IL10992A - Vulcanized elastomers from substantially amorphous polymers and copolymers of alpha olefins and process for preparing the same - Google Patents

Description

invention relates to elastomers obtained from polyole particularly from copolymers of with and to a process for making It is known that products having the properties rubber can be obtained from polymers of the olefins having the general formula where is an alkyl and from copolymers of said olefins with each othe and with them to chlorosulphonating In wa functional groups can be introducted j into polymeric capable of forming the successive vulcanization basic substances such for metal oxides or transformation of the polymers having the characteristics of viscous into vulcanised elastomers according to the process essentially in successive and carry out the first operation in such a way that finished products of good technological characteristics are obtained at a moderate is not too In fact this operation has to be carried out in general on polymers dissolved i in relatively low concentrations some units procedure involves various particularly those of obtaining a ohlorosulphonated polymer of solvents and of recovering considerable amounts of solvent if the chlorosulphonation in particular the are carefully a strong degradation of the polymer can resulting in a worsening of the mechanical and elastic properties of the final metal oxides and particularly of lead for vulcanizing the chlorosulphonated causes on the other increase of the elastic hysteresis and therefore a worsening of the most properties of the Chlorosulphonation is a chemical transformation which requires the o aggressive and corrosive chemical such as and partioular This treatment cannot be easily c arried out by the normal users of crude manufacture of finished the manufacturer of saturated copolymers could not sell as they to his customers but had to carry out himself the chemical treatmen to the copolymers into a product which can be It is also possible obtain elastomers from low unsaturation copolymers obtained by olefins being an ro and ethylene with small amounts of dienes or acetylenic These polymers can be with sulphur or compounds release sulphur using mixes eontainig vulcanization accelerators the rapid or The mechanical and elastic properties of the elastomers obtained after vulcanization are good when starting copolymer shows a sufficiently regular distribution of the double in each macromolecule and all the contain approximately the same umber of double The more the distribution of the the poorer are the properties of The elastomers from these copolymers have therefore some imes poor elastic instance values of the permanent se at break of and have now found that substantially linear polymers of aliphatic olefins CH where E ia lower group and substantially amorphous copolymers of the olefins with each and with as our patent specification by low pressure processes based on the use catalysts containing and which contain a high number of tertiary can be directly vulcanized to products having valuable elaatomeric properties by grafting to polymeric chain organic compounds containing functional acid More we have found in the case o linear polymer or copolymers of the aforementioned types it is possible to form between the various polymeric that to obtain through a radical type I particular the vulcanization of polymers containing units deriving from be obtained using organic compounds containing double bonds and functional groups in their and capable of reacting with said polymers in the presence of radical type we have found it preferable that the compound to be grafted on to the polymeric chains contains a double bond conjugated with the double bonds of one or more number of using relatively small of the compound to be it is useful to employ a such as maleic acid or maleic that a moderate tendency to polymerise and to yield polymers of high molecular which easil chain It is known that maleic anhydride and other compounds of the mentioned type can be used for vulcanizing polymers having a high degree of unsaturation at least copolymerized this is disclosed for instance in the OSA patents in which maleic anhydride used in the presence of radical type initiators and zinc for the vulcanization of highly unsaturated According to the indications of said high amounts of bensoyl peroxide and anhydride are generally The vulcanisation process has been interpreted by assuming that maleic anhydride binds itself to the double in the polymeric thus of 4 carbon atoms attached to acidic nature capable of forming salts with thus forming links and vulcanising the In in the a p the necessity of zinc oxide to obtain vulcanized products is clearly On tho it was not that saturated this How have found that organic