JP6351941B2 - Cosmetic puff and method for producing the same - Google Patents

Description

  The present invention relates to a cosmetic puff and a method for producing the same.

  A makeup puff (sponge sponge puff) is required to have a moist skin texture. Here, as a method for using the cosmetic puff, a cosmetic foundation is directly applied to the cosmetic puff and applied to the skin (use without water), or the cosmetic puff is once impregnated with water. There is a method (use with water) in which a cosmetic foundation is applied after moistening with water by squeezing lightly afterwards and applying this to the skin. By moistening the cosmetic puff with water, the cosmetic puff is soft and moist, and the foundation puff is excellent and the cosmetic effect is excellent. This is because the resin surface of the cosmetic puff is wet with water, and the hydrophobic particles of the foundation float on the surface, so that the transfer to the skin becomes good. In order to exhibit such characteristics, foundations specifically for use with water are on the market. Many foundations are manufactured as a dual-use type with and without water.

  In order to further improve the effect of such a cosmetic puff, by making the resin surface of the puff hydrophilic, water is strong against the surface during use, and the foundation is uniformly stretched and has an excellent foundation elongation. As such a hydrophilization technique, for example, Patent Document 1 proposes a method of adsorbing a cationic active agent on a latex sponge rubber blended with carboxy-modified NBR. Patent Document 2 proposes a method of graft polymerization of polyethylene glycol dimethacrylate on latex sponge rubber. Furthermore, Patent Document 3 proposes a method in which a latex sponge rubber is impregnated with a polyethylene glycol (meth) acrylate aqueous solution at a temperature below the cloud point, and then precipitated and reacted at a cloud point or higher. Moreover, in patent document 4, after performing the pre-processing process which makes 1 or more types of washing | cleaning liquid selected from the group which consists of a polar solvent and alkaline aqueous solution contact NBR or SBR latex sponge rubber as a pre-processing process, A method of impregnating and reacting has been proposed.

JP 2005-139300 A JP 63-268751 A JP 2012-25874 A JP 2012-16209 A

  However, cosmetic puffs formed by these methods have improvements in terms of surface dirt removal and resistance to repeated washing. Furthermore, regarding the method of bonding the hydrophilic monomer component to the rubber skeleton, most of the hydrophilic monomer component penetrates into the rubber skeleton. As a result of the presence of many hydrophilic components even inside the rubber skeleton, swelling occurs when brought into contact with water. And there was a problem that deterioration of a material might be concerned by repeating swelling and drying (expansion and contraction). Furthermore, the method for producing a hydrophilic rubber molded body according to Patent Document 2 has a problem that the treatment process is complicated and requires a long time because the graft polymerization treatment is performed. Furthermore, the cosmetic puff preferably has excellent flexibility.

  Regarding the above-mentioned problems, the present inventors provide a specific primer layer on at least the surface of the rubber molded body without using a complicated graft polymerization reaction, etc., and specify the primer layer using a specific method. By adding a specific polymer and adding a specific plasticizer, swelling is suppressed, the surface is highly soil-resistant, and it can exhibit anti-stain properties even after repeated use, and has excellent flexibility. The present inventors have found that a cosmetic puff having the above can be produced.

That is, according to the present invention, a network structure having a siloxane bond represented by Si—O—Si or a silazane bond represented by Si—NH—Si as a skeleton is present on at least a part of the surface of the rubber molded body. There is provided a cosmetic puff comprising a hydrophilic rubber molded body in which a primer layer comprising an inorganic silicon compound and a hydrophilic polymer are bonded via a siloxane bond.
In the hydrophilic rubber molded body, it is preferable that at least a part of the hydrophilic polymer has a (meth) acrylic acid ester containing a betaine group.
In the hydrophilic rubber molded body, the betaine group is preferably a carboxybetaine group.
In the hydrophilic rubber molded body, it is preferable that at least a part of the hydrophilic polymer is bonded to the primer layer only at the end of the main chain.
In the hydrophilic rubber molded body, the hydrophilic polymer preferably has a weight average molecular weight of 300 to 50,000.
In the hydrophilic rubber molded body, the rubber molded body may be a foam.
In the hydrophilic rubber molded body, the foam may have open cells.
In the hydrophilic rubber molded body, the rubber molded body is preferably NBR.
Further, according to the present invention, at least a part of the surface of the rubber foam is made of water glass, alkoxysilanes, or a partially hydrolyzed product or partially hydrolyzed condensate thereof, silicone, silazane, nitrogen-containing silicone resin, nitrogen-containing silane. By treating with one or more components selected from the group consisting of a coupling agent or a partial hydrolyzate thereof, a siloxane bond represented by Si—O—Si having a hydroxyl group on the surface or Si—NH— A surface treatment step for forming a primer layer composed of an inorganic silicon compound having a network structure having a silazane bond represented by Si as a skeleton, and a hydrophilization step for bonding a hydrophilic polymer to the surface of the primer layer by a silane coupling reaction And a step of incorporating a surfactant containing a betaine group into the rubber foam.粧用 puff manufacturing method is provided. Here, in the present specification and claims, not only when the surface treatment step is performed first and then the hydrophilization step is subsequently performed (two-step step), but both steps are simultaneously performed (separated). (Including) a case of executing (one-step process).
In the method for producing a cosmetic puff, the hydrophilic polymer preferably has a (meth) acrylic acid ester containing a betaine group.
In the method for producing a cosmetic puff, the betaine group is preferably a carboxybetaine group.
In the method for producing a cosmetic puff, it is preferable that the hydrophilization step is a step of using, as the hydrophilic polymer, a hydrophilic polymer that can bind to the primer layer only at the end of the main chain.
In the method for producing a cosmetic puff, the hydrolyzing step uses the hydrolyzable polymer having a hydrolyzable silyl group introduced at least at one end of the main chain of the hydrophilic polymer as the hydrophilic polymer. It is preferable that the hydrophilic polymer is bonded to the surface by dehydration condensation with the hydroxyl group of the primer layer by silane coupling reaction after hydrolyzing the silyl group.
In the method for producing a cosmetic puff, the hydrophilic polymer preferably has a weight average molecular weight of 300 to 50,000.
In the method for producing a cosmetic puff, the rubber molded body may be a foam.
In the method for producing a cosmetic puff, the foam may have open cells.
In the method for producing a cosmetic puff, the rubber molded body is preferably NBR.

