JPS59199715A - Preparation of polyether polyol derivative - Google Patents

Abstract

PURPOSE:To obtain a terminal amino group-containing polyether polyol simply by one stage reaction, by reacting a specific polyoxyalkylene polyol with a specified amount of aminobenzoic acid in the presence of a specific amount of aliphatic alcohol. CONSTITUTION:1 mole n hydric polyoxyalkylene polyol having 400-40,000mol. wt. (preferably 2-3 hydric polyoxytetramethyleneglycol having 1,000-4,000mol. wt. etc.) is reacted with 0.125-1.2 n mole aminobenzoic acid in the presence of 0.125-30 n equivalent aliphatic alcohol, to give the titled derivative shown by the formula [n is 2-8; x is average value, 0-(n-1); A is residue of n hydric polyoxyalkylene polyol obtained by eliminating hydroxyl group from n hydric polyoxyalkylene polyol having 400-10,000mol.wt.] having hydroxyl groups of n hydric polyoxyalkylene polyol replaced with aminobenzoic acid ester, and one or more terminal amino groups.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides polyethers having at least one terminal amino group to provide cypolyurethane ureas by polyaddition reaction with polyisocyanates, and polyethers having at least one terminal amino group to provide cypolyurethaneureas. Polycondensation provides polyesteramide, which is a useful compound as a raw material for elastomer and plastic synthesis. It can also be used as an initiator for ring-opening polymerization of epoxy compounds.

Regarding polyethers having terminal amino groups, for example, in JP-A-46-5245, polyether polyols and isatoic anhydride are reacted in the presence of a strong base such as sodium hydroxide to form anthranilic acid esters of polyethers. It describes how to obtain it. However, this method concerns polyethers having an amino group at the ortho position, and cannot synthesize polyethers having an amino group at the para position.

In order to obtain stronger mechanical strength and higher heat resistance in elastomers and plastics obtained from polyethers containing terminal amino groups, it is preferable that the amino compound be an ortho-amino compound such as anthranilic acid ester.
Para-amino derivatives such as para-aminobenzoic acid ester are preferred.

In addition, JP-A-50-132096 describes bispara-aminobenzoic acid esters of propanediol or bentanediol, but these amino compounds are low molecular weight compounds, and their production also involves reacting diol with paranitrobenzoyl chloride. This method is difficult to apply to high-molecular-weight polyether polyols, as it is a multi-step synthesis method in which polyether polyols are converted into diamines and then reduced to diamines.

Further, U.S. Pat. No. 4,328,322 discloses a para-aminobenzoic acid ester of a polyol in which all terminal hydroxyl groups of the polyol are converted to amino groups by reacting the polyol with para-nitrobenzoic acid chloride and then reducing the nitro groups. has been done.

In contrast, in the present invention, the terminal ends of the polyether polyol are partially or entirely made of aminobenzoic acid ester. The polyether polyol derivative of the present invention is characterized in that its production is completed by substantially one-stage reaction, the yield is high, and purification is not required. On the other hand, the polyamine disclosed in the above US patent requires a two-step reaction of esterification reaction with acid chloride and reduction reaction of nitro group, and also requires purification.

The object of the present invention is to have an amino group at the end.

The object of the present invention is to provide a method for producing polyether polyol derivatives having terminal amino groups and hydroxyl groups by a simple, single-step process.

In the present invention, 0.125 n -1,2 n mole of aminobenzoic acid is added to 0.125 n -30 n mole of n-valent polyoxyalkylene polyol having a molecular weight of 400 to 10,000.
The general formula is characterized in that the reaction is carried out in the presence of n equivalents of aliphatic alcohol [n is an integer of 2 to 8,
), A indicates a molecular weight of 400 to 10,000.
This shows the n-valent polyoxyalkylene polyol residue obtained by removing the hydroxyl group from the n-valent polyoxyalkylene polyol. ] According to a method for producing a polyether polyol derivative having at least one terminal amino group on average, in which at least one hydroxyl group of an n-valent polyoxyalkylene polyol represented by the formula is substituted with an aminobenzoic acid ester. .

Suitable polyoxyalkylene polyols used in the present invention include one or more alkylene oxides such as ethylene oxide, propylene oxide, and tetrahydrofuran in the presence of a suitable initiator such as water, a low molecular weight polyol, or a low molecular weight amine. Examples include polyether polyols having a valence of 2 to 8 and having a molecular weight of 400 to 10,000, which are addition-polymerized in any order, and which can be obtained by known methods.

