RU2776750C2 - Cross-linked styrene block copolymer - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to styrene block copolymers cross-linked both physically and chemically. Options of a composition of elastomeric styrene block copolymers (hereinafter – SBC) are proposed, containing one or several SBC copolymers and one or several polymers mixed with styrene end blocks of one or several SBC copolymers. At the same time, compositions of block copolymers are both physically and chemically cross-linked. Moreover, chemical cross-linking includes covalent bounds between chains of SBC copolymers, and a cross-linking agent is selected from multifunctional acrylates, and physical cross-linking includes non-covalent interactions between styrene end blocks of one or several SBC copolymers and one or several polymers mixed with styrene end blocks. A method for the production of the specified composition, and films obtained from it are also proposed. Compositions of block copolymers can be used for the manufacture of elastic products by a dipping method.

EFFECT: obtaining products with improved operational characteristics.

32 cl, 1 tbl, 3 ex

Description

Technical field

The present disclosure relates to styrene block copolymers that are both physically and chemically crosslinked. These copolymers find their preferred use in the manufacture of elastic dipped articles such as gloves and condoms.

Prerequisites

Thin-walled elastic dipped products are traditionally made from natural rubber (NR), polychloroprene (CR), polyisoprene (IR), polyurethane (PU), nitrile rubber (NBR), styrene block copolymers (SBC), mixtures thereof or combinations of such layers (laminates).

In these applications, natural rubber is used because it is a natural product that has exceptional performance. However, the presence of sensitizing proteins responsible for immediate hypersensitivity (type I allergies) has limited its use. To eliminate this drawback, synthetic materials have been developed as alternatives.

Typical Processing

Thin-walled elastic films are usually formed for the intended application (glove, condom, etc.) by immersing an appropriately shaped mold in a liquid polymer mixture, which may be either a dispersion in water (latex) or a solution in one or more suitable solvents. A hard film is formed after the evaporation of water or other solvents.

Improved performance in terms of mechanical and chemical properties, elasticity and durability of the material is achieved by the crosslinking mechanism. Vulcanization is the traditional chemical crosslinking mechanism for materials with superior elastomeric properties such as NR or IR. During vulcanization, sulfur covalent bonds are formed that connect one polymer chain to another. However, since vulcanization using sulfur alone requires reaction conditions that require too long times and very high temperatures, chemical additives such as "accelerators" are also added. Accelerators can be of many types and are generally grouped into the following families: thiazoles, carbamates, guanidines, thioureas and thiurams. To optimize the speed and performance of vulcanization in practice usually use a mixture of different accelerators selected from these different families.

However, while sulfur is incorporated into the polymer network via covalent bonds, accelerators are not. A typical polyisoprene glove composition may contain up to 2% accelerators. Accelerator molecules have low water solubility and cannot be removed from the glove by rinsing. In addition, over time they can form a “bloom” on the surface of the film due to their limited compatibility with rubber. Accelerators are also strong skin sensitizers and can cause allergic contact dermatitis (immediate type hypersensitivity, type IV).

Product Performance

The performance characteristics of the resulting product are usually determined by the specific combination of materials, the conditions for preparing the mixture and the method of conversion to a thin film.

The more common elastomers are NR, CR, IR, and NBR, and all of these are converted into thin-walled films using aqueous dispersions, also known as latexes, as the starting material. However, thin-walled films made from latexes have the disadvantage that the resulting products are sometimes prone to the presence of pinholes. These pinholes are often on the order of micrometers in diameter and may be due to small amounts of impurities in the latex that are difficult to filter out, as well as the fact that a heterogeneous system (dispersion) turns into a film. There is some inherent microporosity in rubber, which can be explained by the inability of all latex particles that make up a typical film to completely merge with each other (coalesce) and form a continuous film that does not contain internal voids. Natural proteins (present in NR) and chemicals (surfactants, mainly in the case of synthetic polymers) used to stabilize the latex and in the manufacturing process tend to retard coalescence.

Preferably, certain other synthetic polymers can be dissolved in solvents such as hydrocarbon solvents to form a true solution. Accordingly, solution forming technology is attractive for the production of films requiring very high quality and almost devoid of microporosity. The presence of pinholes in such a case is also much less likely.

Rubber-based multiblock copolymers, and especially styrene block copolymers (SBC copolymers), are particularly well suited to dip molding processes because they can form solutions with acceptable viscosities that can be used for dipping.

Styrene block copolymers

SBC copolymers belong to a class of thermoplastic elastomers that have the mechanical properties of rubbers and the technological characteristics of thermoplastics. These properties are due to their molecular structure. SBCs consist of at least three blocks, typically two hard polystyrene end blocks and one soft, elastomeric (polybutadiene, hydrogenated or non-hydrogenated polyisoprene) middle block. More common SBC copolymers contain linear triblock copolymers such as styrene-ethylene/butylene-styrene (SEBS), styrene-butadiene-styrene (SBS) and styrene-isoprene-styrene (SIS), but other configurations are also possible (for example, copolymers consisting of more than 3 blocks) and structure (star or radial).

The hard and soft blocks do not mix with each other, so on a microscopic scale, the polystyrene blocks form separate domains in the rubber matrix. With this in mind, SBC copolymers show two glass transition temperatures (Tg) characteristic of the respective homopolymers (polystyrene end block at 90-100°C and rubber middle block at about -90°C in the case of, for example, polybutadiene).

In addition to the benefits of true solution operation, SBC copolymers are capable of forming high mechanical performance elastic films without the use of any chemical crosslinking such as sulfur and accelerators because both ends of each of the rubber blocks are terminated with polystyrene segments and these rigid the domains act as multi-functional interface points to form a "physically" cross-linked elastomer network similar in many respects to that of traditional vulcanized rubber ("chemical cross-linking").

Finally, said elastomers may preferably be formulated with suitable plasticizers to provide the desired combination of tensile strength, elasticity and tactile feel, as required, for example, for surgical gloves.

Critical breaking strength and tensile strength are important factors in evaluating the performance of stretchable thin-walled films such as condoms or gloves, which should be evaluated according to international standards. In addition, the surgical glove must provide high sensitivity while not squeezing the user's hand for a long period of time. To prevent compression of the hand, a modulus at 100% elongation of less than 1.0 MPa and ideally less than 0.7 MPa is preferred.

