JPS61123630A - Production of polyalkylene ether polyol - Google Patents

Abstract

PURPOSE:To obtain the titled polyol having terminal hydroxyl group and low corrosiveness, economically in one step, in a manner to enable the recycling of heteropolyacid, by the dehydrative polycondensation of a polyhydric alcohol in the presence of a heteropolyacid. CONSTITUTION:The objective polyol can be produced by the dehydrative polycondensation of an alcohol having >=2 hydroxyl groups in one molecule, in the presence of a heteropolyacid and/or its salt coordinated with or containing <=15mol of water per 1mol of the acid. The case that the alcohol is 1,4- butanediol and the catalyst is free heteropolyacid is excluded from the present process.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention involves the dehydration and condensation of alcohols having two or more hydroxyl groups in the molecule (hereinafter referred to as polyhydric alcohols) to produce polyalkylene ether polyols. The present invention relates to a method for manufacturing.

(Prior art) Polyalkylene ether polyols such as polyoxytetramethylene glycol (hereinafter abbreviated as PTMO) and polyoxine hequinamethylene gelicol are the main raw materials for polycrethane elastomers, and are used in various lubricants, solvents, pressure fluids, etc. It is an industrially useful polymer.

These polyether polyols are conventionally synthesized by ring-opening polymerization of cyclic ethers such as tetrahydrofuran (hereinafter referred to as TI (hereinafter referred to as P)).These known methods include a polymerization step, adding condensate to hydrolyze the polymer, and converting the terminals into OH. In this case, the polymerization catalyst is a super strong acid such as fluorosulfonic acid, fuming sulfuric acid, or perchloric acid - acetic anhydride, Nafion resin (fluorinated sulfonic acid resin) -
A system in which an acid anhydride is combined with a proto-acid or a Lewis acid such as acetic anhydride, BF, -HF-acetic anhydride, etc. is used.

(Problems to be Solved by the Invention) In these conventionally known methods, the terminal end of the polymer immediately after polymerization is not a hydroxyl group, but is terminated as, for example, a -8o3H group or a 10C0CR3 group, and this is injected with water or alkaline water. It is necessary to add and hydrolyze the terminal to form a hydroxyl group, which causes many industrial disadvantages.

For example, the hydrolysis of terminal acetyl groups obtained in the presence of acetic anhydride is carried out under reflux to avoid even traces of acetyl groups remaining. It requires harsh conditions such as 100%, requires alkali, and consumes acetic anhydride, making it difficult to recycle the acid catalyst.

In addition, when using a fluorosulfonic acid catalyst, hydrolysis of the generated 5o3H group easily proceeds by simply adding water, but the fluorosulfonic acid is decomposed into hydrogen fluoride and sulfuric acid, requiring a large amount of expensive reagents. As well as consuming
A large amount of equipment investment had to be made to treat the generated HF, etc.

(Means for solving the problem) The present inventors previously filed an application for a method of synthesizing PTMG by dehydrating and condensing 4 with monobutanediol using a heteropolyacid (patent application Shoj Turf). 3rd evening 23).

Furthermore, the present inventor carried out dehydration condensation polymerization of polyhydric alcohol, and -
As a result of intensive research into a method for synthesizing polyalkylene ether polyols having terminal OH groups, it was discovered that the objective could be achieved by carrying out the reaction in the presence of a heteropolyacid and/or its salt, and the present invention was accomplished. reached.

That is, the present invention per 7 molecules/! In the presence of a heteropolyacid and/or a salt thereof in which submolecular water is coordinated or present,
This is a method for producing polyalkylene ether polyol, which is characterized by subjecting alcohols having two or more hydroxyl groups in seven molecules to dehydration condensation polymerization. (However, alcohol
butanediol, except when the catalyst is a free heteropolyacid. )Heteropolyacids and their salts (hereinafter sometimes referred to as heteropolyacids) are usually synthesized as a hydrate with a θ~<10, although they differ depending on the type C9. However, no polymerization activity was observed at all.

However, after drying the above heteropolyacids to change their hydration number, the polymerization activity was examined and the hydration number was /! Particularly preferably, when the following compounds are selected from / to ♂, polymerization activity unexpectedly appears, and polyether polyols are directly synthesized by dehydration condensation of polyhydric alcohols.

In particular, polyether polyols were synthesized in higher yields when the hydration number was ♂ or less.

