Composition of thermoplastic polyurethane resistant to chemicals and stains

Abstract

The present invention relates to novel thermoplastic polyurethane compositions obtained from the reaction product of an isocyanate component comprising hexamethylene-1,6-diisocyanate, a polyol component, and a chain-extending component comprising an alkylene-substituted spirocyclic compound. The present invention provides thermoplastic polyurethane compositions resistant to chemical degradation and staining.

Description

Composition of thermoplastic polyurethane resistant to chemicals and stains Field of invention The present invention relates to thermoplastic polyurethane compositions that can be used in articles where resistance to chemicals and staining, as well as transparency, are desirable. Background of the invention It is often desirable for articles manufactured using thermoplastic polyurethanes to be resistant to chemical degradation and staining. This can be particularly challenging for articles or materials that are also transparent. Therefore, it is desirable to have thermoplastic polyurethane compositions that are resistant to chemical degradation and staining. Furthermore, in some embodiments, it would be desirable for the thermoplastic polyurethane composition to also be transparent. Document US2003 / 092832 A1 relates to a method for producing a polyurethane resin comprising reacting: (A) a compound having an active hydrogen-containing group, comprising: (A1) a compound having a spiro ring and active hydrogen-containing groups at both ends; and (A2) an aliphatic polycarbonate polyol; (B) a polyisocyanate; and (C) a chain-extending agent. WO 2016 / 105886 A1 refers to thermoplastic polyurethane (TPU) compositions containing alkylene-substituted spirocyclic compounds as a chain extender, aliphatic polyisocyanate, and polyester polyol. Summary of the invention The invention is set forth in the attached claims. The present invention provides a thermoplastic polyurethane composition comprising the reaction product of (1) a polyisocyanate component, wherein the polyisocyanate component comprises hexamethylene-1,6-diisocyanate and contains less than 5 mol% of isocyanates other than hexamethylene-1,6-diisocyanate, (2) a polyol component, wherein the polyol component comprises a polyether polyol, a polycaprolactone polyol, or a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol, and (3) a chain extender component, wherein the chain extender component comprises at least 90 mol% of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof. of these compounds,wherein the alkylene-substituted spirocyclic compound comprises two rings containing 5 to 7 atoms per ring, and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxyl group or an amine, wherein the amine is a primary or secondary amine. In one embodiment, the polyol component may be a polyether polyol. In another embodiment, the polyol component may comprise a polyester polyol as defined in the claims. In another embodiment, the polyol may be selected from poly(tetramethylene ether) glycol, polycaprolactone polyol, or polyethylene butylene adipate, or combinations thereof as defined in the claims. The present invention further provides articles manufactured from any of the thermoplastic polyurethane compositions described herein. The invention also provides a method for increasing the chemical and stain resistance of an article by manufacturing the article using the thermoplastic polyurethane compositions described herein. In particular, any of the thermoplastic polyurethane compositions described above may be used in this method. Detailed description of the invention The thermoplastic polyurethane (TPU) composition of this invention includes the reaction product of (1) a polyisocyanate component, comprising hexamethylene-1,6-diisocyanate and containing less than 5 mol% of isocyanates other than hexamethylene-1,6-diisocyanate, (2) a polyol component, wherein the polyol component comprises a polyether polyol, a polycaprolactone polyol, or a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol, and (3) a chain extender component comprising at least 90 mol% of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof, wherein the compound The alkylene-substituted spirocyclic contains two rings containing 5 to 7 atoms per ring,and where each ring is substituted with an alkylene group containing from 1 to 4 carbon atoms, terminated in a hydroxyl group or an amine, where the amine is a primary or secondary amine. The technique by which these reagents are polymerized to synthesize TPU can be carried out using conventional processing equipment, catalysts, and processes. The polymerization can be carried out in a manner that will result in the desired characteristics or properties of the polymer. Polymerization techniques useful for manufacturing the TPUs of this invention include conventional methods such as reactive extrusion, batch processing, solution polymerization, and cast polymerization. The polyisocyanate