Abstract: An expandable bladder has at least one first layer of butyl material and one second layer of silicone material, radially external to the first layer. The first and second layers have an undulated interface profile defining mechanical-engagement elements between the first and second elastomer materials. A process for manufacturing bladder as well as a tire molding and vulcanizing apparatus incorporating the bladder.

Abstract: A correcting apparatus of a seamless belt includes a bottomed cylindrical main body that has an inner peripheral surface formed of mirror surface and that accommodates a seamless belt at a distance from the inner peripheral surface, a lid body detachably attached to the main body, a fixing unit that fixes an upper end and a lower end of the seamless belt to the mirror surface, a pressing unit that presses the seamless belt accommodated in the main body against the mirror surface, and a heating unit that heats the mirror surface.

Abstract: A cylindrical vulcanization housing with an axis XX?, formed by a lower pan and an upper pan kept in the closed position during vulcanization, and delimiting an enclosure containing a mould and associated components that delimit a closed internal volume (Vi) configured to receive a heat transfer fluid at a pressure P1, the projection of said internal volume (Vi) on a plane perpendicular to the axis XX? forming a surface whose area is S1. A reshaping envelope (3), configured to receive a fluid at a pressure P2 is positioned axially between the axially outer walls of the mould parts and the vulcanization pan, the projection of said volume of said reshaping envelope on a plane perpendicular to the axis XX? delimiting a surface with an area S2, such that S2*P2 is greater than S1*P1.

Abstract: Provided is a tire bladder of an acrylic rubber composition which is superior in processing safety and mechanical characteristics and further exhibits high elongation in a high temperature atmosphere. A tire bladder of an acrylic rubber composition comprising: 100 parts by mass of an acrylic rubber containing 94.5 to 99.5 mass % of an alkyl (meth)acrylate-derived structural unit and 0.5 to 3 mass % of a monoalkyl maleate and/or monoalkoxyalkyl maleate-derived structural unit; 30 to 200 parts by mass of a carbon black having an arithmetic average particle diameter, as determined according to JIS-Z8901, of 20 to 30 nm and a DBP oil absorption of 70 to 130 ml/100 g; 0.1 to 5 parts by mass of an imidazole compound as antioxidant and 0.1 to 10 parts by mass of a polyamine compound as vulcanizing agent.

Abstract: The invention relates to compositions in the form of silicone oil emulsions which are intended to be applied to curing bladders as a mold-release agent during tire production.

Abstract: A layup mandrel includes a shell having a tool surface on which plies may be laid up. The shape of the shell is changed by an actuator.

Abstract: Disclosed is a mixture to create expandable curing bladders for use in the curing process of rubber compositions such as tires. The bladders have an increased service with the addition of the aramid fibers to the rubber polymer. The aramid fibers increase the tear resistance of the cured product allowing for an increased number of expansions and contractions of the rubber polymer during the curing process. The use of these aramid fibers allows the tire curing bladders to cure more tires without changing out the bladder increasing the cost efficiency of the tire curing bladder.

Abstract: A method for manufacturing a bladder for use in manufacturing tires having a surface-modified rubber layer on an outer surface side of a base rubber layer, including the steps of: forming an uncross-linked body of the surface-modified rubber layer by molding a rubber composition including a modified butyl rubber composition and an organic peroxide and applying a siloxane compound having a (meth)acryloyl group to a surface of this rubber molded body; forming the base rubber layer from an unvulcanized body or vulcanized body formed from a rubber composition different than the modified butyl rubber composition; laminating the uncross-linked body of the surface-modified rubber layer on the outer surface side of the base rubber layer; and heat treating.

Abstract: A method of treating a surface of an object comprising a rubber material and in particular a bladder for use in a process for making a vehicle tyre. The method comprises subjecting the surface to a gas at a low pressure at which the gas is susceptible of forming plasma, and causing the gas to form plasma. In order to obtain repellent properties of the surface of the rubber material fluorine gas such as tetrafluormethane or hexafluorethane is used. Preferably the treatment is performed until there is obtained a surface layer of the rubber material with properties modified by the treatment having an expected lifetime corresponding to the expected lifetime of the object.

