Note: Descriptions are shown in the official language in which they were submitted.
~ ~9~/~162 . 2 1 1 6 4 5 8 PCT~US92/0807~
~, '
IMPROVED ADHESIVES AND SEALANTS
This invention relates to adhesives and sealants
and, more paxticularly, to a process for improving the
adhesion of adhesives and sealants as well as an adhesive
and sealant composition which displays improved adhesion.
The invention has~been found to be especially useful
for expanded adhesives and sealants which traditionally
employed a blowing agent.
Blowing agents, sometimes referred to as foaming
agents, are substances that produce a cellular structure
in a fluidized plastic or rubber composition. Conventional
blowil~g agents include fluorocarbons, nitrogen gas,
hydrazine derivatives, trihydrazide triazine, 5-phenyl
tetrazole, p-toluene sulfonyl semicarbazide, modified
azodicarbonamide, and azodicarbonamide. Chemical blowing
- 15 agents are a class of blowing agents which are solids
or li~uids at room temperature and ~hich, upon heating
release a gas. A well-known class of chemical blowing
agents is sold under the trademark CELOGEN by Uniroyal, Inc.
91Owing agents are used in making a variety of
consumer products and automotive sealants. Further,
blowing agents are used with adhesive plastic materials
in a hot melt adhesive. Blowing agents are also used
in foodstuff wrapping which is applied to the exterior
of animal parts after they have been butchered and prior
to wholesale. Such product is referred to by some as
"bone wrap".
Typically, chemical blowing aaents are used by
mixing the chemical blowing agent with a solid plastic
material and then heating the admixture while maintaining
the mix under pressure. Heating fluidizes the plastic
material and causes the blowing agents to release a
gas. The gas forms bubbles or cells in the fluid plastic
material.
~B ~
WO93/~162 ' 2 1 1 6 4 5 8 PCT/US92/0807~
Chemical~lowing agents have the advantage over
gaseous blowing agents in that they can be added to
the solid plastic material prior to heating. Gaseous
blowing agents such as nitrogen and some fluorocarbons
must be injected into the fluidized plastic material.
With hot melt adhesives and sealants, a gas is mixed
with the adhesive composition prior to the end of the
nozzle.
The use of f luorocarbons as blowing agents has
come under close scrutiny due to its alleged effect
~ on the earth's ozone layer. Other conventional blowing
agents present problems with handling, toxicity, and
flammability. Handling problems include storage stability,
dust, and explosion hazards.
15It has now been discovered that the use of the
cyclodextrin in sealants and adhesive compositions improves
the adhesive quali~y of the sealant o~ adhesive composition.
It has also been discovered that a complex of cyclodextrin
and blowing agent functions as~a blowing agent in fluidized
adhesive and~or sealant plastic materials as well as
improving the adhesive property of the adhesive or sealant.
The cyclodextrin has been found to stabilize the blowing
agent. It has also been discovered that certain chemical
compounds can be used as blowing agents which were heretofore
never used as blo~ing agents.
The process according to the present invention
comprises admixing a cyclodextrin with an adhesive or
sealant plastic material and then applying the admixture
to a surface. In the case of an expandable sealant
or adhesive, the process comprises the steps of forming
an admlxture comprising an adhesive and/or sealant plastic
material and a co~plex of a blowing agent and a cyclodextrin
and heating the admixture so as to fluidize the plastic
material and cause the complex to release a gas. The
gas forms cells in the fluidized plastic material.
P3 .
W093/~162 - ~ . 2 1 1 6 4 5 8 PCT/US92tO807~
--3--
A step of forming a complex between the cyclodextrin
and the blowing agent lS accomplished prior to the step
of mixing the complex with the plastic material.
The step of heating the admixture is accomplished
either by applying heat to the admixture as is typically
the case in conventional extrusion or blow molding processes,
or through an exothermic reaction, such as is normaIly
the case with a polyurethane.
