CA2351961A1 - Low molecular weight nitrile rubber - Google Patents
Low molecular weight nitrile rubber Download PDFInfo
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- CA2351961A1 CA2351961A1 CA 2351961 CA2351961A CA2351961A1 CA 2351961 A1 CA2351961 A1 CA 2351961A1 CA 2351961 CA2351961 CA 2351961 CA 2351961 A CA2351961 A CA 2351961A CA 2351961 A1 CA2351961 A1 CA 2351961A1
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- nitrile rubber
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08C—TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
- C08C19/00—Chemical modification of rubber
- C08C19/08—Depolymerisation
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons
- C08L9/02—Copolymers with acrylonitrile
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Abstract
A low-molecular weight nitrile robber having narrower molecular weight distributions than those known in the art can be prepared by olefin metathesis.
Description
JUN-29-O1 12:50 Fron:BAYER SARNIA PATENT DEPT +519-339-1523 T-833 P.04/15 Job-_._____ _.______._____ ...________ _________ _________ ~y, gr~aiacuiwr '!'laightNitriia Rubbcr Field of the Invention.
The present invention relates to nitrite rubber polymers having lower molecular ~ weights and narrower molecular weight distributions than th4se known In the art.
Back rou~.,~,.,nd o~~ the invention Nitrite rubber (NBR), a co-polymer of a conjugated diene and an unsaturated nitrite, is a specialty rubber whioh has very chemical resistance, and i0 excellent oil resistance. Coupled with the high level of mechanical properties of the rubber (in particular the high resistanoe to abrasion) it is not surprising that NBR hoe found widoapr~ad use in the automotive (seats, hoses, bearing pads), electrical (cable sheathing), mechanical engineering (wheels, rollers) and footwear industries, amongst others.
IS
Commercially available N6R is manufacture k>y e~uisiort polymerization. The monomers are emulsified in water, a free radical-generating catalyst is added and the mixture is agitated whilst a constant temperature is maintained. After the desired degree of polymerization is reached, a shortstop and stabilizers are added to the ZO reaction system causing termination of the polymerization process.
Generally, NBR
obtained by this process has a Mooney viscosity in the Tango of from about 30 to about 94, an Mw in the range of from about 250,000 to about 350,000, an Mn in the range of from about 80,OC1n to about ~f50,060 and a pQlydispersify index greater than about 3.2.
25 fn addition, so-called "liquid NBR" having a very 14w Mooney viscosity and a low molecular weight can be produced be adding the shortstop agent early in the r$actian process. As in the case of regular NBR, the resulting liquid N~Fi has a poiydispersity greater than 3Ø
3o Karl Ziegler's discovery of tip ~'fa..aos ~ ~ ~ae~#el sa~r~,s, 4r.
combination with main group alfcylating agents, to promote olefin polymerization under mild conditions has had a signifioant impact on chemical re9earch and production to date. It was discovered early on that some "~iagier-type'~caiaiystsmvt-only-p-t~matr~tl~rrr----JUN-29-O1 12:51 From:BAYER SARNIA PATENT DEPT t519-339-1523 T-833 P.05/15 Job-proposed coordination-insertion mechanism but also effect an entirely different chemical process, that is the mutual exchange (or metathesis) reaction of alkenes R' R~ R~ R2 Catalyst R-R R
Flgurs 1 Acyctic diene metathesis (or ADMET) is catalyzed by a great variety of transition metal complexes as well as non-metallic systems. Heterogeneous catalyst systems based on metal oxides, sulfides or metal salts were originally used for the metathesis of olefins. However, the limited stability (especially towards hetoro-substituents) and the lack of selectivity resulting from the numerous active sites and aide reactions are major drawbacks of the hatorogeneous systems.
Homogeneous systems have also been devised and--u~d--to--gffect..ole#in ......-.
metathesis. These systems offer significant activity and control advantages over the heterogeneous catalyst systems. For example, certain Rhodium based complexes are effective catalysts for thg metathesis of electron-rich olefins.
The discovery that certain metal-alkylidene complexes art capable of catalyzing the rnetathesis of olefins triggered the development of a new generation of welhdeflned, highly active, single-site catalysts. Amongst thes$, Bls-(trlcyciahexylphosphine)-penzylidena ruthenium dichlorider (commonly knew as Grubb's catalyst) has been 2o widely used, dus to its remarkable insensitivity to air and moisture and high tolerance towards various functi~anal groups- Unlike the molybdenum-based metathesis catalysts.
this ruthenium carbene catalyst is stable to acids, aicohols, ai4ehydes and quaternaiy amine salts anal can be used in a variety of salvants (CBHB, CHzCl2. THF, a'BuOH). The most commonly-used catalysts are based on Mo, W and Ru.
The use of transition-metal catalyzed alkene metathesis has since enjoyed increasing attention as a synthetic method. Research efforts have been mainly focused on the synthesis of small molecules, but the application of olefin metatnesls to polymer JUN-29-O1 12:52 Fraa:BAYER SARNIA PATENT DEPT +519-339-1523 T-333 P.OSflS .139 synthesis has allowed the preparation of new polymeric material with unprecedented properties (such as highly stereoregular poly-norbornadiene).
