JPH06502225A - Method of mixing additive solution into para-aramid dope stream - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] A method of mixing additive solutions into a para-aramid dope stream The present invention has a relatively high The viscous liquid crystalline fiber spinning dope and the low viscosity additive solution flow are continuously Concerning mixing. More specifically, the present invention relates to liquid crystalline liquids exhibiting relatively high viscosity. A stream of low viscosity additive solution is continuously mixed into a spinning dope stream for spindle aramid. Together, they relate to producing modified spinning dopes. This modified spinning The dope contains colorants, ultraviolet (UV) light shielding agents, antioxidants, plasticizers, flame retardants, and High strength and high modulus, uniformly modified with additives such as other property-enhancing materials It can be used for the purpose of spinning para-aramid fibers.

Description of prior art As described in Blades U.S. Patent No. 3.869.429, Methods for producing high modulus aramid fibers are known. however, Produces high strength, high modulus para-aramid fibers with uniform distribution of additives It is extremely difficult to do so.

British Patent No. 1.438.067 to Mulds et al. By soak-spinning (terephthalamide) fibers and placing them in a coagulation bath, water-swellable fibers are produced. After formation, treatment of these fibers with an aqueous impregnant solution is disclosed.

This document (Ki [antioxidants, ultraviolet (UV) light shielding agents, dyes, flame retardants and antistatic agents] discloses the use of an impregnating agent selected from the group consisting of antistats. Ru.

Milford, h., U.S. Pat. After the fibers are wet-spun, this wet but not dry It is disclosed that the fibers are treated with an aqueous mixture of ultraviolet (UV) light screening agents. .

U.S. Patent No. 4.070.342 to Lazarus et al. Liquid polyisobutylene is added to the feed line carrying the tallate polymer melt. A method of injecting a dispersion of polymer additives in a polymer is disclosed. Then this poly The above dispersion and polymer are mixed in a stationary mixer just before the polymer passes through the spinning block. – is mixed with the melt.

Gray, U.S. Patent No. 4.068.830, describes Water, a low viscosity liquid, is injected into the syrup stream near the center of the flow pipe. and then, after passing the liquids through the perforated plate, they are placed in a static microplate. A method of mixing in a kisser is disclosed.

A co-pending and co-assigned U.S. patent application filed by Lee on August 1, 1988. Application serial number 07/226.645 includes colored high strength, high modulus roses. - aramid fibers and (1) organic pigments, sulfuric acid and para-aramid polymers; Stir the mixture, (2) heat the mixture, and (3) pass the solution through a spinneret. (4) passing this extrudate through an aqueous coagulation bath; (5) this new washing the shaped filament with water and/or alkali; A method of manufacturing the above fiber is disclosed.

L or L 1. The above-mentioned literature describes the spinning of liquid crystalline fibers with relatively high viscosity. Injecting a low viscosity additive solution stream into the dope stream is not disclosed. stomach. There is no significant difference between the anisotropic spinning dope and the isotropic spinning solution or melt. exists. For example, anisotropic spinning dope has the property of exhibiting high crystallinity. It is difficult for the additives to penetrate due to the There is a need for a method for uniformly mixing these.

Summary of the invention The present invention utilizes liquid crystalline fiber spinning dope exhibiting relatively high viscosity and low viscosity additive solution flow. This provides a method for continuously mixing.

Additive solution streams with viscosities ranging from 5 to 100 centipoise at 50°C, preferred has an organic pigment solution flow and a viscosity ranging from 500 to 5000 poise at 80°C. A spinning dope stream of liquid crystalline para-aramid is prepared. Preferably, this parameter The aramid spinning dope stream is poly(p-phenylene terephthalamide). the After that, the additive solution stream is continuously introduced into the center of the para-aramid spinning stream. Ru. Thereafter, at least one stationary mixing element is provided. and has a length to diameter ratio of at least 5. atic) Mix the streams homogeneously in a mixer device. Preferably, this step Tatic mixer equipment is equipped with 2 to 4 fixed mixing elements and The length to diameter ratio ranges from 10 to 20. para-aramid dope The volume flow ratio of additive solution flow to flow ranges from 0.001 to 0. within the range of 4 viscosity ratio of the spinning dope stream to the additive solution stream is from 500 to 10 It is in the range of 0.000.

detailed description of the invention The present invention utilizes a liquid crystalline barararamid spinning dope exhibiting relatively high viscosity and a low viscosity additive. Concerning continuous mixing with additive solution. Using this spinning dope, it is highly modified with additives. It is possible to spin high-strength, high-modulus para-aramid fibers that are .

