Note: Descriptions are shown in the official language in which they were submitted.
21~S4~1
- Docket: WA 9345-S
Paper No. l
AQUEOUS DISPERSIONS OF ORGANOPOLYSILOXANES
s Field of Invention
The present invention relates to aqueous dispersions of
organopolysiloxanes which can be converted into elastomers after
removal of water, processes for their preparation and their use as
sealing and coating substances.
Backqround of Invention
Environmental protection measures are increasingly forcing
the avoidance of organic solvents in chemical formulations.
Aqueous systems are accordingly being used more and more.
Aqueous dispersions of organopolysiloxanes are known in many
instances. The fundamental build-up of such dispersions, which
vulcanize at room temperature to give elastomers, is composed of a
linear polymer, a crosslinker component and a crosslinking cata-
lyst. In general, an aqueous emulsion of polydiorganosiloxanes,
the end groups of which contain groups which can undergo conden-
sation, is initially introduced into the reaction vessel. These
high molecular weight polysiloxanes are either emulsified directly
or usually prepared in emulsion by polymerization, condensation
and equilibration from linear or cyclic low molecular weight
polysiloxanes by conventional processes. The polymer emulsion is
then mixed with a crosslinker component and condensation catalyst,
in bulk or as an emulsion, as well as further constituents, such
as fillers, adhesion promoters and the like, the catalyst almost
exclusively being torgano)metallic compounds.
The ~organo)metallic catalysts employed have the disadvantage
that they impair the storage stability of the non-vulcanized
4 9 ~
compositions and also the stability of the vulcanized elastomers
~- and they are toxicologically unacceptable. The very involved,
time-consuming and cost-intensive preparation of the aqueous emul-
sions also is a disadvantage of a large number of the developments
to date. These problems result from an emulsion polymerization,
condensation or equilibration of the polydiorganosiloxanes to be
employed, which requires a reaction time and must precede the
preparation of the end product by admixing of the other consti-
tuents. Another disadvantage of most of the aqueous emulsions
known to date lies in the low solids content. However, a high
solids content is a prerequisite for a low or infinitesimal
shrinkage during vulcanization, which is desirable for most fields
of use.
~5 German application P 42 17 561.5 (Wacker-Chemie GmbH) published
December 2, 1993 describes aqueous dispersions of organopolysi-
loxanes comprising organopolysiloxane which can undergo condensa-
tion, silicone resin, polyvinyl alcohol, (organo)metallic catalyst
and amino-functional substances, with which transparent vulcani-
zates are obtained.
U.S. 5,045,231 (Wacker-Chemie GmbH; issued on September 3,
1991) and corresponding DE-A 39 32 025 further claim aqueous dis-
persions of organopolysiloxanes comprising organopolysiloxanes
which can undergo condensation, (organo)metallic catalysts,
organopolysiloxane resins and diorganosilanolates, in which the
solids content of the dispersions can be up to 90%.
DE-B 1037707 (Dow Corning; published on August 28, 1958)
discloses a process for the preparation of emulsions of high
molecular weight organopolysiloxanes starting from an emulsion of
low molecular weight siloxanes. The desired molecular size is
:-'A 2
2136~9~
achieved with the aid of strongly acid or alkaline catalysts.
These emulsions do not lead to elastomers.
U.S. 5,004,771 (Rhône Poulenc; issued on April 2, 1990) and
corresponding EP-A 365 439, disclose acid condensation of a poly-
diorganosiloxane blocked with OH end groups carried out in aqueous
emulsion. After neutralization of the polymer emulsion, the other
constituents, such as methylsiliconate solution and non-silicatic
filler, but not compounds which contain basic nitrogen, are added.
However, the emulsions described, which have a solids content of
less than 90%, do not result in elastomers.
Summary of Invention
The present invention relates to aqueous dispersions of
organopolysiloxanes which are free from organic transition metal
compounds and organic compounds of metals of main group III, IV
and V and can be prepared using the starting substances
(A) organopolysiloxane containing groups which can undergo con-
densation,
(B) organopolysiloxane resin having a molecular weight of not
more than 20,000 and
(C) compounds containing basic nitrogen.
Metals of main group III, IV and V of the Periodic Table are
to include aluminum, gallium, indium, thallium, germanium, tin,
lead, antimony and bismuth.
In the present invention, the term "which can undergo conden-
sation" is also to include any preceding hydrolysis.
The organopolysiloxanes (A) containing groups which can
undergo condensation and are employed according to the invention
are preferably those of the formula
HO-[SiRl2o]n-H (I),
in which
2i36~1
1 is identical or different SiC-bonded hydrocarbon radicals
having 1 to 18 carbon atoms, which are optionally substituted
by halogen atoms, amino groups, ether groups, ester groups,
epoxide groups, mercapto groups, cyano groups or (poly)glycol
radicals, the latter being built up from oxyethylene and/or
oxypropylene units, and
n is an integer of at least 30.
Examples of hydrocarbon radicals R1 are alkyl radicals, such
as the methyl, ethyl, n-propyl, isopropyl, 1-n-butyl, 2-n-butyl,
isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl and tert-
pentyl radical; hexyl radicals, such as the n-hexyl radical;
heptyl radicals, such as the n-heptyl radical; octyl radicals,
such as the n-octyl radical and iso-octyl radicals, such as the
2,2,4-trimethylpentyl radical; nonyl radicals, such as the n-nonyl
radical; decyl radicals, such as the n-decyl radical; dodecyl
radicals, such as the n-dodecyl radical; octadecyl radicals, such
as the n-octadecyl radical; alkenyl radicals, such as the vinyl
and the allyl radical: cycloalkyl radicals, such as cyclopentyl,
cyclohexyl and cycloheptyl radicals and methylcyclohexyl radicals;
aryl radicals, such as the phenyl, naphthyl, anthryl and phen-
anthryl radical; alkaryl radicals, such as o-, m- and p-tolyl
radicals, xylyl radicals and ethylphenyl radicals; and aralkyl
radicals, such as the benzyl radical and the ~- and , ~-phenyl-
ethyl radical.
