Hydrocarbon block copolymer with dispersed polysiloxane
First Claim
1. An inflatable cuff in the form of a web surrounding a medical tubing, the ends of the web being sealed to said medical tubing to define an inflatable space, said cuff being formed of a composition comprisingan elastomeric, thermoplastic hydrocarbon block copolymer, said copolymer having a total molecular weight of about 50,000 to 600,000;
- polysiloxane dispersed substantially uniformly throughout said copolymer, having a viscosity of about 20 to 13,000 centistokes, and comprising about 0.1 to 8 percent of the total weight of said composition; and
mineral oil dispersed substantially uniformly throughout said copolymer and comprising less than about 60 percent of the total weight of said composition.
4 Assignments
0 Petitions
Accused Products
Abstract
A composition of matter composed of a thermoplastic elastomeric hydrocarbon block copolymer having 0.1 to 8 percent polysiloxane, or silicone oil, uniformly distributed throughout. The composition exhibits improved surface, elasticity, and tensile strength characteristics as well as superior processibility. The block copolymer may take the form of styrene-ethylene-butylene-styrene in which the styrene blocks have a molecular weight of 5,000 to 40,000 and the ethylene-butylene block has a molecular weight of 20,000 to 500,000. Uniformly dispersed mineral oil may constitute 10 to 60 percent of the composition'"'"'s total weight which may also include less than 45 percent polypropylene. Combining the copolymer with the silicone oil occurs under the influence of a pressure of 1,500 to 2,500 p.s.i. such as provided by extrusion blending. The resulting elastomeric composition may extrude in sheets as thin as 0.015, 0.010, or even 0.005 inch, which a puller may thin even further. The resulting composition has a surface smoothness microscopically characteristic of silicone rubber. As one of its many varied uses, the elastomer may find use as an inflatable cuff or balloon on such medical devices as endotracheal tubes. The high elasticity of the composition permits it to act, when in the trachea, as a high residual volume type endotracheal tube, except that it avoids the folds which permit aspiration fluids to channel to the patient'"'"'s lungs. The pressure it exerts against the tracheal wall falls even below the high volume device. When not inflated, the material returns to a sufficiently small volume that it acts as a low volume device for ease of insertion and withdrawal.
120 Citations
44 Claims
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1. An inflatable cuff in the form of a web surrounding a medical tubing, the ends of the web being sealed to said medical tubing to define an inflatable space, said cuff being formed of a composition comprising
an elastomeric, thermoplastic hydrocarbon block copolymer, said copolymer having a total molecular weight of about 50,000 to 600,000; -
polysiloxane dispersed substantially uniformly throughout said copolymer, having a viscosity of about 20 to 13,000 centistokes, and comprising about 0.1 to 8 percent of the total weight of said composition; and mineral oil dispersed substantially uniformly throughout said copolymer and comprising less than about 60 percent of the total weight of said composition. - View Dependent Claims (2, 3, 4, 5)
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6. In a medical device having:
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(A) an elongated hollow tube through which fluid can pass; (B) an inflatable, fluid tight cuff sealed to and surrounding said tube and near the distal end of said tube; and (C) pressure means for introducing an inflating fluid pressure into said cuff the improvement wherein at least a portion of said cuff is formed from an elastomeric composition comprising an elastomeric, thermoplastic, hydrocarbon block copolymer and polysiloxane substantially uniformly distributed throughout said copolymer. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. The method of fabricating a medical device comprising:
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(A) placing a fluid-tight web forming from a thermoplastic composition comprising an elastomeric thermoplastic hydrocarbon block copolymer and polysiloxane substantially uniformly distributed throughout said copolymer (1) around an elongated hollow tube through which fluid can pas, said tube having fluid passage means for channeling the flow of fluid under pressure from one end of said tube to an area exterior of said tube and nearer the other end of said tube and (2) over said area of said tube; and (B) sealing said web to said tube to provide a fluidtight chamber around and on the exterior of said tube, said chamber being (1) formed in part from said web and (2) in fluid communication with said fluid passage means. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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Specification