摘要:
A flat and nearly mechanically isotropic polymer film or sheet, or a tube, can be formed by laminating two or more films, preferably by coextrusion of a liquid crystal polymer film and a thermoplastic polymer film. A liquid crystal polymer layer may be combined with one or more thermoplastic polymer layer in various arrangements. The liquid crystal, and possibly the thermoplastic as well, may have a controlled molecular orientation. The film may be formed by passing a polymer through a set of two or three tubular rotors which are concentric and have facing surfaces which define inner and outer annular polymer flow channels.
摘要:
A flat and nearly mechanically isotropic polymer film or sheet, or a tube, can be formed by laminating two or more films, preferably by coextrusion of a liquid crystal polymer film and a thermoplastic polymer film. A liquid crystal polymer layer may be combined with one or more thermoplastic polymer layer in various arrangements. The liquid crystal, and possibly the thermoplastic as well, may have a controlled molecular orientation. The film may be formed by passing a polymer through a set of two or three tubular rotors which are concentric and have facing surfaces which define inner and outer annular polymer flow channels.
摘要:
A flat and nearly mechanically isotropic liquid crystal polymer film (38) can be formed by laminating two continuous biaxially oriented films. A laminate is produced having two thin outer surface portions which are oriented in one direction, and a relatively thick inner portion oriented in a transverse direction. The film may also be formed by passing a polymer through a set of three tubular rotors (30) which are concentric and having surfaces which are concentric and define inner and outer annular polymer flow channels (33, 35) between them. These rotors may rotate in the same or opposite directions. Another way to make the film is with a slit-type die (90) through which a polymer flows in one direction, while a moving band (91) passes continuously in a transverse direction. These ordered-polymer films are useful, for example, in the production of printed circuit boards.
摘要:
The present invention relates to articles of manfacture, such as films, tubes, and coatings, comprising a multiaxially oriented film having a planar morphology, wherein the article of manfacture comprises at least one thermoplastic flexible polymer, at least one thermotropic liquid crystalline polymer, or a blend thereof. Recyclable articles of manufacture having improved barrier properties are also provided.
摘要:
Coatings of multiaxially oriented Thermotropic Liquid Crystalline Polymer (TLCP) are provided to elongated members. Suitable members include glass rods, glass fibers, pipes, beams, and other oval or polygonal members having an essentially regular cross-section. Members of ceramic, plastic, or metal can also be coated. This extrusion is performed using a die having inner and outer mandrels capable of rotating in opposite directions. Concentricity between inner and outer mandrels of the die is maintained to assure uniform coating thickness. In order to produce a high level of multiaxial orientation at lower die rotational speeds, the die design may include spiraling feed zones on one or both facing surfaces of the inner and outer mandrels. The application of the multiaxially oriented coating provides superior impermeability to water vapor and oxygen, and increased strength to the elongated member in the axial direction.
摘要:
The present invention is directed to the use of multiaxially oriented (e.g., biaxially) thermotropic polymers as a substrate material for the preparation of printed wire boards (PWB). In preferred embodiments, the PWB of the present invention comprises a generic, high density, organic multilayer PWB comprising XYDAR.RTM. and/or VECTRA.RTM. films, capable of being employed as a high density leadless perimeter and in grid array ceramic chip packages.
摘要:
A flat and nearly mechanically isotropic polymer film or sheet, or a tube, can be formed by laminating two or more films, preferably by coextrusion of a liquid crystal polymer film and a thermoplastic polymer film. A liquid crystal polymer layer may be combined with one or more thermoplastic polymer layer in various arrangements. The liquid crystal, and possibly the thermoplastic as well, may have a controlled molecular orientation. The film may also be formed by passing a polymer through a set of two or three tubular rotors which are concentric and have facing surfaces which define inner and outer annular polymer flow channels.
摘要:
This invention relates in general to the formation of multiaxially (e.g., biaxially) oriented films from high molecular weight lyotropic or thermotropic polymers (homopolymers, copolymers, and the like), wherein due to the processing conditions employed, the films have a controlled molecular orientation. The films of the present invention are preferably prepared from rod-like extended-chain, aromatic- heterocyclic polymers. These polymers generally fall into two classes; first, those that are modified in solution form, i.e., lyotropic liquid crystalline polymers; and second, those that are modSTATEMENT OF GOVERNMENT INTERESTFunding for the present invention was obtained from the Government of the United States by virtue of Contract Nos. F33615-83-C-5120 and N00164-87-C-0050, from the Departments of the Air Force and the Navy, respectively. Thus, the Government of the United States has certain rights in and to the invention claimed herein.
摘要:
This invention relates in general to the formation of thick films having a biaxial molecular orientation. Such films are prepared in accordance with the present invention from rod-like extended chain aromatic-heterocyclic ordered polymers. Such films have high tensile strength, modulus, and environmental resistance characteristics. A preferred ordered polymer for use in the present invention is poly (para-phenylenebenzo bisthiazole), (PBT), a compound having the structure: ##STR1## The present invention is also directed to methods and apparatus suitable for producing biaxially oriented films, coatings, and like materials from ordered polymers, preferably PBT.
摘要:
The present invention is based upon the discovery that ordered polymers, such as PBzT, can be readily formed into tubular structures which retain a biaxial orientation imparted thereto during processing, and that these rigid, high-stiffness tubular components can exhibit near zero coefficient of thermal expansion (CTE). Zero CTE materials are not adversely affected by vast swings in temperature, e.g., from very hot to very cold in short periods of time, nor are they adversely affected by long term exposure to either temperature extreme. The tubular components of the present invention thus represent a revolutionary advance in space based hardware, as the extreme temperatures experienced there will not affect rigidity of structures built using these components.