Polyurethane foams, methods of making same, and articles thereof

Abstract

The invention relates to a polyurethane foam which has a high bio-based content. The invention also relates to a preparation method of the polyurethane foam and an article comprising the polyurethane foam.

Description

Technical Field

[0001] The present invention relates to the field of polyurethanes, and more particularly to a polyurethane foam having a high bio-based content. The present invention also relates to a method for preparing the polyurethane foam and an article comprising the polyurethane foam. Background Art

[0002] Polyurethane foams have a very wide range of applications and penetrate almost all sectors of the national economy. They are particularly widely used in furniture, bedding, transportation, refrigeration, construction, insulation, etc. and have become one of the indispensable materials. Polyurethane foams have many advantages such as being porous, having a relatively low density, high specific strength, low thermal conductivity, corrosion resistance, and being easy to manufacture.

[0003] CN111465630A discloses a flexible polyurethane foam which is obtained by reacting toluene diisocyanate with an isocyanate-reactive component in the presence of a blowing agent, a catalyst, and a surfactant. This flexible polyurethane foam has a small compression set rate. CN104341573A relates to a polyurethane foam plastic. Among them, methyl formate is used to replace blowing agents such as chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, alkanes, dichloromethane, water, etc. or a mixture of methyl formate and hydrofluorocarbons, alkanes, dichloromethane, water, etc. is used as a blowing agent to prepare the polyurethane foam plastic.

[0004] Currently, the demand for low-carbon environmental protection and high bio-based content is increasing day by day. For existing polyurethane foam formulation systems, when the bio-based content is high, the foam curing and flow will be affected. Therefore, developing polyurethane foams with both a high bio-based content, excellent demolding performance, and process performance is a difficult problem in this field. Summary of the Invention

[0005] In one 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 (A) the isocyanate component comprises at least one polyisocyanate; (B) the isocyanate-reactive component comprises: (b1) a polyether polyol having a functionality of 3-10, preferably 4-8, and a hydroxyl value of 20-60 mgKOH / g, preferably 25-40 mgKOH / g; optionally present (b2) a polyurea polyol having a functionality of 2-6, preferably 3-5, and a hydroxyl value of 20-40 mgKOH / g, preferably 35-45 mgKOH / g; and optionally present (b3) a polyester polyol having a functionality of 2-4, preferably 2-3, and a hydroxyl value of 80-200 mgKOH / g, preferably 100-150 mgKOH / g; (b4) a vegetable oil-based polyol having a content of 10-39% by weight, preferably 10-35% by weight, based on the total weight of components (B) and (C).

[0006] On the other hand, the present invention also relates to a method for preparing the polyurethane foam of the present invention, which comprises the following steps: in the presence of component (C) additive, mixing component (A) isocyanate with component (B) isocyanate-reactive component, and reacting to obtain the polyurethane foam.

[0007] In yet another aspect, the present invention also relates to an article comprising the polyurethane foam of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 : Surface state diagram of the polyurethane foam of Comparative Example 1.

[0009] Figure 2 : Surface state diagram of the polyurethane foam of Comparative Example 2.

[0010] Figure 3 : Surface state diagram of the polyurethane foam of Comparative Example 3.

[0011] Figure 4 : Surface state diagram of the polyurethane foam of Example 1 of the present invention. DETAILED DESCRIPTION

[0012] General Definitions and Terms

[0013] All publications, patent applications, patents and other references mentioned herein are incorporated herein by reference in their entirety if not otherwise indicated.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the definitions provided herein shall prevail.

[0015] Unless otherwise specified, all percentages, parts, ratios, etc. are by weight. Those skilled in the art should understand that the sum of all components in the composition can suitably be 100%. When a quantity, concentration or other value or parameter is given as a range, a preferred range or a preferred upper limit value and a lower limit value or a specific value, it should be understood that all ranges formed by pairs of any upper limit range or preferred value and any lower limit range or preferred value are specifically disclosed, whether or not the ranges are separately disclosed. Unless otherwise specified, when a numerical range is cited herein, the range is meant to include its endpoints, as well as all integers and fractions within that range.

[0016] The terms "about" and "approximately", when used in conjunction with a numerical variable, generally refer to the value of the variable and all values of the variable within the experimental error (e.g., within the 95% confidence interval for the mean) or within ±10% of the specified value, or within a wider range.

[0017] As used herein, the term "optionally" or "optionally" means that the subsequently described event or situation may or may not occur, and this description includes the occurrence and non-occurrence of the described event or situation, and also includes the case where the subsequently described content is arbitrarily selected. For example, when the content of a certain component in this article is 0%-5%, it means that this component may be optionally present, that is, it covers the case of non-existence (0%) and existence (>0-5%).

