Vulcanizable compositions based on nitrile rubbers containing epoxy groups

Abstract

There are provided novel vulcanizable compositions based on optionally fully or partly hydrogenated nitrile rubbers containing epoxy groups, and specific crosslinkers, which no longer require use of conventional crosslinkers, more particularly sulphur. The vulcanizates producible therefrom possess very good compression sets at room temperature, 100 C. and 150 C., and additionally exhibit high tensile strength combined with good elongation at break.

Claims

1. A vulcanizable composition comprising: (i) at least one nitrile rubber containing epoxy groups and comprising repeat units derived from at least one conjugated diene, at least one ,-unsaturated nitrile, and at least one monomer which contains epoxy groups, but not from a nonconjugated cyclic polyene, wherein the monomer which contains epoxy groups is selected from the group consisting of 2-ethylglycidyl acrylate, 2-ethylglycidyl methacrylate, 2-(n-propyl)glycidyl acrylate, 2-(n-propyl)glycidyl methacrylate, 2-(n-butyl)glycidyl acrylate, 2-(n-butyl)glycidyl methacrylate, glycidyl methacrylate, glycidylmethyl methacrylate, glycidyl acrylate, (3,4-epoxyheptyl)-2-ethyl acrylate, (3,4-epoxyheptyl)-2-ethyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, allyl glycidyl ether, allyl 3,4-epoxyheptyl ether, 6,7-epoxyheptyl allyl ether, vinyl glycidyl ether, vinyl 3,4-epoxyheptyl ether, 3,4-epoxyheptyl vinyl ether, 6,7-epoxyheptyl vinyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, and 3-vinylcyclohexene oxide; (ii) at least one crosslinker comprising at least one of: at least one Lewis acid selected from the group consisting of aluminium trichloride, indium(III) chloride, zinc chloride, iron(II) oxide, iron(III) oxide, iron(III) chloride, silicon tetrachloride, lithium bromide, lithium chloride, magnesium chloride, scandium(III) triflate, and rhodium(III) chloride and at least one Brnsted acid selected from the group consisting of potassium hydrogensulphate, ammonium hydrogensulphate, tetraalkylammonium hydrogensulphates, potassium dihydrogenphosphate, disodium hydrogenphosphate, sodium dihydrogenphosphate, ammonium chloride, ammonium sulphate, ammonium carbonate, ammonium hydroxide, dodecylbenzylsulphonic acid, p-toluenesulphonic acid, ascorbic acid, acetic acid, acrylic acid, fumaric acid, maleic acid, benzoic acid, abietic acid, and oleic acid; and (iii) crosslinkers other than those specified under (ii) in an amount of 0 to 2.5 parts by weight, based on 100 parts by weight of the nitrile rubber (i).

2. The vulcanizable composition according to claim 1, wherein the vulcanizable composition contains no other crosslinkers other than those specified under (i).

3. The vulcanizable composition according to claim 1, wherein the composition includes the at least one additional crosslinker (iii) in an amount less than 2.5 parts by weight, based on 100 parts by weight of the nitrile rubber (i).

4. The vulcanizable composition according to claim 3, wherein the at least one additional crosslinker (iii) is present in an amount of less than 1 part by weight, based on 100 parts by weight of the nitrile rubber (i).

5. A vulcanizable composition comprising: (i) at least one nitrile rubber containing epoxy groups, wherein the nitrile rubber is fully hydrogenated or partially hydrogenated and comprises repeat units derived from at least one conjugated diene, at least one ,-unsaturated nitrile, and optionally one or more further copolymerizable monomers, but not from a nonconjugated cyclic polyene; (ii) at least one crosslinker comprising at least one of: at least one Lewis acid selected from the group consisting of boron trihydride, aluminium trichloride, indium(III) chloride, copper(II) chloride, copper(I) triflate, gold(III) chloride, gold(I) chloride, zinc chloride, tin(IV) oxide, tin(IV) chloride, copper(II) oxide, iron(II) oxide, iron(III) oxide, iron(III) bromide, iron(III) chloride, sulphur trioxide, silicon tetrachloride, lithium bromide, lithium chloride, magnesium chloride, scandium(III) triflate, rhodium(III) chloride, and complexes of the following elements in the following oxidation states: Co(III), Al(III), Fe(III), Fe(II), Sn(IV), Co(II), Ni(0), Ni(II), Cu(II), Cu(I), Pb(II), Sn(II), Sn(IV), Ag(I), Au(I), Au(III), Pd(II), Pt(II), Sc(III), Ir(III), Rh(III) and In(III), and at least one Brnsted acid selected from the group consisting of sulphuric acid, hydrogensulphates, sulphurous acid, hydrogensulphites, hydrogen sulphide, hydrogensulphides, dipotassium hydrogenphosphate, potassium dihydrogenphosphate, disodium hydrogenphosphate, sodium dihydrogenphosphate, calcium hydrogenphosphate, trisodium hydrogendiphosphate, disodium hydrogendiphosphate, diphosphonic acid and the partial esters thereof, metaphosphoric acid, triphosphonic acid and the partial esters thereof, hydrogen carbonates, acids of the halogens, hypohalous acids, halous acids, halic acids, perhalic acids, ammonium chloride, ammonium sulphate, ammonium carbonate, ammonium hydroxide, inorganic and organic sulphonic acid, ascorbic acid, acetic acid, propionic acid, acrylic acid, fumaric acid, maleic acid, benzoic acid, abietic acid, oleic acid, phosphonic acid, and the mono- or diesters thereof; and at least one additional crosslinker (iii) other than those specified under (ii), in an amount of 0 to 2.5 parts by weight, based on 100 parts by weight of the nitrile rubber (i).

