Polyurethane foam, method for preparing the same, and article thereof

Abstract

The present invention relates to a polyurethane foam with a relatively high biobased content. The present invention also relates to a method for preparing the polyurethane foam and an article comprising the polyurethane foam.

Description

[0001] POLYURETHANE FOAM, METHOD FOR PREPARING THE SAME, AND ARTICLE THEREOF

[0002] TECHNICAL FIELD

[0003] The present invention relates to the field of polyurethane, and in particular a polyurethane foam with a relatively high biobased content. The present invention also relates to a method for preparing the polyurethane foam and an article comprising the polyurethane foam.

[0004] BACKGROUND ART

[0005] Polyurethane foams have a wide range of applications, almost covering all sectors of the national economy. Especially, they are commonly used in areas such as furniture, bedding, transportation, refrigeration, construction and thermal insulation, and have become one of the indispensable materials. Polyurethane foams have many advantages including, among other things, being porous, having relatively low density, high specific strength, low thermal conductivity, corrosion resistance, and ease of manufacturing.

[0006] CN111465630A discloses a flexible polyurethane foam prepared by reacting toluene diisocyanate with an isocyanate-reactive component in the presence of a foaming agent, a catalyst and a surfactant. The flexible polyurethane foam has a relatively low compression set. CN104341573 A relates to a polyurethane foam plastic. The polyurethane foam plastic is prepared by using methyl formate instead of CFCs, HCFCs, HFCs, alkane, dichloromethane, water and other foaming agents or using methyl formate to mix with CFCs, HCFCs, HFCs, alkane, di chloromethane, water and the like to serve as a foaming agent.

[0007] Currently, there is a growing demand for a low-carbon, environmentally-friendly polyurethane foam with a high biobased content. However, when the biobased content is relatively high in existing polyurethane foam formula systems, foam maturation and flowing would be affected. Therefore, developing a polyurethane foam with a relatively high biobased content, while also demonstrating excellent mold release and process performance, poses a significant challenge in this field. SUMMARY OF THE INVENTION

[0008] In an aspect, the present invention relates to a polyurethane foam prepared from a composition comprising (A) an isocyanate component, (B) an isocyanate-reactive component and (C) an additive component, wherein the (A) isocyanate component comprises at least one polyisocyanate; the (B) isocyanate-reactive component comprises: (b 1 ) a poly ether polyol having a functionality of 3 to 10, preferably 4 to 8, and a hydroxyl value of 20 to 60 mg KOH / g, preferably 25 to 40 mg KOH / g; optional (b2) a PHD polyol having a functionality of 2 to 6, preferably 3 to 5, and a hydroxyl value of 20 to 40 mg KOH / g, preferably 35 to 45 mg KOH / g; optional (b3) a polyester polyol having a functionality of 2 to 4, preferably 2 to 3, and a hydroxyl value of 80 to 200 mg KOH / g, preferably 100 to 150 mg KOH / g; and (b4) a vegetable oil-based polyol in an amount of 10 to 39% by weight, preferably 10 to 35% by weight, based on the total weight of (B) and (C) components.

[0009] In another aspect, the present invention also relates to a method for preparing a polyurethane foam of the present invention, comprising the following step: mixing and reacting the (A) isocyanate component with the (B) isocyanate-reactive component in the presence of the (C) additive component to obtain the polyurethane foam.

[0010] In yet another aspect, the present invention also relates to an article comprising a polyurethane foam of the present invention.

[0011] BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG. 1 : A picture showing the surface state of the polyurethane foam of Comparative Example 1.

[0013] FIG. 2: A picture showing the surface state of the polyurethane foam of Comparative Example 2.

[0014] FIG. 3: A picture showing the surface state of the polyurethane foam of Comparative Example 3.

[0015] FIG. 4: A picture showing the surface state of the polyurethane foam of Example 1 of the present invention.

[0016] DETAILED DESCRIPTION OF THE INVENTION

[0017] General definitions and terms

[0018] If not indicated otherwise, all publications, patent applications, patents and other reference documents mentioned herein are incorporated by reference in their entirety. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the field the present invention belongs to. In the event of a contradiction, the definitions provided herein shall prevail.

[0019] Unless otherwise specified, all percentages, parts, proportions, etc. are based on weight. It is to be understood by a person skilled in the art that the sum of all components in the composition may suitably be 100%. When quantities, concentrations, or other values or parameters are presented as ranges, preferred ranges, or preferred upper limit value and lower limit value or specific values, they should be construed as specifically disclosing all ranges formed by pairs of values from any upper range or preferred value to any lower range or preferred value, irrespective of whether the ranges are individually disclosed. Unless otherwise specified, when a range of values is quoted herein, said range is meant to include the endpoints, and all integers and fractions within that range.

[0020] When the term “about” or “approximately” is used in conjunction with a numerical variable, this usually means that the value of the variable and all values of the variable are within the experimental margin of error (e.g. within a 95% confidence interval for the mean value) or within ±10% of a specified value, or within a wider range.

[0021] As used herein, the term “optional” or “optionally” means that the events or circumstances described thereafter may or may not occur, including the occurrence and non-occurrence of the events or circumstances, and optional selection of the content described thereafter. For example, when a certain component is in an amount of 0% to 5%, said component may be optionally present, i.e., this covers the circumstances where the component is absent (0%) and present (>0 to 5%).

