Rare earth catalyst-catalyzed polyisoprene products

Abstract

This disclosure provides polymer compound products containing polyisoprene catalyzed by a rare earth metal catalyst. [Solution] A polymer compound product comprising an elastomer layer, the elastomer layer comprising cured synthetic polyisoprene particles, and the cured synthetic polyisoprene particles comprising rare earth catalytic polyisoprene. The polyisoprene particles may contain sulfur crosslinks and / or be pre-vulcanized. Also disclosed herein is a method for producing a polymer compound product comprising an elastomer layer, the elastomer layer comprising cured synthetic polyisoprene particles, and the cured synthetic polyisoprene particles comprising rare earth catalytic polyisoprene.

Description

[Technical Field]

[0001] Cross-reference of related applications This application claims priority from U.S. Provisional Patent Application No. 63 / 155,959, filed on March 3, 2021, and Australian Provisional Patent Application No. 2022 / 900058, filed on January 12, 2022. The contents of each application are incorporated herein by reference in their entirety.

[0002] This disclosure relates to polymer compound products comprising polyisoprene catalyzed with rare earth metal catalysts. Specifically, personal protective devices, more specifically gloves and condoms, comprise an elastomer layer of cured, pre-vulcanized synthetic polyisoprene particles, the synthetic polyisoprene particles being made from polyisoprene catalyzed with rare earth metal catalysts. [Background technology]

[0003] Personal protective equipment and medical devices such as condoms, finger cots, contraceptive pessaries, examination and surgical gloves, catheter tubes, and catheter balloons are typically made from polymeric compound materials and provide protection against chemicals, abrasions, bacteria, viruses, and microorganisms in many applications. Polymeric compound materials include natural rubber latex (natural polyisoprene), synthetic polyisoprene, or various polyurethanes. Preventive medical devices made from natural rubber are durable. Natural rubber, sourced from rubber trees and / or guayule rubber, possesses a high level of stereoregularity. Approximately 98% by weight of the polyisoprene polymer component of natural rubber latex is cis-1,4-isoprene units, and approximately 2% by weight is trans-1,4-isoprene units. Natural rubber latex is also a highly branched polymer compound with a high molecular weight and a broad molecular weight distribution. These properties of natural rubber result in vulcanized rubber products with a unique combination of strength and elasticity. However, natural rubber also contains proteins that can cause skin allergic reactions in some sensitive individuals.

[0004] Synthetic polyisoprene resins were developed to offer the advantages of natural rubber while eliminating the potential for protein allergies. Some synthetic polyisoprenes, such as those produced by anionic addition polymerization, typically consist of low levels of stereoregularity (i.e., about 90–92% cis-1,4-isoprene) and reduced molecular weight. Other synthetic polyisoprenes, such as those produced by the Ziegler-Natta catalyst (titanium-aluminum catalyst), can offer higher molecular weight and higher cis structure (i.e., about 96–98.5% cis-1,4-isoprene), but are susceptible to crystallization, high gel content, and high ash content.

[0005] Therefore, products manufactured from such synthetic polyisoprene may still have some inferior properties compared to natural rubber products.

[0006] There is a need to manufacture products such as personal protective devices, more specifically, thin, strong, and non-allergenic personal protective devices such as condoms, finger cots, and polymer compound gloves.

[0007] The discussions of documents, actions, materials, devices, products, etc., contained herein shall not be deemed to acknowledge that any or all of these matters constitute general knowledge in the art relating to this disclosure, such as forming part of the foundation of the prior art or existing prior to the respective priority dates of the appended claims. [Overview of the project]

[0008] Disclosed herein are polymer compound products, It contains an elastomer layer, the elastomer layer contains early vulcanization-cured synthetic polyisoprene particles, the early vulcanization-cured synthetic polyisoprene particles contain multiple sulfur crosslinks and rare earth catalytic polyisoprene material, the rare earth catalytic polyisoprene material contains more than 97.0% by weight of cis-1,4 isomer components and rare earth element components of 0.1 mg / kg or more and 100 mg / kg or less. Synthetic polyisoprene particles are high-molecular-weight compound products that undergo early vulcanization.

[0009] Furthermore, the following is disclosed herein: condoms, It contains an elastomer layer, the elastomer layer contains cured synthetic polyisoprene particles, and the cured synthetic polyisoprene particles are pre-vulcanized and contain sulfur crosslinks. The synthetic polyisoprene particles contain a rare earth catalyst-catalyzed polyisoprene material, and the rare earth catalyst-catalyzed polyisoprene material is A cis-1,4 isomer component exceeding 97.0% by weight and a trans-1,4 isomer component of 1% by weight or less, This condom contains 3,4 isomer components in an amount of 1% by weight or less.

[0010] Furthermore, disclosed herein are methods for producing polymer compound products, The process involves prematurely vulcanizing an emulsion containing a rare-earth catalyst-catalyzed polyisoprene material with more than 97.0% by weight of cis-1,4 isomer components, and placing an elastomer coating of the emulsion containing the rare-earth catalyst-catalyzed polyisoprene material into a mold. This includes curing an elastomer coating to form an elastomer layer on a polymer compound product. The method involves forming an elastomer layer containing sulfur-crosslinked cured synthetic polyisoprene particles and rare earth element components in an amount of 0.1 mg / kg or more and 100 mg / kg or less.

[0011] Furthermore, the polymer compound products disclosed herein are also those manufactured by the methods described herein.

[0012] Embodiments according to the present disclosure include polymer compound products comprising synthetic polyisoprene materials catalyzed using a rare earth catalyst, and methods for producing the polymer compound products, which are disclosed, for example, substantially as shown and / or described in connection with at least one of the drawings, and as more fully set forth in the claims. Various advantages, aspects, and novel features of the present disclosure will be more fully understood from the following description and drawings.

[0013] The foregoing summary is not, and should not be expected to be, intended to describe each or every embodiment of the present disclosure. Other and further embodiments are described below.

[0014] It will be understood that embodiments of the various aspects of the present disclosure may be applied equally to other aspects mutatis mutandis. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order that the above-described features of the present disclosure may be understood in detail, a more particular description of the present disclosure, briefly summarized above, may be had by reference to embodiments, a portion of which is illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only typical embodiments of the present disclosure, and are therefore not to be considered as limiting the scope of the present disclosure, as the present disclosure may admit to other equally effective embodiments. It is to be understood that elements and features of one embodiment may be found in other embodiments without further recitation. It is further to be understood that where possible, identical reference numerals are used to indicate equivalent elements common to the drawings.

[0016] [Figure 1] It is a schematic perspective view of a condom according to one embodiment. [Figure 2] FIG. 2A is a first transmission electron microscope (TEM) image according to an embodiment of the present disclosure, and FIG. 2B is an annotated version of FIG. 2A. [Figure 3] FIG. 3 shows a second TEM image according to an embodiment of the present disclosure. [Figure 4]3 shows a third TEM image according to an embodiment of the present disclosure. [Figure 5] 4 shows a fourth TEM image according to an embodiment of the present disclosure. [Figure 6] 5 shows a fifth TEM image according to an embodiment of the present disclosure. [Figures 7A-7B] 6 shows a sixth TEM image according to an embodiment of the present disclosure, and FIG. 7B is an annotated version of FIG. 7A. DETAILED DESCRIPTION OF EMBODIMENTS

[0017] Terms and Definitions Before describing embodiments of the present disclosure in detail, terms used herein are for the sole purpose of describing particular embodiments and are not intended to be limiting. Embodiments described herein are not necessarily to be limited to any particular composition, material, design or apparatus, and as such may vary. All technical and scientific terms used herein have the ordinary meaning as conventionally understood by those skilled in the art to which the present disclosure pertains, unless otherwise defined in context.

[0018] Definitions are provided to help describe particular embodiments, and are not intended to limit the claimed invention, as the scope of the present invention is limited only by the claims.

[0019] All references cited herein, including publications, patent applications, and patents, are hereby incorporated by reference in their entireties to the same extent as if set forth herein in full, unless otherwise stated, and each is individually and specifically indicated to be incorporated by reference.

[0020] Unless otherwise required by the context, singular terms shall include plural forms, and plural terms shall include singular forms. Throughout this disclosure, unless otherwise specifically stated or required by the context, references to a single step, composition of a substance, group of steps, or group of compositions of a substance shall include one and more (i.e., one or more) of those steps, compositions of a substance, group of steps, or group of compositions of a substance. Accordingly, as used herein, the singular forms "a," "an," and "the" shall include multiple forms unless the context expressly indicates otherwise. For example, a reference to "a" includes not just one but two or more; a reference to "an" includes not just one but two or more; and a reference to "the" includes not just one but two or more.

