WO2023000288A1

WO2023000288A1 - Polyurethane compositions, products prepared with same

Info

Publication number: WO2023000288A1
Application number: PCT/CN2021/108050
Authority: WO
Inventors: Yanbin FAN; Hongyu Chen
Original assignee: Dow Global Technologies Llc
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2023-01-26

Abstract

A polyurethane composition is provided. The polyurethane composition comprises a polyurethane composition, comprising a polyol component comprising a first polytetramethylene ether glycol, a first polyol different from the first polytetramethylene ether glycol, and at least one chain extender and/or crosslinker; and a polyisocyanate prepolymer derived from the reaction of reactants comprising at least one polyisocyanate compound having at least two isocyanate groups, a second polytetramethylene ether glycol, at least one bisphenol alkoxylate comprising at least two isocyanate-reactive hydrogen-containing groups, and optionally a second polyol different from the second polytetramethylene ether glycol. The polyurethane elastomers prepared by using the polyurethane composition display low internal heat buildup and high tear resistance properties, suitable for use as high density polyurethane elastomer. A tire product prepared from the polyurethane composition is also provided.

Description

POLYURETHANE COMPOSITIONS, PRODUCTS PREPARED WITH SAME

FIELD OF THE INVENTION

The present disclosure relates to a polyurethane composition, a polyurethane elastomer prepared by using the composition, a method for preparing the polyurethane product, a method for improving the performance properties of the polyurethane product. The polyurethane composition exhibits low internal heat buildup and high tear resistance properties, suitable for use as high density polyurethane elastomer, and more specifically for tires of two wheeled transportation vehicles such as bicycles, e-bicycles or scooters. The polyurethane product exhibits excellent properties such as low internal heat buildup, enhanced tear strength, tensile strength, and abrasion resistance.

BACKGROUND TECHNOLOGY

High density elastomeric polyurethanes are polyurethane materials with density ranges of 200-800 kg/m ³ and usually fabricated via a two-component process of reacting a first component mainly comprising polyols and optional additives such as foaming agents, catalysts, surfactants, and etc. with a second component which comprises one or more prepolymer of polyols and isocyanates. The two components are blended at high speed and then transferred into varied molds with desired shapes.

The development of polyurethanes with low internal heat buildup and high tear resistance is significant to applications where periodic deformation of polyurethanes is associated like tires, automotive suspension components (jounce bumpers, top mounts and coil spring isolators) , rail pads and industrial cushioning parts.

Unfortunately, it has been challenging to develop polyurethanes with low internal heat buildup and high tear resistance. Polyurethanes are poor thermal conductors and prone to generate internal heat during periodic deformation, leading to high internal material temperatures. Although significant efforts have been made to reduce the “internal heat buildup” in polyurethanes such as introduction of isocyanurate, oxazolidone, oxamide or borate groups into polyurethanes and using special isocyanates like 1, 5-naphthylene diisocyanate, chemicals with these special groups or special isocyanates are usually costly. On the other hand, significant improvements of tear resistance are generally limited to application of a dominant amount (usually 30-60 wt%) of polyester polyols. However, polyesters are with high viscosity and prone to hydrolytic attack, resulting in poor processability and durability for out-door tire applications, respectively.

For the above reasons, there is a need in the polyurethane manufacture industry to develop a polyurethane composition from non-polyester polyols, whose performance properties as stated above can be improved with an economical way. After persistent exploration, the inventors have surprisingly developed a polyurethane composition which can achieve all of the above targets.

SUMMARY OF THE INVENTION

The present disclosure provides a unique polyurethane composition, a polyurethane product prepared by using the composition, a method for preparing the polyurethane product and a method for improving the performance properties of the polyurethane product.

In a first aspect of the present disclosure, the present disclosure provides a polyurethane composition for making a polyurethane elastomer having a density from 200 to 800 kg/m ³, comprising (A) a polyol component comprising a first polytetramethylene ether glycol, a first polyol different from the first polytetramethylene ether glycol, and at least one chain extender and/or crosslinker; and (B) a polyisocyanate prepolymer derived from the reaction of reactants comprising at least one polyisocyanate compound having at least two isocyanate groups, a second polytetramethylene ether glycol, at least one bisphenol alkoxylate comprising at least two isocyanate-reactive hydrogen-containing groups, and optionally a second polyol different from the second polytetramethylene ether glycol, wherein the amount of the first polytetramethylene ether glycol is in the range of 5-80%by weight based on the total weight of the polyol component (A) , and the amount of the second polytetramethylene ether glycol is in the range of 5-80%by weight based on the total weight of reactants for the polyisocyanate prepolymer (B) ; wherein each of the first and the second polytetramethylene ether glycol has a molecular weight of from 400 to 6000 g/mol; and wherein the amount of the bisphenol alkoxylate is in the range of from 0.5%to less than 15%by weight based on the total weight of reactants for the polyisocyanate prepolymer (B) , and the bisphenol alkoxylate has a molecular weight of 270 to 6000 g/mol.

DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Also, all publications, patent applications, patents, and other references mentioned herein are incorporated by reference.

As disclosed herein, "and/or" means "and, or as an alternative" . All ranges include endpoints unless otherwise indicated. Unless indicated otherwise, all the percentages and ratios are calculated based on weight, and all the molecular weights are number average molecular weights.

