SU523643A3 - The method of obtaining polyurethane urea in highly dispersed form - Google Patents

Description

bavlene trihydric alcohols, with polyaxial, preferably dibasic carboxylic acids. Instead of free polycarboxylic acids, corresponding polycarboxylic anhydrides or corresponding polycarboxylic esters of lower alcohols or mixtures of them can be used to produce polyesters. Polycarboxylic acids can be aliphatic, cycloaliphatic, aromatic and / or heterocyclic and can be unsaturated and / or substituted, for example, by halogen atoms.

The following compounds are given as examples: succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid anhydride, phthalic acid anhydride, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, tetrachlorophthalic acid (anhydride, endomethylene acid), glutaric anhydride, maleic acid, maleic anhydride, fumaric acid; dimeric and trimeric fatty acids such as oleic acid, which can be mixed with monomeric fatty acids; dimethyl terephthalate and bis-glycol ester of terephthalic acid. The following compounds are examples of suitable polyhydric alcohols: ethylene glycol, propylene-1,2- and -1,3-glycols, butylene-, 1,4- and -2,3-glycols, hexane-1,6-diol, octane 1,8-diol, neopentyl glycol, cyclohexanedimethanol (1,4bis-oxIMethelcyclohexane), 2-methylpropan-1,3 -diol, glycerin, trimethylolpropane, hexa1, 2,6-triol, butane-1,2,4-triol, trimethylol ethane , pentaerythritol, quinite, mancite and sorbitol, methylglucoside, dystilenglycol, triethyleneglycol, tetraethyleneglycol, polyethylene glycol, dipropyleneglycol, polypropyleneglycols, dibutyleneglycol and polybutylene glycols Polyesters may contain a number of terminal carboxyl groups. Lactone polyesters, such as e-caprolactone, or hydroxycarboxylic acids, such as u-hydroxycaproic acid, can also be used.

Undesired polyethers containing from 2 to 8, preferably 2 or 3 hydroxyl groups can be prepared, for example, by polymerizing epoxides such as ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin, for example in the presence of boron trifluoride, or adding these epoxides, which can be added as mixtures or sequentially, to such starting materials containing reactive hydrogen atoms, such as alcohols or amines, such as water, ethylene glycol, propylene-1, 3- and whether -1,2-glycol, trimethylolpropane, 4,4-dioxydiphenylpropane, aniline, ammonia, ethanolamine or ethylenediamine. Often

It is preferred to use polyethers in which most hydroxyl groups are primary hydroxyl groups (up to 90% by weight of all hydroxyl groups contained in the polyether). Also suitable polyethers, which are modified with vinyl polymers, for example, those that can be obtained, for example, by polymerization of styrene or

acrylonitrile in the presence of polyethers (see US Pat. Nos. 3383 351, No. 3 304 273, No. 3 523 093 and No. 3 110 695 and German Patent No. 1 152 536), and polybutadienes containing hydroxyl groups. Among the polythioethers, the condensation products of one thiodiglycol and / or other glycols, dicarboxylic acids, formaldehyde, aminocarboxylic acids, and / or amino alcohols should be indicated. Depending on the component used together with the thiodiglycol component, the products obtained are polyether polyether ethers-polyether at the same time simple and complex, amide polythioether

simple and complicated.

Suitable polyacetals are, for example, compounds that can be obtained from glycols such as diethylene glycol, triethylene glycol, 4,4-dioxyethoxydiphenyl dimethyl methane, hexanediol and formaldehyde. Polyacetals suitable for carrying out the process of the invention can also be obtained by polymerization of cyclic acetals. Polycarbonates with hydroxyl groups can be known polycarbonates, for example, those which can be obtained by reacting such diols as propane1, 3-diol, butane-1,4-diol and / or hexane-1,6-diol, diethylene glycol, triethylene glycol or tetraethylene glycol, with diaryl carbonate, for example, with diphenyl carbonate or phosgene. Amides of polyesters and polyamides include, for example, predominantly linear condensates derived from polybasic saturated and unsaturated carboxylic acids or their anhydrides and polyatomic saturated and unsaturated amino alcohols, diamines, polyamines, and mixtures of them.

Polyhydroxy compounds already containing urethane or urea groups and natural polyhydric alcohols that can be modified, for example, castor oil, carbohydrates or starch, can also be used. Addition products of alkylene oxides to phenol-formaldehyde resins or urea-formaldehyde resins are also suitable for practicing this invention.

