DE1931055C3 - Process for the production of polyisocyanates with a biuret structure - Google Patents

Description

60 leads. _. _Λ,.

The strong increase in the space-time yields due to the catalysts used according to the invention and catalyst mixtures is particularly useful in the production of aliphatic, cycloaliphatic and araliphatic

65 phatic biuret polyisocyanates surprising. the

£ S3Ö3S £ 3 £ SSSSäSS

1951 055

compared to the reaction rate, which are mentioned at 7 21031, such as Ν, Ν-dimethylhydrazine

the implementation of the uncatalyzed Biuretherstel- N, N-bis- (ß- hydroxyaryl) -hydrazine, NN diethy

Development according to the hydrazine, Ν, Ν-diisopropylhydrazine, N-amine described in GB-PS 10 44 932

Procedure found w.rd. piperazine, N-AminomoφhoΊin, N-amino-N-methyl

The process according to the invention thus leads to 5 piperazine, Ν, Ν-diaminopiperazine and carbazine residues

the biuret polyisocyanate formation to technically special or carboxylic acid hydrazide derivatives of these above

ders advantageous space-time yields, which are in th hydrazine. Appropriate catalysts are far away

Case of Example 1 to about 600 to 640 g per liter of all hydrazinium salts of the aforementioned compounds

and hour yield, while the space-time yield with phosphoric acid, phosphorous acid, chlorine

with uncatalyzed reactions only approx. 126 g per io acetic acid, trichloroacetic acid, oxalic acid, ants

Liter and hour. The new process allows acid

hence an almost five-fold increase in space-time. As preferred catalysts are special

Yield in the production of Bmretpolyisocyana- highlighted: diethylammonium chloride, dimethyl

ten ζ. B. from hexamethylene diisocyanate and tert-butyl ammonium chloride, Ν, Ν-dimethylhydrazine rhine chloride

alcohol. .... »5 triethylammonium chloride, dimethylbenzylammo

The comparison between the two curves of the nium chloride.

Example 1 also shows the further *, considerable. Mixtures of the Kataiysa mentioned can also be used

Advantage of the faster decomposition of the tertiary butyl gates can be used, such as dimethylammonium

urethane in the final phase of the reaction, since the chloride and Ν, Ν-dimethylhydrazinium chloride (1: 1)

uncatalyzed biuret polyisocyanate production approx. ao diethylammonium chloride and N.N-Dimethylhvdra-

12 to 10% of the tertiary butyl urethanes according to curve II zinium chloride (1: 1), triethylammonium chloride 'and

disintegrate extremely slowly. The inventive Ν, Ν-Dimethylhydraziniumchlorid (1: 2), diethyl

The method therefore additionally allows an optimal ammonium chloride and N.N-diethylhydraziniumchlo ·

Utilization of the tertiary alcohol and rid (1: 2) used as well as mixtures of diethylaminonium

accordingly leads to increased yields of biuret a ₅ chloride, Ν, Ν-dimethylhydrazinium chloride and

polyisocyanates with increased NCO content. N.N-dimethylammonium formate.

Catalysts to be used in accordance with the invention are the aforementioned catalysts or catalyst parts exemplified: Mixtures can be solid or liquid as such

Hydrogen halide salts, preferably hydro form, the polyisocyanate-tert-butanol mixtures

chlorides of ammonia, primary, secondary, tertiary 3 ° normal or elevated temperature can be added

tiary, aliphatic, cycloaliphatic, araliphatic. But they can also be in solution, in particular

see, aromatic and heterocyclic bases, as in carbamic acid hydrolyzed in humid air

Ammonium chloride, methylammonium chloride, dichlorides are added. When using

methylammonium chloride, trimethylammonium chloride from partially hydrolyzed carbamic acid chlorides