[0021] Those skilled in the art will understand that the disclosure herein may be subject to variations and modifications other than those specifically described. It should be understood that this disclosure includes all such variations and modifications. This disclosure includes all examples, steps, features, methods, compositions, formulations, and processes, individually or collectively, as well as any and all combinations, or any two or more such steps or features.

[0022] The term "and / or," for example, "X and / or Y," is understood to mean either "X and Y" or "X or Y," and is interpreted to explicitly support both meanings or either one.

[0023] Unless otherwise indicated, terms such as “first,” “second,” etc., are used herein solely as labels and are not intended to impose any sequential, positional, or hierarchical requirements on the items they refer to. Furthermore, references to “second” items do not require or exclude the presence of lower-numbered items (e.g., “first” items) and / or higher-numbered items (e.g., “third” items).

[0024] As used herein, the phrases “at least one of” or “one or more of” when used with a list of items mean that one or more different combinations of the listed items may be used, and only one of the items in the list may be required. An item may be a specific object, thing, or category. In other words, “at least one of” means that any combination or number of items from the list may be used, and not all items in the list are required. For example, “at least one of item A, item B, and item C” could mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, “at least one of item A, item B, and item C” could mean, for example, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

[0025] For clarity, it should be understood that certain features described in this specification in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, various features described in the context of a single embodiment may also be provided individually or in any subcombination.

[0026] Throughout this specification, various aspects and components of the disclosure may be presented in range form. Range form is included for convenience and should not be interpreted as an inflexible limitation on the scope of the disclosure. Therefore, a range description should be deemed to specifically disclose all possible subranges and individual numerical values ​​within that range unless specifically indicated otherwise. For example, a range description of 1 to 5 should be deemed to have specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 5, 3 to 5, and individual and partial numbers within the enumerated range, e.g., 1, 2, 3, 4, 4.5, and 5, unless an integer is required or implied by the context. This applies regardless of the breadth of the disclosed range. Where specific values ​​are required, these are indicated in the specification.

[0027] Throughout this specification, the term “comprise,” or variations such as “comprises” or “comprising,” shall be understood to mean that it includes the elements, integers, or steps, or groups of elements, integers, or steps, described herein, but does not exclude any other elements, integers, or steps, or groups of elements, integers, or steps.

[0028] Throughout this specification, the term “consisting essentially of” is intended to include elements that do not substantially affect the properties of the claimed composition, but exclude elements that could substantially affect those properties.

[0029] In this specification, the terms “comprising,” “comprise,” and “comprises” are intended to be optionally interchangeable with the terms “consisting essentially of,” “consist essentially of,” “consists essentially of,” “consisting of,” “consist of,” and “consists of,” respectively.

[0030] In this specification, unless otherwise stated, the term “about” includes a tolerance of 10% in any number or value attached to the term.

[0031] The terms “emulsion,” “dispersion,” “latex,” and “suspension” are generally similar and refer to a system in which small particles of a substance, such as rubber particles, are mixed with a fluid solvent (such as water and / or alcohol and / or other organic fluids), but remain at least partially undissolved and dispersed by stirring (mechanical suspension) and / or molecular forces in the surrounding medium (colloidal suspension). Emulsions considered herein may further comprise typical and preferred components of rubber or elastomer formulations and compounds, such as accelerators including guanidine, thiazole, thiram, sulfenamide, thiourea, dithiocarbamate, and xanthogenic salts. Depending on the specific application, exemplary non-limiting examples of accelerators include hexamethylenetetramine (HMT), heptaldehyde-aniline condensation product (BA), diphenylguanidine (DPG), N,N'-dioltotolylguanidine (DOTG), 2-mercaptobenzothiazole (MBT), 2-2'-dithiobis(benzothiazole) (MBTS), zinc-2-mercaptobenzothiazole (ZMBT), zinc-O,O-di-N-phosphodithioate (ZBDP), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazole sulfenamide (TBBS), 2-(4-morpholinothio)-benzothiazole (MBS), N, One or more of the following may be used: N'-dicyclohexyl-2-benzothiazole sulfenamide (DCBS), ethylenethiourea (ETU), dipentamethylenethiourea (DPTU), dibutylthiourea (DBTU), tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), dipentamethylenethiuram tetrasulfide (DPTT), tetrabenzylthiuram disulfide (TBzTD), zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), zinc dibenzyldithiocarbamate (ZDBC), and / or zinc isopropylxanthogenicate (ZIX).The emulsions considered herein may further include activators, such as zinc oxide; crosslinking and curing agents, such as elemental sulfur, monosulfide donors, disulfide donors, such as tetramethylthiuram disulfide and tetraethylthiuram disulfide; and / or polysulfide donors, such as xanthogene polysulfides and dipentamethylenethiuram tetrasulfide. The emulsions considered herein may further include antioxidants and / or anti-ozone agents. Phenolic antioxidants may be used. At least one preferred antioxidant is the butylation reaction product of p-cresol and dicyclopentadiene (Wingstay L®). The emulsions considered herein may further include surfactants, such as sodium dodecyl sulfate and polyvinyl alcohol. The emulsions considered herein may further include rheological modifiers known to those skilled in the art, such as various clays and aluminosilicates, pH adjusters, such as hydroxides such as potassium hydroxide, pigments, processing agents, and / or fillers.

[0032] The term "polymer" generally includes, but is not limited to, homopolymers, copolymers, such as block, graft, random, and alternating copolymers, and ternary polymers. Furthermore, unless specifically limited, the term "polymer" includes all possible geometric configurations of molecules. These configurations include, but are not limited to, isotactic, syndiotactic, and random symmetries.

[0033] The term "thermoplastic" generally includes polymeric compound materials that become reversibly flexible, moldable, heatable, and solidify upon cooling above a certain temperature. The term "thermosetting" generally includes polymeric compound materials that strengthen after heating and solidification and cannot be reheated or reshaped after initial formation. The term "thermoplastic elastomer" (TPE) refers to a classification of copolymers that contain both thermoplastic and thermosetting parts, producing materials that possess the properties of both parts. The term "rubber" generally refers to elastomers produced from natural rubber latex or synthetic elastomers.

[0034] Polyisoprene products The embodiments described herein, which are briefly summarized above and described in more detail below, include products, such as personal protective equipment, such as gloves, condoms, and polymer compound products such as thin-walled condoms. Some embodiments may include gloves or condoms formed without the use of a coagulant. Other embodiments may include gloves or condoms formed with a coagulant. Embodiments may include gloves made using rare-earth catalytically synthesized polyisoprene material. Embodiments may include condoms formed using rare-earth catalytically synthesized polyisoprene material. Embodiments may include condoms made using rare-earth catalytically synthesized polyisoprene material and without the use of a coagulant. When used, the coagulant system may be formulated with one or more salts, such as, but not limited to, calcium nitrate, calcium chloride, calcium citrate, and / or aluminum sulfate. These salts may be present in amounts ranging from about 5% to about 40%, for example, from about 5% to about 25%, and / or in amounts equal to, approximately equal to, or at least equal to, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or 40%. The coagulant system may include one or more anti-tack agents, such as calcium carbonate, silica, and / or calcium stearate. The one or more anti-tack agents may be present in amounts ranging from about 1% to about 10%, for example, in amounts equal to, approximately equal to, or at least equal to, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. The coagulant system may also include one or more surfactants or wetting agents, such as one or more surfactants containing ethoxylate and / or sulfonate groups. One or more surfactants and / or wetting agents may be present in an amount ranging from about 0.05% to about 2.0%, for example, the same amount as, approximately the same amount as, or at least approximately the same amount as, 0.05%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, or 2.0%. The coagulant system may also contain one or more defoaming agents, which may be present in an amount ranging from about 0.01% to about 0.1%, for example, the same amount as, approximately the same amount as, or at least approximately the same amount as, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%.The coagulant system may contain water.

[0035] Products described herein, such as condoms, may be tested to identify and / or quantify specific properties using one or more known standards in the art, such as ISO 23409:2011, ISO 4074:2015, ASTM D3492-16, SS EN ISO 17294-1:2004, ISO 17294-2:2016, and / or US EPA Method 200.8 Revision 5.4, 1994.

[0036] Products described herein may be analyzed to evaluate and / or quantify one or more properties, such as burst pressure, burst volume, breaking force, tensile strength, and / or elongation at break.

