JP2015229760A - Gel elastomer composition and cosmetic gel sheet using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gel elastomer composition less in tack while having moderate hardness, elongation and control release property and a cosmetic gel sheet using the gel elastomer composition.SOLUTION: The gel elastomer composition contains (A1) a styrenic thermoplastic elastomer having a weight average molecular weight of 100,000 or more and less than 180,000 and consisting of a block copolymer of triblock or more and (A2) a styrenic thermoplastic elastomer having a weight average molecular weight of 180,000 or more and 300,000 or less and consisting of a block copolymer of triblock or more with a mass ratio (A1)/(A2)=95/5 to 50/50 and has degree of dispersion of the molecular weight (Mw/Mn) of 1.25 to 1.60. It contains (B) hydrocarbon oil having kinetic viscosity at 37.8°C of 5 to 50 mm/s of 500 to 4800 pts.mass and (C) silicone oil having kinetic viscosity at 25°C of 50 to 200 mm/s of 20 to 60 pts.mass based on 100 pts.mass of the (A) styrenic thermoplastic elastomer mixture.

Description

  The present invention relates to a gel elastomer composition having a moderate hardness, elongation and sustained release, and having a small tack, and a cosmetic gel sheet using the same, and having irregularities such as elbows, knees, and heels The present invention relates to a cosmetic gel sheet used for moisture retention and dry skin countermeasures.

  Conventionally, a gel elastomer obtained by blending an oil agent with a styrene thermoplastic elastomer has been used in various products that require elasticity. For example, shock absorbers for foot care such as insoles and pads for hallux vales, shock absorbers for sports such as knee pads and elbow pads, and pack materials and poultices that use the sustained release of oils, fragrances It is used in various fields such as. Among them, pack materials used as cosmetic products are effective in moisturizing skin and improving dry skin by allowing gel elastomer impregnated with active ingredients to adhere to the skin, so that oils and active ingredients penetrate into the skin. Demonstrate.

  For example, Patent Document 1 discloses a composition in which a styrenic thermoplastic elastomer and a hydrocarbon oil are blended as a gel pack material. Although this composition can be impregnated with a large amount of a cosmetic liquid, has little irritation to the skin, and is excellent in sustained release of active ingredients, the styrenic thermoplastic elastomer is a low molecular weight styrene type. Since the composition contains a thermoplastic elastomer or a diblock copolymer, the composition is insufficient in hardness and elongation, and is not suitable for a sheet used for an uneven portion such as a knee or an elbow.

  On the other hand, Patent Document 2 discloses a gel elastomer composition exhibiting delayed elasticity with respect to gel hardness and elongation. This composition comprises a high molecular triblock styrene thermoplastic elastomer having a number average molecular weight of 130,000 or more, a low molecular triblock styrene thermoplastic elastomer having a number average molecular weight of 100,000 or less, and a softening agent. It is a gel elastomer, and the high molecular weight triblock styrene elastomer absorbs and retains a large amount of softening agent, while ensuring the flexibility of the composition, it is delayed by containing a low molecular weight triblock styrene elastomer. Although elasticity is imparted, such a composition is still insufficient in terms of tack and release properties on the gel surface.

JP 2012-012374 A JP 2001-151980 A

  An object of the present invention is to provide a gel elastomer composition having moderate hardness, elongation, and sustained release properties such as an oil agent and having less tack, and a cosmetic gel sheet using the gel elastomer composition. To do.

  The present inventors blended and specified two types of styrene thermoplastic elastomers: a low molecular weight styrene thermoplastic elastomer having a specific molecular weight and a high molecular weight styrene thermoplastic elastomer having a specific molecular weight. The present invention was completed by blending a hydrocarbon oil having a viscosity in a range and a silicone oil having a viscosity in a specific range.

That is, according to the first invention of the present invention, the styrene thermoplastic elastomer (A1) having a weight average molecular weight of 100,000 or more and less than 180,000 and comprising a block copolymer of triblock or more, and the weight average molecular weight. Is a styrene-based thermoplastic elastomer (A2) composed of a block copolymer having a triblock or more and a mass ratio of (A1) / (A2) = 95/5 to 50/50 The kinematic viscosity at 37.8 ° C. is 5 to 50 mm ² with respect to 100 parts by mass of the styrene-based thermoplastic elastomer mixture (A) having a molecular weight dispersity (Mw / Mn) of 1.25 to 1.60. a / s a hydrocarbon oil (B) from 500 to 4800 parts by mass, kinematic viscosity at 25 ° C. is to contain a silicone oil (C) 20 to 60 parts by weight is 50 to 200 mm ² / s , Gel elastomer composition is provided.

