CN1204106C - Method for producing 2, 2'-methylene double (4-methyl -6-tertiary butyl phenol) - Google Patents
Method for producing 2, 2'-methylene double (4-methyl -6-tertiary butyl phenol) Download PDFInfo
- Publication number
- CN1204106C CN1204106C CN 02145226 CN02145226A CN1204106C CN 1204106 C CN1204106 C CN 1204106C CN 02145226 CN02145226 CN 02145226 CN 02145226 A CN02145226 A CN 02145226A CN 1204106 C CN1204106 C CN 1204106C
- Authority
- CN
- China
- Prior art keywords
- zeolite
- catalyst
- reaction
- acid
- tertiary butyl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
The present invention relates to a method for manufacturing 2, 2'-diisocyanate (4-methyl-6-tertiary butyl phenol), which mainly solves the defects of higher reaction post treatment and preparation cost, equipment corrosion, easy breakage caused by a resin catalyst in a stirring reaction and no stability in the prior art which uses a liquid acid catalyst. The method uses methylal and 2-tert-butyl-4-cresol as raw materials, and a reaction is carried out in two fixed bed reactors connected in series and loading a solid acid catalyst. The catalyst is macroporous strong acidic cation exchange resin or a zeolite catalyst, wherein the zeolite catalyst contains 60 to 80 wt% of SiO2 /Al2O3, zeolite with a molar ratio of 15 to 100 and 20 to 40 wt% of adhesive, and the zeolite is selected from ZSM-5 zeolite and mordenite or a mixture of the ZSM-5 zeolite and the mordenite. The temperature of the reaction is from 30 DEG C to 150 DEG C. The method realizes the continuation of the production, and has simple post treatment of the reaction. The method has the characteristics of high product yield, good quality and high stability of the catalyst.
Description
Technical field
The present invention relates to a kind of production 2, the method for 2 '-methylene-bis (4-methyl-6-tert butyl phenol).
Background technology
2,2 '-methylene-bis (4-methyl-6-tert butyl phenol), commodity are called antioxidant 2246, and English name is: 2,2 '-Methylenebis (4-methyl-6-tert-butylphenol); Molecular formula is: C
23H
32O
2, be universal powerful bisphenols oxidation inhibitor.Antioxidant 2246 is a kind of good uncontamination oxidation inhibitor, to oxygen, the be full of cracks aging and that daylight causes that heat causes all has good inhibition effect, and it is high to have heat resistanceheat resistant stability, antioxidant effect is good, do not pollute, not painted, no blooming, oil soluble is good, be difficult for volatilization loss, sulfuration and plasticity-to rubber do not have influence, to the latex characteristics of stabilization invariably, be widely used in natural and various synthetic rubber, resin, polyethylene (PE), polypropylene (PP), polyoxymethylene, penton, in the multiple synthetic materials such as urethane, as the substitute products of antioxidant 264, the market of antioxidant 2246 just progressively increases.
The method that early stage bibliographical information is produced antioxidant 2246 adopts traditional " formaldehyde technology ", be to be raw material with formaldehyde and the 2-tertiary butyl-4-cresols, make catalyzer with fluid sulphuric acid, about 100 ℃ of temperature of reaction, under about 5 hours of the reaction times condition, formaldehyde is done bridging agent and is made product by condensation reaction, about product yield 90%, product fusing point 〉=120 ℃, the disadvantage of this technology is that environmental pollution is serious, 1 ton of product of every production will produce the waste water about 5 tons, and is the highest even reach 12 tons of waste water, and the quality product that obtains simultaneously is undesirable.
Serious in order to overcome the environmental pollution that traditional technology exists, poor product quality, the defective that production technique falls behind, the early eighties people have successively proposed a kind of improvement technology that replaces formaldehyde with methylal, claim " methylal technology ", introduced a kind of method of producing two or many sterically hindered phenol as US4319052, US4087469 has introduced a kind of production 2,2 '-methylene-bis (4,6 dialkyl phenols) method, wherein the method that adopts of US4087469 is to be raw material with methylal (or acetal) and 2,4 dialkyl phenols, methylal (acetal) and 2,4 dialkyl phenol mol ratios are 1～10: 1, in the presence of acid catalyst, adopt intermittently stirring reaction mode, in 30～140 ℃ of reactions, obtain a kind of reaction mixture, separate this mixture, the product that obtains expecting, product yield are 70～99%.Methylal technology has solved waste water from the raw material at all and has had problems as can be seen from following two reaction formula, has reduced environmental pollution, has had than much progress than traditional technology.
