JP3140109B2 - Purification method of polyethers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purification method for removing alkali metal halides from high molecular weight polyethers containing a small amount of alkali metal halides.

[0002]

2. Description of the Related Art The viscosity of high molecular weight polyethers (for example, polyoxyalkylene poly (or mono) ol and derivatives thereof) increases as the molecular weight increases. When purifying high molecular weight polyethers to remove impurities contained therein, the purification treatment becomes more difficult as the polyethers have higher viscosity. Also, the high viscosity of the polyethers makes the process more difficult when the impurities are small and must be sufficiently removed.

When a derivative is produced by converting a terminal hydroxyl group of a polyoxyalkylene poly (or mono) ol into another organic group or the like, the hydroxyl group is converted to an alkali metal alkoxide.
Reduction was, it is possible to produce a derivative by reacting an organic halide. Specifically, for example, in the case of producing a derivative as a terminal allyl group by reacting allyl chloride as an organic halide, or in the case of reacting with a polyhalogenated hydrocarbon such as methylene chloride to multiply polyether, etc. is there.

[0004] At that time, without an alkali metal halide by-, must be the by-product sufficiently removed from any case derivatives photons. However, if the derivative has a high viscosity, removal of this by-product becomes extremely difficult.

The production of polyethers having a terminal alkenyl group will be specifically described below as an example.

Polyethers having a terminal alkenyl group can be useful intermediates of functional group-containing polyethers because various functional groups can be introduced by utilizing the olefin group and by further chemical modification such as addition reaction. The synthesis method and purification method have been studied so far. A well-known method is to react a hydroxyl group of a polyether polyol having a terminal hydroxyl group with an alkenyl chloride such as allyl chloride or methallyl chloride in the presence of a base to obtain an alkenyl terminal group.

[0007] In this method, when using an alkali metal hydroxide or sodium metal as the base For example in the reaction, inorganic salts such as sodium chloride is by-produced.
When such an inorganic salt is by -produced or when an excess of base is used, it is necessary to remove the remaining base. For the removal , a method of treating with an appropriate adsorbent and filtering, a method of neutralizing with various acids and then filtering a salt formed, and a method of extracting are known.

[0008]

However, as described above, high-molecular-weight polyethers are difficult to filter because of their high viscosities. Furthermore, in the case of high-molecular-weight polyethers, salts generated by neutralization are finely dispersed and cannot be easily filtered. In addition, even if the extraction method is used, high-molecular-weight polyethers form a creamy mixture in which the polymer layer and the aqueous layer cannot be separated at all by a simple washing method, and easily become an emulsion even when a solvent is used. Cannot be separated.

After dilution with a water-insoluble organic solvent, the pH of the aqueous layer is
There is also known a method of performing liquid separation by using a combination of the above-mentioned control and a surfactant, but there are great restrictions, for example, it is difficult to use polyethers having high hydrophilicity. Therefore, it is desired to establish a highly versatile purification method for not only polyethers having a terminal alkenyl group but also high-molecular-weight polyethers having the above properties.

[0010]

The present invention is the following invention which has been made to solve the above-mentioned problems. That is, after adding a surfactant and water to a high molecular weight polyether containing a small amount of an alkali metal halide, dehydration is performed, and then the alkali metal halide is filtered or centrifuged.
This is a method for purifying polyethers, which is characterized by being removed by a core separation method .

The high-molecular-weight polyether containing a small amount of an alkali metal halide includes the above-described high-molecular-weight polyether having a hydroxyl group and a halogenated hydrocarbon in the presence of an alkali metal or a basic alkali metal compound. Nima other high molecular weight polyether having a hydroxyl group
Water group after alkali metal alkoxide of the product obtained by reacting it is appropriate. In addition, it has a hydroxyl group.
The alkoxylation of the hydroxyl group portion of the high molecular weight polyether can be carried out simultaneously with the reaction with the halogenated hydrocarbon .