6. The vulcanizable composition according to claim 5, wherein: the at least one crosslinker comprises at least one of: at least one Lewis acid selected from the group consisting of aluminium trichloride, indium(III) chloride, zinc chloride, iron(II) oxide, iron(III) oxide, iron(III) chloride, silicon tetrachloride, lithium bromide, lithium chloride, magnesium chloride, scandium(III) triflate, and rhodium(III) chloride, and at least one Brnsted acid selected from the group consisting of potassium hydrogensulphate, ammonium hydrogensulphate, tetraalkylammonium hydrogensulphates, potassium dihydrogenphosphate, disodium hydrogenphosphate, sodium dihydrogenphosphate, ammonium chloride, ammonium sulphate, ammonium carbonate, ammonium hydroxide, dodecylbenzylsulphonic acid, p-toluenesulphonic acid, ascorbic acid, acetic acid, acrylic acid, fumaric acid, maleic acid, benzoic acid, abietic acid, and oleic acid.

7. The vulcanizable composition according to claim 5, wherein the nitrile rubber (i) is at least one of: a nitrile rubber in which the epoxy groups are applied to the nitrile rubber by subsequent grafting of compounds containing epoxy groups, and a nitrile rubber having repeat units of at least one nitrile, of at least one conjugated diene, of at least one monomer containing epoxy groups, and optionally of one or more further copolymerizable monomers, but none of any nonconjugated cyclic polyenes.

8. The vulcanizable composition according to claim 5, wherein the nitrite rubber (i) has repeat units derived from a monomer which contains epoxy groups, wherein the monomer which contains epoxy groups is at least one of o-vinylbenzylglycidyl ether, m-vinylbenzylglycidyl ether, p-vinylbenzylglycidyl ether, 3-vinylcyclohexene oxide, and monomers of the general formula (I) ##STR00003## in which m is 0 or 1 and X is O, O(CR.sub.2).sub.p, (CR.sub.2).sub.pO, C(O)O, C(O)O(CR.sub.2).sub.p, C(O)NR, (CR.sub.2).sub.p, N(R), N(R)(CR.sub.2).sub.p, P(R), P(R)(CR.sub.2).sub.p, P(O)(R), P(O)(R)(CR.sub.2).sub.p, S, S(CR.sub.R), S(O), S(O)(CR.sub.2).sub.p, S(O).sub.2(CR.sub.2).sub.p or S(O).sub.2, Y represents repeat units of one or more mono- or polyunsaturated monomers, comprising conjugated or nonconjugated dienes, alkynes and vinyl compounds, or a structural element which derives from polymers comprising polyethers, especially polyalkylene glycol ethers and polyalkylene oxides, polysiloxanes, polyols, polycarbonates, polyurethanes, polyisocyanates, polysaccharides, polyesters and polyamides, n and p are the same or different and are each in the range from 0 to 10 000, and R, R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different and are each H, a linear or branched, saturated or mono- or polyunsaturated alkyl radical, a saturated or mono- or polyunsaturated carbo- or heterocycyl radical, aryl, heteroaryl, arylalkyl, heteroarylalkyl, alkoxy, aryloxy, heteroaryloxy, amino, amido, carbamoyl, alkylthio, arylthio, sulphanyl, thiocarboxyl, sulphinyl, sulphono, sulphino, sulpheno, sulphonic acids, sulphamoyl, hydroxyimino, alkoxycarbonyl, F, Cl, Br, I, hydroxyl, phosphonato, phosphinato, silyl, silyloxy, nitrile, borates, selenates, carbonyl, carboxyl, oxycarbonyl, oxysulphonyl, oxo, thioxo, epoxy, cyanates, thiocyanates, isocyanates, thioisocyanates or isocyanides.

