EP3551669A1

EP3551669A1 - Hydrogenated nitrile-diene-carboxylic acid ester copolymers

Info

Publication number: EP3551669A1
Application number: EP17807728.5A
Authority: EP
Inventors: Hiyam SALEM; Karola Schneiders; Susanna Lieber
Original assignee: Arlanxeo Deutschland GmbH
Current assignee: Arlanxeo Deutschland GmbH
Priority date: 2016-12-09
Filing date: 2017-11-09
Publication date: 2019-10-16
Also published as: US20190284374A1; WO2018103989A1; CN110023343B; TW201835126A; JP2020503397A; KR20190086031A; EP3333196B1; EP3333196A1; CN110023343A; BR112019011143A2; CA3045941A1; JP7174701B2; KR102488924B1; US11021596B2

Abstract

The invention relates to hydrogenated nitrile-diene-carboxylic acid ester copolymers, to the production thereof, to vulcanizable mixtures containing hydrogenated nitrile-diene-carboxylic acid ester copolymers and to the production thereof, and to vulcanized material based on hydrogenated nitrile-diene-carboxylic acid ester copolymers and use thereof in belts.

Description

Hydrogenated nitrile-diene carboxylic acid ester copolymers

The present invention relates to hydrogenated nitrile-diene carboxylic acid ester copolymers, their preparation, vulcanizable mixtures containing hydrogenated nitrile-diene carboxylic acid ester copolymers and their preparation, and vulcanizates based on hydrogenated nitrile-diene carboxylic acid ester copolymers and their use in belts.

For the purposes of this application, nitrile-butadiene copolymer (nitrile rubber, also abbreviated to "NBR") is understood as meaning rubbers which are co-, ter- or quaternary polymers of at least one .alpha.,. Beta.-ethylenically unsaturated nitrile, at least one conjugated diene and optionally one or more other copolymerizable monomers.

Hydrogenated nitrile-butadiene copolymer ("HNBR") is understood as meaning corresponding co-, ter- or quaternary polymers in which the sum of the C =C double bonds of the copolymerized diene units is completely or partially hydrogenated.

Both NBR and HNBR have been firmly established in the field of specialty elastomers for many years. They have an excellent property profile in terms of excellent oil resistance, good heat resistance and excellent resistance to ozone and chemicals, the latter being even more pronounced in the case of HNBR than NBR. NBR and HNBR also have very good mechanical and performance properties. For this reason, they are widely used in a variety of applications and are used, for example, for the production of belts, gaskets, hoses and damping elements in the automotive sector, stators, borehole seals and valve seals in the field of oil extraction, as well as for many parts of the electrical industry, the machinery and shipbuilding. For many applications, it is crucial that the vulcanizate based on HNBR has a low glass transition temperature (Tg), so that the functionality of the vulcanizate is ensured even at low temperatures. In addition, it is also necessary that the vulcanizate in contact with, for example, oil or fuels, the lowest possible swelling, otherwise the vulcanizate increases in volume and is no longer operational.

Commercially available are a variety of different types of HNBR, depending on the application by different monomers, molecular weights and polydispersities and, consequently, by different mechanical and Characterize physical properties. In addition to the standard types, especially special grades, which are characterized by contents of special termonomers or special functionalizations, are increasingly in demand.

As specific termonomers, for example, α, β-ethylenically unsaturated carboxylic acids are known (inter alia, acrylic acid and methacrylic acid). Terpolymers containing these termonomers are grouped together as HXNBR where the "X" is the acid group, which includes, for example, monocarboxylic acids, dicarboxylic acids and dicarboxylic acid monoesters (including monomethyl maleate or monobutyl maleate).

Also known are terpolymers with α, β-ethylenically unsaturated carboxylic ester units (including monocarboxylic esters such as methyl acrylate and butyl acrylate or dicarboxylic acid monoesters such as monobutyl maleate).

EP-A-1852447 discloses a highly saturated nitrile group-containing terpolymer rubber having 10 to 40% by weight of α, β-ethylenically unsaturated nitrile units, 10 to 60% by weight of α, β-ethylenically unsaturated carboxylic ester units, such as butyl acrylate, and 20 to 70% by weight of a conjugated diene unit comprising a vulcanizate having balanced properties. The examples explicitly disclosed have HNBR terpolymer with acrylonitrile units ranging from 5 to 45 weight percent (6 to 50 mole percent) acrylonitrile units, 40 to 75 weight percent (43 to 77 mole percent) butadiene units and 5 to 38% by weight (2 to 20 mole%) of butyl acrylate units with a TR 10 down to -41 ° C. There is no disclosure of the swelling behavior of the terpolymers in IRM 903. Polyethylene glycol acrylates (PEG acrylates) are not explicitly disclosed as α, β-ethylenically unsaturated carboxylic acid ester units.

EP-A-1247835 discloses a nitrile group-containing highly saturated copolymer containing (a) 10 to 40% by weight of α, β-ethylenically unsaturated nitrile units, (b) 10 to 60% by weight of α, β-ethylenically unsaturated carboxylic acid ester units, (c) 0.01 to 21 wt .-% of conjugated diene units and 14 to 69.99 wt .-% of saturated conjugated diene units, wherein the sum of the monomer units (c) and (d) 20 to 70 wt .-% and the ratio of the monomer units (d) / [(c) + (d)] is at least 70% by weight and the difference between the extrapolated starting temperature of the glass transition (Tig) and the extrapolated end temperature of the glass transition (Teg) is not greater than 10 ° C. The examples explicitly disclosed have HNBR terpolymers with 20 wt% (23 to 29 mol%) of acrylonitrile, 30 to 60 wt% (42 to 68 mol%) butadiene, and 20 to 50 wt% (10 to 30 mol%) of butyl acrylate. The vulcanized products of the copolymer rubbers have good cold resistance, oil resistance and good dynamic properties. Explicit embodiments of HNBR terpolymers with 15 to 49.9 wt.% PEG acrylate units are not disclosed.

Furthermore, EP-A-1243602 discloses a terpolymer comprising (a) 0 to 20% by weight of 1, 3-butadiene units, (b) 0 to 50% by weight of saturated 1,3-butadiene units, (c) 40 to 50% by weight of α, β-ethylenically unsaturated nitrile units, and (d) 10 to 35% by weight and at least 8% by mole of other monomer units, the sum of the 1,3-butadiene units (a) and the saturated 1, 3-butadiene units (b) is in the range of 30 to 50% by weight. The other monomer unit may be u.a. to act unsaturated carboxylic acid ester. This nitrile group-containing highly saturated copolymer rubber has good oil resistance in the vulcanized product. Explicit HNBR terpolymers with hydrogenated PEG acrylate units are not disclosed. Explicit examples are found only with butyl acrylate.

Also known are nitrile-diene copolymers with PEG acrylate units.

EP-A-2868677 discloses a nitrile group-containing copolymer having from 1 to 9% by weight monocarboxylic acid monoester units having a glass transition temperature of less than -20 ° C and an oil swell of less than 20%. It explicitly discloses terpolymers of 4.8% by weight and 7.7% by weight of methoxyethyl acrylate, i. PEG-1 acrylate, or with 4, 1 wt .-% PEG-5-methacrylate. EP-A-2868277 does not disclose copolymers having at least 15 weight percent PEG acrylate units with two or more ethylene glycol repeating units.

EP-A-2868676 discloses a nitrile group-containing copolymer having 1 to 9% by weight of α, β-ethylenically unsaturated carbonyl group-containing monomer units. As explicit examples hydrogenated terpolymers with PEG-1 1 monomers are disclosed. However, EP-A-2868276 does not disclose copolymers having at least 15% by weight of PEG acrylate having from 2 to 12 ethylene glycol repeating units.

Terpolymers are often no longer sufficient to more precisely set the desired polymer properties. Quaternary polymers, i. Polymers of four monomer units, are increasingly being used. Quaternary polymers with α, β-ethylenically unsaturated carboxylic acids and α, β-ethylenically unsaturated carboxylic acid esters are known.

EP-A-2392599 discloses an at least partially hydrogenated nitrile-butadiene copolymer containing 5 to 60% by weight of α, β-ethylenically unsaturated nitrile units, 20 to 83.9% by weight of conjugated diene units, 0.1 to 20% by weight of dicarboxylic acid monoester units, 1 1 to 50% by weight

Alkoxyalkyl (meth) acrylic acid ester units having 2 to 8 carbon atoms. Table 2 describes inter alia quaternary polymers having a content of 21, 3 or 24.8 wt .-% (27 to 30 mol .-%) of acrylonitrile, 46.6 and 47.3 wt .-% (57 mol Butadiene, 4.5 to 5 wt .-% (2 mol .-%) of mono-n-butyl maleate and 23.0 and 27, 1 wt .-% (1 1 to 14 mol .-% ) Methoxyethyl acrylate. The vulcanizates prepared from these hydrogenated nitrile-butadiene copolymers have good TR10 values. No indication of the swelling behavior in IRM 903 or the glass transition temperature Tg is disclosed. HNBR terpolymers with polyethylene glycol acrylate units are not explicitly disclosed. Likewise, no ter or quaternary polymers having less than 20 weight percent nitrile units are disclosed.