Examples of low molecular weight polyols suitable as the above-mentioned initiators include ethylene glycol, propylene glycol,
■, 4-butanediol, 1,6-hexanediol,
Examples include glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, hydroquinone, a2-bis(4-hydroxyphenyl)propane, and low molecular weight amines include methylamine, butylamine, ethylenediamine, aniline, and tolylene diamine. Examples include amines, and alkanolamines such as ethanolamine, jetanolamine, and triethanolamine can also be used.

When using the polyether polyol derivative of the present invention having at least one terminal amino group obtained from the polyoxyalkylene polyol described in 2 as a raw material for elastomer synthesis, it has a molecular weight of 1,000 to 40,000.
Divalent to trivalent polyoxytetramethylene glycol, polyoxypropylene polyol, polyoxypropylene polyoxyethylene polyol, etc. are suitable. In addition, when used as a synthetic raw material for plastics, the molecular weight is 400~
1500 tri- to octavalent polyoxypropylene polyol is preferred. .

The aminobenzoic acid used in the present invention may be ortho, meta or para-aminobenzoic acid, but para-aminobenzoic acid is particularly suitable when the polyether polyol derivative of the present invention is used as a synthetic raw material for elastomers or plastics.

Various types of aliphatic alcohols can be used in the present invention, and preferred examples include evaporated methanol, ethanol, propatool, butanol, hexanol, octatool, cyclobutanol, cyclopentanol, cycloheptatool, etc. Chain or cyclic monoalcohol of numbers 1 to 8, ethylene glycol, propanediol, butanediol, hexanediol,
Examples include diols having 2 to 8 carbon atoms such as heptanediol.

The polyether polyol derivative of the present invention is produced by carrying out an esterification reaction and a transesterification reaction continuously in the same reaction system from the above divalent to octavalent polyoxyalkylene polyol having a molecular weight of 400 to 100, aminobenzoic acid, and an aliphatic 1° alcohol. It can be obtained in high yield depending on the method.

In the present invention, aminobenzoic acid is 0.125 n to 1 mole of di-n-valent polyoxyalkylene polyol.
Preferably, 1.2 nmol is reacted in the presence of 0.125n to 801 equivalent aliphatic alcohol.

In general, in the aminobenzoic acid used in the present invention, it is known that carboxyl groups with amino groups in the meta position are difficult to decarboxylate, but carboxyl groups in the ortho or para positions are easily decarboxylated ( For example, supervised by Fujio Kotake, Large Organic Chemistry, 10 Aromatic Compounds ■, 170-174
Page, Breakfast Bookstore). When aminobenzoic acid is decarboxylated, the desired polyether polyol derivative having a terminal amino group can be obtained. In fact, in the process of arriving at the present invention, an attempt was made to esterify ethylene glycol and para-aminobenzoic acid, but when heated for 3 hours at the reflux temperature of ethylene glycol, 195-200'C, the esterification reaction was approximately 50% It was found that the formation of aniline by decarboxylation of para-aminobenzoic acid occurred approximately 50% of the time.

On the other hand, the applicant's earlier application, Japanese Patent Application No. 57-165447,
In the transesterification reaction between polyoxyalkylene polyol and para-aminobenzoic acid alkyl ester, side reactions do not substantially occur, and a polyether polyol derivative having the desired terminal amino group can be obtained. This shows that para-aminobenzoic acid and cypara-aminobenzoic acid alkyl esters have greater thermal stability and that the desired polyether polyol derivatives having terminal amino groups can be obtained in high yield. Shijina 7% Rahala Aminobenzoic acid alkyl ester is synthesized by esterification reaction with alcohol using para-aminobenzoic acid as a raw material, so if a polyether polyol derivative having a terminal amino group can be directly synthesized from para-aminobenzoic acid, It has great industrial value.

Therefore, the present inventor conducted an esterification reaction and a transesterification reaction sequentially in a system consisting of a polyoxyalkylene polyol, an aminobenzoic acid represented by para-aminobenzoic acid, and an aliphatic alcohol such as ethylene glycol. When 0.125 n-1.2 n mol of aminobenzoic acid is reacted with 1 mol of polyoxyalkylene polyol in the presence of 0.125 n to 301 equivalents of aliphatic alcohol, desorption of aminobenzoic acid is achieved. The present invention has been achieved by discovering that the production of aniline by carbonic acid is extremely low and that the desired polyether polyol derivative having an amino group at the end can be obtained in high yield.

