FR2734269A1 - Vulcanised thermoplastic-modified rubbers - Google Patents

Abstract

A vulcanised mixt. comprising at least one functionalised rubber (I) and at least one thermoplastic (II) in an amt. sufficient to increase the modulus at low elongation but such that the stress at rupture is not reduced by more than 10%.

Description

MODIFIED VULCANIZED RUBBERS
THERMOPLASTIC
The present invention relates to vulcanized rubbers modified with thermoplastics, and more particularly to vulcanized mixtures (i) of functionalized rubbers and (ii) thermoplastics.

 In the field of rubbers, it may be advantageous for certain applications (tires, conveyor belts, etc.) to be able to increase the breaking stress at low elongations without encountering problems of heating during installation or aging which are generated by clissic solutions such as carbon black reinforcement or a high degree of crosslinking.

 US Pat. No. 5,239,004 explains that natural rubbers, SBR (styrene-butadiene), X-NBR (carboxylated nitrile-butadiene) or EPDM (ethylene-propylene-diene) can be modified by dithodiacides and polyether block copolymers. and polyamide blocks. This modification is an increase of the module at 50, 100 and 300% elongation. The examples only relate to natural rubber which has been mixed with 1% by weight of dithiodipropionic acid. Then, in this rubber, 4% by weight is added, either of different polyether block copolymers and polyamide blocks, or of polyamide 12 and then vulcanized.

 There is a gain on the modules at 50, 100 and 300% elongation, against, however, there is a drop of 20 to 35% of the stress at break.

 The compositions of the present invention also have substantially improved 50, 100 and 300% moduli, but have better tensile strength.

 The present invention describes the improvement of certain rubber properties (reinforcement, tear resistance, etc.) without using dithiodiacide, while having a very fine and homogeneous dispersion of the thermoplastic in the rubber network.

 EP 40060 discloses thermoplastic blends of polyamides 6.66 or 6166.610 with epichlorohydrin rubbers. These are polyamide matrices containing epichlorohydrin rubber nodules. The examples compare blends with vulcanized nodules and blends with unvulcanized nodules.

 The products of the invention are not thermoplastics.

The present invention relates to the modification of rubbers with one or more thermoplastics. The thermoplastics are chosen so that they are compatible with the rubbers. This modification makes it possible to improve certain properties of the rubber while maintaining its elastomeric properties (compressive deformation at compression, elongation at break) and its resistance to oils:
- Increase in "green strength" or modulus at low elongations
raw rubber.

- Increase in modulus at low rubber elongations
vulcanized or reinforcing effect.

- Improved tear resistance and stress at the
break.

 - Increased hardness.

Moreover, in some cases, especially in the XNBR,
The incorporation of polyamide blocks and polyether block copolymer type thermoplastics, in addition to all the improvements mentioned above, provides a marked improvement in cold elongation.

The present invention is therefore a vulcanized mixture
(i) at least one functionalized rubber
(ii) and at least one thermoplastic in an amount sufficient to increase the modulus at low elongations but such that the tensile stress is not decreased by more than 10%.

 By way of example of functionalized rubbers, mention may be made of acrylic rubbers, epichlorohydrin rubbers, rubbers on which reactive groups have been grafted, such as carboxylic acid, amine or epoxy functional groups, or chlorinated rubbers or which have been chlorine.

 It is also possible to use a mixture of one of the above rubbers with an unfunctionalized rubber such as styrene-butadiene (SBR), natural rubber or ethylene-propylene-diene (EPDM).

 Among the acrylic rubbers, mention may be made of nitrile-butadiene (NBR) and hydrogenated nitrile butadiene (HNBR). Epichlorohydrin rubbers are described in the KIRK-OTHMER Encyclopedia of Chemical Technology 3rd Edition Vol. 8, Chapter ELASTOMERS pages 568 and following.

 These are polymers with epichlorohydrin units and may also contain ethylene oxide, propylene oxide or substituted propylene oxide units. Among the grafted rubbers, mention may be made of carboxylated nitrile-butadiene (X-NBR). chlorinated rubbers include chloroprene.

 Preferably, the amount of functions of the rubber is between 0.3 and 10% by weight of the weight of the functionalized rubber or of the functionalized rubber-unfunctionalized rubber group.