compounds of the aforementioned containing double can be grafted also on to saturated polymeric chains and that for such i is convenient that tertiary carbon in particular of the type H in which the hydrogen atom of tertiar carbon atom is very present in the saturated polymeric In this case it is not necessary that the chain contains double the small amounts of double bonds in the chain is not but is not necessary Our method permits in f act the vulcanization not only of saturated polymers but also of unsaturated containing a very low number of double which cannot be easily vulcanized by usual methods based on the use of Employing these methods which are of the present patent it therefore possible to vulcanize also the low unsaturatio copolymers of with small amounts of dienes or which are mentioned thus producing elastomers of good mechanical and elastic of the mechanisms which have been proposed or explaining the typical processes of maleic anhydride such as the addition to conjugated the aforementioned Brown the copol merization with th suhstances containing double such as in the preparation of polyester the substitutive addition to meth groups in position with respect to double explain the vulcanization process is an object of the present said process can therefore be interpreted only assuming a completely different from those mentioned In the vulcanization occurs on products which do not contain double anhydride is used a double bond expound to can place through the following formation of a radical on the polymer chain C EH where a the The radical formed according to can react with a anhydride according to the with the formation of a free new radical could react with further molecules of maleic anhydride according to a reaction similar to Such a reaction in fact occurs more easily with compounds different from maleic such vinyl or vinylidene compounds acr or It is to be assumed that with ethylenic compounds as derivatives or crotonio the tion of polymeric chains is less probable and other radical type reactions preferably such aa the reaction a mutual the C CH GO GO or a termination of the radical chains by can 2 or a termination of the growing by combination with a transfer to or radicals originating from another polymeric Other reactions can occur at the same time such as initiators supply free mixing benzoyl to a certain degree of In table 1 most properties of vulcanised products obtained by mixing an with 1 benzoyl peroxide and various amounts of maleic anhydride are set Table Maleic of polymer 0 23 700 50 50 9 4 490 20 3 6 Θ 52 450 15 28 5 of polymer Prom the of 1 it is clear that the presence of maleic anhydride permits to reach a good vulcanization and this can be explained according to reactions and elastomers obtained with mixtures containing oxide in addition to maleic anhydride are vulcanized still better than those obtained in absence of and this can be plained that oxide forms sal bonds between various reacting with the anhydride groups which can bound to the chains according to reactions and In this result is only with compounds containing at least one double bond capable of reacting through a radieal type and free ducts a copolymer of and containing 47 with the aid of maleic in comparison with those of products prepared the aid of or succinic instead of maleic Sable 2 For 100 by copolymer benzoyl peroxide 2 2 2 maleic acid 9 dimethyl maleate 11 succinic aeid 9 oxide 20 20 20 Vulcanisation at for minutes 2 Ultimate tensile 125 47 45 Elongation at break 460 835 980 Modulus at 25 8 7 of laaleic acid or anhydride other unsaturated compounds containing acidic such as furaaric methacrylic ethaoryclic methyl methyl citraconic anhydride be certain of such as acrylic are easily are chains containing a higher number of units may be grafted on the and in order to reach the same degree of a larger amount of must be moat important istics of obtained from a copolymer of approximately by grafting of various unsaturated and vulcanization are re orted in fable compound added to mix the amount necessary to obtain carboxyl equivalents for 100 g of Vulcanization was carried out at for 30 5 Unsaturated Ultimate Elongation Modulus Rebound Hardness compound tensile at break at at grafted strength 18 national acid 150 550 57 73 56 aoid 92 620 4 71 49 anhydride 92 460 56 73 55 acrylic 94 445 67 73 51 itaconic acid 105 500 67 71 53 acid 85 455 68 72 52 64 570 44 72 53 Radical initiators useful in the process comprise azo such as benzoyl cusayl lauryl the peroxides of ethyl ketone and tertiary butyl peroxidi tertiary butyl tertiary vulcanization temperature and duration have to be chosen in to the type of initiator taking into the fact that the different initiators yield free radicals at different Compounds capable of forming salt bridges