WO2023107050A2

WO2023107050A2 - Synthetic hair production from acrylic fiber

Info

Publication number: WO2023107050A2
Application number: PCT/TR2022/051328
Authority: WO
Inventors: Arzu MERAL; Gürcan KOMAN
Original assignee: Aksa Akrilik Kimya Sanayii AS
Current assignee: Aksa Akrilik Kimya Sanayii AS
Priority date: 2021-11-23
Filing date: 2022-11-21
Publication date: 2023-06-15
Anticipated expiration: 2024-05-23
Also published as: CN118434320A; WO2023107050A3; KR20240113799A

Abstract

The invention relates to a production method that enables to obtain synthetic hair and hairpieces with deformation properties from acrylic fiber obtained by polymerizing 80-98% acrylonitrile and 2-20% vinylacetate monomers, which is made easier to be shaped by reducing the filament irregularity after the fiber bundle is wetted and which is provided with natural and shiny appearance without increasing its water shrinkage.

Description

SYNTHETIC HAIR PRODUCTION FROM ACRYLIC FIBER

Technical Field

The invention relates to a production method that enables to obtain non-deformable synthetic hair and hairpieces from acrylic fiber obtained by polymerizing 80-98% acrylonitrile and 2- 20% vinylacetate monomers, which is made easier to be shaped by reducing the filament irregularity after the fiber bundle is wetted and which is provided with natural and shiny appearance without increasing its water shrinkage.

The State of the Art

Acrylic fiber is a compound formed by the reaction of vinyl acetate and acrylonitrile, which is a monomer widely used in the synthesis of various organic products such as resins and plastics. Acrylic fiber, which has been known as a substitute for wool since the 1940s, is aimed to be used in the field of cosmetics (hairpieces, wigs, hair braids, etc.) in addition to textile (sweaters, socks, carpets, blankets, etc.) and industrial (dust filter, reinforcing filling material in building construction).

In the known art, acrylic fibers are conventionally known to be used as artificial hair fibers due to their feel, shine and voluminosity are similar to human hair. For example, the patent document numbered JP4128024B2 discloses an acrylic synthetic fiber for artificial hair comprising 35 wt% or more acrylonitrile as the main component and comprising an acrylic copolymer pre-colored with a dye and/or a pigment at the fiber manufacturing step and having a single yarn fineness of 25 to 75 dtex. In the present application, it is stated that said fiber has a dynamic viscoelasticity tan 6 of 0.3 or less at 80 °C and is intended to improve the opacity of the artificial hair.

In patent application numbered WO2012043348A1, synthetic fibers obtained from an acrylonitrile polymer comprising 30 to 80 wt% acrylonitrile and 20 to 70 wt% vinyl chloride and/or vinylidene chloride are suggested for doll hair. The present invention is intended to improve the combing and shaping properties. The invention of document numbered WO2020238543A1 relates to a method for producing functional protein hair strands that are easy to use, low in cost, and can be produced on a large scale. The present invention provides a method for wet spinning human hair-like functional protein fibers, including a spinning material preparation step. The spinning material comprises protein powder processed from animal hair and/or human hair and an acrylonitrile copolymer consisting of 35 to 55 wt% acrylonitrile, 35 to 45 wt% vinylidene chloride, 6 to 8 wt% vinyl monomers containing sulfonic acid groups, and prepared by copolymerization of 3.5-6.0 wt% acrylate.

In standard acrylic fiber production, curling is applied to ensure cohesion, curl depth is 1-10, and curl % 1-20. The acrylic hair fiber bundle is washed for reuse. Hair fiber produced with a curl depth of 1-10 and curly 1-20% loses its straight filament format after wetting. This makes it difficult to reshape the hair fiber bundle and worsens the results in deformation analysis. Deformation analysis of hair fiber means that straightened (blow-dried) synthetic hair fiber does not lose its filament form (single filament straightness) after wetting. There is a need for the production of acrylic fibers that enable synthetic hair to be easily shaped after the fiber bundle is wetted, does not lose its natural appearance and shine, and can therefore be washed and used repeatedly.

As a result, due to the above-mentioned negativities and shortcomings, the need for innovation in the related technical field has emerged.

The Object of the Invention

The present invention relates to the production of synthetic hair from acrylic fiber, which meets the above-mentioned requirements, eliminates all disadvantages, and brings some additional advantages.

The main object of the invention is to provide a production method that gives synthetic hair and hairpieces obtained from acrylic fibers obtained by polymerization of 80-98% acrylonitrile and 2-20% vinylacetate monomers a washable and reusable property. The object of the invention is to obtain synthetic hair and hairpieces with reduced filament irregularity and easy shaping after the fiber bundle is wetted.

The object of the invention is to provide a production method that ensures the deformation property of acrylic hair fiber.

The object of the invention is to provide a production method that enables the production of soft synthetic hair and hairpieces with a natural and shiny appearance, which does not increase their water shrinkage.

