Thermoplastic elastomer composition and method for producing the same

Abstract

A variety of thermoplastic elastomer (TPE) compositions comprising a rubber component, the rubber component comprising: (i) a high molecular weight styrene-ethylene-butylene-styrene (SEBS) polymer having a number average molecular weight of 75,000 g / mol to 300,000 g / mol; and (ii) a low molecular weight SEBS polymer having a polystyrene content of less than about 30 wt% and a number average molecular weight of 10,000 g / mol to less than 75,000 g / mol. The TPE compositions further comprise a polyolefin and an oil. The TPE compositions are suitable for use in rotational molding applications to form a variety of rotational molded products.

Description

[0001] Priority requirements

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 570,801, filed March 27, 2024, with Attorney General’s Case No. 1202403, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to thermoplastic elastomer (TPE) compositions, and more specifically, to TPE compositions for rotational molding applications. Background Technology

[0004] Conventional rotary molding is typically performed on a rotary table machine, where multiple independent arms circulate through different stations (e.g., heating chambers, cooling zones, and loading / unloading zones). Each arm of the rotary table machine typically houses one or more molds that rotate independently on a platform that rotates simultaneously in a vertical plane, thus achieving biaxial rotation. This type of rotation allows for the formation of hollow parts, and the rotation is typically performed at low rotational speeds (e.g., 2–10 rpm) in each direction. Therefore, polymer powder or particulate material can be loaded into the mold, heated by biaxial rotation in a low shear rate environment, cooled by continuous biaxial rotation, and then removed from the mold.

[0005] Rotational molding begins with plastics, initially using polyvinyl chloride (PVC) to manufacture toys (such as doll heads), and then expanding to include polyethylene and other resins. Furthermore, the low-shear conditions of rotational molding can prevent materials from successfully filling the mold, reducing the detail in the resulting molded product. Additionally, semi-crystalline polyolefins (such as polypropylene (PP) and polyethylene (PE)) tend to exhibit low zero-shear viscosity, but the range of surface properties, tactile qualities, and hardness achievable with such materials is limited. For example, for rotational molding furniture applications, non-rigid surfaces are desirable, necessitating the use of materials different from PE. Although thermoplastic elastomers (TPEs) have replaced PVC in other applications due to their recyclability and potential for production from bio-derived feedstocks, TPEs, especially styrene-based systems, are generally unsuitable for rotational molding due to their inherently high viscosity in the molten state under low-shear conditions.

[0006] Therefore, alternative materials are still needed for rotational molding applications. Summary of the Invention

[0007] The following is a brief overview of the subjects described in more detail herein. This overview is not intended to limit the scope of the claims.

[0008] According to a first aspect of this disclosure, the composition comprises a rubber component, a polyolefin, and an oil. The rubber component comprises: (i) a high molecular weight styrene-ethylene-butene-styrene (SEBS) polymer having a number-average molecular weight of 75,000 g / mol to 300,000 g / mol; and (ii) a low molecular weight SEBS polymer having a polystyrene content of less than about 30% by weight and a number-average molecular weight of 10,000 g / mol to less than 75,000 g / mol.

[0009] In any aspect of this document, when measured according to ASTM D4440 using strain amplitude equal to or less than 5%, the composition may exhibit less than 100 Pa at 0.1 rad / s in the temperature range of 200–250 °C. The complex viscosity of s. Low molecular weight SEBS polymers can be triblock SEBS polymers. Triblock SEBS polymers may contain an ethylene / butene mesoblock and one or more styrene-containing end blocks.

[0010] In some respects, polyolefins include polypropylene homopolymers, polypropylene random copolymers, high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and combinations thereof. Polyolefins may contain polyethylene having a melt flow index greater than or equal to 40 g / 10 min, measured according to ASTM D1238 at 190°C and 2.16 kg. Polyolefins may contain polypropylene having a melt flow index greater than or equal to 50 g / 10 min, measured according to ASTM D1238 at 230°C and 2.16 kg.

[0011] In any aspect, the oil may be present in an amount greater than or equal to about 20% by weight, based on the total weight of the composition. The oil may contain polyalphaolefin (PAO) or mineral oil. The oil may contain bio-derived oil. In some aspects, the oil has a flash point greater than about 230°C, measured according to ASTM D92. The oil may have a kinematic viscosity less than or equal to 105 cSt, measured according to ASTM D445 at 40°C.

[0012] In any of the foregoing aspects, the high molecular weight SEBS polymer may have a number average molecular weight of 75,000 g / mol to 125,000 g / mol. The low molecular weight SEBS polymer may have a number average molecular weight of 40,000 g / mol to 70,000 g / mol or 55,000 g / mol to 65,000 g / mol. The ratio of the amount of rubber composition to the amount of oil may be 1:1. The ratio of the amount of high molecular weight SEBS polymer to the amount of low molecular weight SEBS polymer may be 1.1:1 to 1.5:1.

[0013] In some aspects disclosed herein, the composition can be formed into a plurality of particles having an average particle size of less than about 1,000 μm. The composition can be formed into a plurality of particles by low-temperature milling. The plurality of particles may comprise a plurality of microparticles.

[0014] This disclosure also provides rotationally molded articles comprising any of the formulations described above. The rotationally molded articles may have a wall thickness of about 0.5 mm to about 50 mm. The rotationally molded articles may contain voids therein.

[0015] In various aspects, methods of forming an article include forming a rotationally molded article by rotationally molding a composition according to any aspect described herein. In some aspects, the method includes forming a rotationally molded article by rotationally molding a composition comprising a rubber component, a polyolefin, and an oil. The rubber component comprises: (i) a high molecular weight styrene-ethylene-butene-styrene (SEBS) polymer having a number average molecular weight of 75,000 g / mol to 300,000 g / mol; and (ii) a low molecular weight SEBS polymer having a polystyrene content of less than about 30% by weight and a number average molecular weight of 10,000 g / mol to 75,000 g / mol. In some aspects, the method further includes filling voids in the molded article at least partially with foam.

[0016] The above summary presents a simplified overview to provide a basic understanding of some aspects of the systems and / or methods discussed herein. This summary is not an exhaustive overview of the systems and / or methods discussed herein. It is not intended to identify key / important elements or define the scope of such systems and / or methods. Its sole purpose is to present some ideas in a simplified form as a prelude to the more detailed description that follows. Attached Figure Description

[0017] The general inventive concept, as well as its illustrative embodiments and advantages, are described in more detail below with reference to the accompanying drawings, in which:

[0018] Figure 1 Photographs of sample specimens prepared from the compositions described in Example 1 are shown, demonstrating resistance to removal by ink pen and permanent marker at 0 and 168 hours.

[0019] Figure 2A The image shows a photograph of a rotationally molded part prepared from the composition described in Example 3;

[0020] Figure 2B This is an enlarged image of a rotary molded part prepared from the composition described in Example 3, showing surface pits;

[0021] Figure 2C yes Figure 2BThe negative of the image provides a clearer resolution of the pits on the surface;

[0022] Figure 3A This is a graph of thermogravimetric analysis of various white mineral oils and polyalphaolefin oils, where temperature (°C) is shown on the x-axis and weight (%) is shown on the y-axis.

