Note: Descriptions are shown in the official language in which they were submitted.
A 02825450 2013-07-23
Impact-modified reaction resin
Field of the invention
The present invention comprises a novel formulation for
marking or coating floor surfaces or trafficways, for
example roads, which when compared with the prior art
have improved mechanical properties and improved heat
resistance during curing. The invention also relates to
improved reactive resins for other applications than
roadmarkings. The present invention in particular
relates to reactive resins which comprise core-shell
particles.
Modern trafficway markings are subject to a large
number of requirements. Firstly, these systems are
expected to be easy to apply on the road surface and at
the same time to provide long shelf life, and also to
provide a marking with long lifetime. Other important
factors are capability for rapid operations and in
particular capability for operations over the widest
possible temperature range. Many reactive roadmarking
and floorcoating systems of the prior art cure in an
excessively uncontrolled manner at temperatures above
40 C. Results can be blistering, tacky surfaces, and
regions where curing is incomplete. This leads in turn
to reduced adhesion values and shortened lifetimes. In
contrast, at temperatures below 10 C hardening is very
slow, and newly marked road sections have to be removed
from use for a prolonged period, or an artificial
method has to be used to adjust the temperature of the
markings. Marking operations using systems of the prior
art are often completely impossible at temperatures
below freezing point.
.......
2
Prior art
For quite some time now, an aim of development work has
been to improve temperature dependency during the
hardening of reactive resins, and also to improve their
mechanical properties. Examples of systems currently
used for trafficway marking materials are solvent-based
paints, aqueous paints, thermoplastic paints, paints
based on reactive resins, and also prefabricated
adhesive tapes. A disadvantage of the latter is that
they are complicated to produce and to apply. There are
also restrictions on the freedom available in respect
of the design of the marking for desirable long life,
e.g. use of glass beads.
Thermoplastic coatings which are applied in the molten
state to the trafficway surface can per se also be
optimized for high hardening rate. Their use has the
great disadvantage of an additional step in that the
product first has to be melted, for example at 20000,
before it can be applied. Firstly, this is potentially
dangerous because of the high temperature, and secondly
thermoplastic systems per se have relatively high
susceptibility to abrasion, and relatively low thermal
stability. Thermoplastic systems often have markedly
shorter life than systems which are based by way of
example on reactive resins and which react with
crosslinking.
Reactive-resin systems of the prior art are typically
flexibilized by adding, to the monomer-polymer mixture,
(meth)acrylic comonomers or plasticizers which lower
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the glass transition temperature of the hardened
composition, an example being n-butyl acrylate,
2-ethylhexyl acrylate, or other long-chain or branched
monomers that can be cured by a free-radical route,
where the homopolymer of these has a glass transition
temperature below 000. However, these monomers generate
another known problem, since when monomers of this type
are added for flexibilization the typically incomplete
hardening of these in the application increases VOC
content and long-term odor problems due to slow
evaporation of the monomers, and also slows hardening.
Object
It is an object of the present invention to provide a
novel reactive resin which, irrespective of the
application, has a longer lifetime when compared with
the prior art.
In particular, an object of the present invention is to
provide a novel reactive resin, by way of example for
formulations for the marking of trafficway surfaces,
which has improved mechanical properties, in particular
with regard to the combination of hardness and
flexibility, in comparison with the prior art. The
improvements to be made in mechanical properties in
particular relate to reduction of crack propagation, to
flexibilization, to greater mechanical strength, and to
improved capability to withstand point load.
Another object of the present invention is to provide a
novel formulation for the marking of trafficway
surfaces which, in comparison with the prior art, has
longer lifetime.
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The formulation for the marking of trafficway surfaces
is moreover intended to be capable of application
without blistering irrespective of the ambient
temperature in the range from 5 C to 50 C.
A particular object consists in providing a reactive
resin which, in comparison with the prior art, can give
trafficway markings with longer life, with good
substrate adhesion, with good retroreflective
properties, with good day- and night-visibility, with
high, stable whiteness, and with good grip capability,
even when the trafficway is wet.
Other objects not explicitly mentioned are apparent
from the entire context of the description, claims, and
examples below.
Achievement of object
The objects are achieved via a novel reactive resin
which comprises at least one crosslinking agent,
monomers, polymers, and at least one impact modifier.
It is preferable that the objects are achieved via a
novel reactive resin which comprises at least one
crosslinking agent, monomers, polymers, and at least
one core-shell polymer.
In particular, the objects are achieved via a novel
reactive resin which has at least the following
ingredients:
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from 0.5% by weight to 30% by weight of
crosslinking agent, preferably dimethacrylates,
from 20% by weight to 85% by weight of
monomers, preferably (meth)acrylates and/or
components copolymerizable with (meth)acrylates,
from 0% by weight to 20% by weight of urethane
(meth)acrylates,
from 3% by weight to 40% by weight of
prepolymers, preferably poly(meth)acrylates,
from 0% by weight to 5% by weight of
accelerator, preferably amines,
from 1% by weight to 25% by weight of core-
shell polymer, preferably comprising
poly(meth)acrylates, and
optionally other auxiliaries.
