DE2633293C2 - - Google Patents

Description

The subject of German patent 25 50 796 is a ver drive to the "in situ" production of stable dispersions of polyisocyanate polyadducts in hydroxyl group-containing compounds as dispersants by reacting (1) organic polyisocyanates with (2) at least difunctional primary and / or secondary Compounds having a molecular group with amino groups weight from 60 to 10,000 and / or hydrazines a molecular weight of 32 to 500 and / or hydra ziden with a molecular weight of 90 to 10,000 and / or at least difunctional primary hydroxyl group-containing compounds with a molecular weight from 62 to 400 in (3) compounds having at least one hydroxyl group with a molecular weight of 62 to 16,000, the connections of Group (3) have secondary hydroxyl groups, if as Compounds of group (2) those with primary hydro xyl groups are used, the reaction component in the presence of 7 to 35% by weight of water, when using highly hydrophilic alcohols in the presence  from 4 to 35% by weight of water, based on the reaction mixture (including water), reacted and given if afterwards the water in a manner known per se away.

It was now in further training of the process of Main patents found that follow the main patent described general working method stable, fine Partial and relatively low viscosity dispersions from Um settlement products of organic polyisocyanates, aqueous ammonia and optionally certain amounts on other amino functional compounds of the Main patent referred to as component (2) in min Desten a compounds having a hydroxyl group can be produced as a dispersant. The so get Ten bis-ureas can then optionally by crosslinking with formaldehyde in high molecular poly methylene ureas are transferred. This poly too methylene ureas form fine, stable and low-viscosity dispersions in the as dispersant used, hydroxyl group-containing compound.

The present invention thus relates to further training of the process for "in situ" production provision of stable dispersions of polyisocyanate Polyaddition products in hydroxyl groups Compounds as dispersants by reacting

• (1) organic polyisocyanates with  
• (2) at least difunctional primary and / or second compounds containing amino groups a molecular weight of 60 to 10,000 and / or Hydrazines with a molecular weight of 32 to 500 and / or hydrazides with a molecular weight from 90 to 10,000 and / or at least difunktio bright primary hydroxyl-containing verbin with a molecular weight of 62 to 400 in
• (3) Ver at least one hydroxyl group bindings with a molecular weight of 62 to 16,000.

the compounds of group (3) secondary Hy possess hydroxyl groups, if as compounds of Group (2) those with primary hydroxyl groups are set, and wherein the reaction components in Presence of 7 to 35% by weight of water when used strongly hydrophilic alcohols in the presence of 4 to 35% by weight of water, based on the reaction mixture (a finally water), and if necessary closing the water in a manner known per se remotely, according to patent 25 50 796, characterized in that as component (2) an aqueous ammonia solution starts.

The invention further relates to further training of the method according to the invention, which be therein stand that

• - One as component (2) in addition to ammonia up to 50 mol%, based on the total amount of amino functional compounds, at least difunktio nelle primary and / or secondary amino groups pointing compounds with a molecular weight from 60 to 10,000 and / or hydrazines with one Molecular weight from 32 to 500 and / or hydrazides with a molecular weight of 90 to 10,000 puts,
• - The dispersant (component 3) before Polyaddition reaction an aqueous polymer latex clogs, and
• - one before, during or after the end of the polyaddi tion reaction to the reaction mixture formaldehyde adds.

The invention also relates to the use of Dispersion obtained according to the invention as a starting components for the production of homogeneous or cell shaped polyurethane plastics.

In the process according to the invention, as a component (2), as already mentioned, in addition to aqueous ammonia up to 50 mol%, based on the total amount of amino functional compounds, including hydrazine, hydrazides, so such as primary and / or secondary amino groups Connections are used as they are in the main patent be described in detail. In the invention  Processes are generally 0.5 to 1 mole of ammonia 1.5, preferably 0.9 to 1.2, particularly preferably 1 Equivalent to polyisocyanate used. Be next to Ammonia additional aminofunctional compound uses, so must also one of these amino functional compounds about an equivalent amount additional polyisocyanate can be used.

You get a comparatively urea shape an aqueous solution in a polyhydroxyl compound and then removes the water by distillation, so the urea crystallizes in coarse needles. A such suspension of urea crystals is as Starting component for the production of polyurethane plastics unusable.

According to a preferred variant of the invention Process are the "in situ" Disper sions of bis-ureas or tris-ureas with Formaldehyde in the presence of catalytic amounts of acids or alkali in a manner known per se, cf. e.g. B. DE-OS 23 24 134, cross-linked to polymethylene ureas. In general, 0.2 to 3 moles are used preferably 0.4 to 1.5 mol, particularly preferably 0.5 to 0.8 mol, formaldehyde per urea group equivalent.

