CURABLE BISMALEIDE SYSTEMS

SYSTEMES A BASE DE DIMALEIDE DURCISSABLE

English Abstract

There are disclosed novel compositions comprising
a) at least one bismaleide,
b) at least one mono- or polynuclear alkenylphenol, one alkenylphenol ether or
a mixture
thereof, wherein the alkenyl group contains at least three 3 carbon atoms,
c) a copolyether resin.
The compositions of the invention can be cured to products having improved
toughness
and high glass transition temperatures. These products are suitable for making
high-performance moulded articles which can be subjected to high temperatures,
for
example fibre-reinforced composites, structural adhesives, laminating or
electrical
insulating resins.

Claims

12
CLAIMS:
1. A composition comprising
a) at least one bismaleimide of formula I
<IMG>
wherein R1 and R2 are each independently of the other hydrogen
or methyl and A is a divalent organic radical of 2 to 30 carbon
atoms,
b) at least one mononuclear or polynuclear
alkenylphenol, an alkenylphenol ether or a mixture thereof,
wherein the alkenyl group contains at least three carbon atoms,
c) a copolyether resin containing end groups -OR3
attached direct to phenyl nucleic and 1 to 50 mol % of
structural repeating units of formula II
<IMG>
and 50 to 99 mol % of structural repeating units of formula III

13
<IMG>
wherein R3 is hydrogen or a radical of formulae IV to VII
<IMGs>
X is a direct bond or a group of formulae -CrH2r-, -CH(C6H5)-,
-C(CF3)2-, -S-, -SO-, -SO2-, -O- or -CO-, r is 1 to 20, R4 is
prop-1-enyl or 2-methylprop-1-enyl, R5, R6 and R7 are each
independently of one another C1-C4alkyl, C1-C4alkoxy or chloro or
bromo, m, n and t are each independently of one another 0, 1 or
2, p is 1 or 2. E is a divalent radical of a bisphenol after
removal of both phenolic hydroxyl groups, which radical is
unsubstituted or substituted by one or two C1-C4alkyl or
C1-C4alkoxy groups or one or two chlorine or bromine atoms, Y
and Z are each independently of the other -CO- or -SO2-, R8 is
vinyl, ethynyl, allyl, methallyl, prop-1-enyl or 2-methylprop-
1-enyl, R9 and R10 are each independently of the other hydrogen,
allyl or methallyl, R11 is hydrogen or methyl, q is 1 or 2, G is
a group of formulae VIII or IX,

14
<IMG>
wherein R12 is hydrogen or methyl and s is 0, 1 or 2.
2. A composition according to claim 1, wherein R1 and R2
are hydrogen.
3. A composition according to claim 1 or 2 containing a
compound of formula I, wherein A is -C2H2u-, in which a is 2-20,
phenylene, xylylene, naphthylene, cyclopentylene, 1,5,5-
trimethylcyclohexyl-1,3-ene; cyclohexyl-1,4-ene; 1,4-
bis(methylene)cyclohexylene, the radical of 4,4'-
bis(cyclohexyl)methane or a group of formula X,
<IMG>
wherein R13 and R14 are identical or different and are each
hydrogen or C1-C4alkyl, R15 and R16 are each independently of the
other a hydrogen or halogen atom, and T is a direct bond,
methylene, 2,2-propylidene, -S-, -SO-, -SO2-, -O- or -CO-.
4. A composition according to claim 3, wherein A is a
group of formula X, wherein R13 and R14 are each independently of
the other hydrogen, methyl or ethyl, R15 and R16 are hydrogen and
T is methylene.

