67results about How to "Low in free phenols" patented technology

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.

A dual catalyst system thermoplastic phenolic resin preparation method comprises the steps of proportioning, refluxing and reacting, and drying; the raw materials comprises phenol or m-cresol and aldehydes compound, water, organic acid or inorganic acid and bivalent acetate in a molar ratio of 1:0.5-0.9:0-3.0:0.001-0.040:0.001-0.020; wherein, acetate is used as first catalyst and organic acid or inorganic acid is used as second catalyst in reaction process. The invention adopts phenolic aldehyde addition-condensation reaction in dual catalyst system to prepare the thermoplastic phenolic resin; the method has the advantage of rapid polymerization rate, high yield and low content of free phenols; the thermoplastic phenolic resin can be applied for preparing the coated sand and the prepared coated sand has higher hot tensile strength and tensile strength at room temperature.

The invention discloses a fast-curing type high-temperature resistant binder. The binder is molybdenum modified high o-phenolic resin, and the binder has a structure shown in the specification). The invention further discloses a pre-coated sand in which the molybdenum modified high o-phenolic resin is used as binder; with specially selected dehydrating agent, curing agent and lubricating agent, with optimized dosage, without adding functional auxiliaries like fire-resistant particles and accelerant, the curing speed of the pre-coated sand can be improved significantly, furthermore, the high-strength high-temperature bending strength of the fast-curing type high-temperature resistant pre-coated sand is equal to or greater than 6.0MPa, the normal-temperature tensile strength is 3.0MPa, the heat bending strength is equal to or greater than 3.0Mpa, the low tolerance is equal to or less than 18mL/g, and the radiating property is improved significantly. When the preparation method disclosed by the invention is utilized, the effect is more significant, i.e., the novel pre-coated sand with completely improved combination property is obtained by the improvement of the pre-coated sand raw materials and the method.

The invention discloses a production method of a solid-thermosetting phenolic resin. The production method is characterized by comprising the following steps: mixing and evenly stirring phenol, a base catalyst and aldehyde which are respectively weighed, and heating for the reaction; after the reaction is finished, adding an acidic neutralizer for neutralization, and then adding a non-proton organic solvent; standing for layering the material into a lower-layer water phase, a middle-layer resin phase and an upper-layer solvent phase, separating out the lower-layer water phase and the upper-layer solvent phase, and retaining the middle resin phase; adding an alcohol or ketone organic solvent in the middle-layer resin phase; turning on a film evaporator, transporting the dissolved material to the film evaporator for vacuum dehydration; directly cooling and granulating the qualified resin and packaging; and recovering the solvents for repeated use. By the production method, the softening point of the resin is improved, evaporation efficiency is improved, energy consumption is reduced, and process time is shortened.

The invention relates to the field of brake pad, and particularly relates to an automobile ceramic brake pad and a manufacturing technology thereof. The automobile ceramic brake pad is made from the following raw materials in parts by weight: 6-10 parts of phenolic resin, 12-18 parts of ceramic fiber, 8-12 parts of mineral fiber, 4-8 parts of zinc sulfide, 6-10 parts of nitrile-butadiene rubber phenol, 7-12 parts of artificial graphite, 4-6 parts of potassium titanate fiber, 6-12 parts of steel cotton fiber, 5-8 parts of red copper powder and 6-9 parts of barite. The invention provides an automobile ceramic brake pad and a manufacturing technology thereof, wherein the automobile ceramic brake pad is reasonable in component proportioning, simple in preparation technology and good in high-temperature stability, and has stable friction coefficient, long service life and high safety.

The invention discloses a liquefaction method of lignin for preparing a thermoplastic phenolic resin. The liquefaction method is as follows: mixing phenol, a heteropoly acid catalyst and enzymatic hydrolysis lignin, heating to 90-160 DEG C, and liquefying for 1-3 h to obtain a liquefied product. The invention provides an efficient method for preparing a phenolic compound used for substituting phenol by using enzymolysis lignin in abundant resource, and the method uses the a green heteropoly acid catalyst, which has no pollution to the environment. The enzymolysis lignin liquefaction product obtained by the invention can be used in the preparation of a lignin base thermoplastic phenolic resin.