[0023] Figure 3B This is a graph of thermogravimetric analysis of various white mineral oils and polyalphaolefin oils, where time (minutes) is shown on the x-axis and weight (%) is shown on the y-axis;

[0024] Figure 3C The images are photographs of surfaces prepared from the formulations described in Example 4 at 170°C, 180°C, and 190°C, showing that the pits decrease as the temperature increases;

[0025] Figure 4A This is a photograph of the experimental setup in Example 5;

[0026] Figure 4B The photograph shows a component prepared from formulation I as described in Example 5;

[0027] Figure 4C yes Figure 4B An enlarged view of the component shown;

[0028] Figure 5A This is a SAOS temperature scan plot of formulation OR at 1% strain and 0.5 rad / s, where temperature (°C) is on the x-axis, storage modulus and loss modulus (Pa) are on the left-hand y-axis, and tan(δ) is on the right-hand y-axis; and

[0029] Figure 5B These are SAOS temperature scans of formulation P at various temperatures (170℃, 180℃, 190℃, and 200℃) at 1% strain, and temperature scans of formulation I at 240℃ at 1% strain. The angular frequency (rad / s) is on the x-axis, and the complex viscosity (Pa) is... s) on the y-axis. Detailed Implementation

[0030] This document discloses low-viscosity thermoplastic elastomer (TPE) compositions and methods for manufacturing the same, the TPE compositions comprising a rubber component, a polyolefin, and an oil. Specifically, in all aspects described herein, the TPE compositions comprise a rubber component, a polyolefin, and an oil, the rubber component comprising a high molecular weight styrene-ethylene / butene-styrene (SEBS) polymer and a low molecular weight SEBS polymer. The blend of the high molecular weight SEBS polymer and the low molecular weight SEBS polymer provides a low melt viscosity under low shear conditions, making the TPE compositions suitable for rotational molding applications while reducing or eliminating pitting on the surface. Products formed from the TPE compositions also exhibit enhanced cleanability for permanent markers and inks. Other advantages are possible and contemplated, and can be achieved according to the following disclosure.

[0031] The terminology set forth herein is used only to describe various aspects and should not be construed as limiting the overall disclosure. Unless otherwise specified or clearly implied in the context of the reference, all references to the singular characteristics or limitations of this disclosure shall include the corresponding plural characteristics or limitations, and vice versa. Unless otherwise specified, “a,” “an,” “the,” and “at least one / at least one” are used interchangeably. Furthermore, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include their plural forms unless the context clearly indicates otherwise.

[0032] Unless otherwise expressly defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0033] Unless otherwise expressly stated, it is not intended to interpret any method disclosed herein as requiring its steps to be performed in a particular order, nor is it intended to interpret any article of manufacture described herein as requiring its individual components to have a particular order or orientation.

[0034] The use of the term "comprising" in the specification or claims is intended to be inclusive in a manner similar to that of the term "including," as interpreted when used as a transitional word in the claims. Similarly, the use of the term "or" (e.g., A or B) is intended to mean "A or B or both." The term "A or B but not both" will be used when the applicant intends to express "only A or B but not both." Therefore, the use of the term "or" herein is inclusive, not exclusive.

[0035] Any composition described in this disclosure may comprise, consist of, or consist substantially of the essential elements of this disclosure described herein, as well as any additional or optional elements described herein, or any other elements useful in rotational molding applications.

[0036] All percentages, parts and ratios used herein are based on the “dry weight” of the total mixture, i.e., excluding solvents, unless otherwise specified.

[0037] All ranges and parameters disclosed herein, including but not limited to percentages, fractions, and ratios, are to be understood as including any and all subranges assumed and contained therein, as well as every number between the endpoints. For example, the range “1 to 10” should be considered to include any and all subranges (e.g., 1 to 6.1, or 2.3 to 9.4) starting from a minimum value of 1 or greater and ending with a maximum value of 10 or less, as well as every integer contained within that range (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10). Ranges may be expressed as “about” a particular value and / or “about” another particular value. When such ranges are expressed, another embodiment includes from that particular value and / or to that other particular value. Similarly, when values ​​are expressed as approximations, the particular value will be understood to form another embodiment by using the antecedent “about”. It will be further understood that the endpoints of each range are significant relative to and independent of the other endpoint.

[0038] As described herein, the term "% by weight" refers to the weight fraction of each component based on the total weight of the thermoplastic layer composition, unless otherwise stated.

[0039] Furthermore, as used herein, the term “exemplary” means used as an illustration or instance of something, and is not intended to indicate preference.

[0040] As described in this article, the term “melt flow index” refers to the ability of a material’s melt to flow under pressure, as measured according to ASTM D1238 at a given temperature and a given weight.

[0041] As used herein, the term “thermoplastic” refers to a polymer that softens when exposed to heat and returns to its original state at room temperature.

[0042] In all the aspects provided herein, thermoplastic elastomer (TPE) compositions comprising a rubber component, a polyolefin, and an oil are disclosed. In any aspect described herein, the rubber component comprises a high molecular weight SEBS polymer and a low molecular weight SEBS polymer. The composition exhibits a relatively low melt viscosity (e.g., less than 100 Pa) at low shear rates (e.g., 0.1 rad / s) when measured at 200 °C. Products made by rotational molding of the composition can have reduced surface pitting and exhibit enhanced cleanability for permanent markers and inks. Depending on the specific aspect, other advantages can be achieved, which will now be described in more detail.

[0043] rubber components

[0044] As described above, the low-viscosity TPE composition may contain a rubber component comprising a high molecular weight SEBS polymer and a low molecular weight SEBS polymer, the molecular weights of which are defined as follows. In each aspect, the rubber component may consist of, or substantially consist of, the high molecular weight SEBS polymer and the low molecular weight SEBS polymer. The rubber component is present in the composition in an amount of about 20% to about 50% by weight, based on the total weight of the composition. For example, the rubber component may be included in the composition in amounts of about 20% to about 50% by weight, about 25% to about 50% by weight, about 30% to about 50% by weight, about 35% to about 50% by weight, about 40% to about 50% by weight, about 45% to about 50% by weight, about 20% to about 45% by weight, about 25% to about 45% by weight, about 30% to about 45% by weight, about 35% to about 45% by weight, about 40% to about 45% by weight, about 20% to about 40% by weight, about 25% to about 40% by weight, about 30% to about 40% by weight, about 35% to about 40% by weight, about 20% to about 35% by weight, about 25% to about 35% by weight, or about 30% to about 35% by weight, including any and all ranges and subranges containing any of these endpoints.

[0045] High molecular weight SEBS polymer

[0046] High molecular weight SEBS polymers are styrene block copolymers comprising blocks of styrene-ethylene and butene-styrene polymers. High molecular weight SEBS polymers can be diblock or triblock copolymers based on styrene-ethylene and butene-styrene. In any aspect described herein, the high molecular weight SEBS polymer may have a styrene content greater than or equal to about 20%. However, it is contemplated that in any aspect, the high molecular weight SEBS polymer may have a styrene content less than 20%. Therefore, the styrene content is not particularly limited.

