U.S. patent application number 15/787106 was filed with the patent office on 2018-02-08 for inhibitor combination for lithium salt-catalyzed transesterification process and method for removing lithium salt.
The applicant listed for this patent is Dow Global Technologies LLC, Rohm and Haas Company. Invention is credited to Christopher R. Eddy, Lan T.P. Hoang Nguyen, John O. Osby, Robert Wilczynski.
Application Number | 20180037531 15/787106 |
Document ID | / |
Family ID | 52021458 |
Filed Date | 2018-02-08 |
United States Patent
Application |
20180037531 |
Kind Code |
A1 |
Wilczynski; Robert ; et
al. |
February 8, 2018 |
Inhibitor Combination for Lithium Salt-Catalyzed
Transesterification Process and Method for Removing Lithium
Salt
Abstract
A process to form a composition comprising an asymmetrical
polyene, the asymmetrical polyene comprising an ".alpha.,.beta.
unsaturated-carbonyl end" and a "C--C double bond end," the process
comprising: reacting an alkene- or polyene-containing alcohol with
an alkyl ester of an .alpha.,.beta. unsaturated carboxylic acid in
the presence of at least the following components A) through C) to
form a solution comprising an asymmetrical polyene: A) a lithium
salt; B) a component selected from the group consisting of
hydroquinone, an alkyl-substituted phenol, a substituted
alkyl-substituted phenol, an alkyl-substituted hydroquinone, a
substituted alkyl-substituted hydroquinone, and combinations
thereof; and C) an N-oxyl-containing compound; wherein the
".alpha.,.beta. unsaturated-carbonyl end" of the asymmetrical
polyene is selected from the group consisting of structures a)
through c), as described herein, and wherein the "C--C double bond
end" of the asymmetrical polyene is selected from the group
consisting of structures 1) through 17), as described herein.
Inventors: |
Wilczynski; Robert;
(Yardley, PA) ; Eddy; Christopher R.; (Lake
Jackson, TX) ; Osby; John O.; (Lake Jackson, TX)
; Nguyen; Lan T.P. Hoang; (Doylestown, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dow Global Technologies LLC
Rohm and Haas Company |
Midland
Collegeville |
MI
PA |
US
US |
|
|
Family ID: |
52021458 |
Appl. No.: |
15/787106 |
Filed: |
October 18, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15100759 |
Jun 1, 2016 |
9796650 |
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PCT/US2014/066745 |
Nov 21, 2014 |
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15787106 |
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61920939 |
Dec 26, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08F 220/287 20200201;
C08F 2/38 20130101; C07C 69/587 20130101; C07C 67/02 20130101; C07C
67/03 20130101; C08F 210/02 20130101; C08F 220/1818 20200201; C08F
220/68 20130101; C08F 210/02 20130101; C08F 220/68 20130101; C08F
210/02 20130101; C08F 220/287 20200201; C08F 210/02 20130101; C08F
220/1818 20200201; C08F 210/02 20130101; C08F 220/287 20200201 |
International
Class: |
C07C 67/02 20060101
C07C067/02; C07C 69/587 20060101 C07C069/587; C08F 220/68 20060101
C08F220/68; C08F 2/38 20060101 C08F002/38; C08F 210/02 20060101
C08F210/02; C07C 67/03 20060101 C07C067/03 |
Claims
1. A composition comprising: A) an asymmetrical polyene with an
".alpha.,.beta. unsaturated-carbonyl end" and a "C--C double bond
end;" B) less than 100 ppm, based on the total weight of the
composition, of an inhibitor selected from the group consisting of
4-HT and derivatives thereof; and C) less than 2000 ppm, based on
the total weight of the composition, of MeHQ, wherein the
".alpha.,.beta. unsaturated-carbonyl end" of the asymmetrical
polyene is selected from the group consisting of the following:
##STR00026## wherein R.sub.1 is selected from H or a
C.sub.1-C.sub.6 alkyl; ##STR00027## wherein R.sub.2 is selected
from H or a C.sub.1-C.sub.6 alkyl; R.sub.3 is selected from H,
CH.sub.3, or CH.sub.2CH.sub.3; R.sub.4 is selected from H,
CH.sub.3, or CH.sub.2CH.sub.3; and n is from 1 to 50; and
##STR00028## and wherein the "C--C double bond end" of the
asymmetrical polyene is selected from the group consisting of the
following: ##STR00029## wherein R5 is selected from H or C1-C6
alkyl; ##STR00030## wherein R6 is selected from H or C1-C6 alkyl;
##STR00031## wherein R7 is selected from H or C1-C6 alkyl;
##STR00032## ##STR00033## wherein m=1 to 20.
2. The composition of claim 1 comprising from 25 ppm to less than
100 ppm, based on the weight of the composition, of the inhibitor
selected from the group consisting of 4-HT and derivatives
thereof.
3. The composition of claim 1 comprising from 50 ppm to less than
2000 ppm, based on the weight of the composition, of MeHQ.
4. The composition of claim 1 further comprising less than 10 wt %
unreacted alkene- or polyene-containing alcohol, based on the total
weight of the composition.
5. The composition of claim 4 comprising from 2 wt % to less than
10 wt % unreacted alkene- or polyene-containing alcohol, based on
the total weight of the composition, wherein the unreacted alkene-
or polyene-containing alcohol is polypropylene glycol allyl
ether.
6. The composition of claim 1 further comprising less than 10 wt %
of Michael adducts, based on the total weight of the
composition.
7. The composition of claim 1 further comprising a lithium
salt.
8. The composition of claim 7, wherein the lithium salt has the
structure Li.sub.nX, wherein n is 1 or 2; and X is selected from
the group consisting of hydroxide, oxide, halide, carbonate,
bicarbonate, alkoxide, alkonate, alkenoate, phenoxide, sulfate,
bisulfate, sulfonate, phosphate, phosphonate, perchlorate, and
nitrate.
9. The composition of claim 7, wherein the lithium salt has the
structure Li.sub.nX, wherein n is 1 or 2; and X is selected from
the group consisting of OH.sup.-, O.sup.-2, a halide, OR.sup.-,
CO.sub.3.sup.-2, HCO.sub.3.sup.-, and R'CO.sub.2.sup.-; wherein R
is selected from a C1-C8 straight chain or branched alkyl group or
from an aryl group; wherein R' is selected from either a C1-C8
straight chain or branched alkyl group, or an aryl group, or a
C1-C3 alkene group.
10. The composition of claim 7, wherein the lithium salt is
anhydrous lithium hydroxide.
11. The composition of claim 1 further comprising unreacted alkyl
ester of an .alpha.,.beta. unsaturated carboxylic acid.
12. The composition of claim 11, wherein the unreacted alkyl ester
of an .alpha.,.beta. unsaturated carboxylic acid is methyl
methacrylate.
13. An asymmetrical polyene formed by reacting an alkene- or
polyene-containing alcohol with an alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid in the presence of at least components
A) through C) to form a solution comprising the asymmetrical
polyene: A) a lithium salt, B) a component selected from the group
consisting of hydroquinone, an alkyl-substituted phenol, a
substituted alkyl-substituted phenol, an alkyl-substituted
hydroquinone, a substituted alkyl-substituted hydroquinone, and
combinations thereof, and C) an N-oxyl-containing compound, wherein
the asymmetrical polyene has an ".alpha.,.beta.
unsaturated-carbonyl end" selected from the group consisting of the
following: ##STR00034## wherein R.sub.1 is selected from H or a
C.sub.1-C.sub.6 alkyl; ##STR00035## wherein R.sub.2 is selected
from H or a C.sub.1-C.sub.6 alkyl; R.sub.3 is selected from H,
CH.sub.3, or CH.sub.2CH.sub.3; R.sub.4 is selected from H,
CH.sub.3, or CH.sub.2CH.sub.3; and n is from 1 to 50; and
##STR00036## and a "C--C double bond end" selected from the group
consisting of the following: ##STR00037## wherein R5 is selected
from H or C1-C6 alkyl; ##STR00038## wherein R6 is selected from H
or C1-C6 alkyl; ##STR00039## wherein R7 is selected from H or C1-C6
alkyl; ##STR00040## ##STR00041## wherein m=1 to 20.
14. The asymmetrical polyene of claim 13, wherein the asymmetrical
polyene is polypropylene glycol allyl ether methacrylate (PPG
AEMA).
Description
BACKGROUND OF THE INVENTION
[0001] Lithium hydroxide is a known transesterification catalyst
for making methacrylate ester monomers via reaction of methyl
methacrylate (MMA) with specialty alcohols (for example, see U.S.
Pat. No. 6,048,916, GB 1,094,998, U.S. Pat. No. 5,072,027, U.S.
Pat. No. 4,916,255, U.S. Pat. No. 4,672,105, JP 2007055910A).
Inhibitors are typically employed in these reactions to keep the
monomers from polymerizing during processing. Inhibitors often
include, among others, the methyl ether of hydroquinone (MeHQ)
and/or phenothiazine (PTZ).
