JPH0560803B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to solid cosmetics that are excellent in shape retention, feel when used, and long-lasting makeup. [Prior Art] Typical solid cosmetics include bar-shaped cosmetics such as lipsticks, lip balms, foundation sticks, and eyelashes, pencil-type cosmetics such as eyebrow pencils, and eyeliner pencils,
There are pressed powders such as foundation, eye shadow, and blush, and oil-based cake-like cosmetics. Among these, oil-based cosmetics are conventionally made from solid fats such as carnauba wax, candelilla wax, ceresin, microcrystalline wax, hydrogenated animal and vegetable fats, and beeswax, as well as castor oil, olive oil, jojoba oil, squalane, and various synthetic ester oils. Powder is dispersed in a mixed system with a liquid or semi-liquid oil such as silicone oil, liquid paraffin, or petrolatum. When attempting to manufacture solid cosmetics as described above by combining these conventionally used oils, it is possible to achieve the required performance of the product by adjusting the ratio of solid fat and liquid or semi-liquid oil. Shape retention, usability, and makeup retention must be satisfied. However, it is difficult to satisfy these requirements at the same time. The reason may be as follows. The organizational structure of oil-based cosmetics is generally thought to be one in which solid fat crystals form a network structure, and the network is filled with liquid oil.The strength and flexibility of this network structure is what makes cosmetics so effective. It plays a major role in the feeling of use and the longevity of makeup. That is, when there is a lot of solid fat (there is little liquid oil), the network structure is dense and the structure is strong, so the makeup lasts well, but it spreads hard and has a hard touch, which gives a poor feeling of use. On the other hand, when there is less solid fat (more liquid oil), the mesh structure is coarser and the structure is weaker, so makeup doesn't last long, but it spreads easily and is soft to the touch, giving a good feel. In this way, it is difficult to simultaneously satisfy the performance requirements of cosmetics simply by adjusting the ratio of solid fat and liquid oil, and the same is true even by changing the type of oil. For example, in bar-shaped cosmetics such as lipsticks and pencil-type cosmetics such as eyeliners, reducing the amount of solid fat (increasing the amount of liquid oil) will result in products that spread easily, are soft to the touch, and have a good feel. Regarding makeup retention, it has been observed that makeup smudges easily, fades easily, and easily transfers color. On the other hand, if you increase the amount of solid fat (reduce the amount of liquid oil), you will experience a deterioration in the feel of the product, such as hard application, hard touch, and roughness, but your makeup will last longer. In addition, pressed powder type cosmetics have a large proportion of powder, and the above-mentioned oil component is used for the purpose of adjusting the feel during use and bonding or shape retention during molding. In this case, if the bonding force between the powder particles is insufficient, the powder may collapse during use, have low impact resistance, and may break or crack. On the other hand, if the bonding force between powder particles is too strong, it will be difficult to apply by puffing or brushing, and the appearance will deteriorate due to oily shine. It is difficult to solve this phenomenon by simply adjusting the ratio of solid fat and liquid oil, changing the type of oil, and adjusting molding conditions such as press pressure. [Problems to be solved by the invention] As described above, when trying to produce solid cosmetics using only the combination of oils that have been used in the past, the properties necessary for the product, such as shape retention, feeling of use, and It is difficult to simultaneously satisfy makeup durability and other desirable properties. The present invention aims to solve the drawbacks of the prior art and to provide a solid cosmetic that satisfies all of shape retention, feeling of use, and makeup durability. [Means for solving the problem] Polyethylene wax was conventionally used as a solidifying agent for oil-based cosmetics (Japanese Patent Application Laid-Open No. 15904-1983).
(see publication). However, when low polarity oils such as liquid paraffin, polyisobutylene and squalane are used as liquid oils, they do not exhibit solidifying power. On the other hand, when oils with hydroxyl groups in their molecules (e.g. diisostearyl malate) are used as liquid oils, they exhibit strong solidifying power; Extremely reduces stretch. As described above, when trying to obtain high solidifying power, the situation was such that good "spreadability" during use could not be obtained. However, the present inventors found that when polyethylene wax was used as a wax component, low viscosity fatty acid triglyceride or low viscosity fatty acid diglyceride (for example, 2-ethylhexanoic acid triglyceride or 2-ethylhexanoic acid diglyceride) was converted into a liquid. The present inventors have discovered that by using it as an oil, it is possible to obtain an oil-based solid cosmetic that has high solidifying power and good "spreadability" during use, and has completed the present invention. That is, the present invention uses (a) a polyethylene wax with an average molecular weight of 700 to 2000 as a wax component, and (b) a low viscosity fatty acid triglyceride or low viscosity fatty acid diglyceride that is liquid at room temperature and has a viscosity of 2000 centistokes or less as a liquid oil. This relates to solid cosmetics characterized by containing: As the polyethylene wax in the present invention, high-density polyethylene having an average molecular weight of about 700 to 2000 is preferable. Since low-density polyethylene has poor crystallinity, it does not exhibit high shape retention. In addition, polyethylene with an average molecular weight of less than 700 exhibits a low melting point in the system, the amount of crystals at temperatures slightly higher than room temperature decreases, and the shape retention of solid cosmetics at high temperatures is poor. On the other hand, polyethylene with an average molecular weight of more than 2000 has a too high melting point and therefore requires high temperatures when producing solid cosmetics, leading to deterioration of other ingredients and making it difficult to produce. However, when high-density polyethylene with an average molecular weight of about 700 to 2000 is used, there is little change in the amount of crystals at room temperature and at temperatures slightly higher than room temperature, so it exhibits good shape retention and can be solidified at moderate temperatures during manufacturing. Cosmetics can be manufactured. The low-viscosity fatty acid triglyceride and low-viscosity fatty acid diglyceride used as the liquid oil in the present invention need to be liquid at room temperature and have a low viscosity, that is, have a viscosity of 2000 centistokes or less at room temperature. If the viscosity is high, when a solid cosmetic is applied to the skin, the wax network structure is destroyed and a liquefied paste adheres to the skin.
becomes heavy. Therefore, low viscosity fatty acid triglycerides or low viscosity fatty acid diglycerides include those with low viscosity and short fatty acid chains, specifically 2
-ethylhexanoic acid, octanoic acid, oleic acid,
Triglycerides or diglycerides of myristic acid or isostearic acid may be mentioned, and triglycerides or diglycerides of 2-ethylhexanoic acid or octanoic acid are particularly preferred. It is not yet clear why a combination system of polyethylene wax and low-viscosity triglyceride or low-viscosity diglyceride exhibits high shape retention, but it is believed that this is due to the formation of a network structure of wax crystals precipitated in solid cosmetics in liquid. It seems to depend on whether the force between the wax crystals is strong or weak. In a non-polar liquid such as liquid paraffin, the force acting between polyethylene wax crystals is small, and the polyethylene wax exhibits only weak shape retention. On the other hand, in triglycerides and diglycerides with higher polarity, the strength is large and it is thought that they exhibit high shape retention (see Table 1).