The other auxiliaries can by way of example involve
stabilizers, inhibitors, chain-transfer agents, or
waxes.
The expression poly(meth)acrylates comprises not only
polymethacrylates but also polyacrylates, and also
copolymers and mixtures of the two. The expression
(meth)acrylates correspondingly comprises
methacrylates, acrylates, and mixtures of the two.
The present invention also comprises sprayable and
other cold plastics comprising the reactive resin of
the invention. These cold plastics have the following
components:
from 5 to 60% by weight of the reactive resin
described above,
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from 1 to 5% by weight of a mixture comprising
one or more initiators, preferably peroxides,
from 7 to 15% by weight of an inorganic
pigment, preferably titanium dioxide, and
from 50 to 60% by weight of mineral fillers.
In the use for the marking of trafficway surfaces, the
components of the cold plastic are mixed before or
during application on the trafficway surface. In the
case of other uses, the use determines whether the
components are appropriately mixed shortly before or
during the casting process, coating process, or
charging process.
It is preferable that the peroxide involves dilauroyl
peroxide and/or dibenzoyl peroxide. It is preferable
that the amine involves a tertiary, aromatically
substituted amine.
In an alternative embodiment, the peroxide is a
constituent of the reactive resin, and the accelerator
is not a constituent of the reactive resin, but instead
is a separate component of the cold plastic.
The dispersion of the core-shell particles in the
monomer-polymer mixture of the reactive resin has to be
good in order to avoid causing any haze or clumping.
This can easily be ensured through appropriate stirring
or by means of any other known dispersion technique.
Surprisingly, the addition of core-shell particles, in
particular known as impact modifiers for by way of
example PMMA molding compositions or PVC achieved a
....
7
decisive improvement in significant properties of
reactive acrylic resins.
Mention should especially be made here of high
flexibility of structures which are nevertheless hard,
and also of improved resistance to temperature change
during the curing process, with avoidance of
blistering. The content of the core-shell particles
introduced into the reactive resins is from 1 to 25% by
weight, preferably from 1 to 15% by weight,
particularly preferably from 2 to 12% by weight.
Said properties lead to greater mechanical strength and
moreover to reduced crack propagation and to greater
capability to withstand point load.
Overall, the reactive resins of the invention, the cold
plastics produced therefrom, and the trafficway
markings produced by way of example in turn therefrom,
have a longer lifetime than systems of the prior art.
They also exhibit improved adhesion through avoidance
of breakaway from the substrate, since the material is
capable of compensating, or bridging, any shrinkage
stresses that may arise. Other properties that can be
observed, in comparison with the prior art, are
improved adhesion to the substrate, and also markedly
improved shrinkage behavior.
Surprisingly, it has been found that said properties
are obtained irrespective of temperature in the
temperature range relevant to the application of from
-30 C to 70 C, preferably from -10 C to 50 C.
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Surprisingly, it has also been found that the
mechanical properties of the trafficway marking of the
invention are independent of the application thickness
in a typical range from 200 pm to 7000 pm. The
application thickness of the sprayable or other cold
plastic of the invention is preferably from 400 pm to
1000 pm, and particularly preferably from 600 gm to
800 pm. Thinner and thicker layers are of course
possible in appropriate applications.
Surprisingly, it has also been found that a trafficway
marking obtainable through application of a cold
plastic of the invention, comprising a reactive resin
of the invention that comprises core-shell particles
can be formulated in such a way that it hardens rapidly
and after as little as 10 min, or if formulated
appropriately after as little as 5 min, has sufficient
strength, substrate adhesion, dimensional stability,
and abrasion resistance to permit passage of traffic
thereover to resume. The result of this in an
application in the road traffic sector is that when the
system of the invention is used it is no longer
necessary that the trafficway section requiring marking
is subjected to complicated and lengthy removal from
use.
The expression capability to withstand wheeled traffic
and the expression capability to permit resumption of
passage of traffic, used synonymously, mean that the
trafficway marking can be subjected to load, for
example can support vehicular traffic. The period
required to achieve capability to withstand wheeled
traffic is the period from the application of the
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trafficway marking to the juncture at which it is no
longer possible to discern any alterations in the form
of abrasion, of adhesion loss in respect of the
trafficway surface or in respect of the embedded glass
beads, or of any deformation of the marking.
Dimensional stability and stability of adhesion are
measured in accordance with DIN EN 1542 99 in
conjunction with DAfStb-RiLi 01.
The impact modifier
The person skilled in the art is aware of a large
number of impact modifiers, e.g. elastomer particles.
These are especially used in plastics which are
intrinsically brittle, for example PVC or PMMA, in
order to increase impact resistance. It is preferable
that the impact modifiers involve core-shell particles.
The core-shell particles
The core-shell particles, also termed impact modifiers,
can be added in various embodiments, which lead to the
same reactive resin of the invention.
In a first embodiment, the core-shell particles are
added directly. This embodiment has the advantage that
when the polymer that also has to be added is selected
there is greater freedom in relation to the form in
which it is added, an example being the form of a fine-
grain or suspension polymer.
