U.S. patent application number 11/848479 was filed with the patent office on 2007-12-20 for initiation of polymerization by hydrogen atom donation.
This patent application is currently assigned to E. I. duPont de Nemours and Company. Invention is credited to Alexei A. Gridnev, Steven Dale Ittel.
Application Number | 20070293595 11/848479 |
Document ID | / |
Family ID | 34962676 |
Filed Date | 2007-12-20 |
United States Patent
Application |
20070293595 |
Kind Code |
A1 |
Gridnev; Alexei A. ; et
al. |
December 20, 2007 |
INITIATION OF POLYMERIZATION BY HYDROGEN ATOM DONATION
Abstract
This invention relates to the polymerization of
vinylically-unsaturated monomers in the presence of a chain
transfer catalysts where the polymerization process is initiated
with hydrogen gas or a hydrogen atom donor rather than conventional
free radical initiators. This invention further relates to an
improved process for the polymerization of vinylically-unsaturated
monomers in the presence of a chain transfer catalysts where the
polymerization process is initiated with hydrogen gas.
Inventors: |
Gridnev; Alexei A.;
(Wilmington, DE) ; Ittel; Steven Dale;
(Wilmington, DE) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY;LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1128
4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Assignee: |
E. I. duPont de Nemours and
Company
Wilmington
DE
|
Family ID: |
34962676 |
Appl. No.: |
11/848479 |
Filed: |
August 31, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11330014 |
Jan 10, 2006 |
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11848479 |
Aug 31, 2007 |
|
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10802024 |
Mar 16, 2004 |
7022792 |
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11330014 |
Jan 10, 2006 |
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Current U.S.
Class: |
521/123 ;
526/90 |
Current CPC
Class: |
C08F 4/40 20130101; C08F
120/18 20130101; C08F 2/06 20130101; C08F 2/38 20130101; C08F
112/08 20130101; C08F 112/08 20130101; C08F 4/00 20130101; C08F
2/38 20130101; C08F 20/14 20130101; C08F 2/38 20130101; C08F 20/18
20130101; C08F 20/14 20130101; C08F 20/18 20130101; C08F 120/14
20130101 |
Class at
Publication: |
521/123 ;
526/090 |
International
Class: |
C08F 4/00 20060101
C08F004/00; C08G 18/08 20060101 C08G018/08 |
Claims
1-23. (canceled)
24. A polymer made by a process comprising: providing one or more
vinylinically-unsaturated monomers; contacting the one or more
vinylinically unsaturated monomers with a cobalt chain transfer
catalyst and hydrogen gas in the absence of conventional free
radical initiators, at a temperature of from room temperature to
about 240.degree. C., in the presence of an electron donor,
optionally in the presence of a solvent.
25. The polymer of claim 24 wherein the electron donor is selected
from amines, nitrogen heterocycles, and phosphorous donor
ligands.
26. The polymer of claim 25 wherein the nitrogen heterocycle is
imidazole, pyrrole, pyrimidine, or benzpyrazole.
27. A product containing a polymer of claim 24, said product
selected from: architectural coatings; aqueous and solvent-based
finishes; high-build maintenance finishes; paints; printing inks;
multilayer coatings; varnishes; crosslinking agents; defoamers;
deaeraters; wetting agents; substrate wetting additives; surface
control additives; reactive surface control additives; hydrophobing
agents; antigraffiti agents; nucleating agents; personal care
products; masks for screen printing; dental filling materials;
adhesives; lubricants; oil drilling fluids; adhesion promoters;
coupling agents; dispersants; grinding agents; solder masks;
tackifiers; leveling agents; artificial stone and marble; impact
modifiers; compatibilizers; plasticizers; caulks; sealants; drug
delivery agents; electronic materials; processing aids;
antistatics; softeners; antioxidants; UV stabilizers; dispersion
media; release agents; ion exchange resins or membranes; molded
objects; extruded objects; chain transfer reagents;
photopolymerizable materials; and etch resists and permanent
resists for printed electronic circuits.
28. A product comprising a hydroxyl-functionalized polymer made by
the process of claim 24, said product selected from rigid
polyurethanes, polyurethane foams, polyurethane adhesives and
polyurethane finishes.
Description
PRIORITY
[0001] This application is a Division of U.S. application Ser. No.
11/330,014, filed 2006-01-10, now pending, which is a Division of
U.S. application Ser. No. 10/802,024, filed 2004 Mar. 16, now U.S.
Pat. No. 7,022,792, issued 2006 Apr. 4, the disclosures of each of
which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to the initiation of polymerization
of one or more vinylically-unsaturated monomers using hydrogen atom
donors in the presence of chain transfer catalysts. This invention
further relates to the improved initiation of polymerization of
vinylically-unsaturated monomers using hydrogen gas in the presence
of chain transfer catalysts.
TECHNICAL BACKGROUND
[0003] It is known to use various cobalt complexes (e.g.,
cobaloximes or cobalt porphyrins) as chain transfer catalysts (CTC)
to provide oligomers or macromonomers bearing terminal double bonds
for use in polymeric products. See commonly owned U.S. Pat. Nos.
5,310,807, 5,362,813, 5,412,039, 5,502,113, and 5,587,431 and WO
9525765. All of the polymerizations were initiated with azo
initiators commonly employed in the acrylics industry and none of
the polymerizations were initiated with hydrogen gas or hydrogen
atom donors as described herein.
[0004] The use of chain transfer catalysts to control the molecular
weight of oligomers and polymers is known. U.S. Pat. Nos.
5,602,220, 5,770,665 and 5,684,101 as well as WO 9613527 disclose
this control, but do not teach initiation with hydrogen gas or
hydrogen atom donors. Commonly owned U.S. Pat. No. 5,726,263, and
application Ser. Nos. 08/818,860, 09/193,701 and 08/912,593 also
disclose this control, but again, disclose only conventional
initiation of polymerization.
