Note: Descriptions are shown in the official language in which they were submitted.
' ` 0050/44248 2 1 6 8 9 4 7
\
Aqueous copolymer dispersions
The present invention relates to aqueous copolymer dispersions
5 which are obtainable by copolymerization, initiated by free radi-
cals or by the use of ionic radiation, of
A) from 40 to 99% by weight of one or more water-insoluble,
monoethylenically unsaturated monomers,
B) from 1 to 60% by weight of one or more water-soluble, mono-
ethylenically unsaturated monomers and
C) from O to 30, in particular from O to 20, % by weight of one
or more polyethylenically unsaturated monomers
in an aqueous medium in the presence of from 2 to 20~ by weight,
based on the total amount of the monomers, of surfactant com-
pounds as emulsifiers, and have a mean particle size of from 5 to
20 37 nm, determined by light scattering in an aqueous medium.
Polymeric latices having particle diameters of more than 100 nm
are usually obtained by conventional free radical polymerization
in disperse oil-in-water phases. Polymerization in microemulsion
25 gives microdispersions which have particle diameters of less than
80 nm, measured in water. These polymers are also referred to as
microlatices, similarly to normal dispersions.
Ecological aspects make it desirable to reduce the proportion of
30 volatile organic compounds, in particular organic solvents, in
formulations for hair cosmetics, one of the most interesting ap-
plications for the stated polymer dispersions. In practice, this
means that, in addition to the traditional main ingredients alco-
hol, ie. ethanol and isopropanol, propellant and hairsetting com-
35 position (film former), improved hairsprays now also contain wa-
ter and other substances which are not covered by the definition
of volatile organic compounds. Other possibilities for reducing
volatile organic compounds in hairspray formulations are the use
of pump sprays or of compressed-gas aerosols. If the formulation
40 were to contain water, it would be desirable, with regard to en-
vironmental protection and cost, for the polymer resin used as
the film former to be prepared in an aqueous system.
Industrial use of microlatices, for example in the area of hair
45 cosmetics, has been prevented to date essentially by the problems
of the unacceptably low solids content of the application for-
mulations of such microlatices and the very large amount of
0050/44248 2 ~ 6 8 9 ~ ~
surfactant - from about 20 to 50% by weight or even more, based
on the monomers used - which is required for its preparation. A
further disadvantage is the use of polymer dispersions as film
formers in formulations for hair cosmetics is the production of
5 an undesirable grayish-white appearance of the hair during the
drying phase.
EP-B 214 626 describes formulations for hair cosmetics having a
particulate polymer which has a weight average particle diameter
10 of from 10 to 100 nm and a particle size distribution such that
the particles having a diameter of from 5 to 200 nm account for
more than 95% of the weight of the particles. A copolymer of 94%
by weight of styrene and 6% by weight of sodium styrenesulfonate,
which has a mean particle size of 42 nm and was prepared by free
15 radical emulsion polymerization in water in the presence of 20%
by weight, based on the monomers used, of the adduct of 30 mol of
ethylene oxide with nonylphenol as emulsifier, is described as
Example N (cf. Table 1 on page 10); the solids content of this
copolymer dispersion, which arises from the preparation, is about
20 19% by weight.
It is an object of the present invention to provide copolymer
dispersions which no longer have the deficiencies of the prior
art.
We have found that this object is achieved by the finely divided
aqueous copolymer dispersions defined at the outset.
Mean particle sizes of from 8 to 35 nm, in particular from 10 to
30 30 nm, especially from 15 to 25 nm, determined by light scatter-
ing in an aqueous medium, are preferred. Particle sizes deter-
mined by other methods may differ slightly from the values stated
here, but as a rule the differences between the individual meth-
ods of measurement are not more than 10%.
The solids content arising from the preparation is preferably
from 20 to 50, in particular from 21 to 40, % by weight.
The novel aqueous copolymer dispersions are usually prepared by
40 photochemical or thermal reaction of the monomers A to C in an
aqueous medium by the use of ionizing radiation or compounds
which form free radicals. Thermal free radical emulsion polymer-
ization is preferred.
45 A preferred embodiment comprises aqueous polymer disper~ions
which are obtainable by copolymerization of
' 0050/44248 ~ 1 6 8 9 1 7
A) from 60 to 92, in particular from 70 to 87, % by weight of
the monomers A and
B) from 8 to 40, in particular from 13 to 30, % by weight of the
monomers B
or by copolymerization of
A) from 60 to 93.5, in particular from 70 to 90, % by weight of
the monomers A,
B) from 6 to 32, in particular from 6 to 25, % by weight of the
monomers B and
15 C) from 0.5 to 15, in particular from 0.5 to 8, preferably from
1 to 5, % by weight of the monomers C.