[0047] In all the aspects presented herein, the high molecular weight SEBS polymers have a number-average molecular weight (Mg) greater than or equal to 75,000 g / mol. n In some respects, high molecular weight SEBS polymers may have an M value greater than or equal to 80,000 g / mol, greater than or equal to 90,000 g / mol, or even greater than or equal to 100,000 g / mol. nIn these or other respects, high molecular weight SEBS can have an M value of less than or equal to 300,000 g / mol, less than or equal to 250,000 g / mol, less than or equal to 200,000 g / mol, less than or equal to 175,000 g / mol, less than or equal to 150,000 g / mol, less than or equal to 140,000 g / mol, or even less than or equal to 130,000 g / mol. nFor example, high molecular weight SEBS can have concentrations greater than or equal to 75,000 g / mol and less than or equal to 300,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 250,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 200,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 175,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 150,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 140,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 130,000 g / mol; greater than or equal to 75,000 g / mol and less than or equal to 125,000 g / mol; greater than or equal to 80,000 g / mol; and so on. The following are considered high g / mol values: ≥300,000 g / mol, ≥80,000 g / mol, ≥250,000 g / mol, ≥80,000 g / mol, ≥200,000 g / mol, ≥80,000 g / mol, ≤175,000 g / mol, ≥80,000 g / mol, ≤150,000 g / mol, ≥80,000 g / mol, ≤140,000 g / mol, ≥80,000 g / mol, ≤130,000 g / mol, ≥80,000 g / mol, ≤125,000 g / mol, ≥90,000 g / mol, ≤300,000 g / mol, ≥90,000 g / mol, ≥90,000 g / mol, ≤300,000 g / mol, ≥90,000 g / mol, ≤300,000 g / mol, ≤9 ... The following values ​​are considered acceptable: g / mol less than or equal to 250,000 g / mol; greater than or equal to 90,000 g / mol less than or equal to 200,000 g / mol; greater than or equal to 90,000 g / mol less than or equal to 175,000 g / mol; greater than or equal to 90,000 g / mol less than or equal to 150,000 g / mol; greater than or equal to 90,000 g / mol less than or equal to 140,000 g / mol; greater than or equal to 90,000 g / mol less than or equal to 130,000 g / mol; greater than or equal to 90,000 g / mol less than or equal to 125,000 g / mol; greater than or equal to 100,000 g / mol less than or equal to 300,000 g / mol; greater than or equal to 100,000 g / mol less than or equal to 25 ...M with a concentration of 000 g / mol and less than or equal to 200,000 g / mol, greater than or equal to 100,000 g / mol and less than or equal to 175,000 g / mol, greater than or equal to 100,000 g / mol and less than or equal to 150,000 g / mol, greater than or equal to 100,000 g / mol and less than or equal to 140,000 g / mol, or even greater than or equal to 100,000 g / mol and less than or equal to 130,000 g / mol, or greater than or equal to 100,000 g / mol and less than or equal to 125,000 g / mol n , or any and all subranges formed by any of these endpoints. In each aspect, gel permeation chromatography (GPC) and polystyrene (PS) standards were used to determine the M of the SEBS polymer. n .

[0048] High molecular weight SEBS may be included in the rubber component in an amount of about 40% to about 80% by weight, based on the total weight of the rubber component. In the aspects described herein, high molecular weight SEBS is included in amounts of about 40% to about 80% by weight, about 40% to about 75% by weight, about 40% to about 70% by weight, about 40% to about 65% by weight, about 40% to about 60% by weight, about 40% to about 55% by weight, about 40% to about 50% by weight, about 45% to about 80% by weight, about 45% to about 75% by weight, about 45% to about 70% by weight, about 45% to about 65% by weight, about 45% to about 60% by weight, about 45% to about 55% by weight, about 50% to about 80% by weight, and about 50% to about 75% by weight. The amounts of about 50% to about 70% by weight, about 50% to about 65% by weight, about 50% to about 60% by weight, about 50% to about 55% by weight, about 55% to about 80% by weight, about 55% to about 75% by weight, about 55% to about 70% by weight, about 55% to about 65% by weight, about 55% to about 60% by weight, about 60% to about 80% by weight, about 60% to about 75% by weight, about 60% to about 70% by weight, or about 60% to about 65% by weight are included in the rubber component, based on the total weight of the rubber component, including any and all subranges formed by any of these endpoints.

[0049] Low molecular weight SEBS polymer

[0050] The rubber component also includes a low molecular weight SEBS polymer. The low molecular weight SEBS polymer is a styrene block copolymer comprising blocks of styrene-ethylene and butene-styrene polymers. The low molecular weight SEBS polymer can be a diblock or triblock copolymer based on styrene-ethylene and butene-styrene. Although diblocks can be used in the aspects described herein, products formed from compositions comprising diblock low molecular weight SEBS polymers may lack the mechanical properties (e.g., tear strength) achievable using triblock polymers. In any aspect described herein, the low molecular weight SEBS polymer is a triblock copolymer having ethylene-butene mesoblocks and styrene end blocks.

[0051] In any aspect described herein, the low molecular weight SEBS polymer has a styrene content of less than about 30%. For example, the low molecular weight SEBS polymer may have a styrene content of less than about 27%, less than about 25%, less than about 22%, or less than about 20%.

[0052] In all the aspects presented herein, the low molecular weight SEBS polymer has an M value of less than or equal to 75,000 g / mol. n In some respects, low molecular weight SEBS polymers have an M0 of less than 75,000 g / mol, less than or equal to 50,000 g / mol, or even less than or equal to 25,000 g / mol. n In some respects, low molecular weight SEBS can have an M value greater than or equal to 10,000 g / mol, greater than or equal to 25,000 g / mol, or greater than or equal to 50,000 g / mol. n. For example, low molecular weight SEBS can have concentrations from 10,000 g / mol to less than 75,000 g / mol, 10,000 g / mol to 70,000 g / mol, 10,000 g / mol to 60,000 g / mol, 10,000 g / mol to 50,000 g / mol, 10,000 g / mol to 40,000 g / mol, 10,000 g / mol to 30,000 g / mol, 20,000 g / mol to less than 75,000 g / mol, 20,000 g / mol to 70,000 g / mol, 20,000 g / mol to 60,000 g / mol, 20,000 g / mol to 50,000 g / mol, 20,000 g / mol to 40,000 g / mol, and 20,000 g / mol to 30,000 g / mol. g / mol, 30,000 g / mol to less than 75,000 g / mol, 30,000 g / mol to 70,000 g / mol, 30,000 g / mol to 60,000 g / mol, 30,000 g / mol to 50,000 g / mol, 30,000 g / mol to 40,000 g / mol, 40,000 g / mol to less than 75,000 g / mol, 40,000 g / mol to 70,000 g / mol, 40,000 g / mol to 60,000 g / mol, 40,000 g / mol to 50,000 g / mol, 50,000 g / mol to less than 75,000 g / mol, 50,000 g / mol to 70,000 g / mol or 50,000 g / mol to 60,000 g / mol g / mol M n This includes any and all subranges formed by any of these endpoints.

