Thermoplastic polyurethanes and uses thereof

Abstract

The present invention provides a thermoplastic polyurethane obtained from the reaction of a reaction mixture comprising (i) a polyisocyanate comprising an isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (iii) a chain extender. The thermoplastic polyurethanes are useful in a variety of applications, such as for automotive, electronic device, and consumer goods applications.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 341,613, filed on May 13, 2022, the entire contents of which are expressly incorporated herein by reference.

[0003] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0004] not applicable. Technical Field

[0005] The invention relates to a transparent low-yellowing thermoplastic polyurethane with good elasticity and processability, and the preparation and use thereof. Background Art

[0006] Thermoplastic polyurethanes (TPUs) are currently used to manufacture a variety of products for many applications by various melt processing techniques such as injection molding and extrusion. For example, TPUs are commonly used to manufacture sealing strips, gaskets, conduits, wires and cables, and for surface protection of various products such as automotive parts and electronic devices. Such TPUs are usually manufactured by reacting the following components: (1) a hydroxyl-terminated polyether or a hydroxyl-terminated polyester, (2) a chain extender, and (3) an isocyanate compound. These TPUs are segmented polymers with soft segments and hard segments, which give them excellent elastic properties. The soft segments come from isocyanates and hydroxyl-terminated polyethers or polyesters, and the hard segments come from isocyanates and chain extenders. The chain extender is usually one of various diols such as 1,4-butanediol.

[0007] In light-stable transparent TPU films, isocyanate compounds are most commonly used, especially hydrogenated methylene diphenyl diisocyanate (H 12 -MDI). However, in recent years, for H 12 -The demand for MDI has increased significantly due to the increasing demand for light-stable transparent TPU films in the automotive and consumer electronics markets, which has outstripped supply and led to a global shortage of materials. Therefore, it is necessary to find a substitute for H 12 Alternative isocyanate compounds that can replace -MDI without sacrificing the performance properties of the TPU film would be desirable. Summary of the invention

[0008] The present invention describes thermoplastic polyurethanes obtained from the reaction of a reaction mixture comprising: (i) a polyisocyanate comprising isophorone diisocyanate; (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol; and (iii) a chain extender.

[0009] The present invention further discloses a method for making a thermoplastic polyurethane, comprising reacting a reaction mixture of (i) a polyisocyanate comprising isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (3) a chain extender. The thermoplastic polyurethane can be prepared by any known or hereafter developed method for making thermoplastic polyurethane.

[0010] The present invention further provides an article comprising the thermoplastic polyurethane.

[0011] In one embodiment, the article comprises a film that can be used to protect a surface such as a wing, or to bond surfaces such as glass to glass or glass to a polymer. In another embodiment, the article comprises an automotive component. In another embodiment, the article comprises a component of an electronic device such as a cell phone case. In other embodiments, the article is a watch band or a wearable device. In still another embodiment, the article is an eyeglass frame. DETAILED DESCRIPTION

[0012] The present invention generally provides thermoplastic polyurethanes obtained from the reaction of a reaction mixture comprising: (i) a polyisocyanate comprising isophorone diisocyanate; (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol; (iii) a chain extender; and optionally (iv) one or more additives. The thermoplastic polyurethanes of the present invention exhibit a good balance of properties such as high clarity, good elasticity, and little to no yellowing. Such well-balanced properties are at least similar to, if not better than, those of thermoplastic polyurethanes obtained from reaction mixtures containing hydrogenated methylene diphenyl diisocyanate. Thus, thermoplastic polyurethanes are suitable for use in a variety of applications, such as automotive applications (e.g., interior and exterior parts, including but not limited to dashboard consoles, switch handles, radio controls, dome lights, roof components, paint protection films), electronic devices (e.g., cell phone cases), consumer products (e.g., eyeglass frames, watch bands, wearable devices), surface protection applications (e.g., films for wind turbine blades, films for leading edge substrates on airfoils, such as wings, rotor blades, and propeller blades), and as components of laminated glass in architectural, military, security, and aerospace applications.

[0013] If it appears in this article, the term "includes / comprising" and its derivatives are not intended to exclude the presence of any additional components, steps or procedures, whether or not disclosed in this article. For the avoidance of any doubt, all compositions claimed herein using the term "includes / comprising" may include any additional additives, adjuvants or compounds unless otherwise specified. In contrast, if it appears in this article, the term "essentially consisting of..." excludes any other components, steps or procedures from the scope of any subsequent description, except those that are not necessary for operability; and if used, the term "consisting of..." excludes any components, steps or procedures that are not specifically described or listed. Unless otherwise specified, the terms "or" and "and / or" refer to individual enumerated members and any combination thereof. For example, the expressions A or B and A and / or B refer to only A, only B, or both A and B.

[0014] The articles "a" and "an" are used herein to refer to one or more than one (i.e., at least one) grammatical object of the article. For example, "a polyisocyanate" means one polyisocyanate or more than one polyisocyanate. The expressions "in one embodiment", "according to one embodiment", etc. generally mean that the features, structures or characteristics following the expression are included in at least one embodiment of the present invention, and may be included in more than one embodiment of the present invention. Importantly, these expressions do not necessarily refer to the same embodiment. If the specification states that a component or feature "may", "can", "could" or "might" be included or have a certain characteristic, it is not required that the component or feature be included or have the characteristic.

