JPS6033362B2 - new nail enamel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel nail enamel in which an acrylic resin made of a mixture of a methacrylic ester copolymer and a methacrylic ester/acrylic ester copolymer is used as a film forming agent.

Conventionally, nitrocellulose is the best raw material used as a film-forming agent for nail enamel, and in order to improve gloss, adhesion, shrinkage, and flexibility, alkyd resins, allylsulfonamide formaldehyde resins, Resins such as acrylic resins, epoxy resins, and rosin-modified resins are generally used in combination as coating aids.

However, since nitrocellulose is highly flammable and burns explosively, extreme care must be taken in terms of fire prevention when storing and transporting it as a raw material for nail enamel, or handling it during the manufacturing process of nail enamel. It is extremely undesirable to use it as a film-forming agent, which is the main component of enamel.

For example, it is said that flammability of nitrocellulose can be prevented by containing 20% or more of water, which is not normally used as a solvent for nail enamel.
In addition, nitrocellulose has the disadvantage that it tends to naturally decompose, discolor, and become brittle when exposed to sunlight, and this tendency is particularly accelerated by the presence of certain acids. This has the disadvantage that it causes a decrease in the viscosity of nail enamel products and increases the sedimentation rate of pigments, etc. From this standpoint, various proposals have been made for the purpose of replacing nitrocellulose as a film-forming agent or reducing the amount of nitrocellulose used.

For example, there are copolymers of methyl methacrylate and hexyl methacrylate, copolymers of vinyl acetate and hydroxy lower alkyl acrylate, and chlorinated polyethylene, and acrylic resins in particular have potential as coating aids. However, they generally have drawbacks such as brittleness, poor adhesion, and poor pigment affinity, and have not yet been put into practical use. On the other hand, large amounts of toluene are used as a type of diluent in nail enamel solvents.
Such aromatic hydrocarbons generally have acute toxicity associated with narcotic effects, and there are concerns about chronic poisoning that causes symptoms such as pernicious anemia, so it is desirable to significantly reduce the toluene content in the production and use of nail enamel. It is rare.

The inventor of the present invention should solve this problem.As a result of intensive research,
Methacrylic acid ester copolymer and methacrylic acid ester copolymer
It has been recognized that certain acrylic resin mixtures consisting of acrylic acid ester copolymers are excellent film-forming agents, do not require special film aids or plasticizers, and can significantly reduce the amount of toluene in nail enamel solvents. , completed the invention.

The first object of the present invention is to provide a film-forming agent for nail enamel that can replace nitrocellulose. The second object is to provide a nail enamel that can significantly reduce the toluene content in the nail enamel solvent. The third objective is to provide a nail enamel with excellent gloss, adhesion, light resistance, stability over time, safety, flexibility, film hardness, abrasion resistance, water resistance, etc. That is, in the present invention, methyl methacrylate and/or ethyl methacrylate is 35 to 65
A methacrylic acid ester copolymer consisting of 65 to 35 weight % of propyl methacrylate and/or butyl methacrylate, 50 to 85 weight % of methyl methacrylate and/or ethyl methacrylate, and methyl acrylate and/or ethyl methacrylate. Or, it is a novel nail enamel characterized by containing as a film forming agent an acrylic resin mixture with a methacrylate ester/acrylate ester copolymer comprising 50 to 15% by weight of ethyl acrylate.

In addition to the above-mentioned film-forming agent, the nail enamel of the present invention contains conventionally known raw materials for nail enamel, such as pigments, solvents, film auxiliaries, plasticizers, dyes, pearling agents, anti-settling agents, and ultraviolet light inhibitors. Constructed by combining.

The film forming agent applied to the present invention is an acrylic resin made of a mixture of a methacrylic ester copolymer and a methacrylic ester/acrylic ester copolymer,
It has the characteristics described below.

That is, the above methacrylic acid ester copolymer contains 35 to 65 methyl methacrylate and/or ethyl methacrylate.
% by weight and 65 to 35% by weight of propyl methacrylate and/or butyl methacrylate.