15
5. A composition according to claim 1, wherein the
compound of formula I is methylenebis(phenylmaleimide).
6. A composition according to any one of claims 1 to 5,
wherein component b) is a compound of formula XI
<IMG>
wherein Q is a direct bond, -CH2-, -C(CH3)2-, -S-, -SO-, -SO2-,
-O- or -CO-, R17, R18, R19 and R20 are each independently of one
another hydrogen or C3-C10alkenyl, and at least one of R17 to R20
is an alkenyl group, and R21 is hydrogen, C1-C10alkyl, C6-C10aryl
or C3-C10alkenyl.
7. A composition according to claim 6, wherein the
alkenyl group in formula XI is an allyl, methallyl or propenyl
group.
8. A composition according to claim 6, wherein Q is
-CH2-, -C(CH3)2-, -S-, -SO2-, -O- or -CO-, R17 and R19 are each
allyl, R18 and R20 are each hydrogen and R21 is hydrogen.
9. A composition according to claim 6, wherein Q is
-C(CH3)2-, R17 and R19 are each allyl, R18 and R20 are each
hydrogen, and R21 is hydrogen.
10. A composition according to claim 1, wherein the
indices m, n and t are 0, and p and q are 1.
11. A composition according to any one of claims 1 to 10,
wherein R3 is hydrogen or a radical of formula V, wherein R9 and
R10 are each hydrogen and q is 1.

16
12. A composition according to any one of claims 1 to 11,
wherein X is a direct bond, -CH2-, -CH(CH3)-, -CH(C6H5)-,
-C(CH3)2-, -C(CF3)2-, -S-, -SO-, -SO2-, -O- or -CO-.
13. A composition according to any one of claims 1 to 11,
wherein X is a direct bond, -CH2- or -C(CH3)2-.
14. A composition according to any one of claims 1 to 13,
wherein R4 is prop-1-enyl.
15. A composition according to any one of claims 1 to 14,
wherein the substituents R4 in formula II are each in ortho-
position to the phenolic -O- atom.
16. A composition according to any one of claims 1 to 15,
wherein E is a group of formulae XII to XIV
<IMG>
wherein L is a direct bond, a group of formulae -CrH2r- (r=1 to
20) , -CH(C6H5)-, -C(CF3)2-, -S-, -SO2-, -O- or -CO-, or is a
group of formula XV or XVI
<IMG>
17. A composition according to claim 16, wherein E is a
group of formulae XII, XIII or XIV, wherein L is a direct bond
or a group of formula -CH2-, -CH(CH3)-, -CH(C2H5)-,
-C(CH3)(C2H5)-, -C(CF3)2-, -S-, -SO2- or -CO-.

17
18. A composition according to any one of claims 1 to 17,
wherein Y and Z have the same meaning.
19. A composition according to any one of claims 1 to 18,
wherein component c) is a copolyether resin comprising 2 to 30
mol % of structural repeating units of formula II and 98 to 70
mol % of structural repeating units of formula III and having
an average molecular weight (number average) of 2,000 to
30,000.
20. A composition according to claim 19, wherein the
average molecular weight (number average) is 5,000 to 20,000.
21. A composition according to any one of claims 1 to 20,
which contains 5-100 % by weight of component c), based on the
amount of component a).
22. A composition according to any one of claims 1 to 20,
which contains 10-50% by weight of component c) based on the
amount of component a).
23. A composition according to any one of claims 1 to 22,
wherein the molar ratio of component b):a) is (0.5-1.4):1.
24. A composition according to claim 23, wherein the
molar ratio is (0.7-1.2):1.
25. A process for the preparation of cured products,
which comprises the use of a composition as claimed in any one
of claims 1 to 24.

Description

-1-
K-18091/A
Novel curable bismaleide systems
The present invention relates to compositions comprising bismaleides, an
alkenylphenol
and/or an alkenylphenol ether and a copolyether resin, as well as a process
for making
cured products using the compositions of the invention.
A process for the preparation of crosslinked polymers containing imide groups
by reacting
polymaleimides and alkenylphenols and/or alkenylphenol ethers is disclosed in
US patent
specification 4 100140. Curable compositions of propenyl-substituted
copolyether resins
and bismaleimides (BMI) are disclosed in EP-A 327 498, which compositions may
be
used and processed in the conventional manner for thermoplastics and exhibit
the
characteristic properties of thern~oset plastics after curing, for example
high strength and
glass transition temperature.
It is the object of this invention to provide BMI systems which have greater
toughness and
high glass transition temperatures and which can be processed and cured at
relatively low
temperatures.
Specifically, the invention relates to compositions comprising
a) at least one bismaleimide of formula I
O O
R R1
t
R2 ~O O _R2
wherein Rt and R2 are each independently of the other hydrogen or methyl and A
is a divalent
organic radical of 2 to 30 carbon atoms,
b) at least one mononuclear or polynuclear alkenylphenol, an alkenylphenol
ether or a mixture
thereof, wherein the alkenyl group contains at least three carbon atoms,
c) a copolyether resin containing end groups -OR3 attached direct to phenyl
nuclei and 1 to

