DE2524476A1 - AROMATIC URETDIONE DIISOCYANATE DISULPHONIC ACIDS A PROCESS FOR THEIR MANUFACTURING AND USE - Google Patents

Description

Bayer Aktiengesellschaft 252U76

Central area of patents, trademarks and licenses

Wr / Hg 509 Leverkusen, Bayerwerk

* .''— üürij \ άι.)

Aromatic uretdione diisocyanate disulfonic acids, a process for their preparation and their use.

The present invention relates to new aromatic uretdione diisocyanate disulfonic acids, a process for their production and their use as a structural component in production of polyurethane plastics.

Aromatic diisocyanates with sulfonic acid groups are known (DT-OS 1 939 911). By reaction of toluene diisocyanate and sulfur trioxide, for example, a crystallized high-melting product is obtained which is dissolved in sodium hydroxide solution dissolves with rapid reaction and which can be used, for example, for the production of anionic PU dispersions. From DT-OS 2 227 111 it is also known that sulfonic acid and / or polyisocyanates containing sulfonate groups which, in addition to other reaction products, also contain uretdione derivatives have, can be obtained by sulfonating liquid multicomponent mixtures of aromatic polyisocyanates (cf. also DT-OSS 2 359 614 and 2 359 615).

It has now been found that novel aromatic 4-ring uretdione diisocyanate disulfonic acids can be obtained the general formula

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OCr

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NCO

in which

FL, R ₀ , Rj, R ,, R ₁ - and R _{c are} hydrogen, chlorine or

Represents a bromine atom, a methyl, ethyl or C ₁ -C, alkoxy group,

χ stands for -0 -,> C = O, ^ SO ₂ , R ₇ -CR ₈ or -CH = CH ^, where

R _{7 and} Rg denotes a hydrogen atom, a methyl, ethyl or, together with the carbon atom, a cyclohexyl group, and
η means 0 or 1,

obtained as a crystallized powder when solid diisocyanates of the general formula

NCO

in which

R., Rp, FU, FL, Rc »Rg» η and χ have the meaning given above,

sulfonated with sulfur trioxide in anhydrous opposite SO ^ and isocyanate inert solvent in the temperature range from -50 ⁰ C to '+ 100 ⁰ C.

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The present invention accordingly relates to the new uretdione diisocyanate disulfonic acids mentioned.

The present invention also provides a process for the preparation of these new compounds, which thereby is characterized in that a diisocyanate of the formula

\ in which ^R 5 ^R 2. / ^R 6 \ \ /
^R 3 ^ 1 ' ^R 2' ^R 3 ' ^R 4' ^R 5 '
Have meaning Rg, η and x

inert solvents in the temperature range from -30 ⁰ C to + is reacted with sulfur trioxide in anhydrous, to SO, and isocyanate groups 10O ⁰ C.

Finally, the present invention also relates to the use of the new uretdione diisocyanate disulfonic acids mentioned as a reactant for compounds containing isocyanate-reactive groups in the production of polyurethane plastics by the known isocyanate polyaddition process.

It is extremely surprising that the invention Method the uretdione formation takes place quantitatively in the acidic medium under sulfonation conditions, since the hitherto known isocyanate dimerizations according to literature (High Polymers, Vol. XVI, "Polyurethanes, Chemistry and Technology", written by Saunders-Frisch, Interscience Publishers, New York,

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London, Volume I, 1962, page 91) under basic reaction conditions or specific phosphine catalysis walk. It is also noteworthy that starting from diisocyanates, a uretdione ring was defined Form diisocyanate disulphonic acids and not higher molecular weight polyurethane diones such as those from corresponding diisocyanates arise under Phosphinkatalyae. As from NMR spectroscopic Investigations (see. Examples) shows, the sulfonic acid groups are in the compounds according to the invention exclusively in the ortho position to the NCO groups, the uretdione group in the products according to the invention form. As a result, only two of the four aromatic nuclei present are selectively sulfonated. Overall, the process according to the invention is surprising, since simultaneous selective sulfonation takes place in one reaction stage an -einernder two aromatic nuclei and selective Dimerization of the neighboring NCO group take place.