Ride, ethylaminonium chloride, diethylammonium 3.5 can also refer to the use of amine hydrochloride

chloride, triethylammonium chloride, propylammo- rides can be omitted, as amine hydrochlorides through

nium chloride, n-butylammonium chloride, di-n-butyl hydrolysis of the corresponding carbamic acid chlorides

ammonium chloride, stearyl-methyl-ammonium chloride, are formed. As preferred to be used

Morpholine hydrochloride, piperidine hydrochloride, carbamic acid chlorides are mentioned:

N-methylmorpholine hydrochloride, caprolactimme- 40 Ν, Ν-dimethylcarbamic acid chloride, N, N-diethyI-

ethyl ether hydrochloride, imidazole hydrochloride, dicarbamic acid chloride, N-methylethyl carbamic acid

methylbenzylammonium chloride, the hydrochloride chloride, Ν, Ν-di-n-butyl-carbamic acid chloride, N-Me-

of polyamines such as of N.N'-Dimethyiäthylen- thylcarbamidsäurcchlorid, N-Äthylcarbamidsäure-

diamine, of amino alcohols, such as N-methyl diethanol chloride, N-cyclohexylcarbamic acid chloride, N-Ben-

amine, aminoethanol, diethanolamine, N-methylpro- 45 cykarbamic acid chloride or N-phenylcarbamide-

panolamin, the hydrochloride of the amidine derivative, acid chloride.

as they are hydrolyzed by the hydrogenation of cyanoethylated addition products of phosgene and

ε-caprolactam or pyrolidone- (2) are obtained, chloroformic acid esters on tertiary organic bases,

Hydrochloride of guanidine, hydrochloride of which as hydrolysis products are catalytically active

Isourea ethers. The salts 50 hydrochlorides of the corresponding organic bases may also be mentioned

all of the aforementioned nitrogen bases with phosphoric acid are also suitable. Also acetyl chloride,

phosphorous acid, chlorocressetic acid, trichloroacetic acid benzyl chloride, propionic acid chloride, benzoyl chloride,

acid, formic acid and oxalic acid. Benzyl chloride, benzotrichloride, trichloromethyl iso-

As particularly advantageous catalysts from the cyanide dichloride, bis-chloromethylcarbamidsäurechlo-

Series of hydrazine bases are: 55, rid, chloroformic acid methyl and ethyl ester, di-

__ The hydrochlorides of hydrazine, methylhydrazine, methyl sulfate can often be used with advantage in smaller sizes

Ethylhydrazine, propylhydrazine, n-butylhydrazine, quantity as a good solvent! for the invention

Ν, Ν'-Pimethylhydrazine, Ν, Ν'-Bishydroxyäthylhydra- according to the catalysts or Katahsator-

zin, the hydrochloride of the condensation products mixtures are used.

of acetaldehyde, isobutyraldehyde, acetone, benzine 60 The catalysts used according to the invention

aldehyde, cyclohexanone with hydrazine and substi- or catalyst mixtures are expedient-

hydrazines such as Ν, Ν-dimethylhydrazine or wise in proportions of 0.001 bi? 0.1 mole, preferably

Hydrazinecarbonsäureäthylcster, Semicarbazid, Thio- in proportions of 0.009 to 0.055 mol, based on

semicarbazide, carbazine ester and carboxylic acid hydra- applied tertiary alcohols are used. It is

zide as described in DT-PS 1184 947 and 1184 948 C5, it does not matter whether they belong to the tertiary alcohol, the

are scared. Hydrochloride is particularly valuable in applied diisocyanate or a mixture of

asymmetrically dialkyl-substituted hydrazines, i.e. tertiary alcohol and polyisocyanate, are added

1,1-disubstituted hydrazines, as described in BE-PS 'cn.

