U.S. patent application number 09/800944 was filed with the patent office on 2001-09-27 for layered compositions with multi-charged onium ions as exchange cations, and their application to prepare monomer, oligomer, and polymer intercalates and nanocomposites prepared with the layered compositions of the intercalates.
This patent application is currently assigned to AMCOL International Corporation. Invention is credited to Lan, Tie, Liang, Ying, Psihogios, Vasiliki, Westphal, Erin K..
Application Number | 20010025076 09/800944 |
Document ID | / |
Family ID | 23039154 |
Filed Date | 2001-09-27 |
United States Patent
Application |
20010025076 |
Kind Code |
A1 |
Lan, Tie ; et al. |
September 27, 2001 |
Layered compositions with multi-charged onium ions as exchange
cations, and their application to prepare monomer, oligomer, and
polymer intercalates and nanocomposites prepared with the layered
compositions of the intercalates
Abstract
Intercalated layered materials prepared by co-intercalation of a
multi-charged onium ion spacing/coupling agent and a matrix polymer
between the planar layers of a swellable layered material, such as
a phyllosilicate, preferably a smectite clay. The spacing of
adjacent layers of the layered materials is expanded at least about
3 .ANG., preferably at least about 5 .ANG., usually to about 15-20
.ANG., e.g., 18 .ANG. with the di-charged onium ion
spacing/coupling agent. The intercalation of the matrix polymer
then increases the spacing between adjacent layers to at least
about 15 .ANG., preferably to about 20 .ANG. to about 30 .ANG..
Inventors: |
Lan, Tie; (Lake Zurich,
IL) ; Westphal, Erin K.; (Oakwood Hills, IL) ;
Psihogios, Vasiliki; (Wheeling, IL) ; Liang,
Ying; (Lake Zurich, IL) |
Correspondence
Address: |
MARSHALL, O'TOOLE, GERSTEIN, MURRAY & BORUN
6300 SEARS TOWER
233 SOUTH WACKER DRIVE
CHICAGO
IL
60606-6402
US
|
Assignee: |
AMCOL International
Corporation
|
Family ID: |
23039154 |
Appl. No.: |
09/800944 |
Filed: |
March 7, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09800944 |
Mar 7, 2001 |
|
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09272279 |
Mar 19, 1999 |
|
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6262162 |
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Current U.S.
Class: |
524/445 ;
501/148 |
Current CPC
Class: |
C08K 9/04 20130101; Y10T
428/261 20150115; Y10T 428/268 20150115; Y10T 428/269 20150115;
C01B 33/44 20130101 |
Class at
Publication: |
524/445 ;
501/148 |
International
Class: |
C04B 033/00; C08K
003/34 |
Claims
What is claimed is:
1. A surface-modified layered silicate material comprising stacked
layers of clay silicate platelets having at the platelet internal
surfaces, a multi-charged onium ion intercalated and ion-exchanged
in place of multiple interlayer cations.
2. The surface-modified layered silicate material of claim 1,
wherein the interlayer cations are substituted with multi-charged
onium ions in a molar ratio of at least 0.25 moles of multi-charged
onium ions per mole of interlayer exchangeable cations, to expand
the interlayer spacing of the clay silicate platelets at least
about 3 .ANG..
3. The surface-modified layered silicate material of claim 2,
wherein the molar ratio of multi-charged onium ions to clay
interlayer exchangeable cations is at least 0.5:1.
4. The surface-modified layered silicate material of claim 3,
wherein the molar ratio of multi-charged onium ions to clay
interlayer exchangeable cations is at least 1:1.
5. The surface-modified layered silicate material of claim 1,
wherein the multi-charged onium ions are selected from the group
consisting of di-ammonium, di-phosphonium, di-sulfonium,
di-oxonium; ammonium/phosphonium; ammonium/sulfonium;
ammonium/oxonium; phosphonium/sulfonium; phosphonium/oxonium;
sulfonium/oxonium; and mixtures thereof.
6. A method of intercalating a layered silicate material with
multi-charged onium ions comprising ion-exchanging multi-charged
onium ions with the layered silicate material to substitute the
multi-charged onium ions in place of layered silicate interlayer
cations.
7. A method in accordance with claim 6, wherein the ion-exchange is
achieved by dispersing the layered silicate material and the
multi-charged onium ions in a carrier comprising water to contact
the layered silicate material with the multi-charged onum ions for
a time sufficient to ion-exchange the multi-charged onium ions for
at least a portion of the layered silicate material interlayer
cations; separating the ion-exchanged layered silicate material
from the carrier; drying the ion-exchanged layered silicate
material; and grinding the layered silicate material to a desired
particle size distribution.
8. A method in accordance with claim 7, wherein the multi-charged
onium ions are dispersed in the carrier at a molar ratio of
multi-charged onium ions:layered silicate interlayer exchangeable
cations of at least 0.25:1.
9. A method in accordance with claim 8, wherein the multi-charged
onium ions are dispersed in the carrier at a molar ratio of
multi-charged onium ions:layered silicate interlayer exchangeable
cations of at least 0.50:1.
10. A method in accordance with claim 9, wherein the multi-charged
onium ions are dispersed in the carrier at a molar ratio of
multi-charged onium ions:layered silicate interlayer exchangeable
cations of at least 1:1.
11. A method in accordance with claim 6, wherein the multi-charged
onium ions are selected from the group consisting of di-ammonium,
di-phosphonium, di-sulfonium, di-oxonium; ammonium/phosphonium;
ammonium/sulfonium; ammonium/oxonium; phosphonium/sulfonium;
phosphonium/oxonium; sulfonium/oxonium; and mixtures thereof.
12. The method of claim 6, wherein the onium ion includes two
positively charged atoms separated by 5 .ANG. to 24 .ANG..
13. The method of claim 12, wherein the onium ion includes an
organic radical covalently bonded to one of the positively charged
atoms having a chain length of at least 6 carbon atoms.
14. The method of claim 12, wherein the 5 .ANG. to 24 .ANG. spacing
between positively charged atoms is achieved by a separating moiety
having 3 to about 12 carbon atoms in its backbone.
15. The method of claim 6, wherein the multi-charged onium ion is a
compound of the formula: 6wherein R is an alkylene, aralkylene or
substituted alkylene spacing moiety, ranging from C.sub.3 to
C.sub.24, straight or branched chain; R.sub.1, R.sub.2, R.sub.3 and
R.sub.4 are moieties, same or different, selected from the group
consisting of hydrogen, alkyl, aralkyl, benzyl, substituted benzyl,
straight or branched chain alkyl-substituted and
halogen-substituted; ethoxylated alkyl; propoxylated alkyl;
ethoxylated benzyl; propoxylated benzyl; Z.sup.1 and Z.sup.2, same
or different, are selected from the group consisting of
non-existent and any of the moieties as defined for R.sub.1,
R.sub.2, R.sub.3 and R.sub.4.
16. The method of claim 15, wherein Z.sup.2 or Z.sup.2 is
positively charged.
17. A composite material comprising a matrix polymer, and the
organoclay of claim 1.
18. The composite material of claim 17, wherein the matrix polymer
is a polyamide oligomer or polymer.
19. The composite material of claim 17, wherein the onium ion
includes two positively charged nitrogen atoms separated by 5 .ANG.
to 24 .ANG..
20. The composite material of claim 19, wherein the onium ion
includes an organic radical covalently bonded to one of the
positively charged atoms, said organic radical having a chain
length of at least six carbon atoms.
21. A nanocomposite composition comprising about 0.05 weight
percent to about 40 weight percent of a layered silicate material
intercalated with a multi-charged onium ion spacing agent and about
60 weight percent to about 99.95 weight percent of a matrix
polymer, wherein the intercalated layered silicate material is
dispersed uniformly throughout the matrix polymer.
22. A nanocomposite composition in accordance with claim 21,
wherein the matrix polymer is co-intercalated into the layered
silicate material.
23. A nanocomposite composition in accordance with claim 22,
wherein the matrix polymer is co-intercalated into the layered
silicate material while dispersing the layered material throughout
the matrix polymer.
24. A nanocomposite composition in accordance with claim 22,
wherein the matrix polymer is co-intercalated into the layered
silicate material prior to dispersing the layered silicate material
throughout the matrix polymer.
25. A nanocomposite composition in accordance with claim 21,
wherein the matrix polymer is a polymer or oligomer of the reaction
product of meta-xylylene diamine and adipic acid.
26. A nanocomposite composition in accordance with claim 21,
wherein the multi-charged onium ions include at least one moiety
covalently bonded to a protonated nitrogen atom that has a length
of at least six carbon atoms.
27. A nanocomposite composition comprising a matrix polymer in an
amount of about 40% to about 99.95% by weight, and about 0.05% to
about 60% by weight of an intercalated phyllosilicate material
formed by contacting a phyllosilicate with intercalant
multi-charged onium ions to form an intercalating composition,
having a molar ratio of multi-charged onium ions:phyllosilicate
interlayer exchangeable cations of at least about 0.25:1 to achieve
sorption of the multi-charged onium ions between adjacent spaced
layers of the phyllosilicate to expand the spacing between a
predominance of the adjacent phyllosilicate platelets at least
about 3 .ANG., when measured after sorption of the multi-charged
onium ions, and a second intercalant disposed between adjacent
spaced layers of the phyllosilicate material, said second
intercalant comprising a thermosetting or thermoplastic oligomer or
polymer.
28. A composition in accordance with claim 27, wherein the
intercalated phyllosilicate is exfoliated into a predominance of
individual platelets.
29. A composition in accordance with claim 27, wherein the molar
ratio of intercalant onium ions:phyllosilicate interlayer
exchangeable cations is at least 0.5:1.
30. A composition in accordance with claim 27, wherein the molar
ratio of intercalant onium ions:phyllosilicate interlayer
exchangeable cations is at least 1:1.
31. A composition in accordance with claim 27, wherein the matrix
polymer is selected from the group consisting of an epoxy; a
polyamide; a polyvinyl alcohol; a polycarbonate; a polyvinylimine;
a polyvinylpyrrolidone; a polyethylene terephthalate; and a
polybutylene terephthalate.
32. A composition in accordance with claim 27, wherein the matrix
polymer is MXD6 nylon.
33. A nanocomposite concentrate composition comprising about 10% by
weight to about 90% by weight of a layered material intercalated
with multi-charged onium ions and about 10 weight percent to about
90 weight percent of a matrix oligomer or polymer, wherein the
intercalated layered silicate material is dispersed uniformly
throughout the matrix polymer.
34. A nanocomposite composition in accordance with claim 33,
wherein the matrix polymer is intercalated into the layered
silicate material.
35. A nanocomposite composition in accordance with claim 34,
wherein the matrix polymer is intercalated into the layered
silicate material while dispersing the layered material throughout
the matrix polymer.
36. A nanocomposite composition in accordance with claim 34,
wherein the matrix polymer is intercalated into the layered
silicate material prior to dispersing the layered silicate material
throughout the matrix polymer.
37. A nanocomposite composition in accordance with claim 33,
wherein both the matrix polymer and the polymer intercalated into
the layered material are a polymer or oligomer of the reaction
product of meta-xylylene diamine and adipic acid.
38. A nanocomposite composition in accordance with claim 33,
wherein prior to intercalating the layered material with the
polymer of meta-xylylene diamine and a dicarboxylic acid, the
layered material is first intercalated with multi-charged onium
ions that include at least one moiety covalently bonded to a
positively charged nitrogen atom that has a length of at least six
carbon atoms.
39. A method of manufacturing the composite material of claim 17,
containing about 10% to about 99.95% by weight of a matrix polymer
selected from the group consisting of a thermoplastic polymer, a
thermosetting polymer, and mixtures thereof, and about 0.05% to
about 60% by weight of the organoclay of claim 1, comprising
intercalating a layered material by contact with multi-charged
onium ions, mixing the intercalated layered material with a melt of
the matrix polymer, and mixing the polymer melt and the
intercalated layered material together to intercalate the matrix
polymer between adjacent platelets of the layered material.
40. The method of claim 39, wherein mixing of the intercalate and
the polymer melt is accomplished by extruding the
intercalate/polymer melt mixture.
41. A method of manufacturing a composite material comprising 10%
to 99.95% by weight of a matrix polymer and about 0.05% to about
60% by weight of an intercalate comprising intercalating a layered
silicate material by contacting the layered silicate material with
multi-charged onium ions to exchange the multi-charged onium ions
for at least a portion of the interlayer exchangeable cations of
the layered material; mixing the intercalated layered silicate
material with one or more monomer or oligomer reactants capable of
polymerizing to form said matrix polymer, while in contact with
said intercalate, and subjecting the mixture to conditions
sufficient to polymerize said reactants to form said matrix
polymer.
42. A method of manufacturing a composite material comprising
contacting a layered silicate material with multi-charged onium
ions to intercalate the multi-charged onium ions between adjacent
layers of said layered silicate material, thereby increasing the
spacing between adjacent layers of the layered material at least 3
.ANG.; simultaneously or subsequently contacting the layered
silicate material with a solution or dispersion of an oligomer or
polymer to intercalate the oligomer or polymer between adjacent
layers of the layered silicate material to expand the spacing
between the adjacent layers of said layered material at least an
additional 3 .ANG.; and mixing the layered silicate material,
having said multi-charged onium ions and said oligomer or polymer
intercalated between adjacent layers, with an oligomer or polymer
matrix material.
