TW411349B - Method for controlling color formation during polytetramethylene ether glycol production - Google Patents

Abstract

A process for removing precursors, such as low boiling alkyl glycols (e.g., ethylene glycol and/or 1,2-propylene glycol), to undesirable color forming acetal impurities (e.g., 1,3-dioxolane and 4-methyl-1,3-dioxolane) from technical grade 1,4-butanediol/2-methyl-1,4-butanediol mixtures and the like by distillative topping of the diol mixture prior to ring closing cyclization to corresponding tetrahydrofuran/3-methyl tetrahydrofuran mixture and subsequent polymerization to polytetramethylene glycol ether polymers. Such a process is useful to produce THF and PTMEG having a APHA color index of nearly zero.

Description

Consumption cooperation among employees of the Central Bureau of Standards of the Ministry of Economic Affairs. Du printed A7-B7 V. Description of the invention (1) Invention back f 1. Field of the invention: The present invention relates to the production of polytetramethylene bond diols (pTMEG) and Relevant copolymers previously removed precursors of poorly color-forming impurities. More specifically, but not by way of limitation, the present invention relates to an improved mixture of 1,4-butanediol or 1,4-butanediol and a low-carbon, substituted 14-butanediol A method for the formation of a color-forming acetal precursor, including cyclization of the corresponding argon tetrahydrofuran (THF) and 3-alkyltetrahydrofuran (3-alkylTHF) and subsequent polymerization to produce PTmeG was previously distilled 2. Description of related techniques:-Commonly known and accepted commercial practice of making ptmEG from 1,4-butanediol is to catalytically cyclize it to THF, separate THF and then catalyze polymerization. In addition, it is generally accepted that even purified 14-butane distillate contains small amounts of other two groups, such as methyl, 4-butanediol, and poor and difficult to separate impurities. May cause color control problems in the final polymer and its subsequent use. For example, U.S. Patent No. 5,112,943 describes a method for preparing a high purity polymer or copolymer using THF and, if necessary, alkylene oxide via cationic polymerization, wherein the polymer is treated with hydrogen in the presence of an argon catalyst to Reduce the color index. The same patent states that technical grade THF contains a small amount of impurities at a concentration of 10 to 500 ppm, the nature of which is not yet fully understood and that it causes discoloration and alters the activity in the preparation of polyesters or polyurethanes.

Even before the hydrogenation of the above PTMEG polymer, it was known that THF -4- This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) ---------- ^ ----- -1T ------ ^ I (Please read the notes on the back before filling out this page) Printed by the Staff Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs

41134S A7 '____B7 ____ V. Certain color-forming impurities in the description of the invention (2) can be advantageously hydrogenated before polymerization β For example, in the US Patent No. 4,257,961, mention is made of methacryl' dihydrogen The content of impurities such as furan (2,3- and 2,5 ·), propionaldehyde and butyraldehyde (n- and isomers) that cause color formation in polymer diols made with THF is obtained by catalyzing anhydrous THF with argon. Reduced to clear. Although there is a method for improving the color contained in PTMEG polymers as described above and it is generally acknowledged that the chemical nature of identifying impurities at ppm level is poorly understood, there is a better understanding and control of the color formation of PTMEGt related plutonium from THF polymerization, especially There is a long felt need to produce commercial-scale quantities of polymers with almost zero APHA color index. Summary of the Invention In view of the above problems and long felt needs, the present invention has discovered a method for removing harmful color forming properties from a commercial grade 1,4-butanediol distillate before the ring closure cyclization polymerization reaction. Method for precursor acetal and related impurities. According to the present invention, the improved method for preparing a polytetramethylene ether diacid polymer or copolymer having an improved color includes the following steps: (a) will optionally contain one or more 2-alkyl · 1,4 -Continuous distillation of succinic 1,4-butane fermentation liquid distillate, wherein the distillate is characterized by containing low-carbon burned diols with a concentration range of up to about 1,000 ppm; at the same time, it has a low content at the top of the column and has a low content. A stream of carbodifluoride impurities and recover from below a stream of 1,4-butanediol optionally containing one or more 2-alkyl-M-butanediols but substantially free of their impurities; (b) The topped 1,4-butanezyme stream produced in step (a) is catalyzed to cyclize, thus producing one or more 3-alkyl-substituted tetrahydrofuran, as appropriate. This paper is applicable to China National Standard (CNS) A4 specification (210X297 mm): --- ^ ----_--- k ------, 1T ------ ^ I (Please read the precautions on the back first (Fill in this page again)