[0022] The terms “include”, “comprise”, “have”, “contain” or “relate to” and other variations thereof are inclusive or open-ended, and do not exclude other unenumerated elements or method steps. It is to be understood by a person skilled in the art that the above terms such as “include” cover the meaning of “consisting of . . . ”. The expression “consisting of ...” excludes any unspecified elements, steps or components. The expression “substantially consisting of ...” means that the scope is limited to the specified elements, steps or components, plus optional elements, steps or components that do not substantially affect the essential and new features of the claimed subjected matter. It is to be understood that the expression “comprise” covers the expressions “substantially consisting of ... ” and “consisting of . . . ”. The term “be selected from ...” means independently selecting one or more elements of the group listed thereafter, and may include a combination of two or more elements therein. As used herein, the term “one or more” or “at least one” refers to one, two, three, four, five, six, seven, eight, nine or more types.

[0023] As used herein, the term “and / or” covers the meaning of “and” and “or”. A plurality of elements, components or steps defined by “and / or” refer to any one of said elements, components or steps and any combination thereof. For example, A and / or B covers A, B and A+B; A, B and / or C covers A, B, C, A+B, A+C, B+C and A+B+C.

[0024] Unless otherwise specified, the terms “combinations thereof’, “any combination thereof’ and “a mixture thereof’ refer to a multicomponent mixture of various elements, for example, a multicomponent mixture of two, three, four and up to the maximum possible types of elements.

[0025] In addition, where the number of parts or components of the present invention is unspecified, there is no limitation as to the number of the parts or components that appear (or exist). Thus, this shall be construed to include one or at least one, and the singular form of the parts or components also include the plural form, unless the value is obviously expressed as singular.

[0026] As used herein, “a plurality of’ means two or more, unless otherwise expressly and specifically defined. “One” may cover singular reference and plural reference, unless the context clearly indicates otherwise.

[0027] The functionality of polyols refers to the value determined according to the equation: functionality = hydroxyl value x molecular weight / 56100, wherein the molecular weight is determined by GPC high performance liquid chromatography, and the test method refers to GB / T 21863-2008.

[0028] The hydroxyl value refers to the number of milligrams of potassium hydroxide equivalent to the hydroxyl content of 1 g of a test portion. The test method refers to ISO 14900-2017.

[0029] Unless otherwise indicated, the functionality and hydroxyl value in the present invention refer to the average functionality and average hydroxyl value.

[0030] The term “flexible” refers to the property of flexibility demonstrated by materials possessing a certain degree of resilience. The foam structure of a flexible polyurethane foam is mostly open-cell. The flexible polyurethane foam typically has properties such as good elastic recovery, sound absorption, air permeability and thermal insulation, and thus is suitable for application fields of flexible materials. Flexible materials typically have a surface hardness of 100 or less, for example, 70 or less, determined by Asker C test. Polyurethane Foam

[0031] In an aspect, the present invention relates to a polyurethane foam prepared from a composition comprising (A) an isocyanate component, (B) an isocyanate-reactive component and (C) an additive component.

[0032] (A) Isocyanate component

[0033] The (A) isocyanate component comprises at least one polyisocyanate. The polyisocyanate may be any aliphatic, alicyclic or aromatic polyisocyanate known to be used for the preparation of polyurethanes. Examples of the polyisocyanate include, but are not limited to, toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), 1,5 -naphthalene diisocyanate (NDI), hexamethylene diisocyanate (UDI), methylcyclohexane diisocyanate (HTDI), 4,4'- dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), p-phenylene diisocyanate (PPDI), p- xylyl diisocyanate (XDI), tetramethyldimethylene diisocyanate (TMXDI), polymers thereof, or combinations thereof. The polyisocyanate that can be used in the present invention preferably has a functionality of 2.0 to 3.5, particularly preferably 2.1 to 2.9. The polyisocyanate preferably has a viscosity of 5 to 700 mPa-s, particularly preferably 10 to 300 mPa-s, measured at 25°C according to DIN 53019-1-3.

[0034] The isocyanate may include a polyisocyanate dimer, trimer, tetramer, pentamer, or combinations thereof.

[0035] In the preferred embodiments of the present invention, the (A) isocyanate component is selected from diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), polymers thereof, prepolymers thereof, or combinations thereof.

[0036] Polyisocyanate prepolymers of the present invention may have an NCO content of 15 to 33% by weight, preferably 20 to 32% by weight, more preferably 23 to 30% by weight. The NCO content is measured according to GB / T 12009.4-2016.

[0037] The content of the (A) isocyanate component of the present invention may be 20 to 150% by weight, preferably 30 to 75% by weight, for example, 71, 72, 73 or 74% by weight, based on the total weight of the (B) isocyanate-reactive component and the (C) additive component.

[0038] Blocked isocyanates may also serve as the (A) isocyanate component, and they can be prepared by reacting an excess of organic polyisocyanates or combinations thereof with polyol compounds. A person skilled in the art knows well these compounds and their preparation methods. (B) Isocyanate-reactive component

[0039] The (B) isocyanate-reactive component comprises (bl) a poly ether polyol, optional (b2) a PHD polyol, optional (b3) a polyester polyol and (b4) a vegetable oil-based polyol.