JP-A-2012-03131 1 describes a nitrile group-containing, highly saturated copolymer rubber comprising (a) from 10.0 to 40.0% by weight of α, β-ethylenically unsaturated nitrile units, (b) from 5.5 to 10.0% by weight % α, β-ethylenically unsaturated dicarboxylic acid monoester units, (c) 1 1, 0 to 30.0% by weight

Alkoxyalkyl (meth) acrylate units having alkoxyalkyl groups of 2 to 8 carbon atoms; and (d) 20.0 to 73.5 weight percent of conjugated diene units wherein at least a portion of the conjugated diene units are hydrogenated. HNBR terpolymers with polyethylene glycol acrylate units are not explicitly disclosed.

WO-A-2015/146650 discloses nitrile group-containing highly saturated copolymers containing less than 30% by weight of nitrile units, (b) conjugated diene units, (c) α, β-ethylenically unsaturated dicarboxylic acid monoester units and (d) methoxyethyl acrylate. The examples explicitly disclose a quaternary polymer containing 24% by weight of acrylonitrile units, 46% by weight of butadiene units, 23% by weight of methoxyethyl acrylate and 7% by weight of mono-n-butyl maleate. HNBR quaternary polymers with

Polyethylene glycol acrylate units are not explicitly disclosed.

WO-A-2016/059855 discloses copolymers comprising (a) 0, 1 to 15% by weight of α, β-ethylenically unsaturated nitrile units, (b) 1 to 10% by weight of α, β-ethylenically unsaturated dicarboxylic acid monoester units, (c ) 40 to 75% by weight of α, β-ethylenically unsaturated monocarboxylic acid ester units and (d) 20 to 58.9% by weight of diene units. HNBR terpolymers with polyethylene glycol acrylate units are not explicitly disclosed. The choice of monomer or monomers and the amount of monomers used has a decisive influence on the polymer properties and is thus not easily predictable.

The hitherto known hydrogenated nitrile-butadiene-carboxylic acid ester copolymers containing nitrile units and diene units as Termonomereinheiten exclusively monocarboxylic acids, carboxylic acid esters such as butyl acrylate or monobutyl maleate, PEG-1 - acrylate or small amount of PEG acrylate meet the requirement of a lower glass transition temperature of less as -40 ° C and a swelling of 51% or less in the vulcanizate unsatisfactory.

Accordingly, it has been an object of the present invention to provide a hydrogenated nitrile-diene copolymer which results in an improved glass transition temperature of less than -40 ° C, preferably -44 ° C or less, in a vulcanizate and at the same time satisfying 51% swelling properties. or less. Another object was to provide HNBR copolymers which contain very little gel content. In addition, it was a further object that the dynamic and mechanical properties of the provided HNBR copolymer are similarly balanced as in previously known HNBR polymers. It was also an object to provide an HNBR copolymer, in the production of which a small amount of substances harmful to health and the environment is used.

The solution of the object and subject of the present invention is now a hydrogenated nitrile-diene carboxylic acid ester copolymer containing

(a) 0.1 to 20 wt .-%, preferably 1 to 19 wt .-% and particularly preferably 8 to 18 wt .-% of at least one α, β-ethylenically unsaturated nitrile unit,

(b) 15 to 74.9% by weight, preferably 21 to 73% by weight and particularly preferably 27 to 65% by weight of at least one conjugated diene unit and

(C) 25 to 65 wt .-%, preferably 26 to 60 wt .-% and particularly preferably 27 to 55 wt .-% of at least one α, β-ethylenically unsaturated carboxylic ester unit, wherein at least 15 wt .-%, preferably at least 20 Wt .-% of α, β-ethylenically unsaturated carboxylic acid ester units (c) based on the total amount of all monomer units of 100% by weight, of a PEG acrylate (d) of the general formula (I)

Formula (I) are derived, wherein

R is branched or unbranched Ci-C ₂ o alkyl, preferably C ₂ -C ₂ o alkyl, more preferably ethyl, butyl or ethylhexyl, n is equal to 2 to 12, preferably 2 to 8, more preferably 2 to 5 and most preferably 2 or 3 is and

R ¹ is hydrogen or CH ₃ -.

It should be noted at this point that the scope of the invention includes all possible and possible combinations of the above-mentioned and listed below, general or preferred ranges mentioned components, ranges of values, definitions of residues or process parameters.

The term "copolymer" includes polymers having more than one monomer unit.

For example, in one embodiment of the invention, the copolymer is exclusively derived from the three monomer types (a), (b) and (d) and is therefore a terpolymer. Thus, all α, β-ethylenically unsaturated carboxylic acid ester units (c) of the hydrogenated nitrile-diene carboxylic acid ester copolymer are PEG-acrylate units (d) of the general formula (I).

Also included in the term copolymer are, for example, quaternary polymers derived from the three monomer types (a), (b) and (d) and a further α, β-ethylenically unsaturated carboxylic acid ester unit (c) which is different from the PEG-acrylate unit (d). different.

The term "nitrile-diene-carboxylic acid ester copolymer" in the context of this invention is a copolymer comprising at least one α, β-ethylenically unsaturated nitrile unit, at least one conjugated diene unit and at least one α, β- ethylenically unsaturated carboxylic ester unit. The term thus also encompasses copolymers having two or more α, β-ethylenically unsaturated nitrile monomer units, two or more conjugated diene monomer units and two or more α, β-ethylenically unsaturated carboxylic acid ester units. The term "hydrogenated" describes that the degree of hydrogenation of the butadiene units in the hydrogenated nitrile-diene carboxylic acid ester copolymer is from 50% to 100%, preferably from 90% to 100%, more preferably from 95% to 100%, and most preferably to 99% to 100% α, β-ethylenically unsaturated nitrile As the α, β-ethylenically unsaturated nitrile forming the α, β-ethylenically unsaturated nitrile units (a), any known α, β-ethylenically unsaturated nitrile can be used. Preference is given to (C ₃ -C ₅ ) a, B-ethylenically unsaturated nitriles such as acrylonitrile, a-haloacrylonitrile such as, for example, α-chloroacrylonitrile and α-bromoacrylonitrile, o alkylacrylonitrile such as, for example, methacrylonitrile, ethacrylonitrile or mixtures of two or more α, β- ethylenically unsaturated nitriles, particular preference being given to acrylonitrile, methacrylonitrile, ethacrylonitrile or mixtures thereof Acrylonitrile is very particularly preferred.

The amount of α, β-ethylenically unsaturated nitrile units (a) is typically in the range of 0.1 to 20 wt .-%, preferably 1 to 19 wt .-%, particularly preferably from 8 to 18 wt .-% based on the Total amount of 100% by weight of all monomer units of the hydrogenated nitrile-diene carboxylic ester copolymer.

Conjugated diene

The conjugated diene which constitutes the conjugated diene units (b) may be of any nature, in particular conjugated C ₄ -C ₂ dienes. Particular preference is given to 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, 1,3-pentadiene (piperylene) or mixtures thereof. Particular preference is given to 1,3-butadiene and isoprene or mixtures thereof. Very particular preference is 1, 3-butadiene.

The amount of conjugated diene is typically in the range of 15 to 74.9% by weight, preferably 21 to 73% by weight, and more preferably 27 to 65% by weight, based on the total amount of 100% by weight of all Monomer units of the hydrogenated nitrile-diene-carboxylic acid ester copolymer. α, β-ethylenically unsaturated carboxylic acid esters

In addition to the α, β-ethylenically unsaturated nitrile units and the conjugated diene units, the hydrogenated nitrile-diene carboxylic ester copolymer contains as a third unit at least one α, β-ethylenically unsaturated carboxylic acid ester unit (c), wherein at least 15% by weight, preferably at least 20% by weight of the α, β-ethylenically unsaturated carboxylic acid ester unit (c) based on the total amount of all monomer units of 100% by weight of a PEG acrylate (d) of the general formula

(I)

Formula (I)

are derived, where

R ¹ is hydrogen or CH ₃ -.

In the context of this invention, the term "(meth) acrylate" stands for "acrylate" and "methacrylate." If the radical R ^{1 of} the general formula (I) is CH ₃ -, this is a methacrylate.

The term "polyethylene glycol" or the abbreviation "PEG" in the context of this invention stands for ethylene glycol sections having two ethylene glycol repeating units (PEG-2, n equals 2) to 12 ethylene glycol repeating units (PEG-2 to PEG-12; equal to 2 to 12).

The term "PEG acrylate" is also abbreviated to PEG-X- (M) A, where "X" represents the number of repeating ethylene glycol units, "MA" represents methacrylate and "A" represents acrylate. Acrylate units derived from PEG acrylates of general formula (I) are referred to in the context of this invention as "PEG acrylate unit" (d).

