Patent Description:
Elastomeric materials are widely used in a variety of applications, such as adhesives, sealants, coatings, tires, the automotive industry, construction industry, electrical and electronic industry, and medical applications. The desirable properties include, e.g., good mechanical performance, low viscosity and reactivity. In medical applications, some uses require materials with flow and good strength during production, in addition to better elasticity and resistance to leaching/bleed out or extractability during sterilization in the final application. Good mechanical performance in term of strength, elasticity, e.g., a low compression set, and weather resistance or ozone resistance are also desirable. Existing thermoplastic materials may not be able to meet such requirements. <CIT> relates to a thermoplastic elastomer (TPE) composition, a plug, and a container for medical use. The TPE composition comprising a hydrogenated block copolymer (a), a polypropylene-based resin (b), a non-aromatic softener (d) and other additives (e). The hydrogenated block copolymer (a) contains at least one hydrogenated block copolymer (a-<NUM>), and a hydrogenated block copolymer (a-<NUM>). The hydrogenated block copolymers a-<NUM> and a-<NUM> comprises at least <NUM> vinyl aromatic hydrocarbon monomer unit and at least <NUM> conjugated diene monomer unit. The weight average molecular weight of a-<NUM>, and a- <NUM> is <NUM>,<NUM> to <NUM>,<NUM>/mol and <NUM>,<NUM> to <NUM>,<NUM>/mol respectively. The vinyl aromatic hydrocarbon monomer units' content of a-<NUM> is more than <NUM> mass% to <NUM> mass % or less, whereas it is <NUM> to <NUM> mass % in a-<NUM>. The mass ratio of a-<NUM>/a-<NUM> is <NUM>/<NUM> to <NUM>/<NUM>. <CIT>relates to a thermoplastic elastomer (TPE) composition, which contains a blend of a hydrogenated styrenic block copolymer (SBC) having a number average molecular weight (Mn) greater than about <NUM>,<NUM> Daltons (Da), a polypropylene, a mineral oil, and at least one filler. The composition has a hardness less than about <NUM> Shore A and is resealable. The hydrogenated styrenic block copolymer is selected from the group consisting of a SEBS (styrene-ethylene-butylene-styrene) block copolymer, a SIPS (styrene-isoprene-styrene) block copolymer, and a SEEPS (styrene-ethylene-(ethylene-propylene)-styrene) block copolymer. The TPE composition can be used in penetrable articles such as seals, gaskets, septa, caps for bottles, plugs and medical devices. <CIT> relates to a tube in the form of a molded article of a resin composition including a hydrogenated block copolymer (a) and a hydrogenated block copolymer (b) and a polyolefin-based resin (c). The hydrogenated block copolymer (a) is in triblock form with A1-B-A2 type structure. Each A1 and A2 polymer blocks constituted mainly from an aromatic vinyl compound unit, and a polymer block (B) constituted mainly conjugated having a glass transition temperature of from -<NUM> to <NUM>0C. Whereas hydrogenated block copolymer (b) constituted by aromatic vinyl aromatic units (C) and conjugated dine units (D) having a glass transition temperature of less than -<NUM>0C. The molded article suitable for medical devices. <CIT> relates to a new hydrogenated styrenic block copolymer, in particular styrene-ethylene/butylene-styrene copolymers (SEBS copolymers), with improved performance in thermoplastic elastomer compositions (TPE-S). The thermoplastics elastomer composition comprises: - a) at least one hydrogenated styrenic block copolymer of the invention; - b) at least a thermoplastic resin; and - c) at least a plasticizer agent. The hydrogenated styrenic block copolymer has a radial structure, having a vinyl content of at least <NUM>%, and a molecular weight between <NUM>,<NUM> and <NUM>,<NUM>/mol and a Brookfield viscosity at <NUM>% by weight in toluene, of less than <NUM> cps. TPE-S composition, in particular, suitable for medical applications. <CIT> relates to an article of manufacture, comprising: a container comprising a content, and a stopper for said container, wherein: said content comprises a medical drug or an infusion solution, and said stopper comprises a thermoplastic elastomer composition, the thermoplastic elastomer composition comprising: (<NUM>) <NUM> parts by mass of (a) a hydrogenated block copolymer that is the hydrogenated product of a block copolymer comprising (A) a polymer block comprising a structural unit derived from an aromatic vinyl compound and (B) a polymer block comprising a structural unit derived from isoprene and having a total content of <NUM>,<NUM>-bond units and <NUM>,<NUM>-bond units of <NUM>% or more, wherein the hydrogenated block copolymer (a) has a peak top molecular weight (Mp) obtained by gel permeation chromatograph in terms of polystyrene standard of from <NUM>,<NUM> to <NUM>,<NUM>, and is in a form of powder having a bulk density of from <NUM> to <NUM>/mL; (II) <NUM> to <NUM> parts by mass of (b) a softening agent, based on <NUM> parts by mass of the hydrogenated block copolymer (a); and (III) <NUM> to <NUM> parts by mass of (c) a polyolefin resin, based on <NUM> parts by mass of the hydrogenated block copolymer (a), wherein said composition comprises essentially no crosslinking agent.

