53results about How to "Loss tangent" patented technology

A wiring board (10) having reduced electromagnetic coupling between electronic devices includes a base board (12) that is adaptable to receive at least one electronic component (14) mounted on the base board (12). At least one hole or void (16) is formed in the base board (12). The hole (16) is separated from the selected electronic component (14) to be isolated against undesired electromagnetic radiation by a portion (18) of the base board (12).

The dielectric-forming composition according to the invention is characterized by consisting of: composite particles for dielectrics in which part or all of the surfaces of inorganic particles with permittivity of 30 or greater are coated with a conductive metal or a compound thereof, or a conductive organic compound or a conductive inorganic material; and (B) a resin component constituted of at least one of a polymerizable compound and a polymer. In addition, another dielectric-forming composition according to the invention is characterized by containing: ultrafine particle-resin composite particles composed of (J) inorganic ultra fine particles with the average particle size of 0.1 mum or smaller, and (B) a resin component constituted of at least one of a polymerizable compound and a polymer, wherein part or all of the surfaces of the inorganic ultrafine particles (J) are coated with the resin component (B), and the ultrafine particle-resin composite particles contain 20% by weight or more of the inorganic ultrafine particles (J); and inorganic particles with the average particle size of 0.1 to 2 mum and permittivity of 30 or greater, or inorganic composite particles in which a conductive metal or a compound thereof, or a conductive organic compound or a conductive inorganic material is deposited on the part or all of the surfaces of the inorganic particles.

Provided is an electroacoustic converter film including: a polymeric composite piezoelectric body having piezoelectric particles dispersed in a viscoelastic matrix which is formed of a polymer material exhibiting viscoelasticity at ordinary temperatures; thin film electrodes formed on both sides of the polymeric composite piezoelectric body; and protective layers formed on surfaces of the thin film electrodes. The electroacoustic converter film serves as a speaker capable of being integrated with a flexible display without impairing lightweightness or flexibility, and has considerable frequency dispersion in the storage modulus and also has a local maximum of the loss tangent around ordinary temperatures. A flexible display, a vocal cord microphone and a musical instrument sensor, in each of which the electroacoustic converter film is used, are also provided.

The present invention discloses a thermosetting resin composition including: a bi-functional or multi-functional epoxy resin, a SMA uses as a curing agent, an allyl phenol such as diallyl bisphenol A used as a co-curing agent and a toughening agent a low-bromine or high-bromine BPA epoxy resin or tetrabromobispheno A (TBBPA or TBBA) uses as a flame retardant agent, and an appropriate solvent. After the resin composition of the invention is cured, the resin composition has lower dielectric property and better thermal reliability and tenacity. A copper clad laminate made of an enhanced material such as glass fiber has lower dielectric constant (Dk) and loss tangent (Df), high Tg, high thermal decomposition temperature (Td), better tenacity and PCB manufacturability, and thus very suitable to be used as a copper clad laminate and a prepreg for manufacturing PCBs or applied as a molding resin material for contraction, automobile and air navigation.

The presently claimed invention is to provide a package for compact RF signal system, and a method to form the package thereof in order to miniaturize the size of package, improve signal integrity, and reduce manufacturing cost. The package comprises a hybrid substrate with a sandwiched structure, in which the hybrid substrate comprises an upper layer and a lower layer with different dielectric properties being separated by an interposer for improving electrical isolation and mechanical stiffness. Metal layers are formed on the sidewalls of the opening to surround an active component, such that the metal sidewalls together with two ground plates in the upper and lower layers constitute a self-shielding enclosure inside the package to protect the active component.

A cyanate ester compound represented by the formula (1), wherein Ar2 represents a phenylene group, a naphthylene group or a biphenylene group, Ar1 represents a naphthylene group or a biphenylene group when Ar2 is a phenylene group, or Ar1 represents a phenylene group, a naphthylene group or a biphenylene group when Ar2 is a naphthylene group or a biphenylene group, Rx represents all substituents of Ar1 each Rx is the same or different and represents hydrogen, an alkyl group or an aryl group, Ry represents all substituents of Ar2, each Ry is the same or different and represents hydrogen, an alkyl group or an aryl group, and n is an integer of 1 to 50.

