Thermoplastic articles and methods of preparation thereof

Abstract

Thermoplastic articles comprising a thermoplastic elastomer and an additive are provided. The additive comprises a crosslinked hydrogel and comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state. The thermoplastic articles have a haze of lower than 50%, measured according to ASTM D1003 using a haze meter. Methods for preparing the thermoplastic article are also provided.

Description

THERMOPLASTIC ARTICLES AND METHODS OF PREPARATION THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and all benefit of U.S. Provisional Patent Application No. 63 / 567,393, filed on March 19, 2024, the entire disclosure of which is fully incorporated herein by reference.FIELD

[0002] The present disclosure relates to thermoplastic articles having improved optical clarity, as well as methods of preparing the thermoplastic articles.BACKGROUND

[0003] A catheter is a medical device that is inserted into the body to aid in the diagnosis, treatment, and management of various urological and cardiovascular diseases. The tubing of the catheter is designed to reduce the friction and resistance during insertion, which minimizes the discomfort and pain associated with catheterization. Accordingly, catheter lubricity is essential to improve patient comfort and ensure ease during medical procedures.

[0004] Conventionally, in order to achieve the desired lubricity and other physical properties, a thermoplastic elastomer is either coated or compounded with an additive to prepare the catheter or other medical tubes. The commonly used additive includes hydrophilic polymers, such as polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, cellulosic polymers and polyethylene oxide.

[0005] However, incorporation of additives in the manufacturing processes often results in a decreased optical translucency of the prepared medical tubing due to the refractive index mismatch of the thermoplastic elastomer and the additive. Therefore, current medical tubes often suffer from inherent material cloudiness or “haze” that reduces visual transparency, and limits a clinician’s ability to directly observe internal fluid dynamics, potential obstructions, or subtle color changes that could indicate physiological conditions. As such, there is an urgentneed to develop medical tubing with improved surface properties and also enhanced optical clarity which could significantly improve diagnostic and therapeutic procedures.SUMMARY

[0006] Disclosed herein are thermoplastic articles comprising a thermoplastic elastomer and an additive comprising a crosslinked hydrogel. More particularly, the thermoplastic elastomer has a Shore A hardness of 35 to 99, and the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state. The thermoplastic articles of the present disclosure have reduced haze and improved optical clarity, making them especially useful for biomedical tubing applications.

[0007] In accordance with a first aspect of the present disclosure, a thermoplastic article is disclosed. The thermoplastic article comprises (a) a thermoplastic elastomer having a Shore A hardness of 35 to 99; and (b) an additive comprising a crosslinked hydrogel, the additive comprising a plurality of particles with a D90 particle size of less than 5 microns in a dry state. The thermoplastic article has a haze of lower than 50%, measured according to ASTM DI 003 using a haze meter.

[0008] In a second aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the thermoplastic article has a haze of from 1% to 40%, measured in accordance with ASTM DI 003 using a haze meter.

[0009] In a third aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the additive comprises a plurality of particles with a D90 particle size of from 0.01 to 3 microns in a dry state.

[0010] In a fourth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the crosslinked hydrogel comprises polyvinylpyrrolidone.

[0011] In a fifth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the additive is present in the thermoplastic article in an amount of from 0.1 wt.% to 20 wt.%.

[0012] In a sixth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the thermoplastic elastomer has a Shore D hardness of 1 to 80.

[0013] In a seventh aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the thermoplastic elastomer comprises thermoplastic polyurethane.

[0014] In accordance with an eighth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the additive further comprises a dispersing agent. The dispersing agent comprises one or more of surfactants, soaps, waxes, polymeric dispersing agents, inorganic dispersing agents, and mixtures thereof.

[0015] In a ninth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the dispersing agent is present in the thermoplastic article in an amount of from 0.01 wt.% to 10 wt.%.

[0016] In accordance with a tenth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, a film comprising the thermoplastic article is disclosed.

[0017] In an eleventh aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the film has a thickness of from 24 microns to 4 millimeters.

[0018] In accordance with a twelfth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, a tube comprising the thermoplastic article or comprising the film is disclosed.

[0019] In a thirteenth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the tube has a diameter of 3 to 20 french.

[0020] In a fourteenth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the tube comprises a single-layer wall or a multi-layer wall.

[0021] In a fifteenth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the tube is a catheter.

[0022] In accordance with a sixteenth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, a method of preparing a thermoplastic article is disclosed. The method comprises (a) providing ingredients comprising a thermoplastic elastomer and an additive; (b) compounding the ingredients to provide a thermoplastic composition; and (c) processing the thermoplastic composition to form the thermoplastic article. The thermoplastic elastomer has a Shore A hardness of 35 to 99, the additive comprises a crosslinked hydrogel, and the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state. The prepared thermoplastic article has a haze of lower than 50%, measured according to ASTM DI 003 using a haze meter.

[0023] In a seventeenth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the additive comprises a plurality of particles with a D90 particle size of from 0.01 to 3 microns in a dry state.

[0024] In accordance with an eighteenth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, a pellet comprising a thermoplastic composition is disclosed. The thermoplastic composition comprises (a) a thermoplastic elastomer having a Shore A hardness of 35 to 99; and (b) an additive dispersed in the thermoplastic elastomer, the additive comprising a crosslinked hydrogel, and the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state.