[0053] Low molecular weight SEBS may be included in the rubber component in an amount of about 20% to about 60% by weight, based on the total weight of the rubber component. In the aspects described herein, low molecular weight SEBS is included in amounts of about 20% to about 60% by weight, about 20% to about 55% by weight, about 20% to about 50% by weight, about 20% to about 45% by weight, about 20% to about 40% by weight, about 20% to about 35% by weight, about 20% to about 30% by weight, about 25% to about 60% by weight, about 25% to about 55% by weight, about 25% to about 50% by weight, about 25% to about 45% by weight, about 25% to about 40% by weight, about 25% to about 35% by weight, about 30% to about 60% by weight, and about 30% to about 55% by weight. The amounts of approximately 30% to approximately 50% by weight, approximately 30% to approximately 45% by weight, approximately 30% to approximately 40% by weight, approximately 30% to approximately 35% by weight, approximately 35% to approximately 60% by weight, approximately 35% to approximately 55% by weight, approximately 35% to approximately 50% by weight, approximately 35% to approximately 45% by weight, approximately 35% to approximately 40% by weight, approximately 40% to approximately 60% by weight, approximately 40% to approximately 55% by weight, approximately 40% to approximately 50% by weight, or approximately 40% to approximately 45% by weight are included in the rubber component, based on the total weight of the rubber component, including any and all subranges formed by any of these endpoints.

[0054] In any aspect described herein, the ratio of the amount of high molecular weight SEBS polymer to the amount of low molecular weight SEBS polymer is from 1.1:1 to 1.5:1. For example, the ratio of the amount of high molecular weight SEBS polymer to the amount of low molecular weight SEBS polymer may be 1.1:1 to 1.5:1, 1.1:1 to 1.4:1, 1.1:1 to 1.3:1, 1.1:1 to 1.2:1, 1.2:1 to 1.5:1, 1.2:1 to 1.4:1, 1.2:1 to 1.3:1, 1.3:1 to 1.5:1, 1.3:1 to 1.4:1, or 1.4:1 to 1.5:1, including any and all subranges formed by any of these endpoints.

[0055] Unconstrained by theory, it is believed that low molecular weight SEBS polymers induce the order-disorder transition (ODT) temperature of high molecular weight SEBS polymers. The ODT occurs at a temperature where styrene block segments become miscible with ethylene-butene blocks, and the polymer exhibits a random / disordered melt. At temperatures below the ODT but above the glass transition temperature of SEBS (e.g., around 100°C), SEBS block copolymers exhibit "melt ordering," where the styrene domains remain associated and... X The parameters are too large to be fully mixed with the ethylene-butene block. XThe parameters were first used in Florey-Hutchins polymer theory and are now widely used in various systems to describe the interactions between two components, either within the same molecule or from different molecules. It has been observed that the ODT temperature increases with increasing styrene weight percent and molecular weight of the styrene domain. Therefore, it is thought that incorporating low molecular weight SEBS polymers lowers the ODT temperature and allows for lower viscosity at low shear rates (e.g., 0.1 rad / s).

[0056] In any aspect described herein, the TPE composition may have an ODT of 240°C or less, 235°C or less, 230°C or less, 225°C or less, 220°C or less, 215°C or less, 210°C or less, 205°C or less, 200°C or less, 195°C or less, 190°C or less, 185°C or less, 180°C or less, 175°C or less, 170°C or less, 165°C or less. In any aspect described herein, the TPE composition may have an ODT of 155°C or greater, 160°C or greater, 165°C or greater, 170°C or greater, 175°C or greater, 180°C or greater, 185°C or greater, 190°C or greater, 195°C or greater, 200°C or greater, 205°C or greater, 210°C or greater, 215°C or greater, 220°C or greater, 225°C or greater, 230°C or greater, or 235°C or greater. In any aspect described herein, the TPE composition may have an ODT in the range of about 155°C to 240°C, about 160°C to 235°C, about 165°C to 230°C, about 160°C to 170°C, about 170°C to 180°C, about 180°C to 190°C, about 190°C to 200°C, about 200°C to 210°C, about 210°C to 220°C, about 220°C to 230°C, or about 230°C to 240°C, including any and all subranges formed by any of these endpoints.

[0057] preparation

[0058] In any aspect described herein, the rubber component may be formed by compounding or otherwise combining high molecular weight SEBS polymers and low molecular weight SEBS polymers to produce the rubber component. Alternatively, the high molecular weight SEBS polymer and the low molecular weight SEBS polymer may be added independently to the oil and polyolefin (hereinafter) to form a composition without first forming separate rubber components.

[0059] Polyolefins

[0060] In all the aspects provided herein, the TPE composition further includes at least one polyolefin. The polyolefin may include, for example, polypropylene (PP), or polyethylene (PE), or combinations thereof, where polypropylene (PP) includes random copolymers or homopolymers of polypropylene, and polyethylene (PE) includes high-density polyethylene (HDPE), low-density polyethylene (LDPE), or linear low-density polyethylene (LLDPE). Polyolefins (especially PP) can improve transparency, reduce stiffness and increase flexibility, and can reduce oil content while maintaining a similar modulus of the composition.

[0061] In the case of polyethylene (PE) as a polyolefin, when measured according to ASTM D1238 at 190°C and 2.16 kg, polyethylene may have a melt flow index greater than or equal to 40 g / 10 min. For example, PE can have a range of approximately 40 g / 10 min to approximately 100 g / 10 min, approximately 40 g / 10 min to approximately 90 g / 10 min, approximately 40 g / 10 min to approximately 80 g / 10 min, approximately 40 g / 10 min to approximately 70 g / 10 min, approximately 40 g / 10 min to approximately 60 g / 10 min, approximately 40 g / 10 min to approximately 50 g / 10 min, approximately 45 g / 10 min to approximately 100 g / 10 min, approximately 45 g / 10 min to approximately 90 g / 10 min, approximately 45 g / 10 min to approximately 80 g / 10 min, approximately 45 g / 10 min to approximately 70 g / 10 min, approximately 45 g / 10 min to approximately 60 g / 10 min, approximately 45 g / 10 min to approximately 50 g / 10 min, approximately 50 g / 10 min to approximately 100 g / 10 min, approximately 50 g / 10 min to approximately 90 g / 10 min. Melt flow index of about g / 10min, about 50 g / 10min to about 80 g / 10min, about 50 g / 10min to about 70 g / 10min, or about 50 g / 10min to about 60 g / 10min, including any and all subranges formed by any of these endpoints.

