Note: Descriptions are shown in the official language in which they were submitted.
1~ 09~
.
The invention relates to crystalline, crosslinked
epoxide resins in which the crystallite-forming elements are
essentially aliphatic polyester chains and which have at least
two different crystallite melting points.
In the present document and in accordance with the
present invention, a crystalline epoxide resin is to be
understood as a product which is usually partially crystalline.
Various epoxide resins, all of which contain, as
crystallites, the radicals of a long-chain aliphatic polyes-ter-
polycarboxylic acid, are already known. In this connection,
British Patents 1,164,~84 and 1,283,653 should be mentioned in
particular. These products are crystalline synthetic resins
which exhibit relatively high elongations a-t break below their
crystallite melting point. If they are warmed to a temperature
above the crystal]isation transition temperature, they then
exhibit rubbery-elastic properties. In this rubbery-elastic
state, their dimensional stability is too low for many appli-
cations, for example as constructional materials. However,
this means that these synthetic resins which have a low
crystallite melting point (for example 20 to 50C) cannot be
used for such applications at the customary average tempera-
tures. If the synthetic resins have higher crystallite melt-
ing points (for example of ~70C), their toughness rapidly
decreases at room temperature. For this reason, synthetic
resins of this type also are not very suitable for certain
applications, for example as constructional materials or
bui'ding materials.
- 2 -
10~0~
The object of the invention is to provide crystalline,
crosslinked epoxide resins which do not exhibit this adverse
behaviour of the plastics according to the prior art
discussed above. They must, there~ore, have an adequate
dimensional stability, and in particular be sufficientl.y tough
and flexible,ov~ wide temperature ranges.
The subject of the invention is a process for the
manufacture of crystalline, crosslinked epoxide resins, which
is characterised in that epoxide compounds, containing two or
more epoxide groups, are reacted
a) with polyester-polycarboxylic acids D which essentially
contain segments of the formula I
-[O-(CH2)n-o-co-(cH2)m-co~p- (I)
in which n and m are identical or different and denote 2 or a
higher number than 2, and to which the condition n + m = 6 to
30 applies, and in which p denotes a number from 2 to 40,
which, however, is sufficiently large that the segment con-
tains at least 30 -CH2- groups, and
b) with polyester-polycarboxylic acids E which essentially
contain segments of the formula II
-[O~(CH2)s-o-co-(cH2)r-co~q- (II)
in which s and r are identical or different and denote 2 or a
higher number than 2, and to which the condition s + r + 2
c==n + m applies, and in which q represents a number from
6 to 30, which, however, is sufficiently large that the
segment contains at least 30 -CH2- groups, and
c) if appropriate~ with curing agents C, and, if appropriate,
in the presence of accelerators,
in a ratio such tha-t 0.5 to 1.2 equivalents of polyester-
polycarboxylic acid are present per equivalent of epoxide
compound, that 1/10 to 9/10 of these 0.5 to 1.2 equivalents
are attributable to the poiyester-polycarboxylic acid D and
`the remaining 9/10 to 1/10 to the polyester-polycarboxylic
acid E, and that up to 0.6 equivalent of curing agent C is
present per equivalent of epoxide co~pound, with the proviso
that, in the cases in which only difunctional epoxide com-
pounds and difunctional polyester-polycarboxylic acids D and
E are employed, the epoxide groups must be present in excess
and the reaction with a curing agent C is essential.
Preferably, the condition n + m = 8 to 24 applies in
the formula I.
The epoxide resins obtained according to the invention
are distingulshed by a feature which was previously not kno~n
for synthetic resins. This is that they e~hibit several
pronounced crystallite melting poin~ts,preferably two (Tml and
Tm2j- Tml is in the range from 20 to 70C, preferably
25 to 60C, and Tm2 is in the range from 50 to 120C,
preferably 50 to 100C. The crystallite-forming elements
for Tml and Tm2 are the polyester-polycarboxylic acids D
and E employed in the manufacturing process. Sometimes,
the particular crystallite melting point is split. This
means that in such cases the crystallite melting point mani-
fests itself as a two-stage melt'ng point.