[0005] The use of chain transfer catalysts in the presence of
hydrogen gas to initiate oligomerization and polymerization is
disclosed in commonly owned U.S. Pat. No. 4,680,352, but that
patent does not teach initiation by hydrogen atom donors. In the
disclosure of initiation in the presence of hydrogen gas, the
patent cites the use of cobalt complexes with planar macrocyclic
rings and particularly bisglyoximato ligands, but does not disclose
that certain hydrogen-atom bridged catalysts are far more
efficacious than others catalysts.
[0006] U.S. Pat. No. 5,306,856 discloses the synthesis of
alpha,omega-vinylically-unsaturated oligomers by the high
temperature, liquid phase reaction of alpha, omega-diolefin(s) in
the presence of aluminium hydrides. The process is not a free
radical process, but rather is a coordination polymerization and
chain transfer catalysts are not involved.
SUMMARY OF THE INVENTION
[0007] This invention relates to a process for polymerizing one or
more vinylically-unsaturated monomers to products having controlled
molecular weight and end-group functionality, wherein the process
comprises contacting said monomers with hydrogen gas or a hydrogen
atom donor and a chain transfer catalyst; said process carried out
at a temperature from about room temperature to about 240.degree.
C., in the absence of a free radical initiator and optionally in
the presence of a solvent.
[0008] This invention further relates to the products of the
processes described and their use in selected applications.
DETAILS OF THE INVENTION
[0009] The oligomers, macromonomers and polymers made by the
inventive process are typically prepared in a polymerization
reaction by standard solution polymerization techniques, but may
also be prepared by emulsion, suspension or bulk polymerization
processes. A continuous (CSTR) polymerization process may also be
used. All ingredients may be present at the beginning of the
polymerization or the polymerization may be carried out with
continuous addition as in the starved-feed mode.
[0010] As used herein, the term polymer refers to a macromolecule
consisting of two or more repeat units of the monomer and
polymerization is the process whereby that macromolecule is
prepared. Polymer is construed to include both homopolymers from
polymerization of one type of monomer and copolymers resulting from
the polymerization of two or more types of monomers. Oligomer or
co-oligomer generally refers to macromolecules having a carbon
chain length of between 4 (dimer) and about 50 when the product is
to be used in a final end-use application without further
polymerization though the vinylically-unsaturated end group.
Macromonomer generally refers to a macromolecule having a carbon
chain length of between 4(dimer) and about 50 when the product is
to by utilized in a subsequent polymerization making use of the
single terminal vinylic unsaturation provided by this process and
contributes only a single monomeric unit to the subsequent
macromolecule. Polymers or copolymers having a carbon chain length
greater than about 50 are available from this process. The terms
macromonomer and oligomer can used to describe the same material
and are often used interchangeably in the trade. When suitably
functionalized with pendant reactive groups, both oligomers or
macromonomers can be used in many applications where there is
subsequent polymerization or crosslinking though those reactive
groups; thus in these applications they can be considered to be
polyfunctional materials, but not necessarily macromonomers in the
sense that they do not contribute a single monomer to a growing
polymer chain.
[0011] Other than in specific cases where dimer is the only product
produced, the product polymer is a distribution of molecular
weights as is usually observed in polymer chemistry.
[0012] In conventionally-initiated polymerizations, an initiator
that produces carbon-centered radicals, sufficiently mild not to
destroy the metal chelate chain transfer catalyst, is typically
also employed in preparing the polymers. These initiators are
typically azo compounds having the requisite solubility and
appropriate half life, including azocumene;
2,2'-azobis(2-methyl)-butanenitrile;
2,2'-azobis(isobutyronitrile)(AIBN); 4,4'-azobis(4-cyanovaleric
acid); and 2-(t-butylazo)-2-cyanopropane. In the oligomerizations
and polymerizations described herein, these conventional initiators
are not employed.
[0013] Vinylically-unsaturated monomers suitable for use in this
process and giving the often-desired terminal vinylic unsaturation
(described as Class I) include monomers such as methyl
methacrylate, ethyl methacrylate, propyl methacrylates (all
isomers), butyl methacrylates (all isomers), 2-ethylhexyl
methacrylate, isobornyl methacrylate, methacrylic acid, benzyl
methacrylate, phenyl methacrylate, cyclohexyl methacrylate,
2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate,
2-isocyanatoethyl methacrylate, methacrylonitrile, alpha-methyl
styrene and its phenyl-substituted analogs, trimethoxysilylpropyl
methacrylate, triethoxysilylpropyl methacrylate,
tributoxysilylpropyl methacrylate, dimethoxymethylsilylpropyl
methacrylate, diethoxymethylsilylpropyl methacrylate,
dibutoxymethylsilylpropyl methacrylate,
diisopropoxymethylsilylpropyl methacrylate, dimethoxysilylpropyl
methacrylate, diethoxysilylpropyl methacrylate, dibutoxysilylpropyl
methacrylate, diisopropoxysilylpropyl methacrylate, glycidyl
methacrylate. Also suitable are isopropenyl butyrate, isopropenyl
acetate, isopropenyl benzoate, isopropenyl chloride, isopropenyl
fluoride, isopropenyl bromideitaconic, aciditaconic anhydride,
dimethyl itaconate, methyl itaconate, N-tert-butyl methacrylamide,
N-n-butyl methacrylamide, N-methylol methacrylamide, N-ethylol
methacrylamide, isopropenylbenzoic acids (all isomers),
diethylamino .alpha.-methylstyrenes (all isomers),
methyl-.alpha.-methylstyrenes (all isomers), isopropenylbenzene
sulfonic acids (all isomers), methyl 2-hydroxymethacrylate, ethyl
2-hydroxymethylacrylate, propyl 2-hydroxymethylacrylates (all
isomers), butyl 2-hydroxymethylacrylates (all isomers),
2-ethylhexyl 2-hydroxymethylacrylate, isobornyl
2-hydroxymethylacrylate, methyl 2-chloromethylacrylate, ethyl
2-chloromethylacrylate, propyl 2-chloromethylacrylates (all
isomers), butyl 2-chloromethylacrylates (all isomers), 2-ethylhexyl
2-chloromethylacrylate, isobornyl 2-chloromethylacrylate,
chloroprene, 2-phenylallylalcohol and substituted
2-phenylallylalcohols, N-isopropenylpyrrolidinone,
3-isopropenyl-.alpha..alpha.-dimethyl isocyanate,
isopropenylanilines, isopropenyl chloroformate, 2-aminoethyl
methacrylate hydrochloride, 2-methacryloxyethyl phosphoryl choline,
glycerol monomethyl methacrylate,
3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-D-glucofuranose,
.alpha.-methylene-.gamma.-butyrolactone and substituted
.alpha.-methylene-.gamma.-butyrolactones.