An adhesive and/or sealant composition made in
accordance with the present invention comprises an adhesive
and/or sealant plastic material and a complex of a blowing
agent and a cyclodextrin. As noted above, it has been
found that the adhesive nature of the sealant or adhesive
composition is improved by the presence of the cyclodextrin
in the composition. Thus, the cyclodextrin performs
not only as a host for the blowing agent but also as
an agent or means for improving the stickiness or tackiness
of the sealant or adhesive.
The amount of cyclodextrin added to the adhesive
and/or sealant plastic material is an'effective amount
to improve the adhesion of th ~ ive and/or sealant.
Preferably, the amount of cyclodext ~n added to the
adhesive and/or sealant plas~ic materlal to improve
- its adhesion is about 1 to a~out 30 parts by weight
based on 100 parts of adhesive and/or sealant plastic
material (php). More preferably, about 1 to about 15
php of cyclodextrin is added to the adhesive and/or
sealant plastic material to improve its adhesion. Most
preferred is to add about 1 to about 10 php of cyclodextrin
to the adhesive and/or sealant plastic material to improve
the adhesion. The amounts listed herein are also the
amount of complex of cyclodextrin and blowing agent
which is added to the adhesive and/or sealant plastic
material in accordance with the present invention.
- .h .
W093/~162 , 2 1 1 6 4 5 8 PCT/US92/0807~
In order to form the admixture between the cyclodextrin
and the adhesive and/or sealant plastic material or
the complex of cyclodextrin and blowing agent and the
adhesive and/or sealant plastic material, any conventional
mixing procedure normally employed with the adhesive
and/or sealant materials may be used.
Cyclodextrins, also called "Schardingers dextrins",
cycloamyloses, cyclomaltoses and cycloglucans, are oligomers-
of anhydroglucose, bonded together by alpha 1,4 bonds
to form a ringed compound. A six membered ring is called
alpha cyclodextrin; seven, beta cyclodextrin, and eight,
gamma cyclodextrin. These six, seven and~eight membered
rings are also referred to as cyclomaltohexaose,
cyclomaltoheptaose and cyclomaltoctaose, respectively.
Conventionally, cyclodextrins are obtained by treating
a starch slurry with enzyme or acid to produce a gelatinized
~ and liquefied slurry having a DE between 1 and 5. The
gelatini~ed and liquefied starch slurry is then treated
with cyclodextrin glycosyltransferase ~CGT), at the
appropriate pH, temperature and time for the selected
CGT. The enzyme, CGT, is obtained from microorganisms
such as Bacillus macerans, B. magaterium, B. circulans,
B. stearothermophilus, and Bacillus sp. (alkalophilic~
as well as others. The resulting digest from treatment
of a gelatinized and liquefied starch slurry with CGT
is- then subjected to a separation and purification process
to obtain cyclodextrlns.
One of the commercially important aspects of
cyclodextrins is their ability to act as a clathrate
or host to other commercial compounds. Physically a
cyclodextrin is donut-shaped. The consequence of this
is that cyclodextrins are able to act as a clathrate
with substances that have outer geometric dimensions
corresponding to the diameter of the cyclodextrin cavity.
. . .
~W~93~K1b2 2116 4 S 8 PCTlUS~/~75
~ -5~
..
Often the exterior is modified by adding a side chain
such as hydroxy-propyl cyclodextrin onto the dohut-shaped ''
exterior of the cyclodextrin. The term "cyclodextrin"
as used in the specification and claims means not only
cyclodextrin per se but also modif'ied cyclodextrins
and brAncheA cyclodextrins'.
The term "complex" or the expression "complex of
cyclodextrin and blowing agent" as used in the specification
and claims means not only a composition of cyclodextrin
and blowing agent where the'cyclodextrin acts as a host
to the blowing agent but also where the blowing agent
is closely associated with the exterior of the cyclodextrin
by weak hon~i~g forces.
A method for formation of a complex between a
cyclodextrin and a~blowing agent involves dissolving
the cyclodextrin in watér'with a blowing agent and
collecting the~precipitate that forms.