The utilization of olefin metathesis as a means to produce low molecular weight S compounds from unsaturated elastomers has received growing interest. The principle for the molecular weight reduction of unsaturated polymsrs Is shown in Figure ~. The use of an appropriate cz~taiyst allows the cross-metathesis of the unsatatr$tioc~-of--th$- -----polymer with the co-olefin. The end result ie the cleavage df the polymer chain at tho unsaturation sites and the generation of polymer fragments Raving lower molecular i0 weights. In addition, another effect of this process is the "homogenizing"
of the polymer chairs lengths, resulting in a reduction of the polydispersity. From an application and processing stand point, a narrow molecular weight distribution of the caw polymer results in improved physical properties of the vulcanized rubber, whilst the lower molecular weight provides good processing behavior.
!/
cac __ __ ___ _ ________ __ __ _ _ __ ~g~_2 ~eie_ef pfatfy ~nsatureted Polymer The so-call~d "dopalymeriaation" of copolymers of 1,S-fJUtadiens with a variety of cd-monomers (styrene, propane, divinylbenzene and ethylvinylbenzene, acrylonitrile, vinyltrimathylsilane and divinyldimethylsilane) in the presence of classical Mo and W
catalyst system has been investigated. Similarly, the degradation of a nitrite rubber using WCh and SnMe4 or PhC~CH co,catalyst was reported in 1988_ However, the focus of such research was to produce only low molecular fragments which could be characterized by conventional chemical means and contains no teaching with respect to JUN-29-01 12:53 Fro~:BAYER SARNIA PATENT DEPT +519-339-1523 T-B33 P.OT/15 Job-the preparatlan of low molecular weight nitrite rubber polymers. Furthermore, such processes are non-controlled and produce a wide range of products.
The catalytic depofymeriaation of 1,4-palybutadiene in the presence of substituted olefins or ethylene (as chain transfer agastts)-irt t~o-presenEe~f-wei4-da#Ined--- --. ---Grubb's or Schrock's catalysts is also possible. The use of Molybdenum or Tungsten compounds of the general structural fmmuia {t~(~hifp)tC~ftz3at~~3T ~ _ ~~ W
produce low molecular weight poiymara or oligamer~ from gelled polymers containing internal unsaturation along the polymer backbone was claimeri-in-U~'rF;~4fi;1G2: Again;
!o however, the process disclosed is non-controlled, and there is no teaching with respect to the preparation of law malecrLtlar weight nitrite rubber polymers.
Summarx of the Inventlan We have now discovered that a low molecular weight nitrlle rubber having narrower rnalecular weight distributions than those known in the art can be prepared by olefin metathesis. Rubbers having a narrow molecular walght distribution have certain advantages over those having a broad molecular weight dlstrlbutian, one of th~ase being that they have improved physical properties, resulting, for example, in better prooesaability of the rubber.
Thus, one aspect of the disclosed invention is a nitrite rubber having a molecular weight (Mw) in the range of from about 25,000 to about 2Gu,uDir, r~ Moonay viscositg-- -----(MI- 1 t~l i 00) of less than about 25, and a MW D (or polydispersity index) of less than about 2.5.
pescription of the Invention As used throughout this specification, the term "nitrIle rubbed" is intended to have a broad meaning and is meant to encompass a copolymer of a conjugated dlene and an unsaturated nitrite.
The conjugated diene may be a C4-C6 conjugated diene. Non-limiting examples of suitable such conjugated dienes may be aeleoted from the group comprising butadiene, isoprene, piperylene, 2,3-dimethyl butadiene and mixtures thereof.
The preferred Ce-Ce conjugated dlene may be selected from the group comprising JUN-29-01 12:58 Fram:BAYER SARNIA PATENT DEPT +519-339-1523 T-934 P.09/15 Jab-butadiene, isoprene and mixtures thereof. The most preferred ~'-CR conjugated diene is butadiene.
The unsaturated nitrite may be a C3-Cs a,~-unsaturatad nitrite. Nan-limiting examples of suitable such C3-Cs a,~~unsaturated nitrites may ba selected from the group comprising acrylonitrile, mathacrylonitrile, ethacrylonitrlle and mixtures thereof.
The most pref~rred C3-Cs a,~-unsaturated nitrite is acrylonitrile.
Preferably, the copolymer comprises from about 40 to about 85 weight percent of the copolymer of bound conjugated diene and from about 1 S to about GO
weight peroar<t of the copolym~ar of bound unsaturated nitrite. More pref~9rably, the copolymer comprises from about 60 to about 75 weight percent of the copolymer of bound conjugated diene and from about 25 to 2~bout AO weight percent of the copolym9r of bound unsaturated rlitrile. Mast preferably, the copolymer comprises from about BO to about 74 weight percent of the copolymer of bound aanjugatad diene and from about 30 to about 40 weight percent of the copolymer of bound unsaturated nitrite.
Optionally, the copolymer may further comprise a bound unsaturated carboxylic acid. Non-limiting examples 4f suitablQ such bound unsaturated carboxylic acids may ba selected frr~m the group comprising fumario acid, maleia acid, acrylic acid, methscrylio acid and mixtures thereof. The bound unsaturated carboxylic acid may be present in an amount of from about 1 to about 10 weight percent of the copolymer, with this amount displacing a corresponding amount of the conjugated diolefin.
Further, a third monomer may be used in production of the nitrite polymer.
