CA1082398A - Polyurethanes produced from diaminodiphenyl-dithioethers - Google Patents

Abstract

POLYURETHANES PRODUCED FROM
DIAMINODIPHENYL-DITHIOETHERS
Abstract of the Disclosure This invention relates to polyurethane elastomers produced using optionally substituted diaminodiphenyl-dithio-ethers as chain extenders. More particularly, this invention relates to certain polyurethane elastomers and a process for making such elastomers. The process broadly comprises reacting polyisocyanates with active hydrogen containing compounds with certain novel chain extenders of the general formula:

wherein R' and R", which may be the same or different, each represent hydrogen, an alkyl radical having from 1 to 6 carbon atoms, an aryl radical having from 6 to 15 carbon atoms, a cycloalkyl radical having from 4 to 12 carbon atoms, halogen, -NO2, -CN, OR''' or the radical

Description

~2398 Mo-1594-B
LeA 16,262 :
POLYURETHANES PRODUCED FROM
DIAMINODIPHENYL-D~TKIOETHERS

~ Background o~ the Invention - It is known that aromatic diamines may be used as chain extenders in the production of polyurethanes. In order to guarantee reasonable processing times, the generally used reactive aromatic isocyanates are reacted with s~owly reacting diamines. Slowly reacting diamines which have proved to be particularly effective are aromatic diamines of the type whose basicity and, hence, reactivity with respect to isocyanates, has been reduced by the introduction of halogen or carboxy sub-stituents. 3,3'-dichloro-4,4'-diaminodiphenyl methane (MOCA), ;
, ~:
which is often used, is mentioned as an example. However, the main disadvantage of this compound is its toxicity. In U.S.
Patent 3,823,833, 2,2'- or 4,4'-diaminodiphenyl sulphide is used -`
as chain extender in the production of polyurethane systems.
~` Howsver, the disadvantage of compounds of this type is the `~
.,j ,, susceptibility of the S-S-group in the polyurethane segment to ~i splitting by reduction or oxidation. Also short pot lives and - ~ 20 long in-mold times during the reaction with polyisocyanates ~ ~

; prevent economic processing. i ;
:~, ",- :~
Japanese Patent Application 9195/70 (as laid open) ~ I

; describes a concentrated polyurethane solution which may be ~' used for the production of fibers, films or artificial leather. ;~
~, ; 25 The chain extender used is a diamine corresponding to the general formula: NH2-R-(SR)n-NH2, ~herein R represents an aliphatic, `~
aromatic, alicyclic or heterocyclic group, and n = 1 or 2.

, The main disadvantage of a system extended with :: ~
diamines of this type is that it i5 necessary, because of the excessive reactivity of the amino groups with isocyanates, to use an organic solvent which considerably increases costs, ~ ;

LeA 16,262 .... . .. . . . . . .. . ..

-`` 101!~2;~9~

necessitates additional extraction systems and also involves the risk of fire and explosion.

An object of the present invention is to obviate the above-mentioned disadvantages of conventional diamine chain extenders, such as toxicity and the tendency of the S-S-group to be split by reduction or oxidation. An additional object is to provide polyurethane elastomers which have the advantage of solvent-free processing, relatively long pot lives and fairly short in-mold times.

-~ 10 These objects may be achieved by the use of certain diamines made available in accordance with the present invention.
:.., Description of the Invention The present invention relates to polyurethanes containing structural units corresponding to the following general formula:

NH-CO-NH--NH-OC-HN ~ S-R-S ~

R' R"
i !
wherein ~ R' and R", which may be the same or different, each represent - hydrogen, an alkyl radical having from 1 to 6 carbon ; 20 atoms, an aryl radical having from 6 to 15 carbon atoms, preferably having from 6 to 10 carbon atoms, a cycloalkyl radical having from 4 to 12 carbon atoms, preferably having from 6 to 9 carbon atoms, halogen, -NO2, -CN, OR"' or the radical -C-O-R"', wherein R"' represents an optionally bra~ched alkyl radical having from 1 to 6 carbon atoms; and R represents a straigh~ or branched-chain alkyl radical having from 1 to 25 carbon atoms, preferably : ~
~eA 16,262 -2-.... .

~0823~

having from 4 to 18 carbon atoms, which are interrupted by from 1 to 12, preferably from 1 to 6 atoms of nitrogen and/or oxygen and/or sulphur , in the form of secondary or tertiary amino groups;
: 5 urea or acid amide groups; ether, urethane, or ester groups; thioether, thiourethane or thio-ester groups; or which are i~terrupted by from 1 to 4, preferably 1 or 2, carbonyl groups.
Most preferably, the total number of interrupting :: `
; 10 groups is 1 or 2.
, Products in which the urea group is in the ortho- or para-posikion to the sulphur are preferred. Products in which the urea ~roup is in the ortho-position are particularly ~, .
preferred.