Preferred PEG acrylate units (d) are derived from the PEG acrylates of the following formulas Nos. 1 to 8, where n is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 , preferably 2, 3, 4, 5, 6, 7 or 8, more preferably 2, 3, 4 or 5 and most preferably 2 or 3 is:

Ethoxypolyethylenglycolacrylat

(Formula No. 1)

Ethoxypolyethylenglycolmethacrylat

(Formula No. 2)

Propoxypolyethylenglycolacrylat

(Formula No. 3)

Propoxypolyethylenglycolmethacrylat

(Formula No. 4)

Butoxypolyethylenglycolacrylat

(Formula No. 5)

Butoxypolyethylenglycolmeth

acrylate

(Formula No. 6)

Ethylhexyloxypolyethylenglycolacrylat

(Formula No. 7)

Ethylhexyloxypolyethylene glycol methacrylate

(Formula No. 8)

Other common names for ethoxypolyethylene glycol acrylate (Formula No. 1) include poly (ethylene glycol) ethyl ether acrylate, ethoxy PEG acrylate, Ethoxypoly (ethylene glycol) monoacrylate or poly (ethylene glycol) monoethyl ether monoacrylate.

This PEG-acrylates may be obtained commercially, for example from Arkema under the trade name Sartomer ^®, Evonik under the trade name Visiomer ^® or from Sigma Aldrich.

The amount of PEG acrylate units (d) in copolymers according to the invention is in the range from 15 to 65% by weight, preferably from 20 to 60% by weight and more preferably from 20 to 55% by weight, based on the total amount of 100% by weight .-% of all monomer units. In an alternative embodiment, the amount of PEG acrylate units (d) is from 20 to 60% by weight and the amount of α, β-ethylenically unsaturated carboxylic acid ester units (c) other than the PEG acrylate units (d) is from 0 to 40 wt .-%, based on the total amount of 100 wt .-% of all monomer units, wherein the total amount of carboxylic acid ester units does not exceed 60 wt .-%.

The PEG acrylate units (d) thus form, in whole or in part, the α, β-ethylenically unsaturated carboxylic acid ester units (c).

Typical α, β-ethylenically unsaturated Carbonsaureestereinheiten (c) which are different from the PEG-acrylate (d) · alkyl, in particular C ₄ -C ₈ alkyl, preferably n-butyl, tert-butyl, n-pentyl or n-hexyl (meth) acrylate;

• alkoxyalkyl, especially C ₄ -C ₈ alkoxyalkyl, preferably C ₄ -C ₂ - alkoxyalkyl (meth) acrylate;

• hydroxyalkyl, in particular C ₄ -C ₈ hydroxyalkyl, preferably C ₄ -C ₂ - hydroxyalkyl (meth) acrylate;

• cycloalkyl, especially C ₅ -C ₈ cycloalkyl, preferably C ₆ -C ₂ cycloalkyl, more preferably cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate; • alkylcycloalkyl, in particular C ₆ -C ₂ -Alkylcycloalkyl-, preferably C7-C1 ₀ - alkylcycloalkyl, particularly preferably methylcyclopentyl (meth) acrylate and ethylcyclohexyl (meth) acrylate;

Aryl, in particular C ₆ -C ₄ -aryl-monoester, preferably phenyl (meth) acrylate or benzyl (meth) acrylate;

Amino-containing α, β-ethylenically unsaturated carboxylic acid esters, for example dimethylaminomethyl acrylate or diethylaminoethyl acrylate;

Α, β-ethylenically unsaturated dicarboxylic acid monoalkyl esters, preferably o alkyl, in particular C ₄ -C ₈ -alkyl, preferably n-butyl, tert-butyl, n-pentyl or n-hexyl, particularly preferably mono- n-butyl maleate, mono-n-butyl fumarate, mono-n-butylcitraconate, mono-n-butyl itaconate, very particularly preferably mono-n-butyl maleate, o alkoxyalkyl, in particular C ₄ -C ₈ -alkoxyalkyl, preferably C ₄ -C - | ₂ - alkoxyalkyl, o hydroxyalkyl, in particular C ₄ -C ₈ -hydroxyalkyl, preferably C ₄ -C ₂ -hydroxyalkyl, cycloalkyl-, in particular C ₅ -C ₈ -cycloalkyl, preferably C ₆ -C ₂ - Cycloalkyl, more preferably monocyclopentyl maleate, monocyclohexyl maleate,

Monocycloheptyl maleate, monocyclopentyl fumarate, monocyclohexyl fumarate, monocycloheptyl fumarate, monocyclopentylcitraconate, monocyclohexylcitraconate, monocycloheptylcitraconate, monocyclopentyl itaconate,

Monocyclohexylitaconat and Monocycloheptylitaconat, o alkylcycloalkyl, in particular C ₆ -C ₂ -Alkylcycloalkyl-, preferably C7-C1 ₀ - alkylcycloalkyl, particularly preferably Monomethylcyclopentylmaleat and

Monoethylcyclohexyl maleate, monomethylcyclopentyl fumarate and monoethylcyclohexyl fumarate, monomethylcyclopentylcitraconate and

Monoethylcyclohexylcitraconat; Monomethylcyclopentyl itaconate and monoethylcyclohexyl itaconate; Aryl, in particular C ₆ -C ₄ -aryl monoesters, are preferred

Maleic monoarylester, fumaric monoarylester, Citraconic monoaryl ester or itaconic monoaryl ester, more preferably monophenyl maleate or monobenzyl maleate, monophenyl fumarate or monobenzyl fumarate, monophenyl citrate or monobenzyl citraconate, monophenyl itaconate or monobenzyl itaconate, unsaturated polycarboxylic acid polyalkyl esters such as

Dimethyl maleate, dimethyl fumarate, dimethyl itaconate or diethyl itaconate; or mixtures thereof.

In an alternative embodiment, the hydrogenated nitrile-diene carboxylic acid ester copolymer of the invention contains, in addition to the α, β-ethylenically unsaturated nitrile moiety (a), the conjugated diene moiety (b) and the PEG acrylate moiety (d) derived from a PEG acrylate of the general Formula (I) as the unsaturated carboxylic acid ester unit (c) A dicarboxylic acid monoalkylester unit, preferably monobutyl maleate.

In a preferred hydrogenated nitrile-diene carboxylic acid ester copolymer according to the invention, the α, β-ethylenically unsaturated nitrile unit (a) is derived from acrylonitrile or methacrylonitrile, more preferably from acrylonitrile, the conjugated diene unit (b) isoprene or 1,3-butadiene, more preferably from 1,3-butadiene, and the α, β-ethylenically unsaturated carboxylic ester unit (c) exclusively a PEG acrylate unit (d) derived from PEG acrylate of the general formula (I) wherein n is 2 to 8, especially preferably of PEG acrylate of the general formula (I) with n equal to 2 or 3, where no further carboxylic ester unit (c) is present.

In another preferred hydrogenated nitrile-diene carboxylic acid ester copolymer of the invention, the α, β-ethylenically unsaturated nitrile moiety (a) is derived from acrylonitrile or methacrylonitrile, more preferably from acrylonitrile, the conjugated diene moiety (b) isoprene or 1,3-butadiene , more preferably from 1,3-butadiene, and the α, β-ethylenically unsaturated carboxylic acid ester moiety (c) derived from a first PEG acrylate of general formula (I) wherein n is 2 to 12, more preferably PEG acrylate of the general formula (I) with n equal to 2 or 3 and an α, β-ethylenically unsaturated carboxylic acid ester unit (c) which is different from the PEG-acrylate units (d). In addition, the hydrogenated nitrile-diene carboxylic acid ester copolymer may contain one or more other copolymerizable monomers (e) in an amount of from 0% to 20% by weight, preferably from 0.1% to 10% by weight. based on the total amount of 100 wt. % of all monomer units included. The amounts of the remaining monomer units (a), (b), (c) and (d) are then suitably reduced so that the sum of all monomer units always gives 100 wt .-%. The hydrogenated nitrile-diene carboxylic acid ester copolymer may contain as further copolymerizable monomers (e) one or more aromatic vinyl monomers, preferably styrene, α-methylstyrene and vinylpyridine, fluorine-containing vinyl monomers, preferably fluoroethyl vinyl ether,

Fluoropropyl vinyl ether, o-fluoromethylstyrene, Vinylpentafluorbenzoat, difluoroethylene and tetrafluoroethylene, or α-olefins, preferably C ₂ -Ci ₂ -olefins such as ethylene, 1-butene, 4-butene, 4-methyl-1-pentene, 1 -hexene or 1-octen, non-conjugated dienes, preferably C ₄ -C ₂ -dienes such as 1, 4-pentadiene, 1, 4-hexadiene, 4-cyanocyclohexene, 4-vinylcyclohexene, vinylnorbones, dicyclopentadiene or else

Alkynes such as 1- or 2-butyne, α, β-ethylenically unsaturated monocarboxylic acids, preferably acrylic acid, methacrylic acid, crotonic acid or cinnamic acid, α, β-ethylenically unsaturated dicarboxylic acids, preferably maleic acid, fumaric acid, citraconic acid, itaconic acid, copolymerizable antioxidants, for example N- ( 4-anilinophenyl) acrylamide, N- (4-anilinophenyl) methacrylamide, N- (4-anilinophenyl) cinnamamide, N- (4-anilinophenyl) crotonamide, N-phenyl-4- (3-vinylbenzyloxy) aniline, N-phenyl- 4- (4-vinylbenzyloxy) aniline or crosslinkable monomers, for example, divinyl components such as divinylbenzene; contain.