According to an embodiment of the present disclosure, the polyurethane composition is a "two-component" , "two-part" or "two-package" composition comprising an isocyanate-reactive component (A) and at least one prepolymer component (B) , wherein the isocyanate-reactive component (A) comprises a first polytetramethylene ether glycol (PTMEG) , a first polyol different from the first PTMEG and at least one crosslinker; wherein the prepolymer comprises free isocyanate group, e.g. at least two free isocyanate groups, and is prepared by reacting at least one polyisocyanate compound comprising at least two isocyanate groups with a second PTMEG, at least one bisphenol alkoxylate end-capped with isocyanate-reactive hydrogen-containing groups, and optionally a second polyol different from the second PTMEG. The isocyanate-reactive component (A) and the prepolymer component (B) are transported and stored separately, combined shortly or immediately before being applied during the manufacture of the polyurethane product, such as solid tire or elastomeric gasket for window-encapsulation applications. Once combined, the isocyanate-reactive groups (particularly, hydroxyl group) in component (A) reacts with the isocyanate groups in component (B) to form polyurethane.

In the context of the present disclosure, the terms “prepolymer” , “polyisocyanate prepolymer” and “polyurethane prepolymer” are used interchangeably and refer to a prepolymer prepared by reacting at least one polyisocyanate compound having at least two isocyanate groups with polytetramethylene ether glycol (PTMEG) and at least one bisphenol alkoxylate end-capped with isocyanate-reactive hydrogen-containing groups, and optionally a polyol different from PTMEG, wherein the prepolymer comprises at least two isocyanate groups and is used for reacting with the isocyanate-reactive component to form the polyurethane elastomer.

In the context of the present disclosure, the terms “polyisocyanate compound” , “polyisocyanate” and “isocyanate compound comprising at least two isocyanate groups” are used interchangeably and refer to an isocyanate having at least two isocyanate groups, wherein the isocyanate is monomeric, dimeric, trimeric or oligomeric (such as having a polymerization degree of 2, 3, 4, 5 or 6) .

Without being limited to any specific theory, it is believed that polytetramethylene ether glycol (PTMEG) and bisphenol alkoxylate end-capped with isocyanate-reactive hydrogen-containing groups are included in at least one of the prepolymer component and the polyol component to incorporate repeating units of PTMEG and bisphenol alkoxylate in the polyurethane main chain of the final polyurethane elastomer, thus the performance properties of the polyurethane product can be effectively improved.

According to various embodiments of the present disclosure, the amount of the first polytetramethylene ether glycol is in the range of 5-80%by weight based on the total weight of the polyol component (A) , such as in the numerical range obtained by combining any two of the following end point values: 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 15wt%, 18wt%, 20wt%, 21wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%, 72wt%, 73wt%, 74wt%, 75wt%, 76wt%, 77wt%, 78wt%, 79wt%, .

According to various embodiments of the present disclosure, the amount of the second polytetramethylene ether glycol is in the range of 5-80%by weight based on the total weight of reactants for the polyisocyanate prepolymer (B) , such as in the numerical range obtained by combining any two of the following end point values: 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 15wt%, 18wt%, 20wt%, 21wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%, 72wt%, 73wt%, 74wt%, 75wt%, 76wt%, 77wt%, 78wt%, 79wt%.

According to various embodiments of the present disclosure, the total amount of the first and second polytetramethylene ether glycol (PTMEG) in the polyurethane composition is at least 10wt%, based on the total weight of the polyurethane composition, such as in the numerical range obtained by combining any two of the following end point values: 11wt%, 12wt%, 15wt%, 18wt%, 20wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt%, 35wt%, 38wt%, 40wt%, 42wt%, 45wt%, 48wt%, 50wt%, 52wt%, 55wt%, 58wt%, 60wt%, 62wt%, 65wt%, 67wt%, 68wt%, 70wt%, 72wt%, 75wt%, 78wt%, 80wt%.

According to various embodiments of the present disclosure, each of the first and second polytetramethylene ether glycol (PTMEG) has a molecular weight of from 400 to 6000 g/mol, and may have a molecular weight in the numerical range obtained by combining any two of the following end point values: 420, 450, 500, 550, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, and 5900 g/mol.

According to various embodiments of the present disclosure, the bisphenol alkoxylate is end-capped with isocyanate-reactive hydrogen-containing groups, preferably hydroxyl group. The bisphenol alkoxylates comprise at least two epoxide groups.

According to various embodiments of the present disclosure, the bisphenol alkoxylate is based on bisphenols and alkoxides having 1-20 carbon atoms. According to an embodiment of the present disclosure, the carbon atom number of the alkoxide may be in the numerical range obtained by combining any two of the following end point values: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19. According to an embodiment of the present disclosure, the bisphenol alkoxylate can be derived from one or more linear or cyclic alkylene oxides selected from propylene oxide (PO) , ethylene oxide (EO) , butylene oxide, tetramethylene glycol, tetrahyfrofuran, 2-methyl-1, 3-propane glycol and mixtures thereof.

