JPS6033867Y2 - Synthetic rubber latex puff - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a synthetic rubber latex puff, particularly a synthetic rubber latex puff useful for use in oil-based cosmetics and contact lens polishing.

Conventionally, oil-based cosmetic puffs made from NBRXNR synthetic rubber latex sponges or polyurethane foam have been commonly used, but these inherently have poor durability and weather resistance, so they cannot be used for long periods of time. In addition to hardening and deterioration of the surface during use, this deterioration is further accelerated by thermal history such as washing with hot water, which has the disadvantage of causing mold to grow due to seepage of oil-based cosmetics.

On the other hand, silicone rubber sponge puffs mainly made of organopolysiloxane are also known, and they have excellent heat resistance and weather resistance, and cosmetic puffs made of them have the advantage of having a good feel on contact with the human body. , the cost is higher than the above-mentioned synthetic rubber latex and polyurethane, and there is a problem in economic efficiency.

The present invention was completed as a result of research by the present inventors with the aim of obtaining a puff that could overcome these disadvantages. This product is a synthetic rubber latex puff made of a layer of synthetic rubber, which has heat resistance and weather resistance similar to that of a silicone rubber sponge puff due to the hardened organopolysiloxane layer, but also has the added texture of silicone. Therefore, it has extremely excellent properties as an oil-based cosmetic puff or a contact lens polishing puff.

The figure shows a partially enlarged view of the puff of the present invention.
The rubber latex layer is a sponge containing air bubbles 2, and its surface is coated with an organopolysiloxane rubber layer 3 by treatment with organopolysiloxane, which will be described later.

The figure shows the synthetic rubber latex sponge completely covered with the silicone rubber layer 3, but depending on the method of processing the organopolysiloxane, the silicone rubber layer 3 may become a synthetic rubber latex sponge layer. Sometimes it gets into the.

The synthetic rubber latex sponge used as a material in the present invention is manufactured by a known method from synthetic rubber latex such as NBRXNR, but from the viewpoint of use as a cosmetic puff, it has relatively fine and uniform air bubbles. It is preferable to have a structure, and this material is processed with an organopolysiloxane after being processed into a curved surface if necessary.

The liquid composition is applied as the organopolysiloxane used to treat this synthetic rubber latex puff.
This may be made mainly of diorganopolysiloxane with a linear structure or organopolysiloxane with a varnish structure.
It is desirable to use a so-called silicone rubber composition that becomes a silicone rubber elastic body upon curing.

And this stuff is, for example, dimethylpolysiloxane,
It is made by adding various fillers and catalysts to polysiloxane such as dimethylvinylpolysiloxane, dimethylvinylphenylpolysiloxane, and γ-trifluoropropylmethylvinylpolysiloxane. Properties imparting agents such as heat conductive agents, foaming agents, etc. may be added, or even fungicides may be added. (type or two-component type) or those commercially available as heat-vulcanized rubber are used.

This polysiloxane may be one obtained by radical polymerization of an olefin monomer, such as an acrylic acid monomer, its ester, or styrene, or a modified organosiloxane, such as one in which a polyoxyalkylene group as a parent group is introduced into the molecular chain. Compositions based on polysiloxane may also be used.

These compositions can be used after being diluted with a solvent from the viewpoint of workability and processability, but from the viewpoint of resource conservation and pollution problems such as environmental pollution, it is desirable to use them in a solvent-free state. It is preferable to use a low viscosity RTV rubber composition.

Its viscosity is such that it can be applied or impregnated onto a synthetic rubber latex sponge without a solvent, i.e., 1 at 25°C.
It is preferable that it is 0,000 centipoise or less.

In addition, when this is diluted with a solvent, the concentration of the active ingredient is at least 5% by weight or more, preferably 2% or more by weight.
Viscosity at °C is 100,000 centipoise or less, preferably 1,000 centipoise
It is desirable that the value be 0 centipoise or less.

The method of impregnating a synthetic rubber latex sponge with a curable organopolysiloxane liquid composition is to immerse the synthetic rubber latex sponge in the liquid composition, fully impregnate it, pull it out, and then remove the excess. The inside and outside of the synthetic rubber latex sponge can be coated by squeezing it out with a roll, or by sufficiently applying the liquid composition to one or both sides of the sponge using a roll coater, knife coater, etc. (the inside is impregnated by coating). A desired amount of organopolysiloxane material is uniformly impregnated onto the surface.

