CS241391B1 - A method for producing mixed heat resistant aminoplasts - Google Patents

Abstract

A method for producing mixed heat-resistant modified aminoplasts by condensing a mixture of melamine and urea with formaldehyde at a temperature of 60 to 150 °C in a single operation in a suspension in the presence of fillers, dyes, catalysts and lubricants. The essence of the invention lies in the fact that the condensation is carried out in the presence of 5 to 80% by weight of modifiers, which are 6-caprolactam and/or ε-aminocarboxylic acids, based on the total weight of melamine and urea.

Description

Method for producing mixed heat-resistant modified aminoplasts by condensing a mixture of melamine and urea with formaldehyde at a temperature of 60 to 150 °C in a single operation in a suspension in the presence of fillers, dyes, catalysts and lubricants.

The essence of the invention lies in the fact that the condensation is carried out in the presence of 5 to 80% by weight of modifiers, which are 6-caprolactam and/or ε-aminocarboxylic acids, based on the total weight of melamine and urea.

The invention relates to a method for producing mixed heat-resistant modified aminoplasts with increased heat resistance in a single operation in a floating state.

Mixed aminoplasts belong to the category of thermosetting molding compounds. The melamine component is partially replaced by urea in order to reduce the production cost of aminoplasts.

The disadvantage of these aminoplasts is the impossibility of their processing by progressive technology, i.e. by injection molding, and the reduction of physical-mechanical and electrical properties. At the same time, they show permanent heat resistance only below 150 °C. The methods known so far for the production of mixed aminoplasts work on the principle of preparing pure resin or its solution, which is then mixed with the fillers used. The production operation takes at least 2 hours.

The above disadvantages are eliminated by the method of producing heat-resistant modified aminoplasts by condensing a mixture of melamine and urea with formaldehyde at a temperature of 60 °C to 150 °C in a single operation in the presence of fillers, dyes, catalysts and lubricants, which is the subject of the invention, the essence of which lies in the fact that the condensation is carried out in the presence of 5 to 80% by weight of modifiers, which are 6-caprolactam and/or ε-aminocarboxylic acids, based on the total weight of melamine and urea.

The advantage of the above-mentioned production method is a short polycondensation time, the production of a mixed terpolymer that can be processed by all available technologies, including injection molding - with high heat resistance - higher than 240 °C.

Example 1

The following components are introduced into a stirred reactor heated to 150 degrees Celsius:

melamine 24.30 kg urea 11.57 kg 6-caprolactam 10.10 kg CaCCb (ground 2.28 kg zinc stearate 1.50 kg TlO)2 0.30 kg capital blue 0.20 kg triethanolamine 0.70 kg mica (ground) 43.60 kg quartz (ground) 24.10 kg After 6 minutes to the heated mixture add- dosages formaldehyde (36%) 50.3 kg H3PO4 0.6 kg

With intensive stirring, polycondensation takes place at a temperature of 110 °C within 10 minutes, the resulting product in the form of granules is dried at a temperature of 100 °C and a pressure of 0.1 MPa within 10 minutes and is ready for further use.

The polymer has an initial degradation temperature of 273 °C, the degradation rate determined by the differential scanning calorimetry method (DSC) is 0.0351 mV/cm mg.

Example 2

The following components are introduced into an intensively stirred reactor at a temperature of 60 °C: melamine 24.50 kg urea 2.50 kg 6-aminocaproic acid 21.60 kg aspen cellulose 24.30 kg calcium carbonate 3.50 kg triethanolamine 0.70 kg formaldehyde (36%) 50.30 kg formic acid (60%) 1.50 kg

Polycondensation takes place within 50 minutes, the resulting product in the form of granules is dried under a vacuum of 0.08 MPa for 15 minutes at a temperature of 80 ° C. The prepared aminoplast has an initial degradation temperature of 241 ° C and a degradation rate determined by the DSC method of 0.4753 mV/cm mg.

Example 3

The following components are introduced into the intensively stirred reactor: melamine 2.50 kg urea 24.50 kg

12-laurolactam 0.90 kg 11-aminoundecanoic acid 0.90 kg calcium carbonate (precipitated) 2.00 kg spruce wood flour 20.00 kg formaldehyde (36%) 48.50 kg glass fiber 4.00 kg zinc stearate 1.50 kg triethanolamine 0.70 kg

H3PO4 0.60 kg

The raw materials in the reactor are heated to 100 °C within 5 minutes and polycondensation takes place within 30 minutes. Then the resulting product in the form of granules is dried under vacuum of 0.05 MPa within 5 minutes and is ready for further processing. The resulting product has an initial degradation temperature of 245 °C and a degradation rate determined by the DSC method of 0.3500 mV/cm mg.

Claims (1)

SUBJECT A process for producing a mixture of heat-resistant modified aminoplasms by condensation of a mixture of melamine and urea with formaldehyde at a temperature of 60 to 150 ° C in a single fluidized operation in the presence of fillers, dyes, catalysts and lubricants, INVENTION that the condensation is carried out in the presence of 5 to 80% by weight of the modifiers 6-caprolactam and / or ε-aminocarboxylic acid, based on the total weight of melamine and urea. -