Suitable components A are usually monomers which have a solubili-
ty of less than 5% by weight in water at 25 C. Examples of mono-
20 mers A are styrene and styrene derivatives, such as ~-methylsty-
rene, p-methylstyrene, p-chloromethylstyrene, p-butylstyrene,
p-ethyl-styrene and p-chlorostyrene, halogenated compounds, such
as vinyl chloride, vinylidene chloride and vinylidene fluoride,
vinyl esters of straight-chain or branched alkanecarboxylic acids
25 having 2 to 30, in particular 2 to 10, carbon atoms in the mole-
cule, such as vinyl acetate, vinyl propionate, vinyl laurate, vi-
nyl neooctanoate, vinyl neononanate and vinyl neodecanoate, buta-
diene and isoprene, vinyl alkyl ethers where the alkyl group is
of 1 to 30 carbon atoms, such as vinyl octadecyl ether, acryloni-
30 trile, 1-alkenes having 3 to 30 carbon atoms in the molecule,
N-alkyl(meth)acrylamides where the alkyl group is of 4 to 30 car-
bon atoms, such as N-tert-butylacrylamide, N-tert-octylacrylamide
and N-undecylmethacrylamide, alkyl acrylates and alkyl meth-
acrylates having 1 to 30 carbon atoms in the molecule such as
35 methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acry-
late, tert-butyl acrylate, 2-ethylhexyl acrylate, lauryl acry-
late, isobornyl acrylate, stearyl acrylate, behenyl acrylate and
the corresponding methacrylates, and (meth)acrylate derivatives,
such as phenoxyethyl acrylate, tetrahydrofurfuryl (meth)acrylate
40 and perfluorooctyl acrylate. Styrene, vinyl esters of alkanecar-
boxylic acids having 2 to 30 carbon atoms in the molecule, alkyl
(meth)acrylates where the alkyl chain in each case is from 1 to
10 carbon atoms and mixtures thereof.
45 Suitable components B are usually those monoethylenically unsatu-
rated monomers which have a solubility of at least 5% by weight
in water at 25 C. Exemplary monomers B contain a group selected
` 0050/44248 2 1 6 8 3 ~ 7
from the class consisting of ether, alcohol, phenol, amino,
imino, amido, carboxylic acid, carboxylic anhydride, phosphonic
acid, sulfonic acid and sulfate ester groups. The groups may also
be integrated in conjugated form and/or in ring structures. Amino
5 and imino groups can also be converted into the corresponding
quaternary groups by reaction with an alkylating agent, and
acidic groups may be present in the form of their salts with
alkali metals, alkaline earth metals, ammonia or organic amines.
Examples for the monomers B are unsaturated carboxylic acids,
10 such as acrylic acid, methacrylic acid, itaconic acid, crotonic
acid, fumaric acid or maleic acid, maleic or fumaric half-esters,
eg. monomethyl, monoethyl or monobutyl maleate or fumarate, phos-
phonic and sulfonic acid derivatives, such as vinylphosphonic
acid, sodium vinylsulfonate, sodium styrenesulfonate, acrylamido-
15 propanesulfonic acid, potassium sulfatopropylmethacrylate orammonium sulfatoethylmethacrylate, acrylamide derivatives, such
as acrylamide, methacrylamide, N,N-dimethylacrylamide, 3-acryl-
amido-3-methylbutyric acid, N,N-dimethylaminopropylacrylamide,
N-methylol(meth)acrylamide, N,N-dimethyl-N-methacrylamidopropyl-
20 N-(3-sulfopropyl)ammonium betaine or 10-acrylamidoundecanoic
acid, (meth)acrylic esters, such as hydroxyethyl(meth)acrylate,
hydroxypropyl (meth)acrylate, ethoxy- and methoxypolyethylene
glycol methacrylates having 2 to 50 ethylene oxide units in the
molecule, polyethylene glycol monomethacrylate, polypropylene
25 glycol monomethacrylate, monomethacryloyloxyethyl phthalate,
monomethacryloyloxyethyl succinate, butanediol monoacrylate,
dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)-
acrylate, quaternized ammonium (meth)acrylates, eg. N-trimethyl-
or N-triethylammoniumethyl (meth)acrylate, N-vinylpyrrolidone,
30 N-vinylcaprolactam, N-vinylimidazole, N-Cl-C10-alkyl-N'-vinyl-
imidazolium compounds, eg. N-methyl-, N-ethyl- or N-butyl-N'-
vinylimidazolium chloride, bromide or methosulfate, 1-vinyl-2-
methylvinylimidazole, 4- and 2-vinylpyridine or N-vinylformamide.
Acrylic acid, methacrylic acid, crotonic acid, Cl-Cl0-alkyl half-
35 esters of maleic or fumaric acid, hydroxyalkyl (meth)acrylateswhere the alkyl chain in each case is of 1 to 10 carbon atoms,
N-tri-Cl-C4-alkylammonium Cl-Cl0-alkylacrylates or -methacrylates,
N-vinylpyrrolidone, N-vinylimidazole, N-Cl-C10-alkyl-N'-vinyl-
imidazolium compounds, N-vinylcaprolactam or mixtures thereof.
If carboxylic acids, sulfonic acids or phosphonic acids are used
as monomers B, some or the total amount of these monomers can be
converted into the corresponding salts by adding a base. Suitable
bases are, for example, alkali metal bases such as alkali metal
45 hydroxides and carbonates, for example NaOH, KOH, sodium carbon-
ate, potassium carbonate, ammonia and organic amines, pyridines,
amidines and mixtures thereof. In the neutralization with the aid
~ 0050/44248 2 1 6 8 ~ 1 7
of organic amines, alkanolamines selected from the group consist-
ing of the mono-, di- and trialkanolamines having 2 to 5 carbon
atoms in the alkanol radical, such as mono-, di- or triethanol-
amine, mono-, di- or tri(iso)propanolamine or 2-amino-2-methyl-
5 propanol, aminoalkanediols where the alkanediol radical is of 2to 4 carbon atoms, such as 2-amino-2-methyl-1,3-propanediol or
2-amino-2-ethyl-1,3-propanediol, amino alkane polyols, such as
tetrahydroxypropyl-ethylenediamine, alkylamines, such as
di(2-ethylhexyl)amine, triamylamine or dodecylamine, and amino
10 ethers, such as morpholine, are preferably used. The base may be
added before, during or after the polymerization.
