Note: Descriptions are shown in the official language in which they were submitted.
1- 204~8~0
PREPAP~ATION AND USE OF RESINS THAT ARE RELATIVELY NON-
INFT~ rMAFiT~ AND RESISTANT TO HIGH TEMPERATURES
FIELD OF THE INVENTION
This invention refers to resin mixtures which may be cured
to form polymeric resins which are difficultly inflammable and
resistant to high temperatures; to a method for preparing said
polymeric resins; as well as to the use of said polymeric resins.
BACKGROUND OF THE INVENTION
Compounds containing 1-oxa-3-aza tetraline groups and their
prepolymers (hereafter jointly called "oxazene resins" by
convenience) are known, for example from the publications CH-A5-
574,978, CH-A5-579,113 and CH-A5-606,169.
From the publication EP-A1-0,356,379 a resin mixture is
known which may be cured to form polymeric resins which are
difficultly inflA~l-~,hle and resistant to high temperatures. Said
resin mixture i5 at least partially a mixture of:
(a) a resin component comprising or consisting of at least
one thermically curable 1-oxa-3-aza tetraline groups
2 0 containing compound; and of
(b) a flame retardant which is not miscible with resin
component ( a );
and optionally also contains at least one curable epoxy compound.
It is true that by curing said known resin mixture, products
which are difficultly inflammable and resistant to high
temperatures may be obtained. However, their properties are
still not suf f icient for many uses, since the mechanical and
'
- 2 - 2042840
electrical properties are deteriorated by the flame retardant
additive ( b ) .
SUM~ARY OF THE INVENTION
An object of the present invention is to eliminate the
disadvantages of the prior art described above, and to further
improve the behaviour in f ire of oxazene resins without
deteriorating their other properties.
According to the present invention, this object is met by
a resin mixture which may be cured to form a polymeric resin
10 which is difficultly inflammable and/or resistant to high
temperatures, said resin mixture comprising
(a) a component consisting of at least one thermically
curable 1-oxa-3-aza tetraline groups containing
compound;
(b) a component consisting of at least one curable
halogenated epoxy resin; optionally
(c) a component consisting of at least one curable non-
halogenated epoxy resin; and/or optionally
(d~ a curing agent for epoxy resin~
`~ 2042~9~
-- 3
EM33ODIMENTS OP THE INVENTION
The compounds containing 1-oxa-3-aza tetraline grouPs of
component (a) are obtained, for example, from Phenols bY re~c-
tion with formaldehYde and an amine, approximately according to
formula (A):
1~ ~ 2 11 $,~ ( A )
R , ~ ~ ,
1-oxa-3-~za tetral ine group
Por example, R is hydrogen, halogen, alkyl or alkoxy, and
R ' i g a n a 1 i Pha t i c or aroma t i c group .
However, the comPounds cont~ i n i ns 1-oxzl-3-~ za tetra 1 i ne
groups of comPonent (a) can also be PrePared by other methods
resulting into simi lar products .
In contrast to other known condensation reactions of Phe-
nols, ~mines and formaldehYde, in the reaction outlined above
phenolic OH-grouPs are consumed. It is thereby Possible, ac-
cording to the formula (A) hereinabove, to determine the amount
of the synthesized 1-oxa-3-aza tetraline groups from the ana-
lytic determination of the said OH-grouPs in the reaction mix-
ture .
PrePolymers of 1-oxa-3-aza tetraline groups containing com-
pounds are Z!180 useful for PreParins said oxazene resins. ~ince
~ome of the 1-oxa-3--aza tetraline grouPs may react during poly-
20~2840
-- 4
said 1-oxa-3-aza tetral ine groups than provided by the monomers
used to form such Prepolymers. However, it is essential that
the intermediately formed or hypothetic monomer reaction pro-
duct does in fact contain 1-oxa-3-aza tetral ine groups . This
can easily be calculated by a Person skilled in the art from
the functional itY, An 1-oxa-3-aza tetral ine comPound, or its
PrePolymer, useful in accordance with the present invention is,
for example, formed if the molar ratio is kept within the lim-
its defined in the abovementioned Publication CH-AS-606,169.