According to various embodiments of the present disclosure, bisphenol alkoxylates are made from bisphenols. Suitable bisphenols include, for example, bisphenol F, bisphenol E, bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol FL, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol TMC, bisphenol S or bisphenol Z, mixtures or derivatives of above. According to a preferable embodiment of the present disclosure, the bisphenol alkoxylate is selected from the group consisting of ethoxylated bisphenol A, ethoxylated bisphenol F, ethoxylated bisphenol AP, ethoxylated bisphenol C, ethoxylated bisphenol FL, ethoxylated bisphenol G, ethoxylated bisphenol M, ethoxylated bisphenol P, ethoxylated bisphenol PH, ethoxylated bisphenol TMC, ethoxylated bisphenol Z, propoxylated bisphenol A, propoxylated bisphenol AP, propoxylated bisphenol F, propoxylated bisphenol C, propoxylated bisphenol FL, propoxylated bisphenol G, propoxylated bisphenol M, propoxylated bisphenol P, butoxylated bisphenol A, butoxylated bisphenol AP, butoxylated bisphenol F, butoxylated bisphenol C, butoxylated bisphenol FL, butoxylated bisphenol G, butoxylated bisphenol M, butoxylated bisphenol P or combinations thereof. According to a preferable embodiment of the present disclosure, the bisphenol alkoxylate is derived from propylene oxide and/or ethylene oxide. According to a preferable embodiment of the present disclosure, the bisphenol alkoxylate is Bisphenol A alkoxylate derived from propylene oxide and/or ethylene oxide.

According to various embodiments of the present disclosure, the amount of the bisphenol alkoxylate is in the range of from 0.5%to less than 15%by weight based on the total weight of reactants for the polyisocyanate prepolymer (B) , such as in the numerical range obtained by combining any two of the following end point values: 0.6wt%, 0.8wt%, 1.0wt%, 1.2wt%, 1.5wt%, 1.7wt%, 1.8wt%, 2.0wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.5wt%, 2.6wt%, 2.8wt%, 3.0wt%, 3.2wt%, 3.4wt%, 3.6wt%, 3.8wt%, 4.0wt%, 4.2wt%, 4.4wt%, 4.6wt%, 4.8wt%, 5.0wt%, 6.0wt%, 7.0wt%, 8.0wt%, 9.0wt%, 10.0wt%, 11.0wt%, 12.0wt%, 13.0wt%, 14.0wt%, 14.5wt%, 14.9wt%.

According to various embodiments of the present disclosure, the bisphenol alkoxylate has a molecular weight of 270 to 6000 g/mol, and may have a molecular weight in the numerical range obtained by combining any two of the following end point values: 280, 300, 350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3400, 3500, 3600, 3700, 3800, 3900, 4000, 4100, 4200, 4300, 4400, 4500, 4600, 4700, 4800, 4900, 5000, 5100, 5200, 5300, 5400, 5500, 5600, 5700, 5800, and 5900 g/mol.

In various embodiments, the isocyanate compound having at least two isocyanate groups, i.e. the polyisocyanate compound, refers to an aliphatic, cycloaliphatic, aromatic or heteroaryl compound having at least two isocyanate groups. In a preferable embodiment, the isocyanate compound can be selected from the group consisting of C ₄-C ₁₂ aliphatic polyisocyanates comprising at least two isocyanate groups, C ₆-C ₁₅ cycloaliphatic or aromatic polyisocyanates comprising at least two isocyanate groups, C ₇-C ₁₅ araliphatic polyisocyanates comprising at least two isocyanate groups, and combinations thereof. In another preferable embodiment, suitable polyisocyanate compounds include m-phenylene diisocyanate, 2, 4-toluene diisocyanate and/or 2, 6-toluene diisocyanate (TDI) , the various isomers of diphenylmethanediisocyanate (MDI) , carbodiimide modified MDI products, hexamethylene-1, 6-diisocyanate, tetramethylene-1, 4-diisocyanate, cyclohexane-1, 4-diisocyanate, hexahydrotoluene diisocyanate, hydrogenated MDI, naphthylene-1, 5-diisocyanate, isophorone diisocyanate (IPDI) , or mixtures thereof. According to a preferable embodiment of the present disclosure, the isocyanate compound can be a quasi-prepolymer formed by reacting a monomeric MDI with one or more polyols. According to a preferable embodiment of the present disclosure, the isocyanate compound is at least one aromatic isocyanate as stated above, having a NCO content between 12-32%and a viscosity below 1500 mPa·s at room temperature. Generally, the amount of the isocyanate compound may vary based on the actual requirement of the polyurethane products. For example, as one illustrative embodiment, the content of the isocyanate compound can be from 15 wt%to 60 wt%, or from 20 wt%to 50 wt%, or from 23 wt%to 40 wt%, or from 25 wt%to 35 wt%, based on the total weight of the polyurethane composition.

According to a preferable embodiment of the present disclosure, the amount of the isocyanate compound is properly selected so that the isocyanate group is present at a stoichiometric molar amount relative to the total molar amount of the hydroxyl groups included in the polyol component, the prepolymer component, and any additional additives or modifiers.

According to various embodiments of the present disclosure, the first polyol different from PTMEG used in the polylol component (A) and the optional second polyol different from PTMEG in the prepolymer component (B) are selected from non-polyester polyols with hydroxyl functionality ≥ 1.5 or from 2 to 5, and may have an average hydroxyl functionality in the numerical range obtained by combining any two of the following end point values: 1.6, 17, 18, 1.9, 2.0, 2.1, 2.3, 2.5, 2.8, 3.0, 3.3, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, and 4.9. In various embodiments, the first and/or second polyol different from PTMEG can be a non-polyester polyol, for example, polyether polyols, polyether polymer polyols, polyetherester polyols, polycarbonate polyols, polybutadiene polyols and combinations thereof.