~ ~ Another method is by charging a ball mill with '
a cyclodextrin and a blowing agent and milling the charge
' 20 in the ball'mill for a period of time. After milling,
a complex will form between the cyclodextrin and the
biowing agent. Other known methods for forming a complex
between a cyclodextrin and a guest molecule include
kneading, freeze-drying and co-grinding. Good results
have been obtained by co-grinding using a mortar and pestle.
Suitably, the cyclodextrins used in the present
invention are alpha, beta or~gamma cyclodextrin. Beta
cyclodextrin is preferred because of its commercial
availability. A complex made from a combination of
all three cyclodextrins provides different rates of
reiease of~ the blowing agent. 'This is thought to be
due in part to the different'bond strengths between
the blowing agent and the different cyclodextrins.
Suitable blowing agents include liquids such as
PCI~/US
2116458 -6-
water, propylene-glycol, dipropylene glycol, tripropylene
glycol, cyclohexyl amine, dicyclohexyl amine and ethylene
glycol and eolids such as benzoyl peroxide and other
peroxides which are difficult to process. It is both
surprising and unexp~cted that water, propylene glycol,
dipropylene glycol, tripropylene qlycol, and ethylene
glycol are useful as blowing agents. Heretofore, water,
- ~
propylene glycol, dipropylene glycol, tripropylene glycol,
aad ethylene glycol were not used as blowing agents
due to their poor dispersion in plastic materials.
Soli~s such as benzoyl peroxide are difficult to process
because of low decompos~ition temperature. Both water
and propylene glycol are considered safe and non-toxic
to humans. Many conventional blowing a~gents are toxic
to humans. The use of such non-toxic blowing agents
in $he workplace brings a degree of safety to the workplace
heretofore unknown. By using a combination of two or
more blowing agents such as water and propylene glycol
or by using different cyclodextrins with the same blowing
.
agents, the application temperature of the blowing agent
is var$ed.
Additionally, conventional chemical blowing agents
such as hydrazine derivatives, trihydrazide triazine,
5-phenyl tetrazole, p-toluene sulfonyl semicarbazide,
modified azodi~arbonamide, and azodicarbonamide which
~:
f~orm a complex with cyclodextrin may be used as a blowing
agent in accor~ance with the present invention.
Conventional biowing agents complexed with cyclodextrin
reduce dusting and stabilize the composition.
The amount of blowing agent that is complexed with
the cyclodextrin is about 1 to about 30 parts by weight
based on 100 parts by weight cyclodextrin (phc). More
preferably about 3 to 15 phc is complexed.~ Most preferred
i~ to complex ~etween about 5 to about 7 phc of the
blowing agent with the cyclodextrin.
- W093/~162 . F 2 1 1 6 4 5 8pCT/us92/o8~7~
-7-
In forming the complex between the cyclodextrin
and blowing agent, an excess amount of blowing agent
is used to form the complex.
A suitable source of the complex of cyclodextrin
and water has been found to be the cyclodextrin as taken
from a commercial operation for making cyclodextrin.
The cyclodextrin obtained from a commercial process
generally has about 10 to about 12 phc water. Using
this cyclodextrin in an adhesive composition has been
found to provide adequate gas upon heating such that
the commercially obtained cyclodextrin, which is complexed
with about 10 to about 12 phc water, works as a blowing
agent.
Generally, it had been found that the smaller theparticle
size of the complex, the more uniform-the bubbles were
in size. Good results have been obtained with a complex
of cyclodextrin and a blowing agent having a particle
size capable of passing through 200 mesh.
Suitable plastic materials include polymers such
as polystyrene, polyvinyl chloride, polyethylene,
polyurethane, polyphenols, polypropylene, polyisoprene
(rubber), polybutadiene as well as copolymers such as
acrylonitrile-butadiene-styrene, styrene-isoprene,
ethylene-butylene, styrene-butadiene rubber and ethylene
vinyl acetate. Specific examples of adhesive plastic
materials include ethylene ~inyl acetate (EVA) r
acrylanitrile-butadiene- styrene and styrene-isoprene.
Good results have been obtained using the complex of
the present invention with EVA.