Preferably, the third monomer is an unsaturated mono- ar di-carboxylic acid or derivative thereo#-{~r g-.; ester; arnidos-and- the-like~).-The metathesis reaGtian can be catalysed by compounds of formula I, II ar.lll:
as shown below JUN-29-01 12:59 From:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.09/15 Job-L
X~ ~ -... ~Fi ~M C' Xt ~ '~Ri L~
Formula I
wherein:
M is 4s Qr Ru;
R and R' are, independently, hydrogen or a hydrocarbon selected f~oin the group_consisting of C~-Coo alkenyl, Ca-Gzo alkynyl, C~-C?fl alkyl, aryl, Ci-Coo carboxylate, Ci-Czo alkoxy, C2-Coo alkenyloxy, Cz-C2o alkyrtyloxy, aryloxy, Cz-C~
alkoxycarbonyl, C~_ C2o aikylthio, C1-C~ alkylsulfonyl and Gi-C~zo alkylsulfinyl;
X and X' are independently selected anionic ligands; and L and L' are, independently, ligands selected from the group consisting of 1o phosphines, sulf4nated phosphinea, fluorinated phosphines, functlonallzed phosphlnes having up to three amlnoalkyl-, ammonlumalkyl-, alkoxyalkyl-, alkoxykx~rbonylalkyl-, hydrocycarbonylalkyl-, hydroxyalkyl- or ketoaikyl- groups, phosphites, phosphinites, phosphonitaa, phosphinaminos, arcinas, stibine$, ethers, amines, amides, imines, sulfoxides, thiaethers and pyridines; optionally. L and L' can be linked to one another to from a bidentate neutral (igand wherein at least one of the above-mentioned functional groups is present.
Lz Ra M'-"~ G~ C~ C
xa/
Formula II
wherein:
2o M' is Os or Ru;
R2 and R~ are, independently, hydrogen or a hydrocarbon selected from the group consisting of C~-Coo aiker~yi, Cz-C~ alkynyi, Ct-G~ alkyl, aryl, C~-Cue, carboxylat~e, Ct_ JUN-29-01 13:00 Fron~:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.10/15 Job-C~ alkoxy, C2-~~ aikenyloxy, Gz-Cao alkynyloxy, aryloxy, C~-C2o alkoxycarbonyl, C~-C2o alkylthio, C1-Cao alkylsulfonyl and C,-G2o alkyl5ulf inyl;
X2 is selected from any anionic ligand; and L2 is a neutral n-bonded ligand, preferably but not limited to arena, substituted arena, heteroarene, independent of whether they are mono- or polycyclic;
L3 is a Ilgand selected from the group consisting of phosphines, sulfonated phosphines, fluorinated pllospnlnes, functlonallzed phosphlnes bearing up to three amino&Iltyl-, ammoniumalkyl-, alkoxyalkyl-, alkoxylcr~rbanylalkyl-, hydrocycarbonylaikyl-, hydroxyalkyl- or ket4alkyl- groups, phasphites, phosphinites, phosphonites, ip phcsphlnamlnoe, arsines, stibenQS, ethers, amines, amides, (mines.
sulfoxidas, thioethers and pyridines;
Y' is a non-coordinating anion;
n is an integer in the range of from 0 to 5;
f~R~2 ~R
OR 2-M ~C~
Ra N
s R
i5 Formula III
wherein M2 is Mo or W
R4, Rs are, independently, hydrogen or a hydrocarlaort selected frorrs tl~e group consisting of C2-Coo alkenyl, Ca-Cao aikynyl, Cy-Cao alkyl, aryl, C,-C2o carboxylate, Ci 20 C~ alkoxy, Cz-Cao alkenyloxy, C2-C2o alKynyloxy, aryloxy, Ga-C2o alkoxycarbonyl, C,-C2a alkylttllo, C1-C2o alkylsutfonyl and C~-G~ a+kylsu6#'+nyl;
R6 and »' are independently selected from any unsubstitutQd ar halo-substituted alkyl, aryl, aralkyl groups or silicon-containing analogs thereof.
25 r~atalysts of Formula I are preferred. More preferably, catalysts of Formula I
wherein L, and 1-1 are trialkylphosphines, X and X' are chloride ions anti IUI
is Ruthenium are preferred.
The present invention relates to nitrite rubber polymers having lower molecular ~ weights and narrower molecular weight distributions than th4se known In the art.
Back rou~.,~,.,nd o~~ the invention Nitrite rubber (NBR), a co-polymer of a conjugated diene and an unsaturated nitrite, is a specialty rubber whioh has very chemical resistance, and i0 excellent oil resistance. Coupled with the high level of mechanical properties of the rubber (in particular the high resistanoe to abrasion) it is not surprising that NBR hoe found widoapr~ad use in the automotive (seats, hoses, bearing pads), electrical (cable sheathing), mechanical engineering (wheels, rollers) and footwear industries, amongst others.
IS
Commercially available N6R is manufacture k>y e~uisiort polymerization. The monomers are emulsified in water, a free radical-generating catalyst is added and the mixture is agitated whilst a constant temperature is maintained. After the desired degree of polymerization is reached, a shortstop and stabilizers are added to the ZO reaction system causing termination of the polymerization process.
Generally, NBR
obtained by this process has a Mooney viscosity in the Tango of from about 30 to about 94, an Mw in the range of from about 250,000 to about 350,000, an Mn in the range of from about 80,OC1n to about ~f50,060 and a pQlydispersify index greater than about 3.2.
