787 results about "Thermal aging" patented technology

A method is presented for estimating an amount of ammonia stored in a urea-based SCR catalyst based on a dynamic model of the catalyst. The model takes into account chemical and physical properties of the catalyst, such as catalyst volume, the number of available ammonia storage cites, adsorption and desorption dynamics, as well as sulfur poisoning, thermal aging, and different catalyst operating temperatures, and generates the estimate based on a measured or estimated amount of NOx in an exhaust gas mixture upstream of the catalyst, an amount of reductant injected into the catalyst to facilitate NOx reduction, and on a measured value of NOx in an exhaust gas mixture downstream of the catalyst. The estimated ammonia storage amount is then used to control the amount of reductant injected into the catalyst to maintain desired ammonia storage amount such that maximum NOx conversion efficiency coupled with minimum ammonia slip are achieved.

A method is presented for estimating an amount of ammonia stored in a urea-based SCR catalyst based on a dynamic model of the catalyst. The model takes into account chemical and physical properties of the catalyst, such as catalyst volume, the number of available ammonia storage cites, adsorption and desorption dynamics, as well as poisoning, thermal aging, and different catalyst operating temperatures, and generates the estimate based on a measured or estimated amount of NOx in an exhaust gas mixture upstream of the catalyst, an amount of reductant injected into the catalyst to facilitate NOx reduction, and on a measured value of NOx in an exhaust gas mixture downstream of the catalyst. The estimated ammonia storage amount is then used to control the amount of reductant injected into the catalyst to maintain desired ammonia storage amount such that maximum NOx conversion efficiency coupled with minimum ammonia slip are achieved.

A method is presented for estimating an amount of ammonia stored in a urea-based SCR catalyst based on a dynamic model of the catalyst. The model takes into account chemical and physical properties of the catalyst, such as catalyst volume, the number of available ammonia storage cites, adsorption and desorption dynamics, as well as poisoning, thermal aging, and different catalyst operating temperatures, and generates the estimate based on a measured or estimated amount of NOx in an exhaust gas mixture upstream of the catalyst, an amount of reductant injected into the catalyst to facilitate NOx reduction, and on a measured value of NOx in an exhaust gas mixture downstream of the catalyst. The estimated ammonia storage amount is then used to control the amount of reductant injected into the catalyst to maintain desired ammonia storage amount such that maximum NOx conversion efficiency coupled with minimum ammonia slip are achieved.

The invention discloses a low-temperature curing high temperature-resistant inorganic/organic hybrid epoxy adhesive and a preparation method thereof, which relate to an inorganic/organic hybrid epoxy adhesive and a preparation method thereof. The invention solves the problems that inorganic/organic hybrid epoxy adhesive prepared by the prior art has poor high-temperature thermal aging resistance and needs high curing temperature. The low-temperature curing high temperature-resistant inorganic/organic hybrid epoxy adhesive is prepared by an epoxy resin, an epoxy resin low-temperature curing agent, a coupling agent, an inorganic active hybrid material and a dispersant. The preparation method comprises the following steps: the epoxy resin, the epoxy resin low-temperature curing agent and the coupling agent are mixed and stirred evenly, and then the inorganic active hybrid material and the dispersant are added into the mixture to be stirred evenly to obtain the low-temperature curing high temperature-resistant inorganic/organic hybrid epoxy adhesive. The low-temperature curing high temperature-resistant inorganic/organic hybrid epoxy adhesive has high high-temperature bonding strength, good high-temperature thermal aging performance and low curing temperature. The low-temperature curing high temperature-resistant inorganic/organic hybrid epoxy adhesive has the advantages of simple production technology, convenient operation and broad application.

Amino alkoxy-modified silsesquioxanes (amino AMS), and/or amino co-AMS compounds that also comprise a mercaptosilane or a blocked mercaptosilane, are excellent adhesives for coating plated or unplated metal wire for adherence of the wire to a rubber stock. The amino AMS and/or the amino/mercaptan co-AMS adhesives can be used with all types of rubber and there is no requirement for the use of special adhesive additives to the rubber vulcanizates, such as, but not limited to, cobalt, resins and high sulfur levels. In particular, the use of amino AMS and/or amino/mercaptan co-AMS compounds as adhesives for bonding wire to rubber also improves the adherence performance of the reinforcements to obtain sufficient bonding that is resistant to degradation over the course of time, especially resistance to thermal aging and/or thermo-oxidizing aging, in particular corrosion in the presence of water.