As the dehydration condensation reaction of polyhydric alcohols progresses, water is produced, so the amount of water in the system is the same as that of the heteropolyacids. If the amount exceeds twice the molar amount, polymerization activity disappears. Therefore, in order to continue the reaction, the hydration number of the heteropolyacid and its salt must be 7! It is necessary to maintain the following.

A method of keeping the hydration number of heteropolyacids below /1 is to carry out the reaction while continuously or intermittently adding anhydrous heteropolyacids to reduce the hydration number of heteropolyacids in the entire system to /! The following methods are used: the heteropolyacid catalyst is continuously or intermittently extracted from the reactor and returned to the reactor after dehydration treatment, and the reaction is carried out while water is removed from the reactor by distillation.

The heteropolyacid and its salt in the present invention include Mo, W,
At least one oxide of V and other elements such as P, 8i, λs, Ge, B, Ti, C
e.

It is a heteropolyacid and its salts, which is a general term for ochonic acids produced by condensation of ochonic acids such as Co.

Specific examples of these heteropolyacids and their salts include phosphomolybdic acid, phosphotungstic acid, phosphomolybdotungstic acid, phosphomolybdovacadic acid, phosphomolybdotungstovanadate, phosphotungstovanadate, phosphomolybdoniobic acid, Tungstic acid, silicon molybdic acid, silicon molybdo tungstic acid, silicon buttungstovanadic acid, germanium tungstic acid, borotungstic acid, boromolybdic acid, boromolybdotungstic acid, boromolybdopanadic acid, boron These are molybdotungstovanadate, cobalt molybdic acid, cobalt tungstic acid, arsenic molybdic acid, arsenic tungstic acid, titanium molybdic acid, cerium molybdic acid, and salts thereof. The type of salt is not particularly limited, but for example,
Periodic table 111jc of Li, Na, K, Rh, Ca, Cu, Ag%Au, etc.

Mg, Ca, Sr, Ba%N group such as Zn, Cd, Hg, Sc, La1lCe%AU,%Ga,
Group ■ of In et al., Fa.

Group 1 such as Co, Ni, Ru, Pd%PL, metal salts such as 8n, PblMn, Bi, ammonium salts, amine salts, etc. Heteropolyacid salts are prepared by adding aqueous solutions of heteropolyacids to carbonates or nitrates of each metal, ammonia,
Prepared by titration with amine and evaporation to dryness.

The heteropolyacid and its salt used in the present invention exist in a solid phase or dissolved in the polyhydric alcohol. The hydration number can be adjusted by heating the heteropolyacid or its salt to a high temperature or by maintaining it at a relatively low temperature and under reduced pressure.

The amount of heteropolyacids used is not particularly limited, but if the amount of heteropolyacids in the reactor is small, the polymerization rate will be low and the 0. θ7 to 20 times the weight, preferably θ
, /~70 times the weight is used.

In order to carry out the reaction without removing the generated water from the system, the number of coordinated waters of the heteropolyacids must be increased by /! It is necessary to adjust the amount of heteropolyacids used so as not to exceed 1; Otherwise, the number of coordinated waters of heteropoly t*a is /
! The polymerization activity disappears when the temperature exceeds 100%, and the yield of polyalkylene ether polyol becomes low.

The alcohol having C2 or more hydroxyl groups in seven molecules used in the present invention may be any alcohol as long as it does not have a substituent that inhibits the activity of the catalyst.

For example, 1,3-propanediol, /, 4L-butanediol, /, 3-butanediol, /, J″-bentanediol, 1,6-hequinanediol, neopentyl glycol, glycerin, diethylene glycol, triethylene glycol , dipropylene glycol, etc.

A terminal C nialkoxy V group can also be introduced by the presence of a monoalcohol as the alcohol.

The reaction temperature is preferably 0 to 200°C, particularly 30 to 700°C. When the temperature exceeds 200°C, the yield decreases dramatically, and below 0°C, the reactivity is extremely low and has no practical value.

The time required for the reaction varies depending on the amount of catalyst and the reaction temperature (θ, j~jθ time).

The reaction can be carried out while stirring the polyhydric alcohol and the heteropolyacid having a predetermined hydration number and/or its salt.
Although a solvent is not particularly required, an inert solvent may be added to the reaction.

The reaction format is not particularly limited and may be a commonly used reactor such as a seed type or base type reactor. Moreover, either a batch type or a continuous type can be carried out. The catalyst may be supported on activated carbon, silica alumina, etc. and used as a fixed bed or a fluidized bed.