[0015] The terms "preferred" and "preferably" refer to embodiments that may provide certain benefits in certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not applicable, and is not intended to exclude other embodiments from the scope of the present invention.

[0016] As used herein, the term "about" may allow a certain degree of variation in a value or range, for example, it may be within 10%, within 5%, or within 1% of a stated limit of a stated value or range.

[0017] Values ​​expressed in range format should be interpreted in a flexible manner to include not only the values ​​explicitly described as range limits, but also all individual values ​​or subranges encompassed within the range, as if each value and subrange were explicitly described. For example, a range such as 1 to 6 should be considered to have explicitly disclosed subranges such as 1 to 3, 2 to 4, 3 to 6, etc., as well as individual values ​​within the range, such as 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range.

[0018] In the methods described herein, without departing from the principles of the present invention, the actions may be performed in any order, except where a timing or sequence of operations is explicitly described. In addition, the actions specified may be performed simultaneously, except where the language explicitly requires that they be performed separately. For example, the required action of performing X and the required action of performing Y may be performed simultaneously in a single operation, and the resulting method will fall within the textual scope of the required method.

[0019] The term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0020] "Isocyanate index" or "NCO index" or "index" refers to the ratio of NCO groups present in a formulation relative to isocyanate-reactive hydrogen atoms, given as a percentage: [NCO] x 100 / [active hydrogen] (%).

[0021] The term "hydroxyl value" refers to the concentration of hydroxyl groups that can react with isocyanate groups per unit weight of polyol. The hydroxyl value is reported in mg KOH / g and can be measured according to standard ASTM D1638.

[0022] The term "average functionality" or "average hydroxyl functionality" of a polyol refers to the average number of OH groups per molecule. The average functionality of an isocyanate refers to the average number of -NCO groups per molecule.

[0023] The term "substantially free" refers to a composition in which a particular component or moiety is present in an amount that does not have a substantial effect on the overall composition. In some embodiments, "substantially free" may refer to a composition in which a particular component or moiety is present in an amount of less than about 5% by weight, or less than about 4% by weight, or less than about 3% by weight, or less than about 2% by weight, or less than about 1% by weight, or less than about 0.5% by weight, or less than about 0.1% by weight, or less than about 0.05% by weight, or even less than about 0.01% by weight, based on the total weight of the composition, or a composition in which the particular component or moiety is not present in the corresponding composition.

[0024] According to one embodiment, the present invention provides a thermoplastic polyurethane obtained from the reaction of a reaction mixture comprising the following components: (i) a polyisocyanate comprising isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (iii) a chain extender. The techniques for polymerizing these reactants to synthesize thermoplastic polyurethanes can be carried out using conventional processing equipment, catalysts and methods. However, the polymerization is carried out in a manner that will produce the desired characteristics or properties of the thermoplastic polyurethane. The type and level of the polyisocyanate, aliphatic polyol and chain extender or a combination thereof can be adjusted to obtain a set of desired physical and chemical properties of the synthesized polyurethane. Polymerization techniques that can be used to make the thermoplastic polyurethane of the present invention include conventional methods such as reactive extrusion, batch processing, solution polymerization and cast polymerization.

[0025] In one embodiment, the polyisocyanate used to synthesize the thermoplastic polyurethane is an aliphatic polyisocyanate, particularly an aliphatic diisocyanate. In some embodiments, the polyisocyanate of the present invention is substantially free of aromatic diisocyanates.

[0026] In one embodiment, the aliphatic diisocyanate is isophorone diisocyanate. In addition to isophorone diisocyanate, the polyisocyanate may further comprise an aliphatic diisocyanate having the following structure:

[0027]

[0028] Wherein R is selected from substituted or unsubstituted (C 1 -C 40 ) alkylene, (C 2 -C 40 ) alkenylene and (C 4 -C 20 ) cycloalkylene. In some embodiments, the diisocyanate is selected from hydrogenated methylene diphenyl diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis(2-isocyanato-ethyl)-4-cyclohexene-1,2-dicarboxylate, or 2,5- or 2,6-norbornane diisocyanate, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanato-methylhexanoate, bis(2-isocyanato-ethyl)fumarate, bis(2-isocyanato-ethyl)carbonate, 2-isocyanato-ethyl-2,6-diisocyanato-hexanoate or mixtures thereof. Dimers and trimers of the above diisocyanates may also be used.In one embodiment, the polyisocyanate is substantially free of any aliphatic diisocyanate other than isophorone diisocyanate.

[0029] The polyisocyanate may be from about 0.5% to about 50% by weight, or from about 10% to about 45% by weight, or from about 25% to about 42% by weight, or less than, equal to, or greater than about 0.5% by weight, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5, 20, 21.5, 22.5, 23.5, 24.5, 25.5, 26.5, 27.5, 28.5, 29.5, 30. 47.5, 48, 49.5, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110 According to various embodiments, the isocyanate index of the reactive mixture is from about 0.95 to about 1.20, or from about 0.97 to about 1.05, or less than, equal to, or greater than about 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, 1.09, 1.10, 1.11, 1.12, 1.13, 1.14, 1.15, 1.16, 1.17, 1.18, 1.19, or 1.20.