[0025] In accordance with a nineteenth aspect of the present disclosure, which may be combined with any other aspect listed herein unless specified otherwise, a method of preparing a thermoplastic article is disclosed. The method comprises (a) providing a substrate formed from a thermoplastic elastomer; and (b) coating the substrate with an additive. The thermoplastic elastomer has a Shore A hardness of 35 to 99, the additive comprises a crosslinked hydrogel, and the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state. The prepared thermoplastic article has a haze of lower than 50%, measured according to ASTM DI 003 using a haze meter.

[0026] In a twentieth aspect of the disclosure, which may be combined with any other aspect listed herein unless specified otherwise, the additive comprises a plurality of particles with a D90 particle size of from 0.01 to 3 microns in a dry state.DETAILED DESCRIPTION

[0027] Disclosed herein are thermoplastic articles formed from ingredients including a thermoplastic elastomer and an additive, wherein the additive is compounded in, or coated on, the thermoplastic elastomer, as well as methods of preparing the thermoplastic articles. The particle size of the additive is adapted to provide reduced haze, and thus enhanced optical clarity or transparency, to the thermoplastic articles. While the present disclosure describes certain embodiments of the thermoplastic articles and methods of manufacture in detail, the present disclosure is to be considered exemplary and is not intended to be limited to the disclosed embodiments.

[0028] As used herein, “D90 particle size” refers to a particle diameter at which 90% of a sample of particles is smaller. For example, a D90 particle size of 5 microns means that 90% of the particle sample has a diameter size of 5 micron or smaller. It is one of the several parameters used to describe particle size distribution, along with D50 and D10. Unlessotherwise indicated, the D90 particle size is measured by means of a laser light scattering technique, using a particle size analyzer from Malvern Instruments.

[0029] As used herein, the term “compounding” (including related terms, such as “compounded”) refers to the formation of a composition or mixture via melt mixing a neat polymer resin and at least one other ingredient including, but not limited to, one or more additives, or one or more other polymer resins, or both.

[0030] As used herein, the term “coating” (including related terms, such as “coated”) refers to the formation of a layer of material (“coating layer”) on a surface of a substrate. The coating can be conducted by a process known in the art, such as dip coating, spray coating, or it can be carried out by coextruding a substrate composition and a coating composition to give an article having a substrate and a coating layer thereon. The bonding between the coating layer and the substrate can be established by, for example, chemical reactions or physical bonding (e.g., noncovalent force).

[0031] As used herein, the term “thermoplastic” refers to a polymer that softens when exposed to heat and returns to its original condition when at room temperature.

[0032] As used herein, the term “haze” refers to the percentage of light scattered or diffused by greater than 2.5 degrees on average when passing through a transparent or semi-transparent article. The lower the haze measurement value, the higher the clarity of the article. Unless otherwise indicated, haze is measured in accordance with ASTM D1003 using a haze meter. Specifically, a specimen is place between a light source and a detector of the haze meter, and the haze meter measures the amount of total light transmitted by the specimen and the amount of light scattered by greater than 2.5 degrees relative to the incident light. The haze of the specimen is calculated by the formula: Haze (%) = (Scattered Transmittance / Total Transmittance) x 100%.

[0033] The terminology as set forth herein is for description of the embodiments only and should not be construed as limiting the disclosure as a whole. All references to singular characteristics or limitations of the present disclosure shall include the corresponding plural characteristic or limitation, and vice versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made. Unless otherwise specified, “a,” “an,” “the,” and “at least one” are used interchangeably. Furthermore, as used in the description and the appended claims, the singular forms “a,” “an,” and “the” are inclusive of their plural forms, unless the context clearly indicates otherwise.

[0034] To the extent that the term “includes” or “including” is used in the description or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use.

[0035] All combinations of method or process steps as used herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.

[0036] All ranges and parameters, including but not limited to percentages, parts, and ratios, disclosed herein are understood to encompass any and all sub-ranges assumed and subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less (e.g., 1 to 6.1, or 2.3 to 9.4), and to each integer (1, 2, 3, 4, 5, 6, 7, 8, 9, and 10) contained within the range.

[0037] The articles and methods of manufacture of the present disclosure can comprise, consist of, or consist essentially of the essential elements of the disclosure as described herein, as well as any additional or optional element described herein, or which is otherwise useful in thermoplastic compounding applications.

[0038] Thermoplastic compositions are further described in co-pending U.S. Pat. Appln. Pub. No. 2022 / 0119724 and U.S. Provisional Application No. 63 / 567,393, which are incorporated by reference herein in its entirety.Thermoplastic Elastomer(s)

[0039] A thermoplastic article formed from ingredients comprising a thermoplastic elastomer and an additive is disclosed. The additive may be compounded in, or coated on, the thermoplastic elastomer.