  According to the present invention, a complicated pretreatment process is not required, the oil has a high dirt removal property (even with water alone, the foundation stain is removed), and the hydrophilicity does not easily deteriorate even after repeated washing, so that the stain removal effect is achieved. It is possible to provide a cosmetic puff made of a hydrophilic rubber molded article having a high durability (strong against repeated washing), a low swelling rate due to contact with water, and an excellent flexibility.

FIG. 1 is a diagram showing an example of a manufacturing process for a cosmetic puff according to the present embodiment. FIG. 2 is a time-series conceptual diagram (example) of a manufacturing process example of a cosmetic puff according to this embodiment and a surface state of the puff by the manufacturing process. FIG. 3 is a diagram showing the relationship of the stroke (distortion) to the test force of the cosmetic puff according to the example and the comparative example.

  Hereinafter, the structure, manufacturing method, physical properties, and the like of the cosmetic puff made of the hydrophilic rubber molded body according to the present embodiment will be described in order, but the present embodiment is not limited by these.

≪Structure etc. of hydrophilic rubber moldings≫
First, the structure of the hydrophilic rubber molded body constituting the cosmetic puff according to this embodiment will be described. The hydrophilic rubber molded body according to this embodiment is present on at least a part (or the entire surface) of the surface of the rubber molded body, and is represented by a siloxane bond represented by Si—O—Si or Si—NH—Si. A hydrophilic rubber comprising a primer layer composed of a network-structured inorganic silicon compound having a silazane bond as a skeleton and a hydrophilic polymer bonded via a siloxane bond and further containing a surfactant containing a betaine group It relates to a molded body. Hereinafter, a surfactant (betaine surfactant) containing a rubber molded body, a primer layer, a hydrophilic polymer, and a betaine group, which is a constituent material of the cosmetic puff according to the present embodiment, will be described.

<Rubber molding>
The rubber molded body which is the core material of the hydrophilic rubber molded body constituting the cosmetic puff according to this embodiment will be described. The shape of the rubber molded body according to the present embodiment is not particularly limited, but is a polygon such as a rectangle, square, circle, ellipse, rhombus, or a rectangular or doughnut-shaped interior, The thing which gave arbitrary unevenness to the surface etc. are mentioned.

(composition)
As the rubber molded body according to this embodiment, NBR, HNBR, FKM, ACM, VMQ, AU, EPDM, CR, CSM, CO, NR, IR, SBR, BR, T, NOR, TPE, etc. are generally used. Various things made of rubber can be suitably applied. In particular, when a nitrogen-containing organic silane coupling agent such as aminosilane is used as a raw material, in order to strongly adhere (anchor effect) to NBR that also contains nitrogen, from the viewpoint of maintaining long-term hydrophilicity and the like, Therefore, NBR is extremely good.

(Foam)
The structure of the rubber molded body is a foamed structure. Here, the foam structure is preferably open-celled.

<Primer layer>
As described above, the primer layer of the hydrophilic rubber molded body constituting the cosmetic puff according to the present embodiment is present at least on the surface of the rubber molded body, is composed of inorganic silicon bonds, and the primer layer and the hydrophilic polymer are present. By bonding through a siloxane bond, hydrophilicity is imparted to the rubber molded body.

(composition)
The primer layer according to the present embodiment has an inorganic silicon bond, and the inorganic silicon bond has a siloxane bond represented by Si—O—Si or a silazane bond represented by Si—NH—Si as a skeleton. The primer layer has a network structure based on this skeleton, and the hydrophilic polymer is bonded through a large number of bonding points existing in the network, whereby a large number of hydrophilic polymers can be firmly bonded. (I.e., the amount of unbound polymer can be reduced, and as a result, the hydrophilic polymer is present without flowing off from the rubber molded body).

(Network structure)
The inorganic silicon bond of the primer layer according to this embodiment has a network structure. Since a network-like inorganic silicon bond is formed by a strong bond called a covalent bond, swelling with water is suppressed in the hydrophilic rubber molded body. In addition, since the inorganic silicon bond has a network structure, the hydrophilic polymer can be bonded in a wide range (in other words, it has a large number of bonding points). Improves dirt removal. In addition, according to this embodiment, the hydrophilic polymer is bonded to many bonding points on the network (in other words, the amount of the hydrophilic polymer not bonded is small), and the rubber of the primer layer Since the adhesiveness to the molded body is high and the peeling of the primer layer (+ the hydrophilic polymer bonded thereto) is suppressed, it is possible to improve the resistance to repeated washing of the cosmetic puff. The inorganic silicon compound having a network structure is, as is well known in the art, the siloxane bond or silazane bond of the inorganic silicon compound crosses and bonds at a number of points and spreads like a network. It shows that a structure is formed.

