1981 results about "Transition temperature" patented technology

A shape-memory device manufactured from shape memory material includes multiple activation temperatures. The multiple activation temperatures arise from either the heat treatment of the device during manufacturing, or by combining different elements with different activation temperatures. To manufacture a shape-memory device with multiple activation temperatures, it is formed into a first shape. A first portion of the shape-memory device is heated to a first temperature, and a second portion of the shape-memory device is heated to a second temperature. The shape-memory device is then worked into a second shape. Accordingly, the first portion has a first transition temperature, and the second portion has a second transition temperature. In use, the shape-memory device is placed into a desired position. Energy is applied such that the first portion, second portion, or both portions are transformed.

A phase change memory cell includes first and second electrodes electrically coupled by a phase change element. At least a section of the phase change element comprises a higher reset transition temperature portion and a lower reset transition temperature portion. The lower reset transition temperature portion comprises a phase change region which can be transitioned, by the passage of electrical current therethrough, from generally crystalline to generally amorphous states at a lower temperature than the higher reset transition temperature portion. The phase change element may comprise an outer, generally tubular, higher reset transition temperature portion surrounding an inner, lower reset transition temperature portion.

A transfer film comprising a base film, a transfer layer, and a transfer auxiliary layer formed between the base film and the transfer layer so as to be in contact with at least the transfer layer, this transfer auxiliary layer having a melting point or a glass transition temperature lower than that of the transfer layer, wherein at least a portion of the transfer layer can be thermally transferred onto a substrate.

In an aspect of the invention, a fluoropolymer dispersion, preferably a PTFE dispersion, is provided that comprises fluoropolymer particles having an average particle size of 10 to 400 nm dispersed in water whereby the dispersion has an amount of solids between 35 and 70% by weight. The dispersion is free of fluorinated surfactant having a molecular weight of less than 1000 g / mol (hereinafter called low molecular weight fluorinated surfactant) or contains the low molecular weight fluorinated surfactant in an amount of not more than 0.05% by weight based on the total weight solids of the dispersion. The dispersion further comprises a non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants and one or more non-fluorinated anionic surfactants. Through the use of a non-fluorinated anionic surfactant, a dispersion is obtained that has a low viscosity at room temperature (20° C.). The dispersion is further free of aromatic group containing non-ionic surfactants and is accordingly environmentally more friendly and can yield coatings that are less susceptible of discoloration. The amount and nature of the non-ionic non-fluorinated surfactant or mixture of non-ionic non-fluorinated surfactants is selected such that the Viscosity Transition Temperature (VTT) (measured as set forth in the examples) of the fluoropolymer dispersion is at least 26, preferably at least 28° C. In a further aspect of the invention, a method is provided to obtain the aforementioned dispersion.

A series of medical instruments can be made with the use of shape memory tube with a transformation temperature that is above or below the ambient temperature. In the first case, the material behaves with the shape memory effect and in the second case the behavior is superelastic. The wall of the tube has been provided with a plurality of slots in specific places, often near or at the distal end of the instrument, and in specific arrangements which allow local variations in diameter, shape, and / or length. These variations can either be caused by the memory effect during temperature change or by superelastic behavior during change of the mechanical influences on the memory metal by the surrounding material.

Multi-component fibers having enhanced reversible thermal properties and methods of manufacturing thereof are described. In one embodiment, a multi-component fiber includes a fiber body formed from a set of elongated members, and at least one of the set of elongated members includes a temperature regulating material having a latent heat of at least 40 J / g and a transition temperature in the range of 22° C. to 40° C. The temperature regulating material provides thermal regulation based on at least one of absorption and release of the latent heat at the transition temperature. The multi-component fiber can be formed via a melt spinning process or a solution spinning process and can be used or incorporated in various products where a thermal regulating property is desired. For example, the multi-component fiber can be used in textiles, apparel, footwear, medical products, containers and packagings, buildings, appliances, and other products.

Catheter assembly including an elongate shaft comprising a thermoplastic polymer such as a thermoplastic shape memory polymer having a pre-selected glass transition temperature (Tg) and a means for heating the thermoplastic polymer, wherein the thermoplastic polymer is in a rubbery state at temperatures above the glass transition temperature and is in a glassy state at temperatures below the glass transition temperature. The elongate shaft may be selectively heated and cooled to provide sufficient flexibility and retention during a medical procedure.