylonitrile (SAN) polymeric polyols, polyurea suspension (PHD) polymeric modified polyols, and polyisocyanate addition polyols (PIPA) polymeric modified polyols.

[0101] SAN polymeric polyols are known in the art and disclosed in Ionescu, *Chemistry and Technology of Polyols and Polyurethanes*, 2nd edition, 2016, Smithers Rapra Technology Ltd. In SAN polymeric polyols, the carrier polyol is a polyol in which an olefinically unsaturated monomer is polymerized in situ, while the macromonomer is a polymeric compound having at least one olefinically unsaturated group in its molecule and added to the carrier polyol prior to the polymerization of the olefinically unsaturated monomer. For example, the uses and functions of these macromonomers are described in US 4,454,255, US 4,458,038, and US 4,460,715. SAN polymeric polyols are typically prepared by free radical polymerization of olefinically unsaturated monomers (preferably acrylonitrile and styrene) in a polyether polyol or polyester polyol (commonly referred to as the carrier polyol) as a continuous phase. These polymeric polyols are prepared by in-situ polymerization of acrylonitrile, styrene, or a mixture of styrene and acrylonitrile, for example, at a weight ratio of 90:10 to 10:90 (styrene:acrylonitrile), using methods similar to those described in DE 1111394, DE 1222669, DE 1152536, and DE 1152537. Moderators, also known as chain transfer agents, can also be used in the preparation of SAN polymeric polyols; for example, the uses and functions of these moderators are described in US 4,689,354, EP 0 365986, EP 0 510 533, EP 0 640 633, EP 008 444, and EP 0731 118.

[0102] PHD polymer-modified polyols are typically prepared by in-situ polymerization of a mixture of isocyanates with diamines and / or hydrazines in a polyol (e.g., a polyether polyol). For example, methods for preparing PHD polymer-modified polyols are described in US 4,089,835 and US 4,260,530.

[0103] PIPA polymer-modified polyols are typically prepared by in-situ polymerization of isocyanate mixtures with diols and / or diolamines in the polyol. For example, methods for preparing PIPA polymer-modified polyols are described in US 4,293,470 and US 4,374,209.

[0104] When used, a suitable amount of polymeric polyol (e) from the isocyanate reactive component (B) of Example 1 may be added, as is known to those skilled in the art. For example, the polymeric polyol (e) from the isocyanate reactive component (B) of Example 1 may be present in an amount between 0.1% by weight and 10% by weight, based on the total weight of the isocyanate reactive component (B).

[0105] Foaming agent mixture (C)

[0106] In one embodiment, the blowing agent mixture (C) in Example 1 comprises water (C1) and at least one hydrofluorocarbon (C2) or (C3) at least one hydrofluoroolefin. In one embodiment, the blowing agent mixture (C) in Example 1 comprises water (C1) and at least one hydrofluorocarbon (C2). In another embodiment, the blowing agent mixture (C) in Example 1 comprises water (C1) and at least one hydrofluoroolefin (C3).

[0107] In one embodiment, the blowing agent mixture (C) in Example 1 does not contain any other blowing agents besides those described herein. In another embodiment, a mixture of hydrofluorocarbons (C2) or hydrofluoroolefins (C3) as described herein may also be used with water (C1).

[0108] The suitable hydrofluorocarbon (C2) in Example 1 can be selected from 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, trifluoromethane, heptafluoropropane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2,2-pentafluoropropane, 1,1,1,3-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluoro-n-butane, 1,1,1,4,4,4-hexafluoro-n-butane and 1,1,1,2,3,3,3-heptafluoropropane.

[0109] In one embodiment, the hydrofluorocarbon (C2) in Example 1 may be selected from 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, trifluoromethane, heptafluoropropane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2,2-pentafluoropropane, 1,1,1,3-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, and 1,1,3,3,3-pentafluoropropane. In another embodiment, the hydrofluorocarbon (C2) in Example 1 may be selected from 1,1,1,2,2-pentafluoropropane, 1,1,1,3-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, and 1,1,3,3,3-pentafluoropropane. In yet another embodiment, the hydrofluorocarbon (C2) in Example 1 is 1,1,3,3,3-pentafluoropropane, commonly also referred to as HFC 245fa.

[0110] The suitable hydrofluoroolefin (C3) in Example 1 can be selected from cis or trans forms of 1,1,1,3-tetrafluoropropene, 1,1,1-trifluoro-2-chloropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,2,3-pentafluoropropene, 1,1,1,4,4,4-hexafluoro-2-butene, 1-bromopentafluoropropene, 2-bromopentafluoropropene, 3-bromopentafluoropropene, 1,1,2,3,3,4,4-heptafluoro-1-butene, 3 3,4,4,5,5,5-Hepenofluoro-1-pentene, 1-bromo-2,3,3,3-tetrafluoropropene, 2-bromo-1,3,3,3-tetrafluoropropene, 3-bromo-1,1,3,3-tetrafluoropropene, 2-bromo-3,3,3-trifluoropropene, E-1-bromo-3,3,3-trifluoropropene, 3,3,3-trifluoro-2-(trifluoromethyl)propene, 1-chloro-3,3,3-trifluoropropene, 2-chloro-3,3,3-trifluoropropene, and 1,1,1-trifluoro-2-butene.