 Thermoplastic is defined as the product that increases the modulus of the functionalized rubber at low elongations, i.e., the modulus of the vulcanized mixture of the invention is greater than the modulus of the functionalized rubber (i) and vulcanized. This increase can be a factor of 1.5 to 3 for elongations up to 300%.

 At the same time, the thermoplastic does not affect the breaking stress by more than 10%, ie the breaking stress of the vulcanized mixture of the invention is not more than 10% lower than the breaking stress of the functionalized (i) vulcanized rubber. Most often, this constraint is even improved.

 As an example of thermoplastic, mention may be made of copolyetheresters.

These are copolymers having polyether units derived from polyetherdiols such as polyethylene glycol (PEG), polypropylene glycol (PPG) or polytetramethylene glycol (PTMG), dicarboxylic acid units such as terephthalic acid and glycol units (ethane diol) or butane diol, 14.

The linking of polyethers and diacids forms the flexible segments whereas the linking of the glycol or butanediol with the diacids forms the rigid segments of the copolyetherester.

Such copolyetheresters are described in patents EP 402 883 and
EP 405 227 the contents of which are incorporated in the present application.

 As thermoplastic, there may also be mentioned polyetherurethanes, for example those comprising diisocyanate units, units derived from polyether diols and units derived from ethane diol or butane diol, 14.

 Mention may also be made of polyesterurethanes, for example those comprising diisocyanate units, units derived from amorphous polyester diols and units derived from ethane diol or butane diol, 14.

 The thermoplastic may also be a polyamide.

Polyamide is understood to mean the condensation products:
one or more amino acids, such as aminocaproic, amino-7-heptanoic, amino-1-undecanoic and amino-1 2-dodecanoic acids of one or more lactams such as caprolactam, oenantholactam and lauryllactam;
one or more salts or mixtures of diamines such as hexamethylenediamine, dodecamethylenediamine, metaxylylenediamine, bis-p-aminocycloheximethane and trimethylhexamethylenediamine with diacids such as isophthalic, terephthalic, adipic, azelaic, suberic and sebacic acids; dodecane;
or mixtures of these monomers which leads to copolyamides.

 Polyamide blends can be used. PA-11, PA 12 and copolyamide 6 and pattern 12 (PA-6,12) are advantageously used.

 The thermoplastic may also be a mixture of polyamide and polyolefins. The polyamide may be chosen from the preceding ones.

 Polyolefins are understood to mean polymers comprising olefin units such as, for example, ethylene, propylene, butene-1 units, etc.

By way of example, mention may be made of:
polyethylene, polypropylene, copolymers of ethylene with alphaolefins. These products may be grafted with unsaturated carboxylic acid anhydrides such as maleic anhydride or unsaturated epoxides such as glycidyl methacrylate.

 copolymers of ethylene with at least one product chosen from (i) unsaturated carboxylic acids, their salts, their esters, (ii) vinyl esters of saturated carboxylic acids, (iii) unsaturated dicarboxylic acids, their salts , their esters, their hemiesters, their anhydrides (iv) the unsaturated epoxides.

 These copolymers of ethylene may be grafted with unsaturated dicarboxylic acid anhydrides or unsaturated epoxides.

 - Styrene / ethylene-butene / styrene block copolymers (SEBS) possibly maleized.

 Mixtures of two or more of these polyolefins can be used.

Advantageously used:
- polyethylene,
copolymers of ethylene and of an alpha-olefin,
copolymers of ethylene / of an alkyl (meth) acrylate,
copolymers of ethylene / an alkyl (meth) acrylate / maleic anhydride, the maleic anhydride being grafted or copolymerized,
copolymers of ethylene / an alkyl (meth) acrylate / glycidyl methacrylate, the glycidyl methacrylate being grafted or copolymerized,
polypropylene.

 It is recommended, to facilitate the formation of the polyamide matrix, and if the polyolefins have few or no functions that can facilitate compatibilization, to add a compatibilizing agent.

 The compatibilizing agent is a product known per se for compatibilizing polyamides and polyolefins.

For example:
polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-butene copolymers, all these products being grafted with maleic anhydride or glycidyl methacrylate.

the ethylene I (meth) acrylate / maleic anhydride copolymers,
The maleic anhydride being grafted or copolymerized,
ethylene / vinyl acetate / maleic anhydride copolymers,
The maleic anhydride being grafted or copolymerized.

the two previous copolymers in which maleic anhydride is replaced by glycidyl methacrylate,
the ethylene / (meth) acrylic acid copolymers, optionally their salts,
polyethylene, propylene or ethylene-propylene copolymers, these polymers being grafted with a product having a site reactive with amines; these graft copolymers are then condensed with polyamides or polyamide oligomers having a single amine end.