According to a preferable embodiment of the present disclosure, the first polyols different from PTMEG used in the polylol component (A) is in an amount of 5-80%by weight based on the total weight of the polyol component (A) , such as in the numerical range obtained by combining any two of the following end point values: 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 15wt%, 18wt%, 20wt%, 21wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%, 72wt%, 73wt%, 74wt%, 75wt%, 76wt%, 77wt%, 78wt%, 79wt%.

According to a preferable embodiment of the present disclosure, the optional second polyols dfferent from PTMEG used in the prepolymer component (B) is in an amount of 0-80%by weight based on the total weight of the polyol component (A) , such as in the numerical range obtained by combining any two of the following end point values: 1wt%, 2wt%, 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 15wt%, 18wt%, 20wt%, 21wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt%, 35wt%, 36wt%, 37wt%, 38wt%, 39wt%, 40wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%, 50wt%, 51wt%, 52wt%, 53wt%, 54wt%, 55wt%, 56wt%, 57wt%, 58wt%, 59wt%, 60wt%, 61wt%, 62wt%, 63wt%, 64wt%, 65wt%, 66wt%, 67wt%, 68wt%, 69wt%, 70wt%, 71wt%, 72wt%, 73wt%, 74wt%, 75wt%, 76wt%, 77wt%, 78wt%, 79wt%.

According to various embodiments of the present disclosure, the polyols used in the polyol component (A) and the polyols for preparing the prepolymer component (B) do not comprise polyester polyols. The polyurethane composition according to the present disclosure is based on non-polyester polyol system.

According to a preferable embodiment of the present disclosure, the first polyols and the second polyols different from PTMEG are independently selected from the group consisting of a first polyether polyol having a molecular weight from 200 to 8,000 and/or a hydroxyl functionality of 2 to 5, a second polyether polyol having a solid content of 1 to 50%and/or a OH value of 10 to 149 and/or an average hydroxyl functionality of 2 to 5, a polycarbonate polyol having a molecular weight from 200 to 8,000 and/or a hydroxyl functionality of 2 to 5, a polyetherester polyol having a molecular weight of 200 to 8,000 and/or a hydroxyl functionality of 2 to 5, a polybutadiene polyol having a molecular weight of 200 to 8000 and/or a hydroxyl functionality of 2 to 5 and a combination thereof. In a preferable embodiment of the present application, the first polyether polyol is selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly (2-methyl-1, 3-propane glycol) , EO capped propoxylated glycerin triol, and any copolymers thereof, such as poly (ethylene oxide-propylene oxide) glycol. In another preferable embodiment of the present application, the first polyether polyol is a copolymer derived from polyethylene oxide and polypropylene oxide, wherein the amount of polymerization unit derived from the polyethylene oxide is less than 20 wt%, preferably less than 15 wt%, based on the total weight of the polyether polyol. In a preferable embodiment of the present disclosure, the second polyether polyol is a polyether polyol grafted with vinyl group-containing polymer. In a preferable embodiment of the present disclosure, the vinyl group-containing polymer is derived from one or more monomers selected from the group consisting of acrylonitrile, styrene, alkyl (meth) acrylate, vinyl acetate and vinyl chloride.

The reaction between the isocyanate compound and the polyol component, and the reaction between the prepolymer and the polyol component may occur in the presence of one or more catalysts that can promote the reaction between the isocyanate group and the hydroxyl group. Without being limited to theory, the catalysts can include, for example, glycine salts; tertiary amines; tertiary phosphines, such as trialkylphosphines and dialkylbenzylphosphines; morpholine derivatives; piperazine derivatives; chelates of various metals, such as those which can be obtained from acetylacetone, benzoylacetone, trifluoroacetyl acetone, ethyl acetoacetate and the like with metals such as Be, Mg, Zn, Cd, Pd, Ti, Zr, Sn, As, Bi, Cr, Mo, Mn, Fe, Co and Ni; acidic metal salts of strong acids such as ferric chloride and stannic chloride; salts of organic acids with variety of metals, such as alkali metals, alkaline earth metals, Al, Sn, Pb, Mn, Co, Ni and Cu; organotin compounds, such as tin (II) salts of organic carboxylic acids, e.g., tin (II) diacetate, tin (II) dioctanoate, tin (II) diethylhexanoate, and tin (II) dilaurate, and dialkyltin (IV) salts of organic carboxylic acids, e.g., dibutyltin diacetate, dibutyltin dilaurate, dibutyltin maleate and dioctyltin diacetate; zinc (II) salts of organic carboxylic acids, e.g., zinc (II) diacetate, zinc (II) dioctanoate, zinc (II) diethylhexanoate, and zinc (II) dilaurate; bismuth salts of organic carboxylic acids, e.g., bismuth octanoate and bismuth neodecanoate; organometallic derivatives of trivalent and pentavalent As, Sb and Bi and metal carbonyls of iron and cobalt; or mixtures thereof. Tertiary amine catalysts include organic compounds that contain at least one tertiary nitrogen atom and are capable of catalyzing the hydroxyl/isocyanate reaction. The tertiary amine, morpholine derivative and piperazine derivative catalysts can include, by way of example and not limitation, triethylenediamine, tetramethylethylenediamine, pentamethyl-diethylene triamine, bis (2-dimethylaminoethyl) ether, bis (2-dimethylaminopropyl) methylamine, triethylamine, tripropylamine, tributyl-amine, triamylamine, pyridine, quinoline, dimethylpiperazine, piperazine, N-ethylmorpholine, 2-methylpropanediamine, methyltriethylenediamine, 2, 4, 6-tridimethylamino-methyl) phenol, N, N’, N”-tris (dimethyl amino-propyl) sym-hexahydro triazine, or mixtures thereof.