Abstract: An expandable bladder has at least one first layer of butyl material and one second layer of silicone material, radially external to the first layer. The first and second layers have an undulated interface profile defining mechanical-engagement elements between the first and second elastomer materials. A process for manufacturing bladder as well as a tire molding and vulcanising apparatus incorporating the bladder.

Abstract: In a center mechanism of a tire vulcanizing machine, including an upper clamp ring for grasping an upper opening end part of a bladder, a lower clamp ring for grasping a lower opening end part of the bladder, a hub on a side of a lower mold for supporting the lower clamp ring, a spacer connected to the hub and supported on the side of the lower mold to be ascendable and descendable, and a center post supported by the spacer to be extensible and contractible, the hub and the spacer are formed as members separate from each other, and are divisibly bound to each other by bolts.

Abstract: The bladder for vulcanizing tires having a plurality of first air-release grooves provided on the outer surface of a bladder body and each formed so as to extend from one to the other of the tire circumferential direction and extend toward one side of the tire-width direction, and a plurality of second air-release grooves provided on the outer surface of a bladder body and each formed so as to extend from one to the other of the tire circumferential direction and extend toward the other side of the tire-width direction. By this, the outer surface of the bladder body is divided into a plurality of areas by each of the air-release grooves. Also, the vertexes of each of the areas are angular toward the tire-circumferential direction. Therefore, the pressure contact between each of the areas and the inner surface of the tire is easily released starting at the said vertexes of each of the areas as release starting points.

Abstract: An expandable bladder for shaping a pneumatic tire is provided. The bladder in an unmounted, relaxed state has a shaped body having a pair of opposed annular beads, said body further comprising a central portion, sidewall portions, and shoulder portions interposed between the central portion and the sidewall portions, wherein the body is defined by an outer contour surface and an inner contour surface, wherein the central portion has gauge which increases to a maximum value axially inward of the shoulder portion, and wherein the bladder gauge in the shoulder is less than the maximum value, and wherein the bladder gauge increases from the shoulder to the bead.

Abstract: A method for manufacturing a bladder for use in manufacturing tires having a surface-modified rubber layer on an outer surface side of a base rubber layer, including the steps of: forming an uncross-linked body of the surface-modified rubber layer by molding a rubber composition including a modified butyl rubber composition and an organic peroxide and applying a siloxane compound having a (meth)acryloyl group to a surface of this rubber molded body; forming the base rubber layer from an unvulcanized body or vulcanized body formed from a rubber composition different than the modified butyl rubber composition; laminating the uncross-linked body of the surface-modified rubber layer on the outer surface side of the base rubber layer; and heat treating.

Abstract: The constituent elements of a carcass structure of a tire are formed by laying elementary components on a building support including an inflatable bladder set in an inflated condition in which it substantially reproduces the inner configuration of the carcass structure to be obtained. A belt structure carrying a tread band, both produced separately, is coaxially disposed around the carcass structure formed on the building support and applied thereto following a radial expansion of the inflatable bladder. In a vulcanization mold, the building support is submitted to an over-inflation step to press the tire against the inner walls of the mold. The circumferential edges of the inflatable bladder are in engagement with respective anchoring flanges with possibility of movement in a radial direction, so as to be submitted to an elastic expansion during the over-inflation step.

Abstract: Disclosed is a mixture to create expandable curing bladders for use in the curing process of rubber compositions such as tires. The bladders have an increased service with the addition of the aramid fibers to the rubber polymer. The aramid fibers increase the tear resistance of the cured product allowing for an increased number of expansions and contractions of the rubber polymer during the curing process. The use of these aramid fibers allows the tire curing bladders to cure more tires without changing out the bladder increasing the cost efficiency of the tire curing bladder.

