DD158479A3 - METHOD FOR CONTINUOUS PRODUCTION OF EPOXY RESINS - Google Patents

Abstract

The invention relates to a process for the continuous production of epoxy resins. The preparation of epoxy resins having an epoxide equivalent weight between 180 and 1100 and a content of 75 to 85% by weight of diglycidyl ethers by reaction of epichlorohydrin, 2,2-bis (4-hydroxyphenyl) propane (Dian), alkali metal hydroxide and water is carried out in d. Way that d. Reaction components continuously in a reactor in a rotating, turbulent motion with a rotational speed v. 8 to 12 m / s combined u. at a residence time v. 1 to 1.5 See be implemented together. D. Reaction is then in 2 or 3 other reactors at d. each same residence time continued. D. temperature d. exothermic reaction is initially between 313 u. 383 degrees K u. reaches 383 to 444 degrees K. During d. Reaction can be added to a solvent. With d. Process, a high space-time yield is achieved in a small footprint of the plant, with a high degree of conversion, recognizable by the relatively high Diglycidylaethergehalt achieved.

Description

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VEB Leuna-Werke ~ Leuna, 23 »3« 81

!"Walter Ulbricht!!

L? 80125

Title of the invention

Process for the continuous production of epoxy resins

Field of application of the invention

The invention relates to a process for the continuous production of epoxide resins from epichlorohydrin, 2,2-bis (4-hydroxyphenyl) propane and aqueous alkali metal hydroxide.

Characteristic of the known technical solutions

For the production of epoxy resins, in which epichlorohydrin, 2,2-bis - (^ hydroxyphenyl) propane and aqueous sodium hydroxide solution are brought to Rea »different continuous processes are known in the US-PS 2,840,541 a method is described The reaction time is very long in this process, so that only a small space-time yield is achieved. "With the use of agitated cascades, a multiplicity of organic by-products 9, which are of the epoxy resin quality, also occur · Worsen

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In order to avoid these disadvantages, US Pat. No. 2,986,551 describes a stirred-tank cascade with 6 reactors and acetone as a solubilizer. The residence time is 3 to 15 minutes per reactor, there is a gradual addition of sodium hydroxide »

The use of alcohols as solubilizers is described in US Pat. No. 2,848,435. "The residence time is 2 hours." The disadvantage of these processes is, above all, the low space-time yield. "

In DD-PS 137 805 a continuous process for the preparation of epoxy resins with 1 or 2 reactors, a residence time of a maximum of 5 or 10 see, a speed of 15 to 50 m * sec and a temperature of 60 to 18O ⁰ G is described A disadvantage of this process is the high content of phenolic hydroxyl-containing monoglycidyl compounds of 6 to 10% by mass and saponification products of the diglycidyl ethers of 12 to 18% by mass in the epoxy resin. This composition of the epoxy resin degrades the utility properties and adversely affects the specific consumption of the starting materials.

Object of the invention

The aim of the invention is to continuously produce epoxy resins with a high content of diglycidyl ethers with a low specific material consumption and an extremely high space-time yield.

Explanation of the essence of the invention

The invention is based on the object, a process for the continuous production of epoxy resins with an epoxide equivalent between 180 and 1100 and a content of 78 to 85 percent by weight of Diglycidylaethern by reaction of Spichlorhydrin, 2,2-bis (4-hydroxyphenyl) propane This object is achieved by galozing that the reaction components are continuously rotating in a reactor,

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turbulent motion at a rotational speed of 8 to 12 m / sec combined and reacted at a temperature of 313 to 383 K and a residence time of 1 to 1 ₅ 5 see that the reaction in a second reactor at 343 to 403 K and in a third reactor at 363 to 423 K and optionally in a fourth reactor at 383 to 443 K, in each case at a rotational speed of 8 to 12 m / sec and at a residence time of 1 to 1.5 see continued ·

The content of epoxy resin in phenolic hydroxyl-containing monoglycidyl compounds is between 2 and 3% by mass and the content of saponification product at the diglycidyl ether is between 5 and 8% by mass. Optionally, a solvent may be added to the fourth reactor. Solvents are toluene, xylene or methyl isobutyl ketone Mixtures of these substances.

Working Examples: Example 1

A mixture of 40% by mass of 2,2-bis (4-hydroxyphenyl) propane, 6% by mass of sodium hydroxide and 54% by mass of water is metered continuously into a reactor. At the same time, bichlorohydrin and a mixture of 48% by mass of sodium hydroxide and 52% by mass of water become continuous The molar ratio of epichlorohydrin to 2,2-bis- (4-hydroxyphenyl) -propane is 1.8: 1. In the reactor, a rotational speed of 3, 2 m / sec is imposed on the reactor mixture by means of rotating device components high turbulence and thus large phase boundary areas * The reaction products react at a temperature of 353 K and at a flow rate of 9 _S 2 m * sec with a residence time of 1.3 sec. "The reactor leaving the reactor

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Mixture is completely reacted in a second reactor at the same speed and residence time and at 376 K, in a third reactor at the same residence time and speed and at 405 K and in a fourth reactor at the same residence time and speed and at 436 K.