First, an additive solution is prepared using techniques known in the art. These additive solutions The liquid may contain organic pigments, ultraviolet (UV) light shielding agents, antioxidants, plasticizers, flame retardants, etc. and other property-enhancing materials may be included with minimal transfer time. Preferably, this The additive solution is an organic pigment solution, and the pigment consists of (1) monoazo and di- Azo pigment, (2) Anthanthrone pigment, (3) Idanthrone pigment, (4) Biran thoron pigment, (5) vilanthrone pigment, (6) flavanthrone pigment, (7) cinchona Cridone pigments, (8) dioxazine pigments, (9) indigoids and thioindigoids (10) isoindolinone pigments; and (10) isoindolinone pigments. At least one.

A preferred monoazo pigment is Color Index Pigment Red 3. Suitable diazo pigments have a color index face The color is Red 242. A preferred anthanthrone pigment has a color index of Pigment Red 168. be. A preferred idanthrone pigment is Color Index Pigment Blue 60. preferred virant The Ron pigment has a Color Index Pigment Orange 40.

A preferred vilanthrone pigment is Color Index Pigment Blue 65. Suitable flavanthrone The pigment is Color Index Pigment Yellow 24. Suitable quinacridone pigments have a color index pigment level. This is the head 122. A preferred dioxazine pigment is Color Index Pigment Violet 23. Ru. Suitable indigoid and thioindigoid pigments each have a color index pigment label. Pigment Red 88 and Color Index Pigment Red 86. Suitable isoinnic pigments have color index It is Pigment Yellow 173.

The organic pigments shown above are from the five societies of Dyers and The Co1or Index published by Co1ourists ) is the name of the raw material called.

Pure organic pigments suitable for use in the present invention are compatible with sulfuric acid at a concentration of at least 98%. soluble, but insoluble in water or organic solvents, and in 98% sulfuric acid at 95°C. Even if it is kept at this temperature for 3 hours, it does not deteriorate to the extent that it can be detected. Pigment deterioration Instructions include color changes in the final fiber, pigment bleed into the coagulation bath, and spinning dome. Contains pigment precipitation from the pipe.

With different pigments, different colored solutions can be produced and used The amount of pigment used depends on the type of pigment and the degree of color desired. however Generally, pigment levels range from 0.01 to 6.0% based on the total weight of the fiber. should be within the range of All additive solutions were tested at 50°C for approximately 5 to 100 cm. It should have a viscosity in the poise range.

The para-oriented aromatic polyamides (para-aramids) useful in the present invention are U.S. Pat. No. 3.869., in which a hard group is linked into a polymer chain by a do group. 429. The chain extension bond of this rigid group is coaxial Or parallel, and vice versa. These hard groups can be monocyclic groups or A polycyclic group, which is a fused ring group in which the extending bonds are oriented in para, or a heterocyclic group; Good too. Suitable hard groups are 1,4-phenylene, 2,6-naphthalene, 1,5- Naphthalene, 4,4° ~ biphenylene, trans-1,4-cyclohexylene , trans-trans-4,4'-eL cycloxylene, and trans-vinyl 1,4-pyri linked together by lene, ethynylene, azo or iyoazoquino groups. It's Dajin. These polyamides contain intervening molecules such as chloro groups and methyl groups. It may be substituted with a group. As long as these hard groups are as defined above, the Both mopolymers and copolymers are suitable. 5 mole percent or less Non-tunable groups may also be included. These polyamides are LiCL or CaC 1, in a non-reactive amide solvent which may contain a solubilizing salt such as It can be prepared by reacting an acid halide with a suitable aromatic diamine. Ru. The intrinsic viscosity of this polyamide should be less than 4.

