Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Rod – strand – filament or fiber
Reexamination Certificate
2000-12-07
2003-02-04
Edwards, Newton (Department: 1774)
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Rod, strand, filament or fiber
C428S393000, C428S375000
Reexamination Certificate
active
06514610
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for manufacturing improved regenerated cellulose fiber with improved swelling in water and fibrillation character, which are intrinsic defects of regenerated cellulose fiber, together with superior handling. Improved regenerated cellulose fiber obtained by the present invention is utilized in wide application fields as yarn, woven and knitted fabrics, non-woven fabric and paper, exhibiting these performances.
2. Description of the Related Art
Regenerated cellulose fiber such as rayon and polynosic is composed of cellulose like natural fibers such as cotton and hemp, and has been an indispensable material in clothing field thanks to its superior moisture absorbing property and biodegradability. However, regenerated cellulose fiber, in particular rayon, has defects of poor stiffness and resilience, although superior in soft handling and draping. In addition, it has further defects such as poor water resistance leading to high degree of swelling in water and shrinkage percentage after washing and whitening due to fibrillation. Polynosic fiber have been developed to largely improve these properties of rayon and attained a certain level of improvement. However, the fiber is not sufficient in water resistance and stiffness compared with natural cellulose fibers such as cotton and hemp.
In order to eliminate these defects, treatments of regenerated cellulose fiber with a crosslinking agent have been tried since before. JP-A-59-94681, for example, discloses a method for crosslinking treatment of woven and knitted fabrics containing cellulose fiber with an epoxy crosslinking agent to obtain wash-and-wear and crease resistant characters. JP-B-10-237765 also discloses a method for improving handling by treating an artificial cellulose fiber or it's fabric with polyethylene glycol and an epoxy compound. However, in crossliking of regenerated cellulose fiber, treatment with a crosslinking agent after formation of cellulose fiber leads to a formation of crosslinks only in the vicinity of fiber surface because crosslinking agent hardly penetrate into an inner part of the fiber, and it results in an insufficient suppression of degree of swelling in water and a poor stiffness in physical properties, although fibrillation can be certainly suppressed.
JP-A-9-170126 discloses a method for a heat treatment of cellulose fiber yarn after contacting with formaldehyde vapor. This method enables a hydrophobic crosslinking agent of low molecular weight such as formaldehyde to penetrate into a fiber to form crosslinks in an inner part of a fiber, and thus to reduce fibrillation, suppress swelling and improve crease resistance. However, the method has defects such as reduction of moisture absorption which is an intrinsic superior performance of regenerated cellulose fiber, and lowering of strength. Use of increased amount of a crosslinking agent to improve degree of swelling and physical properties may attain improvement of degree of swelling, but is apt to cause defects such as stiffening of fiber, lowering of fiber strength and facilitated fibrillation.
As a method to promote a reaction of a crosslinking agent inside a fiber by performing the reaction during formation of a regenerated cellulose formed product, JP-A-11-187871, for example, discloses a method to drop a viscose solution into a coagulation bath then take out it and react with a crosslinking agent before completion of coagulation and regeneration. This method needs to take out a formed product in the way of coagulation in order to promote a reaction with a crosslinking agent inside a fiber. Thus, in an application to a fiber, it is difficult to apply to polynosic, although applicable to rayon with a skin-core structure. Furthermore, it is not practical to be applied to a continuous production process particularly for fiber, due to a difficulty in controlling a coagulation process.
BRIEF SUMMARY OF THE INVENTION
Object of the present invention is to provide a method for manufacturing improved regenerates cellulose fiber having reduced swelling in water, which is a defect of regenerated cellulose fiber, and superior handling, along with suppressed generation of fibrillation, by eliminating the defects described above.
Another object of the present invention is to provide an improved regenerated cellulose fiber and products obtained therefrom.
The inventor, after thorough studies to solve the defects described above, found out that fibrillation, swelling in water, shrinkage percentage after repeated washings and low stiffness, which were big defects of regenerated cellulose fiber, could be improved without reductions of strength and moisture absorption or deterioration in handling, by adding a crosslinking agent to a cellulose viscose solution then extruding the solution into a coagulation and regeneration bath, or by treating with a crosslinking agent solution again after spinning similarly as described above, and thus reached the present invention.
The present invention is a method for manufacturing improved regenerated cellulose fiber, by adding a crosslinking agent having two or more reactive functional groups in a molecule to a cellulose viscose solution and mixing, then extruding the viscose solution into a coagulation and regeneration bath, followed by applying a heat treatment. The present invention is also a method for manufacturing improved regenerated cellulose fiber, by adding a crosslinking agent having two or more reactive functional groups in a molecule to a cellulose viscose solution and mixing, then extruding the viscose solution into a coagulation and regeneration bath, followed by contacting thus obtained regenerated cellulose fiber with an aqueous solution of a crosslinking agent having two or more reactive functional groups in a molecule then applying a heat treatment. The present invention is further a method for manufacturing improved regenerated cellulose fiber, wherein the crosslinking agent used is an epoxy-based crosslinking agent, and still further a method for manufacturing improved regenerated cellulose fiber, wherein the amount of a crosslinking agent added to a cellulose viscose solution is 1-15% by weight to cellulose in a cellulose viscose solution. The present invention is furthermore a methods for manufacturing improved regenerated cellulose fiber, wherein the concentration of an aqueous solution of a crosslinking agent to be contacted with regenerated cellulose fiber after spinning is 1-10%.
Moreover, the present invention is a method for manufacturing improved regenerated cellulose fiber, wherein fine particles of mixed-in additives are added to a cellulose viscose solution and mixed in addition to a crosslinking agent, and furthermore is a method for manufacturing improved regenerated cellulose fiber, wherein the said mixed-in agent described above is fine granular chitosan.
Furthermore, the present invention is an improved regenerated cellulose fiber and products obtained therefrom.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
A crosslinking agent added to a cellulose viscose solution in the present invention is a compound having two or more reactive functional groups in a molecule, and preferably the reactive functional groups are glycidyl ether group or chlorohydrin group. Typical examples include those having two or more reactive functional groups in a molecule comprising ethyleneglycol types such as ethyleneglycol diglycidyl ether and polyethyleneglycol diglycidyl ether and propyleneglycol types such as propyleneglycol diglycidyl ether and polypropyleneglycol diglycidyl ether and the like. Epoxy-based crosslinking agents having three or more reactive functional groups such as glycerol glycidyl ether may also be used without any problem. Chlorohydrins before cyclization to epoxy compounds may also be used as a crosslinking agent of the present invention without any problem because these compounds are immediately cyclized to epoxy compounds due to an action of sodium hydroxide contained in
Itoyama Koki
Kakizaki Kikuo
Mitsuhashi Masaki
Tanibe Hiroaki
Birch & Stewart Kolasch & Birch, LLP
Edwards Newton
Fuji Spinning Co., Ltd.
LandOfFree
Method for manufacturing improved regenerated cellulose fiber does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for manufacturing improved regenerated cellulose fiber, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for manufacturing improved regenerated cellulose fiber will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3175764