U.S. patent application number 12/784782 was filed with the patent office on 2010-09-16 for novel adducts and curable compositions using same.
This patent application is currently assigned to Loctite (R&D) Limited. Invention is credited to Barry N. Burns, Martin J. Fitzpatrick, Mark Loane, Ciaran B. McArdle, Rainer Schoenfeld, Ray P. Tully, Jonathan P. Wigham.
Application Number | 20100234516 12/784782 |
Document ID | / |
Family ID | 38983982 |
Filed Date | 2010-09-16 |
United States Patent
Application |
20100234516 |
Kind Code |
A1 |
Burns; Barry N. ; et
al. |
September 16, 2010 |
NOVEL ADDUCTS AND CURABLE COMPOSITIONS USING SAME
Abstract
The present invention relates to novel adducts useful for
improving the toughness and curable compositions using such
toughening adducts. In a particular aspect, the present invention
relates to novel toughening adducts and curable compositions having
improved fracture toughness using those toughening adducts.
Inventors: |
Burns; Barry N.; (Killiney,
IE) ; Tully; Ray P.; (Slane, IE) ; Wigham;
Jonathan P.; (Dublin, IE) ; Fitzpatrick; Martin
J.; (Dublin, IE) ; Schoenfeld; Rainer;
(Duesseldorf, DE) ; McArdle; Ciaran B.; (Dublin,
IE) ; Loane; Mark; (Dublin, IE) |
Correspondence
Address: |
Loctite Corporation
One Henkel Way
Rocky Hill
CT
06067
US
|
Assignee: |
Loctite (R&D) Limited
Dublin
IE
Henkel AG & Co, KGaA
Duesseldorf
DE
|
Family ID: |
38983982 |
Appl. No.: |
12/784782 |
Filed: |
May 21, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12410009 |
Mar 24, 2009 |
7750094 |
|
|
12784782 |
|
|
|
|
PCT/IE2007/000087 |
Sep 25, 2007 |
|
|
|
12410009 |
|
|
|
|
Current U.S.
Class: |
524/500 ;
525/474 |
Current CPC
Class: |
C07C 253/30 20130101;
C07C 253/30 20130101; C07C 251/30 20130101; C07C 255/23
20130101 |
Class at
Publication: |
524/500 ;
525/474 |
International
Class: |
C08L 83/06 20060101
C08L083/06 |
Claims
1-11. (canceled)
12. An adduct represented by the structure: ##STR00040##
13. A curable composition comprising: a. a thermosetting component;
b. an adduct according to claim 12.
14. The composition of claim 13, wherein the thermosetting
component is a member selected from the group consisting of
epoxies, episulfides, benzozaxines and combinations thereof.
15. The composition of claim 13, further comprising a toughener.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to novel adducts useful for
improving toughness, and curable compositions using such adducts.
The novel adducts may improve toughness, such as in terms of impact
resistance, and/or adhesion in curable compositions using those
adducts.
[0003] 2. Brief Description of Related Technology
[0004] Toughness generally is the ability of a material to absorb
energy and undergo large permanent set without rupture. For many
engineering adhesive applications, toughness is often the deciding
factor. Plastics, because of their inherent brittleness, have
heretofore been modified in a variety of ways in efforts to improve
the toughness thereof. Epoxy resins, for example, which form a
versatile glassy network when cured, exhibit excellent resistance
to corrosion and solvents, good adhesion, reasonably high glass
transition temperatures (T.sub.g) and adequate electrical
properties. Unfortunately, however, the poor fracture toughness of
epoxy resins oftentimes limits the usefulness thereof in many
commercial applications.
[0005] The impact strength, as well as other physical properties of
crosslinked epoxy resins, is controlled by the chemical structure
and molecular weight of the epoxy resin, weight ratio of the epoxy
resin to the hardener, by any added fillers, and by the conditions
used to cure the formulation. Unfortunately, crosslinked, glassy
epoxy resins with a relatively high glass transition temperature
("T.sub.g") (>100.degree. C.) are brittle in nature. The poor
impact strength of high glass transition epoxy resins limits their
usage as structural materials and use in or as composites.
[0006] Conventional toughening agents (e.g., carboxyl terminated
butadiene nitrile rubbers, "CTBN") are frequently unsuitable as
additives in formulations where low temperature crash impact
performance is desired.
[0007] Carbonyl biscaprolactam, such as is available commercially
under the ALLINCO brand name from DSM Research, has been reported
as a versatile, nontoxic reagent that converts hydroxy and amino
groups of functional polymers into the corresponding
caprolactam-blocked isocyanates without requiring the use of
isocyanates. See Angew. Chem. Int. Ed., 42, 5094-5097 (2003). For
instance, in the context of primary amines, see the following
reaction scheme I:
##STR00001##
[0008] In addition, U.S. Pat. No. 5,278,257 (Mulhaupt) and
International Patent Publication No. WO 2005/007766 A1 describe the
preparation of a rubber modified epoxy composition containing a
phenol-capped polyurethane pre-polymer as a toughening agent. The
so-described toughening agents are believed to be the basis of the
BETAMATE-brand product offering from Dow Automotive.
[0009] The low temperature performance properties of such
BETAMATE-brand products could stand improvement. In addition,
consumers would benefit from the offering of additional adducts and
products using such adducts having different or more desirable
physical property performance.
[0010] Accordingly, there is a need for novel adducts that are
effective for improving the toughness of adhesive formulations,
especially in formulations requiring good low temperature
performance, and which formulations are based on thermosets such as
epoxy, episulfides and/or benzoxazines.
SUMMARY OF THE INVENTION
[0011] In accordance with the present invention, there are provided
novel adducts which are useful for improving the performance
properties of thermosetting resin formulations, such as those based
on epoxy, episulfide, benzoxazine and combinations thereof. The
performance properties include improved impact resistance and
adhesion to substrate surfaces.
[0012] The novel adducts may be represented by compounds within
general formula I.
##STR00002##
where R and R' are each independently selected from polyethers,
such as polypropylene glycol ("PPG") and polyTHF, perfluorinated
polyethers ("PFP"), JEFFAMINE type backbones (as more fully
described below), polydimethylsiloxane ("PDMS") backbones (again,
as more fully described below), LP3 type backbones (as more fully
described below), and hydroxy terminated polybutadiene ("HPBD")
backbones, provided however that when R is PPG, R' is not PPG or X
is not ArO;
[0013] Z and Z' are each independently selected from
--CH.sub.2-K-(NH).sub.(0,1)CO--, where K is C.sub.1-C.sub.70 linear
or branched alkylene or alyleneoxy, C.sub.5-C.sub.12 cycloalkylene
or cycloalkyleneoxy, or C.sub.6-C.sub.15 arylene or aryleneoxy;
[0014] X is selected from ArO--, ArO--C.dbd.O, or mercapto- or
amino-functionalized alkylene or alkylenoxy urea, urethane or
thiourethane, where Ar is for example phenyl, biphenyl, bisphenol
A, bisphenol F, bisphenol S, bisphenol E, allyl, alkyl, alkenyl,
carboxy, N-carbamoyl functionalized five to seven membered cyclic
amides, epoxy ether or hydroxyl-functionalized ether; and
[0015] y is 1-4, and x is 1-3.
[0016] The novel adducts may be represented by compounds within
general formula II.
##STR00003##
where X, Z, R and y are as defined above.
[0017] For epoxy functionalized adducts, they may be represented by
compounds within general formula III.
##STR00004##
where M is an alkylene, cycloalkylene, or arylene linkage;
[0018] J is a linkage such as hydroxyalkylene (such as hydroxy
ethylene), --OC.dbd.O, or a ring structure with L such as,
##STR00005##
[0019] L is H or a ring structure with J as described above;
and
[0020] R, Z', R', x and y are as defined above.
[0021] For phenol-functionalized adducts, they may be represented
by compounds within general formula IV.
##STR00006##
where Ar is an aryl group, and R, Z', R', x and y are as defined
above.
[0022] For N-carbamoyl functionalized five to seven membered cyclic
amide adducts, they may be represented by compounds within general
formula V.
##STR00007##
where R, Z', R', n, x and y are as defined above.
[0023] In order to improve low temperature fracture toughness
performance properties, while conferring improved adhesion on
substrates, such as steel, the inventive adducts should also have a
low Tg value, such as below room temperature, desirably -20.degree.
C. and more desirably -40.degree. C. or lower. In addition, other
physical properties of the adduct may contribute to such low
temperature performance, such as compatibility with the thermoset
matrix and solubility parameters generally. To that end, the level
of PDMS in R of the adduct, for instance, may be adjusted if
desired within the range of about 5 to about 95%, such as about 20
to about 80%, desirably about 20% by weight of R in the adduct, to
provide the adduct with the desirable Tg, particularly for
improving wedge impact performance and improved adhesion. To the
extent that R in the adduct is composed of a second (or third)
backbone, the remaining portion of R may be a
non-silicon-containing segment, such as one derived from a
polypropylene glycol, of course bearing (meth)acrylate
functionalization.
[0024] Adducts within formula I have been found to be useful as
additives in one part thermosetting resin compositions, so as to
improve physical properties, such as tensile peel strength values,
tensile shear strength values and wedge impact properties.
DETAILED DESCRIPTION OF THE INVENTION
[0025] As noted above, the present invention provides novel adducts
which are useful for improving the performance properties of
thermosetting resin formulations, such as those based on epoxy,
episulfide, benzoxazine and combinations thereof.
[0026] The novel adducts may be represented by compounds within
general formula I.
##STR00008##
where R and R' are each independently selected from polyethers,
such as PPG and polyTHF, PFP, JEFFAMINE type backbones, PDMS
backbones, LP3 type backbones, and HPBD backbones, provided however
that when R is PPG, R' is not PPG or X is not ArO;
[0027] Z and Z' are each independently selected from
--CH.sub.2-K-(NH).sub.(0,1)CO--, where K is C.sub.1-C.sub.70 linear
or branched alkylene or alyleneoxy, C.sub.5-C.sub.12 cycloalkylene
or cycloalkyleneoxy, or C.sub.6-C.sub.15 arylene or aryleneoxy;
[0028] X is selected from ArO-, ArO-C.dbd.O, or mercapto- or
amino-functionalized alkylene or alkylenoxy urea, urethane or
thiourethane, where Ar is for example phenyl, biphenyl, bisphenol
A, bisphenol F, bisphenol S, bisphenol E, allyl, alkyl, alkenyl,
carboxy, N-carbamoyl functionalized five to seven membered cyclic
amides, epoxy ether or hydroxyl-functionalized ether; and
[0029] y is 1-4, and x is 1-3.