component The thermoplastic polyurethane composition of the present invention includes a polyisocyanate component. Isocyanates commonly used to manufacture thermoplastic polyurethane compositions include aliphatic and aromatic diisocyanates. Suitable aliphatic diisocyanates include hexamethylene-1,6-diisocyanate (HDI), isophorone diisocyanate (IPDI), 1,4-cyclohexyl diisocyanate (CHDI), decane-1,10-diisocyanate, lysine diisocyanate (LDI), 1,4-butane diisocyanate (BDI), 1,4-bis(isocyanatomethyl)cyclohexane (1,4-H6XDI), and dicyclohexylmethane-4,4'-diisocyanate (H12MDI). Aromatic diisocyanates are 4,4'-methylenebis(phenylisocyanate) (MDI), m-xylylenediisocyanate (XDI), phenylen-1,4-diisocyanate, naphthalene-1,5-diisocyanate (NDI), diphenylmethane-3,3'-dimethoxy-4,4'-diisocyanate, or toluene diisocyanate (TDI).To prepare thermoplastic polyurethanes, dimers and trimers of the aforementioned diisocyanates can be used, as well as a mixture of two or more diisocyanates. The polyisocyanate component comprises hexamethylene-1,6-diisocyanate and contains less than 5 mol% of isocyanates other than hexamethylene-1,6-diisocyanate. In some embodiments, the polyisocyanate component is substantially free of isocyanates other than hexamethylene-1,6-diisocyanate, such that the polyisocyanate component consists of hexamethylene-1,6-diisocyanate. The polyol component The thermoplastic polyurethane composition of the present invention comprises a polyol component. The polyol component may include polyether polyols or polyester polyols. In one embodiment, the polyol component includes a polyether polyol. Generally, polyether polyols are derived from a diol or polyol having a total of 2 to 15 carbon atoms; in some embodiments, an alkyl diol or glycol is reacted with an ether comprising an alkylene oxide having 2 to 6 carbon atoms, typically ethylene oxide or propylene oxide, or mixtures of these compounds. For example, polyether with hydroxyl functionality can be produced by first reacting propylene glycol with propylene oxide, followed by a subsequent reaction with ethylene oxide. The primary hydroxyl groups resulting from ethylene oxide are more reactive than secondary hydroxyl groups and are therefore preferred.Useful commercial polyether polyols include poly(ethylene) glycol (PEG), which comprises ethylene oxide reacted with ethylene glycol; poly(propylene) glycol, which comprises propylene oxide reacted with propylene glycol; and poly(tetramethylene ether) glycol, which comprises water reacted with tetrahydrofuran, also known as polymerized tetrahydrofuran, and commonly referred to as PTMEG or poly(tetramethylene ether) glycol. Suitable polyether polyols also include polyamide adducts of an alkylene oxide and may include, for example, ethylenediamine adduct, which comprises the reaction product of ethylenediamine and propylene oxide; diethylenetriamine adduct, which comprises the reaction product of diethylenetriamine with propylene oxide; and similar polyamide-type polyether polyols.In one embodiment of the present invention, the polyol component is a polyether polyol, wherein the polyether polyol comprises, essentially consists of, or consists of PTMEG. In another embodiment, the polyol component may comprise a polyester polyol as defined in the claims. The polyester polyols may be produced by (1) an esterification reaction of one or more glycols with one or more dicarboxylic acids or anhydrides or (2) by a transesterification reaction, i.e., the reaction of one or more glycols with esters of dicarboxylic acids. Molar ratios generally in excess of more than one mole of glycol to acid are preferred to obtain linear chains having a preponderance of terminal hydroxyl groups. The dicarboxylic acids of the desired polyester may be aliphatic, cycloaliphatic, aromatic, or combinations thereof.Suitable dicarboxylic acids, which may be used alone or in mixtures, generally have a total of 4 to 15 carbon atoms and include succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, dodecanedioic, isophthalic, terephthalic, cyclohexanedicarboxylic, and the like. Anhydrides of the aforementioned dicarboxylic acids, such as phthalic anhydride, tetrahydrophthalic anhydride, or the like, may also be used. Adipic acid is a preferred acid. Glycols, which are reacted to form a desirable polyester intermediate, may be aliphatic, aromatic, or combinations of both, including any of the glycols described above in the section on the chain extender, and have a total of 2 to 20 or 2 to 12 carbon atoms.Suitable examples include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, 1,4-cyclohexanedimethanol, decamethylene glycol, dodecamethylene glycol, and mixtures of these compounds. In some embodiments, dimeric fatty acids can be used to prepare polyester polyols that can be used to manufacture the TPU compositions useful in the present invention. Examples of dimeric fatty acids that can be used to prepare polyester polyols include Priplast™ polyester glycols / polyols marketed by