[0030] In one embodiment, the polyol component comprises an aliphatic polyester polyol for synthesizing thermoplastic polyurethane. The aliphatic polyester polyol may include any suitable number of hydroxyls. For example, the polyester polyol may include 4 hydroxyls or 3 hydroxyls. The polyester polyol may even include 2 hydroxyls, so that the polyester polyol is a polyester diol. Typically, the aliphatic polyester polyol may be the product of a condensation reaction such as a polycondensation reaction, or it may be manufactured by the ring-opening polymerization of a cyclic ester compound such as ε-caprolactone or γ-butyrolactone.

[0031] In the embodiment where polyester polyol is manufactured according to condensation reaction, the reaction can be carried out between one or more aliphatic carboxylic acids and one or more polyols. Examples of aliphatic carboxylic acids include: adipic acid, sebacic acid, azelaic acid and decamethylene dicarboxylic acid. These acids of a single type can be used, or a combination of two or more types can also be used. Examples of polyols include 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 2,3-butylene glycol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2-methyl-1,3-propanediol. Specific examples of aliphatic polyester polyols include poly(hexamethylene adipate) (PHMA) and poly(butylene adipate) (PBA).

[0032] In another embodiment, the aliphatic polyester polyol is a polylactone polyol, which may be dihydroxy or trihydroxy or tetrahydroxy in nature. Such polyols are prepared by reacting lactone monomers; examples of which are γ-butyrolactone, ε-caprolactone, γ-methyl-ε-caprolactone and ζ-enantholactone, which react with an initiator having at least two reactive hydrogens.

[0033] In one embodiment, the aliphatic polyester polyol is a polycaprolactone polyol. The polycaprolactone polyol can be produced by catalytic polymerization of an excess of ε-caprolactone and an initiator containing at least 2 reactive hydrogens. Initiators include diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, dipropylene glycol, 1,3-propylene glycol, polyethylene glycol, polypropylene glycol, poly(oxyethylene-oxypropylene)-diol, and similar polyalkylene glycols, which are blocked, end-capped or heterogeneous and contain up to about 40 or more alkyleneoxy units in the molecule, 3-methyl-1-5-pentanediol, cyclohexanediol, 4,4'-methylene-bis-cyclohexanol, 4,4'-isopropylidene dicyclohexanol, xylene glycol, 2-(4-hydroxymethylphenyl)ethanol, 1,4-butanediol, and the like; triols such as glycerol, trimethylolpropane, 1,2,6-hexanetriol, triethanolamine, triisopropanolamine, and the like; and tetraols such as erythritol, pentaerythritol, N,N,N',N'-tetra-(2-hydroxyethyl)ethylenediamine, and the like. In some embodiments, the average molecular weight of the polycaprolactone polyol may be from about 290 Da to about 6000 Da, or from about 500 Da to about 4000 Da, or from about 1000 Da to about 3000 Da.

[0034] According to one embodiment, the polyol component comprises an aliphatic polyether diol. The polyether diol can be produced by known methods, for example by anionic polymerization of alkylene oxides, wherein an alkali metal hydroxide (such as sodium hydroxide or potassium hydroxide) or an alkali metal alkoxide (such as sodium methoxide, sodium ethoxide or potassium ethoxide or potassium isopropoxide) is used as a catalyst, and at least one initiator molecule (which contains 2 to 3, preferably 2 reactive hydrogen atoms in bonded form) is added; or by cationic polymerization of one or more alkylene oxides (which have 2 to 4 carbon atoms in the alkylene structural part), wherein a Lewis acid is used as a catalyst. Examples of suitable alkylene oxides are tetrahydrofuran, 1,3-propylene oxide, ethylene oxide and 1,2-propylene oxide. The alkylene oxides can be used alone, in alternating connection or in the form of a mixture. Examples of usable starter molecules are water, organic dicarboxylic acids such as succinic acid and adipic acid, and dihydroxy alcohols such as ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, diethylene glycol, 1,6-hexanediol and 2-methyl-1,5-pentanediol, which preferably optionally contain ether bridges in bonded form. The starter molecules can be used alone or in a mixture. Polytetrahydrofuran (polyTHF) containing hydroxyl groups is suitable and preferred.

[0035] PolyTHF can be synthesized by polymerization of tetrahydrofuran. One or more types of polyTHF can be reacted to form thermoplastic polyurethane. PolyTHF, also known in the art as poly(tetramethylene ether) glycol or poly(tetramethylene oxide), has the following general structure in some embodiments:

[0036]

[0037] wherein n is an integer from about 1 to about 100, alternatively from about 5 to about 75, alternatively from about 5 to about 50, alternatively from about 5 to about 20. Alternatively, in such embodiments, the weight average molecular weight of the polyTHF may be from about 650 Da to about 3000 Da, alternatively from about 1000 Da to about 2750 Da, alternatively from about 625 to about 1675, alternatively from about 950 to about 1050, alternatively from about 1750 to about 1850, alternatively from about 1950 to about 2050, or alternatively from about 2800 to about 3000 g / mol. In some embodiments, the hydroxyl value of the polyTHF may be about 30-1000 mg KOH / g, alternatively about 500-540 mg KOH / g, alternatively about 410-500 mg KOH / g, alternatively about 165-180 mg KOH / g, alternatively about 110 to about 120 mg KOH / g, alternatively about 60-65 mg KOH / g, alternatively about 55-58 mg KOH / g, alternatively about 35-40 mg KOH / g.