[0040] (bl) Polyether polyols

[0041] The (B) isocyanate-reactive component comprises a polyether polyol. Polyether polyols can be prepared by known processes, for example, by reacting olefin oxides with an initiator, in the presence of a catalyst. The catalysts include, but are not limited to, alkaline hydroxide, alkaline alcohol salt, antimony pentachloride, boron fluori de-ethyl ether, or combinations thereof. The olefin oxides include, but are not limited to, tetrahydrofuran, ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3- butylene oxide, styrene oxide, or combinations thereof, particularly preferably ethylene oxide and / or propylene oxide. The initiator can be adjusted according to the functionality, viscosity and other properties of polyether polyols, and is preferably, but not limited to, a polyhydroxyl compound or a polyamino compound. The polyhydroxyl compounds include, but are not limited to, sorbitol, water, ethylene glycol, 1,2-propanediol, 1,3- propanediol, diethylene glycol, trimethylolpropane, glycerol, bisphenol A, bisphenol S, or combinations thereof. The polyamino compounds include, but are not limited to, ethylenediamine, propylenediamine, butylenediamine, hexylenediamine, diethylenetriamine, toluene diamine, or combinations thereof.

[0042] In an embodiment, the polyether polyol may be propylene oxide / ethylene oxide (POZEO) capped, e.g., having a PO and / or EO capped structure. The EO content may be 10 to 30%, preferably 12 to 25%. For example, the EO content may be 16, 17, 18 or 19%. Correspondingly, the PO content may be 70 to 90%, preferably 75 to 88%. Each amount in this paragraph is an amount by weight, based on the total weight of alkylene oxide in the polyether polyol.

[0043] In an embodiment, the polyether polyol may have a functionality of 3 to 10, preferably greater than 3 and below or equal to 10, more preferably 4 to 8, for example, 3.1, 3.2, 3.3, 3.4, 3.5, 4, 5, 6, 7, 8, 9, 10 etc. The selection of the functionality shall also be taken into account for obtaining suitable reaction products. Too low or too high a functionality is not conducive to achieving desired properties of the products.

[0044] In an embodiment, the polyether polyol may have a hydroxyl value of 20 to 60 mg KOH / g, preferably 25 to 40 mg KOH / g, for example, 28, 29 or 30 mg KOH / g.

[0045] In an embodiment, the content of the (bl) polyether polyols may be 30 to 80% by weight, preferably 40 to 60% by weight, for example, 35% by weight, 40% by weight, 44.5% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 80% by weight etc., based on the total weight of the (B) isocyanate-reactive component and the (C) additive component.

[0046] (b2) PHD polyols

[0047] In an embodiment, the (B) isocyanate-reactive component may optionally comprise a PHD polyol. The PHD polyols, also known as polyhydrazodicarbonamide polyols (or polyhydrazodicarbonamide dispersion polyols), are a type of modified polyether polyols. Generally, the PHD polyols are prepared by in-situ polymerization of an isocyanate mixture with a compound comprising an amine group such as a diamine and / or a hydrazine, in base polyols. Preferred base polyols include polyether polyols and polyoxyalkylene polyols, more preferably POZEO-type polyether polyols.

[0048] In the preparation of PHD polyols, the compound comprising an amine group suitable for polymerization with the isocyanate mixture includes, but is not limited to, polyamines, hydrazines, hydrazides, ammonia, and mixtures of ammonia and / or urea and formaldehyde. Suitable polyamines include, but are not limited to, divalent and / or higher-valence primary and / or secondary aliphatic amines, araliphatic amines, alicyclic amines and aromatic amines, such as ethylenediamine, 1,2-propanediamine, 1,3- propanediamine, tetramethylene diamine, hexamethylene diamine, dodecamethylene diamine, trimethyldiaminohexane, N,N'-dimethylethylenediamine, 2,2'- bis(aminopropyl)methylamine, higher-valence ethylenediamine homologs, such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine; propylenediamine homologs, such as dipropyltriamine, piperazine, N,N'-bis(aminoethyl)-piperazine, triazine, 4-aminobenzylamine, 4-aminophenylethylamine, l-amino-3,3,5-trimethyl-5- aminomethylcyclohexane, 4,4'-diaminodicyclohexyl methane, 4,4'- diaminodi cyclohexyl propane, 1 ,4-diaminocyclohexane, phenylenediamine, naphthalenediamine; condensates of aniline and formaldehyde; toluene diamine; bis(aminomethyl)benzene and derivatives of the aromatic amines monoalkylated on one or two nitrogen atoms. The polyamines typically have a molecular weight of 60 to 10,000 g / mol, preferably 60 to 1,000 g / mol, and most preferably 60 to 200 g / mol.

[0049] The hydrazine used may be a hydrazine per se or mono-substituted or N,N'- disubstituted hydrazines, wherein the substituent may be Ci-Ce alkyl groups, cyclohexyl groups or phenyl groups. The hydrazines typically have a molecular weight of from 32 to 200 g / mol. Suitable hydrazides include those of divalent or higher- valence carboxylic acids which include, for example, carbonic acid, oxalic acid, malonic acid, butanedioic acid, adipic acid, sebacic acid, nonanedioic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and terephthalic acid; the esters of hydrazine monocarboxylic acids with diols or polyols and phenols, for example, ethylene glycol, propane- 1 ,2-diol, butane-1,2- diol, butane- 1,3 -diol, butane- 1,4-diol, hexanediol, di ethylene glycol, tri ethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol and hydroquinone; and the amides (aminoureas) of hydrazinylidene monocarboxylic acids, for example, and the diamines and polyamines as mentioned above. The hydrazines typically have a molecular weight of 90 to 10,000 g / mol, preferably 90 to 1,000 g / mol, more preferably 90 to 500 g / mol.

[0050] Isocyanates or amines, hydrazines and hydrazides having a functionality greater than 2 may also be used in certain proportions, especially when used with corresponding monofunctional compounds.