As the high molecular weight polyether having at least one hydroxyl group, which is a raw material of the polyether in the present invention, polyoxyalkylene poly (or mono) ol is preferable. The molecular weight is not particularly limited, but is preferably 1000 or more. It is preferably from 1,000 to 50,000, particularly preferably from 300 to 50,000.
0 to 50,000. The number of hydroxyl groups is 1 or more, 1 to 6 is appropriate, and preferably 2 to 4.

[0013] The polyoxyalkylene (or mono) ol, the presence of a catalyst monoepoxide in Initiator, is is preferable that obtained especially by reacting an alkylene oxide having 3 to 6 carbon atoms. Initiator is a compound having a reactive site corresponding to the number of the hydroxyl group (the hydrogen atom of the hydroxyl group or amino group), for example, there is a monovalent or polyvalent alcohols or phenols.

[0014] as a Initiator, especially divalent to tetravalent alcohol or alkylene oxide adducts thereof (polyoxyalkylene polyol as compared to the desired product low molecular weight) is preferable.

[0015] Although as the Initiator is appropriate 1-6 dihydric alcohol or phenol, but are not limited to,
For example, mono- to hexavalent carboxylic acids, amines, thiols and the like can be used. When producing a polyether having a terminal alkenyl group, a monovalent alkenyl alcohol as a Initiator (e.g., allyl alcohol) Initiator having an alkenyl group such as is preferred. Is a divalent or higher <br/> Initiator, for example, the following compounds.

Ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and other polypropylene glycols, butanediol, glycerin, trimethylolpropane, pentaerythritol, bisphenol A and alkylene oxide adducts thereof.

As the monoepoxide, a compound having 3 to 3 carbon atoms is particularly preferable.
6 alkylene oxides are preferred. Examples of the alkylene oxide having 3 to 6 carbon atoms include propylene oxide, butylene oxide, hexylene oxide, and styrene oxide. Particularly preferably, propylene oxide alone or propylene oxide and a small amount of other carbon
It is a combination of the above alkylene oxides.

Alkali catalysts are well known as catalysts used in the production of polyoxyalkylene poly (or mono) ols. The alkali catalyst is usually made of an alkali metal or a compound thereof, and is considered to have an alkoxide of a hydroxyl group and exhibit a catalytic action.
However, when an alkali catalyst is used, the upper limit of the molecular weight of the polyoxyalkylene poly (or mono) ol obtained due to a side reaction is limited, and for example, in the case of a diol, it is at most about 4000.

In order to produce a higher molecular weight product,
It is preferable to use a double metal cyanide complex catalyst or a porphyrin metal complex catalyst. These complex catalysts are known as alkylene oxide addition catalysts.

As a method of reacting a halogenated hydrocarbon with a hydroxyl group of a high molecular weight polyether having at least one hydroxyl group, the hydroxyl group is converted to an alkali metal such as sodium or potassium, an alkali metal hydride such as NaH, NaOR (R is reacted methyl, ethyl, propyl, isopropyl, metal alkoxides such as an alkyl group such as butyl), an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, alkoxy de
And then reacting the halogenated hydrocarbon.

Alternatively, when a basic alkali metal compound such as an alkali metal hydroxide is used, a method of reacting with a halogenated hydrocarbon in the presence of such a compound can be used. Hereinafter, these alkali metals and their compounds are simply referred to as bases.

By this reaction, high molecular weight polyethers containing an alkali metal halide are obtained. The amount of the alkali metal halide is usually smaller as the higher molecular weight polyether is higher. Usually the amount is up to 5% by weight, often up to 2% by weight, based on high molecular weight polyethers. The lower limit can vary depending on the need for purification, but usually,
It is about 0.1% by weight.

The amount of the alkali metal halide in the polyether purified according to the present invention can also vary depending on the purpose, but it is suitably 1/10 or less of the unpurified amount. It is preferably at most 1/10 of the unpurified amount and less than 0.1% by weight. In many cases, polyethers before purification is contained the above base, the base is also removed by the purification process of the present invention.

As described above, as the halogenated hydrocarbon in the present invention, a polyhalogenated hydrocarbon having 4 or less carbon atoms or a monohalogenated hydrocarbon having 8 or less carbon atoms is suitable.