A golf ball which produces high spin rate and accordingly readily stops even when being shot from a rough or in the rain is provided. Such a golf ball is constituted of a core and a cover and the cover has a loss tangent of 0.15 to 0.70 at -10° C. in a temperature distribution curve for dynamic viscoelasticity measured in a tensile mode under conditions of temperature increasing rate of 4° C. / min, frequency of 10 Hz and initial strain of 1.0 mm.

A resin composition for a laminate, containing at least 10% by weight of a vinyl compound represented by the formula (1), and a prepreg and a metal-clad laminate using the resin composition.

A resin composition for a laminate, containing at least 10% by weight of a vinyl compound represented by the formula (1), and a prepreg and a metal-clad laminate using the resin composition.

The present invention provides a bifunctional phenylene ether oligomer compound having a thermosetting functional group at each terminal, an epoxy resin containing the above oligomer compound and a use thereof. That is, it provides a sealing epoxy resin composition for sealing an electric part, an epoxy resin composition for laminates, a laminate, a printed wiring board, a curable resin composition and a photosensitive resin composition. The resins and resin compositions of the present invention are used in electronics fields in which a low dielectric constant, a low dielectric loss tangent and high toughness are required and also used for various uses such as coating, bonding and molding.

An internally nucleated, toughened cordierite glass-ceramic is disclosed. The cordierite glass-ceramic has good oxidation resistance and fracture toughness and coefficient of thermal expansion rivaling that of silicon nitride. The glass-ceramic may be cast as a liquid. Annealing produces a material of high crystallinity combining high hardness, high Young's modulus, good thermal stability, high strength, low density and good dielectric properties. The glass-ceramic comprises interlocking crystalline phases dominated by cordierite and a second phase having an elongated or acicular structure. A third phase may comprise a crystalline ceramic that promotes acicularity of the second phase. The third phase is preferably capable of twinning.

This invention provides a rubber composition highly balancing flexibility at a low temperature and a low rolling resistance, which is formed by compounding a low-molecular weight conjugated diene-based polymer (B) having at least one functional group, an aromatic vinyl compound content of less than 5% by mass and a weight average molecular weight as measured without terminating by modification through a gel permeation chromatography and converted to polystyrene of not less than 2,000 but less than 150,000 and a filler (C) into a high-molecular weight rubber component (A) having a weight average molecular weight as measured without terminating by modification through a gel permeation chromatography and converted to polystyrene of not less than 150,000.

There is provided a flame-retardant resin composition which can maintain heat resistance at a high level and simultaneously provide low dielectric constant and low dielectric loss tangent while ensuring flame-retardancy without containing any halogen compound causing the generation of harmful substances. This flame-retardant resin composition comprises 0.1 to 200 parts by mass of a cyclophosphazene compound represented by the following formula (1):wherein n=3 to 25; and one of R1 and R2 is CN and the other is H, or both of R1 and R2 are CN, based on 100 parts by mass of a resin component containing a polyfunctional epoxy resin having a biphenyl aralkyl structure, wherein the ratio of cyanophenoxy groups in the compound is 2 to 98% of the total number of phenoxy groups and cyanophenoxy groups in the compound.

The present invention provides a covered electric wire having a covering excellent in electrical characteristics and thermal stability as well as in crack resistance. The present invention is related to a covered electric wire comprising a core wire covered with a tetrafluoroethylene [TFE]-based copolymer comprising TFE-derived TFE units and perfluoro (alkyl vinyl ether) [PAVE]-derived PAVE units, a content of said PAVE unit being in excess of 5% by mass and not higher than 20% by mass relative to all monomer units, containing less than 10 unstable terminal groups per 1×106 carbon atoms, and having a melting point of not lower than 260° C.

The present invention provides a pneumatic tire for a motorcycle, in which tire durability at a relatively high speed in running straight is enhanced with maintaining good gripping performances in cornering situation by optimizing the distribution of loss tangent in tread rubbers constituting a tread portion. The pneumatic tire for a motorcycle includes a pair of bead portions 1 having bead cores embedded therein, a pair of sidewalls 2 extending on the outer side in the tire radial direction from the bead portions 1, and a tread portion 3 extending over the respective sidewall portions 2, wherein the tread portion 3 is constituted of at least four tread regions such that, when the tread regions are viewed in a section in the tire widthwise direction, loss tangent values of rubbers constituting the adjacent tread regions are different from each other, and a loss tangent value of a rubber constituting a center tread region 5 as a tread region including the tire equatorial plane 4, of the tread regions, is smaller than a loss tangent value of each of rubbers constituting other tread regions 6.