[0014] Equally effective are di- and polyfunctional
vinylically-unsaturated monomers, though they will lead to
crosslinking at higher conversions. They give the often-desired
terminal vinylic unsaturation and are thus also included in Class
I. Such monomers include ethanediol dimethacrylate, 1,2-propanediol
dimethacrylate, 1,3-propanediol dimethacrylate, butanediol
dimethacrylate (all isomers), hexanediol dimethacrylate (all
isomers), neopentylglycol dimethacrylate, cyclohexanediol
dimethacrylate (all isomers), cyclohexanedimethanol dimethacrylate
(all isomers), diethyleneglycol dimethacrylate, dipentaerythritol
monohydroxy pentamethacrylate, alkoxylated bisphenol-A
dimethacrylate (al isomers), ethanediol dimethacrylate, ethoxylated
trimethylolpropane trimethacrylate, glycerylpropoxy
trimethacrylate, pentaerythritol tetramethacrylate, pentaerythritol
trimethacrylate, polyethyleneglycol dimethacrylate,
diisopropenylbenzenes (all isomers), diisopropenyl adipate,
diisopropenyl maleate, and diisopropenyl terephthalate.
[0015] Certain additional monomers do not give the often-desired
terminal vinylic unsaturation in the final product when used in
homopolymerizations, but the initiation processes described herein
remain effective. When these monomers are employed in
copolymerizations with the above Class I monomers the often-desired
terminal vinylic unsaturation is usually obtained. These monomers
are described as Class II monomers, and include methyl acrylate,
ethyl acrylate, propyl acrylate (all isomers), butyl acrylates (all
isomers), 2-ethylhexyl acrylate, isobornyl acrylate, acrylic acid,
benzyl acrylate, phenyl acrylate, acrylonitrile, glycidyl acrylate,
2-hydroxyethyl acrylate, hydroxypropyl acrylates (all isomers),
hydroxybutyl acrylates (all isomers), diethylaminoethyl acrylate,
tri-ethyleneglycol acrylate, N-tert-butyl acrylamide, N-n-butyl
acrylamide, N-methyl-ol acrylamide, N-ethyl-ol acrylamide,
N,N-dimethylacrylamide, trimethoxysilylpropyl acrylate,
triethoxysilylpropyl acrylate, tributoxysilylpropyl acrylate,
dimethoxymethylsilylpropyl acrylate, diethoxymethylsilylpropyl
acrylate, dibutoxymethylsilylpropyl acrylate,
diisopropoxymethylsilylpropyl acrylate, dimethoxysilylpropyl
acrylate, diethoxysilylpropyl acrylate, dibutoxysilylpropyl
acrylate, diisopropoxysilylpropyl acrylate, vinyl acetate, vinyl
propionate, vinyl butyrate, vinyl benzoate, vinyl chloride, vinyl
fluoride, vinyl bromide, N-vinylpyrrolidinone, and styrenes. By
styrenes is meant unsubstituted styrene and all substituted
styrenes where the substitution is on the aromatic ring--for
instance, o-, m- and p-diethylaminostyrenes, o-, m- and
p-methylstyrenes, o-, m- and p-vinylbenzene sulfonic acids, o-, m-
and p-vinylbenzoic acids and their esters, and the many
polysubstituted combinations thereof.
[0016] In addition to the monofunctional monomers, certain bi- or
poly-functional Class II monomers are effective. They include
monomers such as ethanediol diacrylate, 1,2-propanediol diacrylate,
1,3-propanediol diacrylate, butanediol diacrylate (all isomers),
hexanediol diacrylate (all isomers), neopentylglycol diacrylate,
cyclohexanediol diacrylate (all isomers), cyclohexanedimethanol
diacrylate (all isomers), diethyleneglycol diacrylate,
dipentaerythritol monohydroxy pentaacrylate, alkoxylated
bisphenol-A diacrylate (all isomers), ethanediol diacrylate,
ethoxylated trimethylolpropane triacrylate, glycerylpropoxy
triacrylate, pentaerythritol tetraacrylate, pentaerythritol
triacrylate, polyethyleneglycol diacrylate, divinylbenzenes (all
isomers), divinyl adipate, divinyl maleate, and divinyl
terephthalate, divinyldimethylsilane, divinyldiphenylsilane,
divinyldimethoxysilane,
1,3-divinyl-1,3-dimethyl-1,3-dimethoxydisiloxane,
1,3-divinyl-1,1,3,3-tetramethyl-1,3-disiloxane, tetravinylsilane,
tetravinyldimethylsilane, diallyldimethylsilane,
diallyldiphenylsilane, diallyldimethoxysilane, and o-, m- and
p-divinylbenzenes.
[0017] Particularly suitable metallic chain transfer catalysts are
cobalt (II) and cobalt (III) chelates, also know as cobalt chain
transfer catalysts or CCT catalysts. Examples of such cobalt
compounds are disclosed in U.S. Pat. No. 4,680,352, U.S. Pat. No.
4,694,054, U.S. Pat. No. 5,324,879, WO87/03605 published Jun. 18,
1987, U.S. Pat. No. 5,362,826, and U.S. Pat. No. 5,264,530. Other
useful cobalt compounds (cobalt complexes of porphyrins,
phthalocyanines, tetraazoporphyrins, and cobaloximes) are
respectively disclosed in Enikolopov, N. S., et al., USSR Patent
664,434 (1978); Golikov, I., et al., USSR Patent 856,096 (1979);
Belgovskii, I. M., USSR Patent 871,378 (1979); and Belgovskii, I.