The pure core-shell particles can be used directly in
the form of coagulate, in the form of spray product, or
in the form of freeze-dried product, or in the form of
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pelletized material obtained through extrusion of an
emulsion polymer (extrusion with pressurized removal of
material), as described in DE19927769 and in the
publications cited therein.
5
The core of the core-shell particle mostly involves an
engineering thermoplastic or elastomer that can be
obtained through grafting or emulsion polymerization
with use of a seed latex, or through sequential
10 emulsion polymerization. Materials generally used as
core material are amorphous copolymers with glass
transition temperature below 0 C, for example acrylate
rubbers, ASA rubbers, diene rubbers, organosiloxane
rubbers, EPDM rubbers, SBS rubbers, SEBS rubbers, ABS
rubbers, and MBS rubbers, or else ethylene-based cores,
examples being EnBA copolymers and EMA copolymers. The
cores can optionally have been functionalized with
reactive groups, e.g. epoxy groups or anhydride groups.
These and other materials used for impact modification
are described by way of example in DE 10 2005 034 999
and in the publications cited therein.
In other embodiments, the core-shell particles are
added in the form of an impact-modified molding
composition which comprises core-shell particles and at
least a portion of the polymer. This embodiment has the
advantage that dispersion of the core-shell particle in
the reactive resin can be carried out more rapidly and
more simply. Suspension polymers of this type
comprising core-shell particles are marketed by way of
example as zk50 by Evonik Rohm GmbH. Other embodiments
would be masterbatches comprising core-shell particles
and comprising other polymers. This type of masterbatch
can by way of example be obtained through extrusion.
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Another possibility would be to use a specific reactive
resin masterbatch.
Impact modifiers, e.g. for polymethacrylate plastics,
are well known. Impact modifiers used in the invention
are in particular polymer particles which can have a
two- or three-layer core-shell structure, and which are
obtained by emulsion polymerization. Impact modifiers
of this type are described by way of example in EP-A 0
113 924, EP-A 0 522 351, EP-A 0 465 049, and EP-A 0 683
028. For the purposes of this invention, suitable
particle sizes of said emulsion polymers are preferably
in the range from 25 nm to 1000 nm, preferably from
50 nm to 700 nm, and particularly preferably from 80 nm
to 500 nm.
The structure of the core-shell particles here can have
two, three, or more shells. It is preferable that the
core-shell particles comprise at least one hard phase
and at least one tough phase. The hard phase here
features a high glass transition temperature of at
least 70 C. At the same time, the glass transition
temperature Tg of the tough phase is below -10 C. In
the case of a two-shell core-shell particle, both the
hard phase and the tough phase can form the core. The
core is generally formed by the tough phase.
A three-layer or three-phase structure with a core and
with two shells can take the following form. It is
preferable that the core and the outermost shell are
hard phases, while the middle shell is a tough phase.
The outermost hard phase improves compatibility and
provides good coupling to a matrix. The structure of
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this type of core-shell particle can by way of example
take the following form:
The hard core can by way of example consist essentially
of methyl methacrylate, of small proportions of
comonomers, such as ethyl acrylate, and of a proportion
of crosslinking agent, e.g. allyl methacrylate. The
middle, soft shell (tough phase) can by way of example
be composed of butyl acrylate and optionally styrene,
while the outermost, hard shell in essence mostly
corresponds to the matrix polymer. However, it is also
possible to conceive of other embodiments, such as
soft-hard-soft, soft-hard-hard, or hard-soft-soft. The
composition of the outermost shell is preferably
adapted to be appropriate to the ambient matrix, and at
least one of the two inner shells should involve a
tough phase, in order to improve impact resistance.
It is preferable that the core and/or at least one
shell of the core-shell particle has/have been
crosslinked. This crosslinking stabilizes the particle
and improves impact-resistance properties to a marked
extent.
The embodiment of a two-phase, impact-modified polymer
can by way of example use a system known in principle
from EP 0 528 196 Al:
a) from 10 to 95% by weight of a coherent hard phase
composed of from 80 to 100% by weight of methyl
methacrylate and from 0 to 20% by weight of one or more
other ethylenically unsaturated monomers capable of
free-radical polymerization, and
b) dispersed within the hard phase, from 5 to 90% by
weight of a tough phase composed of from 50 to 99.5% by
weight of a C1-C10-alkyl acrylate, of from 0.5 to 5% by
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weight of a crosslinking monomer having two or more
ethylenically unsaturated moieties capable of free-
radical polymerization, and optionally of other
ethylenically unsaturated monomers capable of free-
radical polymerization, where at least 15% by weight of
the hard phase a) has covalent linkage to the tough
phase b).
A two-phase impact modifier can be produced by two-
stage emulsion polymerization in water, as described by
way of example in DE 38 42 796. The first stage by way
of example produces the tough phase, which is composed
of at least 50% by weight, preferably of more than 80%
by weight, of lower alkyl acrylates, giving a glass
transition temperature Tg below -10 C for this phase.