If nitrogen-containing, basic, ethylenically unsaturated monomers
B are used, they can be converted into the corresponding salts or
15 quaternary compounds before, during or after polymerization by
adding a part or an equivalent amount of an inorganic or organic
acid or suitable alkylating agent, for example alkyl chlorides,
alkyl bromides, alkyl iodides or dialkyl sulfates.
20 The crosslinking components C used are olefinically polyunsatu-
rated compounds, for example divinylbenzene, divinylethyleneurea,
the diamide of diallyltartaric acid, methylenebisacrylamide,
(meth)acrylates of polyfunctional alcohols, such as ethylene gly-
col, 1,4-butanediol, trimethylolpropane, pentaerythritol, neo-
25 pentylglycol, bisphenol A, glycerol, propanediol, alkylene gly-
cols where the alkylene group is of 3 to 20 carbon atoms, poly-
ethylene glycols or polypropylene glycols, allyl esters of
(meth)acrylic acid, trivinylcyclohexane, triallyltriazinetrione,
allyl ethers of trimethylolpropane, pentaerythritol and sucrose
30 having at least two allyl ether units per molecule, dihydrodi-
cyclopentadienyl (meth)acrylate, N-allylmethacrylamide, the
N,N-diallyldiamide of tartaric acid or diallyl phthalate.
Divinylbenzene, allyl (meth)acrylate, polyacrylates or polymeth-
acrylates of C2-C10-alkylpolyols, eg. 1,4-butanediol diacrylate or
35 methacrylate, or mixtures thereof are particularly preferred.
The polymerization is carried out using, as emulsifiers or emul-
sifier mixtures, surfactant compounds usually used in emulsion
polymerization, in an amount of from 2 to 20, preferably from 3
40 to 18, in particular from 4 to 15, especially from 5 to 13, % by
weight, based on the total amount of monomers used. Commercially
available surfactant compounds are widely described in the liter-
ature, for example in R. Hensch, Ullmann~s Encyclopedia of Indus-
trial Chemistry, 5th edition, 1987, Vol. A9, pages 297-339, in
45 E.W. Flick, Industrial Surfactants, Noyes Publication, Park Ridge
1988, or in M.R. Porter, Handbook of Surfactants, Chapman & Hall,
New York 1991. Particular examples of such emulsifiers are
0050/44248 ~ ~ 6 8 9 ~ 7
anionic compounds, in particular alkali metal, ammonium and amine
salts of relatively long-chain fatty acids, alkali metal salts of
sulfuric esters of fatty alcohols and fatty alcohol ethers, eg.
sodium lauryl ether sulfate having 1 to 15 mol of ethylene oxide,
5 and of alkylphenols, alkali metal salts of dialkyl sulfosucci-
nates and alkali metal salts of sulfonic acids of alkylbenzenes,
of alkylnaphthalenes and of naphthalene. However, cationic com-
pounds may also be used, for example fatty amines, quaternary
ammonium compounds or quaternized pyridines, morpholines or
10 imidazolines.
In many cases, a cosolvent or a cosolvent mixture is also added
to the emulsifiers, in amounts of from 0.5 to 20, in particular
from 1 to 5, ~ by weight. Preferred cosolvents are straight-chain
15 or branched aliphatic or alicyclic Cl-C30-alcohols and mixtures
thereof. Examples are n-butanol, n-hexanol, cyclohexanol,
2-ethylhexanol, isooctanol, n-octanol, n-decanol, n-dodecanol,
stearyl alcohol, oleyl alcohol and cholesterol.
20 Further possible cosolvents are alkanediols where the alkyl radi-
cal is of 4 to 20 carbon atoms, ethylene glycol alkyl ethers hav-
ing 1 to 4 ethylene oxide units in the molecule, N-alkylpyrroli-
dones and N-alkyl- and N,N-dialkylacetamides where the alkyl
chain in each case is of 1 to 8 carbon atoms. Examples of these
25 are ethylene glycol monobutyl ether, diethylene glycol monoethyl
ether, tetraethylene glycol dimethyl ether, N-methylpyrrolidone,
N-hexylpyrrolidone, diethylacetamide and N-octylacetamide.
Inert, water-insoluble substances which are capable of dissolving
30 the monomers but not the polymers may also be present in the
polymerization. They tend to act as precipitating agents for the
polymers. Examples of these substances referred to as pore for-
mers are linear or cyclic, straight-chain or branched hydrocar-
bons, eg. cyclohexane, n-hexane or n-octane, carboxylic esters,
35 eg. methyl acetate, ethyl acetate, isopropyl acetate, isobutyl
acetate or methyl propionate, and ketones, eg. acetone, methyl
ethyl ketone or diethyl ketone, in amounts of from 1 to 250~ by
weight, based on the total amount of monomers. They are generally
removed from the reaction mixture during or after the reaction by
40 distillation or another suitable method.
The novel aqueous copolymer dispersions are advantageously pre-
pared by reacting the monomers A to C in water or in aqueous
medium in the presence of emulsifiers or coemulsifiers by using
45 initiators which thermally or chemically form free radicals or by
using ionizing radiation. The reaction can be carried out by
various processes known per se in emulsion polymerization. All
0050/44248 ~ 1 6 8 ~ ~ 7
components may be initially taken at the beginning of the reac-
tion. However, individual components or all components may also
be metered in partially or completely in the course of the reac-
tion, if necessary during different periods. Metering may be
5 effected separately or jointly and if necessary from stirred
vessels.
The polymerization is usually carried out in a stirred reaction
vessel under an inert gas atmosphere. The temperature of the
10 reaction mixture during the polymerization is generally from 40
to 160 C, preferably from 50 to 120 C. If the reaction is carried
out with photochemically active initiators or ionizing radiation,
the temperature may also be outside this range, for example from
0 to 120 C. The temperature can be controlled in different ways by
15 a program during the reaction. The pressure in the reaction ves-
sel is usually brought to 0.8-5 bar but is preferably atmospheric
pressure.
