333 results about "Tan delta" patented technology

The invention is directed to compositions comprising an elastomer component and a propylene component, and in which the elastomer component comprises at least one ethylene / α-olefin polymer, optionally containing a diene, and the polypropylene component comprises at least one branched polypropylene. Preferably, the elastomer component has a melt tan delta between about 0.7 and about 8, as measured by parallel plate rheometer at 0.1 rad / sec, 190° C., and 15 percent strain; and the ratio of the “melt tan delta of the elastomer component” to the “melt tan delta of the propylene component” is from 0.5 to 4. The invention also provides for method of making such compositions, and to low gloss articles prepared from the same. The inventive compositions are particularly suitable for fabricating thermoformed sheeting with reduced gloss.

A toner, particularly a color toner suitable for full-color image formation through a substantially oil-less heat-pressure fixing device, is formed from at least a binder resin, a colorant and a wax. The toner has viscoelasticity including: a storage modulus at 80° C. (G'80) in a range of 1x106-1x1010 dN / m2, storage moduli at temperatures of 120-180° C. (G'120-180) in a range of 5x103-1x106 dN / m2, and loss tangents (tan delta=G'' / G' as a ratio between G'' (loss modulus) and G' (storage molecules)) including a loss tangent at 180° C. (tan delta180) and a minimum of loss tangents over a temperature range of 120-180 ° C. (tan deltamin) satisfying 1<=tan delta180 / tan deltamin. The toner further exhibits a thermal behavior providing a heat-absorption curve according to differential scanning calorimetry (DSC) showing a maximum heat-absorption peak temperature in a range of 50-110° C. in a temperature range of 30-200° C.

A method for determining reliability and a remaining time before failure with statistical confidence for a motor system includes acquiring historical motor data in a computer system, obtaining operational parameter data, uploading the operational parameter data to the computer system, performing failure analysis, developing a causal network, and performing an integrated causal network and reliability analysis of the motor system. The historical motor data corresponds to the motor system. The operational parameter data is obtained from sensors at the motor system. The sensors include a tan delta sensor. The failure analysis is performed based on a composite of reliability probability distributions corresponding to predetermined sub-populations of historical motor system failure causes. The causal network is developed for modeling reliability of one or more motor system components and assessing motor system component condition based on the causal network. Results from the performing failure analysis are integrated with results from the assessing motor system component condition based on the causal network to compute a quantitative value for a time remaining before failure with an ascertained statistical confidence.

Disclosed is a melt-blended thermoplastic composition including: A) a polyamide composition including a) 55 to 90 weight percent semi-crystalline semi-aromatic copolyamide; wherein the semi-aromatic copolyamide has a DMA tan delta peak value of greater than or equal to 0.23; and heat of fusion of at least 20 J / g and b) 10 to 45 weight percent aliphatic homopolyamide; wherein the aliphatic homopolyamide has a DMA tan delta peak value of less than or equal to 0.21; and heat of fusion of at least 30 J / g; B) 0 to 45 weight percent polymeric toughener; C) 0 to 20 weight percent plasticizer; and D) 0 to 45 weight percent reinforcing agent; wherein said melt-blend composition has a glass transition and has a tan delta peak (E″ / E′) value of 0.21 or lower at said glass transition. Further disclosed herein is a method for providing the melt-blended thermoplastic composition.

The invention discloses a high-flexible polymer matrix composite membrane with high energy density and a preparation method thereof. The composite membrane is composed of a polymer matrix and core-shell structured nano-fibre dispersed in the polymer matrix; the core layer of the core-shell structured nano-fibre is ceramic fibre; the shell layer is an organic matter coated layer, wherein the mass percentage of the polymer matrix is 50-95%; and the mass percentage of the core-shell structured nano-fibre is 5-50%. The polymer matrix and the core-shell structured nano-fibre are composited into the membrane by adopting a solution blending and tape casting method or a bidirectional membrane pulling method, so that a flexible polymer matrix composite material having the advantages of being good in dielectric property, high in breakdown field strength and high in energy density is obtained. The dielectric constant of the composite material can be modulated to 10-40 by adjusting the content of nano ceramic fibre; simultaneously, the dielectric loss Tan delta is kept to be less than 5%, the breakdown field strength is more than 210 kV / mm, and the energy density is 2-6 kJ / L; and the composite material is a material which can be used for capacitors and high power static energy storage.

