U.S. patent application number 12/064245 was filed with the patent office on 2008-10-02 for sprayable acoustic compositions.
This patent application is currently assigned to Evonik Roehm GmbH. Invention is credited to Herbert Jung, Gerd Loehden, Florian Matthess, Jan Hendrik Schattka, Rebecca Zmarzly.
Application Number | 20080237529 12/064245 |
Document ID | / |
Family ID | 37309797 |
Filed Date | 2008-10-02 |
United States Patent
Application |
20080237529 |
Kind Code |
A1 |
Schattka; Jan Hendrik ; et
al. |
October 2, 2008 |
Sprayable Acoustic Compositions
Abstract
The invention relates to sprayable acoustic compositions,
production processes and uses.
Inventors: |
Schattka; Jan Hendrik;
(Hanau, DE) ; Loehden; Gerd; (Essen, DE) ;
Jung; Herbert; (Karlstein, DE) ; Matthess;
Florian; (Moembris, DE) ; Zmarzly; Rebecca;
(Ronneburg, DE) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
Evonik Roehm GmbH
Darmstadt
DE
|
Family ID: |
37309797 |
Appl. No.: |
12/064245 |
Filed: |
August 17, 2006 |
PCT Filed: |
August 17, 2006 |
PCT NO: |
PCT/EP2006/065382 |
371 Date: |
February 20, 2008 |
Current U.S.
Class: |
252/62 |
Current CPC
Class: |
C08L 2666/04 20130101;
C08L 2666/04 20130101; C08L 2666/04 20130101; C09D 133/12 20130101;
C08L 33/12 20130101; C09D 133/12 20130101; C08L 33/12 20130101;
C08L 33/00 20130101; C08L 33/00 20130101 |
Class at
Publication: |
252/62 |
International
Class: |
E04B 1/82 20060101
E04B001/82 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 28, 2005 |
DE |
102005052130.4 |
Claims
1-26. (canceled)
27. A plastisol formulation, comprising a) from 1 to 60% by weight
of oligomers whose molar mass is smaller than 20 000 g/mol, and
which contain at least 30% by weight of (meth)acrylates, b) from 0
to 60% by weight of solvents for the oligomers a), c) from 5 to 60%
by weight of pulverulent polymers whose molar mass is greater than
100 000 g/mol, and d) other fillers, auxiliaries and/or additives,
where components a) to c) make up at least 20% of said
formulation.
28. The plastisol formulation according to claim 27, wherein
components a) to c) make up at least 40% by weight of said
formulation.
29. The plastisol formulation according to claim 27, wherein the
oligomers a) contain at least 60% by weight of (meth)acrylates.
30. The plastisol formulation according to claim 27, wherein the
molar mass of each of the oligomers a) is <10 000 g/mol.
31. The plastisol formulation according to claim 27, wherein the
molar mass of each of the oligomers a) is <5000 g/mol.
32. The plastisol formulation according to claim 27, wherein the
oligomer or one of the oligomers contains free hydroxy, carboxy, or
amide groups.
33. The plastisol formulation according to claim 27, wherein a
phthalate, adipate, phosphate or citrate is used as solvent b).
34. The plastisol formulation according to claim 27, wherein a
phthalate is used as solvent b).
35. The plastisol formulation according to claim 27, wherein the
molar mass of the polymers c) is >400 000 g/mol.
36. The plastisol formulation according to claim 27, wherein at
least one of the polymers c) is composed of more than 60% by weight
of (meth)acrylates.
37. The plastisol formulation according to claim 36, wherein each
of the polymers c) is composed of more than 60% by weight of
(meth)acrylates.
38. The plastisol formulation according to claim 27, wherein at
least one of the polymers c) is composed of more than 80% by weight
of (meth)acrylates.
39. The plastisol formulation according to claim 36, wherein at
least one of the polymers c) is composed of more than 60% by weight
of methyl methacrylate.
40. The plastisol formulation according to claim 36, wherein at
least one of the polymers c) is composed of more than 80% by weight
of methyl methacrylate.