Suitably formulated with a plasticizer, SBC copolymers can meet all international standards and achieve comparable, and in many cases superior, flexibility and mechanical performance to those of other elastomers such as NRL, CR, IR. This means that such a material can function in a mechanically comparable or more advantageous manner than other elastomers while avoiding the disadvantages of latex based elastomers such as the presence of accelerators and pinholes.

In summary, SBCs are particularly well suited for use in thin-walled film applications such as medical gloves, providing excellent properties including the use of synthetic rubber free of natural rubber proteins, no accelerators; softness, as well as the formation of films of very high quality, almost without pinholes and hydration.

SBC copolymer compositions suitable for use in surgical gloves are described in EP0488021, which discloses a combination of two or more S-EB-S block copolymers, and EP1472315, which discloses a combination of one S-EB-S block copolymer and one S-EB-S block copolymer. copolymer S-EP-S-EP.

Limitations of styrene block copolymers

Products made from the SBC copolymers described in the patents mentioned above have a major disadvantage. Because the polymer network is formed by only physical cross-links and not chemical cross-links, the glassy domains of polystyrene soften and lose their cohesion upon contact with certain organic solvents.

For example, surgical gloves made from SBC copolymers are destroyed in case of direct contact with organic solvents. In the medical field, several organic solvents and "harsh" chemicals may be used. One example is monomeric methyl methacrylate (MMA), which is present in uncured bone cement used in arthroplasty. MMA has a Hansen solubility parameter of 17.9 MPa ^1/2 , which is close to the corresponding PS parameter (18.6). Another example is diethyl ether, which is used as a solvent in some formulations such as collodion. Poor chemical resistance to these solvents is a major limitation of this family of elastomers for surgical gloves.

The physical network can be strengthened by adding a chemical network through strong covalent bonds connecting the elastomeric phase chains to form an insoluble material. Decker et al, Journal of Applied Polymer Science (vol. 77, 1902-1912, 2000) describes an example using commercially available SBS and SIS tri-block copolymers crosslinked by UV light in the presence of a radical type photoinitiator. The crosslinking process can be markedly accelerated by the addition of multifunctional organic molecules, such as acrylate or thiol monomers, which can copolymerize with polybutadiene or polyisoprene at the unsaturation.

However, this process of chemical crosslinking leads to a sharp deterioration in the mechanical properties of the film, since the coexistence of two networks (one "physical" and one "chemical") reduces the mechanical resistance and increases the rigidity of the material.

Such materials would not, for example, achieve international standards for surgical gloves, such as minimum tensile strength as described in ASTM D3577.

In view of the foregoing, it would be desirable to develop alternative SBC compositions and methods for their preparation that would solve one or more of the problems mentioned above and eliminate one or more of the disadvantages mentioned above.

Reference in this specification to any prior publication (or information derived from such publication), or to any prior art, is not and should not be taken as an admission, endorsement, or any form of suggestion that that prior publication (or information derived from from it) or known information forms part of the publicly available information in the field of activity to which this description relates.

The essence of the invention

One aspect of the present disclosure relates to an elastomeric styrene block copolymer (SBC) composition comprising one or more SBC copolymers and one or more polymers miscible with styrene end blocks of one or more SBC copolymers;

wherein said composition of block copolymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between SBC chains; and

where said physical crosslinking involves a non-covalent interaction between the styrene end blocks of one or more SBC copolymers and one or more polymers miscible with the styrene end blocks.

Another aspect of the present disclosure relates to a mixture of miscible polymers containing one or more SBC copolymers and one or more polymers miscible with styrenic end blocks of one or more SBC copolymers;

wherein said mixture of miscible polymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers; and

where said physical crosslinking involves a non-covalent interaction between the styrene end blocks of one or more SBC copolymers and one or more polymers miscible with the styrene end blocks.

The unique compositions or blends disclosed herein containing physically and chemically crosslinked styrene block copolymers find use, for example, in the manufacture of thin-walled dipped products such as condoms and medical gloves. These unique compositions or blends overcome the chemical resistance disadvantage of currently available SBC copolymers while maintaining a high level of mechanical resistance and flexibility.

Another aspect of the present disclosure relates to a styrene elastomeric block copolymer composition comprising:

(a) one or more SBC copolymers;

(b) one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers; and

(c) one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers.

In another aspect, a process is provided for preparing an SBC copolymer composition, comprising the step of combining one or more SBC copolymers, one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers, and one or more crosslinkers capable of providing covalent bonding between chains of one or more several SBC copolymers.

The compositions or blends of the invention may further comprise one or more plasticizers and/or softeners compatible with the elastomeric middle block of one or more SBC copolymers.

The compositions or blends of the invention may further comprise one or more compatibilizers that enhance miscibility between the styrenic end blocks of one or more SBC copolymers and one or more miscible polymers. Such compatibilizers may be, for example, surfactants, and more particularly polymeric surfactants such as di-block copolymers containing a PS segment or a low molecular weight polymer or resin having an appropriate solubility parameter. .

One or more SBCs may contain a fully or partially unsaturated elastomeric midblock, or may contain a fully saturated elastomeric midblock.

One or more SBC copolymers may be selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS, or SBC copolymers containing reactive functional groups grafted into the middle rubber block, such as, for example, groups of carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof.

Preferably the SBC is formed by a single SBC copolymer or a mixture of copolymers with a molecular weight (Mn) greater than 100,000 g/mol. Preferably, the elastomeric middle block of at least one SBC copolymer contains reactive functional groups such as double bonds, such as carbon-carbon double bonds, to allow chemical crosslinking.

The polymer miscible with the polystyrene end blocks may be a polymer capable of forming a molecularly homogeneous mixture with the polystyrene end blocks to a certain extent. The miscible polymer may be a polymer that is miscible with polystyrene, i.e. SBC, and the miscible polymer may form a homogeneous mixture due to chemical similarity and/or as a result of specific interactions such as, for example, between π-bonds in arene rings. These interactions may be non-covalent in nature. These interactions may not involve covalent bonds between the SBC and the miscible polymer.

Preferably, the number average molecular weight of the miscible polymer (Mn) is less than 10,000 g/mol, and more preferably less than 3,000 g/mol.

Preferably the miscible polymer has a significant molecular weight polydispersity factor, for example greater than 2.0 or greater than 3.0 or greater than 4.0 or greater than 5.0. Preferably, the miscible polymer has a polarity similar to that of polystyrene.

In a preferred embodiment, the miscible polymers are selected from copolymers of low molecular weight alkylarene monomers.

