U.S. patent application number 15/357879 was filed with the patent office on 2017-03-09 for co-agglomerated latex polymer dispersions and methods of preparing and using same.
This patent application is currently assigned to BASF SE. The applicant listed for this patent is BASF SE. Invention is credited to Kostas S. AVRAMIDIS, Koichi TAKAMURA.
Application Number | 20170066847 15/357879 |
Document ID | / |
Family ID | 42732085 |
Filed Date | 2017-03-09 |
United States Patent
Application |
20170066847 |
Kind Code |
A1 |
TAKAMURA; Koichi ; et
al. |
March 9, 2017 |
CO-AGGLOMERATED LATEX POLYMER DISPERSIONS AND METHODS OF PREPARING
AND USING SAME
Abstract
Co-agglomerated dispersions and methods for their preparation
are described herein. The co-agglomerated dispersions are prepared
by co-agglomerating an anionic polymer dispersion and inert
particles. The polymers for use in the co-agglomerated dispersions
are derived from one or more monomers including at least one
conjugated diene monomer. The inert particles have a particle size
of less than 2 .mu.m. Also described herein is an aqueous
dispersion including co-agglomerated particles formed from at least
one polymer and at least one inert material. Further described
herein are foamed polymers, latex-based adhesives, waterproofing
membranes, sound absorbing coatings, and methods for their
preparation and use.
Inventors: |
TAKAMURA; Koichi; (Penn
Valley, CA) ; AVRAMIDIS; Kostas S.; (Charlotte,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BASF SE |
Ludwigshafen |
|
DE |
|
|
Assignee: |
BASF SE
Ludwigshafen
DE
|
Family ID: |
42732085 |
Appl. No.: |
15/357879 |
Filed: |
November 21, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13379824 |
Dec 21, 2011 |
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PCT/EP2010/059327 |
Jul 1, 2010 |
|
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15357879 |
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61222700 |
Jul 2, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08K 3/346 20130101;
C08L 9/08 20130101; C08J 3/215 20130101; C08J 9/30 20130101; C08K
3/346 20130101; C08L 95/00 20130101; C09J 109/08 20130101; C09J
2409/00 20130101; C08J 9/0066 20130101; C08L 9/10 20130101; C08C
1/07 20130101; C09J 5/00 20130101; C08J 2309/08 20130101 |
International
Class: |
C08C 1/07 20060101
C08C001/07; C08J 9/00 20060101 C08J009/00; C08L 9/08 20060101
C08L009/08; C09J 5/00 20060101 C09J005/00; C08L 95/00 20060101
C08L095/00; C08J 9/30 20060101 C08J009/30; C09J 109/08 20060101
C09J109/08 |
Claims
1-25. (canceled)
26. An aqueous dispersion comprising co-agglomerated particles
formed of at least one polymer and at least one inert material,
said co-agglomerated particles having a particle size of 100 nm to
5 .mu.m and said polymer derived from one or more monomers
including at least one conjugated diene monomer.
27. The aqueous dispersion of claim 26, having a surface tension of
less than 45 mN/m.
28. The aqueous dispersion of claim 26, wherein the solids content
is greater than 50%.
29. The aqueous dispersion of claim 26, wherein the solids content
is greater than 60%.
30. The aqueous dispersion of claim 29, wherein the viscosity is
less than 1 Pas at 20.degree. C.
31. The aqueous dispersion of claim 26, wherein said at least one
inert material includes at least one inorganic material.
32. The aqueous dispersion of claim 31, wherein said inorganic
material includes one or more clays.
33. The aqueous dispersion of claim 31, wherein said inorganic
material includes one or more particles having platelet
structures.
34. The aqueous dispersion of claim 31, wherein said inorganic
material includes material selected from the group consisting of
kaolin, mica, bentonite, natural and synthetic hectorite,
ettringite, calcium phosphate, and mixtures thereof.
35. The aqueous dispersion of claim 34, wherein said inorganic
material includes kaolin.
36. The aqueous dispersion of claim 26, wherein the inert material
is present in the co-agglomerated particles in an amount of from 1%
to 20% by weight based on the dry weight of the polymer in the
co-agglomerated particles.
37. The aqueous dispersion of claim 26, further comprising a
cationic surfactant.
38. The aqueous dispersion of claim 26, wherein the polymer is
derived from one or more monomers, wherein at least 50% of the
monomers comprise the at least one conjugated diene.
39. The aqueous dispersion of claim 38, wherein the at least one
conjugated diene monomer includes butadiene.
40. The aqueous dispersion of claim 26, wherein the one or more
monomers include at least one vinyl aromatic monomer.
41. The aqueous dispersion of claim 40, wherein said at least one
vinyl aromatic monomer includes styrene.
42. The aqueous dispersion of claim 41, where said polymer is a
styrene-butadiene-based copolymer.
43. The aqueous dispersion of claim 26, wherein the one or more
monomers include at least one (meth)acrylic acid ester.
44. The aqueous dispersion of claim 43, wherein said at least one
(meth)acrylic acid ester includes methyl methacry late.
45. The aqueous dispersion of claim 26, wherein said polymer is
polybutadiene.
46. A foamed polymer comprising at least one polymer and at least
one inert material wherein the inert material is substantially
uniformly distributed throughout the foamed polymer, the foamed
polymer produced from co-agglomerated particles formed of the at
least one polymer and the at least one inert material having a
particle size of 100 nm to 5 .mu.m, wherein said at least one
polymer is derived from one or more monomers including at least one
conjugated diene monomer.
47. The foamed polymer of claim 46, wherein said at least one inert
material comprises at least one inorganic material.
48. A method for producing a foamed polymer, comprising:
co-agglomerating an anionic polymer dispersion, said polymer
derived from one or more monomers including at least one conjugated
diene monomer and in the presence of inert particles having a
particle size of less than 2 .mu.m to form a co-agglomerated
dispersion comprising the anionic polymer and particles;
introducing air or other gases into the polymer dispersion to form
a foamed dispersion; molding the foam dispersion; solidifying or
setting the foam dispersion to form the polymer foam; and
cross-linking the co-agglomerated particles in the polymer
foam.
49. The method of claim 48, further comprising the step of adding a
foaming agent to the co-agglomerated dispersion.
50. The method of claim 48, further comprising the step of adding a
gelling agent to the co-agglomerated dispersion.
51. The method of claim 48, wherein said inert particles comprise
inorganic particles.
52. A latex-based adhesive, comprising co-agglomerated particles
formed of at least one polymer and at least one inert material,
said co-agglomerated particles having a particle size of 100 nm to
5 .mu.m and said polymer derived from one or more monomers
including at least one conjugated diene monomer.