[0111] In one embodiment, the hydrofluoroolefin (C3) in Example 1 may be selected from cis or trans forms of 1,1,1,3-tetrafluoropropene, 1,1,1-trifluoro-2-chloropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,2,3-pentafluoropropene, 1,1,1,4,4,4-hexafluoro-2-butene, 1-bromopentafluoropropene, 2-bromopentafluoropropene, 3-bromopentafluoropropene, 1,1,2,3,3,4,4-heptafluoro-1-butene, 3,3,4,4,5,5,5-heptafluoro-1-pentene, and 1-bromo-2,3,3,3-tetrafluoropropene. In another embodiment, the hydrofluoroolefin (C3) in Example 1 may be selected from cis or trans forms of 1,1,1,3-tetrafluoropropylene, 1,1,1-trifluoro-2-chloropropene, 1-chloro-3,3,3-trifluoropropene, 1,1,1,2,3-pentafluoropropene, 1,1,1,4,4,4-hexafluoro-2-butene, and 1-bromopentafluoropropene. In yet another embodiment, the hydrofluoroolefin (C3) in Example 1 is cis or trans forms of 1,1,1,4,4,4-hexafluoro-2-butene.

[0112] In one embodiment, the blowing agent mixture (C) in Example 1 comprises water (C1) and 1,1,3,3,3-pentafluoropropane (C2). In another embodiment, the blowing agent mixture (C) in Example 1 comprises water (C1) and cis-1,1,1,4,4,4-hexafluoro-2-butene (C3).

[0113] In one embodiment, the amount of the foaming agent mixture (C) in Example 1 is between 0.1% by weight and 10% by weight, based on the total weight of the isocyanate reactive components.

[0114] In one embodiment, the reactive mixture further comprises at least one selected from a catalyst (D), a surfactant (E), and an additive (F).

[0115] Catalyst (D)

[0116] In exothermic reactions between isocyanate component (A) and isocyanate reactive component (B), the catalyst is typically not consumed. More specifically, in exothermic reactions, the catalyst typically participates but is not consumed. The catalyst may comprise any suitable catalyst or mixture of catalysts known in the art. Examples of suitable catalysts include, but are not limited to, gelling catalysts, such as amine catalysts in dipropylene glycol; foaming catalysts, such as bis(dimethylaminoethyl) ether in dipropylene glycol; and metal catalysts, such as tin, bismuth, lead, etc.

[0117] The exemplary catalyst (D) comprises amidines such as 2,3-dimethyl-3,4,5,6-tetrahydropyrimidine, tertiary amines such as triethylamine, tributylamine, dimethylbenzylamine, N-methylmorpholine, N-ethylmorpholine, N-cyclohexylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethylbutyldiamine, N,N,N',N'-tetramethylhexanediamine, pentamethyldiethylenetriamine, bis(dimethylaminoethyl) ether, bis(dimethylaminopropyl)urea, dimethylpiperazine, 1,2-dimethylimidazole, and 1-azabicyclo[3.3.0]octane. In one embodiment, the catalyst (D) is selected from 1,4-diazabicyclo[2.2.2]octane and alkanolamine compounds such as triethanolamine, triisopropanolamine, N-methyl-diethanolamine, N-ethyl-diethanolamine, and dimethylethanolamine.

[0118] Other possibilities for catalyst (D) are organometallic compounds (i.e., organometallic compounds), such as organotin compounds like tin(II) salts of organic carboxylic acids, such as tin(II) acetate, tin(II) octoate, tin(II) ethylhexanoate, and tin(II) laurate and dialkyltin(IV) salts of organic carboxylic acids, such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate, and dioctyltin diacetate, and bismuth carboxylic acids such as bismuth(III) neodecanoate, bismuth 2-ethylhexanoate, and bismuth octoate, or mixtures thereof.

[0119] Other catalysts (D) include amine catalysts, which are a class of organic compounds derived from ammonia (NH3) by substituting one or more hydrogen atoms with alkyl groups (molecular chains containing carbon and hydrogen) – for example, dimethylcyclohexylamine [(CH3)2NC6H 11 Amines are classified as primary, secondary, or tertiary amines, depending on whether one, two, or three hydrogen atoms of ammonia are substituted. Most amines are basic and can readily combine with acids to form salts, some of which can be used as delayed-action catalysts. The catalytic activity of tertiary amines depends on their structure and basicity.

[0120] Amines and organometallic compounds have been found to be most useful in this invention. Selective use of amine combinations is employed to establish an optimal balance between reactivity, fluidity, and increased viscosity, and to ensure "curing" (i.e., complete reaction) if necessary. Organometallic compounds can be used alone or preferably in combination with strongly basic amines.

[0121] The appropriate amount of catalyst (D) that can be added to the reactive mixture, based on the total weight of the isocyanate reactive component (B), is between 0.01 wt% and 10.0 wt%, or between 0.1 wt% and 5.0 wt%.

[0122] Surfactant (E)

[0123] Surfactants typically support the homogenization of the blowing agent mixture (C) and the isocyanate reactive component (B) and modulate the cell structure during foaming. Surfactant (D) may comprise any suitable surfactant or mixture of surfactants known in the art.

[0124] Non-limiting examples of suitable surfactants (D) include various silicone surfactants, sulfonates such as alkali metal salts and / or ammonium salts of oleic acid, stearic acid, dodecylbenzene disulfonic acid or dinaphthylmethane disulfonic acid and ricinoleic acid, foam stabilizers such as siloxane alkylene oxide copolymers and other organopolysiloxanes, oxyethylated alkylphenols, oxyethylated fatty alcohols, paraffin oil, castor oil, castor oil esters and castor oil esters, and cell conditioners such as paraffin, fatty alcohols and dimethylpolysiloxanes. Non-limiting examples of surfactants (D) are organosilicone glycol copolymers, while other suitable surfactants (D) include organopolysiloxane products, which are... The product name can be obtained from Air Products or You can obtain Evonik. Alternatively, you can use the Evonik brand name. Siloxane-free surfactants.