An automotive part containing at least one component formed from a composition comprising the following: (i) a crystalline, isotactic propylene homopolymer, (ii) an ethylene / α-olefin elastomeric impact modifier, and (iii) a reinforcing grade of filler, for example, talc. The crystalline isotactic propylene homopolymer has a flex modulus of greater than about 1930 MPa and a heat deflection temperature (HDT) of greater than about 100° C.; the ethylene / α-olefin interpolymer has a Tg of less than about −30° C., and a tan delta measured at 0.1 radians / s at 190° C. of less than about 2; and the filler has a HDT reinforcing efficiency of at least about 2. The automotive part has an HDT of greater than about 100° C. and a flex modulus of greater than about 1930 MPa.

The subject invention provides a viscoelastic polyurethane foam having a density of from one to twenty pounds per cubic foot. The foam is formed from a composition that is a reaction product of an isocyanate component (A), a first polyether polyol (B), a second polyether polyol (C), and a chain extender (D). The chain extender (D) has a backbone chain with from two to eight carbon atoms and has a weight-average molecular weight of less than 1,000 and is present in an amount of from 5 to 50 parts by weight based on 100 parts by weight of the composition. The viscoelastic polyurethane foam a first glass transition temperature greater than zero and a second glass transition temperature less than zero and having a tan delta peak ratio of the first glass transition temperature to the second glass transition temperature less than 2.2.

The invention relates to the technical field of insulation detection for high voltage equipment, in particular to an insulation detection method for a high voltage bushing based on frequency domain dielectric spectroscopy. The method comprises the step that a frequency domain dielectric spectroscopy based test is adopted to detect insulation of the bushing. With the adoption of the method, an influence of a Garton effect on measuring of tan delta at low voltage is avoided; a real tan delta frequency curve of the bushing at 0.001-1000Hz and at the low voltage is acquired and used for judging an insulation state of the bushing; and compared with the traditional bushing adopting a single 50Hz frequency point tan delta to judge the insulation state of the bushing, the judgment accuracy is improved. The test and a measuring device of the method are simple in structure and easy to operate, and the difficulty that the test and the device are difficult to operate when the measuring of the tan delta of the bushing is conducted at 0.001-1000Hz and at high voltage is solved.

The invention provides a molded composition having improved noise damping properties, made of a blend of a soft thermoplastic polyether elastomer and a hard polyester resin reinforced with a fibrous or particulate filler, the molded composition having an inhomogeneous structure comprising a surface part which is rich in elastomer and depleted in the polyester resin and the reinforcing filler compared to its inner part, obtained by monocomponent injection molding of a blend of the soft and the hard polyester resin wherein only the polyester resin contains the reinforcing particulate filler. The molded composition has a flex modulus Fm in the range 0.5 to 10 GPa, and maintains a sufficient minimum tan delta damping factor t_ over a temperature range of −50° C. to 170° C.

A pneumatic radial tire is provided which comprises an under-belt pad (3) provided circumferentially between edge portions of a belt (1) and a carcass in a shoulder portion thereof, the under-belt pad (3) being of a rubber compound containing 10 to 60 parts by weight of carbon black and 3 to 30 parts by weight of silica with a total amount of carbon black and silica being 20 to 65 parts by weight, 2 to 5 parts by weight of sulfur and 0.5 to 3 parts by weight of resorcin or a resorcin derivative all relative to 100 parts by weight of rubber, and 0.5 to 2 parts by weight of hexamethylene tetratine or a melamine derivative as a methylene donor relative to 1 part by weight of the resorcin or the resorcin derivative, and having a dynamic viscoelasticity E' of 5 MPa to 10 MPa, a loss tangent tan delta of 0.10 to 0.18 and a 300% modulus of 11 MPa to 15 MPa.