53. A method of adhering a substrate to a surface, comprising the
steps of: applying to a surface a co-agglomerated dispersion
comprising co-agglomerated particles formed of at least one polymer
and at least one inert material, said co-agglomerated particles
having a particle size of 100 nm to 5 .mu.m and said polymer
derived from one or more monomers including at least one conjugated
diene monomer; applying the substrate to the dispersion; and
removing water from the dispersion.
54. The method of claim 53, further comprising the steps of:
co-agglomerating an anionic polymer dispersion, said polymer
derived from one or more monomers including at least one conjugated
diene monomer and in the presence of inert particles having a
particle size of less than 2 .mu.m to form the co-agglomerated
dispersion.
55. The method of claim 53, further comprising the step of removing
water from the co-agglomerated dispersion prior to applying it to
the surface of the co-agglomerated dispersion.
56. A modified asphalt composition, comprising an asphalt emulsion
and a co-agglomerated dispersion comprising co-agglomerated
particles formed of at least one polymer and at least one inert
material, said co-agglomerated particles having a particle size of
100 nm to 5 .mu.m and said polymer derived from one or more
monomers including at least one conjugated diene monomer.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 13/379,824, filed on Dec. 21, 2011, which is a
national stage entry application of PCT/EP2010/059327, filed on
Jul. 1, 2010, the text of which is incorporated by reference, and
claims the benefit of priority from U.S. Provisional Application
No. 61/222,700, filed on Jul. 2, 2009, the entire contents of which
are incorporated herein by reference.
BACKGROUND
[0002] Latex polymers are useful in the production of several
products, including binders for filler particles in paper coating,
carpet backing, paints, foams, and adhesives. The mechanical
properties of these products can be improved through the addition
of inorganic materials to the dispersions or resultant products.
Typically, these inorganic materials are added to the dispersion
prior to being used in the resultant products. Although there have
been attempts to add the inorganic material during the
polymerization reaction to form a dispersion consisting of
polymer-inorganic hybrid particles, these processes have also
required difficult and time consuming treatment processes to use
the inorganic material during the polymerization process.
[0003] For example, clay-rubber nanocomposites have been developed
by various methods, including in-situ solution polymerization and
co-coagulating a rubber latex and a clay aqueous dispersion. In the
solution polymerization process, the polymer is dissolved into an
organic solvent, i.e. toluene. Separately, a clay that has been
modified to be organophilic is dispersed in another organic
solvent, i.e. alcohol. A desired amount of the clay dispersion is
poured into the polymer solution under agitation. The solution is
then dried under vacuum to remove the organic solvent to prepare
the polymer/clay composite.
[0004] In the co-coagulation method, a modified organophilic clay
is dispersed in water and added into the polymer dispersion
(latex). After vigorous stirring, the mixture is co-coagulated by
addition of the electrolyte solution (i.e. 2% sulfuric acid
solution). The resultant coagulum is washed with water and
dried.
[0005] In these processes, the clay surface needs to be pretreated
to be organophilic so the clay particles dispersed into the aqueous
phase of the polymer dispersion can be incorporated into the bulk
polymer phase to produce the clay/rubber polymer nanocomposite. One
drawback of these processes is that natural, hydrophilic clay
particles cannot be used. For example, in the co-coagulation
process, the natural, hydrophilic clay particles would simply
coagulate by themselves and form macroscopic separate phases during
the coagulation process. Furthermore, these processes produce dry
rubber solids which limit the industrial applications where these
nanocomposites can be used. These solids are especially difficult
to use in adhesives, foams, asphalt emulsions, and other
applications.
SUMMARY
[0006] Co-agglomerated dispersions and methods for their
preparation are described. The co-agglomerated dispersions are
prepared by co-agglomerating an anionic polymer dispersion and
inert particles. The polymers for use in the co-agglomerated
dispersions are derived from one or more monomers including at
least one conjugated diene monomer. The inert particles can have a
particle size of less than 2 .mu.m. In some embodiments, the inert
particles have a particle size ranging from 50 nm to 2 .mu.m. The
inert particles can be inorganic particles. For example, the
inorganic particles can include one or more clays. The inorganic
particles can include one or more particles having platelet
structures (e.g., kaolin, mica, bentonite, natural and synthetic
hectorite, ettringite, calcium phosphate, and mixtures thereof). In
some examples, the inorganic particles include kaolin. The inert
particles can be provided in a slurry.
[0007] The co-agglomerating step can further include providing the
inorganic particles in an amount of from 1% to 50% by weight based
on the dry weight of the polymer (e.g., 10% by weight based on the
dry weight of the polymer). The method can also include the step of
adding a cationic surfactant to the co-agglomerated dispersion to
make the polymer dispersion cationic.
[0008] The polymer for use in the methods described herein is
derived from one or more monomers, wherein at least 50% of the
monomers comprise the at least one conjugated diene. In some
examples, the at least one conjugated diene monomer includes
butadiene. The one or more monomers can include at least one vinyl
aromatic monomer (e.g., styrene). The one or more monomers can
include at least one (meth)acrylic acid ester (e.g., methyl
methacrylate). In some examples, the polymer is polybutadiene.
[0009] The methods described herein can further include the step of
polymerizing the one or more monomers using emulsion polymerization
to form the anionic polymer dispersion prior to the
co-agglomerating step. The polymerizing step can occur at a
temperature below room temperature. The methods described herein
can also include the step of removing water from the
co-agglomerated dispersion to produce a solids content of greater
than 50% (e.g., 50% to 75% or 55% to 72.5%) or greater than 60%
(e.g., 60%-70%).
[0010] The co-agglomerating step can include co-agglomerating the
anionic copolymer dispersion and the slurry using freeze
agglomeration, pressure agglomeration, mechanical agitation, by
adding a chemical to the anionic copolymer dispersion and the
slurry, or combinations of these methods. In some examples, the
co-agglomerating step results in a polymer dispersion wherein the
co-agglomerated particles have a particle size of 100 nm to 5
.mu.m.
[0011] Also described is an aqueous dispersion including
co-agglomerated particles formed of at least one polymer and at
least one inert material. The co-agglomerated particles have a
particle size of 100 nm to 5 .mu.m. The at least one polymer is
derived from one or more monomers including at least one conjugated
diene monomer. In some examples, the aqueous dispersion has a
surface tension of less than 45 mN/m. In some examples, the solids
content of the aqueous dispersion described herein is greater than
50% or greater than 60%. In some embodiments, the solids content is
greater than 60% and the viscosity is less than 1 Pas at 20.degree.
C.
[0012] The inert material of the aqueous dispersion described
herein can be an inorganic material, e.g., in the form of inorganic
particles. The inorganic material can include one or more clays.