Crosslinking monomers used comprise (meth)acrylates of
diols, for example ethylene glycol dimethacrylate or
1,4-butanediol dimethacrylate, aromatic compounds
having two vinyl or allyl groups, for example
divinylbenzene, or other crosslinking agents having two
ethylenically unsaturated moieties capable of free-
radical polymerization, e.g. allyl methacrylate, as
graft-linking agent. Examples that may be mentioned of
crosslinking agents having three or more unsaturated
groups capable of free-radical polymerization, for
example allyl groups or (meth)acrylic groups, are
triallyl cyanurate, trimethylolpropane triacrylate, and
trimethylolpropane trimethacrylate, and also
pentaerythritol tetraacrylate, and pentaerythritol
tetramethacrylate. Other examples here are given in US
4,513,118.
The ethylenically unsaturated monomers mentioned,
capable of free-radical polymerization, can by way of
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example be acrylic or methacrylic acid, or else alkyl
esters thereof having from 1 to 20 carbon atoms, where
the alkyl moiety can be linear, branched, or cyclic. It
is also possible to use other aliphatic comonomers
capable of free-radical polymerization that are
copolymerizable with the alkyl acrylates. However,
significant proportions of aromatic comonomers, such as
styrene, alpha-methylstyrene or vinyltoluene, should be
avoided since they can lead to undesired properties of
the final product - especially on exposure to weather.
The alternative addition form of an impact-modified
molding composition, preferably of an impact-modified
polyester molding composition or of an impact-modified
PMMA molding composition, particularly preferably of a
PMMA molding composition, is composed of from 1 to 80%
by weight, preferably from 20 to 70% by weight, of a
matrix polymer, preferably of a poly(meth)acrylate, and
of from 99 to 20% by weight, preferably from 80 to 30%
by weight, of core-shell particles, as described above.
Said impact-modified molding compositions can be mixed
in the melt in an extruder, as described in DE19927769,
by adding the core-shell particles, used in coagulated
or spray-dried form or in the form of dispersion in
water, and optionally the matrix polymer, to give
impact-modified molding compositions. A possibility
here is that during the coagulation of a dispersion
that is used, water used is removed from the extruder
and a dry melt is thus obtained. The material
discharged is generally then chopped to give pellets.
These can be subjected to further milling if necessary.
The matrix polymer can by way of example be composed of
from 60 to 100% by weight of methyl methacrylate units
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polymerized by a free-radical route and optionally from
0 to 40% by weight of other comonomers capable of free-
radical polymerization, e.g. Ci-C4-alkyl
(meth)acrylates, in particular methyl, ethyl, propyl,
5 or butyl (meth)acrylate. It is preferable that the
weight-average molar mass M, of the matrix is in the
range from 2000 g/mol to 200 000 g/mol, with preference
from 25 000 g/mol to 150 000 g/mol, with particular
preference from 50 000 g/mol to 150 000 g/mol (Mw being
10 determined by means of gel permeation chromatography
with reference to polymethyl methacrylate as standard).
Components of cold plastic or reactive resin
15 The sprayable or other cold plastic can also comprise
other auxiliaries, such as wetting agents and/or
dispersing agents, an (antislip) filler providing grip,
and antisettling agents. It is also possible that the
glass beads that are added in order to improve
reflectance are already present in this component of
the cold plastic.
Another possible alternative is that these are a
constituent of the second component, and it is
preferable, if the mechanism of application of the
trafficway marking is appropriate, that the glass beads
are applied in the form of third component. In this
procedure, for example used with modern marking
vehicles using a second nozzle, the beads are applied
by spraying onto the first two components directly
after these have been applied. An advantage of this
procedure is that the portion of the glass beads wetted
by the constituents of the other two components is only
the portion embedded into the marking matrix, and ideal
reflective properties are obtained. However, a very
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important consideration when this technology is used is
particularly good embedment of the glass beads and
correspondingly good adhesion of the marking matrix, or
of the trafficway marking formulation, on the surface
of the glass beads. Surprisingly, it has been found
that the reactive resin of the invention, or the
sprayable cold plastic of the invention, comprising
said reactive resin, complies with these required
properties at least at the level of the prior art.
Detailed regulation of the properties required from a
roadmarking is provided by DIN EN 1436.
In order to achieve a further improvement in the
required properties, the glass beads can be applied
together with adhesion promoters or can be pretreated
therewith. The retroreflective properties and the day-
and night-visibility of the cold plastic of the
invention are thus at least comparable with the prior
art. The same applies to lifetime, in particular of the
embedment of the glass beads.
The second component of the sprayable or other cold
plastic comprises the initiator. Polymerization
initiators used are in particular peroxides or azo
compounds. It can sometimes be advantageous to use a
mixture of various initiators. It is preferable to use
halogen-free peroxides, such as dilauroyl peroxide,
dibenzoyl peroxide, tert-butyl peroctanoate, di(tert-
butyl) peroxide (DTBP), di(tert-amyl) peroxide (DTAP),
tert-butyl 2-ethylhexylperoxycarbonate (TBPEHC), and
other peroxides that decompose at high temperature, as
free-radical initiator. For reactive resins for use by
way of example for trafficway markings particular
preference is given to dilauroyl peroxide or dibenzoyl
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peroxide. The general rule is that there is a diluent,
for example a phthalate such as dibutyl phthalate, an
oil, or another plasticizer admixed with the peroxide
in the second component. The cold plastic of the
invention, in the form of entirety of the first and of
the second, and also optionally of the third, component
comprises from 0.1% by weight to 7% by weight,
preferably from 0.5% by weight to 6% by weight, and
very particularly preferably from 1% by weight to 5% by
weight, of the initiator or of the mixture of the
initiator and of the diluent.
