DE1127082B - Process for the production of high molecular weight water-soluble or water-swellable polyaether urethanes - Google Patents

Description

Process for the production of high molecular weight water-soluble or water-swellable polyether urethanes It is known that diols react with polyisocyanates can be converted into high molecular weight products. Starting from ethylene glycol, propylene glycol and other lower alkylene glycols become water-insoluble, but in organic Solvents more or less soluble products obtained. If you apply the reaction on higher molecular weight polyethylene glycols, so arise, at least during implementation Equimolecular amounts of polyethylene glycol and diisocyanate, water-soluble compounds, which result in fairly highly viscous solutions. With the addition of diisocyanate in larger Quantities or of triisocyanate, on the other hand, result in products in this case too, which are insoluble or at most swellable in water.

High molecular weight starting materials for the purposes of the invention are polyethylene glycols and all products obtained by the addition of ethylene oxide either to lower polyhydric alcohols such as glycol, glycerol or pentaerythritol, or to relatively low molecular weight polyalkylene glycols that are not composed of ethylene oxide, for example polypropylene glycol will. If you put those starting materials that have, for example, a melting point (Kofler) of 60 ° C, a molecular weight (Staudinger) of about 20,000 and a viscosity (10%) of 17 to 18 cP and (50%) of 3500 cP, im In a molar ratio of 1: 1 to 1: 2 with hexamethylene diisocyanate, whitish masses of great toughness and hardness with the following properties are obtained: Polyadduct, polyadduct, low viscosity high viscosity Melting point (Kofler), ° C ............... 70 to 80 120 to 130 Viscosity, 20 ° C, cP, 10% in water ...... 30 to 40 400 to 600 50% in water ...... 26 400 almost solid Molecular weight (Staudinger) ........ 80,000 400,000 up to 90,000 to 600,000 As a result of the considerable difference in the molecular weights of the two starting materials, the products consist predominantly of components of the hydrophilic, water-soluble polyethers, on which only tiny amounts of relatively short, hydrophobic hexamethylene groups are distributed, so that these adducts have to be regarded as practically non-polar. The hydrophobic component could be increased if the hexamethylene diisocyanate could be replaced by higher molecular weight compounds such as octamethylene diisocyanate or octadecyl isocyanate. However, this is practically impossible because octamethylene diisocyanate is relatively difficult to access, while octadecyl isocyanate, with its only functional group, is unable to build up high molecular weight structures.

It has now been found that polyadducts with larger hydrophobic Proportions and, as a result, clearly polar character can be obtained by does not react polyethylene glycols alone with isocyanates, but rather high molecular weight ones water-soluble polyether urethanes produced by a mixture of A. a Essentially linear polyethylene glycol or adducts of ethylene oxide with low molecular weight polyhydric alcohols or polyglycols with a molecular weight of 7500 or higher, B. a connection with a long carbon chain, possibly interrupted by ether bridges, the two isocyanate-reactive groups and a molecular weight of 200 to about 2000, C. one of the reactive groups of the compounds A and B equivalent amount of a diisocyanate of the general formula R (NCO) 2, where R is an aliphatic, aromatic, hydroaromatic, araliphatic or heterocyclic Radical, optionally with ether bridges (O, S) or further substituents, means, or its dimeric, polymeric or masked modifications in Reacts in the absence of water. Preferably the reactant will B in amounts of about 3 to 20 percent by weight based on reactants A, applied. The reaction can take place in the presence of an inert solvent are executed.

Diols with an excess of diisocyanate are already used as products implemented containing free isocyanate groups and in a second operation Converted into films, foams or the like by adding water. In contrast for this purpose, the products prepared according to the invention do not contain any free isocyanate groups and dissolve or swell in water without further reaction. According to another known processes are made from monohydric fatty alcohols and the like by addition Ethylene oxide represented monoalcohols reacted with polyisocyanates. This creates initially only reaction products of 1 mole of diisocyanate with 2 moles of the alcohol, the then in turn in different directions with further amounts of the polyisocyanate react in a difficult manner. This creates products that are both in chemical constitution as in their physical properties and their technical usability basically of the products of the present invention distinguish what polar nature and linear structure in terms of practically infinite long thread molecules.

