JPH0238667Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is an improvement of cosmetic pencils used for eyebrows, eye shadows, lipsticks, etc., especially cosmetic resin pencils in which the periphery of the cosmetic core material is coated with resin. It is related to.

《Prior Art》 Conventionally, commercially available cosmetic pencils are generally made of a core material covered with wood.
Not only is the manufacturing process complicated and time-consuming, but due to the recent rise in the price of wood, it has become difficult to obtain high-quality wood at a low price, so a resin pencil using synthetic resin as a covering or reinforcing material was developed. It has reached this point.

Of course, this type of resin pencil requires a certain degree of strength to prevent breakage of the core material, but at the same time, it is also required to have excellent machinability when cutting out the core material. Therefore, it has been proposed to make the coating material porous by adding a foaming agent to the synthetic resin, but in order to obtain sufficient machinability, it is necessary to make the coating material porous throughout the wall thickness. Problems have been pointed out, such as not only deteriorating the appearance but also the fact that the dimensional accuracy cannot be improved much because the molding method is limited to extrusion molding.

Furthermore, coating the core material with a material made of an olefin polymer, particularly polyethylene, mixed with wax and inorganic powder is also disclosed in, for example, JP-A-55-81810. This material has good machinability and good appearance, but because it contains a large amount of wax and inorganic powder, there is a large loss during material production and the cost is relatively high. In addition, since wax is used, it has low bending strength and is easily affected by temperature, and it has been said that it is difficult to decorate the surface by printing or the like, which has been a problem.

《Problems to be solved by the invention》 The present invention was devised in view of the above-mentioned circumstances, and its purpose is to provide a material that has appropriate hardness, can be easily cut, has a good appearance, and is suitable for decoration. To provide a cosmetic resin pencil which has excellent bending strength, is less affected by temperature, and can be manufactured at low cost.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the cosmetic resin pencil according to the present invention comprises a styrene elastomer, a synthetic resin compatible with the styrene elastomer, and an inorganic or organic fine powder. The present invention is characterized in that a mixture mainly consisting of the following is formed into an elongated hollow body, and a cosmetic core material is press-fitted and solidified into the hollow body.

<<Example>> The figure shows a cosmetic resin pencil according to an example of the present invention, and this pencil 1 is composed of a cosmetic core material 2 and an elongated hollow body 3 covering the periphery thereof,
It is obtained by forming the hollow body 3 by injection molding, and then press-fitting a core material in a molten or softened state into the hollow body 3, filling it, and solidifying it. The hollow body 3 is mainly made of a mixture of a styrene-based elastomer and a synthetic resin compatible with the styrene-based elastomer as a base material, and is formed from a material in which inorganic or organic fine powder and a small amount of pigment are mixed as necessary. ing. As a styrene elastomer, JIS
Styrene with a hardness of 40 to 90 measured by K6301 A
Examples include putadiene rubber, styrene-butadiene-styrene rubber, and styrene-ethylene putadiene-styrene rubber. In addition, PS is a synthetic resin that is compatible with these elastomers.
(polystyrene), AS (acrylonitrile-styrene), ABS (acrylonitrile-butadiene-styrene), MS (methyl methacrylate-styrene), MBS (methyl methacrylate-butadiene-styrene), PP (polypropylene), PE (polyethylene) ) are suitable, and desired hardness can be obtained by mixing these synthetic resins and the above-mentioned elastomers in an appropriate ratio. Furthermore, the fine powder mixed into this base material includes inorganic substances such as calcium carbonate, talc, kaolin, silica, calcium silicate, mica titanate, titanium oxide, iron oxide, and aluminum silicate, or crosslinked polystyrene, crosslinked polyethylene, and crosslinked polyethylene. Cross-linked resins such as acrylic or organic substances such as phenolic resins are mixed into particles with a particle size of 1 to 50μ.
An example is one formed into a powder of about 100 ml.

Elastomers have high bending strength due to their elasticity, but alone they are not sufficient to protect the core material.
The necessary hardness was achieved by mixing it with the synthetic resins mentioned above. Also,
The purpose of mixing the fine powder is to improve machinability, which allows the core material to be easily scraped out with a pencil sharpener, for example, and prevents the cutting scum from becoming crumbly and contaminating the surrounding area. The preferred ratio of each of these components is 20 to 50% by weight of the elastomer;
Synthetic resin 20-75% by weight, fine powder 5-30% by weight, and if the elastomer ratio is less than this range, the bending strength will be insufficient, and if it is too much, the hardness will decrease and there is a risk of problems in usability. On the other hand, the opposite can be said about the proportion of synthetic resin. Further, if the proportion of fine powder is less than 5% by weight, the machinability decreases, and conversely, if the proportion of fine powder is more than 30% by weight, although the machinability is good, there are some difficulties in formability and appearance.

As an example, the present inventors selected styrene-ethylene-butadiene-styrene rubber as the styrene-based elastomer, AS as the synthetic resin, and organic cross-linked polystyrene powder as the fine powder.
These were mixed at a ratio of 30 to 40% by weight, 50 to 60% by weight, and 10% by weight, respectively, and then injection molded to form a hollow body. When these hollow bodies were filled with core material and tested, it was confirmed that they had appropriate hardness and bending strength, and had good machinability. The surface was smooth, but since it did not contain wax, it could be easily decorated with printing, hot stamping, etc. When a small amount of pigment was added to the above mixture, a brightly colored hollow body was obtained.

<<Effects of the invention>> As mentioned above, the cosmetic resin pencil according to the invention not only satisfies the essential requirements of moderate hardness and good machinability, but also has relatively high bending strength, is easy to use, and is resistant to temperature fluctuations. It has excellent storage stability because the influence is small. In addition, since injection molding is possible, high-precision products can be mass-produced efficiently, and there is less loss of raw materials. Furthermore, desired surface decorations can be freely applied by hot stamping, printing, etc., and the product has excellent effects such as further increasing the commercial value.

[Brief explanation of the drawing]

The figure is a partially cutaway perspective view showing a cosmetic resin pencil according to an embodiment of the present invention. 2...Cosmetic core material, 3...Hollow body.

Claims (1)

[Claims for Utility Model Registration] (1) A mixture mainly consisting of a styrene elastomer, a synthetic resin compatible with the styrene elastomer, and an inorganic or organic fine powder is formed into an elongated hollow body. A cosmetic resin pencil characterized by being formed by press-fitting and solidifying a cosmetic core material into a hollow body. (2) The mixture is characterized in that it contains 20 to 50% by weight of the styrene elastomer, 20 to 75% by weight of the compatible synthetic resin, and 5 to 30% by weight of the fine powder. A cosmetic resin pencil according to claim 1 of the utility model registration claim.