 These products are described in patents FR 2 291 225 and EP 342 066, the content of which is incorporated in the present application.

 The amount of polyamide forming the matrix may range from 55 to 95 parts per 5 to 45 parts of polyolefins.

The amount of compatibilizer is the amount sufficient for the polyolefin to disperse as nodules in the polyamide matrix. It can represent up to 20% of the weight of the polyolefin. These polymers are manufactured by mixing polyamide, polyolefin and optionally compatibilizer according to the usual techniques for melt blending (twin screw,
Buss, monovis).

 Advantageously, the mixture comprises a matrix of polyamide 6 (PA-6) or 66 (PA-6,6) in which are dispersed, or nodules of a mixture of low density polyethylene and ethylene copolymer of (meth) alkyl acrylate and maleic anhydride or glycidyl methacrylate, polypropylene nodules.

 Such products are described in US Pat. Nos. 5,070,145 and EP 564,338.

 In the case of polypropylene, there is added a unit which is advantageously an ethylene / propylene copolymer which is predominantly in number of propylene units, grafted with maleic anhydride, and then condensed with monoamines of caprolactam oligomers.

 These polyamide and polyolefin blends can be plasticized and optionally contain fillers such as carbon black, etc.

 Such polyamide and polyolefin blends are described in US Pat. No. 5,342,886.

 By way of example of thermoplastic, mention may also be made of polymers with polyamide blocks and polyether blocks.

Polymers with polyamide blocks and polyether blocks result from the copolycondensation of polyamide sequences with reactive ends with polyether sequences with reactive ends, such as, inter alia:
1) Polyamide sequences with diamine chain ends with
polyoxyalkylene sequences with dicarboxylic chain ends.

2) Polyamide sequences with dicarboxylic chain ends with
Polyoxyalkylene sequences with diamine chain ends obtained
by cyanoethylation and hydrogenation of polyoxyalkylene blocks
alpha-omega dihydroxy aliphatic called polyetherdiols.

3) Polyamide sequences with dicarboxylic chain ends with
polyetherdiols, the products obtained being, in this particular case,
polyetheresteramides.

 The polyamide sequences with dicarboxylic chain ends result, for example, from the condensation of alpha-omega-aminocarboxylic acids of lactams or of dicarboxylic and dicarboxylic acids in the presence of a dicarboxylic acid chain-limiting agent. Advantageously, the polyamide blocks are made of polyamide-12.

 The number-average molar mass Mn of the polyamide sequences is between 300 and 15,000 and preferably between 600 and 5,000. The mass Mn of the polyether blocks is between 100 and 6,000 and preferably between 200 and 3,000.

 Polymers with polyamide blocks and polyether blocks may also comprise randomly distributed units. These polymers can be prepared by the simultaneous reaction of the polyether and the precursors of the polyamide blocks.

 For example, polyetherdiol, a lactam (or an alpha-omega amino acid) and a chain-limiting diacid can be reacted in the presence of a little water. A polymer having essentially polyether blocks, polyamide blocks of very variable length, but also the various reagents reacted randomly are obtained which are distributed statistically along the polymer chain.

 These polymers with polyamide blocks and polyether blocks, whether they come from the copolycondensation of previously prepared polyamide and polyether blocks or from a one-step reaction, have, for example, Shore D durations which can be between 20 and 75 and advantageously between 30 and 75. and 70 and an intrinsic viscosity between 0.8 and 2.5 measured in metacresol at 250 C for an initial concentration of 0.8 9/100 ml.

 Whether the polyether blocks are derived from polyethylene glycol, polyoxypropylene glycol or polyoxytetramethylene glycol, they are either used as they are and copolycondensed with polyamide blocks having carboxylic ends, or they are aminated to be converted into polyether diamines and condensed with polyamide blocks. carboxylic ends. They can also be mixed with polyamide precursors and a chain limiter to make the polyamide block and polyether block polymers having statistically distributed patterns.

 Polymers with polyamide blocks and polyethers are described in US Pat. Nos. 4,331,786, 4,155,475, 4,195,155, 4,839,441, 4,884,014, 4230838 and 4332920.

