Note: Descriptions are shown in the official language in which they were submitted.
HOE 75/F 31?
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Primers for prepaxing and solidifying the substrate for sub-
sequent coatings must meet the following requirements:
The binder has to penetrate the substrate thoroughly to
ensure its good solidification after drying and to reduce its
absorptive power. The primer -thus has to form a good ground
coat for the subsequent paint layers, and it must be resistant
to water, saponification and atmospheric influence. Solvent
containing primers, which hitherto have met these requirements
solely, have various disadvantages. The solvent content is
dangerous for physiological reasons and because of the fire
risk; the tools have to be cleaned with solvents; the molecular
weight of the binder has to be maintained within a determined
; range since, at high molecular weight, the viscosity of the
primers is too high and does not allow a high binder concentra-
~5 tion.
In contrast to solvent containing primers, aqueous plastics
dispersions are most advantageous. They do not contain flammable
or physiologically intolerable solvents, the tools may be clean-
ed with water, and above all, such dispersions, at a high mole-
2~ cular weight of the binder, may contain a large amount of solids
without having to cope with a excessive viscosity. Moreover, re-
sidual amounts of water in a paint coating dry easier and more
rapidly than solvent residues. Furthermore, provided that their
emulsifier/protective colloid systems are compatible, plastics
dispersions rnay be blencled in more variations, so that the scope
of properti~s may be widely varied by such mixtures of different
dispersions~
Despite the obvious advanta~es, aqueous systems have not
made their way as primers in the practice. Although water-soluble
binders penetrate the substrate thoroughly, they are insufficient-
- 2 - ~
10t~8031
ly water-resistant and/or stable to saponification. When the monomers and the
emulsifier/protective colloid system is adequately chosen, pl~stics disper-
sions give coatings being stable to water and saponification; however, their
depth of penetration is insufficient for solidifying and sealing the substrate.
As has been observed by means of copolymerizing optically briBhtening monomers,
the hitherto used dispersions scarcely penetrate ca-~ities and capillaries of
; the substrate because of their large average particle diameter, and they do
not form practically but a film on the surface.
German Patent Specification No. 1,925,353 proposes a two-step
process according to which vinyl ester copolymer dispersions having particle
~; sizes of less than 0.2 ~ are obtained. However, the polymers described are
not sufficiently stable to water and saponification, and the two-step manu-
facturing process is complicated.
, The present invention is based on the discovery of a process
which enables plastics dispersions having an average particle diameter of from
about 0.01 to 0.06 ~ to be obtained which yield thoroughly penetration primers
stable to water and saponification.
According to the inventionJ there is provided a process for the
preparation of finely distributed plastics dispersions particularly suitable
for the solidifying primer coating of substrates to be painted, which compri-
ses metering a monomer mixture containing
(I) from 20 to 80% by weight of styrene and/or methyl methacryl-
ate as hardening component provided that methyl methacrylateJ if present in
admixture with styreneJ does not exceed 15% by weight of said mixture
(II) from 20 to 80% by weight of an acrylic acid ester with
linear or branched alcohols having from 2 to 8 carbon atoms and/or a meth-
acrylic acid ester with linear or branched alcohols having from 4 to 8 carbon
atoms as plastifying componentJ
10~;8031
(III) from 0.1 to 5% by weight of an amide of an ~ unsaturated
carboxylic acid, and
(IV) from 0.1 to 5% by weight of an a,~-unsaturated monocarbox-
ylic acid,
the total of components (III) and (IV) being in the range of from 0.2 to 8.5%
by weight,in the form of the pure monomer mixture or a preliminary emulsion,
simultaneously with an initiator, into an aqueous liquor containing an anionic
emulsifier, said monomers being used in such an amount that the solids con-
tent of the final dispersion does not exceed 45% by weight, polymerizing said
monomers in said aqueous liquor to form said dispersion, and adjusting said
dispersion to a pH of 7 to 10.
The present invention furthermore relates to the plastics dis-
persions obtained according to the above process.
The monomers have to be selected according to the rules known to
those skilled in the art in such a manner that stable dispersions are obtained
and that the film-forming temperatures of the copolymers are in the range
known to be favourable for the coating technique, that is, advantageously from
about -10 to ~25C.
As hardening component, exclusively styrene is used to particular
advantage. When methylmethacrylate is employed in admixture with styrene, its
amount should not exceed 15% by weight, relative to the total amount of said
mixture.