The preferred embodiment of a redox initiator system
for reactive resins is peroxides combined with
accelerators, in particular amines. Examples that may
be mentioned of said amines are tertiary aromatically
substituted amines, e.g. in particular N,N-dimethyl-p-
toluidine, N,N-bis(2-hydroxyethyl)-p-toluidine and N,N-
bis(2-hydroxypropy1)-p-toluidine. The reactive resin of
the invention can comprise up to 5% by weight, and very
particularly preferably up to 3% by weight, of an
accelerator.
In an alternative embodiment of an alternative 2C or 3C
system, the accelerator is present in the second
component, for example in a diluent, and the initiator,
for example the peroxide, is a constituent of the
reactive resin of the invention. The optional third
component in turn involves the glass beads and any
adhesion promoters required.
The crosslinking agents are a constituent of decisive
importance in the reactive resin of the invention. In
particular polyfunctional methacrylates, such as ally'
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(meth)acrylate. Particular preference is given to di-
or tri(meth)acrylates, for example 1,4-butanediol
di(meth)acrylate, poly(urethane)
(meth)acrylates,
tetraethylene glycol di(meth)acrylate, triethylene
glycol di(meth)acrylate, or trimethylolpropane
tri(meth)acrylate. The proportion of crosslinking agent
is markedly higher than in the prior art, and is from
13% by weight to 35% by weight, preferably from at
least 20% by weight to at most 30% by weight.
Surprisingly, it has been found that this relatively
high proportion of crosslinking agent provides not only
a high degree of initial curing but also, in
combination with the other components, provides rapid
capability of the trafficway marking, comprising the
resin of the invention, to withstand wheeled traffic.
For the purposes of this invention, the urethane
(meth)acrylates optionally present are compounds which
have (meth)acrylate functionalities linked to one
another by way of urethane groups. They are obtainable
through the reaction of hydroxyalkyl (meth)acrylates
with polyisocyanates and polyoxyalkylenes which have at
least two hydroxy functionalities. Instead of
hydroxyalkyl (meth)acrylates it is also possible to use
esters of (meth)acrylic acid with oxiranes, such as
ethylene oxide or propylene oxide, or with
corresponding oligo- or polyoxiranes. An overview by
way of example of urethane (meth)acrylates having a
functionality greater than two is found in DE 199 02
685. A commercially available example produced from
polyols, isocyanates, and hydroxy-
functional
(meth)acrylates is EBECRYL 210-5129 from UCB Chemicals.
Urethane (meth)acrylates increase flexibility, ultimate
tensile strength, and tensile strain at break in a
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reactive resin without any major temperature
dependency. This has surprisingly been found to have
two types of effect on the trafficway marking: The
resistance of the marking to temperature changes
increases and, particularly surprisingly, it is
possible to achieve compensation for the disadvantages
of a relatively high degree of crosslinking resulting
from the relatively high content of crosslinking agent
in relation to embrittlement and adhesion to the
trafficway surface, or even to make improvements in
comparison with cold plastics of the prior art. For
this, the concentration of the urethane (meth)acrylates
in the reactive resin has to be relatively high for
trafficway markings. The reactive resin of the
invention comprises from 5% by weight to 30% by weight,
preferably from 10% by weight to 20% by weight, of the
urethane (meth)acrvlates described.
The monomers present in the reactive resin involve
compounds selected from the group of the
(meth)acrylates, such as alkyl (meth)acrylates of
straight-chain, branched, or cycloaliphatic alcohols
having from 1 to 40 carbon atoms, for example methyl
(meth)acrylate, ethyl (meth)acrylate, n-butyl
(meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl
(meth)acrylate, lauryl (meth)acrylate; aryl
(meth)acrylates, for example benzyl (meth)acrylate;
mono(meth)acrylates of ethers, of polyethylene glycols,
or of polypropylene glycols, or mixtures thereof having
from 5 to 80 carbon atoms, examples being tetrahydro-
furfuryl (meth)acrylate,
methoxy(m)ethoxyethyl
(meth)acrylate, benzyloxymethyl
(meth)acrylate,
1-ethoxybutyl (meth)acrylate, 1-
ethoxyethyl
(meth)acrylate, ethoxymethyl
(meth)acrylate,
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poly(ethylene glycol) methyl ether (meth)acrylate, and
poly(propylene glycol) methyl ether (meth)acrylate.
Other suitable constituents of monomer mixtures are
5 additional monomers having a further functional group,
for example a,-unsaturated mono- or dicarboxylic
acids, e.g. acrylic acid, methacrylic acid, or itaconic
acid; esters of acrylic acid or methacrylic acid with
dihydric alcohols, for example
hydroxyethyl
10 (meth)acrylate or hydroxypropyl (meth)acrylate;
acrylamide or methacrylamide; or dimethylaminoethyl
(meth)acrylate. Other suitable constituents of monomer
mixtures are by way of example glycidyl (meth)acrylate
and silyl-functional (meth)acrylates.