41. The plastisol formulation according to claim 27, wherein the
polymers c) take the form of particles whose size is from 200 to
1200 nm.
42. The plastisol formulation according to claim 27, wherein the
particles c) have a structure in which one or more shells is/are
present with, optionally a different monomer constitution around a
core.
43. The plastisol formulation according to claim 27, wherein the
oligomers a) and/or the polymers c) bear one or more functional
groups which can result in post-crosslinking.
44. The plastisol formulation according to claim 43, wherein said
functional groups are hydroxy groups.
45. The plastisol formulation according to claim 43, wherein
post-crosslinking takes place via the addition of a reactive
component.
46. The plastisol formulation according to claim 45, wherein one of
the reactive components is an isocyanate.
47. The plastisol formulation according to claim 27, wherein the
auxiliary, filler or additive d) is a blowing agent.
48. A surface coating comprising the plastisol formulation
according to claim 27.
49. A sheet metal coating comprising the plastisol formulation
according to claim 27.
50. A coating for bodywork parts in automobile construction
comprising the plastisol formulations according to claim 27.
51. A composition for the damping of vibrations in sheet metal
comprising the plastisol formulations according to claim 27.
52. A composition for the filling of cavities comprising the
plastisol formulations according to claim 27.
Description
[0001] The invention relates to sprayable acoustic compositions,
production processes and uses.
[0002] Surfaces set in vibration emit sound. This can be highly
desirable, for example in the case of musical instruments; however,
it can also be regarded as problematic, especially if this sound is
perceived as noise.
[0003] By way of example, sheet metal in the bodywork of
automobiles is excited via the engine, the road surface or stone
impact to produce vibrations which are perceived as rumble in the
interior of the vehicle.
[0004] In order to damp these undesired sheet metal vibrations, the
automobile industry often applies bitumen mats to the sheet metal.
Although this is a successful method of sound-deadening for the
interior, it has at the same time a large number of
disadvantages.
[0005] A stock of the bitumen mats trimmed to size in the correct
shape has to be held for every surface; when a plurality of shapes
of mat have to be provided for various vehicle models this
represents a challenge in terms of logistics and stock
management.
[0006] Manual labour is used to apply the mats by adhesive bonding,
and this is naturally a cause of quality variations.
[0007] Furthermore, there are some toxicological reservations about
bitumen.
[0008] Sprayable or extrudable compositions have been discussed for
some years as replacement for these bitumen mats, and in many
respects are superior to the bitumen mats.
[0009] These compositions applied by robots can be applied even to
complex-shaped or curved sheet metal without difficulty.
[0010] It is very easy to make adjustments for altered requirements
or change of model.
[0011] Automation can achieve a reduction in the amount of manual
labour and an improvement in process quality.
[0012] Compositions of this kind have been previously described and
are to some extent also now used in small quantities in automobile
production. However, materials of this type have not yet achieved a
breakthrough, since all of the systems proposed hitherto have
disadvantages which inhibit their adoption.
[0013] Firstly, materials based on PVC or on chlorinated
thermoplastics have been proposed, for example in the form of
plastisol in EP 0456473 or EP 766714, or in the form of a
composition requiring hot processing in EP 1277823. However,
chlorine-containing plastics are disadvantageous for environmental
reasons, since they can form HCl and highly toxic dioxins on
incineration, and this also has attendant disadvantages especially
during recycling. In the case of the compositions disclosed in EP
1277823, another disadvantage is the need for hot processing.
[0014] Aqueous dispersions have moreover been described, which on
drying give a film having the desired damping property; materials
of this type are described by way of example in the publications EP
1457530 and EP 1520865. Specifically in the case of relatively
thick layers such as those needed for good damping action, however,
these materials require long drying times in order to remove the
water from the sprayed-on layer. Associated with this there is the
risk of undesired formation of bubbles, especially if the drying
procedure is accelerated.