There is a need for polymeric compositions exhibiting thermoplastic flow properties, in addition to very low leaching and good mechanical properties.

In one embodiment, a composition is disclosed. The composition comprises, consists essentially of, or consists of: components (a), (b), wherein component (a) is a selectively hydrogenated block copolymer comprising one or more structures A-B-A, (A-B-A)nX, A-(B-A)n, and (A-B)nX. Component (b) is a selectively hydrogenated block copolymer comprising one or more structures C-D, D-C-D, and (D-C-)nX; In the formulas, "n" is <NUM> - <NUM>, and "X" is a residue of a coupling agent. Before hydrogenation, A is a polymer block of a vinyl aromatic monomer, having a peak molecular weight (Mp) of <NUM> - <NUM>/mol, B is a polymer block comprising <NUM> - <NUM> mol% of one or more conjugated dienes, and <NUM> - <NUM> mol% of a vinyl aromatic monomer; C is a polymer block of a vinyl aromatic monomer, having a peak molecular weight of <NUM> - <NUM>/mol; D is a polymer block comprising <NUM> - <NUM> mol% of one or more conjugated dienes, and <NUM>-<NUM> mol% of a vinyl aromatic monomer; After hydrogenation, from more than <NUM> to <NUM> mol% of the polymerized diene units, and from <NUM>-<NUM> mol% of the polymerized vinyl aromatic monomer units in the polymer blocks A, B, C and D are reduced. The vinyl aromatic monomers of the polymer blocks A, B, C and D are independently same or different; and the conjugated diene monomers for the polymer blocks B and D are independently same or different. The block copolymer (a) has a peak molecular weight of from <NUM> - <NUM>,<NUM>/mol and the block copolymer (b) has a peak molecular weight of from <NUM> - <NUM>/mol, The overall block copolymer composition has a compression set, after <NUM> at <NUM> of less than <NUM> percent, measured according to ASTM D395.

Another aspect of the disclosure is a blend comprising the above block copolymer composition and a semi-crystalline polyolefin.

Other aspects of the disclosure include molding compositions and articles made using the above block copolymer composition.

The following terms will have the following meanings:
"Molecular weight" or MW refers to the styrene equivalent molecular weight in kg/mol of a polymer block or a block copolymer. The molecular weights can be measured with gel permeation chromatography (GPC) using polystyrene calibration standards according to ASTM <NUM>-<NUM>. The chromatograph can be calibrated using commercially available polystyrene molecular weight standards. The MW so calibrated are styrene equivalent molecular weights. The detector can be a combination ultraviolet and refractive index detector. The MW expressed herein are measured at the peak of the GPC trace, and are commonly referred to as "peak molecular weight" (Mp). Unless otherwise specified, MW refers to the styrene equivalent peak molecular weights Mp.

"Corrected <NUM>,<NUM>-diene unit content", "C14DUC", in a polymer block having repeat units derived from butadiene (Bd), and isoprene, myrcene, farnesene, or any other conjugated diene (Ip), or combinations thereof, is mathematically given in terms of the parameters: wt. % Bd content (Bw) in the total dienes in the polymer block, wt. % of <NUM>,<NUM>-addition units of Bd (B14) in the polymer block, wt. % Ip content (Iw) in the total dienes in the polymer block, and wt. % of <NUM>,<NUM>-addition units of Ip (<NUM>) in the polymer block, by equation (<NUM>): <MAT>.

Polymerization of a conjugated diene gives rise to polymerized units that are based on addition across both double bonds (giving rise to <NUM>,<NUM>-addition units) as well as one double bond (giving rise to vinyl groups).

"Polystyrene content" of a block copolymer refers to the % weight of polymerized styrene or a vinyl aromatic monomer in the block copolymer, calculated by dividing the sum of molecular weight of all polystyrene or polymerized vinyl aromatic units by the total molecular weight of the block copolymer. Polystyrene content can be determined using any suitable methodology such as proton NMR.

"Oil free" refers to a composition with < <NUM> wt. %, or < <NUM> wt. %, or < <NUM> wt. %, paraffinic oil present based on the total weight of the composition. Similarly, phthalate-free compositions refer to composition wherein phthalate is not added, with < <NUM> wt. %, or < <NUM> wt. %, or < <NUM> wt. % phthalate present.

"HSBC" refers to a selectively hydrogenated styrenic block copolymer. The hydrogenated styrenic block copolymer is based on copolymerized conjugated diene and styrenic monomers and in which a significant fraction of the double bonds resulting from the conjugated diene units have been reduced or hydrogenated, with "selectively" meaning the conjugated bond fully (e.g., > <NUM>%, or > <NUM>%) hydrogenated and the aromatic bond being a lot less hydrogenated (e.g., <NUM> to <NUM>%).