A typical adhesive made in accordance with the
present invention comprises:
Parts by Weight
EVA 25-50
Modified Resins 25-60
. ~ .
IF21 16458
~ 093/~162 PCT/US92~08075
_~_
Waxes - ~ 30
Total Adhesive Plastic Material 100
Antioxidant 0.05-0.5 php
Filler 0-100 php
5 Blowing Agent-Cyclodextrin Complex1-10 php
A bookbinding adhesive made in accordance with
the present invention comprises:
Parts by Weight
EVA 35-45
10 Modified Resin 20-30
Plasticizer 20-30
Wax 10-20
Total Plastic Adhesive Material 100
Antioxidant 0.05-0.25 php
15 Blowing Agent-Cyclodextrin Complex1-10 php
Mildewcide (optional) 1-10 php
Preferably, the blowing agent-cyclodextrin complex
is a water-cyclodextrin complex and has between about
8 and about 15 phc water. More preferably the amount
of complex used in the bookbinding adhesive is between
ahout-3 and about 7 phc and has a water content of about
10 to about 15 phc.
Use of a microbiocide or fungicide complexed with
a cyclodextrin, if incorporated with the adhesive, helps
prevent degradation. Water will act as the blowing
agent and will aid in the release of the microbiocide or
fungicide.
The bookbinding adhesive is made by mix;nq all
the components together in a conventional manner.
Such adhesives have an application temperature
around 120 to about 205~C.
The use of a complex of water and cyclodextrin
has been found to have several advantages over the prior
art of using liquid nitrogen. Present machinery for
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2116458
~WD93/061~2 PCT/USg2i~W75
~ ~ 9--
application of hot melt for bookbinding requires specialized
machinery allowing incorporation of li~uid nitrogen.
With the cyclodextrin-water complex of the present invention
a much wider range of equipment can be used. ~Additionally,
thè open time has increàsed, there is more surface contact
~; and less~adhesive is used to cover the sàme area.
A carton and case sealing adhesive is made in
accordance with the present invention comprising:
Parts by Weight
10 EVA
- Modified Resin ~ 40
- Wax ~ ~ 20
Total Plastlc Adhesive Material 100
Antioxidant 0.01 php
15 Blowing Agent-Cyclodextrin Complex 1-10 php
Preferably, the blowing agent-cyclodextrin complex
is a propylene glycol-cyclodextrin complex and has between
about 8 and about 15 phc of propylene-glycol. Preferably
about 3 to about 7 php of the complex is used having
a propylene glycol content of about 10 to about 13 phc.
The carton and case sealing adhesive is made by
mixing all the components together in a conventional
manner.
Such carton and case sealing adhesive has an application
temperature between about 175 to about 205~C.
A carpet backing adhesive made in accordance with
the present invention comprises:
Parts by Weight
EVA 25-50
30 Modified Resin 25-60
Waxes 0-30
. ~ . .
Total Plastic Adhesive Material 100-
Antioxidant .05-0.5 php
Filler 0-100 php
35 Blowing Agent-Cyclodextrin Complex 1-10 php
- ~ .
t '; l
W~ g3/06162 PCI~/USg2/08075
- 2116 158 -lO- iJ
The blowing agent-cyclodextrin complex used in
this carpet~backing adhesive is a complex of cyclodextrin
with about 8 to about 15 phc of either water, propylene
glycol or a combination of water and propylene glycol
S or a combina~tion of water, propylene gylcol and hydrazine
derivatives.
Additionally, such a carpèt backing adhesive preferably
contains a complex of cyclodextrin and mildewcide in
an amount up to about 1 php. Suitable mildewcides include
. diiodomethyl-p-tolysulfone, phenols and butylhydroxytoluene;
diidomethyl-p-tolysulfone is preferred, the release
of which would be triggered by water released by the
cyclodextrin.
The carpet backing adhesive is made by mixing all
the components together in a.conventional manner.
~ The application temperature of this carpet backing
adhesive is between about 300 to 350~F.