[0051] In an embodiment, the PHD polyol may have a functionality of 2 to 6, preferably 3 to 5, for example, 2, 3, 4, 5 or 6 etc. The PHD polyol may have a hydroxyl value of 20 to 40 mg KOH / g, preferably 35 to 45 mg KOH / g, for example, 39 mg KOH / g.

[0052] In an embodiment, the PHD polyol may be PO / EO capped, e.g. having a PO and / or EO capped structure. The EO content may be 10 to 25%, preferably 13 to 22%. For example, the EO content may be 16, 17, 18 or 19%. Each amount in this paragraph is an amount by weight, based on the total weight of alkylene oxide in the PHD polyol.

[0053] In an embodiment, the content of the PHD polyol is in an amount of 0 to 25% by weight, preferably 5 to 15% by weight, for example, 5% by weight, 10% by weight, 12% by weight, 13% by weight, 15% by weight, 20% by weight, 25% by weight etc., based on the total weight of the (B) isocyanate-reactive component and the (C) additive component.

[0054] As noted above, the (B) isocyanate-reactive component may optionally comprise a PHD polyol. That is, the content of the POZEO PHD polyol may be 0.

[0055] (b3) Polyester polyols

[0056] In an embodiment, the (B) isocyanate-reactive component may optionally comprise a polyester polyol. The polyester polyols may be aliphatic or aromatic polyester polyols, preferably aliphatic. The polyester polyols can be prepared by reacting dicarboxylic acids or dicarboxylic anhydrides with polyols. The dicarboxylic acids include, but are not limited to, aliphatic carboxylic acids containing 2 to 12 carbon atoms. The aliphatic carboxylic acids containing 2 to 12 carbon atoms include, but are not limited to, butanedioic acid, malonic acid, glutaric acid, adipic acid, octanedioic acid, nonanedioic acid, sebacic acid, dodecanecarboxylic acid, maleic acid, transbutenedioic acid, phthalic acid, isophthalic acid, terephthalic acid, or combinations thereof. The dicarboxylic anhydrides include, but are not limited to, phthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, or combinations thereof. The polyols that react with dicarboxylic acids or dicarboxylic anhydrides include, but are not limited to, ethylene glycol, di ethylene glycol, 1,2-propanediol, 1,3 -propanediol, dipropylene glycol, 1,3- methylpropanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, propanetri ol, trimethylolpropane, or combinations thereof. The polyester polyols may also include those prepared from lactone which is preferably, but not limited to, s-caprolactone. Preferably, the polyester polyols may have a molecular weight of 200 to 3,000 g / mol, and a functionality of 2 to 6, preferably 2 to 3.

[0057] In an embodiment, the polyester polyol may have a functionality of 2 to 4, preferably 2 to 3, for example, a functionality of 2, 2.7, 3, 4 etc. The polyester polyol may have a hydroxyl value of 80 to 200 mg KOH / g, preferably 100 to 150 mg KOH / g, for example, 109 mg KOH / g.

[0058] The content of the polyester polyol may be 0 to 15% by weight, preferably 2 to 10% by weight, for example, 2% by weight, 5% by weight, 10% by weight, 15% by weight etc., based on the total weight of the (B) isocyanate-reactive component and the (C) additive component.

[0059] As noted above, the (B) isocyanate-reactive component may optionally comprise a polyester polyol. That is, the content of the polyester polyol may be 0.

[0060] (b4) Vegetable oil-based polyols

[0061] The (B) isocyanate-reactive component comprises (b4) a vegetable oil-based polyol. The vegetable oil-based polyols include vegetable oils, vegetable oil polyols or modified products thereof. Vegetable oils are compounds prepared from unsaturated fatty acids and glycerol, or oils extracted from fruits, seeds and germs of plants, which are preferably, but not limited to, peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil and palm oil, especially castor oil. Vegetable oil polyols are polyols starting from one or more vegetable oils. The initiators for synthesizing vegetable oil polyols include, but are not limited to, soybean oil, palm oil, peanut oil, low erucic acid rapeseed oil, and castor oil. The initiators of vegetable oil polyols can be introduced with hydroxyl groups by a process such as cracking, oxidation or ester exchange, and then go through a process known to a person skilled in the art for the preparation of organic polyols, to prepare corresponding vegetable oil polyols. Vegetable oil-based polyols having a suitable functionality and / or hydroxyl value are selected for better empowering polyurethane foam with excellent properties. In an embodiment, the vegetable oil-based polyol has a functionality of 2 to 6, for example, 2, 3, 4, 5, 6 etc. In another embodiment, the vegetable oil-based polyol has a hydroxyl value of 60 to 250 mg KOH / g.

[0062] In an embodiment, the content of the vegetable oil-based polyol may be 10 to 39% by weight, preferably 10 to 35% by weight, for example, 11% by weight, 12% by weight, 13% by weight, 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, 24% by weight, 25% by weight, 26% by weight, 27% by weight, 28% by weight, 29% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, 35% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight etc., based on the total weight of the (B) isocyanate-reactive component and the (C) additive component. If the amount is too low, it would be impossible to achieve low- carbon, environmentally friendly and other objectives; if the amount is too high, the polyurethane foam would have deteriorated mold release and process performance, which is unfavorable for use. In the present invention, the reaction between (A) an isocyanate component and (B) an isocyanate-reactive component is an addition polymerization reaction of isocyanate groups with hydroxyl groups. The isocyanate groups may be those contained in the (A) isocyanate component or those contained in the intermediate product of the reaction between the (A) isocyanate component and the (B) isocyanate reactive component. The hydroxyl groups may be those contained in the (B) isocyanate-reactive component or those contained in the intermediate product of reaction between the (A) isocyanate component with the (B) isocyanate reactive component. C) Additive component

