JP4981184B1 - Photocurable gel nail primer and gel nail method - Google Patents

Abstract

An object of the present invention is to provide a base material for a photo-curing gel nail which not only has an excellent balance between adhesion to a nail and peelability, but also has a high curing speed and also has excellent adhesion to a gel nail layer laminated thereon. A gel nail method using the above is provided.
[MEANS FOR SOLVING PROBLEMS] A photocurable gel nail base material comprising the following components (A) to (F), and a gel nail method using the same. (A) 100 parts by weight of a polyether skeleton urethane methacrylate oligomer, (B) 20 to 60 parts by weight of an alicyclic (meth) acrylate monomer, (C) 5 to 20 parts by weight of an acrylamide monomer that is liquid at 25 ° C., ( D) 20 to 40 parts by weight of a bifunctional (meth) acrylate monomer having ethylene oxide in the molecule, (E) 0 part by weight or 0 to 1 part by weight of a trifunctional or higher polyfunctional monomer 5 to (F) a photopolymerization initiator 5 20 parts by weight.
[Selection figure] None

Description

The present invention relates to a base material for a photocurable gel nail and a gel nail method using the same.
In particular, it is not only excellent in the balance between adhesion to the nail and peelability, but also has a high curing speed, and further has excellent adhesion to the gel nail layer laminated thereon, It relates to the gel nail method used.

Conventionally, gel nails to be applied to nails (sometimes called nail polish) are solvent-type gel nails that are mainly composed of nitrocellulose or acrylic resin and dissolved in toluene, butyl acetate, or ethyl acetate. It was the target.
However, such a solvent-type gel nail has a problem that it is unfavorable for health and hygiene because the user sucks solvent vapor.

  Also, solvent-type gel nails usually require several tens of minutes for the solvent to scatter, so you can use your fingertips freely for a long time after gel nails are applied and until they dry and harden. There was also a problem that they could not.

In view of this, a photocurable gel nail composition that has a fast curing reaction and substantially does not contain a solvent has been proposed (see, for example, Patent Documents 1 and 2).
That is, Patent Document 1 discloses a photocurable solventless nail polish containing a polymerizable unsaturated group-containing compound and a photopolymerization initiator.

  Patent Document 2 discloses an artificial nail forming composition containing an ultraviolet curable resin and a photopolymerization initiator, and (1) the photopolymerization initiator includes an alkylphenone type, an acylphosphine oxide type, and a titanocene type. And (2) the artificial nail forming composition is cured by irradiating with ultraviolet light having a wavelength of 340 to 370 nm using an ultraviolet light emitting diode. A composition for artificial nail formation is disclosed.

JP 2002-161025 A (Claims) JP 2010-105967 A (Claims)

However, the photocurable gel nail composition described in Patent Documents 1 and 2 has an insufficient balance of adhesion to the nail and peelability, and the gel nail layer formed may be easily peeled off from the nail. On the contrary, there was a problem that it was difficult to peel off excessively.
That is, since the photocurable gel nail composition described in Patent Documents 1 and 2 forms a gel nail layer by directly applying to the nail, the gel nail layer has a predetermined level of hardness. Needless to say, there is also a demand for a balance between adhesion to the nail and peelability.
Therefore, it is practically difficult to exert all these characteristics uniformly, and in particular, there is a problem that the balance between adhesion to the nail and peelability tends to be insufficient.

Therefore, as a result of diligent investigation of the conventional problems, the present inventors can solve the above-mentioned problems by forming a predetermined underlayer on the nail and laminating a gel nail layer above the underlayer. And the present invention has been completed.
More specifically, a predetermined blend of a predetermined urethane methacrylate oligomer, a predetermined (meth) acrylate monomer, a predetermined acrylamide monomer, a predetermined bifunctional (meth) acrylate monomer, and a photopolymerization initiator. It has been found that the above-mentioned problems can be solved by using a photocurable gel nail base material that is contained in a ratio and that does not substantially contain a trifunctional or higher polyfunctional (meth) acrylate monomer.
That is, the object of the present invention is a photocurable gel nail that not only has an excellent balance between adhesion to the nail and peelability, but also has a high curing speed and also has excellent adhesion to the gel nail layer laminated thereon. An object of the present invention is to provide a base material for gel and a gel nail method using the same.

According to the present invention, a photocurable gel nail base material comprising the following components (A) to (F) is provided, and the above-described problems can be solved.
(A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate monomer 20-60 parts by weight (C) Acrylamide monomer which is liquid at 25 ° C. 5-20 parts by weight (D) molecule Bifunctional (meth) acrylate monomer with ethylene oxide inside
20 to 40 parts by weight (E) Trifunctional or higher polyfunctional (meth) acrylate monomer
0 parts by weight , or 0 to 1 part by weight
(However, 0 parts by weight are not included.)
(F) Photopolymerization initiator 5 to 20 parts by weight

That is, in the case of the photocurable gel nail primer of the present invention, since the predetermined urethane methacrylate oligomer is used as the component (A), the reactivity of the photocurable gel nail primer is suppressed within a predetermined range. And the adhesiveness of the base layer with respect to a nail | claw can be improved effectively.
Moreover, since it contains substantially no trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E), it is possible to effectively exhibit the adhesion of the foundation layer to the nail derived from the component (A). it can.
On the other hand, since a plurality of monomer components having excellent reactivity as the components (B) to (D) and a photopolymerization initiator as the component (F) are used in a predetermined blending ratio, the photocurable gel nail is used. It is possible to increase the reactivity of the base material for coating within a predetermined range, and to effectively improve the peelability while maintaining excellent adhesion to the nail of the base layer derived from the component (A).
Therefore, if it is the base agent for photocurable gel nails of this invention, the base layer excellent in the balance of the adhesiveness and peelability with respect to a nail | claw can be formed stably.
Moreover, if it is the base agent for photocurable gel nails of this invention, a cure rate will be quick and also it will be excellent in adhesiveness with the gel nail layer laminated | stacked upwards.
As a result, the gel nail layer laminated above the base layer can be effectively adhered to the nail through the base layer, while being easily peeled off together with the base layer at the time of peeling. Can do.
In the present invention, “bifunctional” means that one monomer has two functional groups having a polymerizable double bond, and “trifunctional” means that one monomer has a polymerizable double bond. It means having three functional groups having a bond.

Moreover, when comprising the base material for photocurable gel nails of this invention, let the weight average molecular weight of the polyether frame | skeleton urethane methacrylate oligomer which is (A) component be the value within the range of 10,000-50,000. It is preferable.
By comprising in this way, the shrinkage | contraction rate at the time of photocuring the base agent for photocurable gel nail can be reduced, and peelability can further be improved, maintaining the adhesiveness with respect to the nail | claw of a base layer. .

Moreover, when comprising the base material for photocurable gel nails of this invention, it is preferable that the alicyclic (meth) acrylate monomer which is (B) component is isobornyl methacrylate.
By comprising in this way, not only can the curing speed at the time of photocuring the photocurable gel nail base agent be made faster, but also excellent adhesion to the nail of the base layer derived from the component (A) While maintaining the above, the releasability can be further improved.

Further, in constituting the photocurable gel nail primer of the present invention, it is preferable that the acrylamide monomer that is liquid at 25 ° C. as the component (C) is hydroxyethylacrylamide.
By comprising in this way, peelability can further be improved, maintaining the outstanding adhesiveness with respect to the nail | claw of the base layer derived from (A) component.

Further, in constituting the base material for photocurable gel nail of the present invention, the bifunctional (meth) acrylate monomer having ethylene oxide in the molecule as component (D) is bisphenol A-ethylene oxide adduct diacrylate. Preferably there is.
By comprising in this way, peelability can further be improved, maintaining the outstanding adhesiveness with respect to the nail | claw of the base layer derived from (A) component.
In the following, “ethylene oxide” may be abbreviated as “EO”.

Further, in constituting the photocurable gel nail primer of the present invention, the photopolymerization initiator (F) is an acyl phosphine oxide compound, an α-hydroxyketone compound and a benzophenone compound, or It is preferable that any one is included.
By comprising in this way, the cure rate at the time of carrying out photocuring of the base agent for photocurable gel nails can be made still faster.

