Title of Invention

STORAGE-STABLE ACCELERATOR SOLUTION

Abstract Accelerator solution suitable for forming a redox system with peroxides and having a high storage stability, consisting essentially of (a) more than 1.0 wt% of one or more reducing agents, at least one of them being selected from ascorbic acid and sodium formaldehyde sulphoxylate, (b) one or more metal salts, at least one of them being selected from the group consisting of transition metal salts, lithium salts, and magnesium salts, (c) one or more organic oxygen- containing solvents, (d) optionally one or more stabilisers, and (e) optionally water.
Full Text STORAGE-STABLE ACCELERATOR SOLUTION
The present invention relates to a storage-stable accelerator solution suitable
for forming a redox system with peroxides. The invention further relates to a
curing process employing this solution, and a polymerisation process using this
solution, and cured or polymerised items obtainable by these processes.
Redox systems can be applied for resin curing and polymerisation initiation.
Conventional redox systems comprise an oxidising agent (e.g. a peroxide), a
soluble transition metal ion as accelerator, and a reducing agent. The
accelerator serves to increase the activity of the oxidising agent at lower
temperatures and, consequently, to speed up the polymerisation and the curing
rate.
US 4,009,150 discloses a time-lapse free-radical polymerisable composition
comprising (i) a polymerisable compound selected from ethylenically
unsaturated monomers and reactive polymers, (ii) a peroxide initiator, (iii) a
soluble organic reducing agent, (iv) iron or copper chelate, and (v) excess
chelating agent, wherein the chelating agent is selected from (3-dicarbonyl
compounds having an enol content of at least 4% and a dicarbonyl angle of not
greater than 120° and [B-hydroxy nitrogen-heterocyclic fused aromatics in which
the hydroxyl group is attached to a carbon beta to the nitrogen in the adjacent
ring.
This composition is said to be reactive at room temperature. The total
composition therefore cannot be handled commercially as a preformed
composition, but must be handled as a multipackage composition and not
mixed together until it is ready for use.
EP 0 094 160 discloses a process for the polymerisation of vinyl chloride in
aqueous suspension with an organo-soluble free-radical-yielding initiator by
having a metal chelate complex present in the reaction zone and progressively
adding a reducing agent.

2
Disclosed metal complexes are Cu(dmgH)2, Ni(EDTA), Cu(bdm)2, Ni(TETA),
Cu(TACTD), Co(bipy)3CI3, and Co(phen)3CI3.
EP 1 211 263 discloses a metal promoter complex consisting of at least one
soluble metal salt and at least one chelating agent having less than 6 metal
coordinating groups. In a polymerisation process, this metal promoter complex
is added to a monomer mixture. Subsequently, oxidant and reductant are added
to said monomer mixture in separate streams.
US 4,446,246 discloses a method for curing a peroxide-curable ethylenically
unsaturated compound using a peroxide initiator, a Cu+ activator, and optionally
a reducing agent.
WO 05/047364 discloses a pre-accelerated polyester resin or vinyl ester resin
composition that is curable with liquid peroxide, containing an ascorbic acid
compound and a soluble iron-containing complex. The composition is free of
cobalt.
In all these prior art processes and compositions the peroxide, the reducing
agent, and the metal salt accelerator are added to the monomer mixture or the
curable resin as three separate streams. The reducing agent is not mixed with
the metal salt prior to use, because this would result in reduction and
precipitation of the metal.
It has now surprisingly been found that storage-stable accelerator solutions can
be prepared which contain both the reducing agent and the accelerator metal
salt.
The present invention relates to such an accelerator solution, which consists
essentially of:

3
a) more than 1.0 wt% of one or more reducing agents, at least one of them
being selected from ascorbic acid and sodium formaldehyde sulphoxylate,
b) one or more metal salts, at least one of them being selected from the group
consisting of transition metal salts, lithium salts, and magnesium salts,
c) one or more organic oxygen-containing solvents,
d) optionally one or more stabilisers, and
e) optionally water.
The fact that the accelerator solution according to the present invention
"consists essentially of the indicated components, means that the solution does
not contain any other compounds, except for trace amounts that have no
material effect on the performance of the accelerator solution. In particular, it
should be emphasized that the accelerator solution does not contain a
polymeric resin.
Due to the presence of the oxygen-containing solvent, the accelerator solution
has a storage stability of at least about 2 weeks. This means that after storage
at 20°C for at least 2 weeks, the accelerating activity - measured as the time to
peak (TTP) in minutes - has decreased by no more than 10%. Preferably, also
the peak exotherm, in °C (PE), has decreased by no more than 10%.
The peak exotherm is defined as the maximum temperature reached in a time-
temperature curve measured at ambient temperature (20°C), according to the
method outlined by the Society of Plastic Institute, and available from Akzo
Nobel Polymer Chemicals (standard method F/77.1). The time to peak is the
time, in minutes, required to reach this maximum temperature. According to this
method, 25 g of a mixture comprising 100 parts by weight of polyester resin, 2
parts by weight of peroxide, and 0.25 parts by weight of accelerator solution are
poured into a test tube and a thermocouple is placed through the enclosure at
the centre of the tube. The glass tube is then placed in an oil bath and