Croda and Radia® polyester glycols marketed by Oleon. The polyol component of TPU compositions may also comprise one or more polycaprolactone polyester polyols. The polycaprolactone polyester polyols useful in the technology described herein include polyester diols derived from caprolactone monomers. These polycaprolactone polyester polyols are terminated by primary hydroxyl groups. Suitable polycaprolactone polyester polyols may be manufactured from β-caprolactone and a bifunctional initiator such as diethylene glycol, 1,4-butanediol, monoethylene glycol, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol, or any combination of these compounds or any glycols and / or diols known to those skilled in this field. In some embodiments, the polycaprolactone polyester polyols are linear polyester diols derived from caprolactone monomers.Examples of commercially available polycaprolactone polyols include CAPA™ 2202A, a linear polyester diol with a numerical average molecular weight (Mn) of 2000, and CAPA™ 2302A, a linear polyester diol with an Mn of 3000, both marketed by Perstorp Polyols Inc. These materials may also be described as polymers of 2-oxepanone and 1,4-butanediol. In one embodiment of the present invention, the polyol component is a polyester polyol comprising, essentially consisting of, or consisting of polycaprolactone polyol. In some embodiments, the polyol component may be a polyether or polyester as described above, but it may also comprise a copolymeric polyether polyol or mixtures of copolymeric polyether polyols and / or polyether polyols. The copolymeric polyether polyol is a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol. The chain extender component The chain-extending component of the present invention comprises an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof, and each ring is substituted with an alkylene group containing from 1 to 4 carbon atoms, terminated in a hydroxy group or an amine, wherein the amine is a primary or secondary amine. In one embodiment, the alkylene-substituted spirocyclic compound is a spiroheterocycle containing two heteroatoms in each ring, the heteroatoms being oxygen, nitrogen, sulfur, or phosphorus. In another embodiment, the alkylene-substituted spirocyclic compound is a spiroheterocycle containing two heteroatoms in each ring, the heteroatoms being oxygen or nitrogen.In one embodiment, the alkylene-substituted spirocyclic compound is a spiroheterocycle containing 2 heteroatoms in each ring, and the heteroatoms are oxygen. In one embodiment, the alkylene-substituted spirocyclic compound has the following structural formula: wherein each X is independently selected from O, CHR2, NR2, S, PR2, wherein each R2 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms, each R1 is an alkylene containing from 1 to 4 carbon atoms, which may be linear or branched, and each Z is selected from -OH or -NHR3, wherein R3 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms, wherein a, b, c, d, e, f, g, and h are each independently an integer from 0 to 2 provided that the sum of a, b, c, d, e, f, g, and h is from 1 to 3 and the sum of e, f, g, and h is from 1 to 3. In one embodiment, a equals ag, b equals ah, c equals a, and d equals f. In one embodiment, all X are identical.In one embodiment, all X are selected identically from either O or NR2, wherein R2 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms, a equals ag, b equals ah, c equals ae and d equals f. In one embodiment, the spirocyclic dialkylene compound contains two 6-membered rings, X being independently selected from either O or NR2, wherein R2 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms, R1 is an alkylene containing from 1 to 4 carbon atoms, Z is -OH or NH2, and either (i) a is 0, b is 1, c is 1, d is 0, e is 1, f is 0, g is 0 and h is 1, or (ii) a is 1, b is 0, c is 0, d is 1, e is 0, f is 1, g is 1 and h is 0.In one embodiment, the spirocyclic dialkylene compound contains two 6-membered rings, X being identically selected from O or NR2, wherein R2 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms, R1 is an alkylene containing from 1 to 4 carbon atoms, Z is -OH or NH2, and either (i) a is 0, b is 1, c is 1, d is 0, e is 1, f is 0, g is 0 and h is 1, or (ii) a is 1, b is 0, c is 0, d is 1, e is 0, f is 1, g is 1 and h is 0. In one embodiment, the spirocyclic dialkylene compound contains two 6-membered rings, X is O, R1 is 1,1-dimethylethyl, Z is -OH and either (i) a is 0, b is 1, c is 1, d is 0, e is 1, f is 0, g is 0 and h is 1, or (ii) a is 1, b is 0, c is 0, d is 1, e is 0, f is 1, g is 1 and h is 0. In one embodiment, the alkylene-substituted spirocyclic compound has the following structural formula: wherein each X is independently selected from O, CHR2, NR2, S, PR2, wherein each R2 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms, each R1 is an alkylene containing from 1 to 4 carbon atoms, which may be linear or branched, and each Z is selected from -OH or -NHR3, wherein R3 