It is surprising that when two polyester segments of
similar structure are employed in crystalline~ crosslinked
polymers, two different crystallites are formed and, even when
the content of one component is relatively low, the melting
point of this component is only slightly influenced.
Preferably, the procedure followed according to the
invention is such that 0.7 to 1.2, especially O.9 to 1.1,
equivalents of polyester-carboxylic acid are present per
equivalent of epoxide compound.
The polyester-polycarboxylic acids D and E used in the
reaction can for practical purposes be manufactured by the
same basic process, by esterification of corresponding ali-
phatic dialcohols and aliphatic dicarboxylic acids or by
forming esters of suitable derivatives of these alcohols and
dicarboxylic acids, such as, for example, the anhydrides,
acid chlorides and the like. The dicarboxylic acids must
be present in excess.
Where minor amounts of aliphatic polyalcohols with at
least 3 OH groups, especially glycerol, are also used, branched,
that is to say at least 3-functional, polyester-polycarboxylic
acids D and E are obtained. The use of the latter in the
reaction according to the invention is also a preferred form
of the invention. Branched polyester-polycarboxylic acids
D and E which are obtained if small amounts of polycarboxylic
acids, or their anhydrides, with at least 3 carboxyl groups
(such as, for example, trimellitic acid) are also present
``" ~.0909' ~
during the manufac-ture of the polyester~polycarboxylic acids,
are equally suitable for -the reaction according to the
invention.
However, it is also possible to employ brancned pol-y-
ester-polycarboxylic acids D and E, which are obtainable by
esterification of the terminal OH groups of long-chain poly-
ester-polyols, especial].y of polyester-diols, with poly-
carboxylic acids ~hich contain at least 3 -CO.OH groups,
such as, for example, trimellitic acid, or with corresponding
anhydrides.
The basic rules for the manufacture of the polyester-
polycarboxylic acids D and E used according to the present
invention in other respects entirely correspond to those
which have to be observed for the manufàcture of the "long-
chain dicarboxylic acids" employed according to British Patent
1,164,584, and which are described in detail in this British
patent. Further data on the basic principles of the manu-
facture of such long-chain, aliphatic polyester-polycarboxylic
acids are also to be found in a publication by Hans Batzer
et al. in "Die Angewandte Makromolekulare Chemie" 1973, page
349-412.
Examples of suitable polyester-polycarboxylic acids D
are those based on the following polyalcohols and polycarboxy-
lic acids:
11 mols of adipic acid - 10 mols of hexanediol
11 mols of sebacic acid - 10 mols of hexanediol
~ mols of decanedicarboxyllc acid - 4 mols of dodecanediol
~,0~309~'j
11 mols of dodecanedicarboxylic acid - 10 mols of butanediol
16 mols of adipic acid - 1~ mols of hexanediol
11 mols of dodecanedicarboxylic acid - 10 mols of hexanediol
11 mols of dodecanedicarboxylic acid - 10 mols of propane-
1,3-diol
11 mols of dodecanedicarboxylic acid - 10 mols of dodecane-
1,12-diol
5 mols of dodecanedicarboxylic acid - 4 mols of dodecane-1,12-dioî
11 mols of sebacic acid - 10 mols of butanediol
11 mols of sebacic acid - 10 mols of dodecanediol
5 mols of sebacic acid - 4 mols of dodecanediol
Examples of suitable polyester-polycarboxylic acids
are those based on the following polyalcohols and poly-
carboxylic acids:
11 mols of sebacic acid - lO mols of hexanediol
11 mols of adipic acid - 10 mols of hexanediol
11 mols of succinic acid - 10 mols of butanediol
17 mols of succinic acid - 14 mols of butanediol
21 mols of succinic acid - 20 mols of butanediol
22 mols of succinic acid - 21 mols of butanediol
Glycerol - succinic acid - butanediol (1:24:21)
Trimethylolpropane - succinic acid - butanediol (1:30:27)
Glycerol - succinic acid - butanediol (1:17:14)
Glycerol - succinic acid - butanediol (1:30:27)
31 mols of succinic acid - 30 mols of butanediol
16 mols of adipic acid - 15 mols of hexanediol
11 mols of sebacic acid - 10 mols of butanediol
1030~
11 mols of dodecanedicarboxylic acid - 10 mols of propanediol
7 mols of dodecanedicarboxylic acid - 6 mols of propanedlol
7 mols of dodecanedicarboxylic acid - 6 mols of butanediol
5 mols of sebacic acid - 5 mols of hexanediol
In principle, it is also possible~ according to the
invention, to use a procedure such that the reaction is
allowed to proceed in the presence of at least one further
aliphatic polyester-polycarboxylic acid, which although it is
similar to the polyester-polycarboxylic acids D and E differs
from these in respect of structure and molecular weight.