(Layer thickness)
The thickness (coating amount: solid content) of the primer layer according to this embodiment is not particularly defined, but is preferably 0.001 to 0.05 g / 16 cm ³ , and more preferably 0.003 to 0, for example. 0.03 g / 16 cm ³ . When the primer layer thickness exceeds 0.05 g / cm ³ , when the hydrophilic rubber molding is deformed, the followability to the deformation is deteriorated, and the primer layer may be easily cracked. Moreover, the obtained rubber molded body may become hard and the touch as a cosmetic puff may be impaired. When the primer layer thickness is less than 0.001 g / 16 cm ³ , the adhesion strength of the primer layer to the rubber molded article may be insufficient, and sufficient resistance to repeated cleaning may not be obtained.

<Hydrophilic polymer>
The hydrophilic polymer constituting the cosmetic puff according to this embodiment is bonded to the primer layer through a siloxane bond. One or a plurality of the siloxane bonds may be present for one polymer structure, and may be present at any position of the main chain and the side chain. Here, when a plurality of siloxane bonds bonded to the primer layer are present in one polymer structure, the hydrophilic polymer is more strongly bonded to the primer layer, so that the resistance to repeated washing can be increased. However, when the cosmetic puff is compressed or deformed, the polymer may be broken by a load received from the bonded portion, and the dirt removal property may be easily deteriorated. On the other hand, when a plurality of bonding sites with the primer layer do not exist in the polymer structure, such a problem hardly occurs. In addition, when the hydrophilic polymer is bonded to the primer layer through the siloxane bond only at the end of the main chain, the hydrophilic polymer is bonded to the end when the periphery of the hydrophilic polymer is in a water atmosphere. It is more preferable because the effect of improving the dirt removal property by increasing the height of the part by using the foot as a foot is increased. It is more preferable that the hydrophilic polymer has a brush-like skeleton.

(composition)
The hydrophilic polymer according to this embodiment is not particularly limited as long as it has hydrophilicity, and can be suitably applied. For example, homo- and copolymers of water-soluble monomer components such as acrylic acid, methacrylic acid, crotonic acid, acrylamide propane sulfonic acid, vinyl phosphonic acid, maleic acid, vinyl sulfonic acid and their salts, alkali metal and ammonium salts, etc. Is mentioned. Other monomer components include acrylamide, N-vinyl amide, hydroxyalkyl esters of acrylic and methacrylic acid and basic and cationic monomer components such as basic esters and amides of acrylic and methacrylic acid such as dimethylaminoethanol. Examples thereof include esters, N-dimethylaminopropylmethacrylamide, dimethyldiallylammonium chloride, and vinylimidazoline. Here, the hydrophilic polymer according to the present embodiment is more preferably a (meth) acrylic acid ester having a betaine group from the viewpoint that strong hydrophilicity can be exhibited, and the viewpoint of further enhancing the hydrophilicity. Therefore, it is more preferable that it is a (meth) acrylic acid ester having a carboxybetaine group. In addition, in this embodiment, having hydrophilicity indicates that it can be wetted in a water atmosphere. Wetting indicates that a liquid (eg, an aqueous solution) can penetrate into the sample or diffuse to its surface.

The weight average molecular weight of the polymer is preferably 300 to 500,000, and more preferably 5,000 to 300,000. When the weight average molecular weight is less than 300, as described above, when the periphery of the hydrophilic polymer becomes a water atmosphere, dirt removal performance (force to push out the dirt) by standing up with the hydrophilic polymer binding part as a foot ) Cannot be obtained sufficiently. On the other hand, if the weight average molecular weight exceeds 500,000, swelling is likely to occur in a water atmosphere. Here, the said weight average molecular weight is a weight average molecular weight measured by GPC-LALLS method. The measuring method is shown below.
1) GPC
Apparatus: Waters type 244 gel permeation chromatograph column: Tosoh TSK-gel-GMPW
(Inner diameter 8mm, length 30cm, 2)
Solvent: 0.1 M Tris buffer (pH 7.9)
Flow rate: 0.5 ml / min
Temperature: 23 ° C
Sample concentration: 0.040%
Filtration: 0.45 μm Mysori disk W-25-5 made by Tosoh
Injection volume: 0.2ml
Detection sensitivity (differential refractive index detector): 4 times 2) LALLS
Apparatus: Chromatrix KMX-6 type low angle laser light scattering photometer Temperature: 23 ° C
Wavelength: 633nm
Second virial coefficient × concentration: 0 mol / g
Refractive index density change (dn / dc): 0.159 ml / g
Filter: MILLIPORE 0.45 μm filter HAWP01300
Gain: 800mV

<Surfactant having betaine group>
The surfactant having a betaine group according to this embodiment (betaine surfactant) is not particularly limited, and examples thereof include carboxybetaine surfactants, amide betaine surfactants, sulfobetaine surfactants, and hydroxysulfones. Betaine surfactants, amidosulfobetaine surfactants, and phosphobetaine surfactants. More specifically, (1) a carboxybetaine surfactant having an alkyl group, alkenyl group or acyl group having 8 to 24 carbon atoms (preferably 12 to 18 carbon atoms), and (2) 8 to 24 carbon atoms (preferably Amide betaine surfactant having 12-18) alkyl group, alkenyl group or acyl group, (3) alkyl group, alkenyl group or acyl group having 8-24 carbon atoms (preferably 12-18). A sulfobetaine surfactant having (4) a hydroxysulfobetaine surfactant having an alkyl group, an alkenyl group or an acyl group having 8 to 24 carbon atoms (preferably 12 to 18 carbon atoms); An amide sulfobetaine surfactant having 24 (preferably 12 to 18) alkyl, alkenyl or acyl group; (6) an alkyl having 8 to 24 carbon atoms (preferably 12 to 18). Group, an alkenyl group or phosphobetaine type surfactants having an acyl group, and the like.