[0015] Compositions based on epoxy resins have likewise been widely
proposed; examples are provided by the publications EP 0407157, EP
1023413 and EP 1500690. However, there are some reservations about
the constituents of these resins, and they are often allergenic or
even mutagenic and carcinogenic. Since these coatings are often
very hard and brittle they are mostly unsuitable for external use.
Repair in the event of damage is also very difficult with this
material.
[0016] Finally, plasticizers have also been described with binders
based on (meth)acrylate, for example in EP 0702708 or in EP
1090067.
[0017] The term (meth)acrylate here and hereinafter means not only
the esters of methacrylic acid but also the esters of acrylic acid,
and also mixtures of the two. Examples of these monomers are methyl
methacrylate, butyl methacrylate, hydroxyethyl methacrylate, ethyl
acrylate and butyl acrylate.
[0018] The term (meth)acrylate plastisols is used hereinafter to
describe plastisols whose polymeric constituents are composed to a
substantial extent of (meth)acrylates.
[0019] However, these (meth)acrylate plastisols require very high
contents of plasticizers in order to ensure sufficient
processibility. These can evaporate to a limited extent out of the
coating, especially in new vehicles. If these plastisols are used
in vehicle interiors, this leads to an increased level of fogging,
i.e. deposition of these vapours on the windowpanes of the vehicle.
Fogging is undesired and problematic, since it impairs the view
through the windowpanes, especially in sunlight or other types of
glare.
[0020] The object therefore consisted in providing a material for
vibration damping which excludes all of the disadvantages revealed
in the prior art. The object also consisted in improvement of
existing plastisol materials. The intention is to provide
plastisols which comprise less volatile constituents, these being
responsible for fogging.
[0021] These objects, and also other objects which, although not
explicitly stated, are readily deducible or derivable from the
circumstances discussed in the introduction to this specification,
are achieved via a formulation, comprising [0022] a) from 1 to 60%
by weight of oligomers whose molar mass is smaller than 20 000
g/mol, [0023] b) from 0 to 60% by weight of solvents for the
oligomers a), [0024] c) from 5 to 60% by weight of pulverulent
polymers whose molar mass is greater than 100 000 g/mol, and [0025]
d) other fillers, auxiliaries and/or additives, where components a)
to c) make up at least 20% of the formulation. Components a) to c)
preferably make up 40% of the formulation.
[0026] It has been possible to reduce fogging via replacement of
the entire amount, or of a part, of the plasticizer usually used in
plastisols by oligomers, in particular (meth)acrylate
oligomers.
[0027] The inventive formulations have excellent
processibility.
[0028] Surprisingly, it has also been found possible to observe a
marked improvement in the damping properties of the coating.
[0029] The use of (meth)acrylate plastisols meets the requirement
of flexibility in dealing with various surface shapes and
curvatures; another result is optimized stock management of the
damping materials.
[0030] The oligomers a) encompass monomer constitutions which can
not only be composed of various types of monomer but can also
comprise various chain lengths corresponding to the distribution
curves.
[0031] The molar mass M.sub.w of the oligomers a) is <20 000
g/mol, preferably <10 000 g/mol, particularly preferably
<5000 g/mol, and they preferably contain at least 30% by weight
of (meth)acrylates, particularly preferably at least 60% by weight
of (meth)acrylates.
[0032] The oligomers a) have preferably been selected from the
group of the (meth)acrylates, such as alkyl (meth)acrylates of
straight-chain, branched, or cycloaliphatic alcohols having from 1
to 22 carbon atoms, examples being methyl (meth)acrylate, ethyl
(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate,
tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, stearyl
(meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate,
isobornyl (meth)acrylate, aryl (meth)acrylates, such as benzyl
(meth)acrylate or phenyl (meth)acrylate, each of which can be
unsubstituted or can have mono- to tetra-substituted aryl radicals,
mono(meth)acrylates of ethers, of polyethylene glycols, of
polypropylene glycols, or their mixtures having from 5 to 80 carbon
atoms, e.g. tetrahydrofurfuryl methacrylate, methoxy(m)ethoxyethyl
methacrylate, 1-butoxypropyl methacrylate, cyclohexyloxymethyl
methacrylate, benzyloxymethyl methacrylate, furfuryl methacrylate,
2-butoxyethyl methacrylate, 2-ethoxyethyl methacrylate,
allyloxymethyl methacrylate, 1-ethoxybutyl methacrylate,
1-ethoxyethyl methacrylate, ethoxymethyl methacrylate,
poly(ethylene glycol) methyl ether (meth)acrylate, poly(propylene
glycol)methyl ether (meth)acrylate, styrene, and substituted
styrenes, e.g. 4-vinylbenzoic acid.