  According to the second invention of the present invention, a cosmetic gel sheet using the gel elastomer composition of the first invention is provided.

  The gel elastomer composition of the present invention is a gel elastomer composition with a small tack while having moderate hardness, elongation, and sustained release properties such as oil. Moreover, the cosmetic gel sheet of the present invention using the gel elastomer can be used for moisturizing a portion having irregularities such as elbows, knees, and heels, and measures against dry skin.

  Hereinafter, the present invention will be described in detail.

  The styrenic thermoplastic elastomer (A1, A2) used in the present invention is a triblock or higher block copolymer containing a polystyrene hard segment and a soft segment, preferably a block component comprising a styrene hard segment is a molecular chain. It is a block copolymer having two or more therein, and more preferably a block copolymer in which the block components at least at both ends in the molecular chain are block components composed of the styrene hard segment. The polystyrene hard segment is not particularly limited, and examples thereof include polystyrene, poly (α-methylstyrene), poly (o-methylstyrene), poly (m-methylstyrene), and poly (p-methylstyrene). Examples thereof include polystyrene polymers. The soft segment is not particularly limited, and examples thereof include polyolefin polymers such as polyethylene, polypropylene, polybutylene, polybutadiene, and polyisoprene.

  The copolymer used as the styrenic thermoplastic elastomer (A1, A2) is not particularly limited as long as it is a triblock or higher styrene block copolymer. For example, styrene-butadiene-styrene block copolymer (SBS) ), Styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-isoprene-butylene-styrene block copolymer (SIBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene -A styrene block copolymer (SEPS), a styrene-ethylene-ethylene-propylene styrene block copolymer (SEEPS), and a combination of two or more of these. Among these, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS) in terms of the hardness and elongation of the gel after being formed into a sheet or the like. And styrene-ethylene / ethylene-propylene-styrene block copolymer (SEEPS) is preferred. When a diblock copolymer is used as the styrenic thermoplastic elastomer (A1, A2), the styrenic hard segment interaction (π-π stacking) is weakened, so the gel has sufficient hardness and elongation. There is a possibility that it cannot be obtained. The styrenic thermoplastic elastomer has a network-like network structure formed by a plurality of aggregation domains formed by the interaction of the styrene hard segments and an olefinic soft segment connecting the plurality of aggregation domains. Therefore, it is considered that the function as an elastic body is expressed. Moreover, such a network-like network structure is considered to have a function of holding an oil agent (that is, a hydrocarbon oil (B) and a silicone oil (C)), which will be described later, while appropriately releasing it.

  The block copolymer is preferably 10 to 50% by mass of a styrene block component and about 50 to 90% by mass of an olefinic block component, more preferably 15 to 40% by mass of styrene block component and 60 to 85% by mass. % Olefinic block component, particularly preferably 18 to 35% by mass of styrenic block component and 65 to 82% by mass of olefinic block component. When the amount of the styrenic block component is less than 10% by mass, the amount of the styrenic block component that forms the agglomeration domain decreases, so that the styrenic thermoplastic elastomer is difficult to form the network network structure described above. . On the other hand, when the amount of the styrenic block component exceeds 50% by mass, the amount of the olefinic block component that holds the oil agent or the like decreases, so the amount of the oil agent or the like that can be held decreases, and the styrene hard segment Since the amount of aggregation domains formed by the process increases, the gel after molding may become hard.

  In the present invention, the styrene-based thermoplastic elastomer mixture (A) is composed of a mixture of two types of styrene-based thermoplastic elastomers (A1, A2) having different weight average molecular weights.

  One of the two types of styrenic thermoplastic elastomers (A1, A2) (hereinafter referred to as “low molecular weight styrenic thermoplastic elastomer (A1)”). The weight average molecular weight is in the range of 100,000 to less than 180,000, preferably in the range of 100,000 to 150,000. When the weight average molecular weight is less than 100,000, the hardness and elongation of the gel are lowered. The other styrene thermoplastic elastomer (A2) (hereinafter sometimes referred to as “high molecular weight styrene thermoplastic elastomer (A2)”) has a weight average molecular weight in the range of 180,000 to 300,000. Preferably, it is in the range of 220,000 to 280,000. When this weight average molecular weight exceeds 300,000, tackiness tends to occur on the surface of the gel.