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms. In one embodiment, X is identically selected from O, CHR2, NR2, S, PR2, wherein each R2 represents a hydrogen atom or an alkyl group containing from 1 to approximately 6 carbon atoms. In one embodiment, X is O, R1 is 1,1-dimethylethyl, and Z is -OH. In one embodiment, the chain-extending component comprises an alkylene-substituted spirocyclic compound as described herein and contains less than 10 mol% of a chain coextender other than the alkylene-substituted spirocyclic compound. The chain coextenders may include aliphatic or cycloaliphatic diamines or glycols having 2 to 20, 2 to 12, or 2 to 10 carbon atoms, or combinations thereof.Examples of chain coextensiles include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,4-butanediol (BDO), 1,6-hexanediol (HDO), 1,3-butanediol, 1,5-pentanediol, neopentyl glycol, 1,4-cyclohexanedimethanol (CHDM), hexamethylenediol, heptanediol, nonanediol, dodecanediol, 2-ethyl-1,3-hexanediol, 2,2,4-trimethylpentane-1,3-diol, 1,4-cyclohexanedimethylol, 3-methyl-1,5-pentanediol, ethylenediamine, butanediamine, hexamethylenediamine, 2-butyl-2-ethyl-1 3-propanediol, and similar compounds, as well as mixtures of these compounds. In one embodiment, the chain-extending component is substantially free of chain co-extenders other than the alkylene-substituted spirocyclic compound, such that the chain-extending component consists of the alkylene-substituted spirocyclic compound. The isocyanate component and the chain extender component of a TPU composition are often referred to as the "hard segment" of the TPU. In one embodiment of the present invention, the TPU composition contains more than 50% by weight, or even at least 55% by weight, or even at least 60% by weight, of the hard segment. TPU compositions prepared according to the present invention may have a Shore D hardness of 40D to 85D, for example, 50D to 80D.In one embodiment, TPU comprises the reaction product of 25% to 30% by weight of a polyisocyanate component comprising, essentially consisting of, or consisting of hexamethylene-1,6-diisocyanate, 20% to 40% by weight of polyether polyol, and 30% to 45% by weight of a chain extender component comprising, essentially consisting of, or consisting of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination of these compounds. In one embodiment, the present invention provides a thermoplastic polyurethane composition comprising the reaction product of (1) a polyisocyanate component, wherein the polyisocyanate component comprises hexamethylene-1,6-diisocyanate and contains less than 5 mol% of isocyanates other than hexamethylene-1,6-diisocyanate, (2) a polyol component, wherein the polyol component comprises a polyether polyol, a polycaprolactone polyol, or a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol, and (3) a chain extender component, wherein the chain extender component comprises at least 90 mol% of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, a saturated spirocyclic diamine substituted with alkylene, or a combination of these compounds,wherein the alkylene-substituted spirocyclic compound comprises two rings containing 5 to 7 atoms per ring, and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxyl group or an amine, wherein the amine is a primary or secondary amine. In one embodiment, the polyol component may be a polyether polyol. In another embodiment, the polyol component may comprise a polyester polyol as defined in the claims. In yet another embodiment, the polyol may be selected from poly(tetramethylene ether) glycol, polycaprolactone polyol, or polyethylene butylene adipate, or combinations thereof, as defined in the claims. In one embodiment, the present invention provides a thermoplastic polyurethane composition comprising the reaction product of (1) a polyisocyanate component, wherein the polyisocyanate component consists of hexamethylene-1,6-diisocyanate, (2) a polyol component, wherein the polyol component comprises a polyether polyol, a polycaprolactone polyol, or a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol, and (3) a chain extender component, wherein the chain extender component consists of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof,wherein the alkylene-substituted spirocyclic compound comprises two rings containing 5 to 7 atoms per ring and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxyl group or an amine, wherein the amine is a primary or secondary amine, and wherein the chain-extending component comprises less than 10 mol% of a chain co-extender other than the alkylene-substituted spirocyclic compound. In this embodiment, the polyol component may comprise, consist essentially of, or consist of poly(tetramethylene ether) glycol, polycaprolactone polyol, or polyethylene butylene adipate, or combinations thereof, as defined in the claims. In one embodiment, the TPU composition of the present invention exhibits resistance to staining with permanent markers according to ASTM D6578M-13, showing an E value of