U.S. patent application number 14/663722 was filed with the patent office on 2015-07-09 for electron deficient olefins.
The applicant listed for this patent is Henkel IP & Holding GmbH. Invention is credited to Stefano L. Gherardi, Ciaran McArdle, Kevin D. Murnaghan, Ligang Zhao.
Application Number | 20150191424 14/663722 |
Document ID | / |
Family ID | 40347783 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150191424 |
Kind Code |
A1 |
McArdle; Ciaran ; et
al. |
July 9, 2015 |
ELECTRON DEFICIENT OLEFINS
Abstract
This invention relates to novel electron deficient olefins, such
as certain 2-cyanoacrylates and methylidene malonates, prepared
using an imine or an iminium salt.
Inventors: |
McArdle; Ciaran; (Dublin,
IE) ; Zhao; Ligang; (Duesseldorf, DE) ;
Gherardi; Stefano L.; (Dublin, IE) ; Murnaghan; Kevin
D.; (Duesseldorf, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Henkel IP & Holding GmbH |
Duesseldorf |
|
DE |
|
|
Family ID: |
40347783 |
Appl. No.: |
14/663722 |
Filed: |
March 20, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12766457 |
Apr 23, 2010 |
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14663722 |
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PCT/EP2008/064490 |
Oct 24, 2008 |
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12766457 |
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60982157 |
Oct 24, 2007 |
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Current U.S.
Class: |
524/850 ;
524/854; 558/305; 558/442; 560/181 |
Current CPC
Class: |
C07C 69/593 20130101;
C08K 5/13 20130101; C07C 255/23 20130101; C07C 69/73 20130101; C07C
255/19 20130101; C07C 255/15 20130101; C08F 222/30 20130101; C07C
255/17 20130101; C08F 222/14 20130101 |
International
Class: |
C07C 255/19 20060101
C07C255/19; C08F 222/30 20060101 C08F222/30; C08F 222/14 20060101
C08F222/14; C07C 69/593 20060101 C07C069/593 |
Claims
1. Compounds according to claim 1, selected from the group
consisting of ##STR00046##
2. A composition comprising: (a) one or more compounds of claim 1;
(b) a stabilizer package comprising at least one of a free radical
stabilizer and an anionic stabilizer; and (c) optionally, one or
more additives selected from the group consisting of cure
accelerators, thickeners, thixotropes, tougheners, thermal
resistance-conferring agents, and plasticizers.
3. The composition of claim 10, further comprising a
coreactant.
4. The composition of claim 11, wherein the coreactant is a member
selected from the group consisting of epoxides, episulfides,
oxetanes, thioxetanes, dioxolanes, dioxanes, isocyanates,
maleimides, oxazolines, (meth)acrylates, acrylamides,
cyanoacrylates, methylidene malonates, and vinyl ethers.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to novel electron deficient olefins,
such as certain 2-cyanoacrylates or methylidene malonates, prepared
using an imine or an iminium salt.
[0003] 2. Brief Description of Related Technology
[0004] Cyanoacrylate adhesives are known for their fast adhesion
and ability to bond a wide variety of substrates. They are marketed
as "super glue" type adhesives. They are useful as an all-purpose
adhesive since they are a single component adhesive, very
economical as only a small amount will do, and generally do not
require any equipment to effectuate curing.
[0005] Traditionally, cyanoacrylate monomers have been produced by
way of a Knoevenagel condensation reaction between a formaldehyde
precursor, such as paraformaldehyde, and an alkyl cyanoacetate with
a basic catalyst. During the reaction, cyanoacrylate monomer forms
and polymerises in situ to a prepolymer. The prepolymer is
subsequently thermally cracked or depolymerised, yielding
cyanoacrylate monomer. This approach has remained essentially the
same over time, though various improvements and variants have been
introduced. See e.g. U.S. Pat. Nos. 6,245,933, 5,624,699,
4,364,876, 2,721,858, 2,763,677 and 2,756,251.
[0006] In U.S. Pat. No. 3,142,698, the synthesis of difunctional
cyanoacrylates using a Knoevenagel condensation reaction is
described. However, the ability to thermally depolymerise the
resulting, now crosslinked, prepolymer in a reliable and
reproducible manner to produce pure difunctional monomers in high
yields is questionable [see J. Buck, J. Polym. Sci., Polym. Chem.
Ed., 16, 2475-2507 (1978), and U.S. Pat. Nos. 3,975,422, 3,903,055,
4,003,942, 4,012,402, and 4,013,703].
[0007] A variety of other processes for producing cyanoacrylate
monomers are known, some of which are described below. For
instance, U.S. Pat. No. 5,703,267 defines a process for producing a
2-cyanoacrylic acid which comprises subjecting a 2-cyanoacrylate
and an organic acid to a transesterification reaction.
[0008] U.S. Pat. No. 5,455,369 defines an improvement in a process
for preparing methyl cyanoacrylate, in which methyl cyanoacetate is
reacted with formaldehyde to form a polymer that is then
depolymerized to the monomeric product, and in which the purity of
yield is 96% or better. The improvement of the '369 patent is
reported to be conducting the process in a poly(ethylene glycol)
diacetate, dipropionate, or dibutyrate, having a number average
molecular weight of 200-400, as the solvent.
[0009] U.S. Pat. No. 6,096,848 defines a process for the production
of a biscyanoacrylate, which comprises the steps of esterifying a
2-cyanoacrylic acid or transesterifying an alkyl ester thereof to
obtain a reaction mixture; and fractionally crystallizing the
reaction mixture to obtain the biscyanoacrylate.
[0010] U.S. Pat. No. 4,587,059 defines a process for the
preparation of monomeric 2-cyanoacrylates comprising the steps of
(a) reacting (i) a 2,4-dicyanoglutarate with (ii) formaldehyde,
cyclic or linear polymers of formaldehyde, or a mixture thereof, in
the presence of between about 0.5 and about 5 mols of water per mol
of 2,4-dicyanoglutarate, at an acid pH of about 3 to slightly less
than 7, and at a temperature of about 70 to about 140, to form an
oligomeric intermediate product, and (b) removing water that is
present from step (a) and thermolyzing the oligomeric intermediate
product for a period of time sufficient to effect its conversion to
monomeric 2-cyanoacrylates.