This results in the development of at least one further
(third) crystallite melting point in the end product.
As epoxide compounds containing two or more epoxide
groups it is possible to employ practically all the polyepoxy
compounds known to those skilled in the art, from publications
and patent specifications. According to the invention, one
or more different epoxide compounds can be reacted. Tri-
glycidyl isocyanurate and triglycidyl compounds which contain
one or more hydantoin groups and/or dihydrouracil groups,
especially epoxide compounds of the formula III
C~l CH
O ~3 ~ ~ - CH3 /
C~2 CH-C~12-N~N-CH2-C~-C~12-N~Y-CH2-CH--CH2 ~
~ 2 (III)
CH . .
I ~O
C~12 - . . . . .
iO'~ ~3
are particularly suitable.
In principle, the reaction according to the invention
can be carried out either in 1 stage or in several stages.
If the epoxide compounds used have at least 3 epoxide groups,
and polyester-dicarboxylic acids D,and E are employed, it is
possible, for example 5 to carry out the reaction in 1 stage,
that is to say to start from a reaction mixture ~hich contains
all the reactants simul-taneously. It is possible to pro-
ceed in exactly the same way (that is to say in 1 stage) if,
instead of the dicarboxylic acids, polyester-polycarboxylic
acids D and E which have at least 3 carboxyl groups are
employed. In the converse case~ that is to say when using
polyester-polycarboxylic acids D and E containing at least
~ carboxyl groups, and using diepoxy compounds, working in
1 stage is again possible and is the normal method of react on
for such cases.
If only diepoxide compounds and only polyester-
dicarboxylic,acids are employed, it is only possible to work
in one stage if an excess of epoxide compounds is used and at
'the same time a polycarboxylic acid anhydride is added.
In the multi-stage method, an adduct containing
epoxide groups is initially manufactured, in a first stage,
from the epoxide compounds and the polyester-polycarboxylic
acids D and/or E, preferably using 0.5 to 1 equivalent of
polyester-polycarboxylic acid per 2 equivalents of epoxide
compounds. In a second reac-tion stage, the crosslinking
is then carried out 9 by reaction of the adducts wi+h the
~o9o~
remainder of the polyester-polycarboxyllc acids D and/or E.
It is also possible to proceed by carrying out the cross-
linking in the second stage in the presence of customary
curing agents. It is also possible additionally to add
yet further`monomeric epoxide compounds and correspondingly
larger amounts of curing agents.
As customary curing agents ~or epoxide resins it is,
according to the invention, possible to employ all the sub-
stances which are described in the numerous publications and
patents relating to epoxide resins. Inter alia, the
following substances may be listed here: compounds with
amino groups, polyalcohols, polycarboxylic acids and their
anhydrides, acid amides, polyesters, phenol-formaldehyde con-
densates and amino-resin precondensates. Tertiary amines
and imidazoles may be mentioned as examples of suitable
accelerators.
The reaction according to the inven-tion is preferably
carried out in the melt. For this, preferably temperatures
of between 50 and 200C and reaction times of more than 1
hour and up to about 20 hours are required. In principle,
the reaction according to the invention can also be carried
out in solution.
Before or during the reaction according to the
invention, a blowing agent for the manufacture of ~oams can
also be added. -
' The crystalline, crosslinked plastic products are asa rule manufactured according to the invention with si,mul-
-- 10 --
~ 0~3~ ~
taneous shaping, to give castings, foamed articles, pressings,lacquer films, laminates, adhesive bonds, granules and the
like.
Of course, other customary additives, such as fillers,
reinforcing agents, mould release agents, agents to protect
against aging, flameproofing substances, dyestuffs or pigments,
can be added to the moulding compositions.