Possible reactants A are: addition products of Ethylene oxide to lower, di- or higher-valent alcohols, such as ethylene glycol, glycerine or pentaerythritol, or to relatively low molecular weight polyalkylene glycols, which do not contain any C2H4O groups, e.g. B. of polypropylene glycol of molecular weight 1000.

Polyethylene oxides with a molecular weight of about 10,000 are preferred applied to about 500,000.

Examples of possible reactants B are: diols such as Octadecanediol or low molecular weight, water-insoluble polyalkylene glycols (e.g.

Polypropylene glycol of molecular weight 2000); Dicarboxylic acids such as Sebacic acid or those obtained by oxo reaction from higher fatty acids such as oleic acid Dicarboxylic acids; Diamines such as the reduction products of the by addition Compounds of the type C18H37NH CH2CH2CH2NH2 obtained from acrylonitrile on monoamines and mixed substituted compounds such as oxyacids such as ricinoleic acid or oxystearic acid.

Important trifunctional compounds are especially castor oil and hydrogenated castor oil.

Reaction participants in group C include, for example: Hexamethylene diisocyanate or tolylene diisocyanate. Basically all connections are suitable, which correspond to the general formula R (N CO), where R is an aliphatic, is aromatic, hydroaromatic, araliphatic or heterocyclic radical, which also contains oxygen bridges, sulfur bridges and other substituents such as halogen atoms, and x is 2. Dimerized and polymerized are also suitable Diisocyanates, e.g. B. have uretdione rings. Finally, there are also such diisocyanates usable either by partial reaction with lower diols, diamines or shorter polyether chains or modified by Reaction with phenols and the like. are stabilized and therefore only effective as diisocyanates at higher temperatures will.

The proportions of the reactants A and B can, depending according to the desired properties of the end product. If you turn the respondent B in amounts of from about 3 to 20 percent by weight, calculated on the reactant A, on, this leads to predominantly water-soluble substances. Larger proportions of the Reactant B lead to products with decreasing water solubility and increasing distributability in organic solvents. The respondent C is in equivalent proportion to the amount of total reactants A and B applied.

If one uses as reactant A derivatives of trivalent or polyvalent ones Alcohols such as B. the reaction products of triols and ethylene oxide, and / or at B trifunctional compounds, such as. B.

Castor oil is always the result of already cross-linked, only more swellable Products.

To carry out the method of the invention, those are chosen Representatives of the reactants A, B and C in a kneader or other suitable Mixing vessel heated to a temperature at which the starting materials are liquid and which is also sufficient to cope with the increasingly tough reaction mixture as it progresses still to work through sufficiently. Temperatures generally come for this purpose from 100 to 150 "C. The suitable temperature range is expedient in individual cases determined by an experiment. The reaction product falls in the form of more opaque, mostly colorless masses that can be further processed in various ways.

Products that are difficult to dissolve can, for example, still be processed in suitable form in the kneader Solvents dissolved and used in this form directly as an adhesive or be cast in a thin layer to form a film.

Some process products can also be placed on cold or warm Ways to pull out films and threads and pour them into molds as melt. Also one Extrusion device with premixer is suitable as a reaction vessel and allows to carry out the process continuously.

Of course, the method can also be used in a suitable indifferent way Solvent run. The solutions thus obtained can either be of the reaction product directly for technical use, or isolated by distilling off the volatile constituents, the reaction products are solvent-free.

Since air and moisture can lead to disruptive side reactions, it is advisable to work in the absence of air and the starting materials before they are combined with each other by heating in vacuo or in some other way of to free any water present. Optionally, the ternary reaction can Invention by known catalysts, for example organometallic compounds, N-methylmorpholine or alkalis, accelerated or by known reaction retarders, like N-dimethylaniline. It is therefore easily possible as a reactant A use polyglycols which are still catalytic from their production Contains additives such as sodium ions or BF3. This results in an undesirable strong responsiveness or will rely on particular uniformity of the end products Added value, then these catalysts can be used by suitable Means, for example neutralization with acid or alkali, slightly in whole or in part inactivate.