The disclosure relates to HSBC compositions and the blends thereof, in embodiments, a hydrogenated block copolymer with a triblock and a short diblock, for use in oil-free / phthalate-free thermoplastic elastomer ("TPE") blends exhibiting thermoplastic flow properties, in addition to excellent mechanical properties, e.g., improved elasticity and resistance to extraction after sterilization, suitable for applications including medical.

HSBC Composition: The composition comprises components (a) and (b, where each component encompasses different types of block copolymers. The vinyl aromatic monomer repeat units in the polymer blocks A, B, C and D can be independently the same or different. Likewise, the conjugated diene monomer repeat units in the polymer blocks B and D can be independently the same or different. Each of the components (a) and (b) are described below in detail.

Component (a): The overall composition comprises components (a) and (b), where each component encompasses different types of block copolymers. The vinyl aromatic monomer repeat units in the polymer blocks A, B, C and D can be independently the same or different. Likewise, the conjugated diene monomer repeat units in the polymer blocks B and D can be independently the same or different. Each of the components are described below in detail. In embodiments, the components (a) and (b) are in a weight ratio of from <NUM>:<NUM> to <NUM>:<NUM>, or from <NUM>:<NUM> to <NUM>:<NUM>, or from <NUM>:<NUM> to <NUM>:<NUM>.

Component (a) is a selectively hydrogenated block copolymer comprising one or more structures A-B-A, (A-B-A)nX, A-(B-A)n, and (A-B)nX, where A is a polymer block, also termed a "rigid block", having repeat units of a vinyl aromatic monomer, B is a polymer block having repeat units of a conjugated diene and optionally a vinyl aromatic monomer, "n" is from <NUM> - <NUM>, and X is a residue of a coupling agent.

In embodiments, the component (a) block copolymer can have a Mp of from <NUM> - <NUM>/mol, or > <NUM>/mol, or <NUM> - <NUM>/mol, or from <NUM> - <NUM>/mol.

In embodiments, prior to hydrogenation, the block "A" can have a Mp of <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol.

In embodiments, the block "B", prior to hydrogenation, can have a Mp of <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol.

In embodiments, the polymer block "A" can form from <NUM> to <NUM> wt. %, or from <NUM> to <NUM> wt. %, or from <NUM> to <NUM> wt. % of the selectively hydrogenated block copolymer component (a).

In embodiments, the block "B" can comprise <NUM> - <NUM> mol% of one or more conjugated dienes, and <NUM>-<NUM> mol% of a vinyl aromatic monomer; or <NUM> - <NUM> mol% of one or more conjugated dienes, and <NUM>-<NUM> mol% of a vinyl aromatic monomer; or > <NUM> mol% of one or more conjugated dienes and < <NUM> mol% of a vinyl aromatic monomer; or <NUM>% of one or more conjugated dienes and no vinyl aromatic monomer.

In embodiments, the block "B" can comprise <NUM> mol% of butadiene or isoprene, or combinations thereof, and no vinyl aromatic monomer. In yet another embodiment, the block "B" can comprise <NUM> mol% of butadiene, and no vinyl aromatic monomer.

After hydrogenation, in an embodiment, from <NUM>-<NUM> mol%, or > <NUM> mol%, or > <NUM> mol%, or <NUM>-<NUM> mol% or <NUM>-<NUM> mol% of the polymerized diene units in the block B, and from <NUM> - <NUM> mol%, or ><NUM> mol%, or <NUM>-<NUM> mol%, or < <NUM> mol% or <NUM>-<NUM> mol% of the polymerized vinyl aromatic monomer units in the blocks A and B are reduced.

In embodiments, after hydrogenation, from <NUM>-<NUM> mol%, or <NUM> - <NUM> mol%, or > <NUM> mol%, or > <NUM>% of the polymerized diene units in the block B, and from <NUM>-<NUM> mol%, or from <NUM> - <NUM> mol% of the polymerized vinyl aromatic monomer units in the blocks A and B are reduced.

In still other embodiments, after hydrogenation, from <NUM> - <NUM> mol%, or <NUM>-<NUM> mol%, or < <NUM> mol%, or > <NUM> mol% of the polymerized vinyl aromatic monomer units in the blocks "A" and "B" are reduced, and from more than <NUM> to <NUM> mol%, or <NUM> to <NUM> mole%, or > <NUM> mol% of the polymerized diene units in the "B" block are reduced.

The vinyl aromatic compound used for building the polymer block "A" can be any aromatic compound having a vinyl group attached thereto. Non-limiting classes of compounds suitable for use include styrene and substituted styrenes, vinyl naphthalene and substituted vinyl naphthalenes, vinyl indenes, vinyl anthracenes, and <NUM>,<NUM>-diphenyl ethylene. Some specific examples include vinyl aromatic compounds having <NUM>-<NUM> carbon atoms, such as o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, <NUM>,<NUM>-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene and vinylxylene, or mixtures thereof. In embodiments, the vinyl aromatic compound can be styrene.

