Spraying polyurethane elastomer and production method thereof

Abstract

The present disclosure relates to sprayed polyether and polyester polyurethane elastomeric articles and related methods of producing such elastomeric articles. More specifically, the present invention provides sprayed polyester polyurethane elastomer articles exhibiting excellent tensile and tear strength, excellent elongation properties, and improved wear resistance, with an adjustable tensile modulus.

Description

[0001] This application is a divisional application of Patent Application No. 202080068752.5 entitled "Sprayed Polyurethane Elastomer and Production Method Thereof". The original application corresponds to international application PCT / US2020 / 053385, with a filing date of September 30, 2020, and a priority date of September 30, 2019. Technical Field

[0002] This application generally relates to sprayed polyurethane elastomers, methods for producing articles using such sprayed polyurethane elastomers, and the resulting articles. Background Technology

[0003] Spray-applied polyurethane elastomers are used in numerous applications, including high-end products in the automotive and other related fields, for purposes such as interior materials, dashboard upholstery, and seat upholstery. Typically, spray-applied polyurethane elastomers are based on two-component polyurethane systems formulated with polyol resins and isocyanate or isocyanate prepolymers. Traditional spray-applied elastomers can be categorized into three main types: spray-applied polyurethane, spray-applied polyurea, and hybrid systems derived from polyurethane / polyurea using polyether polyols, polyamines, or combinations thereof. The resin composition typically contains low-viscosity polyols and additives such as catalysts, surfactants, chain extenders, crosslinking agents, and fillers. Most polyurethane elastomers typically contain one or more polyols with high OH functionality, which can generate crosslinks to achieve better mechanical properties. When combined with sophisticated finishing tools and techniques, spray-applied technology enables unique processes for designing products with attractive effects, including blending colors, logos, and textures. Furthermore, spray-applied technology offers a captivating, luxurious look and feel superior to other materials. With the increasing demand for high tensile and tear strength, as well as excellent elongation and scratch resistance, the development of improved sprayable polyurethane elastomers with these properties is continuously needed for various applications. For example, these elastomers can be used as abrasion or scratch-resistant layers on certain articles or as protective coatings for shoe components, i.e., outsoles or midsoles, unit soles, or uppers. Due to their excellent physical properties, particularly tear and tensile strength, polyester polyurethane elastomers have been used in a variety of applications, including industrial and consumer products. However, due to their viscosity, reactivity profile, and processability characteristics, polyester-based polyurethane elastomers are primarily manufactured by casting. Polyester polyurethane systems have not been extensively studied and processed via spraying technology (which can further enable air injection to reduce the density to 0.60-0.90 g / cm³ as needed). 3 The scope of sprayed polyester elastomers can also open the door to many new applications where sprayed polyether polyurethanes and sprayed polyureas have shown limitations, for example, where products with excellent elongation properties and high resistance to organic solvents, chemicals, greases, oils and fuels are required.

[0004] There is a growing desire to replace coated fabrics (such as synthetic leather) with improved materials. Coated fabrics are textiles / loose cloths with a thin coating on one surface. These textiles are used to provide performance properties, including tensile strength, tensile modulus, and tear resistance. The textiles are typically flexible and usually retain their flexibility after coating. The coating acts as a protective layer for the textile, providing a degree of abrasion resistance while also providing aesthetic features such as color and texture. The coating contributes little to tensile strength, tensile modulus, and tear resistance. Coated fabrics are known to have high tensile modulus and therefore resistance to creep and permanent deformation during use. Creep resistance is required in many applications, such as footwear. On the other hand, polyurethane is prone to creep and permanent deformation. Therefore, a novel polyurethane method is needed to obtain a suitable alternative to coated fabrics.

[0005] Regarding tensile modulus, some applications may require a low tensile modulus, while others require a high tensile modulus. In either case, excellent strength and elongation are necessary. There is a need to develop sprayed polyester elastomers with adjustable tensile modulus, particularly at around 0.95 g / cm³. 3 At lower densities.

[0006] In summary, there is a need for improved spray-coated polyester elastomers with suitable density (preferably lower density), good resistance to permanent deformation, and adjustable modulus. Summary of the Invention

[0007] This document discloses novel compositions relating to sprayed polyurethane elastomer articles and related methods for producing such elastomer articles. More specifically, this document provides sprayed polyester polyurethane elastomer articles exhibiting excellent tensile and tear strength, excellent elongation properties, and improved abrasion resistance with an adjustable modulus. Compared to sprayed polyether polyurethane and sprayed polyurea, the sprayed polyester polyurethane produced according to this disclosure offers advantages including superior mechanical properties and unique performance characteristics for new applications in which sprayed polyether polyurethane and sprayed polyurea have shown limitations, such as better elongation and scratch resistance, high resistance to organic solvents, chemicals, greases, oils, and fuels; and high resistance to creep and permanent deformation during use. Furthermore, the sprayed polyester polyurethane elastomer produced according to the invention exhibits better adhesion to a variety of different surfaces (fabrics, plastics, wood, glass, and metals) than sprayed polyether.

[0008] In some embodiments, the spraying technique described herein includes injecting air into the composition to reduce the overall density of the composition. In some embodiments, the density may be reduced to, for example, a range of 0.60-1.20 g / cm³. Using the described methods and processes, the resulting articles exhibit excellent elongation properties, high resistance to harsh environments, and excellent elasticity against chemicals, friction, etc.

[0009] This document discloses novel compositions comprising sprayable polyurethane elastomers, including: (a) an isocyanate-functionalized urethane prepolymer derived from monomer diphenylmethane diisocyanate (MMDI) and a polyester polyol; and (b) an isocyanate reactive component comprising about 10-60 to about 90-95 parts by weight of a polyol, wherein the polyol is a polyester polyol having about 30 to about 200 mg KOH / g.

[0010] A method for forming a sprayable polyurethane elastomer is also disclosed, the method comprising reacting MMDI with a polyester diol to form an isocyanate-functionalized urethane prepolymer, blending at least one polyol to form an isocyanate reactive component, and mixing the isocyanate prepolymer and the isocyanate reactive component at an isocyanate index of about 85 to about 130 to form a polyurethane elastomer. In one embodiment, the polyol is present in an amount of about 10 to about 90 parts by weight of the isocyanate reactive component, and the polyol comprises a polyester polyol having a hydroxyl number of about 30 to about 200 mg KOH / g.

[0011] Other features and advantages of the invention will be readily apparent, as they will be better understood upon reading the following description taken in conjunction with the accompanying drawings.

[0012] This document discloses novel chemical substances that provide a unique method for obtaining articles with high tensile modulus. Alternative approaches to obtaining such articles with high tensile modulus are also disclosed. For example, conventionally accepted methods for coating materials involve spraying chemicals directly onto loose fabrics or textiles, which requires complex and difficult-to-understand techniques. As taught herein, the inventors have devised a unique method that utilizes the application of a sprayed polyurethane system, comprising one, two, or more spray applications: in one embodiment, for example, two sprayed polyurethane systems are used to form a multilayer article: one system containing high tensile modulus is sprayed in a relatively thin layer to maintain low flexural modulus (acting similarly to loose fabric); the other system contains a relatively thick spray layer with low tensile modulus to deliver the remaining overall properties (tensile, tear strength, elongation, loss / wear, etc.). The complexity of the system is reduced by the ability to automate the process. In some embodiments, articles with multilayer structures and layers can be constructed via a multi-step process in a three-dimensional, layer-by-layer approach comprising one or more polyurethane systems. Attached Figure Description

[0013] Figure 1 A graph showing a complete dataset view is provided, comparing the performance of cast samples (without aeration) with that of sprayed samples, which have reduced density due to aeration.