Formaldehyde technology:
Methylal technology:
An acidic catalyst that document US 4087469 is used comprises sulfuric acid, phosphoric acid and ion exchange resin etc., when making catalyzer with liquid acid, reacted product needs to use alkaline purification earlier, and then distills purification, increased the last handling process and the preparation cost of reaction, and corrodibility is strong; When spent ion exchange resin is made catalyzer,, do not relate to the stability problem of resin catalyst though overcome the defective of liquid acid catalyst, and resin catalyst to be used for stirring reaction broken easily, influence its physical strength and work-ing life.
Summary of the invention
Technical problem to be solved by this invention is to overcome the liquid acid catalyst of using that exists in the above-mentioned document, need carry out post-reaction treatment, increases preparation cost, and equipment is caused corrosion; And resin catalyst is used for stirring reaction fragmentation easily, the defective that does not relate to catalyst stability, a kind of new production 2 is provided, the method for 2 '-methylene-bis (4-methyl-6-tert butyl phenol), this method can serialization production, little to the catalyst breakage degree, and post-reaction treatment is simple, and preparation cost is low, and equipment is not had corrosion, have the product yield height, quality is good, the characteristics that catalyst stability is good.
For solving the problems of the technologies described above, the technical solution used in the present invention is as follows: a kind of production 2, the method of 2 '-methylene-bis (4-methyl-6-tert butyl phenol), with methylal and the 2-tertiary butyl-4-cresols is raw material, make raw material enter the fixed-bed reactor of two series connection, loading solid acid catalyst, 30～150 ℃ of reactions down, the raw material methylal and the 2-tertiary butyl-4-cresols mol ratio is 2～10: 1,50～200 milliliters/hour of feeding rates, reacted crude product obtains 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product through distillation, purification; Described solid acid catalyst is macropore strong acid cation exchange resin or zeolite catalyst, and zeolite catalyst contains 60～80%SiO by weight
2/ Al
2O
3Mol ratio is 15～100 zeolite and 20～40% binding agent silicon-dioxide or aluminum oxide, and zeolite is selected from HZSM-5 zeolite, h-mordenite or their mixture.
In the technique scheme, 40～100 ℃ of temperature of reaction preferable range, the mol ratio preferable range of methylal and the 2-tertiary butyl-4-cresols is 3～5: 1, preferred 50～100 milliliters/hour of feeding rate.
Preparation method of the present invention at first with raw material methylal and the 2-tertiary butyl-4-cresols by 2～10: the mixed of 1 (mol ratio) is mixed with solution, make raw material enter two placed in-line fixed-bed reactor through volume pump, loading solid acid catalyst in the reactor, under the acid catalyst effect, raw material reacts under above-mentioned processing condition produces antioxidant 2246, the temperature of reaction of two reactors improves gradually according to the charging order, the reactive behavior of the catalyzer of adorning can be identical, also can improve gradually according to the charging order, from the effusive reaction mixture of second reactor bottom, after overcooling, distillation, purification obtains the antioxidant 2246 product, promptly 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol), the methylal that distills out recycles.