When obtaining process products of very high molecular weight wants, is expedient for a relatively high purity of the reactants A, B, C to pay attention to.

To illustrate the numerous possibilities that the procedure of the invention, the overview below shows a number of exemplary embodiments with different reactants according to molar ratios, reaction temperature, Type and usability of the reaction product compiled. Example 1 In one A kneader equipped with a vacuum device is 900 parts of an industrial polyethylene glycol (A), the alkali catalyst of which is neutralized, with a molecular weight of 25,000 with 40 parts of octadecanediol (B) kept under vacuum at 100 to 110 ° C for so long until the small amount of water is completely removed. Then be 30 parts of hexamethylene diisocyanate (C) were added.

The ratio of OH to NCO groups is around 1: 0.95 here. Without a vacuum, the temperature is increased to 100 to 120 "C and held for 2 hours.

During this time, the mass takes on a tougher consistency. You get in practically quantitative yield an easily distributable in the heat, in the Cold-resistant, elastic material with the following properties: F. (Kofler) 55 ° C. 55C VZ 19 Viscosity of the 10% solution in water at 200 C (Visco balance) ... 230 P pn value of the above solution in water 7.8 By rolling on the calender it is extremely easy to obtain a film that gradually comes into contact with water disintegrates. Their strength is significantly higher in the rolling direction than in the transverse direction.

Their tensile strength in the longitudinal direction is 167 kg / cm2; strain 8 ° lo.

If you value completely unoriented films, then you can Bring the above-mentioned aqueous solution to dry on a flat surface; it arises a smooth cast film.

If you do the reaction with 900 parts of the same polyglycol, however with the addition of 50 parts of octadecanediol and 34 parts of hexamethylene diisocyanate, then you get a plastic-like product, which because of its extraordinary high viscosity in water as a thickener for various products, in particular Detergents and textile auxiliaries, is suitable.

Got from the melt or from the solution by hot spinning one to elastic fibers.

An approximately 5 above solution of this adduct in water can be used 80 "C with oleic acid in a ratio of 1: 1 (calculated on the solution) to a very stable one Turbine-type oil-in-water emulsion, which has the remarkable property has, with concentrated salt solutions, e.g. B. MgCl2, can be diluted without flocculation be. This behavior is important for the textile and potash industry. Relocated the 5 0/0 highly viscous solution with about the same weight of ansulfonated If you emulsify sperm oil in this mixture, you get an anti-chrome tanning salt stable tanning liquor.

The influence of the variation in the proportion of reactants A, B and C, especially with a view to reducing the amount of C, show the tables below.