[0033] The inventive oligomers have to have no reactive groups of
any kind, because their role in the processible form of the
formulation is that of a solvent and their role in the fully gelled
form is that of a binder.
[0034] However, it can be advantageous in specific embodiments to
modify the physical properties of the oligomers, such as the
properties of hydrophilicity or of polarity, via incorporation of
additional functional groups; examples which may be mentioned are
hydroxy groups (e.g. via the use of hydroxyethyl methacrylate or
hydroxypropyl methacrylate as comonomer), acid groups (e.g. via the
use of acrylic acid or methacrylic acid or hydroxypropyl
methacrylate as comonomer) or amide groups (e.g. via the use of
acrylamide or methacrylamide as comonomer).
[0035] Processes known to the person skilled in the art are used to
synthesize the oligomers. They are generally prepared via solution
polymerization using chain transfer agents; typical chain transfer
agents are sulphur compounds, such as mercaptans (e.g.
1-dodecanethiol, 1-butanethiol, etc.). For certain monomers it is
also possible to use catalytic chain transfer agents; examples of
these CCT catalysts are cobalt(II) complexes with porphyrin ligands
or with glyoximine ligands (e.g.
5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphyrin-cobalt (II),
2,3,7,8,12,13,17,18-octa-ethyl-21H,23H-porphyrincobalt (II),
bis[(difluoroboryl)diphenylglyoxime]cobalt(II) or
bis[(difluoroboryl)diphenylglyoxime] cobalt (II)). In the cases
where this is possible the use of catalytic chain-transfer agents
is particularly preferred.
[0036] The formulation can be prepared either with solvents or else
without solvents. Solvents that can be used are liquids or mixtures
of liquids which in the binary mixture with the respective
oligomers in the quantitative proportioning intended in the
respective formulation form an optically clear solution which
exhibits no separation or phase formation even after 24 hours of
standing at 20.degree. C.
[0037] Less preference is given to liquids which in this mixture
with the oligomers exhibit clouding immediately or within 24 hours,
but without any settling or creaming of any of the components, but
they can nevertheless be used in specific embodiments.
[0038] Particular mention may be made of the following solvents,
but the list can be extended as desired and is not to be understood
as limiting:
esters of phthalic acid, e.g. diundecyl phthalate, diisodecyl
phthalate, diisononyl phthalate, dioctyl phthalate, diethylhexyl
phthalate, di-C7-C11-n-alkyl phthalate, dibutyl phthalate,
diisobutyl phthalate, dicyclohexyl phthalate, dimethyl phthalate,
diethyl phthalate, benzyl octyl phthalate, butyl benzyl phthalate,
dibenzyl phthalate, and tricresyl phosphate, dihexyldicapryl
phthalate.
[0039] Hydroxycarboxylic esters, e.g. esters of citric acid (for
example tributyl O-acetylcitrate, triethyl O-acetylcitrate), esters
of tartaric acid or esters of lactic acid.
[0040] Aliphatic dicarboxylic esters, e.g. esters of adipic acid
(for example dioctyl adipate, diisodecyl adipate), esters of
sebacic acid (for example dibutyl sebacate, dioctyl sebacate,
bis(2-ethylhexyl) sebacate) or esters of azelaic acid.
[0041] Esters of trimellitic acid, e.g. tris(2-ethylhexyl)
trimellitate. Esters of benzoic acid, e.g. benzyl benzoate.