Acrylate copolymer pressure-sensitive adhesive constructions are described which provide excellent retention of rivet properties. Tenting around rivets is minimized even after undergoing thermal aging while in contact with additive rich films like PVC. This is achieved by the inclusion of a synergistic amount of an N-vinyl lactam monomer and acid monomer with the bulk of the monomers being an alkyl acrylate save and/or methacrylate esters. A concomitant increase in cohesive strength is also achieved which affords good removal characteristics. The use of appropriate adhesive blends is further disclosed which allows retention of these features while also improving cold temperature properties.

Nitrogen oxide storage materials and methods of manufacturing nitrogen oxide storage materials are disclosed. The nitrogen oxide storage materials can be used to manufacture catalytic trap disposed in an exhaust passage of an internal combustion engine which is operated periodically between lean and stoichiometric or rich conditions, for abatement of NO_x in an exhaust gas stream which is generated by the engine. In one embodiment, the nitrogen oxide storage material comprises alkaline earth material supported on ceria particles having a crystallite size of between about 10 and 20 nm and the alkaline earth oxide having a crystallite size of between about 20-40 nm.

The invention discloses an ultraviolet cross-linking EPDM (ethylene propylene diene monomer) rubber cable insulation material and a preparation method thereof. The method is characterized in that: by weight, 100 portions of EPDM rubber, 100 portions to 120 portions of inorganic filling, 0.5 portion to 5.0 portions of ultrasonic initiator, 0.5 portion to 5.0 portions of polyfunctional cross-linking agent, 5.0 portions to 10.0 portions of softener, 0.8 portion to 1.2 portions of silane coupling agent and 0.01 portion to 1.0 portion of complex antioxidant are evenly mixed and extruded at the temperature of 100 DEG C to 150 DEG C, thereby obtaining the ultraviolet cross-linking EPDM rubber cable insulation material; then the wire core is fused and extruded coating to form an insulation layer or a protective coating; and ultraviolet cross linking is carried out under 200nm to 400nm of wave length and 400mW/cm<2> to 2000mW/cm<2> of light intensity. The cable insulation material has tensile strength of larger than 6.5MPa, elongation at break of higher than 300 percent and volume resistivity of higher 10<12>Omega question mark cm, and can pass a thermal aging test under the temperature of 135 DEG C for 168h.

A disclosed oil-resistant cold-resistant ultraviolet-proofpolyvinyl chloride/nitrile rubber composite cable material is prepared from the following raw materials in parts by weight: 60-80 parts of SG-2 type polyethylene, 20-30 parts of POE, 30-50 parts of nitrile rubber, 15-20 parts of fluorubber, 10-15 parts of dioctyl phthalate, 5-10 parts of di(butylcarbitol)adipate, 0.5-1 part of dicumyl peroxide, 2-3 parts of triallyl isocyanurate, 1-2 parts of 2-mercaptobenzimidazole, 4-8 parts of titanium dioxide, 5-10 parts of paraffin oil, 2-3 parts of zinc oxide, 4-8 parts of microcrystalline paraffin and the like. The cable materials of the invention ahs excellent thermoset rubber apparence and thermoplastic elastomer characteristics, and good mechanical properties and low-temperature flexibility; the long-term suitable operation temperature is -40 DEG C to 105 DEG C; the cable material is capable of retarding flame, resisting oil, resisting acid and base, resisting wear, resisting weather, resisting ozone, resisting thermal aging and resisting ultraviolet ray, and is applicable as high-oil-resistance weatherable cable sheath materials.

A curable silicone composition includes (A) a polydiorganosiloxane having an average, per molecule, of at least two aliphatically unsaturated organic groups and at least one aromatic group; (B) a branched polyorganosiloxane having an average, per molecule, of at least one aliphatically unsaturated organic group and at least one aromatic group; (C) a polyorganohydrogensiloxane having an average per molecule of at least two silicon-bonded hydrogen atoms and at least one aromatic group, (D) a hydrosilylation catalyst, and (E) a silylated acetylenic inhibitor. The curable silicone composition cures to form a cured silicone resin having a refractive index >1.40. The curable silicone composition cures by heating to form a cured silicone resin with an optical transparency >95% at a thickness of 2.0 mm or less at 400 nm wavelength after thermal aging by heating at 200° C. for 14 days.

The invention discloses a finite-element-based machine tool important part residual stress multi-process continuous modeling simulation method. The method comprises the steps of important part model simplification and casting system three-dimensional modeling, important part casting process finite element simulation, important part casting stress field coefficient correction, important part machining residual stress simulation, and important part thermal aging process residual stress finite element simulation. Accordingly, multi-process continuous simulation of casting, cutting and thermal aging processes are implemented; a blind hole method test measurement value serves as a reference, a stress value of an important part casting simulation corresponding point is extracted, a test value ofthe corresponding point and a correction coefficient with the minimum simulation value error are fitted by applying a least square method through MATLAB, and then the whole casting stress field datais corrected; the calculation accuracy of finite element simulation is improved, and the technical purpose that the casting stress field obtained after a beam is corrected is guided into an ABAQUS accurately is achieved.

