Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
  • B29C41/003—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
  • B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
  • B29C41/14—Dipping a core
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
  • B29C41/02—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor for making articles of definite length, i.e. discrete articles
  • B29C41/22—Making multilayered or multicoloured articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes

Definitions

• the present invention relates to elastomeric articles, particularly but not exclusively gloves and condoms, and also to a method for the production of such articles.
• elastomeric articles such as gloves (e.g. for medical applications such as examination or surgery) and condoms.
• Such articles may be produced by dipping a suitably shaped former into a solution or suspension of the elastomeric material, withdrawing the former from the solution/suspension and evaporating the carrier liquid of the solution/suspension. More than one dipping process may be used to produce the final article.
• elastomeric articles that, in addition to having the required elastomeric properties, they should be resistant to materials with which they come into contact and should have good resistance to oxidation to provide for a reasonable shelf-life of the article. Given that many articles intended for use in biomedical applications require sterilisation by ⁇ -irradiation the oxidation resistance of the material to be used is of particular importance.
• NR vulcanised natural rubber
• NRJatex is by no means ideal however due to the presence of latex proteins and accelerator residues from the vulcanisation process. These chemicals often bloom to the surface of the fabricated article and may be adsorbed within the tissues of a user, thereby causing an allergic, response. The problem is particularly serious with allergies to latex protein and a (protein free) synthetic substitute to NR latex is urgently sought.
• NR latex also suffers from a low resistance to oxidation due to the unsaturated carbon-carbon double bonds present within the cis-l,4-isoprene repeat units within the polymer. This may be mitigated to some extent by the inclusion of anti-oxidants within a formulation to be used for fabricating articles but the anti-oxidants also bloom to the rubber surface and produce an allergenic or cytotoxic response.
• S-EB-S a styrene / ethylene- butylene / styrene triblock co-polymer
• US-A-5, 112,900 describes an elastomeric composition formed from two or more S-EB-S triblock copolymers, which composition has a combination of strength, tactility and resistance to environmental attack.
• composition disclosed in US-A-5, 112,900 incorporates a mineral oil as a plasticiser.
• a plasticiser may migrate over time and give rise to a leechable component yielding deleterious side effects when the device is used.
• SIS a styrene / isoprene / styrene co-polymer
• SBS a styrene / butadiene / styrene co-polymer
• EP-A-0 854174 describes a method of forming powder-free elastomeric gloves from a mixture of a SIS triblock copolymer with a SBS triblock copolymer and an anti-blocking additive
• EP-A-0 931633 discloses a further method of forming a powder-free glove from a synthetic rubber which may be a styrene block copolymer or polychloroprene by applying an elastomeric latex coating to the glove.
• both SIS and SBS copolymers have, by dint of carbon-carbon unsaturated bonds within their structure, poor resistance to oxidisation and this deleteriously affects the shelf-life of elastomeric articles produced therefrom.
• Neither of the European patent specifications identified in the previous paragraph improve the poor ageing characteristics of an SIS or SBS based elastomeric article.
• the manufacturers of SIS or SBS block copolymers include a variety of anti-oxidants to alleviate this problem but this impacts upon their suitability for biomedical applications as the potential for side effects caused by leechable components is to be avoided.
• a further problem of preparing elastomeric protective articles is that the article can adhere to the surface of the former on which it is produced. As the article is typically of the order of 50-250 ⁇ m thick, it is difficult to remove the article from the former without ripping or tearing. Obviously the presence of any imperfections, however minor, in an elastomeric article is to be avoided.
• NR latex and elastomeric SIS or SBS block copolymers tend' to suffer from blocking (the tendency of the elastomeric article to adhere to itself) after being stripped from the former. Indeed this is such a problem with SIS and SBS block copolymers that certain grades are supplied as pellets dusted with powder.
• a powder either in a coagulant dip such that powder is deposited on the former (for glove manufacture) or in a slurry after the article is removed from the ormer (for gloves and condoms).
• powders that may be used for this purpose, such as magnesium carbonate or corn starch to prevent the elastomeric composition from adhering to itself after removal from the former and to facilitate removal of the article.
• the use of such powder does however increase the cost and complexity of the manufacturing process and if use is intended for an application involving contact with internal body fluid (as in the case of catheters, condoms and surgeons gloves) there is a risk that the powder may cause granuloma.