[0011] Commercial production of cyanoacrylate monomers ordinarily
relies on the depolymerisation of a prepolymer formed under
Knoevenagel condensation reaction conditions, as noted above. Still
today the Knoevenagel condensation reaction is believed to remain
the most efficient and prevalent commercial method for producing
high yields of monofunctional cyanoacrylates. Nevertheless, it
would be desirable to not have to resort to thermally induced
depolymerisation of a prepolymer produced by the Knoevenagel
condensation reaction. This prospect may also enable facile access
to highly useful difunctional monomers, such as so-called
biscyanaocrylates or hybrid materials of cyanoacrylate and other
polymerisable or reactive functionality.
[0012] For instance, cyanoacrylate esters bearing moisture, base,
acid, thermally sensitive or otherwise reactive moieties, may not
be conveniently produced and isolated under Knoevenagel reaction
conditions.
[0013] While methods describing the preparation of cyanoacrylates
with reactive functionality in the ester side chain (such as
biscyanoacrylates) are known (see e.g. Buck and U.S. Pat. Nos.
3,975,422, 3,903,055, 4,003,942, 4,012,402, and 4,013,703), the
cyanoacrylates with reactive functionality in the ester side chain
are prepared in a multi-step process involving protective group
strategies and functional group transformations to arrive at
adducts which must subsequently be deprotected to yield
cyanoacrylates with additional functionality. The same approach has
been described to arrive at a cyanoacrylate-capped polyisobutylene
by Kennedy et al., J. Macromol Sci. Chem., A28, 209 (1991).
[0014] A transesterification approach to achieve cyanoacrylates
with reactive functions in the ester side chain has also been
described in U.S. Pat. No. 6,096,848, in which cyanoacrylate
esters, previously made by Knoevenagel reaction, are hydrolysed in
strong acid conditions in the presence of a difunctional alcohol to
yield biscyanoacrylates. The method described in the '848 patent
requires long reaction times, copious volumes of solvent and
solvent switching methods to isolate the bifunctional
cyanoacrylates free from acid stablisers in modest to low yields
[see also Khrustalev et al., Russian Chem. Bull., 45, 9, 2172
(1996)].
[0015] An alternative approach to the preparation of cyanoacrylates
with reactive functions in the ester side chain uses cyanoacrylic
acid or its acid chloride (cyanoacryloyl chloride). See e.g.
International Patent Publication Nos. WO 94/15590A1, WO
94/115907A1, and WO 95/32183A1, and U.S. Pat. No. 5,703,267.
[0016] The use of cyanoacrylic acid and cyanoacryloyl chloride to
arrive at cyanoacrylates has also been described in Y. Gololobov
and I. Chernoglazova, Russian Chem. Bull., 42, 5, 961 (1993) and Y.
Gololobov and M. Galkina, Russian Chem. Bull., 44, 4, 760 (1995).
These methods require flash vacuum pyrolysis techniques conducted
in quartz tubes at high temperatures (approximately 600.degree. C.)
and exposure of highly reactive, polymerisable intermediate
materials to chemical reactions with highly acidic and moisture
sensitive reagents.
[0017] With regard to the preparation of other types of electron
deficient olefins with reactive functionality, U.S. Pat. No.
5,142,098 describes a copper catalysed reaction of malonates and
formaldehyde to form methylidenemalonate monomers that are trapped
in situ by a "diene" anthracene in a Diels-Alder reaction. The '098
patent describes a diester adduct of anthracene, that is a
precursor for a methylidenemalonate monomer with one ethyl ester
and one glycidyl ester. The '098 patent indicates that reaction--a
retro Diels-Alder thermolysis step--was not successful for the
preparation of the particular methylidene malonate bearing the
glycidyl functionality in the ester side chain. The retro
Diels-Alder reaction has been reported as useful in the syntheses
of other methylidene malonates (see e.g. J-L. De Keyser et al., J.
Org. Chem., 53, 4859 (1988)).
[0018] Accordingly, it will be appreciated that the preparation of
electron deficient olefins, such as 2-cyanoacrylates or methylidene
malonates, with a reactive functional group in the ester, or even
with large or bulky groups in the ester side chain, is not a
trivial matter.
[0019] As a result and because of the limitations of the hitherto
known various processes for cyanoacrylate synthesis and the
sensitivity of the novel electron deficient olefins, such novel
electron deficient olefins have not been described to date. Until
now.
SUMMARY OF THE INVENTION
[0020] Unlike the state of the technology, the present invention
provides novel electron deficient olefins, such as 2-cyanoacrylates
or methylidene malonates, with a reactive functional group in the
ester side chain, prepared using an imine or an iminium salt.
[0021] The novel compounds are electron deficient olefins within
structure I:
##STR00001## [0022] where X is (a) an electron withdrawing group,
or (b) Y; [0023] Y is
[0023] ##STR00002## [0024] where D is selected from H, alkyl or
aryl, Z is either [0025] (i)
[0025] ##STR00003## [0026] where Q is [0027] a. an electron
withdrawing group (such as CN, CO.sub.2R, CO.sub.2H, COCl, COR,
COPO(OR).sub.2, COPOR.sub.2, SO.sub.2R, SO.sub.3R or NO.sub.2) or
[0028] b. a first reactive functionality, or [0029] (ii) a second
reactive functionality, g is 1-10; and [0030] n is 0 or 1.
Desirably, g is 1. However, if g>1, D should be H.