The inorganic material can also include one or more particles
having platelet structures (e.g., kaolin, mica, bentonite, natural
and synthetic hectorite, ettringite, calcium phosphate, and
mixtures thereof). In some examples, the inorganic material
includes kaolin. The inert material is present in the
co-agglomerated particles in an amount of from 1% to 50% by weight,
based on the dry weight of the polymer in the co-agglomerated
particles. The aqueous anionic dispersion described herein can be
further transformed to a cationic dispersion by adding a cationic
surfactant and reducing the pH of the dispersion.
[0013] The polymer for use in the aqueous dispersions described
herein can be derived from one or more monomers, wherein at least
50% of the monomers comprise the at least one conjugated diene. In
some examples, the at least one conjugated diene monomer includes
butadiene. In some examples, the one or more monomers include at
least one vinyl aromatic monomer (e.g., styrene). In some examples,
the one or more monomers can include at least one (meth)acrylic
acid ester (e.g., methyl methacrylate). In some examples, the
polymer is polybutadiene.
[0014] Further described herein are foamed polymers, latex-based
adhesives, and methods for their preparation and use. Included
herein are foamed polymers, the foamed polymer comprising an
expanded foam produced from co-agglomerated particles formed of at
least one polymer and at least one inert material, the
co-agglomerated particles having a particle size of 100 nm to 5
.mu.m and the polymer derived from one or more monomers including
at least one conjugated diene monomer. The foamed polymer includes
a substantially uniform distribution of the inert material
throughout.
[0015] Also described herein is a method for producing a foamed
polymer, comprising co-agglomerating an anionic polymer dispersion,
the polymer derived from one or more monomers including at least
one conjugated diene monomer and in the presence of inert particles
having a particle size of less than 2 .mu.m to form a
co-agglomerated dispersion comprising the anionic polymer and
particles; introducing air or other gases into the polymer
dispersion to form a foamed dispersion; molding the foam
dispersion; solidifying or setting the foam dispersion to form the
polymer foam; and cross-linking the co-agglomerated particles in
the polymer foam.
[0016] Further described herein is a latex-based adhesive,
comprising co-agglomerated particles formed of at least one polymer
and at least one inert material, the co-agglomerated particles
having a particle size of 100 nm to 5 .mu.m and the polymer derived
from one or more monomers including at least one conjugated diene
monomer. In some examples, the adhesive described herein can be
used as a textile adhesive (e.g. a carpet adhesive). A method of
adhering a substrate to a surface is also described, and comprises
the steps of applying to a surface a co-agglomerated dispersion
comprising co-agglomerated particles formed of at least one polymer
and at least one inert material, the co-agglomerated particles
having a particle size of 100 nm to 5 .mu.m and the polymer derived
from one or more monomers including at least one conjugated diene
monomer; applying the substrate to the dispersion; and removing
water from the dispersion. The method can further include the steps
of co-agglomerating an anionic polymer dispersion, the polymer
derived from one or more monomers including at least one conjugated
diene monomer and in the presence of inert particles having a
particle size of less than 2 .mu.m to form the co-agglomerated
dispersion. Also, the method can include the step of removing water
from the co-agglomerated dispersion prior to applying it to the
surface.
[0017] In yet another aspect, a modified asphalt composition is
described comprising an asphalt emulsion and a co-agglomerated
dispersion comprising co-agglomerated particles formed of at least
one polymer and at least one inert material, said co-agglomerated
particles having a particle size of 100 nm to 5 .mu.m and said
polymer derived from one or more monomers including at least one
conjugated diene monomer. The asphalt emulsion can be used as a
waterproofing membrane or a sound absorbing coating.
[0018] The details of one or more embodiments of the invention are
set forth in the accompanying drawings and the description below.
Other features, objects, and advantages of the invention will be
apparent from the description and drawings, and from the
claims.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1A is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion with clay
co-agglomerated and a styrene-butadiene-based latex dispersion with
the post-addition of clay to the latex dispersion without
agglomeration.
[0020] FIG. 1B is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion without
clay and a styrene-butadiene-based latex dispersion with the
post-addition of clay.
[0021] FIG. 2 is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion without
clay and a styrene-butadiene-based latex dispersion with clay
co-agglomerated.
[0022] FIG. 3A is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion
co-agglomerated with 5% clay. The separate traces represent
independent trials.
[0023] FIG. 3B is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion
co-agglomerated with 10% clay. The separate traces represent
independent trials.
[0024] FIG. 4A is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion
co-agglomerated with clay after heat aging.
[0025] FIG. 4B is a photograph of a heat aged
styrene-butadiene-based latex dispersion latex film without clay
and styrene-butadiene-based latex dispersion latex films
co-agglomerated with clay.
[0026] FIG. 5 is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion without
clay and a styrene-butadiene-based latex dispersion co-agglomerated
with clay after heat aging.
[0027] FIG. 6 is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion with clay
co-agglomerated and a styrene-butadiene-based latex dispersion with
the post-addition of clay.
[0028] FIG. 7 is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion without
clay and styrene-butadiene-based latex dispersions co-agglomerated
with either clay or calcium carbonate.
[0029] FIG. 8 is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene-based latex dispersion without
clay, styrene-butadiene-based latex dispersions co-agglomerated
with clay, a styrene-butadiene-based latex dispersion with the clay
post-added, and a styrene-butadiene-based latex dispersion with
clay co-agglomerated and post-added.
[0030] FIG. 9 is a graph illustrating the tensile strength vs.
elongation of a styrene-butadiene latex dispersion co-agglomerated
with clay, a styrene-butadiene-based latex dispersion with the clay
post-added, and a styrene-butadiene-based latex dispersion with
clay co-agglomerated and post-added after heat aging.
[0031] FIG. 10 is a graph illustrating the lap shear of an adhesive
without clay, an adhesive with the post-addition of clay, and an
adhesive co-agglomerated with clay.
[0032] FIG. 11 is a graph illustrating the lap shear of an adhesive
without clay, an adhesive with the post-addition of clay, and an
adhesive co-agglomerated with clay after heat aging.
DETAILED DESCRIPTION
[0033] Co-agglomerated latex polymer dispersions and methods for
their preparation are described herein. The method for producing
the co-agglomerated dispersion includes co-agglomerating an anionic
polymer dispersion in the presence of inert particles having a
particle size of less than 2 .mu.m to form a co-agglomerated
dispersion comprising the anionic polymer and particles.