[0002] There is continued interest in developing inhibitor
combinations which allow the transesterification process to proceed
at higher rates while maintaining excellent long term monomer
product stability.
[0003] When these transesterification reactions are complete, the
catalyst is often removed via filtration procedures that include
the addition of either some solid filtration agent (such as
diatomaceous earth; in addition to above references, also see
JP03109350A) or a hydrocarbon solvent (see JP3106847A) to aid in
precipitation and/or removal of the precipitated lithium salts.
These filtration agents and solvents, however, create more waste
and increase disposal costs.
[0004] There also remains a need for a process to remove the
lithium catalyst (i.e., lithium salt) without the addition of
filtration agents or solvents.
SUMMARY OF THE INVENTION
[0005] The invention provides a transesterification process to form
a composition comprising an asymmetrical polyene, the asymmetrical
polyene comprising an ".alpha.,.beta. unsaturated-carbonyl end" and
a "C--C double bond end," the process comprising reacting an
alkene- or polyene-containing alcohol with an alkyl ester of an
alpha, beta unsaturated carboxylic acid in the presence of at least
the following components A) through C), to form a solution
comprising the asymmetrical polyene: [0006] A) a lithium salt;
[0007] B) a component selected from the group consisting of
hydroquinone, an alkyl-substituted phenol, a substituted
alkyl-substituted phenol, an alkyl-substituted hydroquinone, a
substituted alkyl-substituted hydroquinone, and combinations
thereof; and [0008] C) an N-oxyl-containing compound; wherein the
".alpha.,.beta.0 unsaturated-carbonyl end" of the asymmetrical
polyene is selected from the group consisting of structures a)
through c), as described herein, and wherein the "C--C double bond
end" of the asymmetrical polyene is selected from the group
consisting of structures 1) through 17), as described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0009] In one embodiment the invention is a process to form a
composition comprising an asymmetrical polyene, the asymmetrical
polyene comprising an ".alpha.,.beta.0 unsaturated-carbonyl end"
and a "C--C double bond end," the process comprising reacting an
alkene- or polyene-containing alcohol with an alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid in the presence of at
least the following components A) through C), to form a solution
comprising the asymmetrical polyene: [0010] A) a lithium salt;
[0011] B) a component selected from the group consisting of
hydroquinone, an alkyl-substituted phenol, a substituted
alkyl-substituted phenol, an alkyl-substituted hydroquinone, a
substituted alkyl-substituted hydroquinone, and combinations
thereof; and [0012] C) an N-oxyl-containing compound; wherein the
".alpha.,.beta.0 unsaturated-carbonyl end" of the asymmetrical
polyene is selected from the group consisting of structures a)
through c), as described herein, and wherein the "C--C double bond
end" of the asymmetrical polyene is selected from the group
consisting of structures 1) through 17), as described herein.
[0013] An inventive process may comprise a combination of two or
more embodiments described herein.
Alkene- or Polyene-Containing Alcohol
[0014] In one embodiment, the transesterification process of the
present invention produces an asymmetrical polyene and involves a
first step of reacting an alkene- or polyene-containing alcohol
with an alkyl ester of an .alpha.,.beta. unsaturated carboxylic
acid. The term "alkene- or polyene-containing alcohol," as used
herein, refers to an organic compound comprising at least one C--C
double bond and at least one hydroxyl group.
[0015] In one embodiment, the alkene- or polyene-containing alcohol
comprises an alcohol selected from the group consisting of the
following:
##STR00001##
wherein R5 is selected from H or a C1-C6 alkyl;
##STR00002##
wherein R6 is selected from H or a C1-C6 alkyl;
##STR00003##
wherein R7 is selected from H or a C1-C6 alkyl;
##STR00004## ##STR00005##
wherein m=1 to 20.
[0016] In the structures A) through Q) above, the dashed line (---)
represents a bond.
[0017] In the structures A) through Q) above, each Z group is
independently H or a polyalkylene oxide with the structure:
##STR00006##
wherein R and R' are independently selected from H, CH.sub.3, or
CH.sub.3CH.sub.2, and n is from 0 to 50, and wherein the dashed
line (---) represents the connecting bond between the alcohol
functionality of the alkene- or polyene-containing alcohol with the
polyalkylene oxide moiety.
[0018] Peroxides are often present in alkene- or polyene-containing
alcohols and their derivatives. These peroxides are undesired
because of their propensity to (i) induce unwanted polymer
formation from the .alpha.,.beta.-unsaturated carboxylates present
within the compositions disclosed here, and (ii) produce unwanted
byproducts, which can impact downstream applications.
[0019] In one embodiment, the alkene- or polyene-containing
alcohols used in the present transesterification process preferably
have a peroxide level less than 50 ppm, or more preferably less
than 20 ppm, or most preferably less than 10 ppm, based on the
total weight of the alcohol.
[0020] In one embodiment, suitable alkene- or polyene-containing
alcohols useful in the present transesterification process include,
and are not limited to, polypropylene glycol mono-allyl ether and
polyethylene glycol mono-allyl ether.
[0021] In one embodiment, the alkene- or polyene-containing alcohol
is an alkene-containing alcohol.
[0022] In one embodiment, the alkene-containing alcohol is
preferably polypropylene glycol allyl ether having the
structure:
##STR00007##
wherein n is 1-20, more preferably 1-15, and even more preferably
1-10; R.sub.a is selected from H or an alkyl (preferably ethyl or
methyl, and more preferably methyl); R.sub.b is selected from H or
an alkyl (preferably ethyl or methyl, and more preferably methyl);
and preferably wherein R.sub.a and R.sub.b are selected from the
group consisting of (i) R.sub.a and R.sub.b are both H, (ii) when
R.sub.a is methyl, then R.sub.b is H, and (iii) when R.sub.a is H,
then R.sub.b is methyl.
[0023] Typically, the amount of the alcohol present in the
transesterification process described herein is the limiting
reactant.
[0024] In one embodiment, an alkene- or polyene-containing alcohol
may comprise one or more embodiments as described herein. In one
embodiment, an alkene- or polyene-containing alcohol may comprise a
combination of two or more embodiments as described herein.
Alkyl Ester of an Alpha, Beta-Unsaturated Carboxylic Acid
[0025] In one embodiment, the transesterification process of the
present invention produces an asymmetrical polyene and involves a
first step of reacting an alkene- or polyene-containing alcohol, as
described above, with an alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid (or .alpha.,.beta. unsaturated
carboxylic ester). The term "alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid," as used herein, refers to an organic
compound comprising at least one carbonyl group (CO) and a C--C
double bond adjacent to the carbonyl group.
[0026] In one embodiment, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid comprises an alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid selected from the group
consisting of the following:
##STR00008##
wherein R.sub.1 is H or CH.sub.3 and each R.sub.2 is,
independently, a linear or branched C.sub.1 to C.sub.8 alkyl.
[0027] In one embodiment, suitable alkyl esters of .alpha.,.beta.
unsaturated carboxylic acids useful in the transesterification
process of the present disclosure include, and are not limited to,
methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl
methacrylate, methyl itaconate, ethyl itaconate, and butyl
itoconate and combinations thereof.
[0028] In one embodiment, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid is preferably selected from methyl
acrylate and methyl methacrylate. In one embodiment, the alkyl
ester of an .alpha.,.beta. unsaturated carboxylic acid is more
preferably methyl methacrylate.
[0029] In one embodiment, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid comprises methyl methacrylate having
the structure (III):
##STR00009##
[0030] Typically, the amount of alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid in the reaction mixture is in
stoichiometric excess to the amount of alkene- or
polyene-containing alcohol present. In one embodiment, the mole
ratio of alkene or polyene-containing alcohol to alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid is from 1:1.2 to
1:20.
[0031] In a more preferred embodiment, the mole ratio of alkene- or
polyene-containing alcohol to alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid is from 1:1.12 to 1:10.
[0032] In an even more preferred embodiment, the mole ratio of
alkene- or polyene-containing alcohol to alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid is from 1:2 to 1:6.5
[0033] In the most preferred embodiment, the mole ratio of alkene-
or polyene-containing alcohol to alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid is from 1:2 to 1:5.
[0034] In one embodiment, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid comprises one or more embodiments as
described herein. In one embodiment, the alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid comprises a combination
of two or more embodiments as described herein.
Lithium Salt
[0035] In one embodiment, the process of the invention is a
transesterification process comprising reacting an alkene- or
polyene-containing alcohol with an alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid in the presence of at least A) a
lithium salt ("component A"); B) a component selected from the
group consisting of hydroquinone, an alkyl-substituted phenol, a
substituted alkyl-substituted phenol, an alkyl-substituted
hydroquinone, a substituted alkyl-substituted hydroquinone, and
combinations thereof ("component B"); and C) an N-oxyl-containing
compound ("component C").
[0036] In one embodiment, the lithium salt (component A) comprises
a single lithium salt.