CA 02042857 2000-09-11
29276-439
2
50 mol % of structural repeating units of formula II
(R5)m (RS) m (Rs)
/ / /
O X O Y
w w ~ (B),
(Ra) P (Ra) P
and 50 to 99 mol % of structural repeating units of formula III
(R~) t
/ i
O - E - O ~ Z (III),
(R~) t
wherein R3 is hydrogen or a radical of formulae IV to VII
/ /
(Ra) q (N), N(R9R~o~ 4
\ \
O
O
N G q (VI], - CH2~ (VII),
R»
O
-CH (C6H5) -,
X is a direct bond or a group of formulae -CrHzr-,
-C (CF3) 2-, -S-, -SO-, -SO2-, -O- or -CO-, r is 1 to 20, R4 is
prop-1-enyl or 2-methylprop-1-enyl, R5, R6 and R7 are each
independently of one another C1-C4alkyl, C1-C4alkoxy or chloro or
bromo, m, n and t are each independently of one another 0, 1 or

CA 02042857 2000-09-11
29276-439
2a
2, p is 1 or 2, E is a divalent radical of a bisphenol after
removal of both phenolic hydroxyl groups, which radical is
unsubstituted or substituted by one or two C1-C4alkyl or
C1-C4alkoxy groups or one or two chlorine or bromine atoms, Y
and Z are each independently of the other -CO- or -SOz-, R$ is
vinyl, ethynyl, allyl, methallyl, prop-1-enyl or 2-methylprop-
1-enyl, R9 and Rlo are each independently of the other hydrogen,
allyl or methallyl, R11 is hydrogen or methyl, q is 1 or 2, G is
a group of formulae VIII or IX,

~~~8~~
-3-
(R4~ s
- CH- CH- (VIII), (IX),
Rtz
wherein R12 is hydrogen or methyl and s is 0, 1 or 2.
The bismaleimides of formula I are known compounds and are described, for
example, in US
patent specification ~ 100 140. They are preferably compounds of formula I,
whezein Rl and RZ are
hydrogen.
Preferzed bismaleides are compounds of formula I, wherein A is -C2H2"-, in
which a is 2-20,
phenylene, xylylene, naphthylene, cyclopentylene, 1,5,5-trimethylcyclohexyl-
1,3-ene; cyclo-
hexyl-1,4-ene; 1,4-bis(methylene)cyclohexylene, the radical of 4,4'-
bis(eyclohexyl)methane or a
group of formula X,
Rta Rts Rts Rta
T ~ ~ (x)~
Rts Rts Rts ~Rt3
wherein R13 and R14 are identical or different and are each hydrogen or Cl-
C4alkyl, Rls
and Rlb are each independently of the other a hydrogen ar halogen atom, and T
is a direct
bond, methylene, 2,2-propylidene, -S-, -SO-, -SOZ-, -O- or -CO-.
Particularly preferred compounds of formula I are those wherein A is a group
of
formula X, wherein R13 and Rl~ are each independently of the other hydrogen,
methyl or
ethyl, Rls and R16 are hydrogen and T is methylene.
Methylenebis(phenylmaleimide) is most especially preferred.
Ivlixtures of two or more different bismaleimides may of course also be used.
Representative examples of bismaleimides of formula I are: N,N'-
ethylenebismaleimide,
N,N'-hexamethylenebismaleimide, N,N'-trimethylhexylenebismaleimide, N,N'-m-
pheny-

