Curable compositions containing multiglycidyl ethers and a sulfonic acid amide

Curable compositions are disclosed which comprise a multiglycidyl ether such as the triglycidylether of tris(hydroxyphenyl)methane and an amine substituted sulfonic acid amide such as sulfanilamide. These compositions can be cured by heating in the presence or absence of an accelerator such as 2-methyl imidazole. These compositions are particularly useful in the preparation of electrical laminates.

BACKGROUND OF THE INVENTION 
The present invention pertains to curable compositions containing 
multiglycidyl ethers and a sulfonic acid amide and the resultant cured 
products. 
Pettigrew has disclosed curing epoxy resins with sulfonic acid amides in 
U.S. Pat. No. 3,277,050. Mah and Schrader have disclosed curing glycidyl 
ethers of tris(hydroxyphenyl) alkanes with various curing agents, in U.S. 
Pat. No. 3,787,451 and U.S. Pat. No. 4,394,496, respectively. However, 
Pettigrew does not disclose curing glycidyl ethers of tris(hydroxyphenyl) 
alkanes as suitable epoxy resins and Mah and Schrader do not disclose 
sulfanilimide as a suitable curing agent. 
The applicants herein have found that the products resulting from curing 
glycidyl ethers of tris(hydroxyphenyl) alkanes with sulfanilamide 
unexpectedly have an improvement in toughness (G.sub.1C) while maintaining 
a relatively high thermal transition (Tg) temperature. 
SUMMARY OF THE INVENTION 
The present invention pertains to a curable composition comprising a 
mixture of 
(A) at least one of 
(1) at least one epoxy resin represented by formulas ((I) or (II) wherein 
each B is represented by the formula 
##STR1## 
each B' is represented by the formula 
##STR2## 
each B" is represented by the formula 
##STR3## 
each R is independently hydrogen or an alkyl group having from 1 to about 
4 carbon atoms; each Q is independently hydrogen or a hydrocarbyl group 
having from 1 to about 10 carbon atoms; each R' is independently hydrogen, 
a hydrocarbyl or hydrocarbyloxy group having from 1 to about 10 carbon 
atoms or a halogen; m has a value of n-1; m' has a value of n'-1; m" has a 
value of n"-1; each n, n' and n" independently has a value from zero to 
about 3; q has a value from zero to about 4; and each z and z' 
independently has a value from zero to about 3; 
(2) the reaction product of 
(a) at least one epoxy resin represented by formulas (I) or (II) as defined 
in component (A-1); and 
(b) at least one dihydric phenol represented by formulas (III) or (IV) 
wherein A is a divalent hydrocarbon group having from 1 to about 12 carbon 
atoms; --S--, --S--S--, 
##STR4## 
or --O--; each Y is independently hydrogen, a halogen or a hydrocarbyl or 
hydrocarbyloxy group having from 1 to about 10 carbon atoms; and n has a 
value of zero or 1; and wherein components (a) and (b) are present in 
quantities such that the ratio of phenolic hydroxyl groups to epoxide 
groups is from about 0.01:1 to about 0.5:1, preferably from about 0.05:1 
to about 0.25:1, most preferably from about 0.1:1 to about 0.2:1; or 
(3) mixtures thereof; and 
(B) at least one amine substituted aromatic sulfonic acid amide represented 
by formula (V) wherein each X is independently hydrogen, a monovalent 
hydrocarbyl group having from 1 to about 10 carbon atoms or a halogen; and 
wherein components (A) and (B) are present in quantities such that the 
ratio of epoxy groups to hydrogen atoms attached to a nitrogen atom is 
from about 0.8:1 to about 2:1, preferably from about 0.9:1 to about 
1.25:1. 