[0037] In one embodiment, the lithium salt is a mixture of two or
more lithium salts.
[0038] In one embodiment, the lithium salt is part of a mixed salt
catalyst, such as those known for catalyzing transesterification
processes and described in US 2007/028784.
[0039] In one embodiment, the lithium salt is selected from the
group consisting of lithium salts having the general formula
Li.sub.nX, wherein n is from 1 to 2 and X is selected from the
group consisting of hydroxide, oxide, halide, sulfate, bisulfate,
sulfonate, phosphate, phosphonate, perchlorate, nitrate, alkoxide
(RO.sup.-, wherein R is a straight chain or branched alkyl group
having 1 to 8 carbon atoms), phenoxide, carbonate (i.e.
CO.sub.3.sup.-2), bicarbonate (i.e. HCO.sub.3.sup.-), alkonate
(RCO.sub.2.sup.-, wherein R is a straight chain or branched alkyl
having 1-8 carbon atoms), alkenoates (RCO.sub.2.sup.- wherein R is
an olefin such as --C.dbd.C-- or --C.dbd.C(CH.sub.3)--), or any
other stable anionic moieties capable of forming ionic salts.
[0040] In one embodiment, the lithium salt is selected from the
group consisting of lithium salts having the general formula
Li.sub.nX, wherein n is from 1 to 2 and X is selected from the
group consisting of hydroxide, oxide, halide, sulfate, bisulfate,
sulfonate, phosphate, phosphonate, perchlorate, nitrate, alkoxide
(RO.sup.-, wherein R is a straight chain or branched alkyl group
having 1 to 8 carbon atoms), phenoxide, carbonate (i.e.
CO.sub.3.sup.-2), bicarbonate (i.e. HCO.sub.3.sup.-), alkonate
(RCO.sub.2.sup.-, wherein R is a straight chain or branched alkyl
having 1-8 carbon atoms), and alkenoates (RCO.sub.2.sup.- wherein R
is an olefin such as --C.dbd.C-- or --C.dbd.C(CH.sub.3)--).
[0041] In one embodiment, the lithium salt is a lithium salt having
the general formula Li.sub.nX, as described above, and may include
the following structures:
Li.sup.+.sub.nX.sup.-,
wherein n is from 1 to 2, X is selected from the group consisting
of OR, O.sup.-2, a halide (including, but not limited to, Cl, Br,
I, and F), OR.sup.-, CO.sub.3.sup.-2, HCO.sub.3.sup.-, and
R'CO.sub.2.sup.+; wherein R is selected from a C.sub.1-C.sub.8
straight chain or branched alkyl group or from an aryl group; and
wherein R' is selected from a C.sub.1-C.sub.8 straight chain or
branched alkyl group, an aryl group, or a C.sub.1-C.sub.3 alkene
group (including, but not limited to, --C.dbd.C-- or
--C.dbd.C(CH.sub.3)--).
[0042] In one embodiment, the lithium salt is selected from the
group consisting of lithium hydroxide, anhydrous lithium hydroxide,
lithium methoxide, lithium carbonate, lithium chloride, lithium
acetate, and lithium methacrylate, and combinations thereof.
[0043] In one embodiment, the lithium salt preferably comprises
anhydrous lithium hydroxide.
[0044] In one embodiment, the amount of lithium salt used in the
inventive process is from 0.1 to 10 mole %, or more preferably from
0.5 to 5 mole %, or most preferably from 1 to 2 mole %, based on
the total moles of alkene- or polyene-containing alcohol in the
reaction mixture.
[0045] In one embodiment, the lithium salt comprises one or more
embodiments described herein.
[0046] Typically, lithium salt catalysts, such as those described
herein, perform best when water is removed from the reactants prior
to starting the transesterification reaction. Low levels of water
sometimes found in the starting reactants, such as the alkene- or
polyene-containing alcohols and for the alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid, can be removed, prior
to the addition of the lithium salt by, for example, simple
distillation of the reaction mixture until a small amount of the
alkyl ester of an .alpha.,.beta. unsaturated carboxylic acid is
distilled overhead. Typically, less than 5% of the starting alkyl
ester of an .alpha.,.beta. unsaturated carboxylic acid is removed
by distillation from the alcohol/carboxylate mixture. More
preferably, less than 3% of the starting alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid is removed by
distillation. Most preferably, less than 2% of the starting alkyl
ester of an .alpha.,.beta. unsaturated carboxylic acid is removed
by distillation.
[0047] In one embodiment, distillation is carried out until water
levels within the composition containing the alkene- or
polyene-containing alcohol and the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid is less than 0.10%, more preferably
less than 0.05%, and most preferably less than 0.03% by weight
based on the total weight of the solution including the alkene- or
polyene-containing alcohol and alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid.
[0048] In one embodiment, the water level is most preferably less
than 0.03% by weight based on the total weight of the solution
including the alkene- or polyene-containing alcohol and alkyl ester
of an .alpha.,.beta. unsaturated carboxylic acid prior to adding
the lithium salt.
Inhibitors
[0049] In one embodiment, the alkene- or polyene-containing alcohol
and alkyl ester of an .alpha.,.beta. unsaturated carboxylic acid
are reacted in the presence of at least two inhibitors. Inhibitors
prevent the monomers of alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid present, including the asymmetrical
polyene monomers formed by the inventive process, from polymerizing
during transesterification and during storage. Inhibitors may also
impact process stability for downstream applications.
[0050] In one embodiment, inhibitors include, and are not limited
to, oxygen; diethylhydroxylamine; benzoquinone; hydroquinone (HQ);
alkyl ethers of hydroquinone and derivatives thereof (including,
for example, the methyl ether of hydroquinone (MeHQ) and
derivatives thereof); phenothiazine; 2,3-dihydroxylnapthalene;
dialkylpara-cresol (including, for example,
2,6-di-t-butylpara-cresol); dialkyl-4-hydroxyanisole (including,
for example, 3,5-di-t-butyl-4-hydroxyanisole);
dialkylhydroxyanisole (including, for example,
2,5-di-t-butylhydroxyanisole); trialkylphenol (including, for
example, 2,4,6-tri-tert-butylphenol); dialkyl-6-alkylphenol
(including, for example, 2,4-dimethyl-6-tert-butylphenol (topanol
A)); 4-hydroxy-2,2,6,6-tetra-alkyl piperidinyloxy free radical and
derivatives thereof (including, for example,
4-hydroxy-2,2,6,6-tetramethyl piperidinyloxy free radical
(4-hydroxy-TEMPO or 4-HT) and derivatives thereof);
4-methacryloyloxy-2,2,6,6-tetraalkyl piperidinyloxy free radicals
(including, for example, 4-methacryloyloxy-2,2,6,6-tetramethyl
piperidinyloxy free radical); and 4-hydroxy-2,2,6,6-tetraalkyl
N-hydroxy piperidine (including, for example,
4-hydroxy-2,2,6,6-tetramethyl N-hydroxy piperidine);
2,2,5,5-tetraalkyl-3-oxopyrrolidine-1-oxyl free radical and
derivatives thereof (including, for example,
2,2,5,5-tetramethyl-3-oxopyrrolidine-1-oxyl free radical);
2,2,6,6-tetraalkylpiperidine-1-oxyl free radical and derivatives
thereof (including, for example,
2,2,6,6-tetramethylpiperidine-1-oxyl free radical);
tris(2,2,6,6-tetraalkylpiperidine-1-oxyl-4-yl)-phosphite and
derivatives thereof (including, for example,
tris(2,2,6,6-tetramethylpiperidine-1-oxyl-4-yl)-phosphite); and
mixtures thereof.
[0051] In the exemplary inhibitors described above, the alkyl group
may be a substituted alkyl or unsubstituted alkyl group.
[0052] In one embodiment, the total amount of inhibitor used in the
inventive process is at least 100 ppm to at most 3,500 ppm, or more
preferably at most 2,500 ppm, or most preferably at most 2,000 ppm,
based on the amount in weight of alkene- or polyene-containing
alcohol.
[0053] In one embodiment, the total amount of inhibitor in the
reaction mixture is from 200 to 2,500 ppm based on the amount in
weight of alkene- or polyene-containing alcohol.
[0054] In one embodiment, a combination of at least two inhibitors
is used.
[0055] In one embodiment, a combination of at least two inhibitors
is used, wherein the first inhibitor is a hydroquinone- or
phenol-type inhibitor (including, for example, hydroquinone, alkyl
substituted phenol, or alkyl substituted hydroquinone), and wherein
the second inhibitor is an N-oxyl-containing compound.
[0056] In one embodiment, a combination of at least two inhibitors
is used, wherein the first inhibitor (component B) comprises a
component selected from the group consisting of hydroquinone, an
alkyl-substituted phenol, a substituted alkyl-substituted phenol,
an alkyl-substituted hydroquinone, a substituted alkyl-substituted
hydroquinone, and combinations thereof, and wherein the second
inhibitor (component C) comprises a piperidinyloxy radical-type
inhibitor (including piperidinyloxy radicals with an alkyl- or
hydroxyl-substitution on the cyclic ring structure).