The invention discloses a preparation method of a phenol-urea-formaldehyde resin adhesive for E0-grade outdoor plywood. The preparation method comprises the following steps: step 1, mixing phenol, a formaldehyde solution and urea, adding a catalyst, and rising the temperature for reaction; step 2, adding the formaldehyde solution and urea which can also be added in the step 3 again, adding an alkali metal hydroxide solution for reaction; step 3, continuing to add the formaldehyde solution and the alkali metal hydroxide solution, if the urea is not added in the former step, adding the urea forreaction at the moment; and step 4, adding the urea and the alkali metal hydroxide solution for reaction until the viscosity is 1.5-2.0 seconds measured by a gardner-holdt tube reverse bubble measurement method, and then discharging. The adhesive-making process is mild in reaction and is easy to control, repeatability is good, and the storage life of the adhesive is more than 30 days. The strength of the plywood made of the adhesive meets the E0-grade requirement of I type plywood.

The invention relates to a preparation method of a bio oil-phenol-methanal copolycondensation resin wood adhesive, belonging to the technical field of fine chemistry and high polymer materials, which comprises the following steps of filtering and refining bio oil to prepare the refined bio oil; adding sulfur and sodium hydroxide solution to the refined bio oil; stirring, heating and reacting to prepare the modified bio oil; and adding phenol and a catalyst to the modified bio oil to prepare the adhesive after reacting. In the method of the invention, the bio oil is taken as a substrate to synthesize the adhesive for wood, and the content of the bio oil is 50 to 60% of the total content of the adhesive. The prepared adhesive has the advantages of high mechanical strength, good waterproof performance and aging resistance, and can be used for preparing the products in high accessories of outdoor stage plywood, particle boards, fiberboards, layer base materials and the like. Moreover, thepreparation technology for pyrolyzing the bio oil wood adhesive is simple and fast, and the resins have the advantages of strong adhesion performance and long storage life.

A polyurethane grouting material for repairing roadbed-bottom culvert defects comprises the following raw materials in parts by weight: 60-80 parts of a polyurethane prepolymer, 15-25 parts of modified phenolic resin, 1-10 parts of organic montmorillonite, 5-15 parts of a fire retardant, 2-3 parts of an antistatic agent, 5-30 parts of a plasticizer, 2-10 parts of a foam stabilizer, 0.05-1 part of a catalyst, and 10-35 parts of a solvent. The polyurethane grouting material for repairing roadbed-bottom culvert defects possesses good curing real-time efficiency and relatively high dimension stability, and also is excellent in mechanical properties and strong in engineering endurance.

The invention discloses phenol-terminated polysiloxane, a preparation method thereof, and a polysiloxane-polycarbonate copolymer. The method includes the following steps: a) catalyzing a reaction of tetramethyldisiloxane and an allyl-containing phenolic compound by using a transition metal catalyst A to prepare phenol-modified hydrogen-containing silane having a phenol group at one end and a silicon-hydrogen bond at one end; b) performing separation by using reduced-pressure rectification to obtain phenol-modified hydrogen-containing silane with purity of >=99%; and c) catalyzing B by using atransition metal catalyst, performing a hydrosilylation reaction on the pure phenol-modified hydrogen-containing silane and polysiloxane with a vinyl end group to obtain the polysiloxane containing aphenol group at the end group. The content of the free allyl-containing phenol compound in the phenol-terminated polysiloxane is 100 ppm or less, the phenol group capping rate is 98% or more, and theresidual metal platinum content is <= 5 ppm. The phenol-terminated polysiloxane is used for preparing the modified polycarbonate, and the obtained polysiloxane-polycarbonate copolymer has a high polysiloxane content, and excellent heat resistance and yellowing resistance.