4
maintained at a specific test temperature and the time-temperature curve is
measured.
Preferably, the storage stability of the accelerator solution according to the
invention is at least 4 weeks, more preferably at least 6 weeks, and most
preferably at least 8 weeks.
Due to this storage stability, the solution containing both the metal salt
accelerator and the reducing agent can be handled commercially in one single
package. Further, with the use of this accelerator solution both the reducing
agent and the metal salt accelerator can be added as one stream during curing
and polymerisation initiation processes, which makes these processes simpler
and more cost-efficient.
With the accelerator solution according to the invention, crystal clear end
products may be produced. In addition, they can be made cobalt-free and
colourless.
The accelerator solution according to the invention comprises one or more
reducing agents, at least one of them being selected from ascorbic acid and
sodium formaldehyde sulphoxylate (SFS). Ascorbic acid, which term in this
specification includes L-ascorbic acid and D-isoascorbic acid, is the preferred
reducing agent.
Examples of reducing agents which can be present in addition to ascorbic acid
or SFS are reducing sugars like glucose and fructose, oxalic acid, phosphines,
phosphites, organic or inorganic nitrites, organic or inorganic sulphites, organic
or inorganic sulphides, mercaptanes, amines, and aldehydes. Also a mixture of
ascorbic acid and SFS, optionally in combination with other reducing agents,
may be used.
The reducing agent is present in the accelerator solution in an amount of more
than 1.0 wt%, preferably at least 2 wt%, and most preferably at least 5%. It is

5
preferably present in an amount of less than 30 wt%, more preferably less than
20 wt%, all based on the total weight of the accelerator solution. The term "more
than 1.0 wt%" does not include the value 1.0 wt%.
The accelerator solution further contains one or more metal salts, at least one of
them being selected from the group consisting of transition metal salts, lithium
salts, and magnesium salts. Preferred metal salts are copper, cobalt, iron,
nickel, tin, manganese, vanadium, lithium, and magnesium saits. More
preferred metal salts are copper, cobalt, iron, and vanadium salts. Due to the
toxicity of cobalt and vanadium, copper and iron salts are the most preferred
metal saits.
Combinations of metal salts - e.g. vanadium and copper salts, vanadium and
iron salts - can also be used.
The salt employed preferably is a halide, nitrate, sulphate, lactate, 2-ethyl
hexanoate, acetate, proprionate, butyrate, oxalate laurate, oleate, linoleate,
palmitate, stearate, acetyl acetonate, or naphthenate. More preferred salts are
halides, nitrates, sulphates, lactates, 2-ethyl hexanoates, and acetates.
Examples of such salts are Cu(ll) acetate, Cu(ll) sulphate, Cu(ll) 2-ethyl
hexanoate, Co(ll) acetate, Fe(ll) sulphate, Fe(lll) chloride, V(ll) 2-ethyl
hexanoate, and combinations thereof.
The metal salt(s) is/are present in the accelerator solution in a preferred total
amount of at least 0.01 wt%, more preferably at least 0.1 wt%. The metal salt(s)
is/are preferably present in a total amount of less than 10 wt%, more preferably
less than 5 wt%, and most preferably less than 2 wt%, calculated as salt(s) and
based on the total weight of the accelerator solution.
The organic oxygen-containing solvent is a solvent comprising at least one
oxygen atom and capable of forming a complex with the metal present in the
accelerator solution. The solvent preferably has a melting point of 0°C or less.

6
In general, the solvent will carry an aldehyde, ketone, ether, ester, alcohol,
phosphate, or carboxylic acid group.
Examples of suitable solvents are glycols such as ethylene glycol, glycerol,
diethylene glycol, dipropylene glycol, and polyethylene glycol; isobutanol;
pentanol; 1,2-dioximes, N-methyl pyrrolidinone, N-ethyl pyrrolidinone;
phosphorus-containing compounds such as diethyl phosphate, dibutyl
phosphate, tributyl phosphate, triethyl phosphate, dibutyl phosphite, and triethyl
phosphite; esters such as dibutyl maleate, dibutyl succinate, ethyi acetate, butyl
acetate, methyl acetoacetate, ethyl acetoacetate, mono- and diesters of
ketoglutaric acid, pyruvates, and esters of ascorbic acid such as ascorbic
palmitate; 1,3-diketones and aldehydes, in particular acetyl acetone, benzoyl
acetone, and dibenzoyl methane; mono- and diesters, more in particular diethyl
malonate and succinates; 1,2-diketones, in particular diacetyl and glyoxal; butyl
dioxytol (also known as diethylene glycol monobutyl ether, formula
nBuOCH2CH20CH2CH2OH), benzyl alcohol, and fatty alcohols.
Preferred solvents are triethyl phosphate, dibutyl phosphate, ethylene glycol,
diethylene glycol, polyethylene glycol, N-methyl pyrrolidone, ethyl acetate, and
butyl acetate.
A mixture of two or more of the aforementioned solvents may also be used.
The accelerator solution preferably comprises at least 50 wt%, more preferably
at least 70 wt%, and preferably less than 95 wt%, more preferably less than 90
wt% of solvent, all based on the total weight of the accelerator solution.
A stabiliser may be present in the accelerator solution according to the
invention. Suitable stabilisers are compounds that typically prevent
crystallisation of the metal salt(s) in the solution, for example tertiary amines
such as triethyl amine, triethanol amine, and dimethylamino ethanol;
polyamines such as 1,2-(dimethyl amine)ethane; secondary amines such as
diethanol amine (DETA) and diethyl amine; monoethanol amine; nicotinamide;