[0057] In one embodiment, a combination of at least two inhibitors
is used, wherein the first inhibitor (component B) comprises a
component selected from the group consisting of hydroquinone, an
alkyl-substituted phenol, an alkyl-substituted hydroquinone, and
combinations thereof, and wherein the second inhibitor (component
C) comprises a piperidinyloxy radical-type inhibitor (including
piperidinyloxy radicals with an alkyl- or hydroxyl-substitution on
the cyclic ring structure).
[0058] In one embodiment, component B has the general structure
(IV)
##STR00010##
wherein X is R or OR; R is CH.sub.3 or H; and each R', R'', R'''
and R''' is, independently, H, a straight chain or branched alkyl
group with 1 to 20 carbons, or an aromatic group, including
aromatic groups comprising a single aromatic ring or multiple
aromatic rings which are fused together, linked covalently, or
share a common bond.
[0059] In one embodiment, component B is selected from the group
consisting of MeHQ, derivatives of MeHQ, and HQ.
[0060] In one embodiment, component B is MeHQ or HQ, as shown in
structures (V) and (VI), respectively, below.
##STR00011##
[0061] In one embodiment, the concentration of component B is from
50 to 3,000 ppm, more preferably from 100 to 2,000 ppm, and most
preferably from 250 to 1,500 ppm by weight based on the weight of
asymmetrical polyene.
[0062] In one embodiment, the second inhibitor comprises an
N-oxyl-containing compound (component C). The term
"N-oxyl-containing compound," as used herein, refers to any
compound and/or chemical substance containing the structural
fragment
##STR00012##
wherein the "." represents a radical (electron), and each
##STR00013##
represents a portion of a covalent bond to a quaternary carbon
atom.
[0063] In one embodiment, component C (the N-oxyl-containing
compound) is selected from the group consisting of
2,2,5,5-tetramethyl-3-oxopyrrolidine-1-oxyl free radical;
2,2,6,6-tetramethylpiperidine-1-oxyl free radical;
tris(2,2,6,6-tetramethylpiperidine-1-oxyl-4-yl)-phosphite; and
4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical
(4-hydroxy TEMPO, or 4-HT); and derivatives of these compounds.
[0064] As used herein, the terms
"4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl free radical" and
"4-hydroxy-TEMPO" are synonymous and refer to a compound with the
structure (VII)
##STR00014##
wherein X is H, --OH, or --OR; and each R--R''' is, independently H
or an alkyl. In one embodiment, each R--R''' is preferably
CH.sub.3.
[0065] In one embodiment, component C is preferably selected from
the group consisting of 4-hydroxy TEMPO and derivatives
thereof.
[0066] In one embodiment, component C is preferably 4-hydroxy
TEMPO.
[0067] In an embodiment, the concentration of component C (the
N-oxyl-containing compound) used in the process described herein is
less than that of component B.
[0068] In one embodiment, the concentration of component C is from
50 to 250 ppm, or more preferably from 75 to 125 ppm by weight
based on the weight of asymmetrical polyene.
Asymmetrical Polyenes
[0069] In one embodiment, the inventive process is a
transesterification process to form a composition comprising an
asymmetrical polyene which contains an ".alpha.,.beta.
unsaturated-carbonyl end" and a "C--C double bond end." The
asymmetrical polyenes resulting from the process described herein
are useful as monomers in further polymerization reactions.
[0070] In one embodiment, the ".alpha.,.beta. unsaturated-carbonyl
end" of the asymmetrical polyene is selected from the group
consisting of the following:
##STR00015##
wherein R.sub.1 is selected from H or a C.sub.1-C.sub.6 alkyl
(preferably a C.sub.1-C.sub.3 alkyl and more preferably
CH.sub.3);
##STR00016##
wherein R.sub.2 is selected from H or a C.sub.1-C.sub.6 alkyl
(preferably a C.sub.1-C.sub.3 alkyl and more preferably CH.sub.3);
R.sub.3 is selected from H, CH.sub.3, or CH.sub.2CH.sub.3; R.sub.4
is selected from H, CH.sub.3, or CH.sub.2CH.sub.3; and n is from 1
to 50, or from 1 to 20, or further from 1 to 10; and
##STR00017##
[0071] In the structures a) through c) above, the notation
represents a break at the center of a covalent bond between the
".alpha.,.beta. unsaturated-carbonyl end" of the asymmetrical
polyene and the remaining chemical structure of the asymmetrical
polyene.
[0072] In one embodiment, the ".alpha.,.beta.0 unsaturated-carbonyl
end" of the asymmetrical polyene is a) as shown above.
[0073] In one embodiment, the ".alpha.,.beta.0 unsaturated-carbonyl
end" of the asymmetrical polyene is selected from the group
consisting of the following: b) and c), each as shown above, and in
a further embodiment, b) wherein R.sub.3 and R.sub.4 are both H; or
when R.sub.3 is CH.sub.3 or CH.sub.2CH.sub.3, then R.sub.4 is H; or
when R.sub.4 is CH.sub.3 or CH.sub.2CH.sub.3, then R.sub.3 is
H.
[0074] In one embodiment, the ".alpha.,.beta.0 unsaturated-carbonyl
end" of the asymmetrical polyene is b) as shown above. In a further
embodiment, the ".alpha.,.beta.0 unsaturated-carbonyl end" of the
asymmetrical polyene is b) as shown above, and in a further
embodiment, b) wherein R.sub.3 and R.sub.4 are both H, or when
R.sub.3 is CH.sub.3 or CH.sub.2CH.sub.3, and R.sub.4 is H, or when
R.sub.4 is CH.sub.3 or CH.sub.2CH.sub.3, and R.sub.3 is H.
[0075] In one embodiment, the ".alpha.,.beta.0 unsaturated-carbonyl
end" of the asymmetrical polyene is c) as shown above.
[0076] In one embodiment, the "C--C double bond end" of the
asymmetrical polyene is selected from the group consisting of the
following:
##STR00018##
wherein R5 is selected from H or C1-C6 alkyl;
##STR00019##
wherein R6 is selected from H or C1-C6 alkyl;
##STR00020##
wherein R7 is selected from H or C1-C6 alkyl;
##STR00021## ##STR00022##
wherein m=1 to 20.
[0077] In the structures 1) through 17) above, the notation
represents a break at the center of a covalent bond between the
"C--C double bond end" of the asymmetrical polyene and the
remaining chemical structure of the asymmetrical polyene.
[0078] In one embodiment, the "C--C double bond end" of the
asymmetrical polyene is selected from the group consisting of the
following: 1)-15) and 17), each as shown above.
[0079] In one embodiment, the "C--C double bond end" of the
asymmetrical polyene is selected from the group consisting of the
following: 1), 2), 3), 4), 5), 6), 7), 8), 9), 10), 11), 12), and
17), each as shown above.
[0080] In one embodiment, the "C--C double bond end" of the
asymmetrical polyene is selected from the group consisting of the
following: 1), 2), 3), 12), and 17) each as shown above.
[0081] In one embodiment, the "C--C double bond end" of the
asymmetrical polyene is selected from the group consisting of the
following: 13), 14), 15) and 16), each as shown above.
[0082] In one embodiment, the asymmetrical polyene is selected from
the group consisting of the following:
##STR00023##
wherein n is from 1 to 50, further from 1 to 20 and further from 1
to 10; R.sub.a is selected from H or an alkyl (preferably ethyl or
methyl and more preferably methyl); R.sub.b is selected from H or
an alkyl (preferably ethyl or methyl and more preferably methyl);
and preferably wherein R.sub.a and R.sub.b are selected from the
group consisting of (i) R.sub.a and R.sub.b are both H, (ii) when
R.sub.a is methyl, then R.sub.b is H, and (iii) when R.sub.a is H,
then R.sub.b is methyl;
##STR00024##
wherein m=1 to 20.
[0083] In one embodiment, the asymmetrical polyene is selected from
the group consisting of the following: i), ii), iii), iv) and v),
each as shown above.
[0084] In one embodiment, the asymmetrical polyene is selected from
the group consisting of the following: i) and v), each as shown
above.
[0085] In one embodiment, the asymmetrical polyene is selected from
the group consisting of the following: vi), vii), and viii), each
as shown above.
[0086] In one embodiment, the asymmetrical polyene is polypropylene
glycol allyl ether methacrylate (PPG AEMA) having the structure
##STR00025##
wherein n is from 1 to 50, further from 1 to 20 and further from 1
to 10; R.sub.a is selected from H or an alkyl (preferably ethyl or
methyl and more preferably methyl); R.sub.b is selected from H or
an alkyl (preferably ethyl or methyl and more preferably methyl);
and preferably wherein R.sub.a and R.sub.b are selected from the
group consisting of (i) R.sub.a and R.sub.b are both H, (ii) when
R.sub.a is methyl, then R.sub.b is H, and (iii) when R.sub.a is H,
then R.sub.b is methyl.