43. The method of claim 42, wherein the oligomer or polymer
intercalated between adjacent layers of said layered silicate
material is the same oligomer or polymer matrix material mixed with
said intercalate.
44. A method of manufacturing a nanocomposite comprising contacting
a layered silicate material with multi-charged onium ions to
intercalate the multi-charged onium ions between adjacent layers of
the layered silicate material, thereby increasing the spacing
between adjacent layers of the layered silicate material at least 3
.ANG., and simultaneously or subsequently contacting the layered
silicate material with an oligomer or polymer in a form selected
from the group consisting of (i) a solution of the oligomer or
polymer, (ii) a dispersion of said oligomer or polymer and (iii) a
melt of said oligomer or polymer, to intercalate said oligomer or
polymer between adjacent layers of said layered silicate material
and thereby further expand the spacing between adjacent layers of
said layered silicate material an additional at least 3 .ANG..
45. A method of manufacturing a composite material containing about
10% to about 99.95% by weight of a matrix polymer and about 0.05%
to about 60% by weight of an intercalated phyllosilicate material,
said intercalated phyllosilicate having an intercalant
multi-charged onium ion spacing agent intercalated between and
bonded, by ion-exchange, to an inner surface of the phyllosilicate
platelets, comprising: contacting the phyllosilicate with said
intercalant multi-charged onium ion spacing agent, to achieve
intercalation of said intercalant multi-charged onium ion spacing
agent between said adjacent phyllosilicate platelets in an amount
sufficient to space said adjacent phyllosilicate platelets a
distance of at least about 3 .ANG.; and dispersing the intercalate
throughout said matrix polymer to achieve intercalation of a
portion of the matrix polymer between the phyllosilicate
platelets.
46. The method of claim 45, wherein the concentration of the
multi-charged onium ion spacing agent is in a molar ratio of onium
ions:phyllosilicate interlayer exchangeable cations of at least
0.25:1.
47. The method of claim 46, wherein said phyllosilicate is
contacted with said intercalant multi-charged onium ion spacing
agent, said phyllosilicate, and a matrix oligomer or polymer
intercalant, wherein the concentration of the multi-charged onium
ion spacing agent is in a molar ratio of onium ions:phyllosilicate
interlayer exchangeable cations of at least 0.5:1.
48. The method of claim 47, wherein the concentration of the onium
ion spacing agent is in a molar ratio of onium ions:phyllosilicate
interlayer exchangeable cations of at least 1:1.
49. A method of manufacturing a composite material containing about
40% to about 99.95% by weight of a matrix thermoplastic or
thermosetting polymer, and about 0.05% to about 60% by weight of an
intercalated phyllosilicate material, said intercalated
phyllosilicate having an intercalant multi-charged onium ion
spacing agent intercalated between adjacent phyllosilicate
platelets comprising: contacting the phyllosilicate with an
intercalating composition including an intercalant multi-charged
onium ion spacing agent in a molar ratio of onium
ions:phyllosilicate interlayer cations of at least 0.25:1, and a
thermoplastic or thermosetting matrix oligomer or polymer
intercalant to achieve intercalation of said intercalant
multi-charged onium ion spacing agent and said matrix oligomer or
polymer intercalant between said adjacent phyllosilicate platelets
in an amount sufficient to space said adjacent phyllosilicate
platelets at least an additional 3 .ANG.; combining the
intercalated phyllosilicate with said thermoplastic or
thermosetting matrix polymer, and heating the matrix polymer
sufficiently to provide for flow of said matrix polymer; and
dispersing said intercalated phyllosilicate throughout said matrix
polymer.
50. A method in accordance with claim 49, wherein the amount of
multi-charged onium ion spacing agent intercalated into the
phyllosilicate material is in a molar ratio of at least 0.5:1,
onium ions:exchangeable cations in the interlayer spaces of the
phyllosilicate material.
51. A method in accordance with claim 50, wherein the amount of
intercalant multi-charged onium ion spacing agent intercalated into
the phyllosilicate material is in a molar ratio of at least 1:1,
onium ions:exchangeable cations in the interlayer spaces of the
phyllosilicate material.
52. A method in accordance with claim 51, wherein the molar ratio
of intercalated multi-charged onium ion spacing/coupling agent to
interlayer phyllosilicate cations is from about 1:1 to about
1:5.
53. A method in accordance with claim 35, wherein the matrix
oligomer or polymer is intercalated into the phyllosilicate by
melting the matrix oligomer or polymer and dispersing the
phyllosilicate throughout the melt.
54. A method in accordance with claim 53, wherein the mixing is
accomplished in an extruder.
55. A method of manufacturing a composite material containing about
40% to about 99.95% by weight of a matrix oligomer or polymer and
about 0.05% to about 60% by weight of an intercalated
phyllosilicate material comprising intercalating the phyllosilicate
material with a multi-charged onium ion spacing agent by contacting
the phyllosilicate with multi-charged onium ions in a molar ratio
of onium ions:phyllosilicate interlayer exchangeable cations of at
least 0.25:1; forming a mixture of -the intercalated phyllosilicate
material with reactants capable of reaction to form a matrix
oligomer or polymer; and subjecting the mixture to conditions
sufficient to react and polymerize the reactants, to polymerize the
reactants while in contact with the intercalated phyllosilicate and
to co-intercalate the resulting oligomer or polymer between
adjacent platelets of the phyllosilicate material, wherein the
reactants are combined in amounts such that the resulting composite
material contains 40% to 99.95% oligomer or polymer and 0.05% to
60% intercalated phyllosilicate.
56. An intercalate formed by contacting a layered silicate material
with a multi-charged onium ion intercalant, said intercalate having
a molar ratio of intercalant multi-charged onium ions to interlayer
cations of at least about 0.25:1, to achieve sorption and
ion-exchange of the multi-charged onium ions with interlayer
exchangeable cations of said layered silicate material to expand
the spacing between a predominance of the adjacent platelets of
said layered silicate material to at least about 3 .ANG., when
measured after ion-exchange with the multi-charge onium ions; and
an oligomer or polymer second intercalant disposed between adjacent
layers of said layered silicate material, to expand the spacing
between a predominance of the adjacent platelets an additional at
least 3 .ANG..
57. An intercalate in accordance with claim 56, wherein the layered
silicate material is contacted with said multi-charged onium ions
in an intercalant composition comprising said layered silicate
material, said multi-charged onium ions and a carrier for said
multi-charged onium ions.
58. In a method of preventing the passage of oxygen to a material
to be protected from oxygen contact comprising disposing a film of
sheet material between an oxygen source and the material to be
protected, the improvement comprising the film of sheet material,
said film of sheet material comprising a matrix polymer having
homogeneously dispersed therein a surface-modified layered silicate
material having a multi-charged onium ion intercalated and
ion-exchanged in place of multiple interlayer cations in an amount
sufficient to reduce the amount of oxygen contacting the material
to be protected.
59. In the method of claim 27, wherein the organoclay is dispersed
throughout the matrix polymer in an amount of about 2% to about 10%
by weight of the matrix polymer.
60. In the method of claim 28, wherein the matrix polymer is
selected from the group consisting of an epoxy, a polyamide, and
polyethylene terephthalate.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to intercalated layered
materials and, optionally, exfoliates thereof, prepared by
contacting, and thereby intercalating, a layered silicate material,
e.g., a phyllosilicate, such as a smectite clay, with a
spacing/coupling agent that is multi-positively charged
(hereinafter "multi-charged"), preferably dual-charged, and
co-intercalation of the layered material with a co-intercalant (as
co-intercalant polymerizable reactants, or as the oligomer
co-intercalant or polymer co-intercalant) to form nanocomposite
materials. The co-intercalant monomer, oligomer or polymer can be
intercalated after or together with intercalation of the
multi-charged spacing/coupling agent, such as by direct
compounding, e.g., by combining a multi-charged onium
ion-intercalated layered material and a co-intercalant monomer,
polymer or oligomer in a mixing or extruding device to produce the
co-intercalated layered material and the nanocomposite. The
interlaminar spacing of adjacent layers (platelets) of the layered
material (d-spacing minus one platelet thickness of the layered
material) is expanded at least 3 .ANG., preferably at least 5
.ANG., to at least about 10 .ANG., preferably to at least about 15
.ANG., and usually to about 18 .ANG. by contacting the layered
material with the multi-charged spacing/coupling agent for
simultaneous or subsequent intercalation with co-intercalant
polymer reactants, an oligomer co-intercalant or a polymer
co-intercalant. The multi-charged spacing/coupling agents have at
least two charged, ion-exchange atoms capable of ion-exchanging
with Li.sup.+, Na.sup.+, K.sup.+, Ca.sup.+2, Mg.sup.+2, or other
inorganic cations that occur within the interlayer spaces between
adjacent silicate layers or platelets of the layered silicate
materials being intercalated. The association of the layered
material inorganic cations with the at least two charged sites of
the multi-charged spacing/coupling agent enables the conversion of
the hydrophilic interior clay platelet surfaces to hydrophobic
platelet surfaces, by substantially complete ion-exchange of the
interlayer exchangeable cations on the platelet surfaces with the
onium ions, while intercalating and ion-exchanging substantially
less onium ions into the space between adjacent platelets, leaving
more space for co-intercalation of an oligomer or polymer when
compared with single-charged onium ion analogues. Therefore,
polymerizable monomers capable of reacting to form a polymer
co-intercalant, or polymerizable oligomer co-intercalant molecules,
or a co-intercalant polymer can be easily and more fully
intercalated between adjacent platelets of the layered silicate
material, e.g., smectite clay platelets.
[0002] In accordance with the preferred embodiment of the present
invention, a fully polymerized co-intercalant polymer, having a
weight average molecular weight between about 100 and about 5
million, preferably about 1,000 to about 500,000, can be
co-intercalated between adjacent platelets of the multi-charged
spacing/coupling agent-intercalated layered material, preferably
simultaneously with dispersing the multi-charged onium
ion-intercalated layered material into a matrix polymer, i.e., by
direct compounding of the multi-charged spacing/coupling
agent-intercalated layered material with the co-intercalant
oligomer or polymer, by adding excess co-intercalant oligomer or
polymer, and without separation of the resulting intercalate, the
excess co-intercalant polymer becomes the matrix polymer--the same
as the co-intercalant polymer. The intercalation of the
multi-charged spacing/coupling agent and a co-intercalant oligomer
or polymer, or its monomeric reactants (co-intercalant
polymerizable monomer reactants, co-intercalant oligomer, and
co-intercalant polymer being referred to collectively as
"intercalant polymer" or "co-intercalant polymer" hereinafter for
simplicity), results in a completely homogeneous dispersion of
co-intercalated layered material in a matrix polymer, or a
nanocomposite composition. Optionally, the nanocomposite material
can be sheared, at or above the melt temperature of the matrix
polymer, to exfoliate up to 100% of the tactoids or platelet
clusters into individual platelets such that more than 50% by
weight of the platelets are in the form of single platelets, e.g.,
more than 60%; more than 70%; more than 80%; or more than 90% by
weight of the layered material can be completely exfoliated into
single platelet layers.
[0003] The intercalates of the present invention can be used as
organoclays for sorption of organic materials, or can be dispersed
uniformly into solvents to increase the viscosity of organic
liquids; or the intercalates can be dispersed into matrix polymer
materials to form polymer/clay intercalate nanocomposites, e.g., by
direct compounding of the multi-charged spacing/coupling
agent-intercalated clay with sufficient co-intercalant oligomer or
polymer to achieve sufficient intercalation of the clay to form a
concentrate, that can later be mixed with a matrix polymer and/or
additional intercalant polymer, or different polymeric materials to
form a nanocomposite. Alternatively, the multi-charged
spacing/coupling agent-intercalated clay can be co-intercalated
with monomer reactants that are polymerizable to form the polymer
co-intercalant.
[0004] In another embodiment of the present invention, the
multi-charged spacing/coupling agent-intercalated layered material
can be dispersed in a matrix monomer followed by polymerization of
the matrix monomer, in-situ, e.g., by adding a curing agent, to
form the nanocomposite material. Also, curing agents can be
directly incorporated into monomeric reactants that are
co-intercalated between platelets of the multi-charged
spacing/coupling agent-intercalated clay followed by polymerization
of the reactant intercalant monomers that have been intercalated
into the clay interlayer galleries.
[0005] In accordance with an important feature of the present
invention, if an intercalant polymer is co-intercalated into the
multi-charged spacing/coupling agent-intercalated clay galleries to
form a co-intercalate and additional polymer is added to form a
nanocomposite, the co-intercalant polymer can be directly
compounded with the matrix polymer to form a nanocomposite easily,
and the co-intercalate can be more fully loaded with co-intercalant
polymer than if a single-charged onium ion spacing/coupling agent
were used to space the platelets. If the polymerizable
co-intercalant monomers, or a polymerizable oligomer intercalant is
co-intercalated into the clay galleries, the co-intercalant(s) can
be polymerized together with a desired monomer, oligomer or polymer
matrix material, and the matrix material then can be polymerized or
further polymerized together with the co-intercalant and compounded
to form the nanocomposite.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0006] It is well known that phyllosilicates, such as smectite
clays, e.g., sodium montmorillonite and calcium montmorillonite,
can be treated with organic molecules, such as organic ammonium
ions, phosphonium ions, or sulfonium ions (onium ions), to
intercalate the organic molecules between adjacent, planar silicate
layers, for ion-exchange of the organic onium ion molecules with
the interlayer exchangeable cations to space the adjacent layers or
platelets of the layered silicate material (interlaminar spacing)
sufficiently for intercalation of a polymer between the spaced
layers, see, for example, U.S. Pat. Nos. 4,739,007; 4,810,734 and
5,164,460. The thus-treated, intercalated phyllosilicates, having
interlayer spacings increased by at least 3 .ANG., preferably at
least 5 .ANG., to an interlayer (interlaminer) spacing of at least
about 10-25 Angstroms (.ANG.) and up to about 100 .ANG. then can be
exfoliated, e.g., the silicate layers are separated, e.g.,
mechanically, by high shear mixing. The individual silicate layers,
when admixed with a matrix polymer, before, after or during the
polymerization of the matrix polymer, e.g., a polyamide--see U.S.