Phenol or phenol derivatives as well as amines and formal-
dehyde are used as starting or basic materials for preParing
the oxazene resin.
Preferably, for the present invention, 1-oxa-3--aza tetra-
l ine groups containing comPounds are used which are formal ly
derived from a Phenol and an amine, one of said components be-
i ng more than mo no f un c t i o n a l .
Examples of Phenols which can be used are:
-- Monovalent Phenols, such as phenol, m- ~nd P-cresol, m- ~Ind
p-ethyl Phenol, m- and p~isoPropyl phenol, m- and P-isoPro-
PYIoxy Phenol, m-- and P-chloro Phenol, and beta-naphthol.
Para- and met~-sub3tituted phenols are Preferred, since
they do not include anY blocked reactive positions. Also
preferred are the Phenols which are not alkYl substltuted
and not alkyloxY substituted, resPectivelY.
- Bivalent Phenols, such as 4,4 '--dihydroxydiphenyl methane,
3, 3 ' -dihYdroxydi Phenyl methane, 2, 2 ' -bis- (4-hYdroxYPhenyl )
propane, 4,4'-dihydroxy stilbene, hYdroquinone, and resor--
cin .
2-~428~0
. .
.
-- 5
- Low-condensed Phenolic formaldehYde novolak resins, eventu--
al ly mixed with a phenol .
Examples of amines which are particularly useful are:
-- Aniline, phenylene diamine, benzidine, diaminodiphenyl
methane, 2,2'-bis-(aminoPhenYl~ propane, cYclohe~ylamine,
ethylenediamine and proPYlenediamine, in particular
P-phenYlenediamine and 4,4'-diaminodiPhenyl methane,
aromat i c ami nes be i ng pre f erred .
Also particularly useful are 1-oxa-3-aza tetraline com-
pounds which are derived from a novolak and an aromatic amine,
PreferablY from a novolak having a degree of polYmeriz~tion of
about 2 and of aniline, or from phenol and an aromatic diamine.
Preferably, the second component (b) comprises or consists
of:
-- one or several glYcidyl ethers of halogenated Phenols, in
Particular POlyvalent phenols,
-- one or several glYcidyl ethers of condensation Products of
h~logenated Phenols with aldehYdes or ketones, or
-- one or several glYcidyl ethers of halosenated novolak3.
ParticularlY useful are the glYcidyl ethers of halogenated
bisPhenol A or of halogenated bisphenol ~, in particular tetra-
bromo bisPhenol ~ or tetrabromo bisPhenol F, as wel 1 as bromin-
a t e d novo 1 aks .
Prefer~bly, the halogenated epoxY resin of component (b) is
a brominated epoxY resin.
Such brominated ePoXy resin3 are known and commercial ly
avai lable. Also, they were already proposed, a3 sole component,
for Preparing difficultlY inflamm~ble PolYmeric resins. How-
ever, ~aid polYmeric resins show the fol lowing essential draw-
1~ . .~ 1, ~ .
-- 6
204284a
- They have gla~s transition temperatures which are too low.
- In the case of combustion, they produce con~ider~ble qu2n-
tities of the highlY toxic carbonyldibromide, due to their
high bromine content.
-- They are expensive.
Product No .
(Trade Name: "D.E.R. 511-A 80" of The Dow Chemical CompanY):
Brominated epoxY re~in of the bisphenol-A type in an ace-
tone solution.
Epoxide equivalent weight 1) 445... 520
Visc03ity (25C): 1000.. 4000 mPa-s
Non-volati les: 80+1 percent bY weight
Solvent: Acetone
Color ~ccording to Gardner,
m~ximum: 5
Bromine content 1): 19.... 21 percent bY weight
Flash point (T.O.C. ): 63 C
Product No. 2
(Trade Name: "D.E.R. 511-EK 80" of The Dow Chemical Company):
Brominated ePOXY resin of the bisphenol-A tYPe in a methyl
ethyl ketone ~olution.