25 fn addition, so-called "liquid NBR" having a very 14w Mooney viscosity and a low molecular weight can be produced be adding the shortstop agent early in the r$actian process. As in the case of regular NBR, the resulting liquid N~Fi has a poiydispersity greater than 3Ø
3o Karl Ziegler's discovery of tip ~'fa..aos ~ ~ ~ae~#el sa~r~,s, 4r.
combination with main group alfcylating agents, to promote olefin polymerization under mild conditions has had a signifioant impact on chemical re9earch and production to date. It was discovered early on that some "~iagier-type'~caiaiystsmvt-only-p-t~matr~tl~rrr----JUN-29-O1 12:51 From:BAYER SARNIA PATENT DEPT t519-339-1523 T-833 P.05/15 Job-proposed coordination-insertion mechanism but also effect an entirely different chemical process, that is the mutual exchange (or metathesis) reaction of alkenes R' R~ R~ R2 Catalyst R-R R
Flgurs 1 Acyctic diene metathesis (or ADMET) is catalyzed by a great variety of transition metal complexes as well as non-metallic systems. Heterogeneous catalyst systems based on metal oxides, sulfides or metal salts were originally used for the metathesis of olefins. However, the limited stability (especially towards hetoro-substituents) and the lack of selectivity resulting from the numerous active sites and aide reactions are major drawbacks of the hatorogeneous systems.
Homogeneous systems have also been devised and--u~d--to--gffect..ole#in ......-.
metathesis. These systems offer significant activity and control advantages over the heterogeneous catalyst systems. For example, certain Rhodium based complexes are effective catalysts for thg metathesis of electron-rich olefins.
The discovery that certain metal-alkylidene complexes art capable of catalyzing the rnetathesis of olefins triggered the development of a new generation of welhdeflned, highly active, single-site catalysts. Amongst thes$, Bls-(trlcyciahexylphosphine)-penzylidena ruthenium dichlorider (commonly knew as Grubb's catalyst) has been 2o widely used, dus to its remarkable insensitivity to air and moisture and high tolerance towards various functi~anal groups- Unlike the molybdenum-based metathesis catalysts.
this ruthenium carbene catalyst is stable to acids, aicohols, ai4ehydes and quaternaiy amine salts anal can be used in a variety of salvants (CBHB, CHzCl2. THF, a'BuOH). The most commonly-used catalysts are based on Mo, W and Ru.
The use of transition-metal catalyzed alkene metathesis has since enjoyed increasing attention as a synthetic method. Research efforts have been mainly focused on the synthesis of small molecules, but the application of olefin metatnesls to polymer JUN-29-O1 12:52 Fraa:BAYER SARNIA PATENT DEPT +519-339-1523 T-333 P.OSflS .139 synthesis has allowed the preparation of new polymeric material with unprecedented properties (such as highly stereoregular poly-norbornadiene).
The utilization of olefin metathesis as a means to produce low molecular weight S compounds from unsaturated elastomers has received growing interest. The principle for the molecular weight reduction of unsaturated polymsrs Is shown in Figure ~. The use of an appropriate cz~taiyst allows the cross-metathesis of the unsatatr$tioc~-of--th$- -----polymer with the co-olefin. The end result ie the cleavage df the polymer chain at tho unsaturation sites and the generation of polymer fragments Raving lower molecular i0 weights. In addition, another effect of this process is the "homogenizing"
of the polymer chairs lengths, resulting in a reduction of the polydispersity. From an application and processing stand point, a narrow molecular weight distribution of the caw polymer results in improved physical properties of the vulcanized rubber, whilst the lower molecular weight provides good processing behavior.
!/
cac __ __ ___ _ ________ __ __ _ _ __ ~g~_2 ~eie_ef pfatfy ~nsatureted Polymer The so-call~d "dopalymeriaation" of copolymers of 1,S-fJUtadiens with a variety of cd-monomers (styrene, propane, divinylbenzene and ethylvinylbenzene, acrylonitrile, vinyltrimathylsilane and divinyldimethylsilane) in the presence of classical Mo and W
catalyst system has been investigated. Similarly, the degradation of a nitrite rubber using WCh and SnMe4 or PhC~CH co,catalyst was reported in 1988_ However, the focus of such research was to produce only low molecular fragments which could be characterized by conventional chemical means and contains no teaching with respect to JUN-29-01 12:53 Fro~:BAYER SARNIA PATENT DEPT +519-339-1523 T-B33 P.OT/15 Job-the preparatlan of low molecular weight nitrite rubber polymers. Furthermore, such processes are non-controlled and produce a wide range of products.
The catalytic depofymeriaation of 1,4-palybutadiene in the presence of substituted olefins or ethylene (as chain transfer agastts)-irt t~o-presenEe~f-wei4-da#Ined--- --. ---Grubb's or Schrock's catalysts is also possible. The use of Molybdenum or Tungsten compounds of the general structural fmmuia {t~(~hifp)tC~ftz3at~~3T ~ _ ~~ W
produce low molecular weight poiymara or oligamer~ from gelled polymers containing internal unsaturation along the polymer backbone was claimeri-in-U~'rF;~4fi;1G2: Again;
!o however, the process disclosed is non-controlled, and there is no teaching with respect to the preparation of law malecrLtlar weight nitrite rubber polymers.