[0125] The appropriate amount of surfactant (E) that can be added to the reactive mixture, based on the total weight of the isocyanate reactive component (B), is between 0.01 wt% and 5.0 wt%, or between 0.01 wt% and 2.0 wt%.

[0126] Additives (F)

[0127] Additives (F) that can be added to the reactive mixture in Example 1 may be selected from alkylene carbonates, carbamates, pyrrolidones, dyes, pigments, colorants, IR absorbing materials, UV stabilizers, antifungal agents, bacteriostatic agents, hydrolysis control agents, curing agents, antioxidants, flame retardants, dispersants, and cell conditioners. Suitable amounts of these additives are from 0.1% to 20% by weight of the total weight of the mixture. Further details regarding these additives can be found, for example, in Kunststoffhandbuch, Vol. 7, "Polyurethanes," Carl-Hanser-Verlag Munich, 1st edition, 1966; 2nd edition, 1983; and 3rd edition, 1993.

[0128] The appropriate amount of these additives (F) that can be added to the reactive mixture is between 0.01% by weight and 10.0% by weight, based on the total weight of the isocyanate reactive component (B).

[0129] The reaction of the reactive mixture in Example 1 occurred at an index between 70 and 120. In another embodiment, the index was between 80 and 120, or between 80 and 110, or between 90 and 110. In the context of this invention, an index of 100 corresponds to one isocyanate group for each isocyanate reactive group.

[0130] In one embodiment, the isocyanate reactive component (B) in Example 1 comprises (a), (b), (c), (d), a foaming agent mixture (C), and optionally one or more of a polymeric polyol (e), a catalyst (D), a surfactant (E), and an additive (F). The isocyanate reactive component (B) is also referred to as the B-side component, while the isocyanate component (A) is referred to as the A-side component.

[0131] In another embodiment, the B-side component is mixed with the A-side component at a suitable index to form a reactive mixture, thereby forming the viscoelastic elastomer PU foam of Example 1. As described herein, the B-side component comprises (a), (b), (c), (d), a blowing agent mixture (C), and optionally one or more of a polymeric polyol (e), a catalyst (D), a surfactant (E), and an additive (F). Suitable amounts of components (a), (b), (c), (d), (e), (C), (D), (E), and (F) are described herein.

[0132] As described herein, the viscoelastic elastomer PU foam of Example 1 is based on a renewable raw material, namely natural oil polyol (a). The high content of renewable raw materials makes this invention environmentally sustainable. Furthermore, the viscoelastic elastomer PU foam of Example 1 possesses acceptable or even improved properties, such as, but not limited to, shock absorption, dynamic impact attenuation, water absorption, hysteresis loss, recovery time, and acceptable mechanical properties. Specifically, the density of the viscoelastic elastomer PU foam of Example 1 is 90 kg / m³. 3 Up to 450kg / m 3 Between (as determined by ASTM D1622); recovery time adjustable between 10 and 60 seconds (as determined by ASTM D3574); water absorption less than 10% by weight after 24 hours (as determined by ASTM D2842); and hysteresis loss up to 96% at 75% deflection and up to 83% at 40% deflection (as determined by ASTM D3574).

[0133] The viscoelastic PU foam with a microporous structure described herein has a skin-core density distribution. Upon impact, the foam dynamically hardens and dynamically delays the force transmission rate. Unlike existing flexible PU foams with open-cell structures, the foam in this invention works synergistically from skin to core to absorb impact energy, which can provide a new solution for impact energy management.

[0134] Regarding impact absorption, the advantages associated with the viscoelastic elastomer PU foam of Example 1 can be summarized as follows: (i) a sustainable solution with high renewable content; (ii) low water absorption; (iii) improved adhesion to fabrics and other plastic materials, i.e., it can be foamed directly on textiles or TPU films; (iv) less force transmission at higher impact velocities compared to prior art flexible PU foams, and significantly delayed force transmission at lower impact velocities compared to prior art viscoelastic flexible PU foams. The PU foam of the present invention provides a new solution for impact energy management; (v) a wide isocyanate index range results in good processability, while the wide processing window of the reactive mixture makes the viscoelastic elastomer PU foam ideal for a wide range of materials requiring hardness; (vi) lightweight, with competitive performance compared to higher-density products in prior art viscoelastic flexible PU foams, i.e., high energy absorption performance at lower densities; (vii) adjustable viscoelastic properties, recovery time, and hardness suitable for various applications.

[0135] The aforementioned advantages of the viscoelastic PU foam of Example 1 make it suitable for a wide range of applications. For example, the combination of impact resistance and acceptable or improved mechanical properties makes the viscoelastic PU foam of Example 1 suitable for use in protective equipment. Such protective equipment includes military and sportswear applications, protective pads for healthcare and medical applications such as table mats, hospital mattresses, wheelchair cushions, etc., and other similar areas where protection against sudden impacts is required. Exemplary articles that can be manufactured using the viscoelastic PU foam of the present invention of Example 1 include, but are not limited to, wearable products such as safety equipment and devices, such as headwear, shoulder pads, knee pads, elbow pads, helmets; and consumer products such as seat cushions, pillows, and insoles.