. 15 In addition, the invention also relates to a process : for the production of polyurethane elastomers by reacting poly~
- hydroxyl compounds having a molecular weight of from about 400 : to about 10,000 with diisocyanates and aro~atic diamines as chai~
- extenders, in which the diamines used correspond to the following ;
.~ 20 genexal formula~
~:~ 2 wherein R, R' and R" are as defined above.

It has surprisingly been found that o,o'-diamino~
. ~ .
diphenyl dithioethers, in particular, may be used in casting elastomer systems, even in the absence of organic solvents, and . provide for excellent processing conditions (sufficiently long pot life and unusually short in-mold time) in the production ~:~ of elastomers. The extremely quick hardening and, hence, the quick releasability of the moldings from molds, provides for a .
LeA 16,262 -3-:

`` IL01~2398 quicker working cycle than in cases where conventional amines are used. This is of considerable imp~rtance insofar as the commercial production of polyurethane elastomers is concerned.

: Among the further important advantages of the chain ~ 5 extenders used in the present invention are their ready avail-: ability and the fact that they are liquid at room temperature (low melting point). This enables them to be used as chain ~; extenders in polyurethane systems at lower temperatures than usual, thereby saving additional energy C05tS.

10 Preferred diamines are diamines wherein both amino groups are in the ortho position to the thioether group. It is also preferred to use diamines wherein Rl and R" represent -H, -OCH3, -OC2H5, -Cl or -OCOR"' (wherein R"' represents ,,, Cl-C6 alkyl ) .

~ 15 Particularly preferred polyurethanes are polyurethanes with the recurring structural unit: ;

H H
-HN-C-N N-C-NH- .

~ S-R-S ~

.: By varying the radical R, it is possible, on the one hand to specifically control the reactivity of the amino group; and on .
the other hand, to influence the mecha~ical properties of the polyurethane formed within wide limits. ~-The reactivity of amino groups in the o= position ; is considerably reduced by radicals R which are interrupted by hetero atoms (for example, in the form of ether, ester, carbonyl, acid amide, urea, urethan~, thiourethane, ox thioester groups).
... The reaction of diamines of this type with isocyanates only . begins at relatively high temperatures (long pot life), but is : LeA 16,262 -4-.~ .. . . : : -~082398 then completed very quickly (short in-mold time). Therefore, it is most preferred to use diaminodiphenyl-dithioethers which contain at least l and preferably 1 or 2 of the above-mentioned - groups in the radical R.

In addition, R groups which contain urethane and urea groups act as "internal hard segments" in the chain extender and, through ~he development of intermolecular and intramolecular hydrogen bridge bonds, influence the mechanical properties of the :~
resulting polymer.

~: lQ Some of the diaminodiphenyl dithioethers used in -` the invention are exemplified below~

S-CIi2-C-CE~2-S~ ; ~

~ .
- and compounds corresponding to the following general formula~
~ ' .
. NH2 NH2 ~ ;
lS ~ -S-R-5 wherein R represents one~ the following groups:
-- . . .
-(CH2)2-0 (CH2)2 ; -(cH2)4-o-(cH2)4 -(CH2)2-0-CH2-O (CH2)2 ; -C-C- ; -C-CH2-CH2-C-O O O O
., , ~, -:~ LeA 16,262 -5-- , . .

;lV8239~

: , , 3 - (CH ) -NH-C-N-CH -CH -CH -N-C-NH- (CH ) , O O
- (CH2 ) 6-NH~C~NH (Cl~2 ) 6 O
:

2) 2 C-NH- (CH2) 6-NH-C-O- (CH ) .~ O O
- (CH2 ) 6-NH-C-NH- (CH2 ) 2-NH-C-NH- (CH2 ) 6-' O O

-CH2 -C-O- (CH2 ) 2 . .
O
H ~ :.
.~ ( 2)3 C N (CH2)2- ; as well as . ~ O
compounds corresponding to the following general formula:

R' wherein R represents one of the above-mentioned groups and R' ` 10 represents -CH3, -CN, -OCH3, -C1 or -C-OR . ,~
:, o ~; It is of course also possible to use compounds which :
:~ are similar in structure to those mentioned above, but in which .:
., the two amino groups are in the para-position to the thioether ~.
~ group.
.. :....................................................................... , . -., 15 The diamines used in accordance with the invention ----~
i may be produced by known methods. For instance, one compound : known from the literature may be produced:

~: :
~;
':

` LeA 16, 262 -6-'`; ':

~l0~2398 2 I D.G. Forster and E~Er ~ S-(CH2)2-S-(cH2)2 ~ (1924)- from the dinitro l J ~ ' compound by reduction "~' with iron powder and acetic acid.

The other diamines used in accordance with the invention may be similarly obtained by reacting aminothio-phenolates with ~,~-dihalogen compounds or by reacting the nitrothio phenolates with dihalogen compounds, followed by hydrogenation.
':'' . ,'`, ~ -; Polyhydroxyl compounds suitable for use in the process of the present invention have a molecular weight of from about 400 to about 10,000, preferably from about 600 to about 4000. These polyhydroxyl compounds include polyesters, polyethers, polythioethers, polyacetals, polycarbonates and -~
polyester amides containing at least 2 and preferably from 2 to -~
4 hydroxyl groups, of the type known for the production of ~ homogeneous polyurethanes.