M., et al., USSR Patent 1,306,085 (1986). Suitable catalysts are
also disclosed in Gridnev and Ittel, Chemical Reviews, 101 (12),
3611 (2001).
[0018] US Patent Publication 2003149275 by DuPont discloses an
improved preparation of certain alkylcobalt(III)dioximate complexes
by the reaction of cobalt(II) salts, the dioxime ligands, an olefin
and a Lewis base in the presence of molecular hydrogen. The cobalt
complexes disclosed in that application are useful for the
polymerization processes described herein and are incorporated by
reference.
[0019] This process is not limited to the use of cobalt chain
transfer catalysts. In addition to the cobalt chain transfer
catalysts, catalysts based upon carbonyl chromium cyclopentadienyls
(Tang, Papish, Abramo, Norton, Baik, Friesner, and Rappe, Journal
of the American Chemical Society (2003), 125(33), 10093-10102) and
iron diimines (Gibson, O'Reilly, Wass, White, and Williams,
Macromolecules (2003), 36(8), 2591-2593) may be employed in this
invention.
[0020] These cobalt, chromium or iron catalysts operate at close to
diffusion-controlled rates and are effective at part-per-million
concentrations. Specific examples of these glyoximato-based cobalt
(II) and cobalt (III) chain transfer catalysts include, but are not
limited to those represented by the following structures:
##STR1##
[0021] Co(II)(DPG-BF.sub.2).sub.2, where J=K=Ph, Q=L=ligand,
Z=BF.sub.2
[0022] Co(II)(DMG-BF.sub.2).sub.2, where J=K=Me, Q=L=ligand,
Z=BF.sub.2
[0023] Co(II)(EMG-BF.sub.2).sub.2, where J=Me, K=Et, Q=L=ligand,
Z=BF.sub.2
[0024] Co(II)(DEG-BF.sub.2).sub.2, where J=K=Et, Q=L=ligand,
Z=BF.sub.2
[0025] Co(II)(CHG-BF.sub.2).sub.2, where J=K=--(CH.sub.2).sub.4--,
Q=L=ligand, Z=BF.sub.2
[0026] Co(II)(DMG-BF.sub.2).sub.2, where J=K=Me, Q=L=ligand,
Z=BF.sub.2
[0027] Co(II)(DPG-H).sub.2, where J=K=Ph, Q=L, L=ligand, Z=H
[0028] Co(II)(DMG-H).sub.2, where J=K=Me, Q=L, L=ligand, Z=H
[0029] Co(II)(EMG-H).sub.2, where J=Me, K=Et, Q=L, L=ligand,
Z=H
[0030] Co(II)(DEG-H).sub.2, where J=K=Et, Q=L, L=ligand, Z=H
[0031] Co(II)(CHG-H).sub.2, where J=K=--(CH.sub.2).sub.4--, Q=L,
L=ligand, Z=H
[0032] Co(II)(DMG-H).sub.2, where J=K=Me, Q=L, L=ligand, Z=H
[0033] QCo(III)(DPG-BF.sub.2).sub.2, where J=K=Ph, Q=alkyl,
L=ligand, Z=BF.sub.2
[0034] QCo(III)(DMG-BF.sub.2).sub.2, where J=K=Me, Q=alkyl,
L=ligand, Z=BF.sub.2
[0035] QCo(III)(EMG-BF.sub.2).sub.2, where J=Me, K=Et, Q=alkyl,
L=ligand, Z=BF.sub.2
[0036] QCo(III)(DEG-BF.sub.2).sub.2, where J=K=Et, Q=alkyl,
L=ligand, Z=BF.sub.2
[0037] QCo(III)(CHG-BF.sub.2).sub.2, where
J=K=--(CH.sub.2).sub.4--, Q=alkyl, L=ligand, Z=BF.sub.2
[0038] QCo(III)(DMG-BF.sub.2).sub.2, where J=K=Me, Q=halogen,
L=ligand, Z=BF.sub.2
[0039] QCo(III)(DPG-H).sub.2, where J=K=Ph, Q=alkyl, L=ligand,
Z=H
[0040] QCo(III)(DMG-H).sub.2, where J=K=Me, Q=alkyl, L=ligand,
Z=H
[0041] QCo(III)(EMG-H).sub.2, where J=Me, K=Et, Q=alkyl, L=ligand,
Z=H
[0042] QCo(III)(DEG-H).sub.2, where J=K=Et, Q=alkyl, L=ligand,
Z=H
[0043] QCo(III)(CHG-H).sub.2, where J=K=--(CH.sub.2).sub.4--,
Q=alkyl, L=ligand, Z=H
[0044] QCo(III)(DMG-H).sub.2, where J=K=Me, Q=halogen, L=ligand,
Z=H
[0045] In the above specific examples, DMG is dimethylglyoxime
based upon 2,3-butanedione, DEG is its ethyl analog based upon
3,4-hexanedione, EMG is the ethyl,methyl analog based upon
2,3-pentanedione, CHG is based upon 1,2-cyclohexanedione and DPG or
diphenylglyoxime ligands are based upon bibenzoyl.
[0046] Axial ligands, L, can be a variety of additional neutral
ligands commonly known in coordination chemistry. Examples include
water, amines, ammonia, nitrogen heterocycles, and phosphines. In
one exemplification of this invention, the axial ligands promote
the initiation reaction and are referred to specifically as
electron donors. Electron donors include amines; nitrogen
heterocycles such as pyridines, imidazole, pyrrole, pyrimidine,
benzpyrazole; and phosphorus ligands such as phosphines or
phosphites.
[0047] Q is an organic radical (e.g., alkyl or substituted alkyl).
Especially suitable Q groups are isopropyl, 1-cyanoethyl, and
1-carbomethoxyethyl. When Q is present, the cobalt center is
formally Co(III). When Q is a ligand, L, the cobalt center is
formally Co(II). When J and K are not the same, it is not intended
to designate their relative positions around the coordination
plane. The two glyoximato ligands are typically bridged. The most
common bridges are a proton and BF.sub.2, but may also include a
variety of other species including dialkyl or diarylborate,
BCl.sub.2, and other species that are formally monocationic until
ligated into the complex.
