DIPN

Diisopropylnaphthalenes ( DIPN ) are chemical compounds from the group of naphthalenes. They include the isomers 1,2 -, 1,3 -, 1,4 -, 1,5 -, 1,6 -, 1,7 -, 1,8 -, 2,3 -, 2,6 - and 2,7- diisopropyl naphthalene. The technical product, which represents a mixture of isomers, are primarily 1,3 -, 1,4 -, 1,5 -, 1,6 -, 1,7 -, 2,6 - and 2,7- diisopropylnaphthalene include, where 2, 6 - and 2,7 - diisopropyl make up as the preferred isomers, each with about 40% of the main part.

Production and representation

Diisopropylnaphthalingemische are mainly produced from naphthalene or by alkylation or transalkylation reactions monoisopropylnaphthalene. In a production variant naphthalene is reacted with propyne in a fixed bed reactor over a Alumosilikatkatalysator at temperatures between 160 ° C and 250 ° C. The composition of the resulting mixtures of isomers can be influenced by the temperature. Separation of the isomers can be effected by a combination of distillation and crystallization steps.

Properties

Diisopropylnaphthalene as a technical product is a colorless and odorless liquid. 1,3 - and 2,6- diisopropyl naphthalene are colorless solid.

• Bis ( isopropyl) naphthalene
• Di (1- methylethyl) -naphthalene
• DIPN

Use

Diisopropylnaphthalene is used as a substitute for polychlorinated biphenyls, and as a solvent for dyes in carbonless papers. In Japan and Germany alone, 10,000 tons of DIPN isomer are produced annually. The DIPN causes problems in the recycling of waste paper, if this is then used as a packaging material in the food industry, since it is not removed during the recycling process and can be transferred to the food in the absence of additional packaging. Currently ( as of 2001), although no specific health concerns to DIPN are known, but should, according to the Federal Institute for Consumer Health Protection and Veterinary Medicine in pursuing the general minimization principle, the content of DIPN be kept as low as is technically possible. Toxicologically are the DIPN According to a study by the Federal Institute for Risk Assessment (2011 ) harmless because the alkyl substitution of the aromatic ring prevents ring oxidation and thus the conversion to toxic reaction products. 2,6- DIPN is functionally and structurally identical to naturally occurring plant growth regulators in potato and is therefore used as a germ- stop means for potatoes.