[0014] Figure 2 A graph showing a magnified view of the low-strain region of samples A, B, and C (all examples of ester chemicals described herein) is provided. Detailed Implementation

[0015] The invention can be more readily understood by referring to the following detailed description of specific embodiments included herein. Although the invention has been described with reference to specific details of certain embodiments thereof, these details should not be construed as limiting the scope of the invention. The entire text of all references mentioned herein is hereby incorporated by reference.

[0016] This document discloses novel compositions relating to sprayed polyether and polyester polyurethane elastomer articles and related methods for producing such elastomer articles. More specifically, this document provides sprayed polyester polyurethane elastomer articles exhibiting excellent tensile and tear strength, excellent elongation properties, and improved abrasion resistance, and having a tensile modulus that can be adjusted as needed. Compared to sprayed polyether polyurethane and sprayed polyurea, the sprayed polyester polyurethane produced according to the present invention provides unique properties including superior mechanical properties and new applications in which sprayed polyether polyurethane and sprayed polyurea have shown limitations. For example, articles made by the methods described herein include improved elongation properties; high resistance to organic solvents, chemicals, greases, oils, and fuels; improved creep resistance; and excellent scratch resistance. Furthermore, the sprayed polyester polyurethane elastomer produced according to the present invention exhibits better adhesion to a variety of different surfaces (fabrics, plastics, wood, glass, and metals) than conventional sprayed polyethers.

[0017] The unique properties of the sprayed polyester elastomer produced according to the present invention make the elastomer suitable for a wide variety of uses and applications, including but not limited to use as a protective coating, abrasion-resistant layer, anti-slip layer, shoe component such as an outsole, or a protective coating for the midsole and upper, or a protective layer for clothing. In addition to the applications mentioned above where sprayed polyurethane elastomers can be utilized, the polyurethane elastomer materials described herein can find many other applications, such as where a softer, thinner layer with excellent elongation properties is required.

[0018] In one embodiment, the sprayable polyurethane elastomer article of the present invention is prepared by reacting a resin blend with a polyisocyanate prepolymer (isocyanate prepolymer). The resin blend contains polyols and additives selectively formulated according to processing requirements and spraying machine capabilities. The viscosity of the sprayable polyether polyurethane resin is typically 1100-1200 cps at 25°C and 400-450 cps at 45°C, while the viscosity of the polyether-based ISO prepolymer is 1000-1100 cps at 25°C and 150-200 cps at 45°C. The viscosity of the sprayable polyester polyurethane resin according to the present invention is about 2500-6800 cps at 25°C, depending on the type of polyester used. All viscosities in the table below refer to viscosities measured at different temperatures according to the method of ASTM standard D2196.

[0019] Reactivity profiles and curing profiles are important considerations in designing the desired sprayed polyurethane system and can be specifically engineered using appropriate catalyst packages. In some embodiments, the catalyst package used in this disclosure includes a metal catalyst. In some embodiments, the catalyst package used in this disclosure does not include a metal catalyst.

[0020] The reaction mixture comprising the sprayed polyurethane elastomer composition described herein can be used in a variety of different ways: for example, the mixture can be sprayed onto a mold or substrate to produce a thin coating by a single spray, or onto an article by multiple sprays to produce a thicker coating. Such multiple sprays can be engineered as a continuous process or a discontinuous process with preferred intervals or cycle times. In some embodiments, with a discontinuous process, each layer can be designed to have a different tensile modulus, stiffness, hardness, thickness, or tensile modulus, which provides sufficient functionality to design properties and configurations as needed. The reaction mixture can also be sprayed onto fabrics, glass fiber mats, or carbon fiber mats to produce reinforced composites for, for example, clothing, footwear, and automotive purposes. The resulting articles can be designed as soft-touch or rigid elastomers. Multiple spray passes can contain multiple systems (or multiple reaction mixtures).

[0021] Most molds used for polyurethane spraying are made of metals with high thermal conductivity (e.g., steel, aluminum). During the spraying operation, the molds must be kept at high temperatures, typically around 120°F to 150°F, to aid the polyurethane reaction and achieve the necessary mechanical properties. The high thermal conductivity of these molds is essential for transferring the necessary heat to support the reaction. However, the surprising and unexpected discovery of this invention is the ability to spray onto molds made of low thermal conductivity while still obtaining the desired mechanical properties. Metal molds, commonly used in the prior art, are costly to produce. Using mold surfaces with low electrical conductivity, such as plastics, is desirable because it reduces mold costs. However, in the past, using mold surfaces with low electrical conductivity has resulted in articles with lower mechanical properties. However, the reaction mixture of this invention is suitable for molds with low electrical conductivity without compromising the mechanical properties of the resulting article.

[0022] In some embodiments, the sprayed elastomer according to the invention can be sprayed layer by layer to produce 3D objects, similar to layer-by-layer 3D printing, 3D casting, or 3D dispensing techniques, but on a much larger scale and at a much faster speed. In some embodiments, the production rate of the spraying machine, as contemplated herein, can be in the range of about 5-100 g / s, more typically about 6-30 g / s, and most typically about 8-20 g / s. The thickness of each sprayed layer can be in the range of about 0.2-3.0 mm, more typically about 0.4-2.0 mm, and most typically about 0.5-1.5 mm. The production rate of the spraying machine and the thickness of the sprayed layers can be adjusted and customized according to the practical characteristics of the resulting article, as will be apparent to those skilled in the art.

[0023] Advances in spraying technology are characterized by air injection capabilities, enabling the manufacture of low-density sprayed elastomer parts. In some embodiments, instruments manufactured by Hennecke, Inc. (Bridgeville, Pennsylvania, US) can be used to inject air and produce lightweight sprayed elastomers. The injected air creates voids in the elastomer's mass structure, which can result in a density reduction of approximately 5%-40%. In some embodiments, the sprayed polyurethane elastomer according to the invention can achieve a density of approximately 0.10-5.00 g / cm³. 3 0.60-1.10 g / cm 3 More typically, approximately 0.65–1.10 g / cm³ 3 Most typically, it is about 0.70-0.98 g / cm³. 3 The coating is applied within a specified density range. The density of the sprayed polyurethane elastomer can be adjusted and customized according to the practical characteristics of the resulting product, which is obvious to those skilled in the art.

[0024] Compared to full-density sprayed polyether elastomers, the lightweight sprayed polyester elastomers according to this disclosure (e.g., 10-30% lighter) exhibit the same or better physical properties and can provide a competitive advantage in terms of weight reduction for many new applications. In some embodiments, the lightweight sprayed elastomers of the present invention can be up to 10%, 20%, 30%, or 40% lighter than similar standard products. In one embodiment, the weight reduction of the sprayed elastomer can be achieved by physically expanding the polyurethane system with air. Another advantage of the lightweight sprayed polyester elastomers described herein is the reduction in overall cost.