[0040] In general, the thermoplastic elastomer (“TPE”) may comprise any thermoplastic elastomer known for use in biomedical tubing devices, such as catheters. The thermoplastic elastomer may have a Shore A hardness according to ASTM D2240 of 35 to 99, including a Shore A hardness of 40 to 95, including a Shore A hardness of 45 to 95, including a Shore A hardness of 50 to 95, including a Shore A hardness of 60 to 90, including a Shore A hardness of 60 to 85, including a Shore A hardness of 65 to 85, including a Shore A hardness of 65 to 80, including a Shore A hardness of 65 to 75, including a Shore A hardness of 70 to 80. The thermoplastic elastomer may instead, or additionally, have a Shore D hardness of 1 to 80, including a Shore D hardness of 5 to 75, including a Shore D hardness of 20 to 75, including a Shore D hardness of 10 to 70, including a Shore D hardness of 15 to 60, including a Shore D hardness of 20 to 50, including a Shore D hardness of 25 to 50, including a Shore D hardness of 20 to 40, including a Shore D hardness of 25 to 40, including a Shore D hardness of 20 to35.

[0041] The thermoplastic elastomer may comprise, or consist of, thermoplastic polyurethane (“TPU”), polyether block amide (“PEB A”), or a combination thereof.

[0042] With reference to exemplary thermoplastic elastomers, the terms “TPU” and “thermoplastic polyurethane” are used interchangeably herein, and refer to polymers containing urethane (also known as ethyl carbamate) linkages, urea linkages, amide, or combinations thereof (e.g., in the case of poly(urethane-urea)s). Thus, the subject thermoplastic polyurethanes contain at least urethane linkages and, optionally, urea or amide linkages.

[0043] In general, the TPU may be based on aliphatic chemistries or aromatic chemistries. The term “aromatic,” as used herein, refers to TPUs derived from mononuclear aromatic hydrocarbon groups or polynuclear aromatic hydrocarbon groups. The term encompasses those TPUs derived from arylene groups, z.e., a divalent aromatic group. The term “aliphatic,” as used herein, refers to TPUs derived from saturated or unsaturated, linear, branched, or cyclic hydrocarbon groups. This term encompasses those TPUs derived from alkylene (e.g., oxyalkylene), aralkylene, and cycloalkylene (e.g., oxycycloalkylene) groups, as a non-limiting example. The term “alkylene group,” as used herein, refers to a saturated, linear or branched, divalent hydrocarbon group. In some aspects of the present disclosure, the preferred alkylene groups are oxyalkylene groups. The term “oxyalkylene group,” as used herein, refers to a saturated, linear or branched, divalent hydrocarbon group with a terminal oxygen atom. The term “aralkylene group,” as used herein, refers to a saturated, linear or branched, divalent hydrocarbon group containing at least one aromatic group. The term “cycloalkylene group,” as used herein, refers to a saturated, linear or branched, divalent hydrocarbon group containing at least one cyclic group. The term “oxycycloalkylene group,” as used herein, refers to a saturated, linear or branched, divalent hydrocarbon group containing at least one cyclic group and a terminal oxygen atom.

[0044] Non-limiting examples of commercially available TPU include grades of the PELLETHANE® brand, such as grade 2363-80AE, sold by The Lubrizol Corporation (Wickliffe, Ohio).; and grades of the ELASTOLLAN® brand, such as grade 1180A 10, sold by BASF Corporation (Florham Park, New Jersey). Other commercially available medical grades of TPU may additionally, or instead, be used.

[0045] With reference to exemplary thermoplastic elastomers, the terms “PEBA” and “polyether block amide” are used interchangeably herein, and refer to a block copolymer containing a hard segment of polyamide and a soft segment of polyether. Non-limiting examples of commercially available PEBA include grades of the PEBAX® brand, such as grades 3533 SA01 and 7233, sold by Arkema Group (Colombes, France); and grades of the VESTAMID® brand, sold by Evonik Industries AG (Essen, Germany). Other commercially available medical grades of PEBA may additionally, or instead, be used.

[0046] In addition to TPU and PEBA, other exemplary thermoplastic elastomers include, without limitation, fluoropolymers, nylon, other polyethers including polyether ether ketone (PEEK), polyurethane polyether, polyesters, polyester polyurethane, poly(styrene-butadiene- styrene) (SBS), styrene-ethylene-butylene-styrene (SEBS), poly(styrene-block-isobutylene- block-styrene) (SIBS), polyvinyl chloride (PVC), or combinations of any of the foregoing.Additive(s)

[0047] In general, the additive may comprise any additive known for use in biomedical tubing devices, such as catheters. The term “additive,” as used herein, is inclusive of one additive, or multiple additives in combination, unless otherwise specified.

[0048] The additive may comprise, or consist of, a hydrophilic water-insoluble polymer. The additive may comprise, or consist of, a crosslinked hydrogel. As used herein, the term “crosslinked hydrogel” refers to a water-insoluble polymer network that is capable of swelling up to l,000x in water, depending upon the level of crosslinking. Exemplary crosslinkedhydrogels include, without limitation, polyvinylpyrrolidone, polyolefin-polyoxyalkylene block copolymer, polyvinyl alcohol (PVOH), polysaccharides, polyethylene glycol (PEO), carboxymethyl cellulose (CMC), sodium salt CMC, amylose, amylopectin, polyacrylic acid, sodium salt of polyacrylic acid, salts of any of the foregoing, or copolymers containing two or more of the foregoing.

[0049] In some aspects, the crosslinked hydrogel may comprise polyolefin- polyoxyalkylene block copolymer, polyvinylpyrrolidone (“PVP”), or a combination thereof. In some aspects, the additive may comprise, or consist of, polyvinylpyrrolidone.