Of these, carboxybetaine surfactants are particularly suitable from the viewpoint of improving the repeatability. For example, a carboxybetaine surfactant represented by the following formula is suitable. R in the formula is an alkyl group, alkenyl group or acyl group having 8 to 24 (preferably 12 to 18) carbon atoms.

≪Method for producing hydrophilic rubber molded body≫
Next, a manufacturing process, a raw material, etc. are demonstrated as a manufacturing process of the hydrophilic rubber molding which concerns on this form. Here, as shown in FIG. 1, the manufacturing method of the cosmetic puff according to this embodiment is roughly divided into (1) a two-stage manufacturing method {manufacturing example in the case of using a water glass system (solvent system) for the primer} and (2) One-stage production method (production example in the case of using an aqueous primer). The step of adding a surfactant containing a betaine group is preferably carried out after the hydrophilic polymer is bound to the primer layer by carrying out the one-step production method and the two-step production method. It may be carried out simultaneously with any step of the stepwise manufacturing method or the two-step manufacturing method (for example, in the mode of adding the surfactant to the drug used in the one-step manufacturing method, before the hydrophilic polymer in the two-step manufacturing method is bonded) A mode in which a surfactant is added A mode in which the surfactant is added to a drug that binds a hydrophilic polymer in a two-stage production method). And each layer is formed with each manufacturing method by the action mechanism shown in FIG. However, FIG. 2 is merely an assumed conceptual diagram (and a specific material is exemplified as a material). For example, in the case of a one-step manufacturing method, a hydrophilic polymer layer is not neatly formed on a primer layer. In some cases, a hydrophilic polymer is incorporated into the skeleton of the network structure. Each will be described in detail below.

≪Two-stage process≫
<Manufacturing process>
A method for producing a cosmetic puff comprising a hydrophilic rubber molded body according to this embodiment includes a surface treatment step for forming a primer layer on the rubber molded body, and a hydrophilic polymer is bonded to the primer layer by a silane coupling reaction. A hydrophilization step, and a step of introducing a surfactant containing a betaine group. Each will be described in detail below. In addition, in the manufacturing method of the cosmetic puff which consists of a hydrophilic rubber molding which concerns on this form, you may have the degreasing process etc. which remove the impurity of a rubber molding further before the said surface treatment process.

(Surface treatment process)
The liquid primer is applied to at least a part of the surface of the rubber molded body, and then dried, and the surface of the rubber molded body is covered with a primer layer having hydroxyl groups on the surface. Various conditions in the surface treatment process will be described below.
Raw material (1) Primer The primer is not limited as long as it can form an inorganic silicon compound having a siloxane bond represented by Si—O—Si or a silazane bond represented by Si—NH—Si as a skeleton. . Specifically, examples of the component for forming the silicon oxide matrix include water glass, alkoxysilanes used in the sol-gel method, or a partially hydrolyzed product or partially hydrolyzed condensate thereof, and silicone. Further, when nitrogen is contained in the silicon oxide matrix, silazane, nitrogen-containing silicone resin, nitrogen-containing silane coupling agent (for example, aminosilane), partial hydrolyzate thereof, and the like can be given. These may be used in combination. In addition, you may use a solvent (diluent) suitably, when a primer is highly viscous.

Here, “water glass” is a water-soluble alkali metal silicate represented by the general formula [nSiO _2. “M” ₂ O] (where “M” is an alkali metal and “n” is a positive integer). . In particular, sodium silicate is inexpensive and preferable.

Silazane is a compound having a Si—N—Si bond, and is polysilazane such as disilazane (R ₃ Si) ₂ NH, cyclosilazane (R ₂ SiNH) _n , polycyclosilazane [RSi (NH) _{1. 5} ] _{n and the} like. Here, polysilazane has a structure represented by the chemical formula: —SiR ¹ ₂ —NR ² —SiR ¹ ₂ — (wherein R ¹ and R ² each independently represents a hydrogen atom or a hydrocarbon group). It is a general term for linear or cyclic compounds. Polysilazane is a material in which Si—NR ² —Si bonds are decomposed by heating or reaction with moisture to form a Si—O—Si network. The polysilazane is a perhydropolysilazane in which R ¹ and R ² in the above chemical formula are both hydrogen atoms, a partially organized polysilazane in which R ¹ in the above chemical formula is a hydrocarbon group such as a methyl group and R ² is a hydrogen atom, And mixtures thereof are preferred. In the above formula, the number of carbon atoms of the hydrocarbon group represented by R ¹ and R ² is not particularly limited, but is preferably small, more preferably 20 or less, and particularly preferably 4 or less.

  A commercial item can be used as said component, and it is also possible to manufacture by arbitrary methods. For example, as the alkoxysilanes used in the sol-gel method, those described in JP 2007-246872 A can be used, for example, TSR127B (trade name, manufactured by Momentive Performance Materials Japan Co., Ltd.) Can be used. As polysilazane, AQUAMICA NP-110AZ (trade name, manufactured by Electro Materials, Inc .; perhydropolysilazane) can be used. As the nitrogen-containing silicone resin, those described in JP-A-2002-13077 can be used. As the nitrogen-containing silane coupling agent, those described in JP-A No. 2004-124000 can be used.

Process As a method of applying the primer agent to the rubber molded body, for example, a method of impregnating the rubber molded body in the primer agent or a method of applying the primer agent to the rubber molded body by a method such as spray coating may be used. There is no limitation. When the rubber molded body is subjected to a hydrophilic treatment in the hydrophilic step, the rubber molded body may be kept wet with the primer agent or may be dried. The temperature and working environment of the primer agent are not particularly limited, but may be an environment of 30 ° C. or lower, for example. Even when the primer is dried, the drying method is not limited, and it may be left in the air or dried using a hot air blower (for example, drying by blowing air of 30 ° C. or less). Here, if necessary, the surface treatment step may further include a step for forming a hydroxyl group on the surface of the primer layer. Even when such a step is required, a hydroxyl group is formed on the surface of the primer layer. Can be selected as appropriate according to the properties of the selected raw material and the like. For example, a step of exposing the primer layer to the air after forming the primer layer on the rubber molded body can be considered, but in the case where a hydroxyl group is formed on the surface of the primer layer at the stage of forming the primer layer, etc. Such a process is not always necessary.

