325 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.

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.

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.

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.

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.

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.