The miscible polymer may be selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins, and mixtures thereof.

The crosslinking agent may be selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylol propane triacrylate (TMPTA), trimethylol propane trimethacrylate (TMPTMA ), epoxy acrylates, urethane acrylates; triallyl cyanurate, triallyl isocyanurate; functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, trimethylolpropane ethoxylated tri-3-mercaptopropionate, as well as other polyfunctional compounds with vinyl or allyl groups, and their mixtures.

The crosslinking agent may also be a metal salt, an amine crosslinker selected from the group consisting of an organic amine, an organic diamine and an organic polyamine, or a polyol.

Chemical crosslinking can also be carried out by so-called "vulcanization", in which case the crosslinking agent can be selected from common sulfur, metal oxides and accelerators commonly used to vulcanize rubber in the case of thin-walled elastic films such as condoms and gloves. Vulcanization is not considered to be the preferred method of crosslinking in an aspect of the present disclosure because accelerators, which are strong skin sensitizers, do not build into the chemical network and may form a coating on the surface.

In a preferred embodiment, the crosslinking reaction is a thiol-ene reaction. The thiol-ene reaction is the so-called "click" reaction, which proceeds as an addition reaction activated by radicals.

Preferably, the crosslinker is selected, for example, from dithiol, trithiol and tetrathiol molecules containing ether or ester groups in their main chain.

Preferably, the crosslinking reaction can be stimulated by exposure to radiation, such as UV, gamma radiation, x-rays or electron beam radiation. Irradiation brings numerous benefits: the energy is high enough to generate radicals of the chemicals present, there is less risk of shading effects that can be seen with UV curing, and the technology also provides good and accurate dosage control. It should also be noted that most surgical gloves are sterilized by exposure to radiation (either electron beam or gamma radiation), therefore, crosslinking can preferably take place during the same process as the sterilization of gloves.

In another embodiment, the crosslinking reaction can be initiated or accelerated using a radical-type photoinitiator alone or a mixture thereof.

The photoinitiator for use is preferably selected from those compounds which are characterized by broad UV absorption spectra and efficient formation of reactive radicals upon irradiation, combined with good solubility in resin systems, as well as good skin tolerability. The photoinitiator may, for example, be selected from the group consisting of acylphosphine oxides, such as monoacylphosphine oxides, bis-acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or other substances such as 2-hydroxymethyl-1-phenylpropanone, methylbenzoyl formate, and methyl ether. phenylglyoxylic acid.

The plasticizer can improve the stretch and flexibility of the SBC compositions and polymer blends disclosed herein. Preferably, the plasticizer consists of a liquid saturated polyolefin or mixture of such polyolefins compatible with the middle block (elastomeric block) of the SBC copolymer. More preferably, said plasticizer may be selected from compounds that have an onset temperature of 35° C. or lower. In the context of the present disclosure, it is preferred to use plasticizing oils, preferably mineral plasticizing oils, and especially mineral oils derived from a purified mixture of liquid saturated hydrocarbons formed by compounds of a paraffinic or naphthenic nature or mixtures thereof in various proportions.

Preferred plasticizer mineral oils are crystal clear, colorless as water products that are free of toxic impurities and MOAH (Mineral Oil Aromatic Hydrocarbon) and comply with US FDA 21 CFR 178.3620(a), White Mineral Oil, US Pharmacopeia, European Pharmacopeia (liquid paraffin), as well as European Commission regulation (EU) 10/2011 for plastic material and articles intended to come into contact with food; white mineral oil. A preferred mineral oil is medical white oil which has a specific gravity of 0.85-0.90 at 15°C.

The plasticizer may also be an oligomer or other elastomer which has sufficient compatibility with the rubber middle blocks and in this case can be considered more as a "softener". Such softener may be selected from a family including polybutadiene, polyisoprene, polyisobutene, amorphous polyolefin copolymers of propylene and ethylene, butyl rubber, and other polymers known to have sufficient compatibility with the rubber block. Functionalized or reactive softeners such as acrylic or hydroxyl modified polybutadiene can also be used. These reactive softeners can take part in the formation of a chemically crosslinked network.

SBC compositions or blends of miscible polymers in accordance with embodiments of the invention of the present disclosure are characterized in units of PHR (per hundred parts of rubber), wherein the rubber is one or more SBC copolymers. The ranges given in the examples for the contents of the components of the compositions include the following:

Miscible polymer: 0.25 - 100 phr, preferably 5 - 50 phr

Plasticizer / Softener: 0 - 200 phr, preferably 20 - 75 phr

Cross-linker: 0.01 - 5 phr, preferably 0.05 - 1 phr

Photoinitiator: 0 - 5 phr, preferably 0 - 2 phr.

In another aspect, a method is provided for making a dipped article from at least one SBC copolymer composition or blend of miscible polymers disclosed herein, wherein a mold with an outer contour corresponding to the configuration of the dipped article is immersed for a predetermined period of time in a solution. for dipping, containing one or more compositions of SBC copolymers or mixtures of miscible polymers, and in which the article obtained by dipping, then removed from the solution and dried.

After that, this product, in particular the dried product, can be exposed to radiation, such as electron beam, gamma radiation, UV or X-ray radiation.

In yet another aspect, a thin film is provided comprising one or more SBC copolymer compositions or blends of miscible polymers, wherein said thin film has an ASTM 3577 tensile strength greater than 17 MPa and said thin film is substantially insoluble in an organic solvent. .

By "substantially insoluble" can be meant, for example, that at least 80% of a given thin film is insoluble, or at least 95% of the film is insoluble in organic solvents that can be used in the medical field, such as methyl methacrylate (MMA) or diethyl ether.

In another aspect, a composition of elastomeric styrene block copolymers or a blend of miscible polymers is provided, wherein said composition has a tensile strength of at least 17 MPa and said composition is substantially insoluble in an organic solvent.

By "substantially insoluble" may be meant, for example, that at least 80% of the composition is insoluble or at least 95% of the composition is insoluble in organic solvents that may be used in medical applications such as methyl methacrylate (MMA) or diethyl ether.

In yet another aspect, a thin film is provided comprising one or more SBC copolymer compositions or blends of miscible polymers according to any of the embodiments disclosed herein.

In any of the embodiments disclosed herein, the thin film may have a thickness of from about 10 microns to about 500 microns, or from about 150 microns to about 250 microns.