[0018] The terms "comprising", "including", "having", "containing" or "involving" and their other variant forms herein are inclusive or open-ended and do not exclude other unlisted elements or method steps. Those skilled in the art should understand that the above terms such as "comprising" cover the meaning of "consisting of". The expression "consisting of" excludes any element, step or component not specified. The expression "consisting essentially of" means that the scope is limited to the specified elements, steps or components, plus optionally present elements, steps or components that do not substantially affect the basic and novel features of the claimed subject matter. It should be understood that the expression "including" covers the expressions "consisting essentially of" and "consisting of". The term "selected from..." means one or more elements in the group listed later, independently selected, and may include combinations of two or more of them.

[0019] As used herein, the term "one or more" or "at least one" means one, two, three, four, five, six, seven, eight, nine or more.

[0020] As used herein, the term "and / or" covers "and" as well as "or". Multiple elements, components or steps defined by "and / or" mean any one of the 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.

[0021] Unless otherwise specified, the terms "its combination", "any combination thereof" and "its mixture" mean a multi-component mixture of the said elements, for example, two, three, four and up to the maximum possible multi-component mixture.

[0022] In addition, if the number of parts or components of the present invention is not indicated before, it means that there is no limit to the number of occurrences (or existence) of the parts or components. Therefore, it should be interpreted as including one or at least one, and the singular form of the part or component also includes the plural, unless the value clearly indicates the singular.

[0023] In this article, the meaning of "a plurality" means two or more, unless otherwise specifically limited. Unless the context clearly indicates, "one" can cover both singular and plural references.

[0024] The functionality of the polyol refers to the value determined according to the industrial formula: functionality = hydroxyl value × molecular weight / 56100; wherein, the molecular weight is determined by GPC high performance liquid chromatography, and the test method can refer to GB / T 21863-2008.

[0025] The hydroxyl value refers to the milligrams of potassium hydroxide equivalent to the hydroxyl groups in 1 g of the sample. The test method can refer to ISO14900-2017.

[0026] When used in the present invention, unless otherwise specified, the functionality and the hydroxyl value both refer to the average functionality and the average hydroxyl value.

[0027] The term "soft" means that the material has a certain elasticity, thus showing a soft property. The cell structure of the soft polyurethane foam is mostly an open-cell structure. The soft polyurethane foam usually has properties such as good elastic recovery, sound absorption, air permeability, heat preservation, etc., and thus is suitable for the application fields of soft materials. The soft material usually can have a surface hardness of 100 or less, for example, 70 or less. The surface hardness can be determined by AskerC test, for example.

[0028] Polyurethane foam

[0029] In one 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.

[0030] (A) Isocyanate Component

[0031] (A) The isocyanate component comprises at least one polyisocyanate. The polyisocyanate can be any aliphatic, alicyclic or aromatic polyisocyanate known for the preparation of polyurethanes. Examples thereof include, but are not limited to: toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), 1,5-naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), methylcyclohexyl diisocyanate (HTDI), 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), p-phenylene diisocyanate (PPDI), p-xylylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI), its polymers or combinations thereof. The functionality of the polyisocyanate useful in the present invention is preferably 2.0-3.5, particularly preferably 2.1-2.9. The viscosity of the polyisocyanate is preferably 5-700 mPa·s, particularly preferably 10-300 mPa·s, measured at 25 °C according to DIN 53019-1-3.

[0032] The isocyanate may include polyisocyanate dimers, trimers, tetramers, pentamers, or combinations thereof.

[0033] In a preferred embodiment of the present invention, the (A) isocyanate component is selected from diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), its polymers, its prepolymers, or combinations thereof.

[0034] The NCO content of the polyisocyanate prepolymer of the present invention can be 15 - 33% by weight, preferably 20 - 32% by weight, more preferably 23 - 30% by weight. The NCO content can be measured by GB / T 12009.4 - 2016.

[0035] The content of the (A) isocyanate component of the present invention can be 20 - 150% by weight, preferably 30 - 75% by weight, such as 71, 72, 73, 74% by weight, based on the total weight of the (B) isocyanate - reactive component and the (C) additive component.

[0036] Blocked isocyanates can also be used as the (A) isocyanate component, which can be prepared by reacting an excess of organic polyisocyanate or combinations thereof with a polyol compound. These compounds and their preparation methods are well - known to those of ordinary skill in the art.

[0037] (B) Isocyanate-Reactive Component

[0038] (B) The isocyanate - reactive component comprises (b1) a polyether polyol, optionally present (b2) a polyurea polyol, optionally present (b3) a polyester polyol, and (b4) a vegetable - oil - based polyol.