(Hydrophilic process)
In the surface treatment step, hydrophilic property is imparted to the rubber foam by bonding a hydrophilic polymer to the primer layer covering at least a part of the surface of the rubber foam by a silane coupling reaction. Various conditions in the hydrophilization process will be described below.
-Raw material (2) hydrophilic polymer Since the composition of the hydrophilic polymer and the like in the method for producing a hydrophilic rubber molded body according to the present embodiment are as described above, detailed description thereof is omitted here.
Raw Material (3) Silane Coupling Agent Any silane coupling agent used in the hydrophilization step can be used as long as it has binding properties with the primer layer and the hydrophilic polymer. For example, as an organic functional group, amino, vinyl, methacryl, isocyanate, mercapto, sulfur, ureido, epoxy, etc., and as a hydrolyzing group, methoxy, ethoxy, methoxyethoxy, etc. are appropriately selected, and a silane coupling agent can be used. Good.
-Process As a method of applying a hydrophilizing agent to the rubber molded body on which the primer layer has been formed through the surface treatment step, for example, a method of impregnating the rubber molded body in the hydrophilizing agent may be spray coating. A method of applying a hydrophilic treatment agent to the rubber molded body by a method such as the above may be used, and the method is not limited at all. Then, for example, heating in an oven (for example, 80 ° C. for 1 hour), and using the hydroxyl group present on the surface of the rubber molded body (primer layer) as a bond, the primer layer of the rubber molded body and the hydrophilic polymer are coupled with silane coupling. Combine by reaction. In addition, the process conditions (for example, oven temperature, heating time, etc.) in a hydrophilization process are not specifically limited, It can set suitably according to the kind of coupling agent, the kind of rubber molded object, etc.

  As described above, as the hydrophilization step, as described above (first method), the primer layer is subjected to silane coupling treatment using a silane coupling agent, and then to the silane coupling treatment layer. A hydrophilic polymer may be bonded, or (second method) a silanol group-containing hydrophilic polymer is formed by previously polymerizing a silane coupling agent and a hydrophilic polymer, and the silanol group-containing hydrophilic polymer is used as a primer. It may include a silane coupling step for bonding to the layer. Furthermore, (third method) silane coupling treatment using a silane coupling agent is performed on the primer layer, and then a hydrophilic monomer (a hydrophobic monomer may be added in some cases) is polymerized. It may be a step of forming a hydrophilic polymer group. However, the second method is preferable from the viewpoint of simplifying the processing steps and shortening the processing time. In addition, since the second method is easy to control so that the silanol group is located only at the end of the main chain of the hydrophilic polymer, control is performed so that the primer layer is bonded to the primer layer only at the end of the main chain of the hydrophilic polymer. It is also preferable from the viewpoint that it becomes easy.

(Introduction process of surfactant containing betaine group)
Hereinafter, a suitable introduction process will be described. By introducing a surfactant having a betaine group into the rubber foam that has been rendered hydrophilic in the hydrophilization step, the cosmetic puff is given flexibility and is also more resistant to repeated use. Adds dirtiness. A suitable introduction method is, for example, a method in which a puff to which a hydrophilic polymer is bonded is impregnated with an aqueous surfactant solution having a betaine group and then dried. Hereinafter, various conditions in the hydrophilization process will be described.
Raw material (4) Surfactant having betaine group Since the surfactant having a betaine group in the method for producing a hydrophilic rubber molded body according to this embodiment is as described above, detailed description thereof is omitted here. . In addition, you may combine 2 or more types instead of 1 type of surfactant. Further, when a (meth) acrylic acid ester containing a betaine group is used as a raw material for the hydrophilic polymer, it is preferable to use a surfactant having a carboxybetaine group. This is because, in particular, the repeatability becomes high.
Process As described above, a method in which the puff to which the hydrophilic polymer is bonded is impregnated with an aqueous surfactant solution having a betaine group and then dried is preferable. At this time, the puff in the impregnated state is lightly squeezed in the liquid so that the gas inside the puff escapes, and then the puff is taken out from the impregnating liquid and subjected to centrifugal dehydration. Thereafter, for example, drying is performed with a dryer (for example, a hot air dryer).

≪One-step process≫
A method for producing a cosmetic puff comprising a hydrophilic rubber molded body according to this embodiment includes a surface treatment step for forming a primer layer on the rubber molded body, and a hydrophilic polymer is bonded to the primer layer by a silane coupling reaction. And the hydrophilization step to be performed simultaneously (without dividing). Specifically, the present production method is a method in which a mixed solution of a primer agent and a silanol group-containing hydrophilic polymer (or a silane coupling agent and a hydrophilic polymer) is applied (for example, impregnated) to a rubber molded body and heated. It is.

  More specifically, when both the primer agent and the silanol group-containing hydrophilic polymer are components that dissolve in water or components that are stably dispersed without settling / separating, a one-step process can be employed ( For example, the primer agent is aminosilane exemplified in the two-step process). The step of introducing a surfactant containing a betaine group is the same as described in the two-step process, and is therefore omitted.