[0025] In some embodiments, compared to polyether-based sprayed elastomers with similar physical properties, density, and hardness, the sprayed polyester elastomers according to the present disclosure are formulated to exhibit superior mechanical properties and show significantly improved tensile, tear, and elongation. While prior art polyurethane elastomers may sacrifice properties when density is reduced to a certain extent, the sprayed polyester elastomers according to this disclosure largely maintain excellent mechanical properties. Compared to full-density sprayed polyether elastomers, the sprayed polyester elastomers according to this disclosure exhibit the same or better physical properties. Furthermore, the sprayed polyester elastomers exhibit excellent properties independent of the thermal conductivity of the mold.

[0026] Catalyst packages comprising one or more catalysts can be specially formulated to provide better flowability for the spraying system described herein in the spraying process and achieve surface dryness (surface curing) within 20–90 s, more typically 30–60 s, and most typically 40–50 s to match the target processing cycle time. Sprayed polyurethane can be cured in a heated mold at approximately 30°C–120°C, more typically 40°C–100°C, and most typically 60°C–80°C. Another advantage of the method discussed herein, compared to methods involving cast elastomers where post-curing at >80°C may require at least 8–24 hours, is that post-curing is not required.

[0027] The sprayed polyester polyurethane elastomer produced according to this disclosure offers improved mechanical properties and unique characteristics for new applications where previously available sprayed polyether polyurethane and sprayed polyurea have shown limitations. Furthermore, the sprayed polyester polyurethane elastomer exhibits better adhesion to a wide variety of surfaces compared to sprayed polyether. Moreover, the sprayed polyurethane elastomer produced according to this disclosure can be produced at a lower density of about <0.95 g / cm, optionally in the range of about 0.4-0.95 g / cm or 0.60-0.95 g / cm, and exhibits better physical properties than current sprayed polyether elastomer products with higher densities.

[0028] The sprayable elastic polyurethane disclosed herein comprises a reaction product of an isocyanate component and an isocyanate reactive component. In some embodiments, the isocyanate component comprises a polyisocyanate. The organic polyisocyanates used in this disclosure may include aliphatic, alicyclic, and aromatic bifunctional or polyfunctional isocyanates and any desired mixtures thereof. Examples include, but are not limited to, monomeric methane diphenyl diisocyanate (MMDI), such as 4,4"-methane diphenyl diisocyanate, 2,4"-methane diphenyl diisocyanate, mixtures of monomeric methane diphenyl diisocyanate and higher nucleoisocyanates (polymeric MDI), naphthalene diisocyanate (NDI), especially 1,5-naphthalene diisocyanate, 3,3'-dimethyl-4,4'-diisocyanate biphenyl (TODI), terephthalic diisocyanate (PPDI), tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 2,4- or 2,6-toluene diisocyanate (TDI), or mixtures thereof.

[0029] In some embodiments, this disclosure may use NDI, a mixture of NDI and MDI, or more preferably 4,4'-MDI. The more preferred 4,4'-MDI may comprise 0 to 20 wt% 2,4'-MDI and a small amount, at most about 10 wt% urethane-modified or urea-ketimine-modified polyisocyanate. Small amounts of polyphenylene polymethylene polyisocyanate (polymer MDI) may also be used. The total amount of these high-functionality polyisocyanates should not exceed 5 wt% by weight of the total isocyanates used.

[0030] In the first step, the polyisocyanate component is at least partially mixed with a polyol and optionally a crosslinking agent and / or a chain extender, and then the mixture is reacted at 110 to 180°C, preferably 130 to 170°C, and more preferably 140 to 155°C, to obtain a prepolymer with isocyanate groups. The resulting isocyanate-terminated prepolymer according to the invention preferably has an NCO content of 2 wt% to 20 wt%, more preferably 2 wt% to 10 wt%, and especially 4 wt% to 8 wt%.

[0031] Preferably, the isocyanate-terminated prepolymer is prepared using at least 50 wt%, more preferably at least 80 wt%, even more preferably at least 90 wt%, and especially 100 wt% of a polyol. The isocyanate-terminated prepolymer is further prepared using at least 50 wt%, more preferably at least 80 wt%, even more preferably at least 90 wt%, and especially 100 wt% of isocyanate. The remaining isocyanate and remaining polyol can then be used as is and / or in the form of conventional prepolymers to produce the sprayable polyurethane elastomers of this disclosure. Conventional prepolymers are obtained by reacting the aforementioned polyisocyanate, for example, at a temperature of 30°C to 100°C, and preferably at about 80°C, with a polyol and optionally a crosslinking agent and / or a chain extender.

[0032] The isocyanate reactive component of this disclosure may include one or more of polyether polyols, polyester polyols, and combinations thereof. In some embodiments, this disclosure uses polyester polyols. Polyester polyols may be obtained, for example, from organic dicarboxylic acids having 2 to 12 carbon atoms, preferably aliphatic dicarboxylic acids having 4 to 6 carbon atoms, and polyols having 2 to 12 carbon atoms, preferably 2 to 6 carbon atoms, preferably diols. Useful dicarboxylic acids include, for example, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, and terephthalic acid. Dicarboxylic acids may be used not only alone but also in mixtures with each other. Corresponding dicarboxylic acid derivatives, such as dicarboxylic acid esters or dicarboxylic acid anhydrides of alcohols having 1 to 4 carbon atoms, may also be used instead of free dicarboxylic acids. Preferred ingredients include mixtures of dicarboxylic acids, particularly adipic acid, comprising, for example, 20 to 35:35 to 50:20 to 32 parts by weight of succinic acid, glutaric acid, and adipic acid. Examples of diols and polyols, especially diols, include: ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, 2-methyl-1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, glycerol, and trimethylolpropane. Preferred ingredients include ethylene glycol, diethylene glycol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Diols can be used not only alone but also in mixtures. A mixture of ethylene glycol and 1,4-butanediol is preferred. Polyester polyols formed from lactones, such as ε-caprolactone, or hydroxycarboxylic acids, such as 2-hydroxyhexanoic acid, may also be used.

[0033] To prepare polyester polyols, organic, such as aromatic and preferably aliphatic polycarboxylic acids and / or derivatives and polyols can, advantageously in the absence of a catalyst or preferably in the presence of an esterification catalyst, in an inert gas atmosphere, such as nitrogen, carbon monoxide, helium or argon, at a temperature of 150°C to 250°C, preferably 180°C to 220°C, optionally under reduced pressure, polycondense to a desired acid value, preferably less than 10, and more preferably less than 2. In a preferred embodiment, the esterification mixture is polycondensed at the above temperature and atmospheric pressure, and then at a pressure of less than 500 mbar, preferably 50 to 150 mbar, to an acid value of 80-30, preferably 40-30. Useful esterification catalysts include, for example, catalysts in the form of metals, metal oxides or metal salts, such as iron, cadmium, cobalt, lead, zinc, antimony, magnesium, titanium and tin. However, polycondensation can also be carried out in the liquid phase in the presence of a diluent and / or entrainer such as benzene, toluene, xylene or chlorobenzene, to azeotropically distill off the condensed water. To prepare polyester polyols, organic polycarboxylic acids and / or derivatives are advantageously polycondensed with polyols at a molar ratio of 1:1 to 1.8, preferably 1:1.05 to 1.2.

