IP Library › Granted Patent US 12,622,477
Granted Patent B2
US 12,622,477 · App. 17/793,028 · Granted May 12, 2026

Hair extension

Inventor: Ryuki Hirano (Nagoya, JP)
A41G5/008
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Quick Facts
Patent No.
US 12,622,477
App. No.
17/793,028
Granted
May 12, 2026
Kind
B2
Abstract

Problem Provided is a practical hair extension configured to be very easily attached to head hair (natural hair) and attachment of which on the head hair is less likely to be noticed by other people. Solution A hair extension 1 includes a hair bundle 2 , a double-sided adhesive tape 3 , and a release paper 4 . The hair bundle 2 has a base end including a first hair layer L 1 formed by laterally aligning a plurality of hairs h 1 , h 1 . . . such that base end edges of the plurality of hairs are linearly arranged and bonding vicinities of the base ends of the hairs h 1 , h 1 with an adhesive so as to have a constant adhesive width, and a second hair layer L 2 formed by laminating a plurality of hairs h 2 , h 2 . . . to be laterally aligned on an upper side of the first hair layer L 1 such that base end edges of the plurality of hairs are linearly arranged and bonding vicinities of the base ends of the hairs h 2 , h 2 . . . with an adhesive so as to have an adhesive width narrower than the adhesive width of the first hair layer L 1 . Furthermore, the double-sided adhesive tape 3 is stuck to the first hair layer L 1 .

Claims (37)

1 . A hair extension comprising:

a hair bundle composed with a first hair bundle and a second hair bundle that are a plurality of hairs,

a base end that is fixed to a proximal end of the hair bundle; and

a double-sided adhesive tape that is stuck to the base end and is configured to attach the hair bundle to natural hairs of a user, wherein

the base end of the hair bundle includes:

a first base that is a mass of cured resin and has a thin layer shape such that a proximal end of the first hair bundle is retained inside the first base and the hairs of the first hair bundle extend from the first base in a vertical direction and align in a horizontal direction, which is perpendicular to the vertical direction, wherein the first base has a predetermined length in the vertical direction and a predetermined thickness in a thickness direction, which is perpendicular to both the vertical direction and the horizontal direction, and the first base has two surfaces facing in opposite directions to each other, and the double-sided adhesive tape is attached to one of the surfaces of the first base,

a second base that is a mass of cured resin and has a thin layer shape such that a proximal end of the second hair bundle is retained inside the second base, and the hairs of the second hair bundle extend from the second base in the vertical direction and align in the horizontal direction wherein the second base has a predetermined length in the vertical direction and a predetermined thickness in the thickness direction, wherein the second base is placed on the other of the surfaces of the first base, which is opposite from the double-sided adhesive tape,

the first base and the second base are both made of polyurethane-based resin,

the thicknesses of the first base and the second base are constant in the vertical direction and are each ranged from 0.05 mm to 0.4 mm, and the thickness of the second base is smaller than the thickness of the first base,

the length of the second base is shorter than the length of the first base, and

upper edges of the first base, the second base, and the double-sided adhesive tape in the vertical direction are aligned flush, forming an upper edge of the base end.

2 . The hair extension according to claim 1 , wherein

cutouts are formed at the upper edge of the base end at predetermined intervals in the horizontal direction, and

each of the cutouts has a slit that extends away from the upper edge of the base end in the vertical direction such that the slits are arranged in parallel at predetermined intervals in the horizontal direction.

3 . The hair extension according to claim 2 , wherein

the double-sided adhesive tape is formed of polyester-based resin,

each of the cutouts has an isosceles triangle shape of which a base is located at the upper edge of the base end and an apex is directed away from the upper edge of the base end in the vertical direction,

the slit that corresponds to each of the cutouts extends from the apex of the triangle shape, and

a width of the base of the triangle shape in the horizontal direction is approximately the same as a length of the slits in the vertical direction.

4 . The hair extension according to claim 3 , wherein

each of the cutouts has a triangle shape.

5 . The hair extension according to claim 4 , wherein

the thicknesses of the first base and the second base are each ranged from 0.2 mm to 0.4 mm.

6 . The hair extension according to claim 4 , wherein

the proximal end of the first hair bundle is located at the upper edge of the first base, and the first hair bundle penetrates the first base in the vertical direction, and

the proximal end of the second hair bundle is located at the upper edge of the second base, and the second hair bundle penetrates the second base in the vertical direction.

7 . The hair extension according to claim 3 , wherein

the thicknesses of the first base and the second base are each ranged from 0.2 mm to 0.4 mm.

8 . The hair extension according to claim 7 , wherein

the proximal end of the first hair bundle is located at the upper edge of the first base, and the first hair bundle penetrates the first base in the vertical direction, and

the proximal end of the second hair bundle is located at the upper edge of the second base, and the second hair bundle penetrates the second base in the vertical direction.

9 . The hair extension according to claim 3 , wherein

the proximal end of the first hair bundle is located at the upper edge of the first base, and the first hair bundle penetrates the first base in the vertical direction, and

the proximal end of the second hair bundle is located at the upper edge of the second base, and the second hair bundle penetrates the second base in the vertical direction.

10 . The hair extension according to claim 1 , wherein

the proximal end of the first hair bundle is located at the upper edge of the first base, and the first hair bundle penetrates the first base in the vertical direction, and

the proximal end of the second hair bundle is located at the upper edge of the second base, and the second hair bundle penetrates the second base in the vertical direction.

Priority Claims (1)
JP 2020-007552 · Jan 21, 2020 · national
Continuity (1)
Related Publication 20230040318A1 · Feb 9, 2023
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