• a powdered article could not be used for an application wherein a requirement for minimal contamination existed (such as an examination glove for procedures within a clean room environment). It is an object of the present invention to obviate or mitigate the above disadvantages.
• an elastomeric material having a laminate structure and being comprised of outer layers of a polyurethane composition and an inner, layer of a styrene-isoprene-styrene (SIS) or a styrene-butadiene-styrene (SBS) block copolymer or a blend thereof.
• SIS styrene-isoprene-styrene
• SBS styrene-butadiene-styrene
• polyurethane as used herein is intended to include polyurethane- ureas.
• the material is preferably a tri-laminate structure comprised of an inner SIS or SBS layer or blend thereof and outer polyurethane layers buf we do not preclude the possibility of there being at least one further inner layer.
• the laminate material of the invention has excellent resistance to oxidation. Without being bound by theory we believe this is due to the polyurethane layers acting as a barrier to oxidation of the SIS/SBS layer and/or as a barrier to migration of anti-oxidant from the SIS/SBS layer.
• An additional advantage is that the material has a reduced tendency to "blocking". This is due to the fact that the polyurethane is a "harder" material than the SIS/SBS layer. This difference in hardnesses means that reduced quantities of blocking agents may be used in the polyurethane layers so as to avoid “blocking", with less possibility that the anti-blocking agents migrate out of the polyurethane layer and the need for powders such as magnesium carbonate or corn starch can be avoided.
• the SIS or SBS layer provides properties of strength, elasticity and softness, and these properties are complemented by the outer polyurethane layers so that the material is eminently suitable for use in producing elastomeric protective articles.
• an elastomeric article comprised of an elastomeric material as defined for the first aspect of the invention.
• the article may, for example, be a glove, a condom, a catheter or a urinary sheath.
• the glove may be for medical use and may, for example, be for use in medical examination or surgery.
• standards governing the physical properties of certain of these articles e.g. ASTM 3577 for surgeons gloves
• other articles such as examination gloves or urinary sheaths
• are not subject to such a standard but good elastomeric properties and freedom from leechable chemicals are deemed highly desirable.
• the laminate material of the first aspect of the invention may be produced in situ during formation of an article in accordance with the second aspect of the invention.
• the article may be produced by dipping of a suitably shaped, former firstly into a solution or suspension of a polyurethane, then into a solution or suspension of an SIS or SBS block copolymer, followed by dipping into a solution of a polyurethane (with drying as necessary between the dipping steps) to "build-up" the laminate structure during formation of the article.
• the material of the first aspect of the invention may be produced in the form of a sheet or the like which is subsequently used for manufacture of an article in accordance with the second aspect of the invention.
• the SIS or SBS layer has a thickness of from 30 to l,000 ⁇ tm, more preferably from 40 to 300 ⁇ m, most preferably from 50 to 200 ⁇ m.
• the polyurethane outer layers have a thickness of from 2 to 1 OO ⁇ m, more preferably from 5 to 50 ⁇ m, most preferably from 10-2 O ⁇ m.
• the "inner" polyurethane layer i.e. the layer that is in contact with the skin of the user, may be thinner than the "outer” layer of polyurethane to aid rapid swelling of absorbed moisture. In these cases it is preferred that the "inner” layer is more than or equal to one third of the thickness of the "outer” layer.
• the SIS/SBS block copolymer is a thermoplastic ABA block copolymer elastomer.
• the styrene content of the SIS/SBS block copolymer is from 15 to 35% (by weight).
• the molecular weight (number average Mn) of the SIS/SBS block copolymer is from 150,000 to 300,000, more preferably from 200,000 to 250,000.
• SIS block copolymers for use in the invention include Kraton D-1161 and 1107 (available from Shell Chemicals, which are styrene/isoprene triblock copolymers with 15% bound styrene) and Vector 4113 (available from Dexco Polymers).
• a further example of a SBS block copolymer for use in the invention is Kraton D-1J84 (available from Shell Chemicals, which is a styrene/isoprene triblock copolymer with 30% bound styrene).
• a blend of SIS and SBS block copolymers may be used. .
• polyurethanes may be used for the outer layers of the laminate provided, of course, that the elastomeric, flexible structure of the laminate is retained.