[0034] The inert particles useful in the co-agglomerated
dispersions described herein do not react with the polymer in the
dispersion. For example, the inert particles described herein do
not include sulfur which can react with the polymer in the
dispersion in a vulcanization reaction. The inert particles useful
in the co-agglomerated dispersions described herein can be
inorganic particles and can include one or more clays. In addition,
the inorganic particles described herein can include one or more
particles having platelet structures, including, for example,
kaolin, mica, bentonite, natural and synthetic hectorite (e.g.
LAPONITE.RTM., a synthetic hectorite commercially available from
Rockwood Additives Limited, Cheshire, United Kingdom), ettringite,
calcium phosphate, and mixtures thereof. Other particles can also
be used in the invention such as tungsten oxide, carbon black,
carbon nanoparticles, and calcium carbonate. The inert particles
can have a particle size ranging from 50 nm to 2 .mu.m.
[0035] The inert particles described herein can be added to the
dispersion in solid form or provided in a slurry. In some
embodiments, the slurry can have greater than 40% solids. Examples
of the amount of inert particles present in the slurry described
herein include greater than 45%, greater than 50%, greater than
55%, greater than 60%, greater than 65%, greater than 70%, or
greater than 75%. Exemplary slurries include Kaolin HT (70% solids)
and MIRAGLOSS 91.RTM. slurries, commercially available from BASF
Corporation, Engelhard Division.
[0036] The inert particles for the co-agglomeration step can be
provided in an amount of from about 1% to about 50% by weight based
on the dry weight of the polymer. Further examples include from
about 1.2% to about 40%, about 1.4% to about 35%, about 1.6% to
about 30%, about 1.8% to about 25% by weight, about 2% to about 20%
by weight, or about 3% to about 15%, or about 4% to about 12% (e.g.
5% or 10%) by weight based on the dry weight of the polymer.
[0037] The anionic polymer for use in the co-agglomerated
dispersions described herein is derived from one or more monomers
including at least one conjugated diene monomer (e.g. isoprene or
1,3-butadiene). In some examples, at least 50% of the monomers
comprise the at least one conjugated diene. For example, 55%, 60%,
65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% of the monomers can
include the at least one conjugated diene. In some examples, the at
least one conjugated diene monomer includes butadiene
(1,3-butadiene). The polymer described herein can be a
butadiene-based copolymer derived from one or more additional
monomers or can be polybutadiene.
[0038] As mentioned above, the polymer can be derived from one or
more monomers in addition to the conjugated diene (e.g. butadiene).
In some embodiments, the one or more monomers include at least one
vinyl aromatic monomer such as styrene, .alpha.-methylstyrene,
o-chlorostyrene, and vinyltoluenes (e.g., styrene). For example,
the polymer can be a styrene-butadiene-based copolymer derived from
styrene, butadiene and optionally other monomers. The
styrene-butadiene-based copolymer can include greater than 0% to
less than 50% styrene and greater than 50% to less than 100%
butadiene (e.g. 10-45% styrene/55-90% butadiene, 15-40%
styrene/60-85% butadiene, e.g. 20-35% styrene/65-80% butadiene, or
about 25% styrene/about 75% butadiene (by weight). The
styrene-butadiene-based copolymer can include up to 25% additional
monomers such as itaconic acid, (meth)acrylic acid, (meth)acrylic
acid esters, (meth)acrylonitrile, and (meth)acrylamide.
[0039] In some embodiments, the one or more additional monomers can
include at least one (meth)acrylic acid or (meth)acrylic acid ester
in addition to or instead of the at least one vinyl aromatic
monomer. For example, methyl, ethyl, n-butyl, isobutyl and
2-ethylhexyl acrylates and methacrylates can be used. In some
embodiments, methyl methacrylate is used to form the polymer. The
polymer can include methyl methacrylate as a substitute for all or
a portion of the styrene in the percentages provided in the
previous paragraph. For example, the polymer can be derived from
greater than 50% to 99% butadiene and 1% to less than 50% methyl
methacrylate or 1% to less than 50% styrene. In some embodiments
the polymer can be derived from greater than 50%-99% butadiene,
1-49% methyl methacrylate and 1-49% styrene. In some embodiments,
the T.sub.g of the polymer is greater than -80.degree. C. and less
than -10.degree. C.
[0040] In addition, small amounts (e.g. from 0.01 to 1% by weight
based on the total monomer weight) of molecular weight regulators,
such as tert-dodecyl mercaptan. Such substances are preferably
added to the polymerization zone in a mixture with the monomers to
be polymerized and are considered part of the total amount of
unsaturated monomers used in the copolymer.
[0041] The one or more monomers are polymerized to form the anionic
polymer dispersion for use in the co-agglomerated dispersions
described herein. In some examples, the one or more monomers are
polymerized using emulsion polymerization to form the anionic
polymer dispersion prior to the co-agglomerating step. The
polymerizing step can occur at a temperature below room
temperature. The polymer dispersion can have an average particle
size of 200 nm or less or 100 nm or less (e.g. 20-100 nm).
[0042] The co-agglomeration of the anionic polymer dispersion and
the inert particles can be carried out in a variety of ways known
to those of skill in the art. The co-agglomerating step can include
co-agglomerating the anionic copolymer dispersion and the slurry
using, for example, freeze agglomeration, pressure agglomeration,
mechanical agitation, or chemical agglomeration (i.e., by adding a
chemical to the anionic copolymer dispersion and the slurry). These
methods are described in detail in D.C. Blackley, "Polymer Latices:
Science and Technology, Chapter 10.4, Agglomeration and
Concentration of Synthetic Latices," Chapman & Hall, London,
1997 and D.C. Blackley, "High Polymer Latices, Chapter 3,
Agglomeration and Concentration of Synthetic Latices," Maclaren,
Palmerton, 1966. As used herein, the term "agglomeration" refers to
processes for agglomerating particles including partially
agglomerating particles to produce a latex having a greater average
particle size and generally a broader particle size distribution.
The term "co-agglomeration" refers to agglomeration processes such
as those described above for agglomerating the polymer particles in
the anionic dispersion and the inert particles. The
co-agglomeration method can produce a latex with a high total solid
content and a sufficiently low viscosity for use.
[0043] The polymer dispersion used in the co-agglomeration process
is in the anionic form. The method of producing the co-agglomerated
dispersion described herein can further include the step of adding
a cationic surfactant to the co-agglomerated dispersion to make the
polymer dispersion cationic. Cationic surfactants suitable for the
methods described herein include, for example, REDICOTE.RTM. E-5
(Akzo Nobel, Chicago, Ill.), REDICOTE.RTM. E-11 (Akzo Nobel,
Chicago, Ill.), REDICOTE.RTM. E-53 (Akzo Nobel, Chicago, Ill.),
REDICOTE.RTM. E-606 (Akzo Nobel, Chicago, Ill.), REDICOTE.RTM.