From DT-OS 2 227 111 it was already known that in the partial sulfonation of liquid aromatic polyisocyanates to liquid, unspecified liquid polyisocyanates containing sulfo acid groups, also uretdione groups which can be seen in the IR spectrum.

However, it could not be deduced from this that in the stoichiometric sulfonation of a 4,4'-diisocyanate-2-nucleus arcuate a defined uretdione sulfonic acid is formed.

Strikingly, even in the sulfonation of 4,4'-diisocyanatodiphenylmethane, a compound which is known to have two NCO groups of identical and pronounced reactivity contains, practically exclusively, the mono-uretdione-disulfonic acid found. The thermodynamically possible in itself

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Dimerization of a sulfonated diisocyanate with a non-sulfonated diisocyanate does not occur. The second, an aromatic nucleus bearing an NCO group, is neither sulfonated nor dimerized.

The sulfonation can be carried out with SCU or with organic compounds, in which S (X is additively bound, excluding water. The SO can be carried out in liquid - Or in gaseous, z. B. be used form diluted with nitrogen.

As organic compounds in which SO, additively bound are preferably pyridine-SO ,, dioxane-SO ·, -Tetrahydrofuran-SO ,, Ether-SO, called »Dimethylformamide-SO. However, preference is given to sulfonation with gaseous, in a stream of nitrogen diluted SO.

Starting compounds for the process according to the invention. are also the isocyanates of the formula

OCN — ίί Λ V- (xK / ΓΛ \ NCO

in which

R., R ₂ , R ,, R, _r Rf. T Rg, η and χ have the meanings given above .

Preferred starting compounds are diisocyanates of the formula mentioned, in which R and R, for hydrogen or a methyl group, R ₀ , R-., R _K and R _- , for hydrogen, x for a methylene bridge and η for 1.

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Examples of such diisocyanates are 4,4'-diisocyanatodiphenyl ^{methane, 3,3 f} - and 2,2'-dimethyl-4,4'-diisocyanatodiphenyl methane, 2,5,2 », 5'-tetramethyl-4,4 ^f -diisocyanatodiphenyl methane , 3,3'-dimethoxy-4,4'-diisocyanato-diphenylmethane, 3,3'-dichloro-4,4 ^I -diisocyanato-diphenylmethane, 4,4'-diisocyanato-dimethylmethane, 4,4'-diisocyanato-diphenylcyclohexylmethane , 4,4'-diisocyanato-benzophenone, 4,4'-diisocyanato-diphenylsulfone, 4,4'-diisocyanato-diphenyl ether, 4,4'-diisocyanato-3,3'-dibromo-diphenylmethane, 4,4'-diisocyanato -3,3'-diethyl-diphenylmethane, 4,4'-diisocyanatodiphenyl-ethylene- (1,2).

The solvents in question must be chemically inert both to SO and to the diisocyanates under the reaction conditions. Halogenated are preferred or nitrated hydrocarbons, such as. B. dichloroethane, tetrachloroethane, methylene chloride, chloroform, fluorotrichloromethane, Nitromathan, nitrobenzene or ethers, such as. B. Dioxane, THF or pyridine or sulfur dioxide.

The reaction is preferably carried out in a molar ratio of diisocyanate / SO, such as about 1: 1 to 1: 1.4. One can also a higher excess of SO, use without the course of the reaction changes significantly. It is also possible to work with a deficit of SO and the unreacted diisocyanate recover or recycle in the case of a continuous process.