less than 35 or even less than 31, or even 17 or less. In one embodiment, the TPU composition is transparent, i.e., it has a turbidity, measured according to ASTM D1003-11, of less than 20 or 15 or less. In one embodiment, the TPU composition of the present invention also exhibits average chemical resistance, according to EN 438-2, of at least 4, 5, or even 5 (visual rating). In another aspect, the present invention further describes a manufacturing process for the TPU composition described herein, comprising reacting (1) a polyisocyanate component comprising hexamethylene-1,6-diisocyanate, (2) a polyol component, and (3) a chain extender component comprising an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof, wherein the alkylene-substituted spirocyclic compound contains two rings containing 5 to 7 atoms per ring, and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxy group or an amine, wherein the amine is a primary or secondary amine; resulting in a TPU composition that is resistant to chemical degradation and staining.It should be understood that the components of the TPU composition include all the elements described in the various embodiments set out in this document. The TPU polymer production process of this invention can utilize conventional and hereafter developed TPU manufacturing equipment and processes, whether known or hereafter developed. The three reactants (the isocyanate component, the polyether polyol, and the chain extender component) are reacted together to form the TPU useful in this invention. In one embodiment, the process is a so-called "simple" process, where the three reactants are added to an extruder reactor and reacted. The weight equivalent of the diisocyanate relative to the total weight equivalent of the hydroxyl-containing components—that is, the polyether polyol intermediate and the chain extender—can range from approximately 0.95 to approximately 1.10, or from approximately 0.96 to approximately 1.03, and even from approximately 0.97 to approximately 1.05. In some embodiments, an optional urethane catalyst can be used in the reaction. The TPU of the present invention can also be prepared using a prepolymerization process. In the prepolymer route, the polyol intermediates are reacted with generally an equivalent excess of one or more diisocyanates to form a prepolymer solution containing free or unreacted diisocyanate. In some embodiments, an optional urethane catalyst can be used in the reaction. Subsequently, a chain extender, as described above, is added in an amount generally equivalent to the isocyanate terminal groups, as well as any free or unreacted diisocyanate compounds.The overall equivalent ratio between the total diisocyanate and the total equivalent of the polyol intermediate and the chain extender is thus approximately 0.95 to approximately 1.10, or approximately 0.96 to approximately 1.03, and even approximately 0.97 to approximately 1.05. The reaction temperature of the chain extender is generally approximately 100 °C to approximately 250 °C or approximately 200 °C to approximately 250 °C. Typically, the prepolymer route can be carried out in any conventional device that includes an extruder. In such embodiments, the polyol intermediates are reacted with an excess equivalent of a diisocyanate in a first section of the extruder to form a prepolymer solution, and subsequently, the chain extender is added in a downstream section and reacted with the prepolymer solution.Any conventional extruder can be used, including extruders equipped with barrier screws having a length-to-diameter ratio of at least 20 and, in some embodiments, at least 25. In one embodiment, the polyisocyanate component comprising hexamethylene-1,6-diisocyanate, the polyol component, and the chain extender component comprising an alkylene-substituted spirocyclic compound are mixed in a single- or twin-screw extruder with multiple heating zones and multiple feed holes between its feed end and nozzle end. The ingredients can be added at one or more of the feed holes, and the resulting TPU composition exiting the nozzle end of the extruder can be granulated. In another embodiment, the polyisocyanate component comprising hexamethylene-1,6-diisocyanate, the polyol component, and the chain extender component comprising an alkylene-substituted spirocyclic compound as described herein are generally added together and reacted according to the standard polyurethane synthesis methodology as described herein. The TPU-forming components of the present invention can be polymerized in the molten state in a suitable mixer, such as an internal mixer known as a Banbur mixer, or in an extruder. Suitable processing or polymerization temperatures are from approximately 100°C to approximately 250°C in one aspect, and from approximately 200°C to approximately 250°C in another aspect. Optionally, it may be desirable to use catalysts such as tin and other metal carboxylates, as well as tertiary amines. Examples of suitable catalysts, which in