Examples of the plastifying component are ethylacrylate, propyl-
acrylate, isopropylacrylate and the acrylic or methacrylic acid esters of
butyl alcohol and 2-ethylhexyl alcohol.
For a modification of the properties of the copolymer, further
a,~-unsaturated copolymerizable monomers such as acrylonitrile, hydroxyethyl-
methacrylate, hydroxypropyl-methacrylate, vinyl toluene or vinyl xylene may be
, ~
~ ~ -4-
., ~, .
., . ' ' ,, . . , !
10~i80;~1
concomittsntly us~d.
Amides of ~ unsaturated carboxylic acids, especially acrylamide
or methacrylamide, promote the formation of finely distribu~ed dispersions,
when they are added to the batch during the polymerization simultaneously with
the other monomers. Their concomittant use favours the intended fine distri-
bution of the copolymer, so ~hat a preferred embodiment of the invention pro-
vides the concomittant use of from 1.5 to 3.5% by weight, relative to the
total amount of monomers, of acrylamide or methacrylamide as comonomer.
Incorporation of ~,B-unsaturated monocarboxylic acids into the
copolymer increases the stability of the dispersion during its manufacture,
storage and application. Acrylic and methacrylic acid in the above-stated
amounts of from 0.1 to 5% by weight, relative to the total amount of monomers,
are preferred examples.
On the other hand it has to be taken into consideration that the
amides of group IV and the carboxylic acids of group V being hydrophilic mono-
mers increase the hydrophilic nature of the total molecule. In order not to
reduce the water resistance of the primer coats and coatings obtained with the
use of the dispersions of the invention to a too large extent, the total
amount of the cited monomers should be in a range of from 0.2 to 8.5% by
weight. Within these limits, it may be the higher the higher the content of
hydrophobic monomers of groups I to III, that is, it may touch the upper limit
of the cited range of 0.2 to 8.5% by weight when the other monomers are espe-
cially hydrophobic such as styrene, butylacrylate, 2-ethylhexylacrylate or 2-
ethylhexylmethacrylate, and the lower limit when the other monomers are less
hydrophobic such as methylmethacrylate, ethylacrylate, acrylonitrile or the
hydroxy-alkylacrylates.
As hardening monomer of group I, styrene alone is preferably
MOE 75~F 317
10~;8031
used. Methylmethacrylate may be employed in a maximum amount
of 15 ~ by weight, relative to the total amounts of monomers.
When chosing the kind and amount of monomers of group III,
it has to be taken into consideration that they do not deterio-
-~ 5 rate the stability to water and saponification of the resulting
copolymer.
- Examples of suitable monomer combinations are the following
(parts by weight):
Butylacryla.e/styrene/acrylamide and/or methacrylic acid~acyl-
amide and/or methacrylamide (40 to 80/60 to 15/0.1 to 4/0.1 to 41.
2-Ethylhexylacrylate/styrene/acrylamide and/or methacrylic
acid/acrylamide and/or methacrylamide (30 to80/65 to 15/0.1 to
4/0.1 to 4).
', '15
2-Ethylhexylacrylate/methylmethacrylate/acrylamide and/or meth-
',; acrylic acid/acrylamide and/or methac~ylamide (30 to 80~65 to
~5/0.1 to 4~0.1 to 4).
Butylacrylate/methylmethacrylate/acrylamide and/or methacr,ylic
acid/acrylamide and/or methacrylamide (40 to 80/55 to 15/0.1 to
3/0.1,to 3~.
The polymerization must be performed in the presence of
an anionic emulsifier, for example, alkali metal salts of sul-
uric acid semi-esters o alkyl-phenols or alcohols, which may
be oxethylated;or alkyl or aryl sulfonates.
Preferred anionic emulsifiers are alkali metal salts of-
sulfurlc aci~ semi-esters of a nonyl phenol reacted with from 4
;~29 to 5 moles of ethylene oxide; sodium lauryl sulfate, sodium lau-
.
HOE 75/F 317
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ryl ethoxvlate sulfate con-taining from 2 to 5 moles of ethylene
oxide; sodium clodecylbenzene sul~onate and secondary sodium
alkane sulfonates having from 8 to 20 carbon atoms in the
carbon chain.