[0030] The novel adducts may be represented by compounds within
general formula II.
##STR00009##
where X, Z, R and y are as defined above.
[0031] For epoxy functionalized adducts, they may be represented by
compounds within general formula III.
##STR00010##
where M is an alkylene, cycloalkylene, or arylene linkage;
[0032] J is a linkage such as hydroxyalkylene (such as hydroxy
ethylene), --OC.dbd.O, or a ring structure with L such as,
##STR00011##
[0033] L is H or a ring structure with J as described above;
and
[0034] R, Z', R', x and y are as defined above.
[0035] For phenol-functionalized adducts, they may be represented
by compounds within general formula IV.
##STR00012##
where Ar is an aryl group, and R, Z', R', x and y are as defined
above.
[0036] For N-carbamoyl functionalized five to seven membered cyclic
amide adducts, they may be represented by compounds within general
formula V.
##STR00013##
where n is 0-2 and R, Z', R', x and y are as defined above.
[0037] With reference to the building blocks used to prepare the
inventive adducts, the linkage represented by "R" and "R'" may be
formed from polyethers and polythioethers functionalized with one
or more of hydroxy, mercapto and amino groups. Such polyethers may
originate from commercially available starting materials, for
instance the amine-functionalized polyethers sold under the
JEFFAMINE tradename, the mercapto-functionalized polythioethers
sold under the LP-3 tradename and/or the hydroxy-functionalized
polyethers, sold under the trade designation, PPG.
[0038] Each of these different functionalized polyethers and
polythioethers are available commercially, or can be prepared, in a
variety of molecular weights. With the different molecular weights,
physical property changes can be imported into the inventive adduct
to tailor the adduct for the specific end use application for which
it is intended to be used.
[0039] Amine-functionalized polyethers include oxyethylene
diamines, oxyethylene triamines, polyoxyethylene diamines,
polyoxyethylene triamines, oxypropylene diamines, oxypropylene
triamines, polyoxypropylene diamines, polyoxypropylene triamines,
dimethylene glycol dipropyl amine and/or derivatives and adducts
thereof, and combinations thereof.
[0040] Commercially available examples of such polyether
amine-based hardeners--amine-functionalized polyethers--include
those from BASF Corporation, Mt. Olive, N.J., under the trade
designation 4,7,10 TTD, and Huntsman Corporation, Houston, Tex.,
under the JEFFAMINE tradename, such as JEFFAMINE D-230, JEFFAMINE
D-400, JEFFAMINE D-2000, JEFFAMINE T-403, JEFFAMINE ED-600,
JEFFAMINE ED-900, JEFFAMINE ED-2001, JEFFAMINE EDR-148, JEFFAMINE
XTJ-509, JEFFAMINE T-3000, JEFFAMINE T-5000, and combinations
thereof.
[0041] The JEFFAMINE D series are diamine based products and may be
represented by
##STR00014##
where x is about 2.6 (for JEFFAMINE D-230), 5.6 (for JEFFAMINE
D-400) and 33.1 (for JEFFAMINE D-2000), respectively.
[0042] The JEFFAMINE T series are trifunctional amine products
based on propylene oxide and may be represented by
##STR00015##
where x, y and z are set forth below in Table A.
TABLE-US-00001 TABLE A Approx. Mole JEFFAMINE Initiator (A) Mol. Wt
PO T-403 Trimethylolpropane 440 5-6 T-3000 Glycerine 3,000 50
T-5000 Glycerine 5,000 85
[0043] More specifically, the JEFFAMINE T-403 product is a
trifunctional amine and may be represented by
##STR00016##
where x+yd-z is 5.3 (CAS Registry No. 39423-51-3).
[0044] The JEFFAMINE ED series are polyether diamine-based products
and may be represented by
##STR00017##
where a, b and c are set forth below in Table B.
TABLE-US-00002 TABLE B Approx. Value Approx. JEFFAMINE b a + c Mol.
Wt ED-600 8.5 2.5 600 ED-900 15.5 2.5 900 ED-2001 40.5 2.5
2,000
[0045] As the mercapto-functionalized polythioethers, many
materials may be used. For instance, polysulfides of the general
formulae may be used
##STR00018##
where R is an alkyl ether, such as
--(CH.sub.2).sub.2--O--CH.sub.2--O--(CH.sub.2).sub.2--, and
a+b+c=n.
[0046] A particularly desirable material is known as THIOKOL LP-3,
available commercially from Rohm and Haas Company, Philadelphia,
Pa., where n is 6 and about 2 mole percent branching exists. LP-3
is also reported to have a molecular weight of about 1,000.
[0047] Another particularly desirable material is available
commercially from Akcros Chemicals, Manchester, Great Britain under
the tradename THIOPLAST, such as G1 (n is 19-21, 1.8-2 percent
thiol content, and a 3,300-3,700 molecular weight), G4 (n is less
than 7, less than 5.9 percent thiol content, and less than 1,100
molecular weight), G12 (n is 23-26, 1.5-1.7 percent thiol content,
and a 3,900-4,400 molecular weight), G21 (n is 12-15, 2.5-3.1
percent thiol content, and a 2,100-2,600 molecular weight), G22 (n
is 14-18, 2.1-2.7 percent thiol content, and a 2,400-3,100
molecular weight), G112 (n is 23-25, 1.5-1.7 percent thiol content,
and a 3,900-4,300 molecular weight), and G131 (n is 30-38, 1.5-1.7
percent thiol content, and a 5,000-6,500 molecular weight). The
THIOPLAST materials are reported to be prepared from the
polycondensation of bis-(2-chloro-ethyl) formal with alkali
polysulfide.
[0048] (Meth)acrylate-functionalized polydimethyl siloxanes of
various molecular weights may be used as the building block for
this portion of the adduct, as well.
[0049] Commercial sources for such (meth)acrylate-functionalized
polydimethyl siloxanes include Genesee Silicone, Gelest Silicone
and Wacker Silicones. For instance, methacryloxypropyl terminated
PDMS [molecular weight 900-1200] is available from Gelest under the
trade designation DMS-R11, methacryloxymethyl terminated PDMS
[molecular weight .about.1360] is available from Wacker under the
trade designation SLM 446016-15 VP, 3-acryloxy-2-hydroxypropyl
terminated PDMS [molecular weight 1000-1250] is available from
Gelest under the trade designation DMS-U22, acryloxy terminated
ethylene oxide PDMS [molecular weight 1500-1600] is available from
Gelest under the trade designation DBE-U12 and from Goldschmidt
under the trade designation TEGO V--Si 2250 [molecular weight
.about.2500].
[0050] Again, the different molecular weights of this segment
impact desirable physical properties of the adduct, so that the
resulting adduct may be more or less suitable for a variety of end
use applications.
[0051] A polyalkylene glycol, such as polypropylene glycol
[available commercial from Aldrich Chemical Co., molecular weight
.about.10,000] may also be used as a building block of the
inventive adduct. Here, too, different molecular weights of this
segment impact desirable physical properties of the adduct, so that
the resulting adduct may be more or less suitable for a variety of
end use applications.
[0052] These materials may be used as building blocks individually
or they may be used in various combinations. The intended end use
application will suggest to those of ordinary skill in the art
whether to choose one or the other or a combination to provide the
physical property set beneficial to that end use application.
[0053] Thus, for instance in order to prepare the inventive adduct
with polyurethane segments, a polyol, such as trimethylol propane,
would be reacted under mildly elevated temperature conditions with
an isocyanate, desirably a polyisocyanate, such as hexamethylene
diisocyanate, in the presence of the building block(s) of the R and
R' segments.
[0054] Isocyanates suitable for use in this adduct building
reaction include polyisocyanates, such as a diisocyanate (for
instance an aliphatic, cycloaliphatic, aromatic or araliphatic one)
or triisocyanate, or, if desirable, in combination with chain
lengtheners (short-chain polyhydroxyl, polysulfhydryl or polyamine
compounds), or a polyisocyanate prepolymer derived from a
prepolymer polyamine, such as a prepolymer polyetheramine.
[0055] A variety of diisocyanates are useful for reaction in this
regard and the choice of any particular one will be left to those
persons of ordinary skill in the art, likely to be dictated in part
by the commercial availability and in part by the end use
properties desired.
[0056] Useful diisocyanates include ethylene diisocyanate,
trimethylene diisocyanate, tetramethylene diisocyanate,
pentamethylene diisocyanate, hexamethylene diisocyanate,
heptamethylene diisocyanate, octamethylene diisocyanate,
decamethylene diisocyanate, dodecamethylene diisocyanate,
tetradecamethylene diisocyanate, hexadecamethylene diisocyanate,
octadecamethylene diisocyanate, eicosamethylene diisocyanate,
cyclohexamethylene diisocyanate, cyclopenthalene diisocyanate, or
cyclohepthalene diisocyanate, or bis-cyclohexylene,
cyclohexylmethylene diisocyanate, tetramethylxylylene diisocyanate,
phenyl diisocyanate, toluene diisocyanate (such as
2,4-diisocyanatotoluene and 2,6-diisocyanatotoluene), 4,4'-diphenyl
diisocyanate, 4,4'-diphenylene methane diisocyanate, dianisidine
diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenyl ether
diisocyanate, p-phenylene diisocyanate, 4,4'-dicyclo-hexylmethane
diisocyanate, 1,3-bis-(isocyanatomethyl)cyclohexane, cyclohexylene
diisocyanate, tetrachlorophenylene diisocyanate,
2,6-diethyl-p-phenylenediisocyanate,
3,5-diethyl-4,4'-diisocyanatodiphenyl-methane, tetramethylene
diisocyanate, hexamethylene diisocyanate, ethylene diisocyanate,
cyclohexylene diisocyanate, nonamethylene diisocyanate,
octadecamethylene diisocyanate, 2-chloropropane diisocyanate,
2,2'-diethylether diisocyanate, 3-(dimethylamine) pentane
diisocyanate, tetrachlorophenylene diisocyanate-1,4,3-heptane
diisocyanate and transvinylene diisocyanate.