  The styrenic thermoplastic elastomer mixture (A) has a dispersity (that is, a ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn)) within a range of 1.25 to 1.60. Yes, preferably in the range of 1.35 to 1.55. If the degree of dispersion is less than 1.25, the gel elastomer composition has the same physical properties as when a single styrenic thermoplastic elastomer is used. On the other hand, if the dispersity exceeds 1.60, the gel after molding becomes heterogeneous due to the difference in cooling and solidifying time of the two types of styrene-based thermoplastic elastomers (A1, A2). The physical properties such as decrease.

  The weight average molecular weight (Mw) of the two types of styrenic thermoplastic elastomers (A1, A2) and the styrenic thermoplastic elastomer mixture (A), and the degree of dispersion of the styrenic thermoplastic elastomer mixture (A) (Mw / Mn) can be determined by polystyrene conversion by GPC measurement under the following conditions using tetrahydrofuran (THF) as a mobile phase.

[GPC measurement conditions]
Apparatus: GPC-8220 (manufactured by Tosoh Corporation)
Column: Shodex LF-804 (manufactured by Showa Denko KK)
Temperature: 40 ° C
Solvent: THF
Flow rate: 1.0 ml / min
Sample concentration: 0.05-0.6% by mass
Injection volume: 0.1ml

  As described above, in the present invention, a mixture of two types of styrene thermoplastic elastomers (A1, A2) having different weight average molecular weights is used, and the blending amount thereof is the same as that of the low molecular weight styrene thermoplastic elastomer (A1). The mass ratio of the high molecular weight styrene-based thermoplastic elastomer (A2) is in the range of (A1) / (A2) = 95 / 5-50 / 50, preferably 90 / 10-60 / 40, more preferably 80/20 to 70/30. When the blending ratio of the low molecular weight styrenic thermoplastic elastomer (A1) exceeds 95 in the mass ratio, the hardness and elongation of the gel become insufficient, and when the blending ratio is less than 50, the surface of the gel Tack is likely to occur.

The gel elastomer composition of the present invention further includes a hydrocarbon oil (B) having a kinematic viscosity at 37.8 ° C. of 5 to 50 mm ² / s. The hydrocarbon oil (B) used in the present invention is not particularly limited as long as it is a compound composed of carbon and hydrogen, and has a saturated or unsaturated bond even if it has a linear, branched or cyclic structure. May be. Examples of the hydrocarbon oil (B) include olefinic hydrocarbons (alkenes containing one double bond), paraffinic hydrocarbons (alkanes containing neither a double bond nor a triple bond), or acetylene hydrocarbons (triple). Alkyne having one bond), hydrocarbons having two or more double bonds and / or triple bonds, and cyclic hydrocarbons such as aromatic hydrocarbons and alicyclic hydrocarbons. More specifically, examples include hydrogenated polyisobutene, liquid paraffin, squalane, squalene, etc.In particular, hydrogenated polyisobutene does not cause tackiness in the gel after molding, nor does it cause stickiness due to the slowly released oil agent, It can be preferably used.

Said hydrocarbon oil (B) is in the range kinematic viscosity at 37.8 ° C. is 5 to 50 mm ² / s, preferably in the range of 10 to 30 mm ² / s, more preferably 10 to 20 mm ² / s Is within the range. If the kinematic viscosity is less than 5 mm ² / s, the hydrocarbon oil (B) is likely to be volatilized during the production of the gel elastomer composition, so that the physical properties of the gel elastomer composition may vary. On the other hand, when this kinematic viscosity exceeds 50 mm ² / s, the gel after molding becomes hard and tackiness is likely to occur. The kinematic viscosity of the hydrocarbon oil (B) is measured at a test temperature of 37.8 ° C. using a Cannon Fenceke reverse flow viscometer according to “5. Kinematic viscosity test method” of JIS K 2283: 2000. Can be obtained.

  The blending amount of the hydrocarbon oil (B) is in the range of 500 to 4800 parts by weight, preferably in the range of 800 to 3000 parts by weight, with respect to 100 parts by weight of the styrenic thermoplastic elastomer mixture (A). More preferably, it exists in the range of 1000-1500 mass parts. When this blending amount is less than 500 parts by mass, the gel after molding becomes hard and the elongation also decreases. On the other hand, when this compounding quantity exceeds 4800 mass parts, the said gel will become too soft and it will become difficult to maintain the shape after shaping | molding.