≪Remarks≫
Here, points to be noted when silazane is used as a primer agent will be described (see FIG. 2 as necessary). General silazane can exist only in a solvent without water. Under such properties, after solvent drying, hydrolysis is performed while releasing ammonia and hydrogen by moisture, and finally Si—O—Si is formed. The primer effect is exhibited when SiOH is generated in the first stage of hydrolysis. An anchor effect is demonstrated by making a hydrophilic treatment agent act in this state.

  In addition, an action mechanism in which a Si—O—Si or Si—N—Si network structure is formed and an action mechanism in which a hydrophilic component is bonded to the network structure will be described. In addition, these action mechanisms are well known.

  First, the case where silazane or a solvent system is used as a primer agent will be described. When these primer agents are used, the primer agents are condensed during application (for example, application) / heated after drying to form a network. More specifically, for example, when silazane is used, if water is present, it decomposes and Si—OH is generated. Further heating causes Si—O—Si bonds. Next, when alkoxysilanes are used as primer agents, they are usually in the Si-OR state, but are heated in the presence of water after the solvent has been blown off, so that hydrolysis (Si-OH generation) Dehydration condensation results in Si—O—Si bonds. Thus, in the case of silazane or a solvent system, a thin glass film is formed on the surface, and a hydrophilic polymer is newly bonded to the glass film via a silane coupling skeleton.

  Next, the case where an aqueous system is used as a primer agent will be described. Even in the case of an aqueous system, a network is formed by condensation in the process of heating after application (for example, application) and drying of the primer agent. More specifically, the primer component (for example, aminosilane) exists in a hydrolyzed state (Si—OH) in an aqueous solution. Then, when it is applied (for example, applied), dried and heated, it condenses to form Si—O—Si bonds. However, in the case of a one-step process, the hydrophilic treatment agent may be incorporated into a part of the network structure as a result of the presence of the hydrophilic treatment agent during the formation of the Si—O—Si network (this aspect is also within the scope of the present invention). Is).

  According to the method for producing a cosmetic puff comprising the hydrophilic rubber molded body according to this embodiment, at least a part of the surface of the rubber molded body can form a network-like inorganic silicon bond by a strong bond called a covalent bond. Therefore, as described above, swelling with water is suppressed in the hydrophilic rubber molded body. Further, as described above, the hydrophilic polymer can be bonded in a wide range (in other words, bonded to a large number of bonding points on the network). Improves. In addition, the amount of unbound hydrophilic polymer can be reduced and the adhesion of the primer layer to the rubber molded body can be increased, resulting in outflow of unbound hydrophilic polymer and peeling of the primer layer. It is possible to prevent the decrease in hydrophilicity and improve the resistance to repeated washing of the cosmetic puff. For example, even when the rubber molded body is a foam (particularly a continuous foam), the hydrophilic polymer should be present near the surface layer so that the hydrophilic polymer does not exist inside the rubber molded body. Therefore, even when the hydrophilic rubber molding is impregnated with water, the hydrophilic polymer is prevented from adsorbing water and swelling inside the rubber molding to obtain a low-swelling cosmetic puff. It becomes possible.

≪Physical properties of hydrophilic rubber moldings≫
Next, the physical properties of the cosmetic puff made of the hydrophilic rubber molded body according to this embodiment will be described. The cosmetic puff comprising the hydrophilic rubber molded body according to the present embodiment has a low swelling rate, resistance to repeated washing, high hydrophilicity and high oil stain removal (typically foundation removal).

<Swelling rate>
Swelling occurs when water is accumulated in the structure when a cosmetic puff made of a rubber molded body (particularly a continuous foam) is immersed in water. That is, the higher the hydrophilicity of the rubber molded body, the higher the swelling ratio. However, as described above, the hydrophilic rubber molded body according to this embodiment forms a network-like inorganic silicon bond by a strong bond called a covalent bond as described above. Therefore, the swelling rate is kept low. Furthermore, when a rubber molded body is produced by the production method according to the present embodiment, since a large number of bonding points exist in the network structure of the primer layer, most of the hydrophilic polymer to be used is bonded to the primer layer. It is understood that the hydrophilic polymer hardly penetrates into the rubber molded body (in particular, the open cell body). It is considered that the swelling is also suppressed by this, that is, when there is almost no hydrophilic polymer present inside.

<Repeatable cleaning resistance>
The cosmetic puff made of the hydrophilic rubber molded body according to the present embodiment has a small amount of the unbonded hydrophilic polymer, and the hydrophilic polymer and the primer layer are strongly bonded. There is little peeling of the polymer. Therefore, even if it is continuously used, the desired oil stain removal property can be maintained. In addition, since a surfactant containing a betaine group is contained, in addition to higher detergency, it has higher repetitive detergency. The reason is considered as follows. First, it is understood that the soil removal mechanism is caused by the hydrophilic polymer sucking water and then lifting the soil. Under such a mechanism, it is considered that the addition of the surfactant softens the hydrophilic polymer and forms a state in which water is more easily absorbed, resulting in an increase in the cleaning effect. Further, it is understood that the anti-repetitive cleaning effect is because the surfactant has a high affinity with the hydrophilic polymer and thus does not easily flow out.

<Oil stain removal>
The high oil stain removal property can be grasped by measuring hydrophilicity and lipophilicity. That is, when the lipophilicity is high, the oil stain is difficult to peel off from the surface, so the oil stain removal property is low, and when the hydrophilicity is high, water easily enters under the oil stain and the oil stain removal property is high. I can say that. As described above, the cosmetic puff comprising the hydrophilic rubber molded body according to the present embodiment has a hydrophilic polymer bonded in a wide range because the inorganic silicon bond is a network structure (in other words, a large number of bonds). Since it has sufficient hydrophilicity, it has a high oil stain removal property (specifically, a high foundation removal property).