In order to achieve the objects described above, the invention is an acrylic fiber production method comprising the process steps of

• polymerizing 80-98% acrylonitrile and 2-20% vinylacetate monomers,

• preparing the dop solution by dissolving the obtained polymer in a solvent,

• delivering the dop mixture by means of a pump to plates called spinnerets, which have holes thereon to determine the fiber diameter, and giving the dop mixture coming out of the plates a filament form in a coagulation bath (water-solvent mixture),

• washing the said filament to remove excess solvent thereon,

• transferring the washed filaments into the finishing bath without allowing them to dry and then drying, in order to obtain synthetic hair and hairpieces, characterized in that it comprises the process steps of

• annealing the filaments coming out after drying to reduce filament irregularity after the fiber bundle is wetted, with curl depth 0 and curl 0%,

• flattening the acrylic hair fiber obtained after annealing, by using saturated steam in the range of 2-10 bar to reduce its water shrinkage properties and to make it look more natural, soft, and shiny.

The structural and characteristic features and all advantages of the invention will be more clearly understood with the detailed description given below and therefore the evaluation should be made by considering this detailed description. Detailed Description of the Invention

In this detailed description, the production of synthetic hair from acrylic fiber, which is the subject of the invention, is described solely for a better understanding of the subject and without any limiting effect.

The invention relates to a method of producing synthetic hair and hairpiece from acrylic fiber obtained by polymerization of 80-98% acrylonitrile and 2-20% vinylacetate monomers. The invention is characterized in that the development of a production method that enables the production of synthetic hair and hairpieces from acrylic fiber with deformation properties, which is made easier to be shaped by reducing the filament irregularity after the fiber bundle is wetted and which is provided with natural and shiny appearance without increasing its water shrinkage.

Method of producing synthetic hair and hairpieces from acrylic fibers;

• 80-98% acrylonitrile and 2-20% vinylacetate monomers are polymerized,

• The obtained polymer is dissolved in a solvent to prepare the dop solution,

• The dop mixture is delivered by a pump to plates called spinnerets, which have holes thereon to determine the fiber diameter, and the dop mixture coming out of the plates is given filament form in a coagulation bath (water-solvent mixture),

• Then, said filament is washed to remove excess solvent thereon,

• The washed filaments are transferred into the finishing bath without allowing them to dry and then dried,

• In order to reduce filament irregularity after wetting of the fiber bundle, the filaments after drying are annealed when the curl depth is 0 and the curl is 0%,

• The acrylic hair fiber obtained after annealing is straightened by using saturated steam in the range of 2-10 bar to reduce the water shrinkage of the fiber and to make it look more natural, soft, and shiny.

In the production method of the invention, DMF (dimethylformamide) or DMSO (dimethylsulfoxide), or NaCNS (sodium thiocyanate) aqueous solution, more preferably DMAc (dimethylacetamide) can be used for the preparation of the said dop solution. To determine the curl depth of the filaments, a 0.001-0.01 gram/denier weight is attached to the end of a single filament with tweezers. The filament length is measured with and without hanging the weight. The curl depth is determined by applying the filament length measurement obtained without hanging the weight (LI) and the filament length measurement obtained by hanging the weight (L2) to the formula below.

Curl depth= (L2-L1)/L2

The molecules are parallelized with the draft given to the fiber in the fiber drafting machine. Too oriented fiber is brittle. It is loosened under steam at a certain pressure, temperature and time. Molecules change from an oriented state to a crystalline state and the elongation value increases. In the annealing process, steam pressure, temperature, time, and fiber car weight vary according to product properties. In the method of the invention, the annealing pressure is optimized to be 0.3-3.5 bar, temperature 107-148 °C, annealing time 20-70 minutes, and car weight 200-1000 kg.

The fiber fineness of the synthetic hair and hairpiece obtained by the method of the invention is in the range of 35-60 dtex.

The synthetic hair obtained by the method of the invention was subjected to a deformation test. In the deformation test, straightened hair filaments are immersed in water at a temperature of 95 °C, left for 2-15 seconds, and removed. In the last step, the irregularity of a single filament is checked. As a result of the deformation test, it was determined that the filament, which was flat before water immersion, did not lose its smoothness and did not become wavy after water immersion.

Claims

CLAIMS An acrylic fiber production method comprising the process steps of

• polymerizing 80-98% acrylonitrile and 2-20% vinylacetate monomers,

• preparing the dop solution by dissolving the obtained polymer in a solvent,

• washing the said filament to remove excess solvent thereon,

• flattening the acrylic hair fiber obtained after annealing, by using saturated steam in the range of 2-10 bar to reduce its water shrinkage properties and to make it look more natural, soft, and shiny. The production method according to claim 1, characterized in that said annealing operation is carried out under 0.3-3.5 bar pressure, at a temperature of 107-148 °C, for 20- 70 minutes, with a car weight of 200-1000 kg. The synthetic hair and hairpiece obtained by the production method as claimed in any one of claims 1-2, wherein it has a fiber fineness of 35-60 dtex.

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