JP2947896B2 - Primer for nail enamel - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a novel base material for nail enamel, and more particularly, to applying nail enamel containing nitrocellulose as a main film-forming agent to nails. The present invention relates to a base material for nail enamel, which is applied to the surface of a nail to prevent the nail enamel from directly contacting the nail, and is effective for preventing discoloration of the nail.

[Conventional technology and its problems] Conventional nail enamels include nitrocellulose,
The mainstream is a solvent system based on a resin such as an alkyd resin and an organic solvent such as plasticity and organic solvents such as butyl acetate and ethyl acetate.

These solvent-based nail enamels, in terms of gloss of the coating film, difficulty of scratching, peeling over time, etc.,
Although it has excellent properties, it has problems such as flammability and solvent odor due to the use of a large amount of low-boiling organic solvent.Furthermore, long-term use may cause discoloration or cracking of nails. Is a problem that has a serious adverse effect.

As means for solving such a problem, JP-A-60-23
No. 7010 uses a water-soluble polymer as a primer to prevent the nail enamel from coming into direct contact with the nails and to remove the entire coating of the primer when removing it. A primer has been proposed. However, as far as the authors have performed additional tests, since the base material is water-soluble, even when it is not desired to remove it, it becomes very easy to drop after washing his / her hands, which is not practical.

[Means for Solving the Problems] The inventors of the present invention have conducted intensive studies to satisfy both the safety requirements for nails and the physical properties such as water resistance and durability over time. If a base agent containing an aqueous polymer emulsion with good adhesion to nails is applied to the nails before the application of nail enamel composed mainly of nitrocellulose, there will be no trouble such as discoloration of the nails and And good water resistance and the like.

That is, the present invention provides a base material for nitrocellulose-based nail enamel, which comprises 5 to 60% by weight as a solid content of an aqueous polymer emulsion.

The aqueous polymer emulsion used in the base material for nail enamel of the present invention may be any of anionic, cationic, nonionic and amphoteric as long as it has a film-forming property. Are particularly preferred.

The cationic polymer emulsion includes at least one or more monomers having a basic nitrogen and a polymerizable double bond (hereinafter, abbreviated as “cationic monomer”),
Preferably, it is prepared by appropriately combining and polymerizing another hydrophobic monomer having a polymerizable double bond (hereinafter abbreviated as “hydrophobic vinyl monomer”).

Examples of the cationic monomer include (meth) acrylic esters or (meth) acrylamides having a dialkylamino group such as N, N-dimethylaminoethyl (meth) acrylate and N, N-dimethylaminopropyl acrylateamide; Styrenes having a dialkylamino group such as N, N-dimethylaminostyrene and N, N-dimethylaminomethylstyrene; vinylpyridines such as 4-vinyllysine and 2-vinylpyridine; or alkyl halides, benzyl halides, Examples thereof include those quaternized with a known quaternizing agent such as alkyl or aryl sulfonic acid, or dialkyl sulfate.

On the other hand, the hydrophobic vinyl monomer copolymerizable with the cationic monomer is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, lauryl acrylate, methyl methacrylate, ethyl methacrylate, and methacrylic acid. (meth) acrylic esters such as n-butyl; styrene-based monomers such as styrene and chlorostyrene; N-substituted (meth) acrylamides such as t-butylacrylamide; and acrylonitrile and methacrylonitrile. Alternatively, it can be selected from two or more.

In the present invention, the mixing ratio of the cationic monomer and the hydrophobic vinyl monomer is 0.1 to 10% by weight of the former (hereinafter, referred to as “hydrophobic vinyl monomer”).
(Indicated simply by “%”), the latter is 90 to 99.9%, more preferably the former is 2 to 10%, and the latter is 90 to 98%.

If the amount of the cationic monomer is less than 0.1%, it is difficult to obtain a stable polymer emulsion.
It is difficult to obtain a practically water-resistant polymer emulsion.

As the polymerization method, known emulsion polymerization or non-emulsifier polymerization can be employed, but it is preferable to employ phase inversion emulsion polymerization, particularly from the viewpoint of water resistance. The non-emulsifier polymerization is carried out by a known polymerization method such as soap-free polymerization using a reactive emulsifier or heterogeneous polymerization in an aqueous medium containing no emulsifier.