In an alternative embodiment, the hydrogenated nitrile-diene carboxylic ester copolymer contains as PEG acrylate units (c) ethoxy, butoxy or ethylhexyloxy polyethylene glycol (meth) acrylate having 2 to 12 ethylene glycol repeating units, more preferably ethoxy or butoxy Polyethylene glycol (meth) acrylate having 2 to 5 ethylene glycol repeat units, and most preferably ethoxy or butoxy polyethylene glycol (meth) acrylate having 2 or 3 ethylene glycol repeating units.

In another alternative embodiment of the hydrogenated nitrile-diene carboxylic acid ester copolymer, n is 2 or 3, R is ethyl or butyl and R ¹ is hydrogen or methyl, preferably n is 2, R is butyl and R ¹ is methyl.

In a further alternative embodiment, the hydrogenated nitrile-diene carboxylic acid ester copolymer comprises 8 to 18% by weight of acrylonitrile units, 27 to 65% by weight of 1, 3-butadiene units and 27 to 55% by weight of PEG-2 acrylate units or PEG-3 acrylate units.

Most preferably, the hydrogenated nitrile-diene carboxylic ester copolymer contains

From 13 to 17% by weight of α, β-ethylenically unsaturated nitrile unit (a), preferably acrylonitrile, from 36 to 44% by weight of the conjugated diene unit (b), preferably 1,3-butadiene, and

43 to 47 wt .-% PEG acrylate unit (d), derived from a PEG acrylate of the general formula (I), preferably Butoxydiethylenglycolmethacrylat.

The hydrogenated nitrile-diene carboxylic ester copolymer of the present invention typically has a number average molecular weight (Mn) of 10,000 g / mol to 2,000,000 g / mol, preferably 50,000 g / mol to 1,000,000 g / mol, more preferably 100,000 g / mol to 500,000 g / mol and most preferably 150,000 g / mol to 300,000 g / mol.

The hydrogenated nitrile-diene carboxylic acid ester copolymer of the present invention typically has a polydispersity index (PDI = M _w / M _n , where M _{w is} the weight average molecular weight) of from 1.5 to 6, preferably from 2 to 5, and most preferably from 2.5 to 4 on.

The hydrogenated nitrile-diene carboxylic acid ester copolymer of the present invention typically has a Mooney viscosity (ML1 + 4 @ 100 ° C) of from 10 to 150, preferably from 20 to 120, and more preferably from 25 to 100. The terpolymers and quaternary polymers according to the invention which comprise PEG-2-MA repeat units are characterized in that they have a very particularly low content of gel.

The hydrogenated nitrile-diene carboxylic acid ester copolymer according to the invention is characterized in that it has a glass transition temperature Tg, measured according to DIN 53765, of -40 ° C or less.

The hydrogenated nitrile-diene carboxylic acid ester copolymer according to the invention is characterized in that it enables the preparation of vulcanizates in which

The glass transition temperature Tg, measured according to DIN 53765, has a value of less than -40 ° C, preferably a value of -44 ° C or less and particularly preferably a value of -47 ° C or less, and

The swelling in IRM 903, measured according to DIN ISO 1817 for 7 days at 150 ° C., has a value of 51% or less, preferably a value of 45% or less and particularly preferably a value of 43% or less.

Process for the preparation of unhydrogenated nitrile-diene-carboxylic acid ester copolymers

The invention further provides a process for the preparation of unhydrogenated nitrile-diene carboxylic ester copolymers, which comprises subjecting at least one α, β-ethylenically unsaturated nitrile, at least one conjugated diene and at least one α, β-ethylenically unsaturated carboxylic acid monoester to emulsion polymerization become.

The preferred subject matter of the invention is a process for the preparation of unhydrogenated nitrile-diene-carboxylic acid ester copolymers, which comprises 0.1 to 20% by weight, preferably 1 to 19% by weight and more preferably 8 to 18% by weight. % of at least one α, β-ethylenically unsaturated nitrile, 15 to 74.9% by weight, preferably 21 to 73% by weight and particularly preferably 27 to 65% by weight of at least one conjugated diene and 25 to 65% by weight. %, preferably 26 to 60 wt .-% and particularly preferably 27 to 55 wt .-% of at least one α, β-ethylenically unsaturated carboxylic acid ester, wherein at least 15 wt .-%, preferably at least 20 wt .-% of the α, β-ethylenically unsaturated carboxylic acid ester, based on the total amount of all monomers of 100% by weight, of PEG-acrylate of the general formula (I)

Formula (I) are where

R is branched or unbranched -C ₂ o alkyl, preferably C ₂ -C ₂ o alkyl, more preferably ethyl, butyl or ethylhexyl, n is equal to 2 to 12, preferably 2 to 8, more preferably 2 to 5 and most preferably 2 or 3 and

R ¹ is hydrogen or CH ₃ - is subjected to an emulsion polymerization.

The preparation of the hydrogenation required as an intermediate unhydrogenated nitrile-diene carboxylic acid ester copolymers can be carried out by polymerization of the aforementioned monomers and is in the literature (eg Houben-Weyl, Methods of Organic Chemistry Bd.1 / 1, 30 Georg Thieme Verlag Stuttgart 1961 ) and is not particularly limited. In general, it is a process in which α, β-ethylenically unsaturated nitrile units, conjugated diene units, and PEG-acrylate units are copolymerized as desired. As the polymerization method, any known emulsion polymerization method, suspension polymerization method, bulk polymerization method and solution polymerization method can be used. Preference is given to the emulsion polymerization process. Emulsion polymerization is understood in particular to be a process known per se, in which water is usually used as the reaction medium (see, inter alia, Römpp Lexikon der Chemie, Volume 2, 10th Edition 1997; PA Lovell, MS El-Aasser, Emulsion Polymerization and Emulsion Polymers, John Wiley & Sons, ISBN: 0471 96746 7; H. Gerrens, Forthr. Hochpolym. Forsch. 1, 234 (1959)). The incorporation rate of the termonomer can be readily adjusted by the skilled person so that a terpolymer according to the invention is obtained. The Monomers can be submitted or implemented by incrementing in several steps.

The invention thus also relates to the unhydrogenated nitrile-diene carboxylic acid ester copolymers necessary for the preparation of the hydrogenated nitrile-diene carboxylic acid ester copolymers according to the invention, comprising

(C) 25 to 65 wt .-%, preferably 26 to 60 wt .-% and particularly preferably 27 to 55 wt .-% of at least one α, β-ethylenically unsaturated carboxylic ester unit, wherein at least 15 wt .-%, preferably at least 20 % By weight of the α, β-ethylenically unsaturated carboxylic acid ester units (c), based on the total amount of all monomer units of 100% by weight, of a PEG acrylate (d) of the general formula (I)

Formula (I) are derived, wherein

R is branched or unbranched Ci-C ₂ o alkyl, preferably C ₂ -C ₂ o alkyl, more preferably ethyl, butyl or ethylhexyl, n is equal to 2 to 12, preferably 2 to 8, more preferably 2 to 5 and most preferably 2 or 3 and is equal to hydrogen or CH ₃ -, and their use for the preparation of hydrogenated nitrile-diene carboxylic acid ester copolymers.

Metathesis and / or hydrogenation

It is also possible that the preparation of the unhydrogenated nitrile-diene carboxylic acid ester copolymer is followed by a metathesis reaction to reduce the molecular weight of the nitrile-diene carboxylic ester copolymer or a metathesis reaction and subsequent hydrogenation or only hydrogenation. These metathesis or hydrogenation reactions are well known in the art and described in the literature. The metathesis is known, for example, from WO-A-02/100941 and WO-A-02/100905 and can be used for molecular weight reduction.

Process for the preparation of hydrogenated nitrile-diene-carboxylic acid ester copolymers

The invention also provides a process for preparing hydrogenated nitrile-diene carboxylic acid ester copolymers, which comprises at least one α, β-ethylenically unsaturated nitrile, at least one conjugated diene and at least one PEG acrylate of the general formula (I) of an emulsion polymerization be subjected and then hydrogenated.

Following the copolymerization of the unhydrogenated nitrile-diene-carboxylic acid ester copolymers, these are, at least partially, hydrogenated (hydrogen addition reaction). In the at least partially hydrogenated nitrile-diene copolymers, at least part of the C = C double bonds of the recurring unit derived from the conjugated diene are specifically hydrogenated. The degree of hydrogenation of the conjugated diene units (b) in hydrogenated nitrile-diene carboxylic acid ester copolymers of the invention is from 50% to 100%, preferably from 90% to 100% and particularly preferably from 99% to 100%.