[0039] (b1) Polyether polyol

[0040] (B) The isocyanate - reactive component may include a polyether polyol. The polyether polyol can be prepared by known processes, for example, by reacting an alkylene oxide with an initiator in the presence of a catalyst. The catalyst includes but is not limited to basic hydroxides, basic alkoxides, antimony pentachloride, boron trifluoride etherate, or combinations thereof. The alkylene oxide includes but is not limited to tetrahydrofuran, ethylene oxide, propylene oxide, 1,2 - epoxybutane, 2,3 - epoxybutane, styrene oxide, or combinations thereof, and ethylene oxide and / or propylene oxide are particularly preferred. The initiator can be adjusted according to the properties of the polyether polyol such as functionality, viscosity, etc., and is preferably but not limited to polyhydroxy compounds or polyamino compounds. Polyhydroxy 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. Polyamino compounds include but are not limited to ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, diethylenetriamine, toluenediamine, or combinations thereof.

[0041] In one embodiment, the polyether polyol may be propylene oxide / ethylene oxide (PO / EO) capped, for example having a PO and / or EO capping structure. The EO content may be 10 - 30%, preferably 12 - 25%, for example the EO content may be 16, 17, 18, 19%. Correspondingly, the PO content may be 70 - 90%.

[0042] In one embodiment, the functionality of the polyether polyol may be 3 - 10, preferably greater than 3 and less than 10, more preferably 4 - 8, such as 3.1, 3.2, 3.3, 3.4, 3.5, 4, 5, 6, 7, 8, 9, 10, etc. The selection of functionality also needs to be considered for obtaining a suitable reaction product. Too low or too high functionality is not conducive to obtaining the desired product properties.

[0043] In one embodiment, the hydroxyl value of the polyether polyol may be 20 - 60 mgKOH / g, preferably 25 - 40 mgKOH / g, for example 28, 29, 30 mgKOH / g.

[0044] In one embodiment, the content of (b1) the polyether polyol may be 30 - 80% by weight, preferably 40 - 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 (B) the isocyanate-reactive components and (C) the additive components.

[0045] (b2) Polyurea polyol

[0046] In one embodiment, (B) the isocyanate-reactive components may optionally contain a polyurea polyol. Polyurea polyol, also known as polyhydrazodicarbonamide polyol, is a modified polyether polyol. Generally, polyurea polyol is prepared by in-situ polymerization of an isocyanate mixture with an amine group-containing compound such as diamine and / or hydrazine in a base polyol. Preferred base polyols include polyether polyols and polyoxyalkylene polyols, more preferably PO / EO type polyether polyols.

[0047] In the preparation of polyurea polyols, amine group-containing compounds suitable for polymerization with isocyanate mixtures include, but are not limited to, polyamines, hydrazines, hydrazides, ammonia, and mixtures of ammonia and / or urea and formaldehyde. Suitable polyamines include, but are not limited to, primary and / or secondary aliphatic amines, araliphatic amines, cycloaliphatic amines, and aromatic amines of divalent and / or higher valences, such as ethylenediamine; 1,2-propanediamine and 1,3-propanediamine; tetramethylenediamine; hexamethylenediamine; dodecamethylenediamine; trimethyldiaminohexane; N,N'-dimethylethylenediamine; 2,2'-bis(aminopropyl)methylamine; higher homologues of ethylenediamine, such as diethylenetriamine, triethylenetetramine, and tetraethylenepentamine; homologues of propanediamine, such as dipropyltriamine, piperazine, N,N'-bis(aminoethyl)piperazine, triazine, 4-aminobenzylamine, 4-aminophenylethylamine, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 4,4'-diaminodicyclohexylmethane, and 4,4'-diaminodicyclohexylpropane, 1,4-diaminocyclohexane, phenylenediamine, naphthalenediamine; condensates of aniline and formaldehyde; toluenediamine; bis(aminomethyl)benzene, and derivatives monoalkylated on one or two nitrogen atoms of the said aromatic amines. The molecular weight of the polyamine is generally 60 - 10,000 g / mol, preferably 60 - 1,000 g / mol, and most preferably 60 - 200 g / mol.

[0048] The hydrazine used can be hydrazine itself or mono-substituted or N,N'-disubstituted hydrazine. The substituents can be C1-C6 alkyl groups, cyclohexyl groups, or phenyl groups. The molecular weight of hydrazine is generally 32 - 200 g / mol. Suitable hydrazides include hydrazides of divalent or higher valent carboxylic acids, said carboxylic acids including, for example, carbonic acid, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid; esters of hydrazine monocarboxylic acid and diols or polyols and phenols, such as ethylene glycol, propane-1,2-diol, butane-1,2-diol, butane 1,3-diol, butane 1,4-diol, hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, and hydroquinone; and amides of hydrazinemonocarboxylic acid (semicarbazide), such as with the above-mentioned diamines and polyamines. The molecular weight of the hydrazide is generally 90 - 10,000 g / mol, preferably 90 - 1,000 g / mol, more preferably 90 - 500 g / mol.

