CN103524331A - Preparation method of 2,2-dimethylolbutanoicacid - Google Patents

Abstract

The invention provides a synthetic method of 2,2-dimethylolbutanoicacid (DMBA). The synthetic method comprises the following steps of adding formaldehyde and a trimethylamine catalyst into a reaction kettle; adding n-butana, performing thermal reaction, and adjusting the pH to be 7 by using formic acid after reaction; then steaming out redundant formaldehyde and n-butana; heating, adding oxydol for oxidation, and then concentrating water; adding water, concentrating and then adding a diluting agent to perform crystallization so as to obtain a crude product; adding the crude product and a recrystallization solvent into the reaction kettle to perform recrystallization; centrifuging to obtain 2,2-dimethylolbutanoicacid. The preparation method provided by the invention is simple and convenient in operation, has an industrial prospect, reduces the production cost, and effectively avoids the content of metal ions, so that the application range of the product is wider.

Description

A kind of preparation method of 2.2-dimethylolpropionic acid

Technical field

The invention belongs to chemical technology field, be specifically related to a kind of preparation of 2.2-dimethylolpropionic acid

Background technology

The structural formula of 2,2-dimethylolpropionic acid (DMBA):

2.2-dimethylolpropionic acid is a kind of two hydroxyls that have, the new type functional hydrophilic chain extender of the multi-functional group of a carboxyl. as fine-chemical intermediate of new generation, there is lower fusing point and good solubility, replace just gradually first-generation product 2,2-dimethylol propionic acid (DMPA), for aspects such as aqueous polyurethane, water-soluble polyester, sizing agent, finishing agents, is a kind of Green Product.

There is following problem in the synthesis technique of existing 2.2-dimethylolpropionic acid: the one, current suitability for industrialized production be mainly to use mineral alkali (sodium hydroxide, sodium carbonate), or mixture (sodium hydroxide and sodium carbonate), metal ion sodium ions content in product too high (being greater than 50ppm) like this, limited the range of application of product. the 2nd, have at present report research aspect with mineral alkali or ion exchange resin etc., there is Low Response, yield is low, technique more complicated, energy consumption is high, the problems such as environmental pollution. the 3rd, dimethylolpropionic acid last handling process is owing to there being formic acid, unreacted dihydroxymethyl butyraldehyde, butanic acid, and the impurity such as polymkeric substance, cause product not easily separated.

Summary of the invention:

Main purpose of the present invention is the preparation method that a kind of 2.2-dimethylolpropionic acid will be provided, its sodium ion (being less than 30ppm) that can effectively reduce in product, make it for electronic industry product aspect, expand its range of application. the 2nd, can increase the yield of product, enable industrialization. the 3rd, can isolate easily and effectively product

Above-mentioned goal of the invention is achieved through the following technical solutions: a kind of preparation method of 2.2-dimethylolpropionic acid: comprise the following steps]:

(1) in reactor or glass four-hole reaction flask, drop into formalin and paraformaldehyde, Trimethylamine 99 catalyzer,

(2) start stirring, drip butyraldehyde-n, dropwise 20-60 degree insulation reaction 6-12h

(3) reaction finishes in the rear formic acid water with reclaiming and after system PH=7, and concentrating under reduced pressure is removed unreacted butyraldehyde-n and formaldehyde,

(4) be warming up to 50 degree and drip hydrogen peroxide, temperature control 50-80 degree, dropwises and carries out the isothermal reaction of 60-80 degree, and then condensed water after reaction adds reconcentration after water 1 volume water,

(5) after concentrated, add thinner, crystallization, suction filtration or centrifugal crude product,

(6) crude product is done recrystallization exquisiteness and is obtained fine work, dries and obtains product.

The preparation method of above-mentioned a kind of 2.2-dimethylolpropionic acid, one of its method is to use to such an extent that material and their ratio are:

(1) 37% formalin and the ratio of paraformaldehyde 100: 0-100: 100.

The ratio 1 of formaldehyde and Trimethylamine 99 catalyzer: 0.04-1: 0.1.

(2) ratio 2 of formaldehyde and butyraldehyde-n: 1-2.5: 1

(3) hydrogen peroxide (30%): butyraldehyde=1: 1-1.2: 1

(4) thinner after concentrated, comprises methylene dichloride, tetrahydrofuran (THF), and ether, methyl tertiary butyl ether, ethyl acetate, isopropyl acetate, methyl alcohol, ethanol, or their mixture, the ratio of usage quantity and butyraldehyde is 2: 1-6: 1

(6) recrystallization solvent is ethanol and ethyl acetate, the ratio of usage quantity and butyraldehyde: 2: 1-6: 1

The effect that the present invention produces is as follows:

The one, by avoiding using inorganic base catalyst, change organic alkali catalyst into, effectively reduced the content of metal ion neutralization product sodium ion, make it to be less than 30PPM.