• the polyurethane may be a hydrophilic polyurethane but more preferably will either comprise a mixture of a hydrophilic polyurethane and a hydrophobic polymer (e.g. a hydrophobic polyurethane) or will be a hydrophobic polyurethane.
• the polyurethane composition of the two outer layers of the laminate may be the same or different. The exact nature of the polyurethane comprising each outer layer will be dependent upon the intended application of the fabricated article.
• the polyurethane composition of at least one (and more preferably both) of the outer layers of the laminate is comprised of a mixture of a hydrophilic polyurethane and a hydrophobic polymer, particularly a hydrophobic polyurethane.
• a mixture of a hydrophilic polyurethane and a hydrophobic polymer provides" a composition which is wetted by water and also one which has greater resistance to alcohol solvents relative to hydrophilic polyurethanes per se.
• the composition is therefore particularly suitable for use in the manufacture of surgical gloves, which generally need to be donned onto wet or damp hands (immediately after the surgeon has "scrubbed-up") since the wetting by water facilitates such donning of the gloves.
• the alcohol resistance of the composition may be of importance if the surgeon donning the glove uses an alcoholic based disinfectant to apply either to his hands or to the outer surface of the glove as part of his "scrub-up" procedure.
• composition comprised of a blend of a hydrophilic polyurethane and a hydrophobic polymer (preferably a hydrophobic polyurethane) it is preferred that the composition is comprised of 20% to 60% by weight of the hydrophilic polyurethane and 40% to 80% by weight of the hydrophobic polymer.
• one or both of the outer layers may contain a hydrophobic polyurethane as the sole polyurethane.
• a hydrophobic polyurethane is suitable as the inner layer of a glove which is to be donned onto a dry hand.
• the hydrophobic polyurethane is useful in providing resistance against alcohol solvents.
• one or both layers may contain a hydrophilic polyurethane as the sole polyurethane.
• a hydrophilic polyurethane as the sole polyurethane.
• An example of this would be a self-lubricating condom wherein the outer surface would be comprised of a hydrophilic polyurethane whereas the inner layer may either be a blend of a hydrophilic and a hydrophobic polyurethane or a hydrophobic polyurethane alone.
• articles in accordance with the invention may be produced by a dipping process in which an appropriately shaped former is successively dipped into, firstly, a polyurethane-containing solution/suspension, secondly into a SIS or SBS containing solution suspension, and thirdly into a polyurethane containing solution/suspension.
• the polyurethane for "dipping" is present in the form of a solution, -most preferably in a polar solvent.
• polar solvents include tetral ydrofuran, methyl ethyl ketone, dimethylformamide, dimetlrylacetamide, N- methyl pyrrolidone, dimethylsulphoxide, oleic acid amide or mixtures thereof. Dimethylformamide is most preferred.
• the polyurethane solution comprises 5-20% by weight (e.g. 8 to 15%) of the polyurethane.
• the solution may also incorporate additional additives such as precipitated silica, which acts as an anti-block agent and although a particulate, it becomes trapped within the polyurethane film structure and renders a powder-free finish and fatty acid amides, such as oleamide, erucamide, stearamide, behanemide, ethylene-bis-oleamide, ethylene-bis-erucamide and ethylene-bis- ' stearamide, which serve to reduce the surface friction produced by the silica and to act as an anti-block in their own right.
• Oleamide oleic acid amide
• Oleamide is the most preferred fatty acid amide.
• Precipitated silica if used, will generally be present in the solution in an amount of 5-10% (by weight of the polyurethane content), whereas a fatty acid amide or mixture of fatty acid amides, if used, will be present in an amount of 1-10% (by weight of the polyurethane content).
• hard hydrophobic waxes such as Carnuba wax (available as Miwax 411 from Michelman Inc.) may be incorporated into the polyurethane solution to provide anti-blocking properties.
• Hard hydrophobic waxes, if used, will generally be present in the solution in an amount of 5-10% (by weight of the polyurethane content).
• a preferred dipping solution has the following composition:
• a particularly preferred initial dipping solution has the following composition:
• a particularly preferred final dipping solution has the following composition:
• additives selected from the group including precipitated silica, fatty acid amides and hard hydrophobic waxes, allows the dipping process to be carried out without the use of a powder (such as magnesium carbonate or corn starch) to prevent adherence to the former.
