Toyo Boseki Kabushiki Kaisha

Dsm N.v.

Yasuo Ohta

Godo Sakamoto

Tooru Kitagawa

Syoji Oda

Takuya Konishi

Hisato Kobayashi

Tadao Kuroki

Yukihiro Nomura

Masahiko Nakamori

Takayoshi Okano

Tadayo Miyasaka

Junichi Nakahashi

Yoshinobu Oie

Rajen M Patel

Satoshi Maeda

Antonio Batistini

Yasunori Fukushima

Hiroki Murase

Katsuya Shimeno

Rona L Reid

Akira Hamano

Akira Nishimoto

Nobuyuki Taniguchi

Daisuke Sakura

Seishyu Hayashi

A non-woven fabric which is excellent in thermal resistance, mechanical strength, and thermal dimensional stability for applications exposed to high temperature circumstance and has an extremely large surface area and exhibit an excellent filter performance is obtained. The non-woven fabric is composed of polyimide fibers which are obtained by polycondensation of at least an aromatic tetracarboxylic acid and an aromatic diamine having a benzoxazole structure and have a fiber diameter in the range of 0.001 &#x3bc;m to 1 &#x3bc;m. The non-woven fabric is obtained by the steps of preparing a polyamic acid by polycondensation of an aromatic tetracarboxylic acid and an aromatic diamine having a benzoxazole structure, and electro-spinning the polyamic acid to form a polyimide precursor non-woven fabric; and imidizing a polyimide precursor fiber bundle.

Polyimide nonwoven fabric and process for production thereof

The present invention provides a fiber having a nano-order fiber diameter, which is produced by without a process of dehydration and cyclization by a heat treatment after fiber spinning and has excellent heat resistance and mechanical strength, and a non-woven fabric composed of the fiber, and discloses the polyamide-imide fiber and the non-woven fabric having an average fiber diameter of from 0.001 &#x3bc;m to 1 &#x3bc;m and also discloses the process for producing threrof. The present invention also provides a separator for an electronic component which has a high conductivity and a small separator thickness and is improved in safety during reflow soldering or short-circuiting, and discloses the separator composed of a non-woven fabric obtained by an electro-spinning method.

Polyamide imide fiber, non-woven fabric composed of the fiber, process for manufacture of the non-woven fabric, and separator for electronic component

To provide a novel high strength polyethylene multifilament which consists of a plurality of filaments having high strengths and uniform internal structures, and showing a narrow variation in the strengths of the monofilaments, and which has been difficult to be provided by the conventional gel spinning method. A high strength polyethylene multifilament consisting of a plurality of filaments which are characterized in that the crystal size of monoclinic crystal is 9 nm or less; the stress Raman shift factor is &#x2212;5.0 cm/(cN/dTex) or more; the average strength is 20 CN/dTex or higher; the knot strength retention of each monofilament is 40% or higher; CV indicating a variation in the strengths of the monofilaments is 25% or lower; the elongation at break is from 2.5% inclusive to 6.0% inclusive; the fineness of each filament is 10 dTex or less; and the melting point of the filaments is 145&#xb0; C. or higher.

High strength polyethylene fiber

The elastic fabric comprising a cross-linked polyolefin fiber, wherein the fabric has retractions both in warp-wise and weft-wise directions of the fabric of 8% or less after treated by dry heat at 65&#xb0; C. for 30 minutes is disclosed. Also disclosed is a process for producing an elastic fabric, comprising: retracting a fabric comprising a cross-linked polyolefin fiber while dyeing the fabric, and then stretching or relaxing the fabric at a stretch ratio of 15% or less to finish the fabric with heat-setting. The present invention relates to an elastic fabric having an excellent chemical resistance and an excellent dimensional stability in the form of a product, which is suitably used for sporting fabrics such as swimming suits, leotards and the like, inner fabrics for ladies as well as outer fabrics, for example.

Elastic fabric and process for producing the same

A high strength polyethylene filament, wherein said filament has a fineness of 1.5 dtex or less as a monofilament, a tensile strength of 15 cN/dtex or more and a tensile elastic modulus of 300 cN/dtex or more, and, the rate of dispersion-defective fibers cut from the filament is 2% or less, is disclosed, and a high strength polyethylene filament, wherein said filament has a tensile strength of 15 cN/dtex or more and a tensile elastic modulus of 300 cN/dtex or more, and, a long period structure of 100 &#x212b; or less is observed in an X-ray small angle scattering pattern is disclosed.

High strength polyethylene fibers and their applications, for example, chopped fibers, ropes, nets, ballistic materials or items, protective gloves, fiber reinforced concrete products, helmets, and other products obtained therefrom, in which the fiber is characterized in that: it contains a high molecular weight polyethylene consisting essentially of a repeating unit of ethylene; it has an intrinsic viscosity number of 5 or larger and an average strength of 22 cN/dtex or higher; and the measurement of the fiber by differential scanning calorimetry (DSC) exhibits a temperature-increasing DCS curve having at least one endothermic peak over a temperature region of 140&#xb0; C. to 148&#xb0; C. (on the low temperature side) and at least one endothermic peak over a temperature region of 148&#xb0; C. or higher (on the high temperature side) or the number of frictions until the fiber is broken in an abrasion test according to method B for measuring abrasion resistance in the Testing Methods for Spun Yarn (JIS L 1095) is 100,000 or larger.