~~~~~~~1
-4-
lenebismaleimide, N,N'-4,4'-diphenylmethanebismaleimide, N,N'-4,4'-Biphenyl
ether
bismaleimide, N,N'-(1,5,5-trimethylcyclohexyl-1,3-ene)bismaleimide, N,N-4,4'-
dicyclo-
hexylmethanebismaleimide, N,N'-p-xylylenebismaleimide, N,N'-4,4'-bis(2-ethyl-6-
me-
thylphenyl)methanebismaleimide, N,N'-4,4'-bis(2,6-
dimethylphenyl)methanebismale-
imide, N,N'-4,4'-bis(2,6-diethylphenyl)methanebismaleimide, N,N'-4,4'-bis(2,6-
diiso-
propylphenyl)methanebismaleimide, N,N'-4,4'-bis(2-ethyl-6-isopropylphenyl)me-
thanebismaleimide, N,N'-4,4'-bis(3-chloro-2,6-
diethylphenyl)methanebismaleimide.
The compounds of formula I are prepared by known methods, for example by
xeacting the
unsubstituted or substituted malefic anhydride with the corresponding
diamines.
Conventional methods are described in US patent specification 3 010 290 or in
GB patent
specification 1 137 592.
Alkenylphenols or alkenylphenol ethers are known compounds and are described,
for
example, in US patent specification 4100140. Preferred compounds are those of
formula XI
Rig Ris
OR21(~).
Rye R2o
wherein Q is a direct bond, -CH2-, -C(CH3)2-, -S-, -SO-, -S02-, -O- or -CO-,
Rte, R18, R~9 and R2o
are each independently of one another hydrogen or C3-CloaLtCenyl, and at least
one of Rl~ to R2o is
an alkenyl group, and RZt is hydrogen, Ci-Cloalkyl, C6-Cloaryl or C3-
CtoaIkenyl.
The alkenyl group in compounds of formula XI is preferably an allyl, methallyl
or propenyl group.
In the compositions of this invention it is preferred to use compounds of
formula XI, wherein Q is
-CI-I2-, -C(CH3)2-, -S-, -S02-, -O- or -CO-, Rl~ and Rl9 are each allyl, Rl8
and R2o are each
hydrogen and R21 is hydrogen.
Particularly preferred alkenylphenols of formula XI are those wherein Q is -
C(CH3)2-, R17 and Rt9
are each allyl, Rt8 and RZO are each hydrogen, and R2t is hydrogen.
It is preferred to use compounds of formula XI which contain two alkenyl
groups in each molecule.

r~~~~~~~fi~
-5-
Typical examples of alkenylphenols or alkenylphenol ethers which may be used
in the
compositions of this invention are:
o,o'-diallyl bisphenol A,
o,o'-diallyl bisphenol F,
4,4'-dihydroxy-3,3'-diallyldiphenyl,
4,4'-diallyloxydiphenyl.
The corresponding methallyl compounds can also be used.
Alkenylphenols are obtained by (thermal) Claisen rearrangement of the alkenyl
ethers of phenols
(q.v. USP 4 100 140). The alkenyl ethers are also obtained by known methods,
for example by
reacting phenols with allyl chloride in the presence of an alkali metal
hydroxide.
It is also possible to use mixtures of compounds which contain only one
hydroxyl group and only
one alkenyl group in the aromatic nucleus with compounds which contain several
hydroxyl groups
and/or several alkenyl groups in the aromatic nucleus, or mixtures of the
corresponding phenyl
ethers of these compounds.
The alkenyl-substituted copolyether resins containing structural repeating
units of formulae II and
III are disclosed in EP-A 327 498.
In the compositions of the invention it is preferred to use polyether
sulfones/ketones containing
structural repeating units of formulae II and III, wherein the indices m, n
and t are 0 and p an q are
I.
R3 is preferably hydrogen or a radical of formula V, wherein Rg and Rlp are
each hydrogen and q is
1.
The preferred meaning of X in formula II is a direct bond, -CH2-, -CH(CH3)-, -
CH(C6H5)-,
W(~3)2-~ -~(~3)2': S-, -SO-, -SOZ-, -O- or -CO-.
Most preferably X is a direct bond, -CH2- or -C(CH3)2-.
The preferred meaning of Rø is prop-1-enyl.
The substituents I~ in formula II are preferably each in ortho-position to the
phenolic -O- atom.