• the SIS or SBS is also preferably used in the form of a solution, most preferably in an aromatic solvent, most preferably toluene or xylene, although solvents such as tetrahydrofuran may also be used.
• This "dipping" solution may, for example, contain 20-45% (by weight) by weight of the SIS or SBS block copolymer, more preferably 24-35 % (by weight).
• the SIS/SBS solution incorporates a relatively polar liquid which is miscible with the aromatic solvent.
• the use of such a polar liquid in the SIS/SBS solution has been found to prevent or inhibit mottling of the final article, possibly caused by incompatibility between the aromatic solvent of the SIS/SBS solution and the hydrophobic polyurethane.
• the polar liquid may be incorporated in the SIS/SBS solution in an amount of 5-20% by weight of the solution.
• Particularly preferred examples of such polar liquids include NN-dimethylamides, e.g. dimethylacetainide or dimethylformamide, ketones, e.g. butan-2-one or alcohols, e.g. propan-2-ol.
• the SIS/SBS solution may, for example, comprise
• the first (polyurethane) layer applied to the former be relatively thin (e.g. no more than 20-30 microns). Such a thickness may be achieved by relatively slow withdrawal of the former from the polyurethane solution for formation of the first layer.
• the former In the first dipping stage the former is preferably removed from, the fluid medium at from 0.05 to 5 mm per second, most preferably at from 0.2 to lmm per second. In the second dipping stage the former is preferably removed from the fluid medium at from 0.5 to 10 mm per second, most preferably at from 2 to 5mm per second. In the third dipping stage the former is preferably removed from the fluid medium at from 0.2 to 15mm per second, most preferably at from 0.5 to 5mm per second.
• the former is dried between each dipping stage. Drying is preferably carried out at from 80°C to 130°C.
• first dipping stage drying is preferably carried out for from 3 to- 20 minutes, most preferably for from 8 to 12 minutes.
• second dip drying is preferably carried out for from 5 to 25 minutes, most preferably for fiOm 10 to 15 minutes.
• third dip drying is preferably carried out for from 3 to 20 minutes, most preferably for from 8 to 12 minutes.
• the type of former used to fabricate the dipped article depends on the nature of the article to be fabricated.
• the former may be porcelain, either of bisque (a form of porcelain which has been fired but not glazed) or of a glazed ceramic finish, optionally the surface finish may be roughened by sandblasting the former or spraying a roughened finish.
• the former is preferably glass.
• the former may be ceramic, stainless steel, aluminium or glass.
• Hydrophilic polyurethanes for use in accordance with .the invention will ⁇ generally have a soft block incorporating poly(ethyleneoxide) (ethylene glycol) units. Such groups within the backbone of a polyurethane render the capability of water binding and enable the polymer to swell and transmit moisture vapour.
• Suitable hydrophilic polyurethanes will comprise hard and soft blocks with the latter incorporating poly(ethyleneoxide) units desirably having a molecular weight of at least 400 and preferably in the range 400 to 8000.
• the overall content of poly(ethyleneoxide) units in the hydrophilic polyurethane will be at least 10% by weight within the polyol mixture used to produce the softblock.
• Hydrophilic polyurethanes for use in the invention may be step-growth polymers formed via the reaction of an organic diisocyanate (OCN-R-NCO) and appropriate chemical species having two active hydrogen substituents capable of reacting with such diisocyanate groups.
• a suitable polyurethane may be formed by the initial reaction of an aliphatic or aromatic diisocyanate with a relatively low molecular weight polymer (MW 400-8,000, preferably 1,000-2,000) incorporating poly(ethylene oxide) units and having end groups comprising an active hydrogen species (e.g. OH or NH ), in the ratio of n+1: n moles respectively to form a pre- polymer.
• diisocyanates include:
• relatively low molecular weight polymers that may be used include:
• polyethylene glycol having terminal hydroxyl or amine functionality a block co-polymer (AB, ABA etc) of ethylene glycol and a hydrophobic polyol (such as propylene glycol or polytetramethylene glycol) having terminal hydroxyl or amine functionality or mixtures thereof.