It has been found that the presence of the cyclodextrin
in these various adhesives and sealants also increases
the adhesive nature of the sealant or adhesive composition.
~ A small amsunt of enzyme known as amylase added
to the exp~n~h}e plastic composition of the present
invention will~, upon heating, act as a catalyst to speed
the release.o~f the blowing-agen~t from;the cyclodextrin. - -
For the amylasq~to..~act as~a;~atalyst~, some w:ater must :~
be present in the plastic composition. It is thought
that the amylase will use the water to destroy the
cyclodextrin thereby hastening the release of the blowing
agent.
It will be understood that other compounds can
be added to the plastic material containing the blowing
agent of the present invention, to include mildewcides,
fungicides, and fragrances.
,
~,~9~/06162 r 2 1 ~ 6 4 5 8 PCT/US92/0807~
--11--
These and other ~aspects of the present invention
may be more fully understood by reference to the following
examples:
EXAMPLE 1
This example illustrates a hot melt adhesive in
accordance with the present invention and specifically,
a bookbinding adhesive.
Bookbinding Material Parts by Weight
EVA-507 * 45
10 Staybeli*te Resin 25
- P~ntalyn H 20
Microcrystalline Wax 10
Total Plastic Bookbinding Material 100
To the adhesive plastic materials, 0.1 php of an
antioxidant and 10 php of a water-beta cyclodextrin
complex were added. The complex comprised 7.5 grams
of beta cyclodextrin and 2.5 grams of water. The water
was complexed with the cyclodextrin by mixing an excess
of water with the cyclodextrin. After mixing the adhesive
plastic materials with the antioxidant and the water-beta
cyclodextrin complex, this admixture was heated to lQ0~C
at which point the water went from a liquid phase into
a gas phase thereby causing an expansion of the adhesive.
The percent of expansion by volume of the adhesive was
about 100~.'
EVA-507 was a commercial grade of a copolymer of
ethylene-vinyl acetate obtained from Union Carbide Corp.
Staybelite resin was a hydrogenated resin and plasticizer
consisting of diethylene glycol esters of hydrogenated
resins obtained from Hercules Powder Co. Pentalyn H
was a synthetic resin obtained from Hercules Powder
Co. Microcxystalline wax was a commercially available
wax obtained from Petrolite Corp. of Tulsa, Oklahoma.
The antioxidant was Irganox 1010 obtained from Ciba-Geigy
*Trade-mark
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r21 1645 8
W093/~162 PCT/US92/080
-12-
Corp. The beta cyclodextrin was a commercial grade
beta cyclodextrin obtained from American Maize-Products
Company of Hammond, Indiana. The water was regular
tap water.
It is surprising and unexpected that a complex
of cyclo~extrin and water worked in this formulation
because water, by itself, did not work as a blowing
agent in the bookbinding adhesive.
EXAMPLE 2
Thi~ example illustrates making a carton and case
adhesive in accordance with the present invention.
The following adhesive composition was made:
Material Parts by Weight
EVA-305 40
CKM-2400 15
Piccolyte A-115 12.5
Super STATAC 12.5
Polywax 1000 10
Castor wax 10
Total Plastic Adhesive Material 100
To the adhesive plastic materials, 0.1 php of an
antioxidant and 10 php of a complex of propylene glycol-beta
cyclodextrin were mixed. The complex contained 1 mole
of beta cyclodextrin and 2 moles of propylene glycol.
The complex of propylene glycol and beta cyclodextrin
was made by mixing an excess of propylene glycol with
the beta cyclodextrin.
The admixture of adhesive materials, antioxidant
and propylene glycol-beta cyclodextrin complex was heated.
Propylene glycol went from a liquid state to a gaseous
state thereby causing the expansion of the adhesive
composition. The adhesive composition expanded in volume
due to the blowing agent, propylene glycol, by about
100~ .
*Trade-mark
2116458
~W~9~06162 PCT~US92/~7
~ 13
EVA-305 was a commercial grade of a copolymer of
~ ethylene-vinyl acetate obtained from Union Carbide.