9. The vulcanizable composition according to claim 5, wherein the nitrile rubber (i) has repeat units derived from a monomer which contains epoxy groups, wherein the monomer which contains epoxy groups is selected from the group consisting of 2-ethylglycidyl acrylate, 2-ethylglycidyl methacrylate, 2-(n-propyl)glycidyl acrylate, 2-(n-propyl)glycidyl methacrylate, 2-(n-butyl)glycidyl acrylate, 2-(n-butyl)glycidyl methacrylate, glycidyl methacrylate, glycidylmethyl methacrylate, glycidyl acrylate, (3,4-epoxyheptyl)-2-ethyl acrylate, (3,4-epoxyheptyl)-2-ethyl methacrylate, 6,7-epoxyheptyl acrylate, 6,7-epoxyheptyl methacrylate, allyl glycidyl ether, allyl 3,4-epoxyheptyl ether, 6,7-epoxyheptyl allyl ether, vinyl glycidyl ether, vinyl 3,4-epoxyheptyl ether, 3,4-epoxyheptyl vinyl ether, 6,7-epoxyheptyl vinyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether and 3-vinylcyclohexene oxide.

10. A vulcanizable composition comprising: (i) at least one nitrile rubber containing epoxy groups and comprising repeat units derived from at least one conjugated diene, at least one ,-unsaturated nitrile, and optionally one or more further copolymerizable monomers, but not from a nonconjugated cyclic polyene, and (ii) at least one crosslinker comprises at least one of: at least one Lewis acid in a buffer mixture, wherein the at least one Lewis acid is selected from the group consisting of boron trihydride, aluminium trichloride, indium(III) chloride, copper(II) chloride, copper(I) triflate, gold(III) chloride, gold(I) chloride, zinc chloride, tin(IV) oxide, tin(IV) chloride, copper(II) oxide, iron(II) oxide, iron(III) oxide, iron(III) bromide, iron(III) chloride, sulphur trioxide, silicon tetrachloride, lithium bromide, lithium chloride, magnesium chloride, scandium(III) triflate, rhodium(III) chloride, and complexes of the following elements in the following oxidation states: Co(III), Al(III), Fe(III), Fe(II), Sn(IV), Co(II), Ni(0), Ni(II), Cu(II), Cu(I), Pb(II), Sn(II), Sn(IV), Ag(I), Au(I), Au(III), Pd(II), Pt(II), Sc(III), Ir(III), Rh(III) and In(III), and at least one Brnsted acid in a buffer mixture, wherein the at least one Brnsted acid is selected from the group consisting of sulphuric acid, hydrogenphosphates, sulphurous acid, hydrogensulphites, hydrogen sulphide, hydrogensulphides, dipotassium hydrogenphosphate, potassium dihydrogenphosphate, disodium hydrogenphosphate, sodium dihydrogenphosphate, calcium hydrogenphosphate, trisodium hydrogendiphosphate, disodium hydrogendiphosphate, diphosphonic acid and the partial esters thereof, metaphosphoric acid, triphosphonic acid and the partial esters thereof, hydrogen carbonates, acids of the halogens, hypohalous acids, halous acids, halic acids, perhalic acids, ammonium chloride, ammonium sulphate, ammonium carbonate, ammonium hydroxide, inorganic and organic sulphonic acid, ascorbic acid, acetic acid, propionic acid, acrylic acid, fumaric acid, maleic acid, benzoic acid, abietic acid, oleic acid, phosphonic acid, and the mono- or diesters thereof.

11. A vulcanizable composition comprising: (i) at least one nitrile rubber containing epoxy groups and comprising repeat units derived from at least one conjugated diene, at least one ,-unsaturated nitrile, and at least one monomer containing epoxy groups, but not from a nonconjugated cyclic polyene, where a proportion of the repeat units derived from the monomer containing epoxy groups is 2% to 35% by weight, based on overall nitrile rubber, (ii) 1 to 30 parts by weight of at least one crosslinker, based in each case on 100 parts by weight of the nitrile rubber (i), wherein the at least one crosslinker comprises at least one of: at least one Lewis acid selected from the group consisting of boron trihydride, aluminium trichloride, indium(III) chloride, copper(II) chloride, copper(I) triflate, gold(III) chloride, gold(I) chloride, zinc chloride, tin(IV) oxide, tin(IV) chloride, copper(II) oxide, iron(II) oxide, iron(III) oxide, iron(III) bromide, iron(III) chloride, sulphur trioxide, silicon tetrachloride, lithium bromide, lithium chloride, magnesium chloride, scandium(III) triflate, rhodium(III) chloride, and complexes of the following elements in the following oxidation states: Co(III), Al(III), Fe(III), Fe(II), Sn(IV), Co(II), Ni(0), Ni(II), Cu(II), Cu(I), Pb(II), Sn(II), Sn(IV), Ag(I), Au(I), Au(III), Pd(II), Pt(II), Sc(III), Ir(III), Rh(III) and In(III), and at least one Brnsted acid selected from the group consisting of sulphuric acid, hydrogensulphates, sulphurous acid, hydrogensulphites, hydrogen sulphide, hydrogensulphides, dipotassium hydrogenphosphate, potassium dihydrogenphosphate, disodium hydrogenphosphate, sodium dihydrogenphosphate, calcium hydrogenphosphate, trisodium hydrogendiphosphate, disodium hydrogendiphosphate, diphosphonic acid and the partial esters thereof, metaphosphoric acid, triphosphonic acid and the partial esters thereof, hydrogen carbonates, acids of the halogens, hypohalous acids, halous acids, halic acids, perhalic acids, ammonium chloride, ammonium sulphate, ammonium carbonate, ammonium hydroxide, inorganic and organic sulphonic acid, ascorbic acid, acetic acid, propionic acid, acrylic acid, fumaric acid, maleic acid, benzoic acid, abietic acid, oleic acid, phosphonic acid, and the mono- or diesters thereof; and (iii) at least one additional crosslinker other than those specified under (ii), in an amount of 0 to 2.5 parts by weight, based on 100 parts by weight of the nitrile rubber (i).