According to the invention, it is also possible to use the formaldehyde to be used together with the ammonia solution. It ent are products with different physical properties shafts than in the above described verver  wetting with formaldehyde, namely disperse systems that have a microgel-like character. It is with this Vari ante of the method according to the invention make sure that all components either with are mixed together or that the polyisocyanate immediately after mixing formaldehyde and Ammonia solution in the dispersant in the reaction mixture is introduced, essentially before Have reacted ammonia and formaldehyde to urotropin.

Of course you can think of the Ver also drive a polyaddition reaction according to the main patent or connect according to DE-OS 25 50 797. Arise in this way dispersions of mixtures of various types Polyisocyanate polyadducts in polyhy droxyl compounds used for special purposes are particularly well suited.

According to a further variant of the Ver You can drive the properties of the inventions Polyurethane produced according to the invention plastics additionally in a technically advantageous manner modify by - expediently before the "in situ" - polyaddition reaction - as a dispersion medium serving polyhydroxy compound a polymer latex, for example an aqueous polyurethane dispersion or the aqueous solution of an ionic polyurethane, a polymer latex or a dispersion of a poly condensation product is added. The polymer latex or the solution generally has a solids content  from 1 to 60% by weight, preferably from 5 to 55% by weight, and is generally used in such quantities that the weight ratio between the solids of the poly merlatex and "in situ" bis-urea or Tris urea between 1:99 and 99: 1, preferably between 10:90 and 90:10, particularly preferably between 25: 75 and 75: 25.

In the variant of the invention described above According to the method, both cationic and anionic and nonionic polyurethane dispersions be used. Preferably according to the invention used such aqueous polyurethane dispersions, which when drying polyurethane foils with elasti properties. Among them are in particular rubber-elastic or at least impact-resistant poly urethanes or polyureas or polyhydrazodicarbo to understand amides that have a ball indentation hardness below 1400 kg / m³ (60 s according to DIN 53 456), preferably a Shore Hardness B of less than 55, particularly preferably one Shore A hardness of less than 98. For the later production of, for example, polyurethane Foams, elastomers or coatings with spec Of course, individual properties can be used Dispersions of harder polyurethanes are also used will.

Aqueous suitable for the process according to the invention Polyurethane dispersions can then be obtained on their own if, when manufacturing the polyurethane compo  are also used, which are ionic or Groups capable of ion formation and at least still an NCO group or at least one with isocyanate have group-reacting hydrogen atom.

A summary of the different ver drive for the production of polyurethane dispersions can be found e.g. B. D. Dieterich and H. Reiff "Die Applied Macromolecular Chemistry "26, 1972, pages 85 to 106, D. Dieterich et al in "Angewandte Chemie" 82, 1970, pages 53 to 63, and D. Dieterich et al. J. Oil Col. Chem. Assoc. 1970, 53, pages 363 to 379. In the A comprehensive literature will also be available in this collection given overview. Regarding the manufacture of cationic polyurethane dispersions are still on the DE-AS 11 84 946, 11 78 586, 11 79 363 and 12 70 276, the US-PS 36 86 108 and BE-PS 6 53 223, 6 58 026 and 6 36 799 pointed out.

Suitable anionic polyurethane dispersions for example in DE-AS 14 95 847, 15 70 656 and 17 20 639. More according to the invention setting ionic polyurethane dispersions for example in DE-OS 17 70 068, 19 53 345, 19 53 348 and 19 53 349, DE-AS 14 95 745, 12 82 926 and 16 94 129 and DE-OS 15 95 687, 16 94 148, 17 29 201 and 17 71 068. The production of Nonionic polyurethane suitable according to the invention Dispersions take place, for example, according to the method DE-OS 21 41 807, 23 14 512, 23 14 513 and 23 20 719.  

Suitable polymer latices are, for example, those based on natural rubber, Styrene-butadiene copolymers, neoprene, styrene-acrylic tril copolymers, polyethylenes, chlorosulfinated or chlorinated polyethylene, butadiene-acrylonitrile copoly mer, butadiene-acrylate copolymers, polyacrylic acid esters, PVC and possibly saponified Ethylene-vinyl acetate copolymers.

Examples of such polymer latices are e.g. B. the US-PS 29 39 013 or DE-OS 20 14 385 can be found.

As an example of polycondensate dispersions aminoplast optionally containing ion groups or phenol plastic dispersions mentioned in the DE-OS 23 24 135 are described.

According to a special embodiment of the present Invention can be first in a first stage Dispersing agents having hydroxyl groups contain the poly Prepare merisates or polycondensates directly "in situ" and then the polyadditions in the same reaction vessel reaction between polyisocyanates and ammonia and ge optionally further amino functional compounds let run.

As already mentioned, instead of an aqueous poly merdispersion in the process of the invention as Hydroxyl groups containing dispersants  Compound also aqueous dispersions of ionic or add nonionic polyurethanes, as in for example in the publication mentioned at the beginning by D. Dieterich et al. in "Angewandte Chemie", 82 1970, Pages 53 to 63.