[0050] The polyvinylpyrrolidone hydrogel may include conventional and commercially available crosslinked polyvinylpyrrolidone. With reference to exemplary crosslinked polyvinylpyrrolidone, the terms “polyvinylpyrrolidone”, “PVP,” “crospovidone,” “insoluble polyvinylpyrrolidone”, “crosslinked polyvinylpyrrolidone”, and “crosslinked PVP” may be used interchangeably, unless otherwise specified herein. Non-limiting examples of commercially available crosslinked polyvinylpyrrolidone include grades of the KOLLIDON® brand, such as grades CL, CL-F, CL-SF, and CL-M sold by BASF Pharma (a division of BASF Corporation, Florham Park, New Jersey). These different grades of KOLLIDON® differ from each other at least in their particles size distributions, bulk densities, and swelling behaviors. In some aspects of the present disclosure, the crosslinked PVP is KOLLIDON® CL. Other commercially available grades of crosslinked polyvinylpyrrolidone may additionally, or instead, be used.

[0051] The polyolefin-polyoxyalkylene block copolymer may include conventional and commercially available polyolefin-polyoxyalkylene block copolymers. The polyolefin- polyoxyalkylene block copolymer may comprise a polypropylene-poly oxy ethylene block copolymer. Non-limiting examples of commercially available polyolefin-polyoxyalkylene block copolymers include grades of the PELESTAT brand, such as grade 300, sold by SanyoChemical (Kyoto, Japan). Other commercially available grades of polyolefin-polyoxyalkylene block copolymer may additionally, or instead, be used.

[0052] In general, crosslinking may be undertaken by any known means to reduce the soluble fraction in water or aqueous fluid. Exemplary crosslinking methods include, but are not limited to, UV radiation, hydrogen bonding, chemical crosslinking, exposure to heat, crosslinking through melt processing or extrusion, interpenetrating networks, covalent coupling, radical crosslinking sites, metal ionomeric crosslinking with Lewis acids, ring opening, the use of crosslinking agents such as neopentyl glycol diacrylate (NPGDA), the use of free radical photo-initiators, the use of metal chelating crosslinkers, the use of ester and amide crosslinking, imide or anhydride formation, and ketone oxime imine formation.

[0053] Optionally, the additive may further comprise one or more auxiliary additives in addition to the crosslinked hydrogel. In general, the auxiliary additive may comprise any additive known for use in biomedical tubing devices, such as catheters. Suitable auxiliary additives include commercially available plastics additives, including additives available in the reference E. W. Flick, “Plastics Additives Database,” Plastics Design Library (Elsevier 2004). The auxiliary additives may include antimicrobial agents, antioxidants, stabilizers, colorants, radiopaque agents, dispersing agent, or combinations thereof. The one or more auxiliary additives may be included in the thermoplastic composition in any amount sufficient to obtain a desired processing or performance property for the thermoplastic composition and / or the thermoplastic article.

[0054] For instance, one or more dispersing agents may be included with the additive to reduce the agglomeration and clumping of the crosslinked hydrogel. As particle size of the additive decreases, the additive becomes more difficult to handle and tends to agglomerate during processing. The inventors have surprisingly discovered that the inclusion of a dispersing agent improves the handling of the additive and prevents or slows particle agglomeration. Insome aspect, the dispersing agent may include one or more surfactants (e.g., anionic surfactants, non-ionic surfactants, cationic surfactants, amphoteric surfactants, gemini surfactants, and mixtures thereof), soaps, waxes, polymeric dispersing agents, inorganic dispersing agents, and mixtures thereof. Exemplary dispersing agents include but not limited to: triethyl citrate, sulfolane, polyols (e.g., propylene glycol, polyethylene glycol, glycerol), l-methyl-2- pyrrolidinone, bovine serum albumin, fetal bovine serum, bile acid salts, deoxyribonucleic acid, Pluronic™ F127, Triton™ X-100, polydopamine; l,2-dipalmitoylsn-glycero-3- phosphocholine, Tween 80, flavin mononucleotide sodium, polylactides; mixture of nonoxynol-9, sodium chlorate, and benzalkonium chloride with polydimethylsiloxane, and cellulose-based dispersants (e.g., cellulose, nanocrystalline cellulose, hydroxypropylcellulose).

[0055] If present, the crosslinked hydrogel may be treated with the dispersing agent (i.e., coated, blended, or otherwise associated) prior to compounding, such as before, during or after grinding, or the dispersing agent may be added directly to an extruder, injection molding apparatus, or other melt blending apparatus. In some aspects, the crosslinked hydrogel is treated with the dispersing agent and dispersing agent is also added separately during the melt blending process.