In any of the embodiments disclosed herein, the thin film may have a thickness of less than 500 microns, or less than 400 microns, or less than 300 microns, or less than 200 microns.

In another aspect, a multilayer film is provided comprising one or more layers or thin films, said one or more layers or thin films comprising the SBC compositions or blends of miscible polymers disclosed herein.

In yet another aspect, a multilayer film is provided comprising one or more layers or thin films, said one or more layers or thin films comprising SBC compositions or miscible polymer blends, wherein said miscible polymer composition or blend has a tensile strength of at least 17 MPa. and said composition or mixture of miscible polymers is substantially insoluble in the organic solvent.

A multilayer film can be obtained by superimposing several thin layers made from the same SBC composition or different SBC compositions. The various SBC compositions disclosed herein may be combined into different layers. In addition, at least one layer containing the compositions disclosed herein can be combined with other(s) elastomer(s) selected from the group consisting of natural rubber, polybutadiene, polyisoprene, polychloroprene, butyl rubber, polyurethane, acrylic polymers. and copolymers, silicone elastomers, other SBC copolymers, cyclic block copolymers (CBC) and mixtures thereof. It is understood that the nature of the elastomer(s) forming(them) each of these layers may be the same or different.

According to the present disclosure, the preferred multilayer film components are SBS, SEBS and butyl rubber. In one embodiment, multilayer gloves comprising superimposed layers made from the compositions disclosed herein and butyl rubber have improved resistance to chemical penetration, such as monomeric methyl methacrylate. Such gloves may include, for example, a thin layer of butyl rubber located on the outer layer and/or placed between other layers containing the SBC composition disclosed herein.

Each of the layers comprising the thin-walled elastic film may also contain other auxiliary substances commonly used in the polymer industry and specifically in the manufacture of gloves, such as lubricants and anti-stick agents, antistatic agents, primary and secondary antioxidants, coloring agents. , technological reagents and so on.

In another aspect, a manufactured article is provided comprising one or more of the SBC copolymer compositions or blends of miscible polymers disclosed herein.

The manufactured article may be a medical device such as a medical glove, a condom, or personal protective equipment such as lab or cleaning gloves.

The film or multilayer film of the invention may also include active chemicals.

The nature of the specified active substance can be selected depending on the desired properties. Said active chemical may in particular be selected from anti-corrosion agents, lubricants, chemical markers, phase change products, energy particle (radiation) retarders, disinfectants, perfumes or humectants, cut detection dyes, metal particles, and mixtures thereof.

If the active chemical is a disinfectant product, it is preferably selected from those capable of causing virtually instantaneous denaturation of proteins upon simple contact, either through a chemical reaction or through a physicochemical effect such as a change in surface tension. Among such substances, mention may be made in particular of biocides such as quaternary ammonium compounds, and more particularly dimethyldidecylammonium chloride and benzalkonium chloride; biguanidines such as water-soluble salts of chlorhexidine, for example chlorhexidine digluconate; phthalaldehyde; phenolic derivatives such as hexachlorophene or benzyl derivatives; formaldehyde, nonionic surfactants containing at least one sequence of polyoxyethylene units, such as octoxynol (Triton®X100), hexamidine; iodinated polyvinylpyrrolidone compounds, nonionic surfactants with virucidal activity, sodium and potassium dichromates and hypochlorites, and mixtures thereof.

The present disclosure relates to compositions containing SBC copolymers from which chemically and physically cross-linked thin-walled elastic products with improved mechanical properties can be formed.

Detailed description of embodiments

Before disclosing and describing the present compositions, components, articles and/or methods, it should be understood that, unless otherwise indicated, this invention is not limited to specific compositions, components, articles, methods, or the like, which, in themselves, may vary if not otherwise specified. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the invention.

It should also be noted that the singular forms ('a', 'an' and 'the') used in the description and the appended claims include the corresponding terms in the plural, unless otherwise indicated. Thus, for example, reference to an "SBC" copolymer may include more than one SBC copolymer, and the like.

Disclosed herein are preferred SBC compositions and miscible polymer blends, as well as methods for their preparation.

In an exemplary embodiment, an elastomeric styrene block copolymer (SBC) composition is provided comprising one or more SBC copolymers and one or more polymers miscible with styrene end blocks of one or more SBC copolymers;

wherein said composition of block copolymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof; and

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof.

In another exemplary embodiment, an elastomeric styrene block copolymer (SBC) composition is provided comprising one or more SBC copolymers and one or more polymers miscible with styrene end blocks of one or more SBC copolymers;

wherein said composition of block copolymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof; and

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol, and said miscible polymers have a molecular weight ( Mn) is less than 10,000 g/mol.

In yet another exemplary embodiment, an elastomeric styrene block copolymer (SBC) composition is provided comprising one or more SBC copolymers and one or more polymers miscible with styrene end blocks of one or more SBC copolymers;

wherein said composition of block copolymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene; rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol, and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol mol.

In another exemplary embodiment, an elastomeric styrene block copolymer (SBC) composition is provided comprising one or more SBC copolymers and one or more polymers miscible with styrene end blocks of one or more SBC copolymers;

wherein said composition of block copolymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, alpha-methylstyrene resin, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, and mixtures thereof, said SBC copolymers having a molecular weight of (Mn ) is greater than 100,000 g/mol, and said miscible polymers have a molecular weight (Mn) of less than 10,000 g/mol.

In yet another exemplary embodiment, a miscible polymer blend is provided comprising one or more SBC copolymers and one or more polymers miscible with styrenic end blocks of one or more SBC copolymers;

wherein said formulated blend of miscible polymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof; and

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof.

In another exemplary embodiment, a formulated blend of miscible polymers is provided comprising one or more SBC copolymers and one or more polymers miscible with styrenic end blocks of one or more SBC copolymers;

wherein said formulated blend of miscible polymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol, and said miscible polymers have a molecular weight ( Mn) is less than 10,000 g/mol.

In yet another exemplary embodiment, a miscible polymer blend is provided comprising one or more SBC copolymers and one or more polymers miscible with styrenic end blocks of one or more SBC copolymers;

wherein said formulated blend of miscible polymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene; rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol, and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol mol.

