This invention relates to aqueous polymer dispersions, the preparation
thereof and to compositions containing them.
It is an object of the present invention to provide aqueous polymer
dispersions which are particularly suitable for use as binder components of curable
aqueous surface coating compositions.
It is particularly an object of the invention to provide aqueous polymer
dispersions useful for the manufacture of radiation and/or heat curable aqueous
coating compositions such as paints, varnishes, lacquers, and inks (including overprint
varnishes) for application to substrates such as plastics, concrete, wood and paper.
The compositions are especially suitable for application to wood as radiation curable
According to a first embodiment of the invention, therefore, there
is provided an aqueous polymer dispersion containing polymer particles formed of
at least two polymers, the polymer particles of the dispersion having a minimum
film-forming temperature below 100°C, for example below 60°C, and being formed of
two different polymers namely polymer A having a glass transition temperature (TgA)
of not more than 10°C, preferably from -70 to 10°C and especially from -35 to 5°C,
and forming from 5 to 65% by weight of the total polymer system ; and polymer B
having a glass transition temperature (TgB) of more than 25°C, preferably
in the range of more than 25 to 150°C and especially from 60 to 130°C, and forming
from 5 to 65% by weight of the total polymer system ; together with a multifunctional
material (C) present in an amount of from 5 to 70% by weight of the total polymer
system ; said polymers A and B and said multifunctional material (C) adding up to
100% by weight.
The term "multifunctional material" as used herein is intended to
refer to a monomer or other organic material having at least two ethylenically unsaturated
groups which can each, separately, take part in a free radical initiated addition
copolymerization reaction. The reacting of these unsaturated groups is not necessarily
the same ; thus they can be of the same chemical nature (e.g. they may be (meth)acrylate
groups) or may be of different chemical nature (e.g. may be a more reactive (meth)acrylate
group and a less reactive allylic group).
In order to render the composition heat or radiation curable it may
also contain, suitably in an amount of up to 5%, preferably 1 to 2,5%, by weight
of the total polymer system, an appropriate initiator system which, if not water-soluble,
may be emulsified in the water of the emulsion or may be grafted onto a latex polymer.
The glass transition temperatures of the polymers of the dispersion
may be calculated using the Fox equation [T.G. Fox, Bull. Am. Physics Soc., Vol.
1 (3), page 123 (1956)] and may, in practice, be measured by programmed differential
The polymers (A) and (B) may be prepared by a multistage polymerization
process or by blending of latices of the individually formed polymers. When prepared
by successive emulsion polymerization stages, the polymer produced in the first
stage will be referred to as the "first polymer", and that in the second stage as
the "second" polymer. The first stage polymer may comprise either of polymers A
or B as may the second stage polymer provided that both individual polymers are
present. Each polymerization stage leading to the formation of a particular polymer
may in itself comprise one or more polymerization steps, provided that each step
produces polymer having the same Tg. Thus, for example, when using conventional
seeding procedures, the first polymer may be produced by a first step producing
such polymer followed by a second step, using the same monomer composition, to provide
Each of the polymers making up the aqueous dispersion according to
the invention is prepared by polymerization of at least one ethylenically unsaturated
monomer, using a monomer composition which makes it possible to attain the desired
glass transition temperature. Ethylenically unsaturated monomers which can be used
include, for example, esters of acrylic acid or methacrylic acid, such as methyl
acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate
and n-butyl methacrylate ; and aromatic vinyl monomers such as styrene and its derivatives,
for example alpha-methyl styrene, vinyl toluene and tert-butyl styrene. The monomers
forming polymer (A) may be identical to or different from those forming polymer
(B). Particular preference is given to using butyl acrylate, methyl methacrylate
Each polymer making up the aqueous dispersion according to the invention
may optionally comprise up to 10 parts by weight of at least one water-soluble comonomer
which is copolymerizable with the ethylenically unsaturated monomers, per 100 parts
by weight of the said monomers. As water-soluble comonomers which can be used it
is possible to mention, in particular, acrylic acid, methacrylic acid, acrylamide,
methacrylamide, N-methylol acrylamide and N-methylol methacrylamide.
