Nitrile rubbers having low emission values

Patent metadata

Field	Value
Publication number	US-2016108162-A1
Application number	US-201514976255-A
Country	US
Kind code	A1
Filing date	Dec 21, 2015
Priority date	Oct 14, 2013
Publication date	Apr 21, 2016
Grant date	—

Abstract

An improved polymerization process using a specific molecular weight regulator makes it possible to produce new nitrile rubbers featuring particularly low emission values and giving vulcanizates which have an advantageous profile of properties and which are of outstanding quality, in particular in odour-sensitive applications.

First claim

What is claimed is:

1 . A vulcanizable mixture comprising at least one crosslinker and a nitrile rubber comprising repeat units of at least one α,β-unsaturated nitrile monomer and at least one conjugated diene monomer, wherein the nitrile rubber has an emission quotient E according to general formula (I) of less than or equal to 0.25 mg/(kg*Mooney units)

E
=

[

volatile



constituents

]

[

Mooney



viscosity

]

×

[

nitrile



content

]

100

(
I
)

where
[volatile constituents] is the volatile constituents concentration in mg/kg of nitrile rubber determined by TDS GC-MS analysis according to VDA recommendation 278 (version September 2002) between 28.4 min and 34.0 min,
[Mooney viscosity] is the Mooney viscosity ML 1+4 at 100° C. of the nitrile rubber in Mooney units determined according to ASTM D 1646, and
[nitrile content] is the dimensionless α,β-unsaturated nitrile content in the nitrile rubber, wherein such content is determined in % by weight pursuant to DIN 53 625 according to Kjeldahl.

2 . The vulcanizable mixture according to claim 1 , wherein the nitrile rubber is prepared in emulsion in the presence of tertiary nonyl mercaptan, wherein the emulsion polymerization is carried out up to a conversion of at least 60% by weight, based on the sum of the monomers.

3 . The vulcanizable mixture according to claim 1 , wherein:
the nitrile rubber is prepared emulsion in the presence of tertiary nonyl mercaptan, wherein the emulsion polymerization is carried out up to a conversion of at least 60% by weight, based on the sum of the monomers; the at least one α,β-unsaturated nitrite monomer is selected from (C 3 -C 5 ) α,β-unsaturated nitrites and mixtures thereof; and the at least one conjugated diene monomer is selected from (C 4 -C 6 ) conjugated dienes and mixtures thereof.

4 . The vulcanizable mixture according to claim 1 , wherein:
the nitrile rubber is prepared in the presence of tertiary nonyl mercaptan; the at least one α,β-unsaturated nitrile monomer is selected from acrylonitrile, methacrylonitrile, ethacrylonitrile, and mixtures thereof; and the at least one conjugated diene monomer is selected from 1,2-butadiene, 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, piperylene and mixtures thereof.

5 . The vulcanizable mixture according to claim 1 , wherein:
the nitrile rubber is prepared in the presence of tertiary nonyl mercaptan; the at least one α,β-unsaturated nitrile monomer is acrylonitrile; and the at least one conjugated diene monomer is 1,3-butadiene.

6 . The vulcanizable mixture according to claim 1 , further comprising one or more fillers and no, one or more additional additive(s).

7 . The vulcanizable mixture according to claim 6 , wherein the one or more additional additives are selected from the group consisting of filler activators, antiozonants, ageing stabilizers, antioxidants, processing aids, extender oils, plasticizers, reinforcing materials and mould release agents.

8 . A process for producing the vulcanizable mixture according to claim 1 , the process comprising mixing together the nitrile rubber, the at least one crosslinker, and no, one or more further additive(s).

9 . A process for producing vulcanizates, the process comprising vulcanizing the vulcanizable mixture according to claim 1 .

10 . The process according to claim 9 , further comprising vulcanizing the vulcanizable mixture at a temperature of 100° C. to 200° C.

11 . The process according to claim 9 , further comprising vulcanizing the vulcanizable mixture at a temperature of 120° C. to 190° C.

12 . A vulcanizate comprising the nitrile rubber according to claim 1 .

13 . The vulcanizate according to claim 12 , wherein the vulcanizate is a shaped article.

14 . The vulcanizate according to claim 13 , wherein the vulcanizate is a drive belt, a roll covering, a seal, a cap, a stopper, a hose, a floor covering, a scaling mat or sheet, a profile or a membrane.

Assignees

• Lanxess Deutschland Gmbh

Inventors

• Brandau Sven
• Kaiser Andreas
• Magg Hans
• Westeppe Uwe

Classifications

• C08J2309/02

  Copolymers with acrylonitrile · CPC title

• C08F36/06 Primary

  Butadiene · CPC title

• C08F236/12 Primary

  with nitriles · CPC title

• C08K3/04

  Carbon · CPC title

• C08C1/14

  Coagulation · CPC title