JPH0437182B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing fibers using composite fiber technology. More specifically, it is an ultrafine fiber-generating composite fiber made of two or more component polymers, which can be easily obtained, and which can be treated to avoid environmental contamination or pollution when draining the solution containing the removed components. It concerns a method for producing fibers using textile technology. (Prior Art) Polystyrene and its modified products, polyamide, polyethylene, copolyester, etc. have conventionally been used as removal components of sea-island composite fibers. As removers for these components, trichlene, percrene,
Formic acid, toluene, alkali, etc. are used.
All of these removers are harmful and toxic substances, and great care must be taken when handling them. For this reason, a huge amount of investment has been made in chemical-resistant removal equipment, taking into consideration the safety of workers, work efficiency, and prevention of environmental pollution. Tricrene and percrene, which are polystyrene-based solvents that have traditionally been widely used due to their relatively low toxicity, have recently been reconsidered for their harmful effects on the human body, and strict regulations are being imposed on their use. Therefore, there is no guarantee that TriClene and PerClene will be able to be used together in the future. Furthermore, when an acid or alkali, which is a decomposing agent for polyester, is used as an aqueous solution, it is extremely difficult to recover the decomposed and removed polymer and to dispose of the solution. On the other hand, as a method for removing one component, the objective can be achieved without using these dangerous chemicals if the component is water-soluble. Conventionally known water-soluble polymers include PEG, PEO,
Examples include PVA. These polymers generally have poor thermal fluidity and heat resistance, and can only be made into fibers under very limited conditions when used alone. Therefore, to use it as one component of a composite fiber depends on the relationship with the characteristics of the other component polymers to be combined, and it is unsuitable from the viewpoint of melting point, compatibility, melt viscosity, etc. It is not used as a component of composite fibers. In addition, as a water-soluble polymer,
1373 are known. This method is advantageous in that it does not use chemicals. However, this polymer is poorly soluble in cold water and requires a long time in hot water to remove one component (in Example 2).
Soaked in 100℃ hot water for 1 hour. ), productivity is poor, and it is extremely difficult from a production point of view to continuously remove fabrics, etc. It also has the disadvantage of requiring multiple steps to recover the polymer, including evaporation concentration and cooling. (Problems to be Solved by the Invention) The present inventors have discovered that one component of an ultrafine fiber-generating composite fiber that does not have the above-mentioned drawbacks can be easily removed, and that the removed solution can be used to create a composite fiber that does not cause pollution or environmental concerns. As a result of intensive studies aimed at providing the following, the method of the present invention was arrived at. (Means for Solving the Problems) The present invention is a composite fiber consisting of at least two components, one of which has an amino group or a carboxyl group at the end of an easily soluble polyether segment having a molecular weight of 200 to 2000. 30 to 30 structural units consisting of component (A) of polyoxyethylene and component (B) of aliphatic dicarboxylic acid or aliphatic diamine.
A composite fiber containing 80% by weight of copolyamide and other components that are hardly soluble is used and subjected to hot water containing 0.1% by weight or more of an anionic surfactant. The present invention relates to a method for producing fibers, characterized in that the easily soluble components are removed by a process. At least one component constituting the composite fiber as referred to in the present invention
The copolymerized polyamide that makes up the component has a molecular weight of 200
30 to 80 weight structural units consisting of component (A) of polyoxyethylene having an amino group or carboxyl group at the end of the polyether segment portion of ~2000 and component (B) of aliphatic dicarboxylic acid or aliphatic diamine. It is a copolymerized polyamide containing %. Specifically, the copolyamide used in the present invention includes polyoxyethylene diamine or polyoxyethylene dicarboxylic acid, oxalic acid, succinic acid, glutaric acid, adipic acid, bimelic acid, speric acid, azelaic acid, sehacic acid, unte Aliphatic dicarboxylic acids such as candioic acid, dodecanedioic acid, diglycolic acid, ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,
4- and aliphatic diamines such as 2,4,4-trimethylhexamethylene diamine as main structural units. The number average molecular weight of the polyether segment of the polyoxyethylene diamine or polyoxyethylene dicarboxylic acid is 200.