7
diethyl acetoacetamide; itaconic acid; monobutyl dihydrophosphite; and alkali
metal 2-ethyl hexanoates such as lithium 2-ethyl hexanoate, potassium 2-ethyl
hexanoate, sodium 2-ethyl hexanoate, barium 2-ethyl hexanoate, and cesium 2-
ethyl hexanoate.
The stabilisers may be added to the accelerator solution as such, or they may
be formed in situ. For example, alkali metal 2-ethyl hexanoates can be prepared
in situ in the accelerator solution, after addition of the alkali metal hydroxide and
2-ethyl hexanoic acid to the solution.
If one or more stabiliser(s) is/are present in the accelerator solution, their
amount preferably is at least 0.01 wt%, more preferably at least 0.1 wt%, and
preferably not more than 20 wt%, more preferably not more than 10 wt%, all
based on the total weight of the accelerator solution.
The accelerator solution according to the present invention may optionally
comprise water. If present, the water content of the solution preferably is at
least 0.01 wt% and more preferably at least 0.1 wt%. The water content is
preferably not more than 50 wt%, more preferably not more than 40 wt%, more
preferably not more than 20 wt%, even more preferably not more than 10 wt%,
and most preferably not more than 5 wt%, all based on the total weight of the
accelerator solution.
The accelerator solution according to the present invention can be prepared by
simply mixing the ingredients, optionally with intermediate heating and/or mixing
steps. There is no specific order of addition which has to be applied. For
example, first the one or more stabilisers may be added to the one or more
solvents, after which the metal salt(s) is/are added, followed by the reducing
agent(s). Another option is the addition of the one or more stabilisers to the one
or more solvents, after which the reducing agent(s) is/are added, followed by
the metal salt(s). Or the metal salt(s) is/are first added to the solvent(s),

8
followed by the addition of the stabiliser(s) and the reducing agent(s).
Alternatively, all ingredients can be added at the same time.
The accelerator solution according to the present invention can be used for
curing and polymerisation initiation with several classes of peroxides. This is
surprising, because until now the activation of peroxides other than
hydroperoxides and ketone peroxides - such as peroxy dicarbonates - could
not be achieved by metal complex accelerators at low temperatures.
Suitable peroxides to be used in combination with the accelerator solution of the
invention are hydroperoxides, ketone peroxides, peresters, peroxy carbonates,
perketals, diacyl peroxides, and peroxy dicarbonates.
It has also been found that, using a Co-containing accelerator according to the
invention in combination with ketone peroxides, only a minor amount of Co -
less than 0.01 wt% or even less than 0.001 wt% - is required to give a
satisfactory curing reactivity.
The accelerator solution can also be used as paint dryer in coating
compositions.
Curing
The invention further relates to a process for curing unsaturated polyester (UP)
and acrylate resins. In such curing processes, it is common practice to first
prepare the polyester or acrylate compound and, if desired, to combine this
compound with an ethylenically unsaturated monomeric compound. Such
mixtures are commercially available. The curing is generally started by adding
the accelerator solution according to the invention and the initiator (peroxide) to
the Dolvester or acrvlate resin.

9
As a result of the storage stability of the accelerator solution of the present
invention, it is also possible to pre-mix the resin and the accelerator solution
days or weeks before the addition of the peroxide and, consequently, the start
of the actual curing process. This allows commercial trade of a curable resin
composition which already contains an accelerator and a reducing agent. The
present invention therefore also relates to a composition comprising a curable
unsaturated polyester or a curable acrylate resin and the accelerator solution
according to the present invention.
When both the peroxide and the accelerator solution according to the invention
have been added to the curable resin, the resulting mixture is mixed and
dispersed. The curing process can be carried out at any temperature from -5°C
up to 250°C, depending on the initiator system, the accelerator system, the
compounds to adapt the curing rate, and the resin composition to be cured.
Preferably, it is carried out at ambient temperatures commonly used in
applications such as hand lay-up, spray-up, filament winding, resin transfer
moulding, coating (e.g. gel-coat and standard coatings), button production,
centrifugal casting, corrugated sheets or flat panels, relining systems, kitchen
sinks via pouring compounds, etc. However, it can also be used in SMC, BMC,
pultrusion techniques, and the like, for which temperatures up to 180°C, more
preferably up to 150CC, most preferably up to 100°C are used.
UP resins include so-called ortho resins, iso-resins, iso-npg resins, vinyl ester
resins, and dicyclopentadiene (DCPD) resins. Examples of such resins are
maleic, fumaric, allylic, vinylic, and epoxy-type materials.
Acrylate resins include acrylates, methacrylates, diacrylates and
dimethacrylates and oligomers thereof.
If desired, the UP resin or acrylate resin may be combined with one or more
ethylenically unsaturated reactive monomers. Preferred ethylenically