Epoxide equivalent weisht 1): 445... 522
Vi~cosity ~25C): 1000.. 4000 mPa c~
Non-volatiles: 80+1 percent bY weiyht
Solvent: MethYl ethyl ketone
Color according to Gardner,
m~x i mum: 9 ~ _
Bromine content 1) 19.... 21 percent by weight
Fla~h point (T.O.C.): 52 C
* a trade-mark
~ -- 7
20428~0
Product No. 3
(Trade Name: "D.E.R. 512-A 80" of The Dow Chemical Company):
Brominated epoxY resin of the bisPhenol-A type in an ace- -
tone solution.
Epoxide equivalent weight 1) 480... 560
Viscosity (25C): 700... 2500 mPa-
Non-volatile3: 80+1 percent bY weight
Solvent: Acetone
Color according to Gardner,
maximum: 5
Bromine content 1 ~: 21 . . . 22 , 5 percent bY weight
Flash point (T.O. C. ): 56 C
Product No. 4
(Trade Name: "D.E.R. 512-EK 75" of The Dow Chemical ComPany):
Brominated epoXY re:3in of the bisPhenol-A tYpe in a methyl
ethYl ketone solution.
Epoxide equivalent weight 1) 480... 560
Vi~co-~itY (25C): 500... 1500 mPa s
Non-volatiles: 75+1 percent bY weight
Solvent: MethYl ethYl ketone
Co l or ~ccord i ng to Gardner,
maximum: 3
Bromine content 1) 21.... 22,5 PerCent bY weight
Flash point (T.O.C.): <-2 C
Product No. 5
(Trade Name: "D.E.R. 512-EK 8~' of The Dow Chemical ComPany):
Brominated epoxy resin of the bi~Phenol-A tYPe in ~ methyl
ethYl ketone solution.
Epoxide equivalent weight 1) 480... 560
Viscosity (25C): 1000.. 3500 mPa-s
Non-volatiles: 80+1 Percent bY weight
Solvent: MethYl ethyl ketone
* a trade-mark
_ .~
... ~
. ~
-- 8
20~2840
Color according to Gardner,
maximum: 5
3romine content 1) 21.... 22,5 percent by weight
Flash point (TØC. ): 52 C
Product No. 6
(Trade Name: "D.E.R. 521-A 80" of The Dow Chemical Company):
Bromin~ted ePOxY re~in of the bisPhenol-A tyPe in an ace-
tone solution.
Epoxide e~uivalent weight 1) 430,.. 475
Viscosity (25C): 1000.. 4500 mPa-s
Non-volatiles: 80+1 percent by weight
Solvent: Acetone
Color according to Gardner,
maximum: 6
8romine content 1) 19.... 22 percent by weight
Flash point (T.O.C. ): 63 C
Product No. 7
(Trade Name: "D.E.R. 542" of The Dow Chemical ComPanY):
~rominated ePOXY resin of the bisPhenol-A tyPe.
Epoxide equivalent weight 1) 305,.,355
Softening point according to
Durran: 50,5.. 62,5 C
8romine content: 44.... 49 percent by weight
Flash point (T.O.C. ): 199 C
Product No. 8
(Trade Name: "D.E.R. 566-A 80" of The Dow Chemical ComP~nY):
~3rominated epoxy resin of the bisPhenol-A tyPe in an ace-
tone solution.
EPoxide e~uivalent weight 1) 410... 450
Viscosity (25C): 800... 4000 mPc s
Non-volatile: 80+1 percent by weight
* a trade-mark
~; ~
.. , .. _ , ... . . . _
- 9
2042840
Solvent: Acetone
Color accordins to Gardner,
maximum: 5
Bromine content 1) 18.. 20 percent bY weight
Fl ash poi nt (T . O . C . ): < 2 C
Product No. 9
(Trade Name: "QUATREX 6410'' of The Dow Chemical ComPany):
Brominated epoxY resin of the bi~phenol-A type.