Abstract: A method for controlling a phase of moulding an annular fixing structure of a green tyre includes: introducing the green tyre into a curing mould including an inflatable bladder; delimiting at least one portion of the annular fixing structure by using a first and a second surface opposed to each other; bringing the first surface and the second surface so as to bring a portion of the first surface and a portion of the second surface into contact with a corresponding radially inner and axially inner surface portion and a corresponding radially inner and axially outer surface portion, respectively, the annular fixing structure generating a first squeezing pressure; inflating the inflatable bladder of the curing mould so as to bring the first and the second surfaces closer together, thus generating a second squeezing pressure in such a way as to shape the radially inner and axially inner surface portions and the radially inner and axially outer surface portions of the annular fixing structure.

Abstract: This invention relates to an expandable curing bladder for use in curing rubber products; the bladder comprising an inner layer and an outer layer bonded to the first layer; the inner layer comprising a rubber composition comprised of, based on parts weight per 100 parts by weight rubber (phr): an isobutylene copolymer rubber selected from butyl rubber and/or halobutyl rubber, wherein said butyl rubber comprises a copolymer of isobutylene and isoprene which contains from about 0.5 to about 5 weight percent units derived from isoprene; wherein said halobutyl rubber is a halogenated butyl rubber comprises a chlorinated or brominated copolymer of isobutylene and isoprene which contains from about 0.5 to about 5 weight percent units derived from isoprene; and the outer layer comprising a rubber composition comprising a silicon rubber.

Abstract: Process for molding and vulcanizing a tire, in which a tire blank is placed in a curing press including a mold intended to form the outer shape of the tire, and a pressing member for transmitting the molding pressure and the heat needed to vulcanize the internal portion of the tire blank. A removable elastic membrane, which includes perforations passing completely therethrough, is interposed, during the molding and the vulcanizing step, between the inner surface of the tire and the pressing member, so as to form, by the constituent material of the internal wall of the tire flowing into the perforations, noise-attenuating protuberances distributed over the internal surface of the tire.

Abstract: An apparatus for shaping a green tire carcass is provided having a bladder mounted to a first and second support, a retractable support shaft mounted inside the bladder, and upper and lower bead ring for mounting the beads of the tire carcass thereon, wherein one of said bead rings has a channel in fluid communication with a pressurized source of fluid, wherein said channel has an outlet located between said bladder and said carcass for injecting pressurized fluid between the carcass and the bladder.

Abstract: An expandable bladder for manufacturing pneumatic tyres is used in combination with a vulcanisation apparatus including, for example, a mould having a plurality of sidewall plates and tread sectors that, when the mould is closed, delimit a moulding cavity suitable for housing the green pneumatic tyre to be cured. The expandable bladder includes an elastomeric material obtained by curing an elastomeric composition which includes at least one butyl rubber and at least one compound having at least one double bond and an at least partially fluorinated alkyl or polyoxyalkylene chain.

Abstract: A bladder for tire production comprises a silicone rubber composition comprising (A) 100 parts by mass of a specified straight-chain diorganopolysiloxane; (B) 0.01-10 parts by mass of a specified organohydrogenpolysiloxane; (C) 20-80 parts by mass of a dry silica; and (D) 0.1-1000 ppm of a platinum group metal catalyst as converted to a weight of a platinum group metal per a total mass of the components (A) and (B).

Abstract: A tire forming bladder composed of an elastomeric membrane constructed and shaped for curing low aspect ratio tires. The bladder includes clamping feet to enable it to be clamped onto a post for insertion into a tire curing mold. The bladder has a cross-sectional profile where the distance between the clamping feet is less than the distance between the shoulder areas of the bladder. In addition, the shoulder areas of the bladder are of a thinner gauge than the remainder of the bladder membrane and accordingly expands a greater amount than the rest of the bladder membrane when pressurized.

Abstract: By increasing an area of the fluid discharge ports to increase a discharge capacity, drain water can quickly be discharged. Furthermore, the number of fluid supply ports is increased and the ports are equally spaced to thereby quickly and uniformly fill a heated steam or the like into a bladder. As a result, it is possible to reduce a cycle time of a tire vulcanizing step to thereby increase productivity in a fluid supply/discharge head of the bladder in a tire vulcanizing machine. In the tire vulcanizing machine, the fluid supply ports and the fluid discharge ports which are open to face an inside of the bladder are formed in the head block, the fluid discharge ports are disposed on the lower side of the head block, the fluid supply ports are disposed on the upper side of the head block, and the fluid discharge ports and the fluid supply ports are not disposed on the same plane.

