GB1589048A - Preparing implantable artificial hair - Google Patents

Description

(54) PREPARING IMPLANTABLE ARTIFICIAL HAIR (71) I, SHIRO YAMADA, a Japanese citizen, of No 31-8 Koboyama, Kobo-cho, Chiryu-shi, Aichi-ken, Japan, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a method of preparing an artificial hair to be implanted directly in a human skin.

Recently, there has been tried a hair implanting method, by which artificial hairs made of a synthetic resin or the like are implanted directly in a human skin. In order to enhance the fixing percentage of the artificial hairs of that kind in the human skin, moreover, there have been proposed the artificial hair with roots having an anchor shape. Since, however, the roots of artificial hairs have to be made remarkably fine and delicate, the production of hair roots having a special shape inevitably requires such advanced techniques as to make it difficult to produce artificial hairs of uniform quality in an inexpensve manner.

It is an object of the present invention to provide a remarkably simplified method of mass-producing artificial hairs which are of a uniform quality and which are formed with anchor portions.

According to the present invention, there is provided a method of preparing an artificial hair to be implanted in a human skin, comprising: inserting the hair proper of the artficial hair into a lumen of a hollow implanting needle or similar hollow pointed jig having a frusto-conical point; maintaining close contact between a root which has been formed integrally at the end of said hair proper an said frusto-conical point of said implanting needle or similar hollow pointed jig; dipping and subsequently pulling the point of said implanting needle or similar hollow pointed jig into and out of a solution of a synthetic resin, while holding the root of said hair adjacent the surface of said point; solidifying the synthetic resin, which has adhered to said point, to form a cup-shaped anchor portion on the root of said hair; and separating the artificial hair formed with said anchor portion from said implanting needle or similar hollow pointed jig.

Any filament can be used as a material for the artificial hair of the present invention, if the filament has a similar appearance and characteristics to those of natural hairs but is not harmful to the human body.

On the other hand, a variety of methods have also been proposed to form the root of the artificial hair. For example, one of the proposals forms the root into a droplet shape by applying a solution of synthetic resin to the tip of a monofilament made of the synthetic resin of the same kind. According to another proposal, a knot is made at the tip of a monofilament. For reasons of working efficiency and uniformity in the production, however, the method is preferred in which the tip of a monofilament is heated to form a root having a bottle shape.

With this in mind, therefore, it is necessary to use such a monofilament as is prepared by melt-spinning a thermo-plastic synthetic resin such as nylon, polyethylene, polyvinyl chloride or polyester and by subsequently drawing the spun monofilament strongly at the ratio of 4 to 5 times in length.

The monofilament thus prepared has characteristics to restore its conditions before the drawing treatment if it is heated to its softening temperature within the range of 120 to 180 C. If, more specifically, the monofilament having a diameter of 0.06 to O.lmm is heated at its tip of a length of 4.0 to 6.0mm to a temperature of 1500C, such a root having a bottle shape is obtained as appears a cylinder having a length of 1.0 to 1.Smm and a diameter of 0.13 to 2.00mm.

In the method according to the present invention, it is preferred that the tip of the monofilament having a length of 0.8 to l.Smm is heated to form a root having a length of 0.2 to 0.4mm.

Now, the jig for forming the cup-shaped anchor portion can use a hollow implanting needle itself, which in turn is used to accomplish the implantation of the artificial hairs of the present invention. It is, how ever, preferable that a jig having a similar shape to but a slightly larger taper angle than the implanting needle is used with a view to ensuring easy separation between the implanting needle and the anchor por tion of the artificial hair when the former is extracted after the implantation.

An embodiment of the invention will now be described by way of example and with reference to the accompanying draw ings in which: Fig. 1 is a longitudinal section showing an artificial hair which is prepared by the method according to the present inven tion; Fig. 2 is a cross-section taken along the line A-A of Fig. 1; Figs. 3 and 4 are explanatory views showing the example of accomplishing the method of the present invention; and Figs. S and 6 are explanatory views showing the method of using the artificial hairs which are prepared by the method of the present invention.

Referring now to Figs. 1 and 2, there is shown an artificial hair which is produced to have a cup-shaped anchor portion according to the present invention. Indicated at reference numeral 1 is the hair proper of the artificial hair which is formed at its one end with a root 2.

The jig for forming the cup-shaped anchor portion is shaped, as shown in Fig. 3, to include a body 6 which has its upper portion acting as a handle 7 and which has a needle 8 jointed to the one end thereof.

This needle 8 is cut at its extending end to form a frusto-conical point 10 and formed at its center with a lumen 9 which extends continuously through the needle 8 and further through the handle 7.

The process of forming a cup-shaped anchor portion 3 will now be described in the following. First of all, the hair proper 1 of the artificial hair with the root 2 is inserted into the lumen 9 of the jig 6 with the root 2 positioned at the flat face of the frusto-conical point 10 of the jig 6. Under the condition as shown in Fig. 3, the jig 6 is then dipped from 0.4 to 0.8mm in depth into a sofution of a synthetic resin 11 which is held in a bath 12. After this dipping operation has been repeated several times, the jig 6 is pulled out of the synthetic resin solution for the subsequent natural drying treatment for about thirty minutes.