In the context of this invention, the term "hydrogenated nitrile-diene-carboxylic acid ester copolymer" is thus a copolymer comprising at least one α, β-ethylenically unsaturated nitrile monomer unit, at least one conjugated diene monomer unit and at least one α, β-ethylenically unsaturated carboxylic ester unit, wherein the conjugated diene units are hydrogenated to 50% to 100%, preferably 90% to 100% and most preferably 99% to 100%. The hydrogenation of nitrile-diene copolymers is known, for example, from US Pat. No. 3,700,637, DE-A-2,539,132, DE-A-3,046,008, DE-A-3,046,251, DE-A-3 227 650, DE-A-3 329 974, EP-A-1 1 412, FR-B 2 540 503. Hydrogenated nitrile-diene copolymers are distinguished by high tear resistance, low abrasion, low compression set after compression and tension and good oil resistance, but above all by remarkable stability against thermal and oxidative influences.

Vulcanisable mixtures containing hydrogenated nitrile-diene carboxylic acid ester copolymers

The present invention further provides vulcanizable mixtures comprising hydrogenated nitrile-diene-carboxylic acid ester copolymers and at least one crosslinker. In a preferred embodiment, it is vulcanizable mixtures which additionally contain at least one filler.

Suitable crosslinkers are, for example, peroxidic crosslinkers, such as bis (2,4-dichlorobenzyl) peroxide, dibenzoyl peroxide, bis (4-chlorobenzoyl) peroxide, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, ie /f.butyl perbenzoate, 2,2-bis (t-butylperoxy) butene, 4,4-di-he / f-butyl peroxynonyl valerate, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, ie / f-butylcumyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene, di-t-butyl peroxide and 2,5-dimethyl-2,5-di (t-butylperoxy) -hex-3-yn. It may be advantageous, in addition to these peroxidic crosslinkers, to use further additives with the aid of which the crosslinking yield can be increased. Examples include triallyl isocyanurate, triallyl cyanurate, trimethylolpropane tri (meth) acrylate, triallyl trimellitate, ethylene glycol dimethacrylate, butanediol dimethacrylate, zinc diacrylate, zinc dimethacrylate, 1,2 -polybutadiene or N, N ^{'-m-phenylene} bismaleimide suitable. The total amount of the peroxidic crosslinker (s) is usually in the range of 1 to 20 phr, preferably in the range of 1.5 to 15 phr, and more preferably in the range of 2 to 10 phr, based on the hydrogenated nitrile-diene carboxylic acid ester copolymer.

As crosslinkers it is also possible to use sulfur in elementary soluble or insoluble form or sulfur donors.

Sulfur donors include, for example, dimorpholyl disulfide (DTDM), 2-morpholino-dithiobenzothiazole (MBSS), caprolactam disulfide, Dipentamethylene thiuram tetrasulfide (DPTT) and tetramethyl thiuram disulfide (TMTD).

Even in the case of sulfur vulcanization of the hydrogenated nitrile-diene-carboxylic acid ester copolymer according to the invention, it is possible to use further additives with the aid of which the crosslinking yield can be increased. In principle, however, the crosslinking can also take place with sulfur or sulfur donors alone.

Conversely, the crosslinking of the hydrogenated nitrile-diene carboxylic acid ester copolymers according to the invention can also be carried out only in the presence of the abovementioned additives, i. without the addition of elemental sulfur or sulfur donors. As additives with the aid of which the crosslinking yield can be increased, e.g. Dithiocarbamates, thiurams, thiazoles, sulfenamides, xanthogenates, guanidine derivatives, caprolactams and thiourea derivatives.

As dithiocarbamates can be used, for example: Ammoniumdimethyl- dithiocarbamate, sodium diethyldithiocarbamate (SDEC), sodium dibutyldithiocarbamate (SDBC), zinc dimethyldithiocarbamate (ZDMC), zinc diethyldithiocarbamate (ZDEC), Zinkdibutyldithio-carbamate (ZDBC), zinc ethylphenyldithiocarbamate (ZEPC), zinc dibenzyldithiocarbamate (ZBEC), zinc pentamethylenedithiocarbamate ( Z5MC), tellurium diethyldithiocarbamate, nickel dibutyldithio-carbamate, nickel dimethyldithiocarbamate and zinc diisononyl dithiocarbamate. As thiurams, there may be used, for example, tetramethylthiuram disulfide (TMTD), tetramethylthiuram monosulfide (TMTM), dimethyldiphenylthiuram disulfide, tetrabenzylthiuram disulfide, dipentamethylenethiuram tetrasulfide and tetraethylthiuram disulfide (TETD). As thiazoles, there may be used, for example, 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), zinc mercaptobenzothiazole (ZMBT) and copper 2-mercaptobenzothiazole. Examples of sulfenamide derivatives which can be used are: N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), N-he-1-butyl-2-benzthiazyl sulfenamide (TBBS), N, N'-dicyclohexyl-2-benzthiazyl sulfenamide (DCBS), 2- Morpholinothiobenzothiazole (MBS), N-oxydiethylene-thiocarbamyl-N-he / f.butyl sulfenamide and

Oxydiethylenethiocarbamyl-N-oxyethylensulfenamid. As xanthates, there may be used, for example, sodium dibutylxanthogenate, zinc isopropyldibutylxanthogenate and zinc dibutylxanthogenate. As guanidine derivatives can be used, for example: diphenylguanidine (DPG), di-o-tolylguanidine (DOTG) and o-tolylbiguanide (OTBG). As dithiophosphates can be used, for example: zinc dialkydithiophosphate (chain length of the alkyl radicals C ₂ to C _6), Kupferdialkyldithiophosphate (chain length of the alkyl radicals C ₂ to Ci ₆ ) and Dithiophoshorylpolysulfid. As caprolactam, for example, dithio-bis-caprolactam can be used. For example, Ν, Ν'-diphenylthiourea (DPTU), diethylthiourea (DETU) and ethylene thiourea (ETU) can be used as thiourea derivatives. Also suitable as additives are, for example: zinc diamine diisocyanate, hexamethylenetetramine, 1,3-bis (citraconimidomethyl) benzene and also cyclic disulfanes.

The additives mentioned as well as the crosslinking agents can be used both individually and in mixtures. The following substances are preferably used for crosslinking the hydrogenated nitrile-diene-carboxylic acid ester copolymers: sulfur, 2-mercaptobenzothiazole, tetramethylthiuram disulfide,

Tetramethylthiuram monosulfide, zinc dibenzyl dithiocarbamate, dipentamethylene thiuram tetrasulfide, zinc dialkydithiophosphate, dimorpholyl disulfide, tellurium diethyl dithiocarbamate, nickel dibutyl dithiocarbamate, zinc dibutyl dithiocarbamate, zinc dimethyl dithiocarbamate and dithiobis-caprolactam.

The crosslinking agents and the abovementioned additives may each be used in amounts of from 0.05 phr to 10 phr, preferably from 0.1 phr to 8 phr, in particular from 0.5 phr to 5 phr (individual dosing, in each case based on the active substance) based on the hydrogenated nitrile Diene carboxylic acid ester copolymer. In the sulfur crosslinking, it may also be useful to use in addition to the crosslinking agents and additives mentioned above, other inorganic or organic substances, for example: zinc oxide, zinc carbonate, lead oxide, magnesium oxide, calcium oxide, saturated or unsaturated organic fatty acids and their zinc salts, polyalcohols , Amino alcohols such as triethanolamine and amines such as dibutylamine, dicyclohexylamine, cyclohexylethylamine, polyamines and polyetheramines.

Other optional components:

Optionally, such vulcanizable mixtures may also contain one or more additives and fibers which are familiar to the person skilled in the rubber art. These include anti-aging agents, anti-reversion agents, light stabilizers, antiozonants, processing aids, mold release agents, plasticizers, mineral oils, tackifiers, blowing agents, dyes, pigments, waxes, resins, extenders, fillers, such as barium sulfate, titanium dioxide, zinc oxide, calcium oxide, calcium carbonate, Magnesium oxide, aluminum oxide, iron oxide, aluminum hydroxide, magnesium hydroxide, aluminum silicates, diatomaceous earth, talc, kaolins, bentonites, carbon nanotubes, graphene, teflon (the latter preferably in powder form), or silicates, carbon blacks, silicic acids, fumed silica, silica, silanized silica, natural products such as alumina, kaolins, wollastonite, organic acids, anti-caking agents, metal oxides, reinforcements (fibers) of glass, cords, fabrics, fibers of aliphatic and aromatic polyamides (Nylon®, Aramid®), polyesters and natural fiber products, salts of unsaturated carboxylic acids such as zinc diacrylate (ZDA), zinc methacrylates (ZMA) and zinc dimethyl acrylate (ZDMA), liquid acrylates, or other additives known in the rubber industry (Ullmann's Encyclopedia of Industrial Chemistry, VCH Verlagsgesellschaft mbH, D-69451 Weinheim, 1993, vol A 23 "Chemicals and Additives", pp. 366-417).

Suitable filler activators are, in particular, organic silanes, for example vinyltrimethyloxysilane, vinyldimethoxymethylsilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N-cyclohexyl-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, isooctyltrimethoxysilane,

Isooctyltriethoxysilane, hexadecyltrimethoxysilane or (octadecyl) methyldimethoxysilane into consideration. Further filler activators are, for example, surfactants such as triethanolamine and ethylene glycols having molecular weights of 74 to 10,000 g / mol. The amount of filler activators is usually 0 to 10 parts by weight based on 100 parts by weight of the nitrile rubber.

