U.S. patent number 6,667,029 [Application Number 09/781,505] was granted by the patent office on 2003-12-23 for stable, aqueous cationic hydrogel.
This patent grant is currently assigned to ISP Investments Inc.. Invention is credited to Janusz Jachowicz, Roger L. Mc Mullen, Jr., Philip F. Wolf, Yuanzhen Zhong.
United States Patent |
6,667,029 |
Zhong , et al. |
December 23, 2003 |
Stable, aqueous cationic hydrogel
Abstract
A stable, aqueous cationic hydrogel of, by weight, 1-50% of a
crosslinked cationic copolymer of 5-95% vinylpyrrolidone (VP) and
5-95% 3-dimethylaminopropyl(meth)acrylamide (DMAPMA) monomers, a
crosslinking agent in an amount of 0.05-1% of said monomers, and
water is described. The hydrogel has a pH of about 10 and a
Brookfield viscosity of about 650 (Model DV-II+, RV spindle #3,
speed 10 rpm); it can increase its viscosity by up to 40.times. at
a pH of 3-9 and absorb up to 200.times. its weight of water. The
hydrogel also can effectively condition hair even in the presence
of an anionic surfactant.
Inventors: |
Zhong; Yuanzhen (Wayne, NJ),
Jachowicz; Janusz (Bethel, CT), Wolf; Philip F.
(Bridgewater, NJ), Mc Mullen, Jr.; Roger L. (Bloomfield,
NJ) |
Assignee: |
ISP Investments Inc.
(Wilmington, DE)
|
Family
ID: |
23370505 |
Appl.
No.: |
09/781,505 |
Filed: |
January 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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349011 |
Jul 7, 1999 |
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Current U.S.
Class: |
424/70.22;
424/70.1; 526/264; 424/70.16; 424/70.15; 424/70.11 |
Current CPC
Class: |
C08F
226/10 (20130101); A61K 8/8182 (20130101); A61Q
5/12 (20130101); C08F 220/60 (20130101); A61Q
5/02 (20130101); A61Q 5/06 (20130101); A61K
8/042 (20130101); C08F 226/10 (20130101); C08F
220/60 (20130101); C08F 222/103 (20200201); C08F
226/10 (20130101); C08F 220/60 (20130101); C08F
222/385 (20130101); C08F 226/10 (20130101); C08F
220/60 (20130101); C08F 222/103 (20200201) |
Current International
Class: |
C08F
220/00 (20060101); C08F 220/60 (20060101); C08F
226/10 (20060101); C08F 226/00 (20060101); A61K
007/075 (); A61K 031/79 (); C08F 226/10 () |
Field of
Search: |
;424/70.1,70.11,70.15,70.16 ;526/264 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Qazi; Sabiha
Attorney, Agent or Firm: Katz; Walter Davis; William J.
Maue; Marilyn J.
Parent Case Text
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This is a continuation-in-part of U.S. Pat. Ser. No. 09/349,011,
filed Jul. 7, 1999 now abandoned, by the same inventors and
entitled, "Crosslinked Cationic Microgels, Process for Making Same
and Hair Care Compositions Therewith".
Claims
What is claimed is:
1. A stable, aqueous flowable cationic homogenized hydrogel
consisting essentially of, by weight, 1-50% of a crosslinked
cationic copolymer of 40-70% vinylpyrrolidone (VP) and 30-60%
3-dimethylaminopropyl(meth)acrylamide (DMAPMA) monomers, a
crosslinking agent in an amount of 0.05-1% of said monomers, and
water, said homogenized hydrogel having a pH of about 10, a
Brookfield viscosity of about 650 (RV spindle #3, speed 10 rpm),
and is capable of increasing its viscosity up to 40.times. at a pH
of 3-9, and of absorbing up to 200.times. its weight of water, and
of effectively conditioning hair in the presence of an anionic
surfactant.
2. A cationic hydrogel according to claim 1 in which said
crosslinking agent is present in an amount of 0.1-0.5%.
3. A cationic hydrogel according to claim 2 in which said amount is
0.2%.
4. A cationic hydrogel according to claim 1 wherein said copolymer
comprises 50-65% VP and 35-50% DMAPMA.
5. A cationic homogenized hydrogel according to claim 1 with 5-20%
of said copolymer therein.
6. A cationic homogenized hydrogel according to claim 5 with 1-5%
of said copolymer therein.
7. A composition comprising the homogenized hydrogel of claim 1, at
a pH of 3-9, as a viscosity modifier therein, which can provide a
Brookfield viscosity for said composition of at east 10,000 cps at
1% copolymer solids.