[0063] The (C) additive component may comprise (cl) a foaming agent which mainly plays the role of producing gas and forming homogenously distributed bubbles. The foaming agent may comprise water. The (cl) foaming agent may be used in an amount of 0.5 to 8.0% by weight, preferably 1.0 to 7.0% by weight, more preferably 1.5 to 6.0% by weight, for example, 2.45 or 2.5% by weight, based on the total weight of the (B) isocyanate-reactive component and the (C) additive component. Other foaming agents for use may include, but are not limited to, fluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrofluorocarbons and hydrocarbons. If necessary, foam can also be formed by directly aerating the system.

[0064] The (C) additive component may comprise (c2) a catalyst for catalyzing the reaction between isocyanate groups (NCO) and hydroxyl groups (OH). The catalyst can accelerate the initiation of polyurethane, shorten the curing time and improve the foaming quality. When the catalyst is used in a relatively small amount, the foaming reaction rate would be too low during the preparation of polyurethane foam, resulting in poor gas release and formation of closed-cell polyurethane foam. As the amount of the catalyst increases, the foaming reaction accelerates, leading to a higher open-cell content. However, if an excessive amount of the catalyst is used, the foaming reaction may be too fast, resulting in large bubbles and causing defects or even bubble collapse. The amount of the catalyst may affect the properties of polyurethane foam, such as tensile strength, tear strength, etc. The catalyst that can be used in the present invention includes, but is not limited to, amine catalysts, preferably tertiary amine catalysts. The amine catalysts include, but are not limited to, triethylamine, tributylamine, dimethylethanolamine, bis(dimethylaminoethyl) ether, triethylenediamine, N- ethylmorpholine, N,N,N',N'-tetramethyl-ethylenediamine, pentamethyldiethylidene triamine, dimethylaminopropylidene diamine, N,N,N',N'-tetramethyldipropylidene triamine, and one, two or more of the weak-acid modified products of said amine catalysts. The (c2) catalyst may be used in amount of 0.3 to 2.5% by weight, preferably 0.5 to 2.0% by weight, more preferably 0.8 to 1.8% by weight, for example, 1.15% by weight, based on the total weight of the (B) isocyanate-reactive component and the (C) additive component.

[0065] The (C) additive component may comprise (c3) a crosslinking agent. The crosslinking agent may be a small-molecule polyfunctional compound containing a plurality of active hydrogens, for example, containing 2 to 8 active hydrogens. The (c3) crosslinking agent may include diethyltoluene diamine, diethanolamine or combinations thereof. The (c3) crosslinking agent may be used in an amount of 0 to 4.0% by weight, preferably 0.5 to 3.0% by weight, more preferably 0.8 to 2.5% by weight, for example, 0.9% by weight, based on the total weight of the (B) isocyanate-reactive component and the (C) additive component.

[0066] The (C) additive component may also comprise (c4) a foam stabilizer, for improving stability of bubbles generated in the process of preparing polyurethane foam, to enhance the properties of polyurethane foam. Conventional foam stabilizers in the art may be used, for example, silicone-based foam stabilizers, fluorine-based foam stabilizers and other well-known surfactants.

[0067] The (C) additive component may also comprise (c5) an antioxidant, which can effectively suppress or decrease thermal oxidation and photooxidation reaction rate of polyurethane foam, significantly improve heat and light resistance of polyurethane foam, and slow down degradation and aging process thereof, thus extending the life of polyurethane foam. Conventional antioxidants in the art may be used, including, but not limited to: hindered phenolic antioxidants, amine antioxidants, thio-antioxidants and phosphate antioxidants etc.

[0068] The (C) additive component may further comprise (c6) a cell opener. Cell opener is a special type of surfactant that typically comprises hydrophobic and hydrophilic segments or groups. Cell openers can reduce the surface tension of foam, promote cell rupture, and increase the open-cell content of polyurethane foam, thereby giving polyurethane foam a greater value in air permeability. The (c6) cell opener may include, but is not limited to, water-soluble emulsifiers, polybutadiene, methyl polysiloxane, polypropylene oxide-ethylene oxide copolyether, polyolefin oxide-polysiloxane copolymer, etc.

[0069] The (C) additive component may further comprise (c7) a color paste, which serves to provide an appropriate color to polyurethane foam. The color paste can be added as needed to adjust the color of polyurethane foam.

[0070] The (C) additive component may further comprise other additives or adjuvants as needed, which include, but are not limited to, fillers, internal release agents, flame retardants, anti-smoke agents, anti-static agents, UV stabilizers, diluents, coupling agents, surface wetting agents, leveling agents, thixotropic agents, plasticizers, foam stabilizers, free radical reaction inhibitors, or combinations thereof.

[0071] The additives in the present invention can be adjusted as necessary. Preferably, substances with irritating odors or high volatility do not serve as additives.

[0072] The (C) additive component may optionally be stored together with the (A) isocyanate component and / or the (B) isocyanate reactive component. The (C) additive component may also be separately stored. It is mixed with the (A) isocyanate component and / or the (B) isocyanate-reactive component, prior to preparation of polyurethane foam.

[0073] In an embodiment, the total content of the additive component is 10% by weight or less, for example, 9, 8, 7, 6, 5, 4.5, 4, 3, 2, 1% by weight, based on the total weight of (B) and (C) components.