Examples of substituted hydrocarbon radicals R1 are halo-
genated radicals, such as the 3-chloropropyl radical, the 3,3,3-
trifluoropropyl radical, chlorophenyl radicals and hexafluoro-
propyl radicals, such as the 1-trifluoromethyl-2,2,2-trifluoro-
ethyl radical; the 2-(perfluorohexyl)ethyl radical, the 1,1,2,2-
tetrafluoroethyloxypropyl radical, the 1-trifluoromethyl-2,2,2-
213~491
~ ~ trifluoroethyloxypropyl radical, the perfluoroisopropyloxyethyl
radical and the perfluoroisopropyloxypropyl radical; radicals
substituted by amino groups, such as the N-(2-aminoethyl)-3-amino-
propyl radical, the 3-aminopropyl radical and the 3-(cyclohexyl-
amino)propyl radical; radicals with ether functional groups, such
as the 3-methoxypropyl radical and the 3-ethoxypropyl radical;
radicals with cyano functional groups, such as the 2-cyanoethyl
radical; radicals with ester functional groups, such as the meth-
acryloxypropyl radical; radicals with epoxide functional groups,
such as the glycidoxypropyl radical, and radicals with sulfur
functional groups, such as the 3-mercaptopropyl radical.
Preferred radicals Rl are hydrocarbon radicals having 1 to 10
carbon atoms, more preferably at least 80%, in particular at least
90%, of the radicals R1 being methyl radicals.
The average value for the number n in formula (I) is prefera-
bly chosen such that the organopolysiloxane of formula (I) has a
viscosity of more than 30 mm2/s, more preferably of more than
10,000 mm2/s, in particular of about 80,000 mm2/s, measured at a
temperature of 25~C.
Although not shown in formula (I), up to 10 mole percent of
the diorganosiloxane units can be replaced by other siloxane
units, which are usually present, however, only as impurities
which are more or less unavoidable, such as R13SiOl/2, RlSio3/2
and sio4/2 units, in which Rl has the meaning given above for this
radical.
The polydiorganosiloxanes according to formula (I) can be
prepared by processes known to experts, for example by polymeriza-
tion or condensation of low molecular weight cyclic or linear
organopolysiloxanes blocked with hydroxyl and/or alkoxy end
groups.
213~4~1.
~ The organopolysiloxane (A) containing groups which can under-
-
go condensation which is employed according to the invention can
be a single type or a mixture of at least two types of such
organopolysiloxanes containing groups which can undergo condensa-
tion.
The organopolysiloxane resin (B) having a molecular weight of
not more than 20,000 which is employed according to the invention
is preferably one comprising units of the formula
(R0)eR2asio4_a_e (II),
in which
R2 is identical or different and has one of the meanings given
for Rl,
R is identical or different and is a hydrogen atom or alkyl
radical having 1 to 6 carbon atoms,
a is 0, l, 2 or 3 and
e is 0, 1, 2 or 3, with the proviso that the sum of a and e is
less than or equal to 3 and a and e are on average greater
than 0.
The average value of a is preferably a number between 0.5 and
1.95, in particular between 0.8 and 1.8.
The average value of e is preferably a number between 0.01
and 1, in particular between 0.01 and 0.5.
Although not expressed by formula (II), the organopolysilox-
ane resin can contain up to 10% by weight of Si-bonded chlorine
atoms resulting from its preparation.
Examples of the radical R2 are the examples for hydrocarbon
radicals given for Rl, methyl, ethyl, vinyl and phenyl radicals
being preferred and methyl radicals being more preferred.
2136~
_ Preferred radicals R are the hydrogen atom and alkyl groups
having 1 to 4 carbon atoms, the hydrogen atom and methyl and ethyl
radicals being more preferred.
The organopolysiloxane resin (B) employed according to the
S invention has a molecular weight of preferably not more than
lO,Ooo, more preferably not more than 4,000.
The organopolysiloxane resin (B) employed according to the
invention can be prepared by processes which are known, for exam-
ple, by condensation of low molecular weight organopolysiloxane
resins in dlspersion, it being possible for the low molecular
weight organopolysiloxane resins to be prepared by solvolysis and
condensation of a solution of the corresponding silanes with Si-
bonded chlorine atoms in a water-immiscible solvent by means of an
alcohol/water mixture.
Instead of the organopolysiloxane resin employed according to
the invention as component (B), it is also possible to employ an
organosilane containing groups which can undergo condensation
and/or partial hydrolyzates thereof, although this is not a sub-
ject of the present invention.
Examples of such organosilanes are all the organosilanes
which have been employed previously in organopolysiloxane compo-
sitions which crosslink by condensation, for example, alkoxy-,
acetoxy- and oximosilanes.
To prepare the aqueous dispérsions of organopolysiloxanes,
according to the invention the organopolysiloxane resin (B) is
employed in amounts of preferably 0.1 to 100 parts by weight, more
preferably O.S to 35 parts by weight, in particular 2 to 20 parts
by weight, per 100 parts by weight of organopolysiloxane (A) con-
taining groups which can undergo condensation.
21364~i
._ The organopolysiloxane resin (B) employed according to the
~,_
invention can be a single type or a mixture of such organopoly-
siloxane resins.
The compounds (C) containing basic nitrogen which are
employed according to the invention are preferably those chosen
from the group consisting of compounds of the formula
NR33 (III),
in which
R3 is identical or different and is a hydrogen atom or hydrocar-
bon radicals, which are optionally substituted by hydroxyl
groups, halogen atoms, amino groups, ether groups, ester
groups, epoxide groups, mercapto groups, cyano groups or
(poly)glycol radicals, the latter being built up from oxy-
ethylene and/or oxypropylene units,
with the proviso that in formula (III) not more than two R3
are hydrogen atoms,
aliphatic cyclic amines, for example, piperidine and
- morpholine,
and organosilicon compounds having at least one organic
radical containing basic nitrogen, comprising units of the
formula
R4bYCsi(OR5)dO4-b-c-d (IV),
in which
R4 is identical or different and is a monovalent, SiC-bonded
organic radical which is free from basic nitrogen,
R5 is identical or different and is a hydrogen atom, an alkyl
radical, an alkali metal cation, or an ammonium or phospho-
nium group,
Y is identical or different and is a monovalent, SiC-bonded
radical containing basic nitrogen,
21364~1
b is 0, 1, 2 or 3,
c is 0, 1, 2, 3 or 4 and
d is 0, 1, 2 or 3,
with the proviso that the sum of b, c and d is less than or equal
s to 4 and at least one radical Y is present per molecule.
The optionally substituted hydrocarbon radicals R3 are pref-
erably those having 1 to 18 carbon atoms.
The radical R4 is preferably a hydrocarbon radical having 1
to 18 carbon atoms, the methyl, ethyl and propyl radical being
more preferred, in particular the methyl radical.
Examples of the radical R3 and R4 are independent of each
other the examples for hydrocarbon radicals given for R1.
The radical R5 is preferably a hydrogen atom, methyl or ethyl
radical or alkali metal cation, the hydrogen atom, methyl or ethyl
radical or sodium and potassium cation being more preferred.