[0049] Isocyanates or amines, hydrazines, and hydrazides with a functionality greater than 2 can also be used, especially when used together with the corresponding monofunctional compounds.

[0050] In one embodiment, the functionality of the polyurea polyol can be 2 - 6, preferably 3 - 5, for example, 2, 3, 4, 5, 6, etc. The hydroxyl value of the polyurea polyol can be 20 - 40 mgKOH / g, preferably 35 - 45 mgKOH / g, for example, 39 mgKOH / g.

[0051] In one embodiment, the polyurea polyol may be PO / EO-capped, for example having a PO and / or EO capping structure. The EO content may be 10-25%, preferably 13-22%. For example, the EO content may be 16, 17, 18, 19%.

[0052] In one embodiment, the content of the polyurea polyol is 0-25% by weight, preferably 5-15% by weight, such as 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 (B) the isocyanate-reactive component and (C) the additive component.

[0053] As described above, (B) the isocyanate-reactive component may optionally contain a polyurea polyol. That is, the content of the PO / EO type polyurea polyol may be 0.

[0054] (b3) Polyester polyol

[0055] In one embodiment, (B) the isocyanate-reactive component may optionally contain a polyester polyol. The polyester polyol may be an aliphatic or aromatic polyester polyol, preferably aliphatic. The polyester polyol may be prepared by reacting a dicarboxylic acid or a dicarboxylic anhydride with a polyol. The dicarboxylic acids include but are not limited to aliphatic carboxylic acids having 2-12 carbon atoms, and the aliphatic carboxylic acids having 2-12 carbon atoms include but are not limited to succinic acid, malonic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecyl carboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, or a combination thereof. The dicarboxylic anhydrides include but are not limited to phthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, or a combination thereof. The polyols reacting with the dicarboxylic acid or the dicarboxylic anhydride include but are not limited to ethylene glycol, diethylene 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, glycerol, trimethylolpropane, or a combination thereof. The polyester polyol may also include a polyester polyol prepared from a lactone. The polyester polyol prepared from a lactone is preferably but not limited to ε-caprolactone. Preferably, the molecular weight of the polyester polyol may be 200-3000, and the functionality is 2-6, preferably 2-3.

[0056] In one embodiment, the functionality of the polyester polyol may be 2-4, preferably 2-3, such as functionality of 2, 2.7, 3, 4, etc. The hydroxyl value of the polyester polyol may be 80-200 mgKOH / g, preferably 100-150 mgKOH / g, such as 109 mgKOH / g.

[0057] The content of the polyester polyol may be 0-15% by weight, preferably 2-10% by weight, such as 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.

[0058] As described above, the (B) isocyanate-reactive component may optionally contain a polyester polyol. That is, the content of the polyester polyol may be 0.

[0059] (b4) Vegetable oil-based polyol

[0060] (B) The isocyanate-reactive component may contain (b4) vegetable oil-based polyol. 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 are oils extracted from the fruits, seeds, or germ of plants, preferably but not limited to peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, palm oil, especially castor oil. Vegetable oil polyols are polyols initiated from one or several vegetable oils. The initiators for synthesizing vegetable oil polyols include but are not limited to soybean oil, palm oil, peanut oil, low-erucic rapeseed oil, and castor oil. The initiators of vegetable oil polyols can introduce hydroxyl groups through processes such as cracking, oxidation, or transesterification, and then prepare the corresponding vegetable oil polyols through the processes for preparing organic polyols well-known to those skilled in the art. Selecting vegetable oil-based polyols with appropriate functionality and / or hydroxyl value is beneficial to endowing excellent properties to polyurethane foams. In one embodiment, the functionality of the vegetable oil-based polyol is 2-6, such as 2, 3, 4, 5, 6, etc. In another embodiment, the hydroxyl value of the vegetable oil-based polyol is 60-250 mgKOH / g.

[0061] In one embodiment, the content of the vegetable oil-based polyol can be 10-39% by weight, preferably 10-35% 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 (B) the isocyanate-reactive component and (C) the additive component. If the content is too low, the goals of low carbon and environmental protection cannot be achieved; if the content is too high, the demolding and process performance of the polyurethane foam will deteriorate, which is not conducive to use. In the present invention, the reaction that occurs between (A) the isocyanate component and (B) the isocyanate-reactive component is the addition polymerization reaction of the isocyanate group and the hydroxyl group. The isocyanate group can be the isocyanate group contained in (A) the isocyanate component, or the isocyanate group contained in the reaction intermediate of (A) the isocyanate component and (B) the isocyanate-reactive component. The hydroxyl group can be the hydroxyl group contained in (B) the isocyanate-reactive component, or the hydroxyl group contained in the reaction intermediate of (A) the isocyanate component and (B) the isocyanate-reactive component.