[0038] In another embodiment, the polyol component may also include polycarbonate polyols such as hydroxy-terminated polycarbonates, including those prepared by diols and carbonate reaction. Such polycarbonates are linear and have terminal hydroxyl groups, wherein other end groups are substantially excluded. Basic reactants are diols and carbonates. Suitable diols are selected from alicyclic diols and aliphatic diols containing 4 to 40 carbon atoms, and / or even 4 to 12 carbon atoms, and are selected from polyoxyalkylene glycols containing 2 to 20 alkoxy groups per molecule, wherein each alkoxy group contains 2 to 4 carbon atoms. Suitable diols include aliphatic diols containing 4 to 12 carbon atoms such as 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 1,10-decanediol, hydrogenated dilinoleic acid diol, hydrogenated dioleyl diol, 3-methyl-1,5-pentanediol; and alicyclic diols such as 1,3-cyclohexanediol, 1,4-dimethylolcyclohexane, 1,4-cyclohexanediol-, 1,3-dimethylolcyclohexane-, 1,4-endo-methylene-2-hydroxy-5-hydroxymethylcyclohexane, and polyalkylene glycol. Depending on the desired properties of the final product, the diol used in the reaction can be a single diol or a mixture of diols. Polycarbonate intermediates (hydroxyl terminated) are generally those known in the art and literature. Suitable carbonates are selected from alkylene carbonates containing 5- to 7-membered rings. Suitable carbonates used herein include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-ethylene carbonate, 1,3-pentenyl carbonate, 1,4-pentenyl carbonate, 2,3-pentenyl carbonate and 2,4-pentenyl carbonate. Likewise, suitable herein are dialkyl carbonates and alicyclic carbonates. Each alkyl group of dialkyl carbonates may contain 2 to 5 carbon atoms, and specific examples thereof are diethyl carbonate and dipropyl carbonate. Each ring structure of alicyclic carbonates, particularly dialicyclic carbonates, may contain 4 to 7 carbon atoms. Various polycarbonate intermediates generally have a number average molecular weight determined by terminal functional group detection, and the average molecular weight is greater than about 700 Da, such as about 700 Da to about 10000 Da, about 1000 Da to about 5000 Da, or about 1000 Da to about 2500 Da.

[0039] In some embodiments, the polyol component may include a mixture of polyols. For example, in one embodiment, the polyol component may include a mixture of polylactone polyols and aliphatic polyether diols. In other embodiments, the polyol component may be substantially composed of polylactone polyols. In another embodiment, the polyol component may be composed of polylactone polyols. In still other embodiments, the polyol component may be substantially composed of aliphatic polyether diols. In some embodiments, the polyol component may be composed of aliphatic polyether diols. In other embodiments, the polyol component may be substantially free of polycarbonate polyols.

[0040] In one embodiment, the polyol component may be from about 30% to about 70% by weight, or from about 35% to about 65% by weight, or from about 40% to about 60% by weight, or less than, equal to, or greater than about 30%, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, or 68% by weight of the total weight of the reaction mixture.

[0041] Thermoplastic polyurethanes are also made using chain extenders. Such chain extenders include diols, triols, diamines, and combinations thereof. In some embodiments, the molecular weight of the chain extender may be up to about 500 Da or up to about 300 Da, such as at least about 35-500 Da.

[0042] One or more short chain polyols having 2 to 20, or 2 to 12, or 2 to 10, or 2 to 8 carbon atoms can be used as chain extenders in the reaction mixture to increase the molecular weight of the thermoplastic polyurethane. Examples of chain extenders include, but are not limited to, low aliphatic polyols and short chain aromatic diols having a molecular weight of less than 500 Daltons or less than 300 Daltons. Suitable chain extenders include organic diols (including glycols) having a total of 2 to about 20 carbon atoms, such as alkane diols, alicyclic diols, alkyl aryl diols, and the like. Exemplary alkane diols include ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, (BDO), 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, propylene glycol, dipropylene glycol, 1,6-hexanediol, 1,7-heptanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, tripropylene glycol, triethylene glycol, and 3-methyl-1,5-pentanediol. Examples of suitable cycloaliphatic diols include 1,2-cyclopentanediol and 1,4-cyclohexanedimethanol (CHDM). Examples of suitable aryl diols and alkylaryl diols include hydroquinone bis(1,3-hydroxyethyl) ether (HQEE), 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 1,2,3-trihydroxybenzene, 1,2-bis(hydroxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, 1,3-bis(2-hydroxyethyl)benzene, 1,2-bis(2-hydroxyethoxy)benzene, 1,4-bis-(2-hydroxyethoxy)benzene, bisethoxybisphenol, 2,2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), bisphenol A ethoxylate, bisphenol F ethoxylate, 4,4-isopropylidene diphenol, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane (HEPP), and mixtures thereof.

[0043] Examples of triols include, but are not limited to, glycerol, trimethylolmethane, trimethylolethane, trimethylolpropane, 1,2,4-butanetriol, pentaerythritol, diglycerol, triglycerol and higher condensation products of glycerol, di(trimethylolpropane), di(pentaerythritol), trimethylol isocyanurate, tris(hydroxyethyl)isocyanurate (THEIC), tris(hydroxypropyl)isocyanurate, inositol, sugars such as glucose, fructose or sucrose, sugar alcohols such as sorbitol, mannitol, threitol, erythritol, ribitol, arabitol, xylitol, dulcitol, maltitol, isomalt, and trifunctional or higher functional polyether alcohols based on trifunctional or higher functional alcohols and propylene oxide and / or butylene oxide.