[0031] More specifically, the inventive compounds are embraced by
structure II
##STR00004##
[0032] where X is an electron withdrawing group or E, E is as
shown,
##STR00005##
[0033] is a reactive functionality, D is selected from H, alkyl or
aryl, n is 0 or 1, and A, B, 1, 2, 3, 4, 5, and 6 are each
references to bond designations.
[0034] In an alternative aspect the inventive compounds are
embraced by structure III
##STR00006##
[0035] where X is an electron withdrawing group or F, D is selected
from H, alkyl or aryl, Z is a reactive functionality, n is 0 or 1
and g is 1. The reactive functionality of Z in structure III may be
selected from epoxides, episulfides, oxetanes, thioxetanes,
dioxolanes, dioxanes, isocyanates, maleimides, oxazolines,
succinimides, 2-cyanoacrylates, methylidene malonates,
acrylonitrile, (meth)acrylates, carboxylic acids and derivatives
thereof, cyanoacetates, methylene malonates, hydroxyls, silanes,
siloxanes, titanates, or zirconates.
[0036] The present invention also provides compositions of the
compounds of structures I, together with a stabilizer package
comprising at least one of a free radical stabilizer and an anionic
stabilizer; and optionally, one or more additives selected from
cure accelerators, thickeners, thixotropes, tougheners, thermal
resistance-conferring agents, or plasticizers.
[0037] The present invention further provides compositions of the
compounds of structures I, II or III, together with a cyanoacrylate
or a methylidene malonate. Or the present invention further
provides compositions of certain of the compounds of structures I,
II or III, together with a coreactant, such as one selected from
epoxides, episulfides, oxetanes, thioxetanes, dioxolanes, dioxanes,
isocyanates, maleimides, oxazolines, (meth)acrylates,
cyanoacrylates, methylidene malonates or vinyl ethers.
BRIEF DESCRIPTION OF THE FIGURES
[0038] FIG. 1 depicts a synthetic scheme by which iminium salts may
be prepared.
[0039] FIG. 2 depicts a synthetic scheme by which a precursor to an
inventive electron deficient olefin may be prepared.
[0040] FIG. 3 depicts a synthetic scheme by which the precursor to
an inventive electron deficient olefin (from FIG. 2) is used with
the iminium salt (from FIG. 1) to form the inventive electron
deficient olefin.
DETAILED DESCRIPTION OF THE INVENTION
[0041] As noted above, the present invention provides electron
deficient olefins within structure I:
##STR00007## [0042] where X is (a) an electron withdrawing group,
or (b) Y; [0043] Y is
[0043] ##STR00008## [0044] where D is selected from H, alkyl (such
as one to twenty carbon atoms) or aryl (such as six to twenty
carbon atoms), [0045] Z is either [0046] (i)
[0046] ##STR00009## [0047] where Q is [0048] a. an electron
withdrawing group (such as CN, CO.sub.2R, CO.sub.2H, COCl, COR,
COPO(OR).sub.2, COPOR.sub.2, SO.sub.2R, SO.sub.3R or NO.sub.2) or
[0049] b. a first reactive functionality, or [0050] (ii) a second
reactive functionality, g is 1-10; and [0051] n is 0 or 1.
Desirably, g is 1. However, if g>1, D should be H.
[0052] More specifically, the inventive compounds are embraced by
structure II
##STR00010##
where X is an electron withdrawing group (such as CN, CO.sub.2R,
CO.sub.2H, COCl, COR, COPO(OR).sub.2, COPOR.sub.2, SO.sub.2R,
SO.sub.3R or NO.sub.2, where R is C.sub.1-4) or E, E is as
shown,
##STR00011##
is a reactive functionality, D is selected from H, alkyl or aryl, n
is 0 or 1, and A, B, 1, 2, 3, 4, 5, and 6 are each references to
bond designations. Q may be an amide or thioamide embraced by
C(T)NUV,
where T is O or S and U or V are each independently selected from H
or R, where R is C.sub.1-4. In addition, in structure II, the vinyl
group labeled `6` is disposed 6 bond lengths distance from the
vinyl group labeled `1`, ignoring side branches and where Q is not
H.
[0053] In an alternative aspect the inventive compounds are
embraced by structure III
##STR00012##
where X is an electron withdrawing group (such as CN, CO.sub.2R,
CO.sub.2H, COCl, COR, COPO(OR).sub.2, COPOR.sub.2, SO.sub.2R,
SO.sub.3R or NO.sub.2, where R is C.sub.1-4) or F, D is selected
from H, alkyl (such as one to twenty carbon atoms) or aryl (such as
six to twenty carbon atoms), Z is a reactive functionality, n is 0
or 1 and g is 1. The reactive functionality of Z in structure III
may be selected from epoxides, episulfides, oxetanes, thioxetanes,
dioxolanes, dioxanes, isocyanates, maleimides, oxazolines,
succinimides, 2-cyanoacrylates, methylidene malonates,
acrylonitrile, (meth)acrylates, carboxylic acids and derivatives
thereof, cyanoacetates, methylene malonates, hydroxyls, silanes,
siloxanes, titanates, or zirconates.
[0054] Representative examples of novel electron deficient olefins
within the scope of the invention include
##STR00013##
[0055] To prepare such compounds in accordance with the present
invention, one may use imines embraced by structure VI or iminium
salts embraced by structure VII.
[0056] The imine embraced within structure VI is as follows:
##STR00014##
where K is
##STR00015##
[0057] where in this connection R.sub.1-R.sub.2 are each
independently selected from hydrogen, alkenyl (such as two to
twenty carbon atoms), or alkynyl (such as two to twenty carbon
atoms); and A-B are each independently selected from linear,
branched, or cyclic alkyl (such as three to twenty carbon atoms) or
alkenyl (such as three to twenty carbon atoms) which may be
interrupted with heteroatoms or substituted by functional groups,
or A and B taken together form a cyclic or polycyclic alkyl or
alkenyl structure, which may be interrupted with heteroatoms or
substituted by functional groups;
[0058] E is selected from a linear, branched or cyclic hydrocarbon
with or without one or more nitrogen-containing substituents
thereon, a heterocyclic, an aromatic or an organosiloxane group or
part thereof or linkage; and
[0059] R.sub.3 in this connection is selected from a hydrocarbon, a
heterocyclic, an aromatic or an organosiloxane group or
linkage;
[0060] w is 1-100; y is 1-100 and z is 0-100.