Pat. Nos. 4,739,007; 4,810,734; 5,102,948; and 5,385,776--have been
found to substantially improve one or more properties of the matrix
polymer, such as mechanical strength, oxygen impermeability, and/or
high temperature characteristics.
[0007] Exemplary prior art composites, also called
"nanocomposites", are disclosed in a published PCT application of
Allied Signal, Inc. WO 93/04118 and U.S. Pat. No. 5,385,776,
disclosing the admixture of individual platelet particles derived
from intercalated layered silicate materials, with a matrix polymer
to form a nanocomposite having one or more properties of the matrix
polymer improved by the addition of the at least partially
exfoliated intercalate. As disclosed in WO 93/04118 and U.S. Pat.
No. 5,554,670, the intercalate is formed (the interlayer spacing
between adjacent silicate platelets is increased) by adsorption of
a silane coupling agent or an onium cation, such as a quaternary
ammonium compound, having a reactive group which is compatible with
the matrix polymer. Such quaternary ammonium cations are well known
to convert a highly hydrophilic clay, such as sodium or calcium
montmorillonite, into an organophilic clay capable of sorbing
organic molecules.
[0008] In accordance with a preferred embodiment of the present
invention, intercalates are prepared by contacting a layered
silicate material, such as a phyllosilicate, with a multi-charged
onium ion spacing/coupling agent, such as a di-onium ion
spacing/coupling agent compound, and having at least 2 carbon
atoms, up to about 24 carbon atoms separating the two onium
cations. Exemplary of such suitable multi-charged spacing/coupling
agent molecules include quaternary diammonium ions, disulfonium
ions, diphosphonium ions, dioxonium ions, or any multi-charged
onium ion compound of an element in Groups V or VI of the periodic
table of elements.
[0009] The multi-charged onium ion spacing/coupling agents useful
in accordance with the present invention may be multi-charged upon
dissociation of anions from the molecule when dissolved in water
and/or an organic solvent, or the molecule may be neutral and
subsequently protonated to provide onium ion molecules having
multiple positively charged atoms, in solution.
[0010] Depending upon the cation exchange capacity of the layered
silicate material, e.g., a smectite clay, the interior platelet
surfaces of the silicate platelets include negative charge centers
that have spacings that vary between about 4 .ANG. and about 20
.ANG. (equal to the spacing, or distance, between adjacent
exchangeable cations in the interlaminar space).
[0011] In accordance with the principles of the present invention,
it has been found that multi-charged onium ion spacing/coupling
agents can be intercalated between adjacent platelets to
ion-exchange with interlayer cations, e.g., Na.sup.+ ions, to
balance the negative charge centers within the same silicate
platelet surface, at each properly spaced charged onium ion atom,
to space adjacent platelets sufficiently, using less
spacing/coupling agent. In the preferred embodiment, at least two
of the charged atoms of the multi- charged onium ion
spacing/coupling agent are spaced with intermediate organic
molecules, e.g., --CH.sub.2--CH.sub.2--;
--CH.sub.2--CH.sub.2--CH.sub.2; and the like, to space the charged
onium ion atoms (e.g., N.sup..+-. space --N.sup.+) a distance of
about 5 .ANG. (for high charge density layered materials) to about
24 .ANG. (for low charge density layered materials). With such
preferred spacing between charged onium ion atoms, ion-exchange
with interlayer cations occurs at both charged onium ion atoms,
thereby necessitating less onium ion intercalation to achieve
complete ion-exchange, while achieving sufficient silicate platelet
spacing for oligomer or polymer co-intercalation, and permitting
co-intercalation of higher quantities of co-intercalant oligomer or
polymer.
[0012] As shown in FIGS. 1A and 1B, a layered material having a
high charge density, having a spacing between adjacent interlayer
platelet surface negative charge centers in the range of about 6
.ANG. to about 12 .ANG. can be ion-exchanged at both adjacent
charged atoms of a dual-charged onium ion spacing/coupling agent
that has the charged atoms spaced a distance of about 4 .ANG. to
about 14 .ANG. or 16 .ANG.. The spacing between the closest two
charged atoms of the multi-charged onium ion spacing/coupling agent
need not be exactly the same as the spacing between adjacent
exchangeable cations on the platelet surface of the layered
material since each negative charge within and extending above the
platelet surface (corresponding to the location of the exchangeable
cations) diffuses radially outwardly, from the negative charge
center, a distance of about 5 .ANG.. The dashed line circles
surrounding the adjacent negative charge centers, as shown in FIGS.
1A and 1B, represent diffusing negative charges that are weaker
farther away from the negative charge center, and are located
directly above the exchangeable cations, e.g., Na.sup.+, as shown
in FIGS. 1A and 1B. Preferred spacing between closest charged atoms
of the spacing/coupling agent for high to medium charge density
(150 milliequivelents per 100 grams C.E.C.* to 70 milliequivelents
per 100 grams C.E.C.*) layered materials is about 6 .ANG. to about
20 .ANG., corresponding to a C.sub.3 to C.sub.10 molecule backbone
in the organic spacing molecule between charged onium ion atoms.
Preferred spacing between onium ion spacing/coupling agent charged
atoms for medium to low charge density (70 milliequivelents per 100
grams C.E.C.* to 30 milliequivelents per 100 grams C.E.C.* )
layered materials is about 12 .ANG. to about 24 .ANG.,
corresponding to a C.sub.6 to C.sub.12 molecule backbone in the
organic spacing molecule covalently bonded to both charged onium
ion atoms.
[0013] *Cation exchange capacity.
[0014] In accordance with an important feature of the present
invention, best results are achieved by mixing the layered material
with the (multi-charged spacing/coupling agent, in a concentration
of at least about 0.25 moles of onium ion multi-positively charged,
cation portion of the onium ion compound) per mole of interlayer
exchangeable cations, preferably at least a 0.5:1 molar ratio, more
preferably at least 1:1 molar ratio of multi-charged onium ion
cation:exchangeable interlayer cations. When less than all of the
interlayer cations are ion-exchanged with multi-charged onium ions,
the remainder of the interlayer cations can remain in place, or at
least a portion of the remaining interlayer cations may be
exchanged with single-charged onium ions. For most layered
materials, such as sodium montmorillonite clays, the above molar
ratios are achieved by intercalating at least about 2% by weight,
preferably at least about 5% by weight multi-charged
spacing/coupling agent compound, more preferably at least about 10%
by weight, and most preferably about 30% to about 200% by weight
multi-charged spacing/coupling agent cation, based on the dry
weight of the layered material in the intercalating composition.
Regardless of the concentration of multi-charged spacing/coupling
agent compound in the intercalating composition, the weight ratio
of multi-charged spacing/coupling agent intercalant: layered
material should be at least 1:20, preferably at least 1:10, more
preferably at least 1:5, and most preferably at least about 1:4 to
achieve sufficient intercalation of one or more co-intercalants
such as oligomer or polymer (or its monomeric reactants) between
adjacent inner surfaces of adjacent platelets of the layered
material. The multi-charged spacing/coupling agent compound sorbed
between and ion-exchanged with the silicate platelets, via
ion-exchange at multiple charged atoms, causes surprisingly easy
intercalation of a co-intercalant oligomer or polymer, in greater
amounts than heretofore possible, or intercalation of increased
amounts of monomeric reactants for polymerization in-situ.
[0015] In accordance with an important feature of the present
invention, it has been found that a multi-charged spacing/coupling
agent-intercalated phyllosilicate, such as a smectite clay, can be
co-intercalated easily with a co-intercalant polymer to form an
intercalate that has unexpectedly superior intercalate
dispersibility in a matrix polymer, and unexpectedly can be
co-intercalated with higher amounts of co-intercalate polymer
molecules. The intercalate also can be added to any other matrix
polymer to enhance a number of properties of the matrix polymer,
including tensile strength, heat distortion temperature, glass
transition temperature, gas-impermeability, elongation, and the
like.
[0016] The multi-charged spacing/coupling agent-intercalated
layered material, that is co-intercalated with a polymer
co-intercalant, and/or exfoliates thereof, can be admixed with a
matrix polymer or other organic monomer compound(s) or composition
to increase the viscosity of the organic compound or provide a
matrix polymer/intercalate and/or matrix polymer/exfoliate
composition to enhance one or more of the above- mentioned
properties of the matrix polymer.
[0017] The multi-charged spacing/coupling agent-intercalated
layered material and intercalating process of the present invention
provide a unique organoclay useful for all known purposes of
organoclays, that includes more interlayer space for sorption of
organic liquids and gases. Also, in accordance with a preferred
embodiment of the present invention, the intercalate can be added,
particularly by direct compounding (mixing the intercalate directly
into a matrix polymer melt) of the intercalate with any matrix
polymer, thermoplastic or thermosetting. Examples of
market-available resin systems for use as the co-intercalant
polymer and/or the matrix polymer of the nanocomposites include
epoxy resins such as: Bisphenol A-derived resins, Epoxy cresol
Novolac resins, Epoxy phenol Novolac resins, Bisphenol F resins,
polynuclear phenol-glycidyl ether-derived resins, cycloaliphatic
epoxy resins, aromatic and heterocyclic glycidyl amine resins,
tetraglycidyl-methylenedianiline-deri- ved resins, nylons, such as
nylon-6 and nylon 66, and particularly MXD6 nylon (meta-xylylene
diamine and adipic acid polymerized polyamides).
DEFINITIONS
[0018] Whenever used in this Specification, the terms set forth
shall have the following meanings:
[0019] "Layered Material" shall mean an inorganic material, such as
a smectite clay mineral, that is in the form of a plurality of
adjacent, bound layers and has a thickness, for each layer, of
about 3 .ANG. to about 50 .ANG., preferably about 10 .ANG..
[0020] "Platelets" shall mean individual layers of the Layered
Material.
[0021] "Intercalate" or "Intercalated" shall mean a Layered
Material that includes multi-charged onium ion spacing/coupling
agent molecules disposed between adjacent platelets of the Layered
Material and ion-exchanged with cations of an inner platelet
surface at multiple (at least two) charged atoms of the
spacing/coupling agent to increase the interlayer spacing between
the adjacent platelets at least 3 .ANG., preferably at least 5
.ANG. to an interlayer spacing, for example, of at least about 10
.ANG., preferably to at least about 15 .ANG., e.g., 18 .ANG.; and
after intercalation of a co-intercalant polymer, the d-spacing of
the co-intercalate is increased to at least about 20 .ANG.,
preferably to 25 .ANG. to 35 .ANG..
[0022] "Intercalation" shall mean a process for forming an
Intercalate.
[0023] "Multi-charged Spacing/Coupling Agent" shall mean a
monomeric organic compound that includes at least two positively
charged atoms, such as two or more protonated nitrogen (ammonium or
quaternary ammonium) atoms (N.sup.+); two or more positively
charged phosphorous (phosphonium) atoms (P.sup.+); two or more
positively charged sulfur (suffonium) atoms (S.sup.+); two or more
positively charged oxygen (oxonium) atoms (O.sup.+); or any
combination of two or more N.sup.+, P.sup.+, S.sup.+ and/or O.sup.+
atoms that are spaced by at least two substituted or unsubstituted
carbon atoms, preferably separated by 3 to 24, more preferably 3 to
6 carbon atoms. Preferred are di-quaternary ammonium compounds that
include two spaced positively charged atoms selected from N.sup.+,
P.sup.+, S.sup.+, O.sup.+ or a combination of any two or more. When
dissolved in water and/or an organic solvent, an anion may
dissociate from the multi-charged spacing/coupling agent compound
leaving a multi-charged cation molecule having at least two
positively charged atoms selected from nitrogen, phosphorus,
sulfur, and/or oxygen, the positively charged atoms spaced by two
or more carbon atoms; the multi-charged onium ion preferably having
a positively charged atom disposed on opposite ends of a
di-positively charged onium ion spacing/coupling agent intercalant
molecule.
[0024] "Co-intercalation" shall mean a process for forming an
intercalate by intercalation of a multi-charged spacing/coupling
agent and, at the same time or separately, co-intercalation of an
oligomer or polymer, or intercalation of co-intercalant
polymerizable monomers capable of reacting or polymerizing to form
a polymer.
[0025] "Concentrate" shall mean an intercalate formed by
intercalation of a multi-charged spacing/coupling agent and a
co-intercalant polymer, said intercalate combined with a matrix
polymer, in an intercalate concentration greater than needed to
improve one or more properties of the matrix polymer, so that the
concentrate can be mixed with additional matrix polymer to form a
nanocomposite composition or a commercial article.