 The polyether may be for example a polyethylene glycol (PEG), a polypropylene glycol (PPG) or a polytetraethylene glycol (PTMG). The latter is also called polytetrahydrofuran (PTHF).

 Whether the polyether blocks are in the chain of the polyamide block polymer and polyether blocks in the form of diols or diamines, they are called by simplification PEG blocks or PPG blocks or PTMG blocks.

ou encore du tétraméthylène glycol ( < (-CH2)4-)
De préférence, le polymère à blocs polyamides et blocs polyéther comprend un seul type de bloc polyamide et un seul type de blocs polyéther. On utilise avantageusement des polymères à blocs PA-12 et blocs PTMG.It would not be departing from the scope of the invention if the polyether blocks contained different units such as units derived from ethylene glycol C2H4-), propylene glycol.

or tetramethylene glycol (<(-CH2) 4-)
Preferably, the polyamide block and polyether block polymer comprises a single type of polyamide block and a single type of polyether block. PA-12 block polymers and PTMG blocks are advantageously used.

 It is also possible to use a mixture of these two polymers with polyamide blocks and polyether blocks.

Advantageously, the polyamide block and polyether block polymer is such that the polyamide is the major constituent by weight, that is to say the amount of polyamide which is in the form of blocks and that which is optionally distributed statistically in the chain is 40% by weight or more of the polyamide block and polyether block polymer. Advantageously, the amount of polyamide and the amount of polyether are in the ratio (polyamide / polyether) 1/1 to 3/1 and preferably:
This thermoplastic may also include plasticizers, anti-oxidants or UV stabilizers

 The thermoplastic may also be a mixture of at least one polymer with polyamide blocks and polyether blocks and at least one polyolefin. This polyolefin and optionally a compatibilizing agent may be chosen from those mentioned above with regard to mixtures of polyamides and polyolefins.

 The thermoplastic may also be a mixture of polyamide and polyamide block polymer and polyether blocks, these products may be chosen from the products already mentioned above.

 The thermoplastic may also be a polymer with polyamide blocks and amorphous polyester blocks. It can be prepared by condensation of polyamide blocks with carboxylic acid ends with polyester diols.

 The preparation of the modified rubber of the invention can be carried out in one or two stages, in fact the incorporation of the thermoplastic can be carried out before or during the formulation of the rubber.

 1 to 60%, preferably 5 to 20% of thermoplastic are incorporated by kneading in one of the rubbers mentioned above.

 The thermoplastic is incorporated at a temperature sufficient to be in the molten state.

 The mixing time is between 1 and 10 minutes and preferably between 5 to 8 minutes.

 The alloy obtained is a rubber matrix and can then be formulated on cylinders as a conventional rubber, with the advantage over the starting rubber of an easier implementation due to the increase of the green strength or modulus to low elongations by the incorporation of thermoplastics.

Depending on the intended applications, the rubber may advantageously be formulated with carbon black or clear fillers, with tackifying resins, processing aids such as polyethylene glycol,
Stearic acid, Zinc oxide ..

 The vulcanization of these formulations can be done by sulfur systems in the presence of accelerators or not, by peroxides with or without coagent or by formophenolic resins. The choice of the vulcanization system depends on the nature of the rubber and the desired vulcanization kinetics at the processing temperatures.

 Once vulcanized, a significant increase in modulus at low elongations of the modified rubber is observed. This reinforcing effect of thermoplastic can be interesting in the field of tires, conveyor belts ... where a significant resistance of the material is sought.

 The vulcanization systems are known per se, for example those described in patent EP 550 346, the content of which is incorporated by reference in the present application.

Examples
In the following examples, the ECOT rubber is a patterned polymer:

 The HNBR used to make the examples is ZETPOL 2000 from Nippon Zeon.

 The XNBR is the PX 7439, quality powder NX775 from Good Year.

 ECOT is HYDRIE T70 from Nippon Zeon.

 The polyamide block ether 1 used consists of 50% of polyamide 12 (Mn = 1000) and 50% of polytetramethylene glycol (Mn = 1000) sequences and is characterized by a melting point of 147 ° C. and an intrinsic viscosity of 1.60, measured at a concentration of 0.5 9/100 g in metacresol at 25 ° C.

 The polyamide block ether 2 used consists of 86% of polyamide 12 (Mn = 4000) and 14% of polytetramethylene glycol (Mn = 1000) sequences and is characterized by a melting point of 1700C and an intrinsic viscosity of 1 , 40, measured at the concentration of 0.5 9/100 g in metacresol at 25 C.