[0056] The dispersing agent may be present in the thermoplastic article according to the present invention in an amount sufficient to effectively reduce agglomeration of the crosslinked hydrogel during manufacturing while maintaining the desired properties of the prepared thermoplastic article. In some aspects, the dispersing agent may be present in an amount of up to 10 wt.%, including, up to 9.5 wt.%, up to 9 wt.%, up to 8.5 wt.%, up to 8 wt.%, up to 7.5 wt.%, up to 7 wt.%, up to 6.5 wt.%, up to 6 wt.%, up to 5.5 wt.%, or up to 5 wt.%, based on the total weight of the thermoplastic article. The dispersing agent may be present in an amount of from 0.1 wt.% to 10 wt.%, from 0.2 wt.% to 9.5 wt.%, from 0.5 wt.% to 9 wt.%, from 1 wt.%to 8.5 wt.%, from 1.5 wt.% to 8 wt.%, from 2 wt.% to 7.5 wt.%, from 2.5 wt.% to 7 wt.%, or from 3 wt.% to 6.5 wt.%, based on the total weight of the thermoplastic article.

[0057] In some aspects of the disclosure, the auxiliary additive comprises one or more synergists. The synergist may include molecules that inhibit migration and / or additives that improve lubricity performance or aid in facile processing. The synergist may comprise a lubricant. Exemplary synergists include, but are not limited to, pyrrolidones in addition to the requisite hydrogel, including alkyl pyrrolidones, such as lauryl pyrrolidone, polyvinylpyrrolidones, such as low molecular weight polyvinylpyrrolidone, linear polyvinylpyrrolidone, and the like, aloe, polysorbates, such as polysorbate 80 (including Tween 80), polyethylene glycol (PEG), polyvinyl alcohol (PVOH), butylene glycol, urea, surfactants, polyelectrolytes, osmotic pressure additives, fatty amides, polyacrylic acid, metal acid salts, carboxylic acid salts, polyester polyurethane, poly(styrene-butadiene-styrene) (SBS), styrene- ethylene-butylene-styrene (SEBS), poly(styrene-block-isobutylene-block-styrene) (SIBS), hydrocarbon polymers, other thermoplastic elastomers, potassium chloride (KC1), sodium chloride (NaCl), potassium iodide (KI), and the like, iodine, silver, barium, other heavy metals, and combinations of any of the foregoing.Additive Particle Size

[0058] In accordance with the present disclosure, the additive comprises a plurality of particles with a D90 particle size, when in the dry state, of less than 5 microns, including less than 4 microns, including less than 3.5 microns, including less than 3.2 microns, including less than 3 microns, including less than 2.8 microns, including less than 2.5 microns, including less than 2.3 microns, including less than 2 microns, including less than 1.8 microns, including less than 1.5 microns, including less than 1.3 microns, including less than 1 micron, and including less than 0.8 microns. In some aspects, the additives comprises a plurality of particles having a D90 particle size of from 0.01 to 5 microns, including from 0.05 to 4.5 microns, includingfrom 0.1 to 4 microns, including from 0.5 to 3.8 microns, including from 0.8 to 3.5 microns, including from 1 to 3.2 microns, and from 1.2 to 3 microns. As mentioned above, the particle sizes disclosed herein are measured by means of a laser light scattering technique, using a particle size analyzer from Malvern Instruments.

[0059] The inventors have surprisingly found that reducing the particle size of the additive provides reduced haze, and thus improved optical clarity to the thermoplastic articles.

[0060] Specifically, the particle size of the additive may be reduced via grinding the additive. The term “grinding” as used herein encompasses any known methods of milling (e.g., ball milling), shredding, sieving, or other processing methods to produce a smaller particle size. More specifically, the particle size of the additive may be altered via cryogenic grinding (“cryogrinding”), which is an operation performed in a cryogenic mixing and grinding vessel. In some aspects of the disclosure, the additive is subjected to up to four consecutive cryogrinding steps, including three consecutive cryogrinding steps, including two consecutive cryogrinding steps, including one cryogrinding step.Ranges of Ingredients

[0061] Table 1 shows exemplary ranges of ingredients for the thermoplastic article, in terms of weight percent (wt. %) based upon the total weight of the thermoplastic article. In any of the embodiments disclosed herein, the thermoplastic article may comprise, consist essentially of, or consist of the ingredients of Table 1. It is to be appreciated that any individual ranges from Ranges 1, 2 and 3 may be combined with any other compositional range(s) of Ranges 1, 2, and 3 in Table 1 below. For example, any of the individual ranges from Range 1 may be combined with the ranges in Ranges 2 and / or 3, etc.

[0062] All percentages, parts, and ratios as used herein are by weight of the total blend on an “dry” basis, z.e., without solvents, unless otherwise specified.Table 1Methods of Preparing Thermoplastic Articles

[0063] In one aspect, the disclosure includes a method of preparing a thermoplastic article through a compounding process. The method includes the steps of: (a) providing ingredients comprising a thermoplastic elastomer and an additive; (b) compounding the ingredients to provide a thermoplastic composition; and (c) processing the thermoplastic composition to form the thermoplastic article. The ingredients used in this method, including thermoplastic elastomer and additive, have been discussed in detail as set forth above. The step (b) may include extruding a melted mixture of thermoplastic elastomer and additive, to form a thermoplastic composition. The thermoplastic composition may be in a form of a plurality of particles or pellets. In the step (c), the processing of the thermoplastic composition may be based on the intended use of the article to form a shaped article, such as a film or a tube.

