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CN-121992656-A - Super absorbent fiber, preparation method and application of super absorbent fiber in paper diapers

CN121992656ACN 121992656 ACN121992656 ACN 121992656ACN-121992656-A

Abstract

The invention relates to the technical field of fibers, in particular to a super absorbent fiber, a preparation method and application of the super absorbent fiber in paper diapers. Aiming at the problems of poor liquid retention and weak interface bonding of the existing water-absorbent resin under pressure, an anchoring site is introduced through allylamine-hydrolyzed polyester fiber, then the anchoring site is subjected to light polymerization with an inner monomer system (deionized water, sodium hydroxide, acrylic acid, N' -methylene bisacrylamide and a photoinitiator 2959), ion crosslinking and semi-drying are carried out by using a calcium salt treatment solution, and finally the anchoring site is subjected to light polymerization with an outer monomer system (containing sodium dodecyl sulfate, lauryl methacrylate, acrylic acid, acrylamide and the like). The obtained fiber is subjected to covalent connection and gradient crosslinking, the inner layer is high in interlocking water, the outer layer contains a hydrophobic micro-area flexible network, and the fiber has high water absorption rate, excellent centrifugal liquid retention capacity, compressed absorption capacity, quick absorption, low rewet and high cycle compression stability, and is suitable for the absorption core layer of a paper diaper.

Inventors

  • SONG YONGHUI

Assignees

  • 佛山市爱佳卫生用品有限公司

Dates

Publication Date
20260508
Application Date
20260120

Claims (10)

  1. 1. The preparation method of the super absorbent fiber is characterized by comprising the following steps of: (1) Carrying out aminolysis modification on polyester fibers by adopting allylamine to obtain allylamine modified polyester fibers; (2) Contacting allylamine modified polyester fiber with an inner layer monomer system, and initiating in-situ crosslinking graft polymerization under illumination in an inert atmosphere to obtain a grafted fiber intermediate; (3) Placing the grafted fiber intermediate in a treatment solution containing calcium salt for treatment, so that divalent calcium ions and carboxyl groups of an inner layer form ion crosslinking, and performing semi-drying treatment to obtain semi-dried fibers; (4) Contacting the semi-dry fiber with an outer monomer system, initiating in-situ crosslinking graft polymerization by illumination under inert atmosphere, washing and drying after polymerization to obtain the super absorbent fiber; in the step (2), the inner layer monomer system is prepared from deionized water, sodium hydroxide, acrylic acid, N' -methylene bisacrylamide and a photoinitiator 2959 according to a mass ratio of 89:0.9-1.5:10:0.18-0.25:0.18-0.25; In the step (4), the outer monomer system is prepared from deionized water, sodium dodecyl sulfate, lauryl methacrylate, sodium hydroxide, acrylic acid, acrylamide, N' -methylene bisacrylamide and a photoinitiator 2959 according to the mass ratio of 70:0.2-0.4:0.2-0.4:3.5-5.2:10-14:3:0.05-0.08:0.22-0.28.
  2. 2. The method for preparing super absorbent fibers according to claim 1, wherein in the step (1), the aminolysis modification is performed in absolute ethyl alcohol, and after allylamine and absolute ethyl alcohol are prepared into an aminolysis reaction liquid, nitrogen is introduced to replace air, and the reaction is performed for 1.5-2.5 hours under the constant temperature condition of 33-37 ℃.
  3. 3. The method of claim 1, wherein in the step (1), the polyester fibers are polyester staple fibers having a fineness of 1.67 dtex.
  4. 4. The method for producing superabsorbent fiber of claim 1, wherein in step (1), the mass ratio of allylamine to polyester fiber is 20-40:10.
  5. 5. The method for producing a super absorbent fiber according to claim 1, wherein in the step (2), the mass ratio of the allylamine modified polyester fiber to the inner layer monomer system is 10:95-105.
  6. 6. The method for producing super absorbent fibers according to claim 1, wherein in the step (3), the semi-drying treatment is performed at 45 ℃ and intermittently weighed until the total mass of the sample reaches a predetermined range, wherein the predetermined range is 18 to 22 parts by mass based on 10 parts by mass of the grafted fiber intermediate.
  7. 7. The method of producing superabsorbent fiber of claim 1, wherein in step (3), the mass ratio of the grafted fiber intermediate to the treating fluid is from 10:195 to 205.
  8. 8. The method of producing superabsorbent fibers of claim 1 wherein in step (4), the mass ratio of semi-dry fibers to outer monomer system is from 18 to 22:85 to 95.
  9. 9. A superabsorbent fiber characterized by being obtained by the process for producing a superabsorbent fiber as defined in any one of claims 1 to 8.
  10. 10. Use of the superabsorbent fibre according to claim 9 for the preparation of an absorbent core layer of a pant diaper.

