Oxypropylene group-containing glycol ether production method including allyl group-containing impurity isomerization step

Abstract

[Problem] To easily produce an oxypropylene group-containing glycol ether that substantially contains no allyl group-containing impurity and does not adversely affect a polymerization reaction of a polyether-polysiloxane block copolymer when used as a reaction solvent or a diluent, by easily separating the oxypropylene group-containing glycol ether by distillation or the like in a facility and a reaction process that are industrially relatively easy and simple. [Solution] An oxypropylene group-containing glycol ether production method which includes a step for isomerizing an allyl group-containing impurity contained in an oxypropylene group-containing glycol ether by using a ruthenium carbene complex that is known as a Grubbs catalyst, and preferably further includes a purification step for separating the oxypropylene group-containing glycol ether by using a means such as distillation.

Claims

1. A method for producing oxypropylene group-containing glycol ethers, comprising the step of isomerizing allyl group-containing impurities contained in oxypropylene group-containing glycol ethers in the presence of a ruthenium carbene complex, wherein the terminal hydrogens are substituted with hydrocarbon groups having 1 to 8 carbon atoms, and the other terminals have alcoholic hydroxyl groups, the number of repeating oxyalkylene units having 2 to 4 carbon atoms is in the range of 1 to 3, and the glycol ethers do not contain heteroatoms other than oxygen.

2. The method for producing oxypropylene group-containing glycol ethers according to claim 1, characterized in that, by the isomerization reaction described above, the allyl groups in the allyl group-containing impurities are converted to propenyl groups, and the composition after the isomerization reaction is substantially free of allyl group-containing impurities.

3. The method for producing oxypropylene group-containing glycol ethers according to claim 1, further comprising a purification step of separating the oxypropylene group-containing glycol ethers from the ruthenium carbene complex after the isomerization reaction step.

4. The method for producing oxypropylene group-containing glycol ethers according to claim 3, characterized in that the purification step includes a distillation step of oxypropylene group-containing glycol ethers.

5. The method for producing oxypropylene group-containing glycol ethers according to claim 1, wherein the ruthenium carbene complex used in the isomerization reaction step is one or more selected from a first-generation Grubbs catalyst having a ruthenium metal core, a benzylidene carbene ligand, and two tricyclohexylphosphine ligands, and a second-generation Grubbs catalyst having a ruthenium metal core, a benzylidene carbene ligand, a tricyclohexylphosphine ligand, and an N-heterocyclic carbene ligand.

6. A method for producing oxypropylene group-containing glycol ethers according to claim 1, characterized in that the molar ratio of residual allyl groups to oxypropylene groups is 1 / 5000 (0.02 mol%) or less.

7. A method for producing oxypropylene group-containing glycol ethers according to claim 1, comprising the step of isomerizing an allyl group-containing impurity in the presence of a ruthenium carbene complex, and then treating it with one or more acidic inorganic salts characterized by being solid at 25°C, being water-soluble, and having a pH of 4 or less at 25°C when 50 g is dissolved in 1 L of deionized water.

8. The method for producing oxypropylene group-containing glycol ethers according to claim 1, wherein the oxypropylene group-containing glycol ethers are one or more glycol ethers selected from propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, and tripropylene glycol monoethyl ether.

9. The method for producing oxypropylene group-containing glycol ethers according to claim 1, further comprising the step of adding 1 ppm to 1% by mass of an antioxidant to the oxypropylene group-containing glycol ethers at any time.

10. A method for producing a polyether-polysiloxane block copolymer composition, characterized in that the oxypropylene group-containing glycol ethers obtained by the method for producing oxypropylene group-containing glycol ethers according to any one of claims 1 to 9 are used as a reaction solvent or diluent.

11. A method for producing a polyurethane foam-forming composition, characterized in that the oxypropylene group-containing glycol ethers obtained by the method for producing oxypropylene group-containing glycol ethers according to any one of claims 1 to 9 are used as a reaction solvent or diluent for a polyether-polysiloxane block copolymer.

12. A glycol ether containing one or more oxypropylene groups selected from propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monopropyl ether, propylene glycol monoethyl ether, dipropylene glycol monoethyl ether, and tripropylene glycol monoethyl ether, or a mixture thereof, wherein the molar ratio of residual allyl groups to oxypropylene groups is 1 / 5000 (0.02 mol%) or less, and which is substantially free of allyl group-containing impurities, and optionally contains 1 ppm to 1% of an antioxidant.

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