 Mechanical properties.

Example I
In a Brabender kneader, kneaded for 7 to 8 minutes at 165 ° C., 90 parts of HNBR rubber and 10 parts of polyamide ether block 1. The modified rubber is then formulated at 30 ° C. on a roll mill according to the following composition. in shares:
Zetpol 2000 100
Pebax 1 11.1
Calcined kaolin 30
Silane 1
PEG 4000 1
Stearic acid 0.55
Zinc oxide 3.33
Perkadox 1440 6.7
TiO2 5
Example 2
The procedure is the same as in Example 1 by incorporating 20 parts of Pebax 1 in the HNBR during the first step and following the composition below for the second formulation step ::
Zetpol 2000 100
Pebax 1 25
Calcined kaolin 30
Silane 1
PEG 4000 1
Stearic acid 0.65
Zinc oxide 3.75
Perkadox 1440 7.5
TiO2 5
The mixtures of Examples 1 and 2 as well as a control containing no Pebax 1 were vulcanized in static press at 1800 ° C. at 90 bars for 12 minutes to make plates 2 mm thick. the mechanical properties were measured at 23 C on specimens made from these plates.

<Tb>

Sample <SEP> Module <SEP> Module <SEP> Module <SEP> Constraint <SEP> Resistance <SEP> Elongation
<tb><SEP> 50th <SEP> MPa <SEP> 100 MPa <SEP> 300XMPa <SEP> rupture <SEP> tearing <SEP> rupture <SEP>%
<tb><SEP> MPa <SEP> N / mm
<tb><SEP> Control <SEP> 1.0 <SEP> 1.3 <SEP> 3.7 <SEP> 12.4 <SEP> 28.7 <SEP> 742
<tb><SEP> without
<tb><SEP> Pebaxi <SEP>
<tb><SEP> Example <SEP> 1 <SEP> 1.3 <SEP> 1.8 <SEP> 4.9 <SEP> 13.1 <SEP> 31.8 <SEP> 726
<tb><SEP> Example <SEP> 2 <SEP> 1.8 <SEP> 2.4 <SEP> 5.5 <SEP> 14.8 <SEP> 38.4 <SEP> 733
<Tb>
Table 1: Properties of HNBR Modified by Pebax 1
Exemole 3
In a Brabender kneader, kneading is carried out for 7 to 8 minutes at 165 ° C., 90 parts of XNBR rubber and 10 parts of polyamide ether block 1. The modified rubber is then formulated at 30 ° C. on a roll mill according to the following composition. in shares:
XNBR PX7439 100
Pebax 1 11.1
Calcined kaolin 30
Silane I
PEG I
Stearic acid 0.55
Zinc oxide 3.33
Perkadox 1440 0.83
TiO2 5
Example 4
The procedure is the same as in Example 3 by incorporating 20 parts of Pebax 1 into the XNBR during the first stage and following the composition below for the second stage of formulation ::
XNBR PX7439 100
Pebax 1 25
Calcined kaolin 30
Silane A187 1
PEG 4000 1
Stearic acid 0.65
Zinc oxide 3.75
Perkadox 1440 0.94
TiO2 5
The mixtures of Examples 3 and 4 as well as a control containing no pebax 1 were vulcanized in a static state on a press at 1800 ° C. at 90 bars for 12 minutes to make plates 2 mm thick. the mechanical properties were measured at 23 ° C. and -35 ° C. on specimens made from these plates.

<tb> Sample <SEP> Module <SEP> Module <SEP> Module <SEP> Constraint <SEP> Resistance <SEP> Extension- <SEP> Extension
<tb><SEP> 50% <SEP> 100% <SEP> 300eMoM <SEP> rupture <SEP> tears <SEP> ment <SEP> ment
<tb><SEP> MPa <SEP> MPa <SEP> Pa <SEP> MPa <SEP> nt <SEP> N / mm <SEP> rupture <SEP> rupture
<tb><SEP>%<SEP> a-35 C <SEP>% <SEP> to <SEP> 230C
<tb><SEP> Control2 <SEP> 1.8 <SEP> 2.9 <SEP> 9.8 <SEP> 14.5 <SEP> 33.8 <SEP> 25 <SEP> 492
<tb><SEP> without
<tb><SEP> Pebaxi <SEP>
<tb><SEP> Example <SEP> 3 <SEP> 2.1 <SEP> 3.4 <SEP> 10.3 <SEP> 13.8 <SEP> 34.2 <SEP> 34 <SEP> 428
<tb><SEP> Example <SEP> 4 <SEP> 2.8 <SEP> 4.2 <SEP> 10.6 <SEP> 15.7 <SEP> 38.3 <SEP> 64 <SEP> 498
<Tb>