The amount of a~ionic emulsifier may be from 0.5 to 10 ~
by weight, preferably from 2 to 8 % by wei~ht, relative to the
total monomers. Generally, an increase of the amount of anionic
emulsifier used brings about a decrease of particle size.
In order to increase the stability of the dispersions, non-
ionic emulsifiers, such as ethoxylated alkylphenols or fatty
alcohols, for example, nonylphenols having from 4 to 30 mols
of ethylene oxide may be employed in addition and in admixtuxe
with the anionic emulsifier. When selecting the emulsifiers
and monomers to be used as well as the preparation process, care
has to be taken that dispersions are obtained which do not tend
to formation of aggregates neither after manufacture nor after
dilution with water, since formation of larger aggregates may
decrease the penetrating po~er when the finely distributed
plastics dis~ersions are used for impregnation and primer coating.
Suitable initiators are the usual inorganic per-compounds
such asa~mx~um persulfa~e, potassium persulfate, sodium persulfate,
or organic peroxides such as benzoyl peroxide, organic peresters
such as perisopivalate. Advantageously the initiators also com-
prise a red~cing agent suçh as sodium bisulfite, hydrazine, or
hydroxylamine It is preferable to use, in addition to the ini-
tiators, catalytic quantities of accelerators such as salts of
iron, cobalt, cerium and/or vanadium; preference is given to the -
use of alkali or ammonium peroxidisulfates.
- ~9 The polymerization temperature may be from 10 to 100 C,
~ 7 ~ ~ -
HOE 75/F 317
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preferably ~rom 30 to 90 C.
The solids content of the dispersions is from 20 to 45 %,
after their manufacture.
It is advantageous for the preparation of the dispersions
having an especially fine particle size distribution according
to the invention when the polymerization is carried out at
low solids concentration, since reduction of the solids concen-
tration generally gives finely distributed dispersions. As
Table 1 shows, latices containing coarser particles have less
pentrating power and less solidifying effect than the finely
distributed dispersions. In the case where finely distributed
dispersions contain an amount of coarser particles because of a
broad distribution of particle sizes, this amount of coarser
particles does not contribute to impart a solidifying effect and
a good penetrating power to the dispersion. Therefore, plastics
dispersions having a narrow distribution of particle sizes are
a preferred embodiment of the present invention.
After polymerization, the pH of the finely distributed
dispersions is adjusted to a pH of from 7 to 10, preferably from
7.5 to 9, by means of alkali, ammonia or amines. When dispersions
having a low solids content are obtained, this solids content
may be increased by vacuum distillation without deteriorating
the extrordinary fine distribution of the dispersions.
The polymerization may be carried out as follows:
from 30 - 50 % of the water and from 20 - 50 % of the anionic
emulsiier together with from 10 - 50 ~ of the non-ionic emulsi-
fier are precharged. A preliminary emulsion is prepared from
the monomers, the remaining part o~ water and the rest of emulsi-
fiers, and is metered during 1 to 3 hours into the liquor formed
~ 8 ~
.. .. . -: :- i - .
. :: ~ - . - . . , ~ ~ . ............... . . . . ... .. . .
. . . . . ..
10~;8031 ~
from the ~ater ~nd emulsiier which has been heated to 50 - 90 C.
- The qunatitative ratio of monomers to water is chosen in such
a manner that the resulting dispersion contains from 20 to 45 %
of solids.
The amount of anionic emulsifier has to be in a range of
from 2 to 8 %, relative to the monomers, depending on the solids
content intended.
The reaction batch is then stirred, and, after termination
of the feed, the whole batch is stirred for another 1 - 3 hours
at a temperature of from 70 to 90 C. The initiator is pre-
ferably added as a 1 to 5 per cent aqueous solution during the
addition of the emulsion. Subsequently, the pH is adjusted to
7.5 to 9 by means of ammonia, aliphatic amines or alkali metal
hydroxides.
The addition of the monomer emulsion is not essential for
preparing the plastics dispersions having fine particle sizes:
they may also be obtained by metering the monomer mixture into
a liquor containing lll the water and the emulsifiers. When
plastics dispersions are to be used for primer coatings and im- - ~
pregnation, the solids content of the dispersions has a decisive ~;
influence on the penetrating depth, the soldifying effect and
the reduction of absorptive power of the treated substrates.
Dilute dispersions penetrate deeper into the substrate
pores than concentrated dispersions. When using concentrated
dispersions, only some of the latex particles penetrate into .
the substrate pores, the others forming a film on the substrate
surface. ~ -~
Therefore, o~ application~concehtrated dispersions reduce
:~
_ g _
~._ .. . . ..... .