between the various polymeric together with the acidic al comprise metallic oxides and diamines the metal oxides particularly Table 4 shows the characteristics of products from copolymer of molecula weight approximately using peroxide 2 acid 9 and metal oxide or hydroxide 100 Vulcanisation at for 30 4 r CaO GdO PbO eO Me Tensile 132 112 109 151 128 110 85 strength cm2 Elongation at 433 367 553 487 480 567 Modulus a 70 94 51 57 70 60 45 Rebound at 72 71 73 73 73 7 Hardness 59 61 56 59 56 we the vulcanization of the polymers ing may be carried the in a roll the type ased processing rubbers with the various More precisely the polymer ma be introduced first into the mixer until a homogenous and flexible sheet is the radical initiator and the saturated compound may then be added to the sheet and mixing continued a complete homogenization vith the polymer is if the agent capable of may be The vulcanization is then carried out in a press or autoclave at high for instance and pending on the ingredients of the and particularly on of radical Initiator mixing of the polymer radioal initiator and the compound to grafted also be carried out other for a good may be tained operating in presence of in particula which dissolves the various components the a benaene solution of an copolymer directly as obtained in polymerisation may be employed after removal of the catalyst adding to the solution benzoyl peroxide and anhydride at temperatures not higher than and preferabl between 40 and product obtained may be separated om the solvent by evaporating this under The product obtained then be process which an object of the present patent may also be carried out in a under oertain aspects When carrying out the process as described since the initial mix is a the possibility of grafting the unsaturated compound on the polymer chain may be considerably reduced by the effect of other actions take place during the mixing and the the formation of salts between the unsaturated compound acidic groups the basic reactions the radical and the unsaturated scission of the polymer sulting in a reactions can considerably lower yield of graft referred to unsaturated added to the and can also lead to the formation of compounds which act as inert charges or thus lowering the mechanical and elastic characteristics of the It has also been observed that the addition to the initial mix of carbon peptizing and radical leads general to the formation of elastomers having poorer mechanical and elastic This is probably due to the fact that these tend to block the free radicals present in the polymer thus both the grafting of unsaturated compound on the polymer chain and the formation of by coupling of free It is known that these substances favour scission actions rather than and thus can favour a degradation of the It is therefore in order to obtai with better elastic and ageing to carry out the process in or store separate so that first CO the on of the J unsaturated compound having functional acid groups the by means of polyfunctlonal basic substances such as polyvalent metal diamines mixed with the radical and the unsaturated the mixture thus obtained is heated to high preferably in the absence of a graft which in cases also contain a high proportion of is The duration of the thermal treatment and the ture to be reached depend mainly on the amount and type of radical initiator they can be so selected after the thermal the radical initiator is practically completely thus obtaining the greatest possible number of grafted functional polymer is then suitably treated in a roller to and homogenise it and finally the desired amount of basic agent is The mixture thus obtained is finally vulcanised elastomers with ver good elastic and ageing In fable 5 the mechanical of an propylene copolymer after the first with benzoyl peroxide and and the second treatment with 5 Graft Vulcanised copolymer copolymer Ultimate tensile 100 Elongation at 725 780 Modulus at elongation 10 In thio od elastomers may be the polymer with of radical initiator and of lower than when the process is carried out in only one In ble 6 report the most tics of a produc obtained an copolymer 69 by the method 2 parts dibenzoyl 9 parts maleic acid and 20 parts referred to 100 parts in comparison those of a product obtained from the copolymer by the using 1 part dibenzoyl 3 parts parts antioxidant and 10 parts zinc oxide per 100 parts Table Direct Vulcanisation in te stages Ultimate tensile Elongation at break 840 780 Modulus at 24 25 additio of antioxidants to the does not the subsequent with sine as it can be seen in table the elastomer can therefore effectively protected the action of and its resistance against the degradation caused by the atmospheric can in general increased J has also been noted that the addition of siderable