The polymer block B (also termed "rubber block") can contain from <NUM>-<NUM> mol% or <NUM>-<NUM> mol%, or > <NUM> mol% or <NUM>% of repeat units derived from a conjugated diene, and <NUM>-<NUM> mol%, or > <NUM> mol%, or <NUM> -<NUM> mol%, or < <NUM> mol% or <NUM>% of repeat units derived from a vinyl aromatic monomer. Any conjugated diene can be used. In an embodiment, the conjugated diene has from four to eight carbon atoms. In another embodiment, the conjugated diene is selected from the group consisting of <NUM>,<NUM>-butadiene, isoprene, myrcene, farnesene, <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-butadiene, <NUM>,<NUM>-pentadiene, <NUM>,<NUM>-hexadiene, and combinations thereof.

Component (b): Component (b) is one or more of a selectively hydrogenated block copolymer comprising one or more structures C-D, D-C-D, and (D-C-)nX; where "C" is a polymer block having repeat units derived from a vinyl aromatic compound, "D" is a polymer block having repeat units of one or more conjugated dienes, and optionally a vinyl aromatic monomer, "n" is from <NUM> - <NUM>, and X is a residue of a coupling agent.

In embodiments, the component (b) block copolymer has a Mp of <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol, or < <NUM>/mol or <<NUM>/mol.

In embodiments, the block "C" has a Mp of <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol or <NUM> - <NUM>/mol.

In embodiments, the block "D" has a Mp of <NUM> - <NUM>/mol, or <NUM> - <NUM>/mol.

In embodiments, the block "D" comprises <NUM> - <NUM> mol% of a conjugated diene, and <NUM>-<NUM> mol% of a vinyl aromatic monomer; or <NUM> - <NUM> mol% of a conjugated diene, and <NUM>-<NUM> mol% of a vinyl aromatic monomer; or > <NUM> mol% of a conjugated diene and < <NUM> mol% of a vinyl aromatic monomer; or essentially <NUM>% mol of one or more conjugated dienes and very little if any vinyl aromatic monomer.

In embodiments, the block "D" comprises ~ <NUM> mol% of butadiene or isoprene, or combinations thereof, and very little if any vinyl aromatic monomer.

After hydrogenation, in embodiments, from <NUM>-<NUM> mol% of the polymerized vinyl aromatic monomer units in the block C are reduced, and from > <NUM> to <NUM> mol% of the polymerized diene units, and from <NUM>-<NUM> mol% of the polymerized vinyl aromatic monomer units in the block D are reduced.

In embodiments, after hydrogenation, from <NUM>-<NUM> mol%, or <NUM> - <NUM> mol% of the polymerized diene units in the block D, and from <NUM>-<NUM> mol%, or from <NUM> - <NUM> mol% of the polymerized vinyl aromatic monomer units in the blocks C and D are reduced.

In embodiments, after hydrogenation, <NUM> - <NUM> mol% of the polymerized vinyl aromatic monomer units in the blocks "C" and "D" are reduced, and > <NUM> to <NUM> mol%, or <NUM> to <NUM> mole% of the polymerized diene units in the "D" block are reduced.

The vinyl aromatic compound used for building the polymer block "C", and the vinyl aromatic compound and conjugated diene used for building the block "D" can be any of the examples discussed previously for the block copolymer component (a).

In embodiments, the polymer blocks "A" and "B" in the component (a) comprise polymerized vinyl aromatic monomer units derived from the same vinyl aromatic monomer, wherein the vinyl aromatic monomer units is selected from styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, <NUM>,<NUM>-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene, vinylxylene, and combinations thereof.

In embodiments, the polymer blocks "C" and "D" in the component (b) can comprise polymerized vinyl aromatic monomer units derived from the same vinyl aromatic monomer, wherein the vinyl aromatic monomer units is selected from styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, <NUM>,<NUM>-dimethylstyrene, alpha-methylstyrene, vinylnaphthalene, vinyltoluene, vinylxylene, and combinations thereof.

In embodiments, the "Corrected <NUM>,<NUM>-diene unit content" in the polymerized diene units in the blocks B and D, before hydrogenation, can independently vary over a range from <NUM> - <NUM> wt. %, or <NUM>-<NUM> wt. %, or <NUM>-<NUM> wt. %, or <NUM>-<NUM> wt. %, or <NUM>-<NUM>%, or <NUM>-<NUM>%. The <NUM>,<NUM>-diene unit content can be varied by using certain additives (explained below) during the polymerization of the conjugated diene.

In embodiments, the polymer blocks B and D are composed of the same diene unit or same combination of diene units, with Corrected <NUM>,<NUM>-diene unit content before hydrogenation not differing more than <NUM> wt. % from each other.