... ,: . . - . :. : . . . : . .. .. ~.
HOE 75/F 317
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the absorpti~n of the substrate to a very hic~h degre~, while
dilute dispersions have only a poor reducing effect on the ab-
sorption o~ the substrate.
The solidifying effect de~ends both on the nature of the
polymer and on the amount of polymer per unit area of the treat-
ed surface. ~lthough dilute dispersions penetrate deeply into
the substrate, the amount o~ plastics material per unit area
is relatively low. In the case of concentrated dispersions,
that part oftHe polymer which remains on the surface after dry-
ing does not contribute to the solidification of deeper layers.
It is therefore possible to adjust the ratio of penetrating
depth, solidification and sealing of the surface, and to adapt
these parameters to the various substrates encountered in prac-
tice by a corresponding choice of the solids content. Using
the dispersions of the invention, good results are obtained at
solids amounts of from 5 to 25 % by weight, preferably-from 10
to 20 % by weight. An advantage of the dispersions of the in-
vention resides in t~e fact that within a relatively wide con-
centration range an especially favorable ratio of good penetrat-
ing depth and good solidification can be obtained by a high spe-
cific plastics amount in the treated surface, when the latex
particles have a mean particle size of from 0.01 to 0.0~ ~m
(determination of the particle size according to the light
scattering method and electron microscopy).
As is current practice for dispersion paints, auxiliaries
may be added. Examples of such auxiliaries are solvents for
improving film formation and for lowering the film-forming tem-
perature, plasticizers, defoamers, preservatives, surface-active
29 substances for improving wetting, and pigments or soluble dye-
10 -
,~ ,,,, : : ".
HOE 75/~ 317
iO~;8031
stufEs for t nyein~.
The de~ree of penetration may be tes-ted by different methods.
The material to be submitted to such a test may for example be
applied to the chosen substrate, for example, by brushing, pour-
ing or dropping. After drying, the penetrated material may
then be identified by means of its cross section. If dissolved
resins are us~d, they may be colored by soluble dyestuffs. This
method can however lead to spurious results, when the aqueous
phase is colored simultaneously. Since the aqueous phase of
most: dispersions penetrates deeper than the latex particles,
the colored zone oE the cross section may not correspond to
the actual penetration of the particles.
In order to prove the improved penetration of the disper-
sions of the invention copolymer dispersions containing optical
brighteners were prepared by copolymerization with vinyl-sulfo-
nyl-pyrazoline-brighteners at concentration rates of from 0.01
- 0.05 ~ (based on the monomers). The polymers so prepared
contained in their latex particle a random distribution of
brightener molecules as structural units, all over the macro- -
molecule, and so the optical brightener could not be extracted
from the polymer. The polymer is therefore located in the sub- '! "'
strate exactly where the optical brightener shows the charac-
teristic fluorescence under UV radiation. The copolymer disper
sions containing optical brighteners and having fine particle
sizes were applied onto a number of substrates such as wooden
plates, calcareous sandstone, plaster plates, plastering lime,
plastering concrete, filler coating, unglazed clay plates,
gas concrete, brick etc. The dr~ specimens were checked under
29 UV radiation ancl the depth o~ their penetration measured on the
HOE 75LF 317
~06803~
planes of section.
Other methods for deternlining the penetration of the poly-
mer are also known. One suitable method consists, for example,
of burning off a plane section of coated or impregnated sub-
strate with a bunsen burner, the polymer being the distinguished
by a grey discoloration. Sections of acid-resistant substrates
may also be coated with concentrated sulfuric acid in order to
identify the penetration of the polymer. These experiments
showed that the finely distributed plastics dispersions of the
invention, at the same solids content, penetrate to the same
depth and solidify as well as known binders in solvent-contain-
ing systems, and that the penetration depth and degree of soli-
dification was much greater than that of dispersions with com-
parable polymer structure and average particle size diameters
of more than 0.06 ~m.
The superiority of dispersions having particle sizes of
less than 0.06 ~m was proved especially by the fact that at
relatively high solids contents of, for example, from 15 to 20
per cent by weight which allow the application of a large amount
of plastic material per unit area in one single operation, the
finely distributed dispersions still penetrate almost con~pletely
into the substrate, where they contribute to solidification and
improved anchorage for subsequent paint coatings. Dispersions
having larger particle sizes do not penetrate into the substrate
to a substantial extent, but merely form a film on the surface.