15 The monomer mixtures can also comprise, alongside the
(meth)acrylates described above, other unsaturated
monomers which are copolymerizable with the
abovementioned (meth)acrylates and by means of free-
radical polymerization. Among these are inter alia
20 1-alkenes or styrenes.
The detailed selection of the proportion and
composition of the poly(meth)acrylate will
advantageously depend on the desired technical
function.
The monomer content of the reactive resin here is from
20% by weight to 85% by weight, preferably from 30% by
weight to 40% by weight.
Systems known as MO-PO systems comprise not only the
monomers listed but also polymers, preferably
polyesters or poly(meth)acrylates, and for the purposes
of this patent the term prepolymer is used for these in
order that they are more clearly distinguishable. These
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21
polymers are used to improve polymerization properties,
mechanical properties, adhesion to the substrate, and
also the optical requirements placed upon the resins.
The prepolymer content of the reactive resin here is
from 10% by weight to 30% by weight, preferably from
15% by weight to 25% by weight. The polyesters, and
also the poly(meth)acrylates, can have additional
functional groups to promote adhesion or for
copolymerization in the crosslinking reaction, for
example taking the form of double bonds. However, it is
preferable with a view to better colorfastness of the
trafficway marking that the prepolymers have no double
bonds.
Said poly(meth)acrylates are generally composed of the
monomers already listed in relation to the monomers in
the resin system. They can be obtained by solution
polymerization, emulsion polymerization, suspension
polymerization, bulk polymerization, or precipitation
polymerization, and are added in the form of pure
substance to the system.
Said polyesters are obtained in bulk via
polycondensation or ring-opening polymerization, and
are composed of the units known for these applications.
Chain-transfer agents, plasticizers, paraffins,
stabilizers, inhibitors, waxes, and/or oils can also be
used as auxiliaries and additives.
The paraffins are added in order to prevent inhibition
of the polymerization by the oxygen in air. To this
end, it is possible to use a plurality of paraffins
with different melting points, in different
concentrations.
A 02825450 20
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Chain-transfer agents that can be used are any of the
compounds known from free-radical polymerization. It is
preferable to use mercaptans, such as N-dodecyl
mercaptan.
Plasticizers used are preferably esters, polyols, oils,
or low-molecular-weight polyethers, or phthalates.
Dyes, glass beads, fine and coarse fillers, wetting
agents, dispersing agents, and flow control agents, UV
stabilizers, antifoams, and rheology additives can also
be added to the formulations for trafficway markings.
Preferred auxiliaries and additives added for the field
of application of the formulations as trafficway
marking or surface marking are dyes. Particular
preference is given to white, red, blue, green and
yellow inorganic pigments, and white pigments such as
titanium dioxide are particularly preferred.
Glass beads are preferably used as reflectors in
formulations for trafficway markings and surface
markings. The commercially available glass beads used
have diameters of from 10 pm to 2000 pm, preferably
from 50 pm to 800 pm. The glass beads can be provided
with a coupling agent in order to facilitate operations
and improve adhesion. The glass beads can preferably be
silanized.
One or more mineral fillers having fine particles and
fillers having coarse particles can moreover be added
to the formulation. These materials also serve to
reduce slip, and are therefore in particular used to
improve grip, and for additional coloring of the
trafficway marking. Fillers used having fine particles
are selected from the group of the calcium carbonates,
CAM254502013N23
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barium sulfates, powdered and other quartzes,
precipitated and fumed silicas, pigments, and
cristobalites, and also corundum. Fillers used having
coarse particles are quartzes,
cristobalites,
corundums, and aluminum silicates.
It is also possible to use conventional UV stabilizers.
It is preferable that the UV stabilizers are selected
from the group of the benzophenone derivatives,
benzotriazole derivatives, thioxanthonate derivatives,
piperidinolcarboxylic ester derivatives, or cinnamic
ester derivatives.
From the group of the stabilizers and inhibitors, it is
preferable to use substituted phenols, hydroquinone
derivatives, phosphines, and phosphites.
The following components can optionally also be present
in formulations for trafficway marking:
wetting agents, dispersing agents, and flow-control
agents are preferably selected from the group of the
alcohols, hydrocarbons, glycol derivatives, polyethers,
polysiloxanes, polycarboxylic acids, saturated and
unsaturated polycarboxylic aminoamides, and derivatives
of glycolic esters, of acetic esters, and of
polysiloxanes.
Preferred rheology additives used are polyhydroxy-
carboxamides, urea derivatives, salts of unsaturated
carboxylic esters, alkylammonium salts of acidic
phosphoric acid derivatives, ketoximes, amine salts of
p-toluenesulfonic acid, amine salts of sulfonic acid
derivatives, and also aqueous or organic solutions or
mixtures of the compounds. Rheology additives based on
fumed or precipitated, optionally also silanized,
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silicas with BET surface area of from 10 to 700 nm2/g
have been found to be particularly suitable.