12. The vulcanizable composition according to claim 11, wherein: the repeat units of the at least one nitrile rubber consist of the repeat units derived from the at least one conjugated diene, the at least one ,-unsaturated nitrile, and at least one monomer containing epoxy groups, where the proportion of the repeat units derived from the monomer containing epoxy groups is 2.25 to 30% by weight, based on overall nitrile rubber, the vulcanizable composition contains 1.5 to 25 parts by weight of the crosslinker (ii), based on 100 parts by weight of the nitrile rubber (i), and the vulcanizable composition contains not more than 1.5 parts by weight of the crosslinkers (iii) based on 100 parts by weight of the nitrile rubber (i).

13. The vulcanizable composition according to claim 11, wherein: the repeat units of the at least one nitrile rubber consist of repeat units derived from a) acrylonitrile, b) 1,3-butadiene, c) glycidyl acrylate and/or glycidyl methacrylate, where a proportion of glycidyl acrylate and/or glycidyl methacrylate is 2.5 to 30% by weight, based on overall nitrile rubber, the vulcanizable composition contains 1.5 to 25 parts by weight of the crosslinker (ii), based on 100 parts by weight of the nitrile rubber (i), and the vulcanizable composition contains not more than 1.5 parts by weight of the crosslinkers (iii) based on 100 parts by weight of the nitrile rubber (i) containing epoxy groups.

14. A process for producing a vulcanizable composition according to claim 1, the process comprising mixing component (i) with component (i).

15. A process for producing vulcanizates based on an optionally partly or fully hydrogenated nitrile rubber containing epoxy groups, the process comprising crosslinking the vulcanizable composition according to claim 1 at a temperature of 20 to 250 C.

16. A vulcanizate obtained by the process according to claim 15.

17. The vulcanizable composition according to claim 11, wherein: the proportion of the repeat units derived from the monomer containing epoxy groups is 2.7 to 12.5% by weight, based on overall nitrile rubber, the vulcanizable composition contains 2 to 15 parts by weight of the crosslinker (ii), based in each case on 100 parts by weight of the nitrile rubber (i), and the vulcanizable composition contains not more than 0.4 parts by weight of the crosslinkers (iii) based on 100 parts by weight of the nitrile rubber (i).

Description

EXAMPLES

(1) The nitrogen content for determination of the acrylonitrile content (ACN content) in the inventive optionally fully or partly hydrogenated nitrile rubbers containing epoxy groups is determined to DIN 53 625 according to Kjeldahl. Due to the content of polar comonomers, the optionally hydrogenated nitrile rubbers containing epoxy groups are typically >85% by weight soluble in methyl ethyl ketone at 20 C.

(2) The glass transition temperature and what are called the onset and offset points are determined by means of Differential Scanning calorimetry (DSC) to ASTM E 1356-03 or to DIN 11357-2.

(3) The microstructure and the termonomer content of the individual polymers are determined by means of 1H NMR (instrument: Bruker DPX400 with XWIN-NMR 3.1 software, measurement frequency 400 MHz, solvent CDCl3).

(4) The values of the Mooney viscosity (ML 1+4@100 C.) are determined in each case by means of a shearing disc viscometer to DIN 53523/3 or ASTM D 1646 at 100 C. The MSR (Mooney Stress Relaxation) is determined in each case by means of a shearing disc viscometer to ISO 289-4:2003(E) at 100 C.

(5) The vulcanization profile in the MDR and the analytical data thereof were measured on a Monsanto MDR 2000 rheometer to ASTM D5289-95.