Summarx of the Inventlan We have now discovered that a low molecular weight nitrlle rubber having narrower rnalecular weight distributions than those known in the art can be prepared by olefin metathesis. Rubbers having a narrow molecular walght distribution have certain advantages over those having a broad molecular weight dlstrlbutian, one of th~ase being that they have improved physical properties, resulting, for example, in better prooesaability of the rubber.
Thus, one aspect of the disclosed invention is a nitrite rubber having a molecular weight (Mw) in the range of from about 25,000 to about 2Gu,uDir, r~ Moonay viscositg-- -----(MI- 1 t~l i 00) of less than about 25, and a MW D (or polydispersity index) of less than about 2.5.
pescription of the Invention As used throughout this specification, the term "nitrIle rubbed" is intended to have a broad meaning and is meant to encompass a copolymer of a conjugated dlene and an unsaturated nitrite.
The conjugated diene may be a C4-C6 conjugated diene. Non-limiting examples of suitable such conjugated dienes may be aeleoted from the group comprising butadiene, isoprene, piperylene, 2,3-dimethyl butadiene and mixtures thereof.
The preferred Ce-Ce conjugated dlene may be selected from the group comprising JUN-29-01 12:58 Fram:BAYER SARNIA PATENT DEPT +519-339-1523 T-934 P.09/15 Jab-butadiene, isoprene and mixtures thereof. The most preferred ~'-CR conjugated diene is butadiene.
The unsaturated nitrite may be a C3-Cs a,~-unsaturatad nitrite. Nan-limiting examples of suitable such C3-Cs a,~~unsaturated nitrites may ba selected from the group comprising acrylonitrile, mathacrylonitrile, ethacrylonitrlle and mixtures thereof.
The most pref~rred C3-Cs a,~-unsaturated nitrite is acrylonitrile.
Preferably, the copolymer comprises from about 40 to about 85 weight percent of the copolymer of bound conjugated diene and from about 1 S to about GO
weight peroar<t of the copolym~ar of bound unsaturated nitrite. More pref~9rably, the copolymer comprises from about 60 to about 75 weight percent of the copolymer of bound conjugated diene and from about 25 to 2~bout AO weight percent of the copolym9r of bound unsaturated rlitrile. Mast preferably, the copolymer comprises from about BO to about 74 weight percent of the copolymer of bound aanjugatad diene and from about 30 to about 40 weight percent of the copolymer of bound unsaturated nitrite.
Optionally, the copolymer may further comprise a bound unsaturated carboxylic acid. Non-limiting examples 4f suitablQ such bound unsaturated carboxylic acids may ba selected frr~m the group comprising fumario acid, maleia acid, acrylic acid, methscrylio acid and mixtures thereof. The bound unsaturated carboxylic acid may be present in an amount of from about 1 to about 10 weight percent of the copolymer, with this amount displacing a corresponding amount of the conjugated diolefin.
Further, a third monomer may be used in production of the nitrite polymer.
Preferably, the third monomer is an unsaturated mono- ar di-carboxylic acid or derivative thereo#-{~r g-.; ester; arnidos-and- the-like~).-The metathesis reaGtian can be catalysed by compounds of formula I, II ar.lll:
as shown below JUN-29-01 12:59 From:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.09/15 Job-L
X~ ~ -... ~Fi ~M C' Xt ~ '~Ri L~
Formula I
wherein:
M is 4s Qr Ru;
R and R' are, independently, hydrogen or a hydrocarbon selected f~oin the group_consisting of C~-Coo alkenyl, Ca-Gzo alkynyl, C~-C?fl alkyl, aryl, Ci-Coo carboxylate, Ci-Czo alkoxy, C2-Coo alkenyloxy, Cz-C2o alkyrtyloxy, aryloxy, Cz-C~
alkoxycarbonyl, C~_ C2o aikylthio, C1-C~ alkylsulfonyl and Gi-C~zo alkylsulfinyl;
X and X' are independently selected anionic ligands; and L and L' are, independently, ligands selected from the group consisting of 1o phosphines, sulf4nated phosphinea, fluorinated phosphines, functlonallzed phosphlnes having up to three amlnoalkyl-, ammonlumalkyl-, alkoxyalkyl-, alkoxykx~rbonylalkyl-, hydrocycarbonylalkyl-, hydroxyalkyl- or ketoaikyl- groups, phosphites, phosphinites, phosphonitaa, phosphinaminos, arcinas, stibine$, ethers, amines, amides, imines, sulfoxides, thiaethers and pyridines; optionally. L and L' can be linked to one another to from a bidentate neutral (igand wherein at least one of the above-mentioned functional groups is present.
