CS260797B1 - Method of high-molecular alpha omega diamines preparation - Google Patents

Abstract

The method of production of ω-diamines is solved, high molecular weight, polyurethane prepolymer containing 0.8% to 6.6% hniot. free NCO groups on a linear basis dihydroxysuccinins and diisocyanates by reaction with water in intensely mixed water a phase containing a dispersant and other auxiliary at a temperature up to 93: C with the reaction 5 to 60 minutes. The advantage of the procedure there is a possibility of preparing diamine with different structure and molecular weight simple and for investment a equipment in a modest way. Di- solutions prepared can be successful To be used in additives and modifiers for polymers basic series such as PVC, PA, polyolefins.

Description

The invention relates to a process for the preparation of, in particular, high molecular weight α, ω-dlamines having a content of 0.5 to 0.005% by weight. amino. The process of preparation in terms of technology and machinery is simple and does not require increased investment requirements.

High molecular weight diamines find application as excellent modifiers for polymers, e.g. polyvinyl chlorides, polyamides and polyolefins.

Generally, the amino or diamino compounds are prepared from nitro compounds, nitro compounds or nitriles by low or high pressure hydrogenation in the presence of a catalyst, e.g. Raney nickel, Raney media, nickel or cobalt on alumina and silica carriers and the like. Thus, amines, or diamines, in particular of the basic series, are prepared, and these processes are not applicable to high molecular weight amines.

For the preparation of higher amines and diamines, processes for the hydrogenation of higher fatty acid nitriles and hydrogenation of α, ω-dicyanopolyethylene glycols obtained by cyanoethylation of polyhydroxy compounds, for example: polyethylene glycols having an average molar mass of 800-4000 (AO No. 181 846 (1977)), are known. however, it is multi-tiered, technologically demanding with high investment requirements.

According to the present invention, the preparation of α, ω-diamines of high molecular weight with a plasticization temperature of up to 180 ° C is carried out in such a way that a polyurethane pre-polymer containing 0.8 to 6.6, preferably 1.6 to 4.2% by weight. of the free-NCO groups, is reacted with water in a vigorously stirred aqueous phase in the presence of a dispersant at a temperature of 20 to 95 ° C, preferably 45 to 85 degrees Celsius for 5 to 60 minutes, the diamine having a molecular weight of 15000 to 150,000 g.mol ^-1 , as a rule in the powdered state, containing 0.5 to 0.005 wt. The amino groups are isolated from the dispersion system formed.

An advantage of the process for the preparation of the polymeric diamines according to the invention lies in the possibility of preparing diamines with a different amino group content in the range of 0.5 to 0.005% by weight. and the different structure of the polymer chain. Wide variability in structure and moles. the weight is achieved by selecting the reaction conditions, mainly the type and concentration of the dispersant and the reaction temperature, and also the starting materials used in the preparation of the prepolymer, with the possibility of preparing a polymer chain of aliphatic, aromatic or mixed character.

Other advantages include the preparation of a product of the desired consistency, either in a stable dispersion state or in a particle size and distribution of from 50 to 2000 µm.

Last but not least, the method is technologically quite simple, without requiring increased demands on machinery and equipment, energy and operation.

The preparation of the diamines is carried out in an intensively mixed system consisting of a polyurethane prepolymer, always and a dispersant, the weight of which is chosen according to the starting materials used and the desired properties of the final product. Water, as a dispersing medium, participates in a two-step reaction with the —NCO group of the prepolymer, elimination to form amino groups, and subsequent polyaddition reaction with the other —NCO groups, to extend the chain and form a macromolecular compound.

Polyurethane pre-polymer with a content of 0.8 to 6.6 wt. The free —NCO groups are prepared by reacting compounds containing effective hydrogen, usually dihydroxy compounds, with a molar. weight of 100 to 10,000 with diisocyanates at 60 to 120 ° C for 0.5 to 4 hours under stirring under inert gas.

Of the active hydrogen-containing substances, the most commonly used are polyhydroxy compounds, mainly polyester polyols based on adipic acid, phthalic sebacic acid and the like. and polyhydric alcohols such as ethylene glycol, diethylene glycol, 1,2-protanediol, 1,4-butanediol, pentaerythritol, trimethylolpropane, by mol. weight 500 to 10 000, no. acidity below 1 mg KOH / g, hydroxyl. no. 30 to 150 mg KOH / g.

Another group consists of polyether polyols prepared after propoxylation of glycerin, trimethylolpropane, but also polyethylene glycols with moles. weight of 300 to 6,000; polyipropylene glycols with mol. by weight of 500 to 3500, polyacetates, polycarbonates, polythioethers either alone or in mixtures,

The isocyanates used are aliphatic and aromatic, in particular disocyanates, most commonly:

4.4-methanediphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate,

2.5- naphthyl diisocyanate, but also others.

The dispersing agents used are, in particular, cellulose esters, in particular methylhydroxypropylcellulose, further partially hydrolyzed polyvinyl alcohols having a molar mass of 20,000 to 100,000, gelatin, styrene-malenic anhydride copolymer (Styromal), generally in the form of 1-5% aqueous solutions. The type and batch of dispersing agent generally range from 0.01 to 0.7% by weight. decisively affects the particle size distribution of the obtained dispersion documented in the examples.

The weight ratio of the prepolymer to the aqueous phase is selected relative to the raw materials used, e.g. according to the viscosity of the prepolymer, to the properties of the final product, e.g.

the particle size of the dispersion, the absorptivity of the polymer, but also to the economic balances and ranges from 1: 20 to 1: 3, which corresponds to a content of 5 to 30% by weight. of a polymeric diamine y system.