As the halogen, chlorine or bromine is suitable. Particularly, a dichlorohydrocarbon having 1 to 2 carbon atoms or a monochlorohydrocarbon having 6 or less carbon atoms is preferable.
As mentioned above, alkenyl halides are most preferred, especially alkenyl chlorides. As the alkenyl halide, allyl chloride and methallyl chloride are particularly preferred.

The amount of alkenyl halide used can be arbitrarily changed depending on what percentage of the total amount of hydroxyl groups of the high molecular weight polyether having hydroxyl groups is converted to alkenyl groups. Any equivalent can be used with respect to the hydroxyl group of the high molecular weight polyether having at least one hydroxyl group. However, when all the hydroxyl groups are converted to alkenyl groups, an excess equivalent is generally used with respect to the hydroxyl group. The upper limit of the equivalent is suitably about 1.3 times .

The number of alkenyl groups per molecule in the resulting high molecular weight polyethers is from 1.6 to 1.6.
6, particularly preferably 1.8 to 3. The obtained high molecular weight polyethers may have a hydroxyl group which is not converted into an alkenyl group.

[0028] In the production of polyoxyalkylene monol, allyl alcohol, to produce a polyoxyalkylene monool using Initiator having an alkenyl group such as methallyl alcohol, alkenyl and the hydroxyl group by the methods described above it is also possible number of alkenyl groups producing ultra El high molecular weight polyethers a 1 turned into.

[0029] The present invention with an alkali metal halide (hereinafter, will have both salts) from high molecular weight polyether containing an alkali metal halide to remove the surfactant and water was added to the polyether Extracting alkali metal halides in high molecular weight polyethers with water,
The salt is precipitated by dehydration to form salt crystals having a size that can be easily removed.

The use of this water is particularly effective when the base may partially precipitate depending on the content of the base in the high-molecular-weight polyether to be purified or the polarity of the high-molecular-weight polyether. It is a way.

In the present invention, the use of a surfactant is essential. The surfactant used in the present invention is preferably a surfactant generally known as a nonionic surfactant. In the present invention, a compound having an oxyethylene chain in a molecule of 5% by weight or more is particularly preferable among nonionic surfactants.

Specific nonionic surfactants include :
Polyoxyethylene aliphatic alkyl ether, polyoxyethylene polyoxypropylene aliphatic alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene monoaliphatic carboxylic acid ester, sorbitan mono or polyaliphatic ester, polyoxyethylene sorbitan monofatty acid esters, polyoxyethylene polyoxypropylene block copolymers, polyoxyethylene or polyoxyethylene fatty amines, fatty acid di-alkanolamides, glycerol mono-fatty acid esters,
Examples include, but are not limited to, polyglycerin fatty acid esters, propylene glycol fatty acid esters, pentaerythritol fatty acid esters, and the like.

The amount used is high molecular weight polyethers 1
The ratio is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 1 part by weight, per 100 parts by weight.

If the amount of the surfactant is less than 0.01 parts by weight, the salt may remain in the polyether even if the salt precipitated later is removed, or the state in which the salt is finely dispersed. And it is very difficult to remove salts from polyethers. If the amount of the surfactant is more than 5 parts by weight, a large amount of the surfactant remains in the purified polyether, which is not preferable.

The amount of water used in the present invention may be from 1 to 50 parts by weight, preferably from 5 to 30 parts by weight, per 100 parts by weight of the high molecular weight polyethers. When the amount of water is less than 1 part by weight, the salt precipitated after dehydration does not become sufficiently large. Therefore, when the amount of water is less than 50 parts by weight, it is not economical because the time and heat required for the dehydration step are large. .

[0036] As a method for removing the salt, Filtration law, Ru with a centrifugal separation method. When salts are removed from high-molecular-weight polyethers, they can be diluted with a solvent, if necessary. Such a method is effective when the molecular weight of the high molecular weight polyether compound is large and, therefore, the viscosity is high. In that case, the solvent that can be used is essential not to dissolve the salt, but is not particularly limited.