The gel elastomer composition of the present invention further includes a silicone oil (C) having a kinematic viscosity at 25 ° C. of 50 to 200 mm ² / s. The silicone oil (C) used in the present invention is not particularly limited as long as it is a silicone oil, and any known silicone oil can be used. Examples of the silicone oil (C) include diorganopolysiloxanes such as dimethylpolysiloxane and methylphenylpolysiloxane, and cyclic siloxanes such as cyclopentasiloxane. In particular, dimethylpolysiloxane is preferably used because it can impart an appropriate sustained release property of an oil agent (that is, the hydrocarbon oil (B) and the silicone oil (C)) to the gel elastomer composition. it can.

The silicone oil (C) is in the range kinematic viscosity at 25 ° C. of 50 to 200 mm ² / s, preferably in the range of 70~150mm ² / s, more preferably in the range of 80 to 120 mm ² / s It is. If the kinematic viscosity is less than 50 mm ² / s, the silicone oil (C) is likely to be volatilized during the production of the gel elastomer composition, so that the physical properties of the gel elastomer composition may vary. On the other hand, when the kinematic viscosity exceeds 200 mm ² / s, the amount of sustained release of the oil agent is reduced and tackiness tends to occur. The kinematic viscosity of the silicone oil (C) is also measured at a test temperature of 25 ° C. using a Canon Fenceke reverse flow viscometer according to “5. Kinematic viscosity test method” of JIS K 2283: 2000. Can be obtained.

  The amount of the silicone oil (C) is in the range of 20 to 60 parts by mass, preferably in the range of 30 to 50 parts by mass, with respect to 100 parts by mass of the styrenic thermoplastic elastomer mixture (A). . When the blending amount is less than 20 parts by mass, the sustained release amount of the active ingredient is decreased. On the other hand, when it exceeds 60 parts by mass, the sustained release amount is excessively increased and the surface of the gel becomes oily.

  The gel elastomer composition of the present invention includes a stabilizer, an antioxidant, a light stabilizer, a colorant, a pigment (for example, titanium oxide, zinc oxide, etc.), a fragrance, and an inorganic powder as long as the object of the present invention is not impaired. Any additive such as (for example, alumina, talc, mica, calcium carbonate, clay, etc.), organic powder (eg, PE, PP, silicone resin powder, etc.) can be included.

  The gel elastomer composition of the present invention can be produced by mixing the various blending components described above using any known mixing means. For example, the gel elastomer composition of the present invention can be produced by supplying the above-mentioned various blending components simultaneously or in any order into a mixing apparatus and melt-mixing in the mixing apparatus. There is no particular limitation on the means for melting and mixing, and any known means can be adopted. For example, a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, various kneaders, a mixing kettle, etc. The means using is mentioned.

  The gel elastomer composition of the present invention has moderate hardness and elongation, and also has a sustained release property, so that any molding such as extrusion molding, injection molding, dipping molding or the like can be performed while suppressing adhesion to a molding apparatus. It can be shaped by a method. Furthermore, since the gel elastomer composition of the present invention contains more low molecular weight styrenic thermoplastic elastomer than high molecular weight styrenic thermoplastic elastomer, it has moderate fluidity even at a temperature of around 100 ° C. Therefore, it is possible to easily perform lamination or integral molding by coating or the like on various substrates such as paper, cloth, olefin resin, and PET resin.

  Since the gel elastomer composition of the present invention has appropriate hardness, elongation and sustained release properties, it can be used for cosmetic gel sheets such as packs, poultices or fragrances utilizing these properties. In addition, facial treatment doll face (skin, etc.), health care related products, insoles of shoes, shock absorbers for foot care to relieve pain caused by hallux valgus and wound nails, massage tools, etc. Head parts, toy parts, miscellaneous goods, medical shock absorbers to prevent rubbing between the prosthetic leg and the skin, cleaning supplies that apply oils while adsorbing dust and debris from daily life such as floors It can be used for various purposes.

