Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
2000-05-24
2001-09-18
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
C522S174000, C522S176000, C522S181000, C522S134000, C522S135000, C522S136000, C522S138000, C522S140000, C522S142000, C522S144000, C522S006000, C522S033000, C522S039000, C522S036000, C522S040000, C522S043000, C522S044000, C522S047000, C522S046000
Reexamination Certificate
active
06291543
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to surfacially cross-linked articles, of a type useful in catheter applications, and to a novel method of making such surfacially cross-linked articles.
2. Description of the Related Art
Catheters are widely utilized in a variety of medical interventions in which material is transported to a corporeal locus, e.g. within the vascular system.
The catheter in such applications must be translated through a corporeal lumen, and therefore must be of a flexible character. At the same time, the catheter must possess sufficient structural rigidity to prevent collapse or even partial occlusion as a result of being “threaded” through the tortuous path of the vasculature.
Catheters may be of widely varying type. Catheters are used for example in angioplasty, including guide catheters for procedures such as balloon or laser angioplasty. In some applications, the use of the catheter requires a particular shape or shaping capability.
An example is the Judkins catheter whose distal portion is inserted into the left coronary artery during cardiac intervention. The Judkins catheter is shaped (by heat-forming) with a main straight portion and a curved distal portion, so that its overall form is of generally “J”-shape. The curvate character of the distal portion of the Judkins catheter requires that it have sufficient flexibility to be distended to a linear conformation, and that when introduced into the left coronary arterial locus the distal portion returns to its curvate form (for entry into the ostium of the coronary artery). Catheters of the foregoing types thus require a concurrent flexibility/rigidity enabling the distension of the catheter, with subsequent recovery of an initial shape when the distending force is discontinued.
The art continues to seek improvement in catheter articles.
SUMMARY OF THE INVENTION
The present invention relates to a surfacially cross-linked article and to a method of making the same. The article can be embodied as a catheter or other article that in use requires concurrent flexibility and shape recovery upon deformation and subsequent release of the deforming force.
The surfacial cross-linking in accordance with the invention also is usefully employed to increase hardness or stiffness of the product article, and such hardness or stiffness properties can be selectively imparted to different portions of the product article, by cross-linking the respective surfaces of such portions of the product article to differing extents.
In one aspect, the invention relates to surfacially ultraviolet radiation-cross-linked article formed of a homogeneous composition including an elastoplastic material, a cross-linker component that is cross-linkable by free-radical polymerization, and a free-radical source material generating free radicals in exposure to ultraviolet radiation, wherein the homogeneous composition is surfacially cross-linked by exposure to ultraviolet radiation, wherein the sub-surface bulk volume of the article is non-cross-linked, and wherein the article is resiliently deformable from and resiliently recoverable to an initial shape of the article, e.g., the shape of the article when it was exposed to ultraviolet radiation for surfacial cross-linking thereof.
In another aspect, the invention relates to a method of fabricating a surfacially ultraviolet radiation-cross-linked article, comprising the steps of: forming a precursor structure for the article of a homogeneous composition including an elastoplastic material, a cross-linker component that is cross-linkable by free-radical polymerization, and a free-radical source material generating free radicals in exposure to ultraviolet radiation, and exposing a surface of the precursor structure to ultraviolet radiation for sufficient time and under sufficient radiation intensity to surfacially cross-link the composition, to yield the surfacially ultraviolet radiation-cross-linked article, wherein the sub-surface bulk volume of the article is non-cross-linked, and the article is resiliently deformable from and resiliently recoverable to a shape of the precursor structure, e.g., the shape it possessed when it was exposed to ultraviolet radiation for Surfacial cross-linking thereof.
Other aspects, features and embodiments of the invention will be more fully apparent from the ensuing disclosure and appended claims.
REFERENCES:
patent: 4414372 (1983-11-01), Farnham et al.
patent: 4444816 (1984-04-01), Richards et al.
patent: 4626458 (1986-12-01), Pithouse et al.
patent: 4711942 (1987-12-01), Webster
patent: 4771116 (1988-09-01), Citron
patent: 5019634 (1991-05-01), Boettcher et al.
patent: 5021524 (1991-06-01), Dicker et al.
patent: 5274028 (1993-12-01), Bertrand et al.
patent: 5786426 (1998-07-01), Sperling et al.
patent: 5965630 (1999-10-01), Imafuko et al.
patent: 5965631 (1999-10-01), Nicolson et al.
patent: 5993415 (1999-11-01), O'Neil et al.
patent: 262 629 B1 (1988-04-01), None
patent: 0 849 296 A2 (1998-06-01), None
Encyclopedia of Polymer Science and Engineering, John Wiley & Sons, vol. 7, p. 580, 1987.
Journal American Chemical Society, Urszula Kolczek, Gunther Rist, Jurt Dietliker and Jakob Wirz, “Reaction Mechanism of Monoacyl-and Bisacylphosphosphine Oxide Photo initiators Studied by P-, C-, and H-DICNP and ESR”, 1996, 118, 6477-6489.
Hultquist Steven J.
McClendon Sanza L.
Polyzen Inc.
Seidleck James J.
LandOfFree
Surfacially cross-linked elastoplastic articles, and method... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Surfacially cross-linked elastoplastic articles, and method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Surfacially cross-linked elastoplastic articles, and method... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2517688