<Flexibility>
The cosmetic puff comprising the hydrophilic rubber molded body according to this embodiment has a very excellent softening effect because it contains a surfactant containing a betaine group.

≪How to use cosmetic puff≫
The cosmetic puff according to the present embodiment can be used for any type with water, without water, or with both water and no water.

≪Preparation of hydrophilic rubber molding≫
According to the following procedures, hydrophilic rubbers according to Examples and Comparative Examples were prepared.
<Example 1>
As a rubber molded body, NBR latex sponge rubber (open cell body) having a size of 50 × 40 mm and a thickness of 8 mm is prepared, and 1.00 mass of primer A (aqueous aminosilane, KBP-90, manufactured by Shin-Etsu Chemical Co., Ltd.) using water as a solvent. A carboxybetaine group-containing hydrophilic polymer A having a terminal silanol group (LAMBIC-500WP, weight average molecular weight of about 300,000) was adjusted to a concentration of 10.00% by mass to a primer agent having a% concentration. An equal amount of a hydrophilizing agent (diluent is ion-exchanged water) was mixed and impregnated in the latex sponge rubber, and lightly squeezed in the liquid so that the gas inside the latex sponge rubber was released. Thereafter, the latex sponge rubber was quickly taken out from the impregnating solution and subjected to centrifugal dehydration (about 890 G × 3 minutes). And it was made to react at 80 degreeC for 1 hour (hydrophilization process). As a result, the silanol group of the hydrophilic polymer A and the primer layer surface formed on the surface of the latex sponge rubber cause a silane coupling reaction, and the hydrophilic rubber molded body in which the hydrophilic polymer A is bonded to the primer layer. Got. Thereafter, the hydrophilic rubber molded body was impregnated with a lauryl betaine aqueous solution (10 mass% concentration), and lightly squeezed in the liquid so that the gas inside the hydrophilic rubber molded body escaped (about 1 minute). Then, the said hydrophilic rubber molded object was taken out from the impregnation liquid rapidly, and spin-dry | dehydrated (about 890G * 3 minutes). And it was made to dry at 80 degreeC for 1 hour, and the puff which concerns on Example 1 was obtained.
<Example 2>
Except that the aqueous lauryl betaine solution was replaced with 2-alkyl-N-carboxymethyl-N-hydroxyetherimidazolinium betaine (natural coconut oil: a mixture of saturated and unsaturated fatty acids having 8 to 18 carbon atoms), Examples 1 was used to obtain a puff according to Example 2.
<Example 3>
As a rubber molded body, NBR latex sponge rubber (open cell body) having a size of 50 × 40 mm and a thickness of 8 mm is prepared, and primer A (aqueous aminosilane, KBP-90, manufactured by Shin-Etsu Chemical Co., Ltd.) with water as a solvent is 1% by mass The primer sponge was impregnated with the latex sponge rubber (surface treatment step). Thereafter, the latex sponge rubber was taken out and centrifuged at 2000 rpm for 1 minute in a centrifuge to remove excess primer, and then a betaine group-containing hydrophilic polymer A having terminal silanol groups (Osaka Organic Chemical Co., Ltd.). Manufactured by LAMBIC-500WP, weight average molecular weight 15000) adjusted to a concentration of 10% by mass with a hydrophilic treatment agent (diluent is ion-exchanged water) impregnated with the latex sponge rubber and allowed to react at 80 ° C. for 1 hour ( Hydrophilization process). A silanol group of the hydrophilic polymer A and the surface of the primer layer formed on the surface of the latex sponge rubber cause a silane coupling reaction, and a hydrophilic rubber molded body in which the hydrophilic polymer A is bonded to the primer layer is obtained. . Thereafter, the hydrophilic rubber molded body was impregnated with a lauryl betaine aqueous solution (10 mass% concentration), and lightly squeezed in the liquid so that the gas inside the hydrophilic rubber molded body escaped (about 1 minute). Then, the said hydrophilic rubber molded object was taken out from the impregnation liquid rapidly, and spin-dry | dehydrated (about 890G * 3 minutes). And it was made to dry at 80 degreeC for 1 hour, and the puff which concerns on Example 3 was obtained.
<Example 4>
A puff according to Example 4 was obtained in the same manner as in Example 3, except that the aqueous lauryl betaine solution was replaced with 2-alkyl-N-carboxymethyl-N-hydroxyetherimidazolinium betaine.
<Example 5>
A puff according to Example 5 was obtained in the same manner as in Example 4 except that Primer B (polysilazane (Aquamica NL120A, manufactured by AZ Electronic Materials)) using dibutyl ether as a solvent was used instead of Primer A. .
<Example 6>
A puff according to Example 6 was obtained in the same manner as in Example 5, except that the aqueous lauryl betaine solution was replaced with 2-alkyl-N-carboxymethyl-N-hydroxyetherimidazolinium betaine.
<Comparative Example 1>
An untreated rubber molded body, that is, an NBR latex sponge rubber (open cell body) having a size of 50 × 40 mm and a thickness of 8 mm was used as the puff according to Comparative Example 1.
<Comparative example 2>
A puff according to Comparative Example 2 was obtained by the same method as in Example 1 except that it was not treated with a surfactant containing a betaine group.
<Comparative Example 3>
A puff according to Comparative Example 3 was obtained by the same method as in Example 1 except that glycerin was used in place of the surfactant containing a betaine group as a plasticizer.
<Comparative example 4>
A puff according to Comparative Example 4 was obtained in the same manner as in Example 1 except that 1,2-hexanediol was used in place of the surfactant containing a betaine group as a plasticizer.