[0037] In one embodiment, the burst pressure of the product as defined herein may be in the range of about 1.0 kPa to about 1.5 kPa, measured, for example, according to one or more of ISO 23409:2011, ISO 4074:2015, and / or ASTM D3492-16. In another embodiment, the burst pressure of the product may be 0.80, 0.85, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, or 1.50 kPa, or approximately so, at least so, or at least approximately so.

[0038] In one embodiment, the burst volume of the product as defined herein may be, approximately, at least, or at least 27.5 L, 30.0 L, 32.5 L, 35.0 L, 37.5 L, 40.0 L, 42.5 L, 45.0 L, 47.5 L, 50.0 L, 52.5 L, 55.0 L, 57.5 L, or 60.0 L. The burst volume may be measured according to one or more of ISO 23409:2011, ISO 4074:2015, and / or ASTM D3492-16.

[0039] In one embodiment, the breaking force of the product as defined herein may be the same as, approximately the same as, at least the same as, or at least the same as, 40N, 45N, 50N, 55N, 60N, 65N, 70N, 75N, 80N, 85N, 90N, 95N, 100N, 105N, 110N, or 115N. The breaking force may be measured according to one or more of ISO 23409:2011, ISO 4074:2015, and / or ASTM D3492-16.

[0040] In one embodiment, the tensile strength of the product as defined herein may be equal to, approximately equal to, at least equal to, or approximately equal to 10kPa, 11kPa, 12kPa, 13kPa, 14kPa, 15kPa, 16kPa, 17kPa, 18kPa, 19kPa, 20kPa, 21kPa, 22kPa, 23kPa, 24kPa, 25kPa, 26kPa, 27kPa, 28kPa, 29kPa, 30kPa, 31kPa, 32kPa, 33kPa, 34kPa, or 35kPa. The tensile strength may be measured according to one or more of ISO23409:2011, ISO4074:2015, and / or ASTM D3492-16.

[0041] In one embodiment, the elongation at break of a product as defined herein may be equal to, approximately equal to, at least equal to, or approximately equal to 700%, 725%, 750%, 775%, 800%, 825%, 850%, 875%, 900%, 925%, 950%, 975%, 1000%, 1025%, 1050%, 1075%, or 1100%. The elongation at break may be measured according to one or more of ISO 23409:2011, ISO 4074:2015, and / or ASTM D3492-16.

[0042] In one or more embodiments, the polymer compound product comprises cured synthetic polyisoprene particles, the cured synthetic polyisoprene particles comprises a rare-earth catalytic polyisoprene material, and the cured synthetic polyisoprene particles are crosslinked with sulfur. In one or more embodiments, the polymer compound product comprises rare-earth catalytic polyisoprene particles, and the rare-earth catalytic polyisoprene particles comprises intra-sulfur crosslinking within the polyisoprene particles, inter-sulfur crosslinking between polyisoprene particles, or both intra-sulfur crosslinking within the polyisoprene particles and inter-sulfur crosslinking between polyisoprene particles. In one or more embodiments, the cured synthetic rare-earth catalytic polyisoprene particles of the polymer compound product of the present invention comprise both intra-sulfur crosslinking within the polyisoprene particles and inter-sulfur crosslinking between polyisoprene particles. In one or more embodiments, the synthetic polyisoprene particles are bonded to each other by inter-sulfur crosslinking between polyisoprene particles. In one or more embodiments, the intra-sulfur crosslinking within the polyisoprene particles and inter-sulfur crosslinking between polyisoprene particles are uniform in the polymer compound product.

[0043] In one or more embodiments, approximately 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the polyisoprene particles used to form a product (e.g., gloves and / or condoms), for example, approximately 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%, of which at least it, approximately at least it, is pre-vulcanized, for example, pre-vulcanized to introduce inter-polyisoprene particle crosslinks, such as sulfur crosslinks. The "%" can be a fraction representing a number, w / w%, or w / v%.

[0044] In one or more embodiments, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, or less than 5% of the polyisoprene particles used to form a product (e.g., gloves and / or condoms), such as rare-earth catalyzed polyisoprene particles, are not pre-vulcanized and are subjected to, for example, intra-polyisoprene particle crosslinking, such as sulfur crosslinking. The "%" may be a fraction representing a number, w / w%, or w / v%.

[0045] In one or more embodiments, sulfur crosslinks, for example, intra- and / or inter-polyisoprene particle crosslinks, may include monosulfide bonds, disulfide bonds, or polysulfide crosslinks. In this specification, a polysulfide crosslink contains at least three sulfur atoms. In another embodiment, approximately 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of intra- and / or inter-polyisoprene particle crosslinks, or at least 95%, may include monosulfide bonds, disulfide bonds, or polysulfide crosslinks.

[0046] In one or more embodiments, a polymer compound product (e.g., gloves or condoms) comprises a post-vulcanization composition comprising pre-vulcanized synthetic polyisoprene particles, the pre-vulcanized synthetic polyisoprene particles present in amounts of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the polyisoprene particles, approximately that amount, at least that amount, or approximately at least that amount. The "%" can be a fraction representing a number, w / w%, or w / v%.

[0047] Conventional condoms made from anionic polyisoprene rubber have the advantage of being colorless and free of residual monomers (100% conversion), but a disadvantage is the low content of 90-92% by weight of cis-1,4-structured components. Furthermore, conventional condoms made from polyisoprene by the Ziegler-Natta process may have the disadvantage of being susceptible to one or more of the following: crystallization, high gel content, and / or high ash content.

[0048] Polymeric compound products, including gloves and condoms disclosed herein, made from rare earth polyisoprene rubber, may offer the advantages of a simple polymerization process, stable gel formation quality, low ash and / or gel component, and / or 97% or more of cis 1,4 components, including 97.5% or more, 98% or more, 98.5% or more, 99% or more, and 99.5% or more by weight. Here, the gel weight % may be less than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and 0.5% by weight. In one embodiment, the gel weight % may be negligible or essentially zero. Here, the ash weight % may be less than about 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.4, 0.3, 0.2, 0.1, and 0.05% by weight. In one embodiment, the ash weight % may be negligible or essentially zero.

[0049] The polyisoprene rubber used herein may have a viscosity of less than about 150 cps, for example, in the formation of one or more products described herein, in a range of about 90 to about 120 cps. In one embodiment, the polyisoprene rubber used herein, for example in the form of a resin, has a viscosity of 150 cps, 145 cps, 140 cps, 135 cps, 130 cps, 125 cps, 120 cps, 115 cps, 110 cps, 105 cps, 100 cps, 95 cps, 90 cps, 85 cps, 80 cps, 75 cps, 70 cps, 65 cps, 60 cps, 55 cps, or less than or approximately less than 50 cps.

[0050] The polyisoprene rubber used herein may contain a residual solvent, for example, one or more organic solvents used in the formation of the polyisoprene rubber. In one embodiment, the isoprene rubber contains one or more solvents in a concentration of 1500 ppm, 1250 ppm, 1000 ppm, 750 ppm, 500 ppm, 250 ppm, 100 ppm, or less than or approximately less than 50 ppm.

[0051] In one embodiment, the rare earth polyisoprene rubber may have cis 1, 4 components in amounts of 97.0%, 97.1%, 97.2%, 97.3%, 97.4%, 97.5%, 97.6%, 97.7%, 97.8%, 97.9%, 98.0%, 98.1%, 98.2%, 98.3%, 98.4%, 98.5%, 98.6%, 98.7%, 98.8%, 98.9%, 99.0%, 99.1%, 99.2%, 99.3%, 99.4%, or 99.5%, which are the same as, nearly the same as, at least the same as, or nearly at least the same as.

[0052] The inventors have unexpectedly observed that polymeric compound products, such as condoms, made from the rare-earth catalyzed polyisoprene resins described herein can have enhanced properties. For example, at higher cis components (greater than 97%, and specifically greater than 99% in some embodiments), rare-earth catalyzed polyisoprene resins have higher crosslinking availability and superior physical properties than polyisoprene resins with lower cis components (e.g., anionic polymerization and Ziegler-Natta polymerization). Any, all, or some embodiments of the present disclosure include, for example, condoms having a cross-sectional thickness of 0.050 to 0.075 mm. Alternatively, the cross-sectional thickness may be in the range of about 0.030 to about 0.075 mm, for example, about 0.030 to about 0.065 mm, about 0.050 to about 0.065 mm, or about 0.060 to about 0.075 mm. The cross-sectional thickness may be less than approximately 0.075 mm, or may be the same as, approximately the same as, at least the same as, or approximately at least the same as, 0.050, 0.055, 0.060, 0.060, 0.065, or 0.070 mm. In another embodiment, the cross-sectional thickness is less than or approximately less than 0.075, 0.070, 0.065, 0.060, 0.055, 0.050, 0.045, 0.040, 0.035, or 0.030 mm. In yet another embodiment, the average cross-sectional thickness is approximately less than or approximately less than 0.075, 0.070, 0.065, 0.060, 0.055, 0.050, 0.045, 0.040, 0.035, or 0.030 mm.