In general, the content of the catalyst used herein is larger than zero and is at most 3.0 wt%, preferably at most 2.5 wt%, more preferably at most 2.0 wt%, based on the total weight of the polyurethane composition.

In various embodiments of the present disclosure, the polyurethane composition comprises one or more additives selected from the group consisting of chain extender, crosslinker, UV absorber, light stabilizer, blowing agent, foam stabilizer, tackifier, plasticizer, rheology modifier, antioxidant, filler, colorant, pigment, water scavenger, surfactant, solvent, diluent, flame retardant, slippery-resistance agent, antistatic agent, preservative, biocide and any combinations of two or more thereof. These additives can be transmitted and stored as independent components and incorporated into the polyurethane composition shortly or immediately before the combination of components (A) and (B) . Alternatively, these additives may be contained in either of components (A) and (B) when they are chemically inert to the isocyanate group or the isocyanate-reactive group.

A chain extender may be present in the reactants that form a foamed or non-foamed polyurethane product. A chain extender is a chemical having two or more isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 300, preferably less than 200 and especially from 31 to 125. The isocyanate reactive groups are preferably hydroxyl, primary aliphatic or aromatic amino or secondary aliphatic or aromatic amino groups. Representative chain extenders include monoethylene glycol (MEG) , diethylene glycol, triethylene glycol, 1, 2-propylene glycol, dipropylene glycol, tripropylene glycol, 1, 4-butanediol, cyclohexane dimethanol, ethylene diamine, phenylene diamine, bis (3-chloro-4-aminophenyl) methane, dimethylthio-toluenediamine and diethyltoluenediamine. According to a preferable embodiment of the present disclosure, the chain extender is a short chain (such as C ₂ to C ₄) polyol exclusively comprising hydroxyl group as the isocyanate-reactive group, and is preferably monoethylene glycol. According to another preferable embodiment of the present disclosure, the chain extender is an aliphatic or cyclo-aliphatic C ₂-C ₁₂ polyol having a hydroxyl functionality of 2.0 to 8.0, such as 3.0 to 7.0, or from 4.0 to 6.0, or from 5.0 to 5.5, and can be selected from the group consisting of ethylene glycol, propane diol, butane diol, pentane diol, hexane diol, 1, 4-cyclohexane dimethanol, and their isomers. According to a preferable embodiment of the present disclosure, the chain extender is contained as part of the component (A) .

One or more crosslinkers also may be present in the reactants that form the foamed or non-foamed polyurethane product. For purposes of this invention, "crosslinkers" are materials having three or more isocyanate-reactive groups per molecule and an equivalent weight per isocyanate-reactive group of less than 300. Crosslinkers preferably contain from 3 to 8, especially from 3 to 4 hydroxyl (including primary hydroxyl, secondary hydroxyl and tertiary hydroxyl) , primary amine, secondary amine, or tertiary amine groups per molecule and have an equivalent weight of from 30 to about 200, especially from 50 to 125. According to a preferable embodiment of the present disclosure, the crosslinker has an isocyanate-reactive hydrogen functionality (i.e. the sum of hydroxyl and amine groups) of 3 to 6, such as 3 to 4, and more preferably comprises at least one amine group (such as primary amine, secondary amine, or tertiary amine group, and more preferably a tertiary amine group) and at least one, more preferably at least two or at least three secondary and/or tertiary hydroxyl groups. According to a more preferable embodiment of the present disclosure, the crosslinker can be selected from the group consisting of diisopropanolamine, triisopropanolamine, N, N, N', N”, N”-pentakis (2-hydroxypropyl) diethylenetriamine, and any combinations thereof. According to another embodiment of the present disclosure, examples of suitable crosslinkers include diethanol amine, monoethanol amine, triethanol amine, mono-, di-or tri (isopropanol) amine, glycerine, trimethylol propane, pentaerythritol, and the like.

Chain extenders and crosslinkers are suitably used in small amounts, as hardness increases as the amount of either of these materials increases. From 0 to 25 parts by weight of a chain extender is suitably used per 100 parts by weight of the polyol component (A) . A preferred amount is from 0.1 to 25, or from 0.5 to 20, or from 1 to 15, or from 2 to 15 parts per 100 parts by weight of the polyol component (A) . From 0 to 10 parts by weight of a crosslinker is suitably used per 100 parts by weight of the polyol component (A) . A preferred amount is from 0 to 5 parts per 100 parts by weight of the polyol component (A) .

A filler may be present in the polyurethane composition. Fillers are mainly included to reduce cost. Particulate rubbery materials are especially useful fillers. Such filler may constitute from 1 to 50%or more of the weight of the polyurethane composition.

Suitable blowing agents include water, air, nitrogen, argon, carbon dioxide and volatile hydrocarbons, hydrofluorocarbons and hydrochlorofluorocarbons with low boiling points of from -30 to 75 ℃. Amounts of blowing agent depend on the requirement of the density of the final microcellular polyurethanes.