The para-aramid polymer is then mixed with cold sulfuric acid having a concentration of at least 98%. In addition, it produces a dope with a low para-aramid concentration (both 18%) when heated. make you feel the same The dope is heated to 80 DEG-105 DEG C. without stirring and then degassed.

The holding time of this dope can be 1 to 3 hours in commercial spinning processes. this liquid The crystalline spinning dope stream has a viscosity ranging from 500 to 5000 poise at 80 °C Should. Preferably, the liquid crystalline spinning dope stream is made of poly(p-phenylene terres). phthalamide).

Next, in the standard commercial spinning process, a liquid crystalline rose-aramid spinning dope is The additive solution stream is introduced continuously on-line. This additive solution flow is Conveniently use a positive displacement pump and apply injection pressures ranging from 200 to 1500 pS/g. This additive solution may be introduced into the spinning dope in the center of the spinning dope. It is important to introduce Additive solution for para-aramid spinning dope flow The volumetric flow ratio of the liquid flow ranges from 0.001 to 0. Range of 4 → should. Additive The viscosity ratio of the para-aramid spinning dope flow to the solution flow is 500 to 100. ．． Should be in the range 000. Next, combine these streams with a static mixer. Mix together in the apparatus. Static mixer devices suitable for the present invention include There is at least one stationary mixing element arranged vertically within the tube.

These mixing elements or elements mix the component streams until one uniform stream is obtained. resulting in intersecting channels that split, rearrange, and recombine the let

This static mixer device thoroughly mixes high viscosity and low viscosity flows. You need to be able to do that. at least one fixed mixing element and Static mixer device having a length to diameter ratio (L/D) of at least 5 is required, and where L is the length from the inlet to the outlet of this mixer device. and D is its diameter. Equipped with 2 to 4 fixed mixer elements and a static mixer device with an L/D ratio in the range of 10 to 20. suitable. When the above flow passes through this static mixer device, the There should also be a pressure drop of 50 psig and less than 500 psig. Lower is more desirable. Equipped with at least one fixed rSMXJ mixing element. and an rsMXJ static mixer device with an L/D ratio of 5. This is Koch Engineering Company, Inc. It is available from Each r S M and this is an oven cross channel at 45 degrees to the axis of the vibrator. It has open intersecting channels.

These mixing elements include carbon steel, stainless steel, rMonelJ, ``^1oyJ 20, Titanium, Hastelloy J, Polyethylene, Porapropylene, rT It may be made of materials such as eflonJ or rKynarJ.

The spinning dope stream is then extruded through a spinneret using techniques known in the art. , collected, washed, and then dried to ensure high strength that is uniformly modified with additives. yields high modulus para-aramid fibers at low temperatures. This word high strength means tenacity Yarn having a strength of at least 18 gpd (15,9 dN/t e X) or It means filament. The above term high modulus means that the modulus is at least also means a thread or filament that is 400gpd (354dN/1ex) ing. In the examples below, parts, proportions and parameters are used, unless otherwise specified. -cent is weight.

Example 1 A pigment solution was prepared as follows.

Add 5 andoz Chemical to 95 parts of 100% concentrated sulfuric acid in a mixing container at room temperature. 5a, a pigment in the respective ratio 15/310.5, available from alCo ndorin blue RL (pigment blue 60) / 5andorin scarlet 4RF (Pigment Red 242) / 5andorin Yellow (Pigment Yellow 24) is included! Pigment powder mixture 5 andorin yellow VRL 5 Added part. The above mixture is stirred until the pigment powder mixture is completely dissolved in the sulfuric acid. Stirred. This pigment solution is then passed through the filter and online as a stream. Circulated through a pressure control valve and pumped to 800 psig using a positive displacement pump. The bara-aramid spinning dope was injected into the center of the flow under pressure.