[0062] In the case of polypropylene as a polyolefin, polypropylene (PP) can have a melt flow index greater than or equal to 50 g / 10 min when measured at 230°C and 2.16 kg according to ASTM D1238. For example, PP can have a strength of about 50 g / 10 min to about 1200 g / 10 min, about 50 g / 10 min to about 1000 g / 10 min, about 50 g / 10 min to about 750 g / 10 min, about 50 g / 10 min to about 500 g / 10 min, about 50 g / 10 min to about 250 g / 10 min, about 50 g / 10 min to about 100 g / 10 min, about 50 g / 10 min to about 90 g / 10 min, about 50 g / 10 min to about 80 g / 10 min, about 50 g / 10 min to about 70 g / 10 min, about 50 g / 10 min to about 60 g / 10 min, about 55 g / 10 min to about 1200 g / 10 min, about 55 g / 10 min to about 1000 g / 10 min, about 55 g / 10 min to about 750 g / 10 min, about 5 ... g / 10min to about 500 g / 10min, about 55 g / 10min to about 250 g / 10min, about 55 g / 10min to about 100 g / 10min, about 55 g / 10min to about 90 g / 10min, about 55 g / 10min to about 80 g / 10min, about 55 g / 10min to about 70 g / 10min, about 55 g / 10min to about 60 g / 10min, about 60 g / 10min to about 1200 g / 10min, about 60 g / 10min to about 1000 g / 10min, about 60 g / 10min to about 750 g / 10min, about 60 g / 10min to about 500 g / 10min, about 60 g / 10min to about 250 g / 10min, about 60 g / 10min to about 100 g / 10min, about 60 g / 10min to about 90 g / 10min Melt flow index of g / 10min, about 60 g / 10min to about 80 g / 10min, or about 60 g / 10min to about 70 g / 10min, including any and all subranges formed by any of these endpoints.

[0063] Commercially available polyolefins suitable for inclusion in compositions include (by example, not as a limitation) TOTAL TM 3860X (polypropylene homopolymer with a melt flow index of 100 g / 10 min (2.16 kg; 230 °C), available from TotalEnergies), PINNACLE TMPP 6180 C3 (a random copolymer of polypropylene with a melt flow index of 80 g / 10 min (2.16 kg; 230 °C), available from Pinnacle Polymers) and METOCENE TM MF650X (polypropylene homopolymer with a melt flow index of 1200 g / 10min (2.16 kg; 230°C), available from LyondellBasell Industries).

[0064] In any aspect described herein, the polyolefin is included in the composition in an amount from about 20% to about 60% by weight. The specific amount of polyolefin included in the composition may vary depending on the melt flow index of the polyolefin, the desired hardness of the final product prepared from the composition, and the processing parameters the composition will undergo. For example, the composition may include about 20% to about 60% by weight, about 20% to about 55% by weight, about 20% to about 50% by weight, about 20% to about 45% by weight, about 20% to about 40% by weight, about 20% to about 35% by weight, about 25% to about 60% by weight, about 25% to about 55% by weight, about 25% to about 50% by weight, about 25% to about 45% by weight, about 25% to about 40% by weight, about 25% to about 35% by weight, about 30% to The amount of polyolefin, based on the total weight of the composition, includes any and all subranges formed by any of these endpoints, in amounts of about 60 wt%, about 30 wt% to about 55 wt%, about 30 wt% to about 50 wt%, about 30 wt% to about 45 wt%, about 30 wt% to about 40 wt%, about 30 wt% to about 35 wt%, about 35 wt% to about 60 wt%, about 35 wt% to about 55 wt%, about 35 wt% to about 50 wt%, about 35 wt% to about 45 wt%, or about 35 wt% to about 40 wt%, based on the total weight of the composition.

[0065] Oil

[0066] As described above, the composition also includes at least one oil. Without being theoretically limited, it is believed that the oil can contribute to graffiti, permanent marker, and ink removal properties. Therefore, in any exemplary aspect, the TPE composition can be resistant to ink / marker stains and graffiti. Furthermore, the oil can contribute to the processing temperature of the composition. Specifically, the limitation of the processing temperature of the composition can be related to the vaporization of the oil, and therefore, the selection of the oil can change the processing temperature. The oil can also be used to adjust the softness of the composition and / or improve the flowability of the composition.

[0067] In all the respects provided herein, the oil may comprise polyalphaolefin (PAO), mineral oil, or combinations thereof. In any respect, the oil may be a bio-derived oil. In all respects, the oil has a flash point greater than about 230°C, as determined according to ASTM D92. For example, the oil may have a flash point of about 230°C to about 300°C, about 230°C to about 290°C, about 230°C to about 280°C, about 230°C to about 270°C, about 230°C to about 260°C, about 230°C to about 250°C, about 235°C to about 300°C, about 235°C to about 290°C, about 235°C to about 280°C, about 235°C to about 270°C, about 235°C to about 260°C, about 235°C to about 250°C, about 240°C to about 300°C, about 240°C to about 290°C, about 240°C to about The flash point of about 280°C, about 240°C to about 270°C, about 240°C to about 260°C, about 240°C to about 250°C, about 245°C to about 300°C, about 245°C to about 290°C, about 245°C to about 280°C, about 245°C to about 270°C, about 245°C to about 260°C, about 245°C to about 250°C, about 250°C to about 300°C, about 250°C to about 290°C, about 250°C to about 280°C, about 250°C to about 270°C, or about 250°C to about 260°C, as determined according to ASTM D92, including any and all subranges formed by any of these endpoints.

[0068] Oils included in the composition in all aspects may also have relatively low kinematic viscosity (e.g., 105 cSt or less at 40°C). The kinematic viscosity of the oil is measured according to ASTM D445. In all aspects, the oil has approximately 15 cSt to approximately 105 cSt, approximately 15 cSt to approximately 100 cSt, approximately 15 cSt to approximately 95 cSt, approximately 15 cSt to approximately 90 cSt, approximately 15 cSt to approximately 85 cSt, approximately 15 cSt to approximately 80 cSt, approximately 15 cSt to approximately 75 cSt, approximately 15 cSt to approximately 70 cSt, approximately 25 cSt to approximately 105 cSt, approximately 25 cSt to approximately 100 cSt, approximately 25 cSt to approximately 95 cSt, approximately 25 cSt to approximately 90 cSt, approximately 25 cSt to approximately 85 cSt, approximately 35 cSt to approximately 105 cSt, approximately 35 cSt to approximately 100 cSt, approximately 35 cSt to approximately 95 cSt, approximately 35 cSt to approximately 90 cSt, approximately 35 cSt to approximately 85 cSt, approximately 35 cSt to approximately 85 cSt, approximately 35 cSt to approximately 95 cSt, approximately 35 cSt to approximately 90 ... kinematic viscosities of approximately 80 cSt, approximately 35 cSt, approximately 75 cSt, approximately 45 cSt, approximately 105 cSt, approximately 45 cSt, approximately 100 cSt, approximately 45 cSt, approximately 95 cSt, approximately 90 cSt, approximately 85 cSt, approximately 75 cSt, approximately 70 cSt, approximately 50 cSt, approximately 105 cSt, approximately 100 cSt, approximately 95 cSt, approximately 85 cSt, approximately 75 cSt, or approximately 70 cSt, determined according to ASTM D445 at 40°C.

[0069] Examples of commercially available oils include PURETOL, which is available from Petro-Canada. TM Those under the brand (including PURETOL) TM 380 and PURETOL TM 550), DURASYN available from Ineos Oligomers ® Those under the brand (including DURASYN) ® 170) and PURENOVA available from Novvi, LLC ®Those under the brand (including PURENOVA) ® 2609).