[0026] "Intercalating Carrier" shall mean a carrier comprising
water and/or an organic solvent used with the multi-charged onium
ion spacing/coupling agent and/or with the co-intercalant polymer
or co-intercalant polymerizable monomers or oligomers to form an
Intercalating Composition capable of achieving Intercalation of the
multi-charged onium ion spacing/coupling agent and, at the same
time or separately, intercalation of the co-intercalant polymer or
co-intercalant polymerizable monomers or oligomers between
platelets of the Layered Material.
[0027] "Intercalating Composition" or "Intercalant Composition"
shall mean a composition comprising a multi-charged onium ion
spacing/coupling agent, and/or an intercalant polymer or
intercalant polymerizable monomers or oligomers and a Layered
Material, with or without an Intercalating Carrier.
[0028] "Exfoliate" or "Exfoliated" shall mean individual platelets
of an Intercalated Layered Material, or tactoids or clusters of
individual platelets, e.g., 2-10 platelets, preferably 2-5
platelets, that are smaller in total thickness than the
non-exfoliated Layered Material, dispersed as individual platelets
or tactoids throughout a carrier material, such as water, a
polymer, an alcohol or glycol, or any other organic solvent, or
throughout a matrix polymer.
[0029] "Exfoliation" shall mean a process for forming an Exfoliate
from an Intercalate.
[0030] "Matrix Polymer" shall mean a thermoplastic or thermosetting
polymer that the Intercalate or Exfoliate is dispersed within to
improve the mechanical strength, thermal resistance, e.g., raise
the glass transition temperature (Tg), and/or the decrease gas
(O.sub.2) impermeability of the Matrix Polymer.
SUMMARY OF THE INVENTION
[0031] In brief, the present invention is directed to organoclays
or intercalated layered materials prepared by intercalation of a
multi-charged spacing/coupling agent between adjacent silicate
platelets of a swellable layered material and co-intercalates and
nanocomposite materials formed by co-intercalating monomer,
oligomer or polymer molecules between the spacing/coupling
agent-intercalated planar silicate layers or platelets of the
swellable layered material, such as a phyllosilicate, preferably a
smectite clay, such as sodium montmorillonite clay. The spacing of
adjacent layers of the layered material is expanded at least 3
.ANG., preferably at least about 5 .ANG. to at least about 10
.ANG., preferably to at least about 15 .ANG., usually about 15-30
.ANG. with the multi-charged onium ion spacing/coupling agent to
form the novel organoclays. The co-intercalation of a monomer,
oligomer or polymer (hereinafter sometimes collectively referred to
as "polymer") co-intercalant then increases the d-spacing of
adjacent layers to at least about 20 .ANG., preferably to about 25
.ANG. to about 35 .ANG., and up to about 300 .ANG., for use in
increasing the viscosity of organic liquids and, in a preferred
embodiment, for admixture with a matrix polymer to form a
nanocomposite material or composition.
[0032] The present invention is directed to a method of preparing
intercalated layered materials prepared by intercalation of a
multi-charged onium ion spacing/coupling agent and, in a preferred
embodiment, co-intercalating an oligomeric or polymeric
co-intercalant into the galleries of the layered material to form
intercalates or intercalate concentrate compositions for
incorporation into, as by direct compounding with a matrix polymer
melt, one or more matrix polymers.
[0033] The present invention also is directed to exfoliates
prepared from the intercalate or intercalate concentrate
compositions. The exfoliate can be prepared by diluting the
concentrate in a (or additional) matrix polymer, and then curing.
The presence of polymerizable monomer or oligomer or polymer in the
galleries of the layered materials makes the layered materials
compatible with a matrix polymer, when the intercalate is added to
additional matrix polymer that is the same as the monomer, oligomer
or polymer co-intercalated. When a polymer curing agent is added,
the layered materials may be exfoliated by virtue of an expanding,
polymerizing intercalated monomer or oligomer and resulting polymer
molecules dispersed between platelet layers, depending upon the
degree of polymerization achieved. The intercalates, and/or
exfoliated individual or tactoid layers of the layered materials,
will perform as a polymer reinforcement and molecule (gas) barrier
in a matrix polymer to improve the mechanical properties and
barrier properties, e.g., lower gas permeability and raise glass
transition temperature (Tg), of the matrix polymer. The exfoliate
also can be prepared by directly adding a curing agent to the
monomer-/oligomer-/or polymer-intercalated concentrate. The curing
agent will penetrate into the gallery region of the intercalate to
react with the polymerizable monomers, oligomers or polymers
previously co-intercalated in the interlayer gallery and form
uniformly dispersed platelets or multi-layer intercalates or
tactoids in a nanocomposite comprising the intercalate, and/or
exfoliate thereof, and a matrix polymer.
[0034] In another embodiment of the present invention, the
intercalate can be added into a polar organic compound or a polar
organic compound-containing composition carrier or organic solvent
to provide unexpectedly viscous carrier compositions, for delivery
of the carrier or solvent, or for administration of an active
compound that is dissolved or dispersed in the carrier or solvent.
Such compositions, especially the high viscosity gels, are
particularly useful for delivery of active compounds, such as
oxidizing agents for hair waving lotions, and drugs for topical
administration, since extremely high viscosities are obtainable;
and for admixtures of the intercalate, or exfoliate thereof, with
polar solvents in modifying rheology, e.g., of cosmetics, oil-well
drilling fluids, paints, lubricants, especially food grade
lubricants, in the production of lubricants, grease, and the like.
Such intercalates and/or exfoliates also are especially useful in
admixture with matrix thermoplastic or thermosetting polymers in
the manufacture of nanocomposites for forming polymeric
articles.
[0035] The intercalate-containing and/or exfoliate-containing
organic liquid compositions can be in the form of a stable
thixotropic gel that is not subject to phase separation and can be
used to deliver any active materials, such as in the cosmetic, hair
care and pharmaceutical industries. The layered material is
intercalated by contact with a multi-charged spacing/coupling agent
to form the novel organoclays. Simultaneous or later addition of a
co-intercalant oligomer or polymer to the onium ion-intercalated
layered material, such as by direct compounding in an extruder to
co-intercalate the oligomer or polymer between adjacent spaced
phyllosilicate platelets and optionally separate (exfoliate) the
layered material into individual platelets, provides the
co-intercalated layered material for admixture with a matrix
polymer to form a nanocomposite composition.
[0036] Addition of the co-intercalate to a matrix polymer melt
enhances one or more properties of the matrix polymer melt, such as
strength or temperature resistance, and particularly gas
impermeability; or mixing the intercalate or co-intercalate with a
carrier or solvent material maintains and/or increases viscosity
and thixotropy of the carrier material. The intercalates and
co-intercalates of the present invention are easily, homogeneously
and uniformly dispersed throughout the carrier or solvent to
achieve new and unexpected viscosities in the carrier/platelet
compositions even after addition of an active organic compound,
such as a cosmetic component or a medicament, for administration of
the active organic compound(s) from the composition. The
co-intercalates of the present invention are easily, homogeneously
and uniformly dispersed in a matrix polymer to provide new and
unexpected gas barrier and strength properties to matrix polymers.
The above and other aspects and advantages of the present invention
will become more apparent from the following detailed description
of the present invention, taken in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIGS. 1A-1D are schematic side views of a portion of a
Layered Material platelet showing two adjacent exchangeable
Na.sup.+ cations on the platelet surface and negative charge
centers above the platelet surface directly under the Na.sup.+
cations, showing the negative charges diffusing radially outwardly
from the negative charge center, and showing di-positively charged
onium ions, with different length spacing moieties bonded between
the two positively charged (N.sup.+) atoms ion-exchanged at
different locations with respect to the negative charge centers.
FIG. 1A schematically shows a layered material platelet having a
cationic charge density such that negative charge centers, and the
corresponding associated cations (Na.sup.+) are spaced a distance
L. As shown in FIGS. 1B, 1C and 1D, multi-charged onium ions are
able to ion exchange with the Na.sup.+ cations at both adjacent
Na.sup.+ ions, while having carbon spacing molecules R.sub.1,
R.sub.2, and R.sub.3 of differing lengths, due to the negative
change occupying a substantial radial distance of about 5 .ANG.
from the negative charge center (R.sub.1,
<R.sub.3=L<R.sub.2)- . Accordingly, the distance between the
two positively charged atoms of the multi-charged onium ions
ideally differ depending upon the charge density of the layered
material.
[0038] FIGS. 2A and 2B are schematic representations of layered
material platelets intercalated with single-charged (tallow amine)
and di-charged (tallow diamine) onium ions; and
[0039] FIGS. 3A and 3B are schematic representations of adjacent
layered material platelets intercalated with single- and
double-charged onium ions, as in FIGS. 2A and 2B, and
co-intercalated with a polymer co-intercalant.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] To form the intercalated and exfoliated materials of the
present invention, the layered material, e.g., the phyllosilicate,
should be swelled or intercalated by sorption of a multi-charged
spacing/coupling agent to form the organoclays of the present
invention. To form the co-intercalated materials of the preferred
nanocomposite embodiment of the present invention, the
multi-charged onium ion-intercalated layered material is
simultaneously or subsequently co-intercalated with a
co-intercalant polymerizable monomer, polymerizable oligomer, or
polymer.
[0041] Useful multi-charged spacing/coupling agents include for
example, tetra-, tri-, and di-onium species such as tetra-ammonium,
tri-ammonium, and di-ammonium (primary, secondary, tertiary, and
quaternary), -phosphonium, -oxonium, or -sulfonium derivatives of
aliphatic, aromatic or arylaliphatic amines, phosphines, esters,
alcohols and sulfides. Illustrative of such materials are di-onium
compounds of the formula:
R.sup.1--X.sup.+--R--Y.sup.+
[0042] where X.sup.+ and Y.sup.+, same or different, are ammonium,
sulfonium, phosphonium, or oxonium radicals such as
.sup..+-.NH.sub.3, .sup..+-.NH.sub.2--, .sup..+-.N(CH.sub.3).sub.3,
.sup..+-.N(CH.sub.3).sub- .2--,
.sup..+-.N(CH.sub.3).sub.2(CH.sub.2CH.sub.3), .sup..+-.N(CH.sub.3)
(CH.sub.2CH.sub.3)--, .sup..+-.S(CH.sub.3).sub.3,
.sup..+-.S(CH.sub.3).su- b.2--, .sup..+-.P(CH.sub.3).sub.3,
.sup..+-.P(CH.sub.3).sub.2--, .sup..+-.NH.sub.4,
.sup..+-.NH.sub.3--, and the like; R is an organic spacing,
backbone radical, straight or branched, preferably having from 2 to
24, more preferably 3 to 10 carbon atoms, in a backbone organic
spacing molecule covalently bonded at its ends to charged N.sup.+,
P.sup.+, S.sup.+ and/or O.sup.+ cations and R.sup.1 can be
hydrogen, or an alkyl radical of 1 to 22 carbon atoms, linear or
branched, preferably having at least 6 carbon atoms. Examples of R
include substituted or unsubstituted alkylene, cycloalkenylene,
cycloalkylene, arylene, alkylarylene, either unsubstituted or
substituted with amino, alkylamino, dialkylamino, nitro, azido,
alkenyl, alkoxy, cycloalkyl, cycloalkenyl, alkanoyl, alkyylthio,
alkyl, aryloxy, arylalkylamino, alkylamino, arylamino,
dialkylamino, diarylamino, aryl, alkylsufinyl, aryloxy,
alkylsulfinyl, alkylsulfonyl, arylthio, arylsulfinyl,
alkoxycarbonyl, arylsulfonyl, or alkylsilane. Examples of R.sup.1
include non-existent; H; alkyl having 1 to 22 carbon atoms,
straight chain or branched; cycloalkenyl; cycloalkyl; aryl;
alkylaryl, either unsubstituted or substituted or substituted with
amino, alkylamino, dialkylamino, nitro, azido, alkenyl, alkoxy,
cycloalkyl, cycloalkenyl, alkanoyl, alkylthio, alkyl, aryloxy,
arylalkylamino, alkylamino, arylamino, dialkylamino, diarylamino,
aryl, alkylsufinyl, aryloxy, alkylsulfinyl, alkylsulfonyl,
arylthio, arylsulfinyl, alkoxycarbonyl, arylsulfonyl, or
alkylsilane. Illustrative of useful R groups are alkylenes, such as
methylene, ethylene, octylene, nonylene, tert-butylene,
neopentylene, isopropylene, sec-butylene, dodecylene and the like;
alkenylenes such as 1-propenylene, 1-butenylene, 1-pentenylene,
1-hexenylene, 1-heptenylene, 1-octenylene and the like;
cycloalkenylenes such as cyclohexenylene, cyclopentenylene and the
like; alkanoylalkylenes such as butanoyl octadecylene, pentanoyl
nonadecylene, octanoyl pentadecylene, ethanoyl undecylene,
propanoyl hexadecylene and the like; alkylaminoalkylenes, such as
methylamino octadecylene, ethylamino pentadecylene, butylamino
nonadecylene and the like; dialkylaminoalkylene, such as
dimethylamino octadecylene, methylethylamino nonadecylene and the
like; arylaminoalkylenes such as phenylamino octadecylene,
p-methylphenylamino nonadecylene and the like;
diarylaminoalkylenes, such as diphenylamino pentadecylene,
p-nitrophenyl-p'-methylphenylamino octadecylene and the like;
alkylarylaminoalkylenes, such as 2-phenyl-4-methylamino
pentadecylene and the like; alkylsulfinylenes, alkylsulfonylenes,
alkylthio, arylthio, arylsulfinylenes, and arylsulfonylenes such as
butylthio octadecylene, neopentylthio pentadecylene, methylsulfinyl
nonadecylene, benzylsulfinyl pentadecylene, phenylsulfinyl
octadecylene, propylthiooctadecylene, octylthio pentadecylene,
nonylsulfonyl nonadecylene, octylsulfonyl hexadecylene, methylthio
nonadecylene, isopropylthio octadecylene, phenylsulfonyl
pentadecylene, methylsulfonyl nonadecylene, nonylthio
pentadecylene, phenylthio octadecylene, ethyltio nonadecylene,
benzylthio undecylene, phenethylthio pentadecylene, sec-butylthio
octadecylene, naphthylthio undecylene and the like;
alkoxycarbonylalkylenes such as methoxycarbonylene,
ethoxycarbonylene, butoxycarbonylene and the like; cycloalkylenes
such as cyclohexylene, cyclopentylene, cyclo-octylene,
cycloheptylene and the like; alkoxyalkylenes such as
methoxy-methylene, ethoxymethylene, butoxymethylene,
propoxyethylene, pentoxybutylene and the like; aryloxyalkylenes and
aryloxyarylenes such as phenoxyphenylene, phenoxymethylene and the
like; aryloryalkylenes such as phenoxydecylene, phenoxyoctylene and
the like; arylalkylenes such as benzylene, phenthylene,
8-phenyloctylene, 10-phenyldecylene and the like; alkylarylenes
such as 5 3-decylphenylene, 4-octylphenylene, 4-nonylphenylene and
the like;
[0043] and polypropylene glycol and polyethylene glycol
substituents such as ethylene, propylene, butylene, phenylene,
benzylene, tolylene, p-styrylene, p-phenylmethylene, octylene,
dodecylene, octadecylene, methoxy-ethylene, moieties of the formula
--C.sub.3H.sub.6COO--, --C.sub.5H.sub.10COO--,
--C.sub.7H.sub.10COO--, --C.sub.7H.sub.14COO--,
--C.sub.9H.sub.18COO--, --C.sub.11H.sub.22COO--,
--C.sub.13H.sub.26COO--, --C.sub.13H.sub.26COO--, and
--C.sub.17H.sub.34COO-- and
--C.dbd.C(CH.sub.3)COOCH.sub.2CH.sub.2--, and the like. Such
tetra-, tri-, and di-ammonium, -sulfonium, -phosphonium, -oxonium;
ammonium/sulfonium; ammonium/phosphonium; ammonium/oxonium;
phosphonium/oxonium; sulfonium/oxonium; and sulfonium/phosphonium
radicals are well known in the art and can be derived from the
corresponding amines, phosphines, alcohols or ethers, and
sulfides.