Antifoams are preferably selected from the group of the
alcohols, hydrocarbons, paraffin-based mineral oils,
glycol derivatives, and derivatives of glycolic esters,
of acetic esters, and of polysiloxanes.
These elements of freedom of formulation show that the
reactive resin of the invention and the sprayable or
other cold plastic of the invention, comprising the
reactive resin, is precisely equivalent to any
established sprayable or other cold plastic of the
prior art in its capability for formulation and for use
of additives. Abrasion resistance, lifetime, whiteness,
pigmentation, and grip capability are thus at least as
good as in systems of the prior art. Surprisingly,
however, it has been found that lifetime and adhesion,
based on the particular mechanical properties
explained, and on the additional adhesion-promoting
properties of the urethane (meth)acrylates, are
actually better than described in the prior art.
The shelf life of the reactive resin is also at least
comparable with the prior art.
The system can also be optimized in relation to the
substrate to be coated, by means of selection of
suitable monomers, prepolymers, and/or adhesion
promoters. The systems of the invention can accordingly
be variably optimized for the marking of asphalt
surfaces, concrete surfaces, or natural stone surfaces.
Use of the reactive resins or sprayable or other cold
plastics
A 02825450 20
The systems of the invention are also versatile in
relation to application technology. The reactive resins
or cold plastics of the invention can by way of example
be applied either by spraying, by pouring, or else by
5 extrusion, or manually by means of a trowel, a roller,
or a doctor system.
The individual components of the cold plastic, for
example the reactive resin of the invention, can be
10 mixed before, after, or during further operations, e.g.
application on a trafficway surface. An established
method is incorporation by mixing before further
operations, but a factor requiring attention here is
that only a limited amount of open time, e.g. 2 or
15 40 min, remains for the application process once mixing
to incorporate the hardener component has been carried
out.
Mixing during operations can be carried out by way of
example in modern marking machines which have a mixing
20 chamber preceding the application nozzle.
Mixing to incorporate the hardener after the
application process can be achieved by way of example
through a subsequent application, using two or more
nozzles, or through application of glass beads coated
25 with hardener. As an alternative, a primer comprising
the hardener component can be sprayed in advance before
the sprayable or other cold plastic is applied.
It is preferable that the reactive resins of the
invention and the cold plastics produced therefrom are
used for the production of trafficway markings with
long lifetime.
, 02825450 2C
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In particular, the reactive resins and cold plastics
are used in a process in which glass beads are added
before, during, or directly after the application of
the cold plastic on a trafficway surface.
As an alternative, the reactive resins and/or cold
plastics of the invention can also be used in other
technical fields. Examples of these are floorcoverings,
preferably for industrial applications, production of
cast parts, sealing of bridges or joints thereof, in
particular in the form of vapor-barrier membrane,
bridge coating generally, vapor-barrier membrane on
roofs, production of sheets, e.g. for subsequent use as
worktop, drainage-system resin, crack-filling, for
example in buildings, and use in the orthopedic sector.
The examples given below are provided for further
illustration of the present invention, but do not
restrict the invention to the features disclosed
therein.
Examples
The production of the test specimens and the
measurement of tensile strength, of modulus of
elasticity, of tensile strain at yield, of yield
stress, and of tensile strain at break were carried out
as in ISO 527.
The core-shell-shell particles used are composed of 23%
by weight of core, 47% by weight of shell 1, and 30% by
weight of shell 2.
The core here has the following constitution:
A 02825450 2013
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95.5% by weight of methyl methacrylate, 4% by
weight of ethyl acrylate, 0.5% by weight of allyl
methacrylate.
Shell 1 has the following constitution:
81% by weight of n-butyl acrylate, 17.5% by weight
of styrene, 1.5% by weight of ally' methacrylate.
Shell 2 has the following constitution:
96.5% by weight of methyl methacrylate, 4% by
weight of ethyl acrylate, 0.5% by weight of n-dodecyl
mercaptan.
Example 1:
0.05 part of topano1-0, 15 parts of Degacryl M339
(Evonik Rohm GmbH), 10 parts of core-shell-shell
particles, and 0.5 part of paraffin were intimately
mixed with 63 parts of methyl methacrylate and 5 parts
of triethylene glycol dimethacrylate and heated, with
vigorous stirring, to 63 C until all of the polymer
constituents had been dissolved or dispersed. For
curing, 1 part of benzoyl peroxide (50% by weight
formulation in dioctyl phthalate) and 1.9 parts of N,N-
diisopropoxytoluidine were added and incorporated by
stirring for 1 minute at room temperature (21 C). For
hardening, the composition was poured onto a metal
sheet, and test specimens were produced in accordance
with DIN 50125.
Pot life: 11 min; curing time: 22 min; flow time
(8 mm): 74 sec.