In another exemplary embodiment, a formulated blend of miscible polymers is provided comprising one or more SBC copolymers and one or more polymers miscible with styrenic end blocks of one or more SBC copolymers;

wherein said formulated blend of miscible polymers is both physically and chemically crosslinked;

where said chemical crosslinking includes covalent bonds between chains of SBC copolymers;

where said physical crosslinking includes non-covalent interactions between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, alpha-methylstyrene resin, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, and mixtures thereof, said SBC copolymers having a molecular weight of (Mn ) is greater than 100,000 g/mol, and said miscible polymers have a molecular weight (Mn) of less than 10,000 g/mol.

In yet another exemplary embodiment, a styrene elastomeric block copolymer composition is provided comprising:

(a) one or more SBC copolymers;

(b) one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers; and

(c) one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof;

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof; and

wherein one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethacrylate trimethylolpropane (TMPTMA), epoxy acrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate; functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, trimethylolpropane ethoxylated tri-3-mercaptopropionate, as well as other polyfunctional compounds with vinyl or allyl groups, and their mixtures.

In another exemplary embodiment, a styrene elastomeric block copolymer composition is provided comprising:

(a) one or more SBC copolymers;

(b) one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers; and

(c) one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof;

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof; and

wherein one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethacrylate trimethylolpropane (TMPTMA), epoxy acrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate; functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, trimethylolpropane ethoxylated tri-3-mercaptopropionate, as well as other polyfunctional compounds with vinyl or allyl groups, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In yet another exemplary embodiment, a styrene elastomeric block copolymer composition is provided comprising:

(a) one or more SBC copolymers;

(b) one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers; and

(c) one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene; rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins, and mixtures thereof; and

wherein one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethacrylate trimethylolpropane (TMPTMA), epoxy acrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate; functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, trimethylolpropane ethoxylated tri-3-mercaptopropionate, as well as other polyfunctional compounds with vinyl or allyl groups, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In another exemplary embodiment, a styrene elastomeric block copolymer composition is provided comprising:

(a) one or more SBC copolymers;

(b) one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers; and

(c) one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, alpha-methylstyrene resin, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, and mixtures thereof; and

wherein one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethacrylate trimethylolpropane (TMPTMA), epoxyacrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate, functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, ethoxylated tri-3-mercaptopropionate trimethylolpropane, as well as other multifunctional compounds with vinyl or allyl groups, and mixtures thereof, while said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol, and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol mol.

In yet another exemplary embodiment, the thin-walled elastic film layers may also contain other adjuvants commonly used in the polymer industry and specifically in the glove industry, such as, for example, lubricants; anti-caking agents; antistatic agents, primary and secondary antioxidants, colorants, processing aids, and so on.

In another exemplary embodiment, a styrene elastomeric block copolymer composition is provided comprising:

(a) one or more SBC copolymers;

(b) one or more polymers miscible with polystyrene end blocks of one or more SBC copolymers; and

(c) one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein one or more SBC copolymers are selected from the group consisting of SIS or SBS, or mixtures thereof;

moreover, at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, alpha-methylstyrene resin, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, and mixtures thereof; and

wherein one or more cross-linking agents are selected from the group consisting of functional thiols, such as 1,8-dimercapto-3,6-dioxaoctane, tris-3-mercaptopropionate of trimethylolpropane, tetrakis-3-mercaptopropionate of pentaerythritol, ethoxylated tri-3-mercaptopropionate trimethylolpropane, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In yet another exemplary embodiment, a process is provided for preparing an SBC copolymer composition comprising the step of combining one or more SBC copolymers, one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers, and one or more crosslinkers capable of providing covalent bonding between the chains of one or more SBC copolymers;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof;

wherein one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof; and

wherein one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethacrylate trimethylolpropane (TMPTMA), epoxyacrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate, functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, ethoxylated tri-3-mercaptopropionate trimethylolpropane, as well as other multifunctional compounds with vinyl or allyl groups, and mixtures thereof.

In another exemplary embodiment, a process is provided for preparing an SBC copolymer composition comprising the step of combining one or more SBC copolymers, one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers, and one or more crosslinkers, capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS or SBC containing reactive functional groups grafted into the middle rubber block, such as, for example, groups carboxyl, amine, alcohol, maleic anhydride; epoxy, isocyanate and aziridine groups, or mixtures thereof;

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene, rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins and mixtures thereof; and

moreover, one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), epoxyacrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate, functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, ethoxylated trimethylolpropane tri-3-mercaptopropionate , as well as other multifunctional compounds with vinyl or allyl groups, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol, and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In yet another exemplary embodiment, a process is provided for preparing an SBC copolymer composition, comprising the step of combining one or more SBC copolymers, one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers; and one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, coumarone-indene resin, polyindene resin, polymethylindene resin, vinyltoluene-alpha-methylstyrene resin, alpha-methylstyrene resin, polyphenylene ether, copolymers of alkylarene monomers such as alpha -methylstyrene and para-methylstyrene; rosin ester, styrene-modified terpenes, polyterpenes, terpene-phenolic resins, and mixtures thereof; and

wherein one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethacrylate trimethylolpropane (TMPTMA), epoxy acrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate; functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, trimethylolpropane ethoxylated tri-3-mercaptopropionate, as well as other polyfunctional compounds with vinyl or allyl groups, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In another exemplary embodiment, a process is provided for preparing an SBC copolymer composition comprising the step of combining one or more SBC copolymers, one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers, and one or more crosslinkers. agents capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, alpha-methylstyrene resin, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, and mixtures thereof; and

moreover, one or more crosslinking agents are selected from the group consisting of aromatic, aliphatic and heteroatomic monomers and oligomers containing at least two carbon-carbon double bonds, such as, for example: multifunctional acrylates such as trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), epoxy acrylates, urethane acrylates, triallyl cyanurate, triallyl isocyanurate; functional thiols such as 1,8-dimercapto-3,6-dioxaoctane, trimethylolpropane tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, trimethylolpropane ethoxylated tri-3-mercaptopropionate, as well as other polyfunctional compounds with vinyl or allyl groups, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In yet another exemplary embodiment, a process is provided for preparing an SBC copolymer composition comprising the step of combining one or more SBC copolymers, one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers; and one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers;

wherein at least one SBC copolymer contains in its elastomeric middle block reactive functional groups, such as double bonds, to allow chemical crosslinking; and

wherein the one or more miscible polymers are selected from the group consisting of polystyrene resin, alpha-methylstyrene resin, copolymers of alkylarene monomers such as alpha-methylstyrene and para-methylstyrene, and mixtures thereof; and

wherein one or more cross-linking agents are selected from the group consisting of functional thiols, such as 1,8-dimercapto-3,6-dioxaoctane, tris-3-mercaptopropionate of trimethylolpropane, tetrakis-3-mercaptopropionate of pentaerythritol, ethoxylated tri-3-mercaptopropionate trimethylolpropane, and mixtures thereof, wherein said SBC copolymers have a molecular weight (Mn) greater than 100,000 g/mol and said miscible polymers have a molecular weight (Mn) less than 10,000 g/mol.