.,:j :Examples of suitable polyesters containing hydroxyl groups are reaction products of polyhydric, pre~erably dihydric, and optionally, trihydric, alcohols with polybasic, preferably dibasic, carboxyllc acids. Instsad of the free polycarboxylic acid~, the corresponding polycarboxylic acid anhydrides or esters of lower alcohols or mixtures thereof may also be u~ed for the production of the polyesters. The polycarboxylic acids may be aliphatic cycloaliphatic, aromatic and/or heterocyclic, and may optionally be substituted, for example, by halogen atoms, and/or be unsaturated. Examples of these polycarboxylic acids ~! 25 include: succinic acid, adipic acid, suberic acid, azelaic ~.
acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic ~`
acid, phthalic acid anhydride, tetxahydrophthalic acid anhydride, ~ -.
.', ' ~ LeA 16, 262 -7 ..

~0~2391~il hexahydrophthalic acid anhydride, tetrachlorophthalic acid anhydride, endomethylene tetrahydrophthalic acid anhydride, glutaric acid anhydride, maleic acid, maleic acid anhydride, fumaric acid, dimeric and trimeric fatty acids, such as oleic acid, (optionally in admixture with monomeric fatty acids), terephthalic acid dimethyl ester, terephthalic acid-bis-glycol ester, ana the like. Examples of suitable polyhydric alcohols include: ethylene glycol, 1,~- and 1,3-propylene glycol, 1,4-and 2,3-butylene glycol, l,~-hexane diol, 1,8-octane diol, ; 10 neopentyl glycol, cyclohexane dimethanol (1,4-bis-hydroxymethyl-cyclohexane), 2-methyl-1,3-propane diol, glycerol, trimethylol propane, 1,2,6-hexane triol, 1,2,4-butane triol, trimethylol-. ethane, pentaerythritol, quinitol, mannitol and sorbitol, methyl glycolside, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycols, dipropylene glycol, polypropylene -~ . .
glycols, dibutylene glycol and polybutylene glycols. The polyesters may contain terminal carboxyl groups. Polyester$ of lactones such as -caprolactone, or hydroxycarboxylic acids, .~ such as ~-hydroxy caproic acid, may also be used.

The polyethers containing at least two and usually ::
from two to eight, preferably two or three hydroxyl groups ~ suitable for use in the present invention, are also those of -. known type. They may be obtained, for example, by the poly-merization of epoxides, such as ethylene oxide, propylene oxide, ~ :
butylene oxide, tetrahydrofuran~ styrene oxide or epichlorohydrin, . on their own, for example, in the presence of BF3; or by the . chemical addition of these epoxides, optionally in admixture or successively to starter components with reactive hydrogen atoms, :~
~ such as water, alcohols or amines. Specific examples of such starter compounds include ethylene glycol, 1,3- or 1,2-propylene glycol, trimethylolpropane, 4,4'~dihydroxy diphenylpropane, :`; aniline, ammonia, ethanolamine and ethylene diamine. Sucrose . ~.
LeA 16,262 -8-~ . . .

:~08Z39tl~
:

polyethers of the type described in German Auslegeschrift 1,176,358, and 1,064,938 are also suitable for the purpose of the present invention. In many cases, it is preferred to use ~-polyethers of the type which contain predominant amounts of ~
. .
primary OH-groups (up to 90% by weight, based on all the OH-groups present in the polyether). Polyethers modified by vinyl polymers of the type obtaine~ for example, by the polymerization of styrene or acrylonitrile in the presence of polyethers (U.S. Patents: 3,383,351; 3,304,273; 3,523,093 and 3,110,695 and German Patent 1,152,536) are also suitable, as are poly-butadienes containing OH-groups.

Among the polythio-ethers, particular reference is made to the condensation products of thiodiglycol with itself and/or with other glycols, dicarboxylic acids, formal-dehyde, aminocarboxylic acids or aminoalcohoLs. Depending on the co-components, these products are polythio mixed ethers, poly-thio ether esters or polythio ether ester amides.

Suitable polyacetals include, for examplet those compounds which may be obtained from glycols, such as diethylene glycol, triethylene glycol, 4,4'-dioxethoxy diphenyl dimethyl methane and hexane diol, with ~ormaldehyde. Suitable polyacetal8 may also be obtained by polymerizing cyclic acetals.

Suitable polycarbonates containing hydroxyl groups are known and are obtainable, for example, by reacting diols, such as 1,3-propane diol, 1,4-butane diol and/or 1,6-hexane diol, diethylene glycol, triethylene glycol and tetraethylene glycol, with diarylcarbonates, such as diphenylcarbonate or ~-~ phosgene.

Examples of the polyester amides and polyamides include the predominantly linear condensates obtained from LeA 16,262 -9-, .