Similarly, each constituent polymer may contain up to 5 parts by weight,
per 100 parts by weight of that monomer, one at least crosslinking monomer. Typically,
these monomers crosslink during polymer formation without requirement of subsequent
drying or other curing techniques. It is possible to mention, in particular, ethylene
glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butylene glycol diacrylate
and divinyl benzene.
Similarly, each constituent polymer may contain up to 15 parts by
weight, per 100 parts by weight of that monomer, one at least functional copolymerizable
monomer, not included in the previous range of water soluble monomers, able with
a specific functional group to improve film properties for instance such as adhesion
or crosslinkable and grafting ability. As functional groups and related monomers
able to improve adhesion on substrates, it is possible to mention, in particular,
amine group such as oxazolidine groups in for example, oxazolidinylethyl methacrylate
and acetoacetyl group in for example acetoacetoxyethyl methacrylate.
As functional groups and related monomers able to improve further
crosslinkable and grafting ability, it is possible to mention, in particular, hydroxyl
group in for example hydroxyl ethyl methacrylate, unsaturated group in for example
dicyclopentadienyl methacrylate, acetoacetyl group in for example acetoacetoxyethyl
methacrylate, amine group in for instance N-(iso-butoxymethyl)acrylamide and 2-tert
butylamino ethyl methacrylate. Grafting and crosslinking reactions can take place
in latex, during latex coalescence or film ageing. Specific conditions such as temperature,
UV curing, pH, external reagents or catalyst may be required. Specific reagents
such as isocyanate, epoxy resins, carbodiimide may be added after synthesis.
Similarly, each constituent polymer may contain grafted photoinitiator
group. This grafted photoinitiator group may be obtained for example in using up
to 10 parts by weight parts one at least benzophenone functionalised monomer such
as UVECRYL® P 36 (Red Cure Specialities S.A., Anderlecht, Belgium).
In addition, it is possible that one at least of these three types
of monomers (water-soluble, functional and crosslinking) and photoinitiator group
is not incorporated uniformly into one at least of the constituent polymers but
added over a limited period of time during the polymerisation of monomers of one
step in an appropriately higher concentration (e.g. up to 90%). This process is
known as "shot process".
The minimum film-forming temperature of the polymer particles as a
whole is less than 100°C. for example below 60°C. The minimum film-forming transition
(MFFT or MFT) may be defined as the minimum temperature at which the particles of
a polymer dispersion coalesce to form a continuous, crack free film.
The polymer dispersion preferably has a particle size of from 50 to
Methods of measuring and controlling the average particle size are
well known in the art, for example as described by E.A. Collins, 18th Annual Short
Course (June 1987) of the Institute of Polymer Emulsion, Lehigh University (Pennsylvania)
; by E.A. Collins, J.A. Davidson and C.A. Daniels, J. Paint Technology
47, 35 (1975) or using the operating principles of the AutoSizer® Lo-C
apparatus from Malvern Instruments.
As noted above, aqueous polymer dispersions in accordance with the
invention may be prepared by a multi-stage polymerization process using, in each
stage, a combination of monomers adapted to give the desired Tg characteristics
to the polymer produced. It is often convenient to carry out the first polymerization
steps in two steps, i.e. a seed polymer-producing step followed by a further polymerization
The polymerization can be carried out in the presence of up to approximately
1 part by weight, per 100 parts by weight of the monomers, of at least one chain
transfer agent, in order to regulate the number-average molecular weight of the
resulting polymer. Examples of compounds which can be used as chain transfer agents
include mercaptocarboxylic acids and mercaptoalcohols having from 2 to 8 carbon
atoms such as mercaptoacetic acid, 2-mercaptobenzoic acid, 2-mercaptoethanol and
3-mercapto-2-butanol and alkyl or alkylaryl thiols such as butanethiol, dodecylmercaptan
and 2-methyl-5-tertio butyl thiophenol.
