JPS6111603B2 - - Google Patents

Abstract

PURPOSE:A tacky depilatory sheet suitable for easy handling, removing hair from their roots, comprising a specific thermoplastic elastomer, tackifying resin, butyl rubber and liquid polymer as constituent ingredients. CONSTITUTION:A tacky depilatory sheet comprising a thermoplastic elastomer having a tensile strength of 10kg/cm<2> at least and a melt index not more than 200, a tackifying resin having a softening point not higher than 180 deg.C, butyl rubber, and a liquid polymer miscible with the three above-mentioned ingredients. A styrene- isoprene-styrene-copolymer with styrene content of 5-45wt%, etc. may be cited as the elastomer. A uniformly dispersed mixture of the above-mentioned ingredients is formed into a film or sheet to give the tacky depilatory sheet, which is brought into contact with the dried skin surface tightly and stripped off forcedly so that hair is removed with ease without leaving a pressure-sensitive adhesive on the skin.

Description

[Detailed description of the invention]

The present invention relates to an adhesive hair removal sheet. As conventional hair removal materials, there are known wax types which are solid at room temperature and which forcefully remove hair from the skin surface, and cream types whose main ingredient is a hair removal agent such as thioglycolate. Before use, wax type products are heated in a container to form a soft cream, and then applied directly to the skin surface from which hair is to be removed, or after solidification, after cutting the hair short and applying it to a thickness of approximately 2 to 4 mm. It is used to forcibly remove the coating and physically remove hair, including the hair roots. However, this type has the advantage that hair does not grow for a long time,
On the other hand, it has many drawbacks such as: (b) It takes time and effort to heat it in a container. (b) Since the strength of the coating film is weak, it is necessary to apply it thickly, which is uneconomical. (c) It is difficult to form a coating film of uniform thickness depending on the hair removal area. (d) It may irritate the skin because it is difficult to measure the melting temperature. (e) Since many natural products are used, there are many variations in properties. Cream-type products have the advantage that hair removal is easy because they use a depilatory agent, but they do not remove the hair roots, so they have to be used every 2 to 3 days, which is a hassle. Adhesive type products are also known, but they have the drawbacks that the hair removal rate varies due to changes in outside temperature conditions and that they cannot be reused. The present invention provides a novel adhesive depilatory sheet that solves the drawbacks of the prior art, and its gist is that it is a thermoplastic sheet having a tensile strength of at least 10 Kg/cm ² and a melt index of 200 or less. It has good adhesion at room temperature and has four essential components: an elastomer, a tackifying resin with a softening point of 180°C or less, butyl rubber, and a liquid polymer that is compatible with each of these three components. The purpose is to form an adhesive hair removal sheet. The adhesive hair removal sheet of the present invention is convenient in use in that hair can be removed from the hair root by being brought into close contact with a pre-dried skin surface and then forcibly peeled off, as explained below. It has various characteristics such as: The thermoplastic elastomer used in the present invention is
It is used to improve the physical strength of the hair removal sheet of the present invention and to resolve variations in properties, and desirably, even if the proportion (weight ratio) in the total components is 30% or less, it is sufficient. High molecular weight polymers are used which can achieve the above objectives. High molecular weight polymers capable of achieving the above objectives are thermoplastic polymers having a tensile strength of at least 10 Kg/cm ² and a melt index of 200 or less, typically with a styrene content. 5 to 45% by weight of styrene-isoprene-styrene or styrene-butadiene-styrene block copolymer. Other thermoplastic elastomers that can be used include ethylene-vinyl acetate copolymers, ethylene-vinyl acetate copolymers,
These include acrylic acid copolymers and trans isoprene. Tensile strength of thermoplastic elastomer (JIS
If C2336) is less than 10 Kg/cm ² , the exfoliating sheet must be made thin in order to closely follow the shape of the skin surface, and when it is adhered to the skin surface and peeled off, it is unfavorable because it is likely to break. In addition, if the melt index is 200 or more, the fluidity when heated and melted is too high, resulting in uneven thickness of the hair removal sheet, unnecessary adhesion to the skin surface, and adhesive loss during storage. This is undesirable because it may flow or protrude from the support. The tackifying resin used in the present invention is mainly used to improve adhesion to hair, and includes natural resins such as gum rosin, uds rosin, and dammar, polymerized rosin, partially hydrogenated rosin, and glyceryl ester rosin. , modified rosins such as bentaerythrite ester rosin and their derivatives, terpene resins, petroleum resins,
Examples include xylene resins. However, it is necessary to select and use such resins with a softening point of 180° C. or lower; if the softening point is higher than this, the resulting adhesive hair removal sheet has the disadvantage of poor low-temperature adhesion to the skin, which is not preferable. . However, when using the above-mentioned resins, the combination of resins that are solid (or semi-solid) at room temperature and resins that are liquid at room temperature is important to ensure that the adhesive hair removal sheet has appropriate adhesion and the atmospheric temperature range during use. This is preferable because it can expand the The ratio (weight ratio) of solid resins and liquid resins is 1:
A range of 0.1 to 1.5 is preferable from the viewpoint of obtaining the above characteristics. The butyl rubber used in the present invention is mainly used to control the surface tackiness of the adhesive hair removal sheet, and has an average molecular weight of 200,000 to 600,000, an unsaturated content of 1 to 5 mol%, and a Mooney viscosity of ML _{(1+8 )} 100℃25
~60 are selected. Further, the liquid polymer used in the present invention is used mainly for the purpose of imparting flexibility to the adhesive hair removal sheet at low temperatures and improving the adhesion to the skin surface when it is adhered to the skin surface.
Compatible solubility is used for each of the components, for example, an average molecular weight of 500 to 1500, a kinematic viscosity (210
〓) Polybutene of 120 to 2150 cst is preferably used. For example, liquid isoprene rubber, liquid tackifying resins, etc. can also be used. The adhesive hair removal sheet of the present invention is composed of these four components as essential components: a thermoplastic elastomer, a tackifying resin, a butyl gore, and a liquid polymer, and optionally a colorant, a filler, and an antioxidant. Appropriate amounts of compounding agents such as agents, stabilizers, local anesthetics, and fragrances can be added. The above-mentioned four essential components are thermoplastic elastomer;
The tackifying resin, butyl rubber, and liquid polymer are generally added in a range of 50 to 600 parts by weight of resin, 2 to 30 parts by weight of butyl rubber, and 30 to 200 parts by weight of liquid polymer per 100 parts by weight of thermoplastic elastomer. However, the practical range is 100 to 300 parts by weight of the resin, 5 to 12 parts by weight of the butyl rubber, and 70 to 120 parts by weight of the liquid polymer. The uniformly dispersed mixture designed in this way is
Using known sheet-forming or film-forming means such as extrusion, rolling, and casting, a film is formed to a thickness of about 0.05 to 1.5 mm to obtain an adhesive hair removal sheet. In addition, the sheet has thin nonwoven fabric, cloth, etc. between its layers or on one surface.
A film-like material such as paper or plastic film may be interposed or fixed as a reinforcing support, and a release paper or release film may be provided on the adhesive surface. In addition to being easy to handle, the adhesive hair removal sheet of the present invention has a uniform thickness, so there is little variation in properties, and it also has the characteristics that no adhesive remains on the skin surface, and there is little change in hair removal rate due to changes in outside temperature. have Next, examples of the present invention will be shown. "Middle of the text" indicates parts by weight. Examples Samples Nos. 1 to 4 were prepared using Formulation Examples 1 to 4 below, and a hair removal test was conducted on adult men and women. The test results for its properties are shown in Table 1. The sample was prepared by first mixing the thermoplastic elastomer, polybutene, butyl rubber, and stabilizer in the formulation example, melting and stirring at 150°C for 60 minutes, then adding the tackifying resin and melting and stirring at 150°C for another 20 minutes. Afterwards, a fragrance (formulation example 4 only) is added and stirred for 1 minute, and the resulting molten mixture is spread on a polyester film to a thickness of about 0.3 mm. Formulation example 1 S-I-S 30 parts Gum rosin 60 IIR 3 Polybutene 23 Stabilizer 1 Formulation example 2 S-I-S 40 parts Gum rosin 60 IIR 3 Liquid isoprene 25 Stabilizer 1 Formulation example 3 SBS 20 parts Petroleum-based resin 60〃 Polybutene 30〃 IIR 3〃 Mixing example 4 S-I-S 30 parts Petroleum-based resin 60〃 Pributene 23〃 IIR 3〃 Stabilizer 1〃 Fragrance 0.2〃 The above combination examples 1 to 4 Indicates the abbreviations used and their properties or structures. S-I-S: Styrene-isoprene-styrene teleblock elastomer ●Average molecular weight 12,50,000 ●Styrene/rubber ratio 14/86 ●Melt index (G conditions) 10g/min ●Solution viscosity (25℃, 25wt% toluene) solution)
1600cps Gum rosin: Chinese gum rosin ●Softening point 95-105℃ ●Grade × IIR: Butyl rubber ●Average molecular weight 350,000 ●Unsaturation degree 2Mol% ●Mooney viscosity ML (1+8min) 100℃45 Polybutene: ●Average molecular weight 1260 ●Kinematic viscosity (210 〓）32000cst. ●Specific gravity (15/4℃) 0.895 Stabilizer: Alkylated bisphenol SBS: Styrene-butadiene-styrene radial teleblock elastomer ●Average molecular weight 150,000 ●Styrene/rubber ratio 30/70 ●Melt index (E condition) 2.4g/min Petroleum resin: Alicyclic saturated hydrocarbon resin ●Average molecular weight 630 ●Softening point 90℃ ●Acid value 0 Fragrance: diasmine oil

[Table] Test method The sample is 5 cm x 13 cm in size, and a 5 cm x 3 cm piece of paper is attached to one end of the sample to form a grip. Next, this sample body is adhered to the test site so that the knob is located in the direction of hair flow, and then the sample is removed by holding the knob and rapidly peeling off in the opposite direction to the direction of hair flow. The hair removal rate was determined by the following formula by examining the hair removed from the test site and the hair remaining in the test site trace. Hair removal rate (%) = Number of hairs removed / (Number of hairs remaining in site marks) + (Number of hairs removed) x 100 As is clear from the above examples, the adhesive hair removal sheet of the present invention has the following properties: It is found that it has a remarkable hair removal effect.

Claims (1)

[Scope of Claims] 1. A thermoplastic elastomer having a tensile strength of at least 10 Kg/cm ² and a melt index of 200 or less, a tackifying resin having a softening point of 180°C or less, butyl rubber, and a combination of these three components. An adhesive hair removal sheet that has good adhesiveness at room temperature and has four essential constituents of liquid polymers that are compatible with each other. 2. A hair removal sheet according to claim 1, in which a reinforcing support is interposed or fixed between the layers or on one surface thereof.