[0057] Additional examples of suitable isocyanates are urethanized
4,4'-diisocyanatodiphenylmethane, carbodiimidized
4,4'-diisocyanatodiphenylmethane, the adduct formed from
diisocyanatotoluene and trimethylolpropane, the trimer formed from
diisocyanatotoluene, diisocyanato-m-xylylene,
N,N'-di-(4-methyl-3-isocyanatophenyl)-urea, mixed trimerization
products of diisocyanatotoluene and 1,6-diisocyanatohexamethylene,
1,6-diisocyanatohexane,
3,5,5-trimethyl-1-isocyano-3-isocyanatomethylcyclohexane
(isophorene diisocyanate), N,N',N''-tri-(6-isocyanatohexyl)-biuret,
2,2,4-trimethyl-1,6-diisocyanatohexane,
1-methyl-2,4-diisocyanatocyclohexane, diisocyanate,
4,4'-diisocyanatodicyclohexylmethane, trimeric isophorene,
diisocyanate, trimeric hexane diisocyanate and methyl
2,6-diisocyanatohexanoate.
[0058] As noted above, chain lengtheners may be used as well,
examples of which include diols and polyols, such as
1,4-butanediol, 1,1,1-trimethylolpropane or hydroquinone
2-hydroxyethyl ether, or diamines, such as diaminoethane,
1,6-diaminohexane, piperazine, 2,5-dimethylpiperazine,
1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane,
4,4'-diaminocyclohexylmethane, 1,4-diaminocyclohexane and
1,2-propylenediamine, or hydrazine, amino acid hydrazides,
hydrazides of semicarbazidocarboxylic acids, bis-hydrazides and
bis-semicarbazides.
[0059] A phenolic compound may then be reacted with the
isocyanate-functionalized prepolymer formed in the previous
reaction step.
[0060] Phenolic compounds suitable for use in this adduct building
reaction include any di- or poly-phenolic compound, though it is
desirable for the phenolic compound to be a bisphenol compound,
such as A, F, S or E, or a biphenol.
[0061] In general formula I, where terminal amine and/or hydroxy
groups are present, they may be reacted with carbonyl
biscaprolactam ("CBC") to produce the corresponding CBC-capped
adducts. (See e.g. general formula V.)
[0062] Such CBC-capped adducts may be used directly as tougheners
themselves in thermosetting resin formulations or they may be
further reacted with other functionalized polymers (such as those
polymers bearing one or more amine, hydroxyl, mercapto, epoxy or
episulfide groups) to form chain extended block copolymers via a
urethane or urea or thiourethane or oxazolidone linkage. These
so-formed chain extended block copolymers can thus also be used to
toughen thermosetting resin formulations. In addition, the use of
such chain extended block copolymers can assist in compatabilizing
otherwise incompatible adducts for use in thermosetting resin
formulations.
[0063] The inventive adducts can be readily prepared in a variety
of ways, which are discussed in the Examples section below.
[0064] Specific generalized structures of adducts within the scope
of the invention include:
##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023##
##STR00024##
[0065] In these generalized adduct structures, all applicable
designations are as used in connection with formula I.
[0066] As noted above, the thermosetting resin formulations embrace
epoxy, episulfide and/or benzoxazine. Representative epoxy monomers
contemplated for use herein the preparation of invention toughening
agents include bisphenol F diglycidyl ether, bisphenol A diglycidyl
ether, 4-vinyl-1-cyclohexene diepoxide, butanediol diglycidyl
ether, neopentylglycol diglycidyl ether,
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, limonene
diepoxide, hexanediol diglycidyl ether, trimethylolpropane
triglycidyl ether, aniline diglycidyl ether, diglycidyl ether of
propylene glycol, cyanuric acid triglycidyl ether, ortho-phthalic
acid diglycidyl ether, diglycidyl ester of linoleic dimer acid,
dicyclopentadiene diepoxide, diglycidyl ether of tetrachloro
bisphenol A, 1,1,1-tris(p-hydroxyphenyl)ethane glycidyl ether,
tetra glycidyl ether of tetrskis(4-hydroxyphenyl)ethane, epoxy
phenol novolac resins, epoxy cresol novolac resins,
tetraglycidyl-4,4'-diaminodiphenylmethane, and the like.
[0067] Among the commercially available epoxy resins suitable for
use herein are polyglycidyl derivatives of phenolic compounds, such
as those available under the tradenames EPON 828, EPON 1001, EPON
1009, and EPON 1031, from Shell Chemical Co.; DER 331, DER 332, DER
334, and DER 542 from Dow Chemical Co.; GY285 from Ciba Specialty
Chemicals, Tarrytown, N.Y.; and BREN-S from Nippon Kayaku, Japan.
Other suitable epoxy resins include polyepoxides prepared from
polyols and the like and polyglycidyl derivatives of
phenol-formaldehyde novolacs, the latter of which are available
commercially under the tradenames DEN 431, DEN 438, and DEN 439
from Dow Chemical Company. Cresol analogs are also available
commercially ECN 1235, ECN 1273, and ECN 1299 from Ciba Specialty
Chemicals. SU-8 is a bisphenol A-type epoxy novolac available from
Resolution. Polyglycidyl adducts of amines, aminoalcohols and
polycarboxylic acids are also useful in this invention,
commercially available resins of which include GLYAMINE 135,
GLYAMINE 125, and GLYAMINE 115 from F.I.C. Corporation; ARALDITE
MY-720, ARALDITE MY-721, ARALDITE 0500, and ARALDITE 0510 from Ciba
Specialty Chemicals and PGA-X and PGA-C from the Sherwin-Williams
Co. And of course combinations of the different epoxy resins are
also desirable for use herein.
[0068] Representative episulfide monomers for use herein are the
thiirane counterparts to the epoxy monomers noted in the preceding
paragraphs.
[0069] Representative benzoxazine monomers for use herein include
those embraced by the following structure:
##STR00025##
where o is 1-4, X is selected from a direct bond (when o is 2),
alkyl (when o is 1), alkylene (when o is 2-4), carbonyl (when o is
2), thiol (when o is 1), thioether (when o is 2), sulfoxide (when o
is 2), and sulfone (when o is 2), R.sub.1 is selected from
hydrogen, alkyl, alkenyl and aryl, and R.sub.4 is selected from
hydrogen, halogen, alkyl and alkenyl.
[0070] Alternatively, the benzoxazine may be embraced by the
following structure:
##STR00026##
where p is 2, Y is selected from biphenyl (when p is 2), diphenyl
methane (when p is 2), diphenyl isopropane (when p is 2), diphenyl
sulfide (when p is 2), diphenyl sulfoxide (when p is 2), diphenyl
sulfone (when p is 2), and diphenyl ketone (when p is 2), and
R.sub.4 is selected from hydrogen, halogen, alkyl and alkenyl.
[0071] More specifically, within structure BOZ-A the benzoxazine
may be embraced by the following structure BOZ-C:
##STR00027##
where X is selected from a direct bond, CH.sub.2,
C(CH.sub.3).sub.2, C.dbd.O, S, S.dbd.O and O.dbd.S.dbd.O, R.sub.1
and R.sub.2 are the same or different and are selected from
hydrogen, alkyl, such as methyl, ethyl, propyls and butyls,
alkenyl, such as allyl, and aryl and R.sub.4 are the same or
different and are selected from hydrogen or alkenyl, such as
allyl.
[0072] Representative benzoxazines within structure BOZ-C
include:
##STR00028##
where R.sub.1, R.sub.2 and R.sub.4 are as defined above.
[0073] Though not embraced by benzoxazine structures BOZ-A or
BOZ-B, additional benzoxazines are within the following
structures:
##STR00029##
where R.sub.1, R.sub.2 and R.sub.4 are as defined above, and
R.sub.3 is defined as R.sub.1, R.sub.2 or R.sub.4.
[0074] Specific examples of these benzoxazines include:
##STR00030## ##STR00031##
[0075] The benzoxazine component may include the combination of
multifunctional benzoxazines and monofunctional benzoxazines, or
may be the combination of one or more multifunctional benzoxazines
or one or more monofunctional benzoxazines.
[0076] Examples of monofunctional benzoxazines may be embraced by
the following structure:
##STR00032##
where R is alkyl, such as methyl, ethyl, propyls and butyls, or
aryl with or without substitution on one, some or all of the
available substitutable sites, and R.sub.4 is selected from
hydrogen, halogen, alkyl and alkenyl.
[0077] For instance, monofunctional benzoxazines may be embraced by
the structure
##STR00033##
where in this case R is selected from alkyl, alkenyl, each of which
being optionally substituted or interrupted by one or more O, N, S,
C.dbd.O, COO, and NHC.dbd.O, and aryl; m is 0-4; and
R.sub.1-R.sub.5 are independently selected from hydrogen, alkyl,
alkenyl, each of which being optionally substituted or interrupted
by one or more O, N, S, C.dbd.O, COOH, and NHC.dbd.O, and aryl.
[0078] Specific examples of such a monofunctional benzoxazine
are:
##STR00034##
where R is as defined above; or
##STR00035##
[0079] Many benzoxazines are presently available commercially from
several sources, including Huntsman Advanced Materials;
Georgia-Pacific Resins, Inc.; and Shikoku Chemicals Corporation,
Chiba, Japan, the last of which offers among others B-a, B-m, F-a,
C-a, Pd and F-a benzoxazine resins.
[0080] If desired, however, instead of using commercially available
sources, the benzoxazine may typically be prepared by reacting a
phenolic compound, such as a bisphenol A, bisphenol F, bisphenol S
or thiodiphenol, with an aldehyde and an alkyl or aryl amine. U.S.