[0053] Rare earth catalysts include catalysts containing one or more rare earth metals, including scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). Neodymium-based catalysts are preferably used in one or more embodiments. Exemplary rare earth catalysts include, but are not limited to, lanthanum trichloride (LaCl3) and neodymium trichloride (NdCl3). The catalyst may be an Ln(AlMe4)3 catalyst, where Ln may be, for example, La, Ce, Pr, Nd, Gd, or Y. The residual rare earth components in the polymer compound products according to one or more embodiments are in the range of 0.1 mg / kg or more and 100 mg / kg or less, encompassing all values ​​and subranges within that range.

[0054] In one embodiment, the residual rare earth component in the polymer compound product is the same as, approximately the same as, less than, or approximately less than 100 mg / kg, 90 mg / kg, 80 mg / kg, 70 mg / kg, 60 mg / kg, 50 mg / kg, 40 mg / kg, 30 mg / kg, 20 mg / kg, 10 mg / kg, 5 mg / kg, 2 mg / kg, 1 mg / kg, 0.5 mg / kg, 0.4 mg / kg, 0.3 mg / kg, 0.2 mg / kg, or 0.1 mg / kg. In another embodiment, the residual rare earth component in the polymer compound product is the same as, approximately the same as, greater than, or approximately greater than 0.1 mg / kg, 0.2 mg / kg, 0.3 mg / kg, 0.4 mg / kg, 0.5 mg / kg, 1 mg / kg, 2 mg / kg, 5 mg / kg, 10 mg / kg, 20 mg / kg, 30 mg / kg, 40 mg / kg, 50 mg / kg, 60 mg / kg, 70 mg / kg, 80 mg / kg, 90 mg / kg, or 100 mg / kg. In yet another embodiment, the residual rare earth component in the polymer compound product is within any of these enumerated ranges.

[0055] Embodiments of the present disclosure further include condoms. Embodiments further include condoms formed without the use of a coagulant. Embodiments include condoms comprising an open end, a closed end, and a tubular sheath extending from the closed end to the open end. Figure 1 is a schematic perspective view of a condom according to one embodiment. The rare-earth catalytic polyisoprene (PI) condom 100 disclosed herein comprises a closed end 104 and an open end 108. A tubular shaft 106 extends from the closed end 104 to the open end 108, the open end 108 having an opening 110 opposite the nipple end 102 of the closed end 104. Optionally, the condom further includes beads 114. The tubular shaft of the condom comprises rare-earth catalytic PI particles, which may be provided by an aqueous rare-earth catalytic PI latex composition. The aqueous latex composition is in the range of about 55% to about 68% by weight, or about 55% to about 60% by weight, for example, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, or 68% by weight, or nearly so, at least so, or nearly at least so. The composition may further contain additional water, preferably deionized water, to yield a composition solid component in the range of 50% to 55% by weight. Optionally, the aqueous latex composition may further contain one or more thickeners (e.g., cellulose such as hydroxyethylcellulose) and / or stabilizers / surfactants. In another embodiment, one or more thermosensitive agents may be used. Colorants and / or pigments may be optionally added to the aqueous latex composition.

[0056] method Disclosed herein is a method for producing a synthetic polyisoprene product, the method comprising using an emulsion of synthetic polyisoprene resin catalyzed with a rare earth catalyst. Generally, the synthetic polyisoprene particles of a rare earth-catalyzed polyisoprene material contain 97.0% by weight or more of cis-1,4-polyisoprene.

[0057] Synthetic polyisoprene particles may include median particle diameters in the range of approximately 0.2 to 2 micrometers. Preferably, it is about 0.7 micrometers. In one embodiment, synthetic polyisoprene particles include median particle diameters that are the same as, approximately the same as, at least the same as, or at least approximately the same as, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 micrometers. In one or more embodiments, synthetic polyisoprene particles include a maximum median particle diameter of about 1 micrometer, or 1 micrometer. In another embodiment, the synthetic polyisoprene particles include maximum median particle diameters that are the same as, or approximately the same as, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 micrometers.

[0058] In this specification, the method may further include a pre-vulcanization composition and a post-vulcanization composition, along with conventional emulsion additives such as stabilizers, pH control agents, antioxidants, and preservatives. Typically, the synthetic polyisoprene latex composition is provided on a basis of 100 parts by weight of dry rubber (PHR). In the compound, the components of the latex composition may be suspended in water.

[0059] Rare earth catalyzed synthetic polyisoprene materials, such as resins, may have a pH in the range of about 9.0 to about 12.0. In one embodiment, the pH is the same as, approximately the same as, at least the same as, or at least the same as, 9.0, 9.1, 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.9, 10.0, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9, 11.0, 11.1, 11.2, 11.3, 11.4, 11.5, 11.6, 11.7, 11.8, 11.9, 12.0, 12.1, 12.2, 12.3, 12.4, or 12.5. In another embodiment, the pH is equal to, approximately equal to, less than, or approximately equal to 12.5, 12.4, 12.3, 12.2, 12.1, 12.0, 11.9, 11.8, 11.7, 11.6, 11.5, 11.4, 11.3, 11.2, 11.1, 11.0, 10.9, 10.8, 10.7, 10.6, 10.5, 10.4, 10.3, 10.2, 10.1, 10.0, 9.9, 9.8, 9.7, 9.6, 9.5, 9.4, 9.3, 9.2, 9.1, or 9.0. In yet another embodiment, the pH is within any of the ranges listed above.

[0060] In one embodiment, a pH adjuster, such as ammonium hydroxide and / or potassium hydroxide, may be used / present. In another embodiment, no pH adjuster is used / absent. In yet another embodiment, one or more pH adjusters may be present in an amount greater than 0 but less than or equal to about 5 PHR, for example, greater than 0 but equal to or equal to 0.25 PHR, 0.50 PHR, 0.75 PHR, 1.00 PHR, 1.25 PHR, 1.50 PHR, 1.75 PHR, 2.00 PHR, 2.25 PHR, 2.50 PHR, 2.75 PHR, 3.00 PHR, 3.25 PHR, 3.50 PHR, 3.75 PHR, 4.00 PHR, 4.25 PHR, 4.50 PHR, 4.75 PHR, or 5.00 PHR. In yet another embodiment, the pH adjuster is present in a range between any of these enumerated values.

[0061] Generally, early vulcanization compositions may contain sulfur in the range of 0.6 to 1.8 PHR, for example, about 0.6 to about 1.2 PHR. In one embodiment, sulfur may be present in the early vulcanization composition in amounts equal to, approximately equal to, at least equal to, or at least approximately equal to, 0.6 PHR, 0.7 PHR, 0.8 PHR, 0.9 PHR, 1.0 PHR, 1.1 PHR, 1.2 PHR, 1.3 PHR, 1.4 PHR, 1.5 PHR, 1.6 PHR, 1.7 PHR, or 1.8 PHR. In another embodiment, sulfur may be present in the early vulcanization composition in amounts equal to, approximately equal to, at least equal to, or at least approximately equal to, 1.8 PHR, 1.7 PHR, 1.6 PHR, 1.5 PHR, 1.4 PHR, 1.3 PHR, 1.2 PHR, 1.1 PHR, 1.0 PHR, 0.9 PHR, 0.8 PHR, 0.7 PHR, or 0.6 PHR. In yet another embodiment, sulfur may be present in the early vulcanization composition in amounts within any range of these enumerated values.