8. A composition according to claim 7 wherein said pH is 4-8.
9. A hair treatment composition comprising about 0.01-5% by weight
of the cationic hydrogel of claim 1, and an anionic surfactant, for
conditioning, styling and cleansing.
10. An aqueous solution polymerization process of making the
flowable cationic homogenized hydrogel of claim 1 which comprises
forming a mixture, by weight, of 1-50% of a blend of 40-70% VP and
30-60% DMAPMA monomers, 0.1-0.5% crosslinker, water and initiator,
polymerizing the mixture with agitation at a temperature of about
60.degree. C. for about 11/2 hours, then at 85.degree. C. to reduce
residual monomers, optionally adding water periodically to reduce
the solids content of the product, and homogenizing the product to
form a flowable cationic homogenized hydrogel.
11. A process according to claim 10 wherein said copolymer contains
about 20% of a mixture of 50-65% VP, 35-50% DMAPMA and about 0.2%
crosslinker.
12. A process according to claim 11 wherein water is added
periodically to reduce the solids content to about 5%.
13. A product of the process of claim 10.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hydrogels, and, more particularly, to
stable, aqueous, crosslinked cationic hydrogels which are effective
viscosity modifiers and swelling agents, and can function as
conditioners in anionic surfactant-containing shampoo
formulations.
2. Description of the Prior Art
Polymeric crosslinked polyacrylic acid thickeners have been used to
modify the physical form, function and aesthetics of personal care
formulations. However, such anionic hydrogels do not maintain their
thickener action at a low pH; also they are not compatible in a
cationic formulation.
Similarly, Aizawa, T. et al, in U.S. Pat. No. 5,338,815, described
the preparation of fine particulate crosslinked N-vinylamide homo-
and co-polymers, particularly poly-N-vinylformamide and
poly-N-vinylacetamide, which had thickening properties; however,
only in neutral water, (pH 6-8).
Other references of interest in this art are U.S. Pat. Nos.
5,321,110; 5,603,926; 5,663,258 and 5,684,105; Y. Zhong and P.
Wolf, Hydrogel Prepared from Crosslinked Vinyl Pyrrolidone and
Vinyl Acetate Copolymer, Polymer Reprints 1997,38 (2), p. 578; and
Y. Zhong and P. Wolf, Swelling Properties of Crosslinked
Vinylpyrrolidone Homopolymers and Vinylpyrrolidone/Vinyl Acetate
Copolymers, Polymer Reprints 1998,39 (2), p. 461.
Accordingly, it is desired to provide a stable, aqueous crosslinked
(XL) cationic hydrogel which is an effective viscosity modifier,
and capable of adsorbing large amounts of water per weight of
polymer, which is advantageous for hair thickening, conditioning
and styling, in formulations having an anionic surfactant, across a
wide pH range including low pHs.
These and other objects and features of the invention will be made
apparent from the following description thereof.
IN THE DRAWINGS
FIG. 1 is a plot of viscosity in cps vs. pH adjusted with HCl for
XL-PVP/DMAPMA cationic copolymer hydrogels of invention at a solids
content of 1%, at various monomer ratios, the crosslinker being
present in an amount of 0.2% by weight of monomers.
FIG. 2 is a plot of viscosity in cps vs. % VP in XL-PVP/DMAPMA
cationic copolymer hydrogel at a solids content of 1%, crosslinker
0.20% by weight of monomers, at various pHs.
FIG. 3 shows curves of differential force combing (G) vs. distance
(nm) along hair tresses for virgin hair treated with a control
shampoo FIG. 3(a), shampoo containing Polymer JR FIG. 3(b), and
shampoo containing the cationic hydrogel of this invention FIG.
3(c).
FIG. 4 presents dry hair tresses after the combing experiment. The
fibers were treated with shampoo containing the cationic hydrogels
of this invention (Sample #1, Tress 1, Sample #2, Tress 2) and
control shampoo without conditioning agents (Tress 3).
SUMMARY OF THE INVENTION
What is described herein is a stable, aqueous cationic hydrogel
comprising, by weight, 1-50% of a crosslinked cationic copolymer
which is a blend of 5-95% vinylpyrrolidone (VP) and 5-95%
3-dimethylaminopropyl(meth) acrylamide (DMAPMA) monomers, a
crosslinking agent in an amount of 0.05-1% of said monomers, and
water, said hydrogel having a pH of about 10 and a Brookfield
viscosity of about 650 (Model DV-II+, RV spindle #3, speed 10 rpm).
The hydrogel can be further characterized by its increased
viscosity up to 40.times. at a pH of 3-9; as well as being capable
of absorbing up to 200.times. its weight of water. A hair treatment
formulation containing this hydrogel can effectively condition hair
even in the presence of an anionic surfactant.