Abstract: Disclosed is a gas cycle apparatus for a tire vulcanizer, configured to increase the circulating flow rate of a heating gas by preventing a gas feeder of the gas cycle apparatus from being subjected to an excessive load caused by a drain, and thereby capable of shortening the tire vulcanizing time by improving the temperature difference eliminating capacity in a bladder, to thereby allow the enhancement of the production capacity of tires. A gas circulating flow path 2 constituted by allowing a forward flow path 2a and a return flow path 2b to communicate with each other, is connected to a bladder 1; a gas supply flow path 3 is connected to the forward flow path; an air-water separation section 5 is provided on the way through the return flow path; the return flow path is connected to an upper space 5a of the air-water separation section; and a gas discharge flow path 4 is connected to a lower space 5b of the air-water separation section.

Abstract: An expandable bladder for shaping a pneumatic tire to be mounted inside a tire curing press has a pair of opposing annular beads and an expansion portion located between the pair of annular beads. The expansion portion of the bladder has a central portion, shoulder portions, and sidewall portions. When the bladder is in a mounted but uninflated mode, the shoulder portions have a radius of curvature less than infinity. At a distance (x) from each end of the central portion, the bladder has an increased thickness in the shoulder and upper sidewall portions.

Abstract: An expandable, toroidal shaped bladder for use in a tire curing press has a pair of opposing annular beads and an expansion portion location between the pair of annular beads. The expansion portion of the bladder has a central portion, shoulder portions, and sidewall portions. When the bladder is in a mounted but uninflated mode, the shoulder portions of the bladder have a radius of curvature R1 significantly less than a radius of curvature Rc of the central portion. The shoulder portions have a bubble or square-like configuration.

Abstract: This invention relates to an expandable curing bladder of a butyl rubber composition containing a micro-encapsulated polysiloxane lubricant for delivering lubricity to the surface of the bladder. The invention further relates to a process of curing tires with such bladder.

Abstract: A method and apparatus for vulcanizing tires are provided. An unvulcanized tire is transferred and loaded onto a lower mold member when a plurality of arcuate sector mold members aligned along the peripheral direction locate at the radially outermost positions as well as upper ends of the sector mold members incline radially outwards about their lower ends. An upper mold member moves toward the lower mold member while the sector mold members are swung about their lower ends to straightly stand the sector mold members, and the sector mold members are then synchronously displaced radially inwards, so that the unvulcanized tire is hermetically enclosed in a mold space formed by these mold members. The unvulcanized tire is vulcanized within the mold space to give a vulcanized tire.

Abstract: The invention relates to expandable butyl rubber bladders for use in curing presses for hydrocarbon rubbers such as pneumatic tires. The bladders are a crosslinked butyl rubber composition comprising isobutylene repeat units and the bladder composition contains ultra high molecular weight polyethylene, alone or in combination with graphite and/or fluorinated ethylene polymers, dispersed within the bladder composition. The bladder composition may also contain castor oil, corn oil and/or soya-bean oil. The invention also relates to a method of curing tires by utilizing such butyl rubber bladder.

Abstract: An object of the present invention is to provide a bladder which is unlikely to have a shapal variation along the inner wall surface of the tire and can satisfactorily extend along the inner wall surface of the tire. An inventive bladder is used to press the inner wall surface of the tire by a pressurized heating medium during the vulcanization of a green tire and is comprised of a fabric layer (purl stitched fabric layer 12) and rubber layers (silicone rubber layers 11, 13) placed one over another. Elongation rates of the fabric layer in warp direction and in weft direction both exceed 15% and satisfy: 0.4≦elongation rate in weft direction/elongation rate in warp direction ≦6.0. Since the fabric layer has good extensibility, it can elongate with the rubber layers.