[0044] Sorption of the multi-charged spacing/coupling agent should
be sufficient to achieve expansion of the interlayer spacing of
adjacent platelets of the layered material (when measured dry) to
at least about 10 .ANG., preferably to at least about 15 .ANG., and
intercalation of both the multi-charged spacing/coupling agent and
co-intercalant polymer should achieve an interlayer spacing to at
least about 20 .ANG., preferably to at least about 25 .ANG., up to
about 300 .ANG., usually up to about 100 .ANG..
[0045] The multi-charged spacing/coupling agent is introduced into
the layered material galleries in the form of a solid or liquid in
an intercalating composition containing the layered material (neat
or aqueous, with or without an organic solvent, e.g., an aliphatic
hydrocarbon, such as heptane, to, if necessary, aid to dissolve the
multi-charged onium ion compound) having a multi-charged
spacing/coupling agent concentration of at least about 2%,
preferably at least about 5% by weight multi-charged
spacing/coupling agent, more preferably at least about 50% to about
200% by weight multi-charged spacing/coupling agent in the
intercalating composition, based on the dry weight of the layered
material, for multi-charged onium ion spacing/coupling agent
sorption and ion-exchange.
[0046] In the preferred embodiment, the layered material, e.g.,
smectite clay, is slurried in water and the multi-charged
spacing/coupling agent (multi-charged cation) is dissolved in the
clay slurry water, preferably at a molar ratio of multi-charged
onium ion to clay interlayer cations of at least about 0.25:1,
preferably at least about 0.5:1, more preferably at a molar ratio
of at least about 1:1. The multi-charged spacing/coupling
agent-intercalated clay then is separated from the water easily,
since the layered material, e.g., clay, is now hydrophobic, and
dried in an oven to less than 5% water, based on the dry weight of
the layered material, preferably bone dry, before being compounded
with the co-intercalant polymer and before compounding with a
matrix polymer--preferably the same matrix polymer as the
co-intercalant polymer.
[0047] The multi-charged spacing/coupling agent compound can be
added as a solid with the addition to the layered
material/multi-charged spacing/coupling agent compound blend of at
least about 20% water, preferably at least about 30% water or more,
based on the dry weight of layered material. Preferably about 30%
to about 50% water, more preferably about 30% to about 40% water,
based on the dry weight of the layered material, is included in the
multi-charged spacing/coupling agent compound intercalating
composition, so that less water is sorbed by the intercalate,
thereby necessitating less drying energy after multi-charged
spacing/coupling agent compound intercalation.
[0048] The preferred multi-charged spacing/coupling agent compounds
are multi-onium ion compounds that include at least two positively
charged atoms, each (same or different) selected from primary,
secondary, tertiary or quaternary ammonium, phosphonium, sulfonium,
and/or oxonium ions having Formula 1, as follows: 1
[0049] wherein R is an alkylene, aralkylene or substituted alkylene
charged atom spacing moiety, preferably ranging from C.sub.3 to
C.sub.24, more preferably about C.sub.3 to C.sub.6 for relatively
high charge density (150 milliequivalents/100 grams C.E.C. to 70
milliequivalents/100 grams C.E.C.) layered materials; and
preferably from C.sub.6 to C.sub.12 for medium to low charge
density (70 milliequivalents/100 grams C.E.C. to 30
milliequivalents/100 grams C.E.C.) layered materials. R can be
straight or branched chain, including mixtures of such moieties,
i.e., C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, C.sub.8,
C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13, C.sub.14,
C.sub.15, C.sub.16, C.sub.17, C.sub.18, C.sub.19, C.sub.20,
C.sub.21, C.sub.22, C.sub.23 and C.sub.24, alone or in any
combination; and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are
moieties, same or different, selected from the group consisting of
hydrogen, alkyl, aralkyl, benzyl, substituted benzyl, e.g.,
straight or branched chain alkyl-substituted and
halogen-substituted; ethoxylated or propoxylated alkyl; ethoxylated
or propoxylated benzyl, e.g., 1-10 moles of ethoxylation or 1-10
moles of propoxylation. Z.sup.1 and Z.sup.2, same or different, may
be non-existent, or may be any of the moieties described for
R.sub.1, R.sub.2, R.sub.3 and R.sub.4. Also, one or both of Z.sup.1
and Z.sup.2 may include one or more positively charged atoms or
onium ions.
[0050] Prior art organoclays used to intercalate clays have only
been used with single-charged ammonium or phosphonium ions. The
present invention discloses the first organoclay composition which
uses multi-charged, preferably double-charged cationic onium ions,
to prepare organoclays. In particular, the composition of the
present invention is more suitable for polymer-clay nanocomposite
preparation, such as in-reactor route and direct compounding route.
The multi-charged cationic surfactants (onium ions that have at
least 1 radical bonded to one of the charged atoms that has a
length of at least C.sub.6 up to about C.sub.24) are preferred and
are commercially available at a very reasonable cost, and can
provide complete ion-exchange for the interlayer cations using much
less onium ion material, leaving more room for co-intercalation of
a polymer, as shown in Table I.
1 TABLE I Load in Chemical MW Charge Nanomer (wt %) Tallow Amine
(TA) 265 Mono 26.5 Tallow Diamine (TDA) 330 Dual 18.8 E185 480 Mono
40.0 EDT3 480 Dual 25.0
[0051] The above dual-charged onium ion-intercalated organoclays of
the present invention have been prepared by the di-charged onium
ion-exchange reaction process. Surprisingly, both of the charged
atoms of the tallow diamine intercalant ion-exchanged on the same
platelet surface of the smectite clay and did not bridge between
adjacent platelet surfaces. To achieve the full advantage of the
present invention, the distance between at least two of the spaced
charged atoms of the multi-charged onium ions should be in the
range (within about 6 .ANG.) of the average distance between two
exchangeable cations or adjacent negative charges on the clay
platelet surface. For example, the average area occupied by a
negative charge of a montmorillonite clay with a C.E.C. of 140
milleq./100 g is in the range of 70-80 .ANG..sup.2. Therefore, the
average distance of the adjacent charge is in the range of 8-9
.ANG.. The distance between the two charged ammonium groups in
tallow diamine, wherein the two charged nitrogen atoms (N.sup.+)
are spaced by three carbon atoms, is about 8 .ANG.. 2
[0052] The two charged amine groups of a tallow diamine molecule,
therefore, are each disposed within about 6 .ANG. of a negative
charge center when each replaces an adjacent exchangeable cation
(in this case, each N.sup.+ is within about 1 .ANG. of a negative
charge center) on the same silicate platelet surface, with the
tallow (R) radical extending upwardly from the platelet surface, as
shown in FIGS. 2A, 2B, 3A and 3B.
[0053] FIGS. 3A and 3B shows the schematic difference between
organoclays prepared by using single, and double-charged onium
ions. The hydrophobic (tallow) tails of the double-charged
surfactants will allow intercalation of oligomer and polymer guest
molecules to intercalate into the clay galleries just like the
single-charged onium ion-exchanged organoclays. The degree of
intercalation of the co-intercalant polymer molecules into the
single- or double-onium ion organoclay galleries can be assumed to
be the same, based on the fact, which is the controlling factor in
intercalation, that the chain length of both intercalants is the
same. However, due to the fact that the number of long (tallow)
tails of the di-charged onium ions is reduced to 50%, the volume
occupied by the co-intercalant polymer molecules will be
substantially increased, as shown schematically in FIGS. 3A and
3B.
[0054] Examples of the preferred commercially available
multi-charged onium surfactants include the following:
[0055] Tallow Diamine (TDA) Duoquad T50 (T50)
[0056] R--HN.sup.+--CH.sub.2CH.sub.2CH.sub.2N.sup.+H.sub.2; 3
[0057] E--DT--3, or Ethoduomeen T13 (E-DT-3) 4
[0058] DA-16/18
[0059]
R--O----CH.sub.2CH.sub.2CH.sub.2--HN.sup.+--CH.sub.2CH.sub.2CH.sub.-
2N.sup.+H.sub.2;
[0060] Tallow Triamine (T3)
[0061]
R--HN.sup.+--CH.sub.2CH.sub.2CH.sub.2N.sup.+H--CH.sub.2CH.sub.2CH.s-
ub.2N.sup.+H.sub.2; and
[0062] Tallow Tetramine (T4)
[0063]
R--HN.sup.+--CH.sub.2CH.sub.2CH.sub.2N.sup.+H--CH.sub.2CH.sub.2CH.s-
ub.2N.sup.+H--CH.sub.2CH.sub.2CH.sub.2N.sup.+H.sub.2
[0064] wherein R.dbd.C.sub.14-C.sub.18 alkyl chain.
[0065] The results of intercalation of monomers and polymers to the
multi-charged onium ion-exchanged organoclay indicate that there is
no locking of the adjacent clay silicate layers by using
multi-charged onium ion intercalants.
[0066] Any swellable layered material that sufficiently sorbs the
multi-charged onium ion spacing/coupling agent to increase the
interlayer spacing between adjacent phyllosilicate platelets at
least 3.ANG., preferably at least 5.ANG., to at least about 10
.ANG., preferably to at least about 15 .ANG. can be used in the
practice of this invention. Useful swellable layered materials
include phyllosilicates, such as smectite clay minerals, e.g.,
montmorillonite, particularly sodium montmorillonite; magnesium
montmorillonite and/or calcium montmorillonite; nontronite;
beidellite; volkonskoite; hectorite; saponite; sauconite;
sobockite; stevensite; svinfordite; vermiculite; and the like.
Other useful layered materials include micaceous minerals, such as
illite and mixed layered illite/smectite minerals, such as
rectorite, tarosovite, ledikite and admixtures of illites with the
clay minerals named above.
[0067] Preferred swellable layered materials are phyllosilicates of
the 2:1 type having a negative charge on the layers ranging from
about 0.15 to about 0.9 charges per formula unit and a commensurate
number of exchangeable metal cations in the interlayer spaces. Most
preferred layered materials are smectite clay minerals such as
montmorillonite, nontronite, beidellite, volkonskoite, hectorite,
saponite, sauconite, sobockite, stevensite, and svinfordite.
[0068] As used herein the "interlayer spacing" or "interlaminar
spacing" refers to the distance between the internal faces of the
adjacent layers as they are assembled in the layered material
before any delamination (exfoliation) takes place.