According to the variant of the invention described above method (addition of aqueous polymer dispersions or of aqueous solutions of ionic polyurethanes) targeted property properties can be optimally Changes or improvements in the invention Polyure produced according to accessible dispersion Thankunststoffe by suitable choice of the starting connection achieve. Depending on the purpose of the the modified poly accessible according to the invention hydroxyl compounds producible polyurethanes and desired modification or improvement of your mecha properties or their applicability the different starting components of the invent method according to the invention. Would you like, for example a relatively hard, brittle polyurethane type impact resistant modify, use the aqueous dispersion a highly elastic polyurethane, polymer or Polycondensate. That way you can not only do that greatly reduce the general brittleness of the end product but also especially against repelling vulnerable marginal zones, for example one of them provided foam, elasticize.  

Of course, one can reverse the same Principle also a relatively soft polyurethane end product with the help of a dispersion of a relatively hard Polyurethane, polymer or polycondensation pro modify the product. It works that way, both Hardness and tensile strength of the end product too opti lubricate. In addition, you can also, for example, at the use of finely dispersed polyhydrazodicarbonamide Particles improve the light stability of the ver achieve driving products.

With the help of polyhy containing ionic polymers Droxyl compounds can be foams with ions create groups whose hydrophilicity is increased.

Such hydrophilized foams are e.g. B. easier wettable and can depend on the hydrophilic Character absorb larger amounts of water than conventional national products. You can e.g. B. also as Ionaus exchangers are used.

An interesting advantage of the Ver driving also lies in the fact that when using for example ionic polyisocyanate polyaddition pro products containing polyhydroxyl compounds in the Manufacture of polyester urethane foams on the otherwise necessary use of emulsifying agents can be dispensed with. Apparently they work in the reak ionic polyurethane moles introduced cool as an internal dispersant.  

For the rest, the disclosure of the main patent applies 25 50 796 in full for this one too Additional registration.

The following examples illustrate the invention Method. Unless otherwise noted, numbers are given indicated as parts by weight or as% by weight.  

example 1 20% aromatic bis-urea dispersion in one linear polyether

Recipe:
416 parts by weight of a linear propylene glycol, OH number 56 (hereinafter referred to as polyether I) as a dispersant;
68 parts by weight of 25% aqueous ammonia solution;
87 parts by weight of 80/20 mixture of 2,4- / 2,6-tolylene diisocyanate

Water content:
8.9 percent by weight

Operation and reaction conditions

In a boiler stirrer with a reflux condenser the dispersant and the aqueous ammonia solution Room temperature (18 to 25 ° C) submitted and the toluene Mix diisocyanate with stirring in the liquid phase the mixture is introduced directly so that the temperature  due to the exothermic polyaddition freak tion to 50 to 70 ° C. After the Tuesday Isocyanate can be added immediately with the distillation of the Water can be started under reduced pressure. The hot, water-free dispersion is passed through a 100 µ sieve drained.

The 20% dispersion has a viscosity of 25 ° C 1930 MPa · s, which does not change even with long storage changes.

Example 2 20% aromatic bis-urea dispersion in one linear polyether

Recipe:
1136 parts by weight of polyether I;
136 parts by weight of 25% aqueous ammonia solution;
56 parts by weight of water;

Water content:
10 percent by weight.

The reaction conditions are the same as in Example 1 specified. The fine 20% dispersion has 25 ° C a viscosity of 1960 mPa · s.

Example 2a 20.9% polymethylene urea dispersion in linear Polyether

Allowing to the bis-urea dispersion of Example 2, if necessary, even before distilling off the Water, such an amount of aqueous formalin solution, that for every 2 urea groups one formaldehyde molecule is present for one hour at 70 to 95 ° C in the presence a catalytic amount of 85% phosphoric acid act, you get a polymethylene urea dis persion, which is anhydrous at 25 ° C and a solid content of 20.9 (10)% a viscosity of 2860 (1680) mPa · s.

Example 3 20% aliphatic bis-urea dispersion in one linear polyether

Recipe:
808 parts by weight of polyether I;
136 parts by weight of 25% aqueous ammonia solution;
10 parts by weight of water;
168 parts by weight of 1,6-hexamethylene diisocyanate.

Water content:
10 percent by weight.

The dispersion is made after work example of example 1.

At 25 ° C the 20 (15, 10)% water-free dispersion a viscosity of 9800 (1750, 1040) mPa · s.

Example 4 20% aromatic bis-urea dispersion in mono Ethylene glycol

Recipe:
416 parts by weight of monoethylene glycol;
68 parts by weight of 25% aqueous ammonia solution;
87 parts by weight of 80/20 mixture of 2,4- / 2,6-tolylene diisocyanate

Water content:
8.9 percent by weight.

