CS260797B1 - Method of preparation of high molecular weight α, ω-diamines - Google Patents

Abstract

A method of producing «,ω-diamines, high molecular weight, from a polyurethane prepolymer, containing 0.8 ' to 6.6 % by mass of free —NCO groups based on linear dihydroxy compounds and diisocyanates by reaction with water in an intensively stirred aqueous phase, containing a dispersant and other auxiliary substances at temperatures up to 93 :C with a reaction time of 5 to 60 minutes is solved. The advantage of the process is the possibility of preparing diamines with different structures and molecular weights in a technologically simple and low-cost method for investments and equipment. Diamines prepared according to the solution can be successfully used as additives and modifiers for basic polymers such as PVC, PA, polyolefins.

Description

260797 3 4

The present invention relates to a process for preparing especially high molecular weight α, ω-diamines containing 0.5 to 0.005% by weight of amino groups. The method of preparation from university and machinery is simple and does not require increased investment requirements.

High molecular weight diamines are found to be excellent modifiers for polymers such as polyvinyl chlorides, polyamides and polyolefins.

Generally, amine or diamine compounds are prepared from nitro compounds, nitro compounds, or nitriles by low pressure or high pressure hydrogenation in the presence of a catalyst such as Raney nickel, Raney medium, nickel or cobalt on alumina and silica carriers, and the like. . In this way, the amines, or diamines, respectively, are particularly suitable for the basic series, and are not applicable to high molecular weight amines.

For the preparation of higher amines and diamines, processes for the hydrogenation of nitrile fatty acids and hydrogenation of .alpha.-dicyanopolyethylene glycols obtained by cyanoethylation of polyhydroxy compounds are known, e.g. multi-stage, technological complexity with high investment requirements.

According to the invention, the preparation of α, ω-di-amines of high molecular weight, with a temperature of up to 180 ° C, is carried out in such a way that the polyurethane predipolymer containing from 0.8 to 6.6% by weight, preferably 1.6 to 4.2% by weight, is free. The NCO groups are reacted with water in an intensively stirred aqueous phase in the presence of a dispersing agent at a temperature of 20 to 95 ° C, preferably 45 to 85 degrees Celsius for 5 to 60 minutes, with diamine having a molecular weight of 15,000 to 150,000 g.mol -1, generally in powder form with a content of 0.5 to 0.005% by weight. the amino groups are isolated from the formed dispersion system. An advantage of the process of preparing the polymeric diamines of the present invention is the ability to prepare diamines having different amino groups in the range of 0.5 to 0.005% by weight. and a different polymeric chain structure. Wide variability in structure and pier. weight is obtained by selecting the reaction conditions, especially the type and concentration of the dispersant and the reaction temperature, as well as the starting materials used to prepare the prepolymer, with the possibility of preparing a polymeric chain of aliphatic, aromatic or mixed nature. Other advantages include the preparation of the desired consistency product in a continuous dispersion or size and distribution range of from 50 to 2000 μΐη. Last but not least, it is technically quite simple, not requiring increased demands on machinery, energy and service. The preparation of the diamines is carried out in an intensively mixed system consisting of a polyurethane prepolymer, in the form of a dispersing agent, the weight of which is chosen according to the starting materials used and the desired properties of the final product. Water, in addition to the dispersing medium, participates in the two-step reaction with the NCO group of the prepolymer, elimination to form an amino acid, and their subsequent polyaddition reaction with the residual NCO groups results in chain extension and macromolecular compound formation.

Polyurethane prepolymer having a content of 0.8 to 6.6 wt. free-NCO groups are prepared by reacting effective hydrogen containing compounds, typically dihydroxy compound, with molar amounts. 100 to 10,000 with diisocyanate at 60 to 120 ° C for 0.5 to 4 hours under stirring under an inert gas atmosphere. Of the active hydrogen-containing substances, polyhydroxy compounds, especially polyester polyols based on adipic acid, phthalic sebacic acid and the like, are most commonly used. and polyfunctional alcohols such as ethylene glycol, diethylene glycol, 1,2-propanediol, 1,4-butanediol, pentaerythritol, trimethylolpropane, omol. weight 500 to 10,000, acidity no 1 mg KOH / g, hydroxyl. No. 30 to 150 mgKOH / g. Another group consists of polyetherpolyols prepared after propoxylation of glycerin, trimethylolpropane, but also polyethylene glycols with a molecular weight of 300-6000, polyipropylene glycols with a molar. with a weight of 500 to 3,500, polyacetates, polycarbonates, polytioethers either alone or in mixtures,

The isocyanates used are aliphatic iaromatic, especially disocyanates, most commonly: 4,4-methanediphenyl diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, 2,5-naphthyl diisocyanate, and others.

The dispersing agents used are in particular cellulose esters, in particular methyl hydroxypropyl cellulose, furthermore partially hydrolysed polyvinyl alcohols having a molar mass of 20 000 to 100 000, gelatin, a styrene-malenanhydride copolymer (Styromal) generally in the form of 1 to 5% - water solutions. Generally, the type and amount of dispersing agent is in the range of 0.01 to 0.7% by weight. decisively affects the particle size distribution of the obtained dispersions documented in the examples.