[0069] The amount of multi-charged spacing/coupling agent
intercalated into the swellable layered materials, in order that
the intercalated layered material platelet surfaces sufficiently
ion-exchange with the multi-charged spacing/coupling agent
molecules such that adjacent platelets of the layered material may
be sufficiently spaced for easy co-intercalation of a polymeric or
polymerizable co-intercalant, may vary substantially between about
2%, preferably at least about 10%, and up to about 200%, based on
the dry weight of the layered material.
[0070] The multicharged onium ion spacing/coupling agent
intercalant and co-intercalant polymer may be introduced into
(sorbed within) the interlayer spaces of the layered material in a
number of ways. In a preferred method of intercalating the
multi-charged onium ion spacing/coupling agent between adjacent
platelets of the layered material, the layered material is slurried
in water, e.g., at 5-20% by weight layered material and 80-95% by
weight water, and the multi-charged spacing/coupling agent compound
is dissolved or dispersed in the water in which the layered
material is slurried. If necessary, the multi-charged
spacing/coupling agent compound can be dissolved first in an
organic solvent, e.g., propanol. The layered material then is
separated from the slurry water and dried prior to compounding with
the co-intercalant polymer for intercalation of the co-intercalant
and to form the nanocomposite material in a matrix polymer,
preferably the same matrix polymer as the co-intercalant polymer.
In a preferred method of intercalating the co-intercalant as an
oligomer or polymer, the multi-charged spacing/coupling
agent-intercalated layered material is intimately mixed with the
co-intercalant oligomer or polymer melt, e.g., by extrusion or pug
-milling, to form an intercalating composition comprising the
multi-charged spacing/coupling agent-intercalated layered material
and co-intercalant oligomer or polymer.
[0071] The resulting multi-charged spacing/coupling agent
intercalated layered material has interior platelet surfaces that
are sufficiently hydrophobic and sufficiently spaced for
intercalation of the co-intercalant polymer. The multi-charged
spacing/coupling agent carrier (preferably water, with or without
an organic solvent) can be added by first solubilizing or
dispersing the multi-charged spacing/coupling agent compound in the
carrier; or a dry multi-charged spacing/coupling agent compound and
relatively dry layered material (preferably containing at least
about 4% by weight water) can be blended and the intercalating
carrier added to the blend, or to the layered material prior to
adding the dry multi-charged spacing/coupling agent. When
intercalating the layered material with multi-charged
spacing/coupling agent in slurry form (e.g., 900 pounds water, 100
pounds layered material, 100 pounds, multi-charged spacing/coupling
agent compound, the amount of water can vary substantially, e.g.,
from about 4% by weight, preferably from a minimum of at least
about 30% by weight water, with no upper limit to the amount of
water in the intercalating composition (the intercalate is easily
separated from the intercalating composition due to its
hydrophobicity after multi-charged spacing/coupling agent
intercalation).
[0072] Alternatively, the multi-charged spacing/coupling agent
intercalating carrier, e.g., water, with or without an organic
solvent, can be added directly to the layered material, i.e., the
phyllosilicate, prior to adding the multi-charged spacing/coupling
agent compound, either dry or in solution. Sorption of the
multi-charged spacing/coupling agent compound molecules may be
performed by exposing the layered material to a dry or liquid
multi-charged spacing/coupling agent compound in the multi-charged
spacing/coupling agent intercalating composition.
[0073] In accordance with another method of intercalating the
multi-charged spacing/coupling agent and co-intercalant between the
platelets of the layered material, the layered material, preferably
containing at least about 4% by weight water, e.g., about 10% to
about 15% by weight water, is blended with water and/or organic
solvent solution of a multi-charged spacing/coupling agent
compound. The multi-charged spacing/coupling agent compound can be
intercalated into the layered material simultaneously with the
intercalation of a co-intercalant polymer, or the co-intercalant
polymer may be intercalated after intercalation of the
multi-charged spacing/coupling agent. The dry multi-charged
spacing/coupling agent intercalated layered material then is
extruded with the co-intercalant oligomer or polymer melt for
direct compounding, with intercalation of the co-intercalant
polymer into the multi-charged spacing/coupling agent-intercalated
layered material.
[0074] The multi-charged spacing/coupling agents have an affinity
for the phyllosilicate at both, properly spaced, charged atoms to
bridge adjacent negative charge sites on a platelet surface so that
the multi-charged spacing/coupling agents are sorbed onto a single
platelet surface, and are maintained bonded to the inner surfaces
of the silicate platelets, in the interlayer spaces, after
exfoliation.
[0075] It is preferred that the intercalate loading be less than
about 10% for purposes of increasing the viscosity of an organic
liquid carrier. Intercalate loadings within the range of about
0.05% to about 40% by weight, preferably about 0.5% to about 20%,
more preferably about 1% to about 10% significantly enhances
viscosity. In general, the amount of intercalate and/or exfoliated
particles thereof incorporated into a liquid carrier, such as a
polar solvent, e.g., a glycol such as glycerol, is less than about
90% by weight of the mixture, and preferably from about 0.01% to
about 80% by weight of the composite material mixture, more
preferably from about 0.05% to about 40% by weight of the mixture,
and most preferably from about 0.05% to about 20% or 0.05% to about
10% by weight.
[0076] In accordance with a preferred embodiment of the present
invention, the co-intercalated layered material can be
co-intercalated with any oligomer or polymer and then dispersed
into one or more melt-processible thermoplastic and/or
thermosetting matrix oligomers or polymers, or mixtures thereof, by
direct compounding. Matrix polymers for use in this embodiment of
the process of this invention may vary widely, the only requirement
is that they are melt processible. In this embodiment of the
invention, the polymer includes at least ten (10), preferably at
least thirty (30) recurring monomeric units. The upper limit to the
number of recurring monomeric units is not critical, provided that
the melt index of the matrix polymer is such that the matrix
polymer forms a flowable mixture. Most preferably, the matrix
polymer is intercalated into the di-charged spacing/coupling
agent-intercalated layered material simultaneously with dispersing
the co-intercalated polymer uniformly into the matrix polymer. The
matrix polymer preferably includes from at least about 10 to about
100 recurring monomeric units, and preferably is the same oligomer
or polymer as the co-intercalant. In the most preferred embodiments
of this invention, the number of recurring units is such that the
matrix polymer has a melt index of from about 0.01 to about 12
grams per 10 minutes at the processing temperature.
[0077] MXD6 nylon, obtained from Mitsubishi Gas Chemical Company,
Inc., Tokyo, Japan is a polymer having the following Formula 2:
5
[0078] wherein n for the monomer=1;
[0079] n for the oligomer=2-10; and
[0080] n for the polymer=11-20,000,
[0081] preferably 11-1,000,
[0082] more preferably 11-500.
[0083] Other thermoplastic resins and rubbers for use as matrix
monomers, oligomers or polymers in the practice of this invention
may vary widely. Illustrative of useful thermoplastic resins, which
may be used alone or in admixture, are polyactones such as
poly(pivalolactone), poly(caprolactone) and the like; polyurethanes
derived from reaction of diisocyanates such as 1,5-naphthalene
diisocyanate; p-phenylene diisocyanate, m-phenylene diisocyanate,
2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate,
3,3'-dimethyl-4,4'-biphenyl diisocyanate,
4,4'-diphenylisopropylidene diisocyanate,
3,3'-dimethyl-4,4'-diphenyl diisocyanate,
3,3'-dimethyl-4,4'-diphenylmeth- ane diisocyanate,
3,3'-dimethoxy-4,4'-biphenyl diisocyanate, dianisidine
diisocyanate, toluidine diisocyanate, hexamethylene diisocyanate,
4,4'-diisocyanatodiphenylmethane and the like and linear long-chain
diols such as poly(tetramethylene adipate), poly(ethylene adipate),
poly(1,4-butylene adipate), poly(ethylene succinate),
poly(2,3-butylene succinate), polyether diols and the like;
polycarbonates such as poly[methane bis(4-phenyl) carbonate],
poly[1,1-ether bis(4-phenyl) carbonate], poly[diphenylmethane
bis(4-phenyl)carbonate], poly[1,1-cyclohexane
bis(4-phenyl)carbonate] and the like; polysulfones; polyethers;
polyketones; polyamides such as poly(4-amino butyric acid),
poly(hexamethylene adipamide), poly(6-aminohexanoic acid),
poly(m-xylylene adipamide), poly(p-xylylene sebacamide),
poly(2,2,2-trimethyl hexamethylene terephthalamide),
poly(metaphenylene isophthalamide) (NOMEX), poly(p-phenylene
terephthalamide) (KEVLAR), and the like; polyesters such as
poly(ethylene azelate), poly(ethylene-1,5-naphthalate,
poly(1,4-cyclohexane dimethylene terephthalate), poly(ethylene
oxybenzoate) (A-TELL), poly(para-hydroxy benzoate) (EKONOL),
poly(1,4-cyclohexylidene dimethylene terephthalate) (KODEL) (cis),
poly(1,4-cyclohexylidene dimethylene terephthalate) (KODEL)
(trans), polyethylene terephthalate, polybutylene terephthalate and
the like; poly(arylene oxides) such as
poly(2,6-dimethyl-1,4-phenylen- e oxide),
poly(2,6-diphenyl-1,4-phenylene oxide) and the like; poly(arylene
sulfides) such as poly(phenylene sulfide) and the like;
polyetherimides; vinyl polymers and their copolymers such as
polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride; polyvinyl
butyral, polyvinylidene chloride, ethylene-vinyl acetate
copolymers, and the like; polyacrylics, polyacrylate and their
copolymers such as polyethyl acrylate, poly(n-butyl acrylate),
polymethylmethacrylate, polyethyl methacrylate, poly(n-butyl
methacrylate), poly(n-propyl methacrylate), polyacrylamide,
polyacrylonitrile, polyacrylic acid, ethylene-acrylic acid
copolymers, ethylene-vinyl alcohol copolymers acrylonitrile
copolymers, methyl methacrylate-styrene copolymers, ethylene-ethyl
acrylate copolymers, methacrylated butadiene-styrene copolymers and
the like; polyolefins such as low density poly(ethylene),
poly(propylene), chlorinated low density poly(ethylene),
poly(4-methyl-l-pentene), poly(ethylene), poly(styrene), and the
like; ionomers; poly(epichlorohydrins); poly(urethane) such as the
polymerization product of diols such as glycerin,
trimethylol-propane, 1,2,6-hexanetriol, sorbitol, pentaerythritol,
polyether polyols, polyester polyols and the like with a
polyisocyanate such as 2,4tolylene diisocyanate, 2,6-tolylene
diisocyante, 4,4'-diphenylmethane diisocyanate, 1 ,6-hexamethylene
diisocyanate, 4,4'-dicyclohexyl-methane diisocyanate and the like;
and polysulfones such as the reaction product of the sodium salt of
2,2-bis(4-hydroxyphenyl) propane and 4,4'-dichlorodiphenyl sulfone;
furan resins such as poly(furan); cellulose ester plastics such as
cellulose acetate, cellulose acetate butyrate, cellulose propionate
and the like; silicones such as poly(dimethyl siloxane),
poly(dimethyl siloxane co-phenylmethyl siloxane), and the like;
protein plastics; and blends of two or more of the foregoing.
[0084] Vulcanizable and thermoplastic rubbers useful as matrix
polymers in the practice of this embodiment of the invention may
also vary widely. Illustrative of such rubbers are brominated butyl
rubber, chlorinate butyl rubber, polyurethane elastomers,
fluoroelastomers, polyester elastomers, polyvinylchloride,
butadiene/acrylonitrile elastomers, silicone elastomers,
poly(butadiene), poly(isobutylene), ethylene-propylene copolymers,
ethylene-propylene-diene terpolymers, sulfonated
ethylene-propylene-diene terpolymers, poly(chloroprene),
poly(2,3-dimethylbutadiene), poly(butadiene-pentadiene),
chlorosulphonated poly(ethylenes), poly(sulfide) elastomers, block
copolymers, made up of segments of glassy or crystalline blocks
such as poly(styrene), poly(vinyl-toluene), poly(t-butyl styrene),
polyesters and the like and the elastomeric blocks such as
poly(butadiene), poly(isoprene), ethylene-propylene copolymers,
ethylene-butylene copolymers, polyether and the like as for example
the copolymers in poly(styrene)-poly(butadiene)-poly(styrene) block
copolymer manufactured by Shell Chemical Company under the trade
name KRATON.RTM..
[0085] Useful thermosetting resins useful as matrix polymers
include, for example, the polyamides; polyalkylamides; polyesters;
polyurethanes; polycarbonates; polyepoxides; and mixtures
thereof.
[0086] Most preferred thermoplastic polymers for use as a matrix
polymer are thermoplastic polymers such as polyamides, particularly
nylons, most particularly MXD6 nylon. Polyamides which may be used
as matrix polymers in the process of -the present invention are
synthetic linear polycarbonamides characterized by the presence of
recurring carbonamide groups as an integral part of the polymer
chain which are separated from one another by at least two carbon
atoms. Polyamides of this type include polymers, generally known in
the art as nylons, obtained from diamines and dibasic acids having
the recurring unit represented by the general formula:
--NHCOR.sup.13COHNR.sup.14--
[0087] in which R.sup.13 is an alkylene group of at least 2 carbon
atoms, preferably from about 2 to about 11; or arylene having at
least about 6 carbon atoms, preferably about 6 to about 17 carbon
atoms; and R.sup.14 is selected from R.sup.13 and aryl groups.