E-5127 (Akzo Nobel, Chicago, Ill.), ADOGEN.RTM. 477HG (Chemtura
Corp., Greenwich, Conn.), INDULIN.RTM. W-1 (MeadWestvaco,
Charleston, S.C.), INDULIN.RTM. W-5 (MeadWestvaco, Charleston,
S.C.), INDULIN.RTM. SBT (MeadWestvaco, Charleston, S.C.), and
INDULIN.RTM. MQK (MeadWestvaco, Charleston, S.C.).
[0044] The co-agglomerated particles result in a polymer dispersion
of larger particles with a broader particle size distribution. The
co-agglomerated particles as described herein have a particle size
of 100 nm to 5 .mu.m. For example, the particle size can range from
100 nm to 2 .mu.m or from 200 nm to 1 .mu.m.
[0045] The method of forming the co-agglomerated dispersion can
include the step of removing water from the co-agglomerated
dispersion to increase the solids content. For example, the
co-agglomerated dispersion can be concentrated to produce a solids
content of greater than 50% or greater than 60%. For example, the
method of forming the co-agglomerated dispersion can include the
step of removing water from the co-agglomerated dispersion to
produce a solids content of greater than 50% to 75%, 55% to 72.5%,
or 60% to 70%. The co-agglomerated dispersion, even once
concentrated, can have a viscosity that allows it to readily flow
(i.e. it does not gel). For example, an aqueous dispersion having a
solids content greater than 60% can have a viscosity of less than 1
Pas at 20.degree. C.
[0046] In some embodiments, an inorganic material, e.g., the
inorganic material co-agglomerated with the polymer to form the
co-agglomerated particles or another co-inorganic material, can be
added to the co-agglomerated dispersion. If water is removed from
the dispersion, the inorganic material can be added before or after
the water is removed. The amount of inorganic material added to the
co-agglomerated dispersion is generally less than the amount used
to form the co-agglomerated particles, e.g., less than 20%, less
than 10%, or less than 5% per weight, based on the dry weight of
the polymer. In some embodiments, however, the inorganic material
is only added prior to co-agglomeration of the polymer and the
inorganic material, i.e., none of the inorganic material is
post-added (added after co-agglomeration).
[0047] An aqueous dispersion including the co-agglomerated
particles formed of at least one polymer and at least one inert
material is also described herein. The co-agglomerated particles
have a particle size of 100 nm to 5 .mu.m. The polymer can be
derived from one or more monomers including at least one conjugated
diene monomer such as those described above. The inert particles
can include the particles discussed above in the amount
described.
[0048] The aqueous dispersion including the co-agglomerated
particles can have a surface tension of less than 45 mN/m as
measured using a du Nouy tensiometer according to the method
described in ASTM D 1417-03a, which is incorporated herein by
reference in its entirety. For example, the aqueous dispersion can
have a surface tension of 45 mN/m or less, 40 mN/m or less, or 35
mN/m or less. The aqueous dispersion typically includes free
surfactant (i.e. surfactant that is not interacting with the
co-agglomerated particles because of the reduction in particle
surface area as a result of the co-agglomeration of the polymer
particles and the inert particles).
[0049] The aqueous dispersion can optionally include a cationic
surfactant to make the aqueous dispersion cationic such as those
described above. The solids content of the aqueous inert particles
described herein can be greater than 50% as described above.
[0050] The inert particles can be used in the co-agglomerated
dispersions described herein without pre-treating the inert
particles with chemical modifiers or using layering methods (e.g.,
in situ polymerization, solution intercalation, melt intercalation,
or coagulation). Further, the co-agglomerated dispersions described
herein can be maintained as stable aqueous polymer dispersions and
are thus suitable for a variety of applications. For example, the
co-agglomerated dispersions can be useful in the preparation of
several products, including foamed polymers, latex-based adhesives,
asphalt emulsions including those used as waterproofing membranes,
polymer films, sound absorbing compounds and textile (e.g. carpet)
backing. The products prepared according to the methods described
herein have increased tensile strength, elongation, and heat
resistance as compared to polymer products prepared without
co-agglomerated particles (i.e., exclusion of inert materials or
particle addition of inert materials or particles to the final
dispersion without co-agglomerating). The products prepared with
the co-agglomerated particles described herein achieve
significantly improved elongation without reducing the tensile
strength. Generally, a polymer of lower tensile strength has a high
elongation, but a stronger polymer has a limited elongation. The
polymeric products including the co-agglomerated particles as
described herein maintain the same or slightly higher tensile
strength with significantly improved elongation as compared to
polymeric products prepared without co-agglomeration of the
particles.
[0051] Further, the inclusion of co-agglomerated particles produces
a product that is less susceptible to the degradation of properties
upon prolonged exposure to heat (i.e. heat aging). Heat aging can
result in increased brittleness of the powder formation or can
result in discoloration of the product as evidenced through a
darkening of color. However, the products prepared as described
herein are less affected by this process as evidenced in the
maintenance of color, tensile strength, and elongation. In some
examples, the tensile strength and elongation of the foams
described herein do not change by more than 10% after the product
has been heated at 140.degree. C. for 3 hours.
[0052] The polymer products prepared according to this process have
a better distribution of the inert material throughout the product
compared to polymer products made by previous methods, particularly
compared to polymer products prepared by post-adding an inorganic
material to an agglomerated polymer dispersion. In particular,
because the inert particles are co-agglomerated with the polymer
particles, the inert particles are more uniformly distributed
throughout the polymer product and are substantially uniformly
distributed throughout the polymer product. In prior art methods
where the polymer dispersion is agglomerated and the inert
particles are later added, the inert particles tend to form around
the surface of the agglomerated polymer particles as opposed to
being uniformly distributed throughout the polymer product.
Although not wishing to be bound by a particular theory, the
substantially uniform distribution of the inert material also
appears to result in a parallel orientation of the inert particles,
particularly the inert particles in the form of platelets. This is
evidenced by a uniform blue color when viewing a dried latex film
including the co-agglomerated polymer under a cross-polarized
optical microscope.
[0053] Foamed polymers, including an expanded foam comprising
co-agglomerated particles formed of at least one polymer and at
least one inert material, prepared according to the methods
described herein display the improved mechanical properties
described above. In particular, when a sufficient amount of the
inert material is co-agglomerated with the dispersion, e.g., 10% by
weight or more, 15% by weight or more, 20% by weight or more, 25%
by weight or more, 30% by weight or more, 35% by weight or more, or
40% by weight or more, the foamed polymer can have improved
mechanical properties such as compression resistance. The foamed
polymers can be produced by co-agglomerating an anionic polymer
dispersion to form a co-agglomerated dispersion comprising the
anionic polymer and particles. The resultant dispersion can be used
alone or with one or more additional latex dispersions. In some
embodiments, the foamed polymers are based on styrene
butadiene-based copolymer dispersions and can include
co-agglomerated particles formed from styrene-butadiene copolymer
particles and inert particles.