The weight ratio of the prepolymer to the water phase is selected with respect to the raw materials used, for example according to the viscosity of the prepolymer, to the properties of the final product, e.g. 260797 with 6 particle size dispersions, polyiromeric absorption, but also to economic balances and movements. in a 1: 20 to 1: 3 ratio, which corresponds to a content of 5 to 30% by weight. polymer diamine.

The preparation process can be carried out continuously in mixers and mixers with a rotational speed of 1000 to 4000 rpm, but in a continuous manner by mixing the streams of the prepolymer and the aqueous phase in the high turbulence zone; in countercurrent investors. Example 1

A prepolymer having a content of 4/6% by weight of free NCO groups prepared by reaction of 1200 g of polyethylene glycol PEG 600 (average molecular weight 600 g / mol, containing 0.05% w / w) is used to prepare the polymer diamine. , sodium + potassium 2 ppm, hydroxyl number - 185 mg KOH / g) and 750 g of 4,4'-methanediphenyl diisocyanate at 85 ° C with stirring for 30 minutes. 200 grams of the 65 ° C prepolymer were continuously introduced into an intensively stirred aqueous phase heated to 70 ° C for 2 minutes, consisting of 700 grams of distilled water and 100 grams of a 2% aqueous methylhydroxyipropyl cellulose solution.

The ETA-MIRA mixer with a rotational speed of 3,000 rpm was used to form an intensively mixed system. After a reaction time of 10 minutes, the product was separated from the dispersion by filtration and dried at 90 ° C. The polymeric di-amine has a particle size of 250 to 1000 µm, an average molar. the weight of 25,000 g mol-1, the content of -NH2 groups of 0.15 wt%, the plasticization temperature of 120 [deg.] C. is particularly suitable as a reactive antistatic additive in polyamide fibers.

Pre-polymer of 2.5 wt. free NCO groups are prepared by reacting 1500 g polyethylene glycol PEG-3000 (average molecular weight 3000 g mol-1, hydroxyl number 40.5 mg KOH / g, water content below 0.1% w / w content potassium-0 ppm) and 170 g hexamethylene diisocyanate for 30 minutes at 85 ° C. A 70 ° C prepolymer of 100 g was introduced into a stirred aqueous phase of 1000 cm 3 distilled water and 300 g of a 2% aqueous solution of hydroxypropylcellulose heated to 85 ° C with a gentle stream for 2 minutes and separated from the aqueous system after 15 minutes. on the centrifuge and dried. The polymeric diamine in the form of irregular particles with a maximum length of 2 mm, has a bulk density of 400 g / dm 3, an average mole. weight 100,000 g mol-1, content of -NH2 groups 3.2 .. 10-2 wt.%, plasticization temperature 165 degrees Celsius and high water absorption of 450 wt. It is suitable as a hydrophilic additive for polyester and polyamide fibers. Example 3

Polyurethane prepolymer with a content of 1.5 wt. of free NCO groups by reaction of 800 g of polyester polyol prepared from adipic acid and ethylene glycol (Desmophen 2000, molar mass of 2,000 grams mol-1, hydroxyl number of 56 mgKOH / g, acid number 0.8 mg KOH / g, contents of 0.03% by weight, melting point 55 ° C) and 103 g of toluene diisocyanate (mixture of 2,4- and 2,6-isomers 80/20) at 90 ° C for 1 hour. during 30 s, it supplies to 800 g of water containing 4.1 g of partially hydrolysed polyvinyl alcohol (average molecular weight 35,000 g mol-1).

The polymer diamine prepared in Example 1 has a molar. weight 150,000 g mol-1, content of NH 2 groups 2.10-2 per cent by weight, plasticization temperature 165 degrees Celsius, particle diameter 50-150 µm can be used as a modifier for the toughness of polyvinyl chloride. Example 4

According to the procedure of Example 1, the prepolymer of 1.8 wt. - NCO is prepared by 800 g of polyetherpolyol obtained by the propoxylation of trimethyl olpropane (S1-ovaproper TMP-56, hydroxyl number 56 mg KOH / g, 0.1 mg KOH / g, average molecular weight 2000 g mol-1, sodium and potassium content below 1 ppm) and 150 g of 4,4'-methanediphenyl diisocyanate. 3000 g of prepolymer at 80 ° C for 3 minutes are added to an intensively stirred aqueous phase of 30 dm 3 of distilled water and 1 dm 3 of a 5% aqueous solution of polyvinyl alcohol (100,000 g / mole) and heated to a temperature of 80 ° C in a stainless steel stirrer and a count of 2,800 rpm for 25 min, the solid product is filtered off and dried. The diamine is obtained in the form of irregular particles having a particle size of 0.8 to 2 mm, and has an amino group content of 0.07% by weight, streptomoles. 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.