[0048] The chain transfer catalyst herein designated CoBF.sub.2
represents the family of chemicals defined by Z=BF.sub.2, or
bis-[(1,2-diR*-ethanedioximato)(2-)O:O'-tetrafluorodiborato(2-)-N'N''N'''-
N''''](Q)(L)cobalt(III), where R* is alkyl, aryl or substituted
aryl, Q is an alkyl or substituted alkyl ligand or an acido ligand
(e.g., chloro, bromo), and L is a Lewis base such as water,
pyridine, imidazole, other nitrogen heterocycles, phosphine, as
well as their derivatives. It is preferred that R* is methyl, Q is
isopropyl and L is water, which represents one of the catalysts
most frequently used in this study. This is referred to as Cat-1,
shown below. The other primary catalyst used in this study has a
hydrogen atom bridge rather than a BF.sub.2 bridge; L is pyridine;
Q is methoxyethylpropionate; and R* is methyl. This is referred to
as Cat-2, shown below. ##STR2##
[0049] The catalysts can also include cobalt complexes of a variety
of porphyrin molecules such as tetraphenylporphyrin,
tetraanisylporphyrin, tetramesitylporphyrin and other substituted
porphyrin species.
[0050] The very specific planer, macrocyclic structures of the
cobalt catalysts allows molecular weight (MW) to be effectively
controlled. It is also important that these reactions lead to
formation of polymers and oligomers with a terminal double bond
(strictly one bond per polymer molecule, more than 95%) as found in
Davis, Haddleton, and Richards, Rev. Macromol. Chem. Phys., C34
(1994) 243. This allows the products to be used as macromonomers
for subsequent copolymerizations. The polymerization process,
employing the above described metallic chain transfer catalysts, is
carried out suitably at a temperature ranging from about room
temperature to about 240.degree. C. or higher, preferably about
50.degree. C. to 150.degree. C. The polymers made by the inventive
process are typically prepared in a polymerization reaction by
standard solution polymerization techniques, but may also be
prepared by emulsion, suspension or bulk polymerization processes.
The polymerization process can be carried out as either a batch, a
semi-batch, or a continuous (CSTR) process. When carried out as a
batch process, the reactor is typically charged with metal chain
transfer catalyst, a monomer, optionally with a solvent. Normally
at this point, the desired amount of initiator is added to the
mixture, typically such that the monomer-to-initiator ratio is 5 to
1000. However, in the current invention, no initiator is added.
Rather, the mixture is exposed to hydrogen gas or a hydrogen atom
donor molecule. The mixture is then heated for the requisite time,
usually from about 30 minutes to about 12 hours. In a batch
semibatch or continuous process, the reaction may be run under
pressure to avoid monomer reflux.
[0051] A hydrogen atom donor molecule, D-H, is a molecule capable
of readily donating a hydrogen atom to the metal center of the
chain transfer catalyst. In the present invention it is preferred
that D-H represents a hydrogen donor wherein the corresponding
organic radical D. has a stability which is at least several
hundred times greater than that of a primary alkyl radical (e.g.,
ethyl radical) and less than 6000 times that of a primary alkyl
radical. The method of determining this stability (or reactivity)
is well known in the art (Radicals Vol. 1, Jay K. Kochi, John Wiley
and Sons, 1973, N.Y., N.Y., pp. 302-03). The stability measured is
the stability of the radical D. (i.e., the radical resulting from
removal of H. from D-H) as compared to the stability or reactivity
of a primary alkyl radical.
[0052] Hydrogen atom donor compounds include such diverse chemical
classes of materials as stananes, silanes, benzhydrols,
diarylphosphines, triarylmethanes, N,.omega.-dialkylpiperizines,
3-pyrrolines, xanthenes, 9,10-dihydroanthracenes,
9-hydroxyfluorenes, aryl-.beta.-ketoesters, aldehydes, benzylic
alcohols, alkyl-.beta.-ketoesters, oximes (such as acetophenone
oxime and benzaldehyde oxime), and amidoximes (such as caprolactam
oxime). Specific examples of hydrogen atom donors include but are
not limited to the following reagents: tributyltin hydride,
triethylsilane, benzhydrol, triphenylmethane,
N,N'-dimethylpiperazine, xanthene, 9,10-dihydroanthracene,
1,2-dihydronaphthalene, 9-hydroxyfluorene, pivaldehyde, ethyl
benzoylacetate, or ethyl isobuterylacetate. Molecules such as
3-pyrroline or diphenylphosphine can serve as hydrogen atom donors,
but the ability of the nitrogen or phosphorus atom to coordinate to
the cobalt or other metal center must be taken into
consideration.
[0053] As indicated above, the polymerization can be carried out in
the absence of, or in the presence of, any medium or solvent
suitable for free-radical polymerization, including, but not
limited to, ketones such as acetone, butanone, pentanone and
hexanone; alcohols such as isopropanol; amides such as dimethyl
formamide; aromatic hydrocarbons such as toluene and xylene; ethers
such as tetrahydrofuran and diethyl ether; ethylene glycol; glycol
ethers, alkyl esters or mixed ester ethers such as monoalkyl
ether-monoalkanoates; and mixtures of two or more solvents.
[0054] U.S. Pat. No. 5,726,263 to DuPont describes a method by
which macromonomers formed by chain transfer catalysis
polymerization methods may be decolorized by selective extraction
and/or adsorption. The process involves a process of selection of
polarities of the monomers, solvent and catalyst to optimize the
catalyst residue removal process. The dimers, trimers and oligomers
formed during the polymerization reaction have a very low optical
density. U.S. Pat. No. 5,750,772 to DuPont describes a process
whereby hydroxy-containing methacrylate homo- and copolymers are
decolorized by the addition of a strong acid and a chelating,
bidentate nitrogen ligand with subsequent purification through a
polar adsorption medium. In the processes described herein, it is
often desirable to utilize relatively high concentrations of chain
transfer catalyst, so the product decolorization processes
described above could be of particular importance.