The total amount of additives and fibers is typically in the range of 1 to 300 parts by weight, based on 100 parts by weight of the nitrile rubber. A process for preparing a vulcanizable mixture containing hydrogenated nitrile-diene carboxylic acid ester copolymers

The invention further provides a process for preparing vulcanizable mixtures containing hydrogenated nitrile-diene carboxylic acid ester copolymers by mixing the hydrogenated nitrile-diene carboxylic acid ester copolymer with at least one crosslinker and optionally further components contained. This mixing process can be carried out in all mixing units customary in the rubber industry, such as, for example, internal mixers, Banbury mixers or rolls. The order of addition can be determined without difficulty for the person skilled in the art by suitable experiments. By way of example, two variants are shown below, as it is possible to proceed: Process A: Production in an internal mixer

Preferred are internal mixers with interlocking rotor geometry.

At the start time, the feed of the internal mixer with the bale form hydrogenated nitrile-diene carboxylic acid ester copolymer takes place and it comes to the crushing of the bales. After a suitable mixing period, the fillers and additives are added. The mixing is carried out under the control of the temperature with the proviso that the mix remains for a suitable time at a temperature in the range of 80 ° C to 150 ° C. After a further suitable mixing period, the addition of the further mixture constituents, such as optionally stearic acid, antioxidants, plasticizers, white pigments (for example titanium dioxide), dyes and other processing agents, takes place. After another suitable mixing period, the internal mixer is vented and the shaft cleaned. After a further suitable period of time, the internal mixer is emptied to obtain the vulcanizable mixture. Suitable periods are a few seconds to a few minutes to understand. The crosslinking chemicals can either be mixed in a separate step on the roll, especially when mixed at elevated mixing temperature or be added directly in the internal mixer with. Care must be taken here that the mixing temperature is below the reaction temperature of the crosslinking chemicals.

The vulcanizable mixtures so prepared may be evaluated in a conventional manner, such as Mooney viscosity, Mooney scorch or a rheometer test.

Method B: Production on the roll When rolls are used as mixing aggregates, first the hydrogenated nitrile-diene-carboxylic acid copolymer is added to the roll. After a homogeneous roll of skin has formed, the fillers, plasticizers, and other additives besides the crosslinking chemicals are added. After mixing in all the components, the crosslinking chemicals are added and mixed. Then the mixture is cut three times on the right and three times on the left and toppled 5 times. The finished rolled skin is rolled to the desired thickness and further processed according to the desired test methods. Process for the preparation of vulcanizates containing hydrogenated nitrile-diene carboxylic acid ester copolymers

The invention further provides the process for the preparation of vulcanizates, preferably as moldings, containing hydrogenated nitrile-diene-carboxylic acid ester copolymers (vulcanization), which comprises subjecting the vulcanizable mixture comprising hydrogenated nitrile-diene-carboxylic acid ester copolymers to vulcanization, preferably in a molding process and further preferably at temperatures in the range of 100 ° C to 250 ° C, more preferably at temperatures in the range of 120 ° C to 250 ° C and most preferably temperatures in the range of 130 ° C to 250 ° C. The vulcanizable mixtures are further processed for this purpose with calenders, rollers or extruders. The preformed mass is then vulcanized in presses, autoclaves, hot air systems or in so-called automatic mat vulcanization plants ("Auma"), preferably temperatures in the range of 100 ° C to 250 ° C, more preferably temperatures in the range of 120 ° C to 250 ° C and most preferably temperatures in the range of 130 ° C. to 250 ° C. The vulcanization time is typically 1 minute to 24 hours and preferably 2 minutes to 1 hour Depending on the shape and size of the vulcanizates, a second vulcanization by The invention further relates to the vulcanizates obtainable based on hydrogenated nitrile-diene-carboxylic acid ester copolymers according to the invention.

The invention also provides the use of the vulcanizates based on hydrogenated nitrile-diene-carboxylic acid ester copolymers according to the invention for the production of molded parts selected from the group consisting of belts, seals, rollers, shoe components, hoses, damping elements, stators and cable sheaths, preferably belts and seals.

The invention thus vulcanized as molded parts based on inventive hydrogenated nitrile-diene carboxylic ester copolymers, which are preferably selected from belts, gaskets, rollers, shoe components, hoses, damping elements, stators and cable sheathing, more preferably belts and seals. The methods which can be used for this purpose, such as molding, injection molding or extrusion processes, for example, as well as the corresponding injection molding apparatuses or extruders, are well known to the person skilled in the art. In the preparation of these moldings, the hydrogenated nitrile-diene carboxylic acid ester Copolymers nor the usual, known in the art and be suitably selected from him with the usual expertise tools such as fillers, Füllstoffaktivatoren, accelerators, crosslinkers, antiozonants, antioxidants, processing oils, extender oils, plasticizers, activators or scorchers be added.

The advantage of the invention lies in particular in the fact that the hydrogenated nitrile-diene-carboxylic acid ester copolymers according to the invention are suitable for the preparation of vulcanizates which have a Tg of less than -40 ° C. and a swelling of 51% or less and thus of the vulcanizates based on the known HNBR copolymers are superior.

Examples:

Measurement method:

The RDB content (residual double bond content) in% is determined by the following FT-IR measurement: The IR spectra of the hydrogenated nitrile-diene carboxylic acid ester copolymer before, during and after the hydrogenation are carried out by means of an IR device with the designation Thermo Nicolet FT-IR Spectrometer Type AVATAR 360. For this purpose, a monochlorobenzene solution of the hydrogenated nitrile-diene carboxylic acid ester copolymer is applied to a NaCI plate, dried to a film and measured. The degree of hydrogenation is determined by FT-IR analysis according to the ASTM D 567095 method.

The values for the Mooney viscosity (ML1 + 4 @ 100 ° C.) are determined in each case by means of a shear disk viscometer in accordance with ASTM D1646-07.

The determination of the molecular weight is carried out by

Gel permeation chromatography (GPC). A modular system with Shodex RI-71 differential refractometer, Autosampler S 5200 (SFD), column oven (ERC-125), pump Shimadzu LC 10 AT) and a column combination of 3 PLgel 10 μηη mixed B 300x7.5 mm from Agilent was used. The solvent used was tetrahydrofuran, the molecular weights contained are based on polystyrene standards from PSS (Mainz). The finished THF sample solutions are filtered through syringe filters with 0.45 μηη PTFE membranes and 25 mm diameter. The measurements were carried out at 40 ° C and a flow rate of 1 ml / min in tetrahydrofuran.

The determination of the molecular parameters such as number average molecular weight M _n , weight average molecular weight M _w and the resulting polydispersity index PDI is carried out from the Rl signal using the software "Empower 2 data base" from Waters.

The nitrogen content for the determination of the ACN content is determined in the nitrile group-containing copolymer rubbers according to Vario EL cube. Combustion in the CHN machine at approx. 1 150 ° C in the presence of oxidation catalysts and oxygen, aliquoting of the combustion gases, absorption of the interfering components and detection of N ₂ by thermal conductivity measuring cell (WLD). The determination of the microstructure and the termonomer content of the individual polymers was carried out by means of ¹ H-NMR (instrument: Bruker DPX400 with software TopSpin 1 .3, measuring frequency 400 MHz, solvent 1, 1, 2,2-tetrachloroethane-d2).

The glass transition temperature was obtained by means of a DSC measurement according to ASTM E 1356-03 or according to DIN 53765. For this purpose, between 10 mg and 15 mg of the sample were weighed into an aluminum pan and sealed. The pan was heated twice from -150 ° C to 150 ° C in a TA Instruments DS Instruments at a heating rate of 10 K / min. The glass transition temperature was determined from the second heating curve according to the standard mean value method. Swelling: Dumbbell specimens as used for tensile testing were stored at 150 ° C for 168 hours in I RM903 according to DI N ISO 1817 to determine swelling. Subsequently, the samples were measured and weighed and the volume swelling and mass increase determined. Subsequently, the tensile strength and elongation were determined according to ASTM D2240-81. The following substances were used in the examples:

The following chemicals were purchased as commercial products of the companies specified or come from production plants of the specified companies.

For the polymerization:

MEA methoxyethyl acrylate, molecular weight 130, 14 g / mol, Alfa

Aesar

BA butyl acrylate, molecular weight 128, 17 g / mol, sigma

Aldrich

PEG-2-MA butoxy diethylene glycol methacrylate (BDGMA),

Molecular weight 230.3 g / mol, Evonik Industries AG PEG-3-MA Ethoxytriethylene glycol methacrylate, molecular weight

246.3 g / mol, Evonik Industries AG

Disponil® SDS G sodium lauryl sulfate; BASF

Na salt of disproportionated resin acid CAS 61790-51 -0

Na ₂ C0 ₃ Merck KGaA t-DDM tertiary dodecylmercaptan; LANXESS Germany

GmbH

Glidox ^® 500 pinane; Renessenz

"Premix solution Fe (II) S0 _4" containing 0.986 g Fe (II) S0 ₄ ^* 7 H ₂ 0 and 2.0 g Rongalit C ^® in

400 g of water

Rongalite C sodium salt of a sulfinic acid derivative; Commercial product of BASF

Diethy I hyd roxy I at Merck KGaA

Vulkanox BKF ^® ^{2,2'-methylene-bis-} (4-methyl-6-IE / f.-butyl-phenol);

LANXESS Germany GmbH

Substances used in the vulcanizable composition:

Corax® N330 carbon black; Orion Engineered Carbons

Rhenofit® DDA 70% masterbatch based on octylated

diphenylamine; Rhein Chemie

Vulkanox ^(S, ZMB2 / C5 zinc salt of 4- and 5-methyl-2-mercaptobenzothiazole;

LANXESS Germany GmbH

Maglite Magnesium Oxide; CP Hall.

