Drug – bio-affecting and body treating compositions – Manicure or pedicure compositions
Reexamination Certificate
1999-07-14
2001-01-23
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Manicure or pedicure compositions
C424S061000, C424S401000
Reexamination Certificate
active
06177065
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention belongs to the field of aqueous nail enamel composition which contains no organic solvent, is excellent in safety for human body and long-term storage stability, and has beautiful color and gloss, and high strength and adhesion of coating film.
Conventional nail enamel compositions have the composition similar to that of organic solvent type paints. For example, they are usually composed of a resin such as a nitrocellulose and an alkyd resin, a pigment, a plasticizer and an organic solvent.
That is, the conventional nail enamel compositions are such that a pigment as a colorant is enclosed in a resin and suspended in an organic solvent, and the suspension is coated by some means and the organic solvent is volatilized to form a film. In this case, hardness of the film formed is adjusted by the remaining plasticizer. The film after use is removed by an organic solvent capable of dissolving the film.
However, since the nail enamel of the above composition contain organic solvents and plasticizers, they are used taking into consideration the restriction in use due to noxiousness to human body of the chemical substances used, the flammability of compounds in view of environmental safety, and the odor of organic solvents.
Under the circumstances, development of aqueous nail enamel compositions containing no organic solvent is demanded, and intensive effort for the development is exerted.
The present technical standard of means for making aqueous nail enamel compositions can be summarized as follows:
(1) To use water-soluble or water-dispersible resins as the constituting resins.
(2) To use organic solvents which are miscible with water as the solvents.
(3) To use hydrophilic compounds as the plasticizers.
(4) To use compounds like the above (3) as film-forming aids employed in using emulsion resins.
These efforts of development of aqueous nail enamel compositions are disclosed in Japanese Patent Nos.2686880 and 2115767 and JP-A Hei 8(1996)-225434.
However, even if the above means are employed, the conversion of the organic solvent type nail enamel compositions to aqueous nail enamel compositions still has the following technical problems to be solved.
(1) In the case of using a water-soluble resin as the resin to enclose pigment, it is difficult to design the resin to have a high refractive index because of the conditions for rendering the resin water soluble, and consequently high gloss and clear color are difficult to obtain.
(2) It is difficult to enclose separately and completely a plurality of pigments with a water-soluble resin with no bare pigment to be present.
(3) A smooth surface cannot be obtained without using a water-soluble organic solvent or a film-forming aid, and it is difficult to obtain a nail enamel composition comprising solely water.
(4) It is difficult to obtain a long-term storage stability for aqueous pigment dispersion.
(5) It is difficult to give a goodly endurable adhesive force to a nail having an oily surface using a hydrophilic resin.
SUMMARY OF THE INVENTION
The object of the present invention is to solve the above-mentioned five problems, the solution of which is essential for obtaining a practically usable aqueous nail enamel composition and thus to provide a stable aqueous nail enamel composition.
The technical idea of the present invention can be summarized as follows:
(1) Linear polymers are suitable for covering the surface of pigment, and since linear polymers are greater than branched polymers in entanglement between molecules at the same molecular weight, it can be expected that when the pigment is once enclosed with the linear polymer, the pigment is difficult to be bared.
(2) In the above case, it can be expected that a pigment dispersion having high gloss and clear color is obtained using a linear polymer having a phenyl group capable of increasing refractive index as the polymer for enclosing the pigment.
(3) Different polymers are used as the polymer which encloses the pigment and the polymer which has the function to water-solubilize or disperse in water the enclosed pigment, and the pigment is sufficiently dispersed in the polymer which is to enclose the pigment and this dispersion is used.
(4) If the polymer having the function to water-solubilize or disperse in water the enclosed pigment contains an organic solvent or a film-forming aid, since these compounds are merely mixed with the polymer and have the properties to govern the dissolving power of the polymer, pH of the system varies due to some external force, namely, evaporation, change in temperature, or absorption of an acidic substance such as carbon dioxide, and hence the dissolved state is disturbed to make the solution unstable with time. Therefore, unnecessary materials should not be allowed to be present.
(5) In order to secure adhesion to an oily surface, it is a matter of course that the polymer having the dispersing function should be hydrophobic, but, in this case, acid value or amine value decreases, resulting in reduction of dissolving power and increase of instability. In order to avoid the problems, it is considered that electrolytes should be excluded as much as possible for the removal of the salting-out action of impurity electrolytes which is a hindrance factor.
The inventors have made efforts to establish the above technical means and accomplished the present invention.
That is, the present invention is a method for producing an aqueous nail enamel composition comprising the following procedure: An aqueous mixture which comprises, as essential components, water and a pigment of 3 &mgr;m or less in average particle size at a concentration of the pigment of 60% or less and is previously subjected to contact treatment with a substance having an ion exchangeability is kneaded under heating with a polyester polymer having a chemical structure containing a phenyl group and having a weight-average molecular weight of 2000-20000 and a softening point of 120° C. or lower in the state of the polymer being molten and simultaneously the volatile matter contained is removed under reduced pressure; the resulting mixture (A) comprising the polyester polymer and the pigment dispersed in the polyester polymer, said dispersed pigment having finally the inherent average particle size, is dissolved in an organic solvent at a concentration of the mixture (A) of 50% by weight or less; then the solution is mixed with an organic solvent solution (B) containing 80% or less of a resin containing 1-5 meq/g of a functional group capable of being dissociated to a cation or an anion; then the resulting mixture is neutralized and allowed to contact with a substance having ion exchangeability to remove ionic impurities before and/or after carrying out phase inversion by dilution with addition of water; the organic solvent is distilled off; and the residue is again allowed to contact with a substance having ion exchangeability to obtain an aqueous nail enamel composition comprising a color polymer composition dissolved in water alone as an essential component and containing less ionic impurities and substantially no organic solvent and film-forming aid.
It can be additionally said that if impurity electrolytes are not contained, there is no need to take the trouble of carrying out the means to harden the dispersed particles for inhibition of coalescence and form a film with the aid of a film-forming agent.
DETAILED DESCRIPTION OF THE INVENTION
The technical idea of the present invention will be explained in more detail.
For the prevention of pigment from being suspended alone in a bare state in water, the first means of the present invention is to disperse the pigment in a phenyl group-containing polyester polymer which has nearly the linear form suitable for enclosing the pigment and has flexibility, is insoluble in water, and has a great refractive index, in such a state as faithful to the distribution of the particle size which the pigment inherently possesses.
The above means can be carried out by a high-speed dispersing machine such as
Sekine Masahiro
Sunamori Takashi
Tamazawa Mitsuo
Di Nola-Baron Liliana
Page Thurman K.
Stevens Davis Miller & Mosher L.L.P.
Taisei Chemical Industries, Ltd.
LandOfFree
Method for producing aqueous nail enamel composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing aqueous nail enamel composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing aqueous nail enamel composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2490283