Here, if methyl methacrylate and/or ethyl methacrylate is less than 35% by weight, but propyl methacrylate and/or butyl methacrylate is more than 65% by weight, the hardness of the nail enamel film decreases. On the other hand, if methyl methacrylate and/or ethyl methacrylate exceeds 65% by weight, that is, if propyl methacrylate and/or butyl methacrylate is less than 35% by weight, the nail enamel film becomes brittle and its flexibility decreases. Not only that, but the adhesion with nails also decreases. Preferably methyl methacrylate and/or
Or ethyl methacrylate is 40 to 60% by weight, and propyl methacrylate and/or butyl methacrylate is 60 to 60% by weight.
4% by weight. More preferably 45 to 55% by weight of methyl methacrylate and/or ethyl methacrylate,
55-45% by weight of propyl methacrylate and/or butyl methacrylate. Note that propyl methacrylate refers to n-propyl methacrylate or isopropyl methacrylate, and butyl methacrylate refers to n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, and tertiary-butyl methacrylate. In addition, the above methacrylic acid ester/acrylic acid ester copolymer contains 50% of methyl methacrylate and/or ethyl methacrylate.
~85% by weight and 50~15% by weight of methyl acrylate and/or ethyl acrylate.

Here, if the amount of methyl methacrylate and/or ethyl methacrylate is less than 5% by weight, that is, if the amount of methyl acrylate and/or ethyl acrylate exceeds 5% by weight, the hardness of the nail enamel film not only decreases but also decreases. , When using nail enamel, the stringiness becomes too large and it is not possible to apply it beautifully to the nail. On the other hand, if the content of methyl methacrylate and/or ethyl methacrylate exceeds 85% by weight, that is, if the content of methyl acrylate and/or ethyl acrylate is 15% by weight, the nail enamel film becomes brittle and the adhesion to the nail becomes difficult. Sexuality becomes worse. Preferably methyl methacrylate and/or ethyl methacrylate is 55 to 8% by weight and methyl acrylate and/or ethyl acrylate is 45 to 2% by weight.
% by weight. More preferably, methyl methacrylate and/or ethyl methacrylate is 60 to 75% by weight, and methyl acrylate and/or ethyl acrylate is 40 to 2% by weight.
It is 5% by weight. The mixing weight ratio of the above methacrylate ester copolymer and the above methacrylate ester/acrylate ester copolymer is such that the methacrylate ester copolymer is 60 to 9% by weight, and the methacrylate ester/acrylate ester copolymer is 60 to 9% by weight. Preferably, the incorporation is between 40 and 1% by weight.

When the mixing weight ratio of methacrylic acid ester copolymer/methacrylic acid ester/acrylic ester copolymer is less than 60 to 40, the hardness of the nail enamel film decreases, and furthermore, the nail enamel has poor stringability. It is not desirable because it comes out. On the other hand, the mixing weight ratio is 90/10
If it exceeds this, the nail enamel film becomes brittle and its adhesion to the nail deteriorates. More preferably, the mixing ratio is
The methacrylate ester copolymer is 70 to 8% by weight and the methacrylate/acrylate ester copolymer is 3% by weight.
0-2% by weight. The method for incorporating the above acrylic resin mixture into nail enamel may include dissolving the methacrylic acid ester copolymer and the methacrylic acid ester/acrylic acid ester copolymer individually in a nail enamel solvent; The seed copolymer may be blended by a thickening method or the like and then dissolved in a nail enamel solvent. The content of such an acrylic resin mixture in the nail enamel may be adjusted to 20 to 45% by weight.

If the amount is less than 2% by weight, the viscosity of the nail enamel is too low, which not only deteriorates the brushability but also makes it impossible to obtain a nail enamel film of a predetermined thickness.

If it exceeds 45% by weight, the viscosity of the nail enamel will be too high and stringiness will appear, making it impossible to apply it beautifully to the nails.

Further, the average molecular weight of the acrylic resin is not particularly limited, but from the viewpoint of film-forming ability and solubility, a number average molecular weight of 15,000 to 200,000 is preferable.

Film auxiliary agents, plasticizers, and ultraviolet light inhibitors, which are normally used in nail enamel to cover various drawbacks of film-forming agents, are not particularly required in the present invention, but they adjust the viscosity of nail enamel. Alternatively, in order to improve affinity with pigments, for example, nitrocellulose,
Epoxy resins, polyamide resins, alkyd resins, rosin-modified resins, maleic acid resins, cellulose acetate butyrate, polyethylene resins, polypynylacetate resins, and the like can also be used.