The solid acid catalyst that the inventive method is used is selected from ion exchange resin or zeolite catalyst, and the resin catalyst of use belongs to the macroporous polystyrene frenulum sulfonic group (SO
3H) storng-acid cation exchange resin, its acidity is equivalent to mineral acids such as sulfuric acid, hydrochloric acid, the resin catalyst mean pore size is greater than 80 dusts, its exchange capacity is 3.0～5.0 milligramequivalent/grams, resin catalyst carries out drying treatment before using, 80～105 ℃ of treatment temps, 1～5 hour treatment time; The zeolite catalyst that uses contains 60～80%SiO by weight
2/ Al
2O
3Mol ratio is 15～100 zeolite and 20～40% binding agents, zeolite is selected from the HZSM-5 zeolite, h-mordenite or their mixture, Preparation of catalysts be with zeolite powder and binding agent silicon-dioxide or aluminum oxide mix pinch after, moulding, dry, roasting, catalyzer after the roasting can directly use, the organic acid soln that also can be 0.05～2.0 mol with firing precursor concentration carries out acid treatment, and organic acid can be a formic acid, acetate or citric acid, treatment temp are 50～100 ℃, time is 1～10 hour, acid and zeolite volume ratio are 1～10: 1, and be dry then, 300～600 ℃ of following roastings 2～10 hours.
The principal feature of the inventive method is the fluid sulphuric acid catalyzer that replaces prior art with solid acid catalyst, the stirring reaction at intermittence that replaces prior art with continuous fixed bed reaction or continuous, use the obvious advantage of solid acid catalyst to be: resultant of reaction is easy to separate with catalyzer, simplify the post-reaction treatment process, reduce preparation cost, equipment there is not corrosion, using the advantage of continuous fixed bed reaction or continuous is the reaction conditions gentleness, realize the production serialization, overcome stirring reaction to the defective that resin catalyst intensity and structure damage, prolonged catalyzer work-ing life.
The inventive method makes spent ion exchange resin or zeolite catalyst, adopt two sections continuous fixed bed reaction or continuous technical process, by temperature of reaction or the catalyst activity control conversion of raw material of controlling every section reactor, reduce by every section catalyst reaction load, prolong catalyzer work-ing life, make catalyzer have satisfactory stability, product 2, the highest yield of 2 '-methylene-bis (4-methyl-6-tert butyl phenol) reaches 98%, product purity is greater than 98%, the fusing point of product rises to 128～130 ℃ from 120 ℃ of formaldehyde technology, thereby increased substantially the antioxygen property of 2246 oxidation inhibitor, the resin catalyst that uses as embodiment 2 was through 400 hours successive reactions, trend does not fall in the 2-tertiary butyl-4-cresols transformation efficiency as follows, and the exchange capacity of resin remains unchanged substantially before and after the reaction, and the HZSM-5 zeolite catalyst that embodiment 4 uses was through 500 hours successive reactions, and trend does not fall in the 2-tertiary butyl-4-cresols transformation efficiency as follows.The inventive method has reaction conditions gentleness, product yield height, quality and reaches advantages such as catalyst stability is good well, especially the feature of environmental protection that solid acid catalyst had and satisfactory stability, comparing with prior art processes and to have obvious improvement, is that prior art processes is incomparable.
The raw material that the inventive method is used:
Methylal, analytical pure, reagent three factories in Shanghai produce, and the density under 25 ℃ is 0.855 gram per centimeter
3
The 2-tertiary butyl-4-cresols, coarse raw materials are taken to Shanghai Taurus chemical industry company limited, and through rectification and purification, content is greater than 99% (weight).
The present invention is further elaborated below by embodiment.
Embodiment
[embodiment 1]
Resin catalyst A:
With vinylbenzene-divinylbenzene interpolymer is the macropore strong acid (SOH of skeleton
3) Zeo-karb, exchange capacity 4.3 milligramequivalent/grams, resin mean pore size 205 dusts.
Respectively load 40 milliliters of catalyst A in two series connection fixed-bed reactor, drying is 3 hours under 90 ℃; Methylal and the 2-tertiary butyl-4-cresols compound (aldehyde/phenol mol ratio=3: 1) are passed through volume pump, pass through first, second reactor successively with 80 milliliters of/hour speed, 45 ℃ of the first reactor reaction temperature, 80 ℃ of the second reactor reaction temperature, reaction continuous operation 200 hours, collect the effusive reaction mixture of second reactor bottom, distillation removes and desolvates, purify then and obtain 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product, the solvent cycle Returning reactor that distills out uses.In the reaction process, from the effusive reaction mixture of second reactor bottom, take a sample, analyze with gas chromatograph, reaction result represents with the 2-tertiary butyl-4-cresols transformation efficiency and product yield, and when successive reaction after 12 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 95%, after the successive reaction 200 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 96%, measures the exchange capacity of 200 hours front and back of resin catalyst A reaction, and trend does not fall in its exchange capacity as follows.