[0136] method

[0137] Another aspect of the present invention is Example 2, which relates to a method for preparing the viscoelastic elastomer PU foam of Example 1. In one embodiment, the viscoelastic elastomer PU foam of Example 2 is prepared by a single-step method, wherein the reactive mixture is obtained by mixing side A and side B components at a suitable index. The temperature range of side A or side B components can be between 15°C and 40°C, or between 20°C and 35°C. Side A and side B components are thoroughly mixed and reacted to prepare the foam article.

[0138] In one embodiment, the viscoelastic elastomer PU foam of Example 1 is produced in a mold. For this purpose, the A-side component and the B-side component are mixed to form a reactive mixture before the reactive mixture is placed in the mold via a mixing station, mixer, or mixing device. For example, the reactive mixture can be poured into an open mold or injected into a closed mold. The mold temperature can be in the range of 20°C to 65°C, or between 30°C and 60°C, and is controlled by a temperature control unit.

[0139] For the purposes of the currently claimed invention, each of the A-side component and the B-side component is presented as a separate stream, for example, in a mixing apparatus prior to foaming. In one embodiment, the invention relates to a two-component system, namely, A-side component and B-side component, respectively. However, a multi-component system may also be used. The term "multi-component system" refers to any number of streams, at least more than the two streams conventionally present in a two-component system. For example, three, four, five, six, or seven separate streams may be fed into the mixing apparatus. As described above, these additional streams may include one or more selected from components (a), (b), (c), (d), (e), (C), (D), (E), and (F). In one embodiment, as described in Example 1, each stream in the multi-component system is different from the A-side component and the B-side component. In another embodiment, the third stream may be a mixture of (C) with at least one selected from (D), (E), and (F), while the first stream may be pure isocyanate and the second stream may be a pure isocyanate reactive component, namely, one or more selected from components (a), (b), (c), (d), and (e).

[0140] Suitable mixing devices for the purposes of the currently claimed invention are well known to those skilled in the art, such as mixing heads or static mixers. While it is preferred that each stream enters the mixing device individually, the components in each stream can be adequately mixed by a suitable mixing device (e.g., a static mixer). Furthermore, mixing can be continuous or discontinuous, depending on the end application of the viscoelastic PU foam.

[0141] Static mixers are well known to those skilled in the art for mixing liquids, for example, as described in EP 0 097 458. Typically, a static mixer is a tubular device with fixed internal components used to mix individual streams of material across a tube cross-section. Static mixers can be used for continuous processes involving various operations, such as mixing, mass exchange between two phases, chemical reactions, or heat transfer. Homogenization of the stream is achieved by means of a pressure gradient generated by a pump.

[0142] As described above, the mixing device can be a low-pressure or high-pressure mixing device, which includes:

[0143] (A) A pump that supplies material flow.

[0144] (B) High-pressure mixing head, in which the material flow is mixed.

[0145] (C) A first feed line fitted to the mixing head, through which a first flow including the A-side component is introduced into the mixing head, and

[0146] (D) A second feed line assembled to the mixing head, through which a second flow including the B-side component is introduced into the mixing head.

[0147] Optionally, as described above, the mixing device may further include at least one measuring and control unit for establishing the pressure in each feed line of the mixing head. Furthermore, the term "low pressure" herein refers to a pressure between 0.1 MPa and 5 MPa or between 1 MPa and 3 MPa, while the term "high pressure" refers to a pressure above 5 MPa, for example, between 10 MPa and 25 MPa or between 12 MPa and 25 MPa.

[0148] In one embodiment, when used to manufacture molded articles, the viscoelastic elastomer PU foam of Example 1 or 2 has the advantage of facilitating the micro-dispensing (micro-casting) of small-sized articles. For example, small-sized articles may have a weight as low as a few grams (e.g., 50g, 10g, etc.), or shapes such as, but not limited to, strips and circular pads.

[0149] In another embodiment, the viscoelastic elastomer PU foam of Example 2 is easy to process using conventional foaming machine systems and can easily produce bulk or block foam and molded foam products.

[0150] use

[0151] Another aspect of the present invention is Example 3, which relates to the use of the viscoelastic elastomer PU foam of Example 1 or 2 in molded articles.

[0152] In this document, suitable molded articles refer to protective equipment. Such protective equipment includes military and sportswear applications, protective pads for healthcare and medical applications such as table mats, hospital mattresses, wheelchair cushions, etc., and other similar areas where protection against sudden impacts is required. Exemplary articles that can be manufactured using the viscoelastic elastomer PU foam of Example 1 of the present invention include, but are not limited to, wearable products such as headwear, shoulder pads, knee pads, elbow pads, and helmets; and consumer products such as seat cushions, pillows, and insoles.

[0153] Molded products

[0154] Another aspect of the present invention is Embodiment 4, which relates to a molded article comprising a viscoelastic elastomer PU foam as described in Embodiment 1 or 2 herein.

[0155] The invention claimed is illustrated in more detail by the following embodiments and combinations thereof, which arise from references and connections to corresponding dependent items:

[0156] I. A viscoelastic elastomer polyurethane foam obtained by reacting a reactive mixture, said reactive mixture comprising:

[0157] (A) An isocyanate component comprising at least one isocyanate prepolymer (A1), wherein the NCO content of the isocyanate component is between 10% by weight and 30% by weight, and

[0158] (B) An isocyanate reactive component, said isocyanate reactive component comprising a mixture of the following substances:

[0159] (a) 60% to 95% by weight of at least one natural oil polyol, determined according to DIN 53240, wherein the average functionality of the at least one natural oil polyol is between 2.0 and 4.0 and the OH value is between 30 mg KOH / g and 600 mg KOH / g.