Abstract: A center post assembly for a tire curing press comprising a center post having a upper component disposed above a lower component. The upper component is movable between a first position wherein the upper component is adjacent to the lower component and a second position wherein the upper component is axially displaced away from the lower component and substantially adjacent to an upper bead of a green tire assembly. The center post assembly further includes a bladder sealingly clamped to the upper and lower components. The bladder is in fluid communication with a fluid supply. The upper component moves between said first and second positions due to expansion of the bladder caused by introduction of fluid into the bladder from the fluid supply allowing the bladder to evenly disperse on the inner surface of the green tire assembly substantially reducing the risk of the bladder being damaged by the mold as it closes.

Abstract: An object of the present invention is to provide a bladder which is unlikely to have a shapal variation along the inner wall surface of the tire and can satisfactorily extend along the inner wall surface of the tire. An inventive bladder is used to press the inner wall surface of the tire by a pressurized heating medium during the vulcanization of a green tire and is comprised of a fabric layer (purl stitched fabric layer 12) and rubber layers (silicone rubber layers 11, 13) placed one over another. Elongation rates of the fabric layer in warp direction and in weft direction both exceed 15% and satisfy: 0.4≦elongation rate in weft direction/elongation rate in warp direction≦6.0. Since the fabric layer has good extensibility, it can elongate with the rubber layers.

Abstract: A center mechanism of a tire press according to the present invention, wherein if the size of a lower mold and the size of a tire are changed, a nut member engaged with external thread of a cylindrical member is rotated and driven whereby a lower clamp portion is moved at a position adjusted to a height of the lower mold to thereby enable changing the lower clamp portion to a height position of a lower metal mold irrespective of the size of the lower metal mold.

Abstract: The invention relates to expandable butyl rubber bladders for use in curing presses for hydrocarbon rubbers such as pneumatic tires. The bladders are a crosslinked elastomer comprising isobutylene repeat units and the bladder composition contains lecithin, particularly a modified lecithin, preferably in liquid form, dispersed within the bladder composition. The bladder composition may also contain castor oil, corn oil and/or soya-bean oil. The bladder composition may also contain at least one of graphite and polytetrafluoroethylene powder. The invention also relates to a method of curing tires by utilizing such butyl rubber bladder.

Abstract: Spacers for bladder assemblies for standing post tire curing presses and bladder assemblies for same are provided having a spacer with first and second parts biased by a spring, so that they are freely slidable relative to one another so as to cover the center post of the tire curing press during its operation.

Abstract: An elastomeric member for a tire-building machine, such as an inflatable bead turn-up bladder, center sleeve or bead lock sleeve, includes at least one base layer or sleeve of elastomeric material which terminates in a pair of end members for mounting the sleeve on the tire-building machine. A plurality of reinforcing cords may be embedded within the sleeve to provide internal reinforcement. A strip of an abrasion-resistantmaterial is bonded to all or a portion of the inner or outer surfaces of the sleeve to protect those areas of the sleeve that are subject to abrasion when contacting various portions of the tire or tire-building machine during assembly of a green tire carcass. A coating of an adhesion-release material may be applied to portions of the strip of abrasion-resistant material to reduce adhesion of the sleeve to the tacky elastomeric portions of the green tire carcass when contacted by expansion or movement of the sleeve during assembly of the green tire.

Abstract: In a central mechanism for a tire vulcanizer in accordance with the present invention, after a tire has been vulcanized (a bladder is expanded), a clamp rod is elevated to elevate a lower ring and separate it from a housing. After that, the clamp rod is turned so that a claw of a claw mechanism between the lower ring and the clamp rod can pass through. Then, a pin fixing a post to an upper ring is pulled out, and a bladder assembly is hung and carried out of the vulcanizer to replace the bladder and O-rings. After the bladder and other parts have been replaced, the bladder assembly is hung and mounted to the vulcanizer so that the hole for the claw mechanism of the lower ring is aligned with the upper end of the clamp rod. At this time, when the claw of the claw mechanism passes through, the lower ring is supported by the elevated clamp rod, and the lower ring and a supply/discharge opening of the housing is aligned with each other.