• a block co-polymer AB, ABA etc
• hydrophobic polyol such as propylene glycol or polytetramethylene glycol
• polytetramethylene glycol polypropylene glycol, polycaprolactone polyol, polyethylene adipate polyol, polytetramethylene adipate polyol, polyethylene- tetramethylene adipate polyol, polyhexamethylene adipate polyol, polyethylene- hexamethylene adipate polyol, polyhexamethylene carbonate glycol, polyethylene- hexamethylene carbonate glycol, and mixtures thereof.
• polyol has been used to refer to a polyester material containing terminal hydroxyl functionality and glycol a polyether (or polycarbonate) material containing terminal hydroxyl functionality. In each of the above examples the terminal hydroxyl functionality may be replaced by terminal amine functionality.
• the pre-polymer is then extended by reaction with a low molecular weight aliphatic compound comprising difunctional groups with active hydrogen species (e.g. OH or NH 2 ) and a diisocyanate in the ratio of x:x-l moles per mole of prepolymer.
• a low molecular weight aliphatic compound comprising difunctional groups with active hydrogen species may be either diols or diamines or alkanolamines, representative examples of which include:
• ethylene glycol diethylene glycol, triethylene glycol, 1,2 propylene glycol, 1,3 propylene glycol, 1,4 butane diol, 1,3 butane diol, 2,3 butane diol, 1,6 hexane diol, 2,5 hexane diol, and mixtures thereof.
• the prepolymer may be produced by reaction ofn+1 moles of the diisocyanate (e.g. as listed under (i)) with (n) moles of a polyether glycol as identified under (iii) above. The product of this reaction is then further reacted with 2 molar equivalents of a hydroxyl or amine terminated low molecular weight polymer containing poly(ethylene oxide) units such as exemplified under (ii) above (i.e. one mole of prepolymer is reacted with 2 moles of a poly(ethylene oxide) containing polymer)
• the extension reaction of the prepolymer is then effected with a low molecular weight aliphatic compound having two active hydrogen substituents, e.g. as exemplified by compounds (iv)-(vi) above and a diisocyanate (such as exemplified by (i) above) in the ratio of x:x+l moles per mole of prepolymer.
• a low molecular weight aliphatic compound having two active hydrogen substituents e.g. as exemplified by compounds (iv)-(vi) above and a diisocyanate (such as exemplified by (i) above) in the ratio of x:x+l moles per mole of prepolymer.
• the hydrophilic polyurethane will generally have a hard block content of 18- 35%>.
• the hard block will be derived from an aromatic diisocyanate and a butane diol.
• the soft block will be derived from an aromatic diisocyanate and a polyethylene oxide of the type described above.
• the polyethylene oxide may be capped with amine groups.
• Hyphil 1 is an aromatic polyether-urethane, having a hard block content of 18-23% with a soft structure of both hydrophilic and hydrophobic polyols, the former having a molecular weight 2,000 and the latter of 1,000.
• Hyphil 2 is an aromatic polyether-urethane, having a hard block content of 20-24% with a soft structure of both hydrophilic and hydrophobic polyols each having a molecular weight of 2,000.
• the hydrophobic polymer used in admixture with the hydrophilic polyuretliane may for example be a hydrophobic polyurethane.
• the hydrophobic polyurethane will not contain any ethylene glycol units in the soft block structure. Units of short ethylene glycol units (as identified above) may be incorporated into the hard block of a polyurethane without producing a material with appreciable hydrophilic properties providing that there are not longer chains of polyethylene glycol in the soft block of the material.
• Hydrophobic polyurethanes for use in the invention may be produced by initial formation of a prepolymer from n+1 moles of an organic diisocyanate (such as exemplified by the compounds listed under (i) above and n moles of a compound having a hydrophobic moiety and two active hydrogen substituents, e.g. as exemplified by the compounds listed under (iii) above.
• an organic diisocyanate such as exemplified by the compounds listed under (i) above
• n moles of a compound having a hydrophobic moiety and two active hydrogen substituents e.g. as exemplified by the compounds listed under (iii) above.
• the pre-polymer may then be extended by reaction with a low molecular weight aliphatic compoimds comprising difunctional groups with active hydrogen species (e.g. OH or NH ) (e.g. as exemplified under (iv)-(vi) above) and a diisocyanate (e.g. as exemplified by (i) above) in the ratio of x:x-l moles.