Epoxide equivalent weight 1) ~50
Softening Point: 80 C
Viscosity (150C): 0,0180 m2.3-1
Hydrolyzable chloride: <150 ppm
Volatiles: <0,25 percent bY weight
Bromine content: 47.. 51 percent bY weight
Glass transition temperature
~fter phenolic curing: 175 C
1) Based on the solids content
PreferablY, the halogen content i~ le3s th~n 3 gram equiva-
lents, in Particular less than 2 equivalent3, based on 1 kilogr~m
ot the total weight of the abovementioned components (a) to ~d).
Consequently, in resins containing a brominated expoxy re~in
as comPonent (b), the bromine content is PreferablY lesq than 24
percent bY weight, in Particular le~s than 16 percent by weight,
based on the total weight of the resin. Even with bromine con-
tents as low as 7.5, 2.5, and 1 Percent by weight, respectively,
flame retsistant can be obtained.
* a trade-mark
2~4284~
-- 10 --
Preferably, the quantitY of component (b) is le58 than 50
percent by weight, in particular less than 30 Percent by weight,
based on the total weight of the resin (component (a) + com-
ponent (b) ) . However, fl~me re3istant resins are already ob-
tained with quantities of less than 15 Percent bY weight, or of
less than 5 percent by weight, or even of less than 2 Percent by
weight of component (b), based on the total weight of the resin.
The fact th~t the advantages described hereafter may be ob--
tained with such sm~l l quantities of the component (b), in par-
ticular of a brominated epoxy resin, was highlY surprising to a
person ski l led in the art.
It iB a particular advantage that - beside an essential lY
improved thermic behavior in combination with excellent electri-
cal properties which will be explained hereafter in detail - in
the c~se of combustion theY Produce onlY smal l quantitie-q of
toxic comPounds, and that only a small quantity of the expensive
component (b) must be used.
The mixture according to the invention may also comprise a
component tc) comPriSing or consisting of at least one non-halo-
genated ePOxY resin. AdvantageouslY, the quantitY of said com-
ponent (c) iq les3 th~n the qUantitY of comPonent tb), and Pre-
ferably les3 than h~lf the quantitY of component tb).
Such suitable epoxy resins ~re in particular monofunctional
or multifunctional epoxy compounds which can be cured thermical-
ly, catalyticly or bY means of a curing ~gent.
The mixture according to the invention may also comprise as
component td) ~ curing agent for ePOXY resins. Polyvalent
amines, Polyvelent carboxylic acids and their anhYdrides, di-
cyano diamide, as well a~ novol~ks are ParticularlY useful aq
such curing agents.
2~42~4~
11 --
Suitable epoxy comPounds and curing agent ~re, for example,
described in:
-- Sidney H. Goodman, Handbook of Thermoset Plastics, Noyes
Publications, Park Ridge, NJ:
- W. G. Potter, EPoxide Resins, Ilife Books, London:
- Henry Lee ~nd Kris Nevi 1 le, Handbook of EpoxY Resins,
McGraw-Hill Book ComPanY, New York/San Francisco~Toronto/
London .
By therm i c a l l Y c ur i n g the aboYeme nt i on e d c ura b l e re 9 i ns at a
temperature of above 100 C, in particular at a temPer~tUre of
140 to 220 C, PolYmeric resins which are difficultly inflamma--
ble, resistant to high temPer~tures and heat resistant can be
obta i ned .
Surprisingly, the ProPerties of the Polymeric resins cured
as explained above can sti l l be considerably imProved bY a ther-
mic aftertreatment. Thus, for ex~mPle, ~Y temperlng them for 24
hours at a temPerature of 220 C, the glass tran3ition tempera-
ture ri3es up to more thiln 280 C.
Advantaseously, the cured polymeric resins are subiect to
said thermic aftertreatment at a temPerature of 180 to 250 C,
and PreferablY at a temperature of 200 to 230 C. The duration
of said temPering dePends on the temperature . The fol lowing
standard values maY serve as a basis however, the durations can
be extended at wi l l without deterioration of the PolYmeric res-
ins:
Curing:
4 hours at 180 C: or
2 hours at 200 C.