High strength polyethylene fibers and their applications

High strength polyethylene fibers and their applications, for example, chopped fibers, ropes, nets, ballistic materials or items, protective gloves, fiber reinforced concrete products, helmets, and other products obtained therefrom, in which the fiber is characterized in that: it contains a high molecular weight polyethylene consisting essentially of a repeating unit of ethylene; it has an intrinsic viscosity number of 5 or larger and an average strength of 22 cN/dtex or higher; and the measurement of the fiber by differential scanning calorimetry (DSC) exhibits a temperature-increasing DCS curve having at least one endothermic peak over a temperature region of 140&deg; C. to 148&deg; C. (on the low temperature side) and at least one endothermic peak over a temperature region of 148&deg; C. or higher (on the high temperature side) or the number of frictions until the fiber is broken in an abrasion test according to method B for measuring abrasion resistance in the Testing Methods for Spun Yarn (JIS L 1095) is 100,000 or larger.

The invention relates to high-strength polyethylene fibers of mainly ethylene component having an intrinsic viscosity &lsqb;&eegr;&rsqb;, when fibrous, of no less than 5, and having a strength of no less than 20 g/d and an elasticity modulus of no less than 500 g/d, and, in the measurement of the temperature variance of the dynamic viscoelasticity of the fibers, the &ggr; dispersion loss modulus peak temperature is no greater than &minus;110&deg; C. and the loss tangent (tan &dgr;) is no greater than 0.03. The invention further relates to a method for producing high-strength polyethylene fibers, wherein a polymerization mixture containing from 99 to 50 parts by weight of (A) and from 1 to 50 parts by weight of (B), where (A) is high molecular weight polymer of mainly ethylene component and having a weight average molecular weight to number average molecular weight ratio (Mw/Mn) of no greater than 4 and an intrinsic viscosity &lsqb;&eegr;&rsqb; of no less than 5, and (B) is an ultrahigh molecular weight polymer having an intrinsic viscosity at least 1.2 times that of high molecular weight polymer (A), is dissolved in solvent to a concentration of from 5% by weight to 80% by weight, then spun and drawn.

Process of making high-strength polyethylene fibers

The invention relates to high-strength polyethylene fibers of mainly ethylene component having an intrinsic viscosity &lsqb;&eegr;&rsqb;, when fibrous, of no less than 5, and having a strength of no less than 20 g/d and an elasticity modulus of no less than 500 g/d, and, in the measurement of the temperature variance of the dynamic viscoelasticity of the fibers, the &ggr; dispersion loss modulus peak temperature is no greater than &minus;110&deg; C. and the loss tangent (tan &dgr;) is no greater than 0.03. The invention further relates to a method for producing high strength polyethylene fibers, wherein a polymerization mixture containing from 99 to 50 parts by weight of (A) and from 1 to 50 parts by weight of (B), where (A) is high molecular weight polymer of mainly ethylene component and having a weight average molecular weight to number average molecular weight ratio (Mw/Mn) of no greater than 4 and an intrinsic viscosity &lsqb;&eegr;&rsqb; of no less than 5, and (B) is an ultrahigh molecular weight polymer having an intrinsic viscosity at least 1.2 times that of high molecular weight polymer (A), is dissolved in solvent to a concentration of from 5% by weight to 80% by weight, then spun and drawn.

There is disclosed a high-tenacity polyethylene fiber containing an ethylene component as a main repeating unit, the fiber exhibiting an intrinsic viscosity [.eta..sub.B ] of at least 7 and having a tenacity of at least 30 g/d and an elastic modulus of at least 900 g/d; the peak value of loss tangent in the .gamma.-dispersion being 0.025 to 0.06 and the peak temperature of loss modulus in the .alpha.-dispersion being 85.degree. C. or higher, as determined by measurement of temperature dispersion of viscoelastic properties of the fiber. Also disclosed is a process of producing such a high-tenacity polyethylene fiber.

LBT process of making high-tenacity polyethylene fiber

There is disclosed a high-tenacity polyethylene fiber containing an ethylene component as a main repeating unit, the fiber exhibiting an intrinsic viscosity [.eta..sub.B ] of at least 7 and having a tenacity of at least 30 g/d and an elastic modulus of at least 900 g/d; the peak value of loss tangent in the .gamma.-dispersion being 0.025 to 0.06 and the peak temperature of loss modulus in the a-dispersion being 85.degree. C. or higher, as determined by measurement of temperature dispersion of viscoelastic properties of the fiber. Also disclosed is a process of producing such a high-tenacity polyethylene fiber.

Growing community of inventors

Otsu, Japan

Yasuo Ohta