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45 results about "P-Dihydroxybenzene" patented technology

Preparation method of low-triphenyl phosphate engineering plastic halogen-free flame retardant

The invention belongs to the technical field of applied engineering plastics, and in particular, relates to a preparation method of a low-triphenyl phosphate engineering plastic halogen-free flame retardant. The method comprises the steps: under the action of a Lewis catalyst, carrying out a reaction of phenol with phosphorus oxychloride, reducing the pressure and distilling out excess phosphorusoxychloride, to obtain a mixture intermediate; carrying out a condensation reaction of the mixture intermediate and p-dihydroxybenzene, carrying out a reaction of the mixed intermediate with a properamount of p-dihydroxybenzene firstly, after a part of p-dihydroxybenzene is completely reacted, carrying out high vacuum dehydrochlorination, then adding triethylamine and the remaining p-dihydroxybenzene at relatively low temperature, and carrying out a reaction, wherein increase of the content of triphenyl phosphate is greatly reduced, toxicity to human bodies is reduced, and at the same time, the purity and the yield of the product are improved; and the preparation method has the advantages of simple process operation, short production cycle, economy and environmental protection, can satisfy the requirements of industrial scale production, and is suitable for industrialized popularization and application.
Owner:ZHEJIANG WANSHENG

Preparation method of polyether ether ketone terpolymer

The invention provides a preparation method of polyether ether ketone terpolymer. The polyether ether ketone terpolymer, which is prepared by taking 4,4'-difluorobenzophenone, p-dihydroxybenzene and 4,4'-biphenol as raw materials, taking diphenyl sulfone as a solvent and taking a mixture of sodium bicarbonate and potassium bicarbonate as a salt-forming agent, has high heat stability, high mechanical property and high processability. The p-dihydroxybenzene and the 4,4'-biphenol serve as a phenol monomer mixture, the steric hindrance of the polyether ether ketone polymer is increased and the temperature resistance of the product is improved; in addition, the 4,4'-biphenol is not liable to oxidation compared with the p-dihydroxybenzene, and the stability of the phenol monomer can be improved due to addition of the 4,4'-biphenol.
Owner:YIBIN TIANYUAN GRP CO LTD

Method for producing N-cyanoethylaniline and N,N-dicyanoethylaniline by adopting one-step cleaning process

The invention relates to the field of chemical engineering and in particular relates to a method for producing N-cyanoethylaniline and N,N-dicyanoethylaniline by adopting a one-step cleaning process. The method comprises the following steps: adding aniline, acetic acid, zinc chloride, acrylonitrile, water and a small quantity of p-dihydroxybenzene into a reaction kettle in sequence; slowly heating while starting a re-distillation condenser, and keeping re-distillation for 10 hours after the re-distillation temperature meets the requirement; keeping standing for 1-2 hours, barreling a lowest-layer water phase for analyzing and metering, and feeding an upper-layer organic phase into a middle tank to take part in next reaction; preserving heat of the middle tank to be not less than 60 DEG C, rectifying the product by using a continuous rectifying tower to obtain light components from a first outlet, and returning the light components to a reaction system to obtain N-cyanoethylaniline from a second outlet and obtain N,N-dicyanoethylaniline from a third outlet, wherein the light components are mainly HAC, H2O and acrylonitrile; and incinerating rectified residues to obtain zinc chloride powder which continues to be used as a catalyst. The novel process is simple to control, clean, environment-friendly, low in consumption and safe.
Owner:浙江汇翔新材料科技股份有限公司

Method for preparing phenol and dihydroxybenzene by catalytic hydroxylation of benzene

The invention discloses a method for preparing phenol and dihydroxybenzene by catalytic hydroxylation of benzene. The method comprises that benzene undergoes a one-step hydroxylation reaction in the presence of acetonitrile as a solvent, H2O2 as a hydroxylation reagent and pigment green B as a catalyst to be converted into phenol, o-dihydroxybenzene and p-dihydroxybenzene, wherein a mass ratio of H2O2 to benzene is (3 to 8): 1; a mass ratio of acetonitrile to benzene is (15 to 30): 1; a mass ratio of the catalyst to benzene is (0.05 to 0.1): 1; catalytic hydroxylation time is in a range of 4 to 7 hours; and a catalytic hydroxylation temperature is in a range of 40 to 70 DEG C. The method adopts the pigment green B as a catalyst and provides a novel catalysis system for synthesizing phenol, o-dihydroxybenzene and p-dihydroxybenzene by pigment green B catalysis of benzene. The method overcomes the defects that the traditional technology has a lot of reaction steps, produces serious pollution and has a low atom utilization rate. Catalytic hydroxylation is carried out under mild conditions so that discharge of three wastes is reduced; the catalyst can be separated out easily; and a phenol yield is high. Therefore, the method is an environmentally-friendly green synthesis technology of phenols.
Owner:TIANJIN UNIV

Method for separating and detecting harmful phenols in main stream smoke of cigarettes