The ethylenically unsaturated monomers constituting each polymer of
the dispersion may be emulsified by means of at least one anionic or nonionic surfactant,
or may simply be introduced into a reactor in the form of a homogeneous mixture
of monomers. In the latter case, an aqueous solution of one or more surfactants
may be added simultaneously. It is preferable to use a combination of nonionic surfactant
and anionic surfactant in order to prepare emulsions. Examples of nonionic surfactants
include polyglucosides such as alkylpolyglucoside, polyethers such as condensates
of ethylene oxide and propylene oxide, alkyl and alkylaryl ethers and thioethers
of polyethylene glycols and polypropylene glycols, alkylphenoxypoly(ethylenoxy)ethanols,
polyoxyalkylene derivatives of partial esters of long-chain fatty acids such as
lauric, myristic, palmitic and oleic acids, condensates of ethylene oxide with higher
alkane thiols, ethylene oxide derivatives of long-chain carboxylic acids and of
alcohols, etc. These nonionic surfactants preferably contain approximately 5 to
100 ethylene oxide units per molecule and, more preferably, approximately 20 to
50 of such units. Examples of anionic surfactants which can be used, preferably
in combination with the nonionic surfactants, include high molecular weight sulphates
and sulphonates for example alkyl, aryl and alkylaryl sulphates and alkyl-, aryl-
and alkylarylsulphonates of sodium and potassium, such as sodium 2-ethylhexyl sulphate,
potassium 2-ethylhexyl sulphate, sodium nonyl sulphate, sodium undecyl sulphate,
sodium tridecyl sulphate, sodium pentadecyl sulphate, sodium lauryl sulphate, sodium
methylbenzenesulphonate, potassium methylbenzenesulphonate, potassium toluenesulphonate
and sodium xylenesulphonate, the sulphonated derivatives of the nonionic surfactants
listed above ; the salt of phosphonic acid esters of nonionic surfactants listed
above ; dialkyl esters of alkali metal salts of sulphosuccinic acid, such as sodium
diamylsulphosuccinate ; and condensation products of formaldehyde/naphthalenesulphonic
acid. The total quantity of surfactants used in the emulsion polymerization process
varies from approximately 2 to 20% by weight, preferably approximately from 4 to
12% by weight, of the monomeric components. The weight ratio of anionic surfactant
to nonionic surfactant should be between 0.01 and 1 approximately, preferably between
approximately 0.05 and 0.5. The quantity of water used in the reaction medium is,
in general, determined by the solids content desired in the aqueous dispersion according
to the invention, which is generally between approximately 40% and 70%, preferably
between 45 and 60% by weight.
The monomeric components of the dispersion are polymerized by means
of effective quantities, preferably between 0.1 and 2%, approximately, by weight
of the total charge of monomers, of at least one conventional free-radical initiator.
Such an initiator is preferably substantially soluble in water. Such initiators
comprise inorganic peroxides such as hydrogen peroxide and persulfate salts, organic
peroxides such as tertio-butyl hydroperoxide, azo compounds such as 2,2'-azobis
(2-amidinopropane)dihydrochloride and 4,4'-azobis (4-cyanopentanoic acid), and redox
system such as for example combinations of persulfate salt and alkali metal bisulphite.
The polymerization temperature required to produce the aqueous polymers
in each of the steps of the process is generally within a range from approximately
40 to 95°C - preferably from approximately 55 to 85°C - depending on the time envisaged
for the polymerization. The polymerization time is generally from approximately
45 minutes to 6 hours for each of the two steps, this time increases as the polymerization
In order to attain a final degree of conversion in the polymerization
reaction of 100%, it may be desirable to follow the final step by cooking the aqueous
polymer emulsion for approximately 30 to 90 minutes at a temperature which is higher,
preferably by at least 9°C, than the polymerization temperature.
A complementary improvement of steps consists in the treatment of
the aqueous polymer emulsion, after the final step or, if appropriate, after the
cooking step, by means of a free-radical initiation system which has a short half-life
at the temperature under consideration, in order to attain an overall degree of
conversion which is close to 100% and/or a residual monomer content which does not
exceed approximately 50 ppm. As examples of free-radical initiator systems it is
possible to mention organic and inorganic peroxides such as tert-butyl hydroperoxide,
butyl peroxide, hydrogen peroxide or alkali metal persulphates, in combination with
a reducing agent such as sodium formaldehyde-sulphoxylate, ascorbic acid, Mohr's
salt, etc. Such a treatment may be carried out at temperatures from 40°C to 90°C,
approximately, its duration depending on the chosen temperature and being preferably
between 15 minutes and 3 hours, approximately.
If the latex prepared in conformity with the present invention appears
too acid for the formulation of paints, it may be desirable to adjust its pH to
a value of greater than 6, for example by means of any alkaline substance such as
hydroxide of sodium, potassium or ammonium ; or an organic amine such as triethanolamine.