[0055] The oligomers, polymers and/or copolymers prepared according
to the present invention can be employed, not only as non-metallic
chain transfer agents, but as useful components and intermediates
in the production of graft copolymers, non-aqueous dispersed
polymers, block copolymers, microgels, star polymers, branched
polymers, structured polymers and ladder polymers.
[0056] The products of the processes described herein find use in
the production of architectural coatings; automotive finishes,
including high solids, aqueous and solvent-based finishes;
high-build maintenance finishes and other paints; printing inks
including ink jet inks and UV/EB curable inks; multilayer coatings;
varnishes; crosslinking agents; defoamers; deaeraters; wetting
agents; substrate wetting additives; surface control additives;
reactive surface control additives; hydrophobing agents;
antigraffiti agents; nucleating agents; personal care products;
masks for screen printing; dental filling materials; adhesives;
lubricants; oil drilling fluids; adhesion promoters; coupling
agents; dispersants (e.g., for pigments); grinding agents; solder
masks; tackifiers; leveling agents; artificial stone and marble;
impact modifiers; compatibilizers; plasticizers; caulks; sealants;
drug delivery agents; electronic materials; processing aids;
antistatics; softeners; antioxidants; UV stabilizers; dispersion
media; release agents; ion exchange resins or membranes; molded
objects; extruded objects; chain transfer reagents;
photopolymerizable materials; and etch or permanent resists for
printed electronic circuits. When hydroxyl-functionalized, they may
be employed in rigid polyurethanes, polyurethane foams,
polyurethane adhesives and polyurethane finishes.
EXAMPLES
[0057] .sup.1H-NMR spectra were taken on a QE300 NMR spectrometer
(General Electric Co., Freemont, Calif. 94539) at 300 MHz
frequency.
[0058] K.sup.+IDS mass spectroscopy is an ionization method that
produces pseudomolecular ions in the form of [M]K.sup.+ with little
or no fragmentation. Intact organic molecules are desorbed by rapid
heating. In the gas phase the organic molecules are ionized by
potassium attachment. Potassium ions are generated from an
aluminosilicate matrix that contains K.sub.2O. All of these
experiments were performed on a Finnegan Model 4615 GC/MS
quadrupole mass spectrometer (Finnegan MAT (USA), San Jose,
Calif.). An electron impact source configuration operating at
200.degree. C. and a source pressure of <1.times.10.sup.-6 torr
was used.
[0059] Matrix-Assisted Laser Desorption/Ionization (MALDI) mass
spectra were obtained on an Applied Biosystems Voyager DE-STR MALDI
mass spectrometer. Samples were prepared by co-crystallizing the
analyte solution with a UV-absorbing matrix (2,5-dihydroxybenzoic
acid) onto a stainless steel target plate which was introduced to
the mass spectrometer under high vacuum (about 2e-7 torr).
Irradiation with a nitrogen laser at 337 nm was used to transfer
the analyte to the gas phase, where Na.sup.+ or K.sup.+ cations
ionized the molecules. A voltage of 20 kV was applied to accelerate
the ions to determine their mass by time of flight.
[0060] The size exclusion chromatography method used to measure the
molecular weight distribution in these systems utilized an Alliance
2690 from Waters Corporation (Milford, Mass.), with a Waters 410
refractive index detector (DRI). The software for data reduction
was Trisec.RTM. Conventional GPC version 3.0 by Viscotek. The
columns were two PL Gel Mixed C and one PL Gel 500A columns from
Polymer Laboratories. The mobile phase was unstabilized THF.
Chromatographic conditions were 35.degree. C. at a flow rate of
1.00 ml/min, an injection volume of 100 .mu.l and a run time of 50
min. Samples were dissolved for 4 hours in the mobile phase solvent
at RT with moderate agitation. Standards for column calibration
were a set of 10 narrow polydispersity (<1.1) poly(methyl
methacrylate) (PMMA) standards with peak molecular weights from
1680 through 1,399,000 available from Polymer Laboratories. The
column calibration method with PMMA narrow standards utilized a
third order of polynomial fit.
[0061] All chemicals and reagents in the examples below were used
as received from Aldrich Chemical Co., Milwaukee, Wis. unless
otherwise indicated.
Examples
Example 1
Oligomerization of Butyl Methacrylate with Hydrogen Initiation
[0062] Reagent grade butyl methacrylate (19.5 mL), 60 mg of
pyridinato-bis(dimethylglyoximato)-Co(III)-(2-(butyl propionyl) and
10 ml of 1,2-dichloroethane were degassed by passing a stream of
nitrogen through the solution. Then the nitrogen was replaced with
one atmosphere (101 kPa) of molecular hydrogen and the temperature
was raised to 80.degree. C. with continuous stirring of the
reaction mixture. After 14 hours the reaction mixture was
evaporated and analyzed by GPC and NMR. The yield was 18 mL of a
mixture of butyl methacrylate dimer and trimer, indicating
successful oligomerization.
Comparative Example A
Control Experiment with No Hydrogen
[0063] The experiment was conducted as described in Example 1,
except the nitrogen flush was continued throughout the duration of
the polymerization and no hydrogen was admitted to the system.
After evaporation of the reaction solution less than 1% of
polymeric product was obtained. The oligomerization did not occur
in the absence of hydrogen.
Comparative Example B
Control Experiment with No Cobalt Chelate
[0064] The experiment was conducted as described in Example 1,
except the cobalt chelate
(pyridinato-bis(dimethylglyoximato)-Co(III)-(2-(butyl propionyl))
was not added. After evaporation of the reaction solution, less
than 0.2% of polymeric product was obtained. The oligomerization
did not occur in the absence of chain transfer catalyst.
Example 2
Oligomerization of Alpha-Methylstyrene with Hydrogen Initiation
[0065] Reagent grade alpha-methyl styrene (30 mL), 8 mg of
pyridinato-bis(dimethylglyoximato)-Co(III)-(2-(butyl propionyl) and
5 ml of 1,2-dichloroethane were degassed by passing a stream of
nitrogen through the solution. Then nitrogen was replaced with one
atmosphere (101 kPa) of molecular hydrogen and the temperature was
raised to 90.degree. C. with continuous stirring of the reaction
mixture. After 8 hours the resulting product was evaporated and
analyzed by GPC and NMR. Approximately 28% of the starting material
had been converted to alpha-methyl styrene dimer. Thus, the process
is not limited to acrylates.