After the polymerization reaction, the catalyst is separated from the polyether polyol by filtration if the catalyst is in a solid phase, by phase separation if the catalyst is a liquid and separated into two phases, or by extraction etc. if the catalyst is uniformly dissolved. Separate. The recovered catalyst can be used repeatedly by adjusting the hydration number.

Although the mechanism of this reaction is not clear, it is thought that the OH group of the polyhydric alcohol is dissociated on the catalyst, and polymerization proceeds from this.

(Effects) By the method of the present invention, polyalkylene ether polyols having an OH group at the terminal can be synthesized.

In addition, conventionally, tetrahydrobicune (pentamethylene oquinide) did not have ring-opening polymerizability, making it difficult to synthesize polyoquine pentamethylene glycol, but it has been found that it can be synthesized according to the present invention. Sara (:, used in the present invention,
Heteropolyacids and their salts have the advantage of being less corrosive and can be reused.

(Example) The present invention will be explained below with reference to Examples.

Example: In a container equipped with a stirrer, add butanediol.
j, prepare 4 f. Then, 2-tungstophosphoric acid-/-9f was heated at 2-0°C for 3 hours to make it anhydrous.
Add 9/2 of r7 A (LiH, FW!, O,) (the number of moles of l-butanediol at this time is about 73 times the number of moles of phosphotungstate, and even after the dehydration condensation reaction The number of coordinated waters in a heteropolyacid salt does not exceed /!). Seal the container and set the temperature to 2J℃ for 30 minutes.
Stir for hours. Phosphortungstate initially exists as a solid phase, but as the dehydration condensation reaction progresses, it uniformly dissolves. After reaction, add water λ00f and chloroform 2001 to the yarn.
is added, shaken, and then separated into two phases. The catalyst is recovered from the aqueous phase. Unreacted 7, from the chloroform phase
By removing 4t-butanediol and chloroform by distillation (a polymer of 2, /, Of was obtained. As a result of infrared spectrum and NMR spectrum measurements, the polymer had O at both ends.
It was determined that it was an H group and that it was PTMG. The PTMG obtained as a result of gel permeate chromatography (GPC) measurement had a number average molecular weight θO with a molecular electric distribution ranging from several hundred to several thousand.

Comparative Example The same operation as in Example was carried out except for using coated tungstophosphoric acid-7-lytecum with a coordinating water number of 76, but no polymer was obtained from the chloroform phase.

Example Co/j A container C2 equipped with a stirring device and a reflux condenser is charged with 3j1 portions of butanediol. Then, the anhydrous table-
Add the various heteropolyacid salts shown in /. Set the temperature to θ℃, /! After stirring for a certain period of time, the solid catalyst is removed by filtration, and then water 2001 and chloroform 2001 are added to liquid F and stirred, followed by separation into two phases. PTMG was obtained by removing unreacted butanediol and chloroform from the chloroform phase by distillation.

The number average molecular weight (GPC analysis value) and yield of the obtained PTMG are shown in Table 1.

(Leaving space below) Table-/ Example/6 In a container equipped with a stirring device and a reflux condenser, /, turpentanediol 100? Prepare. Then, in anhydrous state (diphosphotungstic acid (H3PW1.O@) = 00f and sodium phosphotungstate (NaHlPWHOm)
Add 2 Of. After setting the temperature to 60°C and continuing stirring for /j hours, water J″00? and chloroform
Add t and stir, then allow to separate into two phases. Polyoxypentamethylene glycol/,♂t was obtained by removing unreacted /,j-bentanediol and chloroform from the chloroform phase by distillation. As a result of GPC measurement, the number average molecular weight was 2jO.

Example/7 1001, which is 6-hechitinediol, is charged into a container equipped with a stirring device and a reflux condenser. Next, anhydrous phosphotungstic acid (HxPW12046) was added to 3002
Add. After setting the temperature to 60℃ and continuing stirring for 50 hours, water! 00t and chloroform! θθ? is added, stirred, and then separated into two phases. Unreacted 6-hexanediol and chloroform are removed from the chloroform phase by distillation to form polyoxane hequinamethelene glycol. I got it. The number average molecular weight was 24tθ as a result of GPC measurement.

Claims (1)

[Claims] In the presence of a heteropolyacid and/or its salt in which 15 molecules or less of water are coordinated or present per molecule, 2
A method for producing a polyalkylene ether polyol, characterized by dehydration condensation polymerization of alcohols having 1 or more hydroxyl groups (however, the alcohol is 1,4-butanediol,
(except when the catalyst is a free heteropolyacid).