Examples of the radical RS are the hydrocarbon radicals given
for radical R, the alkali metal cations, such as those of lithium,
sodium, potassium, rubidium and cesium, and radicals of the
formula
+NR64 (V)
or
+PR64 (VI),
in which
R6 is identical or different and is a hydrocarbon radical having
1 to 6 carbon atoms.
The radicals Y are preferably those of the formula
R72NR8- (VII),
in which
R7 is identical or different and is hydrogen or alkyl, cyclo-
alkyl or aminoalkyl radicals and
R8 is a divalent hydrocarbon radical.
21364~1
The examples of alkyl and cycloalkyl radicals R1 also apply
in their full scope to alkyl and cycloalkyl radicals R7.
Preferably, at least one hydrogen atom is bonded to each
nitrogen atom in the radicals of formula (VII).
The radical R8 is preferably a divalent hydrocarbon radical
having 1 to 10 carbon atoms, more preferably 1 to 4 car~on atoms,
in particular the n-propylene radical.
Examples of the radical R8 are the methylene, ethylene,
propylene, butylene, cyclohexylene, octadecylene, phenylene and
butenylene radical.
Examples of radicals Y are
~2N(cH2)3
H2N(C~2)2NH(C~2)2-~
H2N(CH2)2NH(Ca2)3-
H2N(C~2)2-~
H3CN~(CH2)3-~
C2H5NH(Ca2)3-r
H?CNH(CH2)2-~
C2~I5NH ( C~2 ~ 2-
H2N(C~2) 4-~
H2N(C~2) s~~
H(NHCH2C~2)3-~
C4H,N~(CH2)2NH(C~)2-
cyclo-CsH.lNH(CH,) 3 -,
cyclo-Cs~,,,,NH ( C~2 ) 2- /
(c~)2N(c~2)3
(C~.)2N(C~2)2-~
(C2~s)2N(cH2)3- and
(C2~5)2N(C~2)i--
Y is preferably H2N(CH2)3-, H2N(cH2)2NH(cH2)3-l H3CNH(CH2)3_
C2H5NH(CH2)3- and cyclo-C6H11NH(CH2)3- where H2N(CH2)2NH(CH2)3-
and cyclo-C6Hl1NH(CH2)3- being more preferred.
If the organosilicon compounds consisting of units of formula
(IV) are silanes,
21364~
~~ b is preferably O, 1 or 2, more preferably O or l,
c is preferably 1 or 2, more preferably 1, and
d is preferably 1, 2 or 3, more preferably 2 or 3,
with the proviso that the sum of b, d and d is 4.
Examples of the silanes of formula (IV) according to the
invention are
H2N(CH2)3-Si(OcH3)3
H2N(CH2)3-Si(Oc2H5)3
E2N ( C~2 ) 3-Si ( OC}Il ) 2Cgl
E~2N( CH2 ) 3-Si ( ~C2~ ) 2cg~
H2N(C~I2) 3-Si(o~) 3_S~ON)~
H2N ( cg2 ) 3-Si ( OH) 2-y ( OM! yC~5~
H2N(CH2)2NH(Cg2) 3-Si(OCg3) 3
H2N(CH2)2N~I(cg2)3-Si(oc~g~)3
H2N ( CH2 ) 2N~ ( CH2 ) 3-Si ( ~C~ ) 2cg3
H2N ( CH2 ) 2NH ( C~2 ) 3-si ( OC2gs ) 2C~3
~2N(C~2),N~(C~2)3-Si(O~) 3_~(0M)~
H2N ( CH2 ) 2NH ( Cg~ ) 3-Si ( OH ) 2-y ( OM~ yC~3
CyC10-C5~llNH ( C~2 ) 3-Ci ( OC~ ) 3
cyclo-C6HllNH ( cg2 ) 3-si ( 0C2E~ ) 3
CyClO-C5gllN~ ( CH2 ) 3-Si ( OC~ C~I3
cyclo-C6gllNH ( cg2 ) 3-~ii ( ~C2~ ) 2CH3
cyclo-C6HllNH(CH2) 3 - 5 i ( ~~ ~ 3.S ~OM)s and
CyClO-C6~llNH(Cg2) 3-Si( OH)~y(OM) yC~I3
where
H2N(cg2)2N~(c~2) 3-Si(ocg7) 3
H2N ( C~2 ) 2N~I ( C~12 ) ,-Si ( OC. 5 ) 3
EI2N ( CH2 ) 2NH ( C~2 ) 3-Si ( 0C~3 ) 2
H2N(C~2)~NH ( C~2 ) 3-Si ( 0c2g~ ) 2cg3
H2N(CH2)2NH(CH2)3-Si(OH)3-xtoK)x
H2N(CH2)2NH(cH2)3-si(oH)2-y(oK)ycH3
cyclo-CsH~lNH(cg2) 3-_ i ( OCg- ) 3
cycio-Cs~l~NH ( C~. ) 3-Si ( OC2~. ) 3
CyClO-C5HllNH ( cg2 ) 3-'~i ( 0Cg3 ) 2cg3
cyclo-CSHllN~ ( Cg. ) 3-S i ( ~C2~ ) 2C~3
cyclo-c6HllNH(cH2)3-si(oH)3-x(oK)x and
2136~91
cyclo-C6HllNH(CH2)3-Si(OH)2_y(0K)yCH3 are preferred and
_
~2N ( C~2 ) 2N~ ( C~2 ) 3-Si ( OC~3 ) 3
~2N ( C~2 ) 2~ ( C~2 ) 3-Si(OC~3)2CH3
cyclo-C6H~lNE(C~2)3-Si(OCH3)3
cyclo-C5~llN~(C~.)3-Si(OCE3)2C~3
H2N(cH2)2NH(cH2)3si(oH)3-x(oK)x and
H2N(cH2)2NH(cH2)3-si(OH)2-y(OK)yCH3
are particularly preferred, where
x is 0, 1, 2 or 3,
y is 0, 1 or 2 and
M is the cation of sodium or potassium.
Silanes of formula (IV) are commercially available products
and can be prepared by processes customary in silicon chemistry.
If the organosilicon compound consisting of units of formula
(IV) is an organopolysiloxane, the average value of b is prefera-
bly between 0.5 and 2.5, more preferably between 1.4 and 2.0, the
average value of c is preferably between 0.01 and 1.0, more pref-
erably between 0.01 and 0.6, and the average value of d is prefer-
ably between o and 2.0, more preferably between O and 0.2, with
the proviso that the sum of b, c and d is less than or equal to 3.