10
unsaturated reactive monomers include styrene and styrene derivatives such as
a-methyl styrene, vinyl toluene, indene, divinyl benzene, vinyl pyrrolidone, vinyl
siloxane, vinyl caprolactam, stilbene, but also diallyl phthalate, dibenzylidene
acetone, allyl benzene, methyl methacrylate, methylacrylate, (meth)acrylic acid,
diacrylates, dimethacrylates, acrylamides; vinyl acetate, triallyl cyanurate, triallyl
isocyanurate, allyl compounds which are used for optical application (such as
(di)ethylene glycol diallyl carbonate), and mixtures thereof.
The amount of ethylenically unsaturated monomer is preferably at least 0.1
wt%, based on the weight of the resin, more preferably at least 1 wt%, and most
preferably at least 5 wt%. The amount of ethylenically unsaturated monomer is
preferably not more than 50 wt%, more preferably not more than 40 wt%, and
most preferably not more than 35 wt%.
In this curing process, the accelerator solution is generally employed in a
conventional amount. Amounts of at least 0.01 wt%, preferably at least 0.1 wt%,
and not more than 5 wt%, preferably not more than 2 wt% of the accelerator
solution, based on the weight of the resin, are typically used.
Peroxides suitable for the curing of UP and acrylate resins include organic
peroxides, such as conventionally used ketone peroxides, peresters, and
peroxydicarbonates, but also peroxycarbonates, perketals, hydroperoxides and
diacyl peroxides. The skilled person will understand that these peroxides can be
combined with conventional additives, for instance phlegmatisers, such as
hydrophilic esters and hydrocarbon solvents.
The amount of peroxide to be used in the curing process is preferably at least 0.1
wt%, more preferably at least 0.5 wt%, and most preferably at least 1 wt%. The
amount of peroxide is preferably not more than 8 wt%, more preferably not more
than 5 wt%, most preferably not more than 2 wt%, all based on the weight of the
resin.

11
Other optional additives may be employed in the curing process according to
the invention, such as fillers, glass fibres, pigments, inhibitors, and promoters.
In the curing process of the present invention, typically the resin is first mixed
with the monomer. The accelerator composition can be added in several
different manners and may have been pre-mixed with the monomer or resin.
The peroxide formulation can be added directly to the mixture. However, it can
aiso be first mixed with the monomer or resin. Care is to be taken that the
peroxide formulation and the accelerator solution are not pre-mixed, since this
would be hazardous.
Polymerisation initiation
The accelerator solution according to the present invention can also be used to
accelerate the polymerisation initiation in redox polymerisation processes.
Such polymerisation processes may be carried out in the usual manner, for
example in bulk, suspension, emulsion, or solution.
The peroxide and the accelerator solution can be added at the start of the
polymerisation process, or they can be dosed partly or in their entirety during
the polymerisation process. It is also possible to add the peroxide at the start of
the polymerisation process, while the accelerator solution is added during the
said process, or vice versa.
The desired amounts of peroxide and accelerator solution vary depending on
the polymerisation temperature, the capacity for removing the heat of
polymerisation, the kind of monomer to be used, and the applied pressure.
Usually, from 0.001-10 wt% peroxide, based on the weight of the (co)polymer,
is employed. Preferably, from 0.001-5 wt% of peroxide is employed and most
preferably from 0.001-2 wt%. The ratio of peroxide to metal salt preferably
ranges from 0.2-100.

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The polymerisation temperature usually is 5° to 300°C, preferably 10° to 180°C.
In general, if it is below 5°C, the polymerisation time becomes too long.
However, when it exceeds 300°C, the radical is spent in the initial stage of the
polymerisation, making it difficult to attain a high conversion. In order to reduce
the amount of unreacted monomer, however, it is also possible to conduct the
polymerisation using a temperature profile, e.g., to perform the initial
polymerisation at below 100°C and then elevate the temperature above 100°C
to complete the polymerisation. These variations are all known to the man
skilled in the art, who will have no difficulty selecting the reaction conditions of
choice, depending on the particular polymerisation process and the specific
radical polymerisation initiator to be used.
Suitable monomers for polymerisation using the accelerator solution according
to the present invention are olefinic or ethylenically unsaturated monomers, for
example substituted or unsubstituted vinyl aromatic monomers, including
styrene, a-methyl styrene, p-methyl styrene, and halogenated styrenes; divinyl
benzene; ethylene; ethylenically unsaturated carboxylic acids and derivatives
thereof, such as (meth)acrylic acids, (meth)acrylic esters, such as 2-ethylhexyl
acrylate, 2-ethylhexyl methacrylate, and glycidyl methacrylate; ethylenically
unsaturated nitriles and amides, such as acrylonitrile, methacrylonitrile, and
acrylamide; substituted or unsubstituted ethylenically unsaturated monomers,
such as butadiene, isoprene, and chloroprene; vinyl esters, such as vinyl
acetate and vinyl propionate; ethylenically unsaturated dicarboxylic acids and
their derivatives including mono- and diesters, anhydrides, and imides, such as
maleic anhydride, citraconic anhydride, citraconic acid, itaconic acid, nadic
anhydride, maleic acid, fumaric acid, aryl, alkyl, and aralkyl citraconimides,
maleimides, biscitraconimides, and bismaleimides; vinyl halides, such as vinyl
chloride and vinylidene chloride; vinyl ethers, such as methyl vinyl ether and n-
butyl vinyl ether; olefins, such as isobutene and 4-methyl pentene; allyl