The diisocyanates or polyisocyanates used to convert polyhydric alcohols to prepolymers containing isocyanate groups can be aliphatic, cycloaliphatic, arali (|) atic,

aromatic or heterocyclic polyisocyanates. Ethylene diisocyanate, tetramethylene-1,4-diisocyanate, hexamethylene-1,6-diisocyanate, dodecan-1, 12-diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane-1,3- and -1,4 are used, for example. -diisocyanates and any mixtures of these isomers; 1-isocyanato - 3,3,5 - trimethyl-5-nzocyanatomethylcyclohexane, hexahydrotolylene - 2,4 - and -2,6-diisocyanate and any mixtures of these isomers; hexahydrofenylene-1, 3- and / or -1,4-diisocyanate, rehydro-2,4- and / or -4,4-diisocyanate, phenylene-1, 3- and -1,4-diisocyanate, tolylene-2, 4- and -2,6-diisocyanate and any mixtures of these isomers; diphenylmethane-2,4- and / or -4,4-diisocyanate, naphthylene-1,5-diisocyanate, triphenylmethane-4, 4,4 -triisocyanate, polyphenylpolymethylenepolyisocyanates (and obtained by condensation of aniline with formaldehyde with subsequent phosgenation); perllogenie containing ethereal gruzytsy and tsotvuh reaction of the above listed isocyanates with acetals.

It is already known that the foriolimer containing isocyanate groocers, from polyatomic scattering and isociatzate, is crushed. The extensions for the isocyanate prepolymers are compounds containing at least two active Tserevititz hydrogen atoms in each molecule and have a molecular weight from 18 to 500. These compounds react with the isocyanate groups of the boropolymers and create high molecular weight polyurethane or polyurethane urea by combining some isocyanate prepolymer molecules.

The chain extension reaction is also known. Of the known chain extenders, water, amiostats containing hydroxyl groups and amino nodules, aminosulfonic acids and aliphatic, cycloaliphatic or aromatic amines, including hydrazine, are particularly suitable. The following are examples of such price extenders: water, hydrazic, ethilendcamine, croczen-, 2-diamine, crocylen-1,3-diamine, tetramethylenediamine, hexamethylenediamine, diethanolamine, diisopropanolamine, K, L-bis (3-aminopropyl) -ethylene diamine , N, Nbis- (2-aminocropyl) ethylene diam n, N, iN-6Hc (2-aminoethyl) ethylene diamine, N, N-6Hc- (2-aminocyrocyl) ethylene, N, N-6Hc- (2- amino-ethylethylenediamine, 4,4-dimethylaminodiphenylmethane, 4,4-dimethylamino-3,3-dimethyldiphenylmethane, 4,4-diamicycodimecylmethane, 2,4- and 2,6-diaminotoluenes and taurine. The molar amount of chain extenders used is usually equal to the number of isocyanate grits available. The mole ratio is preferably 1 (active hydrogen in the chain extension), but it is possible, however, it is possible to crimp the amount of extensions (1) approximately to the ratio NCO:, 8, preferably up to 1.5. In this case, the molecular weight of the polyurethanes or

urea and urea will be lower, and their flushing temperature will also be lower. The aqueous phases are preferably water or aqueous solutions of emulsifiers. Emulsifiers are usually used in amounts from 0.1 to CO. Weight. % Amount of water

phase is preferably 50 -

80 weight. % of the solution on the isocyanate fortsolimer.

Together with or instead of emulsifiers

so-called “laminators can also be used.

The reaction is preferably carried out at a temperature at which all the reagents are liquid, but it should not be higher than the decomposition temperature of the starting components and the polyurethane or polyurethane urea produced by the reaction. It is usually necessary to work with excess pressure; pressure should be at least higher than the pressure of the king of the volatile components. This method is preferably carried out at a temperature of from 50 to 150 ° C. In a zone of high turbulence, the temperature should be, in all cases, higher than the melting point of the isocyanate

forcolymer, since only then products will be obtained in the form of uniform spherical particles.

In the framework of this invention, the iodine zone of high turbulence should be understood, in

basically, the space through which at least 300 volume parts of the liquid flow per volume part of the space per hour under conditions of strong movement. The liquid is preferably compliant with

from 1200 to 5200 parts by volume

PA volume of the turbulent zone per hour.