Thereafter, this is dried and cured at room temperature or under heating to obtain the desired cosmetic puff based on a synthetic rubber latex sponge on which a cured layer of organopolysiloxane is formed.

Note that this puff may be made by treating the entire synthetic rubber latex sponge with a liquid composition of curable organopolysiloxane, but it may also be made of synthetic rubber that has been previously processed into the shape of a cosmetic puff (curved surface processing). Only one side of the latex sponge may be treated with a liquid composition of curable organopolysiloxane, and the opposite side may be left untreated, whereby the siliconized side has lipophilic properties; A so-called amphoteric cosmetic puff having hydrophilic properties is obtained on the untreated side.

Furthermore, a lipophilic organopolysiloxane rubber layer is formed on the inner and outer surfaces of one side of a synthetic rubber latex sponge that has been previously processed into the shape of a cosmetic puff, and a hydrophilic modified layer is formed on the inner and outer surfaces of the opposite side. It is also possible to make a puff with an organopolysiloxane rubber layer formed thereon, and with this, a cosmetic puff that has the excellent texture and weather resistance of silicone on both sides and can be used for both water-based and oil-based products can be obtained. In this case, a lipophilic organopolysiloxane rubber layer was formed using a composition mainly composed of the above-described ordinary diorganopolysiloxane, and a hydrophilic modified organopolysiloxane rubber layer containing the above-mentioned polyoxyalkylene groups was used. A composition mainly composed of modified organopolysiloxane may be used.

The puff of the present invention not only has the above-mentioned excellent properties, but also has the advantage that it does not involve any difficulty in processing the curved surface, and can also be made into a water-based or oil-based amphoteric puff.

Although this synthetic rubber latex puff has mainly been described above as a cosmetic puff, it is also said to be useful as a contact lens polishing puff, for example, and has improved polishing workability due to the presence of an organopolysiloxane hardened layer. , the polishing effect is improved.

Next, a specific example will be given.

Example 1 NB with thickness 10mm, height 100mm, width 100 groups
R latex sponge (specific gravity 0.13), solid content 25
% by weight toluene solution and a liquid type room temperature curable silicone rubber composition KE-42RTV (manufactured by Shin-Etsu Chemical Co., Ltd., trade name) at a ratio of 1:l by weight of KE-42RTV to the above sponge. Let dry and harden.

The NBR latex sponge treated with silicone rubber was punched out into a circle with a diameter of 70 mm and a thickness of 10 mm.
When a puff with a diameter of 7 mm was obtained, it was found that the oil-based cosmetic applied well and had excellent texture, texture, and weather resistance.

Example 2 A contact lens polishing puff made of a commercially available synthetic rubber latex sponge was impregnated with the toluene solution of KE-42RTV used in the previous example at a weight ratio of 1:1, and then dried. When cured, a puff with excellent polishing workability, polishing effect, and weather resistance was obtained.

Example 3 A toluene solution with a solid content of 25% by weight was applied to an NBR latex sponge with a thickness of 1-1, 100 mm in length and 100 mm in width. - Liquid type mildew-resistant room temperature-curable silicone rubber composition K
E-45YW RTV (manufactured by Shin-Etsu Chemical Co., Ltd., trade name),
The sponge was impregnated with KE-45YWRTV at a weight ratio of 1:2, dried, and cured.

The sponge treated with silicone rubber was punched out into a circular shape with a diameter of 7 mm to obtain a puff with a thickness of 1 mm and a diameter of 7 mm.
It has excellent texture, texture, and weather resistance, and does not develop mold even when penetrated by oil-based cosmetics.

[Brief explanation of the drawing]

The figure shows a partially enlarged view of the synthetic rubber latex buff of the present invention. 1... Synthetic leather rubber latex layer, 2...
Air bubbles, 3...Silicone rubber layer.

Claims (1)

[Scope of utility model registration request] A synthetic comb latex puff made of a synthetic rubber latex sponge with hardened organopolysiloxane layers formed on the inner and outer surfaces.