Preparation of the HSBC Composition: The components (a) and (b) of the HSBC composition can be prepared by anionic polymerization using techniques known in the art, forming a precursor block copolymer. The polymerization initiator is generally an organometallic compound, such as organolithium compounds, example, ethyl-, propyl-, isopropyl-, n-butyl-, sec-butyl-, tert-butyl-, phenyl-, hexylbiphenyl-, hexamethylenedi-, butadieneyl-, isopreneyl-, <NUM>,<NUM>-diphenylhexyllithium, or polystyryllithium. The amount of initiator needed is calculated based on the molecular weight to be achieved, generally from <NUM> to <NUM> mol percent, based on the amount of monomer to be polymerized. Suitable solvents for the polymerization include aliphatic, cycloaliphatic or aromatic hydrocarbons having from <NUM> to <NUM> carbon atoms, such as pentane, hexane, heptane, cyclopentane, cyclohexane, methylcyclohexane, decalin, isooctane, benzene, alkylbenzenes, such as toluene, xylene or ethylbenzene, or suitable mixtures.

Polymer chain termination is carried out using a carbanion quenching agent, e.g., an organic alcohol coupling agent, such as bi- or polyfunctional compounds, e.g., divinylbenzene, halides of aliphatic or araliphatic hydrocarbons, such as <NUM>,<NUM>-dibromoethane, bis(chloromethyl)benzene, or silicon tetrachloride, dialkyl- or diarylsilicon dichloride, alkyl- or arylsilicon trichloride, tin tetrachloride, alkylsilicon methoxides, alkyl silicon ethoxides, polyfunctional aldehydes, such as terephthalic dialdehyde, ketones, esters, anhydrides or epoxides. In embodiments with coupling, the coupling agent is selected from the group consisting of methyltrimethoxysilane (MTMS), tetramethoxysilane (TMOS), divinylbenzene (DVB), and dimethyladipate (DMA).

If desired, a Lewis base additive, which affects polymerization parameters can be employed. Examples of Lewis bases include dimethyl ether, diethyl ether, ethylene glycol dimethyl ether, <NUM>,<NUM>-diethoxypropane, diethylene glycol dimethyl ether, tetrahydrofuran, tetrahydrofurfuryl ethers, such as tetrahydrofurfuryl methyl ether, and tertiary amines.

Hydrogenation of the polymer precursor provides the HSBCs under conditions to achieve the appropriate levels of hydrogenation in the polymer blocks A - D. A suitable catalyst based on nickel, cobalt or titanium can be used in the hydrogenation step.

The components (a) and (b) can be mixed in solvent or in molten state to form the HSBC composition. The components (b) is preferable mixed into a component (a) in solvent.

Properties of the HSBC Composition: The HSBC compositions exhibit elastomeric performance and good mechanical performance. They also have excellent resistance to leaching. They also show good elasticity, e.g., a low compression set. In embodiments, the block copolymer compositions have a compressions set of < <NUM>%, or < <NUM>%, or < <NUM>% measured after <NUM> hours of compression at <NUM> according to ASTM D395.

In embodiments, the HSBC composition has good processability as measured by apparent viscosity with Capillary Rheometry at <NUM> of < <NUM> Pa. s, or < <NUM> Pa. or <NUM> - <NUM> Pa.

In embodiments, the HSBC composition shows a low level of extractables of < <NUM>%, or < <NUM>%, or < <NUM>%, measured by degree of absorbance of light at wavelengths of <NUM> - <NUM>, after treatment according to standard YBB00042005.

Blends Based on the HSBC Compositions: The HSBC compositions can be used for preparing blends for various end-use applications, e.g., blended with polymers that are not extractable by hydrocarbon based or water-based solvents.

In embodiments, the polymer for the blends is selected from the group of polystyrene, a polyolefin, such as polypropylene, polyethylene and blends thereof; a thermoplastic elastomer, such as a thermoplastic polyurethane or thermoplastic copolyester; an aromatic polyether resin, or combinations thereof. Suitable polyolefins include a crystalline thermoplastic polymer containing > <NUM> wt. % of the total weight of the polymer, of polymerized ethylene units. Other suitable plastics include polyamides, copolymers of styrene with comonomers such as acrylonitrile and methacrylates, or mixtures.

In embodiments, the blend comprises <NUM> parts by weight of the HSBC composition and <NUM> to <NUM> parts, or <NUM> - <NUM> parts, or <NUM> - <NUM> parts, or <NUM> - <NUM> parts, or <NUM> - <NUM> parts, or <NUM> - <NUM> parts by weight of a semi-crystalline polyolefin; wherein the semicrystalline polyolefin is selected from the group of a homopolypropylene, a propylene copolymer, and combinations thereof, with the semi-crystalline polyolefin having a melting point of ><NUM>.

The semi-crystalline propylene copolymer can have repeat units derived from at least one comonomer selected from the group consisting of ethylene and at least one C4 to C20 α-olefin, preferably having an average propylene content of > <NUM> mol%, or > <NUM> mol%, or > <NUM> mol%. The polypropylene homopolymers preferably have > <NUM>%, or > <NUM>% or more heptane insolubles. The insoluble content can be measured, e.g., by drying a bulk sample at <NUM> in a vacuum oven and then boiling in n-heptane for <NUM> hours. Thereafter samples are vacuum dried, rinsed with acetone and dried in a vacuum oven at <NUM>. The heptane insoluble content in % is given by: <NUM> X (weight of sample after boiling and drying in vacuum) divided by weight of the sample prior to combining with n-heptane.

