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6132 results about "Phenol formaldehyde resin" patented technology

Phenol formaldehyde resins (PF) or phenolic resins are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. Used as the basis for Bakelite, PFs were the first commercial synthetic resins (plastics). They have been widely used for the production of molded products including billiard balls, laboratory countertops, and as coatings and adhesives. They were at one time the primary material used for the production of circuit boards but have been largely replaced with epoxy resins and fiberglass cloth, as with fire-resistant FR-4 circuit board materials.

Method for preparing C/SiC composite material through low-cost fused silicon impregnation method

The invention relates to a method for preparing a C/SiC composite material through a low-cost fused silicon impregnation method, which comprises the following steps: performing calcining pretreatment on a carbon felt or graphite felt at 400-600 temperature; immersing the pretreated carbon felt or graphite felt in a melamine and boric acid solution, thus coating a boron nitride protective layer; immersing in a carbon/silicon carbide slurry water solution, performing impregnation to ensure that pores of the carbon felt or graphite felt are fully filled with carbon/silicon carbide, placing in a sintering furnace, and performing primary fused silicon impregnation treatment at 1600-1800 DEG C; immersing in liquid phenolic resin, and performing carbonization treatment under the protection of an inert atmosphere at 800-1000 DEG C to ensure that all the resin is carbonized; and finally, performing secondary fused silicon impregnation treatment to ensure that carbon produced by carbonization of the resin totally reacts with silicon to generate silicon carbide, thus obtaining the C/SiC composite material. The obtained C/SiC composite material is high in density, low in air pore and free silicon content, and favorable in material strength, toughness and frictional wear performance, and can be used for manufacturing of brake pads.

Carbonising and/or Activating Carbonaceous Material

A method is provided for carbonizing and activating carbonaceous material, which comprises supplying the material to an externally fired rotary kiln maintained at carbonizing and activating temperatures, the kiln having a downward slope to progress the material as it rotates, the kiln having an atmosphere substantially free of oxygen provided by a counter-current of steam or carbon dioxide, and annular weirs being provided at intervals along the kiln to control progress of the material. There may further be provided an externally fired rotary kiln for carbonizing and activating carbonaceous material having a hollow rotary body that has a downward slope towards a discharge end thereof, and which is provided at intervals along its length with annular weirs for controlling progress of the carbonaceous material. In embodiments, there is also provided a process is for producing discrete solid beads of polymeric material e.g. phenolic resin beads having a mesoporous structure, which may be useful as feedstock for the above mentioned carbonization/activation process or which may have other utility e.g. as ion exchange resins. The process may produce resin beads on an industrial scale without aggregates of resin building up speedily and interrupting production. The process comprises the steps of: (a) combining a stream of a polymerizable liquid precursor e.g. a novolac and hexamine as cross-linking agent dissolved in a first polar organic liquid e.g. ethylene glycol with a stream of a liquid suspension medium which is a second non-polar organic liquid with which the liquid precursor is substantially or completely immiscible e.g. transformer oil containing a drying oil; (b) mixing the combined stream to disperse the polymerizable liquid precursor as droplets in the suspension medium e.g. using an in-line static mixer; (c) allowing the droplets to polymerise in a laminar flow of the suspension medium so as to form discrete solid beads that cannot agglomerate; and (d) recovering the beads from the suspension medium. There is also provided apparatus for forming discrete solid beads of polymeric material, said apparatus comprising: a first line for conveying s stream of a polymerizable liquid precursor; a second line for conveying a stream of a dispersion medium with which the polymerizable liquid precursor is substantially or completely immiscible; an in-line mixer configured to receive a combined flow from the first and second lines and to disperse the polymerizable liquid precursor as droplets in the dispersion medium; a vertical polymerization column configured to receive the dispersion medium with the droplets dispersed therein and to permit the polymerizable liquid precursor polymerize while descending the column in a descending flow of polymerization medium; and a vessel at the base of the column for receiving the descending flow of dispersion medium and collecting polymerized solid beads.