(6) The compression set (CS) at the temperature specified was measured to DIN 53517.

(7) The Shore A hardness was measured to ASTM-D2240-81.

(8) The tensile tests to determine stress as a function of deformation were conducted to DIN 53504 or ASTM D412-80.

(9) The abbreviations given in the tables below have the following meanings: RT room temperature (232 C.) TS tensile strength, measured at RT EB elongation at break, measured at RT M50 modulus at 50% elongation, measured at RT M100 modulus at 100% elongation, measured at RT M300 modulus at 300% elongation, measured at RT S min is the minimum torque of the crosslinking isotherm S max is the maximum torque of the crosslinking isotherm delta S is S maxS min t.sub.10 is the time when 10% of S max is attained t.sub.50 is the time when 50% of S max is attained t.sub.90 is the time when 90% of S max is attained t.sub.95 is the time when 95% of S max is attained TS2 is the time by which the Mooney viscosity has increased by two units compared to the starting point
The Following Substances were Used in the Examples:

(10) The following chemicals were purchased as commercial products from the companies specified in each case, or originate from production plants of the companies specified.

(11) Crosslinker (ii):

(12) ascorbic acid commercial product from Sigma Aldrich Chemie GmbH Cycat 600 dodecylbenzylsulphonic acid, 70% solution in isopropanol (commercial product from Cytec Industries Inc.) Cycat 4040 para-toluenesulphonic acid (commercial product from Cytec Industries Inc.) DDBS dodecylbenzylsulphonic acid; 70% solution in isopropanol (commercial product from Sigma Aldrich Chemie GmbH) KHSO.sub.4 potassium hydrogensulphate (commercial product from Sigma Aldrich Chemie GmbH) sodium ascorbate sodium salt of ascorbic acid (commercial product from Sigma Aldrich Chemie GmbH) Maglite DE magnesium oxide (commercial product from HallStar Company) TBAHS tetrabutylammonium hydrogensulphate (commercial product from Sigma Aldrich Chemie GmbH) Zinkoxyd Aktiv zinc oxide (commercial product from LANXESS Deutschland GmbH)
Other Substances Used in the Polymerization or in the Vulcanizable Composition: Corax N550/30 carbon black (commercial product from Evonik Degussa) Diplast TM 8-10/ST trioctyl mellitate (commercial product from Lonza SpA) Luvomaxx CDPA p-dicumyldiphenylamine (commercial product from Lehmann & Voss) Wingstay 29/Naugawhite mixture: mixture of 25 g of Sorbilene Mix (mixture of Sorbitan esters and ethoxylated sorbitan esters) from Lamberti, 38 g of Nauga-white (2,2-methylenebis(6-nonyl-p-cresol)) from Chemtura, 125 g of Wingstay 29 (styrenized diphenylamine) from Eliokem and 63 g of water Fe(II)SO.sub.4 premix solution contains 0.986 g of Fe(II)SO.sub.4*7 H.sub.2O and 2.0 g of RongalitC in 400 g of water Rongalit C sodium salt of a sulphinic acid derivative (commercial product from BASF SE) t-DDM tertiary dodecyl mercaptan (Lanxess Deutschland GmbH) Texapon K-12 sodium laurylsulphate (commercial product from Cognis Deutschland GmbH & Co. KG) Trigonox NT 50 p-menthane hydroperoxide (commercial product from Akzo-Degussa) Vulkanox ZMB2/C5 zinc salt of 4- and 5-methyl-2-mercaptobenzimidazole (commercial product from LANXESS Deutschland GmbH)

I Production of Nitrile Rubbers A, B, C and D

Inventive Examples

(13) Nitrile rubbers A, B, C and D used in the example series which follow were produced according to the base formulation specified in Table 1, with all feedstocks stated in parts by weight based on 100 parts by weight of the monomer mixture. Table 1 also specifies the respective polymerization conditions.

(14) TABLE-US-00001 TABLE 1 Production of nitrile rubbers A-D Nitrile rubber A B C D butadiene 62.25 63.5 58.5 54.5 acrylonitrile 36.0 36.0 35.5 37 glycidyl methacrylate 1.75 3.5 6 8.5 (GMA) Total amount of water 220 220 220 220 Texapon K-12 2.6 2.6 2.6 2.6 Na.sub.2SO.sub.4 0.12 0.12 0.12 0.12 pH 7 7 7 7 t-DDM 0.54 0.54 0.54 0.56 Trigonox NT 50 0.02 0.02 0.02 0.02 Fe(II)SO.sub.4 premix 0.027 0.027 0.026 0.026 solution diethylhydroxylamine 0.2 0.2 0.2 0.2 Wingstay 29/ 0.18 0.18 0.18 0.18 Naugawhite Polymerization 8.0 0.5 8.0 0.5 8.0 0.5 8.0 0.5 temperature [ C.] Polymerization 80 86 80 85 conversion [%] Polymerization time [h] 7.5 8 7 7