The invention discloses a high-polymer waterproof coiled material hot-melt pressure-sensitive adhesive and a preparation method thereof. The hot-melt pressure-sensitive adhesive comprises the following components in parts by mass: 30-200 parts of elastomer composition, 40-100 parts of tackifying resin, 20-70 parts of plasticizer, 0.3-5 parts of stabilizer and 0.1-3 parts of additive. The elastomer composition is selected from SIS (styrene-isoprene-styrene)/SEPS (styrene-ethylene/propylene-styrene), SIS/SBS (styrene-butadiene-styrene), and/or SBS/SEBS (styrene-ethylene-butadiene-styrene). The mass ratio of the two components in the elastic composition is 1-20; the styrene in the SIS in the elastic composition accounts for 15-30 wt%, the styrene in the SEPS accounts for 10-30 wt%, the styrene in the SBS accounts for 20-50 wt%, and the styrene in the SEBS accounts for 10-40 wt%. The hot-melt pressure-sensitive adhesive has the characteristics of excellent ultraviolet aging resistance, favorable thermal aging resistance, high peel strength, simple technique and low cost.

The invention relates to a functional nano titanium dioxide grafted with antioxidant molecules on the surface. The surface of the nano-titanium dioxide is coated with silica; an aminosilane coupling agent reacts with the silica and is grafted with an antioxidant. Meanwhile, the invention also relates to a preparation method of the functional nano-titanium dioxide grafted with the antioxidant molecules on the surface. According to the preparation method disclosed by the invention, the surface of the nano-titanium dioxide is coated with a layer of the silica and then the aminosilane coupling agent is used for bridging, and a hindered phenol antioxidant is chemically grafted onto functional nano-titanium dioxide particles. According to the functional nano-titanium dioxide grafted with the antioxidant on the surface, disclosed by the invention, light weathering property and thermal aging resistance of a polymer can be simultaneously improved; in addition, an additive has the advantages ofno toxicity, low possibility of seeping and high stability.

The invention provides a method for detecting the service life of a cable. The method is used for detecting the service life of the cable respectively in three different detection ways as follows: measuring an isothermal relaxation current in a cable depolarization process, and calculating an aging factor to obtain a first service life value; carrying out thermal aging treatment on a cable sample, and measuring the thermal aging failure time and the corresponding aging temperature to obtain a second service life value of the measured cable under the rated working temperature; applying a breakdown voltage to the measured cable to obtain a third service life value; and accurately determining the average service life of the measured cable according to the three measured service life values. As the influence of electric polarization, thermal aging and voltage breakdown on the service life of the cable is respectively considered by parameters involved in detection, the measured service life of the cable is more accurate.

The invention discloses an evaluation method for a paper oil insulation aging state through characteristic parameters based on time domain dielectric response. The evaluation method for the paper oil insulation aging state through the characteristic parameters based on the time domain dielectric response comprises the steps of measuring a polarization and depolarization current of a system, simulating an equivalent circuit of the polarization and depolarization current, calculating circuit parameters of an equivalent circuit model to obtain a depolarization current, smoothing the depolarization current and fitting the depolarization current to obtain depolarization power quantity, building a function relationship of aging time and characteristic parameters of the depolarization power quantity, integrating the relationship between the polymerization degree changing rule and the characteristic parameters of the depolarization power quantity through combining a first order dynamical model of a polymerization degree changing rule of mineral paper oil insulation acceleration thermal aging. By the utilization of the evaluation method for the paper oil insulation aging state through the characteristic parameters based on the time domain dielectric response, the operation is simple, sensitivity is high, and the evaluation method for the paper oil insulation aging state through the characteristic parameters based on the time domain dielectric response is suitable for the use of engineering.

The invention provides a thermal aging-resistant polyurethane elastomer. The polyurethane elastomer is formed by mixing a polyurethane prepolymer, a chain extension cross-linking agent and auxiliaries, pouring, demolding and vulcanizing, wherein the polyurethane prepolymer is formed by stirring polymer diol, diisocyanate and a catalyst at the temperature of 50-100 DEG C, and the raw materials respectively comprise the following components in percentage by weight: 47-60wt% of polymer diol, 15-30wt% of diisocyanate, 0-4wt% of catalyst, 8-17wt% of chain extension cross-linking agent and 1-6wt% of auxiliaries. The invention simultaneously provides a preparation method of the thermal aging-resistant polyurethane elastomer. The method has the advantages of simple process and low equipment cost, and the produced polyurethane elastomer has excellent thermal aging resistance.