Suitable fillers or reinforcing agents are fibrous or
pulverulent inorganic or organic substances. Quartz powder,
aluminium oxide trihydrate, mica, aluminium powder, iron oxide,
ground dolomite, chalk powder, gypsum, slate powder, unburnt
kaolin (bolus), burnt kaolin, glass fibres, boron fibres and
asbestos fibres may be mentioned. A content of materials,
in the form of fibres and powders, which assist the heat conduct-
ivity can sometimes prove particularly advantageous~ Examples
of such materials are metals (for example aluminium powder),
carbon, such as carbon black and graphite in powder form, and
carbon fibres.
For the purpose of optimum and accelera-ted development
of the crystal structure of the polymers it is also advisable
to add nucleat~ing agents, such as phthalocyanines, carbon
black, ~-naphthoic acid or the like.
Because of their good properties, which have already
been mentioned above, and especially because of the out-
standing toughness over a wide temperature range, the epoxide
resins which can be manufactured according to the invention
are particularly suitable as constructional materials fortechn~l
-- 11 --
10909~>
applications It is surprising that the good properties
which are exhibited by these synthetic resins below the lower
crystallite melting point (Tml) are retained even at higher
temperatures, that is to say above Tml. In contrast,
after the crystallite melting point has been exceeded, the
synthetic resins of the state of the art, which have been
discussed above, change into the state of a valueless "limp"
rubber, which precludes their use as a constructional material. It
mustalso be emphasisedthattheadvantageous properties exhibited
above Tml by the products manufactured according to the
invention can be further improved by employing those polyester-
polycarboxylic acids E which result in a particularly high T~2.
A controlled variation of the toughness and the flexibility
can be realised in this way.
The epoxide resins which can be manufactured according
to the invention also exhibit a further special characteristic.
This is that, below the two crystallite melting points they
are distinguished by a particularly advantageous resilience of
about 70%. They are therefore suitable for the manufacture
of golf balls and the like.
One use of the crystalline, crosslinked epoxide resins
manufactured according to the invention is as a storage
material i~ so-called latent heat stores. As is kno~n,
those installations in which the phenomenon of the absorption
and re-release of latent heat during melting or crystallisation
of bodies or during boiling or condensation of liquids is
utilised for the storage of heat energy are termed latent
- 12 -
~.~90'3"~
heat accumulator3.
For latent heat accum~rs,in ~hkhthe heat of fusion
is stored, it has hitherto been primarily salt solutions and
salt mixtures which are used as the storage medium. How-
ever, when salt solutions and salt melts are used there are
always severe corrosion problems. For this reason, it is
predominant]y corrosion-resistant metal containers which are
used to contain the salts, but these containers are heavy and
conduct heat well; this is a disadvantage, quite apart from
the fact that such containers make the total installations
expensive. Furthermore, fractures and leaks of the salt
containers and pipes must always be expected, and this results
in extremely undesirable exudation of the solutions or melts.
The literature states that practically any desired
melting point can be obtained by appropriate choice of the
salt or by mixing different salts. In reality, however,
the situation is no-t quite so favourable, because if a salt
mixture ~hich does not correspond to a eutectic composition
is chosen, demixing phenomena always occur when the melt
solidifies. Only purely eutectic mixtures crystallise
in a constant composition. They are, therefore, for
practical purposes the only storage material used a-t the
present time. However, eutectic melts have a great
tendency to supercooling and must therefore be seeded. m is
in turn, however, has the consequence that here again demixing
phenomena gradually manifest themselves. It is not poss-
ihle to rea-iseS by continuous progression, any desired meit
- 13 -
109(1~
temperature by choosing eutec-tic salt mixtures, if only
because the number of eutectics is limited. Furthermore,
some eutectic melt temperatures can only be obtained by
choosing unusual expensive sal-ts, which a priori precludes
the practical realisation of such eutectics.
l~hen the crystalline, crosslinked epoxide resins
manufactured according to the invention are used as the storage
material in latent heat accumulators none of these disad-
vantageous properties and phenomena of the kno~n storage
materials arise and the melting point of the particular storage
material can be varied in a controlled manner. To this
extent, the present invention represents a very particular
enrichment of the art.