The polypropylene copolymer can have a melt flow rate (MFR) as measured according to ASTM D <NUM>(B) with <NUM> and <NUM> of <NUM> - <NUM> dg/min, or <NUM> - <NUM> dg/min, or <NUM> - <NUM> dg/min, or <NUM> - <NUM> dg/min. The crystallinity in the propylene copolymer can be derived from the domains having either the isotactic sequences, or the syndiotactic sequences. Examples of the semi-crystalline polypropylene include a random copolymer of ethylene and propylene, having a melting point by Differential Scanning Calorimetry (DSC) analysis (ASTM E-<NUM>-<NUM>) in a range of <NUM> - <NUM>, or <NUM> - <NUM>, or <NUM> - <NUM>.

In embodiments, the blend further comprises up to <NUM> parts by weight, per <NUM> parts of the blend, of one or more additives, e.g., a polyphenylene ether, an inorganic or organic filler, carbon black, flame retardants, antioxidants, UV stabilizers, dyes, and surface agents.

Preparation of TPE Blend Based on HSBC Compositions: The HSBC compositions can be blended with other components using a suitable device such as a Henschel mixer, a V blender, a ribbon blender, etc. The final blend can be obtained by mixing the ingredients or pre-blended ingredients in a single screw or twin screw extruder, a kneader, or the like. The resultant mixed and molten blend can also be pelletized.

Properties of the TPE Blend: In embodiments, the TPE blends are characterized as being oil free and phthalate free with the HSBC composition having a short diblock, obviating the need for additives such as paraffinic oil and / or phthalate. The TPE blends are characterized as having good elastomeric and flow properties. They also have excellent resistance to leaching, and show good mechanical performance in term of strength, and elasticity, e.g., a low compression set. In embodiments, the TPE blend has a compressions set of < <NUM>% or < <NUM>%, or < <NUM>%, or <NUM> - <NUM>%, or <NUM>-<NUM>%, or <NUM>-<NUM>%, measured after <NUM> hours of compression at <NUM> according to ASTM D395.

In embodiments, the TPE blend has a low level of extractables of < <NUM>%, or < <NUM>%, or < <NUM>%, measured by the degree of absorbance of light between the wavelengths of <NUM> and <NUM>, after treatment according to YBB00042005.

To enable melt-processing the apparent viscosity of the TPE blends is < <NUM> Pa. s, or < <NUM> Pa. or preferably between <NUM> Pa. s and <NUM> Pa. measured via capillary rheometry at a shear rate of <NUM> /s at <NUM>.

Uses of the blends: The TPE blends / compounds can be processed into sheets, molded articles, profile extrusions, and films, into articles using known techniques, e.g., foaming (for foamed articles), coating, injection molding, extrusion, co-extrusion, blow molding, hot melt spraying, laminating with other materials, compression molding, and solution spraying to provide articles.

The compositions can be used for making a variety of articles, particularly those used in the medical field such as medical bags, medical tubes, or medicine bottle stoppers, medical containers and caps, multi-lumen tubes, multi-layer tubes, and sterilizable articles, IV bags, catheters and catheters such as those used for infusion, blood transfusion, peritoneal dialysis, and catheter intervention, such as intravascular catheters and balloon catheters, blood bags, synthetic vascular prostheses, vascular circuits, syringes, hemodialyzers, blood cell separators, extracorporeal membrane oxygenation, dressing materials, and medical devices that are brought into contact with body fluids, etc. Tubes can be made with no particular limitation on the size, shape or cross-section size, using an extruder and forcing melted blend through a die to form a tube, and cooling with water / air.

The compositions can also be used for making articles having applications in automotive or transportation, tires, sealants, adhesives, damping layers in films, buildings, construction, shoes, industrial equipment, healthcare, medical devices, sport equipment, grips, prosthetic components, and bullet-proof equipment.

Hardness shore A with <NUM> second dwell time is measured on a <NUM> thick mm plate according to ASTM D2240.

Melt flow rates (MFR) are measured according to ASTM D1238 under <NUM> load and at <NUM>.

Compression set is measured by ASTM D395 Method B. The sample is compressed <NUM>%, otherwise specified for a specified time at a specified temperature as given in the table-<NUM>. Compression set is taken as the percentage of the non-recovered deflection after the material is allowed to recover at standard conditions for <NUM> minutes. Test pieces: diameter <NUM>, thickness <NUM> for compression molded samples and <NUM> for injection molded samples.

Sterilization is carried out at <NUM> <NUM>C for <NUM> minutes in an autoclave.

Bleed out during compression set measurement is carried out by placing a piece of absorption paper under the test pieces during the compression tests. Visual inspection after the tests will show bleeding (seen from discoloring of the paper) or no bleeding of the polymer compounds or neat polymers.

Tensile strength, modulus at <NUM>% elongation, and elongation at break are measured according to ISO-<NUM>, with distance between clamps: <NUM>; distance between extensiometers: <NUM>; pre-load before testing <NUM>. 5N, speed up to pre-load <NUM>/min, test speed <NUM>/min. Testing_is carried out in a conditioned room at <NUM> and a relative humidity of <NUM>%.