A toner formed of at least a binder resin, a colorant, a charge control agent and a wax, is provided with a uniform state of dispersion of the wax and good balance of low-temperature fixability and anti-high-temperature offset characteristic, while exhibiting good developing performances over wide environmental conditions. The toner is characterized in that (a) the binder resin comprises a hybrid resin component having a polyester unit and a vinyl polymer unit, (b) the toner exhibits a loss tangent (tan delta) of 1.0 at a temperature in a range of 80-160° C., and (c) the toner provides a DSC curve showing a heat-absorption peak in a temperature range of 85-130° C. on temperature increase as measured according to differential scanning calorimetry (DSC).

The invention introduces an epoxy resin-based piezoelectric and composite damping material and a preparation method thereof, which comprises the following materials by weight portion: 100 portions of epoxy resin, 30 portions to 220 portions of piezoelectric ceramic powder, 0.5 portion to 5 portions of graphitized carbon black and 30 portions to 120 portions of curing agent. After being mixed, dispersed and added with the curing agent to be evenly blended and then poured, cured and shaped, the piezoelectric and composite material can be polarized in an HVDC oil-bath electric field and has good damping property (tan Delta is not less than 0.3) in a wide-temperature range (10 to 100 DEG C) and can also be applied in projects as free damping material as well as in an intelligent vibration and noise reduction system. In addition, the piezoelectric and composite material can be made into damping paint, putty, slurry and potting adhesive and poured into various section materials to be used in vibration and noise reduction projects in the fields such as vehicles, industrial machinery, civil construction, household appliances, precision instruments, military equipment, etc.

The invention provides an antenna module-use magnetic core member capable of improving a communication distance without increasing a module thickness, and an antenna module and a portable information terminal provided with this. An antenna module (1) comprising a sheet-formed magnetic core member (4) layered on a looped antenna coil-formed antenna substrate (2), wherein a magnetic core member (4) having a performance index, expressed by mu' * Q, of 300 or higher is used when Q is a reciprocal of a loss factor (tan delta=mu'' / mu') expressed by the real part mu' and the imaginary part mu'' of a complex permeability at a frequency used.

Encapsulated particles and methods for manufacturing encapsulated particles and structures are described. Such particles may have a length no greater than 40 nm, and include at least one material selected from the group consisting of ferromagnetic materials and ferrimagnetic materials. A polymeric encapsulant surrounds the particle, the polymeric encapsulant including a phase-separated block copolymer including a glassy first phase and a rubbery second phase, the glassy first phase positioned between the particle and the second rubbery phase. The glassy first phase includes a hydrophobic copolymer having a glass transition temperature of at least 50° C. The rubbery second phase includes a polymer having at least one of (i) a glass transition temperature of no greater than 30° C., and (ii) a tan delta peak maximum of no greater than 30° C. Other embodiments are described and claimed.

The present invention is directed to an adhesive composition comprising a crosslinkable acrylic copolymer, a multi-functionalized crosslinkable oligomer and a photoinitiator wherein the partially cured composition exhibits excellent wet out characteristics as reflected in a tan delta value of at least 0.4, preferably greater than 0.5, more preferable greater than 0.6 as measured at 20° C. resulting from a first curing stage, and the fully cured composition exhibits an improved stiffness and temperature resistance as reflected in a storage elastic modulus of at least 175,000 Pa at 20° C. and a shear adhesion failure temperature of at least 425° F. (218.3° C.) at 1 Kg / in2 (0.155 Kg / cm2), respectively, which result from a second sequential curing stage.

There is provided a pneumatic tire having an aspect ratio of not less than 60 and considerably improving run flat durability as compared with the conventional type of the run flat tire, wherein at least one cushion rubber layer having a loss tangent lower than a loss tangent (tan delta) of a coating rubber for cords of a carcass ply is arranged between an end portion of a belt and a reinforcing rubber layer in a shoulder region and between mutually adjacent tire constitutional members. And also, when the carcass is comprised of plural plies, at least one ply is separated off in a zone beneath the belt, whereby the ride comfort against vibrations can be more improved.