In the present invention, a particularly preferred cationic polymer emulsion obtained by phase inversion emulsion polymerization is a cationic monomer emulsion of 0.1.
It is obtained by adding water to an organic solvent solution of a copolymer obtained by copolymerizing 1 to 10% and a hydrophobic vinyl monomer of 90 to 99.9%, and then distilling off the organic solvent. Here, the organic solvent refers to a solvent having a lower boiling point than water and miscible with water, such as lower alcohol and methyl ethyl ketone.

In order to copolymerize a cationic monomer and a hydrophobic vinyl monomer copolymerizable therewith, a known radical initiator is used, and copolymerization is performed by a known polymerization method such as a solution polymerization method, a bulk polymerization method, and a precipitation polymerization method. It should be done. Since the phase is changed to an aqueous phase later, it is preferable to immediately proceed to the next step after the polymerization using a solution polymerization method. After the polymerization, the copolymer obtained before the phase inversion to an aqueous system can be purified by a known method. The weight average molecular weight of the obtained copolymer is 1
0,000 to 500,000 is preferred, and 50,000 to 200,000 is more preferred. If the weight average molecular weight is less than 10,000, physical properties of the coating film are inferior, and if it exceeds 500,000, phase inversion becomes difficult and an aqueous vinyl resin cannot be obtained.

When the basic amino nitrogen of the copolymer is not ionized, ionization is performed with a neutralizing agent as necessary.

When a monomer that is already a salt is used as the cationic monomer, ionization with a neutralizing acid is unnecessary, but otherwise, ionizing with a neutralizing acid is more irritating to nails and skin. It is preferable because it is small.

As the neutralizing acid, known acids may be used, for example, inorganic acids such as hydrochloric acid and sulfuric acid; and organic acids such as acetic acid, propionic acid, lactic acid, succinic acid, and glycolic acid.

Although the degree of neutralization is not limited, it is preferable to neutralize the obtained polymer emulsion so that the pH of the emulsion is around neutrality.

In order to invert the obtained copolymer into an aqueous phase and to form an aqueous polymer emulsion, the copolymer is made into a solution of an organic solvent such as an alcohol, a ketone, an ester or an ether, and water is added thereto. The organic solvent may be distilled off.

The concentration of the organic solvent solution is appropriately determined depending on the composition and molecular weight of the copolymer, but is usually 10 to 80%, preferably 20 to 70%.

Among the above-mentioned organic solvents, alcohol-based and / or ketone-based organic solvents are preferable because phase inversion can be performed well. In the case of the solution polymerization method, the solvent for polymerization can be arbitrarily selected, but it is preferable to use the above-mentioned organic solvent because the steps from polymerization to phase inversion are simplified.

Examples of the alcohol solvent used in the present invention include methanol, ethanol, n-propanol, isopropanol and the like, and preferably isopropanol.

Examples of the ketone-based solvent include acetone, methyl ethyl ketone, diethyl ketone, and the like, and preferred is methyl ethyl ketone. These may be used alone or as a mixture of two.

The phase inversion from the organic solvent solution to the aqueous system as described above can be performed by a conventionally known method, and the organic solvent solution is stirred, and water may be added at a temperature of room temperature to 80 ° C, preferably room temperature to 60 ° C. . As described above, the organic solvent is distilled off under normal pressure or reduced pressure after phase inversion to an aqueous system, whereby a cationic polymer emulsion by phase inversion emulsion polymerization is obtained.

The cationic phase change emulsion polymerization polymer emulsion thus obtained has suitable film-forming properties and coating strength when used as a base material for nail enamel. Further, since the composition does not contain a surfactant, the resulting coating film has excellent water resistance.

In addition, two or more cationic polymer emulsions obtained by separately polymerizing can be used as a mixture. Furthermore, seed polymerization can be carried out in multiple stages in the presence of a cationic polymer emulsion to be used as a composite polymer emulsion having a multilayer structure.

The base material for nail enamel of the present invention is prepared by blending the above cationic polymer emulsion as a film-forming base. The blending amount of the cationic polymer emulsion is preferably about 5 to 60% (as solid content).

In the base material for nail enamel of the present invention, in addition to the cationic polymer emulsion described above, a preservative, a fragrance, a plasticizer, a film-forming auxiliary, a thickener, a wetting agent, an antifoaming agent, a filler and the like are blended. be able to.

As the plasticizer and film-forming auxiliary, known ones such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, butyl carbitol, cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, and hexylene glycol can be used. From the viewpoints of storage stability and water resistance of the coating film, the amount is preferably 0 to 15%.

