Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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US. Letters Patent No. 3,708,379 and 3,837,981 describe
elastomeric tape and epoxy tape, respectively. The epoxy tape
described particularly in the latter patent is marketed commercially
5 as an adhesive sealant for a wide variety of applications.
A commercial form of epoxy tape made in accord wit Patent No.
3,837,981 has a band of uncured epoxy ribbon which is brilliant blue
in close side-by-side relation with a band of a curing composition
which is yellow. When substantially equal portions of the two bands
10 of material are mixed to form a uniform mixture, an adhesive sealant
is formed which may be applied or used for any desired purpose. the
adhesive-sealant formed on uniform mixing of substantially equal
portions of the epoxy resin and curing agent compositions has a putty-
like consistency, and when used to adhere or seal has inherent ability
15 to stay where it is applied even without support or clumping means to
hold the objects being adhered together during the time required for
the curing of the epoxy resin.
Epoxy tape products made in accord with Patent No. 3,837,981 may
be lo D fated so as to fully cure to a solid epoxy adhesive in
20 approximately four to twenty-four hours. For general applications the
time required for curing of the adhesive sealant is practical and not
objectionable.
As will be appreciated, there are instances when it is desircible
to have an extremely fast curing epoxy adhesive sealant, that is, one
25 which may be applied and cure in a matter of a few minutes rather than
hours. Fast curing epoxy adhesive sealants are known, however, such
products have not heretofore been known to exist in a form similar to
that illustrated in Patent No. 3,837,981. Typically, fast curing
epoxy adhesive sealants exist in liquid form where one combines a
30 portion of a liquid epoxy resin with a portion of a liquid curing
agent. The disadvantages of such products are obvious, and include
the problem of cross contamination of the epoxy resin and curing agent
which could result in loss of the supply of each component and the
necessity for packaging each component separately with the expense
35 inherent in this procedure.
err exists, therefore, a need in the art for a fast cure epoxy
adhesive sealant of the type illustrated in Patent No. 3,837,981. In
I
other words, there exists a need for a East cure epoxy adhesive
sealant having a putty-like consistency described in the aforesaid
patent, a product which does not need special storage conditions or
packaging and one which is available for use immediately through the
5 simple expediency of hand mixing. It is not necessary that the
product of this invention be in any particular configuration
illustrated in Patent No. 3,837,981 although the product may exist in
the side-by-side configuration depicted in that patent, or in any form
in which the respective bands are in reasonably continuous form even
lo though there is no actual touching of the bands in side-by-side
relationship. mix need has not been satisfied heretofore because of
the nature of the agents necessary to accomplish relatively fast cure
of epoxy resins. Typically, such fast cure agents are extremely air
sensitive, being rendered unsuitable for use by oxygen, humidity or
15 other components of the atmosphere. must it has not been possible to
make use of fast curing agents unless they have been packaged in
containers which are impervious to the atmosphere.
The present invention has satisfied the need in the art for a
fast cure epoxy adhesive sealant which is in putty form, protected
20 from adverse effects of the atmosphere and useful by simple mixing and
molding techniques.
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Description of the Invention
According to this invention, a putty like room temperature, fast
cure adhesive sealant comprising a first band of an uncured reactive
polymer or resin adhesive sealant composition and a second band, said
5 second band comprising a composition capable of curing or polymerizing
said uncured reactive polymer or resin composition when said first and
second bands are combined to form a substantially uniform mixture, is
improved wherein said second band comprises an agent capable of curing
or polymerizing said uncured reactive resin or polymer to a hard
lo adhesive sealant within about ten minutes from the time when said
uncured resin or polymer composition and said curing cc~position are
combined to form a substantially uniform mixture.
no preferred embodiments of this invention encompass a
formulation of an uncured epoxy resin and curing aunt capable of
15 forming a useful adhesive sealant within about five minutes after
mixing to a Shore A hardness of 30.
In the appended drawings, Fig. l is a plan view illustrating an
embodiment of the rapid cure adhesive sealant of this invention, Figs
2, 4 and 5 are cross-sectional views of embodiments of the invention,
20 while Fig. 3 is a cross-sectional view taken along 3-3 of Fig. l.