Usually, the copolymerization is carried out in water. However,
20 up to 80% by weight, based on the aqueous phase, of a lower alco-
hol, such as methanol, ethanol or isopropanol, or of a lower
ketone, such as acetone, may also be added before, during or af-
ter the reaction.
25 The copolymerization is preferably carried out in the presence of
initiators which form free radicals under the polymerization
conditions. Suitable free radical initiators are all conventional
peroxy and azo compounds, such as peroxides, hydroperoxides and
peroxy esters, eg. hydrogen peroxide, sodium peroxodisulfate,
30 potassium peroxodisulfate, ammonium peroxodisulfate, dibenzoyl
peroxide, di-tert-butyl peroxide, tert-butyl hydroperoxide, tert-
butyl perpivalate and tert-butyl peroxy-2-ethylhexanoate, and azo
compounds, for example 2,2'-azobis(2-amidinopropane) dihydro-
chloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydro-
35 chloride, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethyl-
valeronitrile)~ dimethyl 2,2'-azobisisobutyrate, 2,2'-azo-
bis(2-methylbutyronitrile) and 2,2'-azobis(4-methoxy-2,4-di-
methylvaleronitrile). It is of course also possible to use initi-
ator mixtures or the known redox initiators. These initiators are
40 used in conventional amounts, for example from 0.05 to 5% by
weight, based on the monomers to be polymerized.
The copolymerization can also be carried out by exposing the
reaction mixture to ultraviolet light. For this purpose, photo-
45 initiators which form free radicals under these conditi~ns areadded to the mixture. Examples of suitable compounds for this
purpose are a-diketones, eg. benzil or diacetyl, acyloins, eg.
0050,44248 ~ 1 6 8 ~ 4 7
benzoin, acyloin ethers, eg. benzoin methyl ether, benzoin ethyl
ether or benzoin isopropyl ether, thioxanthones, eg. thioxan-
thone, 2,4-diethylthioxanthone, thioxanthone-l-sulfonic acid or
thioxanthone-4-sulfonic acid, benzophenones, eg. benzophenone,
5 4,4'-bis(dimethylamino)benzophenone or 4,4'-bis(diethyl-
amino)-benzophenone, acetophenones, eg. acetophenone, p-dimethy-
laminoacetophenone, a, a ~ -dimethoxyacetoxyacetophenone, 2,2'-
dimethoxy-2-phenylacetophenone, p-methoxyacetophenone or 2-meth-
yl-[4-(methylthio)phenyl]-2-morpholino-1-propane, quinones, eg.
lO anthraquinone or 1,4-naphthoquinone, halogenated compounds, eg.
phenacyl chloride, tribromomethyl phenyl sulfone or tris(tri-
chloromethyl)-s-triazine, and peroxides, eg. di-tert-butyl per-
oxide.
15 These photopolymerization initiators may be used alone or as mix-
tures of two or more thereof and are preferably present in an
amount of from 0.1 to 20, in particular from 0.2 to 10, parts by
weight, based on the sum of the monomers used. Activators, for
example tertiary amines, may also be added to these photoinitia-
20 tors.
The molecular weight of the copolymer is preferably controlled,ie. reduced, by adding to the polymerization mixture organosulfo
compounds as regulators. Examples of suitable regulators are mer-
25 capto compounds, such as dodecyl mercaptan, thioethanol, 2-ethyl-
hexyl thioglycolate, 2-mercapto-1-ethanol and thioglycolic acid.
If regulators are present, the amount used is usually from 0.1 to
5~ by weight, based on the monomers used.
30 The novel aqueous copolymer dispersions can be subjected to fur-
ther process steps after the reaction, in order, for example, to
reduce any contents of undesirable impurities. Such process steps
may be, for example, postpolymerization processes, steam treat-
ments, partial distilling off of the solvent or stripping pro-
35 cesses. Said copolymer dispersions may also be subjected to fur-
ther physical treatment steps, such as filtration, drying and
granulation processes.
Further conventional assistants, for example complexing agents,
40 antifoams, preservatives, corrosion inhibitors, free radical
acceptors or antioxidants, may also be added to the novel aqueous
copolymer dispersions.
0050/44248 2 1 6 8 9 4 7
g
The light transmittance (LT) of a 1 cm thick layer of the novel
copolymer dispersions is usually at least 50% for white light at
a concentration of 0.5% by weight, values greater than 70% gener-
ally being reached.
s
The novel aqueous copolymer dispersions are suitable for the
preparation of water-based finishes, coating materials and adhe-
sives. In these formulations, the copolymers are preferably pre-
pared using less than 2% by weight of a crosslinking monomer C.
10 Owing to the small particle size of the polymers, these formula-
tions are optically transparent. They thus have advantageous per-
formance characteristics compared with systems which are formu-
lated by means of conventional dispersions and, owing to the
larger particle diameters, have a milky or even opaque appear-
15 ance. However, the novel copolymer dispersions can also be addedto such formulations in small amounts as assistants, for example
in order to improve rheological properties or to influence the
behavior with respect to UV light. In these cases, more highly
crosslinked copolymers may also be used.
The novel copolymer dispersions can generally be compounded, pre-
ferably in crosslinked form, together with other materials. Ther-
moplastic polymers are particularly preferred. They impart to
these materials improved mechanical properties or a particular
25 scattering power for UV light, as required in many applications,
for example in films for food packaging or in fluorescent light
converters. The novel copolymer dispersions can also be used as
seed latices for core-shell polymers.