[0044] In one embodiment, the chain extender comprises an aliphatic diol having 2 to 20 carbon atoms, or 2 to 12 carbon atoms, or 2 to 10 carbon atoms, or mixtures thereof. In another embodiment, the chain extender of the present invention consists essentially of or consists of an aliphatic diol having 2 to 20 carbon atoms, or 2 to 12 carbon atoms, or 2 to 10 carbon atoms, or mixtures thereof.

[0045] In one embodiment, the chain extender may be from about 0.5 wt % to about 25 wt %, or from about 2 wt % to about 20 wt %, or from about 5 wt % to about 15 wt %, or less than, equal to, or greater than about 1 wt %, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 wt % of the total weight of the reaction mixture.

[0046] Optionally, it may be desirable to use one or more additives. In one embodiment, the additive may include catalysts such as metal carboxylates and tertiary amines. Examples of metal carboxylate catalysts include stannous octoate, dibutyltin dilaurate, phenylmercuric propionate, lead octoate, ferric acetylacetonate, magnesium acetylacetonate, bismuth neodecanoate, etc. Examples of tertiary amine catalysts include triethyleneamine, triethylenediamine and imidazoles such as dimethylimidazole. Other catalysts such as maleates and acetates, etc. may also be used. The amount of one or more catalysts is low, typically about 50-100 parts by weight per million parts by weight of the final thermoplastic polyurethane polymer formed.

[0047] According to another embodiment, a method for producing thermoplastic polyurethane by reacting a polyol component, a polyisocyanate and a chain extender of a reaction system is provided. The various reactants of the reaction mixture can be combined in any order, although it is preferred to add the polyisocyanate last or simultaneously with the other reactants.

[0048] In addition, thermoplastic polyurethane of the present invention can be mixed with various conventional additives or compounding agents, such as antioxidant, nonionic surfactant, silicon-based surfactant, wax, coloring agent, biocide, fungicide, antimicrobial, antistatic additive, plasticizer, filler, filler, flame retardant, impact modifier, pigment, lubricant, release agent, rheology modifier, UV absorber etc.The level of such conventional additive will depend on the final property and cost of required terminal application, as known to the technical personnel of composite thermoplastic polyurethane field.These other additives can be introduced in polyisocyanate, polyol component or the chain extender of reaction mixture, or directly introduced in reaction mixture to prepare thermoplastic polyurethane, or they can be introduced after thermoplastic polyurethane has been made.In another method, all additives can be mixed with thermoplastic polyurethane and then melted, or they can be directly introduced in the melt of thermoplastic polyurethane.

[0049] The formed thermoplastic polyurethane is a material with a hard segment ratio of at least about 10%. In other embodiments, the hard segment ratio is at least about 20%, or at least about 25%, or at least 30%, or at least about 35%, or at least about 40%, or at least about 45%, or at least about 50%. In other embodiments, the hard segment ratio may be at most about 20%, or at most about 25%, or at most about 30%, or at most about 35%, or at most about 40%, or at most about 45%, or at most about 50%, or at most about 60%. In certain embodiments, the hard segment ratio is about 40% to about 50%. The hard segment refers to the part of the polyurethane formed between the chain extender and the polyisocyanate, and can be estimated by calculating the ratio of the weight of the polyisocyanate and the chain extender to the weight of the thermoplastic polyurethane.

[0050] In some embodiments, the weight average molecular weight of the thermoplastic polyurethane of the present invention can be from about 50,000 Da to about 250,000 Da in one aspect, and from about 100,000 Da to about 200,000 Da in another aspect. The weight average molecular weight can be measured by gel permeation chromatography (GPC) relative to polystyrene standards.

[0051] According to another embodiment, the thermoplastic polyurethane may have an ASTM D-1003 haze value of less than about 10%, or less than about 9.5%, or less than about 9%, or less than about 8.5%, or less than about 8%, or less than about 7.5%, or less than about 7%, or less than about 6.5%, or less than about 6%, or less than about 5.5%, or less than about 5%, or less than about 4.5%, or less than about 4%.

[0052] According to yet another embodiment, the ASTM E313 yellowing index of the thermoplastic polyurethane may be less than 1%. All individual values ​​and subranges of the yellowing index less than 1% are included and disclosed herein; for example, the upper limit of the yellowing index may be 1%, 0.9%, 0.8%, 0.7%, 0.6% or 0.5%. In one embodiment, the lower limit of the yellowing index of the film is 0.1%.

[0053] In yet another embodiment, the thermoplastic polyurethane may have an elongation at break according to ASTM D412 of at least about 365%, or at least about 370%, or at least about 380%, or at least about 390%, or at least about 400%.

[0054] In yet another embodiment, the thermoplastic polyurethane may have a tensile strength according to ASTM D412 of at least about 65 MPa, or at least about 66 MPa, or at least about 68 MPa, or at least about 70 MPa, or at least about 72 MPa, or at least about 75 MPa.