In the preferred forms of the invention, the crosslinking agent is
present in an amount of 0.1-0.5%, most preferably 0.2%; and the
copolymer comprises 50-65% VP and 35-50% DMAPMA.
Preferably, also, the cationic hydrogel contains 5-20% of said
copolymer; and in personal care formulations, 1-5%.
The cationic hydrogel of the invention, at a pH of 3-9, preferably
4-8, is useful as a viscosity modifier or swelling agent.
Personal care formulations of the invention include hair treatment
compositions including about 0.01-5% by weight of the cationic
hydrogel, and an anionic surfactant, for conditioning, styling and
cleansing action.
The cationic hydrogel of the invention is made by an aqueous
solution polymerization process. The process comprises forming a
mixture of, by weight, 1-50% of a blend of 5-95% VP and 5-95%
DMAPMA monomers, 0.1-0.5% crosslinker, water and initiator,
polymerizing the mixture with agitation at a temperature of about
60.degree. C. for about 11/2 hours, then heating at 85.degree. C.
to complete the polymerization, and, if necessary adding water
periodically to reduce the solids content of the product, and,
optionally, homogenizing the resulting hydrogel product.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the XL-PVP/DMAPMA copolymer of the cationic
hydrogel comprises, by weight:
Suitable Preferred Optimum VP 5-95 40-70 50-65 DMAPMA 5-95 30-60
35-50
During the polymerization reaction, the crosslinker level suitably
is about 0.01-5%, preferably about 0.1-2%, and optimally about
0.2%, based on the total weight of monomers.
Suitable crosslinkers include pentaerythritol triallyl ether (PTE)
and methylene-bis-acrylamide (BIS).
During the polymerization reaction, the total initial monomer level
suitably is about 1-50%, preferably about 5-40%, and optimally
about 15-30%.
Suitable initiators for the polymerization reaction include
tertiary butyl peroxy pivalate (Lupersol.RTM. 11) and tertiary amyl
peroxy pivalate (Lupersol.RTM.554).
The invention will now be described in more detail with reference
to the following examples.
EXAMPLES
Monomers: VP: (International Specialty Products). DMAPMA: (Rohm
America). Crosslinkers: Pentaerythritol triallyl ether (PTE),
HOCH.sub.2 --C(--CH.sub.2 --O--CH.sub.2 --CH=CH.sub.2).sub.3 and
methylene-bis-acrylamide (BIS), (Aldrich). Initiators: tertiary
butyl peroxy pivalate (Lupersol.RTM. 11) and tertiary amyl peroxy
pivalate (Lupersol.RTM. 554), (Lucidol). Solvent: Deionized water.
Non-solvent: Heptane, (Aldrich).
EXAMPLE 1
Preparation of XL-PVP/DMAPMA Cationic Hydrogel of Invention
The optimized reaction cycling time is very short (1.5 hours at
60.degree. C. and 4 hours at 85.degree. C.). The process includes
the steps of: (1) Clean, dry, and tare a 1-liter glass resin
reaction flask. (2) Install the reactor with agitator, heating
mantle, condenser, thermocouple, septum for initiator addition, and
nitrogen purging. (3) Add part of water solvent, all VP monomer,
all DMAPMA monomer, all the BIS crosslinker, and all the
Lupersol.RTM. 11 initiator, into the reactor.
The VP/DMAPMA ratio will vary depending on the kind of hydrogel to
be made. A preferred initial concentration of VP and DMAPMA in the
system is 20% by weight. The preferred weight ratio of crosslinker
to VP and DMAPMA is 0.20%. The preferred weight ratio of
Lupersol.RTM. 11 to VP and DMAPMA is 1.10%. (4) At room
temperature, start a purge with nitrogen until the reaction is
complete. (5) Raise the temperature to 60.degree. C. and maintain
for 1.5 hours. (6) During the 60.degree. C. period, when gelation
occurs and the system is too viscous to agitate, add water to
dilute the system from 20% to 10% solids. (7) Raise the temperature
to 85.degree. C. and maintain for 4 hours to reduce the residual
monomer level. (8) When reaching 85.degree. C., directly inject
Lupersol.RTM. 554 hourly through the syringe and rubber septum on
the top of reactor into the reaction mixture. Four (4) additions of
Lupersol.RTM. 554 as booster are sufficient to reduce the residual
monomer to acceptable levels. (9) During the 85.degree. C. heating
period, when the system is too viscous to agitate, all water to
further dilute the system from 10% to 7.5% solids. (10) When the
reaction is complete, cool the system to room temperature, and
transfer the product into a large beaker. (11) A Ross Homogenizer
is used to break up the gel. Addition of water to further dilute
the system to 5% solids is used to enable the product to flow in
and out of the homogenizer.
