Methyl glycol

Structural formula
General
Surname	Methyl glycol
other names	Ethanediol monomethyl ether; 2-methoxyethanol; Glycol monomethyl ether; Methylcellosolve; 1-methoxy-2-hydroxyethane; Methyl glycol; EGME; METHOXYETHANOL ( INCI ) ;
Molecular formula	C 3 H 8 O 2
Brief description	colorless liquid with an ethereal odor
External identifiers / databases
EC number	203-713-7
ECHA InfoCard	100.003.377
PubChem	8019
ChemSpider	7728
DrugBank	DB02806
Wikidata	Q903362
properties
Molar mass	76.10 g mol −1
Physical state	liquid
density	0.97 g cm −3
Melting point	−86 ° C
boiling point	124 ° C
Vapor pressure	12 h Pa (20 ° C); 21 hPa (30 ° C); 60 hPa (50 ° C);
pK s value	14.8 (25 ° C)
solubility	miscible with water
Refractive index	1.4024 (20 ° C)
safety instructions
H and P phrases	H: 226-360FD-332-312-302
	P: 201-302 + 352-308 + 313-210
Authorization procedure under REACH	of particular concern : toxic for reproduction ( CMR )
MAK	DFG / Switzerland: 1 ml m −3 or 3.2 mg m −3
Toxicological data	2370 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Methyl glycol ( ethylene glycol monomethyl ether ( EGMM ), 2-methoxyethanol ) is a colorless, pleasant-smelling liquid from the group of glycol ethers that was used as a solvent for varnishes , paints and resins .

Extraction and presentation

It is formed in large quantities as a by-product in the manufacture of hydroxyethylmethyl cellulose (HEMC), which is made from alkalized cellulose with ethylene oxide and methyl chloride in a “one-pot reaction”.

properties

Physical Properties

Ethylene glycol monomethyl ether is a flammable, air-sensitive colorless liquid with a pleasant odor. The boiling point is 124 ° C at normal pressure . According to Antoine, the vapor pressure function results from log ₁₀ (P) = A− (B / (T + C)) (P in bar, T in K) with A = 5.06386, B = 1853.556 and C = −30.838 in the temperature range from 329 to 396 K. The compound is miscible with water in any ratio. It forms a constant boiling at 99.9 ° C and 84.7% water azeotrope . With 75% toluene, an azeotrope that boils constantly at 105.9 ° C. is obtained.

Chemical properties

Glycol monoalkyl ethers are inert towards light metals such as aluminum or magnesium. However, slow superficial corrosion can be observed at the boiling point.

Safety-related parameters

Ethylene glycol monomethyl ether forms flammable vapor-air mixtures. The compound has a flash point of 39 ° C. The explosion range is between 2.5% by volume (80 g / m ³ ) as the lower explosion limit (LEL) and 20% by volume (630 g / m ³ ) as the upper explosion limit (UEL). The lower explosion point is 35 ° C. The limit gap width was determined to be 0.81 mm. This results in an assignment to explosion group IIB. The ignition temperature is 285 ° C. The substance therefore falls into temperature class T3.

use

Until the 1980s, ethylene glycol monomethyl ether was used as a solvent for lacquers and paints, as a solvent in the manufacture of printed circuit boards and for dyeing leather. It was found in industrial paint cleaners and cleaning agents for surfaces and was used to manufacture oven-drying industrial paints. It has been replaced industrially by other similar solvents, e.g. B. by methoxypropanol .

safety instructions

Methyl glycol has a toxic effect on the germinal epithelium of the testicle and the embryonic and fetal tissues in the uterus . Methyl glycol thus has a teratogenic effect.

After the teratogenic effects of this substance became known, a substitution process took place, which led to the fact that this solvent is no longer used for coatings in consumer products and only in small quantities in industrial coatings.

Individual evidence

↑ Entry on METHOXYETHANOL in the CosIng database of the EU Commission, accessed on April 16, 2020.
↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t Entry on ethylene glycol monomethyl ether in the GESTIS substance database of the IFA , accessed on October 6, 2017(JavaScript required) .
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Dissociation Constants of Organic Acids and Bases, pp. 8-43.
↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-330.
↑ Entry on 2-methoxyethanol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Entry in the SVHC list of the European Chemicals Agency , accessed on October 18, 2015.
↑ Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 109-86-4 or methylglycol ), accessed on November 2, 2015.
↑ J. Pick, V. Fried, E. Hala, O. Vilim: The vapor pressure of ethylene glycol monomethyl ether and of ethylene glycol monoethyl ether. In: Collect. Czech. Chem. Commun. 21, 1956, pp. 260-261, doi: 10.1135 / cccc19560260 .
↑ Database for azeotropes, composition in mol%
↑ C. Yoshimura, T. Ogura In: Keikinzoku. 32, 1982, pp. 443-450. it is unclear whether atmospheric oxygen was excluded. Addition of water suppressed the aluminum corrosion, accelerated the magnesium corrosion. (Journal of Japan Institute of Light Metals).
↑ ^a ^b ^c ^d E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.
↑ BASF - Solvent overview .

[CosIng-1] Entry on METHOXYETHANOL in the CosIng database of the EU Commission, accessed on April 16, 2020.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l ^m ⁿ ^o ^p ^q ^r ^s ^t Entry on ethylene glycol monomethyl ether in the GESTIS substance database of the IFA , accessed on October 6, 2017(JavaScript required) .

[CRC90_8_43-3] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Dissociation Constants of Organic Acids and Bases, pp. 8-43.

[CRC90_3_330-4] David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-330.

[CLP_100.003.377-5] Entry on 2-methoxyethanol in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[SVHC-6] Entry in the SVHC list of the European Chemicals Agency , accessed on October 18, 2015.

[7] Swiss Accident Insurance Fund (Suva): Limit values - current MAK and BAT values (search for 109-86-4 or methylglycol ), accessed on November 2, 2015.

[8] J. Pick, V. Fried, E. Hala, O. Vilim: The vapor pressure of ethylene glycol monomethyl ether and of ethylene glycol monoethyl ether. In: Collect. Czech. Chem. Commun. 21, 1956, pp. 260-261, doi: 10.1135 / cccc19560260 .

[9] Database for azeotropes, composition in mol%

[10] C. Yoshimura, T. Ogura In: Keikinzoku. 32, 1982, pp. 443-450. it is unclear whether atmospheric oxygen was excluded. Addition of water suppressed the aluminum corrosion, accelerated the magnesium corrosion. (Journal of Japan Institute of Light Metals).

[Brandes-11] E. Brandes, W. Möller: Safety-related parameters. Volume 1: Flammable Liquids and Gases. Wirtschaftsverlag NW - Verlag für neue Wissenschaft GmbH, Bremerhaven 2003.

[12] BASF - Solvent overview .