The organopolysiloxanes consisting of units of formula (IV)
employed according to the invention have a viscosity at 25~C of
preferably 5 to 105 mm2/s, more preferably 10 to 104 mm2/s.
Examples of the organopolysiloxanes consisting of units of
formula (IV) are
H2N(CH2)2NH(fH2)3
(cH3)3sio[(cH3)2sio]k[cH3sio]msi(cH3)3 (IVa)
and
cyclo-C6H11NH(lCH2)3
(cH3)3sio[(cH3)2sio]k[cH3sio]msi(cH3)3 (IVb)
in which the ratio of k to m is between 2:3 and 9:1 and the sum of
k and m is between 10 and 1000, and
H2N(CH2)2NH(fH2)3
[(CH3)2SiO]O[Sio3/2]p[(cH3)3siol/2]r (IVc)
213~191
i- and
cyclo-C6Hl1NH(CH2)3
t(CH3)2SiO]O[SiO3/2]p[(CH3)3SiOl/2]r (IVd),
in which the sum of o+p+r is between lO and lOO0, the ratio of
o:(o+p+r) is between 0 and 0.9, in particular between 0.2 and 0.7,
the ratio of p:(o+p+r) is between 0.05 and 0.6, in particular
between 0.1 and 0.5, and the ratio of r:(o+p+r) is between 0.05
and 0.75, in particular between 0.2 and 0.6
Organopolysiloxanes consisting of units of formula (IV) are
commercially available products and can be prepared by processes
customary in silicon chemistry.
Examples of amines of formula (III) are cyclohexylamine,
triethylamine, dodecylamine, diethyl-n-propylamine, cyclohexyl-
methylamine, 2-aminoethanol, 2-amino-n-propanol, 2-amino-2-methyl-
1-propanol, 2-dimethylamino-2-methyl-1-propanol, N,N-diethyl-
ethanolamine, ethylenediamine, coconut fatty amine, coconut fatty
methylamine, N,N-dimethylethanolamine and aniline.
organosilicon compounds having at least one organic radical
containing basic nitrogen consisting of units of formula (IV), in
particular potassium N-(2-aminoethyl)-3-aminopropylmethylsilano-
late and sodium N-(2-aminoethyl)-3-aminopropylmethylsilanolate,
are preferably employed as component (C).
The compound (C) containing basic nitrogen which is employed
according to the invention can bè a single type or a mixture of at
least two types of such compounds.
To prepare the aqueous dispersions of organopolysiloxanes,
according to the invention component (C) is employed in an amount
such that the content of basic nitrogen is preferably 0.01 to 5
parts by weight, more preferably 0.01 to 1 part by weight, in
particular 0.04 to 0.5 part by weight, per 100 parts by weight of
2136~1
'~ organopolysiloxane (A) containing groups which can undergo conden-
_
sation.
The aqueous dispersions of organopolysiloxanes according to
the invention are in general stabilized by emulsifiers (D).
Cationic, anionic, ampholytic and nonionic emulsifiers can be
used. These emulsifiers and their metering are sufficiently known
in the art. One type of emulsifier, for example an anionic emul-
sifier, or mixtures of at least two types of emulsifiers, for
example a mixture of at least one anionic with at least one non-
ionic emulsifier, can be used.
The emulsifiers (D) can be added to the mixture to be dis-
persed or to be stabilized as a dispersion, and they can also be
formed from a precursor, for example the corresponding acid or
base or a salt of the actual emulsifier, by chemical reaction(s)
in the mixture to be dispersed or to be stabilized as a disper-
sion.
The anionic emulsifiers are preferably the salts of the
surface-active sulfonic acids used in the emulsion polymerization
to form the organopolysiloxane (A) containing groups which can
undergo condensation, according to U.S. 3,294,725 (D.E. Findley,
Dow Corning Corp.; issued on December 27, 1966), where the
surface-active sulfonic acids and salts thereof are mentioned.
The alkali metal or ammonium salts of the sulfonic acids are
preferred, in particular the natrium salts.
Examples which may be mentioned of the sulfonic acids are
aliphatically substituted benzenesulfonic acids, aliphatically
substituted naphthalenesulfonic acids, aliphatic sulfonic acids,
silylalkylsulfonic acids and aliphatically substituted diphenyl-
ether-sulfonic acids.
2136~1
Furthermore, alkali metal sulforicinoleates, sulfonated
glycerol esters of fatty acids, salts of sulfonated monovalent
alcohol esters, amides of aminosulfonic acids, such as the sodium
salt of oleylmethyltauride, alkali metal salts of sulfonated
aromatic hydrocarbons, such as sodium ~-naphthalene-monosulfonate,
and condensation products of naphthalenesulfonic acids with form-
aldehyde and sulfates, such as ammonium lauryl sulfate,
triethanolamine lauryl sulfate and sodium lauryl ether-sulfate,
can also be used as anionic emulsifying agents.
Nonionic emulsifiers are preferably used in addition to
anionic emulsifier. Examples of such nonionic emulsifiers are
saponins, addition products of fatty acids with ethylene oxide,
such as dodecanoic acid esters with tetraethylene oxide, addition
products of ethylene oxide with sorbitan trioleate, addition
products of phenolic compounds having side chains with ethylene
oxide, such as addition products of ethylene oxide with isodo-
decylphenol, and imine derivatives, such as polymerized ethyl-
eneimine, and addition products of alcohols with ethylene oxide,
such as polyethylene glycol (10)-isotridecyl ether.
Examples of cationic emulsifiers are salts of fatty amines,
quaternary ammonium compounds and quaternary compounds of pyri-
dine, morpholine and imidazoline.
Examples of ampholytic emulsifiers are long-chain substituted
amino acids, such as N-alkyldi(aminoethyl)-glycine, N-alkyl-2-
aminopropionate, and betaines, such as (3-acylaminopropyl)di-
methylglycine and alkylimidazolium betaine.
Water-soluble polymers which are described as being suitable
for stabilizing dispersions, for example, polyvinyl alcohols,
polyvinylpyrrolidones, polyvinyl sulfates, polyacrylates, poly-
acrylamides and malonic acid/styrene copolymers, or else poly-
~136 l9~.
saccharides, can also be employed as emulsifiers for the prepara-
tion of dispersionsaccording to the invention.
If an emulsifier (D) is employed, preferred emulsifiers are
anionic emulsifiers, nonionic emulsifiers and mixtures thereof,
more preferably alkali metal salts of organosulfonic acids,
organopolyglycol ethers and polyvinyl alcohols.
An emulsifier (D) is preferably employed for the preparation
of the aqueous dispersions of organopolysiloxanes according to the
invention.