Seeded polymerization is preferred for the first stage of the polymerization.
Where the polymer dispersed is produced by blending two pre-formed
dispersions, each dispersion may be prepared by emulsion polymerization using the
general technique, ingredients and auxiliary agents discussed above for a multi-stage
The multi-functional material C, may or may not be emulsified in the
water of the polymer dispersion. When so emulsified, it may be emulsified with the
aid of surfactants as discussed above for the use in an emulsion polymerisation
A wide variety of multi-functional materials may be employed. Typical
examples include :
1. Epoxy (meth)acrylates.
2. Urethane (meth)acrylates.
3. Multi-functional (meth)acrylate monomers.
4. Amine-(meth)acrylate adducts.
Epoxy (meth)acrylates are those products formed by the reaction of
(meth)acrylic acid with an epoxy(glycidyl) functional component e.g. aliphatic and
aromatic containing epoxy resins, epoxidised oils, acrylic polymers and acrylic
grafted polymers in which the acrylic component contains pendent epoxy groups. Some
of the (meth)acrylic acid may be replaced by other acids, both ethylenically unsaturated
and saturated, so as to impart specific properties e.g. aliphatic acids, fatty acids
and aromatic acids.
These products may alternatively be prepared by the reaction of a
carboxylic acid functional component (e.g. polyesters and acrylic polymers) with
a second component containing both epoxy groups and ethylenic unsaturation e.g.
Urethane (meth)acrylates are those products formed by the reaction
of an isocyanate containing component with a hydroxyl containing component. At least
one of these components must contain ethylenic unsaturation. Examples of isocyanate
functional components are hexamethylene diisocyanate, isophorone diisocyanate, isocyanate
functional acrylic polymers and polyurethanes, reaction products of hydroxyl functional
components (e.g. poly-ethylene glycol, poly-propylene glycol and di-, tri- and etc-hydroxy
aliphatic alcohols (e.g. glycerol and trimethylolpropane) and their ethoxylated,
propoxylated and polycaprolactone analogs) with di-, tri- and etc-isocyanates (e.g.
hexamethylene diisocyanate, isophorone diisocyanate and TDI). Examples of hydroxy
containing ethylenically unsaturated components are hydroxyethyl (meth)acrylate
and its ethoxylated, propoxylated and polycaprolactone analogs.
Multi-functional (meth)acrylate monomers are (meth)acrylic acid esters
of di-, tri- and etc-hydroxyl alcohols (e.g. poly-ethylene glycol, poly-propylene
glycol, aliphatic diols, neopentyl glycol, ethoxylated bisphenol A, trimethylolpropane,
pentaerythritol, glycerol, di-trimethylolpropane, hydroxyl functional polyesters,
dipentaerythritol and the ethoxylated, propoxylated and polycaprolactone analogs
of all the above.
Amine-(meth)acrylate adducts are those products prepared by the partial
"Michael Type Addition" of primary and secondary amines to ethylenic unsaturation
i.e. the double bond of (meth)acrylate containing compounds. Of particular interest
here are the multi-functional (meth)acrylate monomers as mentioned above. Examples
of amine-acrylate adducts are diethylamine modified trimethylolpropane triacrylate
and ethanolamine modified ethoxylated trimethylolpropane triacrylate.
All of the above listed acrylates and methacrylates may incorporate
specific hydrophilic components to facilitate their being dissolved, emulsified
or dispersed in an aqueous phase. Examples are the addition of secondary amines,
phosphoric acid and anhydrides (e.g. succinic anhydride, phthalic anhydride and
tetrahydrophthalic anhydride). The resulting tertiary amines and pendent carboxylic
acid groups are then neutralised. Another hydrophilic group of particular interest
is poly-ethylene glycol.
A variety of photoinitiators or thermal initiators may be employed.