5 6

Because ζ. B. Mixtures of any polyisocyanates with the l-methyl - ^^ - diisocyanato-cyclohexane and 1-methyl for biurether production usual amounts of tert-butanol 2,6-diisocyanato-cyclohexane, bis- (4-isocyanato-cyclohexyl miscible at room temperature without exothermicity) drain methane, m- and p-xylylene diisocyanate, and Isosind reactions only about 70 ^c C phorondiisocyanat in measurable, mcthylsubstituieries hexamethylene scope, 5 effect the catalyst additives economies and pentamethylene and 2,6-Diisokeine reduction of the storage stability of such cyanalocapronsäureester.
Mixtures in kettles or tanks. Suitable aromatic diisocyanates are, for. B.

A Va- called with particular advantage:

The variant of the process according to the invention consists of 1-methylbenzoi-2,4-diisocyanate, 1-methylbenzene Concomitant use of NCO groups or carbio 2,6-diisocyanate, the technical toluylene diisocyanate amide acid chloride groups containing semicarbazide mixtures, m- and p-phenylene diisocyanate, naphthylene polyisocyanates as cocatalysts after the diisocyanai, diphenylmethane diisocyanate, di- and Information from BE-PS 7 21 031 are accessible. As a result, triisopropylbenzene diisocyanate, l- (Isocyanatophewird in the reaction according to the invention, a nyl) ethyl isocyanate, and also that caused by the additional Increase in the rate of reaction 15 different substituents such. B. alkoxy, nitro, and also an increased heat color stability of chlorine- or bromine-substituted diisocyanates. for the reaction approaches and the isolated biuret - the production of modified biuret types are also polyisocyanates in their technical application to suitable addition products of diisocyanates the field of the production of light-resistant lacquers, insufficient amounts of dihydroxyl compounds, Coatings or foams achieved. At the 20 like butanediol and neopentyl glycol. It can for Carrying out the reaction according to the invention, the biuret can also be formed by mixtures of different polymers such hydrazino isocyanates or their isocyanates are used. Also carbodiimide hydrochloride and carbamic acid chlorides in isolating groups are diphenylmethane diisocyanates ter form are added to the reaction mixtures; excellently suited for biuret formation, as z. B. however, they can also be produced in situ, 25 can be produced according to DT-PS 10 92 007, des by adding smaller amounts of hydrazine, methylhydrazine, further diiso-ethylhydrazine containing semicarbazide groups and preferably Ν, Ν-dimethylhydrazine cyanate of BE-PS 7 21 031 from asymmetrically disubden Seeds before or after the addition of the hydrazines according to the invention, which are excellent antioxidants applied catalysts added, heat color stabilizers and aging agents, these represent with the excess poly-30 protective agent.

Isocyanate to poly containing semicarbazide groups as preferred for biuret formation

isocyanates react. These preferred heat-coming aromatic diisocyanates are methyl

Stabilizers and cocatalysts are used in benzene-2,4-diisocyanate, l-methylbenzene-2,6-diiso-

Production of the biuret polyisocyanate is more appropriate cyanate and its technical isomer mixtures, such as

wisely in proportions of 0.023 to 0.3 Mo! and preferred mixtures of 80 to 65 parts by weight of 1-methyl

wisely in proportions from 0.04 to 0.? Mol, based on benzene-2,4-diisocyanate and 20 to 35 parts by weight

the diisocyanate used. It is i-methylbenzene-2,6-diisocyanate and 4,4'-dnso-

it also does not matter whether they name the tertiary butanol, cyanatodiphenylmethane,

the polyisocyanate or the finished mixture of In the process according to the invention

Polyisocyanate and tertiary butanol are added 4 ° at least 2.5 mol of a diisocyanate with one, mol

the. tertiary alcohol implemented. An optimal result

To carry out the process according to the invention, 6 to 10 mol of diisocyanate are used in the reaction

driving, those mentioned in GB-PS 10 44 932 per mole of tertiary alcohol are achieved. Using

tertiary alcohols, such as tert-butyl alcohol, 2-methyl, a very large excess of diisocyanate can