When more than one of K, E or R.sub.3 are present, each instance
thereof is defined independently from the other instance(s).
[0061] The imine more specifically is embraced within structure VIA
as follows:
##STR00016##
where in this connection R.sub.1-R.sub.2, A-B, E, R.sub.3, w, y and
z are as defined above.
[0062] The iminium salt embraced within structure VII is as
follows:
##STR00017##
where K is
##STR00018##
[0063] where in this connection R.sub.1-R.sub.2 are each
independently selected from hydrogen, alkenyl, or alkynyl; and A-B
are each independently selected from linear, branched, or cyclic
alkyl or alkenyl which may be interrupted with heteroatoms or
substituted by functional groups, or A and B taken together form a
cyclic or polycyclic alkyl or alkenyl structure, which may be
interrupted with heteroatoms or substituted by functional
groups;
[0064] E is selected from a linear, branched or cyclic hydrocarbon
with or without one or more nitrogen-containing substituents
thereon, a heterocyclic, an aromatic or an organosiloxane group or
part thereof or linkage; and
[0065] R.sub.3 in this connection is selected from a hydrocarbon, a
heterocyclic, an aromatic or an organosiloxane group or
linkage;
[0066] w is 1-100; y is 1-100 and z is 0-100; and
[0067] X is an anion.
When more than one of K, E or R.sub.3 are present, each instance
thereof is defined independently from the other instance(s).
[0068] The iminium salt is embraced more specifically by structure
VIIA as follows:
##STR00019##
where in this connection R.sub.1-R.sub.2, A-B, E, R.sub.3, w, y and
z, and X are as defined above.
[0069] The imine in some cases may be an imine having an onium
salt, such as an ammonium or amine salt functionality. In some
cases the imines may be termed an "ionic liquid" (or "IL") or a
task specific ionic liquid (or, "TSIL"), as will be discussed in
more detail below. Likewise, the iminium salts may be termed an
"ionic liquid" (or "IL") or a task specific ionic liquid (or,
"TSIL"), as will be discussed in more detail below.
[0070] In such cases where the imine of structure VI or the iminium
salt of structure VII is particularly stable at room temperature
conditions when in the presence of the precursor to the electron
deficient olefin, a modest amount of heat may be useful to allow
the reaction to generate electron deficient olefins. Exposure to
elevated temperature conditions is particularly desirable with
iminium salts of structure VII.
[0071] Reference to the figures may be useful to appreciate further
how electron deficient olefins of the present invention are
prepared, which is described in more detail below and in the
Examples section that follows thereafter.
[0072] Thus, as an initial reactant, is an aldehyde compound having
the structure R.sub.3R.sub.4C.dbd.O, where R.sub.3 is hydrogen and
R.sub.4 is a hydrogen, vinyl or propargyl. The aldehyde compound
may be an aldehyde itself or a source of an aldehyde, such as one
that yields an aldehyde like formaldehyde under appropriate
reaction conditions. The aldehyde compound in a desirable
embodiment includes formaldehyde or a source thereof, such as
paraformaldehyde (see FIG. 1), formalin, or 1,3,5-trioxane, or
vinyl aldehydes, such as acrolein.
[0073] As a reactant with such an aldehyde is a primary amine.
Primary amines attached to a carbon bearing no alpha protons are
particularly desirable, such as t-alkyl primary amines. Rohm and
Haas Co., Philadelphia, Pa. has sold commercially for a number of
years a series of t-alkyl primary amines, which are designated as
PRIMENE-brand amines.
[0074] For instance, t-alkyl primary amines available from Rohm and
Haas include PRIMENE 81-R and PRIMENE JM-T. These PRIMENE-brand
t-alkyl primary amines have highly branched alkyl chains
(represented schematically by circle symbols in the Figures for
simplicity) in which the amino nitrogen atom is attached directly
to a tertiary carbon. These t-alkyl primary amines consist of
mixtures of isomeric amines, with PRIMENE 81-R consisting of an
isomeric mixture with C.sub.12-C.sub.14 carbon branches and having
an average molecular weight of 185 and PRIMENE JM-T consisting of
an isomeric mixture with C.sub.16-C.sub.22 carbon branches and
having average molecular weight of 269.
[0075] PRIMENE MD, also known as menthanediamine
(1,8-diamino-p-menthane) or
(4-amino-.alpha.,.alpha.-4-trimethyl-cyclohexanemethanamine, CAS
No. 80-52-4), is a primary alicyclic diamine, in which both amino
groups are attached to tertiary carbon atoms. Like other alicyclic
t-alkyl primary amines, menthanediamine is somewhat less reactive
than similar straight chain diamines. Yet another PRIMENE, PRIMENE
TOA has tertiary octyl chains and a molecular weight of 129. In the
examples given below, PRIMENE 81-R MSA iminium salt, formed in
reaction (2) of FIG. 1, is used.
[0076] The imines, whether or not bearing ammonium salt
functionality or whether or not they are tethered to a support, are
then reacted with compounds containing a methylene linkage having
at least one, desirably two, electron withdrawing substituent(s)
attached thereto. The preparation of a methylene compound useful as
a precursor to an electron deficient olefin is depicted in FIG. 2,
which illustrates the esterification of cyanoacetic acid with alpha
hydroxymethyl acrylate. In these compounds, the electron
withdrawing substituent is selected from nitrile, carboxylic acids,
carboxylic esters, sulphonic or suphinic acids or their esters,
ketones, phosphocarbonyl, or nitro. Such compounds are reacted with
iminium salts for example as depicted in FIG. 3 to form novel
electron deficient olefins. In a desirable embodiment, these
compounds have two or more electron withdrawing substituents, which
may be the same or different, such as nitrile and carboxylic acid
ester--in this case, a cyanoacrylate. Of course, the reactivity of
these compounds in large part depends on the degree of electron
withdrawing capability of the particular substituent, and the
number of substituents on the active methylene carbon.