[0054] The foamed polymer can be produced by first introducing air
or other gases into the latex by mechanical means (e.g. whipping or
beating air into the latex) or by chemical means. The foam can then
be molded or constrained to the shape which is desired for the
final product. The foam can then be solidified or set by
evaporating water from the foam or by gelling the foam. The foam
can then be vulcanized by crosslinking the co-agglomerated
particles.
[0055] The method of producing the foamed polymer can include the
step of adding one or more foaming agents including foam promoters
and foam stabilizers to the co-agglomerated dispersion. Foam
promoters include, for example, carboxylate soaps (e.g., oleates,
ricinoleates, castor-oil soaps and resonates), sulfates,
sulfonates, ethoxylates (including non-ionogenic ethoxylates), and
succinamates. Foam stabilizers useful for preparing the foamed
polymers described herein include quaternary ammonium
surface-active compounds and betaines, amino compounds and amine
oxides, organic hydroxy compounds (e.g., phenols), and
water-soluble hydrocolloids (e.g., proteinaceous substances).
Gelling agents can also be added including alkali-metal
silicofluorides, zinc oxide. Compositions to aid in the curing
process, such as cure or vulcanizing pastes, can be added to the
co-agglomerated dispersion. Vulcanizing pastes can be made from
sulfur and/or zinc oxide dispersions, accelerators (e.g., diphenyl
guanidine, zinc 2-mercaptobenzothiazole and zinc
diethyldithiocarbamate), antioxidants, and water. Other additives
can also be included including fillers (e.g., starches and resins),
softeners (e.g., mineral oil), flame retardants, thickening agents,
and anti-oxidants to facilitate in the formation of the foam.
[0056] The obtained foamable latex compound can be prepared by any
process known to the person skilled in the art for making foamed
articles. Suitable processes include the Dunlop process, the
Talalay process, the Dow process, the Crown Rubber process, and the
Revertex process. The foamed polymers can be used in automotive
applications (e.g. dashboards, bumpers, and seats), furniture
cushions, bedding (e.g. mattresses and pillows), clothing (e.g.,
garment padding), footwear (e.g., shaped parts of shoes and shoe
inside soles), moldings, rubber sheeting, and the like.
[0057] Also described herein are latex-based adhesives and methods
of their use and preparation. The latex-based adhesives can be used
to bond surfaces including metal, ceramic, plastic, paper, leather,
wood, textile, and glass surfaces. The latex-based adhesives
include co-agglomerated particles formed of at least one polymer
and at least one inert material and can be based on one or more
additional latex dispersions. In some embodiments, the latex-based
adhesives are based on styrene butadiene-based copolymer
dispersions and can include co-agglomerated particles formed from
styrene-butadiene copolymer particles and inert particles. The
mechanical properties of the adhesives described herein, including
tensile strength, elongation, and heat resistance, are improved as
compared to adhesives prepared without the co-agglomerated
particles and thus make them suitable for various applications
including flooring applications.
[0058] The co-agglomerated dispersion comprising co-agglomerated
particles formed of at least one polymer and at least one inert
material as described herein can be applied to a surface, a
substrate to be bonded to the surface can be applied to the
dispersion; and water removed from the dispersion to facilitate
bonding. Water can be removed from the co-agglomerated dispersion
prior to applying it to the surface.
[0059] In some embodiments, the latex based adhesives can be
flooring adhesives and the substrate can be flooring to be bonded
to the underlying surface. For example, the flooring adhesives
described herein can be used for adhering carpet, hardwood floors,
tiles, and other flooring to an underlying surface.
[0060] The method of producing the adhesives can include the step
of adding an additive to the co-agglomerated dispersion. For
example, adhesion modifiers (e.g., tackifiers and cooked or
uncooked starches), plasticizers, crosslinking agents, fillers,
extenders, binders, and thickeners can be added to improve the
adherence of the adhesive as known by a person skilled in the art.
Other additives that are suitable for inclusion in the adhesives
described herein include, for example, antioxidants, surfactants,
anti-foaming agents, anti-freeze agents, freeze-thaw stabilizers,
fungicides, corrosion inhibitors, flame retardants, colorants,
deodorants, and reodorants.
[0061] In some embodiments, a modified asphalt emulsion is produced
by combining an asphalt emulsion with the a co-agglomerated
dispersion of co-agglomerated particles formed of at least one
polymer and at least one inert material. The asphalt emulsion can
be used as a waterproofing membrane and applied as a film to
protect substrates, particularly those used in building materials,
such as cement, concrete, wet concrete, wet cement, gypsum,
plaster, masonry, chipboard, hardboard, drywall, wood, ceramics,
marble, stone, and tile from moisture. The substrates can include
various materials including Portland cement, fillers and other
known components, and can be reinforced using, for example, metal
components. The asphalt emulsion can also be used to produce a
sound absorbing coating such as those used in vehicles.
[0062] The following examples are provided to more fully illustrate
some of the embodiments of the present invention. It should be
appreciated by those of skill in the art that the techniques
disclosed in the examples which follow represent techniques
discovered by the inventors to function well in the practice of the
invention, and thus can be considered to constitute exemplary modes
for its practice. However, those of skill in the art should, in
light of the present disclosure, appreciate that many changes can
be made in the specific embodiments that are disclosed and still
obtain a like or similar result without departing from the spirit
and scope of the invention. Parts and percentages are provided on a
per weight basis except as otherwise indicated.
EXAMPLES
Example 1 and Comparative Examples 1-3
[0063] BUTONAL.RTM. NS103 (BASF Corporation, Florham Park, N.J.) is
a cold polymerized poly(styrene-butadiene) latex of approximately
25% styrene and 75% butadiene and 45-47% solids. The latex has a
viscosity of 100-300 mPas, a surface tension of above 50 mN/m, and
a particle diameter below 100 nm.