A further test allows to study not only the penetration
of the dispersion but also the degree of solidification obtain-
ed from a certain quantity of binder, by reacting the dispersion
~9 with fine-grained, loose material. This method also has the ad-
- 12 -
HOE 75/F 317
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v~nt~ge that the materlal produces a compound of the grained
m~terial in the pene~ration zc~ne after drying. The solidified
core can be easily removed and weighed. Its weight is a re-
ference for measuring the penetrating ability and the solidi~y-
ing e~fect. This test simulates, for example, the solidifica-
tion of surfacejof old, weather-beaten construction parts.
For performing the test, flat recepticles were filled with
quartz powder (average analysis: 50 % ~ 40~m). Where the
material was to be submitted to the test, a hemispherical groove
having a diameter of 2.5 cm was formed by using a stamp. 2 ml
of the dispersion was dropped into this groove, and after having
allowed the Eilling layer to dry at room temperature for four
hours, it was placed in a drying cabinet at SO C for another
15 hours. The results of these tests are shown in Table 1. The ~
tests were carried out on plastics dispersions according to -
the invention having particle sizes from 0.01 to 0.06 ~m, which
were prepared according to the Examples 1 to 6.
Dispersions having particle size D~ 0.08 ~m were tested
::. . .
for comparison, these dispersions being based on various monomer
systems and commercial polymers in organic solvents which are
recommended for penetrative primer coatings.
The results o~ the tests show that the highest core weight
and thus the best penetrating ability combined with a high
degree of solidification is obtained with dispersions according
to the invention and with the polymer solutions in organic sol-
vents (Table 1); the results obtained from aqueous plastics
dispersions having larger average particle diameters /D> 0.1 ~m)
being clearly inferior to those achieved with the finely distri-
29 buted dispersions ac_ording to the invention.
,
:...... :.~ . ... .. :: - . : ............... ... . . : - .
: .: .. : ::: : : ::: : .,. ,: : , . : . : : ::: : .: : .i. -, . : :. . ,
llOE 75/F 317
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~ further recluiremerlt to be met by primer coatings having
a penetrative effect is thelr capabi]ity of ensuring good ad-
hesion to paints subsequently applied onto the coated substrate
and to provide a good anchoraqe betweerl-the paint and the sub-
strate. This requirement must still be met even in the case where
the paint is applicd to primer layers of uneven thickness which
may be due to irregular absorption of the subs-trate after many
application of the primer.
This requirement was tested by applying about 12 % dispersions
having finest grain sizes according to the invention three times,
separated by intermediate drying, on asbestos cement plates as
substrate. After drying in air for three days, the primer coat
was painted with a dispersion paint containing a styrene/butyl
acrylate dispersion as binder and having a ratio of dispersion
to pigment filler mixture of 1:1.6. A reinforcing cloth strip -
of polyethylene terephthalate was imbedded in the fresh paint
and then painted with the same paint after drying of the first
paint coat.
The adhesion between the primer coat and the substrate, and
between the primer coat and the dispersion paint coat was tested
by trying to remove the cloth strip. ~ood adhesion was found
reyardless of whether it was peeled off dry or wetted by storing
under water and re-drying. The same results were obtained from
tests perfc~rmed according to Examples 1 to 6 with soft binder
2S films which had adjus-table monomer ratios, or with hard binder
f1lms of polymers. Without exception, the cloth strips could be
pulled off the dispersion paint coating leaving the lattice-
type fabric structure embossed on the paintlayer;
29 however, no paint was taken off the substrate or the primer coat
- 14 -
~ . . . .
. . .
HOE 75/F 317
1068031
in this operation. The same resul-ts were obtained by cross-cutting
the dried dispersion paint coating and trying to pull the disper-
si.on paint film off the cross-cut squares by means of an adhesive
tape. The paint layer did not come off either.
The following Examples illustrate the preparation of finely
distributed dispersions of the invention.