Preferred are nitrocellulose, epoxy resin, alkyd resin, rosin-modified resin, maleic acid resin, or cellulose acetate butyrate. The amount of these coating aids used is 3 parts by weight or less per 100 parts by weight of the acrylic resin mixture which is the film forming agent of the present invention. If the coating aid is used in an amount exceeding 3 parts by weight, it not only impairs the characteristics of the present invention such as gloss and fire resistance, but also causes problems in compatibility, which is undesirable.

In addition, the nail enamel solvent of the present invention includes acetic acid esters (for example, ethyl acetate, butyl acetate,
amyl acetate, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), aromatic hydrocarbons (e.g., toluene, xylene, etc.), and is used as a coating aid or processed pigment used in nail enamel. Co-solvents or diluents of alcohols (e.g., ethyl alcohol, propyl alcohol, butyl alcohol, etc.) or glycol ethers (e.g., ethyl cellosolve, etc.) may be used depending on the type of alcohol or as necessary for viscosity adjustment. However, from the viewpoint of medical health management during the production and use of nail enamel, it is preferable to avoid the use of aromatic hydrocarbons as much as possible, and they may be used as needed to add coating aids, etc. However, in the present invention, the objective can be achieved with 30 parts by weight or less based on 10 parts by weight of the solvent.

In the present invention, there is no particular need for film aids, plasticizers, or ultraviolet light inhibitors that are contained in conventional nail enamels that use nitrocellulose as a film-forming agent.
If an anti-settling agent such as a bentonite quaternary ammonium cation-modified compound is not used, the solvent system can be constructed without the addition of aromatic hydrocarbons. Conventionally known pigments can be used as the pigments added to the nail enamel of the present invention, but considering good dispersibility or anti-sedimentation properties of the pigments, rosin ester, cellulose acetate butyrate, cellulose acetate, ethyl cellulose, or vinyl chloride/vinyl acetate are preferred. It is preferable to use a processed pigment whose surface is coated with a copolymer.

Since the thus obtained nail enamel of the present invention uses acrylic resin instead of the conventional nitrocellulose as a film-forming agent, it not only eliminates all the fire safety precautions and disadvantages of nitrocellulose, but also A coating aid that has been used in conjunction with nitrocellulose,
Gloss, adhesion, light resistance, stability over time, flexibility, film hardness, etc. without the need for plasticizers or UV inhibitors.
We can provide nail enamel with excellent wear resistance, water resistance, safety, etc.

In addition, since nail enamel can be provided by using aromatic hydrocarbons such as toluene, which have been used in large quantities as diluents, or in very small amounts, it is possible to reduce health risks during the production or use of nail enamel. It can be said that this nail enamel has excellent management safety. The present invention will be explained in more detail below using Examples. In addition, the test method in the examples is as follows. Pencil hardness is JISK540
Measured according to 0 "General Test Methods for Paints". However, the weight load was 300 mm, nail enamel was uniformly applied to a nylon plate, and after air drying at room temperature for 24 hours, the pencil hardness was measured. For maneuverability, nylon plate (thickness 0.5 skin x width 1
Apply nail enamel evenly to 5 willows x 4 lengths),
After drying for 2 hours at room temperature, the nylon plates are stacked once a day by overlapping both ends of the nylon plates.
It was bent 180 degrees to form a letter shape and judged based on the period during which cracks appeared.

◎ means excellent, 0 means good, △ means good, and × means bad. Adhesion was measured as follows.

