A method for producing a composition containing low molecular weight polytetrafluoroethylene, the method including: (I) irradiating a composition containing high molecular weight polytetrafluoroethylene with ionizing radiation to obtain a composition containing low molecular weight polytetrafluoroethylene having a melt viscosity at 380° C. in the range of 1.0×10.sup.2 to 7.0×10.sup.5 Pa.Math.s; and (II) carrying out fluorination treatment on the composition containing low molecular weight polytetrafluoroethylene obtained above.

To provide a substrate with low dielectric loss tangent, relative permittivity, transmission loss and thermal expansion coefficient and excellent in mechanical strength, and a metal laminated substrate using this substrate.

A substrate comprising a tetrafluoroethylene polymer and an inorganic filler, wherein the rate of change in dielectric loss tangent at 10 GHz before and after 72 hours of unsaturated pressure cooker test at 120° C. under 85% RH on a 127-μm-thick specimen cut out from the substrate is at most 30%.

Provided here are compositions and methods for preparing porous omniphobic surfaces with desirable chemical and structural properties. The methods include sequential initiated chemical vapor deposition (iCVD) of low surface-energy materials onto a variety of substrates.

Disclosed are polyimide blends and methods of making and using same. The disclosed polyimide blends are prepared by first blending an ionic polymer and a poly(amic acid) to form a poly(amic acid) precursor, followed by cyclization. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

Provided are a polymer film having excellent adhesiveness with a substrate, and a laminate using the polymer film. The polymer film contains a polymer having a dielectric loss tangent of 0.005 or less and a compound having a functional group, in which a concentration of the compound having a functional group is higher on at least one surface of the polymer film than inside of the polymer film.

Aerogel can be coated with a polymerizable resin, which cures to form a polymer-coated aerogel. The coated aerogels can be used structural or thermal insulating component, such as in analytical and scientific devices. Coated aerogels can be further coated with conductive material, a semi-conductive material, a non-conductive material, a resistive material, or a combination thereof.

A fluorine-containing polymer having repeating units derived from (a) a fluorine-containing monomer, (b) a fluorine-free non-crosslinkable monomer, and (c) a fluorine-free crosslinkable monomer. The fluorine-containing monomer (a) is a compound represented by formula: CH.sub.2═C(-X)—C(═O)—Y—Z—Rf . . . (a-I), wherein X is a hydrogen atom, a monovalent organic group or a halogen atom, Y is —O— or —NH—, Z is a direct bond or a divalent organic group, and Rf is a fluoroalkyl group having 1 to 20 carbon atoms. The fluorine-free non-crosslinkable monomer (b) includes (b1) a cyclic hydrocarbon group-containing monomer and (b2) a low Tg monomer, a homopolymer of which has a glass transition temperature (Tg) of lower than 0° C. Also disclosed is a coating composition including the fluorine-containing polymer and a liquid medium, a method for producing a coated article which includes coating an article with the coating composition and a coated article.

A wiring board including a dielectric line containing a resin (A), and a dielectric exterior covering the dielectric line and containing a resin (B). The dielectric exterior has a relative permittivity lower than a relative permittivity of the dielectric line at 6 GHz and 25° C.

The present invention provides a polycarbonate resin composition containing a polycarbonate resin (A), a flame retardant (B), and a fluoropolymer (C), said polycarbonate resin composition being characterized in that the fluidity of the fluoropolymer (C), as measured using a Koka flow tester (under the conditions of a measurement temperature of 400° C., a measurement load of 0.98 MPa, and a die hole diameter of 2.1 mm), is 0.1×10.sup.−3 cm.sup.3/sec or greater. The present invention also provides a sheet and a film.

An air filter medium includes a first porous PTFE membrane and a second porous PTFE membrane. The air filter medium (10) has a first main surface and a second main surface, and the first porous PTFE membrane and the second porous PTFE membrane are arranged so that an air flow moving from the first main surface to the second main surface passes through the first porous PTFE membrane and subsequently through the second porous PTFE membrane. A thickness of the first porous PTFE membrane is in the range of 4 to 40 μm and a specific surface area of the first porous PTFE membrane is 0.5 m.sup.2/g or less.