Pat. No. 5,543,516, hereby expressly incorporated herein by
reference, describes a method of forming benzoxazines, where the
reaction time can vary from a few minutes to a few hours, depending
on reactant concentration, reactivity and temperature. See also
Burke et al., J. Org. Chem., 30 (10), 3423 (1965); see generally
U.S. Pat. Nos. 4,607,091 (Schreiber), 5,021,484 (Schreiber),
5,200,452 (Schreiber) and 5,443,911 (Schreiber).
[0081] The benzoxazine should be present in the inventive
composition in an amount in the range of about 10 to about 90
percent by weight, such as about 25 to about 75 percent by weight,
desirably about 35 to about 65 percent by weight, based on the
total weight of the composition.
[0082] Benzoxazine polymerization can be self-initiated under
elevated temperature conditions and also by inclusion of cationic
initiators, such as Lewis acids, and other known cationic
initiators, such as metal halides; organometallic derivatives;
metallophorphyrin compounds such as aluminum phthalocyanine
chloride; methyl tosylate, methyl triflate, and triflic acid; and
oxyhalides. Likewise, basic materials, such as imidizaoles, may be
used to initiate polymerization.
[0083] Typically, the composition including the inventive adduct
have about 40 to about 95 weight percent of the thermoset
component, about 5 to about 50 weight percent of the inventive
adduct, and about 0.2 to about 10 weight percent of the
curative.
[0084] As noted above, the composition may include as the thermoset
component any epoxy, episulfide or benzoxazine, at least a portion
of which is a multifunctional monomer. Ordinarily, the
multifunctional monomer used in the composition should be included
in amount within the range of about 20 weight percent to about 100
weight percent of the composition.
[0085] A monofunctional monomer, if present, should ordinarily be
used as a reactive diluent, or crosslink density modifier. In the
event such a monofunctional monomer is included as a portion of the
composition, such resin should be employed in an amount of up to
about 20 weight percent, based on the composition.
[0086] As employed herein, the term "curing agent" or "curative"
refers to polymerization promoters, co-curing agents, catalysts,
initiators or other additives designed to participate in or promote
curing of the adhesive formulation. With respect to epoxide-based
adhesive formulations, such curing agents include polymerization
promoters and catalysts such as, for example, anhydrides, amines,
imidazoles, amides, thiols, carboxylic acids, phenols,
dicyandiamide, urea, hydrazine, hydrazide, amino-formaldehyde
resins, melamine-formaldehyde resins, amine-boron trihalide
complexes, quaternary ammonium salts, quaternary phosphonium salts,
tri-aryl sulfonium salts, di-aryl iodonium salts, diazonium salts,
and the like, as well as combinations of any two or more thereof,
optionally also including a transition metal complex. Presently
preferred curing agents and catalysts for epoxy composition include
anhydrides, amines, imidazoles, and the like.
[0087] As readily recognized by those of skill in the art, curing
agents contemplated for use in the practice of the present
invention will vary with the reactive functionality(ies) present,
the presence of optional co-reactant(s), and the like. Typically,
the quantity of curing agent will fall in the range of about 1
weight percent up to about 50 weight percent of the composition,
with presently preferred amounts of curing agent falling in the
range of about 5 weight percent up to about 40 weight percent of
the composition.
[0088] Initiators contemplated for use with epoxide-based adhesive
formulations include hydroxy functionalized compounds such as, for
example, alkylene glycols. Preferred alkylene glycols include
ethylene glycols and propylene glycols.
[0089] Fillers contemplated for optional use in the practice of the
present invention include, for example, aluminum nitride, boron
nitride, silicon carbide, diamond, graphite, beryllium oxide,
magnesia, silicas, such as fumed silica or fused silica, alumina,
perfluorinated hydrocarbon polymers (i.e., TEFLON), thermoplastic
polymers, thermoplastic elastomers, mica, glass powder and the
like. Preferably, the particle size of these fillers will be about
20 microns. If aluminum nitride is used as a filler, it is
preferred that it be passivated via an adherent, conformal coating
(e.g., silica, or the like). Some of those fillers may impart
properties to the adhesive formulation such as, for example,
reduced thermal expansion of the cured adhesive, reduced dielectric
constant, improved toughness, increased hydrophobicity, and the
like.
[0090] Flexibilizers (also called plasticizers) contemplated for
optional use in the practice of the present invention include
branched polyalkanes or polysiloxanes that lower the T.sub.g of the
formulation. Such flexibilizers include, for example, polyethers,
polyesters, polythiols, polysulfides, and the like. If used,
flexibilizers typically are present in the range of about 0.5
weight percent up to about 30 weight percent of the
composition.
[0091] Dyes and/or pigments may be used in the practice of the
present invention. When present, such dyes and pigments are
typically present in the range of about 0.5 weight percent up to
about 5 weight percent based on the composition.
[0092] Rubber particles, especially rubber particles that have
relatively small average particle size (e.g., less than about 500
nm or less than about 200 nm), may also be included in the
compositions of the present invention. The rubber particles may or
may not have a shell common to known core-shell structures.
[0093] In the case of rubber particles having a core-shell
structure, such particles generally have a core comprised of a
polymeric material having elastomeric or rubbery properties (i.e.,
a glass transition temperature less than about 0.degree. C., e.g.,
less than about -30.degree. C.) surrounded by a shell comprised of
a non-elastomeric polymeric material (i.e., a thermoplastic or
thermoset/crosslinked polymer having a glass transition temperature
greater than ambient temperatures, e.g., greater than about
50.degree. C.). For example, the core may be comprised of a diene
homopolymer or copolymer (for example, a homopolymer of butadiene
or isoprene, a copolymer of butadiene or isoprene with one or more
ethylenically unsaturated monomers such as vinyl aromatic monomers,
(meth)acrylonitrile, (meth)acrylates, or the like) while the shell
may be comprised of a polymer or copolymer of one or more monomers
such as (meth)acrylates (e.g., methyl methacrylate), vinyl aromatic
monomers (e.g., styrene), vinyl cyanides (e.g., acrylonitrile),
unsaturated acids and anhydrides (e.g., acrylic acid),
(meth)acrylamides, and the like having a suitably high glass
transition temperature. Other rubbery polymers may also be suitably
be used for the core, including polybutylacrylate or polysiloxane
elastomer (e.g., polydimethylsiloxane, particularly crosslinked
polydimethylsiloxane).
[0094] The rubber particle may be comprised of more than two layers
(e.g., a central core of one rubbery material may be surrounded by
a second core of a different rubbery material or the rubbery core
may be surrounded by two shells of different composition or the
rubber particle may have the structure soft core, hard shell, soft
shell, hard shell). In one embodiment of the invention, the rubber
particles used are comprised of a core and at least two concentric
shells having different chemical compositions and/or properties.
Either the core or the shell or both the core and the shell may be
crosslinked (e.g., ionically or covalently). The shell may be
grafted onto the core. The polymer comprising the shell may bear
one or more different types of functional groups (e.g., epoxy
groups) that are capable of interacting with other components of
the compositions of the present invention.
[0095] Typically, the core will comprise from about 50 to about 95
weight percent of the rubber particles while the shell will
comprise from about 5 to about 50 weight percent of the rubber
particles.
[0096] Preferably, the rubber particles are relatively small in
size. For example, the average particle size may be from about 0.03
to about 2 microns or from about 0.05 to about 1 micron. The rubber
particles may have an average diameter of less than about 500 nm,
such as less than about 200 nm. For example, the core-shell rubber
particles may have an average diameter within the range of from
about 25 to about 200 nm.
[0097] Methods of preparing rubber particles having a core-shell
structure are well-known in the art and are described, for example,
in U.S. Pat. Nos. 4,419,496, 4,778,851, 5,981,659, 6,111,015,
6,147,142 and 6,180,693, each of which being incorporated herein by
reference in its entirety.
[0098] Rubber particles having a core-shell structure may be
prepared as a masterbatch where the rubber particles are dispersed
in one or more epoxy resins such as a diglycidyl ether of bisphenol
A. For example, the rubber particles typically are prepared as
aqueous dispersions or emulsions. Such dispersions or emulsions may
be combined with the desired epoxy resin or mixture of epoxy resins
and the water and other volatile substances removed by distillation
or the like. One method of preparing such masterbatches is
described in more detail in International Patent Publication No. WO
2004/108825, incorporated herein by reference in its entirety. For
example, an aqueous latex of rubber particles may be brought into
contact with an organic medium having partial solubility in water
and then with another organic medium having lower partial
solubility in water than the first organic medium to separate the
water and to provide a dispersion of the rubber particles in the
second organic medium. This dispersion may then be mixed with the
desired epoxy resin(s) and volatile substances removed by
distillation or the like to provide the masterbatch.
[0099] Particularly suitable dispersions of rubber particles having
a core-shell structure in an epoxy resin matrix are available from
Kaneka Corporation.
[0100] For instance, the core may be formed predominantly from feed
stocks of polybutadiene, polyacrylate, polybutadiene/acrylonitrile
mixture, polyols and/or polysiloxanes or any other monomers that
give a low glass transition temperature. The outer shells may be
formed predominantly from feed stocks of polymethylmethacrylate,
polystyrene or polyvinyl chloride or any other monomers that give a
higher glass transition temperature.
[0101] The core shell rubbers may have a particle size in the range
of 0.07 to 10 um, such as 0.1 to 5 um.
[0102] The core shell rubber made in this way are may be dispersed
in an epoxy matrix or a phenolic matrix. Examples of epoxy matrices
include the diglycidyl ethers of bisphenol A, F or S, or biphenol,
novalac epoxies, and cycloaliphatic epoxies. Examples of phenolic
resins include bisphenol-A based phenoxies.
[0103] The core shell rubber dispersion may be present in the epoxy
or phenolic matrix in an amount in the range of about 5 to about
50% by weight, with about 15 to about 25% by weight being desirable
based on viscosity considerations.
[0104] When used in the inventive compositions, these core shell
rubbers allow for toughening to occur in the composition and
oftentimes in a predictable manner--in terms of temperature
neutrality toward cure--because of the substantial uniform
dispersion, which is ordinarily observed in the core shell rubbers
as they are offered for sale commercially.