[0034] The obtained polyester polyol has a functionality of 1.9 to 4, 1.9 to 3, 1.9 to 2.6, or 1.9 to 2.3, and a number-average molecular weight of 480 to 4000, preferably 500 to 3200 g / mol, and more preferably 700 to 2600 g / mol. More specifically, the polyester alcohol used is obtained solely by the condensation of a diacid and a diol.

[0035] In some embodiments, this disclosure includes the use of polyether polyols. Polyether polyols can be obtained by known methods, such as anionic polymerization using an alkali metal hydroxide or alkali metal alkoxide as a catalyst in the presence of at least one starting molecule comprising 2 to 3 reactive hydrogen atoms in a bonded form, or cationic polymerization using a Lewis acid, such as antimony pentachloride, or a boron fluoride ether compound formed from one or more epoxides having 2 to 4 carbon atoms in the alkylene moiety. Suitable epoxides are, for example, 1,3-epoxypropane, 1,2-epoxybutane, 2,3-epoxybutane, and preferably ethylene oxide and 1,2-epoxypropane. Monomer tetrahydrofuran may also be used. Useful catalysts also include polymetallic cyanides, i.e., so-called DMC catalysts. Epoxides can be used alone, alternately continuously, or as a mixture. Preferred materials include pure 1,2-epoxypropane or a mixture of 1,2-epoxypropane and ethylene oxide, wherein ethylene oxide is used as an ethylene oxide-terminated block (“EO-terminated”) in an amount greater than 0 to 50%, resulting in a polyol with more than 70% primary OH end groups. Possible starting molecules are preferably 2- and 3-hydroxy alcohols, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, diethylene glycol, dipropylene glycol, 1,4-butanediol, glycerol, or trimethylolpropane. Polyether polyols, preferably polyoxypropylene polyols or polyoxypropylene-polyoxyethylene polyols, preferably have an average functionality of 1.7-3 and a number-average molecular weight of 1000-12,000, preferably 1200-8000 g / mol, especially 1500-6000 g / mol, and even more preferably in the range of 2000 to 6000 g / mol.

[0036] Useful polyols also include polymer-modified polyols, preferably polymer-modified polyester polyols or polyether polyols, more preferably grafted polyether polyols or grafted polyester polyols. Concerning here are so-called polymeric polyols, which typically contain 5 wt% to 60 wt%, preferably 10 wt% to 55 wt%, more preferably 30 wt% to 55 wt%, and especially 40 wt% to 50 wt% of a polymer, preferably a thermoplastic polymer. These polymeric polyester polyols are described, for example, in WO 05 / 098763 and EP-A-250 351 and are generally obtained by free radical polymerization of suitable olefin monomers such as styrene, acrylonitrile, (meth)acrylate, (meth)acrylic acid, and / or acrylamide in a polyester polyol as a grafting group. Side chains are typically formed due to the transfer of free radicals from the growing polymer chain to the polyester polyol or polyether polyol. In addition to graft copolymers, polymeric polyols mainly comprise homopolymers of olefins dispersed in unmodified polyester polyols or polyether polyols, respectively. Preferred embodiments use acrylonitrile and styrene, preferably acrylonitrile and styrene, as monomers. In the polyester polyol or polyether polyol as the continuous phase, the monomers are polymerized using a free radical initiator (typically an azo or peroxide compound) in the presence of other monomers, macromonomers (i.e., unsaturated, free radical polymerizable polyols), a moderator. This method is described, for example, in DE 111 394, U.S. Patent Nos. 3,304,273, 3,383,351, 3,523,093, DE 1,152,536, and DE 1,152,537. During free radical polymerization, the macromonomers are collectively incorporated into the copolymer chain. This results in the formation of block copolymers having polyester or polyether blocks and poly(acrylonitrile-styrene) blocks, which act as compatibilizers at the interface between the continuous and dispersed phases and inhibit the agglomeration of polymeric polyester polyol particles. The proportion of macromonomers is typically in the range of 1 wt% to 20 wt% based on the total weight of monomers used to prepare polymeric polyols.

[0037] Preferably, polymeric polyols, and other polyols (if present), such as polyether polyols, polyester polyols, or mixtures comprising polyether polyols and polyester polyols, are used. The amount of these polymeric polyols may be, for example, from 7 wt% to 90 wt% or from 11 wt% to 80 wt%, based on the total weight of the components. In some embodiments, the proportion of polymeric polyols may be less than 20 wt% based on the total weight of the components, and in other embodiments, polymeric polyols are not used.

[0038] The mixture comprising polyester polyols of the present invention may contain polyols. In this case, the proportion of polyols belonging to polyester polyols is approximately not less than 30 wt% and not less than 70 wt%, and more specifically, it is a polyester polyol specifically used as a higher molecular weight compound, in which case the polymer polyol based on the polyester polyol is treated in a manner similar to that of the polyester polyol.

[0039] In some embodiments, the isocyanate reactive component may also include a chain extender. Useful chain extenders containing active hydrogen typically contain at least two active hydrogen groups, such as diols, dithiols, diamines, or compounds having a mixture of hydroxyl, thiol, and amino groups (such as alkanolamines, aminoalkyl thiols, and hydroxyalkyl thiols). The molecular weight of the chain extender is preferably in the range of about 60 to about 400. As a chain extender constituting a structural unit of polyurethane resins, it is preferably selected from at least one or more low molecular weight diols and low molecular weight diamines. The chain extender can be a substance that simultaneously has hydroxyl and amino groups in its molecule, such as ethanolamine, propanolamine, butanolamine, and combinations thereof.

[0040] Non-limiting examples of suitable diols that can be used as chain extenders include ethylene glycol and higher oligomers of ethylene glycol, including diethylene glycol, triethylene glycol, and tetraethylene glycol; propylene glycol and higher oligomers of propylene glycol, including dipropylene glycol, tripropylene glycol, and tetrapropylene glycol; cyclohexanediol, 1,6-hexanediol, 2-ethyl-1,6-hexanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,3-propanediol, butanediol, neopentanediol, dihydroxyalkylated aromatic compounds, such as bis(2-hydroxyethyl) ethers of hydroquinone and resorcinol; p-xylene-α, α'-diol; p-xylene-α, α'-diol bis(2-hydroxyethyl) ethers; m-xylene-α, α′-diol, and combinations thereof. In one specific embodiment, the chain extender is 1,4-butanediol (BDO).