Extractables are determined according to standard YBB00042005.

Capillary Rheometry viscosity is measured at <NUM> for HSBC composition and at <NUM> for TPE blends, at applied shear rate of <NUM> /s, a die diameter of <NUM> and die length of <NUM>, as apparent viscosity in Pa.

UV absorbance measurement against TPE blends is carried out by filtering the test solution with a <NUM> filter membrane, conduct the test according to spectrophotometry (Pharmacopoeia of People's Republic of China (<NUM>), Column <NUM>, Appendix IV A). The maximum absorbance between <NUM> and <NUM> is not more than <NUM> %. TPE blends are injection molded into sheet samples. Test solution is prepared by collecting samples with a total surface area of <NUM> cm2, soak in <NUM> water in a flask and boil <NUM>. After cooling down, rinse <NUM> times with <NUM> water each time. Transfer the samples into a conical flask, add <NUM> water, place the flask into an autoclave, heat to <NUM> ± <NUM> within <NUM>. Keep for <NUM> at this temperature, cool down to room temperature within <NUM>-<NUM> and take out the solution.

The components used in the examples include:.

(p1) is a semi-crystalline polypropylene (PP) copolymer having a MFR (<NUM> and <NUM>) of <NUM> dg/min, and a Vicat softening temperature (A50 test method) of <NUM>.

(a3) is a hydrogenated S-B-S with <NUM> wt. % polystyrene content, and <NUM> wt. % of corrected <NUM>,<NUM>-butadiene unit content in the polymerized conjugated diene units before hydrogenation, having Mp =<NUM>/mol.

(y1) is a hydrogenated polybutadiene with Mp <NUM>/mol, <NUM> wt. % Corrected <NUM>,<NUM>-butadieneunit content in the polymerized conjugated diene before hydrogenation.

(p2) is a polypropylene homopolymer with MFR 5dg/min and melting point of <NUM>.

(p3) is a polypropylene random-heterophasic copolymer with MFR 4dg/min and melting temperature of <NUM> (ISO3146) and Vicat A50 of <NUM> (ISO306).

(p4) is a polyolefin elastomer crystalline ethylene-butylene copolymer with MFR (<NUM>; <NUM>) of 5dg/min and melting point of <NUM>.

(i1) is, a primary phenolic antioxidant with resistance to extraction; and (i2) is, a secondary hydrolytically stable phosphite antioxidant.

The compositions and blends were combined in a mixing Brabender at <NUM> for <NUM> mins at <NUM> rpm. The resulting compositions and blends pressed for <NUM> minutes at 230oC to form plates, followed by cooling down under pressure. Table <NUM> shows the HSBC compositions and the blends prepared. Table <NUM> lists the test results for the HSBC compositions and blends.

Examples <NUM>-<NUM> show thermoplastic processability, surprisingly low compression set at <NUM>, very low extractables and no bleed out during the compression set tests in addition to good mechanical properties and medium hardness suitable for various applications. Examples <NUM> and <NUM> with a low content of polypropylene random copolymer, demonstrate superior processing and improved elasticity at > <NUM> and higher hardness.

Blends were also made to compare their performance with those of the blends shown in Table <NUM>. The results are shown in Table <NUM>.

Table <NUM> shows that Example <NUM> exhibits a compression set at <NUM> of > <NUM>%, despite the use of the (a1) block copolymer. Example <NUM> results in a low compression set value at <NUM>° C of <NUM>%, but exhibits undesired bleed out during the compression set test.

Table <NUM> shows the effect of PP-content on compound (a1) + (b1) + PP. The ratio (a1): (b1) was <NUM>: <NUM>. Blend with <NUM>% (p1) has high hardness and CS70 > <NUM>%.

Table <NUM> are TPE blends (Examples <NUM>-<NUM>). Blends with <NUM> parts (a1): (b2) varying from <NUM>:<NUM> to <NUM>:<NUM> with (p1) polypropylene show excellent combination of CS70 and hardness. All blends show desirable CS70, hardness, and low UV absorbance.

Table <NUM> are more TPE blends (Examples <NUM>-<NUM>), with ratio (a1): (b2) varying from <NUM> : <NUM> to <NUM> : <NUM>, combined with varying PP types and amounts. All compositions show very low UV absorbance.

Table <NUM> show more TPE blends, with viscosity of blend <NUM> (<NUM> Pa. s) with <NUM> % (p1) being almost the same as a1/b6 viscosity. To enable melt processing for some applications, apparent viscosity measured at <NUM> and shear rate of <NUM> /s should be < <NUM> Pa. s, preferably < <NUM> Pa.

Examples <NUM>-<NUM>: A design of experiments was set up to further investigate achievable properties, with formulations based on <NUM> phr base polymer (a1), varying contents of (b8) and (p1), and <NUM> wt. % (i1) and <NUM> wt. Compounds were produced on a co-rotating twin screw extruder at <NUM>, followed by injection molding at <NUM> into test plates of <NUM> to measure hardness, compression set before and after sterilization and apparent viscosity at <NUM> measured at a shear rate of <NUM> /s.