[0105] Many of the core-shell rubber structures available from
Kaneka are believed to have a core made from a copolymer of
(meth)acrylate-butadiene-styrene, where the butadiene is the
primary component in the phase separated particles, dispersed in
epoxy resins. Other commercially available masterbatches of
core-shell rubber particles dispersed in epoxy resins include
GENIOPERL M23A (a dispersion of 30 weight percent core-shell
particles in an aromatic epoxy resin based on bisphenol A
diglycidyl ether; the core-shell particles have an average diameter
of ca. 100 nm and contain a crosslinked silicone elastomer core
onto which an epoxy-functional acrylate copolymer has been
grafted); the silicone elastomer core represents about 65 weight
percent of the core-shell particle), available from Wacker Chemie
GmbH.
[0106] In the case of those rubber particles that do not have such
a shell, the rubber particles may be based on the core of such
structures.
[0107] Preferably, the rubber particles are relatively small in
size. For example, the average particle size may be from about 0.03
to about 2.mu. or from about 0.05 to about 1.mu.. In certain
embodiments of the invention, the rubber particles have an average
diameter of less than about 500 nm. In other embodiments, the
average particle size is less than about 200 nm. For example, the
rubber particles may have an average diameter within the range of
from about 25 to about 200 nm or from about 50 to about 150 nm.
[0108] The rubber particles generally are comprised of a polymeric
material having elastomeric or rubbery properties (i.e., a glass
transition temperature less than about 0.degree. C., e.g., less
than about -30.degree. C.). For example, the rubber particles may
be comprised of a diene homopolymer or copolymer (for example, a
homopolymer of butadiene or isoprene, a copolymer of butadiene or
isoprene with one or more ethylenically unsaturated monomers such
as vinyl aromatic monomers, (meth)acrylonitrile, (meth)acrylates,
or the like) and polysiloxanes. The rubber particles may contain
functional groups such as carboxylate groups, hydroxyl groups or
the like and may have a linear, branched, crosslinked, random
copolymer or block copolymer structure.
[0109] For instance, the rubber particles may be formed
predominantly from feed stocks of dienes such as butadiene,
(meth)acrylates, ethylenically unsaturated nitriles such as
acrylonitrile, and/or any other monomers that when polymerized or
copolymerized yield a polymer or copolymer having a low glass
transition temperature.
[0110] The rubber particles may be used in a dry form or may be
dispersed in a matrix, such as an epoxy matrix or a phenolic
matrix. The matrix material preferably is liquid at room
temperature. Examples of epoxy matrices include the diglycidyl
ethers of bisphenol A, F or S, or bisphenol, novalac epoxies, and
cycloaliphatic epoxies. Examples of phenolic resins include
bisphenol-A based phenoxies.
[0111] The rubber particles may be present in the epoxy or phenolic
matrix in an amount in the range of about 5 to about 50 weight
percent (about 15 to about 40 weight percent).
[0112] Typically, the composition may contain from about 5 to about
35 weight percent (in one embodiment, from about 15 to about 30
weight percent) rubber particles.
[0113] Combinations of different rubber particles may
advantageously be used in the present invention. The rubber
particles may differ, for example, in particle size, the glass
transition temperatures of their respective materials, whether, to
what extent and by what the materials are functionalized, and
whether and how their surfaces are treated.
[0114] A portion of the rubber particles may be supplied to the
adhesive composition in the form of a masterbatch wherein the
particles are stably dispersed in an epoxy resin matrix and another
portion may be supplied to the adhesive composition in the form of
a dry powder (i.e., without any epoxy resin or other matrix
material). For example, the adhesive composition may be prepared
using both a first type of rubber particles in dry powder form
having an average particle diameter of from about 0.1 to about
0.5.mu. and a second type of rubber particles stably dispersed in a
matrix of liquid bisphenol A diglycidyl ether at a concentration of
from about 5 to about 50 percent by weight having an average
particle diameter of from about 25 to about 200 nm. The weight
ratio of first type:second type rubber particles may be from about
1.5:1 to about 0.3:1, for example.
[0115] The chemical composition of the rubber particles may be
essentially uniform throughout each particle. However, the outer
surface of the particle may be modified by reaction with a coupling
agent, oxidizing agent or the like so as to enhance the ability to
disperse the rubber particles in the adhesive composition (e.g.,
reduce agglomeration of the rubber particles, reduce the tendency
of the rubber particles to settle out of the adhesive composition).
Modification of the rubber particle surface may also enhance the
adhesion of the epoxy resin matrix to the rubber particles when the
adhesive is cured. The rubber particles may alternatively be
irradiated so as to change the extent of crosslinking of the
polymer(s) constituting the rubber particles in different regions
of the particle. For example, the rubber particles may be treated
with gamma radiation such that the rubber is more highly
crosslinked near the surface of the particle than in the center of
the particle.
[0116] Rubber particles that are suitable for use in the present
invention are available from commercial sources. For example,
rubber particles supplied by Eliokem, Inc. may be used, such as NEP
R0401 and NEP R401S (both based on acrylonitrile/butadiene
copolymer); NEP R0501 (based on carboxylated
acrylonitrile/butadiene copolymer; CAS No. 9010-81-5); NEP R0601A
(based on hydroxy-terminated polydimethylsiloxane; CAS No.
70131-67-8); and NEP R0701 and NEP 0701S (based on
butadiene/styrene/2-vinylpyridine copolymer; CAS No.
25053-48-9).
[0117] Rubber particles that have been treated with a reactive gas
or other reagent to modify the outer surfaces of the particles by,
for instance, creating polar groups (e.g., hydroxyl groups,
carboxylic acid groups) on the particle surface, are also suitable
for use in the present invention. Illustrative reactive gases
include, for example, ozone, Cl.sub.2, F.sub.2, O.sub.2, SO.sub.3,
and oxidative gases. Methods of surface modifying rubber particles
using such reagents are known in the art and are described, for
example, in U.S. Pat. Nos. 5,382,635; 5,506,283; 5,693,714; and
5,969,053, each of which is incorporated herein by reference in its
entirety. Suitable surface modified rubber particles are also
available from commercial sources, such as the rubbers sold under
the tradename VISTAMER by Exousia Corporation.
[0118] Where the rubber particles are initially provided in dry
form, it may be advantageous to ensure that such particles are well
dispersed in the adhesive composition prior to curing the adhesive
composition. That is, agglomerates of the rubber particles are
preferably broken up so as to provide discrete individual rubber
particles, which may be accomplished by intimate and thorough
mixing of the dry rubber particles with other components of the
adhesive composition. For example, dry rubber particles may be
blended with epoxy resin and milled or melt compounded for a length
of time effective to essentially completely disperse the rubber
particles and break up any agglomerations of the rubber
particles.
[0119] Conditions suitable to cure the inventive compositions
include exposing the compositions to a temperature of at least
about 120.degree. C. but less than about 190.degree. C. for about
0.5 up to about 60 minutes, such as 30 minutes at 180.degree.
C.
[0120] More specifically, the inventive adducts may be used as
latent curatives for the thermoset, if they contain a thiol and/or
amine functional group or if they are reacted to become
functionalized with such a group. In addition, they may be used to
prepare compositions capable of curing at temperatures lower than
those set forth above, such as at about 100.degree. C.
[0121] The inventive compositions may also be formulated as one
part compositions or two part compositions, as desired. In a one
part composition, it may be desirable to grind the inventive adduct
to a uniform particle size, such as by cryogenic grinding
techniques, to ensure a dispensable particle size. In a two part
composition, the inventive adduct may be solubilized in one of the
parts.
[0122] Adducts E, G, K, N, T and V are already functionalized with
amine groups and thus may be used as is without further reaction,
for instance. Adduct Q, being functionalized with isocyanates, need
only react with an amino alcohol or a hydroxyl thiol, for instance,
to functionalize Adduct Q with an amine or thiol, respectively (see
below Adduct QA). Adduct B, being hydroxyl functionalized, is first
reacted with isocyanate (such as any of those disclosed herein) and
then with an amino alcohol or a hydroxyl thiol, for instance, to
functionalize Adduct B with an amine or thiol, respectively (see
below Adduct BA).
##STR00036## [0123] BA
[0124] The present invention provides methods for adhesively
attaching a first article to a second article. Such methods
include
[0125] (a) applying an inventive composition to a first
article,
[0126] (b) bringing together the first article and a second article
into intimate contact to form an assembly, where the first article
and the second article are separated only by the adhesive
composition applied in step (a), and thereafter,
[0127] (c) subjecting the assembly to conditions suitable to cure
the composition.
[0128] In accordance with yet another embodiment of the present
invention, there are provided assemblies produced by these
methods.
[0129] The invention will now be illustrated by way of the
following examples.
EXAMPLES
Example 1
General Preparation of Polyurethane Type Adducts
[0130] One equivalent of a functionalized polyether or polydimethyl
siloxane backbone material (such as one terminated at each end with
one of hydroxyl, amino, mercapto or carboxyl) is reacted with 2
equivalents of a diisocyanate (e.g., hexamethylene diisocyanate or
isophorone diisocyanate) by bringing into contact the two materials
with or without the presence of a chain extender such as
trimethylol propane, under appropriate catalysis at a temperature
between 20 and 100.degree. C., particularly between 60-80.degree.
C., under an inert atmosphere. The reaction is maintained until the
isocyanate content indicates a value which indicates complete
reaction. The materials may be used individually or in blends in
this reaction.
[0131] The above intermediate isocyanate terminated adduct is then
capped by reaction of the terminal isocyanate functional groups
with the required capping agent, such as a phenol (e.g.,
2,2'-diallyl bisphenol A or resorcinol), a diamine (e.g., JEFFAMINE
D-2000 or HYCAR 1300X21) or an epoxy (e.g., the blend of EPON
82B/EPON 1001).
[0132] In this manner Adducts A1-2, C1-6, R1-4, S, T, W, Z, AB and
AC may be synthesised.