• a low molecular weight aliphatic compoimds comprising difunctional groups with active hydrogen species (e.g. OH or NH ) (e.g. as exemplified under (iv)-(vi) above) and a diisocyanate (e.g. as exemplified by (i) above) in the ratio of x:x-l moles.
• the hydrophobic polyurethane may for example have a hard block content of 20-45%, more preferably 25-35%.
• the hard block may be derived by reaction of an aromatic diisocyanate with a butane diol.
• the soft block may be derived from an aromatic diisocyanate and polytetramethylene diol.
• Hyphob 1 is an aromatic polyether-urethane, having a hard block content of 26-29%. This material is based upon a polyol of molecular weight 2,000.
• the polymer is produced in a "two-shot” reaction (i.e. the pre-polymer formation step if carried out in the first stage before the extension step is effected in the second step).
• the reaction may be carried out a bulk "one-shot” reaction (i.e. all reactants are mixed together in a single stage reaction).
• a coinmercially available bisque finished porcelain former was dipped into the polyurethane fluid medium and withdrawn slowly at a speed of 0.25mm / second.
• the coated former was dried at 80°C for 9 minutes, allowed to cool to ambient temperature before being dipped into the SIS fluid medium at 2mm / second.
• the former was withdrawn at 2mm / second and dried at 80°C for 13 minutes.
• the warm former was again immersed into the polyurethane solution, withdrawn at 2mm / second and dried at 80°C for a further 9 minutes.
• the finished glove showed no cosmetic imperfections, was non-blocking and had excellent dry and damp hand donnability.
• the glove was unaffected by exposure to a 70:30 isopropyl alcohol / water mixture.
• the glove was deemed to be suitable as a surgeons glove.
• a commercially available bisque finished surgical glove former was dipped into the polyurethane and withdrawn slowly at 0J5 mm / second.
• the coated former was dried at 80°C for 5 minutes, allowed to cool to ambient temperature and dipped into the Kraton 1161 solution. The former was withdrawn at 2mm / second and dried at 80°C for 11 minutes.
• the coated warm former was again immersed into the polyurethane solution, withdrawn at 0J5mm / second and dried at 80°C for 5 minutes.
• the dried glove was leached in water at 60°C for 5 minutes before being hand shipped and dried in a conventional tumble dryer.
• the glove was non blocking and had excellent dry and damp hand doimability. On exposure to a 70:30 isopropyl alcohol / water mixture, the glove showed no. evidence of separation. The finished glove showed no signs of cosmetic imperfection at the finger tips. However there was some evidence of small bubbles trapped within the glove, predominantly along the sides of the fingers.
• the glove was deemed to be suitable as a powder flee examination glove involving the use of alcohol based reagents where minor cosmetic imperfections were not considered to impair the performance of the glove.
• Example 3
• a commercially available bisque finished surgical glove former was dipped into the polyurethane and withdrawn slowly at 0.25 mm / second.
• the coated former was dried at 80°C for 5 minutes, allowed to cool to ambient temperature and dipped into the Kraton 1161 solution. The former was withdrawn at 2mm / second and dried at 80°C for 11 minutes.
• the coated warm former was again immersed into the polyurethane solution, withdrawn at 0J5mm / second and dried at 80°C for 5 minutes.
• the dried glove was leached in water at 60°C for 5 minutes before being hand stripped and dried in a conventional tumble dryer.
• the glove was non blocking with good dry hand donnability and showed no signs of degradation or de-lamination after 2 minutes immersion in a 70:30 isopropyl alcohol / water mixture.
• the finished glove had an irregular mottled appearance on the finger region, which was attributed to swelling of the initial polyurethane layer on application of the Kraton layer.
• the glove was deemed to be suitable as a powder free examination glove involving the use of alcohol based reagents where minor cosmetic imperfections were not considered to impair the performance of the glove.
• the glove was non blocking with good dry hand donnability.
• the glove also possessed a pleasant "silky” feel against the skin and showed no signs of delamination after 2 minutes immersion in a 70:30 isopropyl alcohol / water mixture.
• the finished glove had an irregular mottled appearance, which was attributed to swelling of the initial polyurethane layer on application of the Kraton layer.
• the glove was deemed to be suitable as a powder free examination glove involving the use of alcohol based reagents where minor cosmetic imperfections were not considered to impair the performance of the glove.
• the finished glove had no cosmetic defects, which was attributed to the limited amount of swell of the hydrophilic polyurethane in toluene.