[0070] In any aspect described herein, oil is included in the composition in an amount greater than about 20% by weight, based on the total weight of the composition. In some aspects, oil is included in the composition in an amount from about 20% to about 50% by weight, based on the total weight of the composition. For example, the oil may be included in the composition in amounts of about 20% to about 50% by weight, about 25% to about 50% by weight, about 30% to about 50% by weight, about 35% to about 50% by weight, about 40% to about 50% by weight, about 45% to about 50% by weight, about 20% to about 45% by weight, about 25% to about 45% by weight, about 30% to about 45% by weight, about 35% to about 45% by weight, about 40% to about 45% by weight, about 20% to about 40% by weight, about 25% to about 40% by weight, about 30% to about 40% by weight, about 35% to about 40% by weight, about 20% to about 35% by weight, about 25% to about 35% by weight, or about 30% to about 35% by weight, including any and all ranges and subranges containing any of these endpoints.

[0071] In any respect, an amount of oil is added to the composition in a ratio of the amount of rubber composition to the amount of oil of about 1.3:1 to 0.7:1. For example, the ratio of the amount of rubber composition to the amount of oil may be 1.3:1 to 0.7:1, 1.3:1 to 0.8:1, 1.3:1 to 0.9:1, 1.3:1 to 1:1, 1.3:1 to 1.1:1, 1.2:1 to 0.7:1, 1.2:1 to 0.8:1, 1.2:1 to 0.9:1, 1.2:1 to 1:1, 1.2:1 to 1.1:1, 1.1:1 to 0.7:1, 1.1:1 to 0.8:1, 1.1:1 to 0.9:1, or 1.1:1 to 1:1, including any and all ranges and subranges that include any of these endpoints. In any aspect described herein, the ratio of the amount of rubber composition to the amount of oil in the composition may be about 1:1.

[0072] Properties and products

[0073] In any aspect described herein, in addition to the components described above, one or more additives may be incorporated into the composition. Additives may include (examples but not limitation) stabilizers, antioxidants, adhesion promoters, bactericides, antistatic agents, dispersants, fillers and extenders, lubricants, initiators, pigments, colorants and dyes, release agents, and any other additives known and used in the art.

[0074] While fillers may be used in some of the aspects described herein, it is advantageous to prepare compositions that do not contain fillers. Fillers (e.g., calcium carbonate) have been found to produce surfaces more susceptible to permanent marker and ink stains. In any aspect, the amount of filler added to the composition may be less than 5% by weight, less than 1% by weight, or less than 0.5% by weight. In any aspect, the composition may be filler-free. In any aspect, the composition may be calcium carbonate-free.

[0075] As described above, in various aspects, the rubber component can be formed by compounding or otherwise combining high molecular weight SEBS polymers and low molecular weight SEBS polymers to produce a rubber component, which is then mixed with oils and polyolefins to form a composition. Alternatively, the high molecular weight SEBS polymers and low molecular weight SEBS polymers can be added independently to the oils and polyolefins to form a composition without first forming separate rubber components. The rubber component, oil, and polyolefins can be mixed or blended in any suitable manner to form a composition. In any aspect, the components can be added to an extruder for mixing to form a composition.

[0076] In all aspects, when measured according to ASTM D4440 using strain amplitude equal to or less than 5%, the resulting composition exhibits less than about 150 Pa at 0.1 rad / s in the temperature range of 200-250°C. Complex viscosity of s (n Complex viscosity (n) The total flow resistance is a measure of the total flow resistance as a function of the angular frequency and is given by the quotient of the maximum stress amplitude and the maximum strain amplitude. For example, when measured according to ASTM D4440 using a strain amplitude equal to or less than 5%, the composition may have approximately 75 Pa at 0.1 rad / s in a temperature range of 200-250°C. s to approximately 150 Pa s, approximately 75 Pa s to approximately 140 Pa s, approximately 75 Pa s to approximately 130 Pa s, approximately 75 Pa s to approximately 120 Pa s, approximately 75 Pa s to approximately 110 Pa s, approximately 75 Pa s to approximately 100 Pa s, approximately 75 Pa s to approximately 95 Pa s, approximately 85 Pa s to approximately 150 Pa s, approximately 85 Pa s to approximately 140 Pa s, approximately 85 Pa s to approximately 130 Pa s, approximately 85 Pa s to approximately 120 Pa s, approximately 85 Pa s to approximately 110 Pa s, approximately 85 Pa s to approximately 100 Pa s, approximately 85 Pa s to approximately 95 Pa s, approximately 95 Pa s to approximately 150 Pa s, approximately 95 Pa s to approximately 140 Pa s, approximately 95 Pa s to approximately 130 Pa s, approximately 95 Pa s to approximately 120 Pa s, approximately 95 Pa s to approximately 110 Pa s, or approximately 95 Pa s to approximately 100 Pa The complex viscosity of s, including any and all ranges and subranges containing any of these endpoints.

[0077] In various aspects, the composition can be extruded into multiple particles, which can then be ground, milled, or otherwise processed to form small granules, microparticles, cryogenic powders, etc. In some aspects described herein, the composition can be formed into microparticles via an extrusion process. In some aspects, granules can be formed via a cryogenic milling process, wherein the extruded composition is ground into powder, immersed in a cryogenic liquid, and then milled. In some aspects, the granules can be sieved to obtain polymeric materials with an average particle size of less than about 1,000 μm, less than about 600 μm, or even less than 500 μm. In some aspects, the granules of the composition can be sieved using a 35-mesh sieve, although other sieve sizes can be used depending on the desired particle size.

[0078] Granules and / or powders can be used in extrusion or molding processes to form molded or extruded articles. Those skilled in the art of thermoplastic polymer engineering are familiar with subsequent extrusion or molding processes. Without excessive experimentation, one can refer to “Extrusion, The Definitive Processing Guide and Handbook”; “Handbook of Molded Part Shrinkage and Warpage”; “Specialized Molding Techniques”; “Rotational Molding Technology”; and “Handbook of Mold, Tool and Die Repair Welding”, all published by the Plastics Design Library (www.williamandrew.com), to manufacture articles of any conceivable shape and appearance using formulations from any aspect described herein. In any aspect described herein, granules and / or powders can be used to form rotationally molded articles.

[0079] In all aspects, a rotationally molded article formed from or including a composition of any aspect described herein may have a wall thickness of about 0.5 mm to about 50 mm. For example, a rotationally molded article may have a wall thickness of about 0.5 mm to about 50 mm, about 0.5 mm to about 45 mm, about 0.5 mm to about 40 mm, about 0.5 mm to about 35 mm, about 0.5 mm to about 30 mm, about 0.5 mm to about 25 mm, about 1 mm to about 50 mm, about 1 mm to about 45 mm, about 1 mm to about 40 mm, about 1 mm to about 35 mm, about 1 mm to about 30 mm, about 1 mm to about 25 mm, about 5 mm to about 50 mm, about 5 mm to about 45 mm, about 5 mm to about 40 mm, about 5 mm to about 35 mm, about 5 mm to about 30 mm, or about 5 mm to about 25 mm, including any and all ranges and subranges encompassing any of these endpoints.