30 The novel copolymer dispersions are particularly preferably used
in cosmetic formulations. They are very suitable, in uncross-
linked or only slightly crosslinked form, preferably as film for-
mers in formulations for hair cosmetics, as well as for water-re-
pellent treatment and for reinforcing the protective effect of
35 sunscreen agents on human skin. Owing to the small particle size
of the polymers, it is possible in many cases to provide trans-
parent formulations in aqueous or predominantly aqueous media.
Use as an evaporation barrier in cosmetic formulations is also
possible.
As hairsetting compositions and hair sprays, the novel copolymer
dispersions can be used either in aerosol formulations together
with propellants, such as dimethyl ether, propane, butane and
mixtures thereof or as a compressed-air or pump spray. During the
45 drying phase, the finely divided dispersions do not result in a
grayish-white appearance of the hair, which has to date prevented
the use of dispersions in hair spray formulations because this
` 0050/44248 2 1 6 ~ ~ ~ 7
'-- 10
would not be accepted by the consumer. The films formed on the
hair are clear and nontacky, exhibit little water absorption, can
be readily washed out and have a good setting effect. The compat-
ibility with the propellant is also good.
The advantage of these dispersions over traditional alcoholic or
aqueous alcoholic solutions is the lower viscosity at high active
ingredient concentration. This makes it possible in particular to
reduce the volatile organic compounds, based on the amount of
10 polymer used. If conventional polymers are incorporated as alco-
holic or aqueous alcoholic solutions into the hair spray formula-
tions, the viscosity limits the active ingredient concentration.
Highly viscous solutions cannot be sprayed in sufficiently finely
divided form, so that the polymer concentration in hair spray
15 formulations usually does not exceed 10% by weight.
The present invention also relates to the use of aqueous polymer
dispersions which are obtainable by polymerization, initiated by
free radicals or by the use of ionizing radiation, in an aqueous
20 medium and which have a mean particle size of from 5 to 100 nm,
determined by light scattering in an aqueous medium, as film for-
mers in formulations for hair cosmetics, wherein these cosmetic
formulations have a solids content of these polymers of from 11
to 30, in particular from 15 to 25, % by weight.
Preferred aqueous polymer dispersions are those which are obtain-
able by polymerizing
A) from 40 to 100, in particular from 40 to 99, % by weight of
one or more water-insoluble, monoethylenically unsaturated
monomers A,
B) from 0 to 60, in particular from 1 to 60, % by weight of one
or more water-soluble, monoethylenically unsaturated monomers
B and
C) from 0 to 30, in particular from 0 to 20, % by weight of one
or more polyethylenically unsaturated monomers C.
40 The novel copolymer dispersions may also be used in compositions
for protection from ultraviolet light (UV light), as is also
present in sunlight, particularly preferably for cosmetic ap-
plications, ie. for protecting human skin, and in crosslinked
form. They are capable of effectively scattering UV light pro-
45 vided that their refractive index differs from that of the sur-
rounding medium. They can therefore be used directly as UV screen
agents in cosmetic and in noncosmetic applications, for example
0050/44248 2 1 C 8 9 4 7
-- 11
also for wood preservation or in compounded form for films for
packaging photosensitive foods. They may be used in combination
with one or more W-absorbing components. These mixtures often
have a higher extinction effect than that obtained from the addi-
5 tion of the components on which these mixtures are based. Sun-
screen agents can thus be formulated with a smaller amount of UV-
active components without impairment of their activity. Preferred
weight ratios of copolymers and UV-active components are from
1:99 to 99:1, very particularly preferably from 10:90 to 90:10.
Suitable UV-active components have an absorption maximum in the
wavelength range from 200 to 350 nm with an extinction E of
> 100, measured in 1% strength by weight solution with a path
length of 1 cm. Suitable substances are, for example,
15 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzo-
phenone-5-sulfonic acid, 2,2'-dihydroxy-4-methoxybenzophenone,
p-methoxycinnamic acid, ethyl 4-bis(2-hydroxypropyl)amino-
benzoate, 1-glyceryl 4-aminobenzoate, homomenthyl salicylate,
menthyl o-aminobenzoate, 2-ethylhexyl 2-cyano-3,3-diphenylacry-
20 late, 2-ethylhexyl p-dimethylaminobenzoate, 2-ethylhexyl
p-methoxycinnamate, 2-ethylhexyl salicylate, 4-aminobenzoic acid,
2-phenylbenzimidazole-5-sulfonic acid, triethanolamine sali-
cylate, 3-(4'-methylbenzylidene)bornan-2-one, 2,4-dihydroxybenzo-
phenone, 2,2',4,4'-tetrahydroxybenzophenone, 2,2'-di-
25 hydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-(2-ethyl-
hexyloxy)benzophenone, 1-(4'-isopropylphenyl)-3-phenylpro-
pane-1,3-dione, 1-(4'-butylphenyl)-3-(4-methoxyphenyl)pro-
pane-1,3-dione, ethyl 2-cyano-3,3'-diphenylacrylate, octyltri-
azone, polyethylene glycol p-aminobenzoate, titanium dioxide or
30 zinc oxide.
The present invention thus relates to the use of aqueous polymer
dispersions which are obtainable by polymerization, initiated by
free radicals or by the use of ionizing radiation, of
A) from 40 to 100, in particular from 40 to 99, % by weight of
one or more water-insoluble, monoethylenically unsaturated
monomers A,
40 B) from 0 to 60, in particular from 1 to 60, % by weight of one
or more water-soluble, monoethylenically unsaturated monomers
B and
C) from 0 to 30, in particular from 0 to 20, % by weight of one
or more polyethylenically unsaturated monomers C
` 0050/44248 2 1 6 8 9 ~ 7
12
in an aqueous medium and have a mean particle size of from 5 to
100 nm, determined by light scattering in an aqueous medium, as
compositions for protection from ultraviolet light.