2-butanol, 2-methyl-2-pentanoI, 3-methyl-3-pentanol, 45 it may be desirable to use unreacted diisocyanai

3-Ethyl-3-pentanoI, _ l-methylcyclopentanol, 1-Me- from the biuret polyisocyanate formed by distillation

Separate ethylcyclohexanol, 1-ÄthylcycIohexanol, 1,1-dimethyl- or extraction. With a distillative

allyl alcohol suitable. The preferred alcohol is the use of a separator

tert-butyl alcohol. Thin film evaporator or a rotary evaporator

For the method according to the invention suitable 50 steamers. In the manufacture of polyurethane art

aliphatic, cycloaliphatic and araliphatic di- substances using solutions of biuret

isocyanates as starting materials are, for. B. tetra- polyisocyanates in monomeric diisocyanates are unnecessary

methylene diisocyanate, pentamethylene diisocyanate, of course, a separation of the diisocyanate

Hexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate excess.

nat, 1,4-cyclohexylene diisocyanate, 1,2-cyclohexylene- 55 In general, the biuret polyisocyanate

diisocyanate, hexahydroxylylene diisocyanate, 4,4'-di- formation via the formation of an unsaturated carbon

cyclohexyl diisocyanate, 1,2-di- (isocyanatomethyl) -cy- hydrogen, the evolution of carbon dioxide

clobutane, 1,3-bis (isocyanatopropoxy) -2,2-dimethyl- and via the intermediate stage of a urea diiso

propane, 1,3-bis (isocyanatopropyl) -2-methyl-2-propyl cyanate, from which then by reaction propane, l-methyl ^^ - diisocyanatocyciohexane, 1-Me- 60 with further diisocyanate the polyisocyanate mil

ethyl-2,6-diisocyanatocyclohexane, bis- (4-isocyanate · - biuret structure forms the developed carbon dioxide

cyclohexyl) methane, 1,4-diisocyanatocyclohexane and amount allows a control over the progress

1,3-diisocyanatocyclohexane, m- and p-xylylene ^; iso- the reaction.

cyanate, isophorone diisocyanate and 2,6-diisocyanato- The temperature for the inventive conversion caproic acid ester. Zung 65 must be between 60 and 21O ⁰ C. Preferi

Preferred aliphatic, cycloaliphatic and arali- is the temperature range from 150 to 190 ⁰ C. Di «

Phatic diisocyanates are: obtained polyisocyanates with a biuret structure

Hexamethylene diisocyanate, the mixture of isomers from the idealized formula

O C -NH-R-NCO

Il I

OCN - R - NH - C - N - R - NCO

in which R is an aliphatic, cycloaliphatic, araliphatic or aromatic radical, as obtained by removing the isocyanate groups from the diisocyanates mentioned can.

When exceeding the temperature of 19O ⁰ C excess diisocyanate may react to higher-functional isocyanates, which may be desirable in some cases with the hydrogen atoms of biuret.

The reaction is generally carried out without a solvent, but it can also be carried out in inert solvents such as dioxane, tetrahydrofuran, triethylene glycol diacetate, toluene, benzene, chlorobenzene, o-dichlorobenzene, Butyl acetate, ethylene glycol monoethyl ether acetate can be made.

In general, biuret polyisocyanate mixtures are solid or resinous bodies at room temperature or more or less viscous oils. They have a surprisingly high solubility in monomeric liquids or molten di- and polyisocyanates, such as tolylene diisocyanates or polynuclear polyisocyanates, such as 4,4'-diisocyanatodiphenylmethane, its technical isomers and carbodiimia groups containing liquid modification products, in Dicyclohexylmethane-4,4'-diisocyanate. Diphenyl-dimethylmethane-4,4'-diisocyanate, 4,6-Dimethyl-1,3-xylylene diisocyanate. Furthermore, there are the biuret polyisocyanates excellently compatible and miscible with a wide variety of isocyanate groups Adducts of diisocyanates with low molecular weight diols and triols such as glycol, trimethylolpropane, glycerine, likewise with polymerizing, low molecular weight polyisocyanates, which may contain several isocyanurate rings contained in the molecule.