In another exemplary embodiment, a method is provided for making a dipped article from at least one SBC copolymer composition or blend of miscible polymers disclosed in any of the exemplary embodiments described herein, wherein a mold with an outer contour corresponding to the configuration of the article dipped product is immersed for a predetermined period of time in a dipping solution containing one or more SBC copolymer compositions or blends of miscible polymers, and in which the dipped article is then removed from the solution and dried.

Thereafter, this product, in particular the dried product, can be exposed to radiation, such as electron beam, gamma radiation, UV or X-ray radiation.

In another exemplary embodiment, a thin film is provided comprising one or more of the SBC compositions or blends of miscible polymers disclosed in any of the exemplary embodiments described herein, said thin film having a tensile strength measured according to ASTM 3577. , more than 17 MPa, and the specified thin film is essentially insoluble in an organic solvent.

Yet another exemplary embodiment provides a thin film comprising one or more SBC compositions or blends of miscible polymers according to any of the preferred embodiments described herein.

In any of the exemplary embodiments disclosed herein, the thin film may have a thickness of from about 10 microns to about 500 microns, or from about 150 microns to about 250 microns.

In any of the exemplary embodiments disclosed herein, the thin film may have a thickness of less than 500 microns, or less than 400 microns, or less than 300 microns, or less than 200 microns.

In another exemplary embodiment, a manufactured article, such as a glove or condom, is provided, said article comprising one or more of the SBC copolymer compositions or blends of miscible polymers disclosed in any of the exemplary embodiments described herein.

Mechanical properties

SBC copolymer compositions or blends of miscible polymers according to the present disclosure may have a modulus at 100% elongation of less than 1.0 MPa or less than 0.70 MPa.

The thin-walled elastic articles of the present disclosure may have a modulus at 100% elongation of less than 1.0 MPa or less than 0.70 MPa.

The thin-walled elastic products of the present disclosure may have a breaking strength that complies with EN455-2 and ISO10282, i.e. greater than 9 N (when measured on unaged film).

Thin-walled elastic products according to the present disclosure can have a tensile strength that complies with the ASTMD3577 standard, that is, more than 17 MPa (unaged film).

SBC copolymer compositions or blends of miscible polymers or thin-walled elastic articles may have any combination of the mechanical properties disclosed above.

Composition

Compositions in accordance with embodiments of the present disclosure are characterized in terms of PHR (per hundred parts of rubber), wherein the rubber is one or more SBC copolymers. The composition ranges given in the examples include the following:

Miscible polymer: 0.25 - 100 phr, preferably 5 - 50 phr

Plasticizer / Softener: 0 - 200 phr, preferably 20 - 75 phr

Cross-linker: 0.01 - 5 phr, preferably 0.05 - 1 phr

Photoinitiator: 0 - 5 phr, preferably 0 - 2 phr.

Definition and composition

The thin-walled elastic dipped products, such as gloves, more specifically medical gloves, and condoms disclosed herein, may have a thickness in the range of about 10 to about 500 microns, or about 150 microns to about 250 microns.

The dipped articles may comprise a single layer or may be multi-layered.

Multilayer articles may include layers containing the same polymer composition or different polymer compositions.

Examples

In the following examples, intended to illustrate the present disclosure, compositions according to the present disclosure are described. These examples should not be construed as limiting the scope of the present disclosure in any way.

It should be understood that while the present disclosure has been described in connection with specific embodiments, the foregoing description is intended to be illustrative and not limiting of the scope of the disclosure. Other aspects, advantages, and modifications of the invention will be apparent to those skilled in the art to which this disclosure pertains. In view of the foregoing, the examples are set forth to provide those of skill in the art with the most complete disclosure and description of how to make and use the disclosed compositions, and the examples are not intended to limit the scope of the disclosure.

Example 1

The following example demonstrates the improved performance (mechanical properties and chemical resistance) of the composition according to the present disclosure.

Styrene-butadiene-styrene (SBS) copolymer having a viscosity in toluene (10% concentration) of 150 MPa⋅s at 25°C, a miscible polymer based on styrene and substituted styrenes (Mn = 800 g/mol, polydispersity factor = 2.8 ), a white mineral oil plasticizer with a viscosity of 68 MPa⋅s at 40°C, and a crosslinking agent in the form of tris-3-mercaptopropionate trimethylolpropane were dissolved in a mixture of methylcyclohexane and toluene (8:2) to obtain a solution with a solids content of 18 wt. %.

Various amounts of crosslinkers were used as well as miscible polymer (“P”) as shown in the table below.

The amount of plasticizer was 50 phr and 1 phr of polyphenol antioxidant was added to the polymer solution.

The solution was stored at ambient temperature in an appropriate vessel, closed to prevent evaporation of the solvent. The films were made by evaporating the solvent after dipping the porcelain mold into the solution using a part dipping robot at controlled dipping rates. The film was dried at 70° C. for 1 hour before stripping, followed by a final drying at 50° C. for 6 hours to remove trace amounts of residual solvent.

Then the film was exposed to an electron beam with an irradiation dose of 25 ± 2 kGy.

The chemical resistance of the irradiated film was evaluated in various ways. Ideally, the test method should replicate actual exposure to the chemical.

In this example, the SBC copolymer composition is intended for use in the manufacture of gloves, so the following tests were used to evaluate the chemical resistance of the film:

1) swab test: 0.5 g of pure monomeric methyl methacrylate was applied to a cotton swab, which was then placed on a film previously brought to a state of slight tension. The contact time was 10 seconds at low pressure. The test was repeated three times and then the durability of the film was checked.

2) swelling test: a 25 mm disc was cut from the film and placed in a beaker containing 20 ml MEK for 5 minutes with gentle stirring. After 5 minutes, the disk was removed, its outer surfaces were cleaned with a cloth, and the diameter of the disk was measured. The degree of swelling was determined as follows:

100*(diameter after swelling in mm - 25)/25.