E X A M P L E 1:
.. .. _ . . :
A stable monomer emulsion is prepared from
styrene 134 parts by weight .
butylacrylate 200 parts by weight
acrylamide .4.5 parts by weiyht
methacrylic acid 12.0 parts by weight
sodium salt of a secondary
alkyl-sulfonate (C12-C16)10 parts by weight ..
reaction product of nonyl-phenol
with 10 ~ 12 moles of ethylene oxide 5.0 parts by weight
water 400 parts by weight
The emulsion is metered i.nto a liquor of 230 parts by weight
of water, 2 parts by weight of a non-ionic emulsifier and 8 parts ~ ~.
by weight of an ionic emulsifier. Simultaneously to the dosage
of the emu~sion, a sol.ution of 2 parts by weight o~ ammonium
persu~ate in 40 parts by weiyht o.E water is added.
The mean particle size of the dispersion adjusted to a pH
of 8 - 9 is 0.036 ~m.
E X A M P I. E 2:
Copolymer dispersions containing an optical brightener and
having fine particles are obtained by dissolving additionally 0.1
part by weight of a vinyl-sulfonyl-pyrazoline brightener (cf.
29 German Offenleyungsschrift No. 2 011 552) in the rnonomer mixture
- 15 ~
.. . . . . :: . : : : , . , . ~ .
~ -, ,,, -,, . , . :
HOE 7~F 317
1068031
of E~am~le 1, and subsec~uently preparing the plastics dispersions
as before.
Both the aqueou~ plastics dispersion and the dry polymer
film exhibit a chara~teristic blue fluorescence under UV radia-
tion which allows detection of even very small polymer amounts
in the different substrates. Fractionating by gel permeation
chromatography shows that the optical brightener is incorporated
uniformly in the polymer, i.e. no accumulations are formed in
certain ranges of molecular weight. The a~Terage particle size
of the copolymer dispersion containing the optical brightener
is 0.038 ~m.
E X A M P L E 3:
A monomer mixture comprising
styrene 170 parts by weight
butylacrylate 170 parts by weight
acrylamide 4 parts by weight
methacrylic acid 10 parts by weight
is metered into a liquor comprising 680 parts by weight of
water, 25 parts by weight of a secondary sodium alkyl sulfonate
(C12-C16) and 10 parts by weight of the reaction product of
nonyl~phenol and from 8 - 12 moles of ethylene oxide.
A solution of 2 parts by weight of ammonium persulfate in
40 parts by weight of water is used as initlator. The average
particle size diameter is 0.038 ~m.
E X A M P L E 4:
~ stable monomer emulsion is prepared from
styrene 3600 parts by weight
~utyl acrylate 3600 parts by weight
- 2g acrylam;`de 100 parts by weight
~ .
- 16 -
.
flOE 75/F 317
10~;80;~
methdcrylic ac.id 250 parts by ~eight
sodium lauryl sulEate 340 parts by weight
reaction product of nonyl~phenol
with 8 - 12 moles of ethylene oxlde180 parts by weight
water 10,000 parts by weight
The emulsion is metered into a liquor of 5000 parts by weight
of water, 80 parts by we;.ght of the non-ionic emulsifier and 280
parts by weight of the anionic emulsifier. A solution of 40 parts ~-
by weight of ammonium persulfate in 900 parts by weight of water
is metered in simultaneously. The average particle diameter of ~ . :
the dispersion adjusted to a pH of 8 - 9 is 0.042 ~m.
The dispersion can be concentrated in the same reaction
vessel, under water jet vacuum, to a solids content of about 45 %.
The average particle size remains 0.042 ~m.
E X A M P L E 5: ;
A monomer mixture of
methylmethacrylate 130 parts by weight
butylacrylate . 200 parts by weight
acrylic acid 12 parts by weight
acrylamide 4 parts by weight
is metered into a liquor of 660 parts by weight of water, 20 parts
by we.ight of sodium lauryl ethoxylate-sulfate (with 2 - 5 moles
of ethylene oxide) and 8 parts by wei.ght of a reaction product
of nonyl-phenol and 6 - 10.moles of ethylene oxide. A solution
of 3 parts by weight of potassium persulfate in 30 parts by weight
of water is used as initiator. The average particle size is 0.04.1
~m.
E X A M P L E 6
2~ Irhe composition of the liquor is as in Example 5.
. - 17 -
: . . . .
- - . . . - :. .. . . .
: . .. , . - , . . . ~ .. ; -:
: ~ . - .. , : ~ .