The inventive process is carried out at temperatures between -3o C and + 1oo C, preferably -1o C and + 3o C, more preferably -5 ⁰ C and + 1o ° C. In this case, the diisocyanate is preferably placed in anhydrous solvents and the SO, which has evaporated in a nitrogen stream, is passed onto the surface of the well-stirred mixture, the

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Temperature preferably by cooling within the specified preferred ranges is kept. The uretdiones according to the invention fall as white or pink colored, in organic Solvent-insoluble, solid and preferably powdery crystalline products. They generally own no melting point and go smoothly into solution in dilute lye with decomposition. Also by uniting one Solution of the starting diisocyanate and a solution of SO or its adducts, the sulfonation can be accomplished will.

The remaining mother liquors can be used for further reactions can be reused.

As diisocyanates, the new substances react, as expected, at elevated temperatures, according to the known diisocyanate polyaddition process, with z. B. glycols, polyamines, higher molecular weight polyols such. B. polyethers or polyesters, to the corresponding polyurethanes or polyureas or polyurethane polyureas. By being present one sulfonic acid group per mole of diisocyanate used Isocyanato-uretdiones are practically completely non-toxic products, which are also built up from them when they are broken down Polymers again non-toxic substances (aminosulfonic acids) deliver. Furthermore, the products have no measurable vapor pressure. The isocyanato uretdiones according to the invention are thus versatile as physiologically sound diisocyanates, z. B. as an assembly unit in the frame of the diisocyanate polyaddition process, as a crosslinker, for Production of polyisocyanurates ^ poly arbodiimides, polyimides or polyhydantoins. As a result of their strongly polar or ionic character, the uretdione diisocyanates according to the present invention are particularly suitable for synthesis water-soluble or water-dispersible polyurethanes and Polyurethane ureas.

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The uretdione diisocyanates are suitable both as such and in the form of their reaction products, for example for production of binders and impregnating agents, especially for inorganic or mineral substrates, as well as for Construction of physically cross-linked ionomers, as well as cation exchangers and membranes. Furthermore, by mixing of the uretdione diisocyanates according to the invention with compounds containing HO groups, storage-stable plastisols that cure at temperatures above 100 ° C.

example 1

500 g (2 mol) of 4,4'-diisocyanatodiphenylmethane are in 1ooo ml of 1,2-dichloroethane dissolved. On the surface of this

vigorously stirred solution becomes a SO, /

Nitrogen stream supplied, which is obtained by evaporation at 13o c of 1o1 ml (2.4 mol) of freshly distilled SO-, in a nitrogen stream. The amount of nitrogen is regulated so that SO no more escapes from the reaction vessel. Stirring is continued until the reaction mixture has warmed to room temperature, after which it is suctioned off. 47o g (yield: 71 % of theory) of the uretdione are obtained

OCN

as a pink colored powder. Mp.> 28o C under decomp. Analysis: C 96 E% N 96 0% S% calculated: 54.5 3, ο 8.5 24.3 9.7 found: 53.8 3.4 8.6. 23.9 1o, 1

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IR spectrum: 2275 cm '"(intense) -NCO band

1790 era (intense and broad) uretdione band 118o cm "" ¹ (broad) SO H band

--1
The IR band at 1790 cm proves the presence of an SO ^ H group in the ortho position to the uretdione group, since the uretdione band in uretdiones unsubstituted in the ortho position is normally around 1765 cm. The stated constitution was also confirmed by NMR spectroscopic investigations: by treatment with deuterated dilute lye, the reaction product dissolves with evolution of CO 2. The sulfanilic acid derivative formed under these conditions has a characteristic aromatic proton resonance spectrum between 6.75 and 7.50 ppm for structures containing 1,2,4-thiisubstituted benzene rings. The ratio between aromatic protons and aliphatic -CHp protons determined by integrating the signals is 7/2. It has thus been proven that the —SO, H substituents are in the ortho position to the uretdione group and that only 1 nucleus of the starting diisocyanate has been sulfonated in each case.

example 2

69.5 g (1/4 mol) of 3,3'-dimethyl-4,4'-diisocyanato-diphenylmethane are dissolved in 3oo ml of 1,2-dichloroethane analogously to that in Example 1 given procedure with 11 ml (^ 1/4 mol) SO implemented. The uretdione derivative is obtained

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as a pink colored powder; Yield: 50 % of theory; Mp. Y 28o ° C with decomp.