[0074] A flexible polyurethane foam typically has properties such as good elastic recovery, sound absorption, air permeability and thermal insulation, and thus can be used as, for example, a support material, acoustic insulation material, thermal insulation material, or filtration material. In an embodiment, the polyurethane foam of the present invention may be a flexible polyurethane foam. In this case, it can also be referred to as “polyurethane flexible foam” or “soft polyurethane foam” etc. Flexible foam typically has a smaller surface hardness. Surface hardness can be determined, for example, by Asker C test. Generally, surface hardness of a flexible polyurethane foam is 100 (Asker C) or less, for example, 70 (Asker C) or less.

[0075] Properties of polyurethane foam

[0076] The polyurethane foam of the present invention has a relatively high biobased content, while also demonstrating excellent mold release and process performance. In an embodiment, the polyurethane foam of the present invention may have one or more of the following properties: open-cell content, density, tensile strength, elongation at break, tear strength, and compression set. Open-cell content refers to the proportion of the volume of open cells connected to the outside space to the total volume of all cells, which can be determined, for example, according to ASTM D 2856-98 standard. The polyurethane foam may have an open-cell content of >50%, preferably >70%, according to ASTM D 2856-98 standard.

[0077] The polyurethane foam may have a density of >10 kg / m3, preferably >80 kg / m3, more preferably >100 kg / m3.

[0078] Tensile strength characterizes a material’ s ability to resist maximum uniform plastic deformation, which can be determined, for example, according to DIN53571 standard. In an embodiment, the polyurethane foam may have a tensile strength of >200 kPa, according to DIN53571 standard.

[0079] When a material is subjected to an external force until it breaks, the ratio of the elongation of the material after stretching to the length before stretching is called the elongation at break. The greater the elongation at break, the better the flexibility and elasticity of the material. The elongation at break can be determined, for example, according to DIN 53571 standard. The polyurethane foam may have an elongation at break of >30%, according to DIN 53571 standard.

[0080] Tearing refers to a destructive phenomenon caused by rapid expansion of cracks or fissures in a material when subjected to a force, and it is one of the indicators for measuring a material’s resistance to destruction. The tearing of polyurethane foam generally develops along the path of least resistance, with cracks developing in the direction where the internal structure is weaker. The weak gaps in the structure form an irregular tearing path, contributing to tearing destruction. The tear strength can be determined, for example, according to ISO34-1 standard. The polyurethane foam may have a tear strength of >300 N / m, preferably >2500 N / m, according to ISO34-1 standard.

[0081] Compression set is also known as permanent compression deformation. Typically, a sample with a known height can be compressed to a specific height according to compression rate requirements, then held at specified temperature conditions for a certain period of time, before being uncompressed to allow it to recover in its free state, to measure the height of the sample. The smaller the compression set, the better the resilience of the material and the stronger the resistance to deformation. The compression set can be determined according to, for example, DIN53572 standard. The polyurethane foam may have a 50% compression set of <10%, according to DIN53572 standard. Preparation Method

[0082] In another aspect, the present invention also relates to a method for preparing a polyurethane foam, comprising the following step: mixing and reacting the (A) isocyanate component with the (B) isocyanate-reactive component, in the presence of the (C) additive component to obtain the polyurethane foam.

[0083] There is no explicit limitation on the sequence of mixing the (A) isocyanate component, the (B) isocyanate-reactive component and the (C) additive component. Any two components can be mixed before the addition of the remaining component, or all components can be added at the same time, and mixed altogether.

[0084] A suitable sequence of mixing can be selected as needed. For example, the (A) isocyanate component and the (B) isocyanate-reactive component can be first prepared into a prepolymer, before the addition of the (C) additive component; they are mixed while stirring for foaming, and after curing, they undergo maturation at a certain temperature. Alternatively, part of the (A) isocyanate component and the (B) isocyanate- reative component can be first prepared into a prepolymer, before the addition of the (C) additive component and the remainining (A) isocyanate component and (B) isocyanatereactive component, and they are mixed while stirring for foaming. It is also possible to add the (A) isocyanate component, the (B) isocy ante-reactive component and the (C) additive component simultaneously, and mix them while stirring for reaction.

[0085] During the preparation of polyurethane foam, suitable process parameters such as foaming pressure, foaming temperature and maturation temperature can be selected as needed.

[0086] In the present invention, the reaction between the (A) isocyanate component and the (B) isocyanate-reactive component is an addition polymerization reaction of isocyanate groups with hydroxyl groups. The isocyanate groups may be those contained in the (A) isocyanate component or those contained in the intermediate product of the reaction between the (A) isocyanate component and the (B) isocyanate reactive component. The hydroxyl groups may be those contained in the (B) isocyanate-reactive component or those contained in the intermediate product of reaction between the (A) isocyanate component with the (B) isocyanate reactive component.

[0087] Thus, the present invention also relates to a polyurethane foam, comprising: a reaction product resulting from reaction between the (A) isocyanate component and the (B) isocy ante-reactive component in the presence of the (C) additive component, wherein each component is as defined herein. Article

[0088] In yet another aspect, the present invention also relates to an article comprising a polyurethane foam of the present invention. The article of the present invention may include a support material, an acoustic insulation material, a thermal insulation material, or a filtration material. Preferably, the article of the present invention may include an automobile door panel, an armrest, a seat, a carpet, a mattress, a dashboard, or a steering wheel.