[0055] Thermoplastic polyurethane can be formed into the desired end-use article by any suitable means known in the art, such as any thermoforming or extrusion method. In one embodiment, the article is formed by thermoforming. Thermoforming is a method of forming at least one flexible plastic sheet into a desired shape. An embodiment of the thermoforming sequence is described; however, this should not be construed as limiting the thermoforming method of the thermoplastic polyurethane that can be used in the present invention. First, the extrudate film of the thermoplastic polyurethane (and any other layers or materials) is placed on a shuttle rack to hold it during heating. The shuttle rack is indexed into an oven, which preheats the film before forming. Once the film is heated, the shuttle rack is indexed back into the forming tool. The film is then vacuumed onto the forming tool, held in place, and the forming tool is closed. The forming tool can be a "male" or "female" tool. The tool remains closed to cool the film, and then the tool is opened. The formed laminate is then removed from the tool.

[0056] The present invention also provides articles, wherein the articles are formed by extruding thermoplastic polyurethane. That is, the present invention provides articles, which are manufactured by driving molten thermoplastic polyurethane through a die to form a shape with a fixed cross-section.

[0057] The thermoplastic polyurethane composition of the present invention and any blend thereof can form a monolayer film or a multilayer film. These films can be formed by any conventional technique known in the art, including extrusion, coextrusion, extrusion coating, lamination, blow molding and casting or any combination thereof. The film can be obtained by a flat film or tubular method, which can then be oriented uniaxially in the film plane or in two mutually perpendicular directions. One or more layers of the film can be oriented to the same or different extents in the transverse and / or longitudinal directions. The orientation can be carried out before or after the individual layers are placed together. Typically, the film is oriented in a ratio of at most 15, preferably 5 to 7 in the longitudinal direction (MD), and oriented in a ratio of at most 15, preferably 7 to 9 in the transverse direction (TD). However, in another embodiment, the film is oriented to the same extent in both MD and TD directions.

[0058] In another embodiment, the layer comprising the thermoplastic composition of the present invention or any blend thereof may be combined with one or more other layers. The one or more other layers may be any layer typically included in a multilayer film structure. For example, the one or more other layers may be: (i) a polyolefin comprising C 2 -C 40 Olefins, preferably C 2 -C 20Homopolymers or copolymers of olefins, preferably copolymers of α-olefins with another olefin or α-olefin (ethylene is defined as α-olefin for the purposes of the present invention). Suitable polyolefins also include homopolyethylene, homopolypropylene, copolymers of propylene with ethylene and / or butene, copolymers of ethylene with one or more of propylene, butene or hexene and optionally dienes. Suitable examples include thermoplastic polymers such as ultra-low density polyethylene, very low density polyethylene, linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, isotactic polypropylene, highly isotactic polypropylene, syndiotactic polypropylene, random copolymers of propylene with ethylene and / or butene and / or hexene, elastomers such as ethylene propylene rubber, ethylene propylene diene monomer rubber, chloroprene rubber, and blends of thermoplastic polymers and elastomers, such as thermoplastic elastomers and rubber-toughened plastics; (ii) polar polymers, including homopolymers and copolymers of esters, amides, acetates, anhydrides, C 2 -C 20 Copolymers of olefins such as ethylene and / or propylene and / or butene with one or more polar monomers such as acetates, anhydrides, esters, alcohols and / or acrylic substances. Preferred examples include polyesters, polyamides, ethylene vinyl acetate copolymers and polyvinyl chloride; (iii) cationic polymers, including polymers or copolymers of geminal disubstituted olefins, α-heteroatom olefins and / or styrene monomers. Preferred geminal disubstituted olefins include isobutylene, isopentene, isoheptene, isohexene, isooctene, isodecenes and isododecene. Suitable α-heteroatom olefins include vinyl ethers and vinyl carbazoles, and preferred styrene monomers include styrene, alkyl styrene, p-alkyl styrene, α-methyl styrene, chlorostyrene and brominated p-methyl styrene. Suitable examples of cationic polymers include butyl rubber, isobutylene copolymerized with para-methylstyrene, polystyrene and poly-α-methylstyrene; (iv) other suitable layers, which may be paper, wood, paperboard, metal, metal foils (such as aluminum foil and tin foil), metallized surfaces, glass (including silicon oxide (SiOx) coatings applied by evaporating silicon oxide onto the film surface), fabrics, spunbond fibers and nonwovens (especially polypropylene spunbond fibers or nonwovens), and substrates coated with inks, dyes and pigments.

[0059] The thickness of the film made of thermoplastic polyurethane of the present invention can vary according to the expected application, however, a film with a thickness of 1 to 250 microns may be suitable. Films intended for packaging may be 10 to 60 microns thick. The thickness of the sealant is generally 0.2 to 50 microns. The sealant may be present on both the inner and outer surfaces of the film, or the sealant may be present only on the inner or outer surface.

[0060] The present invention also provides an extruded sheet formed from the thermoplastic polyurethane of the present invention. In one embodiment, the thickness of the sheet is from 10 mils to 1000 mils, such as from 15 mils to 500 mils, and further such as from 20 mils to 100 mils.

[0061] In one embodiment, the film made of the thermoplastic polyurethane of the present invention is used for surface protection. In one embodiment, a surface protection film is provided, which comprises a thermoplastic polyurethane obtained by reacting a reaction mixture comprising the following components: (i) a polyisocyanate comprising isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (iii) a chain extender.

