摘要:
The object of the present invention is to offer a PTFE resin that can be prepared by common molding methods such as compression molding and the like without the necessity for expensive equipment or hot coining methods or the like that are deleterious to productivity, and where harmful substances are not generated during manufacture, and convention strength, crystallinity and surface characteristics are preserved, and where there is neither anisotropy nor heterogeneity, and where the PTFE resin is more difficult to deform than is conventional PTFE resin. A crosslinkable polytetrafluoroethylene composition of matter contains polytetrafluoroethylene and a crosslinking agent. The polytetrafluoroethylene possesses at least one reactive functional group selected from the group consisting of cyano (—CN), carboxyl (—COOH), alkoxycarbonyl (—COOR (where R is a monovalent organic group)) and acid halide (—COX (where X is a halogen atom)) on at least one of the main chain and side chain terminal ends. The crosslinking agent reacts with one or a plurality of reactive functional groups and can form a cyclic structure.
摘要:
The present invention provides a polytetrafluoroethylene powder having moldability/processability as well as electrical characteristics in microwave bands. The present invention is a modified polytetrafluoroethylene powder which has (1) a dielectric loss tangent at 12 GHz of not higher than 2.0×10−4 and (2) a cylinder extrusion pressure of not higher than 45 MPa at a reduction ratio of 1600.
摘要:
The present invention provides a polytetrafluoroethylene molded article, particularly a PTFE molded article for high-frequency insulation, which is excellent in various electric properties and mechanical properties in a high frequency range of 3 to 30 GHz. The present invention also provides PTFE fine powder, which is excellent in extrusion moldability and capable of providing the molded article, and a process for preparing the same. More specifically, the present invention relates to a polytetrafluoroethylene fine powder having a standard specific gravity of 2.180 to 2.225, which is obtained by contacting polytetrafluoroethylene fine powder having a standard specific gravity of 2.180 to 2.225 with a fluorine radical source, wherein tanδ at 12 GHz of a film comprising the powder, which is obtained by cooling at 5 to 50° C./second after baking, is at most 2.0×10−4.
摘要:
The present invention provides a TFE resin molding material which has electric characteristics, particularly low dielectric dissipation factor, in a microwave area, can also lower extrusion pressure as the material is of low molecular weight and can provide a molded article excellent in surface smoothness. The material is especially useful as a coating material for a coaxial cable for equipment in which microwave is used, including satellite transmitting equipment and a cell phone base station. A tetrafluoroethylene resin molding material excellent in high frequency electric characteristics, which provides a molded article having a dielectric constant of at most 2.2 and a dielectric dissipation factor of at most 1.60×10−4 under 12 GHz, and a standard specific gravity of at least 2.192 and less than 2.3 is provided. As the tetrafluoroethylene resin, a tetrafluoroethylene homopolymer or a copolymer of 99.9 to 99.9999% by mole of tetrafluoroethylene and 0.0001 to 0.1% by mole of a specific fluoromonomer is used.
摘要:
A modified polytetrafluoroethylene fine powder containing agglomerates of colloidal particles with an average particle size of from 0.05 to 0.5 &mgr;m which comprise a copolymer of tetrafluoroethylene and an olefin-monomer represented by X(CF2)nOCF═CF2 in which X is a hydrogen atom, a fluorine atom or a chlorine atom, and n is an integer of 1 to 6, and/or C3F7(OCF2CF2CF2)m[OCF(CF3)CF2]pOCF═CF2 in which m and p are independently an integer of 0 to 4, provided that the sum of m and p is not 0 (zero), a content of the olefin monomer being from 0.02 to 0.3 wt. %, wherein the copolymer has a molecular weight distribution Mw/Mn of from 1.5 to 4.5 and a standard specific gravity of from 2.135 to 2.175. This modified polytetrafluoroethylene has good paste extrudability, and provides molded articles having good mechanical properties, in particular, pressure resistance.
摘要:
A belt-shaped base of a female member of a zipper tape attached to an inner surface of a bag body has a wide portion that extends wider toward an opening of the bag body than a belt-shaped base of the male member. An open tape is disposed on the wide portion and a seal layer is laminated on a surface of the open tape. A first projecting portion is also provided on the wide portion. A second projecting portion is provided on an opening-side end of the belt-shaped base. The projecting portions have a substantially trapezoidal cross section. When the zipper tape is bonded to the bag body and is sealed by the seal layer, a gap is provided between the open tape and the first and the second projecting portions.
摘要:
A belt-shaped base of a female member of a zipper tape attached to an inner surface of a bag body has a wide portion that extends wider toward an opening of the bag body than a belt-shaped base of the male member. An open tape is disposed on the wide portion and a seal layer is laminated on a surface of the open tape. A first projecting portion is also provided on the wide portion. A second projecting portion is provided on an opening-side end of the belt-shaped base. The projecting portions have a substantially trapezoidal cross section. When the zipper tape is bonded to the bag body and is sealed by the seal layer, a gap is provided between the open tape and the first and the second projecting portions.
摘要:
In the preparation of a modified polytetrafluoroethylene fine powder by polymerizing tetrafluoroethylene in an aqueous medium in the presence of a water soluble fluorine-containing dispersant, a fluoroalkyl vinyl ether is added to a reaction system at latest at a start of a reaction and a copolymerization reaction of the fluoroalkyl vinyl ether with tetrafluoroethylene is initiated, and a chain transfer agent is added to the reaction system after at least 80% of tetrafluoroethylene to be polymerized is consumed. The obtained modified polytetrafluoroethylene fine powder has good molding properties, in particular, extrusion properties, and high heat resistance.
摘要:
A cutting tape includes a leading portion, a first base, a second base and a seal layer. The leading portion is welded on a sealant layer with the seal layer interposed therebetween. The first base and the second base, which are laminated on the leading portion, respectively include thin laminated portions and body portions to be welded on the sealant layer. The laminated portions are welded on the leading portion. The body portions respectively have a substantially trapezoidal cross section projecting toward the sealant layer and having an inclined surface adjacent to the leading portion.
摘要:
A cutting tape includes a leading portion, a first base, a second base and a seal layer. The leading portion is welded on a sealant layer with the seal layer interposed therebetween. The first base and the second base, which are laminated on the leading portion, respectively include thin laminated portions and body portions to be welded on the sealant layer. The laminated portions are welded on the leading portion. The body portions respectively have a substantially trapezoidal cross section projecting toward the sealant layer and having an inclined surface adjacent to the leading portion.