[0041] Non-limiting examples of organic compounds containing at least two aromatic amine groups can be used as chain extenders for aromatic diamines with a molecular weight of 100 to 1,000. The amine chain extender may contain only aromatically linked primary or secondary (preferably primary) amino groups, and preferably also contains substituents. Examples of such diamines include 1,4-diaminobenzene; 2,4- and / or 2,6-diaminotoluene; 2,4'- and / or 4,4'-diaminodiphenylmethane; 3,3'-dimethyl-4,4'-diaminodiphenylmethane; 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA); 3,5-dimethylthiotoluene-2,4- and / or -2,6-diamine; 1,3,5-triethyl-2,4-diaminobenzene; 1,3,5-triisopropyl-2,4-diaminobenzene; 1-methyl-3,5-diethyl-2,4- and / or -2,6-diaminobenzene (also known as 3,5-diethyltoluene-2,4- and / or -2... 3,6-Dimethyl-2-ethyl-1,3-diaminobenzene; 3,5,3',5'-tetraethyl-4,4-diaminodiphenylmethane; 3,5,3',5'-tetraisopropyl-4,4'-diaminodiphenylmethane; 3,5-diethyl-3',5'-diisopropyl-4,4'-diaminodiphenylmethane; 2,4,6-triethyl-m-phenylenediamine (TEMPDA); 3,5-diisopropyl-2,4-diaminotoluene; 3,5-disec-butyl-2,6-diaminotoluene; 3-ethyl-5-isopropyl-2,4-diaminotoluene; 4,6-diisopropyl-m-phenylenediamine; 4,6-ditert-butyl-m-phenylenediamine 4,6-Diethyl-m-phenylenediamine; 3-Isopropyl-2,6-Diaminotoluene; 5-Isopropyl-2,4-Diaminotoluene; 4-Isopropyl-6-methyl-m-phenylenediamine; 4-Isopropyl-6-tert-butyl-m-phenylenediamine; 4-Ethyl-6-isopropyl-m-phenylenediamine; 4-Methyl-6-tert-butyl-m-phenylenediamine; 4,6-Di-sec-butyl-m-phenylenediamine; 4-Ethyl-6-tert-butyl-m-phenylenediamine; 4-Ethyl-6-sec-butyl-m-phenylenediamine; 4-Ethyl-6-isobutyl-m-phenylenediamine; 4-Isopropyl-6-isobutyl-m-phenylenediamine; 4-Isopropyl-6-sec-butyl-m-phenylenediamine; 4-tert-butyl-6-isobutyl-m-phenylenediamine Diamines; 4-cyclopentyl-6-ethyl-m-phenylenediamine; 4-cyclohexyl-6-isopropyl-m-phenylenediamine; 4,6-dicyclopentyl-m-phenylenediamine; 2,2',6,6'-tetraethyl-4,4'-methylenebisaniline; 2,2',6,6'-tetraisopropyl-4,4'-methylenebisaniline (methylenebisdiisopropylaniline); 2,2',6,6'-tetrasec-butyl-4,4'-methylenebisaniline; 2,2'-dimethyl-6,6'-di-tert-butyl-4,4'-methylenebisaniline; 2,2'-di-tert-butyl-4,4'-methylenebisaniline; and 2-isopropyl-2',6'-diethyl-4,4'-methylenebisaniline. These diamines can also be used as mixtures.

[0042] The isocyanate component and the isocyanate reactive component typically react with an isocyanate index in the range of about 85 to 110, which is greater than or equal to that of the isocyanate index. The term "isocyanate index" is defined as the ratio of NCO groups in the isocyanate component to isocyanate reactive groups in the isocyanate reactive component multiplied by 100. The polyurethane elastomers of this disclosure can be produced by mixing the isocyanate component and the isocyanate reactive component to form a mixture at room temperature or slightly higher temperatures (e.g., 25°C to 45°C). In some embodiments in which the elastic polyurethane elastomer is produced in a mold, it should be understood that the isocyanate component and the isocyanate reactive component can be mixed to form a mixture, and then the mixture can be placed in a mold. For example, the mixture can be poured into an open mold or injected into a closed mold.

[0043] In some embodiments, dehydrating agents may also be used in the production of sprayed polyurethane elastomers according to this disclosure. While not wishing to be bound by the following theory, it is believed that dehydrating agents can help eliminate microporous structures that negatively impact the properties of the resulting article. Dehydrating agents can help absorb residual water and eliminate microporous structures that form and impair the mechanical properties of the resulting sprayed elastomer article. We discuss non-microporous elastomers (where air bubbles create small voids within the elastomer mass that are not interconnected) and their application in this invention. This is categorized as some formulations that do not contain anhydrous (or chemically foaming agents). In this case, the resulting elastic polymer primarily contains urethane bonds (-NH-C(=O)-O-). The contents of sections 0044-0046 require further explanation to clearly illustrate non-microporous and microporous structures; furthermore, the bonds in the polymer arise from the different classifications of formulations claimed by this invention. To discuss low-density elastic materials with foaming agents, we may need a second concept: "a controllable small amount of physical foaming agent in the formulation, which creates voids in the elastomeric bulk structure. This is another novel method for weight reduction, which also leads to a decrease in the density of the elastic polymer. This method is well-aligned with spraying techniques and other elastic material preparation techniques. The loading level of the physical foaming agent can be customized according to the target density, which can result in non-microporous or microporous structures, where the elastic polymer is mainly composed of urethane bonds in the polymer backbone." The third concept... The process involves another mechanism involving chemical foaming agents or water (in this case, without dehydrating agents) for lower-density elastomer materials, where the reactive elastomer polymer contains urethane and urea bonds (-NH-CO-NH-). The water content in the formulation is determined by the target density and the properties required for various applications. The resulting elastomer polymer can be non-microporous or microporous with varying proportions of urethane and urea bonds in its polymer structure. This is not limited to formulations with amine-terminated polyols or chain extenders, resulting in polymers containing urethane and urea bonds.

[0044] Fillers can also be used to reduce the density of sprayed products. Examples of such fillers include hollow glass bulbs (from 3M) and expandable microspheres, such as Expancel (from AkzoNobel).