[0064] The thermoplastic composition may be made in batch or continuous operations. Mixing in a continuous process typically occurs in an extruder that is elevated to a temperature that is sufficient to melt the polymer matrix with addition of all additives at the feed-throat, or by injection or side-feeders downstream. Extruder speeds may range from 200 to 700 revolutions per minute (rpm), including from 300 rpm to 600 rpm. Typically, the output from the extruder is pelletized, e.g., ground or milled, to form minipellets, micropellets, pellets, or the like. The pelletized extruder output can then be used to form the thermoplastic article.

[0065] Generally, the subsequent thermoplastic articles of the present invention may be made by extrusion, injection molding, blow molding, rotational molding, thermoforming, calendering, and the like. General processing techniques are described in available references, for example, Dominick V. Rosato et al., Plastics Design Handbook (Springer 2013). Methods for forming thermoplastic articles from the thermoplastic composition via extrusion include adjusting various processing parameters including, but not limited to, ovality parameters, the gas flow rate, the free surface region, diameter, wall thickness, the screw speed, puller speed, the pull force, the tip and die design, process temperatures including zone temperatures, the cooling process, the manner of feeding, the use of a vacuum water tank, the use of coextrusion. Other downstream methods include, without limitation, melt processing the thermoplastic composition with drugs for use in medical tubing, sterilization of the thermoplastic compounds via gamma, UV, X-ray, or other standard practices, processing the thermoplastic composition with further additives to impart radiopacity, antimicrobial, or further lubricity to the thermoplastic article, treatments with isopropanol or other traditional solvents, or any combination of the foregoing.

[0066] In another aspect, the disclosure includes a method of preparing a thermoplastic article through a coating process. The method may include the steps of: (a) providing a substrate formed from a thermoplastic elastomer; and (b) applying a coating composition comprising an additive on the substrate. The ingredients used in this method, including thermoplastic elastomer and additive, have been discussed in detail as set forth above. In the step (a), the substrate formed from the thermoplastic elastomer may have a shape based on the intended use of the thermoplastic article, such in a shape of film or tube. In the step (b), the coating may be conducted by any coating methods known in the art, such as dip coating, spray coating, roll coating, spin coating, extrusion coating, and co-extrusion coating. The thermoplastic articlesformed by the coating method disclosed herein may have a better lubricity comparing with those formed by the compounding method.Thermoplastic Articles

[0067] The thermoplastic article of the present disclosure has reduced haze and improved optical clarity compared to otherwise identical articles comprising additives with a D90 particle size greater than 5 microns. Particularly, the thermoplastic article has a haze lower than 50%, including a haze lower than 45%, including a haze lower than 40%, including a haze lower than 35%, including a haze lower than 30%, %, including a haze lower than 25%, including a haze lower than 20%, including a haze lower than 15%, including a haze lower than 10%, measured according to ASTM DI 003. In some other aspects, the thermoplastic article has a haze from 1% to 50%, a haze from 1% to 45%, a haze from 1% to 40%, a haze from 1% to 35%, a haze from 1% to 30%, a haze from 1% to 25%, a haze from 1% to 20%, a haze from 1% to 15%, a haze from 1% to 10%, measured according to ASTM DI 003 using a haze meter.

[0068] The thermoplastic article of the present disclosure can be an article of a particular size and shape, based on its intended use.

[0069] For instance, the thermoplastic article may be a film, or a film may comprise the thermoplastic article. The film may have a thickness of 20 microns to 4 millimeters, including a thickness of 50 microns to 3 millimeters, including a thickness of 0.1 millimeters to 2 millimeters, including a thickness of 0.1 millimeters to 1 millimeter, including a thickness of 0.1 millimeters to 0.75 millimeters including a thickness of 0.1 millimeters to 0.5 millimeters, including a thickness of 0.15 millimeters to 0.5 millimeters, including a thickness of 0.17 millimeters to 0.45 millimeters, including a thickness of 0.35 millimeters to 0.45 millimeters, including a thickness of 0.17 millimeters to 0.22 millimeters.

[0070] In other aspects, the thermoplastic article may be a tube, or a tube may comprise the thermoplastic article. The tube may have a wall thickness of 20 microns to 4 millimeters,including a thickness of 50 microns to 3 millimeters, including a thickness of 0.1 millimeters to 2 millimeters, including a thickness of 0.1 millimeters to 1 millimeter, including a thickness of 0.1 millimeters to 0.75 millimeters including a thickness of 0.1 millimeters to 0.5 millimeters, including a thickness of 0.15 millimeters to 0.5 millimeters, including a thickness of 0.17 millimeters to 0.45 millimeters, including a thickness of 0.35 millimeters to 0.45 millimeters, including a thickness of 0.17 millimeters to 0.22 millimeters.

[0071] The tube may have a diameter of from 3 to 20 french, including from 5 to 20 french, including from 4 to 18 french, including from 8 to 20 french, including from 10 to 20 french, including from 6 to 16 french, including from 10 to 16 french, including from 6 to 10 french, including from 10 to 12 french, including from 14 to 16 french. The thermoplastic articles may be used as single layer medical tubing, or as an outer layer in a multilayer tube.

[0072] The tube may comprise a single-layer wall or a multi-layer wall.

[0073] In some aspects, the tube is a catheter.

