摘要:
There is provided a fluorine-containing polymer latex providing a fluorine-containing polymer material being excellent in mechanical properties of a molded article. The preparation process comprises emulsion-polymerizing a fluorine-containing olefin solely or a fluorine-containing olefin and other monomer in an aqueous medium in the presence of at least one of fluorine-containing surfactants represented by the formula (I): F(CF2mO—(CF(X)CF2—OnCF(X)COOM wherein X is fluorine atom or a linear or branched lower perfluoroalkyl group; —COOM is a carboxylic acid salt; m is an integer of from 3 to 10; n is 0, 1 or 2. There are also provided a molding material and dispersion comprising a tetrafluoroethylene/hexafluoropropylene copolymer, polytetrafluoroethylene or fluoro elastomer which are obtained by the above-mentioned preparation process.
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:
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 invention provides a TFE polymer capable of providing stretched materials excellent in membrane homogeneity. The present invention is related to a tetrafluoroethylene polymer having stretchability and non-melt-processability and having a standard specific gravity of 2.140 to 2.165, wherein, with regard to the heat-of-fusion curve obtained by subjecting the tetrafluoroethylene polymer in the form of an unbaked polymer to be measured having no history of being heated to a temperature of 300° C. or higher to differential scanning calorimetry at a programming rate of 2° C./minute, the ratio S2/S1 is not lower than 0.90.
摘要:
The present invention provides a novel carboxylic acid derivative, a salt thereof or a hydrate of them which is useful as an insulin sensitizer, and a medicament comprising the derivative as the effective ingredient. More specifically, it provides a carboxylic acid compound represented by the formula (I), a salt thereof or a hydrate of them. In the formula, Ar represents a 6- to 14-membered aromatic ring group which may have at least one substituent; R1, R2, R3, R4, R5, R6, R7 and R8 are the same as or different from each other and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a C1-6 alkyl group or a C1-6 alkoxy group; X represents an oxygen atom or a methylene group; Y represents a group represented by the formula (II) or (III): (wherein Z represents a group represented by the formula (IV): (wherein R9, R10, R11 and R12 are the same as or different from each other and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a C1-6 alkyl group or a C1-6 alkoxy group)); m is 0 or 1; and n is 0 or 1.
摘要:
The present invention provides a porous polytetrafluoroethylene molded article, wherein the specific gravity of the above porous polytetrafluoroethylene molded article is 0.9 to 2.0 and the aspect ratio of a void formed within the above molded article is not lower than 1 but not higher than 3.
摘要:
Provided is a dripping inhibitor excellent in handling characteristics. The present invention provides a dripping inhibitor including a modified polytetrafluoroethylene, the inhibitor having an average particle size of 300 to 800 μm, an apparent density of 0.40 to 0.52 g/ml, a compression ratio of 1.20 or less, an aggregate disintegration degree with 50-sec vibration of 70% or more, a cylinder extrusion pressure at a reduction ratio 1500 of 80 MPa or less, and a standard specific gravity (SSG) of 2.140 to 2.230.
摘要:
Provided is a dripping inhibitor excellent in handling characteristics. The present invention provides a dripping inhibitor including a modified polytetrafluoroethylene, the inhibitor having an average particle size of 300 to 800 μm, an apparent density of 0.40 to 0.52 g/ml, a compression ratio of 1.20 or less, an aggregate disintegration degree with 50-sec vibration of 70% or more, a cylinder extrusion pressure at a reduction ratio 1500 of 80 MPa or less, and a standard specific gravity (SSG) of 2.140 to 2.230.
摘要:
The present invention provides a low-molecular weight polytetrafluoroethylene powder that, when used as an additive in a coating material, etc., can form a coating with excellent texture and gliding properties, while also improving dispersibility and viscosity; and a production process therefor. The present invention is a process for producing a low-molecular weight polytetrafluoroethylene powder, the process comprising: an emulsion polymerization step of polymerizing at least tetrafluoroethylene in the presence of a polymerization initiator and an aqueous medium to produce emulsified particles thereof; an agglomeration step of agglomerating the emulsified particles to form an agglomerated powder thereof; and a suspension polymerization step of polymerizing at least tetrafluoroethylene in the presence of the agglomerated powder, a polymerization initiator, and an aqueous medium.