Provided is an electroacoustic converter film including: a polymeric composite piezoelectric body having piezoelectric particles dispersed in a viscoelastic matrix which is formed of a polymer material exhibiting viscoelasticity at ordinary temperatures; thin film electrodes formed on both sides of the polymeric composite piezoelectric body; and protective layers formed on surfaces of the thin film electrodes. The electroacoustic converter film serves as a speaker capable of being integrated with a flexible display without impairing lightweightness or flexibility, and has considerable frequency dispersion in the storage modulus and also has a local maximum of the loss tangent around ordinary temperatures. A flexible display, a vocal cord microphone and a musical instrument sensor, in each of which the electroacoustic converter film is used, are also provided.

The present invention provides a thermosetting resin composition comprising (A) a metal salt of disubstituted phosphinic acid, (B) a maleimide compound having a N-substituted maleimide group in a molecule, (C) a 6-substituted guanamine compound or dicyandiamide and (D) an epoxy resin having at least two epoxy groups in a molecule and a prepreg and a laminated plate which are prepared by using the same. The prepregs obtained by impregnating or coating a base material with the thermosetting resin compositions of the present invention and the laminated plates produced by laminating and molding the above prepregs are balanced in all of a copper foil adhesive property, a glass transition temperature, a solder heat resistance, a moisture absorption, a flame resistance, a relative dielectric constant and a dielectric loss tangent, and they are useful as a printed wiring board for electronic instruments.

There are provided a polyfunctional (meth)acrylate compound which has the excellent properties of polyphenylene ether and is excellent in heat resistance and electric characteristics and excellent in reactivity by introducing a polyfunctional (meth)acrylate group into a bifunctional polyphenylene ether oligomer, and a cured product thereof which has a high glass transition temperature and has a low dielectric constant and a low dielectric loss tangent.

The present invention provides a dielectric waveguide having excellent transmission efficiency. The dielectric waveguide includes a polytetrafluoroethylene molded article that has a permittivity of 2.05 or higher at 2.45 GHz or 12 GHz, a loss tangent of 1.20×10−4 or lower at 2.45 GHz or 12 GHz, and a hardness of 95 or higher.

A tunable resonant system (100) and a method for a varying the resonant characteristics of a resonant cavity (102). The resonant cavity (102) is enclosed by a conductive material that has at least one aperture (104) for coupling the resonant cavity (102) to an RF signal propagating in a circuit device (160). A fluidic dielectric (108) having at least one among a permittivity, a permeability and a loss tangent is at least partially disposed within the resonant cavity (102). A dielectric barrier (105) can be provided within the aperture to prevent fluid (108) from escaping the resonant cavity. A composition processor (101) is adapted for dynamically changing a composition or volume of the fluidic dielectric to vary at least one among the permittivity, the permeability and / or the loss tangent to vary, or maintain constant, a center frequency, a bandwidth, a quality factor (Q) or an impedance of the resonant cavity (102).

The invention relates to a composite material, a high-frequency circuit substrate made from the composite material and a making method of the high-frequency circuit substrate. The composite material includes: a thermosetting composition including a more than 60 percent of vinyl containing Butadiene styrene copolymer resin with molecular weight less than 11,000, a more than 60 percent of vinyl containing polybutadiene resin with polarity groups, and a maleic anhydride grafted polybutadiene styrene copolymer with molecular weight more than 50,000; a fiberglass cloth; a powder filler; and a cure initiator. The composite material of the prevent invention realizes easy manufacture of the prepreg and high bonding of the copper foil. The high-frequency circuit substrate made from the composite material has low dielectric constant, low dielectric loss tangent, and excellent heat resistance, and is convenient for process operation. Therefore, the composite material is suitable for making the circuit substrate.