[0133] In the case of Adducts D1-D8 an isocyanate-free synthesis
route is employed whereby a diamino terminated PDMS material is
reacted with 2 equivalents of a CBC-blocked JEFFAMINE to afford the
corresponding CBC-terminated adduct. This is then capped by
reaction of the terminal CBC groups with an appropriate phenolic
capping agent.
Example 2
Preparation of an A-B-A Block Copolymer Type Adduct
[0134] Here, one equivalent of a functionalized polyether or
polydimethyl siloxane backbone material (such as one terminated at
each end with one of hydroxyl, anhydride, (meth)acrylate, or amine)
as a Block B is reacted with an appropriate amount (2 equivalents
for example) of a Block A material such as: [0135] Reaction of
amino/mercapto/hydroxy terminated Block B material with a lactone
such as caprolactone [Adducts B1-4], [0136] Reaction of an amine-
or mercapto-containing material by Michael addition reaction of one
or more equivalents of a JEFFAMINE onto an acrylate [Adducts K1-10]
or methacrylate [Adducts N1-9] terminated Block B material, or
reaction of an amine- or mercapto-terminated Block B material by
Michael addition reaction onto a (meth)acrylate-terminated Block A
segment [Adduct Y], or [0137] Reaction of an anhydride terminated
Block B material with one or more equivalents of an
amine/mercapto/hydroxy terminated Block A material [Adduct E]
[0138] The Block A and B materials in proper stoichiometric amounts
are heated to an appropriate temperature for a period of time of
1-24 hours, depending on the nature and identity of the reactants,
to form the an A-B-A block copolymer type adduct.
Example 3
Capping of Amine Terminated Adducts with Epoxy Groups
[0139] This reaction was carried out generally according to U.S.
Pat. No. 5,084,532. Thus, a blend of EPON 828 and EPON 1001 in
appropriate molar ratios was placed into a reaction vessel and
heated with mechanical stirring at a temperature of 110.degree. C.
for a period of time sufficient to create a flowable melted epoxy
blend. JEFFAMINE T-403 was then added dropwise and the reaction
allowed to stir for a period of time of 1 hour at a temperature of
110.degree. C. An appropriate amine terminated adduct was then
added dropwise to this reaction mixture, and the reaction was
stirred for a further 1 hour period of time at the same
temperature, and then allowed to cool to room temperature.
[0140] Adducts F, H, M1-10, P1-9, and W were prepared according to
this procedure.
Example 4
Capping of Amine Terminated Adducts with CBC
[0141] This reaction was carried out generally with reference to
Angew. Chem. Int. Ed., 42, 5094-5097 (2003).
[0142] An amine terminated adduct and an appropriate required
amount of carbonyl biscaprolactam are placed into a reaction
vessel, heated with stirring to a temperature of 100-150.degree. C.
for a period of time of between 1-24 hours and then allowed to
cool.
[0143] Adducts I, J, L1-9, O1-7, U1, X, AD1-3 and AE were prepared
according to this procedure.
Example 5
[0144] An adduct exhibiting good low temperature wedge impact
toughening properties was prepared by a Michael addition reaction
of JEFFAMINE D-2000 onto the methacrylate double bond of a
(meth)acrylate-terminated polydimethyl siloxane, DMS R11. The
initial amine-terminated Michael adduct (Adducts K1-10, N1-9) was
then capped by reaction with carbonyl biscaprolactam (Adducts L1-9,
O1-7) or epoxy (Adducts P1-9, M1-10) as depicted in the following
scheme and as described in Examples 3 and 4 previously:
##STR00037##
[0145] More specifically, in a clean, dry round bottom flask
JEFFAMINE D-2000 (80 g, 0.04 mol) was heated to a temperature of
170.degree. C. and (meth)acrylate terminated PDMS, DMS R11 (21 g,
0.02 mol) was added dropwise with stirring. On complete addition of
the DMS R11, the reaction was stirred for a further period of 90
minutes before cooling to room temperature. The initial adduct
(Adduct N7) was obtained as a yellow, silk-like low viscosity
resin.
[0146] To cap with CBC, the resin obtained above (37.88 g, 0.0075
mol) was mixed with carbonyl biscaprolactam (3.78 g, 0.015 mol),
deaerated under vacuum, flushed with inert gas and heated at a
temperature of 100.degree. C. for a period of time of 90 minutes.
The reaction was allowed to cool to room temperature to afford a
yellow, gel-like/semi-solid resin (Adduct O7).
[0147] Alternatively, to cap with epoxy, a reaction was carried out
generally in accordance with U.S. Pat. No. 5,084,532 (Schenkel),
such as in Example 1 thereof.
[0148] To cap with phenol instead, a reaction was carried out as
described below in the following paragraph, which describes a
one-pot synthesis.
Synthesis of Adduct AC with 4:1 Ratio of PPG to PDMS
[0149] In a clean, dry round bottom flask equipped with a
mechanical overhead stirrer, nitrogen inlet, thermometer and a
pressure equalising dropping funnel was charged PPG 2000 (120 g,
0.06 mol), silanol DMS C16 (10.875 g, 0.015 mol), trimethylol
propane (0.76 g, 0.0056 mol) and hexamethylene diisocyanate (22.96
g, 0.136 mol). Dibutyl tin dilaurate was added as a catalyst and
the solution stirred under an inert atmosphere and the temperature
raised to 60.degree. C. at which point reaction is observed to
start with the formation of bubbles and an increase in temperature
to 80.degree. C.-120.degree. C. The contents were stirred at a
temperature of 80-120.degree. C. for a period of time of 90 minutes
and then cooled to a temperature of 80-90.degree. C. 2,2'-diallyl
bisphenol A was added with stirring continued for a further period
of time of 90 minutes, with the final 30 minutes of stirring being
performed under reduced pressure to remove volatiles, and then
cooled to room temperature. The so-formed adduct is believed to
have a structure similar to that shown below:
##STR00038##
Example 6
[0150] Table 1 represents a set of model formulations prepared with
different adducts.
TABLE-US-00003 TABLE 1 Sample Nos./Amt (wt %) Component A Type
Identity I II III IV V B Epoxy EPON 828 65 60 50 40 30 45 Toughener
Adduct 5 10 20 30 20 20 POLYDIS 3614* 20 20 20 20 40 --
Epoxy-Jeffamine Adduct** -- -- -- -- -- 20 CARDOLITE 2513*** 4 4 4
4 4 4 Silica Filler AEROSIL R202 4 4 4 4 4 4 Curative DICY 4 4 4 4
4 4 FENURON 0.15 0.15 0.15 0.15 0.15 0.15 *Nitrile rubber modified
epoxy prepolymer based on DGEBPA, available commercially from
Struktol Company of America, Stow, OH **Prepared generally in
accordance with U.S. Pat. No. 5,084,532 (Schenkel), such as in
Example 1 thereof ***Reactive diluent
[0151] Tables 1A-1E show a list of raw material components used to
prepare many of the adducts referred to herein, and presented in
the examples which follow.
TABLE-US-00004 TABLE 1A Adduct Raw Material A1 PPG 2000, HMDI, TMP,
2,2'-DABPA A2 PolyTHF 2000, IPDI, TMP, 2,2'-DABPA B1 DMS C15,
Caprolactone n = 16 B2 DMS C15, Caprolactone n = 24 B3 DMS C21,
Caprolactone n = 16 B4 DMS C21, Caprolactone n = 24 C1 B1 +
hexamethylene diisocyanate + 2,2'-diallylbisphenol A C2 B2 +
hexamethylene diisocyanate + 2,2'-diallylbisphenol A C3 B3 +
hexamethylene diisocyanate + 2,2'-diallylbisphenol A C4 B4 +
hexamethylene diisocyanate + 2,2'-diallylbisphenol A C5 SB 800 +
hexamethylene diisocyanate + 2,2'-diallylbisphenol A C6 SB 801 +
hexamethylene diisocyanate + 2,2'-diallylbisphenol A
TABLE-US-00005 TABLE 1B Adduct Raw Material D1 CBC Capped JEFFAMINE
D-400/PDMS 1218/resorcinol D2 CBC Capped JEFFAMINE D-400/PDMS
1218/2-allyl phenol D3 CBC Capped JEFFAMINE D-400/PDMS
3345/resorcinol D4 CBC Capped JEFFAMINE D-400/PDMS 3345/2-allyl
phenol D5 CBC Capped JEFFAMINE D-2000/PDMS 1218/resorcinol D6 CBC
Capped JEFFAMINE D-2000/PDMS 1218/2-allyl phenol D7 CBC Capped
JEFFAMINE D-2000/PDMS 3345/resorcinol D8 CBC Capped JEFFAMINE
D-2000/PDMS 3345/2-allyl phenol E DMS Z21/JEFFAMINE D-2000 F E +
EPON 828/EPON 1001 G E @ 150.degree. C. H G/EPON 828/EPON 1001 I E
+ Carbonyl biscaprolactam J G + Carbonyl biscaprolactam K1
JEFFAMINE D-2000 + DMS-U22 K2 JEFFAMINE D-2000 + DBE-U12 K3
JEFFAMINE D-400 + DBE-U12 K4 JEFFAMINE D-2000 + TEGOMERV-Si 2250 K5
JEFFAMINE D-400 + TEGOMER V-Si 2250 K6 JEFFAMINE D-2000 + DMS U22
K7 JEFFAMINE D-4000 + DBE U12 K8 JEFFAMINE D-4000 + TEGOMER V-Si
2250 K9 JEFFAMINE T-5000 + DBE U12 (2:1) K10 JEFFAMINE T-5000 + DBE
U12 (1:1)
TABLE-US-00006 TABLE 1C Adduct Raw Material L1 K1 + CBC L2 K2 + CBC
L3 K3 + CBC L4 K4 + CBC L5 JEFFAMINE D-4000 + DBE U12 + CBC L6
JEFFAMINE D-4000 + DMS U22 + CBC L7 JEFFAMINE D-4000 + TEGOMER V-Si
2250 + CBC L8 K9 + CBC L9 K10 + CBC M1 K1 + EPON 828/EPON 1001 M2
K2 + EPON 828/EPON 1001 M3 K3 + EPON 828/EPON 1001 M4 K9 + EPON
828/EPON 1001 M5 K4 + EPON 828/EPON 1001 M6 K5 + EPON 828/EPON 1001
M7 DMS U22 + JEFFAMINE D-4000 + EPON 828/EPON 1001 M8 K7 + EPON
828/EPON 1001 M9 K8 + EPON 828/EPON 1001 M10 K10 + EPON 828/EPON
1001 N1 SLM 446016-15 VP + JEFFAMINE D-2000 N2 SLM 446016-15 VP +
JEFFAMINE D-400 N3 SLM 446016-15 VP + JEFFAMINE D-4000 N4 SLM
446016-50 VP + JEFFAMINE D-2000 N5 SLM 446016-50 VP + JEFFAMINE
D-400 N6 SLM 446016-50 VP + JEFFAMINE D-4000 N7 DMS-R11 + JEFFAMINE
D-2000 N8 DMS-R11 + JEFFAMINE D-400 N9 DMS-R11 + JEFFAMINE
D-4000
TABLE-US-00007 TABLE 1D Adduct Raw Material O1 N1 + CBC O2 N3 + CBC
O3 N9 + CBC O4 N4 + CBC O5 N5 + CBC O6 N6 + CBC O7 N7 + CBC P1 N1 +
EPON 828/EPON 1001 P2 N2 + EPON 828/EPON 1001 P3 N3 + EPON 828/EPON
1001 P4 N4 + EPON 828/EPON 1001 P5 N5 + EPON 828/EPON 1001 P6 N6 +
EPON 828/EPON 1001 P7 N7 + EPON 828/EPON 1001 P8 N8 + EPON 828/EPON
1001 P9 N9 + EPON 828/EPON 1001 R1 DMS-C15 + HMDI + 2,2'-DABPA R2
DMS-C15 + HMDI + Resorcinol R3 DMS-C15 + MDI + 2,2'-DABPA R4
DMS-C15 + MDI + Resorcinol S TEGOMER C-Si 2342 + HMDI + EPON
828/1001 T TEGOMER H-Si 2311, HMDI, JEFFAMINE D-2000 U1 T + CBC U2
T + EPON 828/1001 V TEGOMER C-Si 2342 + HMDI + HYCAR 1300X21 W V +
EPON 828/1001 X V + CBC Y VTBN 1300X43 + PDMS 1218
TABLE-US-00008 TABLE 1E Adduct Raw Material Z TEGOMER H-Si 2311 +
HMDI + EPON 828/1001 AA Poly-THF-block-poly-CPL + DMS-C21 +
3-glycidoxypropyl trimethoxy silane AB LP3 + TMP + HMDI +
2,2'-DABPA AC PPG 2000 + DMS C15 + TMP + HMDI + 2,2'-DABPA AD1
JEFFAMINE D-2000 + DMS-A12 (10 mol. %) + CBC AD2 JEFFAMINE D-2000 +
DMS-A12 (20 mol. %) + CBC AD3 JEFFAMINE D-2000 + DMS-A12 (50 mol.