Product average yield 94%, 128～129 ℃ of product fusing points, product purity 98%.
[embodiment 2]
Resin catalyst B:
With vinylbenzene-divinylbenzene interpolymer is the macropore strong acid (SOH of skeleton
3) Zeo-karb, exchange capacity is 4.8 milligramequivalent/grams, resin mean pore size 350 dusts, and resin is handled in vacuum drier, 105 ℃ of treatment temps, 2 hours treatment times.
In two series connection fixed-bed reactor, respectively load 40 milliliters of catalyst B, methylal and the 2-tertiary butyl-4-cresols compound (aldehyde/phenol mol ratio=4: 1) are passed through volume pump, pass through first successively with 60 milliliters of/hour speed, second reactor, 40 ℃ of the first reactor reaction temperature, 70 ℃ of the second reactor reaction temperature, reaction continuous operation 400 hours, collect the effusive reaction mixture of second reactor bottom, distillation removes and desolvates, purify then and obtain 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product, the solvent cycle Returning reactor that distills out continue to use.In the reaction process, from the effusive reaction mixture of second reactor bottom, take a sample, analyze with gas chromatograph, reaction result represents that with the 2-tertiary butyl-4-cresols transformation efficiency and product yield successive reaction is after 12 hours, and the 2-tertiary butyl-4-cresols transformation efficiency is 99%, after the successive reaction 400 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 100%, measures the exchange capacity of 400 hours front and back of catalyst reaction, and trend does not fall in its exchange capacity as follows.
Product average yield 98%, 129～130 ℃ of product fusing points, product purity 98%.
[embodiment 3]
AmberlystXN-1005 strongly-acid (SOH
3) large hole cation exchanger resin, exchange capacity of resin 3.5 milligramequivalent/grams, mean pore size 80 dusts, resin is handled in vacuum drier, 100 ℃ of treatment temps, 2 hours treatment times.
In two series connection fixed-bed reactor, first reactor loads AmberlystXN-1005 strongly-acid (SOH
3) 40 milliliters of large hole cation exchanger resins, 40 milliliters of the second reactor loading catalyst B, methylal and the 2-tertiary butyl-4-cresols compound (aldehyde/phenol mol ratio=3: 1) are passed through volume pump, pass through first successively with 50 milliliters of/hour speed, second reactor, 55 ℃ of the first reactor reaction temperature, 80 ℃ of the second reactor reaction temperature, reaction continuous operation 200 hours, collect the effusive reaction mixture of second reactor bottom, distillation removes and desolvates, purify then and obtain 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product, the solvent cycle Returning reactor that distills out continue to use.From the effusive reaction mixture of second reactor bottom, take a sample, analyze its content with gas chromatograph, reaction result is represented with the 2-tertiary butyl-4-cresols transformation efficiency and product yield, after the successive reaction 12 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 100%, and successive reaction is after 400 hours, and the 2-tertiary butyl-4-cresols transformation efficiency is 99%, measure the exchange capacity of 200 hours front and back of catalyst reaction, trend does not fall in its exchange capacity as follows.
Product average yield 98%, 129～130 ℃ of product fusing points, product purity 98%.
[embodiment 4]
Catalyzer D:
SiO
2/ Al
2O
3Mol ratio is 45 HZSM-5 zeolite, 80 grams and mixed the pinching of binding agent aluminum oxide 20 grams, extrusion, and drying is carried out acid treatment with the formic acid of 1.0 mol, acid and zeolite volume ratio are 4: 1,80 ℃ of treatment temps, 5 hours treatment times, dry then, at 350 ℃ of following roastings 4 hours, naturally cooling.