[0160] (b) 0.1% to 10.0% by weight of at least one first polyether polyol, determined according to DIN 53240, wherein the average functionality of the at least one first polyether polyol is between 2.5 and 5.0 and the OH value is between 200 mg KOH / g and 450 mg KOH / g, wherein the at least one first polyether polyol is prepared by adding at least one epoxide to an amine.

[0161] (c) 1.0 wt% to 30.0 wt% of at least one second polyether polyol, determined according to DIN 53240, having an average functionality between 2.0 and 4.0 and an OH value between 20 mg KOH / g and 200 mg KOH / g, wherein the at least one second polyether polyol is prepared by adding ethylene oxide and propylene oxide to at least one H-functional initiator substance, wherein the proportion of ethylene oxide, based on the weight of the second polyether polyol, is between 40 wt% and 95 wt%, and

[0162] (d) From 0% to 10.0% by weight of at least one chain extender and / or crosslinker, wherein the molecular weight of the at least one chain extender and / or crosslinker is between 40 g / mol and 499 g / mol, wherein the weight percentage is the sum of (a), (b), (c) and (d), in the presence of the following substances:

[0163] (C) A foaming agent mixture comprising water (C1) and (C2) at least one hydrofluorocarbon or (C3) at least one hydrofluoroolefin.

[0164] II. The viscoelastic elastomer polyurethane foam according to Example I, wherein the NCO content of the isocyanate component is between 15% by weight and 29% by weight.

[0165] III. The viscoelastic elastomer polyurethane foam according to Example I or II, wherein the isocyanate component (A) further comprises at least one selected from the group consisting of: (A2) carbodiimide-modified isocyanate, (A3) polymeric methylene diphenyl diisocyanate, (A4) isocyanate comprising biuret and / or isocyanurate groups, and (A5) 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and / or 4,4'-diphenylmethane diisocyanate.

[0166] IV. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to III, wherein the isocyanate component is a mixture of (A1) isocyanate prepolymer and (A2) carbodiimide-modified isocyanate.

[0167] V. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to IV, wherein the amount of the isocyanate prepolymer (A1) is between 10% by weight and 90% by weight based on the total weight of the isocyanate component (A).

[0168] VI. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to V, wherein the amount of the isocyanate prepolymer (A1) is between 40% by weight and 60% by weight based on the total weight of the isocyanate component (A).

[0169] VII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to VI, wherein the isocyanate prepolymer (A1) is obtained by reacting a monomeric isocyanate with a prepolymer polyol.

[0170] VIII. The viscoelastic elastomer polyurethane foam according to Example VII, wherein the monomer isocyanate is 4,4'-diphenylmethane diisocyanate.

[0171] IX. The viscoelastic elastomer polyurethane foam according to one or more of Examples III to VIII, wherein the carbodiimide-modified isocyanate (A2) is carbodiimide-modified 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and / or 4,4'-diphenylmethane diisocyanate.

[0172] X. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to IX, wherein the average functionality of the natural oil polyol (a) is between 2.0 and 3.0 and the OH value is between 100 mg KOH / g and 200 mg KOH / g, as determined according to DIN 53240.

[0173] XI. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to X, wherein the natural oil polyol (a) is castor oil and / or hydrogenated castor oil.

[0174] XII. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to XI, wherein the amount of the natural oil polyol (a) is between 75% by weight and 90% by weight, based on the sum of (a), (b), (c) and (d).

[0175] XIII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XII, wherein the average functionality of the first polyether polyol (b) is between 3.5 and 4.5 and the OH value is between 270 mg KOH / g and 320 mg KOH / g, as determined according to DIN 53240.

[0176] XIV. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to XIII, wherein the amine in the first polyether polyol (b) is selected from toluene diamine, phenylenediamine, diaminodiphenylmethane and its isomers.

[0177] XV. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to XIV, wherein the amount of the first polyether polyol (b) is between 0.5% by weight and 5.0% by weight, based on the sum of (a), (b), (c) and (d).

[0178] XVI. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XV, wherein the average functionality of the second polyether polyol (c) is between 2.5 and 3.5 and the OH value is between 40 mg KOH / g and 55 mg KOH / g, as determined according to DIN 53240.

[0179] XVII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XVI, wherein the proportion of ethylene oxide in the second polyether polyol (c) is between 60% by weight and 85% by weight, based on the weight of the second polyether polyol (c).

[0180] XVIII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XVII, wherein the amount of the second polyether polyol (c) is between 10.0% by weight and 15.0% by weight, based on the sum of (a), (b), (c) and (d).

[0181] XIX. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to XVIII, wherein the at least one chain extender and / or crosslinking agent (d) is selected from ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, 1,2-dihydroxycyclohexane, 1,3-dihydroxycyclohexane, 1,4-dihydroxycyclohexane, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, bis(2-hydroxy-ethyl)hydroquinone, dipropylene glycol, glycerol, diethanolamine, and triethanolamine.

[0182] XX. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XIX, wherein the at least one chain extender and / or crosslinking agent (d) is triethanolamine.

[0183] XXI. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to XX, wherein the amount of the at least one chain extender and / or crosslinking agent (d) is between 0.1% by weight and 2.0% by weight, based on the sum of (a), (b), (c) and (d).