%) + CBC AE JEFFAMINE D-2000 + CBC
[0152] The following legend is useful in connection with Tables
1A-1E above.
PPG 2000=Polypropylene glycol (mol. wt. 2000) TMP=Trimethylol
propane 2,2'-DABPA=2,2'-Diallyl bisphenol A Poly THF
2000=polytetrahydrofuran (mol. wt. 2000) IPDI=Isophorone
diisocyanate DMAP=N,N'-dimethylaminopyridine MDI=HMDI=Hexamethylene
diisocyanate HYCAR 1300X21=amine terminated butadiene-acrylonitrile
resin VTBN 1300X43=vinyl terminated butadiene-acrylonitrile resin
PolyTHF-block-poly-CPL=polytetrahydrofuran-poly-caprolactone block
co-polymer LP3=Liquid polysulphide resin
Silane/Silicone Materials:
From Gelest:
[0153] DMS-A12=Bis-(3-aminopropyl) terminated PDMS (mol. wt.
900-1000) DMS-C15=Hydroxy ethylene oxide propyl terminated PDMS
(mol. wt. 1000) DMS-C21=Hydroxy ethylene oxide propyl terminated
PDMS (mol. wt. 4500-5500) DMS-R11=Methacryloxypropyl terminated
PDMS (mol. wt. 900-1200) DMS-U22=(3-Acryloxy-2-hydroxypropyl)
terminated PDMS (mol. wt. 1000-1200) DBE-U12=Acryloxy terminated
ethylene oxide dimethylsiloxane-ethylene oxide ABA block copolymer
(mol. wt. 1500-1600) DMS-Z21=Succinic anhydride terminated PDMS
(mol. wt. 600-800) PDMS 1218=Bis-(3-aminopropyl) terminated PDMS
(mol. wt. .about.1200)
From Wacker Silicones:
[0154] PDMS 1218=Bis-(3-aminopropyl) terminated PDMS (mol. wt.
.about.1200) PDMS 3345=Bis-(3-aminopropyl) terminated PDMS (mol.
wt. .about.3350) SLM 446016-15 VP=Bis-(methacryloxy)methyl
terminated PDMS (mol. wt. .about.1,330) SLM 446016-50
VP=Bis-(methacryloxy)methyl terminated PDMS (mol. wt. .about.3,880)
SLM 446200-350 #SB 800=Hydroxy terminated PDMS-co-polycaprolactone
copolymer (mol. wt. .about.5800) SLM 446200-350 #SB 801=Hydroxy
terminated PDMS-co-polycaprolactone copolymer (mol. wt.
.about.9030)
From Tego Chemie:
[0155] TEGOMER V--Si 2250=Linear acryloxy terminated
organo-functional PDMS (mol. wt. .about.2500). TEGOMER C--Si
2342=Linear carboxyl terminated organo-functional PDMS (mol. wt.
.about.2800). TEGOMER H--Si 2311=Linear hydroxy terminated
organo-functional PDMS (mol. wt. .about.2500).
[0156] The results of the formulation evaluations are set forth
below in each of Tables 2-14.
[0157] In Tables 2-14, Adducts AC, V, H, U1, U2, N1, M2, M3, M4,
M5, N, O1, O2, and O3, respectively, have been evaluated on grit
blasted mild steel impact peel test coupons of a 0.8 mm thickness
in accordance with ISO 11343, using a bondline thickness of 0.25 mm
for wedge impact performance at least one of room temperature,
-20.degree. C. and -40.degree. C., for dynamic resistance and
impact energy.
TABLE-US-00009 TABLE 2 Sample Nos. A Wedge Impact @ AC-I AC-II
AC-III AC-IV AC-V B Room Dynamic Resistance -- -- 17.67 28.85 18.69
23.11 Temperature (N/mm) -20.degree. C. -- -- 7.29 17.13 7.52 18.68
-40.degree. C. -- -- -- 2.75 -- 2.14 Room Impact Energy -- -- 5.87
9.57 5.94 7.66 Temperature (Joules) -20.degree. C. -- -- 1.91 4.89
1.91 5.67 -40.degree. C. -- -- -- 0.63 -- 0.49
TABLE-US-00010 TABLE 3 Sample Nos. A Wedge Impact @ U1-I U1-II
U1-III U1-IV U1-V B Room Dynamic -- -- -- 7.78 -- -- Temperature
Resistance -20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C.
-- -- -- -- -- -- Room Impact -- -- -- 2.01 -- -- Temperature
Energy -20.degree. C. (Joules) -- -- -- -- -- -- -40.degree. C. --
-- -- -- -- --
TABLE-US-00011 TABLE 4 Sample Nos. A Wedge Impact @ H-I H-II H-III
H-IV H-V B Room Dynamic -- -- 1.60 -- -- -- Temperature Resistance
-20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C. -- -- -- --
-- -- Room Impact Energy -- -- 0.39 -- -- -- Temperature (Joules)
-20.degree. C. -- -- -- -- -- -- -40.degree. C. -- -- -- -- --
--
TABLE-US-00012 TABLE 5 Sample Nos. A Wedge Impact @ U2-I U2-II
U2-III U2-IV U2-V B Room Dynamic -- -- -- 6.82 -- -- Temperature
Resistance -20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C.
-- -- -- -- -- -- Room Impact -- -- -- 1.90 -- -- Temperature
Energy -20.degree. C. (Joules) -- -- -- -- -- -- -40.degree. C. --
-- -- -- -- --
TABLE-US-00013 TABLE 6 Sample Nos. A M1- Wedge Impact @ M1-I M1-II
III M1-IV M1-V B Room Dynamic 9.46 8.43 17.55 21.52 27.85 11.94
Temperature Resistance -20.degree. C. (N/mm) -- -- -- -- -- --
-40.degree. C. -- -- -- -- -- -- Room Impact 2.40 2.10 5.27 6.51
8.81 3.36 Temperature Energy -20.degree. C. (Joules) -- -- -- -- --
-- -40.degree. C. -- -- -- -- -- --
TABLE-US-00014 TABLE 7 Sample Nos. A M2- Wedge Impact @ M2-I M2-II
M2-III M2-IV V B Room Dynamic -- -- 9.81 17.49 17.65 3.16
Temperature Resistance -20.degree. C. (N/mm) -- -- 3.62 3.62 -- --
-40.degree. C. -- -- -- -- -- -- Room Impact -- -- 2.65 5.14 5.17
0.82 Temperature Energy -20.degree. C. (Joules) -- -- 0.82 0.82 --
-- -40.degree. C. -- -- -- -- -- --
TABLE-US-00015 TABLE 8 Sample Nos. A Wedge Impact @ M8-I M8-II
M8-III M8-IV M8-V B Room Dynamic -- -- -- -- 4.76 -- Temperature
Resistance -20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C.
-- -- -- -- -- -- Room Impact -- -- -- -- 1.24 -- Temperature
Energy -20.degree. C. (Joules) -- -- -- -- -- -- -40.degree. C. --
-- -- -- -- --
TABLE-US-00016 TABLE 9 Sample Nos. A Wedge Impact @ M4-I M4-II
M4-III M4-IV M4-V B Room Dynamic -- -- -- 12.13 -- -- Temperature
Resistance -20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C.