Table 1 Approach no. 70/43 70/44 70/46 70/47 70/50 Parts mole parts mole parts mole parts mole parts mole Polyglycol 25000 900 0.036 900 0.036 900 0.036 900 0.036 900 0.036 Octadecanediol. . 50 0.1634 50 0.1634 50 0.1634 50 0.1634 40 0.1307 Hexamethylene isocyanate. . . . . 40 0.238 34 0.200 30.2 0.180 25.2 0.150 30 0.180 Table 2 Properties of the films Approach cast film rolled film No. W70 / 23 water-insoluble, parchment-like film, lich (swellable), which disintegrates in water; some tear strength in both directions supple and good; Tear strength: 147 kg / cm2 W70 / 44 brittle bad, not uniform Foil that dissolves easily in water is lich; Firmness mediocre; Tear strength: 92 kg / cm2 Table 2 continued Attachment cast film, rolled film W70 / 46 brittle bad, brittle film; soluble in water, irregular moderate in the rolled structure; Tear strength: low W70 / 47 brittle bad, brittle film; soluble in water, irregular moderate in structure; Tear strength; - W70 / 50 not brittle, strong, parchment-like film; or brittle soluble in water, good setting speed in both directions; Tear strength: kg / cm2 Table 3 Determination of the foaming capacity 0.5% -500 ml (whip for 5 minutes) W 70/46 Liquid volume foam volume time 430 ml 300 ml 9.45 495 ml 195 ml 10.00 500 ml 130 ml 10.15 500 ml 100 ml 10.30 500 ml 80 ml 10.45 500 ml 30 ml 11.00 500 ml - 11.15 90 minutes Comparison: lauryl sulfate Liquid volume foam volume time 450 ml 420 mm 1 13.45 500 ml 350 ml at 14.00 500 ml 300 ml 14.15 500 ml 250 ml 14.30 500 ml 220 ml 14.45 500 ml 200 ml 15.00 500 ml! 150 ml 15.30 500 ml - 16.30 225 minutes Example 2 In a high-speed mixer, melted and dehydrated polyethylene glycol with a molecular weight of 25,000 (A) mixed with ricinoleic acid (B) and hexamethylene diisocyanate (C) in a weight ratio of 800: 50: 34 are continuously introduced and homogenized. The mixture is then fed to an extruder, which is heated to 130 to 150 ° C. and, with an approximate dwell time of 30 minutes, delivers a melt that is immediately poured into molds. When the material cools slowly, it solidifies into hard, horn-like substances that can be worked with mechanical means. They can be sawed, drilled and milled and thus modified as required. Particularly interesting areas of application are the production of petrol and mineral oil-resistant seals and plain bearings, the content of ricinoleic acid residues having a favorable lubricating effect.

Calendering produces a clear, supple, transparent, water-soluble, but petrol and grease-resistant film; their strength in the transverse direction is good, but there is perfect longitudinal orientation, with tear resistance of 224kg / cm 2 Instead of ricinoleic acid, z. B. oxystearic acid occur.

Of course, the above rule with regard to the quantitative proportions can be used largely modify the reactants in the sense of the description. Used to 800 parts of polyglycol 25,000 50 parts of ricinoleic acid and 38 parts of hexamethylene diisocyanate, then one obtains masses which are granulated on various crushing machines or can be ground. It turns out that no solubility whatsoever in known Solvents as well as in water. But swelling does occur occasionally on, so z. B. in water, alcohol, benzene, while compared to gasoline, ethyl acetate, Ethylene chloride, vegetable oils and mineral oils almost completely resistant is present.

This swelling capacity is used technically in various directions. The granulate can be used, for example, to seal boreholes in oil drilling to serve. The finely ground products have the property of being loose. porous To bring about the desired water retention in soils and in fuel tanks, for example to bind separated water.

Table 4 below illustrates the change in properties with the composition of the polyadducts.

Table 4 Approach no. 73/5 37/6 Parts moles parts moles parts moles Polyglycol 25000 800 0.032 800 0.032 50 0.002 Ricinoleic acid .............. 50 0.1677 50 0.1677 10 0.0336 Hexamethylene diisocyanate .......... 34 0.200 32 0.190 6 0.035 Table 5 Approach cast film rolled film W 73 / 'bad, slightly clear, supple, smooth, fragile films; water-soluble film; Strength in the horizontal good, in the longitudinal direction direction oriented; Tear strength: 224 kg / cm2 Table 5 continued Approach cast film rolled film W 73/8 bad, slightly cloudy, supple, smooth, fragile foils, parchment-like, water-soluble liche foil; greater strength in transverse direction, oriented lengthways; Tear strength: 213 kg / cm2 Example 3 In a stirred flask equipped with a reflux condenser, a mixture of 50 parts of polyethylene glycol (molecular weight 20,000) (A) and 10 parts of sebacic acid (B) is dissolved in 200 parts of anhydrous benzene, and 8.7 parts of hexamethylene diisocyanate (C) are gradually added. After the reaction has ended, impurities are filtered off and the solvent is distilled off.

An amorphous, white mass with SZ-0.5, VZ 48, OH-Z0 is obtained. the aqueous solution has a p-value of about 7 (10/0) and a viscosity of 3.36 cP. The melting point is 128 "C (Kofler).

