Thickeners for surfactant-containing compositions

Details Thickeners for surfactant-containing compositions Thickeners for surfactant-containing compositions

1999-08-11

2002-06-04

Pezzuto, Helen L. (Department: 1713)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Processes of preparing a desired or intentional composition...

C524S027000, C524S556000, C524S560000, C524S561000, C526S328500

Reexamination Certificate

active

06399679

ABSTRACT:

The present invention relates to the use of hydrophobically modified polymers of monoethylenically unsaturated carboxylic acids as thickeners in hair cleansers, and to aqueous compositions which comprise these polymers.
Thickeners are used widely to increase the viscosity of aqueous preparations, for example in the field of pharmaceuticals and cosmetics. Examples of frequently used thickeners are fatty acid polyethylene glycol monoesters, fatty acid polyethylene glycol diesters, fatty acid alkanolamides, ethoxylated fatty alcohols, ethoxylated glycerol fatty acid esters, cellulose ethers, sodium alginate, polyacrylic acids and neutral salts.
The use of known thickeners is, however, depending on the preparation to be thickened, associated with disadvantages. For example, the thickening action and the salt stability of the thickener can be unsatisfactory, and their incorporation into the preparation to be thickened can be hindered.
U.S. Pat. No. 3,915,921 (The B.F. Goodrich Company) describes copolymers comprising 95-50% by weight of monoethylenically unsaturated carboxylic acids and 5-50% by weight of an acrylic acid or methacrylic acid ester of a C
10
-C
30
fatty alcohol. Optionally, the polymers can be crosslinked. The copolymers are used as thickeners for toothpastes and printing pastes.
EP 0 268 164 (The B.F. Goodrich Company) describes the use of crosslinked copolymers of monoolefinically unsaturated acids (50-99% by weight) and alkyl esters of monoolefinically unsaturated acids (50-1% by weight) (crosslinked with pentaerythritol triallyl ether), which are known under the CTFA name “Acrylates/C
10-30
-Alkyl Acrylate Crosspolymer”. The latter are used to stabilize O/W emulsions in cosmetic and pharmaceutical preparations such as, for example, skin creams, skin lotions and gels.
In WO 97/21744 (BASF Aktiengesellschaft) copolymers which have to be crosslinked are used.
These polymers are precipitation polymers and are free-flowing powders which are stirred into water and then neutralized. This neutralization step is necessary in order to convert the acidic polymers into the carboxylates, which are ultimately responsible for the viscosity.
It is known that these crosslinked (hyhdrophobically modified) polyacrylic acids in the neutralized state react very sensitively to salt. The viscosity breaks up. For this reason, it is unusual to use these polymers in shampoo formulations as viscosity-imparting agents. Because of the salt concentrations present therein (surfactants, surfactant mixtures, NaCl as impurity in surfactants) it is not possible for viscosity to form. The presence of cationic auxiliaries leads to complex formation and precipitation.
EP 0128 237 (The B.F. Goodrich Company) describes weakly crosslinked copolymers (0.1 to 1.0% by weight) of monoethylenically unsaturated carboxylic acids (95.5 to 98.9% by weight) and esters of these carboxylic acids (1 to 2.5% by weight) for use as thickeners in a printing paste.
U.S. Pat. No. 4,432,881 (Dow Chemical Company) describes copolymers of water-soluble monomers such as, for example, acrylamide, acrylic acid etc., preferably the combinations thereof, and N-alkylacrylamides and acrylic esters. The hydrophilic/hydrophobic fraction ratios are from 98:2 mol % to 99.995:0.005 mol %, preferably from 99:1 mol % to 99.9:0.1 mol %. The molecular weights are between 200,000-5,000,000 g/mol, preferably between 800,000-2,5000,000 g/mol. The resulting polymers are used as dispersible hydrophobic thickeners, used in formulations comprising the described polymers, a nonionic surface-active substance (HLB 2-15) and an inorganic salt for increasing the viscosity of water.
U.S. Pat. No. 4,395,524 (Rohm and Haas Company) describes the copolymerization of hydrophilic components (e.g. acrylamide, acrylic acid, N-vinylpyrrolidone etc.) with N-alkylacrylamides (alkyl=C
10
to C
36
, preferably C
12
to C
22
). The copolymerization is carried out as precipitation polymerization or polymerization in solution. The molecular weight of the polymers described is M