particular accelerate the reaction between the NCO groups of diisocyanates and the hydroxy groups of polyols and chain extenders, are the conventional tertiary amines already known in this field, for example, triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethylpiperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo[2,2,2]octane and similar compounds, and also in particular organometallic compounds, such as titanium esters, iron compounds, for example, ferric acetylacetonate, tin compounds, for example, tin diacetate, tin dioctoate or tin dilaurate, or the dialkyltin salts of aliphatic carboxylic acids, for example, dibutyltin diacetate, dibutyltin dilaurate or similar compounds, phenylmercuric propionate,lead octoate, iron acetylacetonate, magnesium acetylacetonate, or bismuth compounds such as bismuth octoate, bismuth laurate and the like. The TPU polymers of the present invention can be blended with various conventional additives or blending agents, known in this field and described hereinafter, such as antioxidants, biocides, fungicides, antimicrobial agents, antistatic additives, plasticizers, fillers, extenders, flame retardants, impact modifiers, pigments, lubricants, release agents, rheology modifiers, UV absorbers, and the like. The level of conventional additives will depend on the final properties and the cost of the desired end-use application, as is well known to those skilled in the field of TPU compositions. These additional additives can be incorporated into the components of, or into the reaction mixture for preparing, the TPU, or after manufacturing the TPU.In another process, all materials can be mixed with the TPU and then melted, or they can be incorporated directly into the melt of the TPU composition. In another aspect, the present invention relates to an article comprising the TPU of the present invention as described in detail herein. The articles comprising the TPU of the present invention may be any molded articles, such as injection-molded articles. In one embodiment, such TPU may be used to manufacture articles where a transparent finish is desirable. In other embodiments, the articles containing the various compositions described above include any article that may be exposed to chemicals or staining agents, such as inks, during use, and especially articles that have not been manufactured using thermoplastic polyurethanes in the past due to the fact that such materials have insufficient resistance to chemicals or staining.Articles and applications in which this composition may be useful include, but are not limited to, protective films, decorative films, graphic films, labels, floor coverings, multilayer film constructions, consumer products, electronic products, fiber composites, or protective or decorative coating alternatives (e.g., varnish).The specific applications to which the benefits of the TPU composition of the present invention can be applied are varied and numerous and include, by way of example only, paint protection films, glass protection films for interior and exterior use, protective films for suitcases, lens protection, graffiti protection on signs or other surfaces, anti-wear coatings on floors, automotive parts, including interior and exterior surfaces, protective covers for electronic devices, screen protection, as well as fiber composites for automotive, aerospace, wind energy, and pressure vessel applications. In fact, the TPU composition of the present invention can be useful in any application where a person skilled in this field would find a transparent thermoplastic material that is resistant to staining, whether currently known or discovered in the future. The compositions of the invention, or any mixture thereof, may be used to prepare the molded products of this invention in any molding process. Molding processes are well known to those skilled in this field and include, but are not limited to, casting, cold forming with mold and counter-mold, compression molding, mold sponging, injection molding, gas-assisted injection molding, profile coextrusion, profile extrusion, rotational molding, sheet extrusion, slip molding, spray techniques, thermoforming, transfer molding, vacuum forming, wet contact or roll forming, blow molding, blow molding and extrusion, blow molding and injection, and blow molding, stretch and injection, or combinations of these processes. In another aspect, the present invention relates to a method for increasing the chemical and staining resistance of an article by manufacturing an article comprising an effective amount of a thermoplastic polyurethane (TPU), wherein the TPU comprises the reaction product of (1) an aliphatic polyisocyanate comprising, or essentially consisting of, hexamethylene-1,6-diisocyanate, (2) a polyol component as described herein, and (3) a chain extender component comprising, essentially consisting of, or consisting of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof, wherein the alkylene-substituted spirocyclic compound contains