Asymmetrical Polyene Composition
[0087] In an embodiment, the present invention provides a
composition comprising the asymmetrical polyene composition. The
composition may include an asymmetrical polyene, inhibitors, and
lithium salt.
[0088] In one embodiment, the total amount of inhibitor and/or
derivative(s) thereof present in the asymmetrical polyene
composition is from 75 to 3,500 ppm.
[0089] In one embodiment, when a combination of at least two
inhibitors (component B and component C) is used, the amount of
first inhibitor and/or derivative(s) thereof (component B) present
in the asymmetrical polyene composition is from 50 to 3000 ppm
based on the weight of the composition, and the amount of the
second inhibitor and/or derivative(s) thereof (component C) present
in the asymmetrical polyene composition is from 25 to 500 ppm based
on the weight of the composition.
[0090] In one embodiment, the asymmetrical polyene composition
includes an asymmetrical polyene and, preferably, less than 100 ppm
of the second inhibitor (component C), which is an
N-oxyl-containing compound and/or derivative(s) thereof, wherein
the ppm is based on the weight of the asymmetrical polyene.
[0091] In one embodiment, the asymmetrical polyene composition
includes an asymmetrical polyene and, preferably, from 500 ppm to
1500 ppm of the first inhibitor (component B), and 75 ppm of the
second inhibitor (component C), wherein the ppm is based on the
weight of the asymmetrical polyene.
[0092] In one embodiment, the amount of first and second inhibitor
(components B and C) present in the asymmetrical polyene
composition is determined by mass balance equation.
[0093] In one embodiment, the asymmetrical polyene composition
comprise less than 100 ppm of an inhibitor selected from the group
consisting of 4-HT, and/or derivatives thereof, and less than 2000
ppm MeHQ and/or derivatives thereof, each based on the weight of
the composition. In one embodiment, the amount of 4-HT and/or its
derivatives in ppm is determined from a mass balance equation. In
one embodiment, the amount of MeHQ and/or derivatives thereof in
ppm is determined using HPLC or GC.
[0094] In one embodiment, the composition comprises unreacted
alkene- or polyene-containing alcohol and/or unreacted alkyl ester
of an .alpha.,.beta. unsaturated carboxylic acid in addition to
asymmetrical polyene, inhibitors, and lithium salt. In one
embodiment, the composition comprises from 2% to 10%, or from 2% to
8%, or from 2% to 6%, or from 2% to 4%, by weight, of unreacted
alkene- or polyene-containing alcohol, based on the total weight of
the composition. In one embodiment, the composition comprises less
than 10%, or less than 8%, or less than 6%, or less than 2%, by
weight, of unreacted alkene- or polyene-containing alcohol, based
on the total weight of the composition. In one embodiment, the
composition may include by-products, such as Michael adducts. In
one embodiment, the composition comprises from 2% to 10%, or from
2% to 8%, or from 2% to 6%, or from 2% to 4%, by weight, of Michael
adducts based on the total weight of the composition. In one
embodiment, the composition comprises less than 10%, or less than
8%, or less than 6%, or less than 4%, by weight, of Michael
adducts, based on the total weight of the composition.
Applications
[0095] In one embodiment, the invention includes an asymmetrical
polyene made an inventive process described herein.
[0096] In one embodiment, the asymmetrical polyene or asymmetrical
polyene composition may be used to form a polymer. In one
embodiment, the polymer is an ethylene-based polymer. In one
embodiment, the polymer is low density polyethylene (LDPE).
[0097] In one embodiment, the polymer, made using the asymmetrical
polyene composition, and polymer blends, and/or compositions
including the asymmetrical polyene, may be used to form an article
or at least one component of an article.
[0098] In one embodiment, the polymer made using the asymmetrical
polyene composition, and polymer blends, and/or composition
including the asymmetrical polyene, may be employed in a variety of
conventional thermoplastic fabrication processes to produce useful
articles, including extrusion coating onto various substrates;
monolayer and multilayer films; molded articles, such as blow
molded, injection molded, or rotomolded articles; coatings; fibers;
and woven or non-woven fabrics.
[0099] In one embodiment, a polymer made using the symmetrical
polyene composition, and polymer blends, and/or compositions
including the asymmetrical polyene, may be used in a variety of
films, including but not limited to, clarity shrink films,
collation shrink films, cast stretch films, silage films, stretch
hood, sealants, and diaper backsheets.
[0100] Other suitable applications include, but are not limited to,
wires and cables, gaskets and profiles, adhesives; footwear
components, and auto interior parts.
Transesterification Process
[0101] In an embodiment, the present invention is a
transesterification process to form a composition comprising an
asymmetrical polyene which contains an ".alpha.,.beta.0
unsaturated-carbonyl end" and a "C--C double bond end," the process
comprising reacting an alkene- or polyene-containing alcohol with
an alkyl ester of an .alpha., .beta. unsaturated carboxylic acid in
the presence of at least the following components: A) a lithium
salt; B) a hydroquinone, alkyl-substituted phenol, or
alkyl-substituted hydroquinone; and C) an N-oxyl-containing
compound to form a solution comprising the asymmetrical polyene,
and wherein the ".alpha.,.beta.0 unsaturated-carbonyl end" of the
asymmetrical polyene is selected from the group consisting of
structure a)-c), as described herein, and the "C--C double bond
end" of the asymmetrical polyene is selected form the group
consisting of structures 1)-17), as described herein.
[0102] In one embodiment, the alkene- or polyene-containing
alcohol, the .alpha.,.beta. unsaturated carboxylic ester, lithium
salt (component A) and inhibitors (components B and C) may be added
to the reaction in any order.
[0103] In one embodiment, the alkene- or polyene-containing
alcohol, the alkyl ester of an .alpha.,.beta. unsaturated
carboxylic acid and the inhibitors (components B and C) are first
combined, followed by addition of the lithium salt (component A).
In another embodiment, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid and inhibitors (components B and C) are
first combined, followed by the addition of the alkene- or
polyene-containing alcohol, and, separately, the lithium salt
(component A).
[0104] In one embodiment, most preferably, the alkene- or
polyene-containing alcohol, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid and the inhibitors (components B and C)
are first combined, and the resulting mixture is heated to distill
a small amount of the alkyl ester of an .alpha.,.beta. unsaturated
carboxylic acid overhead to help remove low levels of water which
may be present in the raw materials (i.e., alkene- or
polyene-containing alcohol, alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid and inhibitors). After the dehydration,
the lithium salt (component A) is added to the reaction.
[0105] In one embodiment, after the alkene- or polyene-containing
alcohol, alkyl ester of an .alpha., .beta. unsaturated carboxylic
acid, inhibitors (components B and C) and lithium salt (component
A) are each added to the reaction, the reaction mixture is heated
to above 60.degree. C., and preferably to a reaction temperature
which ranges from 70.degree. C. to 140.degree. C., for
transesterification to occur.
[0106] In one embodiment, the reaction temperature is preferably
from 70.degree. C. to 125.degree. C., more preferably from
80.degree. C. to 120.degree. C., or most preferably from 85.degree.
C. to 100.degree. C.
[0107] In one embodiment, the reaction pressure is typically from
760 mmHg to reduced pressures. Preferably, the reaction pressure is
from 250 to 760 mmHg, or more preferably from 400 to 760 mmHg.
[0108] In one embodiment, the reaction time is typically from 3 to
48 hours, and preferably from 5 to 18 hours, and most preferably 6
to 12 hours.
[0109] In one embodiment, the reactor overhead can possess either a
packed or trayed distillation column or other means to help
establish an azeotrope between the alkyl ester of an .alpha.,
.beta. unsaturated carboxylic acid [e.g. (meth)acrylate ester] and
the alcohol of reaction, or alcohol2, which is the corresponding
alcohol from the ester portion of the alkyl ester of an .alpha.,
.beta. unsaturated carboxylic acid (for example, methanol would be
formed from transesterification reactions involving methyl
methacrylate). The azeotrope typically is composed of a higher
concentration of the alcohol2 over the (meth)acrylate. In this way,
the by-product alcohol2 can be removed with minimum loss of the
(meth)acrylate raw material.
Removal of Excess Alkyl Ester of an .alpha.,.beta. Unsaturated
Carboxylic Acid
[0110] In one embodiment, the process of the present invention
includes removing excess alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid.
[0111] In one embodiment, the step of removing excess alkyl ester
of an .alpha.,.beta. unsaturated carboxylic acid comprises cooling
the asymmetrical polyene solution and distilling the alkyl ester of
an .alpha.,.beta. unsaturated carboxylic acid. In one embodiment,
the solution is cooled to below 50.degree. C.
[0112] In one embodiment, the alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid is distilled using a straight lead
distillation tower.
[0113] In one embodiment, the distillation rate is maintained such
that distillation is complete in 1 to 4 hours, or preferably 1 to 3
hours, or more preferably 1 to 3 hours, or most preferably 1 to 20
hours.