In two series connection fixed-bed reactor, respectively load 40 milliliters of catalyzer D, filler is housed up and down, methylal and the 2-tertiary butyl-4-cresols compound (aldehyde/phenol mol ratio=3: 1) are passed through volume pump, pass through first successively with 70 milliliters of/hour speed, second reactor, 50 ℃ of the first reactor reaction temperature, 90 ℃ of the second reactor reaction temperature, reaction continuous operation 500 hours, collect the effusive reaction mixture of second reactor bottom, distillation removes and desolvates, purify then and obtain 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product, the solvent cycle Returning reactor that distills out continue to use.From the effusive reaction mixture of second reactor bottom, take a sample, analyze with gas chromatograph, reaction result is represented with the 2-tertiary butyl-4-cresols transformation efficiency and product yield, after the successive reaction 24 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 94%, after the successive reaction 500 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 93%.
Product average yield 92%, 129～130 ℃ of product fusing points, product purity 98%.
[embodiment 5]
Catalyzer E:
SiO
2/ Al
2O
3Mol ratio is 20 h-mordenite 80 grams and mixed the pinching of binding agent aluminum oxide 20 grams, extrusion, and drying is in 300 ℃ of roastings 2 hours, naturally cooling.
In two series connection fixed-bed reactor, respectively load 40 milliliters of catalyzer E, filler is housed up and down, methylal and the 2-tertiary butyl-4-cresols compound (aldehyde/phenol mol ratio=5: 1) are passed through volume pump, pass through first successively with 100 milliliters of/hour speed, second reactor, 60 ℃ of the first reactor reaction temperature, 100 ℃ of the second reactor reaction temperature, reaction continuous operation 300 hours, collect the effusive reaction mixture of second reactor bottom, distillation removes and desolvates, purify then and obtain 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product, the solvent cycle Returning reactor that distills out continue to use.From the effusive reaction mixture of second reactor bottom, take a sample, analyze with gas chromatograph, reaction result is represented with the 2-tertiary butyl-4-cresols transformation efficiency and product yield, after the successive reaction 24 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 85%, after the successive reaction 300 hours, the 2-tertiary butyl-4-cresols transformation efficiency is 84%.
Product yield 83%, 128～130 ℃ of product fusing points, product purity 98%.
Claims (7)
1, a kind of production 2, the method of 2 '-methylene-bis (4-methyl-6-tert butyl phenol), with methylal and the 2-tertiary butyl-4-cresols is raw material, make raw material enter the fixed-bed reactor of two series connection, loading solid acid catalyst, 30～150 ℃ of reactions down, the raw material methylal and the 2-tertiary butyl-4-cresols mol ratio is 2～10: 1,50～200 milliliters/hour of feeding rates, reacted crude product obtains 2,2 '-methylene-bis (4-methyl-6-tert butyl phenol) product through distillation, purification; Described solid acid catalyst is macropore strong acid cation exchange resin or zeolite catalyst, and zeolite catalyst contains 60～80%SiO by weight
2/ Al
2O
3Mol ratio is 15～100 zeolite and 20～40% binding agent silicon-dioxide or aluminum oxide, and zeolite is selected from HZSM-5 zeolite, h-mordenite or their mixture.
2, method according to claim 1 is characterized in that temperature of reaction is 40～100 ℃.
3, method according to claim 1, the mol ratio that it is characterized in that methylal and the 2-tertiary butyl-4-cresols is 3～5: 1,50～100 milliliters/hour of feeding rates.
4, method according to claim 1 is characterized in that the macropore strong acid cation exchange resin is that macroporous polystyrene is a sulfonic acid cation exchange resin, and its exchange capacity is 3.0～5.0 milligramequivalent/grams.
5, method according to claim 1, it is characterized in that zeolite catalyst concentration is that the organic acid soln of 0.05～2.0 mol carries out acid treatment under 50～100 ℃, time is 1～10 hour, and acid and zeolite volume ratio are 1～10: 1, dry then, roasting.
6, method according to claim 5 is characterized in that organic acid can be formic acid, acetate or citric acid.