[0184] XXII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXI, wherein the hydrofluorocarbon (C2) is selected from 1,1,1,2-tetrafluoroethane, 1,1,2,2-tetrafluoroethane, trifluoromethane, heptafluoropropane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,1,2,2-pentafluoropropane, 1,1,1,3-tetrafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,1,3,3-pentafluoro-n-butane, 1,1,1,4,4,4-hexafluoro-n-butane, and 1,1,1,2,3,3,3-heptafluoropropane.

[0185] XXIII. The viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXII, wherein the hydrofluorocarbon (C2) is 1,1,1,3,3-pentafluoropropane.

[0186] XXIV. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXIII, wherein the hydrofluoroolefin (C3) is selected from cis or trans-1,1,1,3-tetrafluoropropylene, 1,1,1,3-tetrafluoropropylene, 1,1,1-trifluoro-2-chloropropylene, 1-chloro-3,3,3-trifluoropropylene, 1,1,1,2,3-pentafluoropropylene, 1,1,1,4,4,4-hexafluoro-2-butene, 1-bromopentafluoropropylene, 2-bromopentafluoropropylene, 3-bromopentafluoropropylene, 1,1,2,3,3-tetra ... ,4,4-heptafluoro-1-butene, 3,3,4,4,5,5,5-heptafluoro-1-pentene, 1-bromo-2,3,3,3-tetrafluoropropene, 2-bromo-1,3,3,3-tetrafluoropropene, 3-bromo-1,1,3,3-tetrafluoropropene, 2-bromo-3,3,3-trifluoropropene, E-1-bromo-3,3,3-trifluoropropene, 3,3,3-trifluoro-2-(trifluoromethyl)propene, 1-chloro-3,3,3-trifluoropropene, 2-chloro-3,3,3-trifluoropropene, and 1,1,1-trifluoro-2-butene.

[0187] XXV. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXIV, wherein the hydrofluoroolefin (C3) is cis-1,1,1,4,4,4-hexafluoro-2-butene.

[0188] XXVI. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXV, wherein the amount of the blowing agent mixture (C) is between 0.1% by weight and 10% by weight based on the total weight of the isocyanate reactive component (B).

[0189] XXVII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXVI, wherein the reactive mixture further comprises at least one selected from a catalyst (D), a surfactant (E), and an additive (F).

[0190] XXVIII. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXVII, wherein the reaction occurs at an isocyanate index between 70 and 120.

[0191] XXIX. A viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXVIII, wherein the reaction occurs at an isocyanate index between 90 and 110.

[0192] XXX. A viscoelastic elastomer polyurethane foam according to one or more of Examples 1 to XXIX, wherein the density of the viscoelastic elastomer polyurethane foam is 90 kg / m³. 3 Up to 450kg / m 3Between (as determined by ASTM D1622); recovery time adjustable between 10 and 60 seconds (as determined by ASTM D3574); water absorption less than 10% by weight after 24 hours (as determined by ASTM D2842); and hysteresis loss up to 96% at 75% deflection and up to 83% at 40% deflection (as determined by ASTM D3574).

[0193] XXXI. A method for preparing viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXX.

[0194] XXXII. Use of viscoelastic elastomer polyurethane foam according to one or more of Examples I to XXX or obtained according to Example XXXI in molded articles.

[0195] XXXIII. According to the application of Example XXXII, the molded article is a protective device.

[0196] XXXIV. A molded article comprising a viscoelastic elastomer polyurethane foam as described in Examples I to XXX or obtained in Example XXXI.

[0197] Example

[0198] The invention currently claimed is illustrated by the following non-limiting examples:

[0199] raw material

[0200]

[0201] Standard Method

[0202] DIN 53240 OH value ASTM D1622 density ASTM D3574 Compressive force deflection (CFD) ASTM D624 Tear strength ASTM D412 Tensile strength, tensile modulus and elongation at break ASTM D3574 Compression variable ASTM D3574 Recovery time ASTM D2842 Water absorption rate ASTM D3574 Lag

[0203] Milky white time

[0204] The time interval between the start of mixing and the point at which the reactive mixture begins to rise.

[0205] gel time

[0206] The time between the start of mixing and the time it takes to pull the long "thread" or sticky substance out of the rising substance by inserting and withdrawing a wooden stick.

[0207] Full ascent time / Ascent end time

[0208] The time from the start of mixing until the foamy substance has fully expanded.

[0209] Surface drying time

[0210] The time between the start of mixing and when the foam surface can be touched with a finger or tongue depressor without sticking together.

[0211] Free foam density (FRD) = Net foam weight / Cup volume

[0212] 150 gm of the mixture of side A and side B components for each example in Table 1 was poured into a 0.946 L paper cup. The foam rise was then monitored, and the time to milky white, gel time, end of rise, surface dry time, and time to the top of the cup were recorded.

[0213] When the foam in the cup cools, the foam is cut for free-blooming density assessment, as described above.

[0214] The sample was manually mixed in a 0.946L paper cup. The A-side component and the B-side component were mixed using a drill press / mixing station, and the milky time, cup top time, gel time, rise end time and surface drying time were subsequently recorded.

[0215] General Synthesis of Viscoelastic Elastomer PU Foam

[0216] Preparation of B-side component mixtures or resins:

[0217] Add the following ingredients (see Table 1, components B excluding the blowing agent) to a container or bucket and mix using a standard mixer. Then seal the container or bucket and move it to a refrigerator. Store the mixture in the refrigerator until ready to introduce the blowing agent. Once the blowing agent is added, mix the resulting mixture in a standard mixer for 20 minutes to ensure homogeneity. Store the mixture at room temperature or in the refrigerator until ready for use.