to of saturated organic such stearic oxalic to the graft before the addition of ainc causes an improvement in the mechanical and elastic characteristics of the vulcanized In table 7 report the most obtained from an ethylene copolymer by according to the step using 10 zinc oxide and various amounts of stearic acid copolymer previously grafted with 3 maleic acid in the presence of one part Table 7 Stearic acid Ultimate tensile Elongation at Modulus at parta per 100 strength break parts of 95 600 38 6 116 630 40 11 140 730 31 Vulcanization at for 45 further The thermal treatment in which the grafting is can be protracted until a complete decomposition of the radical initiator takes in this way the presence of the in the finished elastomer is presence particularly in relation to the ageing of the Moreover carbon black can be added in the large amounts required in articles subjected to high mechanical without the mechanical and elastic properties of th In fact operating according to the step method the vulcanization is obtained mainly by formation of ionic and not by formation of to coupling and therefore carbon black and other reinforcing fillers can exert their reinforcing activity without hindering the addition of such fillers iaproves remarkably the abrasion further increases the elastic and the ultimate tensile strength and in general the resistance to oxidation and caused by light and In particular carbon the mechanical properties at high In the method the ing of the unsaturated compound the polymer chains can be obtained by mixing the radical initiator with the unsaturated compound in the roll mixers for and successive thermal treatment in oven press at high to It is in this thermal to operate in the absence of in order to avoid degradation of the Also the grafting may be i out in the copolymer solution as obtained directly in the adding the radical initiator and the unsaturated compound to the aolution and heating the solution to high temperature until the graft polymer She latter can be recovered by coagulation o tion under reduced pressure and then as the vulcanized which are an of the present show very good which can be varied over wide limits by starting and in the case of their the amount to and type of compound to be grafted the amount comprised of the of forming salt bridges For when elastomers are substantially copolymers obtained our patent specification the values of ultimate tensile elastic modulus and impact resilience increase with the increase of the ethylene conditions 2 and 3 above being Using increasing amounts of an agent capable of forming salt the properties of the vulcanized produc in general in a manner that elastomers having higher values of ultimate elastic and impact resilience result other factors being In fact making 100 parts of an copolymer with 2 parts 7 parts and variable amounts of after vulcanising at for 45 minutes for the following results to be Table 8 ZnO per 100 0 5 0 25 50 copolymer Ultimate tensile strength 100 142 160 Elongation at break 465 520 51 475 460 Modulus a 100 11 14 16 18 Rebound at 64 79 66 at 70 81 80 49 53 55 56 ratio When finely metal oxides are used as agents capable of forming salt an increase of surface hardness and an Improvement of the abrasion resistance If no metal oxide is added to the the vulcanized products show the characteristic of being which can be interesting for many the presence of free groups facilitates their adhesion to surfaces and their use can be particularly venient for coating The saturated or substantially saturated elastomers obtainable by the process here described in comparison wit highly the advantage of a higher resistance to oxidation and Moreover the elastomers obtained from containing from to have a curve similar to that of amorphous products capable of crystallization by It is therefore possible to obtain rubbers even low initial reach high strains at high stresses curve operating according to a rubber is obtained which has a modulus 2 lower than 2 an elongation at break of about and an ultimate rength of Example 1 100 parts of an containing mols percent propylene and having a molecular weight of mately 190 are in a and mixed at a temperature of until homogenous thereafter 2 parts of benzoyl peroxide added in 15 Mixing is continued at for another 15 adding 7 part3 anhydride and variable of mixing until the mass is product obtained is vulcanized in a press at 45 Proa foil according to speci tensile teats and specimens for other physical and chemical tests are rebound is determined with a Pirelli apparatus of the type of the rebound The swelling ratio is measured using benzene as a solvent a for 90 10 parts 50 parts per 100 parts per 100 parts polymer of polymer 2 Ultimate tensile 115 160 Elongation at break 515 460 Modulus at 100 14 18 