Also, included are copolyamides and terpolyamides obtained by known
methods, for example, by condensation of hexamethylene diamine or
meta-xylylene diamine and a mixture of dibasic acids consisting of
terephthalic acid and adipic acid. Polyamides of the above
description are well-known in the art and include, for example, the
copolyamide of 30% hexamethylene diammonium isophthalate and 70%
hexamethylene diammonium adipate, poly(hexamethylene adipamide)
(nylon 6,6), poly(hexamethylene sebacamide) (nylon 6, 10),
poly(hexamethylene isophthalamide), poly(hexamethylene
terephthalamide), poly(heptamethylene pimelamide) (nylon 7,7),
poly(octamethylene sebacamide) (nylon 8,8), poly(nonamethylene
azelamide) (nylon 9,9) poly(decamethylene azelamide) (nylon 10,9),
poly(decamethylene sebacamide) (nylon 10,10), poly[bis(4-amino
cyclohexyl)methane-1,10-decan- e-carboxamide)], poly(m-xylylene
adipamide), poly(p-xylylene sebacamide), poly(2,2,2-trimethyl
hexamethylene terephthalamide), poly(piperazine sebacamide),
poly(p-phenylene terephthalamide), poly(metaphenylene
isophthalamide) and the like.
[0088] Other useful polyamides for use as a matrix polymer are
those formed by polymerization of amino acids and derivatives
thereof, as, for example, lactams. Illustrative of these useful
polyamides are poly(4-aminobutyric acid) (nylon 4),
poly(6-aminohexanoic acid) (nylon 6), poly(7-aminoheptanoic acid)
(nylon 7), poly(8-aminooctanoic acid) (nylon 8), poly(9-10
aminononanoic acid) (nylon 9), poly(10-aminodecanoic acid) (nylon
10), poly(11-aminoundecanoic acid) (nylon 11),
poly(12-aminododecanoic acid) (nylon 12) and the like.
[0089] Other matrix or host polymers which may be employed in
admixture with the di-charged spacing/coupling agent intercalant
and co-intercalant polymer of the present invention to form
nanocomposites are linear polyesters. The type of polyester is not
critical and the particular polyesters chosen for use in any
particular situation will depend essentially on the physical
properties and features, i.e., tensile strength, modulus and the
like, desired in the final form. Thus, a multiplicity of linear
thermoplastic polyesters having wide variations in physical
properties are suitable for use in admixture with exfoliated
layered material platelets in manufacturing nanocomposites in
accordance with this invention.
[0090] The particular polyester chosen for use as a matrix polymer
can be a homo-polyester or a copolyester, or mixtures thereof, as
desired. Polyesters are normally prepared by the condensation of an
organic dicarboxylic acid and an organic diol, and, the reactants
can be added to the intercalates, or exfoliated intercalates for in
situ polymerization of the polyester while in contact with the
layered material, before or after exfoliation of the
intercalates.
[0091] Polyesters which are suitable for use as matrix polymers in
this embodiment of the invention are those which are derived from
the condensation of aromatic, cycloaliphatic, and aliphatic diols
with aliphatic, aromatic and cycloaliphatic dicarboxylic acids and
may be cycloaliphatic, aliphatic or aromatic polyesters.
[0092] Exemplary of useful cycloaliphatic, aliphatic and aromatic
polyesters which can be utilized as matrix polymers in the practice
of this embodiment of the invention are poly(ethylene
terephthalate), poly(cyclohexylenedimethylene terephthalate),
poly(ethylene dodecate), poly(butylene terephthalate),
poly[ethylene(2,7-naphthalate)], poly(methaphenylene isophthalate),
poly(glycolic acid), poly(ethylene succinate), poly(ethylene
adipate), poly(ethylene sebacate), poly(decamethylene azelate),
poly(decamethylene adipate), poly(decamethylene sebacate),
poly(dimethylpropiolactone), poly(para- hydroxybenzoate) (EKONOL),
poly(ethylene oxybenzoate) (A-tell), poly(ethylene isophthalate),
poly(tetramethylene terephthalate, poly(hexamethylene
terephthalate), poly(decamethylene terephthalate), poly(l
,4-cyclohexane dimethylene terephthalate) (trans), poly(ethylene
1,5-naphthalate), poly(ethylene 2,6-naphthalate),
poly(1,4-cyclohexyliden- e dimethylene terephthalate), (KODEL)
(cis), and poly(1,4-cyclohexylidene dimethylene terephthalate
(KODEL) (trans).
[0093] Polyester compounds prepared from the condensation of a diol
and an aromatic dicarboxylic acid are especially suitable as matrix
polymers in accordance with this embodiment of the present
invention. Illustrative of such useful aromatic carboxylic acids
are terephthalic acid, isophthalic acid and a o-phthalic acid,
1,3-naphthalene-dicarboxylic acid, 1,4-naphthalenedicarboxylic
acid, 2,6-naphthalenedicarboxylic acid,
2,7-naphthalene-dicarboxylic acid, 4,4'-diphenyldicarboxylic acid,
4,4'-diphenylsulfone-dicarboxylic acid,
1,1,3-trimethyl-5carboxy-3-(p-car- boxyphenyl)-idane, diphenyl
ether 4,4'-dicarboxylic acid, bis-p(carboxy-phenyl) methane and the
like. Of the aforementioned aromatic dicarboxylic acids, those
based on a benzene ring (such as terephthalic acid, isophthalic
acid, orthophthalic acid) are preferred for use in the practice of
this invention. Among these preferred acid precursors, terephthalic
acid is particularly preferred acid precursor.
[0094] Still other useful thermoplastic homopolymers and copolymer
matrix polymers for forming nanocomposites with the co-intercalated
layered materials of the present invention are polymers formed by
polymerization of alpha-beta-unsaturated monomers or the
formula:
R.sup.15R.sup.16C.dbd.CH.sub.2
[0095] wherein:
[0096] R.sup.15 and R.sup.16 are the same or different and are
cyano, phenyl, carboxy, alkylester, halo, alkyl, alkyl substituted
with one or more chloro or fluoro, or hydrogen. Illustrative of
such preferred homopolymers and copolymers are homopolymers and
copolymers of ethylene, propylene, vinyl alcohol, acrylonitrile,
vinylidene chloride, esters of acrylic acid, esters of methacrylic
acid, chlorotrifluoroethylene, vinyl chloride and the like.
Preferred are poly(propylene), propylene copolymers, poly(ethylene)
and ethylene copolymers. More preferred are poly(ethylene) and
poly(propylene).
[0097] The mixture may include various optional components which
are additives commonly employed with polar organic liquids. Such
optional components include nucleating agents, fillers,
plasticizers, impact modifiers, chain extenders, plasticizers,
colorants, mold release lubricants, antistatic agents, pigments,
fire retardants, and the like. These optional components and
appropriate amounts are well known to those skilled in the art.
[0098] The amount of intercalated layered material included in the
liquid carrier or solvent compositions to form the viscous
compositions suitable to deliver the carrier or some
carrier-dissolved or carrier-dispersed active material, such as a
pharmaceutical, may vary widely depending on the intended use and
desired viscosity of the composition. For example, relatively
higher amounts of intercalates, i.e., from about 10% to about 30%
by weight of the total composition, are used in forming solvent
gels having extremely high viscosities, e.g., 5,000 to 5,000,000
centipoises. Extremely high viscosities, however, also can be
achieved with a relatively small concentration of intercalates
and/or exfoliates thereof, e.g., 0.1% to 5% by weight, by adjusting
the pH of the composition in the range of about 0-6 or about 10-14
and/or by heating the composition above room temperature, e.g., in
the range of about 25.degree. C. to about 200.degree. C.,
preferably about 75.degree. C. to about 100.degree. C. It is
preferred that the intercalate or platelet loading-be less than
about 10% by weight of the composition. Intercalate or platelet
particle loadings within the range of about 0.01% to about 40% by
weight, preferably about 0.05% to about 20%, more preferably about
0.5% to about 10% of the total weight of the composition
significantly increases the viscosity of the composition. In
general, the amount of intercalate and/or platelet particles
incorporated into the carrier/solvent is less than about 20% by
weight of the total composition, and preferably from about 0.05% to
about 20% by weight of the composition, more preferably from about
0.01% to about 10% by weight of the composition, and most
preferably from about 0.01% to about 5%, based on the total weight
of the composition.
[0099] In accordance with an important feature of the present
invention, the intercalate and/or platelet/carrier compositions of
the present invention can be manufactured in a concentrated form,
e.g., as a master gel, e.g, having about 10-90%, preferably about
20-80% intercalate and/or exfoliated platelets of layered material
and about 10-90%, preferably about 20-80% carrier/solvent. The
master gel can be later diluted and mixed with additional carrier
or solvent to reduce the viscosity of the composition to a desired
level.
[0100] In one embodiment, the intercalates, and/or exfoliates
thereof, are mixed with a carrier or solvent to produce viscous
compositions of the carrier or solvent optionally including one or
more active compounds, such as an antiperspirant compound,
dissolved or dispersed in the carrier or solvent.
[0101] When shear is employed for exfoliation, any method which can
be used to apply a shear to the intercalate/matrix polymer
nanocomposite composition can be used. The shearing action can be
provided by any appropriate method, as for example by mechanical
means, by thermal shock, by pressure alteration, or by ultrasonics,
all known in the art. In particularly useful procedures, the
composition is sheared by mechanical methods in which the
intercalate, with or without the carrier or solvent, is sheared by
use of mechanical means, such as stirrers, Banbury.RTM. type
mixers, Brabender.RTM. type mixers, long continuous mixers, and
extruders. Another procedure employs thermal shock in which
shearing is achieved by alternatively raising or lowering the
temperature of the composition causing thermal expansions and
resulting in internal stresses which cause the shear. In still
other procedures, shear is achieved by sudden pressure changes in
pressure alteration methods; by ultrasonic techniques in which
cavitation or resonant vibrations which cause portions of the
composition to vibrate or to be excited at different phases and
thus subjected to shear. These methods of shearing are merely
representative of useful methods, and any method known in the art
for shearing intercalates may be used.
[0102] Mechanical shearing methods may be employed such as by
extrusion, injection molding machines, Banbury.RTM. type mixers,
Brabender.RTM. type mixers and the like. Shearing also can be
achieved by introducing the layered material and intercalant
monomer at one end of an extruder (single or double screw) and
receiving the sheared material at the other end of the extruder.
The temperature of the layered material/intercalant monomer
composition, the length of the extruder, residence time of the
composition in the extruder and the design of the extruder (single
screw, twin screw, number of flights per unit length, channel
depth, flight clearance, mixing zone, etc.) are several variables
which control the amount of shear to be applied for
exfoliation.
[0103] In accordance with an important feature of the present
invention, it has been found that the multi-charged
spacing/coupling agent-intercalated clay can be co-intercalated
with an oligomer or polymer by direct compounding, i.e., by mixing
the multi-charged onium ion-intercalated clay directly with the
co-intercalant oligomer or polymer in an extruder to make the
co-intercalated clay without significant exfoliation of the clay
platelets. The co-intercalate-filled matrix polymer extrudes into a
homogeneous transparent film with excellent dispersion of the
co-intercalate, and/or exfoliate thereof. The co-intercalate,
and/or exfoliate thereof, dispersed within the matrix polymer may
be predominantly in the form of multi-layer tactoids dispersed in
the matrix polymer. The tactoids have the thickness of at least two
individual platelet layers plus the ion-exchanged di-charged
intercalant spacing/coupling agent and one to five monolayer
thicknesses of the co-intercalant polymer, and include small
multiples or aggregates of less than about 10 platelets, in a
coplanar aggregate, preferably less than about 5, more preferably
less than about 3 platelet layers, still more preferably 2 or 3
platelet layers having the multi-charged spacing/coupling agent
compound and co-intercalant polymer between platelet surface(s).
The nanocomposite compositions, including the matrix polymer, can
include the layered material as all intercalates, completely
without exfoliation, while maintaining transparency, excellent
intercalate dispersibility, and excellent gas impermeability.
[0104] Molding compositions comprising a matrix polymer containing
a desired loading of the co-intercalates of the present invention,
and/or individual platelets obtained from exfoliation of the
co-intercalates manufactured according to the present invention,
are outstandingly suitable for the production of sheets, films and
panels having valuable properties. Such sheets, films and panels
may be shaped by conventional processes such as vacuum processing
or by hot pressing to form useful objects. The sheets and panels
according to the invention are also suitable as coating materials
for other materials comprising, for example, wood, glass, ceramic,
metal or other plastics, and outstanding strengths can be achieved
using conventional adhesion promoters, for example, those based on
vinyl resins. Beverage containers, e.g., plastic beer/wine bottles
having new and unexpected shelf life are possible using matrix
polymers filled with, e.g., 1-10% by weight of the co-intercalates
of the present invention, either as a sole layer, or secured to or
between one or more other layers, as known in the art. The sheets,
films and panels can be laminated to other plastic films, sheets or
panels and this is preferably effected by co-extrusion, the sheets
being bonded in the molten state. The surfaces of the sheets, films
and panels, including those in the embossed form, can be improved
or finished by conventional methods, for example by lacquering or
by the application of protective films.
[0105] Matrix polymer/intercalate composite materials are
especially useful for fabrication of extruded films and film
laminates, as for example, films for use in food packaging that
have low O.sub.2 permeabilities. Such films can be fabricated using
conventional film extrusion techniques. The films are preferably
from about 10 to about 100 microns, more preferably from about 20
to about 100 microns and most preferably from about 25 to about 75
microns in thickness.