[0062] (C) Additive Component

[0063] (C) The additive component can include (c1) a blowing agent, whose main function is to generate gas and form uniformly distributed bubbles. The blowing agent can include water. The amount of (c1) the blowing agent can be 0.5-8.0% by weight, preferably 1.0-7.0% by weight, more preferably 1.5-6.0% by weight, for example, 2.45, 2.5% by weight, based on the total weight of (B) the isocyanate-reactive component and (C) the additive component. Other available blowing agents can include, but are not limited to, fluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrofluorocarbons, and hydrocarbons. If necessary, gas can also be directly introduced into the system to form foam.

[0064] (C) The additive component may include (c2) a catalyst, which is used to catalyze the reaction between isocyanate groups (NCO) and hydroxyl groups (OH). The catalyst can accelerate the foaming of polyurethane, shorten the curing time, and improve the foaming quality. When the amount of the catalyst is small, during the preparation of polyurethane foam, the foaming reaction rate is too low, and it is difficult for gas to escape, resulting in closed-cell polyurethane foam. As the amount of the catalyst increases, the foaming reaction speeds up, and the open-cell rate rises; when the amount of the catalyst is too large, due to the possible excessive foaming reaction, large bubbles may appear and defects may occur, and even the phenomenon of foam collapse may occur. The amount of the catalyst will affect the properties of polyurethane foam, such as tensile strength, tear strength, etc. In the present invention, the catalysts that can be used include, but are not limited to, amine catalysts, preferably tertiary amine catalysts. Amine catalysts include, but are not limited to, triethylamine, tributylamine, dimethylethanolamine, bis(dimethylaminoethyl) ether, triethylenediamine, N-ethy morpholine, N,N,N',N'-tetramethylethylenediamine, pentamethyldiethylenetriamine, dimethylaminopropylenediamine, N,N,N',N'-tetramethyldipropylenetriamine, and one, two or more of the weak acid modified products of the above amine catalysts. The amount of (c2) the catalyst can be 0.3-2.5% by weight, preferably 0.5-2.0% by weight, more preferably 0.8-1.8% by weight, for example 1.15% by weight, based on the total weight of (B) the isocyanate-reactive component and (C) the additive component.

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

[0066] (C) The additive component may further include (c4) a foam stabilizer, which is used to improve the stability of the generated bubbles during the preparation of polyurethane foam, so as to improve the properties of polyurethane foam. Conventional foam stabilizers in the art can be used, such as silicone-based foam stabilizers, fluorine-based foam stabilizers, and other well-known surfactants.

[0067] (C) The additive component may further include (c5) an antioxidant, which can effectively inhibit or reduce the thermal oxidation and photooxidation reaction rates of polyurethane foam, significantly improve the heat resistance and light resistance of polyurethane foam, delay its degradation and aging process, and thus extend the life of polyurethane foam. Conventional antioxidants in the art can be used, including but not limited to: hindered phenolic antioxidants, amine antioxidants, sulfur antioxidants, and phosphate antioxidants, etc.

[0068] (C) The additive component may further comprise (c6) an open-cell agent. The open-cell agent is generally a special type of surfactant, usually containing hydrophobic and hydrophilic segments or groups. The open-cell agent can reduce the surface tension of the foam, promote the rupture of the cells, and increase the open-cell ratio of the polyurethane foam, which gives the polyurethane foam a greater air permeability value. (c6) The open-cell agent may include, but is not limited to, water-soluble emulsifiers, polybutadiene, methyl polysiloxane, poly(propylene oxide-ethylene oxide) copolymer ether, poly(alkylene oxide-polysiloxane) copolymer, etc.

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

[0070] As needed, (C) the additive component may further comprise other additives or auxiliaries, including but not limited to: fillers, internal mold release agents, flame retardants, smoke suppressants, antistatic agents, UV stabilizers, diluents, coupling agents, surface wetting agents, leveling agents, thixotropic agents, plasticizers, foam stabilizers, free radical reaction inhibitors, or combinations thereof.

[0071] In the present invention, the additives can be adjusted as needed. Preferably, substances with pungent odors or high volatility are not used as additives.

[0072] (C) The additive component can be optionally stored together with (A) the isocyanate component and / or (B) the isocyanate-reactive component. (C) The additive component can also be stored independently. When used for preparing polyurethane foam, it is first mixed with (A) the isocyanate component and / or (B) the isocyanate-reactive component, and then polyurethane foam is prepared.

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

[0074] Soft polyurethane foams generally have good elastic recovery, sound absorption, air permeability, heat insulation, etc., and are thus used as, for example, support materials, sound insulation materials, heat insulation materials, or filter materials. In one embodiment, the polyurethane foam of the present invention can be a soft polyurethane foam. In this case, it can also be referred to as "polyurethane soft foam", "flexible polyurethane foam", etc. Soft foams generally have a relatively low surface hardness. The surface hardness can be measured, for example, by the Asker C test. The surface hardness is usually 100 or less, such as 70 or less.