A surfactant may be present in the reaction mixture. It can be used, for example, if a cellular tire filling is desired, as the surfactant stabilizes a foaming reaction mixture until it can harden to form a cellular polymer. A surfactant also may be useful to wet filler particles and thereby help disperse them into the reactive composition and the elastomer. Silicone surfactants are widely used for this purpose and can be used here as well. The amount of surfactant used will in general be between 0.02 and 1 part by weight per 100 parts by weight polyol component.

According to a preferable embodiment of the present disclosure, the polyurethane composition comprises one or more antioxidants. Preferably, the antioxidant is preferably included in component A but not in component B. According to a preferable embodiment of the present disclosure, the antioxidant is a substituted phenol type antioxidant, and is more preferably of sterically hindered phenol type antioxidant. According to a preferable embodiment of the present disclosure, the amount of the antioxidant is from 0.3 to 2%by weight, such as from 0.5 to 1%by weight, based on the total weight of the component A.

According to a preferable embodiment of the present disclosure, the polyurethane composition comprises one or more UV absorbers. The UV absorber is preferably included in component B but not in component A. According to a preferable embodiment of the present disclosure, the absorber is a benzotriaole type UV absorber, and is more preferably 2- (2H- benzotriazo-2-yl) -6-dodecyl-4-methyl-phennol. According to a more preferable embodiment of the present disclosure, the amount of the UV absorber is from 0.5 to 2.5%by weight, such as from 1.0 to 1.8%by weight, based on the total weight of the component B.

According to a preferable embodiment of the present disclosure, the polyurethane composition comprises one or more light stabilizers. The light stabilizer is preferably included in component B but not in component A. According to a preferable embodiment of the present disclosure, the light stabilizer is a hindered aliphatic light stabilizer (HALS) , preferably a substituted alicyclic-amine HALS, and more preferably and bis (1, 2, 2, 6, 6-pentamethyl-4-piperidyl) sebacate. According to a more preferable embodiment of the present disclosure, the amount of the light stabilizer is from 0.5 to 2.5%by weight, such as from 1.0 to 1.8%by weight, based on the total weight of the component B.

According to a preferable embodiment of the present disclosure, the polyurethane composition comprises at least one of colorant, pigment and dye. The colorant, pigment and dye can be included in either component A or component B, and are preferably included in component B but not in component A. According to a preferable embodiment of the present disclosure, the colorant, pigment and dye include carbon black, titanium dioxide or isoindolinon. According to a preferable embodiment of the present disclosure, the amount of each of the colorant, pigment and dye is from 0.3 to 3.0%by weight, based on the total weight of the component B. For example, the colorant, pigment or dye can be added as a dispersion in polyol, such as a dispersion in the polyol component.

According to an embodiment of the present application, the polyurethane composition of the present disclosure can be used for preparing non-foamed polyurethane product which is preferably elastomeric. Such a non-foamed polyurethane product can be molded into gaskets suitable for many applications. The gasket can be used, for example, for an automobile or truck, any other type of transportation vehicles including an aircraft, as well as various types of agriculture, industrial and construction equipment. According to another embodiment of the present application, the polyurethane composition of the present disclosure can be used for preparing foamed polyurethane product, or polyurethane foam. For example, the polyurethane foam is applicable to prepare a wide range of tires that can be used in many applications. The tires can be, for example, for a bicycle, a cart such as a golf cart or shopping cart, a motorized or unmotorized wheelchair, an automobile or truck, any other type of transportation vehicles including an aircraft, as well as various types of agriculture, industrial and construction equipment. Large tires that have an internal volume of 0.1 cubic meter or more are of particular interest.

According to various embodiments of the present disclosure, the polyurethane elastomer has a density of at least 100 kg/m ³, such as from 300 to 950 kg/m ³, from 400 to 900 kg/m ³, from 450 to 850 kg/m ³, from 480 to 820 kg/m ³, from 500 to 800 kg/m ³, from 550 to 750 kg/m ³, or from 600 to 700 kg/m ³.

According to a preferable embodiment of the present disclosure, the polyurethane material is prepared by reaction injection molding (RIM) under an index between 90 and 120, wherein index 100 means the molar ratio between isocyanate group and isocyanate-reactive groups is 1.00. In various embodiments, the polyurethane material is prepared by mixing component A and component B at room temperature or at an elevated temperature of 30 to 120 ℃, preferably from 40 to 90 ℃, more preferably from 50 to 70 ℃, for a duration of e.g., 0.1 seconds to 10 hours, preferably from 5 seconds to 3 hours, more preferable from 10 seconds to 60 minutes. Mixing may be performed in a spray apparatus, a mix head, or a vessel. Following mixing, the mixture may be injected inside a cavity, in the shape of a gasket or any other proper shapes. This cavity may be optionally kept at atmospheric pressure or partially evacuated to sub-atmospheric pressure. Alternatively, the mixture may be directly applied onto a glass panel of the motor.

Upon reacting, the mixture takes the shape of the mold or adheres to the substrate to produce polyurethane material which is then allowed to cure, either partially or fully. Suitable conditions for promoting the curing of the polyurethane polymer include a temperature of from about 20℃ to about 150℃. In some embodiments, the curing is performed at a temperature of from about 30℃ to about 120℃. In other embodiments, the curing is performed at a temperature of from about 35℃ to about 110℃. In various embodiments, the temperature for curing may be selected at least in part based on the time duration required for the polyurethane polymer to gel and/or cure at that temperature. Cure time will also depend on other factors, including, for example, the particular components (e.g., catalysts and quantities thereof) , and the size and shape of the article being manufactured.