  The cosmetic gel sheet using the gel elastomer composition of the present invention can be widely used for cosmetic applications, but it is easy to dry on elbows, knees, heels and the like, and is well applied to uneven skin. Therefore, it is particularly useful for moisturizing such sites and improving dry skin. The method of using the cosmetic gel sheet of the present invention is not particularly limited, but for example, a moisturizing cream is applied in advance to a site to be applied such as an elbow, knee, or heel, and then the cosmetic gel sheet is applied on the moisturizing cream. The permeability of the component can be further increased. In addition, by incorporating a cosmetic component such as a cosmetic liquid in the gel elastomer composition of the present invention, the cosmetic component and the oil agent are gradually released, and excellent skin care can be performed.

  EXAMPLES Hereinafter, although an Example and a comparative example are illustrated and this invention is demonstrated further more concretely, this invention is not limited only to an Example.

  In producing the gel elastomer compositions of Examples and Comparative Examples of the present invention, the following commercially available products were used as various blending components.

1) Styrenic thermoplastic elastomer (A1, A2)
a) Low molecular weight styrenic thermoplastic elastomer (A1)
Clayton G1652 (styrene-ethylene-butylene-styrene block copolymer (SEBS) having a Mw of 80,000, manufactured by Kraton Polymer Co., Ltd.)
Septon 4033 (styrene-ethylene / ethylene-propylene-styrene block copolymer (SEEPS) having a Mw of 100,000, manufactured by Kuraray Co., Ltd.)
・ Septon 8004 (styrene-ethylene-butylene-styrene block copolymer (SEBS) having a Mw of 110,000, manufactured by Kuraray Co., Ltd.)

b) High molecular weight styrenic thermoplastic elastomer (A2)
Clayton G1654 (styrene-ethylene-butylene-styrene block copolymer (SEBS) having a Mw of 200,000, manufactured by Kraton Polymer Co., Ltd.)
Septon 4055 (styrene-ethylene / ethylene-propylene-styrene block copolymer (SEEPS) with Mw of 250,000, manufactured by Kuraray Co., Ltd.)
-Septon 2005 (styrene-ethylene-propylene-styrene block copolymer (SEPS) having a Mw of 260,000, manufactured by Kuraray Co., Ltd.)
Septon 2006 (Styrene-ethylene-propylene-styrene block copolymer (SEPS) with a Mw of 280,000, manufactured by Kuraray Co., Ltd.)

2) Oil
a) Hydrocarbon oil (B)
Pearl Ream EX (hydrogenated polyisobutene with a kinematic viscosity at 37.8 ° C. of 10 mm ² / s, manufactured by NOF Corporation)
・ Pearl Ream 6 (hydrogenated polyisobutene having a kinematic viscosity at 37.8 ° C. of 20 mm ² / s, manufactured by NOF Corporation)
・ Super Squalane (Squalane with a kinematic viscosity of 18 mm ² / s at 37.8 ° C, manufactured by SQUATECH Co., Ltd.)
-Moresco White P-200 (liquid paraffin with a kinematic viscosity at 37.8 ° C. of 44 mm ² / s, manufactured by MORESCO)
Liquid paraffin (liquid paraffin with a kinematic viscosity at 37.8 ° C of 75 mm ² / s, manufactured by Kishida Chemical Co., Ltd.)

b) Silicone oil (C)
・ SH200-100cs (dimethylpolysiloxane having a kinematic viscosity at 25 ° C. of 100 mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)
・ SH200-500cs (dimethylpolysiloxane having a kinematic viscosity at 25 ° C. of 500 mm ² / s, manufactured by Toray Dow Corning Co., Ltd.)

[Examples 1-6, Comparative Examples 1-8]
1. Manufacture of gel elastomer composition
The above-mentioned various blending components were charged into a separable flask in the blending amounts shown in Table 1 below, melted and mixed at 140 ° C. for 5 hours while stirring the contents, and then cooled to obtain a gel elastomer composition. The properties of each gel elastomer composition obtained were evaluated by the following various test methods. Table 1 shows the results of various tests and evaluations.