`~ 20~28~0
-- 12 --
Tempering:
24 hours at 220 C.
Also, these durations can be proportionally combined at will.
For example. the following temPering cycle has proved its value:
30 minutesJ200 C + 30 minutes/220 C + 30 minute~/230 C
30 minutes/250 C.
The ProPerties of the Polymeric resins Produced as described
~bove can be tailored for cert~in aPplicationq bY addition of
usual additives . The fol lowing additives are of particular im-
port~nce:
reinforcement fibers, such as glass, ~uartz, carbon, mineral
and synthetic fibers, in the usual forms of short fibers,
staPle fibers, thre~d3, fabrics or mats:
plastici2ers, especially phosphorous compound~:
c~rbon black or graPhite:
fillers;
dye~tuf fs:
micro hol low sPheres:
metal Powder:
catalysts and
flame retardants, in particular the following groups of com-
pounds, and comPounds, resPectivelY:
aluminium hydroxide:
hydrated calcium magnesium carbonate:
magnesium hydroxide:
e l ementa l red PhosPhorous:
oxygen acid~ of Phosphorous:
inorg~nic salts of oxygen acids of PhosPhorous:
org~nic 3alts of oxygen acids of phosphorous;
po lYphosph~tes .
boric acid:
4284~
-- 13 --
The methods known for processing thermic~l ly cur~ble Phenol
formaldehyde resins or EP resins, such as hot-pressins of pre-
pregs, SMC (Sheet Molding ComPound): or molding of molding com-
pounds, c~sting, filament winding, vacuum imPregnating, may be
used for Proce3sins the resins according to the invention.
The PolYmeric resins which can be obtained by curing, or by
curing followed by tempering the resins according to the inven-
tion, ~nd which are difficultlY inflammable ~nd resistant to
high temPer~tures, are particularly suitable for the following
u~es:
- ~ electric insulating materi~ls, in P~rticular for printed
circuit boards:
- for supporting structures, in Particular in aircr~ft con-
struct i ons
-- wherever resins which ~re flame-re~i tant or resistilnt to
hish temPer~tures are to be used;
- as adhesives.
EXAMPLES
1. St~rting m~terial~ --
The following starting materials are used in the following
exam ~ l~s -
~ 2042840
-- 14 --
Component (a):
(A/1) Oxazene resin 1Reaction product of phenol with aniline and formaldehyde
in ~ molar ratio of 1:1:2, having the structural formula:
( A/2 ) Oxaze ne res i n 2
Reaction Product of 1 mole (2 e~uivalents) of the novolak
obtained bY reacting 2 moles of Phenol and 1 mole of
form~ldehYde, with 2 moles of aniline and with 4 moles of
formaldehyde, having the the following average composi-
tion:
~~ N~c~l2~N ~
(A/3) Oxazene regin 3
Reaction Product of 4,4'--di~mino-diPhenYlmeth~ne with
phenol and formaldehYde in a molar ratio of 1:2:4, having
the ~ tru c tura l f ormu l a:
-
~ 42~0
-- 15 --
~N~CHz~N~
Component (b):
(B/1) Brominated ePoxy resin 1 - -
"D.E.R 542" of The Dow Chemical Company
Bromine content, based on solids: 44..... 49 Percent by weight
(BJ2) Brominated ePOxY resin 2
"Qu~trex 6410" of The Dow Chemical ComPanY
Bromine content, based on solids: 47...51 percent by weight
Reinforcins material
(R) Glass cloth
"Type 90085" of Interglas--Textil GmbH
Surface densitY: 108 g/m2
Number of threads/cm: 24x24
EpoxY silane fini~h
2. Prep~ration of samples
The components 3Pecified in Table 1 were mixed under re-
duced Pressure at 100 bi~ 130 C. Then, the s~mPles for the
thermal analysi~ were withdrawn. The remainder was soaked up,
with or without glass cloth, between tef lonized glass Plates
~nd cured in an circulating air oven for 2 hours at 200 C.