41134S A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the Invention (3) Tetrahydrofuran, in which the cyclic product stream is characterized as being substantially free of 1,3 · dioxolane and 4- Impurities such as alkyl-I, 3-dioxolane; and (c) polymerizing tetrahydrofuran prepared in step (b) optionally containing one or more 3-alkyl-substituted tetraargonfurans to produce an improved Color index polytetramethylene fluorene glycol polymer According to a preferred embodiment of the present invention, the starting 1,4-butanediol itself is a diol having a relatively high total diol content (typically 99.9% by weight of diol). Commercially available steamed fillings, which may contain trace amounts of up to about 16% by weight of 2 • methyl-1,4-butanediol, which are derived from 1,4-butanediol derived from the gasification of butyne dienzyme Formaldehyde (can be inherently generated in situ or intentionally added) (see U.S. Patent Nos. 4,590,312 and 4,590,285) "One object of the present invention is to propose an inexpensive and convenient commercial scale method To remove harmful color-forming impurities in polymers derived from THF and THF Before miscellaneous. Another item of the present invention is to propose a method for removing alkanediol from succinic acid by distillation topping and then preparing a cyclocyanine substantially free of the corresponding 1,3-dioxolane acetal. method. The realization of these objects and the existence and realization of other objects can be clearly understood from the complete reading of the description of the present invention and the patent application attached hereto. Description of the preferred embodiment From the perspective of the problem of color control in PTMEG commercial scale manufacturing, we have found that it is commercially available in 1,4-butanediol (even though the 1,4-butanediol itself is a distillate). ) Contains some low-boiling impurities, and these impurities can be removed by topping 1,4-butanediol (ie, fractionation and removal of the upper low-stagnation fraction). More specifically, we have found that some of the 1,4-butane fermentation contained in -6- this paper size applies to the Chinese National Standard (CNS) A4 specification (210 X 2W mm) ^ — (Please read the back (Please fill in this page again)

、 1T Consumption cooperation between employees of the Central Bureau of Standards of the Ministry of Economic Affairs, Du printed A7 B7 V. Description of the invention (4) Low-carbon alkanes such as ethylene glycol and propylene glycol (most specifically, 2-propanediol) and other related low Removal of boiling components, etc., in the presence or absence of other 2-alkyl · 1,4 · butanediol, cyclic ethers produced by the catalytic dehydrogenation / cyclization of arsine, 4 · butanediol (THF and 3-pit-based THFs) are substantially free of certain acetals. In addition, these acetals are virtually absent (more specifically, free of 1,3-dioxolane and 4-alkyl-1,3-dioxolane; more specifically, 4-methyl- 1,3 · dioxolane), we have found that the polymerized PTMEG produced by acid catalysis exhibits an improved color index, including almost zero when used in conjunction with other known color improvement techniques ΑΡΗA color index β The fact that ethylene glycol and 1,2-propionase are contained before the distillation of 1,4-butanediamine to remove the low-boiling fractions, and that 13_dioxolane is not included after the ring-closing ether is formed. And 4-methyl · 1,3-dioxolane and the consistent preparation of PTMEG polymers with improved color index have led to our belief that the low-carbon alkane In fact the males cause harmful color formation before the formation of acetal. Although it is not intended to limit the invention to any single theory or explanation, especially from the standpoint that their impurities are present in very low rolls in the order of parts per 10,000 parts by weight, it is currently recognized In the acidic conditions of the cyclization reaction, it also contains a formaldehyde source and the conversion of ethylene glycol and propylene glycol into condensation reactions contains 7-membered cyclic acetals and 1,3-dioxane formation Chemically linked formazan-cyclization couplings (see JW Hill and WH Carothers, J. Amer. Chem. Soc. Vol. 57, pp 925+, I935 and US Patent No. 2,87〇, 〇97). Similarly, without unduly restricting the present invention, it is considered that 1,4-butanediol under these conditions applies to the Chinese National Standard (CNS) A4 specification (210X 297 mm) I n — ™ II Order — ^ (Please read the notes on the back before filling in this page) Consumer Cooperation of the Central Standards Bureau of the Ministry of Economic Affairs, Du Printing 411349 Α7 Β7 V. Description of the invention (5), which may itself be the source of formaldehyde. It is considered that there is a need for improvement