Charge Imbalanced Polyelectrolyte Composition

1. Field of the Invention

This invention relates to polymers useful in cosmetic, pharmaceutical and agricultural formulations, and more particularly, to charge imbalanced polyelectrolyte compositions useful in such applications.

2. Description of the Prior Art

Cosmetic formulations using maleic anhydride interpolymers and/or amphoteric polymers are described in U.S. Pat. Nos. 3,974,128; 3,684,776; and 4,985,487. However, it is desired to provide new and improved polymer compositions which can find particular application in shampoo and hair fixative and conditioner products.

A charge imbalanced composition comprising:

(a) about 10 to 90 mole % of an amphoteric copolymer having the formula ##STR5## where R=alkyl C.sub.1 -C.sub.4,

n=1-6,

R.sub.1 and R.sub.2 are independently alkyl C.sub.1 -C.sub.6, and

R.sub.3 is H,

(b) about 10 to 90 mole % of a polymeric diacid having the formula: ##STR6## where R is as defined above, and

(c) less than about 8 mole % of by-product salts which are the dialkylaminoalkylamine salts of (a) and (b).

The composition described above is made by:

reacting 1 mole of an anhydride compound having the formula ##STR7## where R is as defined above, with less than 1 mole of a compound having the formula ##STR8## where n, R.sub.1 and R.sub.2 are as defined above, and R.sub.3 is H, (b) isolating the product, and

(c) hydrolyzing residual anhydride compound in water to the corresponding diacid compound.

The compositions of the invention are particularly useful as water-soluble adhesives and dispersing agents, and, in particular, in application in cosmetic preparations such as shampoo and hair conditioner products.

The starting copolymers in accordance with the invention are made by copolymerizing an alkyl vinyl ether, e.g. a C.sub.1 -C.sub.6 alkyl vinyl ether, such as a methyl, ethyl, butyl, etc. vinyl ether; and maleic anhydride, to produce copolymers of varying molecular weights. These copolymers are available commercially from ISP under the tradename of Gantrez.RTM. AN, e.g. AN-169, 149, 139 and 119.

These copolymers then are half-amidated with less than a stoichometric amount of an N,N-dialkylaminoalkylamine, such as N,N-dimethylaminoethylamine or N,N-dimethylaminopropylamine.

A 2-liter, four-necked round bottom flask equipped with thermometer, condenser, dropping funnel and a mechanical stirrer was charged with Gantrez.RTM. AN-119* which is a maleic anhydride-methyl vinyl ether copolymer (78.08 g., 0.5 mole repeating unit), acetone (150 ml) and ethyl acetate (500 ml) and heated to reflux. Then N,N-dimethylaminoethyl amine (30.65 g., 0.3 mole) was slowly added during 30 minutes. The solution was stirred while refluxing at 57.degree. C. for 1 hour. The precipitate was filtered, washed with acetone and dried in a vacuum oven at 60.degree. C. for 7 hours. The yield was 95%.

A 2-liter, round bottom, 4-neck flask equipped with an overhead stirrer, condenser, thermocouple (with controller), and dropping funnel/nitrogen inlet system was charged with the following:

Gantrez.RTM. AN-119=312 g. (2 moles)

Heptane=1500 ml.

The mixture was stirred and heated to 50.degree. C.; then 61.2 g. (0.6 moles) of dimethylaminopropylamine was added by dropping funnel over a period of 20 minutes. The reaction was then maintained at 50.degree. C. for a period of 6 hours. After this time the white slurry was filtered to recover the solid product which was then placed in an unheated vacuum oven to dry under vacuum. This produced the anhydride form of the product.

The dry solid from the reaction above was hydrolyzed with water to convert the residual anhydride to the acid form. This was done by combining 192.0 grams with 800 grams of water in a 2-liter round bottom flask equipped with an overhead stirrer, thermocouple (with controller), condenser and nitrogen inlet. The mixture was stirred and heated to 50.degree. C. and maintained at that temperature for 6 hours. The temperature was then allowed to return to room temperature but the stirring was continued overnight. The resultant whitish slurry was then analyzed for percent solids. Results : 21.11%; expected:19.4%.

A 2-liter, round bottom, 4-neck flask equipped with an overhead stirrer, condenser, thermocouple, (with controller), and dropping funnel/nitrogen inlet system was charged with the following:

Gantrez.RTM. AN-119=312 g. (2 moles)

Methyl t-Butyl Ether=1250 ml

The mixture was stirred and heated to reflux at 55.degree. C. A solution of 81.6 g. (0.8 moles) of dimethylaminopropylamine in 250 ml. of methyl t-butyl ether was then dropped in over a period of 30 minutes.

Finally, the reaction was maintained at reflux for hours and then filtered. The white, solid product was then dried under vacuum overnight to remove solvent.

A reaction was carried out in the same manner as in Example 3 except that the addition of dimethylaminopropylamine was 40.8 g. (0.4 mole).

The reaction was the same as in Example 4 except that 20.4 g. of dimethylaminopropylamine was used to produce the product.

The procedure of Example 3 is followed except that Gantrez.RTM. AN-169, AN-139 and AN-149 are used in place of Gantrez.RTM. AN-119, with similar results.

It is to be understood that the above examples are provided to illustrate specific and preferred embodiments of the invention and that many modifications and alterations can be made in these examples without departing from the scope of the invention.