[0045] The catalyst component can also be used to produce the polyurethane elastomers disclosed herein. Exemplary catalysts include, but are not limited to, N,N-dimethylethanolamine (DMEA), N,N-dimethylcyclohexylamine (DMCHA), bis(N,N-dimethylaminoethyl) ether (BDMAFE), N,N,N',N',N''-pentamethyldiethylenetriamine (PDMAFE), 1,4-diazabicyclo[2,2,2]octane (DABCO), 2-(2-dimethylaminoethoxy)-ethanol (DMAFE), 2-((2-dimethylaminoethoxy)-ethylmethyl-amino)ethanol, 1-(bis(3-dimethylamino)-propyl)amino-2-propanol, N,N',N''-tris(3-dimethylamino-propyl)hexahydrotriazine, dimorpholine diethyl ether (DMDEE), NN-dimethylbenzylamine, N,N,N',N'',N''-pentamethyldipropylenetriamine, N,N'-diethylpiperazine, etc. Specifically, sterically hindered primary, secondary, or tertiary amines may be used, including but not limited to dicyclohexylmethylamine, diisopropylethylamine, dimethylcyclohexylamine, dimethylisopropylamine, methylisopropylbenzylamine, methylcyclopentylbenzylamine, isopropyl sec-butyl-trifluoroethylamine, diethyl-(o-phenylethyl)amine, tri-n-propylamine, dicyclohexylamine, tert-butylisopropanolamine, di-tert-butylamine, cyclohexyl tert-butylamine, di-sec-butylamine, dicyclopentylamine, di(α-trifluoromethylethyl)amine, di(α-phenylethyl)amine, triphenylmethylamine, and 1,1'-diethyl-n-propylamine. Other sterically hindered amines are morpholines, imidazoles, and ether-containing compounds, such as dimorpholino diethyl ether, N-ethylmorpholine, N-methylmorpholine, bis(dimethylaminoethyl) ether, imidazole, n-methylimidazole, and 1,2-dimethylimidazole. Dimorpholine dimethyl ether, N,N,N',N',N",N"-pentamethyldiethylenetriamine, N,N,N',N',N'',N''-pentamethyldipropylenetriamine, bis(diethylaminoethyl) ether, bis(dimethylaminopropyl) ether, or combinations thereof. Non-amine catalysts include, but are not limited to, stannous octoate, dibutyltin dilaurate, dibutyltin thiol, phenylmercuric propionate, lead octoate, potassium acetate / potassium octoate, methylammonium quaternary ammonium salt, iron acetylacetonate, and mixtures thereof. The amount of catalyst used can be from about 0.05 to about 4.00 wt%, from about 0.15 to about 3.60 wt%, or from about 0.40 to about 2.60 wt% of the isocyanate reactive component. In one specific embodiment, the catalyst component may be present in the isocyanate reactive component to catalyze the polyurethane elastomer reaction between the isocyanate component and the isocyanate reactive component. It should be understood that the catalyst component is generally not consumed in the formation of the reaction product between the isocyanate component and the isocyanate reactive component, but it may contain active hydrogen groups that can react with isocyanate groups. That is, the catalyst component typically participates in the polyurethane elastomer formation reaction but is not consumed by it. The catalyst component may include any suitable catalyst or mixture of catalysts known in the art.Suitable catalyst components for the purposes of this disclosure are Dabco® EG and Dabco® 1027, which are commercially available from Evonik Industries of Parsippany, New Jersey.

[0046] Optional additive components may include surfactants, which can be used to control the structure of the polyurethane elastomer, influence the surface structure of the polyurethane elastomer, and improve the miscibility of components in the isocyanate reactive component and the stability of the resulting polyurethane elastomer. Suitable surfactants include any surfactants known in the art, such as siloxanes and nonylphenol ethoxylates. In one embodiment, the surfactant may be a polysiloxane polymer. In a specific embodiment, the polysiloxane polymer is a polydimethylsiloxane-polyoxyethylene block copolymer. If present in the isocyanate reactive component, the surfactant may be selected according to the requirements of the isocyanate reactive component. When used, the amount of surfactant in the isocyanate reactive component may be from about 0.5 to about 6 parts by weight, based on 100 parts by weight of total polyols present in the isocyanate reactive component.

[0047] In some embodiments, the isocyanate component and the isocyanate reactive component may react in the presence of a blowing agent to produce the polyurethane elastomer described herein. As is known in the art, during the polyurethane elastomer formation reaction between the isocyanate component and the isocyanate reactive component, the blowing agent promotes the release of gases that form cavities in the polyurethane elastomer. The blowing agent may be a physical blowing agent, a chemical blowing agent, or a combination of physical and chemical blowing agents.

[0048] The term "physical blowing agent" refers to a blowing agent that does not chemically react with isocyanate components and / or isocyanate reactive components to provide blowing gas. Physical blowing agents can be gaseous or liquid. Liquid physical blowing agents typically evaporate into a gas upon heating and from the resulting polyurethane elastomer. Suitable physical blowing agents used in this subject matter disclosure may include liquid carbon dioxide (CO2), HCFCs, HFOs, pentane and all its isomers, acetone, entrained air, other inert gases, or combinations thereof. The most typical physical blowing agents typically have, but are not limited to, zero ozone depletion potential, such as, but not limited to, [missing information]. trans -1-Chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)).

[0049] The term chemical blowing agent refers to a blowing agent that reacts chemically with an isocyanate component or with other components to release gas. Examples of chemical blowing agents suitable for the purposes of this disclosure include formic acid, methyl formate, water, and combinations thereof. The blowing agent is typically present in the isocyanate reactive component in an amount of about 0.5 to about 20 parts by weight, based on 100 parts by weight of total polyol present in the isocyanate reactive component.

[0050] It should be understood that physical foaming agents and chemical foaming agents can also be used in combination. Such combinations can include, but are not limited to, water and entrained air.

[0051] The tear strength of a sample can be tested according to ISO 34-1. Tear strength is a measure of the force required to continue tearing an elastomer after delamination or fracture has begun, and is expressed in kg / cm.

[0052] Tensile strength, tensile modulus, and mean elongation at break can be tested according to DIN 53504. Tensile strength at break is the ratio of the breaking force to the initial cross-sectional area of ​​the elastomer specimen, expressed in MPa. Yield tensile stress is the ratio of the maximum measured force to the initial cross-sectional area of ​​the specimen, expressed in MPa. Tensile modulus is the ratio of stress (force per unit area) along the axis to strain (deformation to initial length) along the axis, expressed in MPa. Elongation at break is the ratio of the change in fracture length to the initial gauge length of the specimen, expressed as a percentage (%).

[0053] The density of the sample can be tested according to ISO 1183. Density is the mass per volume of the elastomer specimen and is expressed in g / cm³. 3 express.

[0054] The apparent viscosity of the polyols in this disclosure can be tested according to ASTM D2196. Apparent viscosity is the shear stress applied to the fluid divided by the shear rate and is expressed in cps.

[0055] Specific examples of this disclosure will now be referenced. It should be understood that these examples are provided to illustrate exemplary embodiments and are therefore not intended to limit the scope of this disclosure.

[0056] The present invention will be further described with reference to the following embodiments; however, it should be understood that the invention is not limited to such examples. Rather, given this disclosure which describes the present best mode for practicing the invention, many modifications and variations are presented to those skilled in the art without departing from the scope and spirit of the invention. All changes, modifications, and variations within the equivalent meaning and scope of the claims are to be considered within the scope of the claims.

[0057] The invention has been described in an illustrative manner. It should be understood that the terminology used is intended to be descriptive in nature and not restrictive.

[0058] In view of the foregoing teachings, many modifications and variations of the present invention are possible. Therefore, this disclosure may be practiced in ways other than those specifically described within the scope of the appended claims.

[0059] Example Polyol 1 is a polyester polyol initiated by adipic acid-ethylene glycol-1,4-butanediol, with an average number of hydroxyl groups of 56.

[0060] Polyol 2 is a polyester polyol initiated by adipic acid-ethylene glycol-1,4-butanediol. Its structure is different from that of polyol 1, and its average number of hydroxyl groups is also 56.

[0061] Polyol 3 is a polyester polyol initiated by adipic acid-ethylene glycol-1,4-butanediol, with an average number of hydroxyl groups of 80.

[0062] Polyol 4 is a grafted polyester polyol with an average hydroxyl number of 60.