~08239~

polybasic saturated and unsaturated carboxylic acids or : anhydrides thereof and polyhydric saturated and unsaturated amino alcohols, diamines, polyamines and mixtures thereof.

Polyhydroxyl compounds already containing urethane or urea groups and optionally modified natural polyols, such as : castor oil, c~rbohydrates, starch, may also be used. Addition products of alkylene oxides with phenol formaldehyde resins or even with urea-formaldehyde resins may also be used.
~ , .
Representatives of these compounds are described, for example, in High Polymers, Vol XVI, "Polyurethanes, Chemistry and Technology", by Saunders-Frisch, Interscience Publishers, ., .
:~; New York, London, Vol. I, 1962, pages 32 to 42 and pages 44 to 54, and Vol. II, 1964 pages 5 to 6 and 198 to 199, and in Kunststoff-Handbuch, Vol. VII, Vieweg-Hochtlen, Carl-Hanser- ~-Verlag, Munich, 1966, for example on pages 45 to 71.
.:` '~
Other suitable st~ing:components include aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyi~o~
, cyanates of the type described, for example, by W- Siefken in ~ :
.:
.' JU5tU8 Liebigs Annalen der Chemie, 562, pages 75 to 136. The~e i, include ethylene diisocyanate; 1,4-tetramethylene diisocyanate; . .
1,6-hexamethylene diisocyanate; 1,12-dodecane diisocyanate;
cyclobutane-1,3-diisocyanate; cyclohexane-1,3- and 1,4-diisocyanate : ~:
and mixtures of these isomers; l-isocyanato-3,3,5-trimethyl-5-: isocyanatomethyl cyclohexane (German Auslegeschrift 1,202,785) :.
25 2,4- and 2,6-hexahydrotolylene diisocyanate, and mixtures of ~ ~
these isomers; hexahydro-1,3 and/or 1,4-phenylene dii~ocyanate ; ;
. perhydro-2,4'- and/or -4,4'-diphenyl methane diisocyanate; 1,3-and 1,4-phenylene diisocyanate; 2,4- and 2,6-tolylene diisocyanate : and mixtures of these isomers diphenyl methane--2,4'- and/or `~
. 30 -4,4'~diisocyanate; naphthylene-1,5-diisocyanate; triphenyl --: methane-4,4',4"-triisocyanate polyphenyl polymethylene poly-LeA 16,262 -10-39~ ~

isocyanates, of the type which ~ay be obtained by condensing aniline with formaldehyde, ~ollowed by phosgenation, and which are described, for example, in British Patents 87~,430 and 848,671, perchlorinated aryl polyisocyanates of the type des-cribed, for example, in German Auslegeschrift 1,157,601, poly-~- isocyanates containing carbodiimide groups of the type described in German Patent 1,092,007 diisocyanates of the type described in U.S. Patent 3,492,330; polyisocyanates containing allophanate groups of the type described, for example, in British Patent : 10 994,890, Belgian Patent 761,626 and published Dutch Patent Application 7,102,524; polyisocyanates containing isocyanurate -. ~
: groups of the type described, for example, in German Patents -~ 1,022,789; 1,222,067 and 1,027,394 and in German Offenlegung-.. sschrifts 1,929,034 and 2,004,048; polyisocyanates containing .
lS urethane groups of the type described, for example, in Belgian Patent 752,261 or in U.S. Patent 3,394,164, polyisocyanates con- :taining acylated urea groups according to German Patent 1,230,778 :
: polyisocyanates containing biuret groups of the type described, .. ~ for example, in German Patent 1,101,394, in British Patent .. 20 889,050 and in French Patent 7,017,514, polyisocyanates obtained by telomerization reactions of the type described, for example, in Belgian Patent 723,640, polyisocyanates containing estex groups of the type described, for example, in British Patents :;~ 965,474 and 1,072,956, in U.S. Patent 3,567,763 and in German Patent 1,231,688 and also reaction products of the above-.~ mentioned isocyanates with acetals according to German Patent -~
1,072,385.
. . .
. It i5 also possible to use the isocyanate-group-~ containing distillation residues accumulating the production :. . .
:~ 30 of isocyanates on a commercial scale, optionally in solution ... .
; in one or more of the aforementioned polyisocyanates.
:. :
LeA 16,262 -11-`' ' ' ' ' ~08~3~8 It is also possible to use mixtures of the aforementioned poly~
isocyanates.

In general, it is particularly preferred to use the ~
commercially readily available polyisocyanates, such as 2,4- .
and 2,6-tolylene diisocyanate and mixtures of these isomers ("TDI"); polyphenyl polymethylene polyisocyanates of the type obtained by condensing aniline with formaldehyde, followed by phosgenation ("crude MDI"); and polyisocyanates containing carbodiimide groups, urethanae groups, allophanate groups, iso-10 cyanurate groups, urea groups or biuret groups ("modified poly-~ isocyanates").