Mechanical properties were determined in accordance with ASTM 3577 for surgical gloves. For unaged type II synthetic material, the minimum tensile strength is 17 MPa.

The results are presented in the following table:

Sample Number of stapler (phr) Number P(phr) Tensile strength after exposure to a dose of 25 kGy Swab test %
swelling one 0 0 12.1 The film is cracking Soluble 2 0 ten 16.5 The film is cracking Soluble 3 0.4 ten 18.2 No impact
on film 0% four 0.4 0 8.8 No impact
on film 0%

These results indicate that it is possible to efficiently chemically crosslink SBS films using trimethylolpropane tris-3-mercaptopropionate.

The example indicates that a composition combining an SBC copolymer, a crosslinker and a miscible polymer exhibits better mechanical characteristics than:

- SBC copolymer alone (sample 1)

- SBC copolymer with miscible polymer without crosslinker (sample 2)

- SBC copolymer with a crosslinker without a miscible polymer (sample 4).

Sample 3 also shows significantly improved chemical resistance compared to Samples 1 or 2. Finally, it can be seen that the sample 3 glove is the only sample that passes the ASTM specification for tensile strength. The resulting film is also very soft (modulus at 100% elongation = 0.68 MPa).

Example 2

To replace the SBS copolymer used in samples 1-4, a styrene-isoprene-styrene (SIS) copolymer containing a styrene-isoprene di-block copolymer having a viscosity in toluene (10% concentration) of 45 MPa⋅s at 25°C was used. .

The miscible polymer is based on styrene and substituted styrenes (Mn=800 g/mol, polydispersity factor=2.8), the amount is 20 phr, and no plasticizer or softener is used. The crosslinking agent is trimethylolpropane trimethacrylate, used in an amount of 1 phr.

As in the case of samples 1–4, films were obtained by evaporating the solvent, then they were dried to remove traces of residual solvent before exposure to an electron beam with a radiation dose of 50 ± 3 kGy.

The mechanical characteristic of the film is 17.1 MPa with very high chemical resistance in the tampon test.

Example 3

The multilayer film was produced using the following combinations of polymers:

- the first layer with a thickness of 80±10 μm from the composition of block copolymers of styrene-butadiene-styrene, described above as sample 3;

- a second layer 140±20 µm thick of high molecular weight styrene-ethylene/butylene-styrene (SEBS). Said SEBS copolymer has a radial structure, has a viscosity of 75 centipoise in toluene at 5% concentration, and contains 31% polystyrene. The base of the miscible polymer is styrene and substituted styrenes (Mn=800 g/mol, polydispersity factor=2.8), the amount is 25 phr, and the amount of plasticizer is 60 phr. The crosslinking agent is tris-3-mercaptopropionate of trimethylolpropane in an amount of 0.2 phr.

The multilayer film is exposed to an electron beam with a radiation dose of 40 ± 3 kGy.

Analysis of this film showed a tensile strength of 20.5 MPa with very high tampon resistance.

For brevity, only certain ranges are explicitly disclosed herein.

However, you can combine ranges with any lower limit and any upper limit to specify a range not explicitly listed here, and you can combine ranges with any lower limit and any other lower limit to specify a range not explicitly listed here. explicitly, likewise, ranges can be combined with any upper limit and any other upper limit to give a range not explicitly stated here.

All documents cited are incorporated herein in their entirety by reference to all jurisdictions in which such inclusion is permitted and to the extent that such disclosure is consistent with the description of this disclosure.

Claims (47)