Example 3
Oligomerization of MMA with Hydrogen Initiation
[0066] A solution of (methoxyethylpropionyl)bis(dimethylglyoxime)
cobalt(III)--(150 mg Cat-2) in 250 ml MMA was deoxygenated for 20
min by passing molecular hydrogen gas through it. The temperature
was then raised to 85.degree. C. The conversions to oligomers are
shown in the Table.
Example 4
Oligomerization of MMA with Hydrogen Initiation
[0067] A solution of (2-propyl)bis(dimethylglyoximedifluoroborato)
cobalt(III)--(150 mg) in 250 ml MMA was deoxygenated for 20 min by
passing molecular hydrogen through it. The temperature was then
raised to 85.degree. C. The conversions to oligomers are shown in
the Table.
Example 5
Improvement with Addition of Imidazole
[0068] Example 3 was repeated with the addition of 3 mL of a
solution of 0.25% imidazole (Im) in MEK. The conversions to
oligomers are shown in the Table. Addition of a small portion of
imidazole dramatically increased the conversion.
Example 6
Further Addition of Imidazole
[0069] Example 3 was repeated with 3 ml solution of 0.5% imidazole
(Im) in MEK. The conversions to oligomers are shown in the Table.
Further addition of imidazole continued to increase the conversion.
TABLE-US-00001 TABLE Example Number 3 4 5 6 Catalyst Cat-2 Cat-1
Cat-1/lm Cat-1/lm Time (hr) Yield (%) 0.5 88 45 0.75 65 75 2 97 53
77 87 4 98 60 5 85 92 6 99
[0070] As can be seen in the Table above, a catalyst with a
hydrogen atom bridge (Cat-2) is more effective than a catalyst with
a BF.sub.2 bridge (Cat-1). Nonetheless, addition of bases such as
imidazole have the ability to increase the effectiveness of the
BF.sub.2-bridged catalysts.
Example 7
Oligomerization with Less Catalyst
[0071] Example 1 was repeated utilizing less catalyst. Conversions
as a function of time were lower, and the molecular weights of the
macronomomers isolated were higher. Thus, the reaction can be
carried out with less chain transfer catalyst and the molecular
weight of the product increases as expected.
Example 8
Oligomerization of Methyl Methacrylate with Hydrogen Gas Initiation
and Demonstration of Terminal Unsaturation
[0072] Alumina purified methyl methacrylate (13.2 mL, 0.12 mol),
cobalt(II) [bis[m-[(2,3-butanedione
dioximato)(2-)-O:O']]tetrafluorodiborato(2-)-N,N',N'',N''']isopropyl
aquo complex, 60 mg, 0.13 mmol) and methyl ethyl ketone (10 mL)
were degassed via bubbling hydrogen gas through the brown solution
for 20 min. The solution was heated to 80.degree. C. under minimal
hydrogen pressure while stirring for ca. 4 h. The cooled solution
was concentrated under reduced pressure leaving a suspension (3.81
g, 31% conversion). ESI and MALDI (Na.sup.+ cationization) data
show vinylically-unsaturated MMA dimer up to the 12-mer, but
centered around trimer. In the low molecular weight GPC analysis,
peaks for dimer, trimer and tetramer were clearly visible with a
slight shoulder for pentamer.
Example 9
Oligomerization of Methyl Methacrylate Initiating with
1,2-Dihydronaphthalene
[0073] Alumina purified methyl methacrylate (13.2 mL, 0.12 mol),
cobalt(II) [bis[m-[(2,3-butanedione
dioximato)(2-)-O:O']]tetrafluorodiborato(2-)-N,N',N'',N''']isopropyl
aquo complex, 60 mg, 0.13 mmol), 1,2-dihydronaphthalene (0.5 mL,
3.8 mmol), and methyl ethyl ketone (10 mL) were degassed via
bubbling nitrogen gas through the brown solution for 20 min. The
solution was heated to 80.degree. C. under minimal nitrogen
pressure while stirring for ca. 4 h. The cooled solution was
concentrated under reduced pressure leaving a fine suspension (1.56
g, 13% conversion). ESI and MALDI (Na.sup.+ cationization) data
show vinylically-unsaturated MMA dimer up to 19-mer but primarily
dimer and trimer. In the low molecular weight GPC analysis, peaks
for dimer, trimer, tetramer and pentamer were clearly visible with
a slight shoulder for hexamer.
Example 10
Oligomerization of Methyl Methacrylate Initiating with
Triethylsilane
[0074] Alumina purified methyl methacrylate (13.2 mL, 0.12
mol),cobalt(II) [bis[m-[(2,3-butanedione
dioximato)(2-)-O:O']]tetrafluorodiborato(2-)-N,N',N'',N''']isopropyl
aquo complex, 60 mg, 0.13 mmol), triethylsilane (0.5 mL, 3.1 mmol),
and methyl ethyl ketone (10 mL) were degassed via bubbling nitrogen
gas through the solution for 20 min. The solution was heated to
80.degree. C. under minimal nitrogen pressure while stirring for
ca. 4 h. The cooled solution was concentrated under reduced
pressure leaving a fine suspension (2.4 g, 19% conversion). MALDI
(Na.sup.+ cationization) data show vinylically-unsaturated MMA
oligomers up to 20-mer with the low oligomers dominating. The
spectra are complicated by the presence of peaks associated with
the tin compounds, but there appears to be no incorporation of tin
into the oligomers.