The room temperature, fast cure adhesive sealant of this
invention has to principal components. First, it includes an uncured
reactive polymer or resin, and second, a curing system for the
reactive polymer or resin. In preferred embodiments, epoxy resins
25 which are complex polymeric reaction products of polyhedra phenols
with polyfunctional halohydrins, are used. Useful epoxy resins are
described more cc~pletely in Patent No. 3,837,98l. Useful reactive
polymers include styrenes resins which are cure by free radical
polymerization with organ peroxide curing agents. Also silicone
30 adhesive sealants where the silicone polymer would be cured by
moisture sensitive organ tin cross linking agents are encased by
this invention.
While this invention encompasses room temperature, fast cure
adhesive sealants encompassing polyester and silicone resins, it will
35 be described in detail with respect to epoxy resin adhesive sealant
compositions. Ire curing system for the uncured epoxy resin
compositions useful in this invention comprises two components, each
Sue
being a curing agent for epoxy resins. Polyamide compositions are
typically used as curing agents for polyamide resins.
As is known, specific epoxy resins react differently with
specific curing agents. One can vary the time required for complete
5 curing of an epoxy resin by versing the specific polyamide curing
agents and/or varying the amount of polyamide curing agent. Curing
agents which can be expected to provide a rapid or fast cure of an
epoxy resin, i.e., a cure which is complete within about -ten minutes
from the time when the epoxy resin composition and curing composition
10 are combined to form a substantially uniform mixture, are generally
recognized as being relatively air sensitive. Air sensitive epoxy
resin curing systems generally comprise liquid polymercaptan polymers
and accelerators such-as an amino phenol, which undergo such
degradation as to lose their ability to cause curing of an epoxy resin
15 as the result of interaction with the atmosphere. It has been found
that a room temperature fast cure epoxy resin adhesive sealant may be
formulated using only a polymercaptan curing agent, and curing will be
effected within about 5 to about 10 minutes. It has also been found
that adhesive sealants in which curing occurs in 5 minutes or less may
20 be formulated if the curing agent includes accelerators as jell as the
polymercaptan polymer.
m e fast cure curing agent, i.e. a curing agent effective to
cause curing of the epoxy resin used in the epoxy tape of this
invention within about ten minutes, may comprise a liquid
25 polymercaptan polymer and/or an amino phenol. Epoxy resins have been
cured with polymercaptan-aminophenol curing agent systems in the past.
The air sensitive nature of such curing systems, and their liquid
form, has heretofore made it impossible to use such curing systems in
epoxy tape products of the type described in Patent No. 3,837,981.
Liquid polymercaptan polymers useful in the fast cure curing agent of
this invention include those having a mercaptan value
(milliequivalents per gram), of 1 to 20, preferably 3 to 4. Such
polymers are available commercially under the trademark Capture from
Diamond Shamrock, Inc.
In en*xxlL~ents where extremely rapid cure (less than five
minutes) is desired the liquid polymercaptan polymer is combined with
an amino phenol. Useful amuses are available commercially under the
trade names DYE 30 and Do 10 from Room & Hays Company. The
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polymercaptan polymer and amino phenol may be combined in a ratio of
from about 20:1 to bout 5:1, preferably about 6:1 to form the fast
cure curing agent of this invention. It is possible -that either the
polymercaptan or the amino phenol components could be used alone to
5 effect cure of the epoxy resin present in the compositions of this
invention. However, a significant attribute of the invention lies in
the fact that the adhesive sealant may be mixed and applied by hand.
It is kin that the amino phenol curing agents may cause skin
irritation, thus it is desired -to minimize contact of these agents
10 with the skin. Accordingly, the amino phenol curing agents are used
only in those levels sufficient to effect Requiem temperature rapid cure
within the desired 10 minute period. This may be accomplished so long
as the curing agent comprises I by weight or less of the amino phenol
cc~nponent.
me polymercaptan polymer and amino phenol fast cure curing agents
are rather low viscosity liquids, and they are air sensitive compounds
as stated Ahab. These components are made useful in an epoxy type
product of the type described in Patent No. 37837,981 by cabining
them with components to provide compositions having physical
20 properties required for forming a potluck product. Thus, the fast
cure curing agent may be ec~nbined with various fillers, plasticizers
colorants and other special purpose ingredients. In preferred
embcd:hr~nts, the low viscosity liquid fast cure curing agent is
eambined with a high viscosity polyamide resin or blend of polyamide
25 resins in a ratio of about 1:1 to about 2-1, and an inert carrier such
as tale to form a putty-like composition which nay be extruded in tape
form.