[0042] Esters of phosphoric acid, e.g. tricresyl phosphate,
triphenyl phosphate, diphenyl cresyl phosphate, diphenyl octyl
phosphate, tris(2-ethylhexyl) phosphate, tris(2-butoxyethyl)
phosphate.
[0043] Alkylsulphonic esters of phenol or of cresol,
dibenzyltoluene, diphenyl ether.
[0044] Preference is given to use of phthalates, adipates,
phosphates or citrates; particular preference is given to
phthalates.
[0045] Use of volatile solvents, such as low-boiling hydrocarbons
or their mixtures (e.g. petroleum ether) is less preferred but also
certainly advisable in specific embodiments. Use of volatile
solvents is targeted particularly at exterior applications, for
example in underbody protection, where fogging is not relevant.
[0046] The solvents mentioned and other solvents can also be used
in the form of mixtures.
[0047] The molar mass of the polymers c) is usually >100 000
g/mol, preferably >400 000 g/mol. These polymers can by any of
the processes known to the person skilled in the art (e.g.
free-radical polymerization, anionic polymerization, cationic
polymerization, polyaddition or polycondensation). Free-radical
polymerization is preferred.
[0048] Accordingly, it is possible to use monomers--or else
monomers in mixtures--accessible to any of these polymerization
reactions. Preference is given to ethylenically unsaturated
compounds, e.g. (meth)acrylates, styrene and its derivatives,
unbranched or branched alkenes, vinyl esters and other compounds.
(Meth)acrylates are particularly preferred.
[0049] It is preferable to use compounds selected from the group of
the methyl (meth)acrylates, ethyl (meth)acrylates, propyl
(meth)acrylates, isopropyl (meth)acrylates, n-butyl
(meth)acrylates, isobutyl (meth)acrylates, tert-butyl
(meth)acrylates, 2-ethylhexyl (meth)acrylates, hexyl
(meth)acrylates, cyclohexyl (meth)acrylates, pentyl
(meth)acrylates, heptyl (meth)acrylates, octyl (meth)acrylates,
1,4-butanediol (meth)acrylates, 2-butoxyethyl (meth)acrylates,
2-ethoxyethoxymethyl (meth)acrylates, 2-ethoxyethyl
(meth)acrylates, tetrahydrofurfuryl (meth)acrylates,
vinyloxyethoxyethyl (meth)acrylates, methoxyethoxyethyl
(meth)acrylates, 1-butoxypropyl (meth)acrylates,
1-methyl-(2-vinyloxy)ethyl (meth)acrylates, cyclohexyloxymethyl
(meth)acrylates, methoxymethoxyethyl (meth)acrylates,
benzoyloxymethyl (meth)acrylates, furfuryl (meth)acrylates,
2-butoxyethyl (meth)acrylates, 2-ethoxyethoxymethyl
(meth)acrylates, .beta.-carboxyethyl acrylates, 2-ethoxyethyl
(meth)acrylates, allyloxymethyl (meth)acrylates, 1-ethoxybutyl
(meth)acrylates, methoxymethyl (meth)acrylates, 1-ethoxyethyl
(meth)acrylates, ethoxymethyl (meth)acrylates, 2,3-epoxybutyl
(meth)acrylates, 3,4-epoxybutyl (meth)acrylates, glycidyl
(meth)acrylates, 2-(dimethylphosphato)propyl (meth)acrylates,
2-(ethylenephosphito)propyl (meth)acrylates,
dimethylphosphinomethyl (meth)acrylates, dimethylphosphonoethyl
(meth)acrylates, diethyl methacryloylphosphonates, dipropyl
methacryloylphosphates, ethylsulphinylethyl (meth)acrylates,
4-thiocyanatobutyl (meth)acrylates, ethylsulphonylethyl
(meth)acrylates, thiocyanatomethyl (meth)acrylates,
methylsulphinylmethyl (meth)acrylates, bis(methacryloyloxyethyl)
sulphides, trimethyloylpropane tri(meth)acrylates, 1-hexenes,
1-heptenes, cyclohexenes, vinylcyclohexanes, 3,3-dimethylpropenes,
3-methyl-1-diisobutylenes, 4-methyl-1-pentenes, vinyl acetates,
styrenes, .alpha.-methylstyrenes, .alpha.-ethylstyrenes,
vinyltoluenes, p-methylstyrenes, esters or diesters of maleic acid,
9-vinylcarbazoles, 3-vinylcarbazoles, 4-vinylcarbazoles,
vinyloxolanes, vinylfurans, vinylthiophenes, vinylthiolanes.