[0080] In various aspects, the rotationally molded article includes a void therein. For example, the void may be defined by the inner surface of one or more walls of the rotationally molded article. In any aspect herein, at least a portion of the void may be filled. For example, at least a portion of the void may be filled with a foam material. Additionally or alternatively, at least a portion of the void may remain unfilled.

[0081] Rotationally molded articles in any aspect of this document may take any form, such as barrels or containers, automotive parts, traffic cones or barriers, toys, sporting equipment, commercial, agricultural, or industrial products, etc. Other articles are possible and foreseeable in other industries.

[0082] The general inventive concept has been described above in general and in relation to various specific aspects. Although the general inventive concept has been set forth in illustrative aspects which are considered exemplary, a variety of alternatives will become apparent to those skilled in the art upon reading this disclosure. The general inventive concept is not limited except for those situations presented in the specific claims.

[0083] Example

[0084] The following examples are included for illustrative purposes and do not limit the scope of the general inventive concept described herein.

[0085] The materials provided in Table 1 below will be used in the embodiments described herein.

[0086] Table 1

[0087]

[0088] In the following examples, hardness was measured according to ASTM D2240 and the values ​​were reported in Shore A scale.

[0089] Example 1

[0090] Blends using SEBS, oil, and polypropylene (25:45:30) and containing DOWLEX TM Benchmark studies were conducted on comparative compositions of 2035 (LLDPE) to evaluate the cleanability and rotational molding feasibility of the permanent marker. Injection molded specimens were formed with each material and SHARPIE was used. ® Markers and Papermeat TM Writing was done on each test piece with an ink pen. While trying to use WINDEX... TM Before cleaning, age the test pieces for 48 or 168 hours. Figure 1 As shown in the figure, in the test, the blend of SEBS, oil and polypropylene (formulation A); Figure 1 The image on the left is superior to LLDPE (formulation B); Figure 1 (Image on the right). Specifically, the test piece prepared from formulation A was tested using WINDEX. TMAfter cleaning, limited afterimages and / or residual permanent stains were observed. The presence of oil is considered the biggest contributor to the removal performance of permanent marker pens and inks. It was also found that fillers (such as calcium carbonate fillers) make the removal of permanent marker pens and inks extremely difficult.

[0091] Example 2

[0092] Next, a brief gradient study was conducted to evaluate high molecular weight SEBS (KRATON) with a styrene content of approximately 20% by weight. TM G1642HU) with and without KRATON TM Various blends were produced using G1643M, and different PP to oil ratios were explored. In this example, the target Shore A hardness of the sample was 85. It contained KRATON. TM The blends of G1643M exhibited lower viscosity. Furthermore, they also showed lower viscosity compared to samples containing higher loadings of PP and oil, similar to SEBS. However, attempts were made with blends containing KRATON... TM Rotational molding of the G1643M sample revealed significant melt agglomeration, areas rich in polypropylene, and very poor tear resistance. This suggests KRATON... TM The diblock content of G1643M prevents thorough mixing during compounding and also limits mechanical properties. KRATON-free. TM G1643M contains KRATON TM The G1642HU sample performed quite well, although noticeable pitting was observed on the component surface, such as... Figure 2A-2C As shown in the image.

[0093] Figure 2A This is an image of a complete part successfully rotary molded from formulation X. Formulation X comprises approximately 29% by weight of total. TM 3860X, approximately 33% KRATON by weight TM G1642HU and approximately 33% PURETOL by weight TM 380. Figure 2B This is an enlarged image formed by formulation X, showing surface pits. Figure 2C yes Figure 2B The negative of the image in the image provides a clearer resolution of the pits in the surface. Although Figure 2A-2C The component shown is prepared from formulation X, but is used for preparation Figure 2A The specific composition of the components in the process includes those used for preparation Figure 2B and 2C The components in the composition use different colorants.

[0094] Example 3

[0095] Without theoretical constraints, bubbles or surface pits in rotational molding are considered to be caused by trapped air / gas. Although the degree of bubble dissolution depends on the size of the gas molecules and the material chemistry, pitting can be reduced by using lower viscosity materials or applying positive pressure during molding. One way to obtain lower viscosity materials is to increase the molding temperature or shear rate of the given material. Most polymers follow exponential decay, as represented by the following Equation 1:

[0096]

[0097] Where η0 is the material viscosity, E η Where is the activation energy for viscous flow, T is the temperature, and R and K are constants. Since only low shear rates are achievable during rotational molding, further investigation was conducted into the thermal stability and, specifically, the volatility of the oil.

[0098] SEBS and PP are known to have degradation initiation temperatures greater than 300°C, and the processing temperature limits for formulations are generally related to oil vaporization. Therefore, thermogravimetric analysis (TGA) was used to compare various oils (PURETOL). TM 380 (white mineral oil), PURETOL TM 550 (white mineral oil) and DURASYN ® 170 polyalphaolefin oil (PAO) was used to determine the vaporization initiation and total volatility at 230°C during a 30-minute process. Results are as follows: Figure 3A and 3B As shown in the image.

[0099] TGA data clearly shows that the selected PAO provides reduced volatility at higher temperatures and allows for the use of higher processing temperatures. To test this concept, a mixture containing approximately 31% KRATON was used. TM G1642HU, approximately 38% TOTAL TM 3860X and approximately 31% wt% DURASYN ® The composition of 170 was used to formulate granules, which were then placed on a hot plate at different temperatures (170°C, 180°C, and 190°C) for approximately 15 minutes. Figure 3C As shown, the number of pits appearing on the surface in contact with the plate decreases with increasing temperature. Therefore, the hot plate test demonstrates the potential of the formulation to successfully eliminate air bubbles at processing temperatures ≥190°C.

[0100] Example 4

[0101] To more closely simulate the rotational molding process, SUPERDANNY was used. ®A rotary oven and paint cans are used to simulate rotary molding tools. The rotary oven rotates at 6 rpm and the oven temperature is adjustable up to 230°C. It also features a "dehydration" option, which acts as a cooling cycle with a minimum temperature of 50°C and continuous rotation. Figure 4A An image of the experimental setup is shown.

[0102] To prepare the components, various formulations were prepared as described in Table 3 below. The amounts reported in Table 3 are weight percentages (wt%) based on the total weight of the compositions. After blending, the materials prepared from each formulation were cryogenically frozen and milled using a high-speed fragrance grinder, passing through a 30-mesh sieve. Approximately 60-90 grams of powder were loaded into a 1 qt paint can and spun at a temperature between 190-230°C for 25-35 minutes, then cooled under spun conditions until the oven reached an internal temperature of 50°C.