(15) The nitrile rubbers were produced batchwise in a 5 l autoclave with stirrer system. In each of the autoclave batches, 1.25 kg of the monomer mixture and a total amount of water of 2.1 kg were used, as was EDTA in an equimolar amount based on the Fe(II). 1.9 kg of this amount of water were initially charged with the emulsifier in the autoclave and purged with a nitrogen stream. Thereafter, the destabilized monomers and the amount of the t-DDM molecular weight regulator specified in Table 1 were added and the reactor was closed. After the reactor contents had been brought to temperature, the polymerizations were started by the addition of the Fe(II)SO.sub.4 premix solution and of para-menthane hydroperoxide (Trigonox NT50). The course of the polymerization was monitored by gravimetric determinations of conversion. On attainment of the conversions reported in Table 1, the polymerization was stopped by adding an aqueous solution of diethylhydroxylamine. Unconverted monomers and other volatile constituents were removed by means of steam distillation.

(16) The dried NBR rubbers were characterized by the Mooney viscosity, the MSR thereof, the ACN content and the glass transition temperature. The content of the termonomer was determined by .sup.1H NMR analysis. The rubbers obtained had the properties reported in Tab. 2.

(17) TABLE-US-00002 TABLE 2 Properties of nitrile rubbers A-D containing epoxy groups Nitrile rubber A B C D ACN content (%) 35.0 31.6 32.2 33.0 Mooney viscosity ML 25 27 31 30 (1 + 4 at 100 C.) (Mu) MSR (Mu/s) 0.669 0.581 0.671 0.650 Termonomer incorporated 1.2 2.7 4.7 7.2 (% by wt.) Glass transition temperature 23.1 31.0/21.6 25.1 21.9 T.sub.G ( C.)

II Production of Vulcanizates of the Nitrile Rubber Terpolymers A, B, C and D

Inventive Examples

(18) Nitrile rubber terpolymers A, B, C and D were used as described below to produce vulcanizates V1 to V17. The constituents of the vulcanizable mixtures are based on 100 parts of rubber and are reported in Tables 3, 7, 11, 15 and 19.

(19) The mixtures were produced in a Banbury Mixer. For this purpose, in each case, the rubber and all additives specified in Tables 3, 7, 11, 15 and 19 were mixed at a maximum temperature of up to 120 C. for a total of 4 minutes. For this purpose, the rubber was initially charged in the mixer, all further additives were added after 1 minute, and after 2 further minutes a reversal step was conducted. After a total of 4 minutes, the rubber was discharged from the mixer. The compound was vulcanized at a temperature of 210 C. for 120 min.

(20) TABLE-US-00003 TABLE 3 Composition of the vulcanizable mixtures for vulcanizates V1-V4 (Inventive Examples) Vulcanizable mixture for V1 V2 V3 V4 Polymer C 100 100 Polymer D 100 100 CORAX N 550/30 50 50 50 50 DIPLAST TM 8-10/ST 5 5 5 5 LUVOMAXX CDPA 1 1 1 2 VULKANOX ZMB2/C5 0.4 0.4 0.4 0.4 MAGLITE DE 2 2 2 2 ZINKOXYD AKTIV 3 6 3 6 Total phr 164.4 164.4 164.4 164.4 Density g/ccm 1.183 1.183 1.183 1.183

(21) The vulcanizates obtained had the properties reported in Tables 4 to 6:

(22) TABLE-US-00004 TABLE 4 Vulcanizates V1-V4; vulcanization profile in the MDR (210 C./60 minutes) Vulcanizate V1 V2 V3 V4 S max (dNm) 22.0 27.2 17.5 27.4 t.sub.10 (min) 5.4 9.7 3.9 10.2 t.sub.95 (min) 50.1 56.9 56.2 56.9

(23) The level of the respective maximum torque is in accordance with the proportions of Lewis acid.

(24) TABLE-US-00005 TABLE 5 Vulcanizates V1-V4, properties Vulcanizate V1 V2 V3 V4 Crosslinking C. 210 temperature Crosslinking min 120 120 120 120 time TS MPa 19.1 22.5 18.4 20.5 EB % 249 323 206 298 M50 MPa 3.1 2.9 3.7 2.9 M100 MPa 7 6.7 8.3 6.6 M300 MPa 21.3 20.1 Hardness Shore A 74 72 76 72

(25) The inventive vulcanizates feature high tensile strength and high modulus values at 100% elongation.