The invention provides a method for separating and detecting harmful phenols in main stream smoke of cigarettes to overcome the drawback of the prior art that a high efficiency liquid chromatography can only measure the mixed content of m-cresol and p-cresol when used to detect the harmful phenols in the main stream smoke of the cigarettes by adding a certain amount of beta-cyclodextrin in a flowing phase of the high efficiency liquid chromatography. Thus, while successfully separating and detecting isomers of the m-cresol and the p-cresol, the method avoids influencing the separation and measurement of the content of o-dihydroxybenzene, m-dihydroxybenzene, p-dihydroxybenzene, phenol and o-cresol. The method is expected to be applied to daily detection of harmful phenol substances of cigarette products.
Owner:CHINA TOBACCO GUIZHOU IND +1

Method for preparing soft magnetic manganese-zinc-iron composite material by using manganese-containing waste liquid and zinc mud produced in the production of hydroquinone

The invention discloses a method for preparing a soft magnetic manganese-zinc-iron composite material by using manganese-containing waste liquor and zinc sludge produced during production of p-dihydroxybenzene. The method comprises the following steps: adding the zinc sludge into the manganese-containing waste liquor, leaching under stirring, filtering, adding a flocculating agent into filtrate to remove silicon and aluminum impurities, adding ammonium bicarbonate into purified liquid containing manganese and zinc for co-precipitating, and washing to obtain co-precipitated powder; calcining the co-precipitated powder for decomposing, and washing by using organic acid to obtain a manganese-zinc composite material; and adding iron sesquioxide or a mixture of iron sesquioxide and at least one of manganous-manganic oxide and zinc oxide into the manganese-zinc composite material, and pre-burning to obtain the soft magnetic manganese-zinc-iron composite material. By taking the manganese-containing waste liquor and the zinc sludge produced during production of p-dihydroxybenzene as raw materials, the problem of environmental pollution is solved, high-value utilization of waste is fully realized, and a manufactured magnetic device is free from crystal spots, is non-crispy, and has high shearing resistance as well as fully-qualified physicochemical indexes and electromagnetic performance.
Owner:CHONGQING SHANGJIA ELECTRONIC CO LTD

Method for preparing carrier resin for high-temperature-resistant molding process coloring materials

InactiveCN109575258AAccurate control of heating ratePrecise control of cooling rateAlcoholLiquid state
The invention discloses a method for preparing carrier resin for high-temperature-resistant molding process coloring materials. The method includes steps of 1, uniformly mixing and stirring, by weight, 70-100 parts of dihydric alcohol, 60-100 parts of polyacid and 15-25 parts of diacid anhydride with one another to obtain first mixtures in nitrogen atmosphere, gradually heating the first mixturesuntil the temperatures of the first mixtures reach 195-235 DEG C, carrying out condensation reaction, preserving heat after reaction systems become uniform and transparent, and continuing to carry outreaction; 2, cooling products obtained at the step 1 until the temperatures of the products reach 175-185 DEG C, adding 7-8 parts of p-dihydroxybenzene into the products, uniformly stirring the p-dihydroxybenzene and the products to obtain second mixtures, then cooling the second mixtures until the temperatures of the second mixtures are lower than 45 DEG C, and filtering the second mixtures to obtain the carrier resin. The method for preparing the carrier resin for the high-temperature-resistant molding process coloring materials has the advantages that the dihydric alcohol, the polyacid anddiacid are mixed with one another to obtain the first mixtures in the nitrogen atmosphere, the first mixtures are heated until the temperatures of the first mixtures reach 195-235 DEG C, the condensation reaction is carried out, the heating rates can be accurately controlled, accordingly, products only contain few small molecules and are in excellent liquid states, and the high-temperature resistance of the products can be improved.
Owner:镇江利德尔复合材料有限公司

Mechanochemical synthesis method of 1,4-bis(4-nitrophenoxy)benzene

The invention relates to a mechanochemical synthesis method of 1,4-bis(4-nitrophenoxy)benzene. The mechanochemical synthesis method is a natural synthesis method which includes that p-dihydroxybenzene and p-nitryl benzene halide are synthesized to form the 1,4-bis(4-nitrophenoxy)benzene by catalysis of metal salt and promotion of mechanical force. The mechanochemical synthesis method specifically includes: adding the p-dihydroxybenzene and the p-nitryl benzene halide into a ball-milling tank, adding a catalyst, alkali silica gel and a milling ball to perform mechanical and chemical reactions, after the reaction is over, transferring a reaction mixture by an organic solvent, filtering out undissolved matters, concentrating a filter liquid, and recrystallizing the concentrated filter liquid to obtain the yellow and green crystal product 1,4-bis(4-nitrophenoxy)benzene. The mechanochemical synthesis method of the 1,4-bis(4-nitrophenoxy)benzene has the advantages of simplicity in operation, short reaction time, high atom economy, high product yield, high product purity which is higher than 99% and applicability to industrial use.
Owner:ZHEJIANG UNIV OF TECH
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