5 In particular, relatively highly crosslinked polymers in the nov-
el copolymer dispersions are those which were prepared in the
presence of pore formers can be used as substrates for ingre-
dients in pharmaceutical or cosmetic formulations or in agro-
chemical formulations, ie. formulations to be used in agricul-
10 ture, for example for oils, vitamins, glycerol, UV absorbers,fragrance materials, preservatives, insecticides, herbicides,
fungicides, messenger substances or insect repellants. These sub-
strates permit, for example, easier incorporation of the compo-
nents, a more pleasant feeling of the formulation on the skin,
15 safer handling or controlled release of the ingredients. The in-
gredients are present in concentrations of from 1 to 200, prefer-
ably from 5 to 80, % by weight, based on the polymer.
The present invention furthermore relates to the corresponding
20 cosmetic formulations themselves, ie. on the one hand aqueous
formulations for hair cosmetics which contain from 1 to 30 % by
weight of solid substance or, in the case of polymer dispersions
having a mean particle size of from 5 to 100 nm, from 11 to 30%
by weight of solid substance of the aqueous copolymer or polymer
25 dispersions, and on the other hand aqueous formulations for hair
cosmetics which contain from 0.1 to 40% by weight of solid sub-
stance of the aqueous copolymer or polymer dispersions.
The present invention also relates to mixtures of from 1 to 99,
30 preferably from 10 to 90, % by weight of the novel finely divided
aqueous copolymer dispersion and from 99 to 1, preferably from 90
to 10, % by weight of aqueous polymer dispersions having mean
particle diameters of from 40 to 10,000 nm, in particular from
100 to 1000 nm, determined by light scattering in an aqueous
35 medium, or from 99 to 1, preferably from 90 to 10, % by weight of
aqueous polymer solutions. Particularly suitable water-soluble
polymers are commercial polymers, such as polyvinylpyrrolidones,
copolymers of vinylpyrrolidone and vinyl acetate, copolymers of
vinyl acetate and crotonic acid, copolymers of vinyl acetate,
40 vinyl propionate and crotonic acid or acrylate/acrylamide-based
copolymers. As discussed above, such mixtures have advantageous
performance characteristics.
The great advantage of the novel copolymer dispersions over
45 traditional alcoholic or aqueous alcoholic solutions is the lower
viscosity at high active ingredient concentration. This makes it
possible in particular to reduce the volatile organic compounds,
0050/44248 2 1 6 8 ~ 4 7
based on the amount of polymer used. The novel copolymer disper-
sions usually have viscosities of from 2 to 50, in particular
from 3 to 30, mPa.s at solids contents of from 20 to 50% by
weight, compared with the values of from about 1000 to about
5 10,000 mPa.s in the case of similar solutions of such copolymers
having comparable solids contents.
The novel copolymer dispersions have the desired high solids con-
tent and a lower emulsifier concentration and at the same time
10 give excellent application results, particularly in formulations
for hair cosmetics, which is due to the particular particle size
spectrum.
The novel copolymer dispersions can be partially or completely
15 neutralized by adding a base. Suitable bases are alkalis, in par-
ticular NaOH, ammonia, amines and/or hydroxyamines, in particular
2-amino-2-methylpropanol.
Preparation examples
Example 1
In a stirred apparatus, 900 g of demineralized water, 172 g of a
27% strength by weight aqueous solution of a sodium lauryl ether
25 sulfate, prepared with two mol of ethylene oxide, and 8 g of
n-butanol were heated to 70-80 C, and 2 g of 2,2'-azobis(2-
amidinopropane) dihydrochloride were added while stirring and un-
der a gentle stream of nitrogen. A feed comprising 383.3 g of
demineralized water, 44 g of the sodium lauryl ether sulfate
30 solution, 2 g of n-butanol, 45 g of methacrylic acid and 255 g of
tert-butyl acrylate was added dropwise to this solution in the
course of 75 minutes at an internal temperature of 77 C. There-
after, 10 g of 2-amino-2-methyl-1-propanol were added dropwise in
the course of 5 minutes at 77 C. The batch was then filtered
35 through a suction filter. The transparent dispersion had a solids
content (SC) of 20.2% by weight; the K value (1% by weight in
ethanol) was 44.7, the LT value (white light, 0.1% by weight) was
98.0% and the mean particle size was 17.5 nm.
40 Example 2
In a stirred apparatus, 350 ml of demineralized water, 74.0 g of
the sodium lauryl ether sulfate solution from Example 1, 2 g of
n-butanol and 0.9 g of sodium peroxodisulfate were heated to 80 C
45 while stirring and under a gentle stream of nitrogen. A feed com-
prising 150 ml of demineralized water, 13.5 g of the sodium
lauryl ether sulfate solution, 2.0 g of n-butanol, 190 g of
0050/44248 2 1 6 8 9 4 7
14
methyl methacrylate, 5.0 g of methacrylic acid, 10.0 g of allyl
methacrylate and 1.3 g of ethylhexyl thioglycolate was added
dropwise to this solution in the course of 2 1/2 hours and at the
same time a second feed comprising 21.5 g of methacrylic acid was
5 added dropwise in the course of 1 1/2 hours. The mixture then
polymerized for a further 3 hours and was then filtered through a
linen cloth. A transparent dispersion having an SC of 30.6% by
weight formed; the LT value (0.01% by weight) was 99%, the LT
value (0.5% by weight) was 75% and the mean particle size was
10 36.7 nm.