[0074] Thermoplastic articles of the present disclosure are particularly useful in biomedical applications, including, but not limited to, catheters, single wall tubing, multilayer tubing, connectors, valves, trocars, and the like. Exemplary biomedical articles include, but are not limited to, external catheters, neural catheters, urinary catheters, IVs, endotracheal tubing, respiratory tubing, feeding tubes, ports, vascular catheters, nasal cannula tubing, stents, colonoscopy tubing, scope imaging tubing, guide wires, surgical delivery tubing, indwelling, intermittent, or ex vivo applications, or any portions of a medical device where altered surface energy is required.

[0075] In one aspect, the intended use of the thermoplastic article includes inserting the thermoplastic article into a human body.

[0076] In accordance with the present disclosure, it is possible to utilize the various inventive concepts in combination with one another. Additionally, any particular featurerecited as relating to a particularly disclosed aspect of the methods and systems of the present disclosure should be interpreted as available for use with all disclosed aspects of the methods and systems of the present disclosure, unless incorporation of the particular feature would be contradictory to the express terms of the disclosed aspect. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the disclosure, in its broader aspects, is not limited to the specific details presented therein, the representative apparatus, or the illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concepts.EXAMPLES

[0077] The following examples are included for the purposes of illustration, and do not limit the scope of the general inventive concepts described herein.

[0078] A study was conducted to evaluate the difference in haze (%) of injection molded thermoplastic plaques prepared from crosslinked hydrogel having different particle sizes.

[0079] The raw materials for preparing thermoplastic articles include a commercially available thermoplastic polyurethane (PELLETHANE® 2363-80AE), z.e., TPU elastomer, and a commercially available polyvinylpyrrolidone hydrogel (KOLLIDON® CL-M), i.e., PVP. The commercially available PVP has a D90 particle size of 14 microns in a dry state.

[0080] In Comparative Example 1, 100% of the TPU elastomer was used to prepare a thermoplastic plaque. No additive was added.

[0081] In Comparative Example 2, the PVP having a D90 particle size of 14 micron in a dry state was compounded into the TPU elastomer as received in an amount of 7 wt. % based upon the total weight of the thermoplastic composition.

[0082] In Example 1, the PVP was subjected to cryogrinding for 600 minutes to obtain ground PVP particles having a D90 particle size of 3 microns in a dry state. The ground PVPparticles were compounded into the TPU elastomer in an amount of 7 wt. %, based upon the total weight of the thermoplastic composition.

[0083] Each of the three thermoplastic compositions were then processed under identical conditions to form injection molded thermoplastic plaques. Specifically, each of the thermoplastic compositions were melt compounded and injection molded into a 4x4 (inch) plaque of identical thicknesses (1.6 mm) and cooled under sub-ambient temperatures.

[0084] The three thermoplastic plaque samples were then tested using a haze-gard i haze meter, provided by BYK Gardner, to measure the haze (%) according to ASTM DI 003. The haze testing results were illustrated in Table 2.

[0085] As shown in Table 2, the Comparative Example 1, which was made from a pure TPU elastomer has the lowest haze and this was expected since no additive was present. However, when untreated PVP was added to the TPU elastomer (Comparative Example 2), the haze increased to 62.5%, indicating substantial haze. Example 1, which included ground PVP particles (D90 particle size of 3 microns), demonstrated a dramatic drop in haze at 20.2%. Accordingly, Example 1 illustrates that a reduction in the particle size of the PVP provides a reduction in haze of the resultant thermoplastic plaque.Table 2

[0086] Although the present invention has been described with reference to particular means, materials and embodiments, from the foregoing description, one skilled in the art can easily ascertain the essential characteristics of the present invention and various changes and modifications can be made to adapt the various uses and characteristics without departing fromthe spirit and scope of the present invention as described above and set forth in the attached claims.

[0087] From the foregoing, it will be seen that this invention is one well-adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

[0088] It will be understood that certain features and sub-combinations are of utility and can be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims.

[0089] While specific elements and steps are discussed in connection to one another, it is understood that any element and / or steps provided herein is contemplated as being combinable with any other elements and / or steps regardless of explicit provision of the same while still being within the scope provided herein. Since many possible embodiments can be made of the disclosure without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

[0090] All documents cited herein are incorporated herein by reference in their entirety unless otherwise specified. The citation of any document is not to be construed as an admission that it is prior art with respect to the disclosed invention.

[0091] It will be apparent that modifications and variations are possible without departing from the scope of the disclosure defined in the appended claims. Although some aspects of the present disclosure are identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not necessarily limited to these aspects.

Claims

CLAIMSWhat is claimed is:

1. A thermoplastic article comprising:(a) a thermoplastic elastomer having a Shore A hardness of 35 to 99; and(b) an additive comprising a crosslinked hydrogel, wherein the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state, and wherein the thermoplastic article has a haze of lower than 50%, measured according to ASTM DI 003 using a haze meter.

2. The thermoplastic article of claim 1, wherein the thermoplastic article has a haze of from 1% to 40%, measured in accordance with ASTM DI 003 using a haze meter.

3. The thermoplastic article of claim 1 or claim 2, wherein the additive comprises a plurality of particles with a D90 particle size of from 0.01 to 3 microns in a dry state.