[0218] Produce foam products in a mold with the required thickness: cut 12.7 mm thick foam samples and determine their properties according to the standard method described above.

[0219] The PU foam obtained from the above samples was then cut into different sizes, and the measured properties are recorded in Tables 2 to 5 below.

[0220] Table 1: Examples of Inventions and Comparative Inventions

[0221]

[0222] Table 2: Properties of PU Foam

[0223]

[0224] Table 3: Mechanical and viscoelastic properties of PU foam

[0225]

[0226] As shown in Table 3, the mechanical and viscoelastic properties of the examples of this invention are comparable to those of the comparative examples. For impact attenuation applications, the choice of formulation is based on the desired combination of properties.

[0227] Typically, the PU foam of the present invention exhibits significant improvements in mechanical properties compared to commercially available foams used for the same shock-absorbing applications (e.g., the same density). For example, improved compression set, CFD, and elongation characteristics are highly advantageous for such applications. For example, commercially available foams used for the same applications typically exhibit compression set of, for example, >3.80%, lower elongation of, for example, <100%, and CFD >0.98 at the same density. In addition to improved physical properties, comfort is also important for the end use. Adjustable stiffness is beneficial for product design and comfort. Tensile modulus of elasticity indicates the strength and stiffness of the foam and can serve as a reference when selecting formulations for preferred applications. As described above, examples of the present invention demonstrate high-quality foam and a soft touch attributed to the chemicals.

[0228] Table 4: Effects of foaming agent and index on physical properties

[0229] characteristic IE 5 IE 6 CE 1 CE 2 BA BA1+BA3 BA1+BA3 BA1 BA1 index 95 100 90 85 <![CDATA[Density, kg / m 3 > 144.18 144.18 144.18 144.18 CFD (50% deflection, 0 minutes) 0.671 1.375 0.962 0.491 CFD (50% deflection, 1 minute dwell) 0.208 0.279 0.31 0.227 Compression set (50% deflection, 50°C, 6 hours), % 0.66 0.33 6.707 9.8 Tear strength, kg / cm 1.63 2.16 2.29 1.73 <![CDATA[Tensile strength, kg / cm 2 > 3.78 5.14 6.14 4.095 Elongation, % 154.83 149.8 118.4 137.58 <![CDATA[Tensile modulus of elasticity, kg / cm 2 > 2.15 3.53 5.7 14.94

[0230] As shown in Table 4, comparing foams produced by an aqueous foaming system with those produced by HFO / water co-foaming, despite having the same density, the PU foam exhibits higher compression set, greater stiffness, and lower elasticity. Therefore, the elastomer behavior no longer resembles that of the elastomers described in the embodiments of this invention. For some applications in protective equipment, a robust but softer foam offers advantages in terms of flexibility and comfort.

[0231] Despite having similar densities, the comparison of PU foams results in non-competitive compression set and elongation properties. Therefore, the elastomer behavior no longer resembles that of the elastomers in the embodiments of the present invention. This makes the PU foam of the present invention more suitable for impact applications, as described herein.

[0232] Table 5a: Effects of foaming agent, density, and index on 40% time lag

[0233]

[0234] Table 5b: Effects of density and index on 75% time lag

[0235] characteristic IE1 IE 5 IE 7 IE 8 CE 2 BA BA1+BA2 BA1+BA3 BA1+BA3 BA1+BA3 BA1 index 95 95 95 100 85 <![CDATA[Density, kg / m 3 > 240.3 240.3 96.12 96.12 144.18 75% time lag, % 79.350 83.85 88.90 95.70 78.700

[0236] As described above, the viscoelastic elastomer PU foam discussed in this invention exhibits significantly improved energy absorption performance, even at lower densities, compared to commercially available foams used in the same impact absorption applications. According to ASTM D3574 measurements, the examples of the invention listed in Tables 5a and 5b show hysteresis losses as high as 96% at 75% deflection and as high as 83% at 40% deflection, which are considered highly effective in impact attenuation applications. In particular, as a measure of absorbed energy, the examples of the invention demonstrate excellent energy absorption performance at lower densities.

[0237] As shown in Tables 5a and 5b, hardness (adjusted by the index) and density affect hysteresis characteristics. Generally, for foams prepared from the same formulation with the same index, lower density foams exhibit better shock absorption performance; therefore, the examples of the present invention are superior to the comparative samples.

[0238] In general, the comparative examples from the water-blown foaming system exhibit a very uniform density from skin to core and typically have an open-cell structure. Water-blown foaming systems are generally processed at lower indices and have a fairly narrow processing window. If the system reacts at indices greater than 90 or less than 85, these comparative foams become too stiff or too soft and therefore cannot be compared with the viscoelastic elastomer PU foam of the present invention. In contrast, the PU foam of the present invention has an interesting density distribution from skin (dense) to core (less dense) and has a microporous structure. Furthermore, the foaming agent / water co-foaming system has a wider processing range, for example from an index of 85 to 105, and is therefore advantageous for hardness adjustment, which is limited for the comparative PU foam (water-blown system).