Example 3
In a stirred apparatus, 360 ml of demineralized water, 60 g of a
15 28% strength by weight aqueous solution of a sodium lauryl ether
sulfate having 2 ethylene oxide units in the molecule, 2.0 g of
n-butanol and 1.0 g of sodium peroxodisulfate were heated to 80 C
while stirring and under a gentle stream of nitrogen. A feed com-
prising 150 ml of water, 8 g of the sodium lauryl ether sulfate
20 solution, 2.0 g of n-butanol, 126 g of styrene, 18 g of acrylic
acid and 6 g of divinylbenzene was added dropwise to this solu-
tion in the course of 3 hours. The experiment was kept at this
temperature for a further 3 hours. The mixture was then filtered
through a linen cloth. A transparent dispersion having a solids
25 content of 23.2% by weight formed; the LT value (0.5% by weight)
was 89% and the mean particle size was 20.5 nm.
Example 4
30 In a stirred apparatus, 250 ml of demineralized water, 74 g of a
27% strength by weight aqueous solution of a sodium lauryl ether
sulfate having 2 ethylene oxide units in the molecule, 2.0 g of
n-butanol and 0.6 g of sodium peroxodisulfate were heated to 83 C
while stirring and under a gentle stream of nitrogen. A feed com-
35 prising 150 ml of demineralized water, 18.5 g of the sodiumlauryl ether sulfate solution, 2.0 g of n-butanol, 50 g of tert-
butyl acrylate, 25 g of methacrylic acid and 50 g of methyl
methacrylate was added dropwise to this solution in the course of
75 minutes. The experiment was kept at this temperature for a
40 further 2 hours. The mixture was finally filtered through a linen
cloth. A bluish shimmering, transparent liquid having an SC of
21% by weight formed; the LT value (0.5% by weight) was 96.5%,
the K value (1% by weight, ethanol) was 62.7 and the mean par-
ticle size was 16.3 nm.
` 0050/44248 2 1 6 ~ ~ ~ 7
Example 5
In a stirred apparatus, 900 g of demineralized water, 172 g of a
27% strength by weight aqueous solution of a sodium lauryl ether
5 sulfate having 2 ethylene oxide units in the molecule, 8 g of
n-butanol and 2.5 g of 2,2'-azobis(2-amidinopropane) dihydrochlo-
ride were heated to 80 C while stirring and under a gentle stream
of nitrogen. A feed comprising 383 g of demin-
eralized water, 44 g of the sodium lauryl ether sulfate solution,
10 2.0 g of n-butanol, 240 g of tert-butyl acrylate and 60 g of
methacrylic acid was added dropwise to this solution in the
course of 60 minutes. After 25 minutes at this temperature, 10 g
of 2-amino-2-methyl-1-propanol were added dropwise within 10 min-
utes. The mixture was finally filtered through a linen cloth. A
15 bluish sh; -ring, transparent liquid having an SC of 20.4% by
weight formed; the LT value (0.5% by weight) was 96.5%, the K
value (1% by weight, ethanol) was 36.5 and the mean particle size
was 15.0 nm.
20 Example 6
In a stirred apparatus, 700 g of demineralized water, 140 g of a
27% strength by weight aqueous solution of a sodium lauryl ether
sulfate having 2 ethylene oxide units in the molecule, 4.0 g of
25 n-butanol and a solution of 0.9 g of ammonium peroxodisulfate in
8 g of demineralized water were heated to 80 C while stirring and
under a gentle stream of nitrogen. A feed comprising 300 ml of
demineralized water, 37 g of the sodium lauryl ether sulfate
solution, 4.0 g of n-butanol, 5 g of methacrylic acid and 200 g
30 of methyl methacrylate was added dropwise to this solution in the
course of 3 hours. A further feed comprising 45 g of methacrylic
acid was simultaneously added dropwise to this feed in the course
of 2.75 hours. The experiment was kept at this temperature for a
further 0.5 hour. The mixture was finally filtered through a
35 linen cloth. A bluish shimmering, transparent liquid having an SC
of 20.5% by weight formed; the LT value (0.5% by weight) was 96%
and the mean particle size was 17.1 nm.
Example 7
In a stirred apparatus, 340 ml of demineralized water, 90 g of
the sodium lauryl ether sulfate solution from Example 1, 2 g of
n-butanol and 1 g of sodium peroxodisulfate were heated to 80 C
while stirring and under a gentle stream of nitrogen. A feed com-
45 prising 150 ml of demineralized water, 15 g of the sodium laurylether sulfate solution, 2.0 g of n-butanol, 140 g of styrene,
10 g of methacrylic acid, 6 g of divinylbenzene and 234 g of
0050/44248 2 1 6 ~ 3 ~ 7
16
cyclohexane was added dropwise to this solution in the course of
3 hours. The mixture then polymerized for a further 3 hours. The
cyclohexane was then separated off by distillation. After cool-
ing, the mixture was filtered through a linen cloth. A trans-
5 parent dispersion having an SC of 26.5% by weight formed; the LTvalue (0.5% by weight) was 73% and the mean particle size was
34.5 nm.