2. Evaluation of gel elastomer composition
(1) Hardness Using the gel elastomer composition obtained as described above, a test piece made of a columnar gel having a diameter of 40 mm and a thickness of 8 mm was produced. This test piece is set on a small desktop tester EzTest (manufactured by Shimadzu Corporation) equipped with a stainless steel compression jig having a diameter of 120 mm, and the test force when the test piece is compressed 4 mm at a speed of 5 mm / min (N) Was measured. The measured value was evaluated according to the following criteria.
2 points: 6N or more, less than 41N 1 point: 41N or more, less than 101N 0 point: less than 6N or 101N or more

(2) Brittleness The test piece after the above hardness evaluation was visually observed, and the state of the test piece was evaluated according to the following criteria.
2 points: not cracked 1 point: slightly cracked 0 point: cracked

(3) Elongation The gel elastomer composition obtained as described above was hot-pressed under the conditions of 120 ° C. and a pressure of 10 kg / cm ² to prepare a gel sheet of 60 mm × 60 mm × 1 mm thickness. It cut and produced the test piece of a strip shape of 20 mm x 60 mm. Pick both ends of the test piece in the longitudinal direction with both thumbs and index fingers using both hands, pull both ends in opposite directions (that is, directions where both ends are separated from each other), and pull the test piece The presence or absence of breakage when 5 cm, 7 cm, and 10 cm were stretched from the length of was observed. In addition, when the test piece broke at hand, it started again. The results observed as described above were evaluated according to the following criteria.
2 points: cut when +10 cm stretched 1 point: cut when +7 cm stretched 0 point: cut when stretched +5 cm

２点： 質量増加率（徐放量）が１.５％以上、９.１％未満
１点： 質量増加率（徐放量）が９.１％以上
０点： 質量増加率（徐放量）が１.５％未満 (4) Sustained release property Using the obtained gel elastomer composition, a test piece made of a columnar gel having a diameter of 40 mm and a thickness of 8 mm was prepared. On this test piece, a commercially available tissue paper (a set of two sheets) whose mass was measured in advance was placed, and a load of 100 g was applied from above the tissue paper and left at room temperature (23 ° C.) for 24 hours. Then, the tissue paper was removed and its mass was measured. Then, from the mass (W ₁ ) measured in advance and the mass (W ₂ ) measured after being left for 24 hours, the mass increase rate of the tissue paper is calculated based on the following formula (1), and the mass increase The rate was evaluated as the sustained release amount according to the following criteria.

2 points: Mass increase rate (sustained release amount) is 1.5% or more and less than 9.1% 1 point: Mass increase rate (sustained release amount) is 9.1% or more 0 point: Mass increase rate (sustained release amount) is 1 Less than 5%

(5) Sensory evaluation The gel elastomer composition obtained as described above was hot-pressed under the conditions of 120 ° C. and a pressure of 10 kg / cm ² to prepare a gel sheet having a thickness of 60 mm × 60 mm × 1 mm, and then the gel sheet Was laminated with a PE non-woven fabric to produce a laminated gel sheet for sensory evaluation. After leaving the laminated gel sheet thus obtained at 23 ° C. overnight, regarding the touch feeling when the surface of the laminated gel sheet was reciprocated 10 times left and right with a finger, “softness” and “wetting and tack” evaluated. In this evaluation, 10 subjects were allowed to touch the laminated gel sheet, and a questionnaire based on the following evaluation criteria was conducted. In addition, the result of the questionnaire was an average score of 10 people.

[soft]
2 points: elastic and soft 1 point: no elasticity but soft or elastic but hard 0 points: no elasticity and hard

[Wettability and tack]
3 points: Fingers are wet and no tack is seen 2 points: Fingers are wet and tack is slightly seen 1 point: Fingers are wet and tack is seen 0 points: Fingers are not wet regardless of the presence or absence of tack

<Comprehensive evaluation>
The total points of the physical property evaluations (1) to (4) and the sensory evaluation (5) were comprehensively evaluated according to the following criteria.
○: The total score is 11.0 points or more and there is no person who gave 0 points in sensory evaluation. Δ: The total score is 11.0 points or more and there were people who gave 0 points in sensory evaluation. The total score is less than 11.0

  As shown in Table 1, the gel elastomer compositions of Examples 1 to 6 showed good results in comprehensive evaluation. In particular, the gel elastomer compositions of Examples 1 to 4 were excellent in all of hardness, elongation and sustained release, and high evaluation results were obtained even in sensory evaluation.

  On the other hand, since the gel elastomer composition of Comparative Example 1 contained only the low molecular weight styrene thermoplastic elastomer (A1) as the styrene thermoplastic elastomer, the gel became hard and brittleness was also observed.