Example 11
Oligomerization of Methyl Methacrylate Initiating with Tributyltin
Hydride
[0075] Alumina purified methyl methacrylate (13.2 mL, 0.12 mol),
cobalt(II)[bis[m-[(2,3-butanedione
dioximato)(2-)-O:O']]tetrafluorodiborato(2-)-N,N',N'',N''']isopropyl
aquo complex, 60 mg, 0.13 mmol), tributyltin hydride (0.25 mL, 0.93
mmol), and methyl ethyl ketone (10 mL) were degassed via bubbling
nitrogen gas through the solution for 20 min. The solution was
heated to 80.degree. C. under minimal nitrogen pressure while
stirring for ca. 4 h. The cooled solution was concentrated under
reduced pressure leaving a suspension (950 mg, 8% conversion). ESI
and MALDI (Na.sup.+ cationization) data show
vinylically-unsaturated MMA dimer up to pentamer.
Example 12
Co-Oligomerization of Methyl Methacrylate and Butyl Acrylate Using
Hydrogen Gas Initiation
[0076] Alumina purified methyl methacrylate (13.2 mL, 0.12 mol),
alumina purified butyl acrylate (11.2 mL, 0.078 mol), cobalt(III)
[bis[m-[(2,3-butanedionedioximato)(2-)-O:O']]tetrafluorodiborato(2-)-N,N'-
,N'',N''']isopropyl aquo complex, 60 mg, 0.13 mmol) and methyl
ethyl ketone (10 mL) were degassed via bubbling hydrogen gas
through the solution for 20 min. The solution was heated to
80.degree. C. under minimal hydrogen pressure while stirring for
ca. 4 h. The cooled solution was concentrated under reduced
pressure leaving a suspension (4.98 g, 25% conversion). MALDI
(Na.sup.+ cationization) data show vinylically-unsaturated random
oligomers of methyl methacrylate with butyl acrylate up to MW 2063
corresponding to 15 MMA: 5 BA. There were undoubtedly higher
products not detected by this analytical method. The oligomers were
generally of the formula MMA.sub.(1-15)BA.sub.(0-5). Peaks that
could be associated with pure BA oligomers were observed, but at
very low intensities. Thus the product in the mixture generally had
at least one MMA, presumably as the terminally unsaturated
component.
Example 13
Oligomerization of Butyl Acrylate Using Hydrogen Gas Initiation
[0077] Alumina purified butyl acrylate (11.2 mL, 0.078 mol),
cobalt(II) [bis[m-[(2,3-butanedione
dioximato)(2-)-O:O']]tetrafluoro-diborato(2-)-N,N',N'',
N''']-isopropyl aquo complex, 60 mg, 0.13 mmol and methyl ethyl
ketone (10 mL) were degassed via bubbling hydrogen gas through the
solution for 20 min. The solution was heated to 80.degree. C. under
minimal hydrogen pressure while stirring for ca. 4 h. The cooled
solution was concentrated under reduced pressure leaving a viscous
liquid (4.5 g, 45% conversion). MALDI (Na.sup.+ cationization) data
suggest unsaturated BA oligomers and polymer up to 42-mer. Chain
transfer for the acrylate was not as efficient as in the presence
of some methacrylate, but hydrogen gas initiation was
successful.
Example 14
Oligomerization of Methyl Methacrylate Initiated with
Hydroquinone
[0078] Alumina purified methyl methacrylate (13.2 mL, 0.12 mol),
CCT catalyst (cobalt(II) [bis[m-[(2,3-butanedione
dioximato)(2-)-O:O']](2-)-N,N',N'',N''']pyridyl(methoxy ethyl
propionyl), 60 mg, 0.13 mmol), hydroquinone (440 mg, 4.0 mmol) and
methyl ethyl ketone (10 mL) were degassed via bubbling nitrogen gas
through the orange solution for 20 min. The solution was heated to
80.degree. C. under minimal nitrogen pressure while stirring for
ca. 4 h. The cooled solution was concentrated under reduced
pressure giving 2.04 g of oligomer or 17% conversion). MALDI
(Na.sup.+ cationization) data suggest vinylically-unsaturated MMA
trimer up to 45-mer.
[0079] Hydroquinone and its closely related product, the
monomethylether of hydroquinone (MEHQ), are often added to methyl
methacrylate as stabilizers against polymerization during handling
and storage. See, for example, an Aldrich catalog. However, the
present work example shows the successful use of these materials as
polymerization initiators.
Example 15
Oligomerization of Methyl Methacrylate Initiated with
Benzhydrol
[0080] Alumina purified methyl methacrylate (13.2 mL, 0.12 mol),
cobalt(II)[bis[m-[(2,3-butanedione
dioximato)(2-)-0:0']](2-)-N,N',N'',N''']pyridyl(methoxy ethyl
propionyl), 60 mg, 0.13 mmol), benzhydrol (737 mg, 4.0 mmol) and
methyl ethyl ketone (10 mL) were degassed by bubbling argon gas
through the orange solution for 20 min. The solution was heated to
80.degree. C. under minimal nitrogen pressure while stirring for
ca. 4 h. The cooled solution was concentrated under reduced
pressure giving 2.2 g of product or 18% conversion.
Comparative Example C
Azo-Derived Impurities in Polymerizations Initiated with
Conventional Azo Initiators
[0081] Alumina purified methyl methacrylate (12 g), CCT catalyst
((methoxyethyl propionyl)cobalt(III)[bis[(2,3-butanedione
dioximate)(2-)-0:0']] (60 mg), and azobis(isobutyronitrile), 600
mg) were heated at 80.degree. C. in MEK solvent (10 mL) for 4 h. By
nmr analysis, the resulting product was primarily the unsaturated
dimer of MMA with the next most abundant species being the
unsaturated MMA trimer. In the CN region, there was an impurity
peak associated with the symmetric vazo dimer that is known to be
toxic. In addition, there were many additional small peaks
associated with other cyanide-substituted, quaternary carbons
atoms. Several of the peak positions were very similar to those of
methacrylonitrile and isobutyronitrile. Finally, there were
additional peaks of nitrile-containing components that could
possibly be associated the incorporation of methacrylonitrile into
the oligomers. All of these nitrile-containing products can be
associated with the use of an azo initiator, its initial
cyanopropyl radical and the products from the cyanopropyl radical
after reacting with the cobalt chain transfer catalyst. The use of
hydrogen gas or hydrogen atom donors as initiators yields
nitrile-free products.
* * * * *