Moreover, another aspect of the present invention is a gel nail method using a photocurable gel nail primer, which comprises the following steps (1) to (5). .
(1) Step of preparing a photocurable gel nail primer containing the following components (A) to (F) (A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate Monomer 20-60 parts by weight (C) Acrylamide monomer which is liquid at 25 ° C. 5-20 parts by weight (D) Bifunctional (meth) acrylate monomer having ethylene oxide in the molecule
20 to 40 parts by weight (E) Trifunctional or higher polyfunctional (meth) acrylate monomer
0 parts by weight , or 0 to 1 part by weight
(However, 0 parts by weight are not included.)
(F) Photopolymerization initiator 5 to 20 parts by weight (2) Step of applying photocurable gel nail primer to nails (3) Photocuring the applied photocurable gel nail primer, Step for forming underlayer (4) Step for applying photocurable gel nail composition to underlayer (5) Step for photocuring applied photocurable gel nail composition to form gel nail layer

That is, according to the gel nail method of the present invention, since a predetermined photocurable gel nail base material is used, a base layer excellent in the balance between adhesion to the nail and peelability can be stably and in a short time. Can be formed.
Therefore, the gel nail layer laminated above the base layer can be effectively adhered to the nail through the base layer, and can be easily peeled together with the base layer at the time of peeling. .

In carrying out the gel nail method of the present invention, the photocurable gel nail composition in step (4) comprises the following components (A), (B), (D), (E ′), and (F) It is preferable to contain a component.
(A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate monomer 20-60 parts by weight (D) Bifunctional (meth) acrylate monomer having ethylene oxide in the molecule
20-40 parts by weight (E ′) Trifunctional or higher polyfunctional (meth) acrylate monomer 5-20 parts by weight (F) Photopolymerization initiator 5-20 parts by weight

  By implementing in this way, the adhesiveness of the gel nail layer with respect to a base layer can further be improved.

Moreover, when implementing the gel nail method of this invention, it is preferable that the polyfunctional (meth) acrylate monomer more than trifunctional which is (E ') component is dipentaerythritol hexaacrylate.
By carrying out in this way, it is possible to improve the hardness of the gel nail layer while maintaining the adhesiveness of the gel nail layer with respect to the underlayer, and to improve the durability of the gel nail layer.

FIG. 1 is a diagram for explaining the influence of the amount of component (B) on the adhesion and peelability of the underlayer. FIG. 2 is a diagram for explaining the influence of the amount of component (C) on the adhesion and peelability of the underlayer. FIG. 3 is a diagram for explaining the influence of the amount of component (D) on the adhesion and peelability of the underlayer. FIG. 4 is a diagram for explaining the influence of the amount of component (E) on the adhesion and peelability of the underlayer. FIGS. 5A to 5E are views for explaining a method of sequentially forming a base layer and a gel nail layer on the nail. FIGS. 6F to 6H are views for explaining a method of sequentially forming a base layer, a gel nail layer, and a clear coat layer on the nail.

[First Embodiment]
1st Embodiment of this invention is a base agent for photocurable gel nail characterized by including the following (A)-(F) component.
(A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate monomer 20-60 parts by weight (C) Acrylamide monomer which is liquid at 25 ° C. 5-20 parts by weight (D) molecule Bifunctional (meth) acrylate monomer with ethylene oxide inside
20 to 40 parts by weight (E) Trifunctional or higher polyfunctional (meth) acrylate monomer
0 parts by weight, or 0 to 1 parts by weight
(However, 0 parts by weight are not included.)
(F) Photopolymerization initiator 5 to 20 parts by weight Hereinafter, the components (A) to (F) that are the constituents of the first embodiment will be specifically described.

1. (A) Component: Urethane Methacrylate Oligomer (1) Type The photocurable gel nail primer of the present invention is characterized by containing a polyether skeleton urethane methacrylate oligomer as the component (A).
That is, the component (A) is a reaction product of a polyether skeleton polyol, an organic polyisocyanate compound, and hydroxymethacrylate.
The reason for this is that by using a polyether skeleton urethane methacrylate oligomer as the component (A), the reactivity of the photocurable gel nail base material is suppressed within a predetermined range, and the adhesion of the base layer to the nail is effective. This is because it can be improved.
Moreover, if it is a polyether frame | skeleton urethane methacrylate oligomer as (A) component, the reactivity of the base agent for photocurable gel nail is set to predetermined range by combination with (B)-(D) component etc. which are mentioned later. This is because the peelability can be effectively improved while maintaining excellent adhesion to the nail of the base layer derived from the component (A).
Therefore, by using the polyether skeleton urethane methacrylate oligomer as the component (A), it is possible to stably form an underlayer having an excellent balance of adhesion to the nail and peelability.

That is, if it is a polyether skeleton urethane methacrylate oligomer, compared with the polyether skeleton urethane acrylate oligomer, the volume shrinkage after photocuring is small, and the adhesion of the underlayer to the nail can be effectively improved. Because.
In addition, in the case of a polyether skeleton, compared with the case of a polyester skeleton, a polycaprolactone skeleton, and a polycarbonate skeleton, while maintaining the adhesion of the base layer to the nails effectively, This is because the curability can be improved.

  Here, the kind of the polyether skeleton polyol for obtaining the polyether skeleton urethane methacrylate oligomer is not particularly limited, but it is easily available industrially and is relatively inexpensive. A skeleton diol compound is preferred.

Moreover, as a kind of organic polyisocyanate compound for obtaining a polyether skeleton urethane methacrylate oligomer, a non-yellowing type such as isophorone diisocyanate, hexamethylene diisocyanate, 4,4-dicyclohexylmethane diisocyanate, trimethylhexamethylene diisocyanate is preferable. .
Moreover, as hydroxy methacrylate for obtaining a polyether skeleton urethane methacrylate oligomer, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, caprolactone-modified 2-hydroxyethyl methacrylate and the like are preferable.
However, it is not always necessary to use these polyether skeleton urethane methacrylate oligomers alone, and other urethane (meth) acrylate oligomers, for example, polyester skeleton urethane (meth) acrylate oligomers, as long as the effects of the present invention can be obtained. It is also preferable to use a polycaprolactone skeleton urethane (meth) acrylate oligomer, a polycarbonate skeleton urethane (meth) acrylate oligomer, or the like in combination.

(2) Weight average molecular weight Moreover, it is preferable that the weight average molecular weight of the polyether frame | skeleton urethane methacrylate oligomer which is (A) component is 10,000-50,000.
The reason for this is that by setting the weight average molecular weight of the component (A) to a value within this range, the shrinkage rate when the photocurable gel nail base agent is photocured is reduced, and the adhesion of the base layer to the nail is reduced. This is because the peelability can be further improved while maintaining the properties.
That is, when the weight average molecular weight of the component (A) is less than 10,000, the curing rate of the photocurable gel nail base agent is excessively increased, and the adhesion of the base layer to the nail becomes insufficient. This is because the base layer may be easily peeled off excessively. On the other hand, when the weight average molecular weight of the component (A) exceeds 50,000, the curing rate of the photocurable gel nail primer is excessively decreased, the curing time becomes long, or the primer layer is required. This is because it may be difficult to obtain durability.
Therefore, the weight average molecular weight of the polyether skeleton urethane methacrylate oligomer as the component (A) is more preferably set to a value within the range of 15,000 to 35,000, and within the range of 20,000 to 30,000. More preferably, it is a value.

(3) Blending amount The blending amount of the polyether skeleton urethane methacrylate oligomer as the component (A) is the total amount of the base material for photocurable gel nail containing the components (A) to (F) (100% by weight). ) To a value within the range of 30 to 70% by weight.
This is because the adhesion to the nail can be improved while effectively maintaining the curing rate.
That is, when the blending amount of the component (A) is less than 30% by weight, the curing rate of the photocurable gel nail primer is excessively decreased, the curing time is prolonged, and durability required for the underlying layer This is because it may be difficult to obtain sex. On the other hand, when the blending amount of the component (A) exceeds 70% by weight, the curing rate of the photocurable gel nail base agent is excessively increased and the adhesion of the base layer to the nail becomes insufficient. This is because the base layer may be easily peeled off excessively.
Therefore, the blending amount of the polyether skeleton urethane methacrylate oligomer as the component (A) is more preferably set to a value in the range of 35 to 65% by weight with respect to the total amount of the base material for the photocurable gel nail. Preferably, the value is in the range of 40 to 60% by weight.

2. (B) Component: (Meth) acrylate Monomer (1) Type The photocurable gel nail primer of the present invention is characterized by containing an alicyclic (meth) acrylate monomer as the component (B).
The reason for this is that the reactivity of the photocurable gel nail primer, which is suppressed in a predetermined range by the component (A), is increased in the predetermined range by the component (B) having excellent reactivity, and the component (A) This is because the peelability can be improved while maintaining excellent adhesion to the nail of the underlying layer derived from the above.
That is, the alicyclic (meth) acrylate and monomer as the component (B) are included as a reactive diluent for adjusting the viscosity of the photocurable gel nail primer and the peelability of the primer layer.
More specifically, if it is an alicyclic (meth) acrylate monomer, it has an alicyclic structure in the molecule, so there is little shrinkage due to photocuring, and thereby the curability of the base material for photocurable gel nail. This is because the adhesion of the base layer to the nail can be improved while maintaining the above effectively.