[0239] Furthermore, as shown in Tables 5a and 5b, a significant increase in hysteresis % was observed in the IE 1 HFC / H2O system at the same index and lower density (see IE 1, density 240.3 kg / m³). 3 With a density of 192.24 kg / m³ 3 Interestingly, for the HFO / H2O system, a slight increase in hysteresis % was observed at the same exponent and lower density (see, for example, HFO / H2O, IE5 and IE6, density 240.3 kg / m³). 3 With a density of 144.18 kg / m³ 3 In any of the cases described herein, selecting a lightweight foam for the final product is advantageous. For example, the foam described herein can achieve the same or better overall shock absorption performance, and it can also result in a 20% to 50% reduction in density compared to commercially available foams used for the same shock absorption applications.

[0240] As described above, the viscoelastic PU foam with a microporous structure described herein has a skin-core density distribution. Upon impact, the foam dynamically stiffens and dynamically delays the rate of force transmission. Unlike prior art flexible PU foams with open-cell structures, the foam in this invention works synergistically from skin to core to absorb impact energy, which can provide a new solution for impact energy management.

Claims

1. A viscoelastic elastomer polyurethane foam obtained by reacting a reactive mixture, said reactive mixture comprising: (A) An isocyanate component comprising at least one isocyanate prepolymer (A1), wherein the NCO content of the isocyanate component is between 10% by weight and 30% by weight, and (B) An isocyanate reactive component, said isocyanate reactive component comprising a mixture of the following substances: (a) 60% to 95% by weight of at least one natural oil polyol, determined according to DIN 53240, wherein the average functionality of the at least one natural oil polyol is between 2.0 and 4.0 and the OH value is between 30 mg KOH / g and 600 mg KOH / g. (b) 0.1% to 10.0% by weight of at least one first polyether polyol, determined according to DIN 53240, wherein the average functionality of the at least one first polyether polyol is between 2.5 and 5.0 and the OH value is between 200 mg KOH / g and 450 mg KOH / g, wherein the at least one first polyether polyol is prepared by adding at least one epoxide to an amine. (c) 1.0% to 30.0% by weight of at least one second polyether polyol, determined according to DIN 53240, wherein the average functionality of the at least one second polyether polyol is between 2.0 and 4.0 and the OH value is between 20 mg KOH / g and 200 mg KOH / g, wherein the at least one second polyether polyol is prepared by adding ethylene oxide and propylene oxide to at least one H-functional initiator substance, wherein the proportion of ethylene oxide, based on the weight of the second polyether polyol, is between 40% and 95% by weight. (d) at least one chain extender and / or crosslinking agent, from 0% to 10.0% by weight, wherein the molecular weight of the at least one chain extender and / or crosslinking agent is between 40 g / mol and 499 g / mol. The weight percentage is calculated as the sum of (a), (b), (c), and (d). In the presence of the following substances (C) A foaming agent mixture comprising water (C1) and (C2) at least one hydrofluorocarbon.

2. The viscoelastic elastomer polyurethane foam according to claim 1, wherein the foaming agent mixture comprises water (C1) and at least one hydrofluoroolefin (C3).

3. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the isocyanate component (A) further comprises at least one selected from the group consisting of: (A2) carbodiimide-modified isocyanate, (A3) polymeric methylene diphenyl diisocyanate, (A4) isocyanate comprising biuret and / or isocyanurate groups, and (A5) 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and / or 4,4'-diphenylmethane diisocyanate.

4. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the isocyanate component is a mixture of (A1) isocyanate prepolymer and (A2) carbodiimide modified isocyanate.

5. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the amount of the isocyanate prepolymer (A1) is between 10% by weight and 90% by weight based on the total weight of the isocyanate component (A).

6. The viscoelastic elastomer polyurethane foam according to claim 3, wherein the carbodiimide-modified isocyanate (A2) is carbodiimide-modified 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate and / or 4,4'-diphenylmethane diisocyanate.

7. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the natural oil polyol (a) is castor oil and / or hydrogenated castor oil.

8. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the amine in the first polyether polyol (b) is selected from toluene diamine, phenylenediamine and diaminodiphenylmethane.

9. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the proportion of ethylene oxide in the second polyether polyol (c) is between 60% by weight and 85% by weight, based on the weight of the second polyether polyol (c).

10. The viscoelastic elastomer polyurethane foam according to claim 1, wherein the hydrofluorocarbon (C2) is 1,1,1,3,3-pentafluoropropane.

11. The viscoelastic elastomer polyurethane foam according to claim 2, wherein the hydrofluoroolefin (C3) is cis-1,1,1,4,4,4-hexafluoro-2-butene.

12. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the reactive mixture further comprises an additive (F).

13. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the reactive mixture further comprises at least one selected from a catalyst (D) and a surfactant (E).

14. The viscoelastic elastomer polyurethane foam according to claim 1 or 2, wherein the reaction occurs at an isocyanate index between 70 and 120.

15. A method for preparing a viscoelastic elastomer polyurethane foam according to any one of claims 1 to 14, wherein an A-side component and a B-side component are thoroughly mixed and reacted to prepare a foam article, wherein the A-side component is the isocyanate component (A), and the B-side component comprises the isocyanate reactive component (B) and the foaming agent mixture (C).

16. Use of the viscoelastic elastomer polyurethane foam according to any one of claims 1 to 14 or the viscoelastic elastomer polyurethane foam obtained by the method according to claim 15 in molded articles.

17. A molded article comprising a viscoelastic elastomer polyurethane foam according to any one of claims 1 to 14 or a viscoelastic elastomer polyurethane foam obtained by the method according to claim 15.

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