45 to 50% biuret polyisocyanate solutions in monomeric diisocyanates provide z. B. in the case of the preferred polyisocyanates based on hexamethylene diisocyanate, toluene diisocyanates or of 4,4'-diisocyanatodiphenylmethane clear, storage-stable mixtures having a viscosity from 30 to 400 centipoise measured at 21 ⁰ C,. Also mixtures of liquid polyisocyanates technical obtained by phosgenation of aniline-formaldehyde condensates are relatively thinly viscous. In the case of using 65 to 70% solutions, viscosities of 1400 to 2000 centipoise, measured at 21 ° C, are found. Polyisocyanates with a biuret structure are valuable starting materials for the production and modification of plastics using the polyisocyanate polyaddition process, in particular for the production of lightfast lacquer coatings, foams, elastomers, coatings and impregnations. It is also possible to use biuret polyisocyanates for the production of semi-rigid and foam-molded polyurethane plastics with a compact surface and cellular core, surprisingly smooth, homogeneous and heat-resistant edge zones as well as cellular none being obtained.

example 1

In each case 37 parts by weight of tert-butyl alcohol are used mixed with 504 parts by weight of hexamethylene diisocyanate. For this purpose, 2.5 parts by weight of N, N-dimethylhydrazine are added added dropwise with rapid stirring. Among the solutions of this composition will be

a) 1.12 parts by weight of dimethylammonium chloride,

b) 1.2 parts by weight of Ν, Ν-dimethylhydrazinium chloride,

c) 1.52 parts by weight of diethylammonium chloride,

d) 2.28 parts by weight of di-n-butylammonium chloride,

e) 3.2 parts by weight of dimethylbenzylammonium chloride,

f) 1.8 parts by weight of morpholine hydrochloride,

g) 1.9 parts by weight of pipeline hydrochloride

given. Each of the reaction mixtures is heated to an internal temperature of 185 ° C. and determined released carbon dioxide and isobutylene with the help of a gas meter. In all experiments a) to £ the splitting off of gas and biuret polyisocyanate formation is over after approx. 40 to 50 minutes, and you get a reaction sequence which roughly corresponds to curve I Fig. 1, while the non-catalyzed ( Implementation by curve II in Fig. 1 is posed. The obtained biuret polyisocyanate solutions in monomeric hexamethylene diisocyanate possessed the following NCO values and viscosities:

a) 36.7% NCO 34 centipoise ^ rC,

60

b) 37.1% NCO

c) 36.3% NCO

d) 36.9% NCO

e) 37.2% NCO

f) 36.8% NCO

g) 37.4% NCO

33 centipoise / 21 ° C, 35 centipoise / 21 ° C, 34 centipoise / 21 ° C, 32 centipoise / 21 ° C, 34 centipoise / 21 ° C, 33 centipoise / 21 ° C.

709 617/11

10

Fig. 1

Biuret polyisocyanate form of hexamethylene diisocyanate and tcrt.-butanol at 185 ⁰ C curve I: reaction sequence in presence of the catalysts according to the invention curve II: Reaction Sequence for uncatalyzed reaction

FIG.

00 C.

-O-

240

response time in minutes

At approx. 96% conversion, the following space-time yields are obtained for the biuret polyisocyanate direction determined:

Space-time yield according to the process according to the invention: approx. 600 to 640 g per liter and hour.

Space-time yield with uncatalyzed reaction: approx. 126 g per liter and hour.