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compounds, such as (di)allyl esters, for example diallyl phthalates, (di)allyl
carbonates, and triallyl (iso)cyanurate.
During (co)polymerisation, the formulations may also contain the usual additives
and fillers. As examples of such additives may be mentioned: inhibitors of
oxidative, thermal, or ultraviolet degradation, lubricants, extender oils, pH
controlling substances, such as calcium carbonate, release agents, colourants,
reinforcing or non-reinforcing fillers such as silica, clay, chalk, carbon black, and
fibrous materials, such as glass fibres, plasticisers, diluents, chain transfer
agents, accelerators, and other types of peroxides. These additives may be
employed in the usual amounts.
EXAMPLES
In the examples below, the following resins and peroxides were used:

Paiatai® P6 Ortho Phthaiic Acid-based resin (OPA resin), ex D3M
Palatal® P51 Tetra Hydro Phthaiic Acid-based resin (THPA), ex DSM
ENOVA.Atlac Vinyl Ester-based resin (VE), ex DSM
Syn.6494-U2 Di Cyclo Pentadiene-based resin (DCPD), ex DSM,
MA 123 M50 MMA/Dimethacrylate resin, ex Akzo Nobel
Trigonox® 21 A commercial tert-butyl peroxy-2-ethyl hexanoate ex Akzo
Nobel
Trigonox® C A commercial tert-butyl peroxybenzoate ex Akzo Nobel
Trigonox® 117 A commercial tert-butyl peroxy-2-ethylhexyl carbonate ex
Akzo Nobel
Perkadox® 16 A commercial di(4-tert-butyl cyclohexyl) peroxy dicarbonate
ex Akzo Nobel
Perkadox® CH50 A commercial benzoyl peroxide ex Akzo Nobel

14
In the examples below, the curing of the unsaturated polyester resins was
analysed by the method of the Society of Plastic Institute (analysis method
F/77.1; available from Akzo Nobel Polymer Chemicals). This method involves
measuring of the peak exotherm, the time to peak, and the gel time.
According to this method, 25 g of a mixture comprising 100 parts of polyester
resin, 2 parts of peroxide, and 0.25 parts of accelerator solution were poured
into a test tube and a thermocouple was placed through the enclosure at the
centre of the tube. The glass tube was then placed in the oil bath maintained at
a specific test temperature and the time-temperature curve was measured.
From the curve the following parameters were calculated:
Gel time (Gt) = time in minutes elapsed between the start of the experiment and
5.6°C above the bath temperature.
Time to peak exotherm (TTP) = time elapsed between the start of the
experiment and the moment that the peak temperature is reached.
Peak exotherm (PE) = the maximum temperature which is reached.
Example 1
Accelerator solution A, according to the invention, was prepared by first mixing
the solvent and the stabiliser at ambient temperature. Then the metal salt was
added and the mixture was slowly heated to 80°C. At 80°C the reducing agent
was added and the total mixture was stirred for another 30 min at decreasing
temperature. The composition of the resulting solution is shown in Table 1.
Table 1

A (wt%)
solvent: di-ethylene glycol 84
stabiliser: nicotinamide 0.25
metal salt: Cu(ll) acetate 0.20
reducing agent: D-iso ascorbic acid 15.55

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The storage stability of this composition was tested by curing Palatal® P6 resin
with Trigonox® C at an initial temperature of 20°C, using the accelerator
solutions direct after preparation and after storage for 2, 4, and 8 weeks at 20°
or 40°C. Per 100 grams of resin, 2 grams of Trigonox® C and 0.25 gram
accelerator solution were used in these tests. Table 2 indicates the gel time
(Gt), Peak Exotherm (PE), and Time to Peak (TTP) measured.
Table 2

Storage
temperature (°C) Storage time
(weeks) Gt (min) TTP (min) PE (°C)
0 6.2 15.4 167
20 2 6.8 17.3 164
4 7.4 19.0 159
8 7.2 17.6 160
40 2 7.4 18.8 160
4 6.8 17.8 162
8 6.9 17.3 161
Table 2 shows that after 8 weeks of storage, the accelerator solution showed no
significant decrease in activity.
Example 2
The storage stability of a premix of a UP-resin with 1 wt% of accelerator A was
measured on pre-gellation in the NOURY® - Potlifetimer by means of a metal
ball which is moved upwards in a test tube by using a magnet. The lapse of time
between the addition of the accelerator to the resin and the moment the metal
ball cannot be moved anymore is called the pot life.
The results are shown in Table 3.