and the industrial grade THF considered in the above-mentioned prior art patent No. 5,112,943 contains a small amount of impurities at a concentration of 10 to 500 ppm. Its chemical nature is not yet known and it may cause discoloration. And the fact that the activity is changed in the preparation of polyester or polyurethane is at least a consistent explanation. As will be exemplified later, intentionally quantitatively add ethylene glycol and 1,2-propanediol to 1,4-butanediol, and with and without adding spiking formazan, and the resulting product is topping. The fact that 1,3 · dioxolane and 4-methyl · 1,3-dioxolamine have been detected to increase temporally in the exudate tends to support and confirm these findings and their significance (ie, Explanation of the proposed mechanism) ^ In addition, the fact that the quantitative addition uses a relatively high concentration further confirms that the method of the present invention can be applied to at least industrial-grade THF, for example, containing substantially 99.9 wt. Distillation or topping of low-boiling diols with or without the concentration of β 1,4-butanediol in the liquid phase (with or without one or more 2-alkyl · ι, 4 · butanediol) Removal and the like can be performed by any distillation method and equipment generally known and used in the art. Preferably, and as described in the examples of the present invention, the topping of 1,4-butane is carried out by a static distillation method, and the overhead distillate contains an undesired low-carbon alkanediol (for example, Ethylene glycol and propylene glycol) and other low boiling ingredients. The purified 1,4-butane distillate is taken out as liquid mash or vapor under the molybdenum distillation tower, as generally known in the art. It should be easy to understand, and there may be various other configurations and equipment for accomplishing the topping step. Therefore, for the purpose of the present invention, it must be regarded as equivalent to the one specifically described in the embodiment of the present invention. 1. Cardiac succinate and alkyl-1,4-butanediol turn into tetrahydrocran and 3-pit-based-8-This paper size is applicable to Chinese National Standard (CNS) Λ4 specification (210 × 2W mm) 111 1 n I ^ II ϋ ~~ Order ^ 1 I Saki \ — (Please read the notes on the back before filling out this page) Printed by the Staff Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 411348 Α7 Β7 V. Description of the invention (6) Separate conversion of mum can be accomplished by any catalytic dehydration / cyclization reaction and the like generally known in the art. Typically, the cyclization reaction includes the use of an acidic ammonium 'such as sulfonic acid, Lewis acid, non-oxidizing mineral acid, acidic amidine ion exchange resin, and the like. For example, the cyclization reaction can be completed by using sulfuric acid as described in U.S. Profit No. 3,726,405 β. The THF and 3-alkylTHF produced by the catalytic cyclization reaction are dehydrated and adjusted by ρΗ 値 and This cyclic ether is subjected to multi-stage distillation for further refining, as described in US Patent No. 4,093,633 and the like. Polymerization of THF with or without one or more 3-alkyl-substituted THFs is accomplished via cationic polymerization. In general, any commercially acceptable acid-catalyzed method, with or without various molecular weight control agents, can be used: including 'for example, but not limited to: fluorosulfonic acid; ions having a -s〇3h group Exchange resins; carboxylic anhydrides with strong acids, for example, acetic anhydride of sulfonium cation precursors; and polymer catalysts containing -S03 fluorene groups; β is preferably polymerization using fluorosulfonic acid or -S〇3 fluorene groups Resins such as Nafion ® are used as catalysts. It is expected that the improved method of reducing discoloration of PTMEG of the present invention can also be advantageously used in combination with various techniques for reducing discoloration known in the art. For example, although the method of the present invention is considered to control color by removing low-boiling precursors that lead to acetal formation, previously known techniques related to catalytic gasification of other color-forming impurities suspect that these other impurities are present. It should also be used. In particular, U.S. Patent No. 4,257,961 describes a method for reducing the concentration of methacryl, diargyrane ', propane and butadiene in THF made from acetylene and formaldehyde. The better one is to distill THF-9- This paper size is applicable to China National Standard (CNS) A4 specification (210X297mm) —: ---------;., ^ -— (Please read the back Note for refilling this page) Ordered by the Central Consumers Bureau of the Ministry of Economic Affairs, printed by the Consumer Cooperative