Lz Ra M'-"~ G~ C~ C
xa/
Formula II
wherein:
2o M' is Os or Ru;
R2 and R~ are, independently, hydrogen or a hydrocarbon selected from the group consisting of C~-Coo aiker~yi, Cz-C~ alkynyi, Ct-G~ alkyl, aryl, C~-Cue, carboxylat~e, Ct_ JUN-29-01 13:00 Fron~:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.10/15 Job-C~ alkoxy, C2-~~ aikenyloxy, Gz-Cao alkynyloxy, aryloxy, C~-C2o alkoxycarbonyl, C~-C2o alkylthio, C1-Cao alkylsulfonyl and C,-G2o alkyl5ulf inyl;
X2 is selected from any anionic ligand; and L2 is a neutral n-bonded ligand, preferably but not limited to arena, substituted arena, heteroarene, independent of whether they are mono- or polycyclic;
L3 is a Ilgand selected from the group consisting of phosphines, sulfonated phosphines, fluorinated pllospnlnes, functlonallzed phosphlnes bearing up to three amino&Iltyl-, ammoniumalkyl-, alkoxyalkyl-, alkoxylcr~rbanylalkyl-, hydrocycarbonylaikyl-, hydroxyalkyl- or ket4alkyl- groups, phasphites, phosphinites, phosphonites, ip phcsphlnamlnoe, arsines, stibenQS, ethers, amines, amides, (mines.
sulfoxidas, thioethers and pyridines;
Y' is a non-coordinating anion;
n is an integer in the range of from 0 to 5;
f~R~2 ~R
OR 2-M ~C~
Ra N
s R
i5 Formula III
wherein M2 is Mo or W
R4, Rs are, independently, hydrogen or a hydrocarlaort selected frorrs tl~e group consisting of C2-Coo alkenyl, Ca-Cao aikynyl, Cy-Cao alkyl, aryl, C,-C2o carboxylate, Ci 20 C~ alkoxy, Cz-Cao alkenyloxy, C2-C2o alKynyloxy, aryloxy, Ga-C2o alkoxycarbonyl, C,-C2a alkylttllo, C1-C2o alkylsutfonyl and C~-G~ a+kylsu6#'+nyl;
R6 and »' are independently selected from any unsubstitutQd ar halo-substituted alkyl, aryl, aralkyl groups or silicon-containing analogs thereof.
25 r~atalysts of Formula I are preferred. More preferably, catalysts of Formula I
wherein L, and 1-1 are trialkylphosphines, X and X' are chloride ions anti IUI
is Ruthenium are preferred.
- JUN-29-01 13:00 From:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.11/15 Job-539 The amount of catalyst employed in the metathesis reaction will depend upon the nature and activity of the catalyst in question. 'Typically, the ratio of catalyst to NBR
is in the range of from about d.OgS to about 5, preferably in the range of from about S 0.025 to about 1 and, more preferably, in the range of from about 0.1 to about 0.5.
Tne metathesls reaction Is carried out in the presence of a co-olefin which is a C, to Cia linear or branched olefin such as ethylene, isobutene, styrene or 1-h~xane.
Where the co-olefin is a liquid (such as 1-hexane), the amount of co-olefin employed is 1o in tho range of from about 1 to about 50 weight %; preferably in the ran06 of from about to about 30 weight %. Where the oo-olefin is a gas (such as ethylene) the amount -- ' ~~ - of co-oletiri-evripidjrod-is such-ti~lar-it-results-inw-presst~rawin thwr~action vessel in the range of from about 15 to about 1540 psi, preferably in the range of from about 75 to about 600 psi.
The metathssis reaction can be carried out in any suitable solvent which does not inactivate the Catalyst or otherwise intertere with the reaction.
Preferred solvents include, but are not limited to, dichloromethane, benzene, toluene, tetrahydrofuran, cylcohexana and the likd. The moat preferred solvent is monochlorobenzena (MCB).
In curtain cases th~ ca-of~fin can itself act as a solvent (for example, 1-hexane). in which case no other solvent is necessary.
The concentration of N6R in the reaction mixture is not critical but, obviously, should be such that the reaction is not hampered if the mixture is too viscous to be 2~ stirred efficiently, for example. Preferably, the concentration of.":~~:-ia.-1n .the r:nge-of"~- "
from about 1 to about 20%, most preferably in the range of from about 6 to about i 5%.
The metath98is reaCtiOr~ Is carried out at a temperature In the range of from about 20 to about 140qC; preferably in the range of from about 80 to about 120$C.
The reaction time will depend upon a number of factors, including cement concentration, amount of catalyst used and the temperature at which the reaction is performed. The metathesis is complete within the first two hours under typical conditions. The progress of the metathesis reaction may ba monitored by standard analytical techniques, for example using C PC or solution viscosity .
is in the range of from about d.OgS to about 5, preferably in the range of from about S 0.025 to about 1 and, more preferably, in the range of from about 0.1 to about 0.5.
Tne metathesls reaction Is carried out in the presence of a co-olefin which is a C, to Cia linear or branched olefin such as ethylene, isobutene, styrene or 1-h~xane.
Where the co-olefin is a liquid (such as 1-hexane), the amount of co-olefin employed is 1o in tho range of from about 1 to about 50 weight %; preferably in the ran06 of from about to about 30 weight %. Where the oo-olefin is a gas (such as ethylene) the amount -- ' ~~ - of co-oletiri-evripidjrod-is such-ti~lar-it-results-inw-presst~rawin thwr~action vessel in the range of from about 15 to about 1540 psi, preferably in the range of from about 75 to about 600 psi.
The metathssis reaction can be carried out in any suitable solvent which does not inactivate the Catalyst or otherwise intertere with the reaction.
Preferred solvents include, but are not limited to, dichloromethane, benzene, toluene, tetrahydrofuran, cylcohexana and the likd. The moat preferred solvent is monochlorobenzena (MCB).