The description hereinabove is intended to be general and is not intended to be inclusive of all possible embodiments of the invention. Similarly, the examples hereinbelow are provided to be illustrative only and are not intended to define or limit the invention in any way. Those skilled in the art will be fully aware that other embodiments, within the scope of the claims, will be apparent from consideration of the specification and/or practice of the invention as disclosed herein. Such other embodiments may include selections of specific components and constituents and proportions thereof; mixing and reaction conditions, vessels, deployment apparatuses, and protocols; performance and selectivity; identification of products and by-products; subsequent processing and use thereof; and the like; and that those skilled in the art will recognize that such may be varied within the scope of the claims appended hereto.

EXAMPLES

Some embodiments of the invention will now be described in the following Examples. However, the scope of the present disclosure is not, of course, limited to the formulations set forth in these examples. Rather, the Examples are merely inventive of the disclosure.

Unless specified otherwise, the values of each ingredient in the composition in the examples are expressed in parts by weight.

The information of the raw materials used in the examples is listed in the following Table 1:

Table 1. Raw materials used in the examples

In the following Preparation Examples 1-7, Examples 1-3 and Comparative Examples 1-5, polyurethane elastomers and tire samples were synthesized and characterized.

Characterization Technologies for Preparation Examples 1-7, Examples 1-3 and Comparative Examples 1-5:

Viscosities of different prepolymers were determined using viscosity analyzer (CAP, Brookfield) at room temperatures. NCO values were determined according to ASTM D5155. Tear strength was determined on a Gotech AI-7000S1 universal testing machine according to the testing method DIN 53543. Dynamic mechanical analysis (DMA) was performed on a TA RSA G2 analyzer under strain-control mode at a frequency of 1 Hz.

The internal heat buildup (ΔH, J) within a cast polyurethane wheel was proportional to loss compliance (J”, Pa ^-1) as depicted by Equation below.

J″=tan δ·G′ ^-1

ΔH ∝ J”

Therefore, low loss compliance values were used as indicators for good properties of internal heat management. And the lower, the better (loss compliance values <= 2.0 are preferred) . Tear resistance was simply evaluated via measuring the values of tear strength according to DIN 53543.

Preparation Examples 1-7: Synthesis of Prepolymer

Seven different prepolymers were prepared by reacting varied polyol mixtures with MDI according to the following general procedure with the recipes shown in Table 2. Specifically, polyol mixtures were preheated to 60 ℃ for 12 hours before charge into a tank reactor equipped with a vacuum pump and oil bath. MDI (ISONATE M125) and inhibitor (benzoyl chloride) were initially loaded into the reactor and kept at 60 ℃ with agitation. Polyols were then fed into the reactor and temperatures of the systems were kept below 80 ℃ during the feeding process. The mixture was then heated to 85 ℃ and allowed for reaction for 150 min with stirring. After that, the system was cooled down to 50 ℃, followed by addition of ISONATE ^TM 143LP and agitation for another 20 min. Final prepolymer products were obtained and packaged subsequently after qualification of NCO contents and degassing under vacuum for 30 min.

The resultant prepolymer has a NCO content of ca. 19 wt%. The characterization results were summarized in Table 2. Carbodiimide-modified MDI Isonate 143LP was incorporated in the prepolymers to improve their storage stability at low temperature.

Table 2. Recipes and Characterization of the Prepolymers

	Pre. 01	Pre. 02	Pre. 03	Pre. 04	Pre. 05	Pre. 06	Pre. 07
PEBA2000	24.79
PTMEG2000		37.49	34.86	34.29	31.09	24.79	18.50
BPP33	10.00			2.50	5.00	10.00	15.00
BPA			1.00
ISONATE ^TM M125	58.50	55.80	57.43	56.50	57.20	58.50	59.79
ISONATE ^TM 143LP	6.70	6.70	6.70	6.70	6.70	6.70	6.70
Benzoyl Chloride	0.01	0.01	0.01	0.01	0.01	0.01	0.01
Total	100.00	100.00	100.00	100.00	100.00	100.00	100.00

NCO%of Prepolymer	17.85	17.86	-	17.84	17.13	16.94	17.85
Viscosity (mPa*s, 25 ℃)	3500	900	Precipitated	1200	1400	2500	4100

As shown in Table 2, Prepolymer 3 based on straight Bisphenol A failed during the synthesis due to precipitation. Prepolymers 4-7 based on increasing amounts of BPP33 showed increasing viscosities. For efficient mixing during processing, the viscosity of prepolymer should be better ≤ 2500 mPa*s at room temperature. The mixing becomes totally unacceptable when viscosity is ≥ 4000 mPa*s for these prepolymers. Thus, the viscosities of Prepolymer 7 and Prepolymer 1 are unacceptable and not preferred, respectively.

Examples 1-3 and Comparative Examples 1-5: Preparation of Polyurethane Elastomers

Polyol components were made beforehand according to the recipes shown in Table 3 by mixing polyols, chain extenders, catalysts, surfactants, blowing agents and other additives together. The polyurethane-prepolymers synthesized in the above preparation examples were mixed with the polyol components at 50 ℃ and the mixture was injected into a metal mold at 50 ℃ using a low pressure machine (Green) . Reactions between the polyol components and the prepolymers occurred instantly after the mixing, and the molded samples were demolded after being cured at 50℃ for 5 min. The post-cured polyurethane foam samples were stored for at least 24 h at room temperature before testing.