[0077] The reaction to form the novel electron deficient olefins
may proceed with or without heating or cooling, depending of course
on the specific reactants and the scale of the reaction.
Decomposition of the source of formaldehyde, e.g.,
paraformaldehyde, may occur under gentle heating up to a
temperature of about 70.degree. C., to liberate formaldehyde in
situ in the reaction medium. The temperature may be reached through
an external heating element or internally by means of the exotherm
that may be generated, depending of course on the identity of the
reactants. The temperature of the reaction should be controlled
however to accommodate any such exothermic processes.
[0078] The time of reaction may be monitored by reference to the
formation of the desired novel electron deficient olefin product. A
.sup.1H NMR spectrometer is a particularly useful tool in this
regard. The time of reaction may be as little as 1 minute, for
instance, or longer or shorter for that matter depending again on
the identity of the specific reactants, the scale of the reaction
and whether heat is introduced to or removed from the reaction
conditions.
[0079] Once formed, the novel electron deficient olefin may be
isolated by direct distillation under vacuum out of the reaction
mixture or by freezing it in a solid form and separating off the
liquid phase.
[0080] The novel electron deficient olefin may be stabilized during
the synthesis and/or isolation procedure, and also in the isolated
product to improve its shelf life. Suitable stabilizers include
stabilizer packages that may contain one or more of free radical
stabilizers and acidic stabilizers.
[0081] For example, free radical stabilizers include hydroquinone,
pyrocatechol, resorcinol or derivatives thereof, such as
hydroquinone monoethyl ether, or phenols, such as di-t-butylphenol
or 2,6-di-t-butyl-p-cresol,
2,2'-methylene-bis-(4-methyl-6-t-butylphenol), bisphenol A,
dihydroxydiphenylmethane, and styrenized phenols.
[0082] For example, acidic stabilizers include sulfuric acid,
hydrochloric acid, sulfonic acids, such as methane, ethane or
higher sulfonic acids, p-toluene sulfonic acid, phosphoric acid or
polyphosphoric acids, silyl esters of strong acids, such as
trialkyl chlorosilanes, dialkyl dichlorosilanes, alkyl
trichlorosilanes, tetrachlorosilane, trialkyl silylsulfonic acids,
trialkyl silyl-p-toluene sulfonates, bis-trialkyl silylsulfate and
trialkyl silylphosphoric acid esters.
[0083] The amount of either stabilizer used to stabilize the
electron deficient olefin prepared by the inventive processes is
well known to those of ordinary skill in the art, and may be varied
depending on the properties of the resulting composition made from
the so formed electron deficient olefin.
[0084] The present invention also provides compositions of the
compounds of structures I, II or III, together with a stabilizer
package comprising at least one of a free radical stabilizer and an
anionic stabilizer; and optionally, one or more additives selected
from cure accelerators, thickeners, thixotropes, tougheners,
thermal resistance-conferring agents, or plasticizers.
[0085] The cure accelerators that may be included with the
inventive electron deficient olefins to form inventive compositions
include calixarenes and oxacalixarenes, silacrowns, crown ethers,
cyclodextrins, poly(ethyleneglycol) di(meth)acrylates, ethoxylated
hydric compounds and combinations thereof.
[0086] Of the calixarenes and oxacalixarenes, many are known, and
are reported in the patent literature. See e.g. U.S. Pat. Nos.
4,556,700, 4,622,414, 4,636,539, 4,695,615, 4,718,966, and
4,855,461, the disclosures of each of which are hereby expressly
incorporated herein by reference.
[0087] For instance, as regards calixarenes, those within the
following structure are useful herein:
##STR00020##
where in this connection R.sup.1 is alkyl, alkoxy, substituted
alkyl or substituted alkoxy; R.sup.2 is H or alkyl; and n is 4, 6
or 8.
[0088] One particularly desirable calixarene is tetrabutyl
tetra[2-ethoxy-2-oxoethoxy]calix-4-arene.
[0089] A host of crown ethers are known. For instance, examples
which may be used herein include 15-crown-5, 18-crown-6,
dibenzo-18-crown-6, benzo-15-crown-5-dibenzo-24-crown-8,
dibenzo-30-crown-10, tribenzo-18-crown-6, asym-dibenzo-22-crown-6,
dibenzo-14-crown-4, dicyclohexyl-18-crown-6,
dicyclohexyl-24-crown-8, cyclohexyl-12-crown-4,
1,2-decalyl-15-crown-5, 1,2-naphtho-15-crown-5,
3,4,5-naphtyl-16-crown-5, 1,2-methyl-benzo-18-crown-6,
1,2-methylbenzo-5, 6-methylbenzo-18-crown-6,
1,2-t-butyl-18-crown-6, 1,2-vinylbenzo-15-crown-5,
1,2-vinylbenzo-18-crown-6, 1,2-t-butyl-cyclohexyl-18-crown-6,
asym-dibenzo-22-crown-6 and
1,2-benzo-1,4-benzo-5-oxygen-20-crown-7. See U.S. Pat. No.
4,837,260 (Sato), the disclosure of which is hereby expressly
incorporated here by reference.
[0090] Of the silacrowns, again many are known, and are reported in
the literature. For instance, a typical silacrown may be
represented within the following structure:
##STR00021##
where in this connection R.sup.3 and R.sup.4 are organo groups
which do not themselves cause polymerization of the cyanoacrylate
monomer, R.sup.5 is H or CH.sub.3 and n is an integer of between 1
and 4. Examples of suitable R.sup.3 and R.sup.4 groups are R
groups, alkoxy groups, such as methoxy, and aryloxy groups, such as
phenoxy. The R.sup.3 and R.sup.4 groups may contain halogen or
other substituents, an example being trifluoropropyl. However,
groups not suitable as R.sup.4 and R.sup.5 groups are basic groups,
such as amino, substituted amino and alkylamino.