In the present invention, the alicyclic (meth) acrylate includes a structural site derived from (meth) acrylic acid and a structural site derived from alcohol, and the structural site derived from alcohol is unsubstituted or substituted. It has a structure containing at least one alicyclic hydrocarbon group.
The alicyclic hydrocarbon group may be a structural site derived from alcohol itself, or may be bonded to a structural site derived from alcohol via a linking group.
In the present invention, “(meth) acrylate” means methacrylate or acrylate, and the same applies to the following.

The alicyclic hydrocarbon group is not particularly limited as long as it contains a cyclic non-aromatic hydrocarbon group, and is a monocyclic hydrocarbon group, bicyclic hydrocarbon group, tricyclic or more polycyclic hydrocarbon group. A cyclic hydrocarbon group is mentioned.
For example, a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a cycloalkenyl group, a bicyclohexyl group, a norbornyl group, an isobornyl group, a dicyclopentanyl group, a dicyclopentenyl group, an adamantyl group, a decahydronaphthalenyl group, perl A hydrofluorenyl group, a tricyclo [5.2.1.0 ^2,6 ] decanyl group, a bicyclo [4.3.0] nonane, and the like can be given.

  In addition, as a linking group that connects the alicyclic hydrocarbon group and the structural portion derived from alcohol, an alkyl group, alkenyl group, alkylene group, aralkyl group, alkoxy group, mono- or oligo group having 1 to 20 carbon atoms can be used. Preferred examples include an ethylene glycol group and a mono- or oligopropylene glycol group.

Moreover, the specific example of an alicyclic (meth) acrylate is shown below.
That is, cyclopropyl (meth) acrylate, cyclobutyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl (meth) acrylate, cyclononyl (meth) acrylate, cyclodecyl (meth) ) Cycloalkyl (meth) acrylate having 3 to 10 carbon atoms such as acrylate, isobornyl (meth) acrylate, norbornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, di Cyclopentenyloxyethyl (meth) acrylate, dicyclopentadiene (meth) acrylate, dicyclopentenyl (meth) acrylate, tricyclodecanyl (meth) Acrylate, tricyclodecanyl oxyethyl (meth) acrylate.

Among these, it is preferable to use isobornyl methacrylate.
The reason for this is that if isobornyl methacrylate is used, not only can the curing rate when photocuring the base material for photocurable gel nail be photocured be increased, but also the nail of the underlying layer derived from the component (A) This is because the peelability can be further improved while maintaining the excellent adhesion to the film.
Moreover, it is because it contributes also to making PII value in the base material for photocurable gel nail into a smaller value.
In other words, isobornyl methacrylate can not only improve the curability of the photocurable gel nail base material and the adhesion of the base layer to the nails, but is also excellent as a reactive diluent, and easily This is because the viscosity of the photocurable gel nail primer can be adjusted, and the handling property can be improved.

(2) Compounding quantity Moreover, the compounding quantity of the alicyclic (meth) acrylate monomer which is (B) component is 20-60 weight with respect to 100 weight part of polyether skeleton urethane methacrylate oligomer which is (A) component. The value is within the range of the part.
The reason for this is that by setting the blending amount of the component (B) to a value within such a range, the curing rate of the photocurable gel nail base material is effectively improved, and the peelability of the base layer to the nail is improved. However, the excellent adhesion derived from the component (A) can be more effectively maintained.
Moreover, it is because the irritation with respect to a nail | claw and its surrounding skin can be suppressed.
That is, when the blending amount of the component (B) is less than 20 parts by weight, the curing rate of the photocurable gel nail primer is excessively increased, and it becomes difficult to control the curability. This is because the maintenance of excellent adhesion to the nail of the underlayer derived from the above becomes insufficient, and the underlayer may become excessively easy to peel off. On the other hand, when the blending amount of the component (B) exceeds 60 parts by weight, the curing rate of the photocurable gel nail base agent is excessively decreased, and the curing time becomes long or the base layer is required. This is because it may be difficult to obtain durability.
Therefore, the blending amount of the alicyclic (meth) acrylate monomer as the component (B) is a value within the range of 22 to 50 parts by weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). It is more preferable to set the value within the range of 25 to 45 parts by weight.

Next, referring to FIG. 1, blending of an alicyclic (meth) acrylate monomer as component (B) with respect to adhesion to the nail of the underlayer formed by photocuring the base material for photocurable gel nail and peelability The influence of the amount will be described.
That is, in FIG. 1, the horizontal axis represents the blending amount (parts by weight) of the alicyclic (meth) acrylate monomer as the component (B) with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). The characteristic curve A showing the adhesion (evaluation point) of the underlayer to the nail is shown on the left vertical axis, and the characteristic taking the peelability (evaluation point) of the underlayer to the nail is shown on the right vertical axis. Curve B is shown.
The evaluation points of adhesion and peelability are obtained by evaluating adhesion (warm water resistance) and peelability described below, and quantifying the obtained results according to the following criteria.
The details of the photocurable gel nail primer, the composition of the photocurable gel nail composition, and the like are the same as in Examples 1, 4 to 5 and Comparative Examples 3 to 4.

(Adhesion)
Hands with the base layer and gel nail layer formed on the nails are usually washed with warm water of about 25 ° C without using soap, and after the washing is completed, the hands are wiped off with a towel-like material on a day. This was performed 30 times, and the appearance change after this was continued for 3 days was quantified according to the following criteria.
4: No change in appearance was observed even after 3 days.
3: Within 3 days, slight peeling was confirmed between the nail and the base layer.
Within 2: 1 day, some peeling was confirmed between the nail and the base layer, and whitening was confirmed in part of the appearance.
Within 1: 1 day, remarkable peeling was confirmed between the nail and the base layer, and whitening was confirmed over the entire appearance.

(Peelability)
A cloth containing acetone was wrapped around the nail on which the base layer and the gel nail layer were formed and lightly rubbed, and the degree of peeling at that time was quantified according to the following criteria.
4: The laminate of the release layer and the gel nail layer peeled from the nail in less than 15 minutes.
3: In less than 15 to 30 minutes, the laminate of the release layer and the gel nail layer peeled from the nail.
2: The laminate of the peeling layer and the gel nail layer peeled from the nail in less than 30 to 45 minutes.
At 1:45 minutes, the laminate of the release layer and the gel nail layer did not peel from the nail.

First, it is understood from the characteristic curve A that there is an optimum range for the amount of component (B) when improving adhesion.
That is, as the blending amount of component (B) increases, it is understood that the adhesiveness once increases and then decreases.
More specifically, if the blending amount of the component (B) is a value within the range of 20 to 60 parts by weight, the adhesion evaluation point can be stably set to a value of 3 or more, but otherwise In this numerical range, it is understood that it is difficult to stably maintain the adhesion evaluation point at a value of 3 or more, and it is difficult to maintain excellent adhesion.

Further, the characteristic curve B is the same as the characteristic curve A, and if the blending amount of the component (B) is in the range of 20 to 60 parts by weight, the evaluation point of peelability is stably set to a value of 3 or more. On the other hand, in other numerical ranges, it is understood that it becomes difficult to stably maintain the peelability evaluation point at a value of 3 or more.
Therefore, the blending amount of the component (B) is set to a value within the range of 20 to 60 parts by weight with respect to 100 parts by weight of the component (A), so that the base layer derived from the component (A) is excellent for nails. It is understood that the peelability can be effectively improved while maintaining the adhesion.

3. Component (C): Acrylamide Monomer (1) Type The photocurable gel nail primer of the present invention is characterized by containing an acrylamide monomer that is liquid at 25 ° C. as component (C).
The reason for this is that the reactivity of the photocurable gel nail primer, which is suppressed in a predetermined range by the component (A), is increased in the predetermined range by the component (C) having excellent reactivity, and the component (A) This is because the peelability can be improved while maintaining excellent adhesion to the nail of the underlying layer derived from the above.
That is, since the acrylamide monomer that is liquid at 25 ° C. as the component (C) is liquid at 25 ° C., the viscosity of the base material for the photocurable gel nail can be effectively adjusted, and light Since it contributes to the improvement of flexibility in the underlayer after curing, it is included as a suitable reactive diluent.
More specifically, an acrylamide-based monomer that is liquid at 25 ° C. has nitrogen atoms in the molecule, so that while maintaining the curing rate of the photocurable gel nail base material effectively, This is because not only the adhesion of the underlayer can be improved, but also a predetermined flexibility can be imparted to the underlayer.

  The types of acrylamide monomers that are liquid at 25 ° C. include isobutoxymethylacrylamide, hydroxyethylacrylamide, N, N-dimethylacrylamide, t-octylacrylamide, N, N-diethylacrylamide, and N, N-butoxy. Examples include methyl acrylamide and N, N-dimethylaminopropyl acrylamide.