[0064] BUTONAL.RTM. NS103 and a sufficient amount of a Kaolin HT
clay slurry commercially available from BASF Corp., Engelhard
Division (70 weight % clay) to provide 5% kaolin clay in the
dispersion (based on the weight of the dry polymer) were frozen at
-20.degree. C. for 24 hours, and thawing of this frozen sample
resulted in production of a co-agglomerated latex (Example 1)
having a broad size distribution ranging from 100 nm to below 5
.mu.m in diameter, and the surface tension and viscosity of the
latex dispersion was 30-35 mN/m and below 20 mPas after the
freeze-agglomeration. The agglomeration of BUTONAL.RTM. NS103 and
the kaolin clay slurry caused significant reduction in the total
surface area of the latex particles in the dispersion, which
resulted in an increase in the surfactant coverage on the latex
particles, thus improving the dispersion stability. The reduction
in the latex surface area also resulted in an increase in the free
surfactant in the water phase of the latex dispersion and thus a
reduction in the surface tension of the latex dispersion.
[0065] Comparative Example 1 was prepared by post-adding an
appropriate amount of a 70 weight % of Kaolin HT slurry (BASF
Corp., Engelhard Division) into BUTONAL.RTM. NS103 to produce a
latex sample containing 5 weight % of kaolin clay.
[0066] A formulation was prepared by pressure agglomerating
BUTONAL.RTM. NS103 without the presence of the kaolin clay slurry
and resulted in a latex having a broad size distribution ranging
from 100 nm to below 5 .mu.m in diameter. The agglomerated latex
had a lower surface tension value of 30-35 mN/m, and the broad size
distribution of this agglomerated latex allows maintaining a
relatively low viscosity of below 2 Pas after removing water and
concentrating to approximately 70% solids. The resultant latex is
Comparative Example 2.
[0067] Comparative Example 3 was prepared by post-adding an
appropriate amount of a 70 weight % of Kaolin HT slurry (BASF
Corp., Engelhard Division) into Comparative Example 2 to produce a
latex sample containing 5 weight % of kaolin clay.
Preparation of Latex Films and Tensile Strength and Elongation
Measurements:
[0068] Latex Films for Formulation Example 1 and Comparative
Examples 1-3 were prepared by drying at room temperature for 3
days, and then cured at 60.degree. C. for an additional day. The
resultant latex films were approximately 200-300 .mu.m thick and
were cut to prepare a rectangular specimen approximately 1.2 cm
wide and 2.5 cm long. The tensile vs. elongation property of the
latex films were measured by Instron (Instron Corp., Norwood,
Mass.) at room temperature. The tensile vs. elongation property of
the latex films were compared in FIGS. 1A and 1B. These results
demonstrated that the post-addition of kaolin clay into the
non-agglomerated latex resulted in improved elongation of the latex
film without improving the maximum tensile strength. In comparison,
the 5% clay freeze-agglomerated BUTONAL.RTM. NS103 showed nearly a
2.times. increase in the maximum tensile strength against pressure
agglomerated latexes (with 0 and 5% clay post added) without losing
the maximum elongation. Even though the mechanical properties of
BUTONAL.RTM. NS103 improved with post-addition of the clay slurry,
this latex has a low solids content and limited dispersion
stability. In contrast, the clay freeze co-agglomerated
BUTONAL.RTM. NS103 can be concentrated to produce a latex of nearly
70% solids due to its broad size distribution, and provide similar
dispersion stability as Comparative Example 2.
Example 2 and Comparative Example 4
[0069] A freeze co-agglomerated dispersion (Example 2) was prepared
in the same manner as in Example 1 except that Kaolin HT clay is
provided to produce 2% kaolin clay in the dispersion. Comparative
Example 4 was prepared solely from the freeze agglomerated
BUTONAL.RTM. NS103 with no clay addition. Latex films including
Example 2 and Comparative Example 4 were prepared as discussed
above. The latex film based on Example 2 and the latex film based
on Comparative Example 4 were prepared by drying at room
temperature for 10 days and the tensile strength and elongation
were measured without curing at 60.degree. C. for 24 hours. The
tensile strength vs. elongation behavior of these latex films was
compared. An approximate 2.times. increase in the maximum tensile
strength without reducing the maximum elongation was shown using
the 2% Kaolin HT co-agglomeration of Example 2 as shown in FIG.
2.
Examples 3-4
[0070] BUTONAL.RTM. NS103 was freeze co-agglomerated using the
process described in Example 1 except in the presence of 5 and 10
weight % of MIRAGLOSS.RTM. 91 (BASF Corp., Engelhard Division)
resulting in Examples 3 and 4, respectively. The latex film was
dried and cured as described in Example 1. Improvement in the
maximum tensile strength as well as the maximum elongation was
observed with these MIRAGLOSS.RTM. 91 co-agglomerated latex films
as shown in FIGS. 3A and 3B. The reproducibility of the tensile
strength vs. elongation measurements of these latex films was also
demonstrated by testing Examples 3 and 4 more than once in these
figures.
[0071] The latex films for Formulation Examples 3 and 4 were
prepared as described above. After curing at 60.degree. C. for 24
hours, these latex films and Comparative Example 4 were heat aged
at 140.degree. C. for 3 hours. The film based on Comparative
Example 4 was very sensitive to the heat aging due to its high
butadiene content, and became dark brown in color as shown in FIG.
4B and was very brittle, thus preventing the tensile strength vs.
elongation measurement. The latex film prepared from Example 3 was
lighter in color than the film based on Comparative Example 4 as
shown in FIG. 4B, but only had limited mechanical strength as
demonstrated in FIG. 4A. The latex film prepared according to
Example 4 showed only limited degree of discoloration after the
heat aging process as shown in FIG. 4B, and maintained the same or
even improved tensile strength vs. elongation behavior than before
the heat aging (FIG. 3B vs. FIG. 4A). The results demonstrated that
the clay co-agglomeration process improved the mechanical strength
of the BUTONAL.RTM. NS103 films and also reduced the heat aging
properties.
Examples 5-6 and Comparative Example 5
[0072] BUTONAL.RTM. NS103 was pressure co-agglomerated with an
elemental sulfur dispersion containing an optimized type and amount
of the vulcanization reaction accelerating agent described in U.S.
Pat. Nos. 6,127,461; 6,300,392; and 6,348,525, which are
incorporated herein by reference in their entirety. The
co-agglomerated latex was further concentrated to 70% solids, and
the resultant latex is Comparative Example 5.
[0073] BUTONAL.RTM. NS103 was freeze co-agglomerated in the
presence of 5 and 10 weight % of MIRAGLOSS.RTM. 91 together with
the elemental sulfur dispersion described above resulting in
Examples 5 and 6, respectively. Latex films based on Example 5,
Example 6 and Comparative Example 5 were prepared using the
procedure described in Example 1 and cured at 100.degree. C. for 3
hours. The tensile strength vs. elongation behavior of these latex
films were compared in FIG. 5. These results demonstrated improved
mechanical properties of the clay co-agglomerated latex films.