The crystalline, crosslinked epoxide resins manu-
factured according to the invention are of particular interest
. ~ .
as heat rectifiers, in which the enthalpy of fusion of the
polyester segment which has the lower melting point is used
~or storage, that is to say for heat insulation and subsequent
release of heat, and -the crystallites which have -the higher
melting point are used to maintain the mechanical strength.
The invention also relates to the crys-talline, cross-
linked epoxide resins which can be manufactured by the process
according to the invention, especially those resins which have
a lower crystallite melting point in the range from 20 to
~0C and an upper crystallite melting point in the range from
50 to 120C.
- 14 -
1090.'34~
Example 1
108 g (0.1 equivalent) of an acid polyester, prepared
from 11 mols of adipic acid and 10 mols of hexanediol and
155 g of an acid polyester prepared from 11 mols of sebacic
acid and 10 mols of hexanediol (both prepared by the melt
process) are warmed to 100C and mixed well with 22 g (0.2
equivalent) of triglycidyl isocyanurate and the mixture is
poured into Anticorodal moulds which have internal dimensions
of 150 x 150 x 1 mm, have been pre--treated with a silicone
mould-release agent and have been pre-warmed to 120C. The
mixture is cured for 16 hours at 140C. Crystalline,
tough mouldings with the following properties are obtained:
Tensile strength according to 2
VSM 77,101 (moulding No. 1)~ = 18 N/mm
Elongatior. at break = 520%
Crystallite melting point Tml~ = 27C
Crystallite melting point Tm2 = 50C
The mouldings are punched from -the 1 mm thick sheet using
a punching tool. The tensile -test also corresponds to
IS0 R 527
~ Determined with a differential scanning calorimeter (heat-
-ing rate = 10C/minute).
The sheet has two melting points which are ascribed to
the two polyesters used. Above the melting points, the
moulding is soft and rubbery-elastic.
~a~ple ?
a) 252 g (0.1 equivalen-t) of an adduct of 2.0 equivalents
1090~3'1~
of tetral~ydrophthalic acid di.glycidyl ester and 1.0 equivalent
of an aeid polyester obtained from 21 mols of succinic an-
hydride and 20 mols of butanediol are warmed, together with
16.0 g of hexahydropht;halic acid diglycidyl ester, to 120C
and mixed well with 108 g (0.1 equivalent) of an adipic acid -
hexanediol polyester (11:10) and 26.6 g of dodecenylsuccinic
anhydride (0.1 mol), the system is evacuated and the mixture
is poured into the moulds according to Example 1.
After curi.ng for 16 hours a-t 140C, crystalline, tough mould-
ings with the following characteristics are obtained:
Tml : 45C
Tm2 : 102C
b) When the same molar amounts of hexahydrophthalic
a~hydride are used in place of dodecenylsuccinic anhydride
and the composition and processing are otherwise identical to
those in Example 2a 5 mouldings with the following character-
isties are obtained:
Tml : 40C
Tm2 : 101C
Example_3
140 g (0.9 equivalent) ofan 11:10 sebacic acid/hexane-
diol polyester and 15.4 g (0.01 equivalent) of an acid (21:20)
suecinie aeid/butanediol polyester are warmed to 120C and
mixed well with 11 g (0.1 equivalent) of triglyeidyl isoeyan-
urate and the mixture is proeessed analogously to Example 1.
The resulting mouldings had the following characteristics:
Tml : 58CC
Tm2 : 100C.
- 16 -
~o~o9~;
In accordance with the relatively small amount of
succinic acid-butanediol polyester, the peak for the melting
point at 100C, in the DSC, was only small compared with that
of the sebacic acid polyester at 58C.
Example 4
0.1 equivalent of an acid polyester obtained from
11 mols of adipic acid and 10 rnols of hexanediol (equivalent
weight = 1,080), 0.1 equivalent of a branched acid polyester
obtained from 17 mols of succinic acid, 14 mols of butane-1,4-
diol and 1 mol of glycerol (equivalent weight = 1,460) and
0.2 equivalent of a hexahydrophthalic acid diglycidyl ester
with an epoxide equivalent weight of 160 are warmed and mixed
well. After adding 0.3% = 0.9 g of l-methylimidazole, -the
mixtureis evacuated and poured into aluminium tubes. After
heating to 140 for 16 hours, crystalline, crosslinked mould-
ings with the following characteristics are obtained:
Tml = 34 and 43 C (that is a two-stage melting point)
Tm2 = 85C.