Apply nail enamel evenly to the nylon board, air dry for 2 hours at room temperature, then cut 11 lines in a vertical and horizontal criss-cross pattern at 2 skin intervals with a knife until they reach the main surface of the nylon board. Then, apply adhesive cellophane tape with a width of 25 willow to the notch of the goban while pressing it. After that, peel off the cellophane tape that was attached all at once. Further, when the operation consisting of applying and peeling off the cellophane tape was repeated twice, the adhesion was determined based on how many of the 100 goblets of the engraved nail enamel film were peeled off. Here, the evaluation is ◎ if the number of peeled goban pieces is 5 or less, ○ if it is 6 or more and 1 or less, △ if it is 11 or more and less than 3, and △ if it is 30 or more. is indicated with an x. Glossiness was measured using a Gardner type gloss meter at incident angles of 20 degrees, 45 degrees, and 7 degrees.
Judgment was made by measuring the specular gloss at 5 degrees. That is, nail enamel was uniformly applied to a smooth glass plate, and after air-drying at room temperature for 24 hours, the specular reflection intensities of the above three types were measured, and the specular reflection intensity measured only on the glass plate was set as 100. The specular gloss was calculated for each incident angle. Here, the gloss evaluation is based on the average value of the three types of specular gloss of 50.
The following cases were rated as acceptable, those with a score of 51 to 55 were graded as good, and those with a grade of 56 or higher were graded as excellent. Example 1 Reflux condenser, dropping funnel,
Add 4 liters of ethyl acetate to a 4-necked flask equipped with a thermometer and a thermometer.
After heating to 770℃ under reflux, 1.0mL of penzoyl peroxide was added to a methacrylic acid ester mixture consisting of 220mL of methyl methacrylate (MMA) and 180mL of n-butyl methacrylate (BMA). After dissolving the monomer solution, the monomer solution was gradually and uniformly dropped into the four-necked flask over a period of 3 hours through the dropping funnel, and heating was continued at the above temperature.

2 hours after completion of the monomer solution dropwise addition and 4
After 50 hours of ethyl acetate and 0.5 hours of penzoyl peroxide.
The polymerization reaction was completed by adding a catalyst solution consisting of a mixture of monomers and esters to the reaction system over a period of 10 minutes through a dropping funnel, and then heating the reaction system for one period after the completion of the dropwise addition of the monomer solution. The thus obtained methyl methacrylate/butyl methacrylate copolymer (MMA/BMA
=55/45), the polymerization yield was 98.5%, and the number average molecular weight was 54,000. In addition, except for dropping a monomer solution of 40.1 mm (containing 1.0 mm of penzoyl peroxide) in which the mixed weight ratio of methyl methacrylate and butyl methacrylate was changed to the following copolymerization ratio, the above procedure was performed. MMA/BMA=30/70 in exactly the same polymerization operation as
35/65 40/60, 45/5 60/40, 6
Seven types of methacrylic acid ester copolymers consisting of 5/35 and 70/30 were obtained.

These polymerization yields were 98-99%. Additionally, 160 g of ethyl methacrylate (EMA), 240 g of isopropyl methacrylate (IPMA), and 1 g of penzoyl peroxide were added.
After dropping a monomer solution consisting of
A methacrylic acid ester copolymer of 0 was obtained. The polymerization yield was 98.8%. Example 2 Ethyl methacrylate (EMA) and methyl acrylate (M
Polymerization was carried out in exactly the same manner as in Example 1, except that 400.5 g of a monomer solution (containing 1.0 g of penzoyl oxide) was added dropwise, with the mixing weight ratio of A) changed to the following copolymerization ratio. By operation, ENA/MA=40/60 50/
50, 55/45 60/40, 75/2fu 80/20
Eight kinds of methacrylic acid ester/acrylic acid ester copolymers were obtained, consisting of , 85/1, 90/10.

These polymerization yields were also 98 to 99%. In addition, methyl methacrylate (MMA) 280 mg and ethyl acrylate (
A methacrylic acid ester/acrylic acid ester copolymer with MMA/EA=70/30 was prepared in exactly the same manner as above except that a monomer solution consisting of EA) 120 mm and penzoyl peroxide 1.0 mm was added dropwise. Obtained union.

The polymerization yield was 98.3%. Example 3 The methyl methacrylate/butyl methacrylate copolymer (MMA/BMA=
Using an acrylic resin mixture consisting of 70 parts by weight of 30/70 to 70/30) and 30 parts by weight of the methyl methacrylate/ethyl acrylate copolymer (MMA/EA=70/30) obtained in Example 2. Nail enamels having the formulations shown in Table 1 were prepared.

In addition, for comparison purposes, representative conventional products using nitrocellulose as a film-forming agent were prepared as shown in Table 2. Table 3 shows the characteristic values of the nail enamel thus obtained. In addition, the product of the present invention also exhibited excellent stability over time compared to conventional products. Table 1 Table 2 Table 3 Example 4 The ethyl methacrylate/isopropyl methacrylate copolymer (EMA/I) obtained in Example 1 was used as a film forming agent.
Parts by weight of PMA=40/60) 8 and the ethyl methacrylate/methyl acrylate copolymer EM obtained in Example 2
A/MA=40/60 to 90/10) 2 parts by weight was used, and the acrylic resin mixture of Example 3 was replaced with the above, but the first
Nail enamels having the formulation examples shown in the table were prepared.