Among these, it is preferable to use hydroxyethyl acrylamide.
The reason for this is that if hydroxyethyl acrylamide can effectively improve the flexibility of the underlayer, it can be peeled off while maintaining excellent adhesion to the nail of the underlayer derived from the component (A). This is because the properties can be further improved.
That is, if it is hydroxyethyl acrylamide, while being able to maintain the sclerosis | hardenability of the base agent for photocurable gel nails effectively, the flexibility of a base layer can be improved, and it is liquid at 25 degreeC. This is because it is possible to facilitate the viscosity adjustment of the photocurable gel nail primer and to improve the handleability.

(2) Blending amount The blending amount of the acrylamide monomer that is liquid at 25 ° C. as the component (C) is 5 to 20 with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). The value is within the range of parts by weight.
The reason for this is that by setting the blending amount of the component (C) to a value within such a range, the curing rate of the photocurable gel nail base material is effectively improved and the peelability of the base layer to the nail is improved. However, it is because the excellent adhesion derived from the component (A) can be more effectively maintained by imparting flexibility to the base layer.
That is, when the blending amount of the component (C) is less than 5 parts by weight, the curing rate of the photocurable gel nail base agent is excessively increased, and it becomes difficult to control the curability. This is because the maintenance of excellent adhesion to the nail of the underlayer derived from the above becomes insufficient, and the underlayer may become excessively easy to peel off. On the other hand, when the blending amount of component (C) exceeds 20 parts by weight, the curing rate of the photocurable gel nail base agent is excessively decreased, the curing time is excessively long, or the base layer is required. This is because it may be difficult to obtain durability.
Therefore, the blending amount of the acrylamide monomer that is liquid at 25 ° C. as the component (C) is in the range of 8 to 18 parts by weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). More preferably, the value is more preferably in the range of 10 to 15 parts by weight.

Next, referring to FIG. 2, the acrylamide monomer that is liquid at 25 ° C., which is component (C), is a component (C) for the adhesiveness and peelability of the base layer formed by photocuring the photocurable gel nail base agent. The effect of the amount will be described.
That is, in FIG. 2, the horizontal axis represents the blending amount (parts by weight) of the acrylamide monomer that is liquid at 25 ° C. as the component (C) with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). ), And the left vertical axis shows the characteristic curve A that shows the adhesion (evaluation point) of the foundation layer to the nail, and the right vertical axis shows the peelability (evaluation point) of the foundation layer to the nail. A characteristic curve B is shown.
The criteria for evaluation points of adhesion and peelability are the same as those in the case of the characteristic curve shown in FIG. 1, and the composition of the photocurable gel nail primer, the photocurable gel nail composition, etc. Details are in accordance with Examples 1, 6-7 and Comparative Examples 5-6.

First, it is understood from the characteristic curve A that there is an optimum range for the amount of component (C) when improving the adhesion.
That is, it is understood that as the blending amount of the component (C) increases, the adhesiveness once increases and then decreases.
More specifically, if the blending amount of component (C) is in the range of 5 to 20 parts by weight, the adhesion evaluation point can be stably set to a value of 3 or more, while other numerical values are used. In the range, it is understood that it is difficult to stably maintain the adhesion evaluation point at a value of 3 or more, and it is difficult to maintain excellent adhesion.

Also, the characteristic curve B is the same as the characteristic curve A, and if the blending amount of the component (C) is a value within the range of 5 to 20 parts by weight, the peelability evaluation point is stably 3 or more. On the other hand, it can be understood that, in other numerical ranges, it becomes difficult to stably maintain the peelability evaluation score at a value of 3 or more.
Therefore, the blending amount of the component (C) is set to a value within the range of 5 to 20 parts by weight with respect to 100 parts by weight of the component (A), so that the base layer derived from the component (A) is excellent for nails. It is understood that the peelability can be effectively improved while maintaining the adhesion.

4). Component (D): Bifunctional (meth) acrylate monomer (1) type The photocurable gel nail primer of the present invention comprises a bifunctional (meth) acrylate monomer having EO in the molecule as component (D). It is characterized by including.
The reason for this is that the reactivity of the photocurable gel nail primer, which is suppressed in a predetermined range by the component (A), is increased in a predetermined range by the component (D) which is a cross-linking agent excellent in reactivity. This is because the peelability can be improved while maintaining excellent adhesion to the nail of the base layer derived from the component (A).
More specifically, in the case of a bifunctional (meth) acrylate monomer having EO in the molecule, by having EO in the molecule, the polarity of the molecule is increased, and the curing rate of the photocurable gel nail base material is increased. This is because the adhesion of the base layer to the nail can be improved while maintaining the above effectively.

  Here, as a kind of the bifunctional (meth) acrylate monomer having EO in the molecule, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol (# 200) diester Acrylate, polyethylene glycol (# 400) diacrylate, polyethylene glycol (# 600) diacrylate, neopentyl glycol diacrylate, neopentyl glycol diacrylate hydroxypivalate, 1,4-butanediol diacrylate, 1,6-hexanediol Diacrylate, 1,9-nonanediol diacrylate, propylene glycol diacrylate, dipropylene glycol diacrylate, tri B propylene glycol diacrylate, polypropylene glycol diacrylate, bisphenol A-EO (ethylene oxide) adduct diacrylate, dimethylol tricyclodecane diacrylate, polytetramethylene glycol diacrylate.

Among these, it is preferable to use bisphenol A-EO adduct diacrylate.
The reason for this is that if it is a bisphenol A-EO adduct diacrylate, the peelability can be further improved while maintaining excellent adhesion to the nail of the underlayer derived from the component (A).
In particular, bisphenol A-EO adduct diacrylate having an EO repeat number n = 4 improves the flexibility of the underlayer, thereby providing excellent adhesion to the nail of the underlayer derived from the component (A). It is more preferable because the peelability can be further improved while maintaining effectively.
In the present invention, bisphenol A-EO adduct diacrylate is a compound obtained by addition reaction of ethylene oxide to a bifunctional acrylate monomer obtained by reaction of bisphenol A diglycidyl ether and acrylic acid. Show.

(2) Blending amount The blending amount of the bifunctional (meth) acrylate monomer having EO in the molecule as the component (D) is 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). The value is in the range of 20 to 40 parts by weight.
The reason for this is that by setting the blending amount of the component (D) to a value within this range, the crosslink density of the photocurable gel nail base agent is effectively improved, and the peelability of the base layer to the nail is improved. However, it is because the excellent adhesion derived from the component (A) can be more effectively maintained by imparting flexibility to the base layer.
That is, when the blending amount of the component (D) is less than 20 parts by weight, the curing rate of the photocurable gel nail base agent is excessively decreased, the curing time is excessively long, or the base layer is required. This is because it may be difficult to obtain durability. On the other hand, when the blending amount of the component (D) exceeds 40 parts by weight, the curing rate of the photocurable gel nail primer is excessively increased, making it difficult to control the curability, or (A) This is because the maintenance of excellent adhesion to the nail of the base layer derived from the components becomes insufficient, and the base layer may be easily peeled off excessively.
Therefore, the blending amount of the bifunctional acrylate monomer having EO in the molecule as the component (D) is within the range of 25 to 38 parts by weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). More preferably, the value is more preferably in the range of 28 to 35 parts by weight.

Next, referring to FIG. 3, a bifunctional acrylate monomer having EO in the molecule as component (D) for adhesion to the nail and peelability of the undercoat layer obtained by photocuring the photocurable gel nail primer. The effect of the blending amount will be described.
That is, in FIG. 3, the blended amount of the bifunctional acrylate monomer having EO in the molecule as the component (D) with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A) is shown on the horizontal axis. The left vertical axis shows a characteristic curve A that shows the adhesion (evaluation point) of the underlayer to the nail, and the right vertical axis shows the characteristic curve B that takes the peelability (evaluation point) of the underlayer to the nail. Is shown.
The criteria for the evaluation points of adhesion and peelability are the same as in the case of the characteristic curve shown in FIG. 1, and details such as the composition of the photocurable gel nail primer and the composition of the photocurable gel nail composition, etc. Are in accordance with Examples 1, 8-9 and Comparative Examples 7-8.

First, it is understood from the characteristic curve A that there is an optimum range for the blending amount of the component (D) when improving the adhesion.
That is, as the blending amount of component (D) increases, it is understood that the adhesiveness once increases and then decreases.
More specifically, if the blending amount of the component (D) is a value within the range of 20 to 40 parts by weight, the adhesion evaluation point can be stably set to a value of 3 or more, otherwise In this numerical range, it is understood that it is difficult to stably maintain the adhesion evaluation point at a value of 3 or more, and it is difficult to maintain excellent adhesion.