The reaction mixture leaving the fourth reactor is worked up in a manner known per se. The epoxy resin has the following properties:

Epoxy equivalent 320

Diglycidyl ether (mass%) 80.2 phenolic Eydroxy! Groups containing

Monoglycidy compounds (% by mass) 2.5 saponification prodrugs of diglycidyl ethers

(% By mass) 7.8

The quantitative analytical detection of the diglycidyl ethers, the monoglycidyl phenolic compounds and the saponification products of the diglycidyl ethers was carried out by high performance liquid chromatography with gradient elution. The separation column used was Lichrosorb RP 8 10 g / l and the eluent acetonitrile / acid.

Example 2

A GemisGh of 40 weight percent 2,2-bis (4-hydroxyphenyl) propane, 6 weight percent sodium hydroxide and 54 weight percent water is continuously metered into the first reactor. Simultaneously, epichlorohydrin and a mixture of 20 weight percent sodium hydroxide and 80 weight percent water are continuously injected » The ratio of epichlorohydrin to 2,2-bis- (4-hydroxyphenyl) -propane is 1.6: 1, in the reactor, the starting materials react at a temperature of 363 K and at a flow rate 10, -8 m ^a see "at a Residence time of 1.4 see · Das

The reactor leaving the reaction mixture is in a second reactor at the same speed and residence time and at 384 K, in a third reactor at the same Ge

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speed and residence time at 415 K and in a fourth reactor at the same speed and residence time as well as at 427 K are completely implemented ·

The reaction mixture leaving the fourth reactor is worked up in a known manner. The epoxy resin has the following properties!

Epoxy equivalent 405 Diglycidyl ether (mass%) 82.4

containing phenolic hydroxyl groups

Monoglycidic compounds (mass%) 2.9

Saponification products of diglycidyl ethers

(% By mass) 7 »2

Example 3 -

A mixture of 50 weight percent 2,2-bis (4-hydroxyphenyl) propane, 7 weight percent sodium hydroxide and 43 weight percent water is metered continuously into the first reactor. At the same time, epichlorohydrin and a mixture of 48% by mass of sodium hydroxide and 52% by mass of water are continuously injected. The molar ratio of epichlorohydrin to 2,2-bis- (4-hydroxyphenyl) -propane is 1.4: 1. In the reactor, the starting materials react with a temperature -. door of 374 K and a speed of 11.3 m · see with a residence time of 1.2 see. The reaction mixture leaving the reactor is completely reacted in a second reactor at the same speed and residence time and at 393 K, in a third reactor at the same speed and residence time and 409 K and in a fourth reactor at the same speed and residence time and at 421 K. The reaction mixture leaving the fourth reactor is worked up in a known manner. The epoxy resin has the following properties:

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Epoxide equivalent 540

Diglycidyl ether (mass%) 84.1

containing phenolic hydroxyl groups

Monoglycidyl compounds (mass%) 2.6

Saponification products of diglycidyl ethers

(Mass%) 6.4

Example 4

A mixture of 40% by weight of 2,2-bis (4-hydroxyphenyl) propane, 6% by weight of sodium hydroxide and 54% by mass of water is metered continuously into the first reactor. At the same time, spichlorohydrin and a mixture of mass percent sodium hydroxide and 52% by mass water are continuously injected. The molar ratio of epichlorohydrin to 2,2-bis- (4-hydroxyphenyl) -propane is 1.3 ί1 · In the first reactor, the starting materials react at a temperature of 340 K and a velocity of 8.5 nm · sec at one Residence time of 1.5 see. The reactor leaving the reaction mixture is in a second reactor at the same speed and residence time and at 364 K, in a third reactor at the same speed and residence time and at 401 K and in a fourth reactor with simultaneous injection of 65 weight percent methyl isobutyl ketone, based on 35 Percent by mass of the resulting epoxy resin, completely reacted and dissolved at 408 K.

The reaction mixture leaving the fourth reactor is worked up in a known manner. The epoxy resin has the following properties:

Epoxy equivalent 96Ο

Diglycidyl ether (mass%) 78.5

containing phenolic hydroxyl groups

Monoglycidyl compounds (% by mass) 2.1

Saponification products of diglycidyl ethers

(% By mass) 5.3

Claims (3)

-τ- 228744 O invention claim o Process for the continuous production of epoxy resins having an epoxide equivalent between 180 and 1100 and a content of 75 to 85 percent by weight of diglycidyl ethers by reaction of epichlorohydrin, 2,2-bis (4-hydroxyphenyl) propane, alkali metal hydroxide and water, if necessary Presence of solvents, characterized in that the reaction components continuously in a reactor in a rotating, turbulent motion at a rotational speed of 8 to 12 m / seo zusammenue'hu and at a temperature of 313 to 383 K and with a residence time of 1 to 1 _? 5 See that the reaction in a second reactor at 343 to 403 K and in a third reactor at 36 3 to 423 K and optionally in a fourth reactor at 383 to 443 K ₉ each at a rotational speed of 8 to 12 m / sec and at a residence time of 1 to 1.5 see, is continued. 2. The method according to item 1, characterized in that a solvent in the. fourth reactor is dosed » 3 · Process according to item 1 and 2, characterized in that as solvent toluene, Sylol ,. Methyl isobutyl ketone or mixtures of these substances are used *