[0075] Properties of Polyurethane Foams

[0076] The polyurethane foam of the present invention has a high bio-based content and excellent demolding performance and processability. In one embodiment, the polyurethane foam of the present invention may have one or more of the following properties: open cell ratio, density, tensile strength, elongation at break, tear strength, compression set.

[0077] The open cell ratio refers to the ratio of the volume of open cells communicating with the outside to the total volume, and can be tested according to standards such as ASTM D 2856-98. The open cell ratio of the polyurethane foam can be ≥50%, preferably ≥70%.

[0078] The density of the polyurethane foam can be ≥10 kg / m 3 , preferably ≥80 kg / m 3 , more preferably ≥100 kg / m 3 .

[0079] Tensile strength characterizes the resistance of a material to the maximum uniform plastic deformation and can be tested according to standards such as DIN53571. In one embodiment, the tensile strength of the polyurethane foam can be ≥200 kPa.

[0080] When a material is pulled until it breaks, the ratio of the elongated length after stretching to the length before stretching is called the elongation at break. The larger the elongation at break, the better the softness and elasticity of the material. It can be tested according to standards such as DIN53571. The elongation at break of the polyurethane foam can be ≥30%.

[0081] Tearing is a phenomenon in which a material is damaged due to the rapid expansion and cracking of cracks or fissures in the material when stressed, and it is one of the characteristic indicators for measuring the material's resistance to damage. Tearing of the polyurethane foam generally develops along the path of least resistance, and the direction of crack development is to choose the route with a weaker internal structure, forming an irregular tearing route through some weak gaps in the structure, thus promoting tearing damage. Tear strength can be tested according to standards such as ISO34-1. The tear strength of the polyurethane foam can be ≥300 N / m, preferably ≥2500 N / m.

[0082] Compression set, also known as compression permanent deformation. Usually, a specimen of known height is compressed to a specified height according to the compression rate requirement, held for a certain time under specified temperature conditions, then the compression is released, and the specimen is allowed to recover in a free state, and the height of the specimen is measured. The smaller the compression set, the better the resilience ability and the stronger the anti-deformation ability of the material. Compression set can be tested according to standards such as DIN53572. The 50% compression set of the polyurethane foam can be ≤10%.

[0083] Preparation method

[0084] On the other hand, the present invention also relates to a method for preparing a polyurethane foam, which may include the following steps: mixing (A) an isocyanate component with (B) an isocyanate-reactive component in the presence of (C) an additive component, and reacting to obtain a polyurethane foam.

[0085] There is no specific limitation on the mixing order of (A) the isocyanate component, (B) the isocyanate-reactive component, and (C) the additive component. Any two components can be mixed first, and then the remaining components can be added. All components can also be added simultaneously and mixed together.

[0086] A suitable mixing order can be selected according to the actual situation. For example, (A) the isocyanate component and (B) the isocyanate-reactive component can be first made into a prepolymer, then (C) the additive component is added, and the mixture is foamed under stirring and cured and aged at a certain temperature. Or a part of (A) the isocyanate component and (B) the isocyanate can be first made into a prepolymer, then (C) the additive component, the remaining (A) the isocyanate component, and (B) the isocyanate are added, and the mixture is foamed under stirring. It is also possible to add (A) the isocyanate component, (B) the isocyanate-reactive component, and (C) the additive component together and react under stirring.

[0087] During the preparation process of the polyurethane foam, suitable process parameters can be selected according to needs, such as foaming pressure, foaming temperature, curing temperature, aging temperature, etc.

[0088] In the present invention, the reaction between (A) the isocyanate component and (B) the isocyanate-reactive component is an addition polymerization reaction of an isocyanate group and a hydroxyl group. The isocyanate group can be the isocyanate group contained in (A) the isocyanate component, or the isocyanate group contained in the reaction intermediate of (A) the isocyanate component and (B) the isocyanate-reactive component. The hydroxyl group can be the hydroxyl group contained in (B) the isocyanate-reactive component, or the hydroxyl group contained in the reaction intermediate of (A) the isocyanate component and (B) the isocyanate-reactive component.

[0089] Therefore, the present invention also relates to a polyurethane foam, which comprises: a reaction product obtained by reacting (A) an isocyanate component and (B) an isocyanate-reactive component in the presence of (C) an additive component, wherein each component is as defined herein.

[0090] Article

[0091] In yet another aspect, the present invention also relates to an article comprising the polyurethane foam of the present invention. The articles of the present invention can include support materials, sound insulation materials, heat insulation materials, or filter materials. Preferably, the articles of the present invention can include automobile door panels, armrests, seats, carpets, mattresses, instrument panels, or steering wheels.