The polyurethane elastomers prepared in Examples 1 to 3 and Comparative Examples 1-5 were formed into sample plates having a density of ca. 600 kg/m ³, and the characterization results were summarized in the following Table 3.

Table 3. Formulations and Characterization of Examples 1 to 3 and Comparative Examples 1-5

Notes:

a. Polyurethane sample failed to be made due to prepolymer precipitation;

b. Polyurethane sample was made with acceptable (not preferred) mixing results, mainly due to the not preferred high viscosity;

c. Polyurethane sample failed to be made due to unacceptable mixing between polyol and prepolymer components.

It can be seen from Table 3 that the samples prepared in Inventive Examples 1-3, which incorporated bisphenol-A propoxylates (BPP33) according to the present disclosure in the polyurethane main chain, successfully reduced the loss compliance values of the polyurethanes by 7%-10%, whereas still maintained the tear resistance at high levels, as compared with that of Comparative Example 1 without the incorporation of BPP33. The improvement of loss compliance value by more than 5%is considered as a significant change, since tires roll thousands and thousands of times when performing rolling tests. Thus even small change in internal heat buildup capability will result in big observable differences in the rolling testing upon many times of rolling. As shown in Comparative Example 5, further increasing BPP33 significantly increased the viscosity of Prepolymer 7, which was not accepted for the processing, leading to failure of sample preparation of the composition.

The comparison between Comparative Example 1 and Comparative Example 2 showed that further increasing the incorporation amount of PTMEG to up to 86%deteriorated both the tear strength and internal heat buildup properties. Comparative Example 3 showed that straight bisphenol-A could not be incorporated into the prepolymer synthesis due to precipitation issue of the prepolymer. The comparison between Comparative Example 4 and Inventive Example 3 showed that, when the prepolymer was prepared from polyester polyols (PEBA2000) , the incorporation of bisphenol-A propoxylates (BPP33) could not reduce the loss compliance value.

In view of the above, only incorporating both bisphenol-A propoxylates (BPP33) and PTMEG in the polyurethane systems could significantly reduce the loss compliance value and improve the internal heat buildup performance as well as maintain a high level of tear resistance.

Claims

A polyurethane composition for making a polyurethane elastomer having a density from 200 to 800 kg/m ³, comprising

(A) a polyol component comprising a first polytetramethylene ether glycol, a first polyol different from the first polytetramethylene ether glycol, and at least one chain extender and/or crosslinker; and

(B) a polyisocyanate prepolymer derived from the reaction of reactants comprising at least one polyisocyanate compound having at least two isocyanate groups, a second polytetramethylene ether glycol, at least one bisphenol alkoxylate comprising at least two isocyanate-reactive hydrogen-containing groups, and optionally a second polyol different from the second polytetramethylene ether glycol;

wherein the amount of the first polytetramethylene ether glycol is in the range of 5-80%by weight based on the total weight of the polyol component (A) , and the amount of the second polytetramethylene ether glycol is in the range of 5-80%by weight based on the total weight of reactants for the polyisocyanate prepolymer (B) ;

wherein each of the first and the second polytetramethylene ether glycol has a molecular weight of from 400 to 6000 g/mol; and

wherein the amount of the bisphenol alkoxylate is in the range of from 0.5%to less than 15%by weight based on the total weight of reactants for the polyisocyanate prepolymer (B) , and the bisphenol alkoxylate has a molecular weight of 270 to 6000 g/mol.
The polyurethane composition according to claim 1, wherein the total amount of the first and the second polytetramethylene ether glycol is in the range of 10-70%by weight based on the polyurethane composition, and

each of the first and the second polytetramethylene ether glycol has a molecular weight of from 500 to 3000 g/mol.
The polyurethane composition according to claim 1, wherein the amount of the bisphenol alkoxylate is in the range of 1-12%by weight based on the total weight of reactants for the polyisocyanate prepolymer, and

the bisphenol alkoxylate has a molecular weight of 270 to 1000 g/mol.
The polyurethane composition according to claim 1, wherein the bisphenol alkoxylate is derived from alkoxides having 1-20 carbon atoms.
The polyurethane composition according to claim 1, wherein the bisphenol alkoxylate is Bisphenol A alkoxylate derived from propylene oxide and/or ethylene oxide.
The polyurethane composition according to claim 1, wherein the polyurethane elastomer has a density from 500-800 kg/m ³.
The polyurethane composition according to claim 2, wherein the polyurethane composition further comprises at least one additive selected from the group consisting of blowing agent, foam stabilizer, anti-foam agent, tackifier, plasticizer, rheology modifier, antioxidant, UV-absorbent, light-stabilizer, catalyst, cocatalyst, filler, colorant, pigment, water scavenger, surfactant, solvent, diluent, flame retardant, slippery-resistance agent, antistatic agent, preservative, biocide and any combinations thereof.
The polyurethane composition according to claim 1, wherein the first polyol different from the first polytetramethylene ether glycol is selected from non-polyester polyols with functionality ≥ 1.5.
A tire product prepared by using the polyurethane composition according to any one of claims 1-8.
The tire product according to claim 9, wherein the tire product is a tire for a vehicle selected from the group consisting of a two wheel device, an e-bike, a bicycle, a scooter, a cart, a wheelchair, an automobile or a truck.