This invention provides a rubber composition highly balancing flexibility at a low temperature and a low rolling resistance, which is formed by compounding a low-molecular weight conjugated diene-based polymer (B) having at least one functional group, an aromatic vinyl compound content of less than 5% by mass and a weight average molecular weight as measured without terminating by modification through a gel permeation chromatography and converted to polystyrene of not less than 2,000 but less than 150,000 and a filler (C) into a high-molecular weight rubber component (A) having a weight average molecular weight as measured without terminating by modification through a gel permeation chromatography and converted to polystyrene of not less than 150,000.

An acid anhydride of the formula (4), and a polyimide using the acid anhydride,wherein anhydrides are substituted at sites 3 or sites 4,which acid anhydride is obtained from, as a raw material, a bifunctional phenylene ether oligomer having a number average molecular weight of 500 to 3,000, represented by the formula (1).

This resin composition for high dielectric constant materials contains 40-80% by mass of (A) a resin material and 20-60% by mass of (B) a carbon black. The carbon black (B) has a DBP absorption of 10-50 mL / 100 g and an iodine adsorption of 5-40 mg / g. This resin composition for high dielectric constant materials has a dielectric constant of 4 or more and a dielectric loss tangent of 0.05 or less.

Provided is an electro-acoustic conversion film that is suitably used for a digital speaker or the like, and that includes a polymer composite piezoelectric body formed by dispersing piezoelectric particles in a viscoelastic matrix formed of a polymer material having viscoelasticity at room temperature, and thin-film electrodes provided on both surfaces of the polymer composite piezoelectric body, in which at least one of the thin-film electrodes is divided into a plurality of regions having the same area, and the respective regions are coupled in parallel and grouped to correspond to a weight of each bit digit of a parallel PCM digital signal. Thus, an electro-acoustic conversion film by which a digital speaker in which reverberation or crosstalk between segments is suppressed is obtained is provided.

The present invention provides a pneumatic tire for a motorcycle, in which tire durability at a relatively high speed in running straight is enhanced with maintaining good gripping performances in cornering situation by optimizing the distribution of loss tangent in tread rubbers constituting a tread portion. The pneumatic tire for a motorcycle includes a pair of bead portions 1 having bead cores embedded therein, a pair of sidewalls 2 extending on the outer side in the tire radial direction from the bead portions 1, and a tread portion 3 extending over the respective sidewall portions 2, wherein the tread portion 3 is constituted of at least four tread regions such that, when the tread regions are viewed in a section in the tire widthwise direction, loss tangent values of rubbers constituting the adjacent tread regions are different from each other, and a loss tangent value of a rubber constituting a center tread region 5 as a tread region including the tire equatorial plane 4, of the tread regions, is smaller than a loss tangent value of each of rubbers constituting other tread regions 6.

There is provided a varnish of a low dielectric loss tangent resin composition which is low in viscosity and excellent in storage stability. The varnish of a low dielectric loss tangent resin composition contains a thermosetting monomer (A) having a weight average molecular weight of not more than 1,000, a high polymer (B) having a weight average molecular weight of not less than 5,000, a halogen flame-retardant agent (C), a silicon dioxide filler (D), and an organic solvent (E). The average particle diameter of each the components (C) and (D) is in the range of 0.2 to 3 μm.

Provided is an electro-acoustic conversion film that is suitably used for a digital speaker or the like, and that includes a polymer composite piezoelectric body formed by dispersing piezoelectric particles in a viscoelastic matrix formed of a polymer material having viscoelasticity at room temperature, and thin-film electrodes provided on both surfaces of the polymer composite piezoelectric body, and at least one of the thin-film electrodes is divided into a plurality of regions of which an area increases by 2n times (n is a natural number including 0). Thus, a digital speaker in which reverberation or crosstalk between segments is suppressed is obtained.

The presently claimed invention is to provide a package for compact RF signal system, and a method to form the package thereof in order to miniaturize the size of package, improve signal integrity, and reduce manufacturing cost. The package comprises a hybrid substrate with a sandwiched structure, in which the hybrid substrate comprises an upper layer and a lower layer with different dielectric properties being separated by an interposer for improving electrical isolation and mechanical stiffness. Metal layers are formed on the sidewalls of the opening to surround an active component, such that the metal sidewalls together with two ground plates in the upper and lower layers constitute a self-shielding enclosure inside the package to protect the active component.