Mixing time in high zone

turbulence is in this case from

0.2 to 6.0 seconds

A zone of high turbulence is usually created using a known apparatus, for example, a boiler with a disk and baffles and flow distributing elements at a ratio of the diameter of the boiler to the diameter of the stirrer from 1.0: 0.9

up to 1.0: 0,2. During the formation of such an acid, various agents can be separated separately: one component (for example, the water phase of the extender) is introduced directly into the cone of the blender, and the other component (for example, isocyanate

The result is that the two components are first emulsified, and then the emulsified product is ruled, and then the emulsified color is subjected to the elongation reaction.

With strong mixing, the power is usually from up to 10 W / cm, and in

the cone itself is higher. Therefore, the power is sometimes sufficient to emulsify low-viscosity polymers. More suitable for carrying out this method are the robots equipped with rotors, mainly because the time spent in them is strictly limited.

Extremely vigorous agitation in a very short residence time can be achieved in vras, homogenizers, and therefore it is preferable to use these devices. They have a very high capacity — the specificity of the mixing of the vras, of the homogenisers being in the range of about 5 to 25 W / cm.

This method can be carried out simultaneously, but separately, by feeding all three components or two components to a zone of high turbulence, for example, it is possible to mix the aqueous phase with a chain extender. This is recommended especially if the chain extender dissolves in water. It is also possible to supply reagents to a high turbulence zone in different places and, if desired, the flow of an individual component can be divided into several partial flows, for example, the prepolymer and the aqueous phase can be supplied at the beginning of the high turbulence zone, and the extension chain can be simultaneously fed in several locations - at the beginning, in the middle and / or at the end of the zone of high turbulence. According to a particularly advantageous embodiment of this method, the reaction mixture is passed through a zone of decreasing temperature.

Since the chain extension reaction is carried out quickly at high temperatures, in a zone of high turbulence it is recommended to operate at high temperatures. In order to continuously conduct the reaction with an optimal degree of conversion and, for example, to change the particle size of the obtained product, additional zones of high turbulence may be located behind the high turbulence zone, which have a decreasing temperature. For example, in the first zone of high turbulence, it is possible to maintain the temperature above the melting point of the raw materials and the polyurethane produced, in the subsequent reaction zone it can be maintained at a temperature similar to that of the polyurethane and prepolymer, and in the subsequent cooling zone it can be maintained below the softening temperature of polyurethane or polyurethane urea. Step polymerization can be terminated by washing the reaction mixture with acidified water.

FIG. Figures 1 and 2 show diagrams of two installations, with the help of which the proposed method of obtaining polyurethane urea can be carried out in a highly dispersed form.

One of these units (see Fig. 1) has a mixer 1, into which a copolyate polymer from a reservoir 2 is continuously supplied through a gear pump 3 and a valve 4 and an emulsifier and a chain extension are simultaneously supplied through supply piston pumps 5 and 6, valves 7, a mixer 8, the heat exchanger 9 and the return valve 10.

The isocyanate prepolymer is emulsified in mixer 1, the for-polymer forming the dispersed phase of the emulsion. In this apparatus, the chain elongation reaction is also carried out.

prepolymer simultaneous feed chain extender. The emulsion prepared in the mixer 1 is fed through a pressure regulating valve 11 and a pH measuring device 12 to the reactor 13, where the reaction is completed.

The chain extension can be fed directly into the mixer 1 through the pump 14 and the ilS non-return valve or downstream of the mixer through the pump 16 and valve 17. If desired, one part of the chain extension can be fed in one way and the other part in another way. The reaction is controlled depending on the pH value.

In another installation (see Fig. 2), the isocyanate prepolymer from extruder 2, the water phase from tank 3 through the feed piston pump 4, the return valve 5 and heat exchanger 6 and the chain extension from tank 7 are simultaneously fed into mixer I and simultaneously through

the feed piston pump 8 and the return valve 9. The emulsion obtained in the mixer 1 flows into the receiving tube 10 of the heat cycle. A portion of the emulsion is returned from this tube to the mixer, and the remainder is fed through a tapering opening 11 to the receiving tube 12 of the cooling cycle. Part of the contents of this pipe through the cooler 13 and the centrifugal pump 14 circulates for cooling, and the rest is discharged through the tank

15. The entire plant is pressurized with nitrogen supplied from tank 16 to collection tube 12 and tank 15.

In the examples below, the method is carried out in an installation that is shown on

FIG. one.