41134S A7 ____ _B7___ 5. Description of the invention (7) The gasification of the substance is used in conjunction with the method of the present invention, as will be further explained in the embodiment of the present invention. So far, the following examples are proposed to more fully confirm and further explain various individual parts and characteristics of the present invention, while comparative examples and displays are intended to further explain the differences and advantages of the present invention. In this regard, their embodiments are to be regarded as non-limiting and intended to describe the invention and not to unduly limit the invention, especially the basic properties of the method of the invention described in the patent application and use. In presenting these examples, the starting material used in the rod-scale commercial implementation was, in fact, industrial-grade crude 1,4-butanediol, which was originally manufactured by the Reppe method (that is, using acetylene and f Aldehyde reaction), which is then purified and desalted essentially by the method described in US Patent No. 3,852,164, and then stored for several months. The specific concentration levels of impurities mentioned in the examples are determined based on the quantitative measurement of the actual logistics during use, and have not been adjusted to the final PTMEG polymer composition (unless otherwise specifically stated otherwise). Example 1 In order to remove low boiling impurities from the degraded industrial-grade 1,4-butanediol / 2-methyl-1succinic acid mixture, the mixture was placed on a 20-inch plate with a 4 inch diameter Distilled in the Oldershaw Tower. At two different ratios of distillate to feed, the lower hydrocarbon impurities were removed from the top of the column. During the distillation, the 1,4-butanediol / 2-methyl-1,4-butanediol mixture was continuously fed to the 15th plate (upward) at room temperature under a pressure of 50 mmHg The steamed mash was completely coagulated, a part of it was taken out as a distillate, and the rest was refluxed to the top plate as a reflux liquid. Take out continuously from the 12-liter re-cooking pot-part of the bottom liquid to keep -10- This paper size applies the Chinese national standard {CNS) A4 specifications (2 丨 0X297 male chelate) ---- ^- ----- A ------ IT ------ Bite I (Please read the notes on the back before filling in this purchase) Printed by A7 __B7__ Five 'Invention Note (8) holds its fullness and represents the desired topping 1,4-butanediol / 2-methyl-1,4-butanediol product. Two steady-state conditions are obtained and are shown in Table I as BDOT1 and BDOT2. The tower conditions corresponding to individual steady states are listed in the table. Table I Proportion (weight) BDOT1 BDOT2 D / F 0.1165 0.095 L / D 1.7 0.16 V / F 0.32 0.11 where: D = distillate rate (g / min) F = feed rate (g / min) L = to the top plate The reflux rate (g / min) V = L + D total (g / min) is then maintained at 125 in a continuous cyclization unit. (: The top 1,4-butanediol / 2-methyl-1,4-butanediol was used with a sulfuric acid catalyst of about 4.0 weight ° / 0 and 7.0 g of Hastelloy chips. The sample was converted to tetrahydrofuran / 3-methyltetrahydrofuran. The unit contained a 1-liter solid-bottom flask with a 5-plate Ödershaw tower; a water-cooled condenser; and a water-cooled condenser. A graduated molybdenum receiver, which can be arranged in a product collection container or vial through a three-way valve. Pump out the 4-butanediol / 2-methyl-I4 · butanediol from the feed container Into the reaction vessel. A part of the cyclization product is pumped back to the top of the Oldershaw tower as the reflux liquid. The reflux ratio is controlled to about 0.3 by adjusting the reflux pump rate. The entire system is kept under nitrogen. From The top 1,4 · succinimide / 2-methyl obtained from operating BDOT1--11-This paper size applies to the Chinese National Standard (CNS) Λ4 specification (210X297 mm) I: -------- ^ ------, order ------ A 1 (Please read the notes on the back before filling this page) 41134S A7 B7 V. Description of the invention (9) I, 4-butanediol will be given to After 34 hours of cyclization unit, Obtained from the operation of BDOT2 via topping 1,4-butanezyme / 2-methyl-1,4-butanediol over 29 hours. Take the product obtained by cyclization from about 35.62 hours (about 19 liters) , Add a small amount of 50% NaOH so that the pH of the substance becomes 11. Then, the substance is continuously fed into a pair of Oldershaw towers with diameters, and the argon tetrahydrofuran / 3-middle tetrahydrofuran / water azeotrope is taken out from the top of the tower. Water and high-boiling matter are taken out from the bottom of the column. Then the azeotropic distillate is placed in a separating funnel, and 5 g of NaOH / 100 g of azeotrope are added. The NaOH will absorb the water in the product and use NaOH / Aqueous solution (containing about 50% water). The partially dehydrated material was passed through a 2 inch diameter glass tube column filled with 4A molecular sieve to reduce its water content to about 0.03 weight® / 〇 & gt The dehydrated product was then placed in a half-inch-diameter bed reactor, and tritiated with Raleigh nickel 2800 as the catalyst. The