Example 8
In a stirred apparatus, 350 ml of demineralized water, 33.6 g of
a 28% strength by weight aqueous solution of a sodium lauryl
ether sulfate having 2 ethylene oxide units in the molecule,
2.0 g of n-butanol and 1.0 g of sodium peroxodisulfate were
15 heated to 80 C while stirring and under a gentle stream of nitro-
gen. A feed comprising 150 ml of water, 3.9 g of the sodium
lauryl ether sulfate solution, 2.0 g of n-butanol, 90 g of
styrene, 36 g of ethyl acrylate, 18 g of methacrylic acid and 6 g
of divinylbenzene was added dropwise to this solution in the
20 course of 3 hours. The experiment was kept at this temperature
for a further 3 hours. The mixture was then filtered through a
linen cloth. A transparent dispersion having an SC of 21.2% by
weight formed; the LT value (0.5% by weight) was 88% and the mean
particle size was 23.4 nm.
Example 9
In a stirred apparatus, 350 ml of demineralized water, 54 g of a
15% strength by weight aqueous solution of sodium dodecylbenzene-
30 sulfonate, 2.0 g of n-butanol and 1.0 g of sodium peroxodisulfate
were heated to 80 C while stirring and under a gentle stream of
nitrogen. A feed comprising 150 ml of water, 6 g of the sodium
dodecylbenzenesulfonate solution, 2.0 g of n-butanol, 126 g of
styrene, 18 g of methacrylic acid and 6 g of divinylbenzene was
35 added dropwise to this solution in the course of 3 hours. The
experiment was kept at this temperature for a further 3 hours.
The mixture was then filtered through a linen cloth. A trans-
parent dispersion having an SC of 22.8% by weight formed; the LT
value (0.5% by weight) was 83% and the mean particle size was
40 26.4 nm.
Example 10
In a stirred apparatus, 350 ml of demineralized water, 33.6 g of
45 a 27% strength by weight aqueous solution of a sodium lauryl
ether sulfate having 2 ethylene oxide units in the molecule,
2.0 g of n-butanol and 1 g of sodium peroxodisulfate were heated
` ooso/44248 2 1 6 8 ~ 1 7
- 17
to 80 C while stirring and under a gentle stream of nitrogen. A
feed comprising 150 ml of demineralized water, 3.9 g of the
sodium lauryl ether sulfate solution, 2.0 g of n-butanol, 102 g
of tert-butyl acrylate, 30 g of methacrylic acid, 15 g of ethyl
5 acrylate and 3 g of 1,4-butanediol diacrylate was added dropwise
to this solution in the course of 75 minutes. The experiment was
kept at this temperature for a further 2 hours. The mixture was
finally filtered through a linen cloth. A bluish shimmering,
transparent liquid having an SC of 22.5% by weight formed; the LT
10 value (0.5% by weight) was 90% and the mean particle size was
23.2 nm.
Examples 11 to 15
15 Examples 11 to 15 were carried out similarly to Example 10. The
compositions and the relevant properties of these dispersions
and, for greater clarity, once again the compositions and the
relevant properties of the preceding examples are summarized in
the table below.
Table
Composition and properties of the copolymer dispersions prepared
Ex. Monomers A Monomers B Monomers C Emulsifier Coemulsifier solids Mean Light trans-
No. [% by weight] [% by weight~ [% by weight] [% by [% by content particle mittance [%]
weight, weight, [% by size at 0.5% by
based on based on weight] [nm] weight
monomers] monomers]
1 tBA [85] MAS [15] - 19.4 3.3 20.2 17.5 98*
2 MMA [83.9] MAS [11.7] MASAE [4.4] 10.4 1.8 30.6 36.7 75
3 St [84] AS [12] DVB [4] 12.7 2.7 23.2 20.5 89
4 tBA+MMA [80] MAS [20] - 19.9 3.2 21.0 16.3 96.5
tBA [80] MAS [20] - 19.4 3.3 20.4 15.0 96.5
6 MMA [80] MAS [20] - 19.1 3.2 20.5 17.1 96
7 St [89.7] MAS [6.4] DVM [3.9] 18.2 2.6 26.5 34.5 73
8 St+EA [84] MAS [12] DVB [4] 7.0 2.7 21.2 23.4 88
9 St [84] MAS [12] DVB [4] 6.0 2.7 22.8 26.4 83
tBA [68] + MAS [20] BDA [2] 6.75 2.7 22.5 23.4 90
EA [10]
11 tBA[70]+BA[10] MAS [20] - 6.75 2.7 22.8 23.8 90 2
12 tBA[70]+EA[10] MAS [20] - 6.75 2.7 24.0 17.2 93
0050/44248 2 1 6 8 9 4 7
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- 20
Use examples
Example 16
An aerosol hair spray formulation having a strong setting effect
was prepared using the copolymer dispersion from Example 5 (70 g
of the dispersion brought to pH 7.5 with 2-amino-2-methylpropa-
nol, with the addition of 30 g of dimethoxyethane). This mixture
10 could be readily sprayed (low viscosity), formed a clear film andshowed no white effect, ie. was not visible on dark hair.
Example 17
15 A pump hair spray formulation having a strong setting effect was
prepared using the copolymer dispersion from Example 5 (100 g of
the dispersion brought to pH 7.5 with 2-amino-2-methylpropanol).
The sample could be sprayed directly as a formulation of about
20% strength by weight (fine spray jet) and showed no white ef-
20 fect.
Example 18
An aerosol hair spray formulation was prepared using the copo-
25 lymer dispersion from Example 4 t25 g of the dispersion brought
to pH 6.5 with 2-amino-2-methylpropanol, with the addition of
25 g of ethanol, 20 g of water and 30 g of dimethyl ether). This
mixture had an excellent setting effect, could be readily sprayed
and showed no white effect.
Examples 19 to 24
Pump hair spray formulations having a strong setting effect were
prepared similarly to Example 17, using the dispersions from
35 Examples 10 to 15. All samples could be sprayed directly as for-
mulations of from about 22 to 24% strength by weight (fine spray
jet) and showed no white effect.