The photoinitiator may be added to the composition from about 0.1% by weight of
total nonvolatiles to about 5.0% by weight of total nonvolatiles and more preferably
from about 1.0% by weight of total nonvolatiles to about 2.5% by weight of total
nonvolatiles. Useful photoinitiators include cleavage-type initiators, halogenated
polynuclear ketones, such as chlorosulfonated benzanthrones, chlorosulfonated fluorenones,
haloalkylated benzanthrones, and haloalkylated fluorenones as disclosed in US-A-3,827,957
and US-A-3,827,959 ; benzoin, its ethers, such as methyl ether, ethyl ether, isopropyl
ether, butyl ether, octyl ether and the like ; carbonyl compounds such as diacetyl,
benzil and the like ; sulfur compounds such as diphenyl sulfide, dithiocarbamate
and the like ; a chloromethyl naphthalene and anthracene. Other useful photoinitiators
include alkylphenones and benzophenones as disclosed in US-A-3,759,807. Photoinitiators
suitable for pigmented coatings are suggested in US-A-3,915,824 and US-A-3,847,771.
Of particular interest for titanium dioxide pigmented formulations are the phosphine
oxides e.g. 2,4,6-(trimethylbenzoyl)diphenylphosphine oxide.
The composition may contain a thermal initiator if the coating will
be cured by heat or a catalyst if the coating will be cured by auto-oxidation. The
thermal initiator is added to the composition from about 0.5% by weight of total
nonvolatiles to about 2% by weight of total nonvolatiles. Useful thermal initiators
include azo compounds, such as azobisisobutyronitrile and the like ; organic peroxides,
such as ketone peroxides, hydroperoxides, alkyl peroxides, acryl peroxides, peroxy
esters and the like ; and inorganic peroxides, such as ammonium persulphate, potassium
persulphate, hydrogen peroxide and the like. Useful catalysts for auto-oxidative
cure include the salts of cobalt, such as cobalt acetate, cobalt naphthenate and
The present invention further provides a paint comprising an aqueous
polymer emulsion as defined described above.
The formulation method employed may be any one of those known in the
art of formulating latex paints. The aqueous paints according to the invention comprise
a mixture of colouring agents, e.g. pigment and latex. Powdered filler may also
Examples of powdered fillers include calcium carbonate, dolomite,
talc, mica, barium sulphate, lime and cement ; and example of pigments include titanium
oxide, carbon black, copper phthalocyanine, zinc oxide, iron oxides and chromium
In addition to the pigments and fillers the coating compositions of
the invention may contain other adjuvants such as dispersants [alkali metal silicates
(especially metasilicates), alkali metal polyphosphates and alkali metal salts of
organic polyacids (especially polyacrylates)] ; wetting agents, [e.g. nonionic surfactants
(for example polyether oxides)] ; rheology modifiers or thickeners (e.g. water-soluble
polymers modified by hydrophobic groups and hydroxyalkylcellulose derivatives) ;
antifoam agents ; biocides and anticorrosive agents.
The aqueous paints of the present invention may be applied to the
desired substrate by conventional means, for example brush, roller, spray-gun, etc.
The paints of the invention, after application to the substrate may,
where they contain a thermal initiator or external reagent, be cured by heating,
e.g. at a temperature of from 70 to 150°C for periods of from 3 min to 1 hour. When
the paints contain photosensitizer they may be cured by irradiation to UV light.
Useful radiation includes ionizing radiation, electron beam radiation and ultraviolet
radiation. Sources of ultraviolet radiation include sunlight, mercury lamp, carbon-char
lamp, xenon lamp and the like. Medium pressure mercury vapour lamps are preferred.
In order that the invention may be well understood the following Examples
are given by way of illustration only.
The blocking resistance of formulations was evaluated by a test method
based on ASTM blocking resistance test D4946.
The test solution is applied to sealed card using a 0.004 gap bar
applicator. The applied panels are conditioned at room temperature for 1 hr (early
blocking) and 24 hrs (later blocking) before testing.
Cured emulsion films are placed face-to-face and a pressure of about
127 g/M is applied. These paint films are either left at room temperature, or put
into an oven at 50°C, to make the test more stringent. After cooling, the blocked
panels are peeled apart. The degree of blocking is rated subjectively for tack or
seal using series of standard descriptive terms corresponding to numerical ASTM
Blocking resistance Numerical RatingsType of separationPerformance10no tackPerfect9trace tackexcellent8very slight tackvery good7very slight to slight tackgood to very good6slight tackgood5moderate tackfair4very tacky ; no sealpoor to fair35 to 25% sealpoor225 to 50% sealpoor150 to 75% sealvery poor075 to 100% sealvery poor
Note : Numerical values may differ from operator to operator but relative ranking
should be the same. The repeatability is estimated to be plus or minus one blocking
The chemical resistance of the films was tested by the xylene swab
test. Results are given in seconds before failure. The hardness of the films was
tested by the Koenig hardness test.