- CRM-2400 was obtained from Union Carbide. Piccolyte
A-115 was a thermoplastic terpene resin obtained from
Hercules. Super~STATAC was obtained from Reichold Chemical
Inc. Polywax 1000 was obtained from Bareco and Castor
wax was obt~ine~ from-Universal Preservachems. The
antioxidant was Irganox 1010. The beta cyclodextrin
was a commercial grade beta cyclodextrin obtained from
American Maize-Products Company of Hammond, Indiana.
The propylene gly~ol was a commercial grade obtained
from Dow Chemical.
It is both surprising and unexpected that a complex
of propylene glycol and cyclodextrin worked in this
formulation since propylene glycol, by itself, did not
work as a blowing agent.
EXAMPLE 3
This example illustrates making a carpet backing
adhesive in accordance with the~present invention.
The following adhesive composition was made:
Material Parts by Weight
: '~0
Modifying resins -40
Waxes ~ 10
25 Total Plastic Adhesive Material 100
Mildewicide (optional~ 1-10 php
To the adhesive pl-astic materials, 0.1 php of an
antioxidant, about 20 php of a filler, and 5 php of
a complex of water~and beta cyclodextrin are added along
with 5 parts of a complex of prôpylene glycol-beta
cyclodextrin. The complexes of blowing agent and
cyclodextrin are made in accordance with Examples 1
~-and 2 above. The complexes of blowing agent and
c-yclodextrin are both mixed with the adhesive composition
simultaneously in a manner according to Examples 1 and
2 above.
'~ '".,i~q:
~ a1 1645 B
3/06162 - PCT/U592108075
-14-
Upon heating the admixture of adhesive composition
and both hlowing agents to about 195~C the adhesive
admixture expands.
The EVA is a commercial grade of a copolymer of
ethylene-vinyl acetate. The modified resins are commercia]
grades of wood rosin. The waxes are commercial grades
of waxes used conventionally in carpet backing adhesives.
The antioxidant is Irgonox lOlO and the fillers are
conventional calcium carbonate.
EXAMPLE 4
This example illustrates making a pressure sensitive
adhesive in accordance with the present invention.
The following adhesive composition was made:
Material Parts by Weight
EVA 50l 15
EVA 605 30
Staybelite Ester lO 37
Abitol l8
Total Plastic AdhesivelO0
To the adhesive materials, ~.l php of an antioxidant,
Irganox lOlO, 5 php of a complex of water and beta
cyclodextrin and 5 php of cyclohexylamine and beta
cyclodextrin were added. The water and beta cyclodextrin
complex had 12.8 phc water. The complex of beta cyclodextrin
and cyclohexylamine, volatile corrosion inhibitor, had
8 phc cyclohexylamine complexed with cyclodextrin.
Making the complex and mixing of the adhesive composition
was done in accordance with Example l.
The released moisture provided a "trigger" mechanism
whereby the complexed cyclohexylamine was partially
released so as to be in equilibrium with the released
moisture from the water-cyclodextrin complex. Such
a mechanism provided corrosion protection to metallic
surfaces. The complex of cyclodextrin and cyclohexylamine
stabilizes the cyclohexylamine durinq the heating process.
*Trade-mark
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~ g 1 16 45 8
W093/06lC2 ~ PCT/US92/0807
-15-
Uncomplexed cyclohexylamine is not stable during the
heating of the adhesive. The EVA 501 and 605 were a
commercial grade of a copolymer of ethylene-vinyl acetate
obtained from Union Carbide. The Staybelite Ester 10
and the Abitol were obtained from Hercules. The application
temperature of the adhesive was about 300~~ to 325~F.
EXAMPLE 5
This example illustrates making an expandable,
curable sealant in accordance with the present invention.