If, in experiments a) to g), excess hexamethylene diisocyanate is ^{removed at 130 °} C. and 0.2 torr in a thin-film evaporator, practically colorless biuret polyisocyanates with a high heat resistance (NCO content 20.5 to 21.5%). If the biuret polyisocyanate produced from experiment a) is baked into a highly crosslinked paint film in a few seconds with a polyester polyol made from phthalic anhydride and trimethylolpropane with an OH content of approx. 8.5% at a temperature of 230 ° C., a completely colorless paint film is obtained , while a comparatively produced paint film from biuret polyisocyanates produced by HCl or H ₂ SO ₄ catalysis or by uncatalyzed reaction is dark brown to reddish in color.

Example 2

Proceed exactly as in example 1, use! but as a catalyst a mixture of 0.3 weight share dimethylammonium chloride, 0.5 parts by weight of N-N-dimethylhydrazine chloride and 1.5 parts by weight of dimethylcarbamic acid chloride and performs the

Implementation at a temperature of 165 ⁰ C through.

Again, compared to the uncatalyzed comparison sample (cf. curve II, FIG. 2), there is a strong Accelerated tert-butyl urethane decomposition found, which is shown in curve I, Fig. 2, where again

a biuret polyisocyanate with high heat resistance is obtained. When stoved with polybydroxyl compounds, it produces practically colorless varnishes highest lightfastness and gloss retention

11 ~

Fig. 2

Biuret polyisocyanate formation from hexamethylene diisocyanate and tert-butanol at 165 ° C Curve I: the course of the reaction in the presence of the catalysts of the invention Curve 11: course of the reaction in the case of an uncatalyzed reaction

tert-butanol decomposition

Biuret formation

ο C

The biuret polyisocyanate prepared by the process of this invention as a binder enthi stoved at 230 ⁰ C stoving lacquers are colorless, while such coatings, the catalyst without notified biuret polyisocyanate containing discolored after baking brownish to reddish.

«F

Example 3

The procedure is as in Example 2, except that 37 parts by weight of tert-butyl alcohol are used as polyocyanates and catalyst mixtures:

a) 666 parts by weight of isophorone diisocyanate, 1.8 parts by weight Triethylammonium chloride, 1 part by weight of ethylhydrazinium chloride,

b) 666 parts by weight of isophorone diisocyanate, 78 parts by weight of a polyisocyanate prepared according to BE-PS 7 21 031 from 1 mole of N ₁ N-dimethylhydrazine and 2 moles of hexa-methylene diisocyanate and 1.8 parts by weight of diethylammonium hydrochloride, 0.5 part by weight of triethylammonium formate,

c) 564 parts by weight of m-xylylene diisocyanate, 1.9 parts by weight Hydrazinocarboxylic acid ethyl ester hydrochloride, 1.8 parts by weight of N, N-bis (/ f-hydroxyethyl) hydrazinium chloride,

d) 564 parts by weight of m-xylylene diisocyanate, 1.5 parts by weight n-butylammonium chloride, 0.9 parts by weight the salt of dimethylamine and phosphorous acid,

e) 540 parts by weight of l-methyl-2,4-diisocyanatocyclohexane, 2.1 parts by weight of hydrazinium chloride, 1.8 parts by weight of the oxalate from N, N'-diaminopiperazine, 0.4 parts by weight of the carbamic acid chloride from 1 mole of hexamethylene diisocyanate and 2 moles of hydrogen chloride,

f) 540 parts by weight of 1-methyl-2,4-diisocyanatocyclohexane, 0.4 part by weight of triethylammonium chloride, dissolved in 2 parts by weight of benzoyl chloride,

g) 498 parts by weight of 1,2-di- (isocyanatomethyl) -cyclobutane, 3 parts by weight of dimethylcarbamic acid chloride with a content of 8% dimethylammonium chloride and 5% phosgene,

h) 504 parts by weight of hexamethylene diisocyanate, 1.5 parts by weight of dimethylammonium chloride, 6 parts by weight of N, N-dimethylhydrazine,

i) 504 parts by weight of hexamethylene diisocyanate, ^ao 72 parts by weight of a polyisocyanate from 1 mole of Ν, Ν-dimet..ylhydrazine and 2 moles of hexamethylene diisocyanate, 1.4 parts by weight of dimethylammonium chloride.