≪Evaluation test≫
Next, an evaluation test was performed using the prepared hydrophilic rubber molded bodies according to Examples and Comparative Examples.
<Evaluation 1> Swelling rate Based on Formula (1), a swelling rate is calculated | required from the volume before being immersed in water, and the volume change after immersion. The amount of water is an excessive amount with respect to the test piece, the whole is immersed, and the water is impregnated and impregnated with water.
(Formula 1)
<Evaluation 2> Initial stain removal property The YI value (JIS K7373) of the puff before the test is measured with a spectroscopic hardness meter (X: initial YI value). Apply 0.02 g of foundation to the treated puff. Rinse with tap water for 3 minutes. After drying at 80 ° C. for 1 hour, the YI value is measured with a spectroscopic hardness meter (Y: YI value after a cleaning test). (Y-X) × 100 (%) was defined as the initial stain removal property (rate). The smaller the value, the more dirty.
<Evaluation 3> Repeated dirt removal property The puff to be evaluated is washed with hot water of 40 ° C. for 3 minutes. Dry at 80 ° C. for 1 hour. Repeat washing and drying with hot water (40 ° C) 10 times. After repeating 10 times, the YI value of the puff is measured with a spectroscopic hardness meter (A: initial YI value). Next, 0.02 g of foundation is applied, and the YI value is measured with a spectrophotometer (B: YI value after application of foundation). Next, rinse with tap water for 3 minutes. After drying at 80 ° C. for 1 hour, the YI value is measured with a spectroscopic hardness meter (C: YI value after cleaning test). Here, the repeated dirt removal property (rate) is calculated based on the equation (2). The higher the soil removal rate, the better the repeatability.
(Formula 2)
<Evaluation 4> Hardness The puff was measured in the thickness direction with an Asker F hardness meter. Here, on the basis of the F hardness of the untreated product, an increase in the value of the F hardness meter is 5 or less, which is good feeling, preferably 3 or less, more preferably 2 or less.
<Evaluation 5> Feel Determined according to JIS K 6400-2. Specifically, when the stress at the time of compression of 5 to 10% is compared with the compressive stress, an evaluation close to the touch evaluation of the touch felt by human beings can be obtained. The untreated product is the compression stress of a general puff, but if the value is slightly higher than this, it feels slightly hard (△), and if it is slightly higher, it is slightly harder (○). If it is the same or lower, it is evaluated as a soft touch (◎).

Table 1 shows the results. From Table 1, it can be seen that the puff according to the example has a low swelling rate and a high repeated soiling resistance as compared with the puff according to the comparative example. Moreover, FIG. 3 is the figure which showed the relationship of the stroke (distortion) with respect to the test force of the cosmetic puff concerning an Example and a comparative example (based on JIS6400-2E method). In the figure, the dashed line is Example 1, the dotted line is Comparative Example 1, and the solid line is Comparative Example 2. From the figure, it can be seen that Example 1 has the same degree of flexibility as the untreated product (Comparative Example 1). Although not shown, the same behavior was exhibited with respect to other examples.

Claims (9)

At least a part of the surface of the rubber foam is dissolved in water, water glass, alkoxysilanes or their partial hydrolysates or partial hydrolytic condensate, silicone, nitrogenous silicone resin, a nitrogen-containing silane coupling agent or their partial hydrolyzate by treatment with one or more components selected from the group consisting of inorganic silicon network having a hydroxyl group on the surface, a siloxane binding, represented by Si-O-Si as a scaffold A surface treatment step for forming a primer layer comprising a compound;
Comprises a hydrophilic polymer having a betaine group (meth) acrylic acid ester to at least a portion, a hydrophilic polymer which is soluble in water, and hydrophilizing step of binding to the surface of the primer layer by a silane coupling reaction,
Including a surfactant containing a carboxybetaine group in the rubber foam ,
A method for producing a cosmetic puff comprising a hydrophilic rubber molding, wherein both the surface treatment step and the hydrophilization step are performed in one step.   By treating at least a part of the surface of the rubber foam with one or more components selected from the group consisting of silazane or a partial hydrolyzate thereof, the surface has a hydroxyl group and is represented by Si—NH—Si. A surface treatment step of forming a primer layer composed of an inorganic silicon compound having a network structure having a silazane bond as a skeleton;
  A hydrophilic step in which a hydrophilic polymer containing at least part of a hydrophilic polymer having a (meth) acrylic acid ester containing a betaine group is bonded to the surface of the primer layer by a silane coupling reaction;
  Adding a surfactant containing a carboxybetaine group to the rubber foam;
Including
  A method for producing a cosmetic puff comprising a hydrophilic rubber molding, wherein the surface treatment step and the hydrophilization step are performed in two steps in the order. In the hydrophilization step, as the hydrophilic polymer, a hydrolyzable silyl group introduced into at least one end of the main chain of the hydrophilic polymer is used, and after hydrolyzing the hydrolyzable silyl group, the hydrophilic polymer The manufacturing method of Claim 1 or 2 which is the process of making it bond to the said surface by carrying out dehydration condensation of the functional polymer with the said hydroxyl group of the said primer layer by silane coupling reaction. The manufacturing method according to any one of claims 1 to 3 , wherein the betaine group is a carboxybetaine group. The manufacturing method according to any one of claims 1 to 4 , wherein the hydrophilization step is a step performed using, as the hydrophilic polymer, a hydrophilic polymer that can be bonded to the primer layer only at the end of the main chain. . The manufacturing method according to any one of claims 1 to 5 , wherein the hydrophilic polymer has a weight average molecular weight of 300 to 500,000. The rubber molded product is foamed, method of any one of claims 1-6. The manufacturing method according to claim 7 , wherein the foam has open cells. The manufacturing method according to any one of claims 1 to 8 , wherein the rubber molded body is NBR.