; Catalysts may also be frequently used. Examples of suitable known catalysts include: tertiary amines, such as triethylamine, tributylamine, N-methyl morpholine, N-ethyl 15 morpholine, N-cocomorpholine, N,N,N',N'-tetramethyl ethylene ; diamine, 1,4-diazabicyclo-(2,2,2)-octane, N-methyl-N'-dimethyl- ~ ;
aminoethyl piperazine, N,N-dimethyl benzylamine, bis-(N,N-diethylaminoethyl)-adipate, N,N-di-ethylbenzylamine, penta- :
methyldiethylene triamine, N,N-di-methyl cyclohexylamine, : 20 N,N,N',N'-tetramethyl-1,3-butane diamine, N,N-dimethyl-~-phenyl-: ethylamine, 1,2-dimethylimidazole and 2-methylimidazole. ;

Examples of tertiary amines containing hydrogen atoms capable of reacting with isocyanate groups include~
triethanolamine, triisopropanolamine, N-methyl diethanolamine, 25 N-ethyl diethanolamine, N,N-dimethylethanolamine and the reaction products thereof with alkylene oxiaes, such as propylene oxide and/or ethylene oxide.

Other suitable catalysts are silaamines with carbon silicon bonds of the type described, for example, in German 30 Patent 1,229,290. These include, 2,2,4-trimethyl-2-silamorpho-line and 1,3-diethyl-aminomethyl tetramethyl disiloxane.

LeA 16,262 -12-~.
- . : 1 , ' ' ;

~08Z39~

Suitable catalysts also include nitrogen-containing bases, such as tetraaikyl ammonium hydroxides; alkali metal hydroxides, such as sodium hydroxide; alkali metal phenolates such as sodium phenolate, or alkali metal alcoholates, such as socium methylate. Hexahydrotriazines may also be used as catalysts.

Organometallic compounds especially organotin compounds, may also be used as catalysts. Pr~ferred organotin compounds are tin-(II)-salts of carboxylic acids, such as ` 10 tin-(II)-acetate, tin-(II)-octoate, tin-(II)-ethylhexoate and tin-(II)-laurate, and the dialkyl tin salts of carboxylic acids, such as dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin maleate or dioctyl tin diacetate.

... .
Further representatives of suitable catalysts and details on the way in which the catalysts work may be found in Kunststoff-Handbuch, Vol. VII, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 19~6, for example on pages 96 to 102.
.;
The catalysts are generally used in quantities of from about 0.001 to about 10% by weight based on the quantity of polyhydroxyl c~mpounds having a molecular weight of about 400 to about 10,000.
.~

Surface-active additives (e.g. emul~ifiers) may also be used. Examples of emulsifiers include: ~he sodium salts of castor oil sulphonates or even of fatty acids or salts of fatty acids with amines, such as diethyl~mine/oleic acid or diethanolamine/stearic acid. Alkali metal or ammonium salts of sulphonic acids, such as those of dodecylbenzene sulphonic acid or dinaphthylmethane disulphonic acid or even of fatty acids, such as ricinoleic acid, or of polymeric fatty acids, may also be used as surface-active additives.

.
~ eA 16,262 -13-',:

-- lO~Z3~

It is also ~ossible to use reaction retarders, such as substances with an acid reaction. These include hydrochloric acid or organic acid halides. PigmentS or dyes, flameproofing agents such as tris-chloroethyl phosphate or ammonium phosphate and polyphosphate, stabilizers against the effects of ageing and weather; plasticizers, substances with fungistatic and bacteriostatic effects; fillers, such as barium sulphate, kieselguhr, carbon black or prepared chalk can also be used.

Further examples of the reaction retarders, ~ 10 stabilizers, flameproofing agents, plasticizers, dyes, fillers, - substances with fungistatic and bacteriostatic effects, and also details on the way in which these additives are to be used and how they work may be found in Kunststoff-Handbuch, Vol. VI, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966, for example pages 103 to 113. :~ :
~ .
According to the invention the reaction components are ~: .
reacted by the known single-stage process, by the prepolymer ~ ~ :
process or by the semi-prepolymer process, in many cases using machines of the type described, for example in U.S. Patent ::
2,764,565. Particulars of suitable processing equipment may be found, for example, on pages 121 and 205 of Kunststoff-Handbuch, Vol. VI, published by Vieweg and Hochtlen, Carl-Hanser-Verlag, Munich 1966.
' , The quantity in which the reaction components are used is generally selected in such a way that the molar ratio of : polyisocyanates to chain extenders plus compounds containing reactive OH-groups, depending upon the particular processing technique used, generally amounts to from about 0.9 to about 1.5, ~ :
preferably from 1.05 to 1.25. The NCO content of the prepolymer~
: 30 in cases where processing is carried out by way of the prepolymer stage, may amount to from about 2 to about 8% by weight, LeA 16,262 -14-~rcf(~rably 3.5 to G~. Tll~ molar ratio of reactive hydr~gen ln th~ chain e~ten(ler to reactive OH-groups may vary within wi(l~ limits, although it should preferably amount to from about 0.4 to about 1.5, whereby soft to hard polyurethanes are obtained. In addition to the diamines used in the invention, it is also possible to use, as chain extenders, proportions of oth~r diamines or even diols such as those of the type mentioned above in connection with the preparation of the polyhydroxyl compoullds. I~owever, the mole fraction of the amine of the in-stant invention in the chain extender should amount to from about 1 to about 0.5, and preferably from 1 to 0.8, based on the total amount of chain extender used.