TAIC triallyl isocyanurate, 70% masterbatch; Chemie GmbH & Co

KG.

Perkadox ^® 14-40 Di (ie / f.-butylperoxyisopropyl) benzene 40% supported on

silica; Akzo Nobel Polymer Chemicals BV

I Preparation of the Unhydrogenated Nitrile-Diene Carboxylic Ester Copolymers (NBR 1 - 8)

The preparation of the NBR copolymers 1 to 8 used in the following examples was carried out according to the base formulation given in Table 1, all starting materials being stated in% by weight, based on 100% by weight of the monomer mixture. Table 1 also lists the respective polymerization conditions (temperature, conversion and time). Table 1: Preparation of the unhydrogenated nitrile-diene-carboxylic acid ester copolymers

(NBR 1-8; examples according to the invention are marked with an asterisk ^* ).

Table 2: Addition of the increments of the nitrile-diene carboxylic acid ester copolymers (NBR 1 - 8)

The increments of the monomers were added at the indicated monomer conversions ± 5%.

NBR 1 2 3 * 4 * 5 * 6 * 7 * 8 *

Conversion ACN (a) / BD (b) / termonomer (c) / BA (c)

[%] [% By weight]

21 3/7 / - / - - / - / - / - - / - / - / - 2/4 / - / - 2/5 / 2,8 / 1, 2 3/6 / - / - 3/5 / - / - 3/6 / - / -

33 - / - / - / - 3 / - / - I- 3 / - / 16 / - - / - / - / - 2/5 / 2,8 / 1, 2 - / - / - / - - / - / - / - - / - / - / -

42 3/7 / - / - - / - / - / - - / - / - / - 2/4 / - / - 2/5 / 2,8 / 1, 2 3/6 / - / - 3/4 / - / - 3/5 / - / - 63 3/6 / - / - - / - / - / - - / - / - / - 2/3 / - / - 2/3 / 2,8 / 1, 2 3/5 / - / - 3/4 / - / - 3/5 / - / -

The preparation of the nitrile-diene-carboxylic acid ester copolymers was carried out batchwise in a 20 L autoclave (NBR 1 and NBR 3) or 5 L autoclaves (NBR 2, N BR 4, N BR 5, N BR 6, NBR 7 and N BR 8) with stirrer. The autoclave batches were each 5.3 kg (NBR1) or 5.2 kg (NBR3) or 1.3 kg (NBR 2, N BR 4, N BR 6, NBR 7 and N BR 8) or 1.25 kg ( NBR 5) of the monomer mixture and a total amount of water of 9.2 kg (NBR 1) or 7.6 kg (NBR 3) or 2.5 kg (NBR 2, NBR 4) or 2.1 kg (NBR 6, NBR 7 and NBR 8) or 1.94 kg (NBR 5) and EDTA in an equimolar amount relative to the Fe-II. Of this amount of water were 7.2 kg (NBR 1) or 7.06 kg (NBR 3) or 2.25 kg (NBR 2, NBR 4) or 1, 85 kg (NBR 6 and NBR 7) or 1, 81 kg (NBR 8) or 1.75 kg (NBR 5) with the emulsifier in an autoclave and rinsed with a stream of nitrogen. Thereafter, the initial monomers and the amount of molecular weight regulator t-DDM indicated in Table 1 were added, and the reactor capped. After thermostatting of the contents of the reactor, the polymerizations were started by the addition of the premix solutions of pinane hydroperoxide (Glidox ^® 500).

The course of the polymerization was followed by gravimetric conversion determinations. When the yields given in Table 1 were reached, the polymerization was stopped by addition of an aqueous solution of diethylhydroxylamine. Unreacted monomers and other volatiles were removed by steam distillation.

Before coagulation of the respective NBR latex of this respectively with a 45% dispersion of Vulkanox BKF ^® (0% Vulkanox BKF ^®, 1 wt., Based on N BR-solid) was added. The mixture was then coagulated with CaCl ₂ , washed and the resulting crumb dried.

The dried NBR rubbers were characterized by Mooney viscosity, ACN content and glass transition temperature, and the content of the termonomers was determined by ¹ H-NMR analysis (Table 3). TABLE 3 Composition of the unhydrogenated nitrile-diene-carboxylic acid ester copolymers NBR 1 -8 (copolymerized monomer amounts in% by weight; examples according to the invention marked with an asterisk *)

II Preparation of Hydrogenated Nitrile-Diene-Carboxylic Ester Copolymers (HNBR 1 to 8)

Carrying out the hydrogenations

The following hydrogenations were carried out using the previously synthesized unhydrogenated nitrile-diene carboxylic ester copolymers (NBR 1 to 8).

Dry monochlorobenzene (MCB) was purchased from VWR, Wilkinson catalyst from Materia Inc. and triphenylphosphine from VWR and used as received. The results of the hydrogenation experiments are summarized in Table 4. Hydrogenations 1-8 were carried out in a 10 L high pressure reactor under the following conditions:

Solvent: monochlorobenzene

Solid Concentration: 12-13% by weight NBR terpolymer in MCB (518 g) Reactor temperature: 137-140 ° C

Reaction time: up to 4 hours

Catalyst & Charge: Wilkinson Catalyst: 0.337 g (0.065 phr);

Co-catalyst: triphenylphosphine: 5.18 g (1, 0 phr) hydrogen pressure (p H ₂ ): 8.4 MPa

Stirrer speed: 600 rpm

The NBR-containing polymer solution is degassed three times with H ₂ (23 ° C, 2 MPa) with vigorous stirring. The temperature of the reactor was raised to 100 ° C and the H ₂ pressure to 6 MPa. 123.9 g of a chlorobenzene solution consisting of Wilkinson's catalyst (0.337 g) and triphenylphosphine (5.18 g) were added and the pressure raised to 8.4 MPa while the reactor temperature was adjusted to 137-140 ° C has been. Both parameters were kept constant during the reaction. The course of the reaction was monitored by measuring the residual double bond content (RDB) of the unhydrogenated nitrile-diene-carboxylic acid ester copolymer by means of IR spectroscopy. The reaction was stopped after a maximum of 4 hours and / or reaching an RPV content of <1% by releasing the hydrogen pressure.

The resulting hydrogenated nitrile-diene carboxylic acid ester copolymer was isolated from the solution by steam coagulation. For this purpose, the chlorobenzene solution was diluted to a polymer content of 7 wt .-% and metered continuously into a stirred, filled with water and preheated to 100 ° C glass reactor. At the same time steam was introduced into the coagulation water at 0.5 bar. The thus precipitated polymer crumb was roughly dewatered and then dried at 55 ° C under vacuum to constant weight.

Table 4: Composition and properties of the hydrogenated nitrile-diene carboxylic acid ester copolymers (HNBR 1 to 8) (Examples according to the invention are marked with an asterisk *)

The hydrogenated nitrile-diene carboxylic acid ester copolymers of the invention are distinguished by a glass transition temperature Tg of -40 ° C. or less. III Preparation of Vulcanizates of the Hydrogenated Nitrile-Diene-Carboxylic Ester

Copolvmer (HNBR V1 to V8): Preparation of vulcanizable mixtures:

All rubber compounds were prepared on a mixing mill. The diameter of the rolls was 80 mm, the length 200 mm. The rolls were preheated to 40 ° C, the front roll speed was 16.5 RPM, the rear roll 20 PRM, achieving a friction of 1: 1, 2.

The rubber was charged and mixed for one (1) minute until a smooth rolled skin was formed. Subsequently, first the carbon black, then the additives and finally the crosslinking chemicals were mixed. Overall, the mixing time was 5 to 8 minutes.

Table 5: Composition and properties of the vulcanizate (HNBR V1 to V8: examples according to the invention are marked with an asterisk *).

gensc a en

u n

The terpolymer of Comparative Experiment V1 contains more than 25% by weight of α, β-ethylenically unsaturated carboxylic acid ester units but no PEG acrylate units. However, amounts of more than 25% by weight of butyl acrylate alone are insufficient to achieve a glass transition temperature of less than -40 ° C. in the vulcanizate.

The terpolymer of Comparative Experiment V2 contains more than 25% by weight of α, β-ethylenically unsaturated carboxylic acid ester units, namely methoxyethyl acrylate (PEG-1 acrylate), but no PEG-acrylate units having ethylene glycol repeating units of n> 1. However, amounts of more than 25% by weight of PEG-1 acrylate alone are insufficient to achieve a glass transition temperature of less than -40 ° C. in the vulcanizate.