[0092] Advantages

[0093] Existing polyurethane foam formulation systems usually do not contain or contain a low bio-based content. When the bio-based content is high, the foam curing and flow are affected, and the performance of the polyurethane foam deteriorates. The inventors of the present invention have found that the polyurethane foam obtained using the formulation system of the present invention can have a high bio-based content, and at the same time has excellent demolding performance and process performance, can achieve the goal of low carbon and high bio-based content, and has good application prospects. The polyurethane foam of the present invention has good demolding performance, high open cell rate, relatively high density, relatively high tensile strength, elongation at break, tear strength and small compression set.

[0094] Examples

[0095] The present invention will be further described below in conjunction with specific embodiments. However, it should be understood that these embodiments are only used to illustrate the present invention and do not constitute a limitation to the scope of the present invention.

[0096] For the test methods without specific conditions indicated in the following examples, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise stated or in conflict, the percentages and parts used herein are by weight.

[0097] Materials, Instruments and Test Methods

[0098] Description of test methods:

[0099] The functionality of the polyol is a value determined according to the industry formula: functionality = hydroxyl value × molecular weight / 56100; wherein, the molecular weight is determined by GPC high performance liquid chromatography;

[0100] Tensile strength test: Test according to DIN53571 standard;

[0101] Elongation at break test: Test according to DIN53571 standard;

[0102] Tear strength: Test according to ISO34-1 standard;

[0103] Surface hardness: Test using Asker C type hardness tester;

[0104] Open cell rate: Test according to ASTM D 2856-98 standard.

[0105] The raw materials used are as follows:

[0106] 58IF11: Isocyanate component, purchased from Covestro Germany.

[0107] 10WF15: Glycerol-initiated PO / EO polyether polyol, purchased from Covestro Germany, hydroxyl value: 35, functionality: 3, EO content 13%;

[0108] PU3218: Sorbitol-initiated PO / EO polyether polyol, purchased from Covestro Germany, hydroxyl value: 29, functionality: 6, EO content 18%;

[0109] Desmophen 7619W: PO / EO polyurea polyol, purchased from Covestro Germany, hydroxyl value: 38, functionality: 3, EO content 18%;

[0110] Baycoll AV2113: Aliphatic polyester polyol, purchased from Covestro Germany, hydroxyl value: 109, functionality: 2.7;

[0111] Ethacure 100: Crosslinking agent, purchased from Albemarle

[0112] JEFFCAT ZF-10: Polyurethane synthesis catalyst, purchased from Huntsman Chemical Trading (Shanghai) Co., Ltd.;

[0113] Dabco NE1070: Polyurethane synthesis catalyst, purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0114] Foaming agent: Deionized water.

[0115] According to Table 1 below, weigh the raw materials for preparing the polyurethane foam, mix them, stir and pour them into a mold. After reaching the set curing time, take them out to obtain the polyurethane foams of Comparative Examples 1-3 and Example 1. Observe the surface condition of the foams and test the foam properties. The test results are shown in Table 2.

[0116] Table 1

[0117]

[0118] * The content of each component is based on the total weight (100%) of (B) isocyanate-reactive components and (C) additive components.

[0119] Table 2

[0120]

[0121] NA: Not tested.

[0122] The polyurethane foam of Example 1, with the castor oil content up to 35%, has a high bio-based content and has the advantages of low carbon and environmental protection. At the same time, it also has excellent demolding performance and process performance, and the surface state after demolding is good ( Figure 4), with excellent performance parameters. In contrast, although the polyurethane foam in Comparative Example 1 has a good surface state ( Figure 1 ), it does not contain castor oil and does not have the advantage of low-carbon environmental protection. The surface state of the polyurethane foam in Comparative Example 2 after demolding is inferior to that of Example 1. It adheres to the mold, and its surface is damaged ( Figure 2 inside the circle in). The content of castor oil in Comparative Example 3 is too high, and the state after demolding is very poor. It cannot be demolded completely, and the surface is severely damaged ( Figure 3 ).

[0123] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only an example. The protection scope of the present invention is defined by the appended claims. Without departing from the principle and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

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, (A) The isocyanate component comprises at least one polyisocyanate; (B) The isocyanate-reactive component comprises: (b1) a polyether polyol having a functionality of 3 - 10, preferably 4 - 8, and a hydroxyl value of 20 - 60 mgKOH / g, preferably 25 - 40 mgKOH / g; (b2) an optionally present polyurea polyol having a functionality of 2 - 6, preferably 3 - 5, and a hydroxyl value of 20 - 40 mgKOH / g, preferably 35 - 45 mgKOH / g; (b3) an optionally present polyester polyol having a functionality of 2 - 4, preferably 2 - 3, and a hydroxyl value of 80 - 200 mgKOH / g, preferably 100 - 150 mgKOH / g; and (b4) a vegetable oil-based polyol in an amount of 10 - 39% by weight, preferably 10 - 35% by weight, based on the total weight of components (B) and (C).

