Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Rod – strand – filament or fiber
Patent
1994-10-24
1996-05-07
Edwards, N.
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Rod, strand, filament or fiber
428395, D02G 300
Patent
active
055144713
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a high-tenacity polyamide fiber. More particularly, it relates to a high-tenacity polyamide fiber which is characterized as, when it is embedded in rubber as a reinforcing fiber and the rubber is vulcanized, exhibiting tenacity reduction only to a minor extent and yielding a vulcanized cord having a high tenacity.
BACKGROUND ART
Polyamide fibers have good toughness, adhesion, fatigue resistance and other properties, and are widely used as industrial materials. Of polyamide fibers, a polyhexamethylene adipamide fiber is especially suitable for products which are used under severe conditions or for which a high quality is required. Excellent dimensional stability to high temperature and thermal resistance of this fiber is utilized in the step of processing the fiber for the manufacture of the products.
It is always required that industrial products are light-weight and thus it is important that the amount of reinforcing fibers contained in the industrial products is minimized without substantial reduction of the reinforcing performance. For satisfying this requirement, fibers having a higher tenacity have been eagerly desired and many attempts of developing high-tenacity fibers have heretofore been made. With regard to polyamide fibers, proposals of making high-tenacity polyamide fibers were made, for example, in Japanese Unexamined Patent Application No. 1-168913 and Japanese Unexamined Patent Publication No. 3-241007.
Namely, a high-tenacity polyhexamethylene adipamide fiber having a special structure defined by specific fiber structural properties is described in Japanese Unexamined Patent Application No. 1-168913. This fiber is characterized by the following features (a) through (f) as compared with conventional polyhexamethylene adipamide fibers: larger, obtained by a dynamic viscoelastic measurement is lower, and perfection of crystal is higher.
In other words, the high-tenacity polyhexamethylene adipamide fiber has a fiber structure capable of developing a high tenacity, i.e., features (a) and (b), as well as a fiber structure capable of developing stability against mechanical functions, i.e., features (d), (e) and (f). More practically, this fiber has a high-tenacity, a good dimensional stability to high temperature, a good tenacity-maintenance after vulcanization and a good fatigue resistance.
The above-mentioned high-tenacity polyhexamethylene adipamide fiber is made by a process characterized by the combination of a spinning at a high rate and a heat drawing at a relatively low rate. Namely, a spinning at a high rate is employed for developing the features (d), (e) and (f) and a heat drawing at a relatively low rate is employed for developing the features (a), (b) and (c). By a high speed spinning, a stable structure can be easily obtained but a high-tenacity structure is difficult to obtain. This problem is solved by combining the heat drawing at a relatively low rate with the high speed spinning in the process.
The above-mentioned high-tenacity polyhexamethylene adipamide fiber has a high tenacity, e.g., 12.5 g/d as specifically described in the working examples, but has a very low elongation, e.g., 12.0%. Further, the excellent toughness inherently possessed by a polyhexamethylene adipamide fiber is lowered in this fiber.
In Japanese Unexamined Patent Publication No. 3-241007, a polyamide fiber having a low shrinkage, a high modulus and a very high toughness, and a process for making the same are described. This polyamide fiber is characterized by the following structural features (a) through (h):
The polyamide fiber has a toughness of at least about 11.0 g/d, a dry heat shrinkage at 160.degree. C. of at least 6.5%, a modulus of at least about 35 g/d and a sound-wave modulus of at least 90 g/d.
This polyamide fiber is made by a process wherein a heat drawing is carried out under conditions such that the fiber temperature is at least 185.degree. C. and the residence time is about 0.05 to about 1 second, and then the heat-drawn fiber is subjected to a
REFERENCES:
patent: 4542063 (1985-09-01), Tanji et al.
patent: 4732720 (1988-03-01), Tanji et al.
patent: 4987030 (1991-01-01), Saito et al.
patent: 5302452 (1994-04-01), Kai et al.
patent: 5341632 (1994-08-01), Jung et al.
patent: 5405697 (1995-04-01), Chaubet et al.
Nagahara Hideo
Okano Ryoji
Saito Isoo
Tuduki Michikane
Edwards N.
Miller Austin R.
Toray Industries Inc.
LandOfFree
High-strength polyamide 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 High-strength polyamide fiber, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-strength polyamide fiber will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1225862