Further, the characteristic curve B is the same as the characteristic curve A, and if the blending amount of the component (D) is a value within the range of 20 to 40 parts by weight, the evaluation score of peelability is stably 3 or more. On the other hand, it can be understood that, in other numerical ranges, it becomes difficult to stably maintain the peelability evaluation score at a value of 3 or more.
Therefore, the blending amount of the component (D) is set to a value within the range of 20 to 40 parts by weight with respect to 100 parts by weight of the component (A), so that the base layer derived from the component (A) is excellent for nails. It is understood that the peelability can be effectively improved while maintaining the adhesion.

5. Component (E): Trifunctional or higher polyfunctional (meth) acrylate monomer Further, the photocurable gel nail primer of the present invention substantially comprises a trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E). Is not included.
More specifically, the trifunctional or higher polyfunctional (meth) acrylate monomer is 0 part by weight , or 0 to 1 part by weight (100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A)). However, 0 part by weight is not included.)
The reason for this is that when the component (E) is contained in a predetermined range or more, the excellent adhesion of the base layer to the nail derived from the component (A) is remarkably reduced, and the base layer is easily peeled off from the nail. It is.
That is, when the amount of the component (E) exceeds 1 part by weight, the curing rate of the photocurable gel nail base agent is excessively high, and the shrinkage rate at that time is excessively high. This is because not only the excellent adhesion of the underlayer to the nail derived from the component A) is remarkably lowered, but also the formed underlayer is likely to crack.
Therefore, in principle, the blending amount of the trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E) is 0 weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). However, even when a small amount is used for adjusting the curing speed and peelability, it is more preferable to set the value within the range of 0.1 to 0.8 parts by weight, and 0.3 to 0. More preferably, the value is within the range of 5 parts by weight.

Here, the trifunctional or higher polyfunctional (meth) acrylate monomer is, for example, pentaerythritol triacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipenta Literally means a trifunctional or higher polyfunctional (meth) acrylate monomer such as erythritol hexaacrylate.

Next, referring to FIG. 4, a polyfunctional (meth) acrylate having three or more functionalities, which is a component (E) for adhesion to the nail and peelability of the undercoat layer obtained by photocuring the photocurable gel nail primer. The influence of the monomer content will be described.
That is, in FIG. 4, the blending amount of the trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E) with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A) is shown on the horizontal axis. The left vertical axis shows a characteristic curve A that shows the adhesion (evaluation point) of the underlayer to the nail, and the right vertical axis shows the characteristic curve B that takes the peelability (evaluation point) of the underlayer to the nail. Is shown.
The criteria for the evaluation points of adhesion and peelability are the same as in the case of the characteristic curve shown in FIG. 1, and details such as the composition of the photocurable gel nail primer and the composition of the photocurable gel nail composition, etc. Corresponds to Examples 1, 10 to 11 and Comparative Examples 9 to 11.

First, it is understood from the characteristic curve A that the adhesiveness decreases as the blending amount of the component (E) increases.
More specifically, if the blending amount of component (E) is a value of 1 part by weight or less, the adhesion evaluation point can be 3 or more, while the value exceeds 1 part by weight. It is understood that it becomes difficult to maintain the adhesion evaluation score at a value of 3 or more, and it becomes difficult to maintain excellent adhesion.

Further, the characteristic curve B is almost the same as the characteristic curve A, and if the blending amount of the component (E) is a value of 1 part by weight or less, the peelability evaluation score may be at least 2 or more. On the other hand, when the value exceeds 1 part by weight, it is understood that it becomes difficult to set the evaluation point of peelability to a value of 2 or more.
Therefore, the blending amount of the component (E) is 0 part by weight or 0 to 1 part by weight (however, 0 part by weight is not included) with respect to 100 parts by weight of the component (A). It is understood that the peelability can be effectively improved while maintaining excellent adhesion to the nail of the base layer derived from the components.

6). Component (F): Photopolymerization Initiator (1) Type The photocurable gel nail primer of the present invention is characterized by containing a photopolymerization initiator as the component (F).
Such a photopolymerization initiator is not particularly limited as long as it generates a radical by ultraviolet rays, and the radical causes a polymerization reaction of a urethane acrylate oligomer or a methacrylate monomer.
Specific examples of such photopolymerization initiators include benzophenone compounds such as benzophenone, chlorobenzophenone, hydroxybenzophenone, 4,4′-dimethylaminobenzophenone, 4,4′-diethylaminobenzophenone; 2,2-dimethoxy-1 Benzyl dimethyl ketal compounds such as 2-diphenylethane-1-one; oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone], 1-hydroxycyclohexyl phenyl ketone, Α-hydroxy ketone compounds such as 2-hydroxy-2-methyl-1-phenyl-propan-1-one; 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one 2-benzyl-2-dimethylamino-1- (4-morpholinofe Α-aminoketone compounds such as dil) -butanone-1; acylphosphine oxide compounds such as diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide; 1- [4- (4-benzoylphenylsulfanyl); Phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one and the like ketosulfone compounds; bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6- Metallocene compounds such as difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium; 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone, 2- (3-dimethylamino- 2-hydroxypropoxy) 3,4-dimethyl-9H-thioxanthone-9 And thioxanthone compounds such as on-mesochloride.

  Among the photopolymerization initiators described above, acylphosphine oxide compounds having a phenyl group, α-hydroxyketone compounds, and benzophenone compounds generate radicals by ultraviolet rays, and these radicals are converted into photopolymerization oligomers and photopolymerization. By efficiently reacting with the monomer, the curing reaction is accelerated.

In addition, a photopolymerization initiator of a type that generates radicals by hydrogen abstraction, such as a thioxanthone compound, is a more preferable embodiment because the curing reaction is accelerated by combining with a hydrogen donor.
Examples of such a hydrogen donor include mercapto compounds and amine compounds, and among them, amine compounds are preferable.
As suitable amine compounds, triethylamine, methyldiethanolamine, triethanolamine, diethylaminoethyl acrylate, p-dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, N-dimethylbenzylamine 4,4′-bis (diethylamino) benzophenone, p-dimethylaminobenzoic acid ethyl ester, pentyl 4-dimethylaminobenzoate, and the like.

Moreover, it is preferable to mix and use at least two kinds of photopolymerization initiators.
In particular, since the curing speed and weather resistance are appropriate and the durability as a cured coating film can be effectively adjusted, the α-hydroxyketone compound or the benzophenone compound is added to the acylphosphine oxide compound. It is preferable to use a mixture of any one of the compounds.
In addition, when it is configured as a colorless (clear) photocurable gel nail composition that does not contain pigments and does not use colored pigments, photopolymerization is started to avoid the effects of coloring of the photocured coating film. It is preferable to use only an α-hydroxyketone compound as the agent.

(2) Compounding quantity Moreover, the compounding quantity of the photoinitiator which is (F) component is in the range of 5-20 weight part with respect to 100 weight part of polyether skeleton urethane methacrylate oligomer which is (A) component. It is set as the value of.
The reason for this is that when the blending amount of the component (F) is less than 5 weights, the curing rate of the photocurable gel nail base agent is excessively decreased, the curing time is excessively long, or the base layer is required. This is because it may be difficult to obtain durability. On the other hand, when the blending amount of the component (F) exceeds 20 parts by weight, the curing rate of the photocurable gel nail primer is excessively increased, and it becomes difficult to control the curability. This is because the maintenance of excellent adhesion to the nail of the base layer derived from the components becomes insufficient, and the base layer may be easily peeled off excessively.
Therefore, the blending amount of the photopolymerization initiator as the component (F) is set to a value within the range of 7 to 18 parts by weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). Is more preferable, and a value in the range of 9 to 16 parts by weight is even more preferable.

7). (G) Component: Colorant Further, in constituting the photocurable gel nail primer, a colorant can also be included as the (G) component.
Examples of the colorant include inorganic color pigments, organic color pigments, organic dyes, pearl pigments, lame colorants, and the like.
More specifically, preferred pigments include condensed azo pigments, diketopyrrolopyrrole pigments, perylene pigments, cnacridon pigments, isoindolinone pigments, dioxazine pigments, phthalocyanine pigments, organic coloring pigments, and the like. Examples thereof include inorganic coloring pigments such as titanium pigments and carbon black pigments.
Examples of the lame colorant include a polyethylene terephthalate film which is a synthetic resin film having fine grooves, a deposited metal and a binder resin such as an epoxy resin, which are finely cut.
The blending amount of the colorant is determined within a range that does not inhibit the photocuring speed of the base material for photocurable gel nail and does not decrease the object of the present invention. Usually, the polyether skeleton urethane which is the component (A) It is used in the range of 0.1 to 35 parts by weight with respect to 100 parts by weight of the methacrylate oligomer.