two rings containing 5 to 7 atoms per ring,and where each ring is substituted with an alkylene group containing from 1 to 4 carbon atoms, terminated in a hydroxyl group or an amine, where the amine is a primary or secondary amine. The present technology also includes the use of a thermoplastic polyurethane composition wherein the TPU comprises the reaction product of (1) a polyisocyanate component comprising, or essentially consisting of, or consisting of hexamethylene-1,6-diisocyanate, (2) a polyol component as described herein, and (3) a chain extender component comprising, or essentially consisting of, or consisting of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof, wherein the alkylene-substituted spirocyclic compound contains two rings containing 5 to 7 atoms per ring, and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxy group or an amine.where the amine is a primary or secondary amine used to increase an item's resistance to chemicals and stains. Its use can also make the item transparent. Various features and preferred embodiments will be described below by way of non-limiting illustration. The quantity of each chemical component described is presented excluding any solvent or diluent oil that may be ordinarily present in the commercial material; that is, it is based on active chemical compounds, unless otherwise stated. However, unless otherwise stated, each chemical component or composition referred to herein should be understood to be a commercial grade material, which may contain the isomers, by-products, derivatives, and other materials such as are normally understood to be present in the commercial grade. Reference to any document is not an admission that such document constitutes something already known or accepted in this field or that it forms part of the common knowledge of experts in this field in any jurisdiction. It is understood that the upper and lower limits of quantity, range, and ratio set forth herein may be combined independently. Similarly, the ranges and quantities corresponding to each element of the invention may be used in conjunction with ranges or quantities corresponding to any of the other elements. Examples In these examples, TPUs are synthesized from the components listed in Table 1. In Table 1, SPG refers to an alkylene-substituted spirocyclic compound comprising: PTMEG is a polytetramethylene glycol polyether polyol, PEBA is a polyethylene butylene adipate, CAPA is a polycaprolactone polyol, BDO is 1, 4-butanodiol, HDO is 1, 6-hexanodiol, DPG is dipropylene glycol, BEPD is 2-butyl-2-1, 3-propylene NPG is neopentyl glycol, HDI is hexamethylene-1, 6-diisocyanate, MDI is 4, 4'-methylenbis (phenyl isocyanate) and H12MDI is dicyclohexylmethane-4, 4'-diisocyanate. Table 1 The TPUs in Table 1 were evaluated for turbidity according to ASTM D1003-11 (measured with a BYK Haze-gard Plus), permanent marker staining according to ASTM D6578M-13, and chemical resistance according to EN 438-2. For the permanent marker test, ASTM D6578M-13 was followed, except that the E (color change of the material measured using a Hunterlab Colorflex A60-1010-615 colorimeter) was measured after 5 days instead of the 24 hours specified in the test method, and a red solvent-based permanent marker was used instead of a blue solvent-based permanent marker as specified in the test. Chemical resistance results are reported using a visual grading scale from 0 (surface destroyed) to 5 (no damage) according to the standard specified by the test method.The test results are summarized in Table 2. Table 2 As shown above, TPU compositions prepared according to the present invention provide transparency with a combination of stain resistance, as represented by turbidity measurement, permanent marker testing, and chemical degradation resistance testing. All molecular weight values ​​provided herein are weighted average molecular weights, unless otherwise stated. All molecular weight values ​​have been determined by GPC (gel permeation chromatography) analysis, unless otherwise stated. As used herein, the transitional expression "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional unspecified elements or method steps. However, in each instance of "comprising" herein, the expression is also intended to encompass, as alternative embodiments, the expressions "consisting essentially of" and "consisting of," where "consisting of" excludes any unspecified element or step, and "consisting essentially of" permits the inclusion of additional unspecified elements or steps that do not substantially affect the essential or basic and novel characteristics of the composition or method under consideration. Although certain representative embodiments and representative details have been shown for the purpose of illustrating the present invention, it will be evident to those skilled in the field that various changes and modifications can be made to it without leaving the scope of the invention, which need only be limited by the following claims.