[0050] It is preferable that at least one of the polymers c) is
composed of more than 60% by weight, particularly preferably more
than 80% by weight, of (meth)acrylates. In one particular
embodiment, each of the polymers c) is composed of more than 60% by
weight, preferably more than 80% by weight, of (meth)acrylates.
[0051] In another preferred embodiment, at least one of the
polymers c) is composed of more than 60% by weight, particularly
preferably more than 80% by weight, of methyl methacrylate.
[0052] The polymers c) are usually composed of more than 60% by
weight of (meth)acrylates.
[0053] For good further processibility, an oligomer a) and/or a
polymer c) can bear one or more functional groups which can give
post-crosslinking. Examples of functional groups that can be used
are hydroxy, mercapto, amino, carboxy, carbonyl, sulphonyl, epoxy,
.beta.-ketoester and isocyanate groups.
[0054] These can, if appropriate, also be present in protected
form, e.g. the isocyanate group reacted with, for example,
alcohols, with phenols, with oximes, with caprolactams, with amines
or with C--H-acidic compounds.
[0055] Hydroxy groups are preferred.
[0056] The polymers can be prepared via emulsion polymerization,
suspension polymerization, solution polymerization or bulk
polymerization. Preparation via emulsion polymerization is
preferred.
[0057] In the case of preparation via emulsion polymerization, the
polymers are produced in the form of polymer particles dispersed in
water. These have to be converted to a dry powder; the usual
methods are suitable for this purpose, examples being coagulation,
spray drying and freeze drying. Spray drying is preferred.
[0058] The preferred preparation process by means of emulsion
polymerization and spray drying gives powder particles whose
average particle diameter is usually from 1 to 500 .mu.m, these
being composed of individual polymer particles whose average
particle diameter is usually from 200 to 1200 nm. Powders of this
type are particularly suitable for preparation of the inventive
formulations.
[0059] (Unless otherwise stated, "average particle diameter" here
and hereinafter means the volume-average of the particle size
distribution of the specimen. These values can be measured by way
of example via laser diffraction, e.g. with the aid of a Coulter LS
13 320 manufactured by Beckmann-Coulter.)
[0060] An emulsion polymerization procedure known to the person
skilled in the art can also prepare polymer particles which have a
core and have one or more shells around the core, and all of the
polymers here which form the core and, respectively, form each of
the shells can have different monomeric constitutions (core/shell
particles).
[0061] A similar method can also be used to prepare particles whose
monomeric constitution changes continuously from the centre of the
particle to its surface, corresponding in some ways to a core-shell
particle with very many shells. In this case another term used is
particles with gradient morphology or "gradient latices".
[0062] As is well known, polymers and oligomers are practically
always composed of mixtures of various molecules, their properties
having a distribution around one or more maxima. An example of
these properties is molecular weight, which is characterized via
average values, the molecular weights of the individual polymer
molecules having a distribution--of varying breadth and also
sometimes polymodal--around this average value.
[0063] Another example relates to chemical constitution. For
example, copolymers (specifically in free-radical polymerization)
are mostly produced via random incorporation of the available
monomers. If, by way of example, a certain monomer A has 2%
presence in a monomer mixture its rate of incorporation into an
oligomer which is composed of an average of 50 monomer units is
statistically once per oligomer. In fact, oligomers without this
monomer A will be found, as will oligomers having 2 or 3 of this
type of monomer unit, than if oligomers having exactly one
incorporated monomer A form the majority.