Another aspect of the present invention pertains to a composition 
comprising a mixture of 
(A) at least one of 
(1) at least one epoxy resin represented by formulas (I) or (II) wherein 
each B is represented by the formula 
##STR5## 
each B' is represented by the formula 
##STR6## 
each B" is represented by the formula 
##STR7## 
each R is independently hydrogen or an alkyl group having from 1 to about 
4 carbon atoms; each Q is independently hydrogen or a hydrocarbyl group 
having from 1 to about 10 carbon atoms; each R' is independently hydrogen, 
a hydrocarbyl or hydrocarbyloxy group having from 1 to about 10 carbon 
atoms or a halogen; m has a value of n-1; m' has a value of n'-1; m" has a 
value of n"-1; each n, n' and n" independently has a value from zero to 
about 3; q has a value from zero to about 4; and each z and z' 
independently has a value from zero to about 3; 
(2) the reaction product of 
(a) at least one epoxy resin represented by formulas (I) or (II) and 
(b) at least one dihydric phenol represented by the formulas (III) or (IV) 
wherein A is a divalent hydrocarbon group having from 1 to about 12 carbon 
atoms, --S--, --S--S--, 
##STR8## 
or --O--; each Y is independently hydrogen, a halogen or a hydrocarbyl or 
hydrocarbyloxy group having from 1 to about 10 carbon atoms; and n has a 
value of zero or 1; and wherein components (a) and (b) are present in 
quantities such that the ratio of phenolic hydroxyl groups to epoxide 
groups is from about 0.01:1 to about 0.5:1, preferably from about 0.05:1 
to about 0.25:1, most preferably from about 0.1:1 to about 0.2:1, or 
(3) mixtures thereof; 
(B) at least one amine substituted aromatic sulfonic acid amide represented 
by formula (V) wherein each X is independently hydrogen, a monovalent 
hydrocarbyl group having from 1 to about 10 carbon atoms or a halogen; and 
(C) from zero to about 50, preferably from about 10 to about 45, most 
preferably from about 30 to about 40, percent by weight of the combined 
weight of components (A), (B), (C) and (D) of at least one solvent; and 
wherein components (A) and (B) are present in quantities such that the 
ratio of epoxy groups to hydrogen atoms attached to a nitrogen atom is 
from about 0.8:1 to about 2:1, preferably from about 0.9:1 to about 
1.25:1. 
The present invention also pertains to substrates impregnated with the 
aforementioned compositions and to laminates prepared therefrom. 
##STR9## 
DETAILED DESCRIPTION OF THE PRESENT INVENTION 
Particularly suitable amine substituted aromatic sulfonic acid amides which 
can be employed herein include, for example, sulfanilamide, 
4-amino-2-chlorobenzenesulfonamide, 4-amino-2-methylbenzenesulfonamide, 
sulfanilylsulfanilamide, 2-aminobenzenesulfonamide, mixtures thereof and 
the like. 
Particularly suitable trisphenol based epoxy resins which can be employed 
herein include, for example, the triglycidyl ether of 
tris(hydroxyphenyl)methane, higher molecular weight homologs thereof, and 
trisepoxides advanced with dihydric phenols, mixtures thereof and the 
like. 
Particularly suitable dihydric phenols and halogenated dihydric phenols 
include, for example, bisphenol A, tetrabromobisphenol A, bisphenol S, 
tetrabromobisphenol S, biphenol, tetrabromobiphenol, 
tetrabromodihydroxybenzophenone, resorcinol, tetrabromoresorcinol, 
mixtures thereof and the like. 
Suitable catalysts for effecting the reaction between the epoxy resin and 
the phenolic hydroxyl-containing compound include, for example, those 
disclosed in U.S. Pat. Nos. 3,306,872; 3,341,580; 3,379,684; 3,477,990; 
3,547,881; 3,637,590; 3,843,605; 3,948,855; 3,956,237; 4,048,141; 
4,093,650; 4,131,633; 4,132,706; 4,171,420; 4,177,216; 4,302,574; 
4,320,222; 4,358,578; 4,366,295; and 4,389,520, all of which are 
incorporated herein by reference. 
Particularly suitable catalysts are those quaternary phosphonium and 
ammonium compounds such as, for example, ethyltriphenylphosphonium 
chloride, ethyltriphenylphosphonium bromide, ethyltriphenylphosphonium 
iodide, ethyltriphenylphosphonium acetate, ethyltriphenylphosphonium 
diacetate (ethyltriphenylphosphonium acetate.acetic acid complex), 
ethyltriphenylphosphonium tetrahaloborate, tetrabutylphosphonium chloride, 
tetrabutylphosphonium acetate, tetrabutylphosphonium diacetate 
(tetrabutylphosphonium acetate.acetic acid complex), tetrabutylphosphonium 
tetrahaloborate, butyltriphenylphosphonium tetrabromobisphenate, 
butyltriphenylphosphonium bisphenate, butyltriphenylphosphonium 
bicarbonate, benzyltrimethylammonium chloride, benzyltrimethylammonium 
hydroxide, benzyltrimethylammonium tetrahaloborate, tetramethylammonium 
hydroxide, tetrabutylammonium hydroxide, tetrabutylammonium 
tetrahaloborate, and mixtures thereof and the like. 
Other suitable catalysts include tertiary amines such as, for example, 
triethylamine, tripropylamine, tributylamine, 2-methylimidazole, 
benzyldimethylamine, mixtures thereof and the like. 