The amount of emulsifier which is advantàgeous for stabili-
zing the aqueous dispersions of organopolysiloxanes according to
the invention depends greatly on the composition of the particular
dispersion. In general, 0.5 to 10 parts by weight of emulsi-
fier(s) are sufficient per 100 parts by weight of organopolysilox-
ane (A) containing groups which can undergo condensation.
The aqueous dispersions of organopolysiloxanes according to
the invention can also contain fillers (E).
Examples of fillers (E) are nonreinforcing fillers, or
fillers having a BET surface area of up to 50 m2/g, such as
quartz, diatomaceous earth, calcium silicate, zirconium silicate
and zeolites, metal oxide powders, such as aluminum, titanium,
iron or zinc oxides and mixed oxides thereof, barium sulfate, cal-
cium carbonate, gypsum, silicon nitride, silicon carbide, boron
nitride and powders of glass and plastics; reinforcing fillers,
having a BET surface area of more than 50 m2/g, such as pyrogeni-
cally prepared silicic acid, precipitated silicic acid, carbon
black, such as furnace black and acetylene black, and silicon/
aluminum mixed oxides of high BET surface area; and fibrous
fillers, such as asbestos and fibres of plastic. The fillers
mentioned can be rendered hydrophobic, for example by treatment
213~91
with organosilanes or organosiloxanes or by etherification of
hydroxyl groups to alkoxy groups.
If fillers (E) are employed, the amounts are preferably 0.1
to 200 parts by weight, more preferably 0.5 to 100 parts by
weight, per 100 parts by weight of organopolysiloxane (A) con-
taining groups which can undergo condensation. The amount of
filler (E) employed can be varied within wide limits and depends
especially on the particular intended use of the dispersions
according to the invention.
The aqueous dispersions of organopolysiloxanes according to
the invention can also contain additives (F), preferably chosen
from the group consisting of adhesion promoters, plasticizers,
foam prevention agents, thixotropic and dispersing agents, pig-
ments, soluble dyestuffs, fungicides, odoriferous substances and
organic solvents which are inert with respect to the dispersions.
Examples of adhesion promoters, may be added to improve the
adhesion of the elastomeric products, obtained from the aqueous
dispersions according to the invention after removal of their
solvent contents, to the substrate to which the dispersions
according to the invention have been applied, are silanes contain-
ing amino functional groups, such as N-(2-aminoethyl)-3-amino-
propyltrialkoxysilanes, in which the alkoxy radical is a methoxy,
ethoxy, n-propoxy or isopropoxy radical.
Examples of plasticizers are dimethylpolysiloxanes which are
liquid at room temperature and blocked by trimethylsiloxy end
groups and have a viscosity of at least 10 mm2/s.
Examples of organic solvents which are inert with respect to
the dispersions are hydrocarbons, such as petroleum ether having
various boiling ranges, n-pentane, n-hexane, a hexane isomer
mixture, toluene and xylene.
2136~91
Examples of thixotropic agents are carboxymethylcellulose and
polyvinyl alcohol.
Examples of dispersing agents are polyacrylic acid salts and
polyphosphates.
The thixotropic and dispersing agents mentioned in some cases
also have emulsifying properties, so that they can be used as
emulsifiers.
From each of the groups of substances mentioned above as
possible components for the aqueous dispersions according to the
invention, it is possible to use one substance of this group as a
component or a mixture of at least two different substances of
this group.
The aqueous dispersions of organopolysiloxanes according to
the invention preferably have a pH from 5 to 13, more preferably
from 6 to 11.
Solids contents of up to 95% by weight can be achieved in the
aqueous dispersions of organopolysiloxanes according to the inven-
tion. Lower solids contents are of course possible. A solids
content of more than 90% can be achieved even in aqueous silicone
dispersions according to the invention which contain no fillers.
The solids content here is to be understood as meaning the weight
content of all the constituents of the dispersion apart from water
and, if used, organic solvent with respect to the total weight of
the dispersion.
The aqueous dispersions of organopolysiloxanes according to
the invention can be dimensionally stable or free-flowing, depend-
ing on their use.
The organosiloxane dispersions according to the invention are
preferably those which are prepared using components (A), (B),
(C), (D), water and optionally (E) and (F). Other substances are
preferably not employed.
18
2136~91
"- The aqueous dispersions according to the invention can in
._
principle be prepared by any desired processes which are known to
date.
Process 1 which comprises mixing all the constituents of the
dispersion apart from the filler (E) with one another and dis-
persing them together results as a considerably simplified and
therefore economic preparation procedure from the combination
according to the invention of the aqueous dispersions of organo-
polysiloxanes. Thereafter, optionally, the filler (E) can be
incorporated immediately into the dispersion.
In process 2, all the constituents of the dispersion, apart
from component (C) and filler (E), are mixed with one another and
dispersed together. Thereafter, component (C) and optionally,
filler (E) are incorporated into the dispersion.
The dispersions according to the invention are preferably
prepared by process 2.
The emulsification or dispersion operation can be carried out
in customary mixing apparatuses which are suitable for the prepa-
ration of emulsions and dispersions, for example, high-speed
stator-rotor stirred apparatuses according to Prof. P. Willems,
known by the registered trade mark "Ultra-Turrax". In this con-
text, reference may also be made to Ullmanns Encyklopadie der
Technischen Chemie (Ullmann's Encyclopedia of Industrial Chemis-
try), Urban & Schwarzenberg, Munich, Berlin, 3rd ed. vol. 1, page
720 et seq.
The dispersion according to the invention can of cour~e also
be prepared in another manner. However, it has been found that
the procedure is critical and not all types of preparation give
dispersions which lead to elastomers after removal of water.
2136~91
The processes according to the invention disclosed herein
have the advantage that they are very easy to carry out and
aqueous dispersions having very high solids contents can be pre-
pared.
The processes according to the invention furthermore have the
advantage that the individual constituents of the aqueous disper-
sion of organopolysiloxanes can be employed without pretreatments,
in particular the condensation of the polyorganosiloxane component
before emulsification which is often described and the condensa-
tion of the silicone resin component are omitted.
The processes according to the invention thus have the
advantage that the aqueous dispersions can be prepared in a single
working operation without having to allow for maturing times
during the preparation, which would make the preparation process
complicated and slow it down.
The process according to the invention can be carried out
discontinuously or continuously.
The aqueous dispersions according to the invention have the
advantage that they are free from organic transition metal comp-
ounds and organic compounds of metals of main group III, IV and V,
by which among other things a high stability is caused. The
aqueous dispersions according to the invention are preferably
storage-stable over a period of at least several years at room
temperature and atmospheric pressure.