[0091] Specific examples of silacrown compounds useful in the
inventive compositions include:
##STR00022##
dimethylsila-11-crown-4;
##STR00023##
dimethylsila-14-crown-5;
##STR00024##
and dimethylsila-17-crown-6. See e.g. U.S. Pat. No. 4,906,317
(Liu), the disclosure of which is hereby expressly incorporated
herein by reference.
[0092] Many cyclodextrins may be used in connection with the
present invention. For instance, those described and claimed in
U.S. Pat. No. 5,312,864 (Went), the disclosure of which is hereby
expressly incorporated herein by reference, as hydroxyl group
derivatives of an .alpha.-, .beta.- or .gamma.-cyclodextrin which
is at least partly soluble in the cyanoacrylate would be
appropriate choices for use herein as the first accelerator
component.
[0093] For instance, poly(ethylene glycol)di(meth)acrylates
suitable for use herein include those within the following
structure:
##STR00025##
where n is greater than 3, such as within the range of 3 to 12,
with n being 9 as particularly desirable. More specific examples
include PEG 200 DMA (where n is about 4), PEG 400 DMA (where n is
about 9), PEG 600 DMA (where n is about 14), and PEG 800 DMA (where
n is about 19), where the number (e.g., 400) represents the average
molecular weight of the glycol portion of the molecule, excluding
the two methacrylate groups, expressed as grams/mole (i.e., 400
g/mol). A particularly desirable PEG DMA is PEG 400 DMA.
[0094] And of the ethoxylated hydric compounds (or ethoxylated
fatty alcohols that may be employed), appropriate ones may be
chosen from those within the following structure:
##STR00026##
where C.sub.m can be a linear or branched alkyl or alkenyl chain, m
is an integer between 1 to 30, such as from 5 to 20, n is an
integer between 2 to 30, such as from 5 to 15, and R in this
connection may be H or alkyl, such as C.sub.1-6 alkyl.
[0095] Commercially available examples of materials within the
above structure include those offered under the DEHYDOL tradename
from Henkel KGaA, Dusseldorf, Germany, such as DEHYDOL 100.
[0096] When used, the cure accelerator should be included in the
compositions in an amount within the range of from about 0.01% to
about 10% by weight, with the range of about 0.1 to about 0.5% by
weight being desirable, and about 0.4% by weight of the total
composition being particularly desirable.
[0097] Other additives may be included with the inventive electron
deficient olefins to form inventive compositions to confer
additional physical properties, such as improved shock resistance,
thickness (for instance, polymethyl methacrylate), thixotropy (for
instance fumed silica), color, and enhanced resistance to thermal
degradation [for instance, maleimide compounds such as
N,N'-meta-phenylene bismaleimide (see U.S. Pat. No. 3,988,299
(Malofsky)), certain mono, poly or hetero aromatic compounds
characterized by at least three substitutions on an aromatic ring
thereof, two or more of which being electron withdrawing groups
(see U.S. Pat. No. 5,288,794 (Attarwala)), certain quinoid
compounds (see U.S. Pat. No. 5,306,752 (Attarwala)), certain
sulfur-containing compounds, such as an anhydrosulfite, a
sulfoxide, a sulfite, a sulfonate, a methanesulfonate or a
p-toluenesulfonate (see U.S. Pat. No. 5,328,944 (Attarwala)), or
certain sulfur-containing compounds, such as a sulfinate, a cyclic
sultinate naphthosultone compound substituted with at least one
strong electron withdrawing group at least as strongly electron
withdrawing as nitro (see U.S. Pat. No. 5,424,343 (Attarwala)), and
alkylating agents such as polyvinyl benzyl chloride, 4-nitrobenzyl
chloride, and combinations thereof, silylating agents, and
combinations thereof (see U.S. Pat. No. 6,093,780 (Attarwala)), the
disclosures of each of which are hereby incorporated herein by
reference. Such additives therefore may be selected from certain
acidic materials (like citric acid), thixotropy or gelling agents,
thickeners, dyes, thermal degradation resistance enhancers, and
combinations thereof. See e.g. U.S. patent application Ser. No.
11/119,703 and U.S. Pat. Nos. 5,306,752, 5,424,344 and 6,835,789,
the disclosures of each of which are hereby incorporated herein by
reference.
[0098] These other additives may be used in the inventive
compositions individually in an amount from about 0.05% to about
20%, such as about 1% to 15%, desirably 5% to 10% by weight,
depending of course on the identity of the additive. For instance,
and more specifically, citric acid may be used in the inventive
compositions in an amount of 5 to 500 ppm, desirably 10 to 100
ppm.
[0099] Of course, the molecular design of the inventive electron
deficient olefins may render it less desirable to include one or
more these additives with the inventive electron deficient olefins
to form inventive compositions.
[0100] The present invention further provides compositions of the
inventive compounds, together with a cyanoacrylate, a methylidene
malonate or combinations thereof.
[0101] More specifically, the cyanoacrylate used in combination
with the inventive compounds is one within structure IV:
##STR00027##
where in this connection R.sup.1 is selected from C.sub.1-16 alkyl,
alkoxyalkyl, cycloalkyl, alkenyl (such as allyl), alkynyl,
arylalkyl, aryl, or haloalkyl groups.
[0102] The cyanoacrylate with structure IV is selected from methyl
cyanoacrylate, ethyl-2-cyanoacrylate, propyl cyanoacrylates, butyl
cyanoacrylates, octyl cyanoacrylates, allyl cyanoacrylate,
i-methoxyethyl cyanoacrylate and combinations thereof.