Other suitable catalysts include ammonium compounds such as, for example, 
triethylammonium chloride, triethylammonium bromide, triethylammonium 
iodide, triethylammonium tetrahaloborate, tributylammonium chloride, 
tributylammonium bromide, tributylammonium iodide, tributylammonium 
tetrahaloborate, N,N'-dimethyl-1,2-diaminoethane.tetrahaloboric acid 
complex, and mixtures thereof and the like. 
Other suitable catalysts include quaternary and tertiary ammonium 
phosphonium, and arsonium adducts or complexes with suitable 
non-nucleophilic acids such as, for example, fluoboric, fluoarsenic, 
fluoantimonic, fluophosphoric, perchloric, perbromic, periodic, mixtures 
thereof and the like. 
Suitable solvents which can be employed herein include, for example, 
ketones, alcohols, glycol ethers and amides, such as, for example, 
acetone, methyl ethyl ketone, methanol, propylene glycol mono methyl ether 
and dimethyl formamide. 
If desired, the composition of the present invention can contain 
accelerators for the reaction between the epoxy resin and the amine 
substituted aromatic sulfonic acid amide. Suitable accelerators include, 
for example, 2-methyl imidazole, 2-ethyl-4-methylimidazole, 
2-isopropylimidazole, 1-propylimidazole, 2-heptadecylimidazole, 
benzyldimethylamine, ethyltriphenylphosphonium acetate, 
ethyltriphenylphosphonium chloride, ethyltriphenylphosphonium bromide, 
ethyltriphenylphosphonium iodide, ethyltriphenylphosphonium diacetate 
(ethyltriphenylphosphonium acetate.acetic acid complex), 
ethyltriphenylphosphonium tetrahaloborate, tetrabutylphosphonium chloride, 
tetrabutylphosphonium acetate, tetrabutylphosphonium diacetate 
(tetrabutylphosphonium acetate.acetic acid complex), tetrabutylphosphonium 
tetrahaloborate, butyltriphenylphosphonium tetrabromobisphenate, 
butyltriphenylphosphonium bisphenate, butyltriphenylphosphonium 
bicarbonate, benzyltrimethylammonium chloride, benzyltrimethylammonium 
hydroxide, benzyltrimethylammonium tetrahaloborate, tetramethylammonium 
hydroxide, tetrabutylammonium hydroxide, tetrabutylammonium 
tetrahaloborate, triethylamine, tripropylamine, tributylamine, 
2-methylimidazole, benzyldimethylamine, triethylammonium chloride, 
triethylammonium bromide, triethylammonium iodide, triethylammonium 
tetrahaloborate, tributylammonium chloride, tributylammonium bromide, 
tributylammonium iodide, tributylammonium tetrahaloborate, 
N,N'-dimethyl-1,2-diaminoethane.tetrahaloboric acid complex, mixtures 
thereof and the like. 
The compositions of the present invention may also contain, if desired, 
pigments, dyes, mold release agents, flow control agents, reinforcing 
agents, fillers, fire retardant agents, rubber modifiers, surfactants, 
accelerators, reactive diluents, mixtures thereof and the like. 
The compositions of the present invention are suitable for such 
applications as structural or electrical laminates or composites, 
coatings, adhesives, castings, moldings, electronic encapsulations and in 
potting compositions. 
Suitable substrates which can be employed herein include, for example, 
fibers or filaments in woven, matt or non-woven form of glass, carbon, 
graphite, synthetic fibers, quartz, ceramic, combinations thereof and the 
like.

The following examples are illustrative of the invention but are not to be 
construed as to limiting the scope thereof in any manner. 
Fracture Toughness Measurement (G.sub.1C) 
The method for measuring G.sub.1C (fracture toughness or "critical strain 
energy release rate") is an adaptation of ASTM E-399 for plastics 
materials from the original usage with metals. The compact tension test is 
now widespread in usage and is described in J. Mater. Sci., Vol. 16, 2657, 
1981. An individual test piece is cut as an approximate 1" (25.4 mm) 
square from a flat casting usually of 1/8" (3.175 mm) thickness. A 
dovetail notch is cut into one edge, centered, about 1/4" (6.25 mm) in 
depth. Next, a razor blade is inserted into this notch and tapped to 
produce a precrack. Two holes are then drilled adjacent to the dovetail as 
indicated in ASTM E-399, allowing the test piece to be pinned into 
position in the Instron test machine. Extension of the sample now allows 
the force required to propagate opening of the precrack to be measured, 
using a test speed of 0.02 inch/minute (0.0085 mm/sec.). This force is 
used in the equation given in ASTM E-399, along with the required sample 
dimensions and actual precrack length, to calculate a "stress 
intensification factor" K.sub.Q. This is then combined with the tensile 
modulus and Poisson's ratio for the material to give the value for 
G.sub.1C, usually reported in ergs/cm.sup.2 .times.10.sup.6. A scale 
comparing typical values for G.sub.1C for various plastics and metals is 
given in reference Lee, L. H., "Physicochemical Aspects of Polymer 
Surfaces", K. L. Mittal, ed. Plenum Press, New York, N.Y., 1983. 