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Table 3

resin type pot life (hrs)
Palatal® P51 55
ENOVA.Atlac 90
Syn.6494-U2 124
MA 123 M50 >148
Example 3
In this experiment, three accelerator solutions were used:
- accelerator solution A (see Table 1)
- accelerator solution B, which only differs from solution A in that it additionally
contains 1 wt% of Cobalt(ll) acetate
- a commercial Co-containing solution comprising an oxygen-containing solvent
but no reducing agent (comparative solution C).
These solutions were tested for the curing of Palatal® P6 resin with Butanox®
M50 at initial temperatures of 20CC. Per 100 grams of resin, 2 grams of
peroxide were used in these tests. The amount of accelerator solution (per 100
grams resin) and the weight percentage of cobalt present in the curable
composition are indicated in Table 4. This Table further shows the gel time (Gt)
measured.
Table 4

solution amount used (gram) wt% cobalt Gt (min)
A 0.35 - 6.8
B 0.35 0.00084 5.4
C 0.35 0.0137 5.8
C 0.021 0.00082 100

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These results show that accelerator solutions according to the invention
(solutions A and B) provide a satisfactory curing rate, which is comparable with
that of a similar amount of a commercial solution.
The results further show that with the accelerator solutions according to the
invention less cobalt is required to obtain desirable results than when using the
commercial solution.
Example 4
Five different Cu-based accelerator solutions (D1-D5) were prepared (see Table
5; all in weight percentages) according to the procedure of Example 1. These
solutions were tested for the curing of Palatal® P6 resin with Trigonox® 21 and
Trigonox® 117 at initial temperatures of 20°C. Per 100 grams of resin, 2 grams
of peroxide and 0.5 gram of accelerator solution were used in these tests. Table
6 indicates the gel time (Gt), time to peak (TTP), and peak exotherm (PE)
measured.
Table 5

D1
70.0 D2 D3 D4 D5
solvent: di-ethylene glycol
75.0 80.0 70.0 70.0
stabilisers: monobutyl
dihydrophosphite 10.0 10.0 - 10.0 10.0
nicotinamide 5.0 5.0 5.0 5.0 5.0
di-ethanolamine 5.0 5.0 3.0 3.0
di-ethyl acetoamide - - - 2.0 2.0
metal salt: Cu(ll) acetate (2 H20) 1.0 1.0 1.0 1.0 1.0
Vanadium pentoxide - - - - 0.2
reducing agent: D-iso ascorbic acid 9.0 9.0 9.0 9.0 9.0

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Table 6

Accelerator solution peroxide Gt (min) TTP (min) PE (°C)
D1 Trigonox® 21 4.6 , 7.5 188
D2 Trigonox® 21 5.5 11.6 184
D3 Trigonox® 21 2.9 5.4 189
D4 Trigonox® 21 4.7 7.5 192
D5 Trigonox® 21 4.8 5.2 191
D1 Trigonox® 117 7.4 12.4 154
D2 Trigonox® 117 14.7 21.0 180
D3 Trigonox® 117 4.9 8.6 173
D4 Trigonox® 117 8.1 11.4 188
D5 Trigonox® 117 4.9 7.4 187
This table shows that the accelerator solutions according to the invention result
in good curing performances of both peresters and peroxy carbonates.
Example 5
Five different Fe-based accelerator solutions (D6-D10) were prepared (see
Table 7, all in weight percentages) according to the procedure of Example 1.
These solutions were tested for the curing of Palatal P6 resin with Trigonox® 21
and Trigonox® 117 at initial temperatures of 20°C. Per 100 grams of resin, 2
grams of peroxide and 1 gram accelerator solution were used in these tests.
Table 8 indicates the gel time (Gt), time to peak (TTP), and peak exotherm (PE)
measured.

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Table 7

D6 D7 D8 D9 D10
solvent: ethylene glycol 79.0 78.0 78.5 77.9 81.6
stabilisers: monobutyl
dihydrophosphite ~ 1 - ~ ™
nicotinamide - - - 1 1
di-ethanolamine - - 0.5 - 0.3
metal salt: Cu(il) acetate (2 H20) - - - 0.1 0.1
Fe(ll) sulphate (6 H20) 2.0 2.0 2.0 2.0 2.0
reducing agent: D-iso ascorbic acid 19.0 19.0 19.0 19.0 15.0
Table 8

Accelerator solution peroxide Gt (min) TTP (min) PE (°C)
D6 Trigonox®21 12.3 32.1 145
D7 Trigonox®21 18.9 44.4 139
D8 Trigonox® 21 9.6 23.4 163
D9 Trigonox® 21 4.9 7.3 190
D10 Trigonox® 21 4.9 7.2 194
D6 Trigonox® 117 10.5 29.4 140
D7 Trigonox® 117 17.9 44.0 121
D8 Trigonox® 117 8.2 20.9 163
D9 Trigonox®117 6.0 8.4 193
D10 Trigonox® 117 5.8 8.0 195
This table shows that the accelerator solutions according to the invention result
in good curing performances of both peresters and peroxy carbonates.