8). (H) Component: Additive In addition, an additive can also be included as the (H) component in constituting the photocurable gel nail primer.
For example, it is preferable to blend a predetermined amount of a whitening agent (a blueing agent) in order to adjust the color of the underlayer.
Specifically, one kind or a mixture of two or more kinds of ultramarine blue, cobalt blue, cobalt phosphate phosphate, quinacridone pigment, etc. is added to 100 parts by weight of the polyether skeleton urethane methacrylate as the component (A). It is preferable to blend at a value within the range of 0.001 to 2 parts by weight.
In addition, for the purpose of adjusting the viscosity and coating suitability of the photocurable gel nail base material, antifoaming agents, leveling agents, pigment wetting agents, dispersants, flow regulators, thermal polymerization inhibitors, oxidation polymerization inhibitors, etc. It is also preferable to blend at least one with a value in the range of 0.001 to 5 parts by weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate as the component (A).

[Second Embodiment]
The second embodiment of the present invention is a gel nail method using a photocurable gel nail primer, and includes the following steps (1) to (5). .
(1) Step of preparing a photocurable gel nail primer containing the following components (A) to (F) (A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate Monomer 20-60 parts by weight (C) Acrylamide monomer which is liquid at 25 ° C. 5-20 parts by weight (D) Bifunctional (meth) acrylate monomer having ethylene oxide in the molecule
20 to 40 parts by weight (E) Trifunctional or higher polyfunctional (meth) acrylate monomer
0 parts by weight , or 0 to 1 part by weight
(However, 0 parts by weight are not included.)
(F) Photopolymerization initiator 5 to 20 parts by weight (2) Step of applying photocurable gel nail primer to nails (3) Photocuring the applied photocurable gel nail primer, Step for forming underlayer (4) Step for applying photocurable gel nail composition to underlayer (5) Step for photocuring applied photocurable gel nail composition to form gel nail layer That is, according to the gel nail method of the present invention, since a predetermined photocurable gel nail base material is used, a base layer excellent in the balance between adhesion to the nail and peelability can be stably and in a short time. Can be formed.
Therefore, the gel nail layer laminated above the base layer can be effectively adhered to the nail through the base layer, and can be easily peeled together with the base layer at the time of peeling. .
Hereinafter, the gel nail method of the second embodiment of the present invention will be specifically described.

1. Formation of underlayer (1) Preparatory step: Step (1)
As shown to Fig.5 (a), the nail | claw 10 of self-finger 10 'as a base material which forms a gel nail layer is prepared.
At that time, when the surface of the fingernail is dirty, it is preferable to degrease alcohol in advance.
The base material for forming such a coating layer is usually a self nail, but it may be a base material made of synthetic plastic such as ABS or acrylic sheet.
That is, by using a base material made of a synthetic plastic such as an ABS sheet and using the photo-curable gel nail composition of the present invention, a gel nail layer can be formed to constitute an artificial nail or false nail. It is.

Moreover, the base material for photocurable gel nail demonstrated in 1st Embodiment is prepared.
That is, such a photocurable gel nail primer can be prepared by a known mixing method.
For example, for the compounding ingredients, a base material for photo-curing gel nail is prepared by uniformly mixing using various mixing devices such as a propeller mixer, a planetary mixer, a ball mill, a jet mill, a three-roller, and a kneader. Can do.
The details of the photo-curing gel nail base material have been described in the first embodiment, and are therefore omitted.

(2) Application process: Process (2)
Next, as shown in FIG. 5 (b), a photocurable gel nail primer 12 ′ is applied onto the base material (nail) 10.
Here, the method for applying the photocurable gel nail composition to the base material (nail) is not particularly limited, and for example, a brush, a brush, a spatula, a roller, a dropper, or the like can be used.
Moreover, although the thickness of this application layer is based also on a design, it is usually preferable to set it as the value within the range of 10-5,000 micrometers, and it is more preferable to set it as the value within the range of 30-3,000 micrometers, More preferably, the value is in the range of 50 to 2,000 μm.

(3) Photocuring step: Step (3)
Next, as shown in FIG. 5 (c), the applied photocurable gel nail primer 12 'is irradiated with a predetermined amount of ultraviolet rays 14a from the irradiation device 14 to be photocured, and the predetermined lowering is applied. The formation 12 is formed on the base material (nail) 10.
Moreover, as an irradiation condition of the ultraviolet rays when the coating layer of the photocurable gel nail base material is photocured to form a base layer, a value within the range of 250 to 600 mJ / cm ² is preferable. it is more preferably a value within the range of 450 mJ / cm ^2, still more preferably a value within the range of 350~400mJ / cm ^2.
In addition, it is preferable to use ultraviolet LED as an irradiation apparatus, and it is preferable to set it as the value within the range of 340-420 nm as a wavelength range of an ultraviolet-ray.

2. Formation of Gel Nail Layer (1) Preparatory Step Next, a photocurable gel nail composition to be applied on the underlayer is prepared.
The photocurable gel nail composition is not particularly limited, and a conventionally known photocurable gel nail composition can be used.

Moreover, it is preferable that a photocurable gel nail composition contains the following (A) component, (B) component, (D) component, (E ') component, and (F) component.
(A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate monomer 20-60 parts by weight (D) Bifunctional (meth) acrylate monomer having ethylene oxide in the molecule
20-40 parts by weight (E ′) Trifunctional or higher polyfunctional (meth) acrylate monomer 5-20 parts by weight (F) Photopolymerization initiator 5-20 parts by weight

This is because the adhesion of the gel nail layer to the underlayer can be further improved.
That is, if it is such a photocurable gel nail composition, (A) component, (B) component, (D) component, and (F) component of the base agent for photocurable gel nail which forms a base layer. This is because, since the composition is common, the affinity between the base layer and the gel nail layer can be improved, and the adhesion can be effectively improved.
Therefore, the types and blending amounts of the component (A), the component (B), the component (D), and the component (F) are the same as those of the base material for the photocurable gel nail described in the first embodiment. be able to.

In addition, the photocurable gel nail composition contains a trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E ′), based on 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). , Preferably 5 to 20 parts by weight.
This is because the photocurable gel nail base preparation described in the first embodiment has a polyfunctionality of 3 or more functionalities as the component (E) from the viewpoint of preventing the lowering of the adhesion of the base layer to the nails. It was necessary to be substantially free of (meth) acrylate monomers.
In this regard, the gel nail layer obtained by photocuring the photocurable gel nail composition is not directly formed on the nail, but is formed on the base layer, and therefore, without considering the decrease in adhesion to the nail. This is because a trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E ′) can be blended.
That is, when the blending amount of the component (E ′) is less than 5 parts by weight, the gel nail layer has insufficient hardness, and sufficient durability may not be obtained. On the other hand, when the blending amount of the component (E ′) exceeds 20 parts by weight, the shrinkage rate when photocuring the photocurable gel nail composition is excessively increased, and cracks are likely to occur. This is because the gel nail layer may be easily peeled off from the underlayer.
Therefore, the blending amount of the trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E ′) is 6 to 16 parts by weight with respect to 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). More preferably, the value is within the range of 8 to 14 parts by weight.
In addition, about the kind of (E ') component, it is the same content as the (E) component in the base agent for photocurable gel nail which is 1st Embodiment.
On the other hand, the photocurable gel nail base material does not substantially contain the component (E), whereas the photocurable gel nail composition preferably contains a predetermined amount. In order to solve the problem, in the photocurable gel nail composition, a trifunctional or higher polyfunctional (meth) acrylate monomer is described as “component (E ′)”.

The trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E ′) is preferably dipentaerythritol hexaacrylate.
The reason for this is that if dipentaerythritol hexaacrylate is used, the gel nail layer hardness can be improved while stably maintaining the adhesion of the gel nail layer to the underlayer, and thus the durability of the gel nail layer can be improved. This is because it can be improved.
That is, with dipentaerythritol hexaacrylate, it is possible not only to further improve the curing speed and durability while maintaining the adhesion of the gel nail layer to the underlayer effectively, but also to provide glossiness, decorativeness and This is because a gel nail layer having excellent visual properties can be obtained.

Moreover, it is preferable that a photocurable gel nail composition contains the coloring agent which is (G) component.
This is because the gel nail layer formed by photocuring the photocurable gel nail composition is a layer formed for the purpose of imparting decorativeness to the nails.
In addition, about the kind and compounding quantity of the coloring agent which are (G) components, it can be made to be the same as that of the base agent for photocurable gel nail demonstrated in 1st Embodiment.