CA 02042857 2000-09-11
29276-439
6
The group E as divalent radical of a bisphenol is
normally the divalent radical of a mono- or polynuclear
carbocylic-aromatic phenol, preferably the radical of a mono-
or binuclear carbocylic-aromatic phenol, both aromatic nuclei
of which are fused or linked to each other through a linking
group.
Preferred radicals E have the formulae XII to XIV
/ / \
). I (xrm, /. ~ ~ /
\ \ /
to
wherein L is a direct bond, a group of formulae -CrH2r- (r=1 to
20) , -CH (C6H5) -, -C (CF3) 2-, -S-, -SOZ-, -O- or -CO-, or is a
group of formula XV or XVI
(XV), (XV~.
Most particularly preferred radicals E have the
formulae XII, XIII or XIV, wherein L is a direct bond or a
group of formula -CH2-, -CH (CH3) -, -CH (C2H5) -, -C (CH3) (CZHS) -,
-C (CF3) 2-, -S-, -S02- or -CO- .
Y and Z preferably have the same meaning.
Especially preferred components c) are copolyether
resins comprising 2 to 30 mol % of structural repeating units
of formula II and 98 to 70 mol % of structural repeating units
of formula III and having an average molecular weight (number
average) of 2,000 to 30,000, preferably 5,000 to 20,000.

29276-439
CA 02042857 2000-09-11
6a
The compositions of this invention preferably contain
5-100 % by weight, most preferably 10-50 % by weight of
component c), based on the amount of component a).
The molar ratio of component b):a) is preferably
(0.5-1.4):1, preferably (0.7-1.2):1.
The compositions of the invention are cured in known
manner, typically in the temperature range from 100 to 300°C for
a time sufficient to effect the cure.
The expression "cure" as used herein means the
conversion of low viscosity resin compositions into insoluble
and infusible crosslinked products. It is thus possible to
prepare high-performance