Examples of the solvent usable in the present invention include aliphatic hydrocarbon solvents such as hexane, heptane and octane, alicyclic hydrocarbon solvents such as cyclohexane and methylcyclohexane, benzene, toluene and xylene. , Aromatic hydrocarbon solvents such as dichloromethane, trichloroethylene and tetrachloroethylene, and halogenated aromatic hydrocarbon solvents such as chlorobenzene and dichlorobenzene.

In the present invention, a base contained in a high-molecular-weight polyether containing an alkali metal halide to be purified can be neutralized with an acid, which is generally preferable.

[0039] The acids which can be used to neutralize soluble, organic acids, inorganic acids, organic acids salts formed by neutralization in the case of either good and organic acids of the solid acid is in the polyethers of high molecular weight In some cases, inorganic acids and solid acids are preferred.

Examples of the inorganic acid usable in the present invention include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid, perchloric acid and the like. Examples of the solid acid include activated clay, magnesia silicate, aluminosilicate and hydrochloride. An adsorbent and the like also known as a solid ion exchanger such as talcite can be exemplified, but the present invention is not limited thereto.

When the base in the high molecular weight polyether containing an alkali metal halide is neutralized, it is necessary to add a surfactant and water to the high molecular weight polyether containing an alkali metal halide. , At the time of addition.

[0042]

EXAMPLES The present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

[0043] [Reference Example 1] polyoxypropylene triol in the presence of a catalyst a molecular weight of 30,000 to propylene oxide and the obtained by polymerizing, in 1-fold equivalent of NaH and a nitrogen atmosphere at 60 ° C. for the hydroxyl group reacting glycerol as the initiator After making it into sodium alkoxide, 1.05 times equivalent of allyl chloride was added, and after reacting at 60 ° C., unreacted allyl chloride was distilled off under reduced pressure to obtain terminal allyl containing sodium chloride. A polyether compound (hereinafter referred to as unpurified polyether A) was produced.

[0044] [Reference Example 2] After polymerizing the presence of a catalyst of propylene oxide and ethylene glycol as the initiator and a molecular weight of 15,000, under a nitrogen atmosphere to a further polyether diol having a molecular weight of 18000 obtained by polymerizing ethylene oxide, powdered water 1.5 equivalents added to the polyether diol sodium oxide, further methallyl chloride 1.
05 equivalents added and reacted at 60 ° C., the methallyl chloride unreacted was distilled off under reduced pressure, terminal alkenyl polyether compound containing sodium chloride and sodium hydroxide (hereinafter, unpurified polyether B).

REFERENCE EXAMPLE 3 A polyoxo resin having a molecular weight of 4000 obtained by polymerizing propylene oxide in the presence of a catalyst using butanol as an initiator.
Dipropylene mono nitrogen atmosphere ol, relative to the hydroxyl group, sodium metal 1.0 equivalents was added, 3 at 120 ° C.
Allowed to react for hours. Further allyl chloride 1.1 equivalents <br/> Ryokuwae and reacted at 60 ° C., allyl chloride unreacted was distilled off under reduced pressure, terminal alkenyl polyether compound containing sodium chloride (hereinafter , Crude polyether C).

Example 1 100 g of unpurified polyether A was placed in a glass reactor equipped with a stirrer, and 1 g of a polyoxyethylene oxypropylene block copolymer (molecular weight: 10,000, containing 12% by weight of oxyethylene chains) and 1 g of unpurified polyether 1. to basic alkali metal compound contained in a 05 equivalents of H
20 g of a hydrochloric acid aqueous solution containing Cl was added, and the mixture was stirred at 60 ° C for 2 hours. The mixture was heated to 80 ° C. and water was removed by passing nitrogen gas. After adding 100 g of hexane and stirring at room temperature for 30 minutes, the mixture was filtered using a filter paper precoated with celite. The solvent was distilled off under reduced pressure from the filtrate to give a pale yellow oil transparent (polyether Le).