Brookfield Viscosity Measurements
The viscosity of aqueous copolymer solutions were measured with a
Brookfield Digital Viscometer.
The XL-PVP/DMAPMA copolymer hydrogels of the invention have a low
viscosity at high pH, where the amines are essentially uncharged.
However, upon addition of a suitable acid, the pH drops and
positive charges are generated on the polymer side chains as the
amine monomer is protonated. The repulsion forces developed between
these positive charges causes the polymer to swell, enabling the
cationic hydrogel to be used effectively as a thickener at a low
pH.
Swelling Volume Measurements
A 1% (w/v) aqueous solution was stoppered in a 100 ml graduated
cylinder and allowed to stand at room temperature for 2 days. The
volume attained by the gel was recorded as the swelling volume with
the units of ml/g.
The cationic hydrogel of this invention shows an extremely high
capacity for adsorbed water. For example, 0.01 g of dry
XL-PVP/DMAPMA adsorbs 1.7 grams of deionized water, which is 170
times its weight.
EXAMPLE 2
Conditioning Shampoo Formulation
Part A (% By Weight) 15 Ammonium Lauryl Sulfate (Standapol.RTM. A,
Henkel Corporation) 15 Sodium Lauryl Sulfate (Rhodaon.RTM.
SB-8208/S, Rhone Poulenc) 8 Cocamidopropyl Betaine (Mirtaine.RTM.
CB, Rhone Poulenc) 2 Lauramide DEA (Monamid.RTM. 716, Mona
Industries)
Part B (% By weight) 1 Cationic hydrogel of Invention as
Conditioning Additive 58.8 Deionized H.sub.2 O
Part C (% By Weight) 0.2 Diazolidinyl Urea/lodopropynyl
Butylcarbamate (Germall.RTM. Plus, ISP)
Instructions
Heat Part A to 60.degree. C. with moderately slow stirring for
approximately 1/2 hour or until solution becomes transparent. At
the same time, heat Part B to 55.degree. C. while stirring until
homogeneous solution is obtained. Add Part B to Part A while
continuously stirring. Remove temperature source. Once the
resulting solution has reached 45.degree. C., add Part C. Continue
to stir (slowly) until the target solution has cooled to an ambient
temperature.
The combing curves for control and Polymer JR shampoo in FIGS. 3(a)
and (b) show two maxima at about 40 and 85 nm. In contrast, hair
treated with a shampoo containing the cationic hydrogel of this
invention, FIG. 3(c), shows two minima in the same positions. Thus,
this data demonstrates the conditioning effect of the cationic
hydrogel of this invention when applied from a shampoo base.
As shown in FIG. 4 in the case of hair treated with shampoos
containing the cationic hydrogels of this invention (Tresses 1 and
2), the fibers are glued together in the treated areas, with the
effect particularly strong for Sample #1 polymer (Tress #1). This
demonstrates the styling effect of the cationic hydrogel.
Effective hair care compositions can be made with the crosslinked
cationic hydrogel of the invention. In such formulations, the
crosslinked hydrogel dispersion provides relatively thick and
lubricious layers on the surface of hair. Unlike linear,
uncrosslinked cationic polymers, which lay flat on the hair
surface, the swollen hydrogel particles of the crosslinked
copolymer forms thick deposits which significantly modify the
surface properties of hair.
The invention copolymer also can be used effectively in anionic
surfactant-based shampoo compositions which ordinarily do not
provide a favorable medium for deposition of linear cationic
polymers or surfactants. The XL-PVP/DMAPMA copolymer, in contrast,
when used, for example, as a 1% solution, provides excellent
conditioning as evidenced by wet and dry combing evaluations.
Specifically, shampoo compositions containing 0.5% copolymer showed
a significantly better conditioning performance than linear
cationic polymers such as Styleze.RTM. CC-10 or Polymer JR.RTM.
400. In addition, the deposited copolymer layer from the hydrogel
of the invention also provides links between fibers after drying,
thus resulting in a styling or fixative effect, which remains
intact even after repeated rinsing with water after shampooing.
Conditioning and styling properties on hair can also be obtained
with cationic hydrogels of the following copolymers:
XL-acrylamide/DMAPMA, XL-poly(vinyl caprolactam) (PVCL)/DMAPMA and
XL-acrylamide/dimethylaminoethyl methacrylate (DMAEMA).
While the invention has been described with particular reference to
certain embodiments thereof, it will be understood that changes and
modifications may be made which are within the skill of the art.
Accordingly, it is intended to be bound only by the following
claims, in which:
* * * * *