In curtain cases th~ ca-of~fin can itself act as a solvent (for example, 1-hexane). in which case no other solvent is necessary.
The concentration of N6R in the reaction mixture is not critical but, obviously, should be such that the reaction is not hampered if the mixture is too viscous to be 2~ stirred efficiently, for example. Preferably, the concentration of.":~~:-ia.-1n .the r:nge-of"~- "
from about 1 to about 20%, most preferably in the range of from about 6 to about i 5%.
The metath98is reaCtiOr~ Is carried out at a temperature In the range of from about 20 to about 140qC; preferably in the range of from about 80 to about 120$C.
The reaction time will depend upon a number of factors, including cement concentration, amount of catalyst used and the temperature at which the reaction is performed. The metathesis is complete within the first two hours under typical conditions. The progress of the metathesis reaction may ba monitored by standard analytical techniques, for example using C PC or solution viscosity .
JUN-29-01 13:01 Fro~:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.12/15 Job-The Mooney viscosity of the rubber was determined using AaTM test D164B.
Por a typical product the Mn is about 30,000 (compared to about 85,D00 far the starting polymer) whilst the Mw is about 65,000 (compared to 300,040 for the starting polymer. As can be seen from Table 1, however, higher molecular weights (Mw) can also be obtained by manipulation of the experimental conditions (for example by loworing the catalyst loading). As expected, the molecular weight distribution fall9 from about 3.5 for the starting NMB feedstock to about 2.0 for the metatheslzed product.
This is consistent with a more homogeneous range of polymer chain lengths and malQCUlar wQights.
A summary of the polymer properties for selected samples is shown in Table 1.
The GPC results show up to a fivefold reduction in Mw arid a narrowing of the polydispersity index to about 2Ø
is Table 1 Summary of Polymer Praperkles MN MW MZ PDI Mooney Vi9oosity (ML i+4 ~ ~~;
Starting N6R 86000 268000 839000 3.60 35 (Parbunan) Experiment 1 27000 54000 9204Q 2.00 2.5 Experiment 2 27000 b3000 890D0 1.98 -Experlment 3 32000 66000 117040 2.06 -F-~cperiment 4 67000 134000 253000 2.00 -Exporrlmental Details Ris(tricyolohexylphosphino)banzylidene ruth~nium c#iohloride (Crubb's metathesis catalyst), 1-hexen~.and monochlorobanzene (MGS) were purchased from Alfa, Aldrich Chemicals. and PPG respectively and used as received. Perbunan was obtained from Bayer Inc. .
Por a typical product the Mn is about 30,000 (compared to about 85,D00 far the starting polymer) whilst the Mw is about 65,000 (compared to 300,040 for the starting polymer. As can be seen from Table 1, however, higher molecular weights (Mw) can also be obtained by manipulation of the experimental conditions (for example by loworing the catalyst loading). As expected, the molecular weight distribution fall9 from about 3.5 for the starting NMB feedstock to about 2.0 for the metatheslzed product.
This is consistent with a more homogeneous range of polymer chain lengths and malQCUlar wQights.
A summary of the polymer properties for selected samples is shown in Table 1.
The GPC results show up to a fivefold reduction in Mw arid a narrowing of the polydispersity index to about 2Ø
is Table 1 Summary of Polymer Praperkles MN MW MZ PDI Mooney Vi9oosity (ML i+4 ~ ~~;
Starting N6R 86000 268000 839000 3.60 35 (Parbunan) Experiment 1 27000 54000 9204Q 2.00 2.5 Experiment 2 27000 b3000 890D0 1.98 -Experlment 3 32000 66000 117040 2.06 -F-~cperiment 4 67000 134000 253000 2.00 -Exporrlmental Details Ris(tricyolohexylphosphino)banzylidene ruth~nium c#iohloride (Crubb's metathesis catalyst), 1-hexen~.and monochlorobanzene (MGS) were purchased from Alfa, Aldrich Chemicals. and PPG respectively and used as received. Perbunan was obtained from Bayer Inc. .
- JUN-29-01 13.02 Fron~:BAYER SARNIA PATENT DEPT +519-339-1523 T-834 P.13/15 Job-539 The metathesis reactions wars carried out in a Parr high-pressure reactor under the following conditions:
Cement Concentration 6 or 15%
Co-Oiefin Ethylene or 1-Hexena Co ~Ofefin Concentration Variable Agitator Speed soo rpm Reactor Temperature Variable Catalyst Loading Variable Solvent Monachlorobenzene 1o Substrate Perbunan NT 3435 T
Perbunan NT 3429 T
In a typical lab experiment, 200g of rubb~r was dissolved in 1133g of MCB (15%
solid). The cement was then charged to the reactor and degassed 3 times with C~H4 15 (l00 psi) under full agitation. The reactor was heated to desired temperature and BomL
of a monachlorobenzene solution containing Grubb's catalyst was added to the reactor.
The temperature was rnalntained constant for tile duration of the reaction. A
cooling coil connected to a temperature controller and a thermal sensor was used to regulate the temperature. The progreaa of the reaction was monitorQd using solutlan viscosity 20 moacurements for the 6°/q cQments. At higher cement concentration.
the reaction was assumed to be complete after 18 hours.