[0089] Beneficial Effects

[0090] The existing polyurethane foam formula systems typically do not have a biobased content, or have a relatively low biobased content. When the biobased content is relatively high, foam maturation and flow would be affected, and the properties of the polyurethane foam would deteriorate. The inventors of the present invention have found that the polyurethane foam prepared using the formula system of the present invention can have a relatively high biobased content, while also demonstrating excellent mold release and process performance. It can achieve the goals of low carbon and high biobased content, and has good application prospects. The polyurethane foam of the present invention has excellent mold release performance, high open-cell content, relatively high density, relatively high tensile strength, elongation at break, tear strength and relatively small compression set.

[0091] Examples

[0092] The present invention will be further described below in conjunction with specific Examples. It is to be understood, however, that these Examples are for illustrative purposes only and do not constitute a limitation on the scope of the present invention.

[0093] The test methods without specific conditions indicated in the following Examples are typically conducted under conventional conditions or as suggested by the manufacturer. Unless otherwise specified or where conflicts arise, the percentages and parts used herein are based on weight.

[0094] Materials, Devices and Test Methods

[0095] Illustration of test methods:

[0096] The functionality of polyols refers to the value determined according to the equation: functionality = hydroxyl value x molecular weight / 56100, wherein the molecular weight is determined by GPC high performance liquid chromatography; Tensile strength: determined according to DIN 53571 standard;

[0097] Elongation at break: determined according to DIN 53571 standard;

[0098] Tear strength: determined according to ISO 34-1 standard;

[0099] Surface hardness: determined using an Asker Durometer Type C;

[0100] Open-cell content: determined according to ASTM D 2856-98 standard.

[0101] Materials used:

[0102] 58IF11 : Isocyanate component, purchased from Covestro Germany;

[0103] 1 OWF 15 : Glycerol -initiated PO / EO-type polyether polyol, with a hydroxyl value of 35 mg KOH / g, a functionality of 3 and an EO content of 13%, purchased from Covestro Germany;

[0104] PU3218: Sorbitol-initiated PO / EO-type polyether polyol, with a hydroxyl value of 29 mg KOH / g, a functionality of 6 and an EO content of 18% by weight, based on the total weight of alkylene oxide in the polyol, purchased from Covestro Germany;

[0105] Desm ophen 7619W: PO / EO-type PHD polyol, with a hydroxyl value of 38 mg KOH / g, a functionality of 3 and an EO content of 18% by weight, based on the total weight of alkylene oxide in the polyol, purchased from Covestro Germany;

[0106] Baycoll AV2113: Aliphatic polyester polyol, with a hydroxyl value of 109 mg KOH / g and a functionality of 2.7, purchased from Covestro Germany;

[0107] Ethacure 100: Crosslinking agent di ethyl toluene diamine, purchased from Albemarle;

[0108] JEFFCAT ZF-10: Polyurethane synthetic catalyst, purchased from Huntsman Chemical Trading (Shanghai) Co., Ltd.;

[0109] Dabco NE1070: Polyurethane synthetic catalyst, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.;

[0110] Foaming agent: Deionized water.

[0111] According to the following Table 1, the raw materials for preparing polyurethane foam were weighed, mixed, stirred and poured into a mold, and then taken out after reaching the predetermined curing time, to obtain the polyurethane foam of Comparative Examples (CE) 1-3 and Example 1. The foam surface state was observed, and the foam properties were tested. The test results are shown in Table 2. Table 1

[0112] * The content of each component is based on the total weight (100%) of the (B) isocyanatereactive component and the (C) additive component.

[0113] NA: untested.

[0114] The polyurethane foam of Example 1 may include up to 35% castor oil, and have a high biobased content and low-carbon environmentally -friendly advantages. Meanwhile, the polyurethane foam also has excellent mold release and process performance, as well as good surface state after demolding (FIG. 4). All performance parameters are excellent. In contrast, the polyurethane foam of Comparative Example (CE) 1 exhibits good surface state (FIG. 1), but does not include castor oil nor have low-carbon environmentally -friendly advantages. The polyurethane foam of Comparative Example (CE) 2 displays inferior surface state after demolding — adhering to the mold and showing surface damage (as depicted in the circle of FIG. 2), compared to that of Example 1. The polyurethane foam of Comparative Example (CE) 3 includes an excessively high amount of castor oil, and exhibits very poor state after demolding — incapable of being completely demolded and showing severe surface damage (FIG. 3).

[0115] Table 3

[0116] * The content of each component is based on the total weight (100%) of the (B) isocyanate- reactive component and the (C) additive component.

[0117] Table 4

[0118] Example 1’ - a repetition of Example 1 - and CE 4 were conducted under ambient conditions slightly different from those of Example 1 and CE 1 - 3. Comparison of the development of surface hardness (Asker C) 7 and 9 min after demolding reveals the inventive polyurethane foam’s improved maturing properties: Example 1’ results in a surface hardness (Asker C) of 25 after 7 min whereas CE 4 only reaches this value after 9 min. Further, comparison of tear strength reveals an improvement of the inventive foam of Example 1 ’ over that of CE 4.

[0119] While specific embodiments of the present invention are described above, it is to be understood by a person skilled in the art that this is merely exemplary, and the protection scope of the present invention is defined by the appended claims. A person skilled in the art may modify or change these embodiments in various ways, without departing from the principles and spirit of the present invention, but these modifications or changes all fall within the protection of the present invention.