1. An elastomeric styrene block copolymer (SBC) film composition comprising one or more SBC copolymers, one or more polymers miscible with styrene end blocks of one or more SBC copolymers, and one or more crosslinking agents capable of providing covalent bonding between chains of one or more SBC copolymers; where at least one SBC copolymer includes an elastomeric middle block containing carbon-carbon double bonds, and has a molecular weight (Mn) greater than 100,000 g/mol; where these one or more polymers are based on styrene or substituted styrene; wherein the crosslinking agent is selected from the group consisting of multifunctional acrylates; wherein said composition of block copolymers is both physically and chemically crosslinked; where said chemical crosslinking includes covalent bonds between chains of SBC copolymers; where said physical crosslinking includes a non-covalent interaction between the styrenic end blocks of one or more SBC copolymers and one or more polymers miscible with styrene end blocks; and where the specified block copolymer composition includes one or more plasticizers and/or softeners compatible with the elastomeric middle block of one or more SBC copolymers, and the amount of one or more plasticizers and/or softeners is in the range of 20-75 phr. 2. Composition of an elastomeric block copolymer of styrene for films, containing: one or more SBC copolymers; one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers; and one or more crosslinkers capable of providing covalent bonding between chains of one or more SBC copolymers; where at least one SBC copolymer includes an elastomeric middle block containing carbon-carbon double bonds, and has a molecular weight (Mn) greater than 100,000 g/mol; where these one or more polymers are based on styrene or substituted styrene; wherein the crosslinking agent is selected from the group consisting of multifunctional acrylates; and said block copolymer composition includes one or more plasticizers and/or softeners compatible with the elastomeric middle block of one or more SBC copolymers, and the amount of one or more plasticizers and/or softeners is in the range of 20-75 phr. 3. A method for producing an SBC copolymer composition for producing films, comprising the following step: combining one or more SBC copolymers, one or more polymers miscible with one or more polystyrene end blocks of one or more SBC copolymers; and one or more crosslinking agents capable of providing covalent bonding between the chains of one or more SBC copolymers, where one or more SBC copolymers include an elastomeric middle block containing carbon-carbon double bonds and have a molecular weight (Mn) greater than 100,000 g/mol; said one or more polymers are based on styrene or substituted styrene; the crosslinking agent is selected from the group consisting of multifunctional acrylates; and said block copolymer composition includes one or more plasticizers and/or softeners compatible with the elastomeric middle block of one or more SBC copolymers, and the amount of one or more plasticizers and/or softeners is in the range of 20-75 phr. 4. The composition according to any one of paragraphs. 1 or 2, or the method of claim 3, wherein the one or more SBC copolymers independently comprise a fully unsaturated or partially unsaturated elastomeric midblock. 5. The composition according to any one of paragraphs. 1, 2 or 4 or the method according to any one of paragraphs. 3, 4, in which one or more SBC copolymers are selected from the group consisting of SIS, SBS, SIBS, S-isobutylene-S, SEBS, SEPS, SEEPS, or SBC copolymers containing reactive functional groups grafted into the middle rubber block, such such as carboxyl, amine, alcohol, maleic anhydride groups; epoxy, isocyanate and aziridine groups and mixtures thereof. 6. Composition according to any one of paragraphs. 1, 2, 4, 5 or the method according to any one of paragraphs. 3-5, in which the number average molecular weight of the miscible polymer (Mn) is less than 10000 g/mol, and more preferably less than 3000 g/mol. 7. The composition according to any one of paragraphs. 1, 2, 4-6 or the method according to any one of paragraphs. 3-6, in which the miscible polymer has a molecular weight polydispersity factor in the range of 2.0 to 3.0. 8. The composition according to any one of paragraphs. 1, 2, 4-7 or the method according to any one of paragraphs. 3-7, wherein the miscible polymer is selected from the group consisting of polystyrene resin, vinyltoluene alpha-methylstyrene resin, alpha-methylstyrene resin, alpha-methylstyrene-p-methylstyrene copolymers, styrene-modified terpenes, and mixtures thereof. 9. The composition according to any one of paragraphs. 1, 2, 4-8 or the method according to any one of paragraphs. 3-8, in which one or more miscible polymers are selected from the group consisting of polystyrene resin, vinyl toluene-alpha-methylstyrene resin, alpha-methylstyrene resin, alpha-methylstyrene-p-methylstyrene copolymers, styrene-modified terpenes, and mixtures thereof, wherein said miscible polymers have a molecular weight (Mn) of less than 10,000 g/mol. 10. The composition according to any one of paragraphs. 1, 2, 4-9 or the method according to any one of paragraphs. 3-9, wherein the crosslinker is selected from the group consisting of trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), epoxy acrylates, urethane acrylates, and mixtures thereof. 11. Composition according to any one of paragraphs. 1, 2, 4-9 or the method according to any one of paragraphs. 3-9, wherein the crosslinker is a metal salt, an amine crosslinker selected from the group consisting of an organic amine, an organic diamine, and an organic polyamine, or a polyol. 12. The method according to any one of paragraphs. 3-11 wherein the composition is crosslinked using radiation, such as UV, electron beam, gamma or X-ray radiation. 13. The method according to any one of paragraphs. 3-11, in which the crosslinking reaction is initiated or accelerated using one radical-type photoinitiator or a mixture thereof. 14. The method of claim 13, wherein the crosslinking photoinitiators are selected from the group consisting of acylphosphine oxides, e.g., monoacylphosphine oxides, bis-acylphosphine oxides, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, or other substances such as phenylpropanone, methylbenzoyl formate and phenylglyoxylic acid methyl ester. 15. The composition according to any one of paragraphs. 1, 2, 4-11 or the method according to any one of paragraphs. 3-14, in which the plasticizer contains a liquid saturated polyolefin or a mixture of liquid saturated polyolefins compatible with the middle block (elastomer block) of the SBC copolymer. 16. The composition according to any one of paragraphs. 1, 2, 4-11 or 15 or the method according to any one of paragraphs. 3-15, in which the plasticizer contains plasticizing oils, preferably mineral plasticizing oils and more specifically mineral oils obtained from a purified mixture of liquid saturated hydrocarbons formed by compounds of a paraffinic or naphthenic nature or mixtures thereof. 17. The composition according to any one of paragraphs. 1, 2, 4-11, 15, 16 or the method according to any one of paragraphs. 3-16, in which the softener is selected from polybutadiene, polyisoprene, polyisobutene, amorphous polyolefin copolymers of propylene and ethylene, butyl rubber and other elastomers known to have sufficient compatibility with the elastomeric block. 18. Composition according to any one of paragraphs. 1, 2, 4-11 or 15-17 or the method according to any one of paragraphs. 3-17, further including other adjuvants commonly used in the polymer industry and specifically in the manufacture of gloves, such as, for example, lubricants, antistatic agents, primary and secondary antioxidants, coloring agents or processing aids. 19. A method of manufacturing a product obtained by dipping from at least one SBC copolymer composition according to any one of paragraphs. 1, 2, 4-11, or 15-18, wherein a mold with an outer contour corresponding to the configuration of the dipped article is immersed for a predetermined period of time in a dipping solution containing one or more SBC copolymer compositions, and in which the article, obtained by dipping, then removed from the solution and dried. 20. The method of claim 19, further comprising exposing the dried article to radiation, preferably an electron beam. 21. A thin film comprising one or more compositions of SBC copolymers according to any one of paragraphs. 1, 2, 4-11 or 15-18, wherein said thin film has an ASTM 3577 tensile strength greater than 17 MPa, and wherein said thin film is substantially insoluble in an organic solvent. 22. Thin film according to claim 21, having a thickness of 10 to 500 microns. 23. Thin film according to claim 21 or 22, wherein at least 80% of the thin film is insoluble or at least 95% of the film is insoluble in the organic solvent. 24. A thin film comprising one or more compositions of SBC copolymers according to any one of paragraphs. 1, 2, 4-11 or 15-18. 25. Thin film according to claim 24, having a thickness of 10 to 500 microns. 26. Thin film according to claim 24, having a thickness of 150 to 250 microns. 27. Thin film according to any one of paragraphs. 24-26 having an ASTM 3577 tensile strength greater than 17 MPa, wherein said thin film is substantially insoluble in an organic solvent. 28. Multilayer film comprising one or more layers, where said one or more layers contain compositions of SBC copolymers according to any one of paragraphs. 1, 2, 4-11 or 15-18. 29. Multilayer film comprising one or more layers, where said one or more layers contain compositions of SBC copolymers according to any one of paragraphs. 1, 2, 4-11 or 15-18, wherein said composition has a tensile strength of at least 17 MPa and said composition is essentially insoluble in an organic solvent. 30. Multilayer film, including several thin films according to any one of paragraphs. 21-27. 31. Multilayer film according to any one of paragraphs. 28-30 wherein at least one layer is selected from the group consisting of natural rubber, polybutadiene, polyisoprene, polychloroprene, butyl rubber, polyurethane, acrylic polymers and copolymers, silicone elastomers, other SBC copolymers, cyclic block copolymers (CBC), and their mixtures. 32. Manufactured product, comprising one or more compositions of SBC copolymers according to any one of paragraphs. 1, 2, 4-11, or 15-18 where the article is a medical device such as a medical glove, condom, or personal protective equipment such as lab or cleaning gloves.