The process of the present invention may be carried ` out in different ways. For example, the compound having at least two hydroxyl groups and a molecular weight of from about 400 to about 10,000 may be reacted with an excess of diisocyanates and the melt introduced into molds following addition of the chain ex~ender. A high-grade elastic polyurethane plastic is obtained after heating for several hours.

`, 20 In another embodiment, the relatively high molecular weight compound having at least two hydroxyl groups is reacted in admixture with the chain extender in an excess of diisocyanate, and the reaction product processed under heat and pressure after granulation. It is possible in this way to obtain polyurethane plastics differing in hardness and elasticity depending on the quantitative ratios in which the reactants are used. It is also possible in this way to produce plastics which may be processed in the same way as thermoplastics. In another embodimentl the relatively high molecular weight compound having at least two hydroxyl groups is reacted in admixture with the chain extender with a lesser amount of diisocyanate. This results in the LeA 16,262 -15- ;

.: . . ..

~08~;~98 formation of a rollable she~t which may be subsequently converted, into an elastomeric polyurethane plastic by such means as cross-linking with more diisocyanate.

Elastomers so produced may be used for numerous ` 5 applications ~uch as for moldings subjected to heavy mechanical stress.ing, rollers, V-belts or seals which are subjected to heavy thermal or chemical stressing, for hot-water pipes or motors or for the production of films, textile coatings and polyurethane p~wders.

The process of the invention is illustrated by the following examples. Unless otherwise indicated, all the figures quoted are parts by weight or percent by weight. ~ -:
. . , :
EXAMPLE 1 .~

Analytical data of o,o'-diaminodiphenyl-dithioethers ~ ~ ;
suitable for use in the process of the invention are summarized in the following Table~ Column 2 shows the radical R corres-ponding to the general structural formula~

~H2 NH2 The structure of the compound was also confirmed by nuclear magnetic resonance and mass spectrometry. ~ -,~ .
.
LeA 16,262 -16-- .

Z9z'gl ~aq ~ ~o~P ~0 , I ~ O O O
'a U~ N O d~
O o I I ~ I ~

O ~tO 1~ t~ a~ N a~ N tt~ D O 1` t~) :n o o~ I` co 1~ ,i ~ ,1 1` a~ ~o o ~ ~ ~i ~ ~i ~i CO CO
N ~ ~1 N ~ N r-l ~ ~1 ~I r-l rl ~I r-l ~1 ~I r-l ~I N N
O ~ N ~1 -1 Il) ~ I` ~D ~ ~ ~Id' CO ~ ~ I` _J
I I ~
I s~ O ~`I N ~ 1` 0 a~ O

H 51 N r-l ~r 'r ~ r--I N a~ ~) Lt~ 00 * N O O ~D t~ U'~ C0 u~

O ~ CO ~D ~ ~ ~) 1~ ~ t~ CO ~r N Cl~ N t`J O C~ O 1~ ~1 O .. .... .. .. ...
- ~! ~ ~ u~ ~ ~ u~
~ .. .. .. .. .. .. .. .. .. .. ..

'~; .. ..
~' U U C~ ~" o "~
ry rcr~ r~ rv N ~~ U')~ I r~ ~ r Ei ~ I ~ . ~ 1 ~~ o i ~1 ~ ' ~? ~ ~ ~r c 1 ~ -CJI r l ~ ~r~ r a~ ~ ~ v .: ~ r r r O ~ r O '~ C) ~ ~ - C ~r~
. ~ ~ ~ 011~ U~

. ~' .. ~ . ., ,~,.,., : . ' ~ ~N X ~ ~ ~ 8N ~ ~ IN

o ~ X h: I
Y~ ~) ~ O yN N ~ TN ~i ca = O ~ N ~N
.'',,' ~ I_ I .

_ ~_ _ ~ _ _ _ _ _ O r-l 8 r~l N t~ ~r Lt ) U~ al r l r~l ' ; -- 17 --~' : ' 23~

General Method _ 1 mol of NaOH or CH3ONa is dissolved in from 200 to 250 ml of ethanol. 1 mol of _-aminothiophenol is added dropwise to the resulting solution at from 50 to 60C. The solution is boiled under reflux for from 10 to 15 minutes, ~;
; followed by the dropwise addition at from 75 to 80C 0.5 mol of the corresponding dihalogen compound X-R-X (X represent3 Br or Cl). AEter stirring for 1 hour, the alcohol is distilled off and the solid residue washed with H2O until free from halogen. Compound 11/ an oil, is taken up in ether following removal of the alcohol, washed with H2O until free from halogen and after drying the ether solution over Wa2SO4 and removing the ether, is obtained in the form of a viscous, brown-red liquid.
.. ..
The same method may also be adopted for reacting dihalogen compounds with sodium nitrothiophenol or its deri-va~ives. Reduction of the nitro groups is best carried out with Raney nickel in methanol.