[0062] Here, the accelerator package may include zinc diethyldithiocarbamate (ZDEC) and / or zinc dibutyldithiocarbamate (ZDBC) accelerators and / or sodium dibutyldithiocarbamate (SDBC) accelerators, diisopropyl xanthogene polysulfide (DIXP) accelerators and / or dipentamethylenethuram tetrasulfide (DPTT) accelerators. The early vulcanization composition may include having a total accelerator component concentration in the range of 0.6 to 2.5 PHR. One or more accelerators may be present. In one embodiment, the total amount of accelerator components in the early vulcanization composition is the same as, approximately the same as, at least the same as, or at least approximately the same as, 0.6 PHR, 0.7 PHR, 0.8 PHR, 0.9 PHR, 1.0 PHR, 1.1 PHR, 1.2 PHR, 1.3 PHR, 1.4 PHR, 1.5 PHR, 1.6 PHR, 1.7 PHR, 1.8 PHR, 1.9 PHR, 2.0 PHR, 2.1 PHR, 2.2 PHR, 2.3 PHR, 2.4 PHR, or 2.5 PHR. In another embodiment, the total amount of accelerator components in the early vulcanization composition is the same as, approximately the same as, at least, or at least approximately the same as, 2.5 PHR, 2.4 PHR, 2.3 PHR, 2.2 PHR, 2.1 PHR, 2.0 PHR, 1.9 PHR, 1.8 PHR, 1.7 PHR, 1.6 PHR, 1.5 PHR, 1.4 PHR, 1.3 PHR, 1.2 PHR, 1.1 PHR, 1.0 PHR, 0.9 PHR, 0.8 PHR, 0.7 PHR, or 0.6 PHR. In yet another embodiment, the total amount of accelerator components in the early vulcanization composition is in an amount within the range of any of these enumerated values.

[0063] The early vulcanization composition may contain a zinc oxide activator.

[0064] The early vulcanization composition may contain one or more antioxidants and / or anti-ozone agents. For example, one or more antioxidants and / or anti-ozone agents in the range of about 0.1 to 1.5 PHR, e.g., the same as, approximately the same as, at least the same as, or at least approximately the same as, 0.1 PHR, 0.2 PHR, 0.3 PHR, 0.4 PHR, 0.5 PHR, 0.6 PHR, 0.7 PHR, 0.8 PHR, 0.9 PHR, 1 PHR, 1.1 PHR, 1.2 PHR, 1.3 PHR, 1.4 PHR, or 1.5 PHR.

[0065] The early vulcanization composition may contain a surfactant. The surfactant may contain one or more anionic surfactants (e.g., carboxylates, sulfonates, and / or sulfates) and / or nonionic surfactants. The surfactant may be a salt of a fatty acid such as sodium stearate, sodium oleate, or potassium caprylate. Some embodiments include two or more surfactants, for example, potassium caprylate, also known as the potassium salt of octanoic acid, and sodium dodecylbenzenesulfonate (SDBS). An exemplary embodiment includes a surfactant package having potassium caprylate, sodium dodecylbenzenesulfonate (SDBS), and polyoxyethylene cetyl / stearyl ether in the range of 0.3 to approximately 1.5 PHR. The antioxidant and preservative package includes p-cresol in the range of 0.3 to approximately 1.0 PHR and, optionally, a butylated reaction product of dicyclopentadiene. One or more surfactants may be present. In one embodiment, one or more surfactants are present in an amount ranging from about 0.3 PHR to about 3.0 PHR, for example, from about 0.8 PHR to about 1.0 PHR. In one embodiment, the total surfactant components in the early vulcanization composition are in an amount equal to, approximately equal to, at least equal to, or at least approximately equal to, 0.3 PHR, 0.4 PHR, 0.5 PHR, 0.6 PHR, 0.7 PHR, 0.8 PHR, 0.9 PHR, 1.0 PHR, 1.1 PHR, 1.2 PHR, 1.3 PHR, 1.4 PHR, 1.5 PHR, 1.6 PHR, 1.7 PHR, 1.8 PHR, 1.9 PHR, 2.0 PHR, 2.1 PHR, 2.2 PHR, 2.3 PHR, 2.4 PHR, 2.5 PHR, 2.6 PHR, 2.7 PHR, 2.8 PHR, 2.9 PHR, or 3.0 PHR.In another embodiment, the total surfactant component in the early vulcanization composition is in an amount equal to, approximately equal to, less than, or approximately less than 3.0 PHR, 2.9 PHR, 2.8 PHR, 2.7 PHR, 2.6 PHR, 2.5 PHR, 2.4 PHR, 2.3 PHR, 2.2 PHR, 2.1 PHR, 2.0 PHR, 1.9 PHR, 1.8 PHR, 1.7 PHR, 1.6 PHR, 1.5 PHR, 1.4 PHR, 1.3 PHR, 1.2 PHR, 1.1 PHR, 1.0 PHR, 0.9 PHR, 0.8 PHR, 0.7 PHR, 0.6 PHR, 0.5 PHR, 0.4 PHR, or 0.3 PHR. In yet another embodiment, the total surfactant component in the early vulcanization composition is in an amount within the range of any of these enumerated values.

[0066] The sulfur in the pre-vulcanization package is, for example, elemental sulfur with a high soluble sulfur component, usually of the S8 ring structure. The pre-vulcanization composition further contains accelerators. For example, zinc dithiocarbamate is an accelerator that can break down or destroy the S8 sulfur ring structure. The expression "high soluble sulfur component" means that there is a sufficient amount of soluble sulfur to penetrate the latex particles in the aqueous latex emulsion and crosslink during curing to form commercially acceptable products such as condoms and / or gloves. Pre-vulcanization of synthetic latex particles in latex is carried out over a period of time at a given temperature until the desired degree of pre-vulcanization is achieved. The degree of pre-vulcanization at different points after the initial compounding of synthetic latex particles can be monitored by at least one of four tests. An equilibrium swelling test using any suitable solvent measures the equilibrium swelling of a dried film from the synthetic latex. A relaxation modulus test measures the vulcanization of the relaxation modulus at 100% elongation (MR100) of a dried film from the dissolved latex. Similarly, the pre-vulcanization relaxation modulus (PRM) test measures the relaxation modulus of a pre-vulcanized film at 100% elongation.

[0067] The level of crosslinking can be measured using the toluene swelling index (TSI) test by immersing a dried molded film sample in toluene and calculating the swelling rate. A composite latex film is molded to produce a film thickness of 0.10–0.15 mm, the film is dried at 50 ± 3°C for 10 minutes and / or left at ambient temperature until the film is completely dry. The film is peeled off with a powder such as cornstarch or calcium carbonate (CaCO3) to prevent the film surface from sticking. A disc-shaped sample is cut with a die cutter. The disc-shaped film is immersed in toluene for 60 minutes. The diameter of the swollen film is measured. The swelling percentage is calculated by subtracting the diameter of the original disc from the diameter of the swollen film and dividing by the diameter of the original film. As early vulcanized sulfur is incorporated into the latex particles, they progress from a non-crosslinked stage (index greater than 220%) to a partially crosslinked stage (index less than 220%), then to a semi-crosslinked stage (index less than 180%), and finally to a fully crosslinked stage (index less than 100%).

[0068] The compounding method according to embodiments of this disclosure includes mixing latex with a chemical additive, stirring periodically, and examining the penetration of the pre-vulcanizing agent into the synthetic polyisoprene particles, for example, using an isopropanol index test. Polyisoprene latex has an inherent tendency to aggregate and "quench" through peripheral reactions with sulfur catalyzed by ZDBC or ZDEC, i.e., by hardening the outer surface and preventing crosslinking of internal molecules. Due to the presence of a surfactant and the formation of open S8 chains of sulfur, sulfur diffuses into the particles. In other words, diffusion of sulfur into the particles, i.e., "uncentric quenching," can occur, allowing crosslinking of internal molecules. Latex products or products containing an uncentric quenched structure are stronger than similar latex products or products having other quenched structures.

[0069] The residual sulfur concentration can be measured by processes known in the art, for example, by the test method UPB / P / 004 by the Malaysian Rubber Institute. The residual sulfur may be in the range of about 0.8 to about 1.5%. For example, the residual sulfur may be present in amounts of 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, or 1.5%, approximately that amount, at least that amount, or at least approximately that amount.

[0070] The TSI can be substituted by the isopropanol index test, which indicates that as premature vulcanization sulfur is incorporated into the particles, the latex particles become less sticky (index approximately 1.0) to less sticky (index 3). In one or more embodiments, a TSI of 3 indicates that premature vulcanization is acceptable.

[0071] The pre-vulcanization composition provides sulfur to synthetic polyisoprene latex particles in an aqueous synthetic polyisoprene emulsion for pre-vulcanization of the intraparticle regions. During pre-vulcanization, the sulfur ring structure is broken down by the catalytic action of an accelerator, such as zinc dithiocarbamate, which penetrates the polyisoprene particles and first interacts with the isoprene double bonds within them.