Claims

1. A thermoplastic polyurethane composition comprising the reaction product of (1) a polyisocyanate component, wherein the polyisocyanate component comprises hexamethylene-1,6-diisocyanate and contains less than 5 mol% of isocyanates other than hexamethylene-1,6-diisocyanate, (2) a polyol component, wherein the polyol component comprises a polyether polyol, a polycaprolactone polyol, or a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol; a (3) chain-extending component, wherein the chain-extending component comprises at least 90 mol% of an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination of these compounds,and wherein the alkylene-substituted spirocyclic compound comprises two rings containing 5 to 7 atoms per ring, and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxyl group or an amine, wherein the amine is a primary or secondary amine.

2. The thermoplastic polyurethane composition of claim 1, wherein the alkylene-substituted spirocyclic compound is a spiroheterocycle containing 2 heteroatoms in each ring, wherein the heteroatoms are oxygen, nitrogen, sulfur, or phosphorus.

3. The thermoplastic polyurethane composition of claim 1, wherein the structural formula of the alkylene-substituted spirocyclic compound is: wherein each X is independently selected from O, CHR2, NR2, S, PR2, wherein each R2 represents a hydrogen atom or an alkyl group containing 1 to 6 carbon atoms,each R1 is an alkylene containing from 1 to 4 carbon atoms and each Z is selected from -OH or -NHR3, wherein R3 represents a hydrogen atom or an alkyl group containing from 1 to 6 carbon atoms, wherein a, b, c, d, e, f, gyh are each independently an integer from 0 to 2, provided that the sum of a, b, c, d is from 1 to 3 and the sum of e, f, gyh is from 1 to 3.

4. The thermoplastic polyurethane composition of claim 3, (a) wherein a equals ag, b equals ah, c equals ae, and d equals af; or (b) wherein the spirocyclic dialkylene compound contains two 6-membered rings, X is O, R1 is 1,1-dimethylethyl, Z is -OH and wherein either (i) a is 0, b is 1, c is 1, d is 0, e is 1, f is 0, g is 0 and h is 1, or (ii) a is 1, b is 0, c is 0, d is 1, e is 0, f is 1, g is 1 and h is 0.

5. The thermoplastic polyurethane composition of claim 1,wherein the structural formula of the spirocyclic dialkylene compound is: wherein each X is selected from O, CHR2, NR2, S, PR2, wherein each R2 represents a hydrogen atom or an alkyl group containing 1 to 6 carbon atoms, each R1 is an alkylene containing 1 to 4 carbon atoms, and each Z is selected from -OH or -NHR3, wherein R3 represents a hydrogen atom or an alkyl group containing 1 to 6 carbon atoms, and preferably wherein X is O, R1 is 1,1-dimethylethyl, and Z is -OH.

6. The thermoplastic polyurethane composition of any of claims 1 to 5, wherein the polyether polyol comprises poly(tetramethylene ether) glycol, or wherein the polyether polyol consists of poly(tetramethylene ether) glycol.

7. The thermoplastic polyurethane composition of any of claims 1 to 5,wherein the polyol component consists of polycaprolactone polyol.

8. The thermoplastic polyurethane composition of any one of claims 1 to 7, wherein the thermoplastic polyurethane composition comprises at least 60% by weight of a hard segment.

9. An article comprising a thermoplastic polyurethane composition according to any one of claims 1 to 8.

10. The article of claim 9, wherein the article is a molded article.

11. The article of claim 9, wherein the article is a protective film.

12. A method for increasing the chemical and stain resistance of an article, comprising molding an article using the thermoplastic polyurethane composition of any one of claims 1 to 8.

13. A thermoplastic polyurethane composition comprising: (1) a polyisocyanate component consisting of hexamethylene-1,6-diisocyanate; (2) a polyol component,wherein the polyol component comprises a polyether polyol, a polycaprolactone polyol, or a copolymer of a polyether polyol and a polyol selected from polyester polyol, polycarbonate polyol, polycaprolactone polyol, or polyamide polyol; and (3) a chain-extending component comprising an alkylene-substituted spirocyclic compound comprising an alkylene-substituted saturated spirocyclic diol, an alkylene-substituted saturated spirocyclic diamine, or a combination thereof, wherein the alkylene-substituted spirocyclic compound contains two rings containing 5 to 7 atoms per ring, and wherein each ring is substituted with an alkylene group containing 1 to 4 carbon atoms, terminated in a hydroxy group or an amine, wherein the amine is a primary or secondary amine.

14. The thermoplastic polyurethane composition of claim 13,wherein the polyether polyol comprises poly(tetramethylene ether) glycol.