20
Example 6
Accelerator solution A (see Table 1) was tested for the curing of Palatal P6
resin with Perkadox® 16 at an initial temperature of 20°C. Per 100 grams of
resin, 2 grams of peroxide and 0.25 gram accelerator solution A were used. The
gel time of this system was 2.5 minutes, the time to peak 7.8 min, and the peak
exotherm 170°C.
Hence, the solution according to the invention is even suitable for accelerating
peroxy dicabonates.
Example 7
Accelerator solution A (see Table 1) was tested for the curing of Palatal P6
resin with Perkadox® CH50 at an initial temperature of 20°C. Per 100 grams of
resin, 2 grams of peroxide and 0.25 gram accelerator solution A were used. The
gel time of this system was 6.2 minutes, the time to peak 17.3 min, and the
peak exotherm 161 °C.
Hence, the solution according to the invention is aiso suitable for accelerating
diacyl peroxides.
Example 8
Accelerator solution A (see Table 1) was tested for the curing of acrylate resin
MA123 M-50 resin with Trigonox® C and Perkadox® 16 at an initial
temperature of 20°C. Per 100 grams of resin, 2 grams of peroxide were used in
these tests. The amount of accelerator solution (per 100 grams resin) is
indicated in Table 9. The results are shown in Table 9.

21
Table 9

peroxide Ace. Sol. A
(g/100g resin) Gt (min) TTP (min) PE (°C)
Trigonox® C
Perkadox® 16 0.5
0.25 7.5
2.2 26
22.4 99
141
These results show that the accelerator solution according to the invention is
also suitable for use in acrylate curing.
Example 9
Two different Cu-based accelerator solutions (D11-D12) were prepared (see
Table 10; all in weight percentages) according to the procedure of Example 1.
These solutions were tested for the curing of Palatal® P6 resin with Perkadox®
CH50 at initial temperatures of 20°C. Per 100 grams of resin, 3 grams of
peroxide and 2.2 gram of accelerator solution were used in these tests. Table
11 indicates the gel time (Gt), time to peak (TTP), and peak exotherm (PE)
measured.
Table 10

D11 D12
solvents: di-ethylene glycol 32.0 32.4
1 -methyl-2-pyrrolidinone 18.0 18.2
water 36.0 36.4
stabiliser: di-ethanolamine 1.3 1.4
metal salt: Cu(ll) acetate (2 H20) 0.4 0.6
reducing agent: D-iso ascorbic acid 12.3
Sodium formaldehyde su Iphoxylate 11

22
Table 11

Accelerator solution peroxide Gt (min) TTP (min) PE (°C)
D11
D12 Perkadox® CH50
Perkadox® CH50 8.8
3 11
21.2 161
78
This table shows that sodium formaldehyde sulphoxylate and ascorbic acid are
both suitable as reducing agent.

23
CLAIMS
1. Accelerator solution suitable for forming a redox system with peroxides,
consisting essentially of:
a) more than 1.0 wt% of one or more reducing agents, at least one of them
being selected from ascorbic acid and sodium formaldehyde
sulphoxylate,
b) one or more metal salts, at least one of them being selected from the
group consisting of transition metal salts, lithium salts, and magnesium
salts,
c) one or more organic oxygen-containing solvents,
d) optionally one or more stabilisers, and
e) optionally water.

2. Accelerator solution according to claim 1 wherein the solvent is selected
from the group consisting of ethylene giycoi, di-ethyiene glycoi,
polyethylene glycol, triethyl phosphate, dibutyl phosphate, N-methyl
pyrrolidone, butyl acetate, ethyl acetate, water, and mixtures thereof.
3. Accelerator solution according to claim 1 or 2 wherein the stabiliser is
selected from the group consisting of di-ethanol amine, nicotinamide, alkali
metal 2-ethyl hexanoates, diethyl acetoacetamide, itaconic acid, diethyl
amine, monobutyl dihydrophosphite, and mixtures thereof.
4. Accelerator solution according to any one of the preceding claims wherein
the metal salts are selected from the group consisting of copper salts,
cobalt salts, iron salts, vanadium salts, and combinations thereof.
5. Accelerator solution according to claim 4 wherein the metal salt is selected
from the group consisting of Cu(ll) acetate, Cu(ll) sulphate, Cu(ll) 2-ethyl