The dispersion is made after work example of 1. The viscosity of the anhydrous dispersion is as the following table shows very strong both from the solids content as well depending on the temperature.

Example 5 20% aromatic bis-urea dispersion in mono ethylene glycol

Example 2 is repeated, but using 1136 parts by weight of monoethylene glycol instead of poly ether I.

The viscosity of the fine-particle stable dispersion depending on the solids content at 25 ° C:  

Example 6 20% bis-urea-styrene-acrylonitrile dispersion in a linear polyether. Solid ratio 1: 1

Recipe:
1136 parts by weight of polyether I;
355 parts by weight of a 40% strength aqueous styrene-acrylonitrile dispersion (styrene: acrylonitrile weight ratio = 72:28), hereinafter referred to as "SAN latex";
68 parts by weight of a 25% strength aqueous ammonia solution;
125 parts by weight of 4,4'-diphenylmethane diisocyanate

Water content:
15.7 percent by weight.

Way of working

In a stirrer with a distillation attachment the dispersant, the SAN latex and the aqueous  Ammonia solution mixed at room temperature and that on Heated 4,4'-diphenylmethane diisocyanate at 80 to 100 ° C slowly introduced directly into the liquid template and if necessary with the help of a heat exchanger Reaction temperature brought to 60 to 70 ° C until none there is more evidence of free diisocyanate. The water is distilled off under reduced pressure.

The viscosity of the 20 (10)% water-free dispersion is 4200 (1680) mPas at 25 ° C.

Example 6a Polymethylene urea styrene acrylonitrile dispersion the dispersion of Example 6

The 20% solution described in Example 6 is added Dispersion, possibly even before water distillation, with that calculated on the urea groups equivalent amount of an aqueous formaldehyde solution and adds a catalytic amount of 85% phosphoric acid, so it takes 60 to 90 minutes at 70 to 100 ° C the condensation reaction to aromatic polymethylene urea.

The 20.3%, water-free, stable poly thus obtained methylene urea / styrene acrylonitrile dispersion has 25 ° C a viscosity of 4440 mPa · s.  

Example 7 20% bis-urea / acrylonitrile-butadiene-styrene dis persion in linear polyether, solids ratio 1: 1

The recipe and method of operation are identical to the example 6, however, 430 parts by weight of a 33% aqueous ABS dispersion (70% by weight styrene-acrylonitrile copolymer and 30% by weight of graft copolymer from polybutadiene, Styrene and acrylonitrile). The water content is 19.3% by weight.

The 20 (10)% dispersion has a viscosity at 25 ° C from 3480 (1450) mPas.

Example 8a 20.3% polymethylene urea / acrylonitrile butadiene Styrene dispersion

Condensed by polyisocyanate polyaddition resulting urea groups in the dispersion of Example 7 with formaldehyde according to the procedure of Example 6a gives a finely divided dispersion with a viscosity of 3610 mPa · s at 25 ° C.

Claims (6)

1. Further training of the method for "in situ" - production of stable dispersions of polyisocyanate polyadducts in compounds containing hydroxyl groups as dispersants by reaction of

• (1) organic polyisocyanates with
• (2) at least difunctional primary and / or secondary amino group-containing compounds with a molecular weight of 60 to 10,000 and / or hydrazines with a molecular weight of 32 to 500 and / or hydrazides with a molecular weight of 90 to 10,000 and / or at least difunctional compounds containing primary hydroxyl groups with a molecular weight of 62 to 400 in
• (3) at least one hydroxyl group-containing compound having a molecular weight of 62 to 16,000

the group (3) compounds being secondary Have hydroxyl groups, if as compounds of group (2) those with primary hydroxyl groups are used, and taking the reaction components in the presence of 7 to 35% by weight  Water, when using highly hydrophilic alcohols in the presence of 4 to 35 wt .-%, based on the Reaction mixture (including water) and if necessary then the water in on known way away, according to patent 25 50 796, characterized in that as com component (2) uses an aqueous ammonia solution. 2. Further development of the method according to claim 1, characterized in that component (2) in addition to ammonia up to 50 mol%, based on the Ge total amount of monofunctional compounds, min least difunctional primary and / or secondary Compounds containing amino groups with a Molecular weight from 60 to 10,000 and / or hydra zine with a molecular weight of 32 to 500 and / or hydrazides with a molecular weight of 90 to 10,000 uses. 3. Further training of the procedures according to the An sayings 1 and 2, characterized in that one the dispersant (component 3) before the poly addition reaction to an aqueous polymer latex puts. 4. Further training according to claims 1 and 3, characterized in that one before, during or after the polyaddition reaction has ended Reaction mixture formaldehyde is added.   5. Use obtained according to claims 1 to 4 dispersions as starting components for the Production of homogeneous or cellular poly urethane plastics.