-- -- -- -- -- -- Room Impact -- -- -- 3.27 -- -- Temperature
Energy -20.degree. C. (Joules) -- -- -- -- -- -- -40.degree. C. --
-- -- -- -- --
TABLE-US-00017 TABLE 10 Sample Nos. A M5- Wedge Impact @ M5-I M5-II
M5-III IV M5-V B Room Dynamic 0 5.03 18.81 15.19 19.14 14.84
Temperature Resistance -20.degree. C. (N/mm) -- -- 00 -- 3.21 --
-40.degree. C. -- -- -- -- -- -- Room Impact 0 1.37 5.77 4.58 6.14
4.13 Temperature Energy -20.degree. C. (Joules) -- -- 00 -- 0.81 --
-40.degree. C. -- -- -- -- -- --
[0158] The 00 indicates that the bonds created were evaluated but
could be pulled apart manually, i.e., they had zero or 0.00
strength.
TABLE-US-00018 TABLE 11 Sample Nos. A Wedge Impact @ N6-I N6-II
N6-III N6-IV N6-V B Room Dynamic -- -- -- 7.77 -- -- Temperature
Resistance -20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C.
-- -- -- -- -- -- Room Impact -- -- -- 1.74 -- -- Temperature
Energy -20.degree. C. (Joules) -- -- -- -- -- -- -40.degree. C. --
-- -- -- -- --
TABLE-US-00019 TABLE 12 Sample Nos. A Wedge Impact @ O1-I O1-II
O1-III O1-IV O1-V B Room Dynamic -- 4.50 10.40 8.74 -- --
Temperature Resistance -20.degree. C. (N/mm) -- -- -- -- -- --
-40.degree. C. -- -- -- -- -- -- Room Impact -- 1.10 2.69 2.30 --
-- Temperature Energy -20.degree. C. (Joules) -- -- -- -- -- --
-40.degree. C. -- -- -- -- -- --
TABLE-US-00020 TABLE 13 Sample Nos. A Wedge Impact @ O7-I O7-II
O7-III O7-IV O7-V B Room Dynamic -- -- 17.38 21.52 17.53 20.53
Temperature Resistance -20.degree. C. (N/mm) -- -- 00 5.22 00 7.88
-40.degree. C. -- -- -- -- 00 1.05 Room Impact -- -- 5.49 7.01 5.47
6.81 Temperature Energy -20.degree. C. (Joules) -- -- 00 1.21 00
2.00 -40.degree. C. -- -- -- -- 00 0.22
TABLE-US-00021 TABLE 14 Sample Nos. A Wedge Impact @ O3-I O3-II
O3-III O3-IV O3-V B Room Dynamic -- -- -- 7.34 -- -- Temperature
Resistance -20.degree. C. (N/mm) -- -- -- -- -- -- -40.degree. C.
-- -- -- -- -- -- Room Impact -- -- -- 1.73 -- -- Temperature
Energy -20.degree. C. (Joules) -- -- -- -- -- -- -40.degree. C. --
-- -- -- -- --
Example 7
[0159] Adduct AE-1 was used to formulate epoxy compositions in the
amount noted below in Table 15.
TABLE-US-00022 TABLE 15 Composition Sample No./Amt. (wt %) Type
Identity 100 101 102 103 104 Epoxy EPON 828 80 70 60 50 40 Adduct
Adduct AE-1 -- 10 20 30 40 Epoxy CARDOLITE 2513 4 4 4 4 4 Diluent
Silica AEROSIL R202 2 2 2 2 2 Filler Curative DICY 4 4 4 4 4
FENURON 0.15 0.15 0.15 0.15 0.15
[0160] Sample No. 100 is a control and was used for comparative
purposes.
[0161] Each of Sample Nos. 100-104 were then cured for a period of
time of 30 minutes at a temperature of 180.degree. C. and evaluated
for tensile shear strength and peel strength, the results of which
are reported below in Table 16.
TABLE-US-00023 TABLE 16 Physical Property Tensile Shear Strength
Tensile Peel Strength Sample No. (N/mm.sup.2) (N/mm) 100 22.52
1.681 101 36.43 3.42 102 32.52 8.257 103 23.09 9.282 104 13.33
7.93
[0162] Sample No. 100 shows poor T-peel strength, whereas
progressively increasing the level of Adduct AE in the
compositions, such as to a level of 20-30 weight percent in Sample
Nos. 102-103, increases both the tensile shear and T-peel strength,
illustrating the usefulness of this adduct for toughening
purposes.
[0163] Adduct AE was also used to formulate epoxy compositions
with, and for comparison with, other toughening agents, as shown
below in Table 17.
TABLE-US-00024 TABLE 17 Composite Sample No. Amt. (wt. %) Type
Identity 105 106 107 108 109 Epoxy EPON 828 10 10 30 30 30
Toughener Adduct AE -- 30 30 30 30 KANEKA MX 120* 50 50 -- -- --
POLYDIS 3614 -- -- -- 30 -- Epoxy-JEFFAMINE 30 -- 30 -- -- Adduct**
Dow Adduct*** -- -- -- -- 30 Reactive CARDOLITE 2513 4 4 4 4 4
Diluent Silica Filler AEROSIL R202 2 2 2 2 2 Curative DICY 4 4 4 4
4 FENURON 0.15 0.15 0.15 0.15 0.15 *masterbatch of 25 weight %
nano-sized core-shell rubber in a matrix of bisphenol A diglycidyl
ether epoxy resin, available commercially from Kaneka Corporation
**Prepared in accordance with U.S. Pat. No. 5,084,532 (Schenkel)
***Prepared in accordance with Examples 16-20 of U.S. Pat. No.
5,278,257 (Mulhaupt)
[0164] Sample No. 105 is a control and was used for comparative
purposes.
[0165] Each of Sample Nos. 105-109 was evaluated for tensile shear
strength and peel strength, the results of which are reported below
in Table 18.
TABLE-US-00025 TABLE 18 Physical Property Sample No. Tensile Shear
(N/mm.sup.2) Tensile Peel (N/mm) 105 38.4 12.154 106 21.3 10.889
107 16.5 11.498 108 15.2 9.851 109 6.2 8.003
[0166] The results in Table 18 demonstrate the utility of Adduct AE
as a co-toughener with the listed and evaluated tougheners. More
specifically, when used in conjunction with either KANEKA MX 120
core shell rubber or the epoxy-JEFFAMINE adduct excellent T-peel
strength values are attained compared to the control, although the
tensile shear values appear to be negatively impacted.
Example 8
[0167] Blends of JEFFAMINE D2000 and 10%, 20% and 50% molar
equivalents of DMS A12 (aminopropyl terminated PDMS, mol. wt.
800-1100) were each reacted with an appropriate amount of CBC to
afford a resinous product consisting of a mixture of CBC blocked
JEFFAMINE D2000 with 10%, 20% and 50% of CBC blocked PDMS as
follows:
##STR00039##
The resulting adduct is referred to as Adduct AD.
[0168] Tables 19A and 19B provide formulation information of
samples prepared with CBC blocked JEFFAMINE and Adduct AD.
TABLE-US-00026 TABLE 19A Constituent Sample Nos./Amt. (wt %) Type
Identity 110 111 112 113 114 115 116 Epoxy EPON 828 60 80 70 60 50
80 70 Toughener CBC Blocked 30 -- -- -- -- -- -- JEFFAMINE Adduct
AD-1 -- 10 20 30 40 -- -- Adduct AD-2 -- -- -- -- -- 10 20 Adduct
AD-3 -- -- -- -- -- -- -- Reactive Diluent CARDOLITE 2513 4 4 4 4 4
4 4 Silica AEROSIL 2 2 2 2 2 2 2 Filler R202 Curative DICY 4 4 4 4
4 4 4 FENURON 0.15 0.15 0.15 0.15 0.15 0.15 0.15
TABLE-US-00027 TABLE 19B Constituent Sample Nos./Amt. (wt %) Type
Identity 117 118 119 120 121 122 Epoxy EPON 828 60 50 80 70 60 50
Toughener CBC Blocked -- -- -- -- -- -- JEFFAMINE Adduct AD-1 -- --
-- -- -- -- Adduct AD-2 30 40 -- -- -- -- Adduct AD-3 -- -- 10 20
30 40 Reactive CARDOLITE 4 4 4 4 4 4 Diluent 2513 Silica AEROSIL 2
2 2 2 2 2 Filler R202 Curative DICY 4 4 4 4 4 4 FENURON 0.15 0.15
0.15 0.15 0.15 0.15
[0169] Sample No. 110 is a control and is used for comparative
purposes. Table 20 below provides T peel and tensile shear strength
performance with Adducts AD-1, 2 and 3 in epoxy formulations,
demonstrating the ability of those adducts to toughen such
formulations.
TABLE-US-00028 TABLE 20 Physical Sample Nos. Property 110 111 112
113 114 115 116 117 118 119 120 121 122 T-Peel 8.12 0.7 8.2 9.6 9.7
1.0 1.9 6.1 8.5 2.1 5.9 6.0 3.5 (N/mm) Tensile -- 6 2 8 0 1 4 0 6 1
3 1 6 Shear (N/mm.sup.2) GBMS 30 mins. @ 180.degree. C.
[0170] The T peel and tensile shear strength evaluations were
performed in accordance with the following respective
parameters:
TABLE-US-00029 180.degree. Tensile Peel ASTM D1876 Specimens: Grit
Blasted Mild Steel (GBMS), 1.00 mm substrate thickness Bondline:
0.25 mm Testing rate: 200 mm/min Test temperature: Ambient, 0, -10,
-20, -30, -40.degree. C.
TABLE-US-00030 Tensile Lap Shear ASTM D1002 Specimens: Grit Blasted
Mild Steel (GBMS), 1.6 mm substrate thickness Bondline: 0.05 mm
Testing rate: 200 mm/min Test temperature: Ambient
[0171] Use of this adduct provides a means of incorporating a PDMS
into the cured epoxy network via the masked isocyanate
functionality which is unblocked during cure.
* * * * *