Rebound at 69 66 Rebound at 81 Hardness 55 Swelling ratio 3 EXAMPLE 2 100 parte an containing 70 percent propylene and having a molecular weight of approximately are as in example for minutes at with 2 parts benzoyl peroxide and 9 parts and ly for 15 minutes at with 20 parts zinc After vulcanization in a press at for 30 a product is obtained showing the following Ultimate tensile 137 Elongation break 845 Modulus at 9 shape the stress elongation curve is reported in 3 100 parts of an a cular weight of approximately are mixed for 20 minutes at with parts tertiary butyl perbenzoate and 9 parts Successively 20 parts oxide are added in minutes at After vulcanization in a press at for 30 a product having the following characteristics is 2 Ultimate tensile 69 Elongation at break 460 Modulus at 19 ratio in at EXAMPLE 4 100 parts of the copolymer of example are treated in a roll mixer with 3 parts peroxide and 5 parts anhydride at 60 After curing in press at for 20 minutes a product having the following properties is Ultimate tensile Elongation at break 670 Modulus at Modulus at 13 Set at break Set at elongation 10 A benzene solution of the copolymer of example with a concentration of 50 is To are while This solution is stirred for hours and the solvent is then completely removed by evaporation under vacuum at product thus obtained is and homogenized in a roll mixer zinc oxide at 30 C and then cured in a press at 160 0 for 45 Varying the oxide amounts the results set forth in the following table were Ultimate Modulus Set at Set at Rebound at parts tensile at at break per strength break 58 300 15 5 68 81 1 37 5 69 80 0 23 215 12 5 0 62 77 The fact that the addition of Kino oxide causes an instead of a of the shows sine oxide takes part actively in the forming between the To a benzene solution of the copolymer of example 10 benzoyl peroxide and 20 parts maleic acid are added per 100 parts la removed by evaporation under This mixture is completely ho ogenized in a roll mixer and then cured at for 20 A product having the following properties is thus Ultimate tensile strength 2 Elongation at Modulus at Set at break 5 To a 40 benzene solution of an having iodine of kept at parts anhydride and 10 parts benzoyl peroxide per 100 parts of polymer After 10 stirring is stopped and the solvent is evaporated under reduced pressure at about The thus treated is for a few minutes at with a by weight ZnO in a laboratory roll o This mix is successively cured in a press at for 45 minutes under a pressure of about 50 From the tensile tests the following results have been To a 50 benzene solution of an a iodine number of kept at parts maleic anhydride and 10 parts benzoyl peroxide per 100 parts by evaporated under reduced pressure at about portion of the carefully dried product passing it 3 minutes laboratory roll mixer at 20 After curing in a press at for 45 a vulcanised product liaving the following tensile characteristics is tensile strength Elongation at break Modulus at Set at break Set at a Rebound at residual portion of the product mixed at for 5 minutes ZnO in a roll mixer and then cured in a press at for 45 The vulcanised product shows the following mechanical EXAMPLE a 60 solution of an copolymer a iodine number of kept at parts anhydride and 10 parts benzoyl per 100 parts are After 10 hours the solvent is evaporated under at A of the product is mixed product shows the following mechanical characteristic Ultimate tensile strength 34 Elongation at break 153 Set at break 2 Rebound at 56 Rebound at 75 The residual portion of the after a simple tion in the roll is cured in a at 1600 for 20 The vulcanized product shows the following mechanical Ultimate tensile strength 41 Elongation at break 265 Set at break 7 Rebound at 72 To a 30 benzene solution of an containing about kept at parts maleic anhydride and 10 parts benzoyl peroxide per 100 part polymer are After 20 hours the solvent is evaporated under reduced pressure at The mixed with is cured in a press at for 20 The vulcanized product shows the following 2 Ultimate tensile strength Elongation at break 313 Set at break 40 100 parts of an having a molecular weight of approximately are mixed as done in examples 2 and with 2 parts benzoyl 10 parts acryclio 20 parts The mix is vulcanized in a press at yielding product having following Ultimate tensile at break 2 at Rebound at Hardness 12 100 parts of the copolymer of example 1 are treated for about 10 minutes in a roll mixer at with 3 parts 20 of a mixture of the same copolymer with containing and 10 parts zinc oxide are then added and mixing is continued until a sheet is After curing in a press at having the following properties are ultimate elongation modulus at set time tensile at elongation minutes 30 450 12 10 45 102 13 curves are shown in 2 curing time 30 XX