A. - Hot melt base
Ingredient Parts
~raton FC 1901 x
(available from Shell) 100
Regalrez. 1018
(available from Hercules) 270
Endex 155
(available from Hercules) 50
Irganox 1010
(available from Ci~a Geigy)
B. - Plasticizer
over-based Calcium Sulfonate
(a~ailable from Witco) 10
Beta cyclodextrin:dicyclohexylamine
complex (2:1 molar ratio) 2
Aluminum paste (50:50 aluminum in
Sunpar 2280 available from Sun Oil)
Beta cyclodextrin (10-13% H2O) 2
Equal amounts of the hot melt base and plasticizer
were mixed and allowed to cool and then placed on a
cold rolled steel sh~et or galvanized cold rolled steel
sheet. The sheets were placed in an oven and heated
at 200~C for 15 minutes. The material expanded on the
plate in both a vertical and horizontal plane such that
the mix about doubled in volume.
EXAMPLE 6
A mix of 50 parts hot melt base from Example 5
above was mixed with 50 parts over-based calcium sulfonate.
The over-based calcium sulfonate was heated to evaporate
water from it prior to mixing it with the hot melt base.
The mixture was placed on a cold rolled steel plate
*Trade-mark
~B
~;
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~ ~a 1 16 45 8
~9~/061fi2 -16- PCT/US92/0807
and a cold rolled galvanized steel plate and heated
in an oven at 200~C for l5 minutes. The mix upon heating
melted and spread out over the plates without expanding.
Adhesion Comparison Examples 5 and 6
The material made in accordance with Example 6
~s tested for adhesion to cold rolled and galvanized
steel plates against the material made in accordance
with Example 5 above. The cured material of Example 5
above adhered much more strongly to the cold rolled
and galvanized steel plates than the material of Example 6.
It was found that the material of Example 6 was able
to be easily peeled from the plates while the material
made in accordance with Example 5 above ~the present
invention) did not easily peel.
EXAMPLE 7
A mix was made the same as Example 6 above, except
that water was not removed from the over-based calcium
sulfonate before mixing and placing it on the cold rolled
steel plate and cold rolled galvanized steel plate in
the oven at 200~C. The mix in this example simply hardened
in place. Curing was accelerated due to the water reIease
as evidenced by the lack of flowing or deformation of
the material placed on the sheets.
EXAMPLE 8
A mix was made the same as Example 5 above, except
that the mixture was not allowed to cool. The mix was
placed on a cold rolled steel sheet and a cold rolled
galvanized steel sheet and then placed in the oven at
200~C. This material expanded to about double in volume.
The blowing agent (water) was in the cyclodextrin and
was released upon heating along with the cyclohexylamine
(the vapor phase corrosion inhibitor). In the cyclodextrin,
the water is controlled and is not available for curing
until sufficient heat is applied to trigger its release.
~B,
~ WO93/~6162 2il61:58 PCT/US92~75
-17
EXAMPLE 9
A conventional sealant was made from:
Ingredient - Formula A Parts
Kraton RD 6501
(available from Shell) 100
Regalrez 1018
(available from Hercules) 270
; Endex 155
lavailable from Hercules) 50
Irganox 1010
(av~ilAhle from Ciba-Geigy)
This material was mixed and placed on cold rolled
steel and cold rolled galvanized steel sheets and placed
in an oven at 200~C for I5 minutes. This material melted
~ 15 and spread out on the plate.
EXAMPLE 10
- This example uses Formula A to make a sealant in
accordance with the present invention.
Inqredient Parts
Formula A 10
Beta cyclodextrin (10-13% water) ~ 2
These were mixed and placed on cold rolled steel
or cold rolled galvanized steel sheets and placed in
an oven at 200~C for 15 minutes. This sealant did expand
in volume, however, not by 100% of its initial volume.
Adhesion Comparison Examples 9 and 10
The adhesion to steel plates of the material made
in accordance with Example 9 was tested against the
adhesion of the material made in accordance with Example
10. It was found that the sealant of Example 10 (present
invention) adhered to the steel plate better than the
sealant of Example 9.
The sealant of Example 10 was also tested for relative
adhesion between cold rolled steel and galvanized steel.
- 35 It was found that the sealant of Example 10 adhered
- better to a cold rolled steel plate than to a galvanized
steel plate.