The aqueous dispersions of organopolysiloxanes according to
the invention can be employed for all purposes for which aqueous
dispersions of organopolysiloxanes have previously been used.
They can be used, for example, as sealing compositions, paints and
coating systems and as electrically insulating or conductive,
hydrophobic nonstick coating systems, or as a base or additives
for such systems.
2136'1~1
'~ The aqueous dispersions of organopolysiloxanes according to
the invention cure even at room temperature within a short time
after evaporation of the solvent content, that is of the water and
optionally organic solvent, to give elastomers.
The aqueous dispersions according to the invention, in parti-
cular those which have been prepared using polyvinyl alcohols,
have the advantage that they cure in thin layers to give trans-
parent elastomers.
The aqueous dispersions according to the invention have the
further advantage that they form firmly adhering coatings on many
substrates, such as paper, textiles, mineral building materials,
plastics, wood and many other substrates. Coating can be carried
out by brushing, rolling, dipping or spraying.
A preferred application is as sealing compositions and coat-
ing materials. Examples which may be mentioned are joint sealing
compositions for facades and buildings and window glazing, as well
as the use as sealing compositions in the sanitary sector. Exam-
ples of coatings are, inter alia, facade coatings and impregna-
tions, elastic masonry paints and textile and fabric coatings.
In the examples described below, all the parts and percentage
data relate to the weight, unless stated otherwise. Furthermore,
all the viscosity data are based on a temperature of 25~C. Unless
stated otherwise, the following examples are carried out under the
pressure of the surrounding atmosphere, that is about 1000 hPa,
and at room temperature of about 22~C, or a temperature which is
established when the reactants are brought together at room tem-
perature without additional heating or cooling.
The amine number corresponds numerically to the value which
indicates the consumption in ml of 1 N HCl on neutralization of
1 g of organosilicon compound containing amino functional groups.
21
~ ~ 3~4~ ~
The elastomer properties are determined in accordance with
~~ the following standardized tests:
Tear strength : DIN 53504-85S1
Elongation at break : DIN 53504-85S1
Modulus : DIN 53504-85Sl
Shore A : DIN 53505-87
Tear propagation resistance : ASTM D624B-73
Example 1
(I) Preparation of an aqueous solution of potassium N-(2-amino-
ethyl)-3-aminopropylmethylsilanolate
103 g of N-(2-aminoethyl)-3-aminopropylmethyldimethoxy-
silane (commercially obtainable under the name "SilanTM GF 95"
from Wacker-Chemie GmbH, Munich) are metered into a solution
of 63.7 g of potassium hydroxide (88% strength in water) in
200 g of water, while stirring vigorously. First methanol
and then about 70 g of water are distilled off from the
mixture by heating. The mixture is then topped up to a total
weight of 317 g by addition of water to give a 40% strength
potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
solution.
323 g of ~,~-dihydroxypolydimethylsiloxane having a visco-
sity of 80,000 mm2/s, 16 g of organopolysiloxane resin of the
average formula [(CH3)2Siol/2]1.1[Sio2] having an average
molecular weight of 2000 and an average ethoxy content of
2.1~ by weight, based on the resin molecule, and 17 g of
organopolysiloxane resin of the average formula
[(CH3)2siO]o.2[(cH3)sio3/2]o.g having an average molecular
weight of 3000 and an average ethoxy content of 2.6% by
weight, based on the resin molecule, are mixed together with
30 g of a 75% strength aqueous sodium dodecylbenzenesulfonate
~ 22
solution (commercially obtainable under the name MarlonTM A
375" from Huls) and 50 g of water and the mixture is con-
verted into an emulsion with the aid of an Ultra-Turrax
mixer. After 4 g of the aqueous solution of potassium
N-(2-aminoethyl)-3-aminopropylmethylsilanolate described
under (I) and 219 g of precipitated chalk have been added, a
creamy-soft, smooth, permanently homogeneous dimensionally
stable composition having a solids content of 91% and a pH of
10.5 is obtained and is introduced into cartridges under air-
tight conditions. The properties of the dispersion stored in
this way are unchanged over a period of more than 1 year.
Films 2 mm thick are produced from the resulting disper-
sion of organopolysiloxanes by applying the aqueous disper-
sion to a surface of polytetrafluoroethylene (PTFE) and
allowing the water to evaporate at room temperature. Two
weeks after the application, dry, elastic films are formed,
and these are investigated for their elastomer properties.
Data on the elastomer properties are to be found in Table 1.
Example 2
The procedure described in Example 1 is repeated, with the
modification that instead of 30 g of a 75% strength aqueous
sodium dodecylbenzenesulfonate solution, 28 g of an 80%
strength aqueous solution of polyethylene glycol 10-isotri-
decyl ether (commercially obtainable under the name Arylpon TM
IT 10" from Grunau) are employed. After 219 g of precipi-
tated chalk have been added, a creamy-white, smooth, perma-
nently homogeneous dimensionally stable composition having a
solids content of 91% and a pH of 10.0 is obtained and is
introduced into cartridges under air-tight conditions. The
properties of this dispersion stored in this way are
A
23 ~
unchanged over a period of more than 1 year. Data on the
-~ elastomer properties are to be found in Table 1.
Example 3
The procedure described in Example 1 is repeated, with the
modification that instead of 30 g of a 75% strength aqueous
sodium dodecylbenzenesulfonate solution, 30 g of a mixture of
a 75% strength aqueous sodium dodecylbenzenesulfonate solu-
tion and an 80% strength aqueous solution of polyethylene
glycol 10-isotridecyl ether (commercially obtainable under
the name "Arlypon IT 10" from Grunau) are employed. After
219 g of precipitated chalk have been added, a creamy-white,
smooth, permanently homogeneous dimensionally stable
composition having a solids content of 91% and a pH of 10.0
is obtained and is introduced into cartridges under air-tight
conditions. The properties of this dispersion stored in this
way are unchanged over a period of more than 1 year. Data on
the elastomer properties are to be found in Table l.
Example 4
The procedure described in Example 1 is repeated, with the
modification that instead of 30 g of a 75% strength aqueous
sodium dodecylbenzenesulfonate solution, 30 g of an 80%
strength aqueous solution of polyethylene glycol (18)-phenol
(commercially obtainable under the name Sapogenat TM T-180"
from Hoechst) are employed in a ratio of 1:3. After 219 g of
precipitated chalk have been added, a creamy-soft, smooth,
permanently homogeneous dimensionally stable composition
having a solids content of 91% and a pH of 10.0 is obtained
and is introduced into cartridges under air-tight conditions.