Example 2:
0.05 part of topano1-0, 13 parts of Degacryl M339, 9
parts of core-shell-shell particles, and 0.5 part of
paraffin were intimately mixed with 63 parts of methyl
methacrylate and 5 parts of butyl diglycol
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dimethacrylate and heated, with vigorous stirring, to
63 C until all of the polymer constituents had been
dissolved or dispersed. For curing, 1 part of benzoyl
peroxide (50% by weight formulation in dioctyl
phthalate) and 2 parts of N,N-diisopropoxytoluidine
were added and incorporated by stirring for 1 minute at
room temperature (21 C)
For hardening, the composition was poured onto a metal
sheet, and test specimens were produced in accordance
with DIN 50125.
Pot life: 14 min; curing time: 30 min; flow time
(4 mm): 244 sec.
Example 3:
0.05 part of topano1-0, 25 parts of Degalan LP 66/02,
and 0.5 part of paraffin were intimately mixed with 63
parts of methyl methacrylate and 5 parts of triethylene
glycol dimethacrylate and heated, with vigorous
stirring, to 63 C until all of the polymer constituents
had been dissolved. For curing, 1 part of benzoyl
peroxide (50% by weight formulation in dioctyl
phthalate) and 1.9 parts of N,N-diisopropoxytoluidine
were added and incorporated by stirring for 1 minute at
room temperature (21 C). For hardening, the composition
was poured onto a metal sheet, and test specimens were
produced in accordance with DIN 50125.
Pot life: 13 min; curing time: 29 min; flow time
(4 mm): 78 sec.
Example 4:
0.05 part of topano1-0, 22 parts of Degalan LP 64/12
and 0.5 part of paraffin were intimately mixed with 63
parts of methyl methacrylate and 5 parts of butyl
diglycol dimethacrylate and heated, with vigorous
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stirring, to 63 C until all of the polymer constituents
had been dissolved or dispersed. For curing, 1 part of
benzoyl peroxide (50% by weight formulation in dioctyl
phthalate) and 2 parts of N,N-diisopropoxytoluidine
were added and incorporated by stirring for 1 minute at
room temperature (21 C)
For hardening, the composition was poured onto a metal
sheet, and test specimens were produced in accordance
with DIN 50125.
Pot life: 16 min; curing time: 33 min; flow time
(4 mm): 64 sec.
Table 1 with measurement results:
Measurement Example 1 Example 2 Example 3 Example 4
Tensile 43.7 MPa 50.6 MPa 41.8 MPa 52.7 MPa
strength
Modulus of 2181 MPa 2488 MPa 2731 MPa 2630 MPa
elasticity
Tensile strain 3.6% 3.9% 0% 0%
at yield
Yield stress 43.8 MPa 50.8 MPa 0 MPa 0 MPa
Tensile strain 5.1% 6.7% 1.8% 3.1%
at break
Example 5:
0.05 part of topano1-0, 15 parts of zk50, and 0.5 part
of paraffin were intimately mixed with 75 parts of
methyl methacrylate and 5 parts of butyl diglycol
dimethacrylate and heated, with vigorous stirring, to
63 C until all of the polymer constituents had been
dissolved or dispersed. For curing, 1 part of benzoyl
peroxide (50% by weight formulation in dioctyl
phthalate) and 2 parts of N,N-diisopropoxytoluidine
A 02825450 20
were added and incorporated by stirring for 1 minute at
room temperature (21 C)
For hardening, the composition was poured onto a metal
sheet.
5 Pot life: 11 min; curing time: 22 min; flow time
(8 mm): 95 sec.
Example 6:
0.1 part of topano1-0, 8 parts of Degacryl M339, 8
10 parts of core-shell-shell particles, and 1.5 parts of
paraffin were intimately mixed with 162 parts of methyl
methacrylate and 7 parts of butyl diglycol
dimethacrylate and heated, with vigorous stirring, to
63 C until all of the polymer constituents had been
15 dissolved or dispersed. For curing, 1.5 parts of
benzoyl peroxide (50% by weight formulation in dioctyl
phthalate) and 2.5 parts of N,N-diisopropoxytoluidine
were added and incorporated by stirring for 1 minute at
room temperature (21 C). For hardening, the composition
20 was poured onto a metal sheet, and test specimens were
produced in accordance with DIN 50125.
Pot life: 12 min; curing time: 40 min; flow time
(3 mm): 44 sec.
25 Example 7:
0.1 part of topano1-0, 26 parts of Degalan LP 66/02,
and 1.5 parts of paraffin were intimately mixed with
162 parts of methyl methacrylate and 7 parts of butyl
diglycol dimethacrylate and heated, with vigorous
30 stirring, to 63 C until all of the polymer constituents
had been dissolved. For curing, 1.5 parts of benzoyl
peroxide (50% by weight formulation in dioctyl
phthalate) and 2.5 parts of N,N-diisopropoxytoluidine
were added and incorporated by stirring for 1 minute at
....
31
room temperature (21 C). For hardening, the composition
was poured onto a metal sheet, and test specimens were
produced in accordance with DIN 50125.
Pot life: 13 min; curing time: 29 min; flow time
(3 mm): 31 sec.
Measurement Example 6 Example 7
Tensile strength 39.8 MPa 58.5 MPa
Modulus of elasticity 2265 MPa 2471 MPa
Tensile strain at break 3.2% 5.5%