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Note that parts in the examples are based on weight. Example 1 (Lipstick) Each component shown in Table 2 was heated to 120°C, mixed uniformly, poured into a mold, and cooled to solidify to produce a lipstick. The shape retention of the obtained lipstick was evaluated, and a specialized panel
Performance evaluation was conducted by 10 people. The results are shown in Table 3.

【table】

[Table] From these results, the product of the present invention has excellent shape retention, feel (spreadability, stickiness, smoothness, stickiness, and firmness),
It can be seen that it has excellent makeup retention (color fading, smudging resistance). Example 2 (Eyebrow Pencil) Each component shown in Table 4 was heated to 120°C and kneaded repeatedly using a roll mill. This was cooled to room temperature and molded by extruding the core from a nozzle using a squeeze injection machine. The core is attached to a piece of wood with a core-shaped groove, and formed into a pencil shape by gluing, conjugation, and cutting.
Manufactured eyebrow pencil. The shape retention of the obtained eyebrow pencil was evaluated, and the performance was evaluated by 10 expert panelists. The results are shown in Table 5.

【table】

[Table] From these results, the product of the present invention has excellent shape retention, usability (ease of writing, softness, smoothness, unevenness),
It can be seen that it has excellent makeup retention (makeup does not come off). Example 3 (Solid Powder Eye Shadow) Among the components shown in Table 6, the powder part was stirred and mixed in a blender, and the oil phase part heated and uniformly dissolved therein was sprayed and further stirred. Thereafter, it was crushed and compression molded using a molding machine to produce solid powder eyeshadow. Regarding the obtained solid powder eye shadow,
Impact resistance evaluation and performance evaluation were conducted by 10 expert panelists. In addition, the impact resistance evaluation is based on the drop strength from a height of 100 cm.
Items that were dropped on the floor once and showed no abnormalities such as cracks were evaluated as ○, and items that were cracked were evaluated as ×. The results are shown in Table 7.

【table】

[Table] From the results, it can be seen that the product of the present invention is excellent in shape retention, feel in use (ease of spreading, sticking), and makeup retention (kinking, removal).

Claims (1)

[Claims] 1 (a) Average molecular weight as wax component: 700-2000
and (b) a low-viscosity fatty acid triglyceride or low-viscosity aliphatic diglyceride that is liquid as a liquid oil at room temperature and has a viscosity of 2000 centistokes or less.