(26) TABLE-US-00006 TABLE 6 Vulcanizates V1-V4, compression set at RT, 100 C. and 150 C. Vulcanizate V1 V2 V3 V4 Temperature and time: RT; 24 hours CS % 4 4 4 4 Temperature and time: 100 C./24 hours CS % 7 14 9 14 Temperature and time: 150 C./24 hours CS % 23 22 31 22

(27) By virtue of the novel crosslinking structure with Lewis acid as a catalyst, it is also possible without any problem to establish unusually good compression sets, even at 150 C., still coupled with good elongation at break and maximum torque in the vulcanizate.

(28) TABLE-US-00007 TABLE 7 Composition of the vulcanizable mixtures for vulcanizates V5-V7 (Inventive Examples with inorganic acids) Vulcanizable mixture for V5 V6 V7 Polymer A 100 Polymer B 100 Polymer C 100 CORAX N 550/30 50 50 50 DIPLAST TM 8-10/ST 5 5 5 LUVOMAXX CDPA 1 1 1 VULKANOX ZMB2/C5 0.4 0.4 0.4 potassium hydrogensulphate 4 4 4 Total phr 160.4 160.4 160.4 Density g/ccm 1.16 1.16 1.16

(29) The mixtures were produced in a Banbury Mixer. For this purpose, the rubber and all additives specified in Table 6 were mixed at a maximum temperature of up to 120 C. for a total of 4 minutes. For this purpose, the rubber was initially charged in the mixer, all further additives were added after 1 minute, and after 2 further minutes a reversal step was conducted. After a total of 4 minutes, the rubber was discharged from the mixer. The compound was vulcanized at a temperature of 190 C. for 30 min.

(30) The vulcanizates obtained had the properties reported in Tables 8 to 10:

(31) TABLE-US-00008 TABLE 8 Vulcanizates V5-V7; vulcanization profile in the MDR (190 C./30 minutes) Vulcanizate V5 V6 V7 S max (dNm) 7.9 15.5 33.1 t.sub.10 (min) 0.8 0.6 0.9 t.sub.95 (min) 24.4 21.3 12.7

(32) The level of the respective maximum torque is in accordance with the proportions of monomers containing epoxide groups in the polymers in relation to the inorganic Brnsted acid. All crosslinkings were conducted without the addition of heavy metal compounds as a catalyst.

(33) TABLE-US-00009 TABLE 9 Vulcanizates V5-V7; properties Vulcanizate V5 V6 V7 Crosslinking C. 190 temperature Crosslinking time min 30 30 30 TS MPa 13.5 12.4 12.0 EB % 487 250 150 M50 MPa 1.3 2.1 3 M100 MPa 2 4.1 7.1 M300 MPa 7.8 Hardness Shore A 71 65 74

(34) The elongations at break and tensile strengths can be adjusted via the ratio of epoxide to acid.

(35) TABLE-US-00010 TABLE 10 Vulcanizates V5-V7; compression set at RT; 100 C. and 150 C. Vulcanizate V5 V6 V7 Temperature and time: RT, 24 hours CS % 13 3 1 Temperature and time: 100 C., 24 hours CS % 26 16 7 Temperature and time: 150 C., 24 hours CS % 69 51 29

(36) With inorganic acids too as the catalyst, it is possible to establish unusually good compression sets even at 150 C.

(37) TABLE-US-00011 TABLE 11 Composition of the vulcanizable mixtures for vulcanizates V8-V12 (Inventive Examples with organic acids) Vulcanizable mixture for V8 V9 V10 V11 V12 Polymer B 100 Polymer C 100 100 100 100 CORAX N 550/30 50 50 50 50 50 DIPLAST TM 5 5 5 5 5 8-10/ST LUVOMAXX CDPA 1 1 1 1 1 VULKANOX 0.4 0.4 0.4 0.4 0.4 ZMB2/C5 CYCAT 600 4 4 CYCAT 4040 2 ascorbic acid 2 DDBS 1.4 Total phr 160.4 160.4 158.4 158.4 157.8 Density g/ccm 1.14 1.14 1.14 1.14 1.14

(38) The vulcanizates obtained had the properties reported in Tables 12 to 14:

(39) TABLE-US-00012 TABLE 12 Vulcanizates V8-V12, vulcanization profile in the MDR (190 C./30 minutes) Vulcanizates V8 V9 V10 V11 V12 S max(dNm) 19.8 25.8 24.1 19.6 25.9 t.sub.10 (min) 0.9 0.8 0.8 1.3 1.0 t.sub.95 (min) 24.8 23.6 22.8 21.5 23.8

(40) The level of the respective maximum torque is in accordance with the proportions of monomers containing epoxide groups in the polymers in relation to the organic Brnsted acid. All crosslinkings were conducted without the addition of heavy metal compounds as a catalyst or any other compounds.