Claims

Claims:

1. A polyurethane foam, prepared from a composition comprising (A) an isocyanate component, (B) an isocyanate-reactive component and (C) an additive component, wherein the (A) isocyanate component comprises at least one polyisocyanate; the (B) isocyanate-reactive component comprises:(bl) a polyether polyol, having a functionality of 4 to 8, and a hydroxyl value of 20 to 60 mg KOH / g, preferably 25 to 40 mg KOH / g; optional (b2) a PHD polyol, having a functionality of 2 to 6, preferably 3 to 5, and a hydroxyl value of 20 to 40 mg KOH / g, preferably 35 to 45 mg KOH / g;(b3) a polyester polyol, having a functionality of 2 to 4, preferably 2 to 3, and a hydroxyl value of 80 to 200 mg KOH / g, preferably 100 to 150 mg KOH / g; and(b4) a vegetable oil-based polyol in an amount of 10 to 39% by weight, preferably 10 to 35% by weight, based on the total weight of (B) and (C) components.

2. The polyurethane foam according to claim 1, wherein the content of the (bl) component is 30 to 80% by weight, preferably 40 to 60% by weight, based on the total weight of (B) and (C) components; and / or the content of the (b2) component is of 0 to 25% by weight, preferably 5 to 15% by weight, based on the total weight of (B) and (C) components; and / or the content of (b3) component is 0 to 15% by weight, preferably 2 to 10% by weight, based on the total weight of (B) and (C) components.

3. The polyurethane foam according to claim 1 or 2, wherein the (bl) polyether polyol is a POZEO capped polyether polyol, having an EO content of 10 to 30%, preferably 12 to 25%, by weight, based on the total weight of alkylene oxide in the polyol; and / or the (b2) PHD polyol is a PO / EO capped PHD polyol, having an EO content of 10 to 25%, preferably 13 to 22%, by weight, based on the total weight of alkylene oxide in the polyol.

4. The polyurethane foam according to any one of claims 1 to 3, wherein the (C) additive component comprises one or more of the following:(cl) a foaming agent in an amount of 0.5 to 8.0% by weight, preferably 1.0 to 7.0% by weight, more preferably 1.5 to 6.0% by weight, based on the total weight of (B) and (C) components;(c2) a catalyst in an amount of 0.3 to 2.5% by weight, preferably 0.5 to 2.0% by weight, more preferably 0.8 to 1.8% by weight, based on the total weight of (B) and (C) components;(c3) a crosslinking agent in an amount of 0 to 4.0% by weight, preferably 0.5 to 3.0% by weight, more preferably 0.8 to 2.5% by weight, based on the total weight of (B) and (C) components; and / or the (C) additive component is in an amount of 10% by weight or less, based on the total weight of (B) and (C) components.

5. The polyurethane foam according to any one of claims 1 to 4, wherein the (A) isocyanate component comprises: toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), 1,5- naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), methylcyclohexane diisocyanate (HTDI), 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), p-phenylene diisocyanate (PPDI), p-xylyl diisocyanate (XDI), tetramethyldimethylene diisocyanate (TMXDI), a polymer thereof, a prepolymer thereof, or a combination thereof; and / or the (A) isocyanate component is in an amount of 20 to 150% by weight, preferably 30 to 75% by weight, based on the total weight of (B) and (C) components.

6. The polyurethane foam according to any one of claims 1 to 5, wherein the (b4) vegetable oil-based polyol comprises a vegetable oil, a vegetable oil polyol, a modified product of vegetable oil polyol, or a combination thereof, wherein the vegetable oil preferably comprises peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, palm oil, preferably castor oil; and / or the (b4) vegetable oil-based polyol has a functionality of 2 to 6; and / or the (b4) vegetable oil-based polyol has a hydroxyl value of 60 to 250 mg KOH / g.

7. The polyurethane foam according to any one of claims 4 to 6, wherein the (cl) foaming agent comprises water; and / or the (c2) catalyst comprises a tertiary amine catalyst; and / or the (c3) crosslinking agent comprises 2 to 8 active hydrogens, and is preferably diethyltoluene diamine, diethanolamine or a combination thereof.

8. The polyurethane foam according to any one of claims 1 to 7, wherein the (C) additive component comprises one or more of the following:(c4) a foam stabilizer, (c5) an antioxidant, (c6) a cell opener and (c7) a color paste.

9. The polyurethane foam according to any one of claims 1 to 8, wherein the polyurethane foam is a flexible polyurethane foam.

10. The polyurethane foam according to any one of claims 1 to 9, wherein the polyurethane foam has one or more of the following properties:(1) an open-cell content of >50%, preferably >70%, determined according to ASTM D 2856-98 standard;(2) a density of >10 kg / m3, preferably >80 kg / m3, more preferably >100 kg / m3;(3) a tensile strength of >200 kPa, determined according to DIN53571 standard;(4) an elongation at break of >30%, determined according to DIN 53571 standard;(5) a tear strength of >300 N / m, preferably>2500 N / m, determined according to ISO34-1 standard;(6) a 50% compression set of <10%, determined according to DIN53572 standard.

11. A method for preparing the polyurethane foam according to any one of claims 1 to 10, comprising the following step: mixing and reacting the (A) isocyanate component with the (B) isocyanatereactive component in the presence of the (C) additive component to obtain the polyurethane foam.

12. An article comprising a polyurethane foam according to any one of claims 1 to 10.

13. The article according to claim 12, wherein the article is a support material, an acoustic insulation material, athermal insulation material, or a filtration material; preferably, the article is an automobile door panel, an armrest, a seat, a carpet, a mattress, a dashboard, or a steering wheel.

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