Description

Super absorbent fiber, preparation method and application of super absorbent fiber in paper diapers Technical Field The invention relates to the technical field of fibers, in particular to a super absorbent fiber, a preparation method and application of the super absorbent fiber in paper diapers. Background Sanitary products such as paper diapers and the like commonly adopt granular super absorbent resin as a core water locking material, which realizes high-rate water absorption through an ion crosslinking network, but in actual use, when being extruded by human body pressure or movement, gaps among resin particles are compressed, internal water is easy to be extruded, so that the liquid retention rate is reduced and the surface rewet is increased. Meanwhile, the resin particles and the fiber base material (such as terylene) are combined mainly through physical mixing or simple coating, the interface binding force is weak, and relative displacement is easy to occur under the long-term compression or shearing action, so that the water absorber is loose in structure and the water locking channel is damaged, and the performance attenuation is further aggravated. To solve the above problems, the prior art attempts to hydrophilically modify or surface graft-treat the fibers, for example, to increase the hydrophilicity of the fibers by plasma treatment, alkali etching or monomer grafting. However, most of hydrophilic layers formed by the method are physically adsorbed or non-covalently combined, easily swelled and fall off in a wet environment, and the interface stability of the modified layer and the fiber matrix is insufficient, so that the modified layer is difficult to bear multiple pressure cycles. In addition, the single hydrophilic layer with high crosslinking degree can improve the liquid retention strength but sacrifice the absorption speed, while the low crosslinking structure is favorable for quick water absorption but difficult to resist network collapse under pressure. On the other hand, in order to coordinate the absorption speed and the liquid retention performance, part of schemes adopt a multilayer composite structure or add hydrophobic components, but a multilayer interface is easy to form mass transfer resistance, so that the liquid distribution efficiency is reduced, and if the nano-scale uniform distribution is not realized by introducing the hydrophobic components, a local water blocking area is easy to form, so that the effective water absorption capacity is reduced. In addition, in the existing modification process, the combination of the fiber and the polymer network is dependent on post-treatment crosslinking, the reaction controllability is poor, uneven crosslinking density distribution is easy to cause, and the reliability of the integral structure is affected. In summary, the existing high water absorbing material still has defects in terms of structural stability, interface bonding strength and functional synergy, and particularly, the comprehensive requirements of the paper diaper on high-speed absorption, high liquid retention and low rewet under a dynamic pressure scene are difficult to meet. Disclosure of Invention In view of the above, the invention aims to provide a super absorbent fiber, a preparation method and application thereof in paper diapers, so as to solve the problems that the liquid retention rate of the water absorbent resin for the existing paper diapers is obviously reduced under the pressure of a human body or the movement extrusion, and the interface combination of a fiber base material and a water absorbent polymer is weak, so that the absorption performance is attenuated and the moisture regain is aggravated after repeated compression, and the high-speed absorption and the long-term water locking are difficult to achieve. Based on the above object, the present invention provides a method for preparing a super absorbent fiber, comprising the steps of: (1) Carrying out aminolysis modification on polyester fibers by adopting allylamine to obtain allylamine modified polyester fibers; (2) Contacting allylamine modified polyester fiber with an inner layer monomer system, and initiating in-situ crosslinking graft polymerization under illumination in an inert atmosphere to obtain a grafted fiber intermediate; (3) Placing the grafted fiber intermediate in a treatment solution containing calcium salt for treatment, so that divalent calcium ions and carboxyl groups of an inner layer form ion crosslinking, and performing semi-drying treatment to obtain semi-dried fibers; (4) And (3) contacting the semi-dry fiber with an outer monomer system, initiating in-situ crosslinking graft polymerization by illumination under inert atmosphere, and washing and drying after polymerization to obtain the super absorbent fiber. Preferably, in the step (1), the aminolysis modification is performed in absolute ethyl alcohol, and after allylamine and absolute ethyl alcohol are prepared into