w
>30,000 g/mol. The resulting polymers are used as thickeners of aqueous systems, sedimentation stabilizers, surface-active substances or disperrants.
WO 98/31334 describes hair conditioners which do not comprise salts, are not clear and comprise water-insoluble components such as silicone oil and fatty alcohols as active component.
It is an object of the present invention to provide a thickener which can be stirred into a formulation without problem. The formulation preferably comprises at least one alkyl or alkenyl polyglycoside. Such formulations are used inter alia in the cosmetics industry, in particular in hair cleansers, in particular in shampoos. The resulting formulation should be clear and stable and thicken as a result of the addition of the polymers according to the invention.
Surprisingly, we have now found that neutralized, hydrophobically modified polymers of monoethylenically unsaturated carboxylic acids are highly suitable as thickeners for surfactant-containing compositions, e.g. in mild shampoo formulations, in particular for compositions which comprise an alkyl or alkenyl polyglycoside. The formulations according to the invention are clear. The abovementioned disadvantages are not observed here.
We have found that this object is achieved by copolymers which comprise at least 50% by weight and at most 99% by weight of monoethylenically unsaturated carboxylic acid. Preference is given to polymers containing at least 58% by weight and at most 99% by weight of monoethylenically unsaturated carboxylic acid, and very particular preference is given to polymers with a content of monoethylenically unsaturated carboxylic acid of from 65% by weight to 99% by weight.
The polymers are prepared by free-radical polymerization of the corresponding monomers, which in each case comprise at least 50% by weight of monoethylenically unsaturated carboxylic acid.
The hydrophobic component used is at least 1, at most 50% by weight of an a) monoethylenically unsaturated carboxylic acid ester with a saturated C
8
- to C
30
-alcohol, preferably a C
8
- to C
18
-alcohol (e.g. octyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, decyl acrylate, lauryl acrylate, myristyl acrylate, cetyl acrylate, stearyl acrylate, behenyl acrylate, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, lauryl methacrylate, myristyl methacrylate, cetyl methacrylate, stearyl methacrylate, behenyl methacrylate, tert-butylcyclohexyl acrylate). In this connection, particular importance is attached to the acrylic or methacrylic esters of fatty alcohols having from 8 to 18 carbon atoms.
As an alternative to the monoethylenically unsaturated carboxylic acid esters, it is possible to also use b) N-alkyl- or N,N-dialkyl-substituted carboxamides, the alkyl radicals independently of one another being aliphatic or cycloaliphatic alkyl radicals having at least 8 carbon atoms (e.g. N-stearylacrylamide, N-stearylmethacrylamide, N-(1-mehtyl)undecyl acrylate, N-(1-mehtyl)undecyl methacrylate, N-dodecylacrylamide, N-dodecylmethacrylamide, N-octylacrylamide, N-octylmethacrylamide, N,N-dioctylacrylamide, N,N-dioctylmethacrylamide, N-cetylacrylamide, N-cetylmethacrylamide, N-dodecylacrylamide, N-dodecylmethacrylamide, N-myristylacrylamide, N-myristylmethacrylamide, N-(2-ethyl)hexylacrylamide, N-(2-ethyl)hexylmethacrylamide
Particular preference is given to C
8
to C
18
-alkyl radicals.
As a further alternative to the monoethylenically unsaturated carboxylic acid esters, it is also possible to use c) vinyl esters of long-chain aliphatic carboxylic acids (C
8
to C
30
carboxylic acids). Preference is given to using vinyl esters of C
8
to C
18
carboxylic acids.
In addition, it is possible to use d) alkyl vinyl ethers, preferably those containing C
8
to C
18
-alkyl radicals.
It is of course also possible to use mixtures of two or more carboxylic acid esters, carboxamides, vinyl esters or alkyl vinyl ethers, provided the sum of the contents of these comonomers does not exceed 50% by weight.
As the hydrop

Affiliated with

Also associated with

Rating

Thickeners for surfactant-containing compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Thickeners for surfactant-containing compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thickeners for surfactant-containing compositions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2974289