~2000, preferably in the range of 300 to 1500; if the number average molecular weight is less than 200, the resulting polymer will be relatively brittle and cannot be dissolved in a solution prepared by adding an anionic surfactant to water. It becomes difficult. Moreover, if it exceeds 2000, the characteristics as polyamide will be lost and thread breakage will increase during spinning. In addition, in the present invention, the structural unit consisting of component (A) polyoxyethylene diamine or polyoxyethylene dicarboxylic acid and component (B) component aliphatic dicarboxylic acid or aliphatic diamine contained in the copolyamide is 30 to 80% by weight. Must be within the range. If it is less than 30% by weight, it is difficult to dissolve even in a solution using an anionic surfactant, which is not preferable. On the other hand, if it exceeds 80% by weight, it is preferable in terms of increasing water solubility, but it is not preferable because the thermal stability is poor, thread breakage occurs during spinning, and the polymer becomes expensive. The amide group-forming copolymerization component to be copolymerized with the unit consisting of polyoxyethylene diamine or polyoxyethylene dicarboxylic acid and aliphatic dicarboxylic acid or aliphatic diamine is not particularly limited and may be a commonly known one, such as ε-caprolactam,
ω-laurolactam, 6-aminocaprone, 11-
Lactams such as aminoundecanoic acid and 12-aminododecanoic acid, amino acids and the above-mentioned aliphatic diamines, aliphatic dicarboxylic acids, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis( 4,4'-aminocyclohexyl)methane, meta-xylylene diamine, para-xylylene diamine, cyclohexanedicarboxylic acid, isophthalic acid, terephthalic acid, 5-
Components selected from salts derived from common alicyclic, aromatic diamine, and dicarboxylic acid combinations such as sodium sulfoisophthalic acid can be used. Polyamide polymerization methods include melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization, solid phase polymerization, and combinations of these methods, with melt polymerization being generally the most suitable. As a method for producing ultrafine fiber-generating conjugate fibers, polymer array fibers having a sea-island cross section are preferred, and the number of islands may be selected depending on the thickness of the ultrafine fibers to be obtained. Suitable examples of the island component include any known fiber-forming, water-insoluble polymers. For example, polyethylene terephthalate, copolyester copolymerized with 5-sodium sulfoisophthalate, polyesters and modified products such as polybutylene terephthalate, polyamides such as nylon 6, nylon 66, and nylon 610, polyethylene,
There are polyolefins such as polypropylene.
Modifiers and additives for the purpose of preventing static electricity, improving dyeability, matting, antifouling, flame retardancy, etc. may be blended with these. The ratio of island component to sea component can be chosen arbitrarily. For example, island/sea=98/2 to 2/98% by weight, preferably 98/2 to 20/80% by weight. This is because it removes sea components, and if the amount is large, it is difficult to remove and it is also economically disadvantageous. The fiber containing this amide copolymer as a sea component has the following characteristics in addition to being easy to remove seawater. To make textiles from fibers, warps are usually twisted and glued to improve weavability. This is to reduce the fluff of the thread and reduce thread breakage. However, when the fibers are coated with a water-based oil, the filaments are adhesively bound together and appear to become one. (Although it is sparingly soluble in water, it is caused by swelling and a small amount of solubility.)
Therefore, it has the same effect as applying twist and glue, and it is possible to weave without twist or glue. If the sea component is removed after fabric production, the binding will come undone and the unique characteristics of ultra-fine yarn will appear. In addition, yarns whose sea component is polystyrene, which is commonly used in the past, are relatively coarse and hard, and buckling and bending during shrinkage can cause yarn breakage and sea cracks, exposing islands, which can be a problem during high-order processing. It's summery. However, fibers containing this copolyamide as a sea component are flexible and pose no problems in weaving and knitting, and are also highly effective in forming punched felts. As for the fiber oil, a water-based one is preferable when binding of filaments is required as described above. In addition, if the purpose is not for binding, use a non-aqueous mineral oil, silicone, fluorine, or aliphatic ester, which is blended with other materials necessary to meet the characteristics required of the thread. do it. However, since anionic surfactants have a large effect on the polymer, it is preferable not to use them in principle. Next, a method for removing copolyamide, which is a component in the composite fiber, will be described. Acids and alcohols are known as solvents for this copolyamide. When these solvents are dissolved in water to form a removal solution, a considerably high concentration is required for complete dissolution.