[0072] While not intended to be theoretically constrained, the penetration of components of an early-vulcanization composition into polyisoprene particles is considered a function of the diffusion process, which can be a linear function of time. Component penetration involves an exponential function of temperature and reflects a thermally activated process. Therefore, increasing the temperature by a few degrees during the early-vulcanization step increases the early-vulcanization rate. For example, early-vulcanization at room temperature can take about 3-5 days or up to about 9 days, while early-vulcanization at, for example, about 50-70°C can take about 3-7 hours. Without early-vulcanization of synthetic polyisoprene particles, crosslinking occurs mainly around the synthetic polyisoprene particles (i.e., during quenching), resulting in weak particles. As will be discussed below, attempting to crosslink interparticle regions within particles only during post-vulcanization leads to excessive crosslinking of the intraparticle regions, resulting in poor stretchability of the latex product.

[0073] Post-vulcanization compositions include amorphous or polysulfidated materials, which are insoluble at latex emulsion temperatures, e.g., 20-40°C, but soluble at vulcanization or curing temperatures, e.g., 110-150°C (e.g., approximately, or at least approximately, 110, 115, 120, 125, 130, 135, 140, 145, or 150°C, or any range in between). Generally, post-vulcanization compositions include accelerators such as zinc diethyldithiocarbamate (ZDEC), zinc dibutyldithiocarbamate (ZDBC), sodium diethyldithiocarminate (SDEC), sodium dibutyldithiocarbamate (SDBC), thiram compounds, and xanthogenes. Examples of suitable xanthogens include, but are not limited to, diisopropyl xanthogen polysulfide (DIXP), diisopropyl xanthogen, tetraethyl thiuram disulfide, and xanthogen sulfides. DIXP is a suitable xanthogen due to its polysulfate donor properties. The post-sulfurization composition may further contain a thiuram accelerator. An example of a polysulfide thiuram accelerator is dipentamethylenethiuram tetrasulfide (DPTT). Another example of a thiuram compound is tetrabenzyl thiuram disulfide. Zinc oxide may be added as an activator.

[0074] The post-vulcanization composition provides the ability to crosslink the interparticles or interparticle regions of the synthetic polyisoprene, thereby ensuring a high-quality, substantially uniformly cured synthetic polyisoprene product.

[0075] The post-vulcanization composition activates interparticle crosslinking at temperatures such as 100-150°C (e.g., approximately, or at least approximately, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, or 150°C, or any range in between). In addition, the post-vulcanization process also crosslinks the synthetic polyisoprene particles with sulfur. Such post-vulcanization results in a more homogeneous latex coating with greater strength and elongation properties. The resulting composition can be stable for up to approximately 5 days at 20-25°C, making it useful for production lines.

[0076] Table 1 shows exemplary embodiments of rare earth (RE) catalyzed synthetic polyisoprene resin latex compositions for producing polymer compound products. The latex composition is preferably aqueous. [Table 1]

[0077] Table 1 shows a typical mixing sequence for aqueous synthetic latex emulsions: Phase I: 3-5 days at 20-30°C. Add chemicals for early vulcanization, including a surfactant package containing sulfur, ZDEC / ZDBC, potassium caprylate, and polyoxyethylene cetyl / stearyl ether. Phase II: Before immersion. If the TSI index is less than 100%, add a post-vulcanization sulfur source and accelerator, including DXP, SDBC, SDEC, tetrabenzyl thiuram disulfide, and a surfactant.

[0078] Table 2 shows exemplary embodiments of the properties of rare earth (RE) catalyzed synthetic polyisoprene resin latex compositions for producing polymer compound products. [Table 2]

[0079] Table 3 shows a comparison of the early vulcanization behavior of exemplary anionic polyisoprene, exemplary Ziegler-Natta catalytically synthesized polyisoprene resin, and exemplary rare-earth catalytically synthesized polyisoprene resin. [Table 3]

[0080] This disclosure further provides a method for forming a synthetic polyisoprene polymer compound product. This method includes placing an elastomer coating of a rare-earth catalytic polyisoprene material into a mold and curing the elastomer coating to form an elastomer layer of the polymer compound product. The placement step may include immersing a mold that is free of or coated with a coagulant in an emulsion of a rare-earth catalytic polyisoprene material, which may be an aqueous latex composition listed in Table 1 having pre-vulcanized particles, and forming at least once a thin layer of latex or elastomer coating having individual particles of pre-vulcanized synthetic polyisoprene on the surface of the mold. The mold may be any suitable mold as is known in the art. The compositions of the present invention are particularly useful for coating condom molds.

[0081] Embodiments of the rare earth catalytic formulations disclosed in Table 1, which may use the RE PI resins shown in Tables 2-3 and other RE catalytic formulations, can be used to make condoms that contain more cis properties of the polyisoprene molecule, such as cis-1,4 isomers, than anionic catalytic polyisoprene and Ziegler-Natta catalytic polyisoprene, thereby improving the strength properties of products made from synthetic rare earth catalytic polyisoprene.

[0082] Furthermore, the exemplary rare-earth catalytic formulations in Table 1 have potentially lower total solids content and can produce thinner condoms (e.g., thicknesses ranging from approximately 0.030 mm to approximately 0.065 mm, e.g., approximately 0.050 mm to approximately 0.065 mm). Additionally, the exemplary rare-earth catalytic formulations in Table 1 have potentially lower viscosity (e.g., approximately 30 to approximately 40 cps) during the immersion process, thereby enabling the production of thinner condoms. The lower viscosity also allows for faster line speeds during production.

[0083] Furthermore, the rare-earth catalytic formulations in Table 1 produce smaller particle sizes, enabling thinner films and improving sensitivity during use. The smaller particles also exhibit improved crosslinking, which improves the processability of thinner products. For example, this prevents condoms or gloves from falling apart during the washing process, allowing the powder to coat both the inside and outside evenly, thus reducing defects.

[0084] Table 4 lists typical dipping methods for manufacturing condoms using pre-vulcanized rare-earth catalyst polyisoprene resin, as described above in Table 1. [Table 4]

[0085] The method of immersing condoms using a synthetic polyisoprene latex composition stabilized with a surfactant and pre-vulcanized is typically completed within 5 days, for example, within the average lifespan of a synthetic polyisoprene latex emulsion tank. The condom mold is immersed in the composition during the first immersion. The wall thickness of the latex coating is controlled by the viscosity of the latex, which is a function of the total solids content of the composition in the immersion tank. The movement speed of the mold during immersion also affects the wall thickness. The latex coating coating the mold is dried at approximately 60-100°C for approximately 1-3 minutes. The latex coating on the mold is optionally immersed again in the composition to apply a second immersion coating. The latex coating after the second immersion is dried at approximately 60-80°C for approximately 1-3 minutes. The open end of the condom is rolled up to form a rim ring at the distal end of the closed end of the condom.

[0086] The coating can be post-vulcanized, for example, by heating the coating at approximately 110-150°C for approximately 8-15 minutes to form the elastomer layer of the condom. Exemplary embodiments include post-vulcanization achieved by heating in an oven at approximately 120°C for approximately 12 minutes. During this period, interparticle regions are crosslinked. Intraparticle regions also undergo further crosslinking, producing a more homogeneous latex product. The condom is optionally immersed in water at approximately 70-80°C for approximately 1-2 minutes to remove residual surfactants and crosslinking agents from the condom. The condom is then peeled from the mold. Latex products such as condoms exhibit higher strength and improved elasticity, even when using low-stereoregularity synthetic polyisoprene. Synthetic polyisoprene products do not contain proteins that cause latex sensitivity problems and inflammation.

[0087] Embodiments according to this disclosure include the use of a coagulant solution for wetting the mold, the coagulant solution may include an exemplary aqueous solution of 5% calcium nitrate, but other concentrations known to those skilled in the art are possible, such as aqueous solutions of calcium nitrate in the range of 6 to 40%. Other salts and / or mixtures thereof, such as calcium chloride, calcium citrate, and aluminum sulfate, may be used. Furthermore, the coagulant solution may be aqueous, alcoholic, or a mixture of aqueous and alcoholic solutions / solvents. Weak acid solutions may be used as coagulants, as known to those skilled in the art, such as formic acid, acetic acid, and other low pKa acids (e.g., acids having a pKa in the range of about 3 to about 7).

[0088] Embodiments provided herein include the use of early and post-vulcanization methods, the techniques of which are disclosed in U.S. Patents No. 8,087,412, No. 8,464,719, No. 9,725,539 and No. 10,538,609 by the same applicant, which are incorporated in their entirety by reference. Inter-crosslinked molecular weight (M c Methods for determining the ) are disclosed in U.S. Patents No. 8,087,412, No. 8,464,719, No. 9,725,539, and No. 10,538,609.