[0103] The methylidene malonate used in combination with the
inventive compounds is one within structure V:
##STR00028##
where in this connection R.sup.2 and R.sup.3 are each independently
selected from C.sub.1-16 alkyl, alkoxyalkyl, cycloalkyl, alkenyl,
aralkyl, aryl, allyl or haloalkyl groups.
[0104] The present invention further provides compositions of
certain of the compounds of structure I, together with a
coreactant, such as one selected from epoxides (such as
cycloaliphatic epoxies), episulfides, oxetanes, thioxetanes,
dioxolanes, dioxanes, isocyanates, maleimides, oxazolines,
(meth)acrylates, acrylamides, cyanoacrylates, methylidene malonates
or vinyl ethers. Particularly desirable compounds within structure
I for this purpose include
##STR00029##
[0105] The following examples are intended to illustrate but in no
way limit the present invention.
EXAMPLES
Example 1
[0106] PRIMENE 81-R imine was prepared by reaction of PRIMENE 81-R
amine with a stoichiometric equivalent of paraformaldehyde and
removal of water of condensation. All imines formed were
distillable liquids and existed in stable monomeric imine forms as
confirmed by .sup.1H NMR 60 MHz (CDCl.sub.3) 2H s (br) 7.45 ppm and
FTIR (1650 cm.sup.-1).
Example 2
[0107] PRIMENE 81-R iminium-MSA was prepared from PRIMENE 81-R
imine by adding dropwise with stirring methane sulfonic acid at ice
water bath temperature, yielding a pale yellow iminium salt.
Example 3
##STR00030##
[0109] To a stirring mixture of cyanoacetic acid (90 g, 1.05 mol),
ethyl 2-hydroxylmethyl acrylate (130 g, 1.0 mol), p-toluene
sulfonic acid (500 mg) and hydroquinone (200 mg), was added toluene
(150 mL), and the mixture was refluxed at a temperature of
150.degree. C. to azeotropically remove water.
[0110] After cooling, the reaction product was washed consecutively
with 30% brine and water. The organic layer was dried over
anhydrous sodium sulfate, filtered and the solvent removed by
rotary evaporator. The crude reaction product was purified by
vacuum distillation (120-126.degree. C./0.2 mbar), with the ester
of structure A (102 g, 0.52 mol) isolated in a 52% yield. .sup.1H
NMR (60 MHz, CDCl.sub.3): .delta. 6.39 (s, 1H), 5.89 (s, 1H), 4.90
(s, 2H), 4.28 (q, J=6.0 Hz, 2H), 3.50 (s, 2H), 1.32 (t, J=6.0 Hz,
3H); FT-IR (film): 2983.3, 2935.3, 2264.3, 1753.6, 1719.7, 1640.0,
1448.3, 1368.2, 1310.3, 1177.0, 1027.1, 817.2 cm.sup.-1; GC/MS (EI)
m/z (%): 198 (2) [M.sup.++H], 152 (40), 129 (25), 101 (38), 85
(100), 83 (45), 68 (80).
Example 4
##STR00031##
[0112] To a stirring solution of 2-hydroxymethylacrylonitrile (21
g, 0.25 mole) and cyanoacetic acid (20.5 g, 0.24 mole) in dry THF
(0.5 l), was added a solution of dicarbodiimide ("DCC") (51.6 g,
0.25 mole) in dry THF (100 mL) over a period of time of 30 minutes
at a temperature of 0.degree. C. The reaction mixture was stirred
overnight at room temperature and the solid material that formed
was filtered off and washed with dry THF. The THF was removed in
vacuo, the residue dissolved in dichloromethane and the solution
passed through a pad of flash silica gel (200 g). The product
obtained was purified additionally by precipitation with diethyl
ether from its solution in dichloromethane furnishing 30.5 grams of
the ester, B in a 81% yield. .sup.1H NMR (250 MHz, CDCl.sub.3):
.delta. 3.58 (s, 2H), 4.80 (m, 2H), 6.13 (m, 1H), 6.19 (m, 1H);
.sup.13C NMR (62.9 MHz, CDCl.sub.3): .delta. 24.4, 64.7, 112.6,
116.0, 116.8, 135.0, 162.4.
Example 5
##STR00032##
[0114] To a stirring mixture of monoethyl malonate (5.1 g, 38.6
mmol), ethyl 2-hydroxylmethyl acrylate (5.02 g, 3.86 mmol), PTSA
(50 mg) and hydroquinone (50 mg), was added toluene (50 mL) and the
mixture was refluxed at a temperature of 150.degree. C. to
azeotropically remove water.
[0115] After cooling, the reaction product was washed consecutively
with 30% brine and water, and the organic layer was dried over
anhydrous sodium sulfate, filtered and the solvent removed by
rotary evaporator. The crude reaction product was purified by
vacuum distillation (98-100.degree. C./0.1 mbar) and the ester, C
was isolated in 80% yield. .sup.1H NMR (60 MHz, CDCl.sub.3):
.delta. 6.36 (s, 1H), 5.87 (s, 1H), 4.89 (s, 2H), 4.05-4.41 (m,
4H), 3.43 (s, 2H), 1.19-1.42 (m, 6H); FT-IR (film): 2984.7, 2908.6,
1735.3 (br), 1640.5, 1513,6, 1447.6, 1332.2, 1145.4, 1031.7, 817.2
cm-1; GC/MS (EI) m/z (%): 245 (2) [M.sup.++H], 226 (2), 199 (20),
153 (20), 129 (70), 115 (100), 101 (40), 85 (45), 43 (65).
Example 6
##STR00033##
[0117] To a stirring mixture of monoethyl malonate (10.18 g, 77
mmol), ethyl 2-hydroxylmethyl acrylonitrile (7.67 g, 92 mmol),
conc. H.sub.2SO.sub.4 (3 drops) and hydroquinone (1.0 g), was added
toluene (50 mL) and the mixture was refluxed at a temperature of
150.degree. C. to azeotropically remove water.