Table 4 shows the characteristic values of the obtained nail enamel. Fourth
Table Example 5 As a film forming agent, the methyl methacrylate/butyl methacrylate copolymer (MMA/BMA=
Example 3 was prepared by using an acrylic resin mixture obtained by mixing ethyl methacrylate/methyl acrylate copolymer (EMA/MA=75/25) at a weight ratio as shown in Table 5. Nail enamels having the formulations shown in Table 1 were prepared in the same manner as in Example 3, except that the acrylic resin mixture was replaced with the one described above.

Table 5 shows the characteristic values of the obtained nail enamel. Fifth
Table Examples 6 to 12 As a coating aid, nitrocellulose (RSI/4 seconds),
Epoxy resin (Japan Ciba-Geigy ARALDITE, G
Y-250), alkyd resin (Arakawa Chemical Co., Ltd. Arakido 400), o-gin modified resin (Arakawa Chemical Co., Ltd. Abietic Acid Glycerin Ester AAL), maleic acid resin (Hitachi Chemical High Crack 40M) or cellulose acetate butyrate (Eastman Co., Ltd.) Table 6 shows examples 6 to 12 of formulation and preparation of nail enamel using Kodak CAB-531-1).

However, as a film forming agent, butyl methacrylate methylate copolymer (MMA/BMA=45/
55) and the methyl methacrylate/ethyl acrylate copolymer (MMA/EA=70/30) obtained in Example 2
was used. Except for the nail enamel of Example 7, which had good gloss, all the nail enamel had excellent gloss and other characteristic values were satisfactory. Table 6

Claims (1)

[Scope of Claims] 1. A methacrylic acid ester copolymer consisting of 35 to 65% by weight of methyl methacrylate and/or ethyl methacrylate and 65 to 35% by weight of propyl methacrylate and/or butyl methacrylate; A film is coated with an acrylic resin mixture of a methacrylate/acrylate copolymer consisting of 50 to 85% by weight of methyl acrylate and/or ethyl methacrylate and 50 to 15% by weight of methyl acrylate and/or ethyl acrylate. A new nail enamel characterized by containing it as a forming agent. 2. The methacrylate ester copolymer contains 40 to 60% by weight of methyl methacrylate and/or ethyl methacrylate and 60% by weight of propyl methacrylate and/or butyl methacrylate.
40% by weight of the new nail enamel according to claim 1. 3. Methacrylic acid ester acrylic ester copolymer is a copolymer of 55 to 80% by weight of methyl methacrylate and/or ethyl methacrylate and 45/20% by weight of methyl acrylate and/or ethyl acrylate. A novel nail enamel according to claim 1. 4. Claims 1 to 3, wherein the acrylic resin mixture is a mixture of 60 to 90% by weight of a methacrylic ester copolymer and 40 to 10% by weight of a methacrylic ester/acrylic ester copolymer. New nail enamel. 5. Claims 1 to 3, wherein the acrylic resin mixture is a mixture of 70 to 80% by weight of a methacrylic ester copolymer and 30 to 20% by weight of a methacrylic ester/acrylic ester copolymer. New nail enamel. 6. Claims 1 to 5, wherein the content of the acrylic resin mixture in the nail enamel is 20 to 45% by weight.
New nail enamel described in section. 7 As a film auxiliary agent for the film forming agent, nitrocellulose, epoxy resin, alkyd resin, rosin modified resin,
The novel nail enamel according to claim 1, which uses maleic acid resin or cellulose acetate butyrate. 8. Claim 7, wherein the content of the coating aid is 30 parts by weight or less based on 100 parts by weight of the acrylic resin mixture.
Okinawa nail enamel as described in the section. 9. The novel nail enamel according to claim 1, which contains at least one selected from acetic acid esters, ketones, and aromatic hydrocarbons as a true solvent. 10. The nail enamel according to claim 9, wherein the aromatic hydrocarbon content is 30 parts by weight or less based on 100 parts by weight of the solvent. 11. The novel nail enamel according to claim 1, which uses a processed pigment surface-treated with rosin ester, cellulose acetate butyrate, cellulose acetate, ethyl cellulose, or vinyl chloride/vinyl acetate copolymer as the pigment.