• the glove was non blocking with good dry and damp- hand donnability. However, on exposure to a 70:30 isopropyl alcohol / water mixture, the finished glove showed signs of layer separation.
• the glove was deemed suitable for use as an examination glove where cosmetic appearance was deemed to be important but no use of alcohol based reagents in the examination procedure was envisaged. Likewise the glove was deemed suitable as a surgeons glove providing no alcohol-based reagents were to be used.
• Styrene Block Copolymer Fluid Medium Formulation (as for Example 3) A glove was prepared following the same ' procedure outlined in Example 2.
• the finished glove had no cosmetic defects and was non blocking with reasonable dry hand doimability. However, the finished glove showed partial separation after 2 minutes immersion in a 70:30 isopropyl alcohol / water mixture.
• the glove was deemed suitable for use as an examination glove where cosmetic appearance was deemed to be important but no use of alcohol based reagents in the examination procedure was envisaged. Likewise the glove was deemed suitable as a surgeons glove providing no alcohol-based reagents were to be used.
• a glove was prepared following the same procedure outlined in Example 2.
• the finished glove had no cosmetic defects, was non blocking and had excellent dry and damp hand donnability. However, on exposure to a 70:30 isopropyl alcohol / water mixture, the glove showed partial separation.
• the glove was deemed suitable for use as an examination glove where cosmetic appearance was deemed t ⁇ be important but no use of alcohol based reagents in the examination procedure was envisaged. Likewise the glove was deemed suitable as a surgeons glove providing no alcohol-based reagents were to be used.
• a glove was prepared following the same procedure outlined in Example 2. The glove was non blocking and had excellent dry and damp hand doimability. Also on exposure to a 70:30 isopropyl alcohol / water mixture, the glove showed no evidence of separation. However, the finished glove had a mottled appearance at the finger tips.
• the glove was deemed to be suitable as a powder free examination glove involving the use of alcohol based reagents where minor cosmetic imperfections were not considered to impair the performance of the glove.
• a commercially available bisque finished porcelain former was dipped into the initial polyurethane formulation and withdrawn at 0J5 mm / second.
• the coated former was dried at 80°C for 9 minutes, allowed to cool to. ambient temperature before being dipped into the SIS solution at 2.5mm / second. The former was withdrawn at 2.5mm / second and dried at 100°C for 13 minutes.
• the warm former was immersed into the final polyurethane formulation, withdrawn at 1 mm / second and dried at 100°C for a further 9 minutes.
• the glove was leached in water at 60°C before being hand stripped from the former.
• the glove was inverted on stripping and was re-inverted before being dried in a conventional tumble drier.
• the glove had a single wall thickness of 180 microns in the finger and palm areas.
• the finished glove showed no cosmetic imperfections, was non-blocking and had excellent dry and damp hand donnability.
• the outer surface of the glove was unaffected by exposure to 70:30 IPA / water.
• the glove was deemed suitable as a surgeon's glove to be used when alcohol based reagents were to be used only in contact with the outer glove surface.
• a commercially available bisque finished porcelain former was dipped into the initial polyurethane formulation at 2.5mm /second and withdrawn at 3.3 mm / second.
• the coated former was dried at 80°C for 9 minutes, allowed to cool to ambient temperature before being dipped into the SIS solution at 2.5mm / second.
• the former was withdrawn at 4.3 mm / second and dried at 100°C for 15 minutes.
• the warm former was immersed into the final polyurethane formulation at 2.5 mm / second and withdrawn at 3.3 mm / second and dried at 100°C for a further 9 minutes.
• the glove was leached in water at 45°C for 5 minutes before being hand shipped from the former.
• the glove was inverted on stripping and was re-inverted before being dried in a conventional tumble drier.
• the glove had a single wall thickness of 160 microns in the finger and palm areas.
• the finished glove showed no cosmetic imperfections, was non-blocking and had excellent dry and damp hand donnability.
• the outer surface of the glove was affected by exposure to 70:30 IPA / water for two minutes and displayed evidence of de-lamination.
• the glove was deemed suitable as a glove to be used when alcohol based reagents were to be used only in contact with the outer glove surface for short periods of time.
• a commercially available bisque finished porcelain former was dipped into the initial polym-ethane formulation at 2.5mm /second and withdrawn at 3.3 mm / second.