Method of preparing alkali lignin modified phenolic resin

A method for preparing alkali lignin modified phenol-formaldehyde resin comprises the following steps: phenol, a first batch of formaldehyde solution, alkali lignin, metal oxide and dilution water are added into a reactor; a second batch of formaldehyde solution is added into the reactor; and a third batch of formaldehyde solution and a first batch of alkaline solution are added, formaldehyde trapping agent and a second batch of alkaline solution are added, and then material is discharged after cooling. The invention adopts the copolymerization technique to prepare an alkali lignin phenol formaldehyde adhesive, lignin and the phenol are added simultaneously, obtained hydroxymethylated lignin is reacted with hydroxymethyl phenol, a small part of the obtained hydroxymethylated lignin participates in the polycondensation of the hydroxymethyl phenol to form a main chain, and a large part of the obtained hydroxymethylated lignin forms branch chains through graft copolymerization, therefore, the lignin is introduced into a molecular chain and the aim of modifying phenol-formaldehyde resin is achieved. The invention can replace the use of 30-50 percent of the phenol, realizes stable and easy reaction control and easy industrial production; the bonding strength satisfies the requirements of national I-level plates; formaldehyde release reaches E0 level; therefore, the invention provides a new approach to the development of environment-friendly biomass-based wood adhesive and resource utilization of waste materials.

Copper-free ceramic friction material with little falling ash and preparation method thereof

InactiveCN101823856AAvoid secondary pollutionMeet the requirements of environmental protectionBraking membersFriction liningAdhesiveAramid
The invention discloses a copper-free ceramic friction material with little falling ash and a preparation method thereof. The copper-free ceramic friction material with little falling ash is prepared by mixing, shaping and thermally processing the following raw materials in percentage by weight: 5 to 14 percent of adhesive, 20 to 45 percent of reinforcing material, 10 to 40 percent of ceramic material, 10 to 18 percent of lubricant and the balance of filler, wherein nitrile rubber modified phenolic resin and nitrile rubber powder are used as the adhesive; the reinforcing material is one or a mixture of more of aramid fiber, carbon fiber, steel fiber, foam iron powder and aluminum oxide fiber; the ceramic material is one or a combination of more of molybdenum disulfide, magnesium oxide andferrous disulphide; the lubricant is the mixture of graphite and mica; and the filler is the mixture of composite filler, barite, friction powder and aluminum powder. The material has high friction performance, low brake noise and high heat fading resistance, and particularly shows high performance in aspects of wear resistance, long life and great reduction in the falling ash of a wheel hub; therefore, the material can meet both the requirement of a modern automobile braking system on operating conditions and the requirement on economy and environment friendliness when an automobile is used.

Method for preparing graded porous carbon with hollow mesoporous silicon spheres as templates

The invention discloses a method for preparing graded porous carbon with hollow mesoporous silicon spheres as templates. The prepared graded porous carbon can be used as an electrode material for a super capacitor. According to the method, specifically, hollow mesoporous silicon spheres are used as templates, and phenol-formaldehyde resin is used as a carbon source; with a nanometer casting method, an ethanol solution of phenol-formaldehyde resin is impregnated into mesoporous channels of the hollow mesoporous silicon spheres; phenol-formaldehyde resin is processed from primary curing, deep curing, carbonizing and template removing; and graded porous carbon with micropores, mesopores and micropores is prepared. Through the alterations of the hollow mesoporous silicon sphere particle sizes, hollow mesoporous silicon sphere wall thickness and the regulation of the phenol-formaldehyde resin amount, graded porous carbon parameters such as appearance, particle size, and wall thickness can be regulated. With the preparation method, the prices of the raw materials are low, the preparation technology is simple, and the prepared graded porous carbon has relatively high specific surface area and pore capacity. Therefore, the porous carbon can be used as the electrode material for the super capacitor.

Water-based heat transfer printing release coating, and preparation method and application thereof

InactiveCN104403544ASolve the hardnessSolve the shortcomings of poor scratch resistancePolyurea/polyurethane coatingsThermographyWater basedEpoxy
The invention belongs to the technical field of preparation of release coatings and discloses a water-based heat transfer printing release coating, and a preparation method and application thereof. The water-based heat transfer printing release coating comprises the following ingredients by mass percent: 40-60 percent of water-based resin, 8-15 percent of a coalescing agent, 0.3-2 percent of a scratch-resistant anti-wear agent, 0.05-0.2 percent of a foam killer, 0.2-0.6 percent of other additives and the balance of water, wherein the water-based resin is at least one of polyurethane resin, polyacrylic acid resin, polycarbonate, polymide resin, polyethersulfone resin, epoxy resin, thermoplastic polyester resin, a styrene-maleic anhydride copolymer and phenolic resin. According to the invention, application of the water-based formula to preparation of the water-based heat transfer printing release coating is realized, the material prescription is environment-friendly, and the preparation process is safe and environment-friendly. Compared with a conventional solvent product, the water-based heat transfer printing release coating is better in heat resistance, high in glossiness and better in printing ink adhesion, effectively enhances the printing ink protecting function and can be kept colorful in a long term.
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