7, method according to claim 5 is characterized in that roasting condition is 300～600 ℃ of maturing temperatures, roasting time 2～10 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02145226 CN1204106C (en) | 2002-11-13 | 2002-11-13 | Method for producing 2, 2'-methylene double (4-methyl -6-tertiary butyl phenol) |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02145226 CN1204106C (en) | 2002-11-13 | 2002-11-13 | Method for producing 2, 2'-methylene double (4-methyl -6-tertiary butyl phenol) |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1500768A CN1500768A (en) | 2004-06-02 |
| CN1204106C true CN1204106C (en) | 2005-06-01 |
Family
ID=34232321
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02145226 Expired - Fee Related CN1204106C (en) | 2002-11-13 | 2002-11-13 | Method for producing 2, 2'-methylene double (4-methyl -6-tertiary butyl phenol) |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1204106C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102718634A (en) * | 2012-04-23 | 2012-10-10 | 利安隆（天津）化工有限公司 | Alkylene bialkylphenol compound and preparation method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102807474A (en) * | 2011-06-02 | 2012-12-05 | 中国石油化工股份有限公司 | Preparation methods of substituted diaryl phenol, organophosphorus ester and organic phosphate |
| CN105152866B (en) * | 2015-10-10 | 2017-03-22 | 盐城通海生物科技有限公司 | Method for preparing bisphenol F by adopting polyoxymethylene dimethyl ethers as raw material |
-
2002
- 2002-11-13 CN CN 02145226 patent/CN1204106C/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102718634A (en) * | 2012-04-23 | 2012-10-10 | 利安隆（天津）化工有限公司 | Alkylene bialkylphenol compound and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1500768A (en) | 2004-06-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1326826C (en) | Continuous method for preparing ethyl lactate | |
| CN101863742A (en) | Separation method of m-cresol and p-cresol mixture | |
| CN1204106C (en) | Method for producing 2, 2'-methylene double (4-methyl -6-tertiary butyl phenol) | |
| CN1101265C (en) | Solid acid catalyst containing heteropoly acid and its preparing process | |
| CN1194951C (en) | Prepn process of 2,2'-methylene bis (4-Methyl-6-tert-butyl phenol) | |
| CN1177791C (en) | Process and the manufacture of alpha, alpha-branched carboxylic acids | |
| CN1066071C (en) | Preparation of modified macro-porous zeolite catalyst and synthetic isopropyl aromatic hydrocarbon | |
| CN1810366A (en) | Catalyst for dehydrogenating alkyl arene | |
| CN1935763A (en) | Method for preparing 2,4-di-tert.-butyl phenol alkylating solution | |
| CN102285883B (en) | Method for synthesizing tributyl citrate (TBC) by adopting composite ionic liquid catalyst | |
| CN111517962B (en) | Preparation method of amine anti-aging agent | |
| CN1289450C (en) | 2-tertiary-butyl-4-methyl phenol preparation method | |
| CN1052968C (en) | Akylation of benzene and ethylbenzene manufactured from ethylene | |
| CN1268422C (en) | Preparation of loaded molybdenum oxide catalyst for synthesis of phenyloxalate by ester interchange process | |
| CN113956218A (en) | Synthesis process of 2-acetylfuran | |
| CN112759523A (en) | Styryl diphenylamine antioxidant and preparation method thereof | |
| CN101857533B (en) | Process for producing methylal by composite solid-acid catalyst | |
| CN1208130C (en) | Prepn of solid phosphoric acid catalyst for oligomerization of low-carbon olefine | |
| CN1120750C (en) | Catalyst for synthesizing methyl isobutyl ketone and preparation process thereof | |
| CN1660497A (en) | Application of cesium phosphotungstic acid as catalyst for synthesizing acetyl thiophene | |
| CN1164558C (en) | Method for preparing methyl phenyl oxalate and phenostal | |
| CN1226095C (en) | Solid phosphoric acid catalyst and its prepn process | |
| CN1079284C (en) | Catalyst for toluene disproportionation and alkyl transfer | |
| CN112209791B (en) | Method for producing propylene by tert-butyl alcohol conversion | |
| CN102285882A (en) | Method for synthesizing acetyl tributyl citrate (ATBC) by adopting composite ionic liquid catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20050601 Termination date: 20111113 |