The speed of the reactions is determined based on the amount of CO _{2 and isobutylene developed.} Based fractionated on a 96% sales z \ i biuret polyisocyanates found the following response times:

attempt Reaction time at 165 ° C
in minutes; inventive
proper catalysts Uncataly-
sated
reaction a 184 375 b 175 375 C. 169 345 d 180 345 e 190 360 f 185 360 G 182 364 H 168 360 i 165 360 Example 4

The procedure described in Example la) is followed, but the reaction is carried out at 140 ° C. and used as diisocyanate 522 parts by weight of technical grade toluene diisocyanate, consisting of 80% 1-methylbenzo! -2,4-diisocyanate and 20 "" 1-methylbenzene The catalyst used is a mixture of 1.2 parts by weight of dimethylammonium chloride and parts by weight of carbamic acid chloride from moles of hydrogen chloride and one mole of diisocyanate from 1 mole of Ν, Ν-dimethylhydric zine and 2 moles of hexamethylene diisocyanate an approximately 50% solution of biuret polyisocyanates having an NCO value of 37.1 ^r and a viscosity of 123 centipoise, precisely measured at 20 ⁰ C. the polyisocyanate mixture is wasserhel has an increased Wärniefarbbeständigkeit and ncij in the production of less Schaurnstoifcn Core discoloration as comparable, uncatalyzed biuret polyisocyanates The acceleration of the biuret polyisocyanate formation can be seen from curve I, Fig. 3. Curve Run II, Fig.: corresponds to the uncatalyzed reaction.

Formation of yisocyanate from tolylene diisocyanates and tert-butanol at 140 ° C
Course of the reaction in the presence of the catalysts of the invention
Course of the reaction in the case of an uncatalyzed reaction

= % tert-butanol decomposition = # biuret formation

Curve II gives a clear picture of the slow, uncatalyzed decay of the tertiary Butyl urethanes in the final phase of the reaction.

Example 5

The procedure is as described in Example 4, but the reaction is carried out at 160 ^° C. and 750 parts by weight of 4,4'-diisocyanatodiphenylmethane, 72 parts by weight of a polyisocyanate composed of 1 mole of N, N-dimethylhydrazine and 2 moles of hexamethylene diisocyanate, 2 parts by weight of dimethylcarbamic acid chloride with a Content of 0.8 parts by weight of dimethylamine chlorohydrate. With an approx. 96% conversion to biuret polyisocyanates, the following reduced reaction times are found in the catalyzed reaction:

attempt

Response time in
Minutes at 160 ° C and 95%
sales volume

According to example 5
Uncatalyzed

95

150

ίο The approx. 50% biuret polyisocyanate solutions obtained have a significantly higher comparison sample compared to the uncatalyzed comparison sample Heat color fastness and less tendency to yellow. Polyurethane foams made from them

is and polyurethane customers have increased light resistance and heat color fastness.

For this purpose 3 sheets of drawings

Claims (6)