[0114] In one embodiment, the step of removing excess alkyl ester
of an .alpha.,.beta. unsaturated carboxylic acid comprises cooling
the asymmetrical polyene solution, preferably to below 50.degree.
C., and applying a vacuum to bring the pressure down to less than
or equal to 200 mmHg prior to distilling the alkyl ester of an
.alpha.,.beta. unsaturated carboxylic acid.
[0115] In one embodiment, the solution is heated to a temperature
of greater than or equal to 70.degree. C. after attaining a
pressure of less than or equal to 200 mmHg and prior to distilling
the alkyl ester of an .alpha.,.beta. unsaturated carboxylic
acid.
[0116] In one embodiment, in order to obtain a distillation rate
such that distillation is complete in 1 to 4 hours, or preferably 1
to 3 hours, or more preferably 1 to 3 hours, or most preferably 1
to 20 hours, the pressure is decreased during distillation while
the temperature is increased. In one embodiment, in order to obtain
the desired distillation rate, the pressure is decreased over about
1 hour to 30 mmHg and the temperature is increases during that 1
hour to 88.degree. C. to 92.degree. C., or preferably 90.degree. C.
If possible, the pressure may be further decreased over an
additional 15 to 30 minutes while the temperature is maintained at
88.degree. C. to 92.degree. C., or preferably 90.degree. C.
[0117] In one embodiment, excess alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid removal is complete when no more alkyl
ester of an .alpha.,.beta. unsaturated carboxylic acid appears
overhead after the asymmetrical polyene solution reaches a pressure
of less than or equal to 30 mmHg and a temperature of 90.degree. C.
In one embodiment, excess alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid removal is complete when the amount of
alkyl ester of an .alpha.,.beta. unsaturated carboxylic acid in the
asymmetrical polyene solution is less than or equal to 0.5 weight
percent, or preferably less than 0.5 weight percent, as measured by
chromatography.
[0118] In one embodiment, excess alkyl ester of an .alpha.,.beta.
unsaturated carboxylic acid removed is recycled and used in further
reaction with alkene- or polyene-containing alcohol to form
additional asymmetrical polyene, as described herein.
Lithium Salt Removal
[0119] In one embodiment, the process of the present invention
includes filtering the asymmetrical polyene solution. Filtering the
asymmetrical polyene solution may remove lithium salt (component A)
present in the solution.
[0120] In one embodiment, the process includes filtering the
asymmetrical polyene solution using a 10 micron or less filter, or
a 5 micron or less filter, or a 2 micron or less filter, or a 1
micron or less filter.
[0121] In one embodiment, the process of the present invention
includes cooling the asymmetrical polyene solution.
[0122] In one embodiment, the process includes cooling the
asymmetrical polyene solution to a temperature of less than or
equal to 5.degree. C., or less than or equal to 4.degree. C., or
less than or equal to 3.degree. C., or preferably, less than or
equal to 2.degree. C.
[0123] In an embodiment, the transesterification process of the
present invention comprises filtering the asymmetrical polyene
solution at a temperature of less than or equal to 5.degree. C.,
using a 10 micron or less filter, or a 5 micron or less filter, or
a 2 micron or less filter, or a 1 micron or less filter.
[0124] In one embodiment, after transesterification and/or excess
alkyl ester of an .alpha., .beta. unsaturated carboxylic acid
removal, the temperature of the asymmetrical polyene solution is
decreased to less than or equal to 5.degree. C., to cause the
lithium salt to precipitate out of solution before filtration.
[0125] In one embodiment, the asymmetrical polyene solution is
filtered at a temperature of less than or equal to 5.degree. C., or
less than or equal to 4.degree. C., or less than or equal to
3.degree. C., or preferably, less than or equal to 2.degree. C., or
preferably less than 0.degree. C., using a 10 micron or less
filter, or a 5 micron or less filter, or a 2 micron or less filter,
or a 1 micron or less filter.
[0126] In one embodiment, the asymmetrical polyene solution is
filtered at a temperature of less than or equal to 5.degree. C., or
less than or equal to 4.degree. C., or less than or equal to
3.degree. C., or preferably, less than or equal to 2.degree. C.
[0127] In one embodiment, and most preferably, the asymmetrical
polyene solution is filtered at a temperature of less than or equal
to 0.degree. C.
[0128] In some embodiments, the asymmetrical polyene solution may
be held at the temperature of less than or equal to 5.degree. C.,
for a period of at least 1 hour, or more preferably at least 2
hours, or most preferably at least 3 hours to allow the lithium
salt to precipitate prior to filtering.
[0129] Applicants surprisingly and unexpectedly discovered that
decreasing the temperature of the asymmetrical polyene solution,
following transesterification and/or excess alkyl ester of an
.alpha., .beta. unsaturated carboxylic acid removal, to less than
or equal to 5.degree. C., and filtering the asymmetrical polyene
solution, without the use of other additives or filter aids, at the
temperature of less than or equal to 5.degree. C., successfully
removed the lithium salt such that no visible haze is observed
within the final asymmetrical polyene composition, even after then
standing at ambient temperatures for over 180 days.
[0130] In one embodiment, filtering the asymmetrical polyene
solution at a temperature of less than or equal to 5.degree. C.,
using 1 micron or smaller filter, also results in an asymmetrical
polyene solution, which, upon standing at ambient temperature for
up to 24 hours after filtration, or up to 72 hours after
filtration, or up to 60 days after filtration, or up to 180 days
after filtration showed little to no haze.
Definitions
[0131] Unless stated to the contrary, implicit from the context, or
customary in the art, all parts and percents are based on weight,
and all test methods are current as of the filing date of this
disclosure. For purposes of United States patent practice, the
contents of any referenced patent, patent application or
publication are incorporated by reference, in their entirety (or
its equivalent US version is so incorporated by reference),
especially with respect to the disclosure of definitions (to the
extent not inconsistent with any definitions specifically provided
in this disclosure) and general knowledge in the art.
[0132] The term "alkyl," as used herein, refers to a saturated
linear, cyclic, or branched hydrocarbon group. Nonlimiting examples
of suitable alkyl groups include, for example, methyl, ethyl,
n-propyl, i-propyl, n-butyl, t-butyl, i-butyl (or 2-methylpropyl),
etc. In one embodiment, the alkyls have 1 to 20 carbon atoms.
[0133] The term "substituted alkyl," as used herein, refers to an
alkyl as previously described in which one or more hydrogen atom
bound to any carbon of the alkyl is replaced by another group such
as a halogen, aryl, substituted aryl, cycloalkyl, substituted
cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl,
2-propenyl (or allyl), vinyl, haloalkyl, hydroxy, amino, phosphido,
alkoxy, amino, thio, nitro, unsaturated hydrocarbon, and
combinations thereof. Suitable substituted alkyls include, for
example, benzyl, trifluoromethyl and the like.
[0134] The term "composition," as used herein, includes a mixture
of materials which comprise the composition, as well as reaction
products and decomposition products formed from the materials of
the composition.
[0135] "Comprising", "including", "having" and like terms are not
intended to exclude the presence of any additional component, step
or procedure, whether or not the same is specifically disclosed. In
order to avoid any doubt, all processes claimed through use of the
term "comprising" may include one or more additional steps, pieces
of equipment or component parts, and/or materials unless stated to
the contrary. In contrast, the term, "consisting essentially of"
excludes from the scope of any succeeding recitation any other
component, step or procedure, excepting those that are not
essential to operability. The term "consisting of" excludes any
component, step or procedure not specifically delineated or listed.
The term "or," unless stated otherwise, refers to the listed
members individually as well as in any combination.
[0136] The term "polymer" refers to a compound prepared by
polymerizing monomers, whether of the same or a different type. The
generic term polymer thus embraces the term homopolymer (which
refers to polymers prepared from only one type of monomer with the
understanding that trace amounts of impurities can be incorporated
into the polymer structure), and the term "interpolymer" as defined
below. Trace amounts of impurities may be incorporated into and/or
within the polymer.
[0137] The term "interpolymer" refers to polymers prepared by the
polymerization of at least two different types of monomers. The
generic term interpolymer includes copolymers (which refers to
polymers prepared from two different monomers), and polymers
prepared from more than two different types of monomers.
[0138] The term "blend," as used herein, refers to a mixture of two
or more components.
[0139] As used herein, the term "polyene" refers to a
poly-unsaturated compound having two or more carbon-carbon double
bonds.
[0140] The term "ethylene-based polymer" refers to a polymer that
comprises a majority amount of polymerized ethylene, based on the
weight of the polymer, and, optionally, at least one comonomer.
[0141] As used herein, the terms "R1," R2," and the like, are used
interchangeably with "R.sub.1," "R.sub.2" and the like to refer to
corresponding R groups forming part of a chemical structure.
Similarly, the terms "C1," "C2," and the like, are used
interchangeably with "C.sub.1," "C.sub.2" and the like to refer to
1- or 2-carbon groups, respectively.