[0062] In another embodiment, the film made of the thermoplastic polyurethane of the present invention is used to produce glass or glass-containing laminates. Thus, a laminate is provided, comprising: a first panel comprising a glass-glass laminate structure; a second panel; and an intermediate layer located between the first panel and the second panel and comprising the thermoplastic polyurethane of the present invention.

[0063] The first panel and the second panel are laminated to each other with an intermediate layer. At least the first panel comprises a glass-glass laminate structure. The glass-glass laminate structure comprises at least a first glass layer and a second glass layer adjacent to the first glass layer. For example, the first glass layer comprises a core layer, and the second glass layer comprises a cladding layer adjacent to the core layer. In some embodiments, the cladding layer comprises a first cladding layer and a second cladding layer, and the core layer is located between the first cladding layer and the second cladding layer. Each of the first glass layer and the second glass layer comprises a glass material, a glass-ceramic material, or a combination thereof. In some embodiments, the first glass layer and / or the second glass layer is a transparent glass layer. In some embodiments, the CTE of the cladding layer is different from that of the core layer. Such a CTE mismatch between the cladding layer and the core layer can achieve a strengthened glass-glass laminate structure with significant damage tolerance. The second panel comprises a glass sheet (e.g., a strengthened or unstrengthened glass sheet), a polar polymer sheet (i.e., a sheet comprising any polar polymer described herein), or another suitable sheet material, or a combination thereof. In some embodiments, the second panel comprises a second glass-glass laminate structure, which can be the same as or different from the glass-glass laminate structure of the first panel.

[0064] Thus, in another embodiment, an article comprising a thermoplastic polyurethane is provided, wherein the thermoplastic polyurethane is obtained by reacting a reaction mixture comprising: (i) a polyisocyanate comprising isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (iii) a chain extender. In one embodiment, the article is a film or coating for protecting a surface or an interlayer of a glass window. In another embodiment, the article is an automotive interior or exterior component, or an electronic device or a consumer product.

[0065] In another embodiment, the thermoplastic polyurethanes of the present invention or any blends thereof can be used to prepare molded products in any molding process. Such molding processes are well known to those skilled in the art and include, but are not limited to, cast molding, cold-formed matching die molding, compression molding, foam molding, injection molding, gas-assisted injection molding, rotational molding, slush molding, transfer molding, vacuum forming, wet lay-up or contact molding, blow molding, extrusion blow molding, injection blow molding, and injection stretch blow molding, or combinations thereof.

[0066] In one embodiment, the thermoplastic polyurethane can be adhered to or on another polymer part in a process called overmolding to form an article. The overmolding process includes the following: (a) a substrate formed from a composition comprising a polar polymer, and (b) a molded coating formed from the thermoplastic polyurethane of the present invention. In one embodiment, the polar polymer is polycarbonate (PC), ABS, PC / ABS, PBT / ABS, nylon, or another thermoplastic polyurethane. The present invention also provides an overmolded article, which includes the following: (a) a substrate formed from the thermoplastic polyurethane of the present invention, and (b) a molded coating formed from a composition comprising a polar polymer.

[0067] In another embodiment, a blow molding operation can be used to fix the thermoplastic polyurethane to the substrate material to form an article. Blow molding is particularly suitable for the manufacture of such applications of closed articles, such as fuel tanks and other fluid containers, playground equipment, outdoor furniture and small closed structures. In one embodiment of the method, the thermoplastic polyurethane is extruded through a multilayer head, and then the uncooled laminate is placed in the parison of the mold. The mold with a convex or concave pattern inside is then closed, and air is blown into the mold to form parts.

[0068] In another embodiment, the article can be manufactured by an injection molding method. In injection molding, the shaped laminate is placed in an injection molding tool. The mold is closed and the substrate material is injected into the mold. The substrate material has a melting temperature of 200-300°C in one embodiment and a melting temperature of 215-250°C in another embodiment, and is injected into the mold at an injection speed of 2-10 seconds. After injection, the material is packaged or kept at a predetermined time and pressure so that the parts are dimensionally and aesthetically correct. The typical time period is 5 to 25 seconds, and the pressure is 1380 to 10400 kPa. The mold is cooled at 10-70°C to cool the substrate. The temperature will depend on the desired gloss and desired appearance. The typical cooling time is 10 to 30 seconds, which depends in part on the thickness. Finally, the mold is opened and the molded composite product is taken out.

[0069] The following examples are provided to illustrate the invention but are not intended to limit its scope. Example

[0070] TPU Synthesis

[0071] Thermoplastic polyurethane (TPU) is prepared by reacting aliphatic diisocyanate (H 12 -MDI or isophorone diisocyanate), polyol components, chain extenders and conventional additives (such as antioxidants, UV stabilizers) are reacted and synthesized by a one-pot method. The reaction mixture is heated to 90°C, then poured into a Teflon-lined mold and placed in an oven at 140°C for 2 hours. The TPU is then pelletized and extruded into a film using a single screw extruder for physical property measurements.