Table 2: Properties of XNBR modified by Pebax 1
Example 5
The formulation of this example was carried out directly on a roll mill according to the following composition in parts which corresponds to a 95% content of HNBR for 5% of Pebax 2:
Zetpol 2000 100
Pebax 2 5.5
Calcined kaolin 30
Silane A187 I PEG 4000 I
Naugard 445 2
Stearic acid 0.5
Zinc oxide 3
Perkadox 1440 6
TiO2 5
Example 6
The procedure is as in Example 5 following the composition below (90% HNBR 110% Pebax 2) ::
Zetpol 2000 100
Pebax 2 11.1
Calcined Kaolin Silane A1 I
PEG 4000 1
Naugard 445 2
Stearic acid 0.55
Zinc oxide 3.3
Perkadox 1440 6.7
TiO2 5
EXAMPLE 7
The procedure is as in Example 5 following the composition below (80% HNBR 120% Pebax 2):
Zetpol 2000 100
Pebax 2 25
Calcined Kaolin 30 Silane I
PEG 4000 I
Naugard 445 2
Stearic acid 0.65
Zinc oxide 3.75
Perkadox 1440 7.5
TiO2 5
The increase in green strength and the processing aid aspect were demonstrated on the formulations of Examples 5, 6 and 7 by low elongation modulus measurements prior to vulcanization.

<Tb>

Sample <SEP> ModuleS0% <SEP> Module100% <SEP> Module300K <SEP>
<tb><SEP> MPa <SEP> MPa <SEP> MPa
<tb><SEP> Control3 <SEP> 0.82 <SEP> 0.85 <SEP> 1.06
<tb> without <SEP> Pebax2
<tb><SEP> Example <SEP> 5 <SEP> 0.89 <SEP> 0.87 <SEP> 0.90
<tb><SEP> Example <SEP> 1.13 <SEP> 1.21 <SEP> 1.58
<tb><SEP> Example <SEP> 7 <SEP> 2.43 <SEP> 2.84 <SEP> 3.03
<Tb>
Table 3: Raw properties of modified HNBR with Pebax 2
The mixtures of Examples 5, 6 and 7 as well as a control containing no Pebax 2 were then vulcanized in a static state at 180 ° C. under 90 bar for 12 minutes, to make plates 2 mm thick. the mechanical properties were measured at 23 C on specimens made from these plates.

<Tb>

<SEP> Sample <SEP> Module <SEP> Module <SEP> Module <SEP> Constraint <SEP> Elongation <SEP> Hardness <SEP> DRC
<tb><SEP> 50% <SEP> MPa <SEP> 100% <SEP> 300 <SEP>% MPa <SEP> Breaking <SEP> MPa <SEP> Breaking <SEP>% <SEP> Shore <SEP> A <SEP> 22h. <SEP> iOO "C <SEP>
<tb><SEP> MPa
<tb><SEP> Control <SEP> 1.06 <SEP> 1.32 <SEP> 3.63 <SEP> 12.92 <SEP> 641 <SEP> 56 <SEP> 32
<tb> without <SEP> Pebax2
<tb><SEP> Example <SEP> 5 <SEP> 1.21 <SEP> 1.64 <SEP> 5.85 <SEP> 12.55 <SEP> 592 <SEP> 60 <SEP> 31.5
<tb><SEP> Example <SEP> 6 <SEP> 1.47 <SEP> 2.09 <SEP> 7.16 <SEP> 14.23 <SEP> 541 <SEP> 65 <SEP> 30.5
<tb><SEP> Example <SEP> 2.35 <SE> 3.41 <SEP> 9.53 <SE> 13.90 <SE> 442 <SE> 75 <SEP> 32
<Tb>
Table 4: Properties of the modified HNBR by Pebax 2
Example 8
The formulation of this example was carried out directly on a roll mill according to the following composition in parts, which corresponds to 95% of XNBR for 5% of Pebax 2:
XNBR PX7439 110
Pebax 2 5.5
Calcined Kaolin Silane I
PEG 1
Naugard 445 2
Stearic acid 0.5
Zinc oxide 3
Perkadox 1440 0.8
TiO2 5
Example 9
The procedure is the same as in Example 8 following the composition below (90% XNBR / 10% Pebax 2) ::
XNBR PX7439 110
Pebax 2 11.1
Calcined Kaolin Silane I
PEG 4000 1
Naugard 445 2
Stearic acid 0.55
Zinc oxide 3.3
Perkadox 1440 0.83
TiO2 5
Example 10
The procedure is as in Example 8 following the composition below (80% XNBR / 20% Pebax 2):
XNBR PX7439 110
Pebax 2 25
Calcined kaolin 20
Silane A187 I
PEG 4000 1
Naugard 445 2
Stearic acid 0.65
Zinc oxide 3.75
Perkadox 1440 0.94
TiO2 5
The mixtures of Examples 8, 9 and 10 as well as a control containing no pebax 2 were vulcanized in a pressurized state at 180 ° C. at 90 bars for 12 minutes to make plates 2 mm thick. the mechanical properties were measured at 23 C on specimens made from these plates.