This spinning dope stream contains 19.5% poly(p-phenylene terephthalate) in sulfuric acid. c) It was a solution. In 80.5 parts of 100% concentrated sulfuric acid at a temperature of 85℃, the intrinsic viscosity is 195 parts of 6 glue (p-phenylene terephthalamide) polymer were completely dissolved. Thereafter, the above-mentioned spinning dope was prepared by deaerating this dope. Above temperature This spinning dope flow had a liquid crystal structure.

Next, separate rSMXJ mixing elements with length to diameter (L/D) ratio of 5 rSMXJ static mixer equipment equipped with four It was. The length of this static mixer device is 20 inches and the internal diameter is 0. 62 inches, outside diameter is 0.84 inches, and overall/D ratio is 20 Met. The above equipment is manufactured by Koch Engineering Company. Available from Inc. The volumetric flow ratio of pigment solution flow to spinning dope flow is 1 :25, that is, 0.04. Spinning dope flow vs. pigment solution flow at 85°C The viscosity ratio was 1000 voids to 5 centipoise, or 20.000. the above There is a pressure drop of 120 psig as the stream passes through the static mixer device. It was.

This mixed stream is then fed into a metering pump and a 0.063 mm diameter Extrusion through a 1000-hole spinneret equipped with capillaries Finally, the water coagulation group at 5°C was injected through an air gap with a length of 0.7 cm. I put it inside. In this air gap, the extruded dope is transferred to its original length. It was enlarged 6.3 times. The resulting fibers are further treated with dilute alkaline aqueous solution and water. After washing with water and drying on a roll at 180°C, it was wound up at 713 m/min. this The amount of pigment was 1% based on the total weight of the fibers.

The fiber obtained in this example was completely coated with the coloring agent over its entire cross section. the pigment solution through the side of the static mixer device (not in the center of the flow A similar operation as described in Example 1 was performed, except that a liquid stream was injected into the spinning dope stream. I made the work. The fibers could not be spun due to continuous dripping from the spinneret. I couldn't. Such dripping occurs when the pigment solution flow This was thought to be the result of complete separation from the group.

Example 2 By removing two rsMXJa coupling elements, the L/D of the static mixer device The same procedure as described in Example 1 was carried out except that the ratio was reduced from 20 to 10. Ta. This fiber, like the fiber of Example 1, exhibited a uniform colorant distribution.

Comparative Example 2 As described in Example 2 except that all mixing elements in the static mixer apparatus were removed. Colored fibers were produced using a method similar to that described.

The spun fiber exhibits striations along its axis, which indicates that the pigment This suggested very inhomogeneous mixing of the solution and the para-aramid dope.

Copy and translation of corrected sound) Submission form (Article 184-8 of the Patent Law) April 12E, 1993 I

Claims (6)

[Claims] 1. (a) an additive solution having a viscosity ranging from 5 to 100 centipoise at 50°C; prepare the flow, (b) Liquid crystalline para-acid having a viscosity in the range of 500 to 5000 poise at 80°C preparing a spinning dope stream of lamid; (c) continuously adding the additive solution stream to the spinning dope stream; The crystalline para-aramid spinning dope is introduced into the center of the dope stream, where the dope stream is The volume flow ratio of the additive solution flow ranges from 0.001 to 0.4, and The viscosity ratio of the dope stream to the additive solution stream is from 500 to 100, 000 range, and (d) is provided with at least one fixed mixing element and has a length to diameter ratio; is at least 5, the core additive solution stream and the liquid Crystalline para-aramid spinning dope exhibits high viscosity, including the step of mixing with the flow A method of mixing a low viscosity additive solution stream into a liquid crystal fiber spinning dope stream. 2. 2. The method of claim 1, wherein said additive solution stream is a pigment solution. 3. The para-aramid spinning dope is poly(p-phenylene terephthalamide). The method according to claim 1. 4. The additive solution is a pigment solution and the para-aramid spinning dope is a poly( p-phenylene terephthalamide). 5. The static mixer device has from 2 to 4 fixed mixing elements. 2. The method of claim 1, wherein the length to diameter ratio is in the range of 10 to 20. 6. The static mixer device has from 2 to 4 fixed mixing elements. 5. The method of claim 4, wherein the length to diameter ratio is in the range of 10 to 20.