Tg was determined using a DuPont Dynamic Mechanical Analyzer (Model No. 982 
with a DuPont 1090 controller). 
Tensile and flexural properties were measured using ASTM method D-638-60 
and D-790-58T, respectively. 
The following components were employed in the examples and comparative 
experiments. 
Epoxy Resin A was a polyglycidyl ether of a phenol/hydroxybenzaldehyde 
condensation product having an EEW of 163 and an average functionality of 
about 3.2. 
Epoxy Resin B was a polyglycidyl ether of a phenol/glyoxal condensation 
product having an average functionality of about 4.2 and an EEW of 231. 
Epoxy Resin C was a polyglycidyl ether of a phenol/formaldehyde 
condensation product having an EEW of 178 and an average functionality of 
about 3.5. 
Epoxy Resin D was a polyglycidyl amine prepared from p-amino phenol having 
an average functionality of about 3 and an EEW of 187. 
Curing Agent A was sulfanilamide which has an amine hydrogen equivalent 
weight of 43. 
Curing Agent B was methylene dianiline which has an amine hydrogen 
equivalent weight of 49.5. 
Curing Agent C was diamino diphenyl sulfone which has an amine hydrogen 
equivalent weight of 62. 
EXAMPLE 1 
400 g (2.454 eq.) or Epoxy Resin A was heated to a liquid state at 
150.degree. C. To this resin was added 84.9 g of Curing Agent A (0.8 eq. 
sulfanilamide/eq. epoxy) and stirred until completely dissolved. (Note: 
both of these monomers were degassed separately prior to mixing). The 
resin solution was then poured into an aluminum mold with 1/8 inch (0.3175 
cm) inside spacing and placed in the oven at 150.degree. C. The cure 
schedule consisted of 1 hour (3600 s) at 150.degree. C., 2 hours (7200 s) 
at 200.degree. C., 2 hours (7200 s) at 225.degree. C., and 1 hour (3600 s) 
at 250.degree. C. The casting was then cooled to room temperature and 
removed for evaluation. The resultant cured product had the properties 
reported in Table I. 
TABLE I 
______________________________________ 
PRODUCT FROM 
EXAMPLE 1 
______________________________________ 
Tg, .degree.C. 304 
Tensile Strength, 
psi 9,100 
kPa 62,743 
Tensile Modulus, 
psi 5.43 .times. 10.sup.5 
kPa 37.44 .times. 10.sup.5 
Elongation, % 2.4 
Flexural Strength at 77.degree. F. 
(25.degree. C.), 
psi 19,305 
kPa 133,104 
Flexural Modulus at 77.degree. F. 
(25.degree. C.), 
psi 6.55 .times. 10.sup.5 
kPa 45.16 .times. 10.sup.5 
Flexural Strength at 450.degree. F. -(232.2.degree. C.), 
psi 6,815 
kPa 46,988 
Flexural Modulus at 450.degree. F. 
(232.2.degree. C.), 
psi 2.41 .times. 10.sup.5 
kPa 16.62 .times. 10.sup.5 
______________________________________ 
EXAMPLE 2 and COMATIVE EXPERIMENTS 
Epoxy resins and amine curing agents as listed in Table II were blended and 
cured as described in Example 1. Glass transition temperatures (Tg) and 
fracture toughness energy (G.sub.1C) of the corresponding clear castings 
were reported also in Table II. 
TABLE II 
__________________________________________________________________________ 
COMPONENTS 
EXAMPLE 
COMP. COMP. COMP. COMP. COMP. 
AND RESULTS 
2 EXPT. A* 
EXPT. B* 
EXPT. C* 
EXPT. D* 
EXPT. E* 
__________________________________________________________________________ 
Epoxy resin 
A/250/1.534 
A/250/1.534 
A/250/1.534 
B/250/1.082 
C/250/1.404 
D/250/1.337 
type/grams/equiv. 
Curing agent 
A/53/1.233 
B/75/1.515 
C/95/1.532 
A/36/.837 
A/48/1.116 
A/46/1.070 
type/grams/equiv. 
Tg (.degree.C.) 
304 295 308 250 220 240 
G.sub.1C 0.13 0.07 0.08 0.06 0.24 0.09 
__________________________________________________________________________ 
*Not an example of this invention