Ten polymer emulsions were prepared by multistage polymerization,
using two pre-emulsions having the following formulations :
Pre-emulsion 1 (Polymer A)
aqueous solution of 15% Sodium Dodecyl Sulphate
Pre-emulsion 2 (Polymer B)
aqueous solution of 15% Sodium Dodecyl Sulphate
[The sum of X1 and X2 is 100 parts].
The emulsion was prepared by the following general process.
1) An initial charge containing 41.4 parts water and 1.5 parts aqueous solution
of 15% Sodium Dodecyl Sulphate was put into a reactor and heated to 85°C.
2) Once the initial charge had reached 85°C, the initial initiator solution
(0.19 parts water and 0.05 parts sodium persulphate) was added and simultaneous
(a) pre-emulsion (feeding time : 1 hour), and
(b) the initiator solution (20 parts water and 0.4 parts sodium persulphate
; feeding time - 3 hours) were started maintaining a constant reactor temperature
of 85°C, +/-1°C.
3) At the end of the pre-emulsion 1 feed, the addition of the second feed of
pre-emulsion 2 (feeding time : 1 hour) was started still maintaining a reaction
temperature of 85°C.+/-1°C.
4) At the end of the second pre-emulsion feed, pipes and tanks are rinsed with
4.5 parts of water and the reaction was maintained for 1 hour at 85°C.
5) Then, the reactor was cooled to below 40°C before starting the neutralising
agent solution feed (feeding time 20 minutes) (1.18 parts water and 1.18 parts 25%
The characteristics of the emulsions were :
solid content : 43-44%
The following monomer compositions were employed to give polymers
of the desired Tg.
This emulsion was prepared by the steps of, at room temperature, putting
in a vessel in the following order, SR 351, BHT and Triton® GR-5M and then,
with vigorous mixing with a Silverson stirrer, adding, during 20 minutes, water
to give a creamy and stable emulsion.
The blocking resistance, Koenig hardness and chemical resistance and
cracking of the formulations were evaluated. The results are shown below. Compound
C is polyfunctional material introduced as an emulsion.
For testing clear films were drawn onto glass using ICI 0.004" bar
gap applicator. The cure schedule before the exposure to UV-light was 30 min at
room temperature followed by 30 min at 50°C. UV curing conditions were :
UV line speed : 3.25 m/min/Lamp
Lamp : Medium pressure Hg arc lamp.
The panels were left 24 hours at room temperature before testing (Blocking,
Koenig hardness, Xylene Swab).
Wäßrige Polymerdispersion, enthaltend aus mindestens zwei Polymeren gebildete
Polymerteilchen, die eine Mindestfilmbildungstemperatur unter 100°C aufweisen und
aus zwei verschiedenen Polymeren gebildet sind, nämlich Polymer A, das eine Glasübergangstemperatur
(TgA) von höchstens 10°C aufweist und 5 bis 65 Gew.-% des gesamten Polymersystems
ausmacht; und Polymer B, das eine Glasübergangstemperatur (TgB) von mehr
als 25°C aufweist und 5 bis 65 Gew.-% des gesamten Polymersystems ausmacht; zusammen
mit einem multifunktionellen Material (C), das in einer Menge von 5 bis 70 Gew.-%,
bezogen auf das gesamte Polymersystem, vorliegt, wobei sich die Gewichtsanteile
der Polymere A und B und des multifunktionellen Systems (C) zu 100 Gew.-% addieren
und das multifunktionelle Material (C) unter Epoxy(meth)acrylaten, Urethan(meth)acrylaten,
multifunktionellen (Meth)acrylatmonomeren und Amin-(Meth)acrylat-Addukten ausgewählt
Wäßrige Polymerdispersion nach Anspruch 1, bei der das Polymer A eine
Glasübergangstemperatur von -70 bis 10°C und das Polymer B eine Glasübergangstemperatur
im Bereich von mehr als 25 bis 150°C aufweist.