~ . -
F;21 1645 8
~O9~J~l~ -18- PCT/USg2/0807
EXAMPLE 11
This example illustrates using another chemical
blowing agent complexed with the cyclodextrin.
Ingredient Parts
5 Formula A 10
Beta cyclodextrin dibutyl tin dilaurate
complex (24% chemical blowing agent) 2
Beta cyclodextrin (10-13% water) 2
After mixing, these were placed on cold rolled steel
or cold rolled galvanized steel sheets and placed in an
oven at 200~C for 15 minutes. This material, upon heating,
also expanded, to about 100% of its initial volume.
Adhesive Comparison Examples 9 and 11
The adhesion to steel plates of the material made
lS in accordance with Example 9 was tested against the
adhesion of the material made in accordance with Example
11. It was found that the sealant of Example 11 (present
invention) adhered to the steel plate better than the
sealant of Example 9.
The sealant of Example 11 was also tested for relative
adhesion between cold rolled steel and galvanized steel.
It was found that the sealant of Example 11 adhered
better to a cold rolled steel plate than to a galvanized
steel plate.
EXAMPLE 12
This example illustrates the use of a complex of
beta cyclodextrin and benzoyl peroxide as both a blowing
agent and a curing agent for a thermoplastic. The following
compositions were made:
30 Composition Amount
A. Fusabond C-D198
(obtained from DuPont) 10 g
Beta cyclodextrin complex
of benzoyl peroxide
35(10% benzoyl peroxide) 1 g
B. Fusabond C-D198 10 g
C. Fusabond C-D198 10 g
Beta cyclodextrin '(10% water) 1 g
D. Fusabond C-D198 10 g
40Benzoyl peroxide 0.1 g
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WOg3/06162 . r 2 1 1 6 4 5 8 PCT/US92/0807~
1 9 -
Each composition was mixed while heating and while
still fluid was extruded into sheets of uniform thickness.
Portions of equal length and weight were cut from the
sheets and placed in an oven at 200~C.
During mixing of the uncomplexed benzoyl peroxide,
decomposition of the benzoyl peroxide occurred as evidenced
by the formation of bubbles. This was not observed
while mixing the complex of benzoyl peroxide and beta
cyclodextrin under the same conditions. The amount
of benzoyl peroxide was equal in both compositions.
In the complexed state, the benzoyl peroxide was stabilized
during mixing. It was also difficult to obtain a uniform
distribution of the uncomplexed benzoyl peroxide during
mixing. The beta cyclodextrin-benzoyl peroxide complex
was easily mixed and uniformly distributed during mixing
of the composition.
After heating, very noticeable differences were
noted. Composition D, containing uncomplexed benzoyl
peroxide,cured very rapidly and did not spread out laterally
to a great extent. Bubbles in the cured composition
were not of uniform size and distribution.
Composition A containing the beta cyclodextrin
complex of benzoyl peroxide also cured rapidly and did
not spread out laterally to a great extent. Blowing
and curing were occurring simultaneously. This composition
had raised higher than sample D containing uncomplexed
benzoyl peroxide. Bubbles in composition A were of
uniform size and distribution.
Composition C spread laterally more than any of the
other compositions. Water released from the cyclodextrin
f'ormed bubbles of uniform size and distribution. The
water released was acting as a traditional blowing agent
but no curing agent was present to cure the composition
to retard spreading.
Composition B spread out laterally more than
compositions A and D but not as much as Composition C.
No curing agent was present which would retard spreading
and no blowing agent was present which would increase
~B
Y~D9~6162
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spreading.
The best results were obtained from Composition A
containing'the eomplex of benzoyl peroxide and beta
- eyelodextrin. The benzoyl peroxide was stabilized to
be released upon heating to act both as a curing agent
and a blowing agent. The eomplex was also easily mixed
into and dispersed in the composition.
It will be understood that it is intended to cover
all changes and modifieations of the preferred embodiment
of the invention herein ehosen for the purpose of
illustration whieh do not eonstitute a departure from
the spirit and seope of the invention.
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