IIOE` ~ 3 ~ 7
~0~8~31
rhe m~ o~ r r~li xt~re comprises
methylmethacrylat~100 parts by weight
b~Itylacrylate230 parts by w~ight
acrylic ac.i.d13 parts by weight
ac~ylamic1e5 parts by wei.ght
2 parts by weight of potasslum persulfate dissolved in 20 parts
~y weight of water are employed as inltiator. The average par-
ticle diameter is 0.045 ~m.
E X A M P ~. E 7
_ _ ~ _ _
A stable monomer emulsion is prepared from
styrene 170 parts by weight
butylacryla-te 170 parts by weight
sodium lauryl sulfate15 parts by weight
reaction product of nonyl-phenol with
8 - 12 moles of ethylene oxide5 parts by weight
water 450 parts by weight
The emulsion is metered into a liquor consisting of 200
parts by weight of wa-ter, 3 parts by weight of the non-ionic
emulsifier and 8 parts by weiyht of the ioni.c emulsifier~ A
solution of 3 parts by weight of ammonium persulfate in 30 parts
by weight of wat~r is simultaneously metered in.
The average parti.~le size of the dispersi.on being adjusted
to ~I 8 - 9 is 0.060 ~m.
~ TqVE: EX~IPLE A: .
A copolymer dispersion is prepared comp~ising
vinyl acetate 70 parts by weight
Versatic(R)-~OC-acid vinyl ester 25 parts by weight
srotonic acid 5 parts by wei.ght
29 with an anionic emulslfier and an inorganic per-compound and
- 18 -
. .- . ~ . . :i,,,. .. . . ,, , ,; , . . . .
HOE 75/F 317
` 10~;8031
CO~ li.n~ L ta,~ 10 - 50 ~ o solids.
Tlle avera~Je particle size is 0.620 ~m.
COMPAR~ IVE EX MrÆE - :
A copolymer ~ispersion is prepared according to Æxample A~
consisting of
vinyl acetate 70 parts by weight
butylacrylate 30 parts by weight.
The average particle size is 0.270~m.
COMPARATlVÆ EXAMPLE C:
A copolymer dispersion is prepared, comprising
styrene50 parts by weight
butylacrylate
50 parts by weight
acrylic acid2 parts by weight
methacrylic acid
5 parts by weight
acrylamide
3 parts by weight
with a mixture of anionic and non-ionlc emulsifiers and an in-
organic per-compound.
The average particle size is 0.150 ~m.
COMPARATIVE EXAMPLE D:
A copolymer composed of
vinyl acetate 70 parts by weight
maleic acid dibutylester 30 parts by weight
is dissolved in ethyl acetate to yield a 60 % solution. The
viscosity at 20 C acco~ding to H~ppler (DIN 53 015) is 80 P.
a primer having penetrative effect is prepared from this solution
in the following manner:
60 % copolymer solution in ethyl acetate 28 parts by weight
Shellsol A (trade mark) 62 parts by weight
~`~ ethyl~lycol acetate l0 parts by weight
.
HOE 75/F 317
10~803~
?~ r \~" 1~ r,~
Froma copol~mer comprising
vinyl toluene 85 parts by weight
acrylic acid-2-ethy].-he~yl ester15 parts by weight
5 having a viscosity of about 60 cP at 20 C according to Hoppler
in a 30 8 solution in xylene, a primer coating solution is pre-
pared in the Eollowing manner:
copolymer 170 parts by weight
white spirit 545 parts by weight
Shellsol A (trade mark) 285 parts hy weight
'-:
- 20 ~
'
HOE 75~'F 317
10~8~
T ~ B ~, E
_ .,,
Penetration test_in ~artz sand fill.i~s
~x- ~ver~e particle size (~Im) core weiyht (~) after appli-
ample (according to light scatter- cation of 2 ml of a 17 %
.ng ~ethod) and 11 ~ dispersion
1 0.036 l2.3 13.6
2 0.038 11.8 12.5
3 0.038 12.1 12.8
4 0 04~ 10.5 11.9
0.041 11.3 11.9
6 0.045 11.1 11.5
7 0.060 10.5 11.Q
. _ . _ _ . _ __ . _ _ . _ _ . _ _ _ . _ _ _ . _ ~ _ _ . . _ _ _ , _ _ _ _ : _ .
Comparative
Examples
. . _
A 0.620 0.6 1.1 -~
B Ø270 3.4 3.8
C 0.150 6.0 6.4
D - 10.8 11.0
E - 10.4 11 2
21