[0072] The tensile properties and tear properties of the film were measured on an Instron machine according to ASTM D412 and D624, respectively. The melting temperature was measured on a Mettler-Toledo thermomechanical analyzer (TMA) at a heating rate of 10°C / min. The glass transition temperature (Tg) was taken from the maximum peak on the loss modulus curve, which was measured in tensile mode using a Q800 dynamic mechanical analyzer (DMA) from TA Instruments. The yellowing index of the film was measured using a BYK colorimeter according to ASTM E313. The haze and light transmittance of the film were measured using a Haze-gard Plus machine from BYK according to ASTM D1003.

[0073] Table 1 shows the polyol components comprising polycaprolactone (PCL) polyols having different molecular weights and isophorone diisocyanate (IPDI) or H 12The properties of TPUs made from polyisocyanates containing IPDI-MDI were compared. The TPU of Example 1 had comparable tensile strength and elongation at break, tear strength, and melting temperature to the TPU of Comparative Example 1, and had a higher glass transition temperature (Tg). The TPU of Example 2 (which employed a higher molecular weight PCL polyol) exhibited a Tg more comparable to that of the TPU of Comparative Example 1. The color, haze, and light transmittance of the TPUs of Examples 1 and 2 were all acceptable, indicating that TPUs made from IPDI can exhibit comparable properties to TPUs made from H 12 -MDI-based TPU has similar low yellowing and high transparency characteristics.

[0074] Table 1. 12 -Comparison of physical properties of PCL-based TPU made from MDI and IPDI

[0075] Then polytetrahydrofuran (polyTHF) was used as the polyol component and H 12 -MDI or IPDI as polyisocyanate to produce TPU. The TPU of Example 3 exhibits comparable properties to the TPU of Comparative Example 2 in terms of tensile strength and elongation at break, tear strength and melting temperature, but has a higher Tg than the TPU of Comparative Example 2 (although still much lower than the typical use temperature of TPU). In addition, the TPU based on polyTHF and IPDI exhibits low yellowing and high transparency properties similar to the TPU of Comparative Example 2.

[0076] Table 2. 12 -Comparison of physical properties of polyTHF-based TPU made from MDI and IPDI

[0077] In conclusion, the above results show that the use of IPDI instead of H 12 -MDI can successfully produce TPU films. Specifically, compared with the use of H 12 Such films may exhibit at least comparable, if not better, performance properties than TPU films produced using poly(ethyleneimine)-MDI.

[0078] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope of the invention is determined by the claims that follow.

Claims

1. A thermoplastic polyurethane obtained from the reaction of a reaction mixture comprising: (i) a polyisocyanate comprising isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (iii) a chain extender.

2. Thermoplastic polyurethane according to claim 1, wherein the aliphatic polyester polyol is obtained from the reaction of one or more aliphatic carboxylic acids with one or more polyols.

3. The thermoplastic polyurethane according to claim 1, wherein the aliphatic polyester polyol is a polylactone polyol.

4. The thermoplastic polyurethane according to claim 3, wherein the polylactone polyol is a polycaprolactone polyol.

5. The thermoplastic polyurethane of claim 4, wherein the polycaprolactone polyol has an average molecular weight of about 1000 Da to about 3000 Da.

6. Thermoplastic polyurethane according to claim 1, wherein the aliphatic polyether polyol is polytetrahydrofuran polyol having the following general structure: wherein n is an integer from about 1 to about 100.

7. The thermoplastic polyurethane of claim 6, wherein the polytetramethylene glycol polyol has a weight average molecular weight of about 1000 Da to about 2750 Da.

8. The thermoplastic polyurethane of claim 1, wherein the chain extender comprises a diol, a triol, or a mixture thereof.

9. The thermoplastic polyurethane of claim 1, wherein the chain extender comprises an aliphatic diol having 2 to 12 carbon atoms.

10. The thermoplastic polyurethane according to claim 1, further comprising one or more additives.

11. An article obtained by injection molding the thermoplastic polyurethane according to claim 1.

12. An article obtained by extruding the thermoplastic polyurethane according to claim 1.

13. A surface protection film comprising the thermoplastic polyurethane according to claim 1.

14. A laminate comprising: a first panel comprising a glass-glass laminate structure, a second panel, and an intermediate layer located between the first panel and the second panel and comprising the thermoplastic polyurethane of claim 1.

15. The laminate of claim 14, wherein the second panel comprises a glass sheet or a polar polymer sheet.

16. An article comprising a thermoplastic polyurethane obtained from the reaction of a reaction mixture comprising: (i) a polyisocyanate comprising isophorone diisocyanate, (ii) a polyol component comprising an aliphatic polyester polyol or an aliphatic polyether polyol, and (iii) a chain extender, and wherein the thermoplastic polyurethane has one or more of the following properties: an ASTM D-1003 haze value of less than about 10%; an ASTM E313 yellowing index of less than 1%; an elongation at break according to ASTM D412 of at least about 365%; and a tensile strength according to ASTM D412 of at least about 65 MPa.

17. The article of claim 16, wherein the polyol component consists essentially of aliphatic polyester polyols.

18. The article of claim 17, wherein the aliphatic polyester polyol is a polycaprolactone polyol.

19. The article of claim 16, wherein the polyol component consists essentially of polyether polyol.

20. The article of claim 19, wherein the polyether polyol is polytetramethylene glycol.

21. The article of claim 16, wherein the article is an automotive interior part or an automotive exterior part or an electronic device.

22. The article of claim 16, wherein the article comprises a surface protection film or a glass-containing laminate.

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