Example 1. A isocyanate prepolymer based on adipic acid polyether and a glycol with a molecular weight of about 2000, containing 9% free, are continuously fed to a rapidly rotating 0.15 L homogenizer with a rotation speed of 6000 rpm and a specific mixing power of 23 W / cm. isocyanate groups, polyether from adipic acid, hexane-1,6-diol and neopentyl glycol with a molecular weight of about 1,700 and hexamethylene diisocyanate in an amount of 80 kg / h at a temperature of 100 ° C and at the same time an aqueous solution of emulsifier (0.2% solution stiromala ins) in an amount of 300 l / h at 90 ° C. Two liquids flow separately directly into the zone of displacement of the homogenizer. An emulsion is obtained in which the prepolymer forms a dispersed phase. Simultaneously, the isocyanate prepolymer is reacted with water, as a result. Note: In all examples, the prepolymer temperature is 100 ° C, the aqueous phase is 90 ° C.

those of which the chain is lengthened and formed by the urea. The volume of flow per hour is 2530: times the capacity of the homogenizer. The emulsion is fed to a receiving vessel, where it is maintained at 90 ° C with stirring for 15 minutes and then cooled. The emulsion separates into a concentrated upper layer and a separated liquid, with the upper layer having a concentration of from 30 to 50% very thixotropic. After removing the precipitated liquid, the concentrate can be dried with iB shelf dryers or continuous air dryers to obtain a polyurethane powder. A very fine free-flowing powder is obtained with a particle size of from 1 to 50 microns and a melting point of 180 ° C.

Examples 2-17. The procedure is the same as in Example 1, however, with changing experimental conditions, the chain extension is caused by the addition of ethylenediamine to the aqueous phase. The conditions of the experiments are listed in the table.

Example 18. The experiment was carried out under the conditions of example 5, with one half of the amount of chain extender being fed to the displacement zone of the homogenizer, and the other half to the reactor only after emulsification. The resulting powder is finer than the powder obtained in Example 5.

Examples 19 and 20 use the setup shown in FIG. 2

Example 19. A rotating polycarbamide prepolymer containing 2% of free isocyanate groups based on ether is continuously fed at 120 ° C to a rotating 0.15 L homogenizer with a rotation speed of 6000 rpm and a specific mixing power of 23 W / cm. adipic acid and glycol with a molecular weight of about 2000, polyester from adipic acid, hexane-1,6-diol, and neo-peitylglycol with a molecular weight of about 1700 and

hexamethylene diisocyanate in the amount of 10 kg / hour and at the same time an aqueous solution of emulsifier (0.2% aqueous solution of styromalamine) in the amount of 40 kg / hour and at a temperature of 100 ° C is supplied. At the end of the zoe high

turbulence homogenizer as a chain extender separately serves 10% aqueous solution of etilepdiamine in the amount of 1.43 kg / hour. The emulsion formed in the homogenizer is supplied at a temperature of 120 ° C to

the reaction tube. In the reaction tube, the chain extension reaction is completed, and the uneven oval or fibrous particles formed in the homogenizer become spherical. After passing through the reaction tube, part of the emulsion is returned by the action of a homogenizer to the emulsifying apparatus. This makes it possible to regulate the concentration of the emulsion, regardless of the relative performance of the feeding devices. At the same time, the pressure difference at the loading and unloading ends of the rotating homogenizer is eliminated. The amount of the emulsion, corresponding to the additionally supplied amounts of reagents, is fed through a narrowing opening into the cooling cycle and cooled in the receiving tube to 50 ° C. A portion of the suspension is circulated to accelerate cooling. The overpressure in the apparatus with nitrogen is set to 3 bar to

The volatile component itself did not boil, and if necessary, the pressure is regulated by draining the suspension from the pressure vessel through the valve. The resulting suspension is processed into a fine powder

analogously to example 18. The sintering temperature of the powder was 150 ° C.

Example 20 The procedure is similar to Example 19, but 1.1 kg of 10% ethylenediamine per hour are used. Molar ratio H: NCO

,eight. Derived from highly dispersed sug11

Penza powder has a sintering temperature of 95 ° C.

Claims (2)

1. A method of producing polyurethane urea in a highly dispersed form by mixing an isocyanate prepolymer, a chain extender, an aqueous medium, and separating the resulting product. The product is distinguished by the fact that, in order to simplify the process and increase its efficiency, the initial components are separately fed to the mixing zone, and the mixing is carried out with a mixer with a capacity of 5 to 25 W / cm for 0.2-6.0 seconds 2. A method according to claim 1, characterized in that the chain extender and the aqueous medium are mixed prior to being supplied to the mixing zone. s j l. | I j