(41) TABLE-US-00013 TABLE 13 Vulcanizates V8-V12, properties Mixture V8 V9 V10 V11 V12 Crosslinking C. 190 temperature Crosslinking min 30 30 30 30 30 time TS MPa 17.6 15.4 24.7 20.8 23.5 EB % 347 168 328 348 301 M50 MPa 1.4 3.5 1.9 1.9 2 M100 MPa 2.8 8 4.5 4.2 4.8 M300 MPa 14.7 22.7 17.6 23.1 Hardness Shore A 60 71 66 65 66

(42) The elongations at break and tensile strengths can be adjusted via the ratio of epoxide to acid and the selection of the acid.

(43) TABLE-US-00014 TABLE 14 Vulcanizates V8-V12; compression set at RT, 110 C. and 150 C. Mixture V8 V9 V10 V11 V12 Temperature and time: RT; 24 hours CS % 4 3 nd.sup.1) nd nd Temperature and time: 110 C.; 24 hours CS % 17 10 nd nd nd Temperature and time: 150 C.; 24 hours CS % 52 36 34 47 36 .sup.1)nd: not determined

(44) With these organic acids too and all of those which follow as the catalyst, it is possible to establish unusually good compression sets even at 150 C.

(45) TABLE-US-00015 TABLE 15 Composition of the vulcanizable mixtures for vulcanizates V13-V16 Vulcanizable mixture for V13 V14 V15 V16 Polymer C 100 100 100 100 CORAX N 550/30 50 50 50 50 DIPLAST TM 8-10/ST 5 5 5 5 LUVOMAXX CDPA 1 1 1 1 VULKANOX ZMB2/C5 0.4 0.4 0.4 0.4 TBAHS 0.5 1 2 4 Total phr 156.9 157.4 158.4 160.4 Density g/ccm 1.14 1.14 1.14 1.14

(46) The vulcanizates obtained had the properties reported in Tables 16 to 18:

(47) TABLE-US-00016 TABLE 16 Vulcanizates V13-V16; vulcanization profile in the MDR at 190 C./30 minutes Vulcanizates V13 V14 V15 V16 S max (dNm) 27.7 25.5 20.0 12.6 t.sub.10 (min) 3.5 2.2 2.4 1.7 t.sub.95 (min) 26.3 24.3 23.1 24.0

(48) The level of the respective maximum torque is in accordance with the proportions of monomers containing epoxide groups in the polymers in relation to the organic Brnsted acid. All crosslinkings were conducted without the addition of heavy metal compounds as a catalyst or any other compounds.

(49) TABLE-US-00017 TABLE 17 Vulcanizates V13-V16; properties Vulcanizates V13 V14 V15 V16 Crosslinking C. 190 temperature Crosslinking min 30 30 30 30 time TS MPa 20 19.1 22.7 22.2 EB % 251 236 434 581 M50 MPa 3 2.7 1.8 1.3 M100 MPa 7.4 6.8 3.9 2.44 M300 MPa 16 10.8 Hardness Shore A 73 72 64 61

(50) Elongation at break and tensile strength can be adjusted via the ratio of epoxide to acid.

(51) TABLE-US-00018 TABLE 18 Vulcanizates V13-V16; compression set at 150 C./24 hours Temperature: Vulcanizates 150 C./24 hours V13 V14 V15 V16 CS % 21 17 28 49

(52) TABLE-US-00019 TABLE 19 Vulcanizable mixture for vulcanizate V17 (Inventive Examples with buffer system) Vulcanizable mixture for V17 Polymer C 100 CORAX N 550/30 50 DIPLAST TM 8-10/ST 5 LUVOMAXX CDPA 1 VULKANOX ZMB2/C5 0.4 ascorbic acid 2 sodium ascorbate 2.24 Total phr 160.6 Density g/ccm 1.14

(53) The vulcanizate obtained had the properties reported in Tables 20 to 22:

(54) TABLE-US-00020 TABLE 20 Vulcanizate V17, vulcanization profile in the MDR (190 C./30 minutes) Mixture V17 S max (dNm) 15.3 t.sub.10 (min) 1.5 t.sub.95 (min) 21.9

(55) All crosslinkings were conducted without the addition of heavy metal compounds as a catalyst or any other compounds.

(56) TABLE-US-00021 TABLE 21 Vulcanizate V17, properties Vulcanizate V17 Crosslinking temperature C. 190 Crosslinking time min 30 TS MPa 17.6 EB % 377 M50 MPa 1.7 M100 MPa 3.5 M300 MPa 14.1 Hardness Shore A 65

(57) TABLE-US-00022 TABLE 22 Vulcanizate V17; compression set at 150 C./24 hours Temperature and time: Vulcanizate 150 C., 24 hours V17 CS % 43

(58) With buffer systems too, it is thus possible to establish unusually good compression sets even at 150 C.