  Since the gel elastomer composition of Comparative Example 2 contained only the high molecular weight styrene thermoplastic elastomer (A2) as the styrene thermoplastic elastomer, the gel elongation was excellent, but the sustained release amount increased, In the evaluation, a satisfactory evaluation was not obtained, for example, tack was seen.

  In the gel elastomer composition of Comparative Example 3, since the blending amount of the hydrocarbon oil (B) was less than 500 parts by mass, the gel became hard, the sustained release amount was small, and wettability was poor in sensory evaluation.

In the gel elastomer composition of Comparative Example 4, since the kinematic viscosity at 37.8 ° C. of the hydrocarbon oil (B) was larger than 50 mm ² / s, the sustained release amount was small, and tack was observed in the sensory evaluation.

  The gel elastomer composition of Comparative Example 5 has a mass ratio of (A1) / (A2) = 95/5 to the low molecular weight styrene thermoplastic elastomer (A1) and the high molecular weight styrene thermoplastic elastomer (A2). Since it was out of the range of 50/50, the sustained release amount was increased, and tack was observed in the sensory evaluation.

  In the gel elastomer composition of Comparative Example 6, the degree of dispersion of the styrenic thermoplastic elastomer mixture (A) was greater than 1.60, and thus the gel elongation was poor and brittleness was also observed.

In the gel elastomer composition of Comparative Example 7, the kinematic viscosity at 25 ° C. of the silicone oil (C) was greater than 200 mm ² / s, so that the sustained release amount was small, and tack was observed in the sensory evaluation.

  Since the gel elastomer composition of Comparative Example 8 did not contain silicone oil (C), the sustained release amount was extremely small, and the wettability was poor in sensory evaluation.

  Below, the aspect of this invention assumed is illustrated.

One aspect (Aspect 1) of the present invention is a styrene-based thermoplastic elastomer (A1) having a weight average molecular weight of 100,000 or more and less than 180,000 and comprising a block copolymer of triblock or more, and a weight average molecular weight of 18 Styrene-based thermoplastic elastomer (A2) composed of a block copolymer of triblock or more and not less than 10,000 to 300,000 in a mass ratio of (A1) / (A2) = 95/5 to 50/50 The kinematic viscosity at 37.8 ° C. is 5 to 50 mm ² / s with respect to 100 parts by mass of the styrene-based thermoplastic elastomer mixture (A) having a molecular weight dispersity (Mw / Mn) of 1.25 to 1.60. a hydrocarbon oil (B) 500-4,800 parts by mass, a kinematic viscosity at 25 ° C. containing a silicone oil (C) 20 to 60 parts by weight is 50 to 200 mm ² / s is, Gerue It is a Sutoma composition.

  In another aspect (Aspect 2) of the present invention, in the gel elastomer composition of Aspect 1, the block copolymer has two or more block components composed of styrenic hard segments in the molecular chain.

  In another aspect (aspect 3) of the present invention, in the gel elastomer composition according to aspect 2, the block components at least at both ends in the molecular chain of the block copolymer are block components composed of the styrenic hard segment. .

  Another aspect (Aspect 4) of the present invention is a cosmetic gel sheet using the gel elastomer composition according to any one of Aspects 1 to 3.

Claims (4)

Styrenic thermoplastic elastomer (A1) having a weight average molecular weight of 100,000 or more and less than 180,000 and comprising a block copolymer of triblock or more, a weight average molecular weight of 180,000 or more and 300,000 or less, and triblock The styrene-based thermoplastic elastomer (A2) comprising the above block copolymer is included at a mass ratio of (A1) / (A2) = 95/5 to 50/50, and the molecular weight dispersity (Mw / Mn) is With respect to 100 parts by mass of the styrene-based thermoplastic elastomer mixture (A) that is 1.25 to 1.60,
A hydrocarbon oil kinematic viscosity of 5~50mm ² / s (B) 500~4800 parts by at 37.8 ° C., silicone oil (C). 20 to a kinematic viscosity of 50 to 200 mm ² / s at 25 ° C. Gel elastomer composition containing 60 mass parts.   The gel elastomer composition according to claim 1, wherein the block copolymer has two or more block components composed of styrenic hard segments in a molecular chain.   The gel elastomer composition according to claim 2, wherein at least both terminal block components in the molecular chain of the block copolymer are block components composed of the styrenic hard segment.   A cosmetic gel sheet using the gel elastomer composition according to any one of claims 1 to 3.