The required concentration is 10% or more for ethyl alcohol and 5% or more for sulfuric acid. Removal using such a highly concentrated solution is no different from conventional removal using trichlene or alkaline solutions and has no merit. It is most desirable to be able to dissolve it in water alone without using dangerous chemicals. Since this copolyamide has an affinity for water, various methods of dissolving it with water alone were tried, but even if the water temperature was changed from 20 to 120°C, complete dissolution could not be achieved with water alone. After extensive research, they discovered a method to easily dissolve the polymer by adding a small amount of surfactant to water. In other words, when anionic surfactant is added to water,
It is easily dissolved by adding 0.1% by weight or more. This anionic surfactant may be any conventionally known anionic surfactant, but those having a hydrophilic group of Na or K salt are particularly preferred. The characteristics of this removal solution using surfactant as an auxiliary agent are that compared to conventional solutions such as trichloride, formic acid, toluene, and alkali, (1) it is a normal soap, has low toxicity, and is a significant advance in terms of safety; (2) Fast dissolution rate. (3) Improved work efficiency. (4) No large investment is required for removal equipment. (5) In addition to its low toxicity, there is no discharge outside the system, including the recovery method described below, so there is no problem with environmental pollution. Although it may be removed from the composite fiber in the filament or staple state, it is more efficient to remove it after forming the fabric. The removal method is as follows: (1) A cloth is passed through a solution containing a surfactant kept at 50 to 80°C and squeezed with a mangle. (2) It is also possible to form a web and use WJP (Water Jet Punch) to inject the removal liquid and entangle the fibers to form a fabric (shortening the process).
Removal may also be performed through (3) After making the fabric, it may be placed in a dyeing machine and removed as a pre-dying process. Next, a method for recovering the polymer from the liquid containing the removed copolyamide and treating the residual liquid will be described. In addition to the low toxicity of the dissolving agent, disposal of the dissolved liquid is an essential issue from the standpoint of preventing environmental pollution and eliminating pollution. The inventors of the present invention have made extensive studies on this point and have found the following method. That is, relatively low temperature (60~
After dissolving and removing the solution at 70°C, heat the solution at 90°C.
~95°C), the dissolved polymer precipitates due to the solubility difference. This polymer may be collected by a method such as filtration, and the remaining liquid may be used again as a removal liquid. If this is repeated, there is no need to dispose of the liquid outside the system. Next, Examples according to the present invention will be shown, but the effectiveness of the present invention is not limited or interpreted as limited by the Examples, but the following application development is brought about. (Example) Prototype Example A sample was obtained by adding acrylonitrile to both ends of polyethylene glycol having a number average molecular weight of 600 and reducing it with hydrogen. 55% by weight of equimolar salt of α,ω-diaminopolyoxyethylene and adipic acid, ε-
A chip having a relative viscosity of 3.25 was obtained by melt polymerizing 25% by weight of caprolactam and 20% by weight of an equimolar salt of hexamethylene diamine and adipic acid. (Dissolve 1 g of polymer in 100 ml of chloral hydrate solution,
(measured at °C) This chip is the sea component, and the island component has an inherent viscosity.
The following two types of yarn were spun using 0.80 polyethylene terephthalate and two spindles for producing polymer array fibers. Composite fiber A. 16 islands x 18 filaments Composite fiber B. 145 islands x 6 filaments 285 with a ratio of 15% sea component and 85% island component by weight
It was extruded from a die at 120°C, cooled in air, and taken off at a speed of 1200 m/min while oiling. The resulting undrawn yarn, which had good drawability, was drawn using a draw twister. The stretching conditions and fiber properties were as shown in the table below.

[Table] Example 1 Composite fiber A obtained in the prototype example was doubled to form a 100,000 denier tow, which was crimped using a turbo feeder and then cut into 51 mm pieces to form staples. This staple was opened and passed through a card to create a laminated web using a cross wrapper. Next, 1600 needle punches/ ^cm2 were used to create felt. The weight of the felt was 580 g/m ² . This felt was impregnated with a polyurethane solution so that the amount of resin was 62 parts per 100 parts of the island component.