The preparation process can be carried out batchwise in mixers and mixers at 1000 to 4000 rpm, or in a continuous manner by mixing the prepolymer streams and the aqueous phase in a zone of high turbulence or countercurrent injectors.

Example 1

A prepolymer having a content of 4.6% by weight is used to prepare the polymer diamine. of free NCO groups prepared by reaction of 1200 g of polyethylene glycol PEG 600 (average molecular weight 600 g mole ^-1 , water content 0.05 wt%, sodium + potassium content 2 ppm, hydroxyl value · 185 mg KOH / g J and 750 g of 4,4'-methanediphenyl diisocyanate at 85 ° C with stirring for 30 minutes 200 grams of 65 ° C prepolymer are continuously fed for 2 minutes to a vigorously stirred aqueous phase heated to 70 ° C consisting of 700 g of distillation. water and 100 g of a 2% aqueous solution of methyl hydroxypropylcellulose.

An ETA-MIRA mixer at 3000 rpm was used to create a vigorously stirred system. After a reaction time of 10 minutes, the resulting dispersion is separated by filtration and dried at 90 ° C. The polymeric diamine has a particle size of 250 to 1000 µm, an average mole. weight 25,000 g mol ^-1 , content of —NH2 groups 0.15% by weight, plasticization temperature 120 ° C, and is particularly suitable as a reactive antistatic additive in polyamide fibers. Example 2

Pre-polymer of 2.5 wt. free —NCO groups are prepared by reacting 1500 g of polyethylene glycol PEG-3000 (average molecular weight 3,000 g mol ^-1 , hydroxyl value 40.5 mg KOH / g, water content below 0.1 wt%, sodium content -j-) potassium (0 ppm) and 170 g of hexamethylene diisocyanate for 30 minutes at 85 ° C. A 100 g prepolymer of 70 [deg.] C. is introduced into a stirred aqueous phase of 1000 cm @ ^{3 of} distilled water and 300 g of a 2% aqueous solution of methylhydroxypropylcellulose heated to 85 [deg.] C. over a period of 2 minutes. separates the water system on a centrifuge and dried. Polymeric diamine in the form of irregular particles with max. has a bulk density of 400 g / dm ³ , an average mol. weight 100,000 g mol ^-1 , content of —NH2 groups 3.2. . 10 ^-2 % by weight, plasticizing temperature 165 degrees Celsius and high water absorption of 450% by weight. It is suitable as a hydrophilic additive to polyester and polyamide fibers.

Example 1 and d 3

Polyurethane prepolymer containing 1.5 wt. The free —NCO groups are obtained by reacting 800 g of polyester polyol prepared from adipic acid and ethylene glycol (Desmophen 2000, molecular weight 2,000 grams mol ^-1 , hydroxyl value 56 mg KOH / g, acid number 0.8 mg KOH / g, water content 0.03 wt%, melting point 55 ° C) and 103 g toluene diisocyanate (80/20 mixture of 2,4- and 2,6-isomers) at 90 ° C for 1 h. The feed 300 g of the prepolymer is supplied to 800 g of water containing 4.1 g of partially hydrolyzed polyvinyl alcohol (average molecular weight 35,000 g mol ^-1 ) relatively quickly in 30 s.

The polymeric diamine prepared according to Example 1 has a mole. weight 150,000 g mol ^-1 , content of —NH2 groups 2.10 ^-2 percent by weight, plasticization temperature 165 degrees Celsius, particle diameter 50 to 150 μτη and can be used as a polyvinyl chloride toughness modifier.

Example 4

According to the procedure of Example 1, a prepolymer having a content of 1.8 wt. —NCO prepared from 800 g of polyetherpolyol obtained by propoxylation of trimethylolpropane (Slovaprop TMP-56, hydroxyl value 56 mg KOH / g, acid value 0,1 mg KOH / g, average molecular weight 2 000 g mol ^-1 , sodium and potassium content below 1 ppm) and 150 g of 4,4'-methanediphenyldilzoocyanate.

000 g of prepolymer at 80 ^Q C for 3 minutes was added to the rapidly agitated aqueous phase consisting of 30 dm ³ of distilled water and 1 dm ³ · 5% aqueous solution of polyvinyl alcohol (mol. Weight of 100 000 g ^mol-1) and preheated to at 80 ° C in a stainless steel mixer and the number of revolutions of 2800 ^min-1 and after 25 minutes the solid was filtered off and dried. The diamine is obtained in the form of irregular particles having a size of 0.8 to 2 mm, having an amino group content of 0.07% by weight, medium mol. weight 45,000 g mol ^-1 , bulk density 350 g / dm ³ and plasticization temperature 125 degrees Celsius.

Claims (1)

A process for the preparation of high molecular weight α, ω-diamines having a plastification temperature of up to 180 ° C, characterized in that the polyurethane prepolymer containing 0.8 to 6.6%, preferably 1.6 to 4.2% by weight. The free —NCO groups are reacted with water in a vigorously mixed aqueous phase in the presence Of the dispersing agent at a temperature of 20 to 95 ° C, preferably 45 to 85 for 5 to 60 minutes, wherein the diamine, having a molecular weight of 15,000 to 150,000 g, mol ¹ , generally in the powdered state of 0.5 to 0.005 ° The amino groups are isolated from the dispersion system formed.