Although the present invention seems to contradict the results of the reaction of the aliphatic alcohol ethylene glycol with para-aminobenzoic acid, the decarboxylation of aminobenzoic acid is not fully understood yet. It can be inferred that the ease of reaction depends on the concentration of hydroxyl groups in the reaction system, and it is considered that the object of the present invention can be achieved within the preferred range of the aliphatic alcohol.

The polyether polyol derivative obtained by the method of the present invention is an esterified product in which all terminal hydroxyl groups are converted to amino groups, or a partially esterified product in which some unreacted hydroxyl groups remain, and the esterification rate is The degree of conversion can vary over a wide range depending on the application, and it is necessary that on average at least one hydroxyl group of the polyether polyol is esterified, and preferably the esterification rate, that is, the amine conversion The ratio is about 50-100%.

The above esterification reaction and transesterification reaction of the present invention are carried out without a catalyst or in the presence of a known esterification catalyst, usually at a temperature of 150 to 250°C, using an inert gas such as nitrogen gas.
This is achieved by heating to a temperature to perform dehydration and dealcoholization. When using a catalyst, a weakly acidic or weakly basic catalyst that does not produce ether or olefin by dehydration of the polyol is preferable, such as metal oxides such as antimony trioxide, -lead oxide, tetraisopropyl titanate, and tetrabutyl. Examples include organic titanium compounds such as titanates, alkaline earth metal salts of weak acids such as calcium acetate, and organic titanium compounds are particularly preferred. The amount of catalyst is usually less than too ppm. In addition, an inert solvent and a coloring inhibitor such as triphenyl phosphate can also be used in the reaction. The reaction is first carried out until the end of water distillation, but it is also possible to remove the water and remove excess aliphatic alcohol at the same time without separating it, or to separate water and aliphatic alcohol and remove only water. A method may also be used in which the aliphatic alcohol is distilled off and returned to the reaction system.

The reaction is then continued until the aliphatic alcohol has been distilled off.
Furthermore, the pressure of the system may be reduced to completely distill off the alcohol and, if present, excess aminobenzoic acid. No particular purification is required.

The reaction of the present invention is estimated as follows from the results of gel permeation chromatography analysis of the reaction system.

That is, the reaction first proceeds from an esterification reaction between the C0OH group of aminobenzoic acid, the OH group of the polyoxyalkylene polyol, and the OH group of the aliphatic alcohol. The reaction system is C0O
It consists of an excess of OH groups relative to H groups, increasing the esterification reaction rate. When the esterification reaction is completed, the transesterification reaction proceeds, and the unreacted OH groups of the polyoxyalkylene polyol and the ester of the aliphatic alcohol and aminobenzoic acid undergo a transesterification reaction to convert the unreacted OH groups of the polyoxyalkylene polyol to the ester of the aliphatic alcohol and aminobenzoic acid. The reactive OH group is esterified and the aliphatic alcohol is distilled out of the system. Although aminobenzoic acid has poor thermal stability, aminobenzoic acid alkyl esters have high thermal stability, so it is thought that the desired polyether polyol derivative of the present invention can be obtained in high yield.

A detailed explanation will be given below using examples.

Example 1 Polytetramethylene glycol (Mitsubishi Kasei PTMGI5
00, MW1498) 49.931? (0,033
3 mol), para-aminobenzoic acid (Gyudon Chemicals, Reagent G
R,)9.14ii' (0,067 mol), ethylene glycol 4138f (Q, 667 mol), and tetrabutyl titanate 0051 were heated in a four-eye flask equipped with a stirrer and a cooler through dry nitrogen gas. When the temperature was raised to 180°C, ethylene glycol refluxed, and when the temperature was further raised to 209°C, ethylene glycol began to distill out.

After further heating and raising the temperature to a range of 220-240°C and holding it for 1 hour 20 minutes, samples were taken from the four-eye flask and analyzed by gel permeation chromatography. It was hardly detected. In addition, the amount of mixed liquid of distilled ethylene glycol and water produced by reaction was 2,827.

Then at a temperature of 220-240°C, 2.5-60 hours
The remaining ethylene glycol was distilled off under reduced pressure at 30°C.
A reddish brown liquid with a viscosity of 6500 cps was obtained.