The sheet was introduced into water at 25℃ and coagulated for 10 minutes, then introduced into a 75℃ solution containing 98% water and 2% surfactant (sodium lauryl sulfate salt) and squeezed by mangle while continuously running in the bath. This process was repeated four times to extract DMF, which is the solvent for the polyurethane solution, and to remove the sea components at the same time. After drying, the green fabric was sliced into two slices from the center so that they had the same thickness. This gray fabric was raised on both sides using a buffing device, and then dyed using a circular dyeing machine to obtain suede-like artificial leather whose surface was covered with ultrafine fibers. It had an elegant appearance and touch characteristic of ultra-fine threads.
Furthermore, since the resin was attached and the sea component was removed before the sea component was removed, the ultrafine fibers of the resulting artificial leather were not directly bonded to the resin, so it was very flexible. Example 2 Composite fiber B obtained in the prototype example was used as a weft yarn to produce a high-density woven fabric with a plain weave structure. Polyethylene terephthalate 75 denier was used for the warp yarn. The weavability was good. This fabric was mixed with 98.5% water and surfactant (sodium dodecylbenzenesulfonate).
The sea component was removed by immersing it in a 1.5% by weight solution (70°C for 1 minute) and squeezing it with a mangle. This dipping and squeezing process was repeated three times. It was confirmed that the sea component was completely removed from the weight before removal and the weight after removal. (The fabric before removing the sea component does not have the roughness and hardness of conventional polystyrene, and is no different from ordinary fabrics. However, by removing the sea component, the ultra-fine fibers of 0.063 denier give it a silk-like luster and are extremely pleasant to the touch.) ) Next, one side was calendered to make it water repellent. The resulting high-density fabric had excellent heat retention and breathability, and had excellent drapability. Comparative Example 1 Acrylonitrile was added to both hydroxyl groups of ethylene glycol, and this was reduced with hydrogen. 78% by weight of equimolar salt of 1,2-bis(γ-aminopropoxy)ethane and adipic acid and 22% by weight of terephthalate. %
A copolymerized polyamide was obtained. The intrinsic viscosity in metacresol solution was 1.01. This chip was used as a sea component and spinning was carried out under the same conditions as in Example 1 using a spindle of 145 islands x 6 filaments. Collection speed
At 1,200 m/min, the threading properties were poor and it was not possible to take the thread. I had no choice but to change the speed to 600m/min. Threadability was good, but thread breakage occurred frequently. Also, since the melt viscosity of the sea component was low and the merging of the islands occurred, the sea component was changed to 40% by weight and the island component to be 60% by weight. The obtained undrawn yarn was stretched 3.38 times to obtain a drawn yarn of 110D x 6 filaments. The strength of this drawn yarn is 2.6g/d
It was low. This drawn yarn was used as a weft yarn in the same manner as in Example 2 to produce a high-density plain weave fabric. In order to remove sea components from this fabric, it was immersed in hot water at 100℃ (bath ratio 1/100) for 60 minutes, then dried, and the amount of sea components removed was determined from the weight before and after, and it was 72%. . The fabric after removal did not have the characteristic of using ultra-fine threads and had a stiff texture. When observing the cross section of the fabric, it was found that the composite fiber was 145
The islands in the outer periphery of the island were dispersed, but the inner periphery still had sea components and had not become extremely fine, but remained as thick fibers. (Effects of the Invention) 1. Ultrafine threads can be obtained without using harmful or toxic chemicals such as tricrene, perchlorene, toluene, formic acid, or alkali as sea component removers. 2. Removed sea components can be easily recovered. 3. The liquid used for removal can be reused.

Claims (1)

[Claims] 1 A composite fiber consisting of at least two components,
(A) polyoxyethylene in which one component has an amino group or carboxyl group at the end of an easily soluble polyether segment portion with a molecular weight of 200 to 2000
30 to 80% by weight of structural units consisting of component (B) and aliphatic dicarboxylic acid or aliphatic diamine
Using a composite fiber containing a copolymerized polyamide in which other components are hardly soluble, it is subjected to hot water treatment with the addition of 0.1% by weight or more of an anionic surfactant. A method for producing fibers, characterized by removing easily soluble components.