reactor was operated at 90 ° C and 130 · 140 psi argon. β stagnation time is 7-10 minutes, depending on the flow rate of the liquid. Printed by the Central Standards Bureau of the Ministry of Economic Affairs—Industrial and Consumer Cooperatives (please read the back first) Note: Please fill in this page again) f 1. After that, the gasification products are continuously fed into a pair of Oldershaw towers with a diameter of 3/1, and most of the THF is removed from the top of the tower and the remaining " The final four-gas smelt product containing about 50 00 / 〇3 · methyltetrahydrofuran was refined from the top of the column in high boilers. A part of the refined tetrahydrofuran / 3-methyltetrahydrofuran was purified with tetrahydrofuran. The argon furan product (characterized by 10 ppm & 1,3-dioxolane and no measurable 4-methyl-1,3-dioxolane) was diluted to about 30 weight β / o of 3- Methyltetramethylene squeak, and fluorinated sulfonic acid, FS03H, catalyst was used to polymerize the solution at 35 ° C. 12- This paper size applies Chinese National Standard (CNS) A4 specification (2l0X25 > 7 mm) ~ Economy 41134S A7 ___B7_ printed by the staff's consumer cooperative of the Ministry of Standards and Technology of the People's Republic of China 5. The invention description (ίο) is 4 hours (about 200 g of THF / 3 · methyl THF vs. 22.9 g of FS03H). After quenching the catalyst with water, the unreacted material was distilled off, the copolymer was washed several times with water, and then lime was added for neutralization. After that, the remaining water was distilled off, and the copolymer was dried under reduced pressure at 120-130 ° C, and then it was filtered. The filtered copolymer had an APHA color measurement of zero. Comparative Example 1 In a manner similar to the previous Example 1, a technical grade 1,4 · butanefluorene / 2-methyl-1,4-butanediol mixture was converted into wet THF / 3-methylTHF, with the difference This is because the starting mixture was not treated with steamed molybdenum before the catalytic cyclization (that is, without removal of low boiling diol impurities). The continuous cyclization unit was maintained at ~ 125 ° C using about 4.0% by weight sulfuric acid catalyst and 7.0 grams of Hastelloy-C dust. The unit consists of a 1-liter tritium flask with a 5-plate Oldershaw column on top, a water-cooled condenser, and a water-cooled graduated distillation receiver, which can be drained through a 3-way valve Into product collection container or vial. The desalted industrial-grade 1,4-butanediol / 2-methyl-1,4-butane fermentation mixture was then pumped from the feed vessel and poured into the reaction vessel. A part of the cyclization product was pumped back to the top of the Oldershaw column as the reflux liquid. The reflux ratio was adjusted to about 0.3 by adjusting the reflux pump speed. The entire system was kept under a nitrogen blanket. The 1,4-butanediol / 2 · methyl · 1,4 · butane fermentation mixture was fed to the cyclization unit for 103 hours. The products produced in the last 27 hours of cyclization contain impurities at a representative level of cyclization products of typical commercial-scale plants (i.e., 1,3-dioxolane and 4-methyl 1,3-dioxo The pentanes are each in the range of 150 to 200 ppm). Take -13- This paper size applies Chinese National Standard (CNS) A4 specification (2) 0X297 mm (Read the precautions on the back before filling out this page) 'Order ^ Printed by the Consumer Standards Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 41134S A7 B7 V. Description of the invention (11) The laboratory-made substance (about 19 liters) was added with a small amount of 50% NaOH to make the pH of the substance to about 11. The material was then continuously fed into a one-to-diameter Oldershaw tower, which caused the THF / 3-f-based THF / water azeotrope to be removed from the top of the tower and the water high-boiling matter was removed from the bottom of the tower. . Then put the azeotropic distillate together with 5 g of NaOH / 100 g of azeotrope in a separatory funnel, where NaOH will absorb the water in the product and remove it as NaOH / aqueous solution (~ 50% water) After that, the partially dehydrated material was passed through a 2 inch diameter glass column filled with 4A molecular sieve to reduce its water content to about 0.03% by weight. Next, the dehydrated product was placed in a half-inch-diameter bed reactor and argonized using nickel 2800 as a catalyst. Operate the reactor at 9 ° C and 130-140 psi radon pressure. The dwell time is 7-10 minutes, depending on the liquid flow rate. The hydrogenation product is then successively fed to a 1-inch diameter Oldershaw tower. , Where most of the THF is removed from the top of the column at a reflux ratio of 3/1 and the final " high boiler " is refined from the top of the column containing about 50% by weight of 3-methyl THF A portion of the refined THF / 3-methyl THF product was diluted with THF to a solution of about 30% by weight of methyl methyl THF in THF, and the solution was polymerized