[0064] The intention here is to make it expressly clear that when
polymers and oligomers are used materials used are always in a
certain sense mixtures, but are not usually perceived and specified
as such. (For better comprehensibility and for demarcation, these
"inevitable" mixtures are termed polymer material and,
respectively, oligomer material in the description
hereinafter).
[0065] However, the expressions "polymers" and "oligomers" in this
specification moreover expressly mean mixtures of a plurality of
polymer materials or of a plurality of oligomer materials: by way
of example, two or more separately prepared materials with
different molecular weight distributions or with different monomer
constitutions can be mixed. Materials used as polymers and,
respectively, oligomers can moreover also comprise those mixed
after they have been obtained by different preparation processes
(e.g. an emulsion polymer and a suspension polymer).
[0066] Polymer particles which have core-shell or gradient
morphology and which have been prepared via emulsion polymerization
are moreover also mixtures of different polymer materials, since
this structure is specifically manifested via different
materials.
[0067] The possibility not only of adjusting the properties of
individual polymer materials or oligomer materials as desired but
also of mixing different materials permitting a targeted approach
to all of the requirements of any specific application.
[0068] The usual fillers, auxiliaries and/or additives can be added
to the formulation.
[0069] Commonly used fillers are inter alia calcium carbonate (in
various versions, e.g. naturally occurring or precipitated,
surface-treated, etc.), barium sulphate (baryte) and silicates,
e.g. mica, bentonites, montmorillonite, talc or vermiculite. Barium
sulphate is particularly preferred.
[0070] Among the auxiliaries and additives are colour pigments,
antioxidants, rheology additives, blowing agents and other
materials.
[0071] Blowing agents are added to the formulations particularly
for the foaming of plastisols. Examples of commonly used blowing
agents are azo compounds (e.g. azodicarbamide), N-nitroso compounds
(e.g. dinitrosopentamethylenetetramine), sulphonyl hydrazides (e.g.
4,4'-oxybis(benzenesulphonic hydrazide)) or sulphonylsemicarbazides
(p-toluenesulphonylsemicarbazides).
[0072] Carbon blacks are often used as colour pigment.
[0073] If appropriate, auxiliaries for post-crosslinking can also
be added. These auxiliaries are generally compounds having two or
more functional groups which form mutual bonds and/or form bonds
with other components of the formulation. For this it can, if
appropriate, be necessary to add an initiator or a catalyst, and/or
to supply energy, for example in the form of heat, UV radiation, or
another form.
[0074] Examples of reactive components that can be used are
hydroxy, mercapto, amino, carboxy, carbonyl, sulphonyl, epoxy,
.beta.-ketoester, isocyanate, and vinyl groups; isocyanates are
preferred.
[0075] These can, if appropriate, also be present in protected
form, e.g. the isocyanate group reacted with, for example,
alcohols, with phenols, with oximes, with caprolactams, with amines
or with C--H-acidic compounds.
[0076] The formulations have a wide field of application and can
advantageously be used wherever the intention is to damp the
vibration of a surface.
[0077] Examples of these applications in private households are the
cladding of household devices, such as washing machines,
refrigerators, kitchen machines and air-conditioning systems, and
also the cladding of personal computers.
[0078] Examples in construction and engineering materials are
pipes, floors and wallcoverings.
[0079] It is readily possible to conceive of a large number of
other applications and application sectors. The surfaces to be
coated can themselves be composed here of various materials, e.g.
plastic, wood, ceramic, cardboard, or chip- and wood-fibre-based
materials. Commonly encountered and particularly preferred surfaces
are sheet metal surfaces.
[0080] Particular preference is given to the coating of bodywork
parts in automobile construction. If the coatings are used
externally in the underbody region and wheel-arch region of the
motor vehicle, noise from impact of stones, sand and water is
reduced, in addition to the damping of the vibrations of the sheet
metal.
[0081] The same formulation can also be used to fill cavities, for
example those occurring in automobile construction, for example in
the roof struts or in A columns, in B columns and in C columns.
Foamable formulations are often used for these applications.
Alongside the damping of vibrations of sheet metal here, onset of
vibration of any air columns included in these cavities is also
prevented.
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