The invention is directed to improved conductive adhesives for solder-free interconnections in microelectronic assembly processes such as for chip carrier-to-substrate attachment. These adhesives are characterized by low tensile modulus, low resistivity, high adhesion strength, and durability of these properties during reliability stress conditions of thermal shock, thermal aging, and temperature/humidity (85.degree. C./85%) exposure of the assembled devices. The adhesives contain a homogeneous solution of a siloxane containing epoxide, a curing agent, a curing catalyst and an organic polymeric or oligomeric additive. A conductive filler is added to the solution forming the filler. Preferred fillers are Ag coated with Pd and Ag coated with Au.

The invention provides a rubber composite used for rubber framework oil seal and a preparation method thereof. The rubber composite contains(based on weight portions) 100 portions of fluorubber26, 5-6 portions of acid absorber magnesia, 5-6 portions of calcium hydroxide, 9-1 portions of strengthening agent black carbon, 19-20 portions of barium sulphate, 17-19 portions of iron oxide red, 2-3 portions of process additive, 1.5-2 portions of curing ingredient bisphenol AF, and 0.6-0.8 portions of accelerant BPP. The rubber composite improves the tension strength, extensibility, tear resistance, self-lubricating effect, compressive deformation resistance and thermal aging resistance of the rubber framework, makes the rubber framework good in medium resistance and prolongs the service life of the rubber framework oil seal. Meanwhile, the method is simple in process, reasonable in mixture ratio and reduces preparation cost and defective index.

A solder alloy includes Sn, optional Ag, Cu, and Al wherein the alloy composition is controlled to provide a strong, impact-and thermal aging-resistant solder joint that has beneficial microstructural features and is substantially devoid of Ag₃Sn blades.

The invention provides tinned carbon nanomaterial reinforced compound solder alloy and solder paste thereof. The tinned carbon nanomaterial reinforced compound solder alloy comprises, by weight, 84-95 parts of tin-based solder, 0.01-0.2 part of carbon nanomaterials and 5-15 parts of soldering flux. By the adoption of the technical scheme, the creep resistance, electrical conductivity and thermal aging resistance of soldered dots generated by the tinned carbon nanomaterial reinforced compound solder alloy and the solder paste thereof are improved. The carbon nanomaterials in the prepared solder paste are uniform in distribution, the process is simple and reliable, adaptability is high, and cost is low.

The invention discloses a uv photocrosslinking halogen free flame retarding ethylene propylene diene monomer (EPDM) cable material and a preparation method thereof. The method is characterized by uniformly mixing 100 parts of EPDM, 100-150 parts of metal hydroxid, 0.5-5.0 parts of uv-light initiator, 0.5-5.0 parts of polyfunctional group cross linker, 5.0-10.0 parts of softener and 0.01-1.0 part of compound antioxidant and consequently extruding the mixture into platy material, namely, the photocrosslinking EPDM cable material; then the EPDM cable material is covered on a cable electric lead core by melt extrusion to form an insulating layer or a sheathing layer and subsequently is radiated by uv light with the dominant wavelength of 200-400nm and the light intensity of 400-4000mW/cm for crosslinking; and the tensile strength of the obtained cable insulating layer or the sheathing layer is more than 7.0MPa, the elongation at break is more than 350 percent and the electric volume resistivity is more tan 10Omega.cm. The cable material can pass the thermal aging test at the temperature of 135 DEG C for 168h.

The invention relates to an expanding damping adhesive with good damp heat resistance ageing performance, which belongs to the technical field of the expanding damping adhesive and mainly solves the problems that the damp heat resistance aging performance of the existing expanding damping adhesive is not good enough so as to affect service life of the expanding ageing performance. The expanding damping adhesive is mainly characterized by comprising the following components, by weight, 10-40 parts of liquid polybutadiene, 0-10 parts of solid rubber, 0-20 parts of softener, 0-10 parts of tackifier, 0-10 parts of sulphur, 0-10 parts of accelerating agent, 0.1-3 parts of antioxygen, 0.1-10 parts of active agent, 0-3 parts of foaming agent and 10-50 parts of filler. The expanding damping adhesive has good strength keeping rate after damp heat ageing and long service life, is widely used for adhesion and filling between an outer plate and a strengthening beam of an auto-body panel of a welding line, and has buffering and damping effects.