[0047] [Example 2] placed unpurified polyether B1 200 g equipped with a stirrer glass reactor, cetyl alcohol ethylene oxide adduct (manufactured by NOF Corporation, nonionic P-208, polyoxyethylene chain 15 wt% including Yes) 0 . to basic alkali metal compound contained in 2g and unpurified polyether B aqueous hydrochloric acid 10g was added containing HCl of 1.02 equivalents was stirred for 2 hours at 60 ° C.. The mixture was heated to 80 ° C. and water was removed by passing nitrogen gas. After adding 50 g of toluene and stirring at room temperature for 30 minutes, the mixture was filtered using a filter paper precoated with tocopearlite. The solvent was distilled off from the filtrate under reduced pressure,
Pale yellow oil transparent (polyether Le).

Example 3 100 g of unpurified polyether C was put into a glass reactor equipped with a stirrer, and 0.1 g of a polyoxyethylene oxypropylene block copolymer (molecular weight 10,000, containing 12% by weight of oxyethylene chains) and magnesia silicate were used. 0.
5 g and 5 g of water were added, and the mixture was stirred at 60 ° C. for 2 hours. The mixture was warmed to 80 ° C., to remove water through the nitrogen gas. Celite was filtered using a precoated filter paper to give a pale yellow oil transparent (polyether Le).

[0049] [Comparative Example] put crude polyether Le A 100 g equipped with a stirrer glass reactor, basic A contained in the unpurified polyether A
To alkali metal compound aqueous hydrochloric acid 20g was added containing HCl of 1.05 equivalents was stirred for 2 hours at 60 ° C.. The mixture was heated to 80 ° C. and water was removed by passing nitrogen gas. Hexane 100g was added and after stirring 30 minutes at room temperature, was filtered using a filter paper pre-coated with Celite filtration properties significantly worse in comparison with Example 1, was able to filter the total amount. The solvent was distilled off from the filtered solution under reduced pressure to obtain a cloudy oil.

Table 1 summarizes the results of analyzing the purified products obtained in the above examples. (1) in Table 1
The pH value, (2) Cl ^- ion, and (3) Cl ^- removal rate are as follows, respectively.

(1) The p value obtained by dissolving 10 g of polyether in 60 cm ³ of isopropyl alcohol-ion-exchanged water (mixed solvent having a volume ratio of 60/40) adjusted to pH = 7.
H value (2) Chlorine ion amount per 1 g of polyether (mmol / g) determined by titration with an aqueous silver nitrate solution using potassium chromate as an indicator (3) What percentage of chlorine ions contained in unpurified polyether after purification Indicates whether the removal was successful.

[0052]

[Table 1]

[0053]

As shown in the examples, the present invention can provide polyethers having a small amount of chloride ions (that is, a small amount of an alkali metal halide).

Continuation of the front page (56) References JP-A-61-203125 (JP, A) JP-A-54-91594 (JP, A) JP-A-58-168623 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) C08G 65/00-65/48

Claims (6)

(57) [Claims] 1. A surfactant and water are added to a high molecular weight polyether containing a small amount of an alkali metal halide, followed by dehydration, followed by removal of the alkali metal halide.
A method for purifying polyethers, which comprises removing the substance by filtration or centrifugation . 2. A high-molecular-weight polyether containing a small amount of an alkali metal halide can be prepared by converting a high-molecular-weight polyether having a hydroxyl group and a halogenated hydrocarbon into a hydroxyl group in the presence of an alkali metal or a basic alkali metal compound. The purification method according to claim 1, which is a product obtained by subjecting a hydroxyl group of a high-molecular-weight polyether having an alkali metal alkoxide to an alkali metal alkoxide and then reacting the resultant. 3. The method according to claim 2, wherein the halogenated hydrocarbon is an alkenyl halide. 4. A high molecular weight polyether having a hydroxyl group,
The purification method according to claim 2, which is a polyether having 1 to 6 hydroxyl groups and a molecular weight of 1,000 to 50,000. 5. The method according to claim 5, wherein the polyether is a polyoxyalkylene polyol obtained by reacting an alkylene oxide having 3 to 6 carbon atoms with a monovalent to tetravalent initiator in the presence of a catalyst. 6. The purification method according to claim 1, wherein the surfactant is a nonionic surfactant having an oxyethylene chain in a molecule of 5% by weight or more.