The properties of this dispersion stored in this way are
24
4 ~ ~ C
unchanged over a period of more than 1 year. Data on the
'~- elastomer properties are to be found in Table 1.
Example 5
200 g of ~ dihydroxypolydimethylsiloxane having a visco-
sity of 80,000 mm2/s, 12 g of organopolysiloxane resin with
the average formula [(CH3)2Siol/2]l.l[Sio2] having an average
molecular weight of 2000 and an average ethoxy content of
2.1% by weight, based on the resin molecule, 6 g of organo-
polysiloxane resin with the average formula
[(CH3)2siO]o.2[(cH3)sio3/2]o.g having an average molecular
weight of 3000 and an average ethoxy content of 2.6% by
weight, based on the resin molecule, and 10 g of polydi-
methylsiloxane with 3-(2-aminoethylamino)propyl functional
groups having a viscosity of 1000 mm2/s and an amine number
of 0.3 (commercially obtainable under the name "Finish W RTM
1300" from Wacker-Chemie GmbH) are mixed together with 50 g
of a 10% strength aqueous solution of a polyvinyl alcohol
having a molecular weight of 85,000 and a hydrolysis number
of 240 (commercially obtainable under the name Polyviol WTM
30/240" from Wacker-Chemie GmbH) and the mixture is converted
into an emulsion with the aid of an Ultra-Turrax mixer.
After 2 g of the aqueous solution of potassium N-(2-amino-
ethyl)-3-aminopropylmethylsilanolate described in Example 1
under (I)) have been added, a white, creamy-soft, smooth,
permanently homogeneous dimensionally stable composition
having a solids content of 84% and a pH of 8.0 is obtained
and is introduced into cartridges under air-tight conditions.
The properties of this dispersion stored in this way are
unchanged over a period of more than 1 year. The vulcanized
product is transparent.
~ 25
2136~91
Transparent films 2 mm thick are produced from the
resulting dispersion of organopolysiloxanes by applying the
aqueous dispersion to a surface of polytetrafluoroethylene
(PTFE) and allowing the water to evaporate at room tempera-
ture. Two weeks after the application, dry, elastic films
are formed, and are investigated for their elastomer proper-
ties. Data on the elastomer properties are to be found in
Table 1.
Example 6
(II) Preparation of an aqueous solution of potassium N-(2-amino-
ethyl)-3-aminopropylsilanolate
111 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane
(commercially obtainable under the name "Silan GF 91" from
Wacker-Chemie GmbH, Munich) are metered into a solution of
95.5 g of potassium hydroxide in 400 g of water, while stir-
ring vigorously. First methanol and then about 200 g of
water are distilled off from the mixture by heating. The
mixture is then topped up to a total weight of 367 g by addi-
tion of water to give a 40% strength potassium N-(2-amino-
ethyl)-3-aminopropylsilanolate solution.
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl?-3-aminopropylmethylsilanolate
described under I), 4 g of the aqueous solution of potassium
N-(2-aminoethyl)-3-aminopropylsilanolate described above
under II) are employed. After 219 g of precipitated chalk
have been added, a creamy-soft, smooth, permanently homoge-
neous dimensionally stable composition having a solids con-
tent of 91% and a pH of 10.5 is obtained and is introduced
into cartridges under air-tight conditions. The properties
26
of this dispersion stored in this way are unchanged over a
~ period of more than 1 year. Data on the elastomer properties
are to be found in Table I.
Example 7
The procedure described in Example l is repeated, with the
modification that instead of 4 g of the aqueous solution of
potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 5 g of potassium N-(2-aminoethyl)-3-
aminopropyltrimethoxysilane (commercially obtainable under
the name "Silan GF 91" from Wacker-Chemie GmbH) are employed.
After 219 g of precipitated chalk have been added, a creamy-
soft, smooth, permanently homogeneous dimensionally stable
composition having a solids content of 91% and a pH of 9.5 is
obtained and is introduced into cartridges under air-tight
conditions. The properties of this dispersion stored in this
way are unchanged over a period of more than l year. Data on
the elastomer properties are to be found in Table 1.
Example 8
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 10 g of polydimethylsiloxane with
3-(cyclohexylamino)propyl functional groups having a viscosi-
ty of 200 mm2/s and an amine number of 2.5 (commercially
obtainable under the name "Haftvermitt1erTM A MS 61"from
Wacker-Chemie GmbH) are employed. After 219 g of precipi-
tated chalk have been added, a creamy-soft, smooth, perma-
nently homogeneous dimensionally stable composition having a
solids content of 91% and a pH of 9.0 is obtained and is
introduced into cartridges under air-tight conditions. The
27
213S4~1
"~,
properties of this dispersion stored in this way are
,.,._
unchanged over a period of more than 1 year. Data on the
elastomer properties are to be found in Table 1.
Example 9
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 5 g of diethylamine are employed. After
219 g of precipitated chalk have been added, a creamy-soft,
smooth, permanently homogeneous dimensionally stable composi-
tion having a solids content of 91% and a pH of 9.5 is
obtained and is introduced into cartridges under air-tight
conditions. The properties of this dispersion stored in this
way are unchanged over a period of more than 1 year. Data on
the elastomer properties are to be found in Table 1.
Example 10
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 10 g of coconut fatty amine (commercially
obtainable under the name "Genamin CC 100 D" from Hoechst)
are employed. After 219 g of precipitated chalk have been
added, a creamy-soft, smooth, permanently homogeneous dimen-
sionally stable composition having a solids content of 91%
and a pH of 10.0 is obtained and is introduced into car-
tridges under air-tight conditions. The properties of this
dispersion stored in this way are unchanged over a period of
more than 1 year. Data on the elastomer properties are to be
found in Table l.
28
2136~9~
Comparison Example 1
,_
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 4 g of a 42% strength aqueous solution of
potassium methyl silanolate (commercially obtainable under
the name "BS 15" from Wacker-Chemie GmbH) are employed.
After 219 g of precipitated chalk have been added, a creamy-
soft, smooth, dimensionally stable composition having a
solids content of 91% and a pH of 10.0 is obtained and is
introduced into cartridges under air-tight conditions. The
dispersion of organopolysiloxanes prepared in this manner
does not vulcanize to an elastomer even after a maturing or
storage time of 2 months. After release of the water, an
oily, viscous composition results. After storage for three
months, the dispersion demixes.