• the coated former was dried at 80°C for 9 minutes, allowed to cool to ambient temperature before being dipped into the SIS solution at 2.5mm / second.
• the former was withdrawn at 4.3 mm / second and dried at 100°C for 15 minutes.
• the warm former was immersed into the final polyurethane formulation at 2.5 mm / second and withdrawn at 3.3 mm / second and dried at 100°C for a further 9 minutes.
• the glove was leached in water at 45°C for 5 minutes before being hand stripped from the former.
• the glove was inverted on stripping and was re-inverted before being dried in a conventional tumble drier.
• the glove had a single wall thickness of 160 microns in the finger and palm areas.
• the finished glove showed no cosmetic imperfections, was non-blocking and had excellent dry and damp hand donnability.
• the outer surface of the glove was unaffected by exposure to 70:30 IPA / water for two minutes.
• the glove was deemed suitable as a surgeon's glove to be used when alcohol based reagents were to be used only in contact with the outer glove surface.
• a condom was made using the following polyurethane and styrene block copolymer formulations :-
• a commercially available glass condom former was dipped into the polyurethane formulation at 2.5 mm / second and withdrawn slowly at 0.25 mm / second.
• the coated former was dried at 80°C for 9 minutes, allowed to cool to ambient temperature before being dipped into the SIS fluid medium at 2.5 mm / second. The former was withdrawn at 1 mm per second at dried at 100°C for 13 minutes.
• the warm former was again immersed into the polyurethane formulation at 2.5 mm / second, withdrawn at 0.28 mm / second, and dried at 100°C for 9 minutes.
• the condom was leached in water at 60 °C for 5 minutes before being hand stripped.
• the condom was dried in a conventional . tumble drier without the application of powder.
• the finished condom had a single wall thickness of 80 microns and a lubiicious feel when hydrated.
• the condom was deemed suitable as a condom with a self-lubricating surface.
• a minary sheath was made using the following polyurethane and styrene block copolymer formulations :-
• a commercially available stainless steel former was dipped into the polyurethane fluid medium at 2.5 mm / second and withdrawn slowly at a speed of 0.5 mm / second.
• the coated former was dried at 80°C for 9 minutes allowed to cool to ambient temperature before being dipped into the SIS fluid medium at 2.5 mm / second.
• the former was withdrawn at 2 mm / second at dried at 100°C for 11 minutes.
• the warm former was again immersed into the polyurethane formulation at 2.5 mm / second, withdrawn at 1 mm / second and dried at 100 °C for 9 minutes.
• the urinary sheath was leached in water at 60 °C for 5 minutes before being hand stripped.
• the urinary sheath was dried in a conventional tumble drier without the application of powder.
• the finished urinary sheath had a single wall thickness of 100 microns and a lubricious feel when hydrated.
• the urinary sheath was deemed suitable for use as a urinary catheter sheath.
• a commercially available bisque finished porcelain glove former was dipped into the SIS fluid medimn at 2.5 mm / second and withdrawn at 2 mm / second.
• the coated former was dried at 100°C for 13 minutes before being leached in water at 60°C for five minutes.
• a commercially available bisque finished surgical glove former was dipped into the SIS fluid medium at 2.5 mm / second and withdrawn at 2 mm / second.
• the coated former was dried at 100°C for 13 minutes.
• the warm former was immersed into the polyurethane formulation at 2.5 mm / second, withdrawn at 1 mm / second and dried at 100°C for a further 9 minutes.
• the glove was leached in water at 60 °C before being hand stripped from the former.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Materials For Medical Uses (AREA)
• Orthopedics, Nursing, And Contraception (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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Family Cites Families (3)

• 2000
  • 2000-06-30 GB GB0016117A patent/GB0016117D0/en not_active Ceased
• 2001
  • 2001-06-26 WO PCT/GB2001/002809 patent/WO2002002321A1/en not_active Application Discontinuation
  • 2001-06-26 JP JP2002506930A patent/JP2004501807A/ja active Pending
  • 2001-06-26 AU AU2001269258A patent/AU2001269258A1/en not_active Abandoned
  • 2001-06-26 EP EP01947609A patent/EP1294562A1/de not_active Withdrawn

Non-Patent Citations (1)

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