[0089] In one embodiment, a latex formulation for early vulcanization and / or post-vulcanization, or a product containing or comprising a latex formulation, for example, a personal protective device, for example, a condom. c is less than or approximately less than 10750, 10500, 10250, 10000, 9750, 9500, 9250, 9000, 8800, 8600, 8400, 8200, 8000, 7800, 7600, 7400, 7200, 7000, 6900, 6800, 6700, 6600, or 6550 g / mol. In one embodiment, M c It is less than approximately 6540 g / mol. [Examples]

[0090] Example 1 Condoms were manufactured using the formulations shown in Table 1. Tables 5-1, 5-2, and 5-3 show exemplary properties of the condoms described herein, manufactured using rare earth catalyst-catalyzed polyisoprene resin. [Table 5] [Table 6] [Table 7] A test in accordance with ISO23409:2011, ISO4074:2015, and ASTM D3492-16. Both B ATR and pyrolysis FFIR were used. 13 13C NMR analysis was performed to specifically examine the levels of cis isomerism and evidence of trans or 3,4 isomerism. 13 13C NMR analysis was performed on several solvent-swollen strips in d-chloroform using a 30° pulse, a 3-second pulse delay, and 40,000 pulses. 13 The 13C NMR spectrum showed only peaks associated with cis-1,4-polyisoprene. C Uncoated condoms. Elemental analysis was performed in accordance with SS EN ISO17294-1:2004, ISO17294-2:2016 (amended) and US EPA Method 200.8 Revision 5.4, 1994 (amended), and was modified to use ICP-MS with an inductively coupled plasma sector field mass spectrometer (ICP-SFMS).

[0091] In the method for measuring molecular weight distribution and calculating crosslink density, it is necessary to cut a disc from a condom sample and swell the disc-shaped sample in toluene until equilibrium is reached. The disc is weighed first, and weighed again after swelling. The equilibrium volume fraction of the swollen rubber (V r ) was calculated using the following formula. In this formula, P r is the density of rubber (0.92 g / cm 3 ), P s is the density of toluene (0.862 g / cm 3 ), W r is the weight of the rubber before swelling, and W s is the weight of the swollen rubber. [Formula]

[0092] The crosslink density was calculated by using the volume fraction in the Flory-Rehner equation shown below. In this equation, n is the crosslink density, V s is the molar volume of toluene, which is the swelling solvent, and is 106.3 cm 3 / mol, V r is the volume fraction of the rubber phase in the swollen gel, and χ is the toluene-cis polyisoprene interaction parameter, which is 0.39. [Formula]

[0093] The molecular weight between crosslinks was calculated by the following formula. [Formula]

[0094] Table 6 below reports the measured inter-crosslink molecular weight and corresponding crosslink density for some synthetic polyisoprene condoms manufactured according to embodiments of this disclosure. Higher inter-crosslink molecular weight corresponds to lower crosslink density.

[0095] The presented data demonstrates that the process of this disclosure yields a synthetic polyisoprene condom with a very consistent molecular weight between crosslinks, providing a condom with appropriate mechanical properties. The intercrosslink molecular weight (M) of the condom according to this embodiment. c The density can be 6,540 g / mol. The crosslinking density according to this embodiment is 0.000141 mol / cm³. 3 This is 0.000159 mol / cm³. 3 Its crosslink density is comparable to that of natural rubber, which has a crosslink density of [value missing]. [Table 8]

[0096] Figure 2A shows a first transmission electron microscope (TEM) image of the surface of the condom, and Figure 2B is an annotated version of Figure 2A according to an embodiment of the present disclosure. Figure 3 shows a second TEM image of the surface of the condom according to an embodiment of the present disclosure. Figure 4 shows a third TEM image of the surface of the condom according to an embodiment of the present disclosure. Figure 5 shows a fourth TEM image of the surface of the condom according to an embodiment of the present disclosure. Figure 6 shows a fifth TEM image of the surface of the condom according to an embodiment of the present disclosure. Figure 7A shows a sixth TEM image of the surface of the condom, and Figure 7B is an annotated version of Figure 7A according to an embodiment of the present disclosure.

[0097] The condoms studied in the TEM images of Figures 2A, 3, 4, 5, 6, and 7A were prepared as follows: Each condom was washed with propane-2-ol to remove the lubricant, then immersed in propane-2-ol containing a small amount of talc to prevent sticking and thus facilitate handling. The condoms were then air-dried. Using a parallel two-blade cutter with a nominal blade spacing of 10 mm, numerous rings were cut from the condoms. These rings were analyzed using two methods: network visualization by TEM and equilibrium swelling. r Used for measurement.

[0098] To visualize the network, condom fragments were first extracted overnight in a Soxhlet extractor using high-temperature acetone. The samples were then dried and swelled to equilibrium in a styrene solution containing 1% by weight of benzoyl peroxide initiator and 2% by weight of dibutyl phthalate plasticizer to aid in sectioning. The swollen films were then placed in capsules containing excess styrene solution and heated at 50–55°C until the styrene had completely polymerized and hardened sufficiently to produce good sections.

[0099] Ultrathin sections of the sample were prepared by micro-excision at room temperature using a diamond knife. The sections were collected in a bath filled with water and then stretched with xylene vapor before being collected on a TEM grid. All sections were then stained with osmium tetroxide vapor for 7 minutes. Osmium tetroxide reacts with carbon-carbon double bonds, thereby increasing the electron density of polymer compounds containing unsaturated groups. Therefore, unsaturated polymer compounds such as polyisoprene appear darker on TEM compared to polystyrene.

[0100] The rubber within the latex particles is cross-linked, thus forming a styrene-swollen rubber network. This rubber network is visible both within and between the latex particles. The rubber latex particles have diffusion boundaries but are discernible. This indicates a tendency to resist separation of the latex particles, caused by styrene swelling in these regions. There are also polystyrene "gaps," which are regions where the rubber network is weak and styrene has permeated the structure. Some of these gaps contain small, dark particles of a more electron-density material. In gaps observed without particles, the particles may have been above or below the plane of the microscopic section.

[0101] The uncertainty in scale bar dimensions is ±10% in all TEM micrographs.

[0102] Figure 2B shows the contours of PI particles, with a scale of 5 micrometers (μm), annotated by shapes 205, 210, 215, 220, 225, 230, and 235. The crosslinking is substantially uniform throughout the thickness.

[0103] Figure 7B shows the contours of PI particles, with a scale of 1 micrometer (μm), annotated by shapes 240 and 245. The crosslinking is substantially uniform throughout the thickness.

[0104] Exemplary Example This disclosure may rely on one or more of the following exemplary embodiments.

[0105] Embodiment (a). A polymer compound product comprising an elastomer layer, the elastomer layer comprising early vulcanization-cured synthetic polyisoprene particles, the early vulcanization-cured synthetic polyisoprene particles comprising a plurality of sulfur crosslinks and rare earth catalytic polyisoprene material, the rare earth catalytic polyisoprene material comprising more than 97.0% by weight of cis-1,4 isomer components and rare earth element components of 0.1 mg / kg or more and 100 mg / kg or less, and the synthetic polyisoprene particles being early vulcanized.

[0106] Embodiment (b). The polymer compound product according to Embodiment (a), wherein the rare earth catalyzed polyisoprene material contains 97.75% or more by weight, 97.50% or more by weight, 98.00% or more by weight, 98.25% or more by weight, 98.50% or more by weight, 98.75% or more by weight, 99.00% or more by weight, or 99.25% or more by weight of the cis-1,4 isomer component.

[0107] Embodiment (c). The polymer compound product according to Embodiment (a) or (b), wherein the cis-1,4 isomer component is approximately 99.5% by weight or more.

[0108] Embodiment (d). A polymer compound product according to any one of Embodiments (a) to (c), wherein the rare earth-catalyzed polyisoprene material contains 0.50% by weight or less of a trans-1,4 isomer component, optionally, approximately 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15 or 0.10% by weight, less than or approximately less than a trans-1,4 isomer component.

[0109] Embodiment (e). A polymer compound product according to any one of Embodiments (a) to (d), wherein the rare earth-catalyzed polyisoprene material comprises 3.00% by weight or less of 3,4 isomer components, optionally, approximately 3.00, 2.75, 2.50, 2.25, 2.00, 1.75, 1.50, 1.25, 1.00, 0.75, or 0.50% by weight, less than, or approximately less than, 3,4 isomer components.