[0106] The homogeneously distributed intercalate, and/or exfoliated
platelets thereof, which has been co-intercalated in accordance
with the present invention, and a matrix polymer can be formed into
a film by suitable film-forming methods. Typically, the composition
is melted and forced through a film forming die after oligomer or
polymer co-intercalation and compounding. The film of the
nanocomposite may go through sequential steps to cause the
intercalate and/or exfoliated platelets thereof to be further
oriented so the major planes through the co-intercalates and/or
platelets thereof are substantially parallel to the major plane
through the film. One method to accomplish this is to biaxially
stretch the film. For example, the film is stretched in the axial
or machine direction by tension rollers pulling the film as it is
extruded from the die. The film is simultaneously stretched in the
transverse direction by clamping the edges of the film and drawing
them apart. Alternatively, the film is stretched in the transverse
direction by using a tubular film die and blowing the film up as it
passes from the tubular film die. The films may exhibit one or more
of the following benefits in addition to decreased permeability to
gases, particularly O.sub.2: increased modulus; increased wet
strength; increased dimensional stability; and decreased moisture
adsorption.
[0107] The following examples are presented to more particularly
illustrate the invention and are not to be construed as limiting
the scope of the invention.
EXAMPLE 1
[0108] This example demonstrates the formation of a double-charged
onium ion-modified (organophilic) montmorillonite clay. The onium
ion is a neutral amine (primary and secondary) and can be
protonated by contact with HCl.
[0109] One hundred grams of Na-montmorillonite clay (PGW)
commercially available from Nanocor, Inc. (Arlington Heights, Ill.)
was dispersed in 3 liters of de-ionized water by mechanical paddle
mixer or colloidal mill. The clay dispersion was heated to
75.degree. C. to 80.degree. C. 26.4 g of Tallow di-amine, available
from Tomah Products, was mixed with 70 ml, 2 N HCl in 1 liter of
75.degree. C. to 80.degree. C. de-ionized water. The amine-HCl
solution was introduced to the clay dispersion, followed by
vigorous mixing. The mixture was maintained at 75.degree. C. to
80.degree. C. for about 30 min., followed by a de-watering process,
such as filtration. The filter cake was re-dispersed into 4 liters
of 75.degree. C. to 80.degree. C. water and the solid (filter cake)
was collected and placed into a 75.degree. C. to 80.degree. C. oven
to dry followed by particle size reduction. The filter cake also
can be freeze-dried. The dried material has a d001 spacing of 17
.ANG. as measured by X-ray diffraction and was coded as TDA-2H-PGW.
Tallow amine also can be used to prepare treated montmorillonite
with essentially the same procedure, but with a higher amount of
Tallow amine, e.g., 37.1 grams. The product is coded as TA-PGW,
with a d001 spacing of 22 .ANG..
EXAMPLE 2
[0110] This example demonstrates the formation of a double-charged
onium-ion modified (organophilic) montmorillonite clay. The onium
ion is a neutral amine (tertiary) and can be protonated with
contact with HCl.
[0111] One hundred grams of Na-montmorillonite clay (PGW)
commercially available from Nanocor, Inc. (Arlington Heights, Ill.)
was dispersed in 3 liters of de-ionized water by mechanical paddle
mixer or colloidal mill. The clay dispersion was heated to
75.degree. C. to 80.degree. C. 33.6 g of E-DT-3 amine, available
from Tomah Products, was mixed with 70 ml, 2 N HCl in 1 liter of
75.degree. C. to 80.degree. C. de-ionized water. The amine-HCl
solution was introduced to the clay dispersion, followed by
vigorous mixing. The mixture was maintained at 75.degree. C. to
80.degree. C. for about 30 min., followed by a de-watering process,
such as filtration. The filter cake was re-dispersed into 4 liters
of 75.degree. C. to 80.degree. C. water and the solid (filter cake)
was collected and placed into a 75.degree. C. to 80.degree. C. oven
to dry followed by particle size reduction. The filter cake also
can be freeze-dried. The dried material has a d001 spacing of 17
.ANG. as measured by X-ray diffraction and was coded as
E-TD-3-2H-PGW.
EXAMPLE 3
[0112] This example demonstrates the formation of a double-charged
onium ion-modified (organophilic) montmorillonite clay. The onium
ion is a double-charged quaternary ammonium cation.
[0113] One hundred grams of Na-montmorillonite clay (PGW)
commercially available from Nanocor, Inc. (Arlington Heights, Ill.)
was dispersed in 3 liters of de-ionized water by mechanical paddle
mixer or colloidal mill. The clay dispersion was heated to
75.degree. C. to 80.degree. C. 67.2 g of DuoquadT50 (50% solid),
available from Akzo Nobel, was mixed with 1 liter of 75.degree. C.
to 80.degree. C. de-ionized water. The T50 solution was introduced
to the clay dispersion followed by vigorous mixing. The mixture was
maintained at 75.degree. C. to 80.degree. C. for about 30 min.,
followed by a de-watering process, such as filtration. The filter
cake was re-dispersed into 4 liters of 75.degree. C. to 80.degree.
C. water and the solid was collected and placed into a 75.degree.
C. to 80.degree. C. oven to dry followed by particle size
reduction. The filter cake also can be freeze-dried. The dried
material has a d001 spacing of 19 .ANG. as measured by X-ray
diffraction and was coded as T50-PGW.
EXAMPLES 4-6
[0114] These examples illustrate the formation of clay intercalates
by combining the multi-charged onium ion-modified (organophilic)
clays with non-polymeric organic compounds.
[0115] 5 grams of the products of Examples 1-3, TDA-2H-PGW, TA-PGW,
E-DT-3-2H-PGW, and T50-PGW were mixed with 45 grams of the
following non-polymeric organic compounds, .epsilon.-caprolactam at
70.degree. C. to 90.degree. C., DGEBA DER331 at 70.degree. C. to
80.degree. C. and Resorcinol bis- (diphenyl phosphate) (RDP, Akzo
Nobel) at 70.degree. C. to 80.degree. C. The mixtures were cooled
to room temperature and placed on a microscopic glass slide to
measure X-ray diffraction patterns. The results are given in the
Table 1. The intercalates of the multi-charged onium ion-treated
clay with the non-polymeric organic compounds also can be formed by
mixing the non-polymeric organic compounds with the filter cake
followed by de-watering, drying and particle size reduction. The
d001 results are nearly identical to the results generated from
dispersion route of Examples 1-3. The results in Table 1 indicate
successful intercalation of non-polymeric organic compounds into
the interlayer spacing of the multi-charged onium ion-treated
clays. The multi-charged onium ion-treated clays perform similarly
to the normal organoclays. The long aliphatic tails (C.sub.6+) of
the preferred multi-charged onium ions provide exceptional degrees
of intercalation.
2TABLE 1 d.sub.001 results of the multi-charged onium ion-modified
clays dispersed in nonpolymeric organic compounds by X-ray
diffraction. d.sub.001 (.ANG.) d.sub.001 (.ANG.) d.sub.001 (.ANG.)
Ex- d.sub.001 (.ANG.) in in in amples Clays clay caprolactam DER331
RDP 4 TDA-2H-PGW 16 33 34 34 4 TA-PGW 22 32 36 33 5 E-DT-3-2H-PGW
18 33 38 35 6 T50-PGW 19 32 36 34 Comp- PGW 13 13 13 13 arative
1
COMPARATIVE EXAMPLE 1
[0116] For comparison, 5 grams of the untreated Na-montmorillonite
clay (PGW) was mixed with the above-mentioned non-polymeric organic
compounds, and its mixtures were examined by X-ray diffraction. The
result is included in Table 1. No intercalation of the organic
molecules was observed.
EXAMPLES 7-9
[0117] These examples illustrate the formation of a polymer-clay
nanocomposite by melt compounding.
[0118] Melt compounding was used to prepare polymer clay
nanocomposites. Thermoplastic resins, Nylon6 (PA6), Poly methyl
methacrylate (PMMA) and Nylon MXD6 (MXD6) were selected as the
matrices. Resin pellets and multi-charged onium ion-intercalated
clay were fed into a twin screw extruder (Leistritz Micro27) at
elevated temperatures (above the melting points of the resins),
e.g., for PMMA the temperatures of the extruder zones were in the
range of 210.degree. C. to 230.degree. C. The ratio of the
multi-charged onium ion-intercalated clays to the resins were
controlled at 5:95 by weight. The compounded composite strings from
the extruder were cooled in a cold water bath prior to being
pelletized. The nanocomposite of PA6, and MXD6 were cast to 2
mil-thick films and OTR (Oxygen Transmittance Rate) results were
measured at 65% RH at 23.degree. C. by using a Mocon OX-Tran2/20.
PMMA-clay nanocomposites were molded into ASTM standard testing
specimens to test HDT (Heat Deflection Temperature). The dispersion
results of the multi-charged onium ion-treated clays in the
above-mentioned resins are listed in Table 2. X-ray diffraction
patterns were obtained from the PA6-clay, MXD6-clay film
nanocomposites and PMMA-clay nanocomposite bar. The X-ray
diffraction results are shown in Table 3.
3TABLE 2 The observation of the clay dispersion of the
multi-charged onium ion-treated clays and Na-montmorillonite clay
(PGW) in Nylon6 (PA6), Poly (methyl methacrylate) (PMMA) and Nylon
MXD6 (MXD6). Examples Clays PA6 PMMA MXD6 7 TDA-2H-PGW excellent
excellent excellent 8 E-DT-3-2H-PGW very good excellent excellent 9
T50-PGW very good very good excellent Comparative PGW poor poor
poor 2 Excellent: The extruded pellets and cast films are almost
transparent and no particles were observed by optical microscope at
.times.100. Very good: The extruded pellets and cast films are
slightly opaque and no particles were observed by optical
microscope at .times.100. Good: The extruded pellets and cast films
are opaque and gel-body like particles were observed by optical
microscope at .times.100. Poor: The pellets have visible particles,
and are hazy. The film cast from the pellets have a visible
discontinues phase and voids.
[0119] The melted resin polymers are intercalated into the
multi-charged onium ion-treated clays to form resin-clay
nanocomposites in the extrusion process. The X-ray diffraction
results indicate that the original clay layer stacking has been
interrupted by the resin intercalation. The OTR results of the PA6,
and MXD6 nanocomposites have more than 30% reduction compared with
the unfilled resins, respectively. The HDT of the PMMA
nanocomposite increases nearly 10.degree. C. over the pure PMMA
resin.
4TABLE 3 d.sub.001 results of nanocomposite containing the
multi-charged onium ion-treated clays dispersed in thermoplastic
resins through melt compounding by X-ray diffraction. d.sub.001
(.ANG.) d.sub.001 (.ANG.) d.sub.001 (.ANG.) d.sub.001 (.ANG.)
Examples Clays clay in PA6 in PMMA in MXD6 7 TDA-2H-PGW 16 >31
32 >33 8 E-DT-3-2H-PGW 18 >30 33 >32 9 T50-PGW 19 >34
34 >33 Comp- PGW 13 11 12 11 arative 2
Comparative Example 2
[0120] For comparison, 5 wt % of the untreated Na-montmorillonite
clay (PGW) was compounded with Nylon6 (PA6), Poly (methyl
methacrylate) (PMMA) and Nylon MXD6 (MXD6) using the same
conditions as for the multi-charged onium ion-treated clays. The
resins filled with untreated PGW have very poor dispersion (Table
2). The cast films have visible voids, and the molded sample bars
have rough surfaces and clay aggregates. The X-ray diffraction
results (Table 3) indicate no intercalation of polymer resins into
the clay interlayer spacing. Also, the dehydration (drying) of the
clay collapsed the clay galleries in the heated extrusion
process.
Example 10
[0121] This example illustrates the formation of a
Nylon6-TDA-2H-PGW nanocomposite through a caprolactam
polymerization route.
[0122] 70 g of TDA-2H-PGW was mixed with 2,000 grams of caprolactam
at 80.degree. C. overnight, prior to being placed into a reactor.
The reactor is equipped with constant speed pedal mixer and purged
with nitrogen. The reaction time is 12 hr. at 260.degree. C. The
reaction product was broken into small pieces with liquid nitrogen
cooling and washed in boiling water to remove residual caprolactam.
A 2 mil-thick film was cast and OTR was measured on the Mocon
OX-Tran 2/20. The nanocomposite containing TA-PGW was prepared by
the same method. The comparison of OTR results of the unfilled
resin and nanocomposites is shown in Table 4.
5TABLE 4 Comparison of OTR of Nylon6-clay nanocomposites prepared
with traditional onium ion-treated clay (TA-PGW) and the
multi-charged onium ion-treated clay (TDA-2H-PGW). OTR Sample Name
Clay, wt % (cc-mil/100 in.sup.2/day) % change Control 0.0 3.24 100%
TA-PGW 2.0 2.11 -35% TDA-2H-PGW 2.4 1.40 -57%
[0123] The nanocomposite prepared from the multi-charged onium
ion-treated clay has significantly reduced oxygen permeability
compared with the traditional (single charged onium ion) treated
clay. Also, other mechanical, thermal and solvent resistance
properties are better than those of the nanocomposites prepared
from the traditional single charged onium ion-treated clays.
* * * * *