[0063] Polyol 5 is a glycerol-initiated polyether polyol containing propylene oxide and ethylene oxide, with 35 hydroxyl groups.

[0064] Polyol 6 is a polyether polyol initiated by dipropylene glycol, with 29 hydroxyl groups.

[0065] Polyol 7 is a grafted polyol with 32% solids (1:2 acrylonitrile:styrene) and 24 hydroxyl groups.

[0066] Polyol 8 is a polytetrahydrofuran polyether polyol with 110 hydroxyl groups.

[0067] Polyol 9 is a polytetrahydrofuran polyether polyol with 56 hydroxyl groups.

[0068] Chain extender 1 is 1,4-butanediol; chain extender 2 is ethylene glycol.

[0069] Catalyst 1 is triethylenediamine diluted in ethylene glycol, such as DABCO EG; Catalyst 2 is a delayed-acting tertiary amine diluted in ethylene glycol, such as DABCO 1027; Catalyst 3 is a tin catalyst, such as Fomorez UL-22; Catalyst 4 is a bismuth neodecanoate / zinc neodecanoate catalyst, such as Bicat; Catalyst 5 is a triethylenediamine catalyst diluted in 1,4-butanediol, such as DABCO S25; Catalyst 6 is a delayed-acting tertiary amine diluted in 1,4-butanediol, such as DABCO 1028. (Catalyst 7 is triethylenediamine dissolved in dipropylene glycol, such as Dabco® 33-LV; Catalyst 8 is a DBU-based delayed-acting tertiary amine, such as Polycat SA-102.) Additive 1 is a defoamer, such as defoamer A; Additive 2 is a dehydrating agent, such as molecular sieve 3A, or a mixture containing molecular sieve 3A; Additive 3 is fumed silica, such as Areosil R 972; Additive 4 is a colorant, such as GrayRepitan; Additive 5 is a light stabilizer, such as TINUVIN 123 HALS and TINUVIN 123 HALS.

[0070] Isocyanate prepolymer 1 is Elastopan® 41640T isocyanate; isocyanate prepolymer 2 is Lupranate® MP102 (both were purchased from BASF Corporation of Florham Park, NJ).

[0071] Table 1. Polyol Combinations - Examples and Properties

[0072] Notes: Density (g / cm3): 1.01±0.01, ISO 1183; Thickness (mm): 1.1±0.1 Table 2. Chain extenders - Examples and properties

[0073] Notes: Density (g / cm3): 1.01±0.01, ISO 1183; Thickness (mm): 1.1±0.1 Table 3: Chain extenders - Combinations and properties

[0074] Notes: Density (g / cm3): 1.01±0.01, ISO 1183; Thickness (mm): 1.1±0.1 Table 4. Cross-linking Agents / Cross-linkers - Examples and Properties

[0075] Note: Density (g / cm3): 1.01±0.01, ISO 1183 Thickness (mm): 1.1 ± 0.1 Table 4. Physical properties of sprayed polyether polyurethane at lower densities

[0076] Note: Density (g / cm3), 0.80±0.05 ISO 1183 Thickness (mm): 1.1 ± 0.1 Note: Density (g / cm3), 0.80±0.05 ISO 1183 Thickness (mm): 1.1 ± 0.1 Table 5. Physical properties of sprayed polyester polyurethane at lower densities

[0077] Note: Density (g / cm3), 0.80±0.05 ISO 1183 Thickness (mm): 1.1 ± 0.1 Note: Density (g / cm3), 0.75±0.05 ISO 1183 Thickness (mm): 1.1 ± 0.1 like Figure 1 The curve shown Figure 1 For a complete view of the dataset, the performance of cast samples (without aeration) is compared to that of sprayed samples, which have reduced density due to aeration. As density decreases, tensile strength and modulus also decrease with decreasing ultimate elongation. Samples A, B, and C are all examples of the polyester chemicals described in this patent. Typical tensile curves for full-density polyethers are provided for comparison. All ester-based examples show superior performance compared to the ether examples, even at low densities.

[0078] like Figure 2 The curve shown Figure 2 Enlarged views of the low-strain regions of samples A, B, and C (all examples of ester chemicals described herein). The graphs illustrate the manipulation of ester chemicals and spray density to provide the desired tensile modulus.

[0079] Using only conventional experiments, those skilled in the art will recognize or be able to identify numerous equivalents of the particular compositions and processes described herein. Such equivalents are considered to be within the scope of this disclosure and are included in the appended claims.

Claims

1. A sprayable polyurethane elastomer, comprising: (a) Isocyanate-functionalized urethane prepolymers derived from monomers diphenylmethane diisocyanate (MMDI) and polyester polyols; and (b) Isocyanate reactive components, comprising: (i) 60 to 98 parts by weight of a first polyol of the isocyanate reactive component, wherein the first polyol is a polyol with 30 to 200 mg KOH / g of hydroxyl groups, and the first polyol is a polyester polyol. The density of the sprayed polyurethane elastomer is 0.60-0.95 g / cm³. 3 , The viscosity of sprayed polyurethane elastomer is approximately 2500-6800 cps at 25°C, while the viscosity of isocyanate-functionalized urethane prepolymer is 1000-1100 cps at 25°C.

2. The sprayable polyurethane elastomer according to claim 1, wherein the amount of the first polyol is 70 to 95 parts by weight of the isocyanate reactive component.

3. The sprayable polyurethane elastomer according to claim 1, wherein the amount of the first polyol is 80 to 95 parts by weight of the isocyanate reactive component.

4. The sprayable polyurethane elastomer according to claim 1, wherein the weight-average molecular weight of the first polyol is 500 to 5000 g / mol.

5. The sprayable polyurethane elastomer according to claim 1, wherein the first polyol is a polyester polyol initiated by adipic acid-ethylene glycol-1,4-butanediol.

6. The sprayable polyurethane elastomer according to claim 1, further comprising a catalyst in an amount of 0.05 to 4.00 parts by weight of the isocyanate reactive component.

7. The sprayable polyurethane elastomer according to claim 1 further comprises a chain extender with a molecular weight of 60 to 400.

8. The sprayable polyurethane elastomer according to claim 1, wherein the isocyanate reactive component further comprises a second polyol.

9. The sprayable polyurethane elastomer according to claim 8, wherein the second polyol is a polyester polyol.

10. The sprayed polyurethane elastomer according to claim 1, wherein the density of the elastomer is lower than that of the non-sprayed elastomer.

11. The sprayable polyurethane elastomer of claim 1, wherein the elastomer can be applied to a mold having high thermal conductivity or low thermal conductivity.

12. The sprayable polyurethane elastomer of claim 1, wherein the elastomer can be applied to non-synthetic textiles, synthetic textiles, glass fiber mats, or carbon fiber mats to produce reinforced composite materials.

13. The sprayable polyurethane elastomer of claim 1, wherein the elastomer can be applied to non-synthetic or synthetic fabrics to produce reinforced composite materials.

14. The sprayed polyurethane elastomer according to claim 12 or 13, wherein the reinforced composite material can be used to form industrial or consumer articles.