<Tb>

Sample <SEP> Module <SEP> Module <SEP> Module <SEP> Constraint <SEP> Extension- <SEP> Hardness <SEP> DRC
<tb><SEP> 50% <SEP> 100% <SEP> 300% <SEP> rupture <SEP> ment <SEP> shore <SEP> A <SEP> 22h, <SEP>
<tb><SEP> MPa <SEP> MPa <SEP> MPa <SEP> MPa <SEP> rupture <SEP> 100 C <SEP>
<tb><SEP> Control4 <SEP> 1.08 <SEP> 1.51 <SEP> 4.36 <SEP> 11.51 <SEP> 611 <SEP> 65 <SEP> 27.5
<tb> without <SEP> Pebax2
<tb><SEP> Example <SEP> 8 <SEP> 1.33 <SEP> 1.99 <SEP> 6.00 <SEP> 12.74 <SEP> 566 <SEP> 68 <SEP> 1 <SEP> 30
<tb><SEP> Example <SEP> 9 <SEP> 1.77 <SEP> 2.84 <SEP> 8.30 <SEP> 15.05 <SEW> 534 <SEP> 70 <SEP> 34
<tb> Example <SEP> 10 <SEP> 2.85 <SEP> 4.63 <SEP> 10.87 <SEP> 17.58 <SEP> 492 <SEP> 75 <SEP> 36
<Tb>
Table 5: Properties of XNBR Modified by Pebax 2
Example
The formulation of this example was carried out directly on a roll mixer according to the following composition in parts which corresponds to 95% of ECOT for 5% of Pebax 2:
HYDRIN T70 100
Pebax 2 5.5
Calcined kaolin 30
Silane A1 1
PEG 4000 I
Naugard 445 2
Stearic acid 1
Maglite D 3
Zisnet F 1.2
CaC03 5
TiO2 5
EXAMPLE 12
We proceed in the same way as in Example 11 by following the composition below (90% ECOT II 0% Pebax 2) ::
HYDRIN T70 100
Pebax 2 11.1
Calcined kaolin 30
Silane 1
PEG 4000 1
Naugard 445 2
Stearic acid 1
Maglite D 3
Zisnet F 1.5
CaC03 5
TiO2 5
Example 13
We proceed in the same way as in Example 11 by following the composition below (80% ECOT / 20% Pebax 2) ::
HYDRIN T70 100
Pebax 2 25
Calcined kaolin 30
Silane A187 1
PEG 4000 1
Naugard 445 2
Stearic acid 1
Maglite D 3
Zisnet F 1.7
CaC03 5
TiO2 5
The mixtures of Examples 11, 12 and 13 as well as a control containing no pebax 2 were vulcanized in static press at 1800 ° C. at 90 bars for 12 minutes to make plates 2 mm thick. the mechanical properties were measured at 23 C on specimens made from these plates.