The invention provides a molded composition having improved noise damping properties, made of a blend of a soft thermoplastic polyether elastomer and a hard polyester resin reinforced with a fibrous or particulate filler, the molded composition having an inhomogeneous structure comprising a surface part which is rich in elastomer and depleted in the polyester resin and the reinforcing filler compared to its inner part, obtained by monocomponent injection molding of a blend of the soft and the hard polyester resin wherein only the polyester resin contains the reinforcing particulate filler. The molded composition has a flex modulus Fm in the range 0.5 to 10 GPa, and maintains a sufficient minimum tan delta damping factor t_ over a temperature range of -50.degree. C. to 170.degree. C.

The invention relates to a wide-temperature low-distortion mangan zinc ferrite applicable to a broadband network transformer and a preparation method thereof. The mangan zinc ferrite mainly comprises the following components: 52.0 to 53.0 mol percent of iron oxide computed by Fe2O3, 21.0 to 23.0 mol percent of zinc oxide computed by ZnO, and the balance of trimanganese tetroxide, and also comprises the following auxiliary components in percentage by weight (wt %) computed by respective standard substance CaCO3, SiO2, V2O5 and Co2O3: 0.03 to 0.04 of CaCO3, 0.005 to 0.01 of SiO2, 0.01 to 0.03 of V2O5 and 0.03 to 0.1 of Co2O3. The mangan zinc ferrite is prepared by an oxide method and sintered under the condition of bell-type furnace densification. A product has higher initial magnetic permeability mu i, low relative loss factor tan delta / mu i, and wide-temperature low-magnetic hysteresis coefficient eta B (-40 to 85 DEG C), is capable of reducing waveform distortion, reducing transmission errors and prolonging transmission distance in the process of transmitting signals, and meets the requirement of the application in outdoor severe environment.

The invention relates to a tire having a circumferential tread of a cap / base configuration composed of an outer tread rubber cap layer with a running surface of the tread and an underlying tread rubber base layer, wherein said tread cap layer is composed of two longitudinal adjacent zones, namely a primary tread cap zone and a minor lateral outboard control element (zone). The primary tread cap zone and the lateral outboard tread cap element provide a significant gradation of cold dynamic storage moduli (G′) at −25° C. and hot tan delta values at 100° C., yet similar warm dynamic storage moduli (G′) at 60° C. The primary tread cap zone and lateral outboard control tread cap element are load bearing in the sense of extending from the running surface of the tread radially inward to the unitary (non-zoned) tread base rubber layer. The zoned rubber tread cap layer and unitary rubber tread base layer are an integral tread composite in a sense of being co-extruded. In one aspect of the invention, the primary tread cap zone rubber composition is silica-rich and the lateral, outboard element rubber composition is carbon black-rich and which furthermore provide a gradation of filler reinforcement content; provide a gradation of silica to carbon black ratio and provide a gradation of cis 1,4-polybutadiene rubber content.

Provided is a biaxially-oriented polypropylene film for a capacitor, metal evaporated film using the capacitor and cast raw sheet for obtaining the same. The biaxially-oriented polypropylene film for a capacitor is obtained by adding 92-95% of addition resin B in a quantity ([mmmm]) of 1-20 mass% in relation to the total mass of the resin mixture, in a main resin A with the internal compensation five unit group percentage ([mmmm]). The film is a biaxially-oriented polypropylene film composed of more than two kinds of different stereoregularity in the isotactic polypropylene resin with molecular properties. The temperature of a mechanical dispersion peak (crystal dispersion) (tan delta ) in a temperature loss tangent curve, which is obtained by a dynamic solid viscoelasticity measurement at a heating rate of 2[deg] C / minutes with a frequency of 0.5 Hz, is >= 80[deg] C.