15. The sprayable polyurethane elastomer of claim 14, wherein the industrial or consumer product comprises clothing, footwear, automotive components, tools, appliances, outdoor products, and landscaping materials.

16. The sprayable polyurethane elastomer of claim 14, wherein the article is flexible or rigid.

17. A method for preparing the sprayed polyurethane elastomer of claim 1, comprising the following steps: MMDI is reacted with polyester polyols to form isocyanate-functionalized urethane prepolymers. Polyols are blended to form isocyanate reactive components; The isocyanate prepolymer and the isocyanate reactive component are mixed at an isocyanate index of 100 to 110 to form a polyurethane elastomer, wherein the amount of the polyester polyol with a hydroxyl number of 30 to 200 mg KOH / g is 60 to 98 parts by weight of the isocyanate reactive component.

18. The method of claim 17, further comprising the step of reducing the density of the elastomer.

19. The method of claim 18, wherein the step of reducing the density of the elastomer comprises air injection, adding a physical foaming agent, adding a chemical foaming agent, adding a nucleating agent, or adding a filler.

20. The method of claim 19, wherein the nucleating agent comprises dry air or nitrogen, and / or wherein the filler comprises a hollow glass bubble or expandable microspheres.

21. A method for producing articles for consumer or industrial use, The article comprises one or more outer layers, the outer layers comprising an elastomeric composition applied by spraying. The one or more outer layers comprise the same or different elastomeric compositions applied by one or more spraying systems. Furthermore, the elastomer composition comprises a product of reacting MMDI with a polyester polyol to form an isocyanate-functionalized urethane prepolymer, the reaction comprising blending the polyol to form an isocyanate reactive component; and mixing the isocyanate prepolymer and the isocyanate reactive component at an isocyanate index of 100 to 110 to form a polyurethane elastomer, wherein the amount of the polyester polyol having a hydroxyl number of 30 to 200 mg KOH / g is 60 to 98 parts by weight of the isocyanate reactive component. The viscosity of sprayed polyurethane elastomer is approximately 2500-6800 cps at 25°C, while the viscosity of isocyanate-functionalized urethane prepolymer is 1000-1100 cps at 25°C.

22. The method of claim 21, wherein the spraying system comprises layer-by-layer spraying.

23. The method of claim 22, wherein the production rate of the spraying system comprises 5-100 g / s, 6-30 g / s, or 8-20 g / s.

24. The method of claim 21, wherein the thickness of each sprayed layer is in the range of 0.1-5.0 mm, 0.2-3.0 mm, 0.4-2.0 mm, or 0.5-1.5 mm.

25. A sprayable polyurethane elastomer, comprising: (a) An isocyanate-functionalized urethane prepolymer derived from monomer diphenylmethane diisocyanate (MMDI) and a first polyol, wherein the first polyol is a polyester polyol; and (b) Isocyanate reactive components, comprising: (i) A second polyol comprising 60 to 98 parts by weight of the isocyanate reactive component, wherein the second polyol is a polyol having a hydroxyl number of 30 to 200 mg KOH / g. The density of the sprayed polyurethane elastomer is 0.60-0.95 g / cm³. 3 , The viscosity of sprayed polyurethane elastomer is approximately 2500-6800 cps at 25°C, while the viscosity of isocyanate-functionalized urethane prepolymer is 1000-1100 cps at 25°C.

26. The sprayable polyurethane elastomer of claim 25, wherein the isocyanate-functionalized urethane prepolymer comprises Elastopan® 41640T isocyanate or Lupranate® MP102.

27. The sprayable polyurethane elastomer according to claim 25, wherein the second polyol comprises adipic acid-ethylene glycol-1,4-butanediol-initiated polyester polyol or grafted polyester polyol.

28. The sprayable polyurethane elastomer according to claim 25, further comprising one or more chain extenders.

29. The sprayable polyurethane elastomer of claim 28, wherein the chain extender comprises a molecular weight of 60 g / mol to 400 g / mol.

30. The sprayable polyurethane elastomer of claim 28, wherein the chain extender comprises 1,4-butanediol or ethylene glycol.

31. The sprayed polyurethane elastomer according to any one of claims 25 to 30, further comprising one or more catalysts.

32. The sprayable polyurethane elastomer according to claim 25, further comprising a catalyst in an amount of 0.05 to 4.00 parts by weight of the isocyanate reactive component.

33. The sprayable polyurethane elastomer of claim 31, wherein the catalyst comprises triethylenediamine diluted in ethylene glycol, DABCO® EG; a delayed-action tertiary amine diluted in ethylene glycol, DABCO® 1027; a tin catalyst, Fomorez UL-22; a bismuth neodecanoate and zinc neodecanoate catalyst, Bicat; triethylenediamine diluted in 1,4-butanediol catalyst, DABCO® S25; a delayed-action tertiary amine diluted in 1,4-butanediol, DABCO® 1028; triethylenediamine dissolved in dipropylene glycol, DABCO® 33-LV; and a DBU-based delayed-action tertiary amine, Polycat SA-102.

34. The sprayable polyurethane elastomer according to claim 25, further comprising one or more additives.

35. The sprayable polyurethane elastomer according to claim 34, wherein the additive comprises a defoamer, a dehydrating agent, fumed silica, a colorant, or a light stabilizer.

36. The sprayable polyurethane elastomer of claim 34, wherein the additive comprises defoamer A, molecular sieve 3A, Areosil R 972, or TINUVIN 123 HALS.

37. The sprayable polyurethane elastomer according to claim 25, wherein the amount of the second polyol is 70 to 95 parts by weight of the isocyanate reactive component.

38. The sprayable polyurethane elastomer according to claim 25, wherein the amount of the second polyol is 80 to 95 parts by weight of the isocyanate reactive component.

39. The sprayable polyurethane elastomer according to claim 25, wherein the second polyol has a weight-average molecular weight of 500 to 5000 g / mol.

40. The sprayable polyurethane elastomer of claim 25, wherein the isocyanate reactive component further comprises a third polyol.

41. The sprayable polyurethane elastomer according to claim 40, wherein the third polyol is a polyester polyol.

42. The sprayed polyurethane elastomer of claim 25, wherein the density of the elastomer is lower than that of the unsprayed elastomer.

43. The sprayable polyurethane elastomer of claim 25, wherein the elastomer can be applied to a mold having high thermal conductivity or low thermal conductivity.

44. The sprayable polyurethane elastomer of claim 25, wherein the elastomer can be applied to non-synthetic textiles, synthetic textiles, glass fiber mats, or carbon fiber mats to produce reinforced composite materials.

45. The sprayable polyurethane elastomer of claim 25, wherein the elastomer can be applied to non-synthetic or synthetic fabrics to produce reinforced composite materials.

46. ​​The sprayed polyurethane elastomer according to claim 44 or 45, wherein the reinforced composite material can be used to form industrial or consumer articles.

47. The sprayed polyurethane elastomer of claim 46, wherein the industrial or consumer product comprises clothing, footwear, automotive components, tools, appliances, outdoor products, and landscaping materials.

48. The sprayed polyurethane elastomer of claim 47, wherein the article is flexible or rigid.

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