at 35 4C with a fluorosulfonic acid catalyst for 4 hours (200 g THF / 3-methyl THF (23: 1 g FS03H). After the catalyst was quenched with water, the unreacted material was distilled off, the copolymer was washed several times with water, and then lime was added for neutralization. The remaining water was distilled off and The copolymer was dried under reduced pressure of 120-130eC, and then filtered. The measured APHA color of the copolymer after filtration was 9 3. -14- The standard of this paper applies to Chinese national standards (CNS > A4 specifications (210X297 mm &gt); ---------------, 4 ------. ^ 1 ------ 1 1 (Please read the notes on the back before filling this page) A7 411348 B7 V. Description of Invention ( 12) Example 2 In order to further demonstrate the effectiveness of removing impurities from 1,4-butanediol / 2-methyl-1,4-butanediol to reduce the color of the copolymer, an industrial grade 1,4-butanediol was used. The alcohol / 2-methyl-1,4-butanediol mixture is dehydrated and then topped out in two separate steps. The dehydration operation is performed with 4 pairs of Oldershaw towers as follows: 10 plates with feed to the reboiler Internal total condenser tower top pressure 300 mmHg Feed at 300 mmHg preheated to ~ 1 40 ° C Tower top temperature 76 6C Boiler temperature 1 6 8 6C Reflux ratio 0.447 Feed composition (wt%) 8.0% H20 Various low boiling Impurities 0.4% 7.63% of 2-methyl-M-butanediol The rest are 1,4-butanediol distillate: (weight./〇)

1% THF 0.85 ° /. Very low boilers <0.01% 1,4-butanediomethyl-1,4-butanediol The rest is the bottom of the water tower: (wt%) 0.30% low boilers -15- This paper applies Chinese national standards (CNS) Μ specifications (210X297 mm) &quot; ------ Order ------ Blow 1 (Please read the precautions on the back before filling out this page) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 41134S A7 A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (13) 8.22% 2-methyl-1,4-butanediol 1.0% water The remaining 1,4-butanediol will be obtained from The bottom of the above-mentioned dehydration operation is topping out with the following configuration: 20 plates, 4 pairs of Oldershaw towers, the top condenser is fed with 50 mmHg pressure at the 10th plate, and the feed is preheated at 50 ramHg to 10 ° C (partial flash) Pot temperature 1 6 8 aC Feed composition: (wt%) 0.30% low boiler 8.220 / 〇2-methyl-1,4-butanediol 1,0% water remaining 1,4-butanediol column bottom composition: (% by weight) &lt; 0.001 low boiler 8.33% 2-methyl-1,4-butanediol remaining balance is 1,4-butanediol steam composition composition two (Mole) 9.22% low boiler 0.13% 2-methyl-1,4-butanediol 1.0% 1,4- The rest of the butanediol is water. Other results: -16- This paper size applies the Chinese National Standard (CNS) Λ4 specification (210X297 mm) bI ^ -------'------- ^ 1-- ---- t / t Please read the notes on the back before filling out this page) Printed by the Central Bureau of the Ministry of Economic Affairs-Industrial and Consumer Cooperatives printed A7 ____B7 V. Description of the invention (14) BDD yield loss 0.01%

Reflux ratio (L / D) 18.0 Distillate / feed (mole / mole) 0 · 86 Column top temperature 8 5 6C In a continuous loop cyclization unit, maintained at ~ 125 ° C, use about 4.0% by weight sulfuric acid catalyst and 7.0 g of Hastelloy-C crumbs will be dehydrated, and the topped 1,4-butanease / 2-methyl-1,4-butanease will be converted to tetrahydrofuran / 3 methyl Tetrahydrofuran. The unit includes a one-liter two-bottom flask with a 5-plate Oldershaw tower on it, a water-cooled condenser, and a water-cooled graduated steam receiver, which can arrange the product through a 3-way valve. A product collection container Or a small sample vial. The dehydrated and topping 1,4-butanediol / 2-methyl-1,4-butanediol was pumped from the feed container into the reaction pot. A portion of the cyclization product was returned to the top of the Oldershaw tower as an echo liquid. The reflux ratio was controlled to about 0.3 by adjusting the reflux pump speed. The entire system was kept under nitrogen. The dehydrated, topping 1,4-butanediol / 2-methyl-1,4-butanedifluoride was fed into the cyclization unit for about 50 hours. Take the product made during cyclization for 22-47 hours (about 20 liters) and add a small amount of 50% NaOH to bring the pH of the material to about 11. The material was then successively fed to a 1-by-diameter Oldershaw tower, where the THF / 3-methylTHF / water azeotrope was removed from the top of the tower and the water and high-boiling materials were removed from the bottom of the tower . This azeotropic distillate is then placed in a separatory funnel with 5 g of NaOH / 1 00 g of azeotrope, where NaOH will absorb the water from the product and remove it as NaOH / aqueous solution (~ 50% water) . Then, pass the partially dehydrated substance through a branch filled with 4 A molecules-17- This paper size applies Chinese national standard (0 ~ 8) six 4% grid (2 [0/297 mm) (please read first Note on the back, please fill in this page again) Order 41134S A7 ____B7 V. Description of the invention (15) Sieve 2 inch straight glass tube column to reduce its water content to about 0,03 weight 0/00 The dehydrated product was placed in a half-inch diameter bed reactor 'with hydrogenation using Ray's Ni 2800 as a catalyst. The reactor was operated at 90 ° C and 130-140 psi argon pressure. The rest time is 7-10 minutes, depending on the liquid flow rate. After that, the argonized product was continuously fed to a one-pronged Oldershaw tower, and most of the THF was taken out from the top of the tower at a reflux ratio of 3/1, and the remaining The top of the column refined the final THF product containing about 50 * / 03. Methyl THF. Take a portion of this refined THF / 3 -methyl THF (its special respect is to have unmeasurable 1,3-dioxolane and &lt; 5 ppm of 4-methyl-1,3-dioxolane) The product was diluted with THF to about 30% by weight of 3-methylTHF, and the solution was polymerized with a fluorosulfonic acid catalyst at 35 &lt; ^ for 4 hours (200 g of butyl) ^ / 3-fluorenyl 1'1 ^ to 22.9 g of FS03H ). After quenching the catalyst with water, the unreacted material was distilled off, the copolymer was washed several times with water, and then lime was added to neutralize it. The remaining water was then distilled off and the copolymer was dried under reduced pressure at 120-130 ° C, and then filtered. The filtered copolymer has an APY A color measurement of 0. Example 3 Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the precautions on the back before filling this page) Zhong Yuqian Examples, incorporating 1,4-butanediol / 2 in a factory operation -Methyl-M-butanedion is a commercial-scale factory proof of intentional top-out. Before starting the operation, the butadiene topping equipment was repeatedly operated with 1,4-butanediol obtained from normal production. Its degasification / cyclization reactor was flushed more than usual to reduce the amount of impurities contained therein. -18- This paper size is in accordance with Chinese National Standard (CNS) Λ4 specification (210X297 mm) 411349 at ___B7_ V. Description of the invention (16) During the operation, the top 1,4-butanediol / 2 -Methyl-1,4-butanediol recovery-related completed top column fillings containing 2 to 7% by weight of ethylene glycol and propylene glycol, respectively, at the bottom of the completed column (i.e. No diol or other low-level substances were detected in the top 1,4-butanediol / 2-methyl-1,4-butanediol). At the beginning, the cyclized THF / 3 -methyl THF product showed 2 to 3 ppm of 1,3-dioxolane and 4-methyl-1,3-dioxolane, and there were 250 to 300 ppm of 1,3-dioxane. At the later stage of the operation, no dioxolane was detected in the THF / 3-methylTHF product and its dioxane level had been reduced to 150-200 ppm. Similarly, in the early stages of the operation, the bottoms of the high boiling column contained 30-80 ppm of each dioxolane, but at the end of the operation, these levels had been reduced to ppm of 1,3-dioxolane. Ring and <20 ppm of 4 · methyl-1,3-dioxolane. A sample of each high boiling column bottom (ie, THF / 3 -methylTHF) was distilled and contacted with fluoric acid. The medium is polymerized. One polymer sample was measured to have a 29 APHA color index. The samples obtained on the following day were measured to have 15, 4, and 3 APHA. Du printed by the staff of the Central Standards Bureau of the Ministry of Economic Affairs (please read the precautions on the back before filling this page) Collect the refined THF / 3 · methyl THF obtained from the operation and store it in two railway oil vehicles. The first was packed with 51.5 wt% 3-methyl THf, which contained 6 ppm of 1,3-dioxolane and 16 ppm of 4-fyl-1,3-dioxolane. The second vehicle contained 47.4% by weight of 3-methylTHF, containing 12 ppm of I, 3-dioxolane and 32 ppm of 4-methyl-1,3-dioxolane. For comparison, about six months ago, a similar product was prepared in a single operation of the same plant, but the dibutane fermentation stream was not topping to obtain 451% by weight of 3-methyl THF. It contains 585 ppm of 1, 3-Dioxolane and 1.246 ppm of 4-methyl--19 This paper rule is printed in Guanjia County (CNS) A4 Lin (UGXW mm) Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs

41134S A7 ____B7__ 5. Description of the invention (17) 1,3-dioxolane ring. PTMEG copolymers made using this material as a source of 3-fluorenyl THF typically have a 150-200 APHA color index. Example 4 In order to further elucidate the speculative chemical mechanism and determine that the alkanedioxane has a role as a precursor that leads to the formation of dioxolane acetal through a formaldehyde reaction, the following experiments were performed. A mixture containing 50 g of 1,4-butanediol, each 1 g of ethylene glycol, 1,2, propanediamine, 37% formaldehyde, and concentrated sulfuric acid was heated to about 140 eC until the THF began to evaporate. Continue to distill until 40 grams of evaporated molybdenum have been collected. The distillate was analyzed by gas chromatography (quantitative results based on total