The production of polyether polyol derivatives having terminal amino groups was confirmed using the following analytical method. That is, the amine value was determined to be 0.9 by titration with perchloric acid in glacial acetic acid (Analytical Chemistry Handbook, revised 3rd edition, page 261).
04meQ/f, and a hydroxyl value measurement method (JIS K 1557) that can measure the total amount of hydroxyl groups and amino groups.
According to the report, it was 1.210 meq/f. When the product was analyzed by gel permeation chromatography, no free para-aminobenzoic acid was detected, except for a slight peak that was presumed to be a reaction product of ethylene glycol and para-aminobenzoic acid. Raw material PTMGI 50
A single peak with a molecular weight distribution similar to 0 was obtained.

The above analysis results indicate that 75% of the terminal hydroxyl groups of PTMG 1500 were converted to amino groups.

Example 2 PTMG 1500 (MW 1498) 606.1
ii' (Heat in a four-eye flask fitted with a 0,405 tube while passing dry nitrogen gas until the temperature reaches 228°C.
Then the ethylene glycol began to reflux.

Furthermore, when the temperature is raised to 230°C and the lower part of the fractionating tube is kept warm, the ethylene glycol refluxes violently, and the ethylene glycol and the water produced by the reaction begin to separate at the upper part of the fractionating tube. Temperature rose from 93°C to 9
The temperature is constant at 9°C.

When this state is maintained for 4 hours, the amount of water produced by the reaction is about 13. ! i' got it. Further, when a sample was taken from the four-eye flask and analyzed by gel permeation chromatography, free para-aminobenzoic acid was reduced to less than 10% of the total amount of para-aminobenzoic acid.

Further, the reaction system was maintained at 230°C and heated for 3 hours until the temperature at the top of the fractionating tube decreased to 50°C and water was distilled out.

Next, at a temperature of 220°C and under a reduced pressure of 8 to 12 mmHf,
Distill ethylene glycol for 3 hours, then 2ttrr
Ethylene glycol was distilled off under reduced pressure of ttHy for 4 hours. Yield 6951t', viscosity at 1°C 680
A reddish-brown liquid of 0 C1)S was obtained.

The amine value of this reaction product was 1.15 meq/f, and the total amount of amino groups and hydroxyl groups was 1.25 meq/f.

``Therefore, 92% of the terminal hydroxyl groups of the polyol have been converted to amino groups.

Example 3 PTMG] 500 (MW 1498) 52
4. ．． 8? (0,350 mol), para-aminobenzoic acid 95.99 g (0,700 mol), n-butanol 77
83 g (1,050 mol) of tetrabutyl titanate and 0.349 f of tetrabutyl titanate were heated in a Yotsuro flask equipped with a stirrer and a fractionating tube while passing dry nitrogen gas.
At 20°C, n-butanol began to reflux. Furthermore, when the temperature is increased to 225°C, n
-Butanol and water produced by the reaction begin to separate, and the temperature of the steam remains constant at 99°C.

The reaction system was maintained at 225°C, and the temperature at the top of the fractionating tube was 40°C.
The mixture was heated for 8 hours until the temperature dropped to 0.degree. C. and no more water distilled out. Next, n-butanol was distilled off at a temperature of 220° C. under a reduced pressure of 35 to 50 yttmHf for 6 hours.

Yield 598g, viscosity at 30°C 6850cps
A reddish brown liquid was obtained.

The amine value of this reaction product is ]-, l 2 meq/f
The total amount of amino groups and hydroxyl groups was 1.26 meq/f.

Therefore, 89% of the terminal hydroxyl groups of the polyol were converted to amino groups. (above) Patent applicant Toyo Rubber Industries Co., Ltd. Agent Patent attorney Tamura
Iwao 19-

Claims (1)

[Claims] (1) 0 aminobenzoic acid per mole of n-valent polyoxyalkylene polyol with a molecular weight of 400 to 10,000
．． 125n to 1.2nmol to 0.125n to 30n
General formula [n is an integer of 2 to 8, X is an average value, O to (n-1
), A indicates a molecular weight of 400 to 10,000.
This shows the n-valent polyoxyalkylene polyol residue obtained by removing the hydroxyl group from the n-valent polyoxyalkylene polyol. ] A method for producing a polyether polyol derivative having at least one terminal amino group on average, in which at least one hydroxyl group of an n-valent polyoxyalkylene polyol represented by the formula is substituted with an aminobenzoic acid ester. .