While the blend of room temperature fast cure curing agent and
polyamide rosin described above may have a putty-like consistency so
30 as to be amenable to extrusion in tape form, it is air sensitive, and
thus is not amenable to use as curing agent for an epoxy resin in the
embodiments depicted and described in Patent No. 3,833,g81. Such a
product is unlike that depicted in Fig. 4 of Patent No. 3,837,981
ea~prising epoxy resin base and curing agent. The amount of polyamide
35 curing agent required for this purpose is not critical so long as the
room tRImperature fast cure curing agent is protected from exposure to
the atmosphere. This is generally accomplished by enveloping the
putty-like room temperature, fast cure curing agent with a layer of
9Ç;9-'~
polyc~mQde curing agent from about 0.5 to 2 mm in thickness Any inert
putty like material which is compatible with the epoxy resin may be
useful in forming the protective envelope. The envelope can be
applied by mutual extrusion of the room temperature fast cure curing
5 agent and polyc~lide or the curing agent could be placed in a molten
polyamide resin bath from which a coating of the polyamide would
adhere to the curing agent.
Fig. 2 illustrates an epoxy tape in which Band B contains the
epoxy resin composition, band A contains the fast cure curing agent
10 and band C contains the polyamide resin curing composition which
serves to protect the fast cure curing agent from atmospheric
degradation. Alternative embodiments of the invention are depicted in
Figs. 3, 4 and 5. Fig 4 depicts an alternative embodiment in which
one strip (B) comprises the epoxy resin, while the other comprises the
15 room temperature fast cure curing agent (A) and the polyamide resin
curing composition (C) which serves to protect the room temperature,
fast cure curing agent from atmospheric degradation. In such form,
the separate strips are carried on release paper or other carrier and
packaged as a single unit.
Fig. 5 illustrates an embodiment in which curing agent A and
epoxy resin s are each wrapped or enveloped by the polyamide curing
composition C. This may be accomplished by extrusion of the
materials, or, alternatively, bands A and B could be placed in a bath
of molten polyamide curing composition from which the curing
25 composition C will adhere to bands A and s in the form depicted in
Fig. 5. In this embodiment as well as those illustrated in the other
figures, it will be appreciated that the curing composition C
functions in a manner analogous to a container, and is unique in this
role, since it becomes part of and is consumed with use of the
30 adhesive sealant, and yet does not have to be removed or segregated
from the adhesive-sealant prior to use.
Figs. 1 and 3 illustrate a method of sealing ends of the epoxy
tape before and after removal of portions of the tape for use as an
epoxy adhesive sealant so as to maintain the protective shield about
35 the air sensitive room temperature fast cure curing agent.
The room temperature curing agent, whether in the form of
polyamide, polymercaptan and/or amino phenol, should be present in an
amount sufficient to cross link from about 80 to about 120%, preferably
I
about 100%, of the available cross-linking sites of the epoxy resin in
the tape.
As mentioned, the epoxy resin and the curing agent therefore are
admixed with various fillers, plasticizers, and colorants to form the
5 putty like compositions which are extruded into separate shapes or
into an epoxy tape of the type described in Patent No. 3,837,981~
IJseful fillers for this purpose include talc, powdered alumina and
asbestos fiber. Fillers such as these provide the epoxy resin and the
curing agent compositions with physical properties and the putty-like
10 consistency necessary for extrusion into tape form. The fillers are
incorporated into the epoxy resin and the curing agent compositions in
amounts sufficient to produce a putty-like mass which can be easily
extruded into the desired epoxy tape. Pc~7dered talc such as Mist Ron
Vapor available cc~rnercially from United Sierra Division of Cypress
15 Mines Corporation, is an especially preferred filler, since it yields
a handle able putty-like mass with both epoxy resins and the curing
agent compositions Putty-like products prepared with this filler
skew less tendency to stick to the hands than do compositions prepared
with other fillers. Useful plasticizers include resinous polyols and
20 other agents which serve to yield a more flexible cured product.