_7_
moulded articles such as (fibre-reinforced} composites, structural adhesives,
laminating or
electrical insulating resins which can be subjected to high temperatures.
The compositions of the invention can be mixed at any stage prior to the cure
with conventional
modifiers such as extenders, fillers and reinforcing agents, pigments, dyes,
organic solvents,
plasticisers, tackifiers, tougheners, rubbers, accelerators, flame retardants
or thixotropic agents.
Illustrative examples of suitable modifiers are: coal tar, bitumen, glass
fibres, boron fibres, carbon
fibres, cellulose, polyethylene powder, polypropylene powder, mica, asbestos,
quartz powder,
gypsum, antimony trioxide, bentones, silica aerogel ("aerosil"), lithopone,
barites, titanium dioxide,
carbon black, graphite, iron oxide, metal powders such as aluminium powder or
iron powder,
silicones, cellulose acetate butyrate, polyvinyl butyrate, waxes and
stearates.
Suitable additional tougheners are products which are known to the skilled
parson, such as
polyimicles (for example Matrimid~ 5218, Ciba-Geigy), polyether imides (for
example Ultem~
1000, General Electric), polyether sulfones or ketanes (for example VlCtrex~,
ICI or Ultrason~ E,
BASF) or polyhydantoins.
The compositions of the invention are very readily processible, have good
solubility in customary
organic solvents, good stability in the melt or in solution, and the cured
products made from them
have good thermal and mechanical properties. The products obtained have
enhanced toughness and
high glass transition temperatures.
The invention accordingly also relates to a process for the preparation of
cured products, which
comprises the use of the novel compositions.
The compositions of this invention can be used in different fields, for
example in prepregs,
laminates, composites, printed circuit boards, castings, mouldings, adhesives
and coatings. A
particularly interesting utility is the fabrication of fibre-reinforced
composites.
Example 1
In a round flask, 75 g of o,o'-diallyl bisphenel A is heated to 150°C
and, with stirring, 10 g of a
copolyether resin prepared according to Example 1 of EP-A 327 498 are added.
When the resin has
completely dissolved (15 min), 100 g of methylenebisphenylmaleimide are added,
with stirring.
The mixture is then stirred for a further 15 minutes at 125-130°C,
degassed under a water jet
vacuum, and poured into an aluminium mould (4 mm) of 180°C. The mixture
is fully cured for 1 h
at 180°C, for 2 h at 200°C and, finally, for 6 h at
250°C. The cured product has the following

~~~~~pr
_$_
properties:
291°C
Tg onset~
Tg: 301 °C
flexural strength (according to
ISO 178): 144 MPa
flexural elongation (according to
ISO 178): 4.6 %
(T$ o~et is the point of intersection of the extended base line with the
tangent at the calibzation
curve in the area of the steepest ascent (measured by TMA, using a Mettler TA
3000)).
Example 2: In accordance with the general procedure described in Example 1,1
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 20 g of a copolyether resin
prepared according to
Example 1 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
286°C
Tg onset~
Ts: 296°C
flexural strength (according to
ISO 178): 148 MPa
flexural elongation (according to
ISO 178): ~.0 %
Example 3: In accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 30 g of a copolyether resin
prepared according to
Example 1 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
Tg onset 82 C
Tg: 292C '
flexural strength (according
to
ISO 178): 161 MPa
flexural elongation (according
to
ISO 178): 5.5 %
Example 4: In accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A,10 g of a copolyether resin
prepared according to
Example 2 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:

-9-
299°C
Tg onset~
Tg: 310°C
flexural strength (according to
ISO 178): 107 MPa
flexural elongation (according to
ISO 178): 3.6 %
Example 5: In accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 20 g of a copolyether resin,
prepared according to
Example 2 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
300°C
Tg onset~
Ts: 310°C
flexural strength (according to
ISO 178): 159 IvIPa
flexural elongation (according to
ISO 178): 5.5 %
Example 6: In accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 30 g of a copolyether resin,
prepared according to
Example 2 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
305°C
Tg onset
Ts: 312°C
flexural strength (according to
ISO 178): 157 MPa
flexural elongation (according to
ISO 178): 5.6 %
Example 7: In accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 10 g of a copolyether resin,
prepared according to
Example 5 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
0
304 C
Tg onset~
Ts: 312°C
flexural strength (according to

- to -
ISO 178): 162 MPa
flexural elongation (according to
ISO 178): 5.8 %
Example 8:1n accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 20 g of a copolyether resin,
prepared according to
Example 5 of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
305°C
Tg onset
Tg: 313°C
flexural strength (according to
ISO 178): 165 MPa
flexural elongation (according to
ISO 178): 5.9 %
Example 9: In accordance with the general procedure described in Example l, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 30 g of a copolyether resin,
prepared according to
Example S of EP-A 327 498, and 100 g of methylenebisphenylmaleimide. The
product has the
following properties:
305°C
Tg onset~
Tg: 312°C
flexural strength (according to
ISO 178): 167 MPa
flexural elongation (according to
ISO 178): 6.6 %
Example 10: In accordance with the general procedure described in Example 1, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 50 g of a copolyether resin,
prepared according to
Example 5 of EP-A 327 498, and 10f? g of methylenebisphenylmaleimide. The
product has the
following properties:
314°C
Tg onset~
Tg: 326°C
flexural strength (according to
ISO 178): 170 MPa
flexural elongation (according to
ISO 178): 5.7 %

-11-
Example 11: In accordance with the general procedure described in Example l, a
cured product is
prepared from 75 g of o,o'-diallyl bisphenol A, 50 g of a copolyether resin,
prepared according to
Example 5 of EP-A 327 498, and 50 g of methylenebisphenylmaleimide. The
product has the
following properties;
°
Tg °~et: 300 C
Tg: 308°C
flexural strength (according to
ISO 178): 160 MPa
flexural elongation (according to
ISO 178): 6.0 %
Example 12; 20 g of a copolyether resin, prepared according to Example 5 of EP-
A 327 498, axe
dissolved, with stirring, over 30 minutes at 150°C in 44 g of o,o'-
diaIlyl bisphenol A, and a mixture
of 50 g of methylenebisphenylmaleimide and 50 g of methylenebis(2-ethyl-6-
methyl-
phenyl)maleimide is added. The reaction mixture is stirred for a further 15
minutes at 100°C, then
degassed under vacuum (10 tort) and poured into a hot aluminium mould (4 mm)
of 200°C. The
mixture is fully cured for 1 h at 200°C, for 2 h at 220°C and,
finally, for 6 h at 280°C. The product
has the following properties:
322°C
Tg onset
Tg: 331°C
flexural strength (according to
ISO 178): 151 MPa
flexural elongation (according to
ISO 178): 6.2