.
-~ Com~ounds 1 to 6 These compounds are prepared by the general method described above. The corrasponding dichlorides were used as dihalogen in each case.
:~ ' Compound 7 ~' ~
24.2 g of N,N'-dimethylethylene diamlne in 50 ml of dioxane are added dropwise at from 10 to 15C to 81.25 g of Cl-~CH2)6-NCO in 100 ml of dioxane. The reaction mixture is stirred for 2 hours at from 25 to 30C. The colorless crystalline deposit obtained, consisting of:

LeA 16,262 -18-.

2396~ `

o o ( 2)6 NH C N-(CH2)2-N-C-NH-(C~2)6-C

is filtered off under suction, washed with H2O and dried in vacuo. The dichloro-compound is reacted with sodium o-amino-thiophenol in accordance with the general method to form o,o'-di-aminodiphenyl dithioether.

Compound 8 , .
4.5 g of H2O and 2 drops of diazabicyclooctane ascatalyst are added to 80.75 g of Cl-(CH2)6-NCO in 2Q0 ml of ` dioxane, followed by boiling under reflux for 8 hours. After cooling to 25C, the colorless, crystalline deposit obtained, consisting of: Cl-(CH2)6-NH-C-NH-(CH2)6-Cl, ~ O
is filtered off under suction, washed with ether and dried in vacuo. The further procedure is the sàme as for compounds 1 to 7.
i 15 Compound 9 .. ~
40.5 of chloroethanol and 1% of di-_-butyl tin dilaurate as catalyst are added dropwise at from 15 to 20C
to 42 g of OCN-(CH2)6-NCO in 50 ml of dioxane, followed by stirring for 2 hours at from 25 to 30C. The colorless crystalline deposit obtained, consisting of:
Cl-(cH2)2-o-c-NH-(cH2)6-NH-c-o-(cH2)2-::' O o :;
.
` is filtered off under suction, washed with H O and dried ; n vacuo. The further procedure is the same as for compounds l to 7.

Compound lO

~- 15 g of ethylene diamine in 100 ml of dioxane are LeA 16, 262 -19-lOBZ398 addcd dropwise at from 0 to 15C to 8.25 g of Cl-(CH2)6-NCO
in 200 ml of dioxane, and the reaction mixture stirred for 2 hours at from 25 to 30C. The colorless, crystalline deposit obtained, consisting of:

Cl-(CH2)6-NH-C-NH-(CH2)2-NH-C-NH-(CH2)6 Cl " O ~:
is filtered off under suction, washed with water and dried ~:
in vacuo. The further procedure is the same as for compounds - 1 to 7.

Compound 11 . 10 This compound is prepared by the general method:
1 mol . 2 ~ ~:
+ 0.5 mol Cl-(CH2)2-S-(CH2)2-Cl E

NH2 : :~
:: ~
'. "' ' -(CN2)2-5-~C~2)2-S

~;~ 15 12.9 parts of 2,2'-diethylene ether dithiodianiline~

, NH2 H2N

S-(CH2)2-0-(cH2)2 ~eA 16,262 ~ -20-. . : ~ ~. - . . , -10l~239t8 are added at 85C to 100 parts of a prepolymer(NCO-content:

3,9 %) from a mixture of 65 % of 2,4- and 35 % of 2,6-toluylen~
diisocyanate and a polyester (OH-number: 56) from adipic acid, ethylene glycol and butylene glycol (NCO:NH2=1.10). The reacting mixture remains pourable for 190 seconds and may be removed from the mold after .

' .
~ .
" :
,,, . ' ' . `:
.

;
,.......................................................................... :

' Le A 16 262 - 20 a -.
. , .

~L08Z39~

5 minutes. ~fter tempering for 24 hours at 110C, the following ~;
mechanical values are measured;
Tensile strength: (DIN 53 504) 15 MPa/cm : Elongation at break: (DIN 53 504) 930 Tear propagation resistance: ~DIN 53 515) 30 KN/m Shore hardness (A): (DIN 53 505) 70 Elasticity: (DIN 53 512) 35%

~- :
15.45 parts of molten 2,2'-N,N'-hexamethylene urea dithiodianiline:
: ;:

NH2 ~2N ~ ~ !
( 2)6 C N (CH2)6 S
,, are added at 95C to 100 parts of a prepolymer according to Example 2 ~NCO:N~2 = 1:10~. ~he reacting mix~ure remains ,; ., ~
~; pourable for 120 seconds and may be removed from the mold after 20 minutes. After tempering for 24 hour~ at 110C, the following mechanical value~ are measured: :~
Tensile strength: ~DIN 53 504) 25.2 MPa/cm Elongation at break: (DIN 53 504) 417~
Tear propagation resistance: (DIN 53 515) 12 KN/m ;:. :
Shore hardness (A): (DIN 53 505) 74 Elasticity: (DIN 53 512) 38 "
-~ 12.45 parts of 2,2'-diethylene ether dithiodianiline :~
are added at 85C to 100 parts of a prepolymer having an NCO ~ ~.
content of 3.6%f ~ a mixture of 80% 2,4-tolylene diisocyanate . and 20~ 2,6-tolylene diisocyanate and a polyester (OH number 56) ~:

LeA 16,262 -21-.. . . . -23g~ ~

of adipic acid, ethylene glycol and butylene glycol (molar ratio of the glycols 7:3). The reacting mixture remains pourable for 4 minutes and may be removed from the mold after 20 minutes.
After tempering for 24 hours at 110C the ollowing mechanical values are measured:

Tensile strength: ~DIN 53 504) 10 MPa/cm Tear propagation resistance: (DIN 53 515) 15 KN/m Elongation at break: (DIN 53 504) 886%
Shore hardness (A): (DIN 53 505) 55 Elasticity: (DIN 53 512) 30% .

11.83 parts of 2,2'-acetonylene dithiodianiline:

`:

:s,.
are added ~t 95C to 100 parts o~ a prepolymer according to Example 4 ~NCO:NH2 = 1:10). The reacting mixture remains pourable for 5 minutes and may be removed from the mold a~ter 61 minutes. A~ter tempering for 24 hours a~ 110C, the following mechanical values are measuxed: :

Tensile ~trength: (DIN 53 504) 23.2 MPa/cm Elongation at break: ~DIN 53 504) 630 Tear propagation resistance: (DIN 53 515) 8 KN/m Shore hardness (A)o (DIN 53 505) 53 ~:
; Elasticity: (DIN 53 512) 30%

Le~ 16,262 -22-

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:-

1. Polyurethane elastomers containing structural units corresponding to the following general formula:

wherein R' and R", which may be the same or different, each represent hydrogen, an alkyl radical having from 1 to 6 carbon atoms, an aryl radical having from 6 to 15 carbon atoms, a cycloalkyl radical having from 4 to 12 carbon atoms, halogen, -NO2, -CN, OR"' or the radical wherein R"' represents an optionally branched alkyl radical having from 1 to 6 carbon atoms; and R represents a straight- or branched-chain aliphatic radical having from to 25 carbon atoms which is interrupted by from 1 to 12 atoms of nitrogen and/or oxygen and/or sulphur in the form of secondary or tertiary amino groups, urea or acid amide groups, other, urethane or ester groups, thioether, thiourethane or thioester groups or which is interrupted by from 1 to 4 carbonyl groups.

2. Polyurethane elastomers as claimed in Claim 1, wherein R represents an aliphatic radical having from 1 to 18 carbon atoms which is interrupted by 1 or 2 ether, thioether, ester, urea, urethane, thio-urethane, carbonyl or acidamide groups, R' and R" represent -H, -CH3, -C1, -CN, -OR"' or -COOR"', and R"' represents an optionally branched alkyl radical having from 1 to 6 carbon atoms.

3. Polyurethane elastomers as claimed in Claim 1 containing structural units corresponding to the general formula:

4. Polyurethane elastomers as claimed in Claim 1 containing structural units corresponding to the general formula:

5. A process for the production of polyurethane elastomers comprising reacting polyisocyanates, compounds having at least two active hydrogen atoms and molecular weights in the range of from about 400 to about 10,000 and aromatic diamines as chain extenders, wherein the diamines used correspond to the following general formula:

wherein R' and R", which may be the same or different, each represent hydrogen, an alkyl radical having from 1 to 6 carbon atoms, an aryl radical having from 1 to 15 carbon atoms, a cycloalkyl radical having from 4 to 12 carbon atoms, halogen, -NO2, -CN, OR"' or the radical , wherein R"' represents an optionally branched alkyl radical having from 1 to 6 carbon atoms; and R represents a straight- or branched-chain aliphatic radical having from 1 to 25 carbon atoms which is interrupted by from 1 to 12 atoms of nitrogen and/or oxygen and/or sulphur in the form of secondary or tertiary amino groups, urea or acid amide groups, ether, urethane, or ester groups, thioether, thiourethane, or thioester groups or from 1 to 4 carbonyl groups.

6. The process of Claim 5 wherein said diamines are diamines wherein R represents an aliphatic radical having from 1 to 18 carbon atoms which is interrupted by 1 or 2 ether, thioether, ester, urea, urethane, thio-urethane, carbonyl or acid amide groups, R' and R" represent -H, -CH3, -C1, -CN, -OR"' or -COOR"';
and R"' represents an optionally branched alkyl radical having from 1 to 6 carbon atoms.

7. The process of Claim 5 wherein said diamines are diamines corresponding to the general formula:

8. The process of Claim 5 wherein the diamines correspond to the general formula:

9. The process of Claim 5 wherein said aliphatic radical is interrupted by 1 or 2 carbonyl groups.

10. The process of Claim 5 wherein said aliphatic radical is interrupted by 1 or 2 ether groups.