4. The thermoplastic article of any one of claims 1-3, wherein the crosslinked hydrogel comprises polyvinylpyrrolidone.

5. The thermoplastic article of any one of claims 1-4, wherein the additive is present in the thermoplastic article in an amount of from 0.1 wt.% to 20 wt.%.

6. The thermoplastic article of any one of claims 1-5, wherein the thermoplastic elastomer has a Shore D hardness of 1 to 80.

7. The thermoplastic article of any one of claims 1-6, wherein the thermoplastic elastomer comprises thermoplastic polyurethane.

8. The thermoplastic article of any one of claims 1-7, wherein the additive further comprises a dispersing agent, and wherein the dispersing agent comprises one or more of surfactants, soaps, waxes, polymeric dispersing agents, inorganic dispersing agents, and mixtures thereof.

9. The thermoplastic article of claim 8, wherein the dispersing agent is present in the thermoplastic article in an amount of from 0.01 wt.% to 10 wt.%.

10. A film, comprising the thermoplastic article of any one of claims 1-9.

11. The film of claim 10, wherein the film has a thickness of from 24 microns to 4 millimeters.

12. Atube, comprising the thermoplastic article of any one of claims 1-9, or comprising the film of any one of claims 10-11.

13. The tube of claim 12, wherein the tube has a diameter of 3 to 20 french.

14. The tube of claim 12 or claim 13, wherein the tube comprises a single-layer wall or a multi-layer wall.

15. The tube of any one of claims 12-14, wherein the tube is a catheter.

16. A method of preparing a thermoplastic article, the method comprising:(a) providing ingredients comprising a thermoplastic elastomer and an additive;(b) compounding the ingredients to provide a thermoplastic composition; and(c) processing the thermoplastic composition to form the thermoplastic article, wherein the thermoplastic elastomer has a Shore A hardness of 35 to 99; wherein the additive comprises a crosslinked hydrogel; wherein the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state; and wherein the thermoplastic article has a haze of lower than 50%, measured according to ASTM DI 003 using a haze meter.

17. The method of claim 16, wherein the additive comprises a plurality of particles with a D90 particle size of from 0.01 to 3 microns in a dry state.

18. The method of claim 16 or claim 17, wherein the thermoplastic article has a haze of from 1% to 40%, measured in accordance with ASTM DI 003 using a haze meter.

19. The method of any one of claims 16 to 18, wherein the crosslinked hydrogel comprises polyvinylpyrrolidone.

20. The method of any one of claims 16 to 19, wherein the additive is present in the thermoplastic article in an amount of from 0.1 wt.% to 20 wt.%.

21. The method of any one of claims 16 to 20, wherein the thermoplastic elastomer has a Shore D hardness of 1 to 80.

22. The method of any one of claims 16 to 21, wherein the thermoplastic elastomer comprises thermoplastic polyurethane.

23. The method of any one of claims 16 to 22, wherein the additive further comprises a dispersing agent, and wherein the dispersing agent comprises one or more of surfactants, soaps, waxes, polymeric dispersing agents, inorganic dispersing agents, and mixtures thereof.

24. The method of any one of claims 16 to 23, wherein the dispersing agent is present in the thermoplastic article in an amount of from 0.01 wt.% to 10 wt.%.

25. A film, comprising the thermoplastic article formed in accordance with of any one of claims 16 to 24.

26. The film of claim 25, wherein the film has a thickness of from 24 microns to 4 millimeters.

27. A pellet comprising a thermoplastic composition, the thermoplastic composition comprising:(a) a thermoplastic elastomer having a Shore A hardness of 35 to 99; and(b) an additive dispersed in the thermoplastic elastomer, the additive comprising a crosslinked hydrogel, and the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state.

28. The pellet of claim 27, wherein the pellet has a haze of from 1% to 40%, measured in accordance with ASTM DI 003 using a haze meter.

29. The pellet of claim 27 or 28, wherein the additive comprises a plurality of particles with a D90 particle size of from 0.01 to 3 microns in a dry state.

30. The pellet of any one of claims 27-29, wherein the crosslinked hydrogel comprises polyvinylpyrrolidone.

31. The pellet of any one of claims 27-30, wherein the additive is present in the pellet in an amount of from 0.1 wt.% to 20 wt.%.

32. The pellet of any one of claims 27-31, wherein the thermoplastic elastomer has a Shore D hardness of 1 to 80.

33. The pellet of any one of claims 27-32, wherein the thermoplastic elastomer comprises thermoplastic polyurethane.

34. The pellet of any one of claims 27-33, wherein the additive further comprises a dispersing agent, and wherein the dispersing agent comprises one or more of surfactants, soaps, waxes, polymeric dispersing agents, inorganic dispersing agents, and mixtures thereof.

35. A method of preparing a thermoplastic article, the method comprising:(a) providing a substrate formed from a thermoplastic elastomer; and(b) coating the substrate with an additive; wherein the thermoplastic elastomer has a Shore A hardness of 35 to 99; wherein the additive comprises a crosslinked hydrogel; wherein the additive comprises a plurality of particles with a D90 particle size of less than 5 microns in a dry state; and wherein the thermoplastic article has a haze of lower than 50%, measured according to ASTM DI 003 using a haze meter.

36. The method of claim 35, wherein the additive comprises a plurality of particles with aD90 particle size of from 0.01 to 3 microns in a dry state.

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