Wäßrige Polymerdispersion nach Anspruch 2, bei der das Polymer A eine
Glasübergangstemperatur von -35 bis 5°C und das Polymer B eine Glasübergangstemperatur
im Bereich von 60 bis 130°C aufweist.
Zusammensetzung nach einem der Ansprüche 1 bis 3, die außerdem auch noch
bis zu 5 Gew.-%, bezogen auf das Gewicht des gesamten Polymersystems, eines Initiatorsystems,
das die Zusammensetzung hitze- oder strahlungshärtbar macht, enthält.
Wäßrige Polymerdispersion nach einem der Ansprüche 1 bis 4, bei der die
Polymerteilchen der Dispersion eine Mindestfilmbildungstemperatur unter 60°C aufweisen.
Farbe, enthaltend eine Zusammensetzung nach einem der Ansprüche 1 bis 4.
An aqueous polymer dispersion containing polymer particles formed of at least
two polymers, the polymer particles of the dispersion having a minimum film-forming
temperature below 100°C and being formed of two different polymers namely polymer
A having a glass transition temperature (TgA) of not more than 10°C and
forming from 5 to 65% by weight of the total polymer system ; and polymer B having
a glass transition temperature (TgB) of more than 25°C and forming from
5 to 65% by weight of the total polymer system ; together with a multifunctional
material (C) present in an amount of from 5 to 70% by weight of the total polymer
system ; said polymers A et B and said multifunctional system (C) adding up to 100%
by weight ; said multifunctional material (C) being selected among epoxy (meth)acrylates,
urethane (meth)acrylates, multifunctional (meth)acrylate monomers and amine-(meth)acrylate
An aqueous polymer dispersion as claimed in claim 1, wherein polymer A has a
glass transition temperature from -70 to 10°C, and polymer B has a glass transition
temperature in the range of more than 25 to 150°C.
An aqueous polymer dispersion as claimed in claim 2, wherein polymer A has a
glass transition temperature from -35 to 5°C, and polymer B has a glass transition
temperature from 60 to 130°C.
A composition as claimed in anyone of claims 1 to 3, also containing up to 5%
by weight, based on the weight of the total polymer system, of an initiator system
to render the composition heat or radiation-curable.
An aqueous polymer dispersion as claimed in anyone of claims 1 to 4, wherein
the polymer particles of the dispersion have a minimum film-forming temperature
A paint comprising a composition as claimed in anyone of claims 1 to 4.
Dispersion polymère aqueuse contenant des particules polymères formées d'au
moins deux polymères, les particules polymères de la dispersion ayant une température
minimale de formation de films inférieure à 100°C et étant formées de deux polymères
différents, à savoir un polymère A ayant une température de transition vitreuse
(TvA) de pas plus de 10°C et constituant de 5 à 65% en poids du système
polymère total ; et un polymère B ayant une température de transition vitreuse (TvB)
de plus de 25°C et constituant de 5 à 65% en poids du système polymère total ; conjointement
avec une substance multifonctionnelle (C) présente en une quantité allant de 5 à
70% en poids du système polymère total ; lesdits polymères A et B et ledit système
multifonctionnel (C) constituant au total 100% en poids ; ladite substance multifonctionnelle
(C) étant choisie parmi des époxy (méth)acrylates, des uréthane-(méth)acrylates,
des monomères (méth)acrylates multifonctionnels et des produits d'addition amine-(méth)acrylate.
Dispersion polymère aqueuse selon la revendication 1, dans laquelle le polymère
A présente une température de transition vitreuse de -70 à 10°C et le polymère B
présente une température de transition vitreuse dans la gamme de plus de 25 à 150°C.
Dispersion polymère aqueuse selon la revendication 2, dans laquelle le polymère
A présente une température de transition vitreuse de -35 à 5°C et le polymère B
présente une température de transition vitreuse dans la gamme de 60 à 130°C.
Composition selon l'une quelconque des revendications 1 à 3, contenant également
jusqu'à 5% en poids, par rapport au poids du système polymère total, d'un système
amorceur destiné à rendre la composition durcissable à la chaleur ou par rayonnement.
Dispersion polymère aqueuse selon l'une quelconque des revendications 1 à 4,
dans laquelle les particules polymères de la dispersion présentent une température
minimale de formation de films inférieure à 60°C.
Peinture comprenant une composition selon l'une quelconque des revendications
1 à 4.