Known thickeners can be used, but since the charge of the polymer emulsion is cationic, nonionic water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyethylene oxide, methylcellulose, hydroxyethylcellulose, and hydroxypropylmethylcellulose can be used. Thickeners, cationized guar gum, cationized cellulose, and the like, which are cationically modified, can also be used.

[Effects of the Invention] Since the polymer emulsion used in the present invention is cationic, it has excellent adhesion to nails, and even when used as it is as a nail enamel, it shows fairly good water resistance and durability over time. When a nitrocellulose-based nail enamel is applied using a polymer emulsion as a base material, the water resistance and durability are further improved, and a performance without any grandchild is obtained as compared with a conventional base coat coated with a nail enamel.

Moreover, since the nitrocellulose-based nail enamel is not in direct contact with the nail, even when used for a long period of time, no trouble such as discoloration of the nail occurs and the nail is excellent.

[Examples] Next, the present invention will be specifically described with reference to Synthesis Examples of cationic polymer emulsions, Examples and Comparative Examples of base materials for nail enamels, but it goes without saying that the present invention is not limited to these. . All parts and percentages in each example are by weight unless otherwise specified.

Synthesis Example 1 A reactor equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube was charged with 50 parts of methyl ethyl ketone.
Dissolved oxygen was removed by flowing nitrogen gas.

On the other hand, 35 parts of methyl ethyl ketone, 56 parts of methyl methacrylate, 40 parts of n-butyl acrylate, N,
4 parts of N-dimethylaminoethyl methacrylate and 0.2 parts of azobisisobutyronitrile were charged.

Under stirring, the temperature in the reactor was raised to 80 ° C., and a solution of the above monomer and radical initiator in methyl ethyl ketone was dropped from the dropping funnel over 2.5 hours. End of monomer dropping 2
After an hour, a solution of 0.2 parts of azobisisobutyronitrile dissolved in 10 parts of methyl ethyl ketone was added. After aging at the same temperature for 3 hours, a solution prepared by dissolving 0.1 part of azobisisobutyronitrile in 5 parts of methyl ethyl ketone was added again.
The reaction was continued for an hour to obtain a copolymer.

A part of the obtained copolymer was isolated and its molecular weight was measured by gel permeation chromatography. The weight average molecular weight was 75,000. The calibration curve of gel permeation chromatography was prepared using polystyrene as a standard substance (solvent: tetrahydrofuran).

After the reaction was completed, the copolymer solution was cooled to room temperature, and lactic acid 5.
Neutralize by adding 6 parts, and further add ion-exchanged water 4 with stirring at 300 rpm.
After adding 00 parts, methyl ethyl ketone was distilled off at 40 ° C. under reduced pressure, and water was further distilled off at 50 ° C. to obtain a polymer emulsion having a solid content of 30%.

Synthesis Example 2 A reactor was equipped with a stirrer, a reflux condenser, a dropping funnel, a thermometer, and a nitrogen inlet tube.
Dissolved oxygen was removed by flowing nitrogen gas.

Meanwhile, 35 parts of isopropanol and styrene were added to the dropping funnel.
50 parts, 46 parts of ethyl acrylate, 4 parts of N, N-dimethylaminopropylacrylamide and 0.2 parts of azobisisobutyronitrile were charged.

Under stirring, the temperature in the reactor was raised to 80 ° C., and a solution of the above monomer and radical initiator in methyl ethyl ketone was dropped from the dropping funnel over 2.5 hours. End of monomer dropping 2
After an hour, a solution of 0.2 parts of azobisisobutyronitrile dissolved in 10 parts of methyl ethyl ketone was added. After aging at the same temperature for 3 hours, a solution prepared by dissolving 0.1 part of azobisisobutyronitrile in 5 parts of methyl ethyl ketone was added again.
The reaction was continued for an hour to obtain a copolymer.

A part of the obtained copolymer was isolated, and the molecular weight was measured by gel permeation chromatography. As a result, the weight average molecular weight was 75,000. The calibration curve of gel permeation chromatography was prepared using polystyrene as a standard substance (solvent: tetrahydrofuran).

