44results about How to "Improve PTC Strength" patented technology

The invention relates to a low-temperature PTC conducting composition, a PTC over-current protection device and a manufacturing method of the PTC over-current protection device. The low-temperature PTC conducting composition comprises, by weight, 40%-55% of organic polymer, 40%-55% of conducting carbon black and 1%-10% of voltage-resistant reinforcing filler. The PTC over-current protection device comprises the low-temperature PTC conducting composition. The PTC over-current protection device has an operating temperature lower than 80 DEG C, high PTC strength and good resistance stability, thereby being capable of achieving good over-current and over-temperature protection for circuits in a low-temperature environment.

The invention relates to a high-temperature resistant PTC electroconductive composition, which comprises 20 to 70 percent of organic polymers, 25 to 75 percent of electroconductive filler, 1 to 30 percent of inorganic filler and 0.1 to 10 percent of additive, wherein the preferred melting point of the organic polymers is more than 150 DEG C; the organic polymers are one or more crystalline or semi-crystalline polymers and made of one or more of nylon 11, nylon 12, polyvinylidene fluoride, soluble poly(tetrafluoroethylene), ethylene-tetrafluoroethylene copolymers, perfluoroethylene-propylene, ethylene-chlorotrifluoroethylene and copolymers thereof. The invention also provides a high-temperature resistant PTC device containing the composition and a manufacturing method thereof. The high-temperature resistant PTC device containing the composition has low resistance, high PTC strength and superior resistance stability, so that the high-temperature resistant PTC device can be used for overcurrent protection of circuits in high-temperature environments such as automobile motors and the like. Moreover, the high-temperature resistant PTC device is simple and convenient to manufacture and has high efficiency.

The invention relates to a composite PTC (positive temperature coefficient) material for normal temperature heat control. The material comprises the following substances of graphite powder / carbon black, paraffin / alkane substance, and low-density polyethylene. A method for preparing the composite PTC material comprises the following steps: melting and mixing the paraffin or the alkane substance and the low-density polyethylene under the temperature of 130-170 DEG C and a vacuum condition, and uniformly stirring the paraffin or the alkane substance and the low-density polyethylene; then adding the graphite powder or the carbon black, and uniformly stirring and mixing the graphite powder or the carbon black under the temperature of 130-170 DEG C and the vacuum condition to obtain a mixture; putting the mixture into a mold for compression molding, and cooling the mixture to room temperature to obtain the rod-type composite PTC material for the normal temperature heat control. The Curie temperature, at which a PTC effect can be achieved, of the material disclosed by the invention is -10 to 40 DEG C and slightly lower than the melting point of a blended substrate; the material is higher in PTC strength, better eliminates an NTC (negative temperature coefficient) effect and can be applied to active temperature control of electronic appliances and other fields of normal temperature heat control; the main defect that the Curie temperature of the conventional PTC material is not in a normal temperature section is overcome.

The invention relates to a polymer-based PTC (positive temperature coefficient) thermistor composite material, in particular to a graphene / high-density polyethylene PTC thermistor composite material and a preparation method thereof, and belongs to the field of high molecular composite materials. The composite material comprises a graphene conductive filler and a high-density polyethylene base body, wherein the weight percentage of the graphene in the components of the PTC thermistor composite material is 1%-10%. The preparation method comprises the following steps: grinding high-density polyethylene particles into powder by a high-speed universal grinder, mixing the powder with the graphene, performing melt blending through a torque rheometer, and finally performing hot-pressing by a press vulcanizer to prepare the graphene / high-density polyethylene PTC thermistor composite material. The polymer-based composite material taking the graphene as the conductive filler has the advantages of low initial resistance, high response speed, high PTC intensity, good circularity and the like, and can lay a foundation for an application of the graphene to a thermistor and indicate a direction for the application of the graphene.

A PCT thermistor comprises a substrate and two tinsel-shaped electrodes which are combined with two surfaces of the substrate. The substrate is made of the following components in weight percentage: 28-55% of high-polymer material; 22-32% of conductive filling material; 13-46% of auxiliary filling material; and 1-5% of auxiliary agent in processing. The high-polymer material is obtained through mixing one or multiple materials selected from: polyethylene, polypropylene, maleic anhydride grafted polyethylene, ethane-vinyl acetate copolymer, ethane-acrylic acid copolymer, polyvinylidene fluoride, polycaprolactam, polyhexamethylene adipamide, polydecamethylene sebacamide and polyundecylamide. The auxiliary agent in processing is one component or a mixture of multiple components selected from: an anti-oxidant, a coupling agent, a cross-linking agent and a sensitized cross-linking agent. The sensitized cross-linking agent is one component or multiple components selected from the unsaturated compounds of multiple functional groups with higher decomposition temperature. The PTC thermistor of the invention has the following advantages: high strength, and high resistance for multiple timesof large current impact.

The invention discloses a method to make metal particle modification carbon black making conductive macromolecule compounding material that includes the following steps; adding the carbon black into H(AuCl) solution that the thickness aurum iron is 150ppm-250ppm, whisking, filtering the carbon black and washing, drying to gain the carbon black that the surface is adsorbed aurum iron; putting the carbon black into NaBH solution, whisking and filtering, washing, drying to gain the carbon black that has aurum particle adsorbed on the surface; mixing the carbon black with high density polyethylene, devoting into Banbury mixer, milling for 12-18 minutes in 160-180 degree centigrade. The invention improves the PTC intension of the conductive macromolecule compound material.

The invention relates to a method for preparing a composite conductive polyethylene carbon black material with improved positive temperature coefficient performance. The method comprises the following steps of: (1) preparing a hyper dispersant from 12-oxystearic acid, an antioxidant, a catalyst, dimethylbenzene and the like; (2) preparing modified carbon black from carbon black and a titanate hyper dispersant or a phosphate hyper dispersant or a mixture of the titanate hyper dispersant and the phosphate hyper dispersant; and (3) preparing the composite conductive polyethylene carbon black material from high-density polyethylene, low-density polyethylene, the modified carbon black, the antioxidant and the like. The composite conductive polyethylene carbon black material provided by the invention improves the interaction between a conductive filler and a high molecular matrix, effectively inhibits the agglomeration and the position offset of carbon black in the matrix, increases the PTC(Positive Temperature Coefficient) strength, retards the NTC (Negative Temperature Coefficient) effect, and increases the stability of PTC effect in repeated heating cycle. The method has simple process and low cost, basically causes no pollution to the environment and is convenient to popularize and apply widely.

The invention discloses a PTC (Positive Temperature Coefficient) high polymer heating material for a self-limiting temperature electric tracing band, which is prepared from the following raw materials in percentage by weight: 5 to 9 percent of metallocene polyethylene, 65 to 70 percent of high-density polyethylene, 6 to 10 percent of vinyl copolymer thermoplastic elastomer, 1.5 to 2.5 percent of carbon fibers, 15 to 25 percent of carbon black, 0.25 to 0.35 percent of benzotriazole light stabilizer, 0.10 to 0.20 percent of hindered phenol antioxygen, 0.10 to 0.20 percent of decabromodiphenylethane, 0.10 to 0.20 percent of diisooctyl ortho-phthalate, 0.10 to 0.20 percent of dicumyl peroxide and 0.05 to 0.15 percent of nucleating transparent agent zc-3. According to the invention, the elasticity modulus of the PTC material is improved, the maximum stress and the stress of a breaking point of the PTC material are increased, so that the PTC strength and the stretch resistance performance of the PTC heating material are improved.