Further, the acrylamide monomer that is liquid at 25 ° C. as the component (C) may be blended in the same manner as the base material for the photocurable gel nail described in the first embodiment, but the photocurable gel is used. In a nail composition, it is preferable not to mix | blend.
The reason for this is that when an acrylamide monomer that is liquid at 25 ° C., which is component (C), is added to the photocurable gel nail composition, the flexibility of the gel nail layer increases, and the underlying layer as the lower layer This is because the adhesion between the underlayer and the gel nail layer is likely to delaminate.
Therefore, in the photocurable gel nail composition, the blending amount of the acrylamide monomer that is liquid at 25 ° C. as the component (C) is 100 parts by weight of the polyether skeleton urethane methacrylate oligomer as the component (A). It is preferably 0 parts by weight, and even if it is blended, it is preferably set to a value within the range of 0 to 4 parts by weight (however, 0 parts by weight is not included). More preferably, the value is within the range of parts by weight.

(2) Application process: Process (4)
Next, as shown in FIG. 5 (d), a photocurable gel nail composition 16 ′ is applied on the underlayer 12.
In addition, this application | coating process can be performed similarly to the application | coating process of the base agent for photocurable gel nail which is a process (2).

(3) Photocuring step: Step (5)
Next, as shown in FIG. 5 (e), the applied photocurable gel nail composition 16 ′ is photocured by irradiating a predetermined amount of ultraviolet rays 14 a from the irradiation device 14, thereby forming the gel nail layer 16. It is formed on the underlayer 12.
In addition, this photocuring process can be performed similarly to the photocuring process of the base material for photocurable gel nail which is a process (3).
In addition, a gel nail layer may laminate | stack several layers from a viewpoint of improving design property.

3. Formation of Clear Coat Layer In addition, from the viewpoint of protecting the gel nail layer 16 and improving the gloss of the gel nail as shown in FIGS. It is also preferable to provide a clear coat layer 18.
The composition of the clear coat agent 18 ′ for forming the clear coat layer 18 can be the same as the composition of the gel nail composition described above except that it does not contain a colorant as the component (G).
Moreover, it can carry out similarly to the application | coating process and photocuring process of a composition for photocurable gel nails also about an application | coating process and a photocuring process.
FIG. 6 (h) illustrates a case where a dot-like gel nail layer 16a is provided as a variation of the present invention. In this way, the underlayer, the gel nail layer and the clear coat in the present invention are as described above. The layer does not need to be a simple layer, and can be formed in various shapes depending on the required design.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples without a particular reason.

[Example 1]
1. Preparation of Photocurable Gel Nail Base Material The following composition was placed in a container equipped with a stirrer and then mixed until uniform using a stirrer to obtain a photocurable gel nail base material.
(A) Polyether skeleton urethane methacrylate oligomer: 100 parts by weight (B) Isobornyl methacrylate: 35 parts by weight (C) Hydroxyethyl acrylamide: 10 parts by weight (D) Bisphenol A-EO adduct diacrylate: 30 parts by weight Part (F1) α-hydroxyketone compound: 8 parts by weight (F2) Acylphosphine oxide compound: 2 parts by weight (H) Silicone leveling agent: 2 parts by weight

Moreover, the weight average molecular weight of the polyether skeleton urethane methacrylate oligomer which is the component (A) described above was 23,000. The same applies to the following.
Furthermore, as the bisphenol A-EO adduct diacrylate as component (D), an EO repetition number n = 2 manufactured by Osaka Organic Chemical Industry Co., Ltd. was used. The same applies to the following.

Moreover, 1-hydroxy cyclohexyl phenyl ketone (Ciba Co., Ltd. product, IRGACURE184) was used as the (F1) component α-hydroxyketone compound. The same applies to the following.
Furthermore, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (manufactured by BASF Corp., lucillin TPO) was used as the acyl phosphine oxide compound as the component (F2). The same applies to the following.

2. Preparation of photocurable gel nail composition Next, the following composition was placed in a container equipped with a stirrer and then mixed until uniform using a stirrer to obtain a photocurable gel nail composition.
(A) Polyether skeleton urethane methacrylate oligomer: 100 parts by weight (B) Isobornyl methacrylate: 35 parts by weight (D) Bisphenol A-EO adduct diacrylate: 30 parts by weight (E) Dipentaerythritol hexaacrylate: 10 parts by weight (F1) α-hydroxyketone compound: 5 parts by weight (F2) acylphosphine oxide compound: 5 parts by weight (G) organic red pigment: 4 parts by weight (H) silicone leveling agent: 2 parts by weight

3. Formation of Underlayer Next, a base material for photocurable gel nail was applied to the nail of the hand with a brush, and then photocured using a UV device dedicated to gel nail to form an underlayer.
The application conditions and curing conditions of the photocurable gel nail primer are as follows.

(Application conditions)
Viscosity: 20,000 mPa · s (measurement temperature: 25 ° C.)
Brush: Gel nail dedicated brush coating thickness: 0.1-1mm

(Curing conditions)
Irradiation device: Gel nail dedicated UV device Irradiation time: 60 seconds Irradiation amount: 250-400 mJ / cm ²

4). Formation of Gel Nail Layer Next, the photocurable gel nail composition was applied to the obtained underlayer with a brush, and then photocured using a gel nail UV device to form a gel nail layer.
The application conditions and curing conditions for the photocurable gel nail were the same as those for the photocurable gel nail primer.

5. Evaluation (1) Adhesiveness (1) -1 External Resistance The adhesiveness of the obtained nail / underlayer / gel nail layer laminate was evaluated from the viewpoint of external resistance.
That is, the appearance change after scratching the nail on which the base layer and the gel nail layer were formed with another nail 30 times was evaluated according to the following criteria. The obtained results are shown in Table 1.
In addition, peeling between the underlayer and the gel nail layer was not confirmed (the same applies to other examples and comparative examples, except for Examples 14 to 15 and 18 to 19).
A: No change in appearance was confirmed.
◯: Some peeling was confirmed between the nail and the base layer.
(Triangle | delta): Part peeling was confirmed between the nail | claw and the base layer, and whitening was confirmed by a part of external appearance.
X: Remarkable peeling was confirmed between the nail and the base layer, and whitening was confirmed in the entire appearance.

(1) -2 Warm-resistant water Moreover, the adhesiveness in the obtained nail / underlayer / gel nail layer laminate was evaluated from the viewpoint of warm water.
That is, the hands with the base layer and gel nail layer formed on the nails are usually washed with warm water of about 25 ° C. without using soap, and after the washing is finished, the hands are wiped with a towel material. It was performed 30 times a day, and the appearance change after this was continued for 3 days was evaluated according to the following criteria. The obtained results are shown in Table 1.
In addition, peeling between the underlayer and the gel nail layer was not confirmed (the same applies to other examples and comparative examples, except for Examples 14 to 15 and 18 to 19).
A: No change in appearance was observed even after 3 days.
○: Slight peeling was observed between the nail and the base layer within 3 days.
(Triangle | delta): Part peeling was confirmed between the nail | claw and the base layer within 1 day, and whitening was confirmed by a part of external appearance.
X: Remarkable peeling was confirmed between the nail and the base layer within 1 day, and whitening was confirmed in the entire appearance.

(1) -3 Soap Resistance In addition, the adhesion in the obtained nail / underlayer / gel nail layer laminate was evaluated from the viewpoint of soap resistance.
That is, the hand with the base layer and the gel nail layer formed on the nail is usually washed with soap (hand soap) with water at about 25 ° C. After the washing, the hand is wiped with a towel material. The work taken was performed 30 times a day, and the appearance change after continuing this for 3 days was evaluated according to the following criteria. The obtained results are shown in Table 1.
In addition, peeling between the underlayer and the gel nail layer was not confirmed (the same applies to other examples and comparative examples, except for Examples 14 to 15 and 18 to 19).
A: No change in appearance was observed even after 3 days.
○: Slight peeling was confirmed between the nail and the ground layer within 3 days. Δ: Partial peeling was confirmed between the nail and the ground layer within 1 day. Whitening was confirmed in the part.
X: Remarkable peeling was confirmed in the love between the nail and the underlayer within 1 day, and whitening was confirmed in the entire appearance.

(2) Peelability The peelability of the obtained nail / underlayer / gel nail layer laminate was evaluated.
That is, the nail | claw in which the base layer and the gel nail layer were formed, the cloth containing acetone was wound and lightly rubbed, and the peeling condition at that time was evaluated according to the following criteria. The obtained results are shown in Table 1.
In addition, peeling between the underlayer and the gel nail layer was not confirmed (the same applies to other examples and comparative examples, except for Examples 14 to 15 and 18 to 19).
(Double-circle): The laminated body of the peeling layer and the gel nail layer peeled from the nail | claw in less than 15 minutes.
○: The laminate of the base layer and the gel nail layer peeled from the nail in 15 to less than 30 minutes.
(Triangle | delta): The laminated body of the base layer and the gel nail layer peeled from the nail | claw in 30 to less than 45 minutes.
X: The laminated body of the base layer and the gel nail layer did not peel from the nail at 45 minutes.