The vulcanizates 3 to 8 according to the invention contain HNBR copolymer with at least 15% by weight of PEG-acrylate units (d) and at least two ethylene glycol repeating units.

The terpolymers of Runs V3 and V4 according to the invention each contain more than 25% by weight of PEG-2-MA and PEG-3-MA. The vulcanizates are characterized by a low glass transition temperature and a low swelling in I RM 903. The quaternary polymers of Experiments V5 to V8 according to the invention contain both PEG-3-MA and butyl acrylate wherein the amount of PEG-3-MA is in each case greater than 15% by weight and the total amount of carboxylic acid ester units is more than 25% by weight. The vulcanizates are characterized by a low glass transition temperature and a low swelling in I RM 903. As the amount of acrylonitrile units (a) increases, the glass transition temperature deteriorates. With an acrylonitrile content of more than 20% by weight, the glass transition temperature of the vulcanizate is no longer acceptable.

As the amount of PEG acrylate units (d) decreases, the swelling deteriorates. At a PEG acrylate content of less than 15% by weight, the swelling of the vulcanizate in I RM 903 is no longer acceptable. The vulcanizates according to the invention, which have terpolymers and quaternary polymers with PEG-2-MA repeat units, are furthermore also distinguished by the fact that they have a very particularly low content of gel.

The advantage of the invention is in particular that vulcanizates based on the hydrogenated nitrile-diene carboxylic acid ester copolymers of the invention

• a glass transition temperature of less than -40 ° C and

• have a swelling in IRM 903 of 51% or less.

In the combination of these properties, the hydrogenated nitrile-diene carboxylic acid ester copolymers of the present invention are superior to commercially available hydrogenated nitrile-diene carboxylic acid ester copolymers.

Claims

claims

1 . Hydrogenated nitrile-diene carboxylic acid ester copolymers containing

0.1 to 20% by weight of at least one α, β-ethylenically unsaturated nitrile unit,

15 to 74.9 wt .-% of at least one conjugated diene unit and

From 25 to 65% by weight of at least one α, β-ethylenically unsaturated carboxylic acid ester unit, at least 15% by weight, preferably at least 20% by weight, of the α, β-ethylenically unsaturated carboxylic acid ester units (c) based on the total amount of all monomer units of 100 Wt .-%, of a PEG acrylate (d) of the general formula (I)

Formula (I) are derived, wherein

R ¹ is hydrogen or CH ₃ -.

2. hydrogenated nitrile-diene carboxylic acid ester copolymers according to claim 1, comprising

(a) 1 to 19% by weight of at least one α, β-ethylenically unsaturated nitrile unit,

(b) 21 to 73% by weight of at least one conjugated diene unit and (C) 26 to 60 wt .-% of at least one α, β-ethylenically unsaturated carboxylic ester unit, wherein at least 15 wt .-%, preferably at least 20 wt .-% of α, β-ethylenically unsaturated carboxylic acid ester units (c) based on the total amount of all monomer units of 100% by weight, of a PEG acrylate (d) of the general formula (I)

Formula (I) are derived, wherein

R ¹ is hydrogen or CH ₃ -.

3. hydrogenated nitrile-diene carboxylic acid ester copolymers according to claim 1 or 2, comprising

(a) 8 to 18% by weight of at least one α, β-ethylenically unsaturated nitrile unit,

(b) 27 to 65% by weight of at least one conjugated diene unit and

(C) 27 to 55 wt .-% of at least one α, β-ethylenically unsaturated carboxylic ester unit, wherein at least 15 wt .-%, preferably at least 20 wt .-% of α, β-ethylenically unsaturated carboxylic acid ester units (c) based on the total amount of all monomer units of 100% by weight, of a PEG acrylate (d) of the general formula (I)

Formula (I) are derived, wherein

R is branched or unbranched -C ₂ o alkyl, preferably C ₂ -C ₂ o alkyl, more preferably ethyl, butyl or ethylhexyl, n is equal to 2 to 12, preferably 2 to 8, more preferably 2 to 5 and most is preferably 2 or 3 and is hydrogen or CH ₃ -.

Hydrogenated nitrile-diene-carboxylic acid ester copolymers according to one of claims 1 to 3, characterized in that the conjugated diene units (b) to 50% to 100%, preferably to 90% to 100%, particularly preferably to 99% to 100% and most preferably 99% to 100% are hydrogenated.

Hydrogenated nitrile-diene-carboxylic acid ester copolymers according to any one of claims 1 to 4, characterized in that the α, β-ethylenically unsaturated nitrile units (a) are acrylonitrile, methacrylonitrile, ethacrylonitrile or mixtures thereof, preferably acrylonitrile.

Hydrogenated nitrile-diene-carboxylic acid ester copolymers according to one of claims 1 to 5, characterized in that the conjugated diene units (b) 1, 3-butadiene, isoprene, 2,3-dimethylbutadiene, 1, 3-pentadienes (piperylene) or mixtures thereof, preferably 1, 3-butadiene.

Hydrogenated nitrile-diene carboxylic ester copolymers according to any one of claims 1 to 6, characterized in that the PEG acrylate units (c) are ethoxy, butoxy or ethylhexyloxy polyethylene glycol (meth) acrylate having from 2 to 12 ethylene glycol repeating units.

Hydrogenated nitrile-diene-carboxylic acid ester copolymers according to any one of claims 1 to 7, characterized in that the PEG-acrylate units (c) ethoxy or Butoxypolyethylenglycol (meth) acrylate having 2 to 5 ethylene glycol repeating units are.

9. hydrogenated nitrile-diene carboxylic acid ester copolymers according to any one of claims 1 to 8, characterized in that the PEG acrylate units (c) are ethoxy or Butoxypolyethylenglycol (meth) acrylate with 2 or 3 ethylene glycol repeating units.

10. hydrogenated nitrile-diene carboxylic acid ester copolymers according to any one of claims 1 to 9, characterized in that n is 2 or 3, R is ethyl or butyl and R ¹ is hydrogen or methyl.

1 1. Hydrogenated nitrile-diene-carboxylic acid ester copolymers according to any one of claims 1 to 10, characterized in that n is 2, R is butyl and R ¹ is methyl.

12. hydrogenated nitrile-diene carboxylic acid ester copolymers according to any one of claims 1 to 1 1, characterized in that they are copolymers containing 8 to 18 wt .-% acrylonitrile units, 27 to 65 wt .-% 1, 3-butadiene units and 27 to 55% by weight of PEG-2 acrylate units or PEG-3 acrylate units.

13. A process for preparing hydrogenated nitrile-diene carboxylic acid ester copolymers according to any one of claims 1 to 12, characterized in that at least one α, β-ethylenically unsaturated nitrile, at least one conjugated diene and at least one α, β-ethylenically unsaturated carboxylic acid ester Subjected to emulsion polymerization and then hydrogenated.

14. A process for preparing hydrogenated nitrile-diene carboxylic acid ester copolymers according to claim 13, characterized in that at least one α, β-ethylenically unsaturated nitrile, at least one conjugated diene and at least one PEG acrylate of the general formula (I) subjected to an emulsion be and then hydrogenated.

15. Vulcanisable mixtures containing hydrogenated nitrile-diene carboxylic acid ester copolymers according to any one of claims 1 to 12 and at least one crosslinker.

16. A process for the preparation of vulcanizable mixtures according to claim 15, by mixing a hydrogenated nitrile-diene carboxylic acid ester copolymer according to any one of claims 1 to 6 with at least one crosslinker.

17. A process for the preparation of vulcanizates, preferably as moldings, based on hydrogenated nitrile-diene carboxylic ester copolymers, characterized in that subjecting the vulcanizable mixture according to claim 15 to a vulcanization, preferably in a molding process at temperatures in the range of 100 ° C. up to 250 ° C.

18. A process for the preparation of vulcanizates, preferably as moldings, based on hydrogenated nitrile-diene carboxylic ester copolymers, characterized in that subjecting the vulcanizable mixture according to claim 15 to a vulcanization, preferably in a molding process and further preferably at temperatures in the range of 120 ° C to 250 ° C.

19. A process for the preparation of vulcanizates, preferably as moldings, based on hydrogenated nitrile-diene carboxylic ester copolymers, characterized in that subjecting the vulcanizable mixture according to claim 15 to a vulcanization, preferably in a molding process and further preferably at temperatures in the range of 130 ° C to 250 ° C.

20. vulcanizates based on hydrogenated nitrile-diene carboxylic acid ester copolymers according to any one of claims 1 to 12, obtainable by a process according to any one of claims 17 to 19.

21. Vulcanizates according to claim 20, characterized in that they are molded parts which are preferably selected from belts, gaskets, rollers, shoe components, hoses, damping elements, stators and cable sheaths, more preferably belts and seals.

22. Use of the hydrogenated nitrile-diene carboxylic acid ester copolymer according to one of claims 1 to 12 for the production of molded parts, preferably for the production of molded parts selected from the group consisting of belts, seals, rollers, shoe components, hoses, damping elements, stators and cable sheaths , particularly preferred for the production of belts and gaskets.