After the reaction was completed, the copolymer solution was cooled to room temperature, and acetic acid 5.
After neutralizing by adding 6 parts, further stirring at 300 rpm, adding 400 parts of ion-exchanged water, distilling off methyl ethyl ketone at 40 ° C. under reduced pressure, and further concentrating by distilling off water at 50 ° C.,
A polymer emulsion having a solid content of 25% was obtained.

Example 1 Using the polymer emulsion of Synthesis Example 1, a base material for nail enamel having the following composition was obtained by a conventional method.

(Formulation) Polymer emulsion of Synthesis Example 1 80% Film-forming aid (carbitol) 7% Plasticizer (diethyl phthalate) 5% Cationized cellulose 1% Preservative 0.1% Ion-exchanged water 6.9% Example 2 Synthesis Example 2 Was used to obtain a base material for nail enamel having the following composition by a conventional method.

(Prescription) Polymer emulsion of Synthesis Example 2 85% Film forming aid (carbitol) 8% Plasticizer (diethyl phthalate) 5% Cationized cellulose 1% Preservative 0.1% Ion-exchange water 0.9% Comparative Example 1 The following composition Thus, a primer was prepared.

Polyvinyl alcohol 25% Polyvinylpyrrolidone 5% Glycerin 5% Ion-exchanged water 64.9% Preservative 0.1% Test example The properties of the nail enamel primers obtained in Examples 1 and 2 and Comparative Example 1 were examined by the following methods. The test was carried out by applying a test base agent to a nail or a nylon plate and then applying a commercially available nail enamel. As comparative products, an anionic polymer emulsion, Daitosol 5000-AD (manufactured by Daito Kasei Kogyo) (Comparative Example 2) and a commercially available base coat (Comparative Example 3) were used. Further, a comparison was also made when a commercially available nail enamel was used directly without using a base material (Comparative Example 4). Table 1 shows the results.

<Evaluation Method> (1) Adhesion Under the condition of a temperature of 25 ° C. and a humidity of 50 to 60%, the base material of the example or the comparative example of the present invention is applied to the nail and dried for 30 minutes. Further, a commercially available nail enamel was applied thereon and dried for 1 hour, and then the film was scraped off from the surface with a microspatula to evaluate the adhesiveness to nails.

(2) Water resistance 0.5 × 15 × 40mm under conditions of temperature 25 ℃, temperature 50-60%
Is applied to a nylon plate having a size of 5 mm and dried for 1 hour. Further, a commercially available nail enamel is applied thereon, dried for 1 hour, and then immersed in water at 35 ° C. for 1 hour to evaluate whether or not the coating film has deteriorated (white turbidity, swelling, softening, peeling, etc.). (Comparative Example 4 was evaluated without a base material) (3) Abrasion resistance A nylon plate coated with a base material and a commercially available nail enamel prepared in the same manner as in the water resistance of (2) was put into a ball mill for 5 minutes. Rotary stirring is performed to evaluate the state of the coating film (surface damage, peeling, etc.). (Comparative Example 4 was evaluated without a base material) The evaluation items (1) to (3) were determined as follows.

；: Extremely good ○: Good △: Normal ×: Poor (4) Long-term use test Six groups (60 in total) of female panelists were prepared, each group consisting of 10 to 10 persons. 2, Comparative Examples 1-4
No.2 basement and commercial nail enamel (Comparative Example 4 without base) was used for 2 months, and compared with the nails before use, the number of people with significant discoloration, cracking, etc. was examined. Was.

<result> As is evident from the results, the base property for nail enamel of the present invention is excellent in adhesive, water resistance and abrasion resistance, and almost no trouble such as discoloration to nails even after long-term use. I was not able to admit.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Akihiro Kondo 3-8-59 Nishihama, Wakayama-shi, Wakayama (56) References JP-A-55-28930 (JP, A) JP-A-60-237010 (JP, A JP-A-54-52736 (JP, A) JP-A-57-56410 (JP, A) JP-A-56-131513 (JP, A) JP-A-3-161420 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) A61K 7/04

Claims (3)

(57) [Claims] (1) A base material comprising an aqueous polymer emulsion in a solid content of 5 to 60% by weight and used for a nitrocellulose nail enamel. 2. The primer according to claim 1, wherein the aqueous polymer emulsion is a cationic polymer emulsion. 3. A cationic polymer emulsion is prepared by polymerizing at least one monomer having a basic nitrogen and a polymerizable double bond with a hydrophobic monomer having a polymerizable double bond. The base material according to claim 2, which is a base material.