CS269089B1 - A method of preparing an accelerating placentifier - Google Patents

Abstract

A method for preparing an accelerating plasticizer for epoxy resins cured with aliphatic polyamines, which consists in heating 1-naphthol with allyl chloride and potassium or sodium hydroxide in a molar ratio of 1:1 to 3:1 to 1.6 in an aqueous alkaline medium at the boiling point of the reaction mixture for 4 to 8 hours, preferably extracting the reaction mixture with a solution of potassium or sodium hydroxide after the reaction is complete. The organic phase is removed from the reaction mixture and the volatile components are removed by distillation to a temperature of 145 C at a pressure of 3.33 kPa for 3/4 hours.

Description

The present invention relates to a process for the preparation of an accelerating plasticizer for epoxy resins cured by aliphatic polyamines.

For successful curing of epoxy resins with aliphatic polyamines, it is recommended to work at a minimum temperature of 18 ° C ». Curing accelerators must be used at lower temperatures ·· Each curing accelerator is necessarily intoxicated by shortening the pot life. , phenols, acids or water · However, they usually have too low boiling points and therefore cannot be used in larger quantities or have a higher molecular weight, but then they are solid and must be dissolved for dosing, for example bisphenol A. A practically usable accelerator should have effectiveness also good processability, dosability, compatibility with resins and does not have an adverse effect on the properties of cured materials. Common accelerators for curing with aliphatic polyamines at room temperature are salicylic acid and benzoic acid, triethanolamine and cresol · Phenols They are effective even at +5 ° C, alcohols no longer · Biaphenol A is also effective, but must be dissolved in a suitable solvent before use · Cresol it has an unpleasant odor and washes out water with water. Higher alkylphenols are better in this, but they are less effective and more should be used. This can be used when the accelerator has a plasticizing effect, as the mechanical properties of the accelerator do not deteriorate sharply · The efficiency of the accelerator increases with the acidity of the phenolic hydroxyl group condensates of sniline with formaldehyde, urea derivatives, piperazine, triphenylamine, etc.

It has now been found that by reacting 1-naphthol and alkyl chloride and potassium or sodium hydroxide in molar ratios of 1: 1 to 3: 1 to 1.6 in an aqueous-alcoholic medium at the boiling point of the reaction mixture for 4 to 8 hours, optionally by extraction A solution of potassium or sodium hydroxide and distillation of the product at 145 DEG C. under a pressure of 3.33 KPa for 3/4 hours can be used to obtain an effective accelerating plaqueifier directly from the reaction mixture without having to prepare the individual components separately and then mix in the desired ratio.

The accelerating plasticizer is produced from 1-naphthol of common grade, then from alkyl chloride also of common grade · The auxiliary raw materials are technical ethyl alcohol and potassium hydroxide / sodium hydroxide / · These are mixed according to the selected molar ratios and refluxed for the required time. The mixture is processed according to the extent to which 1-naphthol is to be removed. the product, after separation from the inorganic phase, is distilled for 1 hour at 140 [deg.] C. at 3.33 kPa. The product forms a dark red clear odorless liquid. In the range of 1-naphthol: allyl chloride molar ratios 1: 1.3 to 2.6 and reaction times of 4 to 8 hours, for example, three types of accelerating plasticizer can be obtained, the approximate compositions of which are given in the following table:

Type AND B C 1 - naphthol % by weight · 30 10 1 1 - naphthyl allyl ether 40 60 89 4-allyl-1-naphthol 20 20 6 2-allyl-1-naphthol W 10 10 4 viscosity at 25 ° C Bye. with 0.036 0.025 0.018

CS 269 089 Bl

In the same manner, an accelerating flame retardant can be prepared from 2-naphthol.

Example 1

A mixture of 144 g of 1-naphthol, 150 ml of ethyl alcohol, 115 g of allyl chloride, 200 ml of water and 60 g of potassium hydroxide is refluxed for 5 hours. 3.33 kPa. On cooling, the residue precipitates unreacted 1-naphthol from the crude product. After suction filtration on a frit, 150 g of a dark red product with a viscosity of 0.036 Pa.s / 25 DEG C. are obtained.

A mixture of 144 g of 1-naphthol, 150 ml of ethyl alcohol, 153 g of allyl chloride, 250 ml of water and 90 g of potassium hydroxide was refluxed for 4 hours. Stir for 15 minutes · After separation of the ee from the upper organic phase, the volatiles are removed by distillation in vacuo to 145 ° C at a pressure of 3.33 kPe for 3/4 hour · 124 g of a dark red product with a viscosity of 0.025 Pa * s are obtained / 25 ° C ·

Example 3.

SmSs 144 g of 1-naphthol, 150 ml of ethyl alcohol, 191 g of allyl chloride, 250 ml of water and 52 g of eodium hydroxide are refluxed for 8 hours. To the cooled reaction mixture 30 g of potassium hydroxide, 70 ml of benzene are added After washing the reaction mixture according to Example 2, 112 g of a dark red product with a viscosity of 0.018 Pe.s / 25 ° C are obtained.

Claims (1)

OBJECT OF THE INVENTION Process for the preparation of an accelerating plasticizer for epoxy resins cured with aliphatic polyamines, characterized in that ee heats 1-naphthol with allyl chloride and delletal hydroxide or iodine hydroxide in molar ratios of 1 ι 1 to 3: 1 to 1.6 in an aqueous alkaline medium at the temperature of the reaction fluid for 4 to 8 hours, preferably extracting the reaction mixture with potassium or sodium hydroxide solution after the reaction, the organic phase is separated from the reaction mixture and the volatiles are removed by distillation to 145 ° C at a pressure of 3.33 Pe for 3 hours. /4 o'clock· .