[0103] Table 3

[0104]

[0105] Tear resistance was measured according to ASTM D624. Tensile strength was measured according to ASTM D412 (Die C). Tensile elongation was measured according to ASTM D412 (Die C). Viscosity is a complex viscosity and was measured according to ASTM D4440 at 0.1 rad / s and 200°C, using 1% of the strain amplitude, except for formulation I, which was measured at 240°C. Surface pitting refers to the visual appearance of the surface of the prepared rotationally molded article. Figure 4B and Figure 4C This is a photograph of a component molded from formulation I. For example... Figure 4B and Figure 4C As seen in the image, the parts prepared from formulation I include slight surface pits.

[0106] Early findings indicated that diblock incorporation was detrimental to mechanical properties, thus the study explored ways to lower the order-disorder transition (ODT) temperature. Specifically, it was hypothesized that incorporating SEBS with a low overall molecular weight and low polystyrene content could lower the ODT temperature and allow for lower viscosity at lower shear rates (e.g., 0.1 rad / s). Gradient studies were conducted, in which low-flow KRATON... TM G1642HU will be gradually replaced with high-flow KRATON. TM MD1648V, and ODT was measured using a temperature scan on a parallel plate rheometer. KRATON reports the formulations used for gradient studies in Table 4 below. TM The ratio of grades. Each formulation reported in Table 4 also includes 100 phr of TOTAL. TM 3860X and 100 phr PureTolTM 550 oil. Formulation N could not be granulated, therefore only formulation OR was evaluated.

[0107] Table 4

[0108]

[0109] SAOS temperature scans of formulation OR at 1% strain and 0.5 rad / s are shown in Figure 5A From the tan(δ) peak observed after the glass transition, it was found that increasing the content of high-flow SEBS could reduce the ODT from greater than 230℃ (formulation R) to about 160℃ (formulation O).

[0110] SAOS temperature scans of formulation P at various temperatures (170°C, 180°C, 190°C, and 200°C) at 1% strain are presented together with the temperature scan of formulation I at 240°C at 1% strain. Figure 5B In the middle. For example Figure 5B As shown, the practicality of ODT shift is demonstrated by formulation P achieving a low shear viscosity at 190°C comparable to that of formulation I at 240°C.

[0111] Table 4 further demonstrates that the prepared formulations essentially retain mechanical properties when a triblock copolymer of SEBS is used instead of a diblock copolymer to promote flowability. For example, the tear resistance of formulation P decreased by only about 7.5% and the tensile strength by about 5% compared to formulation R. The largest change in properties was the decrease in elongation, from 500% (formulation R) to 400% (formulation P). However, a value of less than or equal to 100 Pa at 0.1 rad / s was obtained. The viscosity of s is necessary for producing a pit-free finish.

[0112] Unless otherwise specified, the entire contents of each document referenced herein are incorporated herein by reference. Reference to any document should not be construed as an admission that it is prior art with respect to any invention disclosed or claimed herein. In the event of any conflict between the meaning or definition of any term in this document and the meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall prevail.

[0113] It is evident that modifications and variations may be made without departing from the scope of this disclosure as defined by the appended claims. More specifically, although certain aspects of this disclosure have been identified herein as preferred or particularly advantageous, it is contemplated that this disclosure is not necessarily limited to these aspects.

Claims

1. A composition comprising: The rubber component comprises: (i) High molecular weight styrene-ethylene-butene-styrene (SEBS) polymers having a number-average molecular weight of 75,000 g / mol to 300,000 g / mol; and (ii) Low molecular weight SEBS polymer having a polystyrene content of less than about 30% by weight and a number-average molecular weight of 10,000 g / mol to less than 75,000 g / mol; Polyolefins; and Oil.

2. The composition according to claim 1, wherein when measured according to ASTM D4440 using a strain amplitude equal to or less than 5%, the composition has a strength of less than 100 Pa at 0.1 rad / s in a temperature range of 200-250°C. The complex viscosity of s.

3. The composition according to claim 1 or claim 2, wherein the low molecular weight SEBS polymer is a triblock SEBS polymer.

4. The composition of claim 3, wherein the triblock SEBS polymer comprises an ethylene / butene mesoblock and one or more styrene-containing end blocks.

5. The composition according to any one of the preceding claims, wherein the polyolefin comprises polypropylene homopolymer, polypropylene random copolymer, high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and combinations thereof.

6. The composition according to any one of the preceding claims, wherein the polyolefin comprises polyethylene with a melt flow index greater than or equal to 40 g / 10 min, measured according to ASTM D1238 at 190°C and 2.16 kg.

7. The composition according to any one of claims 1-5, wherein the polyolefin comprises polypropylene with a melt flow index greater than or equal to 50 g / 10 min, measured at 230°C and 2.16 kg according to ASTM D1238.

8. The composition according to any one of the preceding claims, wherein the oil is present in an amount greater than or equal to about 20% by weight, based on the total weight of the composition.

9. The composition according to any one of the preceding claims, wherein the oil comprises polyalphaolefin (PAO) or mineral oil.

10. The composition according to any one of the preceding claims, wherein the oil comprises a bio-derived oil.

11. The composition according to any one of the preceding claims, wherein the oil has a flash point greater than about 230°C, as measured according to ASTM D92.

12. The composition according to any one of the preceding claims, wherein the oil has a kinematic viscosity of less than or equal to 105 cSt, measured at 40°C according to ASTM D445.

13. The composition according to any one of the preceding claims, wherein the high molecular weight SEBS polymer has a number-average molecular weight of 75,000 g / mol to 125,000 g / mol.

14. The composition according to any one of the preceding claims, wherein the low molecular weight SEBS polymer has a number-average molecular weight of 40,000 g / mol to 70,000 g / mol.

15. The composition according to any one of the preceding claims, wherein the low molecular weight SEBS polymer has a number-average molecular weight of 55,000 g / mol to 65,000 g / mol.

16. The composition according to any one of the preceding claims, wherein the ratio of the amount of the rubber composition to the amount of the oil is 1:

1.

17. The composition according to any one of the preceding claims, wherein the ratio of the amount of the high molecular weight SEBS polymer to the amount of the low molecular weight SEBS polymer is 1.1:1 to 1.5:

1.

18. The composition according to any one of the preceding claims, wherein the composition is formed as a plurality of particles having an average particle size of less than about 1,000 μm.

19. The composition of claim 18, wherein the composition is formed into a plurality of particles by low-temperature grinding.

20. The composition of claim 18, wherein the plurality of particles comprises a plurality of microparticles.

21. A rotationally molded article comprising the compound of any one of the preceding claims.

22. The rotationally molded article of claim 21, wherein the rotationally molded article has a wall thickness of about 0.5 mm to about 50 mm.

23. The rotary molded article according to claim 21 or claim 22, wherein the rotary molded article includes a void therein.

24. Methods of forming a product, including: Rotationally molded articles are formed by rotational molding of the composition, the composition comprising: Rubber components, comprising: (i) High molecular weight styrene-ethylene-butene-styrene (SEBS) polymers having a number-average molecular weight of 75,000 g / mol to 300,000 g / mol; and (ii) Low molecular weight SEBS polymers having a polystyrene content of less than about 30% by weight and a number-average molecular weight of 10,000 g / mol to 75,000 g / mol; Polyolefins; and Oil.

25. The method of claim 23, further comprising filling at least partially the voids in the molded article with foam.

Images