Test Methods
[0142] Polymer observation during/after reaction: Polymer
observation is determined both by direct observation of reaction
and product samples, and also via solvent dilution tests, followed
by visual confirmation for lack of haze, solids, gels, coagulum,
stringy material, etc. For the solvent dilution tests, samples are
tested using both methanol and hexane. To prepare the samples, the
reaction mixture is evaluated at various stages, by mixing 1 gram
of reaction mixture or final product with 49 grams of anhydrous
methanol, for the methanol dilution test, or 49 grams of hexane,
for the hexane dilution test. Significant haze development upon
dilution, after 5 minutes, using either dilution test, indicates
formed polymer and a failed test. Extended storage stability tests
are run directly, by placing the monomer at 54.degree. C., and the
monomer samples need to last 60 days, without evidence of polymer
formation via these test methods. This would qualify the monomer
for acceptable storage times during commercial use.
[0143] Mass balance is employed for the determination of inhibitor
concentration.
[0144] Inhibitor concentrations may also be determined by HPLC
methods, as well as other methods known in the art.
EXPERIMENTAL
Example 1
[0145] Reaction Preparation:
[0146] A four-necked, 2-liter flask is equipped with a mechanical
stirrer, a sparge tube for 8% oxygen in nitrogen gas feed, and a
10-15 sieve-tray distillation column (or packed column), with a
condenser on top leading distillate, to a reflux splitter that
controls the amount of distillate going forward to a receiver,
versus back to the column as reflux; where the receiver leads to a
vacuum source that is controlled by a pressure transducer.
Thermocouples are placed, within the reactor flask and in the
overhead space above the column, to help monitor and control
temperatures at these locations. The reaction flask is charged with
400 grams of polypropyleneglycol mono-allyl ether (2 moles), 1000
grams of methyl methacrylate (MMA) (10 moles), and 0.8 grams of the
methyl ether of hydroquinone (MeHQ) and then sealed. In Example 2,
0.04 grams of 4-hydroxy-TEMPO (4H-TEMPO) is also added. In
addition, 0.2 grams of MeHQ are added to the overhead receiver to
inhibit MMA monomer that will collect there. Chilled water
(10.degree. C.) is fed to the coolant side of the overhead
condenser. The mechanical agitator is turned on and set to 100 rpm.
The 8% oxygen in the nitrogen sparge flow is started and maintained
at a flow rate of approximately 10 mls/minute.
[0147] Dehydration [Prior to Adding the Lithium Salt]:
[0148] Vacuum is then applied until the overhead pressure equals
550 mmHg. Once this pressure is attained, the reaction flask is
heated via a heating mantle, until the reaction mixture attains a
temperature of from 96.degree. C. to 100.degree. C. Under these
conditions, distillate fills the column (without flooding the
column trays) and is set to reflux completely back to the column.
The overhead temperature is monitored, establishing a distillate
temperature of from 88.degree. C. to 92.degree. C. Once these
conditions are attained, the distillate is taken forward at a 10:1
ratio of reflux:distillate, using the reflux splitter to control
this ratio. In this manner, approximately from 2% to 3% of the MMA
charge is taken overhead into the receiver. At this point, the
distillate is set back to full reflux mode via the reflux splitter,
while the water level is checked within the reaction mixture. If
the water level is greater than 0.03 weight %, then the
distillation is continued, as before, until another 1% to 2% MMA is
taken overhead, and the water level is again checked in the batch.
Once the water level in the reaction mixture is below 0.03 weight
%, then the batch is cooled to the 40.degree. C. to 60.degree. C.
range for charging the anhydrous LiOH.
[0149] Transesterification:
[0150] Once the batch is cooled to the 40.degree. C. to 60.degree.
C. range, and the pressure is raised to atmospheric, then 0.96
grams (0.04 moles) of anhydrous LiOH is added to the batch, and the
reactor is re-sealed. While still applying a sparge rate of about
10 ml/min and a stirrer rate of 100 rpm, vacuum is again applied
until the overhead pressure reads 550 mmHg. Once this pressure is
attained, the reactor is again heated toward and maintained at
96.degree. C. to 100.degree. C., to fill the column with distillate
without flooding the column trays. Full reflux is maintained, as
the overhead temperature drops from about 80.degree. C. to
approximately 56.degree. C. to 58.degree. C., over a 1 to 2 hour
period. This temperature drop in the overhead results from the
establishment of an MMA/methanol azeotrope that forms, which is
important to maintain during the course of the reaction for faster
methanol removal with minimum MMA loss. While the 56.degree. C. to
58.degree. C. overhead temperature is maintained, the distillate is
taken forward at a rate of 2.3:1 reflux:distillate ratio. As the
overhead temperature later rises above 60.degree. C., the overhead
should then be set to full reflux mode, until the overhead
temperature comes back down into the 56-58.degree. C. range. Once
this is accomplished, the overhead can be reset to the 2.3:1 reflux
ratio once more. Overall, the time for this step is approximately 4
to 8 hours, and can be monitored either by measuring the amount of
methanol formed in the distillate, or by measuring conversion of
the starting alcohol to the corresponding methacrylate ester in the
pot using either GC or NMR analysis. Once the analytical confirms
that the conversion of the starting alcohol to the ester product is
over 97%, the batch will then be stripped of excess MMA.
[0151] For some combinations of inhibitor with the lithium salt
LiOH, the rate of transesterification is slower, and, at times, an
extra shot of LiOH is needed to complete the reaction. This is
noted by the loss of the azeotrope in the overhead (i.e.,
temperature will not drop to the target 56.degree. C. to 58.degree.
C. range) along with conversion not reaching >97% in the batch.
In these instances, an additional 0.24 grams (0.01 mole) of LiOH is
added to the batch to aid in further conversion. This action
typically leads to continued removal of azeotrope as described
above.
[0152] Removal of Excess MMA:
[0153] Once the alcohol conversion is over 97%, the batch is cooled
to below 50.degree. C., and the overhead column is replaced with a
straight lead distillation tower. Earlier conditions are maintained
for 8% oxygen in nitrogen gas flow, agitator speed, and condenser
temperature. Vacuum is applied to bring the overhead pressure down
to less than or equal to 200 mmHg. Once this pressure is attained,
the batch is heated to 70.degree. C. to begin distilling MMA. A
good distillation rate is maintained by reducing the system
pressure and increasing the batch temperature gradually. The
distillation rate is maintained such that the distillation is
complete within 1 to 4 hours, more preferably 1 to 3 hours, most
preferably 1 to 2 hours. To accomplish this, the pressure is
decreased, over about one hour, to 30 mmHg, while also increasing
temperature over this time to 90.degree. C. If possible to lower
the pressure further, this should be accomplished over an
additional 15 to 30 minutes, while maintaining a batch temperature
of 88.degree. C. to 92.degree. C. When no more MMA appears to be
coming overhead, after reaching less than 30 mmHg and 90.degree. C.
in the batch, a sample is withdrawn from the reaction mixture to
measure for residual MMA by chromatography. Once the MMA is below
0.5 weight %, the vacuum is broken with air, and the batch is
cooled to ambient temperature. If the MMA level is above 0.5 weight
%, then the batch is further held at less than 30 mmHg and also
90.degree. C., for another hour, before checking the MMA level
again.
[0154] Lithium Salt Removal:
[0155] Once the batch begins cooling, after the MMA strip step, the
temperature of the batch is brought down to 0.degree. C. to
5.degree. C. At this temperature, nearly all of the lithium salt
precipitates from the batch. While maintaining the temperature at
0.degree. C. to 5.degree. C., the batch is filtered through a 1
micron sized filter. This gives a clear PPG AEMA monomer product
that is light yellow to light brown in color. Total weight of the
monomer is 533 grams for a 99.5% yield of liquid product that is
over 95% pure.
Examples 2 to 5
[0156] Examples 2 to 5 are prepared as described above, except
different inhibitors were employed in the various examples as
detailed in Table 1.
[0157] Table 1 illustrates the beneficial effect of certain
inhibitors on conversion versus time, and also on reaction and
product stability. The inhibitor amounts listed in Table 1 are
based on the starting mixture once all charges of all raw materials
are made. Polymer observation is conducted using both methanol and
hexane dilution tests.
TABLE-US-00001 TABLE 1 Effect of Inhibitors on Conversion v. Time
4H- Time Polymer Polymer Observed Ex. MeHQ.sup.1 TEMPO.sup.2
PTZ.sup.3 DEHA.sup.4 to >97% 2.sup.nd Shot Observed during
Extended No. (ppm) (ppm) (ppm) (ppm) Conversion LiOH?.sup.5 after
Rx? Storage Time? 1 590 0 0 0 10 hours Yes No Yes 2 590 28 0 0 4
hours No No No 3 590 0 400 0 12 hours Yes No No 4 590 0 30 0
Polymer -- Yes NA formed after 7 hours 5 590 0 0 164 Polymer -- Yes
NA formed after 1 hour .sup.1MeHQ = methyl ether of hydroquinone
.sup.24H-TEMPO = 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy
radical .sup.3PTZ = phenothiazine .sup.4DEHA = diethylhydroxylamine
.sup.5The 2.sup.nd shot of LiOH is equal to 1/4 of the original
amount of LiOH added to the batch.