curing time 13 100 parts of the copolymer of example 1 treated in a roll mixer at parts benzoyl peroxide and successively with 8 parts maleic acid and e min t s 5 10 10 10 120 520 13 10 The curves are shown in 3 5 10 p EXAMPLE 14 100 parts of a propylene copolymer as used in example 11 are mixed in the way with 2 parts 9 parts znaleic acid and 10 parts The is vulcanised at for 30 yielding a produc the following Oltiiiate tensile strength 132 Elongation at break 433 Modulus at 24 Rebound at 72 Hardness 59 15 100 parts of an containing 70 propylene and having a weight of about are introduced into a two rolls kept at together with 2 parts benaoyl and mixed for 10 9 parts acid are then added and mixing is continued for about 10 The mixture thus obtained is heated in a parallel plate press at 160 C for under a pressure of 50 Half of the product thus obtained is further treated at room temperature for 5 minutes in a two until a plastic and homogenous sheet is to in 5 vulcanised in a press at for under a pressure of 70 The remaining portion of product obtained after the first in a press is at room temperature for 15 minutes in a two rolls weight of MFC carbon black and parts by weight of zinc it is vulcanized in a press for minutes at 1600 under a pressure 2 of 70 From the two vulcanised specimens for sile tests are using hollow punches according to The teats are carried out a rate of separation of the grips of 50 and at carbon black Ultimate tensile Elongation Modulus at parts by weight strength at break 0 83 38 10 11 60 48 16 100 parts by of the copolymer of example 15 are mixed for 20 minutes at 1 by weight and parts mixture is heated in a press at under a pressure 2 of 50 the product thus obtained is introduced again into the mixer at room temperature and then parts by weight antioxidant and 10 parta by zinc oxide mixture is then vulcanized in a press at for 45 minutes under a pressure of 70 tensile tests at a temperature of the elastomer following Ultimate tensile strength 100 at break 780 Modulus at 25 17 100 parts by weight of an taining polypropylene and having a iar weight of about are mixed for 20 minutes at with 1 part benzoylptroxide and 3 parts The procluot is then treated in a press at for minutes under a pressure of 50 product thus obtained is further treated in a rolls kept at about with parts parts 10 parts oxide and variable amounts of carbon Mixing is continued for about 20 minutes until the mixture is The vulcanization is carried out at for 45 minutes under a pressure of 70 Varying the amount of carbon the properties of the vulcanized product vary as Result of tensile tests Carbon black rate 50 temperature by weight ultimate tensile elongation modulus at 100 parts of an copolymer having 45 raola propylene and a molecular weight of about are mixed and parts weight and heated in a press at 160 C for 30 minutes under a pressure of 50 The product thus obtained ia further treated for 45 minutes in a whose rolls are kept at with parts by weight parts b weight stearic acid and 10 parts zino The vulcanization is carried out at for 45 minutes under a pressure of 70 From the tensile the following results are Ultimate tensile strength 110 at break 490 Modulus at 50 EXAMPLE 19 100 parts of an copolymer having a molecular weight of are mixed for 20 minutes at a temperature of with parts the ia brought to parts tertiary butyl are added and mixing is continued for 5 The mix is then heated in a press at and 70 for The product obtained is mixed for 50 minutes at with parts 6 parts stearic 45 parts carbon black and 5 parts zinc Curin is carried out at for 45 minute The cured product is tested at room with the tensile strength Elongation at break Modulus at 100 elongation H R insufficientOCRQuality

Claims (1)

1. HAVING particularly described ascertained the nature of the said invention and in what the same is to be we declare that what we claim Substantially saturated essentially consisting the product o the reaction of a polymeric selected among the substantially saturated amorphous polymers of having the formula where is a and copolymers of said with each other and with and with a conjugated having at least vinyl double or with a compound containing in its molecule at least one double bond between carbon atoms one or more functional acidic groups and capable of reacting with said polymeric substance in te presence of an activator acting with a radical Elastomers according to Claim essentially consisting of product of the reaction of a substantially amorphous polymeric selected from polymers of and the copolymers of said olefins with each other with with a compound containing in its molecule at least a double bond between carbon atoms and one or functional acidic groups and capable of reacting with the said polymeric substance in presence