Comparative Example 6
[0074] Comparative Example 6 was prepared in the manner described
for Comparative Example 3 except that 10% MIRAGLOSS.RTM. 91 was
post-added into the co-agglomerated dispersion instead of 5% Kaolin
HT and a latex film was prepared as described in Example 1. A film
based on Example 4 was also prepared using the same procedure.
After 24 hours of curing at 60.degree. C., both films were further
cured at 100.degree. C. for 3 hours and the tensile vs. elongation
behavior was tested as shown in FIG. 6. The measured tensile vs.
elongation relationships shown in FIG. 6 demonstrate the improved
mechanical properties of the latex film prepared from the
freeze-agglomerated latex.
Example 7
[0075] Example 7 was prepared according to procedure used for
Examples 3 and 4, except that 5% ground calcium carbonate
(HYDROCARB.RTM. 90, Omya, Inc., Proctor, Vt.) was used instead of
kaolin clay (MIRAGLOSS.RTM. 91). Latex films were prepared based on
Comparative Example 4 and Examples 3, 4, and 7 based on the
procedures described in Example 1. After curing at 60.degree. C.
for 24 hours, the tensile vs. elongation behavior of the latex
films were determined. As shown in FIG. 7, Example 7 nearly doubled
the maximum elongation at break without affecting the maximum
strength. The latex films prepared from Examples 3-4 demonstrated
improvement in both the maximum tensile strength as well as
elongation. Further improvement on the mechanical strength was
demonstrated in Example 4.
Examples 8-10 and Comparative Example 7
[0076] Examples 8 and 9 were prepared according to the procedure
used for Examples 3 and 4, except in the presence of 20 and 40
weight % of MIRAGLOSS.RTM. 91, respectively. Example 10 was
prepared according to a similar procedure as Example 8, except that
20 weight % of MIRAGLOSS.RTM. 91 was post-added to the latex sample
in addition to the 20 weight % of co-agglomerated clay. Comparative
Example 7 was prepared by post-adding an appropriate amount of a 70
weight % of Kaolin HT slurry into BUTONAL.RTM. NS103 to produce a
latex sample containing 40 weight % of kaolin clay. Latex films
were prepared for Examples 8-10 and Comparative Examples 2 and 7
based on the procedures described in Example 1. After curing at
60.degree. C. for 24 hours, the tensile vs. elongation behavior of
the latex films were determined. The tensile strength vs.
elongation behavior of these latex films were compared in FIG. 8.
These results demonstrated improved mechanical properties of the
clay co-agglomerated latex films as compared to the post-added clay
latex films.
[0077] The latex films prepared from Example 9, Example 10, and
Comparative Example 7 were further cured at 130.degree. C. for 30
minutes and the tensile vs. elongation behavior was tested as shown
in FIG. 9. The measured tensile vs. elongation relationships shown
in FIG. 9 demonstrate the improved mechanical properties of the
latex film prepared from the co-agglomerated latex samples.
Example 11 and Comparative Examples 8 and 9
[0078] The latex sample as described in Comparative Example 2 was
compounded according to the procedure as follows to prepare the
adhesive samples. The pH of Comparative Example 2 was raised to
12.5-13.0 using 10% KOH. The mixture was then warmed to 35.degree.
C. and agitated. A molten resin-oil mix including 179 g Tufflo 1200
(Citgo; Houston, Tex.), 146 g Neville LX-1200 (Neville Chemical
Co.; Pittsburgh, Pa.), and 33 g Melhi resin (Eastman Chemical
Company; Kingsport, Tenn.), was slowly added to the latex mixture.
Tufflo 1200 is a plasticizer composed of naphthenic process oils.
LX 1200 is a petroleum hydrocarbon resin useful as an extender.
Melhi is a thermoplastic acidic resin binder that serves as a
binder or tackifier. The pH was adjusted to 11.0-12.0 with 10% KOH.
After agitating for 2 minutes, the mixture was allowed to cool.
After cooling, a light-brown homogeneous adhesive latex mixture
resulted with 81.3% solids content and a viscosity of 28 Pas
(Comparative Example 8).
[0079] Comparative Example 9 was prepared by pre-adding an
appropriate amount of MIRAGLOSS.RTM. 91 into Comparative Example 2
to produce a latex sample containing 10 wt % of clay. The resulting
adhesive latex mixture was a light-brown homogeneous adhesive latex
mixture with 79.2% solids content and a viscosity of 20 Pas.
[0080] BUTONAL.RTM. NS103 was pressure co-agglomerated with 10 wt %
MIRAGLOSS.RTM. 91 clay and concentrated to 70% solids by removing
water (Example 11). An adhesive latex mixture including Example 11
was prepared according to the procedure described for Comparative
Example 8. The resulting adhesive latex mixture was a light-brown
homogeneous adhesive latex mixture with 79.0% solids content and a
viscosity of 27 Pas.
[0081] Each of the adhesive latex mixtures were applied
individually to plywood, and a piece of hardwood was pressed down
onto the adhesive latex mixture to form the test assemblies. Half
of the test assemblies were allowed to dry for 14 days at room
temperature, while the other half were allowed to dry for 14 days
at 50.degree. C. The lap shear of the adhesive latex mixtures for
Example 11 and Comparative Examples 8 and 9 were measured by lift
tests (ASTM D 907-96a). The lift tests were conducted by forcing
the hardwood pieces up to a 90.degree. angle using an Instron
instrument (Instron Corp., Norwood, Mass.) at room temperature. The
lap shear property of the adhesive latex mixtures were compared in
FIGS. 10 and 11. These results demonstrated that co-agglomerated
adhesive latex (Example 11) has superior adhesive properties at
elevated temperatures over adhesives without clay and adhesives
with clay added but that are not co-agglomerated.
[0082] The composites and methods of the appended claims are not
limited in scope by the specific composites and methods described
herein, which are intended as illustrations of a few aspects of the
claims and any composites and methods that are functionally
equivalent are intended to fall within the scope of the claims.
Various modifications of the composites and methods in addition to
those shown and described herein are intended to fall within the
scope of the appended claims. Further, while only certain
representative composite materials and method steps disclosed
herein are specifically described, other combinations of the
composite materials and method steps also are intended to fall
within the scope of the appended claims, even if not specifically
recited. Thus, a combination of steps, elements, components, or
constituents may be explicitly mentioned herein; however, other
combinations of steps, elements, components, and constituents are
included, even though not explicitly stated. The term comprising
and variations thereof as used herein is used synonymously with the
term including and variations thereof and are open, non-limiting
terms. Although the terms comprising and including have been used
herein to describe various embodiments, the terms consisting
essentially of and consisting of can be used in place of comprising
and including to provide for more specific embodiments of the
invention and are also disclosed.
* * * * *