The 2nd,, through underpressure distillation, remove unreacted butyraldehyde-n and formaldehyde, effectively reduced the generation of side reaction and the solubleness of product, make the easier crystallize out of product

The 3rd, the system after oxidation contains impurity, and product is not easy crystallize out, and our manipulated variable adds appropriate suitable solvent, and impurity is dissolved, and product is separated out, and impurity has obtained effective separated with product.Use to such an extent that solvent is low boiling point solvent simultaneously, can be by air distillation recovery, reduction raw materials cost.

The 4th, by the exquisite product of selective solvent, can once obtain qualified product, avoided repeatedly exquisite product, simplified operation, reduced the generation of waste water.

Accompanying drawing explanation:

Figure of description is process flow sheet: a kind of preparation method's of 2.2-dimethylolpropionic acid process flow sheet.

Following embodiment is to further illustrate of the present invention, but the present invention is not limited thereto:

Embodiment mono-:

(1) at reaction bottle, add 37% formaldehyde 145g, add Trimethylamine 99 10g,

(2) start stirring, drip butyraldehyde-n 54g, add 20 degree to 60 degree insulation reaction 8h

(3) formic acid regulates after PH=7, concentrating under reduced pressure

(4) after concentrated, be warming up to 50 degree, start to drip 100g hydrogen peroxide, add 60-80 degree insulation reaction 12h

(5) after concentrating under reduced pressure, then add 54g water, be again concentrated into anhydrous

(6) add 108g methylene dichloride, crystallization

(7) suction filtration, mother liquor normal pressure reclaims methylene dichloride

(8) refining, by crude product: mixture=1 of ethanol and ethyl acetate: the complete molten rear cooling crystallization of 4 reflux, suction filtration, dries and obtain fine work.Mother liquor normal pressure recovery, the cooling secondary recovery product of raffinate.

Embodiment bis-:

(1) at reaction bottle, add 37% formaldehyde 72.5g, paraformaldehyde 27g, adds Trimethylamine 99 10g,

(2) start stirring, drip butyraldehyde-n 54g, add 20 degree-60 degree insulation reaction 8h

(3) formic acid regulates after PH=7, concentrating under reduced pressure

(4) after concentrated, be warming up to 50 degree, start to drip 100g hydrogen peroxide, add 60-80 degree insulation reaction 1h

(5) after concentrating under reduced pressure, then add 54g water, be again concentrated into anhydrous

(6) add 108g methylene dichloride, crystallization

(7) suction filtration, mother liquor normal pressure reclaims methylene dichloride

(8) refining, by crude product: mixture=1 of ethanol and ethyl acetate: the complete molten rear cooling crystallization of 4 reflux, suction filtration, dries and obtain fine work.Mother liquor normal pressure recovery, the cooling secondary recovery product of raffinate.

In reality, the present invention is simple and practical, and has industrial prospect, reduced production cost, effectively avoided the content of metal ion, makes the range of application of product more extensive.

Claims (2)

1. the preparation method of a 2.2-dimethylolpropionic acid

1. comprise the following steps:

(1), in reactor or glass four-hole reaction flask, drop into formalin and paraformaldehyde, Trimethylamine 99 catalyzer.

(2) start stirring, drip butyraldehyde-n, dropwise 20-60 degree insulation reaction 6-12h.

(3) reaction finishes rear using in restored acid water and after system PH=7, and concentrating under reduced pressure is removed unreacted butyraldehyde-n and formaldehyde.

(4) be warming up to 50 degree and drip hydrogen peroxide, temperature control 50-80 degree, dropwises and carries out the isothermal reaction of 60-80 degree, and then condensed water after reaction adds reconcentration after 1 volume water.

(5) after concentrated, add thinner, crystallisation by cooling, suction filtration or centrifugal crude product.

(6) crude product is done recrystallization exquisiteness and is obtained fine work, dries and obtains product.

2. according to the preparation method of a kind of 2.2-dimethylolpropionic acid of claim 1 narration, it is characterized in that material and their ratio used are:

(1) 37% formalin and the ratio of paraformaldehyde 100: 0-100: 100; The ratio 1 of formaldehyde and Trimethylamine 99 catalyzer: 0.04-1: 0.1

(2) ratio 2 of formaldehyde and butyraldehyde-n: 1-2.5: 1

(3) hydrogen peroxide (30%): butyraldehyde=1: 1-1.2: 1

(4) thinner after concentrated, comprises methylene dichloride, tetrahydrofuran (THF), and ether, methyl tertiary butyl ether, ethyl acetate, isopropyl acetate, methyl alcohol, ethanol, or their mixture, the ratio of usage quantity and butyraldehyde is 2: 1-6: 1

(6) recrystallization solvent is the mixture of ethanol and ethyl acetate, the ratio of usage quantity and butyraldehyde: 2: 1-6: 1.

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