2. The polyurethane foam of claim 1, characterized in that (b1) the content of the component is 30 - 80% by weight, preferably 40 - 60% by weight, based on the total weight of components (B) and (C); and / or (b2) the content of the component is 0 - 25% by weight, preferably 5 - 15% by weight, based on the total weight of components (B) and (C); and / or (b3) the content of the component is 0 - 15% by weight, preferably 2 - 10% by weight, based on the total weight of components (B) and (C).

3. The polyurethane foam of claim 1 or 2, characterized in that (b1) the polyether polyol is a PO / EO-capped polyether polyol with an EO content of 10 - 30%, preferably 12 - 25%; and / or (b2) the polyurea polyol is a PO / EO-capped polyurea polyol with an EO content of 10 - 25%, preferably 13 - 22%.

4. The polyurethane foam according to any one of claims 1 - 3, characterized in that (C) The additive component comprises one or more of the following: (c1) a blowing agent in an amount of 0.5 - 8.0% by weight, preferably 1.0 - 7.0% by weight, more preferably 1.5 - 6.0% by weight, based on the total weight of components (B) and (C); (c2) a catalyst in an amount of 0.3 - 2.5% by weight, preferably 0.5 - 2.0% by weight, more preferably 0.8 - 1.8% by weight, based on the total weight of components (B) and (C); (c3) a crosslinking agent in an amount of 0 - 4.0% by weight, preferably 0.5 - 3.0% by weight, more preferably 0.8 - 2.5% by weight, based on the total weight of components (B) and (C); and / or (C) The content of the additive component is 10% by weight or less, based on the total weight of components (B) and (C).

5. The polyurethane foam according to any one of claims 1 - 4, characterized in that (A) The isocyanate component includes: toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polyphenylmethane polyisocyanate (pMDI), 1,5-naphthalene diisocyanate (NDI), hexamethylene diisocyanate (HDI), methylcyclohexyl diisocyanate (HTDI), 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate (IPDI), p-phenylene diisocyanate (PPDI), p-xylylene diisocyanate (XDI), tetramethylxylene diisocyanate (TMXDI), its polymers, its prepolymers or their combinations; and / or (A) The content of the isocyanate component is 20 - 150% by weight, preferably 30 - 75% by weight, based on the total weight of components (B) and (C).

6. The polyurethane foam according to any one of claims 1 - 5, characterized in that (b4) The vegetable oil-based polyol includes vegetable oil, vegetable oil polyol, modified product of vegetable oil polyol or their combinations, wherein the vegetable oil preferably includes peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, palm oil, preferably castor oil; and / or (b4) The functionality of the vegetable oil-based polyol is 2 - 6; and / or, (b4) The hydroxyl value of the vegetable oil-based polyol is 60 - 250 mgKOH / g.

7. The polyurethane foam according to any one of claims 4 - 6, characterized in that (c1) The blowing agent includes water; and / or (c2) The catalyst includes a tertiary amine catalyst; and / or (c3) The crosslinking agent contains 2 - 8 active hydrogens, preferably diethyltoluenediamine, diethanolamine or their combinations.

8. The polyurethane foam according to any one of claims 1 - 7, characterized in that (C) The additive component includes one or more of the following: (c4) Foam stabilizer, (c5) Antioxidant, (c6) Cell opener, (c7) Color paste.

9. The polyurethane foam according to any one of claims 1 - 8, characterized in that the polyurethane foam is a flexible polyurethane foam.

10. The polyurethane foam according to any one of claims 1 - 9, characterized in that the polyurethane foam has one or more of the following properties: (1) The open cell ratio ≥ 50%, preferably ≥ 70%, tested according to ASTM D 2856 - 98 standard; (2) The density ≥ 10 kg / m 3 , preferably ≥ 80 kg / m 3 , more preferably ≥ 100 kg / m 3 ; (3) The tensile strength ≥ 200 kPa, tested according to DIN53571 standard; (4) The elongation at break ≥ 30%, tested according to DIN53571 standard; (5) The tear strength ≥ 300 N / m, preferably ≥ 2500 N / m, tested according to ISO34 - 1 standard; (6) The 50% compression set ≤ 10%, tested according to DIN53572 standard.

11. A method for preparing the polyurethane foam according to any one of claims 1 - 10, which comprises the following steps: In the presence of (C) additive component, mixing (A) isocyanate component with (B) isocyanate-reactive component, and reacting to obtain the polyurethane foam.

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

13. The article according to claim 12, wherein, the article comprises a support material, a sound insulation material, a heat insulation material or a filtering material; preferably, the article comprises a car door panel, an armrest, a seat, a carpet, a mattress, an instrument panel or a steering wheel.

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