Most examples except the blends with hardness close to <NUM> Shore A, show an attractive balance of hardness and compression set values at <NUM> of less than <NUM>%. From this data set, formulation numbers <NUM>, <NUM>, <NUM> and <NUM> were selected for further testing, based on CS70 and hardness, according to specific test methods required for different applications and depending on the end-use region. Example <NUM> shows the best combination of properties with UV absorbance < <NUM>%, low penetration force, low compression set at <NUM> (after sterilization), low hardness and excellent processing (viscosity at <NUM> and shear rate <NUM>/s of <NUM> Pa.

For IV stopper tests via any of test methods YBB-<NUM> / YBB-<NUM>, CP TPE method <NUM>, and USP381, the blends showed extractable amounts of < <NUM>% UV absorption (absorbance <NUM> - <NUM>), and passed static spike retention capacity (<NUM> & <NUM> hrs. ) before and after sterilization with no leakage, fall-out, liquid outflow after needle pull out. The compression set value at <NUM> and <NUM> hrs. was within the expected range of <NUM>-<NUM>% (DIN ISO <NUM>-<NUM>). Hardness Shore A property was also within the range of <NUM>-<NUM> for IV stopper (DIN ISO <NUM>-<NUM>). Penetration force was below the spec. value of 200N (ISO <NUM>), and even < 100N for some examples, or below the spec. value of 80N with an average of 75N (YBB-<NUM>/ YBB-<NUM> / CP TPE method <NUM>) Retention force was above the spec. value of 15N via tests methods YBB-<NUM>, YBB-<NUM>, CP TPE method <NUM> or ISO <NUM>. The blends also passed the flow property test with viscosity in the range of <NUM>-<NUM> Pa. s (injection molded samples with shear viscosity between <NUM>-<NUM> (<NUM>/s), <NUM>). With respect to fragmentation tests via ISO <NUM> / USP381 methods, the samples show < <NUM> particles (> <NUM>), or < <NUM> particles (> <NUM>), or <= <NUM> particles (>= <NUM>), or <= <NUM> particles (> <NUM>).

Similarly for vial stopper evaluations including tests against USP381 / USP382 methods, the samples passed the extractable test with <= <NUM>%, penetration force below the spec. value of < 10N, compression set value at <NUM> and <NUM> hrs. was <NUM>-<NUM>%, and passing the flow property test with viscosity in the range of <NUM>-<NUM> Pa. Hardness Shore A property was also within the range of <NUM>-<NUM> for vial stopper (DIN ISO <NUM>-<NUM>). In fragmentation tests (USP381 / USP382 methods), the samples show < <NUM> particles (><NUM>), or < <NUM> particles (> <NUM>).

Claim 1:
A hydrogenated block copolymer composition comprising components (a) and (b), wherein
component (a) is a selectively hydrogenated block copolymer comprising one or more structures A-B-A, (A-B-A)nX, A-(B-A)n, and (A-B)nX;
component (b) is a selectively hydrogenated block copolymer comprising one or more structures C-D, D-C-D, and (D-C-)nX; and
wherein "n" is <NUM> - <NUM>, and "X" is a residue of a coupling agent;
wherein before hydrogenation,
A is a polymer block of a vinyl aromatic monomer, having a peak molecular weight (Mp) of <NUM> - <NUM>/mol measured according to ASTM <NUM>-<NUM>,
B is a polymer block comprising <NUM> -<NUM> mol% of one or more conjugated dienes, and <NUM>-<NUM> mol% of a vinyl aromatic monomer;
C is a polymer block of a vinyl aromatic monomer, having a peak molecular weight of <NUM> - <NUM>/mol measured according to ASTM <NUM>-<NUM>; and
D is a polymer block comprising <NUM> - <NUM> mol% of one or more conjugated dienes, and <NUM>-<NUM> mol% of a vinyl aromatic monomer;
wherein after hydrogenation,
<NUM> to <NUM> mol% of the polymerized diene units in the polymer blocks B and D are reduced; and
<NUM>-<NUM> mol% of the polymerized vinyl aromatic monomer units in the polymer blocks A, B, C and D are reduced;
wherein the vinyl aromatic monomers of the polymer blocks A, B, C and D are independently same or different and the conjugated diene monomers for the polymer blocks B and D are independently same or different;
wherein the block copolymer (a) has a peak molecular weight of <NUM> - <NUM>,<NUM>/mol and the block copolymer (b) has a peak molecular weight of <NUM> - <NUM>/mol measured according to ASTM <NUM>-<NUM>;
wherein the hydrogenated block copolymer composition has a compression set after <NUM> hrs. at <NUM> of less than <NUM>%, measured according to ASTM D395; and
an apparent viscosity measured at <NUM> and a shear rate of <NUM>/s of < <NUM> Pa. s.