A variety of coloring agents may be included in the epoxy or the
curing agent compositions as desired. Useful coloring agents include
pigments like titanium dioxide which provides a white color; carbon
black or black color end various organic and inorganic pigments for
25 o'er colors It it desirable that the respective hands of epoxy
resin and curing agent composition be of contrasting color to serve as
an indicator of complete and thorough mixing.
rho use the room temperature, fast cure products of this
invention, a portion of the tape comprising substantially equal
30 lengths of the epoxy resin band and the curing agent band is selected
and the compositions are mixed together. The mixing may be
acc~nplished by hand or with the aid of mechanical assistance. Mixing
permits the components, i.e. the epoxy resin and the room temperature
fast cure curing agent, to react and effect curing, in situ. Zen the
35 epoxy resin and the room temperature fast cure curing agent bands of
the tape are of contrasting color, it is easy to determine when a
uniform mixture has been obtained simply by continuing mixing until
9Çi
the mixture has a uniform color. I-t will be appreciated that pigment
may be included in one or both buds of the composition.
me overall extrusion process for preparing the products of this
invention is analogous to that described in Patent No. 3,837,981. In
5 this process, the respective putty-like compositions may be extruded
from three extrudes which lay down the respective bands illustrated
in Figs. 2 and 4. After extrusion, any desired length of the tape may
be simply rolled up and packaged in any desired manner. mere is no
need for special packaging requirements to give a useful shelf life to
10 the tape. when the epoxy tape of this invention is used as an
adhesive sealant, any desired quantity of the epoxy tape made of
approximately equal lengths of each band in the tape are selected and
kneaded together under ambient conditions forming a uniform mixture.
The resulting putty-like or dough-like epoxy adhesive sealant has a
15 relatively short pot life and must be applied rather promptly as
substantial curing is effected at ambient temperatures within about
ten minutes from the time when the epoxy resin composition and the
room temperature fast cure curing composition are combined to form a
substantially uniform mixture. mere must be some time after mixing
20 by hand in which the product remains workable for each application.
Accordingly, the product is formulated so that substantial curing to
the point of unw~rkability by hand occurs within about 5 minutes from
the time of mixing. mix point is characterized by a Dormitory
hardness shore A) of 30. The product reaches a Shore A of 60 within
25 10 minutes from time of mixing, and thus is an extremely rapid, room
temperature curing adhesive sealant.
The epoxy formed from the epoxy tape of this invention
substantially cures within ten minutes or less from the time of
initial mixing to a useful, tough, solid, epoxy adhesive. me epoxy
30 resin formed from the epoxy tape with this invention has excellent
adhesive-sealant properties, and may be utilized to adhere ceramic,
wood and metal and like materials to aluminum, concrete, steel,
ceramic and like substances. The epoxy composition will cure under
water making it useful in many marine environments. me invention may
35 be illustrated in the following example:
Lowe
EXAMPLE 1
471 parts of an epoxy resin Eon 828) having an epoxy
equivalent weight of 185 to 192 are mixed with 525 pounds of powdered
talc, Mist Ron Vapor by United Sierra Division of Cypress Mines
Corporation, forming a highly viscous, smooth material.
A curing agent composition is prepared by mixing 17 parts of a
semisolid polyamide resin having an amine value of 90 and a viscosity
of 10 poises at 150C. (Versamid~ 100 of General Mills) with 30 parts
of a liquid polyamide resin having an amine value of 200 to 300
(Assumed 215 of A Chemicals, Inc.), with 60 parts of powdered talc
10 list Ron Vapor ) in a sigma blade mixer maintained at a temperature
not exceeding 120F. until a uniform mixture is formed. A third
mixture is prepared by mixing 30 parts of a semisolid polyamide resin
having an amine value of 90 and a viscosity of 10 poises at 150C.
(Versamid~ 100), with 48 parts of liquid polymercaptan polymer having
15 a mercaptan value of 3.6 milliequivalents per gram tcapcure~ of
Diamond Shamrock), 8 parts of amino phenol DUMP 10 of Room & Hays) and
100 parts of powdered talc (Mist Ron Vapor ) in a able arm putty
mixer maintained at a temperature not exceeding 120F. until a uniform
mixture is formed. Substantially equal portions, by weight, of each
20 of the three mixtures are formed into slugs and fed separately into
extrudes which simultaneously lay dawn bands of each mixture in the
form depicted in the drawings. A room temperature fast curing epoxy
adhesive is formed which will substantially cure to Shore A hardness
of 30 within about 5 minutes after initial mixing.