Abstract: Disclosed are expandable bladders for use in curing presses for rubber compositions such as pneumatic tires. The bladders are a crosslinked elastomer comprising an isobutylene rubbery polymer. The bladder composition includes alkylphenoxypoly(alkyleneoxy)-alkanol which improves the release characteristics of the cured bladder from a tire innerliner cured in contact with said bladder. The improved release characteristics allow rubber compositions such as tires to be molded with fewer defects caused during release of the bladder from the tires or caused by abraded or deformed bladders. The use of alkylphenoxypoly(alkyleneoxy)alkanol also increases the useful life time of the bladder allowing more tires to be cured without changing bladders.

Abstract: Expandable bladders for use in curing presses for hydrocarbon rubbers, such as pneumatic tires, are a crosslinked elastomer composition including isobutylene repeat units. When PTFE and/or graphite is present, they can be cured with brominated phenolic resins in shorter periods of time. The fluorinated ethylene polymer is added in particulate form and thereafter dispersed throughout the bladder. The fluorinated ethylene polymer may or may not form fibers. The bladders may further include graphite. The bladders generally have enhanced lubricity, reduced adhesion to cured tire innerliners, better resistance to cracking during flexing, and have lower tension set than similar compositions without fluorinated ethylene polymers. The above enhancements allow hydrocarbon rubbers such as tires to be molded with fewer defects caused by abraded or deformed bladders. They also enhance the useful life of the bladder reducing the cost of tire curing.

Abstract: A center mechanism of a tire vulcanizer in accordance with the present invention has an upper clamp ring for holding the upper opening end of a bladder, a lower clamp ring for holding the lower opening end of the bladder, a lower ring on the lower mold side supporting the lower clamp ring, a spacer installed to the lower ring and having a ventilating portion, and a center post elevating cylinder installed to the spacer. The extending portion of piston rod of the center post elevating cylinder is made a center post, the center post is inserted, in such a manner as to be movable vertically, into a through hole formed in the center of the lower ring and the lower clamp ring, and the upper clamp ring is fixed to the upper end portion of center post protruding upward from the through hole of the lower clamp ring.

Abstract: A bladder clamping device for a tire vulcanizing press is disclosed in which a lower ring on which a lower end portion of a bladder is fitted remains fixed to allow the lower end portion of the bladder to be clamped in a condition in which it has been fitted firmly by an operator. The bladder clamping device for a tire vulcanizing press comprises a lower ring and a clamping ring located on the inner side and the outer side relative to each other at a central portion of a lower mold of the tire vulcanizing press for cooperatively clamping a lower end portion of a bladder, and a hydraulic cylinder having a rod connected to the clamping ring for moving the clamping ring upwardly and downwardly relative to the lower ring.

Abstract: In a center mechanism of a tire press, which the tire size is changed, the lower limit position of an upper clamp ring is changed to a shaping height corresponding to the size of the exchanged tire only by changing a setting of a controller. Consequently, the work related to the tire size change is facilitated. A bladder is inflated and tightly comes into contact with the inner face of a green tire while lowering the upper periphery of the bladder to the shaping height corresponding to the tire size.

Abstract: A center mechanism for a tire vulcanizer having a first cylinder whose stroke can be detected with a simplified structure achieves reduction in cost and improvement in working efficiency upon maintenance. The center mechanism expands, while the first cylinder 1 moves downwardly, a bladder 5 into close contact with an inner face of a green tire. A downward stop position of the first cylinder 1 is set in advance by a linear sensor 14. The stroke amount of the first cylinder 1 is detected by a stroke bracket 12 having a stroke portion 12a extending downwardly in parallel to the first cylinder 1 from within a stem 8 and provided so as to advance into the stem 8 together with a cylinder rod 1a, and a linear sensor 14 for detecting the stroke amount of the first cylinder 1 from the stroke portion 12a of the stroke bracket 12 remaining outside the stem 8.