Is used in the same way to 50 parts of the polyglycol instead of sebacic acid 1 part of a diamine, which is produced by reacting stearylamine with acrylonitrile and subsequent hydrogenation was obtained, and 2 parts of hexamethylene diisocyanate, this creates a horny mass with SZ 0, VZ 50, O H-Z 90, alkali number 0.36. The pH the 10/0 solution is 5.6, its viscosity is 2.85 cP.

Although insoluble in gasoline hydrocarbons, polyadducts can of the type described both during the reaction and after it Paraffin, mineral oil, petroleum jelly and the like can be processed. It can also be solids of various types, such as graphite, work in.

Furthermore, higher molecular carbohydrates and their derivatives, such as Starch or methyl cellulose can be incorporated into the polyadducts while still warm. the Products are used in a similar way to the uncut raw materials.

The products produced by way of example with the aid of sebacic acid are suitable in the form of their aqueous solution for finishing leather; before the usual brighteners on a wax basis, they have the advantage of being heat ironable without loss of gloss. she They are also used in cosmetics as thickeners and binders for hair setting agents.

Example 4 250 parts of polyglycol with a molecular weight of 20,000 (A), 10 Parts of polypropylene glycol of molecular weight 2000 (B) and 3 parts of tolylene diisocyanate (C) are in a stirred kettle at 140 to 1600C without the addition of solvents implemented. The end of the reaction can be recognized by the disappearance of the isocyanate reaction. In the heat, the viscous material, possibly with the application of pressure, easily emptied. A yellow-brown, tough product that is almost clearly soluble in water. The 100% solution has a viscosity of 90 cP, a 10/0 solution shows the viscosity of 1.71 cP.

If you add a 0.5% solution of this substance in alcohol to a water-containing one Add crude oil with stirring and leave to stand for 2 hours at 80 ° C, then total occurs Splitting of oil and water.

Example 5 300 kg of polyethylene glycol with a molecular weight are dissolved of about 30000 and 30kg one dimerized oleic acid with a molecular weight of about 600 in 600 l of xylene and circulates the volatile ones by heating on the reflux condenser Components from.

Then 0.5 kg of iron ethyl glycolate or 0.333 mol percent of dibutyl tiandilaurate is used as a catalyst and reacts with 10 kg of hexamethylene diisocyanate.

The implementation is already in about a minute due to a sharp increase in viscosity recognizable. The solution obtained in this way in xylene is already suitable as such to numerous uses. But you can also choose the reaction product isolate it by allowing the solvent to evaporate or by distilling off in vacuo. Due to the iron content, the product is brown in color and dissolves in a paste-like manner in water. Its viscosity in 50 /, The solution at 20 "C is about 4000 cP. It is a good emulsifier for oleic acid.

Claims (3)

PATENT CLAIMS: 1. Process for the production of high molecular weight water-soluble or water-swellable polyether urethanes, characterized in that that one is a mixture of A. a substantially linear polyethylene glycol or Adduct of ethylene oxide with low molecular weight polyhydric alcohols or polyglycols with a molecular weight of 7500 upwards, B. a compound with long, optionally carbon chain interrupted by ether bridges, the two functional with isocyanate Groups and a molecular weight of 200 to about 2000, C. one of the reactive Groups of the compounds A and B approximately equivalent amount of a diisocyanate of general formula R (NCO) 2 [R means an aliphatic, aromatic, hydroaromatic, araliphatic or heterocyclic radical, optionally with ether bridges (O, S) or further substituents], or its dimeric, polymeric or blocked ones Reacts modifications in the absence of water. 2. The method according to claim 1, characterized in that the reactant B in amounts of about 3 to 20 percent by weight based on reactants A, is applied. 3. The method according to claim 1 and 2, characterized in that the Reaction is carried out in the presence of an inert solvent. Documents considered: German Auslegeschrift No. 1,047,420; German patent application F 6215 IVb / 39c (published on December 17, 1953); British Patent No. 769 091; Austrian Patent No. 197,582; Belgian patent specification No. 548 886.