.
2~42~40
-- 16 --
The term "Ref . " means the intern~l reference number of Ap--
P l i cant .
3. Flame-resistance test
The flame-resistance test was made according to UL Specifi-
c~tion 94 (Vertical Test), abreviated: "UL 94" (cf.: Jurgen
Troitzsch. Brandverhalten von Kunststoffen (1982 Munich/Vienna
ISBN 3-446-13391-7), Pages 396 to 399).
The results are compiled in Table 1.
It was surPrising that Class UL-94-V0 can alre~dy be ob-
tained bY an addition of 20 percent bY weight of brominated
epoxy resin, for glass cloth reinforced samples alre~dY by an
addition of 10 percent bY weight.
4 . Me chan i ca l Prop ert i es
The mechanical properties and the glass transition temPera-
ture Tg (also called "glass temPer~ture") were determined, with
or without tempering, by means of
- DCS ("Differenti~l Sc~nning Calorimetry"),
-- DMA ~"Differential Mechanical AnalYsi~"), and
- TMA ("Thermo Mechanic~l AnalYsis").
The results are compiled in Table 2.
It was extremelY surPrising that the rise in the glass
tranE~ition temperature obtainable bY a temperins is associated
with an essentially reduced drop of the E' module at thi~3 tem-
Perature ~cf. in Parti.n~ .. S~.m~lQ.~ f 1~ 71_r~
~ 428~0
-- 17 --
Table 1: Composition of s~mples (P~rts by weight)
Flame-resistance test according to UL 94
.
SamPle < - ComPosition---- > <-Fl~me resistance UL 94-> Ref.
No.<----(a~---> <-(b)-> Glass Thick- Duration of Class
A/1 A/2 A/3 B/1 B~2 R ness combustion
1 ayers mm s
1st 2nd
ignition
0, 80 4, 0 4, 8 V1 Kb70
2 90 10 9 0,92 2,8 3,0 V0 Kb70-G
3 80 20 0, 80 1, 7 0, 7 V0 Kb71
4 80 20 9 0, 90 1, 5 0, 5 V0 Kb71--G
1, 00 0, 0 2, 0 V0 17-1
6 85 15 1, 03 0, 0 0, 3 V0 17-3
7 80 20 1, 05 0, 0 0, 0 V0 17-2
8 90 10 1,07 11,7 14 V1 17-4
9 85 15 1, 03 6, 7 7, 3 V1 17-6
1, 04 1, 7 3, 7 V0 17-5
11 95 5 9 1, 04 10 3 V1 17-9
12 97,5 2.5 9 1,02 13 10 V1 17-8
13 99 1 9 1, 02 33 10 V1 E1
14 80 20 1, 00 3 2 V0 E2
Comparative test --
-- 100 9 1, 02 Burns up to top 17-7
`~ 20~2840
-- 18 --
Table 2: Mechanical propertie3
SamPle Curing/ <~ Strength-------> <----DMA- -> TMA DCS Pef.
No.temper- 3ending E module Thick- 1), 2) 3) 4)
ing~trength ness E'go E' 180 Ts Ts
h/CN/mm2 N/mm2 mm GPa GPa C C
2/200 4.8 1.2 182 171 K~70
22/200 522+14 23'500 0.91 2.7 2.4 Kb70-G
32/200 118+5 11,800 0.85 5.8 178 K~71
+24/220 103+21 14,800 5.7 4.9
+72/220 112+29 14,400 5.4 4.7
42/200 495+14 22,300 0.91 3.0 1 6 178 Kb71-G
+ 2/220 4, 4 4, o
+24/220 8 . 5 8 . 2 280
181 17-1
6 179 17-3
7 184 17-2
8 162 17-4
9 158 17-6
156 17-5
Remark~:
1) "Differential Mechanical ~n~lysi~"
2) Only 1 laYer of slas~ fi~ers d = 0,11...0,2 mm
3) "Thermo Mechanical ~naly~
4) "Differential Scanning Calorimetry"