Abstract: Expandable bladders for use in curing presses for hydrocarbon rubbers, such as pneumatic tires, are a crosslinked elastomer composition comprising isobutylene repeat units and including a fluorinated ethylene polymer added in particulate form and thereafter dispersed throughout the bladder. These fluorinated ethylene polymer may or may not form fibers. The bladders may further comprise graphite. A preferred isobutylene elastomer is a brominated copolymer of from 80 to 99 weight percent isobutylene and from 1 to 20 weight percent paramethylstyrene. The bladders have enhanced lubricity, reduced adhesion to cured tire innerliners, better resistance to cracking during flexing, and have lower tension set than similar compositions without fluorinated ethylene polymers. The above enhancements allow hydrocarbon rubbers such as tires to be molded with fewer defects caused by abraded or deformed bladders. They also enhance the useful life of the bladder reducing the cost of tire curing.

Abstract: Disclosed herein is a center mechanism of a tire vulcanizing press, including a press frame; a guide member provided on the press frame, the guide member having a central hole and a peripheral hole formed around the central hole; a cylindrical member slidably guided in the central hole of the guide member in a vertical direction; a hub fixed to an upper end of the cylindrical member for holding a lower portion of a bladder, the hub having a central hole; a center post slidably inserted through the central hole of the hub for holding an upper portion of the bladder; and a cylinder unit provided between the hub and the center post so as to extend in parallel relationship to the center post, for vertically moving the center post relative to the hub, the cylinder unit having a cylinder body and a rod adapted to be advanced upwardly from an upper end of the cylinder body, the rod being inserted through the peripheral hole of the guide member.

Abstract: Hydrocarbon polymers with grafts of polyethers, polylactones, or polyesters from the reaction of phosgene with glycols having from 1 to 4 carbon atoms are disclosed as having good release properties or low adhesion to hydrocarbon rubber materials. The hydrocarbon backbone polymers include EPDM, hydrogenated polybutadiene, and hydrogenated poly(styrene-butadiene) all said polymers having pendant succinic anhydride groups or brominated p-methylstyrene-isobutylene copolymers. The above-referenced graft copolymers along with butadiene-acrylonitrile rubber or epichlorohydrin polymers or copolymers are described as useful polymers to make self-release curing bladders or sleeves for use in making molded articles such as pneumatic tires.

Abstract: Disclosed are expandable bladders for use in curing presses for rubber compositions such as pneumatic tires. The bladders are a crosslinked elastomer comprising an isobutylene rubbery polymer. The bladder composition includes corn oil which improves the release characteristics of the cured bladder from a tire innerliner cured in contact with said bladder. The improved release characteristics have been observed to allow rubber compositions such as tires to be molded with fewer defects caused during release of the bladder from the tires or caused by abraded or deformed bladders. The use of corn oil also has been observed to increase the useful life time of the bladder allowing more tires to be cured without changing bladders. A preferred isobutylene rubbery polymer is a brominated copolymer of isobutylene and p-methylstyrene. The bladder compositions have also been observed to have an enhanced flexibility due to the corn oil.

Abstract: Expandable bladders for use in curing presses for hydrocarbon rubbers such as pneumatic tires are a crosslink elastomer comprising isobutylene repeat units and include graphite. A preferred isobutylene elastomer is a brominated copolymer of isobutylene and p-methylstyrene. The bladders have enhanced lubricity, low adhesion to tire innerliners, and lower hot tension set. The above enhancements allow hydrocarbon rubbers such as tires to be molded with fewer defects caused by abraded or deformed bladders. They also enhance the useful life of the bladder reducing the cost of tire curing.

Abstract: Hydrocarbon polymers with grafts of polyethers, polylactones, or polyesters from the reaction of phosgene with glycols having from 1 to 4 carbon atoms are disclosed as having good release properties or low adhesion to hydrocarbon rubber materials. The hydrocarbon backbone polymers include EPDM, hydrogenated polybutadiene, and hydrogenated poly(styrene-butadiene) all said polymers having pendant succinic anhydride groups or brominated p-methylstyrene-isobutylene copolymers. The above-referenced graft copolymers along with butadiene-acrylonitrile rubber or epichlorohydrin polymers or copolymers are described as useful polymers to make self-release curing bladders or sleeves for use in making molded articles such as pneumatic tires.