Comparison Example 2
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 4 g of a 30% strength aqueous KOH solu-
tion are employed. After 219 g of precipitated chalk have
been added, a creamy-soft, smooth, dimensionally stable
composition having a solids content of 91% and a pH of 10.5
is obtained and is introduced into cartridges under air-tight
conditions. The dispersion of organopolysiloxanes prepared
in this manner does not vulcanize to an elastomer even after
a maturing or storage time of 2 months. After release of the
water, an oily, viscous composition results.
Comparison Example 3
~- The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 4 g of a 30~ strength aqueous benzyltri-
ammonium hydroxide solution are employed. After 219 g of
precipitated chalk have been added, a creamy-soft, smooth,
dimensionally stable composition having a solids content of
90% and a pH of 9.0 is obtained and is introduced into
cartridges under air-tight conditions. The dispersion of
organopolysiloxanes prepared in this manner does not
vulcanize to an elastomer even after a maturing or storage
time of 2 months. After release of the water, an oily,
viscous composition results.
Comparison Example 4
The procedure described in Example 1 is repeated, with the
modification that instead of the 4 g of the aqueous solution
of potassium N-(2-aminoethyl)-3-aminopropylmethylsilanolate
described under I), 2 g of dodecylbenzenesulfonic acid
(commercially obtainable under the name "Marlon AS-SaureTM"
from Huls AG) are employed. After 219 g of precipitated
chalk have been added, a creamy-soft, smooth, permanently
homogeneous dimensionally stable composition having a solids
content of 91% and a pH of 6 is obtained and is introduced
into cartridges under air-tight conditions. The dispersion
of organopolysiloxanes prepared in this manner does not
vulcanize to an elastomer even after a maturing or storage
time of 2 months.
. 4 ~ 30
213~4~ ~
,
Example 11
The procedure described in Example 1 is repeated, with the
modification that instead of the 16 g of
[(CH3)3Siol/2]l.l[sio2] silicone resin having an average
molecular weight of 2000 and an average ethoxy content of
2.1% by weight, based on the resin molecule, 16 g of
[(cH2=CH)(cH3)2Siol/2][sio2] having an average molecular
weight of 1300 and an average ethoxy content of 9.9% by
weight, based on the resin molecule, are employed. After 219
g of precipitated chalk have been added, a creamy-soft,
smooth, permanently homogeneous dimensionally stable composi-
tion having a solids content of 91% and a pH of 10.5 is
obtained and is introduced into cartridges under air-tight
conditions. The properties of this dispersion stored in this
way are unchanged over a period of more than 1 year. Data on
the elastomer properties are to be found in Table 1.
Example 12
The procedure described in Example 1 is repeated, with the
modification that the 16 g of [(CH3)3siOl/2]l.l[sio2] sili-
cone resin having an average molecular weight of 2000 and an
average ethoxy content of 2.1% by weight, based on the resin
molecule, are omitted. After 219 g of precipitated chalk
have been added, a creamy-soft, smooth, permanently homoge-
neous dimensionally stable composition having a solids con-
tent of 91% and a pH of 10.5 is obtained and is introduced
into cartridges under air-tight conditions. The properties
of this dispersion stored in this way are unchanged over a
period of more than 1 year. Data on the elastomer properties
are to be found in Table 1.
~ 21~5191
_ Example 13
The procedure described in Example 1 is repeated, with the
modification that the 17 g of [(CH3)2SiO]o 2[(CH3)SiO2]0 8
silicone resin having an average molecular weight of 3000 and
an average ethoxy content of 2.6% by weight, based on the
resin molecule, are omitted. After 219 g of precipitated
chalk have been added, a creamy-soft, smooth, permanently
homogeneous dimensionally stable composition having a solids
content of 90% and a pH of 10.5 is obtained and is introduced
into cartridges under air-tight conditions. The properties
of this dispersion stored in this way are unchanged over a
period of more than 1 year. Data on the elastomer prcperties
are to be found in Table 1.
Example 14
The procedure described in Example 1 is repeated, with the
modification that instead of the 16 g of
[(CH3)3Siol/2]l.l[sio2] silicone resin having an average
molecular weight of 2000 and an average ethoxy content of
2.1% by weight, based on the resin molecule, and 17 g of
[(cH3)2Sio]o.2[(cH3)sio2]o.8 silicone resin having an average
molecular weight of 3000 and an average ethoxy content of
2.6% by weight, based on the resin molecule, 15 g of
[(CH3)3siOo 5]1 l[(cH3)2sio~o.s[(cH3)siol.s]l.g[sio2] having
an average molecular weight of 2500 and an average ethoxy
content of 2.3% by weight, based on the resin molecule, are
employed. After 219 g of precipitated chalk have been added,
a creamy-soft, smooth, permanently homogeneous dimensionally
stable composition having a solids content of 91% and a pH of
10.5 is obtained and is introduced into cartridges under air-
tight conditions. The properties of this dispersion stored
3~
213S49~
~ in this way are unchanged over a period of more than 1 year.
_
Data on the elastomer properties are to be found in Table 1.
Example 15
The procedure described in Example 1 is repeated, with the
modification that instead of the 50 g of water, only 20 g of
water are employed. After 219 g of precipitated chalk have
been added, a creamy-soft, smooth, permanently homogeneous
dimensionally stable composition having a solids content of
95% and a pH of 10.5 is obtained and is introduced into
lo cartridges under air-tight conditions. The properties of
this dispersion remain unchanged for at least 3 months. Data
on the elastomer properties are to be found in Table 1.
The dispersion filled with chalk and also the nonfilled
emulsion before addition of the chalk can be diluted with
water down to solids contents of 5~ and less. The resulting
dispersions, which are storage-stable for at least 6 months,
can be used for coatings, for example of facades or fabrics.
CA 02136491 1998-08-31
TABLE 1
Expe. ~ -cl Tear Strength F'-na -~ Modulus' Shore A Tear Propagation
(N/mmZ) at break (%) (N/mm2) Hardness Resistance (N/mm)
0.7 1040 0.14 10 5.17
2 0.8 710 0.15 8 4.62
3 1.0 650 0.17 10 4.95
4 1.5 810 0.40 17 7.60
0.8 420 0.37 14 5.36
6 1.1 590 0.42 17 6.32
7 0.8 930 0.21 10 3.98
8 0.8 870 0.19 12 3.75
9 0.9 790 0.26 14 4.70
1.1 620 0.25 15 4.23
I l 1.1 580 0.49 21 6.77
12 0.6 320 0.13 7 3.04
13 0.4 250 0.10 6 2.45
14 1.2 420 0.50 23 4.77
0.9 900 0.23 13 5.56
I Tensile strength at 100% elongation.
-34-