[0118] After cooling, the reaction product was washed consecutively
with 30% brine and water, and the organic layer was dried over
anhydrous sodium sulfate, filtered and the solvent removed by
rotary evaporator. The crude reaction product was purified by
vacuum distillation (86-88.degree. C./0.05 mbar) and 7.5 g, 38 mmol
of the ester, D was isolated in 49% yield. .sup.1H NMR (60 MHz,
CDCl.sub.3): .delta. 6.10 (s, 2H), 4.75 (s, 2H), 4.20 (q, J=6.6 Hz,
2H), 3.47 (s, 2H), 1.34 (t, J=6.6 Hz, 3H); FT-IR (film): 3118.1,
2986.9, 2909.0, 2230.0, 1736.0, 1629.3, 1447.3, 1371.1, 1147.8,
1033.0, 959.6 cm.sup.-1; GC/MS (EI) m/z (%): 197 (2) [M.sup.+], 170
(40), 152 (100), 125 (10), 115 (50), 107 (15), 87 (25), 79 (45), 66
(90), 53 (40), 43 (60).
Example 7
##STR00034##
[0120] To a stirring mixture of PRIMENE 81-R iminium-MSA (5.86 g,
20 mmol) and cyanoacetate, A (g, 20 mmol), was added 10 mg of
hydroquinone and degassed for a period of time of 5 minutes at room
temperature. Immediately thereafter, the degassed stirring mixture
was vacuum distilled (0.2 mbar) at a temperature of 200.degree. C.
The cyanoacrylate ester, E was collected as a colourless oil (60%
purity by GC, 36% yield). .sup.1H NMR (60 MHz, CDCl.sub.3): .delta.
7.01 (s, 1H), 6.58 (s, 1H), 6.36 (s, 1H), 5.88 (s, 1H), 4.95 (s,
1H), 4.27 (q, J=6.6 Hz, 2H), 1.30 (t, J=6.6 Hz, 3H); FT-IR (film):
3125.4 (C.dbd.C), 2937.7, 2875.0, 2238.3 (CN), 1723.8 (b, s, CO),
1641.6 (C.dbd.C), 1389.2, 1310.6, 1155.5, 1026.7, 803.6
cm.sup.-1.
Example 8
##STR00035##
[0122] To a stirring mixture of PRIMENE 81-R iminium-MSA (2.93 g,
10 mmol) and the triester, C (2.44 g, 10 mmol), was added 10 mg of
hydroquinone and degassed for a period of time of 5 minutes at room
temperature. Immediately thereafter, the degassed stirring mixture
was vacuum distilled (0.1 mbar) at a temperature of 200.degree. C.
The triester, F was collected as a colourless oil (1.7 g,
110-120.degree. C./0.1 mbar, 43% purity by GC, 28% yield). GC/MS
shows the sample is a mixture of monomer and acetate (1:1.3);
.sup.1H NMR (60 MHz, CDCl.sub.3): .delta. 6.51 (s, 1H), 6.34 (s,
2H), 5.86 (s, 1H), 4.94 (s, 1H), 4.39-4.04 (m, 4H), 1.42-1.18 (m,
6H); FT-IR (film): 2984.0, 2908.7, 1731.5, 1640.6, 1400.5, 1330.5,
1272.1, 1191.5, 1144.1, 1029.3, 813.1 cm.sup.-1.
Example 9
##STR00036##
[0124] To a stirring mixture of PRIMENE 81-R iminium-MSA (2.93 g,
10 mmol) and the diester nitrile, D (1.97 g, 10 mmol), was added 10
mg of hydroquinone and degassed for a period of time of 5 minutes
at room temperature. Immediately thereafter, the degassed stirring
mixture was vacuum distilled (0.1 mbar) at a temperature of
200.degree. C. The diester nitrile, G was collected as a colourless
oil (1.7 g, 94-104.degree. C./0.25-0.35 mbar, 80% purity by GC, 65%
yield). .sup.1H NMR (60 MHz, CDCl.sub.3): .delta. 6.62 (s, 2H),
6.12 (s, 2H), 4.81 (s, 2H), 4.26 (q, J=6.0 Hz, 2H), 1.33 (t, J=6.0
Hz, 3H); FT-IR (film): 3118.4, 2985.8, 2229.9, 1736.1, 1628.7,
1407.3, 1371.9, 1331.0, 1191.8, 1030.2, 805.9 cm.sup.-1.
Example 10
##STR00037##
[0126] To a stirring mixture of PRIMENE 81-R iminium-MSA (2.93 g,
10 mmol) and the dinitrile ester, B (1.50 g, 10 mmol), was added 10
mg of hydroquinone and degassed for a period of time of 5 minutes
at room temperature. Immediately thereafter, the degassed stirring
mixture was vacuum distilled (0.2 mbar) at a temperature of
200.degree. C. The dinitrile ester, K was collected as a colourless
oil (0.96 g, 140-160.degree. C./0.2-0.3 mbar, 43% purity by NMR,
25% yield). The sample was determined to contain 2-hydroxylmethyl
acrylonitrile. .sup.1H NMR (60 MHz, CDCl.sub.3): .delta. 7.04 (s,
1H), 6.64 (s, 1H), 6.12 (s, 2H), 4.82 (s, 2H); FT-IR (film):
3124.9, 2960.9, 2874.6, 2229.5, 1745.0, 1678.1, 1528.9, 1284.3,
1177.4, 955.0, 802.5 cm.sup.-1.
[0127] The table below shows the starting intermediate, the
resulting electron deficient olefin, the purity of the resulting
electron deficient olefin and the yield in which some of the
electron deficient olefins described above were obtained.
TABLE-US-00001 TABLE Purity Electron Deficient by GC Yield
Intermediate Olefin (%) (% ) ##STR00038## ##STR00039## 60 36
##STR00040## ##STR00041## 43 28 ##STR00042## ##STR00043## 80 65
##STR00044## ##STR00045## 43 25
* * * * *