[Examples 2-3 and Comparative Examples 1-2]
In Examples 2-3 and Comparative Examples 1-2, when preparing the base agent for photocurable gel nail, the blending ratio of the polyether skeleton urethane methacrylate oligomer as the component (A) is shown in Table 1. Except for the change, an underlayer and a gel nail layer were sequentially formed on the nail in the same manner as in Example 1 and evaluated. The obtained results are shown in Table 1.

[Examples 4 to 5 and Comparative Examples 3 to 4]
In Examples 4 to 5 and Comparative Examples 3 to 4, when preparing a base material for photocurable gel nail, the blending ratio of isobornyl methacrylate as component (B) was changed as shown in Table 2. Other than that, an underlayer and a gel nail layer were sequentially formed on the nail in the same manner as in Example 1 and evaluated. The obtained results are shown in Table 2.

[Examples 6 to 7 and Comparative Examples 5 to 6]
In Examples 6 to 7 and Comparative Examples 5 to 6, except that the blending ratio of hydroxyethyl acrylamide as component (C) was changed as shown in Table 3 when preparing the photocurable gel nail base agent. In the same manner as in Example 1, a base layer and a gel nail layer were sequentially formed on the nail and evaluated. The obtained results are shown in Table 3.

[Examples 8-9 and Comparative Examples 7-8]
In Examples 8 to 9 and Comparative Examples 7 to 8, the preparation ratio of the bisphenol A-EO adduct diacrylate which is the component (D) is shown in Table 4 when preparing the photocurable gel nail primer. Except for changing to, an underlayer and a gel nail layer were sequentially formed on the nail in the same manner as in Example 1 and evaluated. Table 4 shows the obtained results.

[Examples 10 to 11 and Comparative Examples 9 to 11]
In Examples 10 to 11 and Comparative Examples 9 to 11, when preparing a photocurable gel nail base agent, dipentaerythritol hexaacrylate was blended as component (E), and the blending ratio is shown in Table 5. The undercoat layer and the gel nail layer were sequentially formed on the nail in the same manner as in Example 1 except that the changes were made. The results obtained are shown in Table 5.

[Examples 12 to 19]
In Examples 12 to 19, after the base layer and the gel nail layer were sequentially formed on the nail, a case where a clear coat agent was further applied to the gel nail layer and a clear coat layer was formed was evaluated.
That is, the base composition for photocurable gel nail 1-2 having the composition shown in Table 6, the photocurable gel nail composition 1-4, and the clear coat agent 1 are combined with the combination shown in Table 7 with respect to the nail. Laminated and evaluated. The results obtained are shown in Table 7.
The application conditions and curing conditions for the photocurable gel nail primer, the photocurable gel nail composition, and the clearcoat agent are the same as those for the photocurable gel nail primer in Example 1. It is the same.

＊実施例１４〜１５および１８〜１９においては、下地層とジェルネイル層との間において若干の剥離が確認された。

* In Examples 14 to 15 and 18 to 19, slight peeling was confirmed between the underlayer and the gel nail layer.

[Comparative Examples 12-15]
In Comparative Examples 12 to 15, when preparing the photocurable gel nail primer, instead of the polyether skeleton urethane methacrylate oligomer as the component (A), a polyether skeleton urethane acrylate oligomer (weight average molecular weight: 25). , 000) and the blending ratio was changed as shown in Table 8, and a base layer and a gel nail layer were sequentially formed on the nail in the same manner as in Example 1 and evaluated. Table 8 shows the obtained results.

[Comparative Examples 16 to 19]
In Comparative Examples 16 to 19, when preparing a base material for photocurable gel nail, instead of the polyether skeleton urethane methacrylate oligomer as the component (A), a polyester skeleton urethane methacrylate oligomer (weight average molecular weight: 30). In addition, the base layer and the gel nail layer were sequentially formed on the nail in the same manner as in Example 1 except that the blending ratio was changed as shown in Table 9. Table 9 shows the obtained results.

[Comparative Examples 20-23]
In Comparative Examples 20 to 23, the formation of the base layer on the nail was omitted, and a photocurable gel nail composition or the like was laminated and evaluated in the combinations shown in Table 10. Table 10 shows the obtained results.
The application conditions and curing conditions for the photocurable gel nail primer and the like are the same as those for the photocurable gel nail primer in Example 1.

According to the photocurable gel nail primer of the present invention and the gel nail method using the same, a predetermined urethane methacrylate oligomer, a predetermined (meth) acrylate monomer, a predetermined acrylamide monomer, and a predetermined 2 By including a functional (meth) acrylate monomer and a photopolymerization initiator in a predetermined blending ratio and substantially free of a polyfunctional (meth) acrylate monomer having three or more functions, adhesion to a nail and peeling It is possible to form an undercoat layer that not only has a good balance of properties but also has a high curing rate and also has excellent adhesion to a gel nail layer laminated thereon.
Therefore, the photocurable gel nail primer and the gel nail method using the same of the present invention are expected to contribute significantly to improving the quality of the gel nail.

10: nail, 10 ': finger, 12: foundation layer, 12': foundation agent (coating layer) for photocurable gel nail, 14: light irradiation device, 14a: ultraviolet ray, 16: gel nail layer, 16a: dot shape Gel nail layer, 16 ': light curable gel nail composition (coating layer), 18: clear coat layer, 18': clear coating agent (coating layer)

Claims (9)

A photocurable gel nail base material comprising the following components (A) to (F):
(A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate monomer 20-60 parts by weight (C) Acrylamide monomer which is liquid at 25 ° C. 5-20 parts by weight (D) molecule Bifunctional (meth) acrylate monomer with ethylene oxide inside
20 to 40 parts by weight (E) Trifunctional or higher polyfunctional (meth) acrylate monomer
0 parts by weight , or 0 to 1 part by weight
(However, 0 parts by weight are not included.)
(F) Photopolymerization initiator 5 to 20 parts by weight   The weight average molecular weight of the polyether skeleton urethane methacrylate oligomer as the component (A) is set to a value in the range of 10,000 to 50,000, for photocurable gel nails according to claim 1 Base agent.   The base agent for a photocurable gel nail according to claim 1 or 2, wherein the alicyclic (meth) acrylate monomer as the component (B) is isobornyl methacrylate.   The primer for photocurable gel nail according to any one of claims 1 to 3, wherein the acrylamide monomer that is liquid at 25 ° C as the component (C) is hydroxyethylacrylamide.   The bifunctional (meth) acrylate monomer having ethylene oxide in the molecule as the component (D) is bisphenol A-ethylene oxide adduct diacrylate, according to any one of claims 1 to 4. The base material for photocurable gel nails as described.   The photopolymerization initiator as the component (F) contains an acyl phosphine oxide compound and an α-hydroxyketone compound and / or a benzophenone compound, or any one of them. The base agent for photocurable gel nails according to any one of the above. A gel nail method using a photocurable gel nail primer, comprising the following steps (1) to (5).
(1) Step of preparing a photocurable gel nail primer containing the following components (A) to (F) (A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate Monomer 20-60 parts by weight (C) Acrylamide monomer which is liquid at 25 ° C. 5-20 parts by weight (D) Bifunctional (meth) acrylate monomer having ethylene oxide in the molecule
20 to 40 parts by weight (E) Trifunctional or higher polyfunctional (meth) acrylate monomer
0 parts by weight , or 0 to 1 part by weight
(However, 0 parts by weight are not included.)
(F) Photopolymerization initiator 5 to 20 parts by weight (2) Step of applying the photocurable gel nail primer to the nail (3) Photocuring the applied photocurable gel nail primer Step (4) of applying a photocurable gel nail composition to the base layer (5) Photocuring the applied photocurable gel nail composition to form a gel nail layer Forming process The photocurable gel nail composition in the step (4) contains the following component (A), component (B), component (D), component (E ′), and component (F). The gel nail method according to claim 7.
(A) Polyether skeleton urethane methacrylate oligomer 100 parts by weight (B) Alicyclic (meth) acrylate monomer 20-60 parts by weight (D) Bifunctional (meth) acrylate monomer having ethylene oxide in the molecule
20-40 parts by weight (E ′) Trifunctional or higher polyfunctional (meth) acrylate monomer 5-20 parts by weight (F) Photopolymerization initiator 5-20 parts by weight The gel nail method according to claim 8, wherein the trifunctional or higher polyfunctional (meth) acrylate monomer as the component (E ') is dipentaerythritol hexaacrylate.

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