The invention provides a preparation method of an anti-damping resin grinding wheel. The preparation method of the anti-damping resin grinding wheel comprises 0.5-1.0 mass part of silane coupling agent, 8-12 mass parts of phenolic resin liquid, 50-80 mass parts of 46# plated white corundum, 20-40 mass parts of 54# plated white corundum, 0.5-1.0 mass part of carbon black, 8-12 mass parts of potassium fluoroaluminate, 3-5 mass parts of calcium sulfate whiskers, and 18-23 mass parts of modified phenolic resin powder. Plated white corundum abrasives are adopted; high-temperature coating layers are arranged on the surfaces of the abrasives; the coating layers facilitate improvement of the resin and abrasive interface bonding strength; silane coupling agent molecules contain reaction radicals chemically bonded with inorganic matter materials, and reaction radicals chemically bonded with organic matter materials; inorganic and organic interfaces are bonded to promote the interface fusion to improve the performances; secondly, the modified phenolic resins adopted in the method contain no radicals easy to oxidize in molecular structures compared with general phenolic resins; and the free phenol content in the method is low, so that the performance degradation of hardened resins can be effectively relieved.

The invention discloses a production method for electronic-grade phenolic resin. The production method includes the steps as follows: suctioning 10%-20% total amount of formaldehyde solution into a reaction kettle with a vacuum method, adding catalyst, stirring for 4-6 minutes, adding phenol, starting increasing temperature after charging materials, starting timing when the temperature achieves 70-100 DEG C, continuously dropping 65%-75% total amount of the formaldehyde solution within 1-2 hours, conducting temperature-insulation reaction for 1-10 hours after dropping is finished, then continuously and totally dropping the residual formaldehyde solution within 1-2 hours, and finishing reaction after conducting temperature-insulation reaction for 1-2 hours after dropping is finished. By adding formaldehyde solution in batches to react and by washing, vacuum dewatering, distillation, second vacuum dewatering and final refining, the electronic-grade phenolic resin with high purity can be prepared. The phenolic resin produced by the method is low in impurity content, free phenol content and volatile matter content, has good electrical property and can serve as a curing agent for 'epoxy moulding compounds for encapsulating semiconductor devices and integrated circuits'.

The invention relates to a lignin modified phenolic resin and a preparing method thereof, and belongs to the technical field of phenolic resin. The lignin modified phenolic resin is prepared from, by weight, 50-70 parts of lignin, 100-150 parts of phenol, 2-25 parts of an acidic hemicellulose liquid, 50-100 parts of alkaline hemicellulose liquid, 10-50 parts of soft water, 50-70 parts of phytate phosphorus resin, 1-15 parts of zeolite solid acid, 40-190 parts of formaldehyde, 2-20 parts of gel-type ion exchange resin and 1-15 parts of a nanometer composite catalyst. The preparing method includes the steps that the lignin, the phenol, the hemicellulose liquid, the soft water, the phytate phosphorus resin and the zeolite solid acid are added into a reaction kettle and reacted, then the formaldehyde and the nanometer composite catalyst are added, the mixture is washed, dried and smashed, then the gel-type ion exchange resin is added, and the lignin modified phenolic resin is obtained. The lignin modified phenolic resin is good in stability and low in production cost, and has the excellent size stability, forming processing performance and fire resistance.