[0110] Embodiment (f). A polymer compound product according to any one of Embodiments (a) to (e), wherein the product has a thickness in the range of about 0.050 to about 0.075 mm, in the range of about 0.050 to about 0.065 mm, in the range of about 0.060 to about 0.075 mm, in the range of about 0.030 to about 0.065 mm, in the range of about 0.030 to about 0.075 mm, or a thickness of approximately 0.075, 0.070, 0.065, 0.060, 0.055, or 0.050, 0.045, 0.040, 0.035, or 0.030 mm, or approximately less than that.

[0111] Embodiment (g). The elastomer layer has an intercrosslink molecular weight (M) of 10750, 10500, 10250, 10000, 9750, 9500, 9250, 9000, 8800, 8600, 8400, 8200, 8000, 7800, 7600, 7400, 7200, 7000, 6900, 6800, 6700, 6600, or less than 6550 g / mol, approximately less than that, or less than 6540 g / mol, or about 6540 g / mol. c A polymer compound product according to any one of embodiments (a) to (f), comprising a post-vulcanization structure having ).

[0112] Embodiment (h). A polymer compound product according to any one of Embodiments (a) to (g), wherein the synthetic polyisoprene particles have the same, approximately the same, at least the same, or at least approximately the same as, a median or maximum median particle diameter from approximately 1 micrometer as, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0 micrometers.

[0113] Embodiment (i1). A polymer compound product according to any one of Embodiments (a) to (h), wherein synthetic polyisoprene particles are bonded to each other via intra-polyisoprene particle crosslinking and inter-polyisoprene particle crosslinking.

[0114] Embodiment (i2). The polymer compound product according to any one of Embodiments (a) to (i2), wherein the polymer compound product is a personal protective device optionally selected from gloves and condoms.

[0115] Embodiment (j). A condom comprising an elastomer layer, the elastomer layer comprising cured synthetic polyisoprene particles, the cured synthetic polyisoprene particles being pre-vulcanized and comprising sulfur crosslinking, the synthetic polyisoprene particles comprising a rare earth catalytic polyisoprene material, the rare earth catalytic polyisoprene material comprising more than 97.0% by weight of a cis-1,4 isomer component, 1% by weight or less of a trans-1,4 isomer component, and 1% by weight or less of a 3,4 isomer component.

[0116] Embodiment (k). The condom according to Embodiment (j), wherein the elastomer layer forms an open end, a closed end, and a tubular sheath extending from the closed end to the open end.

[0117] Embodiment (l). A condom according to Embodiment (j) or (k), wherein the rare earth-catalyzed polyisoprene material includes a branched macrostructure.

[0118] Embodiment (m). The elastomer layer has an intercrosslink molecular weight (M) of 10750, 10500, 10250, 10000, 9750, 9500, 9250, 9000, 8800, 8600, 8400, 8200, 8000, 7800, 7600, 7400, 7200, 7000, 6900, 6800, 6700, 6600, or less than 6550 g / mol, or approximately less than 6,540 g / mol, or less than 6,540 g / mol. c A condom according to any one of embodiments (j) to (l), comprising a post-vulcanization structure having ).

[0119] Embodiment (n). A condom according to any one of Embodiments (j) to (m), wherein the synthetic polyisoprene particles have a median or maximum median particle diameter that is the same as, approximately the same as, at least the same as, or at least approximately the same as, or approximately 1 micrometer, or 2.0 micrometers.

[0120] Embodiment (o). A method for producing a polymer compound product, comprising: pre-vulcanizing an emulsion containing a rare-earth catalytic polyisoprene material containing more than 97.0% by weight of cis-1,4 isomer components; placing an elastomer coating of the emulsion containing the rare-earth catalytic polyisoprene material in a mold; and curing the elastomer coating to form an elastomer layer of a polymer compound product, wherein the elastomer layer comprises sulfur-crosslinked cured synthetic polyisoprene particles and a rare-earth element component of 0.1 mg / kg or more and 100 mg / kg or less.

[0121] Embodiment (p). The method according to Embodiment (o), wherein the polymer compound product comprises a condom, and the elastomer layer forms an open end, a closed end, and a tubular sheath extending from the closed end to the open end.

[0122] Embodiment (q). The method according to Embodiment (o) or (p), wherein the cured synthetic polyisoprene particles include both intra-polyisoprene sulfur crosslinking and inter-polyisoprene sulfur crosslinking.

[0123] Embodiment (r). The method according to any one of Embodiments (o) to (q), wherein the post-vulcanization composition is added to the emulsion before the emulsion is placed in a mold.

[0124] Embodiment(s). A product manufactured by the method described in any one of Embodiments(o) to(r).

[0125] Embodiment (t). The product according to any one of embodiments (a) to (i2) or (s), wherein the product is a condom.

[0126] For ease of understanding, the same reference numerals are used to designate equivalent elements common to the drawings, where possible. The drawings are not drawn to scale and may be simplified for clarity. It is expected that elements and features of one embodiment can be usefully incorporated into other embodiments without further enumeration.

[0127] It should be understood that various changes and modifications to the embodiments described herein will be obvious to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of this disclosure and without preserving any incidental advantages. Accordingly, such changes and modifications are intended to be covered by the appended claims.

[0128] Those skilled in the art will understand that numerous changes and / or modifications can be made to the embodiments described above without departing from the broad general scope of this disclosure. Accordingly, these embodiments should be considered in all respects as illustrative and not limiting.

Claims

1. It is a condom, It contains an elastomer layer, The elastomer layer contains cured synthetic polyisoprene particles, which are pre-vulcanized and contain sulfur crosslinks. The cured synthetic polyisoprene particles include a rare earth catalyst-catalyzed polyisoprene material. The aforementioned rare earth catalyst-catalyzed polyisoprene material is Containing over 97.0% by weight of cis-1,4 isomers, Content of trans-1,4 isomers of 1% by weight or less, Content of 3,4 isomers of 1% by weight or less Condoms, including...

2. The condom according to claim 1, wherein the elastomer layer forms an open end, a closed end, and a tubular sheath extending from the closed end to the open end.

3. The condom according to claim 1 or 2, wherein the rare earth-catalyzed polyisoprene material includes a branched macrostructure.

4. The elastomer layer is a post-sulfurized structure having an intercrosslink molecular weight (Mc) of less than 10500, 10250, 10000, 9750, 9500, 9250, 9000, 8800, 8600, 8400, 8200, 8000, 7800, 7600, 7400, 7200, 7000, 6900, 6800, 6700, 6600 or 6550 g / mol, or an intercrosslink molecular weight (Mc) of less than 6540 g / mol. ｃ The condom according to claim 1, comprising a post-vulcanization structure having ).

5. The condom according to claim 1, wherein the cured synthetic polyisoprene particles have a median particle diameter of about 1 micrometer or less.

6. The condom according to claim 1, wherein the rare earth catalyst-catalyzed polyisoprene material has a cis-1,4 isomer content of 99.0% by weight or more.

7. The condom according to claim 1, wherein the cis-1,4 isomer content is 99.5% by weight.

8. The condom according to claim 1, wherein the rare earth catalyst-catalyzed polyisoprene material has a trans-1,4 isomer content of 0.5% by weight or less.

9. The condom according to claim 1, wherein the rare earth catalyst-catalyzed polyisoprene material has a content of 3,4 isomers of 1% by weight or less.

10. The condom according to claim 1, wherein the condom has a thickness in the range of 0.050 to 0.065 mm.

11. A method for manufacturing condoms, Early vulcanization of an emulsion containing a rare-earth catalyst-catalyzed polyisoprene material having a cis-1,4 isomer content exceeding 97.0% by weight, Placing an elastomer coating of the emulsion containing the rare earth catalyst-activated polyisoprene material in a mold, The elastomer coating is cured to form the elastomer layer of the condom. Includes, The aforementioned elastomer layer is Sulfur-crosslinked cured synthetic polyisoprene particles, Rare earth element content of 0.1 mg / kg or more and 100 mg / kg or less Methods that include...

12. The method according to claim 11, wherein the elastomer layer forms an open end, a closed end, and a tubular sheath extending from the closed end to the open end.

13. The method according to claim 11 or 12, wherein the cured synthetic polyisoprene particles include both intraparticle sulfur crosslinking and interparticle sulfur crosslinking.

14. The method according to claim 11, wherein a post-vulcanization composition is added to the emulsion before the emulsion is placed in the mold.

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