of an activator acting with a radical llastomers according to Claim essentially consisting of the product of the reaction of a substantiall amorphous polymeric selected from linear copolymers of propylene with ethylene and a conjugated having at least one vinyl double with a compound containing in its molecule at least one double bond between carbon atoms and one or more functional acidic and capable of reacting with said substance in the presence of an activator with radical Elastomers according to claim essentially consisting of the product of the reaction of a substance selected from the substantially amorphous colopymers of propylene with ethylene and with a compound containing in molecule at least one double bond between carbon atoms and one or more functional acidic capable of reacting with the said polymeric substance in the presence of an activator with a according to the preceding carbo in which more than of of the main chain of the linear substantially amorphous polymers or copolymers are tertiary carbon according to the preceding in which methyl is one of the substituting groups in the tertiary carbon according to the in which the compound with the polymeric substance contains a double bond conjugated with the double bonds o one or more groups 9 according to claim 2 obtained from a of with containing more than by weight aving a mined at with a Good Rebound higher than according to obtained from a propylene ethylene containing from 25 to 80 having a low initial an ultimate tensile strength higher than 80 and capable of stallizing under Elastomers according to obtained from copolymer containing from to by weigh of a diolefine selected from and Elastomers according to Claim obtained from a copolymer containing more than by ethylene and having a rebound at with a Rebound higher than according to Claim obtained from a copolymer containing from to by weight having a low initial and an ultimate strength higher 2 than 80 and capable of crystallising under Elastomers according to Claim obtained from a copolymer containing from by weight llastomers according to Claim obtained from a copolymer containing more than by weight having a rebound at 25 C with a Rebound higher than according to Claim obtained from a copolymer containing from 25 to by weight having 55 than 80 capable of crystallizing under Elastomers according to the preceding in which the compound combined with polymeric substances is selected maleic fumaric acrylic acid and methacrylic Elastomers according to the preceding taining capable of forming salts with acid Elastomers according to the preceding in which substance capable of forming with acid groups is a metal Elastomers according to Claim in which the metal oxide is selected from the group of magnesium and lead Elastomers according to in which the stance capable of forming salts with acid groups is a organic Elastomers according to in which the valent organic compound is a or a A process for preparing the elastomers to the preceding wherein the starting substance intimately mixed a radical the unsaturated compound and with the substance capable forming salts with acid groups at a temperature between and and the mixture obtained is vulcanized in a press at a temperature higher than the mixing A process according to the preceding wherein the vulcaniz ation carried out at A prooeea according to the preceding in which the ingredients are dry mixed in a A process according to Claim wherein the starting polymeric the radical initiator and the unsaturated compound are mixed in the presence of a such as benzene and the after evaporation of the is cured after addition of the substance capable of forming process according to Claim characterized in that the operation is carried out in two heating first the polymer or copolymer together with the radical initiator and the organic unsaturated compound which contains functional acidi o o groups to a temperature between 100 and 250 C until a ally complete decomposition of the radical initiator takes and then vulcanizing the product addition of a polyfunctional basic substance at a temperature comprised between A process according to Claim wherein the radical initiator is selected among organic peroxides and A process according to Claim wherein parts of radical initiator and parts of unsaturated compound are used per 100 parts by weight of the starting polymeric substance A process according to Claim wherein parts zinc oxide per 100 parts of the starting polymeric substance are added to the A process according to Claim characterized that an antioxidant and by weight of carbon black is in the vulcanisation A process according to Claim characterised in that by weight of a solid sattirated organic preferably stearic is added in the vulcanisation Agents for MZ insufficientOCRQuality