Cement Concentration 6 or 15%
Co-Oiefin Ethylene or 1-Hexena Co ~Ofefin Concentration Variable Agitator Speed soo rpm Reactor Temperature Variable Catalyst Loading Variable Solvent Monachlorobenzene 1o Substrate Perbunan NT 3435 T
Perbunan NT 3429 T
In a typical lab experiment, 200g of rubb~r was dissolved in 1133g of MCB (15%
solid). The cement was then charged to the reactor and degassed 3 times with C~H4 15 (l00 psi) under full agitation. The reactor was heated to desired temperature and BomL
of a monachlorobenzene solution containing Grubb's catalyst was added to the reactor.
The temperature was rnalntained constant for tile duration of the reaction. A
cooling coil connected to a temperature controller and a thermal sensor was used to regulate the temperature. The progreaa of the reaction was monitorQd using solutlan viscosity 20 moacurements for the 6°/q cQments. At higher cement concentration.
the reaction was assumed to be complete after 18 hours.
Claims (11)
1. A nitrile rubber having a molecular weight (Mw) in the range of from about 25,000 to about 200,000 and a polydispersity index of less than about 2.5.
2. A nitrile rubber according to claim 1 wherein the molecular weight (Mw) is in the range of from about 40,000 to about 180,000.
3. A nitrile rubber according to claim 1 wherein the molecular weight (Mw) is in the range of from about 50,000 to about 10,000.
4. A nitrile rubber according to claim 1 wherein the polydispersity index is less than about 2.3.
5. A nitrile rubber according to claim 2 wherein the polydispersity index is less than about 2.3.
6. A nitrile rubber according to claim 3 wherein the polydispersity index is less than about 2.3.
7. A nitrile rubber according to claim 1 wherein the polydispersity index is less than about 2.1.
8. A nitrile rubber according to claim 3 wherein the polydispersity index is less than about 2.1.
9. A nitrite rubber according to claim 3 wherein the polydispersity index is less than about 2.1.
10. The use of a nitrile rubber according to claim 1 in the manufacture of a seal, hose, bearing pad, stator, well head seal, valve plate, cable sheathing, wheel, roller, pipe seal or footwear component.
11
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2351961 CA2351961A1 (en) | 2001-06-29 | 2001-06-29 | Low molecular weight nitrile rubber |
| US10/167,139 US6841623B2 (en) | 2001-06-29 | 2002-06-10 | Low molecular weight nitrile rubber |
| PCT/CA2002/000965 WO2003002613A1 (en) | 2001-06-29 | 2002-06-11 | Low molecular weight nitrile rubber |
| EP02734964A EP1425312A1 (en) | 2001-06-29 | 2002-06-11 | Low molecular weight nitrile rubber |
| TW091114242A TWI261058B (en) | 2001-06-29 | 2002-06-28 | Low molecular weight nitrile rubber |
| US10/926,532 US7745539B2 (en) | 2001-06-29 | 2004-08-26 | Low molecular weight nitrite rubber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2351961 CA2351961A1 (en) | 2001-06-29 | 2001-06-29 | Low molecular weight nitrile rubber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2351961A1 true CA2351961A1 (en) | 2002-12-29 |
Family
ID=4169383
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2351961 Abandoned CA2351961A1 (en) | 2001-06-29 | 2001-06-29 | Low molecular weight nitrile rubber |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2351961A1 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004035670A1 (en) | 2002-10-17 | 2004-04-29 | Bayer Inc. | Polymer composites comprising low molecular weight nitrile rubber |
| WO2004035669A1 (en) | 2002-10-17 | 2004-04-29 | Bayer Inc. | Hydrogenated nitrile rubber composites with improved processability |
| US7105606B2 (en) | 2002-10-17 | 2006-09-12 | Lanxess Inc. | Polymer blends comprising low molecular weight nitrile rubber |
| US7595361B2 (en) | 2002-12-05 | 2009-09-29 | Lanxess Inc. | Adhesive compositions |
| US9346908B1 (en) | 2014-12-25 | 2016-05-24 | Industrial Technology Research Institute | Olefin-metathesis catalysts and method for preparing low-molecular-weight nitrile butadiene rubber |
-
2001
- 2001-06-29 CA CA 2351961 patent/CA2351961A1/en not_active Abandoned
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004035670A1 (en) | 2002-10-17 | 2004-04-29 | Bayer Inc. | Polymer composites comprising low molecular weight nitrile rubber |
| WO2004035669A1 (en) | 2002-10-17 | 2004-04-29 | Bayer Inc. | Hydrogenated nitrile rubber composites with improved processability |
| US7105606B2 (en) | 2002-10-17 | 2006-09-12 | Lanxess Inc. | Polymer blends comprising low molecular weight nitrile rubber |
| US7235601B2 (en) | 2002-10-17 | 2007-06-26 | Lanxess Inc. | Hydrogenated nitrile rubber compositions with improved processability |
| US7262244B2 (en) | 2002-10-17 | 2007-08-28 | Lanxess Inc. | Polymer composites comprising low molecular weight nitrile rubber |
| US7595361B2 (en) | 2002-12-05 | 2009-09-29 | Lanxess Inc. | Adhesive compositions |
| US9346908B1 (en) | 2014-12-25 | 2016-05-24 | Industrial Technology Research Institute | Olefin-metathesis catalysts and method for preparing low-molecular-weight nitrile butadiene rubber |
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