24
hexanoate, Co(II) acetate, Fe(ll) sulphate, Fe(lll) chloride, V(ll) 2-ethyl
hexanoate, and combinations thereof.
6. Process for curing an unsaturated polyester or an acrylate resin wherein
the accelerator solution according to any one of claims 1-5 and a peroxide
are added to the unsaturated polyester or acrylate resin.
7. Redox polymerisation process wherein a peroxide and the accelerator
solution according to any one of claims 1-5 are used.
8. Cured or polymerised items obtainable by the process of claim 6 or 7.
9. Use of the accelerator solution according to claims 1-5 as paint dryer in
coating compositions.
10. Accelerator solution according io any one of claims 1-5 consisting
essentially of:

a) 2-30 wt% of one or more reducing agents, at least one of them being
selected from ascorbic acid and sodium formaldehyde sulphoxylate,
b) 0.01-10 wt% of one or more metal salts, at least one of them being
selected from the group consisting of transition metal salts, lithium salts,
and magnesium salts,
c) 50-95 wt% of one or more organic oxygen-containing solvents,
d) 0-20 wt% of one or more stabilisers, and
e) 0-10 wt% water,
up to a total of 100 wt%.

Accelerator solution suitable for forming a redox system with peroxides and having a high storage stability, consisting essentially of (a) more than 1.0 wt% of one or more reducing agents, at least one of them being selected from ascorbic acid
and sodium formaldehyde sulphoxylate, (b) one or more metal salts, at least one of them being selected from the group consisting
of transition metal salts, lithium salts, and magnesium salts, (c) one or more organic oxygen- containing solvents, (d) optionally one
or more stabilisers, and (e) optionally water.

Documents:

05072-kolnp-2007-abstract.pdf

05072-kolnp-2007-claims.pdf

05072-kolnp-2007-correspondence others.pdf

05072-kolnp-2007-description complete.pdf

05072-kolnp-2007-form 1.pdf

05072-kolnp-2007-form 3.pdf

05072-kolnp-2007-form 5.pdf

05072-kolnp-2007-international publication.pdf

05072-kolnp-2007-international search report.pdf

05072-kolnp-2007-pct priority document notification.pdf

05072-kolnp-2007-pct request form.pdf

5072-KOLNP-2007-ABSTRACT 1.1.pdf

5072-KOLNP-2007-AMANDED CLAIMS.pdf

5072-KOLNP-2007-ASSIGNMENT 1.1.pdf

5072-KOLNP-2007-ASSIGNMENT.pdf

5072-KOLNP-2007-CORRESPONDENCE OTHERS 1.1.pdf

5072-KOLNP-2007-CORRESPONDENCE.pdf

5072-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

5072-KOLNP-2007-EXAMINATION REPORT.pdf

5072-KOLNP-2007-FORM 1-1.1.pdf

5072-KOLNP-2007-FORM 13 1.1.pdf

5072-KOLNP-2007-FORM 13.pdf

5072-KOLNP-2007-FORM 18 1.1.pdf

5072-kolnp-2007-form 18.pdf

5072-KOLNP-2007-FORM 2.pdf

5072-KOLNP-2007-FORM 26.pdf

5072-KOLNP-2007-FORM 3-1.1.pdf

5072-KOLNP-2007-FORM 3-1.2.pdf

5072-KOLNP-2007-FORM 3.pdf

5072-KOLNP-2007-FORM 5.pdf

5072-KOLNP-2007-GRANTED-ABSTRACT.pdf

5072-KOLNP-2007-GRANTED-CLAIMS.pdf

5072-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

5072-KOLNP-2007-GRANTED-FORM 1.pdf

5072-KOLNP-2007-GRANTED-FORM 2.pdf

5072-KOLNP-2007-GRANTED-SPECIFICATION.pdf

5072-KOLNP-2007-OTHERS 1.1.pdf

5072-KOLNP-2007-OTHERS.pdf

5072-KOLNP-2007-PA.pdf

5072-KOLNP-2007-PETITION UNDER RULE 137-1.1.pdf

5072-KOLNP-2007-PETITION UNDER RULE 137.pdf

5072-KOLNP-2007-REPLY TO EXAMINATION REPORT 1.1.pdf

5072-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf


Patent Number 251953
Indian Patent Application Number 5072/KOLNP/2007
PG Journal Number 16/2012
Publication Date 20-Apr-2012
Grant Date 18-Apr-2012
Date of Filing 28-Dec-2007
Name of Patentee AKZO NOBEL N.V.
Applicant Address VELPERWEG 76 NL-6824 BM, ARNHEM
Inventors:
# Inventor's Name Inventor's Address
1 KOERS FREDERIK WILLEM KAREL SETTERSHOF 9, NL-7214 BZ EPSE
2 BOVENKAMP-BOUWMAN VAN DE ANNA GERDINE APPELSESTRAAT 12, NL-3862 PH NIJKERK
PCT International Classification Number C08F 4/40
PCT International Application Number PCT/EP2006/062563
PCT International Filing date 2006-05-24
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 05104682.9 2005-05-31 EUROPEAN UNION
2 60/693786 2005-06-27 EUROPEAN UNION