Analysis: C% ti% N% 0 %

calculated: 57, ο 3.9 7.8 22.3

found: 56.2 4.2 7.2 22.6

S % 9, ο 9.5

IR spectrum: 2280 cm "" ¹ (intense) -NCO band

") Uretdione band

1770 "cm" ¹ (1185 cm

-1

-SO ^ H band.

-1

The location of the uretdione band at 1770 cm corresponds very well the shift of the uretdione band discussed in Example 1 by the ortho sulfonic acid group, where im here present case this band shift by the also present ortho methyl group is partially compensated.

NMR spectrum: signals between 6.80 and 7.60 ppm: aromatic

Protons;

Integration: 5 proton signal at 3.60 ppm: CHp group;

Integration: 2 protons signal at 2.10 ppm: CH, groups;

Integration: 6 protons

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Example 3

Following the same procedure described in Example 1, 69.5 g (1/4 mol) of 4,4'-diisocyanato-dimethyl-diphenylmethane are obtained dissolved in 3oo ml of 1,2-dichloroethane with 14 ml (0.33 mol) SO, sulfonated. The precipitated white powder represents the uretdione derivative

OCN

dar; Yield: 33 % of theory; Mp. ^ 285 ° C with decomposition. When the solvent is concentrated, a solid residue is left which consists of the Auagang diisocyanate and further uretdione derivative.

Example 4

126 g (1/2 mol) 4,4'-diisocyanatodiphenyl ether are reacted in 4oo ml 1,2-dichloroethane according to the procedure given in Example 1 with 21 ml (1/2 hol) SO at 50 ° C. (.. Y mp 28o C under decomposition), the precipitated partly light yellow colored powder, and the residue after the evaporation-dichloroethane consist predominantly of the uretdione-L \ "_ IVAT:

OCN

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Example 5

According to the same procedure described in Example 1, but at 25-3o ° C., 80 g (1/4 mol) of 3,3 ^f -dichloro-4,4'-diisocyanato-diphenylmethane in 300 ml of 1,2-dichloroethane are added 11 ml of freshly distilled SO treated. After concentration of the solvent, the desired uretdione derivative becomes

of mp y 28o ° C with decomp. won.

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Claims (4)

252U76 Claims _i 1 J Aromatic uretdione diisocyanate disulfonic acids of the formula OCN- in which R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R _{6 represent} a hydrogen, chlorine or bromine atom, a methyl, ethyl or C ₁ -C, alkoxy group, χ stands for -0-,> C = 0, -SO ₂ , R ₇ -CR ₈ or -CH = CH-, where R ₇ and Rg stand for a hydrogen atom, a methyl, ethyl or together with the carbon atom for a cyclohexyl group,
and
η means 0 or 1. 2. Process for the preparation of aromatic uretdione diisocyanate disulfonic acids according to claim 1, characterized in that a diisocyanate of the formula “CO Le A 16 448 - 13 - 609852/0983 252U76 in which R ₁ , R, R- ,, R ^, Rc, Rg, η and χ have the meaning given in claim, is reacted with sulfur trioxide in anhydrous, to SO, and isocyanate inert solvents in the temperature range of "30 ⁰ C to +100 ⁰ C. 3. The method according to claim 2, characterized in that the reaction with diluted by inert gas gaseous SO takes place. 4. Use of uretdione diisocyanate disulfonic acids according to claim 1 as a reactant for isocyanate-reactive groups Compounds in the production of polyurethane plastics by the known isocyanate polyaddition process. Le A 16 448 - 14 - 609852/0983