organic matter only) and temporally showed 0.185%. Of 13-dioxolane '0.507¾ of 4-methyl-1,3-dioxolane, 2.08% of 1,3-dioxane, and the rest are THF (and water). The experiment was then repeated without adding formaldehyde to the mixture. In this case, the obtained distillate was analyzed: 0.001% of 1,3-dioxolane ring, 0.004% of 4-methyl-1,3-dioxolane ring, 0.011% of I , 3. Dioxane, and the rest of THF (and water). So far, the present invention has been described and illustrated with a certain degree of particularity. It must be understood that the following patent applications are not subject to their Limitations, but rather provide a scope of the invention that is commensurate with the wording of each and every element of the scope of the patent and its equivalent. -20- This paper size is in accordance with Chinese National Standard (CNS) Λ4 specification (210X297 male 4 &gt; n. I ---------- (Please read the note ^^ on the back before filling this page) Order

Claims (1)

ABCD 41134B VI. Scope of patent application-&quot; &quot; ----------'-- (Please read the precautions on the back before filling in this i) 1. A method of preparing polysilicon with improved color A method of methylene fluorene dimer polymer or copolymer, comprising the following steps: (a) steaming a butadiene glycol liquid containing-or more 2 -alkyl., 4-butanediol as appropriate The noodles are continuously steamed, and the steamed noodles are characterized by containing low-carbon pit diols with a concentration range of up to about 1,000 ppm; at the same time, the stream containing the undesired low-carbon alkanedizyme impurities is removed at the top of the tower and from below Recover an I, 4-butane fermentation stream that contains one or more 2-octyl-1,4-butanedioxins but does not substantially contain their impurities, as appropriate; (b) apply the process prepared in step (a) The topped, 4-dibutadiene stream is catalyzed to cyclize, thus optionally producing tetrahydrofuran containing one or more 3 -alkyl-substituted tetrahydrofurans, wherein the characteristics of the cyclic product stream are substantially Does not contain impurities such as 1,3-dioxolane and 4-pit-1,3-dioxolane; and (c) contains one or more 3-alkyl groups, as appropriate, produced in step (b) -Substituted for tetrahydrofuran Furan be polymerized thereby generating T alkylene group polytetramethylene glycol polymers having improved blind color index. Μ! 2_ The method according to claim 1 of the patent application, wherein the butadiene liquid distillate contains one or more 2-alkyl · 1,4-butanediols, wherein the alkyl group is selected from the group consisting of Among the groups of ethyl, ethyl, propyl, and isopropyl. Printed by the Consumers' Cooperative of the Central Government Bureau of the Ministry of Economic Affairs 3. According to the method in the scope of patent application No. 2, wherein the 2-alkyl-1,4-butanediol is 2.methyl-1,4-butanediol The impurities of the lower alkane dienzyme are ethylene glycol and 1,2-propanedion, the 3-broken-substituted tetrakisperan is 4-methyltetrahydrofuran and the 4-alkyl-1,3-dioxo The pentyl ring impurity is 4 · fluorenyl · 1,3 · dioxolane. 4 The method according to item 3 of the patent application, which further includes the following steps: 21-This paper size is applicable to National Standards (CNS) A4 specifications (210X297 mm) 411349 it C8 ---. D8 VI. Patent application scope '-: Dehydration of a tetrahydrofuran / 4 · methyltetrahydrofuran mixture to a water content of about 0.03% by weight and hydrogenation of the dehydrated mixture, the polymerization step is performed "** 5. Preparations I, 4 · Dioxin method, with or without co-preparation of 2-fluorenyl-1,4-butanediol, this method is the reaction of acetylene with formaldehyde to make 14 butynyl, hydrazone, and then in formazan as appropriate The 14-butynediol is hydrogenated in the presence, and the improvement includes recovering a 1,4-butanediol liquid distillate containing 2methyl-1,4-butanediol as appropriate, wherein the vaporized molybdenum It is characterized by containing low-carbon burned diol impurities with a roll up to about 1000 ppm, and then applying another steady-state steamed dish to the steamed product, while removing the stream containing bad low-carbon alkane diol impurities from the top of the tower Recovered from below, optionally containing 2-methyl · 1,4 · butanediol 4_ butanediol logistics. 6. The method according to item 5 of the patent application, wherein the recovered product is substantially free of low-carbon alkane dioxin, and optionally contains 2-methyl-L4-butanediol in 1,4-butanediol in It was then used for catalytic cyclization and was thus made substantially free of impurities such as 1,3-dioxolane and 4-alkyl-1,3 · dioxolane, as appropriate. Four bites of air squeak. (Please read the note of the back tooth first and then fill in this card) _ 丨 ％ Μ! Printed by the Employees' Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs-22- This paper size is applicable to China Garden Standard (CNS) Α4 size (210X297) %)