<Tb>

Sample <SEP> Module <SEP> Module <SEP> Module <SEP> Contrain <SEP> Extension- <SEP> Hardness <SEP> DRC <SEP>%
<tb><SEP> 50% <SEP> 100 <SEP>% <SEP> 300 <SEP>% <SEP><SEP><SEP> Shore <SEP> A <SEP> 22h, <SEP>
<tb><SEP> MPa <SEP> MPa <SEP> MPa <SEP> Rupture <SEP> Rupture <SEP>% <SEP> 1oooc <SEP>
<tb><SEP> MPa
<tb><SEP> Control <SEP> 5 <SEP> 0.89 <SEP> 1.50 <SEP> 4.97 <SEP> 5.74 <SEP> 337 <SEP> 49 <SEP> 8
<tb> withoutPebax <SEP> 2
<tb> Example <SEP> 11 <SEP> 1.24 <SEP> 2.29 <SEP> - <SEP> 5.54 <SEP> 225 <SEP> 57 <SEP> 13
<tb> Example <SEP> 12 <SEP> 2.00 <SEP> 3.80 <SEP> - <SEP> 6.59 <SEP> 183 <SEP> 65 <SEP> 23
<tb> Example <SEP> 13 <SEP> 3.05 <SEP> 5.27 <SEP> - <SEP> 7.62 <SEP> 166 <SEP> 77 <SEP> 32.5
<Tb>
Table 6: Properties of ECOT Modified by Pebax 2
Oil resistance
The resistance to oils was measured according to the principle of the ASTM standard
D471 by dipping the mixtures of Examples 5,6,7,8,9,10,11,12,13 and their control in ASTM 3 oil for 7 days at 100 ° C. and measuring their% swelling.

<Tb>

<SEP> Reference <SEP> Composition <SEP>% <SEP> of <SEP> swelling
<tb><SEP> Control <SEP> 3 <SEP> 100% <SEP> HNBR <SEP> 21
<tb><SEP> Example <SEP> 5 <SEP> 95% <SEP> HNBR <SEP> i <SEP> 5% <SEP> Pebax <SEP> 2 <SEP> 20
<tb><SEP> Example <SEP> 6 <SEP> 90% <SEP> HNBR <SEP> / <SEP> 10% <SEP> Pebax <SEP> 2 <SEP> 19
<tb><SEP> Example <SEP> 7 <SEP> 80% <SEP> HNBR <SEP> / <SEP> 20% <SEP> Pebax <SEP> 2 <SEP> 17
<tb><SEP> Control <SEP> 4 <SEP> 100% <SEP> XNBR
<tb><SEP> Example <SEP> 8 <SEP> 95% <SEP> XNBR <SEP> I <SEP> 5% <SEP> Pebax <SEP> 2 <SEP> 18
<tb><SEP> Example <SEP> 9 <SEP> 90% <SEP> XNBR <SEP> / <SEP> 10% <SEP> Pebax <SEP> 2 <SEP> 17.5
<tb> Example <SEP> 10 <SEP> 80% <SEP> XNBR <SEP> / <SEP> 20% <SEP> Pebax <SEP> 2 <SEP> 16
<tb><SEP> 15
<tb><SEP> LEDs <SEP> 100% <SEP> ECOT <SEP> 11 <SEP>
<tb> Example <SEP> 11 <SEP> 95% <SEP> ECOT <SEP> / <SEP> 5% <SEP> Pebax <SEP> 2 <SEP> 10.5
<tb> Example <SEP> 12 <SEP> 90% <SEP> ECOT <SEP> / <SEP> 10% <SEP> Pebax <SEP> 2 <SEP> 10
<tb> Example <SEP> 13 <SEP> 80% <SEP> ECOT <SEP> / <SEP> 20% <SEP> Pebax <SEP> 2 <SEP> 9
<Tb>
Table 7: oil resistance of modified rubbers.

Claims (5)

claims 1. Vulcanized mixture:  (i) at least one functionalized rubber and  (ii) at least one thermoplastic in an amount sufficient to  increase the modulus at low elongations but such that the  stress at break is not decreased by more than 10%. Mixture according to claim 1 wherein the rubber  functionalized is H-NBR, X-NBR or rubber  epichlorohydrin. 3. Mixture according to claim 1 or 2 wherein the  thermoplastic is a polymer with polyamide blocks and blocks  polyether. 4. Mixture according to any one of the preceding claims  in which the amount of thermoplastic is 5 to 20% by weight  functionalized rubber and thermoplastic mixture. 5. Process for manufacturing the mixture according to any one of  preceding claims in which the rubber is blended  functionalized and the thermoplastic until a mixture  homogeneous, then proceed to vulcanization.