The invention relates to the technical field of polymer synthesis of phenolic resin, in particular to a refinement process of linear phenolic resin. The process comprises the steps as follows: (1) putting phenol in a reactor, adding oxalic acid, heating the reactor to 80-100 DEG C, and dropwise adding formalin to the reactor; (2) after dropwise adding the formalin, keeping the temperature, and adding oxalic acid until the pH of the mixed solution in the reactor is 4-6; (3) adding a solvent to the reactor continuously; (4) transferring all materials in the reactor into an extraction kettle, adding water to the extraction kettle for extraction, and separating a water phase; (5) repeating washing operation in step (4) until the pH value of the materials is 6-7 to obtain a crude phenolic resinsolution; (6) transferring the crude phenolic resin solution into a dehydration kettle, and removing residual water under negative pressure; (7) coarsely removing the solvent and small-molecular impurities out of the phenolic resin by a multistage falling-film evaporator, and refining the phenolic resin by a multistage wiped-film evaporator group; (8) granulating the phenolic resin by a drum granulator to obtain a high-purity linear phenolic resin product.

The invention provides a modified phenolic resin adhesive and a preparation method thereof. Tea polyphenol is used for replacing part of phenol; and through combination of the effects of two modifyingagents, the obtained phenolic resin adhesive is high in viscosity, so that quick impregnation of bamboos can be realized, high gluing strength is achieved, firm bonding between bamboo boards and woodboards can be realized, the glue sucking quantity is increased without prolonging the impregnation time, and reduction of the energy consumption is facilitated. Results of the embodiment show that when the modified phenolic resin adhesive is adopted to prepare bamboo-wood composite boards, the water content of the bamboos is only controlled within the range from 25% to 45% without enabling the bamboo water content to be below 6%, so that the composite boards meeting corresponding performance requirements can be obtained. The invention further provides a preparation method of the bamboo-wood composite boards; and the modified phenolic resin adhesive is used as impregnation liquid, and a centrifugal impregnation mode is adopted to dehydrate the bamboos during impregnating, so that impregnation can be realized in a high-moisture state, and the bamboo drying energy consumption is saved.

The invention relates to a halide-containing brake material and a preparation method and application thereof, and belongs to the technical field of brake materials. The preparation method comprises the following steps: adding aromatic alcohol phenolic resin, butadiene rubber, feldspar powder, argil, kaolin, calcined petroleum coke powder and halide into a mixer according to a proportion, mixing and stirring for 20-25min, then adding carbon fibers, potassium titanate whiskers and magnesium borate whiskers according to a proportion, and mixing and stirring for 12-18min until the mixture is uniform to obtain the halide-containing brake material; and placing a steel backing and the brake material into a mold for compression molding, placing the mold into an oven for heating and curing after demolding, and finally machining to obtain an automobile brake pad or a rail transit vehicle brake pad. The friction material of the automobile brake pad and the rail transit vehicle brake pad is particularly suitable for a brake disc with a dual material being aluminum alloy, the porosity of a microporous material is large, the hardness is low, and damage to the brake disc is reduced. The microporous material and the aluminum alloy brake disc are high in heat dissipation speed, the working temperature of a friction pair can be reduced, and the friction pair can bear larger load.

The invention relates to a phenol-polyaldehyde prepolymer modified environment-friendly phenolic resin and a preparation method thereof. The phenolic resin in the method is prepared from phenol, formaldehyde and a phenol-polyaldehyde prepolymer through catalytic synthesis. The preparation method comprises the following steps: synthesizing the phenol-polyaldehyde prepolymer from a polyaldehyde monomer and phenol at a certain temperature in the presence of a catalyst; and introducing the phenol-polyaldehyde prepolymer into a phenolic resin system. The introduction of the phenol-polyaldehyde prepolymer increases the aldehyde equivalent in the system, and can effectively decrease the free phenol content in the resin; and the replacement of part of the formaldehyde with the polyaldehyde can effectively decrease the free formaldehyde content in the resin. Besides, the long-chain structure of the phenol-polyaldehyde prepolymer can enhance the flexibility of the phenolic resin and reduce the internal stress in the curing process, so that a pressed sheet has favorable adhesion strength and can meet the requirements for Class I waterproof plywood. The phenolic resin prepared by the invention has the advantages of low free phenol/free aldehyde content, simple process and the like, and is applicable to the field of production of functional environment-friendly artificial boards.