Then, the point of the jig 6 is covered with a film of the synthetic resin, as seen from Fig. 4.

The synthetic resin solution used was prepared by wetting powders of polyvinyl chloride with acetone and then by dissolving the powders with about ten times by weight of tetrahydrofuran. Alternatively, a reactive liquid resin such as unsaturated polyester or epoxy resin can be used in place of polyvinyl chloride.

In order to produce an uniform article, however, it is the most important to adjust the viscosity of the synthetic resin solution.

If the solution is too thin, it will flow down so that the product having the desired thickness cannot be obtained. If, on the contrary, the solution is too viscous, a product of uniform quality cannot be obtained.

The experiments conducted by the inventor revealed that the most satisfactory results were obtained in the case of the viscosity of 200 to 600 centipoise.

The synthetic resin cover film thus formed at the point of the jig is peeled off from the jig together with the artificial hair by means of a pincet. Then, the artificial hair is put into a vacuum drier for several hours so that the residual solvent may be completely removed from the cover film. Finally, the sterilization is carried out by the use of ethylene oxide gases so as to obtain the desired artificial hair. This hair has its anchor portion sized to have a length of 0.5 to l.Omm and the maximum outer diameter of 0.3 to 0.5mm.

Although the foregoing description has been directed to the method in which the material for the artificial hair is formed in advance with the root, this root can also be prepared'by the use of the anchor-forming jig itself.

More specifically, a synthetic resin monofilament having no root is inserted into the lumen 9 of the jig until its leading end protrudes from the point of the jig by about Imm. The end of the monofilament thus protruding softens and shrinks, when exposed instantaneously to a hot wind at a temperature of 120 to 1800C, so that it is rounded to form the desired root of an enlarged diameter. Since, in this way, the root can be formed while the artificial hair material is being held in the jig, smooth transfer can be accomplished to the next dipping step with the resultant improvement in the working efficiency.

Now, the following description is concerned with the method of using or implanting the artificial hair which is prepared according to the present invention.

With reference to Fig. 5, the hair proper 1 is inserted into the lumen 15 of an implanting needle 13 having a similar shape to the jig 6 until the shoulder 5 of the anchor portion 3 abuts against the flattened point 14 of the needle 13. The needle 13 under that condition is thusted into the epidermis 16 until its point comes to an intermediate position between the dermal tissue 17 and the hypodermal tissue 18.

Then, the needle 13 is extracted so that the artificial hair can be retained fixedly in position in the tissue of the human body, as seen from Fig. 6. Since the anchor portion 3 is formed with an outwardly expanding skirt 4, it can exhi'bit such a remarkably high resistance to any extracting force of the implanted hair.

It should be appreciated as a high industrial value of the method according to the present invention that the artificial hairs having a remarkably fine root of special shape can be prepared remarkably simply but efficiently.

WHAT I CLAIM IS: 1. A method of preparing an artificial hair to be implanted in a human skin, comprising: inserting the hair proper of the artificial hair into a lumen of a hollow implanting needle or similar hollow pointed jig having a hollow frusto-conical point; maintaining close contact between a root which has been formed integrally at the end of said hair proper and said frustoconical point of said implanting needle or similar hollow pointed jig; dipping and sub- sequently pulling the point of said implanting needle or similar hollow pointed jig into and out of a solution of a synthetic resin, while holding the root of said hair adjacent the surface of said point; solidifying the synthetic resin, which has adhered to said point, to form a cup-shaped anchor portion on the root of said hair; and separating the artificial hair formed with said anchor portion from said implanting needle or similar hollow pointed jig.

2. A method of preapring an artificial hair to be implanted in a human skin, which method is substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. position in the tissue of the human body, as seen from Fig. 6. Since the anchor portion 3 is formed with an outwardly expanding skirt 4, it can exhi'bit such a remarkably high resistance to any extracting force of the implanted hair. It should be appreciated as a high industrial value of the method according to the present invention that the artificial hairs having a remarkably fine root of special shape can be prepared remarkably simply but efficiently. WHAT I CLAIM IS:

1. A method of preparing an artificial hair to be implanted in a human skin, comprising: inserting the hair proper of the artificial hair into a lumen of a hollow implanting needle or similar hollow pointed jig having a hollow frusto-conical point; maintaining close contact between a root which has been formed integrally at the end of said hair proper and said frustoconical point of said implanting needle or similar hollow pointed jig; dipping and sub- sequently pulling the point of said implanting needle or similar hollow pointed jig into and out of a solution of a synthetic resin, while holding the root of said hair adjacent the surface of said point; solidifying the synthetic resin, which has adhered to said point, to form a cup-shaped anchor portion on the root of said hair; and separating the artificial hair formed with said anchor portion from said implanting needle or similar hollow pointed jig.

2. A method of preapring an artificial hair to be implanted in a human skin, which method is substantially as hereinbefore described with reference to the accompanying drawings.