Example 5
The procedure is as in Example 4, but with the differ-
ence that 0.2 equivalent of the triepoxide compound of the
formula III with an equivalent weight of 167 are employed in
place of hexahydrophthalic acid diglycidyl ester and that, in
addition, 40 g of aluminium powder and 0.6 g of ~-Cu phthalo
cyanine blue are added to the melt as a nucleating agen-t and
dyestuff respectively. Very tough, blue mouldings with
the follo~ring crystallite melting points are obtained:
- 17 -
~0
Tml = 38C
Tm2 ~ 76C
Example 6
When 3 g of a-naphthoic acid are used in place of
0,6 g of ~-Cu phthalocyanine blue and otherwlse the composition
and processing are identical to those in Exampl.e 5, mouldings
with the following characteristics are obtained:
Tml = 40C
Tm2 = 75C
Example ?
. Three layers of a glass mat are laid in an Anticorodalmould, which has internal dimensions of 8 x 200 x 200 mm and
has been treated with a silicone mould--release agent, and a.re
impregnated hot with the resin mixture described in Example 5,
but without aluminium powder and ~-Cu phthalocyanine blue.
After evacuating the system for a short time, the mixture is
cured at 140C for 16 hours. A soft, flexible but
extremely tough laminate which has the following characteristics
is obtained:
Tml = 37 and 48C (two-stage melting point)
Tm2 = 79C.
Example 8
~ .62 g (= 0.005 equivalent) of an adduct of 2 mols of
hexahydrophthalic acid diglycidyl ester and 1 mol of an acid
polyester obtained from 11 mols of sebacic acid and 10 mols of
~ hexanediol and 13.15 g (= 0.005 equivalent) of an adduct of
2.2 mols of -tetrahydrophthal~c acid diglycidyl est.er and l.Q mol
- 18 -
iO90~3~ti
of an acid polyester obtained from 22 mols of succi.nic
anhydride and 21 mols of butane-1,4-diol and also 1.54 g
(= 0.01 mol) of hexahydrophthalic anhydride are mixed well
whilst hot (about 130C) and, after adding 0.07 g of l-methyl-
imidazole, the mixture is poured into tubes and cured for
16 hours at 140C. The mouldings are very tough and have
the following crystallite mel-ting points:
Tml = 52C
Tm2 = 84C.
Example 9
8.32 g of an acid polyester ob-tained from 5 mols of
decanedicarboxylic acid and 4 mols of dodecanediol (equivalent
weight = 832) and 10.8 g (= 0.01 equivalent) of the adipic
acid - hexanediol polyester used in Example 1 and 3.~ g
(= 0.02 equivalent) of the triepoxide compound used in Example
5 are mixed well at 120C and, after adding 0.07 g of l-methyl-
imidazole, the system is evacuated and the mixture is poured
into an aluminium tube. Again, opaque, tough mouldings,
which have the following crystallite melting points, are
obtained:
Tml = 49C
Tm2 = 54C
xample 10
9.62 g (= 0.005 equivalent) of the sebacic acid -
hexanediol polyester adduct described in Example 8 and 1~.5 g
(= 0.005 equivalent) of the succinic acid - butanediol poly-
ester adduct, which is also described in Example 8, and also
~9 0~3~ ~ .
5.4 g (= 0.005 e~uivalent) of an (11:10) adi ic acid - hexane~
diol polyester and 0.8 g (=0~005 equivalent) o~ hexahydro-
phthalic anhydride and 0.09 g of l-methylimidazole are mixed
at 130C and the mixture is poured into an aluminium tube.
After curing for 16 hours at 140, mouldings with -the follo~ing
crystallite melting points are obtained:
Tml = 37
Tm2 = 52
Tm~ = 76
m e three melting points show that, even in crosslinked
polymers, each polyester aggregates on its o~m to form
crystallites.
- 20 -