The invention relates to the dielectric substrate characteristic measurement field and especially discloses a dielectric substrate measurement apparatus based on a multi-resonant waveguide substrate integration vibration cavity method. The apparatus comprises a standard W frequency band metal feed waveguide and N resonant cavities. The apparatus is characterized in that the shape of the N resonant cavities is square and the N resonant cavities are arranged in a slotted shape from left to right; resonant frequencies are successively decreased according to a fixed frequency interval. The measurement method is characterized in that a vector network analyzer is used and is connected to a feed port of a standard metal waveguide through coaxial feed; according to the recorded S parameter data on the vector network analyzer and Smith chart data, a no-load resonant frequency f110 is calculated through a formula; and then simulation software HFSS is used to carry out intrinsic model simulation so as to acquire values of dielectric constants epsilon r and tan delta of the dielectric from the f110. By using the apparatus and the method in the invention, high precision measurement can be performed on the dielectric constant of the dielectric substrate and a loss tangent in a wide frequency band.

Provided are: a polishing pad, which improves the problem of scratches that are produced in cases where conventional hard (dry) polishing pads are used, which has having excellent polishing rate and polishing uniformity, and which is applicable not only to primary polishing but also to final polishing; and a method for producing the polishing pad. A polishing pad for semiconductor device polishing, which comprises a polishing layer having a polyurethane polyurea resin molded body that contains generally spherical cells. This polishing pad for semiconductor device polishing is characterized in that: the polyurethane polyurea resin molded body has a closed cell ratio of 60-98%; the ratio of the loss modulus (E") to the storage modulus (E'), namely loss modulus / storage modulus (tan delta) of the polyurethane polyurea resin molded body is 0.15-0.30; the storage modulus (E') is 1-100 MPa; and the polyurethane polyurea resin molded body has a density (D) of 0.4-0.8 g / cm<3>.

The invention provides low-temperature sintered lead-free microwave dielectric ceramic and a preparation method thereof. By adopting the method, continuous adjustable dielectric constant is realized by regulating the Mg / Ca ratio of [Cax, Mg(1-x)]TiO3 powder which serves as a base material; low-temperature sintering of the ceramic material at 800-900 DEG C is realized by adding CaO-Al2O3-B2O3-SiO2 microcrystalline glass. The method comprises the following steps: firstly, synthesizing [Cax, Mg(1-x)]TiO3 ceramic powder, and synthesizing CaO-Al2O3-B2O3-SiO2 microcrystalline glass; then, performing ball-milling, dosing, tape-casting, molding and batching out, sintering and annealing to obtain a low-consumption multi-layer ceramic dielectric material with excellent performance. According to the method, the microcrystalline glass / ceramic green-compact is molded by adopting thick film tape-casting, and multiple layers of the green compact are laminated and subjected to low-temperature sintering to prepare a ceramic substrate, so that the dielectric loss can be reduced, the dielectric constant is adjustable in a range of 9-35, tan delta is less than 0.0002 under 10MHz, and tan delta is less than 0.0015 under 1-10GHz; low-temperature sintering is realized, and industrial production can be realized by combining with an Ag-Pd electrode.

The invention provides a barium titanate-based lead-free high-voltage ceramic capacitor material, which takes barium titanate, bismuth titanate, strontium titanate and calcium titanate as raw materials. After the materials are mixed, polyvinyl alcohol is added, the obtained mixture is pressed and formed, and the obtained product is sintered under about 1220 DEG C to obtain the high-pressure lead-free ceramic capacitor material. The voltage resistance of the capacitor material sintered by using the ceramic material formula is improved to 16.9kv / mm, the dielectric constant (Xir) is equal to 2089, and the dielectric loss (tan Delta) is equal to 0.0006 under 1MHz AC working current.

An on-line ultrahigh-voltage line power transformer test method includes the following specific steps: measuring off-line 'raw data' and on-line 'basic data'; measuring the insulation resistance R of windings; analyzing the insulation resistance R of the windings; measuring the active current I Rho, reactive current I Kappa and dielectric dissipation factor tan Delta of each winding; analyzing the dielectric dissipation factor tan Delta; measuring the capacitance C of capacitance type bushings; analyzing the capacitance C of the capacitance type bushings; measuring the leakage current I of the windings; and analyzing the leakage current I of the windings. The on-line ultrahigh-voltage line power transformer test method has the advantages that the measurement result is accurate, the safety of operators can be guaranteed, equipment injuries can be prevented, and safety is good.