[0158] As demonstrated in Table 1, certain combinations of
inhibitors result in more stable monomer products. For experiments
2 and 3, using MeHQ as a primary inhibitor (component B), with some
amount of 4H-TEMPO or PTZ as a secondary inhibitor (component C),
resulted in a monomer product exhibiting no evidence of
polymerization, both immediately following the transesterification
reaction and after extended storage. Notably, Applicants
surprisingly and unexpectedly discovered that the inhibitor
combination of MeHQ and 4H-TEMPO not only resulted in a stable
product, but also showed decreased reaction time (i.e., 4 hours to
reach >97% conversion) compared to using MeHQ alone (i.e. 10
hours to reach >97% conversion) and using MeHQ with PTZ (i.e. 12
hours to reach >97% conversion).
Examples 6 to 11
[0159] Examples 6 to 11 are prepared as described according to the
general procedure above, except that 0.8 grams of the methyl ether
of hydroquinone (MeHQ) and 0.04 grams of 4-hydroxy-TEMPO (4H-TEMPO)
are employed as inhibitors for each of examples 6 to 11 and
different precipitation and filtration temperatures are used as
outlined in Table 2.
[0160] Table 2 shows the beneficial effect of lower temperatures on
lithium salt removal.
TABLE-US-00002 TABLE 2 Effect of Precipitation/Filtration
Temperature on Lithium Salt Removal Filtration Appearance
Appearance 30 Appearance 24 Appearance 72 Appearance 60 Ex.
Temperature upon minutes after hours after hours after days after
No. (.degree. C.) Filtration Filtration Filtration Filtration
Filtration 6 20 Slight haze Hazy Hazy Hazy Hazy 7 15 Clear Hazy
Hazy Hazy Hazy 8 10 Clear Clear Hazy Hazy Hazy 9 5 Clear Clear
Clear Hazy Hazy 10 2 Clear Clear Clear Clear Clear 11 0 Clear Clear
Clear Clear Clear .sup.1 After 3 days, the precipitate that causes
haze collects at the bottom of the container. After 60 days of
standing, the samples appear clear with solids collected on the
bottom of the container. However, once the samples are shaken, they
again become hazy. The designation of "hazy" for storage times of
60 days is therefore after shaking.
[0161] As demonstrated in Table 2, only those experiments filtered
at a temperature of less than or equal to 5.degree. C. resulted in
a final monomer composition that remained clear and free of haze
for more than 24 hours. Those examples filtered at a temperature of
less than or equal to 2.degree. C. remained clear and free of haze
for over 6 months. By lowing the filtration temperature to less
than, or equal to, 5.degree. C., or less than, or equal to,
2.degree. C., it was possible to remove the lithium salt to an
acceptable level, without requiring additives and/or filtration
aids. Elimination of these additives results in lower costs for
disposal and more environmentally friendly procedures (i.e., less
waste). In contrast, all solutions filtered at temperatures greater
than 5.degree. C. showed evidence of haze after relatively short
times (i.e., within 24 hours).
Examples 12 to 20--Low Density Polyene Batch Reactor Process
Stability Studies
[0162] Conventional low density polyethylene (LDPE) has good
processability; however, when used in film and/or extrusion coating
application, increased melt strength is still desired. It has been
discovered that such polymers can be produced using asymmetrical
polyenes, such as those described herein. However, there is a need
to produce such polymers under polymerization conditions with good
reactor stability.
[0163] It is well known in the industry that under sufficiently
high pressures and temperatures or in the presence of an ignition
source, ethylene can decompose into carbon, methane and hydrogen.
The following mechanism is described by Zimmermann T. and Luft G.
in "Explosive decomposition of compressed ethylene", Chemie
Ingenieur Technik (1994), 66 (10), 1386-1389:
C.sub.2H.sub.4.fwdarw.(1+z)C+(1-z)CH.sub.4+2zH.sub.2
wherein z is in the range from 0 to 1, and depends on the pressure
and temperature. This results in a runaway reaction, which results
in very high temperatures and pressures which could then lead to
equipment damage. Decomposition of ethylene has been studied
extensively by Luft and others, as reported in "Safety engineering
studies on the explosive decomposition of compressed ethylene",
Chemie Ingenieur Technik (1995), 67 (7), 862-864, "Thermal
decomposition of Ethylene-comonomer mixtures under high pressure"
AIChE Journal (1999), 45 (10), 2214-2222, and "Effect of reactor
contamination on highly compressed ethylene" Chemie Ingenieur
Technik (2000), 72(12), 1538-1541. Zhang et al. have also described
the phenomena in "Runaway phenomena in low-density polyethylene
autoclave reactors" AIChE Journal (1996), 42 (10), 2911-2925.
[0164] Every new compound introduced in LDPE manufacturing
technology which can provide additional radicals over those from
peroxides, and therefore provide the temperature needed for the
runaway reaction, represented by the above mechanism, is ideally
tested for decomposition sensitivity. The propensity for each
compound to shift the baseline level of radicals in the process
must be considered. In some cases, a given compound may generate
radicals independent of other materials injected into the reactor.
In other cases, an interaction between two compounds may generate
additional radicals.
[0165] For the LDPE batch reactor process stability studies, the
set-up described by Alberts et al., "Thermal decomposition of
Ethylene-comonomer mixtures under high pressure" AIChE Journal
(1999), 45 (10), 2214-2222, is used. This set-up is designed for
the study of reaction runaways. The volume of the autoclave reactor
(or cell) is 215 ml. The wall temperature is controlled by electric
heating outside the cell to achieve a starting temperature of
250.degree. C. for the experiments. The cell is designed without an
agitator to prevent any damage to the motor due to the high
temperature and pressures generated during the runaway reaction.
The absence of the mixing and the batch mode of operation are
believed to provide a more conservative (extreme case)
representation of the behavior in a low density polyethylene
tubular reactor.
[0166] The following procedure is applied to test the reaction
runaway potential of the various stability experiments: (1) the
autoclave is purged with ethylene and heated to the starting
temperature; (2) the autoclave is pressurized with ethylene to
about 1400 bar; (3) ditertiarybutyl peroxide (DTBP) and enough
propylene glycol allyl ether methacrylate (PPGAEM) to achieve 100
mol ppm in ethylene once injected into the reactor are mixed
together in a feed vessel and then purged with nitrogen to remove
oxygen; (4) if necessary, heptane is added as a solvent to ensure
the injected volume in all cases is 1 ml; (5) the mixture is added
into injection tubing at the entrance to the reactor; and (5)
ethylene is allowed to flow into the reactor to push the contents
of the injection tubing into the reactor and to pressurize the
reactor up to 1900 bar.
[0167] Table 3 shows the corresponding amount of DTBP and 4-HT used
for the experiment, as well as the amount of active oxygen due to
peroxides in the base alcohol (the alcohol used to produce the
PPGAEM). The amount of 4-HT in ethylene was based on the weight
fraction of 4-HT in the PPGAEM determined from the mass balance
when producing the PPGAEM. The temperature of the reactor 30
seconds after injection of the reaction components (T @ 30 s) was
recorded, and the results are included for each experiment.
[0168] Experiments 12 to 15 illustrate that T@ 30 s rises as the
amount of 4-HT is increased when using the same amount of DTBP.
Experiment 16 and Experiment 17 illustrate at the same
concentration of DTBP, the T @ 30 s was lower for the experiment
with the PPGAEM produced from the base alcohol which had a much
lower amount of active oxygen due to peroxides. Examples 16 to 20
illustrate it was possible to use higher amounts of DTBP for the
experiments with the PPGAEM produced from the base alcohol, which
had a much lower amount of active oxygen due to peroxides. As a
whole, Experiments 12 to 20 illustrate an improved capability to
avoid reactive runaway decomposition reactions through a higher
degree of control over radicals or compounds, which can initiate
polymerization of ethylene in the high pressure low density
polymerization process, when minimizing the 4-HT and the peroxides
in the base alcohol used to produce the PPGAEM.
TABLE-US-00003 TABLE 3 Low Density Polyethylene Batch Reactor
Process Stability Studies Peroxide in Mol ppm Weight ppm Base
Alcohol T @ Mol ppm Ex. PPGAEM in 4-HT in (active oxygen 30 s DTBP
in No. Ethylene Ethylene ppm by weight) (.degree. C.) Ethylene 12
100 0 1000 290 2 13 100 457 1000 300 2 14 100 75 1000 296 2 15 100
75 1000 296 2 16 100 75 1000 299 2.2 17 100 75 1000 309 2.3 18 100
72 4 297 2.3 19 100 72 4 297 2.4 20 100 72 4 308 2.6
* * * * *