Ll lightfast polyurethane of the highest lightfastness, t and excellent patent claims: oTnAaUuTe "" Man "; 7häTn> olyisocyanate with Biuret- <SrukSr by reacting any polyisocyanates for water-releasing compounds, ter- 1. Process for the production of Polyiso- nut ^ rJ? / j _{such as} tert-butanol, H ₂ S, formic acid, cyanates with a biuret structure by reaction, by hydrogenating polyadditions of polyvon diisocyanates, catalysts and up to ¹ ^ "" ^u , nitro compounds in the presence of 0.4 mol of a monohydric tertiary alcohol per ™ "£ ° _{th Their} formation extends over the moles of diisocyanate, optionally in the presence of 10 W ⁰ ^ J _{tf ines urine} toffdiisocyanates, having at welvon isocyanate adducts J ^ MStme diisocyanate over the Wasserstoffbeliebiger isocyanates with hydrazine or hydrazine. * L. urea groups attaches in the case of derivatives at 60 to 210 and ⁰ C, dadurchgekenn- "f ™ ° JJ f _ter t.-butanol as Reaktionskompoz calibration et η, that the reaction in the opposite ^Ve ™ ^e 7 ° |.? _{as in} ^ GB-PS 10 44 932 described war of salts or salt mixtures from nitrogen-15 Pf ™ "* _the disadvantage that relatively high Temperahaldgen bases and inorganic and / or organic vene <u 205 ° C for a sufficiently rapid niche acids in one Concentration of 0.001 ? ™ J: £ nine of the response are necessary. Aims to 0.1MoI per mole of tertiary alcohol than ⁰ ^ ₆ J of _the technical implementation of the reaction using catalysts. ^ ^ Space-time yield ^ an ^ by reaction * - 2. The method according to claim 1, characterized in that ¹ * ^ΠΙ ί! ^! ⁶ ? _α1ι ^ν _Γ ? ^Ι1 _{<ΐΐΓηκ1ιΙ} sufficient heat color Draws that one ^weraen the reaction in the presence of>'°' _{d Rea} ktionsansätze often discolored tertiary butyl alcohol performs. S browned polyisocyanates. Besides, the 3. The method according to claim 1 and 2, characterized in 5 ^^^^^ S ^ J ^ JZ that the reaction in counter? "^ ' ^R _{such as} . B. hydrochloric acid or Schwewart of mixtures of Ν, Ν -D.methylhydraz.n- f'S " ^8e ^ ^ie _K ^Z _atalysa toren produced biuret polyhydrochloride and dimethylamine hydrochlond ^^ _s S? BLibg« etit. carries out. ^ has _{now been found surprisingly} , it is at j ^ jj t rW Production of polyisocyanates with biuret 4. The method according to claim 1 and 2 characterized * gj £% diisocyanates and tertiary alcohols characterized in that the reaction in structure from ui »* Disadvantages to be eliminated, the presence of mixtures of NN-dimethyl possible. * ^ gjojen ^ Nac ^ _Saizen ^ hydrazine hydrochloride and diethylam.n-hydro- ™ ^^^ nitrogenous bases and anorchloride. 35 ^ g ^ _{or organic acids} as catalysts 5. The method according to claim 1 to 4, carried out ^ wirxL ^ J ^ J ^ Z ^ Z ^ characterized in that the reaction mt ^ "S ^ ₁ JKi μ hytocin or hydrazinine liquid carbamic acid chlorides or poly J ¹ ^ f ^r _d JSührte VerfJhren allows Hercarbamidsäurechloriden dissolved salt mixtures ₄ o tojvate β ^^, ^ Λ ^ Biuretpolyisodurchführt. ^"1 I Raum.zeit _in yields which far the 6. The method according to claim 1 to 5, characterized in that ^ SSJ ^^^^ äS £ Ä3 ffiSSSS vt ^ß 5 £ S OÄÄ 45 SärrÄo. ° e ^C n ^ya by the 3- to make amount of diisocyanate on addition products from 2MoI « ^b _G « ^ · _Invention is a process for monomeric .D »socyanate and 1 mole of N ₁ N-Di- ^ ™ _{on polyis} oc _y anates with the biuret structure methylhydrazine. S conversion of diisocyanates, catalysts 50 and up to 0.4 mol of a monovalent tertiary alcohol per mol of diisocyanate, having optionally in the presence of isocyanate adducts any isocyanates with hydrazine or hydrazine derivatives at 60 to 21O ⁰ C, characterized in 55 that the reaction in the presence of salts or salt mixtures from nitrogenous bases and inorganic and / or organic acids in a concentration of 0.001 to 0.1 mol per mole of tertiary alcohol as catalysts